Patent ID: 6202611
Filing Date: 2001-03-20
Classification: F01L,Y10T

Abstract:
A camshaft drive device for an internal combustion engine having a crankshaft, said camshaft drive device comprising a timing drive assembly located at one end of said engine and a control assembly located at the other end of said engine, said timing drive assembly having a drive gear adapted to be driven by said crankshaft of said engine, a hollow camshaft extending between said timing drive assembly and said control assembly, a quill shaft coaxially mounted within said hollow camshaft and having a first portion located at said one end of said engine and being connected to said drive gear, said quill shaft having a second portion located at said other end of said engine and being formed with a plurality of hemispherical cavities located in a plane extending transversely to the longitudinal axis of said quill shaft, a ball located in each of said hemispherical cavities of said quill shaft, said hollow camshaft being rigidly connected to a cylindrical extension encircling said second portion of said quill shaft and having its inner cylindrical surface formed with straight splines extending along the longitudinal axis of said hollow camshaft, an axially movable sleeve member being connected with a cylindrical connector member located between said balls of said quill shaft and said straight splines, said cylindrical connector member having the outer surface thereof supporting a plurality of circumferentially spaced balls which mate with said straight splines of said cylindrical extension and having the inner surface thereof formed with helical splines which mate with the balls of said quill shaft, a nut member surrounding said sleeve member and being drivingly connected to said sleeve member through a plurality of circumferentially spaced non-recirculating balls encapsulated in said sleeve member and located in a helical groove formed in said nut member so that, upon rotation of said nut member, said sleeve member and said cylindrical connector member are moved axially to cause said helical splines of said cylindrical connector member and through said straight splines of said cylindrical extension to provide a phase change of said camshaft relative to said drive gear.