Hydraulic circuit for hydrodynamic transmission - can selectively divert output from heat exchanger over dynamic brake

摘要

The hydrodynamic transmission has an oil pump (5) which pumps the oil through a heat exchanger and from there to the torque converter. If the vehicle is braked, a special hydrodynamic brake (10) is supplied with oil from the circuit via a supply valve (11) and a brake control valve (12). For improved cooling the oil is taken from the output of the heat exchanger (8) so that the cool oil is driven under pressure through the brake. The heat exchanger thus caters for both circuits, with the torque converter demands dropping during braking. The heat exchanger is kept compact with a pressurised cooling circuit.