Magnetic Drive & Seal-less water pumps
Magnetic Drive & Seal-less water pumps
(OP)
Hello...
Has anyone got any ideas of, or has anyone seen a water pump with a magnetic varible drive coupling.
One without a shaft seal would be nice.
We have considered many ideas but we really need some inspiration.
We need a strategy that is fail safe, with a mechanism that seperates the magnetic drive plates and reduces the speed of the impeller to reduce flow.
Fail safe means maximum flow on start up.
Ideally, the pump control will respond to temperature and or flow and or pressure...
Mechanical only, no electronics allowed, for commercial reasons.
Seperating force of drive is in the region of 300-400N.
Any ideas..?
Adrian
Has anyone got any ideas of, or has anyone seen a water pump with a magnetic varible drive coupling.
One without a shaft seal would be nice.
We have considered many ideas but we really need some inspiration.
We need a strategy that is fail safe, with a mechanism that seperates the magnetic drive plates and reduces the speed of the impeller to reduce flow.
Fail safe means maximum flow on start up.
Ideally, the pump control will respond to temperature and or flow and or pressure...
Mechanical only, no electronics allowed, for commercial reasons.
Seperating force of drive is in the region of 300-400N.
Any ideas..?
Adrian





RE: Magnetic Drive & Seal-less water pumps
It sounds as though an inverter can be your best solution, and many applications we deal with are Inverter driven to control systems. www.cdrpumps.co.uk details some pumps suitable for this drive method.
Inverter drive, or even the Lowara Hydrovar is used frequestly to control processes on many kinds of centrifs, and they are now pretty cheap compared to a few years ago !!
RE: Magnetic Drive & Seal-less water pumps
RE: Magnetic Drive & Seal-less water pumps
What is motor speed, horsepower; pump pressure and flow; static pressure and temperature at the magnetic drive boundry? When you say "mechanical only" for the speed control, do you mean a manual control mechanisn with movement by operator. If not, then would you consider a electro-mechanical device for speed control?
Walt
w_f_strong [at] msn [dot] com
RE: Magnetic Drive & Seal-less water pumps
The application would be on a commercial diesel engine.
We have a basic concept in that the normal mode of operation for the magnets would see them close together giving full drive speed from the engine.
A wax cell or similar would be used to seperate the magnets causing the drive to slip and the pump to run slower, reducing parasitic losses in the engine.
The problems we have have are maintaining fail safe operation...keeping full flow when the engine starts but then increasing slippage quickly when the water is cold or reducing slippage if the water becomes hot. Pumping lots of cold water around a cold engine wastes fuel. Pumping no water around hot engines is not good either.
Also the seperating forces of the magnets are in the region of 300N and the energy losses during slippage are huge.
Not to mention the magnets attracting all of the loose ferrous particles in the coolant.
For information...one of the magnets would be on the drive pulley and the other on the impeller. No drive shaft between means no shaft seal.
It is as we suspected...over ambitious!
Thanks again...
Adrian