Lubrication and Maintenance Guide for Wire Rope Electric Hoists

Lubrication and Maintenance Guide for Wire Rope Electric Hoists
In many fields such as industrial production and construction, wire rope electric hoists, as common lifting equipment, play a vital role. With its efficient lifting performance and convenient operation, it can help workers easily complete the lifting task of heavy objects. However, in order to ensure that the wire rope electric hoist always maintains a good operating condition and prolongs its service life, regular lubrication and maintenance are essential. This article will explore in depth the various precautions for lubrication and maintenance of wire rope electric hoists.

1. The importance of lubrication and maintenance
(I) Reduce friction and wear
During the operation of the wire rope electric hoist, there is frequent relative movement between its wire rope and components such as the drum and pulley. If there is a lack of effective lubrication, the friction between these components will increase significantly, thereby accelerating the wear of the surface and internal wire of the wire rope. According to statistics, under the same working conditions, the wear rate of unlubricated wire rope is 3-5 times faster than that of lubricated wire rope. When the degree of wear of the wire rope exceeds a certain limit, its carrying capacity will drop significantly, which is very likely to cause safety accidents such as breakage, posing a serious threat to personnel and equipment.
(ii) Preventing rust
In industrial environments, wire ropes are exposed to the air for a long time and are easily affected by the surrounding environment and rust. Rust not only reduces the strength of the wire rope, but also makes its surface rough and uneven, further aggravating wear. Lubricating oil or grease forms a protective film on the surface of the wire rope, which can effectively isolate moisture, oxygen and various corrosive substances in the air, thereby preventing the wire rope from rusting and maintaining the integrity and stability of its metal surface.
(iii) Improving operating efficiency
Good lubrication can reduce the movement resistance between the wire rope and various components, making the operation of the electric hoist smoother. In this way, the energy required by the motor to drive the wire rope will be reduced, thereby improving the operating efficiency of the entire equipment and reducing energy consumption. At the same time, smooth operation can also reduce the impact force of the equipment when starting and stopping, reduce damage to other components, and improve the overall performance and reliability of the equipment.
(IV) Reduce noise
When dry friction occurs between the wire rope and the drum, pulley and other parts due to lack of lubrication, harsh noise is often emitted. This noise not only pollutes the working environment, affects the work efficiency and physical and mental health of the operator, but also may cover up abnormal sounds during the operation of the equipment, making it difficult to diagnose equipment faults. Regular lubrication can effectively reduce friction noise and create a relatively quiet and comfortable working environment.

