JP2015178904A - Rolling bearing and manufacturing method of rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing which can suppress early exfoliation resulting from hydrogen embrittlement.SOLUTION: A rolling bearing comprises an outer ring 11 and an inner ring 12 having circular raceways, and a plurality of balls 13 which contact with the outer ring 11 and the inner ring 12, and are rollingly arranged on the circular raceways. At least one bearing member out of the outer ring 11, the inner ring 12 and the balls 13 is formed according to a JIS standard SUJ2. The bearing member is quenched. The bearing member has rolling faces 11A, 12A and 13A which are applied with nitriding treatment. A depth of an impression which is formed at the bearing member by pressing an SUJ2-standard rolling bearing steel ball whose diameter is 19.05 mm against the bearing member at a load of 3.18 kN, and removing the load after holding it for ten seconds is not deeper than 0.2 μm. The Rockwell C-scale hardness of the rolling faces 11a, 12A and 13A is not lower than HRC61.2 and not higher than HRC63.3.

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing in which at least one bearing member of a raceway member and a rolling element is made of JIS standard SUJ2, and a method for manufacturing the rolling bearing.

  When rolling bearings are used under conditions where water is mixed, slipping, or energized, hydrogen generated by decomposition of water or lubricant will enter the steel of the raceway member and rolling element. Doing so may cause early peeling. Since hydrogen significantly reduces the fatigue strength of steel, even in conditions that are considered to be elastohydrodynamic lubrication in which the contact element between the raceway member and rolling element is divided by an oil film, the alternating shear stress of the contact element is maximized inside the rolling surface layer. Cracks may occur. This crack may propagate and lead to early peeling. In the future, in order to cope with downsizing and energy saving, the usage conditions of rolling bearings tend to become more severe, such as conditions where water is mixed, conditions involving slippage, and conditions where energization occurs. Therefore, it is expected that a rolling bearing having excellent hydrogen embrittlement resistance will be required.

  As a conventional technique for improving the hydrogen embrittlement resistance of a rolling bearing, for example, Japanese Patent Application Laid-Open No. 2000-282178 (Patent Document 1) discloses a passive film having a predetermined Cr (chromium) content in a steel material. It is disclosed that the entry of hydrogen into a steel material is suppressed by forming a chromium oxide film with a predetermined thickness.

  It is also known that nitriding treatment is effective for strengthening steel. For example, in the paper “Evaluation of indentation-origin type peeling life by artificial marking of carbonitrided SUJ2 steel with precisely controlled nitrogen concentration in steel” (Non-Patent Document 1), the indentation-initiated type of steel with precisely controlled nitrogen concentration A peel life assessment is disclosed.

JP 2000-282178 A

Oki et al., “Indentation Origin Type Peel Life Evaluation by Artificial Marking of Carbonitrided SUJ2 Steel with Accurately Controlling Nitrogen Concentration in Steel,” Iron and Steel, October 2009, Vol. 95, no. 10, pp. 695-703

  In the above-mentioned publication, carbide is coarsened by adding a large amount of Cr in order to set the Cr content to a predetermined value, which may become a stress concentration source and cause early separation. In addition, the passive film has an effect of slowing the diffusion of hydrogen, but also has an effect of promoting the adsorption of the generated hydrogen on the steel surface. Therefore, in the case of a rolling bearing that is used intermittently, hydrogen is dissipated at the time of stoppage. Therefore, it is considered effective to suppress early separation by delaying the penetration of hydrogen into the steel by the passive film. However, in the case of a rolling bearing that is used continuously, the passive film adsorbs a lot of hydrogen, so that the amount of hydrogen that penetrates into the steel increases, so that there is a high possibility that early separation will occur. In the future, it is expected that the number of rolling bearings that are continuously operated unattended will increase. In the prior art, suppression of early peeling is insufficient particularly for such applications.

  Moreover, the special steel material which made the content rate of Cr predetermined value has the problem that cost becomes high. Moreover, there is a problem that it is difficult to procure a special steel material having a predetermined Cr content.

  Further, in the above paper, hydrogen embrittlement resistance is not studied, so that hydrogen embrittlement cannot be improved.

  Further, the heat generation of the bearing causes thermal expansion of the shaft, which is one of the causes of deterioration of machining accuracy. For example, in a rolling bearing for a main spindle of a machine tool used at a high speed in a machine tool such as a machining center, it is important to reduce the torque in order to avoid heat generation during the high speed rotation. For this reason, the rolling bearings for machine tool main spindles reduce the amount of lubricating oil as much as possible in order to reduce the friction torque of the bearings that causes heat generation. For this reason, the oil film thickness is reduced as compared with the case where sufficient lubricating oil is supplied, and the shear stress of the lubricating oil due to slip increases, so that hydrogen is likely to be generated. In addition, angular ball bearings are frequently used as rolling bearings for machine tool spindles. In angular ball bearings, slip always occurs between the rolling elements (balls) and the race members (race rings). Further, in actual use, it is inevitable that coolant enters the raceway member and the rolling element. In the case of water-soluble coolant, the entry of the coolant is nothing but water mixing. Therefore, in a rolling bearing for a machine tool main shaft, early peeling is likely to occur due to hydrogen penetrating into steel.

  This invention is made | formed in view of the said subject, The objective is to provide the rolling bearing which can suppress the early peeling resulting from hydrogen embrittlement.

  As a result of intensive studies, the present inventor has made the atomic vacancies difficult to plastically deform by nitriding the rolling surface of at least one bearing member of the race member and the rolling element and optimizing the tempering temperature of the bearing member. It has been found that the hydrogen embrittlement resistance of a rolling bearing is improved by making it difficult to generate the. The present inventor has selected high-carbon chromium bearing steel SUJ2 (JIS standard) most frequently used for rolling bearings as the bearing member and at least one of the rolling elements in view of the cost and availability of the material.

  The inventor optimized the tempering temperature in order to improve hydrogen embrittlement resistance after nitriding the rolling contact surface of the bearing member and quenching. By subjecting the rolling surface of the bearing member to nitriding treatment, the bearing member is hardly plastically deformed. The present inventor has found that the hydrogen embrittlement resistance of the bearing member is improved by performing nitriding treatment on the rolling surface of the bearing member to make the bearing member difficult to be plastically deformed.

  The basis for optimizing the tempering temperature is based on the theory of hydrogen-assisted strain-induced vacancies, which is a powerful hydrogen embrittlement mechanism. The number of vacancies increases due to plastic deformation, but this theory is based on the fact that it has been found by systematic experiments that when hydrogen is involved, it increases the vacancy density. The inventor paid attention to this theory and found that hydrogen embrittlement resistance was improved by optimizing the tempering temperature.

  The rolling bearing of the present invention includes a raceway member having an annular raceway and a plurality of rolling elements that are in contact with the raceway member and are arranged so as to be freely rollable on the annular raceway. At least one bearing member of the race member and the rolling element is made of JIS standard SUJ2. The bearing member is quenched. The bearing member has a nitriding rolling surface. By pressing a steel ball for SUJ2 standard rolling bearings with a diameter of 19.05 mm on the bearing member with a load of 3.18 kN, holding it for 10 seconds and then unloading it, the depth of the impression formed on the bearing member is 0.2 μm or less. is there. The Rockwell C scale hardness of the rolling surface is HRC61.2 or more and HRC63.3 or less.

  By subjecting the rolling surface of the bearing member to nitriding treatment, the bearing member is hardly plastically deformed. By subjecting the rolling surface of the bearing member to nitriding treatment, the bearing member is less likely to be plastically deformed, thereby improving the hydrogen embrittlement resistance of the bearing member.

  Moreover, the atomic vacancy density increases due to plastic deformation. The indentation depth indicates the difficulty of plastic deformation. In other words, if the indentation depth is small, it can be said that plastic deformation is difficult. If the indentation depth is 0.2 μm or less as a guide, it can be said that plastic deformation is difficult. Therefore, when the relationship between the tempering temperature and the indentation depth was investigated in detail, if a tempering process was performed at 240 ° C. or higher and 300 ° C. or lower, a SUJ2 standard rolling bearing steel ball with a diameter of 19.05 mm was loaded on the bearing member. It was found that the depth of the indentation formed on the bearing member was 0.2 μm or less by unloading after pressing at 3.18 kN and holding for 10 seconds.

  Further, it was found that the Rockwell C scale hardness of the rolling surface of the bearing member in the range of tempering temperature 240 ° C. or higher and 300 ° C. or lower is HRC 61.2 or higher and HRC 63.3 or lower.

  Therefore, by tempering the bearing member having a rolling surface subjected to nitriding treatment at a tempering temperature of 240 ° C. or higher and 300 ° C. or lower, it is difficult to plastically deform and to make it difficult to generate atomic vacancies. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  In the above rolling bearing, the surface nitriding concentration of the rolling surface is preferably 0.05% by mass or more and 0.4% by mass or less.

  If the surface nitridation concentration of the rolling surface is less than 0.05% by mass, the effect of improving the life by nitriding cannot be obtained sufficiently. If the surface nitridation concentration on the rolling surface is larger than 0.4% by mass, a large amount of Cr carbonitride is produced, so that the Cr amount contributing to hardenability is deficient. Therefore, sufficient hardenability cannot be ensured. Therefore, when the surface nitridation concentration of the rolling surface is 0.05 mass% or more and 0.4 mass% or less, the effect of improving the life by nitriding can be sufficiently obtained, and sufficient hardenability is ensured. You can also.

  The present inventor has selected JIS standard SUJ2 which is not nitrided in consideration of productivity as a rolling element. If the indentation depth is 0.2 μm or less as a guide, it can be said that plastic deformation is difficult. Therefore, when the relationship between the tempering temperature and the indentation depth was investigated in detail, if a tempering treatment was performed at 240 ° C. or higher and 280 ° C. or lower, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm was loaded on the rolling element. It was found that by pressing at 1.97 kN and holding for 10 seconds before unloading, the depth of the indentation formed on the rolling element was 0.2 μm or less. Therefore, by performing tempering at a tempering temperature of 240 ° C. or higher and 280 ° C. or lower, it is difficult to plastically deform and make it difficult to generate atomic vacancies. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  In the rolling bearing described above, the Rockwell C scale hardness of the entire rolling element is preferably HRC57.0 or more and HRC58.9 or less. The Rockwell C scale hardness of the whole rolling element in the range of tempering temperature 240 or more and 280 or less is HRC57.0 or more and HRC58.9 or less.

  In the above rolling bearing, the rolling element is preferably made of a material containing ceramics. According to the rolling bearing of the present invention, since the rolling element is made of a material containing ceramics that does not exhibit hydrogen embrittlement, the hydrogen embrittlement resistance can be improved, so that early separation due to hydrogen embrittlement can be suppressed.

  Preferably, the rolling bearing further includes a cage for holding the rolling elements, and the cage is made of a material containing metal. According to the rolling bearing of the present invention, under the condition where energization occurs, the metal cage is less likely to cause early peeling due to hydrogen embrittlement than the resin cage, and therefore, early peeling due to hydrogen embrittlement can be suppressed.

  According to the method of manufacturing a rolling bearing of the present invention, the rolling bearing includes a raceway member having an annular raceway, and a plurality of rolling elements that are in contact with the raceway member and are arranged to be freely rollable on the annular raceway. It has the process of. At least one bearing member of the race member and the rolling element is prepared to be made of a material of JIS standard SUJ2. The rolling surface of the bearing member is subjected to nitriding treatment and quenched. The quenched bearing member is tempered at 240 ° C. or higher and 300 ° C. or lower.

  The bearing member is hard to be plastically deformed by performing nitriding treatment and quenching on the rolling surface of the bearing member. By subjecting the rolling surface of the bearing member to nitriding treatment and making the bearing member difficult to plastically deform, the hydrogen embrittlement resistance of the bearing member is improved.

  By tempering the quenched bearing member at 240 ° C. or higher and 300 ° C. or lower, the bearing member is less likely to be plastically deformed, and it is possible to make it difficult to generate atomic vacancies. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  In the above rolling bearing manufacturing method, the nitriding treatment is preferably performed at a temperature of 850 ° C. in an atmosphere in which ammonia gas is added to RX gas. Thereby, sufficient nitriding treatment is performed on the rolling surface of the bearing member to make the bearing member difficult to be plastically deformed, so that the hydrogen embrittlement resistance of the bearing member can be improved.

  Preferably, the rolling bearing further includes a main shaft of the motor and a housing disposed so as to face the outer peripheral surface of the main shaft, and the main shaft is rotatably supported with respect to the housing.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. It is possible to provide a rolling bearing for a simple motor.

  Preferably, the rolling bearing further includes a main shaft of the machine tool and a housing disposed so as to face the outer peripheral surface of the main shaft, and the main shaft is rotatably supported with respect to the housing.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. A rolling bearing for a main spindle of a machine tool can be provided. Further, it is possible to provide a rolling bearing for a machine tool spindle that has a long life even under use conditions in which the oil film thickness of the lubricating oil is reduced in order to reduce the friction torque of the bearing that causes heat generation during high-speed rotation.

  Preferably, the rolling bearing further includes a rotation-side member of the wheel and a fixed-side member disposed so as to face the outer peripheral surface of the rotation-side member, and the rotation-side member is rotatable with respect to the fixed-side member. To support.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. A rolling bearing for a wheel can be provided. Further, since the early peeling due to hydrogen embrittlement can be suppressed even under conditions where the bearing vibrates, a long-life wheel rolling bearing can be provided.

  Preferably, the rolling bearing further includes a main shaft of the alternator and a housing disposed so as to face the outer peripheral surface of the main shaft, and the main shaft is rotatably supported with respect to the housing.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. A rolling bearing for an alternator can be provided. Providing rolling bearings for alternators that have a long life by suppressing early delamination due to hydrogen embrittlement, especially under operating conditions where sliding due to hydrogen embrittlement is likely to occur due to the effect of slippage between contact elements under rapid acceleration / deceleration conditions can do. In addition, it is possible to suppress the early peeling due to hydrogen embrittlement even under conditions where slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine formation, so a rolling bearing for an alternator with a long life is provided. Can do.

