The design of four-row tapered roller bearings is particularly suited for taking extreme combined (radial and axial) loads at low to medium speeds. The axial load capacity depends primarily on the contact angle. The greater the angle, the greater axial load capacity. The four-row design ensures optimal load distribution between all four rows of rolling elements.
For highly contaminated operations with insufficient lubrication, sealed four-row tapered roller bearings are recommended. They have a very long service life even with an extremely high load capacity.
NSK produces four-row tapered roller bearings in various special materials for rolling mills, such as Water-TF and Super-TF, combined with NSK Sealed-Clean technology.
These materials increase the bearing life several times and increase reliability in extremely demanding conditions, thus preventing unexpected accidents. They reduce maintenance costs by more than 50% of those with conventional bearings.
KVS Series – Sealed four-row tapered roller bearings made of STF/WTF steel. Extreme load capacity, long service life, high durability and reliability, especially for rolling mills.
Special resistant bearing steels:
STF steel (Super-TF)
Specially developed steel for high-load bearings with higher austenite content and special heat treatment. It has a very fine structure. This combination provides greater durability in dirty environments with insufficient lubrication.
Super-TF steel provides a significantly longer service life under heavily contaminated operating conditions. Extending the service life by five times the usual amount or doubling it when grease is less contaminated.
WTF steel (Water-TF)
Super-clean bearing steel developed specially for rolling mills. Advantageous under harsh operating conditions. This material provides higher reliability and longer operating life due to prevention of flaking stage and cracks caused by water infiltration.
Bearing series: KV, KVS (těsněná) – značení WTF…KVS…; STF…KVS…