2. Preparations before lubrication
(I) Cleaning the wire rope
Before lubrication, the wire rope must be thoroughly cleaned. First, special tools such as wire brushes can be used to carefully remove impurities such as dust, dirt, rust and old grease on the surface of the wire rope. For some stubborn stains that are difficult to remove, special detergents can also be used for cleaning. When cleaning, care should be taken to select a detergent that will not corrode or damage the wire rope, and operate in accordance with the requirements of the product manual. After cleaning, wipe or blow dry the moisture and detergent residue on the surface of the wire rope with a clean rag or compressed air to ensure that the surface of the wire rope is dry and clean so that the new grease can better penetrate into the inside of the wire rope and exert its best lubrication effect.
(II) Check the wire rope
After the cleaning work is completed, the wire rope should be inspected in detail. Focus on checking whether the wire rope has broken wires, deformation, wear, kinks, etc. According to relevant standards and regulations, determine whether the wire rope can continue to be used or whether it needs to be replaced. If the number of broken wires of the wire rope exceeds a certain proportion, or there are serious deformations, wear and other problems, it is difficult to restore its original performance and safety even after lubrication and maintenance. At this time, a new wire rope should be replaced in time to avoid accidents during use.
(III) Choose the right lubricant
Choosing a lubricant suitable for wire rope electric hoists is a key link in lubrication and maintenance. Different working environments, temperature conditions, load sizes and other factors have different performance requirements for lubricants. Common wire rope lubricants are mainly of the following types:
Petroleum-based grease: It has good lubrication and waterproof properties and is suitable for wire rope lubrication in general industrial environments. It is relatively cheap and widely used. However, its performance may be affected to a certain extent in high or low temperature environments.
Synthetic grease: It is made of synthetic base oil and special additives, and has excellent high temperature stability, low temperature fluidity and anti-wear properties. It can maintain good lubrication under extreme temperature conditions and is suitable for wire rope electric hoists working in high temperature, low temperature or other harsh environments. However, its price is relatively high.
Solid lubricant: Such as molybdenum disulfide, graphite, etc., this type of lubricant is usually mixed with a binder and applied to the surface of the wire rope. They have good compressive resistance and high temperature resistance, and have significant lubrication effects under high load and low speed conditions. However, when used alone, the adhesion of its lubricating film is relatively poor and easy to fall off. It generally needs to be mixed with other greases to improve the overall performance.
When choosing lubricants, you should also consider their compatibility with the wire rope material to avoid damage to the wire rope due to chemical reactions between the lubricant and the wire rope. At the same time, you should try to choose brand products with reliable quality and good reputation to ensure the quality and stable performance of the lubricant.
(IV) Prepare lubrication tools
In order to ensure the smooth progress of lubrication work, you also need to prepare some necessary lubrication tools. For example, special wire rope brushes, oil guns, oil brushes, rags, etc. The wire rope brush is used to clean impurities on the surface of the wire rope before applying the lubricant, and to evenly brush the lubricant on the surface of the wire rope during the application process; the oil gun is suitable for injecting grease into the rope core and hard-to-reach parts of the wire rope, which can ensure that the grease fully penetrates into the wire rope; the oil brush can be used to apply some large wire ropes or parts that require a larger coating area; the rag is used to wipe excess lubricant and clean the surface of the equipment. In addition, depending on the type and use of the lubricant, other auxiliary tools such as heating equipment may also need to be prepared to facilitate the use and application of the lubricant.

3. Determination of lubrication cycle
A reasonable lubrication cycle is essential for the lubrication and maintenance of wire rope electric hoists. If the lubrication cycle is too long, the wire rope will lack sufficient lubrication, accelerate wear and rust; if the lubrication cycle is too short, it will cause waste of lubricant and increase maintenance costs and workload. Generally speaking, the determination of the lubrication cycle should take into account the following factors:
(i) Working frequency
If the working frequency of the wire rope electric hoist is high, such as long-term continuous operation every day, the wear and consumption of the wire rope will also accelerate accordingly. In this case, the consumption of lubricating oil or grease will increase, and the effective components of the lubricant will decrease rapidly. Therefore, the lubrication cycle needs to be shortened to ensure that the wire rope is always in a good lubrication state. On the contrary, for those electric hoists that are used occasionally and have a low working frequency, the lubrication cycle can be appropriately extended, but regular inspection and maintenance are still required to ensure the effectiveness of the lubricant.
(ii) Working environment
The working environment has a significant impact on the lubrication cycle. In harsh working environments, such as high humidity, high dust, high temperature, low temperature, chemical corrosion, etc., the wire rope is more susceptible to erosion and damage by external factors. For example, in a high humidity environment, moisture can easily penetrate into the wire rope, causing rust; in a high dust environment, dust will mix into the lubricant, increasing friction and wear. In this case, the performance of the lubricant will decline rapidly, and more frequent lubrication maintenance is required to replenish and update the lubricant to ensure its protective effect on the wire rope. In a relatively clean, dry and mild environment, the lubrication cycle can be appropriately extended.
(III) Service life and status of wire ropes
As the service life of the wire rope increases, its surface and internal structure will change to a certain extent, and the degree of wear will gradually increase. For wire ropes that have been used for a long time, even if the working frequency and environmental conditions are relatively stable, it is necessary to appropriately shorten the lubrication cycle and increase the number of lubrications to slow down its further wear and aging. At the same time, before each lubrication, the status of the wire rope should be carefully checked. If the wire rope is found to have obvious broken wires, deformation, increased wear, etc., the lubrication cycle should be adjusted in time, and replacement of new wire ropes should be considered to ensure the safe operation of the equipment.
Generally speaking, for electric wire rope hoists used in normal working environments and with moderate working frequencies, it is recommended to lubricate and maintain the wire rope once every half a month to one month; electric wire rope hoists used in harsh environments need to be lubricated once every half a month or even once a week.

