Hoist Overhead Crane Safety System

A High-Performance Hoist Crane by Ellsen Bridge Crane Machinery

Hoist crane refers to the hoist lifting mechanism for the crane. Because of its simple structure, easy operation, low cost, in the machinery, chemical, light industry, railway and other industries are widely used. Due to the particularity of this crane, ground operators often have multiple functions and also have many unsafe problems in their operations, operations and command tasks.

LD type single girder electric hoist crane for sale
LD type single girder electric hoist crane for sale

In order to prevent crane accidents such as lifting, GB6067-1985 “Safety Regulations for Lifting Machinery” and other relevant national standards have required hoist crane must have safety devices, such as a limiter, end stop, buffer, safety brake and so on. These safety devices equipped with effectively improve the safety and reliability of hoist crane, but due to design, manufacturing and other defects in its own production, the current hoist crane safety precautions are not perfect, according to the daily inspection experience found gourd crane in the wrong phase phase protection, anti-broken shaft protection, to prevent the electric hoist fall protection, the buffer settings and so there are still flaws or deficiencies.

Three-phase Asynchronous Taper Brake Motor

As the gourd crane uses three-phase asynchronous taper brake motor as a power unit, and the three-phase asynchronous motor operating direction and the power supply phase sequence related to the power supply when the phase sequence changes, the motor running direction and the original running direction On the contrary, at this time press the “down” button, the spreader rises, and rose to the limit position limiter does not work, likely to cause accidents. Such cranes happen each year due to misplaced roll crushing, hook group squeeze deformation, broken wire rope accident. At present, China’s production and widespread use of CD, MD-type electric hoist did not take the wrong phase-off protection (electric hoist does not require the installation). In order to prevent the wrong phase caused by the occurrence of serious injuries, in the gourd crane electrical control system to add the wrong phase protection device.

1 ton crane with electric hoist for sale
1 ton crane with electric hoist for sale

When the power supply phase failure or wrong phase, the wrong phase protectors work, the total power contactor disconnected, the power must be restored to normal after the crane can continue to work. This will not only prevent the power supply caused by the wrong roll crushing but also prevent motor phase loss of burning. Therefore, the wrong phase-phase protectors’ role is necessary.

Top Quality Configured Electric Hoist

Electric hoist in operation, due to the wheel rim and wheel tread wear, the gap between the wheel and the rail gradually increased, this time if you can not adjust the operating gap in time, the electric hoist may be off the track, causing a heavy injury accident; the same time Due to the particularity of wheel axle assembly, it is not easy to find the cracks on the axle. Cracks cannot be effectively controlled. The axle may break and cause a crash accident. In order to prevent the electric hoist caused by the fall of the accident occurred in the electric hoist additional anti-breaking shaft, derailment protection device. When the electric hoist derailment or broken shaft, the anti-off axis, derailment protection device can be effectively suspended on the track, thus avoiding the occurrence of lifting injury.

Strictly Meet National and International Standard

According to GB6o67-1985 (Crane Safety Regulations, the provisions of the operation of the electric hoist terminal must be added to the buffer.Because the installation location of the device is not clearly defined, the current domestic use of electric hoist buffer is generally installed in the work When the electric hoist running wheel and the buffer collide, the buffer has played a role in absorbing energy, but due to the particularity of electric hoist structure, running the flange of the suspension wheel and the buffer collision, the inertia The role of the suspension wheel flange so that the buffer wear is extremely serious.

When the electric hoist is running for a period of time, the damper loses its original design function so that the safety factor of the electric hoist increases and the stability of the electric hoist declines drastically. In order to prevent the occurrence of this failure, the buffer can be installed at the location of the lower surface of the I-beam, the use of buffer and electric hoist suspension play a role in the buffer collision, improve safety and reliability, to extend the life of the buffer. Any detailed information about the hoist crane, welcome contact us with your detailed inquiry.

Crane Structure Composition

The three in one operation mechanism is driven separately

In this post, Ellsen overhead bridge crane factory provides some knowledge of crane structures for your reference. The transmission system that can make the crane take some action is referred to as the crane’s mechanism.Due to the needs of lifting and transportation operations, cranes need to move up, down, move, rotate, change, climb and telescope and other actions, and these actions must be completed by the appropriate agencies.

