JP2002098127A - Locking device for nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a fastening position of a nut which secures a bearing at a proper range. SOLUTION: A tapered roller bearing 3 is mounted between a hollow spindle 1 and a wheel hub 2 of a final reduction gears for a vehicle and the bearing 3 is secured by a screw thrust of a first nut 11 engaged with a male screw 9 of the hollow spindle 1. A protrusion 20 of a washer 13 is inserted antirotation-wise into a key-way 24 of the hollow spindle and a pawl 21 of the washer 13 is so formed as to be fitted bendably into the outer periphery groove 18 of the first nut 11. A nut hight H of the first nut 11 is so configured that a screw starting position of a right side bearing surface 31 and a screw termination position of a left side bearing surface 32 of the first nut 11 is dislocated in the circumferential direction by a number of revolutions equivalent to a reciprocal of value of two times of installation numbers of the outer periphery groove 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing a nut for fixing a member to be tightened such as a bearing from being loosened.

[0002]

2. Description of the Related Art Conventionally, this kind of anti-loosening device includes:
There is one described in JP-A-10-324108. The prior art is configured as follows. A conical roller bearing is mounted between the hollow spindle of the final reduction gear of the vehicle and the wheel hub, and the bearing is pressed in the axial direction by a screw thrust of a nut screwed into a male screw of the hollow spindle. The washer is engaged with the hollow spindle in a detent shape, and the locking claw of the washer is engaged with the outer peripheral groove of the nut in a detent shape.

[0003]

When the above-described conical roller bearing is assembled, a preload (preload) may be applied in order to increase rigidity or increase rotational accuracy and positional accuracy. In order to apply the preload, a fixed position preload is generally adopted, and the nut is tightened and fixed at an appropriate position. After tightening the nut in this way, the locking claws of the washer are folded into the outer peripheral groove of the nut. However, even though the nut is at an appropriate position to apply a preload, if the outer circumferential groove of the nut and the locking claw are displaced in the circumferential direction, the outer circumferential groove is not It was necessary to rotate the nut until it matched the locking pawl. For this reason, there is a possibility that an appropriate preload cannot be applied. SUMMARY OF THE INVENTION It is an object of the present invention to maintain a preload within an appropriate region when assembling a conical roller bearing or the like for controlling a preload by a nut tightening condition.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, for example, as shown in FIGS. 1 to 3, a nut locking device is constituted as follows. A nut 11 screwed to the male screw member 1 to press the member 3 to be tightened in the axial direction, and a washer 13 engaged with the male screw member 1 in a detent shape are provided on a peripheral wall of the nut 11. A plurality of locked parts 18 are provided at predetermined intervals in the direction,
A locking portion 21 that engages with the locked portion 18 in a detent-like manner is provided on the washer 13, and a screw start position S on one seat surface 31 of the nut 11 and a screw end on the other seat surface 32 of the nut 11 are provided. The height of the nut between the two seating surfaces 31 and 32 is adjusted so that the position E is displaced in the circumferential direction by the number of rotations corresponding to the reciprocal of a value obtained by multiplying the number N of the locked portions 18 by a natural number. H is set.

[0005] The invention of claim 1 has the following effects. When the nut screwed to the male screw member is tightened to a position where a predetermined preload is applied, if there is a large circumferential displacement between the locked portion of the nut and the locking portion of the washer, first, The nut and the washer are removed from the male screw member, and then the nut is turned upside down and screwed into the male screw member, and then the nut is tightened to a position where a predetermined preload is applied. In the tightened state of the back seat surface, compared to the tightened state of the front seat surface, the rotational position of the nut corresponds to the reciprocal of a value obtained by multiplying the installation number of the locked portion by a natural number. , The positional deviation between the locking portion and the locked portion is reduced. Therefore, the tightening position of the nut can be kept within an appropriate region. As a result, the assembly accuracy of the member to be tightened such as a bearing is improved.

According to a second aspect of the present invention, when the natural number multiple in the first aspect is doubled, when the nut is turned upside down and tightened, the adjacent locked elements are locked. The above-mentioned locked portion can be displaced in the circumferential direction by half the circumferential interval of the portion. For this reason, the same effect as the case where the number of the locked portions of the nut is doubled can be obtained. As a result, the positional deviation between the locked portion and the locking portion in the circumferential direction is extremely reduced, and the tightening position of the nut can be reliably maintained in an appropriate region.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
3 will be described with reference to FIG. This embodiment illustrates a case where the locking device of the present invention is applied to a bearing portion of a final reduction gear of a vehicle. FIG. 1 is a sectional view of the bearing portion. FIG. 2 is a right side view of the nut of the locking device. FIG. 3 is a right side view of a washer of the same locking device.

