CN111425523A - A hybrid radial permanent magnet bias magnetic bearing - Google Patents

Abstract

The invention discloses a hybrid radial permanent magnet bias magnetic bearing, comprising a stator iron core, a rotor, a rotating shaft, a permanent magnet and an electromagnetic control coil; the stator iron core includes eight electromagnetic control magnetic poles and two permanent magnet bias magnetic poles; a permanent magnet The magnets are pasted at the positions of the two permanent magnetic bias pole pieces; each electromagnetic control magnetic pole is provided with an electromagnetic control coil, and the two electromagnetic control coils of each group are connected in series. The invention belongs to the hybrid magnetic suspension bearing with different polarity and permanent magnet bias, adopts the stator iron core of the traditional eight-pole motor as the main bearing structure, and adds two-pole permanent magnet bias magnetic poles on the upper side, and the permanent magnet bias magnetic poles provide permanent Magnetic bias force can improve the static bearing capacity of the bearing, reduce the loss, improve the utilization rate of the magnetic circuit of the stator core and the maximum bearing capacity of the bearing, thereby reducing the volume of the magnetic bearing, suitable for high-speed rotation of high-speed motors, flywheel systems, centrifuges, etc. Contactless support for the system.

Description

A hybrid radial permanent magnet bias magnetic bearing

technical field

The invention belongs to the field of electrical and mechanical transmission equipment, and more specifically relates to a hybrid radial permanent magnet bias magnetic bearing.

Background technique

Magnetic bearing is a new type of bearing that uses magnetic field force as a supporting force to suspend the rotor in space. It has the characteristics of no contact, no lubrication and no wear. It can be used in special environments such as vacuum technology, clean room and sterile workshop. .

Due to the shortcomings of the traditional active magnetic bearing that the bearing capacity is small, and a large bias current is required to maintain the rotor suspension during operation, the permanent magnet is added to the active magnetic bearing by using the inherent magnetic characteristics of the permanent magnet material. Reduce the bias current of the electromagnet. Due to the strong magnetic field of permanent magnets and better magnetic performance, the use of permanent magnets instead of electromagnets can reduce the volume of magnetic bearings. However, the traditional hybrid magnetic bearing mostly adopts the combination of different polarity active bearings and homopolar permanent magnet bearings, and the magnetic circuit design is complicated. At this time, the increase of the structural complexity actually increases the system volume.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of large power consumption and low utilization rate of magnetic circuit when the active radial active magnetic bearing is used alone, as well as the problems of large volume and complex structure of the traditional hybrid magnetic bearing, and proposes a different The improved structure of the polar hybrid magnetic bearing, that is, a hybrid radial permanent magnet bias magnetic bearing, uses the stator core of the traditional eight-pole motor as the main bearing structure, and adds two-pole permanent magnet bias magnetic poles on the upper side. The magnetic poles provide permanent magnetic bias force, which can improve the static bearing capacity of the bearing, reduce the loss, improve the utilization rate of the magnetic circuit of the stator core and the maximum bearing capacity of the bearing, thereby reducing the volume of the magnetic bearing; this structure can simplify the processing technology, reduce the Manufacturing cost, and improve the working performance of the magnetic bearing.

The object of the present invention is achieved through the following technical solutions.

The hybrid radial permanent magnetic bias magnetic bearing of the present invention includes a stator core, a rotor, a rotating shaft, a permanent magnet and an electromagnetic control coil; the rotating shaft, the rotor and the stator core are sequentially arranged from the inside to the outside along the coaxial line, and the The rotor and the rotating shaft are fixedly arranged, and an air gap is left between the rotor and the stator core;

The inner circle of the stator iron core is provided with eight radially protruding electromagnetic control magnetic poles, which are divided into four groups, up and down, left and right, each group contains two electromagnetic control magnetic poles, and the eight electromagnetic control magnetic poles are symmetrical about the diameter line in the Y-axis direction. , the eight electromagnetic control poles are symmetrical about the diameter line in the X-axis direction; there are permanent magnet bias poles between the upper electromagnetic control pole and the left and right electromagnetic control poles, and the two permanent magnet bias poles are left and right about the diameter line in the Y-axis direction symmetry;

The permanent magnets are respectively pasted at the positions of the two permanent magnet bias magnetic pole pieces; each of the electromagnetic control magnetic poles is provided with an electromagnetic control coil, and the two electromagnetic control coils on each group of electromagnetic control magnetic poles are connected in series, and eight The winding direction of the electromagnetic control coil is left-right symmetrical with respect to the diameter line in the Y-axis direction, and symmetrical with respect to the diameter line in the X-axis direction.

