Torque limiting mechanism of solar tracking system
By using friction rings as torque limiters in the solar tracking system, the system's damage problem under the influence of external torque is solved, faster stops and lower gear contact speeds are achieved, and system stability and safety are improved.
Patent Information
- Application Number
- CN202380042543.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-05-24
- Filing Date
- 2023-05-25
- Publication Date
- 2025-01-17
AI Technical Summary
When existing solar tracking systems are affected by external torques such as wind, uneven snow, seismic activities, etc., it is easy to cause damage to the tracker drive components. The existing clutch systems have a large number of moving parts and a large difference between static sliding torque and dynamic sliding torque. The value causes insufficient friction and cannot effectively limit the rotation speed.
Using a friction ring as a torque limiter, it is placed between the gears or worms in the tracker driving assembly. When the torque exceeds the threshold, the component is allowed to slide relative to each other, thereby reducing the difference between the static sliding torque and the dynamic sliding torque, preventing the gear from further. Rotate to reduce damage to the tracker drive assembly components.
Effectively reduces damage to the tracker drive components, improves the stability and safety of the system. By reducing the difference between static sliding torque and dynamic sliding torque, the sliding can be stopped faster, reducing the gear contact speed and reducing the Risk of damage to the tracker driver components.
Smart Images
Figure CN119325537A_ABST
Abstract
Description
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This application claims priority under 35 U.S.C. 119 to U.S. Provisional Application No. 63 / 365,318, filed on May 25, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field
[0003] The present disclosure relates to torque limiting mechanisms that may be implemented in a solar tracking system. Background Art
[0004] Solar farms, photovoltaic (PV) power plants, and other solar energy systems in which a large number of photovoltaic modules collect sunlight and generate energy are becoming increasingly common. In some of these systems, multiple PV modules can be coupled to a PV module mounting structure, which is mounted on one or more support structures or piles. A mounting interface can be used to secure the PV module mounting structure to the support structure. In a solar tracking system (or a system in which the PV modules are capable of tracking the position of the sun throughout the day), the PV module mounting structure is coupled to the mounting interface in a manner that allows the PV module mounting structure to rotate relative to the support structure. A tracker drive assembly (including a drive motor and one or more gears) can be used to selectively rotate the PV module mounting structure and the PV modules coupled thereto. Changing the angle of the PV modules relative to the support structure enables the PV modules to track the position of the sun and maximize efficiency.
[0005] While rotating the PV module mounting structure to change the angle of the PV modules enables the PV modules to track the position of the sun and improves the efficiency of the system, this rotational freedom can also have undesirable effects. For example, wind, uneven snow cover, seismic activity, and other events can cause torque to be applied to the tracker drive assembly. If the torque is large enough, the tracker drive assembly may be damaged or broken. For example, if a gust of wind hits a row of PV modules coupled to the PV module mounting structure, the rotational torque generated by the wind may be transmitted to components of the tracker drive assembly (e.g., gears) and damage them.
[0006] Existing clutch systems have a large number of moving parts and typically include a large difference between static slip torque and dynamic slip torque. This causes a slipping clutch in an existing system to stop with greater force and / or potentially accelerate faster because there is reduced friction to reduce the rotational speed of the tracker drive assembly components. Therefore, there is a need for an improved torque limiter that reduces the rotational torque on the tracker drive assembly and does not require a large number of moving parts.
[0007] The claimed subject matter of the present disclosure is not limited to implementations that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is merely intended to illustrate one example technology area where some implementations described in this disclosure may be practiced. Summary of the invention
[0008] This summary is intended to introduce a series of concepts in a simplified form, which will be further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0009] Exemplary embodiments of the present disclosure address problems encountered in conventional solar tracking systems, including problems associated with damage to tracker drive assemblies caused by torque generated by wind, uneven snow accumulation, seismic activity, and other events. The embodiments disclosed herein address this problem by providing a torque limiter that is easy to manufacture, operate, and install. In addition, the torque limiter of the present disclosure can reduce the difference between static slip torque and dynamic slip torque, thereby stopping slipping more quickly than a clutch mechanism with a larger difference between static and dynamic slip torques. In addition, reducing the difference between static slip torque and dynamic slip torque can reduce the speed at which a first component in a gear moves and ultimately contacts a second component of the gear to prevent further rotation of the gear, which can reduce damage to components of the tracker drive assembly.
