Patent ID: 6170448
Filing Date: 2001-01-09
Classification: F01L

Abstract:
A variable valve timing apparatus for an engine, wherein the engine includes a drive shaft, a camshaft rotated by the drive shaft, a cam arranged on the camshaft, and a valve driven by the cam with a certain timing and a certain amount of lift, the variable valve timing apparatus changing the rotational phase of the camshaft relative to the drive shaft to vary the valve timing, wherein the apparatus comprises:a first rotating body rotated synchronously with the drive shaft, wherein the first rotating body houses a fluid pressure chamber;a second rotating body rotated synchronously with the camshaft, wherein the second rotating body includes a movable pressure receiver to which the fluid pressure of the pressure chamber is applied, wherein movement of the pressure receiver rotates the second rotating body relative to the first rotating body to change the rotational phase of the camshaft relative to the drive shaft; anda fluid passage for delivering fluid to the pressure chamber to move the pressure receiver, wherein the fluid passage extends through the first rotating body without extending through the second rotating body and the camshaftswherein the cam has a cam surface contacting the valve, the cam surface having a cross-sectional profile that changes axially, wherein the apparatus further comprises a camshaft moving mechanism for moving the camshaft axially to adjust the lift amount of the valve, the camshaft being axially movable relative to the second rotating body, wherein axial movement of the camshaft changes the axial position of the cam surface relative to the valve.