Sumitomo Heavy Industries, Ltd.

Sueo Fukaya

Takashi Haga

Shigeo Watanabe

Takashi Hatanaka

A simple planetary gear mechanism is provided with an automatic alignment function to support the planet gear to obtain a speed reducer having reduced backlash by a simple method. A planet gear is supported by a carrier pin that is in turn supported by a carrier. The carrier pin includes a crank portion that is eccentric by &ldquo;e&rdquo; relative to the axis center of the carrier pin with the eccentric angle being made variable. The planet gear is supported rotatably about the axis center of the crank portion. Consequently, with the eccentric angle being made variable, the axis center of the planet gear is automatically aligned in the radial direction upon assembly of each gear, thereby making it possible to minimize backlash only by incorporating a sun gear having a proper dimension.

Support structure for planet gear in simple planetary gear mechanism and method for manufacturing the mechanism

A reduction gear mechanism applicable for a geared motor used for lifters for business equipment or the like. A trochoid tooth profile internally meshing type planetary reduction gear mechanism is used as the basic reduction gear mechanism. Each of an external gear and an internal gear is formed of a resin having a small rigidity. Each of an output shaft and a bearing supporting the external gear is formed of a metal having a large rigidity. As a result, the reduction mechanism ensures the rigidity and rotational smoothness in usual operation. Moreover, when a torque more than a value required for a mating member to be driven is applied, the external gear and internal gear are deformed, resulting in the increased meshing loss. The reduction mechanism can reduce the efficiency mechanically by the increase in the meshing loss. Even if a reversing load is applied from the output shaft side, the efficiency can be also reduced by the same meshing loss. Namely, there can be obtained a reduction gear provided with an overload preventive function or reverse rotation preventive function without addition of any special mechanism.

Reduction gear with eccentric body

Speed change gears wherein an external gear (103 in FIG. 1) is protrusively formed with a plurality of inner pins (103b) of circular cylindrical shape. The rotation of the external gear (103) corresponding to a rotational component on the axis thereof after the absorption of the rocking thereof is directly derived from a pinion gear (106). The pinion gear (106) is formed with inner pin holes (106a) into which the respectively corresponding inner pins (103b) can be loosely fitted. The power is transmitted to or from an opposite gear (27) through the pinion gear (106).

Speed change gears adopting internal-meshing planetary gear construction

A gear reducer for reciprocal rotation wherein the rotation of a motor 1 is transmitted to a worm pinion 4 integrated with an input shaft 2, and is further transmitted to a helical worm wheel 10. The helical worm wheel 10 and an eccentric member 11 are spline coupled to each other, and a pin flange 13 is rotated by a planetary gear structure of a trochoid-tooth-profile inscribing type. Consequently, a pinion shaft (output shaft) 14 integrated with the pin flange 13 rotates, and an outside gear 19 rotates.

Compact gear reducer for rotation through an angle in either directions

An internal meshing type planetary gear reducer made of plastic material constructed in such a manner that an external gear fitted on an eccentric member integrally formed on an input shaft internally meshes with an internal gear, and inner pins formed on the external gear integrally therewith are inserted in inner-pin holes provided in a flange formed at one end portion of an output shaft so that rotation of the input shaft is reduced in speed and the speed-reduced rotation is transmitted to the output shaft. In the internal meshing type planetary gear reducer, each inner pin is provided with cutouts on inner and outer sides thereof in a radial direction of the external gear, or each inner-pin hole is provided with cutouts on inner and outer sides thereof in a radial direction of the flange, and only the inner pins which serve to transmit a torque at a predetermined range of the contacting location are arranged to be in contact with the inner-pin holes. With such construction, there is little resistance between the moving parts and the forcedly resistive sliding motion can be eliminated, whereby the torque transmission can be performed smoothly.

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Ohbu, Japan

Sueo Fukaya