Vehicle power transmission device

Abstract

To provide a vehicle power transmission device capable of downsizing the entire device.SOLUTION: A power transmission device 1 is for a vehicle Ve which comprises a torque converter 3 made up of: a pump impeller 11 to which torque is transmitted from a drive power source 2; a turbine runner 12 which is arranged opposite the pump impeller 11; a stator 14 which is installed between the pump impeller 11 and the turbine runner 12 on a predetermined fixed shaft 18 through a one-way clutch 13; and a cover 16 which oil-tightly covers an outer periphery side of the turbine runner 12. A hollow input shaft 15 transmitting torque from the drive power source 2 to the pump impeller 11 is extended in a direction from the pump impeller 11 to an opposite side of the turbine runner 12. The fixed shaft 18 is formed as a hollow shaft and axially extended through an interior of the input shaft 15. An output shaft 19 connected to the turbine runner 12 is arranged to be axially extended through an interior of the fixed shaft 18.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power transmission device for a vehicle equipped with a torque converter for amplifying the torque of a power source and transmitting it to wheels.

Background Art

[0002] Patent Document 1 discloses a drive unit aimed at improving braking force during deceleration. The drive unit described in Patent Document 1 includes a motor, a torque converter connected to the motor, an input shaft connected to the impeller of the torque converter, an output shaft connected to the turbine of the torque converter, and a planetary gear mechanism connected to the output shaft of the torque converter. In the drive unit of Patent Document 1, the output shaft of the motor is connected to the input shaft of the torque converter. The output shaft of the torque converter is arranged on the outer peripheral side of the input shaft of the torque converter and on the same axis as the input shaft of the torque converter. The stator of the torque converter is connected to a fixed shaft via a one-way clutch. The fixed shaft is a cylindrical member connected to the case, and the input shaft and output shaft of the torque converter penetrate through the inside of the fixed shaft. Further, a sleeve portion for rotatably supporting the impeller is arranged on the outer peripheral side of the fixed shaft. That is, the fixed shaft, the output shaft of the torque converter, and the input shaft of the torque converter penetrate through the inner peripheral side of the sleeve portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The drive unit of Patent Document 1 has a so-called four-axis structure in which a sleeve portion, a fixed shaft, an output shaft, and an input shaft are arranged on the inner peripheral side of the torque converter. Therefore, the sleeve portion, the fixed shaft, the output shaft, and the input shaft are arranged so as not to interfere with each other in the radial direction, or bearings are provided. That is, due to the so-called four-axis structure of the drive unit of Patent Document 1, it is inevitably necessary to increase the diameter in the radial direction. Therefore, there is still room for improvement in order to miniaturize the structure of the entire unit including the torque converter in the radial direction.

[0005] This invention has been made paying attention to the above technical problem, and an object thereof is to provide a power transmission device for a vehicle capable of miniaturizing the entire device.

Means for Solving the Problems

[0006] In order to achieve the above object, this invention provides a power transmission device for a vehicle having a torque converter including a pump impeller that rotates by transmitting torque from a driving power source, a turbine runner arranged to face the pump impeller, a stator that is attached to a predetermined fixed shaft via a one-way clutch between the pump impeller and the turbine runner and controls the flow of oil from the turbine runner toward the pump impeller, and a cover that extends from the outer peripheral portion of the pump impeller toward the turbine runner side and covers the outer peripheral side of the turbine runner in an oil-tight state. A hollow input shaft that transmits torque from the driving power source to the pump impeller extends from the pump impeller toward the side opposite to the turbine runner, the predetermined fixed shaft is a hollow shaft, and the predetermined fixed shaft is arranged to penetrate the inside of the input shaft in the axial direction, and an output shaft connected to the turbine runner penetrates the inside of the fixed shaft in the axial direction.

