JPH0445703B2 - - Google Patents

Abstract

PURPOSE:To adjust the preload onto the bearing of a drive pinion shaft of a differential device by driving a preload member screwed over the drive pinion shaft to apply the axial load onto the bearing member. CONSTITUTION:A hypoid gear 10 integral with the shaft member 1 will gear with a ring gear 11 secured to a defcase. A coupling member 6 is spline fitted to the shaft member 1 then fixed through a nut 8 while journaled by bearing members 13, 14. Preload is applied onto the bearing members 13, 14 by driving a ring member 21 screwed over the screw section 20 of the shaft member 1.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a straddle mounting structure that supports a drive pinion shaft that constitutes the final gear of an automobile on both sides, and particularly relates to a straddle mounting structure to which a propeller shaft or the like is connected. A preload is used to apply a predetermined bearing pressure to a bearing member that is provided to rotatably support the input side of the drive pinion shaft from its outer circumferential side (radially outward of the drive pinion shaft). The load obtained by dispersing part of the shaft load applied in the axial direction outward in the radial direction) can be easily and accurately adjusted, and the time required to assemble the drive pinion shaft is reduced. The present invention relates to a straddle mounting structure for a drive pinion shaft that can be shortened in width and improve work efficiency.

[Technical background of the invention and its problems]

Generally speaking, in the case of automobiles, especially large trucks and buses, the drive and pinion shafts are rotatably supported at the input side, which is connected to the propeller shaft, and at the output side, which is connected to the differential gear. It uses a structure called straddle mounting that supports both sides.

Conventionally, as this type of straddle mounting structure for a drive pinion shaft, the structure shown in FIG. 1 is known.

Reference numeral 1 denotes a drive pinion shaft that is provided both inside and outside the differential case 3 in which the differential device 2 is incorporated, and is used to transmit the rotational driving force of a propeller shaft, etc., to the differential device 2. The pinion shaft 1 is rotatably attached to a pinion cage 4 that partitions and closes a differential case 3. An input flange 6 is provided at one shaft-shaped end of the drive pinion shaft 1 constituting the input rotating section 5 to connect it to a propeller shaft or the like. This input flange 6
is fitted with the drive pinion shaft 1 by a spline, and is fixed by the fastening force of a nut 8 screwed onto the drive pinion shaft 1 via a washer 7 that engages with the washer 7. On the other hand, a hypoid gear 10 is integrally provided at the other end of the drive pinion shaft 1 forming the output rotating section 9.
A ring gear 11 connected to the differential device 2 is meshed with the hypoid gear 10. The drive pinion shaft 1 configured in this way is
The output rotating part 9 is the differential case 3
It is supported by a bearing member 12 on the inside, and its input rotating part 5 is provided inside the pinion cage 4 from the radially outer side between the hypoid gear 10 and the input flange 6. Ta2
It is supported by two bearing members 13 and 14. Such a double-sided support structure is called a straddle mounting structure. In particular, the input-side bearing members 13 and 14 are press-fitted inside the pinion cage 4 from opposite directions, and are arranged circumferentially at different levels inside the pinion cage 4 in order to support the drive pinion shaft 1 at a predetermined distance. They are engaged with the provided flange-like engaging portions 4a, and are spaced apart from each other by a predetermined span S. These bearing members 13,1
4, a ring-shaped distance piece 15 and a shim 16 are stacked to fill the span S, and extend from the base end 6a of the input flange 6 to the shoulder 10a of the hypoid gear 10. are connected by engaging in series. Furthermore, these bearing members 13 and 14 disperse a part of the axial load L applied along the axial direction of the drive pinion shaft 1 by tightening the nut 8 in the radial direction to form a preload P, and the pinion - In order to obtain bearing pressure by taking a reaction force to the cage 4 or the hypoid gear 10, it is equipped with a tapered roller 17 and forms a bearing surface 18 that is inclined with respect to the axial direction of the drive pinion shaft 1. .

To explain the assembly work of such a straddle mounting structure for the drive pinion shaft, first, one of the bearing members 13 is press-fitted inside the pinion cage 4 which has been removed from the differential case 3. , the distance piece 15 and the shim 16 are laminated from the other side, and the other bearing member 14 is press-fitted to form a bearing body. After that, drive pinion shaft 1
is press-fitted into the pinion cage 4 from the input rotating part 5 side. Thereafter, the input flange 6 is fitted into the input rotating part 5, and the nut 8 is screwed onto the drive pinion shaft 1 via the washer 7. When the nut 8 is tightened, the tightening force is
Input flange 6 to hypoid gear 10
While pressing the bearing members 13 and 14 to the roller retainers 19 . . . , an axial load L along the axial direction of the drive pinion shaft 1 is applied. Most of this axial load L acts between the input flange 6 and the hypoid gear 10 via the shims 16 laminated on the span S and the distance piece 15, and acts as a reaction force on them. The input flange 6 is fixed to the drive pinion shaft 1 with a predetermined fastening force. In this regard,
The bearing members 13 and 14 are attached to their roller retainers 1
A part of the axial load L acting on the pinion cage 4 and the hypoid is dispersed radially outward by the inclined bearing surface 18 through the tapered roller 17 and acts as a preload P.・
It is configured to apply a reaction force to the gears 10 to obtain a predetermined bearing pressure on their bearing surfaces 18.

