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US 9,903,378 B2Granted
Method of operating a pumping system
AssigneeEdwards Limited
InventorSimon Harold Bruce
Life of this patent
Estimating the term…
Abstract
A pumping system for evacuating an enclosure comprises a pumping mechanism (30), a motor (32) for driving the pumping mechanism, and a controller (36) for controlling the motor. The controller sets a maximum value for a rotational frequency of the motor and a maximum value for a current in the motor, and, to optimise the performance of the pumping system, independently adjusts the maximum values during evacuation of the enclosure.
Claims21
A vacuum pumping system comprising:
- a pumping mechanism;
- a motor for driving the pumping mechanism;
- and
- a controller for controlling the motor, wherein the controller sets a maximum value for a rotational frequency of the motor and a maximum value for a current in the motor, wherein the controller adjusts the maximum values during operation of the vacuum pumping system, and
- wherein the controller is configured to increase the maximum value for the current in the motor from a normal continuous operation current rating of the motor to be temporarily higher than the normal continuous operation current rating of the motor during operation of the vacuum pumping system at a relatively high pressure,
- wherein the controller is configured to decrease the maximum value for the current in the motor to be no greater than the normal continuous operation current rating of the motor below the relatively high pressure, and
- wherein the controller is configured to increase the maximum value for the rotational frequency of the motor during operation of the vacuum pumping system at a relatively low pressure.
4 more elements
A method of controlling a vacuum pumping system comprising a pumping mechanism and a motor for driving the pumping mechanism, the method comprising:
- setting a maximum value for a rotational frequency of the motor and a maximum value for a current in the motor;
- during operation of the vacuum pumping system at a relatively high pressure, increasing the maximum value for the current in the motor to be higher than a continuous operation current rating of the motor;
- during operation of the vacuum pumping system below the relatively high pressure, decreasing the maximum value for the current in the motor to be no greater than the continuous operation current rating of the motor;
- and
- during operation of the vacuum pumping system at a relatively low pressure, increasing the maximum value for the rotational frequency of the motor.
2 more elements
Dependencies are inferred from the claim text.