JP3332049B2 - Crowned cage for ball bearings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crown type cage for a ball bearing, and more particularly, the whole is formed of a highly brittle material such as graphite, or a hard material such as stainless steel SUS304. The present invention relates to a crown type cage for a ball bearing.

[0002]

2. Description of the Related Art For example, a heat-resistant ball bearing provided with a ceramic inner and outer ring and a ball used in a high-temperature atmosphere (about 400 to 500 ° C.) such as a heat treatment furnace. In order to ensure lubricity, a crown retainer made of graphite, which is a solid lubricant, is used. Conventionally, as shown in FIG. 3, a crown-shaped retainer 90 made of a material having high brittleness such as graphite or a hard material such as stainless steel SUS304 generally has a maximum inner diameter of a pocket 91 and a ball hole. A so-called milling die having the same opening width as the above is used.

With this type of cage 90, as shown in FIG. 4, it is not necessary to forcibly push the ball B1 into the pocket 91 when assembling it into the ball bearing B, so that a brittle material such as graphite, Or stainless steel SUS30
Even if the whole is made of a hard material such as 4, there is no risk of cracking, chipping, cracking, etc., or damaging the ball B1.

[0004] However, the above-mentioned machined-type retainer 90 is liable to fall off when the ball bearing B rotates or the like.
It is necessary to attach a ring-shaped drop-prevention plate P as shown in the figure, which causes problems such as an increase in the number of parts and a complicated structure of a ball bearing mounting portion of a member into which the ball bearing B is incorporated. As shown in FIG. 5, the applicant of the present application has previously described a case in which the opening width W of the cutout portion 92 for inserting a ball of the graphite retainer 90 is made smaller than the diameter D of the ball B1 of the ball bearing B. In order to prevent cracks and the like from occurring in the retainer 90, the range of the opening width W should be considered. Then, the following equation (1)

[0005]

(Equation 1)

[0006] The aperture ratio R (%) represented by
It has been found that if the opening width W of the cutout portion 92 is set so as to be 9%, there is no risk of cracking or the like when the ball B1 is inserted (Japanese Patent Laid-Open No. 1-126426). However, at such an opening ratio, when an excessive moment load is applied to the ball bearing B due to vibration or the like, or when the opening of the notch portion 92 becomes large due to wear, etc., the ball bearing B is moved from the ball bearing B to the cage 91. May fall off.

To further reduce the opening ratio R (%) in order to more reliably prevent the retainer from falling off, the retainer may be cracked when the ball is inserted, or the ball may be damaged. It is necessary to devise some measure to prevent the occurrence of the above problem. As an example, it has been considered to divert the configuration of the plastic cage disclosed in Japanese Utility Model Laid-Open No. 53-62553.
As shown in FIG. 6, the retainer 94 disclosed in the above publication has a slit 97 formed in the center between the pockets 95 along the axial direction from the side where the pocket 95 is opened by the notch 96. It is.

In the retainer 94 having this configuration, the ball B1
Is inserted into the pocket 95, the slit 97 absorbs the deformation of the portions 94a on both sides of the notch 96, so that the opening ratio R (%) of the notch 96 represented by the above-mentioned formula (1) is set to Even if it is made smaller, the occurrence of cracks or the like in the retainer 94 when the ball is fitted, and the damage to the ball are reduced. For this reason, there is a possibility that the opening width W of the cutout portion 96 is made smaller than in the related art, so that the retainer 94 can be more reliably prevented from falling off from the ball bearing.

However, in the cage 94, since the slit 97 is formed only in the middle of the pocket 95, when it is made of a material such as graphite having high brittleness,
The distance d between the bottom of the slit 97 serving as a fulcrum of the deformation when the ball B1 is inserted and the pocket 95 is short, and the cross-sectional area of this portion is reduced. And the like may occur.

The present invention has been made in view of the above circumstances, and there is no risk that the ball will be damaged or damaged when the ball is inserted, and that the ball will not easily fall off when incorporated into a ball bearing. It is an object of the present invention to provide a crown type cage for a bearing.

