Simple, compact, lightweight design, easy to maintain | Complex, heavy design |
Low maintenance; continuous cleaning and cooling in a closed, 100% filtered system (filtered to 10 microns) | Unfiltered, uncooled closed system; retains all wear debris possibly shortening the gear box life |
No gears, uses only slow-moving parts; creates less friction | Multiple gears and moving parts at higher speeds; creates more friction and higher power consumption |
Scroll can run leading or lagging (optimized performance) at all speeds and torque ranges | Limited to a one-direction process |
No overheating of the hydraulic motor due to automatic, continuous heat dissipation through the oil conditioning system | External cooling often required; overheating is a common problem |
Perfect lubrication at high speed | Reduced lubrication caused by centrifugal forces and splashing losses |
Excellent weight/torque ratio, about half the weight of gearbox with same torque capacity | Gearbox about twice the weight of ROTODIFFwith same torque |
Lower overhung weight reduces both load on main bearings and machine vibration (less wear on bearings). Less weight means reduced power input | Heavy overhung gear increases load and heat on main bearing, causing reduced bearing life and more vibrations. More weight requires more power to operate |
All mechanical components are protected against overload by various safeguards and finally protected by simple pressure relief valve (higher torque capacity) | Repeated high shock loads will damage and destroy in-line components and cause premature failure (Cyclo gear reduced torque capacity at higher differential speed) |
One set of V-belts to drive the bowl | Multiple sets and types of belts |
Versatile design for multiple application | Limited design requires different units for each application |
Full range of differential speeds at all bowl speeds, including zero RPM, start-up, shutdown and standstill | Limited range of differential speeds at lower bowl speeds and standstill |
Robust and reliable; process control with direct torque reading. The direct measurement of scroll torque and speed allows immediate responseto process changes | Complicated calculations of different speeds through multiple gear reductions, increase errors and dramatically slows response to process changes |
Simple and accurate measurement of scroll speed; provides precise control of differential with unlimited bowl speed options Differential = speed of ROTODIFF | Complicated, indirect measurement of scroll speed; calculated from bowl and pinion speed, gearbox ratio and control error Differential = (bowl speed and pinion speed) gear box ratio |
Low energy consumption; power is not lost or wasted. Scroll drive ROTODIFF operates independently from the main drive motor | Increased energy cost; gearbox design steals energy from the main drive |
No drag or parasitic loss on the main drive; uses only the energy required to convey solids | Robs energy from main drive; torque adds braking horsepower; increases drag on main drive motor |
Reduction or elimination of Chatter or Slip Stick | Chatter or Slip Stick damages gear box |
Versatile use also in Ex-proof areas (ATEX) | Limitations on the control system or expensiv installation costs if used in Ex-proof areas (ATEX) |