CN108705928B

CN108705928B - Hybrid commercial vehicle thermal management using dynamic heat generators

Info

Publication number: CN108705928B
Application number: CN201810321127.1A
Authority: CN
Inventors: 大卫·科拉纹森佐
Original assignee: Bendix Commercial Vehicle Systems LLC
Current assignee: Bendix Commercial Vehicle Systems LLC
Priority date: 2017-04-11
Filing date: 2018-04-11
Publication date: 2022-03-25
Anticipated expiration: 2038-04-11
Also published as: MX2018004403A; CN108705928A; DE102018108623A1; WO2018191410A1; CA3000362A1

Abstract

A system and method for hybrid electric-electric internal combustion engine applications is provided in which a motor-generator, a narrow switchable coupling, and a torque transfer unit therebetween are arranged and positioned in a constrained environment at the front of the engine in applications such as commercial vehicles, off-highway vehicles, and stationary engine installations. Preferably, the motor generator is positioned laterally offset from a switchable coupling arranged coaxially with the front end of the engine crankshaft. The switchable coupling is an integrated unit of a crankshaft vibration damper, an engine accessory drive pulley, and a disengageable clutch overlap, such that the axial depth of the clutch-pulley-damper unit is approximately the same as a conventional belt drive pulley and engine damper. The front end motor-generator system includes an electric energy storage portion that receives electric energy generated by the motor-generator when the coupling portion is engaged. When the coupling is disengaged, the motor-generator may use the energy returned from the energy storage to drive the pulley portion of the clutch-pulley-damper to drive the engine accessories, independent of the engine crankshaft.

Description

Hybrid commercial vehicle thermal management using dynamic heat generators

This application is a continuation-in-part application of U.S. application serial No.15/378,139 filed on 2016, 12, 14, the entire disclosure of which is expressly incorporated herein by reference.

Technical Field

The present invention relates to a hybrid electric vehicle, and in particular, to a system for selectively coupling a hybrid power generation and storage system with an internal combustion engine. The invention further relates to a method of operating the system.

Background

Hybrid electric vehicles having an internal combustion engine combined with a motor generator and an electrical energy storage system have become a focus of considerable attention in the automotive field, particularly in the passenger car field. The development of hybrid electric vehicle systems has only recently begun to raise significant interest in commercial and off-highway vehicles, such as trucks and buses in vehicle classes 2-8, earth moving equipment and railroad applications, and stationary internal combustion engine power plants.

Hybrid electric technology offers a number of advantages, including improvements in fuel efficiency, reductions in internal combustion engine emissions and vehicle noise that help meet government regulatory requirements, improved vehicle performance, and lower fleet operation costs. These advantages are obtained in large part by the ability of the hybrid electric powertrain to recapture otherwise wasted energy (such as mechanical energy caused by braking that would otherwise be dissipated as thermal energy to the outside) and return the captured energy at another time when needed, such as instead of using an internal combustion engine as a power source to power vehicle components or to assist in vehicle propulsion.

Typically, hybrid electric vehicle motor generators are arranged independently of the internal combustion engine (e.g., using a separate electric motor to power and recover energy from the front wheels while the engine provides propulsion power to the rear wheels), or are coupled to the engine, e.g., integrated into the "rear" of the engine (i.e., the end where the engine's flywheel is located) or between the engine and the drive train (driveline) to the wheels. This "behind the engine" position allows the motor-generator device to deliver torque directly to the driveline and wheels of the vehicle, and to be driven directly through the driveline, for example during a regenerative braking event. Examples of the latter include flywheel motor-generators, in which the flywheel of a conventional engine is modified to act as a motor-generator rotor and a concentrically mounted stator is located around the flywheel, and a separate electric motor disposed between the engine and the drive wheels, such as the so-called "two-mode hybrid" transmission given by the general automotive company in 2009GMC Silverado pickup, in which the transmission houses two electric motors for vehicle propulsion and electric energy generation.

Another form of adding a motor generator to an internal combustion engine is to use a so-called starter generator. The method directly couples the electric motor to the engine to function as both a generator (a function traditionally performed by conventional belt driven alternators) and an engine starter, thereby reducing the weight and cost of duplicate alternator and starter electric motors. Such a starter generator device is particularly useful in a so-called engine stop-start system that shuts down the engine during a period when the vehicle is stopped to save fuel and reduce idle emissions (idling). The starter generator is positioned behind the engine (e.g., a suitably engineered flywheel motor-generator may also be used as a starter) and is mounted at the front end of the engine, where the starter generator may drive a belt that is directly coupled to the engine crankshaft. An example of the latter system, the "with alternator starter" system, is offered by general automobile corporation as an option in 2007Saturn Vue sport utility vehicles. These systems are very difficult to adapt to large engines, such as commercial vehicle diesel engines, because the electric motor must be larger to handle the much higher torque requirements of these heavy duty engines, such as various components to start and operate (e.g., the engine cooling fan may require more than 50KW of power, requiring a large amount of torque to drive the load of the fan belt). Further, the belt drive in such an enlarged system may need to have the capability to transmit high levels of torque, which is not possible or at least not practical because thicker and wider drive belts and pulleys that adequately cope with torque requirements may be larger and heavier than their automotive counterparts, such that their weight, size, and/or cost are limited.

Another method of electrification is to use multiple separate electric motors to individually drive the energy consuming engine and vehicle accessories such as air conditioning compressors, power steering pumps, gas compressors, engine cooling fans, and coolant pumps to reduce fuel consumption by removing accessory loads from the engine. This approach significantly increases vehicle weight, cost, and wiring harness and control system wiring length and complexity, potentially offsetting the fuel economy or emissions reduction gains provided by removing the engine accessory load from the engine.

The prior art hybrid electric vehicle systems have a number of disadvantages that have prevented their adoption in applications such as commercial vehicles. These disadvantages include: engineering challenges associated with attempting to scale up hybrid electric powertrain components to handle the very high torque output of large engines (typically high torque output diesel engines); interdependence of engine and motor-generator operation due to these components being integrated into the rear of the engine or directly in the drive train (i.e., the engine and motor-generator must rotate together even when rotation of one or the other is not required or even detrimental to overall vehicle operating efficiency); and "hotel" loads (e.g., nighttime climate control and 120 volt power demand of a commercial vehicle tractor sleeping compartment) cannot be met independently without operating the vehicle's engine or operating a separate on-board auxiliary power unit ("APU"), such as a dedicated self-contained internal combustion engine package or a dedicated battery containing multiple conventional batteries and associated support equipment. These auxiliary power units are very expensive (typically several thousand dollars), very heavy, and require a lot of space on vehicles where space is already constrained. They also have the following further disadvantages: in the case of fuel-fired APUs, the potential hazards associated with open flames and the production of carbon monoxide that can enter the sleeping compartment during periods of driver rest; and in the case of an all-electric APU, there may not be enough energy returned to provide all of the accessory requirements of the vehicle for an extended period of time with the vehicle engine off.

Disclosure of Invention

Overview of the main front end motor generator system components.

The present invention addresses these and other issues by providing a hybrid electric vehicle system that is positioned at the front end of the engine, with the motor-generators arranged in a manner that requires little or no extension of the vehicle front length. As used in this description, the "front end" of the engine is the end opposite the end from which the torque output produced by the engine is transmitted to the main torque consumers, such as the transmission and driven axle of the vehicle or stationary engine mounted loads such as the pump drive. Typically, the rear end of the engine is where the engine flywheel is located and the front end is where components such as engine driven accessories (e.g., air conditioning and compressed gas compressors, engine cooling fans, coolant pumps, power steering pumps) are located. While the following discussion focuses primarily on commercial vehicle embodiments in which the engine crankshaft is aligned with the longitudinal axis of the vehicle, the invention is not limited to front engine, longitudinally aligned engine applications, but may be used with transversely mounted engines (including transversely mounted engines positioned at the front or rear of a vehicle) that may also have a space height constrained environment in the region adjacent the end of the engine opposite the flywheel end.

Preferably, the front end motor-generator system of the present invention has a motor-generator positioned in a front region of the engine, which is laterally offset from the rotational axis side of the engine crankshaft. Preferably, the motor generator is supported on a torque transmitting section (also referred to as a "drive unit"), e.g. a single reduction parallel shaft gearbox of narrow depth arranged with its input rotation axis coaxial with the engine crankshaft. Preferably, the motor generator is positioned behind the torque transmitting section in a space between the engine and an adjacent longitudinal vehicle chassis frame member, or in front of the torque transmitting section in a space below a coolant radiator of the vehicle. The invention is not limited to these locations for the motor generator, but it may be located anywhere in the area near the front of the engine, as long as the torque transmitting section to which it is mounted can be aligned with the engine crankshaft axis of rotation.

Preferably, the torque transfer section also provides a suitable speed ratio (e.g., 2: 1 ratio) between its input and output to better adapt the engine and motor-generator speeds to each other, i.e., to provide an increase in speed from the engine to the motor-generator and a decrease in speed from the motor-generator output. The torque transfer section may be a geared gearbox or another drive arrangement, such as a chain belt, on the motor generator side of the disengageable coupling (discussed further below) between the engine crankshaft and the torque transfer section, which transfers torque between the motor generator side and the engine of the torque transfer section. The torque transmitting section has an axially narrow profile to allow it to be received between the front of the engine crankshaft and any component in the front of the engine, such as the coolant radiator of the engine.

An important feature of the present invention is that the motor generator exchanges torque with the engine crankshaft via a switchable coupling (i.e. disengageable) between the torque transfer section and the crankshaft front end. The switchable coupling comprises an engine-side part directly coupled to the engine crankshaft, a drive part engageable with the engine-side part for transferring torque therebetween, and an engagement means, preferably a clutch actuated in the axial direction between the drive part and the engine-side part. The engine-side portion of the coupling includes a crankshaft vibration damper (hereinafter, "damper") unlike a conventional crankshaft damper, which is conventionally a separate component fixed to the crankshaft as a dedicated crankshaft vibration suppression device. This arrangement enables torque to be transferred between the accessory drive, the motor generator and the engine in a flexible manner, for example, an accessory drive that causes the accessory drive to be driven by a different torque source (e.g., the engine and/or the motor generator), an engine as a torque source to drive a motor generator as a generator, and/or a motor generator coupled to the engine and operated as a motor to act to supplement a vehicle propulsion torque source.

Particularly preferably, the switchable coupling is an integrated clutch-pulley-damper unit with a clutch between the engine-side damper part and the drive part. The drive side portion includes a drive flange configured to be coupled to the engine end of the torque transmitting section, the drive flange also including one or more drive pulley members on an outer periphery thereof. The preferred construction also has three components, a pulley, a clutch and a damper, arranged concentrically, at least two of which overlap one another along their axes of rotation. This arrangement results in a disengageable coupling with a greatly reduced axial depth to facilitate installation of the FEMG in a space-constrained environment in front of the engine. The axial depth of the coupling may be further minimized by reducing the axial depth of the clutch, pulley and damper to a point where the drive pulley extends concentrically around all, or at least substantially all, of the clutch and engine side damper portions of the coupling.

Alternatively, more than one of the three parts, clutch, pulley and damper parts, may be arranged coaxially with the others but without axial overlap as required to suit a particular front end arrangement of the engine from a different engine feeder. For example, in engine applications where the belt drive is not aligned with the damper (i.e., the damper does not have a belt drive slot around its outer periphery, such as in some

In an engine arrangement), the belt drive surfaces of the pulley portions of the coupling need not axially overlap the damper. Other applications having a belt driving surface on the outer circumference of the damper and further on a pulley mounted in front of the damper, such as in some Detroit

In an engine, the coupling that would be used to replace the original damper and pulley may be arranged with two belt driving surfaces on the pulley extending axially beyond the damper (i.e., the damper generally overlaps both the damper and the clutch axially), or stated otherwise, a belt driving surface on the outer periphery of the damper may be maintained (e.g., to drive an engine accessory that is never disconnected from the crankshaft, such as an engine coolant pump), while the other belt driving surface is positioned on a pulley member extending axially beyond the clutch.

Although in the following description the damper part of the switchable coupling is referred to as being connected to the engine crankshaft, the switchable coupling engine connection is not limited to being connected to the crankshaft, but may be connected to any rotatable shaft of the engine accessible from the front of the engine, such as a crankshaft driven jack shaft or a suitably engineered camshaft having a front accessible shaft end, the engine being capable of transmitting torque between the engine and the motor generator. Further, although in the following description, a part of the switchable coupling having the damper is connected to the engine crankshaft with reference, the engine-side connection of the switchable coupling is not limited to the part having the damper but includes a part having no damper (such as a plate member) that can be connected to the rotatable engine shaft while supporting an engine-side part of the disengageable coupling (such as an engine-side clutch plate that holds the switchable coupling opposite to the pulley-side clutch plate).

Preferably, the FEMG motor-generator is electrically coupled to an electrical energy storage unit (also referred to herein as an "energy storage portion"). Preferably, the energy storage includes both a battery suitable for high capacity, long term energy storage, such as a lithium chemistry-based battery capable of storing and returning large amounts of energy at moderate charge/discharge rates, and a supercapacitor capable of receiving and releasing electrical energy at very high charge/discharge rates that may exceed the capability of lithium batteries to safely handle. This combination provides an energy storage portion that can work with the motor-generator to absorb and/or drain current at higher than normal levels for short periods of time (i.e., over a wider range than the range of motor-generator input or output loads that the battery unit can handle), while also providing battery-based long-term energy storage and return at lower charge and discharge rates.

While the present disclosure is primarily directed to the use of the FEMG system in vehicular applications (particularly commercial vehicular applications), the FEMG system is also well suited for stationary engine installations (e.g., spare diesel generators), off-highway engine applications such as self-propelled construction equipment, and other engine applications where the effective space in front of the engine to provide hybrid electric performance is limited.

Overview of FEMG Driving of Engine Accessories

Traditionally, engine accessories are belt driven, directly driven by the engine crankshaft via a drive belt pulley bolted to the crankshaft. In the FEMG system, the engine accessories are also driven by a pulley, but the pulley is positioned on the motor-generator side of the clutch-pulley-damper (the "drive portion" identified above). The pulley of the clutch-pulley-damper unit is driven by the engine when the coupling is engaged, or by the motor generator when the coupling is disengaged. When the pulley clutch damper is disengaged, all engine accessories driven by the pulley are disconnected from the engine, removing their respective power requirements from the engine. Isolation of the accessories from the engine reduces fuel consumption when the engine is running. Further, because the accessories can be independently driven by the FEMG motor-generator via the torque transmitting section while the coupling is disengaged, the engine can be shut down or idle operated with little or no parasitic load while the vehicle is in a stopped state, thereby saving fuel and reducing emissions.

Further system efficiency gains may be achieved when the clutch-pulley-damper is disengaged, since the operating speed of the motor-generator may be varied as desired to operate more than one engine accessory at a speed that provides increased operating efficiency while other engine accessories are operating at a speed that is not optimally efficient, if so, reducing overall energy consumption.

Preferably, to increase system efficiency, some or all of the engine accessories may be provided with a separate drive clutch (on/off or variable slip engagement) to enable selective operation of the engine accessories while other engine accessories are shut down or operated at a reduced speed. The combination of the ability to operate the motor-generator at variable speeds and selectively engaging, partially engaging, and disengaging individual accessory clutches provides for tailoring accessory energy consumption to only that needed for current operating conditions, further increasing overall system efficiency.

Alternatively, when one engine accessory has a high power input demand that must be met under current vehicle operating conditions, the motor-generator may be driven at a speed that ensures that the engine accessory with the highest demand can perform as needed, while the other accessories are operating at less than optimal efficiency, or disconnected from the motor-generator driven by its respective clutch (if so equipped).

Preferably, as discussed further below, the FEMG controller performs an evaluation of factors such as engine accessory operating efficiency data and current vehicle operating state information (e.g., energy storage portion state of charge ("SOC"), engine torque output demand, coolant temperature) to select a combination of vehicle operating parameters (e.g., engine accessory clutch alone, accessory operating speed, clutch-pulley-damper pulley speed and engagement state, motor-generator speed and torque output) to determine a compromise configuration of coupling and clutch engagement state and component operating speed that meets vehicle operating requirements while reducing fuel and energy usage. For example, while providing superior overall system efficiency may be achieved by operating the motor-generator at a speed and torque output that places as many of the engine accessories at or near their peak operating efficiency state, certain vehicle requirements (such as the need to operate a high torque demand engine cooling fan to control engine coolant temperature) may cause the FEMG to control motor-generator speed and/or torque output to ensure that the particular requirements are met, and then to operate other individual engine accessories driven by the clutch-pulley-damper in as efficient a manner as possible under the present vehicle operating conditions.

Similarly, if the current demand for vehicle propulsion torque from the engine is high (and the state of charge of the energy storage allows), the FEMG controller may control the clutch-pulley-damper to switch to the engaged state and command the motor-generator to supply supplemental torque to the engine crankshaft to increase the overall output of propulsion torque, even though the engine accessories are driven at less than optimum efficiency because their speed is related to crankshaft speed.

Overview of the use of the Motor-Generator

When operating conditions permit, the clutch-pulley-damper may be engaged such that mechanical energy may be recovered from the engine crankshaft by the motor-generator (i.e., mechanical energy transmitted from the wheels to the motor-generator through the driveline is recovered to the engine crankshaft). For example, during a deceleration event, the clutch may be engaged to allow the motor-generator to function as a generator in a regenerative braking mode, a mode that also results in cost savings and savings in fuel consumption by minimizing brake air usage and associated compressed air consumption resulting in reduced brake pad or brake pad wear, which in turn reduces gas compressor usage and energy consumption. The clutch may also be engaged when there is any other "negative torque" demand, such as when it is desired to provide a retarding force to minimize undesirable vehicle acceleration due to gravity when the vehicle is traveling down a hill.

