Oil pump structure for vehicle transmission

Abstract

To provide a highly reliable oil pump structure of a vehicle transmission which can supply a lubrication oil to a lubrication oil needing part with a simple structure even if a driving force is transmitted from a drive shaft whose rotation direction is changed according to a travel direction of a vehicle to an oil pump.SOLUTION: In an oil pump structure of a transmission 1, when a vehicle moves rearward, a driving force of a rearward movement output shaft 13 is transmitted from a drive gear 56 to a pump shaft 52 through an idler gear 58 and a driven gear 57 to rotate the pump shaft 52 in the same direction as a rotation direction when the vehicle moves forward. Further, when the vehicle moves rearward, the oil pump structure of the transmission 1 can be switched to a second state in which the pump shaft 52 and the rearward movement output shaft 13 are connected through the idler gear 58 and the driving force is transmitted from the rearward movement output shaft 13 to the pump shaft 52 through the idler gear 58.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an oil pump structure for a vehicle transmission. [Background technology]

[0002] 2. Description of the Related Art A transmission is known that includes an oil pump structure that is driven by a drive shaft whose rotation direction changes when the vehicle is moving forward and backward.

[0003] With an oil pump having such a configuration, the oil pump rotates in the reverse direction when the vehicle is reversed, which may cause lubricating oil in areas requiring lubrication to be sucked into the oil pump, resulting in a situation where the lubricating oil is unable to lubricate the areas requiring lubrication.

[0004] A hydraulic device for a four-wheel drive system, as described in Patent Document 1, is known as a device having an oil pump structure that can prevent such a situation from occurring.

[0005] This hydraulic system for a four-wheel drive system transmits the driving force output from the transmission to the front and rear wheels, and has an oil pump drive gear attached to a rotating member that rotates integrally with the front or rear wheel, and the driving force is transmitted from the oil pump drive gear to the oil pump.

[0006] The rotating member is a hypoid gear mount case that is partially immersed in lubricating oil, and an oil pump drive gear is attached to the rotating member via a one-way clutch that is disengaged when the vehicle is moving in reverse.

[0007] According to this hydraulic system for a four-wheel drive system, when the rotating member rotates in the reverse direction while the vehicle is moving backward, the one-way clutch is disengaged, thereby preventing the oil pump drive gear from rotating in the reverse direction.

[0008] Furthermore, a lubrication circuit for a transmission described in Patent Document 2 is known as an oil pump structure that can prevent the above-mentioned situation from occurring.

[0009] The lubrication circuit of this transmission includes an oil pump that rotates forward or backward, a pair of suction passages that branch off at a suction port that communicates with an oil reservoir and then communicate with the oil pump, a pair of check valves that are provided in the suction passages and supply lubricating oil only to the oil pump side, a pair of discharge passages that communicate with the oil pump and join at a discharge port, and a pair of check valves that are provided in the discharge passages and supply lubricating oil only to the discharge port side.

[0010] According to the lubrication circuit of this transmission, when the oil pump rotates in the normal direction, one check valve in the suction passage opens and the other check valve closes, and one check valve in the discharge passage opens and the other check valve closes.

[0011] On the other hand, when the oil pump rotates in the reverse direction, the other check valve in the suction passage opens and one check valve closes, and the other check valve in the discharge passage opens and one check valve closes.

[0012] This allows lubricating oil to be discharged from the oil pump regardless of whether the input rotation to the oil pump is in the forward or reverse direction, and lubrication can be performed both in the forward and reverse directions. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Utility Model Application Publication No. 1-141315 [Patent Document 2] Japanese Utility Model Application Publication No. 6-20951 Summary of the Invention [Problem to be solved by the invention]

[0014] However, in the hydraulic system for a four-wheel drive system described in Patent Document 1, when the rotating member rotates in reverse while the vehicle is moving backward, the one-way clutch is disengaged, preventing the oil pump drive gear from rotating and preventing lubricating oil from being supplied to parts that require lubrication when the vehicle is moving backward. In particular, when traveling uphill in reverse while moving uphill, it is not possible to supply lubricating oil for cooling to the motor, which is operating under high load, so it has become necessary to use an expensive motor or other cooling device that is durable even with insufficient cooling.

[0015] Furthermore, in the lubrication circuit of the transmission described in Patent Document 2, a large number of check valves are required, which makes the hydraulic path (oil passage) complex, and hydraulic paths and oil pumps with low leakage are required, which requires precision in the components of the lubrication circuit.

