JP2009174629A - Vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving device capable of relieving an impact load while restraining a dimensional increase in the axial direction of a rotor shaft and an increase in the bearing number. <P>SOLUTION: This driving device 2 has a driving gear shaft 14 integrally rotatably provided with a driving gear 15, a rotor shaft 13 for installing a rotor 12 of a motor generator 4 on the outer periphery and forming a through-hole 13a capable of inserting the driving gear shaft 14 in the axis Ax direction, and a pair of bearings 21 and 22 capable of rotatably supporting the driving gear shaft 14. The driving gear shaft 14 and the rotor shaft 13 are coaxially and integrally rotatably combined so that the rotor shaft 13 is positioned between the pair of bearings 21 and 22 in a state of interposing a spline joining part 25 capable of relieving the impact load transmitted between the driving gear shaft 14 and the rotor shaft 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle drive device that can output the power of a rotating electrical machine provided as a drive source to drive wheels of a vehicle.

  A vehicle provided with a rotating electrical machine such as an electric motor or a motor generator as a drive source is well known. For example, there are an electric vehicle equipped with only an electric motor as a drive source, a hybrid vehicle equipped with an internal combustion engine as a drive source in addition to a motor generator and the like. Such a vehicle is provided with a drive device including a gear train in a power transmission path from the rotary electric machine to the drive wheel in order to output the power of the rotary electric machine to the drive wheel of the vehicle.

  By the way, when such a vehicle crosses the gap, the driving wheel that is momentarily separated from the road surface touches again, the vehicle that is traveling on the flat ground switches to traveling that climbs a steep slope, or the vehicle that has stopped on the slope in a parking lock state When the parking lock is released, an impact load from the drive wheel side toward the rotating electrical machine side may be generated in the drive device. Such an impact load includes a rotational component around the axis in addition to the radial component intersecting with the rotational axis of the rotating element in the driving device and the axial thrust component. For this reason, when an impact load is generated, load is applied to each member such as a rotor shaft on which the rotor is mounted, a drive gear that transmits the rotation of the rotor shaft, and a bearing that supports the rotor shaft due to inertia of the rotor of the rotating electrical machine.

  In order to reduce the load on each member accompanying the generation of such an impact load, it is possible to use a rotating electrical machine (Patent Document 1) in which at least one of the rotor and the rotor shaft is made of magnesium or a magnesium alloy as a base material. . There is also known a drive device in which a drive gear shaft provided with a drive gear and a rotor shaft are configured as separate parts, and the drive gear shaft is spline-coupled on the extension of the rotor shaft (Patent Document 2).

JP 2004-274968 A Japanese Patent Laid-Open No. 10-278603

  When using the rotary electric machine of patent document 1, since a rotor and a rotor axis | shaft are reduced in weight by comprising a rotor and a rotor axis | shaft as a base material, a rotor and a rotor axis | shaft reduce. Therefore, the load of each member of the drive device accompanying the impact load can be reduced. However, since magnesium or a magnesium alloy is inferior in strength to iron, it is necessary to increase the physique in order to ensure the same strength as when the rotor and the rotor shaft are made of iron. Therefore, it is difficult to efficiently reduce the inertia of the rotor. Moreover, since the drive gear shaft is coupled to the extension of the rotor shaft in the drive device of Patent Document 2, the dimension in the axial direction increases. In addition, since the splined portion cannot receive a sufficient bending moment, it is necessary to support the splined portion located on the extension of the rotor shaft with a bearing. As a result, in a state where the drive gear shaft and the rotor shaft are combined, at least three of the both ends of the combined shaft and the splined portion are supported by the bearing, and the number of bearings increases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle drive device that can alleviate an impact load while suppressing an increase in the axial dimension of the rotor shaft and an increase in the number of bearings.

  The drive device of the present invention is a vehicle drive device capable of outputting the power of a rotating electrical machine provided as a drive source to a drive wheel of a vehicle, and is disposed in a power transmission path from the rotating electrical machine to the drive wheel. A drive gear shaft provided with a drive gear so as to rotate integrally; a rotor shaft on which a rotor of the rotating electrical machine is mounted on an outer periphery; and a through-hole into which the drive gear shaft can be inserted in the direction of the axis; and A pair of bearings that can rotatably support the drive gear shaft and are arranged at a predetermined interval in the direction of the axis of the drive gear shaft, the drive gear shaft and the rotor shaft, The rotor shaft is positioned between the pair of bearings that support the drive gear shaft in a state where a low-rigidity coupling means that can reduce an impact load transmitted between the drive gear shaft and the rotor shaft is interposed. Coaxial and one By being rotatably combined to solve the problems mentioned above (claim 1).

