JP2022007781A - Drive unit for vehicle - Google Patents

Abstract

To provide a drive unit for a vehicle which suitably suppresses wear between internal peripheries of both end parts of a cylindrical gear when the cylindrical gear rotates and an outer ring of a rolling bearing.SOLUTION: Since an internal peripheral face 32e of an output gear 32 is formed so that an inside diameter Din becomes large as progressing toward either of a first rolling bearing 48 and a second rolling bearing 50 in a rotation axial line C direction, oil LF supplied to an internal periphery of the output gear 32 flows toward one of outer rings 48b, 50b of the first rolling bearing 48 and the second rolling bearing 50, and the oil LF is supplied between the outer rings 48b, 50b and internal peripheries of end parts 32b, 32d of the output gear 32. Also, since the oil LF which is supplied to the internal periphery of the output gear 32 is accumulated in a space SP which is formed at the internal periphery of the output gear 32, the oil LF which is dammed up by the outer rings 48b, 50b is supplied between the outer rings 48b, 50b and the internal peripheries of the end parts 32b, 32d of the output gear 32.SELECTED DRAWING: Figure 3

Description

The present invention relates to a vehicle drive device including a cylindrical gear in which an outer ring of a pair of rolling bearings is fitted to the inner circumferences of both ends and is rotatably supported around a rotation axis by the pair of rolling bearings. The present invention relates to a technique for suitably suppressing wear between the inner circumferences of both ends of the cylindrical gear and the outer ring of the rolling bearing when the cylindrical gear is rotating.

A well-known vehicle drive device is provided with a cylindrical gear in which an outer ring of a pair of rolling bearings is fitted to the inner circumferences of both ends and is rotatably supported around a rotation axis by the pair of rolling bearings. For example, the vehicle drive device described in Patent Document 1 is that.

Japanese Unexamined Patent Publication No. 2020-44986

By the way, in the vehicle drive device of Patent Document 1 described above, in order to rotatably support the cylindrical gear around the rotation axis, for example, the inner ring of the pair of rolling bearings is a non-rotating member (trans axle case). ), The outer ring of the pair of rolling bearings may be fitted to the inner circumferences of both ends of the cylindrical gear. In this case, by press-fitting the inner ring of the rolling bearing into the non-rotating member, the fit between the outer ring of the rolling bearing and the inner circumferences of both ends of the cylindrical gear tends to be loosened. When the cylindrical gear rotates around the rotation axis, the outer ring of the rolling bearing slides with respect to the inner peripheral surfaces of both ends of the cylindrical gear, and the outer ring of the rolling bearing and the cylindrical gear There was a risk that the space between the inner circumferences of both ends would be worn.

The present invention has been made in the background of the above circumstances, and an object thereof is the inner circumferences of both ends of the cylindrical gear and the outer ring of the rolling bearing when the cylindrical gear is rotating. It is an object of the present invention to provide a drive device for a vehicle that suitably suppresses wear between the vehicle and the vehicle.

The gist of the first invention is (a) a cylindrical gear in which an outer ring of a pair of rolling bearings is fitted to the inner circumferences of both ends and is rotatably supported around the rotation axis by the pair of rolling bearings. , An oil pump, and a vehicle drive device in which a part of the oil discharged from the oil pump is supplied to the inner circumference of the gear, and (b) the inner circumference of the cylindrical gear. By blocking the oil supplied to the inner circumference of the gear with the outer ring of the pair of rolling bearings, a space for collecting the oil is formed on the inner circumference of the gear, and (c) the inside of the cylindrical gear. The peripheral surface is formed so that the inner diameter increases toward one of the pair of rolling bearings in the direction of the rotation axis.