Effects of the Invention

[0007] The power transmission device of the vehicle in this invention includes an output shaft to which the output torque of the torque converter is transmitted, a hollow predetermined fixed shaft that supports the stator of the torque converter, and a hollow input shaft that transmits torque from a driving power source to the pump impeller. The input shaft is provided to extend from the pump impeller toward the side opposite to the turbine runner, and the fixed shaft and the output shaft penetrate through the inside of the input shaft. Specifically, inside the input shaft, an output shaft that transmits the torque from the turbine runner to the outside penetrates in the axial direction and extends to the input shaft side, and a fixed shaft that penetrates axially between the output shaft and the input shaft is arranged. Eventually, it has a so-called three-shaft structure as a whole. Therefore, the input shaft and a predetermined shaft that rotatably supports the pump impeller are configured separately. For example, compared with the case where the input shaft of the torque converter is arranged penetrating the fixed shaft, the number of shaft-like members arranged overlapping in the radial direction can be reduced. Therefore, the overall configuration of the device can be miniaturized in the radial direction.

Brief Description of the Drawings

[0008]

Figure 1

Embodiments for Carrying Out the Invention

[0009] Hereinafter, this invention will be described based on the embodiments shown in the drawings. Note that the embodiments described below are merely examples when this invention is embodied, and do not limit this invention.

[0010] FIG. 1 shows an example of the configuration of a vehicle Ve equipped with the power transmission device 1 in an embodiment of this invention. The vehicle shown in FIG. 1 mainly includes a motor 2, a torque converter 3, a lock-up clutch 4, a first gear pair 5, a second gear pair 6, and a third gear pair 7. The vehicle has a unit in which the motor 2, an inverter (not shown), and a transaxle (not shown) are integrated, and is an electric vehicle configured with the motor 2 as the main driving power source.

[0011] The motor 2 is a motor - generator that outputs torque for driving the vehicle and has a function as a generator capable of generating electricity for energy regeneration. The motor 2 is, for example, an inner - rotor type motor, and is a three - phase alternating - current type motor in which a rotor (not shown) that rotates by magnetic force is arranged at a predetermined interval in the radial direction inside a stator (not shown) having a plurality of pairs of magnetic poles. The output shaft 8 of the motor 2 is connected to the input - side gear 5a of the first gear pair 5. Also, both ends of the output shaft 8 of the motor 2 in the axial direction are rotatably supported by bearings 9 and 10 with respect to a fixed member (not shown) such as a case. The output shaft 8 of the motor 2 is connected to the torque converter 3 via the first gear pair 5.

[0012] The torque converter 3 is configured in the same manner as a conventional torque converter 3, amplifies the torque of the motor 2, and transmits it to the second gear pair 6 side. That is, the torque converter 3 includes a pump impeller 11 connected to the output shaft 8 of the motor 2, a turbine runner 12 arranged opposite to the pump impeller 11, a stator 14 arranged between the pump impeller 11 and the turbine runner 12 and connected to a fixed member such as a case via a one - way clutch (non - reversible clutch) 13, and an outer shell portion 16 that extends from the outer peripheral portion of the pump impeller toward the turbine runner side and covers the outer peripheral side of the turbine runner in an oil - tight state. The torque converter 3 is configured such that, by receiving the fluid flow generated by the rotation of the pump impeller 11, torque is transmitted when the turbine runner 12 rotates. Also, the stator 14 is configured to change or maintain the flow direction of the oil according to the speed ratio between the pump impeller 11 and the turbine runner 12. Note that the outer shell portion 16 corresponds to the cover in the embodiment of this invention.

[0013] The pump impeller 11 is integrally formed with a hollow sleeve shaft 15. The sleeve shaft 15 extends from the pump impeller 11 toward the motor 2 side, that is, the side opposite to the turbine runner 12. At the end of the sleeve shaft 15 on the motor 2 side, an output side gear 5b of the first gear pair 5 is formed. That is, the torque of the motor 2 is input to the torque converter 3 via the first gear pair 5 and the sleeve shaft 15. Further, the pump impeller 11 is provided with an outer peripheral portion 16 integrally formed on the outer peripheral side of the pump impeller 11. The outer peripheral portion 16 covers the turbine runner 12 and the lock-up clutch 4 and is provided so as to accommodate the turbine runner 12 and the lock-up clutch 4. Further, on the inner surface of the outer peripheral portion 16, a member on the input side of the lock-up clutch 4 is integrally formed. The sleeve shaft 15 is rotatably supported by a bearing 17 on a fixing member such as a case. The sleeve shaft 15 corresponds to the input shaft in the embodiment of the present invention.

