KR100277961B1 - Magnetic bearing module with noise protection wiring - Google Patents

Abstract

The disclosed high precision equipment relates to a magnetic bearing module having noise preventing wiring. The present invention provides a magnetic bearing module comprising a body in which an electromagnet generating magnetic force is built, a guard embedded in the vicinity of the electromagnet of the body, and a sensor part embedded in the guard to measure displacement thereof. The sensor wire for wiring the sensor unit, the guard wire wired from the guard, and the ground wire wired from the body are sequentially composed of three coaxial axes so as to surround each wire in a coaxial manner so as not to be influenced by other conductors. . The triaxial axis line is configured such that the guard line surrounds the sensor line, the ground line re-wraps the guard line, and the body is provided with a wiring hole such that the triaxial axis line is drawn out to one side thereof. Therefore, the parasitic capacitance is prevented from being generated between the ground and the sensor wire, and the external noise flowing into the sensor wire is prevented to measure the exact displacement of the table and to actively act on the external load or disturbance. do.

Description

Magnetic bearing module with noise protection wiring

The present invention relates to ultra-precision equipment, and more particularly to a magnetic bearing module having a noise preventing wiring.

Recently, the demand for various ultra-precision machines is increasing due to the rapid development of the semiconductor industry and the optical industry. In particular, the development of linear motion units, which determine the precision of semiconductor equipment, ultra-precision processing equipment, and measuring equipment, is urgently needed, leading to an important time for research and development and securing of basic technology.

In the case of the sensor device inspection equipment currently in use, the transfer table and the microscope must be manually adjusted to inspect the device by the manual method. This results in a decrease in the work efficiency as well as in the accuracy of the inspection. In addition, the high precision equipment such as semiconductor equipment and optical measuring equipment has a linear motion table as a key element, which determines the accuracy of the entire system. Recently, due to the remarkable development of ultra-precision technology, many researches on linear motion devices with high precision have been conducted, and the demand is also increasing.

Ball bearings and roller bearings are commonly used as support bearings of conventional linear motion systems. However, there are limitations in making the position accuracy extremely accurate due to the up and down swing and frictional forces caused by the elastic deformation and non-uniformity of the ball and roller. have. Therefore, in order to exhibit a high precision of 1 m or less, the fluid bearing that supports the table using lubricating fluid such as oil or air is applied so that the table and the guide surface are in contact with each other. In particular, in the case of tables supported by air bearings, the rigidity is somewhat small, but due to the low viscosity of the air itself, it shows very small frictional loss characteristics and is widely used to obtain higher precision than other methods.

However, in order to use air or oil as a lubricating fluid of a bearing, a compressor for raising the fluid to a constant pressure and a filter for removing impurities from the fluid are essential, which is expensive and increases the overall configuration of the transport system. As it is difficult to maintain and manage, noise caused by the rotation of the compressor affects the system, and special efforts are required to increase the feeding accuracy.

In addition, the fluid bearing is a so-called manual system, which is difficult to change its characteristics upon operation once the supply pressure, orifice diameter, lubrication gap, etc., which determine its characteristics, is difficult to actively control as the user intends. Some semiconductor manufacturing equipment or special processing equipment such as ion beam processing requires a vacuum environment, and when a fluid is used as the guide surface lubricant of the linear motion system, there are various problems that the application of the system is difficult in such a special environment.

Therefore, in recent years, in order to solve the above-mentioned shortcomings, the magnetic bearing module for linear motion table, which can obtain precise linear motion with little driving force due to complete friction without the table being injured by magnetic force, is widely used. to be. In addition, the magnetic bearing module for the linear motion table is a very important factor to accurately measure the displacement between the table and the guide to precisely control the gap.

However, the conventional magnetic bearing module for linear motion table as described above twists the wires such as sensor wires and guard wires embedded therein and shields them so that noise is easily introduced into the sensor wires and guard wires from the outside. . When noise is introduced from the outside, the capacitance corresponding to the distance between the table and the guide is changed by the noise, and the capacitance value to be detected through the sensor line and the guard line is changed, and thus, the exact displacement between the guide and the table cannot be measured. there was.

In addition, when the sensor wire and the guard wire are wired to each other, the inductance value is increased than when each wire is not twisted, so that when detecting displacement at a high speed, that is, when detecting a signal at a high frequency, the impedance value of the minute change in frequency Is too large to obtain a precise signal.

