Clutch for a belt drive system

Abstract

Systems, apparatuses, and methods for a tensioning system of a drive belt are disclosed. In particular, a tensioning system for a drive belt of a rotating screen of a combine harvester is disclosed. The tensioning system provides for avoiding over-tensioning of the drive belt when the drive belt disengages from a drive shaft. The tensioning system can also provide for maintaining continuous operation of the drive shaft as the drive belt moves between engagement and disengagement with the drive shaft.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to belt drive systems, and more particularly, to belt drive systems of combines. BACKGROUND

[0002] Combines use a rotatable screen as an initial filter to remove material from intake air used to provide cooling to an engine of the combine (and in some embodiments, other aspects of the combine). SUMMARY

[0003] A first aspect of the present disclosure relates to a tensioning device. The tensioning device includes a tensioner pivotable about a first axis. The tensioner can include a first arm rotatable about the first axis, a second arm rotatable about the first axis, and the first arm and the second arm pivotable relative to each other, a biasing assembly connecting the first arm and the second arm, the biasing assembly resiliently connecting the first arm and the second arm, and a first pulley disposed at an end of the second arm, the first pulley configured to engage a drive belt. The tensioning device can also include a third arm pivotable about the first axis, and an actuator connected to the tensioner and the third arm. The tensioner and the third arm are movable about the first axis between a first configuration in which the third arm is configured to disengage from the drive belt when the actuator is in a first position, and a second configuration in which the third arm is configured to engage the drive belt when the actuator is in a second position different from the first position.

[0004] A second aspect of the present disclosure relates to a system that can include a rotatable screen defining a circumferential surface, a drive belt engaged with a portion of the circumferential surface, a shaft including a first pulley selectively engageable with the drive belt, the rotatable screen rotatable in response to rotation of the shaft, the rotation of the shaft transmitted to the rotatable screen by the drive belt, and a tensioning device. The tensioning device can include a tensioner pivotable about a first axis, the tensioner including a second pulley engaging the drive belt to create a selected amount of tension in the drive belt, a clutch arm pivotable about the first axis, and an actuator connected to the tensioner and the clutch arm, the actuator movable between a first position in which the tensioner and the clutch arm are pivoted into a first configuration in which the clutch arm does not engage the drive belt, and a second position in which the tensioner and the clutch arm are pivoted into a second configuration in which the clutch arm engages the drive belt to disengage the drive belt from the first pulley.

[0005] Various aspects can include one or more of the following features. The first arm, the second arm, and the third arm can be mounted on a common shaft defining a first axis. The third arm can be disposed between the first arm and the second arm along the shaft. The biasing assembly can include a first flange engaged with the first arm; a biasing member; a rod pivotably connected to the second arm; and a second flange connected to the rod, the biasing member being captured between the first flange and the second flange. The biasing element can be a spring, and the rod can extend through the first flange and the second flange. Rotation of the second arm relative to the first arm in a first rotational direction can compress the spring. The actuator can include a handle pivotable about a second axis and a linkage connecting the handle to the first arm and the third arm. When the handle is rotated about the second axis from a first position to a second position, the first arm can rotate a first amount, and the third arm can rotate a second amount greater than the first amount. The linkage can include a first link extending from the handle to the first arm and a second link extending from the first link to the third arm. The first link can be connected to the first arm at a first end of the first arm; the second link can be connected to a first end of the third arm; and a length of the first end of the third arm can be less than a length of the first end of the first arm. The third arm can include at least one second wheel, and the at least one second wheel can be configured to engage the belt when the third arm is in the second configuration. Movement of the handle from the first position to the second position can cause the first rotational amount of the first arm and the second rotational amount of the third arm, the first rotational amount being less than the second rotational amount.