[0010] The torque limiter of the present disclosure includes a friction ring that can be placed between the moving parts of one or more gears in a tracker drive assembly. When the amount of torque between these moving parts exceeds a threshold, the torque limiter can slide, allowing the parts to move relative to each other. For example, in one embodiment, the torque limiter can be placed between the inner surface of a pinion in a spur gear and the outer surface of an input shaft. When the amount of torque exceeds a threshold, the pinion can rotate while the input shaft remains stationary. In another embodiment, the torque limiter can be placed between the inner surface of a worm wheel in a worm gear and the outer surface of an output shaft. When the amount of torque exceeds a threshold, the output shaft can rotate while the worm wheel remains stationary.
[0011] For example, in one embodiment, a torque limiting mechanism in a solar tracking system may include: a drive motor configured to rotate a drive shaft; at least one gear configured to convert the rotation of the drive shaft into a rotation of a photovoltaic (PV) module mounting structure; and a torque limiter disposed between an inner surface of a first component of the at least one gear and an outer surface of a second component of the at least one gear. The torque limiter may be a friction ring configured to allow the first component to slide relative to the second component when the amount of torque between the first component and the second component exceeds a threshold.
[0012] In some embodiments, the friction ring may include a plurality of pointed teeth protruding from a surface of the friction ring.
[0013] In some embodiments, the torque limiting mechanism may further include an intermediate ring disposed between the friction ring and at least one of the inner surface of the first component and the outer surface of the second component.
[0014] In some embodiments, the PV module mounting structure may be a torque tube.
[0015] In some embodiments, at least one gear can be a parallel axis gear. In these embodiments, the parallel axis gear can include a spur gear including a toothed wheel, a pinion, an input shaft, and an output shaft, and a friction ring can be placed between an inner surface of the pinion and an outer surface of the input shaft. The spur gear can also include a spacer having an inner surface and an outer surface, and the inner surface can be coupled to the input shaft, and the friction ring can be placed between the outer surface of the spacer and the inner surface of the pinion. The input shaft can be a drive shaft and the output shaft can be a PV module mounting structure.
[0016] In some embodiments, at least one gear may be an intersecting axis gear. In these embodiments, the intersecting axis gear may include a worm gear including a worm wheel, a worm, an input shaft, and an output shaft, and a friction ring is placed between the inner surface of the worm wheel and the outer surface of the output shaft. The torque limiting mechanism may also include a parallel axis gear with a pinion, wherein the input shaft is a drive shaft and the output shaft rotates the pinion of the parallel axis gear. The output shaft may include a connector that connects the first PV module mounting structure segment to the second PV module mounting structure segment, and the friction ring may be placed between the inner surface of the worm wheel and the outer surface of the connector. The connector may include a first connector component connected to the first PV module mounting structure segment and a second connector component connected to the second PV module mounting structure segment to achieve independent torque limiting of the first PV module mounting structure segment and the second PV module mounting structure segment. The friction ring may include a first ring placed between the inner surface of the worm wheel and the outer surface of the first connector component and a second ring placed between the inner surface of the worm wheel and the outer surface of the second connector component.
[0017] In another embodiment, a torque limiting mechanism in a solar tracking system may include a drive motor configured to rotate a drive shaft, and a worm gear including a worm wheel, a worm, an input shaft, and an output shaft. The output shaft may include a first photovoltaic (PV) module mounting structural segment, a second PV module mounting structural segment, and a connector that connects the first PV module mounting structural segment to the second PV module mounting structural segment. The worm gear may be configured to convert the rotation of the drive shaft into the rotation of the output shaft. The torque limiting mechanism may also include a torque limiter disposed between the inner surface of the worm wheel and the outer surface of the connector, configured to allow the worm wheel to slide relative to the connector when the amount of torque between the inner surface of the worm wheel and the outer surface of the connector exceeds a threshold.
