JP2024032173A - Crown cage and ball bearing - Google Patents

Abstract

An object of the present invention is to provide a crown-shaped retainer and a ball bearing with improved reliability.
A crown-shaped retainer 10 includes an annular ring portion 11, a plurality of pillar portions 12 that protrude from the ring portion 11 to one side in the axial direction, and are formed to be lined up along the circumferential direction. Equipped with. A pocket 20 in which one of the plurality of balls is arranged is formed between the adjacent column parts 12. The inner surface 20a of the pocket 20 extends along a cylinder having a central axis parallel to the radial direction. At least in a portion of the ring portion 11 corresponding to the bottom portion 21 of the pocket 20, a protrusion 15 that protrudes inward or outward in the radial direction is formed.
[Selection diagram] Figure 2

Description

The present invention relates to a crown cage and a ball bearing.

Patent Document 1 includes a circular ring part and a plurality of pillar parts arranged at intervals in the circumferential direction on one side in the axial direction of the circular ring part, and the pillar parts and the circular ring part that are adjacent to each other in the circumferential direction. A crown-shaped retainer is described having a spherical pocket formed by and holding a plurality of balls. This crown type retainer is used in ball bearings.

Utility model registration No. 3210224

When using a ball bearing as described above, the cage rotates at high speed. At this time, the centrifugal force causes the tip of the column to deform radially outward, which may generate stress at the bottom of the pocket. In this case, there is concern that the tip of the deformed column portion may interfere with the outer ring or that the cage may be damaged due to stress. From the viewpoint of reliability, it is necessary to suppress the occurrence of such situations.

Therefore, an object of the present invention is to provide a crown-shaped retainer and a ball bearing with improved reliability.

The crown-type retainer of the present invention is [1] a crown-type retainer for rotatably retaining a plurality of balls arranged in a row along the circumferential direction, and includes an annular ring portion; a plurality of pillars protruding from the ring part to one side in the axial direction and arranged along the circumferential direction, and one of the plurality of balls is arranged between the adjacent pillars. A pocket is formed in which the pocket is arranged, and the inner surface of the pocket extends along a cylinder having a central axis parallel to the radial direction, and at least a portion of the ring portion corresponding to the bottom of the pocket has a , a crown-type retainer in which a protrusion that protrudes radially inward or outward is formed.

In this crown-type retainer, the inner surface of the pocket extends along a cylinder having a central axis parallel to the radial direction. A crown-shaped retainer having such a cylindrical pocket can be used in an outer ring guide or an inner ring guide bearing rather than a ball guide (rolling element guide). When the pocket is cylindrical, the column part is less likely to interfere with the ball even if it is deformed by centrifugal force. On the other hand, when the pocket is cylindrical, the column portion is more likely to be deformed by centrifugal force when the cage rotates at high speed, compared to, for example, a spherical pocket. In this regard, in this crown-shaped retainer, a projection protruding radially inward or outward is formed at least in a portion of the ring portion corresponding to the bottom of the pocket. Thereby, the rigidity of the crown-shaped retainer can be increased, and deformation due to centrifugal force can be suppressed. Therefore, according to this crown-shaped retainer, reliability can be improved.

The crown-shaped retainer of the present invention may be [2] "the crown-shaped retainer according to [1], which is formed of a resin material". In this case, the crown-shaped retainer can be manufactured by injection molding using a resin material, for example, and manufacturing can be facilitated. Furthermore, since the protrusion is formed in at least the portion of the ring portion corresponding to the bottom of the pocket, the portion can be formed thicker, and the weld position can be easily moved away from the portion during injection molding. As a result, it is possible to suppress the occurrence of a situation in which the strength of the part is reduced due to the weld position being located in the part, and it is possible to further improve reliability.

[3] The crown-type retainer according to [1] or [2], wherein the protrusion is formed only in a portion of the ring portion that corresponds to the bottom of the pocket. ”. In this case, the rigidity of the portion of the ring portion corresponding to the bottom of the pocket can be increased, and deformation due to centrifugal force can be suppressed.

The crown-type retainer of the present invention is [4] "the crown-type retainer according to any one of [1] to [3], wherein the protrusion projects radially inward from the ring portion". It's okay. In this case as well, the rigidity of the crown-shaped retainer can be increased and deformation due to centrifugal force can be suppressed.

The crown-type retainer of the present invention is [5] "the crown-type retainer according to any one of [1] to [3], wherein the projection projects radially outward from the ring portion". It's okay. In this case as well, the rigidity of the crown-shaped retainer can be increased and deformation due to centrifugal force can be suppressed.

