IKO NA4904UU Needle Roller Bearing with Inner Ring, Seals Both Sides, 20 x 37 x 17 mm

IKO NA49 UU needle roller bearings are machined type caged bearings with an inner ring and seals on both sides (UU). This page lists 21 sizes: 10 to 95 mm bore, 22 to 130 mm outside diameter and 13 to 35 mm wide. NA49 is dimension series 49.

Machined type needle roller bearings have a low sectional height and large load ratings. The outer ring is rigid and can be used even in light alloy housings. Both sides carry seals made of special synthetic rubber, which keep dust out and hold the grease in, and the bearing is supplied prepacked with grease.

The inner ring lets the bearing run on a shaft that cannot be heat-treated and ground. The sealed type uses an LRTZ inner ring, shown against each size below.

Where this product is used

• Shafts that cannot be heat-treated and ground
• Positions where dust may reach the bearing
• Compact shaft supports with a low sectional height

Features

• Machined type caged needle roller bearing with inner ring and seals on both sides (NA49 series, UU), 21 sizes
• Bore 10 to 95 mm, outside diameter 22 to 130 mm
• Matching inner ring shown for each size, for shafts that cannot be heat-treated and ground
• Seals on both sides (UU), special synthetic rubber, supplied prepacked with grease
• Basic dynamic load ratings 8.08 to 109 kN, static 8.49 to 250 kN
• Allowable rotational speed 1,700 to 14,000 rpm (grease lubrication)

Key specifications

Available sizes

d is the bore, D the outside diameter, C the outer ring width and Fw the roller set bore diameter; C and C0 are the basic dynamic and static load ratings, and speed is the allowable rotational speed for grease lubrication.

Selecting the right option

Choose the size with the Outside Diameter option. The model number is shown with each variant, and the sizes table gives the bore, outside diameter and width for each.

The UU in the model number means seals on both sides. The open version of the series has no UU and is on the NA49 and NA48 page.

Bearings with an inner ring suit shafts that cannot be heat-treated and ground. If your shaft is hardened and ground, the sealed type without an inner ring is on the RNA UU page.

The assembled inner ring is shown against each size in the sizes table. The bearing and its inner ring are listed as separate parts, so request a quote to confirm what is supplied if you need both together.

Fitting and use

These bearings are supplied prepacked with grease. The allowable rotational speed in the tables applies to grease lubrication. The outer ring has one oil hole with an oil groove, and the inner ring has no oil hole.

Ask AIMS for the shaft and housing tolerances that suit your application.

Related products

Parts that go with this range: NA69 UU: the wider NA69 series with seals; RNA UU: sealed, without an inner ring; LRTZ inner rings for the sealed type.