JPH068362Y2 - Belt tension adjustment device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a belt tension adjusting device.

BACKGROUND ART As one of power transmission means, there is one that is configured by a plurality of belt wheels and a belt that is wound around each belt wheel and driven. In such power transmission means, the tension of the belt is often adjusted in order to improve the power transmission efficiency and the mountability of the belt to the pulley.

4 (a), (b) and FIG. 5 show an example of a conventional belt tension adjusting device. As shown in the drawing, the driving direction of the belt wheel 3 wound around the two belt wheels 1 and 2:
The support column 4 is arranged so as to extend in a direction perpendicular to S, and is fixed to the support member 5 by a nut 6 at one end portion, in this case, the lower end portion. A rectangular support plate 7 is fixed to the upper end of the column 4 such that its main surface is perpendicular to the central axis of the column. A pair of short support shafts 9 extending parallel to the support column 4 are attached to both ends of the support plate 7 at one end thereof, and a roller 10 abutting on the belt 3 rotates at the other end of the both support shafts. It is provided freely.

The adjustment work by the belt tension adjusting device having the above-described configuration is performed by the following procedure.

First, loosen the nut 6. Next, the column 4 and the support plate 7 are rotated in the direction of arrow Q (see FIG. 4 (a)) to bring the roller 10 into pressure contact with the belt 3 and apply a predetermined tension to the belt. After that, the nut 6 is tightened to fix the support column 4 and the support plate 7 to the support member 5.

In the belt tension adjusting device having such a configuration, the belt 3
A large moment (a moment in the direction opposite to the arrow Q) due to the reaction force applied from the roller 10 to the roller 10 is generated, whereby the nut 6 is easily loosened, and the tension must be adjusted frequently.

6 (a), (b) and FIG. 7 show another example of the conventional belt tension adjusting device. As shown in the figure, the pair of support shafts 12 are arranged so as to sandwich the belt 3 and extend in a direction perpendicular to the belt driving direction S.
And is attached to the support member 5 at the lower end so as to be movable in a direction substantially perpendicular to the extending direction and the belt driving direction. Specifically, the support member 5 has an elongated hole 5 extending in the moving direction of the support shafts 12.
The support shaft 12 is fixed to the support member 5 by a nut 13 screwed to the lower end after the lower end of the support shaft 12 is fitted into the elongated hole. A roller 14 that comes into contact with the belt 3 is rotatably provided at the upper end of the support shaft 12.

The adjustment work by the belt tension adjusting device having this structure is performed in the following procedure.

First, the nut 13 is loosened to make the support shaft 12 movable. Next, the support shaft 12 is moved along the elongated hole 5a to press the roller 14 against the belt 3 and apply tension to the belt 3. After that, the nut 13 is tightened again to fix the support shaft 12 to the support member 5.

In the belt tension adjusting device having the above configuration, the nut 1
No. 3 is difficult to loosen, so it is not necessary to repeat the tension adjustment work many times. However, there is a problem that the support shaft 12 is bent by the reaction force applied from the belt 3 to the roller 14 and the roller 14 is tilted, which adversely affects the driving of the belt 3.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to ensure that the belt tension once adjusted is maintained for a long time and that the belt is smoothly driven. A belt tension adjusting device is provided.

The belt tension adjusting device according to the present invention is disposed so as to sandwich the belts and to extend in a direction substantially perpendicular to the belt driving direction, and is substantially perpendicular to the extending direction and the belt driving direction. A pair of support shafts movably in one direction attached to a predetermined support member at one end, rollers rotatably provided at the other ends of the pair of support shafts and contacting a belt, and a pair of support shafts of the support shafts. It is characterized by comprising first fixing means for fixing the one end portion to the predetermined supporting member and second fixing means for fixing the other end portions of the pair of supporting shafts to each other.

Embodiment An essential part of a multi-joint type robot for assembling parts, which is equipped with a belt tension adjusting device as an embodiment of the present invention, will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1, a servomotor 21 is attached to an upper portion of a head housing 20 of the articulated robot, and a belt wheel 22 is fixed to an output shaft 21a of the servomotor by a set screw 22a. ing. Two spindles 24, 25 are arranged in the head housing 20 in parallel with the output shaft of the servomotor 21, and are rotatably attached to the head housing 20 via ball bearings. 2 for spindle 24
Two belt wheels 26 and 27 are set screws 26a and 27, respectively.
The belt wheel 28 is fixed to the spindle 25 by a set screw 28a. A belt 30 is wound around the belt wheels 22 and 26, and a belt 31 is wound around the belt wheels 27 and 28.

As is clear from FIGS. 2 (a), (b) and FIG. 3, a pair of supports are provided so as to sandwich the belt 31 and extend in a direction perpendicular to the driving direction S of the belt 31. The shafts 33, 34 are arranged and attached to the head housing 20 as a support member at the lower end portion so as to be movable in a direction substantially perpendicular to the extending direction and the belt driving direction. Specifically, the head housing 20 has an elongated hole 20 extending in the moving direction of the support shafts 33 and 34.
a is formed, the lower end of each of the support shafts is fitted into the elongated hole, and then fixed to the head housing 20 by a nut 35 screwed to the lower end.
Rollers 37 and 38 that come into contact with the belt 31 are rotatably provided at the upper ends of the support shafts 33 and 34.

