Integrated pump system

Abstract

An integrated pump device (10) is configured such that a motor unit (20), a drive circuit (260), a pump unit (30), and a hydraulic actuator unit (60) are integrated. The motor unit (20) generates, for a motor shaft (24), energization torque during energization, and generates cogging torque when energization is stopped. The drive circuit (260) supplies power to the motor unit (20). The pump unit (30) converts torque generated upon energization of the motor unit (20) into hydraulic pressure. The hydraulic actuator unit (60) actuates a parking lock mechanism in accordance with the hydraulic pressure generated at the pump unit (30). The motor shaft (24) includes an exposed end portion (241) where an end portion of the motor shaft on the side opposite from the side of output to the pump unit (30) is exposed from a motor housing (21). The exposed end portion (241) has a rotational force transmission part (242) formed thereon, the rotational force transmission part being capable of transmitting rotational force from the outside.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is based on Japanese Patent Application No. 2024-043145 filed on March 19, 2024, the content of which is incorporated herein by reference. Technical Field

[0002] The present disclosure relates to an integrated pump device. Background Art

[0003] Conventionally, there has been known a device in which an electric oil pump and a hydraulic parking lock actuator are integrally provided. For example, the actuator disclosed in Patent Document 1 includes an electric oil pump portion and a park lock mechanism. In FIG. 1 of Patent Document 1, a pump is accommodated in a pump dome (30). An actuator cylinder (14) transmits power to a park lock mechanism (18).

[0004] Patent Document 2 discloses an integrated pump device in which a motor, an oil pump, and a rotary hydraulic parking lock actuator are integrally configured. Prior Art Documents Patent Documents

[0005] Patent Document 1 Chinese Patent Publication No. CN112912647B Specification Patent Document 2 Japanese Unexamined Patent Publication No. 2023-093012 Summary of the Invention

[0006] Patent Document 1 does not specify the specific structure of the motor portion and the peripheral portion of the control board, but the following points can be estimated from the drawings. [1] The motor portion is fixed to the housing (20) at an upper portion of the pump dome (30). [2] A motor control board (36) is fixed to an upper surface of the housing (20). [3] The control board accommodating portion is sealed by a casing.

[0007] Here, we consider a scenario in which, while the integrated pump device described in Patent Document 2 is in operation, the drive circuit or motor unit fails while the parking lock is engaged, preventing torque from being transmitted to the pump unit, and rendering the lock impossible to release. In this case, if the parking lock can be released by manually rotating the motor shaft, the vehicle can be towed. Patent Document 1 does not mention the problem of manually rotating the motor shaft when the motor unit fails, nor does it mention any configuration for solving this problem.

[0008] The purpose of this disclosure is to provide an integrated pump device that allows manual forced release of the parking lock state when the drive circuit or motor unit fails while the parking lock state is engaged.

[0009] The integrated pump device of this disclosure comprises a motor unit, a drive circuit, a pump unit, and a hydraulic actuator unit, all configured as a single unit. The motor unit has a stator and a motor rotor housed in a motor housing, and generates an energizing torque when power is supplied to a motor shaft fixed to the motor rotor, and generates a cogging torque when power is stopped. The drive circuit supplies power to the motor unit.

[0010] The pump unit converts the torque generated by the power supplied to the motor unit into hydraulic pressure. The hydraulic actuator unit activates the parking lock mechanism in accordance with the hydraulic pressure generated by the pump unit.

[0011] The motor shaft has an exposed end on the side opposite to the output side to the pump, which is exposed from the motor housing. This exposed end has a rotational force transmission section that can transmit rotational force from the outside.

[0012] In the integrated pump device of this disclosure, if the drive circuit or motor unit fails while the parking lock is engaged, the user can forcibly release the parking lock by manually rotating the motor shaft using the rotational force transmission unit at the exposed end. [Brief explanation of the drawing]

