JP2021134812A - Bearing with seal - Google Patents

Abstract

To provide a bearing with a seal which enables a solid lubricant to be applied to a contact type seal, can inhibits wear of the contact type seal during high speed long time rotation, and can inhibit deterioration of conductivity.SOLUTION: According to a structure of a retainer (a bearing 100) for a bearing of the invention, in a bearing with a seal which includes a seal, a seal 110 includes: an outer ring side washer 114 which is fixed to an outer ring 104 and does not contact with an inner ring 102; an inner ring side washer 112 which is fixed to the inner ring 102 and does not contact with the outer ring 104; and a solid lubricant 116 which is retained by one of the outer ring side washer 114 and the inner ring side washer 112 and contacts with the other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sealed bearing with a seal.

Lubricants used for bearings are generally low-viscosity lubricating oils and high-viscosity semi-solid greases, but solid lubricants (molded greases) that are thermally solidified and molded into a predetermined shape are also used. In some cases. For example, Patent Document 1 discloses a crown-type cage for rolling bearings in which a metal reinforcing material is embedded inside a crown-type cage made of a solid-lubricating composite material composed of a solid lubricant and a metal or alloy. .. According to Patent Document 1, stable rotation performance can be maintained for a long period of time in a special environment where grease or oil cannot be used.

By the way, the bearing may be provided with a seal to prevent foreign matter from entering and to enclose a lubricant. There are two types of seals, contact type and non-contact type. In the contact type seal, a lip is provided on the edge of the tip of the seal to bring it into contact with the other party to improve the sealability.

Further, in recent years, with the progress of development of EV cars (electric cars) and HV cars (hybrid cars), the influence of electromagnetic noise generated from inverters and motors on electronic devices has become a problem. As one means for removing the electromagnetic noise, the impedance of the bearing seal is lowered to release the electromagnetic noise. In the energization type rolling bearing of Patent Document 2, the annular space surrounded by the inner surface of the concave groove formed on the tip of the seal lip over the entire circumference and the side wall surface of the seal groove while making the seal ring conductive. A conductive lubricant is sealed inside.

JP-A-2007-298160 Japanese Unexamined Patent Publication No. 2009-264401

The contact type seal has a problem that the lip is worn and the sealing property is gradually impaired. At this time, if the seal is provided with conductivity, the conductivity will also decrease. The wear of the lip is remarkable when the oil film on the seal lip portion is thin or when the peripheral speed or surface pressure of the lip is high. Also, when contamination (dust) enters the sliding portion of the lip, the wear of the lip increases.

Therefore, instead of the lip, it is conceivable to use a solid lubricant for the contact part of the seal. However, solid lubricants cannot adhere to metals. Therefore, when the bearing rotates at high speed, the solid lubricant may fall off from the core metal of the seal. Then, it becomes impossible to secure the stable rotation performance of the bearing.

The present invention makes it possible to apply a solid lubricant to a contact-type seal, suppress wear of the contact-type seal during high-speed and long-time rotation, and also suppress a decrease in conductivity of a sealed bearing. It is intended to be provided.

In order to solve the above problems, a typical configuration of the bearing cage according to the present invention is a sealed bearing having a seal, in which the seal is fixed to the outer ring and does not come into contact with the inner ring, and an outer ring side washer and an inner ring. It is characterized by containing an inner ring side washer that is fixed to the outer ring and does not come into contact with the outer ring, and a solid lubricant that is held by one of the outer ring side washer and the inner ring side washer and comes into contact with the other.

According to the above configuration, the solid lubricant is structurally retained by the outer ring side washer or the inner ring side washer rather than being adhered. This makes it possible to suitably prevent the solid lubricant from falling off from the seal while using a highly durable solid lubricant instead of the lip for the seal. Therefore, in the bearing, it is possible to suppress the wear of the contact type seal.

It is preferable that the outer ring side washer and the inner ring side washer are made of metal, and the solid lubricant has conductivity. According to such a configuration, the seal has conductivity. Therefore, it is possible to take measures against electromagnetic noise in the bearing. Further, in the solid lubricant, it is the skeleton of the network structure (porous) in which the thickener is solidified that has conductivity. When a liquid lubricant is used, the conductivity decreases due to the carbon chain breaking during high-speed and long-time rotation. On the other hand, since the solid lubricant does not lose its conductivity even if the skeleton is worn during high-speed and long-time rotation, it is possible to suppress a decrease in the conductivity of the contact-type seal.

It is preferable that a groove is formed in one of the outer ring side washer and the inner ring side washer, and the solid lubricant is held in the groove. As a result, the solid lubricant can be suitably held by the outer ring side washer or the inner ring side washer, and the above-mentioned effect can be obtained.

It is preferable that holes are arranged on one of the outer ring side washer and the inner ring side washer, and the solid lubricant is arranged so as to penetrate the hole and protrude to both sides of the hole. Even with such a configuration, the solid lubricant can be suitably held by the outer ring side washer or the inner ring side washer.