The width and length of the eight electromagnetic control magnetic poles are exactly the same, and the angle between the upper two electromagnetic control magnetic poles and the diameter line in the Y-axis direction is smaller than the angle between the two electromagnetic control magnetic poles on the left and the diameter line in the X-axis direction. , the angle between the upper two electromagnetic control poles and the diameter line in the Y-axis direction is smaller than the angle between the two electromagnetic control poles on the right side and the diameter line in the X-axis direction; the width of the permanent magnet bias pole is smaller than the electromagnetic control pole width, the length of the permanent magnet bias pole is the same as the length of the electromagnetic control pole.

The permanent magnet is a tile structure, the permanent magnet and the permanent magnet bias magnetic pole are in contact with the radian, the width of the permanent magnet is larger than the width of the permanent magnetic bias magnetic pole, and the thickness of the pole shoe of the electromagnetic control magnetic pole is the same; the The axial length of the permanent magnet and the stator core are equal and the axial edges are flush with each other; the magnetizing angle of the permanent magnet is symmetrical about the diameter line in the Y-axis direction, both of which are radially magnetized, and the magnetizing direction is radially opposite, and the left The S pole of the permanent magnet faces the rotor, and the N pole of the right permanent magnet faces the rotor.

Compared with the prior art, the beneficial effects brought by the technical solution of the present invention are:

(1) The present invention adds a permanent magnetic bias magnetic pole by constructing a permanent magnetic bias magnetic circuit without affecting the reluctance of the electromagnetically controlled magnetic circuit. Under the condition of generating the same amount of levitation force, this structure greatly reduces the space size of the magnetic bearing, making the entire bearing smaller and lighter in weight.

(2) The present invention reduces the angle between the upper electromagnetic control magnetic pole and the Y axis, thereby increasing the resultant force of the electromagnetic attraction force. When passing the same current, it can provide greater electromagnetic force, and the dynamic response performance of the magnetic bearing is better, which is convenient for the stable control of the magnetic bearing when the load has dynamic disturbance.

(3) The present invention uses two radially magnetized permanent magnets on the upper side to provide a static bias magnetic field to provide a static levitation force for the magnetic bearing. Since the static bias magnetic field does not require additional iron core path closure, it is compatible with the electrical excitation. The magnetic circuit of the magnetic poles is consistent, and the utilization rate of the magnetic circuit of the stator core is effectively improved.

(4) The permanent magnet bias magnetic pole added in the present invention is formed by laminating silicon steel sheets, which can reduce the eddy current loss of the stator, and has a simple manufacturing process and low cost.

(5) The permanent magnet added in the present invention improves the radial magnetic density of the air gap and increases the maximum bearing capacity of the magnetic bearing. The resultant force of the permanent magnets on the rotor is vertically upward, which is used to offset the gravity of the rotor itself, thereby eliminating the bias current provided to overcome the self-weight of the rotor, and the current loss is greatly reduced.

(6) The present invention optimizes the cogging structure, and the permanent magnet bias magnetic pole is narrower, so that there is more space for accommodating the current coil winding. At the same time, the permanent magnet is slightly wider than the permanent magnet bias magnetic pole, which is convenient for fixing the coil winding, and increases the cross-sectional area of the air-gap magnetic flux, thereby further improving the electromagnetic force.

Description of drawings

Fig. 1 is the structural front view of the hybrid radial permanent magnet bias magnetic bearing of the present invention;

FIG. 2 is a schematic diagram of the current direction and the magnetic lines of force of the control current coil of the present invention.

