JPH1047446A - Belt-offset prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress contact noises from a belt-drive system using a relatively broad endless belt and the wear of the belt in automatically aligning a pulley by bringing the belt being offset on the pulley into contact with an auxiliary member, and simplify the structure of the system. SOLUTION: A belt-offset prevention device includes a second pulley 4 arranged to bring a flat belt 5 wound thereon offset axially toward its one end following the movement of the belt 5, an extension coil 6 for continuously urging the one end portion of the second pulley 4 upward opposite to the downward direction that the second pulley 4 tilts to bring the flat belt 5 offset axially toward the other end, and a conical pulley 8 which contacts with the flat belt 5 offset axially toward the one end to cause it to press the one end portion of the second pulley 4 downward against the urging force of the spring 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt deviation preventing device, and more particularly to a device for preventing a relatively wide endless belt from axially displacing on a pulley as the belt travels. About.

[0002]

2. Description of the Related Art For example, like a flat belt or a toothed belt,
In a belt drive system that has a large degree of freedom in the axial direction of the pulley around which the belt is wound (belt width direction), one of the axial directions is caused by misalignment between the pulleys and the biasing force of the belt itself. It is known that the belt shifts to the center, and the belt deviates from the pulley if no measures are taken. In particular, when a belt that is relatively wide with respect to the belt circumference is used, a very strong biasing force is generated, and various problems occur.

As a countermeasure, a flange is provided integrally with one end or both ends of a pulley, and when the belt is offset, the belt end surface is brought into contact with the flange so that the belt is not shifted further. For flat belts, it is common practice to make the pulley a convex crown so that the belt is held at the center of the pulley, etc. However, there is a problem that the contact noise is generated and the belt end face is easily worn. In this case, the diameter of the flange is usually larger than the winding diameter including the back surface of the belt wound around the pulley, and therefore, the design is made in consideration of the space for the flange. There is a need. on the other hand,
In the case of, the offset prevention effect increases as the crown increases, but if the crown is large for a wide belt,
In particular, in the case of a flat belt made of a film with low elongation, a remarkable difference in tension occurs between the central portion and the end portion of the crown, and the transmission capacity is significantly reduced.

Therefore, as an effective countermeasure that does not involve the above-described problems, conventionally, a flange member rotatable separately from the pulley is arranged as an auxiliary member at one end of the rotation shaft of the pulley, and a belt member is provided. When the end face comes in contact with the flange member, the flange member is rotated by the contact, and the rotation shaft is pulled by a cord attached to the flange member to adjust the alignment of the shaft. Are known.

According to this countermeasure, since the flange as in the above case is not required, the contact noise of the belt and the abrasion of the belt due to the presence of such a flange are small. In addition, no space is required for providing a flange on the pulley, and no processing of the pulley for providing such a flange is required, which is economical. Further, since it is not necessary to form the pulley into a crown shape as in the case (1), the tension balance of the belt is almost uniform, and therefore, the reduction in the transmission capacity due to such imbalance of the tension is small. Further, the processing of the pulley is easy because it is not a crown shape, and it is economical.

[0006]

However, in the above-mentioned conventional measures, the running belt comes into contact with the flange member to which a load is applied, and the flange member is driven to rotate. On the other hand, there is a problem that contact noise and belt wear increase.

[0007] Further, there is a problem that the structure of the flange member and the like are complicated because the mechanism of changing the attitude of the rotary shaft via the cord attached to the flange member is used.

The present invention has been made in view of the above points, and a main object of the present invention is to provide a belt drive system using a relatively wide endless belt.
When adjusting the alignment of the pulley automatically by contacting the belt that is offset on the pulley with the auxiliary member, noise and belt wear during contact can be reduced by improving the alignment adjustment mechanism. Another object of the present invention is to simplify the structure.

[0009]

In order to achieve the above object, according to the present invention, when the belt is offset and contacts an auxiliary member (auxiliary pulley), the alignment of the pulley shaft is adjusted not by the auxiliary member but by the belt. Let it adjust itself.