[0006] Various aspects can also include one or more of the following features. The tensioner can include a first arm and a second arm that are resiliently connected together. The second wheel can be connected to the second arm, and the elastic force exerted between the first arm and the second arm can be exerted through the second wheel to the drive belt to generate a selected amount of tension within the drive belt. A first amount of tension generated within the drive belt by the tensioner when the tensioner is in the first configuration can be the same as a second amount of tension generated within the drive belt by the tensioner when the tensioner is in the second configuration. The actuator can include a handle that pivots about a second axis and a linkage that connects the handle to the clutch arm and the first arm. The clutch arm can rotate a first amount and the first arm can rotate a second amount that is less than the first amount when the handle is rotated about the second axis from a first position to a second position. The linkage can include a first link that extends from the handle to the first arm and a second link that extends from the first link to the clutch arm. The at least one third wheel can include two third wheels that are offset from each other along a length of the clutch arm. Movement of the actuator from the first position to the second position can cause the second arm to rotate in a first rotational direction toward the shaft such that the first wheel passes a position between the two third wheels, causing the two third wheels to disengage the drive belt from the first wheel. The biasing assembly can connect the first arm and the second arm. The biasing assembly can include a first flange that engages the first arm, a biasing member, a rod that is pivotably connected to the second arm, and a second flange that is connected to the rod. The biasing member can be captured between the first flange and the second flange. The clutch arm can include at least one third wheel that engages the drive belt to disengage the drive belt from the first wheel when the actuator is moved from the first position to the second position. The biasing element can be a spring, and the rod can extend through the first flange and the second flange.

[0007] Other features and aspects will become apparent by consideration of the detailed description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0008] The detailed description is described with reference to the accompanying drawings.

[0009] Figure 1 is a side view of an example combine harvester according to some embodiments of the disclosure.

[0010] Figure 2 is a perspective view of a portion of a combine harvester according to some embodiments of the disclosure Figure 1 is a perspective view of a portion of a combine harvester showing outwardly rotating side panels and a rotating screen assembly.

[0011] Figure 3 is a side view of an example rotating screen assembly according to some embodiments of the disclosure with a tensioning system in a first configuration.

[0012] Figure 4is a perspective view of a tensioning system of a rotating screen assembly according to some embodiments of the present disclosure in a first configuration. Figure 1 is a detailed view of a tensioning system of a rotating screen assembly according to some embodiments of the present disclosure in a first configuration.

[0013] Figure 5 is a perspective view of a rotating screen assembly according to some embodiments of the present disclosure in a second configuration. Figure 1 is a side view of an exemplary rotating screen assembly according to some embodiments of the present disclosure.

[0014] Figure 6 is a detailed view of a tensioning system of a rotating screen assembly according to some embodiments of the present disclosure in a second configuration. Figure 1 is a detailed view of a tensioning system of a rotating screen assembly according to some embodiments of the present disclosure in a second configuration.

[0015] Figure 7 is a perspective view of an exemplary biasing assembly of a tensioning system according to some embodiments of the present disclosure. Figure 1 is a perspective view of an exemplary biasing assembly of a tensioning system according to some embodiments of the present disclosure.

[0016] Figure 8 is a cross-sectional view along an axis of an exemplary tensioning system according to some embodiments of the present disclosure. Figure 1 is a cross-sectional view along an axis of an exemplary tensioning system according to some embodiments of the present disclosure.

[0017] Figure 9 is another perspective view of a tensioning system according to some embodiments of the present disclosure in a second configuration showing a clutch engaged with a drive belt and a drive belt disengaged from a drive shaft. Figure 1 is another perspective view of a tensioning system according to some embodiments of the present disclosure in a second configuration showing a clutch engaged with a drive belt and a drive belt disengaged from a drive shaft. DETAILED DESCRIPTION

[0018] To facilitate an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the examples. It will, nevertheless, be understood that no limitation of the scope of the disclosure is intended. Alterations and further modifications of the described devices, instruments, methods, and any further applications of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully intended to cover all modifications, alterations, and further applications of the principles of the present disclosure, including those that are presently known or developed in the future.

[0019] The present disclosure relates to tensioning systems for air filtration systems of agricultural vehicles, such as combines, and in particular to tensioning systems for belt drive systems, such as rotating screen assemblies. More particularly, the present disclosure relates to systems, methods, and apparatus for selectively connecting and disconnecting a belt drive system from a drive source. Although the examples described herein are made in the context of a combine, the scope of the present disclosure is not limited thereto. Rather, the concepts described herein are applicable to other agricultural vehicles and equipment, as well as other vehicles and equipment outside the agricultural field.

