JP3567211B2 - Tendency drive roll - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tension drive roll for feeding a film, cloth, paper or the like.
[0002]
[Prior art]
FIG. 5 is a longitudinal sectional view of a conventional tension drive roll (hereinafter simply referred to as a roll). As shown in this figure, a roll 100 is formed by a shaft 102 via a pair of bearings 104 and a cylindrical shell 106. Is provided. The shaft 102 is mounted on a pair of support members 110, 110 via a bearing 108.
[0003]
When the roll 100 guides a web such as a film, paper, cloth, or the like, the shaft 102 is rotated by the drive pulley 112 in accordance with the running speed V of the web, and the shell 106 is rotated together with the guide to guide the web. I do.
[0004]
[Problems to be solved by the invention]
However, with the roll 100 having the above configuration, the shaft 102 also rotates in accordance with the running speed V of the web at a constant speed other than acceleration and deceleration, such as at the time of start and end, so that the web is smoothly guided. can do. However, the following problems occur during acceleration / deceleration.
[0005]
The only mechanical element that transmits the rotation of the shaft 102 to the shell 106 is the resistance of the pair of bearings 104. If the resistance is not reduced, the purpose of reducing the stress applied to the web cannot be achieved when there is a speed difference between the rotation of the shaft 102 and the web, which is the purpose of driving the tension.
[0006]
However, in this case, during acceleration / deceleration, the rotation of the shaft 102 and the rotation of the shell 106 are greatly deviated, and stress occurs on the web. For example, at the time of startup, the running speed of the shaft 102 and the web has reached V, but if the resistance of the bearing 104 between the shaft 102 and the shell 106 is small, only the shell 106 can follow the speed V. Therefore, a speed difference occurs between the web and the shell 106. This speed difference pulls the web in a direction opposite to the running direction, resulting in extra tension and harm to the web.
[0007]
In view of the above problems, the present invention provides a roll in which the shell itself can easily follow the rotation speed of the shaft.
[0008]
[Means for Solving the Problems]
The tension drive roll according to claim 1 of the present invention is a tension drive roll in which a cylindrical shell is provided on a rotary shaft via a bearing, wherein a pair of rotary members are provided on the rotary shaft located near both sides of the shell. Attachment, the portion of the shell facing the pair of rotating members is formed of a conductor, and the portion of the pair of rotating members facing the portion of the shell facing the conductor is circumferentially arranged. A plurality of magnets are provided at predetermined intervals along, and when there is a speed difference between the shell and the rotating member, a rotating force is generated by an eddy current and a magnetic line of force of the magnet, thereby forming the shell. The rotation member follows the rotation of the rotation member .
[0009]
The tension drive roll according to claim 2, wherein in the tension drive roll provided with a cylindrical shell via a bearing on a rotary shaft, a pair of rotary members are attached to the rotary shaft located near both sides of the shell, A portion of the pair of rotating members opposed to a shell is formed of a conductor, and a portion of the shell opposed to the conductor portion of the pair of rotating members is provided with a plurality of portions along a circumferential direction. A magnet is provided at a predetermined interval, and when there is a speed difference between the shell and the rotating member, a rotating force is generated by an eddy current and a line of magnetic force of the magnet, and the shell is rotated by the rotating member. It follows the rotation .
[0010]
According to the roll of the present invention, when the shaft starts to rotate, the shell has not yet rotated, so that a speed difference occurs between the pair of rotating members and the shell. Then, due to the relationship between the conductor and the magnet, an eddy current is generated between the two, and by the rotation of the rotating member, a large driving force for rotating the shell is generated, and the shell quickly rotates the rotating member, that is, the rotation of the shaft. Can follow.
[0011]
Even in the case of the tension drive roll according to the second aspect, the shell can easily follow the rotation of the shaft similarly to the above.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
[0013]
FIG. 1 is a longitudinal sectional view of a tension driving roll 10 for web W of the present embodiment, and FIG. 2 is a sectional view taken along line AA in FIG.
[0014]
The shaft 12 of the roll 10 is provided with a cylindrical shell 16 via a pair of bearings 14. The shell 16 is formed of a conductor such as iron or aluminum.
[0015]
The shaft 12 is rotatably supported by a pair of support members 20 having bearings 18. The shaft 12 is rotatable at a predetermined speed by a driving pulley 22.
[0016]
The shafts 12 located on both sides of the shell 16 are provided with a pair of disk-shaped rotating members 24, 24. As shown in FIG. 2, four magnets 26 are provided on the inner surface of the rotating member 24 every 90 degrees. Both sides of the shell 16 are located on a surface facing the position where the magnet 26 is provided. The rotating member 24 is fixed to the shaft 12, and when the shaft 12 rotates, the rotating member 24 also rotates at the same speed. Note that the rotating member 24 and the shell 16 are slightly spaced so as not to contact each other.
[0017]
A case where the web W is guided at high speed by using the roll 10 having the above configuration will be described.
[0018]
