Gear measurement pdf

gear axis X L flank orig~n measuring point Figure 1 : Substitute gear flank and measuring points The substitute gear flank [l, 21 is determined by the flank origin as the point of intersection of base helix and xy-plane. The mathematical parametric equation for . the helical involute flank contains only three coefficients as given below: View Lecture X - Gear Measurement.pdf from MEEG 219 at Kathmandu University. Metrology MEEG 219 Gear Measurement Gears Gears in Watch Gears in Lathe Gears in Differential Gear • Wheel provided NOTE 1 : The subscripts 1 and 2 of z 1 and z 2 denote pinion and gear. All calculated values in Table 4.1 are based upon given module m and number of teeth (z 1 and z 2).If instead, the modulem, center distance a and speed ratio i are given, then the number of teeth, z 1 and z 2, would be calculated using theformulas as shown in Table 4.2.. Table 4.2 The Calculations for Number of Teeth Gear Measurement 6. Gear Tooth thickness measurement 1. Gear tooth vernier caliper method •In gear tooth vernier method the thickness is measured at the pitch line. •Gear tooth thickness varies from the tip of the base circle of the tooth, and the instrument is capable of measuring the thickness at a specified position on the tooth. Calipers, micrometers, or special gages are used for span measurement. CMM GEAR INSPECTION Fig.10. CMM measurement of asymmetric gear CMM gear inspection (Fig. 10) allows mapping the whole surface of all teeth including the fillet profiles. However, it is typically used to control the involute accuracy. Although the gear tooth Basic gear system design process and gear measurement and inspection techniques will also be explained. In addition, the fundamentals of understanding the step‐wise process of working through the iterative design process required to generate a gear pair will be reviewed. •Diametrical Pitch is a measure of tooth size and equals the number of teeth on a gear divided by the pitch diameter in inches. Diametrical pitch can range from 1/2 to 200 with the smaller number indicating a larger tooth. See Figure 3. •Module is a measure of tooth size in the metric system. It equals the pitch pitch system. The diametral pitch of a gear is the number of teeth in the gear for each inch of pitch diameter. Therefore, the diametral pitch determines the size of the gear tooth. Pressure Angle Pressure angle is the angle at a pitch point between the line of pressure which is normal to the tooth surface, and the plane tangent to the pitch Gain an understanding of the information contained within a typical gear inspection report and the contents and meaning of the information contained within the gear charts, as well as the techniques used by the gear measurement system to assess gear quality. Exploration of basic Calculation from axial pitch measurement 11 fHN 20 µm 500:1 left Profile-Total Deviation right thread 1 69,516 70,266 72,266 79,266 79,858 80,516 tooth 121 thread 1 69,516 70,266 72,266 79,266 79,858 80,516 Q a [ .] n F fS 8 A 6 AA F fS_ re ( = 12)4 6 a n F fS 4 AA 6 AA F 2 6 12 FfS 20 µm 50:1 T oth ick nes rf yl d f s The measuring results from gear measurements taken on-site are digitally filed and can be used in a gear and spline analysis program. This program can be used to: • change the position of axis • overlay multiple measuring results for compari-sons, • select representations depending on the tooth thickness, The measuring results from gear measurements taken on-site are digitall