[0016] In addition, since it is necessary to operate the check valve, it is necessary to generate a relatively high hydraulic pressure, which may deteriorate the efficiency of the transmission in transmitting driving force.

[0017] The present invention has been made with the above-mentioned circumstances in mind, and aims to provide a highly reliable oil pump structure for a vehicle transmission that can supply lubricating oil to parts that require lubricating oil with a simple structure, even when driving force is transmitted to the oil pump from a drive shaft whose rotation direction changes depending on the direction of travel of the vehicle. [Means for solving the problem]

[0018] The present invention provides an oil pump structure for a vehicle transmission, which includes an oil pump having a discharge port for discharging lubricating oil and a suction port for sucking lubricating oil, the oil pump being driven by a pump shaft, and a drive shaft whose rotation direction changes depending on the direction of travel of the vehicle and which transmits driving force to the pump shaft, wherein the pump shaft and the drive shaft are installed on the same axis, The pump shaft and the drive shaft are each provided with a bevel gear that can mesh with the idler gear, a first state in which the pump shaft and the drive shaft are connected via a one-way clutch and a driving force is transmitted from the drive shaft to the pump shaft via the one-way clutch; The aforementioneda first state in which the drive shaft is connected to the pump shaft via an idler gear and a second state in which driving force is transmitted from the drive shaft to the pump shaft via the idler gear. [Effects of the Invention]

[0019] As described above, according to the present invention, even when driving force is transmitted to the oil pump from a drive shaft whose rotation direction changes depending on the direction of travel of the vehicle, a highly reliable oil pump structure for a vehicle transmission can be obtained that is capable of supplying lubricating oil to parts that require lubricating oil with a simple structure. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a skeleton diagram of a vehicle transmission equipped with an oil pump structure for a vehicle transmission according to a first embodiment of the present invention, showing the state of the oil pump structure when the vehicle is moving forward. [Figure 2] FIG. 2 is a skeleton diagram of a vehicle transmission equipped with an oil pump structure for a vehicle transmission according to a first embodiment of the present invention, showing the state of the oil pump structure when the vehicle is moving backward. [Figure 3] FIG. 3 is a skeleton diagram of a vehicle transmission equipped with an oil pump structure for a vehicle transmission according to a second embodiment of the present invention, showing the state of the oil pump structure when the vehicle is moving forward. [Figure 4] FIG. 4 is a skeleton diagram of an oil pump structure for a vehicle transmission according to a second embodiment of the present invention. [Figure 5] FIG. 5 is a skeleton diagram of a vehicle transmission equipped with an oil pump structure for a vehicle transmission according to a second embodiment of the present invention, showing the state of the oil pump structure when the vehicle is moving backward. DETAILED DESCRIPTION OF THE INVENTION

[0021] An oil pump structure for a vehicle transmission according to one embodiment of the present invention is an oil pump structure for a vehicle transmission having an oil pump driven by a pump shaft, the oil pump having an outlet for discharging lubricating oil and an inlet for sucking lubricating oil, and a drive shaft whose direction of rotation changes depending on the direction of travel of the vehicle and which transmits driving force to the pump shaft, the pump shaft and drive shaft being installed on the same axis and being switchable between a first state in which the pump shaft and drive shaft are connected via a one-way clutch and driving force is transmitted from the drive shaft to the pump shaft via the one-way clutch, and a second state in which the pump shaft and drive shaft are connected via an idler gear and driving force is transmitted from the drive shaft to the pump shaft via the idler gear.

[0022] As a result, the oil pump structure for a vehicle transmission in one embodiment of the present invention can provide a highly reliable oil pump structure for a vehicle transmission that can supply lubricating oil to parts that require lubricating oil with a simple structure, even when driving force is transmitted to the oil pump from a drive shaft whose rotation direction changes depending on the direction of travel of the vehicle. [Example]

[0023] An oil pump structure for a vehicle transmission according to an embodiment of the present invention will now be described with reference to the drawings.

[0024] (First Example) 1 and 2 are diagrams showing an oil pump structure for a vehicle transmission according to one embodiment of the present invention.

[0025] First, the configuration will be described. 1, a hybrid vehicle includes a transmission 1, an engine 2, and a motor 32. The transmission 1 of this embodiment constitutes a vehicle transmission.

[0026] An engine 2 is connected to the transmission 1. The engine 2 has a crankshaft 9, which is installed so as to extend in the width direction of the vehicle. That is, the engine 2 in this embodiment is a transversely mounted engine, and the vehicle in this embodiment is a front-engine, front-drive (FF) vehicle.

