JP2015117804A - Angular ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angular ball bearing capable of holding a sufficient amount of grease at an outer ring side of a cage, and reducing manufacturing costs.SOLUTION: An angular ball bearing 100 includes an inner ring 2, an outer ring 1, a plurality of balls 3 disposed between the inner ring 2 and the outer ring 1, a cage 4 having a plurality of pockets 4 for rollably accommodating the plurality of balls 3, seals 5, 6 mounted on both ends in the width direction of the inner ring 2 or the outer ring 1, and grease disposed in a space formed by the inner ring 2, the outer ring 1, the balls 3, the cage 4 and the seals 5, 6. The cage 4 is provided with a recessed groove 44 extended in the circumferential direction while including the entire outer edge of the pockets 41, at its outer peripheral side.

Description

The present invention relates to an angular contact ball bearing in which non-contact seals are attached to both ends in the width direction and grease is sealed inside.

2. Description of the Related Art In recent years, angular ball bearings with a seal in which grease is sealed in advance and sealed with a seal are used as angular ball bearings that rotatably support a main shaft of a machine tool. In an angular ball bearing having standard bearing dimensions, for example, about 15 to 30% of the space volume of grease is sealed in a bearing space between an inner ring and an outer ring surrounded by a seal.

In such a sealed angular contact ball bearing, since the grease life can be improved by increasing the amount of grease, the grease is often sealed between the counter bore of the inner ring and the cage. However, in this grease sealing method, when centrifugal force acts on the grease as the inner ring rotates, the grease sticks to the inner ring side of the cage, and the base oil in the grease may not be sufficiently supplied to the outer ring side. When the amount of base oil supplied to the outer ring side is insufficient, it is difficult to maintain a good lubrication state between the rolling element and the transfer surface or between the cage and the inner peripheral surface of the outer ring for a long period of time. .

  Patent Document 1 proposes providing a grease storage groove as a lubricant supply mechanism on the inner peripheral surface of the outer ring in order to enable the grease to be held on the outer ring side of the cage. With such a configuration, the lubricating oil from the lubricant supply mechanism contributes to the lubrication of the cage guide surface portion of the inner peripheral surface of the outer ring, so that generation of cage noise can be suppressed. Further, it is difficult for the grease to scatter from the grease storage groove to the outside, so that it is possible to maintain a good lubrication state and to increase the speed of the angular ball bearing.

  In addition, as a lubricant supply mechanism, a grease retaining groove is provided on the inner diameter surface (inner circumferential surface) of the cage to store grease in a radially outward direction, and the outer diameter surface (outer circumferential surface) of the cage is provided from the grease retaining groove. And forming a through hole through which the base oil of the grease passes. In this configuration, grease is held on the inner ring side of the cage, but centrifugal force is applied to the grease by rotation of the cage, so that the base oil of the grease is separated, and the cage is gradually released from the through hole of the cage. The outer diameter surface of the outer ring and the inner peripheral surface of the outer ring are moved. Since this base oil contributes to lubrication, the generation of cage noise can be suppressed. Further, since a part of the base oil is supplied to the outer ring raceway surface, the angular ball bearing can be speeded up.

JP 2008-286296 A

  However, in the method of providing a grease storage groove on the inner peripheral surface of the outer ring in Patent Document 1, the depth of the raceway surface of the outer ring becomes shallow, so that the rolling element and outer ring raceway surface when a load is applied to the angular ball bearing A part of the contact ellipse between the outer ring and the outer ring races out from the outer ring raceway surface, and the load support may be insufficient. Further, when the grease storage groove is shallow, there is a problem that it becomes difficult to hold the grease itself in the grease storage groove.

  In addition, the method of providing a grease retaining groove on the inner diameter surface (inner circumferential surface) of the cage requires a through-hole that allows the inner circumferential surface and outer circumferential surface of the cage to communicate with each other. Will improve. Further, since the grease remains held on the inner peripheral surface side of the cage, the base oil in the grease may be discharged to the outside at an early stage when centrifugal force is applied.