Specifically, according to the first aspect of the present invention, the belt is arranged so as to be biased to one end in the axial direction as the wound belt travels, and the other end of the belt is moved in the axial direction. A pulley in which one end of the axis is movable in a direction in which the pulley is shifted to the side, and a direction in which the pulley is disposed on one end of the pulley and the belt is shifted to the other end in the axial direction. Biasing means for constantly biasing the one end portion of the pulley in the opposite direction to hold the pulley in a state in which the belt is biased to one axial end, and the pulley is attached to one end of the pulley. Is arranged rotatably about an axis substantially parallel to the axis of the pulley, and comes into contact with a belt that is biased to one end in the axial direction to cause the one end of the pulley to resist the urging force of the urging means. Auxiliary member as an auxiliary member To make and a Li. That is,
Initially, the belt is set on the pulley so as to be offset toward one end in the axial direction, and when the belt is offset, the alignment of the pulley is changed by the belt itself to move the belt toward the other end in the axial direction. The belt is run at a certain position on the pulley by repeating this action.

In the above configuration, when the belt starts running, the pulley is arranged so that the belt wound around the pulley is biased toward one end in the axial direction as the belt runs. Approaching one end in the axial direction. Then, when approaching to one end, the belt enters between the auxiliary pulley and one end of the pulley. At this time, as the belt enters between the two pulleys, one end of the pulley is pushed in against the urging force of the urging means, whereby the belt is moved to the other end in the axial direction. Change the pulley so that it is offset. As a result, the alignment of the axis of the pulley moves to the opposite side, so that the belt tends to shift to the other end, which is opposite to the one end in the axial direction. That is, the belt that has entered between the two pulleys exits from between the two pulleys. Then, the pushing action of the belt against the one end side portion of the pulley gradually weakens, and accordingly, the one end side portion of the pulley is biased again by the urging force of the urging means to the axially one end side. The pulley moves in the changing direction. By repeating this operation, the belt runs at a fixed position in the axial direction on the pulley. At this time, since the auxiliary pulley has no load, even when the auxiliary pulley comes into contact with the belt in a stopped state, the belt is brought into contact with an auxiliary member (flange member) to which a load is applied. The impact at the time of contact is smaller than in the case, so that the noise at the time of contact and the belt wear are also smaller.

According to the second aspect of the present invention, one end of the shaft center can be moved in a direction in which the belt is shifted toward the other end in the axial direction as the wound belt runs, and the belt can be moved. A pulley whose other end of the shaft is movable in a direction changing to a state where the belt is shifted to one end in the axial direction, and a state where the belt is arranged at one end of the pulley and the belt is shifted to the other end in the axial direction. One end urging means for always energizing one end of the pulley in a direction opposite to the direction in which the pulley changes, and an axis substantially parallel to the axis of the pulley at one end of the pulley. Auxiliary member that is rotatably disposed on the belt and contacts the belt that is biased to one end in the axial direction to push the one end of the pulley into the belt against the urging force of the one end urging means. While having one end side auxiliary pulley, The other end of the pulley is disposed at the other end of the pulley and always biases the other end of the pulley in a direction opposite to the direction in which the pulley changes so as to bias the belt toward one end in the axial direction. An end-side urging means, disposed at the other end of the pulley so as to be rotatable about an axis substantially parallel to the axis of the pulley, and in contact with a belt that is offset to the other end in the axial direction. The other end side pulley as an auxiliary member for pushing the other end side portion of the pulley into the belt against the urging force of the other end side urging means is provided. In other words, the belt is initially wound around a pulley that has been set so that there is no misalignment, but the belt may move to either end of the pulley due to the belt's own biasing force or a delicate balance of tension. is there. When the belt shifts, the belt itself changes the alignment of the axis of the pulley to give a biasing force to the opposite side. On the other hand, when the belt shifts to the opposite end, the same effect is obtained. Then, the belt is shifted to the original end again, so that the belt runs at a fixed position in the axial direction on the pulley.

