JP2017001502A - Hybrid-vehicular power transmission apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid-vehicular power transmission apparatus capable of improving NV performance by improving configurations of a damper mechanism and a torque limiter.SOLUTION: A hybrid-vehicular power transmission apparatus have: a damper mechanism 10 for absorbing a torsional vibration with elasticity of a damper spring 10a; a torque limiter 12 for limiting transmission torque between an engine and a drive shaft; a sun gear 6 of a planetary gear mechanism 4 connected to a first motor 2; a ring gear 7 connected to counter gears 16, 17 and a drive shaft 5 via a first drive gear 14 that is meshed with the counter gear 16; and a carrier 8 connected to the engine 1 via the damper mechanism 10. Further in the apparatus, the ring gear 7 and the first drive gear 14 are separately disposed and connected integrally via the torque limiter 12, and the damper spring 10a is disposed on an at-most outer circumference of the damper mechanism 10 and in a direction of the spring expanding-compressing in the circumferential direction of the damper mechanism 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power transmission device for a hybrid vehicle that transmits torque output from a driving force source to a driving shaft, and in particular, a damper mechanism that absorbs vibration of the driving force source and torsional vibration of the transmission shaft, and power transmission. The present invention relates to a power transmission device for a hybrid vehicle including a torque limiter that prevents overload on the device.

  Patent Document 1 describes a power transmission device for a hybrid vehicle that uses an engine and a first motor and a second motor as driving force sources, and includes a damper mechanism with a torque limiter. In the power transmission device described in Patent Document 1, the engine and the first motor are connected to the drive shaft via a power split mechanism and a gear train configured by a planetary gear mechanism, and the second motor has a gear train. Via the drive shaft. Specifically, the first motor is connected to the sun gear of the planetary gear mechanism, and the engine is connected to the carrier. A counter drive gear is integrally formed on the outer periphery of the ring gear, and a second motor and a drive shaft are connected to the counter drive gear via a gear train. A damper mechanism is provided along with the flywheel between the engine crankshaft and the input shaft of the power split mechanism. This damper mechanism is composed of a damper part and a torque limiter part. The damper part is a mechanism that buffers and absorbs torque fluctuations with respect to the flywheel fixed to the crankshaft of the engine. The torque limiter unit is a mechanism that limits power transmission from the crankshaft to the input shaft of the power split mechanism when the fluctuation torque between the damper unit and the flywheel reaches a predetermined value (limit torque).

  Patent Document 2 describes a hybrid vehicle drive device including a planetary gear mechanism (power split mechanism), a one-way clutch, and a torque limiter. In the hybrid vehicle drive device described in Patent Document 2, the first motor is connected to the sun gear of the planetary gear mechanism, the engine is connected to the carrier, and the second motor and the drive wheels are connected to the ring gear. The ring gear is disposed on the inner peripheral side of the hollow rotating body and is connected to the drive wheels via a counter drive gear formed on the outer peripheral side of the rotating body. The one-way clutch is configured to regulate the rotation of the carrier in the negative direction when the rotation direction of the ring gear during forward traveling of the hybrid vehicle is a positive direction. The torque limiter operates in accordance with the transmission torque of the one-way clutch and is configured to limit the transmission torque of the one-way clutch. The one-way clutch and the torque limiter are disposed inside the rotating body. The torque limiter is provided between the first motor and the sun gear.

  Patent Document 3 describes a power transmission device for a hybrid vehicle including a planetary gear mechanism (power split mechanism) and a damper mechanism having a torque limiter. In the power transmission device described in Patent Document 3, the first motor is connected to the sun gear of the planetary gear mechanism, the engine is connected to the carrier, and the output shaft of the power split mechanism is connected to the ring gear. The output shaft is connected to the drive wheel via a differential gear. A second motor is connected to the output shaft via an automatic transmission constituted by a Ravigneaux planetary gear mechanism. The damper mechanism and the torque limiter are provided between the first motor and the sun gear.