As shown in FIG. 1, a hollow spindle 1 and a wheel hub 2 which are male screw members are coaxially arranged, and a conical roller bearing 3 is mounted between these two members. Here, the cone roller bearing 3 described above is used.
Are schematically shown, reference numeral 4 is an inner ring, reference numeral 5 is an outer ring,
Reference numeral 6 denotes a rolling roller. The left part of the drive shaft (not shown) inserted into the hollow spindle 1 is a connecting block.
(Not shown) and is fixed to the left part of the wheel hub 2.

The first screw 9 of the hollow spindle 1 is
Female thread 11a of nut 11 and female thread 1 of second nut 12
2a are screwed in order and these two nuts 1
A ring-shaped washer 13 with a claw is mounted between 1 and 12. Then, the outer ring 5 of the bearing 3 is pressed against the stepped portion 2a of the wheel hub 2 by the screw thrust of the nuts 11 and 12, and the inner ring 4 is tapered of the hollow spindle 1. It is pressed against the start end of the surface 1a.

The two nuts 11 and 12 are prevented from loosening by the washer 13. Hereinafter, the structure of the loosening prevention will be described. The above two nuts 11.1
2 have the same shape and dimensions, so that the first nut 11
Will be described only. As shown in FIG.
Four peripheral grooves (locked portions) 18 are formed on the peripheral wall of the nut 11.
It is provided at a pitch of 90 degrees. Also, as shown in FIG.
A protrusion 20 for preventing rotation is protruded inward in the radial direction from the inner peripheral surface of the washer 13. Further, a plurality of claws (locking portions) 21 are provided on the outer peripheral portion of the washer 13 at predetermined intervals in the circumferential direction.

The projection 20 is fitted in the keyway 24 of the male screw 9 of the hollow spindle 1. Thus, the washer 13 is prevented from rotating. Further, as shown in FIG. 1 (and FIG. 3), one of the plurality of claws 21a is bent rightward to fit into the outer circumferential groove 18 of the first nut 11, and Another claw 21b of the plurality of claws 21 is bent leftward and fitted into the outer peripheral groove 18 of the second nut 12. Thus, the rotation of the nuts 11 and 12 is prevented.

Further, the screw start position S of the right front seat surface 31 and the screw end position E of the left back seat surface 32 of the two left and right seat surfaces of the first nut 11 are defined by the outer peripheral groove. 1
Number N of 8 (4 in this case) multiplied by a natural number (2 in this case)
In order to displace clockwise by the number of revolutions (here, 1/8 rotation) corresponding to the reciprocal of the value obtained above,
The nut height H is set between 32.

More specifically, the first nut 1
Assuming that the standard number of turns of the female screw 11a is A and the screw pitch is P, assuming that 1 is a standard product, the nut height H is obtained by the following equation or equation. Formula: H = [A + (1 / 2N)] P Formula: H = [A- (1 / 2N)] P In other words, the first nut 11 is formed by the female screw 11
The actual number of turns of “a” is increased or decreased by the number of turns corresponding to the reciprocal of a value obtained by multiplying the number of installations N of the outer peripheral groove 18 by a natural number (here, twice) as compared with the standard number of turns A. In addition,
It is preferable that the standard winding number A is a numerical value that becomes a natural number when multiplied by a natural number (here, doubled).

Incidentally, when the internal thread 11a of the first nut 11 is M75 · P2 and the standard nut height h is 13 mm assuming a standard product, A = h
By substituting /P=13/2=6.5 (roll), N = 4, and P = 2, H = [6.5 + 1/8] · 2 = 13.25 (mm). When the same numerical values as above are substituted into the above equation, H becomes 12.75 (mm). Therefore, as the nut height H of the first nut 11 (and the second nut 12), a slightly thick 13.25 mm or a slightly thin 12.75 mm is used instead of the standard nut height h (13 mm). Become. Incidentally, the screw end position E in 2 above figures, Yes exemplifies a case where a little thick standard nut height, the E ₁ is when the standard nut height slightly thinner.

The conical roller bearing 3 mounted between the hollow spindle 1 and the wheel hub 2 is tightened in the following procedure. First, the first nut 11 is attached to the male screw 9 with the front seat surface 31 turned rightward.
And the first nut 11 is tightened to a predetermined position by a jig fitted into the plurality of outer peripheral grooves 18. Next, the protrusion 20 of the washer 13 is fitted into the key groove 24, and the washer 13 is moved rightward along the key groove 24, and the left back surface of the first nut 11 is moved. 32.

