Non-contact magnetic suspension linear moving platform

Abstract

The invention relates to the field of linear moving platforms, in particular to a non-contact magnetic suspension linear moving platform. According to the platform, a double-sheet magnetic bearing composed of a suspended object, magnetic conductive rings, a sheet stator, a bias winding coil and a control winding coil is adopted as a non-contact magnetic suspension system, the magnetic conductive rings are installed at the head end and the tail end of the suspended object, and a combined structure of the suspended object and the magnetic conductive rings is arranged on the inner side of a sleeve in the center of the sheet stator. The suspended object and the magnetic conductive ring combined structure are isolated from the outside through the sleeve; the whole non-contact magnetic suspension system is fixed in the shell and installed on the linear motor rotor through the shell, and the linear motor rotor does linear reciprocating motion along the linear motor stator to drive the magnetic suspension system to move together. According to the linear moving platform, the transportation condition that transported objects are required to be incapable of making contact with the transportation device due to special components or purposes is effectively met, and the problem that an existing linear moving platform cannot achieve non-contact transportation of the transported objects and the transportation device is solved.

Description

Technical Field

[0001] The invention relates to the field of linear motion platforms, in particular to a contactless magnetic suspension linear motion platform. Background Art

[0002] The linear motion platform is usually composed of a single axis or multiple axes, and the linear motion of the platform is achieved by controlling the movement of the motor. The rotary servo motor with ball screw transmission is currently the most widely used, but there are intermediate links such as couplings, screws, and bearings between the motor and the workbench, which increase the inertial mass of the positioning mechanism and affect the response speed. In addition, due to the elastic deformation, friction, contact gap and reverse gap generated by the intermediate links, the positioning feed motion is delayed and nonlinear errors are generated, which reduce the positioning accuracy. In addition, under the combined action of stress and temperature, the slender precision positioning screw will deform, affecting the positioning accuracy. The linear motion platform driven by a linear motor eliminates the intermediate transmission link, has a smaller motion error, greatly improves the dynamic response and accuracy, and has a higher moving speed. There is no contact between the guide link and the drive link, no friction loss, and higher efficiency. Based on the above advantages, the linear motion platform is widely used in packaging machinery, food processing equipment, printing equipment and other fields, realizing the precise movement and positioning of packaging materials, food or printing heads. However, when the transported objects are required not to come into contact with the transport device due to the presence of toxic, harmful, explosive or other dangerous goods or the transport environment requires to be sterile, pollution-free, friction-free, etc., the existing linear transport platform cannot meet the requirements. Summary of the invention

[0003] The purpose of the present invention is to provide a contactless magnetic levitation linear moving platform, which adopts a linear motor and a double-thin-film magnetic bearing structure to realize rapid contactless transportation of transported objects, effectively solving the problem that the existing linear moving platform cannot realize contactless transportation of transported objects and transport devices.

[0004] In order to achieve the above object, the technical solution of the present invention is: A contactless magnetic suspension linear moving platform, which adopts a double-sheet magnetic bearing composed of a suspended object, a magnetic ring, a thin-sheet stator, a bias winding coil, and a control winding coil as a contactless magnetic suspension system, wherein: magnetic rings are installed at both ends of the suspended object, and the combined structure of the suspended object and the magnetic ring is arranged on the inner side of a sleeve at the center of the thin-sheet stator, and the suspended object and the combined structure of the magnetic ring are isolated from the outside world by the sleeve; the thin-sheet stator is formed by integrally connecting stator teeth and a stator yoke, and four stator teeth are symmetrically arranged on the inner wall of the annular stator yoke as magnetic poles along the circumferential direction to form a four-pole salient pole structure The stator teeth on the two coaxially parallel thin-film stators correspond to each other one by one, and each stator tooth is wound with a bias winding coil and a control winding coil. The sleeve is passed through the axial center of the thin-film stator, but does not contact the suspended object and the thin-film stator. The entire double-film magnetic bearing is fixed in the outer shell and installed on the linear motor mover through the outer shell. The linear motor mover performs reciprocating linear motion along the linear motor stator. When the linear motor mover runs in a straight line, the double-film magnetic bearing stator and the linear motor mover move together. The suspended object moves with the double-film magnetic bearing stator due to the suspension force and does not contact the sleeve.

