Magnetic coupling for motor drive shaft of electrical submersible pump

An electrical submersible pump assembly, comprising:

• a rotary pump having a rotatably driven pump shaft;
• a motor having a motor shaft that is rotated by the motor and extends along an axis of the pump assembly;
• a plurality of motor shaft disks mounted to the motor shaft for rotation therewith and spaced axially apart from each other, each disk having upward and downward facing disk surfaces joined by an outward facing disk cylindrical surface;
• a plurality of motor shaft magnets mounted in each of the disk cylindrical surfaces and in the upward and downward facing disk surfaces;
• a pump shaft rotor mounted to the pump shaft for rotation therewith, the rotor having a plurality of annular bands axially separated from each other by recesses, each of the bands having upward and downward facing band surfaces joined by an inward facing band cylindrical surface, each of the recesses having an inward facing recess cylindrical surface;
• a plurality of rotor magnets mounted in each of the recess cylindrical surfaces and in the upward and downward facing band surfaces;
• each of the disks extending into one of the recesses, juxtaposing the disk cylindrical surface of each of the disks with one of the recess cylindrical surfaces, juxtaposing the disk upward facing surface with one of the downward facing band surfaces and juxtaposing the disk downward facing surface with one of the upward facing band surfaces;
• a plurality of magnets on the cylindrical surfaces of each of the recesses for interacting with the magnets on the disk cylindrical surfaces;
• and
• a plurality of magnets on the upward and downward facing band surfaces for interacting with the magnets on the downward and upward facing disk surfaces.

An electrical submersible pump assembly, comprising:

• a rotary pump having a rotatably driven pump shaft;
• a motor having a motor shaft that is rotated by the motor and extends along an axis of the pump assembly;
• a magnetic coupling between the motor shaft and the pump shaft, comprising:
• a plurality of motor shaft disks mounted to the motor shaft for rotation therewith and spaced axially apart from each other, each disk having parallel first and second end walls joined by a cylindrical wall, the end walls of each of the disks facing and being spaced axially from the end walls of adjacent ones of the disks;
• a plurality of motor shaft magnets mounted in the cylindrical wall and in the first and second end walls of each of the disks;
• a non rotating shell of non magnetic material sealingly mounted to an end of the motor, the shell having an interior in fluid communication with lubricant contained in the motor, the shell having a plurality of disk receptacles axially spaced apart from each other, each of the disk receptacles having parallel first and second end walls joined by a cylindrical wall;
• the first end wall of each of the disk receptacles being closely spaced to the first end wall of one of the disks, the second end wall of each of the disk receptacles being closely spaced to the second end wall of said one of the disks, and the cylindrical wall of each of the disk receptacles being closely spaced to the cylindrical wall of said one of the disks;
• the shell having a plurality of inner cylindrical walls located between and joining each of the disk receptacles, the inner cylindrical walls having smaller inner diameters than inner diameters of the cylindrical walls of the disk receptacles and extending around the motor shaft between each of the disks;
• a pump shaft rotor mounted to the pump shaft for rotation therewith, the rotor having a plurality of annular recesses axially spaced apart from each other, each of the recesses having a cylindrical wall extending around the cylindrical wall of one of the disk receptacles of the shell, and parallel first and second end walls closely spaced to the first and second end walls, respectively, of said one of the disk receptacles;
• a plurality of annular bands on the rotor, each of the annular bands being located between adjacent ones of the recesses, each of the annular bands having a cylindrical wall closely spaced to one of the inner cylindrical walls of the shell;
• and
• a plurality of magnets on the cylindrical wall and on the first and second end walls of each of the bands for interacting with the magnets on the disks to cause the pump shaft to rotate in unison with the motor shaft.