WO2015056847A1

WO2015056847A1 - Magnetically levitated transportation apparatus

Info

Publication number: WO2015056847A1
Application number: PCT/KR2014/001165
Authority: WO
Inventors: Ki Chang Lee; Byoung Gun Park; Shi Uk Chung; Ji Woon Kim; Seok Hwan Moon
Original assignee: Korea Electrotechnology Research Institute
Priority date: 2013-10-16
Filing date: 2014-02-13
Publication date: 2015-04-23
Also published as: TWI552254B; JP2016532308A; KR101531656B1; TW201515980A; KR20150044107A; JP6165992B2

Abstract

The present disclosure relates to a magnetically levitated transportation apparatus. In order to effectively transfer a heavy transfer body such as a large-area display panel, the magnetically levitated transportation apparatus includes one or more levitation electromagnets disposed at an upper part of a chamber along a movement direction of a transfer tray to provide a magnetic force for levitating the transfer tray, one or more first ferromagnetic cores disposed on the transfer tray so as to be opposite to the levitation electromagnet, levitating the transfer tray by an attractive action with the magnetic force of the levitation electromagnet, one or more stator coils disposed on at least one surface of an inner side of the chamber along the movement direction of the transfer tray to provide a magnetic force for moving the transfer tray in a horizontal direction, one or more mover propulsion modules disposed on at least one surface of the transfer tray along the movement direction of the transfer tray to provide a horizontal propulsive force to the transfer tray through an attractive or repulsive action with the magnetic force provided by the stator coil, and one or more mover guidance modules disposed along a disposition direction of the mover propulsion module to control a gap between the transfer tray and the chamber by an attractive or repulsive action with the stator coil.

Description

MAGNETICALLY LEVITATED TRANSPORTATION APPARATUS

The present disclosure relates to a magnetically levitated transportation apparatus, and more particularly, to a magnetically levitated transportation system, which can perform servo control on a heavy transfer tray with high accuracy in a vacuum without a limitation in distance.

Generally, magnetically levitated transportation systems have been widely used as transfer systems for transferring a transfer body such as Liquid Crystal Display (LCD) substrate, Plasma Display Panel (PDP) substrate, Organic Light Emitting Diodes (OLED) substrate, semiconductor wafer, transfer tray, cassette or carrier.

The magnetically levitated transportation system can overcome limitations such as particle generation, damage of parts due to friction and abrasion, and noise generation, and at the same time, can transfer objects to be transferred at a high speed.

The magnetically levitated transportation system, which is a system that levitates a transfer body loaded with objects to be transferred using a magnetic force, can achieve a noiseless, low vibration, and ultra-clean transfer system because there is no contact and friction between the transfer body and the rail. Also, the magnetically levitated transportation system can be actuated in a vacuum, and can be actuated in gas or liquid that is harmful to human body. Accordingly, the magnetically levitated transportation system can be applied to various fields.

The magnetically levitated transportation system requires a magnetic levitation force, a guiding force, and a propulsive force. The magnetically levitated transportation system receives the magnetic levitation force and the guiding force from the levitation electromagnet, and receives the propulsive force from a linear induction motor or a linear synchronous motor.

For example, the magnetic force is acquired by a method in which the electromagnet and the transfer body are maintained at a certain gap by controlling a vertical (the same direction as levitation force) attraction force between the electromagnet and the transfer body while controlling a current in the coil of the electromagnet, and the guiding force is generated in a horizontal direction (perpendicular to the levitation force and the propulsive force) between the electromagnet and the transfer body, preventing the transfer body from deviating from the rail.

The magnetically levitated transportation system is being widely used as a system of transferring parts, semi-finished products, and finished products in various kinds of factory automation lines such as manufacturing lines of semiconductors and displays which are needed in ultra-clean environments.

However, since a typical magnetically levitated transportation system is configured to include a levitation electromagnet (including electromagnetic core and driving coil) at the side of a transfer body loaded with a display product such as LCD or LED, heat generated in an electromagnetic coil of the transfer body is delivered to the display product, causing damage of the display product sensitive to heat.

Furthermore, as the sizes of the display panels such as LCDs, LEDs, and OLEDs increase, the weight that the magnetically levitated transportation system has to be supported also increases. For example, in the eighth-generation OLED manufacturing process, the weight of the glass substrate and the transfer tray is expected to be equal to or greater than 1 ton, and the transportation distances for each process are also expected to be several tens of meter.

Accordingly, the size of the electromagnet also increases, and resultant heat generation by the electromagnet is expected to further increase. However, there is a limitation in achieving the foregoing purpose only with the electromagnet applied to a typical magnetically levitated transportation system.

Also, as a display panel with a larger size and a higher resolution is needed, higher accuracy is needed in the transportation process of the display panel. However, there is a limitation in increasing the accuracy in a typical magnetically levitated transportation system.

The present disclosure provides a magnetically levitated transportation apparatus, which can prevent heat generated from a coil from affecting a transfer body, by disposing the coil of the levitation electromagnet in a fixed rail instead of the transfer body.

The present disclosure also provides a magnetically levitated transportation apparatus, which can further increase the cooling efficiency by disposing a coil at the outside of a chamber.

The present disclosure also provides a magnetically levitated transportation apparatus, which includes a mover propulsion module and a mover guidance module disposed at the side of the transfer tray (transfer body) so as to locate the transfer body at a more accurate location while more quickly moving the transfer body.

The present disclosure also provides a magnetically levitated transportation apparatus, which includes a cooling pipe adjacent to a core of a levitation electromagnet to more efficiently remove heat generated in the levitation electromagnet.

