Bidirectional output small-tooth difference speed reducer and speed reduction driving device

Abstract

The present application belongs to the field of photovoltaic tracking technology, and particularly relates to a bidirectional output small-tooth-difference speed reducer and a speed reduction driving device. The speed reducer comprises a shell, a torque output shaft, an external gear and an eccentric shaft. The torque output shaft is rotatably fitted at both ends of the shell. The external gear is arranged in the shell and is in transmission cooperation with the torque output shaft. The eccentric shaft is arranged in the external gear and drives the external gear to make trochoidal motion. The external gear is provided with external teeth one and coaxial external teeth two. The shell is provided with internal teeth one. The torque output shaft is provided with internal teeth two. The internal and external teeth are in meshing to make the torque output shaft rotate relative to the shell. Each meshing tooth is an arc-shaped tooth surface and has a specific tooth number difference. The driving device connects a power member to the eccentric shaft. The fixed end of the driving device is fixedly connected to the torque output shaft. The present application realizes coaxial bidirectional synchronous output, has a wide speed reduction ratio range, multiple tooth meshing, strong impact resistance, compact structure, excellent reverse self-locking characteristics, large torque, and is particularly suitable for application in photovoltaic tracking supports.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic tracking drive technology, and particularly relates to a bidirectional output low-tooth-difference reducer and a reduction drive device. Background Technology

[0002] In the field of photovoltaic power generation, photovoltaic tracking brackets are the core devices for improving the solar radiation reception efficiency of photovoltaic modules. Their drive system is usually composed of a drive motor and a reducer. The reducer transmits the motor power to the bracket by reducing speed and increasing torque, driving the bracket to complete the solar rotation tracking action. It is the key core component for the stable operation of the tracking bracket.

[0003] Currently, the mainstream reducer used in photovoltaic tracking brackets is the worm gear reducer. This type of reducer is widely used in the industry due to its certain self-locking performance. However, the inherent characteristics of its transmission structure and tooth profile design have gradually exposed many compatibility problems in the actual working conditions of photovoltaic tracking brackets, making it difficult to meet the high requirements of photovoltaic tracking systems for equipment reliability, durability and installation layout.

[0004] Traditional worm gear reducers have several technical shortcomings when applied to photovoltaic tracking brackets: First, their reverse self-locking capability and structural strength are insufficient. Photovoltaic tracking brackets need to maintain a fixed angle under strong winds. Due to the uneven distribution of wind loads, the reducer must withstand the large reverse holding torque brought by the wind load. However, worm gear reducers are limited by their structural volume, resulting in a low reverse holding torque. Under continuous wind loads, tooth root fracture is likely to occur, affecting the operational safety of the bracket. Second, their impact load resistance is weak. These reducers often use involute tooth profiles, and the tooth structure dimensions and strength are limited, making it difficult to withstand the periodic impact loads from wind loads. Repeated impacts can easily lead to transmission failure. Third, there are limitations in installation layout and synchronous transmission. The worm input shaft and worm output shaft are arranged in a spatial cross shape, which easily causes rotational interference with the photovoltaic module panel above. Furthermore, this structure cannot directly achieve synchronous linkage output of multiple reducers. Some improved solutions require the addition of a reversing gear mechanism, leading to structural complexity and reduced transmission efficiency. Fourth, the reduction ratio range is limited. To balance self-locking performance and transmission efficiency, the reduction ratio of worm gear reducers is typically designed to be around 50. However, photovoltaic tracking systems have extremely low output speed requirements, necessitating a higher reduction ratio to reduce the performance requirements of the drive motor. Traditional structures, limited by their design, cannot meet the need for large reduction ratios. Meanwhile, some improved cycloidal gear reducer solutions in the industry, while optimizing the transmission structure, suffer from structural complexity, insufficient pin strength, and an inability to independently achieve reverse self-locking, requiring an additional worm gear mechanism, further increasing equipment costs and failure rates.

[0005] The photovoltaic tracking bracket industry has increasingly higher demands for the compact structure, self-locking reliability, impact resistance and large reduction ratio of speed reducers. Traditional worm gear reducers and existing improved speed reducers cannot meet the above requirements at the same time, which has become a key factor restricting the development of lightweight, low cost and high reliability of photovoltaic tracking systems.

