Novel reluctance type magnetic suspension bearingless motor

Abstract

The invention belongs to the technical field of magnetic suspension motors, and discloses a novel reluctance type magnetic suspension bearingless motor, which is characterized in that a stator comprises a first magnet yoke group and an annular second magnet yoke, the first magnet yoke group is formed by a plurality of first magnet yokes which are longitudinally arranged and are circumferentially arranged by taking a rotor as a center, and the annular second magnet yoke is fixedly arranged in the middle of the first magnet yoke group; the second magnet yoke is fixedly connected with all the first magnet yokes; a first driving coil group for driving the rotor to suspend and rotate is wound on an axial arm of the first magnet yoke; the rotor comprises a connecting shaft, and an upper rotor and a lower rotor fixed at two ends of the connecting shaft; upper rotor teeth are arranged on the upper rotor in the circumferential direction, lower rotor teeth are arranged on the lower rotor in the circumferential direction, and the upper rotor and the lower rotor are made of soft magnetic materials. According to the motor, through cooperation of the stator and the reluctance type rotor, a permanent magnet does not need to be used, the magnetic collection effect of the motor is improved, the utilization rate of a magnetic field is improved, and then the working efficiency and stability of the rotor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation motors, and in particular, to a novel reluctance type magnetic levitation bearingless motor. Background Art

[0002] Magnetic levitation motors are divided into bearing magnetic levitation motors and bearingless magnetic levitation motors. The levitation force of the bearing magnetic levitation motor is provided by a separate electromagnetic bearing. The bearingless magnetic levitation motor uses the stator winding and the permanent magnet rotor to achieve active levitation control, and no additional magnetic levitation bearing is required. Therefore, its rotor size is shorter, the output power is large, and since there is no mechanical contact between the rotor and the stator, the noise and wear during operation are small, the pollution is also small, and the operation efficiency and precision are higher. Therefore, it is widely used in various fields, such as semiconductor, health care, smart home, and industrial automation.

[0003] Currently, in order to achieve the radial levitation control of the rotor of the magnetic levitation bearingless motor, in addition to the rotating winding, another set of levitation force windings is added to the stator winding of the ordinary motor. The magnetic fields of the two sets of windings interact through the air gap to generate a radial force. Reasonable control of this force can achieve the levitation of the rotor, and the rotating torque of the motor is generated by the original torque winding, thus forming a bearingless permanent magnet motor. Its stator includes a plurality of longitudinally arranged magnetic yokes arranged around the rotor, so that the magnetic force lines respectively pass through the closed magnetic circuits formed by the longitudinally arranged multiple groups of symmetrically arranged magnetic yokes and the permanent magnets on the corresponding rotors to form a rotating torque and a levitation torque. Currently, such motors can also be divided into reluctance motors, permanent magnet motors, and composite motors according to the type of rotor.

[0004] However, in practical applications, due to its traditional structural design, the above-mentioned existing magnetic levitation motors generally have problems such as a large amount of magnetic leakage, poor magnetic collection effect, and low utilization rate of the space magnetic field.

[0005] Therefore, the prior art needs to be further improved. Summary of the Invention

[0006] In view of the above problems, the present invention provides a novel reluctance type magnetic levitation bearingless motor. The structure of the magnetic levitation motor is simple, the magnetic collection effect is good, the magnetic field utilization rate of the motor can be greatly improved, and the operation stability and reliability of the rotor can be improved.

[0007] To solve the above problems, the present application provides the following technical solutions: A novel reluctance-type magnetic levitation bearingless motor, comprising a rotor and a stator, wherein the stator includes: a first yoke group composed of a plurality of longitudinally arranged first yokes arranged in a circumferential pattern centered on the rotor, and an annular second yoke fixedly arranged in the middle of the first yoke group, and the second yoke is fixedly connected to all the first yokes; the first yoke includes a longitudinally arranged axial arm and a radial arm extending radially from at least one end of the axial arm towards the rotor, and a first drive coil group for driving the rotor to levitate and rotate is wound around the axial arm of the first yoke; the center of the annular second yoke is set to coincide with the rotor center axis of the rotor; The rotor includes a connecting shaft and an upper rotor and a lower rotor fixed at both ends of the connecting shaft; the upper rotor extends along the radial direction of the radial arm at the top of the stator to form a plurality of circumferentially uniformly distributed upper rotor teeth, and the lower rotor extends along the radial direction of the radial arm at the bottom of the stator to form a plurality of circumferentially uniformly distributed lower rotor teeth, and the upper rotor and the lower rotor are made of soft magnetic materials.

[0008] In an optional embodiment, the connecting shaft of the novel reluctance-type magnetic levitation bearingless motor is made of soft magnetic material.

