CA2865394C - Electric motor -driven pump - Google Patents

Abstract

In an electric motor-driven oil pump assembly for use with an engine in a vehicle, such as with an automatic engine-stop system in which an electric motor-driven oil pump is driven by an electric motor for hydraulic pressure supply to a transmission or engine of an automotive vehicle, at least in a stopped state of a mechanical oil pump driven by the engine, a controller for operating the motor for controlling the oil pump is provided in a housing proximal the flowing oil fluid such that the flowing oil fluid maintains the temperature of the controller below a predetermined temperature to avoid failure of the electronic components of the controller.

Description

I
ELECTRIC MOTOR -DRIVEN PUMP
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/603,907 filed February 27, 2012, which is available for public inspection in the databases of the United States Patent & Trademark Office ("USPTO").
FIELD

[0002] The present disclosure relates generally to pumps for use in generating a flow of a fluid. More particularly, the present disclosure relates to an oil pump controlled by a controller for generating a fluid flow such as an oil pump for use in an engine in a vehicle.
BACKGROUND

[0003] It is generally known that an oil pump is used to create a flow of fluid oil through an engine to cool and lubricate components of the drive train or engine during operation of the vehicle. It is also generally known to operate the oil pump using a power take off from the engine. In some applications, it is also generally known to provide an electric motor for operating the oil pump.
Typically, it is also known to provide a controller including a circuit board and other electronic components for use in controlling the oil pump during operation of the vehicle. Most of the current applications have the controller integrated at the back of the motor housing where it is cooled only by the air flow. These applications are limited by maximum ambient temperature and the amount of power (i.e., current) that the system can draw before the electrical components of the controller overheat and shut down.

[0004] So, if the electronic control apparatus is provided in the vehicle's power generation compartment, the temperature in the compartment generally creates a potential problem. While the air temperature in the compartment can be maintained at a sufficiently low temperature when a vehicle is moving and/or operating since fresh air flows can be used to transfer heat from the compartment, when the vehicle is stopped, such as after its high-speed running, the air stagnates in the compartment and is heated by the heat of the engine, with the result that the air temperature in the compartment rises to a relatively very high level which may lead to component fatigue, failure or other troubles.

[0005] To obtain an electric motor which is both compact and capable of delivering high output torque, a large current must be passed through the coil of the motor proper and thus the controller must be capable of providing such high current to the motor. Passing a large current through the coil of the motor and the controller used to manage the supply of electrical energy to the motor can cause the motor and/or the controller to heat up and if heated too high, to eventually fail.
Generally, it is required that the motor be cooled and that the controller be located at a distance from the motor and the heat source to protect the controller from extensive heat.
Further, it is generally known to use very expensive components in the controller capable of functioning properly at such elevated temperatures. Accordingly, space must be provided to locate the controller and the motor to be able to function.
However, it is very difficult to provide additional space for accommodating the installation of the electric motor and the controller because space is already very limited, particularly in the aforementioned motorized vehicle applications.
Thus, it is very difficult to provide both the electric motor and the pump in a limited space. This has made it almost impossible and very expensive to implement such an electric-motor-driven pump.

[0006] The present disclosure is based on the object of providing an electric motor-driven pump and control device by means of which the above-described problems of the prior art are avoided.
SUMMARY

[0007] In one exemplary embodiment, there is disclosed an electronic motor-driven pump and integrated controller including a housing in which the controller, including power control components (e.g., MOSFETS) for supplying power to the motor, is arranged for controlling the rotational speed of a fluid pump and the output of the fluid pump to be supplied to a vehicle component. The electronic motor-driven pump includes a motor portion located at one end, the fluid pump in the middle and an inlet/outlet housing portion including an integrated portion for containing the controller and its components such that the integrated portion is located proximal the flowing fluid in the inlet and outlet and has sufficient thermal conductivity to sufficiently dissipate heat from the controller located in a cavity formed in the inlet/outlet housing portion. The inlet/outlet housing portion may also include one or more passages which extend parallel to the central axis of the pump and the motor for receipt of the wires required for electrically coupling the controller and the stator of the motor such that the wires also pass through a sealed passage extending axially through the fluid pump. Additionally, the fluid passes through the pump and the electric drive-motor to dissipate heat from all of the components of the assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings illustrate, by way of example only, embodiments of the present disclosure wherein:

