JP2018040424A - Support structure of power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure of a power transmission device which can suppress the generation of wear between an inner ring and a support member without increasing the number of part items.SOLUTION: In a power transmission device for rotatably supporting a cylindrical gear member (25) having a gear at an external peripheral side to a support member (100a) by using a gear (102) having an outer ring (102a) which is internally fit to an internal peripheral face of the gear member and an inner ring (102b) which is externally fit to an external peripheral face of the support member, a lubrication groove (100b) into which a lubricant flows is formed at least at either of the support member and the inner ring at an external fit support part of the support member (100a) for externally-fittingly supporting the inner ring (102b), a bearing member (110c) supported to the support member (100a), and constituting a bearing (110) different from the bearing (102) is extended toward an end part of the lubrication groove (100b) at a downstream side in a lubricant flow direction, and an oil sump (120) is thereby formed between the support member (100a) and the inner ring (102b) at the external fit support part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a support structure for a power transmission device for a vehicle.

  2. Description of the Related Art Conventionally, a cylindrical gear member having a gear on the outer peripheral side is provided with a rolling bearing having an outer ring fitted on the inner peripheral surface of the gear member and an inner ring fitted on the outer peripheral surface of the support member. There is known a power transmission device for a vehicle that is rotatably supported on the vehicle.

  As an example of such a power transmission device, the power transmission device described in Patent Document 1 is arranged on a cylindrical composite gear integrally including a ring gear and an external gear of a planetary gear mechanism, and an axis of the planetary gear mechanism. Rotating shaft, a carrier that rotates integrally with the rotating shaft and meshes with the ring gear, and supports the pinion gear rotatably around the pinion pin, and a rolling bearing that rotatably supports the cylindrical compound gear The inner ring of the rolling bearing is externally fitted to a cylindrical support member formed in the housing.

Japanese Patent Laying-Open No. 2015-52373 JP2015-215061A

  However, if the inner ring that is externally fitted is a clearance fit with respect to the support member, for example, in a situation where the bearing is not subjected to a large load as in EV running when the engine is stopped, the inner ring slides and rotates, In a situation where a large load is applied to the bearing due to the transition to HV traveling, the inner ring is pressed against the support member, and wear due to creep may occur between the inner ring and the support member. In order to prevent the occurrence of such wear, it is conceivable to dispose an annular elastic body between the inner ring and the support member as described in Patent Document 2, for example. However, in that case, the number of parts may increase.

  Therefore, the present invention has been made in view of the above circumstances, and the object thereof is to suppress the occurrence of wear between the inner ring and the support member without causing an increase in the number of parts. It is in providing the support structure of a power transmission device.

In order to achieve this object, a support structure for a power transmission device for a vehicle according to an aspect of the present invention includes:
A cylindrical gear member having a gear on the outer peripheral side is rotatably supported by the support member with a bearing having an outer ring fitted on the inner peripheral surface of the gear member and an inner ring fitted on the outer peripheral surface of the support member. A power transmission device to support,
In the outer fitting support portion of the support member that externally supports the inner ring, a lubricating groove into which lubricating oil flows is provided in at least one of the supporting member and the inner ring, and
A bearing member that is supported by the support member and that constitutes a bearing different from the bearing extends toward the end of the lubrication groove on the downstream side in the lubricating oil flow direction,
In the outer fitting support portion, an oil sump is formed between the support member and the inner ring.

  According to the support structure for a power transmission device according to one aspect of the present invention, the lubricating oil is held by the oil sump formed between the support member and the inner ring, so that the gap between the support member and the inner ring is reduced. Generation of wear is suppressed. Moreover, since the oil sump is formed between the support member and the inner ring by using a bearing member constituting another bearing, the number of parts is not increased.

It is a skeleton figure which shows the principal part of the hybrid vehicle containing the power transmission device with which this invention is applied. It is sectional drawing which shows embodiment which applied this invention to the power transmission device shown by the skeleton figure of FIG. It is sectional drawing which follows the III-III line of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a skeleton diagram showing a main part of a hybrid vehicle including a power transmission device to which the present invention is applied. The hybrid drive device is a so-called two-motor type drive device, and includes an engine (ENG) 1 and two rotating electrical machines 2 and 3 as a driving force source. The engine 1 is an internal combustion engine such as a gasoline engine or a diesel engine, and the first rotating electrical machine 2 is preferably a motor / generator (hereinafter also referred to as MG1) capable of regenerating energy and outputting power. Further, the second rotating electrical machine 3 is also preferably a motor / generator (hereinafter also referred to as MG2). A power split mechanism that splits the power output from the engine 1 into a first rotating electrical machine (MG1) 2 and an output member is provided. The power split mechanism can be constituted by a differential mechanism such as a planetary gear mechanism. In the example shown in FIG. 1, the power split mechanism is constituted by a single pinion type planetary gear mechanism 4.

