Analysis of noise source and its control

With the fast expend scale of national transportation infrastructure and urban construction, winch size is becoming bigger, power rate is more higher, and pulling speed becomes quicker.
As a result, key motive part- drum of winch is becoming bigger. Under high power rate and speed condition, the noise of winch is more loudly. However, it is not allowed for most countries, and for China, the government come out a policy GB1955—2002 file. And it rule that qualified construction winch should limit its off-line noise under 85dB(A), and noise for operator should lower than 88dB(A). Moreover, when use lower pulling power and slower speed of winch, its noise should far below standard, for it is easy to control. But, when using a high pulling power and fast speed winch, to make it attach to standard, engineer should adopts useful solutions from design, material, technology and quality testing.


For two reasons that experts think that mount may cause noise. Firstly, winch mount adopts to box type structure, not all welds are welded. Besides, every welding joint has different size and height, and steel strength has individual difference. Moreover, some mount may has resonance effect. If pulling produce little shack, then the noise will be magnified. Secondly, mount is soldered by steel plate, which has no shock absorption function. It will arose strong resonance if its inherent frequency close to gear mesh frequency because of gear weakness, and then noise rate will increase.

Bearing clearance

Some people think that as noise come out with drum and transmission part, so that the drum sliding bearing clearance may be the reason of noise. After check of drum parts clearance and ensure bearing hole and shaft clearance conform to drawing requirement, experts make a test after assembling. Experts choose a frequency conversion motor to change speed to observe how speed affects noise. According to large number test, speed has decisive influence to noise. The faster the drum spans, the more noise it made, and the winching machine shacks more strong. Bearing clearance ranges the second place to influence noise, the bigger the clearance between principle axis and axle sleeve, the stronger of noise. What is more, mount has smallest influence, if rope winch itself has little noise, and no matter speed fast or slow, the change of bearing clearance has little effect on noise. So evidence shows that noise exceed standard is not caused by bearing clearance.

Though we have many standard to a winch machine, there is still problem. There are many ways to lead to noises of a pulling winch, but noise comes from shack and shock essentially. In most situation, noises are made because that poor quality and unbalance movement produce instantaneous acceleration when operate a winching machine. Take a 80 KN fast rope winch for example, the pulling speed of its wire rope is 30m/min, and the rate of its motor is 55KW, noises is under limitation, however, noise is too loud sometimes occurred, so that little rope winch cannot pass quality test only to be failed. To this case, because that all machine in the same type adopt the same blueprint and technological process, and the most qualified, for the rest, design and technology reason should be removed.

Matters you should konw when operate a winch

Definition of a winch machine

Winch machine is a kind of small medium size lifting equipment, which lifts and pulls loads by wire rope or chain winding around drum, also call hoist winch or crane winch. According to power system, winch machine is divided into electric winch, hydraulic winch and hand winch. If classify winch based on capacity, it consists heavy duty winch and light duty winch. For modern construction, most factories adopt electric winch as their main lifting device. Winch is extensively used, for it can use alone or match other large lifting device as a part. For example, you can see it works alone to lifting loads or notice it as an accessory matching overhead crane and mine machinery in road construction. All in all, because of its easy operate, large rope capacity, easy place and move, winch machine is widely used in construction, water conservancy, forestry, mining, port to lift and pull supplies and loads.

Cautions when using winches

1. Wire rope winding on drum should be in neat rows. You are supposed to stop winch machine and rearrange it when you find the winch overlap and in inclined round. It is not allowed to touch wire by hand and feet. Wire rope should retain at least three loops, release completely is forbidden.

2. Any twist and knot is forbid, when break in a pitch is more than 10%, wire rope should be replaced.

3. Anyone is allowed to cross wire rope while operating the winching machine. Operator cannot leave winch when use it. Besides, lifting loads and hanging cage should fall into ground during rest time.

4. Driver and signal man should keep loads in sight when lifting, then, driver and signal man should cooperate tightly to obey command signal.

5. Cut off power and lower loads into ground when meet power failure during operation time.

6. During work, everyone should obey controller’s signal. Operator should suspend when meet unknown signal and possible accident. After nothing wrong, work is able to continue.

7. Operator should pull knife and low down loads when meet a sudden blackout.

8. After carrying work, operator should fall tray into ground and shut electric box.

9. It is hard to avoid the part corrosion and damage of wire rope, and operator should brush protective oil for winch rope for interval period.