[0006] Therefore, there is an urgent need for a bidirectional output reducer with a small tooth difference and a reduction drive device to solve this problem. Summary of the Invention

[0007] The purpose of this invention is to provide a bidirectional output reducer with low tooth difference and a reduction drive device to solve the above-mentioned problems.

[0008] To achieve the above objectives, the present invention provides the following solution: A bidirectional output reducer with low tooth difference includes: The housing and torque output shafts are rotatably fitted at both ends of the housing. An external gear is provided inside the housing and is driven by the torque output shaft. An eccentric shaft is rotatably fitted inside the external gear. One end of the eccentric shaft is used to connect to a power input device. The eccentric shaft causes the external gear to perform cycloidal motion inside the housing.

[0009] The external gear has an external tooth 1, and external teeth 2 are symmetrically and coaxially fixed on both sides of the external tooth 1. The housing has an internal tooth 1 that is in transmission cooperation with the external tooth 1. The internal tooth 1 causes the external gear to rotate when it performs cycloidal motion.

[0010] The torque output shaft is provided with an internal gear that engages with the external gear.

[0011] While the second external tooth rotates and cycloidally along with the first external tooth, the second internal tooth causes the torque output shaft to rotate relative to the housing.

[0012] The number of teeth in the internal teeth is greater than the number of teeth in the external teeth.

[0013] Wherein, the number of teeth in the internal teeth is greater than the number of teeth in the external teeth.

[0014] There is a difference in the number of teeth between the first external tooth and the second external tooth.

[0015] Optionally, the difference between the number of teeth of the internal teeth and the number of teeth of the external teeth is 1.

[0016] Optionally, the difference between the number of teeth of the internal teeth and the number of teeth of the external teeth is 1.

[0017] Optionally, the difference between the number of teeth of the first external tooth and the number of teeth of the second external tooth is 1-3.

[0018] Optionally, the tooth surfaces of the first internal tooth, the second internal tooth, the first external tooth, and the second external tooth are all smooth arc surfaces.

[0019] Optionally, the eccentric shaft includes a second cylindrical surface and a first cylindrical surface eccentrically disposed at both ends of the second cylindrical surface. The first cylindrical surface rotates coaxially with the torque output shaft, and the second cylindrical surface rotates coaxially with the external gear.

[0020] The cylindrical surface 2 is rotatably fitted within the outer gear cavity opened on the outer gear by multiple second bearings.

[0021] Optionally, retaining ring grooves are respectively opened at both ends of the cylindrical surface two, and retaining rings are connected in the retaining ring grooves. An external gear inner hole step is provided in the middle of the inner cavity of the external gear. A space for installing the second bearing is formed between the retaining ring and the external gear inner hole step. The retaining ring and the external gear inner hole step cooperate to prevent the second bearing from axially moving.

[0022] Optionally, the cylindrical surface can rotate coaxially with the torque output shaft via a first bearing.

[0023] The speed reduction drive includes the aforementioned bidirectional output low-tooth-difference speed reducer, wherein one end of the eccentric shaft is connected to the output shaft of a power component, and the output shaft of the power component causes the eccentric shaft to rotate.

[0024] Optionally, the fixed end of the power component is fixedly connected to one of the torque output shafts.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects: In this invention, internal gear one, internal gear two, external gear one, and external gear two all adopt a circular arc tooth surface structure. The force angle of the tooth surface is precisely controlled within the self-locking angle range, achieving reliable reverse self-locking in conjunction with two-stage transmission. Furthermore, the circular arc transition design at the tooth root avoids stress concentration, enabling multiple teeth to mesh simultaneously at any rotation angle, thus distributing the load and significantly improving the reducer's reverse torque holding capability and impact resistance. For drive reducers used in photovoltaic tracking, reverse load holding torque is often the primary control condition for selection.

