Pneumatic Motors and Gear Reducers for Hazardous and Heavy-Duty Drives
Seven air motors and three gear reducers. Four axial piston models from 0.8 to 2.6 kW for torque at low speed, three vane models up to 7,000 rpm for speed in a small package, and parallel shaft, worm and planetary reducers to turn that speed into torque. Every model is built in three versions: underground ATEX, surface ATEX and standard.
- An air motor can sit stalled indefinitely without damage, which no electric motor will do
- No heat, no sparks, no electrics at the drive, and unaffected by dust and moisture
- Manufactured in Ankara since 1991, in ISO 9001, 14001 and 45001 certified production
4 models - 0.8 to 2.6 kWAxial piston motorsTorque at low speed. The EP series turns slowly and pulls hard, up to 24.2 Nm at 880 rpm.EP20 - EP40 - EP80 - EP120 
3 models - up to 7,000 rpmVane motorsSpeed in a small package. The ZM and STRC series run fast and light, from a 5.4 kg body.ZM10 - ZM80 - STRC1650 
3 types - ratios to 1:40Gear reducersTrade speed for torque. Parallel shaft in line, worm at 90 degrees, planetary coaxial.Parallel shaft - Worm ZR10-1000 - Planetary RR10-1000 An air motor is sized by the load it has to hold, not the load it has to turn
This is the one habit that has to change when an engineer moves from electric drives to pneumatic ones. With an electric motor you pick the rated power and protect it against stalling, because a stalled electric motor burns out in seconds. An air motor has no such failure mode: it simply stops, keeps full torque on the shaft and waits. So the number you specify against is the stall torque, and that changes which motor you buy.
It can stall indefinitely
Hold the shaft and an air motor stops turning, holds its torque and takes no harm. There is nothing to overheat and nothing to trip. That makes it the natural drive for anything that can jam: a mixer in setting material, a winch at the end of its travel, a valve against its seat, a conveyor against a blockage. Stall torque on these motors is about twice the torque at maximum power, so a motor sized on rated torque alone is undersized for the jam.
It is unaffected by the environment
No electrics at the drive, so no heat, no sparks, no insulation to break down. Dust, water, washdown, vibration and temperature swings do not change how it behaves, and it starts just as well wet as dry. That is why these motors end up in mines, quarries, chemical plants, grain handling and food plants, where an electric motor needs an enclosure and a certificate before it is allowed near the work.
Speed and torque are adjustable at the valve
Throttle the air and the motor slows; it does not stall and it does not need a drive. There is no inverter, no feedback loop and nothing to fail in it, which also means no electrical noise. Add a reducer and the same motor covers a different part of the map entirely: a 1:40 parallel shaft unit behind an EP80 turns 17.9 Nm into roughly 700 Nm at about 28 rpm, before losses.
It is small for its output
Power to weight is where air motors are hard to beat. The ZM10 gives 1.6 kW from 6.3 kg; an electric motor of that output weighs several times as much before you add the drive and the enclosure. On anything portable, anything hoisted, or anything mounted where the weight hangs off a bracket, that difference decides the design.
The honest trade-off: compressed air is an expensive way to move energy around compared with electricity, so an air motor is not the answer where an ordinary electric drive would be allowed and left alone. It is the answer where stalling, the atmosphere, the washdown or the weight rules an electric drive out.
Which motor for which drive
Start from what the drive has to do rather than from a power rating. Air motor and electric motor kW figures are not comparable, because the air motor is specified around torque at the shaft and the behaviour at stall.
| If the drive has to | Start from | Why that one |
|---|---|---|
| Pull hard at low speed | EP80 or EP120 | Axial piston: 17.9 and 24.2 Nm at 1,100 and 880 rpm |
| Run fast in a small, light body | ZM10 or STRC1650 | Vane: 7,000 rpm free, 6.3 and 5.4 kg |
| Hold against a load that can jam | Size on stall torque | Stall is about twice rated: 48.4 Nm on EP120, 15 Nm on ZM80 |
| Work in a gas or dust classified area | The ATEX version | Same motor, different certification; name the version when ordering |
| Turn slowly with much more torque | Motor plus parallel shaft reducer | Ratios 1:20 to 1:40, up to 3,000 rpm at the input |
| Drive at a right angle to the motor | Worm reducer ZR10-1000 | 25:1, output at 90 degrees, for tight spaces |
| Drive in line with the motor, coaxially | Planetary reducer RR10-1000 | 24:1, 180 degree operating angle |
| Replace an electric motor on an existing machine | Send us the frame and duty | We match torque and speed at the shaft, not the nameplate kW |
Scroll the table sideways to see every column.
