JP4414822B2 - Transmission belt pulley and belt transmission device - Google Patents

Description

  The present invention relates to a pulley for a transmission belt and a belt transmission device.

  In a transmission device using a flat belt, the flat belt may meander while the vehicle travels, or may travel offset by moving toward one side of the pulley. This is because the flat belt is more sensitive to changes in the components of the transmission device, such as the displacement of the pulley shaft from its normal position, the deflection of the pulley shaft due to changes in shaft load, and the vibration of the pulley, compared to other transmission belts. It is. When such meandering / offset running occurs, the flat belt comes into contact with the flange of the flat pulley, causing fuzz on the side surface of the flat belt and fraying of the core.

  In order to solve this problem, it is known to attach a crown to the outer peripheral surface of the flat pulley (form a medium-high curved surface). There is also a proposal that the crown on the outer peripheral surface of the pulley is formed in a spherical shape centered on the rotation center of the pulley (see Patent Document 1). This is because when there is a tension difference between the left and right sides of the flat belt and the pulley shaft is tilted, and the flat belt is offset on the pulley, a rotational moment acts on the pulley due to the tension of the flat belt. By utilizing this, the inclination of the pulley shaft and the meandering of the flat belt are eliminated.

  Moreover, what formed many groove | channels in the outer peripheral surface of the flat pulley at intervals in the circumferential direction is known (refer patent document 2). In other words, the groove extends symmetrically from the center of the width of the pulley so as to form a “<” shape on both sides, and a frictional force that moves the flat belt to the center between the flat belt and the pulley. By generating the belt, meandering of the belt is prevented.

Furthermore, it is also known that guide rollers are arranged on both sides of the flat belt to restrict the travel position of the flat belt (see Patent Document 3).
Japanese Utility Model Publication No.59-45351 JP-A-6-307521 Japanese Utility Model Publication No. 63-6520

  However, when the crown is formed on the pulley, if the radius of curvature of the crown is reduced with an emphasis on the running stability of the flat belt (preventing meandering and shifting), the stress concentrates in the center of the belt width, and the belt width The whole cannot be used effectively for transmission, leading to early fatigue of the core and a reduction in transmission capability.

  Further, when the pulley crown is formed in a spherical shape centered on the rotation center of the pulley, even if the effect of preventing the meandering of the transmission belt is enhanced, the problem is that stress is concentrated at the center of the belt width by the pulley crown. Still remains.

  Further, if the flat pulley is grooved as described above, the manufacturing cost of the flat pulley is increased, and it is difficult to reliably prevent the flat belt from meandering only by the groove processing.

  Furthermore, if a method of restricting the running position by arranging guide rollers or the like on both sides of the flat belt, both sides of the flat belt will always come into contact with such a restricting member. Line fraying is likely to occur. Therefore, it is necessary to specially process the flat belt for preventing them, which is disadvantageous in reducing the production cost of the flat belt.

  For these reasons, flat belt transmissions are not fully utilized despite the fact that they have less loss due to belt bending and very high transmission efficiency compared to other belts such as V-belts. It is.

  Accordingly, the present invention is intended to ensure that the meandering of the flat belt and other transmission belts can be reliably prevented so that the belt transmission device can be effectively used for various industrial machines and other devices. is there.

  According to the present invention, when the transmission belt is displaced, the pulley is displaced by utilizing the fact that the position of the axial load applied to the pulley shaft is changed by the tension of the transmission belt, thereby preventing the transmission belt from meandering. I made it.

  Furthermore, the present invention uses a mechanism that prevents the transmission belt from meandering and moves the transmission belt on the pulley in the pulley axial direction, thereby making it possible to change the running position of the belt.

  That is, the pulley for a transmission belt of the present invention includes a pulley body around which the transmission belt is wound, and a support means for supporting the pulley body so as to be rotatable about a pulley axis and swingable about a predetermined pivot axis, The pivot is tilted at a predetermined tilt angle to the front of the pulley body in the rotational direction with respect to the direction of the axial load when viewed along the pulley axis direction, and the support means is configured to move the pivot to the pulley. It is configured to be able to reciprocate in the pulley axis direction within the pulley width of the main body.

