Gm Global Technolgoy Operations, Inc.

Thomas H Lichti

Michael J Niemiec

Mark A Shost

Ronald A Waydelis

Kenneth A Kovacevich

Michael James Fox

Michael E McCarroll

Daniel R Cuatt

Thomas G Elphick

A variable cam phaser has drive and driven members connected by helical splines of an annular phase control piston and a lash control piston, axial motion of which varies the angular phase relation between the drive and driven members. A single wave spring received in a groove in one of the pistons biases them apart to take up lash in the splines. A return spring biases the phase control piston to an initial phase setting. Pre-timing of the members is provided for by a driven (or drive) member comprising two components, a hub flange that supports the other member and a splined hub carried by and initially rotatable on a tubular protrusion of the hub flange. After assembly of the phasing mechanism, the hub is rotated on the hub flange to pre-time the initial phasing of the members. An end of the tubular protrusion is then deformed into a flange engaging an annular shoulder on the hub to lock the hub and hub flange members together and maintain the pre-timing. An annular cover is then installed and retained by a retaining ring to close a hydraulic pressure chamber and help support the members. Upon assembly to a camshaft, a center bolt clamps the cover, hub and hub flange to the camshaft and relieves the locking means from operational torque loads.

Variable cam phaser and method of assembly

A variable camshaft phaser (VCP) has lash take up drive piston assemblies with inner and outer helical splines for phase changing and return springs mounted in pockets in the pistons to shorten overall length for a compact unit and also relieve lash take-up friction on the piston return strokes. Numerous other features are included. A three-way feed-discharge valve limits oil flow to that necessary to operate the drive pistons for phasing.

Compact camshaft phasing drive

A variable camshaft phaser (VCP) has various embodiments and features including inner and outer helical splines for phase changing and return springs mounted in pockets to shorten overall length and relieve lash take-up friction on the piston return strokes. A three-way feed-discharge valve limits hydraulic actuating oil flow to that required to operate the drive pistons for phase changing operation. The three-way valve may be carried in a srew or fastener that secures the phaser to a camshaft or other rotary member.

Hydraulic phasers and valve means therefor

A phase adjuster for engine camshafts and the like includes in a preferred embodiment a sprocket driving a camshaft attached hub through paired wedge packs that transfer torque and maintain a lash free connection. A plunger actuated by engine oil pressure and coating drive springs axially move alternate active wedges to oppositely vary the arcuate lengths of the wedge packs and thereby change the phase angle between the sprocket and camshaft. A three way valve shuts off pressure oil flow except when needed to advance the plunger, thus minimizing oil flow requirements.

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Rochester, NY, United States of America

Thomas H Lichti