JP2001074058A - Power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce dimensions in the axial direction of a connecting part between an end of a drive shaft and a differential gear. SOLUTION: An opening part 6a of a differential case 6 of a differential gear 24, a boss part 7a of a differential gear case 7, a rolling bearing 9 (or 9') to support the differential gear case 7 (and an outside joint member 2) free to rotate against the differential case 6 and an oil seal 10 to seal the opening part 6a of the differential case 6 are arranged on an outside diameter part (an outside diameter part of a cup part) of the outside joint member 2. Additionally, a fitting surface 2d to fit the boss part 7a of the differential gear case 7, a sealing surface 2e on which a lip part of the oil seal 10 and a positional restricting part 2f to restrict a position in the axial direction of the oil seal 10 are provided on an outer diametrical part of the outside joint member 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for an automobile or the like, for example, an ATV (All Terrain Vehicle:
It is also called a saddle-ride type vehicle for traveling on uneven terrain or a four-wheel buggy. ) Is suitable for the power transmission device.

[0002]

2. Description of the Related Art FIG. 2 conceptually shows an ATV power transmission device. The power of the engine 21 is output from the front and rear output shafts via an internal transmission mechanism,
Power transmission means 22, such as a chain or a propeller shaft,
The signals are input to differentials 24 and 25 on the front and rear sides via the switch 23. Then, the engine power input to the differentials 24 and 25 is reduced by the mechanisms of the differentials 24 and 25, and
The rotation power is converted into right-angle rotation power and transmitted to wheels 28 and 29 via left and right drive shafts 26 and 27. In the example shown in the figure, the connection portion A between the drive shaft 26 on the front side and the differential 24, the wheel 2
A constant velocity universal joint is used for each of the connecting portions B with the reference numeral 8.
In some cases, a constant velocity universal joint may be used for the connecting portion C between the drive shaft 27 and the differential 25 on the rear side and the connecting portion D for connecting to the wheel 29. When propeller shafts are used as the power transmission means 22 and 23, connecting portions E and F between the propeller shaft and the output shaft of the engine (transmission mechanism) 21, and connecting portions G and H between the differentials 24 and 25 are respectively provided. In some cases, a speed universal joint is used.

FIG. 3 shows a drive shaft 2 on the front side.
6 is shown. The drive shaft 26 is connected with a sliding constant velocity so that the drive shaft 26 can take angular displacement and axial displacement by following the movement of the wheel 28 at the time of cornering traveling or rough terrain traveling. A universal joint (constant velocity universal joint permitting angular displacement and axial displacement between two axes) 30 and a fixed type constant velocity universal joint (constant velocity universal joint permitting angular displacement between two axes) 31 are paired. use. In the example shown in the figure, one end of the drive shaft 26 is connected to the differential 24 via a sliding constant velocity universal joint (double offset type constant velocity universal joint) 30 (connection part A), and the other end of the drive shaft 26 is connected. Is connected to the wheel 28 via a fixed type constant velocity universal joint (Zepper type constant velocity universal joint: ball fixed joint) 31 (connection part B).

FIG. 4 shows a connecting portion A between one end of the drive shaft 26 and the differential 24. One end of the drive shaft 26 is serrated (or spline-fitted) to the inner joint member 32 of the sliding constant velocity universal joint 30, and the outer joint member 33 of the sliding constant velocity universal joint 30 is fitted.
Shaft part 33a is the differential case 3 of the differential 24.
4 and the boss 3 of the differential gear case 35
5a, serration fit (or spline fit) with the side gear 36. The opening 34a of the differential case 34, the boss 35a of the differential gear case 35, and the differential gear case 35 (and the outer joint member 33) are attached to the outer diameter of the shaft portion 33a of the outer joint member 33.
Bearing 37 rotatably supported with respect to the oil seal 3 for sealing the opening 34a of the differential case 34
8 are arranged.

[0005] The power from the engine 21 is input to a drive pinion gear (not shown) of the differential 24, and the drive pinion gear → a ring gear (not shown) →
The power is transmitted to the wheel 28 through the path of the differential gear case 35 → pinion gear (not shown) → side gear 36 → slidable constant velocity universal joint 30 → drive shaft 26 → fixed constant velocity universal joint 31.

[0006]

The power transmission device of the ATV follows the large movement of the wheel at the time of running on rough terrain or the like. Therefore, the angular displacement and the axial direction of the drive shaft coupling constant velocity universal joint are larger than those of a passenger car or the like. Large displacement. On the other hand, the amount of angular displacement and the amount of axial displacement of the constant velocity universal joint can be alleviated by increasing the length of the drive shaft.
The span between the differential and the wheel cannot be changed significantly. Therefore, it is important to design the connecting portion by the constant velocity universal joint to reduce the axial dimension.

