JP4972338B2 - Belt conveyor using nip bearing - Google Patents

Description

  The present invention relates to a belt conveyor that drives a belt by pressing the belt against a driving roller with a nip bearing.

  In the belt conveyor using the nip bearing, the belt is driven by pressing the belt against the driving roller by the nip bearing and rotating the driving roller (Patent Document 1). Such a belt conveyor is configured such that the nip bearing can be separated from the drive bearing so that the belt can be easily attached and detached. That is, when the belt is attached and detached, the nip bearing is separated from the drive bearing, and when the belt mounting operation is completed, the nip bearing is pressed against the drive bearing with the belt interposed therebetween and fixed.

  The position of the nip bearing is fixed by fixing a bearing holding portion that rotatably holds the nip bearing to the conveyor body. For example, one end of the bearing holding portion is rotatably held by the conveyor main body, and a hook mechanism for fixing the bearing holding portion to the conveyor main body is provided at the other end sandwiching the nip bearing. That is, when the belt is attached or detached, the hook mechanism is disengaged, the bearing holding portion is rotated, and the nip bearing is separated from the drive roller.

On the other hand, after the belt is mounted, the bearing holding portion is rotated in the reverse direction, and the nip bearing is pressed against the driving roller with the belt interposed therebetween. Thereafter, the position of the bearing holding portion is fixed to the conveyor body using a hook mechanism provided at the other end. Further, the position of the nip bearing with respect to the driving roller is finely adjusted using an adjusting screw provided in the hook mechanism, and the pressing force applied to the belt is adjusted.
Japanese Patent Laid-Open No. 2002-338022

  In order to maintain the proper driving of the belt, it is necessary to maintain the gap (pressing force) between the driving roller and the bearing at an appropriate size. However, since the belt thickness changes over time due to wear, an appropriate gap is required. The magnitude of changes over time. However, in the method using the conventional hook mechanism, when the fine adjustment of the gap by the adjusting screw is completed, the size of the gap is fixed, and thus it is not possible to cope with such a change with time.

  In addition, endless belts are used for belt conveyors, but the joints of endless belts that join both ends of the belt are thicker than the other parts. It is generally too narrow for the part. Furthermore, since the drive roller is slightly decentered due to manufacturing errors, the size of the gap between the nip bearing and the drive roller varies as the drive roller rotates.

  However, in the conventional hook mechanism, since the gap between the nip bearing and the driving roller is fixed to one size, it is not possible to cope with the difference in thickness at the belt joint and the problem of roller eccentricity. Therefore, in the conventional belt conveyor using the hook mechanism, a state in which the nip pressure becomes excessive during the belt driving occurs periodically, thereby causing the belt to be worn or damaged early. Moreover, excessive nip pressure induces a malfunction of the drive mechanism.

  An object of the present invention is to make it possible to automatically adjust a gap between a driving roller and a nip bearing to an appropriate size in a belt conveyor using a nip bearing.

  The fastening mechanism of the present invention is a fastening mechanism for fixing and maintaining a state in which the nip bearing is pressed against the driving roller in a belt conveyor that presses the belt against the driving roller by the nip bearing, and is a bearing holding for holding the nip bearing. A nip bearing, a first engagement portion coupled to the bearing holding portion, and a second engagement portion detachably engaged with the first engagement portion and coupled to the conveyor body. Is pressed against the driving roller via the belt, and is maintained by the engagement of the first engaging portion and the second engaging portion, and the pressing force of the belt to the driving roller by the nip bearing Is adjusted by an urging means provided in the first or second engaging portion.

  One end of the bearing holding portion is rotatably held by the conveyor body, and the first engagement portion is connected to the other end of the bearing holding member. The first or second engaging portion has a structure using, for example, a hook. Further, the biasing means is made of, for example, an elastic member, and in this case, the elastic member is, for example, a spring.

  As described above, according to the present invention, the gap between the drive roller and the nip bearing can be automatically adjusted to an appropriate size in the belt conveyor using the nip bearing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the overall structure of a belt conveyor using a nip bearing according to an embodiment of the present invention.

