JP6498076B2 - Belt transmission for work vehicles - Google Patents

Description

  The present invention provides an endless V-belt configured such that spirally wound core wires are aligned in the belt width direction in the belt cross section, and a back surface on which the V-belt is wound and guides the back surface of the V-belt. The present invention relates to a belt-type power transmission device for a work vehicle including a pulley.

  As a belt-type transmission device provided in a combine which is an example of a work vehicle, for example, a variable diameter pulley that rotates a belt (V-belt) integrally with a processing cylinder, a pulley that rotates integrally with a handling cylinder, and a pulley for handling cylinder driving And a rear pulley is disposed between the pulley for driving the cylinder and the pulley for driving the cylinder and the belt sowing angle with respect to the pulley is increased (for example, (See paragraph No. 0013 of Patent Document 1 and FIG. 3). The belt includes a transmission pulley, a pulley that rotates integrally with the compressed air fan, a pulley that rotates integrally with the first screw conveyor, a pulley that rotates integrally with the second screw conveyor, and a pulley for driving the swinging sorter. And a rear pulley is disposed between the pulley and the transmission pulley to increase the spreading angle of the belt with respect to the pulley and the transmission pulley (for example, paragraph number of Patent Document 1) 0009, see FIG.

JP-A-6-98622

  In the belt type transmission device as described above, a flat pulley is adopted as the back pulley. In addition, as a V-belt, a high-load belt is provided in which a core wire formed by twisting a plurality of wires is wound inside a belt main body mainly made of rubber and spirally arranged in the belt width direction. The thing is adopted. As a result, the V-belt has a high strength that can withstand a high lateral pressure generated during transmission. On the other hand, if the tension acting on the V-belt becomes too large during transmission, a deviating force that causes the V-belt to be displaced from the predetermined belt line to one side in the belt width direction is generated inside the V-belt. Due to the offset force, the V-belt is shifted toward the one end in the width direction of the rear pulley with respect to the rear pulley at the belt guide location by the rear pulley. When such a deviation of the V-belt occurs, due to an increase in the lateral pressure of the V-belt on which the V-belt is offset, the V-belt is extended (twisted together) to the core portion located on the offset side. There is a possibility that the tension balance of the V-belt is broken in the belt width direction. When the tension balance is lost, the V-belt undulates and causes inconvenience of reversing or derailing.

  That is, it is desired to prevent the reverse and derailment of the V belt due to the deviation of the V belt from the back pulley.

As means for solving the above problems, a belt-type transmission device for a work vehicle according to the present invention includes:
An endless V-belt configured such that the spirally wound core wires are arranged in the belt width direction in the belt cross section, and a back pulley around which the V-belt is wound and which guides the back of the V-belt. ,
The guide surface of the guide pulley at the guide action position on the rear pulley is designed to resist the offset force generated by the cord along with the rotation of the V belt and acting on the V belt. Thus, the winding path length of the V belt on one end side in the belt width direction is different from the winding path length of the V belt on the other end side in the belt width direction.

  According to this means, at the guiding action position of the rear pulley relative to the V-belt, the winding path length (circumferential length) on one end side in the belt width direction of the V-belt and the winding path length (circumferential length) on the other end side in the belt width direction. ), And a drag force that can offset the offset force is obtained by a change in the tension balance in the belt width direction of the V belt at the guide action position obtained from the difference. be able to.

  As a result, it is possible to avoid the possibility that the V-belt is reversed or derailed due to the extension of the core portion located on the side where the V-belt is offset due to the deviation of the V-belt with respect to the rear pulley. The durability of the belt can be improved.

As one of the means to solve the problem more suitably,
The back pulley is a taper pulley whose diameter increases toward the other end in the belt width direction.

  According to this means, the winding path length (circumferential length) of the V-belt is positioned on the side opposite to the side where the V-belt is offset with respect to the tapered pulley by the above-mentioned offset force at the guide action position of the tapered pulley with respect to the V-belt. The other end side in the belt width direction of the V belt can be made longer than the one end side in the belt width direction of the V belt by the difference in the winding length of the V belt around the taper pulley.