10. Forbid overload.

11. Pay attention to knot, squash and arc wound and chemical media when use winch machine.

12. Not allowed to lift high temperature objects and for loads have edges and corners should add preventer plate.

13. Check wire rope regularly, and scrap wasted wire rope immediately.

Wire rope of winching machine disposal standard

1. Diameter decreased. If tear and damage of wire rope diameter is more than forty percent, it should be scrapped. And if it not exceed forty percent, operator should decrease use coefficient.

2. Surface corrosion. When cable surface corrosion is obvious to the naked eyes, it cannot be used anymore.

3. Structural damage. If the whole cable rope is broken, it should be scrapped. And for wire rope has broken wires should reduce use coefficient.

4. Overload. It is not allowed to use wire rope beyond its maximum bearing capacity.

Maintenance of  winches

Motor is the most important part of a winch machine, and at the same time, it is the most expensive units, if it is broken, the repair and change cost will be high. There are some maintenance tips for you to keep your winch machine from broken early and easily. The tips in detail is following:

1. Keep dry operate environment, and keep clean of motor surface, and avoid dust and fiber of air intake.

2. When thermal protection of motor occurs, operator should check and make sure whether trouble comes from motor itself or protection setting value is too low. Only after trouble be solved can the winch machine be put into use.

3. Operator should keep good lubrication when motor is in running process. For common motor, when it works about 5000 hours, operator should complete or replace grease. When bearing is overheat or grease is metamorphic, hydraulic power should replace grease in time. And old oil should be cleaned up when operator change grease. Besides, operator should use gasoline to wash oil sink of bearing and bearing cover. Finally, use ZL-3 lithium grease base to fill gaps between inner and outer of bearing in 1/2(for 2 level) and 2/3 (for 4,6,8 level)ring cavity.

4. When bearing is at the end of its lift, the noise and vibration of motor will be increase obviously, and when it reaches following value, bearing should be removed.

5. When remove motor, it is available to take it out from shaft position or the stretching end. If you do not need to remove fan, it is convenient to remove motor from shaft stretching end. Pay attention to stator windings and insulation when take rotor from stator.

6. Take note of the original winding form, size and number of turns, wire gauge when replacing winding. And when the data lost, you should ask it from original factory. Forbid to change the original design of winding, if not, it may cause your motor broken.

Potential accidents and safety requirements

1. If winching machine and anchor bolts did not fix well, it may lead to shift and capsize of your winch.

2. No prevent slippage of wore rope or unreliable protective device may lead wire rope separate from winch.

3. Unsecured or unfixed winch rope may cause wire rope off winch drum.

4. If winch brake is failed, it cannot locate.

5. If the end of rope drum is failed to fixed position, it may arose fracture of axis.

Installation site

1. A necessary operate tent is required for a winch, and it has to be ensured that operator is able to see commanders and loads. And buildings, scaffold and stacking materials should not has influence on operator during operation process. Besides, if operating tent is under dangerous area, the tent should accord with protective requirements.

2. Winch machine should be set in the place that has a strong foundation. And it should keep distance from dangerous area. A higher ground and solid soil place is better to bury anchor. Moreover, anchor bolt should tie tightly to winch mount, and a pile is required to prevent pulling machine from move and overturn.

3. For winch drum direction, drum should counter guild pulley center. The distance from drum to the first guild pulley should obey the following rules: for grooved drum, its drum should bigger more than 15 times of the width of the reel. And for stotless reel, it should be more than 20 tomes. All the rules aim at preventing the flange of wire rope when winch machine is working.

Requirements for winch operators

1. Winch drivers should qualified and have professional certificate. Drivers should focus on task, if find barriers, he has to clear barriers to keep good sight view. No not operated rope winch when signal is unclear.

2. Idle machine before operation to make sure that motor and breaking are under good condition. And operator should know well of daily working capacity and main task.

3. Before loads lay down to ground, operator cannot leave duty. When rest time and suspend operation, operator should lay loads and cage down to ground. After work, operator should cut off power and shut electric switch box.

4. Operator should pay attention to operate condition and wear pattern of wire rope. When loads change and to lift for the first time, operator should make a test to keep loads 0.5 meter higher the ground, only each part works well can the loads be lifted and pulled unceasingly.

5. Operator has to control decay rate when using a single drum winch machine. Too fast and slammed brake are not allowed, it has to lower slowly.

6. No spanner type switch in case of crash leading to wrong operate.

7. Wire rope should put in special conduit and paint butter regularly in case of rolling compaction to destroy strength of rope.

8. Arrange rope guider when rated pulling more than 125 KN, and reserve at least 3 to 5 circle rope on winch drum.

9. The distance between drum and outer circle wire rope should beyond at least 1.25 times of the diameter of wire rope.

10. No one is allowed to cross working winch.