JP2003065331A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator which suppresses the vibration and is suitable for being used for a straight line guide bearing and the like. SOLUTION: As this actuator is equipped with counter bearings 330a, 330b which are connected on the opposite side to the side where main bearing 320a, 320b are fitted to the endless belt 331, having a drive pulley 309 and a driven pulley 310a in between and being movable along counter guide rails 331a, 331b, a reaction force caused in acceleration or deceleration is suppressed by moving the main bearings 320a, 320b and the counter bearings 330a, 330b to the opposite direction and thus the suppression of vibration is achieved. Furthermore, as the guide rails 304a, 304b and the counter rails 331a, 331b have the same number of the rails with two or more and the same configuration, so it the main bearings 320a, 320b and the counter bearings 330a, 330b are stably supported even when the endless belt 311 is moved in high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator suitable for use in, for example, a linear guide bearing device such as a manufacturing device.

[0002]

2. Description of the Related Art For example, in a manufacturing apparatus, a linear guide bearing device is used to drive an object (object to be conveyed) such as a work. FIG. 7A is a perspective view showing a linear guide bearing device 100 according to the related art.
(B) is a view of the configuration taken along line VIIB-VIIB and viewed in the direction of the arrow.

Rail support bases 102 and 103 are screwed onto both ends of the base 101. Rail support 1
A guide rail 104 having a rectangular cross section is arranged so as to be bridged over 02 and 103. On the side of the rail supports 102 and 103, on the base 101,
The motor support 105 and the pulley support 10 having a U-shaped cross section
6 and 6 are arranged.

A motor 108 is mounted on the motor support 105 with a rotating shaft (not shown) protruding downward. The rotary shaft has a toothed drive pulley 109.
Is attached. A pulley housing 110 that rotatably supports a toothed driven pulley 110 a is attached to the pulley support 106. Drive pulley 10
9 and the driven pulley 110a between the guide rail 10
A toothed belt (endless belt) 111 is stretched in the direction along the line 4. In the present specification, the “endless belt” includes not only an endless belt originally, but also an endless belt obtained by joining both ends of an endless belt having a desired length.

As shown in FIG. 7B, the toothed belt 1
A part of 11 is the air bearing unit 1 by the fixing tool 121.
It is attached to 20. The air bearing unit 120 to which a work (not shown) or the like is attached is configured so that four rectangular plates 122 to 125 are combined vertically and horizontally around the guide rail 104 and are movable along the guide rail 104. Pockets 122a to 125a are provided inside the rectangular plates 122 to 125, and the guide plates 122 to 125 are slightly separated from the guide rail 104 by compressed air supplied from an air source (not shown). , It can move with almost no friction.

[0006]

According to such a linear guide bearing device of the prior art, it is advantageous in that it has a lightweight and simple structure and is low in cost. By the way, in a semiconductor manufacturing apparatus and the like, there is a tendency to dislike mechanical vibration. However, according to the prior art linear guide bearing device,
Since the air bearing unit 120 for transporting the work has a relatively large mass, there is a possibility that vibration may occur due to an imbalance of the mass, especially during acceleration / deceleration. In order to suppress such vibration, it is necessary to increase the rigidity of the device, but this causes a problem that the device becomes heavy and large.

[0007] Therefore, an object of the present invention is to provide an actuator suitable for use in a linear guide bearing device or the like, which is lightweight and simple and which can suppress vibration.

[0008]

[Means for Solving the Problems] In order to achieve the above object,
The actuator of the present invention includes a drive pulley that is rotationally driven by a drive device, a driven pulley that is rotatably supported, an endless belt that is stretched between the drive pulley and the driven pulley, and two or more. Guide rail, a guide bearing device having a main bearing connected to the endless belt and movable along the guide rail, a counter guide rail having the same number and shape as the guide rail, and the endless belt. On the other hand, a counter bearing having the same mass as that of the main bearing, which is connected to the side on which the main bearing is attached on the opposite side across the pulleys and is movable along the counter guide rail, is provided. And a counter bearing device.