In the above configuration, even if the axis of the pulley is set so as not to cause misalignment, the belt may be offset due to the offset force of the belt itself or a delicate balance of tension. Then, for example, if the belt on the pulley is offset toward one end in the axial direction,
The belt enters between the one end side auxiliary pulley and the one end side portion of the pulley. At this time, as the belt enters between the two pulleys, one end of the pulley is pushed in against the urging force of the one-end urging means, thereby pushing the belt in the other axial direction. Change the pulley so that it is offset toward the end. As a result, the alignment of the axis of the pulley moves to the opposite side, so that the belt tends to shift to the other end, which is opposite to the one end in the axial direction. Then, when the belt shifts to the other end as it is, it returns to the original one end side by the same action. By repeating this phenomenon, the belt runs at a fixed position in the axial direction on the pulley.

According to the third aspect of the present invention, the first or second aspect is provided.
In the present invention, the auxiliary pulley is a conical pulley having a tapered cross section in which the diameter of the pulley decreases toward the center of the pulley.

In the above configuration, when the belt on the pulley is shifted toward the auxiliary pulley and comes into contact with the auxiliary pulley, the auxiliary pulley has a tapered cross-section having a smaller diameter toward the center of the pulley. Since the belt is a conical pulley, the belt smoothly enters between the auxiliary pulley and the pulley, and accordingly pushes the pulley against the urging force of the urging means. Therefore, the pushing action of the pulley by the belt according to the first or second aspect of the invention is performed smoothly.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the conical pulley is configured to rotate at substantially the same speed as the peripheral speed of a belt wound around the pulley and running.

In the above configuration, when the belt is offset toward the conical pulley and comes into contact with the conical pulley, the conical pulley rotates at substantially the same speed as the peripheral speed of the belt. As compared with the case where the rotation is stopped or the case where the belt is rotated at a speed different from the peripheral speed of the belt, the two are in smooth contact with each other without generating large sliding resistance and sliding noise. Therefore, the generation and wear of the contact noise caused by the contact of the belt with the conical pulley can be suppressed.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the conical pulley is arranged so as to be in contact with the pulley so as to be rotationally driven by the rotational force of the pulley.

In the above configuration, the conical pulley is rotationally driven by the rotational force of the pulley when in contact with the pulley. At this time, the peripheral speed of the conical pulley is substantially equal to the peripheral speed of the pulley, and the peripheral speed of the belt is also substantially equal to the peripheral speed of the pulley. As a result, the auxiliary pulley rotates at substantially the same speed as the peripheral speed of the belt, so that the operation according to the fourth aspect of the invention can be performed with a proper and simple structure.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIGS. 1 to 3 show the overall structure of a belt shift prevention device according to a first embodiment of the present invention. This prevention device uses a relatively wide endless flat belt. Used for the belt drive system used.

The above-mentioned belt drive system comprises two first and second rotating shafts 1 and 2 rotatably provided about a horizontal axis substantially parallel to each other, and a rotating shaft for each of the rotating shafts 1 and 2. First and second 2 consisting of a flat pulley which is supported
There are provided two pulleys 3 and 4 and a flat belt 5 wound around the two pulleys 3 and 4 so as to run.

Of the two rotating shafts 1 and 2, the first rotating shaft 1 located to the right in each of FIGS. 2 and 3 is held in a state in which both ends cannot move in the radial and thrust directions. Have been. On the other hand, the second rotating shaft 2 located on the left side of each drawing moves the flat belt 5 wound around the second pulley 4 to move the belt 5 at one end in the axial direction (the left end side in FIG. 1). ,
(The lower end side in FIG. 3).

