JPH1071865A - Power transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the rotational deflection of a sealed type viscous fluid coupling by correctly aligning the axis of the seal type viscous fluid coupling with the axis of a rotary shaft without employing a complicate means such as splitting the rotary shaft into two parts when the seal type viscous fluid coupling is attached to the rotary shaft of a power transmission device. SOLUTION: In a power transmission mechanism, a rotary shaft 10 of a power transmission device 1 is rotatably supported on a plurality of bearings 6 arranged in a housing case 13 of the power transmission device 1, and a seal type viscous fluid coupling 2 is externally fitted to the rotary shaft 10 so as to be arranged in series with a plurality of bearings 6 along the axial direction of the rotary shaft 1. A tightening nut 8 to position and hold each bearing 6 relative to the rotary shaft 10 is screwed at the position the seal type viscous fluid coupling 2 and the bearing 6, and the seal type viscous fluid coupling 2 is prevented from being detached from the rotary shaft 10 by a detachment-preventing member 9 fitted to one end part of the rotary shaft 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission mechanism, and more specifically, a viscous fluid-sealed coupling with a rotary shaft as an output shaft of a transfer of a four-wheel drive vehicle or a rotary shaft as an input shaft of a final reduction gear (rear differential). The present invention relates to a power transmission mechanism having a structure equipped with a.

[0002]

2. Description of the Related Art Conventionally, as this kind of power transmission mechanism,
For example, there is one described in Japanese Patent Publication No. 4-62892. In this prior art, as shown in FIG. 1 of the publication, a rotary shaft (drive pinion shaft) as an output shaft of a transfer is arranged at a fixed interval via a spacer in a housing case. The bearing is rotatably supported by two bearings, and a sealed viscous fluid coupling is externally fitted to one end of the rotating shaft. Further, each of the two bearings, the spacer, and the sealed viscous fluid coupling are arranged in series along the axial length direction of the rotating shaft, and the positioning and holding of each member is performed at one end of the rotating shaft. The sealing type viscous fluid coupling is pressed in the direction of each of the bearings and the spacers by a tightening force of a screw nut.

According to the above configuration, by connecting the propeller shaft to the sealed viscous fluid coupling, the rotating shaft of the transfer and the propeller shaft can be connected via the sealed viscous fluid coupling, and the rotating shaft and the propeller can be connected. By generating a differential between the shaft and the shaft, a difference in rotational speed between the front wheel and the rear wheel of the four-wheel drive vehicle can be generated. Also,
The operation of positioning each of the two bearings, the spacer, and the sealed viscous fluid coupling in the axial direction of the rotary shaft can be easily performed by tightening one tightening nut.

[0004]

However, the conventional power transmission mechanism has the following disadvantages.

That is, in the prior art, 2
As a means for positioning and holding each of the three bearings, spacers, and sealed viscous fluid coupling, the above-mentioned members are brought into a series by tightening the so-called rearmost sealed viscous fluid coupling with a tightening nut. If there is a processing error in the mounting part of each of the two bearings and spacers located on the side of the sealed viscous fluid joint, the sealed viscous fluid will accumulate in the form of accumulation of these processing errors. There is a possibility that large in-row runout (runout in a direction intersecting with the axial length direction of the rotating shaft) may occur in the hermetically sealed viscous fluid joint in the fitting portion of the joint. More specifically, in the conventional power transmission mechanism, each of the two bearings, the spacer, and the sealed viscous fluid coupling has a structure in which the end faces adjacent to each other come into contact with each other to perform positioning and holding with respect to the rotating shaft. Therefore, if there is an error in the parallelism between the end faces of the bearings and spacers that are in contact with each other, these errors in the parallelism extend to the mounting part of the sealed viscous fluid coupling, and The axis of the fluid coupling is inclined with respect to the axis of the rotating shaft. Therefore, conventionally,
The shaft center between the rotating shaft and the sealed viscous fluid joint is apt to occur, and when a propeller shaft is connected to the sealed viscous fluid joint, the propeller shaft is liable to generate rotational runout. As a result, in the related art, there has been a problem that vibration and noise of the vehicle body due to the rotational vibration of the propeller shaft increase.

