JPH03294192A - Backrush removing device - Google Patents

Abstract

PURPOSE:To remove backrush easily and surely, by freely moving the tooth part of an intermediate gear in multi-directions. CONSTITUTION:The tooth part of an intermediate gear becomes movable on the circular arc which makes the eccentric quantities of a support part 21 and an intermediate support part 150 as radii, with the rotary center shaft 106 of the support part 21 as the center. The intermediate gear is moved in the direction orthogonal with the straight line connecting the rotary center shaft of a driving gear and that of the gear to be driven by this movement. In the case of an oblong hole being formed on a frame, also, the support part 21 becomes movable in the longitudinal direction of the oblong hole, and in the case of the oblong hole being formed on the intermediate support part 150, it becomes movable in the longitudinal direction of the oblong hole to the support part 21. So the intermediate gear is moved in the direction parallel to the straight line connecting the rotary center shaft of the driving gear and that of the gear to be driven.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a backlash removal device that removes backlash between a driving gear and an intermediate gear and between a driven gear and an intermediate gear.

<Prior art> Conventionally, as a backlash removal device, the
169250, of a pair of gears that mesh with each other, one is made by overlapping two gears of the same shape and size,
Due to the repulsive force of the elastic body provided on these two gears, 2
Some gears eliminate backlash by applying torque in opposite directions to two gears and sandwiching or pushing the tooth flanks of the other gear apart.

In addition, as shown in Japanese Utility Model Application No. 59-54251, the distance between the two axes is adjusted by guiding the housing member that supports the rotating shaft of one of a pair of gears that mesh with each other through a linear sliding guide. There is something to do.

<Problems to be solved by the invention> However, in the case of a structure in which two gears are overlapped as described above, the face width is approximately twice, making it difficult to convert into a compound.
Adjustment of the elastic member is also difficult. In addition, in the case where the housing member is guided by a linear sliding guide to adjust the distance between the two axes, it is difficult to ensure smoothness when the guide is moved, and it takes time to adjust. . Because the direction of guidance is one-sided, it is difficult to completely eliminate backlash, and it is also difficult to support the rotating shaft at both ends, which reduces the rigidity of the entire device. .

The present invention has been developed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a backlash removal device that can adjust the hashish crash in multiple directions and easily remove the backlash. purpose.

Means for Solving the Problems> The articulated robot of the present invention was made to solve the above-mentioned problems, and includes a driving gear, a driven gear supported by a frame, and a drive gear and a driven gear supported by a frame. A device for removing backlash between the driving gear and the intermediate gear and between the driven gear and the intermediate gear of a gear mechanism consisting of intermediate gears meshing with both gears, wherein the support shaft of the intermediate gear is The intermediate support part includes an intermediate support part that rotatably supports the tooth part of the intermediate gear via a bearing, and a support part that supports the intermediate support part so as to be movable around an axis eccentric from the central axis of the intermediate support part. The intermediate gear is arranged so that the central axis of the intermediate support section does not lie on a straight line connecting the rotation center axis of the driving gear and the rotation center axis of the driven gear, and at least either the frame or the intermediate support section On one side, a long elongated hole is formed in a direction parallel to a straight line connecting the rotational center axis of the drive gear and the rotational center axis of the driven gear, and the support portion moves in the longitudinal direction of the elongated hole with respect to this elongated hole. installed as possible.

Effects> With the above configuration, the tooth portion of the intermediate gear can move on a circular arc having a radius equal to the eccentricity of the support portion and the intermediate support portion, with the rotation center axis of the support portion as the center.

This movement allows the intermediate gear to move in a direction perpendicular to a straight line connecting the rotation center axis of the drive gear and the rotation center axis of the driven gear. In addition, when a long hole is formed in the frame, the support part can be moved in the longitudinal direction of the long hole, and when a long hole is formed in the intermediate support part, the intermediate support part can be moved in the longitudinal direction of the long hole relative to the support part. It becomes possible to move to. Therefore, the intermediate gear can be moved in a direction parallel to a straight line connecting the rotation center axis of the driving gear and the rotation center axis of the driven gear. Two directions, one perpendicular to the straight line connecting the rotation center axis of the drive gear and the rotation center axis of the driven gear, and the other parallel to the line.
By combining the two directions of movement and allowing the teeth of the intermediate gear to move freely, the intermediate gear can be pressed against both the driving gear and the driven gear, and backlash is eliminated.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. 1st
As shown in the figures and FIG. 2, a swivel base 12 is rotatably supported on a support base 10 around a vertical first axis 100, and this swivel base 12 is driven by a single-axis servo motor attached to the swivel base 12 itself. 13 for rotational driving.

