Method for operating a hydrostatic actuator system
AssigneeSchaeffler Technologies AG & Co. KG
InventorErhard Hodrus
Life of this patent
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Abstract
A hydrostatic actuator system includes an electric motor for delivering a hydraulic fluid via a piston unit. The actuator system is operating using a method in which a change in volume caused by a temperature change is sensed by a pressure measurement. The method reliably identifies a state of the transfer of the hydraulic fluid from a planetary roller transmission compartment into the master piston. The pressure measurement is continuously evaluated, and, in the event of a negative signal of the pressure measurement, suction of the hydraulic fluid by a planetary roller transmission lying in the hydraulic fluid between the electric motor and the piston unit into the piston unit is recognized and a fault signal is output.
Claims15
A method for operating a hydrostatic actuator system, in which an electric motor is used for delivering a hydraulic fluid in the actuator having a piston unit, in which a change in volume of the hydraulic fluid caused by a temperature change is sensed by a pressure measurement, wherein the pressure measurement is continuously evaluated, wherein, in the event of a negative signal of the pressure measurement, suction of the hydraulic fluid by a planetary roller transmission lying in the hydraulic fluid between the electric motor and a spindle into the piston unit is recognized and a fault signal is output, and in which a sniffing action is triggered on the basis of the fault signal to eliminate a shift in a characteristic curve.
An actuator system comprising:
- a spindle;
- a master cylinder;
- a piston within the master cylinder and axially fixed to the spindle;
- an electric motor driving the spindle via a planetary transmission, the planetary transmission being encased in a sleeve;
- a pressure sensor within the sleeve;
- and
- a controller programmed to evaluate a signal from the pressure sensor and output a fault signal in response to a negative pressure.
Dependencies are inferred from the claim text.