The ball bearing of the present invention includes [6] "an inner ring, an outer ring, a plurality of balls arranged between the inner ring and the outer ring, and a ball bearing that holds the plurality of balls in a rollable manner [1]" [5] A ball bearing comprising the crown-shaped retainer according to any one of [5]. This ball bearing can improve reliability for the reasons mentioned above.

According to the present invention, it is possible to provide a crown-shaped retainer and a ball bearing with improved reliability.

It is a sectional view of the ball bearing of an embodiment. It is a perspective view of the holder of an embodiment. It is a sectional view of a ball bearing of a modification. It is a perspective view of the cage of a modification.

Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, the same reference numerals will be used for the same or equivalent elements, and overlapping description will be omitted.

As shown in FIG. 1, the ball bearing 1 includes an inner ring 2, an outer ring 3, a plurality of balls 5, and a cage 10 (crown-shaped cage). The ball bearing 1 is used, for example, to support a rotor in an electric compressor. Hereinafter, the direction parallel to the center line A of the ball bearing 1 will be referred to as the axial direction, and the direction perpendicular to the center line A will be referred to as the radial direction. The direction along the circumference is called the circumferential direction.

The inner ring 2 is formed in an annular shape and has an inner ring raceway surface 2a. The inner ring raceway surface 2a is a surface facing outward in the radial direction, and extends in an annular shape along the circumferential direction. The inner ring raceway surface 2a is formed in a shape corresponding to the balls 5. The inner ring 2 is fitted with a shaft (not shown), for example, on the inside in the radial direction.

The outer ring 3 is formed in an annular shape and is arranged outside the inner ring 2 in the radial direction. The outer ring 3 has an outer ring raceway surface 3a and a guide surface 3b. The outer ring raceway surface 3a and the guide surface 3b are surfaces facing inward in the radial direction, and extend in an annular shape along the circumferential direction. The outer ring raceway surface 3a is formed in a shape corresponding to the balls 5. The guide surface 3b is configured, for example, by a pair of surfaces (a pair of surfaces extending annularly along the circumferential direction) located on both sides of the outer ring raceway surface 3a in the axial direction. The outer ring 3 is fitted into a housing (not shown), for example, on the outside in the radial direction.

Each of the plurality of balls 5 is formed into a spherical shape. The plurality of balls 5 are arranged between the inner ring raceway surface 2a and the outer ring raceway surface 3a. The plurality of balls 5 are held by a retainer 10, and are arranged in a line along the circumferential direction at predetermined intervals.

The retainer 10 is disposed between an inner raceway surface 2a of the inner ring 2 and an outer raceway surface 3a of the outer race 3, and holds a plurality of balls 5 in a freely rolling manner. In this example, the cage 10 is guided by the guide surface 3b of the outer ring 3. That is, the ball bearing 1 is configured as an outer ring guided bearing. The cage 10 is, for example, a crown-shaped cage made of a resin material. The cage 10 is formed, for example, by injection molding using a resin material. The retainer 10 has a plurality of pockets 20 (seven in this example). A plurality of balls 5 are arranged in each of the plurality of pockets 20.

As shown in FIG. 2, the retainer 10 includes a ring portion 11 and a plurality of (seven in this example) pillar portions 12. The ring portion 11 is formed in an annular shape. Each column portion 12 projects from the ring portion 11 to one side in the axial direction (upper side in FIG. 2). The plurality of pillar portions 12 are formed so as to be lined up at predetermined intervals along the circumferential direction. The above-mentioned pocket 20 is formed between adjacent column parts 12. The pocket 20 is defined by a pair of adjacent pillar parts 12 and a part 11a of the ring part 11 extending between them.

Each column portion 12 has a main body portion 13 and a pair of claw portions 14 . The main body portion 13 protrudes from the ring portion 11 to one side in the axial direction. The pair of claw portions 14 protrude from the main body portion 13 to one side in the axial direction. The pair of claw parts 14 includes a claw part 14a arranged on one side in the circumferential direction and a claw part 14b arranged on the other side in the circumferential direction. The claw portion 14a extends toward one side in the circumferential direction as the distance from the main body portion 13 increases, and the claw portion 14b extends toward the other side in the circumferential direction as the distance from the main body portion 13 increases. There is. The main body portion 13 and the pair of claw portions 14 define a pocket 20. The pair of claws 14 prevents the ball 5 placed in the pocket 20 from falling off in the axial direction.

