JP2019077203A - Power transmission for hybrid vehicle - Google Patents

Abstract

To provide a power transmission for a hybrid vehicle which suitably restrains eccentricity from a rotation axis of a crank shaft of a damper.SOLUTION: An input shaft 16 is supported by a shaft end part 16g of an engine 14 side of the input shaft 16 being fitted in a crank shaft 14a of the engine 14 in a state of being relatively rotatable around a rotation axis Cc of the crank shaft 14a, and a shaft end part 16a opposed to the engine 14 side of the input shaft 16 is relatively and rotatably supported on a case CA of a power transmission 12 via a first needle bearing 52 and thereby is rotatably supported. Therefore, the eccentricity from the rotation axis Cc of the crank shaft 14a of a damper device 30 is suitably restrained by the input shaft 16 even though the damper device 30 attempts to decenter from the rotation axis Cc of the crank shaft 14a because the shaft end part 16g of the input shaft 16 is supported on the crank shaft 14a in a state of being relatively rotatable around the rotation axis Cc.SELECTED DRAWING: Figure 2

Description

  According to the present invention, there is provided a differential mechanism having a first rotating element and a second rotating element and a third rotating element motively coupled to an engine through an input shaft, and between the engine and the input shaft. The present invention relates to a technology for suitably suppressing the eccentricity of the damper from the rotation axis of the crankshaft of the engine in a power transmission device for a hybrid vehicle including a damper provided in a power transmission path.

  POWER TRANSMISSION FOR HYBRID VEHICLE COMPRISING A DIFFERENTIAL MECHANISM HAVING A DIFFERENTIAL MECHANISM HAVING A FIRST ROTATING ELEMENT HAVING POWER TRANSFERABLE CONNECTION AND A CURRENT AND A THIRD ROTATING ELEMENT The device is known. For example, a power transmission apparatus for a hybrid vehicle described in Patent Document 1 is that. In the power transmission device for a hybrid vehicle of Patent Document 1, the input shaft can be rotated relative to the rotor shaft provided at the motor via the first bearing at the end of the input shaft opposite to the engine side. And a part different from the shaft end of the input shaft is rotatably supported by being relatively rotatably supported by the case of the power transmission device via a second bearing. .

JP, 2016-158437, A

  By the way, in a conventional power transmission device for a hybrid vehicle as in Patent Document 1, a damper is provided on a power transmission path between the engine and the input shaft, and for example, a hub member of the damper is splined to the input shaft Some are fitted and supported. In such a power transmission device for a hybrid vehicle, for example, when a relatively large torque is temporarily generated, the torque limiter operates to cause the damper to slide relative to the flywheel, and the damper is the rotational axis of the crankshaft. When trying to decenter from the center, the damper is supported outside the position between the two supporting positions at the input shaft via the first bearing and the second bearing, so that the free end of the input shaft is There is a problem that a certain shaft end is eccentric from the rotational axis of the crankshaft and the damper is also eccentric from the rotational axis of the crankshaft. When the damper is eccentric from the rotation axis of the crankshaft, there is a risk that the vibration isolation performance of the damper may be degraded.

  The present invention has been made against the background described above, and it is an object of the present invention to provide a power transmission device for a hybrid vehicle which can preferably suppress the eccentricity of the damper from the rotation axis of the crankshaft. is there.

  According to a first aspect of the present invention, there is provided: (a) a first rotating element coupled to the electric motor in a power transmitting manner, and a second rotating element and a third rotating element coupled to the engine in a power transmitting manner via the input shaft. A power transmission device for a hybrid vehicle, comprising: a differential mechanism having: a damper, and a damper provided in a power transmission path between the engine and the input shaft, wherein (b) the input shaft is the input shaft The shaft end on the engine side of the engine is rotatably supported on the crankshaft of the engine so as to be rotatable relative to the rotational axis of the crankshaft, and a portion of the input shaft that supports the damper A part of the side opposite to the shaft end is rotatably supported by being rotatably supported by the case of the power transmission device via a bearing.

