System and method for controlling a journal bearing

A system comprising:

• a journal bearing including a carrier, a rotor arranged rotatable about a rotational axis relative to the carrier, and a fluid in a clearance between the rotor and the carrier;
• a vibration sensor configured to measure a vibration of the rotor and provide a vibration signal corresponding to the vibration;
• a control system adapted to determine a pressure set point for the fluid in the clearance based on the vibration signal, and to provide control signals generated based on the pressure set point;
• and
• an active system including at least one valve configured to modify a pressure of the fluid in the clearance based on the control signals;
• wherein the control system is adapted to determine the pressure set point by selecting a predefined pressure set point from a set of predefined pressure set points based on the vibration signal;
• wherein each predefined pressure set point of the set of predefined pressure set points is a value between a minimum pressure value and a maximum pressure value, wherein the control system is adapted to determine at least one chosen from the minimum pressure value and the maximum pressure value based on a rotational speed of the rotor relative to the carrier.

A method for monitoring a journal bearing, the journal bearing including a carrier, a rotor arranged rotatable about a rotational axis relative to the carrier, and a fluid in a clearance between the rotor and the carrier, the method comprising the steps of:

• determining a rotational speed of the rotor relative to the carrier;
• measuring a vibration signal corresponding to a vibration of the rotor;
• and
• determining whether or not the vibration signal of the rotor comprises a frequency that is synchronous with the rotational speed, or near-synchronous within a predefined range of frequencies adjacent synchronicity with the rotational speed;
• detuning the vibration of the rotor, the detuning comprising:
• providing a control signal when the vibration signal comprises a frequency that is in a predefined range relative to the rotational speed;
• and
• at least one chosen from decreasing a pressure of the fluid in the clearance and increasing a temperature of the fluid in the clearance in response to the provision of the control signal.