When the disengageable pulley clutch damper is engaged and operating conditions warrant, the motor-generator may be operated as a production torque motor to supply supplemental torque to the engine crankshaft, thereby increasing the total torque output supplied to the vehicle driveline to improve vehicle acceleration.

Other uses of the motor-generator are as a primary engine starter, eliminating the need for a heavy, dedicated starter motor. In this mode of operation, the clutch-pulley-damper is engaged to allow the motor-generator torque to be transmitted directly to the engine crankshaft. This use of the motor generator is well suited to the operating characteristics of the motor generator as it is capable of producing a very high torque output when starting at 0rpm and doing so nearly instantaneously. The very fast reaction time of the motor-generator and the ability to do so many times without overheating makes the FEMG system an excellent choice for use as the primary engine starter motor in a fuel efficient engine "stop/start" system where the engine is started and stopped many times a day. Short restart reaction time capability is highly desirable in stop/start system applications where it is well known that in response to a driver's demand for resumption of movement (typically a demand generated by releasing the vehicle's brake pedal after the traffic signal turns green), the driver is dissatisfied with any significant delay in automatic engine restart. For example, the driver typically finds a delay of one second or more before the engine starts and the vehicle starts moving to a minimally, if not completely unacceptable, annoying state.

Alternatively, the motor-generator of the FEMG system may operate as an engine starter in conjunction with a pneumatic starter motor that converts stored compressed gas pressure into a mechanical torque output (typically, a pneumatic starter is lighter and less costly than a conventional electric starter motor). The combined FEMG/pneumatic start arrangement may be utilized to improve FEMG system weight and cost, as the supplemental torque output of the pneumatic starter may allow for a reduction in FEMG motor generator size where the highest anticipated torque demand on the FEMG motor generator is associated with an engine start (particularly, a cold engine start). In this case, the FEMG motor-generator may be sized to meet the next lower demand torque demand (e.g., the highest torque demand expected in the combination of the most demand on the engine accessories), while the pneumatic starter may be used to provide the additional engine cranking torque needed above that provided by the smaller FEMG motor-generator.

The motor-generator may also be driven via the engine through an engaged clutch-pulley-damper clutch in a manner that eliminates the need to equip the engine with a heavy, dedicated alternator to supply operating voltage to the 12 volt dc current circuit of a typical vehicle, such as the vehicle lighting circuit, the power supply to the electronics module, and the 12V powered driver comfort features (heated seat, sleeping compartment electrical, etc.). In an FEMG system, the required 12V power supply can be easily provided by a voltage converter that reduces the operating voltage of the energy storage (approximately 300-400 volts) to the 12 volts required by the vehicle circuitry. Thus, the electric energy generation of the motor-generator charging the energy storage provides a source of 12V electric energy, which allows the elimination of a conventional engine-driven alternator. The storage of large amounts of energy in the energy storage portion also creates the potential for removing additional weight and cost from the vehicle by reducing the number of 12V batteries that need to be carried to meet various needs of the vehicle. For example, a vehicle, which may typically have four separate 12V batteries, may only require a single 12V battery with an energy storage portion.

Similarly, the voltage converter may be used to directly supply 120 volt ac power directly to the vehicle, for example to a sleeping compartment for appliance or air conditioning use, or to an attached trailer to operate a trailer device such as a refrigeration unit (the latter, preferably, a CAN system with the trailer connected to the vehicle for tractor-centric monitoring and control of trailer accessories). The FEMG system may also eliminate the need to equip the vehicle with an expensive and heavy internal combustion engine powered auxiliary power unit to support vehicle operation when the engine is shut off for long periods of time if the energy storage is designed to provide sufficient storage capacity. For example, the APU may no longer be needed to power the sleeping car air conditioning unit during overnight driver rest periods.

The FEMG can also potentially be used as an active damper to count the rapid torque reversal pulses ("torque ripple") sometimes encountered during various load, speed, and environmental conditions. In this application, the FEMG control module would receive a signal from a vehicle sensor indicating that there is a torque ripple and output a command to the motor-generator to produce a count torque pulse that is timed to cancel the driveline torque reversal pulse. This active damping based on the FEMG motor-generator may help protect the driveline from mechanical damage caused by high stresses induced by rapid changes in torque load, and improve driver comfort by removing rapid acceleration/deceleration transmitted to the driver's cabin via the vehicle chassis.

The switchable coupling of the present invention may also be used with a dynamic heat generator ("DHG"), preferably in a FEMG system with a motor generator, to perform a number of additional functions and provide additional benefits, including potential emissions slowdown and operational cost savings.

Dynamic heat generators are hydrodynamic devices, typically shaft driven, in which a fluid is subjected to shear forces in order to generate heat in the fluid. The heated fluid may then be distributed to other applications in the vehicle, for example, to warm up the internal combustion engine, to improve cold starts and reduce the time required to reach engine operating temperatures at which emission control devices are effectively active, or to warm up the sleeping compartment of a commercial vehicle. An example of such a DHG is the No. air450 model available from Island City LLC of meilin, wisconsin. DHGs suitable for use in commercial vehicle applications may have a pulley at one end that is drivable by an engine accessory belt drive. The DHG may also have a coaxial circulation pump unit positioned at its opposite end to provide sufficient inlet fluid pressure and volume to feed fluid to the DHG inlet and push the passing fluid through the DHG to the downstream consumers. Preferably, such an integrated DHG and pump would include a bypass circuit (discussed further below) that enables the pump output to bypass the DHG when it is not desired to add heat to the fluid. The pulley may be connected to the DHG via a selectively engageable pulley clutch so that the DHG may be disconnected from the engine accessory drive when DHG operation is not desired. Alternatively, the pump may be driven separately from the DHG and/or separately from the DHG.

Preferably, there is a DHG in the FEMG system so that when the clutch-pulley-damper unit is disengaged from the engine crankshaft, the motor generator coupled to the torque transfer can drive the DHG via the accessory drive. This configuration allows the DHG to be used to generate heated fluid during engine operation and when the engine is shut down, such as when it is necessary to comply with anti-idle requirements.

In a preferred embodiment, the working fluid of the DHG is the same as the engine coolant. This configuration minimizes maintenance costs associated with the use of multiple fluids in different systems and minimizes the potential for mixing incompatible fluids (e.g., oil and coolant) across heat exchange boundaries by allowing DHG integration into the coolant circulation system without the need for an intermediate fluid to fluid heat exchanger.

In addition to the devices used to add heat to the working fluid, the DHG may be placed upstream of one or more devices that require cooling, particularly devices that operate at temperatures significantly higher than the temperature of the fluid exiting the DHG. For example, components such as hybrid vehicle battery packs, motor generators, and power electronics may all require cooling to prevent overheating of the electronic components, while the battery pack also needs to be heated during low ambient temperature operation. DHG in the coolant loop may be used to provide cooling to these components, particularly in an FEMG system when the clutch-pulley-damper is disengaged from the engine crankshaft and the FEMG motor-generator is operated to supply torque to the accessory drive, which may require the operation of cooling of the motor-generator, converting electrical energy taken from the battery pack to supply power electronics of the motor-generator at the appropriate voltage and current, and the battery pack itself.

One of the significant benefits of using a dynamic heat generator in a FEMG system is the potential elimination of the need to install an auxiliary power unit ("APU") with an internal combustion engine on a vehicle in order to ensure that the vehicle can be provided with auxiliary heating, cooling, and power supplies when the primary vehicle engine is off (e.g., to power and control the environment in the sleeping compartment and/or cabin of the vehicle during overnight rest stops). In addition to avoiding thousands of dollars of APU initial acquisition and installation costs, ongoing APU internal combustion engine maintenance costs, and fuel consumption costs associated with the weight of an APU carried on a vehicle at all times, the use of a dynamic heat generator eliminates the emission of exhaust gas from the APU's internal combustion engine, which would otherwise occur throughout the life of the vehicle. This is a particularly significant advantage as governments impose new and increasingly more stringent limits on "idle emissions," such as when the engine is running while standing overnight or at work for a long period of time during a rest period.

Another advantage of using a dynamic heat generator in a FEMG system is the operational flexibility inherent in the dynamic heat generator. For example, internal combustion engines (in the prime mover or APU of a vehicle) often do not operate in an efficient manner (e.g., consume fuel and cause emissions even at idle or operating under load at speeds above or below a peak efficiency range). Such engines may also not operate efficiently when operating conditions require that they operate at speeds above or below that which would otherwise meet the requirements of a particular vehicle component, such as a gas compressor or air conditioning compressor. In contrast, dynamic heat generators are very flexible in operation, are capable of operating over a wide range of speeds, and are capable of operating at partial energy output when vehicle demand for fluid heating is relatively low. Although operating at a lower level of efficiency, with this flexibility, the dynamic heat generator only needs to draw energy from the energy storage as required in a particular situation, and thus uses less energy overall. This minimizes the energy consumption of the energy storage, thus extending the length of time the engine may remain off before the energy storage must be recharged, and ultimately, minimizing the amount of fuel that must be consumed to recharge the energy storage when the engine is running. Thus, the savings in procurement and operating costs of the APU, as well as the fuel consumption and emissions savings associated with using a dynamic heat generator with a FEMG system, generally offset the weight and cost of the relatively small dynamic heat generator and its associated components (e.g., hoses, wires, belt drive pulleys, and clutches).

Overview of FEMG controller Programming and operating methods

In a preferred embodiment, the FEMG controller, preferably in the form of an electronic control module, monitors a plurality of vehicle signals, including signals available over the CAN and/or SAE J1939 bus networks of the vehicle, if the vehicle is so equipped. One of the signals may be a state of charge (SOC) indication from a battery monitoring system that monitors, among other parameters, the state of charge of the energy storage. The control module may be programmed to, for example, identify three levels of state of charge, a minimum level of charge (e.g., 20% state of charge), an intermediate level of charge (e.g., 40% state of charge), and a maximum level of charge (e.g., 80% state of charge). The control module may be further programmed to include: the state of charge, which is the factor in determining when to engage and disengage the clutch of the clutch-pulley-damper, at what speed the motor-generator should operate, the operating speed of some or all of the engine accessories driven from the pulley of the clutch-pulley-damper, and what combination of vehicle component operation and operating parameters will increase the overall vehicle operating efficiency while meeting the current operating needs of the vehicle and meeting the requirements for safe vehicle operation (e.g., maintaining a minimum required amount of gas pressure in at least the pneumatic system compressed gas storage tank of the vehicle by operating the gas compressor, even if doing so would reduce the overall energy efficiency of the vehicle).

In one embodiment, when the state of charge of the energy storage is below a minimum charge level, the clutch of the clutch-pulley-damper may be engaged and the motor-generator controlled by the control module to cause the motor-generator to produce electrical energy for storage. In this mode of operation, the motor generator is powered by the engine or by the wheels via the drive train via the engine. Once the state of charge is above the minimum charge level, the clutch of the clutch-pulley-damper may remain engaged until an intermediate charge level is reached, and the motor-generator is controlled to generate electrical energy only during braking, deceleration, or negative torque conditions. This mode allows mechanical energy not provided by the engine to be used by the motor-generator on an available basis, thereby continuing to charge the energy storage, while minimizing the amount of engine energy that must be provided to the motor-generator, thereby reducing fuel consumption.

In another mode of operation, once the intermediate charge level is reached, the control module may determine that the clutch-pulley-damper clutch may be disengaged and the motor-generator is used as a motor to generate torque to drive the engine accessories without assistance from the engine, i.e., the motor-generator becomes the sole source of driving energy for the engine accessories. In this mode, the motor generator draws stored electrical energy from the energy storage to generate torque for transmission through the drive unit gearbox to the pulley of the clutch-pulley-damper to drive engine accessories such as the engine cooling fan and the gas compressor of the pneumatic supply system. By disengaging the engine depending on the torque requirements of the engine accessories, the engine may be operated with a lower parasitic torque load to reduce fuel consumption of the engine or to make more of the engine torque output available to propel the vehicle. Alternatively, when the motor generator may be operated in a motor mode to drive the engine accessories, the engine may be shut down as a whole, such as when in stop and go traffic in a vehicle equipped with a start/stop system.

Between the intermediate charge level and the maximum charge level, the front end motor-generator control module continues to monitor the vehicle operating state, and during braking, deceleration or negative torque conditions may take advantage of further charging the energy storage portion without using engine fuel by engaging the clutch of the clutch-pulley-damper and controlling the motor-generator to generate electrical energy. While charging during braking, a deceleration or negative torque condition may occur whenever the energy storage is below the maximum charge level; in this embodiment, avoiding the use of engine fuel for charging above the intermediate charge level reduces fuel consumption and improves overall efficiency.

At any point above the minimum charge level, the motor-generator may operate as a motor to generate torque to be delivered to the engine crankshaft to supplement the torque output of the engine, thereby increasing the amount of torque available to propel the vehicle. The increased torque output to the driveline enables improved vehicle acceleration and provides additional benefits, such as improved fuel economy because of fewer transmission shifts and faster acceleration to cruising speeds (e.g., "skip-shifting" in which the motor-generator adds sufficient engine torque to allow for more than one gear ratio to be passed as the vehicle accelerates, thereby reducing vehicle time for speed regulation and fuel consumption). Additionally, in vehicles equipped with a pneumatic boost system ("PBS" injecting compressed gas into the engine intake to provide extra engine torque output very quickly), if possible, instead of using compressed gas injected from the PBS system to produce extra engine torque output, using substantially "instant-on" torque assisted from the motor-generator, compressed gas usage can be reduced, thereby further reducing fuel consumption and component wear (consumption and wear associated with additional gas compressor operation to supplement the compressed gas supply).

Once the FEMG control module determines that the maximum charge level is reached and therefore no further input of electrical energy into the energy storage is desired, the control module will prevent the motor-generator from operating as a generator in order to protect the energy storage from damage due to overcharging. In this mode, the motor-generator may be used solely as an electric motor to drive and/or provide supplemental drive torque to the engine accessories, or the motor-generator may be allowed to spin in an idle state with no power production if there is no current engine accessory demand.

Preferably, the FEMG controller communicates with several vehicle controllers, such as a brake controller of the vehicle (which may control different types of brakes, such as pneumatic or hydraulic brakes), an engine and/or transmission controller, and one or more controllers that manage the energy storage. These communications allow for cooperative operation of the vehicle systems. For example, in the event that the braking demand is sufficiently low to only require the use of an engine retarder, the brake controller and the FEMG control module may signal each other to prioritize the motor-generator over the use of the retarder such that if the energy state of charge would allow storage of additional electrical energy (i.e. the energy storage portion state of charge below the maximum state of charge allowed), the motor-generator provides regenerative braking. Conversely, if the operating conditions do not result in a desire to generate additional electrical energy via the motor-generator, the FEMG control module may signal the brake controller so that the brake controller activates the retarder to provide the desired amount of braking. Preferably, communication between controllers is in progress, providing the ability to quickly update status. For example, if the driver reduces the amount of braking demand during a braking event, the brake controller may be able to signal the FEMG control module to reduce the amount of regenerative braking.

Another example of possible inter-controller communication is gas compressor operation in cooperation with energy storage management. For example, the gas compressor controller may signal the FEMG control module to operate the motor-generator with the clutch-pulley-damper disengaged (engine running or shut down) to drive the gas compressor at a desired speed to supplement compressed gas storage due to large gas consumption requirements (such as tire inflation systems attempting to combat large tire pressure leaks, large leaks in the tractor or trailer gas lines, use of the air landing gear of the trailer, high air release during ABS system brake pressure regulation or trailer stability system activation on low friction road surfaces, operation of the kingpin pneumatic locking/unlocking device, or actuation of the pneumatic lift axle).

Additional operational improvements provided by FEMG systems

In addition to the features, performance and advantages already described, the front end motor-generator approach of the present invention has important advantages that do not require substantial modifications to the front of the vehicle, such as lengthening the nose of a commercial vehicle tractor or increasing the size of the engine compartment of a diesel powered municipal bus. This is a direct result of the fact that the FEMG system is easily housed between the front of the engine and the coolant radiator of the engine to transfer torque laterally to and from the motor generator by using an integrated clutch-pulley damper unit and an associated axially narrow drive unit. As a result, the FEMG system is particularly suitable for incorporation into existing vehicle designs during new vehicle assembly processes and retrofitting of existing internal combustion engines to retrofit older vehicles (particularly commercial vehicles) and stationary engine installations by utilizing hybrid-electric technology.

Another operational advantage provided by the FEMG system is its ability to have the motor generator assist the engine to provide short duration "over-speed" vehicle operation. In such an application, the controller of the vehicle will add supplemental torque from the motor-generator in conjunction with a temporary override of the vehicle's governor to allow a brief "burst" of speed, for example to allow a quick cut-in completion of a vehicle of similar speed, such as another large truck. While use of such operating modes should be limited to brief, infrequent periods to minimize engine and driveline component overload, the FEMG system may be programmed to provide a driver-actuated "overrun" mode, i.e., the driver may toggle an option (e.g., "press to override" a button) to briefly increase speed on demand. Preferably, such pressing in an override mode may cooperate with the vehicle's blind spot monitoring controller via the CAN network, for example, so that overspeed operation CAN be automatically terminated once the blind spot monitoring system indicates that the overridden vehicle is no longer alongside. The cooperation of terminating the supply of the supplemental torque of the motor generator to the engine crankshaft by the FEMG control module includes as part of terminating the mode.

Motor-generator supplemental torque has further applications, such as reducing driver fatigue in driver assistance systems by automatically adding torque, which when done will minimize the need for the driver to manually shift the transmission, particularly when climbing hills (and when associated safety requirements are met, such as nothing in the field of view of the vehicle's adaptive cruise-control camera and/or radar system).

The supplemental motor-generator torque may also be used in a trailer weight determination system, where a known amount of additional torque is added and a measure of vehicle acceleration caused during the application of the supplemental torque is used in the vehicle mass calculation.