[0020] Figure 1 is a perspective view of an example combine harvester 100. A belt conveyor header 102 is attached to the combine harvester 100. In other embodiments, the combine harvester 100 can use other types of headers. The combine harvester 100 includes an operator's cab 104, a grain tank 106 in which processed grain is stored, and an engine compartment 108. Side panels 110 that define the sides of the engine compartment 108 include a plurality of slots 112 to allow air to flow in to provide convective cooling for various components of the combine harvester 100, such as the engine radiator (heat exchanger), oil cooler, and air conditioning condenser.

[0021] The side panels 110 are pivotably connected, for example, about a horizontal axis 114 to provide access to other components within the engine compartment. In particular, the side panels 110 are rotated about the horizontal axis 114 to an open configuration to provide access to, for example, the belt drive system in the form of a rotating screen assembly 200 as shown. Figure 2 As shown, the side panels 110 and the rotating screen assembly 200 are rotated about the horizontal axis 114 to an open configuration to expose components within the engine compartment 108, such as an engine heat exchanger 202, an oil cooler 204, and an air conditioning condenser 206. In some embodiments, the side panels 110 and the rotating screen assembly 200 can be rotated about different axes.

[0022] Figure 3 and Figure 4 is an elevational view of the rotating screen assembly 200, which includes a rotating screen 302 that rotates about an axis 303. The rotating screen 302 is porous (defining a plurality of apertures) and operates to filter air drawn into the engine compartment 108. The rotating screen 302 rotates about the axis 303 in response to movement of an endless drive belt 304 that engages an outer circumferential surface 306 of the rotating screen 302. For example, as shown in Figure 9 The circumferential surface 306 can be disposed in a groove or track 307 on the rotating screen 302. The track 307 can include a sidewall 309 that captures the drive belt 304 and maintains alignment of the drive belt 304 on the rotating screen 302.

[0023] As shown in Figure 3 The drive belt 304 is wrapped around the circumferential surface 306, a first idler 308, a drive shaft 310, and a second idler 312 that forms part of a tensioning system 314. The first idler 308 and the second idler 312 are rotatable in response to movement of the drive belt 304. The tensioning system 314 is operable to selectively engage and disengage the drive belt 304 with the drive shaft 310.

[0024] The drive shaft 310 is connected to and driven by an engine of the combine harvester 100. As shown in Figure 3As shown, with the tensioning system 314 in the first configuration, the drive belt 304 engages the drive shaft 310 and, in particular, the wheel 316 attached to or formed on the drive shaft 310 and rotatable therewith. The drive shaft 310 causes movement of the drive belt 304, which in turn causes the rotating screen 302 to rotate about the axis 303. In the second configuration, as shown Figure 5 and Figure 6 the tensioning system 314 has disengaged the drive belt 304 from the wheel 316 of the drive shaft 310, thereby preventing the rotating screen 302 from being rotated by the drive shaft 310. Further, as described in greater detail below, the tensioning system 314 is movable between the first and second configurations while the drive shaft 310 continues to be rotated by the engine. As a result, the user is able to avoid deactivating the engine of the combine 100 in order to engage or disengage the rotating screen 302.

[0025] In order to reposition the rotating screen assembly 200 to provide access to the interior of the engine compartment 108, it can be desirable to disengage the rotating screen 302 from the drive shaft 310. For example, access to the interior of the engine compartment 108 can be desirable in order to clean the interior and components contained therein. Maintaining operation of the engine while the rotating screen 302 is disengaged allows continued operation of other systems of the combine 100. For example, operation of the compressed air system of the combine 100 can continue and be used to clear dust and other debris from the engine compartment. Such clearing can improve cooling of the engine and other systems of the combine 100, which can be diminished over time as a result of operation of the combine 100.

[0026] More particularly, the operator can exit the operator compartment 104 with the engine of the combine 100 running, open the side panel 110, disengage the drive belt 304 from the wheel 316 of the drive shaft 310 with the tensioning system 314, and continue cleaning the rotating screen 302 and other components within the engine compartment 108 using the compressed air system, the operation of which is maintained as a result of the continued operation of the engine. As a result, the operator avoids having to shut down the engine, exit the operator compartment, open the side panel, disengage the drive belt from the drive shaft, lift the rotating screen assembly 200, return to the operator compartment, restart the engine, exit the cab again, and return to the engine compartment to perform the cleaning using the compressed air system. As a result, the time required to perform the cleaning of the rotating screen 302 or the engine compartment 108, or both, can be reduced.