What we make, and what we do not
We are asked regularly for pneumatic equipment that is nothing like this, so the boundary is worth stating before you spend time specifying.
What we make
- Axial piston air motors, four models, 0.8 to 2.6 kW
- Vane type air motors, three models, up to 7,000 rpm free speed
- Underground ATEX, surface ATEX and standard versions of every model
- Parallel shaft gear reducers in 1:20, 1:25, 1:30 and 1:40
- Worm and planetary reducers, ZR10-1000 at 25:1 and RR10-1000 at 24:1
- Motor and reducer supplied as a matched drive where you tell us the output you need
What we do not make
- No electric motors and no variable frequency drives
- No hydraulic motors, pumps or power packs
- No air compressors, receivers or dryers; we specify the air you need, we do not supply it
- No pneumatic cylinders, actuators or valves as products in their own right
- No hand-held air tools such as grinders, impact wrenches or drills driven by these motors
- No servo, stepper or geared electric drive units of any kind
The filter, regulator and lubricator that an air motor needs on its supply line are on our accessories and consumables page. If the drive you are describing is really a rock drill or a breaker, those are on rock drills and DTH hammers instead.
Air motors: axial piston and vane
Two families, one job, opposite ends of the speed and torque map. The axial piston EP motors drive a swashplate with four pistons: they turn slowly and pull hard, which suits mixers, winches, conveyors and anything where the load is heavy and the speed is not the point. The vane ZM and STRC motors spin a slotted rotor with sliding blades: they run fast, weigh little and have one consumable wear part. Between them they cover 0.8 to 2.6 kW and 880 to 7,000 rpm. Both families are built in all three certification versions.
Tell us the torque and speed you need at the shaft, the load's behaviour when it jams, and whether the area is classified, and we will name the model and the version. Specify a motor for my drive →
All seven air motors compared
The motors are designed to run at 5 to 7 bar. The figures below were measured at 6 bar. Power is quoted at maximum efficiency; torque is given at the speed where the motor delivers that power, at start-up, and at stall.
Open the full motor table
| Model | Power | No-load speed | Speed at max power | Torque at max power | Starting torque | Stall torque | Air consumption | Weight | Air intake |
|---|---|---|---|---|---|---|---|---|---|
| Axial piston (EP) | |||||||||
| EP20 | 0.8 kW (1.1 HP) | 3,000 rpm | 1,650 rpm | 4.7 Nm | 6.6 Nm | 9.4 Nm | 21 l/s (1.26 m³/min) | 5.5 kg | G 3/8 inch |
| EP40 | 1.6 kW (2.2 HP) | 2,800 rpm | 1,400 rpm | 11 Nm | 15.4 Nm | 22 Nm | 30 l/s (1.80 m³/min) | 11.3 kg | G 1/2 and 3/8 inch |
| EP80 | 2.1 kW (2.8 HP) | 2,000 rpm | 1,100 rpm | 17.9 Nm | 25.1 Nm | 35.8 Nm | 33 l/s (1.98 m³/min) | 12.7 kg | G 1/2 and 3/8 inch |
| EP120 | 2.6 kW (3.5 HP) | 1,600 rpm | 880 rpm | 24.2 Nm | 34 Nm | 48.4 Nm | 37 l/s (2.22 m³/min) | 18.4 kg | G 1/2 and 3/8 inch |
| Vane (ZM / STRC) | |||||||||
| ZM10 | 1.6 kW (2.2 HP) | 7,000 rpm | 3,850 rpm | 3.9 Nm | 5.5 Nm | 7.8 Nm | 33 l/s (1.98 m³/min) | 6.3 kg | G 1/2 inch |
| ZM80 | 2.6 kW (3.5 HP) | 6,000 rpm | 3,300 rpm | 7.5 Nm | 10.4 Nm | 15 Nm | 45 l/s (2.70 m³/min) | 8.1 kg | G 1/2 inch |
| STRC1650 | 1.1 kW (1.5 HP) | 7,000 rpm | 3,850 rpm | 2.7 Nm | 3.8 Nm | 5.4 Nm | 25 l/s (1.50 m³/min) | 5.4 kg | G 1/2 inch |
The EP and ZM motors run in either direction, so which port is the inlet and which is the exhaust depends on the direction you connect them for. STRC1650 turns one way only, and which way is fixed by how the air-inlet centre body is assembled, so it can be built to run in either direction. Stall torque is the figure to size against for a load that can jam: an air motor can sit stalled indefinitely without damage.
