JPH03181618A - Rolling bearing and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a rolling bearing having highly reliable electrical insulation and vibration isolating function by covering the outer circumferential face and the end faces of an outer ring main body with a coating layer of elastic material turning its terminal ends into circumferential grooves, and further jointing in one body a thin metallic ring body on the outer circumferential face without step difference against the coating layer. CONSTITUTION:The outer circumferential face 9 and the end faces 10 of an outer ring main body 8 are covered with a coating layer 11 of elastic material, and its end parts are formed to turn in circumferential grooves 14. Further, a thin metallic ring body 15 is jointed in one body on the outer circumferential face of the coating layer 11 covering the outer circumferential face 9 of the outer ring main body 8. In this way, the coating layer 11 covering the outer circumferential face of a bearing 1 is prevented to separate off by turning the terminal ends into the circumferential grooves 14, and an important range as a fitting surface is protected with the thin metallic ring body 15. The boundary between the thin metallic ring body 15 and the coating material is flush with each other, hereby, mass production of a rolling bearing having highly reliable electrical insulation and vibration isolating function can be easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides rubber on the surface of at least one of the outer ring and the inner ring for the purpose of electrical insulation and vibration isolation.

The present invention relates to a rolling bearing having a coating layer made of synthetic resin or the like and a method for manufacturing the same.

[Conventional technology]

Generally, ball bearings, 1 cylindrical roller bearings are used in equipment that has electrical equipment around the bearing, such as electric motors, 2 generators, vehicle drive systems, and vehicle bearing systems.

In rolling bearings such as needle bearings, conical bearings, and spherical bearings, electricity may flow to the bearing rings via rolling elements between the bearing rings, which are made up of an outer ring and an inner ring. The contact between the rolling elements and the bearing ring is point contact or line contact, and when current flows through this, electrical discharge occurs between the rolling element and the bearing ring, causing local melting, resulting in wear and tear on the bearing and blackening of the lubricating oil. This may cause the bearing to become unusable before the end of its life.

To prevent this, divine measures have traditionally been taken. For example, Japanese Unexamined Patent Publication No. 10111/1983 proposes a technique in which the circumferential surface of a bearing ring of a rolling bearing is coated with a base film and then coated with plastic to insulate it (first conventional example). ).

Furthermore, Japanese Patent Application Laid-open No. 103023/1983 proposes a technique for forming an insulating film of an inorganic compound by a thermal spraying method (second conventional example). Furthermore, Utility Model 60-161721
No. 61-2454 discloses a technique for forming a ceramic coating impregnated with an organic compound such as a synthetic resin as an insulating coating on the outer surface of a bearing ring (third conventional technique). example).

[Problem to be solved by the invention]

However, among the various countermeasures mentioned above, for example, those that form an exposed rubber or plastic insulating coating on the circumferential surface of the bearing ring, as in the first conventional example, do not protect against the heat applied when the bearing is used, water, kerosene, lubricating oil, etc. There is a problem in that the material of the insulating coating deteriorates due to the effects of other chemicals, etc., either alone or in synergy, which interferes with important functions of the bearing such as load application and fitting.

Furthermore, rubber and plastic coatings are more difficult to process with high precision than metal materials. Therefore, the dimensional accuracy of the fitting surface of the bearing ring, which requires particularly high precision in bearings, is inferior to that of standard steel bearings, resulting in a problem in that the assembly accuracy of the product is reduced.

On the other hand, in the second case described above, an insulating coating made of an inorganic compound or a ceramic coating is formed on the outer surface of the raceway instead of the plastic layer. In the third conventional example, there are few drawbacks such as material deterioration and poor dimensional accuracy, but since the coating itself is brittle, it may be damaged when the bearing is installed or removed from a mating member! I
There was a problem with I and I being easy to live in.

In addition, in the conventional example, the insulation coating was applied to the raceway ring (outer ring).
Because it was formed only on the end face of the outer ring, the bearing was assembled only on the end face of the outer ring and the opposing member (
The creepage distance between the housing and the housing is only the thickness of the coating, and therefore, during use, the grease that contains the metal abrasion powder in the bearing adheres to the inner peripheral edge of the outer ring, causing a sufficient distance between the opposing surfaces. There were also problems such as difficulty in obtaining adequate insulation.