4. Common lubrication methods
(I) Smearing method
The smearing method is one of the most commonly used wire rope lubrication methods. During operation, apply an appropriate amount of grease on a special brush or rag, and then evenly apply the grease on the surface of the wire rope along the length of the wire rope. During the smearing process, the grease should be penetrated into the inner rope core of the wire rope and between the strands of steel wire as much as possible to achieve a comprehensive lubrication effect. In order to improve the efficiency and quality of smearing, some special smearing tools, such as wire rope lubrication brushes, can also be used. The smearing method is suitable for various types of wire ropes and greases. The operation is relatively simple and easy to control the amount of grease and the quality of smearing. However, its disadvantage is that for some longer wire ropes or parts that are difficult to directly contact, the smearing process may be cumbersome and uneven smearing is prone to occur.
(ii) Dipping method
The dipping method is usually used to lubricate some small, detachable wire rope parts or short sections of wire rope. Soak the wire rope in a container containing grease, and make the grease fully penetrate into the inside of the wire rope by heating or pressurizing. This method can ensure that the grease is evenly distributed on all parts of the wire rope, and the lubrication effect is better. However, the dipping method requires special equipment and operating space. For the wire rope of large wire rope electric hoists, it is relatively inconvenient to operate, and more grease may be wasted during the soaking process.
(iii) Oil gun injection method
For some large wire rope electric hoists or parts that are difficult to directly apply grease, such as the rope core of the wire rope, the inside of the drum, etc., an oil gun can be used for injection lubrication. Aim the nozzle of the oil gun at the part that needs to be lubricated, and inject the grease into the inside of the wire rope through the pressure of the oil gun. This method can accurately deliver the grease to the target part, ensure the effective penetration and distribution of the grease, and is suitable for various greases with higher viscosity. However, it should be noted that when using an oil gun for injection lubrication, the amount of grease injected should be controlled to avoid excessive lubrication leading to grease leakage and waste.
(IV) Circulating lubrication system
Some modern large-scale wire rope electric hoists are equipped with a circulating lubrication system. The system extracts the lubricating oil from the oil tank by setting up oil pumps, oil pipes, filters and other devices inside the equipment, and after filtering and cooling, it is transported to the wire rope and other parts that need lubrication, and then the lubricating oil flows back to the oil tank for recycling. The circulating lubrication system can automatically and evenly provide lubricating oil to the wire rope to ensure that it is always in a good lubricated state. At the same time, it can also filter and cool the lubricating oil to extend the service life of the lubricating oil. However, the equipment investment cost of this lubrication system is high, and the maintenance and management are relatively complex. It is generally suitable for large-scale wire rope electric hoists with high lubrication requirements and high working intensity.

5. Detailed steps of lubrication operation
(I) Local lubrication
First, use tools such as wire brushes to clean the dirt and impurities on the surface of the wire rope, focusing on cleaning the areas where the wire rope contacts the drum, pulley, and the cross-winding of the wire rope, which are prone to dirt accumulation.
According to the diameter and length of the wire rope, take an appropriate amount of grease and put it into a special container, immerse the wire brush or oil brush in the grease to fully absorb the grease.
Starting from one end of the wire rope, along the length of the wire rope, place the wire brush or oil brush close to the surface of the wire rope, move slowly at a uniform speed, and evenly apply the grease on the wire rope. During the application process, appropriate force should be applied to allow the grease to penetrate into the internal rope core of the wire rope and between the strands of steel wire. For some cross-winding and bending parts of the wire rope, it should be applied repeatedly to ensure that these parts with more severe wear can be fully lubricated.
After applying a section of wire rope, wipe off the excess grease on the surface of the wire rope with a clean rag to avoid excessive grease affecting the normal operation of the equipment. When wiping, it should be done along the twisting direction of the wire rope to reduce damage to the surface of the wire rope.
(II) Comprehensive lubrication
For some large wire rope electric hoists, a combination of oil gun injection and smearing can be used for comprehensive lubrication. First use an oil gun to inject grease into the rope core and drum of the wire rope, and then use the smearing method to evenly apply the surface of the wire rope to ensure that the entire wire rope is fully lubricated.
When lubricating the pulley block, the protective cover around the pulley should be opened first to clean the dust and debris on the pulley surface and the shaft neck. Then, use an oil gun or brush to apply lubricating oil or grease to the shaft neck and bearing of the pulley to ensure that the pulley can rotate flexibly. After the smearing is completed, reinstall the protective cover to prevent dust and dirt from entering the pulley.
Other moving parts of the electric hoist, such as the hook, small wheel, gear, etc., should also be lubricated according to the equipment's operating manual and lubrication requirements. Generally, the pin of the hook, the rim and bearing of the small wheel, the tooth surface of the gear, etc. need to be lubricated regularly to reduce wear and friction and ensure the normal operation of the equipment.

