CN111173838B - Radial uncoupled three-degree-of-freedom direct current hybrid magnetic bearing - Google Patents

Abstract

The invention discloses a radial non-coupling three-degree-of-freedom DC hybrid magnetic bearing, which includes a radial stator, an axial stator and a rotor located in the inner ring of the stator. The radial stator is composed of a left radial iron core and a right radial iron core; The right radial core has two suspension teeth evenly distributed along the inner circumference; the outer sides of the left and right stator cores are respectively left and right radially magnetized permanent magnet rings; the suspension teeth are wound with centralized radial control windings; the axial stator is driven by the left It consists of an axial iron core and a right axial iron core; on both sides of the left radial iron core and the right radial iron core, and near the inner side of the axial stator, an axial control winding connected in series is arranged; the rotor includes a cylindrical rotor iron core and a rotating shaft. In the present invention, the static bias magnetic flux is provided by the action of the permanent magnetic ring, and the radial control magnetic flux generated by the radial control winding energization adjusts the corresponding bias flux; the hybrid magnetic bearing with this structure is independently designed for suspension in the X and Y directions, realizing suspension The force is uncoupled in the X-Y direction, and the control is simple.

Description

Radial uncoupled three-degree-of-freedom DC hybrid magnetic bearing

technical field

The invention relates to a non-mechanical contact magnetic bearing, in particular to a radial non-coupling three-degree-of-freedom DC hybrid magnetic bearing, which can be used as a non-contact suspension support for high-speed transmission components such as flywheel systems, machine tool electric spindles, and centrifuges.

Background technique

The magnetic bearing is a new type of high-performance bearing that uses the electromagnetic force between the stator and the rotor to suspend the rotor in space, so that there is no mechanical contact between the stator and the rotor. At present, magnetic bearings are divided into the following three types according to the way the magnetic force is provided: (1) Active magnetic bearings, the bias magnetic field is generated by the bias current, and the control flux generated by the control current and the bias flux are superimposed on each other, thereby generating a controllable The levitation force of this kind of magnetic bearing is relatively large in size, weight and power consumption; (2) passive magnetic bearing, the levitation force is completely provided by permanent magnets, the required controller is simple, the levitation power consumption is small, but the stiffness and damping are both Smaller, generally used to support objects in only one direction or reduce the load on traditional bearings; (3) hybrid magnetic bearings, which use permanent magnetic materials instead of electromagnets in active magnetic bearings to generate bias magnetic fields, The control current only provides the control magnetic flux to balance the load or disturbance, which greatly reduces the power loss of the magnetic bearing, reduces the volume and weight of the magnetic bearing, and improves the carrying capacity.

The common feature of the existing hybrid magnetic bearing structure is that all the suspension teeth in the radial direction are in the same plane. The radial suspension teeth wind the control winding to generate radial control magnetic flux, which interacts with the corresponding bias magnetic flux to generate radial to the suspension force. The radial two-degree-of-freedom suspension of the hybrid magnetic bearing of this structure is realized in a single piece, resulting in the coupling of the suspension force in the XY direction, and the control is complicated.

Contents of the invention

The purpose of the present invention is to propose a radial non-coupling three-degree-of-freedom DC hybrid magnetic bearing with simplified control, compact structure, and convenient manufacture and assembly. It adopts a double-piece structure, and the suspension in the X-Y directions is controlled by an independent stator core. Realized, the suspension force has no coupling in the X-Y direction, and the control is simple.

The present invention is realized through the following technical solutions:

A radial uncoupled three-degree-of-freedom DC hybrid magnetic bearing, comprising a radial stator, an axial stator, and a rotor located on the inner ring of the stator, the radial stator includes a left radial iron core and a right radial iron core, and the rotor includes The rotor core and the rotating shaft; the left radial core is along the inner circumference and is symmetrically distributed with two floating teeth in the direction of the +x axis and the -x axis; the right radial core is along the inner circumference and is in the direction of the +y axis and the -y axis Two floating teeth are evenly distributed in the aligned position; the four floating teeth are all zigzag structures, and the end surface close to the rotor core matches the circumferential surface of the rotor core, and its axial width is the same as that of the rotor core and the position is positive Yes, a radial air gap with the same air gap length is formed between the suspension teeth and the rotor core; centralized radial control windings are wound on the suspension teeth; left and right Radial magnetized permanent magnet ring;

The axial stator includes a left axial iron core and a right axial iron core. The inner diameters of the left and right axial iron cores are the same as the outer diameters of the left and right radially magnetized permanent magnet rings, and they are sleeved on the left and right radially magnetized rings respectively. On the magnetized permanent magnet ring; the left and right radial cores are relatively outside and close to the inner ring walls of the left and right axial cores. A pair of axial control windings are arranged in series. , Right axial core and left and right radial core.

Further, the left and right axial cores are arranged opposite to each other, and a closed surface is provided on a side relatively far away from the left and right axial cores, and the closed surfaces on the left and right axial cores extend inwardly with the center as the center to form a cylindrical ring, The inner diameter of the cylindrical ring is slightly larger than the outer diameter of the rotating shaft and extends close to the rotor core, forming left and right axial air gaps with the left and right sides of the rotor core respectively.

