Patent ID: 6817455
Filing Date: 2004-11-16
Classification: B60T,F16D,F16H

Abstract:
A retarder system for a motor vehicle having a retarder coolant circuit (4) comprising:a retarder (1); a radiator (3); a retarder pump (12) for supplying transmission oil from a transmission sump (13) to the radiator (3); at least one of a control valve (9) and a regulating valve (10) for regulating flow of transmission oil required by the retarder (1) as an operating fluid when preforming required braking; and a switch valve (2), when in a first position in which the retarder (1) is in an inactive state, connecting the retarder pump (12) with the radiator (3) so that the transmission oil, supplied from the transmission sump (13), is returned to the transmission sump (13) via the radiator (3) without passing through the retarder (1) and the switch valve (2), when in a second position in which the retarder (1) is in an active state, connecting the radiator (3) with the retarder (1) for forming a closed loop cooling circuit (4); wherein a transmission oil circuit (18) has a transmission pump (20) for supplying transmission oil from the transmission sump (13) to at least one other component of the transmission for lubrication thereof, and the transmission oil circuit (18) has a connection (21) with the retarder cooling circuit (4) such that transmission oil can be branched off from the transmission oil circuit (18) for increasing the flow rate of transmission oil through the radiator (3); and a one way valve (23) is provided along the transmission oil flow path, between the retarder pump (12) and the retarder cooling circuit (4), to prevent transmission oil from flowing back toward the transmission sump (13), and a one way valve (24) is provided along the transmission oil flow path, between the transmission pump (20) and the retarder cooling circuit (4), to prevent transmission oil from flowing back toward the transmission sump (13).