JP2001004308A - Method for measuring internal gap of double row conical roller bearing unit for supporting wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and correctly confirm a pre-load amount of a bearing part constituted to include a plurality of conical rollers and tracks. SOLUTION: A work of pressing an inner ring 12 into a step part 13 is interrupted once before the inner ring 12 is completely pressed to a deep part of the step part 13. In this state, a range (size L) where an outer ring 1 can move in an axis direction is measured. Then, the work of pressing the inner ring 12 is resumed. One end face of the inner ring 12 is pressed in contact with a step face 17 of a hub body 11, whereby a bearing part is completed. At the same time, a press amount P of the inner ring 12 before the one end face of the inner ring 12 comes in pressed contact with the step face 17 after the work of pressing the inner ring 12 is resumed is measured. A pre-load amount applied to the bearing part is obtained on the basis of an axial gap L-P of the bearing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-row tapered roller bearing unit for supporting wheels of a relatively heavy vehicle such as a light truck or a large passenger car, which is rotatably supported by a suspension device. It is used to measure the internal clearance in the axial direction.

[0002]

2. Description of the Related Art Rolling bearing units for supporting wheels are used to rotatably support the wheels of an automobile with respect to a suspension system. FIGS. 3 and 4 show first and second examples of wheel supporting rolling bearing units conventionally used for such a purpose. The first and second examples of the wheel supporting rolling bearing unit include an outer ring 1, a hub 2, and a plurality of balls 3. Of these, the outer race 1 is provided with mounting portions 6 for fixing the first and second outer raceways 4 and 5 on the inner peripheral surface and the suspension device on the outer peripheral surface, respectively. The hub 2 is disposed concentrically with the outer ring 1 on the inner diameter side of the outer ring 1.

[0003] Such a hub 2 is used to support and fix wheels at one end of the outer peripheral surface (the end which is located on the outside in the width direction of the vehicle when assembled to the vehicle, the left end in Figs. 3 and 4). The first inner ring raceway 8 is also provided at the intermediate portion, and the flange 7 is provided at the other end portion (the end portion which is closer to the center in the width direction of the vehicle when assembled to the vehicle, the right end portion in FIGS. 3 and 4). Two inner raceways 9 are provided, respectively. Then, the first and second inner raceways 8, 9 and the first and second outer raceways 4, 5,
Between them, a plurality of balls 3, 3 are provided in such a manner as to be freely rolled by retainers 10, 10 made of synthetic resin, respectively.

[0004] The hub 2 comprises a hub body 11 and an inner ring 1.
2, and the second inner raceway 9 is formed on the outer peripheral surface of the inner race 12. In order to combine the hub body 11 and the inner ring 12 in this manner, a step portion 13 having a smaller diameter than the portion where the first inner ring track 8 is formed is formed on the outer peripheral surface of the other end portion of the hub body 11. Then, the inner ring 12 is externally fitted to the step portion 13 by tight fitting (press-fitting), and the other end surface of the inner ring 12 is fixed to the other end portion of the hub main body 11 by a caulking portion 14 as fixing means. By pressing down, the inner ring 12 is fixed to the hub body 11. With the other end surface of the inner ring 12 held down by the caulking portion 14 in this manner, a preload is applied to a bearing portion including the balls 3 and 3 and the raceways 4, 5, 8 and 9. Granted. That is, in the state shown in the drawing, the inner ring 12 is moved toward the base end side of the step portion 13 (the left end side in FIGS. 3 and 4) until the axial internal gap (axial internal gap) of the bearing section becomes negative. Has been pushed into. The other end of the inner ring 12 in the axial direction may be suppressed by a nut serving as a fixing means screwed to the other end of the hub body 7 in some cases.

In the example shown in the drawing, one end opening of the space in which the balls 3 are placed is sealed by a seal ring 15, and the other end opening of the outer ring 1 is closed by a cover 16. This prevents the lubricant such as grease sealed in the space where the balls 3 and 3 are installed from leaking to the outside, and also prevents foreign matters such as rainwater from entering the space. . When assembling the wheel supporting rolling bearing unit configured as described above to an automobile, the mounting portion 6 is connected and fixed to a knuckle or the like constituting a suspension device, and the wheel is supported and fixed to the flange 9. As a result, the wheels are rotatably supported by the suspension device.

