JP2003207035A - Rotary stage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove backlash in a rotary stage device using a normal worm gear, etc., for a drive transmission mechanism. <P>SOLUTION: A face plate 1 is fixed on a head end of a main shaft 2. The main shaft 2 is supported on an upper surface of a housing 4 through a bearing 3. The worm gear is stored in the inside of the housing 4, and a worm wheel 5 is fixed on a rear end of the main shaft 2. A shaft 7 of a worm 6 is supported on a side surface of the housing 4 through a bearing 8, and a rear end of the shaft 7 is connected to a servo motor 9. A torsional coil spring 11 is mounted on an end surface of the worm wheel 5. One end of the torsional coil spring 11 is fixed on an end surface of the worm wheel 5, and the other end is fixed on a bottom surface of the housing 7. Rotational torque in the specified direction is constantly made to work on the main shaft 2 by previously giving specified sagging to the torsional coil spring 11. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary stage device used for holding a work and adjusting the rotation angle of the work, and particularly when driving a face plate through a gear mechanism such as a worm gear. The present invention relates to a structure for removing backlash in a drive transmission mechanism.

[0002]

2. Description of the Related Art In the process of connecting a conversion element or the like to the tip of an optical fiber, a rotary stage device is used to match the optical axes and the rotation angles of the two. In the conventional rotary stage device, a worm gear is widely used for the drive transmission mechanism.

FIG. 6 shows an outline of a conventional rotary stage device. The face plate 1 is fixed to the tip of the main shaft 2. Spindle 2
Are supported on the upper surface of the housing 4 via bearings 3. A worm gear is housed inside the housing 4. A worm wheel 5 is fixed to the rear end of the main shaft 2,
A worm 6 is engaged with the worm wheel 5. The shaft 7 of the worm 6 is attached to the housing 4 via a bearing 8.
Is supported on the side of. A servo motor 9 is attached to the outer surface of the side surface of the housing 4. The rear end of the shaft 7 is connected to the servomotor 9. The rotation angle of the face plate 1 is adjusted by controlling the rotation angle of the servo motor 9.

(Problems of Prior Art) In a general worm wheel used in a conventional rotary stage device,
There is a backlash of about 0.05 degree.

In order to ensure smooth operation of the face plate, it is difficult to eliminate backlash with a normal spur gear or worm gear. Backlash in the drive transmission mechanism causes lost motion of the face plate. If there is lost motion on the face plate, the positioning accuracy is reduced, and a dead zone is generated every time the rotation direction is reversed, making centering work difficult, or reducing the efficiency of centering work. Moreover, when an automatic process is set up by a control program, the program is complicated.

As a gear whose backlash can be reduced by assembling and adjusting, there is a multi-lead worm gear, and there is an example in which lost motion is reduced by using this. However, the use of the multiple lead worm complicates the structure and increases the processing cost of the worm, resulting in an increase in manufacturing cost. Further, for the backlash adjustment, a space for assembling and adjusting the worm in the axial direction is required, which increases the size of the device.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems in the conventional rotary stage apparatus as described above, and an object of the present invention is to provide a drive transmission mechanism with an ordinary spur gear and worm gear. It is an object of the present invention to provide a rotary stage device capable of suppressing backlash while using the above.

[0008]

A rotary stage device according to the present invention comprises a main shaft, a face plate fixed to the tip of the main shaft, a drive source, and a plurality of gears, and the movement of the drive source via these gears. In a rotary stage device having a drive transmission mechanism for transmitting to a main shaft, by connecting a torque applying mechanism that always gives a rotational torque in a fixed direction to the main shaft,
Backlash in the drive transmission mechanism is removed.

According to the rotary stage apparatus of the present invention, the torque imparting mechanism always imparts a rotational torque in a fixed direction to the spindle. Therefore, by setting this rotation torque to an appropriate value in advance, only one side of each tooth will always contact in each gear forming the drive transmission mechanism regardless of the rotation direction of the gear. Can be realized. As a result, backlash in the drive transmission mechanism can be eliminated.

Preferably, as the torque applying mechanism,
Use a torsion coil spring. In that case, a torsion coil spring is connected to the rear end of the main shaft, and the torsion coil spring constantly applies a rotational torque in a fixed direction to the main shaft.