In accordance with an exemplary embodiment, a magnetically levitated transportation apparatus comprises: one or more levitation electromagnets disposed at an upper part of a chamber along a movement direction of a transfer tray to provide a magnetic force for levitating the transfer tray; one or more first ferromagnetic cores disposed on the transfer tray so as to be opposite to the levitation electromagnet, levitating the transfer tray by an attractive action with the magnetic force of the levitation electromagnet; one or more stator coils disposed on at least one surface of an inner side of the chamber along the movement direction of the transfer tray to provide a magnetic force for moving the transfer tray in a horizontal direction; one or more mover propulsion modules disposed on at least one surface of the transfer tray along the movement direction of the transfer tray to provide a horizontal propulsive force to the transfer tray through an attractive or repulsive action with the magnetic force provided by the stator coil; and one or more mover guidance modules disposed along a disposition direction of the mover propulsion module to control a gap between the transfer tray and the chamber by an attractive or repulsive action with the stator coil.

The magnetically levitated transportation apparatus may further include: one or more guidance electromagnets disposed on at least one surface of the inner side of the chamber along the movement direction of the transfer tray to provide a magnetic force for controlling the gap between the transfer tray and the chamber; and one or more second ferromagnetic cores disposed on the transfer tray opposite to the guidance electromagnet so as to control the gap between the transfer tray and the chamber by an attractive action with the magnetic force provided by the guidance electromagnet.

The stator coil may have a rectangular shape with a hollow central portion, and the stator coil may have shorter one of length and width parallel to the movement direction of the transfer tray. The guidance electromagnet may include: a core penetrating the chamber wall from the outside to the inside thereof; and a coil wound around the core outside the chamber.

In the mover propulsion module, the resultant magnitude of a magnetic force receiving from surfaces perpendicular to the movement direction of the transfer tray of the rectangular stator coil may be larger than the resultant magnitude of a magnetic force receiving from the surfaces parallel to the movement direction of the transfer tray of the rectangular stator coil.

In the mover guidance module, the resultant magnitude of a magnetic force receiving from a surface parallel to the movement direction of the transfer tray may be larger than the resultant magnitude of a magnetic force receiving from a surface perpendicular to the movement direction of the transfer tray in the rectangular stator coil.

The mover propulsion module may include one or more permanent magnets that surround a top surface or an undersurface of the stator coil, respectively. A polarity of a permanent magnet opposite to the top surface or the undersurface of the stator coil may be one of a north-pole and a south-pole. Also, the polarities of the permanent magnets adjacent to each other may be alternately arranged.

The move guidance module may include one permanent magnet that surrounds a portion of a top surface or an undersurface of the stator coil, respectively, and a polarity of a permanent magnet opposite to the top surface or the undersurface of the stator coil may be one of a north-pole and a south-pole.

The mover guidance module may include two or more permanent magnets that surround a portion of a top surface or an undersurface of the stator coil, respectively, and the permanent magnets of the mover guidance module adjacent to each other may have the same polarity.

A longitudinal direction of the permanent magnet of the mover propulsion module may be perpendicular to the movement direction of the transfer tray, and a longitudinal direction of the mover guidance module may be parallel to the movement direction of the transfer tray.

The levitation electromagnet may include: a core penetrating the chamber wall from the outside to the inside thereof; and a coil wound around the core outside the chamber.

A stator coil driven during a transfer process of the transfer tray may be a stator coil facing the mover propulsion module.

A stator coil driven during a transfer process of the transfer tray may be a stator coil facing the mover guidance module.

A levitation electromagnet driven during a transfer process of the transfer tray may be a levitation electromagnet facing the first ferromagnetic core of the transfer tray.

A guidance electromagnet driven during a transfer process of the transfer tray may be a guidance electromagnet facing a second ferromagnetic core of the transfer tray.

The core may include one or more legs, and the coil may be wound around one or more of the legs of the core.

The magnetically levitated transportation apparatus may further include a cooling pipe disposed adjacent to one or more legs of the core to absorb heat generated in the core.

As described above, a magnetically levitated transportation apparatus according to an embodiment of the present invention has the following effects.

First, semi-finished products or finished products of a display panel such as LCD, LED, or OLED are prevented from being damaged by heat generated in a coil of an electromagnet, by moving the coil of the electromagnet out of a chamber of a magnetically levitated apparatus.

Second, since the heat generation does not have to be considered by moving the coil of the electromagnet out of the magnetic levitation chamber, a larger display panel can be safely transferred by using a large electromagnet with a large number of coil turn to generate a larger magnetic force.

Third, since the deformation of the display panel and the transfer tray due to the heat generation can be prevented by moving the coil of the electromagnet that severely generates heat out of the magnetic levitation chamber, the precise levitation gap control of micrometer level or less can be performed even in the process of transferring the transfer body having a broad area.

Fourth, since a cooling pipe is located at a place adjacent to the coil of the electromagnet and the core, heat generated from the electromagnet can be more efficiently removed.

Fifth, since the mover propulsion module and the mover guidance module in which permanent magnets are arranged differently from each other are disposed at the side of the transfer tray, the propulsion and the position of the transfer tray can be controlled only by a transfer coil without a separate coil.

Exemplary embodiments can be understood in more detail from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view illustrating a magnetically levitated apparatus according to an exemplary embodiment of the present invention;

FIG. 2 is a view illustrating a part A of FIG. 1;

FIG. 3 is a front view illustrating a levitation electromagnet according to an exemplary embodiment of the present invention;

FIG. 4 is a perspective view illustrating a levitation electromagnet according to an exemplary embodiment of the present invention;

FIG. 5 is a front view illustrating a levitation electromagnet according to another exemplary embodiment of the present invention;

FIG. 6 is a perspective view illustrating a levitation electromagnet according to another exemplary embodiment of the present invention;

FIG. 7 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention;

FIG. 8 is a view illustrating a part B of FIG. 7;

FIG. 9 is a perspective view illustrating the part B of FIG. 7;

FIG. 10 is a magnified view illustrating a transfer tray of FIG. 9;

FIG. 11 is a view illustrating a transfer tray equipped with a mover propulsion module and a mover guidance module;