According to the vehicle drive device of the first invention, the inner peripheral surface of the cylindrical gear is formed so that the inner diameter increases toward one of the pair of rolling bearings in the direction of the rotation axis. Therefore, the oil supplied to the inner circumference of the cylindrical gear flows toward one outer ring of the pair of rolling bearings, and the oil flows into the outer ring of the rolling bearing and the end of the cylindrical gear. It is suitably supplied between the circumference and the circumference. Further, since the oil supplied to the inner circumference of the cylindrical gear is stored in the space formed on the inner circumference of the cylindrical gear, the oil blocked by the outer ring of the pair of rolling bearings is blocked. It is suitably supplied between the outer ring of the rolling bearing and the inner circumferences of both ends of the cylindrical gear. Therefore, when the cylindrical gear is rotating, a part of the oil discharged from the oil pump is between the outer ring of the rolling bearing and the inner circumferences of both ends of the cylindrical gear due to centrifugal force. Therefore, wear between the inner circumferences of both end portions of the cylindrical gear and the outer ring of the rolling bearing when the cylindrical gear is rotating is suitably suppressed.

It is a figure explaining the outline of the structure of the drive device of the hybrid vehicle of one Embodiment of this invention. It is sectional drawing explaining the structure of the transaxle provided in the drive device of the hybrid vehicle of FIG. It is an enlarged view of the peripheral part of the output gear of FIG. FIG. 2 is a view of FIG. 2 viewed from the direction of arrow A. It is sectional drawing explaining the structure of the cylindrical output gear provided in the drive device of another Embodiment of this invention.

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

FIG. 1 is a diagram illustrating a schematic configuration of a drive device (vehicle drive device) 12 of a hybrid vehicle (hereinafter referred to as a vehicle) 10 to which the present invention is applied. As shown in FIG. 1, the drive device 12 includes an engine 14 as a driving force source for traveling, and a transaxle 18 which is a power transmission device for transmitting the power of the engine 14 to the drive wheels 16. The transaxle 18 includes, for example, a planetary gear type power distribution mechanism 20, a counter gear mechanism 22, a first electric motor MG1, a second electric motor MG2, a differential device 24, a drive shaft 26, and the like. ing.

As shown in FIG. 1, the power distribution mechanism 20 distributes the power output from the engine 14 to the first motor MG1 and the cylindrical output gear (cylindrical gear) 32 via the damper 28 and the input shaft 30. .. Further, the counter gear mechanism 22 has a counter shaft 22s in which a counter driven gear 22a that meshes with the counter drive gear 32a formed on the output gear 32 and a differential drive gear 22b that meshes with the differential ring gear 24a of the differential device 24 are fixed to each other. ing. Further, the second electric motor MG2 has an output gear 34 that meshes with the counter driven gear 22a of the counter gear mechanism 22. Further, the drive shaft 26 rotates together with the drive wheels 16. As shown in FIG. 2, the power distribution mechanism 20 includes a sun gear S that can rotate around the rotation axis C of the input shaft 30, a ring gear R arranged on the outer peripheral side of the sun gear S, and the sun gear S and the ring gear R. It is provided with a carrier CA that supports the pinion gear P that meshes with the engine so that it can rotate and revolve. The sun gear S is connected to the end of the substantially cylindrical rotating shaft 36 of the first electric motor MG1 on the engine 14 side by spline fitting so as not to rotate relative to each other. The carrier CA is connected to a flange portion 30a extending radially from the input shaft 30 so as not to rotate relative to each other, and the carrier CA is connected to the engine 14 and the oil pump drive shaft 38 so as to be able to transmit power. The ring gear R is integrally formed on the inner circumference of the output gear 32, and the ring gear R is connected to the second electric motor MG2 and the drive shaft 26 so as to be able to transmit power. Note that FIG. 2 is a cross-sectional view illustrating the configuration of the transaxle 18 provided in the drive device 12.

In the transaxle 18 configured in this way, the power of the engine 14 input via the damper 28 and the input shaft 30 is transmitted to the cylindrical output gear 32, and the counter gear mechanism 22 and the differential device 24 are transmitted from the output gear 32. , While the power of the second electric motor MG2 is sequentially transmitted to the drive wheels 16 via the pair of drive shafts 26 and the like, the power of the second electric motor MG2 is sequentially transmitted to the drive wheels 16 via the counter gear mechanism 22, the differential device 24, the pair of drive shafts 26 and the like. It is supposed to be transmitted to.

The container-shaped transaxle case 40 of the transaxle 18 partially shown in FIG. 2 is, for example, a non-rotating member including a first case member 40a, a second case member 40b, and a third case member 40c. The end faces (matching faces) of the case members in the direction of the rotation axis C are fastened by bolts to form one transaxle case 40.

