A reverse osmosis water purification system that can purify water from a water source, comprising:
- a filter having an inlet and an outlet, said filter further having an osmotic membrane that filters water at a flow rate and operates at a water pressure that does not exceed a maximum pressure;
- a pump operatively connected to the water source and said filter inlet to pump water from the water source to said filter, said pump including;
- a housing having an inlet and an outlet;
- a diaphragm mounted within said housing;
- a piston having a piston head attached to said diaphragm;
- a wobble plate operatively connected to said piston, said wobble plate having a cam surface with a predetermined cam angle;
- a bearing operatively connected to said housing such that said bearing can rotate relative to said housing surface, said bearing having a first surface that operatively engages said cam surface;
- a valve plate mounted inside said housing, said valve plate having a first and second valve portion constructed such that said valve portions, said piston and said diaphragm form a chamber, said first valve portion further has an inlet opening to allow fluid communication between said housing inlet and said chamber, said second valve portion has an outlet opening to allow fluid communication between said chamber and said housing outlet, said first valve portion and said housing defining a valve chamber that is in fluid communication with said housing inlet;
- a motor output shaft attached to said wobble plate to rotate said wobble plate such that said piston is moved relative to said valve plate to expand and contract said chamber in accordance with said cam engagement with said bearing;
- a first valve operatively connected to said first valve portion adapted to allow one way fluid communication from said housing inlet to said chamber through said inlet opening when the fluid pressure in said housing inlet is greater than the fluid pressure in said chamber, said first valve having a first valve opening that can provide fluid communication between said chamber and said valve chamber;
- a second valve operatively connected to said second valve portion adapted to allow one way fluid communication from said chamber to said housing outlet through said outlet opening when the fluid pressure in said chamber is greater than the fluid pressure in said housing outlet;
- and
- a by-pass valve being located within said valve chamber and adapted to control the flow of fluid through said first valve opening such that said pump outlet water pressure does not exceed the maximum pressure of said filter;
- a motor operatively connected to said pump, said motor being adapted to drive said pump so that said pump provides a water flow rate that is approximately equal to the flow rate of said filter;
- a storage tank connected to said filter outlet;
- and,
- logic means operatively connected to said storage tank and said motor for starting said motor when the water within said storage tank reaches a first level and stopping said motor when the water within said storage tank reaches a second level that is greater than said first level, wherein said by-pass valve opens to allow said motor and said pump to run continuously while the water within said storage tank rises from said first level to said second level.