[0013] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken with the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic axial cross-sectional view of an integrated pump device according to an embodiment; [Figure 2] FIG. 2 is an exploded perspective view of an integrated pump device according to an embodiment; [Figure 3] FIG. 3 is a view showing first and second shape examples of a rotational force transmitting portion; [Figure 4] FIG. 4 is a view showing a first sealing structure example at a motor shaft insertion portion; [Figure 5] FIG. 5 is a view showing a second sealing structure example at a motor shaft insertion portion; [Figure 6] FIG. 6 is a view showing a third sealing structure example at a motor shaft insertion portion; [Figure 7] FIG. 7 is a configuration diagram of a parking lock mechanism; [Figure 8] FIG. 8 is a view explaining a vane rotor rotation angle (detent plate rotation angle); [Figure 9] FIG. 9 is a view showing a relationship between a vane rotor rotation angle and a detent mechanism load torque; [Figure 10] FIG. 10 is a view of a hydraulic actuator portion as viewed along line X-X in FIG. 1; [Figure 11] FIG. 11 is a view of a pump portion as viewed along line XI-XI in FIG. 1; [Figure 12] FIG. 12 is a view of a motor portion as viewed along line XII-XII in FIG. 1; [Figure 13] FIG. 13 is a view explaining torque acting on a motor shaft; [Figure 14] FIG. 14 is a diagram showing changes in vane rotor rotation angle φ and motor shaft rotation angle θ when manually rotating the motor shaft. DESCRIPTION OF EMBODIMENTS

[0014] One Embodiment An integrated pump device according to one embodiment will be described with reference to the drawings. In this integrated pump device, a motor section, a drive circuit, a pump section, and a hydraulic actuator section are integrally configured. The integrated pump device of the present embodiment is mainly mounted on electric vehicles such as electric vehicles and hybrid vehicles, and is a device that has both a PLA (parking lock actuator) function and an EOP (electric oil pump) function. The PLA function is a function for switching the parking lock mechanism between a locked state and an unlocked state. The EOP function is a function for supplying oil for cooling or lubrication to an oil consumer such as an MG (motor generator).

[0015] More specifically, the integrated pump device of the present embodiment is mounted on, for example, a self-driving electric vehicle. When a vehicle start or parking command is received from a host vehicle control circuit, the parking lock mechanism is actuated. Additionally, the amount of oil supplied to the MG is adjusted based on the rotational speed of the MG, load conditions, and the like while the vehicle is traveling with the parking lock mechanism unlocked.

[0016] Figures 1 and 2 show the overall configuration of an integrated pump device 10. The integrated pump device 10 is mainly configured integrally with a motor section 20, a pump section 30, and a hydraulic actuator section 60. The motor section 20 is constituted by, for example, a three-phase brushless motor, and outputs driving force for normal rotation and reverse rotation. The pump section 30 is constituted by a gear pump including a pump gear 32 composed of an inner gear 321 and an outer gear 322. The pump section 30 rotates (normally and reversely) by the driving force of the motor section 20, and discharges oil sucked from a suction port 67 to a discharge port 68. Power and signals are input from the outside via a connector 39 provided on a pump housing 31, which is a casing of the pump section 30. The hydraulic actuator section 60 operates to switch between an advanced state and a retracted state by hydraulic pressure supplied via the pump section 30.

[0017] In this embodiment, a rotary hydraulic actuator unit 60 is used. The motor unit 20 and the pump unit 30 are arranged coaxially with respect to a common motor rotation axis O. The vane rotation axis Q of the hydraulic actuator unit 60 is arranged coaxially or parallel to the motor rotation axis O. As will be described later in "Other Embodiments," the hydraulic actuator unit is not limited to a rotary type; a cylinder type configuration may also be adopted.

[0018] The motor unit 20 has a stator 22 and a motor rotor 23 housed in a motor housing 21. A rotating magnetic field is formed when current is supplied to the three-phase windings wound around the stator 22. The motor rotor 23 has multiple magnetic poles arranged in the circumferential direction and rotates according to the rotating magnetic field of the stator 22. A motor shaft 24 is fixed through the center of the motor rotor 23. The motor unit 20 generates current torque on the motor shaft 24 fixed to the motor rotor 23 when current is supplied. The motor unit 20 also generates cogging torque on the motor shaft 24 when the current is stopped.

[0019] The end 243 of the motor shaft 24 on the pump section 30 side is connected to an internal gear 321 housed in the pump chamber 33 of the pump housing 31. The torque generated by the motor shaft 24 when energized is transmitted to the internal gear 321. In other words, the end 243 is the "output end to the pump section 30".

[0020] The end 241 of the motor shaft 24 opposite to the output end 243 is inserted through a through hole 212 formed inside the retaining cylinder portion 211 of the motor housing 21, forming an "exposed end" that is exposed from the motor housing 21. The exposed end 241 has a rotational force transmission portion 242 that can transmit rotational force from the outside. The motor housing 21 is also provided with a removable sealing cover 217 that covers the exposed end 241. The technical significance of the exposed end 241, the rotational force transmission portion 242, and the sealing cover 217 will be described later. The motor shaft 24 is supported by the inner ring of the bearing 215 between the exposed end 241 and the motor rotor 23. The outer ring of the bearing 215 is fixed to the inner wall of the retaining cylinder portion 211.

