JP4858783B2 - Fluid pump and vehicle drive device - Google Patents

Description

  The present invention relates to a fluid pump that includes a rotating body, a casing that houses the rotating body, and a shaft that passes through the casing and drives the rotating body, and uses the fluid pump for supplying lubricating oil. The present invention relates to a vehicle drive device.

  Such a fluid pump is used, for example, as an oil pump that supplies hydraulic pressure to an automatic transmission.

  That is, the oil supplied from the oil pump circulates in the automatic transmission, and this oil operates in the frictional engagement elements such as a brake and a clutch for switching the shift stage, and in the torque converter. The drive force is transmitted, and rotating members such as gears and shafts, and frictional engagement elements are lubricated.

  In such an automatic transmission, oil discharged from an oil pump is generally sent to a hydraulic control device called a valve body. In the valve body, the hydraulic pressure is adjusted to the hydraulic pressure for operating the friction engagement element, the hydraulic pressure for lubrication, and the like, and the oil is sent to each part via the hydraulic control valve.

  On the other hand, when the purpose of supplying oil is only to lubricate or cool rotating members such as gears and shafts, such as oil pumps used in vehicle drive devices that do not include frictional engagement elements such as clutches and brakes. Does not need to go through the valve body when supplying oil. In this case, the oil discharged from the oil pump is supplied directly into the shaft from the outside in the radial direction of the shaft from the pump provided on the outer periphery of the shaft, and the lubrication target such as gears and bearings arranged around the shaft from within the shaft is supplied. It is preferable to have a structure that supplies to the member from the viewpoint that the efficiency of the lubricating structure and the size of the entire drive device can be reduced. For this purpose, it is reasonable to configure the shaft so as to penetrate the casing and supply the oil to be discharged directly into the shaft within the casing. The following Patent Document 1 discloses such a configuration.

JP 2004-299497 A

  However, the oil pump described in Patent Document 1 is configured so that oil can be supplied directly into the shaft from the radially outer side of the shaft through the discharge oil passage provided in the casing. However, it cannot be said that sufficient consideration is given to oil sealing, which is important in oil pumps. That is, in this configuration, there is no structure for sealing the oil between the oil passage provided in the casing and the oil passage provided in the shaft, and in the vicinity of the end of the casing. The gap between the casing and the shaft is only sealed with a seal member. Therefore, there is a concern that oil leakage may occur when the sealing member is turned over due to hydraulic pressure, or when the sealing performance is deteriorated due to secular change.

  The present invention has been made in view of the above problems, and in a structure in which fluid discharged by driving a rotating body of a fluid pump is supplied to a flow path in a shaft that drives the rotating body, fluid leakage is prevented. An object of the present invention is to provide a fluid pump that can suppress an increase in the number of parts while being appropriately suppressed and can be downsized. It is another object of the present invention to provide a vehicle drive device in which such a fluid pump is appropriately arranged.

  In order to achieve this object, a characteristic structure of a fluid pump comprising: a rotating body according to the present invention; a casing that houses the rotating body; and a shaft that passes through the casing and drives the rotating body. The casing has a discharge channel through which fluid is discharged by driving the rotating body, and the shaft is rotatably supported by the casing via bushes at at least two positions on both sides of the rotating body in the axial direction. In addition, the bush having an in-shaft channel inside and the bush arranged on one side of the rotating body is a perforated bush having a through hole that communicates with the discharge channel and penetrates in the radial direction, The discharge channel is in communication with the channel in the shaft through the through hole.

According to the above configuration, the bush arranged on one side of the rotating body is a perforated bush, and the casing-side discharge flow path and the shaft internal flow path are communicated with each other through the through hole. An appropriate fluid can be sealed using a bush that is in contact with the casing and the shaft through a very narrow gap. Further, since the force acting on the perforated bush due to the fluid pressure is balanced in the axial direction of the shaft in the through hole, the bush can be prevented from moving due to the fluid pressure.
Further, since the flow path sealing structure is formed by using the bush provided to support the shaft to the casing, it is not necessary to add a new part for sealing the fluid, and such a new part It is not necessary to secure the arrangement space. Therefore, the increase in the number of components can be suppressed and the size can be reduced while appropriately suppressing the leakage of the fluid.
Furthermore, since the shaft is supported by the bushes at at least two locations on both sides of the rotating body, fluid leaking from the gap between the rotating body and the casing can be sealed by the bushes on both sides. Therefore, it can suppress that the fluid which leaked from the clearance gap between a rotary body and a casing flows out through the clearance gap between a casing and a shaft.

  Here, it is preferable that a groove-like flow path continuous in the circumferential direction is provided on one or both of the inner peripheral surface of the perforated bush and the outer peripheral surface of the shaft.

