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:
Mar. 19, 2019
Filed:
Feb. 15, 2017
Schaeffler Technologies Ag & Co. KG, Herzogenaurach, DE;
John Stallmann, Washington, MI (US);
Schaeffler Technologies AG & Co. KG, Herzogenaurach, DE;
Abstract
A hydraulic fluid system for a variable valve train system is provided that allows hydraulic fluid flow from a high pressure chamber to a medium pressure chamber during a higher pressure phase after a control valve closes. The hydraulic fluid system includes a housing defining (a) the middle pressure chamber which is connected to a hydraulic fluid supply, and (b) the high pressure chamber which contains hydraulic fluid that is pressurized by a pump piston assembly configured to engage a rotating cam. A control valve selectively provides a first flowpath for hydraulic fluid between the middle pressure chamber and the high pressure chamber. A bypass valve selectively provides a second flowpath for hydraulic fluid between the middle pressure chamber and the high pressure chamber based on a pressure of the hydraulic fluid in the high pressure chamber.