TXF and S Series · up to 7.5kW · up to 144Nm · 4 pole output 190 to 1000rpm · zero-speed version
Motovario’s motovariators change output speed mechanically while the motor runs at a constant speed. The compact aluminium TXF Series covers motors up to 2.2kW and the cast iron S Series up to 7.5kW. Both can be combined with Motovario helical and worm gearboxes for lower output speeds.
A Motovario variator uses planet discs running between two inner races on the motor shaft and two outer races fixed to the casing. Turning the handwheel moves one outer race through a cam ring, which changes the radius at which the planets run and so the speed of the planet carrier on the output shaft. Speed is adjusted smoothly, with the unit running, to a sensitivity of 0.5rpm, over a range of roughly 5:1: with a 4 pole motor, about 1000 down to 190rpm on the S Series. Slip at maximum load is 5%.
The TXF Series comes in three sizes, TXF002, TXF005 and TXF010, with die-cast aluminium casings, for motors up to 2.2kW and output torque up to 12Nm at minimum speed. The S Series comes in seven sizes, S003 to S100, with G200 grey cast iron casings, for motors up to 7.5kW and output torque up to 144Nm. S versions include flanged (SF) and foot mounted units, motorised and input shaft versions, and the SD with an epicyclic differential that takes the output speed down to zero. Shafts are 20MnCr5 steel and internal parts 100Cr6.
For lower output speeds and higher torque, the variators combine with Motovario helical gear reducers (VH cast iron, with motors up to 15kW; VHA aluminium, up to 2.2kW) and NMRV worm gearboxes (SF+NMRV up to 7.5kW; TXF+NMRV up to 1.5kW), with output torque up to 5,000Nm. An electrical servocontrol is available as an option. ATEX versions are available in categories 2GD and 3GD.
| Specification | TXF Series | S Series |
|---|---|---|
| Sizes | TXF002, TXF005, TXF010 | S003, S005, S010, S020, S030, S050, S100 |
| Motor power | Up to 2.2kW | Up to 7.5kW |
| Output speed, 2 pole motor | 2000 to 340rpm | 2000 to 380rpm |
| Output speed, 4 pole motor | 1000 to 170rpm | 1000 to 190rpm (SD: 1000 to 0rpm) |
| Output speed, 6 pole motor | 643 to 109rpm | 660 to 122rpm |
| Output torque | Up to 12Nm (at minimum speed) | Up to 144Nm (at minimum speed) |
| Versions | Compact, motor mounted | Flanged (SF, SPF), foot (ST, SP) or compact; motorised or input shaft; SD with differential to 0rpm |
| Speed control | Handwheel (either side), 0.5rpm sensitivity; electrical servocontrol option | Handwheel (either side), 0.5rpm sensitivity; electrical servocontrol option |
| Slip at maximum load | 5% | 5% |
| Casing | Die-cast aluminium | G200 grey cast iron |
| Materials | Shafts 20MnCr5; internal parts 100Cr6 | Shafts 20MnCr5; internal parts 100Cr6 |
| Lubrication | Supplied with ISO VG32 oil | Supplied with ISO VG32 oil |
| Combinations | TXF+NMRV worm (motors up to 1.5kW); VHA aluminium helical (up to 2.2kW) | SF+NMRV worm (up to 7.5kW); VH cast iron helical (motors up to 15kW, up to 5,000Nm) |
| Finish | Blue RAL 5010 | Blue RAL 5010 |
| ATEX | 2GD and 3GD versions | 2GD and 3GD versions |
| Size | Motor power (kW) | Output torque at min. speed (Nm) |
|---|---|---|
| TXF002 | 0.37 | 4 |
| TXF005 | 0.25 to 1.1 | 6 |
| TXF010 | 0.55 to 2.2 | 12 |
| S003 | 0.37 | 4 |
| S005 | 0.25 to 0.75 | 6 |
| S010 | 0.55 to 1.1 | 12 |
| S020 | 1.1 to 2.2 | 24 |
| S030 | 1.5 to 3 | 48 |
| S050 | 2.2 to 4 | 64 |
| S100 | 5.5 to 7.5 | 144 |
Source: Motovario TECHNICAL CATALOGUE VAR / IEC / STD / EN / REV.0 / 2024 (motovariators TXF and S, and VH, VHA and NMRV combinations): design features and performance tables (output speeds and torques at maximum and minimum speed); Motovario VAR product pages. Checked 2 November 2026.
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A mechanical speed changer fitted between a constant-speed motor and the load. Turning a handwheel varies the output speed smoothly, without an inverter or any electronics.
With the handwheel, which can be fitted on either side, and only while the unit is running. Adjustment sensitivity is 0.5rpm. An electrical servocontrol is available as an alternative.
Where electronics are impractical: harsh or wet conditions, remote sites without controls, mobile equipment, or simple machines where the operator sets the speed by hand.
Size, power and casing. The TXF is the compact die-cast aluminium range for motors up to 2.2kW. The S Series is cast iron, runs to 7.5kW and 144Nm, and includes the SD zero-speed version.
Yes, with the SD version. Its epicyclic differential lets the output speed run from maximum down to 0rpm.
Yes. Motovario combines its variators with VH cast iron and VHA aluminium helical gear reducers and with NMRV worm gearboxes for lower output speeds and higher torque, up to 5,000Nm.
Browse TXF and S variators by size and motor power, or send us the nameplate of the variator you are replacing and we will match it.
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
