JP2015031386A - Synthetic resin cage for angular contact ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide one-side annular type synthetic resin cage for angular contact ball bearing capable of increasing the number of pockets and the number of balls that can be held and effectively eliminating poor outer appearance.SOLUTION: This invention relates to a synthetic resin cage 1 for angular contact ball bearing injection molded through split molds axially opened and formed with a plurality of pockets 4, 4, ... to which balls are fitted through an annular part 2 and each of a plurality of pillar sections 3, 3... in a circumferential direction while being protruded from the annular part 2 in an axial direction, and its shape is made such that a filling pressure at each of the inner diameter portions 3A, 3A, ... of the pillar sections 3, 3, ... is low and a corner part at an extremity end inner diameter side resulting in poor outer appearance is cut. Manufacturing of the cage that could not be made in the prior art structure due to essential occurrence of poor outer appearance (poor filling) can be carried out and at the same time, it is possible to improve yield in the manufacturing of the cage in the prior art structure where poor outer appearance (poor filling) occurs to cause the yield to become poor.

Description

  The present invention relates to a synthetic resin molded cage used for an angular ball bearing, and more particularly to a single-sided annular (crown) cage that can increase the load capacity by increasing the number of balls.

In the case of angular ball bearings, there is a growing need for higher load capacity. When the inner and outer diameters and the ball diameter are determined, it is necessary to increase the number of balls in order to increase the load capacity. It is also necessary to increase the number of pockets of the synthetic resin cage used for the bearing.
As a cage made of synthetic resin for angular ball bearings, as seen in Patent Documents 1 and 2, an annular part (ring part) (2) and a shape protruding from the annular part (2) in the axial direction respectively. One-side annular type (crown type) in which a plurality of pockets (5, 5,...) Into which balls (4, 4,...) Fit are formed by a plurality of column portions (3, 3,...) Formed in the circumferential direction. ) Of synthetic ball cages for angular ball bearings (see Patent Documents 1 and 2).
Synthetic resin cages for such single-sided annular ball bearings are generally injection-molded using a split mold that opens in the axial direction. Parting of an injection mold In the case of Patent Document 1, the line is made to coincide with the pitch circle position, and in the case of Patent Document 2, the line is set to the outside in the radial direction from the pitch circle position.
Since the force acting at the time of demolding is reduced by injection molding using a split mold that opens the synthetic resin cage for one-side annular type angular ball bearings in the axial direction as described above. Since it is not necessary to increase the width of the part (3, 3,...) Excessively, the number of balls can be increased.

In addition, by setting the parting line of the mold to be radially outward from the pitch circle position as in Patent Document 2, the columnar inner diameter side portion (3A) is in contrast to the columnar outer diameter side portion (3B). Since the connection is made at a position thicker than the pitch circle position on the outer side in the radial direction than the pitch circle, the connection area between the column portion inner diameter side portion (3A) and the column portion outer diameter side portion (3B) is increased. Since the mechanical strength of the pillar portion (3, 3,...) Can be increased, the ball (4, 4,...) Can be inserted into the pocket (5, 5,...) Of the cage (1). The column portion (3, 3,...) Can be made less likely to break when the load is applied from the ball (4, 4,.
As a result, the thickness at the pitch circle position of the columnar inner diameter side portion (3A) can be reduced, so that the balls (4, 4,...) That can be held even with the cage (1) having the same pitch circle diameter (PCD). The number of can be increased.

JP-A-10-103359 JP 2011-027257 A

As described above, the synthetic resin cage for angular ball bearings of Patent Documents 1 and 2 has a certain effect that the number of balls that can be held is increased by increasing the number of pockets.
However, when prototypes and resin flow analysis conducted by the inventors in response to demands for higher load capacity in recent years have further advanced the thinning of the pillars, they are filled with reinforcing materials such as glass fibers. In combination with the large number of rings, there may be a case where a single-sided annular type ball bearing made of synthetic resin for angular ball bearings is injection-molded, such as a thin wall that can be visually recognized or a minute chip that cannot be visually recognized. I understood that.
When appearance defects such as these occur, the product becomes a defective product and the yield deteriorates.
In addition, even if it is a fine chip that can not be recognized visually, if there is such a poor appearance, it will lead to cracks in use or sharp protrusions will fall off and become foreign matter, etc. It is necessary to eliminate the fine chips.