  According to this configuration, when the bush is fixed to the casing side, the discharge flow path and the in-shaft flow path are always in communication with each other via the groove-shaped flow path. Can always be supplied to the channel in the shaft.

  Further, the discharge flow path is formed so that a terminal end is opened on the inner peripheral surface of the casing facing the outer peripheral surface of the shaft, and the perforated bush has a position of the through hole of the discharge flow path. It is preferable that it is attached to the inner peripheral surface of the casing so as to coincide with the end portion.

  According to this configuration, when the bush is fixed to the casing side, a communication state between the discharge flow path and the in-shaft flow path can be ensured.

  Further, it is preferable that the in-shaft channel has a channel body extending in the axial direction and an introduction path extending radially outward from the channel body and communicating with the through hole of the perforated bush.

  According to this configuration, the fluid can be appropriately introduced in the axial diameter direction of the shaft, and further, the fluid can be guided in the axial direction of the shaft through the flow path body.

  Here, it is preferable that the in-shaft flow path further includes a fluid supply path that extends radially outward from the flow path main body and communicates with a supply target site.

  According to this configuration, the fluid introduced into the flow path in the shaft is jetted around the shaft using the centrifugal force generated with the rotation of the shaft through the fluid supply path, and supplied to the supply target site. be able to.

  In the fluid pump described so far, it is preferable that a seal member for sealing a gap between the casing and the shaft is provided on the opposite side of the rotating body with the perforated bush interposed therebetween.

  According to this configuration, even if a small amount of fluid passing through the through hole of the perforated bush oozes out to the outside of the perforated bush (on the opposite side of the rotating body in the axial direction), the seal member causes the casing and the shaft to Since the gap is sealed, the possibility of fluid leakage to the outside of the casing can be suppressed.

  Further, it is preferable that the rotating body is an inner gear and an outer gear constituting a gear pump.

  According to this configuration, the fluid pressure can be increased by using the inner gear and the outer gear. For example, since the structure is simple, the machining is easy and inexpensive, and the pulsation of the fluid to be discharged is increased by increasing the number of gear teeth. The effects as described above can be obtained while taking advantage of the gear pump, such as being able to reduce the size of the gear pump.

  The fluid pump having the above configuration includes, for example, a fluid pump in which the fluid is lubricating oil, an input shaft connected to the engine, a rotating electrical machine, a first rotating element, a second rotating element, and a third rotating element. A differential gear mechanism in which the first rotating element is connected to the rotating electrical machine, the second rotating element is connected to the input shaft, and the third rotating element is an output rotating element. And the input shaft is suitably used for a vehicle drive device having a structure that is the shaft of the fluid pump.

  According to this configuration, the engine drive can be distributed to the rotating electrical machine and the output rotating element by the differential gear mechanism. Further, since the input shaft, which is the shaft of the fluid pump, is connected to the rotating element of the differential gear mechanism, the radial load hardly acts on the input shaft. Therefore, the input shaft does not tilt in the casing, and fluid leakage can be suppressed from this point.

  Here, further comprising an output gear connected to the output rotation element of the differential gear mechanism, coaxially with the input shaft, from the engine side, the fluid pump, the output gear, the differential gear mechanism, It is preferable to arrange them in the order of rotating electric machines.

  According to this configuration, in the structure of the vehicle drive device in which the rotation input from the input shaft is transmitted to the output gear and the rotating electrical machine via the differential gear mechanism, the space existing between the engine and the output gear is provided. By disposing the fluid pump, it is possible to reduce the size of the vehicle drive device.

  Here, the counter gear mechanism further transmits the rotation of the output gear to the differential device, the counter gear mechanism includes a counter driven gear that meshes with the output gear, and a final drive gear that meshes with the final ring gear of the differential device. A countershaft that connects the counter driven gear and the final drive gear, and the final drive gear is disposed closer to the engine than the counter driven gear, and the fluid pump includes the countershaft and the final drive. It is preferable that it is arranged at a position overlapping with one or both of the gears in the axial direction.

  According to this configuration, in the structure of the vehicle drive device that transmits the rotation of the output gear to the counter gear mechanism, by further disposing the fluid pump in the space existing between the input shaft and the counter gear mechanism, It is possible to reduce the size of the vehicle drive device.

  Here, in the fluid pump, the perforated bush is disposed closer to the engine than the rotating body, and a seal member that seals a gap between the casing and the shaft is disposed closer to the engine than the perforated bush. It is preferable that

  According to this configuration, the seal member, the perforated bush, and the rotating body are arranged in this order from the engine side. Therefore, even if a small amount of fluid that passes through the through hole of the perforated bush oozes out to the outside of the perforated bush, the gap between the casing and the shaft is sealed by the seal member. It is possible to suppress leakage of fluid to the outside.

