JP2007205466A - Vehicular power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular power transmission device with an axially compact reduction mechanism. <P>SOLUTION: The vehicular power transmission device comprises an electric motor, the reduction mechanism composed of a plurality of gear sets for reducing a driving force of the electric motor, a differential device for distributing the driving force reduced by the reduction mechanism to right and left driving wheels, and a driving force engaging/disengaging mechanism arranged on at least one of the reduction mechanism and the differential device. The reduction ratio of the gear set on the downstream side of the driving force engaging/disengaging mechanism is set to be greater than the reduction ratio of the gear set on the upstream side of the driving force engaging/disengaging mechanism. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle power transmission device that transmits a driving force of an electric motor to driving wheels via a speed reduction mechanism and a differential device.

  As this type of conventional technology, there is a vehicle power transmission device disclosed in, for example, Japanese Patent Laid-Open No. 2001-287550. The vehicle power transmission device includes a reduction mechanism that decelerates the driving force of the electric motor and a differential device that distributes the reduced driving force to the drive wheels, and is connected to at least one of the reduction mechanism and the differential device. The mechanism is arranged.

The reduction mechanism is composed of a plurality of reduction gear sets, and the driving force connecting / disconnecting mechanism is provided coaxially with the reduction gear set from the most differential gear among the reduction gear sets of the reduction mechanism.
JP 2001-287550 A

  In the power transmission device disclosed in Patent Document 1, since the speed reduction mechanism for reducing the driving force of the motor and the driving force connecting / disconnecting mechanism are housed on the side surface of the motor main body, there is a problem of taking up space in the axial direction. is there.

  Further, since the driving force connection / disconnection mechanism is on the downstream side in the power transmission path, the reduction ratio to the driving force connection / disconnection mechanism is increased. Therefore, it is necessary to increase the capacity of the driving force connecting / disconnecting mechanism, and there are problems that the mountability is deteriorated and the cost and weight are increased.

  The present invention has been made in view of these points, and an object of the present invention is to provide a vehicle power transmission device having a compact speed reduction mechanism in the axial direction.

  According to the first aspect of the present invention, an electric motor, a speed reduction mechanism including a plurality of gear sets that reduce the driving force of the electric motor, and a differential that distributes the driving force reduced by the speed reduction mechanism to the left and right drive wheels. A power transmission device for a vehicle comprising a device, and a driving force connection / disconnection mechanism disposed in at least one of the speed reduction mechanism and the differential device, a reduction ratio of a gear set downstream of the driving force connection / disconnection mechanism, There is provided a vehicle power transmission device characterized in that it is set to be larger than a reduction ratio of a gear set upstream of the driving force connecting / disconnecting mechanism.

  According to a second aspect of the invention, in the first aspect of the invention, a final drive gear for driving a ring gear of the differential device is further provided, and the driving force connecting / disconnecting mechanism is substantially the same in the axial direction as the final drive gear. Provided is a vehicle power transmission device that is disposed at a position.

  According to the first aspect of the present invention, the reduction ratio of the gear set downstream of the driving force connection / disconnection mechanism is set larger than the reduction ratio of the gear set upstream of the driving force connection / disconnection mechanism. The driving force up to the mechanism can be reduced, and the inertial mass from the electric motor can be reduced, so the capacity of the driving force connecting / disconnecting mechanism can be reduced, the mountability is improved, and the cost and weight are reduced. Can be lowered.

  According to the second aspect of the present invention, since the driving force connecting / disconnecting mechanism is disposed at substantially the same position in the axial direction as the final drive gear, the speed reducing mechanism is compact in the axial direction and mountability is improved.

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

  FIG. 1 is an overall configuration diagram in which the power transmission device of the present invention is applied to a hybrid vehicle. The automatic transmission 6 has a main shaft 8, a counter shaft 10, a first intermediate shaft 12, and a second intermediate shaft 14 that extend in parallel to each other.

  The power of the engine 2 is transmitted to the main shaft 8 of the transmission 6 via the torque converter 4. On the main shaft 8, a main drive gear 16, a 4-speed drive gear 18, a 4-speed clutch 20, a 5-speed-reverse clutch 22, a 5-speed drive gear 24, and a reverse drive gear 26 are provided in this order from the engine 2 side. .

