JP2008281074A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing having resistance to grease leakage, a long serving life achieved by suppressing peeling due to hydrogen brittleness, and a space saving property at the same time and at low cost. <P>SOLUTION: A blending rate of aluminum additive blended to a base grease is equal to or greater than 0.05 wt.% and equal to or less than 10 wt.% per base grease 100 wt.%. About an inner surface of each pocket in a retainer 4, a part closer to an inner diameter side than a ball array pitch circle is formed as a recessed curved surface of which diameter becomes smaller as becoming closer to an opening edge of an inner diameter side of the retainer and a recessed part extending from the opening edge of an inner diameter side of the retainer to an outer diameter side of the retainer is provided in the inner surface of each pocket. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing, for example, to a technique for solving grease leakage and peeling due to hydrogen embrittlement in a rolling bearing used in an automobile auxiliary machine such as an idler pulley and an alternator.

Bearings used for automobile auxiliary machines such as idler pulleys and alternators are required to have many properties such as grease leakage resistance, long life, low torque, mud water resistance, high temperature resistance and low temperature resistance. Among these requirements, various techniques as described below have been proposed in order to improve grease leakage resistance.
(1) Protrusions are formed at a plurality of locations in the circumferential direction on the inner diameter side outer surface of the seal ring locked to the outer ring toward the inner surface of the seal groove of the inner ring (for example, Patent Document 1).
(2) An annular slinger is fixed to the inner ring. The slinger is disposed between the seal and the rolling element, and its inner peripheral edge is fixed to the outer diameter surface of the inner ring (for example, Patent Document 2).
(3) The seal lip shape is changed and a labyrinth clearance is formed (for example, Patent Document 3).
(4) A passivating oxidizing agent is added to the enclosed grease (for example, Patent Document 4).
(5) For example, bismuth dithiocarbamate is added to a urea grease made of a lubricating base oil made of a poly-α-olefin synthetic oil and a diurea thickener (for example, Patent Document 5).
JP 2006-250272 A JP 2003-314573 A JP 2005-330986 A JP-A-3-210394 JP-A-2005-42102

  The ones disclosed in Patent Documents 1 to 3 require a space for providing a protruding portion and a slinger in the axial direction of the bearing, which increases the number of parts and increases the manufacturing cost. Also, in terms of life, unlike normal peeling due to normal metal fatigue, there is peeling due to hydrogen embrittlement caused by hydrogen, resulting in a short life. On the other hand, countermeasures according to the above-mentioned Patent Documents 4 and 5 are taken, but in the above-mentioned applications in which usage conditions become severe year by year, the countermeasures according to these Patent Documents 4 and 5 are insufficient.

  An object of the present invention is to provide a rolling bearing that can achieve grease leakage resistance, long life with suppressed peeling due to hydrogen embrittlement, and space saving at the same time and at low cost.

  In the first rolling bearing according to the present invention, a plurality of balls interposed between inner and outer rings are held in a cage, and a grease composition is sealed in a bearing space between the inner ring and the outer ring, and is provided in the outer ring or the inner ring. In a rolling bearing that seals the bearing space with a seal member, the grease composition is formed by adding an additive to a base grease composed of a base oil and a thickener, and the additive is made of aluminum powder and an aluminum compound. Containing at least one selected aluminum-based additive, and the blending ratio of the aluminum-based additive is 0.05 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease. Pockets that hold the balls of the ball at multiple locations in the circumferential direction, and the inner surface of each pocket is the inner diameter side of the ball arrangement pitch circle, the cage A ring-shaped retainer having a concave curved surface shape having a smaller diameter as it approaches the diameter-side opening edge, and a concave portion extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage is provided on the inner surface of each pocket. It is characterized by that.

  According to this configuration, the grease composition is formed by adding an additive to a base grease composed of a base oil and a thickener, the additive containing an aluminum-based additive, and the combination of the aluminum-based additive. When the ratio is 0.05 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease, it is possible to prevent specific peeling accompanied by a change in white structure that occurs on the rolling surface. Therefore, occurrence of peeling due to hydrogen embrittlement can be suppressed, and the life of the bearing can be extended.

Furthermore, the inner surface of each cage pocket is provided with a recess extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, making it difficult for grease to adhere to the seal groove of the inner ring and preventing grease leakage. . Therefore, it is not necessary to change the design of the shape of the seal groove, and it is not necessary to secure a space for providing, for example, a slinger in the axial direction of the bearing. Therefore, the number of parts can be made smaller than that described in the above patent document, and the manufacturing cost can be reduced.
By applying the cage and the grease composition, the bearing can be operated without hydrogen embrittlement, and there is no grease leakage, so that the lubrication life characteristics of the enclosed grease are sufficiently exhibited. Furthermore, external contamination problems such as abnormal noise due to erosion and slipping on the engine accessory belt due to grease leakage are also eliminated.

  In the second rolling bearing according to the present invention, a plurality of balls interposed between the inner and outer rings are held by a cage, and a grease composition is sealed in a bearing space between the inner ring and the outer ring, and provided in the outer ring or the inner ring. In a rolling bearing that seals the bearing space with a seal member, the grease composition is formed by adding an additive to a base grease composed of a base oil and a thickener, and the additive is made of aluminum powder and an aluminum compound. Containing at least one selected aluminum-based additive, and the blending ratio of the aluminum-based additive is 0.05 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease. Pockets for holding the balls respectively at a plurality of locations in the circumferential direction, the radius from the cage center of the inner diameter of the circumferential portion with the pockets, Characterized by being larger than the radius of the cage center of the inner diameter of the circumferential part between the socket.

According to this configuration, the white structure change occurring on the rolling surface is caused by the mixing ratio of the aluminum-based additive to be mixed with the base grease being 0.05 to 10 parts by weight with respect to 100 parts by weight of the base grease. It is possible to prevent specific peeling accompanied with the above. Therefore, occurrence of peeling due to hydrogen embrittlement can be suppressed, and the life of the bearing can be extended.
Furthermore, since the radius from the cage center of the inner diameter of the circumferential portion with the pocket of the cage is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets, the inner ring shoulder and inner ring Grease hardly adheres to the seal groove. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase. Other operations and effects similar to those of the first rolling bearing are provided.

  In the present invention, the aluminum compound may be at least one compound selected from aluminum carbonate and aluminum nitrate. In the present invention, the thickener may be a urea-based thickener. In the present invention, the base oil may be at least one oil selected from alkyl diphenyl ether oil and poly-α-olefin oil.

  In the first rolling bearing according to the present invention, the grease composition comprises a base grease composed of a base oil and a thickener, and the additive contains an aluminum-based additive. The mixing ratio of the system additive is 0.05 part by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease, and further, on the inner surface of each pocket of the cage, from the opening edge on the cage inner diameter side outside the cage. By providing the dent extending on the diameter side, it is possible to achieve grease leakage resistance, long life with suppressed peeling due to hydrogen embrittlement, and space saving at the same time and at low cost.