[0005] The non-contact magnetic suspension linear moving platform can be used with a solid or hollow suspended object. When the suspended object is hollow, other items to be transported can be placed inside the hollow object.

[0006] The contactless magnetic suspension linear moving platform has four stator teeth evenly distributed at 90° intervals, two stator teeth are placed horizontally, and the other two stator teeth are placed vertically, and the stator teeth at radially opposite positions are parallel or perpendicular to the horizontal plane.

[0007] The stator teeth of the contactless magnetic suspension linear moving platform are bar-shaped, and one end of the four stator teeth corresponding to the axis of the stator yoke is an arc surface matching the outer side of the sleeve, and a uniform air gap is formed between the arc surface of the stator teeth and the sleeve.

[0008] In the contactless magnetic suspension linear moving platform, the axial length of the thin-film stator is equal to the axial length of the magnetic conductive ring, and the spacing between the two magnetic conductive rings is equal to the spacing between the two thin-film stators.

[0009] In the contactless magnetic levitation linear moving platform, the four bias winding coils on each thin-film stator are wound on four stator teeth in sequence, the number of turns of the coils wound on each stator tooth is the same, the winding directions of the bias winding coils on adjacent stator teeth are opposite, and the four bias winding coils 4 are connected in series with each other; and the bias winding coils of the two thin-film stators are arranged in the same way.

[0010] In the contactless magnetic suspension linear moving platform, four control winding coils on each thin-film stator are wound on four stator teeth, the number of turns wound on each stator tooth is the same, and two control winding coils at radially opposite positions 180° apart are connected in series, but the two control winding coils connected in series are wound in opposite directions, so that the magnetic flux generated by one coil points to the center of the circle, and the magnetic flux generated by the other coil points away from the center of the circle; and the control winding coils of the two thin-film stators are arranged in the same manner.

[0011] The contactless magnetic suspension linear moving platform has two sets of control winding coils on each thin-film stator, which are x Direction control winding coil and y Direction control winding coil, the control winding coil in the horizontal position is x Direction control winding coil, the control winding coil in the vertical position is y Direction control winding coils, the control winding coils on different thin-film stators have the same number of turns and are independently controlled.

[0012] The contactless magnetic suspension linear moving platform, the bias winding coil and the control winding coil are both powered by direct current.

[0013] The design idea of ​​the present invention is: The present invention uses a linear motor to replace the traditional linear motion device (rotating motor + lead screw), eliminating the intermediate transmission link, greatly improving the system's dynamic response speed, control accuracy and operating efficiency. At the same time, when special transport objects are required not to contact the transport platform, a double-sheet magnetic bearing structure is proposed to achieve zero-contact transportation between the suspended object and the transport device. The contactless magnetic suspension linear mobile platform proposed by the present invention is particularly suitable for use in special fields such as high speed, vacuum, and ultra-clean where traditional contact-type linear transport platforms cannot meet the requirements.

[0014] Advantages and beneficial effects of the present invention: (1) The present invention adopts a linear motor to replace the traditional linear motion device (rotating motor + lead screw), eliminating the intermediate transmission link and greatly improving the dynamic response speed, control accuracy and operation efficiency of the system.

[0015] (2) The present invention adopts a double-sheet magnetic bearing structure and utilizes the principle of magnetic levitation to achieve five-degree-of-freedom suspension of the transported object, thereby achieving zero contact between the transported object and the transport platform, effectively meeting the transportation conditions where the transported object is required not to come into contact with the transport device due to its special composition or purpose, and solving the problem that the existing linear moving platform cannot achieve contactless transportation between the transported object and the transport device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a schematic diagram of the overall structure of a contactless magnetic suspension linear moving platform of the present invention.

[0017] Figure 2 It is a schematic diagram of the structure of the suspended object of the present invention.

[0018] Figure 3 It is a schematic diagram of the thin-film stator structure of the present invention.

[0019] Figure 4 It is a schematic structural diagram of the double-sheet magnetic bearing of the present invention.

[0020] Figure 5 It is a structural cross-sectional view of the double-sheet magnetic bearing of the present invention.