[Schematic configuration of drive unit]
Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a case where the fluid pump according to the present invention is applied to an oil pump OP that supplies lubricating oil to the vehicle drive device H will be described as an example. FIG. 1 is a skeleton diagram showing a schematic configuration of a vehicle drive device H according to the present embodiment. As shown in this figure, this vehicle drive device H includes an oil pump OP as a fluid pump that discharges lubricating oil, an input shaft I connected to the engine 31, and two rotary electric machines MG1 and MG2. And a planetary gear mechanism PG as a dynamic gear mechanism.

  The input shaft I is connected to the engine 31. Here, the engine 31 is an internal combustion engine that is driven by the combustion of fuel. For example, various known engines such as a gasoline engine and a diesel engine can be used. Although not shown, in this example, the input shaft I is integrally connected to an output rotation shaft such as a crankshaft of the engine 31. The rotation generated by driving the engine 31 is absorbed by the torsional vibration between the two shafts by the damper device 32 inserted between the output shaft of the engine 31 and the input shaft I of the vehicle drive device H. An input shaft I inputs the vehicle drive device H. Further, a transmission shaft T is provided on the side opposite to the input shaft I when viewed from the engine 31. The transmission shaft T and the input shaft I have the same shaft center and are connected so as to be relatively rotatable.

  The vehicle drive device H in the present embodiment has two rotating electrical machines MG1 and MG2. These rotary electric machines MG1 and MG2 are motor / generators that function as both a motor (electric motor) and a generator (generator) as necessary.

  The first rotating electrical machine MG1 includes a stator 2a fixed to the case, and a rotor 1a that is rotatably supported on the radially inner side of the stator 2a. The rotor 1a of the first rotating electrical machine MG1 is connected to rotate integrally with the transmission shaft T, and is connected to rotate integrally with the sun gear of the planetary gear mechanism PG via the transmission shaft T. A coil 3a is wound around the stator 2a, and the first rotating electrical machine MG1 mainly functions as a generator that generates electric power by rotation transmitted through the transmission shaft T. Note that the first rotating electrical machine MG1 also functions as a motor depending on the relationship between the rotational direction and the direction of the rotational driving force.

  The second rotating electrical machine MG2 has a stator 2b fixed to the case, and a rotor 1b rotatably supported on the radially inner side of the stator 2b. The rotor 1b of the second rotating electrical machine MG2 is connected to rotate integrally with the motor output shaft MO, and is connected to rotate integrally with the motor output gear 37 via the motor output shaft MO. A coil 3b is wound around the stator 2b, and the second rotating electrical machine MG2 mainly functions as a motor that generates torque by generating rotation. A motor output gear 37 is fixed to the motor output shaft MO, and torque generated by the rotation of the second rotary electric machine MG2 is transmitted to the motor output gear 37. Note that the second rotating electrical machine MG2 mainly functions as a motor, but the second rotating electrical machine MG2 functions as a generator at the time of regenerative braking for vehicle deceleration or the like.

  When these rotary electric machines MG1 and MG2 function as generators, the generated electric power is supplied to a battery (not shown) to be charged, or the electric power is supplied to the other rotary electric machine functioning as a motor for power running. In addition, when the rotating electrical machines MG1 and MG2 function as motors, they are charged by a battery or powered by the supply of electric power generated by the other rotating electrical machine functioning as a generator.

The differential gear mechanism includes three rotating elements, a first rotating element, a second rotating element, and a third rotating element. In the present embodiment, the differential gear mechanism is configured by a single pinion type planetary gear mechanism PG disposed coaxially with the input shaft I.
The planetary gear mechanism PG includes a carrier CR that rotatably supports a plurality of pinion gears P, and a sun gear S and a ring gear R that mesh with the pinion gears P as rotation elements. Assuming that the three rotating elements are a first rotating element, a second rotating element, and a third rotating element in the order of rotational speed, the sun gear S is the “first rotating element” of the differential gear mechanism in the present invention, and the carrier CR is The “second rotating element” and the ring gear R correspond to the “third rotating element”.
The sun gear S is connected via the transmission shaft T so as to rotate integrally with the first rotating electrical machine MG1. The carrier CR is connected to the input shaft I so as to rotate integrally. The ring gear R is an output rotation element and is connected to the output gear 33 so as to rotate integrally.

  The output gear 33 is a gear for transmitting the rotation of the ring gear R to the counter gear mechanism CG. The output gear 33 has a sleeve shape and is spline-engaged with the inner periphery of the ring gear R.