However, in the conventional configuration shown in FIG. 4, the opening 34a of the differential case 34, the boss 35a of the differential gear case 35, the rolling bearing 37, and the oil seal 38 are formed with the outer diameter of the shaft 33a of the outer joint member 33. Therefore, it is necessary to secure an axial space for arranging these elements in the shaft portion 33a, and there is a problem that the axial dimension of the connecting portion A is correspondingly increased.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the axial dimension of a connecting portion of a drive shaft by a constant velocity universal joint, in particular, a connecting portion between a drive shaft and a differential by a sliding type constant velocity universal joint. An object of the present invention is to reduce the amount of angular displacement and the amount of axial displacement of a universal joint, thereby contributing to the improvement of running performance of a vehicle and reducing the weight.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method of connecting one end of a drive shaft to a sliding type constant velocity universal joint and an outer joint member of the sliding type constant velocity universal joint. In a power transmission device having a shaft connected to a side gear of a differential, an opening of a differential case of the differential, a boss of a differential gear case, and a rolling bearing rotatably supporting the differential gear case with respect to the differential case, A configuration is provided in which an outer joint member of a sliding type constant velocity universal joint is arranged at an outer diameter portion.

As the above-mentioned sliding type constant velocity universal joint, a double offset type constant velocity universal joint, a tripod type constant velocity universal joint and the like can be used, and a double offset type constant velocity universal joint is particularly preferable. The double offset type constant velocity universal joint has an outer joint member in which a plurality of linear guide grooves are formed in the cylindrical inner diameter surface in the axial direction, and a plurality of linear guide grooves in the spherical outer diameter surface in the axial direction. An inner joint member formed in the above, a torque transmitting ball incorporated between the guide groove of the outer joint member and the corresponding guide groove of the inner joint member, and a retainer for holding the torque transmitting ball, The device has a pocket for accommodating and holding each torque transmission ball, a partially spherical outer diameter surface which is guided in contact with the inner diameter surface of the outer joint member,
A partial spherical inner diameter surface that is contact-guided to the outer diameter surface of the inner joint member, and the spherical center of the partial spherical outer diameter surface and the spherical center of the partial spherical inner diameter surface are positioned with respect to the axial center of the pocket. Are offset to the opposite side by the same distance in the axial direction.

The other end of the drive shaft is connected to the wheel via a fixed constant velocity universal joint. The type of the fixed type constant velocity universal joint is not particularly limited. For example, a Zepper type constant velocity universal joint (ball-fixed joint) can be used. The Zepper type constant velocity universal joint has an outer joint member in which a plurality of curved guide grooves are formed in the spherical inner surface in the axial direction, and a plurality of curved guide grooves in the spherical outer surface in the axial direction. An outer joint comprising: a formed inner joint member; a torque transmission ball incorporated between a guide groove of the outer joint member and a corresponding guide groove of the inner joint member; and a retainer holding the torque transmission ball. The center of curvature of the guide groove of the member and the center of curvature of the guide groove of the inner joint member are offset by the same distance in the axial direction with respect to the joint center plane including the center of the torque transmitting ball, and the ball track is moved in the axial direction. In the shape of a wedge.

In the above configuration, the oil seal for sealing the opening of the differential case can be arranged on the outer end side of the rolling bearing. Also, in the outer diameter portion of the outer joint member,
A seal surface with which the oil seal slides can be provided, and further, a position regulating portion for regulating an axial position of the oil seal can be provided on an outer diameter portion of the outer joint member. Alternatively, an oil seal can be directly attached to the outer end of the rolling bearing (sealed rolling bearing). The sealing performance can be improved by using a sealed rolling bearing together with the oil seal, or the oil seal can be omitted by using a sealed rolling bearing.

[0013]

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

FIG. 1 shows a connecting portion A in the power transmission device of the ATV shown in FIG.
Is connected to a differential 24 via a sliding constant velocity universal joint, for example, a double offset type constant velocity universal joint 1.