[0018] In some embodiments, the connector may include a first connector component coupled to the first PV module mounting structure segment and a second connector component coupled to the second PV module mounting structure segment to achieve independent torque limiting of the first PV module mounting structure segment and the second PV module mounting structure segment. In these embodiments, the torque limiter may include a first friction ring disposed between an inner surface of the worm gear and an outer surface of the first connector component, and a second friction ring disposed between an inner surface of the worm gear and an outer surface of the second connector component.
[0019] In another embodiment, a torque limiting mechanism in a solar tracking system includes: a drive motor configured to rotate a drive shaft; a spur gear including a toothed wheel, a pinion, an input shaft, and an output shaft, wherein the spur gear is configured to convert the rotation of the drive shaft into the rotation of the output shaft; and a torque limiter disposed between an inner surface of the pinion and an outer surface of the input shaft, configured to allow the inner surface of the pinion to slide relative to the outer surface of the input shaft when the amount of torque between the pinion and the input shaft exceeds a threshold.
[0020] In some embodiments, the input shaft may be a drive shaft.
[0021] In some embodiments, the torque limiter can be a friction ring. In these embodiments, the spur gear can also include a spacer having an inner surface and an outer surface, and
[0022] The inner surface may be coupled to the input shaft, with the friction ring interposed between the outer surface of the spacer and the inner surface of the pinion.
[0023] The objects and advantages of the embodiments will be realized and obtained at least by the elements, features and combinations thereof particularly pointed out in the claims.The foregoing summary and the following detailed description are exemplary and illustrative and are not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Example embodiments will be described and illustrated in greater detail with reference to the accompanying drawings, in which:
[0025] Figure 1 An exemplary sun tracking system is shown;
[0026] Figure 2A-2E Various views and components of spur gears including an exemplary torque limiter are shown;
[0027] Figure 3A-3C Various views and components of a worm gear including an exemplary torque limiter are shown;
[0028] Figure 4 Shown with Figure 3A-3C Another exemplary torque limiter used with the worm gear shown in;
[0029] Figure 5A-5D illustrates various views and components of an exemplary sun tracking system including another exemplary torque limiter; and
[0030] Figure 6 shows a structured Figure 5A Another exemplary worm gear and torque limiter in a sun tracking system is shown. DETAILED DESCRIPTION
[0031] The embodiments of the present disclosure will be explained with reference to the accompanying drawings. It should be understood that these drawings are diagrammatic and schematic representations of such example embodiments and are not restrictive and are not necessarily drawn to scale. In the accompanying drawings, unless otherwise specified, features with the same number represent the same structure and function.
[0032] Figure 1 An exemplary solar tracking system 100 is shown. System 100 includes a plurality of PV modules 102, a PV module mounting structure 104, a tracker drive assembly 106, and a support structure 108. The plurality of PV modules 102 are coupled to the PV module mounting structure 104. The tracker drive assembly 106 is mounted on the support structure 108 and coupled to the PV module mounting structure 104.
[0033] In system 100, PV module mounting structure 104 is a torque tube (hereinafter referred to as torque tube 104). However, in other embodiments, the PV module mounting structure may include a box frame, a ladder frame, a space frame, or other frames or structures suitable for mounting PV modules.
[0034] The tracker drive assembly for a solar tracking system is configured to rotate a PV module mounting structure (e.g., a torque tube) through a number of different components. For example, the tracker drive assembly 106 includes a drive motor 110 that rotates a drive shaft (not shown). The tracker drive assembly 106 may also include one or more gears, shafts, and other internal components (not shown) to rotate the torque tube 104 and the plurality of PV modules 102 relative to the support structure 108. The gears in the tracker drive assembly 106 may include parallel axis gears, where the input shaft and the output shaft are parallel. Parallel axis gears include, but are not limited to, spur gears and helical gears. The gears in the tracker drive assembly 106 may also include non-parallel axis (intersecting and staggered axis) gears. Non-parallel axis gears change the axis of rotation between the input shaft and the output shaft, and include, but are not limited to, helical gears, worm gears, bevel gears, and miter gears.
