Integrated pump device

Abstract

In an integrated pump device (10), a motor unit (20), a pump unit (30), and a substrate (26) are integrally formed. In the pump unit (30), a pump rotational body (pump gear) (32) accommodated in a pump housing (31) is rotated by a driving force of the motor unit (20), generating a hydraulic pressure for operating a hydraulic actuator unit (60). The substrate (26) is installed on a recessed substrate seating surface (36) provided in the pump housing (31), on the side facing the motor unit (30), and a plurality of electronic elements (266, 267, 268) constituting a control circuit for controlling the driving of the motor unit (20) are mounted on the substrate (26). At least in a portion where the electronic element that generates heat by energization, among the plurality of electronic elements, is mounted, a heat dissipation material (29) is applied or interposed between the substrate (26) and the substrate seating surface (36).

Description

Integrated Pumping Unit CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-043144, filed on March 19, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to an integrated pumping device.

[0003] Conventionally, there have been known devices in which a motor and an actuator are integrally provided. For example, the device disclosed in Patent Document 1 includes an electric motor, a circuit board having a control unit for controlling the electric motor, and an output shaft of a transmission. The circuit board is disposed between the electric motor and the output shaft of the transmission.

[0004] Patent Document 2 discloses an integrated pump device that integrates a motor, an oil pump, and a hydraulic parking lock actuator. The oil pump supplies oil for cooling or lubrication to an oil consumer such as a motor generator (MG) via the hydraulic parking lock actuator.

[0005] JP 2023-531627 A JP 2023-093012 A

[0006] The integrated pump device in Patent Document 2 converts electric power into hydraulic flow by driving an oil pump connected to the output shaft of a motor. When the pump is started, the power consumption required to start the motor increases due to factors such as oil pumping resistance. Furthermore, for example, in the case of an oil pump that supplies cooling oil to a motor drivetrain, the motor's power consumption also increases when the motor load is high and the required oil flow rate increases depending on the vehicle's running conditions.

[0007] When the motor consumes a lot of power, the electronic elements that make up the control circuit that drives the motor generate heat on the circuit board on which they are mounted, and the temperature of the electronic elements and the circuit board may exceed their heat resistance temperature. If a heat sink is provided specifically for heat dissipation, the size of the device increases, and the number of components increases. Patent Document 1 does not mention any solution to the problem of heat dissipation from electronic elements on the circuit board.

[0008] An object of the present disclosure is to provide an integrated pump device that drives an oil pump with the output of a motor and that effectively dissipates heat generated by electronic elements mounted on a board.

[0009] The integrated pump device of the present disclosure is an integrated unit comprising a motor unit, a pump unit, and a base plate. The pump unit has a pump rotor housed in a pump housing that rotates due to the driving force of the motor unit, generating hydraulic pressure that operates the hydraulic actuator unit.

[0010] The circuit board is placed on a circuit board seat recessed on the side of the pump housing facing the motor unit, and is equipped with a plurality of electronic elements that constitute a control circuit for controlling the driving of the motor unit.

[0011] At a portion where at least one of the electronic elements that generates heat when energized is mounted among the plurality of electronic elements, a heat dissipating material is applied or interposed between the substrate and the substrate seating surface.

[0012] The heat generated by the electronic elements mounted on the board is dissipated to the pump housing via a heat-dissipating material applied or interposed directly below the board. The heat received by the pump housing is then dissipated into the oil flowing inside the pump housing. This allows the heat generated by the electronic elements mounted on the board to be efficiently dissipated without the need for a dedicated heat sink.

[0013] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic axial cross-sectional view of an integrated pump device according to one embodiment, Fig. 2 is a view taken along line II-II in Fig. 1 as viewed from the hydraulic actuator unit side, Fig. 3 is a view taken along line III-III in Fig. 1 as viewed from the motor unit side, Fig. 4 is a configuration diagram of the integrated pump device and a parking lock mechanism, Fig. 5 is a diagram illustrating changes in the required oil amount depending on the vehicle's running state, Fig. 6 is a diagram showing the layout of electronic elements to be evaluated for cooling effectiveness, Fig. 7 is a diagram showing the cooling effect of applying a heat-dissipating gel to the electronic elements, Fig. 8 is a diagram showing the resonance point detection position, Fig. 9 is a diagram showing the application range of the heat-dissipating gel in the resonance evaluation, and Fig. 10 is a diagram showing the resonance suppression effect of applying the heat-dissipating gel.