In case of safety concern, the addition of supplemental drive torque from the motor-generator should be constrained. For example, when a low friction signal is received from the trailer indicating that the trailer wheels encounter a low friction surface, the command to supplement torque delivery should be inhibited.

The application of the FEMG system is not limited to the application in which the motor generator is the only generator. The mating may be achieved by adding an FEMG front end mount to the engine and/or to the drive train, which also includes a motor-generator unit to the rear of the crankshaft side of the FEMG clutch, e.g. at the rear of the engine (such as a flywheel motor-generator), in the downstream drive train (such as a motor-generator incorporated in the transmission), or at the front end of the crankshaft, i.e. at the always engaged side of the FEMG clutch-pulley-damper unit.

The combination of the FEMG system and the "rear end" hybrid electric arrangement gives the possibility of overall vehicle operation improvement. For example, having a front end system and a back end system may enable one or both of the motor-generators to be reduced in size and weight while also meeting vehicle requirements, as the motor-generators need not be sized to handle all of the vehicle electrical needs, wherein there is no longer a need to meet all of the vehicle power generation and supply requirements with only one motor-generator. Further, operational flexibility may be increased by having two motor generators, if each motor generator is able to at least meet basic vehicle requirements in the event of failure of the other motor generator, thereby allowing the vehicle to continue operating, perhaps with reduced performance, until such time or where repairs may be performed.

The operation of the FEMG system and the rear end motor-generator may also cooperate to split and/or share the load as needed to optimize vehicle operation. For example, where the FEMG system assumes that the engine accessory drive and energy storage charging requirements are simultaneously contributing to propel the vehicle by providing supplemental torque output to the vehicle driveline to assist the rear end motor-generator of the engine, the load may be split between the motor-generators. An example of a shared coordination would be to use the rear end motor-generator to receive and store energy from regenerative braking of the driveline while keeping the FEMG decoupled from the crankshaft to improve engine accessory efficiency (i.e., to allow capture of regenerative braking energy by the rear end motor-generator even when the FEMG system is decoupled from the crankshaft and thus unable to capture braking energy that would otherwise be wasted). The flexibility of combining the FEMG system with another portion of the hybrid powertrain system is unlimited, e.g., operating both motor generators in conjunction with an engaged FEMG clutch to cause both motor generators to provide supplemental drive torque or to capture regenerative braking energy for storage using both motor generators, etc.

The FEMG components and controller may also be adapted for use in applications that benefit from the ability to decouple the engine accessories from the engine crankshaft, but without the need for power generation capacity that would be provided by a full FEMG system installation. Such "motor-only" applications may include vehicles having operating needs that do not require additional expense and complexity of high voltage electrical energy storage and distribution systems, but may also benefit from the ability to decouple the engine crankshaft from the accessory drive using the FEMG system and drive the accessories using the FEMG motor to improve efficiency. Such motor-only operation may be supplied from a smaller, simpler battery pack whose state of charge may be maintained by the alternator of the vehicle engine.

For example, an engine in a container transport vehicle used at a container ship port loading/unloading yard does not require the ability to be powered for long periods of time when the engine is off, such as to provide nighttime power to a sleeping car of an off-road truck. And container truck efficiency and/or torque output can be improved by utilizing the crankshaft disconnect coupling of the FEMG system and its associated control of the accessory drive by the FEMG motor. For example, by decoupling the crankshaft from the accessory drive to remove accessory loads from the engine under various operating conditions, such as at idle times, efficiency improvements may be realized; to allow operation of the transport system for short periods of time while the engine is off to enable fuel-efficient engine stop-start operation; and devoting all of the engine torque output to the transport drive by removing the auxiliary drive torque demand from the engine as needed. Similarly, when it is desired to have the FEMG motor supplement the propulsion torque output of the engine, only the motor FEMG system may be coupled to the engine crankshaft. This latter feature may enable further improvement by allowing the engine to be smaller, lighter, and less costly by being sized to meet the "average" torque demand, while the FEMG motor provides supplemental torque as needed to meet the design total propulsion torque demand of the vehicle.

In summary, the front end motor-generator system of the present invention is uniquely suited to provide for new and retrofitted commercial, off-highway and stationary engine installations using a hybrid electric system having a mechanically simplified, space-efficient and cost-effective universal electric drive that allows for variable speed control of engine accessories: the ability to drive engine accessories independent of engine crankshaft speed, and to store and return energy when the engine is not running to operate an electrically powered system for long periods of time, thereby providing significant overall fuel and cost efficiency improvements by:

minimizing engine accessory energy consumption, thereby increasing fuel economy (i.e., removing accessory torque demand on the internal combustion engine when the clutch-pulley-damper unit is disengaged from the engine crankshaft),

recovering energy that would otherwise be wasted (e.g., generating electrical energy for storage rather than applying wheel brakes to convert vehicle kinetic energy into waste heat), and

extended component life (e.g., operating accessories such as engine cooling fans, air conditioning compressors, and gas compressors only as needed and at accessory speeds and/or duty cycles corresponding to actual vehicle demands, rather than all accessories being forced to operate at speeds dictated by engine crankshaft speed; minimizing brake wear and compressed gas usage that would otherwise require the engine to drive the gas compressor operation).

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

Drawings

Fig. 1A and 1B are schematic diagrams of overall views of the arrangement of an FEMG system according to an embodiment of the present invention.

Fig. 2A-2C are cross-sectional views of an embodiment of a clutch-pulley-damper and assembled FEMG components according to the present invention.

Fig. 3A-3C are views of components of the clutch-pulley-damper unit of fig. 2A-2C.

Fig. 4 is a cross-sectional view of another embodiment of a clutch-pulley-damper unit according to the present invention.

Fig. 5 is a detailed cross-sectional view of a bearing arrangement at the clutch-pulley-damper unit end of a FEMG gearbox according to an embodiment of the present invention.

Fig. 6A-6C are oblique views of a FEMG drive unit in the form of a gearbox according to an embodiment of the invention.

Fig. 7 is a cross-sectional view of the FEMG gearbox of fig. 6A-6C.

Fig. 8 is an exploded view of an FEMG clutch pneumatic actuator diaphragm arrangement according to an embodiment of the present invention.

Fig. 9 is an oblique view of another embodiment of a FEMG gearbox according to the present invention.

Fig. 10 is a schematic diagram of a FEMG gearbox mounting arrangement according to an embodiment of the invention.

Fig. 11 is a schematic diagram of a FEMG gearbox mounting arrangement according to an embodiment of the invention.

Fig. 12 is a schematic diagram of the relationship between an engine and a FEMG gearbox mounting bracket according to an embodiment of the invention.

Fig. 13 is a schematic diagram of the relationship between an engine, a FEMG gearbox and a FEMG gearbox mounting bracket according to an embodiment of the invention.

Fig. 14 is an oblique view of the FEMG gearbox mounting bracket of fig. 12-13.

Fig. 15 is an oblique view of a motor generator according to an embodiment of the present invention.

FIG. 16 is a graph of power and torque produced by an example motor-generator according to an embodiment of the invention.

Fig. 17 is an oblique perspective view of a cooling arrangement of a motor generator according to an embodiment of the present invention.

Fig. 18 is a block diagram of a FEMG system control and signal exchange arrangement according to an embodiment of the present invention.

Fig. 19 is a schematic diagram of AC and DC portions of a grid of a FEMG system according to an embodiment of the invention.

Fig. 20 is a schematic diagram of a FEMG system-controlled power transistor arrangement for AC and DC conversion according to an embodiment of the present invention.

Fig. 21 is a schematic diagram of a FEMG system-controlled forward DC voltage converter arrangement according to an embodiment of the present invention.

Fig. 22 is a schematic diagram of a high voltage bi-directional DC/DC converter according to an embodiment of the present invention.

Fig. 23 is a graphical illustration of the voltage and current response across the bi-directional DC/DC converter of fig. 22.

Fig. 24 is an oblique view of a power electronics arrangement integrated into a motor-generator according to an embodiment of the present invention.

FIG. 25 is a battery management system state of a charge estimation control loop according to an embodiment of the present invention.

FIG. 26 is a flow chart of accessory operating speed selection according to an embodiment of the present invention.

FIG. 27 is a flow chart of a control strategy for operation of a motor-generator and engine-independent engine accessories in accordance with an embodiment of the present invention.

Fig. 28 is a schematic diagram of a fluid circuit of a FEMG system configured with a dynamic heat generator according to an embodiment of the present invention.

Detailed Description

Front end motor generator system embodiments.

Fig. 1A is a schematic diagram showing components of an embodiment of a FEMG system according to the present invention. Fig. 1B is a schematic diagram of several FEMG system components in the chassis of a commercial vehicle. In this arrangement, the engine accessories (including the gas compressor 1, the air-conditioning compressor 2, and the engine cooling fan 7, which are arranged to draw cooling gas through the engine coolant radiator 20) are drivingly driven by the pulley 5. The pulley 5 is positioned coaxially with a damper 6, the damper 6 being directly coupled to the crankshaft of an internal combustion engine 8. The accessories may be driven directly by the drive belt or be provided with their own on-off or variable speed clutches (not shown) that allow the accessories, individually configured with the clutches, to be partially or fully disengaged from the belt drive.

In addition to driving the accessory drive belt, a pulley 5 is coupled to a drive unit having a reduction gear 4 to transmit torque between a crankshaft end of the drive unit and an opposite end coupled to the motor generator 3 (for clarity, the drive unit housing is not shown in the figures). A disengageable coupling in the form of a clutch 15 is arranged between the crankshaft damper 6 and the pulley 5 (and thus between the drive unit and the motor-generator 3). Although schematically illustrated as axially separated components for clarity in fig. 1A, in this embodiment the crankshaft 6, clutch 15 and pulley 5 at least partially overlap one another in the axial direction, thereby minimizing the axial depth of the pulley-clutch-damper combination unit at the front of the engine. Actuation of the pulley clutch damper clutch 15 between its engaged and disengaged states is controlled by an Electronic Control Unit (ECU) 13.

On the electrical side of the motor-generator 3, the motor-generator is electrically connected to a power inverter 14, the power inverter 14 converting the Alternating Current (AC) produced by the motor-generator output into Direct Current (DC) that can be used in the energy storage and distribution system. Likewise, the power inverter 14 converts direct current from the energy storage and distribution system into an alternating current input in the opposite direction to power the motor-generator 3 as an electric motor for torque generation. The inverter 14 is electrically connected to an energy storage unit 11 (hereinafter, "energy storage"), and the energy storage unit 11 may receive energy for storage and output energy based on demand.

In this embodiment, the energy storage 11 comprises lithium-based energy storage cells having a nominal charging voltage of approximately 3.7V per cell (operating range of 2.1V to 4.1V), connected in series to provide a nominal energy storage voltage of 400 volts (operating voltage range of approximately 300V to 400 volts), with a storage capacity of electrical energy of between approximately 12 and 17 kilowatt-hours. Alternatively, the cells may be connected in series and parallel as needed to meet the application. For example, 28 modules with four series-connected cells per module may be connected in series and in parallel to provide energy storage that stores the same 17 kilowatt-hours of stored energy as in the first example above, but at a nominal operating voltage of 200V and twice the current output of the first example.

In addition to the relatively high capacity, low charge-discharge rate lithium-based energy storage cells, the energy storage portion 11 in this embodiment comprises a plurality of relatively low capacity, relatively high charge-discharge rate super capacitors to provide the energy storage portion with the ability to receive and/or discharge very large currents in short periods of time that cannot be handled by lithium-based energy storage cells (typically such cells are limited to charge/discharge rates of less than 1C to only a few C).

FEMG system hardware assembly embodiments.

Fig. 2A-2C show cross-sectional views of an embodiment of the clutch-pulley-damper unit 19 and an assembled configuration of the FEMG system hardware with the clutch-pulley-damper embodiment. In this embodiment, a gearbox 16 containing a reduction gear 4 receives the motor-generator 3 at a motor-generator end of the gearbox. The motor generator 3 is fixed to a housing of the gear box 16 with fasteners (not shown) such as bolts. The rotor shaft 18 of the motor-generator 3 engages the corresponding central hole of the adjacent coaxially positioned gear of the reduction gear 4 to allow torque transmission between the motor-generator 3 and the reduction gear 4.

At the crankshaft end of the gear case 16, in this embodiment, the reduction gear 4 coaxially aligned with the clutch-pulley-damper unit 19 is coupled to the pulley side of the clutch-pulley-damper unit 19 for common rotation by a bolt (not shown) passing through the coaxial reduction gear 4. The engine-side portion of the coupling (the portion having the crankshaft damper 6) is configured to be coupled to the front end of the engine crankshaft by fasteners or other suitable connection that ensures co-rotation of the engine-side portion 6 with the crankshaft. As described further below, the gear box 16 is separately mounted to a structure that maintains the clutch-pulley-damper unit 19 in coaxial alignment with the forward end of the engine crankshaft.

The cross-sectional view in fig. 2B is a view from above the FEMG front end hardware, and the oblique cross-sectional view in fig. 2C is a view at the crankshaft end of the gear box 16. In this embodiment, the gearbox, motor generator and clutch-pulley-damper unit assembly is arranged such that the motor generator 3 is positioned to the left of the engine crankshaft and to the front of the gearbox 16 (the side away from the front of the engine), wherein the motor generator 3 may be positioned in a space below or directly behind the engine coolant radiator 20 of the vehicle. Alternatively, to accommodate a different vehicle arrangement, the gearbox 16 may be mounted to the rear of the gearbox 16 along with the motor-generator 3, preferably in a space laterally to the left of the engine crankshaft (e.g., adjacent to an oil pan at the bottom of the engine). The gearbox 16 further may be provided with a double-sided motor-generator mounting feature so that a common gearbox design may be used in both vehicular applications with a front-mounted motor-generator and vehicular applications with a motor-generator mounted to the rear side of the gearbox.

An FEMG clutch-pulley-damper unit embodiment.

Fig. 3A-3C are views of the components of the clutch-pulley-damper unit 19 of fig. 2A-2C. When assembled, since the pulley 5, the engine-side portion 6 (hereinafter, the damper 6), and the clutch 15 are substantially axially overlapped, the unit is abnormally narrowed in the axial direction. In this embodiment, the pulley 5 has two belt driving portions 21 configured to drive an accessory drive belt (not shown), for example, one portion configured to drive the engine cooling fan 7 surrounding the clutch 15 and the other portion configured to drive other engine accessories such as the gas compressor 1. The drive belt portion 21 in this example concentrically surrounds the damper 6 and the clutch 15 (the belt drive portion 21 surrounding the damper 6 is omitted in fig. 2B and 2C for clarity).

Within the clutch-pulley-damper unit 19, the clutch 15 comprises two axially engaging dog

clutch elements

25, 26. As shown in the cross-sectional views of fig. 2A-2C, in this embodiment, the central core dog clutch element 25 is fixed for rotation with the damper 6 by a bolt extending from the FEMG gearbox side of the clutch-pulley-damper unit 19 through an axial bolt hole 28. The pulley 5 is rotatably supported on the central core element 25 by means of a bearing 34.

The engine-side part of the outer periphery of the central core dog clutch element 25 comprises external splines 29, which external splines 29 are arranged to engage internal splines 30 at the inner periphery of the axially movable dog clutch element 26. The external splines 29 and the internal splines 30 are constantly engaged so that the movable dog clutch element 26 rotates with the damper 6 while being axially movable along the damper rotation axis.

The movable dog clutch element 26 is also provided with axially forward dogs (dog)31, the dogs 31 being circumferentially distributed around the gearbox side (the side remote from the engine) of the element 26. These claws 31 are configured to engage spaces between corresponding claws 32 of the pulley 5 on the engine-facing side, as shown in fig. 3C. The movable dog clutch element 26 is biased in the engaged position in the clutch-pulley-damper unit by a spring 33 positioned between the damper 6 and the movable dog clutch element 26, as shown in fig. 2A. Fig. 2B and 2C show a clutch disengaged position in which the spring 33 is compressed as the movable dog clutch element 26 is displaced axially towards the damper 6.

In this embodiment, the clutch ejection rod 27 is concentrically positioned within the central core dog clutch element 25. The engine-side end of the ejector rod 27 is arranged to exert an axial clutch-disengaging force which overcomes the bias of the spring 33 to displace the dog clutch element 26 axially towards the damper 6, thereby disengaging its forward dog catch 31 from the corresponding dog catch 32 on the engine-facing side of the pulley 5. In this embodiment, the gearbox end of the clutch ejection lever 27 is provided with a bushing 303 and a bearing 304, the bearing 304 enabling the bushing to remain stationary while the ejection lever 27 rotates.

By the clutch actuator 22, the clutch ejection rod 27 is axially displaced to disengage and engage the dog clutch 15. In this embodiment, the clutch actuator 22 is pneumatically actuated, with compressed gas entering the fitting 305 above the clutch actuator diaphragm 41, pushing the center portion of the diaphragm 41 into contact with the throw-stem bushing 303 to axially displace the clutch throw-stem 27 toward the engine to disengage the clutch 15. When the compressed gas pressure is relieved from the clutch actuator, diaphragm 41 is retracted away from the engine, allowing biasing spring 33 to axially displace throw rod 27 and dog clutch element 26 toward pulley 5 to re-engage

clutch dogs

31, 32 so that pulley 5 rotates with damper 6.

Fig. 4 shows an alternative embodiment of the clutch-pulley-damper unit 19, wherein the clutch 15 is a so-called wet multiplate clutch. The wet multiplate clutch comprises friction and driven plates 23 keyed in an alternating manner to the inner periphery of the pulley 5 and to the outer periphery of the central portion of the damper 6. The clutch plates 23 are biased in compression in the axial direction by a spring 24 between the damper 6 and the clutch actuator 22 (in this embodiment, a pneumatically actuated clutch actuation piston). Biasing the stacked friction and driven plates together by spring 24 engages clutch 15 and causes pulley 5 and damper 6 to rotate in unison with one another about the axis of rotation of the engine crankshaft. When hydraulic pressure is applied to clutch actuator 22 (on the FEMG gearbox side of the actuator), spring 24 is compressed, allowing alternating clutch friction and driven plates 23 to axially disengage and thereby placing clutch 15 in a disengaged state, i.e. a state in which pulley 5 and damper 6 rotate independently.