FIG. 12 is a view illustrating an operational relationship and a relative location between a mover propulsion module and a stator coil according to an exemplary embodiment of the present invention;

FIG. 13 is a view illustrating a mover guidance module of a magnetically levitated apparatus according to an exemplary embodiment of the present invention;

FIG. 14 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention;

FIG. 15 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention;

FIG. 16 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention; and

FIG. 17 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

Reference numerals set forth in the Drawings includes reference to the following elements as further discussed below:

10: vaporization source

20: transfer body

100: transfer tray

110: mover propulsion module

120: mover guidance module

200: (vacuum) chamber (outer wall)

300: levitation electromagnet

310: core

320: coil

330: cooling pipe

400: guidance electromagnet

410: core

420: coil

500: stator coil fixing jig

510: stator coil

600: permanent magnet

710: first ferromagnetic core

720: second ferromagnetic core

800: gap sensor attachment jig

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the present invention can be modified into various types, exemplary embodiments will be illustrated in the drawings and described in this disclosure in detail. However, the present invention is not limited to a specific disclosure type, but should be construed as including all modifications, equivalents, substitutes involved in the scope and the technological range of the present invention.

FIG. 1 is a view illustrating a magnetically levitated apparatus according to an exemplary embodiment of the present invention.

An magnetically levitated apparatus according to an exemplary embodiment of the present invention may include a vacuum or non-vacuum chamber 200 in which a process of depositing an LED, LCD, or OLED panel is performed, a transfer tray 100 provided in the chamber 200 to take charge of transferring the LED, LCD, or OLED panel, a levitation magnet 300 that provides a levitation force in an upward direction with respect to the transfer tray 100, a guidance magnet 400 for controlling a horizontal gap between the transfer tray 100 and the chamber 200, a stator coil 510 that provides a horizontal propelling force to the transfer tray 100, and a permanent magnet 600 that moves the transfer tray 100 in a horizontal direction through an attractive force or repulsive force with a magnetic force generated in the stator coil 510.

A vaporization source 10 may be disposed in the chamber to vaporize a material attached to a panel. The inside of the chamber 200 may become vacuum such that the vaporization source 10 is vaporized to allow the vaporization material to be easily attached to a transfer body 20 transferred by the transfer tray 100.

The transfer body 20 may be attached to the transfer tray by an electrostatic chuck. However, a combination between the transfer body 20 and the transfer tray 100 is not necessarily limited to the method that uses the electrostatic chuck, but may be replaced with any other methods in which the transfer tray 20 can be tightly attached to the transfer tray 100. The transfer body 20 of the transfer tray 100 may become a display panel, but the present invention is not limited thereto. Accordingly, any object that needs to be transferred may be transferred by the transfer tray 100.

The transfer tray 100 may be levitated by the levitation electromagnet 300 attached to the upper end of the chamber 200. For this, the transfer tray 100 may include a core disposed at a location opposite to the levitation electromagnet 300. In order to stably levitate the transfer tray 100, the levitation electromagnet 300 may be disposed in two or more rows at the upper end of the chamber 200.

When the transfer tray 100 is levitated in the chamber 200, the stator coil 510 may actuate to transfer the transfer tray 100 to a desired location. For this, the stator coil 510 attached to a fixing jig 500 may generate a magnetic force according to the direction of a current flowing in the coil. Also, each of the stator coils 510 may take charge of one phase of a motor.

The permanent magnet 600 may be disposed at the opposite side to the stator coil 510 to move the transfer tray 100 in a horizontal direction by attractive and repulsive actions of a magnetic field generated by the stator coil 510. The permanent magnet 600 may include a mover propulsion magnet 110 and a mover guidance magnet 120, which will be described in detail below.

The guidance electromagnet 400 may be disposed at an upper end of the stator coil 510 to control a horizontal gap between the transfer tray 100 and the chamber 200. The guidance electromagnet 400 may more accurately control the location of the transfer tray 100.

FIG. 2 is a view illustrating a part A of FIG. 1.

The mover propulsion module 110 and the mover guidance module 120 may be disposed at a portion of the transfer tray 100 adjacent to the chamber 200. The mover propulsion module 110 and the mover guidance module 120 may be disposed at a lower end of the transfer tray 100. However, the mover propulsion module 110 and the mover guidance module 120 may not be necessarily disposed at a lower end, and may be located at a location opposite to the installation location of the stator coil 510. Accordingly, the mover propulsion module 110 and the mover guidance module 120 may be disposed at a side surface or upper end of the transfer tray 100.

The mover propulsion module 110 and the mover guidance module 120 may include the permanent magnet 600 disposed therein. The permanent magnet 600 may be disposed to surround the top surface and the undersurface of the stator coil 510. That is, one permanent magnet 600 may be disposed to surround the top surface of the stator coil 510, and the other permanent magnet 600 may be disposed to surround the undersurface of the stator coil 510. Also, the permanent magnet 600 may cover most of the stator coil 510, and may cover only a portion of the stator coil 510. The shape of the permanent magnet 600 disposed in the mover propulsion module 110 and the mover guidance module 120 may vary according to the purposes thereof.

The stator coil 510 may have one side surface supported by a bottom, a side surface or a specific surface plate of the chamber. The stator coil 510 may be disposed in a plurality along the movement direction of the transfer tray 100 inside the chamber 200 to form a line.

The levitation electromagnet 300 may be disposed over the chamber 200. The levitation electromagnet 300 may be disposed to be adjacent to a location where the top surface of the chamber 200 joins the side surface of the chamber 200, but the present invention is not limited thereto.

