Variator switching valve scheme for a torroidal traction drive transmission

摘要

An apparatus for controlling a variator having at least one roller between two torroidal disks may include at least one actuator responsive to fluid pressure at separate high side and low side fluid inlets thereof to control torque applied by the at least one roller to the disks. First and second variator switching valves may each receive a first fluid at a first pressure and a second fluid at a second lesser pressure. The first and second variator switching valves supply the first fluid to the high side fluid inlet and the second fluid to the low side fluid inlet during two of four different operational states together defined by the variator switching valves, and supply the second fluid to the high side fluid inlet and the first fluid to the low side fluid inlet during each of the remaining two of the four different operational states.

主权项

1. An apparatus for controlling a variator, the apparatus comprising:
at least one actuator responsive to fluid pressure at separate high side and low side fluid inlets thereof to control torque applied to an input and an output of the variator, and first and second variator switching valves each configured to receive a first fluid at a first pressure and a second fluid at a fixed pressure less than the first pressure, the first and second variator switching valves selective to supply (i) one of the first fluid and the second fluid to the high side fluid inlet of the at least one actuator and (ii) the other of the first fluid and the second fluid to the low side fluid inlet of the at least one actuator.