Precautions for the use of needle roller bearings?

Precautions for the use of needle roller bearings: the bearing should be injected with an appropriate amount of grease before installation, and under normal circumstances, there is no need to lubricate after assembly BK type bearings are used in the support of the non-protruding end of the journal, and the end face is closed to play a sealing role, and can withstand small axial travel. Needle roller bearings are roller bearings with cylindrical rollers, which are both thin and long relative to their diameter.

Such rollers are called needle rollers. Despite their small cross-sections, the bearings have a high load bearing capacity, and the needle roller bearings are equipped with slender and long rollers (roller diameter d 5mm, l d and l are the roller lengths), so they are compact in radial design, and their inner diameter and load capacity are the same as those of other types of bearings, with a small outer diameter, which is particularly suitable for support structures with limited radial mounting dimensions. According to different occasions of use, the bearing without inner ring or needle roller and cage assembly can be selected, at this time, the journal surface and the shell hole surface matched with the bearing are directly used as the inner and outer rolling surface of the bearing, in order to ensure that the load capacity and running performance are the same as the bearing with the ring, the hardness, machining accuracy and surface quality of the raceway surface of the shaft or shell hole should be similar to the raceway of the bearing ring.

This type of bearing can only withstand radial loads.

Applications of needle roller bearings |Precautions for the use of needle roller bearings.

The role of needle roller bearings.

Needle roller bearings are widely used in automobiles, motorcycles, mopeds, power tools, textile machinery, agricultural machinery, industrial sewing machines, and construction machinery. It has a low cross-sectional height and a high load-bearing capacity. The needle retaining bearing for general purpose is a bearing with excellent performance at high speed, and the needle roller is correctly guided by a retainer with a special shape with high rigidity and precision, and the dimensional error is extremely low.

In addition, they are particularly suitable for use in small spaces, because they have a fairly high lubricant capacity, light weight and high rigidity, which can be used in harsh situations, such as high speeds, impact loads, etc., so they are widely used. Needle Roller Bearing Type:

It can be divided into two structures: with an inner ring (NA) and without an inner ring (RNA).

1. The needle roller bearing of the stamping outer ring has two kinds of perforation type and sealing type, the needle roller bearing of the stamping outer ring does not have an inner ring, and the needle roller is in direct contact with the surface of the shaft, so the machining accuracy and heat treatment hardness of the shaft should be the same as that of the inner ring of the bearing.

Scope of application: Stamped outer ring needle roller bearings with cage are suitable for high speed and heavy load, and are mostly used in machine tools, automobiles, motorcycles, gearboxes or textile machinery. Cageless stamped ring needle roller bearings, which are fitted with needle rollers, are suitable for oscillating working conditions under heavy loads.

Such as the frame of an aircraft, the shaft end of the main wing of a missile, etc.

2. Solid ring needle roller bearing Solid ring needle roller bearing, commonly used solid ring needle roller bearing is NA type and RNA type.

Scope of application: Solid ring needle roller bearings are mostly used in machine tools and automobile gearboxes, and its advantages are small radial section size and large radial load. The standard type of solid ring needle roller bearings have cages, so the speed is high, and can meet the requirements of machine tools and automobile gearboxes.

3. Roller needle roller bearing.

Scope of application: printing machinery, forage machinery, agricultural machinery, CNC equipment guide rails with rollers, conveyor lines, etc.

4. Needle roller and cage assembly. Needle roller and cage assemblies are actually ringless needle roller bearings.

Scope of application: This kind of bearing is mostly used in the large and small ends of the connecting rods of gearboxes, motorcycles and automobiles. Due to the increase in the internal temperature of the cylinder, the bearing should be resistant to high temperatures.

Applications of needle roller bearings |Precautions for the use of needle roller bearings.

Precautions for the use of needle roller bearings.

1. The needle roller bearing has a large bearing capacity, which is suitable for the supporting structure with limited installation size, the surface of the journal is hardened as a rolling surface, and the bearing is loaded into the seat hole with a press-fit fit, so there is no need to position it axially.

2. The bearing should be injected with an appropriate amount of grease before installation, and under normal circumstances, there is no need to lubricate after assembly BK type bearings are used in the support of the non-extended end of the journal, and the end face is closed to play a sealing role, and can withstand small axial swimming.

