Importance of Fit Accuracy
The accuracies of the fits and the geometrically correct design of all connecting parts are decisive for bearing function. Errors in the adjacent construction can substantially increase the friction torque.
The actual bearing bore dimension is provided in the inspection report accompanying each bearing.
Shaft Dimension Diagram
Design Notes
Important Notes
- Envelope condition applies - Dimensional tolerances include the form tolerance requirement
- Countersink for threaded holes - The threaded holes on the shaft require a countersink to accommodate the head of the fixing screw
- Minimum support requirement - The shaft must provide full surface support across the entire bearing height
- Surface roughness - Ra 0.8 µm (mating surfaces)
Inner Ring Rotating (NGS Series)
Design the shaft diameter according to the specifications of the tolerance table below.
High Running Accuracy
For maximum running accuracy, the clearance fit should approach zero. This prevents an increase in radial runout.
Accuracy Recommendation
The fit clearance should be controlled to approach 0 µm in order to avoid an increase in radial runout caused by clearance. When the maximum speed is to be reached, the clearance should approach 0, biased slightly towards the clearance side.
High Speed with Long Duty Cycles
To reach the limiting speed for long duty cycles, the interference fit must not exceed 0.005 mm.
High Speed Application Notes
The interference should be kept within 5 µm (0.005 mm) to avoid an excessive preload increase and frictional heating. An excessive interference fit causes excessive bearing temperature rise and reduces service life.
Oscillating Duty
Under oscillating motion duty, the shaft should be designed to the h5 tolerance.
Inner Ring Stationary (NGS-SBI Series)
Design the shaft diameter according to the specifications of the tolerance table below.
Full Surface Support Requirement
The bearing inner ring on a stationary shaft requires full surface support. The shaft must provide a complete supporting surface across the entire bearing height.
Shaft Fit Tolerance Table
The following are the recommended shaft fit values for each AXRY-NGS (NGS-SBI) bearing size:
- di - Bearing bore diameter (Shaft bore diameter, mm)
- Tolerance - Shaft diameter tolerance range (mm)
- J - Pitch circle diameter (Teilkreis; pitch circle diameter of the inner-ring fixing screw holes, mm)
- H - Bearing height (Height, mm)
- T1 - Roundness tolerance (Rundheit, µm)
- T2 - Parallelism tolerance (Parallelität, µm)
- T3 - Perpendicularity tolerance (Rechtwinkligkeit, µm)
- Rmax - Maximum fillet radius (mm)
| Model | di [mm] | Tolerance [mm] | J [mm] | H [mm] | T1 [µm] | T2 [µm] | T3 [µm] | Rmax [mm] |
|---|---|---|---|---|---|---|---|---|
| AXRY 120-NGS (-SBI) | 120 | -0.005 / -0.015 | 135 | 40 | 3 | 1.5 | 3 | 0.1 |
| AXRY 180-NGS (-SBI) | 180 | -0.008 / -0.020 | 194 | 43 | 4 | 2 | 4 | 0.1 |
| AXRY 200-NGS (-SBI) | 200 | -0.010 / -0.024 | 215 | 45 | 6 | 2.5 | 5 | 0.1 |
| AXRY 260-NGS (-SBI) | 260 | -0.013 / -0.029 | 280 | 55 | 8 | 2.5 | 7 | 0.3 |
| AXRY 325-NGS (-SBI) | 325 | -0.018 / -0.036 | 342 | 60 | 8 | 2.5 | 7 | 0.3 |
| AXRY 395-NGS (-SBI) | 395 | -0.018 / -0.036 | 415 | 65 | 8 | 2.5 | 7 | 0.3 |
| AXRY 460-NGS (-SBI) | 460 | -0.018 / -0.038 | 482 | 70 | 8 | 2.5 | 7 | 0.3 |
| AXRY 580-NGS (-SBI) | 580 | -0.020 / -0.042 | 610 | 90 | 10 | 4 | 8 | 1 |
| AXRY 650-NGS (-SBI) | 650 | -0.033 / -0.057 | 680 | 122 | 10 | 4 | 8 | 1 |
- Envelope requirement applies: the dimensional tolerance already includes the form tolerance requirement.
- Countersink for threaded holes (Gewindesenkung): the threaded holes at pitch circle J on the shaft require a countersink to accommodate the screw head.
- Full surface support (entire bearing height): the shaft must provide a complete supporting surface across the full height H.
Related Sections
- Recommended Fits for Housing - Housing fit tolerance selection
- Adjacent Construction Design - Design principles and accuracy requirements
- Bearing Commissioning - Run-in and verification procedures