The working principle of a stage electric hoist involves the use of an electric motor to generate mechanical power, which is then transmitted to a lifting mechanism to raise and lower loads. Here is a step-by-step breakdown of the working principle:
The stage electric hoist is equipped with an electric motor, typically an induction motor. When electric power is supplied to the motor, it generates a rotating magnetic field.
The rotating motion generated by the motor is transmitted to a gearbox or transmission system. The gearbox serves to adjust the speed and torque of the motor's rotation.
The transmission system is connected to the lifting mechanism, which can take the form of a drum or a chain hoist. The lifting mechanism is responsible for winding or unwinding the lifting cable or chain.
Lifting Cable or Chain:
In the case of a drum-based stage electric hoist, a steel cable is wound around the drum. For chain hoists, a lifting chain is used. The load is attached to the end of the cable or chain.
The hoist is equipped with a control system that allows the operator to regulate the movement of the load. This control system includes a control pendant or remote control device with buttons or switches for lifting, lowering, and stopping the hoist.
Limit switches are integrated into the hoist to set upper and lower travel limits. These switches automatically stop the hoist when the load reaches the desired height or lowers to the lowest point. Limit switches enhance safety and prevent overtravel.
A brake system is incorporated into the hoist to hold the load securely in place when the hoist is not actively lifting or lowering. This brake engages when the motor is not running and releases when the motor is activated.
Modern stage electric hoists include various safety features, such as overload protection devices and emergency stop controls. These features are crucial for ensuring the safety of both the equipment and the operators.
The operator uses the control pendant or remote control to command the hoist to lift or lower the load with precision. The electric motor's speed and direction are controlled through the electrical signals from the operator.
Some stage electric hoists may be integrated into automation systems for synchronized and programmed movements. This allows for intricate and coordinated performances, where multiple hoists can be controlled simultaneously.
In summary, the electric motor provides the power needed to drive the lifting mechanism, and the control system allows for precise and controlled movements. The safety features ensure the reliable and secure operation of the stage electric hoist during performances in the entertainment industry.