Abstract: When an inner race 12 rotates at a speed lower than a predetermined speed, a sealing body 27 contacts the sealing face part 21c, but when the inner race 12 rotates at a speed more than the predetermined speed, a contacting pressure to a sealing face part 21c is reduced or the sealing body 27 is isolated so as to form a non-contacting seal, and therefore, for example, at the low speed, the sealing body 27 forms a contacting seal, thereby to compensate a low speed-low sealing ability of the non-contacting seal such as the labyrinth seal, and on the other hand, at high speed rotation, the sealing body 27 reduces the contacting pressure to the sealing face part 21c, otherwise separates therefrom to form the non-contacting seal as the labyrinth seal, whereby it is possible to solve the problem of heating or abrasion at the contacting part.

Abstract: When an inner race (12) rotates at a speed lower than a predetermined speed, a sealing body (27) contacts the sealingface part (21c), but when the inner race (12) rotates at a speed more than the predetermined speed, a contacting pressure to a sealing face part (21c) is reduced or the sealing body (27) is isolated so as to form a non-contacting seal, and therefore, for example, at the low speed, the sealing body (27) forms a contacting seal, thereby to compensate a low speed-low sealing ability of the non-contacting seal such as the labyrinth seal, and on the other hand, at high speed rotation, the sealing body (27) reduces the contacting pressure to the sealing face part (21c), and otherwise separates therefrom to form the non-contacting seal as the labyrinth seal, whereby it is possible to solve the problem of heating or abrasion at the contacting part.

Abstract: A sealed rolling bearing in which a rolling member is disposed in a bearing space formed between an outer race and an inner race to rotate the outer race and the inner race relatively to each other, and rotation seal members are disposed at both ends of the bearing space in the axial direction thereof while a stationary seal member is disposed on the side of the inner race, thereby sealing the bearing space. The bearing is provided with a vent on the side of the inner race for approximating a fluid pressure in the bearing space to an outside fluid pressure by causing the inside of the bearing space to communicate with the outside when the state of fluid in the bearing space and state of the outside fluid have a predetermined relationship.

Abstract: A sealed rolling bearing in which a rolling member is disposed in a bearing space formed between an outer race and an inner race to rotate the outer race and the inner race relatively to each other, and rotation seal members are disposed at the both ends of the bearing space in the axial direction thereof while a stationary seal member is disposed on the side of the inner race, thereby sealing the bearing space. The bearing is provided with vent means on the side of the inner race for approximating a fluid pressure in the bearing space to an outside fluid pressure by causing the inside of the bearing space to communicate with the outer when the state of the fluid in the bearing space and state of the outside fluid become a predetermined relationship.

Abstract: To provide a ball bearing that insures reasonable endurance and which reduces the necessary torque for rotation while causing less fluctuations in torque, a synthetic resin cage of the ball bearing for retaining a plurality of balls so as to roll freely is impregnated with a lubricating oil having a viscosity of 10 to 150 mm.sup.2 /s at 40.degree. C. in an amount of 0.1 to 1.0% by weight of the cage, a film of the lubricating oil is formed in a thickness of 0.03 to 20 .mu.m on the surfaces of an inner race, an outer race, balls and the cage, and the amounts of the oiliness agent and the rust inhibitor that are to be contained in the lubricating oils are limited to the specified ranges.

Abstract: To provide a ball bearing that insures reasonable endurance and which reduces the necessary torque for rotation while causing less fluctuations in torque, a synthetic resin cage of the ball bearing for retaining a plurality of balls so as to roll freely is impregnated with a lubricating oil having a viscosity of 10 to 150 mm.sup.2 /s at 40.degree. C. in an amount of 0.1 to 1.0% by weight of the cage, a film of the lubricating oil is formed in a thickness of 0.03 to 20 .mu.m on the surfaces of an inner race, an outer race, balls and the cage, and the amounts of the oiliness agent and the rust inhibitor that are to be contained in the lubricating oils are limited to the specified ranges.