Pump apparatus, test operation method of pump apparatus, motor assembly and method for identifying abnormal vibration of motor assembly

A test operation method of a pump apparatus including a pump;

• an electric motor for driving the pump;
• an inverter as a speed changing means for the electric motor;
• a vibration detector for detecting at least one of a vibration of the pump, a vibration of the electric motor and a vibration of the inverter;
• and a controller for controlling a rotational speed of the pump, and including a storage unit for storing a measured vibration value measured by the vibration detector, said method comprising increasing the rotational speed of the pump stepwise to a predetermined rotational speed while performing a shut-off operation of the pump with a valve on the discharge side of the pump fully closed, and storing the measured vibration value measured at each step in a storage table of the storage unit.

A test operation method of a pump apparatus including a pump;

• an electric motor for driving the pump;
• an inverter as a speed changing means for the electric motor;
• a vibration detector for detecting at least one of a vibration of the pump, a vibration of the electric motor and a vibration of the inverter;
• and a controller for controlling a rotational speed of the pump, and including a storage unit for storing a measured vibration value measured by the vibration detector, said method comprising:
• opening a valve on a discharge side of the pump so that the pump is operated at a maximum efficiency point;
• and increasing the rotational speed of the pump stepwise to a predetermined rotational speed, and storing the measured vibration value measured at each step in a storage table of the storage unit.

A motor assembly comprising:

• a motor;
• an inverter as a speed changing means for the motor;
• and
• a controller for controlling the motor, wherein the motor assembly has a first bearing disposed on a counter-load side of the motor and which rotatably supports a drive shaft of the motor, and a second bearing disposed on a load side of the motor and which rotatably supports the drive shaft, and the motor assembly comprises a first motor-side vibration sensor for detecting a vibration of the first bearing, a second motor-side vibration sensor for detecting a vibration of the second bearing, and an inverter-side vibration sensor for detecting a vibration of the inverter, and wherein the controller detects an abnormal vibration based on values detected by the first motor-side vibration sensor, the second motor-side vibration sensor and the inverter-side vibration sensor,
• wherein the controller calculates vibration levels of values, detected by the first motor-side vibration sensor, the second motor-side vibration sensor and the inverter-side vibration sensor, for each of varying frequency ranges, and stores the calculated vibration levels as measured vibration values in a storage unit, wherein the controller has at least one predetermined threshold value to be compared with at least one of the vibration levels, and wherein when a state in which the at least one vibration level(s) of the measured vibration values is not more than the threshold value(s) is termed a first state, and a state in which the at least one vibration level(s) of the measured vibration values is more than the threshold value(s) is termed a second state, the controller detects the abnormal vibration when at least one of the vibration levels is in the second state, and identifies a cause of the abnormal vibration based on the measured vibration values.

A motor assembly comprising:

• a motor;
• an inverter as a speed changing means for the motor;
• and
• a controller for controlling the motor, wherein the motor assembly comprises at least one vibration detector for detecting a vibration of the motor assembly, and wherein the controller performs a vibration-reducing operation, which involves a change of a rotational speed of the motor, based on values of the at least one vibration detector.