DE102014107240A1 - Hybrid hydrostatic drive for a hybrid powertrain - Google Patents

Abstract

The invention relates to a hydrostatic hybrid drive device (H) for a hybrid drive train (A), in particular of a vehicle, wherein the hybrid drive device (H) has a hydrostatic displacement machine (1) which has a drive shaft (2) consisting of a housing (3). the displacement machine (1) is led out and a housing interior of the displacement machine (1) in the region of the drive shaft (2) is sealed by means of a sealing device to the environment. The hybrid drive device (H) according to the invention comprises a high-pressure accumulator device (7) and a low-pressure accumulator device (8), wherein the prestress (PH) of the high-pressure accumulator device (7) is higher than the prestress (PN) of the low-pressure accumulator device (8) and the housing interior of the positive displacement machine (8). 1) communicates with a container (5), wherein the bias voltage (PN) of the low pressure storage device (8) is higher than the pressure level of the container (5).

Description

The invention relates to a hydrostatic hybrid drive device for a hybrid drive train, in particular of a vehicle, wherein the hybrid drive device comprises a hydrostatic displacement machine having a drive shaft, which is led out of a housing of the positive displacement machine and a housing interior of the displacement machine in the region of the drive shaft by means of a sealing device to the environment is sealed.

Vehicles, such as motor vehicles or public transport vehicles, such as buses, preferably for local passenger transport, and mobile self-propelled machines, especially trucks, agricultural machinery, forestry machinery and construction equipment, such as excavators, wheel and telescopic loaders, tractors, combine harvester, forage harvester, sugar beet or potato harvester , Have a drive train with a drive motor, which is usually designed as an internal combustion engine, which drives a consumer, for example, a traction drive of the vehicle.

Increasingly, hybrid powertrain concepts are used in such vehicles. With regard to the construction of the hybrid drive train, embodiments are known as a serial hybrid, as a parallel hybrid or as a power-split hybrid.

Vehicles with a hybrid powertrain are powered by a combination of different energy sources. In addition to the generally designed as an internal combustion engine drive motor as an energy source, the energy source of the hybrid drive device is provided and carried in the vehicle, which in a mechanical hybrid drive device, for example, a flywheel in a hybrid electric drive device of a battery, accumulators or high-performance capacitors or in a hydrostatic hybrid drive device of a hydraulic accumulator may be formed.

Known hybrid drive device have a high overhead and thus a high construction cost.

Known electric hybrid drive devices consist of an electrical energy storage and an electric, operable as a motor and generator machine, which is usually designed as an asynchronous machine and to control a power electronics is required. For the electrical energy storage this is usually also an air conditioning system required to heat or cool the energy storage during operation. Electric hybrid drive devices are very expensive due to the low capacity of the electrical energy storage and the need for operation additional components from the fields of power electronics and air conditioning. In addition, the low power and energy density of the electrical energy storage has a negative effect on the total weight of the vehicle. Another disadvantage of electric hybrid drive devices is that the electrical energy storage represents an increased potential danger, for example, by self-ignition and a threat to a person burning a burning vehicle with a built-in electrical energy storage of a hybrid electric drive device.

Known mechanical hybrid drive devices with a mechanical energy storage, such as a flywheel storage, usually work with very large or very fast rotating flywheels. However, the additional mass of the flywheel accumulator of a mechanical hybrid propulsion device results in a reduction in the energy consumption advantage of the vehicle, since in the driving cycles correspondingly more energy is required for the acceleration of the vehicle.

Known hydrostatic hybrid propulsion devices often require a plurality of valves to store and dispense power in a high pressure accumulator. From the WO 2007/071362 A1 a generic hydrostatic hybrid drive device for a vehicle is known in which the hydrostatic hybrid drive device is designed as a displacement machine, which is connected to one side via a line with a low-pressure accumulator and the second side via a further line with a high-pressure accumulator. The displacement machine is operable as a pump and motor and provided for this purpose to promote pressure medium in both flow directions. The positive displacement machine is designed as an adjusting drive adjustable in the displacement volume. In the WO 2007/071362 A1 arise in pump operation and engine operation different flow directions of the positive displacement machine. In order to thus enable pump and motor operation with the same direction of rotation of the displacement machine, the adjusting drive is designed to be adjustable on both sides and thus via the position with displacement volume zero in both directions, whereby the adjustment of the positive displacement machine and thus the positive displacement machine of the hydrostatic hybrid drive device is correspondingly complex ,

In addition, hydrostatic hybrid drive devices are already known in which the displacement machine, which is connected to a high-pressure accumulator and with a low-pressure accumulator, have the same flow directions of the positive-displacement machine in pump operation and in engine operation. The displacement machine can in this case be designed as a unidirectionally adjustable adjusting drive.

Both in a hydrostatic hybrid drive device with a displacement drive adjustable on both sides as a displacement machine as well as in a hydrostatic hybrid drive device with a unidirectionally adjustable adjusting drive as a displacement machine, it is necessary to bias the adjustment drive on the suction side with pressure to ensure sufficient absorbency. Known hydrostatic hybrid drive devices have for this purpose a prestressed and thus under a bias voltage low-pressure accumulator, which also serves as a tank. In the function of a tank, the low-pressure accumulator is furthermore connected to the housing interior of the displacement machine in order to absorb the leakage of pressure medium occurring during operation of the positive displacement machine. This results in that the housing interior of the displacement machine is raised by the bias of the low-pressure accumulator in the pressure level. The housing interior of the housing of the displacement machine is sealed to the environment in the region of a drive shaft of the displacement machine led out of the housing by means of a sealing device, generally a radial shaft sealing ring. The use of a radial shaft seal is limited in terms of pressure and speed, which limits the performance of the hybrid drive device. In order to be able to raise the housing internal pressure for a correspondingly high absorbency and high performance of the hybrid drive device, a pressure-proof sealing device of the housing interior of the displacement machine to the environment is thus required in the region of the drive shaft which is led out of the housing of the positive displacement machine. However, such pressure-resistant sealing device lead to a high construction cost for the sealing of the housing interior of the displacement machine to the environment in the field of drive shaft.

The present invention has for its object to provide a hydrostatic hybrid drive device available in which the positive displacement machine has a high absorbency and in which the sealing of the housing interior of the positive displacement machine to the environment in the drive shaft has a simple and inexpensive construction.

This object is achieved according to the invention in that the hybrid drive device comprises a high pressure storage device and a low pressure storage device, wherein the bias of the high pressure storage device is higher than the bias of the low pressure storage device, and the housing interior of the positive displacement machine is in communication with a reservoir, the bias of the low pressure storage device being higher than that Pressure level of the container is. The hybrid drive device according to the invention is thus provided with a three-tank system comprising the container, the low pressure storage device and the high pressure storage device. These three containers of the three-tank system each have different pressure levels. The displacement machine delivers pressure medium from the low-pressure storage device to the high-pressure storage device or from the high-pressure storage device to the low-pressure storage device. The bias of the low pressure storage device is lower than the bias of the high pressure storage device. The pressure level of the container having the function of a tank is lower than the bias of the low pressure storage device. As a result, special advantages are achieved because a high absorbency of the positive displacement machine is ensured by a corresponding bias of the low-pressure storage device, which allows high performance of the hybrid drive device. At the same time leads by the connection of the housing interior of the displacement machine with the container, the bias of the low-pressure accumulator device does not increase the internal pressure of the housing. In the invention, rather, the internal pressure of the casing of the displacement machine corresponds to the pressure level of the container, so that a simple and cost-effective sealing of the housing interior of the displacement machine to the environment in the field of drive shaft is made possible.

According to an advantageous embodiment of the invention, the container is designed as a non-preloaded container, which communicates with the environment, or formed as a prestressed container. A non-prestressed container communicates with the environment and thus the atmosphere, forming a pressureless tank. The housing internal pressure of the housing of the displacement machine thus corresponds to the pressure of the environment, so that a simple and cost-effective sealing of the housing interior of the displacement machine to the environment in the region of the drive shaft is made possible. Alternatively, the container may be under a slight bias, which is lower than the bias of the low-pressure storage device, so that also a simple and cost-effective sealing of the housing interior of the displacement machine to the environment in the drive shaft is made possible. Such a biased to a low bias container can be biased for example with compressed air from a compressed air source to a low pressure level.

The high-pressure storage device is formed according to a preferred embodiment of the invention as a prestressed pressure accumulator, in particular bladder accumulator, piston accumulator or diaphragm accumulator. Preferably, the high pressure storage device is under a gas bias.

The low-pressure storage device is formed according to an embodiment of the invention as a prestressed accumulator, in particular prestressed container, for example by compressed air source, bladder accumulator, piston accumulator or diaphragm accumulator. Preferably, the low-pressure storage device is under a gas bias.

With regard to a simple construction and a compact construction of the hybrid drive device according to the invention, there are particular advantages if, according to one embodiment of the invention, the high-pressure storage device and the low-pressure storage device are designed as double piston accumulators. With a double piston accumulator, the function of the high-pressure accumulator device and the low-pressure accumulator device can be achieved with a particularly small space requirement.