[0021] Figure 6 It is a schematic diagram of the magnetic flux path when the bias winding of the present invention is excited alone.

[0022] Figure 7 The present invention x Schematic diagram of the flux path when the directional control winding is excited alone.

[0023] Figure 8 This is a schematic diagram of the principle of generating axial suspension force of the present invention.

[0024] Reference numerals: 1. Suspended object; 11. Magnetic ring; 2. Sleeve; 3. Thin-film stator (31 stator teeth; 32 stator yoke); 4. Bias winding coil; 5. Control winding coil; 6. Housing; 7. Linear motor mover; 8. Linear motor stator. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features or features mentioned in the specific examples mentioned in the present invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Example

[0026] like Figure 1-Figure 8 As shown, the present invention proposes a contactless magnetic suspension linear moving platform, which mainly includes a suspended object 1 to be suspended and controlled, a sleeve 2, a thin stator 3, a bias winding coil 4, a control winding coil 5, a housing 6, a linear motor mover 7, a linear motor stator 8, a magnetic ring 11, etc. The specific structure is as follows: like Figure 1 , Figure 4 , Figure 5As shown, the double-sheet magnetic bearing is composed of the suspended object 1, the magnetic ring 11, the thin-sheet stator 3, the bias winding coil 4, and the control winding coil 5 as a contactless magnetic suspension system. The sleeve 2 is between the suspended object 1 and the thin-sheet stator 3, but does not contact the suspended object 1 and the thin-sheet stator 3. It can isolate the suspended object 1 from the outside world and protect the suspended object 1. The entire double-sheet magnetic bearing is fixed in the housing 6 and installed on the linear motor mover 7 through the housing 6. The linear motor mover 7 can make a reciprocating linear motion along the linear motor stator 8. When the linear motor mover 7 runs in a straight line, the thin-sheet stator 3 of the double-sheet magnetic bearing moves together with the linear motor mover 7. Because of the suspension force, the suspended object 1 moves with the thin-sheet stator 3 of the double-sheet magnetic bearing and does not contact the sleeve 2.

[0027] like Figure 2 As shown, magnetic rings 11 are installed at both ends of the suspended object 1. The suspended object 1 itself is not magnetic, but the magnetic rings 11 are installed on both sides of the suspended object 1, which can be used to generate suspension force, so that it is suspended in the sleeve 2 and can move linearly with the thin stator 3. The suspended object 1 can be solid or hollow. When the suspended object 1 is hollow, other items that need to be transported can be placed inside it.

[0028] like Figure 3 , Figure 6 , Figure 7 As shown, the thin-film stator 3 is formed by integrally connecting the stator teeth 31 and the stator yoke 32. The inner wall of the annular stator yoke 32 has four stator teeth 31 arranged symmetrically along the circumferential direction as magnetic poles, forming a four-pole salient pole structure. The four stator teeth 31 are evenly distributed at intervals of 90°, and the stator teeth 31 at the radially opposite position are parallel or perpendicular to the horizontal plane (two stator teeth 31 are placed horizontally, and the other two stator teeth 31 are placed vertically); the stator teeth 31 are strip-shaped, and the ends of the four stator teeth 31 corresponding to the axis of the stator yoke 32 are arc surfaces matching the outer side of the sleeve 2, and a uniform air gap is formed between the arc surfaces of the stator teeth 31 and the sleeve 2.

[0029] like Figure 3 , Figure 4 , Figure 5 As shown, the stator teeth 31 on the two coaxially parallel thin-film stators 3 correspond to each other, and each stator tooth 31 is wound with a bias winding coil 4 and a control winding coil 5, and the bias winding coil 4 is located outside the control winding coil 5; the sleeve 2 is inserted through the axial center of the thin-film stator 3, and the combined structure of the suspended object 1 and the magnetic conductive ring 11 is arranged inside the sleeve 2 at the center of the thin-film stator 3, and the combined structure of the suspended object 1 and the magnetic conductive ring 11 is isolated from the outside by the sleeve 2. The axial length of the thin-film stator 3 is equal to the axial length of the magnetic conductive ring 11, and the spacing between the two magnetic conductive rings 11 is equal to the spacing between the two thin-film stators 3.

