Hydro-mechanical park-by-wire shift systems, transmissions incorporating the same, and methods for transmissions
AssigneeAllison Transmission, Inc.
InventorsIonut Manta, Nicholas Walke
Life of this patent
Estimating the term…
Abstract
Transmissions, park systems for transmissions, and methods for transmissions are envisioned. A transmission includes an input shaft to receive torque from a drive unit, an output shaft to transmit torque to a load, and a park system to selectively brake the output shaft. The park system includes a park assembly, an electro-hydraulic valve assembly to deliver one or more fluid pressures, and an actuation linkage having a piston axially translatable along a longitudinal axis in response to the one or more fluid pressures delivered thereto from the electro-hydraulic valve assembly.
Claims16
A transmission comprising:
- an input shaft to receive torque from a drive unit;
- an output shaft to transmit torque to a load;
- and
- a park system to selectively brake the output shaft, the park system comprising
- an electro-hydraulic valve assembly to deliver one or more fluid pressures, and
- an actuation linkage including a piston axially translatable along a longitudinal axis in response to the one or more fluid pressures delivered thereto from the electro-hydraulic valve assembly, a plate pivotally coupled to the piston such that movement of the piston along the longitudinal axis causes rotation of the plate about a rotational axis, and a biasing element extending through the plate that surrounds the rotational axis and applies a biasing force to the plate to urge interaction between the plate and the piston,
- wherein:
- the plate is formed to include at least one mount aperture that extends through the plate in a radial direction relative to the rotational axis;
- and
- a mount tang of the biasing element extends through the at least one mount aperture in the radial direction such that the biasing element is at least partially retained in place by the plate.
A park system to selectively brake an output shaft of a transmission, the park system comprising:
- an electro-hydraulic valve assembly to deliver one or more fluid pressures, and
- an actuation linkage including a piston axially translatable along a longitudinal axis in response to the one or more fluid pressures delivered thereto from the electro-hydraulic valve assembly, a plate pivotally coupled to the piston such that movement of the piston along the longitudinal axis causes rotation of the plate about a rotational axis, and a bushing arranged between the plate and an interior surface of a case of the transmission that supports the plate for rotation about the rotational axis, the bushing formed to include a pair of slots extending therethrough that are circumferentially spaced 180 degrees from one another about the rotational axis.
A park system to selectively brake an output shaft of a transmission, the park system comprising:
- an electro-hydraulic valve assembly to deliver one or more fluid pressures,
- an actuation linkage having a piston axially translatable along a longitudinal axis in response to the one or more fluid pressures delivered thereto from the electro-hydraulic valve assembly,
- a magnet assembly affixed to the piston for axial translation therewith that includes at least one magnet and a housing having a mount plate, and
- a position sensor to detect a position of the at least one magnet that is spaced from the longitudinal axis,
- wherein:
- the piston includes a head having a first diameter and a projection that extends outwardly from the head and has a second diameter less than the first diameter;
- the projection defines a planar mounting surface;
- and
- the mount plate is arranged in direct contact with the planar mounting surface.
Dependencies are inferred from the claim text.