CN110159707B

CN110159707B - Axle drive device

Info

Publication number: CN110159707B
Application number: CN201811579398.3A
Authority: CN
Inventors: 笠原崇宏
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2018-02-16
Filing date: 2018-12-24
Publication date: 2021-03-05
Anticipated expiration: 2038-12-24
Also published as: CN110159707A; JP2019143656A; JP6559818B1

Abstract

The invention provides an axle driving device, in a planetary gear speed reducing mechanism, when a high speed reduction ratio is obtained, a planetary gear needs to rotate at a high speed, and therefore a countermeasure against high-frequency vibration generated by the planetary gear needs to be taken. In view of the above-described conventional drawbacks, an object is to provide an axle drive device that can obtain a high reduction gear ratio and is less likely to generate high-frequency vibration. In an axle drive device, a plurality of step gears (31, 32) are connected in series and reduce the speed of a drive force transmission path of a planetary reduction mechanism (3) which transmits drive force to a 1 st axle (5) and a 2 nd axle (6) through a differential mechanism (4).

Description

Axle drive device

Technical Field

The present invention relates to an axle drive device.

Background

Among transaxles using an electric motor, those that reduce the speed of the electric motor by a speed reduction mechanism and transmit the reduced power to an output shaft are known.

In addition, a planetary gear reduction mechanism is used in order to obtain a high reduction ratio with a compact structure.

Further, as shown in patent document 1, a planetary gear reduction mechanism using a two-stage gear is known in order to obtain a higher reduction ratio.

Patent document 1: japanese patent laid-open No. 2009-36365.

Disclosure of Invention

However, in the planetary gear speed reduction mechanism, when a high speed reduction ratio is obtained, the planetary gear must be rotated at a high speed, and therefore, a countermeasure against the high-frequency vibration generated thereby is required.

In the structure disclosed in patent document 1, too, the planetary gear must be rotated at high speed in order to obtain a sufficient reduction ratio using a vehicle or the like.

In view of the above-described conventional disadvantages, an object of the present invention is to provide an axle drive device that achieves a high reduction gear ratio and is less likely to generate high-frequency vibration.

The present invention is characterized in that a drive force transmission path of a planetary reduction mechanism for transmitting drive force to the 1 st axle and the 2 nd axle via a differential gear includes a plurality of step gears connected in series for speed reduction.

Thus, the large-side gear of the stepped gear is meshed with the small-side gear of the other stepped gear, whereby the driving force is reduced. Further, since the step gear in which the large side gear and the small side gear are integrated is used, space is saved as compared with the case where a separate gear is used.

In the present invention, the driving force transmission path of the planetary reduction mechanism may be folded back in the extending direction of the support shaft of the stepped gear via the plurality of stepped gears.

Thus, the large-side gear of the stepped gear is meshed with the small-side gear of the other stepped gear, and the large-side gear of the other stepped gear is disposed on the small side of the previous stepped gear, whereby the reduction is performed a plurality of times within the width of the stepped gear.

In the present invention, the stepped gear on the downstream side of the power transmission path of the planetary reduction mechanism may be meshed with the ring gear of the planetary reduction mechanism via a planetary gear.

Thus, the planetary gear is arranged in accordance with the position of the downstream-side stepped gear, and the driving force of the downstream-side stepped gear is transmitted to the ring gear.

Further, a member for supporting one end of a support shaft of the planetary gear may be provided between the planetary gear and the large-side gear of the downstream-side stepped gear, and the support shaft of the planetary gear may be arranged at a position overlapping the large-side gear of the downstream-side stepped gear in the rotation axis direction of the 1 st axle.

This prevents the large-side gear of the downstream-side step gear from contacting the support shaft of the planetary gear.

Further, the sun gear of the planetary reduction mechanism and the large side gear of the downstream side step gear may be displaced in the rotation axis direction of the 1 st axle, and the large side gear of the downstream side step gear may be disposed at a position overlapping the sun gear in the rotation axis direction of the 1 st axle.

This allows the downstream step gear to be disposed close to the rotation shaft of the 1 st axle.

In the present invention, an oil passage may be provided in the support member of the planetary gear of the planetary reduction mechanism, the oil passage being provided on a side opposite to a side on which the planetary gear is arranged, and the oil passage provided in the support member and the oil passage in the support shaft of the planetary gear may be connected via a bearing portion of the support member that holds the support shaft of the planetary gear.

Thus, the oil passage is provided on the opposite side to the side where the planetary gears are arranged, regardless of the arrangement of the planetary gears.

Effects of the invention

According to the transaxle of the present invention, a transaxle having a large reduction ratio can be obtained. Further, since the reduction ratio is increased by the plurality of stepped gears, it is not necessary to rotate the planetary gear at a high speed, and high-frequency vibration caused by the high-speed rotation of the planetary gear can be reduced.

The rotation torque of the planetary reduction mechanism can be reduced, and the axle drive device can be configured compactly.

Further, the driving force transmission path is folded back in the extending direction of the support shaft of the step gear by means of the plurality of step gears, and according to this structure, the driving force transmission path can be reduced. This reduces the rotational torque of the planetary reduction mechanism, and enables the axle drive device to be constructed compactly.

Further, according to the configuration in which the stepped gear on the downstream side of the power transmission path is meshed with the ring gear of the planetary reduction mechanism via the planetary gear, the degree of freedom in the arrangement of the gears can be improved. This makes it possible to increase the downstream-side stepped gear and obtain a large reduction ratio.