As shown in FIG. 3, one support shaft 33 has a through hole 33a substantially perpendicular to the central axis of the support shaft.
Are formed. The other support shaft 34 has a screw hole 34a that is substantially perpendicular to the central axis of the support shaft.
Are formed. A head bolt 40 is inserted through the through hole 33a of the support shaft 33, and a screw portion of the head bolt is screwed into a screw hole 34a formed in the support shaft 34.

The head bolt 40, the through hole 33 a formed in the support shaft 33, and the screw hole 34 a formed in the support shaft 34 make up the pair of support shafts 33, 34.
Fixing means for fixing the upper end portions of the above to each other. The fixing means is referred to as the second fixing means, while the nut 35 for fixing the lower ends of the support shafts 33 and 34 to the head housing 20 is referred to as the first fixing means.

The first fixing means and the second fixing means, and the support shaft 3
3, 34 and rollers 37, 38 constitute a belt tension adjusting device for adjusting the tension of the belt 31. In the articulated robot, in addition to the belt tension adjusting device, the support shaft 4 shown in FIG.
2, another belt tension adjusting device including a nut 43, a roller 44, a head bolt 45, and the like is provided. The belt tension adjusting device including the support shaft 42 is configured in the same manner as the belt tension adjusting device including the support shafts 33 and 34 described above. Is adjusted.

Next, the tension adjusting work by the belt tension adjusting device including the support shafts 33 and 34 will be briefly described.

First, the nut 35 is loosened to make the lower ends of the support shafts 33 and 34 movable. In this state, the head bolt 40 is rotated to bring the upper ends of the support shafts 33 and 34 closer to each other, and the rollers 37 and 38 are pressed against the belt 31. As a result, a predetermined tension is applied to the belt 31. After that, the lower ends of the support shafts 33 and 34 are brought close to each other to make the shafts parallel to each other. The operation of bringing the lower end portions closer to each other is easily performed by reciprocating the head bolt 40 together with the support shafts 33 and 34 in the central axis direction of the head bolt. After that, nut 35
Are re-tightened to fix the support shafts 33 and 34 to the head housing 20. Thus, the belt tension adjustment is completed.

In the belt tension adjusting device, the support shaft 3
The fixing means (second fixing means) for fixing the upper end portions of the parts 3, 34 to each other are headed bolts 40, through holes 33 a fixed to the support shaft 33, and screws formed on the support shaft 34. Since it is formed by the hole 34a,
The belt tension adjustment work can be performed only from one direction. That is, this adjustment work is completed simply by rotating the head of the headed bolt 40 with a tool such as a spanner. Therefore, the belt tension adjustment work is extremely easy.

Further, in the belt tension adjusting device, the second fixing means is provided below the rollers 37 and 38, but if the support shafts 33 and 34 are appropriately set, the second fixing means is provided.
The fixing means may be provided above the rollers 37 and 38.

Effect of the Invention As described in detail above, in the belt tension adjusting device according to the present invention, the belt tension adjusting device is arranged so as to sandwich the belts and to extend in a direction substantially perpendicular to the belt driving direction. A pair of support shafts attached to a predetermined support member at one end movably in a direction substantially perpendicular to the driving direction, and a belt rotatably provided at the other end of each of the pair of support shafts. A roller that abuts, a first fixing means for fixing the one end of the support shaft to the predetermined support member, and a second fixing means for fixing the other ends of the pair of support shafts to each other. It consists of and.

When a nut that is screwed into the one end of the support shaft is used as the first fixing means, the nut is hard to loosen because of the above-described configuration, and the belt tension once adjusted is maintained for a long period of time. It is done.

Further, by providing the second fixing means, the supporting shaft does not bend due to the reaction force applied from the belt to the roller, and the inclination of the roller is prevented. Therefore, the smooth driving of the belt is guaranteed.

[Brief description of drawings]

FIG. 1 is a front sectional view of an essential part of a multi-joint type robot for assembling parts equipped with a belt tension adjusting device as an embodiment of the present invention, and FIGS. 2 (a), 2 (b) and 3 are the belts. Each of the plan view, front view and perspective view of the tension adjusting device, and FIGS. 4 to 7 are views for explaining a conventional belt tension adjusting device. Description of symbols of main parts 27, 28 ... Belt wheel 31 ... Belt 33, 34 ... Support shaft 33a ... Through hole 34a ... Screw hole 35 ... Nut 37, 38 ... Roller 40 ... Head bolt

Claims (2)

[Scope of utility model registration request] 1. A belt tension adjusting device for adjusting the tension of a belt wound around and driven by a plurality of belt wheels, said belt tensioning device sandwiching said belts with respect to the driving direction of said belts. A pair of support shafts attached to a predetermined support member at one end so as to be movable in a direction substantially perpendicular to the extending direction and the driving direction, A roller rotatably provided at each of the other ends of the pair of support shafts and in contact with the belt; a first fixing means for fixing the one end of the support shaft to the predetermined support member; A belt tension adjusting device comprising: second fixing means for fixing the other ends of the support shaft to each other. 2. The second fixing means includes a through hole formed in one of the pair of support shafts at a right angle to a central axis of the support shaft, and a central axis of the support shaft in the other of the one of the pair of support shafts. 2. The belt according to claim 1, wherein the belt comprises a screw hole formed substantially at a right angle to the screw hole, and a head bolt that is inserted into the through hole and screwed into the screw hole. Tension adjusting device.