Abstract: A sensor unit is supported on a stationary ring which does not rotate even when it is in use, and the rotation of the rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, besides the rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby being able to detect the rotation speed and the rotation number of the wheel supported on the rotary ring, and the other car driving conditions.

Abstract: A linear-motion device has: a linear-motion element fitted on a shaft which moves straight along the shaft; a plurality of balls which are retained in a ball groove formed on the inner side of the linear-motion element and roll over between the ball groove and the shaft; a separator interposed between the balls; and, a circulating path formed in the linear-motion element through which the balls are circulated from one end of the ball groove to the other, which is filled with a grease, wherein the separator is a formed product comprising as a resin component a polybutylene naphthalate-based elastomer formed by a hard segment made of a polybutylene naphthalate and a soft segment made of a polycondensate of 2,6-naphthalanedicarboxylic acid with a polytetramethylene ether glycol.

Abstract: A sensor unit is supported on a stationary ring which does not rotate even when it is in use, and the rotation of the rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, besides the rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby being able to detect the rotation speed and the rotation number of the wheel supported on the rotary ring, and the other car driving conditions.

Abstract: A wheel rotation detecting device including a sensor unit that is supported on a stationary ring which does not rotate even when the wheel is in use, and the rotation of the wheel that is attached to a rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, in addition to a rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby allowing detection of the rotation speed and the rotation number of the wheel supported on the rotary ring, as well as detection of other car driving conditions.

Abstract: The frequencies generated based on the undulations existing on the inner and outer ring raceways 8, 10 and on the rolling surface of the balls 11, 11 are out of coincidence with the rotational frequency itself of the rotation member supported by the rolling bearing, and with a frequency component which is a multiple of the rotational frequency, or kinds of frequencies generated due to the undulations are out of coincidence with each other in the natural frequency domain of a rotation system which is a rotation supporting portion having the rolling bearing incorporated therein, whereby without using a special grease, the self-excited frequency of the rolling bodies hardly grows to abnormal vibration, and a rolling bearing having sufficient durability and causing no abnormal vibration and noise even if used at low temperature is realized.

Abstract: The pocket surface of a pocket with a ball stored therein has a pair of first pocket surfaces respectively formed inside a pair of pawls and a second pocket surface situated between the two first pocket surfaces. The second pocket surface is formed as a spherical-shaped concave surface having a radius of curvature the center of curvature of which is the rotation center of the ball in a no-load state. Each of the first pocket surfaces has a center of curvature shifted from the center of curvature of the second pocket surface toward the opposite side to the entrance (opening) of the pocket by an axially shifting quantity h1, and each of the first pocket surfaces is formed, starting from the present center of curvature, as a spherical-shaped concave surface with its radius of curvature set larger than the radius of curvature of the second pocket surface.

Abstract: The frequencies generated based on the undulations existing on the inner and outer ring raceways 8, 10 and on the rolling surface of the balls 11, 11 are out of coincidence with the rotational frequency itself of the rotation member supported by the rolling bearing, and with a frequency component which is a multiple of the rotational frequency, or kinds of frequencies generated due to the undulations are out of coincidence with each other in the natural frequency domain of a rotation system which is a rotation supporting portion having the rolling bearing incorporated therein, whereby without using a special grease, the self-excited frequency of the rolling bodies hardly grows to abnormal vibration, and a rolling bearing having sufficient durability and causing no abnormal vibration and noise even if used at low temperature is realized.

Abstract: A linear-motion device has: a linear-motion element fitted on a shaft which moves straight along the shaft; a plurality of balls which are retained in a ball groove formed on the inner side of the linear-motion element and roll over between the ball groove and the shaft; a separator interposed between the balls; and, a circulating path formed in the linear-motion element through which the balls are circulated from one end of the ball groove to the other, which is filled with a grease, wherein the separator is a formed product comprising as a resin component a polybutylene naphthalate-based elastomer formed by a hard segment made of a polybutylene naphthalate and a soft segment made of a polycondensate of 2,6-naphthalanedicarboxylic acid with a polytetramethylene ether glycol.