  According to this drive device, the rotor shaft is positioned between a pair of bearings that support the drive gear shaft, and the rotor shaft and the drive gear shaft are combined coaxially and integrally rotatable. Therefore, both the rotor shaft and the drive gear shaft can be supported by a pair of bearings. Since the combination of the rotor shaft and the drive gear shaft can be supported by the pair of bearings, the number of bearings can be minimized. Furthermore, since the rotor shaft is disposed between the pair of bearings, an increase in dimension in the axial direction can be minimized. Since the rotor shaft and drive gear shaft are combined with a low-rigidity coupling means that can relieve the impact load transmitted between these shafts, even if the impact load is input to the drive gear for any reason, the coupling Due to the action of the means, the inertia considering the rigidity of the object is reduced, so the impact load is reduced. Further, since the rotor shaft and the drive gear shaft are separate, the drive gear can be easily machined without being restricted by the rotor shaft as compared with the case where these shafts are integrated. Therefore, for example, when the tooth surface of the drive gear is polished by a grinding device equipped with a rotating grindstone, it is not necessary to consider the interference between the rotor shaft and the grindstone, and the tooth surface of the drive gear 15 is polished using the grinding device. There is no problem. Therefore, the processing accuracy of the drive gear can be easily increased without increasing the number of steps. Furthermore, if these shafts are integrated, the outer diameter of the rotor is the largest, so a pair of bearings are assembled from opposite directions. However, these shafts are separate, so that the drive gear shaft, the rotor shaft And since it becomes easy to unify the direction of assembly of the bearings in one direction, the assembly procedure can be simplified.

  The low-rigidity coupling means may take various forms. For example, as the low-rigidity coupling means, external teeth that are formed on the outer periphery of the drive gear shaft and extend in the direction of the axis line are circumferential directions of the drive gear shaft. And internal teeth that are formed on the inner periphery of the rotor shaft and extend in the direction of the axis are aligned in the circumferential direction of the rotor shaft and can mesh with the outer tooth row There is provided a spline coupling portion that is capable of coaxially and integrally rotating the drive gear shaft and the rotor shaft by meshing the outer tooth row and the inner tooth row with each other. (Claim 2). According to this aspect, when an impact load is input to the drive gear shaft, the external teeth and the internal teeth that mesh with each other undergo elastic deformation, so that the impact load is reduced.

  Further, as the low-rigidity coupling means, an outer groove formed on the outer periphery of the drive gear shaft and extending in the direction of the axis, an inner groove formed on the inner periphery of the rotor shaft and extending in the direction of the axis, and An interposition member that is fitted in each of the outer groove and the inner groove facing each other and is made of a low-rigidity material that is lower in rigidity than the constituent material of the drive gear shaft. By interposing between the drive gear shaft and the rotor shaft so as to fit in each of the groove and the inner groove, the drive gear shaft and the rotor shaft can be combined coaxially and integrally rotatable. A rigid coupling portion may be provided (claim 3). According to this aspect, when an impact load is input to the drive gear shaft, the interposed member is elastically deformed, so that the impact load is reduced.

  The low-rigidity coupling portion further includes an outer groove row in which the outer grooves are arranged in the circumferential direction of the drive gear shaft, and an inner groove row in which the inner grooves are arranged in the circumferential direction of the rotor shaft, You may provide the some fitting part fitted to each outer groove of the said outer groove row | line | column of the state which mutually opposed, and each inner groove of the said inner groove row | line | column (Claim 4). In this case, the load input to the interposition member by the plurality of fitting portions is dispersed in the circumferential direction without concentrating on one point, so that the impact load can be effectively reduced. The plurality of fitting portions may be separate from each other, but the interposition member may further include a connection portion that connects the plurality of fitting portions to each other (Claim 5). In this case, since the plurality of fitting portions are connected to each other via the connection portion, the plurality of independent fitting portions are fitted into the outer grooves and the inner grooves in a state of facing each other one by one. There is an advantage that assembly is easier than in the case.