Therefore, the present invention has been made by focusing on the above-mentioned conventional problems, and its purpose is to prevent the important functions of the bearing from being lost and to avoid the risk of reducing the assembly accuracy of the product. The purpose of the present invention is to provide a rolling bearing that does not cause scratches or peeling when the bearing is attached to or removed from a mating member, and has highly reliable electrical insulation and anti-vibration functions, and a method for manufacturing the same. .

[Means to solve the problem]

In order to achieve the above object, the rolling bearing of the present invention has a non-metallic coating layer on the peripheral surface and end surface of at least one of the inner and outer bearing rings on the side opposite to the raceway surface. A circumferential groove is formed by cutting out the edge where the end surface of at least one raceway ring intersects with the circumferential surface on the raceway surface side, and the coating layer is made of an elastic material such as rubber or synthetic resin,
A thin metal ring body is formed to cover the entire peripheral surface and end surface of the raceway ring on the side opposite to the raceway surface, and to wrap around the circumferential groove, and a thin metal ring body is integrally connected to the fitting surface via the coating layer. Moreover, the coating layer and the thin metal ring are smoothly connected to each other without any difference in level.

The covering layer can be formed as an electrically insulating covering layer. Moreover, it can also be formed as a vibration-proof coating layer. Furthermore, it can also be formed as an electrically insulating coating layer and a vibration-proof coating layer.

The method for manufacturing a rolling bearing of the present invention includes disposing one raceway ring having a circumferential groove formed by cutting out the edge where the end face and the raceway side circumferential surface intersect in a mold; A cavity is formed that surrounds the circumferential groove, the end face, and the circumferential surface on the opposite raceway side, and a metal ring body is placed by shallowly fitting into the mold and facing the circumferential surface on the opposite raceway side with a desired gap therebetween. Next, a molding material made of an elastic material such as rubber or synthetic resin is sealed in the cavity and solidified, and after the molded object is removed from the mold, unnecessary protruding parts including the protruding surface of the metal ring are removed. Characterized by deletion.

[Effect]

Of the coating layer made of an electrically insulating elastic material such as rubber or synthetic resin that covers the circumferential surface of the bearing ring, the fitting surface portion that performs important functions is protected by a thin metal ring and is not exposed. Therefore, material deterioration due to hot water, kerosene, lubricating oil, etc. is effectively suppressed, and the important functions of the bearing are maintained over a long period of time without being impaired.

In addition, the outer surface of the mating member, which requires particularly high-precision processing, is made of a thin metal ring rather than rubber or synthetic resin, which is difficult to process with high precision.
Dimensional accuracy equivalent to that of standard steel bearings can be achieved.

In addition, the boundary between the thin metal ring and the above-mentioned coating layer is a flush integral structure, and the entire surface from the fitting surface through the shoulder to the end portion of the bearing end surface is smoothly continuous and has no unevenness. By doing so, it is possible to prevent the bearing from getting caught and being damaged when it is assembled into or removed from a mating member.

In addition, the coating layer covers the entire circumferential surface and end surface of the bearing ring body on the side opposite to the raceway surface, and is further wrapped around the circumferential groove provided on the periphery of the end surface, thereby completely preventing the coating layer from peeling off. can be prevented.

Furthermore, since there is no exposed portion of the metal bearing ring body where it faces the mating member, the possibility of energization can be significantly reduced, and the reliability of insulation performance is high.

In addition, by covering the entire end surface of the bearing ring with an elastic material, it is possible to provide a large vibration damping function against vibrations not only in the radial direction but also in the axial direction.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to an outer ring will be described with reference to the drawings.

