Cylindrical Roller Bearings: Top China Suppliers & Factory for Single-Row, Double-Row, and Four-Row Solutions
Single-Row Cylindrical Roller Bearings
These provide unidirectional axial positioning of the shaft.
Double-Row Cylindrical Roller Bearings
Double-row cylindrical roller bearings are manufactured as precision-grade bearings for machine tool spindles and can also be used in other precision machinery.
Dimensions
The basic dimensions of the bearings listed in the tables comply with ISO 15:1981.
Permitted Tilt Angle
Proper adjustment of the contact condition between the rollers and raceways not only prevents abnormal loading on the contact surfaces but also accommodates misalignment between the inner and outer rings caused by installation errors.
The permitted tilt angles for cylindrical roller bearings are as follows:
| Bearing Type | Series | Permitted Tilt Angle |
|---|---|---|
| Narrow-type bearings | 10, 2, 3, and 4 series | 3.5 arcminutes |
| Wide-type bearings | 22 and 23 series | 1.5 arcminutes |
Tolerances
Single-row cylindrical roller bearings are produced with tolerances up to P5 grade. Additionally, single-row and double-row cylindrical roller bearings with tapered bores for machine tool spindles are manufactured with P5 grade and higher tolerances, as well as special tolerance classes SP and UP.
Radial Internal Clearance
| Bearing Type | Standard Clearance | Optional Clearance |
|---|---|---|
| Standard single-row (cylindrical bore) | Basic group | C3 (most sizes), C4 (some sizes) |
| Double-row cylindrical roller bearings | C1 group | C2 or C3 (cylindrical bore); C2 (tapered bore) |
Cages
The standard cages for single-row cylindrical roller bearings are listed in the table below. Cages for NU, NJ, NF, and NUP-type bearings are typically the same as those for N-type bearings.
| Cage Material | Suffix Code | Max. Operating Temperature | Application |
|---|---|---|---|
| Glass fiber-reinforced nylon 66 | TN | +120°C | Standard applications |
| Solid brass | M | High temperature | Continuous high-temp or harsh conditions |
| Stamped steel | — | — | Available on customer request |
Minimum Load
To prevent harmful sliding between the rollers and raceways due to centrifugal forces during high-speed operation, the minimum required load for the bearing can be estimated using the following formula:
- Fr — Minimum radial load (N)
-
Kr — Minimum load coefficient:
- = 100 for series 10 bearings
- = 150 for series 2, 3, and 4 bearings
- = 200 for series 22 bearings
- = 250 for series 23 bearings
- n — Rotational speed (r/min)
- nr — Limiting speed for oil lubrication (r/min)
- dm — Bearing mean diameter = 0.5 × (d + D) (mm)
Dynamic and Static Equivalent Loads
| Dimension Series | Condition (Fa/Fr) | Dynamic Equivalent Load P |
|---|---|---|
| Series 2 and 3 | 0 ≤ Fa/Fr ≤ 0.12 | P = Fr + 0.3Fa |
| 0.12 < Fa/Fr ≤ 0.3 | P = 0.94Fr + 0.8Fa | |
| Series 22 and 23 | 0 ≤ Fa/Fr ≤ 0.18 | P = Fr + 0.2Fa |
| 0.18 < Fa/Fr ≤ 0.3 | P = 0.94Fr + 0.53Fa |
Axial Load Capacity
Cylindrical roller bearings are primarily designed to carry radial loads. However, bearings with flanged rings (e.g., NJ, NF, and NUP types) can also accommodate certain axial loads. The axial load capacity depends mainly on the lubrication condition, operating temperature, and heat dissipation capabilities of the bearing.
The allowable axial load can be calculated using the following formula:
- Fap — Maximum allowable axial load (N)
- C0 — Basic static load rating (N)
- Fr — Actual radial load (N)
- n — Operating speed (r/min)
- d — Bearing inner diameter (mm)
- D — Bearing outer diameter (mm)
- K1 — 0.3 for oil lubrication; 0.5 for grease lubrication
- K2 — 0.03 for oil lubrication; 0.05 for grease lubrication
| Load Type | Multiplier | Maximum Limit |
|---|---|---|
| Constant axial load (Fa) | × 1 | Must not exceed 1.2D² (D in mm) |
| Temporarily applied axial loads | × 2 | — |
| Impact loads | × 3 | Occasional impact must not exceed 3D² |