The magnetic levitation coil 300 may include a core 310 formed of an iron bar and a coil 320 surrounding the core 310. The core 310 of the levitation electromagnet 300 may be disposed to penetrate the chamber 200 from the outside to the inside. The core 310 may be manufactured to have a plurality of legs. The leg may be disposed in plurality. The coil 320 may be wound around a portion of the core 310 protruding to the outside of the chamber 200. As the coil 320 is disposed outside the chamber 200, not inside the chamber 200 that maintains a vacuum state, an influence on the transfer body 20 by heat generated in the coil 320 can be minimized. Also, since the limitation in the size of the levitation electromagnet 300 due to the heat generation can be overcome, the levitation electromagnet 300 that provides a larger levitation force can be used.

The guidance electromagnet 400 may be disposed on the side surface of the chamber 200. The guidance electromagnet 400 may be manufactured by a similar method to that of the levitation electromagnet 300 to be attached to the chamber 200. The guidance electromagnet 400 may also be manufactured to include a core 410 that penetrates the chamber 200 from the outside to the inside of the chamber 200 and a coil 420 wound around the core 410. The guidance electromagnet 400 may provide a magnetic force for controlling a gap between the transfer tray 100 and the chamber 200. The guidance electromagnet 400 may be disposed in a plurality on a wall of the chamber 200 along the movement direction of the transfer tray 100.

The core may be disposed over the transfer tray 100 at locations opposite to the levitation electromagnet 300 and the guidance electromagnet 400. A first ferromagnetic core 710 disposed at a location opposite to the levitation electromagnet 300 may provide a levitation force that levitates the transfer tray 100 in the air by an attractive action with a magnetic force generated in the levitation electromagnet 300. A second ferromagnetic core 720 disposed at a location opposite to the guidance electromagnet 400 may control a horizontal gap of the transfer tray 100 inside the chamber 200 by an attractive action with a magnetic force generated in the guidance electromagnet 400. In other words, a difference of the magnetic force generated in the guidance electromagnet 400 disposed in a line at left and right sides of the chamber 200 may control the horizontal gap of the transfer tray 100.

FIG. 3 is a front view illustrating a levitation electromagnet 300 according to an exemplary embodiment of the present invention.

The core 310 of the levitation electromagnet 300 may be manufactured to have three legs. The three legs may penetrate the chamber 200 such that a portion of the three legs protrudes to the inside of the chamber 200. The coil 320 may be wound around middle one of the three legs. When a current flows in the coil 320, a magnetic force may be generated along the core 310. Since a portion of the core penetrates into the chamber 200, the transfer tray 100 may be levitated in the air due to the attractive action with the first ferromagnetic core 710 on the transfer tray 100. Also, the chamber 200 may be formed of a non-magnetic substance, and thus may not interrupt the magnetic force generated in the levitation electromagnet 300.

FIG. 4 is a perspective view illustrating a levitation electromagnet 300 according to an exemplary embodiment of the present invention.

The number of windings needs to become larger to provide a larger levitation force. As the number of the coils 320 wound around the core 310 increases, the volume of the levitation electromagnet 300 may increase and simultaneously, heat generated from the coil 320 may increase. This is because the coil 320 acts as a resistor with respect to the flow of a current. Since the coil 320 of the levitation electromagnet 300 is disposed outside the chamber 200, heat generated from the coil 320 can be prevented from being delivered to the inside of the chamber 200. Simultaneously, since a portion of the core 310 protrudes to the inside of the chamber 200, a large levitation force may be directly delivered to the transfer tray 100.

FIG. 5 is a front view illustrating a levitation electromagnet 300 according to another exemplary embodiment of the present invention.

The levitation electromagnet 300 may be manufactured to have two legs. The leg of the core 310 may also be formed to penetrate the chamber 200 from the outside to the inside. The coil 320 may be wound around the two legs of the levitation electromagnet 300.

FIG. 6 is a perspective view illustrating a levitation electromagnet 300 according to another exemplary embodiment of the present invention.

A cooling pipe 330 may be further provided to the levitation electromagnet 300 to remove heat generated from the coil 320. The cooling pipe 330 may be disposed under the coil 320 while being adjacent to the core 310. However, the present invention is not limited thereto, and the cooling pipe 330 may be provided to the levitation electromagnet 300 by any method to effectively remove heat generated from the levitation electromagnet 300.

FIG. 7 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

An magnetically levitated apparatus according to another exemplary embodiment of the present invention may include a chamber 200 in which a process of depositing an LED, LCD, or OLED panel is performed, a transfer tray 100 provided in the chamber 200 to take charge of transferring the LED, LCD, or OLED panel, a levitation magnet 300 that provides a levitation force in an upward direction with respect to the transfer tray 100, a stator coil 510 that provides a horizontal propelling force to the transfer tray 100, and a permanent magnet 600 that moves the transfer tray 100 in a horizontal direction through an attractive force or repulsive force with a magnetic force generated in the stator coil 510. Also, a vaporization source 10 and a transfer body 20 on which a vaporized material is deposited may be provided in the chamber 200.

In FIG. 7, the guidance electromagnet 400 will be omitted unlike FIG. 1. This is because the magnetically levitated transportation apparatus can control the horizontal gap and position of the transfer tray 100 without the guidance electromagnet 400 through the mover propulsion module 110 and the mover guidance module 120 which are provided with the permanent magnet 600 over the transfer tray 100. Accordingly, the guidance electromagnet 400 may be an optional component according to the accuracy of the transfer process of the transfer tray 100.

A vaporization source 10 may be disposed in the chamber to vaporize a material attached to a panel. The inside of the chamber 200 may become vacuum such that the vaporization source 10 is vaporized to allow the vaporization material to be easily attached to a transfer body 20 transferred by the transfer tray 100. A pump (not shown) may be disposed outside the chamber 200 to allow the inside of the chamber 200 to be vacuumed.

