JPH0719872A - Rotation driver for survey equipment - Google Patents

Abstract

PURPOSE:To improve the positioning accuracy of a rotation driver for survey equipment. CONSTITUTION:On the axis 4 of movable part, a follower gear 17 is provided and a slide base plate 15 capable of sliding in the perpendicular direction to the axis is also provided. Another gear 20 is placed on the slide base plate 15 so as to gear to the follower gear 17 and the gear 20 is made movable with a motor 8. At the same time, the slide base plate 15 is pushed to the direction the gear 20 is gearing with the follower gear 17 and necessary gearing force is given between the gear 20 and the follower gear 17 to suppress the backrush and enable accurately positioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive device for a surveying instrument.

[0002]

2. Description of the Related Art In order to adjust the collimation direction of a telescope provided in a surveying instrument, the surveying instrument is equipped with a rotary drive device for rotating a movable part including the telescope.

In recent years, a rotary drive device for driving a movable part by a servo motor has become widespread, and FIGS. 5 and 6 show a conventional rotary drive device for a surveying instrument.

In the figure, 1 is a movable part provided with a telescope and the like, 2 is a suspension part for rotatably supporting the movable part 1, and a rotation drive device 3 is housed in the suspension part 2. Has been done.

A shaft portion 4 and a shaft portion 5 are provided at both ends of the movable portion 1, and a rotary drive unit 3 is connected to the one shaft portion 4, and the rotation angle of the movable portion 1 is connected to the shaft portion 5. An encoder 6 for detecting is provided.

The rotation driving device 3 will be described.

A motor 8 is provided on the frame 2 via a support base 7 in parallel with the rotation axis of the movable part 1, and a drive gear 9 is fitted to the output shaft of the motor 8. A floating shaft 10 is rotatably provided on the suspension part 2, and a large-diameter reduction gear 11 and a small-diameter reduction gear 12 are fixed to the floating shaft 10, and the large-diameter reduction gear 11 meshes with the drive gear 9. ing.
A driven gear 13 having a diameter larger than that of the small-diameter reduction gear 12 is fitted on the shaft portion 4, the driven gear 13 meshes with the small-diameter reduction gear 12, and the rotation of the drive gear 9 is caused by the rotation of the large-diameter reduction gear 11. The small-diameter reduction gear 12 and the driven gear 13 reduce the speed, and the speed is transmitted to the movable portion 1.

Thus, the movable portion 1 can be rotated by a required angle by driving the motor 8.

[0009]

As described above, the rotation driving device of the surveying instrument transmits the rotation of the motor 8 to the movable portion 1 via the gear train. In order to accurately transmit the rotation of the motor 8 to the movable portion 1 and perform highly accurate positioning, it is preferable that the backlash between the gears of the gear train is as small as possible, but in an actual gear, pitch error, tooth profile error, The runout of the tooth space and the error in the tooth trace direction are unavoidable in manufacturing the gear, and some backlash between the gears must be allowed in order to rotate the gear smoothly. Therefore, there is a limit in improving the positioning accuracy of the movable part 1 in the conventional rotation drive device of the surveying instrument.

In view of the above situation, the present invention eliminates the backlash of the gear train between the motor and the movable portion and improves the positioning accuracy of the movable portion.

[0011]

According to the present invention, a driven gear is provided on a shaft portion of a movable portion, and a slide substrate is provided on the shaft portion so as to be swingable in a direction orthogonal to an axis of the shaft portion. At least another gear that meshes with the driven gear is provided on the slide substrate, the other gear can be driven by a motor, and the slide substrate is biased in a direction in which the other gear meshes with the driven gear. It is a feature.

[0012]

The other gear is swingably supported with respect to the driven gear, and a required meshing force is applied between the driven gears, so that backlash is suppressed and high-precision positioning is possible.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, the same components as those shown in FIGS. 5 and 6 are designated by the same reference numerals, and the description thereof will be omitted.

A slide substrate 15 is loosely fitted on the shaft portion 4 of the movable portion 1, and the slide substrate 15 is held by a pair of flanges 16 fixed to the shaft portion 4, and the slide substrate 15 is provided with the shaft center of the shaft portion 4. The flange 16 has a guiding function in the sliding direction of the slide substrate 15, and suppresses the fluctuation of the slide substrate 15.
A worm wheel 17 is fixed as a driven gear of the shaft portion 4.

The shaft support block 1 is mounted on the slide substrate 15.
8, the driven shaft 19 is rotatably provided, the driven shaft 19 is formed with a worm 20, and the worm 20 is meshed with the worm wheel 17.
One end of the driven shaft 19 is projected from the shaft support block 18, and a driven pulley 21 is fixed to the protruding end. Motor 8
Is arranged on the opposite side of the worm wheel 17 from the shaft support block 18, and is attached to the slide substrate 15. A drive pulley 22 is fitted on the output shaft of the motor 8, and a belt 23 is wound around the drive pulley 22 and the driven pulley 21.