  Here, the main drive gear 16 is provided fixed to the main shaft 8 (incapable of relative rotation), and all of the fourth speed drive gear 18, the fifth speed drive gear 24 and the reverse drive gear 26 are provided in the main shaft 8. Is provided so as to be free to rotate (relatively rotatable).

  On the first intermediate shaft 12, a second speed clutch 28, a second speed drive gear 30, a connected driven gear 32, a first speed drive gear 34, a first speed clutch 36, and a first speed holding clutch 38 are provided in order from the engine 2 side. Yes.

  Here, both the second-speed drive gear 30 and the first-speed drive gear 34 are provided so as to be free to rotate with respect to the first intermediate shaft 12, and the coupled driven gear 32 is provided fixed to the first intermediate shaft 12. It has been.

  When the first speed clutch 36 is engaged, the first speed drive gear 34 is fixed to the first intermediate shaft 12 via the one-way clutch 40. When it is desired to apply the engine brake, the first-speed drive gear 34 is fixed to the first intermediate shaft 12 by engaging the first-speed holding clutch 38 instead of the first-speed clutch 36.

  On the 2nd intermediate shaft 14, the 3rd speed clutch 42, the 3rd speed drive gear 44, and the connection gear 46 are provided in order from the engine 2 side. Here, the third speed drive gear 44 is provided so as to be free to rotate with respect to the second intermediate shaft 14, and the connection gear 46 is fixed to the second intermediate shaft 14.

  On the countershaft 10, the final drive gear 48, the second speed driven gear 50, the connected idler gear 52, the first speed driven gear 54, the third speed driven gear 56, the fifth speed driven gear 58, and the reverse driven gear are sequentially arranged from the engine 2 side. 60 is provided.

  Here, the final drive gear 48, the second speed driven gear 50, the first speed driven gear 54, and the third and fourth speed driven gear 56 are fixed with respect to the counter shaft 10, and are connected to the idler gear 52, the fifth speed driven gear 58 and the reverse. The driven gear 60 is provided so as to be free to rotate with respect to the counter shaft 10.

  Reference numeral 62 denotes a 5-speed-reverse selector mechanism (5-speed-reverse switching dog), and a 5-speed driven gear 58 is coupled to the countershaft 10 in the illustrated state. When the selector mechanism 62 is moved to the left, the fifth speed driven gear 58 idles with respect to the counter shaft 10, and the reverse driven gear 60 is coupled to the counter shaft 10. The driving force of the reverse drive gear 26 is transmitted to the reverse driven gear 60 via the reverse idle gear 64.

  A final drive gear 48 fixedly provided on the countershaft 10 meshes with a final driven gear (ring gear) 68 of a differential device 66 as indicated by reference numeral 65. Therefore, the automatic transmission 6 converts the rotational speed and torque of the engine 2 and transmits the rotational power of the engine 2 to the left and right drive wheels 70 via the differential device 66.

  On the other hand, the driving force of the electric motor 70 is also transmitted to the final driven gear 68 of the differential device 66 via the speed reduction mechanism 72.

  Next, with reference to FIG.2 and FIG.3, the connection structure of the electric motor 70 and the deceleration mechanism 72 is demonstrated. The electric motor 70 is attached to the transmission case 74 by a plurality of bolts 76. A speed reducer case 78 of the speed reduction mechanism 72 is fixed to the transmission case 74 by a plurality of bolts 80.

  An annular stator 84 is attached to the motor housing 82 of the motor 70. A rotor 86 is rotatably provided on the inner peripheral side of the stator 84. The rotor 86 is fixed to a hollow motor shaft 88, and the motor shaft 88 is rotatably supported on the motor housing 82 by a pair of bearings 90 and 92. The inside of the motor 70 is sealed with a pair of seals 94 and 96.

  An inner peripheral spline 98 is formed at the end of the motor shaft 88 opposite to the speed reduction mechanism 72. Similarly, a hollow power transmission shaft 100 is inserted into the hollow motor shaft 88, and splines 102 and 104 are formed on the outer periphery of both ends of the power transmission shaft 100. Each of the splines 102 and 104 is crowned.

