JP2021156322A - Rolling bearing and bearing device - Google Patents

Abstract

To prevent intrusion of contamination from a conductive member to the inside of a bearing, in a rolling bearing including the conductive member such as a metallic brush.SOLUTION: A rolling bearing 1 includes: an inner ring 7 having an inner ring raceway surface 6 on an outer peripheral surface 5; an outer ring 4 having an outer ring raceway surface 3 on an inner peripheral surface 2; and a plurality of rolling elements 8 rollably held between the inner ring raceway surface 6 and the outer ring raceway surface 3, and further includes a conductive member 50 incorporated in a bearing device, having an axial width of the outer ring 4 wider than an axial width of the inner ring 7, and extended from an axial end portion at a side not opposed to the inner ring 7 of the outer ring 4 to an outer peripheral surface 21 of a shaft 20 of the bearing device electrically connected to the inner ring 7, so as to electrically conduct the outer ring 4 and the shaft 20.SELECTED DRAWING: Figure 1

Description

The present invention relates to rolling bearings and bearing devices.

Photosensitive drums of general information equipment, for example, copying machines, are repeatedly charged with static electricity and removed from static electricity in order to display an image. Specifically, first, the surface of the photosensitive drum is charged with static electricity by a charging electrode, and then the image of the original is exposed to the surface of the photosensitive drum by a lamp and an optical system. As a result, the static electricity in the exposed portion (white background portion of the document) is eliminated by the light, and the charged state of the image portion remains as it is. Next, when toner is supplied to the surface of the photosensitive drum, the toner adheres to the charged portion of the surface of the photosensitive drum and an image appears. The toner adhering to the surface of the photosensitive drum is transferred to the copying paper by the transfer electrode, and the toner (image) transferred to the copying paper is fixed to the copying paper by heat and pressure and discharged. On the other hand, in order to prepare for the next copy, the static electricity charged on the surface of the photosensitive drum is eliminated by the static electricity elimination electrode.

While repeating such charging and static electricity removal, the photosensitive drum is charged with static electricity. Rolling bearings are directly connected to the photosensitive drum, but when an electric current flows through the contact area between the raceway ring and the rolling element, it sparks through a thin lubricating oil film, and the surface is locally melted and becomes uneven, that is, electricity. It is known that food will occur. As a countermeasure, for example, as shown in Patent Document 1, it is widely practiced to energize the inner ring and the outer ring by using a conductive member such as a metal brush.

Microfilm of Jitsugyo Hei 02-50355 (Jitsukaihei 04-8820)

One end of a conductive member such as a metal brush is attached to the inner peripheral surface of the outer ring, hangs down toward the inner ring, and the other end is attached so as to be in sliding contact with the outer peripheral surface of the inner ring. Therefore, there is a problem that the distance between the conductive member and the raceway surface is short, and contamination from the conductive member invades the inside of the bearing to deteriorate the lubrication performance.

The present invention has been made in view of such a situation, and an object of the present invention is to prevent contamination from a conductive member from entering the inside of a rolling bearing provided with a conductive member such as a metal brush. ..

The above problems are solved by the following rolling bearings and bearing devices according to the present invention.
(1) An inner ring having an inner ring raceway surface on the outer peripheral surface, an outer ring having an outer ring raceway surface on the inner peripheral surface, and a plurality of rolling elements rotatably held between the inner ring raceway surface and the outer ring raceway surface. In a rolling bearing that is equipped with and is incorporated in a bearing device.
The axial width of the outer ring is wider than the axial width of the inner ring.
The outer ring and the shaft are electrically connected by extending from the axial end of the outer ring on the side that does not face the inner ring to the outer peripheral surface of the shaft of the bearing device that is electrically conductive with the inner ring. A rolling bearing characterized by being provided with a conductive member that conducts conduction.
(2) With the rolling bearing described in (1) above,
With the shaft fitted to the inner ring of the rolling bearing,
A housing that fits into the outer ring of the rolling bearing,
A bearing device comprising.
(3) An inner ring having an inner ring raceway surface on the outer peripheral surface, an outer ring having an outer ring raceway surface on the inner peripheral surface, and a plurality of rolling elements rotatably held between the inner ring raceway surface and the outer ring raceway surface. In a rolling bearing that is equipped with and is incorporated in a bearing device.
The axial width of the inner ring is wider than the axial width of the outer ring.
The inner ring and the housing are electrically connected by extending from the axial end of the inner ring on the side that does not face the outer ring to the inner peripheral surface of the housing of the bearing device that is electrically conductive with the outer ring. A rolling bearing characterized by being provided with a conductive member that conducts the bearing.
(4) With the rolling bearing described in (3) above,
A shaft that fits into the inner ring of the rolling bearing,
The housing that fits into the outer ring of the rolling bearing and
A bearing device comprising.

