Enplas Corporation

Kazuki Yamada

Koki Hisai

Takuya Kaneko

Toshiki Kawada

Shohei Ishida

Separate structural units for an inner gear and a housing of a planetary gear device include an inner gear with a first raised portion formed on the outer peripheral surface of the inner gear, where the first raised portion extends towards in a direction that is inclined with respect to the axial direction of the inner gear. A housing includes a second raised portion formed on an inner peripheral surface, where the second raised portion extends in a direction that is inclined in respect to the axial direction. The housing contains the inner gear such that there is a gap formed between the inner peripheral surface of the housing and the outer peripheral surface of the inner gear. Movement of the inner gear within the interior of the housing is limited through linear contact of the first raised portion and the second raised portion.

Gear housing for a planetary gear device that structurally isolates an inner gear

A planetary gear device includes: a housing cover disposed at one end portion of a housing in an axis direction, the housing being configured to house a sun gear and a planetary gear inside the housing; and a carrier cover disposed next to the housing cover in the axial direction in the inside, and configured to support a shaft of the planetary gear from one end portion side in the axial direction. Of a pair of opposing parts opposite to each other in the housing cover and the carrier cover, one opposing part includes an opening that opens in the axis direction, and the other opposing part includes a slide cylindrical part protruding toward inside of the opening in a coaxial manner with an axis of the opening, the slide cylindrical part including an outer peripheral surface that slides on an inner peripheral surface of the opening.

Planetary gear device

A planetary gear device includes: a housing cover disposed at one end portion of a housing in an axis direction, the housing being configured to house a sun gear and a planetary gear inside the housing; and a carrier cover disposed next to the housing cover in the axial direction in the inside, and configured to support a shaft of the planetary gear from one end portion side in the axial direction. One opposing part of a pair of opposing parts opposite to each other in the housing cover and the carrier cover includes a cone-shaped part whose diameter varies in the axial direction, and the other opposing part of the pair of opposing parts includes a sliding part configured to slide on a peripheral surface of the cone-shaped part with a same axis as an axis of the cone-shaped part.

An aspect of a carrier for a planetary gear device includes two separate endplates that fit together using a snap-fit assembly. Retention protrusions extending from one of the endplates snap-fit into corresponding recesses on the other endplate to assemble the carrier. The shape of the recess is configured to reduce or eliminate any tendency for loads to force retention protrusion to disengage from the recess, which may result in loss of structural integrity of the carrier.

Planetary gear carrier for a planetary gear device

A lubrication system for a planetary gear device includes a planetary gear mounted on a planetary gear shaft. The shaft is mounted in a shaft hole that allows the gear to rotate freely about the shaft. Lubricant reservoirs formed as voids or spaces on the inner surface of the shaft hole and outer surface of the shaft provide additional volume for lubricant to lubricate the shaft and shaft hole interface. These lubricant reservoirs extend the lifespan of the lubricant and reduce maintenance requirements of the planetary gear.

Planetary gear shaft lubrication system

A gear tooth for a gear of a planetary gear device may include a profile modification that alters a profile of the gear tooth to reduce wear and noise. Aspects of the profile modification may include a planar surface that connects a tip surface of the gear tooth with a first or second side of the gear tooth. Other aspects of the profile modification may include a curved surface connecting a tip surface of the gear tooth with a first or second side of the gear tooth. The gear tooth may also include non-constant profile width as measured between the first side and the second side in a gear thickness direction extending between the top and bottom surfaces of the gear. Aspects of gear teeth with either or both the profile modification and non-constant profile width may reduce tooth wear and gear noise during operation of the planetary gear device.

Growing community of inventors

Kawaguchi, Japan

Kazuki Yamada