JPH06249307A - Tensioning device of belt - Google Patents

Abstract

PURPOSE:To provide a tensioning device which maintains the specified tensioning force an endless belt even when vibration or load fluctuation is added to the belt for a long time. CONSTITUTION:An arm 5 in which a tension roller 4 is pivottaly supported rotatably to its one edge and an attaching/fixing part 9 is provided on its other edge, is arranged on a frame 7 between a driving roller 1 and a driven roller 2. A slide pin 11 is hung below the one edge of the arm 5. A sliding groove 12 through which the slide pin 11 moves by sliding, is provided on the upper face of the frame 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for transmitting power from a drive shaft to a driven shaft via an endless belt, and a device for applying tension to the endless belt. .

[0002]

2. Description of the Related Art Generally, in a power transmission device for transmitting the rotation of a drive shaft to a driven shaft through an endless belt, a slight amount is required for assembling the endless belt around a drive roller and a driven roller. A tensioning device is provided to compensate for the slack when the endless belt gradually expands due to its extra dimension or due to long-term use of the endless belt.

For example, Japanese Utility Model Laid-Open No. 52-16486 and Japanese Utility Model Laid-Open No. 61-142951 disclose that the tension between endless belts is adjusted by changing the axial distance between a drive shaft and a driven shaft. Has been done. However, the tension adjusting device of this type has a structure in which at least one of the drive shaft and the driven shaft has to be moved, so that the structure is complicated and the space is easily restricted.

Therefore, as the simplest belt tensioning device, as shown in FIG. 7, a tension roller 4 is provided on the side of an intermediate portion of an endless belt 3 wound between rollers 1 and 2, and the tension roller 4 is used. A method of applying a predetermined tension to the endless belt 3 by pressing the endless belt 3 to bend the belt 3 is generally used.

[0005]

However, in the belt tensioning device using the tension roller 4 of this kind, the tension roller 4 is rotatably supported at one end of the arm 5, and the other end is fixed to the frame 7 by the bolt 6. Since it is fixed by tightening, the tension of the endless belt 3 is applied to the arm 5
When only a large amount of tension is needed to tension the endless belt 3, or when the power transmission transmits vibration or load fluctuation for a long time. In addition, the repeated swinging of the arm 5 may cause loosening in the tightening of the bolt 6, and it may not be possible to apply sufficient tension to the endless belt 3.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems and has an object to perform a stable tension adjustment with a simple structure. In a power transmission device that rotatably supports a driven roller and hangs an endless belt between the rollers to transmit the rotation of the drive roller to the driven roller, a tension roller is rotatably supported at one end. Then, an arm having a mounting and fixing portion at the other end is arranged on the frame between the drive roller and the driven roller, and a slide pin is vertically provided at a lower part on one end side of the arm, A slide groove portion on which the slide pin slides is provided on the upper surface of the frame, and the arm is moved along the slide groove portion through the slide pin to move the table. Deployment rollers at by pressing the endless belt taut those fixed to the frame of the arm in the fixing lug.

[0007]

The arm which pivotally supports the tension roller at one end moves along the slide groove provided on the upper surface of the frame through the slide pin, and presses the tension roller against the endless belt, thereby the endless belt. A predetermined tension is applied to the arm, and the force that acts on the arm by the tension of the endless belt is distributed into a force that presses the inner surface of the slide groove portion by the slide pin and a force that acts on the attachment fixing portion. It

[0008]

1 to 5 show a first embodiment of the present invention. The present invention includes, as an example, an upper conveyer A and a lower conveyer B, in which the upper and lower conveyer conveyors rotate belts in opposite directions to hold and convey an item W between them. It is applied to a power transmission device C that transmits a rotational driving force from a lower conveyor B having a source P to an upper conveyor A. In this embodiment, the power transmission device C is provided with a link action so that the power transmission device C swings following the uneven shape of the article W conveyed by the upper conveyor A.

The power transmission device C supports a driving roller 1 driven by rotation of a drive source P provided on a lower conveyor B at one end of a frame 7, and a driven roller for driving an upper conveyor A at the other end. The roller 2 is rotatably supported, and a belt-shaped belt, a belt-shaped belt or an endless belt 3 such as a V-belt is wound between the rollers 1 and 2 so that the rotation of the driving roller 1 is transmitted to the driven roller 2. It is configured. In addition, the rotation directions transmitted through the gear G are reversed so that the upper conveyor A and the lower conveyor B rotate in opposite directions.

In the present invention, the tensioning device for applying an appropriate tension to the endless belt 3 is constructed as follows. The tension roller 4 that gives a tension force to the endless belt 3 is rotatably supported at one end, and the arm 5 having an attachment fixing portion 9 having an elongated hole 8 for fixing is driven by the drive roller 1 at the other end. It is arranged on the frame 7 between the roller 2. This arm 5 is a fixed seat at the mounting and fixing part 9.
The endless belt 3 of the frame 7 is tightened and fixed by a bolt 6 via a pin 10. A slide pin 11 is vertically provided at a lower portion of one end of the arm 5 (opposite to the mounting and fixing portion 9), and a slide groove portion 12 on which the slide pin 11 slides is provided on the upper surface of the frame 7. In this embodiment, the slide pin 11 is provided integrally with the tension roller shaft 13 that supports the tension roller 4. Slide groove 12 provided on the frame 7
Has a linear bottomed groove oblique to the transfer path of the endless belt 3 so that the tension roller 4 is gradually pushed into the endless belt 3 and the pressing force thereof can be increased or decreased for adjustment. .

