Integral inlet and pressure relief valve for an automotive tensioner
AssigneeBorg-Warner Automotive, Inc.
InventorsRoger T. Simpson, Kevin B. Todd
Life of this patent
Estimating the term…
Abstract
A hydraulic tensioner is provided with a plunger slidably fitted in a cavity in the tensioner housing and biased in a protruding direction by a spring and fluid. An integral inlet check and pressure relief valve is positioned in the cavity and permits fluid to only flow into the cavity and thereby protrude the plunger but not out of the cavity until a high pressure condition is reached whereupon fluid is relieved out of the cavity back to the fluid source. The integral inlet check and pressure relief valve includes a check spring biasing a valve member a against a pressure relief disk that is biased against the valve member by a pressure relief spring.
Claims20
A hydraulic tensioner for a wrapped power transmission device between two rotating members, comprising:
- a housing with a fluid chamber, said chamber communicating with an external source of pressurized fluid;
- a plunger positioned within said chamber and capable of extending therefrom for bearing against a power transmission device to regulate tension between said rotating members;
- a spring member biasing said plunger in a direction extending from said chamber;
- and
- an integral inlet check and pressure relief valve positioned to allow the transfer of pressurized fluid from said source of pressurized fluid to said chamber and to block the transfer of fluid from said chamber to said source of pressurized fluid at a first predetermined pressure condition in said chamber, but permit transfer of fluid from said chamber to said source of pressurized fluid at a second higher predetermined pressure condition in said chamber, said integral inlet check and pressure relief valve including an inlet check valve seat ring having a first side, a second side and an orifice, said seat ring fixed relative to said housing, a valve member disposed proximate to said first side of said seat ring, an inlet check spring biasing said valve member toward said seat ring first side, a pressure relief disk having an orifice, said relief disk disposed proximate to said second side of said seat ring opposite said valve member, and a pressure relief spring biasing said pressure relief disk toward said seat ring second side.
A hydraulic chain tensioner comprising:
- a housing having a fluid chamber;
- a plunger slidably received within the fluid chamber;
- a spring biasing the plunger in a first direction extending from the fluid chamber;
- and
- an integral inlet check and pressure relief valve disposed in the fluid chamber including an inlet check valve member, a check spring biasing said valve member in a second direction, said second direction opposite of said first direction, a pressure relief disk disposed proximate to said valve member, and a pressure relief spring biasing said relief disk in the first direction toward said valve member.
Dependencies are inferred from the claim text.