A method for producing a sintered component, in particular an annular sintered component, with a toothing, having teeth with tooth roots, tooth tips and tooth flanks, includes the steps of pressing a powder to form a green compact, sintering the green compact, and hardening the sintered component, wherein after sintering, the tooth flanks and possibly the tooth tips are post-compacted and subsequently undergo post-processing by machining, and wherein a transition region between the tooth flanks and the tooth roots has an undercut design, and post-compaction of the tooth flanks is carried out only up to this transition region.

A resin gear includes an annular metal bush, an annular resin member provided around the metal bush and having a tooth profile formed in an outer peripheral portion, and an elastic member provided between the metal bush and the resin member. The elastic member has a first overhanging portion overhanging one end surface of the metal bush and one end surface of the resin member outward in an axial direction of the resin gear.

A resin gear includes an annular metal bush, an annular resin member provided around the metal bush and having a tooth profile formed in an outer peripheral portion, and an elastic member provided between the metal bush and the resin member. The elastic member has a first overhanging portion overhanging one end surface of the metal bush and one end surface of the resin member outward in an axial direction of the resin gear.

A resin gear includes an annular metal bush and an annular resin member provided around the metal bush. The metal bush and the resin member are disposed so as to be relatively rotatable in a direction of rotation of the resin gear. A plurality of spaces entering an outer peripheral surface of the metal bush and an inner peripheral surface of the resin member are formed, so as to be aligned along the direction of rotation, between the metal bush and the resin member. The space has, in at least one end portion in an axial direction of the resin gear, inner surfaces intersecting with the axial direction. An elastic member is disposed in the space. The elastic member engages with the inner surfaces.

A resin gear includes an annular metal bush and an annular resin member provided around the metal bush. The metal bush and the resin member are disposed so as to be relatively rotatable in a direction of rotation of the resin gear. A plurality of spaces entering an outer peripheral surface of the metal bush and an inner peripheral surface of the resin member are formed, so as to be aligned along the direction of rotation, between the metal bush and the resin member. The space has, in at least one end portion in an axial direction of the resin gear, inner surfaces intersecting with the axial direction. An elastic member is disposed in the space. The elastic member engages with the inner surfaces.

A gear includes: an outer circumferential rim provided integrally with a plurality of tooth portions disposed side-by-side in a circumferential direction on an outer circumferential surface; and a plurality of reinforcing ribs disposed inside the outer circumferential rim to be spaced from each other in the circumferential direction by thinning portions, wherein a position where each of the plurality of reinforcing ribs and the outer circumferential rim are joined corresponds, in the circumferential direction, to a position of a tooth groove between the plurality of tooth portions.

A gear includes: an outer circumferential rim provided integrally with a plurality of tooth portions disposed side-by-side in a circumferential direction on an outer circumferential surface; and a plurality of reinforcing ribs disposed inside the outer circumferential rim to be spaced from each other in the circumferential direction by thinning portions, wherein a position where each of the plurality of reinforcing ribs and the outer circumferential rim are joined corresponds, in the circumferential direction, to a position of a tooth groove between the plurality of tooth portions.

A gear manufacturing method, the gear including an annular gear portion including teeth on an outer periphery, an annular support portion provided on an inner peripheral surface of the gear portion and supporting the gear portion, and a core portion provided inside the support portion, the method includes: a support portion molding step of molding the support portion by disposing the gear portion and the core portion in an annular mold and filling a resin between the gear portion and the core portion; and a support portion cooling step of cooling the support portion molded in the support portion molding step, a radial gap between the teeth of the gear portion and the mold before the support portion molding step is set to be smaller than a radial shrinkage amount of the support portion in the support portion cooling step.

A gear manufacturing method, the gear including an annular gear portion including teeth on an outer periphery, an annular support portion provided on an inner peripheral surface of the gear portion and supporting the gear portion, and a core portion provided inside the support portion, the method includes: a support portion molding step of molding the support portion by disposing the gear portion and the core portion in an annular mold and filling a resin between the gear portion and the core portion; and a support portion cooling step of cooling the support portion molded in the support portion molding step, a radial gap between the teeth of the gear portion and the mold before the support portion molding step is set to be smaller than a radial shrinkage amount of the support portion in the support portion cooling step.

A servo and a robot with the same are provided. The servo comprises a servo body, an upper cover, a lower cover, and a gear set having a plurality of gears meshing with each other. The gear set is located in the servo body, and comprises an output gear located in the center of the servo body as seen from the cross section of the servo body.