[0014] An integrated pump device according to one embodiment will be described with reference to the drawings. The integrated pump device is configured to integrate at least a motor unit, a pump unit that operates a hydraulic actuator unit, and a substrate. The integrated pump device of this embodiment is primarily installed in electric vehicles such as electric vehicles and hybrid vehicles, and has both a PLA (parking lock actuator) function and an EOP (electric oil pump) function. The PLA function switches the parking lock mechanism between a locked state and an unlocked state. The EOP function supplies oil for cooling or lubrication to an oil consumer such as an MG (motor generator).

[0015] More specifically, the integrated pump device of this embodiment is mounted on, for example, an autonomous electric vehicle. When a command to start or park the vehicle is received from the vehicle's host control device, the integrated pump device activates the parking lock mechanism. The integrated pump device also adjusts the amount of oil supplied to the MG based on the MG speed, load, and other factors while the vehicle is running with the parking lock mechanism unlocked.

[0016] First, the overall configuration of one embodiment of the integrated pump device 10 will be described with reference to Figures 1 to 3. As shown in Figure 1, the integrated pump device 10 of one embodiment is integrally configured with a motor unit 20, a pump unit 30, a substrate 26, and a hydraulic actuator unit 60 that operates by hydraulic pressure supplied from the pump unit 30.

[0017] The motor section 20 and the pump section 30 are arranged coaxially with respect to a common motor axis O. In one embodiment, a rotary hydraulic actuator section 60 is used. The actuator axis Q of the hydraulic actuator section 60 is arranged coaxially with or parallel to the motor axis O. As will be described as "another embodiment," a cylinder-type hydraulic actuator section may also be used.

[0018] The motor section 20 has a stator 22 and a motor rotor 23 housed in a motor housing 21. A rotating magnetic field is generated by passing current through three-phase windings wound around the stator 22. The motor rotor 23 has multiple magnetic poles arranged circumferentially, and rotates in both directions in accordance with the rotating magnetic field of the stator 22. A motor output shaft 24 is fixed to and passes through the center of the motor rotor 23.

[0019] The end of the motor output shaft 24 on the motor housing 21 side is supported by a bearing 215, and the end opposite the motor section 20 is connected to an inner gear 321 of the pump gear 32. An oil seal 246 is provided in the middle of the motor output shaft 24 to seal off oil that leaks along the outer peripheral surface from the pump chamber 33 to the motor section 20 side.

[0020] In the pump unit 30, a pump gear 32 serving as a "pump rotor" housed in a pump housing 31 is rotated by the driving force of the motor unit 20 to generate hydraulic pressure that operates the hydraulic actuator unit 60. In one embodiment, the pump housing 31 is made of an aluminum alloy.

[0021] As shown in Figure 2, a pump chamber 33 is formed on the side of the pump housing 31 facing the hydraulic actuator unit 60. Rotation of the motor output shaft 24 causes the inner gear 321 to rotate inside the outer gear 322, thereby pressurizing and pumping oil from the pump chamber 33. When viewed from the perspective of Figure 2, clockwise rotation of the pump gear 32 is defined as "forward rotation," and counterclockwise rotation is defined as "reverse rotation." The operating direction of the hydraulic actuator unit 60 switches depending on the rotation direction of the pump gear 32.

[0022] A first oil passage 331 and a second oil passage 332 communicating with the pump chamber 33 are formed on both the left and right sides of the internal gear 321 in the figure. The first oil passage 331 is a discharge oil passage during reverse rotation, and communicates with the advance hydraulic chamber of the hydraulic actuator unit 60. The second oil passage 332 is a discharge oil passage during forward rotation, and communicates with the return hydraulic chamber of the hydraulic actuator unit 60. A spool valve 40 that switches the intake oil passage is provided upstream of the pump chamber 33. The spool valve 40 is housed in a valve hole 34 formed in the pump housing 31.

[0023] A cylindrical protrusion 37 that supports the motor output shaft 24 is provided in the center of the side of the pump housing 31 facing the motor unit 20. The circuit board 26 is mounted on a circuit board seating surface 36 that is recessed around the protrusion 37. The surface of the circuit board 26 facing the motor unit 20 is referred to as the "motor surface 261," and the surface facing the circuit board seating surface 36 is referred to as the "pump surface 262." A plurality of electronic elements 266, 267, and 268 that constitute a control circuit that controls the operation of the motor unit 20 are mounted mainly on the motor surface 261 of the circuit board 26. Power and signals are input to the control circuit from the outside via a connector 39 provided on the pump housing 31.

