RHPSuper Precision Angular Contact Ball Bearing 35 x 55 x 10 mm 15 Degree Phenolic Cage Light Preload

Product Description

What this part is

A single-row super-precision angular contact ball bearing in the thin ISO 19 section. Bore: 35 mm. Outside Diameter: 55 mm. Width: 10 mm. Contact Angle: 15°. Cage Material: Laminated phenolic resin. Cage Type: Machined, outer ring guided. Preload: Light (L). Precision Class: P4 (ISO Class 4, ABEC 7). Bearing Class: P4 (ISO Class 4). Seal Type: Open. Closure Type: Open, no seal or shield. Bore Type: Straight. Number of Rows: 1. Rolling Elements: Steel balls. Bearing Material: Carbon chrome bearing steel to BS970 534A99/535A99 or SAE 52100. Design Units: Metric.

Decoding the designation

In the RHP super-precision scheme 7 is a single-row angular contact ball bearing, 9 is ISO dimension series 19, bore code 07 is a 35 mm bore, C is a 15° contact angle, T is a machined laminated phenolic cage, SU is universal face control, L is light preload and P4 is ISO Class 4. The ISO base number for the same envelope is 71907, and the RHP B-series carton form is B7907X2TAULEP7.

Published ratings

Dynamic Load Rating (Cr): 12,100 N. Static Load Rating (C0r): 9,150 N. Limiting Speed: 39,900 rpm oil/air; 24,700 rpm grease. Axial Preload, light class, as a paired set: 69 N. Axial Stiffness, light class, as a paired set: 39 N/µm. Lubricant: Oil/air or grease. Maximum Operating Temperature: 120 °C, set by the laminated phenolic cage. Mass: 0.074 kg (0.163 lb). Radial runout of the assembled inner ring, Kia: 4 µm. Radial runout of the assembled outer ring, Kea: 5 µm.

What these specs mean in practice

A 15° contact angle is the speed-biased end of the angular contact range, giving the highest limiting speed of the standard angles, which is why grinding and high-frequency spindles use it. The laminated phenolic cage runs on the outer ring land, weighs little and holds an oil film, suiting oil-mist and oil/air lubrication. Light preload adds the least friction heat of the four standard grades while fixing the contact angle and making axial position repeatable; the bearing is preload-set at manufacture rather than clearance-set. P4 holds the assembled inner ring radial runout to 4 µm and the assembled outer ring radial runout to 5 µm, so stacked bearings share load evenly. The tabulated limiting speeds are single-bearing figures under spring preload with the inner ring rotating; a back-to-back pair at light preload takes a 0.80 speed factor, a set of three 0.65 and a set of four 0.60, face-to-face mounting takes a further 50 per cent reduction, and a spring-loaded tandem pair takes 0.95.

Quantity and configuration

Unit Quantity: 1 Pc. Arrangement: Single universal (SU), open on both faces. Universal facing means two pieces of this designation reach the specified light preload as ground, back-to-back, face-to-face or in tandem.

Mounting data

Inner ring abutment diameter d1: 40 mm minimum. Outer ring abutment diameter D1: 50 mm maximum. Outer ring seat diameter D2: 52.5 mm maximum. Fillet radius r: 0.6 mm minimum. Fillet radius r1: 0.3 mm minimum. Effective Load Centre a: 11.0 mm. Internal free volume: 3.6 cm³. PCD of lubrication jets: 42.6 mm.

Interchange guidance

71907 is the ISO base designation for this envelope, NSK 7907CTRSULP4 the current NSK-scheme number, B7907X2TAULEP7 the RHP B-series carton form, and 2MM9307WI CR the Fafnir-scheme number for the same 719-series size. A 7907A5 shares the 35 x 55 x 10 mm envelope at a 25° contact angle, with its own stiffness and speed figures. Medium and heavy preload grades are separate parts.