JP 2012-137115 A Japanese Patent No. 5252122 JP 2010-162969 A

  As described above, the damper mechanism in the power transmission device described in Patent Document 1 includes the damper portion and the torque limiter portion. The damper part mainly includes a hub connected to the input shaft by a spline, a side plate relatively rotatable with the hub, an annular disk to which a friction material is fixed and arranged on the outer peripheral side of the side plate, and the hub and the side. It is comprised from the coil spring etc. which are accommodated in the position which a plate opposes. The torque limiter part is mainly composed of a plate fixed to the flywheel, a friction plate for sandwiching the disk of the damper part together with the plate, a spring spring for biasing the friction plate toward the plate side, and the like. And the torque limiter part is arrange | positioned at the outer peripheral side of said damper part.

  By using such a damper mechanism, it is possible to suppress noise and vibration caused by torque fluctuation transmitted to the power transmission device. That is, the NV performance of the vehicle can be improved. In order to further improve the NV performance of the vehicle by the damper mechanism as described above, it is effective to reduce the spring of the damper mechanism. Specifically, it is effective to reduce the spring constant of the coil spring of the damper mechanism. For example, by arranging the coil spring on the outer peripheral side of the side plate with a large space, the total length (free height) of the coil spring can be lengthened and the spring constant can be lowered. As a result, the damper mechanism can be lowered. can do. However, in the damper mechanism in the power transmission device described in Patent Document 1 above, since the torque limiter is provided on the outer peripheral side of the damper portion, that is, the coil spring, the coil spring is arranged closer to the outer peripheral side of the side plate than the current state. Can not do it. Therefore, it is difficult to lengthen the overall length of the coil spring and reduce the spring of the damper mechanism.

  On the other hand, as in the configurations described in Patent Literature 2 and Patent Literature 3 described above, for example, by arranging a torque limiter between the planetary gear mechanism in the power transmission device and the first motor, A space for arranging the coil spring in the outer peripheral portion is created. By arranging the coil spring in a portion where the space of the outer peripheral portion of the side plate is wide, the overall length of the coil spring can be increased. However, when the torque limiter is disposed between the planetary gear mechanism and the first motor as described above, torque is directly transmitted from the drive shaft side to the power transmission device without passing through the torque limiter. For example, the torque input from the wheels due to road surface disturbance or the like may be the maximum input to the power transmission device. However, in the arrangement of the torque limiter as described above, the power for such road surface input The gear system of the transmission device cannot be properly protected.

  The present invention has been conceived by paying attention to the above technical problems, and provides a power transmission device for a hybrid vehicle capable of improving NV performance by improving the configurations of a damper mechanism and a torque limiter. It is for the purpose.

  In order to achieve the above object, the present invention provides a planetary gear mechanism having an engine and a first motor and a second motor as driving force sources, and arranged on the same axis as the rotation shaft of the engine and the first motor. A counter shaft disposed in parallel with the rotation shaft, a counter gear attached to the counter shaft for transmitting power to the drive shaft, and an elasticity of a damper spring between the engine and the planetary gear mechanism. A damper mechanism that absorbs torsional vibration; and a torque limiter that limits a torque transmitted between the engine and the drive shaft; a sun gear of the planetary gear mechanism is connected to the first motor; A first drive gear meshing with a counter gear is connected to the drive shaft via the counter gear, and a carrier is moved forward via the damper mechanism. In a power transmission device for a hybrid vehicle connected to an engine and connected to the drive shaft via the counter gear and a second drive gear in which the second motor meshes with the counter gear, the ring gear and the first drive gear Are configured as separate bodies and integrally connected via the torque limiter, and the damper spring is disposed in the direction of extending and contracting in the circumferential direction of the damper mechanism on the outermost peripheral side of the damper mechanism. It is characterized by being.

  The present invention also includes a cylindrical portion having a pair of bearings for supporting both end portions of the rotation shaft of the first drive gear, and wherein the first drive gear is formed with an external gear that meshes with the counter gear on an outer peripheral portion. The ring gear and the torque limiter are arranged in series in the axial direction of the counter shaft between the pair of bearings at the inner peripheral portion of the cylindrical portion. .

