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:
Feb. 02, 1999
Filed:
Mar. 31, 1998
Ina Walzlager Schaeffler oHG, , DE;
Abstract
A device for varying the valve timing of gas exchange valves of an internal combustion engine comprising a driven unit (3) rotationally fixed to a camshaft (2), and a drive unit (6) which is in driving relationship through a traction element with a crankshaft while being rotatably mounted on the driven unit (3), the device (1) further comprising at least two pressure chambers (11, 12) that can be pressurized by a hydraulic pressure medium, the hydraulic pressure medium being fed into the device (1) through a connecting bracket (13) which is rotationally fixed to the driven unit (3) and coaxially surrounds the end portion of the camshaft (2) while comprising on its outer peripheral surface (16), a plurality of annular flanges (29, 30, 31) having sealing rings (20, 21, 22) arranged in annular grooves (17, 18, 19), which annular flanges (29, 30, 31) are sealingly surrounded by a reception bore (36) in a connecting structure (35), characterized in that the sealing rings (20, 21, 22) either comprise an elastic coating (34a) at least on an outer peripheral surface (23, 24, 25) and are sealingly force-locked through this coated outer peripheral surface (23, 24, 25) with the reception bore (36) in the connecting structure (35), or the sealing rings (20, 21, 22) comprise a wear-reducing coating (34b) at least on an outer peripheral surface (23, 24, 25) and are in a sealed sliding relationship through this coated outer peripheral surface (23, 24, 25) with the reception bore (36) in the connecting structure (35).