The basic structure of the crane lifting, running, turning and luffing.In addition, tower cranes tower crawler body and cars, tires and other crane-specific telescopic retractable legs.
Each of the cranes consists of four mechanisms, namely a drive, a brake, a transmission and a dedicated device that is directly related to the functioning of the mechanism.
Drives are manpower, mechanical and hydraulic drives.The brake device is a brake.Different types of cranes use a variety of different types of brakes, such as block, disc, band, internal shoe, and cone.

Lifting Mechanism of the Crane

The driving mechanism of the lifting mechanism adopts electric drive as the electric motor.Among them, gourd crane multi-purpose asynchronous squirrel-cage motor, other electric cranes and more use of wound induction motor, or DC motor.The track, rail crane lifting drive is for the internal combustion engine.Car, tire crane lifting mechanism drive is driven by the prime mover hydraulic pump, hydraulic cylinder or hydraulic motor.The lifting mechanism is shown in Figure 1.In the picture, the take-up winding device includes a lifting reel (or sprocket), a wire rope (or a chain), a fixed pulley, a movable pulley, a hook (or a grab, a ring, a crane beam, an electromagnetic chuck)

Cane Hoisting Structure
Cane Hoisting Structure

1.Electric motor 2. Brake  2.Reducer 4. material taking and winding device

Crane operating mechanism

Crane operating mechanism can be divided into the rail-type operating mechanism and non-rail-type operating mechanism (tire, track-type operating mechanism), where only rail-type operating mechanism introduced.Rail-line operating mechanism in addition to railway cranes is basically a motor-driven form, as shown in picture 2.This operating mechanism is composed of motor 7, brake 8, reducer 5 and the wheel 1,2 four parts.
Wheel device is composed of the wheel, wheel shaft, bearings and bearing boxes and other components.

The use of rimless wheels is to change the sliding friction of the rim into rolling friction, at which time a horizontal guide wheel should be added.Wheel and wheel shaft connection can be a single key, spline or cone sleeve and other means. Crane operating agencies are divided into centralized drive and drive two kinds of forms.

The centralized drive is a motor driven by the drive shaft on both sides of the wheel running in the form of running agencies, as shown in Figure 2.Centralized drive only suitable for a small-span crane or crane operating mechanism.

Crane Drive Structure
Crane Drive Structure

1.sub-wheel 2. main-wheel 3. coupling 4. transmission shaft 5.reducer 6. full gear coupling 7. motor 8.brake 9. open-gear 10. bear 11. coupling 12. compensating shaft 13. braking-wheel coupling

The separate drive is on both sides of the wheel by 2 sets of the independent mechanical drive mechanism in the form of links, as shown in Picture 3.

The operating mechanism that is driven separately
The operating mechanism that is driven separately

1. Motor 2. Brake 3. Gear reducer 4. Wheel unit

With the development of hoist crane technology, the motor uses tapered brake motor, the two functions of drive and brake combined, and further developed into the motor, brake and reducer combined into one, no longer need to link The shafts are connected to form a very compact unit, known as a conical brake motor, which has now been applied to cranes and carts as shown in Picture 4.

The three in one operation mechanism is driven separately
The three in one operation mechanism is driven separately

1. “Three in one” drive 2. Wheel device

Any detailed information you need about the crane, welcome contact us.

Overhead Crane Hook Technology

Ellsen Crane Hook

Optimization design of overhead crane hook based on ANSYS

Ellsen double girder overhead hook crane is one of a hot sale overhead bridge crane warmly recognized by our clients as its low-cost price and high working performance. Here below in this post at our official overhead crane blog, the Company will introduce some key technologies it has employed on its crane hook products.

The bridge crane hook is the most widely used device and the main bearing part of the lifting equipment. The strength of the hook and the rationality of its design are very important to the safety of the crane.Therefore, the modern finite element analysis method is used to analyze the strength of the hook to find the maximum deformation position of the hook, reveal its stress distribution law and dangerous section, and provide a theoretical basis for the research and design of the hook strength, which has important engineering significance.