[0030] The four bias winding coils 4 on each thin-film stator 3 are wound on four stator teeth 31 in sequence, and the number of turns of the coils wound on each stator tooth 31 is the same, but the winding directions of the bias winding coils 4 on adjacent stator teeth 31 are opposite, and the four bias winding coils 4 are connected in series with each other; and the bias winding coils 4 of the two thin-film stators 3 are configured identically. The four control winding coils 5 on each thin-film stator 3 are wound on four stator teeth 31, and the number of turns wound on each stator tooth 31 is the same, and the two control winding coils 5 at radially opposite positions 180° apart are connected in series with each other, but the winding directions of the two control winding coils connected in series on the stator teeth 21 are opposite, so that the magnetic flux generated by one control winding coil points to the center of the circle, and the magnetic flux generated by the other control winding coil points away from the center of the circle; and the control winding coils 5 of the two thin-film stators 3 are configured identically. There are two sets of control winding coils 5 on each thin-film stator 3, namely x Direction control winding coil and y Direction control winding coil, the control winding coil 5 in the horizontal position is x Direction control winding coil, the control winding coil 5 in the vertical position is y The direction control winding coils, the control winding coils 5 on different thin-film stators 3 have the same number of turns and are independently controlled. The bias winding coils 4 and the control winding coils 5 are both powered by direct current.

[0031] The working principle of the present invention is specifically as follows: like Figure 6 As shown, when the bias winding coil of the present invention is excited alone, the bias winding coil 4 generates a uniform bias flux under the four stator teeth 31. Φ b After the magnetic flux flows into the magnetic ring 11 from the horizontal stator teeth 31, it passes through the vertical stator teeth 31 and the stator yoke 32 to form a closed loop. The magnetic flux flowing through the stator teeth 31 at the radially opposite position has the same direction. x The magnetic flux of both directions points to the axis at the same time. y The magnetic flux in the direction is away from the axis at the same time.

[0032] like Figure 7 As shown, the present invention x When the direction control winding coil 5 is excited alone, x The direction control winding coil 5 generates a control magnetic flux under two horizontal stator teeth 31 Φ c , the magnetic flux flows from the stator tooth 31 in the positive x direction (horizontally on the right) into the magnetic ring, passes through the stator tooth 31 in the negative x direction (horizontally on the left) and the stator yoke 32 to form a closed loop. The magnetic fluxes flowing through these two stator teeth 31 have opposite directions. x The positive magnetic flux points to the axis. xNegative magnetic flux points away from the axis.

[0033] When the bias winding coil 4 is connected to x When the direction control winding coil 5 is excited at the same time, the control flux and the bias flux are superimposed on each other and flow through x The magnetic flux of stator tooth 31 in the positive direction is Φ b +Φ c , flows through x The magnetic flux of stator tooth 31 in the negative direction is Φ b -Φ c , so that the magnetic flux density under the stator tooth 31 in the positive x direction is greater than the magnetic flux density under the stator tooth 31 in the negative x direction, thereby generating x The positive direction of the suspension force. Similarly, if the reverse direction of the conduction x Direction control winding coil, can produce x Suspension force in negative direction. y The principle of generating the levitation force in the x direction is the same as that in the x direction. On the basis of the bias winding coil 4 being turned on, the current magnitude and direction of the control winding coil 5 in the x direction and the y direction can be flexibly adjusted to generate the levitation force in any direction, thereby achieving stable levitation of the suspended object 1.

[0034] like Figure 8 As shown in FIG. 1 , the principle of the axial suspension force of the present invention is as follows: when the linear motor mover 7 moves to the left along the linear motor stator 8, the linear motor mover 7 drives the thin-film stator 3 to move. Due to mechanical inertia, an axial displacement difference is generated between the thin-film stator 3 and the magnetic ring 11. At this time, under the action of the magnetic field, the magnetic ring 11 will be subjected to an axial restoring force F Z , the axial restoring force F Z The direction always tends to align the thin-film stator 3 with the magnetic ring 11, that is, the combined structure of the suspended object 1 and the magnetic ring 11 moves in the same direction as the linear moving platform, thereby making the suspended object 1 and the thin-film stator 3 move in the same direction.

