1. Basic Information and Positioning

• Associated Device The RV series precision harmonic drive reducers are critical components in precision transmission systems such as industrial robot joints and CNC machine tools.
• Component Role : Reducer The core drive component of the second-stage cycloidal drive In conjunction with the first‑stage planetary gear set, it converts the high‑speed, low‑torque input into low‑speed, high‑torque output while simultaneously imparting an eccentric motion profile to the cycloidal wheel, thereby serving as the key to achieving a high reduction ratio and low backlash in the transmission.
• Function and role : By means of the eccentric section of the shaft, it drives the cycloidal wheel to perform a planetary‑type eccentric oscillation, enabling meshing between the cycloidal wheel and the needle gear housing, thereby achieving cycloidal gear reduction. It is the core power‑conversion component that enables the reducer to reduce speed and increase torque.

2. Material and Process Characteristics

• Materials ：20CrMnTi Low-carbon alloy carburizing steel is the preferred material for shaft components operating under heavy-load, high-impact conditions.

3. Structural Features

• Overall structure : The stepped shaft features a shaft‑like design, comprising an input coupling section, an eccentric working section, and a support journal, among other components; it is a precision shaft component manufactured as a single integral unit.
• Eccentric Section Design The shaft features an eccentric cylindrical section that defines the eccentric motion trajectory of the cycloidal wheel. The eccentricity is directly matched to the reducer’s reduction ratio and the cycloidal wheel’s tooth profile parameters, making it the core structural element for implementing cycloidal gearing.
• Connection and Support Structure One end features a splined/keyway structure for connection to the carrier of the first-stage planetary gear set, transmitting power; the journal at both ends accommodates bearings, supporting the shaft and ensuring the stability of its eccentric motion.

4. Performance and Application Value

• Core Advantages : The high strength of 20CrMnTi material, combined with precision eccentric machining, enables this eccentric shaft to withstand the alternating loads and impacts encountered during reducer operation, while ensuring smooth cycloidal gear motion. This effectively controls transmission backlash and positioning errors, meeting the stringent requirements of industrial robots for transmission accuracy and rigidity.
• Compatible Scenarios : In applications such as industrial robot joints, CNC machine tool rotary tables, automated production lines, and servo drive systems—where high transmission accuracy, rigidity, and reliability are critical—RV reducers serve as the key core components that enable high reduction ratios and low-backlash motion.