JP2009168043A - Screw fastening device for bearing member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more securely prevent slack of a nut due to torque originating in vibration of a shaft system and external force by a ring member of an inner periphery of the nut. <P>SOLUTION: The nut 7 is fastened to a screw shaft 5 provided on one end part in the axial direction of a rotation shaft 2 supported by a bearing 3 so as to fasten an inner wheel 4 of the bearing 3, etc. The ring member 8 fitted to a concave part 7b of the nut 7 is an endless ring formed of resin softer than the steel screw shaft 5 and the nut 7. During carrying out fastening by the screw shaft 5 and the nut 7, female-screw cutting of a plurality of pitches is carried out to the ring member 8 by a male screw 5a. Friction torque for resisting returning rotation of the nut 7 is made to be larger at a strong screw-connection part of the ring member 8 and the male screw 5a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a screw fastening device for a bearing member for fastening a bearing member such as a bearing component or an accessory by screwing a screw shaft and a nut.

When fixing the bearing ring or the spacer to the shaft or fixing the side plate of the pin type cage, screw fastening is employed (for example, Patent Document 1 and Patent Document 2).
In the bearing member, rotational vibration, linear vibration, and impact vibration from each direction derived from the shaft system are transmitted, and these vibrations can be torque that rotates the nut to the return side. For this reason, in the above-described screw fastening, a nut provided with a detent means is used.

Conventionally, as a means for preventing return rotation only on the nut side, a recess that is larger than the inner diameter of the female screw is formed on the inner periphery of the nut, a ring member fitted in the recess is fixed, and the ring is engaged by screwing the nut and the screw shaft. There is a member in which the member is elastically contacted with a male screw to increase the friction torque that resists the rotation of the nut.
For example, a recess is formed on the inner periphery of a nut, a ring member fitted in the recess is fixed, and a C-shaped elastic piece of the ring member protrudes from the inner diameter of the female screw. When this nut is screwed onto the screw shaft, the C-shaped elastic piece of the ring member is made of a thin metal plate. Therefore, when it comes into contact with the thread of the male screw, it easily advances elastically and then proceeds through the valley. By pushing the advance flank of the male screw by the action, the friction torque resisting the return rotation of the nut can be increased (Patent Document 3).

JP 2006-132765 A (FIG. 3, paragraph 0032) JP 2002-206536 A (abstract) JP 2000-65031 A

  Since the nut described in Patent Document 3 is screwed while elastically deforming the C-shaped elastic piece portion of the ring member made of a thin metal plate, the C-shaped elastic piece portion is in contact with only one pitch thread of the male screw. The slack prevention effect obtained by the ring member is limited.

  In view of the above circumstances, an object of the present invention is to more reliably prevent a nut that fastens a bearing member from returning and rotating with torque derived from shaft vibration or external force.

  In order to achieve the above object, the present invention includes a screw shaft and a nut for fastening a bearing member, a recess that is larger in diameter than a female screw inner diameter is formed on the inner periphery of the nut, and a ring member fitted in the recess is fixed. In the screw fastening device for a bearing member in which the ring member is elastically contacted with the male screw by screwing the nut and the screw shaft to increase the friction torque that resists the return rotation of the nut, the screw shaft and the nut During the fastening, a plurality of pitches of female threading is performed on the ring member by the male screw, and the friction torque is increased at the threaded portion of the ring member and the male screw.

Specifically, the ring member is fixed to a recess that is larger in diameter than the internal diameter of the female screw on the inner periphery of the nut, and when the nut is screwed, the fixed portion remains even if the internal thread is cut by the external thread. be able to. Since the female threading of the ring member is performed while the screw shaft and the nut are fastened, the ring member is brought into a fastening state after the female threading is forcibly performed. At this time, the female screw that is forcibly formed on the ring member is in strong elastic contact with the male screw of the screw shaft, so that the nut is rotated back while securing the axial force of the screw fastening at the threaded portion of the nut and screw shaft. The resisting friction torque can be increased.
Here, since the threaded portion of the ring member and the screw shaft performs female threading on the ring member, it is not limited to one pitch as in the conventional C-shaped elastic piece portion, and can be over a plurality of pitches. If the friction area extends over a plurality of pitches of the ring member and the screw shaft, the ring member can more reliably prevent the nut that fastens the bearing member from rotating due to the vibration of the shaft system or external force to rotate. Can do.

  Examples of the bearing member include bearing parts and accessories. The bearing parts are individual parts constituting the bearing, and examples thereof include a bearing ring, a cage, a collar ring, and a spacer. The accessory is a part provided in the shaft system for causing the bearing to function, and examples thereof include a housing, an adapter, and a removal sleeve.

