Camshaft and follower geometry

Abstract

An internal combustion engine includes a camshaft with a lobe rotatable about a camshaft axis and a follower and which follows the lobe and is reciprocated along a follower axis by the lobe. A contact force is generated between the lobe and the follower such that the contact force is cyclic between a minimum contact force and a maximum contact force. The follower axis is offset from the camshaft axis such that the lobe contacts the follower at a contact point that is substantially aligned with the follower axis when the maximum contact force is generated between the lobe and the follower. In this way, the side load on the follower is minimized.

We claim: 
     
         1 . An internal combustion engine comprising:
 a camshaft having a lobe rotatable about a camshaft axis; and   a follower which follows said lobe and is reciprocated along a follower axis by said lobe whereby a contact force is generated between said lobe and said follower such that said contact force is cyclic between a minimum contact force and a maximum contact force;   wherein said follower axis is offset from said camshaft axis such that said lobe contacts said follower at a contact point that is substantially aligned with said follower axis when said maximum contact force is generated between said lobe and said follower, thereby minimizing side load on said follower.   
     
     
         2 . An internal combustion engine as in  claim 1  wherein said follower reciprocates within and is guided by a follower bore. 
     
     
         3 . An internal combustion engine as in  claim 1  wherein reciprocating motion of said follower is translated to a pumping plunger which reciprocates within a plunger bore. 
     
     
         4 . An internal combustion engine as in  claim 3  wherein said plunger bore is in fluid communication with a pumping chamber and reciprocation of said pumping plunger pressurizes fuel within said pumping chamber. 
     
     
         5 . An internal combustion engine as in  claim 4  wherein said follower reciprocates within and is guided by a follower bore. 
     
     
         6 . An internal combustion engine as in  claim 5  wherein said follower bore is coaxial with said plunger bore.