  In the second rolling bearing according to the present invention, the grease composition is formed by adding an additive to a base grease comprising a base oil and a thickener, and the additive is selected from aluminum powder and an aluminum compound. It contains at least one aluminum-based additive, and the blending ratio of this aluminum-based additive is 0.05 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease, and a circle having a cage pocket. Suppressing the occurrence of peeling due to grease leakage resistance and hydrogen embrittlement by making the radius of the inner diameter of the circumferential part from the cage center larger than the radius of the inner diameter of the circumferential part between pockets from the cage center Longer life and space saving can be achieved at the same time and at low cost.

An embodiment of the present invention will be described with reference to FIG. The rolling bearing according to this embodiment is used for automobile auxiliary machines such as idler pulleys and alternators, for example. However, the present invention is not necessarily limited to use for automobile auxiliary machines.
In this bearing, a plurality of rolling elements 3 are interposed between the raceways 1a and 2a of the inner ring 1 and the outer ring 2, and a cage 4 to be described later for holding the rolling elements 3 is provided to seal the bearing space on both sides. A non-contact type seal member 5 is provided. The rolling element 3 is made of, for example, a ball. In this case, the bearing is a deep groove ball bearing with a seal. The grease composition Gs of the present invention is enclosed at least around the rolling element 3.

  The seal member 5 is composed of an annular cored bar 6 and a rubber-like member 7 that is integrally fixed to the cored bar 6, and the outer peripheral part is fitted in a seal mounting groove 8 formed on the inner peripheral surface of the outer ring 2. Fixed to state. The rubber-like member 7 is made of synthetic rubber, and the cored bar 6 is made of a steel plate. The inner ring 1 has a seal groove 9 formed of a circumferential groove at a position corresponding to the inner diameter portion of each seal member 5, and a labyrinth seal gap 10 between the inner diameter side end of the seal member 5 and the seal groove 9 of the inner ring 1. Is formed. The seal mounting groove 8 and the seal groove 9 are turned.

The grease composition Gs will be described.
In addition, as a result of intensive studies on a method for effectively preventing peeling at the rolling surface due to hydrogen embrittlement for rolling bearings, a grease composition containing at least one aluminum-based additive selected from aluminum powder and aluminum compound When a rapid acceleration / deceleration test was conducted using a rolling bearing encapsulating, it was found that the bearing life could be extended.
By adding an aluminum-based additive to the grease composition, the aluminum compound reacts on the frictional wear surface or the new metal surface exposed by wear, and an aluminum coating is formed on the bearing rolling surface along with iron oxide. As a result of surface analysis of the surface.
This iron oxide and aluminum coating formed on the rolling surface of the bearing suppresses the generation of hydrogen due to the decomposition of the grease composition and prevents unique peeling due to hydrogen embrittlement. It is done. The present invention is based on these findings.

The aluminum-based additive added to the grease composition according to the embodiment of the present invention is at least one selected from aluminum powder and an aluminum compound. Aluminum compounds include aluminum carbonate, aluminum sulfide, aluminum chloride, aluminum nitrate and its hydrate, aluminum sulfate, aluminum fluoride, aluminum bromide, aluminum iodide, aluminum oxide and its hydrate, aluminum hydroxide, selenium Aluminum fluoride, aluminum telluride, aluminum phosphate, aluminum phosphide, lithium aluminate, magnesium aluminate, aluminum selenate, aluminum titanate, aluminum zirconate and other inorganic aluminum, aluminum benzoate, aluminum citrate and other organic aluminum Is mentioned. These aluminum-based additives may be added to the grease by mixing one type or two types.
Particularly preferable in the present invention is an aluminum powder having a high extreme pressure effect because it is excellent in heat resistance and hardly decomposes thermally.

The mixing ratio of the aluminum-based additive is 0.05 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the base grease. That is, (1) when the aluminum additive is only aluminum powder, 0.05 part by weight or more and 10 parts by weight or less of aluminum powder with respect to 100 parts by weight of the base grease, and (2) the aluminum additive is only an aluminum compound. In this case, 0.05 parts by weight or more and 10 parts by weight or less of the aluminum compound with respect to 100 parts by weight of the base grease. (3) When the aluminum-based additive is an aluminum powder and an aluminum compound, On the other hand, the aluminum powder and the aluminum compound are combined in an amount of 0.05 to 10 parts by weight.
If the blending ratio of the aluminum-based additive is less than this blending range, peeling on the rolling surface due to hydrogen embrittlement cannot be effectively prevented. Moreover, even if the blending ratio of the aluminum-based additive exceeds the above blending range, the peeling prevention effect is not further improved.

The base grease comprises a base oil and a thickener. Base oils that can be used in the present invention include mineral oils such as spindle oil, refrigerator oil, turbine oil, machine oil, dynamo oil, highly refined mineral oil, liquid paraffin, polybutene, GTL oil synthesized by the Fischer-Tropsch method, -Hydrocarbon synthetic oil such as α-olefin oil, alkylnaphthalene, alicyclic compound, etc., or natural oil, polyol ester oil, phosphate ester oil, polymer ester oil, aromatic ester oil, carbonate ester oil, diester oil Non-hydrocarbon synthetic oils such as polyglycol oil, silicone oil, polyphenyl ether oil, alkyldiphenyl ether oil, alkylbenzene oil, and fluorinated oil can be used.
Among these, it is preferable to use alkyl diphenyl ether oil or poly-α-olefin oil excellent in heat resistance and lubricity.

Among the above base greases, the thickeners usable in the present invention include benton, silica gel, fluorine compound, lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap, aluminum complex soap and other soaps, diurea Examples include urea compounds such as compounds and polyurea compounds.
Of these, urea compounds are desirable in view of heat resistance, cost, and the like.

The urea-based compound can be obtained by reacting an isocyanate compound and an amine compound. In order not to leave a reactive free radical, the isocyanate group of the isocyanate compound and the amino group of the amine compound are preferably blended so as to be approximately equivalent.
The diurea compound can be obtained, for example, by reaction of diisocyanate and monoamine. Examples of the diisocyanate include phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, etc. Aniline, p-toluidine, cyclohexylamine and the like can be mentioned.

  The polyurea compound can be obtained, for example, by reacting diisocyanate with a monoamine or diamine. Among these, diisocyanate and monoamine include those similar to those used for the production of diurea compounds, and diamines include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, Examples include xylenediamine and diaminodiphenylmethane.

By adding a thickener such as a urea compound to the base oil, a base grease for blending the aluminum additive and the like can be obtained. A base grease using a urea compound as a thickener is prepared by reacting an isocyanate compound and an amine compound in a base oil.
The blending ratio of the thickener in 100 parts by weight of the base grease is 1 to 40 parts by weight, preferably 3 to 30 parts by weight. If the content of the thickener is less than 1 part by weight, the thickening effect is reduced. If the content of the thickener exceeds 40 parts by weight, the obtained base grease becomes too hard and the desired effect is obtained. It becomes difficult.