The swivel base 12 has a second arm whose base end portion is horizontal.
It is rotatably supported by a first pivot shaft 5 centered on an axis 101, and swing-driven by a two-axis servo motor 16 attached to the turning metalwork 2 via a circuit speed reduction mechanism. . The swivel base 12 also includes a first swivel shaft 5.
A first gear 82 rotatable about the center is supported. A second pivot shaft 6 centered on a third axis 102 parallel to the second axis "01" is supported at the tip of the first arm 14. A second arm 15 is fixed to the second pivot shaft 6 so as to be swingable about a third axis 102 . Further, the second pivot shaft 6 has a second arm rotatable with respect to the first arm 14.
Gear 83 is fixed. First gear 82 and second gear 8
Between 3 is the 2nd axis! 101 and three idle gears 60a, 6 whose rotation center axis is parallel to the third axis 102.
0b.

60c meshes with these idle gears 60a, 60b, 6
The rotation center axis of 0c is the second axis 101 and the third axis 1
From the straight line connecting 02, idle gears 60a, 60b, 60c
They are supported by the first arm 4 while being offset in opposite directions alternately in this order.

A three-axis servo motor 17 is fixed to the swivel base 12 for swinging the second arm 15 by rotating a first gear 82 via a speed reduction mechanism 36 made up of several auxiliary gears. A twist wrist 63 is rotatably supported at the tip of the second arm 15 about a fourth axis 103 at the center of the second arm 15, and is driven to rotate by a four-axis motor of the circuit. . twist list 63
Above are Beni'Tristro 1 and Swivel Wrist 6.
5 are sequentially rotatably supported and driven to turn by a 5-axis servo motor 50 and a 6-axis servo motor 66, respectively.

A balance cylinder 37 is provided between the swivel base 12 and the second arm 15.

As shown in FIGS. 3(a) and 3(b), an idle gear 60a.

The support shafts 67a, 67b, 67c of 60b, 60c are the first
It is supported between the inner frame 68 and outer frame 690 of the arm 15.

The attachment part of the support shaft 67a on the inner frame 68 is attached to the second gear 83 and the idler gear 60b, which are adjacent to the idler gear 60a.
An elongated hole 70 is formed so as to be movable to eliminate backlash with the support shaft 67a, and a rectangular protrusion 7X formed on the support shaft 67a is fitted into the elongated hole 70 so as to be slidable in the longitudinal direction. In addition, in order to insert a bolt 72 for supporting the support shaft 67a between the inner frame 68 and the outer frame 69, a long loose fit hole 73 is formed in the support shaft 67a in the same direction as the elongated hole 70. has been done. The tooth portion 20a of the idler gear 60a is attached to the outside of the support shaft 67a via a bearing 74.
is installed.

The support shaft 67b includes an intermediate support portion 151) that supports the tooth portion 20b via a bearing 75, and a rotation center axis 106 provided at a position eccentric from the center axis 107 of the intermediate support portion 150. It consists of a support part 21 that rotatably supports. The mounting portions of the inner frame 68 and outer frame 69 of the support portion 21 are formed with elongated holes 78 extending in a direction parallel to a straight line connecting the rotational axes of the adjacent idler gears 6a and 60c. Further, the support shaft 67b is supported between the inner frame 68 and the outer frame 69 by four bolts 79. A loose fit hole 81 is formed in the support shaft 67b so that the support shaft 67b can eccentrically rotate around the rotation center axis 106 and move in the longitudinal direction of the elongated hole 78 by loosening the bolt 79.

The attachment portion of the support shaft 67c on the inner frame 68 is connected to the first gear 82 and the idler gear 60b to which the idler gear 60c is adjacent.
An elongated hole 84 is formed so as to be movable to eliminate backlash with the support shaft 67c, and a rectangular protrusion 85 formed on the support shaft 67c is slidably fitted in the elongated hole 84 in the longitudinal direction. Further, in order to insert a bolt 87 for supporting the support shaft 67c between the inner frame 68 and the outer frame 690, a loose fitting hole 86 that is long in the same direction as the elongated hole 84 is formed in the support shaft 67c. A tooth portion 20c of an idler gear 60C is attached to the outside of the support shaft 67C via a bearing 88.

Next, in order to explain the operation of the articulated robot of this embodiment, the explanation will be made using the models shown in FIGS. 4(a) and 4(b). In the model shown in FIG. 4, there is only one idle gear compared to the three idle gears in the embodiment.