  In one aspect of the present invention, a parking gear disposed in the power transmission path between the driving gear and the driving wheel, and an engagement position that meshes with the parking gear and restrains the parking gear so as not to rotate. And a parking lock mechanism which can move between the parking gear and an open position where the rotation of the parking gear is released (Claim 6). When the vehicle is stopped on the slope, when the parking gear is engaged with the parking pole, the rotating element such as the gear in the power transmission path is locked, and torque is input from the drive wheel side due to the weight of the vehicle. Therefore, each element from the parking gear to the drive wheel is twisted. In this state, when the parking pole is moved to the release position away from the parking gear and the lock is released, the twist is released, and an impact load is generated in the power transmission path. According to this aspect, the impact load generated in such a situation can be effectively reduced by the low-rigidity coupling means interposed between the rotor shaft and the drive gear shaft.

  The parking gear may be provided at any position in the power transmission path. For example, the parking gear further includes a driven gear shaft that is rotatably provided with a driven gear that meshes with the drive gear, and the parking gear includes the driven gear. The shaft may be provided so as to be integrally rotatable (claim 7). In this case, as described above, when the parking lock is released and the twist is released, the driven gear collides with the drive gear and an impact load is generated. The load input to the pair of bearings increases from the balance of force as the distance between the bearing closer to the drive gear and the drive gear increases. As described above, since the drive gear according to the present invention is separated from the rotor shaft and the drive gear shaft, the machining thereof is not restricted, so that the bearing near the drive gear and the drive gear can be brought close to the limit. it can. According to this aspect, compared with the aspect in which the rotor shaft and the drive gear shaft are integrated to ensure the distance between the bearing and the drive gear on the side close to the drive gear for processing the drive gear, Since there is no restriction on reducing the distance between the bearing and the drive gear, the load input to the pair of bearings can be easily reduced while suppressing an increase in the dimension in the direction of the axis.

  As described above, according to the present invention, the rotor shaft is positioned between the pair of bearings that support the drive gear shaft, and the rotor shaft and the drive gear shaft are combined coaxially and integrally rotatable. Therefore, both the rotor shaft and the drive gear shaft can be supported by a pair of bearings. Since the combination of the rotor shaft and the drive gear shaft can be supported by the pair of bearings, the number of bearings can be minimized. Furthermore, since the rotor shaft is disposed between the pair of bearings, an increase in dimension in the axial direction can be minimized. Since the rotor shaft and drive gear shaft are combined with a low-rigidity coupling means that can relieve the impact load transmitted between these shafts, even if the impact load is input to the drive gear for any reason, the coupling Since the total inertia force of the drive gear shaft and the rotor shaft is reduced by the action of the means, the impact load is reduced.

(First form)
FIG. 1 schematically shows the overall configuration of a vehicle in which a drive device according to an embodiment of the present invention is incorporated. The vehicle 1 is configured as a so-called hybrid vehicle. As is well known, a hybrid vehicle is a vehicle having an internal combustion engine as a driving source for traveling and a rotating electrical machine such as a motor generator as another driving source for traveling, and driving the internal combustion engine as efficiently as possible. On the other hand, by compensating for excess or deficiency of the driving force and engine braking force with other driving sources and regenerating energy during vehicle deceleration, etc., it is possible to prevent deterioration of internal combustion engine emissions and improve fuel efficiency. It is configured to be realized.

  The vehicle 1 is provided with a driving device 2 for traveling. The drive device 2 includes an internal combustion engine 3 and two (only one shown in the figure) motor generator 4 as a driving source for traveling, and combines the power (output torque) of each of the internal combustion engine 3 and the motor generator 4. Then, it is configured to output to the propeller shaft 5, and to output the torque of the propeller shaft 5 to the left and right drive wheels 7 via the differential device 6. The synthesis or separation of the output torques of the internal combustion engine 3 and the motor generator 4 is performed by a known power distribution mechanism (not shown) constituted by a planetary gear mechanism. Note that various rotation elements such as a gear train and a clutch constituting a speed change mechanism are provided in the power transmission path from the internal combustion engine 3 or the motor generator 4 to the drive wheels 7, but FIG. Only the configuration with high relevance is shown, and the power transmission path related to the configuration not shown is indicated by a broken line.

