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US 2015/0027259 A1Published application
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.
Claims20
An electro-hydraulic control for a multi-speed vehicle transmission, comprising:
- a plurality of actuators each configured to output fluid pressure in response to electrical shift request signals;
- a plurality of shift valves in fluid communication with the actuators and with each other to selectively deliver fluid pressure to a plurality of shift mechanisms of the transmission, the plurality of shift valves comprising:
- a single-diameter shift valve;
- a two-diameter shift valve;
- and
- a three-diameter shift valve.
3 more elements
An electro-hydraulic control for a multi-speed vehicle transmission, comprising:
- a plurality of actuators each configured to output fluid pressure in response to electrical shift request signals;
- and
- a plurality of shift valves in fluid communication with the actuators and with each other to selectively deliver fluid pressure to a plurality of shift mechanisms of the transmission, the plurality of shift valves comprising a multiple-diameter shift valve, the multiple diameter shift valve having a first position when the transmission is not in a forward range, a second position when the transmission is in a forward range, and a latching feature that maintains the second position if an electrical failure occurs while the transmission is in a forward range.
Dependencies are inferred from the claim text.