[0026] This invention utilizes the tooth difference between external gear one and internal gear one, and external gear two and internal gear two, to achieve two-stage low-tooth-difference speed reduction, achieving a wide range of reduction ratios from 80 to 500, precisely meeting the ultra-low speed requirements of photovoltaic tracking brackets. The invention employs a coaxial arrangement structure, with an integrated external gear driving the torque output shafts on both sides to rotate synchronously, achieving bidirectional synchronous output. The coaxial nature of the power input and output shafts naturally suits the multi-point linkage drive requirements of photovoltaic tracking brackets, eliminating the need for additional reversing gear structures. Under the same reverse torque holding design requirements, a smaller housing rotation radius can be achieved, effectively avoiding motion interference with the upper photovoltaic modules and adapting to compact installation layouts.

[0027] The eccentric shaft of this invention uses two bearings to precisely engage with the torque output shaft and the external gear, respectively, and is equipped with a retaining ring to limit the bearing movement, thereby improving the operational stability of the transmission components, reducing tooth surface wear and energy loss, and making the overall machine more efficient and stable in operation.

[0028] In this invention, the fixed end of the power component is fixed inside the torque output shaft and rotates synchronously with it. Since the output rotation angle of the photovoltaic tracking bracket is ±45 degrees or ±60 degrees east-west, it will not cause twisting or tangling of the power component cable. The power component can be built into the main beam of the photovoltaic tracking bracket, achieving effective protection for the power component, reducing the corrosive effects of external environments such as sunlight and rain, and extending the service life of the equipment. At the same time, it improves the overall coaxiality of the drive device, reducing vibration and noise during operation.

[0029] This invention features a compact overall structure, simplified components, and a rational and effective layout. Compared to worm gear reducers widely used in photovoltaic tracking systems, the structure employed in this patent application achieves significantly higher reverse holding torque for the same volume and specifications. Furthermore, its higher strength and safety margin enhance the overall operational reliability and service life of the equipment, perfectly meeting the outdoor heavy-duty and long-term stable operation requirements of photovoltaic tracking brackets. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a cross-sectional structural diagram of the speed reduction drive device of the present invention.

[0031] Figure 2 This is an exploded view of the deceleration drive device of the present invention.

[0032] Figure 3 This is a structural diagram of the internal structure of the speed reduction drive device of the present invention.

[0033] Figure 4 This is an exploded cross-sectional view of the internal structure of the deceleration drive device of the present invention.

[0034] Figure 5 This is a schematic diagram of the force under load when the internal and external teeth mesh synchronously.

[0035] Figure 6 This is a schematic diagram of the internal and external tooth structure of the present invention.

[0036] Figure 7 This is an exploded view of the housing and torque output shaft of the present invention.

[0037] Figure 8 This is an exploded view of the external gear and eccentric shaft of the present invention.

[0038] Figure 9 This is a schematic diagram of the shell structure of the present invention.

[0039] Figure 10 This is a schematic diagram of the torque output shaft structure of the present invention.

[0040] Figure 11 This is an assembly diagram of the speed reduction drive device of the present invention.

[0041] Among them, 01, housing; 02, torque output shaft; 03, external gear; 04, eccentric shaft; 05, split end cover; 06, self-lubricating bushing; 07, first bearing; 08, second bearing; 09, power component; 10, connecting component; 11, retaining ring; 12, first anchor; 13, second anchor; 14, plug; 15, first O-ring seal; 16, second O-ring seal; 17, third O-ring seal; 18, skeleton seal; 19, fourth O-ring seal; 0101, internal gear one; 0102, inner cylindrical surface one of housing; 0103, inner cylindrical surface two of housing; 0104, inner cylindrical surface three of housing; 0105, stepped end face one of housing; 0106, threaded hole on end face of housing; 0107, anchoring hole of base; 0108, housing base; 0109, reinforcing rib of base; 0110, weight reduction hole of housing; 0111 0112. Housing body; 0113. Housing reinforcing rib; 0201. Housing limiting step; 0202. Internal gear two; 0203. Output shaft inner cavity; 0204. Positioning step hole; 0205. Anchoring threaded hole; 0206. Threaded hole; 0207. Square tube mating surface; 0208. Output shaft cylindrical surface one; 0209. Output shaft cylindrical surface two; 0301. External gear one; 03 02. External gear II; 0303. External gear inner cavity; 0304. External gear inner hole step; 0401. Cylindrical surface I; 0402. Cylindrical surface II; 0403. Retaining ring groove; 0501. End cover anchoring hole; 0502. End cover inner cylindrical surface; 0503. End cover end face; 0504. End cover outer cylindrical surface; 0901. Power component mounting hole; 0902. Power component positioning step; 0903. Power component output shaft. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Reference Figures 1 to 11 This invention discloses a bidirectional output reducer with a small tooth difference, comprising: The housing 01 and the torque output shaft 02 are rotatably fitted at both ends of the housing 01. An external gear 03 is provided inside the housing 01. The external gear 03 is driven by the torque output shaft 02. An eccentric shaft 04 is rotatably fitted inside the external gear 03. One end of the eccentric shaft 04 is used to connect to the power input device. The eccentric shaft 04 causes the external gear 03 to perform cycloidal motion inside the housing 01.