. In6spection and maintenance after lubrication
(I) Check the lubrication effect
After completing the lubrication work, the lubrication effect should be carefully checked to ensure that the grease or lubricating oil has been evenly covered on the surface of the wire rope and other parts that need lubrication, and there is no obvious omission or unevenness. Observe whether the grease on the surface of the wire rope presents a bright and uniform color. If some areas are lighter or darker in color, it means that the lubrication is uneven and needs to be reapplied or the lubrication method needs to be adjusted. At the same time, the wire rope or other parts of the equipment can be manually rotated to check whether it is running smoothly, whether there is any jamming, abnormal noise, etc. If you feel a lot of resistance or hear abnormal noise during the rotation process, it may be due to insufficient lubrication or the lubricant has not fully penetrated into the interior. Further lubricant needs to be added or troubleshooting needs to be performed.
(II) Cleaning up excess lubricant
In order to ensure the cleanliness and normal operation of the equipment, it is necessary to clean up the excess lubricant applied on the surface of the wire rope. Use a clean rag or paper towel to wipe off the excess lubricant on the surface along the twisting direction of the wire rope to prevent it from being thrown out during operation, polluting the surrounding environment of the equipment or causing adverse effects on other components. At the same time, the lubricant remaining on the surface of other parts of the equipment, such as pulleys and drums, should also be properly cleaned to ensure that the surface of the equipment is neat and beautiful, which is convenient for subsequent inspection and maintenance.
(III) Record lubrication conditions
Establish a complete lubrication record system to record in detail the time of each lubrication, the type and brand of lubricant used, the lubrication part, the lubrication method, and the operator. These records not only help to understand the lubrication history and maintenance of the equipment, but also provide an important basis for formulating future lubrication plans. By analyzing the lubrication records, the rules and potential problems of the equipment in terms of lubrication can be discovered, the lubrication cycle and method can be adjusted in time, the lubrication maintenance work can be optimized, and the reliability and service life of the equipment can be improved.
(IV) Regular review
Even after lubrication is completed, the wire rope electric hoist should be reviewed regularly to ensure that the equipment is always in a good lubrication state. The inspection cycle can be determined according to the actual working conditions and lubrication cycle of the equipment. It is generally recommended to conduct a detailed inspection at least once a month. During the inspection, focus on checking whether the lubricant on the surface of the wire rope is intact, whether it has dried up, fallen off, deteriorated, etc.; check whether the pulley, drum and other parts are running smoothly, whether there is abnormal wear or damage; observe whether other moving parts of the equipment are loose, deformed, etc. If problems are found, appropriate measures should be taken in time to deal with them, such as replenishing lubricants, adjusting the position of components, replacing damaged parts, etc., to ensure the safe and stable operation of the equipment.

