JP2009228857A - Crown cage and ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crown cage capable of reducing indentation force required to push a ball into a pocket. <P>SOLUTION: A plurality of pockets 7a and 7b which is opened on one side in an axis direction is formed in a circumferential direction to retain a plurality of balls 3 of a ball bearing so as to be freely rolled. When the plurality of balls 3 is passed through the gap of the opening end of the pockets 7a and 7b in the axis direction and pushed into the pockets 7a and 7b, the gap of the opening end is elastically flared by the balls 3. The opening end of at least one pocket 7a is different in a position in the axis direction from the opening end of another pocket 7b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a crown type cage and a ball bearing provided with the crown type cage.

As a general ball bearing, an outer ring, an inner ring, a plurality of balls that roll on the outer raceway surface of the outer ring and an inner raceway surface of the inner ring, and a synthetic resin that holds these balls as rollable Some have a crown type cage (hereinafter also referred to as a cage). In the cage, a plurality of pockets are formed at equal intervals in the circumferential direction in order to hold a plurality of balls (see, for example, Patent Document 1).
FIG. 6A is an enlarged view of a pocket portion of a conventional cage. The pocket 42 formed in the annular retainer 41 is open on one side in the axial direction (the upper side in FIG. 6A), and the ball 43 is pushed into the pocket 42 from the one side. Therefore, the ball 43 is accommodated in the pocket 42.
Since the dimension between the open ends 44 and 44 of the pocket 42 is smaller than the diameter D of the ball 43, when the ball 43 is pushed into the pocket 42, the space between the open ends 44 and 44 is elastically expanded. It passes between the open ends 44a and 44b.

JP 2001-227546 A (see FIG. 3)

The shapes of the plurality of pockets 42 formed in the conventional cage 41 are all the same, and the positions of the opening ends 44 of the pocket 42 in the axial direction are all the same. That is, in FIG. 6A, the axial dimension h from the bottom 45 of the pocket 42 to the open ends 44, 44 is the same for all the pockets 42.
Therefore, when all the balls 43 are pushed into the pockets 42 at the same time, the space between the open ends 44a and 44b of all the pockets 42 is simultaneously elastically expanded, so that a large resistance acts on the balls 43. Therefore, in order to accommodate the ball 43 in the pocket 42, it is necessary to resist this resistance force. As shown in FIG. 6B, a large pushing force (incorporating force) against the ball 43 at once. P needs to be given. For this reason, the operation | work which attaches a ball | bowl to a crown shape holder may become difficult.
Accordingly, an object of the present invention is to provide a crown type cage that can reduce the pushing force required to push the ball into the pocket, and a ball bearing including the crown type cage.

  In order to achieve the above object, a crown type cage of the present invention is a crown in which a plurality of pockets opened in one axial direction are formed in the circumferential direction so as to hold a plurality of balls of a ball bearing in a freely rolling manner. In the mold holder, the open end of at least one of the plurality of pockets is different in position in the axial direction from the open end of another pocket.

  According to this crown type cage, since the opening end of at least one of the plurality of pockets is different from the opening end of the other pocket in the axial direction, When pushing into a plurality of pockets, the timing to elastically push between the open ends by passing the balls can be different between at least one pocket and the other pocket. For this reason, in order to push a plurality of balls into the pocket, it is possible to disperse the pushing force that needs to be applied to the balls over time, and the necessary pushing force can be made smaller than before.

Further, the inner wall surface of the one pocket has a first spherical portion on the bottom side and a second spherical portion on the opening end side formed in a spherical shape centering on two different points in the axial direction, and a space between these spherical portions. It is preferable to have an intermediate portion extending in the axial direction.
According to this, the structure which becomes the position which shifted the opening end of the said one pocket to the one side of the axial direction rather than the opening end of the other pocket by the intermediate part can be obtained easily.

Moreover, it is preferable that the plurality of pockets are alternately different in the circumferential direction with respect to the axial position of the opening end.
According to this, when pushing all balls into all pockets, by pushing these balls linearly along the axial direction, some of the balls are pushed into the pockets first, The remaining balls can then be pushed into the remaining pockets. Thus, the pushing force that needs to be applied to the balls to push all the balls into the pockets can be dispersed over time, and the necessary pushing force can be made smaller than before.

