Abstract
The authors developed the new type hourglass worm gear of plastic involutes helical gear wheel. The theory the production method of the steel worm and the plastics wheel are reported. The results of the experience of the hourglass worm gear are report. A set of new worm gears is manufactured, and he accuracy of transmission by measured tested by the power absorption type testing machine. The efficiency was compared with the traditional cylindrical worm gear of steel worm and copper alloy wheel. The efficiency of the hourglass worm gear was over 85%, when the reduction ratio 18.5, module 2 and out put 60 Nm. And the efficiency of the cylindrical worm gear was about 75%, when the reduction ratio 20, module 2 and out put 60 Nm. Numerical works obtains contact lines.