The constant velocity universal joint 1 includes an outer joint member 2 having a plurality of linear guide grooves 2b formed in a cylindrical inner diameter surface 2a in an axial direction, and a plurality of linear joints formed in a spherical outer diameter surface 3a. A plurality of torques arranged on a ball track formed by the inner joint member 3 having the guide groove 3b formed in the axial direction and the guide groove 2b of the outer joint member 2 and the guide groove 3b of the inner joint member 3 cooperating with each other. It comprises a transmission ball 4 and a retainer 5 for holding the torque transmission ball 4. The retainer 5 has a partially spherical outer diameter surface 5a guided in contact with the inner diameter surface 2a of the outer joint member 2, a partially spherical inner diameter surface 5b in contact with the outer diameter surface 3a of the inner joint member 3, and a torque. This is an annular body including a plurality of pockets 5c for housing and holding the transmission ball 4. The spherical center O1 of the partial spherical outer diameter surface 5a and the spherical center O2 of the partial spherical inner diameter surface 5b are offset by the same distance in the axial direction with respect to the axial center O of the pocket 5c. When the constant velocity universal joint 1 transmits the rotational torque while maintaining the operating angle θ, the retainer 5 rotates to the position of the torque transmitting ball 4 moving on the ball track according to the inclination of the inner joint member 3, The torque transmitting ball 4 is held on an angle bisector (θ / 2) of the operating angle θ. Thereby, the constant velocity of the joint is ensured. Further, when the outer joint member 2 and the inner joint member 3 relatively move in the axial direction, a slip occurs between the partially spherical outer diameter surface 5a of the retainer 5 and the inner diameter surface 2a of the outer joint member 2, and a smooth movement occurs. Enables axial sliding (plunging).

One end of the drive shaft 26 is serrated (or splined) with the inner joint member 3 of the constant velocity universal joint 1. The shaft portion 2c of the outer joint member 2 of the constant velocity universal joint 1 is serrated (or spline-fitted) to the side gear 8 of the differential 24.

The rolling bearing 9 (which rotatably supports the opening 6 a of the differential case 6 of the differential 24, the boss 7 a of the differential gear case 7, and the differential gear case 7 (and the outer joint member 2) with respect to the differential case 6. Or 9 '), and an oil seal 10 for sealing the opening 6a of the differential case 6.
Is disposed at the outer diameter portion of the outer joint member 2 (the outer diameter portion of the cup portion). The oil seal 10 is disposed on the outer end side of the rolling bearing 9 (or 9 '). Outer joint member 2
The boot 11 is mounted on the outer diameter portion of the drive shaft 26 and the outer diameter portion of the drive shaft 26, and is fixed by a boot band.
In FIG. 1, a portion above the axis is a rolling bearing 9.
Shows a configuration using a ball bearing such as a deep groove ball bearing, and the portion below the axis shows a configuration using a roller bearing such as a needle roller bearing as the rolling bearing 9 ′. By using a needle roller bearing as the rolling bearing 9 ', the outer diameter of the differential case 6 can be reduced.

A fitting surface 2d for fitting the boss 7a of the differential gear case 7 and a lip of the oil seal 10 are provided on the outer diameter portion of the outer joint member 2 (the outer diameter portion of the cup portion). A sealing surface 2e that slides and a position regulating portion 2f that regulates the axial position of the oil seal 10 are provided. The fitting surface 2d and the sealing surface 2e are smoothly finished by grinding or the like. In this embodiment, the position restricting portion 2f is formed integrally with the outer diameter portion of the outer joint member 2 in a flange shape.

The oil seal can be directly mounted on the outer end of the rolling bearing. That is, the rolling bearing 9
(Or 9 ') can be used as a sealed type, whereby the sealing performance is improved in combination with the oil seal 10 in FIG.
It is possible to omit 0.

The other end of the drive shaft 26 (not shown) is connected to a wheel (28) via a fixed type constant velocity universal joint, for example, a Zepper type constant velocity universal joint (31) shown in FIG.
(The connection portion B shown in FIG. 2).

The power from the engine (21) is input to a drive pinion gear (not shown) of the differential 24, and the drive pinion gear → a ring gear (not shown).
→ Differential gear case 7 → Pinion gear (not shown) → Side gear 8 → Sliding constant velocity universal joint 1 → Drive shaft 2
6 → fixed constant velocity universal joint (31) → wheel (28).

According to this embodiment, the opening 6 a of the differential case 6, the boss 7 a of the differential gear case 7, the rolling bearing 9 (or 9 ′), and the oil seal 10 are connected to the outer diameter portion of the outer joint member 2. (Outer diameter portion of the cup portion), so that the shaft portion 2c of the outer joint member 2 is different from the conventional configuration shown in FIG.
, The axial dimension of the connecting portion A by the sliding constant velocity universal joint 1 can be reduced. Thereby, without changing the span between the differential 24 and the wheel (28), the length of the drive shaft 26 is increased, and the angular displacement and the axial displacement of the sliding constant velocity universal joint 1 are increased. It is possible to reduce the amount of angular displacement of the fixed type constant velocity universal joint (31). In addition, the reduction in the length of the shaft portion 2c leads to a reduction in the weight of the sliding type constant velocity universal joint 1 and a reduction in the weight of the power transmission device.