  Preferably, the rolling bearing further includes a main shaft and a pulley main body disposed so as to face the outer peripheral surface of the main shaft, and the main shaft is rotatably supported with respect to the pulley main body.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. A pulley rolling bearing can be provided. Also, since it is possible to suppress early peeling due to hydrogen embrittlement even under conditions in which slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine conversion, a long-life pulley rolling bearing is provided. Can do.

  Preferably, the rolling bearing further includes a car air conditioner electromagnetic clutch pulley and a pulley bearing support member disposed so as to face the inner peripheral surface of the car air conditioner electromagnetic clutch pulley, and the car air conditioner electromagnetic clutch pulley is used for the pulley. The bearing support member is rotatably supported.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. A rolling bearing for a car air conditioner electromagnetic clutch pulley can be provided. In addition, rolling bearings for car air conditioner electromagnetic clutch pulleys that have a long service life can be prevented because early peeling due to hydrogen embrittlement can be suppressed even under conditions in which slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine conversion. Can be provided.

  Preferably, the rolling bearing further includes a pulley shaft of the continuously variable transmission and a housing disposed so as to face the outer peripheral surface of the pulley shaft, and the pulley shaft is rotatably supported with respect to the housing.

  According to the rolling bearing of the present invention, since early peeling due to hydrogen embrittlement can be suppressed, a long service life can be obtained even under severe use conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. It is possible to provide a rolling bearing for a continuously variable transmission. In addition, since the groove curvature of the inner and outer rings of the bearing is set to be small in order to suppress the axial clearance of the bearing, it is possible to suppress early peeling due to hydrogen embrittlement even under conditions where differential sliding during bearing operation is large. A rolling bearing for a continuously variable transmission can be provided.

  In the above rolling bearing, preferably, the rolling bearing is a shell needle roller bearing. Shell-shaped needle roller bearings have a fast acceleration at the time of start-up (antilock) when they are used to support air compressors in automobiles that are rapidly accelerated or decelerated by switching electromagnetic clutches, especially under conditions involving sliding such as sudden acceleration / deceleration. When used to support a Brake System pump, when it is used at the large end of a connecting rod of a general-purpose engine, the rolling element is likely to slip, and early separation due to hydrogen embrittlement may occur.

  According to the rolling bearing of the present invention, since it is possible to suppress early separation due to hydrogen embrittlement even under such conditions, a long-life shell needle roller bearing can be provided.

  In the above rolling bearing, preferably, the rolling bearing is a solid needle roller bearing. Solid needle roller bearings support transmissions that accelerate quickly during start-up, especially when used to support air compressors in automobiles that accelerate and decelerate suddenly by switching electromagnetic clutches under conditions involving sudden acceleration and deceleration. In the case of being used for a large-sized connecting rod of a general-purpose engine, slippage between contact elements is likely to occur, and early peeling due to hydrogen embrittlement may occur.

  According to the rolling bearing of the present invention, since it is possible to suppress early separation due to hydrogen embrittlement even under such conditions, a solid needle roller bearing having a long life can be provided.

  In the above rolling bearing, preferably, the rolling bearing is a thrust needle roller bearing. The thrust needle roller bearing is constantly slipped from the rolling wheel during operation due to the difference in peripheral speed between the inside and outside of the rolling element, and may cause early separation due to hydrogen embrittlement. Thrust needle roller bearings may experience early peeling due to hydrogen embrittlement even under conditions involving slippage such as rapid acceleration and deceleration. According to the rolling bearing of the present invention, since it is possible to suppress early separation due to hydrogen embrittlement even under such conditions, a long-life thrust needle roller bearing can be provided.

  In the above rolling bearing, the rolling bearing preferably includes a cage. A needle roller bearing with a cage is a planetary pinion support bearing of CVT (Continuously Variable Transmission), particularly when used as an idler bearing for a vehicle transmission that accelerates quickly during acceleration, such as sudden acceleration / deceleration. When used as a bearing for a large end of a connecting rod of a two-wheeled engine or a general-purpose engine, the rolling element easily slips and may cause early peeling due to hydrogen embrittlement. According to the rolling bearing of the present invention, since it is possible to suppress early separation due to hydrogen embrittlement even under such conditions, a long-life needle roller bearing with a cage can be provided.

  As described above, according to the rolling bearing and the manufacturing method of the rolling bearing of the present invention, early separation due to hydrogen embrittlement can be suppressed.

It is a schematic sectional drawing which shows the structure of the motor provided with the rolling bearing in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the grease enclosure deep groove ball bearing as a rolling bearing for motors in one embodiment of this invention. It is the general | schematic fragmentary sectional view which expanded and showed the principal part of FIG. It is a figure which shows the outline of the manufacturing method of the rolling bearing in one embodiment of this invention. It is a figure for demonstrating the heat treatment process included in the manufacturing method of the rolling bearing in one embodiment of this invention. 1 is a schematic cross-sectional view showing a configuration around a spindle of a machine tool provided with a rolling bearing for a machine tool spindle in an embodiment of the present invention. It is a schematic sectional drawing which shows the structure of the angular ball bearing as a rolling bearing for machine tool main shafts in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the cylindrical roller bearing as a rolling bearing for machine tool main shafts in one embodiment of this invention. 1 is a schematic partial cross-sectional view of a lubricating device provided with a rolling bearing that lubricates with a small amount of lubricating oil as a rolling bearing for a machine tool spindle in an embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view of a lubrication apparatus including a rolling bearing that is lubricated with another small amount of lubricating oil as a rolling bearing for a machine tool main spindle according to an embodiment of the present invention. It is a schematic sectional drawing which shows the structure of the wheel provided with the rolling bearing for wheels in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the double row angular contact ball bearing as a rolling bearing for wheels in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the alternator provided with the rolling bearing for alternators in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the pulley provided with the rolling bearing for pulleys in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the compressor with a car air conditioner electromagnetic clutch pulley mechanism provided with the rolling bearing for car air conditioner electromagnetic clutch pulleys in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the continuously variable transmission provided with the rolling bearing for continuously variable transmission in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the shell type needle roller bearing in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the solid needle roller bearing in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the thrust needle roller bearing in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the needle roller bearing with a metal material holder | retainer in one embodiment of this invention. It is a schematic sectional drawing which shows the structure of the needle roller bearing with a polymeric material cage | basket in one embodiment of this invention. It is a figure which shows the relationship between the tempering temperature and the indentation depth in the indentation test of Example 1 of this invention. It is a figure which shows the relationship between the tempering temperature and HRC hardness in the HRC hardness test of Example 1 of this invention. It is a schematic diagram which shows the state by which the test piece in the surface nitridation concentration measuring test of Example 1 of this invention was embedded in resin. It is a figure which shows the relationship between the depth from the surface and nitrogen concentration in the surface nitridation concentration measurement test of Example 1 of this invention. It is a schematic side view which shows the taper-shaped outer ring | wheel test piece in the rolling fatigue test in the water-mixed oil of Example 1 of this invention. It is a schematic sectional drawing which shows the state which combined the inner ring | wheel of the angular ball bearing, and the steel ball with the taper-shaped outer ring | wheel test piece in the rolling fatigue test in the water-mixed oil of Example 1 of this invention. It is a figure which shows the relationship between the tempering temperature and the indentation depth in the indentation test of Example 2 of this invention. It is a figure which shows the relationship between the tempering temperature and HRC hardness in the HRC hardness test of Example 2 of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the structure of the motor provided with the rolling bearing in one embodiment of the present invention will be described.

  Referring to FIG. 1, a motor 90 according to an embodiment of the present invention has a disk-like shape, and includes a rotor 91 provided with a coil, and a frame (housing) 93 disposed so as to surround the rotor 91. And a main shaft 92 that is connected to a portion including the center (rotating shaft) of the rotor 91 and penetrates the frame 93 so as to be rotatable about the shaft integrally with the rotor 91. A grease-enclosed deep groove ball bearing 1 as a motor rolling bearing is fitted between the outer peripheral surface 92A of the main shaft 92 and a portion of the frame 93 that faces the outer peripheral surface 92A of the main shaft 92. That is, the grease-filled deep groove ball bearing 1 is a rolling bearing for a motor that rotatably supports a main shaft 92 of a motor 90 with respect to a frame 93 disposed so as to face the outer peripheral surface 92A of the main shaft 92.

  Furthermore, the motor 90 includes a stator 96 including a magnet fixedly arranged with respect to the frame 93 so as to face the outer peripheral surface of the rotor 91 inside the frame 93, and the main shaft as viewed from the rotor 91. 92 is connected to a portion opposite to the side protruding from the frame 93 and is commutator 94 configured to be rotatable integrally with the rotor 91 and fixed to the frame 93 so as to be in contact with the commutator 94. And a brush 95 arranged in the same manner.

Next, the grease filled deep groove ball bearing 1 will be described.
2 and 3, a grease-filled deep groove ball bearing 1 includes an outer ring 11 as a first race member, an inner ring 12 as a second race member, balls 13 as a plurality of rolling elements, and a cage. 14 and a seal member 15. An outer ring rolling surface 11 </ b> A as an annular first rolling surface is formed on the inner peripheral surface of the outer ring 11. On the outer peripheral surface of the inner ring 12, an inner ring rolling surface 12A as an annular second rolling surface facing the outer ring rolling surface 11A is formed. In addition, a plurality of balls 13 is formed with a ball rolling surface 13A (the surface of the ball 13) as a rolling element rolling surface. Then, the balls 13 are in contact with each of the outer ring rolling surface 11A and the inner ring rolling surface 12A at the ball rolling surface 13A, and are arranged at a predetermined pitch in the circumferential direction by the annular retainer 14, It is rotatably held on an annular track.

  The pair of seal members 15 are arranged so as to close the outer ring 11 and the inner ring 12 so as to close the space between the outer ring 11 and the inner ring 12, more specifically, the raceway space that is the space between the outer ring rolling surface 11A and the inner ring rolling surface 12A. Between the inner ring 12 and the inner ring 12, the outer ring 11 and the inner ring 12 are arranged at both ends in the width direction. With the above configuration, the outer ring 11 and the inner ring 12 of the grease-filled deep groove ball bearing 1 are rotatable relative to each other. Moreover, the grease composition 16 is enclosed in the orbital space.

  At least one bearing member among the outer ring 11 as the race member, the inner ring 12 and the ball 13 as the rolling element is made of JIS standard SUJ2. At least one bearing member among the outer ring 11, the inner ring 12 as the raceway member, and the ball 13 as the rolling element is quenched. At least one bearing member among the outer ring 11 as the race member, the inner ring 12 and the ball 13 as the rolling element has rolling surfaces 11A, 12A and 13A that are nitrided. The region NR subjected to nitriding treatment is formed from the outer ring 11, the inner ring 12 and the balls 13 as rolling elements toward the inside. In the following drawings, the nitrided region NR is not shown, but is similarly formed from the surface of the outer ring 11, the inner ring 12 and the balls 13 as rolling elements to the inside.

  A steel ball for SUJ2 standard rolling bearing with a diameter of 19.05 mm is pressed with a load of 3.18 kN to at least one bearing member among the outer ring 11, the inner ring 12 as a race member, and the ball 13 as a rolling element, and held for 10 seconds. The depth of the impression formed on the bearing member by unloading is 0.2 μm or less. The Rockwell C scale hardness of the rolling surface of the bearing member is HRC61.2 or more and HRC63.3 or less.

  Further, the surface nitriding concentration of the rolling surfaces 11A, 12A, and 13A of at least one bearing member among the outer ring 11 and the inner ring 12 as the race members and the balls 13 as the rolling elements is 0.05% by mass or more and 0.4% by mass. It is as follows.

  Moreover, the ball | bowl 13 as a rolling element may select JIS specification SUJ2 which is not nitrided. In this case, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm is pressed against the ball 13 with a load of 1.97 kN, held for 10 seconds, and then unloaded, so that the depth of indentation formed on the bearing member is 0.00. It is 2 μm or less.

  Moreover, the Rockwell C scale hardness of the whole rolling element is HRC57.0 or more and HRC58.9 or less.

  Moreover, it is preferable that the ball | bowl 13 as a rolling element consists of a material containing ceramics. As the ceramic, silicon nitride, sialon, or the like can be applied.

  When the ceramic is a sintered body mainly composed of β sialon, which is one of sialon, it is sintered under a pressure of low pressure (for example, 1 MPa or less), so pressure sintering is performed under a pressure of 10 MPa or more. It can be manufactured at a lower cost than a sintered body mainly composed of silicon nitride.

A sintered body containing β sialon as a main component is a sintered body in which β sialon is a main component and the balance is made of impurities. β sialon is represented by a composition formula of Si _6-Z AL _Z N _8-Z and is configured so that Z satisfies a range of 0.1 ≦ Z ≦ 3.5. Impurities include those derived from raw materials or mixed in the manufacturing process, and also include inevitable impurities. As the sintering aid, at least one of magnesium (Mg), aluminum (Al), silicon (Si), titanium (Ti), rare earth element oxide, nitride, and oxynitride may be employed. it can. The sintering aid is preferably 20% by mass or less in the sintered body.

  Moreover, it is preferable that the holder | retainer 14 for hold | maintaining the ball | bowl 13 as a rolling element consists of a material containing a metal.

  Next, the operation of the motor 90 will be described. With reference to FIG. 1, a current supplied to a brush 95 from a power source (not shown) via a wire flows through a coil of the rotor 91 via a commutator 94. At this time, the rotor 91 rotates about the axis of the main shaft 92 with respect to the frame 93 by an electromagnetic force generated by a current flowing through the coil of the rotor 91 and a magnetic field formed by the stator 96 including a magnet. Further, when the rotor 91 rotates by a predetermined angle, the direction of the current flowing through the coil of the rotor 91 is reversed by the action of the commutator 94 and the brush 95, and the rotor 91 further rotates. By repeating this, the rotor 91 continuously rotates with respect to the housing, and the rotation is taken out by the main shaft 92.

