Travel distance

The long operating path will directly amplify the mechanical loss and operating deviation of the equipment, which is the core source of all working conditions problems. First of all, the main girder, end beam, and travel mechanism of the crane need to be continuously operated for a long time, and the fatigue and wear rate of the metal structure will be greatly accelerated. Compared with short-stroke equipment, the probability of deflection deformation of the main girder and loosening of components is significantly increased. Secondly, long-distance operation will accumulate positioning errors, and the small travel deviations that can be ignored in the short stroke will be continuously magnified in the 100-meter stroke, which will eventually lead to inaccurate alignment of the hook and reduced operating accuracy, which cannot meet the needs of precision hoisting.

Runway alignment

The crane operating track is the basis for the equipment to walk, and the installation accuracy, flatness, and straightness of the track directly determine the stability of long-stroke operations. Under short-stroke conditions, the slight high-low deviation, left-right offset, and gap error of the track will not have a significant impact on the operation of the equipment, but in the long-distance track system, small deviations will form a cumulative effect. Local unevenness of the track will cause bumps and catons when the crane is travel, and long-term operation will wear out the wheels, reducers, and travel motors. The deviation of the left and right alignment of the track exceeds the standard, which will cause the crane to gnaw the rail.

Load stability

Heavy object shaking and load offset are common problems in long-travel overhead crane operations. During the long-distance travel of the crane, the inertial force will continue to act on the lifting of heavy objects during the whole process of starting, running at uniform speed, decelerating and stopping. Short-stroke operations start and stop frequently but the stroke is short, and the shaking amplitude is controllable. During the long-stroke uniform speed operation phase, the inertia generated by the continuous movement of the equipment will cause the heavy objects to swing continuously. Once the track bumps, wind speed interference, and motor speed fluctuations are encountered, the load shaking will intensify sharply. Unstable loads will not only reduce the accuracy of hoisting, which is likely to cause material collisions and workpiece damage, but also increase the force load on the equipment, resulting in uneven force on the core components such as the main girder, wire rope, hook, etc., accelerate the aging of the components, and even cause safety accidents caused by heavy objects falling, which greatly limits the safety and stability of long-travel overhead crane operations.

Travel frequency

Most of the production scenarios adapted to long-stroke working conditions are continuous and large-volume operations. The daily operating frequency and continuous operation time of the crane are higher than that of ordinary equipment. High-frequency and long-distance reciprocating operation will keep the travel mechanism, transmission system, and electrical control system in a high-load working state for a long time. The transmission components such as motors, frequency converters, and reducers continue to heat up, which is prone to overheating protection and performance attenuation. The high-frequency friction of mechanical components such as wheels, bearings, and brakes doubles the wear speed, and it is extremely prone to problems such as brake failure and travel caton. At the same time, the continuous vibration caused by high-frequency operation will lead to loose equipment bolts, aging lines, and poor contact with electrical components, which will greatly shorten the service life of the equipment, increase the probability of downtime and maintenance, and affect the continuous production of enterprises.

Single-girder cranes

Henan Mine Crane single-beam bridge crane is widely used in light and medium-sized long-stroke operation scenarios with the advantages of light structure, low cost and easy installation. In long-stroke and low-load working conditions such as light-duty factories, small storage workshops, and assembly line auxiliary hoisting, the cost-effective advantages of single-girder cranes are extremely prominent. However, it is limited by the rigidity and bearing capacity of the single-beam structure, the span and deformation resistance of the main girder are limited, and the main girder is prone to deflection and equipment shaking during long-distance heavy-duty operation. Therefore, it is only suitable for light-load, low-frequency, medium- and small-span long-stroke conditions, and cannot meet the needs of heavy-duty industrial operations.

Double-girder cranes

Double-girder bridge crane is the optimal core model for long-stroke, medium- and heavy-duty working conditions. The equipment adopts a symmetrical structure of double main beams, with strong overall rigidity, good load-bearing performance and excellent deformation resistance, which perfectly solves the pain points of long-distance heavy-duty single-girder cranes that are easy to deform and have poor stability. The double-beam structure can evenly disperse the vibration, inertial force and load pressure generated during long-stroke operation. The deflection deformation of the main girder is very small, and the whole process runs smoothly, greatly reducing the probability of heavy objects shaking and equipment deviation. In long-stroke heavy-duty scenarios such as heavy industrial plants, large-scale processing workshops, and heavy equipment transshipment, the stability, durability, and operating efficiency of double-girder cranes far exceed that of single-girder models.

Top-running cranes

Henan Mine Crane upper rail crane is a classic rail design model adapted to long-stroke operation. Its travel wheels are directly laid on the top of the crane beam track, and the track has strong load-bearing capacity, uniform force, and low operating resistance. Compared with side-mounted and bottom-mounted cranes, the overall stability of the upper rail structure is higher, and it is not easy to offset and caton during travel, and the probability of gnawing the rail is extremely low. The core advantage of this design is that it has excellent smoothness and high fault tolerance for long-distance operation, can adapt to small deformation of long-distance tracks, and continuously maintains stable travel. At the same time, the drive system of the upper rail crane is reasonably arranged, the transmission efficiency is high, it supports long-distance high-speed and smooth operation, and the equipment maintenance is convenient, which is suitable for long-term high-frequency and long-stroke operations.

