CN1277060C - A Low Power Consumption Permanent Magnet Bias Inner Rotor Radial Magnetic Bearing - Google Patents

Abstract

Low power consumption permanent magnet bias inner rotor radial magnetic bearing, composed of outer magnetic ring, permanent magnet, stator core, excitation coil, inner magnetic ring, rotor core, each stator core consists of 4 stator poles, 2 The stator core forms 8 stator magnetic poles at the left and right ends of the magnetic bearing, which respectively form the magnetic poles in the positive and negative directions of the X and Y axes. Each stator magnetic pole is wound with an excitation coil. Outside the stator core is an external magnetic ring. Connected with the stator core, there is a permanent magnet in the middle of the two outer magnetic rings. Inside the stator core is the rotor core. There is a certain gap between the inner surface of the stator core and the outer surface of the rotor core to form an air gap. The inner magnetic ring is installed on the rotor. Inside the iron core, it connects the left and right rotor cores to form a magnetic path. The invention has the advantages of low power consumption, small size, light weight, convenient processing and manufacturing, etc., and can be used as a non-contact support for rotating parts in mechanical equipment such as motors and machine tools.

Description

A Low Power Consumption Permanent Magnet Bias Inner Rotor Radial Magnetic Bearing

Technical field

The invention relates to a non-contact magnetic suspension bearing, in particular to a low-power permanent magnet bias inner rotor radial magnetic bearing, which can be used as a non-contact support for rotating parts in mechanical equipment such as motors and machine tools.

Background technique

Magnetic suspension bearings are divided into pure electromagnetic bearings and hybrid magnetic suspension bearings with permanent magnetic bias and electromagnetic control. The former uses large current and consumes a lot of power, and the hybrid magnetic suspension bearings with permanent magnetic bias and electromagnetic control. The magnetic field generated by the permanent magnet bears the main load. Bearing capacity, the electromagnetic field provides auxiliary adjustment bearing capacity, so this kind of bearing can greatly reduce the control current and reduce the loss. However, some of the current permanent magnet bias inner rotor radial magnetic bearing structures are based on ordinary radial electromagnetic bearings, and permanent magnets are placed upward on the electromagnetic magnetic circuit, so that the magnetic flux generated by the control coil must pass through the permanent magnets. Due to the large reluctance of the permanent magnet, a large excitation current is required for the control coil to generate a certain electromagnetic flux. In addition, in some structures, the permanent magnet is directly connected to the stator laminated core, so that the permanent magnet magnetic circuit passes through the stator core. Excessive magnetomotive force will be lost during the process, thereby greatly weakening the attraction force of the permanent magnet to the rotor shaft; due to the above defects, the existing permanent magnet bias magnetic bearings have the disadvantages of large power consumption, large volume and heavy weight.

Contents of the invention

The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide a low power consumption permanent magnet bias inner rotor radial magnetic bearing with low power consumption, small volume, light weight and convenient processing and manufacturing.

One of the technical solutions of the present invention is: low power consumption permanent magnet bias inner rotor radial magnetic bearing, which is characterized in that it consists of an outer magnetic ring, a permanent magnet, a stator core, an excitation coil, an inner magnetic ring, and a rotor core Each stator core forms 4 magnetic poles, and 2 stator cores form 8 magnetic poles at the left and right ends of the magnetic bearing, which respectively form the magnetic poles in the positive and negative directions of the X and Y axes. Each stator magnetic pole is wound with an excitation coil. The outer magnetic ring is connected to the stator core. The permanent magnet is located in the middle of the two outer magnetic rings. The inside of the stator core is the rotor core. There is a certain gap between the inner surface of the stator core and the outer surface of the rotor core to form air gap, the inner magnetic ring is installed inside the rotor core, and connects the left and right ends of the rotor core to form a magnetic path.

