Lift off speed detection
AssigneeGarrett Transportation I Inc.
InventorsRadu Florea, Frederic Daguin
Life of this patent
Estimating the term…
Abstract
A compressor having a rotational shaft supported by a plurality of air foil bearings, a frequency sensor for detecting a frequency of a signal emitted by the device during rotation of the rotational shaft, a controller for detecting a lift off speed of the plurality of air foil bearings in response to the frequency of the signal, and a memory for storing the lift off speed, wherein the memory is communicatively coupled to a device controller for controlling a rotational speed of the rotational shaft in response to the lift off speed wherein the detection of the lift off speed is made in response to a sudden change in the frequency of the signal emitted by the device during a coast down of the compressor from a maximum rotational speed to a zero rotational speed.
Claims20
An apparatus comprising:
- a device having a rotational shaft supported by a plurality of air foil bearings;
- a sensor for detecting a magnitude and a frequency of a signal emitted by the device during rotation of the rotational shaft;
- a controller for detecting a lift off speed of the plurality of air foil bearings in response to the frequency of the signal;
- and
- a memory for storing the lift off speed, wherein the memory is communicatively coupled to a device controller for controlling a rotational speed of the rotational shaft in response to the lift off speed.
A method for determining a lift off speed of an air foil bearing comprising:
- controlling a device having a rotational shaft supported by a plurality of air foil bearings to rotate at a predetermined operational rotational speed;
- disengaging a drive source coupled to the rotational shaft such that the rotational shaft such that the begins a rotational speed coast down phase from the maximum operational rotational speed to a zero rotational speed;
- detecting, by a sensor, at least one of a frequency and a magnitude of a vibration of the device and a rotational speed of the rotational shaft at a plurality of times within the coast down phase;
- determining, by a test controller, a lift off speed of the air foil bearing in response to the plurality of frequencies;
- and
- storing the lift off speed in a memory communicatively coupled to the device.
A compressor test system comprising:
- a rotational sensor for measuring a rotational speed of a compressor shaft supported by an air foil bearing;
- a sensor for measuring at least one of a frequency and a magnitude of a vibration generated in response to a rotation of the compressor shaft;
- a controller for determining a lift off speed of the air foil bearing in response to the frequency of the vibration and the rotational speed measured at a plurality of times during a transition of the rotational speed between a first rotational speed and a second rotational speed;
- and
- a compressor controller for controlling an operation of the compressor such that an operating rotational speed of the compressor shaft is greater than the lift off speed.
Dependencies are inferred from the claim text.