CAMSHAFT PHASER WITH POSITION CONTROL VALVE

摘要

A camshaft phaser includes an input member; an output member defining an advance chamber and a retard chamber with the input member; a valve spool coaxially disposed within the output member such that the valve spool is rotatable relative to the output member and the input member, the valve spool defining a supply chamber and a vent chamber with the output member; an actuator which rotates the valve spool in order to change the position of the output member relative to the input member by supplying pressurized oil from the supply chamber to one of the advance chamber and the retard chamber and venting oil to the vent chamber from the other of the supply chamber and the advance chamber; and a check valve which allows oil to flow from the vent chamber to the supply chamber and prevents oil from flowing from the supply chamber to the vent chamber.

主权项

1. A camshaft phaser for use with an internal combustion engine for controllably varying the phase relationship between a crankshaft and a camshaft in said internal combustion engine, said camshaft phaser comprising:
an input member connectable to said crankshaft of said internal combustion engine to provide a fixed ratio of rotation between said input member and said crankshaft; an output member connectable to said camshaft of said internal combustion engine and defining an advance chamber and a retard chamber with said input member; a valve spool coaxially disposed within said output member such that said valve spool is rotatable relative to said output member and said input member, said valve spool defining a supply chamber and a vent chamber with said output member; an actuator which rotates said valve spool in order to change the position of said output member relative to said input member by 1) supplying oil from said supply chamber to said advance chamber and venting oil from said retard chamber to said vent chamber when retarding the phase relationship of said camshaft relative to said crankshaft is desired and 2) supplying oil from said supply chamber to said retard chamber and venting oil from said advance chamber to said vent chamber when advancing the phase relationship between said camshaft relative to said crankshaft is desired; and a phasing check valve which allows oil to flow from said vent chamber to said supply chamber and prevents oil from flowing from said supply chamber to said vent chamber.