In this embodiment, hydraulic pressure is supplied through oil, and this oil also serves to cool and lubricate the gearbox reduction gears and their associated bearings, and to cool the friction and driven plates of the wet multiplate clutch. The application of hydraulic pressure is controlled by a solenoid valve (not shown) in response to a command from the FEMG electronic control unit 13. The clutch 15 is sized to ensure that a significant amount of torque that can be transmitted between the engine crankshaft and the motor-generator will be accommodated by the clutch without slippage. Up to this point, due to the axially overlapping arrangement of the clutch-pulley-damper unit 19, the cooling design of the unit should be configured to ensure adequate cooling of the clutch plates during all operations. While cooling is provided by oil circulating in the gearbox in this embodiment, other forced or passive cooling arrangements may be provided as long as the desired clutch temperature is maintained below the operating temperature limit of the clutch.

A FEMG gearbox embodiment.

Fig. 5 is a detailed cross-sectional view of the bearing arrangement at the crankshaft end of an embodiment of the FEMG gearbox 16. Fig. 6A-6C and 7 show oblique views of an embodiment of the gearbox in which a pair of gearbox clam shell shells 35 enclose the reduction gear 4, the reduction gear 4 comprising a pulley end gear 36, an idler gear 37 and a motor-generator end gear 38.

While any gear ratio that fits within the available space for a particular engine application may be provided while providing the desired ratio of crankshaft speed to motor-generator speed, in this application the gear has a ratio of 2: a drive ratio of 1. The gears 36-38 may be spur gears, helical gears, or other gear teeth (such as double helical herringbone gear teeth) as desired to suit the requirements of a particular FEMG system application. Such requirements include gear noise limits required to meet government noise emissions or driver comfort limits that can be met with helical gears, mechanical strength limits such as tooth stress limits, or axial thrust limits that can be met with double helical chevron gear teeth that produce equal and opposite axial thrust components.

The gearbox housing rotatably supports each of the reduction gears 36-38 with a bearing 39. The pulley end gear 36 comprises a plurality of through holes 40 in a circumferential ring inside its gear teeth, the plurality of through holes 40 corresponding to the holes in the front face of the pulley 5 of the clutch-pulley-damper. These holes receive fasteners configured to rotationally fix pulley-end reduction gear 36 to pulley 5 for co-rotation when driven by the crankshaft and/or by the motor-generator.

The pulley-end reduction gear 36 has a central aperture in its center through which a pneumatically powered dog clutch actuation diaphragm 41 is positioned at the front face of the gearbox housing. The pneumatic diaphragm 41 axially extends and retracts a piston (not shown) arranged to engage the cup 27 on the dog clutch element 26 to control engagement and disengagement of the clutch 15 of the clutch-pulley-damper unit 19. The diaphragm 41 is shown in fig. 5 as being covered by the pneumatic clutch actuator 22, while fig. 7-8 show a simpler, tiny diaphragm cover 42 with a compressed gas connection on its face, which is particularly suitable for space-constrained FEMG applications. Regardless of the diaphragm cover design, the diaphragm 41 functions by compressed gas in a chamber above the front face of the diaphragm that is generated when the clutch actuator 22 or cover plate 42 is installed over the diaphragm hole at the front face of the gearbox housing. Admission and release of compressed gas may be controlled by solenoid valves (not shown) in response to commands from the FEMG control module 13. Although the clutch actuation mechanism is a pneumatically actuated diaphragm in this embodiment, the invention is not limited to a particular clutch actuator. For example, an electromechanical actuator may be used, such as an electric solenoid configured to extend an actuator rod to disengage a clutch member.

Fig. 5 and 8 provide further details of mounting the pneumatic diaphragm actuator of this embodiment. In this embodiment, the engine side of the diaphragm mounting ring 45 is configured to support the front bearing 39 associated with the pulley-end reduction gear 36 and receive the diaphragm 41 at the front side thereof. The bearing 39 may be retained and axially supported by any suitable means, such as a snap ring, or, as shown in FIG. 5, by a nut 46. Once the mounting ring is secured in the large hole in the front face of the gearbox housing clam shell plate 35 as shown, the pulley end reduction gear 36 and its bearings 39 and diaphragm 41 are axially fixed relative to the housing of the gearbox 16.

At the motor-generator end of the gear case 16, a shaft hole 43 aligned with the rotational axis of the motor-generator-end reduction gear 38 is provided in at least one of the housing clam shell plates 35, as shown in fig. 6A-6C and 7. Shaft bore 43 is sized to allow a rotor shaft (not shown in this figure) of motor-generator 3 to enter gearbox 16 and engage motor-generator end gear 38 for common rotation.

The FEMG gearbox may be cooled and lubricated by oil. The oil may be stored in a self-contained oil sump or, alternatively, in a remote location, such as an external reservoir or the oil tank of the engine, if the engine and gearbox share the same oil source. Oil may be circulated throughout the gearbox by the movement of the gears or by a pump that distributes pressurized oil, such as an electric or mechanical pump driven by the rotation of the reduction gears, and may cool the clutch plates of the wet clutch in addition to lubricating and cooling the gears. Further, the gearbox may be provided with an accumulator ensuring that a reserve of pressurised oil remains available to actuate, for example, the clutch of the clutch-pulley-damper unit when the pressure generated by the pump is not immediately available. In such embodiments, a solenoid valve controlled by the FEMG control module may be used to release pressurized oil to operate an actuator of the hydraulic clutch.

FIG. 9 illustrates an example of a commercially available gearbox showing an alternative motor-generator mounting arrangement in which the motor-generator mounting flange 44 provides the ability to mount the motor-generator to the gearbox with fasteners without having to run the fasteners through into the gearbox housing.

In the above embodiment, the end reduction gears 36, 38 are in constant mesh engagement via the idler gear 37. However, the present invention is not limited to this type of single reduction parallel-axis gearbox. Rather, other torque power transmission arrangements are possible, such as a chain or belt drive, or a drive with components such as a torque-transmitting shaft aligned at an angle to the axis of rotation of the switchable coupling (e.g. a worm gear drive with a transmitting shaft rotating on an axis perpendicular to the axis of rotation of the switchable coupling), as long as they can withstand the torque to be transmitted without being so large that the axial depth of the gearbox becomes unacceptably large. This alternative gearbox arrangement may also be used in embodiments where the motor-generator 3 is not aligned parallel to the axis of rotation of the switchable coupling but is instead positioned on the gearbox 16 and aligned as required to facilitate installation in areas of limited space (e.g. the motor-generator is attached at one end of the gearbox with its axis of rotation aligned with a gearbox torque transfer shaft that is not parallel to the axis of rotation of the switchable coupling).

The invention is not limited to a constant mesh arrangement with a fixed reduction ratio, other arrangements may be used, such as variable diameter pulleys (similar to those used in some vehicle constant speed transmissions) or internally disengageable gears, as long as the axial depth of the gearbox does not interfere with the position of the FEMG system components in the region of the front of the engine.

In the preferred embodiment, the reduction ratio of the FEMG gearbox reduction gears 36-38 is 2: 1, which is a ratio selected to better match the crankshaft rotational speed to the efficient operating speed range of the motor-generator 3.

FEMG system hardware installation embodiment.

As described above, preferably, the FEMG assembly is positioned such that the motor generator 3 is positioned in the region of the engine room offset downward and to the lateral side of the vehicle chassis rail supporting the engine. Fig. 10 illustrates such an arrangement as viewed from the front toward the rear of the vehicle. The figure shows the relationship between the motor generator 3 and the crankshaft 47 of the engine 8 (positioned axially behind the gearbox 16), oil pan 48, longitudinal chassis rails 49 and transverse engine mounts 50 in this embodiment

In the above FEMG arrangement, the crankshaft 47, the clutch-pulley-damper unit 19, and the engine-side reduction gear 36 are positioned on the same rotation axis. To ensure that this relationship is maintained, the FEMG gearbox should be positioned forward of the engine in a manner that ensures that there is no relative movement between the engine and the gearbox, either transverse to the axis of rotation of the crankshaft or about the crankshaft axis.

While the FEMG gearbox may be mounted in a manner that does not directly connect the gearbox to the engine (e.g., by suspending the FEMG gearbox from a bracket connected to chassis rails holding the engine), it is preferred to directly couple the gearbox to adjacent vehicle frame members or to the engine block. An example of a corresponding arrangement of the FEMG gearbox to the engine mounting bracket and mounting holes in the gearbox is shown in figures 10-14.

In fig. 10, the FEMG gearbox 16 is secured directly to the engine 8 by fasteners 306 against rotation or lateral movement relative to the engine 8. Fig. 11 shows an alternative approach in which a torque arm 307 (also known as a tie rod) is attached at one end to an anchor point 308 of the FEMG gearbox 16 and at the opposite end to the adjacent frame rail 49, providing non-rotational support of the gearbox 16.

A further alternative FEMG mounting method is shown in figure 12. In this embodiment, the mounting bracket 51 is provided with bolt holes 52, the bolt holes 52 being arranged around the bracket to align with corresponding holes in the engine block 8, which receive fasteners to provide an engine-centric fixed support for the FEMG gearbox. In this example, the flat bottom of the mounting bracket 51 is arranged to be positioned on top of a resilient engine mount, as is commonly used in commercial vehicle engine mounting. The engine-side portion of the mounting bracket 51 is the portion of the bracket that must extend under and/or around the clutch-pulley damper unit to reach the FEMG gearbox mounting bracket portion, to which the gearbox may be coupled, while ensuring that there is sufficient clearance available within the bracket to allow the clutch-pulley damper unit to rotate therein.

Fig. 13 and 14 schematically illustrate the location of the FEMG gearbox 16 on such a bracket and the corresponding allocation of fastener holes around the FEMG reduction gear 36 and the FEMG side of the mounting bracket 51. Fig. 13 and 14 both show the circumferential arrangement of corresponding fastener holes 53 on the FEMG gearbox 16 and the FEMG gearbox side of the FEMG mounting bracket 51. In fig. 14, the engine-side portion and the FEMG gear case-side portion of the mounting bracket 51 are linked by an arm 54 (not shown in these figures for clarity) that extends parallel to the engine crankshaft axis in the space of the clutch-pulley-damper unit 19 that does not rotate. The schematically illustrated arm 54 is intended to convey the mounting bracket placement concept, it being understood that the connection between the engine side and the FEMG gearbox side of the mounting bracket may be any configuration that joins the front and rear sides of the bracket in a manner that fixes the FEMG gearbox relative to the movement of the engine crankshaft. For example, the arm 54 may be a rod welded or bolted to the front and/or rear side of the bracket, or the arm may be part of an integrally cast component extending around the clutch-pulley-damper unit 19. Preferably, the mounting bracket 51 is designed such that its FEMG gearbox side portion has a fastener hole pattern that facilitates the FEMG gearbox to rotate ("time-out") relative to the bracket as needed to index the gearbox at various angles to accommodate various engine arrangements for the FEMG components, such as retrofitting the FEMG system to various existing vehicle or stationary engine applications.

An FEMG system motor generator and an electronic control embodiment.

An example of a motor generator suitable for attachment to the motor generator end of a FEMG gearbox is shown in fig. 15. In this embodiment, the FEMG gearbox side 55 of the motor generator 3 includes a plurality of studs 56, the plurality of studs 56 configured to engage corresponding holes in a mounting flange on the gearbox, such as the mounting flange 44 shown on the exemplary gearbox 16 in fig. 9. To transmit torque between the rotor of the motor-generator 3 and the motor-generator-side reduction gear 38, the rotor bore 57 receives a shaft (not shown) that extends into a corresponding bore in the reduction gear 38. The shaft between the reduction gear 38 and the rotor of the motor generator 3 may be a separate member, or may be integrally formed with the rotor or the reduction gear. The shaft may also be pressed onto one or both of the rotor and the reduction gear, or may be able to be easily disconnected by using a displaceable connection such as an axial spline or a threaded connection.

In this embodiment, the motor generator 3 also houses several electronic components of the FEMG system, as well as a low voltage connection 58 and a high voltage connection 59 that serve as electrical interfaces between the motor generator 3 and the control and energy storage components of the FEMG system, as discussed further below.

Preferably, the motor generator 3 is sized to provide at least engine starting, hybrid power generation, and engine accessory drive capability. In one embodiment, as shown in the graph of FIG. 16, a motor-generator having dimensions of about 220mm in diameter and about 180mm in longitudinal depth provides approximately 300Nm of torque at 0rpm for engine starting and up to approximately 100Nm near 4000rpm for operating engine accessories and/or providing supplemental torque to the engine crankshaft to assist in propelling the vehicle. The reduction ratio of the FEMG gear box is 2: 1, the motor-generator speed range is well matched to the speed range of a typical commercial vehicle engine, 0 to approximately 2000 rpm.

FEMG motor-generator design is constrained by thermal, mechanical and electrical considerations. For example, the required torque output from the motor may be in the range of 50Nm to 100Nm only when the motor generator is driving one or more demanding engine accessories, such as an engine cooling fan, while the temperature rise of the motor generator during starting is relatively limited by a relatively short period of starting operation. Without sufficient motor-generator cooling, the temperature rise may be significant during sustained high torque output conditions. For example, at 15A/mm²The adiabatic temperature rise may be around 30 c at a current density J in the motor-generator winding of (1). Therefore, it is preferable that the FEMG motor generator be provided with forced cooling such as the example shown in fig. 17, in which engine coolant or cooling oil (such as oil from a gearbox oil circuit) is circulated through a cooling fluid passage 60 in the motor generator. It is particularly preferable that a portion 61 of the cooling passage 60 is also delivered to provide cooling to the FEMG system electronic components mounted on the motor generator 3.

The type of motor selected may also introduce limitations or provide specific advantages. For example, in an induction electric motor, using an inverter (with a corresponding increase in flux), the breakdown torque can be increased by 10-20%, and typically the breakdown torque is higher, for example, 2-3 times the machine rating. On the other hand, if a permanent magnet machine is selected, excessive stator excitation current must be avoided to minimize the possibility of demagnetization of the permanent magnet. While physical placement and operating temperature can affect the point where demagnetization is problematic, typically, current values greater than twice the rated current must be experienced before significant demagnetization can be noted.

In view of this factor, the preferred embodiment of the motor-generator 3 will have a performance that operates at 150% of its rated operating range. For example, the motor-generator may have a rated speed of 4000rpm, a top speed rating of 6000rpm (corresponding to a maximum engine speed of 3000 rpm), and a capacity of around 60KW at 4000 rpm. Such a motor generator operating at a rated voltage of 400V would be expected to provide a continuous torque output of approximately 100Nm, an engine crank torque of 150Nm for a short duration such as 20 seconds, and a peak cranking torque at 0rpm of 300 Nm.

In this embodiment, the FEMG motor-generator 3 and other components of the FEMG system are controlled by a central FEMG control module 13, an electronic controller ("ECU"). Relative to the motor generator, the FEMG control module: (i) controlling operation modes of the motor generator, including a torque output mode in which the motor generator outputs torque to be transmitted to the engine accessories and/or the engine crankshaft via the clutch-pulley-damper unit, a power generation mode in which the motor generator generates electrical energy for storage, an idle mode in which the motor generator generates neither torque nor electrical energy, and a shutdown mode in which a speed of the motor generator is set to 0 (a mode possible when there is no engine accessory operation demand and a clutch of the clutch-pulley-damper unit is disengaged); and (ii) control the engagement state of the clutch-pulley-damper unit (via components such as solenoids and/or relays, as required by the type of clutch actuator employed).

The FEMG control module 13 controls the motor-generator 3 and the clutch-pulley-damper unit 19 based on various sensor inputs and predetermined operating criteria, as discussed further below, such as the state of charge of the energy storage portion 11, the temperature level of the high voltage battery pack within the energy storage portion, and the current or anticipated torque demand on the motor-generator 3 (e.g., the torque required to achieve a desired engine accessory rotational speed to achieve a desired level of engine accessory operating efficiency). The FEMG control module 13 also monitors the speed signals associated with the motor-generator and engine crankshafts to minimize the potential for damaging clutch components by ensuring that the crankshaft-side and pulley-side portions of the clutch are speed matched before signaling the clutch actuator to engage the clutch.

The FEMG control module 13 communicates with other vehicle electronics modules using digital and/or analog signals, all to obtain data for its motor-generator and clutch-pulley-damper control algorithms, and to cooperate with other vehicle controllers to determine the optimal combination of overall system operation. In one embodiment, for example, the FEMG control module 13 is configured to receive a signal from a brake controller to operate the motor-generator in a generating mode to provide regenerative braking in lieu of applying mechanical braking of the vehicle in response to a relatively low braking demand from the driver. The FEMG control module 13 is programmed to, upon receipt of such a signal, assess the current vehicle operating state and provide a signal to the brake controller indicating that regenerative braking is being initiated, or alternatively, that electrical energy generation is not desired and that the brake controller should command actuation of the mechanical brakes or retarder of the vehicle.