  Thereby, the peripheral speed of the V belt at the guide action position of the taper pulley with respect to the V belt can be made faster at the other end side in the belt width direction of the V belt than at the one end side. The speed difference makes it possible to obtain a crown effect that brings the V-belt to the other side in the belt width direction, and the above-described offset force can be offset by the crown effect. And by this cancellation, the deviation of the V belt with respect to the taper pulley due to the deviation force can be prevented.

  As a result, it is possible to avoid the possibility that the V belt is reversed or derailed due to the extension of the core portion located on the side where the V belt is offset due to the deviation of the V belt relative to the rear pulley.

  That is, the durability of the V-belt can be improved with a simple configuration that simply employs a tapered pulley as the back pulley.

As one of the means to solve the problem more suitably,
The back pulley is a flat pulley;
The rotation axis of the flat pulley is inclined so as to intersect the direction orthogonal to the traveling direction of the V-belt.

  According to this means, at the guide action position of the flat pulley relative to the V-belt, the winding path length (circumferential length) of the V-belt is located on the side where the V-belt is offset from the flat pulley by the above-mentioned offset force. If the rotation axis of the flat pulley is inclined so that the one end side in the belt width direction is longer than the other end side, the flat pulley is moved from one side of the belt width direction of the V belt to the flat pulley. It can be equipped with an inclined posture that allows sliding to the other side in the width direction. Further, the restoring force in the belt winding direction by the elasticity of the V belt obtained at the guide action position of the flat pulley relative to the V belt can be made larger at one end side in the belt width direction of the V belt than at the other end side.

  As a result, at the guide action position of the flat pulley relative to the V belt, it is possible to obtain a sliding force that slides the V belt from one side to the other side in the belt width direction with respect to the flat pulley. It becomes possible to cancel the force. And by this cancellation, the deviation of the V belt with respect to the flat pulley due to the deviation force can be prevented.

  As a result, it is possible to avoid the possibility that the V belt is reversed or derailed due to the extension of the core portion located on the side where the V belt is offset due to the deviation of the V belt relative to the rear pulley.

  That is, the durability of the V-belt can be improved while employing an inexpensive flat pulley as the back pulley.

As one of the means to solve the problem more suitably,
A V pulley around which the V belt is wound at a position continuous with the rear pulley in the belt rotation direction;
An auxiliary V pulley is provided in a linear path between the back pulley and the V pulley in the V belt to prevent the back belt from shifting in the belt width direction of the V belt.

  According to this means, the deviation of the V belt with respect to the rear pulley can be more reliably prevented. Thereby, due to the deviation of the V belt relative to the rear pulley, it is possible to more reliably avoid the possibility that the V belt is reversed or derailed due to the extension of the core portion located on the side where the V belt is offset.

It is a left view of a self-decomposing combine. It is the schematic of the transmission system in a self-decomposing combine. It is a vertical left side view of a threshing apparatus. It is a left view of the principal part of the threshing apparatus which shows structures, such as a 7th belt type transmission apparatus. It is a vertical rear view of the principal part of the 7th belt type transmission which adopted a flat pulley as a back pulley. It is a left view of the principal part of the threshing apparatus which shows the structure of an urging | biasing mechanism. It is a vertical left side view of the principal part of the threshing apparatus which shows the support structure of the front end part of a barrel. It is a vertical rear view of the principal part of the 7th belt type power transmission in another embodiment which adopted the taper pulley as the back pulley.

  Hereinafter, as an example of a form for carrying out the present invention, an embodiment in which a belt-type transmission device for a work vehicle according to the present invention is applied to a self-removing combine that is an example of a work vehicle will be described with reference to the drawings.

  The direction indicated by the arrow F in FIG. 1 is the front side of the self-removing combine, and the direction indicated by the arrow U is the upper side of the self-removing combine.