[0006] In the case of the rolling bearing unit for wheel support constructed and operated as described above, the internal clearance of the bearing portion in the axial direction is, as in the structure shown in FIGS.
It is preferable to make it negative (apply a preload to the bearing portion). The reason for this is that the rigidity of the bearing portion is ensured, and the rolling surfaces of the balls 3, 3 and the raceways 4,
This is to prevent the occurrence of fretting at the contact portions with 5, 8, and 9. Further, the magnitude of the preload applied to the bearing portion needs to be regulated to an appropriate value so that the expected performance of the wheel supporting rolling bearing unit can be exhibited. That is, if the preload applied to the bearing portion is too small, the rigidity of the bearing portion is reduced, or fretting occurs at the contact portions, so that the life of the bearing portion is reduced. Is generated. On the other hand, if the preload applied to the bearing portion is too large, not only does vibration and unpleasant noise occur, but also the contact between the balls 3, 3 and the tracks 4, 5, 8, 9 is made. Since the surface pressure of the portion becomes excessive, there is a disadvantage that the life of the bearing portion is also reduced. Therefore, the preload applied to the bearing portion needs to be regulated to an appropriate value as described above.

Conventionally, in order to regulate the preload applied to the bearing portion to an appropriate value, conventionally, the operation of press-fitting the inner ring 12 into the step portion 13 and the caulking portion 14 or the nut are required The initial clearance of the bearing portion (the internal clearance at the time of non-use after the assembly is completed) is set in consideration of the decrease in the internal clearance of the bearing portion in the axial direction due to the operation of pressing the other end surface. Was. Specifically, the amount of caulking of the caulking portion 14 and the tightening force of the nut so that the preload of the bearing portion after assembly is at an appropriate value are checked by structural analysis and experiments. Then, the caulking operation of the caulking portion 14 and the tightening of the nut are performed until the amount of caulking and the tightening force reached in this way are reached, and the other end surface of the inner ring 12 is pressed, so that an appropriate amount of the bearing is applied to the bearing portion. Apply preload. In order to be able to apply such a preload, in the case of the structure shown in FIG.
A gap A is formed between one end surface of the inner ring 12 and a step surface 17 existing at the base end of the step portion 13.

On the other hand, in the case of the structure shown in FIG. 4, one end face of the inner ring 12 and the
The dimensions of each component are regulated such that an appropriate amount of preload is applied to the bearing portion in a state where these surfaces are in contact with each other. However, when the preload amount is regulated by such a method, a manufacturing error of each of the above-described constituent members directly leads to a difference in the preload amount. For this reason, after the assembly is completed, it is checked whether or not the proper amount of preload initially set is applied to the bearing portion. It is necessary to feed back to the production line and correct the production error. The preload amount of the bearing unit after the completion of such assembly can be confirmed based on the resonance frequency of the wheel supporting rolling bearing unit, which can be measured by, for example, exciting the wheel supporting rolling bearing unit. . That is, in this case, the relationship between the magnitude of the preload of the bearing portion and the resonance frequency is determined in advance by structural analysis, and the relationship between such a relationship and the resonance frequency actually measured as described above is determined. By comparing, it is confirmed whether or not the preload applied to the bearing portion is an appropriate value.