  According to this transmission belt pulley, in a state where the pivot is stationary with respect to the pulley axis direction, the transmission belt is displaced in the pulley axis direction with respect to the pivot axis, so that the axial load is shifted from the pivot position to the pulley body width direction. As a result, the rotational load about the pivot acts on the pulley body, and the pulley body is rotationally displaced about the pivot.

  At this time, as will be described in detail later, the pivot shaft is tilted at a predetermined tilt angle forward of the pulley body in the rotation direction with respect to the axial load direction when viewed along the pulley shaft direction. When the angle is 90 degrees, the pulley body is inclined so that the side opposite to the side where the axial load is shifted with respect to the pivot is high, and when the tilt angle is greater than 0 degree and less than 90 degrees The pulley body not only inclines, but also enters an oblique state in which the side on which the axial load is shifted from the pivot is the front side in the belt traveling direction.

  Due to the inclination and / or crossing of the pulley body, a force from the pulley body to the transmission belt acts on the pivot axis, and the transmission belt moves to the position of the pivot.

  That is, when the axial load is applied to the position of the pivot, the pulley body is balanced without any rotational moment acting. Therefore, in the transmission belt pulley, the transmission belt travels at the position of the pivot, and as a result, the transmission belt is prevented from meandering.

  The above is a case where the transmission belt moves in the pulley axis direction while the pivot is stationary, but when the pivot is moved in the pulley axis direction, the axial load is shifted from the position of the pivot. Become. Due to the axial load, as described above, the pulley main body is rotationally displaced about the pivot, and a force from the pulley main body to the transmission belt acts on the pivot. As a result, the transmission belt travels at the position of the pivot after movement. That is, the travel position of the transmission belt is changed by changing the position of the pivot shaft in the pulley axis direction within the pulley width of the pulley body. As described above, the transmission belt pulley moves the transmission belt by a force acting from the pulley body, and does not forcibly move the traveling position of the transmission belt by hitting the flange, for example. The pulley body does not require a flange. In other words, there is no decrease in belt life due to flange contact.

  Accordingly, the transmission belt pulley can change the traveling position of the transmission belt by moving the pivot while preventing the transmission belt from meandering in a state where the pivot is stationary. It can be used for various belt transmission devices including mechanisms.

  It is preferable that the tilt angle of the pivot is set in an angle range exceeding 0 degree and not exceeding 90 degrees.

  When the tilt angle is 90 degrees, that is, when the pivot is perpendicular to the axial load direction, the pulley body is rotationally displaced so that the side on which the transmission belt is displaced from the pivot moves in the axial load direction. Will do. In other words, when the height is seen in the axial load direction, the side where the transmission belt is displaced across the pivot is inclined so that the opposite side is high and the opposite side is high. In other words, the outer peripheral surface of the pulley body is inclined in the same manner as the crown. As a result, a force in a direction opposite to the direction deviated from the pivot is applied to the transmission belt.

  When the tilt angle is less than 90 degrees, the rotational displacement of the pulley main body when the transmission belt is displaced with respect to the pivot axis includes not only the component in the axial load direction but also the longitudinal direction perpendicular to the axial load direction ( A component in the direction in which the transmission belt is running in contact with the pulley body is added. That is, the pulley body is not only inclined in the axial load direction but also in contact with the transmission belt in an oblique manner.

  Thus, since the pivot is tilted forward in the rotational direction of the pulley body with respect to the axial load direction, when the transmission belt is deviated from the pivot, the pulley body moves on the side where the transmission belt is displaced. It becomes the diagonal state which became the front side of the direction. By rotating the pulley body in an oblique state, the transmission belt is given a force in a direction that eliminates the deviation from the pulley body.