Ellsen Crane Forged Hook
Ellsen Crane Forged Hook

According to the actual working condition, the restraint and load of the crane hook are treated effectively, and the strength of the overhead bridge crane is analyzed by finite element method. The distribution law of the stress and displacement of the hook is obtained, and the dangerous section of the hook is revealed.On the basis of the finite element analysis, the thickness of the hook is optimized under the premise of ensuring the safety of the hook, and the results are compared before and after optimization.After the optimization, the size of the crane hook is more reasonable, and the weight of the hook is reduced.The analysis and optimization results provide a scientific and reasonable basis for the structural design of crane hook.

Establishment and analysis of finite element model

The structure and parameters of the hook are taken as an example of the main lifting straight hook of the 50t/10t bridge crane of a working grade M5 in the actual production, and its structural form is illustrated as shown.The parameters are as follows: single hook, hook number 40, strength grade is M, the maximum thickness of the hook body horizontal section is 200mm, the maximum thickness of the vertical section of the 170mm 150mm. hook shank diameter, the material is DG20Mn, the yield point of the material is 333MPa, tensile strength 510MPa, elastic modulus and Poisson’s ratio of 0.3, E=2.1ellPa, density 7860kg/m3. hook maximum allowable bending stress: hook straight rod part maximum allowable tensile stress: simple structure without a hook.

Ellsen Crane Hook
Ellsen Crane Hook

 

The finite element model of the hook is established. The geometric characteristics of some transition angles have little influence on the strength. In the Ansys, the generation probability of the distorted mesh will be increased, the calculation time will be increased, and the calculation accuracy will be affected. Therefore, the modeling should be simplified.The element type chooses the hexahedron structure element Solidl85., the upper part of the hook straight handle is added to the constraint, and the whole degree of freedom is restrained.

Because of the actual process of hoisting, lifting will swing, the tension of rope hanging and vertical direction have a certain angle, according to the engineering practice and floating rules, this angle should be controlled at about 30 degrees.Therefore, when the hook load reaches the maximum lifting weight of 50t, and the tension angle of the rope is 30 degrees, the hook is at the most unfavorable load limit condition.

The diameter of the cable for hanging heavy object is D=28mm, that is, the load acting section is about D and the maximum thickness of the middle vertical section of the hook.The load acting on the hook of the suspended cargo rope is simulated by applying the uniformly distributed load on the surface of the 30 sides of the middle vertical plane of the hook.

Mesh generation, adding constraints and applying surface loads are obtained.

The maximum stress of the hook occurs on the inside of the main bending section of the hook (horizontal section), and the maximum stress is 157MPa. The maximum stress of the main bending section (horizontal section) of hook body is about 87MPa, which is less than the allowable stress 214.84MPa.

Hook hook body in the vertical section of the internal stress is larger, as another dangerous section, the maximum stress is about 104MPa.

Ellsen Crane Hook Technology
Ellsen Crane Hook Technology

The maximum tensile stress of the straight bar of the hook is 69.6MPa, less than the allowable stress 102MPa., so the actual analysis of the stress value is far less than the yield limit of the material, the stress margin is large, indicating that the hook is very safe and can be optimized.

The hook on the hook load optimization force and safety factor requirements are met, the maximum thickness can be reduced and the hook straight shank diameter to optimize the structure and size, the maximum thickness of the horizontal section is reduced from 200mm to 180mm, the maximum thickness of the vertical section is decreased from 170mm to 155mm, shank diameter decreased from 150mm to load 135mm. then applied approximately: the optimized hook remodeling, the constraint remains unchanged, the finite element analysis is carried out again.

Any needs of our hook crane products, please be free to contact us.

 

Electromagnetic Crane Technology

40t Electromagnetic crane with carrier beam for sale

Electromagnetic crane is a kind of heavy duty crane, manufactured from Ellsen Overhead Bridge Crane Factory, right here below, the company introduces some key technologies that have been employed in our overhead crane system. Any questions, our crane engineer experts are ready to reply to you as soon as possible. The following includes two parts, the first part is the overhead cranes’ magnetic sucker technology introduction, and the second part is the overhead cranes’ control system technology introduction.