  The belt conveyor 10 according to the present embodiment includes an endless belt 11, two idle rollers 12 and 13 and a driving roller 14 around which the endless belt 11 is wound, and a pair of nip bearings 15 that press the endless belt 11 against the driving roller 14. , 16. The nip bearings 15 and 16 are rotatably held by the bearing holding portion 17, and one end (rotating end portion) 17 </ b> A of the bearing holding portion 17 is rotatably held by the conveyor body 18.

  In a state where the endless belt 11 is mounted on the belt conveyor 10, the bearing holding portion 17 is kept substantially horizontal, and the endless belt 11 is sandwiched between the nip bearings 15 and 16 and the driving roller 14, and is held by the nip bearings 15 and 16. Pressed against the driving roller 14. That is, as shown in FIG. 1, the nip bearings 15 and 16 are arranged in a substantially horizontal state and are pressed toward the driving roller 14.

  On the other hand, the fastening mechanism 20 of this embodiment is provided at the other end (attachment end portion) 17B of the bearing holding portion 17 on the opposite side of the rotation end portion 17A across the nip bearings 15 and 16. That is, when the endless belt 11 is attached to the belt conveyor 10, the bearing holding unit 17 is moved by the fastening mechanism 20 so that the nip bearings 15 and 16 are kept in contact with the driving roller 14. 18 is fastened.

  FIG. 2 shows an enlarged perspective view of the fastening mechanism 20 of the present embodiment. A hook mechanism is used for the fastening mechanism 20 of the present embodiment. The hook mechanism 20 includes, for example, a hook 21 connected to the hook attachment portion 18A of the conveyor body 18 and an eye 22 connected to the attachment end portion 17B.

  The hook 21 is attached to an elastic member as urging means, for example, a fixing plate 24 connected to one end of a spring 23, and the other end of the spring 23 is connected to a hook attaching portion 18 </ b> A of the conveyor body 18. On the other hand, the eye 22 includes a rod 22A, and the tip of the rod 22A is orthogonal to the rod 24A and is rotatably connected to a shaft provided on the lever 25.

  An end portion (base end portion) 25A on the hook 21 side of the lever 25 is rotatably attached to the attachment end portion 17B. That is, the rod 22A is rotatably connected to the longitudinal intermediate portion of the lever 25, and the distal end portion (the end portion opposite to the proximal end portion) of the lever 25 is centered on the proximal end portion 25A toward the hook 21. When rotated, the rod 22 </ b> A and the eye 22 are moved toward the spring 23, and the eye 22 can be removed from the hook 21. On the contrary, when the lever 25 is rotated toward the hook 21 and the eye 22 is engaged with the hook 21, and then the lever 25 is rotated in the opposite direction to obtain the state of FIG. 2, the hook 21 moves toward the lever 25. The eye 22 is securely engaged with the hook 21, and the position of the bearing holding portion 17 is held at a predetermined position by the fastening mechanism 20.

  In the fastening mechanism of this embodiment, since the elastic member (spring 23) is connected to the engagement mechanism (hook 21, eye 22), the bearing holding portion 17 is fixed to the conveyor body 18 via the elastic member. Thereby, even if the eccentricity of the driving roller 14 or the thickness of the endless belt 11 changes, the size of the gap between the driving roller 14 and the nip bearings 15 and 16 is automatically adjusted by the expansion and contraction of the elastic member. Excessive pressing force is not applied to the endless belt 11, and it is possible to reduce the early wear of the endless belt 11 and the occurrence of failure in the rotation mechanism of the drive roller 14 and the nip bearings 15 and 16. As the elastic member, a leaf spring, rubber, or the like can be used in addition to the coil spring (tensile type or compression type). Note that the tension type is a type in which the nip bearings 15 and 16 are pressed against the driving roller 14 by the tension force of the spring as in the present embodiment. This is a type of pressing against the driving roller 14.

