Patent ID: 7029409

Claim:
A hydraulic system of a CVT transmission for a motor vehicle comprising a variator having a first pulley set ( 8 ) and a second pulley set ( 9 ), the hydraulic system comprising: an oil pump ( 1 ) to convey oil from an oil slump ( 3 ) through a main supply line ( 5 ) at a main hydraulic supply pressure (pHD) to a first valve supply line ( 18 ) and a second valve supply line ( 23 ); a first valve mechanism ( 6 ) is supplied with oil via the first valve supply line ( 18 ) to effect a respective first pressure (pS 1 ) acting on the first pulley set ( 8 ), and a second valve mechanism ( 7 ) is supplied with oil via the second valve supply line ( 23 ) to effect a respective second pressure (pS 2 ) acting on the second pulley set ( 9 ); and wherein a pressure selector valve ( 20 ) is connected between the main supply line ( 5 ) and the second valve mechanism ( 7 ) to regulate the main hydraulic supply pressure (pHD) between the first valve mechanism ( 6 ) and the second valve mechanism ( 7 ).