  Eventually, when the tilt angle is greater than 0 degree and less than 90 degrees, when the transmission belt is displaced with respect to the pivot, the pulley body has a height difference in the axial load direction. Both the force caused by the inclination to occur and the force caused by the pulley body being oblique to the transmission belt work.

  Of the force due to the inclination and the force due to the diagonal, the latter has a higher effect of moving the belt.

  Therefore, it is preferable that the tilt angle is more than 0 degree and less than 90 degrees. More preferably, the tilt angle is set to more than 0 degree and not more than 45 degrees in order to effectively use the force due to the oblique crossing. On the other hand, when the tilt angle is close to 0 degrees, it becomes difficult to generate a rotational moment about the above-mentioned pivot axis. Therefore, it is more preferable that the tilt angle is 5 degrees or more and 45 degrees or less, or 10 degrees or more and 30 degrees or less.

  Thus, the fact that the transmission belt can be moved effectively by setting the tilt angle to more than 0 degrees and less than 90 degrees is equivalent to the fact that the driving position of the transmission belt can be switched effectively. .

  It is preferable that the pulley body has a width over two or more belt travel positions aligned in the pulley axis direction, and the support means is configured to position the pivot at each belt travel position.

  According to this configuration, the transmission shaft travels at each of the two or more travel positions by positioning the pivot at each of the two or more belt travel positions. Therefore, it is advantageous when used for various belt transmission devices including a clutch mechanism, a transmission mechanism, and the like.

  The support means is provided integrally with the pulley main body, and is a cylindrical shaft member that rotatably supports the pulley main body around the pulley shaft, and is inserted into the cylindrical shaft member, and the pulley A support rod extending coaxially with the shaft, a pin supported so as to be reciprocable in the axial direction with respect to the support rod, and a pin for supporting the shaft member together with the pulley body so as to be swingable with respect to the support rod; And a power source that generates power for reciprocating the pin.

  According to this configuration, when the pin is moved in the axial direction of the support rod by the power generated by the power source, the axial load is shifted with respect to the pivot, and the pulley body is rotationally displaced around the pin. The force acts on the transmission belt in such a direction that the deviation disappears. Then, the transmission belt follows the pin movement and moves in the pulley axis direction.

  As the power source, various power sources such as a vacuum cylinder, a motor, a linear motor, a solenoid, and a hydraulic cylinder can be adopted.

  The belt transmission device of the present invention includes the transmission belt pulley, the driving pulley, the driven pulley, and the transmission belt pulley, the driving pulley, and the driving belt wound around the driving pulley. It is a device equipped.

  Therefore, in a state where the pivot shaft of the transmission belt pulley is stationary with respect to the pulley axial direction, the transmission belt can be prevented from meandering while applying a stable tension to the transmission belt, and the transmission belt transmission capability can be reduced. It will be advantageous for full use.

  On the other hand, since the travel position of the transmission belt can be switched by moving the pivot shaft of the transmission belt pulley in the pulley axis direction, the belt transmission device is a device including a speed change mechanism and a clutch mechanism. Can do.

  Here, one of the driving pulley and the driven pulley may include a plurality of pulleys arranged in parallel in the rotation axis direction and having substantially the same outer peripheral surface.

  That is, if any one of the plurality of pulleys is a clutch pulley and the other pulley is a power transmission pulley, the belt transmission device is a device having a clutch mechanism. Further, if the plurality of pulleys are pulleys having different speed ratios, the belt transmission device is a device including a speed change mechanism.

  Thus, the belt transmission device disengages and shifts the power transmission by displacing the transmission belt between the plurality of pulleys, so that an electromagnetic clutch is not necessary, and the power transmission is smoothly interrupted or shifted. This is advantageous in reducing the load fluctuation of the transmission belt.

  The transmission belt may be of any kind, such as a flat belt or a toothed belt (timing belt). In the case of a flat belt, either the inner surface (transmission surface) or the outer surface (back surface) may be brought into contact with the pulley body, but in the case of a toothed belt, the outer surface (back surface) is preferably brought into contact with the pulley body.