  The present invention has been made in view of these problems, and an object thereof is to provide an angular contact ball bearing that can hold a sufficient amount of grease on the outer ring side of the cage, reduce the manufacturing cost, and extend the bearing life. It is to be.

The above object of the present invention can be achieved by the following constitution.
(1) inner ring,
Outer ring,
A plurality of rolling elements disposed between the inner ring and the outer ring;
An annular retainer having a plurality of pockets for freely rolling the plurality of rolling elements;
Seals attached to both ends of the inner ring or the outer ring in the width direction;
A grease disposed in a space formed by the inner ring, the outer ring, the ball, the cage, and the seal;
An angular contact ball bearing in which a concave groove extending in the circumferential direction including the entire outer edge of the pocket is formed on the outer peripheral side of the cage.
(2) The angular contact ball bearing according to (1), wherein the inner peripheral surface of the outer ring is inclined so as to have a larger diameter toward the center in the outer ring width direction.
(3) The angular contact ball bearing according to (1) or (2), wherein grease is held in the concave groove.

  According to the angular ball bearing of the present invention, a concave groove extending in the circumferential direction including the entire outer edge of the pocket is formed on the outer peripheral side of the cage, thereby holding a sufficient amount of grease on the outer peripheral side of the cage. It becomes possible to do. In addition, the grease held on the outer periphery of the cage is blown outward by the centrifugal force acting on the cage rotation and sticks to the inner periphery of the outer ring. By supplying the lubricating oil to the peripheral surface, the service life of the angular ball bearing can be extended.

It is sectional drawing which shows the angular ball bearing of one Embodiment of this invention.

  Embodiments of the present invention will be described below. As shown in FIG. 1, the angular ball bearing 100 of this embodiment includes an outer ring 1, an inner ring 2, a ball 3, a cage 4, and non-contact seals 5 and 6.

  The outer ring 1 has an annular shape, and a pair of outer ring inner peripheral surfaces 11 and 11 for guiding the retainer 4 by contacting the outer ring raceway surface 10 and the outer peripheral surface 43 of the retainer 4 on the inner peripheral surface (see FIG. , Only one of them is given a symbol), and a pair of inclined surfaces 12, 12 between the outer ring raceway surface 10 and the pair of outer ring inner peripheral surfaces 11, 11 (only one is given a sign in the figure). ) And are formed. A pair of inclined surfaces 12 and 12 incline so that it may become a large diameter toward the center part of the outer ring | wheel width direction (left-right direction of FIG. 1).

  The inner ring 2 is also annular, and an inner ring raceway surface 20 is formed on the outer peripheral surface. The groove shoulder on one side in the width direction of the inner ring 2 (the right side in FIG. 1) is dropped to form a counter bore 21. That is, both sides of the inner ring 2 across the inner ring raceway surface 20 are counter bores 21 and shoulders 22. The width dimension of the outer ring 1 is smaller than the width dimension of the inner ring 2, and the width direction end of the shoulder 22 of the inner ring 2 protrudes from the width direction end of the outer ring 1.

  A plurality of balls 3 as rolling elements are arranged between the outer ring raceway surface 10 and the inner ring raceway surface 20 in the bearing circumferential direction.

  The cage 4 is made of an annular body having a predetermined thickness, and is obtained, for example, by melt-molding a resin composition (polyether ether ketone (PEEK) and carbon fiber content of 30% by mass). Is. The cage 4 is provided with a plurality of pockets 41 formed as holes penetrating in the radial direction for accommodating the balls 3 at substantially equal intervals in the circumferential direction. By being accommodated in the pocket 41, the balls 3 are arranged with substantially equal intervals in the circumferential direction.

  Further, a concave groove 44 is formed on the outer peripheral side of the cage 4 so as to include the entire circumference of the pocket outer edge 42, and the grease 7 can be held in the concave groove 44. A flat surface 45 is secured between both ends of the pocket 41 in the bearing width direction and both ends of the concave groove 44 in the width direction, and the grease 7 can be held not only between the pockets 41 but also on the flat surface 45. Yes. FIG. 1 shows a state in which the grease 7 is sealed and held in the concave groove 44.