A driven pulley 21 of the shaft support block 18
The pivot shaft 24 is fixed to the opposite side. The pivot shaft 24 is concentric with the driven shaft 19, and has a spherical surface portion 25 and a spring guide 26 further extending from the spherical surface portion 25 and having a flange at the tip, as shown in FIG. A pivot seat 27 is provided on the inner wall of the suspension unit 2 at a position facing the pivot shaft 24. The spherical portion 25 is attached to the pivot seat 27.
Is formed and a spring holding hole 29 into which the spring guide 26 is loosely inserted is formed.

A spring 30 is provided in the spring holding hole 29.
3, and the spring 30 urges the pivot shaft 24 to the right in FIG. 3 and pushes the spherical surface portion 25 against the conical concave surface 28. Thus, the slide substrate 15 is swingably supported around the center of the spherical portion 25, and the motor 8, the shaft support block 18, etc. provided on the slide substrate 15 are driven except for the worm wheel 17. The parts swing together.

A tongue piece 31 is formed at the lower end of the slide base plate 15, a rocking pin 32 is provided upright on the tongue piece 31, and a fixing pin 33 is made to face the rocking part 2 to the rocking pin 32. A backlash prevention spring 34 is hung between the fixed pin 33 and the swing pin 32 so as to stand upright. The backlash prevention spring 34 urges the slide substrate 15 in the counterclockwise direction in FIG. 2, that is, in the direction in which the worm 20 is pressed against the worm wheel 17.

The operation will be described below.

As described above, since the slide substrate 15 can swing about the spherical portion 25, and the slide substrate 15 is biased in the counterclockwise direction by the backlash restraining spring 34, A required meshing force is applied between the worm 20 and the worm wheel 17.

The motor 8 is driven to drive the drive pulley 2
When the worm wheel 1 is rotated, the worm 20 is rotated through the belt 23 and the driven pulley 21, and the worm 20 and the worm wheel 17 are decelerated to rotate the worm wheel 1.
7 is rotated, and further, the movable portion 1 is rotated via the shaft portion 4. Since a required meshing force is applied between the worm wheel 17 and the worm 20, backlash between the worm wheel 17 and the worm 20 is suppressed, and highly accurate positioning is achieved.

The spherical portion 25 is formed by the spring 30.
Is pressed against the conical concave surface 28 with a required force, there is no backlash between the pivot shaft 24 and the pivot seat 27. Further, the pivot seat 27 may be attached to the pivotally supporting block 18 and the pivot shaft 24 may be provided to the suspension section 2.

Various mechanisms for swingably supporting the slide substrate 15 are conceivable, and another example is shown in FIG.

A pivot block 35 is fixed to the suspension section 2, and the shaft support block 18 is pivotally attached to the pivot block 35 via a swing shaft 36. The swing shaft 36 has an axis parallel to the rotation axis of the worm wheel 17, and the slide substrate 15 is swingably supported about the swing shaft 36. Thus, the backlash prevention spring 34
By urging the slide substrate 15 in the counterclockwise direction, a meshing force that suppresses backlash is applied between the worm wheel 17 and the worm 20.

It should be noted that the backlash prevention spring 34 may be any one as long as it gives a meshing force between the worm wheel 17 and the worm 20, and the mounting position, type, etc. can be changed as appropriate, and the spherical portion 25 is fitted. The concave portion to be formed may be a spherical surface. Further, although the belt and the worm gear are used as the power transmission means in the present embodiment, it goes without saying that a spur gear can be used as in the conventional example, and further, in the present embodiment, the movable portion including the telescope is As described above, it is needless to say that the same can be applied to the frame part that horizontally rotates.

[0027]

As described above, according to the present invention, the backlash of the rotation transmitting portion can be eliminated, high-accuracy positioning can be performed, and proper meshing force can always be applied, so that a machining error can be obtained. With this, the excellent effect of eliminating the problem that smooth rotation transmission cannot be achieved is exhibited.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is an enlarged view of part B in FIG.

FIG. 4 is a view corresponding to an arrow A view of FIG. 1 showing another embodiment.

FIG. 5 is a vertical sectional view showing a conventional example.

6 is a view on arrow C of FIG.

[Explanation of symbols]

 1 Movable part 3 Rotational drive device 4 Shaft part 8 Motor 15 Slide board 17 Worm wheel 20 Worm 24 Pivot shaft 27 Pivot seat 30 Spring 34 Backlash prevention spring

Claims (3)

[Claims] 1. A driven gear is provided on a shaft portion of a movable portion, and a slide substrate is provided on the shaft portion so as to be swingable in a direction orthogonal to an axis of the shaft portion, and at least the driven gear is provided on the slide substrate. A rotation drive of a surveying instrument, characterized in that another gear that meshes with is provided, the other gear can be driven by a motor, and the slide board is biased in a direction in which the other gear meshes with a driven gear. apparatus. 2. A pivot shaft having a spherical surface portion is provided on one of the slide substrate and the fixed portion, and a pivot seat having a concave portion into which the spherical surface portion is fitted is provided on the other of the slide substrate and the fixed portion, The rotary drive device for a surveying instrument according to claim 1, further comprising a spring for pressing the spherical portion against the concave portion. 3. The rotation drive device for a surveying instrument according to claim 1, wherein the slide substrate is swingably supported via a swing shaft parallel to the shaft portion of the movable portion.