[0035] Wind, uneven snow cover, seismic activity, and other events may cause torque to be applied to the tracker drive assembly through torque tube 104. This torque may cause damage to many different components of the solar tracking system 100, including but not limited to components of the tracker drive assembly, such as the drive motor and gears. To prevent the transfer of excessive torque, the tracker drive assembly 106 also includes at least one torque limiter (not shown). FIG2- Figure 6 Exemplary embodiments and implementations of a torque limiter are provided in the following.
[0036] Modifications, additions, or omissions may be made to the system 100 without departing from the scope of the present disclosure. For example, designating the various elements in the manner described is intended to help explain the concepts described herein and is not intended to be limiting. Furthermore, the system 100 may include any number of other elements or may be implemented in other systems or environments other than the ones described. For example, in other embodiments, the PV module mounting structure may include other structures other than a torque tube, such as a box frame, a ladder frame, a space frame, or other frames or structures for mounting PV modules.
[0037] Figure 2A-2E A spur gear 200 is shown, which may be Figure 1 A portion of the tracker drive assembly 106 is shown in FIG. Figure 2A Spur gear 200 is shown implemented in a tracker drive assembly, which also includes worm gear 202 . Figure 2B 2 is an exploded perspective view of the spur gear 200. Figure 2BAs shown, spur gear 200 includes an input shaft 204, a pinion 206, a toothed wheel 208, and an output shaft (not shown) located at the center of toothed wheel 208. In some embodiments, the output shaft can be a PV module mounting structure in a solar tracking system, such as a torque tube. Input shaft 204 is also the output shaft of worm gear 202. However, in other embodiments, the input shaft can be a drive shaft of a drive motor. The components of spur gear 200 are shown separated along the central axis 220 of input shaft 204.
[0038] The spur gear 200 further includes a spacer 210 including an inner surface 212 configured to be coupled to the outer surface 214 of the input shaft 204 and an outer surface 216 configured to be coupled to the inner surface 218 of the pinion 206. A friction ring 250 is interposed between the inner surface 218 of the pinion 206 and the outer surface 214 of the input shaft 204. More specifically, the friction ring 250 is interposed between the outer surface 216 of the spacer 210 and the inner surface 218 of the pinion 206.
[0039] The friction ring 250 can be configured to allow sliding or movement between the input shaft 204 and the pinion gear 206 when the torque between the input shaft 204 and the pinion gear 206 exceeds a threshold value. The friction ring 250 can include a plurality of sharp teeth 252 protruding from an outer surface 254 of the friction ring 250. The sharp teeth 252 can be configured to provide friction between the input shaft 204 and the pinion gear 206. The sharp teeth 252 on the friction ring 250 extend around the entire outer surface 254 and are divided into two separate rows. In other embodiments, there can be more or less than two separate rows. For example, the friction ring can have a single row or more than two rows of sharp teeth. In addition, the sharp teeth on the friction ring may not extend around the entire outer surface of the friction ring. Alternatively, there can be more space between adjacent sharp teeth, so that there are fewer sharp teeth on the friction ring.
[0040] The number of tines or other features on the friction ring may be directly related to the threshold amount of torque required for the friction ring to allow slipping. The circumference of the friction ring may also be directly related to the threshold amount of torque required for the friction ring to allow slipping. For example, as the circumference of the friction ring increases, the amount of torque required for the friction ring to allow slipping may also increase. Alternatively or additionally, to increase the amount of torque required for the friction ring to allow slipping, additional tines may be added to the friction ring, additional rows of tines may be added to the friction ring, or the material thickness of the friction ring may be increased.
