REDUCTION GEAR AND VARIABLE VALVE TIMING DEVICE USING SAME

摘要

A reverse input torque which is input into the output shaft of a reduction device is to be prevented from being transmitted to the input shaft of the reduction device. The reduction gear comprises a housing (11), the input shaft (12) and the output shaft (13), an internal gear (14) secured to the housing (11), and rollers (21) so held between eccentric shaft sections (17) formed on the input shaft (12) and the internal gear (14) as to be rollable in a roller retainer section (22).  A lock means for so holding a pair of engagement elements (26) by an engagement element retainer section (28) as to be engageable with and disengageable from the housing (11) and the output shaft (13) and a lock releasing means for releasing the engagement of the housing (11) and the output shaft (13) by pressing either one of the pair of engagement elements (26) to a wedge-shaped space (25) increasing side by the engagement element retainer section (28) when an input torque acts on the input shaft (12) are installed in a plurality of wedge-shaped spaces (25) formed between the housing (11) and the output shaft (13).