9 sizes · 2 or 3 stages · 350 to 18,000Nm · hollow bore 30 to 120mm · up to 160kW
Shaft mounted gearboxes fit straight onto the shaft they drive, held by a reaction bolt, so there is no coupling, baseplate or alignment work. Motovario’s S Series covers 350Nm to 3,000Nm in five sizes, and the SN Series continues the range in four mid heavy duty sizes up to 18,000Nm, for screw conveyors, augers, belt and bucket conveyors and other direct shaft drives.
Both series are parallel shaft helical gear reducers with a hollow output shaft, in two or three reduction stages. Mounting on the driven shaft removes the need for couplings and a separate base, and a reaction bolt takes the reaction torque. The S Series universal casing can also be foot or flange mounted.
The S Series runs in five sizes, S052/053 to S122/123, from 350Nm to 3,000Nm at 1400rpm input (3,225Nm at 500rpm), with ratios from 7.34:1 to 394.69:1, hollow bores from 30mm to 60mm and geared motors from 0.09kW to 30kW. Casings are grey cast iron, with a cast iron cover on S122/123, finished in blue RAL 5010 epoxy-polyester powder, and Motovario quotes average efficiencies of 0.96 for two stages and 0.94 for three. Hollow (C), solid (D) and shrink disc (L) outputs are available, and ATEX versions are available.
The SN Series, launched in 2024, adds four larger sizes, SN142/143 to SN182/183, from 4,300Nm to 18,000Nm, with ratios from 4.28:1 to 222.16:1, hollow bores of 70, 90, 110 and 120mm, radial loads up to 100,000N and geared motors from 1.5kW to 160kW. Monobloc casings are grey cast iron on SN140 and SN150 and spheroidal cast iron on SN160 and SN180, and average efficiency is 0.98 for two stages and 0.96 for three.
| Specification | S Series | SN Series |
|---|---|---|
| Type | Parallel shaft helical, shaft mounted | Parallel shaft helical, shaft mounted, mid heavy duty |
| Sizes | S052/053, S062/063, S082/083, S102/103, S122/123 | SN142/143, SN152/153, SN162/163, SN182/183 |
| Reduction stages | 2 or 3 | 2 or 3 |
| Nominal output torque | 350 to 3,000Nm at 1400rpm input (3,225Nm at 500rpm) | 4,300 to 18,000Nm |
| Ratios | 7.34:1 to 394.69:1 | 4.28:1 to 222.16:1 |
| Average efficiency | 0.96 (2 stages); 0.94 (3 stages) | 0.98 (2 stages); 0.96 (3 stages) |
| Hollow output shaft | 30 to 60mm | 70, 90, 110 and 120mm |
| Output versions | C hollow; D solid (30 to 60mm); L hollow with shrink disc | C hollow; D solid (70 to 120mm); L hollow with shrink disc; extruder version |
| Input versions | S IEC motor adaptor; PS adaptor with flexible coupling; CS compact geared motor; IS solid input shaft | SN IEC motor adaptor (B5, motor frames 100/112 to 315); ISN solid input shaft |
| Power | 0.09 to 30kW | 1.5 to 160kW |
| Maximum radial load | Up to 30,000N (solid output shaft, S122/123) | 100,000N |
| Mounting | Shaft mounted with reaction bolt; output flanges; universal foot-flange casing | Shaft mounted with reaction bolt; output flanges |
| Housing | Grey cast iron; cast iron cover on S122/123 | Monobloc; grey cast iron (SN140, SN150), spheroidal cast iron (SN160, SN180) |
| Finish | Blue RAL 5010 epoxy-polyester powder | Blue RAL 5010 acrylic over two-component primer |
| Lubrication | S052/053 and S062/063 lubricated for life (no oil plugs); S082/083 and S102/103 supplied filled, with oil plugs; S122/123 supplied without oil | Supplied without oil; mineral or synthetic |
| Options | Backstop device, reinforced output oil seals, assembly and disassembly kit | Backstop device, assembly and disassembly kit |
| Size | Nominal torque (Nm) | Hollow bore (mm) |
|---|---|---|
| S052/053 | 350 | 30 |
| S062/063 | 600 | 35 |
| S082/083 | 1,000 | 40 or 45 |
| S102/103 | 1,600 | 45 or 50 |
| S122/123 | 3,000 | 55 or 60 |
| SN142/143 | 4,300 | 70 |
| SN152/153 | 8,000 | 90 |
| SN162/163 | 13,000 | 110 |
| SN182/183 | 18,000 | 120 |
Source: S Series: Motovario TECHNICAL CATALOGUE S / IEC / STD / EN / REV.0 / 2026 (IS reducer tables at 1400rpm input, dimensions, lubrication). SN Series: Motovario SN Series Standard IEC Technical Catalogue (ISN reducer tables at 1450rpm input) and the Motovario SN product page. Checked 2 November 2026.
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A gearbox with a hollow output shaft that slides directly onto the shaft it drives, such as a conveyor head shaft or an auger. A reaction bolt stops the gearbox body rotating. It removes the need for couplings, a baseplate and shaft alignment.
The SN Series is Motovario’s mid heavy duty extension of the S range, launched in 2024. The S Series covers 350Nm to 3,000Nm with bores from 30mm to 60mm; the SN Series runs from 4,300Nm to 18,000Nm with bores from 70mm to 120mm, higher radial loads and motors up to 160kW.
Direct shaft drives such as screw conveyors, augers, belt and bucket conveyors, overland conveyors, mixers and agitators, where the gearbox can sit on the driven shaft. Motovario also offers an SN version for extruders.
The hollow output slides onto the driven shaft and is secured with a key or a shrink disc. The reaction bolt is then fixed to the machine frame to absorb the reaction torque without forcing the shaft out of line. An assembly and disassembly kit is available.
S052/053 and S062/063 are lubricated for life with no oil plugs, and S082/083 and S102/103 are supplied filled with oil plugs. S122/123 and all SN sizes are supplied without oil and filled on installation, so the mounting position must be specified.
Yes. A backstop device prevents reverse rotation, for example on an inclined conveyor when the drive stops.
Browse the S Series by size, ratio and bore, or send us the torque, output speed and shaft diameter and we will specify the S or SN 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