1 and 2 show an embodiment of the rolling bearing of the present invention, which is applied to a ball bearing 1 for an electric motor (hereinafter simply referred to as a bearing). Balls 5 as rolling elements held by a retainer 4 are interposed between an outer ring 2 and an inner ring 3, which are raceway rings, and are movable.
The inner ring 3 is fitted to the shaft 7. In this bearing 1, an outer circumferential surface 9, which is the circumferential surface on the side opposite to the raceway surface of the outer ring main body 8, and an end surface 10 following the outer circumferential surface 9 are covered with a non-metallic coating layer 11.

To explain in more detail with reference to FIG. 2, the outer ring main body 8 has a circumferential groove 14 formed by cutting out the circumferential edge where the end surface 10 and the inner circumferential surface 13, which is the circumferential surface on the raceway surface side having the raceway groove 13a, intersect. It is formed. This circumferential groove 14 has a depth of about 2 nm when the outer ring outer diameter of this embodiment is about 170 mm. The non-metallic coating layer 11 covers the outer peripheral surface 9 and end surface 1 of the outer ring main body 8.
0 and is formed to wrap around inside the circumferential groove 14. This covering layer 11 is made of an elastic material such as rubber or synthetic resin, and in this embodiment is made of polyurethane. Its thickness must be at least 0.1 mm to ensure electrical insulation function. If vibration-proofing function is required in addition to insulation function, 11
It is desirable that it be 11111 or more.

However, 2. If it exceeds Otts, the strain on the coating layer 11 will become excessive due to the load applied to the bearing, which is not preferable.

Further, on the outer circumferential surface of the coating layer 11 in a portion covering the outer circumferential surface 9, which is the circumferential surface on the side opposite to the raceway surface of the outer ring body 8, a thin metal ring having a width somewhat narrower than the width of the outer ring body 8 and a thickness of approximately 1 m+a is provided. The body 15 is integrally connected. This thin metal ring 15 is not necessarily an endless ring, but may be a wound ring with ends. The thickness of the coating layer 11 interposed between the thin metal ring 15 and the outer circumferential surface 9 of the outer ring body 8 is, of course, 0.1111111 or more to ensure the electrical insulation function, and in this embodiment, it is 0.5 mm. It is.

Thus, the thin metal ring body 15 is attached to the outer circumferential surface 9 of the outer ring body 8.
embedded flush within the coating layer If that covers the
There is no step at the boundary with the coating layer 11 made of rubber or synthetic resin material. The coating layer 11 extends from the boundary to the bearing end surface 1 via the curved shoulder.
It continues smoothly without any unevenness all the way to the end of 0.

A method of manufacturing the outer ring 2 of the bearing 1 constructed as described above will be described below with reference to FIGS. 3 to 5.

The circumferential groove 14 is previously formed in the outer ring body 8 by cutting. In addition, a thin metal ring 15 is also manufactured separately. The outer ring main body 8 and the thin metal ring body 15 having the circumferential groove 14 described above are sandblasted, degreased, coated with adhesive at necessary locations, and set in a mold.

The mold includes an upper mold 20, a lower mold 2I, a split mold outer mold 22 that can be divided into two in the radial direction, and an outer mold retainer 23 that holds the split mold so that it does not separate. Cage, outer mold 2
A shallow circumferential groove 24 in which a thin metal ring body 15 is mounted is provided on a surface of the inner circumferential surface of the outer ring body 8 facing the outer circumferential surface 9 of the outer ring body 8 .

The outer ring main body 8 is mounted by vertically sandwiching the end portion of the circumferential groove I4 between an upper mold 20 and a lower mold 21.

The thin metal ring 15 is attached to the circumferential groove 24 of the outer mold 22. At this point, the thin metal ring body 15 is formed thick enough to allow attachment to the circumferential groove 24.

Note that the thin metal ring body 15 may not be an endless ring but may be a wound ring with ends.

An outer mold 22 to which the thin metal ring body 15 is attached is placed over the lower mold 21 to which the outer ring main body 8 is attached. As a result, the outer ring body 8
A cavity C is formed that surrounds the outer peripheral surface 9, the end surface 10, and the peripheral groove 14 of the terminal. In the cavity C, the gap is narrower in the portion sandwiched between the outer circumferential surface 9 and the thin metal ring 15 than in other portions.