The solid lubricant may have a groove formed on the contact surface with the outer ring side washer or the inner ring side washer. As a result, the groove becomes a negative pressure, so that the outer ring side washer or the inner ring side washer and the solid lubricant are in close contact with each other. Therefore, the sealing property of the bearing by the seal can be improved. Further, since the adhesiveness is increased, the conductivity of the seal is also increased, so that even if the solid lubricant is worn, it is possible to maintain high conductivity.

It is preferable that the groove is filled with a liquid lubricant. As a result, friction with the outer ring side washer or the inner ring side washer can be reduced, and the slidability can be improved. Therefore, it is possible to sufficiently secure the sealing performance.

It is preferable that the solid lubricant has a pressure relief hole that leads from the groove to the outside. As a result, it is possible to prevent the groove from becoming a negative pressure. Therefore, it is possible to prevent wear of the solid lubricant and obtain stable sealing performance.

According to the present invention, it is possible to apply a solid lubricant to a contact-type seal, and with a seal capable of suppressing wear of the contact-type seal during high-speed and long-time rotation and suppressing a decrease in conductivity. Bearings can be provided.

It is a figure explaining the bearing with a seal which concerns on 1st Embodiment. It is a figure explaining the bearing with a seal which concerns on 2nd Embodiment. It is a figure explaining other variations of a bearing.

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 such an embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. do.

(First Embodiment)
FIG. 1 is a diagram illustrating a sealed bearing (hereinafter, referred to as a bearing 100) according to the first embodiment. In the present embodiment, the ball is illustrated as an example of the rolling element incorporated in the bearing 100, but the present invention is not limited to this, and the present invention can be applied by using a roller as an example of the rolling element.

As shown in FIG. 1, the bearing 100 of the first embodiment is a single row deep groove ball bearing provided with a row of balls 106 and a cage 108 as rolling elements between the inner ring 102 and the outer ring 104. The bearing 100 has a seal 110 that covers the ball 106 from the side between the inner and outer race wheels, and the seal 110 prevents foreign matter from entering the inside of the bearing 100.

The seal 110 includes an inner ring side washer 112 fixed to the inner ring 102 and not in contact with the outer ring 104, an outer ring side washer 114 fixed to the outer ring 104 and not in contact with the inner ring 102, and a solid lubricant 116. In the present embodiment, the inner ring side washer 112 has a contact surface 112a with the inner ring 102 and a holding portion 112b having a substantially F-shaped cross section. The solid lubricant 116 is held by the holding portion 112b of the inner ring side washer 112 and comes into contact with the outer ring side washer 114.

The material of the solid lubricant 116 is a mixture of grease and resin powder as a thickener. When this material is placed in a mold and maintained at a high temperature equal to or higher than a predetermined value for a while, the resin powder forms a porous network structure to form a skeleton, and can be molded into an arbitrary three-dimensional shape that imitates the mold. At this time, by adding the conductive material (carbon filler), the carbon filler is dispersed in the skeleton and becomes conductive. Since grease is gradually supplied from the network structure of the skeleton, high sliding performance can be obtained over a long period of time.

According to the above configuration, the solid lubricant 116 is held by the inner ring side washer 112. As a result, it is possible to suitably prevent the solid lubricant from falling off from the seal 110 while using the highly durable solid lubricant 116 for the seal. Therefore, in the bearing 100, it is possible to secure stable rotation performance at the time of high-speed rotation. In the present embodiment, the configuration in which the solid lubricant 116 is held by the inner ring side washer 112 is illustrated, but the present invention is not limited to this, and the solid lubricant 116 is held by the outer ring side washer 114. However, the same effect can be obtained.

Further, as shown in FIG. 1, in the present embodiment, the holding portion of the inner ring side washer is composed of an upright surface 112c, a rib 112d, and a flange 112e. The erection surface 112c is erected from the contact surface 112a toward the outer ring 104, and the flange 112e extends from the end of the erection surface 112c toward the outer ring side washer 114. The rib 112d extends from the standing surface 112c toward the washer 114 on the outer ring side on the inner ring 102 side of the flange 112e. As a result, a groove is formed between the rib 112d and the flange 112e, and the ring-shaped solid lubricant 116 is held in the groove. As a result, the solid lubricant 116 can be suitably held by the inner ring side washer 112, and the above-mentioned effect can be surely obtained.

Further, in the present embodiment, the outer ring side washer 114 and the inner ring side washer 112 are made of metal, and the solid lubricant 116 has conductivity. As a result, since the seal 110 has conductivity, it is possible to take measures against electromagnetic noise in the bearing 100.

In particular, it is the skeleton (solidified thickener) that has a three-dimensional shape that has conductivity. Therefore, unlike liquid lubricants, there is no risk of the carbon chain breaking. Even if the end face of the skeleton is worn, the carbon filler dispersed inside is not cut off, so that the conductivity does not decrease. Therefore, it is possible to suppress a decrease in the conductivity of the contact type seal.