[0011]

According to the present invention, there is provided a crown type retainer for a ball bearing according to the present invention, which comprises a plurality of outer peripheral surfaces and an inner peripheral surface for holding a ball of a ball bearing in an annular main body. Penetrate into
And with the cylindrical pocket is located, each pocket has been opened in one end face of the body by a notch Gras
In the ball bearing cage retainer made of fight, in the center between the pockets of the main body, a slit extending from one end surface of the opened pocket to substantially the same depth as the bottom of the pocket along the axial direction , From the bottom to the slit bottom
When the distance is larger slit than the diameter of the ball Ru formed
In both cases, the opening width of the notch in each pocket fits into the pocket.
It is characterized in that it is 95 to 98% of the ball diameter to be inserted .

[0012]

In the crown type cage for a ball bearing of the present invention having the above structure, as shown in FIG. 1 (b), the slits 4 formed between the pockets 3 have the same depth as the bottom of the pockets 3. The distance d between the bottom of the slit 4 and the pocket 3 which is the fulcrum of deformation when the ball B1 is inserted is farther than that of FIG. Is big. Thus, particularly high brittle Graphite
The slit 4 deforms both sides of the notch 2 when the ball B1 is inserted into the pocket 3 without forming a crack or the like in the above-described portion while forming the ball bearing retainer 1 for the ball bearing. Can be reliably absorbed.

[0013] Thus, according to the configuration of the present invention, the whole <br/> Graphite ball crown type cage bearing formed in order to more reliably prevent the falling off of the cage from a ball bearing, the Even if the opening ratio R (%) of the notch portion represented by the formula (1) is made smaller than before, it is possible to prevent the retainer from being cracked or the like and the ball from being damaged when the ball is fitted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A crown type cage for a ball bearing according to the present invention will be described below with reference to FIGS. 1 (a) and 1 (b) showing an embodiment thereof. As shown in these figures, the ball bearing retainer 1 of this embodiment
Forms a plurality of pockets 3 opened by the cutouts 2 on one end face 10a side of the annular main body 10,
A slit 4 extending in the axial direction from the one end face 10a is formed at a central portion between the pockets 3.

As is apparent from the above-described operation of the present invention, the main body 10 is preferably made of a highly brittle material such as graphite or a hard material such as stainless steel SUS304. However, the cage may be formed of another material that is generally used as a material of the cage. The notch 2 has an opening width W of the ball B1 as described above.
Is formed to be smaller than the diameter D. From the opening width W and the diameter D, the opening ratio R (%) of the notch 2 obtained by the above equation (1) is not particularly limited.
The preferred range differs depending on the material constituting the material.

For example, when the main body 10 is made of graphite, the opening ratio R (%) is 95 to 98.
%, More preferably 96 to 98%. If the opening ratio R (%) is less than 95%, when the ball B1 is inserted into the pocket 3, the cage 1 may be cracked. When the opening ratio R (%) exceeds 98%, when the ball bearing B is installed in the ball bearing B when a moment load such as vibration is applied, or when the ball bearing B is worn, the notch 2 becomes large due to wear. When the cage 1 becomes a ball bearing B
May easily fall off.

The slit 4 is formed to extend from one end face 10a of the main body 10 to a depth substantially equal to the bottom of the pocket 3 along the axial direction. If the slit 4 is not formed to reach the same depth as the bottom of the pocket 3, as described above, when the ball bearing crown type retainer 1 is formed of a material such as graphite having high brittleness. To
There is a possibility that a crack or the like may occur at a portion where the distance between the bottom of the slit 4 and the pocket 3, which is a fulcrum of deformation when the ball B1 is fitted, and the pocket 3 is closest.

Conversely, if the slit 4 is formed deeper than the bottom of the pocket 3, the distance between the bottom of the slit 4 and the end face 10b on the opposite side of the main body 10 becomes too short, so that the ball B1 There is a possibility that a crack or the like may be generated at this portion when fitting. The shape of the bottom of the slit 4 is
A circle is preferable as shown in the figure. If there is a corner at the bottom of the slit 4, for example, when the ball B1 is inserted into a pocket,
Stress may be concentrated on the corners, and the cage 1 may be cracked therefrom. An elliptical shape other than a circular shape is also suitable as the shape of the bottom of the slit 4.