In addition, when the displacement of the table is measured through the sensor, an error occurs in the displacement of the table due to external noise introduced into the sensor and / or the guard wire, thereby causing another problem in that the magnetic bearing module malfunctions.

Accordingly, an object of the present invention devised to solve the above problems is to provide a magnetic bearing module for a linear motion table that can obtain a precise linear motion with a small driving force due to the complete frictionless in the state that the table is magnetically levitated In application, the present invention provides a magnetic bearing module having noise preventing wiring for preventing the external noise from flowing into the sensor wire and the guard wire so as to measure accurate displacement of the table.

Another object of the present invention is to prevent noise from externally flowing into the sensor wire and the guard wire, thereby preventing the error of the measured displacement and the malfunction of the table, thereby preventing the table from actively acting on external loads or disturbances. It is to provide a magnetic bearing module having a wiring.

1A and 1B are exploded perspective views showing a preferred embodiment of a magnetic bearing module having a noise preventing wiring according to the present invention;

2 is a perspective view showing a completed state of the magnetic bearing module having a noise preventing wiring according to the present invention;

Figure 3 is an overall perspective view showing the state of use of the linear motion table equipped with a magnetic bearing module having a noise preventing wiring according to the present invention,

4 is a perspective view of main parts of the linear motion table according to the present invention.

Explanation of symbols on the main parts of the drawings

25: Guide 30: Table

40: magnetic bearing module 40a: body

40b: depression 40c, 40d: wiring man

41: electromagnet 42: displacement sensor

42a: sensor portion 42b: guard

43: three coaxial line 43a: sensor line

43b: guard wire 43c: ground wire

44 terminal 45 electromagnet wiring

46: sensor wiring

A magnetic bearing module having a noise preventing wiring according to the present invention for achieving the above object includes a body in which an electromagnet generating magnetic force is embedded, a guard embedded in the vicinity of the electromagnet of the body, and the guard. In the magnetic bearing module comprising a sensor unit for measuring the displacement of the built-in magnetic bearing module, the guard wires wired from the guard and the ground wires wired from the body wrap each wire so as to be mutually insulated coaxially with the ground wires Characterized in that the triaxial axis to be located on the outside.

In addition, the triaxial axis may be configured such that the guard wire surrounds the sensor wire and the ground wire surrounds the guard wire. Alternatively, the sensor line may surround the guard line, and the ground line may be configured to surround the sensor line.

The body is provided with a respective electromagnet wiring hole and sensor wiring hole so that the triaxial axis is drawn out to one side thereof.

The triaxial axis is composed of electromagnet wiring and sensor wiring which are separated / formed so as not to have mutual interference in the magnetic bearing module and are drawn out to the respective electromagnet wiring and sensor wiring.

Therefore, by preventing the external noise flowing into the sensor line to measure the accurate displacement of the table and to actively act on the table against external load or disturbance.

Hereinafter, a preferred embodiment of a magnetic bearing module having a noise preventing wiring according to the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B are exploded perspective views showing a preferred embodiment of a magnetic bearing module having noise preventing wiring according to the present invention, and FIG. 2 is a perspective view showing a completed state of the magnetic bearing module having noise preventing wiring according to the present invention. to be.

According to FIG. 1A, the magnetic bearing module 40 according to the present invention includes a body 40a, an electromagnet 41 embedded in the body 40a to generate a magnetic force, and a displacement sensor 42 measuring the displacement thereof. The body 40a is formed with three recesses 40b on three surfaces such that the electromagnet 41 and the displacement sensor 42 are mounted in pairs, respectively, and the wiring inside the body 40a is Each of the electromagnet wiring holes 40c and the sensor wiring holes 40d is provided on one side thereof so as to be drawn out to the outside.

According to FIG. 1B, the displacement sensor 42 is provided with a guard 42b which is embedded in the body 40a and wraps so that the upper side of the sensor part 42a is opened. Here, the sensor line for wiring of the sensor part 42a is provided. 43a), the guard wire 43b wired from the guard 42b, and the ground wire 43c wired from the said body 40a are comprised by the triaxial axis 43 which surrounds each wiring. In addition, the triaxial line 43 is configured such that the guard line 43b surrounds the sensor line 43a, and the ground line 43c surrounds the guard line 43b, so that noise flowing from the outside is grounded. Blocked by 43c prevents the inflow of noise into the sensor wire 43a and the guard wire 43a. Here, the lines 43a, 43b, 43c are treated to be insulated from each other. For example, a guard wire consists of an insulating layer of the part which contact | connects a sensor wire, and the conductor layer which wraps an insulating layer. The ground line is formed by sequentially concentrically stacking an inner insulation layer and a conductor layer outer insulation layer. As the insulating layer material, various materials such as polyethylene may be applied.

