Oil-free rotary tooth
Oil-free rotary tooth compressor - contactless stainless rotors, 100% oil-free air, ISO 8573-1 Class 0 TÜV-certified. 15 to 55 kW, fixed or VSD, for pharma, food and electronics.
14 models in the catalogue, flow 2.3 - 8.6 m³/min, pressure 7.5 - 10 bar, noise level 80 - 85 dB(A).
How it works ↓
What is a rotary tooth compressor?
Two claw-shaped rotors turn in opposite directions without touching each other or the casing, synchronised by gears: no oil in the chamber. In the catalogue, its class 0 is certified by a TÜV test. It takes over from the scroll for medium flows, at fixed or variable speed.
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Made for
- Pharmaceuticals, food, electronics, laboratories
- Medium oil-free flows, when the scroll is too small
- Demand that moves: half the models have a drive
Not made for
- More than 10 bar oil-freeOil-free water-injected screw
- Large flowsOil-free dry screw
| Reference | kW | Flow by pressure (m³/min) | dB(A) | Outlet | L × W × H (mm) | Weight |
|---|---|---|---|---|---|---|
| CZ-RM-15A | 15 | 7.5 bar2.38.6 bar2.110 bar1.8 | 80 | G1" | 1636 × 1015 × 1638 | 1,150 kg |
| CZ-RM-15VSD-A | 15 | 7.5 bar0.92-2.38.6 bar0.84-2.110 bar0.72-1.8 | 80 | G1" | 1636 × 1015 × 1638 | 1,200 kg |
| CZ-RM-18A | 18.5 | 7.5 bar2.98.6 bar2.710 bar2.2 | 80 | G1" | 1636 × 1015 × 1638 | 1,170 kg |
| CZ-RM-18VSD-A | 18.5 | 7.5 bar1.16-2.98.6 bar1.08-2.710 bar0.88-2.2 | 80 | G1" | 1636 × 1015 × 1638 | 1,220 kg |
| CZ-RM-22A | 22 | 7.5 bar3.68.6 bar3.210 bar2.7 | 80 | G1" | 1636 × 1015 × 1638 | 1,181 kg |
| CZ-RM-22VSD-A | 22 | 7.5 bar1.44-3.68.6 bar1.28-3.210 bar1.08-2.7 | 80 | G1" | 1636 × 1015 × 1638 | 1,240 kg |
| CZ-RM-30A | 30 | 7.5 bar4.78.6 bar4.410 bar3.7 | 85 | DN40 | 1636 × 1015 × 1850 | 1,458 kg |
| CZ-RM-30VSD-A | 30 | 7.5 bar1.88-4.78.6 bar1.76-4.410 bar1.48-3.7 | 85 | DN40 | 1636 × 1015 × 1850 | 1,490 kg |
| CZ-RM-37A | 37 | 7.5 bar5.88.6 bar5.510 bar4.8 | 85 | DN40 | 1636 × 1015 × 1850 | 1,460 kg |
| CZ-RM-37VSD-A | 37 | 7.5 bar2.32-5.88.6 bar2.2-5.510 bar1.92-4.8 | 85 | DN40 | 1636 × 1015 × 1850 | 1,510 kg |
| CZ-RM-45A | 45 | 7.5 bar6.98.6 bar6.510 bar5.7 | 85 | DN40 | 1636 × 1015 × 1850 | 1,465 kg |
| CZ-RM-45VSD-A | 45 | 7.5 bar2.84-7.18.6 bar2.76-6.910 bar2.6-6.5 | 85 | DN40 | 1636 × 1015 × 1850 | 1,520 kg |
| CZ-RM-55A | 55 | 7.5 bar8.68.6 bar8.310 bar7.4 | 85 | DN40 | 1636 × 1015 × 1850 | 1,723 kg |
| CZ-RM-55VSD-A | 55 | 7.5 bar3.44-8.68.6 bar3.32-8.310 bar2.96-7.4 | 85 | DN40 | 1636 × 1015 × 1850 | 1,770 kg |
Flows, pressures, noise levels and dimensions recorded model by model on the catalogue sheets. Flows given at 8 bar.
Two tooth rotors turning without touching, no oil in the chamber: the contact-free technology of medium flows, from 15 to 55 kW, when the scroll is too small and the dry screw too big. It holds second place in the house order of preference.
Its pressure tops out at 10 bar: for an oil-free network at 13 bar, see the water-injected oil-free screw.
Two claw-shaped rotors turn in opposite directions without ever touching, separated by a clearance of a few hundredths of a millimetre. Precision timing gears maintain this gap: nothing rubs in the compression chamber, so nothing wears there and no oil enters it.
The oil stays confined to the drive casing, separate from the chamber. The air produced is certified Class 0 according to ISO 8573-1, backed by a TÜV test: it is not a treatment chain that achieves it, it is the machine itself.
Compression takes place in two steps: a first block brings the air to an intermediate pressure, a cooler takes out the heat, and a second block finishes the work. That is what makes it possible to reach 10 bar without a drop of oil, where a single set of rotors would top out much lower.