Further, the width of the left axial air gap is the same as that of the right axial air gap.

Further, the left and right radial cores, the left and right axial cores and the rotor core are all made of magnetically permeable materials;

Further, the left and right radially magnetized permanent magnet rings are made of rare earth permanent magnet materials.

Beneficial effect:

1. In the present invention, the static bias magnetic flux is provided by the action of the permanent magnetic ring, and the radial control magnetic flux generated by the radial control winding energization adjusts the corresponding bias flux; Chip structure, and the suspension teeth are designed as a zigzag structure, so that the suspension teeth in the X and Y directions are coplanar with the rotor core, so that the suspension force is not coupled in the X-Y direction, and the control is simple.

2. The present invention adds a pair of axial stators, so that the hybrid magnetic bearing of the present invention produces three degrees of freedom.

Description of drawings

Fig. 1 is a structural diagram of a radial uncoupled three-degree-of-freedom DC hybrid magnetic bearing of the present invention;

Fig. 2 is a structure diagram of the left and right axial cores of the present invention;

Fig. 3 is a suspension magnetic flux diagram of the radial uncoupled three-degree-of-freedom DC hybrid magnetic bearing of the present invention.

1-left radial core, 101-suspension tooth A, 102-suspension tooth B, 2-right radial core, 201-suspension tooth C, 202-suspension tooth D, 3-left axial core, 301-left closed surface , 302-left cylindrical ring, 4-right axial core, 401-right closed surface, 402-right cylindrical ring, 5-left radial magnetization permanent magnet ring, 6-right radial magnetization permanent magnet ring, 7-left shaft Direction control winding, 8-radial control winding, 9-right axial control winding, 10-rotor core, 11-rotating shaft, 12-static bias flux, 13-right axial air gap, 14-radial air gap , 15-axial control flux, 16-left axial air gap.

Detailed ways

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

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and therefore should not be construed as limitations on the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

The specific structure is shown in FIG. 1 . The radial non-coupling three-degree-of-freedom DC hybrid magnetic bearing disclosed in the present invention includes a radial stator, an axial stator and a rotor located in the inner ring of the stator.

The radial stator includes a left radial core 1 and a right radial core 2. The left radial core 1 and the right radial core 2 are ring structures with the same size. The left radial core 1 is evenly distributed with two floating teeth along the inner circumference. Denoted as suspension teeth A 101 and suspension teeth B 102 respectively, the suspension teeth A 101 and suspension teeth B 102 are respectively aligned with the +x-axis and -x-axis directions. The right radial core 2 is evenly distributed with two suspension teeth along the inner circumference, respectively denoted as suspension teeth C 201 and suspension teeth D 202 , and the suspension teeth C 201 and suspension teeth D 202 are respectively aligned with the +y axis and the -y axis. Referring to attached drawing 1, that is, suspension teeth A and suspension teeth B are located at both ends of the diameter of the inner circle of the left radial core 1, suspension teeth C and suspension teeth D are located at both ends of the diameter of the inner circle of the right radial core 2, and the suspension The connection line between tooth A and suspension tooth B is perpendicular to the connection line between suspension tooth C and suspension tooth D.

The rotor includes a cylindrical rotor core 10 and a rotating shaft 11 , and the rotating shaft 11 runs through the rotor core 10 .

Left and right radially magnetized permanent magnet rings (5, 6) are respectively arranged on the outer sides of the left and right radial iron cores (1, 2). The four suspension teeth A101 , suspension teeth B102 , suspension teeth C201 , and suspension teeth D202 are all zigzagging structures, see Figure 3 . Suspension teeth A101, suspension teeth B102, suspension teeth C201, suspension teeth D202 coincide with the front projections of the left and right edges of the vertical part of the rotor core 10, that is, the end of the four suspension teeth close to the rotor core 10 has the same axial width as the rotor core 10 and the position is positive. Yes, and the end face of the four floating teeth close to the rotor core 10 is an arc-shaped end face, and its arc matches the arc of the circumferential surface of the rotor core 10 . A radial air gap 14 with equal air gap length is formed between the four floating teeth and the rotor core 10 . Centralized radial control windings 8 are wound on the suspension teeth A101 , suspension teeth B102 , suspension teeth C201 and suspension teeth D202 .