  According to the first aspect of the invention, the input shaft is supported such that the shaft end of the input shaft on the engine side is fitted to the crankshaft of the engine so as to be relatively rotatable around the rotational axis of the crankshaft. A portion of the input shaft opposite to the shaft end with respect to the portion supporting the damper is rotatably supported by a case of the power transmission device via a bearing so as to be relatively rotatable. It is supported. Therefore, even if the damper is intended to be eccentric from the rotational axis of the crankshaft, the shaft end of the input shaft on the engine side is supported by the crankshaft so as to be relatively rotatable around the rotational axis. The eccentricity of the damper from the rotational axis of the crankshaft is preferably suppressed by the input shaft.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a skeleton view schematically illustrating a configuration of a power transmission device for a hybrid vehicle to which the present invention is preferably applied. FIG. 2 is a cross-sectional view showing a part of the power transmission system for a hybrid vehicle of FIG. 1; FIG. 3 is a sectional view taken along the line III-III in FIG. FIG. 7 is a cross-sectional view for explaining a power transmission system for a hybrid vehicle according to another embodiment of the present invention.

  In the embodiment of the present invention, (a) a cylindrical portion is formed at the end of the input shaft on the engine side, and (b) the tip of the crankshaft is a cylinder of the input shaft. (C) The cylindrical portion of the input shaft is rotated by the inner peripheral surface of the cylindrical portion of the crankshaft. It is supported for relative rotation around an axis. Therefore, even if the damper is intended to be eccentric from the rotational axis of the crankshaft, the cylindrical portion of the input shaft is supported relatively rotatably around the rotational axis by the inner peripheral surface of the cylindrical portion of the crankshaft. Accordingly, the eccentricity of the damper from the rotational axis of the crankshaft is preferably suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton view illustrating a power transmission device (a power transmission device for a hybrid vehicle) 12 of the hybrid vehicle 10 to which the present invention is applied. The power transmission device 12 is a transaxle type hybrid vehicle transaxle such as an FF vehicle in which a plurality of shafts are arranged along the vehicle width direction, and is accommodated in the case CA.

  The power transmission device 12 is provided with a first axis C1 to a fourth axis C4 substantially parallel to the vehicle width direction, and is connected to the engine 14 as a driving power source so as to be able to transmit power on the first axis C1. An input shaft 16 which is an input shaft is provided, and a single pinion type planetary gear unit (differential mechanism) 18 and a first electric motor (electric motor), that is, a first motor generator MG1 are disposed concentrically with the first axis C1. It is set up. The planetary gear set 18 and the first motor generator MG1 function as an electrically driven differential unit, and the input shaft 16 is connected to a carrier (second rotating element) C of the planetary gear set 18 which is a differential mechanism so as to transmit power. The first motor generator MG1 is connected to the sun gear (first rotating element) S so that power can be transmitted, and the ring gear (third rotating element) R is provided with an output gear Ge. As shown in FIG. 2, the first motor generator MG1 is, for example, a stator ST fixed to a first case member CA1 constituting a part of the case CA by a first fastening bolt BO1, and a cylindrical shape inside The rotor shaft RS is integrally fixed with the rotor RO and the like, and the cylindrical rotor shaft RS and the sun gear S are coupled so as to be able to transmit power.

  On the second axis C2, there is disposed a reduction gear device 22 in which a large reduction gear Gr1 and a small reduction gear Gr2 are provided at both ends of the shaft 20, and the large reduction gear Gr1 is engaged with the output gear Ge. . Further, the large reduction gear Gr1 is engaged with the motor output gear Gm of the second motor, that is, the second motor generator MG2 disposed on the third axis C3. Further, the small reduction gear Gr2 is engaged with the differential ring gear Gd of the differential device 24 disposed on the fourth axis C4. The power transmission device 12 configured as described above includes, for example, a planetary gear device 18, a reduction gear device 22, a differential device 24, left and right axles 26, and a damper device (damper) 30 described later. For example, the driving force from the engine 14 and the second motor generator MG2 is transmitted to the driving wheel 28.