  Reference numeral 106 denotes a drive gear of the speed reduction mechanism 72, and an inner peripheral spline 108 is formed. The power transmission shaft 100 is splined to the motor shaft 88 of the motor 70 at its left end and splined to the drive gear 106 of the speed reduction mechanism 72 at its right end.

  The drive gear 106 is rotatably supported by a reduction gear case 78 by a pair of bearings 110 and 112. The drive gear 106 meshes with an idle gear 114 that is rotatably supported by a pair of bearings 116 and 118.

  According to the coupling structure of the motor 70 and the speed reduction mechanism 72 according to the present embodiment, the hollow power transmission shaft 100 is similarly inserted into the hollow motor shaft 88, and the splines 102 and 104 are crowned at both ends of the power transmission shaft 100. And the power transmission shaft 100 is spline-coupled to the motor shaft 88 on the opposite side of the speed reduction mechanism 72 and spline-coupled to the drive gear 106 of the speed reduction mechanism 72 on the speed reduction mechanism 72 side. Even when the shaft deviation between the motor shaft 88 and the drive gear 106 of the speed reduction mechanism 72 occurs due to an attachment error or the like, the power transmission shaft 100 can be assembled by tilting, and power can be transmitted without damaging the spline.

  Further, the motor shaft 88 is hollow and the power transmission shaft 100 is inserted into the motor shaft 88, and the power transmission shaft 100 is splined to the motor shaft 88 on the side opposite to the speed reduction mechanism 72. Compared with the case where the shaft is splined to the motor shaft, the overall length in the axial direction can be shortened.

  Further, by supplying lubricating oil into the hollow hole 101 of the power transmission shaft 100 from the speed reduction mechanism 72 side, the bearings 110 and 112 and the splines 104 and 108 are lubricated first, and then the motor side spline 102 of the power transmission shaft 100 is lubricated. The inner peripheral spline 98 and the bearing 90 of the motor shaft 88 are lubricated.

  The lubricating oil passes through the splines 98 and 102, passes through the space 103 between the power transmission shaft 100 and the motor shaft 88, is returned to the speed reduction mechanism 72, lubricates the bearing 92, and is returned to the speed reduction mechanism 72.

  By adopting such a lubricating structure, the lubricating oil inlet and outlet of the motor housing 82 can be eliminated. In addition, the number of parts such as an oil pump can be reduced and the lubricating oil path can be simplified as compared to the case where the lubricating oil paths for the motor side and the speed reduction mechanism side are installed. Furthermore, the rotor 86 can be effectively cooled by flowing lubricating oil through the motor shaft 88 that is in contact with the rotor 86.

  Next, the speed reduction mechanism 72 and the driving force connection / disconnection mechanism 138 according to the embodiment of the present invention will be described in detail with reference to FIG.

  The reduction mechanism 72 includes an idle gear set 120 and a secondary gear set 122. The idle gear set 120 is disposed on the upstream side of the driving force connection / disconnection mechanism 138, and the secondary gear set 122 is disposed on the downstream side of the driving force connection / disconnection mechanism 138.

  The idle gear set 120 includes a drive gear 106, an idler gear 114 that meshes with the drive gear 106, and a driven gear 124 that meshes with the idler gear 114. The idler gear 114 is rotatably supported by a pair of bearings 116 and 118, and the driven gear 124 is rotatably supported by a pair of bearings 126 and 128.

  The secondary gear set 122 includes a drive gear 136 that is rotatably attached to the hollow shaft 130 and a driven gear 152 that meshes with the drive gear 136. Reference numeral 144 denotes an oil guide. Lubricating oil is supplied into the hollow shaft 130 via the oil guide 144 to lubricate the portions requiring lubrication.

  The reduction ratio of the secondary gear set 122 is set larger than the reduction ratio of the idle gear set 120. As a result, the driving force up to the driving force connecting / disconnecting mechanism 138 can be reduced, and the inertial mass from the motor 70 can be reduced, so that the capacity of the driving force connecting / disconnecting mechanism 138 can be reduced. The mountability is improved, and the cost and weight can be reduced.

