Magnetic suspension motor with rotor free of permanent magnet, dead-zone-free stirrer and blood pump
By designing a magnetic levitation motor without permanent magnets, using air gaps and coils to drive the suspension and rotation of the rotor, the high cost problem caused by relying on permanent magnets in the prior art is solved, and efficient and economical motor operation is achieved.
Patent Information
- Application Number
- CN202421650565.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-07-12
AI Technical Summary
The bearingless permanent magnet synchronous motors in existing biomedical equipment rely on high magnetic permanent magnets, resulting in high manufacturing costs and need to be discarded after one-time use, which increases the cost of use.
A magnetic levitation motor with a rotor without permanent magnets is designed. By setting a permanent magnet column, a first yoke, a second yoke and a third yoke in the stator, the suspension and rotation of the rotor are driven by air gaps and coils, and the use of permanent magnets is avoided.
It realizes the ability to maintain the motor efficient and stable operation without using permanent magnets, reduces the cost of use, and avoids frequent replacement of rotor components after one-time use.
Smart Images
Figure CN222915737U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motors, in particular to a magnetic levitation motor without permanent magnets on the rotor, a stirrer without dead zones and a blood pump. Background Art
[0002] In the field of biomedical engineering, especially in the applications of disposable bioreactor systems and blood pumps in extracorporeal life support systems, efficient and reliable drive technologies are crucial. The current mainstream technologies in the market tend to use bearingless permanent magnet synchronous motors as the power sources for such devices. These motors achieve contactless rotation based on the stable magnetic fields generated by permanent magnets, ensuring high precision and low wear during operation. However, the rotor, which is a core component of these motors, needs to integrate high-magnetic permanent magnets, such as rare earth materials like neodymium iron boron. This leads to a significant increase in manufacturing costs. Moreover, due to the characteristics of disposable bioreactor systems and blood pumps, the rotor components containing permanent magnets must be discarded after each use, further driving up the overall usage cost.
[0003] In view of the particularity of the biomedical industry and the principle of resource conservation, there is an urgent need to develop a new generation of drive motors that can significantly reduce the usage cost while meeting high-performance requirements. The existing challenge lies in both eliminating expensive permanent magnets and maintaining the high-efficiency and stable operation capabilities of the motors. Summary of the Utility Model
[0004] The utility model aims to solve the above problems and provides a magnetic levitation motor without permanent magnets on the rotor, a stirrer and a blood pump. The technical solutions adopted are as follows:
[0005] A magnetic levitation motor without permanent magnets on the rotor includes a motor housing, a stator and a rotor. The stator includes permanent magnet columns, a first magnetic yoke, a second magnetic yoke and a third magnetic yoke. Both ends of the permanent magnet columns are respectively connected to the first magnetic yoke and the third magnetic yoke. The rotor is sleeved outside the first magnetic yoke, and there is an air gap between the rotor and the first magnetic yoke. The number of the second magnetic yokes is multiple, and they are arranged outside the rotor. One end of the second magnetic yoke is connected to the third magnetic yoke, and there is an air gap between the rotor and the second magnetic yoke. Coils for driving the rotor to levitate and rotate are wound around the second magnetic yoke. Tooth parts are formed radially outward on the rotor. A magnetic path that is sequentially connected is formed among the permanent magnet columns, the first magnetic yoke, the rotor, the second magnetic yoke and the third magnetic yoke.
[0006] On the basis of the above solution, the end of the second magnetic yoke close to the rotor is bent radially inward to form a bent part, and the bent part has the same height as the rotor.
[0007] Preferably, the first magnetic yoke is sleeved outside the permanent magnet column.
[0008] Preferably, the end of the permanent magnet column is in surface contact with the first magnetic yoke.
[0009] Preferably, the end of the permanent magnet column is inserted into the third yoke.
[0010] Preferably, the end of the permanent magnet column is attached to the surface of the third yoke.
