JP2023030803A - conductive bearing - Google Patents

Abstract

To provide a conductive bearing which can prevent intrusion of oil to a position of a conductive brush, can cope with high-speed rotation, and has high conductivity.SOLUTION: A bearing 100 of the present invention is conductive, and includes an outer ring 104, an inner ring 108, a ball 110 rolling between the outer ring and the inner ring, a conductive brush 118 fixed to the outer ring separately from the ball in the axial direction and sliding with the inner ring, a pair of seals 114, 116 arranged on both sides in the axial direction of the brush, and a through hole 120 penetrating through the pair of the seals.SELECTED DRAWING: Figure 1

Description

The present invention relates to conductive bearings having conductive brushes.

2. Description of the Related Art In recent years, the number of high-voltage components mounted on a single vehicle is increasing due to progress in the development of electric vehicles (EVs) and hybrid vehicles (HVs). As the number of high voltage components increases, so does the electromagnetic interference between components. When electromagnetic interference propagates to an electronic device such as an in-vehicle radio, it can adversely affect the operation of the device as electromagnetic noise. Therefore, at present, there is a demand for electromagnetic noise countermeasures in automobiles and the like in which many high-voltage parts are mounted.

As an example of electromagnetic noise countermeasures, use of bearings installed in various parts of automobiles is under consideration. As a result, a structure capable of removing electromagnetic noise originating from the installation target is realized by enabling the bearing to be energized.

As a conductive bearing that can conduct electricity, by covering the rolling elements that roll between the raceway surface of the inner ring and the raceway surface of the outer ring from the side with a conductive seal, the inner and outer raceways are connected via the conductive seal. It is known to form a circuit passing through and reduce the impedance. However, conductive seals generally only have conductive rubber lips and are poorly conductive.

Patent Literature 1 describes a current-carrying bearing provided with a current-carrying member. This current-carrying bearing includes an outer ring, an inner ring, rolling elements that roll between the outer ring and the inner ring, a retainer that retains the rolling elements at predetermined intervals in the circumferential direction, and a pair of rollers positioned on both sides of the retainer in the axial direction. and a seal.

The conductive member is fixed to the inner peripheral surface of the outer ring on the bearing end side of the seal, and is a member that electrically conducts between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, and connects the spring and the conductive brush. have. The spring is fixed to the inner peripheral surface of the outer ring and has electrical conductivity. The current-carrying brush is biased in the radial direction by a spring, is in sliding contact with the outer peripheral surface of the inner ring, and has electrical conductivity.

However, in this current-carrying bearing, if oil (lubricating oil) enters between the current-carrying brushes and the outer peripheral surface of the inner ring with which the current-carrying brushes are in sliding contact, an oil film is formed and the electrical conductivity is impaired. On the other hand, Patent Literature 1 describes that a contact seal made of an elastic member is fixed to the outer ring stepped portion, and a lip portion is formed on the radially inner end portion of the contact seal so as to be in sliding contact with the inner ring stepped portion. . In other words, the current-carrying bearing of Patent Document 1 has a configuration in which seals are arranged on both sides of the current-carrying brush in the axial direction, thereby possibly reducing the intrusion of oil between the current-carrying brush and the outer peripheral surface of the inner ring. be.

JP 2016-14465 A

However, in the current-carrying bearing of Patent Document 1, when the current-carrying bearing rotates at high speed and the pressure of the lubricating oil rises, the lubricating oil may enter from the seal to the position of the current-carrying brush, resulting in a decrease in conductivity.

SUMMARY OF THE INVENTION In view of such problems, it is an object of the present invention to provide a conductive bearing that prevents oil from entering the position of a conductive brush, is capable of supporting high-speed rotation, and has high conductivity. there is

In order to solve the above problems, a typical configuration of a conductive bearing according to the present invention is a conductive bearing comprising an outer ring, an inner ring, rolling elements that roll between the outer ring and the inner ring, rolling elements A conductive brush that is fixed to one of the outer ring and the inner ring and slides on the other, a pair of seals that are arranged on both sides of the brush in the axial direction, and a through hole that penetrates the pair of seals. and

In the above configuration, by arranging a pair of seals on both sides of the conductive brush in the axial direction, the brush is surrounded by the pair of seals, and furthermore, by providing a through hole penetrating the pair of seals, lubricating oil is dispensed. A pair of seals can be decoupled from hydraulic pressure through the through holes. As a result, according to the above configuration, it is possible to prevent oil from entering the positions of the conductive brushes, to be able to cope with high-speed rotation, and to maintain high conductivity.

Said brush is good in it being a rod-shaped carbon brush. Thus, since the conductive brush is a carbon brush, the impedance is lower and the conductivity is higher than the conductive rubber lip.

