Novel magnetic suspension bearingless motor and pump

Abstract

The novel magnetic suspension bearingless motor comprises permanent magnet rotors, a main shaft and a stator assembly, the two permanent magnet rotors are coaxially arranged along the axial direction, the two permanent magnet rotors are respectively and fixedly connected with the main shaft, the number of magnetic poles of the two permanent magnet rotors is the same, and the arrangement directions of the magnetic poles are the same. The two stator assemblies are located on the outer sides of the two permanent magnet rotors respectively, and the two stator assemblies drive the two permanent magnet rotors to suspend and rotate through magnetic force respectively. The two stator assemblies correspond to the permanent magnet rotors respectively, two independent magnetic circuits are formed, the total electromagnetic force borne by the permanent magnet rotors is improved, and therefore under the condition that the sizes of motors are the same, larger power is provided for a main shaft, and the flow and lift of a pump are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of magnetic suspension bearingless motor, especially a novel magnetic suspension bearingless motor and pump. BACKGROUND

[0002] Traditional centrifugal pumps usually use mechanical bearings to support and position the rotor. This design is prone to problems such as bearing wear, lubricant failure, unreliable seals, and inability to meet ultra-clean requirements. In addition, traditional pumps have vibration and noise problems, and high operating costs. To overcome these shortcomings, magnetic suspension technology is widely used in the pump field.

[0003] Magnetic suspension technology suspends the impeller in the pump casing using magnetic fields, achieving a contactless and wear-free operating state. Compared with traditional mechanical bearing centrifugal pumps, magnetic suspension pumps have higher efficiency, longer service life, and lower maintenance costs.

[0004] Despite the significant progress made in magnetic suspension pumps, there are still some challenges in existing technology. In particular, thin-sheet magnetic suspension motors, which drive magnetic suspension pumps, have bottlenecks for large flow delivery, such as low torque and poor stability during rotation.

[0005] The end of the magnetic suspension motor spindle is fixedly connected with the impeller, and the impeller provides a radial external force to the spindle. When the radial external force received by the spindle is small, the magnetic resistance force between the permanent magnet rotor and the stator can suppress the deflection of the spindle. However, when the radial external force received by the spindle is large, the stator needs to provide additional magnetic force to the permanent magnet rotor to suppress the deflection of the spindle. The spindle of the magnetic suspension motor used in the current magnetic suspension pump only has one permanent magnet rotor, resulting in a large deflection amplitude of the spindle. SUMMARY

[0006] The utility model aims at solving above-mentioned problem, provides a kind of novel magnetic suspension bearingless motor and pump, solves above-mentioned technical problem.

[0007] A novel magnetic suspension bearingless motor, comprising: a permanent magnet rotor, a spindle and a stator assembly, two permanent magnet rotors are coaxial and arranged along the axial direction, two permanent magnet rotors are fixedly connected with the spindle respectively, the number of magnetic poles of two permanent magnet rotors is same and the arrangement direction of magnetic poles is same, two stator assemblies are respectively located outside two permanent magnet rotors, two stator assemblies respectively drive two permanent magnet rotors to suspend and rotate by magnetic force.

[0008] Further, the stator assembly includes a plurality of coil groups, and the coil groups of the stator assembly are uniformly arranged around the corresponding permanent magnet rotor.

[0009] Further, the second magnetic yoke is annular, and the main shaft passes through a through hole in the interior of the second magnetic yoke.

[0010] Further, the second magnetic yoke is annular, and the main shaft passes through a through hole in the interior of the second magnetic yoke.

[0011] Further, each pair of coil sets of the two stator assemblies shares a first magnetic yoke, and the first magnetic yoke passes through the second magnetic yoke.

[0012] Further, the first magnetic yoke comprises axial arms and radial arms, the two ends of the axial arms are fixedly connected with the radial arms which protrude inward, the two radial arms of the same first magnetic yoke are located at the outer sides of the two permanent magnet rotors respectively, and the coil sets are sleeved on the outer sides of the axial arms; the second magnetic yoke is in contact with and fixedly connected with the axial arms.

[0013] Further, the coil sets comprise suspension coils and rotating coils, the suspension coils and the rotating coils are sleeved on the outer sides of the first magnetic yokes respectively, the rotating coils are used for driving the permanent magnet rotors to rotate, the suspension coils and the rotating coils jointly drive the permanent magnet rotors to suspend, and the rotating coils of the same coil set are located at the end of the suspension coils which is close to the second magnetic yoke.

