Patent ID: 8800503

Claim:
A cooling circuit for a liquid-cooled internal combustion engine for a motor vehicle comprising: a main cooling circuit ( 2 ) including a radiator ( 6 ); a feed line ( 5 ) leading to said radiator ( 6 ); and a return line ( 7 ) leading away from said radiator ( 6 ); a bypass line ( 9 ) bypassing said radiator ( 6 ) and constructed so as to be controllable as a function of predetermined parameters; a retarder ( 4 ) of a braking device; a secondary cooling circuit ( 3 ) for said retarder ( 4 ), said secondary cooling circuit ( 3 ) having a feed line ( 11 ) and a return line ( 12 ); said main cooling circuit ( 2 ) having a flow rate to said radiator ( 6 ) and said secondary cooling circuit ( 3 ) having a flow rate to said retarder ( 4 ); a single rotary slide valve ( 10 ) arranged for controlling said main cooling circuit ( 2 ) and said secondary cooling circuit ( 3 ); said main cooling circuit ( 2 ) and said secondary cooling circuit ( 3 ) being interconnected for varying at least one of the flow rate to said radiator ( 6 ) and the flow rate to said retarder ( 4 ) in a defined manner; wherein said rotary slide valve ( 10 ) comprises a housing ( 10 a ) having four throughflow openings therein and being inserted into said feed line ( 5 ) leading from the internal combustion engine to said radiator ( 6 ); said bypass line ( 9 ) being connected to a third throughflow opening of said rotary slide valve between said feed line ( 5 ) and said return line ( 12 ); said return line ( 12 ) of said retarder ( 4 ) connected to a fourth throughflow opening ( 15 ); and wherein said feed line ( 11 ) of said retarder ( 4 ) is connected to said feed line ( 5 a ) of said main cooling circuit ( 3 ) upstream of said rotary slide valve ( 10 ); and wherein three of said four throughflow openings are arranged radially on said housing ( 10 a ) of said rotary slide valve ( 10 ); said rotary slide valve further comprising a crescent-shaped rotary slide ( 10 b ); said fourth throughflow opening ( 15 ) for said return line ( 12 ) of said retarder ( 4 ) being aligned axially with respect to said rotary slide ( 10 b ) and being permanently open; and wherein said housing, said rotary slide and said three radial throughflow openings are constructed so as to permit a least the simultaneous partial opening of all three radially arranged throughflow openings.