can messhing gears be rotated by reverse flow?

Question

messhing gears are positive displacement pump powered by electric motor....can they be rotated by liquid flow?

Answer 1

Neat question. The instinctive answer is no (equal pressures on meshing teeth and outer teeth). But the ref. describes the way hydraulic gear motors work. And when you think further, if you had a way to put pressure on the meshed teeth only, there would still be no flow and so no work done.

Answer 2

Hi!
Meshed gear pumps are positive displacement. If you look at the design, the gears are meshed in the middle of the pump and the fluid is pumped on both gears 180 degrees from where they are meshed. The fluid is trapped between the gear teeth and the pump case. If no pumping force is on the shaft(s), and fluid is under pressure on what whould be the output side, the fluid will attempt to escape by pushing the teeth between the case and gear teeth. Not too efficient, but a motor non the less.

Look here http://www.pumpschool.com/principles/external.htm

Answer 3

Yes, and they will. There are cheap versions of meshed gear pumps that can function as either pumps or hydraulic motors.

The reason is that the flow is on the outside of the meshed gears. Where the fluid pressure acts on the full width of the tooth to rotate the gear in one direction. The fluid pressure acted on the meshed gears can act on only a small portion of the gear tooth (gears are meshed).

Answer 4

It depends on the pump design

I have seen P-D gear pumps that were not energized, turned backwards by reversed flow.

When that happens what you have is a very inefficient generator.

Answer 5

http://images.google.com.au/images?svnum=10&hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=hydraulic+motors+external+gear&spell=1
I agree good question

Answer 6

challenging point. search with yahoo and bing. that will can assist!