CN101975224B - Magnetic suspension bearing of hybrid magnetic circuit - Google Patents

Abstract

A hybrid magnetic circuit magnetic suspension bearing relates to the technical field of magnetic suspension bearings. The invention overcomes the defects of large electric power, large volume and high weight of the existing magnetic suspension bearing. The four stator teeth in the stator iron core of the hybrid magnetic circuit magnetic suspension bearing of the present invention are evenly distributed on the inner surface of the annular yoke at an angle of 90°, and the circumferential width W _t of the stator teeth satisfies the condition: W _t <πD _i /4, Among them, D _i is the inner diameter of the stator core, and the part between the tooth ends facing the air gap of every two adjacent stator teeth is a permanent magnet poly yoke, and on the bisector of the permanent magnet poly yoke along the radial direction, there is a parallel The groove is embedded with a flat permanent magnet, and the permanent magnet is magnetized in parallel, and the magnetization direction is along the tangential direction. The rotor is cylindrical or cylindrical, and is composed of a magnetic conducting ring and a rotating shaft, and the magnetic conducting ring is sleeved on the outside of the cylindrical or cylindrical rotating shaft. The hybrid magnetic circuit magnetic suspension bearing of the invention has low loss and temperature rise, good control characteristics, small volume and light weight, and has broad application prospects.

Description

A Hybrid Magnetic Circuit Magnetic Suspension Bearing

technical field

The invention relates to a magnetic suspension bearing.

Background technique

Magnetic bearing, also known as active magnetic suspension bearing, is a new type of high-performance bearing without mechanical contact between the rotor and the stator. Compared with traditional ball bearings, sliding bearings and oil film bearings, magnetic suspension bearings use electromagnetic force to suspend the rotor in space, there is no mechanical contact between the stator and rotor, and the rotor can reach a very high speed, with small mechanical wear and energy consumption. Low noise, long life, no lubrication, no oil pollution, etc., especially suitable for special environments such as high speed, vacuum, and ultra-clean. It can be widely used in the fields of mechanical processing, turbomachinery, aerospace, petroleum and petrochemical, vacuum technology, energy, rotor dynamics characteristics identification and testing, and is recognized as a promising new type of bearing.

The basic structure of the traditional magnetic suspension bearing is shown in Figure 9. It is mainly composed of a stator and a rotor. The stator includes a stator core and a control coil. The control coil is wound on the teeth of the stator core. It is mainly based on the working principle of the electromagnet. The electromagnetic attraction between the rotors makes the rotors levitate, so a large current needs to be passed into the stator control coil, so that the electric power consumed by the bearing is large, and the heating of the coil is serious; if a small current is to be used to generate a large levitation force , It is necessary to reduce the air gap between the stator and rotor, which requires improving the working accuracy of the bearing. At the same time, the magnetic suspension bearing with this structure has a large volume and a high weight.

Contents of the invention

In order to solve the defects of large electric power, large volume and high weight of existing magnetic suspension bearings, the present invention proposes a novel hybrid magnetic circuit magnetic suspension bearing.

The hybrid magnetic circuit magnetic suspension bearing of the present invention includes a stator, a rotor and an air gap, and is characterized in that the stator is composed of a stator core, an excitation coil and an excitation permanent magnet. There are four through holes with fan-shaped end faces in the direction of rotor movement. The four through holes have the same shape and are distributed symmetrically with the central axis of the stator. Between two adjacent through holes are stator teeth. The stator teeth are along the The width W _t in the circumferential direction satisfies the condition: W _t <πD _i /4, where D _i is the inner diameter of the stator core, each stator tooth is wound with an excitation coil, and the part between the outer wall of the stator and the tooth root of the stator tooth is annular The yoke, the part between the four through holes of the stator and the air gap is a permanent magnet poly yoke, and a slot is opened in the middle of each poly yoke along the moving direction of the mover, and the slot radially runs through the In the permanent magnet poly yoke, a flat permanent magnet is embedded in each through slot, and the permanent magnet is magnetized in parallel, and the magnetization direction is along the tangential direction of the stator circumference, and the magnetization direction of every two adjacent permanent magnets is opposite. The rotor is cylindrical or cylindrical, and is composed of a magnetic conducting ring and a rotating shaft, and the magnetic conducting ring is sleeved on the outer surface of the cylindrical or cylindrical rotating shaft.

