WD cylindrical roller bearings have many designs, dimension series and sizes. The majority is single row bearings with a cage. Single and double row full complement bearings (without cage) complete the WD standard assortment for general engineering. Bearings with a cage can accommodate heavy radial loads and operate at high speeds. Full complement cylindrical roller bearings are suitable for very heavy radial loads at moderate speeds.

The rollers of WD cylindrical roller bearings are key components. Their geometry, the so-called logarithmic profile, provides an optimum stress distribution in the contact zones in the bearing. Their surface finish maximizes lubricant film formation and optimizes rolling motion of the rollers. The benefits derived from this compared with traditional designs include enhanced operational reliability and a greater insensitivity to misalignment.

The range of WD cylindrical roller bearings comprises the basic types.
WD single row cylindrical roller bearings, caged, mainly of the NU, NJ, NUP and N designs.
WD double row cylindrical roller bearings, caged, mainly of the NNUand NN designs.
WD single row full complement cylindrical roller bearings, mainly of the NCF and NJG designs.
WD double row full complement cylindrical roller bearings, mainly of the NNF design.

WD cylindrical roll bearings have the following design features:

1. Optimized design in ribs and rollers to enhance the axial load capacity.
2. Optimized design in the geometric surface between rollers and raceway to balance the radial load distribution.
3. Limit the width of raceway undercut, increase the contact area between raceway and rollers and enhance the radial load capacity.
4. High standard material, strictly control the element content, e.g. Ti<30ppm.
5. Low noise design, reaches to V1 grade noise level, contributes to the quieter running of automobile engine and gearbox.
 
Cages

Depending on the bearing series, size and designs, cylindrical roller bearings are fitted as standard with one of the following cages.

TVP2
an injection moulded window-type cage of glass fibre reinforced polyamide 66
F1
a pressed window-type cage of unhardened steel
ME
a one -piece machined window-type brass cage

M

a two-piece machined brass cage

Note
WD single row cylindrical roller bearings with polyamide 66 cages can be operated at temperatures up to +120℃. The lubricants generally used for rolling bearings do not have a detrimental effect on cage properties, with the exception for a few synthetic oils and greases with synthetic base oil as well as some lubricants containing a high proportion of EP additives when used at elevated temperatures.
For bearing arrangements of continuous high temperatures or under tough conditions, the use of bearings with a metallic cage is recommended. For applications in equipment using refrigerants such as ammonia or freon replacements, bearings with a polymide cage can be used for operating temperatures up to 70℃. At higher operating temperatures bearings with machined brass or steel cage should be used.
 
Radial internal clearance
WD single row cylindrical roller bearings are manufactured with normal radial internal clearance as standard and most of the bearings are also available with C3 radial internal clearance. Some of the bearings can even be supplied with the smaller C2 or the greater C4 clearance. In addition, some bearings are produced with special reduced clearances. This special clearance corresponds to a section of a standard clearance range or two adjacent clearance ranges.
Bearings with non-standard clearance or special reduced clearances can be supplied to special order.
The actual clearance limits for bearings with a cylindrical bore and a tapered bore are in accordance with ISO 5753:1991. They are valid for unmounted bearings under zero measuring load.
The separable components of all bearings with standard clearance as well as those with reduced clearance are interchangeable...MORE>>

Axial internal clearance
NUP-design cylindrical roller bearings, which can locate a shaft axially in both directions, are manufactured with an axial internal clearance as shown in table 3. The axial internal clearance of NJ-design bearings when combined with an HJ angle ring is specified in table 4.
The clearance limits quoted in tables 3 and 4 should be considered as guideline values. When axial internal clearance is measured, the rollers may tile, causing an enlargement of the axial clearance, which may be as much as...MORE>>



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