RHP7220CTR3ULP4Super-Precision Angular Contact Bearing – 100 mm ID, 180 mm OD, 34 mm Width, Open, 15° Contact Angle, Matched Triple Set

Product Description

What this part is:

RHP 7220CTR3ULP4 super-precision angular contact ball bearing. Bore: 100 mm. Outside diameter: 180 mm. Width: 34 mm per bearing. Series: 7200. Contact angle: 15°. Precision Class: P4 (ABEC 7, RHP EP7). Open on both faces, machined outer-ring-land-riding phenolic cage. Country of origin as recorded on this listing: United Kingdom.

Decoding the designation:

7220 = 72 series, 100 mm bore. C = 15° contact angle. TR = machined phenolic cage, outer-ring guided, rated to 120 °C. 3UL = universally matchable triple set, light preload. P4 = ABEC 7 precision, the RHP EP7 class. Searchable forms of the designation: 7220CTR3ULP4, 7220-C-TR-3UL-P4, 7220 C TR 3UL P4, 7220CTRSULP4 as the single-bearing execution.

What these specs mean in practice:

A 15° contact angle favours speed and radial stiffness over thrust capacity, which is why it is the standard machine-tool spindle angle. The phenolic cage runs light and quiet at high speed and carries oil well, and outer-ring land riding keeps it stable under acceleration. P4 precision holds bore and outer-ring runout tight, giving lower spindle vibration and closer tool location.

Load ratings and speed:

Basic dynamic load rating Cr: 188 kN (42,300 lbf) per bearing. Basic static load rating C0r: 127 kN (28,550 lbf) per bearing. Permissible axial load: 88.5 kN. Limiting speed: 8,300 rpm on grease and 12,500 rpm on oil or oil-air. Effective load centre a: 35.7 mm. Mass: 3.18 kg (7.01 lb) per bearing.

Quantity and configuration:

Three pieces ship, matching the 3UL triple-set designation. The rings are universally ground, so the three bearings can be stacked in tandem or run as a duplex pair plus a third bearing in any arrangement the spindle calls for. Light preload as supplied: 984 N with an axial rigidity of 137 N/µm in a DB or DF pair.

Mounting data:

Shaft abutment diameter da: 112 mm minimum. Housing abutment diameters Da 168 mm and Db 173 mm maximum. Shaft and housing fillet radii ra 2 mm and rb 1 mm maximum. Chamfer dimensions r 2.1 mm and r1 1.1 mm minimum. Preloaded bearings are supplied without a running clearance, so the internal clearance field reads N/A.

Interchange guidance:

Direct equivalents at the same 15° angle, P4 class and light preload: NSK 7220CTRSULP4 in triple set, SKF 7220 CD/P4A, FAG B7220C.T.P4S, Fafnir 2MM220WICR. Related size: 7220A5 shares the 100 x 180 x 34 mm envelope at a 25° contact angle, which raises thrust capacity and lowers speed, so it is not a substitution for a 15° part.