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. 22, 2015
Filed:
Mar. 29, 2012
Junichi Takahashi, Saitama, JP;
Takashi Ono, Saitama, JP;
Gyo Muramatsu, Niigata, JP;
Takayuki Ichikawa, Niigata, JP;
Junichi Takahashi, Saitama, JP;
Takashi Ono, Saitama, JP;
Gyo Muramatsu, Niigata, JP;
Takayuki Ichikawa, Niigata, JP;
KABUSHIKI KAISHA RIKEN, Tokyo, JP;
Abstract
A multi-piece oil ring is provided in which, even after long-term operation of an engine, adhesion and deposition of oil sludge are prevented, sticking of components does not occur, and a high oil control function can be maintained. The multi-piece oil ring includes a spacer expander and a pair of upper and lower side rails supported by the spacer expander. To achieve the above features, at least side faces of the side rails that face the spacer expander are coated with a fluorine-containing coating, and the spacer expander is coated with a metal coating. The angle of contact (θ) of a paraffin-based lubricating oil with the portions of the side rails at 150° C. that are coated with the fluorine-containing coating is 50° or larger, and the angle of contact (θ) of the paraffin-based lubricating oil with the portion of the spacer expander at 150° C. that is coated with the metal coating is 10 to 50°. The difference between θand θ(θ−θ) is 30° or larger.