Fig. 18 provides an example of integration of electronic control in the FEMG system. In this embodiment, the FEMG control module 13 receives and outputs signals that communicate with sensors, actuators, and other vehicle controllers across the CAN bus of the vehicle. In this example, the FEMG control module 13 communicates with the battery management system 12, with the engine control unit 63 and with the power management components of the FEMG system, the battery management system 12 monitoring the state of charge of the energy storage 11 and other related energy management parameters, the engine control unit 63 monitoring engine sensors and controlling the operation of the internal combustion engine, the power management components of the FEMG system including the power inverter 14, the power inverter 14 handling AC/DC conversion between the DC energy storage and electrical consumers (not shown) of the vehicle, the AC motor generator 3 and the DC portion of the electrical bus. The FEMG control module 13 further communicates with a DC-DC converter 10 of the vehicle, the DC-DC converter 10 managing the distribution of electrical energy suitable for the voltage of the consumer, e.g. from 400V power of the energy storage 11 to 12V required by the 12V battery 9 of the vehicle and various 12V devices of the vehicle such as lights, radios, power seats.

Fig. 18 also illustrates communication of data input into the FEMG system control algorithm from sensors 64 (e.g., motor generator clutch position sensor 101, motor generator speed sensor 102, engine accessory clutch position 103, gas compressor state sensor 104, dynamic heat generator state sensor 105, FEMG coolant temperature sensor 106, FEMG coolant pressure sensor 107, and 12V battery voltage sensor 108), the sensors 64 being associated with the motor generator 3, the clutch of the clutch-pulley-damper unit 19, the various engine accessories 1, and the 12V battery 9.

Many of the signals received and exchanged by the FEMG control module 13 are transmitted to/from other vehicle devices 66 (e.g., brake controller 111, retarder controller 112, electronic gas control (EAC) controller 113, transmission controller 114, and dashboard controller 115) across the vehicle's SAE J1939 standard compliant communication and diagnostic bus 65. Examples of such sensors and the operating signals and variables exchanged and their corresponding sources are provided in table 1.

TABLE 1

The outputs from the FEMG control module 13 include commands to control the generation of electrical energy or torque output from the motor-generator 3, commands to engage and disengage the clutch of the clutch-pulley-damper unit 19, commands to engage and disengage the clutch 120 of the individual engine accessories 1 (discussed further below), and commands to operate the FEMG coolant pump 121.

And the FEMG control module of the FEMG system component controls the system.

In addition to controlling the motor-generator and its clutching connection to the engine crankshaft, in this embodiment the FEMG control module also has the ability to control the engagement state of any or all of the individual clutches that connect the engine accessories to the pulley 5 driven accessory drive belt, allowing the FEMG control module to selectively connect and disconnect different engine accessories (such as the air conditioning compressor 2 or the compressed gas compressor 1 of the vehicle) to and from the accessory drive depending on the operating state of the vehicle. For example, the algorithm of the FEMG control module may prioritize electrical energy generation and determine that some engine accessories do not need to operate when operating conditions permit. Alternatively, the FEMG control module is programmed to operate the engine accessories in response to a priority scenario requiring operation of the accessories, even though doing so would not result in high overall vehicle operating efficiency. An example of the latter would be to receive a compressed gas storage tank low pressure signal, necessitating engaging the clutch of the gas compressor and operating the pulley 5 at a sufficiently high speed to ensure that sufficient compressed gas is stored to meet the safety requirements of the vehicle (e.g. sufficient compressed gas for pneumatic braking operation). Another example would be to instruct the motor-generator and engine cooling fan clutch to operate the engine cooling fan at a high enough speed to ensure adequate engine cooling, thereby preventing engine damage.

Preferably, the FEMG control module is provided with engine accessory operating performance data, for example in the form of a stored look-up table. With the engine accessory operating efficiency information, the ability to variably control the operating speed of the motor-generator to virtually any desired speed when the clutch-pulley-damper unit clutch is disengaged, and knowledge of the operating state of the vehicle received from the sensors and the vehicle's communication network, the FEMG control module 13 is programmed to determine and command a combination of a preferred motor-generator speed and an engine accessory clutch engagement state that results in a high level of overall vehicle system efficiency for a given operating condition.

While overall system efficiency may be improved by having a large number of individual engine accessory clutches (including on-off, multi-stage, or slip-variable clutches), even without an individual accessory clutch, the FEMG control module 13 may use the engine accessory performance information to determine a preferred motor-generator operating speed that causes the pulley 5 to rotate at a speed that meets the current system priority, whether that priority enhances system efficiency to ensure that the heaviest engine accessory demands are met, or a motor-generator operating speed that rotates at a speed of another priority, such as to sufficiently begin charging the energy storage portion 11 at a predetermined time prior to an anticipated event that ensures that sufficient electrical energy is stored before the vehicle stops. For example, in this embodiment, the FEMG control module is programmed to determine the current state of charge of the energy storage portion 11 and the amount of time available before the anticipated driver rest period, and initiate charging of the motor generator of the energy storage portion 11 at a rate that will result in sufficient energy to support the anticipated duration of the vehicle system operation (such as sleeping car air conditioning) reset period when the engine is off (e.g., 8 hours overnight rest period).

A similar principle applies regardless of the number of individual engine accessory clutches, i.e., the FEMG control module may be programmed to operate the motor-generator 3 and the clutch-pulley-damper unit clutch 15 in a manner that satisfies the priorities established in the algorithm, regardless of whether there are several, many, or no individual engine accessory clutches. Similarly, various priority schemes may be programmed into the FEMG control module to suit a particular vehicle application. For example, in a preferred embodiment, the energy efficiency prioritization algorithm may go beyond a simple analysis of what configuration of pulley speeds and individual engine accessory clutch engagement provides optimal operating efficiency for the highest priority engine accessories, but may also determine if there is a pulley speed that maximizes overall vehicle efficiency while still meeting vehicle system requirements, then operation of the combination of engine accessories at the compromised pulley speeds will result in greater overall system efficiency while maintaining meeting the requirements of the priority accessories, i.e., operating each of the individual engine accessories at speeds that deviate from their respective highest efficiency operating points.

FEMG power generation, storage, and voltage conversion embodiments.

The relationship between the power electronics and the current distribution in this embodiment is shown in more detail in fig. 19. The three-phase alternating current motor generator 3 is connected to an AD/DC power inverter 14 via a high voltage connection. The electric power generated by the motor generator 3 is converted into a high-voltage DC current to be distributed on the DC bus network 67. Conversely, a DC current may be supplied to the bidirectional power inverter 14 to be converted into an AC current to drive the motor generator 3 as an electric motor that generates torque.

A known embodiment of a bi-directional AC/DC power inverter, such as inverter 14, is shown in fig. 20. The arrangement includes a six IGBT power transistor configuration with switching signals provided from a controller (such as from the FEMG control module 13) to the control lines 68A-68F based on a vector control strategy. Preferably, the control module for power inverter 14 is located no more than 15cm away from the IGBT board of the power inverter. If it is desired to minimize electrical noise on the DC bus 67, a filter 69 may be interposed between the power inverter and the remainder of the DC bus.

Fig. 19 also shows the high voltage lines between the two main DC bus connections, the power inverter 14 and the energy storage 11. The double-headed arrows in this figure indicate that DC current may be transferred from power inverter 14 to energy storage 11 to increase its state of charge, or may flow from energy storage to DC bus 67 for distribution to power inverter 14 to drive motor-generator 3 or to other DC voltage consumers connected to the DC bus. In this embodiment, a DC/DC voltage converter 70 is provided between the DC bus and the energy storage 11 to adapt the DC voltage on the DC bus generated by the motor-generator 3 to the preferred operating voltage of the energy storage. Fig. 19 also shows that the DC bus 67 may also be connected to a suitable voltage converter, such as an AC-DC voltage converter 309 that converts electrical energy from an offboard power supply 310, such as a stationary charging station, to a voltage on the DC bus 67 to allow charging of the energy storage portion independent of the motor-generator 3 when the vehicle is parked.

In addition to the bi-directional flow of DC current to and from the energy storage portion 11, the DC bus 67 also supplies high voltage DC current to vehicle electrical consumers, such as vehicle lights, radios and other typical 12V power supplies, and to 120V AC current devices, such as a driver sleeping compartment air conditioner and/or refrigerator or cooking surface. In both cases, a suitable voltage converter is arranged to convert the high voltage on the DC bus 67 into a suitable DC or AC current with a suitable voltage. In the embodiment shown in fig. 19, the DC/DC converter 71 converts a DC current having a rated voltage of about 400V into a DC current of 12V to charge one or more conventional 12V batteries 72. Thus, the vehicle's typical 12V load 73 is desirably provided with a required amount of 12V power without the need for the engine to be equipped with a separate engine-driven 12V alternator, further saving weight and cost while increasing overall vehicle efficiency. Graph 21 illustrates a known embodiment of a forward DC/DC converter, such as DC/DC converter 71, in which the FEMG control module 13 controls the conversion of the high DC voltage from the DC bus 67 to the 12V output 75 by providing a FEMG control signal to a transistor drive circuit 74 to manage current flow through the primary winding 76 of the transformer 77 of the DC/DC converter.

The bi-directional high voltage DC/DC converter 70 is a voltage converter of the so-called "buck plus boost" type, such as the known electrical arrangement shown in fig. 22. Fig. 23 shows how, when the electronically controlled switch S in fig. 22 is actuated, the input voltage Vin drives the corresponding current oscillation through the inductor L and the capacitor C in a pulsed manner, resulting in a continuous output voltage vo that oscillates smoothly around the reference voltage < vo >.

The desire to keep the distance between the power inverter 14 and the three AC phase lines of the motor generator short can be met by integrating several electronic components into the housing of the motor generator, as shown in fig. 24. On the side of the motor generator opposite the side facing the gear box 16, the leads for the three AC phases 78A-78C are present and connected to the high voltage portion 79 of the circuit board 84 (in fig. 24, the portion of the circuit board 84 to the left of the dotted line). To the right of the AC phase connection, the power inverter is integrated into the circuit board 84, while the IGBT bank 80 is positioned under the IGBT driver circuit 81.

Also co-located on the circuit board 84 is a portion 82 containing an electromagnetic interference (EMI) filter to suppress electrical noise and a DC power capacitor, and an embedded microcontroller 83 of the femgoecu. The dashed line represents the electrical insulator 85 of the high voltage portion 79 from the low voltage portion 86, which communicates with the rest of the FEMG system and vehicle components via electrical connection 58. The high voltage and high current generated by the motor generator 3 or received by the motor generator 3 from the energy storage 11 are transferred from the high voltage portion 79 of the circuit board 84 to the high voltage connector 59 via a circuit path (not shown) behind the outer surface of the circuit board.

The advantages of this high degree of integration of the motor-generator and the power electronics are a simplified and less costly installation, a minimized electrical loss across the longer distance connection between the motor-generator and the power electronics, and the ability of the existing forced cooling by the motor-generator to provide cooling to the power electronics without the need for additional dedicated electronic cooling arrangements.

An FEMG system energy storage and battery management controller embodiment.

The storage battery for the energy storage 11 in this embodiment is based on lithium chemistry, specifically, a lithium ion battery. Lithium ions have several advantages over conventional batteries such as lead-acid chemistry, including lighter weight, better compatibility with "fast charge" charge rates, high power density, high energy storage and return efficiency, and long cycle life.

The energy storage 11 is sized to receive very large currents from the motor-generator 3 and supply very large currents to the motor-generator 3, whereas a crank-driven motor-generator may produce kilowatts of electrical power, and when the clutch-pulley-damper unit is disengaged from the engine crankshaft, the energy storage-powered motor-generator may require 300 peak amps of high current to start the diesel engine, in addition to requiring a sufficiently high current to produce 100Nm or more of torque to drive the engine accessories.

While the super capacitor is able to handle the peak current demand of the FEMG system, the battery portion of the energy storage portion 11 is sized to provide a continuous current discharge rate and total energy output to meet the most demanding current demand. Based on experience with commercial vehicle operation, in this embodiment the battery portion of the energy storage 11 is sized to ensure good operation at an equivalent 58KW for ten minutes per hour (corresponding to the power requirement to operate the engine cooling fan at its highest speed at intervals only by the motor generator, and the use of concurrent air conditioning and gas compressors). Calculations show that, assuming an operating efficiency of 95% for power inverter 14, discharging 58KW per hour for 10 minutes would require 10KWh of energy to be withdrawn from energy storage 11. With a system voltage of 400V, this amount of discharge requires the energy storage battery to have a storage capacity of approximately 15Ah (ampere-hours).

In addition to calculating the minimized battery capacity to meet the expected maximum vehicle demand, the design of the battery portion of the energy storage portion 11 also takes into account baseline operating requirements. For example, there is an operational desire to incompletely discharge the energy storage battery, both to avoid encountering situations where the energy storage cannot meet emergency vehicle needs (such as the inability to start the engine when the motor generator is operated as an engine starter), and to avoid potential cell damage due to discharge below the minimum cell operating voltage recommended by the cell manufacturer (typically no less than 1.5-2V/cell for 3.8V-4.2V lithium-based cells). Thus, the design of the energy storage portion of the present embodiment includes a requirement that the maximum discharge requirement does not discharge the battery portion of the energy storage portion below 50% of capacity. This request results in the energy storage unit 11 having a battery capacity of 30 Ah.

In the case of a design target of 30Ah and using a lithium ion battery with a discharge rate of 33Ah each individual rated voltage of 3.8V and a discharge capacity of 0.3C, such a cell weighing 0.8Kg and rectangular dimensions 290mm x216mm x 7.1mm, determining the desired energy storage capacity (30 Ah at 400V) can be provided by packaging 4 individual cells in series to yield a 33Ah battery module rated voltage of 15.2V, and then connecting 28 the battery modules in series to provide a battery pack with a capacity of 33Ah at a rated voltage of 15.2V/module x28 module 425V (typically, the actual operating voltage is equal to or below 400V). The battery pack weighs approximately 90Kg (without a housing) and has a volume of approximately 50 liters (liter), which is easily accommodated with the chassis rails of a commercial vehicle.

The energy storage 11 is provided with a Battery Management System (BMS) 12. The BMS control module monitors the state of charge and temperature of the battery pack, processes battery maintenance tasks such as cell balancing (monitors and adjusts the state of charge of individual batteries or battery packs), and communicates battery pack state information to the FEMG control module 13. The battery management system 12 may be co-located with the FEMG control module 13 or located at another location remote from the battery pack in the energy storage 11; however, mounting the battery management system 12 with the energy storage 11 allows for modular energy storage system deployment and replacement.

Another design consideration with respect to the energy storage portion 11 receiving and discharging large amounts of high voltage current is the need for cooling. In the present embodiment, among the FEMG components, the energy storage portion 11, the motor generator 3, the power inverter 14, the gear box 16, and the clutch 15 of the clutch-pulley-damper unit 19, which require cooling, the battery storage 11 has the greatest need for cooling to avoid damage due to exceeding the temperature condition. The preferred temperature operating range for lithium ion batteries is-20 ℃ to 55 ℃. These temperatures are compared to operating temperature limits of about 150 ℃ for the motor-generator 3, 125 ℃ for the power inverter 14, and 130 ℃ for the gearbox 16 (and, if the clutch is an oil bath wet clutch, the clutch 15). In this embodiment, significant complexity and cost savings are achieved by having all of the main FEMG components cooled by oil circulating in the gearbox for lubrication and cooling. This is possible if the battery pack of energy storage 11 receives cooling oil as the first component downstream of the gas/oil radiator to dissipate heat from the oil, i.e. before the cooling oil recirculates and absorbs heat from other FEMG components in the oil cooling circuit. This arrangement ensures that the battery pack receives a flow of cooling oil at a temperature that allows the battery pack to remain below 55 ℃ before the oil encounters higher motor generator, power inverter and gearbox temperatures.

An embodiment of an energy storage state of charge decision algorithm for a FEMG system.

The state of charge of the energy storage section battery may be determined in various ways. FIG. 25 is an example of a known battery management system state of charge estimation control algorithm that may be used in the present invention. In a first step S101, the battery management system 12 is initialized ("on") at start-up. Step S102 represents the estimation of the state of charge of the battery by the so-called "coulomb counting" method of the BMS, here by sampling the cell and stack voltages (V, T) and temperature to establish an estimated baseline charge level, and tracking from this initial point the amount of current (I) drawn into and out of the stack.

However, while this method of tracking the state of charge has the advantage of providing real-time, very accurate monitoring of current flow in a relatively inexpensive technology, it does not provide a reliable indication of the amount of charge lost from the battery due to the phenomenon of self-discharge of the battery cell as a result of undesired chemical reactions. Since this phenomenon is strongly temperature dependent and can lead to substantial charge losses that are not detected in step S102, in this embodiment the battery management system also performs an additional state of charge estimation step S103, a so-called "before loop" method. In this state of charge estimation method, the open circuit voltage of the battery is measured and this voltage is compared to a stored voltage/state of charge value to provide an estimate of the battery charge level, which inherently accounts for previous self-discharge losses. Further, by comparison with previously stored information, the rate of self-discharge may be estimated, and from that self-discharge rate, the state of health of the battery may be estimated (i.e., a high self-discharge rate indicates that the health of the battery is reduced compared to when new).

The "before loop" approach has the disadvantage that it cannot be easily used in real time because the battery pack of the energy storage 11 is used to receive and discharge high voltage current as needed to support ongoing vehicle operation. As a result, only the open-voltage based state of charge and state of health estimation in step S103 is performed when the cells of the energy storage portion are in a state where no current is being received by or discharged from the battery pack. If the step S103 estimation is not possible, the battery management system routine proceeds to step S104 and the most recent battery state of charge and state of health step S103 estimation is used for subsequent calculations.

Based on the cell and pack voltages, temperatures, current inputs and outputs from step S102, and the most recent step S103 correction factors that explain self-discharge effects, in step S104 the battery management system calculates the appropriate charge and discharge power limits available for operation of the energy storage 11 within the FEMG system, and executes a cell balancing algorithm to identify battery cells requiring charge equalization and apply appropriate selective cell charging and/or discharging to equalize cell voltages within the 4-cell module and between the 28 modules. Cell balancing is particularly important when lithium ion batteries are in use, as such cells can age and self-discharge at different rates from one another. As a result, over time, individual battery cells may develop different abilities to accept charge, i.e., situations that may result in more than one cell in a module (or between different modules) being overcharged while others are undercharged. In either case, a significantly overcharged or undercharged battery may be irreparably damaged.