By the way, in the conventional straddle mounting structure of the drive pinion shaft, the bearing members 13 and 14 are already press-fitted inside the pinion cage 4 and are stacked in the narrow span S between the bearing members 13 and 14, which cannot be easily removed. The shims 16 and the distance pieces 15 play an important role in determining the bearing pressure on the bearing surfaces 18. That is, when these are arranged loosely in the span S, there is a margin between the roller retainers 19 of the bearing members 13 and 14, and the shaft load L, which is large by that margin, is applied to the bearing surface 18.
On the other hand, if the bearings are closely arranged, most of the shaft load L will act along the axial direction of the drive pinion shaft 1. As a result, the predetermined bearing pressure cannot be applied to the bearing surfaces 18 of the tapered rollers 17, and the bearing members 13 and 14 become loose and the hypoid gear 10 and ring gear 1 are damaged.
This may cause abnormal tooth contact with the drive pinion shaft 1 or cause the entire drive pinion shaft 1 to swing violently. In particular, when assembling the drive pinion shaft 1, the input flange 6, which is connected to the propeller shaft, etc., must be carefully placed to prevent it from coming off the drive pinion shaft 1 due to severe vibrations when the vehicle is being driven. Although the shaft is normally fastened with a tightening torque of approximately 10 tons, it is ideal that the bearing pressure that utilizes a portion of the shaft load L is approximately 1/20 of that. In this way, in order to obtain a small predetermined bearing pressure from a large shaft load, the shims 16, etc., interposed in the span S have a significant influence. Furthermore, this span S is
3, 14 themselves, i.e. the taper roller 17...
and roller retainer 19, etc., and individual product variations based on their assembly tolerances, processing tolerances of the engaging portion 4a of the pinion cage 4, drive pinion shaft 1, input flange 6, hypoid gear 10, etc. manufacturing tolerances and installation tolerances, etc.
It is determined for each product by the accumulation of various dimensional uncertainties, and it is not possible to specify unique design dimensions for all products. Therefore, the dimensions and types of the distance pieces 15 and shims 16 to be laminated on the span S are determined for the first time during the assembly work. Therefore, as described above, preload adjustment, which is affected by the uncertainty of the dimension of the span S and the arrangement of the shims 16, etc., has been an extremely difficult task that is mostly based on experience.

In fact, when adjusting the preload along with the assembly work of the drive pinion shaft 1, distance pieces 15 and shims 16 are appropriately arranged on the span S as described above, and after the whole is assembled, the prescribed tightening is performed. The nut 8 will be tightened with torque and the bearing pressure will be measured. At this time, if the bearing pressure is not at the set value, the nut 8 is removed, the drive/pinion shaft 1 is removed, one bearing member 14 is separated using a press and disassembled, and a new shim 16 is installed based on the measured value. The preload is adjusted by replacing the bearing with the distance piece 15 and assembling the whole thing again, and measuring the bearing pressure in the same manner. Conventionally, in order to manufacture an integrated final gear, the same operation had to be repeated over and over again until the specified bearing pressure was obtained with the specified tightening torque. I couldn't work quickly. Further, this work necessarily requires experienced and skilled workers in order to shorten the required time as much as possible, and there have been problems such as the inability of unskilled workers to assemble it easily.

[Purpose of the invention]

The present invention has been devised in view of the above problems and to effectively solve them.

An object of the present invention is to easily and accurately adjust preload for applying a predetermined bearing pressure to a bearing member provided to rotatably support the input side of a drive pinion shaft from its outer circumferential side. To provide a straddle mounting structure for a drive pinion shaft, which can significantly shorten the time required for pinion shaft assembly work and improve work efficiency.

