Gear and Rolling Dies for Forming Gear
AssigneeMitsuba Corporation
InventorHiroji Okabe
Life of this patent
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Abstract
A gear including a gear shaft, and a gear wheel made of a resin material, the gear wheel being fixed to the gear shaft by molding. The gear having a plurality of concave portions and convex portions that repeat in a circumferential direction. The plurality of concave and convex portions are arranged such that they extend in the axial direction of the gear shaft, and arranged such that the convex portions of one concave and convex group are adjacent to the concave portions of the other concave and convex group. Due to the relative displacement of the concave portions and the convex portions, stepped portions are formed at a boundary between the concave and convex groups in the circumferential direction of the gear shaft.
Claims20
A gear comprising
- a gear shaft;
- and
- a gear wheel made of a resin material, the gear wheel being fixed to the gear shaft by molding, wherein:
- a plurality of concave and convex groups, having concave portions and convex portions that repeat in a circumferential direction are formed in an axial direction on peripheral surface of the gear shaft at a portion to which the gear wheel is fixed,
- adjacent concave and convex groups are disposed so as to arrange convex portions of one concave and convex group adjacent to concave portions of the other concave and convex group, and
- stepped portions are formed at a boundary between the concave and convex groups.
Rolling dies for forming gear that includes a plurality of concave and convex groups having concave portions and convex portions repeated circumferentially on an outer peripheral surface of a gear shaft on a portion to which a wheel of a gear is fixed by molding, the rolling dies comprising:
- adjacent rolling dies that are formed in an axial direction, wherein:
- a first rolling die of the adjacent rolling dies having convex portions and concave portions,
- a second rolling die of the adjacent rolling dies having convex and concave portions,
- the first rolling die and the second rolling die are positioned such that the convex portions of the first rolling die are arranged adjacent to the concave portions of the second rolling die.
A gear comprising:
- a gear shaft;
- and
- a gear wheel made of a resin material, the gear wheel being fixed to the gear shaft by molding,
- wherein the gear shaft includes:
- a first serration groove having convex and concave portions;
- and
- a second serration groove having convex and concave portions with the second serration groove being offset from the first serration groove in an axial direction,
- wherein the convex and concave portions of the first and second serration grooves are repeated at a same pitch in a circumferential direction on an outer peripheral surface of the gear shaft,
- wherein stepped portions are formed at a boundary between the first serration groove and the second serration groove in the circumferential direction of the gear shaft.
Dependencies are inferred from the claim text.