In step S105, the battery management system 12 communicates battery pack status information to the FEMG control module 13, including information about the required power limit and temperature for the current state of charge of the battery. In parallel with step S106, the cell data is stored in memory for future cell monitoring iterations. Once the battery state determination and cell balancing routines are complete, control returns to the beginning of the charge estimation control loop so that the self-discharge rate data is available at the beginning of the loop for use in subsequent steps.

FEMG system operating modes and control algorithm embodiments.

In this embodiment, the FEMG system operates in several modes, including a generator mode, a motor mode, an idle mode, an off mode, and a stop/start mode. The mode selected for the current operating conditions is based at least in part on the current state of charge of the energy storage 11, wherein the FEMG control module 13 is programmed to identify a minimum charge level based on data received from the battery management system 12, in this embodiment a minimum charge level of 20% of the charge capacity, an intermediate charge level of 40%, and a maximum charge level of 80% (this level being selected to ensure that the energy storage is protected from battery overcharge, particularly in the event that a single cell self-discharge has generated a cell imbalance condition).

In the generator mode, whenever the energy storage state of charge is below the minimum charge level, the clutch 15 is engaged and the motor-generator 3 is driven to produce electrical energy for storage, and the clutch will remain engaged until an intermediate state of charge level is reached. Once the intermediate state of charge level is reached, the FEMG control module 13 switches between generator, motor, idle and off modes as needed. For example, if motor-generator 3 is operating to drive the engine accessories with clutch 15 disengaged, the FEMG control module commands a switch to generator mode and engages clutch 15 to charge energy storage portion 11 when a braking, deceleration, or negative torque condition occurs (as long as the energy storage portion 11 state of charge remains below the maximum state of charge level).

To provide infinitely variable speed control while in the motor mode with clutch 15 disengaged, the FEMG control module 13 regulates the magnitude and frequency of the current delivered by the inverter 14 to the motor-generator 3. This capability allows the motor generator 3 to operate in a manner that drives the pulley 5 so that the engine accessories are driven by the pulley 5 at speeds and torque output levels that meet the demands of the current operating conditions without the waste of energy due to operation at unnecessarily high speeds and torque output levels. The FEMG system has the additional benefit of variable output control of the motor-generator 3 which minimises the amount of stored electrical energy that must be delivered from the energy storage portion 11, reduces the energy storage charging requirements and extends the length of time that the energy storage portion 11 can supply high voltage current before a minimum state of charge is reached.

If the charge level in the energy storage 11 is above a minimum level, no braking, deceleration or negative torque condition exists, and the engine accessories do not require torque from the motor-generator 3, the FEMG control module 13 triggers an idle mode in which the clutch 15 of the clutch-pulley-damper 19 is disengaged and the motor-generator is "off," i.e., not operated to produce electrical energy for storage or to produce torque for driving the engine accessories.

In either of the generator, motor or off mode, if the engine requires torque output assistance from the motor-generator, the FEMG control module may command the clutch 15 to engage and, at the same time, command electrical energy to be supplied from the energy storage 11 to the motor-generator to be converted to supplemental torque to be transmitted to the engine crankshaft.

The FEMG control module is additionally programmed to prevent unwanted over-discharge of the energy storage 11. For example, in this embodiment, when the torque and speed requirements of the engine cooling fan 7 are above 90% of its designed maximum requirements, the clutch 15 of the clutch-pulley-damper 19 is engaged to mechanically drive the engine cooling fan 7 (and thus also other engaged engine accessories) from the engine crankshaft. This allows the motor-generator 3 to operate in an idle or generator mode in order to avoid deep discharges that potentially damage the energy storage 11, and to avoid state-of-charge conditions in which the stored energy is insufficient to support engine-off loads (e.g., engine start-up or sleeping compartment support during engine-off rest periods).

An additional operating mode is a start mode for initially starting the cold engine and start-stop functionality (i.e. shutting down the engine after stopping and restarting upon resumption of travel). In this embodiment, the start-stop function is controlled by the FEMG control module 13. When appropriate conditions exist (e.g., energy storage 11 state of charge is above a minimum threshold for engine start, vehicle speed is 0 for a sufficient period of time, transmission is neutral or transmission clutch is disengaged, doors are closed, etc.), the FEMG control module signals the engine control module to shut down the engine to minimize fuel consumption and undesirable engine idle noise. When the vehicle is to resume motion, as indicated by a signal such as brake pedal release or operation of the transmission clutch, the FEMG control module 13 commands engagement of the clutch 15 and energy is supplied from the energy storage portion 11 to operate the motor generator 3 to produce a large amount of torque for engine start. Delivery of engine cranking torque occurs from a motor generator initial rotational speed of 0, with or without an engine accessory operating demand during the engine off period (in which case there would be no need for pulley-crankshaft speed matching, since both sides of the clutch would be 0 speed). Alternatively, if the motor-generator 3 has driven the pulley 5 to power the engine accessories during an engine-off period, the motor-generator 3 may be commanded to slow below the rotational speed at which clutch damage may occur when the clutch 15 is engaged. In the case of a dog clutch, this may be at or near 0 speed, while a wet multiplate clutch may be better compatible with some relative motion between the pulley side and the stationary crankshaft side of the clutch.

The FEMG system further may store sufficient energy to allow the dynamic heat generator to operate to warm up the cold engine prior to a cold start, significantly reducing the drag the cold engine may have on the motor generator during the cold start. The use of a dynamic heat generator also creates the potential for a reduction in the size, weight, and cost of the motor-generator by reducing the peak cold-start torque requirements that the motor-generator is designed to provide beyond the expected operating conditions of the vehicle.

Peak cold start torque requirements that the motor generator is designed to provide beyond the expected operating conditions of the vehicle may also be reduced by other assisting means. For example, if the engine starting torque is supplemented by a pneumatic starter motor powered by the compressed gas storage of the vehicle, the size of the motor-generator may be reduced. The size of the pneumatic starter motor can be minimized to ensure that it can be positioned with the FEMG component at the front of the engine, as the pneumatic starter motor need not be sized to be able to start the engine by itself. Such cold start assistance can be lower cost and weight than the option of maintaining a conventional electric engine starter motor to rotate the engine flywheel, and has a negligible impact on the system energy efficiency improvement that can be obtained with a FEMG system.

An engine accessory operating speed and a motor generator operating speed determination algorithm of the FEMG system.

An embodiment of the FEMG system control strategy is described with the aid of the flow charts of fig. 26 and 27, followed by a brief discussion of the underlying basis of the strategy.

As a general matter, higher fuel savings may be achieved by maximizing the amount of time that engine accessories and other components are electrically driven, rather than by the mechanical power of the engine that is traditionally provided. Control strategies that improve power deployment are an important part of achieving these improvements. The method of the present invention is to maximize the number of components that can be electrically driven while minimizing the number of electromechanical machines required to drive the accessories. Thus, in the present invention, a single electric motor (such as motor-generator 3) provides both mechanical torque output and electrical energy generation, rather than providing most or all of the power-requiring components of the vehicle with their own electric motor. This single motor generator approach is combined with a control strategy that ensures that the most demanding or highest priority engine accessories or other component needs are met, while at the same time minimizing inefficient operation of other accessories or components by adapting their operation to the conditions that have been set to meet the maximum demand. In the control strategy discussed below, individual engine accessories are provided with clutches that allow them to be selectively closed, driven at a speed dictated by the accessory with the greatest demand or priority, or at a reduced speed using a variably engaged clutch, depending on the accessory.

When the engine accessories are driven by the engine crankshaft, i.e., when the clutch 15 is engaged, each engine accessory is mechanically driven under a "baseline" or "raw" control strategy (OCS) corresponding to how those accessories would operate in a conventional engine application without the FEMG system. In this strategy, accessories with individual clutches are operated according to their individual baseline control schemes, while their clutches are fully engaged, partially engaged, or disengaged in the same manner as in non-hybrid internal combustion engine applications.

In contrast, when the clutch-pulley-damper unit clutch 15 is disengaged and the engine accessories begin to be powered by the motor-generator 3 using energy from the energy storage 11, the FEMG control module variably controls the speed of the pulley 5, whereupon the engine accessory drive belt drives the belt in a manner that meets current vehicle requirements, without providing more accessory drive torque than is required under current operating conditions. Under such a Variable Speed Control (VSC) strategy, the FEMG control module 13 uses stored data regarding the operating characteristics of individual engine accessories to simultaneously control the various accessories in a manner that further minimizes the amount of electrical energy required to drive the motor generator 3 in the motoring mode (the FEMG control module 13 may control the accessories directly, or issue signals to other modules such as the engine control module, to command desired accessory operations). In addition, although the most efficient or desired operating speed has been plotted for each accessory, because the motor-generator 3 drives all engine accessories on the same belt at one belt speed, when one accessory is operating at its optimal speed, other accessories may be operating at a non-optimal operating point. Thus, the FEMG control module 13 compares the preferred operating speed of each accessory to their speed when driven by the motor-generator 3 at a speed sufficient to meet the maximum accessory demand, and determines whether the individual clutches of the accessories can be actuated to yield an individual accessory speed that is closer to the preferred operating speed of the individual accessories. If possible, the FEMG control module will override the normal accessory clutch control strategy and activate the accessory clutch as needed to deliver the individual accessory speed that provides improved efficiency.

Selecting an appropriate engine accessory speed begins by determining a desired ideal operating speed for each accessory for the current operating conditions, using control logic such as that shown in fig. 26.

Once the accessory speed determination algorithm is initiated, the FEMG control module 13 retrieves data from its memory 201 regarding the current vehicle operating conditions obtained from the vehicle' S sensors and other controllers and determines the current operating conditions, most of which is provided to the FEMG control module 13 via the CAN bus according to the SAE J1939 network protocol in step S201. This operation is to determine whether the current operating conditions require operation of a specific accessory, such as an engine cooling fan, in step S202. If the accessories are turned on, the routine proceeds to step S203 to determine whether the accessories are coupled to the accessory drive via a separate accessory multi-speed clutch.

If the FEMG control module 13 determines that there is such an accessory clutch in step S203, the routine proceeds to step S204 for determining what the desired accessory operating speed would be for the determined operating conditions. In performing step S204, the FEMG control module 13 accesses information 202, for example in the form of a look-up table, a characteristic curve, or a mathematical function, from which information 202 the operating speed of the accessory at which the accessory is effectively operating under the current operating conditions can be ascertained. In step S205, when its clutch is fully engaged, the FEMG control module 13 compares the determined desired accessory operating speed to the speed of the accessory, and adjusts the accessory clutch to set the appropriate corresponding clutch operating state (e.g., degree of clutch slip in a variable slip clutch, or a particular reduction ratio in a clutch with multiple discrete speeds, such as a 3-speed clutch). After appropriately adjusting the accessory clutch as appropriate, in step S207, the FEMG control module 13 checks to see whether the FEMG system motor mode has ended (i.e., determines whether the motor generator 3 continues to drive the accessory drive portion via the pulley 5). If the system is also operating in motor mode, control returns to the beginning of the accessory speed determination process to continue evaluating accessory speed needs in view of ongoing operating conditions. If the motor mode is determined to be ended in step S207, the routine of FIG. 26 ends.

If in step S203 the FEMG control module 13 determines that there is no multi-speed accessory clutch (i.e., accessory speed cannot be adjusted relative to engine speed), the routine proceeds directly to step S206 to instruct the clutch of the accessory to fully couple the accessory to the accessory drive. Control then passes to step S207, where the motor mode evaluation described above is performed.

The algorithm of FIG. 26 is a component of the overall engine accessory control strategy of the present embodiment shown in FIG. 27. At the start of the FEMG system algorithm, the FEMG control module 13 retrieves data received from the battery management system 12 from its storage 201 to determine the state of charge of the energy storage 11 in step S301. Next, in step S302, the FEMG control module 13 retrieves data obtained from the sensors and other controllers of the vehicle regarding the current vehicle operating conditions from the memory 201 to determine the current operating conditions of the engine operation (in this embodiment, the evaluation in step S302 provides the information required in step S201 of the accessory speed determination algorithm of fig. 26, and thus need not be repeated below in step S322).

After determining the current operating conditions, the FEMG control module 13 determines the mode in which the FEMG system should operate and thus commands engagement or disengagement of the clutch 15 of the clutch-pulley-damper unit 19 (step S303). The determination of how the accessories are to be operated with the engine driving the pulley 5 may be performed by the FEMG control module 13 or another accessory control module if the clutch 15 is to be in an engaged state with the pulley 5 coupled to the damper 6 (and thus to the engine crankshaft). In fig. 27, at step S311, the FEMG control module 13 transfers control of the engine accessory clutch to the Engine Control Module (ECM) of the vehicle, which may determine the engine accessory speed in a manner comparable to the Original Control Strategy (OCS). After the accessory control is manually turned off in step S311, the process ends in step S312.

If it is determined at step S303 that the motor-generator 3 is to electrically drive the accessories (i.e., "motor mode" in the "disengaged state in which the clutch 15 of the clutch-pulley-damper unit 19 is decoupled from the damper 6 and thus decoupled from the crankshaft"), the motor-generator 3 is controlled using a gear change control (VSC) strategy in this embodiment.

Here, the VSC policy is implemented by first determining a preferred accessory operating speed for each accessory in step S322 by considering information on the characteristics of all accessories and the variables evaluated in step S321.

In step S323, the FEMG control module 13 determines whether at least one accessory that can be driven by the motor generator 3 is "on", that is, in a state where it is to be driven by the motor generator 3 via the pulley 5. If there is no accessory operation demand under the current conditions, control returns to step S303.

If it is determined in step S323 that at least one accessory is in the "on" state, the FEMG control algorithm determines in step S324 whether one or more accessories need to be driven by the motor generator 3 (i.e., one or more accessories are "on"). If only a single accessory has a torque demand, the control process proceeds to a subroutine that focuses on the operation of only that "on" accessory. Thus, in step S325, the motor generator speed required to drive the single accessory at its preferred operating speed is calculated, in step S326, the individual drive clutch of the accessory is instructed to be fully engaged, and in step S327, the motor generator 3 is instructed to operate at the speed determined in step S325. Because the speed of the motor generator is variably controlled in this embodiment, the pulley speed 5 can be accurately set at the level required to drive the highest demand engine accessories. Control then returns to the beginning of the control algorithm.

If it is determined in step S324 that more than one accessory needs to be driven by motor generator 3, then according to the VSC strategy, the FEMG control module 13 determines for each accessory what motor generator speed will be required to drive the accessory at its individual preferred accessory operating speed in step S328. The calculated speeds are then compared to identify the highest motor generator speed demand from the "on" accessories in step S329. Then, in step S330, the FEMG control module 13 commands the individual clutch of the accessory requiring the highest motor generator speed to be fully engaged, and in step S331, commands the highest motor generator speed required for the operation of the motor generator 3. As part of the VSC strategy, in step S332 the FEMG control module controls operation of the remaining individual accessory clutches equipped with "on" accessories of the individual clutch to adapt the operation of these accessories to the required maximum motor generator speed set in step S329. For example, because the set motor-generator speed (the speed required to service the accessory requiring the highest motor-generator speed) is higher than the speed required for the remaining accessories to operate at their preferred speed, if the accessories are equipped with a separate clutch that can be partially engaged (e.g., "slipped"), the clutch can be instructed to allow sufficient slip to bring the speed of its accessories closer to their preferred operating speed (as determined in step S322). Control then returns to the beginning of the control algorithm.

An example of performing the above method for the case of a vehicle with three accessories driven from a crankshaft pulley, an engine cooling fan, an air conditioning compressor, and a gas compressor is provided below.

In this example, the engine cooling fan is equipped with a fan clutch (e.g., a viscous fan clutch) with multiple speed capabilities, such as a three speed or variable speed clutch. Air conditioners and gas compressors have separate "on-off" clutches with only engaged and disengaged states. The FEMG control module 13 controls the operating state of each accessory clutch. The final speed of each accessory is a function of the pulley drive ratio, the motor-generator speed, and the nature of the accessory clutch (i.e., "on-off," variable slip, or multiple reduction ratio steps).

In this simplified example, for a given set of vehicle operating conditions, the preferred operating point for each accessory and the corresponding motor-generator speed at which the preferred operating point is obtained are: the engine cooling fan is operated at 1050rpm (this fan speed requires motor generator speed 1050 rpm/ratio between fan pulley and pulley 5 of 1.1, multiplied by gearbox reduction ratio 2: 1 of 1909 rpm); the air conditioning compressor was operated at 1100rpm (corresponding to a motor generator speed of 1294 rpm); and the gas compressor was operated at 2000rpm (corresponding to a motor generator speed of 2667 rpm).

If the FEMG control module 13 determines that the operation of the gas compressor is highest in priority under given conditions (e.g. when the amount of stored compressed gas is approaching a safe level that is minimal for pneumatic brake operation), the FEMG control module 13 will command the motor generator 3 to operate at 2667rpm required to support the 2000rpm speed requirement of the gas compressor. However, the motor generator speed is generally higher than the speed required by the engine cooling fan or the air conditioner compressor (at a motor generator speed of 2667rpm, the engine cooling fan speed and the air conditioner compressor speed are 1467rpm and 2267rpm, respectively). Having accessed the engine accessory operating curve and depending on the nature of the other accessory clutches, the FEMG control module 13 may then adjust the engagement of the clutch to operate the other accessories closer to their preferred operating speeds. For example, if the fan is equipped with a variable slip clutch, the FEMG control module may command the fan clutch slip amount to provide a preferred engine cooling fan speed of 1100 rpm. Similarly, while the air conditioner compressor may only have an "on/off" clutch and thus may be driven at 1467rpm (rather than the preferred speed of 1050 rpm) when its clutch is engaged, the FEMG control module may control operation of the "on/off" clutch of the air conditioner compressor to reduce the duty cycle of the air conditioner compressor to a point where the current air conditioning demand may be met by periodically operating the air conditioner at only 1467 rpm. The method provides the FEMG control module with the ability to meet the needs of the most demanding current engine accessories while reducing the energy waste caused by driving other accessories at higher speeds than necessary or at unnecessarily high duty cycles (e.g., 100%).