According to the present invention, in a rolling bearing provided with a conductive member such as a metal brush, it is possible to prevent contamination from the conductive member from entering the inside of the bearing.

FIG. 1 is a cross-sectional view showing a first embodiment of a rolling bearing according to the present invention. FIG. 2 is a cross-sectional view showing a second embodiment of the rolling bearing according to the present invention. FIG. 3 is a cross-sectional view showing a third embodiment of the rolling bearing according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

(First Embodiment)
FIG. 1 is a cross-sectional view showing a first embodiment of a rolling bearing according to the present invention. As shown in the figure, the rolling bearing 1 includes an inner ring 7 having an inner ring raceway surface 6 on the outer peripheral surface 5 and an outer ring 4 having an outer ring raceway surface 3 on the inner peripheral surface 2, and the inner ring raceway surface 6 and the outer ring. A plurality of rolling elements 8 are rotatably held between the raceway surface 3 and the raceway surface 3 by a cage 9. The rolling bearing 1 shown in the drawing is an angular bearing in which the outer peripheral surface 5 including the inner ring raceway surface 6 of the inner ring 7 is inclined. Further, the gap between both ends of the inner ring 7 and the outer ring 4 is closed by a pair of seals 10 and 10, and grease or lubricating oil (not shown) is provided in the bearing space formed by the seals 10 and 10 and the rolling element 8. ) Is enclosed. Although the pair of seals 10 and 10 in FIG. 1 show a contact type having substantially no gap between the inner ring 7 or the outer ring 4 and the seal 10, the inner ring 7 or the outer ring 4 and the seal It may be a non-contact type having a predetermined gap between it and 10.

The shaft 20 of the bearing device is fitted to the inner ring 7, and the present embodiment is an inner ring rotation type in which the inner ring 7 rotates with the rotation of the shaft 20. Further, the outer ring 4 is fitted to the housing 30 of the bearing device. In this way, the rolling bearing 1 is incorporated in a state of being fitted between the shaft 20 of the bearing device and the housing 30. Further, the inner ring 7 is fitted with the shaft 20, so that the inner ring 7 and the shaft 20 are electrically conductive.

In the present embodiment, the axial width of one of the outer rings 4 (on the right side in the example of FIG. 1) is wider than the axial width of the inner ring 7, and the axial direction of the outer ring 4 is not facing the inner ring 7. A disk-shaped conductive member 50 is attached to the end portion, that is, in the vicinity of the side end surface 40. As shown, the conductive member 50 extends from the axial end portion so that the end portion 51 is in contact with the outer peripheral surface 21 of the shaft 20. Therefore, for example, when static electricity (leakage current) generated in the housing 30 flows to the contact portion between the outer ring raceway surface 3 and the rolling element 8 in the rolling bearing 1, the outer ring 4 conducts to the shaft 20 through the conductive member 50. The static electricity is removed. As the conductive member 50, the same metal brush as the conventional one can be used, but as other members, for example, a seal using conductive rubber may be used. Further, the conductive member 50 may be attached to the side end surface 40 by a method such as adhesion or screwing.