Further, a member for supporting one end of a support shaft of the planetary gear is provided between the planetary gear and the large-side gear of the downstream-side stepped gear, and the support shaft of the planetary gear is arranged at a position overlapping the large-side gear of the downstream-side stepped gear in the rotation axis direction of the 1 st axle.

Further, according to this configuration, the sun gear of the planetary reduction mechanism and the large-side gear of the downstream-side step gear are displaced in the rotation axis direction of the 1 st axle, and the large-side gear of the downstream-side step gear is disposed at a position overlapping the sun gear in the rotation axis direction of the 1 st axle, and the downstream-side step gear can be disposed close to the rotation axis of the 1 st axle. This reduces the rotational torque of the planetary reduction mechanism.

Further, the oil passage provided in the support member and the oil passage in the support shaft of the planetary gear are connected to each other via a bearing portion of the support member that holds the support shaft of the planetary gear, whereby the lubricating oil can be supplied to the planetary gear with a simple configuration. This can improve the durability of the vehicle drive device.

Drawings

Fig. 1 is a front view showing an transaxle of embodiment 1 of the present invention.

Fig. 2 is a left side view of the transaxle.

Fig. 3 is a sectional view taken along line III-III in fig. 1.

Fig. 4 is a sectional view taken along line IV-IV in fig. 1.

Fig. 5 is a sectional view taken along line V-V in fig. 1.

Fig. 6 is a sectional view taken along line VI-VI in fig. 2.

Fig. 7 is a sectional view taken along line VII-VII in fig. 2.

Fig. 8 is a skeleton diagram schematically showing the structure of the transaxle in embodiment 1.

Fig. 9 is a perspective view showing the left side of the transaxle.

Fig. 10 is a perspective view showing the right side of the transaxle.

Fig. 11 is a perspective view showing the left side of the carrier according to embodiment 1 of the present invention.

Fig. 12 is a front view of the carrier.

Fig. 13 is a perspective view showing the right side of the carrier.

Fig. 14 is a perspective view showing a state in which a pinion gear is assembled to a carrier.

Fig. 15 is a partial sectional view showing a method of assembling the 2 nd step pinion on the carrier.

Fig. 16 is a partial sectional view showing a method of assembling the 1 st step pinion on the carrier.

Fig. 17 is a perspective view showing the lubrication oil passage of the carrier.

Fig. 18 is a sectional view showing a lubricating oil passage of the 1 st step pinion.

Fig. 19 is a left perspective view showing an transaxle according to embodiment 2 of the present invention.

Fig. 20 is a perspective view showing the right side of the transaxle of embodiment 2.

Fig. 21 is a front view of the transaxle of embodiment 2.

Fig. 22 is a sectional view taken along line XXII-XXII in fig. 21.

Fig. 23 is a sectional view taken along line XXIII-XXIII in fig. 21.

Fig. 24 is a skeleton diagram schematically showing the structure of the transaxle in embodiment 2.

Description of the reference symbols

1: an axle drive device;

2: a motor drive shaft;

3: a planetary mechanism;

4: a differential mechanism;

5: 1 st axle;

6: a 2 nd axle;

7: a planet carrier;

9: a side plate;

21: a sun gear;

31: a 1 st step pinion;

31 a: a gear;

31 b: a gear;

32: a 2 nd step pinion;

32 a: a gear;

32 b: a gear;

33: an outer pinion gear;

34: a ring gear;

41: 1 st pinion gear;

42: a 2 nd pinion gear;

43: a ring gear;

44: a differential case;

51: a gear.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

[ embodiment 1]

An transaxle 1 according to an embodiment of the present invention will be described with reference to fig. 1 to 10.

Fig. 1 is a front view showing an transaxle of embodiment 1 of the present invention, and fig. 2 is a left side view of the transaxle. Fig. 3 is a sectional view taken along the line III-III in fig. 1, and fig. 4 is a sectional view taken along the line IV-IV in fig. 1. Fig. 5 is a cross-sectional view taken along line V-V in fig. 1. Fig. 6 is a sectional view taken along line VI-VI in fig. 2, and fig. 7 is a sectional view taken along line VII-VII in fig. 2.

Fig. 8 is a skeleton diagram schematically showing the structure of the transaxle in embodiment 1. Fig. 9 is a perspective view showing the left side of the transaxle, and fig. 10 is a perspective view showing the right side of the transaxle.

Transaxle 1 includes differential mechanism 4 and planetary mechanism 3 as a planetary reduction mechanism, and has a 1 st axle 5 connected to the left side of transaxle 1 and a 2 nd axle 6 connected to the right side of transaxle 1. The transaxle 1 is connected to a motor drive shaft 2 as an input shaft of driving force, and the driving force is input to the transaxle 1.

The driving force input from the motor drive shaft 2 is decelerated by the planetary mechanism 3 and output to the 1 st axle 5 and the 2 nd axle 6 via the differential mechanism 4.

The motor drive shaft 2 is a hollow shaft extending in the left-right direction, and the 1 st axle 5 is inserted inside the motor drive shaft 2. The rotor of the electric motor can be attached to the outer peripheral surface of the motor drive shaft 2. Thereby, it is possible to directly drive the motor drive shaft 2 and output the driving force from the 1 st axle 5 passing through the inside of the motor drive shaft 2.