  In addition to the aluminum-based additive, a known grease additive may be included as necessary. Examples of the additives include antioxidants such as organic zinc compounds, amines, and phenolic compounds, metal deactivators such as benzotriazole, viscosity index improvers such as polymethacrylate and polystyrene, molybdenum disulfide, and graphite. Solid lubricant, metal sulfonate, rust preventive agent such as polyhydric alcohol ester, friction reducing agent such as organic molybdenum, oily agent such as ester and alcohol, antifriction agent such as phosphorus compound, and the like. These can be added alone or in combination of two or more.

[Example]
Examples 1 to 8
In half of the base oil shown in Table 1, 4,4-diphenylmethane diisocyanate (trade name Millionate MT manufactured by Nippon Polyurethane Industry Co., Ltd., hereinafter referred to as MDI) is dissolved in the ratio shown in Table 1, and the remaining half of the base oil is dissolved. Monoamine, which is twice the equivalent of MDI, was dissolved in the oil. The respective blending ratios and types are as shown in Table 1.
A solution in which monoamine was dissolved was added while stirring the solution in which MDI was dissolved, and then the reaction was continued for 30 minutes at 100 ° C. or higher and 120 ° C. or lower to produce a diurea compound in the base oil.
To this, an aluminum-based additive and an antioxidant were added at a blending ratio shown in Table 1, and the mixture was further stirred at 100 ° C. or higher and 120 ° C. or lower for 10 minutes. Thereafter, the mixture was cooled and homogenized with three rolls to obtain a grease composition.

In Table 1, the synthetic hydrocarbon oil used as the base oil is Shinflud 601 manufactured by Nippon Steel Chemical Co., Ltd. having a kinematic viscosity of 30 mm ² / sec at 40 ° C., and the alkyldiphenyl ether oil is a kinematic viscosity of 97 mm ² / sec at 40 ° C. Moresco High Lube LB100 manufactured by Matsumura Oil Research Co., Ltd. was used. Moreover, the hindered phenol by Sumitomo Chemical Co., Ltd. was used for antioxidant.
The obtained grease composition was subjected to a rapid acceleration / deceleration test. Test methods and test conditions are shown below. The results are shown in Table 1.

<Rapid acceleration / deceleration test>
An alternator, which is an example of an electrical accessory, was simulated, and the grease composition was sealed in a rolling bearing for rotating an inner ring that supports a rotating shaft, and a rapid acceleration / deceleration test was performed. In this rapid acceleration / deceleration test, the operating conditions were set with a load applied to the pulley attached to the tip of the rotating shaft of 1960 N, a rotational speed of 0 rpm to 18000 rpm, and a current of 0.1 A flowing through the test bearing. Carried out. Then, abnormal peeling occurred in the bearing, and the time when the vibration of the vibration detector exceeded the set value and the generator stopped (peeling life time, h) was measured. The test was terminated after 500 hours.

Comparative Examples 1 to 3
In accordance with the method according to Example 1, the base grease was prepared by selecting the thickener and the base oil at the blending ratio shown in Table 1, and the additive was further blended to obtain a grease composition. The obtained grease composition was evaluated by conducting the same test as in Example 1. The results are shown in Table 1.

  As shown in Table 1, in each Example, the rapid acceleration / deceleration test showed excellent results in which the peeling occurrence lifetime was all 400 hours or more. This is considered to be because the specific exfoliation accompanied by the white texture change occurring on the rolling surface could be effectively prevented by adding the aluminum-based additive at a predetermined ratio.

In the rolling bearing according to this embodiment, by using the cage 4 shown below, it is difficult for grease to adhere to the seal groove 9 of the inner ring 1, and grease leakage can be prevented.
The cage 4 will be described with reference to FIGS.
As shown in the perspective view of FIG. 2, the cage 4 is a ring-shaped one having pockets 50 for holding the balls at a plurality of locations in the circumferential direction, and the inner surfaces of the pockets 50 are concave spherical. is there. The retainer 4 is formed by joining two annular retainer halves 51 shown in a perspective view in FIG. 3 so that they face each other in the axial direction and are joined together by a rivet 53 inserted through a rivet hole 52. Composed. These cage halves 51 have a plurality of spherical shell-shaped plate portions 50A whose inner surfaces form half of the pockets 50, and a flat plate portion 51a serving as a portion between adjacent pockets 50; The spherical shell plate portions 50A are alternately arranged in the circumferential direction. The spherical shell-shaped plate portion 50A is a part that becomes a part of the spherical shell, in other words, a counter-sink-shaped bulged portion in which both the inner and outer surfaces are spherical. The projected shape in the axial direction of the cage half 51 is a ring shape having a constant radial width over the entire circumference.

  A part of the cage half 51 is enlarged and shown in a perspective view in FIG. FIG. 4 is a diagram in the case where the pocket inner surface is a monotonous spherical surface in a portion corresponding to FIG. In FIG. 4, a portion A indicated by a two-dot chain line indicates a circumferential band in which the flat plate portions 51a of the cage half 51 are arranged in the circumferential direction. The spherical shell plate portion 50A, which is a half of the pocket 50, is formed at a portion of the circumferential band A that is not the flat plate portion 51a. One side portion of the spherical shell plate portion 50 </ b> A in the drawing is an inner diameter side portion 50 </ b> Ai of the cage 4, and the other side portion of the spherical shell plate portion 50 </ b> A is an outer diameter side portion 50 </ b> Ao of the cage 4.

  As shown in FIG. 5, the inner surface of the pocket 50 (spherical shell plate portion 50 </ b> A) of the retainer 4 of this embodiment is formed on the inner diameter side portion 50 </ b> Ai of the retainer 4 from the opening edge on the inner diameter side of the retainer. A recess 54 extending toward the outer diameter side is provided, and a cross-sectional shape of the inner surface of the recess 54 along the circumferential direction of the cage (that is, a cross-sectional shape taken along a plane perpendicular to the cage central axis) is defined as the inner surface of the pocket 50. An arc shape having a radius of curvature Rb smaller than the radius of curvature Ra of the concave spherical surface.

  The recessed portion 54 is provided at one location so as to spread from the center OW50 in the cage circumferential direction at the opening edge of the pocket 50 to one side, and the width W54 of the recessed portion 54 is the width W50 in the cage circumferential direction of the pocket 50. The width is almost the whole. The width W54 of the recessed portion 54 is preferably larger than half of the width W50 of the pocket 50, and more preferably 2/3 or more, or 3/4 or more.

  The inner surface shape of the recessed portion 54 is a cylindrical surface shape substantially along the surface of the virtual cylinder V centered on the straight line L in the radial direction of the cage 4 as shown in FIG. The virtual cylinder V may be the surface of a grindstone that processes the recess 54. The concave portion 54 extends from the opening edge on the inner diameter side of the cage to the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases, that is, gradually, from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape is shallow and narrow. In this embodiment, the dent 54 extends to the ball arrangement pitch circle PCD. However, the dent 54 may extend slightly to the outer diameter side of the cage from the ball arrangement pitch circle PCD, or slightly to the ball arrangement pitch circle PCD. You may not reach it. The ball arrangement pitch circle PCD is also called a pocket PCD.