  As shown in FIGS. 1 and 2, the self-removing combine exemplified in this embodiment includes a vehicle body frame 1 that forms a framework of the vehicle body, left and right crawler travel devices 2 attached to the lower part of the vehicle body frame 1, and during work travel. The harvesting and transporting device 3 that harvests the planted cereal and conveys it backward, the threshing device 4 that performs the threshing / sorting process on the harvested cereal from the harvesting and conveying device 3, and the grain tank 5 that stores the grain from the threshing device A screw conveying type grain discharging device 6 for discharging the grain in the grain tank to the outside of the machine, a control part 7 for boarding operation, an engine 8 located at the rear lower part of the control part 7, and the engine 8 A transmission unit 9 for shifting power is provided.

  As shown in FIGS. 1 to 3, the threshing device 4 includes a sandwiching conveyance mechanism 10 that conveys the harvested cereal meal backward, a handling cylinder 11 that performs a threshing process on the tip side of the harvested grain meal carried by the clamping conveyance mechanism 10, and threshing The swinging selection mechanism 12 that screens and sorts the sorting object obtained by the processing while moving backward, and the action of the sorting object accumulated on the plurality of sieve lines 12A provided on the rear upper part of the shaking sorting mechanism 12 is solved. Diffusion cylinder 13 to be applied, Kara 14 supplying sorting air to the object to be sorted, Dust exhaust fan 15 for sucking and discharging the waste dust and the like wind-carrying upward by the sorting wind from Kara 14, and the sorting process The first screw 16 that conveys the single-grained grains obtained in step 1 to the right, the second screw 17 that conveys branch-attached or bifurcated grains obtained by the sorting process to the right, the first screw 16 Feed conveyor to feed grain kernel 5 No. 8 and No. 2 reduction mechanism 19 that applies branching treatment to branch swinging grains or No. 2 grains from No. 2 screw 17 and returns to swinging selection mechanism 12 and finely harvested cereal meal after threshing processing A shredding mechanism 20 for cutting is provided.

  As shown in FIG. 2, the self-removing combine is a belt-type transmission device in which a first belt-type transmission device A <b> 1 that transmits power from the engine 8 to the transmission unit 9 and a second belt that transmits power from the transmission unit 9 to the cutting and conveying device 3. A fourth belt type transmission that is transmitted from the transmission shaft A2 that is linked to the counter shaft 21 via a pair of bevel gears 22 to the handle cylinder 11, and a third belt transmission A3 that is transmitted from the engine 8 to the counter shaft 21. Device A4, fifth belt type transmission device A5, which is transmitted from counter shaft 21 to Karatsu 14, and sixth belt type transmission device A6, which is transmitted from counter shaft 21 to first screw 16, and second screw 17 from first screw 16 The seventh belt type transmission device A7, which is transmitted to the body 13 and the input shaft 24A of the gear type transmission device 24, is moved from the seventh belt type transmission device A7 to the swing sorting mechanism 12. Eighth belt transmission device A8 for moving, and includes ninth belt transmission A9, and that transmission to the shredding mechanism 20 from the input shaft 24A of the gear-type transmission apparatus 24.

  As shown in FIGS. 2 and 4, the self-decomposing combine is configured such that the fifth to ninth belt-type transmission devices A <b> 5 to A <b> 9 are arranged on the left side wall 4 </ b> A of the threshing device 4 located at the left end of the vehicle body. It is deployed along the outer surface of 4A. Thereby, the maintenance with respect to each of the fifth to ninth belt-type transmission devices A5 to A9 can be easily performed from the left outer side of the vehicle body.

  The seventh belt type transmission A7 rotates integrally with the first V pulley 25 that rotates integrally with the first screw 16, the second V pulley 26 that rotates together with the second screw 17, and the input shaft 24A of the gear type transmission 24. A third V pulley 27, a fourth V pulley 28 that rotates integrally with the diffusion cylinder 13, an endless V belt 29 wound around each of the V pulleys 25 to 28, a first guide pulley 30 having a V groove and a second A guide pulley 31, a first back pulley 32 and a second back pulley 33 that guide the back of the V belt 29, a tension pulley 34 that maintains the V belt 29 in a tension state, and the like are provided.