  As described above, according to the present invention, the pulley body is supported by the support means so as to be rotatable about the pulley shaft and swingable about the pivot shaft, and the pivot load is observed along the pulley shaft direction. When the transmission belt is moved in the pulley axis direction and the axial load is shifted with respect to the pivot axis, the pulley body is at least inclined when the pulley body is tilted to the front side in the rotation direction of the pulley body with respect to the direction. In a state where the pivot is stationary with respect to the pulley axis direction, the meandering of the transmission belt can be quickly and reliably eliminated.

  Since the pivot shaft can be reciprocated in the pulley axis direction, the transmission belt can be moved following the movement of the pivot shaft by the force acting on the transmission belt from the pulley body, and the transmission belt can be moved with a simple structure. The running position can be changed.

  In addition, according to the belt transmission device provided with the pulley for the transmission belt, the transmission belt can be prevented from meandering while giving a stable tension to the transmission belt, and the transmission capability of the transmission belt can be sufficiently exhibited. On the other hand, since the traveling position of the transmission belt can be changed, various belt transmission devices including, for example, a clutch mechanism, a transmission mechanism, and the like can be configured.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the belt transmission device shown in FIG. 1, 1 is a driving pulley (flat pulley), 2 is a driven pulley (flat pulley), and a transmission belt (flat belt) 3 is wound around both pulleys 1 and 2, A tension pulley 4 is pressed against the transmission belt 3 to apply tension to the transmission belt 3. As will be described later, this belt transmission device is a transmission device including a clutch mechanism.

  The driving pulley 1 is fitted into a driving shaft (not shown) and is integrally rotated with the driving shaft. The driving pulley 1 is a pulley having a width that is at least twice the width of the transmission belt 3, and as will be described later, the belt 3 is always wound even if the traveling position of the transmission belt 3 is changed. Keep the state.

  The driven pulley 2 includes two pulleys, a power transmission pulley 22 and a clutch pulley 23, which are coaxial with each other, and a gear 24 is attached to the power transmission pulley 22 so as to rotate together. The power transmission pulley 22 and the clutch pulley 23 are disposed so that a slight gap is formed between the two pulley surfaces, and the two pulley surfaces are substantially flush with each other. Then, in a state where the transmission belt 3 is wound around the power transmission pulley 22 as shown by phantom lines in FIG. 1, a power transmission state in which the power of the driving shaft is transmitted to the gear 24 by the transmission belt 3, In a state where the transmission belt 3 is wound around the clutch pulley 23 as shown by a solid line in FIG. 1, a power cutoff state in which the power of the driving shaft is not transmitted to the gear 24 is established.

  The tension pulley 4 is attached to the tip of the urging arm 16 and is pressed against the transmission belt 3 by the arm 16. As shown in FIGS. 1 to 3, the tension pulley 4 supports a pulley body 5 around which the transmission belt 3 is wound, and the pulley body 5 so as to be rotatable about the pulley axis C1 and swingable about the pivot axis C2. Support means 10.

  The support means 10 has a cylindrical shaft member 11 that supports the pulley body 5 by a bearing 12, a support rod 13, a pin 17 that constitutes a pivot C2, and a pin 17 that reciprocates in the pulley axis C1 direction. And a moving mechanism 6. In the present embodiment, the moving mechanism 6 employs a piston / cylinder mechanism including an air cylinder 71 and a piston 72 as will be described later, but is not limited thereto.

  The support rod 13 includes a mounting portion 13a fixed to the tip of the urging arm 16 with a nut, and a support portion 13b provided following one end of the mounting portion 13a.

  This support portion 13b has a portion corresponding to the diameter direction in a circular cross section cut into a D shape, and by this D cut, flat sliding surfaces 8c parallel to each other as shown in FIGS. , 8c are formed on the outer peripheral surface thereof. Further, arc surfaces on both sides connecting both side edges of the sliding surfaces 8c, 8c are formed by the outer peripheral surface of the support portion 13b.