Long-span applications

Long-travel working conditions are often accompanied by the needs of long-span operations. The long-span long-travel overhead crane is specially designed for the operation scenarios of wide factories and long passages. This type of model is based on the double-beam upper rail structure. By optimizing the cross-section of the main girder, strengthening the end beam structure, and upgrading the travel balance system, it solves the problems of equipment shaking, deformation, and deviation under long-span and long-distance dual working conditions. At the same time, it is equipped with an enhanced travel drive and stabilization system, which can maintain accurate, stable and efficient hoisting operations in a wide range of working areas. It is widely used in large steel structure factories, power equipment workshops, large-scale warehousing in ports and other large-space industrial scenes.

Travel drive system

The travel drive system is the core power core of long-travel overhead crane, which directly determines the smooth operation and battery life of the equipment. Long-travel overhead crane must adopt a two-sided synchronous drive system to replace the traditional one-sided drive structure to ensure that the power output of the travel mechanism at both ends of the crane is balanced, and the problems of deviation and rail gnawing caused by power deviations are effectively avoided. The drive system needs to be equipped with a hard tooth surface reducer with a reasonable reduction ratio, which has high transmission efficiency, wear resistance and wear resistance, and can be adapted to high-frequency and long-distance continuous operation to reduce transmission loss and the probability of failure.

Wheel configuration

Reasonable wheel configuration is the key to solving the serious problems of long-stroke deviation and wear. Conventional short-stroke cranes use a four-wheel basic configuration, while long-travel overhead cranes need to optimize the wheel structure according to the stroke length, equipment weight, and load capacity, and adopt a balanced multi-wheel configuration. By increasing the auxiliary travel wheels, the contact pressure between the equipment and the track is dispersed, and the problems of excessive wear and track pressure loss caused by excessive pressure on a single wheel are avoided. At the same time, it is equipped with accurate wheel positioning technology to ensure that the parallelism and verticality of the wheels are up to standard, and the phenomenon of rail gnawing and deviation is eliminated structurally.

Motor and VFD control

Long-travel overhead crane must not use ordinary fixed-speed motors, it must be equipped with a dedicated frequency conversion motor + VFD frequency conversion control system. The frequency conversion control system can realize stepless speed regulation, accurately control the whole process of starting, acceleration, uniform speed, deceleration, and parking of the crane, and completely solve the problem of large start-stop impact and unstable speed of the fixed-speed motor. Speed up slowly at the beginning to avoid the sharp shaking of heavy objects caused by the sudden increase in inertia. Keep the speed constant during operation to ensure smooth long-distance travel. When parking, it descends at a uniform speed, with precise alignment and no offset. At the same time, the VFD system has overload protection, overheating protection, and fault self-test functions, which can effectively avoid motor overload and electrical failure caused by high-frequency and long-distance operation, improve equipment operation safety and stability, and reduce energy consumption and operation and maintenance costs.

Anti-sway system

The sway control system is the core configuration of long-travel overhead crane to improve the accuracy and safety of operations. Inertial shaking and orbital bumps caused by long-distance travel are the main problems that affect the operation effect. The intelligent sway control system can collect equipment operating speed, displacement, and load swing data in real time, accurately correct the start-stop rhythm and operating speed through algorithms, actively offset the inertia of heavy objects, and control the swing amplitude of hoisted heavy objects to a very small range. Even in the working conditions of ultra-long stroke, high-speed operation, and frequent start and stop, the load stability can be guaranteed, and the problems of material collision and workpiece damage can be eliminated.

Runway design

The track design adapted to long-stroke working conditions is the basis for the long-term stable operation of the equipment. The long-travel overhead crane track needs to use high-strength special steel rails, which have strong load-bearing capacity, wear-resistant and deformation-resistant, and can withstand the weight and heavy-duty pressure of the equipment for a long time. Track installation needs to strictly control the straightness, level, and parallelism, and accurately calibrate the whole process to eliminate local height differences and left-right offsets. At the same time, the temperature expansion joints need to be reserved to adapt to the thermal expansion and contraction of the track caused by seasonal temperature differences, so as to avoid deformation and extrusion of the track.

Travel speed

The speed setting of Henan Mine Crane Long-runway overhead crane needs to take into account efficiency and stability, and must not blindly pursue high speed. According to different job scenarios, the hierarchical speed mode needs to be optimized. The no-load return journey can appropriately increase the operating speed, shorten the no-load time, and improve work efficiency. Heavy-duty travel needs to reduce the uniform speed, reduce inertial shaking, and ensure stable load. The low-speed fine-tuning mode is used in the close-range alignment stage to improve accuracy. Through the frequency conversion system, exclusive speed parameters are customized to realize the differentiated operating mode of “high-speed rush, low-speed alignment, and stable heavy-duty travel”, and the efficiency of long-stroke operations is maximized under the premise of ensuring equipment safety and stable load.