[0009] On this basis, further, a permanent magnet axially magnetized is fixedly arranged in the connecting shaft.

[0010] Optionally, the permanent magnet is embedded as a section of the connecting shaft in the upper part, middle part or lower part of the connecting shaft; or, the permanent magnet is fixed in the hollow cavity of the connecting shaft; or, the permanent magnet is in a plurality of sheet-like structures, and a plurality of permanent magnets are symmetrically fixedly connected to the inner wall or outer wall of the connecting shaft.

[0011] In another optional embodiment, in the novel reluctance-type magnetic levitation bearingless motor, the connecting shaft is made of a non-magnetic conductive material.

[0012] Optionally, in the novel reluctance-type magnetic levitation bearingless motor, the upper rotor teeth of the upper rotor and the lower rotor teeth of the lower rotor are symmetrically arranged up and down and their projections overlap.

[0013] Or, the upper rotor teeth of the upper rotor and the lower rotor teeth of the lower rotor are symmetrically arranged up and down and are offset.

[0014] Optionally, the upper end of the connecting shaft is fixedly connected to the lower end face of the upper rotor, and the lower end of the connecting shaft is fixedly connected to the upper end face of the lower rotor; the connecting shaft is a hollow tubular structure, and a through hole is arranged in the middle; the main bodies of the upper rotor and the lower rotor are circular, and the centers of the upper rotor and the lower rotor are provided with center holes that are aligned with the through hole of the connecting shaft in a penetrating manner; Or, the connecting shaft is a hollow tubular structure, a through hole is arranged in the middle, and first plug-in parts are respectively arranged at the upper and lower ends of the connecting shaft, and second plug-in parts for plug-in cooperation with the first plug-in parts are arranged at the central positions of the upper rotor and the lower rotor; the first plug-in part and the second plug-in part are also adhesively cooperated.

[0015] Optionally, in the novel reluctance - type magnetic - suspension bearingless motor, the second magnetic yoke is vertically connected to the axial arm of the first magnetic yoke; the center of the annular second magnetic yoke is set to coincide with the rotor center axis of the rotor.

[0016] Further optionally, the second magnetic yoke is vertically connected to the middle position of the first magnetic yoke.

[0017] Optionally, radial arms extend from the upper and lower ends of the axial arm of the first magnetic yoke respectively.

[0018] On the above basis, in an optional implementation manner, each first driving coil group is a coil that simultaneously provides a rotating magnetic field and a suspension magnetic field for the rotor, and the first driving coil group is arranged above and / or below the second magnetic yoke.

[0019] On the above basis, in another optional implementation manner, each first driving coil group includes a suspension coil for the rotor suspension magnetic field and a rotating coil for providing a rotating magnetic field for the rotor.

[0020] Further, each group of first driving coil groups is arranged above and / or below the second magnetic yoke, or the suspension coils and rotating coils of each group of driving coils are separately arranged at one position above or below the second magnetic yoke.

[0021] On the above basis, in the novel reluctance - type magnetic - suspension bearingless motor, a second driving coil group for assisting in driving the rotor suspension and rotation is wound on the part of the second magnetic yoke between two adjacent first magnetic yokes.

[0022] Further preferably, each group of second driving coil groups includes a suspension coil for the rotor suspension magnetic field and a rotating coil for providing a rotating magnetic field for the rotor.

[0023] The present invention has the following beneficial effects: 1. The reluctance rotor structure adopted by the novel reluctance - type magnetic - suspension bearingless motor is simple and convenient to use. It does not require the use of permanent magnet materials, greatly reducing the rotor manufacturing cost. There will be no demagnetization problem, with high reliability, long working life, less eddy current, less heat generation, and less motor cooling cost.

[0024] 2. The magnetic - suspension motor provided by the present invention uses a specific stator to cooperate with the above - mentioned reluctance - type rotor. The stator magnetically connects the independent first magnetic yokes through the annular second magnetic yoke, enabling the leakage magnetic fluxes of the first magnetic yokes to be fully utilized through the connected annular magnetic yoke, thereby improving the magnetic - collecting effect of the motor, increasing the utilization rate of the magnetic field, and further improving the working efficiency of the rotor.

[0025] 3. The stator of the motor of the present invention is symmetrically distributed up and down with the second magnetic yoke as the center of symmetry. Therefore, during operation, there is a closed-loop main magnetic path that is symmetrically distributed up and down in the stator. These two main magnetic paths are respectively controlled by two sets of driving coil groups distributed up and down, so as to achieve independent control of the upper and lower parts of the rotor. In this way, not only can the up-and-down axial position offset and radial offset of the rotor be adjusted, but it is more conducive to accurately adjusting the tilt angle of the rotor, realizing the transformation of the tilt angle and suspension control of the rotor from passive control to active control, thereby greatly improving the running stability of the rotor. Due to the high stability of the rotor driven by this stator, the torque of the rotor can be significantly increased. The motor can increase the torque of the rotor by at least more than 10%.