The vehicle drive device H according to the present embodiment further includes a counter gear mechanism CG that transmits the rotation of the output gear 33 to the differential device 39 arranged in parallel with the input shaft. The counter gear mechanism CG includes a counter driven gear 34 that meshes with the output gear 33, a final drive gear 36 that meshes with the final ring gear 38 of the differential device 39, a counter shaft 35 that connects the counter driven gear 34 and the final drive gear 36, Have A motor output gear 37 is engaged with the counter driven gear 34. Thus, the rotation of the output gear 33 and the rotation of the motor output gear 37 are reversed and transmitted to the counter driven gear 34.
The rotation transmitted to the counter driven gear 34 is transmitted to the final drive gear 36 via the counter shaft 35. The differential device 39 has a final ring gear 38 that meshes with the final drive gear 36. The rotation transmitted to the final ring gear 38 is distributed and transmitted to two drive wheels (not shown) by the differential device 39.

  As described above, the vehicle drive device H according to this embodiment can transmit the rotation generated by the engine 31, the first rotating electrical machine MG1 and the second rotating electrical machine MG2 to the counter driven gear 34 to drive the vehicle. Specifically, the vehicle is driven by switching between a motor drive mode for driving only the second rotary electric machine MG2 and a hybrid drive mode for driving all of the engine 31, the first rotary electric machine MG1 and the second rotary electric machine MG2. be able to.

In the vehicle drive device H described so far, the damper device 32, the oil pump OP as the fluid pump, the output gear 33, the planetary gear mechanism PG as the differential gear mechanism, and the first rotating electrical machine MG1 are the engine In this order from the 31 side, it is arranged coaxially with the input shaft I.
On the other hand, in the counter gear mechanism CG, the final drive gear 36 is disposed closer to the engine 31 than the counter driven gear 34. The oil pump OP is disposed at a position overlapping with both the countershaft 35 and the final drive gear 36 in the axial direction. In other words, the oil pump OP, the countershaft 35, and the final drive gear 36 are arranged at positions where they exist on a plane orthogonal to the input shaft I.

  Here, since the damper device 32 is disposed at a position on the axial engine 31 side avoiding the counter gear mechanism CG, the counter shaft 35 and the final drive gear 36 are interposed between the axial damper device 32 and the output gear 33. A space corresponding to is formed. Further, the final drive gear 36 is usually smaller in diameter than the counter driven gear 34. Therefore, a space is formed between the counter shaft 35 and the final drive gear 36 connected to the counter shaft 35 on the engine 31 side (damper device 32 side) of the counter driven gear 34 and the input shaft I. become.

  Therefore, the oil pump OP is utilized by utilizing a space formed between the damper device 32 and the output gear or a space formed between the input shaft I, the counter shaft 35 and the final drive gear 36 connected thereto. By arranging this, it is possible to reduce the size of the vehicle drive device H.

[Detailed structure of oil pump]
Next, details of the oil pump OP will be described. FIG. 2 is a diagram showing a detailed structure in the vicinity of the oil pump OP in the vehicle drive device H. FIG. 3 is an enlarged view of the vicinity of the rotating body 12. The oil pump OP includes a rotating body 12 and a casing 4 that houses the rotating body 12. The input shaft I passes through the casing 4 and drives the rotating body 12.

  In the present embodiment, the casing 4 has two members, a first casing 5 and a second casing 6, which are arranged on the radially outer side of the input shaft I. In the present specification, the casing 4 includes both the first casing 5 and the second casing 6 unless otherwise specified. In the present embodiment, the second casing 6 is disposed closer to the engine 31 than the first casing 5. An inner gear 13 and an outer gear 14 as a rotating body 12 are housed in a casing 4 constituted by the first casing 5 and the second casing 6 to constitute an oil pump OP.

  The first casing 5 has a substantially cylindrical shape having an inner peripheral surface 5i having a diameter slightly larger than the diameter of the input shaft I at the center, and is radially outward at one end (on the engine 31 side, right side in FIG. 2). A flange 7 is formed so as to extend. A cylindrical concave portion is provided in a portion in contact with the second casing 6 on the inner side in the circumferential direction of the flange 7. The concave portion serves as a pump chamber, and the rotating body 12 is accommodated therein. In the illustrated example, one side surface (the second casing 6 side) of the rotating body 12 and the contact surface 7a of the flange 7 with the second casing 6 are flush with each other in the axial direction.

