Back to results
US 9,759,318 B2Granted
Multi-plexing clutch logic control of a multi-mode transmission
AssigneeAllison Transmission, Inc.
InventorsCharles F. Long, Darren J. Weber, John William Edward Fuller, Stephen Murray
Life of this patent
Estimating the term…
Abstract
A transmission includes an electro-hydraulic controller that includes redundancy in the hydraulic circuit that permits single fault failures to be compensated for by changing the flow path of hydraulic fluid to bypass the single fault failure. The redundancy results in the ability of the transmission to maintain full operation in all modes.
Claims17
A method of operating a transmission, the method comprising:
- supplying hydraulic fluid from a fluid source to a hydraulic circuit of the transmission at a fluid pressure,
- varying the flow path of hydraulic fluid to a plurality of clutches of the transmission by a mode logic section that includes a first logic valve assembly and a second logic assembly operable in combination with one another to selectively apply a first trim pressure different from the fluid pressure to an input clutch of the plurality of clutches that is selectively engageable to transmit rotation to a variator from an input shaft of the transmission and a second trim pressure different from the fluid pressure to another of the plurality of clutches, and
- varying the pressures applied to the plurality of clutches by a mode trim section so that the mode trim section and the mode logic section cooperate to vary the pressure applied to each of the plurality of clutches to vary the operating mode of the transmission such that the transmission is operable in (i) a first mode in which none of the plurality of clutches is active, (ii) a second mode in which the first trim pressure is applied to the input clutch and none of the other of the plurality of clutches is active, (iii) a third mode in which a main pressure is applied to the input clutch and none of the other of the plurality of clutches is active, (iv) a fourth mode in which the main pressure is applied to the input clutch, the first trim pressure is applied to a first mode clutch of the plurality of clutches, and none of the other of the plurality of clutches is active, (v) a fifth mode in which the main pressure is applied to the input clutch, the first trim pressure is applied to the first mode clutch, the second trim pressure is applied to a second mode clutch of the plurality of clutches, and none of the other of the plurality of clutches is active, (vi) a sixth mode in which the main pressure is applied to the input clutch, the second trim pressure is applied to the second mode clutch, the first trim pressure is applied to a third mode clutch of the plurality of clutches, and the first mode clutch is not active, and (vii) a seventh mode in which the main pressure is applied to the input clutch, the first trim pressure is applied to the third mode clutch, and the first and second mode clutches are not active.
A method of operating a transmission, the method comprising:
- supplying hydraulic fluid from a fluid source to a hydraulic circuit of the transmission at a main pressure,
- varying the flow path of hydraulic fluid to a plurality of clutches of the transmission by a mode logic section that includes a first logic valve assembly and a second logic assembly operable in combination with one another to selectively (i) apply the main pressure to a first clutch of the plurality of clutches, a first trim pressure, different from the main pressure, to a second clutch of the plurality of clutches, and a second trim pressure, different from the main pressure, to a third clutch of the plurality of clutches, and (ii) vent the second clutch such that no pressure is applied to the second clutch while continuing to apply the second trim pressure to the third clutch, and
- varying the pressures applied to the plurality of clutches by a mode trim section so that the mode trim section and the mode logic section cooperate to vary the pressure applied to each of the plurality of clutches to vary the operating mode of the transmission such that the transmission is operable (i) a first mode in which the first trim pressure is applied to the first clutch and the second and third clutches are not active, (ii) a second mode in which the first trim pressure is applied to the first clutch, the second trim pressure is applied to the second clutch, and the third clutch is not active, (iii) a third mode in which the main pressure is applied to the first clutch, the first trim pressure is applied to the second clutch, and the second trim pressure is applied to the third clutch, and (iv) a fourth mode in which the main pressure is applied to the first clutch, the second trim pressure is applied to the third clutch, and the second clutch is not active,
- wherein one of the first clutch, the second clutch, and the third clutch is selectively engageable to transmit rotation to a variator from an input shaft of the transmission.
1 more element
A method of operating a transmission, the method comprising:
- supplying hydraulic fluid from a fluid source to a hydraulic circuit of the transmission at a main pressure, and
- operating a mode logic section configured to control the flow path of hydraulic fluid to a plurality of clutches of the transmission in combination with a mode trim section configured to control the pressure applied to the plurality of clutches in each of (i) a first mode in which a first trim pressure, different from the main pressure, is applied to a first clutch of the plurality of clutches while venting a second and third clutch of the plurality of clutches such that the second and third clutches are not activated, (ii) a second mode in which the first trim pressure is applied to the first clutch and a second trim pressure, different from the main pressure, is applied to the second clutch while venting the third clutch such that the third clutch is not activated, (iii) a third mode in which the main pressure is applied to the first clutch, the first trim pressure is applied to the second clutch, and the second trim pressure is applied to the third clutch, and (iv) a fourth mode in which the main pressure is applied to the first clutch and the second trim pressure is applied to the third clutch while venting the second clutch such that the second clutch is not activated,
- wherein one of the first clutch, the second clutch, and the third clutch is selectively engageable to transmit rotation to a variator from an input shaft of the transmission.
Dependencies are inferred from the claim text.