[0026] 4. Through the cooperation of the first driving coil group and the second driving coil group, the stator of the magnetic levitation motor can achieve multi-dimensional control methods, making the control of the rotor more flexible and variable, and effectively improving the control accuracy and stability. Brief Description of the Drawings

[0027] Figure 1 It is a three-dimensional structure schematic diagram of the magnetic levitation motor of Embodiment 1, and the closed-loop route with arrows represents the main magnetic path; Figure 2 It is a longitudinal sectional structure schematic diagram of the magnetic levitation motor of Embodiment 1; the closed-loop route with arrows in the figure represents the main magnetic path; Figure 3 It is a three-dimensional structure schematic diagram of the rotor in the motor of Embodiment 1; Figure 4 It is a three-dimensional structure schematic diagram of the stator in the motor of Embodiment 1; Figure 5 It is a schematic diagram of the rotation principle of the magnetic levitation reluctance motor of the motor of Embodiment 1; Figure 6 A, B, C, and D in are schematic diagrams of four different implementation methods of the stator of the magnetic levitation motor of Embodiment 2; the closed-loop route with arrows in the figure represents the main magnetic path; Figure 7 It is a structure schematic diagram of the stator of the motor of Embodiment 3; Figure 8 It is a three-dimensional structure schematic diagram of the motor of Embodiment 3; the arrow represents the magnetic path; Figure 9 It is a sectional structure schematic diagram of the reluctance rotor of Embodiment 1; A is a reluctance rotor in one implementation method; B is a reluctance rotor in another implementation method.

[0028] The description of the drawing reference numerals is as follows: Rotor 1, upper rotor 11, connecting shaft 12, lower rotor 13, upper rotor teeth 111, lower rotor teeth 131, connecting magnet 15, first magnetic block 11a, second magnetic block 13a, Stator 2, first yoke 21, axial arm 21a, radial arm 21b, second yoke 23, drive coil group 22. Detailed implementation

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present invention. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "vertical", "horizontal", "left", "right", "up", "down", "inside", "outside", "bottom", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0030] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in this specification in the description of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Embodiment 1 As Figures 1 - 3 shown, this embodiment provides a magnetic levitation motor, which includes a rotor 1 and a stator 2. The stator includes: a first yoke group composed of a plurality of longitudinally arranged first yokes 21 arranged in a circumferential manner with the rotor 1 as the center, and a horizontally arranged annular second yoke 23 fixedly arranged on the first yoke group. The second yoke is fixedly connected to all the first yokes.

[0032] As Figure 1 and 3As shown, the rotor adopted in this embodiment is a reluctance-type rotor, which is composed of a non-magnetic connecting shaft 12 and upper and lower rotors 11 and 13 fixed at both ends of the connecting shaft. The upper and lower rotors are made of soft magnetic materials, and corresponding rotor teeth are provided on the upper and lower rotors.

[0033] The connecting shaft is made of non-magnetic materials, such as plastics, aluminum alloys, copper alloys, nickel alloys, stainless steels, etc. In this embodiment, the connecting shaft is a hollow or solid cylinder. This is because the suspension and rotation main magnetic circuits of the rotor do not need to be closed through this connecting part.

[0034] The upper rotor extends along the radial arm direction at the top of the radial stator to form a plurality of circumferentially uniformly distributed upper rotor teeth 111, and the lower rotor extends along the radial arm direction at the bottom of the radial stator to form a plurality of circumferentially uniformly distributed lower rotor teeth 131. The number and specifications of the upper rotor teeth 111 and the lower rotor teeth are the same. The upper and lower rotors are made of soft magnetic materials, such as pure iron low-carbon steel, soft ferrite, and iron-aluminum alloy.

[0035] In this embodiment, the upper rotor teeth 111 of the upper rotor and the lower rotor teeth 131 of the lower rotor are symmetrically arranged up and down and overlap in projection.

[0036] In other embodiments, the upper rotor teeth 111 of the upper rotor and the lower rotor teeth 111 of the lower rotor are arranged in a staggered manner up and down. Preferably, the staggering angle between the upper rotor teeth 111 of the upper rotor and the corresponding lower rotor teeth 111 of the lower rotor is 45°. The main magnetic circuit distribution of this scheme is equivalent to that of the main magnetic circuit with the upper and lower rotors overlapping, and the magnetic circuit closed loop is formed along the path with the minimum magnetic resistance. This way of staggering the upper and lower rotors can make the rotor transition more smoothly during rotation and the torque ripple smaller.