[0014] Further, the main shaft is made of a non-magnetic conductive material, and the number of pole pairs of each permanent magnet rotor is 1.

[0015] Further, the utility model further comprises a machine shell, the stator assemblies are located in the interior of the machine shell and are fixedly connected with the machine shell, and the permanent magnet rotors and the main shaft are not in contact with the machine shell.

[0016] A pump using the novel magnetic suspension bearingless motor, further comprising a pump shell and an impeller, the pump shell is fixed with the machine shell, the pump shell is formed with an inlet and an outlet respectively, the permanent magnet rotors and the main shaft are located in the interior of the pump shell, and the impeller is fixedly connected with the permanent magnet rotors and / or the main shaft.

[0017] The utility model has the following advantages:

[0018] 1. Two stator assemblies correspond to one permanent magnet rotor respectively, two independent magnetic circuits are formed, the total electromagnetic force borne by the permanent magnet rotor is improved, thereby, greater power is provided for the main shaft under the condition that the motor size is same, and the flow and lift of the pump are improved;

[0019] 2. The two independent magnetic circuits can change the magnetic force borne by the two permanent magnet rotors respectively, thereby, two forces with different sizes are provided for the two ends of the main shaft when the main shaft receives radial external force close to the impeller, the deviation and deflection amplitude of the main shaft are reduced, and the stability of the main shaft during rotation is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. Obviously, the drawings described below are only an embodiment of the present application, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0021] Figure 1 : cross-sectional structure diagram of the magnetic suspension motor;

[0022] Figure 2 : schematic diagram of magnetic pole change of the rotating magnetic field;

[0023] Figure 3 : schematic diagram of magnetic pole change of the suspension magnetic field;

[0024] Figure 4 : schematic diagram of the three-dimensional structure of the magnetic suspension motor after removing the shell;

[0025] Figure 5 : schematic diagram of the three-dimensional structure of the magnetic suspension motor after removing the shell and the main shaft;

[0026] Figure 6 : schematic diagram of the three-dimensional structure of the magnetic suspension pump;

[0027] Figure 7 : schematic diagram of the cross-sectional structure of the magnetic suspension pump;

[0028] Figure 8 : schematic diagram of the cross-sectional structure at A-A in Figure 7 . DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the drawings and examples:

[0030] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0031] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the description of the utility model, it is understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0033] Embodiment one:

[0034] As Figures 1 to 8 shown, a novel magnetic suspension bearingless motor, comprising: permanent magnet rotor 4, main shaft 5 and stator assembly, two permanent magnet rotors 4 are coaxial and arranged along the axial direction, two permanent magnet rotors 4 are fixedly connected with main shaft 5 respectively, the number of magnetic poles of two permanent magnet rotors 4 is same and the magnetic pole arrangement direction is same, two stator assemblies are respectively located at the outer side of two permanent magnet rotors 4, two stator assemblies respectively drive two permanent magnet rotors 4 to suspend and rotate through magnetic force, that is, each permanent magnet rotor 4 can form a closed magnetic circuit independently with the corresponding stator assembly, and each independent magnetic circuit is used for the suspension and rotation of the corresponding permanent magnet rotor 4 respectively.

[0035] Further, the stator assembly comprises a plurality of coil groups, and the coil groups of the stator assembly are uniformly arranged around the corresponding permanent magnet rotor 4.

[0036] Further, it further comprises a second magnetic yoke 8, and the stator assembly further comprises a first magnetic yoke 1, each coil group is sleeved outside a first magnetic yoke 1, and the second magnetic yoke 8 is located between the coil groups of two stator assemblies. The second magnetic yoke 8 plays a role of magnetic conduction, and the two independent magnetic circuits share a second magnetic yoke 8, and the two independent magnetic circuits all pass through the second magnetic yoke 8.

[0037] Further, the second magnetic yoke 8 is annular, and the main shaft 5 passes through the through hole in the inside of the second magnetic yoke 8.

[0038] Further, each pair of coil groups of two stator assemblies shares a first magnetic yoke 1, and the first magnetic yoke 1 passes through the second magnetic yoke 8.

