JPH03161228A - Pneumatic bearing unit with built-in linear motor - Google Patents

Abstract

PURPOSE:To restrain temperature rise of a base and a slider by supporting a stationary element and a movable element through respective spacers, and forming a first gap and a second gap respectively between the stationary element and the base and between the movable element and the slider. CONSTITUTION:Due to supplying current to a linear motor, a stationary element 18 and a movable element 19 are heated, but the stationary element 18 is on the upper face of a base 9 through first spacers 20, 20, the movable element 19 is on the underside of a slider 11 through second spacers 22, 22, respectively supported and fixed through a first gap 21 and a second gap 23. Hereby, transmitting heat to the base 9 and the slider 11 respectively from the stationary element 18 and the movable element 19 are restrained to a minimum. As jetting air from third nozzles 24, 24 opened on the inside of pneumatic bearings 12, 12 for restraint in the horizontal direction flows through a motor 17 part provided with the stationary element 18 and the movable element 19 to cool the elements 18, 19, temperature rise of the base 9 and the slider 11 is restrained to a very little, and thermal deformation of the base 9 and the slider 11 can be neglected in practical use.

Description

[Detailed Description of the Invention] (Industrial Application Field) An air bearing unit incorporating a linear motor according to the present invention is incorporated into a precision cutting machine, semiconductor manufacturing equipment, etc. to perform linear motion of a cutting tool, etc. used for.

(Prior art) For example, in precision cutting machines, cutting blades are
It is necessary to move in a straight line with a high degree of straightness and with a light force. For this reason, the above-mentioned blades and the like have been supported conventionally by air bearing units incorporating linear motors as shown in FIGS. 3 and 4.

In Figs. 3 and 4 showing such a conventional air bearing unit incorporating a linear motor, 1 is a base with a flat top surface, and 2 is a structure above this base 1 relative to the base 1. These are guide rails installed in parallel.

A rectangular frame-shaped slider 3 is supported on the guide rail 2 so as to be movable along the guide rail 2 so as to fit on the outside of the guide rail 2. Inside the slider 3, a compressor etc. Free communication with compressed air supply source,
A distribution channel 13 is provided. Further, on the inner peripheral surface of the slider 3, a plurality of jet ports 4, 4 are provided.
is open, and the compressed air sent into the distribution flow path 13 is ejected from each of the jet ports 4, 4 toward the outer peripheral surface of the guide rail 2, and the slider 3 is guided by the pressure of the compressed air. It is supported against the rail 2.

Further, a stator 5 is mounted on the upper surface of the base 1, and a slider 3 is mounted on the upper surface of the base 1.
A linear motor 7 is constructed by fixing movable elements 6 to the lower surface of each of the sliders 6 and 7, and the slider 3 is made movable along the guide rail 2 based on energization of the linear motor 7.

(Problems to be Solved by the Invention) However, in the conventional air bearing unit having a built-in linear motor, which is constructed and operates as described above, there are problems to be solved as described below.

That is, in order to improve the processing speed of precision cutting machines and semiconductor manufacturing equipment incorporating air bearings, it is necessary to increase the output of the linear motor 7 built into the air bearing. When the output is increased, the heat generated by the linear motor 7 also increases.

In this way, when the heat generated by the linear motor 7 increases,
The base 1 and the slider 3 are thermally deformed, making it difficult for the slider 3 to move smoothly along the guide rail 2, resulting in poor straightness accuracy. For this reason, as shown in FIG. 3, a cooling fan 8 has been conventionally provided at the end between the base 1 and the guide rail 2.
Although cooling air is sent to the movable element 6 and the movable element 6, it is not always possible to achieve sufficient cooling performance. The air bearing unit incorporating the linear motor of the present invention is
This eliminates all of the above-mentioned inconveniences.

(Means for solving the problem) The air bearing unit incorporating the linear motor of the present invention has the following features:
Similar to the conventional air bearing unit with a built-in linear motor described above, there is a base, a guide rail provided parallel to this base, a slider supported by this guide rail by the pressure of compressed air, and a slider supported by the above base. It consists of a fixed stator and a movable element fixed to a part of the slider in a state facing the stator.