  The first V pulley 25 is a drive pulley that rotates the V belt 29 counterclockwise as viewed from the left side of the vehicle body. And the 1st V pulley 25 is located in the front-back intermediate position of the lower part in the threshing apparatus 4. FIG. The second V pulley 26 is located behind the first V pulley 25. The third V pulley 27 is located on the vehicle rear side of the second V pulley 26 and on the vehicle body upper side of the second V pulley 26. The fourth V pulley 28 is located on the vehicle front side of the second V pulley 26 and on the vehicle body side of the second V pulley 26.

  The first guide pulley 30 is located between the first V pulley 25 and the fourth V pulley 28 having a long separation distance. The first guide pulley 30 includes an inspection port 4B provided between the first V pulley 25 and the fourth V pulley 28 in the left side wall 4A of the threshing device 4, and a cover for closing the inspection port 4B so as to be opened and closed. It is located near the middle position between the first V pulley 25 and the fourth V pulley 28 on the vehicle body side above 4C. Accordingly, the long belt portion between the first V pulley 25 and the fourth V pulley 28 in the V belt 29 without hindering the maintenance of the swing sorting mechanism 12 in the threshing device from the inspection port 4B. Can be appropriately guided and supported by the first guide pulley 30. As a result, the swell of the V belt 29 that may occur between the first V pulley 25 and the fourth V pulley 28 having a long separation distance when the V belt 29 is rotated can be suppressed. The reverse of the V belt 29 can be prevented.

  The second guide pulley 31 is located between the first V pulley 25 and the second V pulley 26. The first back pulley 32 is located between the third V pulley 27 and the fourth V pulley 28 to increase the winding angle of the V belt 29 around the third V pulley 27 and the fourth V pulley 28. . The second back pulley 33 is located between the second V pulley 26 and the second guide pulley 31 to increase the winding angle of the V belt 29 around the second V pulley 26 and the second guide pulley 31. . The tension pulley 34 is located between the first V pulley 25 and the second guide pulley 31 and increases the winding angle of the V belt 29 with respect to the first V pulley 25 and the second guide pulley 31. 29 is kept in tension.

  As shown in FIG. 5, the V-belt 29 is formed by winding a core wire 29B formed by twisting a plurality of wires into a spiral shape aligned in the belt width direction inside a belt main body 29A mainly composed of rubber. By providing in the state where it was, it has the high intensity | strength which can endure the high side pressure which generate | occur | produces at the time of transmission. On the other hand, when the tension acting on the V-belt 29 during transmission is excessively large, the offset force that biases the V-belt 29 from the predetermined belt line to one side in the belt width direction (the left side of the vehicle body in this embodiment). F1 is generated inside the V-belt 29, and due to this offset force F1, the V-belt 29 is at one end in the width direction of the first backside pulley 32 with respect to the first backside pulley 32 at the belt guide location by the first backside pulley 32. Deviation of the V-belt 29 that is shifted to the side (left end side) occurs. When such a deviation of the V-belt 29 occurs, the lateral pressure of the left V-belt 29 from which the V-belt 29 is offset increases, and the stretched (twisted) portion of the core wire located on the left-hand side of the V-belt 29 There is a possibility that the tension balance of the V-belt 29 is broken in the belt width direction. When the tension balance is lost, the V belt 29 undulates, causing inconvenience of reversing or derailing.

  Therefore, in the seventh belt type transmission device A7, a flat pulley 32A is adopted as the first back pulley 32, and the rotation axis X of the flat pulley 32A is in a direction perpendicular to the traveling direction of the V belt 29. By inclining so as to intersect, the winding surface length of the V belt 29 at one end side in the belt width direction and the length of the V belt 29 at the other end side in the belt width direction are guided by the guide surface 32a at the guide action position in the flat pulley 32A. The winding path length is different.