Electromagnetic 10t double girder crane for sale
Electromagnetic 10t double girder crane for sale


Two categories and uses of magnetic chucks that you don’t know

The two categories and uses of magnetic chucks are the factors that must be taken into consideration when purchasing electromagnetic cranes.Ellsen lifting machinery here tells you two categories and uses of magnetic sucker: Magnetic sucker family has automatic magnetic chuck and manual magnetic chuck.

Automatic magnetic chuck is usually used when lifting steel plate and can be freely assembled according to the size of steel plate.The automatic magnetic chuck has the advantages of light structure, convenient operation, strong holding power, no power consumption, safety and reliability, etc..Magnetic chuck helps to improve the working conditions of material conveying operation and improve labor productivity.Therefore, as a kind of efficient, safe, energy-saving new magnetic sling, it has been widely used in shipbuilding, construction machinery and mold manufacturing and other industries.The use of permanent magnet lifting operation does not need an external power supply and electric control parts, the operation is simple and convenient, safe and reliable use, automatically sucking and discharging action.The permanent magnet can be associated with trolleys, cranes and other equipment, which can be used in the single machine, and multiple suction steel billet or another type of steel, durable, easy maintenance, and is an ideal energy saving magnetic suspension.

Manual magnetic sucker is normally used in lifting the workpiece. It is often for the single user, and can also be used in combination with other lifting equipment. The manual permanent magnet lifter has the advantages of small volume, so it has a higher requirement on the thickness of the steel plate.

Application of wireless communication technology in crane linkage control

QC electromagnetic crane for sale
QC electromagnetic crane for sale


Through in-depth study of wireless communication technology, in the multi crane linkage control, Ellsen Crane Machinery adopts wireless communication technology.Our company produced 4 cranes for a steel plant, 4 cranes need linkage control, lifting several fixed length objects together, and sometimes need 2 cranes linkage control, and sometimes need 3 cranes linkage control, and sometimes need 4 cranes linkage control.

Overhead crane drawing design

The crane inverter drive and PLC control between PLC and inverter using Profibus-DP communication between a crane and a crane with a wireless communication module for data exchange, using the encoder as the feedback signal, feedback mechanism of each operation distance of each crane, to achieve the purpose of the synchronous running of the multi crane.

QC 20T Electromagnetic Bridge Crane with Magnet
QC 20T Electromagnetic Bridge Crane with Magnet


  •  Lifting mechanism inverter using SIEMENS’s S120 series, operating agencies, frequency converter using internationally renowned lifting accessories brand.
  •  PLC uses SIEMENS’s S7-300 series, with Ethernet communication module.
  • The wireless communication module uses SIEMENS’s W788 series.
  •  The encoder uses P+F absolute encoder with Profibus-DP communication port.
  • Overhead crane design drawings include active control switch, single control switch,  linkage control switch and wing control switches can control the other 3 cars; the crane machine start button, a stop button, bell switch, lighting switch and various institutions switches.
  • The buttons and switches of the machine are used to control the operation and stop of the machine, that is, the single crane.
  • Active control switch and driven control switch are interlocked.
  • The active control switch is used for the crane to call the car and send control commands to the vehicle.
  • The slave control switch is used for the crane to do the slave car and receive the control command of the main vehicle.
  • Single action control switch and linkage control switch interlock each other,
  • The single action control switch is used to control the individual work of the machine,
  • The linkage control switch is used to control the linkage and work with other cranes.

 single action control switches are installed on the machine used separately to operate the other 3 cranes on the machine.

Programming

configure the hardware of PLC control system: the control system uses SIEMENS STEP7 programming software on the hardware configuration, opens the STEP7 programming software, inserts 300PLC rail, power supply, CPU, Ethernet module, input, and output module, SIEMENS inverter S120 hardware, Yaskawa inverter A1000 hardware, P+F hardware, to save and compile the crane hardware .In this project, the PLC used in the other 3 cars is inserted separately, and the PLC used for each car is saved and compiled respectively.In the configuration network, the 4 PLC constitute the ISO-on-TCP connection network to save and compile the machine configuration.So the hardware configuration is completed.

