JP2009203958A5 - - Google Patents

Claims (12)

In the uniaxial eccentric screw pump in which the male screw type rotor is fitted into the inner hole of the female screw type stator, and either or both of the rotor and the stator rotate to discharge fluid from the discharge port,
A repulsive force generation unit having a rotor side magnetic pole part that is provided on the rotor and generates a rotor side magnetic pole, and a stator side magnetic pole part that is provided on an inner wall part that forms an inner hole of the stator and generates a stator side magnetic pole; The uniaxial eccentric screw pump, wherein the rotor side magnetic pole and the stator side magnetic pole have the same polarity. The cross-sectional shape perpendicular to the central axis of the inner hole of the stator is substantially oval,
The uniaxial eccentric screw pump according to claim 1, wherein the stator side magnetic pole portion is provided on each parallel inner wall portion that forms the inner hole and faces each other. Two sets of the repulsive force generating portions are provided at intervals in the central axis direction of the inner hole of the stator,
The first stator side magnetic pole part of the first first repulsive force generation part and the second stator side magnetic pole part of the other second repulsive force generation part are substantially orthogonal to each other,
3. The single-shaft eccentric screw pump according to claim 2, wherein a first rotor-side magnetic pole portion and a second rotor-side magnetic pole portion are provided in the rotor in correspondence with the first and second stator-side magnetic pole portions. .   4. The single-shaft eccentric screw pump according to claim 3, wherein two sets of the first and second repulsive force generating portions are provided at intervals in the central axis direction of the inner hole of the stator.   The uniaxial eccentric screw pump according to any one of claims 1 to 4, wherein the stator side magnetic pole portion is a permanent magnet or a magnetic body. The rotor has a substantially circular cross-sectional shape perpendicular to its central axis, and has a diameter smaller than the interval between the parallel inner wall portions of the inner hole facing each other,
The uniaxial eccentric screw pump according to any one of claims 2 to 5, wherein the rotor-side magnetic pole portion is provided on an outer peripheral wall portion of the rotor.   2. The rotor and the stator, respectively, are rotatably supported, and one of the rotor and the stator is rotationally driven, and the other is rotationally driven by the rotation of one of them. The uniaxial eccentric screw pump in any one of thru | or 6.   The single-shaft eccentric screw pump according to any one of claims 1 to 7, wherein either one or both of the rotor and the stator are rotatably supported by a magnetic levitation bearing.   9. The single-shaft eccentric screw pump according to claim 1, wherein one or both of the rotor and the stator is rotatably supported by a magnetic non-contact type thrust bearing.   8. One or both of the rotor and the stator are rotatably supported by a magnetic non-contact bearing capable of receiving both a radial load and a thrust load. A uniaxial eccentric screw pump according to any one of the above. The stator is rotatably supported by a magnetic levitation bearing having an outer magnetic pole part and an inner magnetic pole part,
The outer magnetic pole portion is provided in a casing that covers the stator,
The inner magnetic pole portion is provided in a range excluding an outer wall portion formed on the outer side of each end portion of the inner hole in the cross section of the long axis direction in the outer peripheral wall portion of the stator. The uniaxial eccentric screw pump according to claim 2. The stator is provided in a pump casing;
One end of each of the rotor and the stator is rotatably supported via pivot portions at predetermined positions on the inner surface of the pump casing,
The single-shaft eccentric screw pump according to any one of claims 1 to 11, wherein one or both of the rotor and the stator are rotationally driven by a drive unit.