  Note that the grease 7 is held in the concave groove 44 when the grease 7 is sealed and held in the concave groove 44 from the beginning of the bearing assembly, or when the grease is initially sealed in other than the concave groove 44. In some cases, this is brought into the concave groove 44 and held during operation of the bearing.

  The non-contact seals 5 and 6 are formed by pressing a metal plate, and are attached to attachment grooves 15 and 16 formed at both ends in the width direction of the outer ring 1. This prevents the grease 7 disposed in the space formed by the inner ring 2, the outer ring 1, the ball 3, the cage 4, and the seals 5 and 6 from leaking outside.

  Next, the operation will be described.

  The angular ball bearing 100 of the present embodiment is used in so-called inner ring rotation in which the inner ring 2 is attached to a rotating shaft (not shown) and the outer ring 1 is fixed to a housing (not shown). Along with the rotation of the inner ring, the ball 3 that is in rolling contact with the inner ring 2 and the cage 4 that accommodates the ball 3 in the pocket 41 also rotate following the rotation. When the rotational speed of the cage 4 is increased, the grease 7 held in the concave groove 44 is blown outward by centrifugal force and is stuck to the inner peripheral surface 11 and / or the inclined surface 12 of the outer ring.

  On the other hand, since the outer ring 1 is fixed to the housing, no further centrifugal force acts on the grease 7 attached to the outer ring 1. Therefore, the outer ring raceway surface 10 and the outer ring inner peripheral surface 11 are kept in a good lubrication state for a long time by the lubricating oil (base oil) supplied by oozing out from the grease 7. In particular, when the pair of inclined surfaces 12 and 12 are formed adjacent to the outer ring raceway surface 10 as in the present embodiment, the lubricating oil is supplied to the outer ring raceway surface 10 more efficiently. Thereby, the angular ball bearing 100 can be rotated at high speed over a long period of time.

  Note that the pair of inclined surfaces 12 and 12 are for providing a lubrication state more efficiently, and the load support side (right side in FIG. 1) is not an inclined surface, and ensures a contact ellipse. Also, the outer ring raceway surface can be brought into a lubricated state by making the inner ring surface of the outer ring as it is as a flat surface extended to the outer ring raceway surface in the center in the width direction, or by making both surfaces flat instead of both inclined surfaces. Can do.

  As described above, according to the angular ball bearing 100 of this embodiment, by allowing sufficient grease 7 to be held in the concave groove 44, the angular ball bearing 100 can be rotated at a high speed over a long period of time.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, the rolling element may be a roller instead of a ball. In addition, the grease may be sealed not only at the outer side in the cage width direction of the balls, but also at the center portion or both end portions in the cage width direction between adjacent pockets. Furthermore, it may be enclosed between the counterbore of the inner ring and the cage.

DESCRIPTION OF SYMBOLS 1 Outer ring 10 Outer ring raceway surface 11 Outer ring inner peripheral surface 12 Inclined surface 2 Inner ring 20 Inner ring raceway surface 21 Counter bore 22 Shoulder part 3 Ball 4 Cage 41 Pocket 42 Pocket outer edge 43 Cage outer peripheral surface 44 Concave groove 5 Non-contact seal 6 Non Contact seal 100 Angular contact ball bearing

Claims (3)

Inner ring,
Outer ring,
A plurality of rolling elements disposed between the inner ring and the outer ring;
An annular retainer having a plurality of pockets for freely rolling the plurality of rolling elements;
Seals attached to both ends of the inner ring or the outer ring in the width direction;
A grease disposed in a space formed by the inner ring, the outer ring, the ball, the cage, and the seal;
The angular ball bearing according to claim 1, wherein a concave groove extending in a circumferential direction including all outer edges of the pocket is formed on the outer peripheral side of the cage.   The angular contact ball bearing according to claim 1, wherein the inner peripheral surface of the outer ring is inclined so as to have a larger diameter toward the center in the outer ring width direction. The angular ball bearing according to claim 1, wherein grease is held in the concave groove.

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