Magnetic drive vane pump

Abstract

A magnet drive rotary vane pump has a casing with a pump cavity. A rotor carrying a plurality of vanes is disposed within the pump cavity to be rotatable about an eccentric axis with respect to the pump cavity for drawing the fluid into the pump cavity and expelling it out of the pump cavity. The rotor is configured to have a rotor magnet which is magnetically coupled to a stator magnet mounted on the casing outwardly of the pump cavity for driving the rotor. The rotor magnet is configured to have its major portion disposed in an overlapping relation with the stator magnet. Thus, the rotor magnet can be mechanically isolated from the stator magnet disposed outside of the casing to establish a sealless coupling therebetween for realizing leakage free pump.

1 . A magnet drive vane pump comprising:
 a casing with a pump cavity, an inlet for introducing a fluid into said pump cavity, and an outlet for discharging the fluid out of said pump cavity;   a rotor disposed within said pump cavity to be rotatable about an eccentric axis eccentric to an axis of said pump cavity, said rotor carrying a plurality of vanes which are configured to move radially so as to be kept in sealed contact with an interior wall of said pump cavity as said rotor rotates, said rotor is configured to have a rotor magnet;   a stator magnet mounted to said casing outwardly of said pump cavity and magnetically coupled to said rotor magnet for driving said rotor to rotate;   
       wherein 
       said rotor magnet is configured to have its major portion disposed in an overlapping relation with said stator magnet with respect to a radial direction about said eccentric axis. 
     
     
         2 . The magnet drive vane pump as set forth in  claim 1 , wherein said rotor magnet is disposed radially outwardly of said stator magnet. 
     
     
         3 . The magnet drive vane pump as set forth in  claim 1 , wherein said stator magnet is configured to have its axial center offset from an axial center of said rotor magnet so as to be disposed further away from said rotor than said rotor magnet with respect to said eccentric axis. 
     
     
         4 . The magnet drive vane pump as set forth in  claim 1 , wherein said casing is provided with a shaft defining said eccentric axis, said rotor magnet is fitted around said shaft with a vibration absorbing member interposed therebetween. 
     
     
         5 . The magnetic drive vane pump as set forth in  claim 1 , wherein said vanes are slidably fitted respectively in radial slits formed in said rotor, each of said vanes is formed on its opposite sides with ribs which engage respectively into guide grooves formed in opposite faces of said rotor defining said radial slit therebetween.