System, particularly an electrohydraulic system, for adjusting the pressure force of a continuously variable transmission

Abstract

A system (10), in particular an electrohydraulic system (10), for adjusting the contract pressures of a continuously variable gear, in particular a double-cone pulley belt-contact gear, which has a device for changing the gear ratio of the gear having at least one primary pressure chamber and one secondary pressure chamber is proposed. An electrically triggerable primary pressure valve (Vprim) for adjusting the pressure in the primary pressure chamber and an electrically triggerable secondary pressure valve (Vsec) for adjusting the pressure in the secondary pressure chamber are provided. The pressure (pprim) of the primary pressure chamber and the pressure (psec) of the secondary pressure chamber can be carried to the secondary pressure valve (Vsec). The object is to enable a more-accurate adjustment of the pressure (pprim) in the primary pressure chamber. To that end, the trigger current (Isec) of the secondary valve (Vsec) is set to a value which corresponds to a predetermined pressure (psec,soll) in the primary and the secondary pressure chamber. Moreover, the pressure (psec,soll) in the secondary pressure chamber is regulated, via the trigger current (Iprim) of the primary valve (Vprim), so that the pressure (pprim) in the primary pressure chamber is established indirectly.

Dependencies are inferred from the claim text.