Specifically, the flat pulley 32A is positioned between the third V pulley 27 and the fourth V pulley 28 so that the back surface of the V belt 29 is wound around the lower half thereof. And the spindle 35 which supports the flat pulley 32A so that relative rotation is possible is extended from the left side wall 4A of the threshing device 4 to the left in a horizontal posture. The support shaft 35 is fixedly equipped with a collar 35A that tilts the rotation axis X of the flat pulley 32A downwardly at a predetermined angle.
Thereby, the flat pulley 32A is allowed to slide from the left side to the right side of the V belt 29 with respect to the flat pulley 32A on the lower side of the flat pulley 32A, which is the guide action position of the flat pulley 32A with respect to the V belt 29. It can be provided on the left side wall 4A of the threshing device 4 in a tilted posture to the left.
Further, the winding path length (circumferential length) of the V-belt 29 is set to the side (left side) on which the V-belt 29 is offset from the flat pulley 32A by the offset force F1 on the guide surface 32a at the guide action position in the flat pulley 32A. The one end side (left end side) in the belt width direction of the V belt 29 positioned at the position can be longer than the other end side (right end side) in the belt width direction. Thereby, the restoring force in the winding direction by the elasticity of the V belt 29 obtained at the guiding action position of the flat pulley 32 </ b> A with respect to the V belt 29 can be made larger on the left end side of the V belt 29 than on the right end side.
As a result, at the guiding action position of the flat pulley 32A with respect to the V belt 29, it is possible to obtain a sliding force F2 that causes the V belt 29 to slide to the right with respect to the flat pulley 32A. It becomes possible to cancel. This offset can prevent the deviation of the V belt 29 with respect to the flat pulley 32A due to the deviation force F1, and due to this deviation, the core portion located on the left side of the V belt 29 is stretched. It is possible to avoid the possibility that the V belt 29 is reversed or derailed.

  As shown in FIGS. 4 and 5, the flat pulley 32 </ b> A supports the extension end of the support shaft 35 with a support member 4 </ b> G fixed to the left side wall 4 </ b> A of the threshing device 4, thereby The wall 4A can be provided in a stable support state.

As shown in FIG. 4, the seventh belt type transmission device A <b> 7 has a belt of the V belt 29 in the first back pulley 32 in a linear path between the first back pulley 32 and the third V pulley 27 in the V belt 29. A first auxiliary V pulley 36 is provided to prevent lateral displacement. Further, the seventh belt type transmission device A7 is shifted to the linear path between the first back pulley 32 and the fourth V pulley 28 in the V belt 29 in the belt width direction of the V belt 29 in the first back pulley 32. A second auxiliary V pulley 37 is provided.
Accordingly, the displacement of the V belt 29 with respect to the first back pulley 32 can be more reliably prevented. As a result, due to the deviation of the V-belt 29 relative to the first back pulley 32, there is more sure that the V-belt 29 may be reversed or derailed due to the extension of the core wire portion located on the left side where the V-belt 29 is offset. It can be avoided.

In the seventh belt type transmission device A7, the position of the V belt 29 with respect to the first V pulley 25 is set at the adjacent position on the upper side in the belt rotation direction with respect to the first V pulley 25, and the inner peripheral portion of the V belt 29 is the first V A retainer 38 is provided that holds the pulley 25 in an appropriate posture to enter the V groove.
As a result, the undulation of the V-belt 29 can be prevented at an adjacent location on the upper side in the belt rotation direction with respect to the first V pulley 25, and the reverse and derailment of the V-belt 29 due to the undulation at this location can be prevented. be able to. As a result, the driving of the V belt 29 by the first V pulley 25 can be performed satisfactorily.

  The retainer 38 is attached to the first support 4D provided on the left side wall 4A of the threshing device 4. The retainer 38 is made of a round bar steel material bent into an L shape. The retainer 38 holds the V belt 29 in an appropriate posture with respect to the first V pulley 25 by the extension portion 38A extending leftward from the first support portion 4D acting on the back surface of the first V pulley 25. doing.

  As the retainer 38, a roller or a flat pulley acting on the back surface of the first V pulley 25 may be adopted.

