JP2010190282A - Roll bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roll bearing reducing manufacturing costs, reducing the friction resistance on a sliding surface, and inhibiting the increase in the torque of a bearing while maintaining sealing effect against moisture. <P>SOLUTION: A deep groove ball bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rolling elements 4 rollably disposed between both raceway surfaces 2a, 3a, and a seal member 10 attached to a seal groove formed at the outer ring 3 which is a stationary ring and abutting on the sliding surface 2d of the seal groove 2b formed on the inner ring 2 which is a rotation ring. Corrosion resistant coating 30 formed by shot-blasting solid lubricant having rust prevention properties is formed on the sliding surface 2d. The corrosion resistant coating 30 is composed of zinc and tin, and is formed by shot-blasting tin particles after shot-blasting zinc particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing provided with a seal member.

Conventionally, in rolling bearings in which the inner ring and the outer ring are made of stainless steel, when used for a rotating spindle of a washing machine, etc., it is used in an environment where moisture such as water vapor exists. It is required to have a structure that prevents moisture from entering.
As a structure of a rolling bearing for preventing moisture from entering the inside, it is common to install a contact seal made of rubber or the like between the inner ring and the outer ring. Specifically, one end of the contact seal is fixed to the outer ring as the stationary ring, and the other end of the contact seal is brought into contact with the sliding surface of the inner ring as the rotating ring. When the inner ring rotates relative to the outer ring, the sliding surface of the inner ring slides on the other end of the contact seal, and the other end of the contact seal is always in close contact with the sliding surface. The structure which prevents the penetration | invasion of the water | moisture content to the inside (refer patent document 1) is made.

Japanese Patent Laid-Open No. 2007-17795

However, when general steel is used as the material of the rolling bearing, rust may be generated on the sliding surface with which the seal member abuts in the presence of moisture. And since this rust forms an uneven shape on the sliding surface, the adhesion between the sliding surface and the seal member is lowered, and as a result, there is a problem that moisture enters the inside of the rolling bearing. It was.
As a measure for preventing the occurrence of rust, the use of a corrosion-resistant metal as the material of the rolling bearing can be mentioned. However, since it is more expensive than steel, there is a problem that the manufacturing cost increases.

Further, since the other end of the contact seal is always in close contact with the sliding surface, a frictional resistance is generated on the sliding surface, resulting in a problem of increasing the bearing torque.
Therefore, the present invention has been made paying attention to the above-mentioned problems, and its purpose is to reduce the manufacturing cost while reducing the frictional resistance of the sliding surface while maintaining the sealing effect against moisture, An object of the present invention is to provide a rolling bearing capable of suppressing an increase in torque.

In order to solve the above-mentioned problems, the present inventors have conducted intensive studies, and as a result, it is effective to apply an inexpensive rust-proof coating treatment to a general bearing steel material (SUJ2 etc.) on the sliding surface. I found out.
The present invention is based on the above findings by the present inventors, and a rolling bearing according to the invention described in claim 1 for solving the above-described problems is provided between an inner ring, an outer ring, the inner ring, and the outer ring. One end is fixed to an annular seal groove formed on a stationary ring side of either the inner ring or the outer ring and a plurality of rolling elements arranged so as to freely roll, and the outer ring or the inner ring rotates. A rolling bearing provided with a seal member whose other end abuts against a sliding surface of a seal groove formed on a ring side, wherein a corrosion-resistant film containing zinc and tin is formed on the sliding surface. .

The rolling bearing according to the invention described in claim 2 is the rolling bearing according to claim 1, wherein the corrosion-resistant coating is formed by shot blasting zinc particles and then shot blasting tin particles. It is characterized by that.
Moreover, the rolling bearing according to the invention of claim 3 is the rolling bearing according to claim 1 or 2, wherein the zinc content of the corrosion-resistant coating is 5% by mass or more and 80% by mass or less. The content is 95% by mass or less and 20% by mass or more.

A rolling bearing according to the invention of claim 4 is the rolling bearing according to any one of claims 1 to 3, wherein the thickness of the corrosion-resistant coating is 0.1 μm or more and 5 μm or less. It is said.
The rolling bearing according to the invention described in claim 5 is the rolling bearing according to claim 1, wherein the other end portion of the seal member has a plurality of lip portions separated by an annular groove portion. It is a feature.

