JP2009274560A - Drive shaft device for double rear-axle drive vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive shaft device for a double rear-axle drive vehicle in which a crossing angle with respect to an intermediate axle between a rear front axle and a rear rear-axle can be minimized without setting the height of a pinion of the rear rear-axle higher than the rear rear-axle, and lubrication performance related to a pinion gear of the rear rear-axle can be secured. <P>SOLUTION: The device is provided with an input shaft 32 supported by a rear rear-axle housing 30 to extend in the forward-backward direction of the vehicle above the rear rear-axle 8, a drive gear 34 installed at the input shaft rearward of the rear rear-axle, the pinion gear 38 disposed rearward of the rear rear-axle and below the input shaft to be engaged with a ring gear of the differential of the rear rear-axle, and a driven gear 42 installed at a shaft rearward of the pinion gear to be engaged with the drive gear. The drive gear and the driven gear are composed of a bevel gear, and the axis of the pinion gear is inclined to be raised frontward toward the front of the vehicle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive shaft device for a rear two-shaft drive vehicle having two drive axles.

In the drive shaft device of the rear two-axis drive vehicle having two drive axles, the propulsion force of the prime mover provided at the front portion of the vehicle is transmitted to the rear front shaft through the propulsion shaft, and the propulsion force is further transmitted. It is necessary to transmit to the rear rear shaft through the intermediate shaft.
For this reason, in the rear front shaft housing that supports the rear front shaft of the rear two-shaft drive vehicle, the propulsive force input to the input shaft together with the input shaft to which the propulsive force is input via the propulsion shaft from the prime mover, There is known a drive shaft device in which an output shaft for transmitting a propulsive force to a rear rear shaft via an intermediate shaft is provided (see Patent Documents 1 and 2).

Also known is a drive shaft device in which an input shaft is disposed above the rear rear shaft and a differential pinion gear of the rear rear shaft is disposed behind the rear rear shaft in the rear rear shaft of the rear two-shaft drive vehicle. (Patent Document 3)
JP-A-8-58411 JP-A-8-58413 Japanese Utility Model Publication No. 4-70521

  In the drive shaft device as shown in Patent Documents 1 and 2, the output shaft extending to the rear of the rear front shaft needs to avoid interference with components inside the rear front shaft housing. On the other hand, the connecting portion between the propulsion shaft and the input shaft of the rear front shaft is preferably higher than the rear front shaft. This is mainly because it is preferable that the angle of intersection between the propulsion shaft and the input shaft of the rear front shaft is smaller, and that it is preferable that the ground clearance is larger in consideration of running performance. Since the input shaft and the output shaft are provided on the same axis, as a result, the output shaft is also disposed above the rear front shaft.

  On the other hand, a pinion gear that meshes with the differential ring gear of the rear rear shaft is generally disposed in front of the rear rear shaft. When a hypoid gear is used for the differential ring gear and pinion gear of the rear rear shaft, a so-called hypoid offset is required. Regarding the hypoid offset, the pinion gear is arranged at a position lower than the rear rear shaft in consideration of the tooth contact and engagement ratio of the ring gear and the pinion gear in the vehicle forward direction. As a result, since the pinion gear is in a low position, the lubricity of the bearing portion is also advantageous, but the intersection angle between the output shaft and the intermediate shaft and the intersection angle between the intermediate shaft and the rear rear shaft tend to be large. There is.

  Conversely, if the height of the pinion gear of the rear rear shaft is matched with the height of the output shaft of the rear front shaft housing, the intersection angle of the output shaft and the intermediate shaft and the intermediate shaft and the rear rear shaft The angle of intersection with the pinion gears is reduced, and the load on the joints connecting them, and the load on the bearings of the output shaft and the pinion gear of the rear rear shaft are also reduced. However, there is a problem that proper tooth contact and engagement ratio of the pinion gear and the ring gear cannot be obtained, and lubrication related to the bearing portion of the pinion gear is disadvantageous.

  Further, in the drive shaft device as shown in Patent Document 3, since the pinion gear of the rear rear shaft is parallel to the input shaft, a pinion gear of the rear rear shaft and a differential ring gear that meshes with the pinion gear are particularly provided. When configured with a hypoid gear that requires a so-called hypoid offset, it is still impossible to obtain the desired appropriate tooth contact and engagement ratio between the pinion gear and the differential ring gear while ensuring the lubricity of the pinion gear. The problem arises.

  The present invention has been devised in view of such problems, and the intermediate shaft between the rear front shaft and the rear rear shaft without increasing the height of the pinion gear of the rear rear shaft from that of the rear rear shaft. It is an object of the present invention to provide a drive shaft device for a rear two-shaft drive vehicle that can reduce the angle of intersection as much as possible and ensure the lubricity of the pinion gear of the rear rear shaft.