[0027] Further, in some embodiments, due to the tensioning system 314, the amount of tension applied to the drive belt 304 when the drive belt 304 is engaged with the drive shaft 310 (e.g., with the pulley 316 of the drive shaft 310) is the same or approximately the same as the tension imparted to the drive belt 304 when the tensioning system 314 has disengaged the drive belt 304 from the drive shaft 210.

[0028] In some embodiments, the tension imparted to the drive belt 304 by the tensioning system 314 in the second configuration is less than the tension imparted to the drive belt 304 by the tensioning system 314 in the first configuration. Also, the tension applied to the drive belt 304 when the tensioning system 314 is in the second configuration is sufficient to maintain engagement of the drive belt with the clutch of the tensioning system 314, which will be described in more detail below. As a result, the risk of disengagement of the drive belt from the tensioning system 314 is reduced or eliminated, which provides for reliable engagement and disengagement of the drive belt 304 with the drive shaft 310. As a result, the tensioning system 314 provides for avoidance of intervention from an operator or other personnel for manually aligning or otherwise reengaging the drive belt with the drive shaft 310, idler pulleys 308 or 312, or any other portion of the belt drive system when reengagement of the drive belt 304 and drive shaft 310 is desired.

[0029] In some embodiments, the static tension applied to the drive belt 304 by the tensioning system 314 with the tensioning system 314 in the first configuration can be 82.6 Newtons (N), and in the second configuration, the tensioning system 314 can impart a static tension of 55.4 N in the drive belt 304. Thus, in some embodiments, the static tension imparted in the drive belt 304 by the tensioning system 314 can be 33% less in the second configuration than in the first configuration. In other embodiments, the amount of reduction in static tension in the drive belt 304 between the first and second configurations can be greater than or less than 33%. In other embodiments, the amount of static tension imparted to the drive belt 304 by the tensioning system 314 can be the same in both the first and second configurations. The values discussed are provided by way of example only and are not intended to limit the scope of the present disclosure. Other embodiments within the scope of the present disclosure can produce different amounts of tension in the drive belt. Thus, other tension values in the drive belt and other percentage changes in tension between the first and second configurations are within the scope of the present disclosure.

[0030] As discussed in greater detail below, maintaining the tension level at a constant or approximately constant level (e.g., the tension level maintained in the second configuration is less than the tension level maintained in the first configuration) can be attributed to the tensioner of the tensioning system 314 being pivotable, thereby allowing the tensioner to maintain a selected tension within the drive belt 304 as the drive belt 304 is repositioned to decouple the drive belt 304 from the drive shaft 310. By preventing an increase in the tension of the drive belt 304 as the drive belt 304 is decoupled from the drive shaft 310, damage to the drive belt 304 due to over-tensioning is avoided, and thus the life of the drive belt 304 is not reduced.

[0031] Referring to Figure 4 , the tensioning system 314 is positioned in a first or engaged configuration in which the drive belt 304 is engaged with the drive shaft 310. As explained previously, in the first configuration, the rotating screen 302 is rotated in response to rotation of the drive shaft 310 by motion transmitted by the drive belt 304. The tensioning system 314 includes a tensioner 400 that is connected to a shaft 402 and is pivotable thereon about an axis 404 defined by the shaft 402. The tensioner 400 includes a first portion 406 and a second portion 408. The first portion 406 and the second portion 408 are rotatable relative to one another about the axis 404. In the example shown, the first portion 406 is in the form of an arm that defines a hole 410 through which the shaft 402 extends. The second portion 408 is also in the form of an arm that has a hole 412 through which the shaft 402 extends.

