Hydraulic piston design
AssigneeAllison Transmission, Inc.
InventorsIonut Manta, Evan Meredith
Life of this patent
Estimating the term…
Abstract
A system has been developed for engaging a clutch pack using a hydraulic piston. The system can be used with an automatic transmission or another part of the drivetrain of a vehicle. The system includes a piston, a clutch pack, and a housing that contains the piston and clutch pack. To engage and disengage the piston against the clutch pack, the system is configured to fill and empty a hydraulic chamber on a hydraulic side of the piston such that the hydraulic fluid moves the piston towards and away from the clutch pack. The piston includes one or more pads or standoffs that form flow gaps. The piston is further configured to position seals on the piston closer to the hydraulic side.
Claims21
A system, comprising:
- a clutch assembly including
- a clutch pack,
- a housing defining a bore,
- a piston being slidably disposed in the bore,
- wherein the piston is configured to actuate the clutch pack,
- wherein the piston has a head,
- wherein the head has one or more pads extending from the head,
- wherein the housing defines a flow passage into the bore,
- wherein the flow passage is configured to both supply hydraulic fluid to the bore and exhaust the hydraulic fluid from the bore,
- wherein the head includes an inner head and an outer head,
- wherein the head defines a channel,
- wherein the channel is defined between the inner head and the outer head,
- wherein the inner head is disposed radially inwards relative to the outer head,
- wherein the piston has an engaged position where the piston engages the clutch pack,
- wherein the piston has a disengaged position where the piston is disengaged from the clutch pack,
- wherein the bore has a bore head wall,
- wherein the bore head wall faces the head of the piston,
- wherein the one or more pads extend from the inner head to form a standoff,
- wherein the one or more pads are absent from the outer head,
- wherein the one or more pads define one or more gaps where the hydraulic fluid flows,
- wherein the one or more pads are configured to contact the bore head wall when in the disengaged position,
- wherein the inner head and the outer head each have a surface facing the bore head wall that are planar with one another, and
- wherein the one or more pads extend from the surface of the inner head farther than the surface of the outer head towards the bore head wall.
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A system, comprising:
- a clutch assembly including
- a housing defining a bore,
- a clutch pack,
- a piston being configured to actuate the clutch pack, wherein the piston has a head,
- wherein the head includes an inner head and an outer head, wherein the piston has an engaged position where the piston engages the clutch pack, wherein the piston has a disengaged position where the piston is disengaged from the clutch pack,
- a spring being configured to bias the piston to the disengaged position,
- wherein the inner head defines an inner groove,
- an inner gasket received in the inner groove,
- wherein the inner gasket is configured to seal against the bore,
- wherein the outer head defines an outer groove,
- an outer gasket received in the outer groove,
- wherein the outer gasket is configured to seal against the bore,
- wherein the head of the piston is configured to recess the inner gasket and the outer gasket further into the bore,
- wherein the inner gasket and the outer gasket axially overlap in a direction that is orthogonal to a rotational axis of the clutch assembly,
- wherein the head has one or more pads extending from the head,
- wherein the head defines a channel,
- wherein the channel is defined between the inner head and the outer head,
- wherein the inner head is disposed radially inwards relative to the outer head,
- wherein the one or more pads extend from the inner head to form a standoff,
- wherein the one or more pads are absent from the outer head,
- wherein the one or more pads define one or more gaps,
- wherein the inner head and the outer head each have a surface that are planar with one another, and
- wherein the one or more pads extend from the surface of the inner head farther than the surface of the outer head.
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Dependencies are inferred from the claim text.