Next, a mixture of a molding material made of an elastic material such as a synthetic resin and a curing agent is injected into the cavity C through the gate G, and is vulcanized and solidified at a predetermined temperature for a predetermined time (for example, 95° C. x 30 minutes). After solidification, the mold is opened, the molded object having the shape shown in FIG. 5 is taken out, and a post-vulcanization treatment is further performed as necessary.

Thereafter, the unnecessary gate portion g protruding from one end face of the molded object is cut off. Furthermore, the part of the outer peripheral surface of the thin metal ring 15 that protrudes by the amount h to fit into the circumferential groove 24 of the outer mold 22 is removed as an unnecessary part by turning and polishing until it becomes flush, and the shape and shape are adjusted. Adjust the dimensions.

In this way, the outer ring 2 whose outer surface is covered with the non-metallic i-layer 11 is obtained. The bearing 1 is obtained by incorporating the retainer 4 and the rolling elements 5 between the outer ring 2 and the inner ring 3.

Of the coating layer 11 that covers the outer peripheral surface of the bearing l, the surface portion that plays an important function as a fitting surface is protected by the thin metal ring 15 and is not exposed to heat and water.

Material deterioration caused by kerosene, lubricating oil, etc. can be effectively suppressed.

Furthermore, especially on the fitting surface of the outer ring 2, which requires high-precision processing, rubber is difficult to process with high precision.

By having the outer surface of the thin metal ring 15 instead of synthetic resin or the like, dimensional accuracy equivalent to that of a standard steel bearing can be achieved.

Further, the electrical resistance of the coating layer 11 interposed between the thin metal ring body 15 and the outer ring body 8 can be measured for the outer ring 2 alone (for example, in this example, it is 100 MΩ or more).
, This allows the insulation to be easily evaluated.

In addition, the boundary between the thin metal ring 15 and the layer of elastic material such as rubber or synthetic resin is flush, and the integral structure is smooth and continuous from the shoulder of the outer circumferential surface to the bearing end surface, with no unevenness. By doing so, it is possible to prevent the bearing from getting caught and being damaged when it is assembled into or removed from a mating member.

In addition, the outer circumferential surface 9 and end surface l of the outer ring main body 8 are covered with a coating.
By covering the entire O and further wrapping it into the circumferential groove 14 provided on the periphery of the end face, peeling of the coating layer 11 can be completely prevented. Furthermore, since there is no exposed portion of the metal outer ring main body 8 where it faces the housing of the mating member, the possibility of energization can be significantly reduced.

Incidentally, if the coating layer 11 is not formed by wrapping around the circumferential groove 14 of the end surface, it is impossible due to the manufacturing method to completely cover the entire end surface with the coating layer 11, and it can only be formed halfway up the end surface. Some metal n-oxide parts will remain on the end face. With such an exposed end surface, the gap distance between the mating member and the exposed end face when assembled to the mating member is approximately 0°5 mm, so if a high potential difference occurs between the mating member and the outer ring 2, There is a possibility that lightning may strike the other member through the air in the gap or grease containing metal abrasion powder.

Furthermore, by covering the entire end face with the covering layer 11 of an elastic material, there is an advantage that the vibration damping function not only in the radial direction but also in the axial direction can be enhanced.

In the above embodiment, a bearing was described in which the coating layer 11 was used as both an electrical insulation layer and a vibration-proofing layer, considering both the insulation and vibration-proofing functions. In this case, the coating layer 11 can be formed as either an electrically insulating coating layer or a vibration-proofing coating layer by adjusting the thickness, hardness, etc. of the two layers of materials such as rubber and synthetic resin that make up the coating layer 11. You can also.

In the above embodiment, the coating layer 11 and the thin metal ring I5 were formed only on the outer ring 2 side, but they may be provided on the inner ring 3 side.

In that case, the inner diameter surface of the inner ring becomes the fitting surface. Furthermore, it is also possible to provide them on both the outer ring and the inner ring, in which case greater insulation and vibration-proofing functions can be obtained.

Furthermore, the present invention is not limited to ball bearings, but can also be applied to roller bearings.