[0009]

According to the actuator of the present invention, the drive pulley rotatably driven by the drive device, the driven pulley rotatably supported, and the endless belt wound between the drive pulley and the driven pulley. And a guide bearing device having two or more guide rails and a main bearing connected to the endless belt and movable along the guide rails, and a counter guide rail having the same number and shape as the guide rails. And a counter having the same mass as the main bearing, which is connected to the endless belt on the side opposite to the side on which the main bearing is mounted with the pulleys in between and is movable along the counter guide rail. Since it has a counter bearing device including a bearing, by moving the main bearing and the counter bearing in opposite directions,
The reaction force of the main bearing that occurs during acceleration or deceleration can be suppressed, and thus vibration can be suppressed.
Moreover, since the guide rails and the counter guide rails have the same number of two or more and the same shape, the main bearing and the counter bearing can be stably maintained even when the endless belt is transferred at high speed. I can support you. Since the main bearing and the counter bearing have the same mass, the main bearing is generated when the work is not attached to the main bearing or when the endless belt is operated at high speed during acceleration or deceleration. The reaction force of can be suppressed.

Further, if the endless belt is connected to the main bearing and the counter bearing via a leaf spring, even if the position of the endless belt shifts in the vertical direction (axial direction of the pulley), It is possible to prevent unnecessary force from being applied to both bearings.

Further, the fixed position of the endless belt connected to the main bearing is offset from the axial center of the main bearing, and the center of gravity of the entire movable portion of the guide bearing device and the object to be conveyed is combined. By making the positions substantially coincide with each other, the moment load applied to the main bearing can be suppressed, and thus efficient driving can be performed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing a linear guide bearing device 300 including an actuator according to the first embodiment. FIG. 2 is a top view showing the linear guide bearing device 300. FIG. 3 is a side view showing the linear guide bearing device 300. However, the hidden part shown by the broken line shows only the main part. Drive pulley 309, driven pulley 310a, and guide rails 304a and 304b
, Main bearings 320a and 320b, counter guide rails 331a and 331b, and counter bearings 330a and 33
An actuator is constituted by 0b.

Rail support plates 302, 302 are mounted on both ends of the base 301. Rail support plate 3
Guide rails 304a and 304b having a cylindrical cross section are arranged in parallel vertically so as to be bridged over 02 and 302. Rail support plates 303 and 303 are attached next to the rail support plates 302 and 302,
The counter guide rails 331a and 331b, which have a cylindrical cross section, are laid over these so that the guide rails
4a and 304b (in FIG. 2, the counter guide rails 331a and 331b overlap the guide rails 304a and 304b). Outside the rail support plates 302, 302, on the base 301,
Motor support 305 and pulley support 30 having a U-shaped cross section
6 and 6 are arranged.

A motor 308 is attached to the motor support 305 in a state in which a rotary shaft 308a is projected downward in the drawing. On the upper part of the motor 308, the rotating shaft 308
An encoder 315 that detects the rotation angle of a is arranged. A drive pulley 309 having teeth is attached to the lower end of the rotary shaft 308a. Pulley support 306
Includes a pulley housing 310 that rotatably supports a toothed driven pulley 310a attached to a shaft 310b.
Is provided. Drive pulley 309 and driven pulley 31
0a, a toothed belt 311 as an endless belt is stretched in the direction along the guide rails 304a and 304b.

A part of the toothed belt 311 is a fixing member 32.
1 (FIG. 3) attached to the housing 320c. The main bearing 3 is provided in the upper and lower through holes of the housing 320c having a substantially U-shape when viewed from the direction shown in FIG.
20a and 320b are fixed. That is, the housing 320c connects the main bearing 320a that engages with the guide rail 304a and the main bearing 320b that engages with the guide rail 304b to each other. Toothed belt 31
1 is attached to the housing 320c as shown in FIG.
As shown in FIG. 5, it is the middle of the line connecting the central axes of the main bearings 320a and 320b, that is, the main bearings 320a and 32b.
The center of gravity of 0b is passed. Main bearing 3
Reference numerals 20a and 320b are so-called porous static pressure gas bearings, the inner peripheral portion of which is formed of graphite porous, and compressed air supplied from an air source (not shown) causes the main bearings 320a to the guide rails 304a and 304b. 320b is slightly separated so that it can move with almost no friction. Although the main bearings 320a and 320b are fitted in the housing 320c without a gap, the main bearings 320a and 320b are not fitted to the guide rails 304a and 30b.
4b is fitted with a gap of about 5 μm.
Main bearings 320a, 320b and guide rails 304a,
A guide bearing device is configured with 304b.

