7 sizes · up to 13,000Nm · ratios 5.71 to 187.24:1 · hollow bore 35 to 100mm · up to 90kW
The B Series is Motovario’s cast iron bevel helical range: three reduction stages, a right-angle output and seven sizes from B063 to B163. Units are available as compact geared motors, with an IEC motor adaptor or with a solid input shaft, and with a hollow or solid output shaft. For lighter duties, the aluminium BA Series covers 120 to 450Nm.
A bevel helical gearbox combines helical gear stages with a bevel gear pair, turning the drive through 90 degrees while keeping the efficiency of helical gearing. On the B Series the second stage is a Gleason spiral bevel gear pair, and Motovario quotes an average efficiency of 0.9 for the three-stage unit.
The range runs in seven sizes, B063, B083, B103, B123, B143, B153 and B163, with nominal output torque from 600Nm to 13,000Nm and ratios from 5.71:1 to 187.24:1. Housings are high-strength grey cast iron (G200), optimised with FEM analysis and finished in blue RAL 5010 epoxy-polyester powder, and the B Series accepts radial loads of up to 80,000N on the largest size.
Each size can be built as a compact geared motor (CB), with an IEC motor adaptor for motors from IEC 63 on the B063 up to IEC 280 on the B163 (B), with a motor adaptor and flexible coupling (PB, from B083), or with a solid input shaft (IB), for geared motors up to 90kW. The casing comes in foot, flange or universal versions. The hollow output shaft has two bore options on most sizes, with single or double solid output shafts, a shrink disc on B143 to B163, an output flange on B063 to B123 and a torque arm for shaft mounting.
| Specification | B Series |
|---|---|
| Type | Helical bevel gear reducer / geared motor, right-angle output |
| Sizes | B063, B083, B103, B123, B143, B153, B163 |
| Reduction stages | 3 |
| Nominal output torque | 600 to 13,000Nm (Mn2 at 1400rpm input) |
| Ratios | 5.71:1 to 187.24:1 |
| Average efficiency | 0.9 |
| Input versions | CB compact geared motor; B with IEC motor adaptor (B5 and B11 flanges); PB motor adaptor with flexible coupling (not on B063); IB solid input shaft |
| Geared motor power | Up to 90kW |
| Motor sizes | IEC 63 to 280, depending on gearbox size |
| Output | Hollow shaft (35 to 100mm bore); single or double solid output shaft; hollow shaft with shrink disc (B143 to B163); output flange (B063 to B123) |
| Maximum radial load | 80,000N (B163) |
| Mounting | Foot, flange or universal casing; shaft mounted with torque arm |
| Housing | High-strength grey cast iron (G200), optimised with FEM analysis; cast iron inspection cover on B143, B153 and B163 |
| Finish | Blue RAL 5010 epoxy-polyester powder |
| Lubrication | B063 lubricated for life (no oil plugs); B083 to B123 supplied filled with mineral oil (ISO VG220) and fitted with oil plugs; B143 to B163 supplied without oil. Synthetic and food grade lubricants available |
| Options | Backstop device, Viton or reinforced output oil seals, output shaft cover, assembly and disassembly kit |
| ATEX | 2GD and 3GD versions available |
| Design standards | DIN 3990, ISO 6336, AGMA 2101, ISO 10300, DIN 3991, ISO 281, DIN 743 |
Second table: BA Series sizes.
| Size | Nominal torque (Nm) | Ratio range | Hollow bore (mm) | IEC motor sizes |
|---|---|---|---|---|
| B063 | 600 | 5.71 to 157.42 | 35 or 40 | 63 to 112 |
| B083 | 850 | 7.81 to 144.77 | 40 or 45 | 80 to 132 |
| B103 | 1,800 | 8.13 to 165.25 | 45 or 50 | 80 to 160 |
| B123 | 3,500 | 7.97 to 180.40 | 55 or 60 | 90 to 180 |
| B143 | 5,000 | 10.84 to 187.24 | 70 | 100 to 200 |
| B153 | 8,000 | 10.49 to 165.42 | 80 or 90 | 132 to 225 |
| B163 | 13,000 | 8.89 to 154.83 | 100 | 160 to 280 |
Source: Motovario B Series Standard IEC Technical Catalogue (helical bevel geared motors, B and BA), as held in the Betech download library, with nominal torque Mn2 and ratio ranges from the IB/IBA reducer tables at 1400rpm input and motor sizes from the motor flange availability tables; cross-checked against the Motovario helical bevel product pages (cast iron and aluminium) and Motovario brochure DP-B EN/2019/REV.0. Checked 1 November 2026.
For technical information, brochures and further product details, visit our downloads page.
The B is the series, the first digits are the casing size and the last digit is the number of reduction stages. A B103 is a size 10 unit with three stages, rated at 1,800Nm; a B083 is a size 08 unit rated at 850Nm. Every B Series size is three-stage.
Housing material and size. The B Series is cast iron and runs from 600Nm to 13,000Nm. The BA Series is die-cast aluminium, with two or three stages and three casing sizes from 120Nm to 450Nm, for lighter duties.
Motovario gives an average efficiency of 0.9 for the three-stage B Series. Because every stage is helical or bevel gearing, efficiency stays high across the ratio range, which is the main reason to choose a bevel helical unit over a worm gearbox for a right-angle drive.
Yes. With a hollow output shaft, or a hollow shaft with shrink disc on sizes B143 to B163, the gearbox mounts directly on the driven shaft and is held by a torque arm. Foot, flange and universal casings are also available.
The B063 is filled with lubricant for life and has no oil plugs. Sizes B083 to B123 are supplied filled with mineral oil (ISO VG220) and fitted with oil plugs for any catalogue mounting position. Sizes B143 to B163 are supplied without oil and are filled on installation, so the mounting position must be specified. Synthetic and food grade lubricants are available.
Yes. Motovario offers the B Series in ATEX category 2GD and 3GD versions for hazardous areas.
IEC motors from frame 63 up to frame 280, depending on gearbox size, through B5 or B11 motor adaptors. Motovario three phase motors and brake motors can be fitted to make a complete geared motor.
Browse the B Series by size, ratio and bore, or send us the torque, output speed and mounting you need and we will specify the unit.
Contact
Betech 100pt Ltd
Four Square Buildings, Thomas Street
Heckmondwike, West Yorkshire, WF16 0LS
Telephone: 01924 411921
Email: sales@betech.co.uk
Opening hours: 8:00 to 17:00