The ring member is not particularly limited in material as long as it exhibits the above-described action.
For example, if the ring member is formed of a resin or metal that is softer than the material of the male screw, the male screw is less likely to be damaged. Furthermore, it is possible to prevent the nut from loosening by utilizing the elasticity of resin or metal for the female thread of the ring member.
For example, when the screw shaft is made of steel, polyamide (PA) or the like can be used as the resin.
As the metal, for example, when the screw shaft is made of steel, copper, tin, lead, or an alloy thereof such as gun metal or brass can be used.

Here, when the male screw of the screw shaft is formed from a metal, the ring member is preferably formed from a metal capable of suppressing adhesion with the male screw.
If the ring member and the male thread are formed of the same metal, adhesion is likely to occur during female threading, and the ring member may be seized.
If the ring member is formed of a metal that can suppress adhesion with the male screw, adhesion between the screw shaft and the ring member can be prevented.
In addition, the metal with which adhesion with the said male screw is suppressed means the metal used as the combination with which the said adhesion is suppressed on the basis when the ring member is formed with the same metal as the metal of the male screw.
When the screw shaft is made of metal, it is common to use a nut made of metal. However, the ring member can prevent the nut from loosening, so it is possible to avoid loosening prevention by tightening the nut and the screw shaft. . This is effective in preventing seizure due to adhesion of the female screw of the nut and the male screw of the screw shaft. This effect can be obtained regardless of whether the female screw of the nut and the male screw of the screw shaft are made of the same metal.

  As an example, the structure which provided the said screw shaft in the axial direction one end part of the rotating shaft supported by a bearing is mentioned. Even if the rotation direction of the rotary shaft and the return rotation direction of the nut coincide with each other, it is possible to reliably prevent the looseness of the rotation-side raceway ring and the spacer.

As another example, the structure which provided the said screw shaft in the axial direction one end part of the pin inserted in the annular body and hollow roller of a pin type holder | retainer is mentioned. Even if the rotation direction of the cage pushed by the rolling element in accordance with the rotation of the rotating shaft matches the return rotation direction of the nut, it is possible to reliably prevent the loose loosening of the annular body.
In addition, the pin type cage inserts the pin that becomes the pillar portion into the hollow roller, and fixes both ends of the pin to both annular bodies of the cage.In the hollow cylindrical roller or the tapered roller, a single row, It can be applied regardless of the bearing type such as double row.

  As described above, according to the present invention, the friction between the ring member and the male screw of the screw shaft is increased over a plurality of pitches, so that the nut for fastening the bearing member returns and rotates with the torque derived from the vibration of the shaft system and external force. This can be prevented more reliably.

Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the screw fastening device for a bearing member according to the first embodiment is for fixing an inner ring 4 of a bearing 3 incorporated between a housing 1 and a rotary shaft 2 in the axial direction.

  The rotating shaft 2 is supported by a bearing 3 including a pair of rolling bearings. A threaded shaft 5 having the same central axis as the shaft center is integrally provided at one end portion in the axial direction of the rotating shaft 2 by forming a parallel male thread on the outer periphery thereof.

  The inner ring 4 is prevented from moving toward the other end in the axial direction by a shoulder (not shown), a spacer or the like of the rotating shaft 2. The inner ring 4 and the spacer are fastened in the axial direction by screwing the nut 7 to the screw shaft 5 in a state where the sleeve 6 is in contact with the side surface of the inner ring 4 in the axial direction. As a result, the inner ring 4 is Fixed to the rotating shaft 2. When the rotating shaft 2 rotates, the inner ring 4 rotates around the same axis.

  FIG. 2A shows a state before the nut 7 is used. As shown in the figure, on the inner periphery of the nut 7, from the other end in the axial direction toward one end, a female screw 7a that is screwed into the male screw 5a of the screw shaft 5 and a recess 7b that is larger than the inner diameter of the female screw 7a are integrally formed. ing.

  A ring member 8 is fitted in the recess 7b. The ring member 8 is a cylindrical endless ring, and is positioned on the other end side in the radial direction and the axial direction with respect to the nut 7 by fitting in the recess 7b. In this positioned state, the ring member 8 is positioned on the one end side in the axial direction by the caulking portion 7 c formed on the one end portion in the axial direction of the nut 7. As a result, the ring member 8 is fixed to the nut 7 by friction with the inner wall surface of the recess 7b and the caulking portion 7c. The ring member 8 may be fixed to the recess 7b so that it does not move when the nut 7 is screwed, and other fixing directions such as adhesion can also be adopted.

  FIG. 2B shows an enlarged view of the nut 7 during tightening. As is apparent from the drawing, the nut 7 is screwed onto the screw shaft 5 from the female screw 7a. While the inner ring 4 and the like are fastened with the screw shaft 5 and the nut 7, more specifically, until the seat surface of the nut 7 abuts against the sleeve 6, a plurality of pitches are formed on the ring member 8 by the male screw 5 a. Female threading is performed. In the first embodiment, the inner diameter of the ring member 8 is made smaller than the inner diameter of the female screw 7a in order to ensure female threading.