Pocket 20 is formed into a cylindrical shape. Specifically, the inner surface 20a of the pocket 20 extends along a cylinder having a central axis parallel to the radial direction. As described above, the pocket 20 is defined by the portion 11a of the ring portion 11, the main body portion 13 of the column portion 12, and the pair of claw portions 14. A portion 11 a of the ring portion 11 defines a bottom portion 21 of the pocket 20 . That is, the portion 11a is a portion of the ring portion 11 that corresponds to the bottom portion 21 of the pocket 20. "The portion of the ring portion 11 corresponding to the bottom portion 21" refers to, for example, a portion of the ring portion 11 that defines the bottom portion 21 and overlaps with the bottom portion 21 when viewed from the axial direction.

A portion 11a of the ring portion 11 is formed with a protrusion 15 that protrudes inward in the radial direction. The protrusion 15 is formed on the inner peripheral surface of the ring portion 11. The protrusion 15 is formed only on a portion 11a of the ring portion 11, and is not formed on other portions of the ring portion 11 (for example, the connection portion with the column portion 12). The retainer 10 has a plurality of (seven in this example) protrusions 15. The plurality of protrusions 15 are formed so as to be lined up at predetermined intervals along the circumferential direction.

In the axial direction, the protrusion 15 is formed between the bottom 21 of the pocket 20 and the surface of the ring portion 11 on the side opposite to the pocket 20. The protrusion 15 has a curved surface 15 a continuous with the bottom 21 of the pocket 20 . The length of the protrusion 15 in the circumferential direction is shorter than the length of the pocket 20 in the circumferential direction. In this example, the pair of side surfaces 15b of the protrusion 15 in the circumferential direction are inclined surfaces that are inclined toward each other as the protrusion 15 approaches the center line A (as it goes inward in the radial direction). The length of the protrusion 15 in the radial direction is shorter than the length of the ring portion 11 in the radial direction.
[Action and effect]

In the retainer 10, the inner surface 20a of the pocket 20 extends along a cylinder having a central axis parallel to the radial direction. The cage 10 having such a cylindrical pocket 20 can be used not in a ball guide (rolling element guide) but in an outer ring guide or an inner ring guide bearing. When the pocket is cylindrical, the column part is less likely to interfere with the ball even if it is deformed by centrifugal force. On the other hand, when the pocket 20 is cylindrical, deformation due to centrifugal force is more likely to occur in the column part 12 (claw part 14) when the cage 10 rotates at high speed, compared to, for example, when the pocket 20 is spherical. . In this regard, in the retainer 10, a projection 15 that projects inward in the radial direction is formed in a portion 11a of the ring portion 11 (a portion corresponding to the bottom portion 21 of the pocket 20). Thereby, the rigidity of the cage 10 can be increased. That is, the rigidity of the portion 11a of the ring portion 11 can be increased, and the rigidity of the cage 10 as a whole can be increased. As a result, deformation of the cage 10 due to centrifugal force can be suppressed. Therefore, according to the cage 10, reliability can be improved.

The cage 10 is made of resin material. Thereby, the cage 10 can be manufactured by injection molding using a resin material, for example, and manufacturing can be facilitated. Further, since the projection 15 is formed on the portion 11a of the ring portion 11, the portion 11a can be formed thickly, and the weld position can be easily moved away from the portion 11a during injection molding. As a result, it is possible to suppress the occurrence of a situation where the strength of the part 11a is reduced due to the weld position being located in the part 11a, and reliability can be further improved.

That is, when the protrusion 15 is not formed, the cross-sectional area of the part 11a of the ring portion 11 (the area of the cross section perpendicular to the circumferential direction) and the cross-sectional area of the connecting portion of the ring portion 11 with the pillar portion 12 (the area of the cross section perpendicular to the circumferential direction) (area of vertical cross section) (thickness difference) becomes large. In this case, since the cross-sectional area of the portion 11a is small, when pouring the molten resin into the mold during injection molding, the flow rate of the resin becomes slow in the portion corresponding to the portion 11a. Therefore, a weld position (a position where the resin that has flowed into the mold joins) is likely to be located in the part 11a of the ring portion 11. In other words, it is difficult to adjust the injection gate position or injection conditions so that the weld position is located in a portion other than the portion 11a of the ring portion 11. At the weld position, it is difficult for the resins to fuse together, and the strength after molding tends to decrease. In the retainer 10, the part 11a of the ring part 11 is the thinnest part and has the lowest strength, so if the weld position is located in the part 11a of the ring part 11, the strength of the part 11a will further decrease. In this respect, in the retainer 10, since the protrusion 15 is formed on the part 11a of the ring part 11, the part 11a can be formed thick (the cross-sectional area of the part 11a can be increased). ), it becomes easier to move the weld position away from part 11a during injection molding. As a result, it is possible to suppress the occurrence of a situation where the strength of the part 11a is reduced due to the weld position being located in the part 11a, and reliability can be further improved.

