The double flank gear rolling inspection is an easy and quick inspection method for gears. The inspection process can be carried out on the shop floor. It immediately enables the user to evaluate gears with regard to the total errors caused in production.
The double flank gear rolling inspection is, if used with modern evaluation equipment such as a PC, hardware and software, a very efficient and quick way of ensuring quality without any problems. Below is a selection of typical workpieces:

Measured values and evaluation:
The basic principle of the double flank gear rolling inspection is based on a master gear (a near perfect gear) and a gear (= workpiece) are in rolling contact, free from backlash. The inspection instrument has one rotational axis which is fixed and one which is movable. The centre distance variations during the rolling process are caused by form errors on the workpiece and are the basis for the evaluation of the inspection. In the following are the individual inspection parameters in more detail:

Double flank radial error Fi'': is the fluctuation of the centre distance a'', i.e. Fi'' is the difference between the largest and the smallest centre distance a'' within one revolution of the inspected gear (DIN 3960 / 3963). Cause: All gear errors can influence the result.

Double flank tooth-to-tooth deviation fi'': is the largest difference in the centre distance a'' that occurs within an angle of rotation corresponding to the engagement of one tooth (DIN 3960 / 3963). Cause: Errors in certain tooth segments or in individual teeth.

Double flank runout deviation Fr'': is the long wave-length component of the double flank composite error. It is obtained by drawing a “mean line” into the test diagram of the double flank gear rolling inspection, whereby the short wave-length components are suppressed. The runout deviation Fr'' is therefore the distance between the highest and lowest point of the mean line (DIN 3960 / 3963). Cause: Eccentricity of the gearing in the measuring plane perpendicular to the centre line of the gear, and by non-uniform space widths caused by pitch deviation.

Short wave-length component fk'': is accrued from the difference between the recorded test diagram lines of the gear roll error Fi'' and the ‘mean line’ of the runout deviation Fr'' Cause: Waviness in the profile deviations and flank line deviations will have an influence.