Method for Detecting And/Or Preventing Grind Burn

Abstract

The present invention provides a method of detecting and preventing grind burn from developing on a gear. The method includes performing acoustic emission testing while the gear is being ground during a grinding operation. The grinding wheel is evaluated during an eddy current test to detect material buildup on the grinding wheel which could cause grind burn. In addition, the method includes collecting swarf from the gear during the grinding operation and inspecting the swarf for an indication of grind burn.

What is claimed is: 
     
         1 . A method of determining whether a grinding wheel is properly dressed before a grinding operation, comprising:
 placing a probe in contact with the grinding wheel;   measuring an induced signal in the grinding wheel with the probe; and   comparing the measured induced signal to a threshold;   wherein, if the measured induced signal exceeds the threshold, inferring that the grinding wheel needs to be dressed or replaced.   
     
     
         2 . The method of  claim 1 , further comprising detecting the presence of material buildup on the grinding wheel. 
     
     
         3 . The method of  claim 1 , further comprising inferring the amount of material buildup on the grinding wheel is negligible if the measured induced signal is about 0 millivolts. 
     
     
         4 . The method of  claim 1 , further comprising generating a warning signal if the measured induced signal exceeds the threshold. 
     
     
         5 . The method of  claim 1 , wherein the threshold is a voltage or current. 
     
     
         6 . The method of  claim 1 , wherein the threshold is at least 0.25 millivolts. 
     
     
         7 . The method of  claim 1 , further comprising displaying the measured induced signal on a display monitor. 
     
     
         8 . The method of  claim 7 , wherein if the measured induced signal exceeds the threshold, a warning signal is displayed on the display monitor. 
     
     
         9 . The method of  claim 1 , further comprising inferring that the grinding wheel is properly dressed when the measured induced signal is less than the threshold. 
     
     
         10 . The method of  claim 1 , wherein the measuring an induced signal comprises measuring a voltage. 
     
     
         11 . The method of  claim 1 , wherein after the placing step, the probe induces an electric field in the grinding wheel. 
     
     
         12 . The method of  claim 11 , wherein after the inducing step, the probe detects the induced signal. 
     
     
         13 . A method of detecting grind burn on an object being ground, comprising:
 removing material from an object during a grinding operation;   collecting the material from the object with an element during the grinding operation;   inspecting the collected material for an indication of grind burn; and   inferring grind burn when the indication is a discoloration or change in thickness of the collected material.   
     
     
         14 . The method of  claim 13 , wherein the indication is substantially dark gray, blue, or black. 
     
     
         15 . The method of  claim 13 , wherein the element comprises filter paper or a magnet. 
     
     
         16 . The method of  claim 15 , further comprising placing filter paper near the object. 
     
     
         17 . The method of  claim 15 , wherein the filter paper is placed substantially beneath the object. 
     
     
         18 . The method of  claim 15 , further comprising aligning the filter paper with the object. 
     
     
         19 . The method of  claim 18 , further comprising correlating the location of the collected material on the filter paper with the location on the object from which the material is removed. 
     
     
         20 . The method of  claim 13 , further comprising using an instrument to inspect the collected material. 
     
     
         21 . The method of  claim 20 , wherein the instrument is a camera or microscope. 
     
     
         22 . The method of  claim 21 , further comprising magnifying the collected material to inspect for the indication. 
     
     
         23 . The method of  claim 13 , further comprising comparing the thickness of the collected material with a threshold thickness. 
     
     
         24 . The method of  claim 13 , further comprising generating a warning signal when grind burn is inferred.