[0041] Figure 2C A perspective view of the pinion 206 with the spacer 210 inserted is shown. The inner surface 212 is shaped to couple to Figure 2B The outer surface 214 of the input shaft 204 is shown. Figure 2CAlthough not visible, the friction ring 250 is disposed between the outer surface 216 of the spacer 210 and the inner surface 218 of the pinion 206. For example, Figure 2D A cross-sectional view of the pinion 206 inserted into the spacer 210 is shown, in which the friction ring 250 can be seen. The friction ring 250 is configured so that when the amount of torque between the pinion 206 and the spacer 210 exceeds a threshold, slippage will occur between these components. Figure 2E A cross-sectional view of the spur gear 200 along axis 220 is shown. In another embodiment, there may be no spacer. In this embodiment, a friction ring may be attached to the outer surface of the input shaft and placed between the input shaft and the pinion gear.
[0042] In some embodiments, two or more spur gears may be used to allow different segments of the PV module mounting structure to slide independently. For example, in one embodiment, an input shaft (which may be a drive shaft) may engage two independent toothed wheels via two independent pinions. A first friction ring may be placed between the input shaft and the first pinion, and a second friction ring may be placed between the input shaft and the second pinion. Each toothed wheel may be coupled to a different segment of the PV module mounting structure. The different segments of the PV module mounting structure may not have a direct connection, allowing each segment to slide independently of the other segments.
[0043] Figures 3A-3C A worm gear 300 is shown, which may be Figure 1 A portion of the tracker drive assembly 106 is shown in FIG. Figure 3A Worm gear 300 is shown implemented in a tracker drive assembly, which also includes spur gear 302 . Figure 3B 3 is an exploded perspective view of the worm gear 300. Figure 3B As shown, the worm gear 300 includes an input shaft 304, a worm 306 on the outer surface of the input shaft 304, a worm wheel 308, an output shaft 310 and a housing 312. The output shaft 310 is also the input shaft of the spur gear 302. In other embodiments, the output shaft 310 can be a PV module mounting structure, such as a torque tube. The input shaft 304 can also be a drive shaft of a drive motor. The components of the worm gear 300 are shown as separated along the central axis 320 of the output shaft 310.
[0044] The friction ring 350 is disposed between the inner surface 314 of the worm gear 308 and the outer surface 316 of the output shaft 310. The friction ring 350 can be configured to allow sliding or movement between the worm gear 308 and the output shaft 310 when the torque between the worm gear 308 and the output shaft 310 exceeds a threshold. The friction ring 350 can include a plurality of sharp teeth 352 protruding from the outer surface of the friction ring 350. The sharp teeth 352 can be configured to provide friction between the worm gear 308 and the output shaft 310. The sharp teeth 352 on the friction ring 350 extend around the entire outer surface of the friction ring 350 and span substantially the entire width of the friction ring 350. In other embodiments, two or more separate friction rings can be used to provide friction between moving parts.
[0045] Figure 3C A cross-sectional view of the worm gear 300 along axis 320 is shown. The circumference of the friction ring can also be directly related to the threshold torque amount required for the friction ring to allow slipping. For example, as the circumference of the friction ring increases, the amount of torque required for the friction ring to allow slipping can also increase. Therefore, an intermediate ring can be used to increase the circumference of the friction ring.
[0046] For example, Figure 4 A cross-sectional view along axis 320 of input shaft 304, worm 306 on the outer surface of input shaft 304, and output shaft 310 of worm gear 300 is shown. However, a worm wheel 408 having a larger diameter opening is used instead of worm wheel 308. In order to fill this additional space between output shaft 310 and worm wheel 408, intermediate ring 410 is coupled to output shaft 310. Friction ring 450 is interposed between intermediate ring 410 and output shaft 310. Since the circumference of friction ring 450 is greater than the circumference of friction ring 350, the threshold torque amount at which slip occurs between intermediate ring 410 and output shaft 310 is greater than the threshold torque amount at which slip occurs between worm wheel 308 and output shaft 310.
[0047] Figures 5A-5D Various views and components of an exemplary sun tracking system 500 are shown. Figure 5A As shown, system 500 includes a plurality of PV modules 502, a first PV module mounting structure segment 504a, a second PV module mounting structure segment 504b, a connector 506, a tracker drive assembly 508, and a support structure 510. In system 500, PV module mounting structure segment 504a and PV module mounting structure segment 504b are torque tube segments (hereinafter referred to as torque tube segment 504a and torque tube segment 504b, respectively). However, in other embodiments, the PV module mounting structure segments may include segments of a box frame, a ladder frame, a space frame, or other frames or structures suitable for mounting PV modules.
