The drive arrangement between the motor and the airend shapes a rotary screw compressor in efficiency, reliability and footprint. Geared and direct drive designs each have advantages, and the right choice depends on size, duty and site conditions.
Direct drive
- Motor and airend on one shaft
- No gear losses
- Fewer wearing components
- Compact and quiet
Geared drive
- Gearbox matches motor and airend speed
- Flexible speed matching on large machines
- Easier service access to components
- Small efficiency loss in the gearbox
Choosing
For small and mid-sized machines, direct drive is usually the cleanest solution with high efficiency and low maintenance. On large compressors, gearing allows a compact high-speed airend with a standard motor, but adds lubrication and service points.