  As shown in FIGS. 4 and 6, the seventh belt-type transmission device A <b> 7 includes a swing arm 39 that swings about the support shaft 16 </ b> A of the first screw 16. A tension pulley 34 is provided at the free end of the swing arm 39.

The seventh belt type transmission device A7 includes a biasing mechanism 40 that swings and biases the tension pulley 34 in a direction to maintain the V belt 29 in a tensioned state. The biasing mechanism 40 includes a female screw member 41 received and supported by the second support portion 4E provided on the left side wall 4A of the threshing device 4, an adjustment bolt 42 having a male screw portion 42A that can be screwed into the female screw member 41, and And a tension spring 43 extending from one end of the adjustment bolt 42 to the free end of the swing arm 39.
Thereby, the biasing mechanism 40 operates the female screw member 41 to adjust the extension amount of the adjusting bolt 42 from the female screw member 41 received by the second support portion 4E of the threshing device 4. The tension of the V belt 29 can be adjusted.

  The adjusting bolt 42 is provided with a hooking portion 42B capable of hooking one end portion of the tension spring 43 at one end portion thereof by forming one end portion into a wide plate shape and performing drilling. The swing arm 39 is provided with a hook portion 39A capable of hooking the other end portion of the tension spring 43 at the free end portion by drilling the free end portion.

The urging mechanism 40 includes a restricting tool 44 that prevents the tension spring 43 from being over tensioned by the operation of the female screw member 41. The restricting tool 44 includes, at one end thereof, a ring portion 44A that allows the male screw portion 42A to be inserted into the adjustment bolt 42 and receives the hooking portion 42B. The restricting tool 44 includes a hook portion 44B that can be hooked on the hook portion 39A of the swing arm 39 at the other end.
Thus, the female screw member 42A is inserted in the state where the male screw portion 42A of the adjustment bolt 42 is inserted into the ring portion 44A of the restricting tool 44 and the hook portion 44B of the restricting tool 44 is hooked on the hook portion 39A of the swing arm 39. When the spring tensioning operation for shortening the extension amount of the adjustment bolt 42 from the female screw member 41 is performed by the operation of 41, the tension bolt 43 of the tension bolt 43 reaches an appropriate amount by this operation. When the hook portion 42B comes into contact with the ring portion 44A of the restricting tool 44, the spring tension operation by the female screw member 41 is prevented. As a result, excessive tension of the tension spring 43 due to the operation of the female screw member 41 can be reliably prevented.
Further, when the V belt 29 is stretched due to long-term use, the tension spring 43 contracts in accordance with the stretch amount, so that the larger the stretch amount of the V belt 29 is, the larger the ring portion of the restrictor 44 is. Since 44A leaves | separates from the hook part 42B of the adjustment bolt 42, extension of the V belt 29 can be visually recognized easily. When the extension of the V belt 29 is visually confirmed, the tension adjustment of the V belt 29 according to the extension of the V belt 29 can be easily performed by performing a spring tension operation with the female screw member 41. .

  As shown in FIGS. 3 and 7, the handling cylinder 11 has a small-diameter portion 11a at the front end portion of the rotation support shaft 11A. And the handling cylinder 11 equips the small diameter part 11a with the output pulley 45 of 4th belt type transmission device A4 so that integral rotation is possible. Moreover, the small diameter part 11a of the handling cylinder 11 is supported by the support unit 46 with which the vertical wall 4F of the threshing apparatus 4 was equipped.

  As shown in FIG. 7, the support unit 46 includes a holder 47 that is bolted to the vertical wall 4 </ b> F of the threshing device 4, a bearing 48 that fits inside the holder 47, and a collar 49 that is interposed between the holder 47 and the bearing 48. , Etc.

