直線距離測定法による歯車ピッチ誤差の測定について

抄録

Pitch error measurements on individual gears may be carried out in two general ways : (a) Direct Angular Measurement (b) Step by step Measurement.
The second method is more widely used. However, the disadvantage of this method is that measuring errors are cumulative.
The following three are the main causes of measuring error : (1) Dispersion of readings (2) Displacement of reference point (3) Changes in room and test gear temperature.
The method of dividing teeth into groups is very useful for minimizing the influence of the above errors on the result. Here the number of teeth of a test gear Z is divided into the number of groups S and if the number of teeth in each of the groups is s, Z=S×s.
The proper number for S is about √2Z, and consequently s is √Z/2.
In this method the measuring error can be expressed as follows :
σ_FK_??_√S/2 · σ= (2Z) ^1/4/2 · σ
Where σ is the standard deviation of the dispersion of readings.
The usefulness of this method is confirmed by experiment.