Further, a housing 330c having the same shape as that of the housing 320c so as to face the housing 320c as seen from the direction shown in FIG. 3 but arranged in the opposite direction is provided with a fixing member 332 on a part of the endless belt 311. Is attached using. Counter bearings 330a and 330b are fixed in through holes in the upper and lower portions of the housing 330c. That is, the housing 330c includes the counter bearing 330a that engages with the counter guide rail 331a and the counter bearing 3 that engages with the counter guide rail 331b.
20b and 20b are connected to each other. As shown in FIG. 3, the mounting position of the toothed belt 311 with respect to the housing 330c is the middle of the line connecting the central axes of the counter bearings 330a and 330b, that is, the counter bearing 330a.
And 330b through the center of gravity.
The counter bearings 330 a and 330 b are porous static pressure gas bearings having a cylindrical outer shape, and are counter guide rails 33.
It has an inner diameter that fits into the 1a 331b and is movable along the counter guide rails 331a and 331b. The counter bearing 330 is attached to the housing 330c.
Although the counter bearings 330a and 330b are fitted with each other without any gap, the counter bearings 330a and 330b have the counter guide rail 331.
A and 331b are fitted with a gap of about 5 μm. The counter bearings 330a and 330b and the guide rails 331a and 331b constitute a counter bearing device.

As shown in FIG. 2, the photo sensor S is provided on the side of the counter guide rails 331a and 331b.
1, S2, S3 are arranged, and counter bearings 330a, 3
The member A to be detected that moves together with 30b is detected. The motor 308 can be stopped at the time of overrun based on the signals from the photosensors S1, S2, and S3.

The operation of this embodiment will be described below.
Compressed air supplied from an air source (not shown) causes the main bearings 320a, 3b to move against the guide rails 304a, 304b.
20b is slightly separated from the counter guide rails 331a and 331b.
a and 330b are maintained in a slightly separated state.

Here, the motor 308 drives the drive pulley 309.
Is driven, the main bearings 320a and 320b move along the guide rails 304a and 304b with almost no friction, and the counter bearings 330a and 330b move with respect to the counter guide rails 331a and 331b with almost no friction. At this time, the driving reaction force generated during acceleration or deceleration is the main bearing 32.
Counter bearing 33 provided to face 0a and 320b
The vibrations can be suppressed by being offset by 0a and 330b. Particularly, in the present embodiment, the counter guide rail 3 is different from the guide rails 304a and 304b.
31a and 331b are provided in the same number, and the diameters and arrangements thereof are the same. In addition, the main bearings 320a and 320b and the housing 320c and the counter bearings 330a and 330 are provided.
Since b and the housing 330c have the same shape, the imbalance between the two can be eliminated, and the drive reaction force generated during acceleration or deceleration can be suppressed as much as possible.

Further, the center of gravity of the main bearings 320a and 320b, the housing 320c, and the work (not shown) to be conveyed are located directly above the endless belt 311, and the center of gravity of the counter bearings 330a and 330b and the housing 330c are endless belt 311. By making it directly above, the moment force due to the driving force of the endless belt 311 can be reduced. Further, since the main bearings 320a, 320b and the counter bearings 330a, 330b have the same mass, it is possible to suppress the reaction force of the main bearings generated during acceleration or deceleration when the endless belt 311 is operated at high speed. .

FIG. 4 is a front view showing a linear guide bearing device 400 including an actuator according to the second embodiment. FIG. 5 is a view of the configuration of FIG. 4 taken along the line VV and viewed in the direction of the arrow. The second embodiment differs from the embodiment shown in FIG. 1 in that instead of the housing 320c (FIG. 3), the leaf springs 420c are used to move the main bearings 320a and 320b to each other in the directions along the guide rails 304a and 304b. Δ
Connected in an offset state only, and housing 33
0c (FIG. 3), the leaf springs 430c are used to connect the counter bearings 330a and 330b to the counter guide rails 331.
They are connected in a state of being offset from each other by Δ in the direction along a and 331b.