[0037] Such as Figure 1 、 2 As shown in and 5, when this reluctance rotor is assembled with the corresponding stator into a magnetic levitation motor, the upper and lower rotor teeth are respectively substantially in a plane with the upper and lower radial arms of the first magnetic yoke of the corresponding stator. There is an air gap between the upper rotor teeth of the upper rotor and the upper radial arm of the first magnetic yoke, and there is an air gap between the lower rotor teeth of the lower rotor and the lower radial arm of the first magnetic yoke.

[0038] In order to realize the fixed installation of the upper rotor, the rotor and the connecting shaft, there are the following implementation methods: Such as Figure 9In the rotor connection method shown in A, the connecting shaft is a hollow tubular structure, and a through hole 121 is provided in the middle; the upper end of the connecting shaft is fixedly connected to the lower end surface of the upper rotor, and the lower end of the connecting shaft is fixedly connected to the upper end surface of the lower rotor; the main bodies of the upper rotor and the lower rotor are circular, and a central hole 14 aligned with the through hole of the connecting shaft is provided through the centers of the upper rotor and the lower rotor. The upper rotor and the lower rotor and the connecting shaft can be fixedly connected by means of bonding, ultrasonic welding, clamping, etc.

[0039] As Figure 9 In another rotor connection method shown in B, the connecting shaft is a hollow tubular structure, a through hole 121 is provided in the middle, and first plug-in parts 142 are respectively provided at the upper and lower ends of the connecting shaft. Second plug-in parts for plug-in cooperation with the first plug-in parts are provided at the central positions of the upper rotor and the lower rotor. On this basis, for strengthening the connection, the first plug-in part and the second plug-in part are also adhesively cooperated or other fixed connections are made. Optionally, the first plug-in part is a plug, and the second plug-in part is a jack for clamping with the plug. The installation of this plug-in connection method can be pre-installed by plugging, and then the connection strength between the upper and lower rotors and the connecting shaft is strengthened by other means. The installation accuracy is higher, and the problem of possible eccentric errors between the upper and lower rotors and the connecting shaft that may exist during the installation of the rotor in Embodiment 1 can be avoided.

[0040] The structure of the above reluctance rotor is simple, does not use any permanent magnet materials, greatly reduces the manufacturing cost of the rotor, also avoids the demagnetization problem caused by permanent magnet materials, has higher reliability, less eddy current, less heat generation, and less motor cooling cost.

[0041] As Figure 1 and Figure 4 As shown, compared with the existing stator structure, in the stator of this embodiment, an annular second yoke 23 is vertically provided in the middle of the first yoke group. Such a setting not only makes the second yoke fixedly connected to all the first yokes, but also enables the adjacent originally independently provided first yokes to achieve magnetic circuit connection through the second yoke.

[0042] During operation, two closed loops symmetrically distributed in the upper and lower radial directions are formed between the second yoke where the main magnetic path coil is located, the upper / lower parts of the first yokes on the left and right sides of each driving coil group, and the corresponding rotor teeth. The upper and lower two closed main magnetic paths share a part of the magnetic path in the second yoke.

[0043] In other embodiments, the position of the second yoke can be set at a position slightly above or below the middle of the axial arm of the first yoke, and can be adjusted according to needs. These deformation schemes all belong to the scope to be protected by this application. This scheme can improve the adverse effects caused by the offset of the rotor center of gravity due to load, such as rotor tilt, etc. This is because the magnetic path at the offset end of the second yoke is shorter, the magnetic resistance is smaller, and the relative output force is larger, which can effectively balance the influence brought by the center of gravity offset.

[0044] In the stator of this embodiment, the first yoke includes an axially disposed axial arm 21a and a radially extending radial arm 21b from at least one end of the axial arm towards the rotor. A first driving coil group 22 for driving the rotor to levitate and rotate is wound around the axial arm of the first yoke.

[0045] The second yoke 23 is vertically connected to the axial arm of the first yoke; the center of the annular second yoke is set to coincide with the rotor center axis of the rotor. In this embodiment, further, the second yoke 23 is vertically connected to the middle of the axial arm of the first yoke, so that the stator is symmetrically arranged up and down with the second yoke as the central axis.

[0046] In this embodiment, the first yoke includes an axially disposed axial arm 21a and radially extending radial arms 21b respectively from the upper and lower ends of the axial arm towards the rotor. The structure of the first yoke is in a similar C-shaped structure, and a first driving coil group 22 for driving the rotor to levitate and rotate is wound around the axial arm of the first yoke.

