Vibration testing system for gear sets

• US 4,252,023 A
• Filed: 11/27/1979
• Issued: 02/24/1981
• Est. Priority Date: 11/27/1979
• Status: Expired due to Term

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Pomernacki, Henry
• Primary Examiner(s): Gill, James J.
• Application Number:
  US06/100,619
• Time in Patent Office: 455 Days
• Field of Search: 73/593, 73/162, 33/179.5
• US Class Current: 73/593
• CPC Class Codes: G01M 13/021 Gearings
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis

Abstract

A pair of gears, which form a gear set, are tested by mounting the gears on parallel axis spindles which are located at a fixed center distance. One of the parallel axis spindles is contained in a spindle housing that is rigidly mounted to a massive base. The other gear of the set is contained in a spindle housing which is supported on top of a pair of parallel leaf springs that are connected to the base. The spindle in the spindle housing that is rigidly mounted on the base carries a pulley at its end that is remote from the gear set which is coupled through a drive belt and a second pulley to a drive motor. The spindle in the resiliently mounted spindle housing on the leaf springs is coupled to an eddy current brake at its end which is remote from the gear set. An accelerometer, which is coupled to a conventional electronic output indicator, is mounted on the resiliently mounted spindle to provide indications of the vibrations caused by the gear sets. The gears of the gear set are driven by the drive motor so that their tooth-to-tooth frequency is approximately the same as the resonant frequency of the resiliently mounted spindle housing. The construction of the testing system in the described manner substantially improves the signal-to-noise ratio of the output signal that is obtained from the accelerometer.

Claims

1. A testing system for testing gear vibration noises from a first and a second gear of a meshing gear set comprising a first rigidly suppported rotatable spindle means having a longitudinal axis and coupled to said first gear, a second rotatable spindle means having a longitudinal axis that is aligned substantially parallel to the longitudinal axis of the first spindle means and coupled to said second gear, drive means coupled to one of said spindle means for driving said coupled spindle means, resilient mounting means coupled to said second spindle means for resiliently supporting said second spindle means so that said second spindle means and said resilient means comprise a resonant system which has a resonant frequency which is approximately equal to the tooth-to-tooth frequency of said first and second gears at a predetermined drive frequency of said drive means, accelerometer sensing means coupled to said second spindle means for sensing the vibration noises caused by said first and second gears and output means coupled to receive the signal produced by said accelerometer sensing means.

2. A testing system, as claimed in claim 1, further comprising a base wherein said resilient means comprises a pair of parallel oriented generally rectangular-shaped flat leaf springs which are coupled to said base and said second spindle means so as to support said second spindle means above said base with said leaf springs projecting substantially normally to said base.

3. A testing system, as claimed in claim 1, further comprising a brake means wherein the spindle means that is not coupled to said drive means is coupled to said brake means.

4. A testing system, as claimed in claim 3, wherein said brake means comprises an eddy current brake means.

5. A testing system, as claimed in claim 3, wherein said drive means is coupled to said first spindle means and said brake means is coupled to said second spindle means.

6. A testing system, as claimed in claim 5, wherein said brake means comprises an eddy current brake means.

7. A testing system, as claimed in claim 1, wherein said accelerometer sensing means is positioned in a plane with the longitudinal axes of said first and second spindle means so that said axis of said second spindle means lies intermediate said axis of said first spindle means and said accelerometer sensing means.

8. A testing system, as claimed in claim 7, further comprising a brake means wherein the spindle means that is not coupled to said drive means is coupled to said brake means.

9. A testing system, as claimed in claim 8, wherein said brake means comprises an eddy current brake means.

10. A testing system, as claimed in claim 9, wherein said drive means is coupled to said first spindle means and said brake means is coupled to said second spindle means.

11. A testing system, as claimed in claim 10, further comprising a base wherein said resilient means comprises a pair of parallel oriented generally rectangular-shaped flat leaf springs which are coupled to said base and said second spindle means so as to support said second spindle means above said base with said leaf springs projecting substantially normally to said base.