NIS Brg units

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Introduction NIS bearing units

A typical ball bearing unit consists of a double sealed, single row bearing and one of the various housings of cast iron or pressed steel.

Bearing Unit Structure

The outer ring of the self-contained ball bearing is ground to a sphere and the bore of the housing is machined to a matching radius. This permits self-alignment between the two members. Above figure is a view of a pillow block which is the most popular type of insert ball bearing unit with set screw locking. Bearing units have various types of sealing options and can operate satisfactorily under hard working conditions, especially for machines operating in dusty or muddy surroundings. They are thus, widely used in agricultural, construction, foodstuff  and conveying machinery.

NIS Bearing unit features

Efficient sealing
Three types of sealing methods are available for use in various operating conditions.

RS+Slinger : A pressed metal shield is fixed to the inner ring of the bearing unit and a rubber seal is attached onto the outer ring. The pressed metal shield acts as a "slinger" ejecting contaminants upon contact. The rubber seal forms standard sealing torque. Working in combination with the rubber seal it forms an effective barrier against entrance of foreign matter such as dust, mud, vapour and prevention of grease leakage to keep the bearing in good operating condition.

Triple lip seal : A metal shield with long triple rubber lips provide high sealing torque and forms good sealing against wet environments. It is especially suitable for agricultural machinery operating at poor environmental conditions.

RST type : Covers the functions of both shield and seal. The rubber lip and inner ring form a standard torque contact sealing. It will provide an effective barrier against contaminants. 

Solid housing
All NIS bearing unit housings are made from solid "one-piece construction" cast iron to provide maximum rigidity against deformation at mounting and wear resistance at any operating conditions.

Shaft locking mechanisms
NIS bearing units can be locked onto the machine shaft by three methods. Locking by set screws, eccentric collar and adapter sleeve methods are available. All methods employed ensure easy and secure locking of the bearing to the shaft. Most popular method is by set screw locking.

Special heat treatment on bearing inner ring
The inner ring of the self-contained bearing is hardened on the raceways and surroundings. For NIS bearings the set screw hole area is also hardened and tempered, imparting high hardness and impact resistance. This additional heat treatment ensures full bearing performance and prevents the set screws from loosening during operation as the set screw can be tightened enough without causing the screw threads on the set screw hole to shear off.
Anti-rotation device
NIS bearings come equipped with a unique locking pin (or ball) which prevents the bearing outer ring from rotating without interference to the self-alignment of the bearing. This improvement is capable of extending bearing life.


Complete interchangeability
Skilled precision workmanship on the self-contained bearing and the housing provides complete interchangeability between bearing and housing, thus allowing quick and simple replacements when required.

Easy installation
All NIS bearings come pre-lubricated with sufficient quantity of high quality grease, individual seal and packed. These bearings are ready for installation. 




Last modified : 30 October 2002

Motion Bearings Pte. Ltd.
131 Kaki Bukit Ave 1, Shun Li Industrial Park, Singapore 416000.
Tel : +65-6844 5411       Fax : +65-6844 2377