Motorbremse für eine mehrzylindrige Brennkraftmaschine

摘要

The invention is based on an engine brake for a multi-cylinder internal combustion engine with decompression valves which through pressurization of hydraulic pistons (27) can be actuated outside the exhaust stroke of the engine's working piston, in particular at the end of the compression stroke. In accordance with prior art, the engine brake has a radial piston pump (10) provided with control outputs for the pressurization and de-pressurization of the hydraulic pistons of the decompression valves. The control outputs are mounted axially opposite a distributor unit (60) and can be connected alternately, via the distributor unit, with a high-pressure zone (21) and a low pressure zone (24) in the pump. In the known engine brake, the radial piston pump has externally supported radial pistons. According to the invention, by contrast, the radial piston pump is provided with internally supported radial pistons. The pump housing comprises a first housing section (12) with the radial pistons and a chamber for the eccentric (42) which controls the radial pistons, and a second housing section (13) with the control outputs (48). Two distributor disks (61, 62) of the distributor unit can move axially and sealingly relative to each other. The first distributor disk (61), which separates a first pressure zone (21) inside the first housing section (12) from a second pressure zone (24) between the two housing sections, can be forced axially against the first housing section, while the second distributor disk (62), which connects one control output (48) to only one pressure zone, can be forced axially against the second housing section (13).