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

Patent metadata

Field	Value
Publication number	US-11209008-B2
Application number	US-201816229778-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Dec 28, 2017
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A pump apparatus which can more accurately determine the occurrence of an abnormal vibration. The pump apparatus includes: 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 the pump. The controller includes a storage unit for storing a measured vibration value measured by the vibration detector. The storage unit has a storage table which, when the rotational speed of the pump is increased stepwise to a predetermined rotational speed, stores the measured vibration value measured at each step.

First claim

What is claimed is:

1. 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 levels of the measured vibration values is not more than the threshold values is termed a first state, and a state in which the at least one vibration levels of the measured vibration values is more than the threshold values 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, wherein it is determined that an abnormality has occurred in the drive shaft when the inverter-side vibration sensor is in the first state, the first motor-side vibration sensor is in the second state, and the second motor-side vibration sensor is in the second state and, in addition, a first abnormal vibration detected by the first motor-side vibration sensor and a second abnormal vibration detected by the second motor-side vibration sensor belong to a same frequency range.

2. The motor assembly according to claim 1 , wherein the controller determines that an abnormality has occurred in the first bearing when the inverter-side vibration sensor is in the first state, the first motor-side vibration sensor is in the second state, and the second motor-side vibration sensor is in the first state; and the controller determines that an abnormality has occurred in the second bearing when the inverter-side vibration sensor is in the first state, the first motor-side vibration sensor is in the first state, and the second motor-side vibration sensor is in the second state.

3. The motor assembly according to claim 1 , wherein the controller determines that an abnormality has occurred in an inverter section including the inverter when the inverter-side vibration sensor is in the second state, the first motor-side vibration sensor is in the first state, and the second motor-side vibration sensor is in the first state.

4. The motor assembly according to claim 1 , wherein the controller determines that an abnormality has occurred in a chassis of the motor assembly when the inverter-side vibration sensor is in the second state, the first motor-side vibration sensor is in the second state, and the second motor-side vibration sensor is in the second state.

5. The motor assembly according to claim 1 , wherein the storage unit has a storage table which, when a rotational speed of the pump is increased stepwise to a predetermined rotational speed, stores a measured vibration value measured at each step, wherein the controller increases the rotational speed of the pump stepwise to the predetermined rotational speed in a test operation, and stores, as a measured test vibration value, the measured vibration value measured at each step in the storage table, and wherein the controller determines the at least one predetermined threshold value by adding or multiplying a numerical value, which indicates a certain percentage or ratio, to or by the measured test vibration value, or by calculating one of an average value, a maximum value and a minimum value of the measured test vibration values as a representative value, and adding or multiplying a predetermined value to or by the representative value, or by calculating a correction amount which is a difference between the measured test vibration value and a predetermined reference vibration value, and determining the at least one predetermined threshold value based on the calculated correction value.

6. 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 measured vibration values of the at least one vibration detector,
wherein the vibration-reducing operation comprises a first vibration-reducing operation which comprises:
changing the rotational speed of the motor to a predetermined first rotational speed and operating the motor at the predetermined first rotational speed for a predetermined first period of time, and then returning the rotational speed of the motor to an original rotational speed and operating the motor at the original rotational speed for a predetermined second period of time.

7. The pump apparatus according to claim 6 , wherein the controller comprises a storage unit for storing the measured vibration values measured by the at least one vibration detector, the storage unit having a storage table which, when a rotational speed of the pump is increased stepwise to a predetermined rotational speed, stores a measured vibration value measured at each step.

8. The pump apparatus according to claim 7 , wherein the controller comprises a test operation mode for increasing the rotational speed of the pump stepwise to the predetermined rotational speed, and storing the measured vibration values measured at each step.

9. The pump apparatus according to claim 8 , wherein in the test operation mode, the controller increases the rotational speed of the pump stepwise to the predetermined rotational speed while keeping a discharge side of the pump shut off.

10. The pump apparatus according to claim 7 , wherein an abnormal vibration of the pump is detected based on the measured vibration values stored in the storage table.

11. The pump apparatus according to claim 7 , wherein the storage unit has an abnormal vibration region for storing the condition of the pump apparatus at a time of a particular rotational speed of the pump at which excessive vibration has occurred, and wherein the controller controls the pump to avoid a condition of the pump apparatus, stored in the abnormal vibration region.

12. The pump apparatus according to claim 7 , wherein the storage unit further stores a predetermined reference vibration value, and a threshold value which serves as a benchmark for an abnormal vibration of the pump, and wherein the controller calculates a correction amount which is a difference between the measured vibration value and a reference vibration value, stored in the storage table, and corrects the threshold value based on the correction amount.

13. The pump apparatus according to claim 7

Assignees

• Ebara Corp

Inventors

• Nishimura Kazuma

Classifications

• F05D2270/334

  Vibration measurements · CPC title

• F04D15/0088 Primary

  Testing machines · CPC title

• F04D15/0077

  Safety measures (F04D15/02 takes precedence) · CPC title

• G01H1/003

  of rotating machines (G01H1/10 takes precedence) · CPC title

• F04C14/24

  characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C14/10 takes precedence) · CPC title