[0009] Fig. 1 is a perspective graphic view of an exemplary combined motor-driven pump and controller and housing system in accordance with the present disclosure;

[0010] Fig. 2 is an exploded, perspective graphic view of the combined motor-driven pump and controller and housing system of the exemplary embodiment of Fig.
1 in accordance with the present disclosure;

[0011] Fig. 3 is a cross-section, graphic view of the combined motor-driven pump and controller and housing system of the exemplary embodiment of Fig. 1 in accordance with the present disclosure;

[0012] Fig. 4 is an exploded, perspective, graphic view of an alternative embodiment of a combined motor-driven pump and controller and housing system of the exemplary embodiment of Fig. 1 in accordance with the present disclosure;

[0013] Fig. 5 is a perspective, graphic view of a thermal image analysis for the combined motor-driven pump and controller and housing system of the exemplary embodiment of Fig. 1 in accordance with the present disclosure;

[0014] Fig. 6 is a perspective, graphic view of an alternate exemplary embodiment of a combined electric motor-driven pump, controller and housing system in accordance with the present disclosure showing the details of the innovation;

[0015] Fig. 7 is a further alternate partial, perspective graphic view of the exemplary embodiment of Fig. 6 with the controller cover and the controller removed showing the passages for routing the wires for the controller and the motor;

[0016] Fig. 8 is a perspective, graphic view and a further alternate embodiment of 5 .. a pump for inclusion in a combined motor-driven pump controller and housing system displaying an alternate side for coupling the pump housing to the motor for including the controller within the housing and affecting cooling thereof;

[0017] Fig. 9 is a perspective, graphic view of a further alternate embodiment of a pump for inclusion in a combined motor-driven pump and controller and housing system similar to Fig. 8 and showing an alternate oil inlet/outlet member;

[0018] Fig. 10 is a cross-sectional, graphic view and the further alternate embodiment of a pump for inclusion in the motor-driven pump of the exemplary embodiment of Fig. 9 in accordance with the present disclosure;

[0019] Fig. 11 is a perspective, graphic view of a further alternate embodiment of .. a pump for inclusion in a combined motor-driven pump, controller and housing system similar to Fig. 8 and showing an alternate oil inlet/outlet member;

[0020] Fig. 12 is an exploded perspective, graphic view of the further alternate embodiment of a combined pump for inclusion in the motor-driven pump of the alternate exemplary embodiment of Fig. 11 in accordance with the present disclosure and showing an intersecting vane embodiment according to the present disclosure;

[0021] Fig. 13 is a perspective, graphic view of a further alternate embodiment of a pump for inclusion in the combined motor-driven pump and controller and housing system including an intersecting vane similar to Fig. 12;

[0022] Fig. 14 is a partial, perspective, graphic view of the further alternate embodiment of the pump for inclusion the combined motor-driven pump of the alternate exemplary embodiment of Fig. 13 in accordance with the present disclosure;

[0023] Fig. 15 is a perspective, graphic view of the further alternate embodiment of Fig. 12 showing the detail of the variable displacement pump and the intersecting vane design;

[0024] Fig. 16 is a partial, plan graphic view of the further alternate embodiment of Figs. 12 and 15 further showing the detail of the variable displacement pump and the intersecting vane design according to the present disclosure; and

[0025] Fig. 17 is a diagrammatic view and exemplary boundary diagram of the combined motor-driven pump and controller and housing system according to the present disclosure.
DETAILED DESCRIPTION

[0026] Referring in general to all of the figures, the present disclosure and teachings described herein provide for a combined motor-driven pump and controller system, hereinafter referred to as an electric motor-driven oil pump assembly 10, for use in automotive applications such as in association with a vehicle engine or drive train, such as a transmission. The electric motor-driven oil pump assembly 10 provides lubrication, cooling and pressure in various system configurations.
The primary elements of this electric motor-driven oil pump assembly 10 system are: the pump 20 which may be of any known or appropriate type (such as a fixed or variable displacement type pump), a motor 30, in particular a brushless direct current (DC) type motor, and a motor controller 40, such as a power inverter and an appropriate electrical connector for electrically coupling the electric motor-driven oil pump 10 to a source of electrical current power (such as a battery or similar type device).
In addition, the electric motor-driven oil pump assembly 10 may also include known and/or appropriate diagnostics and sensor signals (not shown). The electric motor-driven oil pump assembly 10 is configured such that the whole assembly may be fully integrated (i.e., the pump 20, motor 30, controller 40 and electrical connector) and contained in a single, sealed (integrated) body 60 due to system restrictions such as packaging. However, in application, such a system is exposed to high ambient temperatures due to mounting locations and positions directly on the transmission or engine body (not shown) and even sometimes locations inside the transmission body. In these applications, the electric motor-driven oil pump assembly 10 is typically exposed to potentially very severe environments including elevated temperatures. The most sensitive component to high ambient temperatures is the motor controller 40 which has the effect of limiting the maximum operating temperature of the electric motor-driven oil pump assembly 10.
Currently, maximum operating temperatures for the motor controller subcomponents are as generally: 175 degrees Celsius for the FET junction, 150 degrees Celsius for the motor controller unit MCU and 135 degrees Celsius for the capacitor.

