PURPOSE: To generate a hysteresial torque conformed to an operating angle in spite of a twist angle as well as to improve the extent of reliability, in a viscous damper mechanism.

CONSTITUTION: This liquid viscous damper mechanism is provided with a liquid chamber housing 18 which is housed with a liquid inside, rotating together with an input side member, and inserted with part of an output side member into the inner part. so is so provided with a slider 30, which is set up shiftably in a specified angle range in the housing 18, and formed into a box shape with an outer circumferential wall and a side wall coming into slide contact with an inner circumferential surface and a side wall of the housing 18, respectively, and a first choke part formed in space between this slider 30 and a part of the output side member. Furthermore, it is provided with a second choke part being formed in space between the liquid chamber housing and the output side member, and having a narrower clearance than that of the first choke member, and in this connection, a lubricating groove ranging from the outer circumferential wall to the side wall is formed on a surface of the slider.