  The depth of the concave portion 54 is such that the distance Rc from the center O50 of the concave spherical surface of the pocket inner surface to the deepest position of the concave portion 54 is 1.05 times or more the radius of the ball 3 (just 1.05 times). Preferably). The radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 50 is slightly larger than the radius of the ball 3 and is less than 1.05 of the radius of the ball 3.

  FIG. 6 shows another example of the shape of the inner surface of the pocket 50 (spherical shell plate portion 50A) of the cage 4. In this example, two recessed portions 54A provided in the inner diameter side portion 50Ai of the inner surface of the pocket 50 (spherical shell-shaped plate portion 50A) are positioned on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50. It is said. The inner surface shape of each recess 54A is such that the cross-sectional shape along the circumferential direction of the cage (that is, the cross-sectional shape taken along the plane perpendicular to the central axis of the cage) is larger than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 50. It has an arc shape with a small radius of curvature RAb, and in detail, as shown in FIG. 5B, it has a cylindrical surface shape substantially along the surface of each virtual cylinder VA centered on the radial straight line LA of the cage 4. is there. The recessed portion 54A extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower.

The positions of the two recessed portions 54A are, for example, two symmetrical places where the circumferential orientation angle with respect to the center OW50 in the circumferential direction of the cage at the opening edge of the pocket 50 is 40 ° ± 15 °. Also in this example, the depth of the recessed portion 54A is such that the distance RAc from the center O50 of the concave spherical surface of the pocket inner surface to the deepest position of the recessed portion 54A is 1.05 times or more the radius of the ball 3. Is preferable (it may be just 1.05 times).
In this embodiment, the number of the recessed portions 54A is two, but may be three or more.

  FIG. 7 shows still another example of the shape of the inner surface of the pocket 50 (spherical shell plate portion 50A) of the cage 4 (FIG. 1). In this embodiment, in the embodiment of FIG. 6, the cross-sectional shape of the recess 54A (the cross-sectional shape along the circumferential direction of the cage) is a polygonal shape instead of an arc shape. Specifically, as shown in FIG. 5B, a polygonal shape substantially along the surface of each polygonal column (regular decagonal column in the illustrated example) VC centered on the straight line LA in the radial direction of the cage 4. It is. The recessed portion 54C extends from the opening edge on the cage inner diameter side to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the cage inner edge to the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower. Other configurations in this embodiment are the same as those in the example of FIG.

  FIG. 8 shows still another example of the shape of the inner surface of the pocket 50 (spherical shell-like plate portion 50A) of the cage 4. In this example, the recessed portions 54B provided in the inner diameter side portion 50Ai of the inner surface of the pocket 50 (spherical shell-shaped plate portion 50A) are positioned on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50. Although it is the same as that of embodiment of FIG. 6 by being provided in the location, each recessed part 54B is extended to the cage | basket outer-diameter edge vicinity. The cross-sectional shape along the circumferential direction of the cage of the inner surface of the recessed portion 54B is an arc shape having a curvature radius RBb smaller than the curvature radius Ra of the concave spherical surface serving as the inner surface of the pocket 50. FIG. As shown, the shape is substantially along the surface of one virtual ring VB. The virtual ring VB may be an outer peripheral surface of a grindstone that processes the recess 54B. The virtual ring VB has a ring outer diameter that can be accommodated in the pocket 50, and has a donut shape with a circular cross-sectional shape at an arbitrary circumferential position, and the ring center OVB is placed on the cage center axis O as shown in FIG. It has an inclination to it.

In the present invention, the cross-sectional shape along the circumferential direction of the cage of the recessed portions 54A to 54C is not limited to the shape of each example of FIGS. 6 to 8, but a partial oval shape, a rectangular groove shape, a trapezoidal groove shape, Any other cross-sectional shape may be used. In addition, the cross-sectional shape of the recesses 54A to 54C may be asymmetric with respect to the center of the recess.
The inner surface shape of the pocket 50 is not limited to a spherical shape, and may be any shape as long as the inner diameter side portion of the pocket arrangement pitch circle PCD becomes a smaller diameter as it approaches the cage inner diameter side opening edge, for example, the ball arrangement pitch circle PCD. Further, the outer diameter side portion may be a cylindrical surface shape, and the inner diameter side portion may be a conical surface shape.

  FIG. 10 shows a method for manufacturing the cage 4. This manufacturing method is a method of manufacturing an iron plate punching cage, in which a steel plate is first pressed to punch a ring-shaped metal strip 55. Next, as shown in FIG. 10A, a convex press die 56 for molding the inner surface of the spherical shell plate portion 50A of the cage half 51 and the outer surface of the spherical shell plate portion 50A are molded. A press die set 58 composed of the concave press die 57 is prepared, and the ring-shaped metal strip 55 is sandwiched between the convex press die 56 and the concave press die 57, and FIG. The cage half 51 is press-molded as in B). This press molding may be performed in two stages of rough pressing and finishing pressing, or may be performed once.

Although only one convex press die 56 and one concave press die 57 are shown in the drawing, each of the convex press die 56 and the concave press die 57 is a cage half 51. The same number of the spherical shell plate portions 50A are arranged in the circumferential direction as a single mold, and a plurality of spherical shell plate portions 50A are formed at the same time.
The two retainer halves 51 thus obtained are overlapped as shown in FIG. 10C, and a portion where the flat plate portion 51a of the retainer half 51 is overlapped as shown in FIG. To form a cage 4.

  In FIG. 11, the convex side press die 56 and the concave side press die 57 used for the finishing pressing step in press molding are shown for molding the cage half 51 of FIG. The hemispherical convex surface of the convex side press die 56 is partially formed with a concave portion molding die portion 56a for molding the inner surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A). Further, the concave side press mold 57 is partially formed with a concave portion back surface molding die portion 57a for molding the outer surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A). Although a convex part will be formed in the outer surface side of a holder | retainer pocket, if it is non-contact with a seal | sticker, there is no functional problem. In this case, the convex-side press die 56 and the concave-side press die 57 are also provided as a single die corresponding to the number of the spherical shell plate portions 50A of the cage half 51, and have a plurality of spherical shell shapes. The plate portion 50A is formed at the same time.

When the cage half 51 shown in FIG. 6 is formed, the inner surface of the spherical shell plate portion 50A has a shape having a concave portion 54A in a part of a simple hemispherical concave surface. If the concave portion 54A is further press-molded into a part of the hemispherical concave surface after forming the concave shape, the manufacturing process is increased by one step as compared with the case of forming a conventional steel punching cage. .
In this embodiment, as described above, for forming a concave portion, the inner surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A) is formed on the hemispherical convex surface of the convex press die 56 used in the finishing pressing step. Since the mold portion 56a is partially formed, the recessed portion 54A can be formed at the same time in the finishing pushing process, and the cage 4 can be efficiently manufactured without increasing the manufacturing process.

