RHP7018CTSULP4Super Precision Angular Contact Ball Bearing 90x140x24 mm 15° ABEC 7 Light Preload

Product Description

What this part is

RHP 7018CTSULP4 single-row super-precision angular contact ball bearing. Bore: 90 mm. Outside Diameter: 140 mm. Overall Width: 24 mm. Contact Angle: 15°. Precision Class: P4, ISO Class 4, ABEC 7, RHP class code EP7. Cage Material: laminated phenolic resin. Cage Type: machined, outer-ring guided. Closure Type: open on both faces. Rolling Elements: carbon chrome bearing steel balls. Series: RHP 70, ISO dimension series 10. Number Of Rows: 1.

Decoding the designation

Type 7: single-row angular contact ball bearing. Dimension series 0: ISO series 10. Bore code 18: 90 mm bore. Contact angle C: 15°. Cage T: laminated phenolic resin, outer ring guided. Grouping SU: single universal. Preload L: light. Precision grade P4: ISO Class 4, ABEC 7, British Standard EP7. The carton also carries B7018X2TAULEP7, in which X2 is 15° and EP7 is ABEC 7, and the Fafnir-scheme number 2MM9118WI-CR-SUL, in which 2MM is 15° and CR is a phenolic outer-land-riding cage.

Load ratings and speed

Dynamic Load Rating (Cr): 71.5 kN. Static Load Rating (C0r): 69.0 kN. Limiting Speed, oil/air lubrication: 14,600 rev/min. Limiting Speed, grease lubrication: 8,700 rev/min. Those figures apply to a single bearing under a spring preload with the inner ring rotating. A back-to-back light-preload pair takes a 0.80 speed factor, a set of three 0.65 and a set of four 0.60. A face-to-face arrangement takes a further 50 per cent reduction. A spring-loaded tandem pair takes 0.95.

What these specs mean in practice

A 15° contact angle is the speed-biased choice at this size. The shallow load line keeps ball centrifugal and gyroscopic effects low, so the bearing reaches a higher limiting speed and runs cooler than a 25° execution on the same envelope, in exchange for axial capacity and axial stiffness. At a 90 mm bore, where ball-track surface speed is already high, that trade carries more weight than it does on a small bearing.

Light preload is the low-heat end of the preload scale. Axial Preload, light grade, as a paired set: 490 N. Axial Stiffness, light grade, as a paired set: 117 N per micrometre. Preload removes internal play, fixes the contact angle and makes axial position and runout repeatable. The bearing is preload-set at manufacture rather than clearance-set.

The laminated phenolic resin cage riding on the outer ring land is the high-speed cage arrangement. Phenolic is light, so cage inertia and ball-pocket loads stay low, and it holds an oil film well. Land guidance keeps the cage running true at speed. Maximum Operating Temperature: 120 °C, set by the phenolic.

Quantity and configuration

Unit Quantity: 1 Pc. Arrangement: single universal (SU). Universal face control means the inner and outer rings are the same width and the face positions are adjusted at manufacture, so two pieces of this designation mount back-to-back or face-to-face at the same preload value with no measured spacers. Mounted in tandem they share load equally.

Thrust direction

A single-row angular contact ball bearing carries thrust in one direction. Axial load in the opposite direction is taken by a second bearing opposing this one, or by another element in the shaft stack.

Mounting data

Inner ring abutment diameter, d1 min: 99 mm. Outer ring abutment diameters: D1 max 131 mm, D2 max 134 mm. Chamfer dimensions: r min 1.5 mm, r1 min 1.0 mm. Effective Load Centre (a): 27.4 mm. Internal free volume: 49.3 cm³. PCD of lubrication jets: 108.6 mm. Mass: 1.161 kg. Radial runout of the assembled inner ring, Kia: 5 µm. Radial runout of the assembled outer ring, Kea: 7 µm.

Interchange guidance

NSK 7018CTRSULP4 is the current NSK-RHP catalogue designation for this bearing. SKF 7018 CDGA/P4A and FAG B7018-C-T-P4S-UL are the equivalent 15° universally matchable light-preload executions on the same envelope. Same-envelope bearings differing in contact angle, preload grade or tolerance class — 7018A5 at 25°, the medium and heavy preload grades, and P0 or P3 class pieces — are related sizes rather than interchanges.