Patent ID: 8528697

Claim:
A passive fluid temperature controller comprising, in combination, a housing, a sump in said housing for receiving fluid, a gear supported for rotation in said housing and in contact with said fluid in said sump, a bi-thermal element encircling greater than one quarter of a diameter of said gear having a first layer of a material having a higher coefficient of thermal expansion and a second layer of a second material having a lower coefficient of thermal expansion, wherein said bi-thermal element includes at least a first position at a first temperature and a second position at a second temperature that is higher than said first temperature, and wherein said bi-thermal element is continuously positionable between said first and second positions by thermal expansion and contraction of said first and second layers of material as a temperature of said bi-thermal element moves between said first and said second temperatures, and wherein said bi-thermal element directs an increasing amount of said fluid towards said housing as said bi-thermal element moves from said first position to said second position; wherein the said bi-thermal element is attached to the interior of the sump at a single point on a proximate end of the said bi-thermal element.