[0035] The implementation results show that the entire contactless magnetic suspension system of the present invention is fixed in the housing and installed on the linear motor mover through the housing. The linear motor mover moves back and forth along the linear motor stator, driving the magnetic suspension system to move together. The combination structure of the linear motor and the double-sheet magnetic bearing realizes the zero-contact rapid transportation of the suspended object and the transport device, effectively meeting the transportation conditions where the transported object is required not to contact the transport device due to special composition or use, and solves the problem that the existing linear moving platform cannot realize the contactless transportation of the transported object and the transport device.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A contactless magnetic suspension linear moving platform, characterized in that: The platform adopts a double-sheet magnetic bearing composed of a suspended object, a magnetic ring, a thin-sheet stator, a bias winding coil, and a control winding coil as a contactless magnetic suspension system, wherein: magnetic rings are installed at both ends of the suspended object, and the combined structure of the suspended object and the magnetic ring is arranged on the inner side of a sleeve at the center of the thin-sheet stator, and the suspended object and the combined structure of the magnetic ring are isolated from the outside world by the sleeve; the thin-sheet stator is formed by integrally connecting the stator teeth and the stator yoke, and the inner wall of the annular stator yoke has four stator teeth symmetrically arranged along the circumferential direction as magnetic poles to form a four-pole salient pole structure; two coaxial parallel The stator teeth on the thin-film stator are arranged to correspond one to one, and each stator tooth is wound with a bias winding coil and a control winding coil. The sleeve is passed through the axial center of the thin-film stator, but does not contact the suspended object and the thin-film stator; the entire double-film magnetic bearing is fixed in the outer shell and installed on the linear motor mover through the outer shell. The linear motor mover performs reciprocating linear motion along the linear motor stator. When the linear motor mover runs in a straight line, the double-film magnetic bearing stator and the linear motor mover move together. Due to the suspension force, the suspended object moves with the double-film magnetic bearing stator and does not contact the sleeve.

2. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The suspended object is solid or hollow; when the suspended object is hollow, other items that need to be transported are placed inside it.

3. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The four stator teeth are evenly distributed at intervals of 90 degrees, two stator teeth are placed horizontally, and the other two stator teeth are placed vertically, and the stator teeth at radially opposite positions are parallel or perpendicular to the horizontal plane.

4. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The stator teeth are bar-shaped, and one end of the four stator teeth corresponding to the axis of the stator yoke is an arc surface matching the outer side of the sleeve, and a uniform air gap is formed between the arc surface of the stator teeth and the sleeve.

5. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The axial length of the thin-film stator is equal to the axial length of the magnetic conductive ring, and the distance between the two magnetic conductive rings is equal to the distance between the two thin-film stators.

6. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The four bias winding coils on each thin-film stator are wound around four stator teeth in sequence, the number of turns of the coils wound around each stator tooth is the same, the winding directions of the bias winding coils on adjacent stator teeth are opposite, and the four bias winding coils are connected in series with each other; and the bias winding coils of the two thin-film stators are arranged in the same way.

7. The contactless magnetic suspension linear motion platform according to claim 1, characterized in that: The four control winding coils on each thin-film stator are wound around four stator teeth, and the number of turns wound on each stator tooth is the same. The two control winding coils at radially opposite positions 180° apart are connected in series with each other, but the two control winding coils in series are wound in opposite directions, so that the magnetic flux generated by one coil points to the center of the circle, and the magnetic flux generated by the other coil points away from the center of the circle; and the control winding coils of the two thin-film stators are set the same.

8. The contactless magnetic suspension linear motion platform according to claim 7, characterized in that: Each thin-film stator has two sets of control winding coils, namely x Direction control winding coil and y Direction control winding coil, the control winding coil in the horizontal position is x Direction control winding coil, the control winding coil in the vertical position is y Direction control winding coils, the control winding coils on different thin-film stators have the same number of turns and are independently controlled.

9. The contactless magnetic suspension linear moving platform according to claim 1, characterized in that: The bias winding coil and the control winding coil are both powered by direct current.

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