The one end 2a of the second rotating shaft 2
The left end of FIG. 1 and the lower end of FIG. 3 change the state of the second pulley 4 so that the flat belt 5 is biased toward the other axial end (the right end in FIG. 1 and the upper end in FIG. 3). It is provided so as to be movable in the downward direction as the direction of the movement. On the other hand, the other end 2b (the right end in FIG. 1, the upper end in FIG. 3) of the second rotating shaft 2 is fixed to the fixed body 7 so as not to hinder the movement of the one end 2a and to slide in the axial direction. The pivot is fixed.

One end of the second pulley 4 is provided as an urging means for constantly urging the one end 2a of the second rotating shaft 2 upward in a direction opposite to the downward direction. A tension coil spring 6 is arranged. Further, a flat belt 5 offset to one end in the axial direction is provided on one end of the second pulley 4.
A conical pulley 8 is disposed as an auxiliary pulley that pushes the one end portion of the second pulley 4 into the belt 5 against the urging force of the tension coil spring 6 in contact with the belt 5.

The conical pulley 8 is arranged so as to be rotatable around a horizontal axis substantially parallel to the axis of the second pulley 4, and one end 2 a of the second rotary shaft 2 is extended by a tension coil spring 6. The pulley 4 is disposed at a position above the second pulley 4 on the side to be pulled and slightly near the center from one end of the pulley 4, and has a tapered cross section in which the diameter of the pulley decreases toward the center of the second pulley 4. . Further, in this embodiment, the conical pulley 8 is in contact with the pulley surface of the second pulley 4 on the large diameter side of the pulley surface. The conical pulley 8 may be arranged so as not to contact the second pulley 4. However, when the end surface of the flat belt 5 comes into contact with the conical pulley 8 such as when the thickness of the flat belt 5 is thin, the conical pulley 8 may be disposed. When it is desired to prevent abrasion as much as possible, it is preferable that the conical pulley 8 is disposed in contact with the second pulley 4.

Here, the operation of the belt misalignment preventing device configured as described above will be described with reference to FIG. 4 and FIG. When the flat belt 5 is driven to travel in the belt driving system, the flat belt 5 on the second pulley 4 is moved to one end side in the axial direction (that is, the conical pulley 8 side) due to the misalignment of the second pulley 4. As shown in FIG. 4, the end surface of the belt 5 comes into contact with the pulley surface of the conical pulley 8. At this time, since the conical pulley 8 is in contact with the second pulley 4, the conical pulley 8 and the flat belt 5 have substantially the same speed, so that the end surface of the flat belt 5 contacts the surface of the conical pulley 8. The contact noise is low, and the end face of the belt 5 is less worn. When the flat belt 5 is thick and the peripheral speed on the upper surface side of the flat belt 5 is faster than the peripheral speed of the second pulley 4, the conical pulley 8 is floated from the second pulley 4. Better,
Even in this case, since the conical pulley 8 rotates lightly with no load, the contact noise when the flat belt 5 comes into contact with the conical pulley 8 is small, and the abrasion hardly occurs.

After the flat belt 5 comes into contact with the conical pulley 8, if the belt 5 is to be further shifted in the same direction, the flat belt 5
Penetrates between the second pulley 4 and the conical pulley 8, whereby the one end portion of the second pulley 4 pulled up by the extension coil spring 6 as shown in FIG. Is pressed downward against the urging force of the tension coil spring 6. Then, when the one end portion of the second pulley 4 is pushed down, the misalignment is reversed from the initial state, so that the flat belt 5 is moved in the opposite axial direction to the other end side (FIG. 4). And the right side of FIG. 5). By repeating this phenomenon, the flat belt 5 travels at a fixed position in the axial direction on the second pulley 4, and thus, deviation is prevented.

Therefore, according to the present embodiment, the second pulley 4 is arranged so that the flat belt 5 is biased to one end side in the axial direction, and the one end 2a of the second rotary shaft 2 is The second state is such that the belt 5 is shifted toward the other end in the axial direction.
After the pulley 4 is movable in the changing direction, the one end 2a is moved upward in a state where the second pulley 4 changes so that the flat belt 5 is shifted toward the other end in the axial direction. , While being in contact with the flat belt 5 offset to one end in the axial direction, and pushing the one end portion of the second pulley 4 downward into the flat belt 5, whereby the second pulley 4, the alignment of the pulley is prevented by the flange member which comes into contact with the flat belt. And the occurrence of contact noise and belt abrasion due to contact can be suppressed.