  The motor generator 4 is configured to generate a function as an electric motor and a function as a generator. A battery (not shown) is electrically connected to the motor generator 4 via an inverter (not shown), and the output torque or regenerative torque of the motor generator 4 is appropriately set by controlling the inverter. The motor generator 4 includes a stator 11 fixed to a casing 10 attached to the vehicle 1 so as not to rotate, and a rotor 12 disposed coaxially on the inner peripheral side of the stator 11. The rotor 12 is mounted on the outer periphery of the rotor shaft 13, and the rotor shaft 13 is combined with the drive gear shaft 14 so as to be coaxial and integrally rotatable. A drive gear 15 is provided at the end of the drive gear shaft 14 so as to be integrally rotatable. The drive gear 15 is configured as a helical gear and is disposed in a power transmission path from the motor generator 4 to the drive wheel 7. The drive gear 15 meshes with the driven gear 16, and the driven gear 16 is provided on a driven gear shaft 17 that extends parallel to the drive gear shaft 14 so as to be integrally rotatable.

  FIG. 2 shows a main part of the driving device 2 related to the periphery of the motor generator 4. As shown in the figure, the drive device 2 has a pair of bearings 21 and 22 that can rotatably support the drive gear shaft 14 and are arranged at a predetermined interval in the direction of the axis Ax of the drive gear shaft 14. . Each of the bearings 21 and 22 is configured as a ball bearing in which a steel ball is interposed between the inner and outer rings. The outer ring is in contact with the casing 10 and the inner ring is in contact with a journal portion 14 a formed on the outer periphery of the drive gear shaft 14. A rotor shaft 13 is disposed between the pair of bearings 21 and 22. The rotor shaft 13 is formed with a through hole 13a into which the drive gear shaft 14 can be inserted in the direction of the axis Ax, and the drive gear shaft 14 is inserted into the through hole 13a. The rotor shaft 13 and the drive gear shaft 14 are combined so as to be coaxial and integrally rotatable with a spline coupling portion 25 interposed therebetween. Thus, since the combination of the rotor shaft 21 and the drive gear shaft 22 can be supported by the pair of bearings 21 and 22, the number of bearings can be minimized. In addition, since the rotor shaft 13 is disposed between the pair of bearings 21 and 22, an increase in dimension in the direction of the axis Ax can be minimized.

  FIG. 3 shows an enlarged view of a part of the spline coupling portion 25 as viewed from the direction of the axis Ax. The spline coupling portion 25 includes an external tooth row 26 in which outer teeth 26 a formed on the outer periphery of the drive gear shaft 14 are arranged in the circumferential direction of the drive gear shaft 14, and an inner tooth 27 a formed on the inner periphery of the rotor shaft 13. The inner tooth row 27 is arranged in the 13 circumferential directions and can mesh with the outer tooth row 26. The teeth of each of the outer teeth 26a and the inner teeth 27a extend in the direction of the axis Ax over substantially the entire length of the rotor shaft 13. The spline coupling portion 25 can combine the drive gear shaft 14 and the rotor shaft 13 so as to be coaxially and integrally rotatable by meshing the outer tooth row 26 and the inner tooth row 27 with each other. Since the rotor shaft 13 and the drive gear shaft 14 are combined via the spline coupling portion 25, if excessive torque is input to either the rotor shaft 13 or the drive gear shaft 14, the spline coupling portion 25 Excessive torque transmitted between the rotor shaft 13 and the drive gear shaft 14 can be reduced by elastically deforming the outer tooth row 26 and the inner tooth row 27, respectively.

  As shown in FIG. 1, a parking lock mechanism 30 for locking the drive device 2 when the vehicle 1 stops is provided in the power transmission path from the motor generator 4 to the drive wheels 7. The parking lock mechanism 30 includes a parking gear 31 provided on the driven gear shaft 17 so as to be integrally rotatable, and a parking pole 32 that meshes with the parking gear 31 and can restrain the parking gear 31. FIG. 4 shows the parking lock mechanism 30 as viewed from the axial direction of the driven gear shaft 17. As shown in the figure, the parking gear 31 is formed with a plurality of recesses 31a arranged at equal intervals in the circumferential direction. The parking pole 32 is rotatably supported with respect to the casing 10 by a support shaft 32a. The parking pole 32 has a convex portion 32 b that fits into the concave portion 31 a of the parking gear 31. The parking pole 32 can rotate between an engagement position indicated by a solid line and an open position indicated by an imaginary line. When the parking pole 32 is located at the engaging position, the convex portion 32b is engaged with the concave portion 31a of the parking gear 31 and meshes with the parking gear 31, thereby restraining the parking gear 31 so that it cannot rotate. On the other hand, when the parking pole 32 is located at the open position, the convex portion 32b is detached from the concave portion 31a, thereby leaving the parking gear 31 and releasing the rotation of the parking gear 31. The movement of the parking pole 32 between the engagement position and the release position is performed by a drive mechanism (not shown).