In the crown-shaped cage, the dimension between the open ends of the one pocket and the dimension between the open ends of the other pockets are preferably the same.
According to this, the holding force which suppresses that the ball | bowl accommodated in the pocket tries to pull out from an opening end can be made the same.

The ball bearing of the present invention includes an outer ring, an inner ring, an outer raceway surface formed on the outer ring, a plurality of balls that roll on the inner raceway surface formed on the inner ring, and the crown type cage. It is provided.
According to this ball bearing, since the crown-shaped cage is provided, in manufacturing the ball bearing, in order to push a plurality of balls into the pocket of the crown-shaped cage, the pushing force that needs to be applied to the ball Can be dispersed over time, and the required pushing force can be made smaller than in the prior art.

  According to the present invention, when the ball of the ball bearing is pushed into the pocket, the timing at which the opening end spreads by the passage of the ball can be made different between at least one pocket and the other pocket. In order to push the ball into the pocket, the pushing force required to be applied to the ball can be dispersed over time, and the necessary pushing force can be made smaller than before. As a result, the work of attaching the ball to the crown-shaped cage is facilitated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of the ball bearing of the present invention. The ball bearing includes an outer ring 1, an inner ring 2 provided concentrically with the outer ring 1, a plurality of balls 3 provided between the outer ring 1 and the inner ring 2, and a plurality of balls 3 arranged at a predetermined interval ( And a crown-shaped cage 4 (hereinafter referred to as cage 4) that is held at equal intervals.
An outer raceway surface 11 is formed on the inner circumference surface of the outer ring 1, an inner raceway surface 12 is formed on the outer circumference surface of the inner ring 2, and the plurality of balls 3 roll on the outer raceway surface 11 and the inner raceway surface 12. Move. And the holder | retainer 4 is hold | maintaining these balls 3 as rolling freely. All the balls 3 are the same (the diameter is the same).

FIG. 2 is a perspective view of the cage 4. As shown in FIGS. 1 and 2, the retainer 4 is formed with a plurality of pockets 7a and 7b in the circumferential direction for holding a plurality of balls 3 in a rollable manner. It opens to one side of the direction (left side in FIGS. 1 and 2). The overall shape of the cage 4 is annular, and is configured as a so-called crown shape. The cage 4 is made of synthetic resin. For this reason, when each of the plurality of balls 3 is pushed between the opening ends of the pockets 7a and 7b in the axial direction and pushed into the pockets 7a and 7b, the balls 3 elastically move between the opening ends. It is pushed out.
The cage 4 has an annular base 6 and a main body 8. The main body 8 is a portion where pockets 7a and 7b are formed, and the base 6 is on the other side in the axial direction of the plurality of balls 3 provided between the outer ring 1 and the inner ring 2 (in FIG. 1). It is the part arranged on the right side).

  The cage 4 shown in FIG. 2 is formed with concave pockets at 10 locations in the circumferential direction. The cage 4 has two types of pockets (first pocket 7a and second pocket 7b). Is formed. The main body portion 8 of the cage 4 has a plurality of column portions 14 in the circumferential direction. The column portion 14 protrudes from the annular base portion 6 to one side in the axial direction (left side in FIG. 2). And between the adjacent pillar parts 14 and 14 becomes a pocket. That is, the column part 14 is provided between the adjacent pockets 7a and 7b.

3 and 4 are sectional views of the first pocket 7a and the second pocket 7b. 3 and 4, the ball 3 is indicated by a two-dot chain line as a state before the ball 3 is accommodated in the pockets 7a and 7b.
The first pocket 7a will be described. A claw portion 17a is further provided on one side (upper side in FIG. 3) of the column portion 14a described at the left end of FIG. 3 so as to protrude to the one side, and the circumferential direction of the column portion 14a Similarly, the claw portion 17a is also provided in the column portion 14b adjacent (right adjacent in FIG. 3). These claw portions 17a and 17a are provided to face each other, and the pair of claw portions 17a and 17a prevent the balls 3 arranged in the first pocket 7a from coming out. The tip portions on the inner peripheral side of the claw portions 17a and 17a become the open ends 10a and 10a of the first pocket 7a.