[0027] The transmission 1 includes an input shaft 11 , a forward output shaft 12 , a reverse output shaft 13 , a final reduction mechanism 14 , and a differential device 15 .

[0028] The input shaft 11, the forward output shaft 12 and the reverse output shaft 13 are installed in parallel along the left-right direction of the vehicle.

[0029] The input shaft 11 is connected to the engine 2 via the clutch 10, and the driving force of the engine 2 is transmitted via the clutch 10. The input shaft 11 has an input gear 16A for first gear, an input gear 16B for second gear, an input gear 16C for third gear, an input gear 16D for fourth gear, an input gear 16E for fifth gear, and an input gear 16F for sixth gear.

[0030] The input gears 16A and 16B are fixed to the input shaft 11 and rotate integrally with the input shaft 11. The input gears 16C to 16F are rotatable relative to the input shaft 11.

[0031] The forward output shaft 12 has an output gear 17A for the first gear, an output gear 17B for the second gear, an output gear 17C for the third gear, an output gear 17D for the fourth gear, an output gear 17E for the fifth gear, an output gear 17F for the sixth gear, and a forward final drive gear 17G.

[0032] The output gears 17A to 17F mesh with the input gears 16A to 16F that constitute the same gear stage. For example, the output gear 17D for the fourth gear stage meshes with the input gear 16D for the fourth gear stage.

[0033] The output gears 17A and 17B are rotatable relative to the forward output shaft 12. The output gears 17C to 17F and the final drive gear 17G are fixed to the forward output shaft 12 and rotate integrally with the forward output shaft 12.

[0034] In first gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16A and the output gear 17A. In second gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16B and the output gear 17B.

[0035] A first synchronizer 18 is provided on the forward output shaft 12 between the output gear 17A and the output gear 17B.

[0036] When shifting to first gear by a shift operation, the first synchronizer 18 connects the first gear output gear 17A to the forward output shaft 12. When shifting to second gear by a shift operation, the first synchronizer 18 connects the second gear output gear 17B to the forward output shaft 12.

[0037] In this way, when the gear is shifted to the first or second gear by a shift operation, the output gear 17A or the output gear 17B rotates integrally with the forward output shaft 12.

[0038] A second synchronizer 19 is provided on the input shaft 11 between the input gears 16C and 16D.

[0039] When shifting to third gear by a shift operation, the second synchronizer 19 connects the input gear 16C to the input shaft 11. When shifting to fourth gear by a shift operation, the second synchronizer 19 connects the input gear 16D to the input shaft 11. In this way, when shifting to third gear or fourth gear by a shift operation, the input gear 16C or input gear 16D rotates integrally with the input shaft 11.

[0040] In the third gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16C and the output gear 17C. In the fourth gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16D and the output gear 17D.

[0041] The second synchronizer 19 thus provided on the input shaft 11 selects one of a transmission gear set consisting of an input gear 16C and an output gear 17C and a transmission gear set consisting of an input gear 16D and an output gear 17D, and transmits driving force from the input shaft 11 to the forward output shaft 12 via the selected transmission gear set.

[0042] A third synchronizer 20 is provided on the input shaft 11 between the input gears 16E and 16F.

[0043] When the gear is shifted to fifth gear by a shift operation, the third synchronizer 20 connects the input gear 16E to the input shaft 11. When the gear is shifted to sixth gear by a shift operation, the third synchronizer 20 connects the input gear 16F to the input shaft 11.

[0044] In this way, when the gear is shifted to the fifth or sixth gear by a shift operation, the input gear 16E or the input gear 16F rotates integrally with the input shaft 11.

[0045] In the fifth gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16E and the output gear 17E. In the sixth gear, the driving force of the engine 2 is transmitted from the input shaft 11 to the forward output shaft 12 via the input gear 16F and the output gear 17F.

[0046] A reverse gear 22A and a reverse final drive gear 22B are provided on the reverse output shaft 13. The reverse gear 22A is rotatable relative to the reverse output shaft 13 and is meshed with the output gear 17A. The final drive gear 22B is fixed to the reverse output shaft 13 and rotates integrally with the reverse output shaft 13.

[0047] A fourth synchronizer 21 is provided on the reverse output shaft 13. When the vehicle is shifted to the reverse position by a shift operation, the fourth synchronizer 21 connects the reverse gear 22A to the reverse output shaft 13. As a result, the reverse gear 22A rotates integrally with the reverse output shaft 13.