  The present invention is characterized in that an annular mass body for increasing the moment of inertia of the first drive gear is attached to the outer peripheral portion of the cylindrical portion.

  According to the present invention, in the power transmission device for a hybrid vehicle, the ring gear of the planetary gear mechanism that functions as a so-called power split mechanism, and the first drive gear for transmitting torque from the ring gear to the drive shaft via the counter gear, Are formed separately. The ring gear and the first drive gear are integrally connected via a torque limiter. Therefore, if the torque transmitted between the ring gear and the first drive gear is smaller than the torque limited by the torque limiter, the ring gear and the first drive gear rotate together, and the ring gear, the counter gear, and the drive shaft Torque is transmitted between them. On the other hand, when the torque transmitted between the ring gear and the first drive gear exceeds the torque limited by the torque limiter, the torque limiter operates to transmit power between the ring gear, the counter gear, and the drive shaft. Is cut off. Therefore, for example, even when an excessive torque due to road surface disturbance or the like is input from the wheel side to the power transmission device, the gear system of the power transmission device is appropriately protected by the torque limiter arranged as described above. can do.

  Furthermore, by arranging the torque limiter between the ring gear and the first drive gear as described above, a space is formed on the outer peripheral side of the damper spring of the damper mechanism in which the torque limiter has been conventionally arranged. Therefore, the arrangement position of the damper spring can be moved from the inner circumference side of the damper mechanism having a narrow space to the outer circumference side having a large space, and the damper spring can be arranged on the outermost circumference side of the damper mechanism. Therefore, according to this invention, a damper spring is arrange | positioned in the outermost periphery side of a damper mechanism, ie, the part where the space of the outer periphery side is possible as much as possible. Therefore, the overall length of the damper spring can be made as long as possible. As a result, the spring of the damper mechanism can be lowered, that is, the spring constant of the damper spring can be lowered to increase the effect of suppressing torsional vibration, and the NV performance of the hybrid vehicle can be improved.

  According to the present invention, the hollow portion is formed in the inner peripheral portion of the first drive gear which is an external gear, and the ring gear and the torque limiter are arranged in the hollow portion. Therefore, for example, by forming the hollow portion, that is, the inner peripheral portion of the cylindrical portion of the first drive gear, and the outer peripheral portion of the ring gear and the torque limiter, in a wax structure, positioning of the first drive gear, the ring gear and the torque limiter Can be made easier. Further, the ring gear and the torque limiter are disposed on the inner peripheral portion of the first drive gear as described above, and are disposed between the two bearings that support both end portions of the rotation shaft of the first drive gear. . Therefore, the ring gear and the torque limiter can be assembled with high accuracy in a portion where both ends are supported and the rigidity is high. Therefore, the support rigidity of each component can be increased and the occurrence of vibration and deformation can be suppressed. As a result, the NV performance of the hybrid vehicle can be improved.

  According to the present invention, the mass body is attached to the first drive gear, and the inertia moment of the first drive gear is increased. In the power transmission device according to the present invention, it has been found that, particularly, by increasing the moment of inertia of the first drive gear, the damping effect of vibration transmitted from the engine to the drive shaft side can be enhanced. Therefore, the NV performance of the hybrid vehicle can be improved by attaching the mass body to the first drive gear as described above.

It is a figure which shows an example of the drive train of the hybrid vehicle to which the power transmission device of this invention is applied. It is sectional drawing for demonstrating an example of a structure of the power transmission device of the hybrid vehicle of this invention. It is sectional drawing for demonstrating the other structural example of the power transmission device of the hybrid vehicle of this invention.

  The present invention will be specifically described with reference to the drawings. First, FIG. 1 shows an example of a hybrid vehicle that can be controlled by the present invention. A vehicle Ve shown in FIG. 1 is a hybrid vehicle having an engine (ENG) 1 and a first motor (MG1) 2 and a second motor (MG2) 3 as driving force sources. The vehicle Ve is configured to divide and transmit the power output from the engine 1 to the first motor 2 side and the drive shaft 5 side by the power split mechanism 4. Further, the power generated by the first motor 2 is supplied to the second motor 3, and the power output from the second motor 3 can be applied to the drive shaft 5.

