INFO

Needle bearing is a kind of roller bearing with cylindrical roller. Compared with its diameter, the roller is thin and long. This kind of roller is called needle roller. Although the bearing has a small cross section, it still has a high load bearing capacity. The needle roller bearing is equipped with thin and long rollers (roller diameter D ≤ 5mm, L / D ≥ 2.5, l is the roller length), so the radial structure is compact. When its inner diameter and load capacity are the same as other types of bearings, the outer diameter is the smallest. It is especially suitable for the support structure with limited radial installation size.

The bearing without inner ring or needle roller and cage assembly can be selected according to different application situations. At this time, the journal surface and shell hole surface matched with the bearing are directly used as the inner and outer rolling surfaces of the bearing. In order to ensure the same load capacity and running performance as the ring bearing, the hardness, machining accuracy and surface quality of the shaft or shell hole raceway surface should be similar to the raceway of the bearing ring. This kind of bearing can only bear radial load.

TYPE

Except as listed in the standard type, it can be used for general engineering bearings, such as: open type stamping outer ring needle roller bearing (1), closed stamping outer ring needle bearing (2), needle roller bearing with inner ring (3) and needle roller bearing without inner ring / no inner race without cage needle roller bearing (4), full needle bearing with cage and cage free (5)

Drawn Cup
The needle roller bearing of the stamping outer ring is a needle roller bearing with thin stamping forming outer ring. The main feature of the method is that the section height is very low and the load bearing capacity is high. It is mainly used for the bearing configuration of compact structure, low price and bearing box hole can not be used as roller track of needle holder assembly. The bearing and bearing housing shall be installed in interference fit mode. If the axial positioning functions such as shoulder and stop ring can be omitted, the bore in the bearing box can be very simple and economical. The needle roller bearing of the stamping outer ring installed at the end of the shaft has two sides open type and one side closed type. The base end face of the closed stamping outer ring can bear little axial guiding force. The needle roller bearing of the stamping outer ring is not attached with the inner ring generally. In cases where the journal cannot be hardened and ground, the inner rings listed in the table can be used. The hardened steel plate outer ring of the needle roller bearing of the stamping outer ring and the needle holder assembly cannot be separated. Free space for storing lubricants can extend the replenishment interval. Bearings are generally designed in single row. Except for the wide range of bearings 15221622220302538 and 3038, they are equipped with two needle holder assemblies. The bearing outer ring has a lubricating oil hole. According to the user's needs, all single row needle roller bearings with shaft diameter of 7mm or greater can be equipped with outer rings with lubricating oil holes (code suffix AS1). The needle roller bearing with oil seal stamping outer ring can provide open end or closed end stamping outer ring needle bearing (3 to 5) when the oil seal cannot be installed due to space limitation. These bearings are equipped with friction oil seals of polyurethane or synthetic rubber, which are filled with lithium-based grease with good rust resistance and suitable for operating temperature of -20 to +100 ºC. The inner ring with oil seal bearing is 1mm wider than the outer ring. This makes the bearing work well and avoid the shaft from pollution when the bearing has a slight displacement from the bearing box. The inner ring of the bearing also has lubrication holes, which can be supplemented by the outer ring or inner ring according to the needs of bearing configuration.

Solid ferrule
The solid ring needle roller bearing is composed of one or two ferrules and a needle roller group with cage. According to the application, it can be divided into bearings with or without inner rings. Therefore, the solid ring needle roller bearing can meet the requirements of light weight, small space and high transmission power. The solid ring needle roller bearing has a small volume and high bearing capacity. The structure type outer ring double stop (or double lock ring) with cage needle roller bearing Na, NAV and NKI type can be installed with inner ring and outer ring (with lock ring, complete set of needle roller and cage), with high authority speed, which can be divided into single row and double row. If the shaft cannot be used as a raceway, such needle roller bearings with inner rings can be used if it is impossible or economical to grind the shaft for hardening.

The features of Na and NKI bearings without inner ring are RNA and NK needle roller bearings. The bearing has no inner ring, which is suitable for the bearing structure with limited radial mounting size, and the journal matching the bearing is directly used as the rolling surface. As the roller surface shaft, it is necessary to harden the hardware and grind it. Only when it is processed to the proper size and shape accuracy, the whole set of needle roller bearing can have a high life and operation accuracy. At the same time, due to the absence of inner ring, the diameter of the shaft can be increased appropriately, and the rigidity is increased.