Scroll the table sideways to see every column.
Three versions: underground ATEX, surface ATEX, standard
Every model in both families is built in three versions. The motor is the same machine; what differs is the certification it carries and the conditions it is approved for. The version has to be named when the motor is specified, so settle the area first.
Underground, ATEX certified
For underground mining and tunnelling, where gas can collect in the working. The operating procedure belongs with it: start the motor at about 10 percent speed to clear any gas that has gathered before running it normally, and do not start it at all where methane in the area is above 10 percent.
Surface, ATEX certified
For above-ground areas classified as explosive atmospheres in the site explosion-protection document: gas and dust zones in chemical, fuel, paint, grain and similar plants. Carries the ATEX marking and the EU declaration of conformity, which is what your own conformity file needs.
Standard use
The same motor without ATEX certification, for areas that are not classified. Lower price, and identical in dimensions, output, mounting and connections, so it can be specified into the same machine design.
Installing an ATEX version
A grounding connection is mandatory: an insulated single-core cable of at least 6 mm² cross-section, bolted to the rear cover with the paint cleaned off the contact face so the connection is continuous. The motor is finished in anti-static paint, and any chip or scratch that exposes bare metal has to be touched in. Air is fed through a hose of at least 1/2 inch, and the filter and lubricator are checked before every shift. These are conditions of the certification, not recommendations.
Whether an area is classified is decided by the site operator, not by the supplier. Tell us what is handled and where the motor will sit and we will tell you which of the three applies. Our article on ATEX pneumatic motors for hazardous environments sets out the differences in more detail.
Gear reducers
An air motor's useful speed is usually higher than the machine's, so the reducer is where the specification is finished rather than an accessory bolted on afterwards. Three geometries. The parallel shaft unit sits in line with the motor in a compact pear-shaped housing and offers 1:20, 1:25, 1:30 and 1:40, accepting up to 3,000 rpm at the input. The ZR10-1000 worm reducer turns the drive through 90 degrees at 25:1, which is what you want when there is no room behind the motor. The RR10-1000 planetary runs coaxially at 24:1 and spreads the load across its planet gears, which suits continuous duty and reversing work.
Send the output torque and the shaft orientation your machine needs, and we will confirm the motor and reducer combination and the input speed it will see. Match a reducer to my motor →
The three reducers side by side
| Reducer | Model | Ratio | Output geometry | Max input speed |
|---|---|---|---|---|
| Parallel shaft | - | 1:20, 1:25, 1:30, 1:40 | In-line with the motor | 3,000 rpm |
| Worm gear | ZR10-1000 | 25:1 | Right angle, 90 degrees | - |
| Planetary | RR10-1000 | 24:1 | Coaxial, 180 degrees | - |
All three are reductions, though the published notation differs: 1:20 and 25:1 both mean the output turns slower than the input. The parallel shaft unit accepts up to 3,000 rpm at the input, which covers every EP motor and the ZM80 at reduced speed; the vane motors reach 6,000 to 7,000 rpm free-running, so check the input speed when pairing. A maximum input speed is not published for the worm and planetary units, so tell us the motor you intend to drive them with and we will confirm it rather than let you assume. Tell us the output torque and shaft orientation you need and we will confirm the combination.