According to a sixth aspect of the present invention, there is provided the rolling bearing according to the first aspect, wherein one end of the seal member has a flange that covers the seal groove on the stationary wheel side. Yes.
According to a seventh aspect of the present invention, there is provided a rolling bearing according to the first aspect, wherein the bearing structure is an angular ball bearing.

  According to the rolling bearing of the first aspect of the present invention, since the corrosion-resistant coating containing zinc and tin is formed on the sliding surface, the frictional resistance of the sliding surface is reduced while maintaining the sealing effect against moisture. Thus, it is possible to provide a rolling bearing that suppresses an increase in bearing torque. When shot blasting a solid lubricant with anti-rust properties against the sliding surface, the solid lubricant is welded to the sliding surface by physical collision energy (collision heat), forming a corrosion-resistant coating that has both corrosion resistance and lubricity. The As a result, excellent rust preventive properties higher than martensitic stainless steel (SUS440C) are imparted, and lubricity is also imparted. As with shot peening, solid lubricant shot blasting can be performed with general shot blasting equipment and shot peening equipment, and can be processed at once on a large number of sliding surfaces. In addition, processing can be performed at low cost.

  The shot blasting device and the shot peening device are not particularly limited, and devices such as a pneumatic type and a centrifugal force type can be used. Moreover, it is preferable to adjust the atmosphere environment at the time of shot blasting suitably. For example, when forming a corrosion-resistant film on a rolling bearing for vacuum, it is preferable to perform shot blasting under reduced pressure or in vacuum using a centrifugal shot blasting apparatus. Furthermore, when a solid lubricant having a finer particle diameter is shot, it is preferable to perform in an inert gas atmosphere such as nitrogen or argon because oxidation of the solid lubricant is reduced.

  Furthermore, since rust prevention is imparted by the corrosion resistant coating, it is not necessary to apply rust prevention oil to the sliding surface. Furthermore, since the sliding surface has been given rust prevention without applying rust prevention oil, the rolling bearing of the present invention is provided around a member (for example, a member made of a polymer material) that is adversely affected by the rust prevention oil. It is also possible to arrange. As the solid lubricant, it is preferable to use both a base metal and a noble metal together with iron, which is a main component of steel (base material) constituting the inner ring and the outer ring.

  According to the rolling bearing according to claim 2 of the present invention, a corrosion-resistant coating containing zinc, which is a base metal rather than iron, which is the main component of steel constituting the inner ring and outer ring, is formed on the sliding surface. And even in an environment where rust is likely to occur (for example, a high humidity environment), base zinc binds preferentially to oxygen and becomes zinc oxide rather than iron, so iron binds to oxygen. Rust is suppressed. Further, since the corrosion resistant coating contains tin which is a noble metal than iron and is hard to rust, the base material is protected and rusting is suppressed. Furthermore, if a relatively hard zinc oxide powder is formed on the surface of the corrosion-resistant coating formed on the sliding surface, the acoustic performance of the rolling bearing may be adversely affected. However, the corrosion-resistant coating contains tin. Therefore, the formation of zinc oxide powder on the surface of the corrosion resistant coating is suppressed.

  The corrosion-resistant film formed by shot blasting zinc particles and then shot blasting tin particles has the following two-layer structure, alloy structure, composite structure, sea-island structure, or two or more of these structures It seems to have a mixed structure. That is, the two-layer structure is a structure in which the corrosion-resistant film is composed of two layers of an inner zinc layer and a surface-side tin layer. The alloy structure is a structure in which almost the entire corrosion-resistant film is made of an alloy of zinc and tin. Furthermore, the composite structure is a structure in which almost the entire corrosion-resistant film is composed of a mixture of zinc and tin, and the ratio of zinc gradually decreases from the inner side (base material side) to the surface side, and tin. It is a structure where the ratio of increases gradually. Furthermore, the sea-island structure is a structure in which tin is distributed in an island shape in the zinc matrix. An example of a structure in which two or more of these structures are mixed is a three-layer structure including three layers of an inner (base metal side) zinc layer, an intermediate alloy layer, and a surface side tin layer. .