The collar 49 has a longitudinal length that extends between the small diameter portion 11a and the large diameter portion 11b of the rotation support shaft 11A. The collar 49 has a large contact area between the front surface 49A of the collar 49 and the back surface 48A of the bearing 48 by increasing the outer diameter of the front end portion thereof. Further, the collar 49 has a large contact area between the inner peripheral surface 49B of the collar 49 and the peripheral surface of the large diameter portion 11b by increasing the fitting length of the rotary support shaft 11A with the large diameter portion 11b. .
Thereby, in order to reduce the weight of the handling cylinder 11, the step between the small diameter portion 11a and the large diameter portion 11b in the rotation support shaft 11A is reduced by reducing the diameter of the large diameter portion 11b of the rotation support shaft 11A. However, due to the action of the collar 49, the rotation support shaft 11A can be supported by the bearing 48 with good stability.
As a result, while the weight of the handling cylinder 11 is reduced, there is a risk that the handling cylinder 11 may be driven to rotate due to a small step between the small-diameter portion 11a and the large-diameter portion 11b of the rotation support shaft 11A. Fretting between the rotating support shaft 11A and the bearing 48 can be prevented, and wear of the rotating support shaft 11A or the bearing 48 due to fretting can be prevented.

[Another embodiment]
The present invention is not limited to the configuration exemplified in the above embodiment, and a typical alternative embodiment of the present invention will be exemplified below.

[1] The belt-type transmission of the work vehicle according to the present invention may be, for example, a belt-type continuously variable transmission including a split pulley that enables a change in the winding diameter of the V-belt 29.

[2] In the seventh belt type transmission A7, the flat pulley 32A can be relatively rotated in order to incline the rotation axis X of the flat pulley 32A employed as the first back pulley 32 downward to the left at a predetermined angle. The supporting shaft 35 to be supported may be extended to the left from the left side wall 4A of the threshing device 4 in a left-down posture.
This eliminates the need for the collar 35A that tilts the rotation axis X of the flat pulley 32A downwardly at a predetermined angle.

[3] As shown in FIG. 8, in the seventh belt type transmission device A <b> 7, a taper pulley 32 </ b> B having a larger diameter toward the right end side in the belt width direction may be employed as the first back pulley 32.
According to this configuration, the winding path length (circumferential length) of the V-belt 29 is set such that the V-belt 29 is offset from the tapered pulley 32B by the above-described offset force F1 at the guide action position of the tapered pulley 32B with respect to the V-belt 29. Can be made longer by the difference in the winding length of the V belt 29 around the taper pulley 32B than the left end side in the belt width direction of the V belt 29 toward the right end side in the belt width direction of the V belt 29 located on the opposite side.
Thereby, the peripheral speed of the V belt 29 at the guide action position of the taper pulley 32 </ b> B relative to the V belt 29 can be made faster toward the right end side in the belt width direction of the V belt 29 than at the left end side. The speed difference makes it possible to obtain a crown effect that brings the V-belt 29 toward the right side, which is the other side in the belt width direction, and this crown effect produces a drag force F2 that can offset the above-described offset force F1. Can be obtained. And by this cancellation, the offset of the V belt 29 with respect to the taper pulley 32B due to the offset force F1 can be prevented.
As a result, it is possible to avoid the possibility that the V-belt 29 is reversed or derailed due to the extension of the core portion located on the side where the V-belt 29 is offset due to the deviation of the V-belt 29 with respect to the first back pulley 32. Can do.

[4] In the seventh belt type transmission device A7, due to excessive tension acting on the V-belt 29 during transmission, the offset that causes the V-belt 29 to be offset from the predetermined belt line to the right side in the belt width direction. A force F <b> 1 is generated inside the V-belt 29, and this offset force F <b> 1 causes the V-belt 29 to move to the right end side of the first back pulley 32 with respect to the first back pulley 32 at the belt guide location by the first back pulley 32. For example, when the V belt 29 is offset, the flat pulley 32A is employed as the first back pulley 32, and the rotational axis X of the flat pulley 32A is lowered to the right at a predetermined angle. You may make it incline. For example, as the first back pulley 32, a taper pulley 32B having a larger diameter toward the left end side in the belt width direction may be employed.