The transfer body 20 may be attached to the transfer tray by an electrostatic chuck. However, a combination between the transfer body 20 and the transfer tray 100 is not necessarily limited to the method that uses the electrostatic chuck, but may be replaced with any other methods in which the transfer tray 20 can be tightly attached to the transfer tray 100. The transfer body 20 of the transfer tray 100 may become a display panel, but the present invention is not limited thereto. Accordingly, any object that needs to be transferred may be transferred by the transfer tray 100. Accordingly, a magnetically levitated linear apparatus according to an exemplary embodiment of the present invention is illustrated

The transfer tray 100 may be levitated by the levitation electromagnet 300 attached to the upper end of the chamber 200. For this, the transfer tray 100 may include a first ferromagnetic core 710 disposed at a location opposite to the levitation electromagnet 300. In order to stably levitate the transfer tray 100, the levitation electromagnet 300 may be disposed in two or more rows at the upper end of the chamber 200.

When the transfer tray 100 is levitated in the chamber 200, the stator coil 510 may actuate to transfer the transfer tray 100 to a desired location. For this, the stator coil 510 may generate a magnetic force according to the direction of a current flowing in the coil. The permanent magnet 600 may be disposed at the opposite side to the stator coil 510 to move the transfer tray 100 in a horizontal direction by attractive and repulsive actions with a magnetic field generated by the stator coil 510.

FIG. 8 is a view illustrating a part B of FIG. 7.

The mover propulsion module 110 and the mover guidance module 120 may be disposed at a portion of the transfer tray 100 adjacent to the chamber 200. The mover propulsion module 110 and the mover guidance module 120 may be disposed at a lower end of the transfer tray 100. However, the mover propulsion module 110 and the mover guidance module 120 may not be necessarily disposed at a lower end, and may be located at an appropriate location opposite to the installation location of the stator coil 510. Accordingly, the mover propulsion module 110 and the mover guidance module 120 may be disposed at a side surface or upper end of the transfer tray 100.

The mover propulsion module 110 and the mover guidance module 120 may be disposed at the transfer tray 100 to form a U-shaped wing. However, the shape of the mover propulsion module 110 and the mover guidance module 120 is not limited to the U-shaped wing, but may be manufactured in any shape that can appropriately move the transfer tray 100 by the attractive and repulsive action with the magnetic force of the stator coil 510 at the opposite location to the stator coil 510. For example, the mover propulsion module 110 and the mover guidance module 120 may be manufactured to have a straight-line shape.

A gap sensor attachment jig 800 may be disposed at the end of the mover propulsion module 110 and the mover guidance module 120 to receive a gap sensor (not shown). However, the present invention is not limited thereto, and the gap sensor (not shown) may be disposed at the side of the rail according to various embodiments.

The mover propulsion module 110 and the mover guidance module 120 may include the permanent magnet 600 disposed therein. The permanent magnet 600 may be disposed to surround the top surface and the undersurface of the stator coil 510. That is, one permanent magnet 600 may be disposed to surround the top surface of the stator coil 510, and the other permanent magnet 600 may be disposed to surround the undersurface of the stator coil 510. Also, the permanent magnet 600 may cover most of the stator coil 510, and may cover only a portion of the stator coil 510.

The stator coil 510 may have one side surface thereof fixedly supported by the chamber 200. The stator coil 510 may be disposed in a plurality along the movement direction of the transfer tray 100 inside the chamber 200 to form a line.

The levitation electromagnet 300 may be disposed over the chamber 200. The levitation electromagnet 300 may be disposed to be adjacent to a location where the top surface of the chamber 200 joins the side surface of the chamber 200, but the present invention is not limited thereto. For example, the location of the levitation electromagnet 300 may be appropriately controlled so as to provide a levitation force at a location opposite to the first ferromagnetic core 710 over the transfer tray 100. The second ferromagnetic core 720 over the transfer tray 100 may be selectively omitted when the guidance electromagnet 400 is omitted.

Although not shown, a bearing may be disposed at both ends of the transfer tray 100 in case the levitation force disappears due to the interruption of power supply to the levitation electromagnet 300. Thus, although due to the stopping of the magnetically levitated apparatus according to an exemplary embodiment of the present invention, the power supply to the levitation electromagnet 300 is interrupted and the transfer tray 100 is lowered to the bottom, the stator coil 510 can be prevented from being damaged by the weight of the transfer tray 100.

FIG. 9 is a perspective view illustrating the part B of FIG. 7.

FIG. 9 shows a process of transferring a transfer tray 100 of a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

In FIG. 9, although the mover propulsion module 110 and the mover propulsion module 120 are shown as disposed only at one side of the transfer tray 100, the mover propulsion module 110 and the mover propulsion module 120 may also be symmetrically disposed at the other side of the transfer tray 100 by a similar method.

The first ferromagnetic core 710 may be disposed on the top surface of the transfer tray 100 at a portion where the mover propulsion module 110 and the mover guidance module 120 are disposed.

The levitation electromagnet 300 may be continuously disposed in a line along the first ferromagnetic core 710 at the upper surface of the chamber 200 opposite to the first ferromagnetic core 710. Thus, since the levitation electromagnet 300 form a line along the first ferromagnetic core 710, a levitation force may be provided to the transfer tray 100 even though the transfer tray 100 moves in any horizontal direction.

As the levitation electromagnet 300 is continuously manufactured, the core 310 of the levitation electromagnet 300 may also be continuously manufactured to form one frame. Also, the coil 320 may be wound around the leg of the core 310 to provide a magnetic force. Only the levitation electromagnet 300 facing the first ferromagnetic core may be driven.

The mover propulsion module 110 and the mover guidance module 120 may be disposed at the lower end of the transfer tray 100, and the mover propulsion module 110 and the mover guidance module 120 may include the permanent magnet 600 disposed therein.

A gap sensor attachment jig 800 may be disposed at a wing in which the permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120 are disposed. The gap sensor attachment jig 800 may be equipped with a gap sensor (not shown) to measure a gap between the transfer tray 100 and the chamber 200 and transmit the gap to a controller (not shown) for controlling the transfer of the transfer tray 100.

FIG. 10 is a magnified view illustrating a transfer tray 100 of FIG. 9.