With regard to a simple and inexpensive construction of the hybrid drive devices, there are advantages if the displacement machine is operated in an open circuit and in the same direction of rotation and the same flow direction of a pressure medium as a pump and motor is operable, wherein an outlet side of the displacement machine a delivery line is connected to the outlet Pumping operation of the displacement machine is connected to the high-pressure storage device and in the engine operation of the displacement machine with the low-pressure storage device, and wherein connected to an inlet-side suction side of the displacement machine, a suction line which is connected in the pump operation of the displacement machine with the low pressure storage device and in the engine operation of the positive displacement machine with the high pressure storage device For controlling the pump and motor operation of the displacement machine, a valve device is provided. The hydrostatic hybrid drive device according to the invention consists of a hydrostatic displacement machine operated in an open circuit, which can be operated as pump and motor with the same direction of rotation and the same flow direction of a pressure medium. The displacement machine is connected to an outlet-side delivery side with a delivery line in connection with the driven by the drive train displacement machine promotes pumping fluid pressure medium in the high pressure storage device. In this case, the high-pressure storage device represents the sole consumer of the displacement machine, so that in the case of the hybrid drive device according to the invention, the displacement machine promotes exclusively into the high-pressure storage device during the energy recovery. During pump operation during energy recovery, the displacement machine is supplied with pressure medium on the suction side from the low-pressure storage device, and the displacement machine conveys on the delivery side into the high-pressure storage device. During engine operation, the displacement machine is driven on the suction side by the pressure medium from the high-pressure storage device and conveys the pressure medium supplied at the suction side via the delivery side into the low-pressure storage device. During engine operation, the displacement machine thus outputs a torque to the drive train. Such an open-circuit operated displacement machine, which conveys pressure medium between the low pressure storage device and the high pressure storage device back and forth, has a simple and inexpensive construction. In the hybrid drive device of the present invention, since the high-pressure accumulator device constitutes the sole load of the positive displacement machine, a compact structure of the hybrid drive device can be achieved.

Since in the hybrid drive device according to the invention in pump operation and in engine operation, the system-related leaks of the displacement machine flow into the container, the Leckagedruckmittelmege is no longer available in the low-pressure storage device and the high-pressure storage device for energy recovery. In order to compensate for the leaking to the container and missing in the storage devices pressure medium quantity again and fill, according to an advantageous embodiment of the invention, a charging device is provided which allows loading of the low-pressure storage device by a pump operation of the displacement machine with pressure medium from the container.

According to an advantageous embodiment of the invention, the suction line of the positive displacement machine communicates with the container, wherein at least one discharge line of the high-pressure accumulator device and the low-pressure accumulator device is connected to the intake line, wherein the charging device has a shut-off valve which is located in the intake line between the connection of the at least one discharge line and the container is arranged and designed as a blocking in the direction of the container check valve. In the guided from the container to the suction side of the displacement machine suction a blocking in the direction of the container check valve is arranged. In the loading mode can thus be used as a pump operated displacement machine suck in pressure medium via the opening check valve from the container. At least one discharge line provided for discharging the high-pressure storage device and the low-pressure storage device is connected to the suction pipe between the suction side of the positive displacement machine and the shut-off valve. In engine operation of the displacement machine, wherein the displacement machine is supplied to the suction side, the pressurized pressure medium from the high-pressure accumulator device, thus preventing the arranged in the suction valve in a simple manner, a discharge of the pressure medium from the high pressure storage device into the container. During pump operation, the displacement machine is supplied with pressure medium on the suction side from the low-pressure storage device on the suction side. Due to the bias of the low pressure storage device over the pressure level of the container, the check valve is biased to ensure suction of pressure medium from the low pressure storage device during pump recovery during energy recovery to ensure high suction capability of the positive displacement machine during pumping operation of the high pressure storage device ,

According to an advantageous embodiment of the invention, the charging device comprises a charging line, which is led from the delivery line of the displacement machine to the low-pressure storage device, and a charging valve arranged in the charging line. With such a charging line can be achieved in a simple manner that the sucked on the open check valve from the container pressure medium can be promoted by the positive displacement machine in the low-pressure storage device to compensate for the leakage.

With regard to a simple construction, there are advantages when the charging valve has a blocking position and a flow position. During pump and motor operation of the displacement machine for energy recovery, the charging valve is in the blocking position. For charging and charging the low-pressure storage device, the charging valve is opened in a flow position.

According to an advantageous embodiment of the invention, the charging valve is designed as a switching valve, whereby a simple and inexpensive construction of the charging valve is achieved.

According to one embodiment of the invention, a blocking in the direction of the displacement machine shut-off valve is arranged in the delivery line. Such a check valve in the delivery line prevents in a simple way the return of pressure medium from the high pressure storage device to the delivery side of the positive displacement machine. With such a check valve, the charging operation of the high-pressure accumulator device can be carried out in a circuitically simple manner and, with the high-pressure accumulator device charged, an outflow of the pressure medium from the high-pressure accumulator device to the delivery side of the positive displacement machine can be prevented.

According to an advantageous embodiment of the invention, the valve device for controlling the pump and motor operation of the displacement machine has a first valve device which is connected to the delivery line of the positive displacement machine, to a connection line led to the high-pressure storage device, to a discharge line of the high-pressure storage device guided to the suction line and to a discharge line connected to the low pressure storage device connecting line is connected. With such a first valve device can be easily controlled the connection of the delivery line of the displacement machine with the high pressure storage device and the low pressure storage device and the connection of the discharge line of the high pressure storage device with the suction line of the displacement machine for the pump and motor operation of the positive displacement machine.

The first valve means expediently has a pump operating position in which the delivery line of the positive displacement machine is connected to the connection line led to the high pressure storage device and the discharge line of the high pressure storage device and the connection line led to the low pressure storage device are shut off, and an engine operating position in which the high pressure storage device guided connecting line is connected to the discharge line of the high pressure storage device and the delivery line of the positive displacement machine is connected to the guided to the low pressure storage device connecting line. In this way, can be achieved with the first valve device in a simple manner that promotes the positive displacement pump in pressure pumping means for loading the high-pressure accumulator device in the high-pressure accumulator device and promotes the engine supplied from the high-pressure accumulator device on the suction side pressure medium in the low-pressure accumulator device.

The valve device for controlling the pump and motor operation of the displacement machine, according to an advantageous embodiment of the invention, a second valve means which is arranged in a guided to the suction discharge line of the low pressure storage device. With such a second valve device can easily connect the Discharge line of the low-pressure accumulator device are controlled with the suction line of the positive displacement machine for the pump and motor operation of the positive displacement machine.

The second valve means expediently has a pump operating position in which the discharge line of the low-pressure storage device is opened, and an engine operating position in which the discharge line of the low-pressure storage device is shut off. As a result, can be achieved with the second valve device in a simple manner that the displacement machine is supplied in pump operation on the suction side of pressure medium from the low pressure storage device.

With regard to a simple construction, there are advantages if, according to one embodiment of the invention, the second valve device is designed as a switching valve.

According to an advantageous embodiment of the invention, the valve device for controlling the pump and motor operation of the displacement machine has a control valve device which is connected to the delivery line of the positive displacement machine, to a connection line led to the high-pressure storage device and to a common discharge line of the high-pressure storage device and the low-pressure storage device guided to the suction line and connected to a guided to the low-pressure storage device connection line. With such a control valve device, which is connected to a common discharge line, by means of both the connection of the high pressure storage device and the connection of the low pressure storage device with the suction line of the positive displacement machine can be controlled in a simple way with only one valve, the connection of the delivery line of the displacement machine the high-pressure storage device and the low-pressure storage device and the connection of the high-pressure accumulator device and the low-pressure accumulator device are controlled by means of the common discharge line to the suction line of the displacement machine for the pump and motor operation of the positive displacement machine.

The control valve means expediently has a pump operating position, in which the delivery line of the positive displacement machine is connected to the connection line led to the high pressure storage device and the common discharge line is connected to the connection line led to the low pressure storage device, and an engine operating position in which the connection line led to the high pressure storage device the common discharge line is connected and the delivery line of the positive displacement machine is connected to the guided to the low pressure storage device connecting line. This can be achieved with the control valve device in a simple manner that the displacement machine is supplied in the pump operation by means of the common discharge line on the suction side pressure medium from the low pressure storage device and the displacement machine promotes the pressure medium for loading the high pressure storage device in the high pressure storage device and in the engine operation by means of the high pressure storage device the common discharge line on the suction side supplied pressure medium in the low pressure storage device promotes.

With regard to a simple construction, there are advantages if, according to one embodiment of the invention, the first valve device or the control valve device is designed as a switching valve.

If the drive devices according to the invention are used in a vehicle for generating energy during braking operation of the vehicle, there are particular advantages if, according to a development of the invention, a brake torque generating device is provided which generates a braking torque applied to the positive displacement machine during pump operation of the displacement machine. If the currently in the high-pressure accumulator device pending accumulator boost pressure is not sufficient to build a sufficient braking torque during braking operation of the vehicle by the pump operation of the positive displacement machine, can be set with a brake torque generating device in a simple manner, a desired braking performance.

According to an advantageous embodiment of the invention, the brake torque generating device has a retarder valve which is arranged in the connecting line guided to the high-pressure storage device. With a guided in the high pressure storage device connecting line and thus arranged in the inlet of the high-pressure accumulator retarder valve can be easily raised at the discharge side of the displacement machine at an insufficient accumulator charging pressure of the high-pressure accumulator device, the pressure and set a pressure on the delivery side of the positive displacement machine according to the desired braking performance become.