FIGS. 5 and 6 show a rolling bearing unit for supporting a wheel used for the above-mentioned purpose, which is used particularly in an application to be incorporated in a relatively heavy automobile such as a small truck or a large passenger car. 1 and 2 show first and second examples of a double-row tapered roller bearing unit for supporting wheels. In the case of such a double-row tapered roller bearing unit for supporting a wheel, each of the plurality of rolling elements constituting the bearing portion includes a tapered roller 1.
8, 18 are used. Accordingly, the first and second outer ring raceways 4 for guiding these tapered rollers 18, 18 are also provided.
a and 5a are formed in a conical concave shape, respectively, in a state where they are inclined in directions opposite to each other, and the first and second inner raceways 8a, 9a are also inclined in the directions opposite to each other so as to have a conical convex shape, respectively. It is formed in a state where it is set. Also, in the case of the structure shown in FIGS. 5 and 6, one end surface of the inner ring 12 and the step surface 17 are brought into contact with each other in a state after the assembly is completed. The dimensions of each component are regulated so that an appropriate amount of preload is applied to the bearing portion. Specifically, the distance W between the outer raceways 4a and 5a, the axial dimension X from the step surface 17 to the first inner raceway 8a, and the second inner race from one end surface of the inner race 12 By regulating the axial dimension Y up to the track 9a and the outer diameter dimension D of the tapered roller 18, etc.,
The above preload is regulated. In the case of the structure shown in FIG. 6, the inner end surface of the inner ring 12 is held down by a nut 21 which is screwed and tightened to a male screw portion 20 provided at the other end of the hub body 11.

In the illustrated example, each of the above tapered rollers 1
The other end opening of the space in which the spaces 8 and 18 are installed is closed by a seal ring 19 provided between the inner peripheral surface of the other end of the outer ring 1 and the outer peripheral surface of the inner ring 12 near the other end. In the case of the double row tapered roller bearing unit for wheel support configured as described above,
Since the tapered rollers 18 are used as the rolling elements, sufficient load capacity can be obtained, and sufficient durability can be ensured even when the rolling elements are incorporated in a heavy vehicle such as a small truck or a large passenger car. .

[0011]

Among the structures shown in FIGS. 3 to 6, in the case of the structure shown in FIG. 3, first, one end surface of the inner race 12 and the step surface 17 are formed after the assembly is completed. Is present, the inner ring 12 may generate a small vibration in the axial direction during operation, and a preload greater than necessary may be applied to the bearing portion. If the preload of the bearing portion becomes unnecessarily large in this way, it is not preferable because the inconvenience such as shortening of the life of the bearing portion occurs as described above. Therefore, the structure of the rolling bearing unit for supporting the wheel is such a structure as shown in FIGS. 4 to 6 that does not cause such inconvenience, that is, in a state after the assembly is completed, the one end face of the inner ring 12 and the It is preferable to adopt a structure in which the step surface 17 abuts.

However, among the structures shown in FIGS. 4 and 6, the structure shown in FIGS. 5 and 6 has the following problems in actual manufacturing. That is, in the case of the structure shown in FIG. 4, the preload amount of the bearing portion after the assembly is completed can be confirmed based on the measurement of the resonance frequency of the rolling bearing unit for supporting the wheel as described above. . However, such a method of measuring the amount of preload based on the resonance frequency of the wheel supporting rolling bearing unit is based on the case of a double row ball bearing unit as shown in FIG. However, it is not applicable to a double-row tapered roller bearing unit having a large spring stiffness and a small nonlinearity as shown in FIGS. Therefore, these FIGS.
It is desired to provide a means for accurately measuring the preload amount of the bearing portion constituting the double-row tapered roller bearing unit for wheel support as shown in FIG. The method for measuring the internal clearance of the double-row tapered roller bearing unit for wheel support according to the present invention has been invented in view of the above-described circumstances.

[0013]

SUMMARY OF THE INVENTION A double-row tapered roller bearing unit for supporting a wheel, in which an internal clearance in an axial direction is measured by a method for measuring an internal clearance of a wheel-supporting double-row tapered roller bearing unit of the present invention, comprises: Similar to the conventionally known double row tapered roller bearing unit for wheel support shown in FIGS. 5 and 6, the first and second outer rings each have a tapered concave shape on the inner peripheral surface and are inclined in opposite directions. The outer ring that forms the track, the hub that forms the first and second inner ring raceways, each of which has a conical convex shape and is inclined in opposite directions on the outer peripheral surface, and the first and second inner ring raceways and the first, And a plurality of tapered rollers provided so as to be able to freely roll between the second outer raceway and the second outer raceway, respectively. The hub includes a hub body having the first inner raceway formed on an outer peripheral surface thereof and an inner race having the second inner raceway formed on an outer peripheral surface thereof. At the end of the surface, a step portion having a smaller diameter than the portion where the first inner ring raceway is formed is formed, and the inner ring has one axial end face at the base end of this step portion at this step portion. The hub is supported and fixed to the hub body by externally fitting it in a state of being in contact with the step surface to be formed, and further pressing the other end surface in the axial direction by fixing means.