Note that mixed particles of zinc particles (metal particles that are lower than iron) and tin particles (precious or equivalent to iron than iron) or particles of an alloy of zinc and tin may be shot blasted. Alternatively, the zinc particles may be shot blasted after the tin particles are shot blasted.
According to the rolling bearing according to claim 3 of the present invention, the corrosion-resistant coating film having such a configuration has excellent rust prevention and lubricity. In addition, it is more preferable that the zinc content of the corrosion-resistant coating is 10% by mass or more and 50% by mass or less, the tin content is 90% by mass or less and 50% by mass or more, and the zinc content is 20% by mass or more and 40% by mass. % Or less and the tin content is more preferably 80% by mass or less and 60% by mass or more.

According to the rolling bearing according to claim 4 of the present invention, if the thickness of the corrosion-resistant film is more than 5 μm, it becomes difficult to uniformly coat the corrosion-resistant film, and the corrosion-resistant film is likely to fall off. There is a possibility of becoming a foreign object for the rolling bearing. On the other hand, if the thickness of the corrosion-resistant film is less than 0.1 μm, there is a possibility that sufficient and continuous corrosion resistance cannot be obtained.
The thickness of the corrosion-resistant film can be controlled by shot blasting conditions such as the injection pressure (for example, 0.29 to 0.69 MPa) and the injection time (for example, 10 to 20 minutes). Further, the thickness of the corrosion-resistant film can be expressed by converting the unit from μm to g / m ² from the mass difference before and after the formation of the corrosion-resistant film. In the case of a corrosion-resistant coating composed of zinc, 1 μm corresponds to 7.1 g / m ² .

According to the rolling bearing of the present invention, the internal pressure is lowered by the lip portion on the outer side (fixed ring (outer ring) side of the seal member) without installing an air vent hole in the seal member, and the inner side (seal member). Intrusion of water can be prevented by the lip portion of the rotating wheel (inner ring) side.
According to the rolling bearing according to claim 6 of the present invention, the inner ring is a rotating ring, the outer ring is a fixed ring, and used for a main shaft of a washing machine in which water is assumed to accumulate in a seal groove portion of the outer ring. If this happens, it will be difficult for water to enter the seal groove, thus providing further waterproofness.

  According to the rolling bearing according to claim 7 of the present invention, it is possible to increase the number of rolling elements while keeping the width dimensions of the inner and outer diameters of the rolling bearing the same, and the additional capacity of the bearing can be increased. It can be used as the main axis of a large-capacity drum type washing machine. Further, when the rolling element is made of ceramic, if the bearing type is angular, the load per rolling element can be reduced, which has the effect of improving reliability. In particular, in the case of so-called low-cost ceramic rolling elements such as alumina-zirconia, even if the number of rolling elements increases, the cost increase is slight, so that the cost can be reduced.

It is a fragmentary longitudinal cross-section which shows the structure in 1st Embodiment of the rolling bearing which concerns on this invention. It is a fragmentary longitudinal cross-section which shows the structure in 2nd Embodiment of the rolling bearing which concerns on this invention. It is a fragmentary longitudinal cross-section which shows the structure in 3rd Embodiment of the rolling bearing which concerns on this invention. It is a fragmentary longitudinal cross-section which shows the structure in 4th Embodiment of the rolling bearing which concerns on this invention. It is a fragmentary longitudinal cross-section which shows the structure in 5th Embodiment of the rolling bearing which concerns on this invention.

Embodiments of a rolling bearing according to the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a partial longitudinal sectional view showing the structure of a deep groove ball bearing which is a first embodiment of a rolling bearing according to the present invention. The deep groove ball bearing 1 includes an annular inner ring 2 having a raceway surface 2a on the outer circumferential surface, an annular outer ring 3 having a raceway surface 3a opposite to the raceway surface 2a of the inner ring 2 on the inner circumferential surface, and both raceway surfaces. And a plurality of rolling elements 4 disposed between 2a and 3a so as to be freely rollable.