  As is clear from FIG. 1, when the vehicle 1 is stopped on the slope with the drive device 2 locked by the parking lock mechanism 30, torque is input from the drive wheel 7 side due to the weight of the vehicle 1. Each element in the power transmission path from the parking gear 31 to the drive wheel 7 is twisted. In this state, when the parking pole 32 is separated from the parking gear 31 and is unlocked, the twist is released, and the driven gear 16 collides with the drive gear 15 to generate an impact load. The rotational component of the impact load is alleviated by the action of the spline coupling portion 25. That is, the spline coupling part 25 functions as a low-rigidity coupling means according to the present invention. The other components are borne by the pair of bearings 21 and 22 that support the drive gear shaft 14 as shown in FIG. FIG. 5 is an explanatory diagram for explaining the action of the impact load. As shown in the figure, the impact load F acting on the drive gear 15 is divided into a thrust component Fs in the direction of the axis Ax and a radial component Fr in the radial direction because the drive gear 15 is configured as a helical gear. For this reason, the bearings 21 and 22 are loaded with the thrust component Fs in the direction of the axis Ax and F1r and F2r, which are the reaction forces of the radial radial component Fr intersecting the axis Ax, respectively. F1r and F2r are respectively expressed by the following formulas 1 and 2 from the relationship of force balance, where L1 is the distance between the drive gear 15 and the bearing 21 on the side closer thereto, and L2 is the distance between the bearings 21 and 22. It is.

F1r = (L1 + L2) / L2 × Fr ............ 1
F2r = L1 / L2 × Fr 2

  As is clear from these equations, when the distance L2 between the bearings 21 and 22 is constant, the load on the bearings 21 and 22 increases as the distance L1 between the drive gear 15 and the bearing 21 increases. By the way, since the drive gear 15 is separated from the rotor shaft 13 and the drive gear shaft 14 and is not restricted by the machining, the bearing 21 and the drive gear 15 close to the drive gear 15 can be brought close to the limit. it can. That is, in the case where the rotor shaft 13 and the drive gear shaft 14 are integrated, the distance L1 between the bearing 21 and the drive gear 15 must be secured to some extent for machining the drive gear 15, but this In the case of the embodiment, the distance L1 can be shortened without being restricted by gear processing. Accordingly, since there is no restriction on reducing the distance L1 between the bearing 21 and the drive gear 15, the loads F1r and F2r input to the pair of bearings 21 and 22 can be easily reduced while suppressing an increase in the dimension in the direction of the axis Ax. .

  Further, since the rotor shaft 13 and the drive gear shaft 14 are separate, the drive gear 15 can be easily machined without being restricted by the rotor shaft 13 before they are combined. For example, when the tooth surface of the drive gear 15 is polished by a grinding device equipped with a rotating grindstone, it is not necessary to consider the interference between the rotor shaft 13 and the grindstone, and the tooth surface of the drive gear 15 is polished using the grinding device. There is no problem. Therefore, the processing accuracy of the drive gear 15 can be easily increased without increasing the number of steps. Further, when these shafts 13 and 14 are integrated, the outer diameter of the rotor 12 becomes the largest, so that the pair of bearings 21 and 22 are assembled from opposite directions. However, since the shafts 13 and 14 are separate from each other in the illustrated form, the assembly direction of the drive gear shaft 14, the rotor shaft 13, and the bearings 21 and 22 is set to one direction (right direction in FIG. 2). Since it can be unified, the assembly procedure can be simplified.

(Second form)
Next, a second embodiment of the present invention will be described. The second form corresponds to a modification of the first form and is common to the first form except for the form of coupling of the rotor shaft and the drive gear shaft. Therefore, the same reference numerals are given to the configurations common to the first embodiment in FIGS. 6 and 7, and the description thereof is omitted, and FIGS. 1 and 4 are appropriately referred to for the other configurations.