  Although not shown in FIG. 2, in the fastening mechanism 20, an adjustment mechanism for adjusting a fixed length in the fastening mechanism 20 is provided between the attachment end portion 17 </ b> B and the hook attachment portion 18 </ b> A. The adjustment mechanism may be configured such that, for example, a screw is provided at the tip of the rod 22A, and this is screwed to a bearing portion that engages with a shaft provided on the lever 25. Further, an adjusting screw may be provided between the spring 23 and the hook mounting portion 18A, or between the spring 23 and the fixing plate 24, or the position of the hook 21 relative to the fixing plate 24 or the mounting end portion 17A of the lever 25. It is good also as a structure which enables adjustment of the position with respect to.

  FIG. 3 is a graph showing changes in the slip torque of the belt when the fixed length of the fastening mechanism 20 of the present embodiment is shortened for Examples 1 to 3 using three different spring constants. On the other hand, Comparative Example 1 shows a change in slip torque when the fixing length is shortened in a conventional hook-type fastening mechanism in which no elastic member is provided. The spring constant increases in the order of Examples 1, 2, and 3.

  The horizontal axis of the graph indicates the magnitude of the adjustment length shortened by the adjustment mechanism provided in the fastening mechanism, and the vertical axis indicates the magnitude of the slip torque. That is, increasing the adjustment length acts in the direction of narrowing the gap between the nip bearing and the drive roller. The slip torque corresponds to the pressing force applied to the endless belt.

  As shown in the graph of FIG. 3, in the conventional hook type fastening mechanism in which no elastic member is provided, as the adjustment length becomes larger (as the gap becomes narrower), the amount is abruptly proportional to this. The slip torque (belt pressing force) increased. On the other hand, in Examples 1 to 3, the increase in slip torque was very gradual while the spring was elastically deformed.

  From the above, according to this embodiment, due to variations in component accuracy, even if the gap between the nip bearing and the drive roller changes, a substantially constant pressing force can be applied to the belt, and the belt and the rotation mechanism can be applied. A stable driving force can be applied to the belt without imposing a heavy burden.

  In the present embodiment, the configuration using two nip bearings has been described as an example. However, the present embodiment can also be applied to a case where three or more nip bearings are used. Further, the elastic member can be provided on the bearing holding portion side.

  In this embodiment, an elastic member (spring) is used as the urging means. However, for example, a weight can be used as the urging means. In other words, one end of the wire can be attached to the attachment end 17B, a weight can be attached to the other end of the wire, and the attachment end 17B can be biased upward by the weight of the weight via a pulley.

It is the typical of the whole belt conveyor using the nip bearing which is one Embodiment of this invention. It is an enlarged view of the fastening mechanism shown by FIG. It is a graph which shows the relationship between the adjustment length in Examples 1-3 and a comparative example, and slip torque.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Belt conveyor 11 Endless belt 20 Fastening mechanism 23 Spring (elastic member)
21 Hook 22 Eye 25 Lever 17 Bearing holding part 17B Mounting end (end of bearing holding part)
18 Conveyor body 18A Hook mounting part (part of conveyor body)

Claims (6)

A driving roller;
An endless belt,
A driving roller for transmitting a driving force to the endless belt;
First and second nip bearings for winding the endless belt is pressed against the endless belt to the drive roller to the driving roller,
A bearing holding portion for rotatably holding the first and second nip bearings;
A first engagement portion coupled to the bearing holding portion;
A second engagement portion detachably engaged with the first engagement portion and coupled to the conveyor body,
The state in which the first and second nip bearings are pressed against the driving roller via the endless belt is obtained by engaging the first engaging portion and the second engaging portion. And the pressing force of the endless belt to the driving roller by the first and second nip bearings is adjusted by a biasing means provided in the first or second engaging portion. Belt conveyor . The belt conveyor according to claim 1, wherein one end of the bearing holding portion is rotatably held by the conveyor body, and the first engagement portion is connected to the other end of the bearing holding member. . The belt conveyor according to claim 1, wherein the first or second engaging portion has a structure using a hook. The belt conveyor according to claim 1, wherein the urging means is made of an elastic member. The belt conveyor according to claim 4 , wherein the elastic member is a spring. 3. The first and second nip bearings are arranged side by side when the first and second nip bearings are pressed against the driving roller via the endless belt. The belt conveyor as described in.

Images