In addition, the driving force can be input to the motor drive shaft 2 by another configuration.

Next, the internal structure of transaxle 1 will be described in detail with reference to fig. 3 to 7.

The planetary mechanism 3 of the transaxle 1 is composed of a sun gear 21 provided at one end of the motor drive shaft 2, a 1 st step pinion 31, a 2 nd step pinion 32, an outer pinion 33, a ring gear 34, and a carrier 7.

The 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 are planetary gears.

The 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 are provided in 3 numbers, respectively, and are arranged at equal intervals around the motor drive shaft 2.

The carrier 7 is constituted by the differential case 44 and the side plate 9 integrally fixed to the base plate 70 via a stay. On the side plate 9, a cover plate 8 is mounted with 3 fastening points 81.

The stays are constituted by 1

st stay

71, 2

nd stay

72, 3

rd stay

73, 4

th stay

74, and 5 th stay 75, each of which is provided with 3.

The carrier 7 rotatably supports the 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33. The 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 have their rotation shafts arranged in parallel with the motor drive shaft 2.

The sun gear 21 is a gear having teeth provided toward the outside of the motor drive shaft 2, and rotates integrally with the motor drive shaft 2. The sun gear 21 meshes with the large gear 31a of the 1 st step pinion 31.

The 1 st step pinion 31 has a large gear 31a and a small gear 31b that rotate integrally. The large gear 31a is a large side gear, and the small gear 31b is a small side gear. The 1 st step pinion 31 is rotatably supported by a support shaft 31c, and the support shaft 31c is supported by the side plate 9 and the differential case 44.

The large gear 31a of the 1 st step pinion 31 rotates integrally with the small gear 31b, and the driving force is transmitted from the small gear 31b to the 2 nd step pinion 32.

The large gear 31a of the 1 st step pinion 31 is disposed on the left side of the side plate 9, and the small gear 31b is disposed on the right side of the differential case 44.

The 2 nd step pinion 32 is composed of a large gear 32a and a small gear 32b that rotate integrally, and the 2 nd step pinion 32 meshes with the 1 st step pinion 31 via the large gear 32 a. The large gear 32a is a large side gear, and the small gear 32b is a small side gear.

The 2 nd step pinion 32 is rotatably supported by a support shaft 32c, and the support shaft 32c is supported by the side plate 9 and the differential case 44. The large gear 32a of the 2 nd step pinion 32 is disposed on the differential case 44 side, and the small gear 32b is disposed on the side plate 9 side.

The pinion 32b of the 2 nd step pinion 32 is meshed with the outer pinion 33. The outer pinion 33 is disposed between the side plate 9 and the base plate 70.

The end portions of the support shafts 33c of the outer pinion gears 33 are supported by the side plates 9 and the base plate 70, respectively, and the outer pinion gears 33 are rotatably supported.

As shown in fig. 5 and 7, the support shaft 33c of the outer pinion gear 33 is disposed at a position overlapping the large gear 32a of the 2 nd step pinion gear 32 when viewed in the left-right direction of the transaxle 1.

Further, the base plate 70 is disposed between the side plate 9 and the differential case 44. The base plate 70 is disposed between the large gear 31a of the 1 st step pinion 31 and the large gear 32a of the 2 nd step pinion 32 in the left-right direction of the transaxle 1.

The support shaft 33c of the outer pinion gear 33 is disposed outside the support shaft 32c of the 2 nd step pinion gear 32, around the rotation shaft of the carrier 7.

In the vicinity of the outer pinion 33, a 1 st stay 71 and a 2 nd stay 72 extending from the base plate 70 are arranged. The outer pinion 33 is disposed between the 1 st stay 71 and the 2 nd stay 72 in the rotation direction of the side plate 9. The outer pinion 33 is disposed apart from the 1 st stay 71 and the 2 nd stay 72 by a gap corresponding to the gear gap amount of the outer pinion 33.

The outer pinion 33 meshes with the internal teeth of the ring gear 34 inside the ring gear 34.

The ring gear 34 is disposed on the side plate 9 side between the side plate 9 and the differential case 44. Further, a large gear 31a of the 1 st step pinion 31, a pinion 32b of the 2 nd step pinion 32, the sun gear 21, and the outer pinion 33 are disposed inside the ring gear 34. Ring gear 34 is fixed to transaxle 1 by a fixing means not shown. For example, ring gear 34 may be fixed to a housing that covers transaxle 1.

The large gear 32a of the 2 nd step pinion 32 is shifted from the ring gear 34 in the left-right direction of the transaxle 1. The tooth tips of the external teeth of the large gear 32a are configured to pass through the tooth roots of the internal teeth of the ring gear 34 on the outer side (the side apart from the revolution axis of the large gear 32 a).

The large gear 32a of the 2 nd step pinion 32 is offset from the sun gear 21 in the lateral direction of the transaxle 1, and the tip of the large gear 32a is configured to pass through the inner side of the root of the sun gear 21 (the side close to the revolution axis of the large gear 32 a).

Ring gear 34 is fixed to transaxle 1 so as not to rotate.

Here, the carrier 7 is configured to be rotatable about the motor drive shaft 2 as a rotation shaft. Thereby, the 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 supported by the carrier 7 can perform the revolving motion with respect to the motor drive shaft 2.