  In addition, the support portion 13b includes an insertion hole 91 formed in the inside thereof so as to extend in the axial direction, and two long holes 92 that are opposed to each other in the radial direction and extend in the axial direction. In this support portion 13b, the end opposite to the attachment portion 13a (hereinafter, the end opposite to the attachment portion 13a is referred to as the tip of the support portion 13b, and the end on the attachment portion 13a side is the base end of the support portion 13b. The air cylinder 71 is attached, and the insertion hole 91 communicates with the inside of the air cylinder 71. A piston rod 73 of a piston 72 disposed in the air cylinder 71 is inserted into the insertion hole 91. Each of the long holes 92 is set to a length shorter than the pulley width of the pulley body 5.

  Of the two sliding surfaces 8c, 8c, on the sliding surface 8c located on the lower side in the state shown in FIG. 1, a pin-like regulating member 9 is spaced 2 in the direction of the pulley axis C1 with a predetermined interval. As will be described later, the pulley body 5 (shaft member 11) is allowed to swing around the pin 17, and the pulley body 5 (shaft member 11) is connected to the pulley shaft. The movement in the C1 direction is restricted.

  The shaft member 11 is extrapolated to the support portion 13b, and two sliding members 19 each having a D-shaped cross section are attached to the inner peripheral surface thereof so as to face each other in the diameter direction. . The sliding member 19 is formed on the inner surface of the shaft member 11 such that flat sliding surfaces 11a and 11a that are slidably in contact with the sliding surfaces 8c and 8c of the support portion 13b face each other. ing. Further, arcuate surfaces on both sides connecting both side edges of the sliding surfaces 11 a and 11 a are formed by the inner peripheral surface of the shaft member 11. Thus, in a state where the shaft member 11 is extrapolated to the support portion 13b, gaps 15 and 15 are formed between the arc surfaces on both sides of the support portion 13b and the arc surfaces on both sides of the shaft member 11. Is formed.

  Of the two sliding members 19, 19, the sliding member 19 positioned on the lower side in the state shown in FIG. 1 has arcuate ends on both ends as shown in FIG. 3. The arcuate end surface 33 is in contact with the regulating member 9 fitted into the support portion 13b.

  Further, the sliding member 19 and the shaft member 11 are formed with elongated holes 31 and 32 that open in a direction orthogonal to the sliding surfaces 11a and 11a, extending in the axial direction of the shaft member 11, and this In the state where the shaft member 11 is extrapolated to the support portion 13 b, the long holes 31 and 32 are integrated with the long hole 92 formed in the support portion 13 b, and between the support portion 13 b and the shaft member 11. A hole extending in the radial direction is formed. The sliding member 19 may be made of resin.

  The pin 17 is fitted into a hole formed in the piston rod 73 and penetrates the piston rod 73 in the radial direction, and both end portions thereof are elongated holes 92, 92 formed in the support portion 13b. The shaft member 11 and the sliding member 19 are disposed in elongated holes 31 and 32 formed therethrough. As shown in FIG. 2, the pin 17 is disposed at a predetermined tilt angle α on the front side in the rotational direction of the pulley body 5 with respect to the axial load direction L.

Thus, the gaps 15 and 15 between the arcuate surfaces on both sides of the support portion 13b and the arcuate surfaces on both sides of the shaft member 11 and the arcuate end surface 33 of the sliding member 19 in contact with the regulating member 9 The shaft member 11, together with the pulley body 5, can swing with respect to the support portion 13 b around the pivot C <b> 2 constituted by the pin 17. The pin 17 can reciprocate in the direction of the pulley axis C1 in the elongated holes 92, 31, 32, and the shaft member 11 and the pulley can be changed by changing the position of the pin 17 in the direction of the pulley axis C1. The swing center of the main body 5 is changed.