When the torsion coil spring is connected to the rear end of the main shaft, it may be directly connected to the rear end of the main shaft, or a gear or disc fixed to the rear end of the main shaft. Alternatively, it may be indirectly connected to the rear end portion of the main shaft via an arm or the like.

Alternatively, the torque applying mechanism may be composed of a drum, a wire and a coil spring. In that case, a drum is fixed to the main shaft, a wire is wound around the drum, a coil spring is connected to the tip of the wire, and the coil spring applies tension to the wire.

In the above structure, a weight may be hung on the tip of the wire instead of the spring, and the weight may be applied to the wire.

In addition, the torque applying mechanism may be composed of a rack and pinion and a spring.
In that case, a pinion is fixed to the main shaft, a spring is connected to the rack, and this spring constantly applies thrust to the rack in a fixed direction.

Alternatively, the torque applying mechanism may be composed of a ball screw and a spring. In that case, a screw shaft is fixed to the rear end of the main shaft, a spring is attached to the nut, and this spring always applies a thrust in a fixed direction to the nut.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a rotary stage device according to the present invention.

The face plate 1 is fixed to the tip of the main shaft 2.
The main shaft 2 is supported on the upper surface of the housing 4 via bearings 3. A worm gear is housed inside the housing 4. A worm wheel 5 is fixed to the rear end of the main shaft 2, and a worm 6 is meshed with the worm wheel 5. The shaft 7 of the worm 6 is supported on the side surface of the housing 4 via a bearing 8. A servo motor 9 is attached to the outer surface of the side surface of the housing 4. The rear end of the shaft 7 is connected to the servomotor 9. The rotation angle of the face plate 1 is adjusted by controlling the rotation angle of the servo motor 9.

In this example, since the rotating torque is always applied to the main shaft 2 in a constant direction, the torsion coil spring 1 is applied to the main shaft 2.
1 is connected as follows. The torsion coil spring 11 is housed in a hole 12 provided at the center of the bottom surface of the housing 4. Torsion coil spring 11
One end is fixed to a mounting hole 13 provided in the end surface of the worm wheel 5, and the other end is fixed to a mounting hole 14 provided in the bottom of the hole 12.

The torsion coil spring 11 is assembled in a state in which an initial deflection is given in advance, or after being assembled in a free state, the worm 6 is rotated to give a predetermined deflection to the torsion coil spring 11 so that the spindle 2 is attached. It is possible to always give a rotational torque in a fixed direction.

At this time, the initial deflection given to the torsion coil spring 11 in advance is set to be sufficiently larger than the operating range of the face plate 1, so that the above-mentioned rotational torque changes based on the angle change of the face plate 1 during operation. Can be kept small.

Further, the spring constant of the torsion coil spring 11 is such that the rotational torque by the torsion coil spring 11 is retained on the face plate 1 even when the bending of the torsion coil spring 11 is minimized due to the angle change of the face plate 1 during operation. It is set to exceed the sum of the anti-torque torque transmitted from the workpiece and the rotational resistance torque under no load.

When connecting the conversion element to the tip of the optical fiber, the conversion element is held on the face plate 1. In this case, the reaction torque transmitted to the face plate during alignment work is small, and almost no impact torque is generated. Therefore, use a relatively small torsion coil spring to eliminate backlash in the drive transmission mechanism. You can

FIG. 2 shows another example of the rotary stage device according to the present invention.

In this example, the drum 21, the wire 22 and the coil spring 23 are used in order to constantly apply a rotational torque in a fixed direction to the main shaft 2. That is, the drum 21 is fixed to the rear end of the main shaft 2, and the wire 22 is wound around the drum 21. One end of the wire 22 is fixed to the outer circumference of the drum 21, and the other end is connected to one end of the coil spring 23. The other end of the coil spring 23 is fixed to the housing 4.

Tension is applied to the wire 22 by preliminarily providing the coil spring 23 with bending in the pulling direction. As a result, a rotational torque in a fixed direction corresponding to “wire tension × drum radius” can be applied to the spindle 2.

FIG. 3 shows another example of the rotary stage device according to the present invention.

In this example, the drum 21, the wire 22 and the weight 24 are used in order to constantly apply a rotational torque in a fixed direction to the main shaft 2. That is, the drum 21 is fixed to the rear end of the main shaft 2, and the wire 22 is wound around the drum 21. One end of the wire 22 is fixed to the outer circumference of the drum 21, and a weight 24 is attached to the other end. By applying tension to the wire 22 by the weight 24, a rotational torque in a fixed direction can be applied to the main shaft 2.

