JP2006234097A - Creep prevention device and rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an elastic body from being damaged when the elastic body is installed in a housing without causing the lowering of a creep prevention performance. <P>SOLUTION: In this creep prevention device, the elastic body of a circular shape in cross section having a radius r is assembled in an elastic body groove, and the depth of the elastic body groove is equal to or deeper than the radius r of the elastic body. The elastic body groove has a width B fulfilling the requirement of a numerical expression 1 to prevent the elastic body from being damaged when it is assembled in the housing. In the numerical expression 2r<B<4r. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a creep preventing device having a creep preventing function, and a rolling bearing, which are applied to uses such as general-purpose motors, geared motors, fan motors, servo motors, electric tools, sewing machines, etc. in which an unbalanced rotational load acts on the device. About.

  Conventionally, as an anti-creep device, for example, a rolling bearing for the purpose of preventing creep is disclosed in Patent Document 1.

  The configuration is such that a concave groove is formed on the outer diameter surface of the outer ring of the rolling bearing and an O-ring having a hardness of Hs 60 to 75 is fitted into the concave groove. This is 4 to 40% of the cross-sectional diameter of the O-ring.

  Generally, the O-ring groove width is set to about 1.1 to 1.4 times the O-ring cross-sectional diameter.

  Also, if damage occurs during assembly, the resistance between the housing and the O-ring is lowered, so that the amount of protrusion cannot be increased, and the creep prevention function after attachment may be reduced.

  FIG. 2 is a half sectional view of a general creep prevention device and a rolling bearing with an O-ring.

  In the rolling bearing 1 with an O-ring, a ball 4 as a rolling element is interposed between an inner ring 2 and an outer ring 3 so as to freely roll, and the balls 4 are maintained at a predetermined interval by a cage 5. A seal (shield) 6 is attached to the inner diameter side of the outer ring 3, and a predetermined gap is set between the outer ring 3 and the outer ring side.

A concave groove 10 is formed on the outer peripheral surface of the outer ring 3, and an O-ring 11 as an elastic body is fitted in the concave groove 10.
JP 2002-130309 A

  However, according to the prior art, when an elastic body having a circular cross section is attached to the housing, the elastic body protrudes from the outer surface of the creep prevention.

  As a result, depending on the shape of the housing, the friction between the elastic body protruding portion and the housing increases, and the attachment is hindered, so that a large force is applied and there is a problem that the elastic body is damaged when pushed.

  The present invention has been made in view of the circumstances as described above, and can prevent damage to an elastic body when attached to a housing without causing deterioration in creep prevention performance. An object is to provide a rolling bearing.

但し、
２ｒ＜Ｂ＜４ｒ
であることを特徴とする。 In order to achieve the above object, an anti-creep device according to claim 1 of the present invention comprises:
An elastic body having a circular cross section of radius (r) is incorporated into the elastic body groove,
The elastic body groove is an anti-creep device having an elastic body groove depth equal to or larger than the radius (r) of the elastic body.
The elastic groove has an elastic groove width (B) that satisfies the following formula so as not to be damaged when the housing is assembled.

However,
2r <B <4r
It is characterized by being.

The rolling bearing according to claim 2 of the present invention is a rolling bearing in which a rolling element is interposed between an inner ring and an outer ring so as to freely roll.
The creep prevention device according to claim 1 is provided.

  According to the present invention, in an anti-creep device equipped with an elastic body having a circular cross section protruding from a concave groove, for example, a rolling bearing with an O-ring, the elastic groove width with respect to the elastic body cross-sectional diameter is optimally set. Without damaging the creep prevention performance, it is possible to prevent the elastic body from being damaged when attached to the housing.

に設定されていることから、クリープ防止性能の低下を起こすことなしに、ハウジングに取り付ける際の弾性体の破損を防止するごとが出来る。 That is, the elastic groove width having a circular cross section is:

Therefore, it is possible to prevent breakage of the elastic body when it is attached to the housing without causing deterioration of the creep prevention performance.

