Variable Speed Scoop Coupling — Type SC
Stepless speed variation in a wide range from a fixed-speed motor — the energy-saving way to control fans, pumps, conveyors and crushers.
Speed control by oil, not by throttle.
Fluidomat-SC is a variable-speed fluid coupling that provides stepless speed variation over a wide range when connected to a fixed-speed electric motor. Speed is varied by changing the oil filling in the coupling through a sliding scoop tube while in operation.
It responds to electric, pneumatic, hydraulic or manual signals, and offers all the advantages of a constant-speed coupling — load limiting, absorption of shocks and torsional vibration, smooth acceleration — with built-in safety that makes it fool-proof in operation. SC gives no-load motor starting, controlled starting torque, continuous declutching, stepless speed variation and synchronising of motors in multi-drive units.
Key data
Why engineers specify Fluidomat-SC
- Self-supported stationary housing — no weight on driving or driven shafts, no extra load on motor or machine bearings
- Rugged design for all site conditions; rotating mass not exposed
- Higher misalignment capacity and a choice of flexible couplings
- Continuous declutching possible, with the motor still running
- Very low vibration and noise level
- Easy mounting of controls, oil connections and sensors
- Scoop tube governed easily in auto or manual mode for speed control
- Labyrinth shaft seals ensure no leakage from shaft ends; easy maintenance via top cover
How scoop control works
The sliding scoop tube governs the oil level in the working circuit between 0% and 100%. By varying the oil level, the torque-transmission capacity changes — altering the slip and giving stepless speed variation over a wide range. Heat generated in the coupling is carried away by circulating oil, cooled by an oil cooler in the circuit.
Fluidomat-SC gives stepless speed regulation of 5:1 for centrifugal loads (fans, pumps), 2:1 for constant-torque loads (conveyors) and 1.4:1 for rising-torque loads — and is ideal for continuous declutching of the machine while the motor runs.
Energy saving through SC
In centrifugal machines, discharge is proportional to speed — and power demand falls with the cube of speed. Throttle control wastes energy and wears the pump or fan; speed control with an SC coupling can cut power by 10–40%. Because the motor starts on no load, it can be rated for consumed power, not starting duty — and rugged squirrel-cage motors replace costly slip-ring machines.
Rating table — Scoop-controlled couplings
Maximum ratings in KW at different input speeds (RPM). For final selection, please consult Fluidomat application engineering.
| Model | 500 | 600 | 750 | 900 | 1000 | 1200 | 1500 | 1800 | 3000 | 3600 |
|---|---|---|---|---|---|---|---|---|---|---|
| SC-7 | — | 5 | 10 | 17 | 23 | 39 | 75 | 100 | — | — |
| SC-8 | — | 7 | 14 | 24 | 32 | 56 | 100 | 173 | — | — |
| SC-9 | — | 13 | 25 | 44 | 60 | 104 | 205 | 300 | — | — |
| SC-10 | — | 25 | 49 | 85 | 116 | 200 | 350 | 425 | — | — |
| SC-11A | 20 | 35 | 68 | 118 | 162 | 280 | 500 | 680 | — | — |
| SC-11 | 29 | 51 | 100 | 172 | 236 | 408 | 725 | 1100 | — | — |
| SC-12 | 52 | 90 | 176 | 304 | 416 | 720 | 1250 | 2000 | — | — |
| SC-13 | 74 | 128 | 250 | 432 | 592 | 1024 | 1700 | 2300 | — | — |
| SC-880 | 111 | 192 | 375 | 648 | 890 | 1600 | 2300 | 2600 | — | — |
| SC-14 | 252 | 435 | 850 | 1468 | 1850 | 2300 | — | — | — | — |
| SC-14-233-2 | 326 | 563 | 1100 | 1525 | 2090 | 3000 | — | — | — | — |
| SC-16 | 740 | 1280 | 2500 | 3300 | 3500 | — | — | — | — | — |
| SC-1330 | 1250 | 1800 | 3000 | 3500 | — | — | — | — | — | — |
| SC-390-233-2-G | — | — | — | — | — | — | — | 70 | 300 | 400 |
| SC-422-233-2-G | — | — | — | — | — | — | — | 132 | 480 | 600 |
| SC-500-233-2-G | — | — | — | — | — | — | — | 275 | 1250 | 1500 |
| SC-580-233-2-G | — | — | — | — | — | — | — | — | 2400 | 2800 |
| SC-580-311-2-G | — | — | — | — | — | — | — | 511 | 3000 | 3300 |
| SC-630-311-2-G | — | — | — | — | — | — | — | 1012 | 4600 | — |
Ratings in KW at the stated input speed (RPM). High-speed 3000/3600 RPM models are for boiler feed pump duties; couplings at these speeds should be selected only after Fluidomat approval.
