KR20010044157A - Brushless, coil core type linear motor and linear motion apparatus having the same - Google Patents

Abstract

PURPOSE: A brushless coil core type linear motor and linear driving system having the same is provided to minimize the size of a yoke by optimizing flux flow of a permanent magnet, and achieve an improved operational efficiency by minimizing spacing between permanent magnets and increasing flux density. CONSTITUTION: A linear driving system(1) comprises a main body(2), a linear motor(3) positioned at the center of the main body, a slide part(5) positioned at both sides of the main body and which is driven in a linear fashion by the linear motor; and linear bearing guides(6) for bearing-supporting the slide part against the main body. Since the linear motor is positioned at the center of the main body and linear bearing guides are arranged at the left and right of the linear motor to be symmetric with each other, an improved strength of the driving system against a collision or an external impact is obtained.

Description

Brushless coil core type linear motor and linear drive unit with this motor {BRUSHLESS, COIL CORE TYPE LINEAR MOTOR AND LINEAR MOTION APPARATUS HAVING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless coil core type linear motor and a linear drive system provided with the linear motor, in particular a linear type having a w-shaped yoke with an actuator using an I-shaped coil core wound coil and driven by alternating current. A linear drive system is provided with a motor and this linear motor.

In general, linear drive systems are used to control position and speed according to Cartesian coordinates in semiconductor equipment and machine tools. Such a system uses a conventional rotary motor to convert the rotary motion into a linear motion or use a linear motor. Since the system using the rotary motor converts the rotary motion into linear motion by using a ball screw, rack pinion, belt, etc., the linear motion is limited because the high speed and high precision servo operation was limited due to its inertia and mechanical friction. There is a need for linear motors or linear drive systems that can be driven directly.

However, in the case of coreless type linear motors that have no change in thrust or speed among existing developed linear motors, the thrust is very small or the height of the linear motor is very high, which causes fatal problems in stability and position accuracy. It was. In the core type, a medium (for example, a ferromagnetic core) that generates a force by a permanent magnet in the center of the coil does not exist, and the thrust generated per unit volume is small. In order to overcome this problem, two sets of yoke and coil were generally connected in parallel. In this case, since the size of the linear motor increases, a coil core type linear motor has been developed to minimize the increase in size and increase the thrust. Coils can be superimposed so that other coils can be placed in the center of the coils to increase the density of the coils. However, the thickness of the entire coils increased, resulting in the loss of magnetic flux by the permanent magnets.

Conventional movers have a thick overall thickness of the coil. An example is shown in FIG. As shown in FIGS. 10A and 10B, in the conventional winding coil 22, the transverse portions 22a and 22b and the longitudinal portions 22c and 22d move linearly of the mover 13. Positioned staggered in the direction L, the width g of the entire mover 13 is increased by more than twice the winding coil 22. On the other hand, in the case of the coil of the conventional coil core type mover shown in Fig. 11, the bent portions 33a and 33b of the winding coil form the stage of d with respect to the coil portion sandwiched between the permanent magnets of the winding coil. In the case of overlapping arrangement, the bent portions 33a and 33b have a thickness of 3d, which in turn increases the basic thickness of the coil and causes a distance between the yokes.

In the conventional linear motor, the yoke is large or the thickness of the coil forming the mover is thickened, which inevitably increases the size of the linear motor and the linear driving system using the same.

An object of the present invention to overcome this problem is to achieve a high speed, high acceleration, high output performance in a smaller size, brush-free I-shaped coil core AC linear motor that can accurately perform position, speed, force control, etc. And to provide a linear drive system.

1 is a perspective view of a linear drive system having a brushless I-shaped coil core AC linear motor according to an embodiment of the present invention.

2 is a front view of the linear drive device of FIG.

3 shows the brushless I-shaped coil core AC linear motor of FIG.

4 is a structural diagram of a W-shaped yoke and a permanent magnet of the linear motor of FIG.

5 is a flow chart of magnetic flux of a W-shaped yoke and a permanent magnet of the linear motor of FIG.