FIG. 4 shows another example of the rotary stage device according to the present invention.

In this example, the rack 26, the pinion 25, and the spring 23 are used in order to constantly apply a rotational torque in a fixed direction to the main shaft 2. That is, the pinion 25 is fixed to the rear end of the main shaft 2, and the rack 26 is attached to the pinion 25. A spring 23 is connected to the right end of the rack 26, and the right end of the spring 23 is fixed to the housing 4. By constantly applying a thrust force to the rack 26 with this spring 23,
A rotation torque in a fixed direction can be applied to the main shaft 2.

FIG. 5 shows another example of the rotary stage device according to the present invention.

In this example, a ball screw (screw shaft 27, nut 28) and a spring 29 are used in order to always apply a rotational torque in a fixed direction to the main shaft 2. That is, the screw shaft 27, into which the nut 28 is screwed, is fixed to the rear end portion of the main shaft 2, and the spring 29 is attached to the rear end surface of the nut 28. By constantly applying a thrust in a constant direction to the nut 28 with the spring 29, a rotation torque in a constant direction can be applied to the main shaft 2.

[0032]

According to the rotary stage device of the present invention, by applying a rotational torque in a fixed direction to the main shaft that supports the face plate, a relatively simple structure using a general worm gear or the like can be used in the drive transmission mechanism. Backlash can be eliminated. As a result, the positioning accuracy of the device is improved, and lost motion is reduced, so that the efficiency of centering work is improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a rotary stage device according to the present invention.

FIG. 2 is a diagram showing another example of a rotary stage device according to the present invention.

FIG. 3 is a diagram showing another example of the rotary stage device according to the present invention.

FIG. 4 is a diagram showing another example of the rotary stage device according to the present invention.

FIG. 5 is a diagram showing another example of the rotary stage device according to the present invention.

FIG. 6 is a diagram showing an example of a conventional rotary stage device.

[Explanation of symbols]

1 ... face plate, 2 ... spindle, 3 ... Bearing, 4 ... housing, 5 ... worm wheel, 6 ... worm, 7 ... axis, 8 ... Bearing, 9 ... Servo motor, 11 ... torsion coil spring, 12 ... hole, 13, 14 ... Mounting holes, 21 ... drums 22 ... wire, 23 ... Coil spring, 24 ... weight, 25 ... Pinion, 26 ... rack, 27 ... Ball screw screw shaft, 28: Ball screw nut, 29 ... Spring.

Claims (6)

[Claims] 1. A main shaft, a face plate fixed to the tip of the main shaft, a drive source, and a plurality of gears, and a drive transmission mechanism for transmitting the motion of the drive source to the main shaft via these gears. The rotary stage device according to claim 1, wherein a backlash in the drive transmission mechanism is removed by connecting a torque applying mechanism that constantly applies a rotational torque in a fixed direction to the main shaft. 2. The torque applying mechanism includes a torsion coil spring, a torsion coil spring is connected to a rear end portion of the main shaft, and the torsion coil spring constantly applies a rotational torque in a fixed direction to the main shaft. The rotary stage device according to claim 1. 3. The torque applying mechanism includes a drum, a wire, and a coil spring, the drum is fixed to the main shaft, the wire is wound around the drum, and the coil spring is connected to the tip of the wire. The rotary stage device according to claim 1, wherein a tension is applied. 4. The torque applying mechanism includes a drum, a wire and a weight, the drum is fixed to the main shaft, the wire is wound around the drum, the weight is attached to the tip of the wire, and the weight is tensioned with the weight. The rotary stage device according to claim 1, wherein: 5. The torque applying mechanism comprises a rack and pinion and a spring, the pinion is fixed to the main shaft, the spring is connected to the rack, and the spring applies a thrust in a constant direction to the rack at all times. The rotary stage device according to claim 1. 6. The torque applying mechanism includes a ball screw and a spring, a screw shaft is fixed to a rear end portion of the main shaft, a spring is attached to a nut, and the spring applies a thrust in a constant direction to the nut at all times. The rotary stage apparatus according to claim 1, wherein the rotary stage apparatus is a rotary stage apparatus.