A charging roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The average of heights of contours of convex portions on a surface of the surface layer relative to an average cylindrical surface obtained by averaging surface irregularities of the surface layer is equal to or greater than 2.0 micrometers and is equal to or less than 8.4 micrometers. The average of intervals between apexes of the convex portions on the surface of the surface layer is equal to or greater than 6.7 micrometers and is equal to or less than 39.8 micrometers.

A bearing unit for a marble cutting machine, comprising a radially outer ring, rotatable about an axis of rotation (X) of the bearing unit and provided with a radially outer flange portion; a stationary radially inner ring having a raceway and a through hole; a row of rolling bodies interposed between the radially outer ring and the radially inner ring; a seat formed in the radially inner ring and shaped as a portion of a circular crown; and a sensor fit in the seat, wherein a ratio between an internal diameter (D) of the through hole and an axial thickness (t) of the radially inner ring is between 6.7 and 11.1.

A bearing unit for a marble cutting machine has a radially outer ring, rotatable with respect to an axis of rotation (X) and is provided with a radially outer flange portion. Additionally, the bearing unit is provided with a stationary radially inner ring with a through hole in which the ratio between a dimension of an internal diameter (D) of the through hole and a dimension of the axial thickness (T) of the radially inner ring is between about 6.7 and about 11.1. A row of rolling bodies is interposed between the radially outer ring and the radially inner ring. A sealing shield is made of composite material and interposed between the radially inner ring and the radially outer ring, rotatable with respect to the rotation axis (X) and steadily anchored to the radially outer ring. The shield is provided with a sensor molded in it.

An actuator is equipped with a body and a slider. Body side rail grooves are formed in side wall portions that constitute the body. On the other hand, slider side rail grooves are formed in the slider. Body side guide rails and slider side guide rails are provided in the body side rail grooves and the slider side rail grooves, respectively. Circular arc grooves serving as ball grooves are formed by body side ball receiving portions of the body side guide rails, and slider side ball receiving portions of the slider side guide rails.

A motion guide apparatus is provided which can prevent a ball from contacting an edge of a ball rolling groove of a track member when the ball transfers from a rolling surface of the inner peripheral side of a turn-around path (an inner peripheral-side component) to the track member. The motion guide apparatus includes: a track member (2) including a ball rolling groove (2a); and a moving member assembled to the track member (2) in such a manner as to be movable relative to the track member (2). The moving member includes: a moving member body having a loaded ball rolling groove facing the ball rolling groove (2a), and a return path substantially parallel to the loaded ball rolling groove; and a lid member having a turn-around path. In cross section of the motion guide apparatus perpendicular to a length direction of the track member (2), letting the radius of curvature of the ball rolling groove (2a) be R, and letting the distance from a ball center (O) to a rolling surface (21) of the inner peripheral side of the turn-around path (an inner peripheral-side component (9a)) be r, R>r is set.

A wheel hub assembly includes inner and outer hubs rotatably coupled by first and second ballsets of rollers. A plurality of sensors for sensing strain within the outer hub generated by the ballsets are disposed on exterior mounting surface sections. These surface sections are located at radial spacing distances within empirically derived radial boundaries to prevent interference from one ballset affecting the measurements taken by sensors monitoring the other ballset. To prevent excessive distortion of strain measurements taken through the outer hub, a certain amount of hub material is required to smooth signals generated by the first and second rollers passing proximal to each sensor, thus affecting the radial location of the mounting surfaces. Further, the sensor mounting surface sections are also located within empirically derived axial boundaries determined to enable each sensor to sense strain from one ballset while avoiding the detection of strain generated by the other ballset.

A synthetic resin retainer includes two annular members having opposed surfaces opposed to each other and each formed with a plurality of pockets which are circumferentially spaced apart from each other, and in which the balls are received. Each annular member includes axially concave, arc-shaped pocket wall portions defining the inner surfaces of the pockets, and flat plate-shaped coupling plate portions coupling together the adjacent pairs of the pocket wall portions. The coupling plate portions have axial thicknesses of 30% or less of the diameters of the balls, and the pocket wall portions have, at deepest points of the pockets, thicknesses of 10% or less of the diameters of the balls.

A torque converter comprising: an axis of rotation; a stator including a side plate having a first radial surface; one of an impeller shell or a turbine shell having a second tapered surface facing the stator side plate first radial surface; a hydrodynamic thrust bearing disposed between the stator side plate and the one of an impeller shell or a turbine shell, and comprising: a thrust surface facing one of the first radial surface or the second tapered surface with a fluid pathway therebetween; a supporting surface opposite the thrust surface and facing the other of the first radial surface or the second tapered surface; and an opening concentric with the axis of rotation; and, a gap between the supporting surface and the other of the first radial surface or the second tapered surface such that the bearing thrust surface is alignable to be parallel with the one of the first radial surface or the second tapered surface.

A thrust washer is provided with a ring-shaped portion that surrounds an insertion hole, the thrust washer is provided with a sliding surface and an oil groove configured to allow lubricating oil to flow in, the oil groove is provided with an opening portion configured to allow the lubricating oil to flow in from the insertion hole side in an inner peripheral end side, an outer periphery end side of the ring-shaped portion of at least one of the oil groove is provided with an oil stop wall which is configured to suppress flow of the lubricating oil toward an outer periphery side of the ring-shaped portion, and a sliding area ratio of each of the sliding surfaces to a projection plane in plan view of the ring-shaped portion is provided within a range of from 60% to 85%

Provided is a motion guide device including a track rail in which a rolling body rolling groove is formed and a movable block which is mounted on the track rail via a plurality of rolling bodies. The movable block includes a movable block body which has a loaded rotting body rolling groove forming a loaded rolling body rolling passage in cooperation with the rolling body rolling groove and has a non-loaded rolling body rolling passage, return members in which inner peripheral-side direction change grooves connecting the loaded rolling body rolling passage and the non-loaded rolling body rolling passage are formed, and end plates. The end plate has a rolling body scooping aim protruding in a direction of a connection surface with the movable block body and a rolling body scooping groove continuous with the outer peripheral-side direction change groove is formed in the rolling body scooping arm.