  The inner wall surface 9a of the first pocket 7a includes a spherical portion 20 formed on a spherical surface with a single point C0 as a central point. The spherical portion 20 has a shape along a spherical surface having a radius of curvature slightly larger than the radius of curvature of the ball 3. The one point (center point) C0 of the first pocket 7a coincides with the center point of the ball 3 accommodated in the first pocket 7a as being rollable. The spherical surface portion 20 (inner wall surface 9a) is a portion formed from the bottom portion 13a to the pair of opening ends 10a, 10a. As shown in FIG. The shape is along a single circle (arc) centered on one point (center point) C0.

The second pocket 7b will be described. A claw portion 17b is further provided on one side (upper side in FIG. 3) of the column portion 14b so as to protrude to the one side, and is adjacent in the circumferential direction of the column portion 14b (right side in FIG. 3). Similarly, the claw portion 17b is provided in the column portion 14c. These claw portions 17b and 17b are provided to face each other, and the claw portions 17b and 17b as a pair prevent the balls 3 arranged in the second pocket 7b from coming out. The tip portions on the inner peripheral side of the claw portions 17b and 17b become the opening ends 10b and 10b of the second pocket 7b.
As shown in FIG. 3, the axial position of the claw portions 17a and 17a of the first pocket 7a and the axial position of the claw portions 17b and 17b of the second pocket 7b are in the second pocket 7b. It differs depending on the provided intermediate portions 23 and 23 (described later).

The inner wall surface 9b of the second pocket 7b has a first spherical surface portion 21 on the bottom portion 13b side formed in a spherical surface with one point C1 as a central point, and the opening ends 10b and 10b side formed in a spherical surface with another point C2 as a central point. Second spherical surface portions 22 and 22 and intermediate portions 23 and 23 that extend in the axial direction between the first spherical surface portion 21 and the second spherical surface portions 22 and 22. .
The two points C1 and C2 are axially different points, one point (center point) C1 is located on the bottom 13b side of the second pocket 7b, and the other point (center point) C2 is It is located closer to the open ends 10b and 10b than the one point C1.
The first spherical surface portion 21 and the second spherical surface portion 22 of the second pocket 7b are shaped along a spherical surface having a curvature radius slightly larger than the curvature radius of the ball 3, and are the same as the spherical surface portion 20 of the first pocket 7a. Has a radius of curvature.

The intermediate portions 23, 23 are opposed to each other with a larger interval than the diameter D of the ball 3. The intermediate portions 23, 23 have a shape along a cylindrical surface with a straight line connecting the points C 1 and C 2 as a center line, and the radius thereof is slightly larger than the radius of curvature of the ball 3. In FIG. 4, the dimension in the axial direction of the intermediate portions 23, 23 is indicated by α.
The inner wall surface 9b of the second pocket 7b is a portion formed from the bottom portion 13b to the pair of opening ends 10b, 10b through the pair of intermediate portions 23, 23, as shown in FIGS. Moreover, the cross-sectional shape of the inner wall surface 9b is a shape along an oval that is long in the axial direction.
The positions of the bottom 13a of the first pocket 7a and the bottom 13b of the second pocket 7b in the axial direction are the same.

  As described above, the second pocket 7b is different in shape from the first pocket 7a in that it has the intermediate portions 23 and 23. Due to the intermediate portions 23, 23, the opening ends 10b, 10b of the second pocket 7b are different from the opening ends 10a, 10a of the first pocket 7a in the axial direction. That is, in FIG. 4, the opening ends 10 b and 10 b of the second pocket 7 b are one side in the axial direction with respect to the axial dimension α of the intermediate portions 23 and 23 relative to the opening ends 10 a and 10 a of the first pocket 7 a ( The axial dimension (depth) H2 of the second pocket 7b is larger than the axial dimension (depth) H1 of the first pocket 7a by the dimension α. (H2-α = H1). 2 and 4, the first pocket 7a has the same axial dimension H1 as the other first pockets 7a, and the second pocket 7b has the same axial dimension H2 as the other second pockets 7b. The same.