Alternatively, the sensor wire may be configured to surround the guard wire and the ground wire may surround the sensor wire so as to be insulated from each other.

2, the electromagnet 41 and the displacement sensor 42 are embedded in the depression 40b of the body 40a, vacuum-impregnated with epoxy, and then processed / formed, and the three-hole wiring 40c is used. The magnetic bearing module 40 having the noise preventing wiring according to the present invention is completed by drawing out the axis 43 and forming the terminal 44 at its end. The triaxial shaft 43 is separated / formed so that there is no mutual interference in the magnetic bearing module 40, and the electromagnet wiring 45 and the sensor drawn out to the respective electromagnet wiring holes 40c and the sensor wiring holes 40d. It consists of the wiring 46.

3 is an overall perspective view showing the state of use of the linear motion table equipped with a magnetic bearing module having a noise preventing wiring according to the present invention, Figure 4 is a perspective view of the main portion of the linear motion table according to the present invention.

According to FIG. 3, the linear guide 11 is formed at both sides of the upper end of the bed 10. The Y-axis table 20 is mounted on the bed 10 and supported by the linear guide 11 and driven by the linear motor 12 and the linear scale 13 provided under the bed 10 to be transferred in the Y-axis direction. The X-axis table 30 uses the Y-axis table 20 as a bed, is supported by a plurality of magnetic bearing modules 40, and is driven by the linear motor 21 and the linear scale 22 to be transferred in the X-axis direction. Preferably, the linear motors 12 and 21 apply a brushless DC (BLDC) motor.

The main controller 50 controls the driving of the linear motors 12 and 21 and the driving of the magnetic bearing module 40, and includes a linear motor driving servo amplifier 51 and a computer (not shown). . The servo amplifier 51 for driving the linear motors 12 and 21 is composed of a BLDC servo amplifier and a power supply device for the servo amplifier. The servo amplifier 51 receives signals from the Hall sensors of the linear motors 12 and 21 to locate the permanent magnets and serves to flow three-phase currents through the heads of the linear motors 12 and 21. .

According to FIG. 4, the Y-axis table 20 fixes the guide plate 23 to the upper and side surfaces of both sides thereof with bolts 24. Laminated guides 25 are provided on the top and bottom and sidewalls of the guide plate 23, respectively. In addition, a linear scale head and a linear motor head (not shown) are provided below the rectangular X-axis table 30. The magnetic bearing module 40 is fixed to the four corners of the X-axis table 30. The plurality of magnetic bearing modules 40 is composed of an electromagnet 41 for generating a magnetic force against the laminated guide 25 of the Y-axis table 20 and a displacement sensor 42 for measuring the displacement thereof. . Therefore, the X-axis table 30 is conveyed with the laminated guide 25 inside the vertical and horizontal guide plates 23 on the Y-axis table 20 as the guide surface, and the driving thereof is located at the center. Is made by a linear motor 21 and the conveying position is measured by a linear scale 22.

Referring to the operation of the present invention configured in this way in more detail as follows.

According to Figure 1a, the magnetic bearing module 40 of the present invention is equipped with one electromagnet 41 and the displacement sensor 42 in each of the upper, lower and side to form a magnetic bearing module 40, these A total of 12 electromagnets 41 and a displacement sensor 42 are used as a system for supporting the table 30 up, down, left, and right. In addition, the gap between the magnetic pole 41 of the magnetic bearing module 40 and the guide 25 is set to about 0.3 mm in consideration of the displacement sensitivity of the magnetic force.

