Winches are light and small lifting equipment that use drums to wind steel wire ropes or chains to lift or pull heavy objects, also known as winches.The winch can vertically lift, horizontally or obliquely pull the weight.The winch is divided into manual winchElectric hoistAnd hydraulic winch.Mainly electric hoist.It can be used alone or as a component of hoisting, road building, mine hoisting and other machinery. It is widely used because of its simple operation, large amount of rope winding and convenient displacement.It is mainly used for lifting or towing materials in buildings, water conservancy projects, forestry, mines, docks, etc.
The main products are: JM electric controlled slow speed large tonnage winch, JM electric controlled slow speed winch, JKElectric control high-speed winchJKL manual controlled quick release winch, 2JKL manual controlled double quick release winch, electric and manual controlled dual-use winch, JT speed regulating winch, KDJ mini winch, etc. can only be used on the ground and can be modified to be used on board.It is powered by motor, driven by elastic coupling, three-stage closed gear reducer, tooth embedded coupling, and adoptsElectromagnetic braking。This product has high versatility, compact structure, small size, light weight, heavy lifting, convenient use and transfer, and is widely used in construction, water conservancy, forestry, miningwharfIt can also be used as auxiliary equipment for modern electric control automatic operation line.JM series isGear reducerDrive the winch.It is applicable to civil construction and installation works of construction and installation companies, mining areas and factories.
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A device that is driven by human or mechanical power to complete the traction work by the drum and winding rope.
Coaxial winch: (also called mini winch) The motor and wire rope are on the same transmission shaft, which is light and compact and saves space (its tonnage includes 200kg, 250kg, 300kg, 500kg, 750kg, 1000kg, etc.).
Slow speed winch: winch with the rated speed of wire rope on the drum about 7~12m/min.
Fast winch: winch with the rated speed of wire rope on the drum of about 30m/min.
Speed regulating winch: winch with adjustable speed control.
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Hand winch: a winch driven by human power, which rotates the drum through the driving device.
Large tonnageNon standard winch: Mainly used for hoisting, pulling, unloading, pushing and dragging heavy objects.Such as the installation and removal of various large and medium-sized concrete, steel structures and mechanical equipment.Its structural characteristics are orderly arrangement of steel wire ropes, reliable installation with cranes, and suitable for road and bridge projects such as docks, bridges, ports, and installation equipment in large factories and mines. It is a kind of equipment that uses external forces (such as motors) to drive its operation, and then uses electromagneticBrakeAnd a locking brake to control its free operation without power. At the same time, after being driven and decelerated by the motor, it drives a wheel disc to run, on which steel cables or other things can be wound.
Winches that lift more than 30 tons are usually large tonnage ones. There are only a few technologies to produce large tonnage ones in China, and the maximum tonnage is 65 tons.Mainly subdivided into JK (fast), JM, JMW (slow), JT (speed regulation), JKL, 2JKL manual controlled fast and other series of winches, widely used in industrial and mining, metallurgy, lifting, construction, chemical industryRoad and bridge、hydropowerInstallation and other lifting industries.
4. JML5, JML6, JML10 slide type pile driving winch
5. 2JK2-2JML10 double drum winch
6. JT800, JT700 explosion-proof hoist
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7. JK0.3-JK15 electric control winch
8. Non standard winch
Where JK refers to fast winch and JM refers toSlow speed winch, JT refers to explosion-proof winch, and single drum refers to the capacity of one druma wire rope, double drum means that two drums hold the wire rope.
The pneumatic winch isAir compressorThe compressed gas provided is a kind of winch with power source. Compared with the traditional electric winch, the pneumatic winch has the characteristics of explosion-proof, dust-proof and liquid splash prevention, and is more suitable for working in harsh environments. Therefore, the pneumatic winch is widely used in ships, oil exploitation, mining, power and other industries.
The pneumatic winch is composed ofPneumatic motor, reducer, brake, clutch, drum, overload protection device, control valve, etc. The traction force is 200kg, 500kg, 1T, 2T, 3T and 5T, and the traction length can reach 350m.