Compile the communication control program of the machine

This machine communication control program using SIEMENS SFC14 programming software and SFC15 function block, read and write operations on the hardware configuration of S120 inverter; inverter with STARTER software, the communication message using standard message mechanism; the start command, stop and speed command with the given command control and status word S120 converter, and to monitor the state of the word, to realize the protection function; the start command, stop and speed command with the given command control and status word Yaskawa inverter, and to monitor the state of the word, to realize the protection function.

Programming communication control program between 4 sets of PLC

In the STEP7 programming software call FC5 and FC6 function block, through the function block of 4 cranes PLC between sending and receiving data programming.The data of one trolley is sent to another 3 cranes respectively, and the data of 3 other cranes are also received. The data include control commands, speed commands and the distance of each mechanism.

 Compile the synchronous control program for each crane of 4 cranes

Using the calculated encoder running distance to various agencies, institutions of a crane running distance as a benchmark, the distance and the reference distance in the other 3 agencies crane operation were compared, if the distance is larger than the reference distance and shows the running speed of the crane of the agency quickly, the operation speed is reduced, given the inverter speed value is small, otherwise, given the speed value, to ensure the synchronization of each mechanism of multi crane.

linkage control program

According to the PLC data transmission, the linkage control switch and single control switch, in the preparation of the control procedures, if the linkage control switch point is closed, the crane in the state; if the single point control switch is closed, the crane work alone, without any control of a crane.Active control switch and the driven control switch plays a role in the linkage control switches closed, the active control switch and the driven control switch, in the preparation of the control program, active control switch point is closed, the crane for active crane can be controlled by the moving crane; closing driven control switch. The crane is driven only by active control of crane, crane, from the train master operation does not work; in the linkage condition, through the operation of the other 3 crane single switch, can control any one of the 1 cranes working alone.

Programming communication interruption program

The clock memory in the cycle/clock memory with the CPU attribute has different scanning periods in each byte of the clock memory, and the timing programming is carried out according to its scanning period.If the wireless communication is interrupted, the clock scanning cycle of CPU will be interrupted, then the timer will be switched on, so as to ensure the normal operation of the interrupt program.

Crane Debugging

Hardware Debugging

According to the characteristics of Profibus-DP communication, according to the hardware configuration, set the DP address of each frequency, set the encoder address, then according to the software, using the online function, whether each from the station are in the online state, put each site hanging in the Profibus-DP communication line.

 Frequency converter debugging

First of all, the lifting mechanism of the inverter debugging, the use of STARTER software to debug the inverter, the motor self selective learning, set its control mode for PG loss control.Then the frequency converter of the operating mechanism is debugged, and the control mode is set as PG voltage frequency control mode.Finally, the direction of the motor controlled by the inverter is debugged, and the direction of the motor is consistent with the control direction of the main command.

Software debugging

W788 configuration for wireless communication module: according to the configuration of PLC network, W788 configuration and PLC configuration in the same network segment, only in this way, can exchange data between 4 PLC.

Debugging the program

According to the pulse number of absolute encoder rotation, the number of pulses corresponding to the unit distance is calculated. According to the distance of each mechanism of the crane, the speed is adjusted, and the size of the given speed value is adjusted.At the same time, the communication interrupt protection program should be debugged so as to make the crane stop completely after the wireless communication interruption, and prevent the occurrence of the safety accident.

Through the electrical control design and debugging of 4 cranes, wireless communication can meet the needs of synchronous crane control, and in the case of wireless communication failure, crane safety parking requirements.It is feasible to run the wireless communication module on the special equipment of the crane.

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Crane Structure Design Technology Breakthrough

Ellsen 25ton double girder overhead crane for sale

After several decades of development, Crane Structural optimization technology becomes more and more natural, and its good economic performance, in the field of machinery has been widely used. As a large-scale construction machinery, gantry crane can be used to optimize the structure of its metal structure to achieve the purpose of the lightweight structure. At present, many crane enterprises and some colleges and universities such as Southwest Jiaotong University, Dalian University of Technology, Zhengzhou University and other universities are making cooperation on the optimization of the metal structure of the crane and have done a lot of research.

