JP2010001911A - Fixing method of bearing and rotation-linear motion converting mechanism with bearing using the fixing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing method of a bearing capable of surely fixing an outer ring by caulking and a rotation-linear motion converting mechanism with the bearing using the fixing method. <P>SOLUTION: The bearing for receiving a load in an axial direction is provided in the rotation-linear motion converting mechanism for converting a rotation motion into a linear motion. On caulking, the outer ring 81 of the bearing is inserted into a holder 90 and then a distal end part of the holder 90 is bent in a central axial direction of the outer ring 81 to form a caulking part 93. Caulking is executed while a plate 120 formed of a material of which Young's modulus is smaller than that of the outer ring 81 is contacted with an end surface 81B of a side which is arranged in the axial direction of the outer ring 81 and is caulked. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for fixing an outer ring of a bearing to a holder and a rotation-linear motion conversion mechanism provided with a bearing by the fixing method.

Conventionally, various methods for fixing a bearing by caulking have been proposed (for example, Patent Documents 1 to 3).
JP 2004-239338 A Japanese Utility Model Publication No. 63-20541 JP 2000-145797 A

  Incidentally, as shown in FIG. 4, after the outer ring 500 of the bearing is inserted into the holder 600, the front end portion 610 of the holder 600 is caulked and the front end portion 610 is bent in the central axis direction of the outer ring 500. By doing so, the caulking portion 620 can fix the outer ring 500 to the holder 600 in the axial direction. However, when the outer ring 500 is fixed to the holder 600 in this way, the following inconvenience may occur.

  That is, as shown in FIG. 5, when the caulking process is finished and the pressing force by the caulking process does not act on the caulking part 620, the caulking part 620 is slightly separated from the end surface 510 of the outer ring 500 by the spring back. A gap S is generated between the caulking portion 620 and the end surface 510. For this reason, the outer ring 500 may not be fixed in the axial direction by the caulking portion 620, and the outer ring may not be reliably fixed by caulking.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bearing fixing method capable of more reliably fixing an outer ring by caulking, and a rotary-linear motion including a bearing by the fixing method. It is to provide a conversion mechanism.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, after the outer ring of the bearing is inserted into the holder, the tip of the holder is bent in the direction of the central axis of the outer ring to perform a caulking process to make the outer ring the holder. The method of fixing the bearing to be fixed to
The gist of performing the caulking process in a state in which an interposition member formed of a material having a Young's modulus smaller than that of the outer ring is in contact with an end surface on the side where the caulking process is performed in the axial direction of the outer ring. And

  According to this method, by performing caulking, the interposed member is held between the end face in the axial direction of the outer ring and the caulking portion. Here, since the interposed member is made of a material having a Young's modulus smaller than that of the outer ring, the amount of deformation of the interposed member is larger than the amount of deformation of the outer ring when the end surface of the outer ring is directly pressed by the caulking portion. Becomes larger and the intervention member is compressed. Therefore, the bending amount of the caulking portion when the caulking portion is formed by bending the tip portion of the holder increases, and the caulking portion comes into sufficient contact with the interposed member. In addition, when the caulking process is finished and the pressing force during the process does not act on the caulking part, both the caulking part and the interposition member are restored to some extent by the spring back, but the restoring force at that time is the compression force The interposed member becomes larger, and compressive residual stress is generated in the interposed member. When the reaction force of the compressive residual stress acts on the caulking portion, the axial force of the caulking portion for holding the end surface of the outer ring is secured via the interposition member, and the contact state between the caulking portion and the end surface of the outer ring is secured. Is preferably maintained. Therefore, also by this method, the outer ring can be more reliably fixed by caulking. In this method, it is desirable that the outer ring is made of an iron-based material (for example, bearing steel) and the interposed member is made of an aluminum alloy.

  According to a second aspect of the present invention, there is provided a rotation-linear motion conversion mechanism for converting rotational drive to linear motion, wherein a bearing provided in the mechanism and receiving a load in the axial direction is a method according to the first aspect. The gist is fixed.

