Abstract: A retainer for a bearing is entirely formed into an annular shape and has a crown shape. The retainer includes pockets which are formed at a plurality of locations in a circumferential direction of the retainer and are each opened on a radially outer side and a radially inner side. The pockets retain balls being rolling elements so that the balls are rollable. A grease flow-in passage is provided between an inner surface of each of the plurality of pockets and each of the balls.

Abstract: It is an object of the present invention to provide a grease composition, for an outer ring rotation type rolling bearing, which is capable of satisfying all of high-temperature durability, low-temperature property, peeling resistance, and rust-preventive property. A grease composition (7) to be enclosed in the outer rig rotation type rolling bearing for use in automotive electric auxiliary machines contains base oil, a thickener, a peeling-resistant additive, a wear-resistant additive, and a rust-preventive agent. The base oil is mixed oil of trimellitic acid ester oil and synthetic hydrocarbon oil mixed therewith in a mass ratio of (70:30) to (90:10). The thickener consists of a diurea compound shown by a formula (1). R1—NHCONH—R2—NHCONH—R1??(1) wherein a reference symbol R2 denotes a divalent aromatic hydrocarbon group having a carbon number of 6 to 15, and a reference symbol R1 denotes a cyclohexyl group.

Abstract: A power transmission roller assembly includes a power transmission roller configured to be brought into contact with the driving roller and the driven roller, a pivot shaft fixed to a vehicle body, a pivot arm arranged radially inside of the power transmission roller and pivotally mounted on the pivot shaft, and a roller support bearing rotatably supporting the power transmission roller. A pair of biasing members are mounted to the pivot arm and bias the roller support bearing to a predetermined position between the driving roller and the driven roller such that the abutment force between the driving roller and the power transmission roller is balanced with the abutment force between the driven roller and the power transmission roller. Sliding members are mounted on respective shafts of the biasing members to extend through the sliding members, and frictional forces are generated between the sliding members and the respective shafts.

Abstract: A pressed pulley includes an annular connecting portion connected to an end of the outer tubular portion around which a belt is wound and an end of the inner tubular portion. The connecting portion is an annular bent portion having a circular arc-shaped section and formed with an inner circular arc-shaped surface having a constant radius of curvature and connected to the radially inner surface of the outer tubular portion and the radially outer surface of the inner tubular portion through respective tangential lines.

Abstract: The present invention relates to a retainer for a bearing. The retainer is entirely formed into an annular shape and has a crown shape. The retainer includes pockets (15c) which are formed at a plurality of locations in a circumferential direction of the retainer and are each opened on a radially outer side and a radially inner side. The pockets (15c) retain balls (14) being rolling elements so that the balls (14) are rollable. A grease flow-in passage (22) is provided between an inner surface (18) of each of the plurality of pockets and each of the balls.

Abstract: It is an object of the present invention to provide a grease composition, for an outer ring rotation type rolling bearing, which is capable of satisfying all of high-temperature durability, low-temperature property, peeling resistance, and rust-preventive property. A grease composition (7) to be enclosed in the outer rig rotation type rolling bearing for use in automotive electric auxiliary machines contains base oil, a thickener, a peeling-resistant additive, a wear-resistant additive, and a rust-preventive agent. The base oil is mixed oil of trimellitic acid ester oil and synthetic hydrocarbon oil mixed therewith in a mass ratio of (70:30) to (90:10). The thickener consists of a diurea compound shown by a formula (1). R1—NHCONH—R2—NHCONH—R1??(1) wherein a reference symbol R2 denotes a divalent aromatic hydrocarbon group having a carbon number of 6 to 15, and a reference symbol R1 denotes a cyclohexyl group.

Abstract: A power transmission roller assembly includes a power transmission roller configured to be brought into contact with the driving roller and the driven roller, a pivot shaft fixed to a vehicle body, a pivot arm arranged radially inside of the power transmission roller and pivotally mounted on the pivot shaft, and a roller support bearing rotatably supporting the power transmission roller. A pair of biasing members are mounted to the pivot arm and bias the roller support bearing to a predetermined position between the driving roller and the driven roller such that the abutment force between the driving roller and the power transmission roller is balanced with the abutment force between the driven roller and the power transmission roller. Sliding members are mounted on respective shafts of the biasing members to extend through the sliding members, and frictional forces are generated between the sliding members and the respective shafts.

