Nabtesco Corporation

Takashi Naruse

Koji Nakamura

Takayuki Okimura

Masahiro Takahashi

Shuichi Kamagata

A speed reducer includes an outer tubular member, internal tooth pins, oscillating gears and a carrier block. The outer tubular member has pin grooves on an inner circumferential surface thereof. The internal tooth pins are rotatably placed in the pin grooves. The oscillating gears have external teeth smaller in number than the pin grooves, and the oscillating gears are oscillatorily rotatable with the external teeth engaging with the internal tooth pins. The carrier block is cooperatively connected to the oscillating gears such that the oscillating gears are allowed to oscillatorily rotate relative to the carrier block and restricted from rotating on own axis relative to the carrier block. A displacement restricting member configured to restrict the internal tooth pins from being displaced inwardly in a radial direction of the outer tubular member is disposed between the outer peripheries of the oscillating gears adjacent to each other.

Speed reducer

A speed reducer which decelerates rotation input from a motor and outputs decelerated rotation to a wheel includes: a case fixed to a carriage body; an input portion for receiving the rotation input from the motor; an output portion for outputting the rotation to the wheel; and a speed reducing mechanism at least partially housed in the case and configured to decelerate rotation of the input portion and transmit the decelerated rotation to the output portion. The maximum outer radius of the case from the rotation axis of the output portion is larger than the radius of the wheel, and the minimum outer radius of the case from the rotation axis of the output portion is smaller than the radius of the wheel.

Speed reducer, driving wheel, and carriage

The present application discloses a steering assistance device, including: a motor configured to output a drive force in accordance with a steering force applied to a steering shaft; and a speed reducer including: a gear section configured to rotate and oscillate in accordance with the drive force; an outer cylinder having an internally toothed ring formed thereon, the internally toothed ring being configured to mesh with the gear section; and a carrier configured to rotate in accordance with rotation and oscillation of the gear section and output a steering assistance force to a steering mechanism, the steering mechanism being configured to steer vehicle wheels in accordance with rotational operation applied to a steering wheel. The engagement ratio between the gear section and the internally toothed ring is from 25 to 100%.

Steering assistance device

A gear device is provided with a crankshaft including a shaft main body and an eccentric portion, a linking member including external teeth and configured to transmit the rotation of the input gear to the crankshaft, a carrier configured to rotatably support the crankshaft, an oscillation gear oscillating and rotating, and an outer cylinder including internal teeth engaged with the oscillation gear. The carrier and the outer cylinder are configured to concentrically relatively rotate according to the rocking rotation of the oscillation gear. The linking member is configured to selectively take a first position where the external teeth are engaged with a first input gear and a second position where the external teeth are engaged with a second input gear.

Gear device

A gear device includes: a crankshaft that has an eccentric portion; an oscillation gear that has a plurality of external teeth and oscillating and rotating due to rotation of the eccentric portion; a carrier that rotatably supports the crankshaft; an outer cylinder that has a plurality of internal teeth respectively engaged with the external teeth of the oscillation gear; and a cylindrical portion that extends through the oscillation gear, the carrier, and the outer cylinder, wherein the carrier and the outer cylinder coaxially and relatively rotate due to oscillation and rotation of the oscillation gear, and wherein the cylindrical portion is disposed in either a rotational state, in which the cylindrical portion rotates, or a stationary state, in which the cylindrical portion does not rotate, depending on relative rotation of the carrier and the outer cylinder.

An axial conversion gear device includes: a crankshaft having a first eccentric portion and a shaft gear; a first oscillation gear having first external teeth; a transmitting gear having a first gear engaged with the shaft gear and a second gear spaced apart from the first gear in an axial direction of the first gear; an axial conversion unit having an external tooth gear engaged with the second gear and an axial conversion gear converting input torque into torque in an axial direction of the external tooth gear; and an outer cylinder having inner tooth pins engaged with the first external teeth of the first oscillation gear, wherein in the axial direction of the external teeth gear, the axial conversion gear is located between the first gear and the second gear.

Growing community of inventors

Mie, Japan

Takashi Naruse