[Embodiments of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a straddle mounting structure for a drive pinion shaft according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Fig. 2, reference numeral 1 denotes a drive pinion shaft that is provided inside and outside of a differential case 3 in which a differential gear is incorporated, and is used to transmit the rotational driving force of a propeller shaft, etc. to the differential gear. and
This drive pinion shaft 1 is an annular pinion shaft that partitions and closes the differential case 3.
It is rotatably attached to the inside of the cage 4. This drive pinion shaft 1 has a ring gear 11 connected to a differential gear at its output rotating part 9 located inside the differential case 3.
A hypoid gear 10 that meshes with the hypoid gear 10 is formed integrally with the hypoid gear 10, and is formed at different levels from the shoulder portion 10a of the hypoid gear 10, and extends outward from the differential case 3 via the pinion cage 4. Extending end 5a of shaft-like input rotating part 5
An input flange 6, which is a joint member that is connected to a propeller shaft or the like, is provided at the bottom. This input flange 6 is connected to the drive pinion shaft 1
It is fitted onto the extending end 5a of the propeller shaft through a spline formed along its axial direction, and is engaged therewith with an engaging seat portion 6b recessed at a different level from the connecting portion 6c with the propeller shaft, etc. The mating washer 7 applies a predetermined axial force to the nut 8, which is screwed onto the extending end 5a protruding from the engagement seat 6b.

Drive pinion shaft 1 configured in this way
, the shaft portion 9a protruding from the output rotating portion 9 along the axial direction is connected to the differential case 3.
The input rotating part 5, which is supported by a bearing member 12 provided inside and located between the output rotating part 9 and the extending end 5a, is inserted into the pinion cage 4 from the outer circumferential side that is radially outward. It is supported by two press-fitted ring-shaped bearing members 13 and 14, and is straddle mounted. In particular, the two bearing members 13 and 14 that support the input rotating part 5 of the drive pinion shaft 1 are press-fitted inside the pinion cage 4 from opposite directions, and are arranged at different levels inside the pinion cage 4. A predetermined span S is engaged with the expanded and circumferential brim-shaped engaging portion 4a to support the input rotating portion 5 at a predetermined distance.
It is separated by In addition, these bearing members 13 and 14 disperse the shaft load L applied along the axial direction of the drive pinion shaft 1 radially outward and act as a preload P, thereby reducing the bearing pressure on the bearing surfaces 18... In order to achieve this, it is provided with tapered rollers 17 and bearing surfaces 18 that are inclined with respect to the axial direction of the drive pinion shaft 1.

The above configuration is substantially the same as the conventional one.

By the way, the feature of the present invention is that the input flange 6 is fixed to the drive pinion shaft 1 by the distance piece and shim arranged in the span S of the bearing members 13 and 14 in order to adjust the preload. Instead of applying a part of the tightening force of the nut 8 to the bearing members 13 and 14, these shims, etc. are eliminated, and a part of the tightening force of the nut 8 is applied to the outside of the pinion cage 4. The preload member that is movably engaged along the axial direction of the exposed drive pinion shaft 1 is configured to independently apply the axial load L to the bearing members 13 and 14 to apply the preload P. . To explain in more detail, as shown in Figure 2,
The drive pinion shaft 1 has its output rotating section 9.
A stepped portion 20 is formed in the input rotating portion 5 between the extending end 5a and the extending end 5a, the diameter of which is appropriately reduced. A male thread is threaded on the large diameter side of this stepped portion 20, and the bearing member 14 (hereinafter referred to as the "outer bearing member") adjacent to this from the base end 6a side of the input flange 6.
A predetermined distance is formed across the sides. This male screw has a ring member which is a preload member that is movable along the axial direction of the drive pinion shaft 1 in order to engage the roller retainer 19 of the outer bearing member 14 and apply the axial load L by its movement. 21 are screwed together. Further, the roller retainer 19 of the bearing member 13 on the opposite side of the outer bearing member 14 (hereinafter referred to as the "inner bearing member") is engaged with the shoulder portion 10a of the hypoid gear 10. These bearing members 13 and 14 are connected to the pinion from the ring member 21.
Shoulder 1 of hypoid gear 10 via cage 4
It is configured to be engaged in series between 0a and 0a.

The proximal end 6a of the input flange 6 is engaged with the engaging portion 22, which is the end face of the stepped portion 20.
Therefore, the input flange 6 is connected to the washer 7.
It is sandwiched between the nut 8 and the engaging portion 22.

The operation of the above configuration will be described.