As shown in FIGS. 1 and 2, the end portion (one end portion) of the input shaft 30 on the engine 14 side is connected to the crank shaft 14a of the engine 14 via a damper 28 so as to be able to transmit power, and the input shaft 30 is connected to the crank shaft 14a. Is driven to rotate by the engine 14. Further, a cylindrical oil pump drive shaft 38 is connected to the end (the other end) of the input shaft 30 opposite to the engine 14 side so as not to rotate relative to each other by, for example, spline fitting. Therefore, when the input shaft 30 is rotationally driven by the engine 14, the oil pump 42 provided in the transaxle 18 is driven via the oil pump drive shaft 38, and the oil pump 42 drives the oil LF (see FIG. 3). ) Is ejected. As shown in FIG. 2, the oil pump 42 is an inscribed gear type in which an annular driven gear 42a and a drive gear 42b having outer peripheral teeth that mesh with the inner peripheral teeth of the driven gear 42a are meshed with each other, and is driven by the oil pump. The end of the shaft 38 on the oil pump 42 side is connected to the drive gear 42b so as not to rotate relative to each other.

As shown in FIG. 2, the rotary shaft 36 includes an axial oil passage 36a penetrating inside the rotary shaft 36 along the rotation axis C direction and a first radial direction extending radially from the axial oil passage 36a. An oil passage 36b and a second radial oil passage 36c are formed. Further, the oil pump drive shaft 38 includes an axial oil passage 38a penetrating inside the oil pump drive shaft 38 along the rotation axis C direction and a radial oil passage 38b extending radially from the axial oil passage 38a. And are formed. As shown in FIG. 2, an oil pump drive shaft 38 smaller than the diameter of the rotary shaft 36 is housed in the axial oil passage 36a of the rotary shaft 36. Therefore, when the oil pump 42 is driven by the engine 14 and the oil LF is discharged from the oil pump 42 into the axial oil passage 38a of the oil pump drive shaft 38, the oil LF discharged into the axial oil passage 38a is discharged. Is partially supplied from the radial oil passage 38b formed in the oil pump drive shaft 38 into the axial oil passage 36a of the rotary shaft 36. Then, the oil LF supplied into the axial oil passage 36a of the rotating shaft 36 passes through the first radial oil passage 36b and the second radial oil passage 36c formed in the rotating shaft 36 by the centrifugal force of the rotating shaft 36. Through, for example, the coil end 44a of the stator 44 of the first electric motor MG1 is cooled.

Further, as shown in FIG. 2, the input shaft 30 has an axial oil passage 30b formed in a cylindrical shape along the rotation axis C direction inside the input shaft 30, and a radial oil passage 30b from the axial oil passage 30b. An extended first radial oil passage 30c and a second radial oil passage 30d are formed. The axial oil passage 30b formed in the input shaft 30 communicates with the axial oil passage 38a of the oil pump drive shaft 38. Therefore, when the oil LF is discharged from the oil pump 42 into the axial oil passage 38a of the oil pump drive shaft 38, a part of the oil LF discharged into the axial oil passage 38a is in the axial direction of the input shaft 30. The oil LF discharged into the oil passage 30b and discharged into the axial oil passage 30b has a cylindrical output through the first radial oil passage 30c and the second radial oil passage 30d formed in the input shaft 30. It is supplied to the inner circumference of the gear 32. The oil LF passing through the first radial oil passage 30c is not only received by the receiver 46 fixed to the disk member CAa of the carrier CA as shown by the arrow F1 shown in FIG. 3, but is also shown in FIG. As shown by the arrow F2, the oil is also supplied to the inner circumference of the cylindrical output gear 32. The arrows F1 and F2 shown in FIG. 3 are arrows showing an example of the flow of oil LF through the first radial oil passage 30c. A part of the oil LF received by the receiver 46 is supplied to the pinion gear P through the supply oil passage CAc formed in the shaft member CAb of the carrier CA. The receiver 46 is arranged so that the oil LF overflowing from the receiver 46 drops near the first rolling bearing 48, which will be described later. Further, the oil LF passing through the second radial oil passage 30d is supplied to the inner circumference of the cylindrical output gear 32 as shown by the arrows F3 and F4 shown in FIG. Arrows F3 and F4 in FIG. 3 are arrows showing an example of the flow of oil LF through the second radial oil passage 30d. Note that FIG. 3 is an enlarged view of the peripheral portion of the output gear 32 of FIG. 2.

