JPH0650345A - Eccentric bearing unit - Google Patents

Abstract

PURPOSE:To improve sealing performance of a bearing, secure the excellent weight balance and the stable operation, and permit the manufacture in a simple structure at low cost. CONSTITUTION:A pair of flange shaped side wheels 3 and 4 covering the width surfaces on both the sides of a bearing 1 are installed on an eccentric sleeve 2 fitted on the inner periphery of the inner race 5 of a roller bearing 1. These side wheels 3 and 4 are formed so that the parts 3a and 4a on the thick side of the eccentric sleeve 2 are made thinner than the parts 3b and 4b on the thin side. The eccentric sleeve 2 is made so that the outside diameter surface is eccentric for the inside diameter surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric bearing unit for converting rotation of a rotary shaft into eccentric rotation.

[0002]

2. Description of the Related Art Conventionally, in a radial plunger pump which is a hydraulic pressure generation source of an antilock brake for automobiles, an eccentric shaft motor having an eccentric shaft portion 52a on an output shaft 52 as shown in FIG. 6 is used as a drive source thereof. is doing. A normal rolling bearing 53 is attached to the eccentric shaft portion 52a, and the plunger 54 is brought into contact with the outer diameter surface of the outer ring thereof. As a result, the rotation of the output shaft 52 becomes the eccentric rotation of the eccentric amount e of the bearing inner ring, and is converted into the linear reciprocating motion of the plunger 54.

[0003]

However, the brake fluid leaking from the plunger pump deteriorates the rubber seal (not shown) of the bearing 53, or penetrates into the bearing 53 to wash out the grease, which results in the lubricating life. May be affected.

Further, the motor 51 having such an eccentric shaft portion 52a has a problem in that it is expensive because machining of the eccentric shaft portion 52a is difficult and a special part is used. Therefore, an ordinary straight shaft motor is used as the motor 51, and a bearing unit in which a bearing 53 is combined with a sleeve having an eccentric hole has been developed. However, when the eccentric sleeve is used, the weight balance of the bearing unit is deteriorated, so that vibration may occur due to rotation, and it may take time and effort to prevent the vibration, and the structure may be complicated.

An object of the present invention is to provide an eccentric bearing unit which is capable of improving the sealability of a bearing, has a good weight balance, can obtain a stable operation, and has a simple structure and can be manufactured at low cost.

[0006]

In the eccentric bearing unit of the present invention, an eccentric sleeve fitted to the inner circumference of an inner ring of a rolling bearing is provided with a pair of flange-shaped side rings that respectively cover width surfaces on both sides of the bearing. The side wheels are formed in a weight balance such that the portion of the eccentric sleeve located on the thick side is lighter than the portion located on the thin side. The eccentric sleeve has an outer diameter surface eccentric to the inner diameter surface.

In the eccentric bearing unit according to a second aspect of the present invention, the one or both side rings are formed separately from the eccentric sleeve,
The side ring and the eccentric sleeve are formed with a concave portion and a convex portion for phase matching that engage with each other in the circumferential direction.

[0008]

According to the eccentric bearing unit having this structure, since the side wheels on both sides cover the width surface of the rolling bearing, the side wheels provide a sealing effect on the bearing. The side wheels have a weight balance in which the thick side of the eccentric sleeve is lighter than the thin side, so the weight imbalance due to the difference in wall thickness of the eccentric sleeve is compensated for, and the weight balance of the entire unit is balanced. Becomes uniform over the entire circumference. Therefore, stable operation without vibration can be obtained. Further, since the side wheel for improving the sealing property also serves as the means for correcting the weight balance of the eccentric sleeve, it is not necessary to provide another balance correcting means.

According to the second aspect of the present invention, the side ring and the eccentric sleeve engage with each other at the uneven portion, which facilitates the phase matching during assembly and prevents the phase shift during operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. This eccentric bearing unit is a rolling bearing 1
, Eccentric sleeve 2, and a pair of flange-shaped side wheels 3, 4
Composed of and. The rolling bearing 1 comprises a deep groove ball bearing with a seal, and includes an inner ring 5, an outer ring 6, rolling elements 7, a cage 8,
And a rubber seal 9.

The eccentric sleeve 2 has an outer diameter surface eccentric with respect to the inner diameter surface by an eccentric amount E required for driving the pump, and is fitted to the inner circumference of the inner ring 5 of the rolling bearing 1. The side wheel 3 on the left side of the figure is formed integrally with the eccentric sleeve 2, and the molded product of the eccentric sleeve 2 and the side wheel 3 and the side wheel 4 which is a separate body on the right side are made of iron for mechanical structure. Each of them is sintered and molded with a system sintered alloy or the like. The separate side wheel 4 is formed in a ring plate shape and is fixed to the eccentric sleeve 2 in a fitted state, and the fitting surface has a groove-shaped recess 10 that engages with each other.
(FIG. 2B) and the convex portion 11 are formed on the eccentric sleeve 2 and the side ring 4, respectively.

Each of the side wheels 3 and 4 covers a gap between the inner and outer rings 5 and 6 on the width surface of the rolling bearing 1, and has an outer diameter larger than the inner diameter of the outer ring 6. Each side wheel 3, 4
And the axial gap between the bearing outer ring 6 and the bearing outer ring 6 are set to be as small as possible to form a labyrinth seal therebetween. The axial clearance is, for example, about 0.5 to 2 mm. The thickness of each of the side wheels 3 and 4 is formed so that the portions 3a and 4a located on the thick side of the eccentric sleeve 2 are thinner than the portions 3b and 4b located on the thin side.