The method for measuring the internal clearance of a double-row tapered roller bearing unit for supporting a wheel according to the present invention includes the step of assembling the above-described double-row tapered roller bearing unit for supporting a wheel by connecting the inner ring to the stepped portion. When the outer ring is fitted to the distal end and the inner ring is pushed toward the base end of this step, first,
This pushing work is performed just before one end surface of the inner ring comes into contact with the step surface, and the rolling surfaces of a plurality of rolling elements arranged around the second inner ring raceway correspond to the second outer raceway. Stop shortly before contact. Next, in this state, by moving the outer ring in the axial direction, an axial dimension L in which the outer ring is movable in the axial direction is measured. Then
The pushing operation of the inner ring is resumed, and one end surface of the inner ring is brought into contact with the step surface. At the same time, the axial movement amount P of the inner ring from when the pushing operation is restarted until one end surface of the inner ring comes into contact with the step surface is measured. Thereby, the size of the internal gap in the axial direction of the bearing portion is obtained as LP.

[0015]

According to the method for measuring the internal clearance of the double-row tapered roller bearing unit for wheel support of the present invention as described above, the axial direction of the bearing portion constituting the double-row tapered roller bearing unit for wheel support extends. The internal clearance can be easily and accurately measured at the stage of assembling the double-row tapered roller bearing unit for wheel support. Therefore, it is possible to confirm whether or not an appropriate amount of preload has been applied to the bearing portion in a state where the double-row tapered roller bearing unit for wheel support is completed. Further, in the case of the present invention, such confirmation of the preload amount can be performed as a 100% inspection in the bearing unit assembly line. For this reason, a reliable product of good quality can be provided.

[0016]

1 and 2 show an embodiment of the present invention. The structure of the double-row tapered roller bearing unit for supporting wheels used in the description of the present embodiment is, in particular, in a state after completion, a step between one end face of the inner ring 12 (the left end face in FIGS. 1 and 2) and the hub body 11. At the point where the surface 17 abuts, and at the state where these two surfaces abut, a plurality of tapered rollers 1
5 and FIG. 5 including the point in which a preload is applied to the bearing portion including the respective tracks 4a, 5a, 8a and 9a.
This is the same as the wheel supporting double row tapered roller bearing unit shown in FIG. Therefore, the description of the structure of the double-row tapered roller bearing unit for supporting wheels is omitted or simplified, and the following description will focus on a method of measuring the internal clearance in the axial direction, which is a feature of the present invention. .

The measurement of the internal clearance of the bearing according to the present invention
It is performed by devising a method of assembling the double row tapered roller bearing unit for supporting the wheel. That is, to assemble the double-row tapered roller bearing unit for supporting the wheel, first, the outer ring 1 is arranged around the hub body 11 and the first inner ring raceway 8a formed on the outer peripheral surface of the intermediate portion of the hub body 11 is formed. A plurality of tapered rollers 18 are installed between the outer race 1 and the first outer raceway 4a formed at a portion near one end of the inner peripheral surface of the outer race 1 in a state where the plurality of tapered rollers 18 are rotatably held by the retainer 10. At the same time, the inner peripheral surface at one end of the outer ring 1 and the hub body 11
The seal ring 15 is
Attach.