[0048] In the reverse position, the driving force of the engine 2 is transmitted from the input shaft 11 to the reverse output shaft 13 via the input gear 16A, the output gear 17A that rotates relative to the forward output shaft 12, and the reverse gear 22A.

[0049] The forward final drive gear 17G and the reverse final drive gear 22B are meshed with the final driven gear 15A of the differential device 15. As a result, the driving force of the forward output shaft 12 and the driving force of the reverse output shaft 13 are transmitted to the differential device 15 via the forward final drive gear 17G or the reverse final drive gear 22B.

[0050] The differential device 15 has a final driven gear 15A, a differential case 15B having the final driven gear 15A attached to the outer periphery thereof, and a differential mechanism 15C housed in the differential case 15B.

[0051] One end of each of the right drive shaft 24R and the left drive shaft 24L is connected to the differential mechanism 15C, and the other ends of the left and right drive shafts 24L and 24R are connected to left and right drive wheels (not shown), respectively.

[0052] The differential device 15 distributes the driving force of the engine 2 to left and right drive shafts 24L, 24R by means of a differential mechanism 15C and transmits the power to the drive wheels.

[0053] The motor 32 includes a rotor (not shown), a stator around which a coil is wound, and a motor shaft 32A that rotates integrally with the rotor.

[0054] When a three-phase AC current is supplied to the coils of the motor 32, a rotating magnetic field is generated that rotates in the circumferential direction. The stator links the generated magnetic flux to the rotor, thereby driving the rotor, which is integral with the motor shaft 32A, to rotate.

[0055] The transmission 1 has a reduction gear mechanism 33. The reduction gear mechanism 33 is composed of a first drive gear 34 provided on the motor shaft 32A of the motor 32, a first intermediate shaft 35, a second intermediate shaft 36, and a fourth-speed output gear 17D provided on the forward output shaft 12.

[0056] A first driven gear 35A and a second drive gear 35B are provided on the first intermediate shaft 35. A second driven gear 36A and a third drive gear 36B are provided on the second intermediate shaft 36.

[0057] The third drive gear 36B is formed integrally with the second intermediate shaft 36. The second driven gear 36A is attached to the second intermediate shaft 36 via a ball spline bearing (not shown), and is capable of rotating integrally with the second intermediate shaft 36 in the circumferential direction and moving axially.

[0058] The first driven gear 35A is formed to have a diameter larger than that of the first drive gear 34, and is in mesh with the first drive gear 34.

[0059] The second drive gear 35B is formed with a smaller diameter than the first driven gear 35A and the second driven gear 36A, is positioned to the left of the first driven gear 35A, and is meshed with the second driven gear 36A.

[0060] The third drive gear 36B has a diameter that is approximately the same as that of the second driven gear 36A and smaller than that of the fourth-speed output gear 17D, and is disposed on the right side of the second driven gear 36A and meshes with the fourth-speed output gear 17D. In the meshing gear pair, the larger-diameter gear has more teeth than the smaller-diameter gear.

[0061] The reduction mechanism 33 reduces the driving force of the motor 32 and transmits it to the forward output shaft 12 by setting the diameters and number of teeth of the drive gears 34, 35B, 36B and the driven gears 35A, 36A, and the output gear 17D for the fourth gear to an arbitrary reduction ratio.

[0062] A pump shaft 52 of an oil pump 51 is connected to the reverse output shaft 13 via a one-way clutch 50, and the reverse output shaft 13 and the pump shaft 52 are installed on the same axis. The one-way clutch 50 of this embodiment constitutes a one-way clutch.

[0063] The oil pump 51 is configured, for example, as a trochoid pump, and is provided with a discharge port 51a for discharging lubricating oil and a suction port 51b for sucking in the lubricating oil.

[0064] The discharge port 51a is connected to the motor 32 via an oil pipe 53, and the intake port 51b is connected to an oil pan 55 via an oil pipe .

[0065] An inner rotor consisting of an external gear (not shown) is attached to the pump shaft 52. The inner rotor meshes with an outer rotor consisting of an internal gear (not shown), and when the pump shaft 52 rotates in one direction, the inner rotor and outer rotor mesh and rotate.

[0066] At this time, the oil pump 51 draws lubricating oil stored in the oil pan 55 from the oil piping 54 through the suction port 51b, and supplies the drawn lubricating oil from the discharge port 51a through the oil piping 53 to the motor 32. In this way, the motor 32 is cooled by the lubricating oil.

[0067] The lubricating oil flowing through the oil pipe 54 is cooled by an oil cooler (not shown). In this embodiment, the motor 32 constitutes a part requiring lubrication. Note that the part requiring lubrication is not limited to the motor 32, and may be any part that requires lubrication or cooling among the parts that constitute the transmission 1.