The present invention also provides another hybrid magnetic circuit magnetic suspension bearing, which includes a stator, a rotor, and an air gap. The stator includes a stator core, an excitation coil, and an excitation permanent magnet. It is characterized in that four stator teeth are evenly distributed along the circumferential direction , the width W _t of each stator tooth along the circumferential direction satisfies the condition: W _t <πD _i /4, where D _i is the inner diameter of the stator core, and an excitation coil is wound on each stator tooth; Between them is the groove of the stator core, the part of the stator core located at the root of the stator teeth is a magnetically conductive yoke, and the part of the stator core located between two adjacent stator teeth is a permanent magnet collecting yoke, and the permanent magnet collecting yoke is Mirror symmetrical structure, on the inner wall of each permanent magnet poly yoke, there is a permanent magnet groove along its mirror symmetric plane, the permanent magnet groove runs through the permanent magnet poly yoke along the moving direction of the mover, in each A flat permanent magnet is embedded in the permanent magnet groove, and the permanent magnet is magnetized in parallel, the magnetization direction is the tangential direction along the circumference, and the magnetization directions of two adjacent flat permanent magnets are opposite, and the rotor is a cylinder Shaped or cylindrical, it is composed of a magnetically conductive ring and a rotating shaft, and the magnetically conductive ring is sleeved on the outside of the cylindrical or cylindrically shaped rotating shaft.

The hybrid magnetic circuit magnetic suspension bearing of the present invention utilizes the high-performance rare earth permanent magnet 2 in the magnetic suspension bearing to generate a DC magnetic flux bias in the magnetic circuit of the bearing, which can effectively reduce the ampere-turns of the electric excitation, Reduce the volume and weight of the bearing, reduce the loss and temperature rise of the bearing, and improve the dynamic response and control accuracy of the bearing.

The hybrid magnetic circuit magnetic suspension bearing of the invention has low loss and temperature rise, good control characteristics, small volume and light weight, and has broad application prospects.

Description of drawings

Fig. 1 is a radial sectional view of the magnetic suspension bearing described in Embodiment 1 of the present invention. Fig. 2 is a radial sectional view of the magnetic suspension bearing described in Embodiment 2. Fig. 3 is a radial sectional view of the magnetic suspension bearing described in Embodiment 4. Fig. 4 is a radial sectional view of the magnetic suspension bearing described in Embodiment 5. Fig. 5 is a radial sectional view of the magnetic suspension bearing described in Embodiment 8. Fig. 6 is a radial sectional view of the magnetic suspension bearing described in Embodiment 9. Fig. 7 is a radial sectional view of the magnetic suspension bearing described in Embodiment 10. Fig. 8 is a sectional view along A-A of Fig. 7 . Fig. 9 is a radial sectional view of the basic structure of a conventional magnetic suspension bearing.

Detailed ways

Embodiment 1: The hybrid magnetic circuit magnetic suspension bearing of this embodiment is composed of a stator, a rotor and an air gap. The stator is composed of a stator core, an excitation coil 5 and an excitation permanent magnet 2. The end face of the stator core is circular, and on the side of the stator In the wall, there are four through holes 6 with fan-shaped end faces along the moving direction of the rotor. The four through holes 6 have the same shape and are distributed symmetrically with the central axis of the stator. Between two adjacent through holes 6 are The stator tooth 4, the width W _t of the stator tooth 4 along the circumferential direction satisfies the condition: W _t <πD _i /4, wherein, D _i is the inner diameter of the stator core, each stator tooth 4 is wound with an excitation coil 5, and the outer wall of the stator to The part between the tooth roots of the stator teeth 4 is an annular yoke, and the part between the four through holes 6 of the stator and the air gap is a permanent magnet poly yoke 3, which is located in the middle of each poly yoke along the moving direction of the mover. There is a through slot, and the through slot radially runs through the permanent magnet poly yoke 3, and a flat permanent magnet 2 is embedded in each through slot, and the permanent magnet 2 is magnetized in parallel, and the magnetization direction is along the circumference of the stator. In the tangential direction, the magnetization directions of every two adjacent permanent magnets 2 are opposite, the rotor is cylindrical or cylindrical, and consists of a magnetic conducting ring and a rotating shaft, and the magnetic conducting ring is sleeved on the outer surface of the cylindrical or cylindrical rotating shaft .

