Machine and method for monitoring the state of a safety bearing of a machine
View Patent ↗An operating method for container quay cranes used to load and unload container ships aided by a PC with a monitor in a crane driver's cabin. The crane driver operates a touchscreen on the monitor, thereby enabling the crane to reach its specified target in a fully or partially automatic manner. Several operating modes, including a training mode, are provided.
1. A method for monitoring wear of a safety bearing of a rotor shaft of a machine, wherein the rotor shaft is supported by a magnetic bearing, the safety bearing having an outer ring and an inner ring arranged for rotation with respect to the outer ring, the method comprising the steps of in the following order:
switching the magnetic bearing off for monitoring the state of the safety bearing,
catching a rotor shaft of the machine with the safety bearing when the magnetic bearing is switched off, and
while the magnetic bearing remains switched off
rotating the rotor shaft with the machine by using a defined motion sequence,
measuring a physical variable of the safety bearing with a sensor, wherein the physical variable is a distance between the outer ring and the inner ring, and
determining the wear of the safety bearing from the measured distance between the outer ring and the inner ring.
2. The method of claim 1 , further comprising the steps of:
comparing the measured physical variable or a variable derived from the measured physical variable with a target variable, and
generating a warning message, if a deviation of the physical variable or the derived variable exceeds a threshold value.
3. The method of claim 1 , wherein the safety bearing is attached in the machine with a safety bearing carrier arranged around the outer ring, and wherein the sensor is arranged on a side of the outer ring facing the safety bearing carrier.
4. The method of claim 1 , wherein the physical variable further comprises a variable selected from the group consisting of a temperature of the safety bearing, a force between the outer ring and the safety bearing carrier, oscillations of the safety bearing, and a pressure between outer ring and the safety bearing carrier.
5. The method of claim 1 , wherein the sensor is arranged between the outer ring and the safety bearing carrier.
6. The method of claim 1 , wherein the sensor has a flat configuration and is embedded in or arranged on a film.
7. The method of claim 3 , wherein at least a part of the sensor is arranged in a recess disposed on the side of the outer ring facing the safety bearing carrier.
8. The method of claim 1 , wherein at least part of the sensor is arranged inside the inner ring.
9. The method of claim 1 , wherein roller bearings are arranged between the outer ring and inner ring, or wherein the inner ring slides directly in the outer ring.
10. The method of claim 1 , wherein the physical variable is transmitted via a data link to a computer arranged remote from the machine.
11. The method of claim 1 , wherein the machine is embodied as an electric motor, a generator, a compressor, or a turbine.