[0045] Among them, the external gear 03 is provided with external tooth 0301, and external tooth 0302 is symmetrically and coaxially fixed on both sides of external tooth 0301. The housing 01 is provided with internal tooth 0101 that is in transmission cooperation with external tooth 0301. Internal tooth 0101 causes the external gear 03 to rotate when it performs cycloidal motion.

[0046] The torque output shaft 02 is equipped with an internal gear 0201 that is in transmission cooperation with the external gear 0302.

[0047] While external gear 2 0302 rotates and cycloidally moves with external gear 1 0301, internal gear 2 0201 causes the torque output shaft 02 to rotate relative to the housing 01.

[0048] Among them, the number of teeth in internal tooth 0101 is greater than the number of teeth in external tooth 0301.

[0049] Among them, the number of teeth in internal tooth 20201 is greater than the number of teeth in external tooth 20302.

[0050] There is a difference in the number of teeth between external gear 0301 and external gear 0302. The power input device drives the eccentric shaft 04 to rotate, and the eccentric shaft 04 drives the external gear 03 to perform cycloidal motion within the fixed housing 01. The internal gear 0101 inside the housing 01 meshes with the external gear 0301, causing the external gear 03 to rotate simultaneously with its cycloidal motion. The external gears 0302 on both sides of the external gear 03 rotate and cycloidally in sync with the external gear 0301. After meshing with the internal gears 0201 inside the torque output shaft 02, they drive the torque output shafts 02 at both ends of the housing 01 to rotate relative to each other around the central axis of the housing 01, thus achieving bidirectional power output. By matching the reasonable tooth number difference between internal tooth 1 0101 and external tooth 1 0301, internal tooth 2 0201 and external tooth 2 0302, and external tooth 1 0301 and external tooth 2 0302, a two-stage low tooth difference reduction transmission mechanism is formed, which achieves the transmission effect of speed reduction and torque increase as a whole. Moreover, the structure is arranged coaxially to ensure the synchronization of bidirectional output.

[0051] As an optional implementation, the difference in the number of teeth between the internal tooth 0101 and the external tooth 0301 is 1.

[0052] This 1-tooth difference design allows the external gear 03 to convert the high-speed rotation of the eccentric shaft 04 into the low-speed rotation of the external gear 03 when it performs cycloidal motion within the housing 01, achieving efficient speed reduction and torque increase in the first stage. Simultaneously, the 1-tooth difference ensures smooth meshing between the external gear 0301 and the internal gear 0101, and allows multiple teeth of the external gear 03 to mesh simultaneously at any rotation angle, effectively improving the load-bearing capacity and impact resistance of the first-stage transmission, thus meeting the heavy-duty requirements of photovoltaic tracking brackets.

[0053] As an optional implementation, the difference in the number of teeth between the internal gear 20201 and the external gear 20302 is 1.

[0054] The low-speed rotation of external gear 0302, generated by external gear 0301, is further reduced in speed and increased in torque through a one-tooth difference meshing engagement. The superposition of the two stages of one-tooth difference reduction achieves a wide range of large reduction ratios, meeting the ultra-low output speed requirements of photovoltaic tracking brackets. Simultaneously, this design ensures that external gear 0302 and internal gear 0201 maintain a multi-tooth meshing state, effectively distributing the transmission load, avoiding damage caused by excessive force on a single tooth, improving the operational reliability of the second-stage transmission, and precisely counteracting the eccentric cycloidal motion of external gear 03, ensuring the smooth coaxial rotation of the torque output shaft 02.