(A) and (b) of FIG. 6 are a perspective view and a side view showing the shape of a coil in the I-shaped coil core type mover of the linear motor of FIG.

7 is a cross-sectional view taken along the line A-A of FIG. 6 (a).

8 is a layout view showing an I-shaped coil core coil set positioned between permanent magnets

(A) of FIG. 9 is a current waveform diagram applied to three coils for the magnetic flux waveform of the permanent magnet of the I-shaped coil core AC linear drive control system, and (b) is the magnetic flux waveform of the permanent magnet.

(A) and (b) of FIG. 10 are cross-sectional views taken along a line B-B and a plan view showing the shape of a coil in a concentric mover according to the prior art and a method of arranging the same.

(A) and (b) of FIG. 11 are a side view and a cross-sectional view showing a shape of a coil in a coil core type mover and a method of arranging the same according to the prior art.

* Explanation of symbols for the main parts of the drawings

1: linear drive system 2: body 3: drive linear motor

4: linear scale 5: slide part 6: bearing guide 11: yoke

12: permanent magnet 13: mover 14: winding coil 15: fixing member

According to one aspect of the present invention, there is provided a linear motor having a W-shaped yoke and provided with an I-shaped mover coil. According to another aspect of the invention, a linear drive system with such a linear motor is provided. In the linear drive device of the present invention, a linear driving guide (linear motor) for linearly driving the slide portion with respect to the main body, a linear scale for measuring its position to control the movement of the slide portion, and a linear bearing guide bearing the slide portion with respect to the main body are provided. In the brushless AC linear drive system included, a single drive device was placed at the center of the main body and linear guides were installed on the left and right sides to provide a strong design against collision and external impact.

DETAILED DESCRIPTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 shows a perspective view of a linear drive system with a brushless I-shaped coil core AC linear motor according to the present invention. 2 shows a front view. 1 and 2, the drive control system 1 includes a main body 2, a drive device (linear motor) 3 located at the center of the main body 2, and a drive device located on both sides of the main body. And a linear bearing guide (linear bearing or linear motion guide) 6 which supports the slide portion 5 driven linearly by the bearing and supports the slide portion with respect to the main body.

As can be seen from FIG. 1 and FIG. 2, the drive device 3 is located at the center of the overall system structure, and the bearing guides 6 are symmetrically arranged to the left and right of the drive device 3. Therefore, it is possible to support not only the thrust of the drive device acting on the slave part 5 and the load of the moving object, but also the rotational force and torsion caused by the collision or externally acting force. The linear scale 4 used as the position measuring device is arranged outside the bearing guide 6. As a result, deformation due to the force of the linear scale 4 is minimized. In addition, since the linear scale 4 and the drive device 3 maintain a constant interval, the influence of heat or electromagnetic noise generated in the drive device can be eliminated.

The linear scale 4 can use a well-known thing, and is for measuring and controlling the position of the drive device 3 or the linear drive system 1. Since the slide part 5 and the linear bearing guide 6 can also use a well-known thing, it is not described in detail in this specification.

3 shows the drive device 3 in detail. 1, 2, and 3, the linear motor 3 includes a stator and a mover. The stator includes a W-shaped yoke 11 (also referred to as an 'E'-shaped yoke) and a plurality of permanent magnets 12. 1 to 4, the yoke 11 has a base connection portion 11d and three wings 11a, 11b, 11c extending in parallel with the base portion. The permanent magnet 12 is attached to the wing so that each wing facing each other on the opposite side. Permanent magnets are magnetized by alternating N and S poles at regular intervals. Permanent magnets are arranged to face different poles. In addition, the permanent magnets disposed on both sides of the center wing portion 11a are also disposed to face each other with polarity.

Conventionally, a U-shaped yoke is used to fix a magnet as a stator. For thrust, these U-shaped yokes can be connected in parallel to form a stator. However, in the case of connecting the U-shaped stators in parallel, a flow of magnetic flux is formed in each U-shaped yoke. 4 and 5, however, when the letter W is formed, the flow of magnetic flux is not only facing the permanent magnet 12a but also the permanent magnet 12b positioned opposite to the center wing portion 11a (see the arrow in FIG. 5). ) Can be extended to maximize the efficiency of the permanent magnet to minimize the thickness of the permanent magnet. In addition, the thickness of the center wing portion 11a of the W-shaped yoke 11 can be minimized. Using a W-shaped stator instead of a U-shaped stator can reduce the size of the yoke by about 50% for the same performance.