[0039] Further, the first magnetic yoke 1 comprises axial arms 11 and radial arms 12, the axial arms 11 are fixedly connected with the inwardly protruding radial arms 12 at both ends, the two radial arms 12 of the same first magnetic yoke 1 are respectively located at the outer sides of the two permanent magnet rotors 4, and the coil sets are sleeved outside the axial arms 11; the second magnetic yoke 8 is in contact with and fixedly connected with the axial arms 11. The radial arms 12 protrude inwardly, which can make the distance between the radial arms 12 and the permanent magnet rotors 4 closer and the air gap smaller, thereby reducing the magnetic leakage.

[0040] Each coil set can comprise one or more coils:

[0041] Optionally, one coil set comprises one coil. At this time, one coil provides a rotating magnetic field and a suspension magnetic field for one permanent magnet rotor 4. The structure with only one coil is simpler, but the control system has higher requirements.

[0042] Optionally, the coil set comprises a suspension coil 2 and a rotating coil 3, the suspension coil 2 and the rotating coil 3 are respectively sleeved outside the first magnetic yoke 1, the rotating coil 3 is used to drive the permanent magnet rotor 4 to rotate, and the suspension coil 2 and the rotating coil 3 jointly drive the permanent magnet rotor 4 to suspend. In this way, the number of coils used by each coil set is larger, but the requirement of the control system is lower.

[0043] Further, a radial sensor and a controller are further included, the radial sensor is used to detect the radial positions of the upper and lower ends of the main shaft 5, and the controller is used to change the current of the suspension coil 2 in the coil set. The main shaft 5 is deflected by the magnetic forces with different sizes provided to the two permanent magnet rotors 4 by the suspension coils 2 at the upper and lower ends.

[0044] Further, the main shaft 5 is made of a non-magnetic conductive material, thereby avoiding the formation of an axial magnetic circuit between the two permanent magnet rotors 4 in the main shaft 5.

[0045] Further, a housing 6 is further included, the stator assembly is located inside and fixedly connected with the housing 6, and the permanent magnet rotor 4 and the main shaft 5 are not in contact with the housing 6.

[0046] Further, the number of pole pairs of each permanent magnet rotor 4 is 1.

[0047] This embodiment takes an example of each stator assembly having eight coil sets and each permanent magnet rotor 4 having two radially magnetized poles to explain the suspension and rotation principles of two permanent magnet rotors 4 corresponding to an independent magnetic circuit respectively. It should be noted that the structure of the two permanent magnet rotors 4 corresponding to one magnetic circuit in this embodiment is not only applicable to the above-mentioned eight first magnetic yokes 1 and the permanent magnet rotor 4 with two magnetic poles, but also applicable to the combination of permanent magnet rotors 4 with different numbers of magnetic poles and different numbers of coil sets.

[0048] AsFigure 1 As shown, the coil group of the upper layer generates a magnetic potential, and the magnetic circuit of the upper layer passes through the upper half of the left first magnetic yoke 1, the upper layer of the permanent magnet rotor 4, the upper half of the right first magnetic yoke 1, and the second magnetic yoke 8, respectively; the coil group of the lower layer generates a magnetic potential, and the magnetic circuit of the lower layer passes through the lower half of the left first magnetic yoke 1, the lower layer of the permanent magnet rotor 4, the lower half of the right first magnetic yoke 1, and the second magnetic yoke 8, respectively.

[0049] It should be noted that each independent main magnetic circuit 13 ( Figure 1 includes two components of the rotating magnetic circuit generated by the rotating coil 3 and the suspension magnetic circuit generated by the suspension coil 2.

[0050] Now let the rotating coil 3 group of two adjacent first magnetic yokes 1 pass through the same current, and at a certain moment, generate an N-pole magnetic field, then the rotating coil 3 group of the radially symmetrical two first magnetic yokes 1 (the same stator assembly) should pass through opposite same direction current, so as to generate S-pole magnetic field at the same moment, at this moment, a pair of magnetic field required for rotation is formed, through the phase change of current, the pair of magnetic field realizes rotation, thereby driving the permanent magnet rotor 4 to realize rotation, the position change of the rotating magnetic field and the permanent magnet rotor 4 is as shown in Figure 2 .