[5] At the belt guide location (the upper half portion of the second back pulley 33) by the second back pulley 33, the V belt 29 is moved against the second back pulley 33 by the offset force F1 described above. For example, a flat pulley is used as the second back pulley 33, and the rotational axis of the flat pulley is By inclining so as to intersect the direction perpendicular to the traveling direction of the V-belt 29 (inclining downward to the right at a predetermined angle), the flat pulley becomes a guide action position of the flat pulley with respect to the V-belt 29. The left side wall 4A of the threshing device 4 may be provided in a right tilting posture that allows the V belt 29 to slide from the left side to the right side with respect to the flat pulley. Further, for example, a taper pulley having a larger diameter toward the right end side in the belt width direction may be employed as the second back surface pulley 33.

[6] A core wire in which one of the first belt type transmission device A1 to the sixth belt type transmission device A6, the seventh belt type transmission device A7, and the eighth belt type transmission device A8 is spirally wound is provided. It has an endless V-belt provided inside so as to be lined up in the belt width direction, and a back pulley that guides the back of the V-belt, so that the tension acting on the V-belt during transmission becomes too large. Due to the above, a deviation force F1 that causes the V belt to be displaced from the predetermined belt line to one side in the belt width direction is generated inside the V belt, and this deviation force F1 causes the V belt at the belt guide location by the rear pulley. When the belt is displaced toward one end in the belt width direction of the rear pulley relative to the rear pulley, or when the V belt is displaced, for example, as the rear pulley of the belt type transmission device A pulley may be employed, and the rotation axis of the flat pulley may be inclined at a predetermined angle at which an appropriate sliding force F2 with respect to the offset force F1 can be obtained at the guide action position of the flat pulley with respect to the V belt. . Further, for example, as a rear pulley of the belt type transmission device, a taper pulley having a larger diameter toward the other end in the belt width direction so as to obtain an appropriate resistance F2 against the offset force F1 at the guide action position of the taper pulley with respect to the V belt. It may be adopted.

[7] The seventh belt type transmission device A7 may be configured not to include all of the first guide pulley 30, the first auxiliary V pulley 36, the second auxiliary V pulley 37, and the retainer 38, The configuration may include at least one of them.

  The present invention relates to a self-removing combine, a normal type (all-throw-up type) having a belt-type transmission device having an endless V-belt having a core wire therein and a back pulley that guides the back of the V-belt. ) Applicable to work vehicles such as combine, corn harvester, carrot harvester, tractor, rice transplanter.

27 V pulley (third pulley)
28 V pulley (fourth V pulley)
29 V belt 29B Core wire 32 Rear pulley (first rear pulley)
32A Flat pulley 32B Taper pulley 32a Guide surface 36 Auxiliary V pulley (first auxiliary V pulley)
37 Auxiliary V pulley (second auxiliary V pulley)
F1 offset force X rotation axis

Claims (4)

An endless V-belt configured such that the spirally wound core wires are arranged in the belt width direction in the belt cross section, and a back pulley around which the V-belt is wound and which guides the back of the V-belt. ,
The guide surface of the guide pulley at the guide action position on the rear pulley is designed to resist the offset force generated by the cord along with the rotation of the V belt and acting on the V belt. A belt-type power transmission device for a work vehicle in which the winding path length of the V belt on one end side in the belt width direction is different from the winding path length of the V belt on the other end side in the belt width direction.   The belt-type power transmission device for a work vehicle according to claim 1, wherein the rear pulley is a tapered pulley having a larger diameter toward the other end in the belt width direction. The back pulley is a flat pulley;
The belt-type power transmission device for a work vehicle according to claim 1, wherein a rotation axis of the flat pulley is inclined so as to intersect with a direction orthogonal to a traveling direction of the V-belt. A V pulley around which the V belt is wound at a position continuous with the rear pulley in the belt rotation direction;
The auxiliary V pulley which prevents the deviation of the belt width direction of the V belt in the back pulley in the straight path between the back pulley and the V pulley in the V belt. A belt-type power transmission device for a work vehicle according to claim 1.

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