  Further, the shape and surface roughness of the hemispherical convex surface of the convex press die 56 used in the finishing pressing step are transferred to the inner surface of the cage pocket 50, and the pocket inner surface is inserted into the ball 3 ( In order to come into contact with FIG. 1), it is necessary to reduce the surface roughness of the pocket inner surface. Since the inner surface of the pocket is a simple concave spherical surface in the conventional iron plate punching cage, the surface roughness is reduced by polishing the hemispherical convex surface of the convex press die with a concave grinding stone or the like. However, in the case of this embodiment, as described above, the hemispherical convex surface of the convex-side press die 56 is a part of a simple hemispherical convex surface, and a concave portion molding die portion 56a corresponding to the concave portion 54A of the pocket inner surface. The surface roughness cannot be reduced by polishing with a concave-shaped grindstone or the like as in the conventional example.

  Therefore, in this embodiment, the convex convex spherical surface of the convex press die 56 used in the finishing pressing step is surface-finished by shot blasting, polishing with an electron beam, or lapping by injection of an abrasive. In this case, lapping is generated by obtaining abrasive material having elasticity and adhesiveness by adding moisture to the abrasive grains and sliding the abrasive material on the surface of a mold as a workpiece at high speed. A method of surface finishing by frictional force is preferred. As such wrapping, aero wrapping (Yamashi Towers Co., Ltd.) sold as a mold ultra-mirror finishing device can be employed. As described above, the surface of the convex spherical surface of the convex press die 56 is finished by shot blasting, electron beam, or lapping by jetting an abrasive, so that there is no need for manual polishing, and there is no unevenness and low cost. The surface roughness of the convex convex spherical surface of the side press die 56 can be reduced.

12 to 14 show the test results of confirming the grease adhesion state. In this test, a ball bearing incorporating the cage 4 of this embodiment (the embodiment of FIG. 5 and the embodiment of FIG. 6) and a ball bearing incorporating a general iron plate punched cage are shown in the following table. Operation was performed under the conditions of 2 for comparison.
FIGS. 12 and 13 show the grease adhesion state of the ball bearing using the cage 4 of this embodiment (the embodiment of FIG. 5 and the embodiment of FIG. 6 respectively), and FIG. 14 is a general iron plate punching cage. The grease adhesion state of the ball bearing using

From the test results of FIGS. 12 to 14, in the ball bearing (FIG. 14) in which a general steel plate punched cage is incorporated, grease adheres to the inner ring seal groove, but the ball bearing in which the cage 4 of this embodiment is incorporated. (Examples of FIGS. 12 and 13) show that there is no adhesion of grease.
In the rolling bearing cage 4 according to this embodiment, the shape of the pocket 50 is different from that of the conventional example as described above, so that the adhesion of grease to the shoulder portion of the inner ring can be eliminated. In other words, since a recess is provided at the opening edge on the inner diameter side of the cage, where the grease adheres most to the ball, scraping of the surface of the ball when grease scraping occurs reduces the inner diameter of the cage. The amount of grease that accumulates on the surface is reduced.

  Therefore, grease does not adhere to the inner ring seal groove, and no grease leakage occurs regardless of whether a contact type or non-contact type seal is used. This effect is characteristic especially when the outer ring rotates. Therefore, there is no problem caused by the grease adhering to the seal unlike a general iron plate punched cage. Furthermore, since it is not necessary to add an element for preventing grease leakage to the sealing function, a seal design specialized for muddy water resistance, dust resistance, and low torque is possible. Further, since the ball bearing retainer 4 of this embodiment can be pressed, a high-strength one can be manufactured at a low cost, and the distance from the seal does not change as compared with a general iron punching retainer.

  In each of the above-described embodiments, an iron plate punched cage is shown, but the present invention can also be applied to a resin cage 59 as shown in FIGS. 15 and 16. The resin cage 59 has two annular bodies 60, 60 made of a resin molded product. A plurality of hemispherical pockets 61A along the outer periphery of the ball are formed at equal intervals in the circumferential direction on one side surface of each annular body 60 that abuts each other. Between the adjacent pockets 61 </ b> A and 61 </ b> A, an engagement hole 62 and an engagement claw 63 serving as a coupling portion are provided, and the engagement claw 63 of one annular body 60 is connected to the engagement hole 62 of the other annular body 60. By inserting, both annular bodies 60 are joined together to form a cage 59.

According to the configuration of the rolling bearing described above, the cages 4 and 59 have pockets 50 that respectively hold a plurality of balls 3 at a plurality of locations in the circumferential direction, and the inner surfaces of the pockets 50 are arranged in a ball arrangement pitch circle. A portion on the inner diameter side than the PCD has a ring shape with a concave curved surface that becomes a smaller diameter as it approaches the opening edge on the inner diameter side of the cage, and the inner diameter of each pocket 50 from the opening edge on the inner diameter side of the cage to the outer diameter of the cage Since the recesses 54 (54A, 54B, 54C) extending to the side are provided, it is difficult for grease to adhere to the seal groove 9 of the inner ring 1, and grease leakage can be prevented. Thus, since grease does not leak from the bearing, the life of the bearing can be extended. In addition, the leaked grease does not adhere to the belt or the like, preventing the occurrence of belt squealing and preventing the belt from being damaged.
By applying the cages 4 and 59 and the grease composition, the bearing can be operated without hydrogen embrittlement and there is no grease leakage, so that the lubrication life characteristics of the enclosed grease can be sufficiently exerted. . Furthermore, external contamination problems such as abnormal noise due to erosion and slipping on the engine accessory belt due to grease leakage are also eliminated.

  Since grease leakage does not occur by using the cage, the seal does not need to be a contact type, in other words, the seal member 5 is a non-contact type, and torque can be reduced. Further, according to the configuration of this rolling bearing, it is not necessary to secure a space for providing a protruding portion or a slinger in the axial direction of the bearing, and the number of parts can be reduced from that described in the above-mentioned patent document, thereby reducing the manufacturing cost. it can.

  For example, as shown in FIG. 5, the recessed portion 54 is provided at one position so as to spread from the center in the circumferential direction of the cage at the opening edge of the pocket 50 to a width W50 in the circumferential direction of the cage 50. The inner surface shape of the recess 54 is a cylindrical surface shape substantially along the surface of the virtual cylinder V centered on the straight line L in the radial direction of the cage 4. The recess 54 extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD, and gradually becomes shallower and narrower as it approaches the ball arrangement pitch circle PCD from the inner diameter edge of the cage. Thus, the above-described actions and effects are achieved.

