purpose

Due to the limitations of building conditions, some theaters cannot directly transport sets or goods to the stage surface. Freight lifting platforms can be set up where the goods can reach, and the freight lifting platforms can transport the goods to the stage surface, rehearsal area, or set assembly workshop and other related high-rise buildings.

According to the different purposes and spaces, set the load, plan size, stroke, etc. of the cargo lifting platform. For platforms transporting standard containers, their load can reach 20.00t.

To ensure the safety of personnel and goods, electric lifting railings should be installed around the lifting platform and at the entrances and exits of each floor.

compose

The freight lifting platform consists of a platform body, a driving device, a transmission mechanism, a guiding device, a safety device, a mechanical locking mechanism, a counterweight (if possible), electrical equipment, a control system, etc. including:

The lifting platform should be equipped with auxiliary transmission devices to return to a safe position in case of emergency or accident;

☆ The brake system should have at least two independently controlled and operated brakes;

The lifting platform should be equipped with a guiding device to ensure that it does not tilt during lifting;

When the lifting platform is at the set elevation level, it should automatically lock so that it can maintain its position under maximum static load. The system should ensure that the equipment does not suddenly lose control when loaded or unloaded;

Where there is an exit on the lifting platform, a movable peripheral railing should be installed. As long as the lifting platform is not in the set position or loading and unloading position, the peripheral railing should be raised to protect personnel safety. The status of the railing should be monitored and interlocked with the lifting platform;

Unless the lifting platform stops at its normal position, all doors (provided by the building) should be closed or the perimeter railings raised. If the doors are not fully closed and the perimeter and platform railings are not raised, the lifting platform cannot be started. When the lifting platform reaches its normal position, the platform railing first automatically falls down, and then the outer railing falls down again. The status of all lifting railings should be displayed on the control panels of each floor. Platform railing refers to the adjustable railing set up in the direction of goods entering and exiting the lifting platform. It should be able to prevent items on the platform from rolling off during the movement of the lifting platform, and the platform railing should rise and fall together with the lifting platform. When the lifting platform reaches the loading and unloading position and stops steadily, the railing automatically falls down. The status of the platform railing should be monitored and interlocked with the lifting platform;

For the convenience of vehicle loading and unloading, the lifting platform can be fine tuned at each level and corresponding control buttons are set to make the platform floor level with the floor of that level.

structural design

1. Platform body

The platform body is a box shaped steel frame structure.

2. Drive system

According to the load, speed, pit and other conditions of the platform, hydraulic drive, gear rack drive, wire rope drive, large screw drive and other methods can usually be used.

(1) Hydraulic Drive

The hydraulic system has the advantages of good acceleration, compact structure, small size, light weight, and good lifting performance. Moreover, when the hydraulic source is located in other rooms, it can block the noise generated by the power source, making the operating noise relatively small.

But the hydraulic transmission scheme has the following problems:

☆ Hydraulic drive cannot set auxiliary transmission device. When a fault occurs, the lifting platform will be in a paralyzed state;

Due to the characteristics of the hydraulic system itself, hydraulic oil can cause certain pollution to the surrounding environment during installation, commissioning, and maintenance stages.

Due to the certain lifespan of hydraulic oil, it must be replaced by professionals every certain number of years, resulting in high maintenance costs and pollution;

The lifting platform uses two hydraulic cylinders for lifting, making it difficult to solve the synchronization problem during the lifting process;

Using two hydraulic cylinders for lifting, the sealing ring of the cylinder is prone to breakage when biased, making replacement difficult and costly;

Hydraulic cylinders are prone to leakage, causing the lifting platform to sink and inaccurate positioning.

(2) Gear rack self lifting drive

1) Gear rack drive has the advantages of good horizontal performance, unlimited travel, and high positioning accuracy.

Some measures can be taken in the design to overcome the shortcomings of hydraulic drive, including:

☆ Set up an auxiliary drive device to use the auxiliary drive to lift the lifting platform when the main drive motor and its control unit fail, ensuring that the lifting platform can safely transport goods to the destination layer under any circumstances;

☆ The system accuracy is easy to control and will not cause pollution to the environment;

During the entire lifespan, apart from normal maintenance operations, most components will not be damaged and do not require replacement;

☆ One motor drive with good synchronization performance;

2) The disadvantage is that the machining and installation accuracy requirements for gear rack transmission are relatively high; The noise is slightly high, but it can be reduced by using a soundproof cover lined with sound-absorbing materials.

(3) Wire rope winch drive

The wire rope winch drive has the characteristics of easy installation and maintenance, low noise, and relatively economy. Compared with gears and racks, it is difficult to maintain levelness when the load changes.

(4) Large spiral drive

The large spiral drive is suitable for platforms with shallow excavation depths, with a minimum excavation depth of 1.60m. The transmission system layout is simple and convenient, with loose installation requirements, but the price is relatively expensive.

3. Guidance and other institutions

Due to the large load-bearing capacity of the freight lifting platform, it is recommended to use a guide rail shoe guide.

When the freight lifting platform is installed inside the shaft, rolling shutter doors are usually installed at the entrance of each floor of the shaft. The rolling shutter door is made of aluminum or steel, and the maximum horizontal force acting on the rolling shutter door is 1.50 kN/m. To ensure smooth entry and exit of goods, the maximum height of the box cover for storing the rolling shutter door on the upper part should generally not exceed 0.80m.