Therefore, the linear motion table according to the present invention is composed of a Y axis supported by the linear guide 11 and an X axis supported by the magnetic bearing module 40, both of which are driven by the linear motors 12 and 21. . The linear motors 12 and 21 receive the position signals by the linear scales 13 and 22 and control them using a DSP board of a computer (not shown). According to FIG. 3, the Y-axis table 20 is driven by the linear motor 12 and the linear scale 13 provided below the Y-axis direction while being supported by the linear guides 11 on both sides of the bed 10. Is transferred to. Here, the BLDC servo amplifier 51 controls the linear motor 12 under the control of a computer (not shown) in order to drive the linear motor 12, but the signal from the Hall sensor of the linear motor 12 It receives the position of the permanent magnet and transfers the three-phase current to the linear motor head (not shown) to transfer the Y-axis table 20.

Further, according to FIG. 4, the X-axis table 30 is guide plates 23 in the vertical and horizontal directions on the Y-axis table 20 by respective magnetic bearing modules 40 fixed at four corners thereof. In the state of magnetic levitation at a predetermined distance between the laminated guide 25 of the inner side is conveyed as a guide surface, the drive is made by the linear motor 21 located at the center and the conveying position is linear scale 22 Is measured by.

That is, the magnetic bearing module 40 supports the X-axis table 30 without physical contact by using the magnetic force generated by the current flowing through the coil of the electromagnet 41 embedded therein, and the electromagnet 41 By measuring the displacement through the output signal of the built-in displacement sensor 42 to control the amount of current flowing through the coil of the electromagnet 41 to maintain a constant distance at all times. Here, the magnetic bearing module 40 is the magnitude of the magnetic force of the electromagnet 41 is controlled by a computer (not shown) of the main control unit 50, in particular the displacement sensor 42 of the magnetic bearing module 40 Since the signal is controlled according to the signal output from the signal, the noise component is preferably excluded.

To this end, the magnetic bearing module 40 is formed by embedding the electromagnet 41 and the displacement sensor 42 in the recessed portion 40b of the body 40a, vacuum impregnated with epoxy, and processing the body 40. 40a) The triaxial axis 43 is drawn out to the electromagnet wiring hole 40c and the sensor wiring hole 40d on one side, and the terminal 44 is formed at the end thereof. The triaxial axis 43 is separated / formed into the electromagnet wire 45 and the sensor wire 46 to prevent mutual interference in the magnetic bearing module 40.

Therefore, the signal of the displacement sensor 42 is transmitted to the main control unit 50 along the sensor wiring 46, and the main control unit through the triaxial axis 43 having excellent external noise shielding capability according to the embodiment of the present invention. 50 are delivered to the computer. Here, the sensor wiring 46 made of the triaxial axis 43 is composed of the guard line 43b surrounding the sensor line 43a and the ground line 43c surrounding the guard line 43b. The noise flowing in from the shield is shielded by the cylindrical ground wire 43c, whereby the inflow of noise into the guard wire 43b and the sensor wire 43a therein is suppressed. In addition, since the structure and operation | movement of the electromagnet wiring 45 are also the same as the sensor wiring 46 mentioned above, the detailed description is abbreviate | omitted here.

As described above, according to the magnetic bearing module having the noise preventing wiring according to the present invention, the noise flowing from the outside is shielded by the ground wire which concentrically surrounds the sensor wire and the guard wire, thereby introducing noise into the sensor wire and the guard wire. This is suppressed and there is an effect that can transmit the accurate displacement signal to the main control unit. In addition, by preventing the external noise flowing into the sensor wire and the guard wire to prevent the malfunction by measuring the exact displacement of the table, there is another effect that the table can act actively against external load or disturbance.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (4)

A magnetic bearing module comprising a body in which an electromagnet generating magnetic force is built, a guard built in the vicinity of the electromagnet of the body, and a sensor part embedded in the guard to measure displacement, the sensor for wiring the sensor part. A wire for preventing noise, comprising a wire, a guard wire wired from the guard, and a ground wire wired from the body so as to surround each wire so as to be insulated from each other coaxially, and the ground wire is located at the outermost side. Magnetic bearing module. The magnetic bearing module of claim 1, wherein the triaxial axis line is configured such that the guard line surrounds the sensor line and the ground line surrounds the guard line. The magnetic bearing module of claim 1, wherein each of the body is provided with an electromagnet wiring hole and a sensor wiring hole at one side thereof such that the triaxial shaft is drawn outward. [4] The noise preventing device of claim 3, wherein the triaxial axis is separated and formed so that there is no mutual interference in the magnetic bearing module, and is composed of electromagnet wirings and sensor wirings drawn out to the respective electromagnet wirings and the sensor wirings. Magnetic bearing module with wiring.

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