In the first embodiment, the tension coil spring 6 is used as the urging means, but rubber or the like may be used as long as it can be energized.

In the first embodiment, the one end 2a of the second rotating shaft 2 is urged upward by the urging means. However, the flat belt 5 can be biased toward one end. If it is the direction, it may be urged toward a direction other than the upward direction.

Further, in the first embodiment, the conical pulley 8 pushes the one end portion of the second pulley 4 downward, but the flat belt 5 is pressed against the urging force of the urging means. It may be pushed in any direction other than downward as long as it can be biased toward the end.

(Embodiment 2) FIG. 6 shows the overall configuration of a belt shift prevention device according to Embodiment 2 of the present invention. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the second pulley 4 is arranged so as to be basically free from misalignment with respect to the first pulley 3, and both ends 2a and 2b of the second rotary shaft 2 are arranged in the radial direction. It is provided movably.

Specifically, one end 2 of the second rotary shaft 2
a can be moved downward as a direction in which the second pulley 4 changes so that the flat belt 5 is shifted toward the other end side (the right end side in FIG. 6) in the axial direction. The second pulley 4 can be moved downward as a direction in which the second pulley 4 changes so that the flat belt 5 is shifted toward one end side (left end side in the figure) in the axial direction. In addition to the one-side tension coil spring 6 as one-side urging means and the one-side conical pulley 8 as one-side auxiliary pulley disposed on one end side of the second pulley 4, the other end of the second pulley 4 is provided. The other end side tension coil spring 6 as the other end side urging means which constantly urges the other end side portion of the second pulley 4 upward in the opposite direction to the above-mentioned downward direction. The other end of the second pulley 4 is pushed into the flat belt 5 against the urging force of the other end side tension coil spring 6 by contacting the flat belt 5 offset to the other end in the axial direction. And an end-side conical pulley 8 as an end-side auxiliary pulley. The other configuration is the same as that of the first embodiment, and the description is omitted.

Next, the operation of the belt misalignment preventing device configured as described above will be described.

The second pulley 4 is set so as not to be misaligned with respect to the first pulley 3. However, the flat belt 5 is moved by the delicate balance of the biasing force and tension of the flat belt 5 itself. For example, when it is shifted toward one end side in the axial direction on the upper side 4, it enters between the conical pulley 8 at one end side and one end side portion of the second pulley 4. At this time, the flat belt 5 pushes the one end portion of the second pulley 4 against the urging force of the one end tension coil spring 6 in response to the intrusion between the pulleys 8 and 4. Then, the second pulley 4 is moved to a state where the flat belt 5 is biased toward the other end in the axial direction.
To change. As a result, the alignment of the shaft moves to the opposite side, so that the flat belt 5 is now biased toward the other end, which is opposite to the one end in the axial direction. And
When the flat belt 5 shifts to the other end as it is, it returns to the original one end side by the same action. By repeating this phenomenon, the flat belt 5 runs at a fixed position in the axial direction on the second pulley 4.

Therefore, in the present embodiment, the structure is more complicated than in the case of the first embodiment, as much as two tension coil springs 6 and two conical pulleys 8 are required. The same effect as in the case of can be achieved.

[0039]

As described above, according to the first and second aspects of the present invention, the auxiliary pulley only comes into contact with the belt, and the alignment is adjusted by the belt itself. The impact at the time of contact is smaller than that in the conventional case in which alignment is adjusted by rotating and driving, so that it is possible to suppress the generation of contact noise and belt wear due to contact. In addition, since only an urging means such as a spring or rubber and an auxiliary pulley such as a conical pulley are basically required, the structure can be simplified as compared with a conventional deviation preventing device.

