Valve assemblies to supply fluid pressure to components in multiple transmission operating modes
AssigneeAllison Transmission, Inc.
InventorKenneth M. Andrews
Life of this patent
Estimating the term…
Abstract
Transmissions, filter assemblies for transmissions, and valve assemblies for transmissions are disclosed herein. A transmission includes an input shaft, an output shaft, and a hydraulic system. The input shaft is configured to receive rotational power supplied by a drive unit. The output shaft is coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load. The hydraulic system is configured to supply fluid to one or more fluid demand devices coupled between the input shaft and the output shaft in one or more operating modes of the transmission. The hydraulic system includes a filter assembly having a filter element and a valve assembly fluidly coupled to the filter element.
Claims20
A transmission for a vehicle, the transmission comprising:
- an input shaft configured to receive rotational power supplied by a drive unit;
- an output shaft coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load;
- and
- a hydraulic system configured to supply fluid to one or more fluid demand devices coupled between the input shaft and the output shaft in one or more operating modes of the transmission, wherein the hydraulic system includes a filter assembly having a filter element and a valve assembly fluidly coupled to the filter element, wherein the valve assembly includes
- a housing having an interior chamber;
- and
- a spool movable in the interior chamber between a de-stroked position, in which the spool permits fluid flow through the valve assembly to the one or more fluid demand devices substantially without application of fluid pressure to the spool by fluid passed through the filter element, and a stroked position, in which the spool permits fluid flow through the valve assembly to the one or more fluid demand devices in response to fluid pressure applied to the spool by fluid passed through the filter element,
- wherein the spool is formed to include a plurality of spiraled slots shaped to conduct fluid therethrough when the spool is in the stroked position to improve fluid flow to the one or more fluid demand devices through the valve assembly.
A filter assembly for use in a hydraulic system of a transmission, the filter assembly comprising:
- a filter element;
- and
- a valve assembly in fluid communication with the filter element, the valve assembly including
- a housing having an interior chamber;
- and
- a spool formed to include a plurality of spiraled slots that is movable in the interior chamber between a de-stroked position, in which the spool permits fluid flow through the valve assembly to one or more fluid demand devices substantially without application of fluid pressure to the spool by fluid passed through the filter element, and a stroked position, in which the spool permits fluid flow through the spiraled slots to the one or more fluid demand devices in response to fluid pressure applied to the spool by fluid passed through the filter element,
- wherein when the spool is in the de-stroked position, the spool blocks fluid backflow through the valve assembly to the filter element.
A valve assembly for use in a hydraulic system of a transmission, the valve assembly comprising:
- a housing having an interior chamber;
- a spool positioned in the interior chamber that is formed to include a plurality of spiraled slots;
- and
- a biasing element arranged in contact with the spool to apply a biasing force to the spool,
- wherein the spool is movable in the interior chamber between a de-stroked position, in which the spool permits fluid flow through the valve assembly to one or more fluid demand devices substantially without application of fluid pressure to the spool, and a stroked position, in which the spool permits fluid flow through the spiraled slots to the one or more fluid demand devices in response to fluid pressure applied to the spool, and wherein the biasing force urges the spool toward the de-stroked position.
Dependencies are inferred from the claim text.