Precautions
To ensure the safety of use,Pneumatic winchThe breaking force of the steel wire rope is generally about 5 times of the load bearing, that is to say, if the load is 10KN, the breaking force of the steel wire rope must be at least 50KN to ensure the safety of operation.In addition, pneumatic 3 elements need to be installed when using（Air filter, air oiler, air pressure regulator), the air oiler must be installed in front of the air inlet of the engine body.
structural style
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Winch structure
The winch converts electrical energy into mechanical energy through motor 1, that is, the rotor of the motor rotates and outputs, and drives drum 6 to rotate after decelerating through V-belt 2, shaft 3, gear 4 and 5.The drum winds the steel wire rope 7 and passes the pulley blocks 8 and 9 to make the crane hook 10 lift or drop the load Q, convert the mechanical energy into mechanical work, and complete the vertical transportation and loading and unloading of the load.
The rope groove participating in the bearing can change the stress distribution law of the drum and reduce the stress of the drum wall.[1]
Design reference standards
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National reference standards for construction winch:
GB1102 Round Strand Wire Rope
GB3811 Code for Design of Cranes
GB5972 Code of Practice for Inspection and Scrapping of Steel Wire Ropes for Hoisting Machinery
GB6947 Test code and method for construction winch
GBJ232 Code for Construction and Acceptance of Electrical Equipment Installation Engineering
JJ12.3 General Technical Conditions for Weldments of Construction Machinery
JJ15 General Technical Conditions for Assembly of Construction Machinery
matters needing attention
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1、 When the winch is usedmatters needing attention：
1. The steel wire ropes on the drum shall be arranged neatly. If overlapping and oblique winding are found, the machine shall be stopped and rearranged.It is strictly prohibited to use hands or feet to pull or step on during rotationa wire rope。The steel wire rope shall not be completely released, and at least three circles shall be reserved.
2. The wire rope shall not be knotted or twisted, and shall be replaced when the broken wire exceeds 10% within one pitch.
3. During the operation, no one is allowed to cross the wire rope. After the object (object) is lifted, the operator is not allowed to leave the winch.During rest, objects or cages shall be lowered to the ground.
4. During operation, the driver and signalman shall keep good visibility with the hoisted object, and the driver and signalman shall closely cooperate and obey the unified command of the signal.
5. In case of power failure during operation, cut off the power supply and lower the lifted object to the ground.
6. Follow the signal of the commander during work. The signal is unknown or may cause accidents
The operation shall be suspended until the situation is clear.
7. In case of sudden power failure during operation, the knife switch shall be opened immediately to put down the transport.
8. After the operation is completed, the material tray shall be landed and the electric box shall be locked.
9. Wear of steel wire rope and machinery during use. Local damage due to spontaneous combustion corrosion is inevitable, and it should be painted at intervalsProtective oil。
10. Overload is strictly prohibited.That is, the maximum bearing tonnage is exceeded.
11. Be careful not to knot, flatten, arc damage or chemical medium erosion during use.
12. It is not allowed to directly lift high-temperature objects. For objects with edges and corners, guard boards shall be added.
13. During use, the steel wire rope used shall be checked frequently, and it shall be scrapped immediately if it reaches the scrapping standard.
If the diameter wear exceeds 40%, it shall be scrapped, and if it does not exceed 40%, the coefficient shall be reduced for use.
2. Surface corrosion;
When the surface corrosion of the whole wire rope is obvious to the naked eye, the wire rope cannot be used.
3. Structural failure;
The whole strand of wire rope shall be scrapped, and the wire rope with broken wire shall be used with reduced coefficient.