  The power split mechanism 4 is constituted by a planetary gear mechanism having a sun gear 6, a ring gear 7, and a carrier 8. In the example shown in FIG. 1, a single pinion type planetary gear mechanism is used. That is, a ring gear 7 of an internal gear is disposed concentrically with the sun gear 6. A pinion gear 9 meshing with the sun gear 6 and the ring gear 7 is held by a carrier 8 so that it can rotate and revolve.

  The power split mechanism 4 is disposed on the same rotational axis as the engine 1 and the first motor 2. An input shaft 4 a of the power split mechanism 4 is coupled to the carrier 8 of the planetary gear mechanism that constitutes the power split mechanism 4. An output shaft 1a of the engine 1 is connected to the input shaft 4a via a flywheel 11 provided with a damper mechanism 10. That is, the carrier 8 is connected to the engine 1 via the input shaft 4 a, the damper mechanism 10, and the flywheel 11.

  A brake mechanism that prevents reverse rotation of the output shaft 1a (rotation in the direction opposite to the rotation direction of the engine 1) may be provided between the output shaft 1a of the engine 1 and the input shaft of the power split mechanism 1. . As the brake mechanism, for example, a one-way clutch type brake configured to be engaged and stopped when a torque in a direction opposite to the rotation direction of the engine 1 is applied is used. Alternatively, a friction clutch or a dog clutch type brake can be used.

  The flywheel 11 and the damper mechanism 10 are provided between the output shaft 1a and the input shaft 4a. The flywheel 11 is connected to the output shaft 1a, and the damper mechanism 10 is attached to the opposite side of the flywheel 11 from the engine 1 (left side in FIG. 1).

  The damper mechanism 10 has the same configuration as the damper portion of the damper mechanism described in Patent Document 1 described above or a conventional general damper mechanism, for example. The damper spring 10a acts on the torque fluctuation and vibration of the engine 1 due to the action of the damper spring 10a. It is comprised so that the torsional vibration of the output shaft 1a resulting from it may be suppressed. For example, a compression coil spring is used as the damper spring 10a, and the expansion / contraction direction thereof is arranged so as to coincide with the circumferential direction or the tangential direction of the damper mechanism 10.

  In the damper mechanism described in Patent Document 1 described above, the torque limiter is disposed on the outer peripheral side of the damper spring at the position where the damper spring is disposed. On the other hand, in the configuration of the vehicle Ve, the torque limiter 12 is separated from the damper mechanism 10 and disposed inside the power split mechanism 4 as described later. For this reason, in the damper mechanism 10, a damper spring 10 a is disposed on the outer peripheral side where the torque limiter is disposed in the conventional configuration. Therefore, this damper spring 10a can lengthen the full length of the damper spring 10a compared with the conventional structure by which the torque limiter is arrange | positioned at the outer peripheral side. That is, the damper mechanism 10 has an enhanced effect of suppressing torsional vibration compared to a damper mechanism having a conventional configuration.

  The first motor 2 is connected to the sun gear 6 of the planetary gear mechanism. The first motor 2 is disposed adjacent to the power split mechanism 4 on the side opposite to the engine 1 (left side in FIG. 1). A rotor shaft 2 b that rotates integrally with the rotor 2 a of the first motor 2 is connected to the sun gear 6. The rotating shafts of the rotor shaft 2b and the sun gear 6 are hollow shafts, and the rotating shaft 13a of the oil pump 13 is connected to the output shaft 1a through the hollow portion.

  A first drive gear 14 is connected to the ring gear 7 of the planetary gear mechanism via a torque limiter 12. The torque limiter 12 is a mechanism for limiting the magnitude of torque transmitted between the ring gear 7 and the first drive gear 14. Detailed configurations of the torque limiter 12 and the ring gear 7 and the first drive gear 14 will be described later.