Reference signs: 1-stator core, 2-rotor, 3-rotating shaft, 4-air gap, 5-permanent magnet, 6-electromagnetic control coil, 7-permanent magnet bias flux, 8-electromagnetic control flux.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in FIG. 1 , the hybrid radial permanent magnet bias magnetic bearing of the present invention includes a stator core 1 , a rotor 2 , a rotating shaft 3 , a permanent magnet 5 and an electromagnetic control coil 6 . The rotating shaft 3, the rotor 2 and the stator core 1 are arranged in sequence from the inside to the outside along the coaxial line, and the rotor 2 and the rotating shaft 3 are fixedly arranged, and an air gap 4 is left between the rotor 2 and the stator core 1. . The stator core 1 is formed by laminating silicon steel sheets, the rotor 2 is sleeved on the rotating shaft 3, and placed together in the stator core cavity formed by laminating silicon steel sheets. The axial length of the rotor 2 is equal to and flat with the stator core 1. together.

The inner circle of the stator core 1 is provided with eight radially protruding electromagnetic control magnetic poles, which are divided into four groups of up, down, left and right, each group contains two electromagnetic control magnetic poles, and the eight electromagnetic control magnetic poles are about the diameter line of the Y-axis direction left and right. Symmetrical, the eight electromagnetic control magnetic poles are symmetrical about the X-axis diameter line up and down. The width and length of the eight electromagnetic control magnetic poles are exactly the same, and the angle between the upper two electromagnetic control magnetic poles and the diameter line in the Y-axis direction is smaller than the angle between the two electromagnetic control magnetic poles on the left and the diameter line in the X-axis direction. , the angle between the upper two electromagnetic control poles and the diameter line in the Y-axis direction is smaller than the angle between the two electromagnetic control poles on the right side and the diameter line in the X-axis direction.

A radially protruding permanent magnet bias magnetic pole is arranged between the upper electromagnetic control magnetic pole and the left and right two sets of electromagnetic control magnetic poles. The width of the two permanent magnet bias magnetic poles is smaller than the width of the electromagnetic control magnetic pole, and the length of the permanent magnetic bias magnetic pole is the same as the length of the electromagnetic control magnetic pole.

The permanent magnets 5 are respectively pasted at the positions of the two permanent magnet bias magnetic pole pieces, and the magnetization angles of the two permanent magnets 5 are symmetrical about the diameter line in the Y-axis direction, both of which are radially magnetized, and the magnetization directions are radially opposite. , the S pole of the left permanent magnet faces the rotor, and the N pole of the right permanent magnet faces the rotor. The permanent magnet 5 is a tile structure, and the permanent magnet 5 is closely attached to the contact point of the permanent magnet bias magnetic pole, and the radian is the same. The pole shoe thicknesses are the same. The permanent magnet 5 is made of rare earth NdFeB, has the same axial length as the stator core 1 and the axial edges are flush with each other, and has an air gap 4 between the rotor 2 .

Each of the electromagnetic control magnetic poles is provided with an electromagnetic control coil 6, and the two electromagnetic control coils 6 on each group of electromagnetic control magnetic poles are connected in series, and have no electrical connection relationship with other electromagnetic control coils 6; the eight electromagnetic control coils The winding direction of the coil 6 is left-right symmetrical with respect to the Y-axis direction diameter line, and vertically symmetrical about the X-axis direction diameter line.

The energization direction of the electromagnetic control coil 6 is shown in Figure 2: in the figure, "O" is the vertical paper surface outward, and "X" is the vertical paper surface inward. The magnetic field lines generated by the upper electromagnetic control magnetic pole and the two permanent magnets 5 are taken as an example: the current direction of the electromagnetic control coil 6 wound by the upper left electromagnetic control magnetic pole is the left side flowing out of the paper, and the right magnetic pole flowing into the paper. Therefore, the direction of the electromagnetic control magnetic flux 8 generated is radially upward, which corresponds to the S pole toward the rotor side magnetic pole. Similarly, the direction of the electromagnetic control magnetic flux 8 generated by the electromagnetic control magnetic pole on the upper right is downward in the radial direction, which is equivalent to the N pole of the magnetic pole on the rotor side. At this time, the electromagnetic control magnetic flux 8 of the upper two electromagnetic control magnetic poles is closed in a clockwise direction, that is, the electromagnetic control magnetic flux 8 follows the upper left electromagnetic control magnetic pole, the upper magnetic yoke, the upper right electromagnetic control magnetic pole, and the air gap 4 in the stator core 1. , The rotor 2 forms a closed loop. For the two additional permanent magnet bias poles, the left permanent magnet is oriented with the S pole facing the rotor, and the right permanent magnet is oriented with the N pole facing the rotor. The path of the magnetic field lines generated by the two permanent magnets 5 is: radially upward along the left permanent magnet bias pole, rightward through the upper yoke, radially downward along the right permanent magnet bias pole, through the air gap 4, the rotor 2 The interior goes to the left and returns to the left permanent magnet to form a closed loop. The permanent magnet bias magnetic flux 7 and the electromagnetic control magnetic flux 8 are in contact with the rotor surface at the air gap, and an electromagnetic force perpendicular to the rotor surface is generated. The electromagnetic force is symmetrical and equal in magnitude, and the resultant force is the positive direction of the Y-axis. In the same way, the resultant force generated by the lower two electromagnetic control poles is the negative direction of the Y axis, the resultant force generated by the two electromagnetic control poles on the left is the negative direction of the X axis, and the resultant force generated by the two electromagnetic control poles on the right side is the positive direction of the X axis. direction. By controlling the magnitude of the current in the corresponding electromagnetic control coil 6, the electromagnetic attraction force in the corresponding direction can be controlled, thereby overcoming external disturbances and maintaining the stable suspension of the rotor 2 at the set position.

