To provide an axial direction setting device to perform an external disconnecting function by a simple means.

This axial direction setting device is constituted of two members 13, 14 free to relatively rotate in a housing 12, a container 30 for a fluid carrier pump structural body and variable fluid, a pressure chamber 28 partitioned by an axial direction piston 26, fluid connection through a pump structural body 32 and a pressure line 29 to the pressure chamber from the container and fluid connection through a by-pass line 35 furnished with a solenoid valve to the container from the pressure chamber, a primary coil 38 is arranged in the fixed housing 12, a secondary coil 37 to be excited by the primary coil 38 is arranged on one of the two members, and the solenoid valve 36 can be controlled in the opening direction by the secondary coil 37 when it is excited by the primary coil 38.