Abstract: Model YA7232A Worm Gear teeth grinder is featured by the electronically controlled speed variation and grinding helical gears without differential mechanism. Starting from the improvement of the tooth accuracy in the gear grinding, this paper deals emphatically upon the principles for grinding gears without differential mechanism and gear profile generation, It also gives a brief description of the drive systems and the machine in general. The equations for the rotating speed ratio and the axis moving speed ratio were first studied. In case the required helical gear is to be ground, the above mentioned equations should be satisfied. The teeth profile of the helical gear is generated by involution of the touch zone on the straight generating line. Furthermore the effect of the regular and standard engagement of the gears upon the accuracy of the gears were also discussed. After the analysis, it was pointed out that the precision of the train of the grinding worm spindle and that of the worm pitch as well as that of the overall drive train were the main factors affecting the accuracy of the workpiece Hence, the measure for the improvement of the construction and ensurance of the working accuracy were recommended and accepted. By doing so, the remarkable result has been achieved. At present the spur gears can be ground to class 4-5JB179-81 and class in most cases. The accuracy of the helical gear grinding reaches class g. thus the domestic needs can be satisfied.