What are the requirements for the packaging of bearings?

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For bearing products, packaging is very important, not only to prevent rust, but also to protect the bearing from bumps during transportation and damage to the bearing. Bearing packaging is divided into inner packaging and outer packaging. So, what are the requirements for the packaging of bearings?

First, the inner packaging of the bearing

After the bearing is manufactured and passed the inspection, it will be cleaned and anti-rust treated, and then put into the inner packaging to achieve the purpose of waterproof, moisture-proof, dust-proof, shock-proof, maintain the quality and accuracy of the bearing, and facilitate the use and sale. .

1. The inner packaging of the bearing is divided into three categories according to the anti-rust period

① Short anti-rust period packaging

The anti-rust period is 3-6 months, which is suitable for bearings that are shipped to the same subscriber in large quantities and put into use in a short period of time. The two parties have agreed to use simple packaging based on the principle of ease of use.

② General anti-rust period packaging

The anti-rust period is one year, suitable for general-purpose bearings.

③ Long anti-rust period packaging

The anti-rust period is two years, suitable for special and precision bearings.

2, bearing inner packaging material requirements

There are polyethylene plastic tube (box), kraft paper, plain and wrinkled polyethylene composite paper, paper box, polyethylene or polyethylene plastic film, nylon fastening tape or plastic woven fastening tape, waterproof high-strength plastic tape, burlap bag, etc. . All of the above materials need to ensure that the corrosion resistance test of the material is qualified.

3, the requirements of bearing inner packaging method

①Miniature bearing

Every 10~15 sets of bearings are packed into a plastic tube, and every 5~10 plastic tubes are packed into a carton (or bag or roll pack).

②Medium and small bearings

Multiple sets of bearings are wrapped with polyethylene film, kraft paper or polyethylene composite paper for external use; multiple sets of bearings are packed into a plastic tube (box); single set of bearings is packed in polyethylene film bags, folded or sealed before repacking Into a paper box.

③Large bearing

Pack it in a single set of polyethylene film or polyethylene composite paper, and then put it into a carton; use a polyethylene film bag, pack the single set of folded bag openings, and then put it into a carton; put the single set into a special plastic box; Three-layer wrap-around packaging: polyethylene film tape or composite paper tape for the inner layer, fastening tape for the middle layer, and waterproof permeable plastic tape for the outer layer.

④Extra large bearing

Single set of three-layer wrapping packaging (same as above).

Single-by-four-layer wrapping package: After the above-mentioned three-layer wrapping package, the outer layer is wrapped with a layer of linen tape.

For separable tapered roller bearings with outer diameter ≥150mm, the inner and outer components should be lined with polyethylene film before packaging, or the inner and outer components should be packaged separately. For interchangeable cylindrical roller bearings with an outer diameter of ≥150mm, because the complete package is easy to be damaged, the inner and outer components can generally be packaged separately.

Secone. Standards for bearing outer packaging requirements

1. General materials and requirements for outer packaging of bearings

① Double corrugated boxes, the total weight (gross weight) of each box does not exceed 25kg, and the outside of the box is bound with plastic strapping.

② Nail board box (wooden box), the total weight of each box does not exceed 30kg, and the outside of the box is bound with blue steel tape.

③ Calcium plastic corrugated box, the total weight of each box does not exceed 25kg, and the box is bound with plastic strapping.

When packing bearing products with inner packaging into the box, plastic bags or plastic films should be lined in the box first; if there are gaps in the box, it should be filled with corrugated paper blocks, paper scraps and other dry materials.

2, pay special attention

It is especially important to emphasize that due to the heavy weight of large bearings, packing straps should be added to the packaging box to ensure the convenience of bearing handling and other processes. For the packaging of large bearings, each manufacturer has its own characteristics, such as the material requirements for the outer packaging, anti-counterfeiting marks, and so on.

Compared to other products, the packaging and transportation of bearings are very important. Whether it is a bearing manufacturer or a motor manufacturer, we are inseparable from the transportation link without exception. We must fully communicate with the transportation party and take necessary precautions.

How to maintain the crane slewing ring?

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The slewing bearing is an important “joint” of the crane, so its maintenance is very important. So how to maintain the crane slewing ring?

When carrying out maintenance work, the first thing to pay attention to is the danger of being dragged into the rotating pinion, as well as the danger of crushing and shearing. When performing the following tasks, make sure that when starting the engine to perform the necessary slewing and luffing actions, any maintenance personnel are not in the danger zone between the main boom, the upper car and the reel, or between the exit and the reel. Dangerous areas, except for crane operators (in the driver’s cab).

1. Check the bolts of the slewing ring

1. Before each crane work or at least once a week, visually inspect the bolts on the slewing ring;

2. After the slewing ring has been working for 100 working hours, check whether the bolts are loose or not. Check again at the 300th working hour; check every 500 working hours thereafter; shorten the inspection interval for severe working conditions. If the bolts are found to be loose during the inspection, please stop the construction work and contact the local after-sales service department immediately. The factory or professional technicians will inspect and decide whether to disassemble and inspect immediately.

3. The slewing ring is filled with lithium grease before installation.

4. When replacing bolts, wipe the bolts clean, apply thread fastening glue and tighten them; use a crane in accordance with the requirements of the operation manual and lifting performance table, or check the fastening bolts regularly as required to avoid fatigue damage of the bolts. danger.