As shown in Figure 2, drive pinion shaft 1
When assembling the pinion, first remove it from the differential case 3.
Bearing members 13 and 14 are press-fitted into the cage 4 from opposite directions to form a bearing body. At this time, the bearing members 13 and 14 are separated by a predetermined span S, and the engaging portion 4a of the pinion cage 4 is
will be engaged with. Next, the drive pinion shaft 1 is press-fitted from the inner bearing member 13 side with its input rotating part 5 first, and these bearing members 13,
14 to support it. In this way, the stepped portion 20
The male screw section is exposed to the outside of the pinion cage 4 from the outer bearing member 14 side. Also, at this time, the roller retainer 1 of the inner bearing member 13
9 is engaged with the shoulder portion 10a of the hypoid gear 10. Next, a ring member 21 serving as a preload member is screwed onto the male thread of the stepped portion 20 on the input rotating portion 5 of the drive pinion shaft 1 protruding from the pinion cage 4, and this is gradually tightened. Accordingly, an axial load L along the axial direction of the drive pinion shaft 1 acts as a preload P on the roller retainer 19 of the outer bearing member 14 that is engaged with the ring member 21 . This preload P
Since the span S of the bearing members 13 and 14 is open, all of the transmission is transmitted to the pinion cage 4 via the inclined bearing surface 18, and is further transmitted to the hypoid gear 10 via the inner bearing member 13. This will be transmitted to the shoulder portion 10a. These bearing members 13 and 14 can obtain a predetermined bearing pressure on their bearing surfaces 18 by applying the preload P to the hypoid gear 10 to the pinion cage 4 as a reaction force. That is, in the present invention, the shims and distance pieces conventionally laminated in the narrow span S between the bearing members 13 and 14 for use in preload adjustment are eliminated, and the fastening force T of the nut 8 is reduced. By cutting off the correlation with the pinion
Since the preload P can be applied to the bearing members 13 and 14 only by the single tightening force of the ring member 21 exposed on the outside of the cage 4, the preload adjustment work is as simple as tightening and loosening the ring member 21. The final gear can be assembled in a single assembly operation without any disassembly work required to remove the already assembled bearing members 13, 14, etc. as in the past. In addition, in the present invention, when applying the preload P, the ring member 21 is applied continuously with the external thread of the stepped portion 20 of the drive pinion shaft 1, instead of applying the preload P in a step-like manner based on the dimensions of a shim or the like as in the past. Since the preload P can be continuously changed by moving it to the position, the preload P can be adjusted easily and accurately regardless of whether the user is an expert or an unskilled person.

Once the preload has been adjusted, the input flange 6 is then fitted onto the drive pinion shaft 1 from the extending end 5a via the spline, its base end 6a is engaged with the engaging portion 22, and the nut is tightened. 8 with a predetermined tightening torque. The input flange 6 is now fastened with the tightening force T of the nut 8.

The male thread of the stepped portion 20 of the drive pinion shaft 1 and the ring member 21 are self-locked by the friction of their threaded surfaces, or adhesive is applied to these threaded surfaces so that they will not loosen after tightening. do not have.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that the present invention can be modified and implemented in various ways without changing the gist.

〔Effect of the invention〕

In summary, the present invention exhibits the following excellent effects.

The input side of the drive pinion shaft is equipped with a joint member that is fastened by applying a predetermined axial force with a nut, and a pinion cage is installed around the input side of the drive pinion shaft to hold the span of the bearing member in order to restrict it only in the outward radial direction. Then, a stepped portion with a male screw threaded on the large diameter side circumferential surface of the drive pinion shaft is formed, and the coupling member is engaged with the end surface of the stepped portion, and is screwed into the male screw and appropriately pressed against the bearing member. Since the preload member is provided, the preload can be adjusted by simply tightening or loosening the preload member on the input side of the bearing member, and the assembly work can be performed easily and quickly.

[Brief explanation of drawings]

FIG. 1 is a sectional plan view showing a conventional straddle mounting structure for a drive pinion shaft, and FIG. 2 is a sectional plan view showing a preferred embodiment of the straddle mounting structure for a drive pinion shaft according to the present invention. It is. In the figure, 1 is a drive pinion shaft, 4 is a pinion cage, 6 is an input flange which is a coupling member, 8 is a nut, 11 is a ring gear, 13,
14 is a bearing member, 20 is a stepped portion, 21 is a ring member which is a preload member, and 22 is an engaging portion which is an end face of the stepped portion.

Claims (1)

[Claims] 1. A drive pinion shaft whose output side is meshed with a ring gear, a pair of bearing members arranged in parallel in the axial direction and having bearing surfaces inclined with respect to the drive pinion shaft, and the drive pinion shaft. A pinion cage is provided with a joint member which is fastened by applying a predetermined axial force by a nut to the input side of the pinion cage, and the pinion cage is press-fitted from opposite directions to hold the bearing member in order to restrict the span of the bearing member only from the outside in the radial direction. is provided around the drive/pinion shaft, and a stepped portion is formed in which the diameter is reduced at a position extending toward the input side beyond the bearing member and a male screw is threaded on the larger diameter side circumferential surface, and the end portion of the coupling member is A drive characterized in that a preload member is provided for applying an axial load to the bearing member side by engaging with the end face of the stepped portion and screwing into the male screw and appropriately pressing against the bearing member.・Pinion shaft straddle mounting structure.