Dimensions
Technical specification and overall / mounting dimensions (mm) with oil quantity by model.
| S.No | Model | B | C | A1 C/C | A2 C/C | W1 | W2 | CH | H1 | Oil qty (L) |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | SC-7 | 855 | 185 | 370 | 680 | 630 | 630 | 475 | 276 | 60 |
| 2 | SC-8 | 810 | 179 | 360 | 915 | 835 | 835 | 493 | 287 | 94 |
| 3 | SC-9 | 1015 | 213 | 440 | 915 | 835 | 835 | 575 | 350 | 114 |
| 4 | SC-10 | 1137 | 207 | 560 | 1075 | 1000 | 1000 | 610 | 409 | 160 |
| 5 | SC-11A | 1150 | 212 | 560 | 1075 | 1000 | 1000 | 610 | 409 | 160 |
| 6 | SC-11 | 1261 | 257 | 590 | 1240 | 1100 | 1100 | 630 | 431 | 189 |
| 7 | SC-12 | 1267 | 272 | 590 | 1240 | 1100 | 1100 | 745 | 500 | 270 |
| 8 | SC-12 | 1310 | 289 | 590 | 1240 | 1100 | 1100 | 745 | 500 | 270 |
| 9 | SC-13 | 1398 | 290 | 650 | 1390 | 1250 | 1250 | 815 | 505 | 339 |
| 10 | SC-13 | 1429 | 305 | 650 | 1390 | 1250 | 1250 | 815 | 505 | 339 |
| 11 | SC-880 | 1552 | 282 | 750 | 1650 | 1500 | 1500 | 1000 | 569 | 456 |
| 12 | SC-14 | 1640 | 341 | 850 | 1800 | 1600 | 1600 | 1000 | 650 | 612 |
| 13 | SC-16 | 1950 | 430 | 940 | 1800 | 1800 | 1600 | 1060 | 760 | 864 |
| 14 | SC-1330 | 1950 | 328 | 1126 | 2020 | 1800 | 1800 | 1160 | 830 | 1296 |
| 15 | SC-390-233-2-G | 915 | — | 370 | 680 | 630 | 630 | 575 | 417 | 90 |
| 16 | SC-422-233-2-G | 1110 | — | 450 | 750 | 850 | 650 | 630 | 330 | 140 |
| 17 | SC-500-233-2-G# | 1145 | 126 | 760 | 1000 | 624 | 1780 | 630 | 350 | 235 |
| 18 | SC-500-233-2-G | 1200 | 126 | 600 | 1240 | 1000 | 1200 | 660 | 350 | 235 |
| 19 | SC-580-233-2-G# | 1255 | 131 | 860 | 1000 | 706 | 1780 | 800 | 430 | 400 |
| 20 | SC-580-311-G# | 1255 | 131 | 860 | 1000 | 706 | 1780 | 800 | 430 | 400 |
| 21 | SC-580-233-2-G-FL | 1358 | 215 | 744 | 1410 | 1260 | 1260 | 800 | 430 | 400 |
| 22 | SC-580-311-G-FL | 1358 | 215 | 744 | 1410 | 1260 | 1260 | 800 | 430 | 400 |
| 23 | SC-630-311-G** | 1485 | 322 | 640 | 1400 | 1250 | 1250 | 900 | 450 | 600 |
* Oil quantity is for the coupling; pipeline, cooler & filter extra. Dimensions marked ** are approximate. # As per Figure 2.
Energy saving — fan power vs speed
Typical fan and Fluidomat-SC power-speed characteristics showing the power recovered by speed control instead of throttling.
| % fan speed | Fan HP | Coupling input HP | Diff. loss |
|---|---|---|---|
| 100 | 1000 | 1030 | 30 |
| 90 | 729 | 810 | 81 |
| 80 | 512 | 640 | 128 |
| 70 | 343 | 490 | 147 |
| 66.6 | 296.3 | 444.4 | 148.1 |
| 60 | 216 | 360 | 144 |
| 50 | 125 | 250 | 125 |
| 40 | 64 | 160 | 96 |
| 30 | 27 | 90 | 63 |
| 20 | 8 | 40 | 32 |
Fan power falls with the cube of speed while coupling input power tracks the driven load plus slip loss — the difference is the power saved against damper/throttle control.
Diagrams & views
Proven across rotating equipment
How much could speed control save you?
Send us your fan or pump duty and we’ll estimate the energy a Fluidomat-SC coupling could recover.