Pump

Abstract

A pump system 2 has a drive unit 4 and removable pump units 8, 10 . The pump units have a body 22,26 having a pump cavity 24 and a rotary pump element 34 arranged to rotate in the pump cavity about an axis. Vanes 42 drive fluid from inlet 28 to outlet 30 . A magnetic coupling is provided between magnets 40 in the rotary pump element 34 and magnets 16 in drive unit 4 . A magnetic disk 48 provides an opposed axial force to axially balance the force between magnets 40 and magnets 16.

1 . A pump system, comprising:
 a drive unit, comprising a housing, at least one motor and at least one magnetic coupling drive connected to a respective motor to be rotated by the motor; and   at least one removable pump unit,   the or each removable pump unit comprising:   a body having a pump cavity with an inlet and an outlet,   a rotary pump element arranged to rotate in the pump cavity about an axis, and   a magnetic coupling coupled to the rotary pump element magnetically coupling the rotary pump element with the magnetic coupling drive, and   a plurality of drive vanes for pumping fluid from the inlet to the outlet.   
     
     
         2 . A pump system according to  claim 1 , further comprising a magnetic compensation unit arranged on the opposite side of the magnetic coupling to the magnetic coupling drive to compensate for the axial force between the magnetic coupling and the magnetic coupling drive. 
     
     
         3 . A pump system according to  claim 1 , wherein the magnetic compensation unit is a disk of ferroelectric material arranged on the opposite side of the magnetic coupling to the magnetic drive unit. 
     
     
         4 . A pump system according to  claim 1 , wherein the body comprises:
 a base piece arranged to face the drive unit; and   a cover having the inlet and the outlet and channels to link the inlet and the outlet to the pump cavity;   the base piece and the cover cooperating to define the pump cavity.   
     
     
         5 . A pump system according to  claim 4  wherein the magnetic compensation unit is incorporated in the cover. 
     
     
         6 . A pump system according to  claim 2  wherein the drive unit further comprises a movable lid which in a closed position cooperates with the housing to contain the or each removable pump unit and in an open position allows the or each removable pump unit to be removed,
 wherein the magnetic compensation unit is incorporated in the lid. 
 
     
     
         7 . A pump system according to  claim 1 , wherein the rotary pump unit has a plurality of slits circumferentially arranged and the drive vanes are arranged to be axially displaceable in respective slits. 
     
     
         8 . A pump system according to  claim 1 , wherein the magnetic drive unit comprises a plurality of magnets circumferentially arranged on a drive disk, and the magnetic coupling comprises a corresponding plurality of magnets circumferentially arranged around the rotary pump element to match the drive disk. 
     
     
         9 . A pump system according to  claim 8 , wherein the rotary pump element contains a plurality of axial holes, and wherein the magnets of the magnetic coupling are provided in the axial holes. 
     
     
         10 . A pump system according to  claim 8 , wherein the circumferentially arranged magnets of the drive disk and the corresponding plurality of magnets of the rotary pump element are arranged to have alternating polarity. 
     
     
         11 . A pump system according to  claim 1 , wherein the removable pump units include a single unit with one rotary pump element and a dual unit with a pair of rotary pump elements. 
     
     
         12 . A pump system according to  claim 1 , further comprising an electric battery for providing drive power to the motor. 
     
     
         13 . A removable pump unit for a pump system comprising:
 a base piece defining the pump cavity;   a cover having an inlet and the outlet and channels to link the inlet and the outlet to the pump cavity;   one or more rotary pump elements in the form of a disk with a plurality of slits and a plurality of axial holes contained in the pump cavity without a spindle or axle,   a plurality of magnets in the axial holes to act as a magnetic coupling;   a plurality of vanes in the slits; and   means fixing the cover to the base piece.   
     
     
         14 . A removable pump unit for a pump system according to  claim 13  comprising a magnetic compensation unit in the form of a ferromagnetic disk in the cover. 
     
     
         15 . A removable pump unit for a pump system according to  claim 13  wherein the thickness of the base piece and cover does not exceed  2  cm and the maximum lateral dimension of the base piece and the cover does not exceed 5 cm. 
     
     
         16 . A pump system according to  claim 3  wherein the drive unit further comprises a movable lid which in a closed position cooperates with the housing to contain the or each removable pump unit and in an open position allows the or each removable pump unit to be removed,
 wherein the magnetic compensation unit is incorporated in the lid.