[0011] Preferably, it further includes a yoke pressing plate which is fixedly arranged inside the motor housing, and the second yoke is clamped on the yoke pressing plate.
[0012] Preferably, a detection ring is arranged on the lateral peripheral surface of the rotor, and the detection ring is made of a metal material.
[0013] A dead zone-free stirrer includes stirring blades and the above-mentioned magnetic suspension motor of the rotor without permanent magnets. The magnetic suspension motor further includes an upper housing which covers the outside of the permanent magnet column, the first yoke, the second yoke and the displacement sensor, and a closed chamber is formed between the upper housing and the motor housing. A groove is formed by inward depression along the axis at the center position of the upper housing outside the first yoke. The rotor is suspended and rotatably arranged in the groove. A boss protrudes outward along the axis outside the groove. The bent part of the second yoke and the displacement sensor are arranged in the boss. The number of the bosses is multiple, and intervals are arranged between the bosses. A gap is formed between the inner side wall of the boss and the outer side wall of the rotor. The gap is communicated with the outside of the motor through the interval. The stirring blades are fixedly connected to the outer housing of the rotor.
[0014] On the basis of the above scheme, the number of the second yokes accommodated in each boss is 2, and the displacement sensor is arranged between the 2 second yokes of each boss.
[0015] A blood pump uses the above-mentioned magnetic suspension motor.
[0016] The beneficial effects of the present utility model are as follows:
[0017] 1. A bearingless motor design scheme based on the reluctance principle is proposed, separating the permanent magnet from the rotor, overcoming the problem of relatively small starting torque commonly existing in reluctance motors, and successfully realizing an efficient and economical bearingless reluctance motor that is suitable for both disposable bioreactor systems and blood pumps in extracorporeal life support systems, avoiding the high usage cost caused by frequent replacement of the rotor of the permanent magnet magnetic suspension motor in a disposable use environment, and providing strong technical support for the sustainable development of biomedical equipment;
[0018] 2. By improving the motor housing structure and adding an upper housing, a communicating channel is arranged between the motor rotor and the boss, enabling the interior of the moving part of the motor to communicate with the surrounding area, effectively eliminating the stirring dead zone in the stirring area, and ensuring full stirring of the fluid. Description of the Drawings
[0019] Figure 1 : Structural schematic diagram of the present utility model;
[0020] Figure 2 : Schematic diagram of the internal magnetic circuit of the present utility model;
[0021] Figure 3 : Schematic diagram of the upper magnetic circuit of the present utility model;
[0022] Figure 4 : Cross-sectional view of the internal structure of Embodiment 2 of the present utility model;
[0023] Figure 5 : Cross-sectional view of the internal structure of Embodiment 3 of the present utility model;
[0024] Figure 6 : Cross-sectional view of the internal structure of Embodiment 4 of the present utility model;
[0025] Figure 7 : Cross-sectional view of the internal structure of Embodiment 5 of the present utility model;
[0026] Figure 8 : Schematic diagram of the structure of Embodiment 6 of the present utility model;
[0027] Figure 9 : Cross-sectional view of the internal structure of Embodiment 6 of the present utility model. Detailed implementation manners
[0028] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments:
[0029] In the present utility model, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0030] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.
[0031] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.
