FIELD

The present disclosure relates to thermal bypass systems, and more particularly, to a thermal bypass valve including a bimetallic disc.

BACKGROUND

Thermal bypass valves and systems are used in automobiles and other vehicles that require cooling of fluid. Thermal bypass systems are arranged to divert fluid, such as transmission fluid, antifreeze or other coolant fluid (e.g., battery cooling fluid), oil, etc., to either a component to be cooled (e.g., transmission, battery, radiator, etc.) or a cooler. If the temperature of the fluid is less than a predetermined temperature, the thermal bypass system diverts the fluid to the component to be cooled. If the fluid exhibits a temperature that is greater than or equal to the predetermined temperature, the thermal bypass system diverts the fluid to the cooler.

Current thermal bypass systems utilize wax actuators, for example, in sliding spool type valves. A wax actuator uses paraffin wax arranged within a piston. As the wax increases in temperature it expands, thereby expanding the cylinder, and as the wax decreases in temperature it contracts, and a spring returns the cylinder to its original position (i.e., contracts the cylinder). Thermal bypass systems utilize these wax actuators to shift an output in a fluid tube. For example, the system may include a tube including a first end, a second end, and a first hole in the side wall between the first end and the second end. The tube is slidingly and concentrically arranged with respect to a second tube, the second tube including a second side wall hole and a third side wall hole arranged adjacent each other. When the fluid temperature is greater than or equal to a predetermined temperature, the wax actuator expands and shifts the first tube such that the first hole is aligned with the third hole, thereby diverting fluid to a cooler. In other words, current spool designs embody a spool that moves to block/unblock passages in the wall of the bore. When the fluid temperature is less than the predetermined temperature, the wax actuator contracts and shifts the first tube such that the first hole is aligned with the second hole, thereby diverting fluid to a component to be cooled. However, there are significant problems with such design. If, for example, debris gather between the first tube and the second tube, the tubes will no longer easily slide with respect to each other, or get stuck. If the tubes no longer slide, then fluid may not get cooled causing catastrophic failure in a component to be cooled. In fact, sliding spool type valves driven by a thermal element (e.g., wax actuator) and return by spring pressure often fail in a bypass mode, which is not desirable because fluid is prevented from flowing to the cooler (i.e., fluid temperature continues to rise leading to failure of other system components). Also, if the tubes get stuck together, the wax actuator/piston cylinder will not be able to expand; however, the wax will continue to expand and cause the wax actuator to fail, lose wax/stroke, expand and lose calibration, or explode and destroy a component, for example, the transmission. Furthermore, wax elements have a short life expectancy, for example, only 30,000 cycles.

Thus, there has been a long-felt need for a thermal bypass valve system that efficiently diverts fluid based on its temperature, has a longer life expectancy, and, in the event of failure, does not result in any damage to other elements.

SUMMARY

According to aspects illustrated herein, there is provided a thermal bypass valve for diverting fluid, comprising an inlet, a chamber in fluid communication with the inlet, a bimetallic disc pivotably arranged in the chamber, a first outlet in fluid communication with the chamber, and a second outlet in fluid communication with the chamber, wherein the bimetallic disc is operatively arranged to, in a first state, divert fluid to the first outlet, and in a second state, when the fluid reaches a predetermined temperature, divert the fluid to the second outlet.

In some embodiments, the thermal bypass valve further comprises a pressure relief valve fluidly arranged between the inlet and the first outlet. In some embodiments, the pressure relief valve comprises a spring and a ball. In some embodiments, the thermal bypass valve further comprises a check valve fluidly arranged between the second outlet and the first outlet. In some embodiments, the check valve comprises a ball idly arranged in a check valve passage. In some embodiments, the chamber is wedge shaped. In some embodiments, the chamber comprises a first curvilinear surface and a second curvilinear surface directed toward the first curvilinear surface. In some embodiments, the chamber further comprises a first lip extending from the first curvilinear surface, and a second lip extending from the second curvilinear surface, wherein a passage is formed between the first lip and the second lip. In some embodiments, the first curvilinear surface comprises a first radius, the second curvilinear surface comprises a second radius, and the bimetallic disc comprises a third radius, the third radius being greater than the first radius and the second radius. In some embodiments, in a third state, the bimetallic disc is operatively arranged to divert fluid to both the first outlet and the second outlet.

