39results about How to "Reduce shear resistance" patented technology

Provided are a retainer achieving low torque, a deep groove ball bearing using the retainer, and a bearing equipped with a seal, capable of preventing entry of foreign matter into the bearing and having sufficiently reduced seal torque. The retainer is formed by combining two annular holding plates (27A, 27B) each having hemispherical protrusions (26) circumferentially arranged at predetermined intervals. Pockets (30) for retaining balls (16) are formed by opposed hemispherical protrusions (26, 26). Contactless sections (31) with which a ball (16) does not make contact are formed on those surfaces of each pocket (30) which face the ball. The area of contact of each pocket (30) with the ball (16) is set less by 15% to 30% than the area of contact of the pocket (30) with the ball (16) when the contactless sections (31) are not provided. A seal member (17) is a contact seal in which a seal lip (17a) makes contact with the other raceway ring. The material of at least the front end of the seal lip (17a) is an easily wearable high wear material.

In the present invention, movement of a fluid from an upstream cavitation region to a downstream positive pressure generation region is smoothened, a negative pressure generation origin is enlarged, and cavitation regions are disposed over almost the whole circumference of a low-pressure fluid side. The present invention is characterized in that: dimples (10) are formed along a circumferential direction at an approximately constant width from an upstream cavitation formation region (10a) to a downstream positive pressure generation region (10b); an upstream starting end (10e) of the cavitation formation region (10a) forms a tapered shape inclined along the rotational direction of an opposing sliding surface from the low-pressure fluid side toward a high-pressure fluid side, and is disposed so as to overlap in the radial direction with the positive pressure generation region (10b) of the dimple (10) that is disposed upstream; and the low-pressure fluid-side end (10f) of the positive pressure generation region (10b) forms a tapered shape inclined along the rotational direction of the opposing sliding surface from the low-pressure fluid side toward the high-pressure fluid side, and is smoothly connected to the low-pressure fluid-side end (10c) of the cavitation formation region (10a).

A retainer of a tapered roller bearing includes crossbars having guide surfaces which circumferentially contact the tapered rollers. The crossbars are also formed with first recessed surfaces and second recessed surfaces which are both in the form of cutouts circumferentially recessed from the respective guide surfaces to reduce stirring resistance and shear resistance of oil. To reduce the contact lengths between the rolling surface central portions of the tapered rollers and the guide surfaces, the guide surfaces are smoothly convex in the longitudinal direction of the tapered rollers.

Provided is an oil ring (13) for a piston assembly that can minimize the frictional resistance without impairing the oil control function such as the scraping of lubricating oil from the cylinder wall surface by the oil ring. The oil ring consists of an upper side rail (16), a lower side rail (17) and an annular expander (18) interposed between the two side rails, and is received in an oil ring groove (8) with a prescribed vertical clearance (20) that permits tilting of the side rails. An outer peripheral surface (16E, 17E) of each side rail is provided with a radially inward slant. Therefore, during the upward stroke of the piston, the upper side rail tilts in the radially outward direction so that the effective slant angle of the outer peripheral surface of the upper side ring is adjusted to an optimum value.

A ball bearing includes an inner ring having an outer periphery in which an inner raceway groove is formed, an outer ring having an inner periphery in which an outer raceway groove is formed, a plurality of balls interposed between the inner raceway groove and the outer raceway groove, and an annular cage that holds the balls. The cage includes an annular portion positioned on one side in an axial direction with respect to the balls and a plurality of cage bar portions that extends from the annular portion toward the other side in the axial direction. Each cage bar portion has a guide portion, and this guide portion positions the cage by coming into contact with the outer raceway groove at one location in a non-contact area other than an area in which the corresponding ball is in contact with the outer raceway groove.

The invention discloses a coke cutter which comprises a rack, a motor, a gearbox, a coke cutting box, a bearing pedestal set, a master coke cutting roller and a slave coke cutting roller. The motor, the gearbox, the coke cutting box and the bearing pedestal set are arranged on the rack. The master coke cutting roller and the slave coke cutting roller are arranged in the coke cutting box in parallel through the bearing pedestal set. The motor is in transmission connection with the gearbox, and an output shaft of the gearbox is in transmission connection with the master coke cutting roller. The master coke cutting roller and the slave coke cutting roller each comprise a roller shaft, a plurality of pull rods, a roller shaft sleeve arranged on the roller shaft through an end sleeve, a plurality of gear rings arranged on the roller shaft sleeve, spacer rings arranged at the positions, between the adjacent gear rings, of the roller shaft sleeve, and end discs arranged at the positions, on the outer sides of the gear rings at the two ends, of the roller shaft sleeve. The end discs, the gear rings and the spacer rings are in fastened connection through the pull rods and pull rod nuts. Each gear ring comprises a disc-shaped gear ring disc body and a plurality of main cutter teeth evenly distributed on the periphery of the gear ring disc body. Slope faces are formed on three sides of the main side face of each main cutter tooth, and the contact position of every two adjacent slope faces is of a corner angle structure. The gear rings of the master coke cutting roller and the gear rings of the slave coke cutting roller are staggered, and the coke cutter is good in coke cutting quality.