  A counter shaft 15 is disposed in parallel with the rotation shafts of the engine 1, the power split mechanism 4, and the first motor 2. A counter driven gear 16 that meshes with the first drive gear 14 is attached to one end (right side in FIG. 1) of the counter shaft 15 so as to rotate integrally. A counter drive gear 17 is attached to the other end (left side in FIG. 1) of the counter shaft 15 so as to rotate integrally with the counter shaft 15. The counter drive gear 17 is meshed with a diff ring gear 18a of a differential gear 18 that is a final reduction gear. The counter drive gear 17 and the diff ring gear 18a meshing with the counter drive gear 17 may be referred to as a final drive gear and a final driven gear, respectively. Therefore, the ring gear 7 of the power split mechanism 4 is connected to the drive shaft 5 via the gear train including the first drive gear 14, the counter shaft 15, the counter driven gear 16, and the counter drive gear 17, and the differential ring gear 18a. It is connected to the power transmission.

  The torque output from the second motor 3 can be added to the torque transmitted from the power split mechanism 4 to the drive shaft 5. Specifically, a rotor shaft 3 b that rotates integrally with the rotor 3 a of the second motor 3 is arranged in parallel with the counter shaft 15. A second drive gear 19 that meshes with the counter driven gear 16 is attached to the tip (right end in FIG. 1) of the rotor shaft 3b so as to rotate integrally. Therefore, the second motor 3 is connected to the ring gear 7 of the power split mechanism 4 via the gear train and the second drive gear 19 as described above so that power can be transmitted.

  As described above, the ring gear 7 and the first drive gear 14 of the power split mechanism (planetary gear mechanism) 4 in the power transmission device of the vehicle Ve are formed separately and integrated by the torque limiter 12. ing. Specifically, as shown in FIG. 2, the first drive gear 14 is disposed on the outer peripheral portion of the ring gear 7 that is an internal gear. The first drive gear 14 is formed by a cylindrical member having a cylindrical portion 14a. An external gear 14b that meshes with the counter driven gear 16 is formed on the outer peripheral portion of the cylindrical portion 14a.

  The first drive gear 14 is supported by a pair of bearings 20 and 21. Specifically, both ends of the inner peripheral portion of the cylindrical portion 14a are supported by the bearing 20 and the bearing 21, respectively. Therefore, the cylindrical portion 14 a also functions as a rotation shaft of the first drive gear 14. The first drive gear 14 is configured as a member having high support rigidity by being supported at two locations on both ends of the cylindrical portion 14a that also functions as a rotating shaft as described above.

  The ring gear 7 and the torque limiter 12 are disposed on the inner peripheral portion of the cylindrical portion 14 a of the first drive gear 14 and between the bearing 20 and the bearing 21. The ring gear 7 and the torque limiter 12 are arranged in series in the axial direction of the rotation shaft of the first drive gear 14, that is, in the axial directions of the output shaft 1a, the input shaft 4a, and the rotor shaft 2b.

  The inner peripheral surface of the cylindrical portion 14a of the first drive gear 14, the outer peripheral surface of the ring gear 7, and the outer peripheral surface of the torque limiter 12 have a so-called enamel structure, and are configured so that their positioning and assembly are easy. Has been. The first drive gear 14 and the ring gear 7 are fitted so as to relatively rotate with a torque smaller than the torque limited by the torque limiter 12.

  The torque limiter 12 has a configuration similar to that of a multi-plate clutch as used in a conventional general automatic transmission, for example. Specifically, the friction plates fixed to the ring gear 7 and the first drive gear 14 are pressed by the biasing force of the springs and are frictionally engaged with each other. Thereby, the ring gear 7 and the first drive gear 14 are integrated. The frictional engagement force between the friction plates in the torque limiter 12 is determined according to the biasing force of the spring spring. Therefore, the spring constant of the spring spring is adjusted, and the value of the torque limited by the torque limiter 12, that is, the upper limit value of the torque transmitted through the torque limiter 12 is set.

