Wrist pin
AssigneeFederal-Mogul World Wide, Inc.
InventorsRoberto B. Nigro, Randall R. Gaiser, Eduardo Matsuo, Eric A. Highum
Life of this patent
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Abstract
A wrist pin for a heavy-duty piston assembly has a body with an axis of rotation and a generally cylindrical outer surface. The outer surface is adapted for pivotal connection to both a pair of laterally spaced pin bores and a small end of a connecting rod generally between the pin bores. The outer surface has a surface roughness equal to or less than 0.10 μm. The outer surface has a Kurtosis value that is inversely proportional with the surface roughness such that a product of the Kurtosis value and the surface roughness is between about 0.30 μm to 0.60 μm. The outer surface has a skewness of about −1.0 to 0.0 and a lay angle relative to the axis of about 85 to 95 degrees.
Claims5
A piston assembly, comprising:
- a piston having a wrist pin bore;
- a connecting rod having a wrist pin bore;
- and
- a wrist pin receivable in said bores to connect said piston to said connecting rod, said wrist pin having an outer surface roughness no greater than 0.10 μm, a Kurtosis value that is inversely proportional to said surface roughness such that the product of said Kurtosis value and said surface roughness is between about 0.3 μm to 0.6 μm, a skewness of about −1.0 to 0.0, and a lay angle relative to an axis of said wrist pin of 85 to 95 degrees.
A wrist pin for joining a connecting rod to a piston, said wrist pin comprising:
- a generally cylindrical wrist pin body having a central longitudinal axis and a outer surface;
- and
- wherein said outer surface is characterized by having an outer surface roughness of no greater than 0.10 μm, a Kurtosis value that is inversely proportional to the surface roughness such that the product of the Kurtosis valve and the surface roughness is between 0.3 μm and 0.60 μm, a skewness of about −1.0 to 0.0 and a lay angle relative to the axis of rotation of about 85 to 95 degrees.
Dependencies are inferred from the claim text.