JPH0544570Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a current-carrying bearing, and more particularly to a radial rolling bearing that allows current to flow between an inner ring and an outer ring that rotate relatively.

Conventional technology and its problems Current-carrying bearings are used in the roller shafts of automated teller machines (ATMs) for transporting banknotes, video tape recorders (VTRs), etc., which require grounding to eliminate static electricity.
Used in automobile steering shafts that require electricity to attach various switches.

As such current-carrying bearings, there are known bearings in which current-carrying grease is sealed between the inner and outer rings, and bearings in which a current-carrying seal is attached between the inner and outer rings. However, these bearings have a problem in that they have a large electrical resistance value and a large deterioration in current carrying performance due to rotation. In addition, especially when using current-carrying grease, there are restrictions on the selection of lubricants, making it difficult to select the optimal lubricant depending on the conditions of use, which poses problems in terms of service life, etc. For this reason, particularly in steering shafts of automobiles, a retaining ring-type brush that is fitted onto the inner circumferential surface of an outer ring and a portion of which slides into contact with the opposite outer circumferential surface of the inner ring is used. However, in the case of this type of bearing, grease or oil accumulates on the sliding contact area between the inner ring and the brush, which increases the electrical resistance value, especially at high speeds, and foreign matter such as dirt enters from the outside, causing the current carrying performance to deteriorate. to degrade. Furthermore, since the brushes are in direct contact with the inner ring, the sliding contact portion is subject to significant wear, which poses a problem in terms of service life.

The purpose of this invention is to solve the above problems and provide a current-carrying bearing with good current-carrying performance and long life.

Means for Solving the Problems The current-carrying rolling bearing according to this invention is provided with sealing plates on both sides of the rolling elements between the inner ring and the outer ring, and on either side of the opposing circumferential surfaces of the inner ring and the outer ring between the rolling elements and the sealing plate. A retaining ring type brush is fitted on one side, and a short cylindrical ring on which a part of this brush comes into sliding contact is fitted on the other side, and the part of this ring that is closer to the rolling element than the part that makes sliding contact with the brush. A barrier is provided on the opposite side and reaches near the opposing circumferential surface, and a lubricant is sealed in a portion closer to the rolling element than the barrier.

Operation: Electricity is transmitted from one of the inner and outer rings to the other through the sliding contact between the brush and the ring. The ring barrier prevents the lubricant on the rolling element side from reaching the brush side and getting on the sliding contact area with the ring. The sealing plate prevents foreign matter from entering.

Embodiment The drawings show an embodiment in which this invention is applied to a single-row deep groove ball bearing.

This bearing mainly includes an inner ring 10, an outer ring 11,
It is composed of rolling elements 12 and a cage 13. Inner ring 10 and outer ring 11 are made of metal such as bearing steel.

Shields 14 are provided at the ends of the outer ring 11 on both sides of the rolling elements 12, respectively, to seal the gap with the inner ring 10.

A shallow annular groove 16 is formed on the inner peripheral surface of the outer ring 11 between the shield 14 and the rolling elements 12 on one side (right side in FIG. 1).
is formed, and a retaining ring type brush 17 is formed in this groove 16.
is held in place by elastic force. A short cylindrical ring 18 is press-fitted onto the outer circumferential surface of the inner ring 10 facing the inner ring 10. The shape of the brush 17 is the same as that of the conventional brush, and both ends thereof are bent inward and come into sliding contact with the outer peripheral surface of the ring 18. A brim-shaped barrier 18a that reaches close to the inner circumferential surface of the outer ring 11 is integrally formed in a portion of the ring 18 that is closer to the rolling element 12 than the portion in sliding contact with the brush 17. Grease or oil is sealed between this barrier 18a and the shield 14 on the opposite side (left side in FIG. 1). The brush 17 is made of metal such as stainless steel or platinum, and the ring 18 is made of metal such as brass or white metal. In addition,
The combination of brush 17 and ring 18 is preferably selected depending on the rotation speed as follows.
For example, for medium-speed rotation where the sliding speed of the brush 17 and ring 18 is 40 m/min or less, the brush 17
It is preferable to use stainless steel for the brush 17 and brass for the ring 18, and use platinum for the brush 17 and white metal for the ring 18 for high-speed rotation where the sliding speed is higher than this.

In the above bearing, electricity is transmitted from one of the inner ring 10 and the outer ring 11 to the other through the sliding contact portion of the brush 17 and the ring 18. At this time, since there is a barrier 18a of the ring 18, the lubricant does not come to the side of the brush 17 and get on the sliding contact part with the ring 18, and because there is a shield 14, foreign substances such as dirt cannot enter. is prevented. Therefore, the brush 17 and the ring 18 are always in direct contact, and the electrical resistance value is small, and the current carrying performance does not deteriorate. By appropriately selecting the materials of the brush 17 and ring 18 as described above, wear resistance can be improved and the life span can be extended. Furthermore, since there are no restrictions on the lubricant as in the case of using electrically conductive grease, it is possible to select the optimum lubricant according to the usage conditions and extend the life.

The ring may have at least a short cylindrical portion that can be fitted into the inner ring or the outer ring and a barrier, and its shape is not limited to that of the above embodiments. Further, although a shield is used as the sealing plate in the above embodiment, a seal may also be used. In addition,
This invention can of course be applied to radial rolling bearings other than single-row deep groove ball bearings.

Effects of the invention Since the current-carrying bearing according to the invention has the above-mentioned configuration, it exhibits excellent effects of good current-carrying performance and long life. In other words, the sealing plate prevents foreign matter from entering, and the ring's barrier prevents lubricant from coming to the brush side and attaching to the sliding contact area with the ring, resulting in low electrical resistance and deterioration of current carrying performance. Nor. Furthermore, since the brush does not come into direct sliding contact with the inner or outer ring, but rather with the ring, the materials for the brush and ring can be freely selected from the viewpoint of wear resistance, which can extend their lifespan. can. Furthermore, there are no restrictions on the lubricant as in the case of using electrically conductive grease, and the life can be extended by selecting an appropriate lubricant.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, and FIG.
FIG. 2 is a longitudinal cross-sectional view of the current-carrying bearing along the line shown in FIG. 1, and FIG. 2 is a cross-sectional view taken along the line shown in FIG. 10... Inner ring, 11... Outer ring, 12... Rolling element, 14... Shield, 17... Brush, 18...
...Ring, 18a...Bulwark.

Claims (1)

[Scope of utility model registration request] Sealing plates 14 are provided on both sides of the rolling element 12 between the inner ring 10 and the outer ring 11, and a retaining ring type is provided on either side of the opposing circumferential surfaces of the inner ring 10 and the outer ring 11 between the rolling element 12 and the sealing plate 14. A brush 17 is fitted, and a short cylindrical ring 18 on which a part of the brush 17 slides is fitted on the other side, and a portion of the ring 18 that is closer to the rolling element 12 than the part of the ring 18 that slides in contact with the brush 17. A current-carrying bearing is provided with a barrier 18a that reaches near the opposite peripheral surface of the other party, and a lubricant is sealed in a portion closer to the rolling element 12 than the barrier 18a.