[0027] To ensure that the noted temperature limits are not exceeded during maximum ambient temperature operation (Ta = 138 degrees Celsius), the oil pump 20 uses oil flow to cool the controller 40. Primarily, the benefit of the electric motor-driven oil pump assembly 10 according to the present disclosure is that it enables operation of the electric motor-driven oil pump assembly 10 under relatively higher ambient temperature conditions and at the same time provides for the possibility to reduce cost by using lower temperature grade electronic components as compared to known systems. As best shown in Fig. 5, pursuant to one set of exemplary operating conditions (i.e., ambient air at 138 degrees Celsius) the temperature of the oil flowing through the pump 20 keeps the oil at the inlet and at the outlet at 125 degrees Celsius which is below the noted temperature limits. Similarly, in Fig. 6 the oil flows at 4.5 liters per minute (Ipm) and the controller 40 is located in a first portion of an inlet/outlet housing 44 coupled to the oil pump assembly 20. The first portion of the inlet/outlet housing 44 includes a first cavity 42 for receiving the controller 40 therein and having a cover 46 secured to the inlet/outlet housing for sealing the controller 40 and its components in the first cavity. The material of the inlet/outlet housing 44 is preferably chosen to have a relatively high thermal conductivity such as a metal, such as aluminum or an aluminum alloy or other known or appropriate materials. The first cavity 42 in the inlet/outlet housing 44 includes at least a first passage 45 extending from the first cavity 42 to the pump 20 and to a stator of the brushless direct current motor 30. As best shown in the embodiment of Fig. 4, a bus-bar may be included in the motor assembly 30, coupled to the stator, and including an extension for passing through a sealed passage extending through the pump 20 and into the passage of the inlet/outlet housing for being coupled and electrically connected with the controller 40 therein.

[0028] As shown in the cross-section of Fig. 3, the controller 40 is located in the first cavity to be reasonably closely located proximate the inlet and outlet passages in the inlet/outlet housing 44 so that there is efficient heat transfer between the controller 40 and the fluid flowing therethrough. As the oil flows into the assembly 10, it will have a relatively lower temperature than the heat produced by the motor 30 and will flow through the pump 20, through the motor 30 and then back through the motor 30 and out of the inlet/outlet housing 44 where it will have a hydraulic pressure and flow to the vehicle component, such as a transmission or engine as well as, optionally, a heat exchanger where the oil may be cooled using any known or appropriate system and then returned to the assembly 10. In the embodiments shown, it is possible for the motor 30 to be completely sealed such that the fluid flowing through the motor is completely sealed such that the fluid does not and cannot contact any of the electrical components of the motor 30 or of the controller 40. A completely sealed assembly 10 is particularly significant and important for a fluid that may cause the electrical components to short, such as water.
Alternatively, for a fluid that will not cause the electrical components to short, it is possible for the motor 30 and the controller 40 to be partially sealed or unsealed such that the fluid is allowed to contact the electrical components and thereby increase the heat transfer away from the electrical components.

[0029] In an alternate embodiment shown in Figs. 8 through 14, the pump 120 is shown having a controller 140 located at one side surface of the pump 120. In particular, different types of pumps may be used such as the external rotor vane pump of Figs. 9 and 10 as well as the intersecting vane pump of Figs. 11 through 15 incorporating the teachings and disclosure of the present innovation. As should be understood from the present disclosure, it is possible to incorporate the teachings and disclosures of the present innovation into motor designs providing a variety of performance requirements and specifications including inter and out rotors, having between at least 12 Volts and 300 Volts applications. Further, it is possible to design the controller for providing a wide variety of design requirements such as FOG
and Block, and 12V and 300V applications as well as including a variety of control strategies (i.e., control strategies based upon motor speed, torque, and current as well as based upon pump pressure). Accordingly, it should also be understood that the assembly 10 of the present disclosure provides for a variety of communication protocols to be utilized including but not limited to PWM, K-line, LINE, CAN
or any other known or appropriate protocol. Accordingly, it is possible to provide an assembly 10 that is optimized to a significant variety of design specifications and 5 preferences.