When the roll 10 is started, the shaft 12 is gradually accelerated to increase its speed. In this case, although the shell 16 is provided via the bearing 14, the shaft 12 is rapidly accelerated, so that the shell 16 is initially difficult to follow the rotation of the shaft 12. However, since the rotating member 24 rotates together with the shaft 12, there is a large difference in the rotating speed between the rotating member 24 that has rapidly increased the rotating speed and the low-speed shell 16 that is not following. Therefore, an eddy current is generated on the surface of the shell 16 which is a conductor by the four magnets 26 of the rotating member 24, and a rotational force substantially proportional to a rotational speed difference is generated by the eddy current and the magnetic force lines of the magnet 26. This rotational force is applied to the shell 16, and the shell 16 synchronizes more quickly with the rotational speed of the rotating member 24 (the shaft 12) than in the related art.
[0019]
When the rotation speed of the shell 16 becomes substantially the same as the speed V of the web W, that is, when the rotation speed of the rotation member 24 becomes substantially the same, the rotation speed difference between the shell 16 and the rotation member 24 disappears, The rotating force due to the eddy current and the magnetic force lines described above decreases. In this case, the resistance of the bearing 14 allows the shell 16 to rotate at substantially the same speed as the shaft 12. Therefore, there is no speed difference between the web W and the shell 16, and no stress is applied to the web W. In particular, when the web W is run at a high speed of about 100 m / min, the effect is great because the rapid acceleration is large.
[0020]
Also, at the time of rapid acceleration / deceleration such as at the end, the shell 16 becomes the same as the rotational speed of the shaft 12 (that is, the running speed V of the web W) quickly by the rotating member 24 in the same manner as described above. There is no speed difference between the two, and no stress is applied to the web W.
[0021]
Furthermore, when the vehicle is traveling at a constant speed, the shell 16 is rotated by the bearing 14 at the same speed as the web W, as in the conventional case. No stress. In this case, since the shell 16 itself follows the web W, even if the rotation speed of the shaft 12 does not completely match the running speed of the web W, the running speed of the shell 16 and the running speed of the web W are completely the same. Therefore, no stress is applied to the web W.
[0022]
In the above embodiment, four magnets 26 are provided on the rotating member 24 at every 90 ° as shown in FIG. 2. However, the present invention is not limited to this, and two magnets may be provided at every 180 °. May be provided, a plurality of magnets 26 may be provided at appropriate intervals.
[0023]
Next, a second embodiment of the roll 10 will be described with reference to FIG.
[0024]
The difference between the present embodiment and the first embodiment lies in the structure of the rotating member 24.
[0025]
That is, in the present embodiment, the magnet 26 is provided on the outer peripheral surface of the rotating member 24 and is arranged so as to face the inner peripheral surface of the shell 16.
[0026]
Even with this structure, if the rotating member 24 rotates, eddy currents and lines of magnetic force are generated, and the shell 16 can quickly follow the rotation.
[0027]
Further, in the first and second embodiments, the magnet 26 is provided on the rotating member 24 and the shell 16 is made of a conductor. However, the present invention is not limited to this. May be configured as a conductor.
[0028]
Further, it is not necessary to make the entire shell 16 or rotating member 24 a conductor, and the effect of the present invention can be obtained if only the portion facing the magnet 26 is made of a conductor.
[0029]
【The invention's effect】
As described above, in the case of the tension drive roll of the present invention, when there is a speed difference between the shell and the rotating member, a rotating force is generated by the eddy current and the magnetic lines of force of the magnets, and the shell quickly rotates the rotating member. Since the web can be followed, no stress is applied to the web running by the tension drive roll.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a roll showing a first embodiment of the present invention.
FIG. 2 is a sectional view taken along line AA in FIG.
FIG. 3 is a perspective view of a roll showing the first embodiment.
FIG. 4 is a longitudinal sectional view of a main part of a roll according to a second embodiment.
FIG. 5 is a longitudinal sectional view of a conventional roll.
[Explanation of symbols]
10 Roll 12 Shaft 14 Bearing 16 Shell 18 Bearing 20 Supporting Member 22 Drive Pulley 24 Rotating Member 26 Magnet

Claims (2)

In a tension drive roll in which a cylindrical shell is provided on a rotating shaft via a bearing,
Attach a pair of rotating members to the rotating shaft located near both sides of the shell,
The shell portion facing the pair of rotating members is formed of a conductor,
In addition, a plurality of magnets are provided at predetermined intervals along a circumferential direction of a portion of the pair of rotating members opposed to the conductor portion of the shell ,
When there is a speed difference between the shell and the rotating member, a rotating force is generated by the eddy current and the lines of magnetic force of the magnets, and the shell follows the rotation of the rotating member. Tendency driven rolls featured. In a tension drive roll in which a cylindrical shell is provided on a rotating shaft via a bearing,
Attach a pair of rotating members to the rotating shaft located near both sides of the shell,
A portion of the pair of rotating members opposed to the shell is formed of a conductor,
Further, a plurality of magnets are provided at predetermined intervals along a circumferential direction on a portion of the shell opposed to the portion of the conductor of the pair of rotating members ,
When there is a speed difference between the shell and the rotating member, a rotating force is generated by the eddy current and the lines of magnetic force of the magnets, and the shell follows the rotation of the rotating member. Tendency driven rolls featured.

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