[0055] As an optional implementation, the difference in the number of teeth between external tooth 0301 and external tooth 0302 is 1-3.

[0056] This tooth difference design ensures the superposition of two-stage reduction and avoids interference during external gear machining. It ensures that the rotational reduction directions of external gear 0301 and internal gear 0101, and external gear 0302 and internal gear 0201, are consistent, achieving a product-based superposition of reduction ratios rather than motion cancellation. This guarantees the machine can achieve a wide range of reduction ratios from 80 to 500. Simultaneously, this tooth difference matching makes the overall tooth structure of the integrated external gear 03 more evenly stressed. The central external gear 0301 can be designed with a larger tooth thickness to bear the load transmitted by the external gears 0302 on both sides, significantly improving the overall structural strength and transmission stability of the external gear 03.

[0057] As an optional implementation, the tooth surfaces of internal tooth 1 0101, internal tooth 2 0201, external tooth 1 0301, and external tooth 2 0302 are all smooth arc surfaces.

[0058] The optimized design of the circular arc tooth profile ensures that the angle between the force direction and the sliding direction on the tooth surface is controlled within the self-locking angle range. Combined with a two-stage low-tooth-difference transmission structure, reliable reverse self-locking is achieved, meeting the angle maintenance requirements of photovoltaic tracking brackets under high-wind conditions. Simultaneously, the circular arc tooth root adopts a circular arc transition design, avoiding stress concentration at the tooth root and solving the problem of easy tooth root breakage in traditional involute teeth. Furthermore, the circular arc tooth structure ensures simultaneous contact of multiple teeth at any meshing angle, significantly improving the reducer's resistance to impact loads and torque carrying capacity, and extending the overall service life of the equipment.

[0059] This reducer includes three sets of gear meshing pairs: one is the meshing transmission formed by internal gear 0101 and external gear 0301, and the other is the meshing transmission formed by two sets of internal gear 0201 and external gear 0302 arranged symmetrically on the left and right.

[0060] Internal gear 0101 is disposed within the inner cavity of housing 01 and integrally formed with housing 01. Internal gear 0201 is disposed within the inner cavity of torque output shaft 02 and integrally formed with torque output shaft 02. External gear 03 is integrally formed by external gears 0302 on the left and right sides and external gear 0301 in the middle. The integral forming design is the preferred technical solution. Similarly, if the gear and housing are designed separately and then fixed by bolt anchoring, various keyway connections, inlay, or other methods, the internal and external gears are still within the protection scope of this invention.

[0061] The difference in the number of teeth between the internal tooth 0101 and the external tooth 0301 is preferably 1, that is, the number of teeth of the internal tooth 0101 minus the number of teeth of the external tooth 0301 equals 1.

[0062] The difference in the number of teeth between internal tooth 2 0201 and external tooth 2 0302 is preferably 1, that is, the number of teeth of internal tooth 2 0201 minus the number of teeth of external tooth 2 0302 equals 1. At the same time, a difference in the number of teeth is also provided between external tooth 1 0301 and external tooth 2 0302, which is preferably 2, that is, the number of teeth of external tooth 1 0301 minus the number of teeth of external tooth 2 0302 equals 2.

[0063] The external gear 03 consists of three sections: external tooth 0301 in the middle and external teeth 0302 on the left and right sides. The external teeth 0302 on the left and right sides have the same tooth shape and number of teeth, and the tooth phase angle is consistent.

[0064] Furthermore, since the load is concentrated from the two outer teeth 20302 on both sides to the middle outer tooth 10301, the tooth thickness of outer tooth 10301 is greater than that of outer tooth 20302. For ease of manufacturing, the root circle diameter of outer tooth 10301 is greater than or equal to the tip circle diameter of outer tooth 20302. The outer teeth 20302 on both sides are arranged with a predetermined axial spacing.