As shown in FIG. 3, the output gear 32 has a counter drive gear 32a formed as outer peripheral teeth on the outer peripheral surface of the end portion 32b on the engine 14 side of the output gear 32, and is formed on the inner peripheral surface of the central portion 32c of the output gear 32. The ring gear R is a cylindrical gear formed as an inner peripheral tooth. Further, the output gear 32 has a support portion 40a1 formed on the first case member 40a of the transaxle case 40 in which the end portion 32b on the engine 14 side of the output gear 32 is a non-rotating member via the first rolling bearing 48. The end portion 32d of the output gear 32 on the side opposite to the engine 14 side is supported by the support portion 40b1 formed on the second case member 40b of the transaxle case 40 which is a non-rotating member via the second rolling bearing 50. By being supported, it is rotatably supported around the rotation axis C. That is, the cylindrical output gear 32 can be rotated around the rotation axis C by a pair of first rolling bearings 48 and second rolling bearings 50 fitted to the inner circumferences of both ends 32b and 32d of the output gear 32. It is supported. The first rolling bearing 48 is arranged in a row in the circumferential direction between the annular inner ring 48a, the annular outer ring 48b, the plurality of rolling elements 48c formed in a spherical shape, and the inner ring 48a and the outer ring 48b. It is a rolling bearing provided with a cage 48d that keeps the distance between the rolling elements 48c constant, and the second rolling bearing 50 includes an annular inner ring 50a, an annular outer ring 50b, and a plurality of spherically formed rolling bearings. It is a rolling bearing including a moving body 50c and a cage 50d that keeps a constant distance between the rolling elements 50c arranged in a row in the circumferential direction between the inner ring 50a and the outer ring 50b. Further, in the first rolling bearing 48, the inner ring 48a is press-fitted into the support portion 40a1 of the first case member 40a, and the outer ring 48b is fitted relatively loosely to the inner circumference of the end portion 32b on the engine 14 side of the output gear 32. ing. Further, in the second rolling bearing 50, the inner ring 50a is press-fitted into the support portion 40b1 of the second case member 40b, and the outer ring 50b is relatively relative to the inner circumference of the end portion 32d on the side opposite to the engine 14 side of the output gear 32. It is loosely fitted.

The inner peripheral surface 32e of the cylindrical output gear 32 includes the above-mentioned ring gear R, a first fitting surface 32f, a second fitting surface 32g, a first tapered surface 32h, and a second tapered surface 32i. Are formed respectively. The ring gear R is formed on the inner peripheral surface 32e of the central portion 32c of the output gear 32. Further, the first fitting surface 32f is an inner peripheral surface 32e formed on the end portion 32b on the engine 14 side of the output gear 32 into which the outer ring 48b of the first rolling bearing 48 is fitted. The second fitting surface 32g is an inner peripheral surface 32e formed on the end portion 32d of the output gear 32 opposite to the engine 14 side to which the outer ring 50b of the second rolling bearing 50 is fitted. Further, the first tapered surface 32h is formed so that the inner diameter Din of the output gear 32 increases from the ring gear R toward the first fitting surface 32f in the rotation axis C direction, that is, the ring gear in the rotation axis C direction. It is an inner peripheral surface 32e between the ring gear R and the first fitting surface 32f, which is formed so that the inner diameter Din increases toward the first rolling bearing 48 from R. Further, the second tapered surface 32i is formed so that the inner diameter Din increases toward the second fitting surface 32g from the ring gear R in the rotation axis C direction, that is, the second from the ring gear R in the rotation axis C direction. It is an inner peripheral surface 32e between the ring gear R and the second fitting surface 32g, which is formed so that the inner diameter Din increases toward the rolling bearing 50. Therefore, for example, when the oil LF is supplied to the first tapered surface 32h of the output gear 32, the oil LF supplied to the first tapered surface 32h flows toward the outer ring 48b of the first rolling bearing 48. Further, for example, when the oil LF is supplied to the second tapered surface 32i of the output gear 32, the oil LF supplied to the second tapered surface 32i flows toward the outer ring 50b of the second rolling bearing 50.

