NSK7220CTRDUDMP3Angular Contact Ball Bearing Set, Super Precision — NSK 7220CTRDUDMP3, 100x180x34 mm, 15° Contact Angle, Medium Preload, ABEC 9 / P3, 3 Pcs

Product Description

What this part is

NSK 7220CTRDUDMP3 is a universally ground three-bearing set of single-row super-precision angular contact ball bearings from the 72 series. Bore Diameter: 100 mm. Outside Diameter: 180 mm. Overall Width: 34 mm. Contact Angle: 15°. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. Number Of Rows: Single Row. Bearing Material: Bearing Steel. Series: 72 Series. Base Number: 7220C.

Dynamic Load Rating: 188,000 N per bearing. Static Load Rating: 127,000 N per bearing. Limiting Speed: 8,300 rpm grease; 12,500 rpm oil. Item Weight: 3.18 kg (7.01 lb) per bearing. Load ratings and mass are quoted per bearing, not for the set.

Decoding the designation

7220 — 72 series super-precision angular contact ball bearing on a 100 mm bore, a heavier section than the 70 series at the same bore.

C — 15° contact angle.

TR — phenolic resin cage, outer-ring guided.

DUD — universally ground three-bearing set, two bearings in tandem opposed by a third.

M — medium preload class.

P3 — NSK precision grade equating to ABEC 9 / P3.

What these specs mean in practice

The 72 series carries a thicker cross-section than the 70 series on the same bore, which is why this 100 mm bore bearing reaches a 180 mm outside diameter and a 34 mm width. Precision Class: ABEC 9 / P3. Preload: Medium (M). Cage Material: Phenolic. Cage Type: Outer-ring guided. Lubricant: Grease or oil / oil-air.

A three-bearing set doubles capacity in one axial direction by placing two bearings in tandem while the third takes thrust the other way, a layout used where the cutting or feed load is strongly one-sided. P3 is the tightest accuracy grade NSK catalogues for this size, above P4 and P4Y. Medium preload raises rigidity over the light class in exchange for additional heat generation.

Mounting data

Effective load centre a: 35.7 mm. Permissible axial load Pa: 88.5 kN. Minimum shaft abutment diameter da: 112 mm. Maximum housing abutment diameter Da: 168 mm. Maximum housing abutment diameter Db: 173 mm. Maximum shaft fillet radius ra: 2 mm. Maximum housing fillet radius rb: 1 mm. Minimum chamfer dimension r: 2.1 mm. Minimum chamfer dimension r1: 1.1 mm. Recommended grease quantity: 18 g per bearing. Calculation factor f0: 14.5.

Quantity and configuration

Unit Quantity: 3 Pcs. Mounting Arrangement: Universally ground three-bearing set (DUD).

Interchange guidance

Comparable 100x180x34 mm super-precision 15° angular contact bearings are catalogued by other makers as SKF 7220 CD/P4A, FAG B7220-C-T-P4S, Timken/Fafnir 2MM220WI, RHP 7220CTDU, Koyo 7220C, NTN 7220CG/GNP4 and GMN S 6220 C. Cage style, preload class, accuracy grade and set quantity must be matched code for code before any of these is treated as a drop-in.