Spacing/Runout Check

Once a gear is defined and the reference frame has been established, we can configure and teach a Spacing/Runout Check into the program database. This gear check item will give the user options for 5 evaluations relating to Spacing/Runout. It can then output reports to help evaluate that data relative to the gear definition.

Teaching Spacing/Runout Check

Check Diameter- The diameter at which the check has to be performed. For bevel gear, it is measured at large end

Check Face (%) - The depth in percentage of face width at which the profile check has to be performed. For a bevel gear, it is measured from the small end to the large end.

The available evaluations are:

Index Variation (vx): The displacement of any tooth from its theoretical position.

Pitch variation (vp): The algebraic difference between the true (theoretical) pitch and the actual measured pitch of a gear, evaluated in the transverse plane.

Spacing Variation (vs): The difference between two adjacent pitch variation values.

Thickness variation (vt): Deviation from the nominal value of normal circular tooth thickness.

Runout (vr): The maximum variation of the distance between a surface of revolution and a datum surface, measured perpendicular to that datum surface.

All of these evaluations have the following options:

Enable: Check this box to enable the check for Index, Spacing, Runout, Pitch and/or Thickness variation.

Output: Enter a name for the report. Defaults are vx, vs, vr, vp & vt.

Report: Check this box to create a supplemental graphical report.

Name: Enter a name for the graphical report

Reporting Index Variation

Below is an example graphical report for the index variation.

X-axis is the tooth number. Y-axis represents the amount of index deviation for left flank (top graph) and right flank (bottom graph). Please note the sign is inverted for upper and lower graphs.

Total index variation is the maximum algebraic difference between the extreme values of index variation.

Reporting Pitch Variation

Below is an example graphical report for the pitch variation.

X-axis is the tooth number. Y-axis represents the amount of pitch deviation for left flank (top graph) and right flank (bottom graph). Please note the sign is inverted for upper and lower graphs.

The worst pitch variation is shown in the title.

Reporting Spacing Variation

Below is an example graphical report for the spacing variation.

X-axis is the tooth number. Y-axis represents the amount of spacing deviation for left flank (top graph) and right flank (bottom graph). Please note the sign is inverted for upper and lower graphs.

The worst spacing variation is specified in the report title.

Reporting Thickness Variation

Below is an example graphical report for the thickness variation.

X-axis is the tooth number. Y-axis represents the thickness deviation of each tooth at the specified check diameter. Nominal, minimum, and maximum tooth thicknesses are noted on the title.

Reporting Runout

Below is an example graphical report for the runout.

X-axis is the tooth number. Y-axis represents the deviation on each tooth.

The peak-to-peak runout deviation is shown in the title.

Eccentricity is calculated by best-fitting a circle based on data points then determining the positional deviation from the theoretical center of the gear. At Tooth value in the title designates the direction of the eccentricity. For the example report below, the actual center of the rotation is off by 0.00097 inches in the direction toward teeth #19 & #20.

Additional Reporting

Points from the lead check are available in Feature Database for additional analysis such as Cloud-to-CAD. Furthermore, a text file containing the raw data output will be saved in C:\ProgramData\QxSoft\CMM-Manager ####\Gear (#### is the version of your CMM-Manager).