  In order to achieve the above-described object, a drive shaft device for a rear two-shaft drive vehicle according to claim 1 extends to a rear front shaft housing that supports the rear front shaft, toward the rear of the vehicle above the rear front shaft. In the drive shaft device of the rear two-shaft drive vehicle in which the output shaft for transmitting the driving force to the rear rear shaft is supported, the rear rear shaft housing for supporting the rear rear shaft, and the rear rear shaft housing are supported. An input shaft that extends toward the front of the vehicle above the rear rear shaft and receives driving force from the output shaft; and a drive gear that is mounted on the input shaft of the rear rear shaft behind the rear rear shaft; And a pinion gear that is supported by the rear rear shaft housing and is disposed behind the rear rear shaft and below the input shaft, and meshes with a differential ring gear of the rear rear shaft. And behind the pinion gear A driven gear which is mounted on the shaft portion and meshes with the drive gear, and the drive gear and the driven gear are constituted by bevel gears, so that the axis of the pinion gear rises forward toward the front of the vehicle. It is characterized by being inclined.

According to a second aspect of the present invention, there is provided a drive shaft device for a rear two-shaft drive vehicle according to the first aspect, wherein the differential ring gear and the pinion gear of the rear rear shaft are constituted by hypoid gears, and the axis of the pinion gear is It is characterized in that it is located above the axis.
According to a third aspect of the present invention, there is provided a drive shaft device for a rear two-shaft drive vehicle according to the second aspect, wherein the rear front shaft differential disposed in the rear front shaft housing and the differential front A pinion gear that meshes with the ring gear and rotates in a direction opposite to the output shaft, and the positional relationship between the pinion gear of the rear rear shaft and the ring gear in the vehicle width direction is the pinion gear of the rear front shaft and the ring gear. It is characterized by being reverse to the positional relationship in the vehicle width direction.

  According to the drive shaft device of the rear two-shaft drive vehicle of claim 1 of the present invention, the input shaft of the rear rear shaft is disposed above the rear rear shaft, so that the output shaft of the rear front shaft And the crossing angle of the intermediate shaft and the crossing angle of the intermediate shaft and the input shaft of the rear rear shaft can be set small. Further, since there is no pinion gear meshing with the ring gear and a bearing portion for supporting the shaft portion in front of the ring gear of the rear rear shaft, a connecting portion between the input shaft and the intermediate shaft on the rear rear shaft is provided. Since the distance between the rear rear shaft and the rear rear shaft can be as close as possible to the rear rear shaft, the intermediate shaft can be set to a longer length, and the above-mentioned intersection angle can be set smaller. it can. Further, the drive gear and the driven gear are constituted by bevel gears, whereby the axis of the pinion gear is inclined so as to rise upward toward the front of the vehicle, so that the bearing portion of the pinion gear is positioned at a lower position. Therefore, the lubricity of the pinion gear can be ensured.

  According to the invention of claim 2, the pinion gear and the ring gear are constituted by a hypoid gear, the axis of the pinion gear is positioned above the axis of the rear rear shaft, so-called hypoid offset is set, Appropriate tooth contact and meshing ratio of the pinion gear and ring gear can be obtained. Moreover, even if the hypoid offset is set in this way, the pinion gear is inclined so as to rise forward, so that the bearing portion of the pinion gear is disposed sufficiently below the axis of the rear rear shaft. Thus, the lubricity of the pinion gear can be ensured.

  According to the invention of claim 3, the rotation direction of the pinion gear that drives the rear front shaft is the same as the rotation direction of the pinion gear that drives the rear rear shaft. Can be rotated in the same direction. Here, in the hypoid type pinion gear and ring gear that require offset, it is necessary for the ring gear to have a tooth contact on the convex side of the ring gear when the vehicle moves forward. It is determined. Under the determined conditions, if the axis of the pinion gear that drives the rear rear shaft is offset below the axis of the ring gear, the meshing rate of the pinion gear with the ring gear is small. This results in the disadvantage that the number of teeth meshing simultaneously decreases. However, according to the third aspect of the present invention, since the axis of the pinion gear is offset above the axis of the ring gear, a desired tooth contact and a desired tooth can be obtained in meshing between the pinion gear and the ring gear. The lubricity of the support part of the pinion gear can be secured while securing the meshing rate.

An embodiment of the present invention will be described with reference to FIGS. 1 is a side view showing the whole of the embodiment, FIG. 2 is an enlarged view of a main part of FIG. 1, FIG. 3 is an arrow view along arrow III in FIG. 2, and FIG. It is arrow sectional drawing.
As shown in FIG. 1, a prime mover 4 is disposed at the front of the vehicle 2, and a rear front shaft 6 and a rear rear shaft 8 are disposed at the rear of the vehicle. The propulsive force of the prime mover 4 is transmitted to the rear front shaft 6 via the propulsion shaft 10. Further, the driving force of the prime mover 4 is transmitted to the rear rear shaft 8 via the intermediate shaft 12.