  In this planetary gear mechanism 4, a plurality of (for example, three) pinion gears 7 meshing with the sun gear 5 and the ring gear 6 are disposed between the sun gear 5 and the ring gear 6, and these pinion gears 7 are rotated by a carrier 8. And is held so that it can revolve. The structure for holding the pinion gear 7 by the carrier 8 is the same as the structure in a conventionally known planetary gear mechanism, as will be described later.

  The carrier 8 is a so-called input element, and is configured to transmit power from the engine 1. That is, the crankshaft of the engine 1 on the axis C1 and the input shaft 9 connected to the carrier 8 are connected via a damper mechanism (not shown).

  A first rotating electrical machine (MG1) 2 is disposed on the same axis (axis C1) as the engine 1 on the opposite side of the planetary gear mechanism 4. The rotor of the first rotating electrical machine 2 is connected to the sun gear 5 via the rotor shaft 2a. Therefore, the sun gear 5 is a so-called reaction force element. The rotor shaft 2a of MG1 and the sun gear shaft to which the rotor shaft 2a is connected are hollow shafts, and the pump shaft 12 is inserted into the hollow shaft. One end of the pump shaft 12 is connected to the engine 1 via the input shaft 9, and an oil pump (mechanical oil pump; MOP) 13 is connected to the other end. The MOP 13 is driven by the engine 1 to generate a hydraulic pressure for control and a hydraulic pressure for lubrication. In addition, a second oil pump (electric oil pump; EOP) (not shown) driven by an electric motor to secure the hydraulic pressure when the engine 1 is stopped is provided in parallel with the MOP 13. ing.

  Further, the ring gear 6 in the planetary gear mechanism 4 constituting the power split mechanism is a so-called output element, and the output gear which is an external gear corresponding to the output member integrally with the ring gear 6 which is the internal gear. 15 is provided. The output gear 15 is connected via a counter gear unit 16 to a differential gear device (Diff) 17 that rotates about an axis C4. That is, the driven gear 19 attached to the countershaft 18 on the shaft center C <b> 2 is engaged with the output gear 15. A drive gear 20 having a smaller diameter than the driven gear 19 is formed on or attached to the countershaft 18, and this drive gear 20 meshes with a ring gear 21 in the differential gear device 17. A driving force is output from the differential gear unit 17 to the left and right driving wheels 22. The driven gear 19 is engaged with another drive gear 23 provided on the rotor shaft 3a on the axis C3 of the second rotating electrical machine (MG2) 3. That is, the torque of the second rotating electrical machine 3 is added to the torque output from the output gear 15.

  The first rotating electrical machine 2 and the second rotating electrical machine 3 are electrically connected to each other via a power storage device or an inverter (not shown), and supply the electric power generated by the first rotating electrical machine 2 to the second rotating electrical machine 3. It is configured to be able to.

  The hybrid vehicle described above can selectively set three travel modes including a hybrid mode (HV mode), a two-motor mode, and a one-motor mode. In the HV mode, the power output from the engine 1 is divided into the first rotating electrical machine 2 side and the output gear 15 side by the power split mechanism, and the electric power generated by the first rotating electrical machine 2 functioning as a generator is rotated to the second rotation. This is a traveling mode in which the output torque of the second rotating electrical machine 3 is supplied to the electrical machine 3 and added to the torque of the output gear 15 in the counter gear unit 16. In the two-motor mode, the engine 1 is stopped, the first rotating electrical machine 2 and the second rotating electrical machine 3 are operated as a driving force source for EV traveling, and EV traveling is performed with the power of these two rotating electrical machines 2 and 3. Mode. In that case, the carrier 8 is fixed by a brake mechanism (not shown). Therefore, the power split mechanism functions as a speed reduction mechanism between the first rotating electrical machine 2 and the output gear 15. The one-motor mode is a mode in which EV traveling is performed using the second rotating electrical machine 3 as a driving force source.

  Here, an embodiment in which the present invention is applied to the power transmission device shown in the skeleton diagram of FIG. 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a configuration of a housing or a case for supporting a bearing for rotatably supporting a shaft holding a gear as a reference numeral 100 with respect to the skeleton diagram of FIG. FIG. 2 shows a part of a portion corresponding to the axis C1 in the above-described power transmission device.

