System and method for controlling pump performance in a transmission

A hydraulic system of a transmission, comprising:

• a controller;
• a variable displacement pump adapted to be driven by a torque-generating mechanism, the pump having an inlet and an outlet, where the pump is configured to generate fluid flow and pressure throughout the system;
• a lube circuit fluidly coupled to the pump;
• a lube regulator valve disposed in the lube circuit, the lube regulator valve being configured to move between at least a regulated position and an unregulated position, where the regulated position corresponds to a regulated pressure in the lube circuit;
• a pressure switch fluidly coupled to the lube regulator valve and configured to move between a first position and a second position, where the switch is disposed in electrical communication with the controller;
• and
• a solenoid disposed in electrical communication with the controller, the solenoid controllably coupled to the pump to alter the displacement of the pump,
• wherein, once the fluid pressure in the lube circuit reaches a substantially regulated condition, the lube regulator valve moves from the unregulated position to the regulated position,
• wherein, the pressure switch is configured to detect the movement of the lube regulator valve between the regulated position and unregulated position;
• and
• the pressure switch moves between the first position and the second position upon movement of the lube regulator valve, wherein
• the movement of the pressure switch between the first position and second position induces a signal triggered to the controller;
• and
• the controller controllably actuates the solenoid based on the signal.

A hydraulic system of a transmission, comprising:

• a controller;
• a variable displacement pump adapted to be driven by a torque-generating mechanism, the pump having an inlet and an outlet, where the pump is configured to generate fluid flow and pressure throughout the system;
• a lube circuit fluidly coupled to the pump;
• a lube regulator valve disposed in the lube circuit, the lube regulator valve being configured to move between at least a regulated position and an unregulated position, where the regulated position corresponds to a regulated pressure in the lube circuit;
• a pressure switch fluidly coupled to the lube regulator valve and configured to move between a first position and a second position, where the switch is disposed in electrical communication with the controller;
• and
• a solenoid disposed in electrical communication with the controller, the solenoid controllably coupled to the pump to alter the displacement of the pump;
• and
• further comprising a temperature sensor disposed in electrical communication with the controller, the temperature sensor adapted to detect a temperature of the fluid in the transmission.

A method of controlling fluid flow through a transmission, the transmission including a controller, a variable displacement pump having an inlet and an outlet, a main circuit fluidly coupled to the pump, a lube circuit fluidly coupled to the pump and main circuit, a main regulator valve, a lube regulator valve, a pressure switch, and a solenoid, the method comprising:

• pumping fluid from the pump into the main circuit until the fluid pressure in the main circuit reaches a first regulation point;
• fluidly actuating the main regulator valve from an unregulated position to a regulated position when the fluid pressure in the main circuit reaches the first regulation point;
• pumping fluid into the lube circuit until the fluid pressure in the lube circuit reaches a second regulation point;
• fluidly actuating the lube regulator valve from an unregulated position to a regulated position when the fluid pressure in the lube circuit reaches the second regulation point;
• moving the pressure switch from a first position to a second position;
• detecting the movement of the pressure switch from the first position to the second position;
• actuating the solenoid from a first electrical state to a second electrical state;
• adjusting the displacement of the pump from a first displacement to a second displacement;
• detecting a fluid temperature with a temperature sensor;
• sending a signal to the controller based on the detected temperature;
• and
• adjusting the rate of fluid flow from the pump outlet until the detected temperature reaches a desired temperature.