Mitsuba Corporation

Motoaki Kobayashi

Teppei Tokizaki

Naoki Kojima

Yoshichika Kawashima

Tohru Yumoto

Nobuyuki Nagai

Masaki Hayata

Satoshi Tamura

Shunji Kumagai

Masakazu Saito

A fifth ball bearing that rotatably supports a rotating shaft is provided on one side of a pinion gear in an axial direction of the rotating shaft. A sixth ball bearing that rotatably supports the rotating shaft is provided on the other side of the pinion gear in the axial direction of the rotating shaft. A carrier is provided with a bearing fixing portion that supports the fifth ball bearing immovably in the axial direction of the rotating shaft, and a bearing guide portion that supports the sixth ball bearing movably in the axial direction of the rotating shaft. The fifth and sixth ball bearings are provided so as not to be close to each other in the axial direction of the rotating shaft, and a female screw portion has a rattling adjustment member that presses the sixth ball bearing toward the side where the fifth ball bearing is provided.

Planetary gear reduction mechanism

A planetary gear reduction mechanism is capable of accurately driving an object to be driven. A carrieris provided with first and second support shaft fixing holesandto which a support shaftthat rotatably supports a planetary gearis fixed, and a shaft couplingis fixed to the carrierby a fixing pinfixed to the second support shaft fixing hole, which allows the shaft couplingto be accurately fixed to the carrierformed with high processing accuracy. Therefore, a planetary gear reduction mechanismis realized, which is capable of accurately driving a drive mechanism of a robot, which is an object to be driven.

A speed reduction mechanism has an increased reduction ratio while achieving downsizing. A speed reduction mechanismincludes a rotating shaft, a pinion gearincluding a first tooth portionextending spirally along a longitudinal direction Qof the rotating shaft, three planetary gearsincluding spiral second tooth portionsand arranged side by side in a circumferential direction Qof the rotating shaft, a housing portionhousing the three planetary gears, and an internal gearincluding a spiral third tooth portionmeshing with the second tooth portions. The first tooth portionhas at least a part of a tooth profile cross section formed in an arc shape. The second tooth portionmeshes with the first tooth portionin a state of being in contact with a portion where the tooth profile cross section is arc-shaped.

Speed reduction mechanism

A brushless motor includes a motor part and a gear part. The motor part includes: a rotating shaft, having a first gear; a rotor, having a bottom wall and a side wall, the bottom wall being fixed to the rotating shaft; magnets, fixed to the side wall and arranged side by side in a circumferential direction of the rotor; a stator, provided between the rotating shaft and the magnets in a radial direction of the rotor and wound with a coil; and a motor housing, rotatably supporting the rotating shaft, and accommodating the rotor and the stator. The gear part includes: a second gear, meshed with the first gear; an output shaft, having an output part, having a base end side thereof fixed to the second gear, and parallel to the rotating shaft; and a gear housing, rotatably supporting the output shaft, and accommodating the second gear.

Brushless motor

A deceleration mechanism is provided with first and second gears, a first tooth part arranged in the first gear and extending spirally in an axial direction of the first gear, an engagement projected part arranged on the first tooth part, second tooth parts arranged on the second gear, and an engagement recessed part arranged between the adjacent second tooth parts. The engagement projected part is formed in an arc shape in a direction orthogonal to the axial direction of the first gear and has a curvature center eccentric from a rotation center of the first gear. The second tooth parts are inclined with respect to the axial direction of the first gear and arranged in a circumferential direction of the second gear. The engagement projected part is formed in an arc-shape in a direction orthogonal to the axial direction of the first gear and engaged with the engagement projected part.

Deceleration mechanism and motor having deceleration mechanism installed therein

When viewed in the axial direction of a pinion gear (), the center (C) of a pinion main body () and the center (C) of a helical tooth () are offset from each other, the helical tooth () has a larger diameter than the pinion main body (), and the pinion main body () partially protrudes outside an imaginary circle (VC) that forms the outer shape of the helical tooth (). A cross-sectional shape of the pinion gear () can be made non-circular with the pinion main body () partially protruding outside the imaginary circle (VC) that forms the outer shape of the helical tooth ().

A speed reduction mechanism and a motor equipped with the speed reduction mechanism are provided. A pinion gear is provided with one spiral engagement projected part, and a helical gear is provided with a plurality of engagement recessed parts with which the engagement projected part is engaged. The engagement projected part and the engagement recessed part are formed so that their cross-sectional shapes along a direction orthogonal to an axial direction of the pinion gear are in arc shapes. A shape of helical teeth and a shape of the engagement recessed part are determined based on a shape of the engagement projected part provided on a spiral tooth.

Growing community of inventors

Gunma, Japan

Motoaki Kobayashi