Pump magnet housing with integrated sensor element

Abstract

An exemplary magnetically-driven fluid pump includes a magnet housing (“cup”) that enables one or more sensors to be in indirect (“non-wetted”) contact with the pumped fluid while avoiding the static seals normally required with sensors that are mounted to a fluid conduit or chamber and extend into the fluid pathway. Sensors may be used for monitoring the fluid or for feedback control of the pump. By coupling sensors directly to electronic circuits that control the pump, the number of wires located outside the motor housing is minimized, making the assembly more rugged. This is particularly advantageous in hazardous environments or submerged applications. Pumps and hydraulic systems disclosed exhibit fewer leaks under more aggressive pumping conditions and while providing improved pump performance, compared to conventional pumps and systems.

1 . A pump assembly, comprising:
 a pump head including a sealed pump housing;   a movable pumping member situated inside the pump housing;   a driven magnet connected to the pumping member so that induced motion of the driven magnet causes corresponding induced motion of the pumping member;   a magnet housing being a respective portion of the pump housing and containing the driven magnet so that the induced motion of the driven magnet occurs in the magnet housing, the driven magnet and interior of the magnet housing being wetted by fluid being pumped by induced motion of the pumping member;   at least one sensor element sealingly mounted with respect to a wall of the magnet housing such that the sensor is not wetted by the fluid; and   a magnet-driver situated outside the magnet housing and being magnetically coupled to the driven magnet such that a changing magnetic field produced by the magnet-driver induces motion of the driven magnet and hence of the pumping member in the housing.   
     
     
         2 . The pump assembly of  claim 1 , wherein the sensor element is integral to the wall of the magnet housing. 
     
     
         3 . The pump assembly of  claim 1 , wherein the sensor element is sealingly mounted in the wall. 
     
     
         4 . The pump assembly of  claim 1 , wherein the sensor element is sealingly mounted to the wall. 
     
     
         5 . The pump assembly of  claim 1 , wherein the sensor element is sealingly mounted within the wall. 
     
     
         6 . The pump assembly of  claim 1 , wherein the sensor element comprises a transducer. 
     
     
         7 . The pump assembly of  claim 1 , wherein:
 the wall of the magnet housing comprises a wet surface and a dry surface;   the wet surface contacts the fluid in the interior of the magnet housing; and   the sensor does not contact the fluid in the interior of the magnet housing.   
     
     
         8 . The pump assembly of  claim 1 , wherein the sensor is situated within a cavity in a wall of the magnet housing. 
     
     
         9 . The pump assembly of  claim 1 , further comprising an electrical connection to the sensor. 
     
     
         10 . The pump assembly of  claim 1 , further comprising a wireless electrical connection to the integral sensor. 
     
     
         11 . The pump assembly of  claim 1 , wherein:
 the pumping member comprises a driving gear and a driven gear interdigitated with the driving gear; and   the driving gear is coupled to the driven magnet.   
     
     
         12 . The pump assembly of  claim 1 , wherein:
 the magnet housing comprises a body and a distal-end wall;   the sensor is integrated into the distal-end wall; and   the sensor is surrounded by a circuit board, comprising a rigid electrical connection to the sensor.   
     
     
         13 . The pump assembly of  claim 1 , further comprising a printed circuit board electrically connected to the sensor element. 
     
     
         14 . The pump assembly of  claim 1 , wherein the magnet driver comprises a stator. 
     
     
         15 . The pump assembly of  claim 12 , further comprising:
 a motor housing containing the stator; and   stator-driver electronics situated in the motor housing and electrically connected to the stator.   
     
     
         16 . The pump assembly of  claim 1 , wherein the sensor element comprises at least one transducer selected from the group consisting of pressure transducers, temperature transducers, flow-rate transducers, conductivity transducers, rotation-sensing transducers, dissolved gas transducers, pH transducers, turbidity-sensing transducers, ion-specific-sensing transducers, optical-absorption transducers, and combinations thereof. 
     