Conventionally, there is a means shown in FIG. 1 of Japanese Utility Model Publication No. Hei 5-1696 as means for solving the above-mentioned problem. This means divides the rotary shaft of the transfer into a first rotary shaft and a second rotary shaft, and supports the first rotary shaft with two bearings. This is a structure in which positioning is performed by a tightening nut screwed to the rotating shaft. The second rotating shaft has a hermetically sealed viscous fluid coupling externally fitted thereto, and has a structure in which the second rotating shaft is spline-fitted to the first rotating shaft. According to such a configuration, the sealed viscous fluid coupling is moved relative to the second rotation shaft by the first rotation shaft.
Because it can be positioned and held independently of the bearing that supports the rotating shaft of the shaft, it is possible to avoid the accumulation of machining dimensional errors such as bearings and spacers from reaching the mounting part of the sealed type viscous fluid coupling. it can.

However, in the means described in Japanese Utility Model Publication No. H5-1696, the rotating shaft is connected to the first rotating shaft and the second rotating shaft.
Since the rotation shaft is divided into two, the machining cost of the two-part rotation shaft becomes extremely high.
Further, when the second rotating shaft is spline-fitted to the first rotating shaft, the alignment of the two rotating shafts cannot always be performed with high precision, and the machining of these two rotating shafts is not always possible. Due to the error, the two rotating shafts are displaced from each other, and the axis of the hermetically sealed viscous fluid coupling externally fitted to the second rotating shaft is displaced from the first rotating shaft. There is a new fear. Therefore, the actual fairness 5-169
No. 6, it is difficult to appropriately prevent the rotational runout of the sealed viscous fluid joint by simple means.

The present invention has been conceived in view of such circumstances, and when a hermetically sealed viscous fluid coupling is mounted on a rotating shaft of a driving force transmission device such as a transfer or a final reduction device, The shaft center of the sealed viscous fluid coupling can be accurately matched with the shaft center of the rotating shaft without employing a complicated means such as dividing the rotating shaft into two parts. It is an object to suppress rotational runout.

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, according to the present invention, the rotating shaft of the driving force transmitting device is rotatably supported by a plurality of bearings disposed in a housing case of the driving force transmitting device, and the rotating shaft includes: A power transmission mechanism, wherein a hermetically sealed viscous fluid coupling is externally mounted so as to be arranged in series with the plurality of bearings along the axial direction of the rotating shaft, wherein the sealed shaft is At a position between the mold-type viscous fluid coupling and the bearing, a tightening nut for screwing and mounting the respective bearings with respect to the rotating shaft is screwed and mounted. Is characterized in that a retaining member attached to one end of the rotary shaft prevents the rotary shaft from being removed.

In the present invention, the positioning and holding of each bearing with respect to the rotating shaft can be achieved by tightening the tightening nut disposed at a position between the sealed viscous fluid coupling and the bearing. The tightening force of the tightening nut does not affect the sealed viscous fluid joint, and the sealed viscous fluid joint is rotated independently of the bearing by a retaining member attached to one end of the rotating shaft. The shaft can be appropriately positioned and held at a predetermined position on the shaft. Therefore, the conventional Japanese Patent Publication No. 4-6289
Unlike the means described in Japanese Unexamined Patent Publication No. 2 (1993), even when there is a processing dimensional error in a bearing mounting portion or the like,
Accumulation of these errors does not adversely affect the mounting position of the sealed viscous fluid coupling, and the axis of the sealed viscous fluid coupling can be accurately matched with the axis of the rotating shaft. As a result, according to the present invention, it is possible to reduce the rotational vibration of the sealed viscous fluid coupling and, consequently, the rotational vibration of the propeller shaft and the like connected to the sealed viscous fluid coupling, thereby suppressing the generation of vehicle vibration and noise. The special effect that can be obtained is obtained.