Furthermore, in the air bearing unit incorporating the linear motor of the present invention, the stator is supported by the base via a first spacer, and the mover is supported by the slider via a second spacer. By doing so, first and second gaps are formed between the stator and the base and between the mover and the slider, respectively, through which air can freely circulate. (Function) The air bearing unit incorporating the linear motor of the present invention designed as described above has a function itself when supporting the slider so as to be movable along the guide rail, compared to the conventional linear motor described above. It is similar to an air bearing unit with a built-in motor.

However, in the case of an air bearing unit incorporating the linear motor of the present invention, the stator is attached to the base via the first spacer,
By supporting the mover on the slider via a second spacer, air can freely flow between the stator and the base and between the mover and the slider. , since a second gap is formed, it becomes difficult for the heat of the stator and mover that make up the linear motor to be transferred to the base and slider. Therefore, even when the output of the linear motor is increased, the base and slider are less likely to be thermally deformed, and the slider can move smoothly. (Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

FIG. 1 is a sectional view showing a first embodiment of an air bearing unit incorporating a linear motor of the present invention. This air bearing unit with a built-in linear motor has a base 9 with a flat top surface, and a pair of guide rails to, to fixed on the top surface of both ends of the base 9 in the width direction, parallel to each other and spaced apart from each other. , this pair of guide rails 10,
10 and a slider 11 provided above the slider 10.

This slider 11 includes a slider member 11a, a pair of guide rails 10 on the lower surface of the slider member 11a,
A pair of horizontal restraining air bearings 12, 12 are provided, which are suspended and fixed at an interval that can be freely entered between the bearings 10 and 10. A pair of floating air bearing surfaces are provided on the lower surface of both ends of the slider 11 in the width direction, at portions facing the upper surfaces of the pair of guide rails 10, 10.

A distribution flow path 13 provided inside the slider 11 and communicating with a compressed air source (not shown) such as a compressor, and a first jet port 14 opened on the outer surface of each of the horizontal restraining air bearings 12, 12; 14 are in communication with each other through communication passages 15, 15, and compressed air can be freely jetted from the respective jet ports 14, 14 toward the inner surfaces of the respective guide rails to, to. Further, in order to constitute each of the air bearings for floating, second jet ports 16 are provided which are opened at the lower surface of both widthwise ends of the slider 11.
, 16 are also in communication with the distribution channel 13, and can freely jet compressed air from the jet ports 16, 16 toward the upper surface of each guide rail 10.10.

Furthermore, in the air bearing unit incorporating the linear motor of the present invention, the stator 18 of the stator 18 and mover 19 that guard the linear motor 17 is made of a heat insulating material such as ceramic or asbestos. By supporting and fixing to the upper surface of the base 9 via the ring-shaped first spacers 20, 20, the first spacer is provided with a spacer that allows air to freely flow between the lower surface of the stator 18 and the upper surface of the base 9. It forms 1 Jinma 21. Then, by the bolt passing through the first spacers 20, 20,
A stator 18 is fixed to the base 9.

Furthermore, by supporting and fixing the movable element 19 to the lower surface of the slider 11 via ring-shaped second spacers 22, 22, which are also made of a heat insulating material such as cera main ivy or asbestos, the movable element 19 is A second gap 23 is formed between the upper surface and the lower surface of the slider 11, through which air can freely circulate. The movable element 19 is fixed to the slider 11 by a bolt passing through the second spacers 22, 22. Further, third jet ports 24, 24 are provided on the inner surfaces of the horizontal restraining air bearings 12, 12 in a state in which they open toward the linear motor 17 having the stator 18 and the movable element 19. , cooling air can be freely supplied to the linear motor. The third jet ports 24, 24 are connected to the distribution channel 13.
It is easy to process because it communicates with the

The air bearing unit incorporating the linear motor of the present invention configured as described above supports the slider 11 so as to be movable in the horizontal direction along the base 9, and also supports the slider 11 along the guide rails 10, 10. The action when moving the object is as follows.

