Having compressed air available in a workshop can be extremely useful. Having a compressor isn’t such a pleasure though, because unless it’s a very expensive model, it will be one of the noisier devices you own. Other than putting your compressor outside, is there a solution to the noisy side of having an air line? [Dominik Meffert] may have found one for his CNC plasma cutter in the shape of a rack of much quieter fridge compressors arranged in parallel with an air tank.
Of course, there’s nothing new about using a fridge compressor in the workshop. Indeed, such units are even commercially available as compressors for low-capacity tasks such as airbrushing. But we’ve never seen so many at once. It’s not entirely apparent how he’s handling the replacement of any lubricating oil that’s being caught in his filters, and we hope the refrigerant was disposed of safely, but we can see he’s on to something.
Fridge compressors have appeared here many times over the years, for more than compressing, we’ve even seen one as an engine. They aren’t always as strongly built as they should be though.
Probably one of the most reliable devices you will have in your house is the refrigerator, as its compressor has the minimum of moving parts and carries its own lubrication. It’s not uncommon to find fridges many decades old still in use, and fridges are far more likely to be discarded due to broken fittings rather than a failed compressor. An interesting teardown of a failed fridge compressor comes from [turbokinetic], who gives us a professional analysis of how shortcomings in its construction caused it to fail. It’s both an opportunity for a look at the inside of a fridge compressor, and a commentary on the quality of consumer grade hardware.
Electrically the unit seemed unhurt, but the motor wouldn’t pump anything. Cutting the lid off revealed the motor, and it was soon established that the bearing had failed. As the teardown proceeded the conclusion was that the fault lay in the oil being too low viscosity. The designer had picked a very light oil in pursuit of low friction for lower energy consumption, but had ended up with one too light to provide adequate coverage within the bearing. The compressor has a lifetime of around ten years baked into it from manufacture, whether the designer intended it to or not.
You can see the full video below the break, but meanwhile this isn’t the first fridge compressor we’ve seen.
Continue reading “Fridge Compressor Teardown Reveals Engineering Compromises”