  The hollow shaft 130 is rotatably supported by the transmission case 74 by a pair of bearings 132 and 134. A driving force connecting / disconnecting mechanism 138 is provided adjacent to the drive gear 136 of the secondary gear set 122.

  The driving force connecting / disconnecting mechanism 138 has the same structure as the synchro mechanism used in the manual transmission (MT), and is capable of moving in the axial direction with respect to the synchro hub 140 splined to the shaft 130 and the synchro hub 140. A sync sleeve 142 is included.

  A motor (not shown) is driven according to the running condition of the vehicle, and the sync sleeve 142 is moved to the drive gear 136 side via the shift fork by this motor, so that the drive gear 136 of the secondary gear set 122 causes the drive force connecting / disconnecting mechanism 138 to move. Via the shaft 130.

  When the driving force of the electric motor 70 is not necessary, the drive gear 136 of the secondary gear set 122 is idled with respect to the shaft 130 by moving the synchro sleeve 142 of the driving force connecting / disconnecting mechanism 138 in the left direction. The driving force of the electric motor 70 is prevented from being transmitted to the differential device 66.

  The driven gear 152 of the secondary gear set 122 is splined to the shaft 146, and the final drive gear 154 is formed integrally with the shaft 146. The shaft 146 is rotatably supported by the transmission case 74 by a pair of bearings 148 and 150. The final drive gear 154 meshes with a ring gear (final driven gear) 68 of the differential device 66.

  According to the power transmission device of this embodiment, the idle gear set 120 of the speed reduction mechanism 72 is arranged on the side surface of the motor 70, and the secondary gear set 122 is arranged between the idle gear set 120 and the final drive gear 154.

  Furthermore, by providing a driving force connecting / disconnecting mechanism 138 on the drive gear 136 of the secondary gear set 122 and setting the driving force connecting / disconnecting mechanism 138 so as not to overlap the outer diameter of the motor 70, the projection surface in the motor axial direction is provided. Since only the idle gear set 120 is provided, the axial direction becomes compact.

  Further, since the secondary gear set 122 is located adjacent to the final drive gear 154, and there is a space in the radial direction of the final drive gear 154, the driving force connecting / disconnecting mechanism 138 is approximately at the same position in the axial direction as the final drive gear 154. By arranging them, that is, by arranging them in alignment in the axial direction, the speed reduction mechanism 72 can be configured compactly in the axial direction, and the mountability is improved.

  Further, as described above, the reduction ratio of the secondary gear set 122 arranged on the downstream side of the driving force connection / disconnection mechanism 138 is set to be smaller than the reduction ratio of the idle gear set 120 arranged on the upstream side of the driving force connection / disconnection mechanism 138. By setting it large, the driving force up to the driving force connection / disconnection mechanism 138 can be reduced, and the inertial mass from the motor 70 can be reduced, so that the capacity of the driving force connection / disconnection mechanism 138 can be reduced. In addition, the mountability is improved, and the cost and weight can be reduced.

  Next, a structure for fixing the reduction gear case to the transmission case will be described with reference to FIGS. 5A shows a side view of the first reduction gear case 156 constituting the reduction gear case 78, and FIG. 5B shows a right side view of FIG. 5A. 6A shows a side view of the second reduction gear case 158 constituting the reduction gear case 78, and FIG. 6B shows a right side view of FIG. 6A.

  As shown in FIG. 5A, the first reduction gear case 156 includes an annular protrusion 160 that protrudes in the axial direction of the reduction mechanism, and a coupling portion mating surface 162 that connects the reduction gear case 78 to the transmission case 74. Is formed.

  Further, as shown in FIG. 5B, a boss portion 164 with a screw that is recessed inward is formed at the approximate center portion of the first reduction gear case 156. Further, a mounting flange 166 is formed on the outer periphery of the first reduction gear case 156.

  On the other hand, as shown in FIG. 6A, a boss portion 168 with a bolt through hole aligned with the boss portion 164 of the first reduction gear case 156 is formed at the approximate center of the second reduction gear case 158. . Further, a mounting flange 170 corresponding to the mounting flange 166 of the first reduction gear case 156 is formed on the outer periphery of the second reduction gear case 158.