  Next, the manufacturing method of the rolling bearing for motors in one embodiment of this invention is demonstrated.

  Referring to FIG. 4, first, in a step (S100), a steel material preparation step for preparing a steel material composed of JIS standard SUJ2 is performed. Specifically, for example, steel bars or steel wires composed of JIS standard SUJ2 are prepared.

  Next, in a process (S200), the shaping | molding process which produces the steel member shape | molded by the schematic shape of the bearing member of the rolling bearing for motors by shape | molding the said steel material is implemented. Specifically, for example, forging, turning, and the like are performed on the above-described steel bars and steel wires, and the outer ring 11, the inner ring 12, the balls 13, and the like shown in FIGS. A steel member is produced. The said process (S100) and (S200) comprise the steel member preparation process in which the steel member shape | molded by the schematic shape of the bearing member of the rolling bearing for motors is prepared.

  Next, in the step (S300), the steel member is cooled from a temperature of A1 point or higher to a temperature of MS point or lower, whereby a quench hardening step is performed in which the steel member is hardened and hardened. Is done. Thereafter, in the step (S400), a tempering step is performed in which the quench-hardened steel member is heated to a temperature range of 240 ° C. or higher and 300 ° C. or lower and tempered. The steps (S300) and (S400) constitute a heat treatment step in which the steel member is heat treated. Details of this heat treatment step will be described later.

  Next, in step (S500), a finishing step is performed. Specifically, the outer ring 11, the inner ring 12, the ball 13 and the like are finished by performing a finishing process such as a grinding process on the steel member that has been subjected to the heat treatment process. Thereby, the manufacturing method of the bearing member of the rolling bearing for motor in one embodiment of the present invention is completed, and the outer ring 11, the inner ring 12, the ball 13 and the like as the bearing member of the rolling bearing for motor are completed.

  Further, in the process (S600), an assembly process is performed. Specifically, the outer ring 11, the inner ring 12, and the ball 13 produced in steps (S100) to (S500) are combined with a separately prepared cage 14, and the motor according to the embodiment of the present invention. A grease-filled deep groove ball bearing 1 as a rolling bearing for use is assembled. Thereby, the manufacturing method of the rolling bearing for motors in one embodiment of the present invention is completed, and the grease-enclosed deep groove ball bearing 1 as the rolling bearing for motors is completed.

  Next, details of the heat treatment step will be described. In FIG. 5, the horizontal direction indicates time, and the time elapses toward the right. In FIG. 5, the vertical direction indicates the temperature, and the higher the temperature, the higher the temperature.

  Referring to FIG. 5, the steel member produced in the step (S200) is first heated to a temperature T1 that is a temperature equal to or higher than the A1 point, and is held for a time t1. At this time, the steel member is heated in an atmosphere in which ammonia gas is added to RX gas, for example. Thereby, the nitriding treatment is performed on the surface of the steel member which becomes the rolling surface of the bearing member. Thereafter, the steel member is immersed in oil (oil cooling), for example, to be cooled from a temperature not lower than the A1 point to a temperature not higher than the MS point, and quenching is completed. The quench hardening process is completed by the above procedure.

  Furthermore, after the quench-hardened steel member is heated to a temperature T2 that is a temperature of A1 or lower and held for t2, the tempering step is performed by, for example, air cooling (cooling) to room temperature. . Through the above steps, the heat treatment step in one embodiment of the present invention is completed.

  Here, the temperature T1 is, for example, a temperature of 850 ° C. On the other hand, the time t1 is, for example, 180 minutes.

  Moreover, temperature T2 is a temperature of 240 degreeC or more and 300 degrees C or less, for example. On the other hand, the time t2 is 120 minutes, for example.

  Here, the A1 point indicates a point corresponding to a temperature at which the steel structure starts transformation from ferrite to austenite when the steel is heated. Moreover, MS point shows the point corresponded to the temperature which the structure | tissue of steel starts a transformation to a martensite when austenitized steel is cooled.

  In the method for manufacturing a bearing member of a rolling bearing for a motor according to an embodiment of the present invention, a steel member made of JIS standard SUJ2 is prepared in the steel member preparation step in view of the cost and procurement of the material. In the quench hardening process, after quenching in an atmosphere in which ammonia gas is added to RX gas at a temperature of 850 ° C. as a nitriding process, the steel member is 240 ° C. or more and 300 ° C. or less in the tempering process. And tempering is performed. As a result, according to the manufacturing method of the bearing member of the rolling bearing for motor according to the above-described embodiment of the present invention, the steel constituting the bearing member of the rolling bearing for motor is less likely to be plastically deformed and generates atomic vacancies. Can be difficult.

  In consideration of productivity, the rolling element may be made of JIS standard SUJ2 which is not nitrided. Then, the manufacturing method of the rolling bearing for motors which has a rolling element which consists of JIS standard SUJ2 which is not nitrided is demonstrated.

  Referring to FIG. 4, first, in a step (S100), a steel material preparation step for preparing a steel material composed of JIS standard SUJ2 is performed. Specifically, for example, steel bars or steel wires composed of JIS standard SUJ2 are prepared.

  Next, in a process (S200), the shaping | molding process which produces the steel member shape | molded by the rough shape of the rolling element of the rolling bearing for motors by shape | molding the said steel material is implemented. Specifically, for example, a steel member formed into the general shape of the ball 13 shown in FIGS. 2 and 3 is produced by performing processing such as forging and turning on the above steel bars and steel wires. Is done. The said process (S100) and (S200) comprise the steel member preparation process in which the steel member shape | molded by the schematic shape of the bearing member of the rolling bearing for motors is prepared.

  Next, in the step (S300), the steel member is cooled from a temperature of A1 point or higher to a temperature of MS point or lower, whereby a quench hardening step is performed in which the steel member is hardened and hardened. Is done. Thereafter, in the step (S400), a tempering step is performed in which the quench-hardened steel member is heated to a temperature range of 240 ° C. or higher and 280 ° C. or lower and tempered. The steps (S300) and (S400) constitute a heat treatment step in which the steel member is heat treated. Details of this heat treatment step will be described later.

  Next, in step (S500), a finishing step is performed. Specifically, the ball 13 is finished by performing a finishing process such as a grinding process on the steel member subjected to the heat treatment process. Thereby, the ball 13 of the rolling bearing for a motor in one embodiment of the present invention is completed.

  Further, in the process (S600), an assembly process is performed. Specifically, the ball 13 produced in steps (S100) to (S500) and the separately prepared outer ring 11, inner ring 12, cage 14 and the like are combined to provide a motor according to an embodiment of the present invention. A grease-filled deep groove ball bearing 1 as a rolling bearing for use is assembled. Thereby, the manufacturing method of the rolling bearing for a motor which has the rolling element which consists of JIS standard SUJ2 which is not nitrided in one embodiment of this invention is completed, and the grease-filled deep groove ball bearing 1 as a rolling bearing for motors is completed. To do.

  Next, details of the heat treatment step will be described. In FIG. 5, the horizontal direction indicates time, and the time elapses toward the right. In FIG. 5, the vertical direction indicates the temperature, and the higher the temperature, the higher the temperature.

  Referring to FIG. 5, the steel member produced in the step (S200) is first heated to a temperature T1 that is a temperature equal to or higher than the A1 point, and is held for a time t1. At this time, the steel member is heated, for example, in an RX gas atmosphere. Thereafter, the steel member is immersed, for example, in oil (oil cooling), so that the steel member is cooled from the temperature of the A1 point or higher to the temperature of the MS point or lower to complete the quenching. The quench hardening process is completed by the above procedure.

  Furthermore, after the quench-hardened steel member is heated to a temperature T2 that is a temperature of A1 or lower and held for t2, the tempering step is performed by, for example, air cooling (cooling) to room temperature. . Through the above steps, the heat treatment step in one embodiment of the present invention is completed.

  Here, the temperature T1 is, for example, a temperature of 850 ° C. On the other hand, the time t1 is, for example, 80 minutes.

  The temperature T2 is, for example, a temperature of 240 ° C. or higher and 280 ° C. or lower. On the other hand, the time t2 is 120 minutes, for example.

  In the above description, the grease deep groove ball bearing has been described as an example of the rolling bearing according to the embodiment of the present invention. Moreover, the motor was demonstrated as an example of the apparatus with which the rolling bearing of one embodiment of this invention is applied. The rolling bearing according to an embodiment of the present invention is not limited to the above, and may be an angular ball bearing, a cylindrical roller bearing, or the like. Moreover, the rolling bearing of one embodiment of the present invention may be applied to a rolling bearing for a machine tool main shaft. Hereinafter, an angular ball bearing and a cylindrical roller bearing will be described as another example of the rolling bearing according to the embodiment of the present invention, and the configuration of a machine tool including these will be described.

  Referring to FIG. 6, machine tool 100 according to an embodiment of the present invention includes a main shaft 101 having a cylindrical shape, a housing 102 surrounding the outer peripheral surface of main shaft 101, and an outer peripheral surface of an outer ring being an inner wall 102A of the housing. And an angular contact ball bearing 10 as a rolling bearing for a machine tool main shaft disposed so as to be fitted between the main shaft 101 and the housing 102 so that the inner peripheral surface of the inner ring contacts the outer peripheral surface 101A of the main shaft 101. (Front bearing) and cylindrical roller bearing 20 (rear bearing). Thus, the main shaft 101 is supported so as to be rotatable about the axis with respect to the housing 102.

  A motor rotor 103B is installed on the main shaft 101 so as to surround a part of the outer peripheral surface 101A, and a motor stator 103A is installed on the inner wall 102A of the housing 102 at a position facing the motor rotor 103B. The motor stator 103A and the motor rotor 103B constitute a motor 103 (built-in motor). As a result, the main shaft 101 can rotate relative to the housing 102 by the power of the motor 103.

  That is, the angular ball bearing 10 and the cylindrical roller bearing 20 are members that are disposed adjacent to the main shaft 101 in the machine tool 100 that processes a workpiece by rotating the main shaft 101. It is a rolling bearing for a machine tool main shaft that is rotatably supported with respect to a certain housing 102.

Next, the angular ball bearing 10 will be described.
Referring to FIG. 7, an angular ball bearing 10 includes an outer ring 11 as a first race member that is a bearing member of a rolling bearing for a machine tool spindle, an inner ring 12 as a second race member, and a plurality of rolling elements. A ball 13 and a cage 14 are provided. The outer ring 11 is formed with an outer ring rolling surface 11A as an annular first rolling surface. The inner ring 12 is formed with an inner ring rolling surface 12A as an annular second rolling surface facing the outer ring rolling surface 11A. In addition, a plurality of balls 13 is formed with a ball rolling surface 13A (the surface of the ball 13) as a rolling element rolling surface. The balls 13 are in contact with each of the outer ring rolling surface 11A and the inner ring rolling surface 12A at the ball rolling surface 13A, and are arranged at a predetermined pitch in the circumferential direction by an annular retainer 14. It is rotatably held on an annular track. Thereby, the outer ring | wheel 11 and the inner ring | wheel 12 can rotate relatively mutually.

  Here, in the angular ball bearing 10, the straight line connecting the contact point between the ball 13 and the outer ring 11 and the contact point between the ball 13 and the inner ring 12 is a radial direction (a direction perpendicular to the rotation axis of the angular ball bearing 10). ). Therefore, when a radial load is applied, a component force is generated in the axial direction (the direction of the rotation axis of the angular ball bearing 10). Referring to FIG. 6, in machine tool 100 according to one embodiment of the present invention, two angular ball bearings 10 in the same direction are arranged on the front side (tip 101B side of main shaft 101), and the rear side (motor rotor 103B). On the side), two angular ball bearings 10 opposite to the front side are arranged to cancel the component force.

Next, the cylindrical roller bearing 20 will be described.
Referring to FIG. 8, the cylindrical roller bearing 20 basically has the same configuration as the angular ball bearing 10 described above, and has the same effect. However, the cylindrical roller bearing 20 is different from the angular ball bearing 10 in the configuration of the raceway member and the rolling element.

  That is, the cylindrical roller bearing 20 includes an outer ring 11 as a first race member which is a bearing member of a rolling bearing for a machine tool main shaft, an inner ring 12 as a second race member, and cylindrical rollers 23 as a plurality of rolling elements, And a cage 14. The outer ring 11 is formed with an outer ring rolling surface 11A as an annular first rolling surface. The inner ring 12 is formed with an inner ring rolling surface 12A as an annular second rolling surface facing the outer ring rolling surface 11A. Further, the plurality of cylindrical rollers 23 are formed with roller rolling surfaces 23 </ b> A (outer peripheral surfaces of the cylindrical rollers 23) as rolling element rolling surfaces. The cylindrical roller 23 is in contact with each of the outer ring rolling surface 11A and the inner ring rolling surface 12A at the roller rolling surface 23A, and is arranged at a predetermined pitch in the circumferential direction by the annular retainer 14. It is rotatably held on an annular track. Thereby, the outer ring | wheel 11 and the inner ring | wheel 12 can rotate relatively mutually.

  Next, the operation of the machine tool 100 will be described. Referring to FIG. 6, when power is supplied from a power source (not shown) to motor stator 103A of motor 103, a driving force for rotating motor rotor 103B around the axis is generated. Thus, the main shaft 101 rotatably supported by the angular ball bearing 10 and the cylindrical roller bearing 20 with respect to the housing 102 rotates relative to the housing 102 together with the motor rotor 103B. Thus, by rotating the main shaft 101, a tool (not shown) attached to the tip 101B of the main shaft 101 can cut and grind the workpiece to process the workpiece.

  The manufacturing method of the rolling bearing for machine tool spindles according to the embodiment of the present invention is the same as the manufacturing method of the rolling bearing for motor, except for the molding step. In the forming step, steel members formed into a schematic shape such as the outer ring 11, the inner ring 12, the balls 13, and the cylindrical rollers 13 shown in FIGS. 7 and 8 are produced. The description of other manufacturing methods will not be repeated.

  Next, a lubrication apparatus including a rolling bearing that is lubricated with a small amount of lubricating oil as another example of the rolling bearing for a machine tool spindle according to an embodiment of the present invention will be described.