Abstract: The pocket surface of a pocket with a ball stored therein has a pair of first pocket surfaces respectively formed inside a pair of pawls and a second pocket surface situated between the two first pocket surfaces. The second pocket surface is formed as a spherical-shaped concave surface having a radius of curvature the center of curvature of which is the rotation center of the ball in a no-load state. Each of the first pocket surfaces has a center of curvature shifted from the center of curvature of the second pocket surface toward the opposite side to the entrance (opening) of the pocket by an axially shifting quantity h1, and each of the first pocket surfaces is formed, starting from the present center of curvature, as a spherical-shaped concave surface with its radius of curvature set larger than the radius of curvature of the second pocket surface.

Abstract: A sensor unit is supported on a stationary ring which does not rotate even when it is in use, and the rotation of the rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, besides the rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby being able to detect the rotation speed and the rotation number of the wheel supported on the rotary ring, and the other car driving conditions.

Abstract: In a rolling bearing including an inner race; an outer race; a plurality of rolling elements rollingly arranged between the inner race and the outer race; and a cage holding the rolling elements, the cage has an annular shape and a plurality of pockets which are formed at plural positions in a circumferential direction of the cage, in which each of the pockets has an opening peripheral portion which is curved to a direction of increasing a distance from a center of the rolling elements. The opening peripheral portion forms a chamfered face or a convex face. The rolling bearing can sufficiently ensure the lubrication of sliding contact portions between the cage and rolling elements so that vibrations and noises of the rolling bearing are lowered.

Abstract: A rolling bearing unit having undulation on the rolling surfaces of the rolling elements where the total value of the wave components having an even number of waves per circumference is smaller than the total value of the wave components having an odd number of waves per circumference, or having undulation on the inner ring raceway and outer ring raceway, where the undulation on at least one of the raceway is conditioned such that the maximum waviness amplitude among (nZ), (nZ+1) and (nZ -1) waves per circumference is smaller than the maximum waviness amplitude among (nZ+2) and more waves per circumference, where n is a positive integer and Z is the number of rolling elements, thereby making it possible to obtain a low-cost, high-performance rolling bearing in which the vibration characteristics of the rolling bearing are improved without having to increase the precision required for manufacturing the rolling elements and inner ring raceway and outer ring raceways.

Abstract: In order to reduce the sound pressure levels of abnormal sound called "squeal" and the sound of the cage that are produced during the operation of radial rolling bearings, the radial rolling bearing according to the present invention satisfies the following relations: 1.5.times.10.sup.-3 D.ltoreq.H.ltoreq.9.0.times.10.sup.-3 D and A/B=0.6-1.0, where D=diameter of the outer peripheral surface of cage 5a; H=thickness of annular gap 9 between the inner peripheral surface of flange 10 formed at an end portion of outer race 2a and the mating outer peripheral surface of the cage 5a; A=axial length of the outer peripheral surface of an end portion of the cage 5a; B=axial length of the mating inner peripheral surface of the flange 10.

Abstract: 1. A ball bearing comprising; a first race ring having a surface formed with a first race surface thereon, a second race ring having a surface formed with a second race surface thereon, and a plurality of balls provided so as to be freely rotatable between the first race surface and the second race surface, the ball bearing being used under conditions wherein a product d.sub.m .multidot.N of a pitch circle diameter d.sub.m mm of the plurality of balls, and a rotational speed N rpm of the second race ring relative to the first race ring is greater than 1,000,000 mm.multidot.rpm, characterized in that for each of the plurality of balls, a ratio .DELTA.I/I of a dynamic imbalance amount to a moment of inertia I, is less than (3.1.times.10.sup.7 /(d.sub.m .multidot.N).sup.2)+2.7.times.10.sup.-5.