According to an alternative embodiment of the invention, the brake torque generating device is formed by an additional control position of the first valve device or the control valve device, in which the connection of the delivery line of the positive displacement machine with the High-pressure storage device guided connection line can be throttled. With an additional control position of the first valve device, wherein the additional control position throttles the connection of the delivery line of the displacement machine with the guided to the high pressure storage device connecting line, can be easily raised at the delivery side of the positive displacement machine at insufficient storage boost pressure of the high pressure storage device, the pressure and a pressure be set on the delivery side of the displacement machine according to the desired braking power.

The first valve device or the control valve device is designed for this purpose according to an advantageous embodiment of the invention as throttling in intermediate positions directional control valve. With a directional control valve throttling in intermediate positions, for example a proportional directional control valve, it is possible in a simple manner to set the pressure on the delivery side of the displacement machine according to the desired braking power.

According to an advantageous embodiment of the invention, the valve device and the charging valve are electrically actuated and are for actuation with an electronic control device in communication, the input side with a memory pressure of the high-pressure accumulator device sensing sensor device and a memory pressure of the low-pressure accumulator device sensing sensor device is in communication. This results in a simple control effort, since with an electronic control device and one of this electrically actuated valve device in response to the sensed by the sensor device accumulator pressure of the high-pressure accumulator device by appropriate control of the valve means of the pump operation of the displacement machine for loading the high-pressure accumulator device can be initiated and at a corresponding in the high-pressure accumulator device pending accumulator charging pressure by appropriate control of the valve means of the engine operation of the displacement machine can be initiated to deliver a torque to the drive train. In addition, on the basis of the sensor devices, a too low charge pressure of the two storage devices can be detected in a simple manner and the low-pressure storage device can be charged with pressure medium from the container by means of the electrically actuated charge valve with an electronic control device.

Operating strategies are advantageously stored in the electronic control device in order to charge the high-pressure storage device with excess energy of a drive motor as a function of operating conditions of the vehicle and / or during braking operation of the consumer by a pump operation of the displacement machine. This makes it possible to charge the high-pressure accumulator device in certain operating states in which excess energy is generated at the drive motor and / or charge it in a braking operation of the consumer with the resulting braking energy in order to enable energy recovery. The electronic control device is for this purpose in communication with corresponding actuators, by means of which the respective operating state and / or the braking operation of the consumer can be determined, for example, an accelerator pedal device or a brake pedal in the execution of the consumer as a drive of the vehicle.

In the case of the hybrid drive device according to the invention, the displacement machine can, during engine operation, serve as a booster drive of the running drive motor and / or as a hydraulic starter of the parked drive motor. The hybrid drive device according to the invention can thus be used to support the current drive motor and / or as a hydraulic starter in the context of a start-stop function of the drive motor, which can be achieved due to the robust design and function of the positive displacement machine, a cost-effective start-stop function of the drive motor ,

Furthermore, a charging strategy is stored in the electronic control device in order to charge the low-pressure storage device as a function of the states of the low-pressure storage device and the high-pressure storage device detected by the sensor devices by a pump operation of the displacement machine.

According to an advantageous embodiment of the invention, the high pressure storage device is associated with a pressure relief valve. In pump operation of the displacement machine in which the high-pressure accumulator device is charged with pressure medium, the charging operation can be secured in a simple manner via a pressure limiting valve and the accumulator pressure pending in the high-pressure accumulator device can be secured.

Advantageously, the pressure relief valve secures the high pressure storage device to the low pressure storage device. Pressure medium flowing out of the high-pressure accumulator device via the pressure limiting valve thus remains present in the low-pressure accumulator device and thus does not have to be supplemented by a loading operation from the container.

Conveniently, the low-pressure storage device is associated with a pressure relief valve. With such a pressure relief valve can be secured in a simple manner pending in the low-pressure storage device accumulator pressure.

The pressure limiting valve preferably secures the low-pressure storage device to the container.

Particular advantages can be achieved if, according to a development of the invention, the high-pressure storage device can be relieved by means of a relief valve to the container or the low-pressure storage device and / or the low-pressure storage device can be relieved by means of a relief valve to the container. With such relief valves, the high-pressure storage device and the low-pressure storage device can be relieved to the container in a simple manner for service and maintenance.

According to one embodiment of the invention, the drive shaft of the positive displacement machine is associated with a coupling device. With such a coupling device, the drive connection of the displacement machine to the drive train can be produced or separated in a simple manner. The coupling device makes it possible in a simple manner to connect the displacement machine to the drive train only for the charging operation of the low-pressure storage device and during energy recovery by pump and motor operation and to separate it from the drive train in other operating states, for example during prolonged stationary driving situation of the vehicle to avoid a permanent and lossy operation of the displacement machine.

The displacement machine can be designed as constant-displacement engine in the displacement volume.

Alternatively, the displacement machine can be configured as an adjustment drive that can be adjusted on one side in the displacement volume, wherein a displacement volume adjustment device of the adjustment drive can be adjusted starting from a position with a minimum displacement volume in a direction of adjustment. Due to the constant flow direction of the pressure medium of the displacement machine in pump operation and engine operation arise in a trained as Verstelltriebwerk displacement machine particular advantages in terms of a simple and inexpensive construction of the displacement machine, since the displacement machine can be configured as unidirectionally adjustable adjusting drive, in which a displacement volume adjusting device of the adjustment starting from a position with a minimum displacer volume, for example a minimum delivery volume defined by a stop, in a single adjustment direction is adjustable. Such a unidirectionally adjustable adjusting mechanism has a significantly simplified construction of the adjustment of the displacer volume adjusting device compared with a reciprocally adjustable adjusting mechanism, so that a cost-effective and compact design of the displacer machine results.

The displacer volume adjusting device is adjustable according to an advantageous embodiment of the invention by means of a hydraulic adjusting device, wherein the adjusting device for supplying pressure medium with the low-pressure accumulator device and / or the high-pressure accumulator device is in communication and wherein the adjusting device is in communication with the container. The adjustment of the displacer volume of the displacement machine thus takes place with pressure medium and thus with energy from the low-pressure storage device and / or the high-pressure storage device, wherein the amount of pressure medium required for adjusting the displacer volume adjusting device is taken from the low-pressure storage device and / or the high-pressure storage device. After adjusting the displacement machine, the pressure medium is released into the container. In connection with the charging device, the pressure medium quantity removed for the adjustment of the displacer volume of the displacers from the low-pressure storage device and / or the high-pressure storage device and subsequently discharged to the container can be easily replenished in the low-pressure storage device.

The displacer volume adjusting device of the adjusting engine is advantageously connected to the control with the electronic control device in connection. The torque of the displacement machine can thus be controlled by the electronic control device by appropriately adjusting the displacement volume adjusting device and thus the displacement volume of the adjusting, which is received in the pumping operation of the displacement machine in connection with the memory pressure in the high-pressure accumulator device or discharged by the displacement machine during engine operation.

The invention further relates to a vehicle having a drive train driven by a drive motor and a hydrostatic hybrid drive device according to the invention, wherein the drive train is designed as a parallel hybrid and has at least one consumer. With the hydrostatic hybrid drive device according to the invention can be created in a vehicle in a simple and cost-effective manner and with a low space requirement for the hybrid drive device, a parallel hybrid in which the Displacement machine and the drive motor act on the drive train.

The consumer may be formed as a driven by a transmission slewing. With a hybrid drive device according to the invention, in a vehicle with a slewing gear, for example a working machine designed as an excavator, an energy recovery can take place during braking operation of the slewing gear and support of the drive motor during acceleration of the slewing gear can be achieved.

The consumer may be formed as a driven by a transmission drive axle with at least two driven drive wheels. With a hybrid drive device according to the invention, in a vehicle having a traction drive comprising a drive axle, for example a motor vehicle or a bus, an energy recovery can take place during braking operation of the vehicle and assistance of the drive motor during acceleration and / or driving of the vehicle can be achieved.

Due to the compact dimensions and compact design of the hybrid drive device according to the invention, the hybrid drive device can be arranged in the drive train in direct drive. The displacement machine of the hybrid drive device is thus installed directly in the drive train and integrated and allows a drive through.

Alternatively, the hybrid drive device via a displacement gear, in particular a spur gear, be connected to the drive train. The displacement machine of the hybrid drive device is thus connected via a displacement gear to the drive train and integrated in this.

Such a connection of the hybrid drive device with the drive train of the vehicle via a displacement gearbox offers the possibility to connect the hybrid drive device according to an embodiment of the invention by means of a coupling device to the drive train and to separate from the drive train. The positive displacement machine of the hybrid drive device can be temporarily separated from the drive train in the open position of the clutch device, whereby a permanent and loss-making operation of the displacement machine can be avoided in certain operating conditions, for example during prolonged stationary driving situation of the vehicle.

Due to the compact dimensions and compact design of the hybrid drive device according to the invention, the hybrid drive device can be installed at any point of the drive train.

According to one embodiment of the invention, the hybrid drive device is arranged in the drive train between the drive motor and a transmission driving the consumer.

With particular advantage, in this case a coupling device is arranged in the drive train in the power flow between the hybrid drive device and the transmission. When the clutch device is opened, the hybrid drive device according to the invention can easily be used to start the parked drive motor as part of a start-stop function.

With particular advantage, a coupling device is arranged in the drive train in the power flow between the drive motor and the hybrid drive device. If this coupling device is open and a coupling device which is closed in the power flow between the hybrid drive device and the transmission, can be driven by the hybrid drive device of the consumer when the engine is switched off.

According to an alternative embodiment of the invention, the hybrid drive device is arranged in the drive train between the transmission and the consumer.