[0032] Embodiment 1
[0033] As Figures 1 to 3As shown in the figure, a magnetic levitation motor with a rotor without permanent magnets includes a motor housing 1, a stator, and a rotor 31. It also includes a displacement sensor 32 for detecting the offset of the rotor 31. The displacement sensors 32 are arranged in pairs and evenly distributed circumferentially. The stator includes permanent magnet columns 21, a first yoke 22, a second yoke 23, and a third yoke 24. The first yoke 22 and the third yoke 24 are disc-shaped. The two ends of the permanent magnet column 21 are respectively connected to the first yoke 22 and the third yoke 24. The permanent magnet column 21, the first yoke 22, and the third yoke 24 are coaxially arranged. The rotor 31 is sleeved outside the first yoke 22, and there is an air gap between the rotor 31 and the first yoke 22. The number of the second yokes 23 is multiple, and they are arranged outside the rotor 31 and evenly distributed circumferentially within the motor housing 1. One end of the second yoke 23 is connected to the third yoke 24. One end of the second yoke 23 close to the rotor 31 is bent radially inward to form an L-shaped bending part to provide guidance for the magnetic circuit. The form of the rotor 31 can be various. For example, teeth are formed radially outward on the rotor 31, and rotor slots are formed between adjacent teeth. There is an air gap between the end of the tooth part of the rotor 31 and the second yoke 23. Preferably, a detection ring is arranged on the lateral circumferential surface of the rotor 31, and the detection ring is made of a metal material to facilitate the detection by the displacement sensor 32. Coils 26 for driving the suspension and rotation of the rotor 31 are wound around the second yoke 23. The coils 26 include suspension windings and driving windings, or the coils 26 are suspension-driving integrated windings. By energizing the suspension coils, the active radial suspension control of the rotor 31 is realized. Furthermore, by controlling the magnitude of the coil current, the air gap between the rotor 31 and the first yoke 22 or the second yoke 23 is adjusted. Specifically, when the air gap between the rotor 31 and the left second yoke 23 is smaller than the right air gap, the current of the right coil is adjusted to generate more magnetic induction lines. Due to the action of magnetic resistance, a rightward pulling force is generated on the rotor 31 to reset the offset rotor 31, and the air gaps on both the left and right sides are adjusted to the same distance.
[0034] By reasonably designing the position of the permanent magnet column 21, the magnetic force in the magnetic circuit is increased, and thus the motor torque is increased. When the motor is powered off, the permanent magnet column 21 provides an axial suspension force for the rotor 31 to maintain the suspended state of the rotor 31. After the motor is powered on, the number of magnetic induction lines in the permanent magnet 21 increases, and together with the passive axial suspension in the powered-off state, it drives the rotor 31 to maintain the suspended state.
[0035] The magnetic circuit direction is as Figure 2 and Figure 3 shown. A sequentially connected magnetic circuit is formed among the permanent magnet column 21, the first yoke 22, the rotor 31, the second yoke 23, and the third yoke 24. The dotted lines in the figure represent the magnetic circuit, and the arrows represent the magnetic circuit direction. Taking the number of the second yokes 23 as 8 and the number of the tooth parts of the rotor 31 as 6 as an example, when the motor is powered on, the coils 26 wound around the second yokes 23A, B, C, and D are first energized. The coils on the second yokes A and B generate Figure 3In the upper-middle part of the magnetic circuit, the coils on the second yokes C and D generate Figure 3 In the lower-middle part of the magnetic circuit, the directions of the outer magnetic circuits are all counterclockwise, and the direction of the magnetic circuit formed on the rotor 31 is clockwise. According to the principle of minimum magnetic resistance, a tangential force that causes the rotor 31 to rotate clockwise will be generated at the tooth parts of the rotor 31 close to the second yokes B and D, driving the rotor 31 to rotate. After the rotor 31 starts to rotate, the coils on each second yoke generate continuously through on-off cooperation Figure 3 The synchronous clockwise rotating magnetic field in it provides a continuous rotational driving force for the rotor 31, so that the rotor 31 realizes continuous rotation.
[0036] It further includes a yoke pressing plate 25, the yoke pressing plate 25 is fixedly arranged in the motor housing 1, and the second yoke 23 is clamped on the yoke pressing plate 25 for positioning and fixing the second yoke 23.
[0037] Embodiment 2
[0038] As Figure 4 shown, the improvement of this embodiment compared with Embodiment 1 is that the first yoke 22 is sleeved outside the permanent magnet column 21, the end of the permanent magnet column 21 is inserted into the third yoke 24, and the two ends of the permanent magnet column 21 adopt an inserted assembly method, which is convenient for installation.