Next, the operation of the present invention will be described with reference to FIG. When applying tension to the endless belt 3, the bolt 5 is loosened so that the arm 5 can be moved.
The slide pin 11 is slid along the slide groove 12 formed in the frame 7 to gradually press the tension roller 4 against the endless belt 3. At this time, as the slide pin 11 moves along the slide groove portion 12,
Although the distance between the slide pin 11 and the bolt 6 changes, the long hole 8 formed in the mounting and fixing portion 9 of the arm 5 causes the arm 5 to move.
Can be moved in the longitudinal direction. In this way, the attachment fixing portion 9 is tightened with the bolt 6 to fix the arm 5 at a position where appropriate tension is applied to the endless belt 3 by the tension roller 4. Then, in this state,
The arm 5 is tensioned by the tension of the endless belt 3 in a tensioned state.
The force acting on is distributed to the force that the slide pin 11 presses the inner surface of the slide groove portion 12 and the force that is applied to the attachment fixing portion 9 of the arm 5, and the force that is applied to the fixing bolt 6 is reduced. . Since the slide pin 11 is in contact with the inner surface of the slide groove portion 12 at the time of transmitting the driving force, the arm 5 can be prevented from swinging even if there is vibration or load change. Further, even during the tension adjustment, the slide pin 11 is always in sliding contact with the inner surface of the slide groove portion 12, so that abrupt rebound of the arm 5 due to the tension of the endless belt 3 can be prevented.

FIG. 6 shows a second embodiment of the present invention. The position of the bolt 6 for fastening and fixing the arm 5 is set outside the rotation track of the endless belt 3, and the slide pin 11 provided on the arm 5 is different from the tension roller shaft 13.
Moreover, it is provided at a position that is not coaxial. Also in this embodiment, it is possible to obtain the same effect as that of the first embodiment.

The present invention is not limited to the above-described embodiment, and for example, the slide groove portion 12 may be provided so as to penetrate the frame 7, and the arm 5 is fixed to the penetrated slide groove portion 12. Alternatively, another fixing means may be provided, and the fixing means and the bolt 6 for tightening the existing mounting and fixing portion 9 may be used for double fixing.

[0014]

According to the present invention, a drive roller is rotatably supported at one end of a frame and a driven roller is rotatably supported at the other end, and an endless belt is wound between the rollers to rotate the drive roller. In a power transmission device that transmits to a driven roller, an arm that rotatably supports a tension roller at one end and has an attachment fixing portion at the other end is disposed on the frame between the drive roller and the driven roller. In addition, a slide pin is vertically provided on the lower part of one end of the arm, and a slide groove portion on which the slide pin slides is provided on the upper surface of the frame, and the arm is provided on the slide groove portion via the slide pin. By moving along the side, the tension roller presses the endless belt in a tensioned state to move the arm by the attachment fixing portion to the frame. Even when it is necessary to apply a large tension to the endless belt because it is fixed, the force acting on the arm by the tension of the endless belt is a force with which the slide pin presses the inner surface of the slide groove portion, Since the force applied to the attachment fixing portion is distributed, the force applied to the attachment fixing portion is reduced, and at the time of transmitting the driving force, the slide pin is in contact with the inner surface of the slide groove portion. Since the swing of the arm is prevented even against vibration or load fluctuation over time, the bolt of the mounting and fixing portion is unlikely to loosen, and the endless belt can be maintained at a predetermined tension force. Is.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a power transmission device to which the present invention is applied.

FIG. 2 is a side view of the inside showing the first embodiment of the present invention.

FIG. 3 is a plan view of the inside showing the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing a first embodiment of the present invention.

FIG. 5 is an operation explanatory view showing the first embodiment of the present invention.

FIG. 6 is a side view showing a second embodiment of the present invention.

FIG. 7 is a side view showing a conventional technique.

[Explanation of symbols]

 1 Drive Roller 2 Driven Roller 3 Endless Belt 4 Tension Roller 5 Arm 7 Frame 9 Mounting Fixture 11 Slide Pin 12 Slide Groove C Power Transmission Device

Claims (1)

[Claims] 1. A drive roller is rotatably supported at one end of a frame, and a driven roller is rotatably supported at the other end, and an endless belt is wound between the rollers to transmit the rotation of the drive roller to the driven roller. In the power transmission device, a tension roller is rotatably supported at one end and an arm having an attachment fixing portion at the other end is arranged on the frame between the drive roller and the driven roller, and A slide pin is vertically provided on the lower part of one end of the arm, while a slide groove portion for sliding movement of the slide pin is provided on the upper surface of the frame, and the arm is moved along the slide groove portion via the slide pin. The tension roller presses the endless belt in a tensioned state so that the arm is fixed to the frame by the attachment fixing portion. Belt tensioning device characterized by and.