[0047] The stator with the above C-shaped first yoke is suitable for use in cooperation with the long-axis rotor of this embodiment. The upper and lower radial arms of the first yoke respectively correspond to the upper rotor teeth and the lower rotor teeth of the rotor, so as to form a closed magnetic circuit between the rotor teeth of two adjacent or non-adjacent long-axis rotors, the corresponding first yokes, and the second yoke part located between the two first yokes. The structure of this stator is simple, and the magnetic conductive backplane (used to facilitate the closed-loop setting of the magnetic circuit) provided at the bottom of the conventional stator can be omitted.

[0048] Specifically, in this embodiment, the number of the first yokes is 8, and the number of the rotor magnetic poles cooperating with them is 2, 4 or 6, etc.; in other embodiments, the number of the first yokes can also be 6, 10 or more, and the number of the rotor teeth of the rotor can be 2, 4 or 8; 2 or 4.

[0049] In the switched reluctance motor: LCM(N s , N r ) = q * N r , LCM(N s , N r ) > N s > N r q, where LCM is the least common multiple, q = N s / 2, q is the number of yoke pairs, N s is the number of yokes, N r is the number of rotor teeth.

[0050] In this embodiment, for the convenience of installing the second yoke and connecting it to the first yoke, and to ensure that magnetic lines of force can be connected between the second yoke and the adjacent first yoke, the following settings are made: A positioning hole is provided on the second yoke 23 for the axial arm of the first yoke to penetrate through, and the second yoke and the first yoke are fixedly connected, such as by bonding, screwing, welding, riveting or other fixed connection methods.

[0051] In other embodiments, the outer peripheral side wall / inner peripheral side wall of the second yoke is clamped and bonded to the inner side wall / outer side wall portion of the axial arm of the first yoke, or fixed connection is carried out in other ways.

[0052] The second yoke is composed of a plurality of second annular laminations stacked on each other along the stacking direction, and the stacking direction is set axially or radially. The first yoke is formed by laminating a plurality of first laminations along the stacking direction. The laminations can be made of silicon steel sheets.

[0053] In this embodiment, specifically, the second yoke is formed by a plurality of second annular laminations stacked up and down. The first yoke is formed by stacking a plurality of C-shaped first laminations back and forth. In other embodiments, the second yoke is formed by stacking a plurality of annular laminations arranged concentrically inside and outside.

[0054] As Figure 2 shown, each first drive coil group includes a suspension coil 22a for the suspension magnetic field of the rotor and a rotation coil 22b for providing a rotation magnetic field for the rotor. In this embodiment, a set of the above-mentioned first drive coil groups 22 are respectively provided above and below the second yoke. This method uses more coils, but has lower requirements for the control system. The suspension and rotation of the rotor can be independently controlled by controlling the suspension coil or the rotation coil respectively, and the control flexibility is higher.

[0055] Currently, in traditional longitudinally arranged yokes (or coil cores), due to their independent settings, during operation, in addition to forming a closed main magnetic circuit between the energized yoke and the corresponding rotor magnetic poles, the yoke will also release unused magnetic lines of force to the side directions other than the main magnetic circuit direction, resulting in relatively large magnetic leakage and low magnetic field utilization rate.

[0056] However, for the stator in the motor of this embodiment, since the annular second yoke connects the magnetic circuits between the mutually independent first yokes distributed in an annular shape, during operation, the magnetic leakage to the side in each originally independent first yoke can form other magnetic circuits through the connected annular yoke and be fully utilized, thereby improving the magnetic collection effect of the stator, increasing the utilization rate of the magnetic field, and further improving the working efficiency of the rotor.

[0057] On this basis, since the stator of this embodiment is symmetrically distributed up and down with the second yoke as the center of symmetry, there is a closed-loop main magnetic path symmetrically distributed up and down in the stator during operation. These two main magnetic paths are respectively controlled by two sets of first drive coil groups 22 distributed up and down, so as to realize the separate control of the rotational and levitation torques of the upper and lower parts of the rotor, improving the controllability and stability of the rotor.

[0058] The following takes the main magnetic path of the upper half of the motor stator as an example to illustrate the working principle. The main magnetic path of the lower half of the stator is symmetrically arranged with the magnetic path of the upper half, so it is omitted here.

[0059] Working principle of rotor rotation As Figure 1 and 5 shown, at a certain moment, the rotation coils on two first yokes 21 that are radially symmetric and not aligned with the rotor teeth are simultaneously energized, and magnetic force lines flowing axially upward (or downward) are excited at the same time. The main magnetic force lines respectively pass through a first yoke, the corresponding upper rotor tooth, flow horizontally to another rotor tooth of the upper rotor, another first yoke, and are closed through the second yoke between the two first yokes, forming two upper closed magnetic paths distributed left and right. Since the path of this magnetic path at the air gap is not the shortest distance, the rotor will rotate clockwise so that the magnetic force lines can be closed through the shortest distance. When this pair of first yokes is aligned with the upper rotor teeth of the rotor they pull, the rotation coils on another pair of first yokes arranged at a 90° angle to this pair of first yokes work in the same way as above and pull the rotor to rotate clockwise again. According to the above rules, the rotation coils at the corresponding positions in the stator are energized in turn, so as to realize the continuous rotation of the rotor.