With particular advantage, a clutch device is arranged in the drive train in the power flow between the transmission and the hybrid drive device. When the clutch device is open, the consumer can be driven when the prime mover is switched off via the hybrid drive device.

According to an alternative embodiment of the invention, the hybrid drive device is drivingly connected to an additional axle of the vehicle. If the vehicle has, in addition to the drive axle driven via the transmission, an additional axle which is connected to the hybrid drive device, an energy recovery can take place in the braking mode of the vehicle and an additional torque can be applied by the hybrid drive device while the vehicle is driving.

With particular advantage, a coupling device is arranged in the force flow between the hybrid drive device and the additional axle. With such a coupling device, the displacement machine of the hybrid drive device in a simple manner from the additional axis be separated. The positive displacement machine of the hybrid drive device can be temporarily separated from the additional axle in the open position of the clutch device, whereby a permanent and loss-making operation of the displacement machine can be avoided in certain operating conditions, for example during prolonged stationary driving situation of the vehicle.

By connecting the displacement machine of the hybrid drive device with a power take-off of the drive motor can also be created via the positive displacement machine as a booster drive to support the current drive motor and / or a hydraulic starter to start the parked drive motor as part of a start-stop function. In this case, a coupling device may also be provided with which the positive-displacement machine can be separated from the power take-off in order to avoid losses due to the continuous operation of the positive-displacement machine.

Further advantages and details of the invention will be explained in more detail with reference to the embodiments illustrated in the schematic figures. This shows

1 1 the circuit diagram of a first embodiment of a hydrostatic hybrid drive device according to the invention,

2 5 is the circuit diagram of a second embodiment of a hydrostatic hybrid drive device according to the invention,

3 the circuit diagram of a third embodiment of a hydrostatic hybrid drive device according to the invention,

4a to 4e various embodiments of a vehicle with a drive train according to the invention comprising a hybrid drive device and

5 a flowchart of the operating modes of the hydrostatic hybrid propulsion device according to the invention.

In the 1 to 3 Various embodiments of a hydrostatic hybrid drive device H according to the invention are shown. In the 1 to 3 are the same components provided with the same reference numerals.

The hybrid drive device H according to the invention consists of a hydrostatic displacement machine 1 , which is operated in the open circuit and is operable in the same direction of rotation and the same flow direction of a pressure medium as a pump and motor. In the hybrid drive device H according to the invention, the displacement machine 1 designed as a simple two-quadrant engine, which is operable at the same direction of rotation and the same flow direction of the pressure medium as the pump and motor.

The displacement machine 1 has a drive shaft 2 , about the pumping operation of the displacement machine 1 a torque from one in the 1 and 2 not shown drive train of a vehicle for driving the positive displacement machine 1 can be applied or on the motor in the displacement machine 1 from the displacement machine 1 a torque can be introduced into a drive train. The driving connection of the drive shaft 2 with the drive train can be controlled with a coupling device K to the positive displacement machine 1 to connect to the drive train or separate from the drive train. The shoot shaft 2 is from a housing 3 the displacer machine 1 led out. A housing interior of the housing 3 the displacer machine 1 is in the range of the drive shaft 2 sealed to the environment by means of a sealing device, not shown.

The housing interior of the housing 3 the displacer machine 1 is by means of a leakage line 4 with a container 5 the hybrid drive H in combination. In the operation of the positive displacement machine 1 inside the case 3 the displacer machine 1 resulting leakage oil can thus in the container 5 be dissipated.

The displacement machine 1 has an outlet-side delivery side F, to which a delivery line 6 connected in pump operation with a high pressure storage device 7 the hybrid drive device H and in engine operation with a low pressure storage device 8th the hybrid drive unit H is connectable. In the promotion line 6 is a towards the displacer machine 1 blocking check valve 9 arranged. The check valve 9 is formed in the illustrated embodiment as a check valve.

To an intake-side suction side S of the displacement machine 1 is a suction line 10 connected in the pump operation of the positive displacement machine 1 with the low-pressure storage device 8th and during engine operation of the positive displacement machine 1 with the high pressure storage device 7 is connectable.

To the intake pipe 10 is in the 1 and 2 a discharge line 11 the high pressure storage device 7 and a discharge line 12 the low-pressure storage device 8th connected. In the 3 is for the high pressure storage device 7 and for the low pressure storage device 8th a common discharge line 110 provided to the suction line 10 connected.

The suction line 10 still stands with the container 5 in connection. In the intake pipe 10 is between the container 5 and the terminals of the discharge lines 11 . 12 of the 1 and 2 or between the container 5 and the connection of the common discharge line 11 of the 3 one towards the container 5 blocking check valve 13 arranged. The check valve 13 is formed in the illustrated embodiment as a check valve.

In the hybrid drive device H according to the invention, the high-pressure storage device 7 a maximum bias voltage P _H and the low-pressure storage device 8th a maximum bias voltage P _N on. The maximum bias voltage P _{H of} the high pressure storage device 7 is higher than the maximum bias voltage P _{N of} the low-pressure storage device 8th ,

In the 1 to 3 is the high pressure storage device 7 as preloaded accumulator 7a , in particular bladder accumulator, piston accumulator or

Diaphragm store, trained. The accumulator 7a is under a bias, such as a gas bias.

The low pressure storage device 8th of the 1 to 3 is also as a prestressed accumulator 8a , in particular bladder accumulator, piston accumulator or diaphragm accumulator, formed. The accumulator 7a is under a bias, such as a gas bias or a pneumatic bias.

The container 5 the hybrid drive device H of the invention 1 to 3 may be designed as a non-biased container and thus as a non-pressurized tank, which is in communication with the environment and thus with the atmosphere, or designed as a prestressed container, which is biased to a low pressure level of a few bar (maximum 3bar). The bias voltage P _{N of} the low-pressure storage device 8th is higher than the pressure level of the container 5 ,

For controlling the pump and motor operation of the positive displacement machine 1 is a valve device 15 intended.

The valve device 15 of the 1 and 2 is from a first valve device 16 and a second valve device 22 educated.

The first valve device 16 is in the in the 1 illustrated embodiment designed as a four-port two-position valve. The first valve device 16 is to the support line 6 the displacer machine 1 to one of the high pressure storage device 7 guided connection line 17 , to the discharge line 11 the high pressure storage device 7 and to one to the low pressure storage device 8th guided connection line 18 connected. The first valve device 16 indicates a pump operating position 16a on, in which the support line 6 the displacer machine 1 with the to the high pressure storage device 7 guided connection line 17 is connected, so that by a pump operation of the displacement machine 1 the high pressure storage device 7 can be loaded with pressure medium. In the pump operating position 16a continue to be the discharge line 11 the high pressure storage device 7 and to the low pressure storage device 8th guided connection line 18 shut off. The first valve device 16 also has an engine operating position 16b in which the to the high pressure storage device 7 guided connection line 17 with the discharge line 11 the high pressure storage device 7 connected and the support line 6 the displacer machine 1 with the to the low pressure storage device 8th guided connection line 18 connected is. During engine operation, the displacement machine thus becomes 1 from the suction side S from the high pressure storage device 7 driven pressure medium driven.

In the in the 1 illustrated embodiment, the first valve device 16 designed as a switching valve. The first switching valve 16 is in the illustrated embodiment by means of a spring 20 in the direction of the pump operating position 16a acted upon and by means of an actuating device 21 towards the engine operating position 16b acted upon. In the illustrated embodiment, the first switching valve 16 electrically actuated, wherein the actuating device 21 as electrical actuating device M2, for example magnet, is formed.

The valve device 15 of the 1 and 2 has a second valve device 22 on that in the discharge line 12 the low-pressure storage device 8th is arranged. The second valve device 22 is in the in the 1 and 2 illustrated embodiments designed as a two-port two-position valve. The second valve device 22 indicates a pump operating position 22a on, in which the discharge line 12 the low-pressure storage device 8th is open, and an engine operating position 22b on, in the unloading line 12 the low-pressure storage device 8th is locked.

In the in the 1 and 2 illustrated embodiments, the second valve device 22 designed as a switching valve. The second switching valve 22 is in the illustrated Embodiments by means of a spring 23 towards the engine operating position 22b acted upon and by means of an actuating device 24 in the direction of the pump operating position 22a acted upon. In the illustrated embodiment, the second switching valve 22 electrically actuated, wherein the actuating device 24 as electrical actuating device M1, for example magnet, is formed.

In the embodiment of 3 is the valve device 15 from a single control valve device 116 formed to the conveyor line 6 the displacer machine 1 to which the high pressure storage device 7 guided connection line 17 and to the to the suction line 10 Guided shared discharge line 110 the high pressure storage device 7 and the low pressure storage device 8th and to the low pressure storage device 8th guided connection line 18 connected.

The control valve device 116 indicates a pump operating position 116a on, in which the support line 6 the displacer machine 1 with the to the high pressure storage device 7 guided connection line 17 is connected and the common discharge line 110 with the connection line leading to the low-pressure storage device 18 connected is. The control valve device 116 also has an engine operating position 116b in which the to the high pressure storage device 7 guided connection line 17 with the common discharge line 110 connected and the support line 6 the displacer machine 1 with the to the low pressure storage device 8th guided connection line 18 connected is. The control valve device 116 is electrically actuated in the illustrated embodiment and by means of an actuating device 21 towards the engine operating position 116b and by means of an actuating device 24 in the direction of the pump operating position 116a acted upon. The actuating device 21 is formed in the illustrated embodiment as an electrical actuator M2, such as magnet. In the illustrated embodiment, the actuating device 24 as an electrical actuator M1, for example, magnet formed.