Therefore, the carrier 7 supporting the outer pinion gears 33 rotates by the driving force transmitted to the outer pinion gears 33.

The carrier 7 is connected to the differential mechanism 4 via a differential case 44, and the differential case 44 is a member common to the carrier 7 and the differential mechanism 4. Thereby, the driving force is transmitted from the carrier 7 to the differential mechanism 4.

The differential mechanism 4 is constituted by a differential case 44, a ring gear 43, a 1 st pinion gear 41, a 2 nd pinion gear 42, a support plate 61, and a 1 st axle 5. The rotational centers of the differential case 44, the ring gear 43, and the support plate 61 coincide with the rotational center of the 1 st axle 5.

A ring gear 43 is fixed to the differential case 44, and the 1 st pinion gear 41, the 2 nd pinion gear 42, and the gear 51 of the 1 st axle 5 are disposed inside the ring gear 43.

The ring gear 43 meshes with the 1 st pinion gear 41, and the 1 st pinion gear 41 is rotatably supported by the support shaft 41 c. The ends of the support shaft 41c are held on the support plate 61 and an extension 61a extending from the support plate 61, respectively.

The 1 st pinion gear 41 also meshes with the 2 nd pinion gear 42. The 2 nd pinion gear 42 is also rotatably supported by a support shaft, not shown, in the same manner as the 1 st pinion gear 41, and the support shaft is held by the support plate 61 and the extending portion 61 a. The 1 st pinion gear 41 and the 2 nd pinion gear 42 have their rotational shafts arranged in the left-right direction of the transaxle 1.

The 2 nd pinion gear 42 meshes with the gear 51 of the 1 st axle 5.

Further, the 2 nd axle 6 is connected to the support plate 61 on the side opposite to the 1 st axle 5.

The support plate 61 has the same rotational axis as the 2 nd axle 6.

Next, the structure of the carrier 7 will be described with reference to fig. 11 to 18.

Fig. 11 is a perspective view showing the left side of the carrier according to embodiment 1 of the present invention, and fig. 12 is a front view of the carrier. Fig. 13 is a perspective view showing the right side of the carrier, and fig. 14 is a perspective view showing a state in which a pinion is assembled to the carrier. Fig. 15 is a partial sectional view showing a method of assembling the 2 nd step pinion on the carrier, and fig. 16 is a partial sectional view showing a method of assembling the 1 st step pinion on the carrier. Fig. 17 is a perspective view showing a lubrication oil passage of the carrier, and fig. 18 is a sectional view showing a lubrication oil passage of the 1 st step pinion.

The carrier 7 is integrally fixed to a disc-shaped side plate 9 on a plane perpendicular to the rotational axis, the differential case 44, and a plate-shaped base plate 70 on a plane perpendicular to the rotational axis.

The base plate 70 includes an annular portion 70a, an extension portion 70b, and a distal end portion 70 e.

The annular portion 70a is provided annularly around the rotational axis of the

carrier

7, and 3 extending portions 70b extending outward from the annular portion 70a are connected to the annular portion 70 a.

The extending portions 70b are arranged at equal intervals in the circumferential direction around the rotational axis of the carrier 7. Further, in the extending portion 70b, a tip portion 70e extending along a circumference centered on the rotation axis is provided on the opposite side of the carrier 7 from the rotation axis side.

In the base plate 70, the annular portion 70a, the extending portion 70b, and the end portion 70e form a U-shaped cutout 70 c. In addition, the pinion 32b of the 2 nd step pinion 32 is disposed in the notch 70 c.

Further, the extending portion 70b is provided with an arcuate portion 70d recessed in an arcuate shape on the opposite side of the notch portion 70c, and the pinion 31b of the 1 st step pinion 31 is disposed.

Further, the annular portion 70a is provided with a 4 th stay 74 and a 5 th stay 75 on the rotation axis side of the carrier 7 so as to be perpendicular to the base plate 70.

Furthermore, the extension portion 70b is provided with a 3 rd stay 73 perpendicular to the base plate 70. Further, at the distal end portion 70e, the 1 st stay 71 and the 2 nd stay 72 are provided so as to be perpendicular to the base plate 70.

Further, 1 st, 2 nd, 3 rd, 4 th, and 5 th stays 71, 72, 73, 74, and 75 extend in the left-right direction of transaxle 1 from base plate 70.

The 1 st stay 71, the 2 nd stay 72, the 3 rd stay 73, the 4 th stay 74, and the 5 th stay 75 are provided in 3 numbers, respectively, and are arranged at equal intervals in the rotational direction of the carrier 7.

The 1 st stay 71, the 2 nd stay 72, the 3 rd stay 73, the 4 th stay 74, and the 5 th stay 75 extend from the edge of the base plate 70. Therefore, the plate portion extending from the base plate 70 may be bent by press forming or the like to form the 1 st stay 71, the 2 nd stay 72, the 3 rd stay 73, the 4 th stay 74, and the 5 th stay 75. The side plate 9 and the differential case 44 may be formed by forging and fixed to the base plate 70 by welding.

The 1 st stay 71, the 2 nd stay 72, and the 5 th stay 75 extend from the base plate 70 to the left of the transaxle 1, and the side plate 9 is fixed to the base plate 70. The 1 st stay 71 and the 2 nd stay 72 are connected to the outer peripheral edge of the side plate 9.

