A needle roller bearing is a certain kind of roller bearing that using thin, long, cylindrical rollers that resemble needles and hence the name. While needle bearing conventionally have rollers that are at least four times longer than their diameter, regular roller bearings’ rollers are only a tad bit longer.
When compared to ordinary roller bearings and ball bearings, Needle Bearing has a larger surface area in contact with the races. This further means they can support a much greater load. They are also much thinner, which means they require less space between the axle and surrounding structure.
It usually comes in a cage that orients the needle rollers and outer race, which most of the time houses itself. The bearings are typically found in two separate arrangements. The first being a radial arrangement. In a radial arrangement, the rollers are run parallel to the shaft. And the second being a thrust arrangement. In this, the rollers are placed flat in a radial pattern and are run perpendicular to the shaft.
Types of rolling-element bearing
The majority of rolling-element bearing is either roller or ball bearings. While ball bearings are a single type, roller bearings can further consist of tapered, spherical, and cylindrical and Needle bearings.
This further gives it an advantage over the other types with certain applications, especially those that require to reduce space and weight. Along with that, the higher roller length-to-diameter ratio gives it the name as well as its operating properties. Essentially a Needle Rollers popular because of:
Higher load capacity
Higher load capacity than the single –row ball or roller bearings of comparable characteristics.It can handle a more rigid and larger shaft in any given application.
Usually comes at a lesser cost, especially for drawn-cup types when compared to other machined versions.
Has an amazing rolling characteristic within a small cross-section.
What Are Some Uses of needle bearings?
The bearings are typically used in automotive applications like rocker arm pivots or compressors,transmissions,. For instance, the drive shaft of the rear-wheel driving vehicle uses at least eight needle bearing or more if it operates on steep slopes or is particularly long.
Types of needle bearings
A Needle Roller Bearing can come in different forms, depending on its application and use. Here are some mentioned below:
Airframe needle bearing
(Applications: pivot positions, wing flaps and slats)
(Applications: machine ways, mast rollers, cam followers)
Thrust needle roller
(Applications: automatic transmission in vehicles)
Heavy-duty needle bearings
(Applications: hydraulic pumps, heavy machines, steering gear)
(Applications: constant mesh gears, planetary gears, idler gears and connecting rods)
Drawn cup needle roller bearings
(Applications: pulley supports, gear pumps, gearbox shaft supports, pilot bearings)
If you are planning to get your hands on a needle roller bearing, you should need to know which one you need and why you need it.