[0024] 3, the multiple electronic elements include a capacitor 266, an inductor 267, and a MOSFET (hereinafter referred to as "MOS") 268. For example, the capacitor 266 and the inductor 267 form an LC circuit as a noise suppression element for the power supply input section. A three-phase inverter circuit formed by multiple MOSFETs 268 converts DC power supplied from the vehicle battery to a connector 39 into three-phase AC power and supplies it to the three-phase windings of the brushless motor.

[0025] 1, at the locations where the electronic elements 266, 267, and 268 are mounted, a heat dissipating material 29 is applied or interposed between the pump surface 262 of the substrate 26 and the substrate seating surface 36. In one embodiment, a heat dissipating gel 29, which is a gel-like heat dissipating material, is applied between the substrate 26 and the substrate seating surface 36 directly below the electronic elements 266, 267, and 268. The technical significance of this configuration will be described later. Here, "directly below" means "a position directly behind the electronic elements across the substrate 26," and does not mean below in the vertical direction.

[0026] A pump plate 50 that forms an oil passage is provided between the pump section 30 and the hydraulic actuator section 60. The pump plate 50, together with the pump housing 31, constitutes the housing of the pump section 30. An intake port 67 and an exhaust port 68 are formed in a vane housing 61 of the hydraulic actuator section 60. The intake port 67 communicates with the valve hole 34 of the pump housing 31. The exhaust port 68 communicates with one of the vane chambers 62 in the vane housing 61.

[0027] Oil drawn into the intake port 67 is pumped through the communication space of the spool valve 40 by the rotation of the pump gear 32. The pumped oil is introduced into the vane chamber 62 of the hydraulic actuator unit 60 depending on the rotation direction of the pump unit 30. The oil is discharged from the discharge port 68 depending on the operating position of the vane rotor 63 and supplied to an oil consumer such as the MG97 as cooling oil or lubricating oil (see FIG. 4). The rotational output of the vane rotor 63 is transmitted to a detent mechanism of a parking lock mechanism 80 (see FIG. 4). The hydraulic actuator unit 60 operates the parking lock mechanism 80 by rotating the vane rotor 63 due to the hydraulic pressure generated in the pump unit 30.

[0028] Next, operation of the parking lock mechanism 80 by the integrated pump device 10 will be described with reference to Fig. 4. Fig. 4 shows an example of a system configuration. The parking lock mechanism 80 includes a detent mechanism including a detent shaft 81, a detent plate 82, a detent spring 83, and a detent roller 84, as well as a parking rod 85, a cone 86, a parking lock pole 87, a parking gear 88, etc.

[0029] The detent mechanism switches between a P position and a not-P position according to the output of the hydraulic actuator unit 60. The detent shaft 81 is connected to the rotary shaft of the vane rotor 63 of the hydraulic actuator unit 60 and rotates in both directions within a predetermined angular range by the operation of the vane rotor 63. The detent plate 82 is fixed to the detent shaft 81 and rotates together with the detent shaft 81. For example, in a two-position detent mechanism, the detent plate 82 has two valleys 821, 822 and a peak 825 on its radially outer edge. In other configurations, a detent mechanism with three or more positions may be used.

[0030] The detent roller 84, supported on the tip of the detent spring 83, fits into one of the two valleys 821, 822 due to the elastic force of the detent spring 83. When a rotational force greater than a predetermined value is applied to the detent plate 82, the detent spring 83 elastically deforms, and the detent roller 84 moves from one valley to the other, overcoming the peak 825. This switches between the P position and the not P position.

[0031] The parking rod 85 is formed in a generally L-shape, and one end 851 is fixed to the detent plate 82. A cone 86 is provided on the other end 852 of the parking rod 85, the diameter of which decreases as it approaches the other end 852. When the detent plate 82 rotates in a direction in which the detent roller 84 fits into the valley portion 821, the cone 86 moves in the direction of arrow P. When the detent plate 82 rotates in a direction in which the detent roller 84 fits into the valley portion 822, the cone 86 moves in the direction of arrow notP.

[0032] The parking lock pole 87 abuts against the conical surface of the cone 86 and is capable of swinging around a shaft 877. The parking lock pole 87 is provided with a protrusion 878 that can mesh with a parking gear 88. When the cone 86 moves in the direction of arrow P, the parking lock pole 87 is pushed up, and the protrusion 878 meshes with the parking gear 88, thereby establishing a locked state. When the cone 86 moves in the direction of arrow not P, the protrusion 878 separates from the parking gear 88, and the locked state is released.