  In addition, as shown in FIG. 6, for example, as shown in FIG. 6, the recessed portions 54 </ b> A are provided at a plurality of locations on both sides of the center OW <b> 50 in the cage circumferential direction at the opening edge of the pocket 50. The concave portion 54A extends from the opening edge on the inner diameter side of the cage to the ball arrangement pitch circle PCD. The cylindrical surface shape is substantially along the surface of each virtual cylinder VA around the straight line LA in the radial direction of the cage 4. The shape is gradually shallower and narrower as it approaches the ball arrangement pitch circle PCD from the inner diameter edge of the cage, thereby providing the above-described operations and effects.

  Further, as shown in FIGS. 8 and 9, for example, as shown in FIGS. 8 and 9, the recessed portions 54 </ b> B are provided at two locations on both sides of the center OW50 in the circumferential direction of the cage at the opening edge of the pocket 50. The inner surface shape of these two recessed portions 54B extends to the vicinity of the edge, and is substantially along the surface of one virtual ring VB. The virtual ring VB has a ring outer diameter that fits in the pocket 50, and has an arbitrary circumference. The cross-sectional shape of the directional position is circular, and the ring center OVB has an inclination with respect to the cage center axis O, so that the above-described operations and effects are achieved.

17 to 19 show an embodiment corresponding to the second invention. The rolling bearing retainer 4A according to this embodiment is the same as the retainer 4 described above with reference to FIGS.
This retainer 4A is a retainer used for the rolling bearing described above with reference to FIG. 1 and has a ring shape having pockets 50 for retaining the balls 3 in a plurality of positions in the circumferential direction, and retains two annular bodies. The container half 51 is overlapped facing each other in the axial direction. Each of these cage halves 51 has a shape in which spherical shell-shaped plate portions 50A whose inner surfaces form half of the respective pockets and flat plate portions 51a that are portions between adjacent pockets 50 are alternately arranged in the circumferential direction. Is done. Each cage half 51 is a press-formed product of a metal plate (for example, an iron plate punched product), and the two cage halves 51 are mutually connected by a rivet 53 inserted into a rivet hole 52 provided in the flat plate portion 51a. Joined and constructed integrally. The above configuration is the same as that of the embodiment shown in FIGS.
As shown in FIGS. 17 and 19, the retainer 4 </ b> A has a range that overlaps the outer diameter surface portion 1 b that is the shoulder height on both sides of the raceway surface 1 a of the inner ring 1 in the axial direction.

  The cage 4A of this embodiment has a thin portion 50Aa in the inner diameter side portion of the ball arrangement pitch circle PCD which is the ball arrangement pitch in the spherical shell plate portion 50A in the above configuration. The thin portion 50Aa is obtained by making the plate thickness t1 of the portion located on the outer diameter surface portion 1b, which is the shoulder height on both sides of the raceway surface 1a of the inner ring 1, smaller than the plate thickness t0 of the flat plate portion 51a. The outer diameter surface portion 1b serving as the shoulder height is an outer diameter surface portion continuing at the height of the shoulder portion of the raceway surface 1a of the inner ring 1, and when the seal groove 9 is provided, the raceway surface 1a and the seal groove are provided. 9 is an outer diameter surface portion between 9. The spherical shell plate portion 50A reduces the thickness t1 of the portion located in the axial range W of the outer diameter surface portion 1b. In FIG. 17, the cross-sectional shape when the spherical shell-shaped plate portion 50A is not thinned is indicated by an imaginary line.

  The plate material t1 may be thinned by thinning the entire range from the portion corresponding to the ball arrangement pitch circle PCD to the inner diameter side in the radial direction of the cage, and between the ball arrangement pitch circle PCD and the cage inner edge. The range from the midway point to the inner diameter edge may be made thinner. In these cases, the plate thickness t1 may gradually become thinner toward the inner diameter side in the radial direction of the cage so that the inner diameter edge becomes the minimum plate thickness. You may do it. Furthermore, while maintaining the shape of the inner surface of the pocket of the spherical shell-shaped plate portion 50A, even if the plate thickness is reduced so that the shape of the outer surface changes, or while maintaining the shape of the outer surface of the spherical shell-shaped plate portion 50A, The plate thickness may be reduced so that the shape on the inner surface side of the pocket changes.

  Further, in this embodiment, as shown in FIG. 18, both ends are left thin in the arc-shaped range along the inner diameter edge of the spherical shell-like plate portion 50 </ b> A. Depending on the relationship between the outer diameter surface portion 1b and the width of the retainer 4A, as shown in FIG. 20, the thin portion 50Aa with a reduced plate thickness is on both sides except the center of the arc of the inner diameter edge of the spherical shell plate portion 50A. It may be divided into two places.

  In this cage 4A, a thin-walled portion 50Aa is formed on the inner diameter portion of the spherical shell-shaped plate portion 50A constituting the pocket 50 in this way, and this thin-walled portion 50Aa is the outer-diameter surface portion of the inner ring 1 at the height of the shoulder portion. It is a part which overlaps with 1b in an axial direction, Comprising: It is a part from which the grease adhering to the surface of the ball | bowl 3 is scraped off with the holder | retainer 4A, or the scraped grease moves. If the plate thickness t1 of the portion 50Aa is thin, the amount of grease that can be deposited here decreases, so the frequency and amount that can reach the outer diameter surface portion 1b of the inner ring 1 is reduced, and as a result, the grease flows to the outside of the bearing. Leakage can be prevented. That is, the grease easily moves to the outer diameter side of the cage 4A, and the amount of grease that can stay on the inner diameter side decreases.

However, reducing the overall plate thickness of the cage reduces the strength of the cage alone, so that the cage may be damaged when repeated stress is applied to the cage under misalignment or external vibration. It is difficult to occur.
Therefore, in the inner diameter portion of the cage 4A, the plate thickness is reduced only in the range W that overlaps the outer diameter surface portion 1b serving as the shoulder portion of the inner ring 1 in the axial direction, thereby substantially increasing the strength of the cage 4A. A ball bearing retainer 4A that does not drop and can prevent grease leakage is established. Thus, since grease does not leak from the bearing, the life of the bearing can be extended. In addition, the leaked grease does not adhere to the belt or the like, preventing the occurrence of belt squealing and preventing the belt from being damaged.

  Since the grease leakage does not occur by using the cage 4A, it is not necessary to make the seal a contact type. In other words, the seal member 5 can be made a non-contact type and the torque can be reduced. Further, according to the configuration of this rolling bearing, it is not necessary to secure a space for providing a protruding portion or a slinger in the axial direction of the bearing, and the number of parts can be reduced from that described in the above-mentioned patent document, thereby reducing the manufacturing cost. it can. By applying the cage 4A and the grease composition, the bearing can be operated without hydrogen embrittlement and there is no grease leakage, so that the lubrication life characteristics of the enclosed grease are sufficiently exhibited. Furthermore, external contamination problems such as abnormal noise due to erosion and slipping on the engine accessory belt due to grease leakage are also eliminated.