Referring to FIG. 1 , FIG. 1 is a radial cross-sectional view of the case where the rotor in this embodiment is a cylinder.

Specific Embodiment 2: Refer to FIG. 2 to illustrate this embodiment. The difference between the present embodiment and the first embodiment is that an axial magnetic isolation hole 7 is provided at the connection between each stator tooth 4 and the adjacent permanent magnet collecting yoke 3 .

In this embodiment, a magnetic isolation hole 7 is added at the connection between the permanent magnet yoke 3 and the stator tooth 4, which can effectively reduce the mutual influence between the magnetic flux of the permanent magnet 2 and the electric excitation flux, and improve the control accuracy of the bearing.

Specific Embodiment Three: The hybrid magnetic circuit magnetic suspension bearing of this embodiment is mainly composed of a stator, a rotor and an air gap. The stator includes a stator core, an excitation coil 5 and an excitation permanent magnet 2. The inner wall of the stator core is evenly distributed along the circumferential direction with four stator teeth. 4. The width W _t of each stator tooth 4 along the circumferential direction satisfies the condition: W _t <πD _i /4, where D _i is the inner diameter of the stator core, and each stator tooth 4 is wound with an excitation coil 5; every two adjacent Between the two stator teeth 4 is the groove of the stator core, the stator core part located at the root of the stator teeth 4 is the magnetic conduction yoke 1, and the stator core part located between two adjacent stator teeth 4 is the permanent magnet polymagnetic yoke 3 , the permanent magnet poly yoke 3 is a mirror image symmetrical structure, on the inner wall of each permanent magnet poly yoke 3, there is a permanent magnet groove along its mirror image symmetry plane, and the permanent magnet groove runs through along the moving direction of the mover The permanent magnet poly yoke 3 is embedded with a flat permanent magnet 2 in each permanent magnet groove, and the permanent magnet 2 is magnetized in parallel, and the magnetization direction is a tangential direction along the circumference, and two adjacent The magnetization direction of two flat permanent magnets 2 is opposite, and the rotor is cylindrical or cylindrical, and is made of magnetic conducting ring and rotating shaft, and magnetic conducting ring is enclosed within the outside of cylindrical or cylindrical rotating shaft.

The difference between the magnetic suspension bearing described in this embodiment and the magnetic suspension bearing described in Embodiment 1 lies in that the positions of the permanent magnet poly yoke 3 and the permanent magnet 2 are different.

Embodiment 4: The difference between this embodiment and Embodiment 3 is that the outside of the end surface of the stator is a square, and the four vertices of the square are respectively located in the mirror symmetry planes of the four permanent magnet poly yokes 3 .

Referring to Fig. 3, the outside of the end surface of the stator in this embodiment is a square, the magnetic yoke 1 is located at 0°, 90°, 180°, and 270° in the circumferential direction, and the permanent magnet polymagnetic yoke 3 is located at 45°, 270° in the circumferential direction. At the positions of 135°, 225°, and 315°, four stator teeth 4 are evenly distributed on the inner surface of the magnetic yoke 1 at an angle of 90°.

Fifth specific embodiment: see FIG. 4 . The difference between this embodiment and the third embodiment is that the outer side of the end face of the stator is a centrosymmetric figure composed of four straight line segments and four circular arc segments, and the outer side corresponding to the position of the magnetic yoke 1 is a straight line segment, which is the same as The corresponding outer side of the permanent magnet poly yoke 3 is an arc segment.

Specific embodiment six: refer to FIG. 5 . The difference between this embodiment and the third embodiment is that the outer end surface of the stator is circular.

Embodiment 7: The difference between this embodiment and Embodiments 3, 4, 5, 6 or 7 is that the inner side of the radial section of the permanent magnet poly yoke 3 is a smooth arc. See Figures 3 and 4.