The second casing 6 has a perforated disk shape having an inner peripheral surface 6i having a diameter slightly larger than the diameter of the input shaft I at the center, and one of them (the first rotating electrical machine MG1 side, the left side in FIG. 2). The side surface is a contact surface 6 a that contacts the flange 7 and the rotating body 12 of the first casing 5. In the second casing 6, there are provided a suction passage 10 for supplying lubricating oil to the rotating body 12 and a discharge passage 11 for discharging the lubricating oil by driving the rotating body 12. In the second casing 6, an end portion 10 e of the suction passage 10 provided so that the lubricating oil flows from the outside in the radial direction is formed by an inner gear 13 and an outer gear 14 as a rotating body 12 described later. It communicates with the suction port 15 of the gear pump. Further, one end of the discharge flow passage 11 is formed so as to communicate with the discharge port 16 of the gear pump, and the end portion 11e on the other end side is formed on the inner peripheral surface 6i of the second casing 6 facing the outer peripheral surface Io of the input shaft I. It is formed to open.
And the boss | hub part 8 which protrudes in the said opposite side is formed in the other side of the contact surface 6a of the 2nd casing 6. As shown in FIG. A cylindrical concave portion 24 is formed on the radially inner side of the boss portion 8, and an oil seal 23 that seals a gap between the input shaft I and the boss portion 8 is provided in the concave portion 24.

  The first casing 5 and the second casing 6 have a plurality of holes 25 having the same axial center in the circumferential direction, and are fixed to the device case 9 with bolts 26 through the holes 15.

  The input shaft I connected to the engine 31 passes through the casing 4 and drives the rotating body 12 disposed inside the casing 4. Therefore, the input shaft I corresponds to a “shaft” in the fluid pump according to the present invention. In the present embodiment, an inner gear 13 and an outer gear 14 constituting a gear pump are employed as the rotating body 12. That is, the oil pump OP includes an inner gear 13 that is spline-engaged with the input shaft I and integrally rotates, and an outer gear that is provided eccentrically on the outer side and is slightly larger than the inner gear 13 and that has a gear on the inner peripheral surface. And a gear 14. When the input shaft I rotates with the rotation of the engine 31, the meshing of the inner gear 13 and the outer gear 14 is separated and the gap is widened, or conversely, they are meshed with each other and the gap is narrowed. And discharging. Lubricating oil discharged by driving the inner gear 13 and the outer gear 14 flows out from the discharge flow path 11 connected to the discharge port 16.

By the way, when it is attempted to introduce the lubricating oil in the axial diameter direction from the discharge flow path 11 provided in the casing 4 to the introduction path fi of the in-shaft flow path 21, the lubricating oil is disposed between the discharge flow path 11 and the introduction path fi. If no measures are taken with respect to the sealing of the lubricant, the lubricating oil discharged by driving the rotating body 12 is a gap between the casing 4 and the input shaft I from the communicating portion of the discharge passage 11 and the introduction passage fi by the hydraulic pressure. Will flow out in the axial direction.
Further, the inner gear 13 and the outer gear 14 as the rotating body 12 are accommodated with a small gap with respect to the casing 4. Therefore, as shown in FIG. 3, most of the discharged lubricating oil flows out from the discharge flow path 11 (solid arrow), but a part of the gap between the casing 4 and the input shaft I passes through the gap by hydraulic pressure. (Broken arrow). Further, a force is applied to the lubricating oil so as to flow out so as to spread the gap between the casing 4 and the input shaft I in the axial direction on both sides of the rotating body 12 by hydraulic pressure.

  For this reason, as a countermeasure against leakage of the lubricating oil, the gap between the casing 4 and the input shaft I is usually sealed using an oil seal 23. However, as described in the background art section, if only the oil seal 23 is turned over due to the hydraulic pressure, or if the sealing performance is deteriorated due to secular change, the lubricating oil may leak. There is.

  In the present application, this problem is addressed by using the bush 17. That is, the input shaft I that penetrates the casing 4 is rotatably supported by the casing 4 via the bushes 17 at at least two locations on both sides of the rotating body 12 in the axial direction. In this example, one bush 18 is press-fitted into the inner peripheral surface 6 i of the second casing 6, and two bushes 17 are press-fitted into the inner peripheral surface 5 i of the second casing 5. Further, the inner peripheral surfaces of the bushes 17 and 18 slide in contact with the input shaft I with a very narrow gap, thereby supporting the input shaft I so as to be rotatable. Therefore, even if the lubricating oil leaks from the gap between the rotating body 12 and the casing 4, an appropriate lubricating oil is sealed using the bush 17, and the lubricating oil passes through the gap between the casing 4 and the input shaft I. Can be prevented from flowing out of the casing 4.

  Here, of these bushes 17, the bush 17 disposed on one side of the rotating body 12 is a perforated bush 18 having a through hole 19 that communicates with the discharge flow path 11 and penetrates in the radial direction. . Since the discharge flow path 11 is formed in the second casing 6, the perforated bush 18 is arranged closer to the engine 31 than the rotating body 12.

