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AssigneeGrundfos Holding A/S
InventorsFlemming Buus Bendixen, Alan Ivo Sogaard Sorensen
Estimating the term…
The present invention relates to a pump unit (300), with at least one impeller, comprising a coupling, wherein the coupling is mechanically connected to the at least one impeller via an inner rotor and where an outer rotor is connected to an electrical machine arranged to produce a rotational torque, said pump being arranged to circulate a hot fluid by the impeller. The coupling includes an outer rotor including a plurality of permanent magnets (101,201) arranged to form a plurality of magnetic poles (105, 205), and an inner rotor (110, 210), whereby the outer rotor and the inner rotor are located coaxially to one another around an axis (130, 230) and spaced apart from one another by an air gap (150,250). A rotor can (330) is arranged in the air gap (250, 150) between the inner rotor and the outer rotor, so as to make a dividing section between the inner and outer rotor. Each of the plurality of magnetic poles comprises at least a section with a radial magnetic direction in respect of the axis (130, 230) and at least a section with a magnetic direction angled between a radial direction and a tangential direction in respect of the axis (130, 230), wherein the combined length of the sides of the plurality of permanent magnets cover less than 75% of the circumference of the cylindrical structure. The outer rotor has a cylindrical structure (120, 220) surrounding the plurality of magnetic poles (105, 205), and the cylindrical structure is made of a magnetic susceptible material for conducting a magnetic flux between the plurality of magnetic poles (105, 205) The inner rotor (110, 210) is made of a magnetic susceptible material and free from permanent magnetic material, wherein the inner rotor is formed with multiple radial projections (111, 211) acting as salient inner rotor poles distributed around the axis (130, 230) of the inner rotor. The invention also relates to a coupling with the above mentioned coupling features.
A pump unit (300) with at least one impeller (340), comprising a magnetic coupling (100, 200), wherein the coupling is mechanically connected to the at least one impeller via an inner rotor and where an outer rotor is connected to an electrical machine arranged to produce a rotational torque, said pump being arranged to circulate a fluid by the impeller, the magnetic coupling comprising
The pump unit according to 1, wherein the outer rotor comprises between two and eight magnetic poles, preferably four or six magnetic poles.
The pump unit according to 1 wherein the number of magnetic poles of the outer rotor is different from the number of salient inner rotor poles.
A magnetic coupling (100, 200) comprising
Dependencies are inferred from the claim text.