That is, when using the air bearing unit incorporating the linear motor of the present invention, compressed air is sent from a compressed air source such as a compressor to the distribution channel 13 in the slider 11, and this compressed air is passed through the horizontal restraining air bearing. 12, 12's first jet nozzle 14 and second jet nozzle 16 on the air bearing surface for floating.
Then, the water is ejected toward the inner and upper surfaces of the guide rails 10, 10. As a result, the slider 11 has no ejection from the floating air bearing surface.
16, 16 toward the upper surface of the guide rails 10, 10, the air floats up due to the pressure of the compressed air, and at the same time, from the jet ports 14, 14 of the horizontal restraining air bearings 12, 12, the inner surface of the guide rails 10, 10 Positioning across the width direction C is achieved by the pressure of the compressed air ejected toward the horizontal restraint air bearings 12, 12, and the inner surfaces of the guide rails 10, 10 are prevented from coming into contact with each other. Ru.

When moving the slider 11 along the guide rails 10, 10, if the linear motor 17 composed of the stator 18 and the movable element 19 is energized, the slider 11 can be moved along the guide rails 10, 10.
moves along the guide rails 10, 10.

When the linear motor 17 is energized, the stator 18 and the mover 19 generate heat. Since the slider 11 is supported and fixed to the lower surface of the slider 11 via the spacers 22 and 22 via the first and second gaps 21 and 23, the heat of the stator 18 and the mover 19 is transferred to the base 9 and the slider 11. The amount transmitted is kept to a minimum.

Moreover, the air blown out from the third blow-off ports 24, 24 opened on the inner surfaces of the horizontal restraining air bearings 12, 12 flows through the linear motor 17 portion including the stator 18 and the movable element 19. Since the stator l8 and the movable element l9 are cooled, the temperature rise of the base 9 and slider l1 is suppressed to a small extent, and the amount of thermal deformation of the base 9 and slider 11 is practically ignored. It can be suppressed as much as possible.

Next, FIG. 2 shows a second embodiment of the present invention. In the case of this second embodiment, as in the case of the conventional example shown in FIGS. 3 and 4, a guide rail 2 is provided above a flat base 1 and parallel to this base 1. 2, a rectangular frame-shaped slider 3 is externally supported so as to be movable along the guide rail 2. Inside the slider 3, a compressed air supply source such as a compressor (distribution channel 13 which can be freely communicated with) is provided, and on the inner peripheral surface of the slider 3, a plurality of jet ports 4, 4 are opened. Distribution channel 13
The compressed air sent to the slider 3 is ejected from each of the ejection ports 4, 4 toward the outer peripheral surface of the guide rail 2.
is supported on the guide rail 2 by the pressure of compressed air.

Further, a stator 5 is supported and fixed on the upper surface of the base 1 via first spacers 20, 20, and a movable element 6 is supported and fixed on the lower surface of the slider 3 via second spacers 22, 22. By supporting and fixing, a linear motor 7 is constructed between the base 1 and the slider 3, and the slider 3 is made movable along the guide rail 2 based on energization of the linear motor 7.

A first space 21 is provided between the upper surface of the base 1 and the lower surface of the stator 5 supported and fixed to the upper surface of the base 1 via first spacers 20, 20; A second space 23 is provided between the movable element 6 supported and fixed to the lower surface of the slider 3 via second spacers 22, 22.
each formed.

On the other hand, a plurality of fourth jet ports 25, 25 are opened on the lower surface of the slider 3 and communicate with the distribution channel 13 provided inside the slider 3, and supply water into the distribution channel 13. The compressed air is ejected from each of the fourth ejection ports 25, 25 toward the linear motor 7.

