Abstract: A specially profiled wax retaining cup and piston guide are crimped together to compress a peripheral portion of a diaphragm wax seal to the extent of extruding the diaphragm material to form both an axial seal and at least one radial seal. The compressed, extruded diaphragm seal provides a wax containment seal capable of withstanding high wax pressures that generate high actuation forces. A wax filled thermal actuator reliably produces an actuating force F sufficient to lift a load in a range of 2500 to 6000 times the mass of the actuator. Performance of the thermal actuator may also be expressed in terms of the internal pressures generated and delivered to the bottom of the actuator piston. The pressure applied to the bottom of the actuator piston in the inventive actuator is in the range of approximately 1700 to 8800 psi (124 to 620 kg/cm2).

Abstract: A thermal flow control valve uses a cylindrical valve sleeve in a stepped bore to regulate fluid flow between an inlet and an outlet. A wax filled actuator is coupled to the valve sleeve to move the sleeve from an open position in which radial flow openings in the sleeve communicate with a larger diameter portion of the stepped bore to a closed position in which the radial flow openings are closed by a sleeve chamber closely surrounding the sleeve. A flow-through end cap closes one end of the stepped bore and provides an axially aligned fixed stop for the actuator piston. Two-way, three-way and mixing embodiments of the valve are disclosed.