  FIG. 7 shows the coupling portion mating surface 162 and the annular protrusion 160 on the reduction gear case 78 side. FIG. 8 shows an opening 172 on the transmission case 74 side and a coupling portion mating surface 174.

  FIG. 9 shows the first reduction gear case 156 viewed from the same direction as FIG. 5B, and the drive gear 106, the idler gear 114, and the driven gear constituting the idle gear set 120 are included in the first reduction gear case 156. 124 is housed.

  Reference numeral 162 'denotes a flange as seen from the back side of the coupling portion mating surface 162 shown in FIG. 7, and a plurality of coupling fastening bolt bosses 163 (four in this embodiment) are formed on the flange 162'.

  In order to attach the reduction gear case 78 to the transmission case 74, the coupling portion mating surface 162 of the reduction gear case 78 is aligned with the coupling portion mating surface 174 of the transmission case 74, and the annular protrusion 160 of the reduction gear case 78 is connected to the transmission. The reduction gear case 78 is fastened to the transmission case 74 with a bolt by fitting into the opening 172 formed in the case 74.

  As shown in FIG. 10, a seal structure with an O-ring 176 is formed on the outer peripheral portion of the annular projecting portion 160, i. By adopting the O-ring seal structure in this way, the number of coupling fastening bolts inserted into the coupling fastening bolt boss 163 of FIG. 9 can be minimized.

  As shown in FIG. 4, the speed reduction mechanism 72 includes a plurality of speed reduction gear sets, and a part of the speed reduction gear set, that is, the idle gear set 120 is supported by the reduction gear case 78, and the annular protrusion 160 is The bearings 110, 116, and 126 are arranged at substantially the same position in the axial direction. Thereby, the speed reduction mechanism 72 can be made compact in the axial direction.

  According to the motor speed reduction mechanism of the present embodiment, the speed reduction mechanism 72 is composed of a plurality of speed reduction gear sets, and a part of the gear sets, that is, the idle gear set 120 has a separate speed reducer structure. When it is desired to change the reduction ratio, the motor reduction ratio can be easily changed by changing the reduction ratio of the idle gear set 120. Therefore, since it is not necessary to manufacture a transmission case for every vehicle, costs can be reduced.

  In addition, since the annular protrusion 160 of the reduction gear case is fitted into the opening 172 of the transmission case, and the reduction gear case and the transmission case are bolted at the joint surface of both the coupling portions, the coupling fastening bolt It is possible to maintain a high sealing performance using an O-ring even in the vicinity of the gear meshing position where the gear cannot be disposed. Furthermore, the O-ring seal structure can reduce the number of fastening bolts for coupling as compared with packings, so that the speed reduction mechanism can be reduced in weight.

  Next, the detailed structure of the reducer case 78 will be described with reference to FIGS. 5, 6, 10, and 11. The reduction gear case 78 includes a first reduction gear case 156 and a second reduction gear case 158.

  As shown in FIG. 5 (B), the first reduction gear case 156 has a boss portion 164 with a screw hole that is recessed inwardly at a substantially central portion thereof. As shown in FIG. 6 (A), the second reduction gear case 158 has a boss portion 168 with a bolt through hole that protrudes inwardly in alignment with the boss portion 164 of the first reduction gear case 156 at its central portion. is doing.

  As best shown in the enlarged cross-sectional view of FIG. 11, the idler gear shaft 115 integrally formed with the idler gear 114 constituting the idle gear set 120 has a hollow structure, and the first reduction gear is provided in the idler gear shaft 115. The boss portion 164 of the machine case 156 and the boss portion 168 of the second reducer case 158 are inserted, and the first reducer case 156 and the second reducer case 158 are fastened with bolts 178 with the boss packing 184 interposed therebetween. . Reference numeral 182 denotes a packing positioning hollow pin.

  Further, as shown in FIG. 10, the mounting flange 166 of the first reduction gear case 156 and the mounting flange 170 of the second reduction gear case 158 are fastened with a plurality of bolts 180.

  According to the speed reducer case 78 of the present embodiment, the positioning pin 182 of the boss portion packing 184 is provided on the boss portion of the speed reducer case, so that when the speed reducer case is tightened during assembly of the speed reduction mechanism, Since the position of the packing 184 can be fixed, the speed reduction mechanism can be easily assembled.