In a further example, the engine may be equipped with an accessory that cannot be disconnected from the drive belt driven by pulley 5. In this case, the FEMG control module 13 may determine in consideration of an operation curve that can obtain the maximum overall system energy efficiency through trade-off. For example, assume that the gas compressor currently has the greatest demand, and it is preferable to operate the gas compressor at a speed of 2000rpm, where the compressor is most efficient. If the FEMG control module then determines that the engine coolant pump is driven at 2667rpm, the motor-generator speed may operate at an undesirably low efficiency (i.e., operate at a pump speed that significantly increases the energy consumption of the pump) and vehicle conditions allow the gas compressor to be operated at a lower speed (e.g., where the current need is to "cap" the compressed gas storage tank rather than meet an urgent, safety-related compressed gas demand), the FEMG control module may command the engine coolant pump to operate at a lower motor-generator speed (e.g., 2400rpm) at a higher level of efficiency even though the gas compressor is operating at that speed at a slightly reduced efficiency, with the result that the overall combined engine coolant pump and gas compressor operation increases overall system efficiency as compared to operating these accessories at a motor-generator speed of 2667 rpm.

Dynamic heat generator embodiments.

An embodiment of a fluid circulation loop 400 in a FEMG system with a dynamic heat generator is shown in fig. 28. In this embodiment, the dynamic heat generator 401 is arranged to be driven by an engine accessory drive belt (not shown here) via a pulley 402. The DHG is further equipped with a separate clutch 403 that allows the DHG401 to be selectively disengaged from the pulley 402 and the engine accessory drive. The opposite end of the rotational shaft of the drive pulley of the DHG401 drives a pump 404, the pump 404 providing a pressurized supply of DHG working fluid (in this embodiment, engine coolant) to an inlet 405 of the DHG 401. In this integrated DHG and pump embodiment, there is also provided a solenoid operated bypass valve 406 and a discharge line with a check valve 408, the bypass valve 406 being arranged to send the output from the pump 404 into the fluid circuit downstream of the DHG outlet 407.

Downstream of the DHG401 is a distribution manifold 411, the distribution manifold 411 receiving either a flow of heated coolant from the DHG or a flow from the DHG bypass. The flow is then distributed to various circuit branches via solenoid valves 411A-411D as needed, and finally returned to the coolant reservoir 420. The coolant reservoir 420 supplies flow to the inlet of the DHG pump 404.

In fig. 28, there are four fluid circuit branches shown: a cabin branch 432, the cabin branch 432 being arranged to provide coolant to a cabin heat exchanger 433 in the sleeping compartment and/or the vehicle cabin; an engine branch 442, through which the coolant passes through the cooling channels of the engine 8; an FEMG coolant branch 452, the FEMG coolant branch 452 being arranged to provide coolant to components of the electrical portion of the FEMG system, including the battery of the energy storage portion 11, the coolant channel 61 of the FEMG power electronics, and the motor generator 3; and a heat exchange branch 462, the heat exchange branch 462 being arranged to allow superheat to be rejected from the system back from the heat exchange surface 463 and/or via a cooler 465 in the form of a heat exchanger transferring heat to a cooling fluid. In this embodiment, cooler 465 receives an expansion valve 473 in refrigerant loop 472 also having condenser 475 and refrigerant downstream of air conditioner compressor 471 driven by air conditioner compressor pulley 477 and clutch 479. The clutch and pulley may be of the same design as the clutch and pulley used for the DHG 401. Each of the

branches

432, 442, 452, 462 is provided with a

respective check valve

434, 444, 454, 464 that prevents reverse flow from the reservoir 420 through the branch.

Since the air conditioning compressor 471 can be operated by the motor-generator 3 in conjunction with the DHG pump 404, including the heat exchange branch 462 provides the system with the ability to cool the coolant under certain conditions, such as when the engine is off.

In this embodiment, the energy storage 11, the power electronics 61 and the motor-generator 3 are served by the same coolant branch line 452, however, any and/or all of these components may be supplied by separate, dedicated branches from the manifold 411, as desired for a particular vehicle application.

The operation and capabilities of the FEMG/DHG embodiment of FIG. 28 will now be described. The operation and capability of the DHG-equipped FEMG system is not limited to this description.

In this embodiment, the DHG401 may be controlled in at least three ways.

First, because the heat generated by the shear forces acting on the fluid in the DHG is proportional to the rotational speed of the DHG, the speed of the DHG can be varied to control the heat input to the fluid. If fluid heating is not desired, the DHG can be turned "off" by disengaging the DHG clutch 403.

Second, the amount of fluid flowing through the DHG401 may be varied in order to vary the amount of temperature rise of the fluid passing through the DHG. In this way, the fluid temperature is controlled while the torque input to the DHG (and thus the power consumption of the DHG) is kept constant.

Third, the volume of fluid in the DHG401 may vary between empty and full. If the DHG is empty, the rotor inside the DHG will turn and no appreciable power will be consumed, since no fluid is sheared. As the filling level of the DHG401 increases, the power consumption and fluid temperature will increase. Once the DHG401 is full, control of the amount of heat generated in the fluid may be controlled by another one of the control methods.

In this embodiment, the thermal management of the components of the FEMG system mainly utilizes the first and third of the above control methods. Preferably, the operation of the DHG clutch 403 and the variable speed control of the engine accessory drive with the motor-generator 3 are used to control the heat generated by the DHG401 and allow the DHG401 to be turned off when not needed.

When the DHG clutch 403 is engaged, the DHG pump 404 draws coolant from the reservoir 420. The DHG401 performs work in the coolant received from the pump 404 and is output from the DHG at a higher temperature than it entered. At high speeds, the DHG401 may convert 90% of the mechanical power input into the DHG. The coolant output from the DHG401 (or coolant bypassing the DHG via the bypass solenoid valve 406) then enters the manifold 411. The path of the coolant after the manifold depends on which of the solenoid valves 411A-411D is open. The positions of these solenoid valves are set according to heating and/or cooling needs as determined by algorithms processed in an electronic controller, such as the FEMG electronic control unit 13. Examples of heating and/or cooling requirements and associated component operations include the following:

heating energy storage (e.g., battery): typically, the energy storage will have a temperature gradient such that its rated C (or rated capacity) decreases as the temperature decreases. For example, a cell may only deliver a rating of 2C at lower temperatures of-20℃ and a rating of 1C at-40℃. In this mode, the DHG clutch 403 is engaged to drive the DHG401 and the pump 404, and the bypass solenoid valve 406 is closed. The manifold solenoid valve 411B is opened to allow heated coolant from the DHG401 to pass through the coolant branch 452 to the energy storage portion 11, while the remaining

manifold solenoid valves

411A and 411C-411D are either closed (since no heating and/or cooling is required in their respective branches) or selectively opened to address other system heating and/or cooling needs. Also in this mode, when manifold solenoid valve 411A is closed, air conditioning clutch 479 may be engaged or disengaged depending on whether there is a cooling demand outside the FEMG thermal management circuit (e.g., in a refrigerant loop branch providing air conditioning to a ventilation system of a commercial vehicle cab).

When the electronic control unit determines that the energy storage temperature must be increased in order to prevent an energy storage component, such as a battery, from reaching a temperature below which insufficient power delivery may occur, an energy storage heating mode may be used, as well as preheating the battery prior to vehicle operation prior to cold start.

Further, an energy storage heating mode may be used to provide cooling to the energy storage component when the component temperature is above the temperature of the coolant. This condition may exist even after the coolant is heated in the DHG401, and may exist when the DHG401 is operated in a manner that does not add appreciable heat to the coolant or the DHG is bypassed.

Heating the engine: in this mode, the DHG clutch 403 is engaged to drive the DHG401 and pump 404, the bypass solenoid valve 406 is closed, and the manifold solenoid valve 411C is opened to allow heated coolant from the DHG401 to pass through the coolant branch 442 to the engine 8, while the remaining manifold solenoid valves 411A-411B and 411D are closed (since no heating and/or cooling is required in their respective branches) or selectively opened to address other system heating and/or cooling needs. This mode is particularly useful for providing engine warm-up capability prior to engine cold start, but also provides the ability to prevent damage due to freezing conditions (by circulating heated coolant), and potentially reduces undesirable exhaust emissions during critical engine warm-up by shortening the time required to bring the engine and exhaust temperatures high enough for the emission control system to become efficient.

Heating sleeping compartments/cabins: for example, when an over-the-road truck is shut down overnight to rest the driver, it may be necessary to heat the sleeping compartment and/or cabin of the vehicle. In the sleeping car/cabin heating mode, the heat transported to the sleeping car/cabin may be provided by at least two sources, including harvesting waste heat from the engine that is now off and providing heat from the DHG 401. Preferably, the engine's waste heat is first used as a heat source to minimize the amount of stored electrical energy used to drive the DHG401, followed by DHG operation once the engine coolant temperature falls below the set point temperature. In addition, heat from the coolant loop 452 may also be used to facilitate sleeping compartment heating.

In this embodiment, in the first phase of operation, engine coolant, which may exceed 100 ℃, is circulated by the DHG pump 404 (driven by closing the DHG clutch 403) through the manifold solenoid valve 411C, the branch line 442 containing the engine 8 and the reservoir 420, and through the manifold solenoid valve 411D, the branch line 432 and the sleeping compartment/cabin heat exchanger 433. Flow to the sleeping car/cabin heat exchanger 433 may be necessary to be adjusted to achieve a desired sleeping temperature (e.g., a driver desired temperature below 27 ℃). At this stage, little or no heat is added to the coolant by the DHG401, which may be bypassed by opening the bypass solenoid valve 406 and/or by operating the DHG401 in a non-heating mode (e.g., the DHG is empty).

When the engine temperature drops below the set point temperature, a second phase of operation is entered in which the DHG401 generates heat, the bypass solenoid valve 406 is closed, and the manifold valve 411C is closed to stop the circulation of coolant through the engine 8. The set point temperature for switching between phases may be predetermined or established according to current ambient conditions. In any event, in order to ensure that the engine is easily started at the end of the rest period on cold weather, it may be desirable to establish an absolutely lower engine temperature limit, for example-10 ℃. The remaining manifold solenoid valves 411A-411C are closed (since no heating and/or cooling is required in their respective branches) or selectively opened to account for other system heating and/or cooling needs (e.g., if the energy storage temperature rises above the setpoint temperature at any time during operation of the motor-generator 3 to drive the DHG401 and/or the DHG pump 404, the manifold solenoid valve 411B may be opened to provide a cooling flow to the energy storage 11 while coolant continues to flow into the sleeping compartment/cabin branch 432).

Cooling of sleeping compartments/cabins: in this mode, the DHG clutch 403 is engaged to drive the pump 404 and the air conditioner compressor clutch 479 is engaged to circulate refrigerant in the refrigerant loop 472. Additionally, the DHG bypass solenoid valve 406 may be opened, closing flow to the DHG401, thereby minimizing DHG heating of the coolant. Bypassing the DHG401 (by the inherent pumping action of the DHG internal rotary fluid shear plate) also allows for potential venting of the DHG of fluid, thereby reducing DHG mechanical pumping, and as a result, reducing the drive torque power required by the engine accessory drive operating pump 404. Alternatively, if sufficient cooling capacity is available in branch line 462 to provide adequate sleeping cabin/cabin cooling regardless of whether the coolant has been heated in the DHG401, the DHG401 may be operated to provide heated coolant to components in other branch lines requiring heating when needed.

In the sleeping compartment/cabin cooling mode, the manifold solenoid valve 411A is opened to allow coolant (heated or not) to pass from the manifold 411 through the coolant branch 442A and the heat exchange surface 463 to the cooler 465 to reduce the overall temperature of the coolant, and the manifold solenoid valve 411D is opened to allow cooled coolant to pass into the branch 432 and through the sleeping compartment/cabin heat exchanger 433 before returning to the reservoir 420. Preferably, the manifold solenoid valve 411D is not opened until the electronic control unit determines that the temperature of the coolant is below the ambient temperature in the sleeping compartment/cabin (e.g., at a driver desired temperature above 4 ℃). As for the sleeping compartment/cabin heating mode, the flow in the branches may be adjusted as necessary to achieve the driver's desired sleeping compartment/cabin temperature, with the remaining manifold solenoid valves 411B-411C being closed (since no heating and/or cooling is required in their respective branches) or selectively opened to address other system heating and/or cooling needs.

In an alternative arrangement, instead of the coolant exiting the cooler 465 being delivered directly back to the reservoir 420, the coolant may optionally be delivered directly to a sleeping compartment/cabin heat exchanger disposed downstream of the cooler 465 (i.e., the sleeping compartment/cabin cooler need not be disposed in the branch 432, or a second separate sleeping compartment/cabin heat exchanger may be disposed downstream of the cooler 465). With this arrangement, when it is desired to reduce the overall coolant temperature more rapidly, the sleep cabin/cabin heat exchanger may directly receive the coldest coolant available before the coolant returns to the reservoir 420, or alternatively, the cooled coolant from the cooler 465 may bypass the sleep cabin/cabin heat exchanger to be delivered directly to the reservoir 420, thereby increasing the rate of active cooling in the reservoir and thus in the overall FEMG/DHG thermal management system loop. Further, in the event of overheating occurring in the vehicle, the system may operate in this manner, for example, to supplement the cooling capacity of the vehicle's engine coolant radiator to maintain the engine temperature below its maximum operating temperature (e.g., 82℃.).

Cooling the energy storage unit: in high temperature environments, the ambient air may not be cold enough to cool the energy storage and/or the power electronics and motor-generator, for which reason the system must be cooled. For example, the energy storage battery cell may have a maximum operating temperature limit of 55 ℃, while the power electronics and/or motor generator may have a maximum temperature limit of 70 ℃. In this mode, the manifold solenoid valve 411A is opened to allow coolant (heated or unheated) to pass from the manifold 411 through the coolant branch 452 and the heat exchange surface 463 to the cooler 465, and the manifold solenoid valve 411B is opened to allow coolant to pass through the energy storage 11, the power electronics 61 and the motor-generator 3 before returning to the reservoir 420. The remaining manifold solenoid valves 411C-411D are closed (since no heating and/or cooling is required in their respective branches) or selectively opened to address other system heating and/or cooling needs. The air conditioner compressor 471 may be electrically driven while the DHG401 is operating to circulate the coolant through the DHG pump 404 via

branches

452 and 462. A decrease in the temperature of the coolant passing through the cooler 465 in the branch 462 may entail a decrease in the temperature in the coolant reservoir 320 toward the desired coolant temperature, and a corresponding decrease in the temperature of the coolant (drawn from the reservoir 420) in the branch 451. As discussed further below, the flow in

branches

452, 462 may be adjusted as necessary to achieve a desired temperature of the coolant to the energy storage 11, power electronics 61, and motor-generator 3.

Alternatively, if cooling of the fluid via the heat exchange portion in branch 462 is not required to provide sufficient cooling to the energy storage portion or the power electronic/motor generator, solenoid valve 411A may be maintained in a closed state, separate clutch 479 of air conditioning compressor 471 may be disengaged to stop cooling of the refrigerant passing through cooler 465, or both of these actions may be taken.

The engine is heated. When starting the engine at cold ambient temperatures, the exhaust emissions of a cold engine are difficult to control until various emissions controls are above a minimum operating temperature (e.g., the lowest temperature at which the catalyst can operate on the exhaust constituents). Before the engine starts, the FEMG motor generator 3 may be used to drive the DHG401 to warm up the engine 8 by increasing the temperature of the coolant flowing through the engine 8 via the manifold solenoid valve 411C and the branch 442. To further speed up the engine up to operating temperature as quickly as possible, operation of the DHG401 may continue after the engine is started. Further, after starting the engine, engine heating may be increased by increasing the load on the engine (i.e., torque output demand), for example, by engaging the clutch-pulley-damper unit 19 such that the engine drives the DHG401 and the motor-generator 3, and the DHG401 operates at its maximum heat generation level (i.e., at its maximum torque demand from the engine accessory drive) while the motor-generator 3 charges the energy storage at a high charge rate.

The engine heating mode may also be used to prevent the engine from reaching a minimum temperature limit to avoid damage, for example, a minimum temperature limit of-23 ℃ to avoid damage due to coolant freezing. In these operations, the DHG401 may be operated at a relatively low power level to merely maintain the engine temperature above a minimum temperature limit for easy starting and more rapid warming of the engine, at least until the engine is to be started and a higher coolant temperature is desired.

When the engine heating mode changes, the DHG401 may be used to heat the energy storage 11 before or in parallel with heating coolant to warm up the engine. If the ambient temperature is extremely low and the engine is shut down for long periods of time, such as overnight, the engine may be extremely difficult to start. In the event that the ambient temperature is cold enough that the energy storage portion cannot immediately deliver the amount of electrical energy required to start the engine (e.g., because the battery in the energy storage portion has a much lower output capacity at cold temperatures), a relatively small amount of electrical energy may be drawn from the energy storage portion 11 to drive the DHG 401. The heated coolant produced by the DHG401 may then be passed through the manifold solenoid valve 411B and branch 452 to warm the energy storage portion 11, thereby increasing the temperature of the energy storage portion and the temperature-dependent output capacity (alternatively, the manifold solenoid valve 411C may be opened to simultaneously deliver heated coolant through the engine 8 to begin warming the engine). When the energy storage portion 11 is warm enough to output sufficient electric energy to start the engine, it may be attempted to start the engine, preferably, once the engine is started, then the DHG401 and the motor generator 3 are driven by the engine.