When this eccentric bearing unit is used in a plunger pump, the motor shaft is fitted to the eccentric sleeve 2 and the tip of the plunger 12 is brought into contact with the outer diameter surface of the outer ring 6 of the rolling bearing 1. . When the eccentric sleeve 2 rotates together with the motor shaft, the rolling bearing 1 eccentrically rotates by the eccentric amount E, and the plunger 12 linearly reciprocates.

The rolling bearing 1 has side rings 3 and 4 on both width surfaces.
Since the labyrinth seal is provided with the brake oil, the brake oil of the plunger pump rarely touches the seal 9, and deterioration of the seal 9 is prevented. Further, it is possible to prevent the brake oil from entering the bearing 1 and washing out the grease. These improve the bearing life. The side wheels 3 and 4 are thin in the circumferential portions 3a and 4a, and
Although 4b is thickened, the unevenness in weight due to the difference in wall thickness of the eccentric sleeve 2 is compensated for, and it becomes uniform over the entire circumference. Therefore, stable pump operation without vibration can be obtained.

Further, since the side wheels 3 and 4 serve both as the sealing means and the weight balance correcting means in this manner, it is not necessary to provide another balance correcting means, the structure is simple and the manufacturing cost is low. Further, since the eccentric sleeve 2 is used, the motor 51 with the eccentric shaft is provided as in the conventional example of FIG.
The cost can be reduced as compared with the case of using.

The one side ring 4 is formed separately from the eccentric sleeve 2 for the convenience of assembly of the unit, but since the concave portion 10 of the eccentric sleeve 2 and the convex portion 11 of the side ring 4 are engaged with each other. , Phase alignment during assembly becomes easy, and phase shift during operation is prevented.

3 and 4 show another embodiment. In this example, both side wheels 3 and 4 are formed separately from the eccentric sleeve 2. The side wheel 3 on the left side of the drawing is an eccentric sleeve 2
It is fixed to the eccentric sleeve 2 by being fitted to the outer circumference and the width surface of the collar portion 2a provided at the end of the. As shown in FIG. 4, the collar portion 2
Flat surfaces 13 serving as engaging recesses are provided on both sides of a so that the phases of the side wheels 3 match.

When both side wheels 3 and 4 are separated from the eccentric sleeve 2, both side wheels 3 and 4 are shown in FIG. 2 (B).
Phase matching may be performed in the recess 10 as described above. In that case, in order to prevent erroneous assembly of the side wheels 3 and 4 on both sides, it is desirable to form two recesses 10 at both ends of the eccentric sleeve 2 so that their phases differ from each other. The phase matching of the side wheels 3 and 4 with respect to the eccentric sleeve 2 can be achieved by various structures other than the projection 10 and the flat surface 13.

FIGS. 5 (A) and 5 (B) each show another embodiment. In the example of FIG. 3A, the side wheel 3 has substantially the same thickness all around, and the protrusion 3c is locally provided. In the example of FIG. 3B, the meat-thief recess 3d is formed in a part of the side wheel 3 in the circumferential direction.
Is provided. Also in the case of the configurations shown in FIGS. 5A and 5B, the weight balance of the side wheel 3 can be varied in the circumferential direction to compensate for the weight imbalance of the eccentric sleeve 2.

In addition to this, the plate thickness of the side ring 3 is the same on the entire circumference,
The weight balance of the side wheel 3 may be made non-uniform by making the material different depending on the circumferential direction portion to cancel the weight imbalance of the eccentric sleeve 2.

[0021]

According to the eccentric bearing unit of the present invention, since the eccentric sleeve fitted in the rolling bearing is provided with the pair of flange-shaped side rings that respectively cover the width surfaces on both sides of the bearing, the sealing performance of the bearing by the side rings is improved. Is improved and the life of the bearing is improved. Further, since the both wheels are formed in a weight balance in which the thick-walled portion of the eccentric sleeve is lighter than the thin-walled portion, the weight imbalance due to the difference in the wall thickness of the eccentric sleeve is compensated, and the overall weight balance is improved. It becomes uniform and therefore the stability of operation is improved. Moreover, since the side wheels serve both as the sealing means and the weight balance correcting means, it is not necessary to provide another balance correcting means, the structure is simple, and the manufacturing cost is low.

In the eccentric bearing unit according to the second aspect, since the side ring and the eccentric sleeve engage with each other at the concave and convex portions, the phase alignment at the time of assembly is facilitated and the phase shift during operation is prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2A is a perspective view of the eccentric sleeve and one side ring, and FIG. 2B is a partial perspective view of the eccentric sleeve.

FIG. 3 is a sectional view of another embodiment of the present invention.

FIG. 4 is a perspective view of the eccentric sleeve.

5 (A) and 5 (B) are sectional views of side wheels according to still another embodiment.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rolling bearing, 2 ... Eccentric sleeve, 3, 4 ... Side ring, 5
... Inner ring, 6 ... Outer ring, 10 ... Recessed portion, 11 ... Convex portion, 12 ... Plunger

Claims (2)

[Claims] 1. A rolling bearing, an eccentric sleeve whose outer diameter surface is eccentric with respect to an inner diameter surface and is fitted to the inner circumference of an inner ring of the rolling bearing, and width surfaces on both sides of the rolling bearing provided on the eccentric sleeve. An eccentric bearing unit having a pair of flange-shaped side wheels that respectively cover the eccentric sleeves, the side wheels being formed in a weight balance such that a portion located on the thick side of the eccentric sleeve is lighter than a portion located on the thin side. . 2. At least one of the side wheels is formed separately from the eccentric sleeve, and the side wheel and the eccentric sleeve of the separate body are engaged with each other in the circumferential direction so as to have a phase-adjusting recess and projection. The eccentric bearing unit according to claim 1, wherein a portion is formed.