In the outer ring 3, seal grooves 3 b and 3 c are formed on the inner surface and the outer surface of the raceway surface 3 a in the rotation axis direction of the deep groove ball bearing 1 in an annular shape coaxial with the rotation shaft of the deep groove ball bearing 1, respectively. One end 13 of a seal member 10 to be described later is attached to the seal groove 3b. One end 13 of the seal member 20 is attached to the seal groove 3c.
Further, in the inner ring 2, seal grooves 2 b and 2 c are formed on the inner surface and the outer surface of the raceway surface 2 a in the rotation axis direction of the deep groove ball bearing 1 in an annular shape coaxial with the rotation shaft of the deep groove ball bearing 1, respectively. Yes. The seal groove 2b has a sliding surface 2d with which the other end 12 of the seal member 10 to be described later comes into contact. The seal groove 2c has a sliding surface 2e with which the other end 22 of the seal member 20 abuts. As the sliding surfaces 2d and 2e, inner wall surfaces of the seal grooves 2b and 2c are preferable. In addition, a cage 5 that holds each rolling element 4 is provided between the inner ring 2 and the outer ring 3.

The shaft member 60 is fitted on the inner circumferential surface of the inner ring 2, and the outer circumferential surface of the outer ring 3 is fitted on the bearing support portion 70 of the rotary drum. Thus, the rotating drum is rotatably supported by the deep groove ball bearing 1.
A corrosion-resistant coating 30 is formed on the sliding surfaces 2d and 2e. The corrosion resistant coating 30 is formed by shot blasting a solid lubricant having rust prevention properties on the sliding surfaces 2d and 2e.

  Although the kind of solid lubricant which comprises this corrosion-resistant film 30 will not be specifically limited if it has rust prevention property, For example, it is preferable that zinc and tin are included. The corrosion resistant coating 30 containing zinc and tin is preferably formed by shot blasting the zinc particles and then shot blasting the tin particles. However, it may be formed by shot blasting the zinc particles and then shot blasting the zinc particles, or may be formed by shot blasting a mixture of zinc particles and tin particles.

  The thickness of the corrosion resistant coating 30 is preferably 0.1 μm or more and 5 μm or less. If the thickness is 0.1 or more, for example, the corrosion resistant coating 30 is less likely to fall off due to the rotation of the inner ring 2 with respect to the outer ring 3, and the frictional resistance of the sliding surfaces 2d and 2e is maintained while maintaining the sealing effect. And an increase in torque of the rolling bearing 1 can be suppressed. On the other hand, if the thickness of the corrosion-resistant coating 30 is less than 0.1 μm, there is a possibility that sufficient and continuous corrosion resistance on the sliding surfaces 2d and 2e cannot be obtained. Further, if the thickness of the corrosion-resistant coating 30 is more than 5 μm, the elastic force of the seal members 10 and 20 in contact with the corrosion-resistant coating 30 is lowered by the thickness, and it may be difficult to maintain a sufficient sealing function. There is. And it is still more preferable that the corrosion resistant coating 30 is burnished.

  The sealing member 10 is formed by covering an annular core material 11 with an elastic material such as rubber or synthetic resin and extending in the radial direction of the core material 11. One end 13 of the seal member 10 is attached to a seal groove 3 b formed in the outer ring 3. The other end portion 12 of the seal member 10 is in contact with a sliding surface 2 d constituting a seal groove 2 b formed in the inner ring 2 by the elastic force of the core member 11.

  Similarly to the seal member 10, the seal member 20 is formed by covering an annular core material 21 with an elastic material such as rubber or synthetic resin and extending in the radial direction of the core material 21. One end 23 of the seal member 20 is attached to a seal groove 3 c formed in the outer ring 3. The other end 22 of the seal member 20 is in contact with the sliding surface 2 e that forms the seal groove 2 c formed in the inner ring 2 by the elastic force of the core member 11.

As a material of the elastic material used for the seal members 10 and 20, conductive rubber is preferable. By adopting conductive rubber as the material of the covering material of the seal members 10 and 20, the seal members 10 and 20 and the inner ring 2 and the outer ring 3 are in contact at a plurality of locations. Can be high.
Japanese Patent Application Laid-Open No. 2002-139052 discloses a processing method in which a solid lubricant is shot-peened on the sliding surfaces 2d and 2e in order to form the corrosion-resistant coating 30. This treatment method is a method in which the corrosion resistant coating 30 is welded to the surface of the mother village (sliding surfaces 2d and 2e) by physical collision energy (collision heat) by shot peening a solid lubricant.