Table 2 below summarizes the above-described operating modes in this embodiment without requiring additional heating and/or cooling by components in other branches:

TABLE 2

In each of the above operating scenarios, the motor-generator 3 may drive the DHG at any suitable speed to meet the current heating and/or cooling demand. The motor generator speed determines the flow rate of the coolant pump 404 and the heat generated by the DHG401 and the bypass valve 406 determines whether the DHG is active, i.e., whether the system is in coolant heating or cooling mode. Thus, the control system may use the DHG401 in a thermostat manner, sensing temperature data at various locations and components in the FEMG system and controlling various valves, accessory clutches, clutch-pulley-damper units, and motor-generator speeds to meet current system temperature demands. Examples of system parameters that may be monitored and/or controlled include reservoir temperature, battery unit surface temperature, cabin or sleeping compartment temperature, engine oil temperature, DHG outlet temperature, DHG pump outlet pressure, and the like.

In a further development of the invention, the ability to limit the flow in the various branches is provided, for example, when more than one manifold valve is open but it is not desirable to maximize the flow in more than one branch line. In this case, more than one manifold solenoid valve 411A-411D may be operated to reduce flow in its respective branch, for example, by using Pulse Width Modulation (PWM) control signals.

In another embodiment, instead of utilizing torque supply from the engine crankshaft, the accessory drive may be powered by a shaft of a hybrid propulsion unit of the vehicle or other source of rotational energy.

The foregoing disclosure is illustrative of the present invention only and is not intended to be limiting thereof. Since such modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.

List of reference signs:

1 gas compressor

2 air-conditioning compressor

3 Motor generator

4 drive unit gear

5 belt wheel

6 damper

7 Engine cooling fan

8 Engine

9 vehicle battery

10 DC/DC converter

11 energy storage section

12 Battery management system

13 FEMG electronic control unit

14 AC/DC power inverter

15 Clutch

16 gear box

17 flanged shaft

18 rotor shaft

19 clutch-pulley-damper unit

20 engine coolant radiator

21 tape drive section

22 Clutch actuator

23 Clutch disc

24 clutch spring

25, 26 dog clutch element

27 Clutch throw-out lever

28 bolt hole

29 external spline

30 internal spline

31, 32 claw buckle

33 spring

34 bearing

35 clamshell gearbox housing

36 belt wheel end reduction gear

37 intermediate reduction gear

38 electric generator end reduction gear

39 bearing

40 holes

41 diaphragm

42 cover

43 axle hole

44 mounting flange

45 mounting ring

46 nut

47 crankshaft

48 oil pan

49 Chassis rails

50 Engine Mount

51 mounting bracket

52 holes

53 holes

54 support arm

55 motor generator gearbox side

56 mounting stud

57 rotor shaft hole

58 low voltage connection

59 high voltage connection

60 coolant channels

61 electron cooling channel section

62 Engine control Unit

64 sensor

65 SAE J1939 bus

66 vehicle equipment

67 DC bus

68A-68F control circuit

69 transistor control circuit

70 DC/DC voltage converter

71 DC/DC converter

7212V battery

7312V load

74 DC/DC converter transistor drive circuit

75 DC/DC converter output

76 transformer primary winding

77 Transformer

78 AC phase connection

79 circuit board

80 IGBT group

81 IGBT drive circuit

82 EMI filter and DC capacitor

83 FEMG control module microcontroller

101 motor generator clutch position sensor

102 motor generator speed sensor

103 engine accessory clutch position

104 gas compressor state sensor

105 dynamic heat generator state sensor

106 FEMG coolant temperature sensor

107 FEMG coolant pressure sensor

10812V battery voltage sensor

111 brake controller

112 reducer controller

113 EAC controller

114 variable speed controller

115 dashboard controller

120 individual engine accessory clutch

121 FEMG coolant pump

201 FEMG control module storage

202 FEMG control module operation parameter storage part

303 clutch throwing-out rod bushing

304 bus bearing

305 compressed gas fitting

306 fastener

307 Torque arm

308 anchor point

309 AC-DC converter

310 off-board power supply

400 fluid circuit

401 dynamic heat generator

402 DHG belt wheel

403 DHG clutch

404 DHG pump

405 DHG entry

406 DHG bypass solenoid valve

407 DHG Outlet

411 manifold

411A manifold solenoid valve

411B manifold solenoid valve

411C manifold solenoid valve

411D manifold solenoid valve

420 reservoir

432 sleeping car/cabin branch

433 sleeping compartment/cabin heat exchanger

434 check valve

442 engine branch

444 check valve

452 energy storage/electronic branch

454 check valve

462 heat exchange branch

463 heat exchange surface

464 check valve

465 cooler

471 air-conditioning compressor

472 refrigerant branching

473 expansion valve

475 condenser

477 air conditioner belt wheel

479 air-conditioning clutch

Claims

1. A hybrid electric front end motor-generator system, comprising:

an internal combustion engine including an engine crankshaft having a front end opposite a rear end where an engine flywheel is located, the engine configured to transmit torque from the rear end of the crankshaft to a torque consumer;

a motor generator;

a torque transfer section having a motor-generator end configured to receive the motor-generator and transfer torque between the motor-generator end and a coupling end of the torque transfer section; and

an integrated switchable coupling having a coupling axis of rotation arranged coaxially with a crankshaft axis of rotation, the integrated switchable coupling being positioned between the coupling end of the torque transmitting section and a front end of the engine crankshaft in a region adjacent the front end of the engine, the integrated switchable coupling comprising:

an engine-side portion coupled to the engine crankshaft,

a drive side portion coupled to the torque transmitting section coupling end, an

An engagement actuator configured to selectively engage the engine side portion with the drive side portion, at least a portion of the engagement actuator being concentrically surrounded by the drive side portion along the coupling axis of rotation;

an engine accessory drive arranged to be driven by the drive side portion of the integrated switchable coupling and to drive at least one engine accessory;

an energy storage system, the energy storage system comprising:

an energy storage portion configured to store electrical energy generated by the motor-generator and deliver the stored electrical energy to the motor-generator to produce a torque output from the motor-generator to the integrated switchable coupling, an

An electric energy conversion and distribution network configured to convert a current type of the electric energy transmitted between the motor generator and the energy storage section between an alternating current and a direct current when the electric energy is transmitted from the motor generator to the energy storage section, and to convert a current type of the electric energy transmitted between the motor generator and the energy storage section between a direct current and an alternating current when the electric energy is transmitted from the energy storage section to the motor generator; and

a front end motor-generator system controller configured to switch the integrated switchable coupling between an engaged state and a disengaged state and to control operation of the electrical energy conversion and distribution network during transfer of electrical energy between the motor-generator and the energy storage

Wherein the content of the first and second substances,

the at least one engine accessory including a dynamic heat generator arranged to be driven by the engine accessory drive to generate heat in a fluid passing between an inlet and an outlet of the dynamic heat generator,

the dynamic heat generator is in fluid communication with at least one vehicle component downstream of the dynamic heat generator outlet, the dynamic heat generator outlet configured to at least one of receive heat from the fluid and reject heat to the fluid.

2. The hybrid electric front end motor-generator system of claim 1, wherein

The dynamic heat generator outlet is in fluid communication with a manifold arranged to receive the fluid from the dynamic heat generator outlet and distribute the received fluid to the at least one vehicle component.

3. The hybrid electric front end motor-generator system of claim 2, wherein

The at least one vehicle component includes at least one of the internal combustion engine, the energy storage portion, the motor-generator, and at least one heat exchanger.

4. The hybrid electric front end motor-generator system of claim 3, wherein

The at least one heat exchanger includes at least one of a sleeper compartment/cabin heat exchanger and a cooler configured to remove heat from the fluid by heat exchange with at least one of a refrigerant and ambient air.

5. The hybrid electric front end motor-generator system of claim 3, wherein

The manifold is configured to distribute the fluid to the at least one vehicle component via at least one branch line upstream of the at least one vehicle component, and

each branch line includes a flow control valve upstream of the at least one vehicle component.

6. The hybrid electric front end motor-generator system of claim 5, wherein

The at least one branch line is arranged to direct the fluid to a fluid reservoir downstream of the at least one vehicle component, and

the dynamic heat generator is arranged to receive the fluid from the fluid reservoir at the dynamic heat generator inlet.

7. The hybrid electric front end motor-generator system of claim 6, wherein

The fluid is an engine coolant.

8. The hybrid electric front end motor-generator system of claim 7, wherein

The at least one branch line is a plurality of branch lines,

the at least one vehicle component is a plurality of vehicle components,

each of the plurality of branch lines includes at least one vehicle component of the plurality of vehicle components, and

the front end motor generator system controller is configured to,

controlling engagement of the integrated switchable coupling between the crankshaft and the engine accessory drive, and operation of the motor-generator to selectively drive the dynamic heat generator with torque supplied from at least one of the crankshaft and the motor-generator, and

controlling operation of each flow control valve in each of the plurality of branch lines to selectively supply the fluid to the plurality of vehicle components as a function of at least one of heating and cooling requirements of the plurality of vehicle components.

9. The hybrid electric front end motor-generator system of claim 8, wherein

The front end motor generator system controller is further configured to control an operating speed of the dynamic heat generator to control an amount of heat generated in the fluid passing through the dynamic heat generator when the dynamic heat generator is supplied with the driving torque from the motor generator.

10. The hybrid electric front end motor-generator system of claim 9, wherein

A bypass valve disposed between the fluid reservoir and the dynamic heat generator inlet is configured to selectively pass the fluid from the reservoir to the manifold without passing through the dynamic heat generator.

11. A method of operating a hybrid electric front end motor-generator system, the front end motor-generator system including an internal combustion engine of a vehicle having an integrated switchable coupling at a front of the engine, the integrated switchable coupling arranged to selectively engage a front end of an engine crankshaft on an engine side of the coupling to an engine accessory drive on a drive side of the integrated switchable coupling, the drive side of the integrated switchable coupling arranged to transmit torque to the engine accessory drive from a motor-generator laterally offset from an axis of rotation of the crankshaft, and to transmit torque to and from the crankshaft when the integrated switchable coupling is engaged, the method comprising the acts of:

determining, with a front-end electric motor-generator controller, an operating state of the vehicle based on operating state information received from at least one of a vehicle sensor and another controller of the vehicle;

determining, with the front end electric motor-generator controller, a current operating priority from the determined operating state, wherein the current operating priority is one of:

meeting safety requirements, the safety requirements including at least a requirement to maintain vehicle systems within system operating limits,

satisfying energy storage requirements including at least a requirement to maintain a state of charge of the energy storage at or above a first state of charge level,

meeting engine operating requirements including at least a requirement to maintain engine operating parameters within operating limits, the engine operating parameters including at least an engine coolant temperature, and

meeting driver comfort requirements including at least a requirement to maintain a climate condition of a passenger compartment of the vehicle within a desired temperature range;

selecting an operating mode of the hybrid-electric arrangement with the front-end motor-generator controller based on the determined current operating priority, wherein the determined operating mode is one of a plurality of motor-generator operating modes including at least one of an electrical energy generation mode, an engine accessory drive portion torque generation mode, a supplemental engine torque generation mode, and an idle mode; and

controlling operation of the motor-generator and the integrated switchable coupling in response to a command from the front end motor-generator controller to implement the selected operating mode,

wherein

The act of controlling operation of the motor-generator and the integrated switchable coupling comprises: placing the integrated switchable coupling into one of an engaged state in which torque is transmittable between the motor-generator and the crankshaft, and a disengaged state in which the motor-generator is disengaged from the crankshaft and torque from the motor-generator is transmittable to the drive side of the integrated switchable coupling to drive the engine accessory drive to thereby drive at least one engine accessory, and

the control actions include: determining a heating or cooling demand of at least one component of the vehicle disposed downstream of the dynamic heat generator, and controlling at least one of a speed of the dynamic heat generator, a flow rate of a fluid through the dynamic heat generator, a fill level of the dynamic heat generator, and an engagement state of a dynamic heat generator clutch disposed between the engine accessory drive and the dynamic heat generator to transfer thermal energy carried by the fluid to the at least one vehicle component to meet the heating or cooling demand.

12. A thermal management system for internal combustion engine applications, comprising:

an engine crankshaft of the internal combustion engine, the engine crankshaft having a front end opposite a rear end where an engine flywheel is located, the engine configured to transmit torque from the rear end of the crankshaft to a torque consumer;

an electric motor;

an engine accessory drive arranged to be selectively drivable by at least one of the crankshaft and the electric motor;

an integrated switchable coupling having a coupling axis of rotation arranged coaxially with a crankshaft axis of rotation, the integrated switchable coupling being positioned between the engine accessory drive and the front end of the engine crankshaft in a region adjacent the front end of the engine, the integrated switchable coupling comprising:

an engine-side portion coupled to the engine crankshaft,

a drive side portion coupled to the engine accessory drive, an

An engagement actuator configured to selectively engage the engine-side portion and the drive-side portion, at least a portion of the engagement actuator being concentrically surrounded by the drive-side portion along the coupling axis of rotation;

a dynamic heat generator arranged to be selectively driven by the engine accessory drive to generate heat in a fluid passing between an inlet and an outlet of the dynamic heat generator;

an electric power supply portion configured to supply electric power to drive the electric motor; and

a thermal management controller configured to control selective engagement and disengagement of the engine accessory drive with at least one of the integrated switchable coupling, the electric motor, and the dynamic heat generator according to predetermined engagement and disengagement criteria,

wherein the dynamic heat generator is in fluid communication with at least one component downstream of the dynamic heat generator outlet, the dynamic heat generator outlet configured to at least one of receive heat from the fluid and reject heat to the fluid.

13. The thermal management system of claim 12, wherein

The dynamic heat generator outlet is in fluid communication with a manifold arranged to receive the fluid from the dynamic heat generator outlet and distribute the received fluid to the at least one component.

14. The thermal management system of claim 13, wherein

The at least one component includes at least one of the internal combustion engine, the electrical energy supply, the electric motor, a heat exchanger arranged as a human occupied compartment, and a cooler configured to remove heat from the fluid by heat exchange with at least one of a refrigerant and ambient air.

15. The thermal management system of claim 14, wherein

The manifold is configured to distribute the fluid to the at least one component via at least one branch line upstream of the at least one component, and

each branch line includes a flow control valve upstream of the at least one component.

16. The management system of claim 15, wherein

The at least one branch line is arranged to direct the fluid to a fluid reservoir downstream of the at least one component, and

17. The thermal management system of claim 16, wherein

The fluid is a coolant of the internal combustion engine.

18. The thermal management system of claim 17, wherein

The at least one branch line is a plurality of branch lines,

the at least one component is a plurality of components,

each of the plurality of branch lines includes at least one of the vehicle components, and

the thermal management controller is configured such that,

controlling engagement of the integrated switchable coupling between the crankshaft and the engine accessory drive, and operation of the electric motor to selectively drive the dynamic heat generator with torque supplied from at least one of the crankshaft and the electric motor, and

controlling operation of each flow control valve in each of the plurality of branch lines to selectively supply the fluid to the plurality of components according to at least one of a heating demand and a cooling demand of the plurality of components.

19. The thermal management system of claim 18, wherein

The thermal management controller is further configured to control an operating speed of the dynamic heat generator to control an amount of heat generated in the fluid transferred through the dynamic heat generator when the dynamic heat generator is supplied with the drive torque from the electric motor.

20. The thermal management system of claim 19, wherein

21. A thermal management system for a vehicle, comprising:

a motor generator;

an accessory drive arranged to be selectively drivable by at least one of a crankshaft of an engine of the vehicle, the motor-generator and a shaft of a hybrid vehicle propulsion unit;

a dynamic heat generator arranged to be selectively driven by the accessory drive to generate heat in a fluid passing between an inlet and an outlet of the dynamic heat generator; and

a thermal management controller configured to control selective engagement and disengagement of the accessory drive with at least one of the dynamic heat generator and an air conditioning compressor arranged to be driven by the accessory drive according to predetermined engagement and disengagement criteria,

22. The system of claim 21, wherein

The motor generator is an electric motor.

23. The system of claim 21, wherein

The at least one component includes at least one of a power supply portion arranged to supply power to the motor generator, a power electronic unit electrically connected between the power supply portion and the motor generator, and

the predetermined engagement and disengagement criteria are based on at least one of heating and cooling requirements of at least one of the power supply, the power electronics unit and the motor generator, and the motor generator.

24. The system of claim 21, further comprising:

a manifold configured to receive the fluid from the dynamic heat generator outlet and distribute the fluid to the at least one downstream component.

25. The system of claim 24, wherein

The at least one component includes at least one of a power supply portion arranged to supply power to the motor generator, a power electronic unit electrically connected between the power supply portion and the motor generator, and the motor generator.

26. The system of claim 24, wherein

The manifold is arranged to distribute the fluid from a plurality of manifold outlets,

at least one of the plurality of manifold outlets includes a flow control valve controllable by the thermal management controller,

the at least one downstream component is positioned in a fluid distribution branch component of a cabin branch and an engine branch, wherein the manifold is arranged to distribute the received fluid to the cabin branch and the engine branch in response to thermal requirements of a cabin heat exchanger and the engine.

27. The system of claim 21, wherein

The dynamic heat generator is integrated with

A pump driven in conjunction with the dynamic heat generator, the pump configured to receive the fluid upstream of the dynamic heat generator inlet, an

A bypass circuit configured to bypass the dynamic heat generator inlet by carrying the fluid received by the pump downstream of the dynamic heat generator outlet.

28. The system of claim 21, further comprising:

a pump separate from the dynamic heat generator, the pump configured to circulate the fluid to the at least one component downstream of the dynamic heat generator outlet.