[0068] In this manner, the oil pump 51 is driven by the driving force transmitted from the reverse output shaft 13 to the pump shaft 52 .

[0069] When the vehicle is moving forward, the fourth synchronizer 21 is not connected to the reverse output shaft 13, so the reverse gear 22A rotates freely and the rotation from the reverse gear 22A is not transmitted to the reverse output shaft 13, but the rotation of the final driven gear 15A of the differential device 15 is transmitted to the reverse output shaft 13 via the final drive gear 22B.

[0070] Therefore, when the vehicle moves forward, the reverse output shaft 13 rotates in the opposite direction (direction A) to the final driven gear 15A, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the one-way clutch 50. This drives the oil pump 51 (rotates in direction A), and lubricating oil is discharged from the discharge port 51a of the oil pump 51.

[0071] One-way clutch 50 transmits only driving force in direction A to oil pump 51, and transmits driving force from reverse output shaft 13 to pump shaft 52 when reverse output shaft 13 rotates in direction A except when pump shaft 52 rotates at a faster rotational speed than reverse output shaft 13 in one direction (direction A) in which it rotates when the vehicle is moving forward, and does not transmit driving force from reverse output shaft 13 to pump shaft 52 when it rotates in the other direction. In other words, one-way clutch 50 does not transmit driving force from reverse output shaft 13 to pump shaft 52 when the vehicle is moving backward.

[0072] When the vehicle is traveling in reverse, the fourth synchronizer 21 connects the reverse gear 22A to the reverse output shaft 13. As a result, the reverse gear 22A rotates integrally with the reverse output shaft 13.

[0073] In the reverse position, the driving force of the engine 2 is transmitted from the input shaft 11 to the reverse output shaft 13 via the input gear 16A, the output gear 17A that rotates relative to the forward output shaft 12, and the reverse gear 22A, so that the reverse output shaft 13 rotates in the direction opposite to the direction of rotation when the vehicle is moving forward.

[0074] That is, the rotation direction of the reverse output shaft 13 changes depending on the traveling direction of the vehicle, and transmits driving force to the pump shaft 52 when the vehicle is traveling forward and when traveling backward. The reverse output shaft 13 in this embodiment constitutes a drive shaft.

[0075] A drive gear 56 made of a bevel gear is provided on the reverse output shaft 13. The drive gear 56 is fixed to the reverse output shaft 13 and rotates integrally with the reverse output shaft 13.

[0076] A driven gear 57 made of a bevel gear is provided on the pump shaft 52, and the driven gear 57 is formed to have the same shape as the drive gear 56. That is, the drive gear 56 and the driven gear 57 have the same diameter and the same number of teeth. The driven gear 57 is fixed to the pump shaft 52 and rotates integrally with the pump shaft 52. The driven gear 57 and the drive gear 56 are arranged opposite each other with the one-way clutch 50 in between.

[0077] An idler gear 58, which is a bevel gear, can mesh with the drive gear 56 and the driven gear 57. The driving force of the reverse output shaft 13 can be transmitted from the drive gear 56 to the pump shaft 52 via the idler gear 58 and the driven gear 57.

[0078] The idler gear 58 is movable by an actuator (not shown) between an engagement position (see Figure 2) where it engages with the drive gear 56 and the driven gear 57, and a non-engagement position (see Figure 1) where it does not engage with the drive gear 56 and the driven gear 57.

[0079] The actuator moves the idler gear 58 to an engaged position when the shift position is operated to the reverse position (R position), and moves the idler gear 58 to a non-engaged position when the shift position is operated to a position other than the reverse position.

[0080] The transmission 1 of this embodiment can be switched between a first state in which the pump shaft 52 and the reverse output shaft 13 are connected via the one-way clutch 50 and the driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the one-way clutch 50, and a second state in which the pump shaft 52 and the reverse output shaft 13 are connected via the idler gear 58 and the driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the idler gear 58.

[0081] Next, the operation will be described. When the vehicle is moving forward, the shift position is set to a position other than the reverse position, and therefore the idler gear 58 is set to a non-meshing position where it is not meshed with the drive gear 56 and the driven gear 57 by the actuator.