  The same elements as those of the above-described embodiment of the present invention are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIG. 9, the lubricating device 40 mainly includes an angular ball bearing 30, a lubricating oil introducing member 31, a lid member 32, and an inner ring spacer 33. For the sake of clarity, FIG. 9 shows the periphery of the portion where the lubricating oil is introduced, and the main shaft, housing, etc. to which the lubricating device 40 is applied are not shown.

  The inner ring 12 of the angular ball bearing 30 has an oil receiving circumferential groove 34 that receives the lubricating oil discharged from the lubricating oil introducing member 31. The oil receiving circumferential groove 34 is provided on an end surface adjacent to the lubricating oil introducing member 31. On the outer diameter surface of the inner ring 12, a slope portion 12B having a large diameter on the inner ring rolling surface 12A side is formed. The slope portion 12B is formed so as to guide the lubricating oil accumulated in the oil receiving circumferential groove 34 to the inner ring rolling surface 12A of the inner ring 12 by centrifugal force and surface tension acting on the lubricating oil.

  The lubricating oil introduction member 31 has a hook-shaped portion 31 a extending in the axial direction from the side surface toward the angular ball bearing 30. A seal portion 31b is formed at the tip of the bowl-shaped portion 31a. The seal portion 31 b is disposed in the vicinity of the ball 13 between the inner diameter surface of the cage 14 and the inner ring 12. The seal portion 31 b is formed on an inclined surface having an inner diameter surface of the same angle α as the inclined surface portion 12 </ b> B of the inner ring 12. The seal portion 31b is disposed on the slope portion 12B of the inner ring 12 with a gap δ. The lubricating oil introduction member 31 has a lubricating oil supply path 31c and a discharge port 31d. The lubricating oil supply path 31c and the discharge port 31d communicate with each other. The discharge port 31 d is opened facing the oil receiving circumferential groove 34 of the inner ring 12.

  An oil draining circumferential groove 31e that opens toward the inner diameter side is formed in a portion of the lubricating oil introducing member 31 that is closer to the base end than the seal portion 31b of the flange portion 31a. The drain oil circumferential groove 31e communicates with a drain oil recovery path (not shown). The waste oil is collected through the waste oil recovery path.

  In the lubricating device 40, a very small amount of the oil discharged from the discharge port 31 d of the lubricating oil introducing member 31 is used as the lubricating oil for the angular ball bearing 30, and the majority is used for cooling the inner ring 12. A very small amount of the oil discharged to the oil receiving circumferential groove 34 of the inner ring 12 is introduced into the angular ball bearing 30 along the inclined surface portion 12 </ b> B by centrifugal force and surface tension of the oil accompanying the rotation of the inner ring 12. Used as a lubricating oil.

As this lubricating oil, for example, a very low viscosity lubricating oil equivalent to ISO VG2 is used.
The manufacturing method of the rolling bearing lubricated with this small amount of lubricating oil is the same as the manufacturing method of the rolling bearing for motor, except for the molding step. In the forming step, steel members formed into a schematic shape such as the outer ring 11, the inner ring 12, and the ball 13 shown in FIG. 9 are produced. The description of other manufacturing methods will not be repeated.

  In the lubricating device 40, since the oil amount is reduced and the lubricating oil having a lower viscosity is used, a reduction in torque can be achieved.

Furthermore, a lubrication apparatus including a rolling bearing that is lubricated with another small amount of lubricating oil will be described.
The same elements as those of the above-described embodiment of the present invention are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIG. 10, this lubrication device 60 mainly has an angular ball bearing 50, a spacer 61, and a grease reservoir forming member 62. In FIG. 10, for the sake of clarity, the periphery of the portion where the lubricating oil is introduced is illustrated, and the main shaft, the housing, and the like to which the lubricating device 60 is applied are not illustrated.

  On the outer ring 11 of the angular ball bearing 50, a step surface 11 b is provided so as to extend to the outer diameter side of the outer ring 11 away from the ball 13.

  The grease pool forming member 62 is a ring-shaped member having a grease pool portion 63 for storing grease therein.

  An internal space sandwiched between the spacer 61 and the grease reservoir forming member 62 constitutes a grease reservoir portion 63. The grease pool forming member 62 seals the spacer 61 with the outer side of the side wall portion of the grease pool forming member 62 and the inner side of the side wall portion of the spacer 61 after the grease is sealed in the grease pool portion 63. It is positioned in the axial direction of a main shaft (not shown).

  A sealing material (not shown) is interposed between the spacer 61 and the grease reservoir forming member 62. This sealing material prevents grease leakage.

  The tip 62 a of the grease reservoir forming member 62 is disposed along the inner diameter surface of the outer ring 11. The distal end of the distal end portion 62a is arranged to face the step surface 11b. A flow path 64 and a gap 65 are formed between the distal end portion 62 a and the outer ring 11.

  A flow path 64 is formed by the peripheral wall of the tip end portion 62a and the inner diameter surface portion of the outer ring 11 facing the tip end portion 62a. A gap 65 having a small gap amount Δ is formed in the axial direction of the main shaft (not shown) by the end surface of the tip end portion 62a and the step surface 11b facing the tip portion 62a. The gap 65 communicates with the flow path 64 and opens at the edge of the outer ring rolling surface. The gap amount Δ of the gap 65 is, for example, 0.05 to 0.1 mm.

  The inner diameter surface following the end surface of the tip end portion 62 a has a tapered surface 66 close to the ball 13, and is configured so that lubricating oil can easily accumulate between the tapered surface 66 and the ball 13. The distance between the taper surface 66 and the ball 13 is preferably a minimum gap that is large enough to allow the oil adhering to the taper surface 66 to be transferred to the surface of the ball 13, for example, 0.2 mm or less.

  The manufacturing method of the rolling bearing lubricated with the other small amount of lubricating oil is the same as the manufacturing method of the rolling bearing for motor, except for the molding step. In the forming step, steel members formed into a schematic shape such as the outer ring 11, the inner ring 12, and the ball 13 shown in FIG. 10 are produced. The description of other manufacturing methods will not be repeated.

  In the lubrication device 60, a small amount of base oil is introduced into the angular ball bearing 50 from the grease reservoir 63 using the capillary phenomenon. In this method, no torque is generated by stirring the grease thickener with the retainer 14 or the like, so that low heat is generated and high speed operation is possible.

  Moreover, the rolling bearing of one embodiment of the present invention may be applied to a wheel rolling bearing. Hereinafter, a wheel rolling bearing will be described as another example of the rolling bearing according to the embodiment of the present invention, and the configuration of the wheel provided with the same will be described.

  Referring to FIGS. 11 and 12, a double-row angular contact ball bearing 110, which is a rolling bearing for a wheel, includes a rotation side member such as a hub wheel 113 that supports a wheel 120 (drive wheel) including a wheel 111 and a tire 112. It supports so that it can rotate with respect to fixed side members, such as the knuckle 114. FIG.

  This double-row angular ball bearing 110 mainly includes an outer ring 11, an inner ring 12, a ball 13, a cage 14, a seal member 15, and a magnetic encoder 115. The inner ring 12 is fitted to the outer circumferential surface of the hub wheel 113, and the outer ring 11 is fitted to the inner circumferential surface of the knuckle 114.

  The outer ring 11 is composed of one member. The inner ring 12 is composed of two members. The plurality of balls 13 are arranged in a double row. The plurality of balls 13 come into contact with each of the outer ring rolling surface 11A and the inner ring rolling surface 12A at the ball rolling surface 13A, and are arranged at a predetermined pitch in the circumferential direction by a comb-shaped cage 14. It is rotatably held on an annular track. Thereby, the outer ring | wheel 11 and the inner ring | wheel 12 can rotate relatively mutually.

  A straight line connecting the contact point between the ball 13 and the outer ring 11 and the contact point between the ball 13 and the inner ring 12 forms an angle with respect to the radial direction (the direction perpendicular to the rotation axis of the double-row angular ball bearing 110). Yes. Therefore, when a radial load is applied, a component force is generated in the axial direction (the direction of the rotation axis of the double-row angular ball bearing 110). The straight line connecting the contact point between the ball 13 and the outer ring 11 of the adjacent ball 13 and the contact point between the ball 13 and the inner ring 12 is arranged in the reverse direction so as to cancel the component force.

  Seal members 15 are inserted into the inner diameter of the outer ring 11 and the outer diameter of the inner ring 12. This seal member 15 can prevent oil leakage from inside the double row angular ball bearing and entry of foreign matter and moisture from outside the double row angular ball bearing.

  The magnetic encoder 115 is press-fitted into the outer diameter of the end of the inner ring 12, and a magnetic member that is multipolarly magnetized in the circumferential direction in this state is in close proximity to the magnetic sensor 116 that is fixed to the knuckle 114. Thereby, the rotational speed of the wheel can be detected with high accuracy.

  Next, the operation of the wheel 120 will be described. The wheel 120 is rotated by the rotation of the rotating side member such as the hub wheel 113 with respect to the fixed side member such as the knuckle 114.

  The method for manufacturing a wheel rolling bearing according to an embodiment of the present invention is the same as the method for manufacturing the rolling bearing for motor, except for the molding step. In the forming step, steel members formed into a schematic shape such as the outer ring 11, the inner ring 12, and the balls 13 shown in FIG. 12 are produced. The description of other manufacturing methods will not be repeated.

  In the embodiment of the present invention described above, as an example, a rolling bearing for a motor, a rolling bearing for a machine tool spindle, a rolling bearing for a wheel, a grease deep groove ball bearing, an angular contact ball bearing, a cylindrical roller bearing, a double row angular contact ball The bearings and the race members and rolling elements included in the bearings have been described. The rolling bearing and the bearing member thereof according to the present invention are not limited to these, and may be other forms of rolling bearings, raceway members and rolling elements included therein. For example, the rolling bearing of another form may be a radial bearing or a thrust bearing. The track member includes an outer ring and an inner ring. Moreover, the rolling element may form a rolling surface between the inner ring, the outer ring, and the bearing disc. The rolling elements include balls, cylindrical rollers, tapered rollers and the like.

  Although the JIS standard SUJ2 has been described as the material for the outer ring, the inner ring and the rolling element as the race member, 52100 (AISI or SAE standard), 100Cr6 (DIN standard), and GCr15, which are equivalent to the JIS standard SUJ2. (GSB standard) can also be applied.

Furthermore, another example of the embodiment of the present invention will be described.
The rolling bearing according to one embodiment of the present invention may be applied to an alternator rolling bearing. Hereinafter, an alternator rolling bearing will be described as another example of the rolling bearing according to the embodiment of the present invention, and the configuration of the alternator including the same will be described.

  Referring to FIG. 13, an alternator 200 according to an embodiment of the present invention includes a shaft (main shaft) 201, a rotor 202, a stator 203, a pulley 204, a housing 205, and grease filled as a rolling bearing for an alternator. It mainly has a deep groove ball bearing 1.

  A housing 205 is disposed so as to surround the rotor 202. A shaft 201 is disposed so as to penetrate the central portion of the rotor 202 and penetrate the wall surface of the housing 205. A stator 203 is disposed inside the housing 205 so as to face the outer peripheral surface of the rotor 202.

  A housing 205 is disposed so as to face a part of the outer peripheral surface of one end of the shaft 201. Between the shaft 201 and the housing 205, a grease-filled deep groove ball bearing 1 that is a rolling bearing for an alternator is disposed. A shaft 201 is rotatably supported with respect to the housing 205 by the grease-filled deep groove ball bearing 1. A pulley 204 having an annular shape is attached to the tip of one end of the shaft 201 outside the housing 205. On the outer peripheral surface of the pulley 204, there is provided an engagement groove 206 on which a transmission belt (not shown) is hung.

  The grease-enclosed deep groove ball bearing 1 that is this alternator rolling bearing has the same configuration as the grease-enclosed deep groove ball bearing 1 as the motor rolling bearing in the embodiment of the present invention.

  A grease-filled deep groove ball bearing 1 that is a rolling bearing for an alternator is disposed adjacent to a shaft 201 that is rotated by this power in an alternator 200 that operates using power generated by a power source such as an engine (not shown). For example, it is a rolling bearing for electrical equipment / auxiliary equipment for automobiles that is rotatably supported with respect to the housing 205.

  In general, the grease-filled deep groove ball bearing 1 disposed at one end of the shaft 201 between the rotor 202 and the pulley 204 is called a front bearing. The grease-filled deep groove ball bearing 1 disposed at the other end of the shaft 201 is called a rear bearing. The grease-filled deep groove ball bearing 1 of the front bearing having a large stress such as a bending moment is more likely to cause hydrogen embrittlement separation than the grease-filled deep groove ball bearing 1 of the rear bearing.

  Next, the operation of the alternator 200 will be described. A transmission belt (not shown) that rotates by power from a power source such as an engine (not shown) is hung on the outer peripheral surface of the pulley 204 in which the engagement groove 206 is formed. As the transmission belt rotates, the pulley 204 rotates around the axis of the shaft 201 together with the shaft 201 pivotally supported by the grease-filled deep groove ball bearing 1 with respect to the housing 205. The rotor 202 rotates around the axis of the shaft 201 integrally with the shaft 201. At this time, the rotor 202 rotates relative to the stator 203 that faces the outer peripheral surface of the rotor 202 and is fixed to the housing 205. As a result, an electromotive force is generated in the coil of the stator 203 due to electromagnetic induction between the rotor 202 and the stator 203.

  The manufacturing method of the grease-enclosed deep groove ball bearing 1 as the alternator rolling bearing is the same as the manufacturing method of the grease-enclosed deep groove ball bearing 1 as the motor rolling bearing in the embodiment of the present invention.

  Alternator rolling bearings are prone to early peeling due to hydrogen embrittlement due to the effect of slippage between contact elements under rapid acceleration / deceleration conditions. In addition, early peeling due to hydrogen embrittlement may occur due to the influence of electricity. Further, with recent space savings, belts for driving electrical accessory parts including alternators have been made serpentine. Here, serpentine formation means that a plurality of accessory parts are driven by a single belt. By using serpentine, a separate belt is not required for each accessory part, so that space can be saved. With serpentine formation, the load tends to increase and the load fluctuation tends to increase, so that slip is more likely to be induced than in the prior art.