[0030] In particular, it is contemplated that the assembly 10 according to the present disclosure, provides for a novel motor design for increasing the overall electric motor-driven pump performance while increasing the efficiency and reliability of the assembly 10 while reducing the costs of the components of the controller 40 10 and thereby the overall costs of the assembly 10.

[0031] Referring now in particular to the intersecting vane pump of Figs. 13 through 16 there is shown an oil pump 200. The pump 200 includes a top plate, a motor, and a pump outer rotor and a pump inner rotor, as best shown in Figs.
15 and 16. In particular, it should be understood that the outer pump rotor and the inner pump rotor both rotate with respect to the fixed bushing. Further of note is that the pump 200 includes first, second and third vanes (Vane 1, Vane 2, and Vane 3, respectively). Similar to the assembly 10 above, the pump 200 includes a controller (or PCB) coupled to a Base Plate and located under a Top (or Cover) Plate as best shown in Figs. 13 and 14. The controller (PCB) is installed on the back side of the Base Plate so its heat will be dissipated by the fluid flowing from the Inlet Port to the Outlet Port.

[0032] The internal components of the electric motor-driven oil pump 200 generally include the Motor Rotor, the Pump Outer Rotor, Vane 1, Vane 2, Vane 3, the Pump Inner Rotor and the Bushing all coupled together as shown. The Inlet Port and Outlet Port are located in the Base Plate and are coupled to the pump 200 for flowing the fluid through the pump using the intersecting vane design as shown.

[0033] The Pump Outer Rotor is preferably pressed into the Motor Rotor.
The Pump Outer Rotor includes at a first location a half circle or scallop on the inner bore of the Pump Outer Rotor for receiving a first end of Vane 1. Vane 1 extends from the scallop in the inner bore of the Pump Outer Rotor and through a first slot located transversely across the Pump Inner Rotor. Vane 2 and Vane 3 are installed in second and third slots of the Pump Inner Rotor and are each guided by the shaped contour of the inner circumference of the bore or passage of the Pump Outer Rotor.
The contour of the inner circumference of the bore or passage of the Pump Outer Rotor is shaped to affect the operation of the Vanes 1, 2, and 3 during rotation of the rotors for the pump 200 to perform consistent with desired design requirements.
When the motor 200 is working, the Motor Rotor and Pump Outer Rotor will rotate in a clockwise direction as shown in Fig. 15, and will drive Vane 1 and the Pump Inner Rotor and then will drive Vane 2 and Vane 3 but, the three Vanes will only swing back and forth during some angles related to the Pump Rotor to move fluid through the pump 200 causing oil to flow from the Inlet Port through the pump to the outlet port.

[0034] The configuration of the pump 200 according to the present disclosure is selected so the Pump Outer Rotor is a driving member and the Inner Rotor is driven by Vane 1 connected with Pump Outer Rotor. This type of pump driving method and configuration is unique so the contour of the inner circumference of the bore or passage of the Pump Outer Rotor is a pre-selected curve so that when the Pump Outer Rotor is rotated, the three Vanes 1, 2, and 3 will only swing back and forth during some angles related to the Pump Rotor.

[0035] The pump 200 of the present disclosure particularly benefits from the current design because the electric motor-driven oil pump 200 may work at high ambient temperature conditions while at the same time providing the possibility for significantly reduced cost by using lower temperature grade electronic components in the controller (PCB) as well as a reduced number of mechanical components making up the pump 200 as compared to conventional vane pumps thereby further reducing cost.

[0036] Any numerical values recited herein or in the figures are intended to include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc.
are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.
As can be seen, the teaching of amounts expressed as "parts by weight" herein also contemplates the same ranges expressed in terms of percent by weight. Thus, an expression in the Detailed Description of the Invention of a range in terms of at "'x' parts by weight of the resulting polymeric blend composition" also contemplates a teaching of ranges of same recited amount of "'x' in percent by weight of the resulting polymeric blend composition."