  As shown in FIGS. 2 and 3, the rear front shaft housing 14 that supports the rear front shaft 6 has an input shaft 16 coupled to the propulsion shaft 10 and a coaxial with the input shaft 16 via a sleeve 18. The output shaft 20 connected to is supported. The input shaft 16 and the output shaft 20 are disposed above the rear front shaft 6. The output shaft 20 extends toward the rear of the vehicle so as to be connected to the intermediate shaft 12. The rear front shaft housing 14 is provided with a differential ring gear 24 (not shown) of the rear front shaft 6 and a pinion gear 26 that meshes with the ring gear 24 is supported. The ring gear 24 and the pinion gear 26 are constituted by hypoid type gears, and the axis of the pinion gear 26 is arranged with a so-called hypoid offset H with respect to the axis of the ring gear 24. A driven gear 28 that meshes with the drive gear 22 is attached to the shaft portion 26 a of the pinion gear 26.

  As a result, the driving force input to the input shaft 16 is transmitted to the differential of the rear front shaft 6 via the drive gear 22, the driven gear 28, the pinion gear 26 and the ring gear 24. This configuration is substantially the same as the configuration disclosed in Patent Document 2 described above. Instead, an interaxle diff that allows a differential between the input shaft 16 and the output shaft 20 may be provided. In that case, for example, the configuration disclosed in Patent Document 1 described above can be employed.

  The rear rear shaft housing 30 that supports the rear rear shaft 8 supports an input shaft 32 that is coupled to the intermediate shaft 12 and extends to the rear of the rear rear shaft. A drive gear 34 is attached to the rear end of the input shaft 32. The rear rear shaft housing 30 includes a differential ring gear 36 (not shown) of the rear rear shaft 8 and a pinion gear 38 that meshes with the ring gear 36. As clearly shown in FIG. 4, the pinion gear 38 is rotatably supported by a rear rear shaft housing 30 via a bearing 40 with a shaft portion 38 a extending toward the rear of the vehicle.

  The ring gear 36 and the pinion gear 38 are constituted by hypoid type gears, and the axis of the pinion gear 38 is arranged above the axis of the ring gear 36 with a so-called hypoid offset H. In addition, the pinion gear 38 is arranged so that its axis is raised frontward, whereby the bearing 40 that supports the shaft portion 38 a of the pinion gear 38 is positioned sufficiently below the rear rear shaft 8. The rear rear shaft housing 30 is filled with about 1/2 to ¼ of lubricating oil with respect to its overall height.

Further, a driven gear 42 that meshes with the drive gear 34 is attached to the tip of the shaft portion 38 a of the pinion gear 38. As a result, the driving force input to the input shaft 16 is transmitted to the differential of the rear rear shaft 8 via the drive gear 34, the driven gear 42, the pinion gear 38 and the ring gear 36.
3, the pinion gear 26 is disposed on the left side of the ring gear 24 with respect to the rear front shaft 6, while the pinion gear 38 is disposed on the right side of the ring gear 36 with respect to the rear rear shaft 8. Is arranged. This is because the rotation direction of the pinion gear 26 that drives the rear front shaft 8 is the same as the rotation direction of the pinion gear 38 that drives the rear rear shaft 8, so that the rear rear shaft 8 is in the same direction as the rear front shaft 6. This is a configuration necessary for rotation.

  According to the embodiment configured as described above, since the input shaft 32 of the rear rear shaft 8 is disposed above the rear rear shaft 8, the output shaft 20 supported by the rear front shaft housing 14 and The crossing angle between the intermediate shaft 12 and the crossing angle between the intermediate shaft 12 and the input shaft 32 supported by the rear rear shaft housing 30 can be set extremely small. Furthermore, the connecting portion between the input shaft 32 and the intermediate shaft 12 supported by the rear rear shaft housing 30 can be brought as close as possible to the rear rear shaft 8 as long as it does not interfere with the ring gear 36 of the rear rear shaft 8. The length of the intermediate shaft 12 can be set longer.

  Further, the drive gear 34 and the driven gear 42 of the rear rear shaft 8 are constituted by bevel gears, whereby the axis of the pinion gear 38 is inclined so as to rise forward toward the front of the vehicle. The bearing 40 that supports the bearing 38 can be disposed sufficiently below the rear rear shaft. Therefore, it is possible to obtain an appropriate tooth contact and engagement ratio between the pinion gear 38 and the ring gear 36 while ensuring the lubricity of the bearing 40 that supports the pinion gear 38.

