Belt tension adjustment and its ratio
As the furnace weighs 500 kg, power reduction system is needed to let the user to tilt the furnace with smaller torque. We have chosen belt and wheel for our power transmission.
Why do we choose belt rather than others?1. Belt can stand the transmission torque which is about 109 Nm to tilt the furnace
2. Cost of the belt is low compared with other power transmission method, for example, gearbox, chain
3. Limitation of our budget is the main reason for us to choose belt.
As we have decided to use gearbox for the motor. We can・t use another gearbox for manual operation.4. We use belt and wheel to fit the height of handle. For user friendly, the height of the handle should be about 1000mm height , belt is more
flexible for such height rather than using gear box.
In our design, there are two sets of wheel and belt for power transmission. The First set of wheels is diameter of 2 inch to 12 inch wheel for manual usage.
As the problem specification stated the ratio of revolution from handle to couple which is connected to the furnace is 6 to 1, the wheel ratio of handle to couple should be 6 to 1 too. Therefore we choose a wheel with 2・・ of diameter for the handle at the upper axis and another wheel with 12・・ of diameter for the couple which is connected to the furnace at the middle axis.
The second set of wheels is set up for the usage of motor, the diameter of the wheels are 5・・ and 12・・.
The wheel ratio of gear box and the wheel on the upper axis is 2・・ to 5・・, so the ratio of revolution from gear box to wheel on the upper axis is 5 to 2