JPH0666351A - Backlash shim selecting method for differential device - Google Patents

Abstract

PURPOSE:To set the backlash adjusting shim thicknesses to the optimum sizes for each work by calculating them based on the sizes between a drive pinion engaging tooth flank and a differential carrier shim fitting face, between the right and left shim fitting faces, between a ring gear engaging tooth flank and a side bearing end face, between both side bearing end faces. CONSTITUTION:A size L1 from the engaging tooth flank of a pinion 14 to one shim fitting face 10a of a differential carrier 10 and a size L2 between the right and left shim fitting faces 10a, 11a are measured while the drive pinion 14 is assembled into the differential carrier 10. A size L3 from the engaging tooth flank of a gear 24 to the end face of one bearing 27 and a size L4 between end faces of bearings 26, 27 are measured while the ring gear 24 and side bearings 26, 27 are assembled into a differential case 20. Thicknesses of backlash adjusting shims 28, 29 are calculated based on the sizes L1-L4. The size change caused by a load at the time of assembling is taken into consideration, and the shim thicknesses can be accurately determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selecting a shim having an appropriate thickness for adjusting backlash between a drive pinion and a ring gear of a differential gear.

[0002]

2. Description of the Related Art Conventionally, as a method of selecting this type of backlash, for example, a technique disclosed in Japanese Patent Laid-Open No. 63-180767 can be mentioned. In this publication, first, the size of a portion of each component of the differential device that affects the thickness of the shim is measured as a single product. On the other hand, the dimensions in the actual assembling state, which are determined by the load applied to the press-fitted parts and the setting of the preload at the time of assembling each component, are predicted by the press-fitting margin. Then, based on this prediction, the thickness of the shim is obtained by correcting the measurement size.

[0003]

However, the dimensions in the state in which the respective components are assembled have some variations depending on the work (differential device), and it is difficult to predict the correction dimensions in anticipation thereof. Is. As a result, the thickness of the shim cannot be set accurately, and therefore backlash adjustment between the drive pinion and the ring gear also varies. Further, as described above, since the dimensions of each component are individually measured, the number of man-hours for the measurement work is large and the work is likely to be complicated.

The technical problem of the present invention is to calculate the thickness of the shim for adjusting the backlash based on each dimension measured by incorporating the variation of the dimension associated with the preload set at the time of assembling the differential device. The thickness of this shim should be optimized for each work, and the number of man-hours for measurement work should be reduced.

[0005]

In order to solve the above-mentioned problems, in the backlash shim selecting method for a differential device according to the present invention, a drive pinion and a differential case having a ring gear which is always meshed with the drive pinion are incorporated in a differential carrier. In addition, the differential device is provided with shims for adjusting the backlash between the drive pinion and the ring gear between the end surfaces of the left and right side bearings that rotatably support the differential case and the left and right shim mounting surfaces of the differential carrier. , With the drive pinion assembled to the differential carrier, a dimension L1 from the meshing tooth surface of the drive pinion to one shim mounting surface of the differential carrier, and a dimension L2 between the left and right shim mounting surfaces. While measuring each, With the ring gear and both side bearings assembled to the bearing, measure the dimension L3 from the meshing tooth surface of this ring gear to the end surface of one side bearing, and the dimension L4 between the end surfaces of both side bearings. The thickness of the shim for adjusting the backlash is calculated based on the dimensions L1 to L4.

[0006]

According to the backlash shim selection method of the present invention,
Since each of the above dimensions L1 to L4 is measured with the drive pinion attached to the differential carrier and with the ring gear and both side bearings attached to the differential case, each of these dimensions L1 to L4 is a differential device. The dimensional change due to the press-fitting load and preload during assembly is taken into consideration. Therefore, uncertain factors such as predicting such dimensional changes are eliminated, the thickness of the shim can be accurately obtained based on the measurement dimensions L1 to L4, and the number of measurement items is small, so the number of man-hours required Is also reduced.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. The differential device is shown in cross section in FIG. As can be seen in this drawing, the differential carrier 1
Drive pinion shaft 1 installed inside 0
2 is rotatably supported by a front bearing 18 and a rear bearing 19 using tapered roller bearings. A drive pinion 14 meshed with a ring gear 24 of a differential case 20 described below is integrally formed at an end portion of the drive pinion shaft 12 located inside the differential carrier 10, and the other end portion thereof is integrally formed. Is connected to a companion flange 16 that receives a driving force from the engine through a propeller shaft (not shown) and the like so that rotation can be transmitted. By tightening the companion flange 16 and the drive pinion shaft 12 with the lock nut 15, the preload for the front bearing 18 and the rear bearing 19 is set based on the thrust loads in the opposite directions applied between them. Is well known.

