Overview
B103 30.55:1 bevel helical gearbox with a 50mm hollow bore output and 132B5 IEC motor input for compact 90° right-angle drive integration.
Engineered for continuous-duty operation, this configuration delivers dependable torque transfer and smooth running under load.
High reduction: This high reduction ratio prioritises torque multiplication and controlled output speed, suited to heavier conveyors, process machinery, and positioning applications.
Need the non-standard 45mm bore option?
If your application requires a 45mm output bore instead of the standard 50mm, we can supply this as a non-standard configuration. View available B103 options and request the 45mm version here: Motovario B103 Gearbox.
Key Specifications
- Series: B Series – Bevel Helical Gearboxes
- Model: B103
- Reduction Ratio: 30.55:1
- Output Bore: 50mm Hollow Bore
- Motor Input: 132B5 IEC Flange
- Housing Material: High-strength cast iron
- Gear Type: Spiral bevel + hardened helical stage
- Mounting Positions: B3 Horizontal Mount
- Duty Rating: Suitable for continuous industrial operation (S1)
Output Speed (4-Pole vs 2-Pole Motors)
Calculated nominal output speed using a standard IEC motor:
| Motor Type | Input Speed (rpm) | Estimated Output Speed (rpm) |
|---|---|---|
| 4-Pole | 1400 | ~46 rpm |
| 2-Pole | 2800 | ~92 rpm |
Need torque confirmation? Output torque depends on motor power (kW), gearbox efficiency, and service factor. Use our Gearbox Service Factor Calculator or contact us for verified torque figures.
Motor Input Chart (IEC Flange Details)
This gearbox is supplied with a 132B5 IEC motor input. Confirm flange compatibility below:
| Motor Input | IEC Standard | Input Dimensions |
|---|---|---|
| 132B5 | IEC 60072 / IEC 60034 (B5 flange) | Ø300 × 38 |
If you’re unsure whether your motor is B5 or B14, contact our technical team for compatibility confirmation.
Internal Links & Compatible Options
Same ratio, different motor input: jump to the B103 30.55:1 variant you need (50mm bore).
Need a different ratio? Explore the closest B103 50mm bore ratios above and below this version.
More B103 options: Browse all Motovario B103 gearbox ratios
Explore the full B Series range: Motovario B Series bevel gearboxes
Helpful calculators:
Gearbox Ratio & Speed Calculator |
Output Torque Calculator
Performance & Design Features
✔ Space-saving 90° bevel layout for compact machine designs
✔ Strong torque multiplication with stable, controlled output speeds
✔ Precision-machined spiral bevel gearing for smooth, low-noise power transfer
✔ Heavy-duty taper roller bearings for high radial and axial load handling
✔ Well suited to inverter (VFD) driven motors and variable-speed control
✔ Rigid cast iron housing built for OEM and continuous-duty operation
Ratio Selection Tips
- Best for: balanced duties where speed control and torque both matter — strong choice for production conveyors, turntables, light mixers, and general materials handling.
- Selection tip: for general machinery, mid reduction gives stable control — verify continuous torque demand and pick the ratio that keeps the motor in its efficient speed range.
FAQ
Is this a good general-purpose ratio?
Yes — mid reduction ratios are typically the best balance for many machines, providing controlled speed with useful torque multiplication.
How do I choose between two close ratios?
Pick the ratio that keeps your target output speed closest at the motor speed you’ll actually run (direct-on-line or via VFD), then confirm required torque and service factor.
Configuration Notes
- Input flange note: the 132B5 flange supports large IEC motors where sustained torque and continuous-duty reliability are critical.
- Output bore note: the 50mm hollow shaft bore is a common industrial size for conveyors and handling equipment, offering a strong shaft interface for torque transmission.
- Application example: Example use: turntable or rotary indexing system needing controlled speed with dependable torque multiplication.
Typical Applications
- Conveyor and line-shaft drive systems
- Automated production and assembly lines
- Food and beverage processing machinery
- Materials handling and logistics equipment
- Pumps, mixers, and agitator drives
- OEM machine and equipment builds
Need help selecting the correct ratio, bore size, or motor input?
Contact our gearbox specialists for sizing assistance, torque verification, and availability confirmation.
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