Apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment

• US 5,285,457 A
• Filed: 12/18/1992
• Issued: 02/08/1994
• Est. Priority Date: 04/26/1991
• Status: Expired due to Term

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Nakahara, Kenji, Funakubo, Tsutomu
• Primary Examiner(s): Epps, Georgia Y.
• Application Number:
  US07/965,402
• Time in Patent Office: 417 Days
• Field of Search: 372/38, 372/58, 372/59, 372/34
• US Class Current: 340/635
• CPC Class Codes: F04D 27/001 Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
• CPC Class Codes: F04D 27/0292 Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves
• CPC Class Codes: F04D 29/059 Roller bearings
• CPC Class Codes: F16C 19/527 related to vibration and noise
• CPC Class Codes: H01S 3/036 Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube H01S3/031 takes precedence

Abstract

The present invention relates to an apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment, and the purpose of the invention is to immediately find abnormal bearing conditions of the blower as a result of lubrication failures. The apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment is characterized in that it comprises a vibration sensor(2 ) that detects vibration of the bearing mounted at the blower(1) and outputs a vibration detected signal FIS; an amplifier(3) that amplifies the vibration detected signal FIS received from the vibration sensor(2); a comparator(4) that discriminates whether an amplified vibration detected signal FOS exceeds a determined value or not, and outputs an abnormal signal PS when it exceeds the determined value; an alarm command means(5) that outputs an alarm command signal AS when the number of the abnormal signal PS output from the comparator(4) during a determined interval exceeds a determined number; and an alarm display means(6) that displays an alarm when the alarm command signal AS is sent from the alarm command means(5 ).

Claims

1. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment is characterized in that it comprises,

a vibration sensor(2) that detects the vibration of said bearing mounted at said blower(1) and outputs a vibration detected signal FIS;

an amplifier(3) amplifies said vibration detected signal FIS received from said vibration sensor(2);

a comparator(4) discriminates whether an amplified vibration detected signal FOS exceeds a determined value or not, and outputs an abnormal signal PS when it exceeds said determined value;

an alarm command means(5) outputs an alarm command signal AS when the number of said abnormal signals PS output from said comparator(4) during a determined interval exceeds a determined number; and

an alarm display means(6) displays an alarm when said alarm command signal AS is sent from said alarm command means(5).

2. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 1, wherein said vibration sensor(2) is an acceleration type vibration sensor that detects acceleration elements of vibration.

3. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 1, wherein said vibration detected signal FIS is a peak value of said vibration of said bearing.

4. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 1, wherein said vibration sensor(2) detects vibration with a particular frequency.

5. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 1, wherein a fast Fourier transformer is provided between said amplifier(3) and said comparator(4), and outputs vibration with said particular frequency.

6. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 4 or 5, wherein said particular frequency is 6 times as much as the rotation frequency of said blower(1).

7. An apparatus for detecting an abnormal bearing condition of a blower utilized for gas laser equipment claimed in claim 1, wherein a band pass filter is provided between said amplifier(3) and said comparator(4), and outputs vibration with said particular frequency.