[0032] The tensioner 400 also includes a biasing assembly 414 that elastically connects the first portion 406 to the second portion 408. The biasing assembly 414 allows limited rotation of the first portion 406 and the second portion 408 relative to each other. The biasing assembly 414 includes a rod 416 and a biasing component, such as a spring 418. In some embodiments, the spring 418 can be in the form of a coil spring. The spring 418 is held on the rod 416 and is captured between a first flange 420 that is engaged with the first portion 406 and a second flange 422 that is fastened to the rod 416. The first flange 420 and the second flange 422 include openings through which the rod 416 extends. In some embodiments, the first flange 420 is received onto the rod 416 but is movable along the rod 416, and the second flange 422 is fastened to the rod 416 at a fixed location. The fixed location of the second flange 422 can be selectively changed to adjust the amount of compression applied to the spring 418 by the first flange 420 and the second flange 422. Thus, the position of the second flange 422 along the rod 416 can be adjusted to change the amount of compression of the spring 418. The compression of the spring 418 imparts a force between the first portion 406 and the second portion 408 that biases the second portion 408 in the direction of rotation of the arrow 424. This force imparted by the spring 418 to the second arm 408 exerts tension in the drive belt 304 through the idler 312. Further, the compression force imparted to the spring 418 can be selected to produce a selected amount of tension in the drive belt 304.

[0033] Figure 7 A detailed perspective view of the tensioning system 314 that is part of the tensioner 400 is shown in FIG. 7. The first portion 406 includes a retainer flange 700. The retainer flange 700 includes an opening 702, which can be in the form of a slot. The rod 416 extends through the opening 702. A cylindrical bearing 704 is received onto the rod 416 and is slidable thereon. The cylindrical bearing 704 includes an elongated sleeve portion 706, an enlarged portion 708 adjacent the sleeve portion 706, a spherical bearing portion 710, and a hole 712 extending longitudinally therethrough. In some embodiments, the sleeve portion 706 can be a separate component from the cylindrical bearing 704. Thus, in some embodiments, the cylindrical bearing 704 can include the enlarged portion 708 and the spherical bearing portion 710, and the sleeve portion 706 can be a separate component positioned along the rod 416 adjacent the cylindrical bearing 704. The rod 416 extends through the hole 712. As shown in FIG. 7, the first flange 420 is received onto the rod 416 and is slidable thereon. The second flange 422 is fastened to the rod 416 at a fixed location. The fixed location of the second flange 422 can be selectively changed to adjust the amount of compression applied to the spring 418 by the first flange 420 and the second flange 422. Thus, the position of the second flange 422 along the rod 416 can be adjusted to change the amount of compression of the spring 418. The compression of the spring 418 imparts a force between the first portion 406 and the second portion 408 that biases the second portion 408 in the direction of rotation of the arrow 424. This force imparted by the spring 418 to the second arm 408 exerts tension in the drive belt 304 through the idler 312. Further, the compression force imparted to the spring 418 can be selected to produce a selected amount of tension in the drive belt 304. Figure 4A shoulder 714 is shown defined at the interface of the sleeve portion 706 and the enlarged portion 708. The first flange 420 is received on the sleeve portion 706 and abuts against the shoulder 714. The spherical bearing portion 710 is received in a recess 716 formed into the retainer flange 700. The recess 716 can have a spherical shape corresponding to the shape of the spherical bearing portion 710. An opening 702 extends through the recess 716. The engagement between the spherical portion 710 and the recess 716 allows the lever 416 to pivot relative to the retainer flange 700, and more generally relative to the first portion 406 of the tensioner 400.

[0034] In the example shown, the end 718 of the lever 416 is threaded and the position of the second flange 422 along the lever 416 is fixed by adjusting the position of a first threaded nut 720 against which the second flange 422 abuts. The threaded end 718 and the first threaded nut 720 have mating threads. By rotating the first nut 720 in a first rotational direction or a second rotational direction opposite the first rotational direction, the first nut 720 moves along the length of the lever 416 in one of the first or second longitudinal directions. As a result, the position of the second flange 422 can be changed. A second threaded nut 722 can also be included. The second nut 722 can be engaged with the first nut 720 to fix the position of the first nut 720, and thus the position of the second flange 422. Thus, the first nut 720 and the second nut 722 cooperate to resist inadvertent rotation of the first nut 720 along the lever 416 and inadvertent movement of the second flange 422 along the lever 416. As explained previously, adjusting the relative position of the first flange 420 and the second flange 422 changes the amount of compression of the spring 418, and thus the force applied to the drive belt 304. The spring 418, being compressed, urges the second portion 408 and the first portion 406 of the tensioner 400 toward each other, thereby applying a torque to the second portion 408 that urges the second portion 408 in the direction of arrow 726.