Further, the present invention employs a structure in which a sealed viscous fluid coupling is externally fitted to a rotating shaft supported by bearings. Differently, since the rotating shaft of the driving force transmission device is not divided into two parts, the first rotating shaft and the second rotating shaft, an error in connecting the two divided rotating shafts to each other causes There is no danger that rotational vibration occurs in the hermetically sealed viscous fluid coupling. Moreover, the manufacture of the rotating shaft is easy, and the cost of parts can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a sectional view of an essential part showing an example of a power transmission mechanism according to the present invention. FIG. 2 is a schematic explanatory view showing a drive system of a four-wheel drive vehicle provided with the power transmission mechanism shown in FIG.

The power transmission mechanism shown in FIG.
A sealed viscous fluid coupling 2 is externally fitted to a rotating shaft 10 as an input shaft of a (rear differential). The final reduction gear 1 is provided with a differential gear mechanism, and as shown in FIG. 2, transmits a driving force to drive shafts 52, 52 on which rear wheels W2, W2 of a four-wheel drive vehicle are mounted. It is for. The hermetically sealed viscous fluid coupling 2 includes the rotating shaft 1
0 and the rear end of the propeller shaft 3 are interconnected. The front end of the propeller shaft 3 is
The output of the engine 50 is transmitted to the transfer 4 via a transmission 51. The transfer 4 distributes the rotational force also to the front wheels W1 and W1.

In FIG. 1, the rotating shaft 10 is generally called a drive pinion shaft. One end 10a has a pinion gear meshing with a bevel gear 12 constituting a differential gear mechanism of the final reduction gear 1. 11 are continuously provided. One end 10a and a substantially central portion in the longitudinal direction of the rotating shaft 10 are rotatably supported by two bearings 6, 6 (6a, 6b) arranged at a constant interval. The outer races (outer races) of the bearings 6 and 6 are respectively fitted in annular concave portions 14a and 14b of a cylindrical portion 13a formed by the housing case 13 of the final transmission 1. On the other hand, the inner races (inner races) of the bearings 6 and 6 are externally fitted to the rotary shaft 10 with a spacer 7 interposed therebetween. A male screw portion (not shown) is provided on one side of the bearing 6 (6b) located at a substantially central portion in the longitudinal direction of the rotary shaft 10 in the rotary shaft 10, and the male screw portion is provided. Is screwed with a tightening nut 8. The tightening nut 8 is for positioning and holding the inner rings of the bearings 6 and 6 with respect to the rotating shaft 10.
By tightening the tightening nut 8, the above 2
The two bearings 6, 6 and the spacer 7 are pressed in the direction of one end 10a of the rotating shaft 10 to be positioned and held.

As an example of the tightening nut 8, a flanged nut having a flange 80 is used so that one end surface of the inner ring of the bearing 6 (6b) can be appropriately pressed. If necessary, a washer 15 having an appropriate thickness is interposed between the flange portion 80 of the tightening nut 8 and the inner ring of the bearing 6 (6b). By changing the thickness of the washer 15, the tightening position of the tightening nut 8 can be appropriately adjusted.

As the hermetically sealed viscous fluid coupling 2, a so-called viscous coupling can be used. The general configuration of the hermetically sealed viscous fluid coupling 2 is as follows. A housing 21 is rotatably fitted to an inner shaft 20 and, for example, a silicone oil is inserted into a space 22 formed between the inner shaft 20 and the housing 21. Such a viscous fluid is sealed. In the space 22, a plurality of outer plates and inner plates that receive the viscous resistance of the viscous fluid are also provided. This sealed type viscous fluid coupling 2 includes an inner shaft 2
When a rotational force is transmitted to one of the housing 0 and the housing 21, the rotational force is transmitted to the other through a viscous fluid. Is possible. This sealed viscous fluid coupling 2
The inner shaft 20 is located on a portion of the rotating shaft 10 closer to the other end 10b of the rotating shaft 10 than the fastening nut 8 is.
Is externally fitted to the rotary shaft 10. The inner shaft 20 is spline-fitted so as not to rotate relative to the rotating shaft 10, and rotates in conjunction with the rotating shaft 10.

