US 5,417,186 AGranted

Dual-acting apparatus for variable valve timing and the like

AssigneeClemson University

InventorsAlvon C. Elrod, Michael T. Nelson

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Abstract

An apparatus and method effects the cyclical actuation of an actuation member. The apparatus can be driven by a crankshaft and has at least one dual-acting phasing apparatus with at least three rotatable mounted internally splined members and at least a first rotatably mounted, externally splined, flexible member having a portion thereof rotatably disposed within each of at least two of the internally splined members. One inner splined member can be connected nonrotatably to a first rotatable member such as an inner shaft, which is rotatably disposed within an outer shaft of a concentric camshaft. Another internally splined member can be nonrotatably connected to the outer shaft. Yet another internally splined member can be nonrotatably connected to a pulley wheel driven by the crankshaft. A fourth internally splined member can be connected to one of the other three internally splined members. A second externally splined, flexible member can be disposed with a portion thereof rotatably disposed within each of at least two of either the three or four internally splined members. Various configurations of cam members and camlobe members can be disposed as integral portions of the inner shaft and the outer shaft. The cam members can be fixed or variable, full width cam members or splittable cam members. More than one concentric camshaft can be controlled by a single dual-acting phasing mechanism. More than one dual-acting phasing mechanism can be used to control two camshafts, concentric or conventional.

An apparatus driven by a drive means about an axis of rotation to effect the cyclical actuation of an actuation member, the apparatus comprising:

a first internally splined member, said first internally splined member defining a first circularly cylindrically configured interior surface, said first interior surface defining a plurality of splines, said first internally splined member being configured and disposed for rotating about said axis;
a means for linking said first internally splined member for rotation about said axis in phase with a first rotatable member;
a second internally splined member, said second internally splined member defining a second circularly cylindrically configured interior surface, said second interior surface defining a plurality of splines, said second internally splined member being configured and disposed for rotating about said axis;
a means for linking said second internally splined member for rotation about said axis in phase with a second rotatable member;
a third internally splined member, said third internally splined member defining a third circularly cylindrically configured interior surface, said third interior surface defining a plurality of splines, said third internally splined member being configured and disposed for rotating about said axis;
a means for linking said third internally splined member for rotation about said axis in phase with a means for engaging the drive means;
a first cylindrically configured flexible member, said first flexible cylindrical member defining a splined outer surface, said first flexible cylindrical member being flexible enough so as to be elastically deformable from said first flexible cylindrical member's unflexed transverse shape, said first flexible cylindrical member being rotatably disposed about said axis and at least partially within each internally splined member of at least a first pairing of two of said first, second, and third internally splined members;
and
a first wave generator disposed rotatably within said externally splined flexible cylindrical member, said first wave generator being configured with an approximately elliptical transverse cross-sectional shape that deforms said first flexible cylindrical member sufficiently so that said splined outer surface of said first flexible cylindrical member nonrotatably engages each of said respective splined interior surfaces of said internally splined members of said first pairing of said first, second and third internally splined members at both ends of the major axis of symmetry of said approximately elliptical first wave generator.

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Abstract

Claims26