As shown in FIG. 5, the endless belt 311 is
The main bearings 320a and 320b are connected to a holder 420d made of a spring plate material bent in a crank shape by a fixing tool 322 and a restraining plate 420e, and the counter bearings 330a and 330b are connected. A holder 430d made of a spring plate material bent in a crank shape is fixed by screws using a fixture 332 and a restraining plate 430e. The work may be mounted on either of the main bearings 320a and 320b.
Drive pulley 309, driven pulley 310a, guide rails 304a and 304b, and main bearings 320a and 320b
The counter guide rails 331a and 331b and the counter bearings 330a and 330b form an actuator. As shown in FIG. 5, the main bearings 320a, 320a
b is a bearing portion 320aa, 3 made of porous graphite that fits into the guide rails 304a, 304b with a gap.
20ba and a bearing housing 3 that encloses 20ba without a gap
20ab and 320bb, and counter bearings 330a and 330b are guide rails 331a and 331.
Porous graphite bearing parts 330aa and 330ba fitted in b with a gap and bearing housings 330ab and 330bb enclosing it without gaps (the same applies to the modification of FIG. 6 described later).

According to this embodiment, as in the first embodiment, the main bearings 320a and 320b are attached to the housing 320.
Guide rail 304a, when rigidly fixed with c
The abutment of the main bearings 320a and 320b caused by bending of the 304b due to its own weight or poor parallelism can be suppressed by elastically coupling with the spring plate 420c, and the counter bearings 330a and 330b can be suppressed. By elastically connecting the counter bearings 330a and 330b by using the spring plate 430c, when the rigid fixing is performed by the housing 330c, the competition between the counter bearings 330a and 330b caused by the deflection of the guide rails 331a and 331b due to its own weight or the poor parallelism. Can be suppressed.

Further, when the main bearings 320a and 320b are connected without being offset, the inclination becomes large with respect to the moment load in the direction shown by the arrow M in FIG. 4, but by offsetting the main bearings 320a and 320b,
It is possible to suppress the inclination with respect to the moment load without increasing the bearing size. That is, the rigidity against such moment load can be improved by the relatively small bearing. Also, the counter bearings 330a and 330b
In the case of coupling without offsetting, the inclination with respect to the counter guide rails 331a, 331b also becomes large. However, by offsetting the counter bearings 330a, 330b, the inclination with respect to this moment load can be increased without increasing the bearing size. Can be suppressed. That is, the rigidity against such moment load can be improved by the relatively small bearing.

Further, since the holder 420d is formed of a plate material having high elasticity, even if the endless belt 311 is displaced in the vertical direction in FIG. 5, the endless belt 311 and the main bearings 320a and 320b.
Since the vertical displacement of the holder 420d can be absorbed by the deflection of the horizontal portion of the holder 420d in FIG. 6, it is unlikely that the main bearings 320a and 320b are subjected to an extra vertical force in FIG. On the other hand, the guide rails 304a and 304b
In the direction, since the rigidity of the holder 420d is high, there is no problem that the transmission of the driving force is delayed. Although the spring plate 420c is attached to one side of the main bearings 320a and 320b in FIG. 5, the plate thickness of the spring plate 420c can be reduced by attaching it to both sides.
Further, the spring plate 420c shown in FIG. 5 may be removed, and the plate thickness of the holder 420d may be increased to be used instead of the spring plate 420c.

Similarly, since the holder 430d is made of a highly elastic plate material, the endless belt 311 and the counter bearing 33 are formed.
0a, 330b vertical displacement, holder 430d
5, it can be absorbed by the deflection of the horizontal portion, so that the counter bearings 330a and 330b are less likely to be subjected to extra vertical force in FIG. On the other hand, in the direction of the counter guide rails 331a and 331b, the holder 430 is
Since the rigidity of d is high, there is no problem that the driving force is delayed. In FIG. 5, the spring plate 430c is attached to one side of the counter bearings 330a and 330b, but if it is attached to both sides, the spring plate 430c is attached.
The plate thickness of can be reduced. Further, the spring plate 430c shown in FIG. 5 may be removed, and the plate thickness of the holder 430d may be increased to be used instead of the spring plate 430c.