  In the embodiment shown in FIG. 2, the input shaft 9, the planetary gear mechanism 4 constituting the power split mechanism, and the aforementioned ring gear 6 and output gear 15 rotating around the axis C1 are the inner circumference of the cylindrical member. A composite gear 25 integrally formed on the side and the outer peripheral side is shown, and the cylindrical composite gear 25 is supported on the housing 100 via first and second bearings 102 and 104. The planetary gear mechanism 4 includes a sun gear 5, a ring gear 6, and a carrier 8 that is integrally fixed to a flange 9 a formed on the input shaft 9 by press-fitting, welding, or the like. Is meshed with a pinion gear 7 rotatably arranged on the carrier 8. The input shaft 9 corresponds to a rotating shaft, and is supported by the housing 100 through a plurality of bearings so as to be rotatable around the axis C1, and the power of the engine 1 is transmitted to rotate around the axis C1. Is done. The shaft center C1 of the input shaft 9 corresponds to the shaft center of the planetary gear mechanism 4, and the sun gear 5 and the ring gear 6 are rotatably arranged around the shaft center C1.

  A plurality of (for example, three) pinion pins 8a are integrally fixed to the carrier 8 in parallel with the axis C1 by press-fitting, welding, or the like, and the pinion gear 7 is connected to the pinion pins 8b through a pair of needle bearings 8b. 8a is rotatably arranged. The carrier 8 is provided with a through hole, and the pinion pin 8a is integrally fixed to the carrier 8 with the axial end face being substantially flush with the side face of the carrier 8 through the through hole. Has been. The carrier 8 is provided on both sides in the axial direction across the pinion gear 7, and both end portions of the pinion pin 8 a are fixed to the carrier 8. The carriers 8 on both sides are integrally formed with each other, and the carrier 8 on the right side in the figure is integrally fixed to the input shaft 9. A flange 9a is integrally formed on the input shaft 9, and the carrier 8 is fitted to the outer peripheral side of the flange 9a and is integrally fixed. A thrust bearing 106 is disposed between the flange portion 9a and the housing 100, and their axial positions are defined in a state where the input shaft 9 and the carrier 8 can rotate about the axis C1.

  The sun gear 5 is disposed on the outer peripheral side of the input shaft 9 through a needle bearing 5a so as to be relatively rotatable, and the rotor shaft 2a of the first rotating electrical machine (MG1) 2 shown in FIG. 1 through a spline 5b. It is connected to the non-rotatable. A thrust bearing 108 is disposed between the sun gear 5 and the flange portion 9a, and a thrust bearing 110 is disposed between the sun gear 5 and the housing 100. The sun gear 5 rotates about the axis C1. The axial position is defined where possible.

  As described above, the ring gear 6 is integrally provided with the output gear 15 that is an external gear, and the ring gear 6 and the output gear 15 constitute a cylindrical composite gear 25. The output gear 15 meshes with a counter gear 19 provided on a counter shaft 18 disposed in parallel with the input shaft 9, and further from the counter shaft 18, a drive gear 20, a ring gear 21 in the differential gear device 17, and the like. Power is transmitted to the drive wheel 22 side through the wheel. The compound gear 25 protrudes outward in the axial direction from the carrier 8, and is rotatable around the axis C <b> 1 by the housing 100 via the first and second rolling bearings 102 and 104 outside the carrier 8. It is supported. The first and second rolling bearings 102 and 104 are disposed on the inner peripheral side of the end portion in the axial direction of the composite gear 25 having a cylindrical shape.

  Furthermore, a supply oil passage 30 is provided in the axis C1 of the input shaft 9 in the present embodiment, and lubricating oil is supplied from the oil pump 13 shown in FIG. The thrust bearing 106 is lubricated by the lubricating oil discharged from the first radial oil passage 30 a communicating with the supply oil passage 30, and the lubricating oil circulated to the outer peripheral side through the thrust bearing 106 is further increased. By being blown to the outer peripheral side by centrifugal force, it is received by the oil receiver 32 attached to the side surface of the carrier 8 and having the through hole 32a, and the pinion gear 7 and the second rolling bearing 104 are lubricated. Further, the needle bearing 5 a and the thrust bearing 108 are lubricated by the lubricating oil discharged from the second radial oil passage 30 b communicating with the supply oil passage 30.

