Why is a single rope winding hoist equipped with a "small brake" - a motor brake

1、 Introduction

In the large family of mine hoists, single rope winding hoists occupy an important position. The accompanying electric motor brake, although seemingly inconspicuous, shoulders the responsibility of protecting key components and ensuring the smooth operation of equipment. Next, we will delve into why this series of elevators is equipped with electric motor brakes, as well as its unique structure and ingenious working principle.

2、 The core function of electric motor brake - guarding the reducer

Single rope winding elevators are usually equipped with a hard toothed planetary gear reducer, which plays a key role in the lifting system, responsible for precise control of speed and torque, and assisting the elevator in efficient operation. However, its "weakness" lies in its poor tolerance to impact.

At multiple critical nodes during the operation of the hoist, such as normal deceleration, parking, or emergency braking, the disc-shaped brake device on the drum will quickly apply the brakes, forcefully braking the drum. However, at this time, due to the large inertia of the motor rotor, even if the drum and the low-speed shaft of the reducer are already stationary, the motor will continue to rotate for a period of time based on inertia. This leads to a speed difference between the high-speed shaft of the reducer and the stationary low-speed shaft, resulting in harmful torque and impact phenomena. Frequent impacts undoubtedly cause serious damage to precision planetary gear reducers, greatly shortening their service life.

And the electric motor brake has emerged to solve this problem. It is like a loyal 'guardian', standing up at critical moments, accurately offsetting the harmful torque generated by the inertia of the motor, ensuring that the reducer is not impacted, maintaining stable operation, and laying a solid foundation for the long-term reliable operation of the hoist.

3、 Exploration of the Structure of Electric Motor Brakes

The electric motor brake is precisely installed next to the elastic rod pin coupling at the high-speed shaft of the reducer, adopting a vertically movable design. This layout enables it to efficiently cooperate with surrounding components and exert braking effect. Its structural composition is like a set of precise mechanical "building blocks", with each component tightly fitting together.

The electric motor brake mainly consists of a frame, arc-shaped brake shoe (with connecting rod at the lower end) device, oil cylinder device, spiral spring, adjusting nut, etc. Looking down from the top, the upper arc-shaped brake shoe device is very eye-catching. Its carefully designed arc radius perfectly matches the outer circle of the elastic rod pin coupling, ensuring a tight fit during braking and providing strong and uniform braking force. The spiral spring in the middle is like an energy storage device waiting to be activated, silently carrying the force conversion during the process of releasing and applying the gate. The lower oil cylinder device is the key to power drive, which is stably fixed on the frame and provides precise power support for the entire braking process. The rack is firmly rooted in the foundation through anchor bolts, providing a stable support foundation for the entire device. The connecting rod at the lower end of the arc-shaped brake shoe device cleverly passes through the spiral spring and is tightly connected to the piston rod of the oil cylinder device through an adjusting nut. This connection method not only ensures effective force transmission, but also allows for flexible adjustment of the coordination between various components to meet the braking needs under different working conditions.

4、 Decryption of the working principle of electric motor brake

The electric motor brake and the familiar disc brake device have similar principles, both following the basic rule of "hydraulic release and spring force braking".

When the oil cylinder is filled with pressure oil, the piston rod moves rapidly downwards like a soldier receiving instructions, driving the arc-shaped brake shoe to descend precisely through the connecting rod, making it move away from the outer circle of the elastic rod pin coupling. At the same time, the spiral spring is compressed, storing elastic potential energy. At this point, the brake release action is successfully completed, "releasing" the equipment for normal operation.

At the moment when the pressure oil in the oil cylinder is released, the spiral spring is instantly released from the compressed state, restoring its free state. With strong elastic force, it pushes the arc-shaped brake shoe to quickly rise and tightly press against the outer circle of the elastic rod pin coupling. Strong frictional force is generated instantly, and the braking process is completed in one breath.

The oil cylinder device is closely connected to the oil circuit of the disc brake of the hoist, which ensures that the action of the electric motor brake is always highly synchronized with the disc brake. In this way, during the critical moments of elevator deceleration, parking, and especially emergency braking, the electric motor brake can quickly respond and work together with the disc brake to absorb the majority of the rotational inertia of the electric motor rotor, making the high and low speed shaft movements of the reducer tend to be "synchronized", completely eliminating additional harmful torque, and protecting the gears of the planetary reducer from impact damage, greatly improving the service life of the reducer and safeguarding the safety and efficiency of mine lifting operations.

In summary, the electric motor brake equipped on the single rope winding hoist, with its unique function, exquisite structure, and scientific working principle, has become an indispensable key guarantee for the stable operation of the hoist, safeguarding the safety and efficiency of the entire hoisting system.