According to aspects illustrated herein, there is provided a thermal bypass valve for diverting fluid, comprising a first inlet, a chamber in fluid communication with the inlet, a bimetallic disc pivotably arranged in the chamber, a first outlet in fluid communication with the chamber, a second inlet in fluid communication with the first outlet, and a second outlet in fluid communication with the chamber, wherein the bimetallic disc is operatively arranged to in a first state, divert fluid to the first outlet, and in a second state, when the fluid reaches a predetermined temperature, divert the fluid to the second outlet.

In some embodiments, the thermal bypass valve further comprises a pressure relief valve fluidly arranged between the first inlet and the first outlet, the pressure relief valve being biased toward a sealed position. In some embodiments, the thermal bypass valve further comprises a check valve fluidly arranged between the second outlet and the second inlet. In some embodiments, the check valve comprises a check valve passage and a ball idly arranged in the check valve passage. In some embodiments, the chamber is wedge shaped. In some embodiments, the chamber comprises a first curvilinear surface, and a second curvilinear surface directed toward the first curvilinear surface. In some embodiments, the chamber further comprises a first lip extending from the first curvilinear surface, and a second lip extending from the second curvilinear surface, wherein a passage is formed between the first lip and the second lip. In some embodiments, the first curvilinear surface comprises a first radius, the second curvilinear surface comprises a second radius, and the bimetallic disc comprises a third radius, the third radius being greater than the first radius and the second radius. In some embodiments, the chamber and the first inlet are linearly aligned.

In some embodiments, the first inlet is linearly aligned with the chamber due to inserts located below a mating surface of the inferior component. In some embodiments, the first inlet is linearly aligned with the chamber due to an appendage or boss from the superior component extending into a hole in the inferior component, the appendage or boss forming the top of the chamber.

According to aspects illustrated herein, there is provided a thermal bypass valve for diverting fluid, comprising an inlet, a wedge-shaped chamber in fluid communication with the inlet, a bimetallic disc arranged in the chamber, a first outlet in fluid communication with the chamber, a second outlet in fluid communication with the chamber, and a check valve fluidly arranged between the first outlet and the second outlet, wherein the bimetallic disc is operatively arranged to in a first state, divert fluid to the first outlet, and in a second state, when the fluid reaches a predetermined temperature, divert the fluid to the second outlet.

According to aspects illustrated herein, there is provided a thermal bypass valve comprising a bimetallic disc. The bimetallic disc is arranged in a space between a superior component and an inferior component and switches from side to side depending on temperature. In a first state, the bimetallic disc is displaced downward toward the inferior component, which allows fluid (e.g., transmission fluid) to flow from the inlet, past the bimetallic disc valve and up through the outlet to the transmission/pump/tank. In a second state, the bimetallic disc is displaced upward toward the superior component, which forces the transmission fluid to flow downward and then to the cooler before circling back around to the outlet and to the transmission/pump/tank. The bimetallic disc displaces or bends when the temperature of the fluid reaches a certain level. In essence, the fluid continues to flow and cycle through the component (e.g., transmission) until it gets too hot, at which point the bimetallic disc displaces and forces the fluid through the cooler. Once the temperature of the fluid is reduced, the bimetallic disc displaces/bends/switches back to the original down position. It should be appreciated that the fluid flow may also assist in the disc's travel (i.e., up and down).

According to aspects illustrated herein, there is provided a thermal bypass valve, comprising an inlet, a chamber, a bimetallic disc arranged in the chamber, a first outlet, and a second outlet, wherein the bimetallic disc is operatively arranged to divert fluid to the first outlet, and when the fluid reaches a preset temperature, divert the fluid to the second outlet. In some embodiments, the thermal bypass valve further comprises a pressure relief valve fluidly arranged between the inlet and the first outlet. In some embodiments, the pressure relief valve comprises a spring and a ball.

These and other objects, features, and advantages of the present disclosure will become readily apparent upon a review of the following detailed description of the disclosure, in view of the drawings and appended claims.