The first ferromagnetic core 710 may be disposed along the one edge of the top surface of the transfer tray 100. The second ferromagnetic core 720 may be disposed adjacent to the first ferromagnetic core 710. Although not shown, the first ferromagnetic core 710 and the second ferromagnetic core 720 may be symmetrically disposed over the transfer tray 100 at the opposite side of the transfer tray 100.

The guidance electromagnet 400 may be disposed on a surface opposite to the second ferromagnetic core 720. Only the guidance electromagnet 400 facing the second ferromagnetic core 720 may be driven.

The mover propulsion module 110 and the mover guidance module 120 may be disposed at a lower portion of the transfer tray 100.

The arrangement of the permanent magnet 600 of the mover propulsion module 110 and the mover guidance module 120 will be described in detail later. The permanent magnet 600 of the mover propulsion module 110 may be disposed in the mover propulsion module 110 such that the longitudinal direction of the permanent magnet 600 directs to an extension direction from the transfer tray 100 to the chamber 200. The permanent magnet of the mover propulsion module 110 may be disposed such that the surface thereof facing the top surface or the undersurface of the stator coil 510 becomes either N-pole or S-pole. The permanent magnets 600 of the mover propulsion module 110 disposed on the top surface and the undersurface of the stator coil 510 may be disposed such that the polarities of the permanent magnets 600 adjacent to each other are alternately arranged. In other words, when the polarity of one of the permanent magnets 600 of the mover propulsion module 110 on the top surface of the stator coil 510 becomes N-pole in an extension direction from the transfer tray 100 to the permanent magnet 600, in the next coil, the polarity becomes S-pole, and then, becomes N-pole.

The permanent magnet 600 of the mover guidance module 120 may be attached to the inner side of the mover guidance module 120 so as to cover only a portion of the stator coil 510. The longitudinal direction of the permanent magnet 600 of the mover guidance module 120 may be configured to be parallel to the movement direction of the transfer tray 100. The permanent magnet 600 of the mover guidance module 120 may be disposed such that the surface thereof facing the stator coil 510 has a single polarity. In other words, the permanent magnets 600 may be mounted in the mover guidance module 120 such that only one of N-pole and S-pole of the permanent magnets 600 is opposite to the stator coil 510.

FIG. 11 is a detail view illustrating a transfer tray 100 equipped with a mover propulsion module 110 and a mover guidance module 120.

Unlike the mover propulsion module 110 and the mover guidance module 120 in FIGS. 2 and 8, the mover propulsion module 110 and the mover guidance module 120 in FIG. 11 may be attached to a side surface of the transfer tray 100. In other words, the mover propulsion module 110 and the mover guidance module 120 may be attached to any location of the transfer tray 100 as long as the mover propulsion module 110 and the mover guidance module 120 are parallel to the movement direction of the transfer tray 100.

The mover propulsion module 110 may be manufactured so as to cover most of the top surface or the undersurface of the stator coil 510. More specifically, the length of the permanent magnet 600 of the mover propulsion module 110 may be similar to the length of the stator coil 510. Also, the longitudinal direction of the permanent magnet 600 of the mover propulsion module 110 and the longitudinal direction of the stator coil 510 may be parallel to each other.

On the contrary, the mover guidance module 120 may be manufactured so as to cover only a portion of the stator coil 510. More specifically, the longitudinal direction of the permanent magnet 600 of the mover guidance module 120 may be configured to be perpendicular to the longitudinal direction of the stator coil 510. The permanent magnet 600 of the mover guidance module 120 may be manufactured into one magnet, or may be attached in plurality to the mover guidance module 120. The mover guidance module 120 may be manufactured so as to cover a surface of the stator coil 510, which is parallel to the movement direction of the transfer tray 100. Particularly, the mover guidance module 120 may be manufactured so as to cover a surface at the side of the transfer tray 100, which is parallel to the movement direction of the transfer tray 100.

The stator coil 510 may be continuously disposed in the chamber 200 parallelly along the movement direction of the transfer tray 100. The stator coil 510 may have a rectangular shape with rounded edges, but the present invention is not limited thereto. The side of the stator coil 510 perpendicular to the movement direction of the transfer tray 100 may be longer than the side of the stator coil 510 parallel to the movement direction of the transfer tray 100.

Since the mover guidance module 120 according to an exemplary embodiment of the present invention uses a coil of a surface parallel to the movement direction of the transfer tray 100, it is possible to control the horizontal gap between the transfer tray 100 and the chamber 200 and the position of the transfer tray 100.

Only the stator coil 510 facing the mover propulsion module 110 may be driven. Also, only the stator coil 510 facing the mover guidance module 120 may be driven.

FIG. 12 is a view illustrating an operational relationship and a relative location between a mover propulsion module 110 and a stator coil 510 according to an exemplary embodiment of the present invention.

The permanent magnet 600 may be disposed in a U-shaped wing of the mover propulsion module 110 facing the top surface or the undersurface of the stator coil 510. The permanent magnets 600 facing the top surface and the undersurface of the stator coil may allow a surface facing the stator coil 510 to have a single polarity, and the permanent magnets 600 adjacent to each other may be disposed such that the polarities thereof are alternately arranged. In FIG. 12, in case of the upper surface of the mover propulsion module 110, the polarity of the permanent magnet 600 may be arranged so as to be N - S - N - S - N - S - N- S-pole, and in case of the lower surface of the mover propulsion module 110, the polarity of the permanent magnet 600 may be arranged so as to be S - N - S - N - S- N - S - N-pole.

The permanent magnet 600 of the mover propulsion module 110 may use a broad surface of the stator coil 510. That is, in order to acquire a larger propulsive force, the surface of the longitudinal direction of the stator coil 510 may be used. When the stator coil 510 is manufactured to have a rectangular shape, as shown in the portion 'a" of FIG. 12, a linear propulsive force may be provided to the transfer tray 100 using an interaction between a magnetic force generated in a transverse surface and a magnetic force of the permanent magnet 600 in the mover propulsion module 110.

