A rotary actuator includes a motor, an output shaft, and a speed reducer. The motor includes a motor shaft rotating about an axial direction. The output shaft is disposed in parallel with the motor shaft. The speed reducer reduces a rotational speed of the motor and transmits rotation of the motor at a reduced rotational speed to the output shaft. The speed reducer includes a parallel-shaft type reducer that has a drive gear on the motor shaft and a driven gear on the output shaft. One side and the other side in the axial direction are defined as a first side and a second side, respectively. The motor is located on the first side of the speed reducer in the axial direction. The driven gear includes a teeth portion having a gear end surface on the first side of the teeth portion. The motor includes a stator having a stator end surface on the second side of the stator. The gear end surface is located on the first side of the stator end surface in the axial direction.

A speed reducer according to the present invention includes: at least one gear member for changing a speed of rotations input from a rotary device and outputting the rotations; a case housing the gear member; and a heating unit provided on the case and configured to heat the case or an inside of the case.

The present invention provides a transmission mechanism that enables a reduction in motion transmission error between an input-shaft side and an output-shaft side. A transmission mechanism is provided with a cam, a plurality of pins arranged along a side surface of the cam, guide plates in which a plurality of guide holes are provided, and gears capable of engaging the pins. In conjunction with rotation of the cam, each pin is guided by the corresponding guide hole and moves along the cam and the gears, thereby causing the guide plates or gears to rotate relative to the cam. The plurality of pins are divided into a plurality of groups, and the pins in each group are coupled in series, but are not coupled to the pins in the other groups.

The present invention provides a transmission mechanism which is suited to miniaturization and can reduce motion transmission errors. This transmission mechanism includes: a cam; a plurality of pins arrayed along a side surface of the cam; guide plates provided with a plurality of guide holes; and a pair of gears disposed so as to sandwich the cam. Each pin contacts only one of the pair of gears, and is guided to the corresponding guide hole in conjunction with the rotation of the cam and moves along the cam and the corresponding gear, thereby causing the guide plates or the pair of gears to rotate with respect to the cam.

Disclosed in the present invention is a transmission mechanism, comprising an outer wheel, an inner wheel, an eccentric shaft, a first flange body, a rotating shaft and a planetary gear device. The inner wheel is provided in the outer wheel and is engaged with the outer wheel. The eccentric shaft can rotate around a central axis; an eccentric portion, eccentric shaft outer teeth and a first support portion are provided on the periphery of the eccentric shaft; and the inner wheel is provided around the eccentric portion. The first flange body and the inner wheel are provided side by side, and the first flange body is provided around the first support portion. The rotating shaft has rotating shaft external teeth. The planetary gear device is supported by the first flange body, and a first row of planetary teeth engaged with the rotating shaft outer teeth and a second row of planetary teeth engaged with the eccentric shaft outer teeth are provided at the periphery of the planetary gear device. The transmission mechanism can provide a wide range of speed ratios and reduce production costs.

A gear motor of an electrical assistance device for a cycle is provided, including a gear reducer and an electric motor, which are configured to be fitted coaxially on a central shaft, the gear reducer including at least one planet wheel, which is fitted firstly on an eccentric cam, the planet wheel also having passing therethrough at least three shafts of the satellite-carrier, the at least three shafts including a respective peripheral surface configured to come into contact with a hole of the planet wheel, which surface is made of polymer material, and/or the at least one planet wheel is made of polymer material.

The present invention relates to a cycloidal speed reducer and a manufacturing method thereof, and more particularly, to a thin cycloidal speed reducer and a manufacturing method thereof that are capable of achieving a thin structure through an input member with a hollow portion.

A speed reducer according to one aspect of the present disclosure includes: an input gear; a plurality of spur gears configured to rotate in mesh with the input gear; one or more eccentric cams formed on each of a plurality of shafts, each of the plurality of shafts being coupled to corresponding one of the plurality of spur gears; and one or more eccentric gears each having a plurality of first through-holes and a plurality of second through-holes, each of the plurality of first through-holes rotatably supporting corresponding one of the one or more eccentric cams, the second through-holes being disposed adjacent to the first through-holes and formed asymmetrically as viewed from a direction of a central axis, and the one or more eccentric gear are configured to rotate eccentrically relative to a rotational axis of the input gear in conjunction with rotation of the one or more eccentric cams.

One aspect of an electric actuator of the present invention includes: a motor having a motor shaft rotatable about a motor axis; a transmission mechanism coupled to one side in the axial direction of the motor shaft; an output shaft extending in the axial direction of the motor shaft and to which rotation of the motor shaft is transmitted via the transmission mechanism; and a rolling member group including three or more rolling members arranged to surround the motor axis. The motor shaft is a hollow shaft. At least a part of the output shaft is located inside the motor shaft. The motor shaft and the output shaft are supported with each other in the axial direction and the radial direction via the rolling member group.

A rotation driving device includes: a body 10, made of resin, and having an accommodation hole 13 in a cylindrical shape with an axis S as a center; a motor M, comprising a rotor 60 provided in an accommodation hole of the body and rotating around the axis and a rotation shaft 40 integrally rotating around the axis with the rotor and extending in an axial direction; a first bearing B1 fixed to an end side of the body and a second bearing B2 fixed to the other end side of the body in the axial direction, so as to rotatably support the rotation shaft; and a first cover member 110 connected to the one end side of the body and a second cover member 120 connected to the other end side of the body.