Positioning accuracy

The accumulation of positioning errors in long-track operation is the main problem in precision operations, and the positioning accuracy can be improved through multiple technical optimizations. First of all, it is equipped with an intelligent positioning sensor system to accurately collect crane travel displacement data in real time and automatically correct the position deviation caused by long-distance operation. Secondly, optimize the logic of frequency conversion and speed regulation, and automatically slow down and buffer at the end of the parking stage to eliminate the alignment deviation caused by inertial sliding. Finally, with the dual protection of mechanical limit + electronic limit, the operating point is accurately locked.

Smooth acceleration

Sudden acceleration and rapid deceleration are the core causes of heavy objects shaking and equipment loss. Long-runway overhead crane needs to optimize the acceleration curve and set a flexible start-stop program through the VFD frequency conversion system to achieve gradual acceleration and buffered deceleration. Abandon the instantaneous start-stop mode of traditional equipment, let the speed transition smoothly, no impact, no setbacks, and greatly reduce the impact of inertial forces on the load, equipment structure, and transmission components. Stable acceleration and deceleration control cannot only completely improve the problem of heavy object swing and improve operation safety, but also reduce the fatigue and wear of mechanical components, reduce the probability of equipment failure, and extend the service life of the crane.

Rail alignment

Orbital deviation is the main source of long-travel overhead crane failure, and regular orbital calibration is the key to maintaining the high-performance operation of the equipment. Enterprises need to establish a normalized orbit detection and calibration mechanism, regularly use professional instruments to detect the straightness, level, and spacing deviations of long-distance orbits, and correct orbital deformation, offset, and height inequality in a timely manner. Strengthen, repair, and replace the parts of the track that are loose, have too large gaps, and are severely worn in time to prevent small deviations from accumulating into large-scale failures. At the same time, in view of the problems of foundation settlement and temperature deformation of the plant, the overall track leveling and calibration are regularly carried out to ensure the precise alignment of the long-distance track throughout the process, and to solve the problems of rail gnawing, deviation, and caton from the root cause.

Maintenance planning

Long-runway overhead crane operates at high frequencies and long distances for a long time, and the loss of components is faster. Scientific operation and maintenance planning is the core of ensuring the continuous high performance of the equipment. It is necessary to formulate a maintenance plan for exclusive long-stroke equipment, and check the operating status of the travel motor, reducer, wheel, and brake system daily. Weekly detection of track flatness, drive synchronization, and sway control system sensitivity. Lubricate the transmission components, tighten the wiring, and calibrate the positioning system every month. Do quarterly structural flaw detection of the whole machine, comprehensive track calibration, and in-depth inspection of the electrical system. Investigate potential faults in advance, replace worn parts in time, avoid small problems accumulating into downtime failures, reduce operation and maintenance costs, and ensure long-term stable and efficient operation of equipment.

Load capacity

Load is the core and primary basis for selection, and it needs to be accurately selected in combination with the actual maximum lifting weight and the long-term average operating load.

Span and lift height

The span of the plant and the lifting height of the material directly determine the structural design and configuration level of the Henan Mine Crane crane. When large-span factories are equipped with long-stroke working conditions, high-rigidity double-beam structures need to be preferred to strengthen the main girder and end beam to avoid structural deformation and equipment shaking caused by long-span and long-distance operation. At the same time, the hoist lifting system is matched according to the maximum lifting height to ensure stable lifting operation and accurate positioning, taking into account the dual stability of horizontal long-distance travel and vertical lifting, and adapting to the needs of complex space operations.

Duty class

The working level represents the working load and durability level of the crane. It is strictly forbidden to use low-level equipment under long-stroke working conditions. Low-frequency, intermittent long-distance operation, you can choose A3-A4 working level. The structural strength, motor power, wear-resistant components, and electrical systems of high-level equipment have been strengthened and designed to be adapted to long-term, long-distance and high-load operations, with lower failure rates and longer service lives.

Operating environment

Different operating environments need to match the long-travel overhead crane with exclusive protection design. For ordinary indoor drying plants, you can choose the standard configuration model. Workshops with high temperature, dust, humidity, and corrosive gases need to be equipped with dust-proof, moisture-proof, and anticorrosive protection systems, motors and electrical components should be sealed, and metal structures should be anticorrosive sprayed. In outdoor and high-altitude windy scenes, sway control and wind-proof braking configurations need to be strengthened to improve the wind-resistant stability of the equipment. Targeted environmental adaptation design can avoid environmental factors exacerbating equipment loss and ensure the stable operation of long-travel overhead crane in various scenarios.

The core of the selection of long-stroke bridge cranes lies in relying on a mature double-beam upper rail structure, with frequency conversion control, intelligent sway control and optimized travel system, while doing a good job in track construction and normalized operation and maintenance, so as to resolve common problems such as track deviation, load shaking, and rapid loss of components in long-distance operations. There is no need to blindly pile up the configuration, nor can you blindly compress the budget. Customization that fits the on-site working conditions is the best idea. Henan Mine Crane Factory is deeply engaged in the manufacture of lifting equipment, relying on rich project experience to create long-stroke lifting solutions on demand, taking into account stable operation, operating efficiency and equipment life, to help the factory reduce costs and increase efficiency in the long term.