In FIG. 4, the dimension (dimension along the circumferential direction) Ba between the open ends 10a, 10a of the first pocket 7a is set to be smaller than the diameter D of the ball 3 (Ba <D). The dimension (dimension along the circumferential direction) Bb between the open ends 10b, 10b of the two pockets 7b is set smaller than the diameter D of the ball 3 (Bb <D). The dimension Ba and the dimension Bb are set to be the same (Ba = Bb).
As described above, the positions (depths H1 and H2) of the pockets 7a and 7b in the axial direction are different, but since the dimension Ba and the dimension Bb are set to be the same, the balls contained in the pockets 7a and 7b. The holding force which suppresses that 3 slips out from the opening end is the same.

  And in each of the 1st pocket 7a and the 2nd pocket 7b, since dimension Ba and Bb between opening ends is set smaller than the diameter D of the ball 3, in this cage | basket 4, the ball | bowl 3 is used. When passing between the opening ends 10a, 10a of the first pocket 7a in the axial direction (vertical direction in FIGS. 3 and 4) and pushing it into the pocket 7a, the ball 3 causes the opening ends 10a, 10a to Is elastically expanded. Furthermore, when the ball 3 is pushed between the open ends 10b, 10b of the second pocket 7b in the axial direction (vertical direction in FIGS. 3 and 4) and pushed into the pocket 7b, the ball 3 opens. The space between the ends 10b and 10b is elastically expanded. That is, the ball 3 elastically deforms the claw portion 17a (and the claw portion 17b), so that the ball 3 can pass between the claw portions 17a and 17a (between the claw portions 17b and 17b).

  In this way, in each of the first pocket 7a and the second pocket 7b, the ball 3 to be pressed elastically spreads between the open ends 10a, 10a (10b, 10b). Resistance force works when passing between 10a (10b, 10b). Therefore, in order to push the ball 3 into each of the first pocket 7a and the second pocket 7b, it is necessary to give the ball 3 a pushing force against the resistance force. In addition, since the said dimension Ba and the said dimension Bb are set the same, the pushing force required in order to push in the ball | bowl 3 is the same (substantially same) by the 1st pocket 7a and the 2nd pocket 7b. It becomes.

  Therefore, according to the present invention, the opening ends 10a and 10a of the first pocket 7a are different in position in the axial direction from the opening ends 10b and 10b of the second pocket 7b. ) In the first pockets 7a and the second pockets 7b, the timing between the opening ends when the balls 3 pass is increased with the second pocket 7b first, and the first pocket with a delay. 7a. For this reason, as shown in FIG. 5, in order to push all the balls 3 into all the pockets 7a and 7b, the pushing force (incorporating force) P necessary to be applied to the balls 3 is dispersed twice. Can do.

Thereby, the required pushing force P with respect to the ball 3 can be made smaller than before. That is, in the conventional configuration shown in FIG. 6, the axial dimension h from the bottom 45 of the pocket 42 to the open ends 44, 44 is the same for all the pockets 42. When the pushing force required to push the balls 43 is F and the number of balls 43 (number of pockets) is N, it is necessary to push all the balls 43 into the pockets 42 at the same time. The pushing force P is P = F × N. That is, as the number (N) of balls 43 increases, the necessary (maximum) pushing force P increases.
On the other hand, according to the present invention, the pushing force P that needs to be applied to the balls 3 can be dispersed twice with a time difference, so that the balls 3 can be placed in the first pocket 7a or the second pocket 7b. When the pushing force required to push in is F and the number of balls 3 (number of pockets) is N, the pushing force P necessary to push all the balls 3 into the pockets 7a and 7b is P = F XN / 2 (half of the conventional value). Thereby, the maximum output required to push the ball 3 into the cage 4 can be made smaller than before.

  Further, as shown in FIG. 2, in the cage 4, the first pockets 7a and the second pockets 7b are alternately arranged in the circumferential direction. The positions in the axial direction are alternately different in the circumferential direction. For this reason, a jig (not shown) that can press all the (three) balls 3 in contact with each ball 10 is used and pushes all the balls 3 into all the pockets 7a and 7b. In the inserting operation, the balls 3 are pushed linearly along the axial direction by the jig, and the jig presses a plurality (five) of the balls 3 to the cage 4 every other circumferential direction. 3 is first pushed into the second pocket 7b, then the jig pushes the remaining (five) balls 3 against the cage 4 every other circumferential direction, and pushes these balls 3 into the first pocket 7a. Can do.