In particular, in the present embodiment, the positional relationship between the pinion gear 26 and the ring gear 24 in the vehicle width direction is set opposite to the positional relationship between the pinion gear 38 and the ring gear 36 in the left-right direction. Since the 38 axes are offset upward with respect to the axis of the ring gear 36, appropriate tooth contact and engagement ratio can be obtained.
In other words, in the case of hypoid type pinion gears and ring gears that require offsets, it is necessary to contact the convex surface of the ring gear when the vehicle moves forward, so the torsion direction of the ring gear is automatically determined. Is done. If the axis of the pinion gear 38 is offset below the axis of the ring gear 36 under the determined conditions, the meshing rate of the pinion gear 38 with the ring gear 36 is reduced (at the same time). The disadvantage is that the number of meshing teeth is reduced).

  On the other hand, according to the present embodiment, since the axis of the pinion gear 38 is offset above the axis of the ring gear 36 as described above, it is desirable in the meshing between the pinion gear 38 and the ring gear 36. Thus, the lubricity of the bearing 40 of the pinion gear 38 can be ensured while ensuring the desired tooth contact and the desired meshing rate. In addition, as a supplementary explanation of the lubricity of the bearing 40, as described above, the lubricating oil in the rear rear shaft housing 30 adheres to the pinion gear 38 due to vibration during traveling, stirring by the ring gear 36 or the driven gear 42, or the like. The lubricating oil flows along the shaft portion 38 to reach the bearing 40. Accordingly, the lower the rear rear shaft housing 30 is, the more advantageous the lubricity.

The description of one embodiment according to the present invention is finished above, but the embodiment is not limited to the above, and various modifications can be made without departing from the spirit of the invention.
For example, in the above embodiment, the axes of the drive gear 34 and the driven gear 42 overlap in plan view as shown in FIG. 3, but the axes of the drive gear 34 and driven gear 42 are offset in plan view. It is also possible. In that case, it is necessary to provide the drive gear 34 and the driven gear 42 with a tooth shape that allows the offset.

  Moreover, in the said embodiment, although the pinion gear 38 and the ring gear 36 are hypoid gear types, a bevel gear type or a spiral bevel gear type can be adopted instead. In that case, the offset between the pinion gear 38 and the ring gear 36 is not required, but the bearing 40 that supports the pinion gear 38 is arranged more than the rear rear shaft 8 by arranging the pinion gear 38 so as to be lifted forward. It can be arranged sufficiently downward.

  Further, when the rotation direction of the pinion gear 26 that drives the rear front shaft 6 and the rotation direction of the output shaft 20 are configured to be the same, the positional relationship between the pinion gear 26 and the ring gear 24 in the vehicle width direction. However, it is not necessary to reversely set the positional relationship between the pinion gear 38 and the ring gear 36 in the left-right direction.

FIG. 1 is a side view showing an entire embodiment. FIG. 2 is an enlarged view of a main part of FIG. FIG. 3 is a view taken in the direction of arrow III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

Explanation of symbols

4 Motor 6 Rear front shaft 8 Rear rear shaft 12 Intermediate shaft 30 Rear rear shaft housing 32 Input shaft 34 Drive gear 36 Ring gear 38 Pinion gear 42 Driven gear

Claims (3)

After the rear front shaft housing that supports the rear front shaft of the rear two-shaft drive vehicle extends toward the rear of the vehicle above the rear front shaft and supports the output shaft for transmitting the driving force to the rear rear shaft In the drive shaft device of a two-axis drive vehicle,
A rear rear shaft housing for supporting the rear rear shaft;
An input shaft that is supported by the rear rear shaft housing, extends toward the front of the vehicle above the rear rear shaft, and receives driving force from the output shaft;
A drive gear mounted on the input shaft of the rear rear shaft behind the rear rear shaft;
A pinion gear that is supported by the rear rear shaft housing and is disposed behind the rear rear shaft and below the input shaft and meshes with a differential ring gear of the rear rear shaft. ,
A driven gear that is mounted on the shaft portion behind the pinion gear and meshes with the drive gear;
The drive shaft device for a rear two-shaft drive vehicle, wherein the drive gear and the driven gear are constituted by bevel gears, whereby the axis of the pinion gear is inclined so as to rise forward toward the front of the vehicle. . The rear rear axle differential ring gear and the pinion gear are constituted by hypoid gears,
2. The drive shaft device for a rear two-shaft drive vehicle according to claim 1, wherein an axis of the pinion gear is positioned above an axis of the rear rear shaft. A differential of the rear front shaft disposed in the rear front shaft housing, and a pinion gear that meshes with the ring gear of the differential in front and below the rear front shaft and rotates in a direction opposite to the output shaft. ,
The positional relationship in the vehicle width direction between the pinion gear and the ring gear of the rear rear shaft is opposite to the positional relationship in the vehicle width direction of the pinion gear and the ring gear of the rear front shaft. Drive shaft device for rear two-axis drive vehicle.

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