The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 1999
Filed:
Jul. 10, 1997
Thomas A Immel, Malone, WI (US);
Erik J Christiansen, Cedarburg, WI (US);
Tecumseh Products Company, Tecumseh, MI (US);
Abstract
An overhead camshaft internal combustion engine having a plastic camshaft which extends through an opening on the cylinder head, the plastic camshaft having a seal ring disposed around the outer surface of the molded plastic camshaft to provide an interface surface for contacting a seal assembly disposed between the engine casing and the molded plastic camshaft. The seal assembly and the seal ring provide a fluid tight seal to prevent leakage of fluid through the cylinder head opening. The seal ring provides a smooth contact surface for the molded plastic camshaft to prevent wear and damage to the seal assembly from the abrasive surface of the molded plastic camshaft. The seal ring also provides a heat sink for dissipating the frictional heat generated by the rotation of the camshaft. In another form, the plastic camshaft includes a powder metal surface formed thereon. The powder metal surface provides the same benefits as the seal ring, namely protection from wear and dissipation of heat. The seal ring or the powder metal surface may advantageously be extended to include the portion of the molded plastic camshaft in contact with a journal bearing.