In the case of the air bearing unit with built-in linear motor of the second embodiment configured as described above, the slider 3 is supported with respect to the guide rail 2 by the pressure of compressed air, and the stator 5 and the movable The action itself when moving the slider 3 along the guide rail 2 by energizing the linear motor 7 constituted by the linear motor 7 shown in FIGS. The same is true for air bearing units. However, in the case of the air bearing unit incorporating the linear motor of this embodiment, even if the stator 5 and the movable element 6 generate heat based on the energization of the linear motor 7, the stator 5 will not be able to move around the first spacer 20. , 20 to the upper surface of the base 1.
are supported and fixed to the lower surface of the slider 3 via the second spacers 22, 22 and the first and second gaps 2l, 23, respectively, so that the heat of the stator 5 and mover 6 is uniformly reduced. The amount transmitted to the first slider 1 and the slider 3 is minimized.

Moreover, a fourth jet port 25 opened on the lower surface of the slider 3
, 25 flows through the linear motor 7 portion consisting of the stator 5 and the movable element 6, and
In order to cool down the base 1 and the slider 3,
The temperature rise between the base 1 and the slider 3 is suppressed to a small level, and the amount of thermal deformation between the base 1 and the slider 3 is suppressed to a practically negligible level. In the example shown in FIG. 1, the slider 11 includes a slider member 11a and a pair of horizontal restraining air bearings 12, 12.
However, these may be integrated or separate. Also, a plurality of disks, a plurality of square plates, etc. are used as the first spacer 20 and the second spacer 22, and the stator 18 is fixed to the base 9 with bolts at a location between these spacers 20 and 22. Furthermore, the movable element 19 may be fixed to the slider 11, respectively.

Furthermore, the first spacer 20 and the second spacer 22 are
Although it is preferable to use a heat insulating material, it is not necessary to use a heat insulating material.

Further, the movable element 19 may be provided with a drive coil and the stator 18 may be provided with a magnet, or the movable element 19 may be provided with a magnet and the stator 18 may be provided with a drive coil. (Effects of the invention) The air bearing unit incorporating the glue of the present invention has the following features:
Since it is configured and operates as described above, the heat of the stator and mover that monitors the linear motor can be slightly suppressed from being transmitted to the base and slider, so even if the output of the linear motor is high, The temperature rise of the base and slider can be suppressed to a practically negligible level.

Therefore, it is possible to improve the work efficiency of precision cutting machines that incorporate air bearing units with built-in linear motors while maintaining machining accuracy. 4,

[Brief explanation of the drawing]

Fig. 1 is a vertical side view showing a first embodiment of an air bearing unit incorporating a linear motor of the present invention, Fig. 2 is a longitudinal side view showing the second embodiment, and Fig. 3 is a longitudinal side view showing a conventional linear motor. FIG. 4 is a longitudinal sectional front view showing one example of a built-in air bearing unit, and FIG. 4 is a sectional view taken along line AA in FIG. 3. 1: Base, 2: Guide rail, 3: Slider, 4: Spout, 5: Stator, 6: Mover, 7: Linear motor, 8
:Cooling fan, 9: Base, 10: Guide rail, 11
: slider, 11a: slider member, 12; air bearing for horizontal restraint, 13; distribution channel, 14: first jet port,
15: Communication path, 16: Second spout, 17: Linear motor, 18: Stator, 19: Mover, 20: First spacer, 21: First gap, 22: Second spacer, 23 :
Second gap, 24: Third spout, 25: Fourth spout.

Claims (2)

[Claims] (1) A base, a guide rail provided parallel to the base, a slider supported on the guide rail by the pressure of compressed air, a stator fixed to the base, and a slider facing the stator. In this state, in an air bearing unit incorporating a linear motor having a movable element fixed to a part of the slider, the stator is attached to the base via a first spacer, and the movable element is attached to the first spacer. By supporting each slider through the second spacer,
An air bearing with a built-in linear motor, characterized in that first and second gaps are formed between the stator and the base, and between the movable element and the slider, respectively, allowing free circulation of air. unit. (2) By providing a part of the slider with a spout that opens toward the linear motor equipped with a mover and a stator,
2. The air bearing unit incorporating a linear motor according to claim 1, wherein a part of the compressed air for supporting the slider with respect to the guide rail can be freely blown out toward the linear motor.