An orthoplanar spring for a hydraulic tensioner which has a flat, closed position, in which a flat center portion of the orthoplanar spring seals the inlet hole between the oil supply and the high pressure chamber of the tensioner and an open deformed position in which the flat center portion of the orthoplanar spring moves a distance to unseal the inlet hole such that fluid flows from the inlet supply through the openings in the orthoplanar spring and around the flat center portion to the high pressure chamber.

A check valve assembly includes a valve frame, a valve poppet, a first torsion spring, and a second torsion spring. The valve frame has an opening. The valve poppet is positionable in the opening. The valve poppet is moveable in a first direction to close the check valve assembly and moveable in a second direction to open the check valve assembly. The first torsion spring biases the valve poppet in the first direction. The second torsion spring biases the valve poppet in the first direction before the valve poppet has traveled a threshold distance. The second torsion spring biases the valve poppet in the second direction after the valve poppet has traveled the threshold distance.

A check valve may include: a check seat defining a flow path and including downstream and upstream sides; a poppet assembly including a poppet body and a poppet seat, the poppet seat configured to form a fluid-tight seal with the downstream side; at least one first extension extending upstream from the poppet body and including a roller; and at least one cam arm disposed at least partially upstream of the poppet body and the check seat and configured to engage with the at least one roller; and at least one cam arm disposed at least partially upstream of the poppet body and the check seat and configured to engage with the at least one roller. Engagement between the at least one cam arm and the at least one roller is configured to urge the poppet in the upstream direction.