Combination type
The combined needle roller bearing is a bearing unit which is composed of centripetal needle bearing and thrust bearing. It has compact structure, small volume and high rotation precision, which can bear certain axial load while bearing high radial load. And the product structure forms are various, adaptability is wide, easy to install. Combined needle roller bearings are widely used in machine tools, metallurgical machinery, textile machinery and printing machinery and other mechanical equipment, and can make the mechanical system design very compact and agile.

Thrust type
Thrust bearing consists of a thrust cage assembly and a thrust washer with a needle or cylindrical roller or ball. The needle roller and the cylindrical roller are held and guided by the thrust cage. When used with different series of DF thrust bearing washers, many different combinations can be provided for the configuration of bearings. Because the high precision cylindrical roller (needle roller) is selected to increase the contact length, the bearing can obtain high load capacity and high rigidity in a very small space. Another advantage is that if the adjacent parts surface is suitable for the roller surface, the gasket can be omitted, which can make the design compact. The cylindrical surface of the needle roller and the cylindrical roller used by DF thrust needle roller bearing and thrust cylindrical roller bearing is a modified surface, which can reduce the edge stress and improve the service life.

INSTALL


Install full needle roller bearings, usually using auxiliary sleeves. At this time, the auxiliary roller or auxiliary sleeve holds the needle to prevent the needle from falling out. The journal lifts the needle with its own chamfer. With the needle roller bearing moving in the journal, the auxiliary roller or auxiliary sleeve will exit slowly until it is installed in the working position. The outer diameter of auxiliary roller and auxiliary sleeve shall be 0.1-0.3mm smaller than that of shaft. During installation, grease the inner surface of the outer ring of the bearing, and stick the needle against the inner surface (there should be a gap when putting the last needle), then push the auxiliary roller or auxiliary sleeve instead of the journal or bearing inner ring into the outer ring hole, and align the end face with the end face of the mounting shaft or the inner bearing inner ring installed on the shaft, and then use a press or hammer to apply pressure. Needle roller bearing can also be installed in this way. Apply a thin layer of lubricating oil to the outer diameter of the auxiliary sleeve, and insert it into the outer ring of the bearing, so that the auxiliary sleeve and the bearing outer ring form a ring hole, and then install the needle in the ring hole. After the needle roller is installed, push the auxiliary sleeve out with the working shaft. For needle bearing without inner ring or outer ring, during installation, a thin layer of grease can be applied to the rolling surface of shaft or shell hole, and the needle shall be pressed on the grease of installation position in sequence. When sticking the last needle, there should be a gap. The size of the clearance should be 0.5mm on the circumference of the needle roller bearing. The last needle cannot be forced into the machine or one less one, because the bearing will be stuck and cannot rotate when the hard pressing is installed; when the installation is less, the clearance is too large, which makes it easy to make the needle twist and break when the bearing is running. For needle bearing with only stamping outer ring, because the outer ring wall is very thin, needle bearing shall be knocked and installed with hammer, and press in with a press. Because the hammer is hit, the pressure is uneven, which makes the outer ring of needle roller bearing deform locally.

CONTRAST

1. the friction coefficient of rolling bearing is smaller than that of sliding bearing, and the transmission efficiency is high. The friction coefficient of general sliding bearing is 0.08-0.12, but the friction coefficient of rolling bearing is only 0.001-0.005; 
2. rolling bearing has been standardized, serialized and universal, suitable for mass production and supply, and it is very convenient to use and maintain; 
3. rolling bearing is made of bearing steel and heat treated, so rolling bearing has not only high mechanical properties and long service life, The results show that the non-ferrous metals which are expensive to manufacture sliding bearings can be saved. 
4. the inner clearance of rolling bearings is very small, and the processing accuracy of each part is high, so the operation accuracy is high. At the same time, the rigidity of bearing can be increased by preloading. This is very important for precision machinery; 
5. some rolling bearings can bear both radial and axial loads, so the structure of bearing bearing can be simplified; 
6. because of the high transmission efficiency and less heating capacity of rolling bearings, it can reduce the consumption of lubricating oil and save lubrication maintenance; 
7. rolling bearing can be easily applied to any axis in any direction of space.