According to the third aspect of the present invention, the auxiliary pulley is
Since the conical pulley has a tapered cross section in which the diameter of the pulley decreases toward the center of the pulley, the belt in contact with the auxiliary pulley can be smoothly inserted between the auxiliary pulley and the pulley. The effects of the first and second aspects of the present invention can be obtained properly and efficiently.

According to the fourth aspect of the present invention, the conical pulley is rotated at substantially the same speed as the peripheral speed of the belt.
The contact noise and the wear of the belt generated when the belt comes into contact with the conical pulley can be efficiently suppressed, and the effects of the first and second aspects of the present invention can be properly obtained.

According to the fifth aspect of the present invention, the conical pulley is rotated at the same speed as the peripheral speed of the belt by contacting the pulley with the pulley, so that the effect of the fourth aspect of the present invention can be obtained with a simple structure. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2;

FIG. 2 is a front view showing the entire configuration of the belt displacement prevention device according to the first embodiment of the present invention.

FIG. 3 is a plan view showing the entire configuration of the belt offset device.

FIG. 4 is an enlarged partial cross-sectional view showing a state where the flat belt is offset to one end side in the axial direction and contacts a conical pulley.

FIG. 5 is an enlarged partial cross-sectional view showing a state where the second pulley is being pushed by the flat belt that has entered between the conical pulley and the second pulley.

FIG. 6 is a diagram corresponding to FIG. 1 showing an overall configuration of a belt shift prevention device according to a second embodiment of the present invention.

[Explanation of symbols]

 4 Flat pulley (pulley) 5 Flat belt (belt) 6 Tension coil spring (biasing means) 8 Conical pulley (auxiliary pulley)

Claims (5)

[Claims] 1. A belt is arranged in such a manner that the belt is biased toward one end in the axial direction as the wound belt travels,
A pulley whose one end of the axis is movable in a direction changing to a state in which the belt is shifted to the other end in the axial direction; and a state in which the belt is arranged at one end of the pulley and the belt is shifted to the other end in the axial direction. Biasing means for constantly biasing one end of the pulley in a direction opposite to the direction in which the pulley changes, and rotating about an axis substantially parallel to the axis of the pulley at one end of the pulley. An auxiliary pulley that is disposed so as to be able to contact the belt that is biased to one end in the axial direction and that pushes one end of the pulley into the belt against the urging force of the urging means. Belt shift prevention device. 2. One end of an axial center is movable in a direction that changes the state in which the belt is biased toward the other end in the axial direction as the wound belt runs, and the belt is moved in one end in the axial direction. A pulley, the other end of the axis of which is movable in a direction changing to a state in which the belt is shifted to a side, and a direction in which the pulley changes to a state in which the belt is shifted to the other end in the axial direction, which is disposed at one end of the pulley. Is disposed at one end of the pulley so as to be rotatable about an axis substantially parallel to the axis of the pulley. An end-side auxiliary pulley that contacts a belt that is offset to one end in the axial direction and pushes one end of the pulley into the belt against the urging force of the one-end urging means; The belt is biased to one end in the axial direction. The other end urging means for always energizing the other end of the pulley in a direction opposite to the direction in which the pulley changes to a state in which the pulley is changed; The belt is rotatably disposed about a substantially parallel axis, and comes into contact with the belt that is biased to the other end in the axial direction, and causes the other end of the pulley to contact the belt against the urging force of the other end urging means. A belt misalignment prevention device, comprising: 3. The belt shift preventing device according to claim 1, wherein the auxiliary pulley is a conical pulley having a tapered cross section whose diameter decreases toward the center of the pulley. Anti-skew device. 4. The belt deviation preventing device according to claim 3, wherein the conical pulley is configured to rotate at substantially the same speed as the peripheral speed of the belt wound around the pulley and running. Belt shift prevention device. 5. The belt shift device according to claim 4, wherein the conical pulley is disposed in contact with the pulley so as to be driven to rotate by the rotational force of the pulley. Anti-slip device.