  Further, as shown in FIG. 1 and FIG. 2, rotation is performed by the damper device 30 provided on the power transmission path between the crankshaft 14 a of the engine 14 and the input shaft 16 and the engine 14 on the first axis C1. By being driven, an operating oil pressure that is an original pressure of the oil pressure control circuit is generated, and an oil pump 32 for supplying lubricating oil to, for example, the planetary gear set 18 and the like is provided. The oil pump 32 is coupled to the engine 14 via an oil pump drive shaft 34 disposed on the inner peripheral side of the cylindrical rotor shaft RS and the input shaft 16 so that power can be transmitted. .

  In the damper device 30, as shown in FIG. 2, annular side plates 38a and 38b connected to the crankshaft 14a via a flywheel 36 so as to be able to transmit power, and the input shaft 16 are connected to be relatively nonrotatable. An annular hub member 40 and a coil spring 42 as a torque fluctuation absorbing member provided between a flange portion 40a formed on the hub member 40 and the side plates 38a and 38b are provided. In the embodiment, three coil springs 42 are arranged at equal intervals in the circumferential direction of the side plates 38 a and 38 b and the hub member 40, and the coil springs 42 include the side plates 38 a and 38 b and the hub member 40. When twisting occurs with the flange portion 40a, it elastically deforms (contracts) and absorbs torque fluctuations between the crankshaft 14a and the input shaft 16. Also, in the power transmission path between the flywheel 36 and the side plates 38a, 38b, torque that prevents torque transmitted from the engine 14 to the input shaft 16 from transmitting torque exceeding a preset limit torque is prevented. A limiter 44 is provided.

  As shown in FIG. 2, the input shaft 16 is a long member extending in the direction of the first axis C1. The shaft end 16a of the input shaft 16 on the opposite side to the engine 14 side has its shaft end A longitudinal shaft connecting portion 16b projected to the side opposite to the engine 14 side in the direction of the first axis C1 to connect with the oil pump drive shaft 34 from the portion 16a, and projected outward from the shaft end portion 16a A flange-like flange portion 16c is formed. A fitting hole 16e for fitting the end 34a of the oil pump drive shaft 34 on the side of the engine 14 relative to the input shaft 16 is formed in the distal end 16d of the longitudinal shaft connecting portion 16b. The input shaft 16 is supplied with lubricating oil communicated with the fitting hole 16e and discharged from the oil pump 32 via, for example, the oil passage 34b formed in the oil pump drive shaft 34 to, for example, the planetary gear set 18 An oil passage 16f is formed. Further, the carrier C has a pinion shaft 46 rotatably supporting the pinion gear P, and a pair of disc-shaped support walls 48 and 50 supporting both end portions of the pinion shaft 46. The support wall 50 on the engine 14 side of the pair of support walls 48 and 50 is integrally connected to the flange portion 16 c of the input shaft 16.

  Further, as shown in FIG. 2, in the input shaft 16, the shaft end 16 g of the input shaft 16 on the engine 14 side is engaged with the crankshaft 14 a of the engine 14 so as to be relatively rotatable around the rotation axis Cc of the crankshaft 14 a Is supported, and the shaft end 16a of the input shaft 16 on the opposite side to the engine 14 side rotates relative to the second case member CA2 constituting a part of the case CA via the first needle bearing (bearing) 52 By being able to be supported, it is rotatably supported about the first axis C1. The rotational axis Cc of the crankshaft 14a coincides with the first axis C1. Further, in the second case member CA2, a partition portion CA2a separating the first accommodation space S1 for accommodating the planetary gear device 18 and the second accommodation space S2 for accommodating the damper device 30 is formed. A first needle bearing 52 is interposed between the inner peripheral surface CA2b of the partition wall portion CA2a of the member CA2 and the outer peripheral surface of the shaft end 16a on the opposite side to the engine 14 side of the input shaft 16. Further, the shaft end 16a opposite to the engine 14 side of the input shaft 16 is a part of the input shaft 16 opposite to the shaft end 16g with respect to the portion of the damper device 30 that supports the hub member 40. is there. The portion of the input shaft 16 supporting the hub member 40 of the damper device 30 is an outer peripheral spline that splines with the inner peripheral spline teeth 40c formed on the inner peripheral surface of the cylindrical portion 40b of the hub member 40. The teeth 16 h are a part of the input shaft 16 formed on the outer peripheral surface.