The 1 st and 2 nd stays 71 and 72 are disposed outside the support shaft 33c of the outer pinion 33 (on the side away from the rotation shaft of the side plate 9). Further, the 1 st stay 71 and the 2 nd stay 72 are shaped along the outer peripheral edge of the side plate 9, and are arcuate when viewed in the left-right direction of the transaxle 1.

The 5 th stay 75 is connected to an edge of an opening 92 of the side plate 9, and the motor drive shaft 2 is inserted into the opening 92. The 5 th stay 75 is disposed so as to surround the outer peripheral surface of the sun gear 21 of the motor drive shaft 2.

The sun gear 21 meshes with the large gear 31a of the 1 st step pinion 31 between the 5 th stays 75.

Third and fourth stays 73 and 74 extend from base plate 70 to the right of transaxle 1, and fix differential case 44 to base plate 70.

The differential case 44 is provided with a circular opening 44b into which the 1 st axle 5 is inserted, and a 4 th stay 74 is connected around the opening 44 b. The 4 th stay 74 has an arc-shaped cross section along the edge of the opening 44 b.

Further, the outer peripheral portion of the large gear 32a of the 2 nd step pinion 32 is positioned between the 4 th stays 74.

The 3 rd support bars 73 are provided on the base plate 70 in a direction outward from the rotational axis of the carrier 7. Further, the 3 rd support 73 is formed in an arc shape in which the base plate 70 is convex on the surface perpendicular to the rotational axis of the carrier 7.

The 3 rd stay 73 is disposed between the 1 st step pinion 31 and the 2 nd step pinion 32.

As shown in fig. 15, when the 1 st and 2 nd step pinions 31 and 32 are assembled to the carrier 7, the 2 nd step pinion 32 is inserted between the side plate 9 and the differential case 44. As shown in fig. 16, the pinion gear 32b of the 2 nd step pinion gear 32 is positioned in the notch portion 70c of the base plate 70.

The side plate 9 is provided with a bearing portion 94 into which the support shaft 32c of the 2 nd step pinion 32 is inserted, and the support shaft 32c is inserted from the bearing portion 94, so that the 2 nd step pinion 32 is rotatably fixed to the carrier 7. Further, a bearing that holds the support shaft 32c is formed in the differential case 44 at a position corresponding to the bearing portion 94 in the left-right direction of the transaxle 1. Thereby, the support shaft 32c is held between the side plate 9 and the differential case 44.

After the 2 nd step pinion 32 is assembled to the carrier 7, the 1 st step pinion 31 is inserted between the side plate 9 and the differential case 44. And, the pinion 31b of the 1 st step pinion 31 is made to be located at the circular arc portion 70d of the base plate 70.

As shown in fig. 13, the side plate 9 is provided with a bearing portion 93 into which the support shaft 31c of the 1 st step pinion 31 is inserted. The support shaft 31c is inserted from the bearing portion 93, and the 1 st step pinion 31 is rotatably fixed to the carrier 7. Further, a bearing that holds the support shaft 31c is formed in the differential case 44 at a position corresponding to the bearing portion 93 in the left-right direction of the transaxle 1. Thereby, the support shaft 31c is held between the side plate 9 and the differential case 44.

The outer pinion 33 is inserted between the side plate 9 and the base plate 70. The side plate 9 is provided with a bearing portion 95 into which the support shaft 33c of the outer pinion gear 33 is inserted, the support shaft 33c is inserted from the bearing portion 95, and the outer pinion gear 33 is rotatably fixed to the carrier 7. Further, support holes 76 for holding the support shafts 31c are provided in the base plate 70 at positions corresponding to the bearing portions 93 in the left-right direction of the transaxle 1. Thereby, the support shaft 33c is held between the side plate 9 and the base plate 70.

In the above-described structure of the carrier 7, the base plate 70 is disposed between the side plate 9 and the differential case 44. Thereby, one end of the support shaft 33c of the outer pinion 33 is held by the base plate 70. Therefore, the outer pinion 33 can be arranged regardless of the arrangement structure on the differential case 44 side, and the degree of freedom in the arrangement of the support shaft 33c of the outer pinion 33 can be increased.

In addition, the support shaft 33c can be disposed at a position overlapping the large gear 32b of the 2 nd step pinion 32 in the left-right direction of the transaxle 1.

This makes it possible to enlarge the large gear 32b of the 2 nd step pinion 32, and to realize the planetary mechanism 3 having a large reduction ratio.

Further, the 1 st stay 71 and the 2 nd stay 72 are disposed near the outer pinion 33, and the outer pinion 33 can be disposed between the 1 st stay 71 and the 2 nd stay 72 which are close to each other. This can increase the support rigidity of the outer pinion 33, and can improve the durability of the planetary mechanism 3.

Further, a 1 st stay 71 is provided between the outer pinion 33 and the 1 st step pinion 31. Further, a 2 nd stay 72 is provided between the outer pinion 33 and the 2 nd step pinion 32. This improves the support rigidity among the outer pinion 33, the 1 st step pinion 31, and the 2 nd step pinion 32.

This improves the assembly accuracy of transaxle 1, improves durability, and reduces noise.

Next, a structure of lubrication of the planetary mechanism 3 will be explained.

As shown in fig. 11 and 17, an oil passage 91 is provided in the side plate 9 on the side opposite to the side on which the differential case 44 is disposed.