  Therefore, in view of the above-described situation, the present invention intends to solve the problem that the number of pockets can be increased to increase the number of balls that can be held, and the appearance defect can be effectively eliminated, It is in providing a synthetic resin cage for angular contact ball bearings.

In view of the above-mentioned problems, the inventors of the present application have a conventional synthetic resin cage 1A for the angular ball bearing shown in the enlarged perspective view of the main part in FIG. 5 (the inner diameter conical surface 5 is formed with the inner ring of the angular ball bearing. The resin flow analysis is performed to avoid interference, and from the distribution of the filling pressure, an intersection line between the inner diameter conical surface 5 and the front end surface 6 of the columnar inner diameter side portion 3A (in FIG. 5). In the vicinity of the tip inner diameter side corner portion A.), it was found that the filling pressure rapidly decreases.
And
(A) Since the place where the filling pressure is lowered is a place where it is difficult to fill the molten resin, if there is a place where the filling pressure is lowered, it tends to lead to the appearance defect.
(I) There is no problem in the strength of the cage even if the portion where the filling pressure is reduced is eliminated, and the product shape can be made by cutting the portion.
The present invention has been completed.

  That is, the synthetic resin cage for angular ball bearings according to the present invention includes a ring portion and a plurality of columns formed in the circumferential direction so as to protrude in the axial direction from the ring portion in order to solve the problems. And a plurality of pockets into which the ball fits, and a synthetic resin cage for an angular ball bearing that is injection-molded using a split mold that opens in the axial direction. The portion has a shape in which the corner on the inner diameter side of the tip that leads to poor appearance is cut off at a low filling pressure.

According to the synthetic resin cage for the angular ball bearing according to the present invention, since the filling pressure in the inner diameter side portion of the column portion is low and the corner portion on the inner diameter side leading to the appearance defect is cut out, the injection molding is performed. Since there is no corner on the inner diameter side of the tip that is difficult to fill, the filling pressure is low, and the appearance is poor, filling failure does not occur, and as a result, the appearance is a thin wall that can be recognized visually or a fine chip that cannot be visually recognized. There is no defect.
Therefore, it became possible to manufacture a cage that could not be manufactured due to the appearance failure (filling failure) that occurred in the conventional structure, and in the conventional structure, appearance failure (filling failure) might occur and the yield was poor. The yield in the production of the cage can be improved.

(A) is a perspective view of the synthetic resin cage for angular ball bearings concerning Embodiment 1 of the present invention, and (b) is the principal part expansion perspective view similarly. It is also a plan view. It is a perspective view of the synthetic resin cage for angular ball bearings concerning Embodiment 2 of the present invention, and (b) is the principal part expansion perspective view similarly. It is a principal part expansion perspective view of the synthetic resin cage for angular ball bearings concerning Embodiment 3 of this invention. It is a principal part expansion perspective view of the conventional synthetic resin cage for angular ball bearings.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown in the accompanying drawings, and includes all the embodiments that satisfy the requirements described in the claims. It is a waste.

Embodiment 1 FIG.
As shown in a perspective view of FIG. 1A, an enlarged perspective view of a main part of FIG. 1B, and a plan view of FIG. 2, a synthetic resin cage 1 for an angular ball bearing according to Embodiment 1 of the present invention. The ball B (see FIG. 2) fits in the ring portion 2 and the column portions 3, 3,... Formed in the circumferential direction so as to protrude from the ring portion 2 in the axial direction. Are formed by injection molding, for example, a resin obtained by adding 25 weight percent of glass fiber to nylon 66 using a split mold that opens in the axial direction.
Here, since the parting line of the mold is set radially outside the pitch circle position (see pitch circle diameter PCD in FIG. 2) as in Patent Document 2, the columnar inner diameter side portion 3A is It connects with the pillar part outer diameter side part 3B in the position thickened rather than the pitch circle position in the radial direction outer side rather than a pitch circle.
In addition, the synthetic resin cage 1 for the angular ball bearing has a low filling pressure in the conventional shape synthetic resin cage 1A for the angular ball bearing shown in FIG. Between the inner diameter conical surface 5 and the distal end surface 6, a C chamfered shape portion 7, which is a shape obtained by C-chamfering the distal end inner diameter side corner portion A of FIG. 5, is formed.