  As shown in FIGS. 2 and 3, a cylindrical portion 16i having a cylindrical shape is formed at an end 16g on the side of the engine 14 of the input shaft 16, and the tip 14b of the crankshaft 14a is formed at the input shaft 16 A cylindrical portion 14c in which the cylindrical portion 16i is directly fitted slidably is formed, and the cylindrical portion 16i of the input shaft 16 is cranked by the inner circumferential surface 14d of the cylindrical portion 14c of the crankshaft 14a. It is supported so as to be relatively rotatable around the rotation axis Cc of the shaft 14a. As shown in FIG. 3, the input shaft is formed such that a slight gap SK is formed between the outer peripheral surface 16j of the cylindrical portion 16i of the input shaft 16 and the inner peripheral surface 14d of the cylindrical portion 14c of the crankshaft 14a. Sixteen cylindrical portions 16i are directly fitted into the cylindrical portion 14c of the crankshaft 14a. Further, a flange portion 14e integrally formed on the inner circumferential portion 36a of the flywheel 36 by a second fastening bolt BO2 is formed at the tip end portion 14b of the crankshaft 14a.

  Note that, unlike the configuration of the power transmission device 12 of the present embodiment, a second needle bearing is provided between the tip 16 d of the shaft connecting portion 16 b of the input shaft 16 and the shaft end RSa of the rotor shaft RS on the engine 14 side. Compared with the conventional power transmission device in which the input shaft 16 is rotatably supported at two points via the first needle bearing 52 and the second needle bearing, the power transmission device 12 of this embodiment is: The second needle bearing is not interposed between the end 16 d of the shaft connecting portion 16 b of the input shaft 16 and the shaft end RSa of the rotor shaft RS on the engine 14 side. Therefore, in the power transmission device 12 of the present embodiment, during the EV traveling in which the crankshaft 14a of the engine 14 and the input shaft 16 of the engine 14 are stopped and the rotor RO of the first motor generator MG1, that is, the rotor shaft RS is rotating. The mechanical loss generated in the second needle bearing is reduced. In the above-described conventional power transmission device, since the cylindrical portion 16i is not formed on the input shaft 16, for example, a relatively large torque is temporarily generated, whereby the torque limiter 44 operates to cause the damper device 30 to fly. If the damper device 30 slips against the wheel 36 and tries to make the damper device 30 eccentric from the rotational axis Cc of the crankshaft 14a, the free end of the input shaft 16 becomes eccentric from the rotational axis Cc of the crankshaft 14a and the damper device 30 also rotates the crankshaft 14a. It decenters from the axis Cc.

  As described above, according to the power transmission device 12 of this embodiment, the shaft end 16g of the input shaft 16 on the engine 14 side of the input shaft 16 is the crankshaft 14a of the engine 14 around the rotation axis Cc of the crankshaft 14a. And a portion of the input shaft 16 opposite to the shaft end 16a with respect to the portion supporting the damper device 30, ie, opposite to the engine 14 side of the input shaft 16 The side shaft end 16a is rotatably supported by the case CA of the power transmission 12 via the first needle bearing 52 so as to be relatively rotatable. Therefore, even if the damper device 30 tries to be eccentric from the rotation axis Cc of the crankshaft 14a, the shaft end 16g on the engine 14 side of the input shaft 16 is supported by the crankshaft 14a so as to be relatively rotatable around the rotation axis Cc. Therefore, the eccentricity from the rotation axis Cc of the crankshaft 14 a of the damper device 30 is suitably suppressed by the input shaft 16.