2. Routine inspection of slewing ring

1. Regularly check the flexibility of rotation; if noise or impact is found, stop the machine for inspection and troubleshoot immediately, and dismantle and inspect if necessary;

2. Regularly check whether the rotary gear ring is cracked or damaged, and whether the meshing tooth surface has biting, gnawing, peeling, etc.;

3. Regularly check the integrity of the seal. If the seal band is found to be damaged, it should be replaced in time, and if it is found to be off, it should be reset in time.

Three, lubricate the tooth surface of the slewing ring

The slewing ring gear has been coated with anti-rust oil before leaving the factory. The effective period of this anti-rust is generally 3 to 6 months. After the effective period, the anti-rust oil should be coated in time. In addition, during use, prevent the slewing bearing from being directly exposed to sunlight. It is forbidden to rinse the slewing bearing directly with water to prevent water from entering the raceway, and prevent hard foreign objects from approaching or entering the tooth meshing area.

Fourth, the raceway of the sliding slewing ring

The raceway must be filled with grease regularly according to the working environment. After working for 50 working hours, the raceway should be filled with lubricating grease, and then again every 300 working hours. The slewing bearing must be filled with grease before and after being placed for a long time.

If using a steam jet cleaner or a fixed water sprayer to clean the crane, care must be taken to ensure that water does not seep into the slewing ring connection, and then the slewing ring connection must be lubricated. In special working environments, such as tropical, high humidity, dust, large temperature changes, and continuous work, the lubrication cycle should be shortened.

Grease filling should be carried out when the slewing ring rotates slowly. When the lubricating grease overflows from the seal, the filling is completed. The overflowing grease will form a thin film to act as a seal.

Which bearings are used in wind turbines?

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Wind turbines are installed in areas with windy sand or relatively high humidity in the wild. The working conditions of wind turbine bearings are very harsh, and the temperature, humidity, and load that need to be subjected to a wide range of changes. In particular, the yaw and pitch bearings need to withstand large axial forces and overturning moments, and the gearbox bearings need to withstand huge shock loads during starting and braking. At the same time, the wind turbine gearbox bearings are required to have low friction when starting at low speeds. Features of torque and high operating flexibility. There are as many as 32 sets of bearings for a wind turbine. Therefore, the selection of bearings is very important to ensure the safe and stable operation of wind turbines. So, which bearings are used in wind turbines?

 

Wind turbine bearings are generally divided into the following types: yaw bearings, pitch bearings, main shaft bearings, gearbox bearings and generator bearings. According to different bearing types, technical requirements are also different.

 

1, yaw, pitch bearing

 

This type of bearing is generally designed as an assembly. Single-row four-point contact ball slewing bearings or double-row four-point contact ball slewing bearings should meet the following technical requirements:

 

According to the force characteristics of the wind turbine bearing, the yaw bearing adopts a small clearance, and the pitch bearing adopts a four-point contact ball bearing with zero clearance or “negative clearance” design. The channel needs to be specially designed and processed to withstand large The axial load and moment load. The yaw gear in the assembly should choose the appropriate material, modulus, tooth profile and hardness to ensure the life matching with the driving gear. At the same time, targeted heat treatment measures must be taken to improve the strength of the tooth surface, so that the bearing has good wear resistance and impact resistance.

 

Because the fan is exposed to the field, there are strict requirements on the sealing performance of the bearing, and the sealing form of the bearing must be optimized to ensure that the life of the bearing is the same as that of the fan. Fans are installed at an altitude of more than 50m or even hundreds of meters. The assembly and disassembly costs are expensive. Therefore, they must have very high reliability. Generally, the life span of 20 years is required. In addition, the bearing structure is complicated, so the design and manufacturing requirements are extremely high.

 

 

 

2, spindle bearing

 

Spindle bearings are generally spherical roller bearings, and some have double-row tapered roller bearings with large taper angles. Most of the impeller spindles are supported by two spherical roller bearings. Because the load of the main shaft of the impeller is very large, and the shaft is very long and easy to deform, the bearing must have good centering performance.

 

3, gearbox bearing

 

There are many types of gearbox bearings, including deep groove ball bearings, cylindrical roller bearings, full complement cylindrical roller bearings, double row tapered roller bearings, spherical roller bearings, thrust spherical roller bearings and four Point contact ball bearings.

 

The bearings in the gearbox are mainly lubricated by the gear oil in the gearbox. There are more metal particles in the lubricating oil, which will obviously affect the life of the bearing. Therefore, a special heat treatment process is required to make the surface of the raceway have compressive stress and reduce the raceway. Sensitivity to particle impurities improves bearing life. At the same time, it is also necessary to optimize the bearing structure according to the working conditions of the bearing, improve the processing technology of the bearing, and further improve the performance index of the bearing.

 

4, generator bearing

 

The generator bearing adopts cylindrical roller bearing and deep groove ball bearing. It is necessary to reduce the noise of bearing vibration through the structural design of these two kinds of bearings, the improvement of processing methods, the cleanliness control of the production process and the optimization of related components, so that the bearing has a good low-noise performance.

 

The above is the answer to which bearings are used in wind turbines. The bearings used from the main shaft to the generator are collectively referred to as transmission system bearings. Most of these bearings are standard bearings in terms of structure. The difference is that in order to ensure high reliability, In addition to some special requirements in terms of materials and heat treatment, other key technologies need to be adopted.