Overview
B143 21:1 bevel helical gearbox with a 70mm hollow bore output and 100-112B5 IEC motor input for compact 90° right-angle drive integration.
Designed to handle demanding loads, it combines efficient gearing with robust construction for reliable 90° transmission in compact machine layouts.
Mid reduction: A 21:1 mid reduction ratio provides steady running under load with a practical torque increase for general plant and OEM equipment.
This configuration includes a 70mm hollow output bore and a 100-112B5, providing dependable speed reduction and consistent torque delivery for conveyors, automation lines, packaging machinery, and OEM equipment builds.
With its larger 100–112B5 flange input, this version is intended for bigger IEC frame motors, offering higher input capacity and wider motor compatibility while maintaining a compact 90° installation footprint and proven heavy-duty reliability.
As part of the modular Motovario B143 bevel helical gearbox range, this unit supports multiple mounting orientations, straightforward IEC motor fitment, and dependable long-term performance for continuous industrial service.
Need the non standard 65mm bore option?
If you need an output bore other than the standard 70mm, alternative configurations may be available subject to supply. View the B143 range and request your required bore option here: Motovario B143 Gearbox.
Key Specifications
- Series: B Series – Bevel Helical Gearboxes
- Model: B143
- Reduction Ratio: 21.00:1
- Output Bore: 70mm Hollow Bore
- Motor Input: 100-112B5 IEC Flange
- Housing Material: High-strength cast iron
- Gear Type: Spiral bevel + hardened helical stage
- Mounting Positions: B3 Mount
- Duty Rating: Suitable for continuous industrial operation (S1)
Manufactured with hardened, precision-ground gear geometry to improve efficiency and help minimise heat build-up under continuous load.
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 | ~67 rpm |
| 2-Pole | 2800 | ~133 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 100-112B5 IEC motor input. Confirm flange compatibility below:
| Motor Input | IEC Standard | Input Dimensions |
|---|---|---|
| 100-112B5 | IEC 60072 / IEC 60034 (B5 flange) | Ø250 x 28 |
If you’re unsure whether your motor is B5 or B14, contact our technical team and we’ll confirm compatibility.
Internal Links & Compatible Options
Same ratio, different motor input: jump to the B143 21:1 variant you need (70mm bore).
Need a different ratio? Explore the closest B143 70mm bore ratios above and below this version.
More B143 options: Browse all Motovario B143 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
✔ Compact 90° right-angle bevel layout for space-efficient installations
✔ Precision-cut spiral bevel gearing for quiet running and efficient power transfer
✔ Hardened helical stage supports smooth torque transmission and long service life
✔ Heavy-duty bearing design to cope with high radial and axial shaft loading
✔ Well suited to VFD-driven motors for variable-speed process control
✔ Robust cast iron housing built for OEM machinery and continuous industrial operation
Ratio Selection Tips
- Best for: applications needing responsive motion with a torque uplift — suited to indexing, feeders, and compact right-angle machine builds.
- Selection tip: for higher output speed, low reduction is often right — just check duty, shock loading, and whether a VFD will be used for fine control.
FAQ
Will this ratio be too fast for my application?
If you need slower output speed, choose a mid or high reduction ratio. Low ratios are best when you want higher output rpm while still gaining torque.
Can I run this with a VFD?
Yes — a VFD is ideal for accurate speed control. For long periods at very low motor speeds, ensure adequate motor cooling if running at reduced frequency.
Configuration Notes
- Input flange note: the 100–112B5 IEC input suits larger IEC motors, increasing input capacity and expanding motor compatibility for heavier-duty applications.
- Output bore note: the 70mm hollow bore supports larger shaft interfaces and higher loading, providing a rigid, secure connection for torque transmission.
- Application example: indexing table or light materials handling drive where responsiveness and compact 90° layout are key
Typical Applications
- Fast conveyor zones and transfer stations
- Indexing tables, feeders, and pick-and-place sub-systems
- Packaging lines (wrappers, case packers, label/print stations)
- Roller conveyor drives and accumulation sections
- Small OEM machine builds needing compact 90° transmission
- General automation where higher output rpm is required
Need help selecting the correct ratio, bore size, or motor input?
Contact our gearbox specialists for sizing support, torque checks, and availability confirmation.
Reviews
There are no reviews yet.