The number of idle gears in the embodiment is determined by matching the rotating directions of the first gear 82 on the driving side and the second gear 83 on the driven side, and making the gears compact in the elongated first arm 14. There are three gears in consideration of the arrangement, and if only the movement of the robot is considered, the first gear 82 and the second gear 82
Since it is sufficient to match the rotating directions of the gears 83, any number of idle gears may be used as long as the number is an odd number, and in the model, one is simply used. When the two-axis servo motor 16 is driven to swing the first arm 14 while the three-axis servo motor 17 is not driven and the first gear 82 is fixed, this gear mechanism moves the first gear 82 to the sun. It becomes a planetary gear device with a planetary chain as gears. Since the first gear 82 and the second gear 83 are the same gear and rotate in the same direction, the rotation ratio e of the second gear 83 to the first gear 82 is 1. Here, the rotation of the first gear 820 is nl, the rotation of the second gear 83 is n2, and the rotation of the second gear 83 is n1.
When the rotation of the arm is N, the rotation ratio e is expressed as follows.

e= (n2-N)/(nl-N) In the above equation, e=1 and the first gear 82 is fixed, and since it is a train, n1=o. Therefore, the above formula is obtained. In other words, when the first arm J4 is swung while the first gear 82 is fixed, the second gear 83 moves as shown in FIG. 4(b).
Although it revolves around the first gear 82, the second gear 83 itself does not rotate, and the direction of the arrow A drawn on the second gear 83 remains unchanged. Therefore, the posture of the second arm 15 to which the second gear 83 is fixed remains unchanged as seen from the outside of the robot. This property is equivalent to the property of the parallel link mechanism shown in FIGS. 8(a) and 8(b).

In addition to the above-mentioned characteristics, the articulated robot of this embodiment drives the three-axis servo motor 17 to rotate the first gear 82, and rotates the second gear 82 via the idle gears 60a, 60b, and 60C.
3 can be rotated in the same direction as the first gear 82,
This allows the second arm 15 to swing about 330 degrees about the third axis 102. Therefore, when both the first arm 14 and the second arm 5 are driven, the multi-jointed robot has a wide working area in both the front and rear and above, as shown in FIG.

As described above, the articulated robot of this embodiment does not drive the 3-axis servo motor 17, but rather drives the 2-axis servo motor 16 to swing the first arm 14.
Since the posture of the robot 5 as seen from the outside remains unchanged, it is easy to control the arm.
Not only does it have the same advantages as the parallel link type vertical articulated robot in that the axis servo motor 17 can be installed on the rotating base 12 and the load on the two-axis servo motor 16 can be reduced, but it also has the same advantages as the parallel link type vertical articulated robot. It has a large working area both front and rear and above. Furthermore, the articulated robot of this embodiment has a feature that it has a large payload capacity because it is composed of highly rigid elements such as gears.

Next, the pack runche removing device shown in FIGS. 3(a) and 3(t)) will be explained. Support shafts 67a, 67b.

Loosen bolts 72, 79.87 that fix 67c,
The support shafts 67a, 67b, and 67C are movable due to the loose fitting holes 73°81.86 into which each bolt is fitted. That is, the idle gear 60a fixed to the support shaft 67a is movable along the elongated hole 70. Similarly, the support shaft 6
The idler gear 60c fixed to 7c runs along the elongated hole 84,
It becomes possible to move. As shown in the model in FIG. 6(a), the center axis 107 of the intermediate support portion 50 and the rotation center axis 106 of the support portion 21 are eccentric. For this reason, the idle gear 60
The central axis 107, which is the rotation center of the bm tooth portion 20b, is movable on an arc having a radius equal to the amount of eccentricity around the rotation center axis 106 of the support portion 210. This movement mainly moves the idle gear 60b to the rotation center axis 10 of the idle gears 60a and 60c.
It moves in the direction perpendicular to the straight line connecting 8,109,
This movement is referred to as a first movement 35. Further, the support shaft 67b is connected to the inner frame 68 and the outer frame 69 by the elongated hole 78.
Since the support shaft 67b is supported between the slots 78 and 78, the support shaft 67b is movable in the longitudinal direction of the elongated hole 78, that is, in a direction parallel to the straight line connecting the rotational axes 108 and 109 of the idler gears 60a and 60C. Therefore, the tooth portion 20b is also movable in the same direction, and this movement is referred to as a second movement 36. Therefore, idle gear 60b
The tooth portion 20b can be freely moved by combining the first movement 35 and the second movement 36. By utilizing this movement, if the idler gear 60b is pressed against the idler gears 60a and 60c so that there is no backlash, this force will cause
The idle gears 60a, 60c move along the elongated holes 70°84. As a result, the idle gear 60a meshes with the second gear 83 without backlash. Moreover, the idle gear 60c is
It meshes with the first gear 82 without backlash. Therefore,
The backlash removal device of this embodiment has an idle gear 60b.
is pressed against the idle gears 60a and 60c, and the idle gear 60b is pressed against the idle gears 60a and 60c.
and 60a and between idler gears 60b and 60c.
Backlash between Oa and the second gear 83 and between the idle gear 60c and the first gear 82 can also be eliminated.