  Evaluation of the rust prevention performance in the rolling bearing of this embodiment can be evaluated by a change in weight. As an evaluation method for corrosion resistance, the area where rust is generated may be measured visually, but the evaluation method described in JP-A-8-327342 is preferably used. This evaluation method uses the fact that the metal rust generation surface has less specular reflection light and more irregular reflection light than the normal surface, recognizes the rust generation surface by the ratio of both reflection intensities, and automatically rust generation area It is a method to ask for. In this evaluation method, it is said that speeding up of measurement and labor saving are achieved. However, in the present invention, the degree of rust generation is not an area but defined as “rust generation amount = weight increase amount of metal to be evaluated”. By doing so, it became possible to quantify rust with more specific values than in the prior art. Further, the metal to be evaluated does not need to be a predetermined test piece, and rust can be evaluated regardless of the shape. Furthermore, since it can be determined only by weight measurement, no special device or preparation is required.

  The corrosion-resistant coating 30 may be formed on the inner surface of the inner ring 2 and the outer surface of the outer ring 3, the cage 5, the seal members 10 and 20, or other attached members other than the sliding surfaces 2d and 2e. . The method for forming the corrosion-resistant coating 30 is the same as the above-described method for forming the corrosion-resistant coating 30 on the sliding surfaces 2d and 2e. In particular, when these cages 5 or other attached members are made of steel, the same rust prevention effect as described above can be expected. By forming a corrosion-resistant film on the surface of the cage 5, at least a sliding portion with the rolling element can be expected to have an effect of lubrication and rust prevention. In addition, by forming a corrosion-resistant film on the surface of other attached members, there is a contact with the external environment, and therefore a rust-preventing effect can be expected under circumstances where it comes into contact with moisture. The same applies to spacers and separators. Furthermore, in normal rolling bearings, anti-rust oil may be applied to prevent the outer surface of the bearing from being rusted.However, when the anti-rust oil applied to the outer surface of the bearing is exposed to high temperatures, an unpleasant odor is generated as described above. It is also possible that it will generate or vaporize and evaporate and adversely affect the surrounding environment of the bearing. In particular, when there is a resin part near the bearing, the possibility increases. If it is a rolling bearing which concerns on this invention, since it is also possible to omit application | coating of the antirust oil of a bearing outer surface, the above problems are hard to arise.

  In the present embodiment, a water-repellent film may be formed on the surfaces of the seal members 10 and 20 and the surfaces of the members positioned around the seal members 10 and 20. In addition, a water-repellent film may be formed on the corrosion-resistant film 30. For the formation of this water-repellent coating, it is preferable to use the technique disclosed in paragraphs [0025] to [0029] of JP-A-2002-339995.

In recent years, since the number of inverter type washing machines has been increasing, the material of the rolling element 4 may be ceramic for the purpose of reducing the occurrence of electrolytic corrosion caused by the induced current generated from the inverter motor.
Furthermore, a resin coating or a ceramic spray layer may be formed on the inner wall surface of the inner ring 2 or the outer wall surface of the outer ring 3. The formation of the resin coating makes it difficult to transmit not only insulation but also vibration generated by the rolling bearing 1 to the housing, and is effective in reducing vibration and noise.

(Second Embodiment)
FIG. 2 is a partial longitudinal sectional view showing the structure of a deep groove ball bearing which is a second embodiment of the rolling bearing according to the present invention. In the description of the present embodiment, the description of the same configuration as that of the first embodiment described above is omitted.

As shown in FIG. 2, in the rolling bearing 1 of the present embodiment, a plurality of lip portions 12 a and 12 b are formed at the other end portion 12 of the seal member 10. The outer lip portion 12b has grooves formed at several locations on the upper surface. A region S ₁ is formed by the seal groove 2b and the plurality of lip portions 12a and 12b. Hereinafter, since the seal member 20 has the same configuration, the description thereof is omitted.

