INARNA NA 4902 RSR 2RSR XLNeedle Roller Bearing – 20 mm Under-Roller Diameter, 28 mm OD, 13 mm Width, Contact Seals Both Sides

Product Description

What this part is

INA RNA4902-2RSR-XL needle roller bearing, single row, sealed on both sides. The bearing is a machined outer ring with a needle roller and cage assembly; the shaft itself forms the inner raceway. Under-Roller Diameter (Fw): 20 mm. Outside Diameter: 28 mm. Width: 13 mm. Dynamic Load Rating: 9,700 N. Static Load Rating: 10,300 N. Fatigue Load Limit: 2,070 N. Limiting Speed: 12,600 rpm. Weight: 19.5 g. Minimum Chamfer Dimension: 0.3 mm. Operating Temperature: –20 °C to 100 °C. Number Of Rows: 1. Rolling Elements: needle rollers. Closure Type: contact lip seals both sides. Design Units: Metric.

Decoding the designation

RNA — needle roller bearing supplied as a machined outer ring plus roller-and-cage assembly, to DIN 617 / ISO 1206, running on a hardened and ground shaft raceway.

49 — the dimension series, which sets the 28 mm outside diameter and 13 mm width over a 20 mm roller circle.

02 — the size code inside that series.

2RSR — contact lip seals on both sides.

XL — Schaeffler’s optimised execution, carrying the load ratings quoted above on the standard envelope.

What these specs mean in practice

Needle rollers put a long line contact into a very short radial section, so this bearing carries 9,700 N dynamically inside a 4 mm wall between the shaft and the housing bore. Running the rollers straight on the shaft removes an inner ring and takes the section thinner still, which is why needle bearings appear in gearboxes, pumps, linkages and planetary gear pins where radial room is the constraint.

The contact lip seals hold grease at the roller set and keep swarf and washdown out, at the cost of a little running torque against an open execution. Limiting Speed: 12,600 rpm applies to grease lubrication.

Static Load Rating: 10,300 N is the ceiling for shock and for stationary load; Dynamic Load Rating: 9,700 N governs rotating life. Fatigue Load Limit: 2,070 N is the load below which fatigue life is effectively unlimited.

Quantity and configuration

Unit Quantity: 1 Pc.

Mounting data

The shaft seat is hardened and ground to 20 mm and forms the inner raceway. Housing bore 28 mm. Minimum Chamfer Dimension: 0.3 mm at both ring corners. Where a shaft cannot be hardened, the NA4902-2RSR-XL execution of the same size adds an inner ring and runs on a soft shaft at a 15 mm bore.

Interchange guidance

The open equivalent on the same envelope is the RNA4902-XL; the single-seal execution is the RNA4907-RSR-XL pattern, RNA4902-RSR-XL in this size. Bearing Material: chrome steel. Cross-references on the same 20 x 28 x 13 mm envelope carry the ISO designation RNA4902 across makers; check the seal code before substituting, since an open or single-seal part changes the closure and the running torque.