[0033] In this way, the integrated pump device 10 realizes the PLA function by operating the hydraulic actuator unit 60 with hydraulic pressure supplied by the pump unit 30 using the driving force of the motor unit 20. Furthermore, the integrated pump device 10 also supplies oil for cooling or lubrication to oil consumers such as the MG97 through the EOP function in which the pump unit 30 rotates and discharges oil drawn in through the suction port 67 from the discharge port 68.

[0034] When the pump unit 30 is started, the power consumption required to start the motor increases due to factors such as oil pumping resistance. Furthermore, depending on the vehicle's driving conditions, the motor's power consumption also increases when the MG load is high and the required oil flow rate increases. Specifically, referring to FIG. 5 , the required oil amount and required motor rotation speed according to the vehicle's driving conditions will be described. A positive value of the required motor rotation speed indicates forward rotation of the motor rotor 23, and a negative value indicates reverse rotation of the motor rotor 23. The motor rotor 23 rotates forward when the vehicle is moving or the parking lock is released, and rotates reverse when the vehicle is stopped or the parking lock is engaged.

[0035] When traveling on flat ground, the MG load is steady. When traveling on an uphill road, the MG load increases, and the requested oil amount and the positive requested motor rotation speed increase from the values ​​when traveling on flat ground. When the vehicle stops after traveling on an uphill road, the requested motor rotation speed changes from positive to negative, and transitions from forward rotation to reverse rotation. While the requested oil amount and the absolute value of the negative requested motor rotation speed gradually decrease toward zero from the time the vehicle stops, MG cooling continues. When the requested oil amount and requested motor rotation speed reach zero, MG cooling stops.

[0036] The vehicle starts traveling again and moves to downhill driving. The MG load during downhill driving is smaller than when traveling on flat ground, and the required oil amount and required motor rotation speed remain constant at positive values ​​that are smaller than when traveling on flat ground. This state continues until low-load driving begins after traveling on the downhill road. When the vehicle stops after low-load driving, the absolute values ​​of the required oil amount and the negative required motor rotation speed temporarily increase to their maximum levels and then return to zero.

[0037] The vehicle's host control device inputs commands to activate and deactivate the parking lock, as well as a required motor rotation speed according to the vehicle's driving state, as a rotation instruction value, to the control circuit of the integrated pump device 10. The higher the rotation speed of the motor unit 20 in the integrated pump device 10, the greater the amount of oil discharged from the pump unit 30 to the MG 97.

[0038] When the motor power consumption is high like this, the electronic elements 266, 267, and 268 on the circuit board 26 generate heat, and there is a risk that the temperatures of the electronic elements 266, 267, and 268 and the circuit board 26 may exceed their heat resistance temperatures. If a heat sink dedicated to heat dissipation were provided for the circuit board 26 located in the space between the motor section 20 and the pump gear 32, the physical size of the device would increase and the number of parts would increase. Therefore, in one embodiment, as shown in Figure 1, a heat dissipation gel 29, which is a "heat dissipation material," is applied between the circuit board 26 and the circuit board seating surface 36 in the area where the electronic elements 266, 267, and 268 are mounted.

[0039] Heat generated by electronic elements 266, 267, and 268 mounted on substrate 26 is dissipated to pump housing 31 via heat dissipation gel 29 applied directly below substrate 26. Heat received by pump housing 31 is dissipated into oil, such as oil used to cool MG97, that flows inside pump housing 31. This allows the heat generated by electronic elements 266, 267, and 268 mounted on substrate 26 to be suitably dissipated without the need for a dedicated heat sink. In one embodiment, pump housing 31 is made of an aluminum alloy, a metal with high thermal conductivity, thereby further improving cooling performance.

[0040] In one embodiment, the heat dissipation material is a heat dissipation gel 29, i.e., a gel-like material. By using a gel-like material with a low Young's modulus, stress on the substrate 26 caused by the difference in thermal expansion of the components and various vibration stresses caused by being mounted on a vehicle are alleviated.

[0041] Next, with reference to FIGS. 6 to 10, the method and results of an evaluation test comparing the cooling effect and resonance suppression effect between an example in which the heat dissipation gel 29 was applied and a comparative example in which the heat dissipation gel 29 was not applied will be described.

