Patent ID: 6167854
Filing Date: 2001-01-02
Classification: F01L

Abstract:
A variable valve timing mechanism for an internal combustion engine 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 the crankshaft of said engine, a hollow camshaft extending between said timing drive assembly and said control assembly, a quill shaft co-axially mounted within said hollow camshaft and having a first portion located at said one end of the engine and being connected to said hollow camshaft by a plurality of straight splines surrounding said first portion of said quill shaft, a hub member fixed with said drive gear, said first portion of said quill shaft being connected to said hub member by a plurality of helical splines, an axially movable sleeve member connected to and surrounding a second portion of said quill shaft located at said other end, and 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 one of said members and located in a helical groove formed in the other of said members so that, upon rotation of said nut member, said sleeve member and said quill shaft move axially relative to said camshaft and simultaneously through said helical splines cause said camshaft to change its angular position with respect to said drive gear.