[0060] In other cases, the rotation drive can also be controlled by using two pairs of cross-shaped C-shaped yokes at the same time according to the above rules to enhance the rotation driving force.

[0061] During the levitation process, opposite currents are passed through each pair of rotation coils and the magnetic path is closed through the transverse arm of the second yoke, and the upper and lower double-layer counterpoint magnetic paths are radially symmetric. This control method can also use a structure in which the upper and lower rotor teeth are misaligned, as long as the directions of the upper and lower layer magnetic paths flowing in the transverse yoke are the same, and the cooperative operation of the upper and lower magnetic paths can be realized. The rotational torque of the rotor can be increased by cooperatively controlling the rotation coils of the upper half and the lower half of the stator, improving the stability and accuracy of the rotor.

[0062] Working principle of rotor levitation As Figure 2As shown, the suspension of the rotor in this embodiment is mainly achieved by generating a suction force between the first magnetic yoke and the rotor. When the suspension coils on the first magnetic yoke of the stator are energized and the current magnitude is adjusted so that the tensile force (magnetic resistance torque) received by the rotor axially is equal, the rotor can achieve radial centered suspension. Thus, it can be seen that the axial suspension of the rotor in this embodiment is achieved by relying on the magnetic resistance principle of the shortest magnetic flux path closure.

[0063] At a certain moment, when the top of the rotor undergoes a radial offset, the suspension coils on the side with an increased air gap in the upper part of the stator will increase the current, causing the attractive force on this side to increase to correct the radial offset of the top of the rotor. Similarly, when the bottom of the rotor undergoes a radial offset, the suspension coils on the side with an increased air gap in the lower part of the stator will increase the current, causing the attractive force on this side to increase to correct the radial offset of the bottom of the rotor.

[0064] Therefore, this application can independently adjust the radial offset of the upper or lower part of the rotor, thereby not only improving the controllability of the radial horizontal offset and the up-and-down axial position offset of the rotor, but also realizing the regulation of the tilt angle of the rotor, converting its original passive control to active control, and thus greatly improving the stability of the rotor during high-speed operation.

[0065] In the case where the stability of the rotor is significantly improved, the stator can carry a larger working current during operation, which can significantly increase the torque of the rotor.

[0066] Figure 1 and Figure 2 Only the main magnetic circuit of this solution is shown in the figure, and other secondary magnetic circuits are omitted in the figure.

[0067] In this embodiment, the motor further includes a housing, and the above-mentioned first magnetic yoke and second magnetic yoke are arranged inside the housing and fixedly connected to the housing.

[0068] The motor further includes: a controller and a sensor that is control-connected to the controller. The sensor is used to detect the radial and axial positions and postures of the rotor, and the controller is used to regulate the current direction and magnitude of the first drive coil group and the second drive coil group.

[0069] For other structures provided inside the motor, refer to the prior art and are omitted here.

[0070] Embodiment 2 This embodiment provides a magnetic levitation motor, which is different from Embodiment 1 in that: only one first drive coil group 22 is wound and arranged on each first magnetic yoke 21, and this group of first drive coil groups 22 is located above or below the second magnetic yoke.

[0071] In the first implementation manner, as Figure 6 A and Figure 6As shown in Figure B, each first driving coil group 22 of the first driving coil group includes a suspension coil 22a for the suspension magnetic field of the rotor and a rotating coil 22b for providing a rotating magnetic field for the rotor. The first driving coil group is located above or below the second magnetic yoke. This method uses more coils, but has lower requirements for the control system. The suspension and rotation of the rotor can be independently controlled by controlling the suspension coil or the rotating coil respectively, and the control flexibility is higher.

[0072] In the second embodiment, as Figure 6 shown in Figure C, the first driving coil group 22 is a coil that simultaneously provides a rotating magnetic field and a suspension magnetic field for the rotor, and is arranged above or below the second magnetic yoke. In this setting, by controlling the coil on the first magnetic yoke, the rotating magnetic field and the suspension magnetic field provided by the stator for the rotor are adjusted simultaneously. This setting can simplify the coil arrangement and reduce the use cost of the coil, but has higher requirements for the control system of the stator.