[0039] Embodiment 3
[0040] As Figure 5 shown, the improvement of this embodiment compared with Embodiment 1 is that the first yoke 22 is sleeved outside the permanent magnet column 21, the end of the permanent magnet column 21 is attached to the surface of the third yoke 24, so that the third yoke 24 bends vertically along the permanent magnet column 21 at the lower end of the permanent magnet column 21 to reduce magnetic flux leakage, and the upper end of the permanent magnet column 21 adopts an inserted assembly method, which is convenient for installation.
[0041] Embodiment 4
[0042] As Figure 6 shown, the improvement of this embodiment compared with Embodiment 1 is that the two ends of the permanent magnet column 21 are respectively attached to the first yoke 22 and the third yoke 24, so that the magnetic induction lines bend horizontally along the first yoke 22 at the upper end of the permanent magnet column 21 and bend vertically along the permanent magnet column 21 by the third yoke 24 at the lower end of the permanent magnet column 21, minimizing magnetic flux leakage to the greatest extent.
[0043] Embodiment 5
[0044] As Figure 7As shown, the improvement of this embodiment compared with Embodiment 1 lies in that the upper end of the permanent magnet column 21 is attached to the surface of the first yoke 22, and the end is inserted into the third yoke 24, so that the magnetic induction lines bend horizontally along the first yoke 22 after passing through the upper end of the permanent magnet column 21, reducing the leakage of magnetic flux. The lower end of the permanent magnet column 21 adopts an inserted assembly method, which is convenient for installation.
[0045] Embodiment 6
[0046] As Figure 8 and Figure 9 As shown, a stirrer without dead zone includes a stirring blade 5 and the magnetic levitation motor described in any one of Embodiments 1 to 5. The magnetic levitation motor further includes an upper housing 41. The upper housing 41 covers the outside of the permanent magnet column 21, the first yoke 22, the second yoke 23 and the displacement sensor 32, and a closed chamber is formed between the upper housing 41 and the motor housing 1. A groove is formed by inward depression along the axis at the center position of the upper housing 41 outside the first yoke 22. The rotor 31 is suspended and rotatably arranged in the groove, and the rotor 31 does not contact the bottom of the groove. A boss 42 protrudes outward along the axis outside the groove. The upper edge of the motor housing 1 is lower than the upper edge of the boss 42. The bent portion of the second yoke 23 and the displacement sensor 32 are arranged in the boss 42. The number of the bosses 42 is multiple, and an interval 44 is arranged between the bosses 42. A gap 43 is formed between the inner side wall of the boss 42 and the outer side wall of the rotor 31. The gap 43 is communicated with the outside of the motor through the interval 44. Through the above structure, it is ensured that the areas on the upper side of the motor upper housing 41 are interconnected with each other and can be communicated with the outside of the motor, completely avoiding the existence of stirring dead zones. The stirring blade 5 is fixedly connected to the outer shell of the rotor 31 by welding, bonding or integral molding, etc., and is arranged towards the direction of the liquid to be stirred. The rotor 31 is driven by the motor to be suspended and rotate, and then drives the stirring blade 5 to rotate continuously to play a stirring role.
[0047] Preferably, the number of the second yokes 23 accommodated in each boss 42 is 2, and the displacement sensor 32 is arranged between the 2 second yokes 23 of each boss 42, so as to optimize the structure of the boss 42 and the liquid flow path.
[0048] Embodiment 7
[0049] A blood pump uses the magnetic levitation motor described in any one of Embodiments 1 to 5, so as to separate the disposable rotor assembly in the blood pump from the permanent magnet, thereby greatly reducing the use cost caused by discarding the disposable rotor assembly after use.
[0050] The present invention has been described by way of example above, but the present invention is not limited to the above specific embodiments. Any modification or variation based on the present invention falls within the scope of protection required by the present invention.