FIG. 6 is a view similar to FIG. 5, showing a modification of the linear guide bearing device. In this modified example, a holder 420d ′ connecting the main bearings 320a and 320b,
Holder 43 that connects the counter bearings 330a and 330b
0d ′ is asymmetrical, and specifically, the holder 420
The joint between d ′ and the endless belt 311 is connected to the main bearing 320.
It is shifted to the left in FIG. 6 by δ from the axes of a and 320b. Since the pulley diameter of the endless belt 31 does not change, the joint between the holder 430d ′ and the endless belt 311 is also shifted by δ to the left in FIG. 6 from the axial centers of the counter bearings 330a and 330b. The work W is attached to the side surface (left side in FIG. 6) of the main bearing 320b, as indicated by the chain double-dashed line.

In the structure of FIG. 5, when the work W needs to be mounted at the same position as shown in FIG. 6, that is, on the side of the main bearing, the center of gravity of the moving body composed of the main bearings 320a and 320b and the work W is positioned. However, the holder 420d and the endless belt 3
The joint portion 11 is shifted in the left-right direction in the figure. Therefore, especially when the mass of the work W is a size that cannot be ignored with respect to the mass of the main bearing, and when the acceleration / deceleration G is large, such as when the workpiece W suddenly stops, the main bearings 320a, 320
The moment force received by b becomes excessive, and in some cases, the guide rails 304a and 304b and the main bearings 320a and 3
This may cause sliding contact with 20b, leading to shortened bearing life, seizure, dust generation, and the like.

On the other hand, in the configuration of FIG.
The joint between 0d ′ and the endless belt 311 is connected to the main bearing 320.
By shifting δ to the left in FIG. 6 from the axes of the a and 320b, the center of gravity of the moving body composed of the main bearings 320a and 320b and the work W, and the joint between the holder 420d and the endless belt 311 can be substantially omitted. Can be matched (including perfect match). Therefore, at the time of sudden acceleration / deceleration, the moment force received by the main bearings 320a, 320b is reduced, and the guide rails 304a, 304b and the main bearing 320 are reduced.
By suppressing the sliding contact with a and 320b, it is possible to prevent shortening of the life of the bearing, seizure, dust generation and the like.

When the inventor conducted a test with the work W mounted as shown in FIG. 6 while changing the acceleration / deceleration G, the acceleration / deceleration can be increased by about 30% with respect to the configuration of FIG. Was confirmed by experiment. Evaluation is guide rail 3
The presence or absence of sliding contact between 04a, 304b and the main bearings 320a, 320b was determined by observing whether graphite of the main bearings 320a, 320b adhered to the guide rails 304a, 304b. The effect of shifting the joint portion between the holder 420d ′ and the endless belt 311 from the axis of the main bearings 320a and 320b by δ to the left in FIG. 6 was confirmed.

In the structure of FIG. 6, the main bearing 320
It is preferable that the position of the center of gravity of the moving body including a, 320b, the work W, and the like and the joint portion of the holder 420d and the endless belt 311 be substantially matched (including completely matched), but depending on the mass of the work W, the shift amount δ Is increased, the bending of the holder 420d ′ is decreased, and the function of absorbing the vibration in the vertical direction of the endless belt 311 as described above in FIG. 6 is considered to be weakened. The position of the center of gravity and the joint between the holder 420d and the endless belt 311 may be offset to some extent. If the pulley diameter can be increased because the motor has a sufficient capacity, the holder 430 can be used in the same manner as the configuration of FIG.
The joint between d ′ and the endless belt 311 is connected to the counter bearing 3
The axes of the counter bearings 330a and 330b may be aligned with each other, thereby reducing the moment force of the counter bearings 330a and 330b.

Also, in the case of the first embodiment, the endless bearings 320a, 320b, the housing 320c, and the endless portion of the work W attached to the side surfaces of the housing 320c are substantially aligned with the endless center of gravity. By fixing the belt 331 to the housing 320c,
The same effect can be obtained.