[0021] The pump unit 30 converts the torque generated by the energization of the motor unit 20 into hydraulic pressure by the rotation of an internal gear 321 inside an external gear 322. An oil seal 246 is provided in the middle of the motor shaft 24 to seal off oil leaking from the pump chamber 33 to the motor unit 20. The pump housing 31 also has a valve hole 34 that houses the spool valve 40.

[0022] A circuit board 26, on which a drive circuit 260 that supplies power to the motor unit 20 is mounted, is installed on a substrate seating surface 36 recessed around the protrusion 37 of the pump housing 31. For example, the drive circuit 260 is composed of electronic elements such as switching elements like MOSFETs, inductors, and capacitors, and converts the DC power supplied from the vehicle battery to the connector 39 into three-phase AC power, which is then supplied to the three-phase windings of the brushless motor.

[0023] A pump plate 50 is provided between the pump section 30 and the hydraulic actuator section 60 to form an oil passage. The pump plate 50, together with the pump housing 31, constitutes the housing of the pump section 30. The internal configuration of the hydraulic actuator section 60 will be described later with reference to Figure 10. The vane housing 61 of the hydraulic actuator section 60 has an inlet 67 and a discharge port 68. The inlet 67 communicates with the valve hole 34 of the pump housing 31. The discharge port 68 communicates with the chamber bottom discharge opening 625 (see Figure 10) formed at the bottom of the first vane chamber 621 of the vane housing 61.

[0024] As shown in Figure 2, oil drawn from the oil tank 91 through the suction filter 92 and the like into the intake port 67 is pumped by the rotation of the pump gear 32 through the communication space of the spool valve 40. The pumped oil is introduced into the vane chamber of the hydraulic actuator 60 according to the rotation direction of the pump section 30. Depending on the rotation position of the vane rotor 63, the oil is discharged from the discharge port 68 and supplied to oil consumers such as the MG97 and the reduction gear.

[0025] The rotational output of the vane rotor 63 is transmitted to the detent mechanism of the parking lock mechanism 80 (see Figure 7). The hydraulic actuator 60 operates the parking lock mechanism 80 by rotating the vane rotor 63 in response to the hydraulic pressure generated by the pump 30.

[0026] Let's consider a scenario in which, while the integrated pump device 10 with the above configuration is in operation, the drive circuit 260 or motor unit 20 fails while the parking lock mechanism 80 is locked, preventing torque from being transmitted to the pump unit 30, and making it impossible to release the lock. For example, possible failure modes include damage to the switching element due to overheating of the drive circuit 260, or a short circuit or break in the motor winding due to friction caused by vehicle vibration.

[0027] If a malfunction occurs with the parking lock released, it is possible to drive to a dealer or be towed by another vehicle. However, if a malfunction occurs with the parking lock engaged, towing becomes difficult. Therefore, a device configuration is needed that allows the motor shaft 24 to be rotated manually to generate hydraulic pressure in the pump unit 30, and that the hydraulic pressure generated in the pump unit 30 to operate the vane rotor 63, thereby forcibly releasing the parking lock.

[0028] In this embodiment, a rotational force transmission unit 242 is formed at the exposed end 241 of the motor shaft 24. The rotational force transmission unit 242 is shaped to allow the user to manually transmit rotational force from the outside using a tool such as a wrench or spanner. When the drive circuit 260 or motor unit 20 fails while the parking lock is engaged, the user can forcibly release the parking lock by manually rotating the motor shaft 24 using the rotational force transmission unit 242 at the exposed end 241.

[0029] However, since the exposed end 241 is exposed by passing through the insertion hole 212 of the motor housing 21, a sealing structure is required to prevent the intrusion of moisture and other substances from the outside. Therefore, compared to an integrated pump device in which the motor shaft 24 does not have an exposed end, there is a problem of increased size and number of parts. To address this, the drive circuit 260, pump unit 30, and hydraulic actuator unit 60 are positioned on the opposite side of the motor rotor 23 from the exposed end 241 in the axial direction of the motor shaft 24, that is, in an area where the impact of the insertion of the exposed end 241 on sealing performance is small. By minimizing the parts that require sealing performance through a sealing structure, the increase in size and number of parts of the integrated pump device 10 can be minimized.

