INANA4911-XLMachined Needle Roller Bearing with Inner Ring — 55 mm ID, 80 mm OD, 25 mm Width, Open, Single Row, X-life

Product Description

What this part is: INA NA4911-XL, a single-row machined needle roller bearing supplied with its own inner ring. Bore: 55 mm. Outside Diameter: 80 mm. Width: 25 mm. Rolling Elements: needle rollers. Closure Type: open. Number Of Rows: 1. Dynamic Load Rating: 65 kN. Static Load Rating: 100 kN. Fatigue Limit Load: 17.3 kN. Limiting Speed: 7,200 rpm. Design: X-life. GTIN: 4012802195545. Decoding the designation: NA — machined needle roller bearing supplied complete with an inner ring, so it runs on a plain unhardened shaft. The same bearing without the inner ring is an RNA4911. 49 — dimension series 49, the standard-section needle series, which sets the 80 mm outside diameter against the 55 mm bore. 11 — the bore code, 11 x 5 = 55 mm. XL — X-life execution, INA’s upgraded internal geometry and surface finish rating. What these specs mean in practice: Dynamic Load Rating: 65 kN. Static Load Rating: 100 kN. On a needle roller bearing the static figure sitting above the dynamic figure is the normal published relationship — the line contact of a full needle complement spreads a stationary load over far more raceway area than a ball bearing does. Fatigue Limit Load: 17.3 kN, the load below which raceway fatigue does not initiate. The whole 65 kN comes out of a 12.5 mm radial wall, which is the reason a needle bearing is chosen: it carries roller-bearing loads in roughly the radial space a ball bearing would need for half of it. Limiting Speed: 7,200 rpm. The inner ring is separable, so shaft and housing can be dressed and measured independently and the bearing does not depend on a hardened and ground shaft journal. Mounting data: Bore: 55 mm on the supplied inner ring. Outside Diameter: 80 mm. Width: 25 mm across both rings. The outer ring locates in a plain housing bore; the inner ring is a press fit on the shaft and is fitted separately from the outer ring and needle assembly. Quantity and configuration: Unit Quantity: 1 Pc. One bearing comprises the machined outer ring, the caged needle complement and the separable inner ring. Supplied loose, as it came in mill sleeves of five. Interchange guidance: Manufacturer part number variants: NA4911-XL, NA4911XL, NA-4911-XL, NA 49/11 XL, NA4911. The designation is an ISO-standard needle bearing envelope, so IKO, SKF, NTN, Koyo and Nachi NA4911 parts share the 55 x 80 x 25 mm boundary dimensions. An RNA4911 is the same outer ring and needle assembly running directly on a hardened shaft, so it is a related part rather than a drop-in for this one.