Fluid machine

Patent metadata

Field	Value
Publication number	US-11976648-B2
Application number	US-201917269101-A
Country	US
Kind code	B2
Filing date	Nov 28, 2019
Priority date	Dec 20, 2018
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

Even when abnormal heat generation occurs during operation in a state where the temperature of a compressor is not increased, abnormality cannot be detected. A fluid machine includes a fluid machine body; a motor that drives the fluid machine body; a temperature sensor that measures a temperature of the fluid machine body; and a control unit that controls the fluid machine body. The control unit changes a temperature threshold value based on at least one of a pressure of a fluid discharged by the fluid machine body and a frequency of a voltage input into the motor, and issues a notification when the temperature of the compressor body measured by the temperature sensor exceeds the temperature threshold value.

First claim

The invention claimed is:

1. A compressor comprising:
a compressor body having a motor and a compression mechanism driven by the motor;
a cooling fan that is disposed on the non-load side of the motor, and that cools the compression mechanism;
a temperature sensor that measures a temperature of the compressor body; and
a control unit that controls the compressor body, wherein the control unit
issues a notification when the temperature measured by the temperature sensor exceeds a temperature threshold value, and
changes the temperature threshold value of the temperature sensor to a second threshold value that is lower than the first threshold value in a region where the rotation speed of the cooling fan is high,
increases the temperature threshold value when the pressure of the compressed gas discharged from the compressor body increases, and
immediately increases the temperature threshold value when increasing the temperature threshold value, and decreases the temperature threshold value in a stepwise manner when decreasing the temperature threshold value.

2. The compressor according to claim 1 , wherein when the frequency for driving the compressor body is equal to or higher than a predetermined value, the control unit determines that the rotation speed is in a region that is higher than another region, and changes the temperature threshold value to the second threshold value.

3. The compressor according to claim 2 , wherein the compression mechanism is mounted on the load side of the motor.

4. The compressor according to claim 2 , wherein the control unit does not issue the notification that the temperature measured by the temperature sensor exceeds the temperature threshold value for a predetermined time after the compressor body restarts operation.

5. The compressor according to claim 2 , wherein the temperature sensor is attached to a cooling fin of the compression mechanism.

6. The compressor according to claim 1 , wherein the compression mechanism is mounted on the load side of the motor.

7. The compressor according to claim 1 , wherein the control unit does not issue the notification that the temperature measured by the temperature sensor exceeds the temperature threshold value for a predetermined time after the compressor body restarts operation.

8. The compressor according to claim 1 , wherein the temperature sensor is attached to a cooling fin of the compression mechanism.

9. The compressor according to claim 1 , wherein a number of revolutions of the cooling fan and a number of revolutions of the motor are the same.

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Yamamoto Akihiro
• Kanemoto Yoshiyuki
• Oka Daichi

Classifications

• F04B49/103 Primary

  Responsive to speed · CPC title

• F04B49/08 Primary

  Regulating by delivery pressure · CPC title

• F04C14/28

  Safety arrangements; Monitoring · CPC title

• F04C28/28

  Safety arrangements; Monitoring · CPC title

• F04B2201/0801

  Temperature · CPC title