The principle of the above scheme is: the permanent magnet provides the permanent magnetic bias magnetic field for the magnetic bearing, bears the radial force on the magnetic bearing, and the magnetic field generated by the excitation coil plays a regulating role, which is used to change the strength of the magnetic field at each pole and maintain The air gap between the stator and the rotor of the magnetic bearing is uniform, and the rotor is supported without contact. The permanent magnet magnetic circuit of the present invention is: the magnetic flux starts from the N pole of the permanent magnet, passes through the outer magnetic ring at one end, the stator core, the air gap, the rotor core, and the inner magnetic ring to the rotor core at the other end, the air gap, and the stator core , The outer magnetic ring returns to the S pole of the permanent magnet to form the main magnetic circuit of the magnetic suspension bearing, as shown in Figure 1. Taking the magnetic flux generated by the excitation coil current in the positive direction of the Y-axis at a certain end as an example, its path is: the magnetic pole in the positive direction of the Y-axis formed by the stator core, the air gap in the positive direction of the Y-axis to the rotor core, and then to the air gaps in the other three directions , the other three direction magnetic poles formed by the stator core, and returning to the Y-axis positive direction magnetic pole formed by the stator core form a closed loop, as shown in Figure 2. This not only ensures that the electric excitation magnetic circuit does not pass through the interior of the permanent magnet, reduces the reluctance of the electric excitation magnetic circuit, reduces the excitation current, but also ensures that the permanent magnet magnetic circuit does not directly pass through the laminated stator core, reducing the Loss of permanent magnet magnetomotive force.

The second technical solution of the present invention is: low power consumption permanent magnet bias inner rotor radial magnetic bearing, which is characterized in that it consists of an outer magnetic ring, a permanent magnet, a stator core, an excitation coil, an inner magnetic ring, and a rotor core Each stator core forms 4 magnetic poles, and 2 stator cores form 8 magnetic poles at the left and right ends of the magnetic bearing, which respectively form the magnetic poles in the positive and negative directions of the X and Y axes. Each stator magnetic pole is wound with an excitation coil. It is an outer magnetic ring, which is connected with the stator core. Inside the stator core is the rotor core. There is a certain gap between the inner surface of the stator core and the outer surface of the rotor core to form an air gap. The inner magnetic ring is installed on the rotor core. Inside, the permanent magnet is located in the middle of the two inner magnetic rings, and the two inner magnetic rings connect the left and right rotor cores to form a magnetic path.

The principle of the above scheme is: the permanent magnet provides the permanent magnetic bias magnetic field for the magnetic bearing, bears the radial force on the magnetic bearing, and the magnetic field generated by the excitation coil plays a regulating role, which is used to change the strength of the magnetic field at each pole and maintain The air gap between the stator and the rotor of the magnetic bearing is uniform, and the rotor is supported without contact. The permanent magnet magnetic circuit of the present invention is: the magnetic flux starts from the N pole of the permanent magnet, passes through the inner magnetic ring at one end, the rotor iron core, the air gap, the stator iron core, and the outer magnetic ring to the stator iron core at the other end, the air gap, and the rotor iron core , The inner magnetic ring at the other end returns to the S pole of the permanent magnet to form the main magnetic circuit of the magnetic suspension bearing, as shown in Figure 3. Taking the magnetic flux generated by the excitation coil current in the positive direction of the Y-axis at a certain end as an example, its path is: the magnetic pole in the positive direction of the Y-axis formed by the stator core, the air gap in the positive direction of the Y-axis to the rotor core, and then to the air gaps in the other three directions , the other three direction magnetic poles formed by the stator core, and returning to the Y-axis positive direction magnetic pole formed by the stator core form a closed loop, as shown in Figure 4. This not only ensures that the electric excitation magnetic circuit does not pass through the interior of the permanent magnet, reduces the reluctance of the electric excitation magnetic circuit, reduces the excitation current, but also ensures that the permanent magnet magnetic circuit does not directly pass through the laminated stator core, reducing the Loss of permanent magnet magnetomotive force.

Compared with the prior art, the present invention has the advantages that: because the present invention adopts the permanent magnet magnetic field as the bias magnetic field, compared with the traditional electromagnetic bearing, the bias current which accounts for the main component in the coil current is eliminated, and the copper loss and the copper loss of the winding are reduced. Power amplifier losses are controlled, so power consumption is low. At the same time, compared with the traditional electromagnetic bearing, the electromagnetic field produced by the permanent magnet electromagnetic bearing only changes in size and has no polarity change, which makes the magnetic bearing have very low iron loss, which further reduces power consumption. Compared with the existing permanent magnet bias magnetic bearing, the permanent magnet magnetic circuit of the low power consumption permanent magnet bias inner rotor radial magnetic bearing of the present invention is separated from the electric excitation magnetic circuit, because the reluctance of the electric excitation magnetic circuit Very low, a small excitation current can generate a large magnetic flux, thus saving power consumption; because of this structure, the permanent magnet magnetic circuit does not directly pass through the stator core of the laminations, so there is no permanent loss in the stator core. The magnetomotive force reduces the volume of the permanent magnet.

