3 casing sizes · 120 to 450Nm · 2 or 3 stages · ratios 7.62 to 442.76:1 · hollow bore 20 to 35mm
The BA Series puts a bevel helical gear train in a compact die-cast aluminium casing. With an average efficiency of 0.95 in two-stage form, it is an efficient alternative to a worm gearbox at the same duty, from 120Nm to 450Nm. For higher torque, the cast iron B Series runs to 13,000Nm.
The BA Series comes in three casing sizes and five designations: BA42 (two-stage), BA52 and BA53 (two and three-stage), and BA72 and BA73 (two and three-stage). Nominal output torque runs from 120Nm on the BA42 to 450Nm on the BA73, and ratios from 7.62:1 to 442.76:1, so one compact unit covers duties that would otherwise need a worm gearbox with a high ratio.
Motovario quotes an average efficiency of 0.95 for the two-stage units and 0.9 for the three-stage units. Casings are die-cast aluminium alloy, shot-peened, washed and passivated, then finished in blue RAL 5010 epoxy-polyester powder.
The bevel stage is a hypoid gear pair on the BA40 and BA50 casings and a Gleason bevel pair on the BA70. Each unit is available as a compact geared motor (CBA), with an IEC motor adaptor in B5 or B14 for motors from IEC 63 to 112 (BA), or with a solid input shaft (IBA). The universal casing mounts on feet or a flange, the output is a hollow shaft from 20mm to 35mm (with solid output shafts on the BA70), and torque arms and output flanges are available for shaft mounting.
| Specification | BA Series |
|---|---|
| Type | Helical bevel gear reducer / geared motor, right-angle output |
| Casing sizes | BA40 (BA42), BA50 (BA52, BA53), BA70 (BA72, BA73) |
| Reduction stages | 2 (BA42, BA52, BA72) or 3 (BA53, BA73) |
| Nominal output torque | 120 to 450Nm (Mn2 at 1400rpm input) |
| Ratios | 7.62:1 to 442.76:1 |
| Average efficiency | 0.95 two-stage; 0.9 three-stage |
| Input versions | CBA compact geared motor; BA with IEC motor adaptor (B5 or B14); IBA solid input shaft |
| Motor sizes | IEC 63 to 112 |
| Motor power | Up to 5.5kW [confirm] |
| Bevel gearing | Hypoid (BA40, BA50); Gleason (BA70) |
| Output | Hollow shaft, 20 to 35mm bore; single or double solid output shaft on BA70 only |
| Maximum radial load | 10,000N |
| Mounting | Universal casing for foot or flange mounting; output flange; shaft mounted with torque arm |
| Casing | Die-cast aluminium alloy, shot-peened, washed and passivated |
| Finish | Blue RAL 5010 epoxy-polyester powder |
| Lubrication | Supplied filled with mineral oil; no oil plugs, lubricated for life and maintenance-free |
| ATEX | 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 | Stages | Nominal torque (Nm) | Ratio range | Hollow bore (mm) |
|---|---|---|---|---|
| BA42 | 2 | 120 | 7.62 to 78.17 | 20 |
| BA52 | 2 | 220 | 7.91 to 79.07 | 25 or 28 |
| BA53 | 3 | 220 | 73.70 to 342.65 | 25 or 28 |
| BA72 | 2 | 420 | 8.36 to 67.96 | 30 or 35 |
| BA73 | 3 | 450 | 43.89 to 442.76 | 30 or 35 |
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.
Efficiency. A two-stage BA unit averages 0.95 and a three-stage unit 0.9, because every stage is helical or bevel gearing. A worm gearbox loses more energy as heat, especially at higher ratios, so the BA can often run the same right-angle duty with a smaller motor or lower running costs.
The BA Series is die-cast aluminium, from 120Nm to 450Nm. The B Series is cast iron, with seven sizes from 600Nm to 13,000Nm, for heavier duties.
The first digit is the casing size and the second the number of reduction stages. A BA52 is a size 5 casing with two stages; a BA73 is a size 7 casing with three stages.
IEC motors from frame 63 to frame 112, with B5 or B14 motor adaptors, or a Motovario compact motor in the CBA version. Motovario three phase motors and brake motors cover this frame range.
No. Every BA unit is supplied filled with lubricant and has no oil plugs, so it is lubricated for life and needs no routine oil maintenance.
The universal casing can be foot or flange mounted, or the unit can be shaft mounted on the driven shaft through its hollow output and held by a torque arm. Output flanges are available too.
Browse the BA Series by size, ratio and bore, or tell us the torque, output speed and motor 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