  In a bearing that is provided in a rotation-linear motion conversion mechanism that converts rotational movement into linear motion and receives a load in the axial direction, the outer ring is removed from the holder if the axial direction is not sufficiently fixed. There is a risk of shifting. In this regard, according to the same configuration, such a bearing is fixed by the above-described method, so that the outer ring can be fixed to the holder in the axial direction by the caulking portion, and the outer ring is fixed by such caulking. Is also surely done. Accordingly, it is possible to suitably suppress the outer ring of the bearing provided in the rotation / linear motion conversion mechanism from being displaced from the holder.

  Hereinafter, an embodiment in which a bearing fixing method according to the present invention is embodied as a bearing fixing method provided in a rotation-linear motion conversion mechanism will be described with reference to FIGS.

FIG. 1 shows a schematic configuration of a rotation / linear motion converting mechanism to which the bearing fixing method according to the present embodiment is applied.
As shown in FIG. 1, a motor 62 having a stator 62 a having a coil C and a rotor 62 b having a permanent magnet inside the housing 61 of the rotation-linear motion conversion mechanism 60, and rotational movement of the motor 62 are provided. A gear mechanism 70 is provided that converts the linear motion into a shaft 71 and transmits it to the shaft 71.

  The gear mechanism 70 includes an outer cylinder 72 that is rotated by a motor 62, a gear unit that is provided inside the outer cylinder 72 and converts rotational motion into linear motion, and the shaft to which the converted linear motion is transmitted. 71.

On the outer peripheral surface of the outer cylinder 72, a double-row angular bearing 80 and the rotor 62b are provided so as to be integrally rotatable.
The bearing 80 includes an outer ring 81, inner rings 82 and 83, and two ball rows 82A and 83A corresponding to the inner rings 82 and 83, respectively.

  The outer ring 81 is made of bearing steel (for example, high carbon chromium bearing steel) and is inserted into a holder 90 fixed to the housing 61. The holder 90 is made of iron (for example, carbon steel).

The inner rings 82 and 83 are also made of bearing steel (for example, high carbon chrome bearing steel), and are arranged in parallel between the stoppers 100 and 101 fitted on the outer peripheral surface of the outer cylinder 72.
A washer 102 is provided in a compressed state between the stopper 100 and the inner ring 82, and the displacement of the inner rings 82 and 83 is suppressed by the elasticity of the washer 102.

  With such a bearing 80, a radial load (load acting in a direction perpendicular to the central axis of the bearing 80) and an axial load (load acting in a closing direction with respect to the central axis of the bearing 80) are applied to the gear mechanism 70. Is accepted.

  By the way, since the load applied to the bearing 80 in the axial direction of the shaft 71, that is, the load in the axial direction, is applied, the outer ring 81 may be displaced from the holder 90 if the axial direction is not sufficiently fixed. There is.

Therefore, in the present embodiment, the outer ring 81 is fixed to the holder 90 as follows.
FIG. 2 shows an enlarged view in the vicinity of the outer ring 81 (enlarged view of A portion in FIG. 1). As shown in FIG. 2, in this embodiment, after inserting the outer ring 81 into the insertion hole 91 formed at the end of the holder 90, the tip end 92 of the holder 90 is bent in the central axis direction of the outer ring 81. A caulking process for forming the caulking portion 93 is performed.

  In the caulking process, the caulking process is performed in a state where an annular plate 120 formed of an aluminum alloy is in contact with the end surface 81B on the side where the caulking process is performed in the axial direction of the outer ring 81. The plate 120 is sandwiched between the end face 81 </ b> B and the caulking portion 93 by inserting the outer ring 81 into the insertion hole 91 of the holder 90 and then inserting the outer ring 81 into the insertion hole 91. The plate 120 constitutes the interposition member.

