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:
May. 28, 2002
Filed:
Oct. 30, 2000
Takeo Otani, Fukushima, JP;
Freudenberg-Nok General Partnership, Plymouth, MI (US);
Abstract
The oil seal of the present invention for a valve stem includes a triple seal lip having a cam chamber side lip, a first combustion chamber side lip and a second combustion chamber side lip. Notches are provided on the second combustion chamber side lip and other notches are provided on the first combustion chamber side lip. These notches permit flow communication from the cam chamber side with the combustion chamber side. The notches provided on the combustion chamber side lip and the notches provided on the second combustion chamber side lip are placed circumferentially shifted from each other so that the notches are not axially aligned relative to the notches. Preferably, the non-notched portion is axially aligned and spaced apart relative to the notched portion. Similarly, the notched portion is axially spaced relative to the non-notched portion, such that when the valve stem moves eccentrically toward the notch on the combustion chamber side lip, the second combustion chamber side lip prevents the eccentric motion of the valve stem. When the valve stem moves eccentrically toward the notch on the second combustion chamber side lip, the combustion chamber side lip prevents the eccentric motion of the valve stem. Therefore, when compared to a conventional oil seal for the valve stem, the eccentric movement of the valve stem can be considerably reduced and the variance in the amount of oil leaking or migrating due to the eccentric movement of the valve stem, from the cam chamber side to the combustion chamber side, can be considerably reduced. Furthermore, the eccentric movement of the valve stem is reduced compared to a conventional stem, so that the wear of the oil seal of the present invention can be considerably reduced to attain stable oil migration during operation.