JP2600054Y2 - Crowned synthetic resin cage for miniature 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-shaped synthetic resin cage for miniature ball bearings.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 7 and 8, this type of retainer 40 is formed to be considerably larger than the ball pitch circle diameter, so that it is possible to reliably hold the ball and prevent the ball from falling off during rotation. However, it is difficult to fill grease from the back surface 46 of the cage 40 with a compact double row ball bearing. Therefore, when a ball having a relatively large diameter is fitted, grease can be sealed from the back.

In recent years, there has been a demand for a more compact miniature double row bearing. When a miniature bearing having a ball diameter of 2 mm or less is formed between the outer diameter of the outer ring and the outer diameter of the retainer and the outer diameter of the inner ring, the inner diameter of the retainer 40 is reduced. Became very small, and it became very difficult to fill grease from the back surface 46 of the cage.

As shown in FIG. 9, in a bearing with a shaft as well, a spring 100 and a spring seat 90 are provided between the two rows of outer rings 10, 10, and the retainer 40 is provided outside the two rows of outer rings 10, 10. Then, when grease is sealed, grease is sealed from the back surface 46 of the retainer 40.
For this reason, the ball diameter was reduced, and the gap between the inner diameter of the outer ring and the outer diameter of the cage was reduced, making it extremely difficult to fill grease.

[0005]

Therefore, as shown in FIG. 3, the outer diameter of the retainer 40 is made as small as possible to hold the ball 30 and the difference between the outer diameter of the outer ring and the inner diameter of the retainer 40 is increased. The grease is easily sealed.

[0006]

The components required to solve the technical problems of the present invention are as follows. That is, a crown for a miniature ball bearing in which a plurality of pockets each including a ball fitting recess and a holding claw that is curved and extended in the axial direction from the opening edge of the recess are provided on one side of the annular body. The outer diameter of the cage made of synthetic resin can not hold the ball by itself.
A crown-shaped synthetic resin cage for miniature ball bearings, characterized in that the outer diameter thereof is slightly larger than the ball pitch circle diameter when assembled in the bearing.

[0007]

[Function] By making the outer diameter of the retainer as small as necessary to hold the ball, it is possible to prevent the ball and the claw of the retainer from galling, and the ball falls out of the retainer. Can be prevented, and the gap with the inner diameter of the outer ring is increased, so that the grease can be easily filled from the back of the retainer.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The miniature double-row bearing incorporating the cage of the present invention includes an outer race 10 having raceways 11 and 12 and a raceway 1 of the outer race 10.
Shaft 20 on which orbits 21 and 22 corresponding to 1, 12 are formed
A number of balls 30 are fitted between the outer ring 10 and the shaft 20 via a synthetic resin crown retainer 40. Therefore,
In the present embodiment, the outer race 10 is a well-known structure having a general thickness.
Structure can be applied.

The crown-shaped retainer 40 has a pocket 45 formed on one side of an annular body 41 by a ball-fitting concave portion 42 and a retaining claw 44 extending in an axially curved manner from an opening edge 43 of the concave portion 42. A plurality is formed thereon.

The outer diameter Dk of the retainer 40 is slightly larger than the pitch circle diameter p as shown in FIG. Dw
Is the diameter of the ball. Reference numeral 50 denotes a seal fitted close to both ends of the outer ring 10.

A tangent is drawn to the ball pitch circle diameter p when the ball pitch circle diameter of the cage 40 is p, the ball diameter is Dw, and the cage outer diameter is Dk, and the point of contact with the ball diameter and the center point 0 are determined. The connecting radius a1 is represented by the following equation.

[0012] Assuming Dw, the difference a2 between the cage outer diameter Dk and the ball pitch circle diameter p is expressed by the following equation.

A2 = (Dk ÷ 2) -a1, and the ratio a2 ÷ Dw of a2 to the ball diameter Dw is preferably 0.1 or less, and more preferably 0.065 or less. However, if a2 ÷ Dw is 0 or less, the edge of the outer diameter portion of the cage comes into contact with the ball, which promotes wear of the cage and makes it difficult to hold the ball.

In a usual design, this value is 0.12 to 0.12.
Since it is about 0.17, it is difficult to seal grease. FIG.
FIG. 4 is a cross-sectional view showing another embodiment of the present invention. The difference from FIG. 1 is that in a miniature double row ball bearing, an inner ring 60 having one end of the shaft 20 reduced in diameter and having a thickness corresponding to the reduced diameter is provided. There is no difference in the operation and effect from the point of being fitted to the shaft 20.

Therefore, the same parts as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 5 is a sectional view showing a state in which grease 70 is sealed in the miniature double row ball bearing of FIG. FIG. 6 is a partial sectional view of a bearing with a shaft incorporating the cage of the present invention.

The track 2 is provided on the outer periphery of the shaft 20 at a predetermined interval.
The outer races 10, 10 on which the raceways 11, 12 corresponding to the raceways 21, 22 are respectively formed are ball 3
0 and the outer ring 1
Spring seats 90, 90 are respectively attached to the openings 0, 10, and a spring 100 is inserted between the spring seats 90, 90.

The left and right outer rings 10, 10 are formed by the spring 100.
Are preloaded in the axial direction, but there is no particular difference in the operation and effect. In other respects, the same reference numerals are given to the same portions as those in the above embodiment.

[0018]

According to the crown type synthetic resin cage of the present invention, a gap is provided between the outer diameter of the cage and the inner diameter of the outer ring by making the outer diameter of the cage slightly larger than the diameter of the ball pitch. Due to the large size, strength reduction in miniature ball bearings
This has a specific effect in commercialization such that grease can be sealed relatively easily without causing the possibility of causing grease.

Although the thickness of the retainer in the radial direction is slightly reduced, the balls incorporated therein are held at predetermined intervals by the pockets of the retainer, and the pockets are provided with claws extending in the axial direction. By having this, it also has a function of preventing the ball from falling off from the pocket.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a miniature double-row ball bearing incorporating a cage of the present invention.

FIG. 2 is a perspective view of the cage of the present invention.

FIG. 3 is a schematic explanatory view showing a relationship between an outer diameter of a retainer and a ball pitch circle diameter.

FIG. 4 is a sectional view showing another embodiment of the present invention.

5 is a cross-sectional view showing a state where grease is sealed in the double-row ball bearing of FIG.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view showing a conventional example of the present invention.

FIG. 8 is a sectional view showing a conventional example of the present invention.

FIG. 9 is a sectional view showing a conventional example of the present invention.

[Explanation of symbols]

 10: Outer ring 11, 12: Track of outer ring 20: Shaft 21, 22: Track of shaft 30: Ball 40: Retainer 42: Recess 43: Opening edge 44: Holding claw 45: Pocket 46: Back face of the retainer 50 : Seal 70: Grease 90: Spring seat 100: Spring Dk: Outer diameter of cage p: Ball pitch circle diameter

Claims (1)

(57) [Scope of request for utility model registration] 1. A miniature ball provided on one side of an annular body with a plurality of pockets on a circumference formed by a ball fitting concave portion and a holding claw extending in a curved direction in an axial direction from an opening edge of the concave portion. in coronary shaped synthetic resin cage bearing, hold the balls alone
A crown-shaped synthetic resin cage for miniature ball bearings, having an outside diameter that cannot be obtained and whose outside diameter is slightly larger than the ball pitch circle diameter when assembled in the bearing.