Abstract: A die-casting sleeve comprising an outer cylinder made of a low-thermal-expansion metal material, and an inner cylinder shrink-fit into the outer cylinder; an outer peripheral surface of the outer cylinder being provided with a flange for fixing the die-casting sleeve to a stationary die block of a die-casting machine; the inner cylinder being constituted by a front member of a low-thermal-expansion metal material arranged on the injection opening side, and a rear member of silicon-nitride-based ceramics arranged in close contact with a rear end surface of the front member; the outer cylinder having an average thermal expansion coefficient ?A of 1×10?6/° C. to 5×10?6/° C. between 20° C. and 200° C.; the front member having an average thermal expansion coefficient ?B of 1×10?6/° C. to 5×10?6/° C. between 20° C. and 200° C.; the difference between ?A and ?B being ?1×10?6/° C. to 1×10?6/° C.

Abstract: A die-casting sleeve comprising an outer cylinder made of a low-thermal-expansion metal material, and an inner cylinder shrink-fit into the outer cylinder; an outer peripheral surface of the outer cylinder being provided with a flange for fixing the die-casting sleeve to a stationary die block of a die-casting machine; the inner cylinder being constituted by a front member of a low-thermal-expansion metal material arranged on the injection opening side, and a rear member of silicon-nitride-based ceramics arranged in close contact with a rear end surface of the front member; the outer cylinder having an average thermal expansion coefficient ?A of 1×10?6/° C. to 5×10?6/° C. between 20° C. and 200° C.; the front member having an average thermal expansion coefficient ?B of 1×10?6/° C. to 5×10?6/° C. between 20° C. and 200° C.; the difference between ?A and ?B being ?1×10?6/° C. to 1×10?6/° C.

Abstract: A roll for a hot-dip metal coating bath has a substantially cylindrical shape. At least an outer peripheral surface of the roll is formed of a ceramic material. A relatively coarse groove is formed on the outer peripheral surface of the roll in a direction crossing the rotation axis. A plurality of relatively fine grooves is formed in the bottom surface of the coarse groove along the longitudinal direction of the coarse groove. In place of the fine grooves extending in the longitudinal direction of the coarse groove, a plurality of rows of fine grooves may be formed along the crosswise direction of the coarse groove.

Abstract: A bearing rotatably supporting a shaft of a rotating body immersed in a molten-metal-plating bath, comprising at least two partially cylindrical ceramic bearing members each having a sliding surface coming into sliding contact with the shaft and end surfaces directly or indirectly connected to the sliding surface; and a holding member comprising a movement-restricting member arranged with a recess, in which at least two bearing members being circumferentially arranged with their one-side end surfaces opposing via a gap, the movement-restricting member abutting the other-side end surfaces of the bearing members for restricting the circumferential movement of the bearing members; at least one bearing member being circumferentially movable to or away from the other bearing member or members in at least two bearing members, such that the one-side end surfaces opposing via the gap come into contact or are separated from each other.

Abstract: A bearing rotatably supporting a shaft of a rotating body immersed in a molten-metal-plating bath, comprising at least two partially cylindrical ceramic bearing members each having a sliding surface coming into sliding contact with the shaft and end surfaces directly or indirectly connected to the sliding surface; and a holding member comprising a movement-restricting member arranged with a recess, in which at least two bearing members being circumferentially arranged with their one-side end surfaces opposing via a gap, the movement-restricting member abutting the other-side end surfaces of the bearing members for restricting the circumferential movement of the bearing members; at least one bearing member being circumferentially movable to or away from the other bearing member or members in at least two bearing members, such that the one-side end surfaces opposing via the gap come into contact or are separated from each other.

Abstract: It is an object of the present invention to provide a rotor and a method for manufacturing the same that represent an improvement over the prior art. A roll for hot-dip metal coating bath having a body with a substantially cylindrical appearance, at least an outer peripheral surface thereof being formed of a ceramic material, wherein, on the outer peripheral surface of the body, a groove formed in a direction crossing the rotation axis is formed, and in the bottom surface of the groove, a plurality of rows of a fine groove is formed along the longitudinal direction of the groove. In place of the fine groove along the longitudinal direction of the groove, a plurality of rows of a fine groove are formed along the crosswise direction of the groove.