  According to such a fixing method, since the plate 120 is formed of an aluminum alloy having a Young's modulus smaller than that of the outer ring 81 formed of bearing steel, the outer ring 81 when the end surface of the outer ring 81 is directly pressed by the caulking portion 93. The deformation amount of the plate 120 is larger than the deformation amount of the plate 120, and the plate 120 is compressed. Therefore, the amount of bending of the caulking portion 93 when forming the caulking portion 93 by bending the tip portion 92 of the holder 90 increases, and the caulking portion 93 comes into sufficient contact with the plate 120. Further, when the caulking process is finished and the pressing force at the time of the process does not act on the caulking part 93, both the caulking part 93 and the plate 120 are restored to some extent by the spring back, but the restoring force at that time is As shown in FIG. 3, the plate 120 compressed by the compression allowance Cm is larger. Therefore, the compressive residual stress Fa is generated in the plate 120, and the reaction force Fb of the compressive residual stress Fa acts on the caulking portion 93 to hold the end surface 81B of the outer ring 81 through the plate 120. The axial force of the caulking portion 93 is ensured, and the contact state between the caulking portion 93 and the end surface 81B is appropriately maintained.

  Therefore, according to the fixing method of the present embodiment, the outer ring 81 can be more reliably fixed by caulking. Accordingly, it is also possible to suitably suppress the outer ring 81 of the bearing 80 provided in the rotation-linear motion converting mechanism 60 and receiving a load in the axial direction from being displaced from the holder 90.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The outer ring 81 of the bearing 80 is fixed to the holder 90 by caulking the tip portion 92 of the holder 90. In carrying out such a bearing fixing method, a plate 120 made of a material having a smaller Young's modulus than the outer ring 81 is brought into contact with an end surface 81B on the side where the caulking process is performed in the axial direction of the outer ring 81. Caulking is performed. As a result, the outer ring 81 can be more reliably fixed by caulking.

  (2) The outer ring 81 of the bearing 80 which is provided in the rotation-linear motion conversion mechanism 60 and receives a load in the axial direction is fixed to the holder 90 by the above method. Therefore, it is possible to suitably suppress the outer ring 81 of the bearing 80 that is provided in the rotation-linear motion conversion mechanism 60 and is subjected to a load in the axial direction from being displaced from the holder 90.

In addition, the said embodiment can also be changed and implemented as follows.
-Although plate 120 was formed with aluminum alloy, it may be formed with other materials. In short, if it is made of a material having a Young's modulus smaller than that of the outer ring 81, the same effect can be obtained.

  In the above embodiment, the case where the bearing fixing method according to the present invention is applied to the bearing 80 that is provided in the rotation-linear motion converting mechanism 60 and receives a load in the axial direction has been described. However, the present invention can be similarly applied to other bearing fixing methods provided in other mechanisms, and even in this case, the outer ring of the bearing can be more reliably fixed by caulking. become.

Sectional drawing which shows the structure of the rotation-linear motion conversion mechanism with which this is applied about one Embodiment of the fixing method of the bearing concerning this invention. The A section enlarged view of FIG. The enlarged view of the outer ring | wheel edge part in the embodiment. The enlarged view of the outer ring vicinity which shows the fixation aspect of the outer ring by the conventional crimping process. The enlarged view of the outer ring vicinity which shows the fixation aspect of the outer ring by the conventional crimping process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 60 ... Rotation-linear motion conversion mechanism, 61 ... Housing, 62 ... Motor, 62a ... Stator, 62b ... Rotor, 70 ... Gear mechanism, 71 ... Shaft, 72 ... Outer cylinder, 80 ... Bearing, 81 ... Outer ring, 81B ... End face , 82 ... inner ring, 82A, 83A ... ball array, 90 ... holder, 91 ... insertion hole, 92 ... tip part, 93 ... caulking part, 100, 101 ... stopper, 102 ... washer, 120 ... plate, 500 ... outer ring, 510 ... end face, 600 ... holder, 610 ... tip part, 620 ... caulking part.

Claims (2)

This is a bearing fixing method for fixing the outer ring to the holder by inserting the outer ring of the bearing into the holder and then bending the tip of the holder in the direction of the central axis of the outer ring to form a caulking part. And
The caulking process is performed in a state in which an interposition member formed of a material having a Young's modulus smaller than that of the outer ring is brought into contact with an end face on the side where the caulking process is performed in the axial direction of the outer ring. How to fix the bearing. The rotation-linear motion conversion mechanism that converts the rotational behavior into linear motion, and the bearing that receives the load in the axial direction is fixed by the method according to claim 1. Dynamic conversion mechanism.

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