  Further, in the embodiment shown in FIGS. 2 and 3, the first rolling bearing 102 described above is tightly fitted to the inner peripheral surface of the composite gear 25 whose outer ring 102a has a cylindrical shape, and the inner ring 102b is a housing. The cylindrical support member 100a is formed so as to protrude from the outer peripheral surface of the cylindrical support member 100a. The outer fitting support portion of the support member 100a that supports the inner ring 102b is provided with a lubricating groove 100b extending in the axial direction parallel to the axis C1.

  On the other hand, the thrust bearing 110 provided between the front end portion of the cylindrical support member 100a formed to protrude from the housing 100 and the sun gear 5 described above includes the rolling rollers 110b held by the cage 110a. It is formed so as to be able to roll between the left bearing race 110c and the right bearing race 110d. In the present embodiment, the left bearing race 110c has an L-shaped cross section of an inner ring portion 110ci extending in the axial direction parallel to the axis C1 and a radial ring portion 110cp extending in the radial direction orthogonal to the axis C1. It is formed with a shape. The right bearing race 110d includes an inner ring portion 110di and an outer ring portion 110do that extend in the axial direction parallel to the axis C1, and a radial ring portion that extends in the radial direction perpendicular to the axis C1 therebetween. It is formed with 110 dp.

  Here, the left bearing race 110c formed with an L-shaped cross-sectional shape is held with its inner ring portion 110ci being press-fitted into the tip end opening of the cylindrical support member 100a. On the other hand, the radial ring portion 110cp extends toward the downstream end of the lubricating groove 100b in the lubricating oil flow direction (indicated by arrow Y). Thus, the outer end portion of the radial ring portion 110cp covers the inner portion of the outlet of the lubricating groove 100b, in other words, by reducing the area of the outlet of the lubricating groove 100b, the support member 100a and the first rolling bearing 102 An oil reservoir 120 is formed between the inner ring 102b and the inner ring 102b.

  In the present embodiment configured as described above, a part of the lubricating oil that flows out from the radial oil passages 30a and 30b of the input shaft 9 and is scattered to the outer peripheral side due to centrifugal force or the like is left at the left end of the composite gear 25. Between the support member 100a and the housing 100 and flows in the direction of the arrow X, and reaches an oil sump 120 formed between the support member 100a and the inner ring 102b of the first rolling bearing 102. Therefore, even if the inner ring 102b rotates with respect to the support member 100a due to the creep of the first rolling bearing 102, the presence of the lubricating oil held in the oil reservoir 120 causes a gap between the inner ring 102b and the support member 100a. Wear is suppressed.

  In the present embodiment, the oil reservoir 120 is formed by using the left bearing race 110c that is a bearing member constituting the existing thrust bearing 110 that is a bearing different from the first rolling bearing 102. Therefore, the number of parts is not increased.

  Furthermore, another embodiment of the present invention will be described. In the above-described embodiment, the oil reservoir 120 is formed by forming the lubricating groove 100b in the support member 100a, but instead of or in addition to this, an axial lubricating groove is formed on the inner peripheral surface of the inner ring 102b. May be formed. However, in this case, in order to reduce the exit area of the lubricating groove, it is necessary to adjust the diameter of the outer end portion of the radial ring portion 110cp of the left bearing race 110c, which is a bearing member of another bearing, for example. is there.

  As mentioned above, although embodiment of this invention was described in detail based on drawing, these are one embodiment to the last, and this invention is implemented in the aspect which added the various change and improvement based on the knowledge of those skilled in the art. be able to.

4 planetary gear mechanism 5 sun gear 6 ring gear 8 carrier 9 input shaft 15 external gear (output gear)
25 compound gear 100 housing 100a support member 100b lubrication groove 102 first rolling bearing 102a outer ring 102b inner ring 110 thrust bearing 110c left bearing race 120 oil sump

Claims (1)

A cylindrical gear member having a gear on the outer peripheral side is rotatably supported by the support member with a bearing having an outer ring fitted on the inner peripheral surface of the gear member and an inner ring fitted on the outer peripheral surface of the support member. A power transmission device to support,
In the outer fitting support portion of the support member that externally supports the inner ring, a lubricating groove into which lubricating oil flows is provided in at least one of the supporting member and the inner ring, and
A bearing member that is supported by the support member and that constitutes a bearing different from the bearing extends toward the end of the lubrication groove on the downstream side in the lubricating oil flow direction,
In the outer fitting support portion, an oil sump is formed between the support member and the inner ring.

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