  The ring member 8 is formed of a resin that is softer than the material of the male screw 5a. As a result, it is possible to prevent the external thread 5a from being damaged during the internal thread cutting. In this 1st Embodiment, the rotating shaft 2, the screw shaft 5, and the nut 7 are formed from steel. The ring member 8 is formed from a synthetic resin.

  According to 1st Embodiment which has said structure, since the female thread cutting of the ring member 8 is performed between the screw shaft 5 and the nut 7, it will be in a fastening state after female thread cutting is forced. . An axial force for screwing the inner ring 4 or the like in the axial direction is secured between the screw shaft 5 and the nut 7. At this time, the internal thread 8 a that is forcibly formed on the ring member 8 is in strong elastic contact with the external thread 5 a of the screw shaft 5. For this reason, the friction torque that resists the return rotation of the nut 7 increases over a plurality of pitches, and the nut is a torque derived from vibration, external force, and rotational inertial force associated with the operation of the shaft system such as the rotary shaft 2 and the bearing 3. 7 is more reliably prevented from returning and rotating. Therefore, according to the first embodiment, it is possible to reliably prevent the fixed slack of the inner ring 4 and the like.

  In the first embodiment, the ring member 8 can also be formed of a metal that is softer than the material of the male screw 5a and that suppresses adhesion to the male screw 5a. Since the male screw 5a is made of steel, for example, the ring member 8 can be made of soft metal such as gun metal or brass which is softer than steel and has different main components. Thereby, while preventing the external thread 5a from being damaged, seizure of the internal thread 8a and the external thread 5a of the ring member 8 is prevented. Further, while the nut 7 is prevented from loosening due to the friction of the ring member 8, it is possible to avoid strong tightening of the nut 7 and the screw shaft 5 formed of the same kind of metal, and to prevent these seizures.

A second embodiment of the present invention will be described with reference to FIG. In the following, only the differences from the first embodiment will be described.
As illustrated, the screw fastening device for a bearing member according to the second embodiment is provided with a screw shaft 14 at one end in the axial direction of a pin 13 inserted into the annular body 11 and the hollow roller 12 of the pin type cage. Yes. The other axial end of the pin 13 is fixed to another annular body 15. The screw shaft 14 passes through a tapered hole 11a that passes through the annular body 11 in the axial direction. A taper bush 16 passed through the screw shaft 14 is press-fitted into the inner periphery of the taper hole 11a, and a nut 17 is screwed into the screw shaft 14, whereby the taper bush 16 is tightened into the annular body 11, and the pin 13 and the taper are tapered. The bush 16 and the annular body 11 are fastened.
According to the second embodiment, even if the rotation direction of the pin type retainer coincides with the return rotation direction of the nut 17, the pin 13 can prevent the above-mentioned loosening by the ring member 18 provided on the inner periphery of the nut 17. Therefore, it is possible to prevent the loosening of the annular body 11 from being fixed.

The principal part longitudinal section front view which shows the whole structure of the screw fastening apparatus for bearing members which concerns on 1st Embodiment. a is a half longitudinal front view showing a state before use of the nut of FIG. 1, and b is a partial half longitudinal front view showing the nut being tightened in FIG. a is the principal part expansion side view which shows the axial direction one end side of the screw fastening apparatus for bearing members which concerns on 2nd Embodiment, b is the principal part longitudinal cross-sectional front view of the fastening apparatus of said a.

Explanation of symbols

2 Rotating shaft 3 Bearing 4 Inner ring 5, 14 Screw shaft 5a Male screw 6 Sleeve 7, 17 Nut 7a, 8a Female screw 7b Recessed portion 7c Caulking portion 8, 18 Ring member 11, 15 Annular body 12 Hollow roller 13 Pin 16 Taper bush

Claims (5)

  A screw shaft and a nut for fastening the bearing member are provided, a recess that is larger than the inner diameter of the female screw is formed on the inner periphery of the nut, a ring member fitted in the recess is fixed, and the nut and the screw shaft are screwed together In a screw fastening device for a bearing member in which the ring member is elastically contacted with a male screw to increase a friction torque that resists the return rotation of the nut, the ring member is fastened by the male screw while the screw shaft is fastened with the nut. A screw fastening device for a bearing member, wherein a plurality of pitches of female threads are performed, and the friction torque is increased at a threaded portion of the ring member and the male screw.   The screw fastening device for a bearing member according to claim 1, wherein the ring member is formed of a resin or metal that is softer than a material of the male screw.   The screw fastening device for a bearing member according to claim 2, wherein the male screw of the screw shaft is made of metal, and the ring member is made of metal that prevents adhesion with the male screw.   The screw fastening device for a bearing member according to any one of claims 1 to 3, wherein the screw shaft is provided at one axial end portion of a rotating shaft supported by the bearing.   The screw fastening device for a bearing member according to any one of claims 1 to 3, wherein the screw shaft is provided at one end in an axial direction of a pin that is inserted into an annular body and a hollow roller of a pin type cage.

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