  In addition, an elastic body, an elastic body groove | channel, a housing, and a code | symbol are as showing in a reference figure and FIG. FIG. 1 is a schematic cross-sectional view of an elastic body, an elastic body groove, and a housing in a creep preventing apparatus according to the present invention.

Further, in the bearing, since there is a limitation due to the width and chamfering of the bearing, the elastic groove width (B) cannot be increased. The range of (d) in which the creep preventing effect is obtained and the present invention can be applied is as follows:
r <d <2r
It is. Therefore, the elastic body groove width (B) is
2r <B <4r
It becomes.

  Hereinafter, a creep prevention device and a rolling bearing according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an elastic body, an elastic body groove, and a housing in a creep preventing apparatus according to the present invention.

したがって、クリープ防止性能の低下を起こすことなしに、ハウジングに取り付ける際の弾性体の破損を防止するごとが出来る。 An elastic body having a circular cross section with a radius (r) is incorporated into the elastic body groove, and the elastic body groove is an anti-creep device having an elastic body groove depth equal to or greater than the radius (r) of the elastic body. In order to prevent damage when the housing is assembled, the elastic body has a groove width (B) that satisfies the following formula.

Therefore, it is possible to prevent the elastic body from being damaged when it is attached to the housing without causing deterioration in the creep prevention performance.

In the bearing, the elastic groove width (B) cannot be increased because the bearing width and chamfering are limited. The range of (d) in which the creep preventing effect is obtained and the present invention can be applied is as follows:
r <d <2r
It is. Therefore, the elastic body groove width (B) is
2r <B <4r
It becomes.

  FIG. 2 is a half sectional view of a general creep prevention device and a rolling bearing with an O-ring.

  In the rolling bearing 1 with an O-ring, a ball 4 as a rolling element is interposed between an inner ring 2 and an outer ring 3 so as to freely roll, and the balls 4 are maintained at a predetermined interval by a cage 5. A seal (shield) 6 is attached to the inner diameter side of the outer ring 3, and a predetermined gap is set between the outer ring 3 and the outer ring side.

  A concave groove 10 is formed on the outer peripheral surface of the outer ring 3, and an O-ring 11 as an elastic body is fitted in the concave groove 10.

  Next, an example of a damaged form of the elastic body having a circular cross section is shown in FIG. 3 and will be described below. 3 (a) and 3 (b) each show a damaged form of the elastic body, (a) shows a general elastic body groove width, and (b) shows a case where the elastic body groove width is widened. .

  As the housing shape, a general shape that is most easily damaged by the elastic body is used.

  As shown in FIG. 3A, when the anti-creep device is installed, the corner of the housing first comes into contact with the outer surface of the elastic body having a circular cross section.

  When the housing pushes above the elastic body, the elastic body starts to rotate due to friction between the elastic body and the elastic body groove.

  If the groove of the elastic body is narrow at this time, the elastic body hits the side surface of the elastic body groove before the housing corners are sufficiently covered with the elastic body, and the elastic body cannot rotate due to friction with the side surface. May cause the elastic body to be bitten and the elastic body to be damaged.

  Note that if the housing moves further than the rightmost diagram in FIG. 3A, a part of the elastic body may be damaged.

  As shown at the right end of FIG. 3B, the housing passes over the elastic body before being subjected to the frictional resistance by the elastic body groove, and therefore is not damaged.

  Therefore, if the elastic body is accommodated in the housing before hitting the side surface, the elastic body cannot protrude from the inner diameter of the housing, and the above-described damage does not occur.

  Therefore, it is possible to prevent the elastic body from being damaged at the time of insertion by calculating and optimizing the elastic body groove width necessary for the elastic body to roll and push the elastic body until the elastic body fits in the housing.

<Effective width calculation method>
FIG. 4A shows the meaning of symbols used in each description and a schematic diagram of the elastic groove width (B), and FIG. 4B shows supplements thereof. In the supplement of FIG. 4B, when the circle rolls on the plane, if the center advances N times, the object on the point B moves 2N, which is the sum of the movement distances of the points A and B.

