The Sawafuji compressor is highly regarded by many manufacturers of high-end refrigeration systems. Most quality refrigerators make use of a compressor driven refrigeration cycle, but not all compressors are equal.
The chief selling point of a Sawafuji reciprocating compressor is its use of the ‘swing motor’. So what makes a swing motor different to the average motor, and what makes it so successful in refrigeration applications?
Sawafuji Swing Motor Characteristics
The normal source of dynamic power in a compressor is an electrical motor with a rotating main axis. In contrast to this, the swing motor utilizes vibrations, which have the coil connected straight to the piston (the compressor).
When a coil bearing alternating current is applied at a 90-degree angle to the magnetic field, thrust results per John Ambrose Fleming’s left hand rule. Due to the layout of the motor, this thrust transfers to the piston; which then performs the intake and compression cycles.
Merely using the thrust provided to compress the refrigerant will not work however, the amplitude of the motion will not be sufficient. For this reason, the swing motor is configured to synchronize the frequency of the current with frequency of the oscillation occurring within the system. Utilizing this resonance the motor is able increase the amplitude sufficiently to provide an adequate level of compression of the refrigerant.
Low Amperage Startup
One great attribute of the swing motor and hence the Sawafuji compressor is that is does not require a large surge of current at startup time. Even if the first few strokes of the piston are not sufficient to fully compress the refrigerant, the motor will still fire up and the resonance phenomenon will soon kick in.
Minimal Moving Parts
The Sawafuji swing motor is extremely reliable. This is because it only contains one moving part. There are no bearings or cranks only the piston which means there is very little that can break
The Sawafuji compressor is very energy efficient. With minimal moving parts there is very little energy lose to friction. Combine this with its low current draw at startup and it is easy to see that this compressor is very valuable in situations where power is limited.
The Danfoss compressor the chief competitor to the Sawafuji also has its fans; they are in many Waeco fridges. However, the manufacturer Engel remains steadfastly convinced of the benefits of Sawafuji technology.