Hydromechanical transmission and control method
AssigneeDana Italia S.R.L.
InventorsLorenzo Dalla Palma, Fabio Gunsch, Mario Gelmini, Giovanni Profumo
Life of this patent
Estimating the term…
Abstract
Methods and systems for a hydromechanical transmission are provided herein. In one example, the transmission operating method includes asynchronously shifting between a first pair of drive ranges in the transmission via operation of two clutches and a variable displacement hydraulic pump in a hydrostatic assembly. In the method, asynchronously shifting between the two drive ranges includes a plurality of phases that include a swiveling phase where a speed of the hydrostatic assembly is inverted.
Claims18
A method for operating a transmission system, comprising:
- asynchronously shifting between a first pair of drive ranges in the transmission system via operation of two clutches and a variable displacement hydraulic pump in a hydrostatic assembly;
- wherein asynchronously shifting between the first pair of drive ranges includes a plurality of phases that include a swiveling phase where a speed of the hydrostatic assembly is inverted;
- and
- wherein in the swiveling phase the hydrostatic assembly is speed controlled such that the variable displacement hydraulic pump is controlled based on a speed set-point of a hydraulic motor in the hydrostatic assembly.
A transmission system, comprising:
- a hydrostatic assembly including a hydraulic pump and a hydraulic motor;
- a planetary gearset coupled to a gearbox, the hydrostatic assembly, and an output shaft via separate gears and/or shafts;
- a controller including instructions that when executed during, a shifting event, cause the controller to:
- asynchronously shift between a first pair of drive ranges via operation of two clutches in the gearbox and the hydrostatic assembly;
- wherein asynchronously shifting between the first pair of drive ranges includes a swiveling phase where the hydrostatic assembly is controlled to follow a motor speed set-point and invert a speed of the hydrostatic assembly.
A method for operating a hydromechanical variable transmission, comprising:
- asynchronously shifting between a first pair of forward drive ranges in the hydromechanical variable transmission via operation of two clutches and a hydrostatic assembly while maintaining a uni-directional power flow through the hydromechanical variable transmission;
- wherein asynchronously shifting between the first pair of forward drive ranges includes inverting a speed of the hydrostatic assembly via controlling the hydrostatic assembly based on a motor speed set-point.
Dependencies are inferred from the claim text.