[0048] A plurality of PV modules 502 are coupled to torque tube segments 504a and 504b (the PV modules on torque tube segment 504b are lifted to better see the elements of the tracker drive assembly 508). A connector 506 couples the ends of the first torque tube segment 504a and the second torque tube segment 504b to form an elongated torque tube. The connector 506 may include a single component or multiple connected components. The tracker drive assembly 508 is mounted on a support structure 510 and is configured to rotate the connector 506 and the first torque tube segment 504a and the second torque tube segment 504b relative to the support structure 510. The tracker drive assembly 508 includes a drive motor 512 that rotates a drive shaft 514. The tracker drive assembly 508 also includes a worm gear 520.
[0049] Wind, uneven snow cover, seismic activity, and other events may cause torque to be applied to tracker drive assembly 508 through connection 506. This torque may cause damage to many different components of solar tracking system 500, including but not limited to components of worm gear 520, drive motor 512, and other components of tracker drive assembly 508.
[0050] Figure 5B A perspective view of the worm gear 520 and the connector 506 is shown, and Figure 5C An exploded perspective view of these components is shown. Figure 5C As shown, worm gear 520 includes housings 522a and 522b, worm gear 524, input shaft (which is also drive shaft 514), and worm 526 on the outer surface of drive shaft 514. The components of worm gear 520 are shown separated along the central axis 530 of connector 506.
[0051] To mitigate torque that may be generated on components of the worm gear 520, the drive motor 512, and other components of the tracker drive assembly 508, the tracker drive assembly 508 also includes a friction ring 550. The friction ring 550 is interposed between the inner surface 532 of the worm gear 524 and the outer surface 534 of the connector 506. The friction ring 550 can be configured to allow sliding or movement between the worm gear 524 and the connector 506 when the torque between the worm gear 524 and the connector 506 exceeds a threshold. The friction ring 550 can include a plurality of sharp teeth 552 protruding from the outer surface of the friction ring 550. The sharp teeth 552 can be configured to provide friction between the worm gear 524 and the connector 506. The sharp teeth 552 on the friction ring 550 extend around the entire outer surface of the friction ring 550 and span substantially the entire width of the friction ring 550. Figure 5D A cross-sectional view of the worm gear 520 along axis 530 is shown.
[0052] Without departing from the scope of the present disclosure, modifications, additions, or omissions may be made to the system 500. For example, the various elements are designated in the manner described to help explain the concepts described herein and are not intended to be limiting. In addition, the system 500 may include any number of other elements or may be implemented in other systems or environments other than the described systems or environments.
[0053] Figure 6 shows a structured Figure 5A 1 and 1. An exploded perspective view of another exemplary worm gear 600 and torque limiter of a sun tracking system is shown. Figure 6 As shown, the worm gear 600 includes housings 602a and 602b, a worm gear 604, an input shaft 606 (which may also be a drive shaft of a drive motor), a worm 608 on the outer surface of the drive shaft 606, a first connector component 610a, and a second connector component 610b. The first connector 610a and the second connector 610b may be configured to connect separate PV module mounting structure segments to form an elongated PV module mounting structure.
[0054] The torque limiter 650 may be positioned within the worm gear 600 to mitigate torque that may be generated on components of the worm gear 600 and other components of the tracker drive assembly of which the worm gear 600 is a part. The torque limiter 650 includes a first friction ring 652a and a second friction ring 652b. The first friction ring 652a is disposed between the inner surface 612 of the worm gear 604 and the outer surface 614a of the first connector component 610a. The second friction ring 652b is disposed between the inner surface 612 of the worm gear 604 and the outer surface 614b of the second connector component 610b. The first friction ring 652a and the second friction ring 652b may include a plurality of sharp teeth 654a and 654b protruding from the outer surfaces of the first friction ring 652a and the second friction ring 652b.