Scroll the table sideways to see every column.
How to choose
Seven motors and three reducers is a small catalogue, and these six points will get you to the right combination without a conversation.
Piston or vane?
Torque or speed, and the kW rating will not tell you which. The EP120 and the ZM80 are both 2.6 kW, but the vane gives 7.5 Nm at 3,300 rpm and the piston 24.2 Nm at 880 rpm. If the load is heavy and slow, take the piston. If the load is light and the speed is the point, take the vane, and take the weight saving with it.
Size against stall torque, not rated torque
Stall torque is roughly twice the torque at maximum power: 48.4 Nm on EP120, 15 Nm on ZM80. If the load can jam, that is the number that decides whether the drive holds or gives up, and sizing on rated torque alone will leave you short exactly when it matters. This is the single most common specification error we see.
Check the air supply before the motor
Consumption runs from 21 l/s on EP20 to 45 l/s on ZM80 at 6 bar, which is 1.26 to 2.7 m³/min per motor, at a working pressure of 5 to 7 bar. An undersized compressor or a long thin hose costs pressure at the motor, and a motor running below 5 bar will not give the figures in the table. Count every motor on the line, not the biggest one.
The filter and lubricator are part of the motor
Not optional extras. Air that arrives dirty or dry will wear the motor out early whatever else you do right. Set the lubricator to about two drops a minute and use a thin machine oil rated from -15 to +150 degrees. On an ATEX installation, checking both before every shift is a condition of the certification rather than good practice.
Vane motors have one wear part
The vanes themselves. They are a consumable, replaced at roughly every 5,000 running hours, and the job is straightforward. That is worth knowing at the specification stage rather than discovering later: a vane motor is cheaper and lighter for its speed, and it asks for this one piece of maintenance in return. Piston motors have no equivalent consumable.
Add a reducer when torque matters more than speed
A 1:40 parallel shaft unit behind an EP80 turns 17.9 Nm into roughly 700 Nm at about 28 rpm, before losses. That is a different machine from the motor on its own. Decide the output first, in torque and rpm at the driven shaft, then work back to the motor and ratio rather than picking a motor and hoping a reducer will rescue it.
Designing a machine around it?
Then the useful thing to settle early is the mounting and the port positions, because all three versions are identical in dimensions, output, mounting and connections. You can design once and decide the certification later, which is worth knowing if the area classification is still being argued about when the drawings are due.
Replacing a motor already in service?
Send us what is there: the frame, the shaft, the mounting, and what the machine actually does rather than the old nameplate. Electric and pneumatic kW ratings are not comparable and matching them will give you the wrong motor. We match at the shaft, on torque and speed, which is the only comparison that holds.
Send the torque and speed you need at the driven shaft, what the load does when it jams, and whether the area is classified. We come back with the motor, the version, the reducer and the air it needs.
Specify my driveWhere these motors are working
The common thread is not the industry. It is that something about the drive rules out an electric motor: it can jam, the atmosphere is classified, it gets washed down, or the weight matters.
Technical insightVane or axial piston?Two architectures, two very different torque and speed curves from the same kW rating. How each one converts compressed air into rotation, and which applications suit which.Read the comparison 
Technical insightATEX in hazardous areasUnderground, surface and standard: what separates the three certification variants, what the installation conditions actually require, and how to get the version right at the specification stage.Read the certification guide 
Technical insightDesigning the air networkWhere pressure goes between the compressor and the motor, and why a drive that looks correctly specified on paper underperforms on site. Pipe sizing, losses and layout.Read the design guide Frequently asked questions
What is a pneumatic motor used for?
Anywhere a rotating drive is needed and an electric motor is awkward: loads that can jam and must be held rather than tripped, areas classified for gas or dust, wet or washdown environments, and portable or hoisted equipment where weight decides the design. Mixers, winches, hoists, conveyors, valve actuators, pumps and agitators are the usual applications. Where an ordinary electric drive would be allowed and left alone, it is usually the cheaper answer, and we will say so.