  Also, the reduction mechanism is composed of multiple reduction gear sets, and some reduction gear shafts have a hollow structure, and a case tightening boss is provided in the shaft, thereby improving the rigidity of the reduction gear case and the case membrane. Gear noise due to surface vibration can be reduced.

  Referring to FIG. 12, a cross-sectional view of a speed reduction mechanism and a speed reducer case structure according to another embodiment of the present invention is shown. 13 is an enlarged cross-sectional view of the main part of FIG. In this embodiment, a reduction chain structure including a pair of sprockets 186 and 188 and a chain 190 is employed instead of the idle gear set 120. The secondary gear set 122 and the driving force connection / disconnection mechanism 138 are the same as those in the above-described embodiment.

  In this embodiment, the drive sprocket 186 is splined to the power transmission shaft 100 and the driven sprocket 188 is splined to the shaft 130. A chain 190 is wound around the drive sprocket 186 and the driven sprocket 188.

  The first reduction gear case 156 'has a case tightening boss 192 at its approximate center, and the second reduction device case 158' also has a case tightening boss 194 at its approximate center.

  A boss packing 198 is sandwiched between a case fastening boss 194 of the first reducer case 156 ′ and a case fastening boss 194 of the second reducer case 158 ′, and the second reducer case 158 ′ is secured with bolts 200 and 202. Is fastened to the first reducer case 156 ′. Reference numeral 196 denotes a packing positioning pin.

  According to this embodiment, by providing the positioning pin 196 of the boss portion packing 198 in the boss portion, the position of the boss portion packing can be fixed when the reduction gear case is tightened during assembly of the reduction mechanism. The speed reduction mechanism can be easily assembled.

  Further, by providing the case tightening bosses 192 and 194 between the drive sprocket 186 and the driven sprocket 188, the case rigidity can be improved and the chain noise due to the case film surface vibration can be reduced.

1 is a schematic overall configuration diagram of a power transmission device according to an embodiment of the present invention. It is a top view of an electric motor and a deceleration mechanism attaching part. It is a longitudinal cross-sectional view of the connection part of an electric motor and a reduction mechanism. It is a longitudinal cross-sectional view of the power transmission device concerning embodiment of this invention. It is a figure which shows a 1st reduction gear case. It is a figure which shows a 2nd reduction gear case. It is a figure which shows the annular processus | protrusion of a reduction gear case, and a coupling part matching surface. It is a figure which shows the opening part of a transmission case, and a coupling part mating surface. It is a figure which shows the flange of a 1st reduction gear case, and the fastening bolt boss for a coupling | bonding. It is a longitudinal cross-sectional view which shows the detailed structure of a reduction gear case. It is an expanded sectional view which shows the principal part of FIG. It is a longitudinal cross-sectional view which shows the reduction chain structure and reduction gear case of other embodiment of this invention. It is an expanded sectional view which shows the principal part of FIG.

Explanation of symbols

2 Engine 4 Torque converter 6 Automatic transmission 48 Final drive gear 66 Differential device 68 Ring gear (final driven gear)
70 Electric motor 72 Reduction mechanism 78 Reduction gear case 86 Rotor 88 Motor shaft 100 Power transmission shaft 120 Idle gear set 122 Secondary gear set 138 Driving force connecting / disconnecting mechanism 154 Final drive gear

Claims (2)

An electric motor;
A speed reduction mechanism comprising a plurality of gear sets for reducing the driving force of the electric motor;
A differential device that distributes the driving force decelerated by the deceleration mechanism to the left and right drive wheels;
In the vehicle power transmission device comprising the deceleration mechanism and a driving force connecting / disconnecting mechanism disposed in at least one of the differential devices,
A power transmission device for a vehicle, wherein a reduction ratio of a gear set downstream of the driving force connection / disconnection mechanism is set larger than a reduction ratio of a gear set upstream of the driving force connection / disconnection mechanism. A final drive gear for driving the ring gear of the differential device;
2. The vehicle power transmission device according to claim 1, wherein the driving force connecting / disconnecting mechanism is disposed at substantially the same position in the axial direction as the final drive gear.

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