Compression relief engine brake
A compression relief brake is described for four cycle internal-combustion engines, comprising: a pressurized oil supply; means for selectively pressurizing a hydraulic circuit with oil from the oil supply; a master piston and cylinder communicating with a slave piston and cylinder via the hydraulic circuit; an engine exhaust valve mechanically coupled to the engine and timed to open during the exhaust cycle of the engine the exhaust valve coupled to the slave piston. The exhaust valve is spring-based in a closed state to contact a valve seat; a sleeve frictionally and slidably disposed within a cavity defined by the slave piston which cavity communicates with the hydraulic circuit. When the hydraulic circuit is selectively pressurized and the engine is operating the sleeve entraps an incompressible volume of oil within the cavity to generate a displacement of the slave piston within the slave cylinder, whereby a first gap is maintained between the exhaust valve and its associated seat; and means for reciprocally activating the master piston for increasing the pressure within the previously pressurized hydraulic circuit during at least a portion of the expansion cycle of the engine whereby a second gap is reciprocally maintained between the exhaust valve and its associated seat.
- Assignee:
- NOV; NOV-88-086101; EDB-88-009357
- Patent Number(s):
- US 4697558
- OSTI ID:
- 5853987
- Resource Relation:
- Patent File Date: Filed date 18 Feb 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BRAKES
DESIGN
HYDRAULICS
INTERNAL COMBUSTION ENGINES
COMPRESSION
CYLINDERS
EXHAUST SYSTEMS
HYDRAULIC FLUIDS
OPERATION
PISTONS
PRESSURE DEPENDENCE
PRESSURIZING
RELIEF VALVES
CONTROL EQUIPMENT
ENGINES
EQUIPMENT
FLOW REGULATORS
FLUID MECHANICS
FLUIDS
HEAT ENGINES
MACHINE PARTS
MECHANICS
VALVES
WORKING FLUIDS
330100* - Internal Combustion Engines