[0035] The lever 416 is pivotably connected to the second portion 408. In the example shown, the lever 416 includes a clevis 730 that receives a protrusion 732 formed on the second portion 408. A fastener 734 extends through the clevis 730 and the protrusion 732 to pivotably connect the lever 416 to the second portion 408.

[0036] Referring again to Figure 4The tensioning system 314 also includes a clutch 426. The clutch 426 is in the form of an arm that is pivotably received onto the shaft 402 and is positioned laterally between the first portion 406 and the second portion 408 of the tensioner 400 on the shaft 402. The clutch 426 includes a first arm portion 428 and a second arm portion 430. A hole 432 positioned between the first arm portion 428 and the second arm portion 430 extends through the clutch 426. The shaft 402 extends through the hole 432. Figure 8 is a cross-sectional view showing the position arrangement of the first portion 406 and the second portion 408 of the tensioner 400 and the clutch 426 along the shaft 402.

[0037] As shown in Figure 9 , the clutch 426 also includes a pair of rotatable idlers 434. The idlers 434 are configured to engage the drive belt 304 when the tensioning system 314 is moved from the first configuration to the second configuration to remove the drive belt 304 from the drive shaft 310 and, in particular, from the pulley 316 on the drive shaft 310. In other embodiments, the idlers 434 can be omitted and a protrusion can be formed on or included on the second arm portion 430 to engage the drive belt 304 and remove the drive belt 304 from the drive shaft 310 when the tensioning system 314 is moved from the first configuration to the second configuration. The idler 308, the idler 312, the track 307, the idlers 434, and the pulley 316 are aligned such that the drive belt 304 (or a centerline of the belt 304) is located in a plane.

[0038] Referring to Figures 3 to 6 , the tensioning system 314 also includes a handle 318 that is pivotably connected to a shaft 320 that defines an axis 322. A linkage 324 connects the handle 318 to the tensioner 400 and the clutch 426. In particular, the linkage 324 connects the first portion 406 of the tensioner 400 and the first arm portion 428 of the clutch 426 to the handle 318.

[0039] The linkage 324 includes a first link 326 (which can be in the form of a rod) that is connected to an end 328 of the handle 318 and an end 330 of the first portion 406 of the tensioner 400. A second link 332 extends from the first link 326 to the first arm 428 of the clutch 426. The first link 326 is pivotably connected to the handle 318 and the first portion 406 of the tensioner 400. For example, a clevis can be provided on the end of the first link 326 to connect to the handle 318 and the first portion 406. The second link 332 is pivotably connected to the first link 326 along its length and to the first arm 428 of the clutch 426. In some embodiments, the second link 332 can include clevises at opposite ends to form the pivotable connections to the first arm 428 and the first link 326. The handle 318 and the linkage 324 define an actuator for moving the tensioning system 314 from the first configuration to the second configuration.

[0040] The handle 318 is pivotable about an axis 322 defined by the shaft 320. In particular, in a first position shown in Figure 3 , the handle 318 is pivotable about the axis 322 in a first direction indicated by arrow 321 to place the handle 318 into a second position, which is shown in Figure 5 . Pivoting the handle 318 in the direction of arrow 321 from the first position causes the first link 326 to move in the direction of arrow 323. The movement of the first link 326 in the direction of arrow 323 causes the tensioner 400 and the clutch 426 to pivot about the axis 404 in the direction of arrow 325, which causes the drive belt 304 to disengage from the pulley 316. In the second position (shown in Figure 5 ), the handle 318 is returned to the first position by rotating the handle 318 about the axis 322 in the direction of arrow 327 (opposite the direction of arrow 321). As a result, the first link 326 moves in the direction of arrow 329, causing the tensioner 400 and the clutch 426 to pivot about the axis 404 in the direction of arrow 331. As a result, the handle 318 is returned to the first position and the tensioning system 314 is returned to the first configuration.