Claims
1. A magnetic levitation motor with a rotor without permanent magnets, characterized in that: The invention comprises a motor housing (1), a stator and a rotor (31), wherein the stator comprises a permanent magnetic column (21), a first magnetic yoke (22), a second magnetic yoke (23) and a third magnetic yoke (24), wherein two ends of the permanent magnetic column (21) are respectively connected to the first magnetic yoke (22) and the third magnetic yoke (24), the rotor (31) is sleeved on the outside of the first magnetic yoke (22), and an air gap exists between the rotor (31) and the first magnetic yoke (22), the number of the second magnetic yokes (23) is multiple and they are arranged on the outside of the rotor (31), one end of the second magnetic yoke (23) is connected to the third magnetic yoke (24), and an air gap exists between the rotor (31) and the second magnetic yoke (23), and a coil (26) for driving the rotor (31) to suspend and rotate is wound around the second magnetic yoke (23), and a magnetic circuit connected in sequence is formed between the permanent magnetic column (21), the first magnetic yoke (22), the rotor (31), the second magnetic yoke (23) and the third magnetic yoke (24).
2. The magnetic levitation motor with no permanent magnet in the rotor according to claim 1, characterized in that: One end of the second magnetic yoke (23) close to the rotor (31) is bent radially inward to form a bent portion.
3. The magnetic levitation motor with a rotor without permanent magnets according to claim 1, characterized in that: The first magnetic yoke (22) is sleeved on the outside of the permanent magnetic column (21).
4. The magnetic levitation motor with a rotor without permanent magnets according to claim 1, characterized in that: The end of the permanent magnetic column (21) is in contact with the surface of the first magnetic yoke (22).
5. The magnetic levitation motor with no permanent magnet in the rotor according to claim 1, characterized in that: The end of the permanent magnetic column (21) is inserted into the third magnetic yoke (24).
6. The magnetic levitation motor with no permanent magnet in the rotor according to claim 1, characterized in that: The end of the permanent magnetic column (21) is in contact with the surface of the third magnetic yoke (24).
7. The magnetic levitation motor with no permanent magnets in the rotor according to claim 1, characterized in that: It also comprises a yoke pressing plate (25), the yoke pressing plate (25) being fixedly arranged in the motor housing (1), the second yoke (23) being clamped on the yoke pressing plate (25), and the number of the second yokes (23) being multiple and uniformly distributed in the circumferential direction in the motor housing (1).
8. The magnetic levitation motor according to claim 1, characterized in that: A detection ring is arranged on the lateral circumferential surface of the rotor (31), and the detection ring is made of a metal material.
9. A dead zone-free agitator, characterized in that: A magnetic levitation motor comprising a stirring blade (5) and a rotor without permanent magnets as claimed in any one of claims 1 to 8, wherein the magnetic levitation motor further comprises an upper shell (41), wherein the upper shell (41) is arranged on the outside of the permanent magnet column (21), the first magnetic yoke (22), the second magnetic yoke (23) and the displacement sensor (32), and a closed chamber is formed between the upper shell (41) and the motor housing (1), and the center of the upper shell (41) is axially inwardly concave at the outside of the first magnetic yoke (22) to form a groove, and the rotor (31) is suspended and rotatable The rotor (31) is movably arranged in the groove, and the outer side of the groove protrudes outward along the axis to form a boss (42). The bent portion of the second magnetic yoke (23) and the displacement sensor (32) are arranged in the boss (42). The number of the bosses (42) is multiple, and a gap (44) is arranged between the bosses (42). A gap (43) is formed between the inner wall of the boss (42) and the outer wall of the rotor (31). The gap (43) is connected to the outside of the motor through the gap (44). The stirring blade (5) is fixedly connected to the outer shell of the rotor (31).
10. A dead zone-free agitator according to claim 9, characterized in that: The number of second magnetic yokes (23) accommodated in each boss (42) is two, and the displacement sensor (32) is arranged between the two second magnetic yokes (23) of each boss (42).
11. A blood pump, characterized in that: A magnetic levitation motor having a rotor without permanent magnets as claimed in any one of claims 1 to 8.