4. Overload;
Wire ropes used for overload shall not be used.
noise control
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countryTransport infrastructureWith the increasing scale of urban construction, the size and power of the winch used in construction projects are increasing, and the traction speed is also increasing. Accordingly, the size of the drum open gear pair structure, the key transmission part of the winch, is getting larger and larger, and the noise of the winch is getting higher and higher under the condition of high-power and high-speed operation. However, this is not allowed by the national standards.The noise limit of qualified winches specified in the national standard for construction winches GB1955-2002 is not more than 85dB (A) outside the machine, and not more than 88dB (A) at the operator's ear.When the winch has small traction and low speed, its noise is far below the standard limit, and it is easy to control;However, when the traction speed is high and the traction force is large, the noise shall not exceed the standard, and effective measures shall be taken from design, process, materials, quality inspection and other aspects.1 Existing problems: The noise of the winch comes from many sources, but it is essentially the result of impact and vibration, generally due to poor meshing quality of gears and unstable movementInstantaneous accelerationCaused by.We have an 80kN fast slip hydraulic control winch. The wire rope traction speed is 30m/min, and the motor power is 55kW. The machine noise is generally within the standard range, but occasionally the noise exceeds the standard. A few machines cannot pass the factory inspection.When removing the noise, I feel that I have no way to start. Since the drawings and process flow on which the machine manufacturing is based are the same, since most products are qualified, the unreasonable factors of design and process should be eliminated.
Noise source analysis and control
1. Chassis We think that the chassis design and manufacturing may cause noise: ① The chassis adopts a box structure, and not all welds are continuously welded. The length and height of each chassis weld are different, and there are large individual differences in chassis rigidity. Some of them have resonance effects, and the vibration noise of the machine will be amplified if there is a little vibration; ②The chassis is welded by steel plate, which does not have the function of shock absorption and noise elimination. If its natural frequency is close to the gear meshing frequency, it may cause large co vibration of individual machines due to weak and small gear vibration, causing the noise value to rise.We tested the above possibilities separately, but through three experiments, we found that the noise level was weakly related to chassis structure, stiffness, frequency and other factors, and the noise level was strongly related to moving parts. Therefore, the chassis design structure and manufacturing quality were not the cause of excessive noise.
2. Some people think that since the noise is accompanied by the drum assembly and transmission parts, it may be caused by the drumsliding bearingIt is caused by large clearance.We select the fitting clearance of the drum parts to ensure that the clearance between the bearing hole and the main shaft meets the requirements of the drawing. After assembly, the test is carried out.Used in the testVariable frequency motorSpeed regulation, observe the impact of speed on noise.A large number of test results show that speed has the first influence on noise. The higher the drum speed is, the greater the noise value and the more intense the machine vibration will be;Secondly, the greater the clearance between the main shaft and the shaft sleeve, the greater the noise;The chassis has the least impact on noise.If the noise of the machine is low, the changes in speed and spindle clearance will not produce excessive noise, which indicates that the excessive noise is not caused by the large bearing clearance.
Maintenance
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In the design process of the winch, it is necessary to avoid wire rope disorder, rope biting and other phenomena. A winch with a cam rope guiding mechanism is proposed. The drum is the key design component, and the traditional design method mostly determines its thickness by experience.[2]
The motor is an important part of the winch, and also the most expensive part of the winch. If it is damaged, the cost of repair or replacement will be very high.So remind customers here to maintain the winch orWinchMotor.Maintenance methods are as follows:
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1. The operating environment should always be kept dry, the motor surface should be kept clean, and the air inlet should not be hindered by dust, fiber, etc.
2. When the thermal protection of the motor acts continuously, it is necessary to find out whether the fault is from the motor or overload or the setting value of the protection device is too low, and then it can be put into operation after the fault is eliminated.
3. The motor shall be well lubricated during operation.Generally, the lubricating grease should be supplemented or replaced after the motor runs for about 5000 hours. If the bearing is overheated or the lubrication deteriorates during operation, the hydraulic system should replace the lubricating grease in time.When replacing the lubricating grease, the old lubricating oil shall be removed, and the oil groove of the bearing and bearing cover shall be cleaned with gasoline, and then ZL-3 lithium based grease shall be filled into 1/2 (for 2 poles) and 2/3 (for 4, 6, and 8 poles) of the cavity between the inner and outer rings of the bearing.