[0055] The first friction ring 652a can be configured to allow sliding or movement between the worm gear 604 and the first connector component 610a when the torque between the worm gear 604 and the first connector component 610a exceeds a threshold value. Similarly, the second friction ring 652b can be configured to allow sliding or movement between the worm gear 604 and the second connector component 610b when the torque between the worm gear 604 and the second connector component 610b exceeds a threshold value.
[0056] Since the first connector 610a and the second connector 610b are separate components, the PV module mounting structure segments they are connected to can slide independently of each other. In other words, the first connector 610a and the second connector 610b implement independent torque limitations of the first PV module mounting structure portion and the second PV module mounting structure portion coupled to the first connector 610a and the second connector 610b. Therefore, for example, if the torque between the worm gear 604 and the first connector component 610a exceeds a threshold value, while the torque between the worm gear 604 and the second connector component 610b does not exceed the threshold value, only the first friction ring 652a, whose torque exceeds the threshold value, will be allowed to slide.
Claims
1. A torque limiting mechanism in a solar tracking system, comprising: a drive motor configured to rotate the drive shaft; at least one gear configured to convert rotation of the drive shaft into rotation of a photovoltaic (PV) module mounting structure; and a torque limiter disposed between an inner surface of a first member of the at least one gear and an outer surface of a second member of the at least one gear, wherein the torque limiter is a friction ring configured to allow the first member to slide relative to the second member when an amount of torque between the first member and the second member exceeds a threshold value.
2. The torque limiting mechanism according to claim 1, wherein: The friction ring includes a plurality of pointed teeth protruding from a surface of the friction ring. 3 . The torque limiting mechanism of claim 1 , further comprising an intermediate ring interposed between the friction ring and at least one of the inner surface of the first component and the outer surface of the second component.
4. The torque limiting mechanism according to claim 1, wherein: The PV module mounting structure is a torque tube.
5. The torque limiting mechanism according to claim 1, wherein: The at least one gear is a parallel axis gear.
6. The torque limiting mechanism according to claim 5, wherein: The parallel axis gears include spur gears including a toothed wheel, a pinion, an input shaft, and an output shaft, and The friction ring is interposed between an inner surface of the pinion gear and an outer surface of the input shaft.
7. The torque limiting mechanism according to claim 6, wherein: The spur gear also includes a spacer having an inner surface and an outer surface, and The inner surface is coupled to the input shaft, and the friction ring is interposed between the outer surface of the spacer and the inner surface of the pinion gear.
8. The torque limiting mechanism according to claim 6, wherein: The input shaft is the drive shaft.
9. The torque limiting mechanism according to claim 6, wherein: The output shaft is the PV module mounting structure.
10. The torque limiting mechanism according to claim 1, wherein: The at least one gear is an intersecting axis gear.
11. The torque limiting mechanism according to claim 10, wherein: The intersecting axis gear includes a worm gear, the worm gear includes a worm wheel, a worm, an input shaft and an output shaft, and The friction ring is disposed between an inner surface of the worm gear and an outer surface of the output shaft.
12. The torque limiting mechanism of claim 11 further comprising a parallel axis gear with a pinion, wherein the input shaft is the drive shaft and the output shaft rotates the pinion of the parallel axis gear.
13. The torque limiting mechanism of claim 11, wherein: The output shaft includes a connector that couples the first PV module mounting structure segment to the second PV module mounting structure segment, and The friction ring is placed between the inner surface of the worm wheel and the outer surface of the connecting member.
14. The torque limiting mechanism according to claim 13, wherein: The connector includes a first connector component coupled to the first PV module mounting structure segment and a second connector component coupled to the second PV module mounting structure segment to allow independent torque limiting of the first and second PV module mounting structure segments.
15. The torque limiting mechanism according to claim 14, wherein: The friction ring includes a first ring disposed between an inner surface of the worm wheel and an outer surface of the first connector component, and a second ring disposed between an inner surface of the worm wheel and an outer surface of the second connector component.