〔Effect of the invention〕

As explained above, in the rolling bearing of the present invention, the end surface of at least one raceway intersects with the circumferential surface on the raceway surface side.
A circumferential groove is formed by cutting out the J edge, and a coating layer made of an elastic material such as rubber or synthetic resin covers the entire circumferential surface and end surface of the raceway ring on the side opposite to the raceway surface, and the end of the coating layer is placed on the circumferential surface. It was formed by wrapping around inside the groove.

A thin metal ring body is integrally connected to the circumferential surface on the anti-orbital surface side via the coating layer, and the coating layer and the thin metal ring body are smoothly connected without any steps. did. Therefore, important functions of the bearing such as load application and fitting will not be affected, and there is no risk of deteriorating the assembly accuracy of the product, and there will be no damage or peeling when the bearing is installed or removed from a mating member. Moreover, since the coating layer is formed by wrapping around the circumferential groove on the end surface side, the creepage distance between the end surface of the raceway ring and the mating member increases by the distance it wraps around. Even if grease containing metal abrasion powder adheres to the peripheral edge of the circumferential groove side of the ring, it will not be affected by the adhesion, and therefore the rolling mechanism is highly reliable and has the required electrical insulation and vibration damping functions. The effect of being able to provide a bearing can be obtained.

In addition, the method for manufacturing a rolling bearing of the present invention includes arranging a bearing ring having a circumferential groove at the end of the end surface of the bearing ring in a mold, In addition to forming a cavity surrounding the surface, a metal ring body facing the circumferential surface on the opposite raceway side with a gap is shallowly inserted into the mold, and an elastic material such as rubber or synthetic resin is placed in the cavity. The molding material made of metal is sealed and solidified, and after the molded object is removed from the mold, unnecessary protruding parts including the protruding surface of the metal ring are removed. Therefore, the effect that the rolling bearing of the present invention described above can be easily mass-produced is obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the rolling bearing of the present invention;
Fig. 2 is an enlarged view of the main parts of Fig. 1, Fig. 3 is a cross-sectional view showing the state of mold assembly in the manufacturing process of the rolling bearing of the present invention, and Fig. 4 is a cross-sectional view of the mold into which molding material is injected. , FIG. 5 is an enlarged sectional view of the main part of the molded product immediately after being taken out from the mold. In the figure, 1 is a rolling bearing, 2 is an outer ring, 3 is an inner ring, 8 is an outer ring body, 9 is an outer peripheral surface, 10 is an end surface, 11 is a coating layer, 14
1 is a circumferential groove, and 15 is a thin metal ring. Figure 5 2

Claims (4)

[Claims] (1) In a rolling bearing having a non-metallic coating layer on the peripheral surface and end surface of at least one of the inner and outer raceway rings on the side opposite to the raceway surface, the end surface and raceway surface side of the at least one raceway ring are provided. A circumferential groove is formed by cutting out an edge where the circumferential surface of A thin metal ring body is formed to cover and wrap around inside the circumferential groove, and is integrally connected to the circumferential surface on the opposite raceway surface side via the coating layer, and furthermore, the coating layer and the thin metal ring A rolling bearing is characterized by a smooth connection between the ring body and the ring body. (2) Claim (1) wherein the coating layer is an electrically insulating coating layer.
Rolling bearings listed. (3) The rolling bearing according to claim (1), wherein the coating layer is a vibration-proof coating layer. (4) One raceway ring having a circumferential groove formed by cutting out the edge where the end face and the circumferential surface on the raceway side intersect is arranged in the mold, and the circumferential groove of the raceway, the end face, and the opposite raceway are arranged. A metal ring body is formed by shallowly fitting into the mold to form a cavity surrounding the circumferential surface of the surface side, and faces the circumferential surface of the counter-race surface side with a desired gap therebetween. rubber,
A claim characterized in that a molding material made of an elastic material such as a synthetic resin is enclosed and solidified, and after the molded object is removed from the mold, unnecessary protruding parts including the protruding surface of the metal ring are removed. 1) Method of manufacturing the rolling bearing described.