Combined oil control ring

Patent metadata

Field	Value
Publication number	US-9410625-B2
Application number	US-201214351393-A
Country	US
Kind code	B2
Filing date	Oct 10, 2012
Priority date	Oct 14, 2011
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

To provide a combined oil control ring with a function of preventing the separate rotation of side rails for a long period of time even under fretting fatigue, seating tabs of a spacer expander are provided with substantially longitudinal projections and recesses on their side-rail-pushing surfaces in a circumferential direction, the width m of a bottom surface being larger than the circumferential length m′ of the top surface in each projection, and a surface connecting the top surface to a recess surface having a bulging shape.

First claim

What is claimed is:

1. A combined oil control ring comprising two upper and lower side rails, and a spacer expander sandwiched thereby,
said spacer expander having seating tabs on the inner side for pushing inner surfaces of said side rails;
a side-rail-pushing surface of each of said seating tabs having a plurality of substantially longitudinal projections and recesses, the projections and recesses alternately arranged in a circumferential direction;
the width m of a bottom surface being larger than the circumferential length m′ of a top surface in each projection; and
a surface connecting said top surface of each projection to said recess surface having a bulging shape.

2. The combined oil control ring according to claim 1 , wherein said top surface of each projection is substantially in parallel to said side-rail-pushing surface.

3. The combined oil control ring according to claim 1 , wherein said top surface of each projection is inclined from said side-rail-pushing surface.

4. The combined oil control ring according to claim 3 , wherein the inclination angle
of said top surface of each projection is in a range of 1-30°.

5. The combined oil control ring according to claim 3 , wherein a ratio (h/m) of the height h of said top surface from said recess surface to the width m of the bottom surface of said projection is 0.5-10%.

6. The combined oil control ring according to claim 1 , wherein the height h of said top surface from said recess surface is 0.5-20 μm.

7. The combined oil control ring according to claim 3 , wherein the height h of said top surface from said recess surface is 0.5 μm or more and less than 6 μm.

8. The combined oil control ring according to claim 3 , wherein the total circumferential length of said top surfaces of projections in said seating tab is 30-70% of the circumferential length of said seating tab.

9. The combined oil control ring according to claim 3 , wherein the total circumferential length of said top surfaces of projections in said seating tab is 20-50% of the circumferential length of said seating tab.

10. The combined oil control ring according to claim 3 , wherein the total circumferential length of said top surfaces of projections in said seating tab is 15-25% of the circumferential length of said seating tab.

Assignees

• Kk Riken

Inventors

• Nakazawa Masahiro
• Watanabe Tadahiko
• Koizumi Satoshi

Classifications

• F16J9/12 Primary

  Details · CPC title

• F16J9/068 Primary

  corrugated in the axial direction · CPC title