  As described above, the ring gear 7 and the torque limiter 12 are disposed on the inner peripheral portion of the cylindrical portion 14a of the first drive gear 14 and support the cylindrical portion 14a, that is, both end portions of the rotation shaft of the first drive gear 14. Between the two bearings 20, 21. Therefore, the ring gear 7 and the torque limiter 12 are assembled to the cylindrical portion 14a of the first drive gear 14 that is supported at both ends and has high rigidity. Therefore, the support rigidity of the ring gear 7 and the torque limiter 12 can also be increased, and the occurrence of vibration and deformation in the ring gear 7 and the torque limiter 12 can be suppressed.

  Furthermore, a weight 22 for increasing the moment of inertia of the first drive gear 14 is attached to the first drive gear 14 in the power transmission device of the vehicle Ve. In the example shown in FIG. 2, an annular weight 22 is attached to the outer peripheral portion of the cylindrical portion 14 a opposite to the side where the external gear 14 b is formed so as to rotate integrally with the first drive gear 14. .

  The weight 22 can be attached at a position as shown in FIG. In the example shown in FIG. 3, an external gear 14 b is formed at the center portion of the cylindrical portion 14 a in the first drive gear 14. A weight 22 is attached adjacent to the external gear 14b (on the left side of the external gear 14b in the example of FIG. 3).

  In the power transmission device of the vehicle Ve, it is known that the damping effect of vibration transmitted from the engine 1 to the drive shaft 5 side can be enhanced by increasing the moment of inertia of the first drive gear 14 by design. Therefore, by attaching the weight 22 to the first drive gear 14 as described above, the inertia moment of the first drive gear 14 can be increased, and the vibration damping effect in the power transmission device can be enhanced. Performance can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Engine (ENG), 1a ... Output shaft, 2 ... 1st motor (MG1), 3 ... 2nd motor (MG2), 4 ... Power split mechanism (planetary gear mechanism), 4a ... Input shaft, 5 ... Drive shaft 6 ... Sun gear, 7 ... Ring gear, 8 ... Carrier, 10 ... Damper mechanism, 10a ... Damper spring, 12 ... Torque limiter, 14 ... First drive gear, 14a ... Cylindrical part, 14b ... External gear, 15 ... Counter shaft , 16 ... Counter driven gear (counter gear), 17 ... Counter drive gear (counter gear; final drive gear), 19 ... Second drive gear, 20, 21 ... Bearing, 22 ... Weight (mass body), Ve ... Hybrid vehicle.

Claims (3)

A planetary gear mechanism disposed on the same axis as the rotation shaft of the engine and the first motor, and a counter shaft disposed in parallel with the rotation shaft, the engine and the first motor and the second motor as driving force sources; A counter gear attached to the counter shaft for transmitting power to the drive shaft, a damper mechanism for absorbing torsional vibration between the engine and the planetary gear mechanism by the elasticity of a damper spring, the engine and the A torque limiter for limiting a torque transmitted to and from the drive shaft, a sun gear of the planetary gear mechanism is connected to the first motor, and a ring gear meshes with the counter gear. And the carrier is connected to the engine via the damper mechanism, and the second motor is connected to the front shaft. In the power transmission apparatus for a hybrid vehicle that is connected to the drive shaft through the second drive gear and the counter gear meshing with the counter gear,
The ring gear and the first drive gear are configured separately from each other, and are integrally connected via the torque limiter,
The power transmission device for a hybrid vehicle, wherein the damper spring is arranged on the outermost peripheral side of the damper mechanism in a direction that expands and contracts in a circumferential direction of the damper mechanism.
The power transmission device for a hybrid vehicle according to claim 1,
A pair of bearings for supporting both end portions of the rotating shaft of the first drive gear;
The first drive gear is constituted by a member having a cylindrical portion in which an external gear that meshes with the counter gear is formed on an outer peripheral portion;
The power transmission device for a hybrid vehicle, wherein the ring gear and the torque limiter are arranged in series in an axial direction of the counter shaft between an inner peripheral portion of the cylindrical portion and the pair of bearings.
The power transmission device for a hybrid vehicle according to claim 1 or 2,
A power transmission device for a hybrid vehicle, wherein an annular mass body for increasing the moment of inertia of the first drive gear is attached to an outer peripheral portion of the cylindrical portion.

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