The hybrid drive unit H of the invention 1 to 3 is with a charging device 30 provided a loading of the low-pressure storage device 8th by a pump operation of the positive displacement machine 1 with pressure medium from the container 5 allows. This is the suction line 10 the displacer machine 1 over the shut-off valve 13 with the container 5 to charge the low-pressure storage device 8th in pump operation of the displacement machine 1 on the suction side S pressure fluid from the container 5 to be able to suck. The charging device 30 also has a charging line 31 on, by the support line 6 the displacer machine 1 to the low pressure storage device 8th is guided. In the charging line 31 is a loading valve 32 arranged, which is a blocking position 32a and a flow position 32b having.

In the in the 1 to 3 illustrated embodiments is the charging valve 32 designed as a switching valve. The loading valve 32 is in the illustrated embodiments by means of a spring 33 in the direction of the blocking position 32a acted upon and by means of an actuating device 34 in the direction of the flow position 32b acted upon. In the illustrated embodiments, the loading valve 32 electrically actuated, wherein the actuating device 34 as electrical actuating device M0, for example magnet, is formed.

The valve devices 16 . 22 or the control valve device 116 and the loading valve 32 are electrically actuated in the illustrated embodiments and are for actuation with an electronic control device 35 in connection. The electronic control device 35 is the input side with a memory pressure of the high pressure storage device 7 detecting sensor device 36 and one of the accumulator pressure of the low pressure accumulator device 8th detecting sensor device 37 in connection.

The high pressure storage device 7 is a pressure relief valve 41 assigned. In the illustrated embodiment, the pressure relief valve secures 41 the high pressure storage device 7 to the low pressure storage device 8th from. The pressure relief valve 41 can do this in a connection line 42 be arranged by the charging line 31 passing through the support line 6 and in the pump operating position 16a located valve device 16 or in the pump operating position 116a located control valve device 116 with the connection line 17 in connection with that with the low-pressure storage device 8th related connection line 18 is guided.

Furthermore, the low pressure storage device 8th a pressure relief valve 43 assigned. In the illustrated embodiment, the pressure relief valve secures 43 the low pressure storage device 8th to the container 5 from. The pressure relief valve 43 can do this in a connection line 44 be arranged by a line 45 associated with the low pressure storage device 8th communicates with the container 5 is guided. In the illustrated embodiment, the connection line 44 to the intake pipe 10 connected, the connection of the connecting line 44 to the intake pipe 10 between the container 5 and the check valve 13 is arranged.

Furthermore, the high pressure storage device 7 by means of a relief valve 50 to the low pressure storage device 8th relieved and the low-pressure storage device 8th by means of a relief valve 51 to the container 5 relieved.

In the 1 to 3 is the displacement machine 1 designed as adjustable in the displacement volume adjusting drive. The displacement machine 1 is unilaterally adjustable, wherein a displacement volume adjusting device 1a the displacer machine 1 , For example, an inclination adjustable swash plate in the execution of the displacement machine 1 as axial piston machine in swash plate construction, starting from a position with minimum displacement volume, in a direction of adjustment in the direction of a maximum displacement volume is adjustable. The position with minimum displacement volume is from a stop 1b defined, in which the displacement machine 1 delivers a defined minimum flow during pump operation.

The displacer volume adjuster 1a is by means of a hydraulic actuator 1d adjustable. The adjusting device 1d is in the embodiment of 1 for supplying pressure medium with the low-pressure storage device 8th in connection. The adjusting device 1d can this input side to the line 45 associated with the low pressure storage device 8th communicates, be connected. On the output side is the adjusting device 1d via a drain line 60 with the container 5 in connection.

The displacement machine 1 is electro-hydraulic, in particular electro-proportional, controllable in the displacer volume. For this purpose, the hydraulic adjusting device 1d the displacer machine 1 in a manner not shown electrically actuated and is for driving with the electronic control device 35 communicates.

With the hybrid drive device H according to the invention, an energy recovery by a pump operation of the displacement machine is preferably carried out in a vehicle during braking operation of a consumer 1 in which the high pressure storage device 7 is charged. The of the pump operated in the displacement machine 1 The torque to be absorbed can be determined by the displacement volume of the variable displacement displacer displacer 1 and that currently in the high pressure storage device 7 Pending storage boost P _H be set arbitrarily.

In an operating state in which the current accumulator charging pressure P _{H of} the high-pressure accumulator device 7 is insufficient to build up a sufficient braking torque, the hybrid drive device according to the invention H with a brake torque generating device 65 provided in the pump operation of the displacement machine 1 one at the displacement machine 1 pending braking torque generated.

In the 1 is the brake torque generating device 65 formed by a retarder valve R, which in the inlet of the high-pressure accumulator device 7 is arranged. In the 1 this is the retarder valve R in the to the high pressure storage device 7 guided connection line 17 arranged. The retarder valve R is formed in the illustrated embodiment as electrically adjustable in the set pressure pressure valve, which is for driving with the electronic control device 35 communicates. The retarder valve R allows the pressure in the inlet of the high pressure storage device 7 adjust according to the desired braking power. To a lossless discharge operation of the high pressure storage device 7 is to be achieved in a bypass line bypassing the retarder valve R. 66 a bypass valve 67 arranged. The bypass valve 67 is in the illustrated embodiment as in the flow direction of the high pressure storage device 7 to the first valve device 16 opening check valve, such as spring-loaded check valve formed.

The 2 is different from the 1 with regard to the execution of the first valve device 16 and the brake torque generating device 65 ,

The 3 is different from the 1 in terms of the execution of the valve device 15 and the brake torque generating device 65 ,

In the 2 is the first valve device 16 designed as a four-port three-position valve, in addition to the pump operating position 16a and the engine operating position 16b an additional control position 16c in which the connection of the delivery line 6 the displacer machine 1 with the to the high pressure storage device 7 guided connection line 17 can be throttled.

In the 3 is the control valve device 116 designed as a four-port three-position valve, in addition to the pump operating position 116a and the engine operating position 116b an additional control position 116c in which the connection of the delivery line 6 the displacer machine 1 with the to the high pressure storage device 7 guided connection line 17 can be throttled.

The brake torque generating device 65 is thus of the additional control position 16c the first valve device 16 or the additional one control position 116c the control valve device 116 educated. In the illustrated embodiment, the additional control position 16c respectively. 116c designed as a neutral position, in which the valve device 16 or the control valve device 116 of feathers 20 is charged. In the 2 is the actuator 21 is formed by two electrical actuators M2, such as magnets.

The valve device 16 of the 2 or the control valve device 116 of the 3 is configured as a directional valve throttling in intermediate positions, for example a proportional valve.

It is understood that in the 3 alternatively the control valve device 116 only with the pump operating position 116a and the engine operating position 116b may be provided and may be formed, for example, as a switching valve when the brake torque generating device 65 analogous to the 1 from a retarder valve R in the to the high pressure storage device 7 guided connection line 17 is trained.

The 2 and 3 differ from the 1 continue with respect to the supply of the actuator 1d the displacer machine 1 with pressure medium.

In the 2 and 3 is the adjusting device 1d the displacer machine 1 for supplying pressure medium to the high pressure storage device 7 connected. The adjusting device 1d is on the input side to a line 70 connected to the high pressure storage device 7 communicates. In the line 70 is to reduce the in the high pressure storage device 7 Pending pressure levels on the pressure level of the actuator 1d the displacer machine 1 a pressure reducing valve 71 arranged.

In the in the 2 and the 3 illustrated embodiments is the adjusting device 1d the displacer machine 1 for supplying pressure medium in addition to the low-pressure storage device 8th in connection. The administration 70 is to the line 45 connected, being upstream of the connection of the line 70 to the line 45 one towards the low pressure storage device 8th blocking check valve 72 , For example, a check valve, in the line 45 is arranged.

In order in the hybrid drive unit H of the 1 to 3 Protecting pressure medium from contamination by particles is the suction line 10 a filter 75 and the actuator 1d the displacer machine 1 a filter 76 assigned.

The displacement machine 1 the hybrid drive H of the 1 to 3 is by means of the drive shaft 2 drivably connected to a drivetrain not shown in detail or drivably connected to form a hybrid drivetrain in the form of a parallel hybrid.

In normal operation without energy recovery by the hybrid drive H, for example, a normal driving operation of the vehicle, the function of the hybrid drive H by a sufficient state of charge of the low-pressure storage device 8th is secured with pressure medium, the coupling device K is open, so that the displacement machine 1 is drivingly separated from the drive train. The mechanical losses of the positive displacement machine 1 thus did not reduce the overall efficiency of the drive train. Conveniently, the valve means 16 . 22 . 116 and the loading valve 32 not driven and are in the in the 1 to 3 represented positions. The displacement machine 1 is suitably set to the minimum displacer volume. In the electronic control device 35 For this purpose, a normal operating mode is stored.