Said brush is good in it being a brush which consists of a bundle|flux of an electroconductive fiber. Since the conductive brush is a bundle of conductive fibers, it has a simpler structure and is less likely to break than a carbon brush.

According to the present invention, it is possible to provide a conductive bearing that can prevent oil from entering the position of the conductive brush, can cope with high-speed rotation, and has high conductivity.

It is a figure which illustrates the electrically conductive bearing in embodiment of this invention. FIG. 2 is a diagram showing a main part of the bearing of FIG. 1; 2 is a side view of the bearing of FIG. 1; FIG. 2 is an exploded perspective view of the bearing of FIG. 1; FIG. FIG. 10 is a diagram illustrating a conductive bearing in another embodiment of the invention;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a diagram illustrating a conductive bearing (hereinafter referred to as bearing 100) according to an embodiment of the present invention. In the drawing, a part of the bearing 100 is cut away to show the internal structure. FIG. 2 is a diagram showing a main part of the bearing 100 of FIG. 1. As shown in FIG.

The bearing 100 is a radial ball bearing configured as a single row deep groove ball bearing. The bearing 100 includes an outer ring 104 having a raceway surface 102 on its inner periphery, an inner ring 108 having a raceway surface 106 on its outer periphery, a row of balls 110 as rolling elements, and a retainer 112 . Balls 110 roll between raceway surface 102 of outer ring 104 and raceway surface 106 of inner ring 108 . The retainer 112 is provided between the outer ring 104 and the inner ring 108, and holds the balls 110 to maintain the intervals between the balls 110 and prevent the balls 110 from rubbing against each other.

Bearing 100 further includes a pair of seals 114 , 116 , brushes 118 and through holes 120 . A pair of seals 114 and 116 are spaced apart from the ball 110 in the axial direction (see arrow A in FIG. 1), and have electrical conductivity as well as sealing properties to prevent dust from entering. Note that the axial direction refers to the axial direction of a shaft (not shown) inserted into the inner ring 108 .

Of the pair of seals 114 and 116 , the seal 114 closer to the ball 110 has a metal core 122 and a seal lip 124 . The core bar 122 is fixed to an outer ring stepped portion 125 formed on the inner circumference of the outer ring 104 by, for example, press fitting. The seal lip 124 is a conductive rubber member attached to the metal core 122 and in contact with an inner ring stepped portion 126 formed on the outer circumference of the inner ring 108 .

The seal 116 is arranged farther from the ball 110 than the seal 114 and has a metal core 128 and a seal lip 130 . The core bar 128 is fixed to the outer ring stepped portion 125 of the outer ring 104 by, for example, press fitting. The seal lip 130 is a conductive rubber member attached to the metal core 128 and in contact with the inner ring stepped portion 126 of the inner ring 108 .

The brush 118 is a rod-shaped carbon brush having conductivity, and is spaced apart from the ball 110 in the axial direction. A root 118 a (see FIG. 2) of the brush 118 is attached to a spring 132 . The spring 132 is accommodated and fixed to the core metal 122 of the seal 114 . The brush 118 is urged toward the inner ring stepped portion 126 of the inner ring 108 by the spring 132, and its tip 118b slides on the inner ring stepped portion 126 as shown in FIG.

The conductive brush 118 is indirectly fixed to the outer ring 104 via the spring 132 and the core metal 122 and is slidable on the inner ring step portion 126 of the inner ring 108 . Further, a conducting wire 134 is connected to the brush 118 . This conductor wire 134 is soldered to the metal core 122 of the seal 114 and is flexible so that the brush 118 can move according to the biasing force of the spring 132 .

For this reason, in bearing 100 , not only is current flow between outer ring 104 and inner ring 108 via conductive seals 114 and 116 , but also via core metal 122 of seal 114 , conducting wire 134 and brush 118 . It becomes possible to conduct electricity. Furthermore, since the brush 118 is a rod-shaped carbon brush, it has lower impedance and higher conductivity than the conductive rubber seal lips 124 and 130 . Accordingly, when the bearing 100 is used by being installed in the internal mechanism of an electric vehicle, for example, electromagnetic noise derived from the installation target can be removed.

A pair of seals 114 and 116 are also disposed on both axial sides of the brush 118 as shown in FIG. Further, a groove 136 is formed in the metal core 122 of the seal 114 . A groove 136 is formed at a position facing the metal core 128 of the seal 116, and an O-ring 138 is fitted therein.

In bearing 100, core metals 122 and 128 of a pair of seals 114 and 116 surrounding brush 118 are press-fitted into outer ring stepped portion 125 of outer ring 104, and O-ring 138 is arranged between core metals 122 and 128. . Therefore, in bearing 100 , oil (lubricating oil) present between raceway surface 102 of outer ring 104 on which balls 110 roll and raceway surface 106 of inner ring 108 is less likely to penetrate to brush 118 .