What is the difference between an axial piston and a vane air motor?
Torque against speed, and the kW rating hides it. The EP120 and the ZM80 are both 2.6 kW: the piston motor gives 24.2 Nm at 880 rpm and the vane gives 7.5 Nm at 3,300 rpm. Piston motors drive a swashplate and suit heavy, slow loads; vane motors spin a bladed rotor, run to 7,000 rpm free, weigh less and have one consumable wear part. Pick on what the shaft has to do, not on power.
Which of the three versions do I need?
That depends on how the area is classified, and classification is the site operator's decision, not the supplier's. Underground ATEX is for mining and tunnelling where gas can collect; surface ATEX is for above-ground gas and dust zones named in the site explosion-protection document; standard is for areas that are not classified. All three are identical in dimensions, output, mounting and connections, so the machine design does not change with the version. Tell us what is handled and where the motor sits and we will tell you which applies.
What does an ATEX installation require?
A mandatory grounding connection: an insulated single-core cable of at least 6 mm² cross-section, bolted to the rear cover with the paint cleaned off the contact face so the connection is continuous. The anti-static paint finish must be kept intact, with any chip or scratch exposing bare metal touched in. Air is fed through a hose of at least 1/2 inch, and the filter and lubricator are checked before every shift. These are conditions of the certification rather than recommendations.
How much compressed air does an air motor need?
At 6 bar: EP20 21 l/s, EP40 30 l/s, EP80 33 l/s, EP120 37 l/s, ZM10 33 l/s, ZM80 45 l/s and STRC1650 25 l/s. In cubic metres per minute that is 1.26 to 2.7. Working pressure is 5 to 7 bar. Size the compressor on the sum of every motor that runs at once plus headroom for hose losses, not on the largest one, and remember that a motor fed below 5 bar will not produce the figures in the table.
Can an air motor be stalled or overloaded?
It can be stalled, indefinitely, with no damage. That is the defining advantage over an electric motor, which burns out. The motor simply stops, holds its torque and resumes when the load clears. This is why stall torque is the figure to size against on anything that can jam: about twice the torque at maximum power, so 48.4 Nm on the EP120 and 15 Nm on the ZM80.
Can the direction of rotation be reversed?
On the EP and ZM motors, yes: they run in either direction, so which port is the inlet and which is the exhaust depends on how you connect them. The STRC1650 turns one way only, and the direction is fixed by how the air-inlet centre body is assembled, which means it can be built to run either way but not switched afterwards. Say which way you need it when you order that model.
How loud is an air motor?
Measured at the exhaust with no silencer fitted, about 105 dB on the piston motors and about 106 dB on the vane motors. With a suitable silencer, about 72 dB and about 70 dB. The silencer is the whole story on noise here, so if the working environment has a limit, fit one and specify it as part of the drive rather than treating it as an accessory.
Can an air motor replace an electric motor already installed?
Often, but not by matching the nameplate. Electric and pneumatic kW ratings are not comparable, and matching them gives the wrong motor. Send us the frame, the shaft, the mounting and a description of what the machine actually does, and we will match on torque and speed at the shaft. You will also need an air supply at the machine, which is the part that most often decides whether the swap is worth doing.
Which reducer fits which motor?
The parallel shaft reducer accepts up to 3,000 rpm at the input, which covers every EP motor and the ZM80 at reduced speed. The vane motors reach 6,000 to 7,000 rpm free-running, so the input speed has to be checked when pairing them. A maximum input speed is not published for the worm ZR10-1000 and the planetary RR10-1000, so tell us the motor you mean to drive them with and we will confirm the combination rather than have you assume it.
What warranty and service come with the motor?
One year from the invoice date, covering the whole motor including all its parts. The motors are made entirely in Turkiye by SET-A MAKINA, which is why parts and technical answers come from the people who built them rather than through a distributor.
Related categories and reading
Tell us the load, not the model
The torque and speed you need at the driven shaft, what the load does when it jams, how the area is classified, and what air you have available. We come back with the motor, the certification version, the reducer and the compressor it needs. If an ordinary electric drive would do the job, we will tell you that instead.