Standard RV (Rotary Vector) speed reducers are precision-designed reduction devices specifically for mechanical applications, featuring a two-stage enclosed differential gear train structure composed of cycloidal pin gears and planetary gears in an open configuration that requires flange sealing and filling with specialized RV grease during use. In industrial robotics, for robotic arms with end loads under 20kg, RV reducers are mainly used in the base-to-high-load joints (typically joints 1-4); for robotic arms with end loads exceeding 20kg, all six corresponding joint degrees of freedom utilize RV reducers. RV reducers serve as the core transmission components ensuring robotic arm positioning accuracy. Standard RV reducers can be categorized into solid-shaft standard E-series and hollow-shaft standard C-series based on their structural characteristics. Usage note: Both standard E-series and C-series are unsealed open structures requiring customers to perform flange sealing and inject specialized RV lubricating grease after purchase, with the factory solid input shafts needing secondary boring and slotting according to customer motor shaft specifications (our company can provide custom machining services based on customer-provided input shaft machining drawings).