Ellsen 25ton double girder overhead crane for sale
Ellsen 25ton double girder overhead crane for sale

Research on Structural Optimization of Cranes

Structural optimization of gantry crane

Taking the L-type gantry crane as an example, the performance index of the mast is programmed into the program, which is optimized with I SIGHT. The multi-island genetic algorithm is used to optimize the mast. Then, based on the finite element method, the optimal design of the gantry is carried out. The advantages and disadvantages of the two optimization schemes are analyzed by comparing the two optimization results. Fan Li Ge combined with the sensitivity analysis technique and the structural optimization design, the parameters with great influence on the total volume of the metal structure of the gantry crane are selected as the design variables, and the optimal design of the structure is completed. Tang Hui firstly took the main gantry as the mast for cross-section optimization, followed by a non-symmetrical outrigger structure to achieve the weight of the crane design. CUI Hua-wei took VB as the development platform, the gantry structure model was established by using APDL language. Based on the static analysis, the maximum equivalent stress and the cantilever deflection were used as the state variables to optimize the gantry structure. On the basis of static analysis of gantry crane, Wang Zhixin has optimized the structure of crane main girder. Chen Guanshun introduced the dynamic displacement as the constraint condition to optimize the design of the gantry crane structure, thus reducing the weight of the gantry crane. Summer aluminum using a genetic algorithm for the gantry crane main beam was optimized design, the crane weight reduced by 11.4%. The structure of the cantilever beam of the gantry crane is optimized by the combination of genetic algorithm and structural optimization technology. Qi Qisong has optimized the main girder structure with some cross-sectional dimensions of the main girder of the gantry crane as the design variable. Sun cave looked at the lower beam of the crane. In the ANSYS, the simplified finite element model of the main girder of the crane is established, and the weight of the main beam is reduced by 18%, and the weight of the main beam is reduced by 18%.

Ellsen overhead crane 5 ton for sale
Ellsen overhead crane 5 ton for sale

Structure Optimization of Overhead Bridge Crane

ZHANG Xiao-li (School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China) used the application of multi-objective genetic algorithm in engineering, and the genetic target optimization algorithm based on Pareto ranking is developed. The topological optimization of the main beam was carried out by means of ANSYS software, and the topological optimization model of the initial concept of the main girder was obtained. Cheng Lizhu uses ANSYS software to use the main beam height, width, the thickness of the upper cover plate, the thickness of the lower cover plate and the thickness of the left and right webs as the design variables. The vertical deflection and equivalent stress of the main girder are the state variables, and the total mass of the main beam is the lightest as the objective function, the main beam size optimization, optimized weight reduction of 29%, the effect is more obvious. Meng Wenjun uses ANSYS software to model the main girder and end girder of the crane. The LHS of Mote-Carlo is used to analyze the sensitivity of the crane’s metal system, and the structural parameters with great influence on the bridge are found. Under the premise of ensuring the reliability, the dimensions are optimized. The total weight of the crane reduces to 7.3t. The model of the gantry crane is established in ANSYS, and the effect is optimized. Better than the previous weight reduction of 18.9%, Naresh Chauhan analyzes the stress and strain of the overhead traveling crane. Zhao Qiong established an optimization design model with the key parameters as design variables and proposed an optimization method based on genetic algorithm and finite element analysis. By optimizing the four-bar luffing mechanism, the production cost of a gantry crane and operating costs. Fan chaos theory is introduced into the optimization design of CMS, which saves the computation time and improves the computational efficiency compared with the previous ant colony optimization algorithm. Fan, Xiaoning The sensitivity analysis of the uncertain variables of the bridge crane is carried out. The optimal design model of the overhead bridge crane based on reliability is constructed. Under the premise of satisfying the working performance, the design structure is compared with the traditional design phase, and the weight of the crane is much reduced. Kim and so on the crane boom support structure to establish a three-dimensional model, the use of HyperWorks software to its topology optimization.

Single Girder eot crane design
Single Girder eot crane design

Ellsen always decade itself in most advanced crane technology for providing best excellent crane products for the worldwide customers. With the above research theories’ support, Ellsen Crane Machinery can manufacturer different kinds of cranes, featuring in smart, light duty and high-performance structure, which can easily promote your working efficiency to a large degree.