  Thus, although it is every other circumferential direction, since the said jig | tool can push the five balls | bowls 3 first simultaneously on the whole circumference | surroundings, a jig | tool and the ball | bowl 3 are stabilized in an axial direction linearly (fluctuating). The first ball 3 is pushed in smoothly. Subsequently, since the jig can push the remaining five balls 3 simultaneously around the entire circumference, the jig and the balls 3 can move stably in a straight line in the axial direction. 3 is smoothly carried out. Thus, all the balls 3 can be pushed into the pockets 7a and 7b by the operation of moving the jig to the cage 4 only once (one stroke of the jig). Since the pushing force P required to push all the balls 3 into the pockets 7a and 7b can be dispersed twice as shown in FIG. 5, the necessary pushing force P can be made larger than before. Can be small.

  According to the above-described cage 4 and the ball bearing provided with the cage 4, it is necessary to give the ball 3 to the ball 7 in order to push all the balls 3 into the pockets 7 a and 7 b when the ball bearing is manufactured. Since it is possible to disperse the pushing force with a plurality of times, it is possible to make the necessary pushing force smaller than the conventional pushing force. As a result, the operation of attaching the ball 3 to the cage 4 is facilitated, and the productivity of the ball bearing can be improved. In addition, since the pushing force can be made smaller than before, it is possible to prevent an unnecessarily large force from acting on the claw portion 17a (17b) from the ball 3 and damage the claw portion 17a (17b). Can be prevented.

Further, the present invention is not limited to the illustrated form, and other forms may be employed within the scope of the present invention. For example, in the embodiment, half of the plurality of pockets is the first pocket 7a and the remaining half is the second pocket 7b. However, the number of the second pockets 7b is larger than the number of the first pockets 7a. May be less or less. That is, it is only necessary that the opening end of at least one of the plurality of pockets is different from the opening end of the other pocket in the axial direction.
In the embodiment, two types of pockets having different axial dimensions have been described. However, three or more types of pockets may be used.
Further, in FIG. 3, the intermediate portions 23 and 23 of the second pocket 7 b have been described as a linear cylindrical surface shape, but in addition to this, the intermediate portions 23 and 23 are not linear but swell outward. (Barrel shape) may be sufficient.

It is sectional drawing which shows one Embodiment of the ball bearing of this invention. It is a perspective view of a holder | retainer. It is sectional drawing of a 1st pocket part and a 2nd pocket part. It is sectional drawing of a 1st pocket part and a 2nd pocket part. It is explanatory drawing of pushing force required in order to push a ball into a pocket. It is explanatory drawing of the conventional holder | retainer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3 Ball 4 Crown type cage 7a Pocket 7b Pocket 9a Inner wall surface 9b Inner wall surface 10a Open end 10b Open end 11 Outer raceway surface 12 Inner raceway surface 21 First spherical surface portion 22 Second spherical surface portion 23 Middle portion Ba Opening Dimension Bb between the ends Dimension C0 between the open ends C0 Center point C1 Center point C2 Center point

Claims (5)

A crown-type cage in which a plurality of pockets opened on one side in the axial direction to hold a plurality of balls of a ball bearing in a freely rolling manner are formed in the circumferential direction,
The crown type retainer, wherein the opening end of at least one of the plurality of pockets is different from the opening end of another pocket in the axial direction.   The inner wall surface of the one pocket has a first spherical surface portion on the bottom side and a second spherical surface portion on the open end side formed in a spherical shape centering on two points different in the axial direction, and an axial direction between the spherical surface portions. The crown type retainer according to claim 1, further comprising an intermediate portion extending and interposed therebetween.   The crown type holder according to claim 1 or 2, wherein the plurality of pockets are alternately different in the circumferential direction with respect to the axial position of the opening end.   The crown type retainer according to any one of claims 1 to 3, wherein a dimension between the opening ends of the one pocket and a dimension between the opening ends of the other pocket are the same.   An outer ring, an inner ring, an outer raceway surface formed on the outer ring, a plurality of balls that roll on the inner raceway surface formed on the inner ring, and the crown-type holding according to any one of claims 1 to 4 A ball bearing characterized by comprising a container.

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