Although the present invention has been described above with reference to the embodiments, the present invention should not be construed as being limited to the above embodiments, and it goes without saying that appropriate modifications and improvements are possible. is there. For example, the main bearing and the counter bearing are
In addition to the air bearing, various modes such as a rolling bearing and a sliding bearing are possible. As described above, as the air bearing, the porous static pressure gas bearing used in the embodiment is preferable because of its high load capacity, but of course, other types such as an orifice type may be used. The guide rail may be porous. further,
In the embodiment, the pulleys and the endless belts have teeth that are particularly suitable for high-speed applications, but other types such as flat belts may be used depending on the applications. The guide rail and the counter guide rail may be three or more.

[0034]

According to the actuator of the present invention, the drive pulley rotatably driven by the drive device, the driven pulley rotatably supported, the drive pulley, and the driven pulley are suspended. A guide bearing device including an endless belt, two or more guide rails, and a main bearing connected to the endless belt and movable along the guide rail, and a counter having the same number and shape as the guide rails. The same mass as the main bearing, which is connected to the guide rail and the endless belt on the opposite side to the side on which the main bearing is attached with the pulleys in between, and is movable along the counter guide rail. And a counter bearing device including the counter bearing, and by moving the main bearing and the counter bearing in opposite directions, acceleration or It is possible to suppress the reaction force of the main bearing that occurs such as when the speed, thereby making it possible to suppress the vibration. Moreover, since the guide rails and the counter guide rails have the same number of two or more and the same shape, the main bearing and the counter bearing can be stably maintained even when the endless belt is transferred at high speed. I can support you. Since the main bearing and the counter bearing have the same mass, the main bearing is generated when the work is not attached to the main bearing or when the endless belt is operated at high speed during acceleration or deceleration. The reaction force of can be suppressed.

[Brief description of drawings]

FIG. 1 is a front view showing a linear guide bearing device 300 including an actuator according to a first embodiment.

2 is a top view showing a linear guide bearing device 300. FIG.

3 is a side view showing a linear guide bearing device 300. FIG.

FIG. 4 is a front view showing a linear guide bearing device 400 including an actuator according to a second embodiment.

5 is a diagram of the configuration of FIG. 4 taken along the line VV and viewed in the direction of the arrow.

FIG. 6 is a view similar to FIG. 5, showing a modified example of the linear guide bearing device.

FIG. 7 (a) is a perspective view showing a linear guide bearing device 100 according to a conventional technique, and FIG. 7 (b) is a sectional view taken along line VIIB-VIIB of FIG. It is a figure.

[Explanation of symbols]

300,400 Linear guide bearing device 301 base 304a, 304b Guide rail 320a, 320b Main bearing 330a, 330b Counter bearing 331a, 331b Counter guide rail 320c housing 420c, 430c leaf spring 420d, 420d '430d, 430d' holder

Continued front page    (72) Inventor Jun Takahashi             78 Toba-cho, Maebashi-shi, Gunma Nippon Seiko Co., Ltd.             In the company F term (reference) 3J104 AA52 AA63 AA70 AA76 AA79                       BA72 CA24 CA34 DA02 EA10

Claims (3)

[Claims] 1. A drive pulley rotatably driven by a drive device, a driven pulley rotatably supported, an endless belt stretched between the drive pulley and the driven pulley, and two or more. A guide bearing device including a guide rail and a main bearing connected to the endless belt and movable along the guide rail, a counter guide rail having the same number and shape as the guide rail, and the endless belt. On the other hand, a counter provided with a counter bearing having the same mass as that of the main bearing, which is connected on the opposite side of the side where the main bearing is attached with the both pulleys sandwiched therebetween and is movable along the counter guide rail. A bearing device, and an actuator. 2. The actuator according to claim 1, wherein the endless belt is connected to the main bearing and the counter bearing via a leaf spring. 3. The fixed position of the endless belt connected to the main bearing is the position of the entire center of gravity of the movable portion of the guide bearing device and the transported object from the axis of the main bearing. The actuator according to claim 1 or 2, wherein the actuators are close to each other and are offset.