7. Precautions for lubrication and maintenance
(I) Safe operation
Before performing lubrication and maintenance work on the wire rope electric hoist, it is necessary to ensure that the equipment has been completely stopped and the power supply has been cut off to prevent the equipment from suddenly starting during operation, causing casualties and equipment damage. Operators should wear appropriate labor protection supplies, such as safety helmets, gloves, protective glasses, etc., to avoid being injured during operation. When using tools such as oil guns and brushes, attention should be paid to the correct operation method to avoid tools slipping or accidentally injuring operators. At the same time, when applying lubricants, avoid direct contact with eyes and skin. If accidentally contaminated, rinse with clean water immediately and take appropriate treatment measures according to the properties of the lubricant.
(ii) Avoid mixing different types of lubricants
Different lubricants have different compositions, properties and working principles. Mixing may cause chemical reactions between lubricants, produce precipitation, gel and other substances, destroy the normal performance of lubricants, reduce lubrication effect, and even cause damage to wire ropes and equipment. For example, when petroleum-based grease is mixed with synthetic grease, compatibility problems may occur, resulting in changes in the consistency, adhesion and other properties of the grease, affecting its lubrication and protection of the wire rope. Therefore, when replacing lubricants, the old lubricant on the wire rope should be thoroughly cleaned first, and the new lubricant should be applied after the surface is dry to avoid mixing new and old lubricants. If you are not sure whether different lubricants can be mixed, you should consult the lubricant manufacturer or professional technicians for advice.
(iii) Storage of lubricants
The storage conditions of lubricants have an important impact on their performance and service life. Lubricants should be stored in a dry, cool, well-ventilated warehouse to avoid direct sunlight, high temperature baking, rain and other conditions. At the same time, lubricants should be stored in categories to avoid mixing lubricants of different types and specifications to avoid misusing them. During storage, attention should also be paid to the shelf life of the lubricant, and the principle of "first in, first out" should be followed to avoid long-term storage causing the lubricant to deteriorate and become ineffective. For lubricants that have been opened and used, they should be used up as soon as possible. If they need to be stored for a long time, they should be sealed and kept, and marked with information such as the opening date, so that it can be accurately judged whether it is still usable when it is used next time.
(IV) Pay attention to changes in the quality of lubricants
During the lubrication and maintenance process, not only should lubrication be performed according to the prescribed cycle and method, but also attention should be paid to changes in the quality of the lubricant itself. If the lubricant is found to have a darker color, abnormal odor, and an increase in impurities, it may indicate that the lubricant has deteriorated or been contaminated. At this time, a new lubricant should be replaced in time to ensure the lubrication effect. In addition, the performance of the lubricant should be tested regularly, such as viscosity, flash point, dropping point and other indicators, to ensure that it meets the use requirements of the equipment. For some important equipment or wire rope electric hoists used in harsh environments, it is recommended to use high-quality lubricants with reliable quality and good stability, and shorten the inspection cycle to promptly discover and deal with lubricant quality problems.
(V) Follow the advice of the equipment manufacturer
When designing and producing wire rope electric hoists, equipment manufacturers have made detailed considerations and regulations on their lubrication and maintenance requirements. Therefore, when performing lubrication and maintenance work, users should strictly follow the operation manual and recommendations provided by the equipment manufacturer, and operate according to the specified lubrication parts, lubricant types, lubrication cycles and methods. Do not change the lubrication plan or use lubricants that do not meet the requirements at will, so as not to adversely affect the equipment, or even cause equipment failures and safety accidents. If you encounter any problems or uncertainties during the lubrication and maintenance process, you should contact the equipment manufacturer or its authorized after-sales service agency in a timely manner to seek professional technical support and guidance.

8. Summary
The lubrication and maintenance of wire rope electric hoists are of great significance to ensure the safe operation of equipment, extend service life, improve work efficiency and reduce maintenance costs. By correctly selecting lubricants, reasonably determining lubrication cycles, adopting appropriate lubrication methods, and strictly observing various precautions for lubrication and maintenance, the wear and corrosion of wire ropes and equipment components can be effectively reduced, and the operating efficiency and reliability of the equipment can be improved. At the same time, establishing a sound lubrication record system and regular inspection mechanism, timely discovering and handling problems that arise during lubrication and maintenance, can further optimize the maintenance and management of equipment and ensure the stability and safety of wire rope electric hoists in production operations.

In short, the lubrication and maintenance of wire rope electric hoists is a long-term, meticulous and non-negligible work. Only by integrating lubrication and maintenance work throughout the entire life cycle of the equipment and organically combining it with daily inspection, maintenance and repair work can the performance advantages of wire rope electric hoists be fully utilized to create greater economic benefits and safety guarantees for enterprises.