Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A bearing device comprising a shaft, a housing, a double row of bearings provided between the shaft and the housing and preloaded by a fixed-position preloading method, the double row of bearings having a pair of races with a gap therebetween for preload adjustment, and the bearing device further having a support member for supporting one side of the races in the pre-loading direction, and the support member provided on the side of one of the shaft and the housing.

Abstract: A bearing device comprising a shaft, a housing, a double row of bearings provided between the shaft and the housing and preloaded by a fixed-position preloading method, the double row of bearings having a pair of races with a gap therebetween for preload adjustment, and the bearing device further having a support member for supporting one side of the races in the pre-loading direction, and the support member provided on the side of one of the shaft and the housing.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A ball bearing comprises an inner ring, an outer ring and a plurality of balls disposed between inner and outer rings. The number of the balls is made to be not smaller than 10. Lubricant is also enclosed between the inner and outer rings in such a manner that the amount of the lubricant is regulated not more than 8% of the volume of a space between the inner and outer rings.

Abstract: A lubricating grease composition having a basic grease composition containing a synthetic oil as a base oil, and a lithium soap as a thickener. 0.5 to 10% by weight with respect to the basic grease composition total amount of at least one additive selected from the group consisting of an organic molybdenum compound, an organic fatty acid compound or an derivative thereof, and an organic phosphorus compound is added is provided. Accordingly, the present invention can provide a lubricating grease composition capable of providing excellent lubricating characteristics, fretting wear resistance property, and impact resistance property.

Abstract: In the ball bearing, the ratio of the radius of curvature of an inner race raceway 4 to the outside diameter of balls 8, 8 is set in the range of 0.51 to 0.54. Also, the ratio of the radius of curvature of an outer race raceway 6 to the outside diameter of balls 8, 8 is set in the range of 0.54 to 0.56. Further, an interior geometric clearance c is set at 13 &mgr;m or less. Thanks to these specifications, the balls 8, 8 can be prevented from running up onto the edge of the outer race raceway 6.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: In the ball bearing, the ratio of the radius of curvature of an inner race raceway 4 to the outside diameter of balls 8, 8 is set in the range of 0.51 to 0.54. Also, the ratio of the radius of curvature of an outer race raceway 6 to the outside diameter of balls 8, 8 is set in the range of 0.54 to 0.56. Further, an interior geometric clearance c is set at 13 &mgr;m or less. Thanks to these specifications, the balls 8, 8 can be prevented from running up onto the edge of the outer race raceway 6.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second innor raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second ir raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring In the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A lubricating grease composition having a basic grease composition containing a synthetic oil as a base oil, and a lithium soap as a thickener. 0.5 to 10% by weight with respect to the basic grease composition total amount of at least one additive selected from the group consisting of an organic molybdenum compound, an organic fatty acid compound or an derivative thereof, and an organic phosphorus compound is added is provided. Accordingly, the present invention can provide a lubricating grease composition capable of providing excellent lubricating characteristics, fretting wear resistance property, and impact resistance property.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A bearing device comprising a shaft, a housing, a double row of bearings provided between the shaft and the housing and preloaded by a fixed-position preloading method, the double row of bearings having a pair of races with a gap therebetween for preload adjustment, and the bearing device further having a support member for supporting one side of the races in the pre-loading direction, and the support member provided on the side of one of the shaft and the housing.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A rolling bearing having a plurality of rolling elements interposed between an inner race and an outer race, wherein the number of the rolling elements is selected to be equal to a number having, as divisors, main low-frequency peak components of geometrical error of the inner and outer races to be assembled.

Abstract: An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater then a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Abstract: A preload-adjustable bearing is constructed of a first rotary unit and second rotary unit. The first rotary unit has a first race and second race arranged immobile in a direction approaching toward each other. The second rotary unit has a third race and fourth race. The third race is located opposite the first race while the fourth race is located opposite the second race. The third race is fixed relative to the second rotary unit in a direction away from the fourth race. The fourth race is fitted with the second rotary unit with an interference formed therebetween movably relative to the second rotary unit. The fourth race is movable toward the third race under axial pressure applied between the fourth race and the second rotary unit.