US Patent 9618015 Oil level control device

An oil level control device in a main tank of a supply circuit, the supply circuit comprising a main tank, a first pump which, in aspiration, is connected to the main tank, a main hydraulic circuit which is connected in inlet to the delivery of a charge pump and in outlet is connected to the main tank, a first auxiliary conduit, an auxiliary tank which receives oil from the first auxiliary conduit and which in discharge is placed in communication with the main tank. At least a control valve predisposed to control sending of oil from the first auxiliary conduit to the auxiliary tank or from the auxiliary tank to the main tank.