[0041] As shown in Figure 4 , for example, the length of the first arm portion 428 of the clutch 426 measured perpendicularly from the axis 404 of the shaft 402 is less than the length of the first portion 406 of the tensioner 400 also measured perpendicularly from the axis 404 of the shaft 402. Due to this difference in lengths, the amount that the first portion 406 of the tensioner 400 rotates about the axis 404 is less than the amount that the clutch 426 rotates.

[0042] In operation, when the handle 318 is moved from the first position shown in Figure 3 to the second position shown in Figure 5In the second position shown, the tensioning system 314 moves from a first configuration in which the drive belt 304 is engaged with the pulley 316 to a second configuration in which the drive belt 304 is disengaged from the pulley 316. During this movement, the clutch 426 rotates about the axis 404 such that the idler pulley 434 engages the drive belt 304 and removes the drive belt 304 from the pulley 316. This relative movement of the clutch 426 and the pulley 316 causes the pulley 316 to pass through positions between multiple idler pulleys 434. The tensioner 400 also rotates about the axis 404. Figure 9 As shown, when the tensioning system 314 is in the second configuration, the drive belt 304 is completely separated from the pulley 316.

[0043] In the example shown, the rotational amount of tensioner 400 is less than the rotational amount of clutch 426. Because tensioner 400 is allowed to rotate about axis 404 on shaft 402, the amount of force applied to drive belt 304 by biasing assembly 414 (applied via idler pulley 312) can be less than the force applied when tensioning system 314 is in the first configuration. Therefore, in the second configuration, tensioner 400 reduces the tension in drive belt 304 compared to the tension level maintained in drive belt 304 when tensioning system 314 is in the first configuration. In some embodiments, the tension level applied to drive belt 304 by tensioner 400 in the second configuration is equal to or less than the tension level applied to drive belt 304 by tensioning system 400 in the first configuration. As a result, over-tensioning of drive belt 304 is avoided, thereby extending the service life of drive belt 304.

[0044] Handle 318 around axis 322 from Figure 5 The second position shown in the diagram rotates to Figure 3 The first position shown causes the tensioning system to return from the second configuration to the first configuration. When the handle 318 is moved to the first position, the coupling device 324 causes the tensioner 400 and the clutch 426 to pivot about the axis 402. As the clutch 426 pivots, the drive belt 304 re-engages with the pulley 316, and the idler pulley 434 disengages from the drive belt 304. Furthermore, because the idler pulleys 308, 312, 316, and 434 are aligned to hold the drive belt 304 in a plane, and tension is maintained on the drive belt 304 when disengaged from the pulley 316, the drive shaft 310 can remain in a rotating state when the tensioning system 314 moves between the first and second configurations.

[0045] In some embodiments, one or more of idler pulleys 308, 312, 316, and 434 may define a groove, such as in a V-shape, and the drive belt 304 may include a cross-sectional shape conforming to the groove, such as a V-shape. In some embodiments, the track 307 may also define a profile conforming to the cross-sectional shape of the drive belt 304, such as a V-shape.

[0046] Without in any way limiting the scope, interpretation, or application of the claims accompanying this disclosure, a technical effect of one or more of the example embodiments disclosed herein is to provide a tensioning system operable to maintain tension on a drive belt at a desired tension level that does not over-tension the drive belt when the drive belt is disengaged from a power source, such as a drive shaft. Maintaining the desired tension level while the drive belt is disengaged from the drive shaft avoids damage to the drive belt and extends the useful life of the drive belt. Another technical effect of one or more of the example embodiments disclosed herein is to conserve resources, such as time and fuel, by maintaining the continued operation of an engine of a vehicle while the drive belt is engaged and disengaged.

[0047] While example embodiments of the present disclosure are described above, these descriptions should not be viewed in a restrictive or limiting sense. Instead, other changes and modifications can be made to the example embodiments without departing from the scope and spirit of the present disclosure as defined in the claims that follow.