The differential case 20 incorporated in the differential carrier 10 is adapted to rotate about an axis perpendicular to the axis of the drive pinion shaft 12. That is, the sleeve portions formed on the left and right sides of the rotation axis of the differential case 20 are side bearings 26, 2 using tapered roller bearings.
It is rotatably supported by the differential carrier 10 by 7. Further, the ring gear 24 is integrally assembled with the differential case 20 on the outer periphery of the differential case 20. Then, the drive pinion shaft 12 is passed through the companion flange 16 by the driving force of the engine.
When the drive rotates, the drive pinion 14 and the ring gear 24
The differential case 20 rotates around its rotation axis by meshing with the. A hypoid gear is used as both the drive pinion 14 and the ring gear 24.

The differential carrier 10 is a differential case 20.
The carrier cover 11 is separated from the main body with respect to the direction along the rotation axis. Therefore, of the both side bearings 26 and 27, the outer race of the side bearing 27 located on the right side of FIG.
Although the outer race of the left side bearing 26 is attached to the carrier cover 11, the outer race is attached to the carrier cover 11. The outer race end faces of both side bearings 26 and 27 and the differential carrier 1 facing these end faces.
0 and the respective shim mounting surfaces 1 of the carrier cover 11
The shims 28 and 2 for adjusting the backlash between the drive pinion 14 and the ring gear 24 are provided between 0a and 11a.
9 are provided respectively.

FIG. 1 shows a shim 2 for adjusting the backlash.
An overview of the system for determining the proper thickness of 8,29 is shown. As is apparent from FIG. 1, the measuring system is divided into a differential carrier sub-assembly measuring section A, a differential case sub-assembly measuring section B, and a carrier cover measuring section C. In the diff carrier sub-assembly to be measured by the measuring section A, the drive pinion shaft 12 is rotatable by the front bearing 18 and the rear bearing 19 with respect to the diff carrier 10 (only the main body from which the diff case 20 is removed). It is assembled while being supported by. Further, the companion flange 16 is coupled to the drive pinion shaft 12, and a predetermined preload is added to both bearings 18 and 19 by tightening the lock nut 15 as described above. On the other hand, in the differential case sub-assembly that is the object of measurement in the measuring section B, the ring gear 24 is mounted on the outer periphery of the differential case 20, and the inner races of the side bearings 26 and 27 are attached to the left and right sleeve portions. Each is press-fitted.

Next, the procedure for determining the proper thickness of the shims 28, 29 will be described. First, in the diff carrier sub-assembly measuring section A, the mating surface of the diff carrier 10 with the carrier cover 11 is temporarily placed on the measurement reference surface 30 and the mating surface of the diff carrier 10 is applied by the operating force of the cylinder 33 by the clamp unit 32. Is pressed against the measurement reference surface 30. At the same time, the drive unit 34 including the motor 36 and the angle detector 37 is advanced toward the companion flange 16, and the companion flange 1 is clamped by the drive unit 34.
Chuck 6 In this state, the motor 36 of the drive unit 34 is driven to drive the companion flange 1
The drive pinion shaft 12 is rotated via 6. At this time, the approximate position of the tooth in the rotational direction of the drive pinion 14 is detected by the index position sensor 38 provided on the side of the measurement reference surface 30. The drive of the motor 36 is stopped by this detection signal,
The tip of the touch sensor 40 is inserted into one tooth groove of the drive pinion 14, which is a hypoid gear. Here, the motor 36 is first rotated in the normal direction, and the angle θ1L (radian) detected by the angle detector 37 when the tip of the touch sensor 40 hits one side surface of the tooth groove is read by the arithmetic unit 70. Next, the motor 36 is rotated in the reverse direction, and the angle θ1R detected by the angle detector 37 when the tip of the touch sensor 40 hits the other side surface of the tooth space is read by the arithmetic unit 70.
After the detection angle is read for one tooth groove in this manner, the touch sensor 40 is once retracted, and thereafter, the drive pinion 14 is rotated in the same manner as described above.
0 is sequentially inserted into another tooth groove and the detected angle θi
The arithmetic unit 70 reads L and θiR.

FIG. 2 shows a conceptual diagram for angle detection by the touch sensor 40. As is clear from this drawing, in each tooth groove of the drive pinion 14, the angle between the tooth flanks at the measurement position by the touch sensor 40 is | θiL-
It is represented by θiR |. Further, the dimension (radius) from the rotation center of the drive pinion 14 to the measurement position is r, and the number of teeth of the drive pinion 14 is n. Here, the dimension L1 (see FIG. 1) from the proper meshing tooth surface of the drive pinion 14 to the ring gear 24 to the shim mounting surface 10a of the differential carrier 10 is calculated by the following mathematical formula 1.

[0013]

[Equation 1] However, in this formula 1, a is a tooth width change coefficient, S is a tooth width aiming value, and La is a shim mounting surface 1 of the differential carrier 10.
It is a dimension from 0a to the measurement reference position. In this way, the dimension L1 shown in FIG. 1 is calculated by the arithmetic unit 70, and from the mating surface (measurement reference surface 30) of the differential carrier 10 measured by the position sensor 42 to the shim mounting surface 10a. The calculation device 70 reads the dimension L2a.