  In order to reduce the plate thickness t1, only the inner diameter side of the flat plate initially punched into the ring may be thinned and press molded. Further, in a press mold when a cage is formed by pressing from an annular flat plate having a uniform thickness, the clearance distribution between a pair of molds is reduced so that only the thickness of the region shown in FIGS. 18 and 20 decreases. It may be changed. Further, in this embodiment, the case of a deep groove ball bearing punch made of iron plate is shown, but the second invention can also be applied to the two-part resin cage described above with reference to FIGS. .

  21 to 23 show an embodiment of the present invention. The rolling bearing cage 4B according to this embodiment is a cage used in the rolling bearing described above with reference to FIG. The retainer 4B is a ring-shaped member, and the same number of window-like pockets 4Ba for accommodating and holding the ball 3 (FIG. 1) as the balls 3 are formed at equal intervals in the circumferential direction. The inner circumferential surface 4Bb of the circumferential portion with the pocket 4Ba is inclined so as to be recessed toward the outer diameter side, and the radius Rp from the cage center of the inner diameter of the circumferential portion with the pocket 4Ba is between the pockets 4Ba. Is larger than the radius Ri from the center of the cage (Rp> Ri). In this embodiment, the inner peripheral surface 4Bb has a curved surface shape that is a concave curve when viewed from the axial direction, specifically, an arcuate surface.

  The cage 4B is composed of, for example, two annular members 64 manufactured by punching and forming an iron plate by pressing. Each annular member 64 is arranged in the circumferential direction at equal intervals, and a plurality of hemispherical pocket wall portions 64a each constituting the inner wall surface of the pocket 4Ba and a flat plate-like coupling plate that connects adjacent pocket wall portions 64a to each other. The portions 64b are alternately formed. A rivet hole 64c is formed in the coupling plate portion 64b of the annular member 64 made of iron plate. The two annular members 64 are joined by overlapping the respective coupling plate portions 64b with each other, inserting a rivet 65 into the rivet hole 64c, and crimping both ends of the rivet 65. In this way, if the two annular members 64 are coupled to each other to form one cage 4B, the radius from the cage center having the inner diameter as described above is different in each part, but is retained. The processing of the vessel 4B is easy.

  The cage 4B of this embodiment has a shape in which the inner peripheral surface 4Bb of the circumferential direction portion with the pocket 4Ba is recessed toward the outer diameter side, so there is a concern that the overall strength may be lowered. However, most of the damage of the conventional standard shape cage Hr (Rp = Ri) as shown in FIG. 27 is the R portion from the circumferential portion between the pockets Hra to the circumferential portion with the pockets Hra. It is empirically known to occur with Hr7. Since the cage 4B of this embodiment does not change the shape of this portion, it can be said that the overall strength does not decrease.

  In order to investigate the state of grease during operation of this rolling bearing, a test was conducted under the conditions shown in Table 3. FIG. 23 shows the state of the grease adhering to each part of the bearing after the operation was stopped. For comparison, the bearing incorporating the conventional cage Hr shown in FIG. 27 was also tested under the same conditions. The state of adhesion of grease to each part of the bearing after the operation was stopped was as shown in FIG.

  According to this test, the grease G adheres to the inner ring seal groove Hr1a in the case of the bearing incorporating the conventional cage Hr. However, in the rolling bearing incorporating the cage 4 of the present invention, the grease does not adhere to the inner ring seal groove. I understood. For this reason, it is inferred that in a rolling bearing provided with a seal, leakage of grease from the inner ring seal groove due to breathing can be prevented.

  Next, a grease leakage frequency confirmation test was performed using a bearing assembled with a contact-type seal (LU seal manufactured by NTN Corporation). For the test conditions, only the operation time was changed to 15 minutes with respect to the conditions in Table 3. When it was confirmed by visual inspection that grease of an amount of about 30 to 100 mg had jumped out of the bearing, grease leakage was assumed. The test results are shown in Table 4.

  Nine out of 10 grease leaks were found in the bearings incorporating the conventional cage Hr, but none of the bearings incorporating the cage 4 of the present invention produced any grease leaks. This proved that the reasoning was correct.

In the above embodiment, the two annular members 64 constituting the cage 4B are made of iron plate, but the annular member 64 may be made of resin. In this case, as in the cage 4C shown in FIGS. 24 and 25, the coupling plate portion 64b is provided with the engagement claw 66 and the engagement hole 67, and the two 66 and 67 are fitted to each other, thereby providing two sheets. It can be set as the structure which couple | bonds the annular member 64. FIG. Also in this case, the radius Rp from the cage center at the inner diameter of the circumferential portion with the pocket 4Ca is made larger than the radius Ri from the cage center at the inner diameter of the circumferential portion between the pockets 4Ca (Rp> Ri). . Further, two annular members 64 made of resin may be joined with an adhesive or the like.
As the synthetic resin material used for the cage, for example, polyamide resins such as PA66 and PA46 and polyphenyl sulfide resins are suitable, and a reinforcing fiber material such as glass fiber may be mixed as necessary.
Further, the structure is not limited to a structure in which the two annular members 64 are joined to form a single retainer, but may be a machined retainer that cuts out a steel material into a predetermined shape, or a molded retainer that is integrally molded with a resin material. It is good also as a vessel.

  FIG. 26 shows a different embodiment. In the retainer 4D, the shape of the inner peripheral surface 4Db in the circumferential portion with the pocket 4Da is a polygonal shape when viewed from the axial direction. Specifically, the inner peripheral surface 4Db includes a pair of inclined surface portions 4Dba that are inclined toward the outer diameter side with respect to the inner peripheral surface 4Dc in the circumferential portion between the pockets 4Da, and both ends of the outer peripheral surfaces 4Dba are outside the pair of inclined surface portions 4Dba. It has a trapezoidal shape composed of a constant-diameter surface portion 4Dbb that is connected to the radial end and has a constant inner diameter. Similarly to the cages 4B and 4C of the above-described embodiment, the cage 4D is inclined so that the inner circumferential surface 4Db of the circumferential portion with the pocket 4Da is recessed in the outer diameter side, and the pocket 4Da The radius Rp from the cage center of the inner diameter of a certain circumferential portion is larger than the radius Ri from the cage center of the inner diameter of the circumferential portion between the pockets 4Da (Rp> Ri).

  In this way, the cage 4D having a polygonal shape when viewed from the axial direction in the inner circumferential surface 4Db of the circumferential portion having the pocket 4Da is also reduced in overall strength, like the cages 4B and 4C of the above embodiment. When it is incorporated in a rolling bearing as shown in FIG. 1, leakage of grease from the inner ring seal groove portion of the bearing can be prevented.

  In addition, when making inner peripheral surface 4Db of the circumferential direction part with pocket 4Da into the polygonal shape which has a some corner | angular part, the number of the corner | angular part is not specifically limited. Further, the shape may be asymmetric with respect to a straight line in the radial direction. Furthermore, the inner peripheral surface 4Db of the circumferential direction portion with the pocket 4Da may be a combination of a flat surface and a curved surface.