[0030] Furthermore, to prevent the motor shaft 24 from being rotated due to tampering or carelessness, it is preferable that the exposed end 241 is covered by the sealing cover 217 under normal circumstances. For example, the sealing cover 217 can be removed by prying off the edge that is bonded to the motor housing 21 with a tool or the like. Basically, if the sealing cover 217 is removed, it will be replaced, so the removed sealing cover 217 does not need to be reattachable.

[0031] Referring to Figure 3, examples 1 and 2 of the shape of the rotational force transmission section 242 will be described. For each shape example, a view of the end face of the exposed end 241 along the motor rotation axis O, and an axial cross-sectional view similar to that in Figure 1 are shown. In shape example 1, a rotational force transmission section 242a with a hexagonal hole corresponding to a hex wrench is formed on the end face of the exposed end 241a. In shape example 2, a rectangular prism-shaped rotational force transmission section 242b corresponding to a spanner, etc., is formed on the end face of the exposed end 241b. By forming the rotational force transmission section 242 in a shape that is compatible with commercially available tools rather than requiring special tools, user convenience is improved.

[0032] Referring to Figures 4 to 6, examples of sealing structures in the insertion portion of the motor shaft 24 will be described. In each example structure, a sealing member is provided to seal the space between the motor shaft 24 and the insertion hole 212 of the motor housing. The lead line of the reference numeral for the insertion hole 212 is drawn from the inner circumferential wall of the retaining cylinder portion 211 into which the inner ring of the bearing 215 is fitted.

[0033] In the seal structure example 1 shown in Figure 4, an O-ring 243 is provided on the outer circumferential wall of the motor shaft 24 facing the inner ring of the bearing 215, and an O-ring 213 is also provided on the outer ring of the bearing 215 facing the inner wall of the retaining cylinder portion 211, serving as the "sealing member". In the seal structure example 2 shown in Figure 5, a sealed bearing 215S is provided as the "sealing member". In the seal structure example 3 shown in Figure 6, an oil seal 216 is provided in series with the bearing 215 between the outer circumferential wall of the motor shaft 24 and the inner circumferential wall of the retaining cylinder portion 211, serving as the "sealing member".

[0034] These examples of seal structures allow the sealing function between the motor shaft 24 and the insertion hole 212 of the motor housing to be implemented with the minimum number of parts, while exposing the exposed end 241 to the outside. Therefore, compared to an integrated pump device in which the motor shaft 24 does not have an exposed end, the increase in size and the number of parts can be kept to a minimum.

[0035] Next, with reference to Figure 7, the configuration of the parking lock mechanism 80 will be described. Figure 7 shows an example of the 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 pawl 87, a parking gear 88, and the like.

[0036] The detent mechanism switches between the P position and the notP position by the output of the hydraulic actuator unit 60. The detent shaft 81 is connected to the rotation axis 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 configuration examples, a detent mechanism with three or more positions may be used.

[0037] The detent roller 84, supported at the tip of the detent spring 83, fits into one of the two valleys 821 and 822 due to the elastic force of the detent spring 83. When a rotational force exceeding a predetermined level is applied to the detent plate 82, the detent spring 83 elastically deforms, and the detent roller 84 moves from one valley over the peak 825 to the other valley. This switches between the P position and the notP position.

[0038] The parking rod 85 is formed in a roughly L-shape, with one end 851 fixed to the detent plate 82. The other end 852 of the parking rod 85 is provided with a cone 86 that decreases in diameter as it approaches the other end 852. When the detent plate 82 rotates in a direction that allows the detent roller 84 to fit into the valley 821, the cone 86 moves in the direction of arrow P. When the detent plate 82 rotates in a direction that allows the detent roller 84 to fit into the valley 822, the cone 86 moves in the direction of arrow not P.

[0039] The parking lock pole 87 contacts the conical surface of the cone 86 and is pivotable around the shaft portion 877. The parking lock pole 87 is provided with a protrusion 878 that can engage with the parking gear 88. When the cone 86 moves in the direction of arrow P, the parking lock pole 87 is pushed up, the protrusion 878 engages with the parking gear 88, and the vehicle is locked. When the cone 86 moves in the direction of arrow not P, the protrusion 878 disengages from the parking gear 88, and the vehicle is released from the lock state.

