Selection of Worm Gear Motor: Comparison of the Importance of Torque and Power

Case Background

• Total load mass: 100 kg
• Maximum slope angle: 35°
• Maximum speed on flat ground: 0.5 m/s
• Friction coefficient during climbing: 0.2

Calculation of Torque and Power

1. Torque Requirement for Climbing
   When climbing, the device needs to overcome gravity and friction. The driving torque can be calculated using the formula:
   $$M=M^f+fR=0.007\times 40\times 9.8\times \cos (35^{\circ })+40\times 9.8\times \sin (35^{\circ })\times 0.1=24.73\text{Nm}$$
   The maximum torque required by each motor after the gear reduction is:
   $$M^{\text{motor}}=\genfrac{}{}{0ex}{}{24.73}{2}=12.37\text{Nm}$$
   This indicates that during climbing, the motor needs to output a significant amount of torque.
2. Power Requirement for Flat Ground Operation
   When operating on flat ground, the device needs higher speed, but the torque requirement is relatively small. The power can be calculated using the formula:
   $$P=F\times V=200\times 1=200\text{W}$$
   Considering the transmission efficiency (assuming a total efficiency of 0.88), the actual required power is:
   $$P^{\text{actual}}=\genfrac{}{}{0ex}{}{200}{0.88}=227\text{W}$$
   This indicates that during flat ground operation, power is the main consideration.

Comparison of the Importance of Torque and Power

• Importance of Torque: When climbing, the device needs sufficient torque to overcome gravity and friction. Torque is the key factor determining whether the motor can operate normally. If the torque is insufficient, the motor will not be able to drive the device uphill.
• Importance of Power: When operating on flat ground, the device needs higher speed, and power becomes the main consideration. Power determines the motor's output capability at high speeds. If the power is insufficient, the device will not be able to reach the required speed.

Conclusion