As shown in FIG. 3, the outer ring 48b of the first rolling bearing 48 so that the inner diameter Din1 of the outer ring 48b of the first rolling bearing 48 is smaller than the inner diameter Din of the first tapered surface 32h formed on the output gear 32. And the shape of the first tapered surface 32h of the output gear 32 is designed. Further, the outer ring 50b of the second rolling bearing 50 and the output gear 32 are arranged so that the inner diameter Din2 of the outer ring 50b of the second rolling bearing 50 is smaller than the inner diameter Din2 of the second tapered surface 32i formed on the output gear 32. The shape of the second tapered surface 32i is designed. Therefore, when the oil LF is supplied to the inner circumference of the output gear 32, as shown in FIG. 3, the oil LF supplied to the inner circumference of the output gear 32 rolls with the outer ring 48b of the first rolling bearing 48 and the second rolling. The oil LF supplied to the inner circumference of the output gear 32 is stored in the inner circumference of the output gear 32 by being dammed by the outer ring 50b of the bearing 50. That is, as shown in FIG. 3, on the inner circumference of the output gear 32, the oil LF supplied to the inner circumference of the output gear 32 is supplied by the pair of outer rings 48b and 50b of the first rolling bearing 48 and the second rolling bearing 50. By blocking the dam, a space SP for storing the oil LF is formed on the inner circumference of the output gear 32. The output gear 32 is formed with a through hole 32j penetrating in the radial direction in order to supply a part of the oil LF stored in the inner circumference of the output gear 32 to, for example, the differential drive gear 22b of the counter gear mechanism 22. Has been done.

FIG. 4 is a view of, for example, the output gear 32, the pair of first rolling bearings 48, and the second rolling bearing 50 shown in FIG. 2 as viewed from the direction of arrow A. As shown in FIG. 4, in the ring gear R formed on the inner circumference of the output gear 32, the end on the second rolling bearing 50 side of the ring gear R on the first rolling bearing 48 side is the rotation direction of the ring gear R. It is an oblique tooth gear formed so as to be on the FR side. The rotation direction FR of the ring gear R is, for example, the rotation direction in which the output gear 32, that is, the ring gear R rotates around the rotation axis C when the vehicle 10 moves forward. Therefore, as shown in FIG. 4, when the ring gear R, which is an oblique tooth gear, is rotated in the rotation direction FR, the oil LF stored in the inner circumference of the output gear 32 flows in the direction of the arrow F5. That is, the ring gear R is an oblique tooth gear that causes the oil LF accumulated in the inner circumference of the output gear 32 to flow toward the first rolling bearing 48 side when the output gear 32 rotates.

In the drive device 12 configured as described above, when the vehicle 10 travels forward, the output gear 32 rotates around the rotation axis C, and a part of the oil LF discharged from the oil pump 42 is inside the output gear 32. It is stored in the circumference. Therefore, when the output gear 32 is rotating around the rotation axis C, the oil LF stored in the inner circumference of the output gear 32 is generated by the centrifugal force of the first rolling bearing 48 as shown by the arrow F6 in FIG. Between the outer ring 48b and the inner circumference of the end 32b on the engine 14 side of the output gear 32, or between the outer ring 50b of the second rolling bearing 50 and the inner circumference of the end 32d on the opposite side of the output gear 32 from the engine 14 side. Suitably supplied in between. The arrow F6 is an arrow indicating an example of the flow of the oil LF stored in the inner circumference of the output gear 32 when the output gear 32 is rotating.