[0040] In this way, the integrated pump device 10 achieves the PLA function by operating the hydraulic actuator unit 60 with the hydraulic pressure supplied by the pump unit 30. The parking lock mechanism 80 is locked in the P position of the detent mechanism and unlocked in the notP position. Furthermore, the integrated pump device 10 supplies cooling or lubricating oil to oil consumers such as the MG97 through an EOP function in which the pump unit 30 rotates and discharges oil drawn in from the inlet 67 from the outlet 68.

[0041] Incidentally, load torque acts on the motor shaft 24 through the pump unit 30 from the parking lock mechanism 80. Even if one tries to manually rotate the motor shaft 24 in the unlocking direction, the load torque causes the motor shaft 24 to rotate in the opposite direction, making it difficult to release the parking lock. Therefore, it is necessary to set the cogging torque of the motor unit 20 in the power-off state to an appropriate value so that the motor shaft 24 does not rotate due to the load torque. The load torque acting on the motor shaft 24 will be explained below.

[0042] Referring to Figures 8 and 9, the relationship between the vane rotor rotation angle φ and the detent mechanism load torque Td will be explained. The detent plate 82, which is connected to the vane rotor 63 via the detent shaft 81, rotates together with the vane rotor 63. Therefore, the rotation angles of the detent plate 82 and the vane rotor 63 are represented by the same symbol "φ".

[0043] In the viewing direction of Figure 8, the vane rotor rotation angle φ is defined to increase counterclockwise from an arbitrary reference position Db. The rotation angle at the position where the detent roller 84 is engaged in the P valley 821 (position P) is denoted as φ0, the rotation angle when passing the peak of the peak 825 is denoted as φ1, and the rotation angle at the position where it is engaged in the not-P valley 822 (position not P) is denoted as φ2. The rotation angle φ1 is greater than the rotation angle φ0, and the rotation angle φ2 is greater than the rotation angle φ1 (φ0 < φ1 < φ2).

[0044] As shown in Figure 9, the detent mechanism load torque Td is 0 when the vane rotor rotation angle is φ0, and becomes positive as it begins to increase from φ0. Subsequently, the load torque Td decreases as the vane rotor rotation angle increases from φ0, and becomes 0 when it reaches φ1. In the range where the vane rotor rotation angle exceeds φ1 and extends to φ2, the load torque Td becomes negative as the detent roller 84 drops from the peak 825 towards the notP valley 822. When the vane rotor rotation angle reaches φ2, the load torque Td becomes 0 again.

[0045] Referring to Figures 10 to 12, the load torque transmitted from the detent mechanism to the motor shaft 24 of the motor unit 20 via the hydraulic actuator unit 60 and the pump unit 30 will be explained. Figures 10 to 12 are all views of the integrated pump device 10 from the detent mechanism side in direction D of Figure 7. In Figures 10 to 12, arrows indicating torque are shown around the vane rotation axis Q or the motor rotation axis O, but the direction of the arrows is not related to the definition of positive or negative torque. In actual design, the direction of positive or negative torque may be set as appropriate.

[0046] As shown in Figure 10, the hydraulic actuator unit 60 comprises a cylindrical vane housing 61 centered on the vane rotation axis Q, and a vane rotor 63 coaxially housed in the vane housing 61. The vane housing 61 has, for example, four vane chambers 621-624 inside. The vane chambers 621-624 have a fan shape, with the radially outer inner wall formed in an arc shape. In the figure, the leader lines of the reference numerals for the vane chambers 621-624 are drawn out from the radially outer inner wall.

[0047] The vane rotor 63 is provided with, for example, four vanes 641-644 corresponding to vane chambers 621-624. A sealing material is provided on the sliding portion of the radial outer wall of each vane 641-644. Each vane 641-644 is circumferentially rotatable in its corresponding vane chamber 621-624. Advance hydraulic chambers 651-654 are formed on one circumferential side of the vanes 641-644 in the vane chambers 621-624. A return hydraulic chamber 661-664 is formed on the other circumferential side of the vanes 641-644. Although not shown, the advance hydraulic chambers 651-654 communicate with each other via a distribution oil passage. Similarly, the return hydraulic chambers 661-664 communicate with each other via a distribution oil passage.

[0048] A bottom discharge opening 625 is formed at the bottom of one of the four vane chambers 621. Note that the bottom discharge opening 625 is located at the front of the illustrated cross-section and is therefore indicated by a dashed line. When the bottom discharge opening 625 is open, the oil from the first vane chamber 621 is supplied to the MG97 via the discharge port 68 (see Figure 1) through the bottom discharge opening 625.