  The air cylinder 71 is partitioned into two chambers by a piston 72, and each chamber is provided with a connection port. By supplying or discharging air to or from each chamber in the piston 72 through each connection port, a pressure difference is provided between the two chambers, whereby the piston 72 moves forward in the air cylinder 71.

  A piston rod 73 is attached to the piston 72. As described above, the piston rod 73 is disposed in the insertion hole 91 of the support portion 13b with the pin 17 fitted therein. Then, by driving the piston / cylinder, as the piston rod 73 reciprocates in the insertion hole 91 in the direction of the pulley axis C1, the pin 17 moves in the elongated holes 92, 31, 32. It reciprocates in the axial direction, so that the pivot C2 reciprocates in the direction of the pulley axis C1 within the pulley width of the pulley body 5. The pin 17 has a power transmission position corresponding to the position of the power transmission pulley 22 of the driven pulley 2 (see the phantom line in FIG. 1) and a power cutoff corresponding to the position of the clutch pulley 23 by the elongated holes 92, 31, 32. The position is changed to two positions (see the solid line in FIG. 1).

  Next, the operation of the tension pulley 4 will be described with reference to FIGS. Here, for easy understanding, the operation of the tension pulley 4 will be described on the assumption that the pin 17 is positioned at the center in the width direction of the pulley body 5.

  As shown in FIG. 5, when the transmission belt 3 near the center of the width of the pulley body 5, that is, at the position of the pin 17, moves toward the one side from the center of the pulley body 5 as shown by the chain line, the axial load is reduced to the pin 17 It moves to the one side of the pulley main body 5 from this position, and comes to act on the shaft member 11. As a result, a rotational moment about the pin 17 acts on the shaft member 11, and the shaft member 11 rotates and displaces around the pin 17 together with the pulley body 5.

  That is, when the direction of the axial load is parallel to the pin 17 (when L0), as shown in FIG. 4, the support portion 13 b, the pin 17 and the shaft member 11, the transmission belt 3 moves from the position of the pin 17 to one side Even if it slips, the rotational moment around the pin 17 does not occur. On the other hand, when the direction of the axial load is L which is inclined by an angle α with respect to the direction of the pin 17, when the transmission belt 3 moves from the position of the pin 17 to one side thereof, the component force L1 causes the pin 17 to move. A surrounding rotational moment is generated, and the shaft member 11 is rotationally displaced. The angle α corresponds to the tilt angle α of the pin 17 with respect to the direction of the axial load L.

  In the case of FIG. 2, the pulley body 5 is rotated and displaced around the pin 17 on which the pulley body 5 is tilted by the axial load L, so that the pulley body 5 is connected to the transmission belt 3 as shown in FIG. 5 (plan view). As shown in FIG. 6 (viewed in the direction of the arrow VI in FIG. 2), the transmission belt 3 is in an oblique state so that the side shifted from the pin 17 is the front side in the belt traveling direction. The transmission belt 3 is inclined in the direction of the axial load L so that the side on which the transmission belt 3 is displaced is low and the opposite side is high. 2, 5, and 6, the state where the pulley body 5 is rotationally displaced is indicated by a chain line.

  Accordingly, the transmission belt 3 is subjected to a return force (a force for returning the offset) due to the pulley body 5 being in an oblique state and a return force due to the inclination of the pulley body 5. 3 runs at the position of the pin 17. That is, the meandering of the transmission belt 3 is prevented when the pin 17 is stationary with respect to the pulley axis C1 direction.

  If the pulley 4 is used as a tension pulley as in the above embodiment, a stable tension can be applied to the transmission belt 3, which is advantageous in sufficiently exhibiting the transmission capability of the transmission belt 3.

  The support portion 13b and the sliding surfaces 8c and 11a of the shaft member 11 are brought into contact with each other by an axial load, and an appropriate sliding resistance acts between the both sliding surfaces 8c and 11a. Therefore, when the transmission belt 3 is traveling in the vicinity of the position of the pin 17, the pulley main body 5 is prevented from being slightly swung by the traveling vibration of the transmission belt 3, and the position of the transmission belt 3 is shifted to the pin 17. When the pulley body 5 is deviated, the pulley body 5 reacts with a high sensitivity and is rotationally displaced, thereby preventing the pulley body 5 from causing hunting that swings from side to side.