The catalogue covers 15 to 55 kW, from 2.3 to 8.6 m³/min, from 7.5 to 10 bar, at fixed speed or with PM-VSD variable speed. Below that, the scroll holds up to about 5 m³/min; above, the dry screw takes over, then the centrifugal for large flows.
Pharmacy, food processing, electronics, laboratory, textiles: the processes whose specification says Class 0, and not merely clean air. Fourteen models, half of them variable speed for workshops whose demand fluctuates.
TÜV-certified Class 0
ISO 8573-1 Class 0 achieved by the machine, verified by a TÜV test: the proof does not depend on the filtration installed downstream.
Nothing touches
Stainless steel rotors separated by a calibrated clearance, held by timing gears: no friction in the chamber, and therefore no wear.
From 15 to 55 kW
2.3 to 8.6 m³/min, from 7.5 to 10 bar. Beyond that, several units are installed in parallel or you move to the dry screw.
PM-VSD version
Permanent-magnet variable-speed motor available across the whole range: the machine follows demand instead of running unloaded.
Our order of preference for Class 0
When a specification says Class 0, CEZIUM quotes an oil-free machine, as the trade understands it: scroll compressor up to 5 m³/min, rotary tooth compressor from 2.3 to 8.6 m³/min, dry screw or centrifugal beyond that. We also point out the alternative few suppliers mention: a lubricated screw followed by a treatment chain delivers oil-free air for a markedly lower purchase price, without carrying the Class 0 label.
In this trade, Class 0 means an oil-free machine. That is the convention, and it is what a specification expects when it writes Class 0, so that is what we quote. Technically, ISO 8573-1 classifies air at the point of use rather than the compressor, so a lubricated screw followed by multi-stage filtration and an adsorption dryer delivers oil-free air measured on acceptance. That is a genuine alternative, cheaper to buy and far better at heat recovery, but it does not give you a Class 0 certified machine. Both are worth knowing; your own documents decide.
| Rank | Technology | Catalogue flow | Power | Class 0 | Recoverable heat | Purchase cost |
|---|---|---|---|---|---|---|
| 01 | Scroll compressor | 0.3 to 4.96 m³/min | 2.2 to 45 kW | Oil-free machine | Low | Moderate |
| 02 | Rotary tooth compressorthis page | 2.3 to 8.6 m³/min | 15 to 55 kW | Oil-free machine | Low | High |
| 03 | Dry screw compressor | 6.8 to 43 m³/min | 45 to 250 kW | Oil-free machine | Limited | Very high |
| 04 | Centrifugal compressor | 48 to 3,000 m³/min | 198 to 12,055 kW | Oil-free machine | High | Very high |
| 05 | Lubricated screw + treatment chain | 0.95 to 44 m³/min | 5.5 to 250 kW | Treated air, no label | High | Low |
Flow rates and power ratings taken from the CEZIUM catalogue, oil-free technologies and variable-speed lubricated screw. Purchase cost is given in relative ranks, at comparable flow.
- 01
Scroll compressor
Up to 5 m³/minThe first choice below 5 m³/min: oil-free by design, quiet, compact. The right format for a laboratory, a dental practice or a small production line.
See the 13 catalogue models - 02
Rotary tooth compressor
2.3 to 8.6 m³/minAbove the scroll range and up to 8.6 m³/min. The rotors never touch: no friction inside the chamber, minimal wear, TÜV-certified Class 0. Beyond that flow, several units run in parallel.
See the 14 catalogue models - 03
Dry screw compressor
7.8 to 46 m³/minThe answer at high flow when the specification says Class 0. We also state its downside: it costs a great deal to buy and lends itself poorly to heat recovery. If your documents ask for oil-free air rather than a certified machine, the previous step is worth quoting alongside.
See the 20 catalogue models - 04
Centrifugal compressor
From 48 m³/minReserved for the continuous base load of very large sites, where no screw compressor can carry the flow in a single machine.
See the 11 catalogue models - 05
Lubricated screw + treatment chain
Alternative, above 8.6 m³/minThe alternative, when your specification asks for oil-free air rather than a certified machine: multi-stage filtration and an adsorption dryer behind a lubricated screw, with acceptance measurement at the point of use. Markedly lower purchase price, and compression heat is recovered from the oil circuit, which a dry machine does poorly. Rule it out if your documents say Class 0.
See the 33 catalogue models
Worth reading on this technology
Lubricated screw or oil-free compressor: Class 0 describes the air, not the machine
Most comparisons set two machines against each other. The standard, however, judges the air at the point of use. A lubricated screw followed by a treatment chain can deliver oil-free air at the point of use, at a significantly lower purchase cost; class 0 itself remains that of an oil-free machine. Here is the order in which CEZIUM selects each technology.
ISO 8573-1: the complete guide to compressed air quality classes
ISO 8573-1 grades compressed air quality against three criteria, particles, water and oil, each on its own scale starting at Class 0. Which class suits which application? Full table and examples.