Bearing needle

A needle roller bearing is a type of bearing in which needle rollers act as rolling elements. These rollers have a very thin and long shape, which allows for a high load capacity with small bearing dimensions.

Main characteristics and features

Needle roller bearings have the shape of very thin cylindrical elements, which allows for high load capacity with compact dimensions.
These bearings do not have an inner ring, so outer rings are often used to support the rollers.

Advantages

- high load capacity with small dimensions;
- well suited for transmitting torque in narrow spaces;
- can operate at high speeds due to their low friction coefficient.

Types of needle roller bearings

- single-row (used in systems with low radial load, in narrow spaces to ensure high load capacity with limited dimensions (in automotive transmissions, in electric motors, in cardan shaft bearings, in transmission mechanisms);
- double-row bearings (increase load capacity and reduce pressure on each roller, can withstand both radial and axial loads; used in mechanisms where it is necessary to simultaneously reduce the size and increase strength (in gearboxes, automotive systems, machine tools);
- needle roller bearings without a ring (there is no outer ring, and the rollers run directly in a metal channel on the housing, which reduces the weight and size of the bearing, but requires high precision in surface treatment; they are used where it is not possible to use an outer ring (in confined spaces of engines or in certain systems of automated machines));
- needle roller bearings with roller retainers (the rollers are fixed with special elements (removable inserts or pads), which prevents their displacement; they are used in conditions where there is a risk of roller movement under high loads (in drive mechanisms or in industrial units))
- needle roller bearings with full rolling (use thicker rollers that fill the entire space between the bearing rings, which minimizes friction; used in highly loaded mechanisms where a minimum level of friction is required (in some industrial machines or transmissions));
- needle roller bearings without fixation (the rollers are not fixed in any way, which allows them to rotate freely between the bearing rings; they are used where rigid fixation of the rollers is not required (in mechanisms where high rotation accuracy is required)).

Each type of needle roller bearing has its own characteristics, depending on the operating conditions and requirements for the design of the mechanism. The choice of a particular type depends on the required loads, rotational speeds, and the available space in a particular mechanism.

Areas of application

Due to their advantages, needle roller bearings are widely used in industries that require compactness, high loads and reliability.
In particular, they are often used in the automotive industry (in transmissions, gearboxes), as well as in various industrial installations where compact dimensions and high reliability are important.

Main types of needle roller bearings and their designations

NA - without inner ring
NK - with flange
NKI - with flange, without inner ring
RNA - without inner ring, with increased strength
AXK - with axial flange
NKS - with cage
RLS - with welded body
HK - with cage (for holding rollers).
IR - with inner ring
K - with inner ring and flange.

Designations may vary from manufacturer to manufacturer, but most follow ISO or similar international standards.

On the ebearing.com.ua website you can buy needle roller bearings from well-known manufacturers NTN, SKF, INA, JNS, Koyo, CX, FBJ, CT...