High stiffness low mass rocker arm

Abstract

A cam-follower rocker arm is provided comprising a flat single plate body containing an axle that extends perpendicular from the vertical wall area for making contact with a valve and a second pivot point axle. The pivot point for the cam-follower rocker arm may be located centrally or at the end of the cam-follower rocker arm that is opposite the cam-follower rocker arm valve arm. An external cam-follower bearing is mounted on the axle and extends on each side of the flat plate wall. The cam-follower rocker arm of the invention is characterized by a relatively reduced mass and has a stiffness that exceeds limits achieved by known prior art designs for an overhead cam and cam-follower valve train; the gain in stiffness being attributed to the body's flat plate cross-section relative to conventional prior art cam-follower rocker arms that have a U-shape or a dual wall cross-section.

1 . A cam-follower rocker arm characterized by relatively high stiffness and low mass comprising:
 a. a flat plate rocker arm body having a valve end, a mounting pivot and a cam-follower bearing point;   b. the cam-follower bearing point comprising an axle positioned transversely through said axle having an extension on either side of the body;
 i. a rotatable cam-follower bearing mounted on said axle and extending from each of the sides of the lever; 
 ii. bearing plates mounted on said axle outboard of each of said cam-follower bearings to retain the cam-follower bearings on the axle; and 
 iii. a retaining pin for securing said cam-follower bearings and bearing plates to provide an integrated cam-follower rocker arm assembly. 
   
   
   
       2 . The cam-follower rocker arm of  claim 1  wherein the cam-follower bearing is centrally located on the cam-follower rocker arm. 
   
   
       3 . The cam-follower rocker arm of  claim 1  wherein the cam-follower is located at one end of the cam-follower rocker arm. 
   
   
       4 . The cam-follower rocker arm of  claim 1  in which the transversely positioned axle is provided with circumventing needles over which said cam-follower bearing are mounted to reduce bearing friction. 
   
   
       5 . The cam-follower rocker arm of  claim 2  in which one end of the flat plate body is provided with a pivot end and the opposite end of said body is provided with a valve pad. 
   
   
       6 . The cam-follower rocker arm of  claim 3  in which one end of the flat plate body is provided with a pivot end and the opposite end of said body is provided with a valve pad. 
   
   
       7 . The cam-follower rocker arm of  claim 5  wherein the pivot end comprises a generally concave configuration.