[0042] 6 shows the arrangement of electronic elements 266, 267, and 268 on the motor surface 261 of the circuit board 26. Symbols C8 to C11 represent capacitors 266, symbol L represents inductor 267, and symbols M1 to M7 represent MOS 268. In the example, heat dissipation gel 29 was applied to the area enclosed by the dashed line frame. After energizing the control circuit for a predetermined period of time under predetermined drive conditions, the temperatures of the capacitor 266 (C8), inductor 267 (L), and MOS 268 (M3), marked with an asterisk, were measured.

[0043] 7 shows the results of comparing the temperatures of the electronic elements 266, 267, and 268 of the example and comparative example after energization. The vertical axis shows only relative temperature differences, not absolute values. The example in which the heat dissipation gel 29 was applied showed a temperature reduction of 8°C for the capacitor, 8°C for the inductor, and 16°C for the MOS, compared to the comparative example in which no heat dissipation gel was applied.

[0044] Figure 8 shows the position where the resonance point was detected in the resonance evaluation. On the motor surface 261 of the circuit board 26, the resonance point was detected at the protruding portion 37 (R portion) around which multiple capacitors 266 and inductors 267 were arranged. Figure 9 shows the application range of the heat dissipation gel 29 in the resonance evaluation. The heat dissipation gel 29 was applied to the circuit board seating surface 36 in the annular portion surrounding the protruding portion 37 and in the portions corresponding to the arrangement of the electronic elements 266, 267, and 268 (see Figure 8).

[0045] 10 shows the frequency characteristics of the resonance magnification in the 400 to 2000 Hz band. In the comparative example where no heat dissipation gel was applied, peaks of approximately 6 to 10 times the resonance magnification were observed around 800 Hz, 1100 Hz, and 1500 Hz. On the other hand, in the example where heat dissipation gel 29 was applied, the resonance magnification was suppressed to 1 to 2 times or less across the 400 to 2000 Hz band.

[0046] 9, the heat dissipation gel 29 is applied to all of the capacitors 266, inductors 267, and MOS 268 on the substrate 26. However, if the control circuit configuration includes "electronic elements that do not generate heat when energized" among the multiple electronic elements mounted on the substrate 26, the "electronic elements that do not generate heat when energized" may be excluded from the application of the heat dissipation gel 29. In other words, it is sufficient that the heat dissipation gel 29 is applied between the substrate 26 and the substrate seating surface 36 in "a portion where at least an electronic element that generates heat when energized is mounted among the multiple electronic elements."

[0047] (b) The configuration is not limited to one in which a gel-like heat dissipating material 29 is applied between the substrate 26 and the substrate seating surface 36, but a sheet-like (film-like) heat dissipating material 29 may also be interposed between the substrate 26 and the substrate seating surface 36.

[0048] (c) The pump housing 31 is not limited to being made of an aluminum alloy, and may be made of other metal materials with relatively high thermal conductivity. Alternatively, the pump housing 31 may be made of a resin material. Even if the pump housing 31 is made of a resin material, the pump housing 31 still has a cooling effect due to the flow of cooling oil inside.

[0049] (d) A rotating body other than a gear may be used as the "pump rotating body."

[0050] (e) The hydraulic actuator unit 60 may be provided separately from an integrated pump device in which the motor unit 20, the pump unit 30, and the base plate 26 are integrally configured. Furthermore, the hydraulic actuator unit 60 is not limited to a rotary hydraulic actuator, and a cylinder-type hydraulic actuator may also be used.

[0051] (f) The integrated pump device 10 of the present disclosure is not limited to use in operating the parking lock mechanism 80 of an electric vehicle. It may be used in any integrated pump device in which the driving force of the motor unit 20 rotates the pump unit 30 to generate hydraulic pressure that operates the hydraulic actuator unit 60.

[0052] As described above, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the present disclosure.

[0053] The present disclosure has been described based on the embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. An integrated pump device comprising: a motor section (20); a pump section (30) in which a pump rotor (32) housed in a pump housing (31) rotates by the driving force of the motor section, generating hydraulic pressure for operating a hydraulic actuator section (60); and a substrate (26) mounted on a substrate seat (36) recessed on the side of the pump housing facing the motor section, the substrate (26) having a plurality of electronic elements (266, 267, 268) constituting a control circuit for controlling the operation of the motor section, the substrate being installed in the substrate seat (36), and wherein a heat dissipation material (29) is applied or interposed between the substrate and the substrate seat at least in a portion where an electronic element that generates heat when current is applied thereto, among the plurality of electronic elements, is mounted.

2. The integrated pump device of claim 1, wherein the pump housing is made of an aluminum alloy.

3. The integrated pump device according to claim 1 or 2, wherein the heat dissipating material is a gel-like material.

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