[0073] In the third embodiment, as Figure 6 shown in Figure D, the suspension coil 22a and the rotating coil 22b of each first driving coil group are respectively arranged above and below the second magnetic yoke. Specifically, the suspension coil 22a is arranged at the position above the second magnetic yoke of each first magnetic yoke, and the rotating coil 22b is arranged at the position below the second magnetic yoke of each first magnetic yoke. In other cases, the positions of the suspension coil 22a and the rotating coil 22b are reversed. For other structural settings of the motor in this embodiment, refer to Embodiment 1.

[0074] In this embodiment, the suspension of the rotor is controlled by the suspension coil located above the second magnetic yoke, and the rotation of the rotor is controlled by the rotating coil located below the second magnetic yoke. Such a setting can reduce the difficulty of controlling the suspension and rotation of the rotor. Since the suspension coil 22a and the rotating coil 22b of the above-mentioned first driving coil group are respectively arranged in the upper half and the lower half of the stator, the suspension main magnetic path and the rotating main magnetic path are respectively distributed in the upper half or the lower half of the stator. For the working principle of the stator driving the mover to rotate and suspend, refer to Embodiment 1.

[0075] For the rotor structure of the motor in this embodiment and other structures of the stator, refer to Embodiment 1. Since the first driving coil group 22 in this embodiment is only arranged in the upper half or the lower half of the stator, its main magnetic path is only distributed in the upper half or the lower half, and the control method is not as flexible as that in Embodiment 1. For the working principle of the stator driving the mover to rotate and suspend, refer to Embodiment 1.

[0076] Embodiment 3 As Figures 7 - 8 shown, this embodiment provides a magnetic levitation motor, which includes: a rotor and a stator. For the structure of the rotor, refer to Embodiment 1.

[0077] The stator includes: the aforementioned first yoke group and an annular second yoke 23 fixedly arranged on the first yoke group, and the second yoke is connected to all the first yokes. The second yoke 23 is vertically connected to the middle of the axial arm of the first yoke. The center of the annular second yoke is set to coincide with the rotor center axis of the rotor. In this embodiment, the first yoke includes an axially arranged axial arm 21a and radial arms 21b radially extending from the upper and lower ends of the axial arm towards the rotor. The structure of the first yoke is in a similar C-shaped structure, and a first drive coil group 22 for driving the suspension and rotation of the rotor is wound on the axial arm of the first yoke. In this embodiment, each first drive coil group includes a suspension coil for the suspension magnetic field of the rotor and a rotation coil for providing a rotation magnetic field for the rotor.

[0078] On this basis, the improvement of the stator in this embodiment lies in that: a second drive coil group 24 for assisting in driving the suspension and rotation of the rotor is wound on the part (i.e., the connecting part) of the second yoke 23 located between two adjacent first yokes 21.

[0079] During operation, the first drive coil group 22 wound on the axial arm of the first yoke provides the main driving force for the suspension and rotation of the rotor, while the second drive coil group 24 arranged on the second yoke 23 plays an auxiliary adjustment role according to the state of the rotor, and is used to improve the control accuracy and stability of the rotor.

[0080] The specific principle is as follows: as Figure 8 shown, the thick black arrow represents the magnetic path formed by the first drive coil on the first yoke, and the light gray arrow represents the magnetic path of the second drive coil; the current direction and magnitude of the second drive coil can be adjusted to make the magnetic field generated by it enhance or weaken the magnetic path of the first drive coil.

[0081] Specifically, at a certain moment, such as when the rotor as a whole has a radial offset, in addition to adjusting the current of the first drive coil, the current of the second drive coil on the side with a larger stator air gap can also be increased to make the auxiliary magnetic path generated by the second drive coil consistent with the magnetic path of the first drive coil, so as to strengthen the original magnetic field; thereby increasing the attraction on this side to correct the radial offset of the rotor here.

[0082] Or, the current of the second drive coil on the side with a smaller stator air gap can also be decreased to make the auxiliary magnetic path generated by the second drive coil opposite to the magnetic path of the first drive coil, so as to cut down the original magnetic field here, thereby the radial offset of the rotor here.

[0083] In another case, when the rotor as a whole undergoes axial displacement (such as dropping), the current of the corresponding second drive coil is increased to enhance the axial suction force of the stator on the rotor, causing the rotor to move upward, correcting its axial displacement, and improving the axial stiffness.

[0084] For other settings of the stator in this embodiment, reference can be made to Embodiment 1.

[0085] In the motors of other embodiments, the second drive coil group 24 on the second yoke can also provide the main driving force for the suspension and levitation of the rotor, while the first drive coil group 22 distributed above and below the axial arm of the first yoke is used to independently and precisely assist in adjusting the upper and lower states of the rotor respectively, significantly improving the stability and control accuracy of the rotor.