[0014] The stator 14 is configured to control the flow of oil from the turbine runner 12 toward the pump impeller 11, and is connected to a hollow stator shaft 18 that axially penetrates the inside of the sleeve shaft 15. The stator shaft 18 is formed in a cylindrical shape and is arranged on the same rotation axis as the sleeve shaft 15. The stator shaft 18 is formed longer than the sleeve shaft 15, and a one-way clutch 13 is attached to the end of the stator shaft 18 on the side opposite to the stator 14 in the axial direction. The stator shaft 18 corresponds to a predetermined fixed shaft in the embodiment of the present invention.

[0015] The turbine runner 12 is integrally formed with the member on the output side of the lock-up clutch 4. Specifically, a shaft member formed on the inner peripheral side of the turbine runner 12 is connected to the member on the output side of the lock-up clutch 4. Further, the output shaft 19 of the torque converter 3 is connected to the turbine runner 12 via the member on the output side of the lock-up clutch 4. The output shaft 19 of the torque converter 3 is arranged on the same rotation axis as the sleeve shaft 15 and the stator shaft 18, and is provided so as to axially penetrate the inside of the stator shaft 18. Note that the output shaft 19 of the torque converter 3 corresponds to the rotation shaft in the embodiment of the present invention.

[0016] The lock-up clutch 4 is configured in the same manner as a conventional lock-up clutch 4, and can selectively transmit the output torque of the motor 2 to the second gear pair 6 without amplification by the torque converter 3. Specifically, the lock-up clutch 4 engages, disengages, or slips the input-side member and the output-side member by a friction multi-plate clutch. That is, the rotational speed difference between the pump impeller 11 connected to the input-side member and the turbine runner 12 connected to the output-side member can be appropriately changed.

[0017] Further, the engagement and disengagement of the lock-up clutch 4 are performed by controlling the hydraulic pressure. The control of the hydraulic pressure is performed by the valve body 20 and the oil pump 21. The valve body 20 and the oil pump 21 are provided on the side opposite to the torque converter 3 of the lock-up clutch 4 in the axial direction as shown in FIG. 1. By controlling the oil discharged from the oil pump 21 by the valve body 20, the amount of oil supplied to the lock-up clutch 4 is adjusted. Thereby, the lock-up clutch 4 is controlled to be in any one of the above-described engaged, disengaged, and slip-engaged states.

[0018] Also, as described above, the member on the output side of the lock-up clutch 4 is integrated with the turbine runner 12, and the output shaft 19 of the torque converter 3 is integrally rotatably connected to the member on the output side thereof. The output shaft 19 of the torque converter 3 is formed longer in the axial direction than the sleeve shaft 15 and the stator shaft 18. A bearing 22 is provided at the end of the stator shaft 18 on the side opposite to the torque converter 3 with the one-way clutch 13 interposed therebetween. The bearing 21 rotatably supports the stator shaft 18 with respect to a fixed member such as a case. Further, the end of the output shaft 19 of the torque converter 3 on the side opposite to the lock-up clutch 4 in the axial direction is rotatably supported by a fixed member such as a case via a bearing 23.

[0019] The second gear pair 6 is disposed axially between the motor 2 and the torque converter 3. The input-side gear 6a of the second gear pair 6 is connected to the output shaft 19 of the torque converter 3, and the torque of the torque converter 3 is input thereto. Also, the output-side gear 6b of the second gear pair 6 is connected to a rotating shaft 24 connected to the input-side gear 7a of the third gear pair 7. That is, the torque of the torque converter 3 is input to the third gear pair 7 via the second gear pair 6 and the rotating shaft 24. Both ends of the rotating shaft 24 in the axial direction are rotatably supported by a fixed member such as a case via bearings 25 and 26, respectively. Note that the second gear pair 6 may be configured as a speed reducer.

[0020] The third gear pair 7 is disposed radially beside the motor 2. The third gear pair 7 functions as a speed reducer that amplifies the torque input from the second gear pair 6 and transmits it to the output side. Although not shown, wheels are connected to the output-side gear 7b of the third gear pair 7 via a shaft member and a differential gear unit or the like. Both ends of the shaft member in the axial direction are rotatably supported by a fixed member such as a case via bearings 27 and 28, respectively, as shown in FIG. 1.