To be incorporated without damaging the elastic body,
B ≧ b1 + b20 + b3
is required.
b1: radius of the elastic body in the initial state b2: distance of the elastic body moved until the housing reaches half of the elastic body b3: long radius of the ellipse when the housing reaches the center of the elastic body (1) b1 calculation b1 = r
r: Calculation of radius (2) b2 of elastic body The elastic body is deformed while being pushed and rotated by the housing, and is finally in a completely integrated state.

  At this time, to calculate the moving distance of the elastic body, the elastic body rolls while deforming, so it is necessary to perform a very complicated calculation, but the housing is at the apex (center) of the elastic body during actual installation. Until it comes, the rolling surface is almost in the shape of the circle in the initial state.

  Therefore, the moving distance that the elastic body rolls can be approximated to the distance that the elastic body having the radius r in the initial state rolls and moves as a rigid body.

  Therefore, the distance that the housing moves to move to the top of the elastic body after contacting the elastic body is twice the distance from the current housing to the top of the elastic body.

The distance L required for the housing to move to the top of the elastic body (center) is

(3) Calculation of b3 The actual shape of the elastic body until the housing reaches the position of the apex of the elastic body has a shape close to a state in which a part of the circle is recessed as shown in FIG. It is well known that the housing becomes closer to an elliptical shape when it exceeds half of the elastic body.

In calculating the elastic groove width that satisfies the conditions of the present invention, the final shape should be an ellipse and half of the major radius should be b3. Therefore, the area is constant before and after deformation,

となる。
但し、
２ｒ＜Ｂ＜４ｒ
である。 In addition, the smaller the inner diameter of the housing, the longer the distance that the elastic body rolls, and the elastic body groove width is also required. Therefore, the condition that the elastic body groove width becomes the largest is when the housing inner diameter = the outer diameter of the creep preventing device, that is, 2a = d. Therefore, the above formula is

It becomes.
However,
2r <B <4r
It is.

  FIG. 5 is a graph showing a comparison between the result of a damage experiment performed by changing the elastic groove width while keeping the elastic body constant, and the calculated elastic groove width.

  As a result, according to the damage experiment result, it was an experiment result (FIG. 5) that prevents the elastic body from being damaged by increasing the elastic body groove width beyond a certain level. Further, when the elastic groove width calculated from [Equation 1] is superimposed on the fracture experiment result, the effectiveness of this equation can be confirmed.

  In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible.

It is typical sectional drawing of the elastic body in the creep prevention apparatus which concerns on this invention, an elastic body groove | channel, and a housing. It is a half sectional view of a general creep prevention device and a rolling bearing with an O-ring. (A) and (b) each show the damage form of an elastic body, (a) shows a general elastic body groove width, (b) shows the case where the elastic body groove width is expanded. (A) shows the meaning of the symbol used for each description, and the schematic of elastic body groove width (B), (b) shows the supplement. It is a graph which compares and shows the damage experiment result performed by making an elastic body constant and changing an elastic body groove width, and the calculated elastic body groove width.

Explanation of symbols

1 Rolling bearing with O-ring 1
2 Inner ring 3 Outer ring 4 Ball 5 Cage 6 Seal (shield)
10 groove 10
11 O-ring (elastic body)

Claims (2)

An elastic body having a circular cross section of radius (r) is incorporated into the elastic body groove,
The elastic body groove is an anti-creep device having an elastic body groove depth equal to or larger than the radius (r) of the elastic body.
The elastic groove has an elastic groove width (B) that satisfies the following formula so as not to be damaged when the housing is assembled.

However,
2r <B <4r
Anti-creep device characterized by being. In a rolling bearing in which a rolling element is interposed between an inner ring and an outer ring so as to freely roll,
A rolling bearing comprising the creep prevention device according to claim 1.

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