Dynamic locking and releasing cam lobe

Abstract

Disclosed is a method and system for intermittently operating poppet valves in an internal combustion engine when desired by the selective locking or unlocking of one or more cam lobes with the camshaft. One or more cam lobes, with a small radial clearance, ride on a camshaft such that an engagement mechanism may be activated as desired to lock the cam lobe to the camshaft, thereby activating the respective poppet valve. The cam lobe is prevented from moving axially to ensure correct alignment with a follower. A suitable holding device may be used to ensure the non-activated cam lobes are restrained at a suitable orientation relative to the cam follower.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A cam driven reciprocating internal combustion engine comprising:
 a rotating cam shaft comprising a groove in mechanical communication with a plurality of cam lobes, each said cam lobe that is mechanically coupled to and controls the operation of an intake valve and/or an exhaust valve associated with a respective cylinder of said internal combustion engine, and each cam lobe comprising a key way slot and a tapered portion extending along an interior diameter to said key way slot;   at least one coupler that selectively couples said rotational force of said cam shaft to said at least one respective cam lobe, said coupler comprising a key that sits in said groove and is engageable with said keyway.   
     
     
         2 . The cam driven reciprocating internal combustion engine of  claim 1 , wherein said cam lobe further comprises a groove on the inside portion of said cam lobe that contacts said camshaft and said camshaft comprises a fastener that fits within said groove disallowing said cam lobe from drifting axially on said camshaft during operation. 
     
     
         3 . The cam driven reciprocating internal combustion engine of  claim 1 , further comprising an actuation mechanism connected to said coupler, said actuation mechanism providing axial forces to said coupler. 
     
     
         4 . The cam driven reciprocating internal combustion engine of  claim 1  wherein said actuation mechanism is further connected to an actuation mechanism that may be hydraulic, pneumatic or electromagnetic, and may include return spring(s). 
     
     
         5 . A method of deactivating one or more valves from undergoing gas exchange during the operation of an internal combustion engine comprising the steps:
 providing a cam driven reciprocating internal combustion engine comprising:   a cylinder block defining a plurality of cylinders, each said cylinder in mechanical communication with a respective cam driven intake valve and/or exhaust valve;   rotating a cam shaft in mechanical communication with at least one selectively disengageable cam lobe that sits via a groove on the interior of said cam lobe on a fastener attached to the camshaft thereby controlling the operation of said respective intake valve and/or said respective exhaust valve;   providing at least one coupler that selectively couples and decouples said rotational force of said camshaft to said at least one respective cam lobe, said coupler comprising a key that sits in a groove of said camshaft;   connecting said coupler to an actuation mechanism;   deactivating said respective valve by signaling said actuation mechanism to move from said cam lobe causing a key of said coupler to disengage from a keyway in said cam lobe in a first mode;   activating said respective valve by signaling said actuation mechanism to move toward said cam lobe causing a key of said coupler to engage said keyway in said cam lobe in a second mode.