# MTSF Worm and Wheel Unit

## 創新系統

The Worm and Wheel Unit, "MTSF", allows to demonstrate the principle of a worm gear.

## 一般說明

The Worm and Wheel Unit, ,MTSF,, allows to demonstrate the principle of a worm gear.

The unit consists in a worm and a wheel. These parts are mounted on ball bearings and fixed to a vertical panel.

The worm and wheel are positioned a set distance apart to mesh correctly. Both parts run in bearings with the worm operating with an additional thrust bearing.

Attached to the end of the worm is a pulley of known effective diameter. This pulley helps to exert the effort required to raise a load. A cord is wrapped around the pulley and ends in a weight holder for applying the effort load.

Attached to the back of the wheel is another pulley of known effective diameter. This pulley is used for the loading of the system. Again a cord is wrapped around the pulley and ends in a weight holder to provide torque. This holder helps to exert the load onto the system via the weights set provided.

Forces are generated by the sets of weights and can be quickly and easily varied. Students add the weights to the pulley of the wheel and apply a suitable weight to the pulley of the worm in order to raise the load. Then, students record the weight values and calculate the efficiency, mechanical advantage and friction of the system.

## 練習和指導練習

### 手册中包含的指导实践练习

1. Learning the key variables and correlations of a worm gear.
2. Learning the basic terminology of gearing (number of teeth, reference circle and modulus).
3. Investigation of transmission ratio, torque, friction and selflocking.
4. Experimental determination of velocity ratio.
5. Comparison of the determined velocity ratio with the calculated value.
6. Determination of effort with variation of load.
7. Determination of friction with variation of load.
8. Determination of efficiency with variation of load.
9. Determination of limiting efficiency of the unit.