JPS6018617A - Selection method of preload shim thickness in tapered roller bearing and device thereof - Google Patents

Abstract

PURPOSE:To keep off defective preloading, by rotating a differential gear as preloading a tapered roller bearing, while measuring the depth of a shim insertion in an almost actual shimming state and thereby making a selection of proper shim thickness. CONSTITUTION:In a state that one side shim 14b is inset in advance, a hydraulic motor 23 is driven, rotating a differential gear 3, and the turning moment at that time is detected with a torque meter 24. Then, a press-in unit 25 is made to advance forward, and when an outer race 13 of one side tapered roller bearing 10a is pushed in deep with a presser 26, the preload imposed on each of tapered roller bearings 10a and 10b, namely, the turning moment is growing larger by degrees and at that point that this value accords with the proper value, the presser 26 is stopped. Afterward, thrusting depth t1 of the presser 26 is measured by a size measuring instrument 27 and then the insetting depth of a shim 14a or t=t1-t2 is found on the basis of said thrusting depth t1 and height t2 of a boss part 15a of a retainer 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for selecting an appropriate thickness of a shim for adjusting preload of a tapered roller bearing.

(Prior Art) Conventionally, in order to select the thickness of a shim for adjusting the preload of a tapered roller bearing (hereinafter referred to as a bearing), the dimensions of each individual component to which the bearing is assembled are measured in advance, Appropriate correction coefficients and correction constants were added to this to obtain an appropriate value.

However, in the above conventional method, ■ if the rigidity of the case that holds the bearing is small and its rigidity is large; ■ if the fitting tolerance between the inner race and outer race of the bearing and the mating part is large, and the bearing line width during press-fitting is When the preload changes, the preload after assembly has a large variation with respect to the target value, and this variation often results in a preload failure.

If the preload is defective, disassemble the product and
The shims had to be replaced and reassembled, which increased the number of man-hours, increased assembly costs, and reduced productivity, posing a major problem.

(Purpose) In view of the problems of the prior art described above, the present invention provides a preload shim for a tapered roller bearing in which the shim thickness is selected in a state close to the actual shim assembly, thereby preventing preload defects. The object of the present invention is to provide a thickness selection method and device.

(Structure of the Invention) This purpose is to rotate the differential gear while adding a tapered roller pair link nifle load, and when the preload reaches an appropriate value, stop and maintain the addition of the preload, This is achieved by a shim thickness selection method and apparatus that subsequently measures the shim assembly depth to obtain an appropriate shim thickness.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

Examples of products to which tapered roller bearings and their preload adjustment shims are assembled include transaxles in front-wheel drive automobiles. Fig. 1 shows its appearance, and the product 5, which is made up of a transmissicon case 1 and a transaxle case 2, has a differential gear built into its lower part as shown by arrow A. A tapered roller bearing and a shim are interposed in the gear mounting portion.

FIG. 2 shows the details of the internal structure of the portion shown by arrow A. In FIG. 2, reference numeral 5 denotes a differential gear rotatably supported by a transmission case 1 and a transaxle case 2; a ring gear 5 fixed to the outer circumference of the differential case 4; and a pair of side gears 6a installed inside the differential case 4 in the left-right direction.

6b, and a pinion gear 7 that is installed vertically inside the differential case 4 and meshes with each of the side gears 6a and 6b.
It consists of a pinion shaft 8 having shafts a and 7b.

Such a differential gear s is commonly seen in the past, and axle shafts 9a and 9b extending in the left-right direction are attached to each of the side gears 6a and 6b, and axle shafts 9a and 9b are attached to the side gears 6a and 6b, respectively. The driving force transmitted to the differential case 4 is transmitted to the pinion.

Specifically, tapered roller bearings 10a and 10b are interposed in the support portion of the differential gear 3. The tapered roller bearings 10a, 10b consist of a taper/l' roller 11, an inner race 12, and an outer race 16, and shims 14a, 14b that directly contact the end surface of the outer race 16) are bolted to the transmission case 1. It is assembled in a press-fit state with the fastened retainer 15. That is, a preload is applied to the case (troller bearings 10a, 10b), and the reaction force is applied to the transmission case 1 via the retainer 15. Note that there are also products that do not use the retainer 15. , in this case, the reaction force is applied directly to the transmission case 1.

and \, the above preload is determined by the thickness of the shims 14fi and 14b, and in the present invention, the preload is determined by the thickness of the shims 14fi and 14b.
The following means and methods were used to select the appropriate thickness of 4B+14b.

Figure 3 shows a product that uses retainer 15 (shown in Figure 2)
This figure shows a shim thickness selection method and an apparatus for the same. In FIG. 5, 21 is a main shaft rotation unit for rotationally driving the differential gear 3, and includes a collet chuck 22 that supports the differential case 4, a hydraulic motor 25 as a driving source, and a torque meter 24. On the other hand, the tapered roller bearing 10a.