The oil passage 91 is formed by a concave portion on the surface of the side plate 9, and is formed by an annular oil passage 91a provided around the opening 92,

linear oil passages

91b, 91c, and 91d radially extending from the annular oil passage 91 a.

The tip end of the oil passage 91b is connected to a bearing portion 95 of the outer pinion gear 33, so that lubricating oil can be supplied to the outer pinion gear 33. The oil passage 91c is connected to the bearing portion 93 of the 1 st step pinion 31, and can supply the lubricating oil to the 1 st step pinion 31. The oil passage 91d is connected to the bearing portion 94 of the 2 nd step pinion 32, and can supply the lubricating oil to the 2 nd step pinion 32.

A configuration for supplying the lubricating oil to the 1 st step pinion 31 will be described with reference to fig. 18.

A cover plate 8 is attached to the side plate 9, and a 1 st step pinion 31 is disposed on the side plate 9 on the opposite side of the cover plate 8.

The side plate 9 is provided with a rising portion 96 extending in the rotation axis direction along the motor drive shaft 2 on the rotation axis side of the side plate 9. An annular oil passage 91a is provided outside the rising portion 96, and the annular oil passage 91a and an oil passage 91c connected to the annular oil passage 91a are covered with the cover plate 8.

The cover plate 8 has a shift portion 82 shifted from the 1 st step pinion 31 on the rising portion 96 side. The offset portion 82 is connected to a mounting portion 83 mounted on the side plate 9 via a connecting portion 84 inclined from the offset portion 82 toward the 1 st step pinion 31.

In a state where the attachment portion 83 of the cover 8 is attached to the side plate 9, the offset portion 82 is held at a position not in contact with the side plate 9. Thus, an opening 85 is provided between the offset portion 82 and the side plate 9.

The opening 85 is annularly provided around the rising portion 96 of the side plate 9 and communicates with the annular oil passage 91 a.

Further, a lubricating oil passage 31d is provided inside the support shaft 31c of the 1 st step pinion 31, and the lubricating oil passage 31d is connected to an oil passage not shown, so that lubricating oil can be supplied between the 1 st step pinion 31 and the support shaft 31 c.

Next, the operation of the planetary mechanism 3 and the differential mechanism 4 in embodiment 1 of the present invention will be described.

When the driving force is transmitted from the motor drive shaft 2, the 1 st step pinion 31 is driven by the sun gear 21 fixed to the motor drive shaft 2. The sun gear 21 meshes with a large gear 31a of a 1 st step pinion 31, and the 1 st step pinion 31 transmits the driving force to a 2 nd step pinion 32 via a pinion 31 b. The driving force input to the large gear 31a is transmitted from the small gear 31b, and thus the driving force completes deceleration in the 1 st step pinion 31.

Similarly, the 2 nd step pinion 32 also decelerates the driving force and transmits the driving force to the outer pinion 33. The outer pinion gear 33 performs the revolving motion by the ring gear 34 having more teeth than the outer pinion gear 33, and thus the driving force is further decelerated.

The driving force is transmitted from the outer pinion gear 33 to the carrier 7 supporting the outer pinion gear 33, and is input to the differential mechanism 4.

The differential case 44 rotates by the rotation of the carrier 7, and the ring gear 43 provided integrally with the differential case 44 rotates. The ring gear 43 meshes with the 1 st pinion gear 41, and the 1 st pinion gear 41 meshes with the 2 nd pinion gear 42.

The 2 nd pinion gear 42 meshes with a gear 51 fixed to the 1 st axle 5.

The support plate 61 is fixed to one end of the 2 nd axle 6 and rotates integrally with the 2 nd axle 6.

Thus, the driving force input to the differential case 44 is transmitted to the 1 st axle 5 and the 2 nd axle 6 via the differential mechanism 4.

In the above-described driving force transmission path, the 1 st step pinion 31 and the 2 nd step pinion 32 are connected in series to perform deceleration. In the planetary mechanism 3, a pinion gear 32b of a 2 nd step pinion gear 32 is disposed on the side of the large gear 31a of the 1 st step pinion gear 31, and a large gear 32a is disposed on the side of the small gear 31 b.

Thus, the driving force is transmitted to the pinion 31b side positioned on the right side of transaxle 1 by 1 st step pinion 31, and the driving force is transmitted to the pinion 32b side positioned on the left side of transaxle 1 by 2 nd step pinion 32.

Therefore, in the planetary mechanism 3, the driving force can be folded back in the extending direction of the

support shafts

31c and 32c by the 1 st and 2 nd step pinions 31 and 32, which are a plurality of step gears. Further, the deceleration path for decelerating the driving force can be folded back in the left-right direction of transaxle 1, and a large reduction ratio can be obtained while using a small amount of space.

In addition, in the planetary mechanism 3, the 1 st and 2 nd step pinions 31, 32 can be efficiently arranged in a limited space.

Further, the pinion gear 32b of the 2 nd step pinion gear 32 on the downstream side of the driving force path is connected to the ring gear 34 via the outer pinion gear 33. The degree of freedom in the arrangement of the 2 nd step pinion 32 is increased by the outer pinion 33, and the 2 nd step pinion 32 can be increased in diameter to increase the reduction ratio.

Further, since the large gear 32a of the 2 nd step pinion 32 is shifted from the sun gear 21 of the motor drive shaft 2, the 2 nd step pinion 32 can be disposed inside the rotation shaft of the planetary mechanism 3. Further, the large gear 32a can be enlarged, and the planetary mechanism 3 with a large reduction ratio can be realized.