  Since the grease-filled deep groove ball bearing 1 that is a rolling bearing for an alternator is used for inner ring rotation, a part of load rotation of the outer ring 11 is large. Therefore, early peeling due to hydrogen embrittlement is likely to occur in a part of the outer ring 11, and the bearing member according to the embodiment of the present invention is preferably applied to the outer ring 11.

  Moreover, the rolling bearing of one embodiment of the present invention may be applied to a pulley rolling bearing. Hereinafter, a pulley rolling bearing will be described as another example of a rolling bearing according to an embodiment of the present invention, and a configuration of a pulley including the same will be described.

  Referring to FIG. 14, a pulley 210 according to an embodiment of the present invention mainly has a pulley body 211 and a grease-filled deep groove ball bearing 1 that is a pulley rolling bearing.

  The pulley body 211 has an annular shape. On the outer peripheral surface of the pulley body 211, a transmission belt wrapping portion 212 on which a transmission belt (not shown) is laid is provided. A through hole 213 through which the shaft (main shaft) 218 passes is formed in the central portion on the inner diameter side of the pulley body 211. The grease-enclosed deep groove ball bearing 1 is fitted into the pulley body 211 so that the inner peripheral surface of the through hole 213 and the outer ring 11 of the grease-enclosed deep groove ball bearing 1 are in contact with each other.

  More specifically, the pulley body 211 includes a cylindrical inner peripheral cylindrical portion 214 having a through hole on the inner peripheral surface, and a radially outer side from one end portion in the width direction (axial direction) of the inner peripheral cylindrical portion 214. A flange portion 215 extending in the width direction, an outer peripheral cylindrical portion 216 extending in the width direction (axial direction) from the flange portion 215, and a flange portion extending radially inward from the other end portion in the width direction (axial direction) of the inner peripheral cylindrical portion 214 217. The outer ring 11 of the grease-filled deep groove ball bearing 1 is fitted so as to contact the inner peripheral cylindrical portion 214 and the flange portion 217 of the pulley body 211.

  Further, a shaft 218 is fitted into the inner ring 12 of the grease-filled deep groove ball bearing 1 by being fitted.

  The grease-enclosed deep groove ball bearing 1 as the pulley rolling bearing has the same configuration as the grease-enclosed deep groove ball bearing 1 as the motor rolling bearing in the embodiment of the present invention.

  The grease-enclosed deep groove ball bearing 1 that is a rolling bearing for a pulley is a pulley 210 that operates by using power generated by a power source such as an engine (not shown). The pulley body 211 that is rotationally driven by this power passes through the pulley 210. For example, it is a rolling bearing for electrical equipment / auxiliary equipment for automobiles that is rotatably supported with respect to the shaft 218 arranged in this manner.

  Next, the operation of the pulley 210 will be described. A transmission belt (not shown) that rotates with power from a power source (not shown) such as an engine (not shown) is hung on the outer peripheral surface of the pulley body 211 in which the transmission belt hooking portion 212 is formed. As the transmission belt rotates, the pulley 210 rotates around the shaft 218 integrally with the shaft 218 supported by the grease-filled deep groove ball bearing 1. Thus, the pulley 210 can function as a tensioner that applies tension to the transmission belt when the distance between the shafts on which the transmission belt is hung is fixed. Accordingly, the pulley 210 can serve as an idler for changing the traveling direction of the transmission belt for the purpose of avoiding contact with various devices without an engine room that becomes an obstacle.

  The manufacturing method of the grease-enclosed deep groove ball bearing 1 as the pulley rolling bearing is the same as the manufacturing method of the grease-enclosed deep groove ball bearing 1 as the motor rolling bearing in the embodiment of the present invention.

  Rolling bearings for pulleys may be separated at an early stage due to hydrogen embrittlement, especially due to the effects of sliding and energization. In addition, with recent space savings, belts for driving electrical accessory parts including pulleys have been made serpentine. The load load tends to increase and the load fluctuation tends to increase, and slipping is more easily induced by serpentine formation.

  Since the grease-enclosed deep groove ball bearing 1 that is a rolling bearing for pulleys is used for outer ring rotation, a part of the inner ring 12 rotates a lot. Therefore, early peeling due to hydrogen embrittlement is likely to occur in a part of the inner ring 12, and it is preferable that the bearing member according to the embodiment of the present invention is applied to the inner ring 12.

  Moreover, the rolling bearing of one embodiment of the present invention may be applied to a rolling bearing for a car air conditioner electromagnetic clutch pulley. Hereinafter, a rolling bearing for a car air conditioner electromagnetic clutch pulley will be described as another example of a rolling bearing according to an embodiment of the present invention, and the configuration of a compressor with a car air conditioner electromagnetic clutch pulley mechanism including the same will be described.

  Referring to FIG. 15, the compressor includes a swash plate type swash plate compressor 220 and a compressor pulley mechanism 230.

First, the swash plate type swash plate compressor 220 will be described.
A swash plate type swash plate compressor 220 includes a housing 221, a pulley bearing support member 234 fixed to the housing 221 by, for example, a screw, a main shaft 223, a rotating member 225 attached to the main shaft 223, and The swash plate 222 oscillates with the rotation of the rotary member 225, a piston rod 226 connected to the swash plate 222, and a piston 224 connected to the opposite side of the piston rod 226. .

  Between the rotary member 225 and the pulley bearing support member 234, a rotary member / pulley support member bearing 231 formed of a double row thrust needle roller bearing is disposed as a support structure for receiving a thrust load. Between the swash plate 222 and the rotating member 225, a swash plate support bearing 233 composed of a double row thrust needle roller bearing is disposed as a support structure for receiving a thrust load.

  In the compressor 220, the rotating member 225 rotates with the rotation of the main shaft 223, whereby the swash plate 222 swings. The swing movement of the swash plate 222 causes the piston rod 226 to reciprocate, and the piston 224 connected to the piston rod 226 reciprocates within the cylinder.

Next, the compressor pulley mechanism 230 will be described.
A pulley bearing support member 234 is fixed to the housing 221 of the compressor 220 with screws. A clutch electromagnet 235 is fixed to the pulley bearing support member 234. On the other hand, a power transmission member 236 is fitted to the shaft end of the main shaft 223. A car air conditioner electromagnetic clutch pulley 237 is fitted to the outer periphery of a grease-filled deep groove ball bearing 1 that is a rolling bearing for pulleys.

  A main shaft support bearing 232 is disposed between the main shaft 223 and the pulley bearing support member 234. Further, between the inner peripheral surface of the car air conditioner electromagnetic clutch pulley 237 and the pulley bearing support member 234, a grease-filled deep groove ball bearing 1 that is a rolling bearing for the car air conditioner electromagnetic clutch pulley is disposed.

  The grease-enclosed deep groove ball bearing 1 that is a rolling bearing for a car air conditioner electromagnetic clutch pulley has a configuration similar to that of the grease-enclosed deep groove ball bearing 1 as a motor rolling bearing in the embodiment of the present invention.

  In the pulley mechanism 230, the rotational driving force of the car air conditioner electromagnetic clutch pulley 237 rotating by a driving force (not shown) is transmitted to the main shaft 223 by exciting or de-energizing the clutch electromagnet 235 to the compressor. Or the rotation driving force of the car air conditioner electromagnetic clutch pulley 237 is not transmitted to the main shaft 223 and the compressor stops operating.

Next, the compressor bearing will be described.
The compressor bearing is roughly classified into a compressor bearing used for the compressor 220 and a compressor bearing used for the pulley mechanism 230.

  The compressor bearing used in the compressor 220 rotatably supports the swash plate support bearing 233 that rotatably supports the swash plate 222 and the rotating member 225, and the rotating member 225 and pulley bearing support member 234. The rotating member / pulley support member bearing 231 corresponds to this.

  The compressor bearings used in the pulley mechanism 230 include a spindle support bearing 232 that rotatably supports the spindle 223 and the pulley bearing support member 234, and a car air conditioner electromagnetic clutch pulley 237 and a pulley bearing support member 234. The grease-enclosed deep groove ball bearing 1 which is a rolling bearing for a car air-conditioner electromagnetic clutch pulley that supports the rotor in a freely rotating manner corresponds to this.

  Thrust needle roller bearings are used for the rotary member / pulley support member bearing 231 and the swash plate support bearing 233. As this thrust needle roller bearing, a thrust needle roller bearing 270 shown in FIG. 19 described later may be used. As the main shaft support bearing 232, a needle roller bearing or a cylindrical roller bearing is used. As this cylindrical roller bearing, a cylindrical roller bearing 20 shown in FIG. 8 may be used. A grease-enclosed deep groove ball bearing 1 shown in FIG. 2 is used for a grease-enclosed deep groove ball bearing 1 that is a rolling bearing for a car air conditioner electromagnetic clutch pulley. A double-row angular contact ball bearing may be used as the rolling bearing for the car air conditioner electromagnetic clutch pulley. As the double row angular ball bearing, a double row angular ball bearing 110 shown in FIG. 12 may be used.

  A thrust needle roller bearing having a large roller diameter is used for the compressor bearing used in the compressor 220 in order to withstand the impact of the piston 224. In addition, the thrust needle roller bearing has a structure in which the needle roller and the raceway surface are in line contact, and the raceway surface in contact with the needle roller and the rolling line has a circumferential speed from the rotation center of the bearing toward the outer diameter side. Becomes bigger.

  A thrust needle roller bearing, which is a compressor bearing used in the compressor 220, does not have a bearing disc like a normal bearing, and a plurality of needle rollers are held by a cage and are in line contact with the raceway surface. Then rotate. In the swash plate support bearing 233, each of the swash plate 222 and the rotation member 225 has a raceway surface. In the rotation member / pulley support member bearing 231, the rotation member 225 and the pulley bearing support member 234 each have a raceway surface. It becomes the member which has.

  The manufacturing method of the grease-enclosed deep groove ball bearing 1 that is a rolling bearing for a car air conditioner electromagnetic clutch pulley is the same as the manufacturing method of the grease-enclosed deep groove ball bearing 1 as a rolling bearing for a motor in the embodiment of the present invention. .

  Rolling bearings for car air conditioner electromagnetic clutch pulleys may cause early peeling due to hydrogen embrittlement, particularly due to the effect of sliding. In addition, with recent space savings, belts for driving electrical accessory parts including car air conditioners have been made serpentine. The load load tends to increase and the load fluctuation tends to increase, and slipping is more easily induced by serpentine formation.

  Since the grease-enclosed deep groove ball bearing 1 that is a rolling bearing for a car air conditioner electromagnetic clutch pulley is used for rotating the outer ring, a part of the inner ring 12 rotates a lot. Therefore, early peeling due to hydrogen embrittlement is likely to occur in a part of the inner ring 12, and it is preferable that the bearing member according to the embodiment of the present invention is applied to the inner ring 12.

  Further, the rolling bearing according to one embodiment of the present invention may be applied to a continuously variable transmission rolling bearing. Hereinafter, a rolling bearing for a continuously variable transmission will be described as another example of a rolling bearing according to an embodiment of the present invention, and the configuration of a continuously variable transmission provided with the same will be described.

  With reference to FIG. 16, a belt-type continuously variable transmission 240 will be described as an example of a continuously variable transmission according to an embodiment of the present invention. The belt type continuously variable transmission 240 includes a primary pulley shaft (pulley shaft) 241, a primary pulley 242, a secondary pulley shaft 243, a secondary pulley (pulley shaft) 244, an endless belt 245, and a casing (housing) 246. And a grease-filled deep groove ball bearing 1 which is a rolling bearing for continuously variable transmission.

  A primary pulley 242 is provided on the primary pulley shaft 241. The primary pulley 242 has a primary pulley fixed sheave 242a and a primary pulley movable sheave 242b. The primary pulley fixed sheave 242a is configured integrally with the primary pulley shaft 241. The primary pulley movable sheave 242b passes through the primary pulley shaft 241 and is configured to be slidable in the axial direction of the primary pulley shaft 241. One end of the primary pulley shaft 241 is connected to a clutch (not shown). The other end of the primary pulley shaft 241 is rotatably supported by a grease-filled deep groove ball bearing 1 which is a continuously variable transmission rolling bearing fixed to the casing 246.

  A secondary pulley 244 is provided on the secondary pulley shaft 243. The secondary pulley 244 has a secondary pulley fixed sheave 244a and a secondary pulley movable sheave 244b. The secondary pulley fixed sheave 244a is configured integrally with the secondary pulley shaft 243. The secondary pulley movable sheave 244b passes through the secondary pulley shaft 243 and is configured to be slidable in the axial direction of the secondary pulley shaft 243. Secondary pulley shaft 243 is supported by another bearing at one end to which a gear of a gear mechanism (not shown) is attached. The other end of the secondary pulley shaft 243 is rotatably supported by a grease-filled deep groove ball bearing 1 which is a continuously variable transmission rolling bearing fixed to the casing 246.

  A V-shaped endless belt 245 is stretched between the primary pulley 242 and the secondary pulley 244. The primary pulley 242 is configured such that the width (primary pulley width) between the primary pulley fixed sheave 242a and the primary pulley movable sheave 242b can be changed by sliding the primary pulley movable sheave 242b.

  The secondary pulley 244 is configured such that the width (secondary pulley width) between the secondary pulley fixed sheave 244a and the secondary pulley movable sheave 244b can be changed by sliding the secondary pulley movable sheave 244b. By changing the primary pulley width and the secondary pulley width, the primary pulley 242 and the secondary pulley 244 are configured such that the respective radial positions where the endless belt 245 is stretched are changed.

  Next, the operation of the belt type continuously variable transmission 240 will be described. A driving force is transmitted to the primary pulley shaft 241 from an engine (not shown) via a clutch. By changing the primary pulley width and the secondary pulley width, the respective radial positions where the endless belt 245 is stretched are changed. Thereby, the driving force of the primary pulley shaft 241 is transmitted to the secondary pulley shaft 243 at a continuously variable speed. A driving force is transmitted from the secondary pulley shaft 243 to the axle through a gear mechanism and a differential. Thereby, continuously variable transmission is achieved.