A press-fitting unit 25 is provided for press-fitting the transmission case 10b into the transmission case 1 and the transaxle case 2. The press-fitting unit 25 includes a press-fitting element 26 that comes into contact with the outer race 13 and exerts a direct compression action, a shim 14a,
14b, a dummy retainer 28, and a reaction force receiving hook 2.
9, and a drive device (not shown) is provided. In addition, the main shaft rotation unit 21 and the press-fitting unit 25
is connected to a control device (not shown).

The thickness of one shim 14 is determined in advance by the shim thickness selection device.
In the assembled state, first, the main shaft rotating unit 21 is advanced, and the collet chuck 22 chucks the differential case 4. Subsequently, the hydraulic motor 23 is driven to rotate the differential gear 5, and the rotational torque at that time is detected by the torque meter 24 and stored in the control device.

Next, the press-fitting unit 25 is moved forward, and the press-fitting element 26 is inserted into the outer race 13 of one tapered roller bearing 10a.
Push in. At this time, in advance, transmission case 1
A reaction force is applied to the transmission case 1 through a dummy retainer 28 bolted to the transmission case 1 and a reaction force receiving hook 29 that engages with the dummy retainer 28 .

As the press-fitting element 26 continues to be pushed in this way, the tapered roller bearing 10a.

The preload applied to 10b and therefore the rotational torque gradually increase, but during this time the rotational torque is continuously detected by the torque meter 24, and when the rotational torque reaches a value that provides an appropriate preload, a signal is sent from the control device. After being sent out, the pushing operation of the press-fit element 26 stops.

After that, the depth of the press-fit element 26 from the end surface of the transmission case 1 is measured using the dimension measuring device 27. Regarding the retainer 15, as shown in Fig. 4,
Separately, the height t2 of the boss portion 15a is measured and the value is stored in the control device. Based on the relational expression 1=11-1. to the other shim 1
Calculate the assembly depth t of 4a. Therefore, by selecting a shim 14B having a thickness equal to the installation depth t of the other shim 14g and assembling it as shown in FIG. 2, the tapered roller bearings 10a and 10b are , the preload set above will be applied.

On the other hand, for products that do not use retainers, first use the same method as described above for the seated roller bearings 10a, 1 (
! As shown in FIG. 5, in which the same components as in FIG. ．． is directly measured with the dimension measuring device 27. In this case, the gap to corresponds to the assembly depth t of the other shim 14a, and a shim 14a having a thickness corresponding to this may be selected.

It should be noted that the illegality is not limited to use in automobiles, but can of course be applied to other devices including tapered roller bearings and shims.

(Effects of the Invention) As explained above in detail, the present invention rotates the differential gear while applying a preload to the tapered roller bearing, and when the preload reaches an appropriate value, stops applying the preload. The shim assembly depth is measured by holding the shim in place, and the shim thickness corresponding to this value is selected. This makes it possible to suppress variations in the preload applied to the tapered roller bearing as much as possible, and prevents the trouble of reassembling due to poor preload.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a product to which the present invention is applied;
Fig. 2 is a sectional view showing the details of the internal structure of Fig. 1 in the direction of arrow A; Fig. 3 is a sectional view showing an example of a preload shim thickness selection device for a chill path roller bearing and its usage; FIG. 4 is a sectional view showing the shape of the retainer, and FIG. 5 is a sectional view showing another example of how the device for selecting the preload shim thickness of a tapered roller bearing is used. 1°°゛Transmission case, 2.°Transaxle case, 5...Differential gear, 10
a, 10b...Tapered roller bearing, 15...
・Outer lace, j4a, 14b... Shim, 21・
...Spindle rotation unit, 24...Torque meter, 25...
・Press-fitting unit, 27... Dimension measuring device, t... Assembly depth. Sai 1 Figure Hachiryo 2 Figure

Claims (3)

[Claims] (1) Rotate the differential gear while applying a preload to the tapered roller bearing, and when the preload reaches an appropriate value, stop and maintain the application of the preload, and then measure the shim assembly depth to determine the appropriate value. A method for selecting a preload shim thickness for a tapered roller bearing, which is characterized by obtaining a shim thickness. (2) Claim 1, characterized in that the preload is adjusted by detecting the rotational torque of the differential gear.
How to select preload shim thickness for tapered roller bearings as described in section. (3) A main shaft rotation unit that rotationally drives the differential gear, a torque meter built into the main shaft rotation unit, a press-fit unit that pushes in the outer race of the tapered roller bearing and applies a reaction force to the bearing holding case, and the press-fit unit A preload shim thickness selection device for a tapered roller bearing, which is built in and equipped with a dimension measuring device for measuring the shim assembly depth.