Embodiment 2. FIG.
A synthetic resin cage 1 for an angular ball bearing according to a second embodiment of the present invention is manufactured in the same manner as in the first embodiment, and is a perspective view of FIG. 3A and an enlarged perspective view of a main part of FIG. As shown in the figure, the synthetic resin cage 1 for the angular ball bearing of the first embodiment is a tip that has a low filling pressure in the conventional shape synthetic resin cage 1A for the angular ball bearing shown in FIG. Only the shape that eliminates the inner diameter side corner A is different.
That is, in the second embodiment, the inclined enlarged inner diameter conical surface shape portion 8 is formed by increasing the outward inclination angle of the inner diameter conical surface 5 of FIG.

Embodiment 3 FIG.
A synthetic resin cage 1 for an angular ball bearing according to a third embodiment of the present invention is manufactured in the same manner as in the first embodiment, and as shown in the enlarged perspective view of the main part of FIG. The ball bearing synthetic resin cage 1 is only in a shape that eliminates the corner portion A on the inner diameter side of the tip, which has a low filling pressure in the conventional plastic ball cage of synthetic ball bearing 1A shown in FIG. Is different.
In other words, in the third embodiment, an R chamfered shape portion 9 that is a shape obtained by rounding the tip inner diameter side corner portion A in FIG. 5 between the inner diameter conical surface 5 and the tip surface 6 is formed.

As described above, the synthetic resin cage 1 for the angular ball bearing of Embodiments 1 to 3 has a low filling pressure in the conventional shape synthetic resin cage 1A for the angular ball bearing shown in FIG. The inner diameter side corner A is removed so as to eliminate the inner diameter corner A, but any shape change is a shape change except for the ball holding part (cylindrical surface escaping from the spherical surface) The ball holding amount of the vessel 1 does not change.
In addition, regarding the change in strength due to the shape obtained by cutting away the tip inner diameter corner A, the stress of each part is equivalent to the conventional synthetic resin cage 1A for the angular ball bearing shown in FIG. It is confirmed that.

According to the structure of the synthetic resin cage 1 for the angular ball bearing as described above, the corner portion A (see FIG. 5) at the tip inner diameter side, which has a low filling pressure in the inner diameter portion 3A of the column portion and leads to poor appearance. Since it has a shape, it is difficult to fill during injection molding, and there is no tip inner diameter side corner A that leads to poor appearance with a low filling pressure, so there is no filling failure, and as a result, Appearance defects such as fine chips that cannot be visually recognized do not occur.
Therefore, it became possible to manufacture a cage that could not be manufactured due to the appearance failure (filling failure) that occurred in the conventional structure, and in the conventional structure, appearance failure (filling failure) might occur and the yield was poor. The yield in the production of the cage can be improved.
In the present invention, when a thermoplastic resin material such as nylon 66 containing a reinforcing material such as glass fiber is used, the tip inner diameter side corner portion A of the angular ball bearing synthetic resin cage 1A shown in FIG. This is effective for a width (thickness) of 1 mm or less, and particularly effective for a tip inner diameter side corner portion A having a width (thickness) of 0.5 mm or less.

A Tip inner diameter side corner (location with low filling pressure)
B Ball PCD Pitch Circle Diameter 1 Synthetic Resin Cage for Angular Ball Bearings 1A Synthetic Resin Cage for Angular Ball Bearings of Conventional Shape 2 Ring Part 3 Column Part 3A Column Part Inner Diameter Side Part 3B Column Part Outer Diameter Side Part 4 Pocket 5 Inner diameter conical surface 6 Tip surface 7 C chamfered shape portion 8 Inclined enlarged inner diameter conical surface shape portion 9 R Chamfered shape portion

Claims (1)

A split mold that opens in the axial direction and has a plurality of pockets into which the ball fits by an annular portion and a plurality of pillars that are formed in the circumferential direction so as to protrude from the annular portion in the axial direction. A synthetic resin cage for angular ball bearings that is injection molded using
A synthetic resin cage for an angular ball bearing, wherein the inner diameter side portion of the column portion has a shape in which a corner portion on the inner diameter side of the tip which has a low filling pressure and leads to poor appearance is cut off.

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