This perforated bush 18 is employed in expectation of the following actions in addition to the actions of the normal bush 17 as described above.
That is, firstly, the lubricating oil that has flowed out through the discharge flow path 11 can reach the outer peripheral surface Io of the input shaft I through the through hole 19. Therefore, the perforated bush 18 is attached to the inner peripheral surface of the casing 4 so that the position of the through hole 19 coincides with the end portion 11e of the discharge flow path 11.
Secondly, leakage of the lubricating oil in the axial direction from the communicating portion between the discharge flow path 11 and the in-shaft flow path 21 is suppressed. That is, the outer peripheral surface of the perforated bush 18 is press-fitted into the casing 4, and the inner peripheral surface slides in contact with the input shaft I with a very narrow gap. Therefore, it is possible to prevent the lubricating oil from flowing out in the axial direction from the gap between the inner peripheral surface of the casing 4 and the input shaft I at the communication portion between the discharge flow channel 11 and the shaft internal flow channel 21.
Thirdly, movement of the perforated bush 18 by hydraulic pressure is prevented. That is, in the communication portion between the discharge flow path 11 and the in-shaft flow path 21, the force by the hydraulic pressure of the discharged lubricating oil acts uniformly over the entire circumference of the through hole 19 of the perforated bush 18. Therefore, as shown by a double arrow in FIG. 3, the force acting on the perforated bush 18 by the hydraulic pressure of the lubricating oil is balanced in the axial direction of the input shaft I in the through hole 19. Therefore, for example, unlike the case where the separate bushes 17 are arranged on both sides in the axial direction of the communication portion between the discharge passage 11 and the in-shaft passage 21, the perforated bush 18 is formed by the pressure of the lubricating oil. It can be prevented from moving.

  As described above, in the present application, the bush 17 and the perforated bush 18 are used to form the channel sealing structure, but this bush 17 is usually provided to support the shaft on the casing 4. One of the parts. Therefore, it is not necessary to add new parts for sealing the lubricating oil, and it is not necessary to secure an arrangement space for such new parts. Therefore, it is possible to suppress the increase in the number of parts and reduce the size while appropriately suppressing the leakage of the lubricating oil.

  A seal member that seals the gap between the casing 4 and the input shaft I is provided on the opposite side of the rotating body 12 with the perforated bush 18 interposed therebetween. In the present embodiment, an oil seal 23 is provided between the cylindrical recess 24 formed on the radially inner side of the boss 8 of the second casing 6 and the input shaft I. The position where the oil seal 23 is disposed is closer to the engine 31 than the perforated bush 18. If such an oil seal 23 is provided, even if a small amount of lubricating oil that passes through the through hole 19 of the perforated bush 18 oozes out to the outside of the perforated bush 18, it is input to the casing 4 by the oil seal 23. Since the gap with the shaft I is sealed, it is possible to prevent the lubricating oil from leaking from the casing 4 to the outside on the engine 31 side. Therefore, it is possible to take thorough countermeasures against leakage of the lubricating oil.

  On one or both of the inner peripheral surface 18i of the perforated bush 18 and the outer peripheral surface Io of the input shaft I, a groove-like channel 20 that is continuous in the circumferential direction is provided. In the present embodiment, a groove-like channel 20 is provided on both of them. 4 is a cross-sectional view taken along the line IV-IV in FIG. As shown in this figure, a channel for the lubricating oil to flow in the circumferential direction of the input shaft I is formed by the groove-like channel 20. The lubricating oil that has reached the outer peripheral surface Io of the input shaft I flows along the groove-shaped flow path 20 and flows into the introduction path fi. Since the groove-like flow path 20 is provided at the same position in the axial direction with respect to the introduction path fi and the discharge flow path 11 and is formed over the entire circumference of the input shaft I, the input shaft I rotates with respect to the casing 4. Even in this state, the discharge flow path 11 and the in-shaft flow path 21 are always in communication with each other, and the lubricating oil discharged by driving the rotating body 12 can be constantly supplied to the in-shaft flow path 21.

  The input shaft I and the transmission shaft T have an in-shaft channel 21 therein. These in-shaft channels 21 communicate with each other. In the present specification, the in-shaft channel 21 means a combination of the in-shaft channels 21 of both the input shaft I and the transmission shaft T. The in-shaft channel 21 has a channel main body fb extending in the axial direction and an introduction channel fi extending radially outward from the channel main body fb and communicating with the through hole 19 of the perforated bush 18. The introduction path fi is a flow path for appropriately introducing the lubricating oil in the axial diameter direction of the input shaft I, and one or a plurality of the introduction paths fi are provided in the circumferential direction of the input shaft I. In this embodiment, the example which provided the four introduction paths fi in the position which divides the circumference | surroundings of the input shaft I into four equal parts was shown. Here, since the perforated bush 18 is attached to the inner peripheral surface of the casing 4 so that the position of the through hole 19 coincides with the terminal end portion 11e of the discharge flow path 11, the inside of the shaft is interposed through the through hole 19. The introduction path fi of the flow path 21 and the discharge flow path 11 communicate with each other. Specifically, the lubricating oil discharged by driving the rotating body 12 is supplied to the flow path body fb through the discharge flow path 11, the through hole 19, the groove-shaped flow path 20, and the introduction path fi. Become. Since the lubricating oil is discharged at a predetermined hydraulic pressure by the rotating body 12, even if the centrifugal hydraulic pressure acts due to the centrifugal force accompanying the rotation of the input shaft I, the lubricating oil is introduced from the introduction path fi to the flow path body fb. be able to. The lubricating oil supplied to the inside of the flow path body fb then flows to the planetary gear mechanism PG side (left side in FIG. 2) in the axial direction of the input shaft I.