For initializing the hybrid drive device H or for charging or recharging the low-pressure storage device 8th with pressure medium from the container 5 the coupling device K is acted upon in a closed position to the positive displacement machine 1 to drive to the drive train, and the charging valve 32 by controlling the actuator M0 in the flow position 32b applied. The charging of the low-pressure storage device 8th can from the electronic control device based on the sensor devices 36 . 37 and with the sensor devices 36 . 37 determinable state of charge of the storage devices 7 . 8th be recognized and controlled. The valve devices 16 . 22 or the control valve device 116 are not driven and are in the in the 1 to 3 illustrated switch positions. The displacer driven by the drivetrain 1 thus operates in pump mode, in the pressure medium via the opening check valve 13 from the container 5 is sucked in and over the delivery line 6 , the charging line 31 and in the flow position 32b located charging valve 32 in the low pressure storage device 8th promotes. The displacement machine 1 can be used to initialize the hybrid drive H or to charge the low pressure storage device 8th be acted upon in the position with minimum displacement volume or by the electronic control device 35 by driving the adjusting device 1d be controlled in the displacer volume. In the electronic control device 35 For this purpose, an initialization mode is stored, in which the electronic control device 35 based on the sensor devices 36 . 37 too low a state of charge of the storage devices 7 . 8th for starting the initialization mode and a sufficient state of charge of the memory devices 7 . 8th to terminate the initialization mode.

For charging the high pressure storage device 7 with pressure medium from the low-pressure storage device 8th during energy recovery by a pump operation of the positive displacement machine 1 the coupling device K is acted upon in a closed position to the positive displacement machine 1 to drive to the drive train. In the 1 . 2 becomes the second valve device 22 by driving the actuator M1 in the pump operating position 22a applied. In the 1 is the first valve device 16 not activated and is in the pump operating position 16a , In the 2 is by appropriate control of the actuator M2, the first valve device 16 in the direction of the pump operating position 16a applied. In the 3 becomes the control valve device 116 by driving the actuator M1, the control valve device 116 in the direction of the pump operating position 116a applied. The loading valve 32 of the 1 to 3 is not activated and is in the locked position 32a , The positive displacement machine 1 is thus on the suction side S pressure fluid from the low pressure storage device 8th about that in the pump operating position 22a operated valve device 22 or via the in the pump operating position 116a operated control valve device 116 fed. The check valve 13 prevents outflow of pressure medium from the low pressure storage device 8th in the container 5 , The displacement machine 1 conveys via the delivery side F and over in the pump operating position 16a located valve device 16 or via the in the pump operating position 116a located control valve device 116 Pressure medium in the high pressure storage device 7 , In pump operation is the positive displacement machine 1 by driving the adjusting device 1d from the electronic control device 35 controlled in displacer volume. The charging of the high pressure storage device 7 by the pump operation of the positive displacement machine 1 This can be done in operating conditions in which a drive motor of the drive train provides excess energy, so that the loading and pressurizing the high pressure storage device 7 takes place with excess energy that accumulates in the primary side of the drive motor of the drive train in certain operating conditions. Alternatively or additionally, the charging of the high-pressure storage device 7 by the pump operation of the positive displacement machine 1 take place in a braking operation of a consumer of the drive train, so that the high pressure storage device 1 is charged by the braking energy and an energy recovery takes place. In a training of the consumer as a drive of a vehicle is thus in braking mode when decelerating the vehicle mass, the high pressure storage device 7 loaded with pressure medium under pressure.

In pump operation of the positive displacement machine 1 can that from the positive displacement machine 1 recorded torque via the continuously variable displacement volume of the positive displacement machine 1 in accordance with the current accumulator charging pressure of the high-pressure accumulator device 7 from the electronic control device 35 be set arbitrarily. If, when the vehicle is being decelerated, the current accumulator charging pressure of the high-pressure accumulator device 7 is not sufficient to a sufficiently high braking torque by the pump operation of the positive displacement machine 1 can build up, by controlling the retarder valve R of 1 or by controlling the valve device 16 in the direction of the additional control position 16c of the 2 or by controlling the control valve device 116 in the direction of the additional control position 116c of the 3 the pressure in the inlet of the high pressure storage device 7 set and raised according to a desired braking performance.

In the electronic control device 35 For this purpose, a high-pressure accumulator charging mode is deposited, the strategies for loading the high-pressure accumulator device 7 depending on the operating conditions of the drive train or the vehicle provides. The electronic control device 35 For example, operating states can be detected on the basis of corresponding input variables in which the drive motor supplies excess energy or a braking operation of the consumer takes place.

If a sufficiently charged high-pressure storage device 7 by means of the sensor device 36 from the electronic control device 35 can be detected in the high pressure storage device 7 stored energy by a motor operation of the displacement machine 1 be delivered to the drive train. In engine operation of the positive displacement machine 1 becomes the displacer machine 1 pressurized fluid from the high pressure accumulator device 7 fed to the suction side S, so that the displacement machine 1 from the pressure medium from the high pressure storage device 7 is driven and over the drive shaft 2 sends a torque to the drive train.

In engine operation of the positive displacement machine 1 the coupling device K is acted upon in a closed position to the positive displacement machine 1 to drive to the drive train. In the 1 and 2 we are the first valve device 16 by driving the actuator M2 in the engine operating position 16b applied. In the 3 becomes the control valve device 116 by driving the actuator M2 in the engine operating position 116b applied. The loading valve 32 of the 1 to 3 is not activated and is in the locked position 32a , Also in the 1 and 2 the second valve device 22 not activated and is in the engine operating position 22b , The positive displacement machine 1 is thus on the suction side S pressure fluid from the high pressure storage device 7 about in the engine operating position 16b operated valve device 16 or via the in the engine operating position 116b operated control valve device 116 fed. The check valve 13 prevents leakage of pressure medium from the high pressure storage device 7 in the container 5 , The displacement machine 1 conveys via the delivery side F and over into the engine operating position 16b located valve device 16 or over in the engine operating position 116b located control valve device 116 Pressure medium in the low pressure storage device 8th , In engine operation is the positive displacement machine 1 by driving the adjusting device 1d from the electronic control device 35 controlled in displacer volume.

In engine operation of the positive displacement machine 1 can that from the positive displacement machine 1 Torque delivered to the drive train via the continuously variable displacement volume of the positive displacement machine 1 in accordance with the current accumulator charging pressure of the high-pressure accumulator device 7 from the electronic control device 35 be set arbitrarily.

By the motor operation of the positive displacement machine 1 For example, when the drive motor is running, a torque assisting the drive motor can be delivered to the drive train in order to achieve a boost function, for example when accelerating or when the vehicle is stationary. Alternatively or additionally, by the engine operation of the displacement machine 1 a hydraulic starter for a start-stop function of the drive motor of the drive train are formed, which is the parked drive motor 1 within a short period of time. For the function as a hydraulic starter only need to be ensured that the high-pressure accumulator device 7 before stopping the drive motor has a sufficient state of charge for re-starting the drive motor.

In the electronic control device 35 For this purpose, a high-pressure accumulator discharge mode is deposited, the strategies for unloading the high-pressure accumulator device 7 depending on the operating conditions of the drive train or the vehicle provides.

The 5 shows a flowchart of the operating modes of the hydrostatic hybrid drive device H according to the invention, the electronic control device 35 is carried out.

When switching on the vehicle, for example by means of a key switch 90 , the hybrid drive H goes into the normal operation mode 100 ,

Is from the electronic control device 35 too low a charge state of the low-pressure storage device 8th is determined by the electronic control device 35 the initialization mode 101 initiated, as indicated by the arrow 102 is clarified. Is the low pressure storage device 8th through the initialization mode 101 sufficiently charged with pressure medium, goes the electronic control device 35 back to normal operating mode 100 as by the arrow 103 is clarified.

Is from the electronic control device 35 detects a braking operation of a consumer V of the drive train or the high-pressure storage device 7 for a later motor operation of the displacement machine 1 be charged with pressure medium, goes the electronic control device 35 in the high-pressure accumulator charging mode 104 as by the arrow 105 is clarified. If the high pressure storage device 7 in the pumping operation of the positive displacement machine 1 during the high pressure accumulator charging mode 104 is fully charged or the operating state of the vehicle changes, is by the controller 35 the high-pressure accumulator charging mode 104 finished and the hybrid drive H goes back to the normal operating mode 100 as by the arrow 106 is clarified.

If a deactivated internal combustion engine AM of the drive train by means of the displacement machine 1 be started or by a motor operation of the positive displacement machine 1 a booster drive to assist the running internal combustion engine AM are achieved, for example when accelerating the consumer, goes the electronic control device 35 in the high-pressure accumulator discharge mode 107 as by the arrow 108 is clarified. If the high pressure storage device 7 by the engine operation of the positive displacement machine 1 during the high-pressure accumulator discharge mode 107 is completely discharged or the operating state of the vehicle changes, is by the controller 35 the high pressure accumulator discharge mode 107 finished and the hybrid drive device goes back to the normal operating mode 100 as by the arrow 109 is clarified.

The hybrid drive device H according to the invention enables a compact, simple and cost-effective design.

In addition, the invention provides a robust and functionally reliable operating hydrostatic hybrid drive device H, resulting in particular advantages in the context of a start-stop function of the drive motor of the drive train, where due to a high number of starting operations, a robust and functionally reliable design of the starter of the drive motor is required.

By the execution of the positive displacement machine 1 as operated in an open circuit displacement machine, the same direction of rotation of the drive shaft 2 and the same flow direction of the pressure medium can work both as a pump and as a motor, there is a simple and cost-effective design of the positive displacement machine 1 , In the execution of the positive displacement machine 1 As in the displacement volume adjustable adjusting this special advantages are achieved in terms of a simple, compact and inexpensive construction, since only a one-sided adjustable adjusting is required, the adjustment of the displacer adjustment is simple and compact, so that a cost-effective and compact design running as adjustment Positive displacement machine results.