Next, the other end of the hub body 11 (FIGS. 1-2)
(The right end of the outer ring 1), the inner ring 12 is externally fitted to the small-diameter stepped portion 13 so that the second inner ring raceway 9a formed on the outer peripheral surface of the inner ring 12 and the inner peripheral surface of the outer ring 1 near the other end thereof A plurality of tapered rollers 1 between the formed second outer raceway 5a;
8 and 18 are arranged in a state of being held by the retainer 10 so as to freely roll. For this reason, in the case of this example, first, the inner ring 12 is connected to the tip of the step 13 (the right end in FIGS. 1 and 2).
Then, it is externally fitted (press-fitted) by interference fit. Prior to the outer fitting work of the inner race 12, the second inner raceway 9a is required.
The plurality of tapered rollers 18, 18 are arranged in a state where the tapered rollers 18 are held by the holder 10. Then, the inner ring 12 is pushed deep into the step portion 13 with the tapered rollers 18, 18 arranged around the inner ring 12. The pushing operation of the inner ring 12 is performed by a pushing jig (not shown) abutting the other end surface of the inner ring 12.

However, in the case of the present invention, such a pressing operation of the inner ring 12 is not performed at a stretch. That is, in the case of the present invention, the operation of pushing the inner ring 12 is
Is stopped shortly before one end surface thereof contacts the step surface 17 of the step portion 13. That is, as shown in FIG. 1, the pressing operation of the inner race 12 is performed such that the rolling surfaces of the plurality of tapered rollers 18 arranged around the second inner raceway 9a are in contact with the second outer raceway 5a. Stop once before contact. In this state, the internal clearance of the bearing portion in the axial direction is positive (no preload has yet been applied to this bearing portion). When the pushing operation of the inner ring 12 is temporarily stopped in this way, the outer ring 1 is moved in the axial direction (the left-right direction in FIG. 1) in this state, and the range in which the outer ring 1 can move in the axial direction (dimension L). Is measured. This dimension L corresponds to the internal clearance (positive value) of the bearing portion in the axial direction in the state shown in FIG.

When such a measurement of the dimension L is performed,
Then, the work of pushing the inner ring 12 is resumed, and as shown in FIG. 2, one end surface of the inner ring 12 is brought into contact with the step surface 17 to complete the bearing portion, and in the axial direction of the bearing portion. The gap that spans is made negative. That is, in this state, a preload is applied to the bearing portion. At the same time, the amount of movement P of the inner ring 12 in the axial direction until the one end face of the inner ring 12 comes into contact with the step surface 17 after restarting the pushing operation of the inner ring 12 is measured. Note that this movement amount P
Is larger than the dimension L (P> L). Such a measurement of the movement amount P is performed, for example, as follows. First, in a state before resuming the pushing operation shown in FIG. 1, one end surface (first reference surface) of the flange 7 provided on the hub body 11 and the other end surface (second reference surface) of the inner ring 12 are formed. measuring the axial dimension S ₁ between the further state after pushing completion shown in FIG. 2, these first measures the axial dimension S ₂ between the second double reference faces. Then, the movement amount P is calculated as P = S
Calculated as ₁ -S _2. In measuring the movement amount P in this way, various methods can be selected for the first reference surface on the hub body 11 side and the second reference surface on the inner ring 12 side. Further, when the pushing amount of the pushing jig can be measured, the moving amount P can be measured from the pushing amount.

After the movement amount P is obtained as described above, the size of the internal clearance in the axial direction of the bearing portion completed as described above is obtained as LP (negative value). The size of the internal gap in the axial direction, which is obtained in this manner, is the size of the preload applied to the bearing. Then, the magnitude of the preload thus obtained is compared with the initially set appropriate amount of the preload. As a result of this comparison, if the magnitude of the preload obtained as described above substantially matches the appropriate amount, the process proceeds to the next assembly process. Conversely, if the magnitude of the preload determined as described above is not negligibly different from the appropriate amount, the preload may be repelled (removed) from the assembly line, or some of the components (for example, Replace the inner ring 12) and reassemble.

If the magnitude of the preload obtained as described above substantially coincides with the appropriate amount, then the hub body 1
The cylindrical portion 22 provided at the other end of the plastic ring 1 is plastically deformed radially outward to form a caulked portion 14 (see FIG. 5), and the caulked portion 14 suppresses the other end surface of the inner ring 12. Finally, the inner peripheral surface of the other end of the outer race 1 and the inner race 1
The seal ring 19 (see FIG. 5) is mounted in a state where the space between the outer peripheral surface of the second end and the outer peripheral surface of the second end is sealed. Note that the other end surface of the inner ring 12 may be suppressed by a nut 21 (FIG. 5).
The other end of the space in which the tapered rollers 18, 18 are installed is connected to a cover 16 (FIG. 3) attached to the other end of the outer race 1.
To 4).