Another advantage of the present invention is: in a mechanical device, if the axial length is relatively short, in order to meet the requirements of the installation size, the excitation coils at both ends of the low power consumption permanent magnet bias inner rotor radial magnetic bearing can be independently control, so that the present invention can be used as two bearings to reduce the axial size; if the axial length of the equipment is longer, in order to better ensure the running stability of the equipment, the low power consumption permanent bearings can be used in pairs The radial magnetic bearing of the inner rotor is magnetically biased, and the distance between the two bearings is widened as much as possible. At this time, the excitation coils at the left and right ends of a bearing can be connected in series or parallel to save control circuits.

Description of drawings

Fig. 1 is an axial sectional view of an outer magnetic steel and an outer excitation coil low power consumption permanent magnet bias inner rotor radial magnetic bearing, one of the technical solutions of the present invention;

Fig. 2 is an axial end view of the outer magnetic steel and outer excitation coil low power consumption permanent magnet bias inner rotor radial magnetic bearing, one of the technical solutions of the present invention;

Fig. 3 is an axial cross-sectional view of the inner rotor radial magnetic bearing of the second technical solution of the present invention, the inner magnetic steel, the outer excitation coil, the low power consumption permanent magnet bias inner rotor;

Fig. 4 is an axial end view of the inner rotor radial magnetic bearing with inner magnetic steel and outer excitation coil with low power consumption permanent magnet bias of the second technical solution of the present invention.

Detailed ways

As shown in Figures 1 and 2, it is the outer magnetic steel of one of the technical solutions of the present invention, the outer magnetic coil low power consumption permanent magnet bias inner rotor radial magnetic bearing, which is the basic form of the present invention, and it consists of 2 outer Magnetic ring 1, 1 permanent magnet 2, 2 stator cores 3, 8 excitation coils 4, 1 inner magnetic ring 5, 2 rotor cores 6, 8 air gaps 7, each stator core 3 4 magnetic poles, 2 stator cores 3 form 8 magnetic poles at the left and right ends of the magnetic bearing, which respectively form the magnetic poles in the positive and negative directions of the X and Y axes. Each stator magnetic pole is wound with an excitation coil 4. The outside of the stator core 3 is an external magnetic conductor Ring 1, the outer magnetic ring 1 is connected with the stator core 3, the permanent magnet 2 is in the middle of the two outer magnetic rings 1, the inside of the stator core 3 is the rotor core 6, the inner surface of the stator core 3 and the outer surface of the rotor core 6 are left There is a certain gap to form an air gap 7, and the inner magnetic ring 5 is installed inside the rotor core 6, and connects the left and right rotor cores 6 to form a magnetic path. In this type of magnetic suspension bearing, the inner magnetic ring 5 can also be divided into two, and a permanent magnet is added between the two, so that the permanent magnet is connected in series with the permanent magnet 2 in the middle of the outer magnetic ring 1 .

As shown in Figures 3 and 4, the inner magnetic steel of the second technical solution of the present invention, the outer excitation coil low power consumption permanent magnet bias inner rotor radial magnetic bearing shaft, it consists of outer magnetic ring 1, permanent magnet 2, Stator core 3, excitation coil 4, inner magnetic ring 5, rotor core 6, and air gap 7. Each stator core 3 forms 4 magnetic poles, and 2 stator cores 3 form 8 magnetic poles at the left and right ends of the magnetic bearing. The magnetic poles in the positive and negative directions of the X and Y axes, each stator pole is wound with an excitation coil 4, and the outside of the stator core 3 is the outer magnetic ring 1, the outer magnetic ring 1 is connected with the stator core 3, and the inside of the stator core 3 is the rotor There is a certain gap between the inner surface of the stator core 3 and the outer surface of the rotor core 6 to form an air gap 7. The inner magnetic ring 5 is installed inside the rotor core 6. The permanent magnet 2 is located between the two inner magnetic rings 5. The inner magnetic ring 5 connects the left and right rotor cores 6 to form a magnetic path. This type of magnetic suspension bearing can also divide the outer magnetic ring 1 into two, and add a permanent magnet between the two, so that the permanent magnet is connected in series with the permanent magnet 2 in the middle of the inner magnetic ring 5 .

