CAMSHAFT PHASER WITH A ROTARY VALVE SPOOL

摘要

A camshaft phaser includes a stator; a rotor defining an advance chamber and a retard chamber with the stator; a valve spool that is rotatable about an axis and defining a supply chamber and a vent chamber with the rotor; an actuator which rotates the valve spool to change the position of the rotor relative to the stator by 1) supplying oil from the supply chamber to the advance chamber and venting oil from the retard chamber to the vent chamber and 2) supplying oil from the supply chamber to the retard chamber and venting oil from the advance chamber to the vent chamber; and a check valve which is displaceable axially between an open position which allows oil to flow from the vent chamber to the supply chamber and a closed position which 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 about an axis 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 recirculation check valve which is displaceable axially between 1) an open position which allows oil to flow from said vent chamber to said supply chamber and 2) a closed position which prevents oil from flowing from said supply chamber to said vent chamber.