RHP7220TDULP4Super Precision Angular Contact Ball Bearing Duplex Pair – 100 mm ID, 180 mm OD, 34 mm Width, P4, Light Preload, Open

Product Description

What this part is

RHP 7220TDULP4 super precision angular contact ball bearings, supplied as a factory matched duplex pair. Bore: 100 mm. Outside diameter: 180 mm. Width: 34 mm per bearing, 68 mm across the pair. Series: 72, ISO dimension series 02. Single row each, open, straight bore, universally faced. Manufactured in the United Kingdom.

Decoding the designation

Contact Angle: Not specified. Cage: machined laminated phenolic resin, outer ring guided. Grouping: DU, paired unit. Preload: Light. Precision Grade: P4, equivalent to EP7, ABEC 7 and ISO Class 4.

What these specs mean in practice

P4 holds tighter running accuracy than a standard-grade bearing, which lowers runout and vibration in a spindle: inner ring radial runout 5 µm maximum, outer ring radial runout 7.5 µm maximum. The 72 section is the heavy choice at 100 mm bore, 180 mm outside diameter and 34 mm wide, and carries higher load ratings than the 70 section on the same shaft. Light preload gives the lowest internal friction and heat generation of the four preload classes and the highest permissible speed. Preload is set at manufacture, so no internal clearance value applies.

Quantity and configuration

Two pieces, a factory matched duplex pair. Universal face control means the inner and outer rings are the same width and the face steps are pre-adjusted, so the pair mounts back-to-back, face-to-face or in tandem at the marked light preload without ground spacers. The high point of radial runout is marked with a burnished spot on the inner ring face and a V line on the outer ring outside diameter, and the V line also shows the direction of the contact angle.

Fitting notes

Inner ring abutment diameter d1: 112 mm minimum. Outer ring abutment diameters D1 and D2: 168 mm and 173 mm maximum. Fillet radii r and r1: 2.5 mm and 1.5 mm minimum. Lubrication jet pitch circle diameter: 130.6 mm. Internal free volume: 139.2 cm3 per bearing. Recommended shaft fit for P4 at this diameter is a mean interference of 3 µm, and the locating housing fit a mean clearance of 5 µm. Grease fill is 30 per cent of internal volume at low and medium speed, 20 per cent above 60 per cent of maximum speed. Maximum recommended operating temperature: 120 °C. Rings and balls: SAE 52100 through-hardened chrome bearing steel. Mass: 3.173 kg (6.99 lb) each, 6.346 kg (13.99 lb) for the pair.

Interchange guidance

Carton designations: 7220TDULP4, 7220-T-DUL-P4, 7220 T DUL P4, 7220TDUEP7, MM220WICRDUL. In the 72 envelope at 100 mm bore the 15° executions are SKF 7220 CD/P4ADGA, FAG B7220-C-T-P4S-DUL, Fafnir 2MM220WI-DUL and NSK 7220CTRDULP4; the 25° executions are SKF 7220 ACD/P4ADGA, FAG B7220-E-T-P4S-DUL, Fafnir 3MM220WI-DUL and NSK 7220A5TRDULP4.