Further, since the support shaft 33c of the outer pinion gear 33 is disposed outside the support shaft 32c of the 2 nd step pinion gear 32, the 2 nd step pinion gear 32 can be disposed on the rotation shaft side of the planetary mechanism 3. This reduces the torque generated when the planetary mechanism 3 rotates. Further, the vibration when the carrier 7 rotates can be reduced.

Next, the operation of the lubrication structure of the planetary mechanism 3 will be described.

By the rotation of the carrier 7, the lubricating oil stored in the transaxle 1 is splashed. The lubricating oil splashed and reaching the opening 85 flows into the annular oil passage 91 a. Then, the centrifugal force generated by the rotation of the carrier 7 flows into the

oil passages

91b, 91c, and 91 d.

The lubricating oil that has flowed in through opening 85 is not allowed to flow out to the outside of

oil passages

91b, 91c, and 91d by cover plate 8, but is supplied to bearing 95, bearing 93, and bearing 94, respectively.

The lubricating oil flowing into the oil passage 91c flows into the lubricating oil passage 31d provided in the support shaft 31c of the 1 st step pinion 31 via the bearing portion 93 connected to the oil passage 91 c. Further, the lubricating oil is supplied between the 1 st step pinion 31 and the support shaft 31c by an oil passage not shown.

Similarly, in the oil passage 91d connected to the bearing portion 94, lubricating oil is supplied between the 2 nd step pinion 32 and the support shaft 32 c.

Similarly, the outer pinion gear 33 is also supplied with lubricating oil between the outer pinion gear 33 and the support shaft 33c via the oil passage 91b connected to the bearing portion 95.

This makes it possible to construct the lubrication mechanism of the planetary mechanism 3 with a simple configuration. The 1 st and 2 nd step pinions 31, 32 and the outer pinion 33 of the planetary mechanism 3 can be lubricated reliably.

Further, the lubricating oil is supplied to the support shaft 33c of the outer pinion gear 33 through an oil passage 91b provided linearly from the support member of the support shaft 33c, that is, the vicinity of the rotation shaft of the side plate 9. Therefore, the supply path of the lubricating oil can be shortened, and the lubricating oil can be reliably supplied.

Further, by detaching the cover plate 8, maintenance of the annular oil passage 91a, the oil passage 91b, the oil passage 91c, and the oil passage 91d can be easily performed.

[ embodiment 2]

Next, transaxle 11 according to embodiment 2 of the present invention will be described with reference to fig. 19 to 24.

Fig. 19 is a perspective view showing the left side of the transaxle of embodiment 2 of the present invention, and fig. 20 is a perspective view showing the right side of the transaxle of embodiment 2. Fig. 21 is a front view of the transaxle of embodiment 2, and fig. 22 is a cross-sectional view taken along line XXII-XXII in fig. 21. Fig. 23 is a cross-sectional view taken along line XXIII-XXIII in fig. 21, and fig. 24 is a skeleton diagram schematically illustrating the structure of the transaxle in embodiment 2.

Transaxle 11 of embodiment 2 is different from transaxle 1 of embodiment 1 in the point that planetary mechanism 35 and differential mechanism 45 are provided, and the other configurations are the same.

Therefore, planetary mechanism 35 and differential mechanism 45 of transaxle 11 will be explained.

As shown in fig. 19, the planetary mechanism 35 of the transaxle 11 is composed of the sun gear 21, the 1 st step pinion 31, the 2 nd step pinion 32, the outer pinion 33, the ring gear 34, and the carrier 17 provided at one end of the motor drive shaft 2.

The carrier 17 is formed of a side plate 19 and a differential case 44.

The carrier 17 rotatably supports the 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33. The 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 have their rotation shafts arranged in parallel with the motor drive shaft 2.

The 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 are rotatably supported between the side plate 19 and the differential case 44.

The large gear 31a side of the 1 st step pinion 31 is supported by the side plate 19, and the pinion 31b side of the 1 st step pinion 31 is supported by the differential case 44 via the shaft 17 c.

The large gear 32a side of the 2 nd step pinion 32 is supported by the side plate 19 via the shaft 17d, and the pinion 32b side of the 2 nd step pinion 32 is supported by the differential case 44.

One end side of the outer pinion 33 is connected to the side plate 19 via a shaft 17b, and the other end side of the outer pinion 33 is connected to the differential case 44.

The sun gear 21 is a gear whose teeth are provided toward the outside of the motor drive shaft 2, and the sun gear 21 rotates integrally with the motor drive shaft 2. The sun gear 21 meshes with the large gear 31a of the 1 st step pinion 31.

The 2 nd step pinion 32 is composed of a large gear 32a and a small gear 32b that rotate integrally, and the 2 nd step pinion 32 meshes with the small gear 31b of the 1 st step pinion 31 via the large gear 32 a.

The pinion 32b of the 2 nd step pinion 32 is meshed with the outer pinion 33.

The outer pinion 33 meshes with the ring gear 34.

The ring gear 34 is disposed on the differential case 44 side between the side plate 19 and the differential case 44. Further, the pinion 32b of the 2 nd step pinion 32 and the outer pinion 33 are disposed inside the ring gear 34. The ring gear 34 is fixed to the transaxle 11 by a fixing means not shown.