However, if the bearing 100 rotates at a high speed and the pressure of the lubricating oil increases, the lubricating oil enters from between the seal lip 124 of the seal 114 and the inner ring stepped portion 126 of the inner ring 108 and reaches the position of the brush 118. is also assumed. In such a case, an oil film is formed between the tip 118b of the brush 118 and the inner ring stepped portion 126 of the inner ring 108, resulting in low conductivity.

Therefore, in the bearing 100, by providing a through hole 120 passing through the pair of seals 114, 116, lubricating oil passes through the through hole 120, and hydraulic pressure is not applied to the pair of seals 114, 116.

FIG. 3 is a side view of bearing 100 of FIG. FIG. 4 is an exploded perspective view of bearing 100 of FIG. A plurality of through holes 120 are provided at predetermined intervals in the circumferential direction of the seals 114 and 116 as shown in FIG.

Further, as shown in FIG. 4, core metals 122 and 128 of seals 114 and 116 are provided with holes 120a and 120b, respectively. The through hole 120 is formed by press-fitting the core metals 122 and 128 of the seals 114 and 116 into the outer ring stepped portion 125 of the outer ring 104, thereby continuously connecting the holes 120a and 120b provided in the core metals 128 and 128. It will penetrate the seals 114 , 116 .

Thus, in the bearing 100, by arranging the pair of seals 114, 116 on both axial sides of the conductive brush 118, the periphery of the brush 118 is surrounded by the pair of seals 114, 116. By providing a through hole 120 penetrating through 116 , lubricating oil can pass through the through hole 120 and hydraulic pressure can be prevented from being applied to the pair of seals 114 and 116 . Therefore, according to the bearing 100, it is possible to prevent oil from entering the position of the conductive brush 118, to be able to cope with high-speed rotation, and to maintain high conductivity.

In the bearing 100, both the core metals 122 and 128 of the seals 114 and 116 are press-fitted into the outer ring stepped portion 125 of the outer ring 104 to fix the seals 114 and 116 to the outer ring 104, but the present invention is not limited to this. As an example, the outer edge of the core metal 128 of the seal 116 is shaped to be bent toward the seal 114 , and the outer edge is accommodated in the core metal 122 of the seal 114 . It may be attached to gold 122 .

FIG. 5 is a diagram illustrating a conductive bearing (hereinafter referred to as bearing 100A) according to another embodiment of the invention. The bearing 100A differs from the bearing 100 in that it includes a brush 140 made of a bundle of conductive fibers instead of the brush 118, which is a rod-shaped carbon brush.

The brush 140 is fixed to the metal core 122A of the seal 114A and is slidable on the inner ring stepped portion 126 of the inner ring 108. As shown in FIG. Therefore, the bearing 100A does not require the spring 132 and the lead wire 134 connected to the brush 118, and the shape of the metal core 122A of the seal 114A can be simplified. Also, the brush 140 has a simpler structure and is less likely to break than the brush 118, which is a carbon brush. Therefore, the bearing 100A can have a simpler structure than the bearing 100. As shown in FIG.

Furthermore, in the bearing 100A, a pair of seals 114A, 116 are arranged on both axial sides of the conductive brush 140, so that the periphery of the brush 140 is surrounded by the pair of seals 114A, 116, and the pair of seals 114A, 116 are further By providing the penetrating through hole 120, lubricating oil can pass through the penetrating hole 120 so that hydraulic pressure is not applied to the pair of seals 114A and 116. FIG. As a result, the bearing 100A can prevent oil from entering the position of the conductive brush 140, can cope with high-speed rotation, and can maintain high conductivity.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood.

INDUSTRIAL APPLICABILITY The present invention can be used as a conductive bearing having conductive brushes.

Reference Signs List 100, 100A Bearing 102 Outer ring raceway surface 104 Outer ring 106 Inner ring raceway surface 108 Inner ring 110 Ball 112 Cage 114, 114A, 116 Seal 118, 140 Brush , 118a... Base of brush 118b... Tip of brush 120... Through hole 120a, 120b... Hole 122, 122A, 128... Metal core 124, 130... Seal lip 125... Outer ring stepped portion 126... Inner ring stepped portion Portion 132 Spring 134 Wire 136 Groove 138 O-ring

Claims (3)

A conductive bearing,
an outer ring;
inner ring;
a rolling element that rolls between the outer ring and the inner ring;
a conductive brush fixed to one of the outer ring and the inner ring while being spaced from the rolling element in the axial direction and sliding on the other;
a pair of seals positioned on opposite axial sides of the brush;
and a through hole passing through the pair of seals. 2. The conductive bearing according to claim 1, wherein said brush is a rod-shaped carbon brush. 2. The conductive bearing according to claim 1, wherein said brush is a brush made of a bundle of conductive fibers.

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