The in-shaft channel 21 further includes a fluid supply path fo that extends radially outward from the channel body fb and communicates with a fluid supply site. One or more fluid supply paths fo are provided in the circumferential direction at one or more positions in the axial direction of the input shaft I. In this embodiment, at the position where the planetary gear mechanism PG is provided and the position where the bush 17 supporting the input shaft I is provided, the two fluid supply paths fo are divided into two halves around the input shaft I, respectively. The example in which one fluid supply path fo is provided at the position where the bearing 22 near the first rotating electrical machine MG1 is further provided is shown. These fluid supply paths fo are formed to have an inner diameter smaller than that of the introduction path fi.
When the input shaft I rotates as the engine 31 rotates, centrifugal force is generated. Lubricating oil is ejected from the fluid supply path fo around the input shaft I using this centrifugal force, and supplied to lubrication target members such as the planetary gear mechanism PG and each bearing to be lubricated. In the present embodiment, for example, a site where a lubrication target member such as the planetary gear mechanism PG is located is a supply target site.

[Other Embodiments]
(1) In the above-described embodiment, the example in which the groove-like flow path 20 continuous in the circumferential direction is provided on both the inner peripheral surface 18i of the perforated bush 18 and the outer peripheral surface Io of the input shaft I has been described. However, the groove-like channel 20 may be configured to be provided only in any one of these. In addition, for example, while widening the circumferential width of the discharge flow path 11, a large number of introduction paths fi are provided in the circumferential direction or the width in the circumferential direction is widened. If the communication state can be ensured, the groove-like channel 20 is not necessarily required.

(2) In the above embodiment, the example in which the bush 17 and the perforated bush 18 are fixed to the casing 4 side has been described. However, the bush 17 and the perforated bush 18 may be fixed to the input shaft I side. In this case, it is preferable that the groove-like flow path 20 is continuously provided in the circumferential direction of one or both of the outer peripheral surface of the perforated bush 18 and the inner peripheral surface of the casing 4 opposed thereto.

(3) In the above embodiment, an example in which an inscribed gear pump using the inner gear 13 and the outer gear 14 as the rotating body 12 is used has been described. However, the type is not limited as long as the fluid is discharged by driving the rotating body 12. For example, a circumscribed gear pump or vane pump can be used. In this case, the rotation axis of the rotating body 12 and the input shaft I may be the same or different.

(4) In the above embodiment, the example in which the perforated bush 18 is disposed closer to the engine 31 than the rotating body 12 has been described. However, the perforated bush 18 may be provided on the opposite side of the engine 31, that is, on the first rotating electrical machine MG1 side.

(5) In the above-described embodiment, the example in which the oil pump OP is arranged in the vehicle drive device H at a position overlapping with both the countershaft 35 and the final drive gear 36 in the axial direction has been described. However, the position where the oil pump OP is disposed may be a position overlapping only one of them in the axial direction.

(6) In the above embodiment, an example in which the rotating electrical machine is a motor / generator that performs both functions of a motor (electric motor) and a generator (generator) as necessary has been described. However, a rotating electrical machine specialized for a generator or a motor may be used. In that case, a configuration in which the first rotating electrical machine MG1 is a generator and the second rotating electrical machine MG2 is a motor is preferable.

(7) In the above embodiment, the example in which the planetary gear mechanism PG is employed as the differential gear mechanism has been described. However, it comprises three rotating elements, a first rotating element, a second rotating element, and a third rotating element, the first rotating element is connected to the rotating electrical machine, the second rotating element is connected to the input shaft, and the third rotating element Other differential gear mechanisms can be used as long as the element is an output rotating element.

(8) In the above embodiment, the example in which the single pinion type planetary gear mechanism PG is employed has been described. However, a double pinion type planetary gear mechanism PG may be adopted.

(9) In the above-described embodiment, an example in which the four introduction paths fi are provided at positions that equally divide the periphery of the input shaft I has been described. However, the number of introduction paths fi is not particularly limited. Similarly, an arbitrary number can be set for the number of fluid supply paths fo in the axial direction and the circumferential direction.

(10) In the above embodiment, the example in which the in-shaft channel 21 communicates with both the input shaft I and the transmission shaft T has been described. However, the in-shaft channel 21 may be formed only inside the input shaft I.

