Patent ID: 8128377

Claim:
A split-pressure hydraulic fluid supply circuit for a multi-speed transmission having a power source and at least one hydraulic fluid reservoir, the split-pressure hydraulic fluid supply circuit comprising: a first pump having an inlet port and an outlet port, the first pump being operatively connected to the power source and providing a fixed flow of pressurized hydraulic fluid; a second pump having an inlet port, an outlet port, and a regulator port, the second pump being operatively connected to the power source and providing a variable flow of pressurized hydraulic fluid; a low-pressure circuit portion including a low-pressure work circuit directly connected to the outlet port of the first pump for supplying low-pressure hydraulic fluid to the multi-speed transmission; a high-pressure circuit portion including a high-pressure work circuit directly connected to the outlet port of the second pump for supplying high-pressure hydraulic fluid to the multi-speed transmission, wherein the high-pressure work circuit and the low-pressure work circuit are separate, characterized by an absence of a fluid coupling between the two circuits; wherein the low-pressure work circuit is not fluidly coupled to the second pump; and wherein the high-pressure work circuit is not fluidly coupled to the first pump.