[0021] As described above, the power transmission device 1 in the embodiment of the present invention is configured such that the output torque of the motor 2 is transmitted to the wheels via the torque converter 3. Outside the output shaft 19 of the torque converter 3, a hollow stator shaft 18 for supporting the stator 14 of the torque converter 3 is arranged. Further, outside the stator shaft 18, a hollow sleeve shaft 15 integrated with the pump impeller 11 is arranged. The output shaft 8 of the motor 2 is connected to the sleeve shaft 15 via the first gear pair 5. That is, on the same rotation axis, the output shaft 19 of the torque converter 3 and the stator shaft 18 are arranged inside the sleeve shaft 15. That is, as a whole, it has a so-called three-shaft structure. And the sleeve shaft 15 functions as an input shaft for transmitting the output torque of the motor 2 to the torque converter 3. That is, the sleeve shaft 15 and the input shaft of the torque converter 3 are shared.

[0022] Therefore, for example, when the sleeve shaft 15 and the input shaft of the torque converter 3 are separately configured and one of the shafts of the sleeve shaft 15 and the input shaft of the torque converter 3 penetrates axially inside the other shaft, the overall configuration of the device can be miniaturized in the radial direction compared to this case. By utilizing the space generated thereby, it becomes possible to increase the outer diameter of the output-side gear 6b of the second gear pair 6 and the output-side gear 7b of the third gear pair 7 to increase the reduction ratio. And since the sleeve shaft 15 and the input shaft of the torque converter 3 are shared, the number of rotating shaft members can be reduced, so that the number of bearings of the entire device can be reduced.

[0023] Also, due to such a configuration, the first gear pair 5 for inputting the output torque of the motor 2 to the torque converter 3 can be disposed on the outer peripheral side of the stator shaft 18. For example, when the input shaft of the torque converter 3 and the sleeve shaft 15 are arranged to overlap on the same rotation axis, the first gear pair 5 may be arranged side by side in the axial direction with the output shaft 19 of the torque converter 3 or the sleeve shaft 15 or the like. Compared with such a case, the apparatus as a whole can be miniaturized in the axial direction. Therefore, by utilizing the space generated in the axial direction, the valve body 20 and the oil pump 21 can be arranged on the side opposite to the torque converter 3 with the lock-up clutch 4 interposed therebetween. Thereby, the total length of the oil passage from the valve body 20 and the oil pump 21 to the lock-up clutch 4 can be made relatively short. Note that the valve body 20 is attached to a cover (not shown) that covers the torque converter 3 and controls the oil discharged by the oil pump 21. The oil pump 21 is connected to the outer peripheral portion 16 and is a mechanical oil pump 21 that discharges oil when the torque of the motor 2 is input.

[0024] Furthermore, the first gear pair 5 is disposed closer to the torque converter 3 than the one-way clutch 13 in the axial direction. Therefore, the one-way clutch 13 can be arranged at a position different from that of the sleeve shaft 15 in the axial direction. Accordingly, by integrating the output-side gear 5b of the first gear pair 5 with the sleeve shaft 15, an increase in the diameter of the stator shaft 18 can be suppressed.

Explanation of Reference Numerals

[0025] 1 Power transmission device 2 Motor (driving power source) 3 Torque converter 5 First gear pair (gear pair) 8 Output shaft 11 Pump impeller 12 Turbine runner 13 One-way clutch 14 Stator 15 Sleeve shaft (input shaft of torque converter) 16 Outer shell (cover) 18 Stator shaft (predetermined fixed shaft) 19 Output shaft Ve Vehicle

Claims

【Claim 1】 A power transmission device for a vehicle having a torque converter comprising a pump impeller that rotates by receiving torque from a power source, a turbine runner disposed opposite to the pump impeller, a stator that is attached via a one-way clutch to a predetermined fixed shaft between the pump impeller and the turbine runner and controls the flow of oil from the turbine runner toward the pump impeller, and a cover that extends from an outer peripheral portion of the pump impeller toward the turbine runner side and covers the outer peripheral side of the turbine runner in an oil-tight manner, a hollow input shaft for transmitting torque from the power source to the pump impeller is provided to extend from the pump impeller toward the side opposite to the turbine runner, the predetermined fixed shaft is a hollow shaft and is disposed in a state of axially penetrating the inside of the input shaft, and an output shaft connected to the turbine runner is disposed to axially penetrate the inside of the fixed shaft. A power transmission device for a vehicle, characterized by the above.

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