[0051] Among them, Figure 2 The upper layer and the lower layer are both from the perspective of looking down, Figure 2 The "upper layer" in the figure refers to the magnetic field of the upper layer stator assembly and the upper layer permanent magnet rotor 4, the "lower layer" refers to the magnetic field of the lower layer stator assembly and the lower layer permanent magnet rotor 4, the angle below refers to the angle of rotation of the permanent magnet rotor 4, the magnetic field inside the circle is the magnetic field of the permanent magnet rotor 4, and the magnetic field outside the circle is the rotating magnetic field of the corresponding radial arm 12.

[0052] For the radial active suspension of the permanent magnet rotor 4, it is necessary to control the generation of 2 pairs of magnetic poles by passing current through the suspension coil 2 of the stator assembly, which is the existing technology in the field of magnetic suspension motor. The number of suspension magnetic poles is equal to the number of rotating magnetic poles ± 1 pair, and for the offset correction of the permanent magnet rotor 4, it is realized by the resultant magnetic field of the suspension magnetic field superimposed on the rotating magnetic field.

[0053] The position change of the suspension magnetic field and the permanent magnet rotor 4 is as shown in Figure 3 . Among them, Figure 3 The upper layer and the lower layer are both from the perspective of looking down, Figure 3 The "upper layer" in the figure refers to the magnetic field of the upper layer stator assembly and the upper layer permanent magnet rotor 4, the "lower layer" refers to the magnetic field of the lower layer stator assembly and the lower layer permanent magnet rotor 4, the angle below refers to the angle of rotation of the permanent magnet rotor 4, the magnetic field inside the circle is the magnetic field of the permanent magnet rotor 4, and the magnetic field outside the circle is the rotating magnetic field of the corresponding stator assembly.

[0054] Of these, apart from the radial 2 degrees of freedom which are active suspension and axial rotation, the remaining degrees of freedom are all passive suspension.

[0055] It should be noted that since the polarities of the magnetic poles along the axes of the two permanent magnet rotors 4 are the same, the polarities of the two radial arms 12 of the same first magnetic yoke 1 are also the same.

[0056] In this embodiment, because the upper and lower layers can form separate closed loops, Figure 1 The thickness and magnetic force of the two permanent magnet rotors 4 can be different. Different magnetic forces will result in different levitation forces on the two permanent magnet rotors 4. To address the potentially different force requirements at both ends of the main shaft 5 in actual situations, the thicknesses of the two permanent magnet rotors 4 can be set differently. Simultaneously, the thickness of the corresponding radial arm 12 should be adjusted accordingly to reduce unnecessary magnetic leakage caused by the inconsistency in thickness between the permanent magnet rotors 4 and the radial arm 12.

[0057] During operation, the rotation of the main shaft 5 drives the load to rotate, and the suspension of the main shaft 5 reduces friction. The two stator assemblies, together with the two permanent magnet rotors 4, increase the output power of the main shaft 5 without changing the volume.

[0058] Example 2:

[0059] like Figures 1 to 8 As shown, a pump using the novel magnetic levitation bearingless motor described in Embodiment 1 further includes a pump casing 7 and an impeller 73. The pump casing 7 is fixed to the housing 6. The pump casing 7 has an inlet 71 and an outlet 72. The permanent magnet rotor 4 and the main shaft 5 are located inside the pump casing 7. The impeller 73 is fixedly connected to the permanent magnet rotor 4 and / or the main shaft 5.

[0060] Furthermore, the pump housing 7 includes an end cover 74, a pump body 75, and a cylinder 76. The pump body 75 is fixed to and detachably connected to the housing 6. The end of the pump body 75 away from the housing 6 is fixed to and detachably connected to the end cover 74. The end of the pump body 75 near the housing 6 is fixedly connected to the cylinder 76. A central channel 60 is formed inside the housing 6. The cylinder 76 is inserted into the central channel 60. The permanent magnet rotor 4 and the main shaft 5 are located inside the cylinder 76.

[0061] During operation, the main shaft 5 and impeller 73 rotate synchronously, drawing fluid in through inlet 71 and pumping it out through outlet 72. Because the main shaft 5 experiences a radial fluid force at the end closest to impeller 73, the distances from the two permanent magnet rotors 4 to the point on the main shaft 5 where the radial fluid force is applied are different. When the radial force on the main shaft 5 is small, the magnetic resistance between the permanent magnet rotor 4 and the stator assembly can suppress the main shaft 5 from deflecting.

