Patent ID: 6216654
Filing Date: 2001-04-17
Classification: F01L

Abstract:
A phase changing device 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 coaxially mounted within said hollow camshaft and having a first portion located at said other end and being connected to said hollow camshaft by a plurality of helical splines integrally formed with said quill shaft and surrounding said first portion of said quill shaft,a hub member fixed with said drive gear,a second portion of said quill shaft located at said one end of said engine and being connected to said hub member by a plurality of straight splines integrally formed with said quill shaft,an axially movable sleeve member connected to and surrounding said first portion of said quill shaft located at said other end of said engine,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 be angularly repositioned relative to said drive gear, andan electric stepper motor forming a part of said control assembly for rotating said nut member so as to cause the axial movement of said quill shaft and said sleeve member.