As described above, according to the drive device 12 of the present embodiment, the inner peripheral surface 32e of the cylindrical output gear 32 is one of the pair of first rolling bearings 48 and the second rolling bearing 50 in the rotation axis C direction. Since the inner diameter Din is formed to increase toward the direction of, the oil LF supplied to the inner circumference of the output gear 32 is the outer ring 48b of one of the pair of first rolling bearings 48 and the second rolling bearing 50. Flowing toward 50b, oil LF is suitably supplied between the outer rings 48b and 50b of the rolling bearings 48 and 50 and the inner circumferences of the ends 32b and 32d of the output gear 32. Further, since the oil LF supplied to the inner circumference of the output gear 32 is stored in the space SP formed on the inner circumference of the output gear 32, the outer ring 48b of the pair of first rolling bearings 48 and the second rolling bearing 50, The oil LF dampened by 50b is suitably supplied between the outer rings 48b and 50b of the pair of first rolling bearings 48 and the second rolling bearing 50 and the inner circumferences of both ends 32b and 32d of the output gear 32. Therefore, when the output gear 32 is rotating, a part of the oil LF discharged from the oil pump 42 is the outer rings 48b and 50b of the pair of first rolling bearings 48 and the second rolling bearing 50 due to centrifugal force and the output gear. Since it is suitably supplied between the inner circumferences of both ends 32b and 32d of 32, the first rolling bearing paired with the inner circumferences of both ends 32b and 32d of the output gear 32 when the output gear 32 is rotating. Wear between the outer rings 48b and 50b of the 48 and the second rolling bearing 50 is suitably suppressed.

Next, another embodiment of the present invention will be described. In the following description, the same reference numerals are given to the parts common to each other in the examples, and the description thereof will be omitted.

FIG. 5 is a cross-sectional view illustrating the configuration of a cylindrical output gear 32 provided in a drive device (vehicle drive device) according to another embodiment of the present invention. The drive device of the present embodiment is different in that the output gear 32 is not provided with the through hole 32j, and is substantially the same as the drive device 12 of the first embodiment. In the drive device of this embodiment, since the through hole 32j is not formed in the output gear 32, the amount of oil LF supplied to the inner circumference of the output gear 32 is preferably captured by the inner circumference of the output gear 32. To improve. Therefore, it is supplied between the inner circumferences of both ends 32b and 32d of the output gear 32 when the output gear 32 is rotating and the outer rings 48b and 50b of the pair of first rolling bearings 48 and the second rolling bearing 50. The amount of oil LF is preferably increased.

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

For example, in the above-described embodiment, the oil pump 42 is a mechanical oil pump that discharges oil LF by rotationally driving the input shaft 30, that is, the oil pump drive shaft 38 by the engine 14, but the oil pump of the present invention. May be, for example, an electric oil pump or the like. That is, any oil pump may be used as long as the discharged oil LF is supplied to the inner circumference of the output gear 32.

Further, in the above-described embodiment, the pair of first tapered surfaces 32h and the second tapered surface 32i are formed on the inner peripheral surface 32e of the output gear 32, respectively. For example, the inner peripheral surface 32e of the output gear 32 is formed. May form only one of the pair of first tapered surfaces 32h and the second tapered surface 32i.

It should be noted that the above is only one embodiment, and the present invention can be carried out in a mode in which various changes and improvements are made based on the knowledge of those skilled in the art.

12: Drive device (vehicle drive device)
32: Output gear (gear)
32b, 32d: Both ends 32e: Inner peripheral surface 42: Oil pump 48: First rolling bearing (rolling bearing)
48b: Outer ring 50: Second rolling bearing (rolling bearing)
50b: Outer ring C: Rotation axis Din: Inner diameter LF: Oil SP: Space

Claims (1)

A pair of rolling bearing outer rings are fitted to the inner circumferences of both ends, and a cylindrical gear rotatably supported around the rotation axis by the pair of rolling bearings, and an oil pump are provided and discharged from the oil pump. A vehicle drive device in which a part of the oil is supplied to the inner circumference of the gear.
A space is formed in the inner circumference of the cylindrical gear to store oil in the inner circumference of the gear by blocking the oil supplied to the inner circumference of the gear with the outer ring of the pair of rolling bearings.
A drive device for a vehicle, wherein the inner peripheral surface of the cylindrical gear is formed so that the inner diameter increases toward one of the pair of rolling bearings in the direction of the rotation axis.

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