1.After installing the bearing, it is first used for rotating shaft or bearing box, if there is no abnormality, it will be used for no-load and low-speed operation with power, and then gradually increase the rotation speed and load according to the operation situation, and detect noise, vibration and temperature rise, and if the abnormality is found, the operation should be stopped and checked;

2.It is not allowed to drill, groove, chamfer, and turn the end face on the imported bearing during installation. Otherwise, it is easy to cause the deformation of the imported bearing ring, affect the accuracy and life of the bearing, and at the same time, the metal cut off is easy to enter the working surface of the bearing, accelerate the wear of the raceway and the rolling element, and cause premature damage to the bearing;

3.When installing, the pressure should be added to the end face of the ring with an interference fit, that is, when installed on the shaft, the pressure should be added to the end face of the inner ring of the bearing; When installed in the housing bore, the pressure should be added to the end face of the outer ring of the inlet bearing. It is not allowed to pass the pressure through the rolling elements and hold;

In the process of using the roller, the following groups of people need to be cautious in the use of the roller: osteoporosis, diabetes, hypertension, varicose veins, these four groups of people need to pay attention to the control during use, do not apply excessive pressure.

Patients with osteoporosis.

In most cases, the bones of the spine, neck and femur are more sensitive than those in other parts of the body. People with osteoporosis should use it reasonably according to their severity, and if the disease is mild, they can safely roll the foam roller in a part that does not produce too much pressure. If the condition is severe, it is recommended to follow the advice of a doctor or physicist for a relaxing massage.

Diabetic.

The restriction of use in diabetic patients is due to some complications in diabetic patients that are not suitable for roller use, such as neuropathy, numbness of limbs, vascular damage and capillary damage.

Foam roller rolling in an area with neuropathy has the potential to trigger additional pain, and there are currently no studies showing that foam roller rolling has a positive effect on the nerves, therefore, foam roller rolling is not recommended when nerve pain is felt.

Patients with numbness of the limbs have inconspicuous sensitive points, and high blood sugar leads to arteriosclerosis, which leads to heart disease, stroke, poor blood circulation in the lower legs and feet, and if excessive pressure is applied, tissue contusion and damage may occur. If the circulation is normal and sufficient blood and oxygen is delivered to the lower limbs, the contusion can recover quickly, but with diabetes, the recovery process is not as fast. Patients with this condition should follow the recommendations of their doctor or physicist.

High blood pressure In patients with high blood pressure, the factors considered are elevated blood pressure due to body posture and breathing patterns.

When rolling in a flat lying position, the heart and body parts are at the same level, which may cause an increase in blood pressure.

Another consideration is that the pain caused by the rolling process may cause the patient to hold their breath, which can lead to an increase in blood pressure if they hold their breath for a long time.

Therefore, do not apply excessive pressure during the use of the roller, so as not to passively cause blood pressure to rise, and maintain natural breathing and relaxation during use to avoid blood pressure increase.

Varicose Veins Because varicose veins have distinctly raised blood vessels under the skin, the lower extremities are the most common areas prone to varicose veins due to gravity. The function of the veins is to transport deoxygenated blood from the whole body back to the heart, and the foam roller will exert too much pressure on the veins in the area, affecting the blood return, and in severe cases, causing damage to the blood vessels. Therefore, when using rollers, it is necessary to avoid rolling this area as much as possible.

In addition to the above, it is necessary to avoid rolling pressure on some areas where the nerves are concentrated and sensitive, such as the neck, lower back, ribs, abdomen, groin and popliteal fossa.

There are two methods: bearing disassembly and bearing lubrication. 1. Bearing disassembly and assemblyThe bearings should be cleaned before installation.

During installation, special tools should be used to straighten and even the auxiliary bearings. Don't hit it with a hammer. In particular, it is forbidden to strike the bearing directly.

When the housing ring fits loosely, the housing hole should be repaired or the bearing replaced. Do not force yourself to use pitting or copper pads on the mating surface of the bearing. When disassembling the bearing, use the appropriate pull tool to pull out the bearing. Do not hit the bearing with a chisel, hammer, etc.

2. Bearing lubricationThere are two types of lubricants commonly used in rolling bearings: oil and grease. When the circumferential speed of the shaft is less than 4-5ms or the parts on the car cannot be lubricated with lubricating oil, grease should be used for lubrication.

The advantages of grease lubrication are that the sealing structure is simple, the grease loss is low, the temperature is less affected, and it can be used for a long time with one grease.

The main scope of application of needle roller bearings: transmission devices for automobiles, cultivators, machine tools, etc.

Specific classification and model comparison:

1. Centripetal needle roller and cage assembly (K type).

2. Needle roller bearings with double locking rings in the outer ring (NA TYPE, NKI type, RNA type, NK type) 3. Single row needle roller bearings with double flanges in the outer ring (NA TYPE, NKI type, RNA type, NK type) 4. Double row needle roller bearings with double flanges in the outer ring (NA type, RNA type) Note: NA type bearings bear radial loads and have small outer diameters, which are especially suitable for structures with limited radial installation dimensions.