[0082] When the vehicle moves forward, reverse output shaft 13 rotates in one direction (direction A), and driving force is transmitted from reverse output shaft 13 to pump shaft 52 via one-way clutch 50, so that pump shaft 52 rotates in the same direction (direction A) as the rotation direction of reverse output shaft 13, and oil pump 51 is driven by pump shaft 52. At this time, oil pump 51 draws lubricating oil from oil piping 54 through suction port 51b and delivers the drawn lubricating oil to oil piping 53 from discharge port 51a.

[0083] That is, when the vehicle is moving forward, the oil pump structure of the transmission 1 is switched to a first state in which the pump shaft 52 and the reverse output shaft 13 are connected via the one-way clutch 50, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the one-way clutch 50.

[0084] In the first state, the lubricating oil is supplied to the motor 32 from the discharge port 51a through the oil pipe 53, and the motor 32 is cooled by the lubricating oil.

[0085] On the other hand, when the vehicle is moving backward, the shift position is in the reverse position, so that the actuator moves the idler gear 58 to a meshing position where it meshes with the drive gear 56 and the driven gear 57.

[0086] When the vehicle is driven in reverse, the reverse output shaft 13 rotates in the opposite direction to when the vehicle is driven forward, and the rotation of the reverse output shaft 13 is blocked by the one-way clutch 50 so that driving force is not transmitted to the pump shaft 52.

[0087] In the oil pump structure of transmission 1 of this embodiment, when the vehicle is moving backward, the driving force of reverse output shaft 13 is transmitted from drive gear 56 via idler gear 58 and driven gear 57 to pump shaft 52, and pump shaft 52 rotates in the same direction as the rotation direction when the vehicle is moving forward. In other words, when the vehicle is moving backward, reverse output shaft 13 rotates in the reverse direction (opposite direction A), but the rotation of reverse output shaft 13 is reversed and transmitted to pump shaft 52 via idler gear 58, so that pump shaft 52 rotates in the same direction as the rotation direction when the vehicle is moving forward (direction A).

[0088] In other words, when the vehicle is moving in reverse, the oil pump structure of the transmission 1 can be switched to a second state in which the pump shaft 52 and the reverse output shaft 13 are connected via the idler gear 58, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the idler gear 58.

[0089] Therefore, pump shaft 52 does not rotate in the direction opposite to the direction when the vehicle is moving forward, and lubricating oil is sucked from oil pipe 53 through discharge port 51a, preventing lubricating oil from being discharged from suction port 51b.

[0090] As a result, the lubricating oil can continue to flow in the same direction even when the vehicle is moving backward, and the lubricating oil can be reliably supplied to the motor 32 from the discharge port 51a through the oil piping 53, so that the motor 32 can be reliably cooled even when the vehicle is moving backward.

[0091] In this way, the oil pump structure of the transmission 1 of this embodiment can be switched between a first state in which the pump shaft 52 and the reverse output shaft 13 are connected via the one-way clutch 50 and the driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the one-way clutch 50, and a second state in which the pump shaft 52 and the reverse output shaft 13 are connected via the idler gear 58 and the driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the idler gear 58.

[0092] This allows lubricating oil to be supplied to the motor 32 from the discharge port 51a when the vehicle is moving forward and backward, even when the oil pump 51 is driven by driving force from the reverse output shaft 13, whose rotation direction changes depending on the direction of travel of the vehicle.

[0093] Furthermore, the oil pump structure of this embodiment does not require multiple check valves, and can supply lubricating oil to the motor 32 with a simple structure consisting of the one-way clutch 50, drive gear 56, driven gear 57, and idler gear 58, thereby providing a highly reliable oil pump structure.

[0094] Furthermore, since a check valve is not required, the oil pump 51 does not need to generate high-pressure oil pressure, and the driving force transmission efficiency of the transmission 1 can be prevented from deteriorating.

[0095] Furthermore, according to the oil pump structure of the transmission 1 of this embodiment, the idler gear 58 is a bevel gear, and the pump shaft 52 and the reverse output shaft 13 are provided with a drive gear 56 and a driven gear 57, each of which is also a bevel gear that can mesh with the idler gear 58.

[0096] This allows the rotation direction of the pump shaft 52 when the vehicle is moving backward to be changed to the same direction as when the vehicle is moving forward by the drive gear 56, driven gear 57 and idler gear 58 without using a hydraulic circuit or hydraulic device.

[0097] (Second Example) 3 to 5 are diagrams showing an oil pump structure for a vehicle transmission according to a second embodiment of the present invention, and the same components as those in the first embodiment are given the same reference numerals and their explanations will be omitted.

[0098] 3 to 5, the reverse output shaft 13 is provided with a first drive gear 61, a second drive gear 62, and a hub gear 63 of a switching device.