Embodiment 8: The difference between this embodiment and Embodiments 3, 4, 5, 6 or 7 is that there is a protrusion toward the inner side of the groove in the middle of the permanent magnet poly yoke 3 .

The protrusions described in this embodiment are radially symmetrical structures. For example, its cross-section may be a trapezoid, and the two hypotenuses of the trapezoid are respectively parallel to the sides of the adjacent stator teeth 4 . See Figure 5.

Embodiment 9: The main difference between this embodiment and Embodiment 3 is that each stator tooth 4 has two slots parallel to each other along the tooth height direction, and the slots pass through the stator teeth 4 along the moving direction of the mover. The excitation coil 5 is embedded in the two slots.

Referring to Fig. 6, the stator tooth 4 in this embodiment has two parallel slots along the tooth height direction and the axial direction, and the stator tooth 4 forms three tooth-shaped structures, and the excitation coil 5 is wound in the middle tooth-shaped Structurally, and embedded in two slots.

Embodiment 10: The main difference between this embodiment and Embodiment 3 is that each stator tooth 4 is also embedded with an axial position control coil 8, and the plane where the control coil 8 is located is perpendicular to the plane where the excitation coil 5 is located, and The control coil 8 can generate magnetic flux along the moving direction of the mover.

The method of embedding the control coil 8 in the stator tooth 4 can be embedded in the manner of slotting in the stator tooth 4 , or the stator tooth 4 can be divided into two mirror-symmetrical parts, and the control coil 8 is sandwiched between them.

Next, referring to Figs. 7 and 8, the method of embedding the control coil 8 in the manner of slotting and embedding in the stator teeth 4 will be described in detail:

There are also four annular grooves symmetrical to the rotor axis on the stator. Each annular groove is composed of four sections of grooves, of which the first section is located in the middle of the ends of the stator teeth 4 in the axial direction, and the second section, The third section is respectively located on the two axial end surfaces of the stator teeth 4, the fourth section is located in the middle of the magnetic yoke 1 corresponding to the stator teeth 4, the central axis of the motor is located in the plane where the annular groove is located, and the control coil 8 Fit into the ring groove.

In this embodiment, the axial position control coil 8 is added to realize the control of the axial position of the rotor, that is, the axial position of the rotor can be controlled by controlling the current in the coil.

Embodiment 11: The main difference between this embodiment and Embodiments 1 to 10 is that the magnetic force generated by the two permanent magnets 2 on the upper side is greater than that generated by the two permanent magnets 2 on the lower side.

In this embodiment, the relationship between the magnetic field force generated by the two permanent magnets 2 on the upper side and the magnetic field force generated by the two permanent magnets 2 on the lower side is further defined, so as to achieve a relative static state between the mover and the stator , the magnetic field force generated by the stator can overcome the gravity of the mover itself, so that the mover can be suspended in the center of the stator.

Concrete technical means can adopt: make the magnetization direction length of two permanent magnets 2 on the upper side greater than or equal to the magnetization direction length of the two permanent magnets 2 on the lower side; or the diagonal direction length of the two permanent magnets 2 on the upper side is greater than or equal to the two The diagonal length of the permanent magnets 2; or the thickness of the two permanent magnets 2 on the upper side is greater than the thickness of the two permanent magnets 2 on the lower side.

Claims (10)

