Grinding process Lapping process KOYO NN3014 Double Row Cylindrical Roller Bearings

Double row cylindrical roller bearing

Double row cylindrical roller bearings: common models are NN, NNU, NNC, NNCF, NNCL and NNF. These bearings are characterized by double guards in the inner ring or double guards in the outer ring, which does not limit the relative axial displacement between the shaft and the housing, and is suitable for occasions where a large radial load is required and there is no strict requirement for axial displacement.

Double row cylindrical roller bearings can withstand higher radial loads because they have two rows of rollers.

Double-row cylindrical roller bearings such as NN type and NNU type, due to the inner and outer ring guard design, do not limit the relative axial displacement between the shaft and the housing, suitable for the need to bear a large radial load.

Double row cylindrical roller bearings can be separated for easy installation and disassembly, which is very useful for occasions where frequent maintenance or replacement of bearings is required.

Installation Method and Usage Precautions of Double Row Cylindrical Roller Bearing                          

Bearing precautions and installation methods

Compared with general mechanical parts, bearings have very high manufacturing precision and have certain requirements for installation and use. 

If you do not pay great attention, it will cause damage to the bearings, and the normal service life of the bearings will not be obtained, 

and it will also cause damage to related parts. of damage. 

Generally speaking, accidents caused by bearings are caused by improper installation and irregular use. 

Therefore, if they can be installed and used in the correct way, the service life of the bearings can be improved.

Things to pay attention to when working

When installing bearings, the most important thing is to keep the bearings and related parts clean and to use installation tools and methods correctly. 

Therefore, it is important to observe the following precautions:

1. Clean the working area and use clean tools or auxiliary tools for work.

2. When installing, you should use auxiliary tools with good plasticity and not easy to fall off.

3. Confirm that all assembled parts are qualified.

4. The bearing cannot be unsealed until it is used.

5. Keep the bearings clean during operation.

6. Under normal circumstances, the anti-rust oil does not need to be washed away. It can be installed in its original state. 

If it is necessary to install lubricating grease, use gasoline to clean the grease on the bearing, and then blow it clean with an air gun.

Bearing installation - inspection work before installation

Things to note before installing bearings:

1.  Are the dimensions of the shaft and bearing body processed according to the drawing requirements? 

Are there any protrusions at the corners and right angles of the shaft, bearing body, and can they fully contact the end face of the bearing? 

All must be fully inspected.

2.  It should be determined whether there are bruises, bulges, etc. on the mating surfaces of the shaft and bearing body. 

There is dust or molding sand attached to the surface of the bearing shell. If there is, use a whetstone, fine sandpaper or a clean rag to remove it.

3.  In order to avoid bruises during installation, a small amount of lubricating oil should be applied to the working surfaces of the shaft and bearing body.

4. Bearing installation - force application surface and force application method. When the bearing is installed on the shaft, force must be applied on the inner ring. 

When installed on the bearing body, force must be applied on the outer ring. Note: Do not knock the outer ring when the bearing is installed on the shaft. 

Do not knock the inner ring when it is installed on the bearing body. 

Such operations will inevitably cause scratches on the bearing track surface, causing noise and early termination of failure, affecting the bearing life. 

When applying force to the bearing, be sure to make the force vertical and even downwards. 

If the force is applied off-center, the bearing will be damaged. Therefore, definitely avoid missing shots. 

In addition, do not apply force to the bearing cage and sealing plate.

5.  Installation of bearings - Installation using a hammer and casing. The installation method of using a hammer and casing is a commonly used method. 

It must be as shown in the picture, so that the sleeve is in the middle and knocked in. The hammer should be tapped gently. .

6. Bearing installation - When the inner and outer rings are installed at the same time, in terms of the mechanical structure, 

when the inner and outer rings are tightly fitted, a backing plate should be used, 

and the force must be applied to the inner and outer rings at the same time to knock them in. 

If external force is applied only to the inner ring, the force will be pressed into the outer ring through the balls, thus causing scratches on the track surface.

7. Assembly summary of rolling bearings 

      --All dirt on the bearings must be cleaned before assembly. 

      --When installing the bearing on the shaft, the pressure of pressing the bearing should be on the inner ring.

        When installing the bearing into the bearing body or suspension (bracket), the pressure should be applied on the outer ring. 

     --When pressing or driving in with a copper rod, the pressing force and impact force should be evenly distributed on the entire end surface of the inner 

        and outer rings of the bearing, and no force should be applied to the cage or beads. At the same time, 

        The hammer should not be used to directly hit the bearing end face to avoid bruising or damaging the bearing. 

     --When installing bearings, attention must be paid to the surrounding environment to prevent dust and dirt from entering the bearings. 

        After installing the bearing, the installed bearing should be protected (sealed) immediately. 

     --After the bearing is tightened, the rotational flexibility of the rolling bearing must be checked. 

     --Although the fit between the rolling bearing and the shaft or bearing seat is an interference or transition fit, considering the structure 

       and bonding strength of the parts,heating or cooling methods must be used for assembly. Generally (SKF) heating should not exceed 110°C.

Knowledge and Introduction of Double Row Cylindrical Roller Bearing                 

Product Specifications:

• Brand: KOYO

• Model Number: NN3014

• Inner Diameter (d): 70 mm

• Outer Diameter (D): 110 mm

• Width (B): 30 mm

• Type: Cylindrical Roller Bearings, double row

• Dynamic Load Rating (Cr): Not specified in the provided data

• Static Load Rating (C0r): Not specified in the provided data

• Limiting Speeds: Not specified in the provided data

• Mass: Not specified in the provided data

Technical Features:

• The KOYO NN3014 bearing is a double row cylindrical roller bearing designed for high radial load capacity and precision.

  These bearings are known for their compact design, high rigidity, and excellent performance under load

• The bearing features a cylindrical bore and is constructed with a material of hardened alloy steel.

  The cage is made of high-strength, two-piece, machined brass

• The NN3014 bearing can accommodate axial displacement in both directions due to its design with three flanges on the inner ring

  and no flanges on the outer ring. This design also simplifies mounting and dismounting, particularly when both rings require an interference fit

• The bearing is capable of minimizing noise, vibration, and heat generation, which contributes to lower mechanical energy consumption and wear,

  as well as a longer service life

Applications:

KOYO NN3014 bearings are commonly used in a variety of industrial applications, including machine tool spindles, high-speed rotating equipment, and precision machinery where high radial load capacity, precision, and reliability are critical

Additional Information:The KOYO NN3014 bearing is also available with supplementary lubrication structures,

such as a lubrication groove and holes, which facilitate maintenance and contribute to the longevity of the bearing.

This KOYO NN3014 bearing is a high-performance component designed for applications demanding high radial load capacity, precision,

and speed, making it a reliable choice for various industrial and precision equipment.

For further details on this product please directly contact our sales department under shh@dmsw.com

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