A gap α between the permanent magnet 600 and the stator coil 510 of the mover propulsion module 110 may be average about 3 mm. When power is not applied to the levitation electromagnet 300, the transfer tray 100 may drop, allowing the gap between the permanent magnet 600 and the stator coil 510 to be reduced. However, since a mechanical bearing (not shown) can support the transfer tray 100, the drop range of the transfer tray 100 may be about 1 mm. Accordingly, the stator coil 510 may not be damaged. When the levitation electromagnet 300 actuates, the transfer tray 100 may be again levitated. In this case, the levitation electromagnet 300 may provide a levitation force to the transfer tray 100, allowing the transfer tray 100 to rise about 1 mm. Since the weight of the transfer tray 100 used in a large-area display manufacturing apparatus is expected to be about 1 ton, it can be seen that the levitation force allowing the transfer tray 100 to rise about 1mm is significantly large.

FIG. 13 is a view illustrating a mover guidance module 120 of a magnetically levitated apparatus according to an exemplary embodiment of the present invention.

The permanent magnet 600 of the mover guidance module 120 may be disposed such that the surface thereof opposite to the top surface or the undersurface of the stator coil 510 has a single polarity. The polarity of the permanent magnet 600 facing the top surface or the undersurface of the stator coil 510 may be one of N-pole and S-pole. The permanent magnet 600 of the mover guidance module 120 may include one permanent magnet, or may include a plurality of permanent magnets that are connected to each other. When the plurality of permanent magnets 600 are connected to each other, the plurality of permanent magnets 600 may be connected to each other such that all surfaces thereof facing the stator coil 510 have the same polarity, allowing the plurality of permanent magnets 600 to seem to be one magnet. As shown in FIG. 13, the permanent magnets 600 facing the top surface of the stator coil 510 may all have N-pole, and the permanent magnets 600 facing the undersurface of the stator coil 510 may all have S-pole.

When the mover guidance module 120 is viewed from the top, the vertical surface of the mover guidance module 510 may be used. That is, the surface parallel to the movement direction of the transfer tray 100 may be used (see portion 'b' of FIG. 13). In a typical magnetically levitated apparatus, a magnetic force generated from the foregoing surface is not efficiently used. However, in the magnetically levitated apparatus according to an exemplary embodiment of the present invention, the gap between the transfer tray 100 and the chamber 200 can be controlled by an interaction of the surface parallel to the movement direction of the transfer tray 100 of the stator coil 510 and the permanent magnet 600 of the mover guidance module 120, and the position and the yaw of the transfer tray 100 may also be controlled.

FIG. 14 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

In the magnetically levitated transportation apparatus of FIG. 14, a single-sided linear motor may be installed in the center of the chamber 200. That is, the stator coil 510 may be disposed at the center of the upper part of the chamber 200. The permanent 600 opposite to the stator coil 510 may be disposed on the top surface of the transfer tray 100.

The magnetically levitated transportation apparatus of FIG. 14 may be similar to the magnetically levitated transportation apparatuses according to other embodiments in that a levitation force is provided to the transfer tray 100 using the levitation electromagnet 300 and the gap between the transfer tray 100 and the chamber 200 is controlled using the guidance electromagnet 400.

However, in the magnetically levitated transportation apparatus of FIG. 14, the stator coil 510 is disposed on the inner surface of the upper part of the chamber 200, and the permanent magnet 600 may be disposed on the top surface of the transfer tray 100 so as to face the stator coil 100, allowing the propulsion and the position of the transfer tray 100 to be controlled.

For this, the permanent magnet 600 opposite to the stator coil 510 may include a plurality of permanent magnets of the mover propulsion module 110 and mover guidance module 120, which are arranged in a line. The longitudinal direction of the permanent magnet 600 of the mover propulsion module 110 may be orthogonal to the traveling direction of the transfer tray 100, and the longitudinal direction of the permanent magnet 600 of the mover guidance module 120 may be parallel to the traveling direction of the transfer tray 100.

FIG. 15 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

In FIG. 15, the levitation electromagnet 300 fixed on the upper part of the chamber 200 may upwardly levitate the transfer tray 100. The guidance electromagnet 400 disposed at both side surface of the chamber 200 may control a gap between the transfer tray 100 and the chamber 200 during the movement of the transfer tray 100, and may also serve to control the position of the transfer tray 100.

The mover propulsion module 110 and the mover guidance module 120 which include the permanent magnet 600 may be disposed in a line at both sides of the undersurface of the transfer tray 100 to allow the transfer tray 110 to acquire a propulsive force. At a location adjacently opposite thereto, the stator coil 510 may be attached to the chamber 200. The permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120 of the transfer tray 100 may be disposed so as to surround the top surface and the undersurface of the stator coil 510. The stator coil 510 may provide a magnetic force to the permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120 to control the propulsive force and the position of the transfer tray 100.

FIG. 16 is a view illustrating a magnetically levitated apparatus according to another exemplary embodiment of the present invention.

In FIG. 16, the mover propulsion module 110 and the mover guidance module 120 may be disposed only at one side of the transfer tray 100 of the magnetically levitated transportation apparatus. Since the magnetically levitated transportation apparatus according to an exemplary embodiment of the present invention can provide a propulsive force and a guiding force by providing a magnetic force to the permanent magnet 600 of the mover propulsion module 110 and the mover guidance module 120, the mover propulsion module 110 and the mover guidance module 120 may be arranged in a line only at any one part of the transfer tray 100. The permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120 may be configured to surround the top surface and the undersurface of the stator coil 510 while being slightly spaced from the stator coil 510 fixed at the side of the chamber 200.