Ring gear 34 is fixed against rotation in transaxle 11.

The side plate 19 and the differential case 44 are integrally fixed by the shaft 17b, the shaft 17c, and the shaft 17 d. The side plate 19 and the differential case 44 can be rotated about the motor drive shaft 2 as a rotation shaft.

Thereby, the 1 st step pinion 31, the 2 nd step pinion 32, and the outer pinion 33 can perform revolution movement with respect to the motor drive shaft 2.

Therefore, the differential case 44 is rotated by the driving force transmitted to the outer pinion 33.

The differential mechanism 45 is constituted by a differential case 44, a ring gear 43, a 1 st pinion gear 41, a 2 nd pinion gear 42, a support plate 52, and a gear 6a of the 2 nd axle 6.

The rotational centers of the differential case 44, the ring gear 43, and the support plate 52 coincide with the rotational center of the 2 nd axle 6.

A ring gear 43 is fixed to the differential case 44, and a 1 st pinion gear 41, a 2 nd pinion gear 42, and a gear 6a of the 2 nd axle 6 are disposed inside the ring gear 43.

The ring gear 43 meshes with the 1 st pinion gear 41, and the 1 st pinion gear 41 meshes with the 2 nd pinion gear 42.

The 1 st pinion gear 41 and the 2 nd pinion gear 42 are rotatably supported by the support plate 52, and the 1 st axle 5 is connected to the support plate 52.

The 2 nd pinion gear 42 meshes with the gear 6a of the 2 nd axle 6.

The operation of transaxle 11 according to embodiment 2 of the present invention will be described.

When the driving force is transmitted from the motor drive shaft 2, the 1 st step pinion 31 is driven by the sun gear 21 fixed to the motor drive shaft 2. The sun gear 21 meshes with a large gear 31a of a 1 st step pinion 31, and the 1 st step pinion 31 transmits the driving force to a 2 nd step pinion 32 via a pinion 31 b. Since the driving force input to the large gear 31a is transmitted from the small gear 31b, the driving force is decelerated.

Also, the 2 nd step pinion 32 also decelerates the driving force and transmits it to the outer pinion 33. The outer pinion 33 performs the revolving motion by means of the ring gear 34 having more teeth than the outer pinion 33, and thus the driving force is further decelerated.

The driving force is transmitted from the outer pinion gear 33 to the differential case 44 that supports the outer pinion gear 33, and is input to the differential mechanism 4.

The differential case 44 rotates, so that the ring gear 43 provided integrally with the differential case 44 rotates. The ring gear 43 meshes with the 1 st pinion gear 41, and the 1 st pinion gear 41 meshes with the 2 nd pinion gear 42.

The 2 nd pinion gear 42 meshes with a gear 6a fixed to the 2 nd axle 6.

Further, the support plate 52 is fixed to one end of the 1 st axle 5, and the support plate 52 rotates integrally with the 1 st axle 5.

Thereby, the driving force input to the differential case 44 is transmitted to the 1 st axle 5 and the 2 nd axle 6 via the differential mechanism 4.

In this way, since the 1 st and 2 nd step pinions 31, 32 are arranged in the planetary mechanism 35, the planetary mechanism 35 can be made compact and a large reduction ratio can be obtained. Further, since the 1 st and 2 nd step pinions 31 and 32 can be disposed close to the 1 st and 2

nd axles

5 and 6, the rotational torque of the planetary mechanism 35 can be reduced.

The above-described embodiment is merely one embodiment of the present invention, and can be modified and applied arbitrarily without departing from the scope of the present invention.

Claims

1. An axle drive device characterized in that,

a drive force transmission path of a planetary reduction mechanism for transmitting drive force to a 1 st axle and a 2 nd axle via a differential mechanism includes a plurality of step gears connected in series for speed reduction,

a step gear on the downstream side of the power transmission path of the planetary reduction mechanism meshes with a ring gear of the planetary reduction mechanism via a planetary gear,

a member that supports one end of a support shaft of the planetary gear is provided between the planetary gear and the large-side gear of the downstream-side stepped gear, and the support shaft of the planetary gear is arranged at a position overlapping the large-side gear of the downstream-side stepped gear in the rotation axis direction of the 1 st axle.

2. The transaxle of claim 1 wherein,

the driving force transmission path of the planetary reduction mechanism is folded back in the extending direction of the support shaft of the step gear via the plurality of step gears.

3. The transaxle of claim 1 or 2 wherein,

the sun gear of the planetary reduction mechanism and the large-side gear of the downstream-side step gear are shifted in the rotational axis direction of the 1 st axle,

the small-side gear of the downstream-side step gear is disposed at a position overlapping the sun gear in the rotational axis direction of the 1 st axle.

4. The transaxle of claim 1 or 2 wherein,

an oil passage is provided in a support member of the planetary gear of the planetary reduction mechanism,

the oil passage is provided on the opposite side of the side where the planetary gear is disposed,

the oil passage provided in the support member and the oil passage in the support shaft of the planetary gear are connected to each other via a bearing portion of the support member that holds the support shaft of the planetary gear.

5. An axle drive device characterized in that,

6. An axle drive device characterized in that,

the oil passage provided in the support member is connected to an oil passage in the support shaft of the planetary gear via a bearing portion of the support member that holds the support shaft of the planetary gear.