By the use of three pressure fluid reservoirs at different pressure levels, namely the high pressure storage device 7 , the low-pressure storage device 8th and the pressureless or low pressure container 5 is made possible by the connection of the housing interior of the positive displacement machine 1 with the container 5 , which is designed as a non-prestressed or slightly prestressed tank and communicates with the environment, the sealing means for sealing the housing interior from the environment in the region of the drive shaft 2 can be performed easily and inexpensively and no pressure-resistant and wear-prone radial shaft seal is required. During pump operation, the displacement machine points 1 by the suction-side connection with the prestressed low-pressure storage device 8th a high absorbency, which enables high performance of the hybrid drive device.

The hydrostatic hybrid drive device H of the invention 1 to 3 Due to the compact and simple design allows any installation options in a drive train of a vehicle, which in the 4a to 4e are clarified. In the 4a to 4e is the hydrostatic hybrid drive H shown simplified, with only the displacement machine 1 and the high pressure storage device 7 are shown.

In the 4a to 4e the powertrain A of a vehicle is shown, which comprises a drive motor AM, for example an internal combustion engine, and a consumer V driven by the drive motor AM. In the 4a to 4e is formed by integration of the hydrostatic hybrid drive device H according to the invention a parallel hybrid, in which the hybrid drive device H acts in addition to the drive motor AM as an energy source on the drive train A. As the drive motor AM may alternatively be provided an electric motor or a turbine.

In the 4a to 4e the consumer V of the vehicle is designed as a travel drive, which comprises a driven by a transmission G drive axle AA with at least two driven drive wheels A1, A2. The drive axle AA is designed as a differential axle, wherein a drive shaft AW of the drive train A drives a differential D of the drive axle AA and the differential D is connected via drive shafts TW1, TW2 to the driven wheels A1, A2.

That in the 4a to 4e illustrated transmission G can be designed as a continuously variable hydrostatic or continuously variable mechanical transmission, as a mechanical transmission, as a power shift transmission or as a hydrodynamic converter.

In the 4a to 4c is the hybrid drive H arranged in the drive train A in the direct drive. This is done on the displacement machine 1 a drive-through, so that the drive shaft 2 the displacer machine 1 forms a part of the drive shaft AW of the drive train A.

In the 4a is the hybrid drive H arranged in the drive train A between the drive motor AM and the transmission G. The drive shaft AW of the drive train A is provided between the hybrid drive device H and the transmission G with the coupling device K.

The 4b shows a further development of 4a , wherein on the drive shaft AW of the drive train A between the drive motor AM and the hybrid drive means H, the clutch means K is arranged and a further clutch means K1 between the hybrid drive means H and the transmission G is arranged.

In the 4c is the hybrid drive H arranged in the drive train A between the transmission G and the consumer V. The drive shaft AW of the drive train A is between the Gear G and the hybrid drive H provided with the coupling device K.

In the 4d an embodiment is shown, in which the vehicle next to the drive shaft AA, which is driven via the drive train A of the drive motor AM, an additional axis ZA, wherein the hybrid drive device H is drivingly connected to the additional axis ZA of the vehicle. The additional axis ZA is designed as a differential axis, wherein the displacement machine 1 the hybrid drive H by means of the drive shaft 2 a differential DZ of the additional axis ZA drives and the differential DZ via drive shafts TW3, TW4 is connected to the wheels A3, A4 of the additional axis ZA. In the power flow between the positive displacement machine 1 the hybrid drive device H and the additional axis ZA, the coupling device K is arranged.

In the 4e an embodiment is shown in which the hybrid drive H is connected via a transfer gear VG to the drive train A. The displacement gear VG is formed in the illustrated embodiment as a spur gear, which comprises a standing with the drive shaft AW spur gear S1 and a meshing with the spur gear S1 spur gear S2, with the drive shaft 2 the displacer machine 1 connected is. The displacement gear VG makes it possible to use the displacement machine 1 with the drive shaft 2 spaced parallel to the drive shaft AW of the drive train A to arrange. In the 4e Furthermore, the coupling device K is provided, by means of which the hybrid drive device H can be connected to the drive train A or separated from the drive train A. In the illustrated embodiment, the coupling device K is disposed between the drive shaft AW of the drive train A and the spur gear S1 of the transfer gear VG.

In the 4e the hybrid drive device H is integrated in the drive train A between the drive motor AM and a further clutch device K1, which is arranged between the drive motor AM and transmission G. The hybrid drive H is thus in the drive train A between the drive motor AM and the consumer V driving gear G according to the 4a arranged. It is understood that the connection of the hybrid drive device H to the drive train A by means of the transfer gear VG can be used analogously in the variants 4b to 4d.

Like from the 4a to 4e is clarified, the hydrostatic hybrid drive device H according to the invention can be installed due to the compact and simple design in a simple manner at any point in a drive train as a further source of energy to form a parallel hybrid. The hydrostatic hybrid drive device H according to the invention can therefore be adapted in a simple manner to different drive trains and different vehicles. The hydrostatic hybrid drive device H according to the invention can be combined with different transmissions G.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/071362 A1 [0008, 0008]

Claims (46)

