Rocker arm assembly for radial and axial loads
View Patent ↗A rocker arm assembly for a valve train of an internal combustion engine which has a rocker arm that pivots on a support pin about an axis where a push rod contacts one end of the assembly and a valve shaft of a gas exchange valve contacts the other end of the assembly. A rocker arm is mounted on a support pin through a radial roller bearing for handling radial forces. An outer bearing support wall is attached to the rocker am and covers both ends of the support pin. Between the ends of the support pin and the outer bearing wall is a thrust washer for handling axial forces in the rocker arm assembly. The radial bearing assembly can have an outer bearing shell and an inner bearing shell where the outer bearing shell has a generally U-shaped configuration that covers the end wall of the support pin. The bottom wall of the outer bearing shell forms the outer bearing support wall for the thrust washer.
1. Rocker arm assembly for use in an internal combustion engine, where the assembly is pedestally mounted on the cylinder head in a push rod style engine, comprising:
a rocker arm, having a horizontal hole through said rocker arm;
a support pin positioned in said horizontal hole;
a radial bearing arrangement positioned between said support pin and said rocker arm in said horizontal hole so as to provide radial rotatable movement to said rocker arm;
an outer bearing wall extending downward from each side of said rocker arm and closing said horizontal hole, said outer bearing support wall forming a cavity between an end wall of the support pin and the outer bearing support wall; and, a thrust washer positioned in each cavity for accommodating axial forces in said rocker arm assembly, said thrust washer contacting the support pin only at an end wall of the support pin.
2. The rocker arm assembly of claim 1 , wherein the outer bearing wall forms and outer bearing shell for the radial bearing arrangement.
3. The rocker arm assembly of claim 1 , wherein the outer bearing wall is separate from the outer bearing shell for the radial bearing arrangement.
4. A bearing assembly for a rocker arm assembly having a rocker arm and a support pin mounted in a hole in the rocker arm, the bearing assembly comprising:
an outer bearing shell having a U-shaped cross section, wherein a side wall of the U-shaped outer bearing shell is affixable to the rocker arm in the hole in the rocker arm;
an inner bearing shell spaced apart from the outer bearing shell and having a U-shaped cross section, wherein a side wall of the U-shaped inner bearing shell is affixable to the support pin, the side wall of the inner bearing shell faces the sidewall of the outer bearing shell and a bottom wall of the inner bearing shell faces a bottom wall of the U-shaped outer bearing shell;
a roller element positioned between the side wall of the inner bearing shell and the side wall of the outer bearing shell; and,
a thrust washer positioned between the bottom wall of the inner bearing shell and the bottom wall of the outer bearing shell.
5. The bearing assembly of claim 4 , wherein the thrust washer is positioned between the bottom wall of the outer bearing shell and the end wall of the support pin and contacts both the end wall of the support pin and the bottom wall of the inner bearing shell.
6. A support pin assembly for a rocker arm of an internal combustion engine, comprising:
a support pin;
a race way positioned in at least one end of said support pin;
an outer bearing shell having a U-shaped cross section, wherein a side wall of the U-shaped outer bearing is positioned opposite said race way and a bottom wall of the U-shaped outer bearing shell is positioned opposite an end wall of the support pin;
a roller element positioned between the side wall of the outer bearing shell and the race way; and,
a thrust washer positioned between the bottom wall of the outer bearing shell and the end wall of the support pin, said thrust washer contacting the support pin only at an end wall of the support pin.
7. A bearing assembly for a rocker arm assembly having a rocker arm and a support pin mounted in a hole in the rocker arm, the bearing assembly comprising:
an outer wall, extending from one bottom wall of the rocker arm assembly to another bottom wall of the rocker arm assembly, covering the hole in the rocker arm assembly wherein a side wall of the outer wall is affixable to the rocker arm on an outer surface of the rocker arm;
an inner bearing shell spaced apart from the outer bearing shell wherein a side wall of the-inner bearing shell is affixable to the support pin, a bottom wall of the inner bearing shell faces a bottom wall of the U-shaped outer bearing shell;
a separately formed outer bearing shell positioned on the inner surface of the hole in the rocker arm assembly;
a roller element positioned between the side wall of the inner bearing shell and the side wall of the outer bearing shell; and,
a thrust washer positioned between the bottom wall of the inner bearing shell and the bottom wall of the outer bearing shell.