JPH0530552U - Shaft unit bearing - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the lubricity of the shaft unit bearing and suppress the occurrence of uneven rotation due to the adhesion of grease on the shaft. [Structure] A plurality of balls 5 are incorporated inside the outer ring 3. A pair of holding claws 8 are provided in the circumferential direction on one side surface, and the ball 5 is held by a cage 6 in which a pocket 9 is formed between the holding claws 8. A plurality of grease reservoirs 12 are formed on the other side surface of the cage 6, and the rolling surface of the ball 5 is lubricated with the oil component of the grease G filled in the grease reservoir 12 so that the components other than the oil component in the grease adhere to the shaft 1. Shaft 1 to prevent
Suppress uneven rotation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shaft unit bearing used for a scanner motor of a laser beam printer, a cylinder motor of a video tape recorder, a spindle motor of a hard disk drive and the like.

[0002]

[Prior Art]

As shown in FIG. 4, the shaft unit has a configuration in which double-row raceway grooves 2 are provided on the outer diameter surface of the shaft 1, and bearings A ₁ and A ₂ are incorporated outside each raceway groove 2.

The bearings A ₁ and A ₂ of the shaft unit have an outer ring 3, and a ball 5 is assembled between a raceway groove 4 formed on the inner diameter surface of the outer race 3 and a raceway groove 2 of the shaft 1, and the ball 5 is attached to the ball 5. It is configured to be held by a holder 6.

Here, as shown in FIG. 5 and FIG. 6, the cage 6 has an annular portion 7, and a pair of holding claws 8 facing each other on one side surface of the annular portion 7 at equal intervals in the circumferential direction. A pocket 9 is formed between the pair of holding claws 8 and is inserted from one side of the outer ring 3 into the inner side of the outer ring 3.

In the above shaft unit, in order to improve the rotation accuracy of the shaft 1, a pair of spring seats 10 and a spring 11 are installed between the pair of outer rings 3, and the springs 10 form a pair of spring seats 10. The outer ring 3 is pressed outward to apply a preload to the ball 5 in the axial direction.

Further, in order to suppress uneven rotation of the shaft 1, grease 9 is filled between the adjacent holding claws 8 and the rolling surface of the ball 5 is lubricated by the oil component in the grease flowing in the raceway grooves 2 and 4. There is.

[0007]

[Problems to be solved by the device]

By the way, since the shaft unit is small with an axial length of 10 mm and an outer diameter of a few mm, the grease should be sealed in the pair of bearings A ₁ and A ₂ as shown by the arrow in FIG. It is necessary to seal from the direction indicated by.

In the shaft unit, one of the pair of bearings A ₁ and A ₂ is assembled on the outside of the shaft 1, then the spring seat 10, the spring and the spring seat 10 are assembled in order, and the remaining bearing A ₂ is assembled. Therefore, the cage 6 of the bearing A ₂ to be assembled lastly needs to be assembled from the end of the shaft 1 into the outer ring 3 with the opening side of the pocket 9 as the front side.

Therefore, the grease is filled into the bearing (the bearing on the right side in FIG. 4) A ₂ which is installed lastly from the side opposite to the opening side of the pocket 9, and may be filled between the adjacent holding claws 8. Can not. Therefore, the encapsulated grease enters the rolling surface without staying, and the thickening agent in the grease intervenes between the ball rolling surfaces, causing uneven rotation of the shaft 1. .

This invention solves the above-mentioned inconvenience, and lubricates the ball rolling surface with oil in the grease to prevent the thickening agent rolling surface and balls from intervening to suppress uneven rotation of the shaft. It is a technical issue.

[0011]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, an outer ring, balls incorporated inside the outer ring, and a retainer for holding each ball are provided. In a shaft unit bearing consisting of holding pawls arranged at equal intervals in the circumferential direction and forming a pocket between a pair of opposing holding pawls, a grease reservoir is formed on the other side of the annular part of the cage, and the grease reservoir is formed. We adopted a configuration in which grease is filled in.

[0012]

[Action]

 With the above configuration, grease oil flows into the raceway grooves and lubricates the rolling surface of the ball, and components other than oil are retained in the grease reservoir and prevented from adhering to the shaft.

[0013]

【Example】

 An embodiment of this invention will be described below with reference to FIGS. The same parts as those of the conventional example shown in FIGS. 4 to 6 are given the same reference numerals and the description thereof will be omitted.

As shown in the figure, the cage 6 incorporated inside the outer ring 3 has a pair of holding claws 8 provided on one side surface of the annular portion 7 at equal intervals in the circumferential direction. Pockets 9 are formed between the holding claws 8 and the balls 5 are incorporated in the pockets 9.

A plurality of grease reservoirs 12 are provided on the other side surface of the annular portion 7 at predetermined intervals in the circumferential direction, and each grease reservoir 12 is filled with grease G.

When the grease G is filled in the grease reservoir 12, it is filled from the end side of the shaft 1. After the grease is filled, a seal 13 is incorporated at the end of the inner ring surface of the outer ring 3 to prevent dust from entering the bearing.

As described above, by filling the grease reservoir 12 with the grease G, the oil component of the grease G flows into the raceway grooves 2 and 4 to lubricate the rolling surface of the ball 5.

On the other hand, components of the grease other than the oil component are retained in the grease reservoir 12 and prevented from adhering to the outer peripheral surface of the shaft 1.

[0019]

[Effect of the device]

 As described above, in the shaft unit bearing according to the present invention, since the grease reservoir provided in the retainer is filled with grease, only the oil component necessary for lubrication can enter the ball rolling surface. Therefore, the grease hardly adheres to the shaft, and the shaft can be rotated with extremely high accuracy without causing uneven rotation of the shaft.

[Brief description of drawings]

FIG. 1 is a sectional view of an assembled state of a shaft unit bearing according to the present invention.

FIG. 2 is a side view of the same cage.

FIG. 3 is a perspective view showing a part of the same cage.

FIG. 4 is a sectional view showing a conventional shaft unit.

FIG. 5 is a side view showing a conventional bearing.

FIG. 6 is a sectional view taken along line VI-VI in FIG.

[Explanation of symbols]

 1 Shaft 3 Outer ring 5 Ball 6 Cage 7 Annular part 8 Holding claw 9 Pocket 12 Grease reservoir

Claims (1)

[Scope of utility model registration request] 1. An outer ring provided on the outer side of a shaft having a raceway groove, a plurality of balls incorporated between the raceway groove formed on the inner diameter surface of the outer ring and the raceway groove of the shaft, and a retainer for holding the balls. The cage comprises a pair of holding claws provided on one side surface of the annular portion at equal intervals in the circumferential direction,
A shaft unit bearing having a structure in which a pocket is formed between the pair of holding claws, wherein a grease reservoir is provided on the other side surface of the annular portion of the retainer, and the grease reservoir is filled with grease. .