  FIG. 6 shows a main part of the driving device 2 according to the second embodiment. In this embodiment, the rotor shaft 13 and the drive gear shaft 14 are combined so as to be coaxial and integrally rotatable with the low-rigidity coupling portion 35 interposed therebetween. FIG. 7 shows an enlarged view of a part of the low-rigidity coupling portion 35 as viewed from the direction of the axis Ax. The low-rigidity coupling portion 35 has an outer groove row 36a formed on the outer periphery of the drive gear shaft 14 in the circumferential direction of the drive gear shaft 14 and an inner groove 37a formed on the inner periphery of the rotor shaft 13 as a rotor. An inner groove row 37 arranged in the circumferential direction of the shaft 13 and an interposition member 38 that fits into the respective grooves 36a and 37a of these groove rows 36 and 37 are provided. Each of the outer groove 36 a and the inner groove 37 a extends in the direction of the axis Ax over substantially the entire length of the rotor shaft 13.

  The interposition member 38 is made of a low-rigidity material that is less rigid than the constituent material of the drive gear shaft 14. As the low-rigidity material, for example, when the drive gear shaft 14 is made of iron or an iron alloy, a metal material such as magnesium, aluminum, or an alloy thereof having lower rigidity can be selected. The low-rigidity material is not necessarily a metal material, and a non-metallic material such as rubber can be selected as the low-rigidity material. When the drive gear shaft 14 and the rotor shaft 13 are made of different materials, a material having the same or lower rigidity as the constituent material of the rotor shaft 13 may be selected as the low-rigidity material. The interposition member 38 includes a plurality of fitting portions 38a that fit into the outer groove 36a and the inner groove 37a facing each other, and a connection portion 38b that connects the plurality of fitting portions 38a to each other. The connecting portion 38 b is cylindrical and is inserted between the rotor shaft 13 and the drive gear shaft 14.

  According to this embodiment, when an impact load is input to the drive gear shaft 14, the interposed member 38 is elastically deformed, so that the impact load is reduced. That is, the low-rigidity coupling part 35 functions as the low-rigidity coupling means according to the present invention. Further, in the illustrated form, the interposition member 38 includes a plurality of fitting portions 38a, so that the load input to the interposition member 38 is dispersed in the circumferential direction without concentrating on one point. For this reason, an impact load can be relieved effectively. Furthermore, since the plurality of fitting portions 38a are connected to each other at the connection portion 38b, the plurality of independent fitting portions 38a are fitted into the outer grooves 36a and the inner grooves 37a in a state of facing each other one by one. There is an advantage that the assembling is easy compared to the case of mounting.

  The present invention is not limited to the above embodiments, and can be implemented in various forms within the scope of the gist of the present invention. The cause of the impact load generated in the drive device is not limited to that due to the release of the parking lock as described above. For example, an impact load can also be generated when the drive wheel 7 that is away from the road surface for a moment when the vehicle 1 exceeds the gap, or when the vehicle 1 traveling on the flat ground is switched to traveling on a steep slope. The drive device according to the present invention can alleviate the impact load caused by these causes. Note that the parking lock mechanism mounting location may be set anywhere within the power transmission path from the drive gear shaft to the drive wheels.

  The present invention can be applied to any vehicle in which a rotating electrical machine is mounted as a drive source. Therefore, the present invention can be applied not only to the hybrid vehicle described above, but also to an electric vehicle in which an electric motor as a rotating electric machine is mounted as a driving source without mounting an internal combustion engine as a driving source for traveling. The rotating electrical machine is not limited to a motor generator, but may function only as an electric motor.

  The form of the spline coupling portion 25 of the first form is an example, and the shape and the like of the dentition can be appropriately changed. For example, in addition to the shape of a so-called square spline as shown in the figure, a tooth row having a shape such as an involute spline or a serration may be formed.

  The form of the low-rigidity coupling portion 35 of the second form is only an example. For example, it is not excluded that a single outer groove is formed on the drive gear shaft and a single inner groove is formed on the rotor shaft, and a single interposition member is fitted in these grooves facing each other. Further, as shown in the figure, the plurality of fitting portions are not limited to being connected to each other, and the plurality of independent fitting portions are fitted into the outer grooves and the inner grooves in a state of facing each other one by one. It is also possible to implement in the form.