1. A hybrid magnetic circuit magnetic suspension bearing, comprising a stator, a rotor and an air gap, is characterized in that the stator is made of a stator core, an excitation coil (5) and an excitation permanent magnet (2), and the end face of the stator core is a circular ring, in the In the side wall of the stator, there are four through holes (6) with fan-shaped end faces along the moving direction of the rotor. The four through holes (6) have the same shape and are distributed symmetrically with the central axis of the stator. Between the through holes (6) are stator teeth (4), and the width W _t of the stator teeth (4) along the circumferential direction satisfies the condition: W _t <πD _i /4, where D _i is the inner diameter of the stator core, and each stator The teeth (4) are wound with excitation coils (5), the part between the outer wall of the stator and the root of the stator teeth (4) is an annular yoke, and the part between the four through holes (6) of the stator and the air gap is a permanent The magnetic poly yoke (3) has a slot in the middle of each poly yoke along the moving direction of the rotor, and the slot radially runs through the permanent magnet poly yoke (3), and each slot is embedded A plate-shaped permanent magnet (2), the permanent magnet (2) is magnetized in parallel, and the magnetization direction is along the tangential direction of the stator circumference, the magnetization direction of every two adjacent permanent magnets (2) is opposite, and the rotor is a cylinder Shaped or cylindrical, it is composed of a magnetic conducting ring and a rotating shaft, and the magnetic conducting ring is sleeved on the outer surface of the cylindrical or cylindrical rotating shaft. 2. A hybrid magnetic circuit magnetic suspension bearing according to claim 1, characterized in that an axial spacer is provided at the connection between each stator tooth (4) and the adjacent permanent magnet poly yoke (3). Magnetic holes (7). 3. A hybrid magnetic circuit magnetic suspension bearing, which includes a stator, a rotor and an air gap, and the stator includes a stator core, an excitation coil (5) and an excitation permanent magnet (2), and is characterized in that the inner wall of the stator core is uniformly distributed along the circumferential direction with four stator teeth (4), the width W _t of each stator tooth (4) along the circumferential direction satisfies the condition: W _t <πD _i /4, where D _i is the inner diameter of the stator core, and each stator tooth (4) is wound on There is an excitation coil (5); between every two adjacent stator teeth (4) is the groove of the stator core, and the part of the stator core located at the root of the stator teeth (4) is a magnetically permeable yoke (1), which is located between two adjacent stator teeth (4). The stator core part between the two stator teeth (4) is a permanent magnet poly yoke (3), and the permanent magnet poly yoke (3) is a mirror image symmetrical structure, and the inner side wall of each permanent magnet poly yoke (3) There is a permanent magnet groove on the top and along its mirror image symmetry plane, the permanent magnet groove runs through the permanent magnet poly yoke (3) along the moving direction of the rotor, and a flat permanent magnet is embedded in each permanent magnet groove (2), the permanent magnets (2) are magnetized in parallel, the magnetization direction is a tangential direction along the circumference, and the magnetization directions of two adjacent flat permanent magnets (2) are opposite, and the rotor is cylindrical or circular Cylindrical, consisting of a magnetic conducting ring and a rotating shaft, the magnetic conducting ring is sleeved on the outside of a cylinder or a cylindrical rotating shaft. 4. A kind of hybrid magnetic circuit magnetic suspension bearing according to claim 3, characterized in that, the outer side of the end face of the stator is a square, and the four vertices of the square are respectively located in the four permanent magnet poly-magnetic yokes (3 ) in the mirror symmetry plane. 5. A hybrid magnetic circuit magnetic suspension bearing according to claim 3, characterized in that, the outer side of the end face of the stator is a centrosymmetric figure composed of four straight line segments and four circular arc segments, and is connected to the magnetic yoke ( 1) The outer side corresponding to the position is a straight line segment, and the outer side corresponding to the permanent magnet poly yoke (3) is an arc segment. 6. A hybrid magnetic circuit magnetic suspension bearing according to claim 3, 4 or 5, characterized in that the inner side of the radial section of the permanent magnet poly yoke (3) is a smooth arc. 7. A hybrid magnetic circuit magnetic suspension bearing according to claim 3, 4 or 5, characterized in that there is a protrusion toward the inner side of the groove in the middle of the permanent magnet poly yoke (3). 8. A hybrid magnetic circuit magnetic suspension bearing according to claim 3, characterized in that, each stator tooth (4) is provided with two parallel slots along the tooth height direction, and the slots run through along the rotor moving direction The stator teeth (4), the excitation coil (5) are embedded in the two slots. 9. A hybrid magnetic circuit magnetic suspension bearing according to claim 3, characterized in that, each stator tooth (4) is also embedded with an axial position control coil (8), and the plane where the control coil (8) is located The plane where the exciting coil (5) is located is perpendicular to each other, and the control coil (8) can generate magnetic flux along the moving direction of the rotor. 10. A hybrid magnetic circuit magnetic suspension bearing according to claim 1 or 3, characterized in that the magnetic force generated by the two permanent magnets (2) on the upper side is greater than the magnetic field generated by the two permanent magnets (2) on the lower side force.

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