[0086] It can be seen that due to the existence of two different drive coil groups in the motor of this embodiment, there are multiple adjustment methods for the stator, the control of the rotor is more flexible, variable, with more control dimensions, and the control accuracy and stability of the rotor are higher.

[0087] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. It can be understood that for those of ordinary skill in the art, equivalent replacements or changes can be made according to the technical solutions of the present invention and the concept of the present invention, and all such changes or replacements should fall within the protection scope of the appended claims of the present invention.

Claims

1. A novel reluctance type magnetic suspension bearingless motor, comprising a rotor (1) and a stator (2), characterized in that: The stator comprises: a first magnetic yoke group consisting of a plurality of first magnetic yokes (21) arranged longitudinally and arranged in a circumferential manner with the rotor as the center, and an annular second magnetic yoke (23) fixedly arranged on the first magnetic yoke group, the second magnetic yoke being fixedly connected to all the first magnetic yokes; the first magnetic yoke comprises an axial arm (21a) arranged longitudinally and a radial arm (21b) extending radially from at least one end of the axial arm toward the rotor, and a first driving coil group (22) for driving the rotor to suspend and rotate is wound around the axial arm of the first magnetic yoke; The rotor comprises a connecting shaft (12) and an upper rotor (11) and a lower rotor (13) fixed at both ends of the connecting shaft; the upper rotor extends in the direction of a radial arm at the top of a radial stator to form a plurality of upper rotor teeth (111) evenly distributed in the circumferential direction, and the lower rotor extends in the direction of a radial arm at the bottom of the radial stator to form a plurality of lower rotor teeth (131) evenly distributed in the circumferential direction; the upper rotor and the lower rotor are made of soft magnetic material.

2. The novel reluctance type magnetic suspension bearingless motor according to claim 1 is characterized in that: The connecting shaft (12) is made of soft magnetic material.

3. According to the novel reluctance type magnetic suspension bearingless motor as described in claim 2, an axially magnetized permanent magnet (121) is fixedly arranged in the connecting shaft.

4. The novel reluctance type magnetic suspension bearingless motor according to claim 1 is characterized in that: The connecting shaft is made of non-magnetic material.

5. The novel reluctance type magnetic suspension bearingless motor according to any one of claims 1 to 4, characterized in that: The upper rotor teeth (111) of the upper rotor and the lower rotor teeth (111) of the lower rotor are vertically symmetrical and are arranged in an overlapping or staggered manner.

6. The novel reluctance type magnetic suspension bearingless motor according to claim 5 is characterized in that: The second magnetic yoke (23) is vertically connected to the axial arm of the first magnetic yoke; the center of the annular second magnetic yoke is arranged to coincide with the rotor center axis of the rotor.

7. The novel reluctance type magnetic suspension bearingless motor according to claim 6 is characterized in that: The second magnetic yoke is vertically connected to the middle position of the first magnetic yoke.

8. The novel reluctance type magnetic suspension bearingless motor according to claim 2 is characterized in that: Radial arms (21b) extend from the upper and lower ends of the axial arm of the first magnetic yoke respectively.

9. The novel reluctance type magnetic suspension bearingless motor according to claim 1 is characterized in that: Each first drive coil group is a coil that simultaneously provides a rotating magnetic field and a suspension magnetic field for the rotor, and the first drive coil group (22) is arranged above the second magnetic yoke and / or below the second magnetic yoke.

10. The novel reluctance type magnetic suspension bearingless motor according to claim 1 is characterized in that: Each first drive coil group includes a suspension coil (22a) for providing a rotor suspension magnetic field and a rotating coil (22b) for providing a rotating magnetic field for the rotor. Each first drive coil group (22) is arranged above the second magnetic yoke and / or below the second magnetic yoke. Alternatively, the suspension coil (22a) and the rotating coil (22b) of each drive coil group are arranged at a position above or below the second magnetic yoke.

11. The novel reluctance type magnetic suspension bearingless motor according to any one of claims 1 to 10, characterized in that: A second drive coil group (24) for adjusting the suspension and rotation state of the rotor is wound around a portion of the second magnetic yoke located between two adjacent first magnetic yokes.

12. The novel reluctance type magnetic suspension bearingless motor according to claim 11 is characterized in that: Each group of second drive coil groups (24) comprises a suspension coil for providing a rotor suspension magnetic field and a rotation coil for providing a rotating magnetic field for the rotor.

13. The novel reluctance type magnetic suspension bearingless motor according to claim 12 is characterized in that: Also includes: A controller and a sensor connected to the controller for control, wherein the sensor is used to detect the radial and axial positions of the rotor, and the controller is used to adjust the current direction and magnitude of the first drive coil group and the second drive coil group.

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