The differential case sub-assembly measuring section B is provided with a reference block 50 as shown in FIG. 1, and temporary receiving members 51 are arranged at a plurality of positions (three positions) in the circumferential direction with respect to the upper surface thereof. Further, each of the temporary receiving members 51 has the tip end portion of the ring gear 24 of the differential case sub-assembly.
It has a ball with a proper diameter that fits in the tooth space of the. The ring gear 24 is set to these temporary receiving members 51, and the outer race end faces of the both side bearings 26 and 27 are clamped by the upper and lower clamp units 52 and 53. At the same time, a part of each clamp unit 52, 53 is inserted into the inner circumference of the sleeve portion of the differential case 20, thereby centering the differential case 20 and adding a preload equivalent to the actual vehicle to both side bearings 26, 27. In this state, the tracing stylus 56a of the displacement sensor 56 provided in the lower clamp unit 53 is inserted into the tooth groove of the ring gear 24, which is a hypoid gear, from the meshing tooth surface of the ring gear 24 measured by the sensor 56. Dimension L3 to the end surface of one side bearing 27
Is read by the arithmetic unit 70. In parallel with this, both side bearings 26, 2 measured by the position sensor 58
The dimension L4 between 7 is also read by the arithmetic unit 70.

The displacement sensor 56 is the ring gear 2
The measurement dimension L3 is averaged by arranging the measurement dimensions L3 at a plurality of positions (three positions) in the circumferential direction in consideration of the influence of the tooth runout. Further, since the preload on both side bearings 26 and 27 is relatively small, the measuring element 56 of the displacement sensor 56 is
The spring a has proper contact with the tooth surface of the ring gear 24 due to its own spring force, and the indexing of the differential case sub-assembly in the rotational direction is unnecessary.

In the carrier cover measuring section C,
As shown in FIG. 1, the mating surface of the carrier cover 11 with the differential carrier 10 is temporarily placed on the measurement reference surface 60, and this mating surface is pressed against the measurement reference surface 60 by the clamp unit 62. In this state, the arithmetic unit 70 reads the dimension L2b from the mating surface (measurement reference surface 60) of the carrier cover 11 measured by the position sensor 64 to the shim mounting surface 11a. This dimension L
2b and the dimension L2a measured by the differential carrier sub-assembly measuring section A (L2a + L2b), the dimension L2 between the shim mounting surfaces 10a and 11a in the state where the differential carrier 10 and the carrier cover 11 are joined. Is obtained. Therefore, the shims 28, 29 are processed by the processing of the arithmetic unit 70 based on the respective dimensions L1 to L4.
The respective thicknesses T1 and T2 of the above are calculated by the following mathematical expressions 2 and 3, respectively.

Formula 2 T1 = L1-L3 + α1 Formula 3 T2 = L2- (L4 + T1) + α2 where α1 and α2 are correction values. Thus, the optimum thickness of the shims 28 and 29 for adjusting the backlash between the drive pinion 14 and the ring gear 24 can be easily obtained.

[0018]

As described above, according to the present invention, each dimension for calculating the thickness of the backlash adjusting shim is measured in a state in which the variation of the dimension due to the press-fitting load and the preload at the time of assembling the differential device is incorporated. As a result, the calculated thickness of the shim becomes highly accurate, and the number of man-hours for measurement work is reduced.

[Brief description of drawings]

FIG. 1 is a system diagram for obtaining a backlash adjustment shim thickness.

FIG. 2 is a conceptual diagram for detecting an angle between tooth flanks of a drive pinion.

FIG. 3 is a cross-sectional view of a differential device.

[Explanation of symbols]

 10 differential carrier 10a shim mounting surface 11a shim mounting surface 14 drive pinion 20 differential case 24 ring gear 26 side bearing 27 side bearing 28 backlash adjustment shim 29 backlash adjustment shim

Claims (1)

[Claims] 1. A drive pinion and a differential case having a ring gear that is always meshed with the drive pinion are assembled together in a differential carrier, and the respective end surfaces of the left and right side bearings that rotatably support the differential case and the left and right sides of the differential carrier. Targeting a differential device in which a shim for adjusting the backlash between the drive pinion and the ring gear is provided between the drive pinion and the shim mounting surface, with the drive pinion assembled to the differential carrier, the meshing tooth surface of the drive pinion To the one shim mounting surface of the differential carrier and the dimension L2 between the left and right shim mounting surfaces are measured, respectively, while the ring gear and both side bearings are attached to the differential case. One side bearing from meshing tooth surface The backlash of the differential device is characterized in that the dimension L3 up to the end face and the dimension L4 between the end faces of both side bearings are respectively measured, and the thickness of the shims for adjusting the backlash is calculated based on the dimensions L1 to L4. Shim selection method.