Axial setting device

An axial setting device for loading the friction plates of a friction coupling or for fixing the viscous plates of a viscous coupling comprising:

• two coupling parts which are co-axially supported in a fixed housing and which coupling parts are rotatable relative to one another, a pump assembly whose housing parts are connected to the one of the coupling parts and whose conveying elements are connected to the other one of the coupling parts in such a way that, when the coupling parts rotate relative to one another, fluid is conveyed in the pump assembly, a reservoir for fluid with a variable volume, a pressure chamber delimited by an axial piston, a fluid connection from the reservoir to the pressure chamber via the pump, assembly and a pressure line, a fluid connection from the pressure chamber to the reservoir via a bypass line with a solenoid valve, said fixed housing having a primary coil which can be excited by external control means, and in one of the coupling parts, there is arranged a secondary coil which can be excited by the primary coil in a contact-free way and that the solenoid valve can be controlled in the opening sense by the secondary coil when excited by the primary coil.