  The manufacturing method of the grease-enclosed deep groove ball bearing 1 that is the rolling bearing for continuously variable transmission is the same as the manufacturing method of the grease-enclosed deep groove ball bearing 1 as the motor rolling bearing in the embodiment of the present invention.

  For rolling bearings for continuously variable transmissions, it is important to reduce the backlash (axial clearance) of the bearings in order to ensure the rotational accuracy of the pulley. Conventionally, the groove curvature of the bearing inner and outer rings is reduced, A technique for reducing the axial clearance has been adopted. However, if the groove curvature of the inner and outer rings of the bearing is set to be small, the differential slip during the operation of the bearing becomes large, and the early peeling due to hydrogen embrittlement is likely to occur due to the influence.

  Since the grease-enclosed deep groove ball bearing 1 that is a rolling bearing for continuously variable transmission is used for inner ring rotation, a part of load rotation of the outer ring 11 is large. Therefore, early peeling due to hydrogen embrittlement is likely to occur in a part of the outer ring 11, and the bearing member according to the embodiment of the present invention is preferably applied to the outer ring 11.

  Moreover, the rolling bearing of one embodiment of the present invention may be applied to a needle roller bearing. When a needle roller bearing is used under conditions involving sliding such as rapid acceleration / deceleration, hydrogen is generated by separation of the lubricant, which may cause premature separation due to penetration into the steel. In the future, in order to cope with downsizing and energy saving, the use conditions of needle roller bearings will tend to become stricter, and it is expected that those with excellent hydrogen embrittlement resistance will be required.

  A shell-type needle roller bearing will be described as an example of a needle roller bearing which is another example of the rolling bearing according to the embodiment of the present invention.

  Referring to FIG. 17, shell needle roller bearing 250 includes shell outer ring 251 as a race member, needle rollers 252 as a plurality of rolling elements, and cage 253. The shell outer ring 251 has a raceway surface on the inner diameter surface. The shell outer ring 251 has flange portions 251a that protrude toward the inner diameter side in the radial direction at both ends in the axial direction. The needle rollers 252 are arranged along the raceway surface. The holder 253 is configured to hold the interval between adjacent needle rollers 252. The cage 253 is disposed on the inner side in the axial direction of the flange portion 251 a of the shell outer ring 251. The shell outer ring 251 may be an open end type or a closed end type.

  The manufacturing method of the shell needle roller bearing 250 according to the embodiment of the present invention is the same as the manufacturing method and the molding process of the rolling bearing for motor according to the embodiment of the present invention. In the forming step, steel members formed into a schematic shape such as the shell outer ring 251, the needle rollers 252, and the cage 253 shown in FIG. 17 are produced. The description of other manufacturing methods will not be repeated.

  Shell-shaped needle roller bearings are used for supporting air compressors of automobiles that accelerate and decelerate rapidly by switching electromagnetic clutches, and when used for supporting ABS pumps that accelerate quickly when starting. When used at the large end, the rolling elements are likely to slip, and early peeling due to hydrogen embrittlement may occur.

  A solid needle roller bearing will be described as an example of a needle roller bearing which is another example of the rolling bearing according to the embodiment of the present invention.

  Referring to FIG. 18, the solid needle roller bearing 260 includes an outer ring 261 as a race member, needle rollers 252 as a plurality of rolling elements, and a cage 253. The outer ring 261 is formed thick and has flange portions 261a that protrude toward the inner diameter side in the radial direction at both ends in the axial direction. The cage 253 is disposed on the radially inner side of the flange portion 261 a of the outer ring 261.

  The manufacturing method of the solid needle roller bearing 260 according to the embodiment of the present invention is the same as the manufacturing method and the molding process of the rolling bearing for motor according to the embodiment of the present invention. In the forming step, steel members formed into a schematic shape such as the outer ring 261, the needle rollers 252 and the cage 253 shown in FIG. 18 are produced. The description of other manufacturing methods will not be repeated.

  Solid needle roller bearings, especially when used to support automobile air compressors that accelerate and decelerate suddenly by switching electromagnetic clutches, when used to support transmissions that accelerate quickly during start-up, are large in connecting rods for general-purpose engines. When used at the end, slippage between contact elements is likely to occur, and early peeling due to hydrogen embrittlement may occur.

  A thrust needle roller bearing will be described as an example of a needle roller bearing which is another example of the rolling bearing according to the embodiment of the present invention.

  Referring to FIG. 19, the thrust needle roller bearing 270 includes a raceway disk 271 as a raceway member, needle rollers 252 as a plurality of rolling elements, and a cage 253. A washer outer diameter portion 271 a on which the needle rollers 252 roll is formed on the outer side of the washer 271. A washer protruding portion 271 b is formed at the tip of the washer 271 so as to protrude toward the inner diameter side in the radial direction. The thrust needle roller bearing 270 is configured such that the needle roller 252 and the retainer 253 are not separated from the washer 271 by disposing the tip of the retainer 253 on the inner side in the axial direction of the washer protrusion 271b. ing. The needle rollers 252 are arranged in the radial direction along the raceway surface. The cage 253 is configured to hold the interval between the adjacent needle rollers 252 in the circumferential direction.

  The manufacturing method of the thrust needle roller bearing 270 according to the embodiment of the present invention is the same as that of the rolling bearing for motor according to the embodiment of the present invention except for the molding process. In the forming step, steel members formed into a schematic shape such as the washer 271, the needle rollers 252, and the cage 253 shown in FIG. 19 are produced. The description of other manufacturing methods will not be repeated.

  The thrust needle roller bearing is constantly slipped from the rolling wheel during operation due to the difference in peripheral speed between the inside and outside of the rolling element, and may cause early separation due to hydrogen embrittlement.

  Further, the needle roller bearing according to the embodiment of the present invention may be a needle roller bearing with a cage. Referring to FIG. 20, cage 253 of needle roller bearing 280 with a cage may be made of a metal material. The cage 253 made of a metal material has high strength. In addition, referring to FIG. 21, cage 253 of needle roller bearing 280 with a cage may be made of a polymer material. The cage 253 made of a polymer material has a high degree of freedom in shape and is easy to incorporate.

  Needle roller bearings with cages, especially when used as idler bearings in automobile transmissions that accelerate quickly during start-up, when used as planetary pinion support bearings for CVTs, for large-end connecting rods of two-wheeled engines and general-purpose engines When used as a bearing or the like, the rolling elements are likely to slip, and early peeling due to hydrogen embrittlement may occur.

Next, the function and effect of the embodiment of the present invention will be described.
A rolling bearing according to an embodiment of the present invention is in contact with an outer ring 11 and an inner ring 12 as race members having an annular raceway, and contacts an outer ring 11 and an inner race 12 as race members, and rolls on an annular raceway. A ball 13 as a plurality of rolling elements arranged freely is provided. At least one bearing member among the outer ring 11 as the race member, the inner ring 12, the ball 13 as the rolling element, and the cylindrical roller 14 is made of JIS standard SUJ2.

  According to the rolling bearing of an embodiment of the present invention, at least one bearing member among the outer ring 11, the inner ring 12, and the balls 13 as rolling elements is hardened. At least one bearing member among the outer ring 11 as the race member, the inner ring 12 and the ball 13 as the rolling element has rolling surfaces 11A, 12A and 13A that are nitrided. By subjecting the rolling surfaces 11A, 12A, and 13A of the bearing member to nitriding treatment, the bearing member is less likely to be plastically deformed. By subjecting the rolling surfaces 11A, 12A, and 13A of the bearing member to nitriding treatment, the bearing member is less likely to be plastically deformed, thereby improving the hydrogen embrittlement resistance of the bearing member.

  According to the rolling bearing of an embodiment of the present invention, SUJ2 standard rolling bearing steel having a diameter of 19.05 mm is provided on at least one bearing member among the outer ring 11, the inner ring 12 and the ball 13 as a rolling element. By pressing the sphere with a load of 3.18 kN, holding it for 10 seconds and then unloading it, the depth of the indentation formed on the bearing member is 0.2 μm or less. If the indentation depth is 0.2 μm or less as a guide, it can be said that plastic deformation is difficult. Therefore, when the relationship between the tempering temperature and the indentation depth was investigated in detail, if a tempering process was performed at 240 ° C. or higher and 300 ° C. or lower, a SUJ2 standard rolling bearing steel ball with a diameter of 19.05 mm was loaded on the bearing member. It was found that the depth of the indentation formed on the bearing member was 0.2 μm or less by unloading after pressing at 3.18 kN and holding for 10 seconds.

  According to the rolling bearing of one embodiment of the present invention, the Rockwell C scale hardness of the rolling surface of at least one bearing member among the outer ring 11 as the race member, the inner ring 12 and the ball 13 as the rolling element is HRC61. .2 or more and HRC63.3 or less. It was found that the Rockwell C scale hardness of the rolling surface of the bearing member in the tempering temperature range of 240 ° C. to 300 ° C. was HRC 61.2 to HRC 63.3.

  Therefore, by tempering the bearing member having the nitriding rolling surfaces 11A, 12A, and 13A at a tempering temperature of 240 ° C. or higher and 300 ° C. or lower, it is difficult to plastically deform and make it difficult to generate atomic vacancies. Can do. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  Moreover, according to the rolling bearing of one embodiment of the present invention, the surface nitriding concentration of the rolling surfaces 11A, 12A, 13A is 0.05% by mass or more and 0.4% by mass or less.

  If the surface nitriding concentration of the rolling surfaces 11A, 12A, and 13A is less than 0.05% by mass, the effect of improving the life due to nitriding cannot be obtained sufficiently. If the surface nitriding concentration of the rolling surfaces 11A, 12A, and 13A is larger than 0.4% by mass, a large amount of Cr carbonitride is generated, so that the Cr amount contributing to hardenability is deficient. Therefore, sufficient hardenability cannot be ensured. By making the surface nitridation concentration of the rolling surfaces 11A, 12A, and 13A 0.05 mass% or more and 0.4 mass% or less, the effect of improving the life by nitriding can be sufficiently obtained, and sufficient hardenability can be obtained. It can also be secured.

  Moreover, according to the rolling bearing of one embodiment of the present invention, the ball 13 as the rolling element may be JIS standard SUJ2 which is not nitrided. In this case, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm is pressed against the ball 13 with a load of 1.97 kN, held for 10 seconds, and then unloaded, so that the depth of the impression formed on the ball 13 is 0.00. 2 μm or less. If the indentation depth is 0.2 μm or less as a guide, it can be said that plastic deformation is difficult. Therefore, when the relationship between the tempering temperature and the indentation depth was investigated in detail, if a tempering process was performed at 240 ° C. or higher and 280 ° C. or lower, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm was loaded on the bearing member. It was found that the depth of the indentation formed on the ball 13 was 0.2 μm or less by unloading after pressing at 1.97 kN and holding for 10 seconds.

  Therefore, by tempering the ball 13 having no rolling surface 13A subjected to nitriding treatment at a tempering temperature of 240 ° C. or higher and 280 ° C. or lower, it is difficult to plastically deform and make it difficult to generate atomic vacancies. Can do. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  In the rolling bearing described above, the Rockwell C scale hardness of the entire rolling element is preferably HRC57.0 or more and HRC58.9 or less. The Rockwell C scale hardness of the whole rolling element in the range of tempering temperature 240 or more and 280 or less is HRC57.0 or more and HRC58.9 or less.

  Moreover, according to the rolling bearing of one embodiment of the present invention, the rolling element may be made of a material containing ceramics. Thereby, since the rolling element is made of a material containing ceramics that does not exhibit hydrogen embrittlement, the hydrogen embrittlement resistance can be improved, so that early peeling due to hydrogen embrittlement can be suppressed.

  Moreover, according to the rolling bearing of one embodiment of the present invention, it may further include a cage for holding the rolling elements, and the cage may be made of a material containing metal. Thereby, under the condition where energization occurs, the metal cage is less likely to cause early peeling due to hydrogen embrittlement than the resin cage, and therefore, early peeling due to hydrogen embrittlement can be suppressed.

  According to the rolling bearing manufacturing method of an embodiment of the present invention, the outer ring 11 and the inner ring 12 as race members having an annular raceway and the outer ring 11 and the inner race 12 as race members are brought into contact with each other. And a ball 13 as a plurality of rolling elements arranged on the track so as to freely roll, and includes the following steps. At least one bearing member among the outer ring 11 as the race member, the inner ring 12 and the ball 13 as the rolling element is prepared to be made of a material of JIS standard SUJ2. The rolling surfaces 11A, 12A, and 13A of the bearing member are subjected to nitriding treatment and quenched. The quenched bearing member is tempered at 240 ° C. or higher and 300 ° C. or lower.

  The outer race 11, the inner race 12, and the ball 13 as the bearing members are less likely to be plastically deformed by nitriding and quenching the rolling surfaces 11A, 12A, and 13A of the bearing members. Nitriding treatment is performed on the rolling surfaces 11A, 12A, and 13A of the bearing member to make the bearing member difficult to be plastically deformed, thereby improving the hydrogen embrittlement resistance of the bearing member.

  By tempering the quenched bearing member at 240 ° C. or higher and 300 ° C. or lower, the bearing member is less likely to be plastically deformed, and it is possible to make it difficult to generate atomic vacancies. Thereby, since hydrogen embrittlement resistance can be improved, early peeling due to hydrogen embrittlement can be suppressed.

  Further, according to the method for manufacturing a rolling bearing of one embodiment of the present invention, the nitriding treatment is performed at a temperature of 850 ° C. in an atmosphere in which ammonia gas is added to RX gas. Thereby, sufficient nitriding treatment is performed on the rolling surfaces 11A, 12A, and 13A of the bearing member to make the bearing member difficult to be plastically deformed, so that the hydrogen embrittlement resistance of the bearing member can be improved.

