Abstract
A transmission accuracy of the gear is nearly known by measuring the pitch error in relation to the profile error at the same time. In order to auto-record the above two errors simultaneously, a measuring apparatus similar in mechanism to the gear hobbing machine, which has a gear to be measured and the several detectors of auto-recording electric comparator in place of the gear blank and the hob cutting edge respectively, is used. And by improving on both the arrangement of detectors and the recording system on this apparatus, they have been auto-recorded simultaneously, besides from this record a method for knowing a transmission accuracy has been tried. This method gives a very similar result to the one obtained by the single-flank rolling test, but it has some merits such as that the master gear and the pitch disk are not necessary, the errors at the face and the flank which cannot be shown by the test are known, and the factor of error can be analysed. Moreover this method can be considered as the auto-recording measuring method of profile of all teeth without using the base disk.