[0049] The vane chamber 621 in which the chamber bottom discharge opening 625 is formed is called the "first vane chamber," and the vane 641 housed in the first vane chamber 621 is called the "first vane." In Figure 10, the vane chambers are designated as follows in counterclockwise order from the first vane chamber 621: second vane chamber 622, third vane chamber 623, and fourth vane chamber 624. Similarly, in Figure 10, the vane chambers are designated as follows in counterclockwise order from the first vane 641: second vane 642, third vane 643, and fourth vane 644. An intake port 67 connected to the oil tank 91 is formed between the second vane chamber 622 and the third vane chamber 623.

[0050] The forward-side hydraulic chambers 651-654 and the return-side hydraulic chamber 661 are connected to the first oil passage 331 and the second oil passage 332 (see Figure 11) of the pump unit 30, respectively. The hydraulic actuator unit 60 operates to switch between the forward and return states by the hydraulic pressure supplied from the oil passages 331 and 332 of the pump unit 30. When hydraulic pressure is supplied to the forward-side hydraulic chambers 651-654, the vane rotor 63 rotates clockwise in Figure 10 to enter the forward state. When hydraulic pressure is supplied to the return-side hydraulic chambers 661-664, the vane rotor 63 rotates counterclockwise in Figure 10 to enter the return state. The position of the vane rotor 63 in Figure 10 corresponds to the forward state.

[0051] Here, "advancing state" and "returning state" are merely terms used to conveniently distinguish between two opposing pole states, and either state may be defined as the advancing state or the return state. In this specification, the advancing state corresponds to position P, and the return state corresponds to position notP. The vane rotor rotation angle φ increases from position P to position notP.

[0052] In the following explanation, the units listed alongside the symbols for physical quantities represent dimensions and are not intended for direct numerical calculation. Conversion factors for digit alignment, such as [k] and [c], which represent the magnitude of numbers, will be omitted as appropriate. The detent mechanism load torque shown in Figure 9 is denoted as Td [Nm], and the load corresponding to the detent mechanism load torque Td is denoted as Fd [N]. Furthermore, the coefficient for converting the detent mechanism load torque Td to the hydraulic pressure of the hydraulic actuator section 60 is denoted as K1 [Nm / kPa], and the coefficient for converting the detent mechanism load Fd to the hydraulic pressure of the hydraulic actuator section 60 is denoted as K2 [N / kPa].

[0053] The differential pressure P1 or P2 acting on the forward hydraulic chambers 651-654 and the return hydraulic chambers 661-664 of the hydraulic actuator section 60 due to the operation of the detent mechanism is expressed by the following formula.

[0054] P1 = Td / K1 [kPa] P2 = Fd / K2 [kPa]

[0055] The differential pressure P1 or P2 is collectively represented as differential pressure P. For example, in the first vane chamber 621, a differential pressure P is generated between the leading hydraulic chamber 651 and the return hydraulic chamber 661, which are indicated by dashed hatching. The oil leakage from the vane rotor 63 due to the differential pressure P is expressed as qr × P [cc / min], where qr is the leakage rate per unit pressure [cc / min / kPa].

[0056] As shown in Figure 11, the pump unit 30 houses a pump gear 32 consisting of an inner gear 321 and an outer gear 322 in a pump chamber 33 formed in the pump housing 31. The rotation of the motor shaft 24 causes the inner gear 321 to rotate inside the outer gear 322, thereby pressurizing the oil in the pump chamber 33. In the viewing direction of Figure 11, clockwise rotation of the pump gear 32 is defined as "forward rotation," and counterclockwise rotation is defined as "reverse rotation." The rotation of the pump gear 32 is also referred to as the "rotation of the pump unit 30."

[0057] On both the left and right sides of the internal gear 321 in the diagram, a first oil passage 331 and a second oil passage 332 are formed, which communicate with the pump chamber 33. The first oil passage 331 is a discharge oil passage during reverse rotation and communicates with the forward-side hydraulic chambers 651-654 of the hydraulic actuator section 60. The second oil passage 332 is a discharge oil passage during forward rotation and communicates with the return-side hydraulic chambers 661-664 of the hydraulic actuator section 60. Upstream of the pump chamber 33, a spool valve 40 is provided to switch the intake oil passage.

[0058] If the rotational capacity of the pump section 30 (i.e., the spatial volume of the pump chamber 33) is c [cc / rev], then the pump load torque Tp [Nm] based on the differential pressure P [kPa] is expressed by the following formula.