  Thus, since the pulley 4 can drive the transmission belt 3 at the position of the pin 17, the running position of the belt 3 can be changed by changing the position of the pin 17 in the direction of the pulley axis C <b> 1. .

  That is, as shown by a solid line in FIG. 1, in the state where the pin 17 is positioned at the power shut-off position by driving the piston / cylinder, the transmission belt 3 travels at the position of the pin 17, so the belt 3 It is wound around the clutch pulley 23.

  In this state, when the pin 17 is moved to the distal end side (right side in FIG. 1) of the support rod 13 by driving the piston / cylinder, the transmission belt 3 is relative to the base end side of the support rod 13 with respect to the pin 17. Therefore, the shaft load L shifts from the position of the pivot C2 to one side in the width direction of the pulley body 5 and acts on the shaft member 11. As described above, the pulley body 5 is rotationally displaced about the pivot C2 by the axial load L, and a force directed from the pulley body 5 to the transmission belt 3 toward the distal end side (right side in FIG. 1) of the support rod 13 is applied. If the pin 17 is continuously moved toward the tip end side of the support rod 13, a force directed toward the tip end side of the support rod 13 continues to act on the transmission belt 3, and the transmission belt 3 is moved by the movement of the pin 17. It follows and moves to the front end side of the support rod 13. Then, as indicated by phantom lines in FIG. 1, when the pin 17 is located at the power transmission position, the transmission belt 3 is wound around the power transmission pulley 22 and the power to the gear 24 is increased. Transmission will begin.

  Conversely, the pin 17 is positioned at the power transmission position, and the pin 17 is moved to the base end side of the support rod 13 by driving the piston / cylinder from the state where the transmission belt 3 is wound around the power transmission pulley 22. When it is moved to the left side of FIG. 1, the transmission belt 3 is relatively displaced toward the tip end side of the support rod 13 with respect to the pin 17, and the axial load L is shifted from the position of the pivot C2 in the width direction of the pulley body 5. It shifts to one side and acts on the shaft member 11. As described above, the pulley main body 5 is rotationally displaced about the pivot C2 by the axial load L, and a force directed from the pulley main body 5 to the transmission belt 3 toward the base end side (left side in FIG. 1) of the support rod 13 acts. . Therefore, if the pin 17 is continuously moved toward the base end side of the support rod 13, a force toward the base end side of the support rod 13 continues to act on the transmission belt 3, and the transmission belt 3 Following the movement of 17, it moves to the proximal end side of the support rod 13. Then, as shown by the solid line in FIG. 1, the transmission belt 3 is wound around the clutch pulley 23 when the pin 17 is located at the power cut-off position, so that the power transmission to the gear 24 is performed. Will be blocked.

  As described above, the belt transmission device does not forcibly change the traveling position of the transmission belt 3 by, for example, applying the transmission belt 3 to a flange provided on the pulley body 5, but the return force acting on the transmission belt 3 from the pulley body 5. Therefore, the pulley main body 5 does not need a flange because the traveling position of the transmission belt 3 is changed. In other words, there is no decrease in belt life due to flange contact. The pulley body 5 may be provided with a flange.

  Here, the moving speed of the pin 17 in the direction of the pulley axis C1 is set to a speed that allows the transmission belt 3 to follow the movement of the pin 17, particularly when the traveling speed of the transmission belt 3 is low. is required. The moving speed of the transmission belt 3 is the belt traveling speed, belt length, span length, load, belt characteristics (癖), transmission layout, tilt angle α, rotational displacement of the pulley body 5, Since it depends on other factors, the moving speed of the pin 17 may be set as appropriate based on these factors.