The used outer magnetic ring 1 and the inner magnetic ring 5 of each technical scheme of the present invention are made of materials with good magnetic properties, such as electrical pure iron, various carbon steels, cast iron, cast steel, alloy steel, 1J50 and 1J79 and other magnetic materials, etc. Stator core 3 and rotor core 6 can be formed by stamping and stacking magnetic materials such as electrical thin steel plates with good magnetic properties such as electrical pure iron, electrical silicon steel plates DR510, DR470, DW350, 1J50 and 1J79. The material of the permanent magnet 2 is a rare earth permanent magnet or a ferrite permanent magnet with good magnetic performance, and the permanent magnet 2 is an axial ring, which is magnetized along the axial direction. Exciting coil 4 is formed by dipping paint and drying after being wound with a good conductive electromagnetic wire.

Claims (10)

1. Low power consumption permanent magnet bias inner rotor radial magnetic bearing, characterized in that it consists of an outer magnetic ring (1), a permanent magnet (2), a stator core (3), an excitation coil (4), an inner magnetic Ring (5) and rotor core (6), each stator core (3) forms 4 magnetic poles, and 2 stator cores (3) form 8 magnetic poles at the left and right ends of the magnetic bearing, respectively forming the positive and negative directions of the X and Y axes Each stator pole is wound with an excitation coil (4), the outside of the stator core (3) is an outer magnetic ring (1), the outer magnetic ring (1) is connected with the stator core (3), and the permanent magnet (2 ) is located between the two outer magnetic rings (1), the inside of the stator core (3) is the rotor core (6), and there is a certain gap between the inner surface of the stator core (3) and the outer surface of the rotor core (6), forming an air gap (7), the inner magnetic ring (5) is installed inside the rotor core (6), and connects the left and right rotor cores (6) to form a magnetic path. 2. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 1, characterized in that: the inner magnetic ring (5) is divided into two, and a permanent magnet is added between the two A magnet is connected in series with the permanent magnet (2) in the middle of the outer magnetic ring (1). 3. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 1 or 2, characterized in that: said permanent magnet (2) is an axial ring, which is magnetized along the axial direction. 4. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 1 or 2, characterized in that: the permanent magnet (2) is made of rare earth permanent magnet material or ferrite permanent magnet material become. 5. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 1 or 2, characterized in that: the outer magnetic conduction ring (1) and the inner magnetic conduction ring (5) are all made of conduction Made of materials with good magnetic properties. 6. Low power consumption permanent magnet bias inner rotor radial magnetic bearing, characterized in that it consists of an outer magnetic ring (1), a permanent magnet (2), a stator core (3), an excitation coil (4), an inner magnetic Ring (5) and rotor core (6), each stator core (3) forms 4 magnetic poles, and 2 stator cores (3) form 8 magnetic poles at the left and right ends of the magnetic bearing, respectively forming the positive and negative directions of the X and Y axes Each stator pole is wound with an excitation coil (4), and the outside of the stator core (3) is an outer magnetic ring (1), and the outer magnetic ring (1) is connected with the stator core (3). 3) Inside is the rotor core (6), and there is a certain gap between the inner surface of the stator core (3) and the outer surface of the rotor core (6), forming an air gap (7), and the inner magnetic ring (5) is installed on the rotor core ( 6) Inside, the permanent magnet (2) is located between the two inner magnetic rings (5), and the inner magnetic rings (5) connect the left and right rotor cores (6) to form a magnetic path. 7. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 6, characterized in that: the outer magnetic ring (1) is divided into two, and a permanent magnet is added between the two magnet, make the permanent magnet and the permanent magnet (2) in the middle of the inner magnetic ring (5) in series. 8. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 6 or 7, characterized in that: said permanent magnet (2) is an axial ring, which is magnetized along the axial direction. 9. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 6 or 7, characterized in that: said permanent magnet (2) is made of rare earth permanent magnet material or ferrite permanent magnet material become. 10. The low power consumption permanent magnet bias inner rotor radial magnetic bearing according to claim 6 or 7, characterized in that: the outer magnetic conduction ring (1) and the inner magnetic conduction ring (5) are all made of conduction Made of materials with good magnetic properties.

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