[0059] Tp = P × c / 2π

[0060] Furthermore, the differential pressure P between the first oil passage 331 and the second oil passage 332 causes oil leakage from the vane rotor 63, as indicated by the arrow Lk. The oil leakage from the oil passage due to the differential pressure P is expressed as qp × P [cc / min], where qp is the leakage rate per unit pressure [cc / min / kPa].

[0061] As shown in Figure 12, the motor unit 20 is composed of an "8-pole, 12-slot" three-phase brushless motor, for example, with 8 magnetic poles on the motor rotor 23 and 12 slots on the stator 22. The motor shaft 24 connected to the internal gear 321 of the pump unit 30 is subjected to a pump load torque Tp. In addition, when the motor shaft 24 is rotated manually when the power supply is stopped, a cogging torque Tcog is generated.

[0062] Figure 13 shows the torque acting on the motor shaft 24 when the motor unit 20 is de-energized. Depending on the circumferential spacing of the magnetic poles of the motor rotor 23, the cogging torque Tcog fluctuates periodically with changes in the motor shaft rotation angle θ, from a negative peak value -TcogM to a positive peak value TcogM. In addition, a constant pump load torque Tp, independent of the rotation angle of the motor shaft 24, acts on the motor shaft 24 through the hydraulic actuator unit 60 and the pump unit 30.

[0063] Here, the peak cogging torque TcogM of the motor unit 20 in the power-off state is set to be greater than the pump load torque Tp acting on the motor shaft 24 through the hydraulic actuator unit 60 and the pump unit 30. In the example in Figure 13, the pump load torque Tp is a positive value, but if we include the case where the pump load torque Tp is defined as a negative value, this can be rephrased as, "The peak cogging torque TcogM is set to be greater than the absolute value of the pump load torque Tp."

[0064] This prevents the motor shaft 24 from rotating due to the action of the pump load torque Tp caused by the detent mechanism load torque Td, allowing the parking lock state to be forcibly released manually. A specific explanation will be given with reference to Figure 14.

[0065] The time chart of Fig. 14 shows changes in the vane rotor rotation angle φ and the motor shaft rotation angle θ when the motor shaft 24 is manually rotated using a ratchet wrench. For example, the hexagonal portion of the ratchet wrench is inserted into the hexagonal-hole-shaped rotational force transmitting portion 242. When rotation in the tightening direction of the ratchet wrench is defined as effective rotation, manual rotational force is transmitted when effective rotation is performed, and the ratchet wrench idles when rotated in the reverse direction. By operating the ratchet wrench, an effective rotation period Re and an idling period Ri are repeated.

[0066] As an example, the case where the peak cogging torque TcogM is larger than the pump load torque Tp (TcogM>Tp) is shown by a solid line. As a comparative example, the case where the peak cogging torque TcogM is smaller than the pump load torque Tp (TcogM<Tp) is shown by a broken line. Here, both the peak cogging torque TcogM and the pump load torque Tp are positive values. Both the motor shaft rotation angle θ and the vane rotor rotation angle φ increase in value as they go upward in the figure. Further, rotation in which the value of the rotation angle decreases is referred to as "reverse rotation".

[0067] In the example, the motor shaft rotation angle θ increases during the effective rotation period Re of the ratchet wrench and is maintained constant during the idling period Ri, thus increasing in a stepwise manner. During the effective rotation period Re, the vane rotor 63 rotates from φ0 (P position) toward φ1 by hydraulic pressure supplied from the pump unit 30 via rotation of the motor shaft 24. During the idling period Ri, the vane rotor 63 reverses by a minute angle due to the influence of oil leakage caused by the differential pressure acting on the hydraulic chambers on both sides of the vane.

[0068] As effective rotation and idling of the ratchet wrench are repeated, the vane rotor rotation angle φ increases while decreasing by a minute angle. When the vane rotor rotation angle φ reaches φ1, the detent mechanism load torque Td shifts to a negative value (see FIG. 9), so the rotation angle continues increasing to φ2 (notP position) as it is.

[0069] In the comparative example, the motor shaft rotation angle θ increases during the effective rotation period Re, but the motor shaft 24 rotates in the reverse direction due to the pump load torque Tp during the idle period Ri, canceling out the increase in the rotation angle θ during the effective rotation period Re. The vane rotor 63 rotates in conjunction with the rotation of the motor shaft 24 during the effective rotation period Re, but returns to its original position during the idle period Ri due to the reverse rotation of the motor shaft 24 in addition to the effect of oil leakage. Therefore, the parking lock cannot be released.