In FIG. 17, the mover propulsion module 110 and the mover guidance module 120 of the magnetically levitated transportation apparatus may be disposed at a side surface of the transfer tray 100 like a wing. The permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120 may be disposed so as to surround the top surface and the undersurface of the stator coil 510 while being spaced from the top surface and the undersurface of the stator coil 510.

In FIG. 17, the guidance electromagnet 400 may be omitted. In this case, the stator coil 510 fixed on the chamber 200 may control a magnetic force applied to the mover propulsion module 110 and the mover guidance module 120 that are provided to have a wing-shape at the side surface of the transfer tray 100, and thus may control the propulsive force and the position of the transfer tray 100 and the gap from the chamber 200.

Also, as shown in FIGS. 14 to 17, all of the permanent magnets 600 at the opposite side to the stator coil 510 of the chamber 200 may be the permanent magnets 600 of the mover propulsion module 110 and the mover guidance module 120, and the arrangement of the permanent magnets may be similar to those of the FIGS. 9 and 10.

Although a magnetically levitated transportation apparatus has been described with reference to the specific embodiments, it is not limited thereto. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims.

Claims

A magnetically levitated transportation apparatus comprising:
one or more levitation electromagnets disposed at an upper part of a chamber along a movement direction of a transfer tray to provide a magnetic force for levitating the transfer tray;
one or more first ferromagnetic cores disposed on the transfer tray so as to be opposite to the levitation electromagnet, levitating the transfer tray by an attractive action with the magnetic force of the levitation electromagnet;
one or more stator coils disposed on at least one surface of an inner side of the chamber along the movement direction of the transfer tray to provide a magnetic force for moving the transfer tray in a horizontal direction;
one or more mover propulsion modules disposed on at least one surface of the transfer tray along the movement direction of the transfer tray to provide a longitudinal propulsive force to the transfer tray through an attractive or repulsive action with the magnetic force provided by the stator coil; and
one or more mover guidance modules disposed along a disposition direction of the mover propulsion module to control a gap between the transfer tray and the chamber by an attractive or repulsive action with the stator coil.
The magnetically levitated transportation apparatus of claim 1, further comprising:
one or more guidance electromagnets disposed on at least one surface of the inner side of the chamber along the movement direction of the transfer tray to provide a magnetic force for controlling the gap between the transfer tray and the chamber; and
one or more second ferromagnetic cores disposed on the transfer tray opposite to the guidance electromagnet so as to control the gap between the transfer tray and the chamber by an attractive action with the magnetic force provided by the guidance electromagnet.
The magnetically levitated transportation apparatus of claim 2, wherein the guidance electromagnet comprises:
a core penetrating the chamber from the outside to the inside thereof; and
a coil wound around the core outside the chamber.
The magnetically levitated transportation apparatus of claim 1, wherein in the mover propulsion module, the resultant magnitude of a magnetic force receiving from a surface of the stator coil perpendicular to the movement direction of the transfer tray is larger than the resultant magnitude of a magnetic force receiving from a surface of the stator coil parallel to the movement direction of the transfer tray.
The magnetically levitated transportation apparatus of claim 1, wherein in the mover guidance module, the resultant magnitude of a magnetic force receiving from a surface of the stator coil parallel to the movement direction of the transfer tray is larger than the resultant magnitude of a magnetic force receiving from a surface of the stator coil perpendicular to the movement direction of the transfer tray.
The magnetically levitated transportation apparatus of claim 1, wherein the stator coil has a rectangular shape with a hollow central portion, and the stator coil has shorter one of length and width parallel to the movement direction of the transfer tray.
The magnetically levitated transportation apparatus of claim 1, wherein:
the mover propulsion module comprises one or more permanent magnets that surround a top surface or an undersurface of the stator coil, respectively;
a polarity of a permanent magnet opposite to the top surface or the undersurface of the stator coil is one of a north-pole and a south-pole; and
the polarities of the permanent magnets adjacent to each other are alternately arranged.
The magnetically levitated transportation apparatus of claim 1, wherein the move guidance module comprises one permanent magnet that surrounds a portion of a top surface or an undersurface of the stator coil, respectively, and a polarity of a permanent magnet opposite to the top surface or the undersurface of the stator coil is one of a north-pole and a south-pole.
The magnetically levitated transportation apparatus of claim 1, wherein the mover guidance module comprises two or more permanent magnets that surround a portion of a top surface or an undersurface of the stator coil, respectively, and the permanent magnets of the mover guidance module adjacent to each other have the same polarity.
The magnetically levitated transportation apparatus of claim 1, wherein a longitudinal direction of the permanent magnet of the mover propulsion module is perpendicular to the movement direction of the transfer tray, and a longitudinal direction of the mover guidance module is parallel to the movement direction of the transfer tray.
The magnetically levitated transportation apparatus of claim 1, wherein the levitation electromagnet comprises:
a core penetrating the chamber from the outside to the inside thereof; and
a coil wound around the core outside the chamber.
The magnetically levitated transportation apparatus of claim 1, wherein a stator coil driven during a transfer process of the transfer tray is a stator coil facing the mover propulsion module.
The magnetically levitated transportation apparatus of claim 1, wherein a stator coil driven during a transfer process of the transfer tray is a stator coil facing the mover guidance module.
The magnetically levitated transportation apparatus of claim 1, wherein a levitation electromagnet driven during a transfer process of the transfer tray is a levitation electromagnet facing the first ferromagnetic core of the transfer tray.
The magnetically levitated transportation apparatus of claim 2, wherein a guidance electromagnet driven during a transfer process of the transfer tray is a guidance electromagnet facing a second ferromagnetic core of the transfer tray.
The magnetically levitated transportation apparatus of claim 3 or 11, wherein the core comprises one or more legs, and the coil is wound around one or more of the legs of the core.
The magnetically levitated transportation apparatus of claim 16, further comprising a cooling pipe disposed adjacent to one or more legs of the core to absorb heat generated in the core and coil.