Pressure and Volume

A positive displacement oil pump including all spur gear and Gerotor designs pushes the same amount of fluid with each revolution of its input shaft. Theoretically, if the speed of the pump is doubled, twice as much oil is pumped. However, this principle applies only up to that point at which cavitation starts. Cavitation occurs when the pump tries to suck the oil faster than it can enter the pump, and a higher vacuum is created, causing more gas bubbles to form. Simplistically put, if you double the pressure on a bubble its volume gets cut roughly in half. Double the pressure again and the bubble shrinks by half. At some point, the bubble implodes at the speed of sound and returns to a liquid state. This implosion sends off a small, but violent shockwave that takes away a little bit of any metal that is around it. This is what we call cavitation. The same principle is constructively applied to Sonic cleaning. Conventional wet sump pumps will live with it until suddenly, the cavitation intensifies to the point that the pump housing just breaks apart.