US 12,129,925 B2
Variable tune hydraulic tensioner
Fenton O'Shea, Ithaca, NY (US); and Michael Smart, Groton, NY (US)
Assigned to BorgWarner, Inc., Auburn Hills, MI (US)
Appl. No. 18/548,434
Filed by BorgWarner, Inc., Auburn Hills, MI (US)
PCT Filed Mar. 2, 2021, PCT No. PCT/US2021/020426
§ 371(c)(1), (2) Date Aug. 30, 2023,
PCT Pub. No. WO2022/186823, PCT Pub. Date Sep. 9, 2022.
Prior Publication US 2024/0133451 A1, Apr. 25, 2024
Prior Publication US 2024/0229903 A9, Jul. 11, 2024
Int. Cl. F16H 7/08 (2006.01)
CPC F16H 7/0836 (2013.01) [F16H 2007/0808 (2013.01); F16H 2007/0814 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A hydraulic tensioner comprising:
a tensioner body defining a bore having a first end and a second end separated by a length, the second end being in fluid communication with a source of pressurized fluid through an inlet;
at least one radial hole along the length of the bore of the tensioner body between the first end and the second end of the bore;
a hollow piston slidably received within the bore, the piston having a first end and a second end separated by a length;
at least one radial cross drilled vent hole along the length of the piston;
a hydraulic pressure chamber defined by the hollow piston and the bore of the tensioner body;
a piston spring received within the hydraulic pressure chamber for biasing the piston away from the inlet; and
wherein as the piston moves within the bore of the tensioner body to at least one position in which the at least one radial cross drilled vent hole aligns with the at least one radial hole along the length of the bore of the tensioner body, venting fluid from the hydraulic pressure chamber, such that the damping of the hydraulic tensioner increases at the at least one position.