Hydrostatic hybrid drive device (H) for a hybrid drive train (A), in particular of a vehicle, wherein the hybrid drive device (H) is a hydrostatic displacement machine ( 1 ), which has a drive shaft ( 2 ), which consists of a housing ( 3 ) of the positive displacement machine ( 1 ) and a housing interior of the positive displacement machine ( 1 ) in the area of the drive shaft ( 2 ) is sealed to the environment by means of a sealing device, characterized in that the hybrid drive device (H) is a high pressure storage device ( 7 ) and a low pressure storage device ( 8th ), wherein the bias voltage (P _H ) of the high pressure storage device ( 7 ) higher than the bias voltage (P _N ) of the low-pressure storage device ( 8th ), and the housing interior of the positive displacement machine ( 1 ) with a container ( 5 ), wherein the bias voltage (P _N ) of the low pressure storage device ( 8th ) higher than the pressure level of the container ( 5 ). Hydrostatic hybrid drive device according to claim 1, characterized in that the container ( 5 ) is formed as a non-preloaded container, which communicates with the environment, or is designed as a prestressed container. Hydrostatic hybrid drive device according to claim 1 or 2, characterized in that the high-pressure storage device ( 7 ) as prestressed accumulator ( 7a ), in particular bladder accumulator, piston accumulator or diaphragm accumulator is formed. Hydrostatic hybrid drive device according to one of claims 1 to 3, characterized in that the low-pressure storage device ( 8th ) as prestressed accumulator ( 8b ), in particular prestressed container, bladder accumulator, piston accumulator or diaphragm accumulator. Hydrostatic hybrid drive device according to one of claims 1 to 4, characterized in that the high-pressure storage device ( 7 ) and the low pressure storage device ( 8th ) is designed as a double piston accumulator. Hydrostatic hybrid drive device according to one of claims 1 to 5, characterized in that the displacement machine ( 1 ) is operated in the open circuit and is operable in the same direction of rotation and the same flow direction of a pressure medium as a pump and motor, wherein an outlet-side delivery side (F) of the displacement machine ( 1 ) a support line ( 6 ) connected in pump operation of the displacement machine ( 1 ) with the high pressure storage device ( 7 ) and during engine operation of the displacement machine ( 1 ) with the low pressure storage device ( 8th ), and wherein an inlet-side suction side (S) of the displacement machine ( 1 ) a suction line ( 10 ) connected in pump operation of the displacement machine ( 1 ) with the low pressure storage device ( 8th ) and during engine operation of the displacement machine ( 1 ) with the high pressure storage device ( 7 ), wherein for controlling the pump and motor operation of the displacement machine ( 1 ) a valve device ( 15 ) is provided. Hydrostatic hybrid drive device according to one of claims 1 to 6, characterized in that a charging device ( 30 ), which is a loading of the low-pressure storage device ( 8th ) by a pump operation of the displacement machine ( 1 ) with pressure medium from the container ( 5 ). Hydrostatic hybrid drive device according to claim 7, characterized in that the suction line ( 10 ) of the positive displacement machine ( 1 ) with the container ( 5 ) is connected to the suction line ( 10 ) at least one discharge line ( 11 . 12 ;) the high pressure storage device ( 7 ) and the low pressure storage device ( 8th ), the charging device ( 30 ) a check valve ( 13 ), which is in the intake ( 10 ) between the connection of the at least one discharge line ( 11 . 12 ;) and the container ( 5 ) and as a towards the container ( 5 ) blocking valve is formed. Hydrostatic hybrid drive device according to claim 7 or 8, characterized in that the charging device ( 30 ) a charging line ( 31 ) of the delivery line ( 6 ) of the positive displacement machine ( 1 ) to the low pressure storage device ( 8th ) and one in the charging line ( 31 ) arranged charging valve ( 32 ) having. Hydrostatic hybrid drive device according to claim 9, characterized in that the charging valve ( 32 ) a blocking position ( 32a ) and a flow position ( 32b ) having. Hydrostatic hybrid drive device according to claim 9 or 10, characterized in that the charging valve ( 32 ) is designed as a switching valve. Hydrostatic hybrid drive device according to one of claims 6 to 11, characterized in that in the delivery line ( 6 ) towards the displacement machine ( 1 ) blocking check valve ( 9 ) is arranged Hydrostatic hybrid drive device according to one of claims 6 to 12, characterized characterized in that the valve device ( 15 ) for controlling the pump and motor operation of the displacement machine ( 1 ) a first valve device ( 16 ) to the delivery line ( 6 ) of the positive displacement machine ( 1 ) to a high-pressure storage device ( 7 ) guided connection line ( 17 ), to one to the suction line ( 10 ) guided unloading line ( 11 ) of the high pressure storage device ( 7 ) and to a low-pressure storage device ( 8th ) guided connection line ( 18 ) connected. Hydrostatic hybrid drive device according to claim 13, characterized in that the first valve device ( 16 ) a pump operating position ( 16a ), in which the delivery line ( 6 ) of the positive displacement machine ( 1 ) to the high pressure storage device ( 7 ) guided connection line ( 17 ) and the discharge line ( 11 ) of the high pressure storage device ( 7 ) and to the low-pressure storage device ( 8th ) guided connection line ( 18 ) and an engine operating position ( 16b ), in which the to the high pressure storage device ( 7 ) guided connection line ( 17 ) with the discharge line ( 11 ) of the high pressure storage device ( 7 ) and the funding line ( 6 ) of the positive displacement machine ( 1 ) to the low-pressure storage device ( 8th ) guided connection line ( 18 ) connected is. Hydrostatic hybrid drive device according to one of claims 6 to 14, characterized in that the valve device ( 15 ) for controlling the pump and motor operation of the displacement machine ( 1 ) a second valve device ( 22 ), which in one to the intake ( 10 ) guided unloading line ( 12 ) of the low pressure storage device ( 8th ) is arranged. Hydrostatic hybrid drive device according to claim 15, characterized in that the second valve device ( 22 ) a pump operating position ( 22a ), in which the discharge line ( 12 ) of the low pressure storage device ( 8th ) and an engine operating position ( 22b ), in the discharge line ( 12 ) of the low pressure storage device ( 8th ) is locked. Hydrostatic hybrid drive device according to claim 15 or 16, characterized in that the second valve device ( 22 ) is designed as a switching valve. Hydrostatic hybrid drive device according to one of claims 6 to 12, characterized in that the valve device ( 15 ) for controlling the pump and motor operation of the displacement machine ( 1 ) a control valve device ( 116 ) to the delivery line ( 6 ) of the positive displacement machine ( 1 ) to a high-pressure storage device ( 7 ) guided connection line ( 17 ) and to one to the intake line ( 10 ) common unloading line ( 110 ) of the high pressure storage device ( 7 ) and the low pressure storage device ( 8th ) as well as to a low pressure storage device ( 8th ) guided connection line ( 18 ) connected. Hydrostatic hybrid drive device according to claim 18, characterized in that the control valve device ( 116 ) a pump operating position ( 116a ), in which the delivery line ( 6 ) of the positive displacement machine ( 1 ) to the high pressure storage device ( 7 ) guided connection line ( 17 ) and the common discharge line ( 110 ) with the low pressure storage device ( 8th ) guided connection line ( 18 ) and an engine operating position ( 116b ), in which the to the high pressure storage device ( 7 ) guided connection line ( 17 ) with the common discharge line ( 110 ) and the funding line ( 6 ) of the positive displacement machine ( 1 ) to the low-pressure storage device ( 8th ) guided connection line ( 18 ) connected is. Hydrostatic hybrid drive device according to claim 13 or 14 or 18 or 19, characterized in that the first valve device ( 16 ) or the control valve device ( 116 ) is designed as a switching valve. Hydrostatic hybrid drive device according to one of claims 1 to 20, characterized in that a brake torque generating device ( 65 ) provided in the pump operation of the displacement machine ( 1 ) on the positive displacement machine ( 1 ) generated upcoming braking torque. Hydrostatic hybrid drive device according to claim 21, characterized in that the brake torque generating device ( 65 ) has a retarder valve (R), which in the to the high pressure storage device ( 7 ) guided connection line ( 17 ) is arranged. Hydrostatic hybrid drive device according to claim 21, characterized in that the brake torque generating device ( 65 ) of an additional control position ( 16c ) of the first valve device ( 16 ) or the control valve device ( 116 ) is formed, in which the connection of the delivery line ( 6 ) of the positive displacement machine ( 1 ) to the high pressure storage device ( 7 ) guided connection line ( 17 ) can be throttled. Hydrostatic hybrid drive device according to claim 23, characterized in that the first valve device ( 16 ) or the Control valve device ( 116 ) is designed as a throttling in intermediate positions directional control valve. Hydrostatic hybrid drive device according to one of claims 9 to 24, characterized in that the valve device ( 15 ) and the loading valve ( 32 ) is electrically actuated and for actuation with an electronic control device ( 35 ) in communication with the input side of a storage pressure of the high pressure storage device ( 7 ) detecting sensor device ( 36 ) and a storage pressure of the low-pressure storage device ( 8th ) detecting sensor device ( 37 ). Hydrostatic hybrid drive device according to claim 25, characterized in that in the electronic control device ( 35 ) Operating strategies are stored in order to control the high-pressure storage device ( 7 ) depending on operating conditions of the vehicle with excess energy of a drive motor (AM) and / or during braking operation of the vehicle by a pump operation of the displacement machine ( 1 ) to charge. Hydrostatic hybrid drive device according to one of claims 1 to 26, characterized in that the displacement machine ( 1 ) in engine operation as a booster drive of the running drive motor (AM) and / or as a hydraulic starter of the parked drive motor (AM) is used. Hydrostatic hybrid drive device according to one of claims 25 to 28, characterized in that in the electronic control device ( 35 ) a charging strategy is stored in order to protect the low-pressure storage device ( 8th ) depending on the means of the sensor devices ( 36 . 37 ) detected states of the low pressure storage device ( 8th ) and the high pressure storage device ( 7 ) by a pump operation of the displacement machine ( 1 ) to charge. Hydrostatic hybrid drive device according to one of claims 1 to 28, characterized in that the high-pressure storage device ( 7 ) a pressure relief valve ( 41 ) assigned. Hydrostatic hybrid drive device according to claim 29, characterized in that the pressure relief valve ( 41 ) the high pressure storage device ( 7 ) to the low pressure storage device ( 8th ). Hydrostatic hybrid drive device according to one of claims 1 to 30, characterized in that the low-pressure storage device ( 8th ) a pressure relief valve ( 43 ) assigned. Hydrostatic hybrid drive device according to claim 31, characterized in that the pressure relief valve ( 43 ) the low-pressure storage device ( 8th ) to the container ( 5 ). Hydrostatic hybrid drive device according to one of claims 1 to 32, characterized in that the high-pressure storage device ( 7 ) by means of a relief valve ( 50 ) to the container ( 5 ) or to the low pressure storage device ( 8th ) is relieved and / or the low-pressure storage device ( 8th ) by means of a relief valve ( 51 ) to the container ( 5 ) is relieved. Hydrostatic hybrid drive device according to one of claims 1 to 33, characterized in that the drive shaft ( 2 ) of the positive displacement machine ( 1 ) is associated with a coupling device (K). Hydrostatic hybrid drive device according to one of claims 1 to 34, characterized in that the displacement machine ( 1 ) is formed as in the displacer volume unilaterally adjustable adjusting drive and a displacer volume adjusting device ( 1a ) of the adjusting engine starting from a position with a minimum displacement volume in a direction of adjustment is adjustable. Hydrostatic hybrid drive device according to claim 35, characterized in that the displacement volume adjusting device ( 1a ) by means of a hydraulic adjusting device ( 1d ) is adjustable, wherein the adjusting device ( 1d ) for supplying pressure medium with the low-pressure storage device ( 8th ) and / or with the high pressure storage device ( 7 ) and wherein the actuator ( 1d ) with the container ( 5 ). Hydrostatic hybrid drive device according to claim 35 or 36, characterized in that the displacement volume adjusting device ( 1a ) of the adjusting drive for driving with the electronic control device ( 35 ). Vehicle with a drive train (A) driven by a drive train (A) and a hydrostatic hybrid drive device (H) according to one of the preceding claims, characterized in that the drive train (A) is designed as a parallel hybrid and at least one consumer (V). Vehicle according to claim 38, characterized in that the consumer (V) is designed as a driven by a transmission (G) slewing gear. A vehicle according to claim 38, characterized in that the consumer (V) as one of a transmission (G) driven drive shaft (AA) with at least two driven drive wheels (A1, A2) is formed. Vehicle according to one of claims 38 to 40, characterized in that the hybrid drive device (H) in the drive train (A) is arranged in direct drive. Vehicle according to one of claims 38 to 40, characterized in that the hybrid drive device (H) via a displacement gear (VG), in particular a spur gear, with the drive train (A) is connected. Vehicle according to one of Claims 38 to 42, characterized in that the hybrid drive device (H) can be connected to the drive train (A) by means of a coupling device (K) and can be separated from the drive train (A). Vehicle according to one of claims 38 to 40, characterized in that the hybrid drive device (H) is drivingly connected to an additional axis (ZA) of the vehicle. Vehicle according to claim 44, characterized in that a coupling device (K) is arranged in the force flow between the hybrid drive device (H) and the additional axle (ZA). Vehicle according to one of claims 38 to 40, characterized in that the hybrid drive device (H) is drivingly connected to a power take-off of the drive motor (AM).

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