RNA is suitable for structures with limited radial mounting dimensions, and the journal surface is directly used as a rolling surface, and the rolling surface hardness is generally (* 62 = 8"Single row bearings">!-199 is the outer ring with a double lock ring"> ;The outer ring of the 199 has double flange double row bearings">"The 2199 only bears radial loads and has a high ultimate speed.

5. Stamped outer ring needle roller bearing (HK type, BK type).

Note: This kind of bearing has low cost, large bearing capacity, suitable for supporting structures with limited installation size, the surface of the journal is hardened as a rolling surface, and the bearing is loaded into the seat hole with a press-fit fit, so there is no need to position it axially. The bearing should be injected with an appropriate amount of grease before installation, and under normal circumstances, there is no need to lubricate it after assembly BK type bearings are used in the support of the non-protruding end of the journal, and the end face is closed to play a sealing role, and can withstand small axial travel force.

You can consult the technical department of Changzhou Yangfan bearing, and I heard that they invited experts in the bearing industry to work, with an annual salary of 500,000 yuan.

There are many kinds of needle roller bearings, different types of use of different environments, you are too general, what do you want to ask, is there a specific type or model?

Needle roller bearings are equipped with thin and long rollers (the roller length is 3 10 times the diameter, and the diameter is generally not more than 5 mm), so the radial structure is compact, and its inner diameter and load capacity are the same as those of other types of bearings, and the outer diameter is the smallest, especially suitable for support results with limited radial installation dimensions. According to different occasions of use, the bearing without inner ring or needle roller and cage assembly can be selected, at this time, the journal surface and the shell hole surface matched with the bearing are directly used as the inner and outer rolling surface of the bearing, in order to ensure that the load capacity and running performance are the same as the bearing with the ring, the hardness, machining accuracy and surface quality of the raceway surface of the shaft or shell hole should be similar to the raceway of the bearing ring. This type of bearing can only withstand radial loads.

In terms of its function, it should be a support, but this is only part of its role, and the essence of support is to be able to bear radial loads. It can also be understood that it is used to fix the shaft. It is to fix the shaft so that it can only rotate, and control its axial and radial movement.

For example, if the motor does not have bearings, the consequence is that it cannot work at all. Because the shaft can move in any direction, and the motor requires the shaft to only rotate when working.

Theoretically it is impossible to realize the role of transmission, not only that, the bearing will also affect the transmission, in order to reduce this impact on the bearing of the high-speed shaft must achieve good lubrication, some of the bearing itself has lubrication, called pre-lubricated bearing, and most of the bearing must have lubricating oil, otherwise in high-speed operation, due to friction will not only increase energy consumption, more terrible is that it is easy to damage the bearing.

Advantages: Needle roller bearings.

The outer diameter is small, so the structure is very compact, light weight, and easy to carry; Exquisite structure and friction resistance; The bearing capacity is good, the performance is stable, the load is large, and it is widely used.

Disadvantages: complex processing technology, production cost.

Any modern equipment is composed of countless small parts of the combination of assembly, do not underestimate these parts, do not look at these parts are very small, but it is indispensable, such as the common mechanical parts bearing, widely used in machinery industry equipment, in order to be suitable for a variety of mechanical equipment, its types have developed to countless to meet the requirements of the equipment, to ensure that it can perfectly guide the rotary movement of the shaft, and bear the load transmitted by the shaft to the frame. For more information, you can consult Mobei, and Mobeiwang provides you with real-time supply and demand information for bearings. Needle Roller Bearings Needle roller bearings are equipped with thin and long rollers (the length of the rollers is 3 10 times the diameter, and the diameter is generally not more than 5mm), so the radial structure is compact, and its inner diameter size and load capacity are the same as those of other types of bearings, and the outer diameter is the smallest, especially suitable for supporting structures with limited radial installation dimensions.

Needle roller bearing according to the use of different occasions, can choose the bearing without inner ring or needle roller and cage assembly, at this time with the bearing matching journal surface and shell hole surface directly as the bearing of the inner and outer rolling surface, in order to ensure the load capacity and running performance and the same as the ringed bearing, the hardness of the shaft or shell hole raceway surface, machining accuracy and surface quality should be with the bearing ring. Application: The combined needle roller bearing is a bearing unit composed of radial needle roller bearing and thrust bearing components, which has a compact structure and small size, high rotation accuracy, and can bear a certain axial load while bearing a high radial load. And the product structure is diverse, adaptable and easy to install.