[0037] Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", inclusive of at least the specified endpoints.

[0038] The term "consisting essentially of" to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements, ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of the elements, ingredients, components or steps. By use of the term "may" herein, it is intended that any described attributes that "may"
be included are optional.

[0039] Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step.
Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps.
The disclosure of "a" or "one" to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps.

[0040] It is understood that the above description is intended to be illustrative and not restrictive. Many embodiments as well as many applications besides the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The omission in the following claims of any aspect of subject matter that is disclosed herein is not a disclaimer of such subject matter, nor should it be regarded that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims (11)

What is claimed is:

1. An electric motor-driven pump assembly for hydraulic pressure fluid supply, the assembly comprising:
an electric motor having a casing;
a pump having a pump housing with a first end and a second end and wherein the motor casing is coupled to the first end of the pump housing, the pump including a pump fluid passage connected to the motor for conveying fluid to the motor, wherein the pump further includes:
a fixed bushing;
a pump inner rotor coupled with the fixed bushing and rotating with respect to the fixed bushing;
a pump outer rotor surrounding the pump inner rotor and rotating with respect to the fixed bushing; and a plurality of vanes spaced from one another and extending through the pump inner rotor to the pump outer rotor;
a controller housing having a first end coupled to the second end of the pump housing, the controller housing including an inlet passage for receiving the fluid and an outlet passage for conveying the fluid, the inlet passage being connected to the pump fluid passage for conveying the fluid into the pump and through the motor to transfer heat from the motor to the fluid before the fluid flows back into the pump and out of the assembly through the outlet passage of the controller housing, wherein a first portion of the controller housing is located adjacent the inlet and outlet passages to provide heat transfer between the fluid and the first portion; and a controller located in the first portion of the controller housing and electrically connected to the motor for supplying power to the motor to thereby control the speed of the pump and the output of fluid from the pump, wherein heat produced by the controller is transferred to the fluid flowing through the inlet and outlet passages.

2. The assembly of Claim 1 wherein the controller housing includes a cavity located in the first portion, wherein the controller is located in the cavity, and wherein the controller housing includes a first passage for receiving wire leads to be coupled to the controller and the motor.

3. The assembly of Claim 2 wherein the pump and the motor are sealed to prevent fluid from contacting the controller.

4. The assembly of Claim 2 wherein the pump and the motor are not sealed such that fluid flowing through the pump is free to contact the controller to provide heat transfer from the controller to the fluid while not causing an electrical short in the controller or motor.

5. The assembly of Claim 1 wherein the inlet and outlet passage extend in a direction substantially perpendicular to the axis of the assembly.

6. The assembly of Claim 5 wherein the controller is aligned at an angle with respect to the axis of the assembly.

7. The assembly of Claim 1 wherein the controller housing comprises aluminum and the controller comprises at least one MOSFET for supplying conductive forces for inducing a magnetic field for controlling and driving the electric motor.

8. The assembly of Claim 1 wherein the electric motor includes a stator and a bus-bar coupled to the stator;
the controller housing includes a cavity located in the first portion and a first passage extending from the cavity to the pump, and the controller is located in the cavity;
the pump includes a sealed passage extending from the first passage of the controller housing to the electric motor;
and the bus-bar of the electric motor includes an extension passing through the sealed passage of the pump and into the first passage of the of the controller housing and is coupled to the controller.

9. The assembly of Claim 1 wherein the pump further comprises a knob and an intersecting vane received in and extending outwardly of the knob; and the electric motor includes a motor rotor surrounding the intersecting vane and a stator surrounding the motor rotor.

10. The assembly of Claim 1 wherein the electric motor includes a motor rotor and the pump outer rotor is pressed into the motor rotor;
the pump outer rotor presents an inner bore receiving an end of each of the vanes;
the pump inner rotor includes slots allowing the vanes to extend therethrough;
and wherein the motor rotor and the pump outer rotor rotate in the same direction and drive the pump inner rotor and a first one of the vanes followed by a second one of the vanes and a third one of the vanes, and the vanes swing back and forth at angles related to a curve presenting the inner bore of the pump outer rotor.

11. The assembly of Claim 1 wherein the electric motor includes a motor fluid passage for conveying the fluid, and the pump fluid passage is connected to the motor fluid passage for conveying the fluid to the motor.