According to the method for measuring the internal clearance according to the present invention as described above, the internal clearance in the axial direction of the bearing portion constituting the double-row tapered roller bearing unit for supporting the wheel is determined.
Easy and accurate measurement at the stage of assembly work. Because of this,
In a state where the double-row tapered roller bearing unit for wheel support is completed, it is possible to confirm whether or not an appropriate amount of preload is applied to the bearing portion. Further, in the case of the present invention, such confirmation of the preload amount can be performed as a 100% inspection in the bearing unit assembly line. For this reason, a reliable product of good quality can be provided.

[0024]

As described above, according to the method for measuring the internal clearance of the double-row tapered roller bearing unit for supporting wheels according to the present invention, it is determined whether or not an appropriate amount of preload has been applied to the bearing portion. It is easy and accurate to know at the work stage.
Further, such a measurement of the preload amount can be performed as a 100% inspection in the bearing unit assembly line. For this reason, a reliable product of good quality can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of the present invention at an intermediate stage of an assembling operation.

FIG. 2 is a cross-sectional view similarly shown in the next stage of FIG. 1;

FIG. 3 is a sectional view showing a first example of a rolling bearing unit for supporting wheels.

FIG. 4 is a sectional view showing the second example.

FIG. 5 is a sectional view showing a first example of a double-row tapered roller bearing for supporting wheels.

FIG. 6 is a sectional view showing the second example.

[Explanation of symbols]

 Reference Signs List 1 outer ring 2 hub 3 ball 4, 4a first outer ring track 5, 5a second outer ring track 6 mounting portion 7 flange 8, 8a first inner ring track 9, 9a second inner ring track 10 retainer 11 hub body 12 Inner ring 13 Stepped portion 14 Caulked portion 15 Seal ring 16 Cover 17 Stepped surface 18 Tapered roller 19 Seal ring 20 Male thread 21 Nut 22 Cylindrical

Claims (1)

[Claims] 1. An outer ring having first and second outer raceways formed on an inner peripheral surface, each having a conical concave surface and inclined in opposite directions, and an outer ring having an outer peripheral surface, each having a conical convex shape inclined in opposite directions. Hubs forming first and second inner raceways, and tapered rollers provided in such a manner as to freely roll a plurality of each between the first and second inner raceways and the first and second outer raceways. The hub comprises a hub body having the first inner raceway formed on the outer peripheral surface thereof, and an inner ring having the second inner raceway formed on the outer peripheral surface thereof. At the end of the outer peripheral surface, a step portion having a smaller diameter than the portion where the first inner ring raceway is formed is formed, and the inner ring has one end surface in the axial direction at the base end portion of the step portion. The outer surface is fitted with the existing step surface in contact with the existing step surface, and the other end surface in the axial direction is fixed by the fixing means. It is a method of measuring the internal clearance of the double row tapered roller bearing unit for wheel support, which is supported and fixed to the hub body, by assembling the double row tapered roller bearing unit for wheel support,
When the inner ring is fitted over the distal end of the step, and the inner ring is pushed toward the base end of the step, first, the pushing operation is performed such that one end surface of the inner ring contacts the step surface. Shortly before contact, and before the rolling surfaces of the plurality of rolling elements arranged around the second inner raceway contact with the second outer raceway, temporarily stop the outer race in this state. By moving the outer ring in the axial direction, an axial dimension L in which the outer ring is movable in the axial direction is measured. Then, the pushing operation of the inner ring is restarted, and one end surface of the inner ring is brought into contact with the step surface. At the same time, by measuring the axial movement amount P of the inner ring from when the pushing operation is resumed until one end surface of the inner ring comes into contact with the step surface, the size of the internal clearance in the axial direction of the bearing portion is measured. Wheel support Method of measuring the internal clearance of the tapered roller bearing unit.