Patent number: 8337345

Sliding rack ratchet tensioner

Original Assignee: BorgWarner Inc.

Field of technology: Vehicles, Engines and Transportation

Patent granted on: Tue, 25 Dec 2012

Patent drawing

Abstract

The high-performance sliding rack ratchet tensioner is inexpensively manufactured. A rack having rack teeth is slidingly received in a rack slot on the side of the piston. The rack slot is preferably open-ended on the end facing the tensioner arm. The rack and piston are both received in a piston bore in the tensioner body. The rack length is preferably shorter than the rack slot length to provide backlash. A pawl mounted in a pawl bore perpendicular to the rack bore engages the rack. The open-ended rack slot allows the rack to be inserted after the piston during assembly. The rack and pawl preferably have shark fin-shaped teeth. The pawl preferably has dummy teeth to ensure that the load is shared by the center teeth.