At this time, if any one of the four outer circumferential grooves 18 and any one of the plurality of claws 21 are correctly faced, the claw 2 facing the face is not required.
1a is bent into the outer peripheral groove 18 described above. Further, when the positional deviation between the two in the circumferential direction is small, the tightening torque of the first nut 11 is finely adjusted so that the two are accurately opposed to each other. Groove 18
Bend in.

On the other hand, if the positional deviation in the circumferential direction is large, the washer 13 and the first nut 11 are removed from the male screw 9 and the first nut 11 is turned upside down. The first nut 11 is screwed so as to be in a predetermined position.
Then, in the tightened state of the back seat surface 32, the first nut 11 is compared with the tightened state of the front seat surface 31.
Is displaced by 1/2 N rotation (= 1/8 rotation), so that the positional deviation between the claw 21a and the outer peripheral groove 18 is reduced. For this reason, it is only necessary to finely adjust the tightening position of the first nut 11 so that the two are accurately opposed to each other, and then bend the claw 21 a into the outer peripheral groove 18.

In the same procedure as described above, the male screw 9
And the second nut 12 is screwed into the second nut 12
To the predetermined position and the second nut 12
Of the plurality of claws 21 in the outer circumferential groove 18
1b is bent.

The above embodiment can be modified as follows. The number N of the outer peripheral grooves 18 which are the locked portions is not limited to the four illustrated, but may be two or three.
Or five or more. Instead of providing a large number of the claws 21 as the locking parts as illustrated, instead of providing at least one for the first nut 11 and providing at least one for the second nut 12, Good.
The circumferential displacement between the screw start position S and the screw end position E is not limited to the number of rotations corresponding to the reciprocal of a value twice as large as the number N of installations described above. The number of rotations may be any number corresponding to the reciprocal of the value of a natural number multiple.

The respective locked portions of the first and second nuts 11 and 12 are replaced by the nuts 11 instead of the illustrated outer circumferential grooves 18.
A hole provided on the outer peripheral surface or side surface of the 12 peripheral walls may be used.
In this case, the locking portion of the washer 13 is
It is conceivable to use protrusions instead of. It is also possible to configure each of the nuts 11 and 12 by a square nut such as a hexagonal nut, for example, and to form the locked portion by each side surface of the square nut. Further, it is also possible to configure the locked portions of the nuts 11 and 12 with claws or projections, and to configure the locking portions of the washer 13 with grooves or holes.

The nut for pressing the conical roller bearing 3 is
Instead of the two illustrated nuts 11 and 12, only one nut 11 may be used. The locking device of the present invention
It is not limited to the tightening and fixing of the illustrated bearing,
It is also applicable to various other uses.

[Brief description of the drawings]

FIG. 1 is a sectional view of a bearing portion to which a locking device according to the present invention is applied.

FIG. 2 is a right side view of a nut of the locking device.

FIG. 3 is a right side view of a washer of the same locking device.

[Explanation of symbols]

1 ... male screw member (hollow spindle), 3 ... member to be tightened (conical roller bearing), 11 ... nut (first nut), 13 ...
Washer, 18: locked part (outer peripheral groove), 21: locked part (claw), 3
1 ... one seat surface (front seat surface), 32 ... the other seat surface (back seat surface),
S: screw start position, E: screw end position, N: locked part
(Outer peripheral groove) Number of 18 installed, H: Nut height.

Claims (2)

[Claims] 1. A member to be tightened which is screwed to a male screw member (1).
A nut (11) for pressing (3) in the axial direction, and a washer (13) for engaging the male screw member (1) in a detent-like manner;
A plurality of locked portions (18) are provided on the peripheral wall of the nut (11) at predetermined intervals in the circumferential direction, and the locking portions (18) are engaged with the locked portions (18) in a detent-like manner. 21) washer (13) above
And the screw start position of one of the bearing surfaces (31) of the nut (11).
(S) and the screw end position (E) of the other seating surface (32) are the number of rotations corresponding to the reciprocal of a value obtained by multiplying the number of installations (N) of the locked parts (18) by a natural number. The nut height (H) between the two bearing surfaces (31) and (32) was set so as to be displaced in the circumferential direction.
A device for preventing loosening of a nut. 2. The device for preventing loosening of a nut according to claim 1, wherein the natural number is twice as large.