Reduction gear unit with rotational position sensor

摘要

A gear-equipped motor ( 1 ) is configured from a motor unit ( 2 ) and a reduction gear unit ( 4 ). The reduction gear unit ( 4 ) comprises a wave gear device ( 7 ) as a reduction gear, an output shaft ( 8 ) integrally formed on a cup-shaped flexible outer gear ( 72 ) as a reduced-rotation output element, and an absolute sensor ( 20 ) for sensing the rotational position of the output shaft ( 8 ). The absolute sensor ( 20 ) is disposed on a portion of the output shaft ( 8 ) supported in a straddle-mounted state by the flexible outer gear ( 72 ) and an output-side shaft bearing ( 12 ). The absolute sensor ( 20 ) can be provided without reducing the moment rigidity of the output shaft ( 8 ). Whereby, a reduction gear unit with a rotational position sensor having high moment rigidity can be realized.