Back to results
US 9,765,877 B2Granted
Electronically controlled range valve for multi-speed planetary transmission
AssigneeAllison Transmission, Inc.
InventorsCharles F. Long, Charles T. Taylor
Life of this patent
Estimating the term…
Abstract
A shift by wire control for a multi-speed vehicle transmission is provided. The control includes a shift by wire shift valve in fluid communication with other shift valves and clutch trim valves to provide double blocking features in the neutral range and a reverse range. The shift by wire valve is configured with multiple differential areas to provide failure modes for all forward ranges.
Claims18
A method of operating a transmission, the method comprising
- receiving one or more electrical shift request signals by an electrical control of the transmission to shift the transmission to any one of a plurality of forward ranges from a non-forward range, and
- shifting the transmission from the non-forward range to the any one of the plurality of forward ranges in response to receiving the one or more electrical shift request signals by actuating at least a first actuator in fluid communication with a three-diameter shift valve to cause the three-diameter shift valve to change position, wherein the three-diameter shift valve includes a first land, a second land, and a third land, and wherein each of the first, second, and third lands has a diameter different from each other.
A method of operating a transmission, the method comprising
- receiving one or more electrical shift requests signals by an electrical control of the transmission to shift the transmission to any one of a plurality of forward ranges from a non-forward range,
- shifting the transmission from the non-forward range to the any one of the plurality of forward ranges in response to receiving the one or more electrical shift request signals by actuating at least a first actuator in fluid communication with a three-diameter shift valve to cause the three-diameter shift valve to change position, and
- maintaining the position of the three-diameter shift valve by one or more latching features after shifting the transmission from the non-forward range to the any one of the plurality of forward ranges in an event of an electrical failure.
Dependencies are inferred from the claim text.