(Second Embodiment)
FIG. 2 is a diagram illustrating a sealed bearing (hereinafter, referred to as a bearing 200) according to the second embodiment. FIG. 2A is a cross-sectional view of the bearing 200, and FIG. 2B is a cross-sectional perspective view of the outer ring side washer 214. In FIG. 2B, the left side is a cross-sectional perspective view of only the outer ring side washer 214, and the right side is a cross-sectional perspective view of the outer ring side washer 214 in a state where the solid lubricant 116 is held.

As shown in FIG. 2A, the bearing 200 of the second embodiment illustrates a configuration in which the solid lubricant 116 is held by the outer ring side washer 214. Specifically, of the seal 210, the inner ring side washer 212 has a substantially L-shape including a contact surface 212a and an upright surface 212b. On the other hand, the outer ring side washer 214 has a fixing portion 214a fixed to the outer ring 104, and a facing surface 214b extending from the fixing portion 214a toward the inner ring 102 and facing the erection surface 212b.

As a feature of the present embodiment, as shown in FIG. 2B, the outer ring side washer 214 has a plurality of holes 214c arranged on the facing surface 214b. Then, as shown in FIGS. 2A and 2B, the solid lubricant 116 is arranged (molded) so as to penetrate the hole 214c and protrude from both sides of the hole 214c. Even with such a configuration, the solid lubricant 116 can be suitably held in the seal 210, and the same effect as that of the bearing 100 of the first embodiment can be obtained.

(Other variations)
FIG. 3 is a diagram illustrating other variations of the bearing. In the seal 310a of the bearing 300a shown in FIG. 3A, the solid lubricant 216 is held by the outer ring side washer 114. The structure for holding the solid lubricant 216 is similar to that shown in FIG. At this time, of the solid lubricant 216, a groove 216b is formed on the contact surface 216a that abuts on the inner ring side washer 112. When the bearing 300a rotates and the inner ring side washer 112 and the outer ring side washer 114 move relatively, the inside of the groove 216b becomes a negative pressure, so that the adhesion between the inner ring side washer 112 and the solid lubricant 216 is improved. Therefore, the conductivity of the seal 110 can be improved, and even if the solid lubricant 216 is worn, high conductivity can be maintained.

In the seal 310b of the bearing 300b illustrated in FIG. 3B, the groove 216b formed in the solid lubricant 216 is filled with the liquid lubricant 218. According to such a configuration, friction with the inner ring side washer 112 can be reduced and slidability can be improved. Therefore, it is possible to improve the durability.

In the seal 310c of the bearing 300c illustrated in FIG. 3C, a pressure relief hole 216c communicating with the outside is formed in the groove 216b of the solid lubricant 216. As a result, the generation of negative pressure due to the groove 216b can be suppressed. Therefore, it is possible to prevent the solid lubricant 216 from being worn and improve the durability.

Although 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 clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood.

The present invention can be used as a sealed bearing with a seal.

100, 200, 310a-c ... Bearing, 102 ... Inner ring, 104 ... Outer ring, 106 ... Ball, 108 ... Cage, 110, 210, 310a-c ... Seal, 112 ... Inner ring side washer, 112a ... Contact surface, 112b ... Holding part, 112c ... Standing surface, 112d ... Rib, 112e ... Flange, 114 ... Outer ring side washer, 116 ... Solid lubricant, 212 ... Inner ring side washer, 212a ... Contact surface, 212b ... Standing surface, 214 ... Outer ring side washer, 214a ... fixed part, 214b ... facing surface, 214c ... hole, 216 ... solid lubricant, 216a ... contact surface, 216b ... groove, 216c ... hole, 218 ... liquid lubricant

Claims (7)

In sealed bearings with seals
The seal is
An outer ring side washer that is fixed to the outer ring and does not come into contact with the inner ring,
An inner ring side washer that is fixed to the inner ring and does not come into contact with the outer ring,
A sealed bearing comprising a solid lubricant held by one of the outer ring-side washer and the inner ring-side washer and abutting against the other. The outer ring side washer and the inner ring side washer are made of metal.
The sealed bearing according to claim 1, wherein the solid lubricant has conductivity. A groove is formed in one of the outer ring-side washer and the inner ring-side washer.
The sealed bearing according to claim 1 or 2, wherein the solid lubricant is held in the groove. Holes are arranged on one of the outer ring-side washer and the inner ring-side washer.
The sealed bearing according to claim 1 or 2, wherein the solid lubricant is arranged so as to penetrate the hole and protrude from both sides of the hole. The sealed bearing according to claim 1 or 2, wherein the solid lubricant has a groove formed on the contact surface with the outer ring side washer or the inner ring side washer. The sealed bearing according to claim 5, wherein the groove is filled with a liquid lubricant. The sealed bearing according to claim 5, wherein the solid lubricant is formed with a pressure relief hole leading from the groove to the outside.

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