  Further, according to the rolling bearing of the embodiment of the present invention, as shown in FIG. 1, the rolling bearing further includes a main shaft 92 of the motor 90 and a housing 93 disposed so as to face the outer peripheral surface of the main shaft 92. The main shaft 92 may be rotatably supported with respect to the housing 93. As a result, early peeling due to hydrogen embrittlement can be suppressed.Therefore, long-life rolling bearings for motors can be obtained even under severe usage conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where energization occurs. Can be provided.

  Further, according to the rolling bearing of the embodiment of the present invention, as shown in FIG. 6, the rolling bearing further includes a main shaft 101 of the machine tool 100 and a housing 102 arranged to face the outer peripheral surface of the main shaft 101. The main shaft 101 may be rotatably supported with respect to the housing 102. As a result, early peeling due to hydrogen embrittlement can be suppressed, so that rolling for machine tool spindles with a long service life is possible even under severe conditions such as conditions where water enters the bearings, conditions involving slippage, and conditions where current is applied. A bearing can be provided. Further, it is possible to provide a rolling bearing for a machine tool spindle that has a long life even under use conditions in which the oil film thickness of the lubricating oil is reduced in order to reduce the friction torque of the bearing that causes heat generation during high-speed rotation.

  Further, according to the rolling bearing of one embodiment of the present invention, it is effective even in the case of general grease lubrication or air-oil lubrication, but by lubricating with a small amount of lubricating oil, between the race member and the rolling element. This is particularly effective when the oil film is thin.

  The lubrication apparatus 40 that uses a lower viscosity lubricating oil while reducing the amount of oil described above is operated at a higher speed than the air-oil lubrication generally used in rolling bearings for machine tool main spindles that rotate at high speeds. It is easy for basation to occur. Therefore, the oil film is thinner than air-oil lubrication. For this reason, in this lubricating device 40, since hydrogen easily enters, the possibility of early peeling due to hydrogen embrittlement increases. However, application of the rolling bearing according to the embodiment of the present invention can suppress early peeling due to hydrogen embrittlement.

  Further, in the lubricating device 60 that utilizes the capillary phenomenon, starvation is likely to occur when operating at a speed higher than that of normal grease lubrication. For this reason, since the hydrogen easily enters the lubricating device 60, the possibility of early peeling due to hydrogen embrittlement increases. However, application of the rolling bearing according to the embodiment of the present invention can suppress early peeling due to hydrogen embrittlement.

  Moreover, according to the rolling bearing of one embodiment of the present invention, as shown in FIG. 11, the rotation side member of the wheel 120 and the fixed side member arranged so as to face the outer peripheral surface of the rotation side member. Furthermore, the rotation side member may be rotatably supported with respect to the fixed side member. As a result, early peeling due to hydrogen embrittlement can be suppressed.Therefore, a rolling bearing for wheels that has a long service life can be obtained even under severe conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where current is applied. Can be provided. Further, since the early peeling due to hydrogen embrittlement can be suppressed even under conditions where the bearing vibrates, a long-life wheel rolling bearing can be provided.

  Moreover, according to the rolling bearing of one embodiment of the present invention, as shown in FIG. 13, the rolling bearing further includes a main shaft 201 of the alternator 200 and a housing 205 arranged so as to face the outer peripheral surface of the main shaft 201. The main shaft 201 may be rotatably supported with respect to the housing 205. As a result, early peeling due to hydrogen embrittlement can be suppressed, so long-life alternator rolling bearings can be used even under severe operating conditions such as conditions where water is mixed in the bearing, conditions involving slippage, and conditions where current is applied. Can be provided. Providing rolling bearings for alternators that have a long life by suppressing early delamination due to hydrogen embrittlement, especially under operating conditions where sliding due to hydrogen embrittlement is likely to occur due to the effect of slippage between contact elements under rapid acceleration / deceleration conditions can do. In addition, it is possible to suppress the early peeling due to hydrogen embrittlement even under conditions where slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine formation, so a rolling bearing for an alternator with a long life is provided. Can do.

  Further, according to the rolling bearing of one embodiment of the present invention, as shown in FIG. 14, the rolling bearing further includes a main shaft 218 and a pulley main body 211 arranged so as to face the outer peripheral surface of the main shaft 218. May be rotatably supported with respect to the pulley body 211. As a result, early peeling due to hydrogen embrittlement can be suppressed.Therefore, long-life pulley rolling bearings can be used even under severe conditions such as conditions where water enters the bearings, conditions involving slippage, and conditions where current is applied. Can be provided. Also, since it is possible to suppress early peeling due to hydrogen embrittlement even under conditions in which slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine conversion, a long-life pulley rolling bearing is provided. Can do.

  Further, according to the rolling bearing of one embodiment of the present invention, as shown in FIG. 15, a car air conditioner electromagnetic clutch pulley 237 and a pulley disposed so as to face the inner peripheral surface of the car air conditioner electromagnetic clutch pulley 237. And a car air conditioner electromagnetic clutch pulley 237 may be rotatably supported with respect to the pulley bearing support member 234. As a result, early peeling due to hydrogen embrittlement can be suppressed, so the car air conditioner electromagnetic clutch pulley has a long life even under severe usage conditions such as conditions where water enters the bearings, conditions involving slippage, and conditions where current is applied. A rolling bearing can be provided. In addition, rolling bearings for car air conditioner electromagnetic clutch pulleys that have a long service life can be prevented because early peeling due to hydrogen embrittlement can be suppressed even under conditions in which slippage is induced more than before due to increased load load and increased load fluctuation associated with serpentine conversion. Can be provided.

  Further, according to the rolling bearing of the embodiment of the present invention, as shown in FIG. 16, the housing 246 is disposed so as to face the pulley shaft 241 of the continuously variable transmission 240 and the outer peripheral surface of the pulley shaft 241. And the pulley shaft 241 may be rotatably supported with respect to the housing 246. As a result, early peeling due to hydrogen embrittlement can be suppressed. For continuously variable transmissions that have a long life even under severe conditions such as conditions where water enters the bearings, conditions involving slippage, and conditions where current is applied. A rolling bearing can be provided. In addition, since the groove curvature of the inner and outer rings of the bearing is set to be small in order to suppress the axial clearance of the bearing, it is possible to suppress early peeling due to hydrogen embrittlement even under conditions where differential sliding during bearing operation is large. A rolling bearing for a continuously variable transmission can be provided.

  Further, the rolling bearing according to one embodiment of the present invention may be a shell needle roller bearing 250 as shown in FIG. Shell-type needle roller bearings are used in ABS pumps that accelerate quickly when starting, especially when used in support of air compressors in automobiles that suddenly accelerate or decelerate by switching electromagnetic clutches under conditions involving sudden acceleration and deceleration. When used for support or when used for the large end of a connecting rod of a general-purpose engine, the rolling elements are likely to slip, and early peeling due to hydrogen embrittlement may occur. According to the rolling bearing of one embodiment of the present invention, it is possible to provide a long-life shell needle roller bearing 250 because early peeling due to hydrogen embrittlement can be suppressed even under such conditions.

  Further, the rolling bearing according to the embodiment of the present invention may be a solid needle roller bearing 260 as shown in FIG. Solid needle roller bearings support transmissions that accelerate quickly during start-up, especially when used to support air compressors in automobiles that accelerate and decelerate suddenly by switching electromagnetic clutches under conditions involving sudden acceleration and deceleration. In the case of being used for a large-sized connecting rod of a general-purpose engine, slippage between contact elements is likely to occur, and early peeling due to hydrogen embrittlement may occur. According to the rolling bearing of one embodiment of the present invention, it is possible to provide a long-life solid needle roller bearing 260 because early peeling due to hydrogen embrittlement can be suppressed even under such conditions.

  Further, the rolling bearing according to the embodiment of the present invention may be a thrust needle roller bearing 270 as shown in FIG. The thrust needle roller bearing is constantly slipped from the rolling wheel during operation due to the difference in peripheral speed between the inside and outside of the rolling element, and may cause early separation due to hydrogen embrittlement. Thrust needle roller bearings may experience early peeling due to hydrogen embrittlement even under conditions involving slippage such as rapid acceleration and deceleration. According to the rolling bearing of one embodiment of the present invention, it is possible to provide the long-lasting thrust needle roller bearing 270 because early peeling due to hydrogen embrittlement can be suppressed even under such conditions.

  Moreover, the needle roller bearing of one embodiment of the present invention may include a cage 253 as shown in FIGS. Needle roller bearings with cages are used under idle conditions such as sudden acceleration / deceleration, especially when used as idler bearings for automobile transmissions that accelerate quickly at start-up, and as planetary pinion support bearings for CVT. When used as a large-end bearing for a connecting rod of a two-wheeled engine or a general-purpose engine, the rolling elements are likely to slip and may cause early separation due to hydrogen embrittlement. According to the rolling bearing of an embodiment of the present invention, it is possible to provide a long-life needle roller bearing 280 with a cage because early peeling due to hydrogen embrittlement can be suppressed even under such conditions.

Examples of the present invention will be described below.
Example 1
In order to evaluate the mechanical characteristics of the raceway member and rolling element of the rolling bearing of the present invention, the following tests were conducted. Hereinafter, the test procedure, test conditions, and test results of each test will be described. Although SUJ2 of this invention should just have a chemical component of JIS specification SUJ2, in this Example, SUJ2 which has a chemical component shown in Table 1 as an example was made into the test piece. In SUJ2 of this example, as chemical components, C (carbon), Si (silicon), Mn (manganese), P (phosphorus), S (sulfur), Cr (chromium), Mo (molybdenum), Ni (nickel) Cu (copper), Al (aluminum), Ti (titanium), and O (oxygen).

(1) Indentation test A plurality of disk-shaped test pieces having a final surface finished to a mirror surface with a diamond paste having a diameter of 12 mm, a width of 2 mm, and a width of 1 μm were prepared. In the heat treatment, a plurality of test pieces were each hardened by heating for 180 minutes in an atmosphere in which ammonia gas was added to RX gas at 850 ° C. for nitriding treatment. Thereafter, each test piece was tempered for 120 minutes at a plurality of tempering temperatures of 180 ° C. to 320 ° C., respectively. Thereafter, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm was pressed against the flat part of the width surface of each test piece with a load of 3.18 kN with a maximum contact surface pressure of 4.4 GPa calculated by elastic Hertz contact, and held for 10 seconds. Then, the depth of the indentation formed on the test piece was measured by unloading. In the elastic Hertz contact calculation, the SUJ2 Young's modulus and Poisson's ratio were 204 GPa and 0.3 which were measured values and did not depend on the tempering temperature. The Young's modulus and Poisson's ratio of SUJ2 standard rolling bearing steel balls were also 204 GPa and 0.3. The test results are shown in Table 2 and FIG. 22, and the relationship between the tempering temperature and the indentation depth is shown.

  Referring to FIG. 22, the indentation became shallowest by tempering around 260 ° C. That is, it can be said that plastic deformation hardly occurs at a tempering temperature of about 260 ° C. below the maximum practical contact surface pressure acting between the contact elements between the raceway member of the rolling bearing and the rolling element. As a guide, it can be said that plastic deformation is difficult if it is in the range of 240 ° C. or more and 300 ° C. or less, which is a tempering temperature at which the indentation depth is 0.2 μm or less. Since atomic vacancies are generated by plastic deformation, that is, by interaction of dislocations, the resistance to hydrogen deformation is superior in resistance to plastic deformation. Therefore, it was found that the hydrogen embrittlement resistance was excellent in the range of 240 ° C. or higher and 300 ° C. or lower.

(2) HRC (Rockwell C scale) hardness test It is well known that the hardness decreases as the tempering temperature increases. This is because the hardness measurement gives extremely large plastic deformation. For example, the maximum contact surface pressure in elastic Hertz contact calculation in steel HRC (Rockwell C scale) hardness measurement (conical diamond indenter with a tip radius of 0.2 mm, indentation load is 150 kgf) is 63.8 GPa. In the elastic Hertz contact calculation, the Young's modulus and Poisson's ratio of steel were 204 GPa and 0.3, and the Young's modulus and Poisson's ratio of indenter were 1141 GPa and 0.07.

  The HRC hardness of a test piece having the same dimensions as the above (1) indentation test and heat-treated under the same conditions was measured. Table 3 and FIG. 23 show the test results and show the relationship between the tempering temperature and the HRC hardness.

  Referring to FIG. 23, the HRC hardness in the range where the tempering temperature is 240 ° C. or higher and 300 ° C. or lower is HRC 61.2 or higher and HRC 63.3 or lower.

(3) Surface nitridation concentration measurement test The surface nitridation concentration was measured by Electron Probe Micro Analyzer (EPMA). Specifically, the measurement was performed under the measurement conditions shown in Table 4. That is, using EPMA-1600 manufactured by Shimadzu Corporation as a model of the measuring instrument, measurement was performed at an acceleration voltage of 15 kV, a spot diameter of 2 μm, a measurement interval of 2 μm, and a measurement time of 1 sec (seconds).

  As a measuring method, a test piece having the same dimensions as the above (1) indentation test and heat-treated under the same conditions was cut so that the surface and the inside appeared in the cross section. The cut specimen TP was embedded in a resin RE as shown in FIG. 24 and mirror polished. Subsequently, the polished surface was degreased. Thereafter, the nitrogen concentration distribution in the steel was measured by EPMA in the direction of the arrow in FIG. As a result, the nitrogen concentration distribution in the depth direction from the surface of the test piece corresponding to the rolling surface was measured. Table 5 and FIG. 25 show the test results and show the relationship between the nitrogen concentration and the depth from the surface. Table 5 and FIG. 25 are prepared with some of the measured values for convenience.

  Referring to Table 5 and FIG. 25, the surface nitrogen concentration of this test piece was about 0.4% by mass. Here, the surface is a range from 0 to 0.01 mm in depth from the surface. Nitrogen concentration decreases with depth from the surface. The nitridation concentration is about 0.2% by mass when the depth from the surface is 0.048 mm, becomes very low at 0.0097% by mass when the depth from the surface is 0.31 mm, and the depth from the surface is 0. It became substantially 0 at .41 mm or more.