[0070] In contrast, in this embodiment, the peak cogging torque TcogM is set to be greater than the pump load torque Tp, so the motor shaft 24 does not rotate even when the load torque Td from the detent mechanism is acting. Therefore, it is possible to gradually rotate the motor shaft 24 using a ratchet wrench. This gradually supplies oil to the return side hydraulic chambers 661-664 of the hydraulic actuator unit 60. Although there is some effect due to oil leakage, the vane rotor 63 can be rotated to a rotation angle φ2 at the notP position. Therefore, the parking lock state can be forcibly released manually.

[0071] (Other embodiments) (a) The shape of the sealing cover 217 and the rotational force transmission section 242, and the sealing structure in the insertion section of the motor shaft 24 are not limited to those exemplified in Figures 1, 3 to 6, etc. Any shape or structure is acceptable as long as it has equivalent functionality.

[0072] (b) The hydraulic actuator unit 60 is not limited to a rotary hydraulic actuator, but a cylinder type hydraulic actuator may also be used.

[0073] The present disclosure is not limited in any way to the embodiments described above, and can be implemented in various forms without departing from its spirit.

[0074] (Disclosure of technical ideas) This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts.

[0075] (Technical thought 1) The motor unit (20) has a stator (22) and a motor rotor (23) housed in a motor housing (21), and a motor shaft (24) fixed to the motor rotor generates energizing torque when energized and cogging torque when energized is stopped. A drive circuit (260) that supplies power to the motor section, A pump unit (30) that converts the torque generated by energizing the motor unit into hydraulic pressure, A hydraulic actuator unit (60) that operates a parking lock mechanism (80) in accordance with the hydraulic pressure generated in the pump unit, It is composed as a single unit. The motor shaft has an exposed end (241) on the side opposite to the output side to the pump section, which is exposed from the motor housing, and the exposed end has a rotational force transmission section (242) formed thereon that can transmit rotational force from the outside, in an integrated pump device. (Technical thought 2) The integrated pump device according to Technical Concept 1, wherein the peak cogging torque of the motor section in the power-off state is set to be greater than the absolute value of the load torque acting on the motor shaft through the hydraulic actuator section and the pump section. (Technical Thought 3) The integrated pump device according to technical concept 1 or 2, wherein the drive circuit, the pump section, and the hydraulic actuator section are arranged with respect to the motor rotor on the side opposite to the exposed end in the axial direction of the motor shaft. (Technical Thought 4) An integrated pump device according to any one of the technical concepts 1 to 3, wherein a sealing member (243, 213, 215S, 216) is provided to seal the space between the motor shaft and the insertion hole (212) of the motor housing. (Technical Thought 5) An integrated pump device according to any one of technical ideas 1 to 4, wherein a removable sealing cover (217) is provided to cover the exposed end.

[0076] This disclosure is described in accordance with embodiments. However, this disclosure is not limited to such embodiments and structures. This disclosure also includes various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer elements, fall within the scope and idea of ​​this disclosure.

Claims

1. A motor unit (20) has a stator (22) and a motor rotor (23) housed in a motor housing (21), and a motor shaft (24) fixed to the motor rotor generates energizing torque when energized and cogging torque when energized is stopped, A drive circuit (260) that supplies power to the motor section, A pump unit (30) that converts the torque generated by energizing the motor unit into hydraulic pressure, A hydraulic actuator unit (60) that operates a parking lock mechanism (80) in accordance with the hydraulic pressure generated in the pump unit, It is composed as a single unit. The motor shaft has an exposed end (241) on the side opposite to the output side to the pump section, which is exposed from the motor housing, and the exposed end has a rotational force transmission section (242) formed thereon that can transmit rotational force from the outside, in an integrated pump device.

2. The integrated pump device according to claim 1, wherein the peak cogging torque of the motor section in the power-off state is set to be greater than the absolute value of the load torque acting on the motor shaft through the hydraulic actuator section and the pump section.

3. The integrated pump device according to claim 1 or 2, wherein the drive circuit, the pump section, and the hydraulic actuator section are arranged with respect to the motor rotor on the side opposite to the exposed end in the axial direction of the motor shaft.

4. The integrated pump device according to claim 1 or 2, wherein a sealing member (243, 213, 215S, 216) is provided to seal the space between the motor shaft and the insertion hole (212) of the motor housing.

5. The integrated pump device according to claim 1 or 2, wherein a removable sealing cover (217) is provided to cover the exposed end.

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