The figure which showed typically the whole structure of the vehicle incorporating the drive device which concerns on one form of this invention. The figure which showed the principal part of the drive device relevant to the periphery of a motor generator. The figure which expanded and showed the state which looked at a part of spline coupling | bond part from the direction of the axis line. The figure which showed the state which looked at the parking lock mechanism 30 from the axial direction of the driven gear shaft 17. FIG. Explanatory drawing explaining the effect | action of an impact load. The figure which showed the principal part of the drive device which concerns on a 2nd form. The figure which expanded and showed the state which looked at a part of low rigid coupling | bond part from the direction of the axis line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive device 4 Motor generator (rotary electric machine)
7 Drive Wheel 12 Rotor 13 Rotor Shaft 13a Through Hole 14 Drive Gear Shaft 15 Drive Gear 16 Driven Gear 17 Driven Gear Shafts 21 and 22 Bearing 25 Spline Joint (Low-Rigid Coupling Means)
26 External tooth row 26a External tooth 27 Internal tooth row 27a Internal tooth 30 Parking lock mechanism 31 Parking gear 32 Parking pole 35 Low-rigidity coupling portion (low-rigidity coupling means)
36 outer groove row 36a outer groove 37 inner groove row 37a inner groove 38 interposition member 38a fitting portion 38b connecting portion Ax axis

Claims (7)

A vehicle drive device capable of outputting the power of a rotating electrical machine provided as a drive source to a drive wheel of a vehicle,
A drive gear shaft provided in a power transmission path from the rotating electrical machine to the drive wheel so as to be integrally rotatable, a rotor of the rotating electrical machine is mounted on the outer periphery, and the drive gear shaft is an axis line A pair of rotor shafts formed with through-holes that can be inserted in the direction of the shaft and a pair of shafts that can rotatably support the drive gear shaft and that are arranged at predetermined intervals in the direction of the axis of the drive gear shaft A bearing,
The pair of drive gear shafts and the rotor shafts support the drive gear shafts with low-rigidity coupling means that can relieve an impact load transmitted between the drive gear shafts and the rotor shafts. A vehicle drive apparatus, wherein the rotor shaft is coaxially and integrally rotated so that the rotor shaft is positioned between the bearings.   As the low-rigidity coupling means, external teeth formed on the outer periphery of the drive gear shaft and extending in the direction of the axis line external teeth arranged in the circumferential direction of the drive gear shaft, and the inner periphery of the rotor shaft An inner tooth row that is formed and has teeth that extend in the direction of the axis line in the circumferential direction of the rotor shaft and can mesh with the outer tooth row, and the outer tooth row and the inner tooth 2. The drive device according to claim 1, wherein a spline coupling portion capable of combining the drive gear shaft and the rotor shaft so as to be coaxially and integrally rotatable by meshing the rows with each other is provided.   As the low-rigidity coupling means, an outer groove formed on the outer periphery of the drive gear shaft and extending in the direction of the axis, and an inner groove formed on the inner periphery of the rotor shaft and extending in the direction of the axis are opposed to each other. An intermediate member that is fitted in each of the outer groove and the inner groove in a state and is made of a low-rigidity material that is lower in rigidity than the constituent material of the drive gear shaft, the intermediate member being the outer groove and A low-rigidity coupling in which the drive gear shaft and the rotor shaft can be combined coaxially and integrally rotated by being interposed between the drive gear shaft and the rotor shaft so as to fit in each of the inner grooves. The drive device according to claim 1, wherein a portion is provided. The low-rigidity coupling portion further includes an outer groove row in which the outer grooves are arranged in the circumferential direction of the drive gear shaft, and an inner groove row in which the inner grooves are arranged in the circumferential direction of the rotor shaft,
4. The drive device according to claim 3, wherein the interposition member includes a plurality of fitting portions that are fitted into the outer grooves of the outer groove row and the inner grooves of the inner groove row that face each other.   The drive device according to claim 4, wherein the interposition member further includes a connection portion that connects the plurality of fitting portions to each other.   A parking gear disposed in the power transmission path from the drive gear to the drive wheel, an engagement position that meshes with the parking gear and restrains the parking gear so as to be non-rotatable, and away from the parking gear. The drive device according to any one of claims 1 to 5, further comprising a parking lock mechanism having a parking pawl that can move between an open position that releases rotation of the parking gear.   The drive device according to claim 6, further comprising a driven gear shaft in which a driven gear that meshes with the drive gear is provided so as to be integrally rotatable, and the parking gear is provided so as to be integrally rotatable on the driven gear shaft.

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