  Further, according to the power transmission device 12 of the present embodiment, a cylindrical portion 16i having a cylindrical shape is formed at the shaft end 16g on the engine 14 side of the input shaft 16, and an input is made at the tip 14b of the crankshaft 14a. A cylindrical portion 14c in which a cylindrical portion 16i of the shaft 16 is slidably fitted is formed, and the cylindrical portion 16i of the input shaft 16 is cranked by the inner peripheral surface 14d of the cylindrical portion 14c of the crankshaft 14a. It is supported so as to be relatively rotatable around the rotation axis Cc of the shaft 14a. Therefore, even if the damper device 30 tries to be eccentric from the rotation axis Cc of the crankshaft 14a, the cylindrical portion 16i of the input shaft 16 can be relatively rotated around the rotation axis Cc by the inner peripheral surface 14d of the cylindrical portion 14c of the crankshaft 14a. Being supported, eccentricity from the rotation axis Cc of the crankshaft 14 a of the damper device 30 is suitably suppressed.

  Next, another embodiment of the present invention will be described. The same reference numerals are given to parts common to the above-described first embodiment and the description will be omitted.

  FIG. 4 is a view for explaining a power transmission device (power transmission device for hybrid vehicles) 100 according to another embodiment of the present invention. Compared with the power transmission device 12 of the first embodiment, the power transmission device 100 of the present embodiment does not have the shaft connecting portion 16 b formed at the shaft end 16 a of the input shaft 102, and the tip of the oil pump drive shaft 34. , And the other parts are substantially the same as those of the power transmission device 12 of the first embodiment. According to the power transmission device 100 configured as described above, the length of the input shaft 102 in the direction of the first axis C1 can be shortened as compared to the input shaft 16 of the first embodiment. Weight reduction and reduction of the manufacturing cost of the input shaft 102 can be suitably performed.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is also applicable in other aspects.

  For example, in the above-described embodiment, the shaft end 16a of the input shaft 16 on the opposite side to the engine 14 side is rotatably supported by the second case member CA2 of the case CA via the first needle bearing 52. However, rolling bearings other than the first needle bearing 52, for example, ball bearings, cylindrical roller bearings, etc. may be used, and furthermore, sliding bearings may be used instead of rolling bearings.

  In the power transmission devices 12 and 100 of the above-described embodiment, the shaft end 16a of the input shaft 16 is supported by the second case member CA2 via the first needle bearing 52, but the shaft end of the input shaft 16 A portion between the shaft end 16a which is not the portion 16a and the portion closer to the engine 14 than the shaft end 16a, that is, a portion between the shaft end 16a and the portion supporting the damper device 30 in the input shaft 16 The shapes of the parts constituting the power transmission device 12 or 100 may be changed so as to be supported by the two case members CA2.

  Note that what has been described above is merely an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

12, 100: Power transmission device (power transmission device for hybrid vehicles)
14: Engine 14a: Crankshaft 16, 102: Input shaft 16g: Shaft end 18: Planetary gear (differential mechanism)
30: Damper device (damper)
52: 1st needle bearing (bearing)
C: Carrier (second rotating element)
CA: Case Cc: Rotational axis R: Ring gear (third rotation element)
S: Sun gear (1st rotation element)
MG1: 1st motor generator (motor)

Claims (1)

A differential mechanism having a first rotating element power-transferably connected to a motor, and a second rotating element and a third rotating element power-connected to the engine via an input shaft; the engine and the input What is claimed is: 1. A power transmission device for a hybrid vehicle, comprising: a damper provided in a power transmission path between the shaft and the shaft;
The input shaft is supported such that a shaft end of the input shaft on the engine side is fitted to the crankshaft of the engine so as to be relatively rotatable around the rotation axis of the crankshaft, and the input shaft A part of the side opposite to the shaft end with respect to the part that supports the damper is rotatably supported by being rotatably supported by the case of the power transmission device via a bearing. Power transmission device for hybrid vehicles.

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