The other end 10b of the rotary shaft 10 is provided with a snap ring 9 for positioning and holding an inner ring of a bearing 23 for assisting the rotation of the housing 21.
The snap ring 9 serves to prevent the sealing type viscous fluid coupling 2 from coming off the rotary shaft 10 by positioning and holding the bearing 23. Accordingly, the sealed viscous fluid coupling 2 is positioned and held between the snap ring 9 and the tightening nut 8. It is not in the state of being tightened in the direction.

In the power transmission mechanism having the above structure, the two bearings 6 and 6 can be positioned and held by tightening the tightening nut 8, and the rotating shaft 10 is appropriately supported by the bearings 6 and 6. can do. On the other hand, the tightening nut 8 is
The sealing type viscous fluid coupling 2 is positioned only between the tightening nut 8 and the snap ring 9 separately from the tightening of the tightening nut 8. I have. Therefore, the longitudinal positioning of the rotary shaft 10 of the sealed viscous fluid coupling 2 can be performed irrespective of the positioning of the bearings 6, 6 and the like. It does not reach the mounting portion of the hermetically sealed viscous fluid coupling 2. As a result, the axis of the sealed viscous fluid coupling 2 can be accurately aligned with the axis of the rotating shaft 10, and rotational vibration of the sealed viscous fluid coupling 2 can be eliminated. The propeller shaft 3 is connected to the housing 21 of the sealed viscous fluid coupling 2.
Can also be suppressed, which is advantageous in preventing vibration and noise.

In the power transmission mechanism, two bearings 6, 6,
Since the spacer 7 and the hermetically sealed viscous fluid coupling 2 are externally fitted in the form of a series arranged in series, the assembling work of these members is also facilitated. Further, the rotating shaft 10 is formed of a single member, for example, the rotating shaft 10
Is not divided into two parts, the number of parts can be reduced as a whole, and there is an advantage that the manufacturing cost can be reduced.

In the above embodiment, the case where the sealed viscous fluid coupling 2 is externally fitted to the rotary shaft 10 as the input shaft of the final reduction gear 1 has been described as an example, but the present invention is not limited to this. . In the present invention, for example, as shown in FIG.
However, the present invention can also be applied to a case where the hermetically sealed viscous fluid coupling 2 is externally fitted. Therefore, the driving force transmission device according to the present invention may be either a final reduction device or a transfer. Further, the rotating shaft of the driving force transmission device is not necessarily limited to the drive pinion shaft, and may be a rotating shaft having a pinion gear at one end.

Further, in the above embodiment, a snap ring is used as a means for preventing the hermetic type viscous fluid coupling from coming off, but the present invention is not limited to this.
A member other than the snap ring may be used as the retaining member according to the present invention.

In addition, the specific configuration of each part of the power transmission mechanism according to the present invention is not limited to the above-described embodiment, and can be variously changed in design. The specific configuration of the sealed viscous fluid coupling is not particularly limited.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an example of a power transmission mechanism according to the present invention.

FIG. 2 is a schematic explanatory view showing a drive system of a four-wheel drive vehicle including the power transmission mechanism shown in FIG.

FIG. 3 is a schematic explanatory view showing another example of a drive system of a four-wheel drive vehicle including a power transmission mechanism according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Final reduction gear (drive power transmission device) 2 Sealed viscous fluid coupling 4 Transfer (drive power transmission device) 6 Bearing 7 Spacer 8 Tightening nut 9 Snap ring (Retaining member) 10 Rotary shaft 13 Housing case 40 Rotary shaft

Claims (1)

[Claims] 1. A rotating shaft of a driving force transmitting device is rotatably supported by a plurality of bearings disposed in a housing case of the driving force transmitting device, and a sealed viscous fluid is provided on the rotating shaft. A power transmission mechanism in which a joint is externally fitted so as to be arranged in series with the plurality of bearings along the axial direction of the rotating shaft, wherein the sealed viscous fluid coupling of the rotating shaft At a position between the bearing and the bearing, a tightening nut for screwing and mounting the respective bearings with respect to the rotating shaft is screwed, and the sealed viscous fluid coupling is A power transmission mechanism, wherein a retaining member attached to one end of the shaft prevents the rotation shaft from being removed.