Koyo 72B and 73B series angular contact, 55 x 100 x 21
Available
This Koyo single row angular contact ball bearing (72B and 73B series, 40° contact angle) is designed to carry combined radial and axial load, with the axial load in one direction only. It suits applications that need high accuracy and good high-speed performance. The 40° contact angle gives higher resistance to axial load.
The range has 28 sizes, with bores from 12 to 85mm, boundary dimensions to JIS B 1512 and tolerances to JIS B 1514-1. Koyo bearings are made by JTEKT Corporation.
Where this product is used
- Machine tool spindles
- High frequency motors
- Gas turbines and centrifugal separators
- Front wheels of small size automobiles
- Differential pinion shafts
Features
- Accommodates radial load and axial load in one direction only
- 40° nominal contact angle (suffix B). A larger contact angle gives higher axial load resistance and a smaller one suits high-speed rotation
- Boundary dimensions to JIS B 1512, tolerances to JIS B 1514-1
- Standard cage: pressed steel cage (supplementary code //) or copper alloy machined cage (FY)
- Basic dynamic load ratings 6.95 to 89.2 kN and static 3.4 to 76 kN depending on size (machined cage)
- Allowable misalignment 0.000 6 rad (2 minutes of arc)
Key specifications
| Specification | Detail |
|---|---|
| Bearing type | Single row angular contact ball bearing |
| Series | 72B and 73B series |
| Contact angle (nominal) | 40° |
| Bore diameter d | 12 to 85mm |
| Outside diameter D | 32 to 150mm |
| Width B | 10 to 31mm |
| Basic dynamic load rating Cr (machined cage) | 6.95 to 89.2 kN |
| Basic static load rating C0r (machined cage) | 3.4 to 76 kN |
| Limiting speed, grease lubrication (machined cage) | 3,800 to 20,000 min-1 |
| Limiting speed, oil lubrication (machined cage) | 5,000 to 27,000 min-1 |
| Limiting speed, pressed cage | Under 80% of the machined cage figure |
| Mass | 0.038 to 1.87kg |
| Standard cage | Pressed steel cage (supplementary code //) or copper alloy machined cage (FY) |
| Allowable misalignment | 0.000 6 rad (2 minutes of arc) |
| Dimensions and tolerances | JIS B 1512 (boundary dimensions), JIS B 1514-1 (tolerances) |
| Brand | Koyo (JTEKT) |
Available sizes
| Designation | Bore d (mm) | Outer D (mm) | Width B (mm) | R min (mm) | R1 min (mm) | Cr (kN) | C0r (kN) | Speed, grease (min-1) | Speed, oil (min-1) | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|
| 7201B | 12 | 32 | 10 | 0.6 | 0.3 | 6.95 | 3.4 | 20,000 | 27,000 | 0.038 |
| 7202B | 15 | 35 | 11 | 0.6 | 0.3 | 7.45 | 3.95 | 18,000 | 24,000 | 0.048 |
| 7302B | 15 | 42 | 13 | 1 | 0.6 | to | to | to | to | to |
| 7203B | 17 | 40 | 12 | 0.6 | 0.3 | 9.35 | 5.05 | 16,000 | 21,000 | 0.07 |
| 7303B | 17 | 47 | 14 | 1 | 0.6 | 13.8 | 7.3 | 14,000 | 18,000 | 0.12 |
| 7204B | 20 | 47 | 14 | 1 | 0.6 | 13.3 | 7.7 | 13,000 | 17,000 | 0.112 |
| 7304B | 20 | 52 | 15 | 1.1 | 0.6 | 16.2 | 8.7 | 13,000 | 17,000 | 0.15 |
| 7205B | 25 | 52 | 15 | 1 | 0.6 | 14 | 8.7 | 12,000 | 15,000 | 0.135 |
| 7305B | 25 | 62 | 17 | 1.1 | 0.6 | 22.9 | 13.3 | 10,000 | 14,000 | 0.243 |
| 7206B | 30 | 62 | 16 | 1 | 0.6 | 19.4 | 12.5 | 9,600 | 13,000 | 0.208 |
| 7306B | 30 | 72 | 19 | 1.1 | 0.6 | 27.6 | 17.4 | 8,700 | 12,000 | 0.362 |
| 7207B | 35 | 72 | 17 | 1.1 | 0.6 | 25.6 | 17 | 8,300 | 11,000 | 0.295 |
| 7307B | 35 | 80 | 21 | 1.5 | 1 | 32.5 | 20.2 | 7,700 | 10,000 | 0.475 |
| 7208B | 40 | 80 | 18 | 1.1 | 0.6 | 30.6 | 21.3 | 7,500 | 10,000 | 0.382 |