The axial stator includes a left axial iron core 3 and a right axial iron core 4. The left axial iron core 3 and the right axial iron core 4 are ring structures with the same outer diameter opposite to each other. The left side of the left axial iron core 3 is provided with a left closed On the surface 301 , the right side of the axial core 4 is provided with a right closed surface 401 . In this way, the left axial core 3 and the right axial core 4 are combined to form a cylindrical shape, and the closed surfaces on the left and right axial cores (3, 4) extend inward with the center of the circle as the center to form a cylindrical ring, see 2, the left closed surface 301 of the left axial core 3 extends from the center point to the side close to the right axial core 4, forming a left cylindrical ring 302, and the right closed surface 401 of the right axial core 4 takes the center point as The origin extends toward the side close to the left axial core 3 to form a right cylindrical ring 402 . The inner diameters of the left cylindrical ring 302 and the right cylindrical ring 402 are slightly larger than the outer diameter of the rotating shaft 11 . The left cylindrical ring 302 is close to the left side of the rotor core 10, forming a left axial air gap 16 with the left side of the rotor core 10, and the right cylindrical ring 402 is close to the right side of the rotor core 10, and is connected with the rotor core 10 A right axial air gap 13 is formed between the right sides of the The left axial air gap 16 has the same width as the right axial air gap 13 .

The inner diameters of the left and right axial iron cores (3, 4) are the same as the outer diameters of the left and right radially magnetized permanent magnet rings (5, 6), so that the left axial iron cores 3 are set on the left radially magnetized permanent magnet rings 5, the right axial iron core 4 is sleeved on the right radial magnetized permanent magnet ring 6. Because the left and right axial cores (3, 4) are provided with a closed surface, the left and right radially magnetized permanent magnet rings (5, 6) and the left and right radial cores (1, 2) ) and the rotor core 10 are arranged in the left and right axial cores (3, 4), see Figure 2.

A left axial control winding 7 is provided on the left side of the left radial core 1 and close to the left closed surface 301 of the left axial core 3 , and a left axial control winding 7 is provided on the right radial core 2 and close to the right closed surface 401 of the right axial core 4 The right axial control winding 9, the left axial control winding 7 and the right axial control winding 9 are connected in series and their outer diameters are equal to the inner diameters of the rings of the left and right axial cores (3, 4).

The static bias flux 12 generated by the right radially magnetized permanent magnet ring 6 starts from the N pole, passes through the right axial core 4, the right axial air gap 13, the rotor core 10, the radial air gap 14, and the right axial core The suspension teeth C201 and D202 on the 2 return to the S pole. The principle of the bias magnetic flux generated by the permanent magnet ring 5 on the left axial core 1 is the same.

The radial control magnetic flux generated by the radial control winding 8 on the left radial core 1 passes through the yoke of the left radial core 1 , the suspended teeth A101 , B102 and the rotor core 10 form a closed loop. The principle of the radial control magnetic flux generated on the right radial core 2 is the same.

The axial control magnetic flux 15 generated by the left and right axial control windings (7, 9) forms a closed path through the left and right axial iron cores (3, 4) and the left and right axial air gaps (16, 13).

Suspension principle: The static bias magnetic flux 12 interacts with the radial control flux and the axial control flux 15 respectively, so that the air gap magnetic field on the same side as the radial eccentric direction of the rotor is superimposed and weakened, while the air gap magnetic field in the opposite direction is superimposed Reinforcement, which produces a force on the rotor opposite to the direction of rotor deflection, pulling the rotor back to its radially balanced position.

The technical means disclosed in the solutions of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications are also considered as the protection scope of the present invention.

Claims (1)

1. A radial uncoupled three-degree-of-freedom DC hybrid magnetic bearing, comprising a radial stator, an axial stator and a rotor positioned at the inner ring of the stator, characterized in that, The radial stator includes a left radial iron core and a right radial iron core, and the rotor includes a rotor iron core and a rotating shaft; two left radial iron cores are evenly distributed along the inner circumference and symmetrical to the +x axis and the -x axis Suspension teeth; two suspension teeth are evenly distributed along the inner circumference of the right radial core and symmetrical to the +y-axis and -y-axis directions; the four suspension teeth are all zigzag structures, which are close to one end surface of the rotor core and the The circumferential surface of the rotor core is matched, and its axial width is the same as that of the rotor core and the position is directly opposite. A radial air gap with the same air gap length is formed between the suspension teeth and the rotor core; the suspension teeth are wound with centralized Radial control windings; left and right radially magnetized permanent magnet rings are respectively arranged on the outer sides of the left and right radial cores; The axial stator includes a left axial iron core and a right axial iron core. The inner diameters of the left and right axial iron cores are the same as the outer diameters of the left and right radially magnetized permanent magnet rings, and they are sleeved on the left and right radially magnetized rings respectively. On the magnetized permanent magnet ring; the left and right radial cores are relatively outside and close to the inner ring walls of the left and right axial cores. A pair of axial control windings are arranged in series. , the right axial core and the left and right radial cores; The left and right axial cores are arranged opposite to each other, and a closed surface is provided on one side relatively far away from the left and right axial cores. The closed surfaces on the left and right axial cores all extend inwards with the center as the center of a circle to form a cylindrical ring. The inner diameter of the ring is slightly larger than the outer diameter of the rotating shaft and it extends to a place close to the rotor core, forming left and right axial air gaps with the left and right sides of the rotor core respectively; The width of the left axial air gap is the same as that of the right axial air gap; The left and right radial cores, the left and right axial cores and the rotor core are all made of magnetically permeable materials; The left and right radially magnetized permanent magnet rings are made of rare earth permanent magnet materials.

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