Design of a two-stage cycloidal gear reducer with tooth modifications

• Structural characteristics of cycloidal gear drives are analyzed.
• A new two-stage cycloidal gear reducer was proposed.
• The profile modifications of the cycloidal gear tooth are discussed.
• Kinematic errors due to tooth modifications are investigated via TCA.
• A mock-up is constructed to validate the feasibility of the new mechanism.

The cycloidal gear reducer is a compact, high-ratio, and low-backlash speed reduction device. It has been commonly used for transmitting motion and torque in machinery. This paper presents the design of a new two-stage cycloidal speed reducer with tooth modifications. The topological structure of cycloidal drives is discussed and analyzed with the aid of graphs. New cycloidal gear reducers are enumerated through the topological analysis and a new two-stage cycloidal gear reducer with simpler structure is then proposed. The design of the proposed cycloidal gear reducer is also performed, including profile generation and modifications. Subsequently, kinematic errors are analyzed by using the tooth contact analysis, and the results caused by different combinations of the gear profile modifications are presented quantitatively. Finally, based on the analysis, a mock-up of the cycloidal gear drive is constructed to validate the feasibility of the new mechanism.