| 7308B | 40 | 90 | 23 | 1.5 | 1 | 39.7 | 25.2 | 6,900 | 9,200 | 0.657 |
| 7209B | 45 | 85 | 19 | 1.1 | 0.6 | 34.3 | 24.3 | 7,000 | 9,400 | 0.43 |
| 7309B | 45 | 100 | 25 | 1.5 | 1 | 50.6 | 34.1 | 6,200 | 8,200 | 0.875 |
| 7210B | 50 | 90 | 20 | 1.1 | 0.6 | 35.7 | 26.7 | 6,400 | 8,500 | 0.485 |
| 7310B | 50 | 110 | 27 | 2 | 1 | 64.4 | 44.3 | 5,500 | 7,300 | 1.14 |
| 7211B | 55 | 100 | 21 | 1.5 | 1 | 44.1 | 33.8 | 5,700 | 7,600 | 0.635 |
| 7311B | 55 | 120 | 29 | 2 | 1 | 74.3 | 52 | 5,000 | 6,700 | 1.45 |
| 7212B | 60 | 110 | 22 | 1.5 | 1 | 53.4 | 41.6 | 5,100 | 6,900 | 0.82 |
| 7312B | 60 | 130 | 31 | 2.1 | 1.1 | 84.9 | 60.3 | 4,600 | 6,200 | 1.81 |
| 7213B | 65 | 120 | 23 | 1.5 | 1 | 60.9 | 49.3 | 4,800 | 6,400 | 1.02 |
| 7214B | 70 | 125 | 24 | 1.5 | 1 | 63.2 | 50.6 | 4,600 | 6,100 | 1.12 |
| 7215B | 75 | 130 | 25 | 1.5 | 1 | 71.7 | 59.3 | 4,300 | 5,800 | 1.23 |
| 7216B | 80 | 140 | 26 | 2 | 1 | 77.1 | 65 | 4,000 | 5,400 | 1.5 |
| 7217B | 85 | 150 | 28 | 2 | 1 | 89.2 | 76 | 3,800 | 5,000 | 1.87 |
Fitting and use
Check the mounting dimensions in the variant specification: the shaft shoulder diameter da, housing shoulder diameter Da and fillet radius ra give the shoulder sizes and radius limits for the mating parts.
Allowable misalignment of a single row bearing is small, 0.000 6 rad (2 minutes of arc), so align the shaft and housing carefully.
Choosing the right option
Select by bore d first, then check the outside diameter D and width B in the specifications against your housing.
The pressed steel cage values for each size are in the variant specification, and the limiting speed of a pressed cage bearing should be kept under 80% of the machined cage figure.
When a single row bearing is loaded radially, an axial component of force is produced. Use two bearings facing one another, or match two or more bearings, so that the axial load is accommodated.
Static equivalent radial load for a single row bearing is P0r = 0.5 Fr + 0.26 Fa. When P0r is less than Fr, use P0r = Fr.
Angular contact bearings are often preloaded to improve rigidity and running performance. Under too small a load, slip can occur between the balls and raceways and cause smearing.
Also available from Koyo: the 70 series range.
| Option | Part number | SKU |
|---|---|---|
| 12 x 32 x 10 | A0153304 | |
| 15 x 35 x 11 | A0153305 | |
| 15 x 42 x 13 | A0153321 | |
| 17 x 40 x 12 | A0153306 | |
| 17 x 47 x 14 | A0153322 | |
| 20 x 47 x 14 | A0153307 | |
| 20 x 52 x 15 | A0153323 | |
| 25 x 52 x 15 | A0153308 | |
| 25 x 62 x 17 | A0153324 | |
| 30 x 62 x 16 | A0153309 | |
| 30 x 72 x 19 | A0153325 | |
| 35 x 72 x 17 | A0153310 | |
| 35 x 80 x 21 | A0153326 | |
| 40 x 80 x 18 | A0153311 | |
| 40 x 90 x 23 | A0153327 | |
| 45 x 85 x 19 | A0153312 | |
| 45 x 100 x 25 | A0153328 | |
| 50 x 90 x 20 | A0153313 | |
| 50 x 110 x 27 | A0153329 | |
| 55 x 100 x 21 | A0153314 | |
| 55 x 120 x 29 | A0153330 | |
| 60 x 110 x 22 | A0153315 | |
| 60 x 130 x 31 | A0153331 | |
| 65 x 120 x 23 | A0153316 | |
| 70 x 125 x 24 | A0153317 | |
| 75 x 130 x 25 | A0153318 | |
| 80 x 140 x 26 | A0153319 | |
| 85 x 150 x 28 | A0153320 |
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Koyo Single Row Angular Contact Ball Bearing, 40° Contact Angle (B), 72 and 73 Series: 55 x 100 x 21
SKU: A0153314 | Model: 7211B/KOYO
Koyo 7211B single row angular contact ball bearing, 40° contact angle, 55 x 100 x 21mm, Cr 44.1 kN.
