RHP7224CTDULP4Angular Contact Ball Bearing – Straight Bore, 120 mm ID, 215 mm OD, 40 mm Width, Open, 15° Contact Angle, Light Preload, Matched Duplex Pair

Product Description

What this part is

RHP 7224CTDULP4 super-precision single-row angular contact ball bearing, supplied as a matched duplex pair. Bore: 120 mm. Outside Diameter: 215 mm. Width: 40 mm. Contact Angle: 15°. Number Of Rows: 1. Bore Type: Straight. Closure Type: Open. Rolling Elements: chrome steel balls. Bearing Material: carbon chrome bearing steel to BS970 534A99 / 535A99, equivalent to SAE 52100, through hardened and stabilised.

Decoding the designation

Series: 7200, ISO dimension series 02. Bore code 24 gives a 120 mm bore. Contact Angle: 15°. Cage Material: laminated phenolic resin. Cage Type: outer-ring guided. Arrangement: DU, a paired unit. Preload: Light. Precision Class: P4. The number is also written 7224-C-T-DUL-P4, B-7224-X2-TA-DUL-EP7, 7224X2 and 7224CTRDULP4.

Load ratings and speeds

Dynamic Load Rating: 199 kN. Static Load Rating: 192 kN. Limiting Speed: 10,100 rpm with oil-air lubrication and 6,400 rpm with grease. The two figures differ because oil-air carries heat out of the bearing and continuously replenishes the film, while grease lubricates without cooling. Mounted as a light-preload back-to-back pair the limiting speed carries a factor of 0.80; face-to-face mounting halves it again.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity, which is what a machine tool spindle wants. Axial Preload: 1,400 N as a light-preload pair. Axial Stiffness: 170 N per micron. Effective Load Centre: 42.4 mm. Lubricant: oil or grease. Maximum Operating Temperature: 120°C, set by the laminated phenolic resin cage. A phenolic cage is light, self-lubricating and quiet, and it runs guided on the outer ring land so the cage is stabilised by the slower-moving ring.

Precision and running accuracy

Precision Class: P4. Precision Rating: ABEC 7, ISO 492 Class 4, BS292 EP7. Deviation of mean bore diameter: 0 to minus 6 microns. Deviation of mean outside diameter: 0 to minus 10 microns. Radial runout of the assembled inner ring: 5 microns maximum. Radial runout of the assembled outer ring: 10 microns maximum. The high point of radial runout is marked by a burnished spot on the inner ring face and by a V line on the outer ring outside diameter, and the V also indicates the direction of the contact angle.

Mounting data

Shaft abutment diameter d1: 132 mm minimum. Housing abutment diameter D1: 203 mm maximum. Outer ring abutment diameter D2: 208 mm maximum. Bearing fillet radius r: 2.5 mm minimum. Inner fillet radius r1: 1.5 mm minimum. Internal Volume: 225.7 cubic centimetres. Lubrication jet pitch circle diameter: 156.3 mm. Mass: 5.426 kg per bearing.

Quantity and configuration

Unit Quantity: 2 Pcs. A universally faced matched duplex pair. Universal face control means the inner and outer rings are the same width and the face relationship is ground at manufacture to give the light preload, so the pair mounts back-to-back or face-to-face at the same preload value and shares load equally in tandem.

Interchange guidance

Cross-references on the same envelope and execution: SKF 7224 CD/P4ADGA, NSK 7224CTRDULP4. Harmonization Code: 8482.10.50.28.