[0099] The first drive gear 61 and the second drive gear 62 are rotatable relative to the reverse output shaft 13 , and the hub gear 63 rotates integrally with the reverse output shaft 13 .

[0100] The pump shaft 52 is provided with a first pump gear 64 and a second pump gear 65 , and the first pump gear 64 and the second pump gear 65 rotate integrally with the pump shaft 52 .

[0101] The first drive gear 61 meshes with the first pump gear 64 and has a smaller diameter than the first pump gear 64 .

[0102] The transmission 1 is provided with an idler shaft 66, which is disposed in parallel to the reverse output shaft 13 and the pump shaft 52. The reverse output shaft 13 and the pump shaft 52 are also disposed in parallel.

[0103] An idler gear 67 is provided on the idler shaft 66, and the idler gear 67 is rotatable relative to the idler shaft 66. As shown in Fig. 4, the idler gear 67 is provided with a fork groove 67a with which a shift fork (not shown) engages.

[0104] The idler gear 67 is provided so as to be movable along the axis of the idler shaft 66 by a shift fork that engages with the fork groove 67a.

[0105] The reverse output shaft 13 is provided with a sleeve 68 that, together with the hub gear 63, constitutes a switching mechanism. The sleeve 68 is movable in the axial direction of the reverse output shaft 13.

[0106] A fork groove 68a is formed on the outer periphery of the sleeve 68, and a shift fork (not shown) is engaged with the fork groove 68a. The sleeve 68 moves in the axial direction of the reverse output shaft 13 by the shift fork engaging with the fork groove 68a.

[0107] The amount of movement at the time of switching is set so that the idler gear 67 and sleeve 68 move integrally in the axial direction of the reverse output shaft 13 and the idler shaft 66, which simplifies the configuration of the switching operating members.

[0108] An inner peripheral spline 68b is formed on the inner peripheral surface of the sleeve 68. Dog gears 61a and 62a are provided on the first drive gear 61 and the second drive gear 62, and the inner peripheral spline 68b of the sleeve 68 can mesh with the dog gears 61a and 62a.

[0109] The sleeve 68 can be freely moved by an actuator (not shown) between a forward meshing position (see Figures 3 and 4) where it meshes with the dog gear 61a of the first drive gear 61 and the hub gear 63, and a reverse meshing position (see Figure 5) where it meshes with the dog gear 62a of the second drive gear 62 and the hub gear 63.

[0110] The actuator moves the sleeve 68 to a reverse engagement position when the shift position is operated to the reverse position, and moves the sleeve 68 to a forward engagement position when the shift position is operated to a position other than the reverse position.

[0111] That is, the oil pump structure of the transmission 1 of this embodiment can be switched between a first state in which the reverse output shaft 13 and the pump shaft 52 are connected by the first drive gear 61 and the first pump gear 64, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the first drive gear 61 and the first pump gear 64, and a second state in which the reverse output shaft 13 and the pump shaft 52 are connected by the second drive gear 62, the idler gear 67, and the second pump gear 65, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the second drive gear 62, the idler gear 67, and the second pump gear 65.

[0112] Next, the operation will be described. When the vehicle is traveling forward, the shift position is set to a position other than the reverse position, and therefore the sleeve 68 is set to a forward meshing position where it meshes with the dog gear 61a of the first drive gear 61 and the hub gear 63. This connects the first drive gear 61 to the reverse output shaft 13 and allows it to rotate integrally with the reverse output shaft 13.

[0113] When the vehicle moves forward, the reverse output shaft 13 rotates in one direction, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the first drive gear 61 and the first pump gear 64 .

[0114] As a result, the oil pump 51 is driven by the pump shaft 52 , the pump shaft 52 rotates in the direction opposite to the direction of rotation of the reverse output shaft 13 , and the oil pump 51 is driven by the pump shaft 52 .

[0115] That is, when the vehicle is moving forward, the oil pump structure of the transmission 1 is switched to a first state in which the reverse output shaft 13 and the pump shaft 52 are connected by the first drive gear 61 and the first pump gear 64, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the first drive gear 61 and the first pump gear 64.

[0116] In the first state, the lubricating oil is supplied to the motor 32 from the discharge port 51a through the oil pipe 53, and the motor 32 is cooled by the lubricating oil.

[0117] On the other hand, when the vehicle is moving backward, the shift position is in the reverse position, so the actuator moves the sleeve 68 to a reverse engagement position where the sleeve 68 meshes with the dog gear 62a of the second drive gear 62 and the hub gear 63. As a result, the second drive gear 62 is connected to the reverse output shaft 13 and can rotate integrally with the reverse output shaft 13.