Claims

1. A tensioner comprising: a tensioner (400) pivotable about a first axis, the tensioner comprising: a first arm (406) rotatable about the first axis (404); a second arm (408) rotatable about the first axis, the first and second arms pivotable relative to one another; a biasing assembly (414) connecting the first and second arms, the biasing assembly resiliently connecting the first and second arms; and a first wheel (312) disposed at an end of the second arm, the first wheel configured to engage a drive belt (304); a third arm (426) pivotable about the first axis; and an actuator connected to the tensioner and the third arm, the tensioner and the third arm movable about the first axis between a first configuration in which the third arm is configured to disengage the drive belt when the actuator is in a first position and a second configuration in which the third arm is configured to engage the drive belt when the actuator is in a second position different from the first position.

2. The tensioning device of claim 1, wherein, the first arm (406), the second arm (408), and the third arm (426) are mounted on a common shaft (402) defining the first axis (404).

3. The tensioning device of claim 2, wherein, the third arm (426) is disposed between the first arm (406) and the second arm (408) along the common shaft (402).

4. The tensioning device of any one of claims 1 to 3, wherein, the biasing assembly (414) comprises: a first flange (420) engaged with the first arm (406); a biasing member; a rod (416) pivotably connected to the second arm (408); and a second flange (422) connected to the rod, the biasing member being captured between the first and second flanges.

5. The tensioning device of claim 4, wherein, the biasing member is a spring (418), and wherein the rod (416) extends through the first flange (420) and the second flange (422).

6. The tensioning device of claim 5, wherein, rotation of the second arm (408) relative to the first arm (406) in a first rotational direction compresses the spring (418).

7. The tensioning device of any one of claims 1 to 3, wherein, the actuator comprises: a handle (318) pivotable about a second axis (322); and a linkage (324) connecting the handle to the first arm (406) and the third arm (426), the first arm rotating a first amount and the third arm rotating a second amount greater than the first amount when the handle is rotated about the second axis from the first position to the second position.

8. The tensioning device of claim 7, wherein, the linkage (324) comprises: a first link (326) extending from the handle (318) to the first arm (406); and a second link (332) extending from the first link to the third arm (426).

9. The tensioning device of claim 8, wherein, The first link (326) is connected to the first arm (406) at a first end of the first arm, wherein the second link (332) is connected to a first end of the third arm (426), and wherein a length of the first end of the third arm is less than a length of the first end of the first arm.

10. The tensioning device of any one of claims 1 to 3, wherein, The third arm (426) includes at least one second pulley (434), and wherein the at least one second pulley is configured to engage the drive belt (304) when the third arm is in the second configuration.

11. The tensioning device of claim 7, wherein, Movement of the handle (318) from the first position to the second position results in a first amount of rotation of the first arm (406) and a second amount of rotation of the third arm (426), the first amount of rotation being less than the second amount of rotation.

12. A belt drive system, comprising: the tensioner of claim 1 ; a rotatable screen (302) defining a circumferential surface (306); a drive belt (304) engaged with a portion of the circumferential surface; and a shaft (310) including a second pulley (316) that is selectively engageable with the drive belt, the rotatable screen being rotatable in response to rotation of the shaft, the rotation of the shaft being transmitted to the rotatable screen through the drive belt, the first pulley (312) of the tensioner being engaged with the drive belt to generate a selected amount of tension in the drive belt, and the drive belt being disengaged from the first pulley when the third arm (426) is in the second configuration.

13. The belt drive system of claim 12, wherein, The first pulley (312) is connected to the second arm (408), and wherein a spring force exerted by the biasing assembly (414) between the first arm (406) and the second arm is exerted through the first pulley (312) to the drive belt (304) to generate a selected amount of tension within the drive belt.

14. The belt drive system of any one of claims 12-13, wherein, A first amount of tension generated within the drive belt (304) by the tensioner (400) when the tensioner is in the first configuration is equal to or greater than a second amount of tension generated within the drive belt by the tensioner when the tensioner is in the second configuration.

15. The belt drive system of any one of claims 12-13, wherein, The actuator includes: a handle (318) that is pivotable about a second axis (322); and a linkage (324) connecting the handle to the third arm (426) and the first arm (406), the third arm rotating a first amount and the first arm rotating a second amount that is less than the first amount when the handle is rotated about the second axis from the first position to the second position.

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