As mentioned above, in order to realize the motion of the articulated robot of this embodiment, the number of idle gears may be any odd number. In addition, in this embodiment, three idle gears 60a, 60b, 60 are provided to eliminate backlash.
The rotation center axis of c is from the straight line connecting the rotation center axes of the first gear 82 and the second gear 83, and the idle gears 60a, 60b, 60.
The banklash remover is attached to the idle gear 60b by being alternately offset in the opposite direction in the order of As long as it is offset from the straight line connecting the central axes, the backlash removal device of this embodiment works effectively.

Therefore, as shown in FIG. 7(a), the number of idle gears is one, and the rotation center axis of this idle gear 60 is connected to the first gear 82 and the second gear.
A backlash remover is attached to the idler gear 60 offset from the straight line connecting the rotation center axis of the gear 83, or three idler gears 60 as shown in Fig. 7 Φ) and (C).
a, 60b, and 60c, the rotation center axis of the idle gear 60b is arranged on a straight line connecting the rotation center axes of the first gear 82 and the second gear 83, and the rotation center axes of the idle gears 60a, 60c are offset from this straight line. and idle gears 60a, 60c
A backlash removal device may be attached to the backlash remover.

Here, in FIGS. 7(b) and 7(C), (b) is the idle gear 60a.

60c is offset in the opposite direction, and (C) is the idle gear 6Q.
a and 60c are offset in the same direction.

Further, in the backlash removal device of this embodiment, the support portion 2
1, an elongated hole 78 in a direction parallel to a straight line connecting the rotation center axes of adjacent idler gears 60a and 50c is formed in the mounting portions of the inner frame 68 and outer frame 69 of No. 6. As shown in the model in Figure 1), a similar effect can be obtained by providing an elongated hole 160 similar to the elongated hole 78 in the intermediate support portion 150 and passing the support portion 21 through the elongated hole 160. is obtained.

<Effects of the Invention> As described above, the backlash removal device of the present invention has the following effects:
The support shaft of the intermediate gear supports the intermediate support part such as an intermediate support part that rotatably supports the tooth part of the intermediate gear via a bearing, and supports the intermediate support part so as to be movable around an axis eccentric from the central axis of the intermediate support part. The intermediate gear is arranged such that the central axis of the intermediate supporting part does not lie on a straight line connecting the central axis of rotation of the drive gear and the central axis of rotation of the first driven wheel, and A long elongated hole is formed in at least one of the intermediate support parts in a direction parallel to a straight line connecting the rotational center axis of the driving gear and the rotational center axis of the driven gear, and the support part is connected to the elongated hole. 7. Because it is mounted movably in the longitudinal direction of the elongated hole. By freely moving the teeth of the intermediate gear in multiple directions, backlash can be easily and reliably removed. FIGS. 1 to 7 are diagrams showing embodiments of the present invention. Fig. 1 is a side view for explaining the structure of the multi-joint robot of the embodiment, Fig. 2 is a rear view for explaining the structure of the multi-joint robot, Fig. 3 is an enlarged view of the idle gear, and Fig. 4 is a side view for explaining the structure of the multi-joint robot of the embodiment. The figure is a model of the articulated robot of this embodiment, Figure 5 is a diagram showing the working area of the articulated robot of this embodiment, and Figure 6 is a model of the backlash removal device of this embodiment. FIG. 7 is a diagram illustrating a modified example of the present embodiment. FIG. 8 is a model of a parallel link type vertically articulated robot.

20b...Tooth part, 21...Support part, 60°60a,
60b, 60cm--idling gear, 67a.

67b, 67c...Support shaft, 68...Inner frame, 69...Outer frame, 75...Bearing, 7
8.160... Elongated hole, 106... Rotation center axis of support part 21, 107... Center axis of intermediate support frame part 150, 10
8...Rotation center axis of idle gear 6a, ], 09...
Idle gear 60c rotation center shaft, 150... intermediate support part.

Claims (1)

[Claims] In a gear mechanism that includes a driving gear, a driven gear, and an intermediate gear that meshes with both of these two gears, the backlash between the driving gear and the intermediate gear and the backlash between the driven gear and the intermediate gear are A device for removing backlash, wherein the support shaft of the intermediate gear includes an intermediate support part that rotatably supports the teeth of the intermediate gear via a bearing, and an axis that is eccentric from the central axis of the intermediate support part. The intermediate support part is configured such that the central axis of the intermediate support part does not lie on a straight line connecting the rotation center axis of the drive gear and the rotation center axis of the driven gear. an intermediate gear is disposed, and a long elongated hole is formed in at least one of the frame or the intermediate support in a direction parallel to a straight line connecting the rotation center axis of the drive gear and the rotation center axis of the driven gear; A backlash removal device in which the support portion is attached to the elongated hole so as to be movable in the longitudinal direction of the elongated hole.