     
         17 . The pump assembly of  claim 1 , wherein the sensor element is selected from the group consisting of strain-gauges, capacitive transducers, resistive transducers, inductive transducers, piezoelectric transducers, magnetically-coupled transducers, Hall effect transducers, and electrodes. 
     
     
         18 . The pump assembly of  claim 1 , wherein the sensor element is sealingly mounted into a wall of the magnet housing, by a procedure selected from the group consisting of direct welding, laser welding, separate membrane welding, brazing, over-molding, adhesive bonding, statically sealing in place, clamping, mechanically joining, molding, and casting. 
     
     
         19 . The pump assembly of  claim 1 , wherein the pumping member is selected from the group consisting of pump gears, centrifugal members, lobed members, and pistons. 
     
     
         20 . The pump assembly of  claim 1 , further comprising a pressure-compliant member situated inside the pump housing. 
     
     
         21 . The pump assembly of  claim 1 , wherein:
 the sensor element is a pressure transducer; and   the sensor element is located at either a pump-inlet region of the magnet housing, for sensing inlet pressure, or a pump-outlet region of the magnet housing, for sensing outlet pressure.   
     
     
         22 . The pump assembly of  claim 1 , further comprising:
 a sensor electronic circuit located outside the pump housing and electrically connected to the sensor element;   a driver circuit located outside the pump housing and electrically connected to the magnet driver; and   a controller electrically connected to the sensor electronic circuit and to the driver circuit, the controller being configured to control operation of the magnet driver, and hence of the pumping member, based on data provided to the controller by the sensor electronic circuit.   
     
     
         23 . A pump head, comprising:
 a sealed pump housing;   a pumping member situated inside the housing;   a driven magnet situated in the housing and connected to the pumping member so that induced motion of the driven magnet causes corresponding induced motion of the pumping member;   a magnet housing being a respective portion of the pump housing and containing the driven magnet so that the induced motion of the driven magnet occurs in the magnet housing, the driven magnet and interior of the magnet housing being wetted by the fluid being pumped by induced motion of the pumping member; and   at least one sensor element integrally mounted to a wall of the magnet housing such that the sensor element is sensitive to at least one parameter of the fluid being pumped by the pumping member.   
     
     
         24 . The pump head of  claim 23 , wherein:
 the sensor element includes a parameter-sensitive surface that is capable of measuring properties of the fluid being pumped; and   the sensor element is integrally mounted to a wall of the magnet housing such that the parameter-sensitive surface faces the interior of the magnet cup.   
     
     
         25 . The pump head of  claim 23 , wherein the sensor element is integrally mounted in a wall of the magnet housing such that the sensor is adjacent to a wet surface in contact with the fluid in the interior of the magnet cup. 
     
     
         26 . A method for controlling a magnetically-driven hydraulic pump, in which a pumped fluid is separated from pump-driving electronic components by a pump housing including a magnet housing, the method comprising:
 providing a sensor, mounted relative to a wall of the magnet housing, such that the sensor is not wetted by the fluid;   using the sensor, measuring at least one parameter of the fluid to produce a measurement signal;   supplying the measurement signal as a control signal to the electronic components, the control signal having at least one characteristic based on the measurement of the parameter and being a signal to which the electronic components are operationally responsive; and   based on the control signal, inducing the electronic components to produce a corresponding change in driving of the pump.   
     
     
         27 . A fluid pump, comprising:
 pump-element means magnetically coupled to driven magnet means;   pump housing means for containing the pump-element means separate from an external environment and in contact with a fluid to be pumped, the pump housing means comprising housing means for said driven magnet means;   magnet-drive means, located external to said housing means for said driven magnet means, for inducing motion of said driven magnet means, and thus of said pump-element means in said housing means;   parameter sensing means associated with said housing means for measuring at least one property of the fluid without contacting the fluid;   pump control means coupled to said parameter sensing means for receiving data associated with said measured at least one property and for producing a corresponding pump-control signal; and   means for adjusting operation of the pump in response to the corresponding pump-control signal.