Further, the end portion 51 of the conductive member 50 and the outer peripheral surface 21 of the shaft 20 generate wear debris from the end portion 51 of the conductive member 50 as the shaft 20 rotates, which becomes contamination and becomes a pair. There is a concern that it may enter the inside of the bearing through the seals 10 and 10. However, in the present embodiment, since the conductive member 50 is provided at the axial end portion (near the side end surface 40) on the side of the outer ring 4 which is wider in the axial direction than the inner ring 7 and does not face the inner ring 7, the conductive member 50 is provided. Because the end portion 51 is separated from the inner ring 7 and the seals 10 and 10, and there is a sufficient distance between the inner ring 7 and the seals 10 and 10 and the end portion 51 of the conductive member 50 where wear debris can be generated. , It is possible to prevent wear debris from entering the inside of the bearing. The distance L to the mounting position of the outer ring 4 of the conductive member 50 on the inner peripheral surface 2 (for convenience, the axial center position C of the conductive member 50 is defined in FIG. 1) is the distance L of the inner ring 7. The farther away from the side end surface 70 is, the more preferable it is, and it is appropriately determined in consideration of the width of the entire bearing and the like.

When the conductive member 50 is a seal using the above-mentioned conductive rubber, the rolling bearing 1 can be combined with the above-mentioned seals 10 and 10 to form a double seal structure, and the conductive member 50 can be used. It is possible to prevent contamination from entering the bearing and to secure the sealing property inside the bearing.

(Second Embodiment)
In the first embodiment described above, the single row rolling bearing 1 has been described, but the present invention can also be applied to a multi-row rolling bearing. The combined bearing 100 can be used.

In the illustrated combination bearing 100, in the rolling bearing 1 shown in FIG. 1, the side (left side) opposite to the side (right side) to which the conductive member 50 of the outer ring 4 is attached is also made wider than the inner ring 7 in the same manner. Two outer rings 4A and 4B are arranged side by side. Then, similarly to the rolling bearing 1 shown in FIG. 1, the conductive member 50 is attached to the axial end of the outer ring 4A on one side (right side in the drawing) so as to be in sliding contact with the outer peripheral surface 21 of the shaft 20. The outer ring 4B is juxtaposed on the side (left side in the drawing) to which the conductive member 50 of the outer ring 4A is not attached. The other members, the rolling element 8, the cage 9, and the seal 10, can be the same as those in the first embodiment, and "A" and "B" are added to the respective symbols to indicate the rolling element. 8A, 8B, cages 9A, 9B or seals 10A, 10B. Further, in the example shown in FIG. 2, the conductive member 50 is attached only to the axial end portion of the outer ring 4A so as to be in sliding contact with the outer peripheral surface 21 of the shaft 20, but also at the axial end portion of the outer ring 4B. , The conductive member 50 may be attached so as to be in sliding contact with the outer peripheral surface 21 of the shaft 20.

The inner ring 7 has two rows (6A, 6B) of inner ring raceway surfaces so as to correspond to the outer ring raceway surfaces 3A, 3B of the two outer rings 4A, 4B. Further, both outer rings 4A and 4B are widened on both sides in the axial direction, and the total of the portion where both outer rings 4A and 4B are in contact with each other, that is, the portion of the outer ring 4A on the outer ring 4B side and the portion of the outer ring 4B on the outer ring 4A side. A flat portion is formed by extending the central portion 71 of the outer peripheral surface 5 of the inner ring 7 according to the width.

The combination bearing 100 is suitable for applications in which a higher load is applied than the single row rolling bearing 1. As the combination bearing 100, for example, Japanese Patent Application Laid-Open No. 2014-20481 can be referred to, and the load-bearing performance of various industrial machines is enhanced to increase the speed and reduce the size. Also in this case, the static electricity generated in the combination bearing 100 is conducted from the outer ring 4A to the shaft 20 through the conductive member 50 to eliminate static electricity, and at that time, the wear debris from the conductive member 50 is prevented from entering the inside of the bearing. Can be done.

In addition to the two-row back combination bearing 100, the conductive member 50 can be similarly attached to a more multi-row (three-row, four-row, etc.) rolling bearing.