The present invention can be applied not only to the front side but also to the connecting portion (C) between the drive shaft (7) on the rear side and the differential (25) in FIG.

[0024]

The present invention has the following effects.

(1) An opening of a differential case of a differential, a boss of a differential gear case, and a rolling bearing rotatably supporting the differential gear case with respect to the differential case are formed by a sliding type constant velocity universal joint. Since it is arranged at the outer diameter of the outer joint member, the length of the shaft portion of the outer joint member is shortened as compared with the conventional configuration, and the axial dimension of the connecting portion of the drive shaft by the sliding constant velocity universal joint is reduced. Can be reduced.

(2) Due to the effect of the above (1), the length of the drive shaft is increased without changing the span between the differential and the wheel, and the angular displacement and the angular displacement of the sliding type constant velocity universal joint are increased. The axial displacement and the angular displacement of the fixed type constant velocity universal joint that connects the other end of the drive shaft can be reduced. As a result, the traveling performance when traveling on uneven terrain having a large undulation or a narrow curved road is improved.

(3) By the effect of the above (1), the weight of the power transmission device can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a connecting portion between one end of a drive shaft and a differential.

FIG. 2 is a conceptual diagram of an ATV power transmission device.

FIG. 3 is a sectional view showing a drive shaft.

FIG. 4 is a cross-sectional view showing a connecting portion between one end of a drive shaft and a differential in a conventional configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sliding constant velocity universal joint 2 Outer joint member 2a Inner diameter surface 2b Guide groove 2c Shaft part 2e Seal surface 2f Position control part 3 Inner joint member 3a Outer diameter surface 3b Guide groove 4 Torque transmission ball 5 Cage 5a Partially spherical shape Outer surface 5b Partially spherical inner surface 5c Pocket 6 Differential case 6a Opening 7 Differential gear case 7a Boss 8 Side gear 9 Rolling bearing 9 'Rolling bearing 10 Oil seal 24 Differential 26 Drive shaft

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Kusunoki 1578 Higashikaizuka, Iwata-shi, Shizuoka F-term in NTN Corporation (reference) 3D042 AA01 AA06 AB01 CA03 CB02 CB03 CB11

Claims (6)

[Claims] 1. A power transmission device in which one end of a drive shaft is connected to a sliding constant velocity universal joint, and a shaft portion of an outer joint member of the sliding constant velocity universal joint is connected to a differential side gear. An outer joint member of the sliding type constant velocity universal joint, comprising: an opening of a differential case of a differential; a boss of a differential gear case; and a rolling bearing rotatably supporting the differential gear case with respect to the differential case. A power transmission device, wherein the power transmission device is disposed at an outer diameter portion of the power transmission device. 2. The sliding type constant velocity universal joint according to claim 1, wherein said outer joint member has a plurality of linear guide grooves formed in a cylindrical inner diameter surface in an axial direction, and a plurality of linear joint grooves have a spherical outer diameter surface. Inner joint member having the guide groove formed in the axial direction, a torque transmitting ball incorporated between the guide groove of the outer joint member and the corresponding guide groove of the inner joint member, and a holding member for holding the torque transmitting ball. A cage for accommodating and holding each of the torque transmitting balls, a partially spherical outer diameter surface guided in contact with an inner diameter surface of the outer joint member, and an outer diameter of the inner joint member. A partially spherical inner diameter surface guided in contact with the surface, wherein the spherical center of the partial spherical outer diameter surface and the spherical center of the partial spherical inner diameter surface are in the axial direction with respect to the axial center of the pocket. 2. The method of claim 1, wherein the first and second sides are offset by an equal distance from each other. The power transmission device as described in the above. 3. The power transmission device according to claim 1, wherein an oil seal for sealing an opening of the differential case is disposed on an outer end side of the rolling bearing. 4. A seal surface with which the oil seal slides is provided on an outer diameter portion of the outer joint member.
The power transmission device as described in the above. 5. The power transmission device according to claim 3, wherein a position regulating portion for regulating an axial position of the oil seal is provided at an outer diameter portion of the outer joint member. 6. The power transmission device according to claim 1, wherein an oil seal is attached to an outer end of the rolling bearing.