The protrusion 15 is formed only on a portion 11a of the ring portion 11. Thereby, the rigidity of the portion 11a of the ring portion 11 can be increased, and deformation due to centrifugal force can be suppressed. Moreover, it becomes easier to move the weld position away from the part 11a during injection molding.

A projection 15 projects radially inward from the ring portion 11. Thereby, the rigidity of the cage 10 can be increased, and deformation due to centrifugal force can be suppressed.
[Modified example]

In the modification shown in FIGS. 3 and 4, the protrusion 15 protrudes outward in the radial direction from a portion 11a of the ring portion 11. In this variant, the retainer 10 is guided by the outer ring 3 at the protrusion 15 . More specifically, the radially outer surface 15c of the protrusion 15 serves as a guide surface for the outer ring 3, and the surface 15c is guided by the guide surface 3b of the outer ring 3. Even with such a modification, reliability can be improved similarly to the above embodiment. Furthermore, since the projections 15 serve as guide surfaces for the outer ring 3, the contact area between the cage 10 and the outer ring 3 can be reduced, and the friction generated between the cage 10 and the outer ring 3 can be reduced. Yes (low friction effect).

The present invention is not limited to the above embodiments and modifications. For example, the materials and shapes of each structure are not limited to the materials and shapes described above, and various materials and shapes can be employed. The cage 10 may be made of a material other than resin material.

In the above embodiment, the protrusion 15 was formed only on the part 11a of the ring part 11, but the protrusion 15 may be formed at least on a part of the ring part 11 corresponding to the bottom part 21 of the pocket 20, for example, on the ring part 11. It may be formed over the entire circumference of the portion 11, or may be formed so as to extend from the portion 11a to the connection portion with the column portion 12 in the ring portion 11. The portion 11a of the ring portion 11 may be formed with both a protrusion that protrudes inward in the radial direction and a protrusion that protrudes outward in the radial direction.

The ball bearing 1 may be configured as an inner ring guided bearing. In this case, the protrusion 15 may be formed to protrude axially inward from the portion 11a of the ring portion 11, and the retainer 10 may be guided by the inner ring 2 at the protrusion 15. In this case, the contact area between the cage 10 and the inner ring 2 can be reduced, and the friction generated between the cage 10 and the inner ring 2 can be reduced. In the case of an inner ring guide, the protrusion 15 may be formed to protrude outward in the axial direction from a portion 11a of the ring portion 11.

DESCRIPTION OF SYMBOLS 1... Ball bearing, 2... Inner ring, 3... Outer ring, 5... Ball, 10... Cage (crown type cage), 11... Ring part, 12... Pillar part, 15... Protrusion, 20... Pocket, 20a... Inner surface, 21...Bottom.

Claims (6)

A crown-shaped cage for rotatably holding a plurality of balls arranged in a row along the circumferential direction,
An annular ring part,
a plurality of column parts that protrude from the ring part to one side in the axial direction and are formed to be lined up along the circumferential direction,
A pocket in which one of the plurality of balls is arranged is formed between the adjacent pillar parts,
The inner surface of the pocket extends along a cylinder having a central axis parallel to the radial direction,
A crown-type retainer, wherein at least a portion of the ring portion corresponding to the bottom of the pocket is formed with a protrusion that protrudes radially inward or outward. The crown-shaped retainer according to claim 1, which is formed of a resin material. The crown-type retainer according to claim 1 or 2, wherein the protrusion is formed only in a portion of the ring portion that corresponds to the bottom of the pocket. The crown-type retainer according to claim 1 or 2, wherein the projection projects radially inward from the ring portion. The crown-type retainer according to claim 1 or 2, wherein the projection projects radially outward from the ring portion. An inner ring, an outer ring, the plurality of balls arranged between the inner ring and the outer ring, and the crown-shaped retainer according to claim 1, which rotatably holds the plurality of balls. Equipped with ball bearings.

Images