Abstract: A power transmission roller assembly is provided which includes a roller body to be brought into abutment with the driving roller and the driven roller; a pivot shaft fixed to a vehicle body; a pivot arm provided radially inside of the roller body, and pivotally mounted on the pivot shaft; a roller support bearing rotatably supporting the roller body; and a pair of biasing members provided on the pivot arm. The pair of biasing members bias the roller support bearing to a predetermined position between the driving and driven rollers where the abutment forces between the roller body and the driving and driven rollers balance with each other.

Abstract: A rolling bearing includes inner and outer races rotatable relative to each other, a plurality of rolling elements interposed between the inner and outer races, and a retainer arranged between the inner and outer races for retaining the plurality of rolling elements equiangularly. Flange portions are formed on a radially inner side and a radially outer side of an axial end portion of the retainer so as to extend radially. Recessed grooves are formed in a region of the inner race and a region of the outer race corresponding to the respective flange portions so as to form labyrinths together with the flange portions. Inner side surfaces of the flange portions and axial end surfaces of the recessed grooves, which are opposed to the inner side surfaces of the flange portions, are inclined radially so as to generate a flow of lubricant.

Abstract: A pressed pulley is provided of which the inner diameter of an inner tubular portion can be increased without changing the outer diameter of an outer tubular portion. The pulley includes an annular connecting portion (13) connected to an end of the outer tubular portion (11) around which a belt is wound and an end of the inner tubular portion (12). The connecting portion is an annular bent portion having a circular arc-shaped section and formed with an inner circular arc-shaped surface (15) having a constant radius of curvature and connected to the radially inner surface of the outer tubular portion (11) and the radially outer surface of the inner tubular portion (12) through respective tangential lines.

Abstract: A rolling bearing includes inner and outer races rotatable relative to each other, a plurality of rolling elements interposed between the inner and outer races, and a retainer arranged between the inner and outer races for retaining the plurality of rolling elements equiangularly. Flange portions are formed on a radially inner side and a radially outer side of an axial end portion of the retainer so as to extend radially. Recessed grooves are formed in a region of the inner race and a region of the outer race corresponding to the respective flange portions so as to form labyrinths together with the flange portions. Inner side surfaces of the flange portions and axial end surfaces of the recessed grooves, which are opposed to the inner side surfaces of the flange portions, are inclined radially so as to generate a flow of lubricant.

Abstract: A plunger 4 and a spring 6 biasing the plunger 4 outwardly are mounted in a cylinder chamber 2 formed in a housing 1. The housing 1 is provided with an oil supply passage 8 communicating with a pressure chamber 7 formed in the back of the plunger 4. The housing 1 has an outer diameter that is substantially constant over the entire axial length, so that such housings can be mass-produced by pressing. It is thus possible to lower the cost of the chain tensioner.

Abstract: A chain tensioner includes a housing having a cylinder chamber. A plunger is slidably mounted in the cylinder chamber. A spring is mounted in the cylinder chamber to bias the plunger outwardly of the cylinder chamber. The plunger has a radially extending locking pin at its lower portion near its front end. The housing is formed with a pin hole extending substantially perpendicular to an axis of the cylinder chamber near the front end of the housing and under the cylinder chamber. The chain tensioner further includes a support pin inserted in the pin hole, and a locking lever supported on the support pin so as to be pivotable about the support pin. The locking lever can engage the locking pin when the plunger is sufficiently pushed into the cylinder chamber, thereby keeping the plunger pushed in the cylinder chamber.

Abstract: A chain tensioner is provided which can prevent separation of the plunger. In a cylinder chamber 12 of the housing 11, a plunger 13 and a spring 15 that biases the plunger 13 outwardly are mounted. The housing 11 is provided with an oil supply passage 17 communicating with a pressure chamber 16 formed in the cylinder chamber behind the plunger 13. An axially elongated guide recess 31 is formed in the outer periphery of the plunger 13. The housing 11 is provided with a stopper pin 33 near the open end of the cylinder chamber. By abutting the rear end wall 31b of the guide recess 31, the stopper pin 33 prevents separation of the plunger 13 from the housing.