  Further, the belt transmission device realizes intermittent transmission of power even without an electromagnetic clutch, and is advantageous in reducing the load fluctuation of the transmission belt by smoothly performing intermittent transmission or shifting of power transmission.

  Furthermore, the pulley 4 can change the travel position of the belt 3 only by reciprocating the pin 17. Since the axial load acts on the support rod 13 and the shaft member 11 and does not act on the pin 17, the power for reciprocating the pin 17 can be reduced. As a result, the size of the moving mechanism 6 can be reduced or the structure thereof can be simplified.

  A loose crown may be attached to the outer peripheral surface of the pulley body 5. If the crown is gentle, it is possible to avoid applying a large load to the transmission belt 3.

  In the belt transmission device, the driven pulley 2 is composed of a power transmission pulley 22 and a clutch pulley 23 and has a clutch mechanism. However, the invention is not limited thereto, and the driven pulley 2 is used for a high speed ratio. It is also possible to constitute a device having a speed change mechanism comprising a pulley and a low speed ratio pulley.

  Further, in the belt transmission device, the drive source for reciprocating the pin 17 is configured by the cylinder 71. However, the drive source is not limited to this, and various devices such as a motor, a linear motor, a solenoid, and a hydraulic cylinder are used. Is possible. In addition, the belt transmission device is configured such that the transmission belt 3 travels at two different travel positions. By configuring the drive source of the pin 17 with a stepping motor or the like, two or more transmission belts 3 are provided. It is also possible to travel at the travel position.

It is sectional drawing of a belt transmission apparatus. It is a longitudinal cross-sectional view of a pulley. It is the III-III sectional view of Drawing 2 which omitted some members. It is a figure explaining that a rotational moment generate | occur | produces in a shaft member by the shaft load in the use condition of the pulley. It is a top view which shows the use condition of the pulley. FIG. 6 is a view taken in the direction of arrow VI in FIG. 2.

Explanation of symbols

1 Driving pulley 2 Driven pulley 3 Transmission belt 4 Tension pulley (Pulley for transmission belt)
5 Pulley body 6 Moving mechanism 10 Support means 11 Shaft member 13 Support rod 17 Pin 22 Power transmission pulley 23 Clutch pulley 71 Air cylinder 72 Piston 73 Piston rod C1 Pulley shaft C2 Pivot axis α Tilt angle

Claims (5)

A pulley body around which a transmission belt is wound;
A support means for supporting the pulley body so as to be rotatable around a pulley axis and swingable around a predetermined pivot axis;
The pulley body has a width over two or more belt running positions aligned in the pulley axial direction,
The pivot is tilted at a predetermined tilt angle on the front side in the rotational direction of the pulley body with respect to the direction of the axial load as viewed along the pulley axis direction,
The support means is configured to be capable of reciprocating relative to the pulley main body in the pulley axial direction within the pulley width of the pulley main body, and the belt running on each of the belts. Transmission belt pulley configured to be positioned in position . The pulley according to claim 1, wherein
The pulley for a transmission belt, wherein the tilt angle of the pivot is set in an angle range exceeding 0 degrees and not exceeding 90 degrees. The pulley according to claim 1 or 2 ,
The support means is
A cylindrical shaft member provided integrally with the pulley body and rotatably supporting the pulley body around the pulley shaft;
A support rod inserted into the cylindrical shaft member and extending coaxially with the pulley shaft;
A pin that is reciprocally supported in the axial direction with respect to the support rod, and that supports the shaft member together with the pulley body so as to be swingable with respect to the support rod;
A transmission belt pulley including a power source that generates power for reciprocating the pin. A pulley for a transmission belt according to any one of claims 1 to 3 ,
A driving pulley,
A driven pulley,
A belt transmission device comprising: a pulley for a transmission belt, a transmission belt wound around a driving pulley and a driven pulley. The belt transmission device according to claim 4 ,
One of the driving side pulley and the driven side pulley is a belt transmission device having a plurality of pulleys arranged side by side in the rotation axis direction and having substantially the same outer peripheral surface.

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