Hydraulic control system for a synchronizer
AssigneeNew Holland North America, Inc.
InventorMichael Richardson
Life of this patent
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Abstract
A hydraulic control system for displacing a synchronizer into engagement with a rotating gear in a gearbox includes a hydraulic piston/cylinder unit mechanically coupled to the synchronizer, an electrically controllable pressure regulating valve for supplying hydraulic fluid to the piston/cylinder unit and an electrical control circuit acting on the pressure regulating valve to vary the pressure of the hydraulic fluid supplied to the piston/cylinder unit. In order to effect a rapid and smooth engagement of the synchronizer, the control circuit acts to increase the pressure of the hydraulic fluid supplied to the piston/cylinder unit progressively.
Claims4
A hydraulic control system for displacing a synchronizer into engagement with a rotating gear in a gearbox, comprising:
- a hydraulic piston/cylinder unit mechanically coupled to the synchronizer;
- an electrically controllable pressure regulating valve for supplying hydraulic fluid to the piston/cylinder unit;
- an electrical control circuit cooperatively associated with the pressure regulating valve to vary the pressure of the hydraulic fluid supplied to the piston/cylinder unit, wherein during each engagement movement of the synchronizer, the control circuit is operative to increase the pressure of the hydraulic fluid supplied to the piston/cylinder unit progressively;
- and
- means for sensing the change in pressure in the piston/cylinder unit resulting from the movement of the synchronizer to determine when axial engagement between the synchronizer and the gear has been achieved, and for rapidly increasing the hydraulic pressure thereafter to its maximum value to ensure full engagement of the synchronizer.
Dependencies are inferred from the claim text.