In short, regardless of the material and processing method of the present invention, the radius from the cage center of the inner diameter of the circumferential portion with the pocket is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets. It can be applied to a cage having a shape that satisfies the condition of large.
As described above, in the rolling bearing, the cage incorporated in the bearing has a radius from the center of the inner diameter of the circumferential portion having the pocket, and the inner diameter of the circumferential portion between the pockets. By making it larger than the radius from the center, it becomes difficult for grease to adhere to the inner ring shoulder and the inner ring seal groove. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. That is, it is possible to apply a non-contact type seal, and it is possible to reduce the torque. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase. Each of the above-described actions can be obtained in any case where the inner diameter surface of the circumferential portion having the pocket is a curved surface having a concave curve when viewed from the axial direction, or a polygonal shape having a plurality of corners.

  By applying at least one of the cages 4B, 4C, 4D and the grease composition to a rolling bearing, the bearing can be operated without hydrogen embrittlement, and there is no grease leakage. The lubrication life characteristics of grease are fully demonstrated. Furthermore, external contamination problems such as abnormal noise due to erosion and slipping on the engine accessory belt due to grease leakage are also eliminated.

  Here, FIG. 29 is a cross-sectional view in which a bearing according to an embodiment of the present invention is provided in an idler pulley. In this embodiment, the same bearing is fitted to the outer periphery of the shaft Sh, and the pulley PL is rotatably supported by this bearing. According to this idler pulley bearing, since the above-mentioned cage is provided and the above grease composition is enclosed, the bearing can be operated without hydrogen embrittlement and there is no grease leakage. Life characteristics are fully demonstrated. In addition, the life of the bearing can be extended.

  FIG. 30 is a cross-sectional view in which a bearing according to an embodiment of the present invention is provided in an alternator. In this embodiment, in the alternator ONT, the shaft Sh1 is inserted into the alternator bearings NN1 and NN2, and the pulley PL is attached to the protruding end. The pulley 1PL is provided with an engagement groove PL1 on which a transmission belt (not shown) is hung. According to the alternator bearings NN1 and NN2, by providing the above-mentioned retainer and enclosing the grease composition, the bearing can be operated without hydrogen embrittlement and there is no grease leakage. The lubrication life characteristics that it has are fully demonstrated. In addition, the life of the bearing can be extended.

It is sectional drawing of the rolling bearing concerning one Embodiment of this invention. It is a perspective view of the holder | retainer of this embodiment. It is a perspective view of the retainer half which is a structural member of the retainer. It is a partial expansion perspective view which simplifies and shows a pocket shape about a part of the cage half. (A) is a partial enlarged perspective view highlighting an example of the inner surface of the spherical shell plate portion in the cage half, and (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. (A) is a partial enlarged perspective view highlighting another example of the inner surface of the spherical shell plate in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. is there. (A) is a partial enlarged perspective view highlighting still another example of the inner surface of the spherical shell plate portion in the cage half, and (B) is a perspective view showing a state in which a virtual polygonal column is added to the perspective view. FIG. (A) is a partial enlarged perspective view highlighting still another example of the inner surface of the spherical shell plate portion in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view It is. It is explanatory drawing which shows the relationship between the spherical shell-shaped board part and a virtual ring in a cross section. It is explanatory drawing which shows the manufacturing process of the holder | retainer of this embodiment. It is a perspective view of the press die set used for the manufacturing process. It is explanatory drawing of the result of the grease leak test of the rolling bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the rolling bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the general iron plate punching cage. It is a disassembled perspective view of the resin-made cage to which the cage of this embodiment is applicable. It is sectional drawing of the resin cage. It is a partially broken perspective view of the rolling bearing incorporating the retainer concerning other embodiments of this invention. It is a partial expansion perspective view which shows the spherical shell-shaped board part in the cage half body of the same cage. It is a top view which shows the assembly which integrated the holder | retainer of the embodiment in the inner ring | wheel. It is a partial expansion perspective view which shows the modification of the spherical shell-shaped board part in the cage half body of the same cage. It is a front view of the holder | retainer integrated in the rolling bearing concerning one Embodiment of this invention. It is AA sectional drawing of FIG. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer. It is a front view of a different holder. It is a disassembled perspective view which shows the principal part of the annular member of the holder. It is a front view of the holder | retainer concerning different embodiment of this invention. It is a front view of the conventional cage | basket. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer. It is sectional drawing which provided the bearing concerning one Embodiment of this invention in the idler pulley. It is sectional drawing which provided the bearing concerning one Embodiment of this invention in the alternator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 2 ... Outer ring 3 ... Ball | bowl 4, 4A, 4B ... Cage 4Ba ... Pocket 5 ... Seal member 50 ... Pocket 54, 54A, 54B ... Recessed part Gs ... Grease composition PCD ... Ball arrangement pitch circle Ri, Rp ... radius

Claims (5)

A rolling bearing in which a plurality of balls interposed between inner and outer rings are held by a cage, a grease composition is sealed in a bearing space between the inner ring and the outer ring, and the bearing space is closed by a seal member provided on the outer ring or the inner ring. In
The grease composition is formed by adding an additive to a base grease composed of a base oil and a thickener, and the additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound. And the compounding ratio of this aluminum-type additive is 0.05 weight part or more and 10 weight part or less with respect to 100 weight part of base grease,
The cage has pockets for holding a plurality of balls at a plurality of locations in the circumferential direction, and the inner surface of each pocket is closer to the inner diameter side opening edge of the cage than the ball arrangement pitch circle. A ring-shaped cage having a concave curved surface shape having a small diameter according to the above, wherein the inner surface of each pocket is provided with a recessed portion extending from the opening edge on the cage inner diameter side to the cage outer diameter side. bearing. A rolling bearing in which a plurality of balls interposed between inner and outer rings are held by a cage, a grease composition is sealed in a bearing space between the inner ring and the outer ring, and the bearing space is closed by a seal member provided on the outer ring or the inner ring. In
The grease composition is formed by adding an additive to a base grease composed of a base oil and a thickener, and the additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound. And the compounding ratio of this aluminum-type additive is 0.05 weight part or more and 10 weight part or less with respect to 100 weight part of base grease,
The cage has pockets for holding a plurality of balls at a plurality of locations in the circumferential direction, and the radius from the cage center of the inner diameter of the circumferential portion with the pockets is set to the circumferential portion between the pockets. A rolling bearing characterized by having a larger inner diameter than the radius from the cage center.   3. The rolling bearing according to claim 1, wherein the aluminum compound is at least one compound selected from aluminum carbonate or aluminum nitrate.   The rolling bearing according to any one of claims 1 to 3, wherein the thickener is a urea thickener.   5. The rolling bearing according to claim 1, wherein the base oil is at least one oil selected from alkyl diphenyl ether oil and poly-α-olefin oil.

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