The mover 13 has a plurality of rectangular ring-shaped winding coils 14 interposed between the permanent magnets. The slide part is fixedly supported by the upper part of the movable element 13. Referring to FIG. 6, a coil winding 14 having a substantially rectangular ring shape inside the movable element 13 is positioned between the permanent magnets facing each other vertically across the line of magnetic force of the permanent magnet and extending in the direction of the arrow F. FIG. Longitudinal sections (driving linear coil sections) 14c and 14d, and transverse sections (connection coil sections) 14a and 14b which connect both longitudinal sections and are located at a portion away from the permanent magnet. .

As best shown in Fig. 5 (b), the upper and lower transverse portions 14a and the transverse portions 14b are bent and biased with respect to the longitudinal portions 14c and 14d therebetween, It is biased to form a stage by 1/2 (ie 1 / 2d) of the thickness d of the longitudinal section. When the winding coils configured as described above are arranged to overlap each other as shown in FIGS. 6 (a) and 6 (b), the longitudinal sections 14c and 14d become d equal to the thickness of the coil and the transverse sections 14a and 14b. Becomes 2d. 6 is a cross-sectional view taken along line AA of FIG. 7, in which the transverse portions 14a and 14b of one winding coil overlap the transverse portions of the other winding coils at the top and the bottom of the coil. It can be seen that the thickness is formed, and the longitudinal portions 14c and 14d of one winding coil are arranged side by side with the longitudinal portions of the other winding coils so that the thickness of the mover is maintained at d in the longitudinal portion.

Fig. 8 is a longitudinal sectional view showing the relative positions of the coil of the mover and the permanent magnet of the stator, and it can be seen that one longitudinal section of the three winding coils is disposed corresponding to each pole. The winding coils are composed of three sets, which are called three-phase coils. The magnetic flux generated by the permanent magnet has a sine wave (sine wave) type as shown in Fig. 9B. In this case, the positive part corresponds to the magnetized pole of the N pole, and the negative part corresponds to the magnetized pole of the S pole.

Each coil (drive coil unit in the longitudinal direction) is driven with a current to generate a magnetic flux having a π / 2 (90 °) phase difference at an electric angle with a sine wave of the magnetic flux of the permanent magnet to maximize the thrust generated by driving the slide unit.

In addition, as shown in FIG. 9 (a), a sinusoidal wave having a phase difference of 2 / 3π (120 °) in three winding coils as shown in FIG. Apply a sine wave current. Fig. 9A shows current waveforms applied depending on the positions of the coils A, B, and C with respect to the permanent magnets.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto. Those skilled in the art will appreciate that modifications and variations can be made without departing from the spirit and scope of the present invention and that such modifications and variations also fall within the present invention.

According to the configuration of the present invention as described above, the invention is to minimize the size of the yoke (11) by optimizing the magnetic flux flow of the permanent magnet using the W-shaped yoke (11), the winding coil 14 is bent to position each other In this case, the longitudinal portions 14c, 14, and d are fitted to each other and positioned on the same plane, thereby minimizing the angular spacing between opposing permanent magnets 12 and increasing the magnetic flux density to improve operating efficiency. And by minimizing the thickness of the transverse portion it can minimize the gap between the wings of the yoke.

Claims (1)

In a linear drive system having a stator and a mover, The stator has a yoke having wings that are connected to each other and connected to each other by a connecting portion at one side, and a permanent magnet fixed in a position facing the wings, The mover includes a plurality of annular winding coils positioned between the permanent magnets, wherein the winding coils comprise a longitudinal linear coil portion crossing the magnetic flux and a connecting coil portion connecting the linear coil portion, wherein the connection portion Wherein the connecting coil portion is bent relative to the linear coil portion and is biased by about one half of the thickness of the linear coil portion.