Although the functions and working process of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the scope of the present invention and the protection scope of the claims, which all belong to the protection of the present invention.

Claims (3)

1. A hybrid radial permanent magnet bias magnetic bearing, characterized in that it comprises a stator core (1), a rotor (2), a rotating shaft (3), a permanent magnet (5) and an electromagnetic control coil (6); The rotating shaft (3), the rotor (2) and the stator core (1) are sequentially arranged from the inside to the outside along the coaxial line, and the rotor (2) and the rotating shaft (3) are fixedly arranged, and the rotor (2) There is an air gap (4) between the stator core (1); The inner circle of the stator iron core (1) is provided with eight radially protruding electromagnetic control magnetic poles, which are divided into four groups: up, down, left and right, each group contains two electromagnetic control magnetic poles, and the eight electromagnetic control magnetic poles are about the diameter of the Y-axis direction. The line is symmetrical on the left and right, and the eight electromagnetic control poles are symmetrical about the X-axis diameter; there are permanent magnet bias poles between the upper electromagnetic control pole and the left and right electromagnetic control poles, and the two permanent magnet bias poles are about the Y-axis direction. The diameter line is symmetrical left and right; The permanent magnets (5) are respectively pasted at the positions of two permanent magnet bias magnetic pole pieces; each of the electromagnetic control magnetic poles is provided with an electromagnetic control coil (6), and two electromagnetic control coils on each group of electromagnetic control magnetic poles are provided (6) Connected in series, and the winding directions of the eight electromagnetic control coils (6) are symmetrical about the diameter line in the Y-axis direction, and symmetrical about the diameter line in the X-axis direction. 2 . The hybrid radial permanent magnetic bias magnetic bearing according to claim 1 , wherein the width and length of the eight electromagnetic control magnetic poles are exactly the same, and the upper two electromagnetic control magnetic poles are the diameter lines in the Y-axis direction. 3 . The angle between them is smaller than the angle between the two electromagnetic control poles on the left and the diameter line in the X-axis direction, and the angle between the upper two electromagnetic control poles and the diameter line in the Y-axis direction is smaller than the angle between the two electromagnetic control poles on the right The angle between the diameter line in the X-axis direction; the width of the permanent magnet bias magnetic pole is smaller than the width of the electromagnetic control magnetic pole, and the length of the permanent magnetic bias magnetic pole is the same as the length of the electromagnetic control magnetic pole. 3 . The hybrid radial permanent magnet bias magnetic bearing according to claim 1 , wherein the permanent magnet ( 5 ) is a tile structure, and the permanent magnet ( 5 ) is in contact with the permanent magnet bias magnetic pole. 4 . The width of the permanent magnet (5) is larger than the width of the permanent magnet bias magnetic pole, and is the same as the thickness of the pole piece of the electromagnetically controlled magnetic pole; the axial length of the permanent magnet (5) and the stator core (1) are equal and the shaft The magnetization angles of the permanent magnets (5) are symmetrical with respect to the diameter line in the Y-axis direction, both of which are radially magnetized, and the magnetization directions are radially opposite, with the S pole of the left permanent magnet facing the rotor, and the right The N poles of the side permanent magnets face the rotor.

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