(4) Rolling fatigue test in water-mixed oil Under rolling contact conditions where water is mixed, water is decomposed to generate hydrogen, which penetrates into the steel and causes early peeling. Therefore, a rolling fatigue test was conducted in water-mixed oil.

  Referring to FIG. 26, a tapered outer ring test piece 80 was created. The taper-shaped outer ring test piece 80 has a width W14 mm (tolerance +0, −0.01 mm), an outer diameter ODφ72 mm (tolerance +0, −0.01 mm), and an inner diameter ID1φ51.19 mm (tolerance ± 0. 025 mm), an inner diameter ID2φ of 67.12 mm (tolerance ± 0.025 mm) on the side where the taper shape expands, and an opposing angle A between the taper shapes A59.3 ° (tolerance ± 0.5 °). After the heat treatment, grinding finishing was performed, and the inner raceway surface was superfinished to a surface roughness Rq (root mean square roughness) of 0.03 μm.

  The heat treatment was performed by heating for 180 minutes in an atmosphere in which ammonia gas was added to RX gas at 850 ° C., followed by nitriding treatment and quenching. Thereafter, in the examples, tempering was performed for 120 minutes at 260 ° C., which was the tempering temperature at which indentation was hardest in the above (1) indentation test. On the other hand, in a comparative example for comparison with the example, tempering was performed at 180 ° C., which is a standard tempering temperature, for 120 minutes.

Referring to FIG. 27, the test was performed by combining tapered inner ring test piece 80 with inner ring 81 of angular ball bearing (JIS standard 7306B), thirteen steel balls 82, and cage 83. The inner ring 81 and the steel ball 82 of the angular ball bearing are SUJ2 standard quenching and tempering products. The water-mixed oil is 7 mass in ISO VG100 additive-free turbine oil (density 0.887 g / cm ³ , kinematic viscosity at 40 ° C. 100.9 mm ² / s, kinematic viscosity at 100 ° C. 11.68 mm ² / s). % (Tolerance ± 0.01% by mass) of pure water. After making the water-mixed oil, it was sealed with a thin film for food packaging so that water would not evaporate, and stirred with a stirrer for 2 hours or more. Thereafter, a test was conducted with the water-containing oil. 60 mL of water-mixed oil was injected. As shown in FIG. 27, because of the tapered shape, a water-mixed oil flows in the direction of arrow Y in the figure. The water-containing oil was circulated by connecting a water-containing oil inlet / outlet provided in a housing (not shown) with a nylon tube.

Only the axial load Fa (2.94 kN) was applied, and the inner ring was rotated at a rotational speed of 2733 revolutions per minute. The maximum contact surface pressure between the outer ring and the steel ball in the elastic Hertz contact calculation at this time is 3 GPa. In the elastic Hertz contact calculation, the Young's modulus and Poisson's ratio of the tapered outer ring specimen 80 and the SUJ2 steel ball 82 were set to 204 GPa and 0.3. The oil film parameter between the outer ring and the steel ball in the elastohydrodynamic lubrication calculation ignoring water contamination is about 3. However, the surface roughness of the steel ball was constant at 0.0178 μm as measured value Rq. The calculated life L _10h of the taper-shaped outer ring test piece 80 alone is 2611 hours when converted into a two-cylinder model and calculated. However, the effect of slip was ignored. The separation was detected with a vibrometer. The test was conducted for 20 hours, and if it did not peel off during that time, it was replaced with a newly prepared water-mixed oil. The test for 20 hours and the exchange of water-containing oil were repeated until peeling occurred.

  The test was conducted for each of the five examples and comparative examples. All peeling occurred on the taper-shaped outer ring test piece 80, and all of the peeling started from the inside of the surface layer. The SUJ2 steel ball 82 is a standard quenching and tempering product, but no peeling occurred. This is probably because the steel ball 82 has a larger effective load volume than the tapered outer ring test piece 80.

Table 6 shows the test results, and shows L ₁₀ , L ₅₀ and Weibull slope (shape parameter) e obtained by applying the peeling life of the example and the comparative example to the 2-parameter Weibull distribution.

L ₁₀ of the comparative example is 42.8 hours, was calculated life L _10h 1 to about 60 minutes of 2611 hours is. In contrast, the L ₁₀ embodiment, although not inferior to the calculated life L _10h and 560.3 hours, showed about 13 times longer life compared with the comparative example. From this, it was found that the examples had an effect of making it difficult to cause early peeling due to hydrogen embrittlement.

(Example 2)
In order to evaluate the mechanical characteristics of the rolling element when the rolling element of the rolling bearing according to the present invention conforming to JIS standard SUJ2 is not nitrided, test procedures, test conditions, and test results of each test will be described below. In addition, about the matter similar to said Example 1, description other than what is shown below is not repeated. The SUJ2 constituting the rolling element of the rolling bearing of the present invention may have a chemical component of JIS standard SUJ2, but in this example, SUJ2 having the chemical components shown in Table 1 was used as a test piece as an example.

(1) Indentation test A plurality of disk-shaped test pieces having a final surface finished to a mirror surface with a diamond paste having a diameter of 12 mm, a width of 2 mm, and a width of 1 μm were prepared. In the heat treatment, each of the plurality of test pieces was heated in an RX gas atmosphere at 850 ° C. for 80 minutes to perform quenching. Thereafter, each test piece was tempered for 120 minutes at a plurality of tempering temperatures of 180 ° C. to 350 ° C., respectively. Thereafter, a SUJ2 standard rolling bearing steel ball having a diameter of 19.05 mm was pressed against the flat portion of the width surface of each test piece with a load of 1.97 kN with a maximum contact surface pressure of 3.8 GPa by elastic hertz contact calculation, and held for 10 seconds. Then, the depth of the indentation formed on the test piece was measured by unloading. In the elastic Hertz contact calculation, the SUJ2 Young's modulus and Poisson's ratio were 204 GPa and 0.3 which were measured values and did not depend on the tempering temperature. The Young's modulus and Poisson's ratio of SUJ2 standard rolling bearing steel balls were also 204 GPa and 0.3. Table 7 and FIG. 28 show the test results and show the relationship between the tempering temperature and the indentation depth.

  Referring to FIG. 28, the indentation became shallowest when tempering around 260 ° C. That is, it can be said that plastic deformation hardly occurs at a tempering temperature of about 260 ° C. below the maximum practical contact surface pressure acting between the contact elements between the raceway member of the rolling bearing and the rolling element. As a guideline, it can be said that plastic deformation is difficult if it is in the range of 240 ° C. or higher and 280 ° C. or lower, which is the tempering temperature at which the indentation depth is 0.2 μm or less. Since atomic vacancies are generated by plastic deformation, that is, by interaction of dislocations, the resistance to hydrogen deformation is superior in resistance to plastic deformation. Therefore, it was found that the hydrogen embrittlement resistance was excellent in the range of 240 ° C. or higher and 280 ° C. or lower.

(2) HRC (Rockwell C scale) hardness test The HRC hardness of a test piece having the same dimensions as the above (1) indentation test and heat-treated under the same conditions was measured. The test results are shown in Table 8 and FIG. 29, and the relationship between the tempering temperature and the HRC hardness is shown.

  Referring to FIG. 29, the HRC hardness in the range where the tempering temperature is 240 ° C. or higher and 280 ° C. or lower is HRC 57.0 or higher and HRC 58.9 or lower.

(3) Rolling fatigue test in water-mixed oil A tapered outer ring test piece 80 shown in FIG. 26 was prepared. The heat treatment is different from Example 1. The heat treatment was performed by quenching by heating in an RX gas atmosphere at 850 ° C. for 80 minutes. Thereafter, in the examples, tempering was performed for 120 minutes at 260 ° C., which was the tempering temperature at which indentation was hardest in the above (1) indentation test. On the other hand, in a comparative example for comparison with the example, tempering was performed at 180 ° C., which is a standard tempering temperature, for 120 minutes.

  Similarly to Example 1, referring to FIG. 26, the test was performed by combining tapered outer ring test piece 80 with inner ring 81 of angular ball bearing (JIS standard 7306B), 13 steel balls 82 and cage 83. It was. Using these, the same test as in Example 1 was performed. In this example, 5% by mass (tolerance ± 0.01% by mass) of pure water was mixed to prepare a water-mixed oil. Except for this, the test was performed under the same conditions as in Example 1.

Table 9 shows the test results, and shows L ₁₀ , L ₅₀ and Weibull slope (shape parameter) e obtained by applying the peeling life of the present example and the comparative example to the 2-parameter Weibull distribution.

L ₁₀ of the comparative example is 33.7 hours, was calculated life L _10h 1 to about 100 minutes of 2611 hours is. In contrast, L ₁₀ of the present embodiment, although it did not reach the calculated life L _10h and 517.3 hours, was about 15 times longer life compared with the comparative example. From this, it was found that this example had an effect of making it difficult to cause early peeling due to hydrogen embrittlement.

  In addition, in SUJ2 which has the chemical component of the range prescribed | regulated to JIS specification SUJ2, it confirmed that the test result similar to Example 1 and Example 2 was obtained.

The above-described embodiment of the present invention is combined in a timely manner.
It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be particularly advantageously applied to a rolling bearing and a manufacturing method of a rolling bearing in which at least one bearing member of the race member and the rolling element is made of JIS standard SUJ2.

  DESCRIPTION OF SYMBOLS 1 Grease filled deep groove ball bearing 10, 30, 50 Angular contact ball bearing, 11, 261 Outer ring, 11A Outer ring rolling surface, 11b Stepped surface, 12 Inner ring, 12A Inner ring rolling surface, 12B Slope, 13 Ball, 13A Ball rolling Running surface, 14,253 Cage, 15 Seal member, 16 Grease composition, 20 Cylindrical roller bearing, 23A Roller rolling surface, 31 Lubricating oil introduction member, 31a Hook-shaped portion, 31b Seal portion, 31c Lubricating oil supply path, 31d Discharge port, 31e Oil draining circumferential groove, 32 Lid member, 33 Inner ring spacer, 34 Oil receiving circumferential groove, 40,60 Lubricator, 61 spacer, 62 Grease reservoir forming member, 62a Tip, 63 Grease reservoir Part, 64 flow path, 65 gap, 66 taper surface, 80 taper-shaped outer ring test piece, 81 inner ring, 82 steel ball, 83 cage, 90, 103 motor 91 rotor, 92, 101, 223 spindle, 92A outer peripheral surface, 93 frame, 94 commutator, 95 brush, 96 stator, 100 machine tool, 101A outer peripheral surface, 101B tip, 102, 221 housing, 102A inner wall, 103A motor stator, 103B motor rotor, 110 double row angular contact ball bearing, 111 wheel, 112 tire, 113 hub wheel, 114 knuckle, 115 magnetic encoder, 116 magnetic sensor, 120 wheel, 200 alternator, 201, 218 shaft, 202 rotor, 203 stator, 204 pulley , 205 housing, 210 pulley, 211 pulley body, 220 compressor, 222 swash plate, 224 piston, 225 rotating member, 226 piston rod, 230 compressor Pulley mechanism, 231 rotating member / pulley support member bearing, 232 spindle support bearing, 233 swash plate support bearing, 234 pulley bearing support member, 235 electromagnet for clutch, 236 power transmission member, 237 car air conditioner electromagnetic clutch pulley, 240 belt Type continuously variable transmission, 241 primary pulley shaft, 242 primary pulley, 242a primary pulley fixed sheave, 242b primary pulley movable sheave, 243 secondary pulley shaft, 244 secondary pulley, 244a secondary pulley fixed sheave, 244b secondary pulley movable sheave, 245 endless Belt, 246 casing, 250 shell needle roller bearing, 251 shell outer ring, 251a collar, 252 needle roller, 260 solid needle roller bearing, 270 thrust needle roller Bearing, 271 washer, 271a washer outer diameter, 271b washer protrusion, 280 needle roller bearing with cage.

Claims (8)

A raceway member having an annular raceway;
A plurality of rolling elements which are in contact with the raceway member and arranged to roll on the raceway,
At least one bearing member of the raceway member and the rolling element is made of JIS standard SUJ2,
The bearing member is hardened, and the bearing member has a nitriding rolling surface;
By pressing a steel ball for SUJ2 standard rolling bearing with a diameter of 19.05 mm against the bearing member with a load of 3.18 kN, holding for 10 seconds and then unloading, the depth of indentation formed on the bearing member is 0.2 μm. And
A rolling bearing having a Rockwell C scale hardness of HRC61.2 or more and HRC63.3 or less of the rolling surface.   The rolling bearing according to claim 1, wherein a surface nitriding concentration of the rolling surface is 0.05% by mass or more and 0.4% by mass or less. The rolling element is made of JIS standard SUJ2 which is not nitrided,
A steel ball for SUJ2 standard rolling bearing with a diameter of 19.05 mm is pressed against the rolling element at a load of 1.97 kN, held for 10 seconds, and then unloaded, so that the depth of indentation formed on the rolling element is 0.2 μm. The rolling bearing according to claim 1 or 2, wherein:   The rolling bearing according to claim 3, wherein the Rockwell C scale hardness of the entire rolling element is HRC57.0 or more and HRC58.9 or less.   The rolling bearing according to claim 1, wherein the rolling element is made of a material containing ceramics. Further comprising a cage for holding the rolling element,
The rolling bearing according to claim 1, wherein the cage is made of a material containing metal. A rolling bearing manufacturing method comprising: a raceway member having an annular raceway; and a plurality of rolling elements that are in contact with the raceway member and arranged to roll on the raceway raceway,
Preparing at least one bearing member of the raceway member and the rolling element so as to be made of a material of JIS standard SUJ2,
Nitriding the rolling surface of the bearing member and quenching;
And a step of tempering the quenched bearing member at 240 ° C. or higher and 300 ° C. or lower.   The method of manufacturing a rolling bearing according to claim 7, wherein the nitriding treatment is performed in an atmosphere in which ammonia gas is added to RX gas at a temperature of 850 ° C.

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