Forced harmonic vibration master gear

• US 7,210,345 B2
• Filed: 04/18/2005
• Issued: 05/01/2007
• Est. Priority Date: 06/30/2004
• Status: Expired due to Fees

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Narh, Enoch
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US11/108,212
• Publication Number:
  US 20060000268A1
• Time in Patent Office: 743 Days
• Field of Search: 731/62, 731/181, 735/93, 335/011.9, 335/011.3, 335/017, 335/018, 335/011.6, 744/57
• US Class Current: 73/162
• CPC Class Codes: G01M 13/021 Gearings

Abstract

A forced harmonic vibration master gear for use in a device for detecting imperfections in a production gear includes a gear body having a plurality of gear teeth. Each of the plurality of gear teeth has a graduation of material added thereto extending from a form diameter of each tooth to an end of the tooth to decrease the pressure angle of the tooth. The forced harmonic master gear when used to test an unacceptable production gear, induces in the unacceptable production gear, when rotating, a vibrational force that is at least 50 percent greater than a vibrational force exhibited by the unacceptable production gear when a standard master gear is used to test the unacceptable production gear, in at least one band of 70 Hz to 150 Hz, 151 Hz to 300 Hz, 301 Hz to 550 Hz, 551 Hz to 1250 Hz and 1251 Hz to 2000 Hz. When the forced harmonic master gear is used to test an acceptable production gear, the acceptable production gear, when rotating, exhibits a vibrational force that is no more than 25 percent greater than a vibrational force exhibited by the acceptable production gear when a standard master gear is used to test the acceptable production gear.

Claims

1. A forced harmonic vibration master gear for use in a device for detecting imperfections in a production gear including burrs, grind marks, plus material in tooth formation, waviness, improper finish, imperfections in the involute wherein said production gear is driven by a driving torque and is enmeshed with said forced harmonic vibration master gear wherein said forced harmonic vibration master gear is configured similar to said production gear wherein said forced harmonic vibration master gear when rotating induces exaggerated energy levels in said production gear to cause an increase in vibrational force of said production gear wherein said increased vibrations are forced harmonic vibrations whenever the involute of said forced harmonic vibration master gear encounters an imperfection in or on the involute form of said production gear, said forced harmonic vibration master gear comprising a standard conventional master gear body having a plurality of gear teeth each of said plurality gear teeth having a graduation of material added thereto extending from the form diameter of each tooth to an end of the tooth as a means to decrease the pressure angle and cause an increase in contact pressure of the tooth so that said forced harmonic vibration master gear, when rotating as enmeshed with said driven production gear causes an increase in vibrational force of said production gear when the involute of said master gear encounters imperfections in or on the involute form of said forced harmonic vibration production gear.

2. The forced harmonic master gear in accordance with claim 1 wherein when the forced harmonic master gear is used to test an unacceptable production gear, the unacceptable production gear, when rotating, exhibits a vibrational force that is at least 50 percent greater than a vibrational force exhibited by the unacceptable production gear when a standard master gear is used to test the unacceptable production gear, in at least one band of 70 Hz to 150 Hz, 151 Hz to 300 Hz, 301 Hz to 550 Hz, 551 Hz to 1250 Hz and 1251 Hz to 2000 Hz, and wherein when the forced harmonic master gear is used to test an acceptable production gear, the acceptable production gear, when rotating, exhibits a vibrational force that is no more than 25 percent greater than a vibrational force exhibited by the acceptable production gear when a standard master gear is used to test the acceptable production gear.

3. The forced harmonic master gear in accordance with claim 2 wherein when the forced harmonic master gear is used to test an unacceptable production gear, the unacceptable production gear, when rotating, exhibits a vibrational force that is at least 65 percent greater than a vibrational force exhibited by the unacceptable production gear when a standard master gear is used to test the unacceptable production gear.

4. The master gear in accordance with claim 2 wherein when the forced harmonic master gear is used to test an acceptable production gear, the acceptable production gear, when rotating, exhibits a vibrational force that is no more than 20 percent greater than a vibrational force exhibited by the acceptable production gear when a standard master gear is used to test the acceptable production gear.

5. The master gear in accordance with claim 1 wherein the forced harmonic vibration master gear and said standard master gear as test gears have 57 teeth in a comparison measurement of substantial vibrational forces measured for standard and forced harmonic master gears in a single flank test wherein a significant increased vibrational force difference is present between values measured between the results of said forced harmonic vibration master gear and said standard master gear.

6. The forced vibration master gear in accordance with claim 1 wherein the graduated material increase is added to each of the teeth is at least about 0.0002 inches as a means to result in a decrease in the pressure angle of each tooth of at least about 0.059 degrees for forced harmonic vibration master gear teeth having a working depth of 0.1948 inches to cause an increase in contact pressure, of each tooth such that increased contact pressure causes an increase in vibrations in said production gear whenever the involute of the forced harmonic vibration master gear encounters imperfections in or on the involute form of the production gear, wherein said increased vibrations are said forced harmonic vibrations.

7. The master gear in accordance with claim 1 wherein the reduction in the pressure angle of each tooth is at least about 0.059 degrees for a gear having a working depth of 0.1948 inches, the distance from the form diameter to the outside diameter.