Abstract: A hydraulic tensioner includes a cylinder having a hollow space filled with hydraulic oil. A plunger is slidably mounted in the cylinder. A pushrod is mounted in the hollow space so as to be axially movable together with the plunger with one end thereof protruding from the cylinder. A spring is mounted in the cylinder to bias the plunger and pushrod outwardly of the cylinder. The plunger is formed with a passage through which a pressure chamber and reservoir chamber communicate with each other. The passage is formed with a valve seat. A check ball is arranged so as to be moved into and out of contact with the valve seat. The check ball is adapted to contact the valve seat when pressure in the pressure chamber exceeds pressure in the reservoir chamber, thereby closing the passage. The valve seat is formed of a steel for carburizing and has a surface carbon concentration of 0.55–0.75% to reduce deposition of carbides and to have a surface hardness at least equal to that of the check ball.

Abstract: A chain tensioner includes a housing having a cylinder chamber. A plunger is slidably mounted in the cylinder chamber. A spring is mounted in the cylinder chamber to bias the plunger outwardly of the cylinder chamber. The plunger has a radially extending locking pin at its lower portion near its front end. The housing is formed with a pin hole extending substantially perpendicular to an axis of the cylinder chamber near the front end of the housing and under the cylinder chamber. The chain tensioner further includes a support pin inserted in the pin hole, and a locking lever supported on the support pin so as to be pivotable about the support pin. The locking lever can engage the locking pin when the plunger is sufficiently pushed into the cylinder chamber, thereby keeping the plunger pushed in the cylinder chamber.

Abstract: A plunger 4 and a spring 6 biasing the plunger 4 outwardly are mounted in a cylinder chamber 2 formed in a housing 1. The housing 1 is provided with an oil supply passage 8 communicating with a pressure chamber 7 formed in the back of the plunger 4. The housing 1 has an outer diameter that is substantially constant over the entire axial length, so that such housings can be mass-produced by pressing. It is thus possible to lower the cost of the chain tensioner.

Abstract: It is desired to improve the wear resistance of the valve seat of the check valve in a hydraulic tensioner. The hydraulic tensioner includes a cylinder having a hollow space filled with hydraulic oil. A plunger is slidably mounted in the cylinder. A pushrod is mounted in the hollow space so as to be axially movable together with the plunger with one end thereof protruding from the cylinder. A spring is mounted in the cylinder to bias the plunger and pushrod outwardly of the cylinder. The plunger is formed with a passage through which the pressure chamber and the reservoir chamber communicate with each other. The passage is formed with a valve seat. A check ball is arranged so as to be moved into and out of contact with the valve seat. The check ball is adapted to contact the valve seat when the pressure in the pressure chamber exceeds the pressure in the reservoir chamber, thereby closing the passage. The valve seat is formed of a steel for carburizing and has a surface carbon concentration of 0.55-0.

Abstract: An autotensioner which is of more compact structure and can be mounted in a limited space. The autotensioner has a fixed member, an arm pivotally mounted on the fixed member, a pulley support shaft mounted on the arm, a pulley rotatably mounted on the pulley support shaft, a cylinder having a damper mounted therein and mounted on the arm, the arm being pivotable about an axis and both the pulley support shaft and the cylinder being mounted on the arm at positions offset from the axis, the damper having a rod mounted in the cylinder so as to be pushed out of and into the cylinder, and a stopper fixed to the fixed member, the rod being kept in contact with the stopper.

Abstract: A hydraulic autotensioner having a close-bottomed body in which is sealed hydraulic oil. A plunger is slidably mounted in the body with a gap formed therebetween through which the hydraulic oil can leak. The plunger is formed with a hole in the top thereof, and a return passage extending through the plunger from the bottom of the hole to the bottom of the plunger. A rod, having its bottom end inserted in the hole, is provided with a rod spring for biasing the rod in such a direction so as to protrude out of the body. A plunger spring is provided for urging the plunger against the bottom end of the rod. Also, a valve seat is provided on the bottom of the hole so as to be brought into close contact with the bottom end of the rod. The return passage is opened and closed by axial displacement of the rod relative to the valve seat.