Abstract: A self-aligning clutch release bearing in which consideration is taken for a fiber flow in a steel sheet of which a side plate is made. Specifically, the side plate is formed with cutout portions at locations where an imaginary line passing through the cutout portions and the center of an inner-diameter portion is across the fiber flow in the steel sheet of which the side plate is made. With this arrangement, the present invention makes it possible that cracks do not develop easily from the cutout portions when a flange portion is formed by means of burring process after the side plate is punched by means of blanking process. This leads to improved yield and increased strength of the side plate.

Abstract: A bearing seal (26) includes an elastically deformable waist portion (29), a first lip (31) protruding axially inside direction, and a second lip (32) protruding axially outside. In a free situation without the fastening allowance C, a center of gravity F of a portion that includes the waist portion, the first lip, and the second lip is present in an axial inside with respect to a rotation center X of the portion, and an axial distance A from the rotation center X to the center of gravity F is included in a range of more than 0 and less than the fastening allowance C.

Abstract: A bearing seal (26) includes an elastically deformable waist portion (29), a first lip (31) protruding axially inside direction, and a second lip (32) protruding axially outside. In a free situation without the fastening allowance C, a center of gravity F of a portion that includes the waist portion, the first lip, and the second lip is present in an axial inside with respect to a rotation center X of the portion, and an axial distance A from the rotation center X to the center of gravity F is included in a range of more than 0 and less than the fastening allowance C.

Abstract: The present invention provides a self-aligning clutch release bearing in which consideration is taken for a fiber flow in a steel sheet of which a side plate is made. Specifically, the side plate is formed with cutout portions at locations where an imaginary line passing through the cutout portions and the center of an inner-diameter portion is across the fiber flow in the steel sheet of which the side plate is made. With this arrangement, the present invention makes it possible that cracks do not develop easily from the cutout portions when a flange portion is formed by means of burring process after the side plate is punched by means of blanking process. This leads to improved yield and increased strength of the side plate.

Abstract: A retainer for a ball bearing includes two annular members that face each other in an axial direction thereof. The two annular members include opposed surfaces each having hemispherical pockets that are formed at positions in a circumferential direction of each of the two annular members and configured to receive balls. The opposed surfaces are snap-fitted to each other to couple together the two annular members. The hemispherical pockets each have an inner peripheral surface provided with ball contact and ball non-contact surfaces. The ball contact surface is formed at a central portion in a pocket circumferential direction and at least at a central portion in a pocket axial direction of the inner peripheral surface. The ball non-contact surface includes a recess recessed to an opposite side to a corresponding ball across the ball contact surface and is opened in at least one of pocket axial ends.

Abstract: A retainer for a ball bearing includes two annular members that face each other in an axial direction thereof. The two annular members include opposed surfaces each having hemispherical pockets that are formed at positions in a circumferential direction of each of the two annular members and configured to receive balls. The opposed surfaces are snap-fitted to each other to couple together the two annular members. The hemispherical pockets each have an inner peripheral surface provided with ball contact and ball non-contact surfaces. The ball contact surface is formed at a central portion in a pocket circumferential direction and at least at a central portion in a pocket axial direction of the inner peripheral surface. The ball non-contact surface includes a recess recessed to an opposite side to a corresponding ball across the ball contact surface and is opened in at least one of pocket axial ends.

Abstract: A retainer for a ball bearing includes two annular members that face each other in an axial direction thereof. The two annular members include opposed surfaces each having hemispherical pockets that are formed at positions in a circumferential direction of each of the two annular members and configured to receive balls. The opposed surfaces are snap-fitted to each other to couple together the two annular members. The hemispherical pockets each have an inner peripheral surface provided with ball contact and ball non-contact surfaces. The ball contact surface is formed at a central portion in a pocket circumferential direction and at least at a central portion in a pocket axial direction of the inner peripheral surface. The ball non-contact surface includes a recess recessed to an opposite side to a corresponding ball across the ball contact surface and is opened in at least one of pocket axial ends.

Abstract: To provide a rubber composition capable of sufficiently abrading a sealing lip while sliding it in an initial stage of rotation and sufficiently reducing a running torque, and further capable of securing a sufficient sealing property. The composition includes a first compounding ingredient which is one or more kinds selected from the group consisting of calcium carbonate, magnesium oxide, aluminum oxide and barium sulfate in an amount of 50 to 200 parts by mass based on 100 parts by mass of a rubber component, and a second compounding ingredient which is one or two kinds selected from the group consisting of carbon black and a silica in an amount of more than 0 parts by mass and 50 parts by mass or lower.

Abstract: A retainer provides torque reduction. The retainer is formed by two annular retaining plates each including semispherical swelling portions arranged at predetermined intervals along a circumferential direction. The semispherical swelling portions face each other and form pockets for retaining balls. Each of the pockets has ball-facing surfaces each including a ball non-contact portion, and a contact area in each of the pockets with respect to each of the balls is reduced by from 15% to 30% by the ball non-contact portion. Each of the seal members serves as a contact seal having a seal lip portion coming into contact with another of raceway, and a material of at least a distal end of the seal lip portion includes a high-abrasion material which is prone to abrasion.

Abstract: A retainer for a ball bearing includes two annular members that face each other in an axial direction thereof. The two annular members include opposed surfaces each having hemispherical pockets that are formed at positions in a circumferential direction of each of the two annular members and configured to receive balls. The opposed surfaces are snap-fitted to each other to couple together the two annular members. The hemispherical pockets each have an inner peripheral surface provided with ball contact and ball non-contact surfaces. The ball contact surface is formed at a central portion in a pocket circumferential direction and at least at a central portion in a pocket axial direction of the inner peripheral surface. The ball non-contact surface includes a recess recessed to an opposite side to a corresponding ball across the ball contact surface and is opened in at least one of pocket axial ends.

Abstract: To provide a rubber composition capable of sufficiently abrading a sealing lip while sliding it in an initial stage of rotation and sufficiently reducing a running torque, and further capable of securing a sufficient sealing property. The composition includes a first compounding ingredient which is one or more kinds selected from the group consisting of calcium carbonate, magnesium oxide, aluminum oxide and barium sulfate in an amount of 50 to 200 parts by mass based on 100 parts by mass of a rubber component, and a second compounding ingredient which is one or two kinds selected from the group consisting of carbon black and a silica in an amount of more than 0 parts by mass and 50 parts by mass or lower.

Abstract: An object is to prevent premature peeling on the raceways due to hydrogen embrittlement using an inexpensive means. The inner and outer races 2 and 3 are made of high-carbon chrome bearing steel SUJ2, and is subjected to high-temperature tempering of 260° C. or higher, and the grease A contains a molybdate and an organic acid salt. With this arrangement, it is possible to prevent premature peeling on raceways 2a and 3a due to hydrogen embrittlement with such simple means as to slightly increase the tempering temperature and specify the composition of the grease A.

Abstract: Provided are a retainer capable of achieving torque reduction, a deep-groove ball bearing with the retainer, and a sealed bearing capable of preventing intrusion of foreign matter into the bearing and capable of sufficient seal torque reduction. The retainer is formed by combination of two annular retaining plates (27A, 27B) each including semispherical swelling portions (26) arranged at predetermined intervals along a circumferential direction. The semispherical swelling portions (26, 26) face each other and form pockets (30) for retaining balls (16). Each of the pockets (30) has ball-facing surfaces each including a ball non-contact portion (31), and a contact area in each of the pockets (30) with respect to each of the balls (16) is reduced by from 15% to 30% in comparison with a contact area with respect to each of the balls (16) without provision of the ball non-contact portion (31).