ATTENTION

Needle bearing has a large bearing capacity, which is suitable for the supporting structure with limited installation size. The surface of journal is hardened as rolling surface. The bearing is pressed into the seat hole with pressing fit, and it is unnecessary to locate it axially. Before the bearing is installed, proper amount of grease shall be injected. Generally, after assembly, BK type bearing is not used for bearing without extended end of journal. The end face sealing plays a sealing role and can bear small axial travel.



CAUSE OF DAMAGE 

Generally speaking, 33.3% of needle bearing damage is caused by fatigue damage, 33.3% of needle roller bearing is due to poor lubrication, and 33.3% is due to improper disposal of pollutants into the bearing or equipment.

The micro dust cleaning bearing and surrounding environment, the invisible fine dust soil is the powerful killer of the bearing, which can increase the wear, vibration and noise of the bearing. When stamping is used, it is very likely to cause needle bearing damage or hammer directly hitting bearing, and transfer pressure through roll body. The influence of non professional tools installation on the application of suitable and accurate equipment can avoid the use of cloth and short fiber. No matter in the laboratory test or in the actual application, needle roller bearing can be seen obviously. The life of needle roller bearing with the same appearance under the same operating conditions has a great difference in its actual life.



DISASSEMBLY METHOD 

Percussion method
The striking force is generally applied to the inner ring of the bearing. The knocking force of the shielding machine room should not be added to the rolling body and cage of the bearing. This method is simple and easy to damage the bearing. When the bearing is located at the end of the shaft, the bearing end is pressed against the shaft end with copper rod or other soft metal materials smaller than the bearing inner diameter. The bearing bearing is equipped with a pad at the lower part of the bearing, and it can be removed by gently knocking with a hammer. The application of this method should pay attention to the proper position of the cushion block and the correct point of the force.

Hot tearing method
Used to remove the bearing for tight fit. First, pour the oil heated to about 100 ºC on the bearing to be removed with oil pot. After the bearing ring is heated and expanded, the bearing can be pulled out with puller.

Push pressure method
Press the bearing with a press, which is stable and reliable, without damaging the machine and bearing shielding machine room. The press has manual push, mechanical or hydraulic press. Note: the press force point should be at the center of the shaft, and it should not be biased.

Pull out method
Special puller is used. When disassembling, the bearing will be pulled out slowly as long as the handle is rotated. When removing the bearing outer ring, the bending angle of the two legs of the puller shall be open outwards; when removing the bearing inner ring, the two legs of the puller shall be inward and stuck on the end face of the bearing inner ring.



ADVANTAGE 

Needle roller bearing is equipped with fine and long rollers (the roller length is 3-10 times of diameter and diameter is not more than 5mm generally). Therefore, the radial structure is compact, its inner diameter and load capacity are the same as other types of bearings, and the outer diameter is the smallest, especially for the supporting structure with limited radial installation size. According to the different use situation, the machining precision and surface quality of needle roller bearing should be combined with the bearing ring and application. Needle bearing is a bearing unit which is composed of centripetal needle bearing and thrust bearing components.

WHY CHOOSE US

1.     Reliable Quality Assurance System
2.     Cutting-Edge Computer-Controlled CNC Machines
3.     Bespoke Solutions from Highly Experienced Specialists 
4.     Customization and OEM Available for Specific Application
5.     Extensive Inventory of Spare Parts and Accessories
6.     Well-Developed Worldwide Marketing Network 
7.     Efficient After-Sale Service System

The 219 sets of advanced automatic production equipment provide guarantees for high product quality. The 167 engineers and technicians with senior professional titles can design and develop products to meet the exact demands of customers, and OEM customizations are also available with us. Our sound global service network can provide customers with timely after-sales technical services.

We are not just a manufacturer and supplier, but also an industry consultant. We work pro-actively with you to offer expert advice and product recommendations in order to end up with a most cost effective product available for your specific application. The clients we serve worldwide range from end users to distributors and OEMs. Our OEM replacements can be substituted wherever necessary and suitable for both repair and new assemblies.