(Third Embodiment)
In the above first embodiment, the outer ring 4 is widened in the axial direction and the conductive member 50 is attached, but it is also possible to widen the inner ring 7 in the axial direction and attach the conductive member 50. In the present embodiment, as shown in FIG. 3, the axial width of one of the inner rings 7 (the right side in the example of FIG. 3) is wider than the axial width of the outer ring 4, and the outer ring 4 in the inner ring 7 The conductive member 50 is attached to the axial end portion on the side not facing the surface, that is, in the vicinity of the side end surface 70. As shown, the conductive member 50 extends from the axial end portion so that the end portion 51 is in contact with the inner peripheral surface 31 of the housing 30. Therefore, for example, when static electricity (leakage current) generated in the shaft 20 flows to the contact portion between the inner ring raceway surface 6 and the rolling element 8 in the rolling bearing 1, the inner ring 7 conducts to the housing 30 through the conductive member 50. The static electricity is removed.

Further, the end portion 51 of the conductive member 50 and the inner peripheral surface 31 of the housing 30 generate wear debris from the end portion 51 of the conductive member 50 as the housing 30 rotates, which becomes contamination. There is a concern that it may enter the inside of the bearing through the pair of seals 10 and 10. However, in the present embodiment, since the conductive member 50 is provided at the axial end portion (near the side end surface 70) of the inner ring 7 which is wider in the axial direction than the outer ring 4 and which does not face the outer ring 4, the conductive member 50 is provided. Because the end portion 51 is separated from the outer ring 4 and the seals 10 and 10, and there is a sufficient distance between the outer ring 4 and the seals 10 and 10 and the end portion 51 of the conductive member 50 where wear debris can be generated. , It is possible to prevent wear debris from entering the inside of the bearing.

In the present invention, the type of rolling bearing 1 is not limited, and the rolling element 8 can be applied to a cylindrical bearing, for example, a roller, other than the ball shown in the above embodiment. The present invention also includes a bearing device including various rolling bearings 1 described above, a shaft 20 that fits into the inner ring 7 of the rolling bearing 1, and a housing 30 that fits into the outer ring 4 of the rolling bearing 1. ..

1 Rolling bearing 2 Inner ring surface 3, 3A, 3B Outer ring raceway surface 4, 4A, 4B Outer ring 5 Outer ring surface 6, 6A, 6B Inner ring raceway surface 7 Inner ring 8, 8A, 8B Rolling element 9, 9A, 9B Cage 10, 10A, 10B Seal 20 Axis 21 Axis outer surface 30 Housing 31 Housing inner peripheral surface 40 side end surface (outer ring side)
50 Conductive member 51 End 70 Side end face (inner ring side)
100 Combination bearing L Distance to the mounting position of the outer ring of the conductive member on the inner peripheral surface

Claims (4)

An inner ring having an inner ring raceway surface on the outer peripheral surface, an outer ring having an outer ring raceway surface on the inner peripheral surface, and a plurality of rolling elements rotatably held between the inner ring raceway surface and the outer ring raceway surface are provided. And in the rolling bearing incorporated in the bearing device,
The axial width of the outer ring is wider than the axial width of the inner ring.
The outer ring and the shaft are electrically connected by extending from the axial end of the outer ring on the side that does not face the inner ring to the outer peripheral surface of the shaft of the bearing device that is electrically conductive with the inner ring. A rolling bearing characterized by being provided with a conductive member that conducts conduction. The rolling bearing according to claim 1 and
With the shaft fitted to the inner ring of the rolling bearing,
A housing that fits into the outer ring of the rolling bearing,
A bearing device comprising. An inner ring having an inner ring raceway surface on the outer peripheral surface, an outer ring having an outer ring raceway surface on the inner peripheral surface, and a plurality of rolling elements rotatably held between the inner ring raceway surface and the outer ring raceway surface are provided. And in the rolling bearing incorporated in the bearing device,
The axial width of the inner ring is wider than the axial width of the outer ring.
The inner ring and the housing are electrically connected by extending from the axial end of the inner ring on the side that does not face the outer ring to the inner peripheral surface of the housing of the bearing device that is electrically conductive with the outer ring. A rolling bearing characterized by being provided with a conductive member that conducts the bearing. The rolling bearing according to claim 3 and
A shaft that fits into the inner ring of the rolling bearing,
The housing that fits into the outer ring of the rolling bearing and
A bearing device comprising.

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