(11) In the above embodiment, the case where the fluid pump according to the present invention is applied to the oil pump OP that supplies lubricating oil to the vehicle drive device H has been described as an example. However, the target to which the fluid pump according to the present invention is applied is not limited to this, and various fluid pumps including a rotating body, a casing that houses the rotating body, and a shaft that passes through the casing and drives the rotating body. Can be applied to. Of course, it is possible to use a fluid other than the lubricating oil.

  The present invention can be suitably used for a fluid pump that includes a rotating body, a casing that houses the rotating body, and a shaft that passes through the casing and drives the rotating body. In addition, the fluid pump can be suitably used for a vehicle drive device that uses lubricating oil to be supplied.

Skeleton diagram showing schematic configuration of vehicle drive device Diagram showing the detailed structure near the oil pump Enlarged view of the vicinity of the rotating body IV-IV sectional view of FIG.

Explanation of symbols

4 Casing 11 Discharge flow path 12 Rotating body 17 Bush 18 Perforated bush 19 Through hole 20 Groove flow path 21 Shaft flow path 23 Oil seal (seal member)
31 Engine 33 Output gear 34 Counter driven gear 35 Counter shaft 36 Final drive gear 38 Final ring gear 39 Differential gear H Vehicle drive OP Oil pump PG Planetary gear mechanism (differential gear mechanism)
CG Counter gear mechanism MG1 First rotating electrical machine MG2 Second rotating electrical machine I Input shaft O Output shaft fb Flow path body fi Introduction path fo Fluid supply path

Claims (11)

A fluid pump comprising: a rotating body; a casing that houses the rotating body; and a shaft that passes through the casing and drives the rotating body,
The casing has a discharge passage through which fluid is discharged by driving the rotating body,
The shaft is rotatably supported by the casing via a bush at at least two positions on both sides of the rotating body in the axial direction, and has an in-shaft channel inside.
The bush arranged on one side of the rotating body is a perforated bush having a through hole that communicates with the discharge flow path and penetrates in a radial direction;
The discharge pump is a fluid pump that communicates with the in-shaft channel through the through hole.   2. The fluid pump according to claim 1, wherein a groove-like flow path continuous in a circumferential direction is provided on one or both of an inner peripheral surface of the perforated bush and an outer peripheral surface of the shaft. The discharge flow path is formed such that a terminal portion is opened on the inner peripheral surface of the casing facing the outer peripheral surface of the shaft,
3. The fluid pump according to claim 1, wherein the perforated bush is attached to an inner peripheral surface of the casing such that a position of the through hole coincides with the end portion of the discharge flow path.   The flow path in the shaft has a flow path body extending in the axial direction and an introduction path extending radially outward from the flow path body and communicating with the through hole of the perforated bush. A fluid pump according to claim 1.   5. The fluid pump according to claim 4, wherein the in-shaft flow path further includes a fluid supply path that extends radially outward from the flow path body and communicates with a supply target portion.   The fluid pump according to any one of claims 1 to 5, wherein a seal member that seals a gap between the casing and the shaft is provided on the opposite side of the rotating body with the perforated bush interposed therebetween.   The fluid pump according to any one of claims 1 to 6, wherein the rotating body is an inner gear and an outer gear constituting a gear pump. The fluid pump according to any one of claims 1 to 7, wherein the fluid is lubricating oil;
An input shaft connected to the engine;
Rotating electrical machinery,
Comprising three rotating elements, a first rotating element, a second rotating element, and a third rotating element, wherein the first rotating element is connected to the rotating electrical machine, the second rotating element is connected to the input shaft, A differential gear mechanism in which the third rotating element is an output rotating element,
The vehicle drive device, wherein the input shaft is the shaft of the fluid pump. An output gear coupled to the output rotating element of the differential gear mechanism;
The vehicle drive device according to claim 8, wherein the fluid pump, the output gear, the differential gear mechanism, and the rotating electric machine are arranged in this order from the engine side coaxially with the input shaft. A counter gear mechanism for transmitting rotation of the output gear to a differential device;
The counter gear mechanism includes a counter driven gear that meshes with the output gear, a final drive gear that meshes with a final ring gear of the differential device, and a counter shaft that connects the counter driven gear and the final drive gear.
The final drive gear is disposed closer to the engine than the counter driven gear,
The vehicle drive device according to claim 9, wherein the fluid pump is disposed at a position overlapping with one or both of the counter shaft and the final drive gear in the axial direction.   In the fluid pump, the perforated bush is disposed closer to the engine than the rotating body, and a seal member that seals a gap between the casing and the shaft is disposed closer to the engine than the perforated bush. The vehicle drive device according to claim 9 or 10.

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