The resin injection gate is disposed at the pillar part. When the bearing cage is divided into first and second regions by an imaginary line connecting the resin injection gate and a weld to be formed at a position radially facing the resin injection gate, a resin reservoir that can store therein the melted resin is formed at the pillar part in only one of the regions. A circumferential distance between the resin reservoir and the weld is smaller than a circumferential distance between the resin reservoir and the resin injection gate. A cross-sectional area of a communicating part of the resin reservoir, which is configured to communicate with the pillar part, is equal to or less than a quarter of a cross-sectional area of the resin injection gate.

Oil grooves (40) formed in at least one of surfaces of a ring-shaped member (30) each have a longitudinal direction that forms an angle falling within a range of from 40 degrees to 75 degrees with respect to a radial direction of the ring-shaped member, and are arranged at equal intervals in a circumferential direction of the ring-shaped member (30). The oil grooves (40) include communicating oil grooves (40A) and non-communicating oil grooves (40B) formed to extend to the vicinity of an outer peripheral end (34), and are arranged with periodic regularity in the circumferential direction of the ring-shaped member (30). In addition, a communicating oil groove area ratio expressed by Expression: “S1/(S1+S2)” falls within a range of from 0.15 to 0.85, where S1 represents a sum of plane areas of the communicating oil grooves (40A), S2 represents a sum of the non-communicating oil grooves (40B).

Oil grooves (40) formed in at least one of surfaces of a ring-shaped member (30) each have a longitudinal direction that forms an angle falling within a range of from 40 degrees to 75 degrees with respect to a radial direction of the ring-shaped member, and are arranged at equal intervals in a circumferential direction of the ring-shaped member (30). The oil grooves (40) include communicating oil grooves (40A) and non-communicating oil grooves (40B) formed to extend to the vicinity of an outer peripheral end (34), and are arranged with periodic regularity in the circumferential direction of the ring-shaped member (30). In addition, a communicating oil groove area ratio expressed by Expression: “S1/(S1+S2)” falls within a range of from 0.15 to 0.85, where S1 represents a sum of plane areas of the communicating oil grooves (40A), S2 represents a sum of the non-communicating oil grooves (40B).

Provided is a sliding member for a journal bearing. The sliding member includes a back-metal layer and a sliding layer, and has a partially cylindrical shape. The sliding layer includes a synthetic resin and has a sliding surface. The sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a center axis direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface, and the linear expansion coefficients KS, KJ, and KT satisfy the following relations (1) and (2): Relation (1): 1.1≤KS/KJ≤2; and Relation (2): 1.3≤KT/{(KS+KJ)/2}≤2.5.

Provided is a sliding member for a thrust bearing. The sliding member includes a back-metal layer and a sliding layer, and has a partially annular shape. The sliding layer includes a synthetic resin and has a sliding surface. In a center line region of the sliding layer, the sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a radial direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface, and the linear expansion coefficients KS, KJ, and KT satisfy the following relations (1) and (2): Relation (1): 1.1≤KS/KJ≤2; and Relation (2): 1.3≤KT/{(KS+KJ)/2}≤2.5.

Provided is a resin bush capable of slidably supporting a shaft when the bush has been fitted in a housing; particularly, a resin bush suitable for use in an environment in which the effects of a difference in thermal expansion coefficients are likely to be prominent, such as a high-temperature environment, even when the housing and the shaft are made of a material such as a metal that has a different thermal expansion coefficient from that of the resin bush. In the resin bush (1), which is molded by extrusion molding, a slit (12) is formed from one axial end surface (11a) towards another axial end surface (11b). A recessed section (13) for a gate (a gate position), which is provided to the one axial end surface (11a), is provided in a position that is deviated from being symmetrical with the slit (12), at least with respect to a center axis O of a bush body (10). The resin used for the material of the bush (1) is a resin having excellent heat resistance and chemical resistance, such as PPS resin or a PEEK resin.

Provided is a sliding member for a journal bearing. The sliding member includes a back-metal layer and a sliding layer, and has a partially cylindrical shape. The sliding layer includes a synthetic resin and has a sliding surface. The sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a center axis direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface, and the linear expansion coefficients KS, KJ, and KT satisfy the following relations (1) and (2): Relation (1): 1.1≤KS/KJ≤2; and Relation (2): 1.3≤KT/{(KS+KJ)/2}≤2.5.

Provided is a sliding member for a thrust bearing. The sliding member includes a back-metal layer and a sliding layer, and has a partially annular shape. The sliding layer includes a synthetic resin and has a sliding surface. In a center line region of the sliding layer, the sliding layer has a linear expansion coefficient KS in a direction parallel to a circumferential direction of the sliding member, a linear expansion coefficient KJ in a direction parallel to a radial direction of the sliding member, and a linear expansion coefficient KT in a direction perpendicular to the sliding surface, and the linear expansion coefficients KS, KJ, and KT satisfy the following relations (1) and (2): Relation (1): 1.1≤KS/KJ≤2; and Relation (2): 1.3≤KT/{(KS+KJ)/2}≤2.5.

A ball joint has a ball stud, a housing and a ball seat. The seat is an elastic body in a tubular shape with the top and the bottom being open, and has a spherical space to accommodate a ball portion. The housing has a spherical inner face that is close to an outer periphery of the ball portion, to accommodate the ball portion in the inner face via the seat so as to support the ball stud. A clamped portion arranged at a peripheral end of the housing is clamped to press the seat so that the ball stud can be swung and rotated.

A drive device comprises at least one tubular linear motor (M1; M1; M2) which has a cylindrical armature (20; 120) and a tubular stator (10) with a cylindrical magnetic yoke (11) and a through-hole (13) coaxial with the magnetic yoke (11). Electric drive coils (12; 112) are arranged in the magnetic yoke (11). The armature (20; 120) has a non-magnetic armature tube (21) in which permanent magnets (23) are arranged. The armature (20; 120) extends coaxially through the through-hole (13) and is mounted so as to be movable in its longitudinal direction relative to the stator (10). The drive device comprises linear ball bearings (15; 115), and the armature (20; 120) of the tubular linear motor (M1; M1; M2) is mounted in the linear ball bearings (15; 115).