[0118] When the vehicle is traveling backward, the reverse output shaft 13 rotates in the opposite direction to when the vehicle is traveling forward. In the oil pump structure of the transmission 1 of this embodiment, when the vehicle is traveling in reverse, the driving force of the reverse output shaft 13 is transmitted to the pump shaft 52 via the second drive gear 62, the idler gear 67, and the second pump gear 65, and the pump shaft 52 rotates in the same direction as when the vehicle is traveling forward.

[0119] In other words, when the vehicle is moving in reverse, the oil pump structure of the transmission 1 connects the reverse output shaft 13 and the pump shaft 52 via the second drive gear 62, the idler gear 67, and the second pump gear 65, and can be switched to a second state in which driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the second drive gear 62, the idler gear 67, and the second pump gear 65.

[0120] This prevents the pump shaft 52 from rotating in the direction opposite to the direction when the vehicle is moving forward, and prevents the lubricating oil from being drawn from the oil pipe 53 through the discharge port 51a and discharged from the suction port 51b.

[0121] As a result, lubricating oil can be reliably supplied from the discharge port 51a through the oil pipe 53 to the motor 32, and the motor 32 can be reliably cooled when the vehicle is moving backward.

[0122] In this way, the oil pump structure of the transmission 1 of this embodiment can be switched between a first state in which the reverse output shaft 13 and the pump shaft 52 are connected by the first drive gear 61 and the first pump gear 64, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the first drive gear 61 and the first pump gear 64, and a second state in which the reverse output shaft 13 and the pump shaft 52 are connected by the second drive gear 62, the idler gear 67, and the second pump gear 65, and driving force is transmitted from the reverse output shaft 13 to the pump shaft 52 via the second drive gear 62, the idler gear 67, and the second pump gear 65.

[0123] This allows lubricating oil to be supplied to the motor 32 from the discharge port 51a when the vehicle is moving forward and backward, even when driving force is transmitted to the oil pump 51 from the reverse output shaft 13, whose rotation direction changes depending on the direction of travel of the vehicle.

[0124] Furthermore, the oil pump structure of this embodiment does not require a large number of check valves, and the motor 32 can be lubricated by a simple gear structure consisting of the first drive gear 61, the second drive gear 62, the hub gear 63, the first pump gear 64, the second pump gear 65, the idler gear 67, and the sleeve 68, resulting in a highly reliable oil pump structure.

[0125] Furthermore, since a check valve is not required, there is no need to ensure a relatively high hydraulic pressure, and the driving force transmission efficiency of the transmission 1 can be prevented from deteriorating.

[0126] Furthermore, according to the oil pump structure of the transmission 1 of this embodiment, the idler gear 67 can be switched between a state in which it meshes with the second drive gear 62 and the second pump gear 65 and a state in which it does not mesh with the second drive gear 62 and the second pump gear 65.

[0127] As a result, the rotation direction of the pump shaft 52 when the vehicle is moving backward can be changed to the same direction as the rotation direction when the vehicle is moving forward, by engaging and disengaging the idler gear 67 with the second drive gear 62 and the second pump gear 65.

[0128] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0129] 1...transmission (vehicle transmission), 13...reverse output shaft (drive shaft), 32...motor, 50...one-way clutch (one-way clutch), 51...oil pump, 51a...discharge port, 51b...suction port, 52...pump shaft, 56...drive gear (bevel gear), 57...driven gear (bevel gear), 58, 67...idler gear, 61...first drive gear, 62...second drive gear, 64...first pump gear, 65...second pump gear

Claims

[Claim 1] an oil pump having a discharge port for discharging lubricating oil and a suction port for drawing lubricating oil, the oil pump being driven by a pump shaft; a drive shaft whose rotation direction is changed according to the traveling direction of the vehicle and which transmits driving force to the pump shaft, The pump shaft and the drive shaft are installed on the same axis, an idler gear consisting of a bevel gear; The pump shaft and the drive shaft are each provided with a bevel gear that can mesh with the idler gear, An oil pump structure for a vehicle transmission, characterized in that it is switchable between a first state in which the pump shaft and the drive shaft are connected via a one-way clutch and driving force is transmitted from the drive shaft to the pump shaft via the one-way clutch, and a second state in which the pump shaft and the drive shaft are connected via the idler gear and driving force is transmitted from the drive shaft to the pump shaft via the idler gear.

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