4. When the service life of the bearing ends, the vibration and noise of the motor will increase significantly. When the radial clearance of the bearing reaches the following value, the bearing shall be replaced.
5. When disassembling the motor, the rotor can be taken out from the shaft extension end or non extension end.If it is unnecessary to remove the fan, it is more convenient to take out the rotor from the non shaft extension end. When taking out the rotor from the stator, it should prevent damage to the stator winding or insulation.
6. When replacing the winding, the form, size, turns, wire gauge, etc. of the original winding must be recorded. When these data are lost, they should be obtained from the manufacturer. Changing the original design winding at will often worsen the performance of one or more items of the motor, or even make it unusable.
Potential accident
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The winch has the advantages of large bearing capacity, stable and reliable hoisting and wide range of operating speed, and is widely used. However, due to the lack of awareness and effective methods of safe use of the winch, production accidents are often caused.[3]
one
The winch is not firmly fixed and the ground anchor is not firmly set, resulting in displacement and overturning of the winch.
two
There is no protective device on the drum to prevent the wire rope from slipping, or the protective device is set unreasonably and reliably, which causes the wire rope to leave the winch.
three
The end of the wire rope is not fixed or does not meet the requirements, resulting in the wire rope falling off.
four
The winch actuator is out of order and cannot be positioned.
five
Inaccurate positioning of rope drum shaft end causes shaft fatigue fracture.
safety requirements
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Installation position
1. Set up the operation shed and ensure that the operators can see the commander and the dragged or lifted objects clearly.Buildings, scaffolds, materials and components stacked on site during construction shall not affect the driver's monitoring of the whole process within the operating range.The top of the operation shed in the dangerous operation area shall meet the requirements of the protective shed.
2. The foundation is firm.The winch shall be far away from the dangerous operation area as far as possible, and the place with high terrain and solid soil shall be selected. The buried anchor shall be locked with steel wire rope and the winch base. Piles shall be driven in front to prevent the winch from moving and overturning.
3. Drum direction.The drum is aligned with the center of the guide pulley, and the distance from the drum to the first guide pulley is as follows: the grooved drum shall be 15 times larger than the drum width, and the grooved drum shall be 20 times larger than the drum width, so as to prevent the steel wire ropes from overlapping each other and the guide pulley flange and steel wire rope from wearing when the drum is running.
Requirements for operators
1. The winch driver shall be trained professionally and work with certificate. He shall concentrate during operation. If he finds any obstacle in his sight, he shall remove it in time. If the signal is unclear, he shall not operate.
2. Idling shall be carried out before operation to confirm that the electrical, braking and environmental conditions are in good condition before operation. The operator shall understand the main content and workload of the work on duty in detail.
3. The driver shall not leave the post when the lifted object does not fall completely on the ground.When resting or suspending operations, objects or lifting cages must be lowered to the ground.After work, cut off the power supply and close the switch box.
4. The driver shall pay attention to the operating conditions and the wear of wire rope at any time.When the load changes for the first time, stop for 0.5m above the ground, and continue to rise when there is no problem.
5. When using a single drum winch, the lowering speed must be controlled by the brake, and the winch must fall slowly instead of braking too fast or sharply.
6. It is forbidden to use toggle switches to prevent collision and misoperation.
7. The steel wire rope shall be regularly smeared with grease and placed in a special groove to prevent rolling and damaging the strength of the steel wire rope.
8. When the rated tension of the winch is greater than 125KN, a rope guide shall be set. At least 3~5 circles of wire rope shall be reserved on the drum, and the end of wire rope shall be fixed reliably.
9. The distance from the outer edge of the drum to the outermost wire rope shall not be less than 1.5 times the diameter of the wire rope
10. During operation, no one is allowed to cross the winch wire rope under operation.