[0062] But when the main shaft 5 is subjected to excessive radial external force, the upper and lower ends need to be applied with external force to restrain it, which requires different forces to be applied to the two ends of the permanent magnet rotor 4. Since the lower permanent magnet rotor 4 is farther away from the force point of the main shaft 5, the force arm is longer, so a smaller force can change the deflection of the main shaft 5.

[0063] The utility model is described above by way of example, but the utility model is not limited to the above specific embodiments, and any modification or change based on the utility model belongs to the range required to be protected by the utility model.

Claims

1. A novel magnetic levitation bearingless motor characterized by, The application relates to a permanent magnet rotor (4), a main shaft (5) and a stator assembly, two permanent magnet rotors (4) are coaxially arranged along the axial direction, the two permanent magnet rotors (4) are fixedly connected with the main shaft (5), the two permanent magnet rotors (4) have the same number of magnetic poles and the same magnetic pole arrangement direction, two stator assemblies are respectively located outside the two permanent magnet rotors (4), and the two stator assemblies respectively drive the two permanent magnet rotors (4) to suspend and rotate through magnetic force. The stator assembly comprises a plurality of coil groups, and the coil groups of the stator assembly are uniformly arranged in a circle around the corresponding permanent magnet rotor (4).

2. A novel magnetic levitation bearingless motor as claimed in claim 1, characterized in that: The application further comprises a second magnetic yoke (8), the stator assembly further comprises a first magnetic yoke (1), each coil group is sleeved outside a first magnetic yoke (1), and the second magnetic yoke (8) is located between the coil groups of the two stator assemblies.

3. A novel magnetic levitation bearingless motor as claimed in claim 2, characterized in that: The second magnetic yoke (8) is annular, and the main shaft (5) passes through a through hole in the inside of the second magnetic yoke (8).

4. A novel magnetic levitation bearingless motor according to claim 3, characterized in that: The application further comprises a radial sensor and a controller, the radial sensor is used for detecting the radial position of the main shaft (5), and the controller is used for changing the current in the coil group. Each pair of coil groups of the two stator assemblies shares one first magnetic yoke (1), and the first magnetic yoke (1) passes through the second magnetic yoke (8).

5. A novel magnetic levitation bearingless motor as claimed in claim 3, wherein: The first magnetic yoke (1) comprises an axial arm (11) and a radial arm (12), the two ends of the axial arm (11) are fixedly connected with the inwardly protruding radial arm (12) respectively, the two radial arms (12) of the same first magnetic yoke (1) are respectively located outside the two permanent magnet rotors (4), and the coil group is sleeved outside the axial arm (11); and the second magnetic yoke (8) is in contact with and fixedly connected with the axial arm (11).

6. A novel magnetic levitation bearingless motor as claimed in claim 5, characterized in that: The coil group comprises a suspension coil (2) and a rotating coil (3), the suspension coil (2) and the rotating coil (3) are respectively sleeved outside the first magnetic yoke (1), the rotating coil (3) is used for driving the permanent magnet rotor (4) to rotate, and the suspension coil (2) and the rotating coil (3) jointly drive the permanent magnet rotor (4) to suspend; and the rotating coil (3) of the coil group is located at one end of the suspension coil (2) close to the second magnetic yoke (8).

7. A novel magnetic levitation bearingless motor as claimed in claim 6, characterized in that: The main shaft (5) is made of a non-magnetic conductive material; and the number of magnetic pole pairs of each permanent magnet rotor (4) is 1.

8. A novel magnetic levitation bearingless motor as claimed in claim 1, characterized in that: The application further comprises a machine shell (6), the stator assembly is located inside the machine shell (6) and is fixedly connected with the machine shell (6), and the permanent magnet rotor (4) and the main shaft (5) are not in contact with the machine shell (6).

9. A novel magnetic levitation bearingless motor as claimed in claim 1, wherein: The application further comprises a pump shell (7) and an impeller (73), the pump shell (7) is fixed with the machine shell (6), the pump shell (7) is respectively formed with an inlet (71) and an outlet (72), the permanent magnet rotor (4) and the main shaft (5) are located inside the pump shell (7), and the impeller (73) is fixedly connected with the permanent magnet rotor (4) and / or the main shaft (5).

10. A pump using the novel magnetic levitation bearingless motor as claimed in claim 9 characterized by: ​

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