Further, the seal member 10 is formed with a collar portion 14 that is branched separately from the one end portion 13 and is formed so as to cover a part of the side surface portion of the outer ring 3 in an annular shape. A region S ₂ is formed by the seal groove 3 b, the one end portion 13, and the flange portion 14. The flange portion 14 is formed so as to sandwich the outer edge portion 3d formed by forming the seal groove 3b together with the one end portion 13.
A conventional seal member used as a sealant for a rolling bearing is used to reduce the occurrence of a pressure difference with the outside due to an increase in temperature inside the rolling bearing during operation (rotation) of the rolling bearing. A through hole penetrating the seal member may be provided. However, this through hole may cause moisture or dust to enter the inside of the rolling bearing. Also, the conventional rolling bearing used for the washing machine support spindle is made of SUJ2 steel with a non-contact metal shield plate, and an oil seal is installed between this bearing and the washing tub. Thus, it is designed so that moisture is not applied to the bearing portion. Therefore, in the rolling bearing 1 of the present embodiment, the lip on the outer side (the fixed ring (inner ring 3) side of the seal member 10) among the plurality of lip portions 12a and 12b formed on the other end portion 12 of the seal member 10. The grooves formed in several places on the upper surface of the portion 12b have an effect of reducing the internal pressure through the groove when the other end portion 12 comes into contact with the sliding surface. Further, the lip portion 12 a on the inner side (the rotating wheel (inner ring 2) side of the seal member 10) abuts against the corrosion-resistant coating 30 formed on the sliding surface 2 d, and moisture enters the inside of the rolling bearing 1. There is an effect to prevent.

  In addition, since the other end portion 12 that contacts the sliding surface 2d has a plurality of lip portions 12a and 12b, it is not necessary to install an oil seal between the bearing and the washing tub. The effect is to reduce the cost. Moreover, since the torque required to rotate the main shaft of the washing machine can be reduced by using the rolling bearing of the present embodiment, there is an effect of promoting energy saving as a product.

Further, the rolling bearing 1 of the present embodiment is configured such that when the inner ring 2 is used as a rotating wheel and the outer ring 3 is used as a fixed ring as a main shaft of a washing machine, the seal grooves 3b, It becomes difficult for water to enter 3c, and further waterproofness is demonstrated.
The seal member 10 may be formed with at least one of the plurality of lip portions 12a and 12b and the flange portion 14.

The region S ₁ formed by the annular groove 12c formed by the lip portions 12a and 12b and the corrosion-resistant coating 30, and the one end 13 of the seal member 10, the flange 14 and the seal groove 3b are formed. of in at least one region S _2, it is preferable that the high-viscosity fluid is sealed (see FIG. 2).
The high-viscosity fluid enclosed in at least one of the region S ₁ and the region S ₂ is preferably a high-viscosity grease. Furthermore, highly conductive grease, highly conductive oil, ionic liquid, etc. It is more preferable that the grease has at least one of water resistance, heat resistance and low torque. Specific examples include greases containing diurea as a thickener, poly-α-olefin as a base oil, and carbon black added. The blending degree of grease is preferably 200 to 300. Moreover, as a viscosity of a base oil, 30-500 mm < ² > / s (40 degreeC) is preferable.

The amount of fluid sealed in at least one of the region S ₁ and the region S ₂ is preferably 10 to 70% by volume of each volume of the regions S ₁ and S ₂ .
If the amount of fluid sealed in at least one of the region S ₁ and the region S ₂ exceeds 70% by volume of each volume of the regions S ₁ and S ₂ , the torque may increase, There is a risk of increased leakage. On the other hand, if it is less than 10% by volume, the lubricity becomes low when used in an atmospheric environment, and the durability of the rolling bearing may be insufficient. In a vacuum environment or an environment where oils and fats are disliked, it is preferable that the amount of fluid enclosed is small.

  By using such a fluid, not only the conductivity between the inner ring 2 and the outer ring 3 is ensured, but also the effect of preventing moisture from entering the rolling bearing 1 and the inner ring 2 with respect to the outer ring 3 are improved. An effect such as a reduction in torque when rotating is obtained.

(Third embodiment)
In the above embodiment, a deep groove ball bearing has been described as an example of a rolling bearing. However, the type of the rolling bearing is not limited to the deep groove ball bearing, and the present invention is applied to various types of rolling bearings. can do. For example, radial type rolling bearings such as angular contact ball bearings, self-aligning ball bearings, self-aligning roller bearings, needle roller bearings, cylindrical roller bearings, tapered roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing. Among these, it is preferable to apply to an angular ball bearing.

