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.
Claims19
A transmission system operating method, 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 the asynchronously shifting includes multiple phases that are sequentially implemented;
- wherein the hydrostatic assembly is torque controlled during a preparation phase and an incoming clutch engagement phase;
- and
- wherein the hydrostatic assembly is speed controlled in at least a portion of one of the multiple phases that occurs after the preparation phase and prior to the incoming clutch engagement phase.
A transmission system, comprising:
- a hydrostatic assembly including a hydraulic pump and a hydraulic motor;
- a planetary gear set coupled to a gearbox, the hydrostatic assembly, and an output shaft via separate gears and/or shafts;
- and
- wherein the gearbox includes an incoming clutch and an outgoing clutch;
- a controller including instructions that when executed, during a shifting event where a hand-off occurs between the incoming clutch and the outgoing clutch, cause the controller to:
- asynchronously shift between two drive ranges via operation of two clutches in the gearbox and the hydrostatic assembly;
- wherein the asynchronously shift includes multiple phases that are sequentially implemented;
- wherein the hydrostatic assembly is torque controlled during a preparation phase and an incoming clutch engagement phase;
- and
- wherein the hydrostatic assembly is speed controlled in at least a portion of one of the multiple phases that occurs after the preparation phase and prior to the incoming clutch engagement phase.
Dependencies are inferred from the claim text.