Strain wave gears are small, lightweight reducer with a high reduction ratio. For reduction gears used in robots and transport equipment that require precise movements, high precision and low backlash are required. NPR-RIKEN is developing products that are lighter while maintaining high precision by utilizing our resin manufacturing technology to develop engineered plastic strain wave gears.

Structure of strain wave gears

It has a compact shape because of three basic parts.

Operation principle

0 degree

1

The flexspline is deformed into a non-circular shape by the wave generator.

90 degrees

2

When the ring gear is fixed and the wave generator is rotated clockwise, the meshing position of the flex spline shifts.

180 degrees

3

Rotating the wave generator 180 degrees causes the flexspline to move counterclockwise by half the tooth difference with the ring gear.

360 degrees

4

Rotating the wave generator 360 degrees causes the flexspline to move by the tooth difference relative to the ring gear. This movement becomes the output.

Engineered plastic strain wave gears

We are developing wave gear reducers with flex spline and ring gear made of super engineering plastic. Even in resin construction, it achieves high reducer precision and torque capacity. Various sizes and reduction ratios are available, so please inquire for details.

Application examples

①Vertically articulated robots

The tip portion of collaborative robots and SCARA robots, etc.

②Precision instruments, inspection and analysis equipments

Movable part, etc.

③Humanoid robots

Joints, robot hands, etc.

We are developing motors and reducers focused on thinness alongside miniaturization, as well as actuators combining these components. We aim to create actuators that can fit easily into even layout-challenging environments.

Actuators for small mobility

This is a thin, high-output actuator. Thinness was achieved by combining our proprietary in-house designed axial gap motor with a 3K planetary gear reducer. Furthermore, the 3K planetary gear reducer possesses high transmission efficiency, enabling back drivability.

Actuators for small drive unit

This is a compact, flat actuator. The motor section is a radial gap motor, contributing to reducing diameter. The reducer is a specialized cycloidal gear mechanism, achieving a structure specialized for thin type. Integrating these two components results in an actuator designed for extremely flat, compact drive applications.

Application examples

Collaborative robots, AGV (Automated Guided Vehicle), Maintenance robots, Medical devices (Nursing care robots, Assist suits), Inspection・analysis equipments and Aerospace.

※ This page introduces a part of our lineup.
We can also provide flat-profile motors and flat-profile reducers, not just flat-profile actuators.
(Motors are also available in frameless type.)
We are also available to discuss product requirements (size, torque, rotational speed, etc.).

Flat-profile, high-torque axial gap motor

This motor features a structure in which the air gap between the rotor and stator is arranged orthogonal to the rotational axis. Compared to conventional radial gap motors, it is characterized by a flat shape and high torque. Because the magnetic circuit becomes three-dimensional, the pressed powder core is suitable as the motor core.

■Development Cases

In-wheel motor for agricultural robots
Size: Φ188 × 155 mm Output: 150W (MAX 100Nm)
This low-speed, high-torque motor integrates a flat axial gap motor, reducer, and brake into a single unit, featuring an IP56-equivalent waterproof and dustproof structure.
Features IP56-equivalent dustproof and waterproof construction with low-speed, high-torque characteristics delivering a maximum torque of 100Nm.

Frameless motor

Size: Φ72 × 23 mm　Output: 310W
This flat, large-bore hollow axial gap frameless motor can be used for collaborative robot joint drives and compact actuators. It allows easy passing of wires and air tubes through the hollow section, and motor characteristics can be altered by changing the air gap.

Motor for small mobility drive

Size：Φ72×43mm　Output：300W
This is an axial gap motor for small mobilities and pump applications. It can be used as an in-wheel motor when combined with a reduction gear. It also contributes to slimmer pump designs by integrating with the impeller.

Ultra-compact motor

Size：Φ34×17mm　Output：10W
A flat, lightweight axial gap motor for small actuators is suitable for use in compact fans and drones.

Hollow motor

Size：O.D. Φ65mm　I.D. Φ30mm
This is an axial gap motor with an enlarged diameter of a hollow.

Pressed powder core

This motor core is manufactured by press-formed soft magnetic powder coated with an insulating film. Compared to conventional electromagnetic steel sheets, it offers the advantages of “high degree of freedom for shape”, “low eddy current loss”, and “capability to form three-dimensional magnetic circuits”. Consequently, it enables motor miniaturization and high-torque.