  FIG. 3 is a partial vertical cross-sectional view showing the configuration of the rolling bearing according to the third embodiment of the present invention. In the description of the present embodiment, the description of the same configuration as that of the first embodiment is omitted. As shown in FIG. 3, the rolling bearing in the present embodiment has a predetermined contact direction between the spherical surface portion of the rolling element 4 and the contact surfaces of the inner ring and the outer ring with respect to an orthogonal plane orthogonal to the rotation center axis. It is an angular type bearing having a contact angle.

Like this embodiment, by making the structure of the rolling bearing an angular type, it is possible to increase the number of rolling elements even if the width dimension of the inner and outer diameters of the rolling bearing is the same. Since the capacity can be increased, it is suitable for large-capacity drums.
Further, when the rolling element is made of ceramic, if the structure of the rolling bearing is angular, the load per rolling element can be reduced, so that the driving reliability of the rolling bearing is improved. In particular, in the case of so-called low-cost ceramic rolling elements such as alumina-zirconia, even if the number of rolling elements increases, the cost increase is slight, so the angular system is an effective means.

(Fourth embodiment)
FIG. 4 is a partial longitudinal sectional view showing the configuration of the rolling bearing according to the fourth embodiment of the present invention. In the description of the present embodiment, the description of the same configuration as that of the first embodiment is omitted. As shown in FIG. 4, the groove part 3e may be formed in the outer peripheral surface of the outer ring | wheel 3 of the rolling bearing 1, and the O-ring 40 may be attached to this groove part 3e. Although not shown, an O-ring may be attached to a groove formed on the inner peripheral surface of the inner ring 3. By attaching an O-ring to at least one of the outer peripheral surface of the outer ring 3 and the inner peripheral surface of the inner ring 2 of the rolling bearing 1, not only creep prevention but also the rolling bearing 1, the shaft member 60 of the rotating drum, and the bearing support are provided. When there is a gap with the portion 70, it is possible to stop moisture that is about to go out through the gap. In addition, you may give the said corrosion-resistant film 30 to the groove part 3e to which the O-ring 40 is attached.

(Fifth embodiment)
FIG. 5 is a partial longitudinal sectional view showing the configuration of the rolling bearing according to the fifth embodiment of the present invention. In the description of the present embodiment, the description of the same configuration as that of the first embodiment is omitted. As shown in FIG. 4, the thick portion 50 may be formed on the outer wall surface of the outer ring 3 that is a stationary ring, and the flange portion 15 may be formed so that the contact area on the side surface of the outer ring 3 is enlarged. . Further, the groove 3f in which the flange 25 is embedded may be formed on the side surface of the outer ring 3, and the side surface of the outer ring 3 and the surface of the flange 25 may be installed substantially flush with each other.

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner ring | wheel 2a Raceway surface 2b Seal groove 2c Seal groove 2d Sliding surface 3 Outer ring 3a Raceway surface 3b Seal groove 3c Seal groove 4 Rolling element 10 Seal member 12 The other end part 12a 1st lip part 12b 2nd Lip part 13 One end part 14 Gutter part 30 Corrosion resistant coating

Claims (7)

  One of an inner ring, an outer ring, a plurality of rolling elements arranged to roll between the inner ring and the outer ring, and an annular seal groove formed on the stationary ring side of either the inner ring or the outer ring. An anti-corrosion coating film comprising zinc and tin in a rolling bearing having an end portion fixed and a seal member having the other end abutting against a sliding surface of a seal groove formed on the rotating ring side of either the outer ring or the inner ring Is formed on the sliding surface.   The rolling bearing according to claim 1, wherein the corrosion-resistant film is formed by shot blasting zinc particles and then shot blasting tin particles.   The zinc content of the corrosion-resistant film is 5% by mass or more and 80% by mass or less, and the content of tin is 95% by mass or less and 20% by mass or more. Rolling bearings.   The rolling bearing according to any one of claims 1 to 3, wherein the corrosion-resistant film has a thickness of 0.1 µm or more and 5 µm or less.   The rolling bearing according to claim 1, wherein the other end portion of the seal member has a plurality of lip portions separated by an annular groove portion.   The rolling bearing according to claim 1, wherein one end portion of the seal member has a flange portion that covers the seal groove on the stationary wheel side.   The rolling bearing according to claim 1, wherein the structure of the bearing is an angular ball bearing.

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