As shown in FIG. 2, for example, the crown type cage 1 for a ball bearing having the above-described structure has a plurality of balls B1 rotatably interposed between the inner and outer races B2 and B3. did,
Used by being incorporated into the deep groove ball bearing B. When incorporating the ball bearing crown type retainer 1 into the ball bearing B as shown in the figure, a slit 4 formed between the pockets 3 and having a depth substantially equal to the depth of the bottom of the pocket 3 is formed. The deformation of the portions on both sides of the cutout portion 2 when the ball B1 is fitted into the pocket 3 is reliably absorbed without causing cracks or the like. For this reason, in particular, in the crown type retainer 1 for a ball bearing made of a highly brittle material, a hard material, or the like, in order to more reliably prevent the ball bearing B from falling off, the above formula ( 1)
Even if the opening ratio R (%) of the notch 2 obtained in the step (1) is made sufficiently smaller than before, it is possible to prevent the ball B1 from being cracked or the like and the ball B from being damaged when fitted.

The crown type cage 1 for a ball bearing according to the embodiment incorporated in the ball bearing B is formed so that the opening ratio R (%) of the notch 2 is sufficiently small as described above. , Ball bearing B without mounting the fall prevention plate P
There is no danger of easily falling off. For this reason, an increase in the number of parts or a member incorporating the ball bearing B,
There is no problem such as complication of the structure of the ball bearing mounting portion.

The configuration of the present invention is not limited to the above-described embodiment, and design changes can be made as appropriate without departing from the gist of the present invention.

[0022]

As described in detail above, according to the present invention,
A slit is formed at a central portion between the pockets of the retainer along the axial direction to a depth substantially equal to the bottom of the pocket, and a distance from the bottom to the bottom of the slit is equal to a diameter of the ball.
Since it is larger than the diameter, it is possible to prevent the retainer from being cracked or the like when the ball is fitted, or the ball from being damaged. Therefore, according to the configuration of the present invention, the entire crown type cage for a ball bearing, while also formed of Graphite, the opening ratio of the cut-out portion is made smaller than the conventional, more falling off from the ball bearing cage It is possible to reliably prevent it.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing one embodiment of a crown type retainer for a ball bearing of the present invention, and FIG. 1 (b) is a sectional view taken along line bb of FIG. 1 (a).

FIG. 2 is a cross-sectional view showing a state where the crown type retainer for a ball bearing of FIG. 1 is incorporated in a ball bearing.

FIG. 3 is a perspective view showing an example of a conventional machined-type retainer.

FIG. 4 is a cross-sectional view showing a state where the above-described machined-type cage is assembled in a ball bearing.

FIG. 5 is a perspective view showing a conventional example in which an opening width of a cutout portion of a pocket is smaller than a diameter of a ball.

FIG. 6 is a partially enlarged side view showing a conventional example in which a shallow slit is provided between pockets.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Ball bearing crown type retainer 10 Main body 10a One end surface 2 Notch 3 Pocket 4 Slit B Ball bearing B1 Ball D Ball diameter W Width of cutout

Continuation of the front page (56) References JP-A-1-126426 (JP, A) JP-A-2-132125 (JP, U) JP-A-2-87121 (JP, U) (58) Fields surveyed (Int) .Cl. ⁷ , DB name) F16C 19/00-19/56 F16C 33/30-33/66

Claims (1)

(57) [Claims] A plurality of cylindrical pockets for holding a ball of a ball bearing penetrating from an outer peripheral surface to an inner peripheral surface are arranged in an annular main body, and each pocket is formed by a cut-out portion. In a crown type retainer for a graphite ball bearing opened on the end face side, in the central portion between the pockets of the main body, from one end face where the pocket is opened, along the axial direction to approximately the same depth as the bottom of the pocket. The slit that reaches
The distance from the bottom to the slit bottom is greater than the diameter of the ball
Larger slits are formed Rutotomoni, each pocket
The opening width of the notch is 95% of the diameter of the ball to be inserted into the pocket.
Crowned cage for ball bearings up to 98% .