[0065] In this structure, the axial offset between the internal and external gears remains constant, and multiple pairs of teeth are simultaneously meshing at any meshing angle. For example... Figure 5 As shown by the middle arrow, this transmission mechanism has multiple sets of gear teeth meshing synchronously to bear clockwise or counterclockwise loads, which can effectively improve the torque bearing capacity and transmission stability of the gear pair.

[0066] The design of the internal and external tooth profiles is as follows: 1. The tooth profile of the external gear is derived from the tooth profile generation method of the cycloidal gear. The internal teeth are approximately conjugately fitted by the tooth surface of the external gear. In conjunction with the tooth surface design of this invention, the external tooth surface is divided into two parts: a convex tooth surface G and a concave tooth surface F. The convex tooth surface G serves as the main load-bearing working tooth surface and bears the main load during meshing.

[0067] 2. The internal gear tooth profile adopts a multi-segment circular arc combination structure that is adapted to and approximately fits the external gear tooth profile. Each segment of the circular arc is designed according to the meshing function zones: The outer arc A and the inner arc E are controlled by curvature to keep them separated from the external gear throughout the entire meshing cycle, thus avoiding excessive pressure angle that could lead to decreased efficiency and tooth surface interference.

[0068] The outer arc B and the inner arc D form a meshing transition section, achieving a smooth connection between the tooth surfaces from separation to meshing.

[0069] The curvature of the inner arc D is precisely matched with the convex tooth surface G of the external gear. Based on Hertzian contact stress theory, the tooth surface contact stress is reduced, thereby improving the load-bearing capacity.

[0070] The middle section C is the main meshing and bearing section, which maintains continuous contact with the external gear convex tooth surface G during operation.

[0071] 3. A constant shaft offset is set between the internal and external gears to ensure that multiple pairs of teeth mesh simultaneously at any meshing angle, so that the load is evenly distributed and the overall torque carrying capacity and transmission stability are improved.

[0072] 4. By combining the difference in the number of teeth between the internal and external teeth, the eccentricity, and the pressure angle range for comprehensive matching, while ensuring a large reduction ratio, the tooth surface contact strength, sliding rate, and transmission efficiency are optimized to achieve high load-bearing, smooth, and interference-free meshing transmission.

[0073] As an optional implementation, the eccentric shaft 04 includes a second cylindrical surface 0402 and a first cylindrical surface 0401 eccentrically disposed at both ends of the second cylindrical surface 0402. The first cylindrical surface 0401 rotates coaxially with the torque output shaft 02, and the second cylindrical surface 0402 rotates coaxially with the external gear 03.

[0074] The cylindrical surface 0402 is rotatably fitted into the external gear cavity 0303 on the external gear 03 via multiple second bearings 08.

[0075] Cylindrical surfaces 0401 are located at both ends of the eccentric shaft 04 and mate with the inner ring of the first bearing 07. The outer ring of the first bearing 07 is installed in the inner cavity 0202 of the output shaft to achieve radial support for the eccentric shaft 04.

[0076] Cylindrical surface 0402 is coaxially arranged with external gear 03 and housed within the internal cavity 0303 of external gear. The inner ring of the second bearing 08 mates with cylindrical surface 0402, and the outer ring mates with external gear 03. The second bearings 08 are spaced apart along the axial direction. The relative rotational speeds of cylindrical surface 0402 of eccentric shaft 04 and external gear 03 are different, and rolling contact between the two parts is achieved through the second bearings 08.

[0077] When the eccentric shaft 04 rotates, it drives the external gear 03 to oscillate through the second bearing 08. The retaining rings 11 are installed in the retaining ring grooves 0403 of the eccentric shaft 04, one on each side. The retaining rings 11 cooperate with the inner hole step 0304 of the external gear to restrict the axial movement of the second bearing 08 and achieve axial positioning.

[0078] The eccentric shaft 04 includes an eccentrically positioned cylindrical surface 0401 and a cylindrical surface 0402. Cylindrical surface 0401 rotates coaxially with the torque output shaft 02, and the torque output shaft 02 rotates coaxially with the housing 01, ensuring that the rotation center of the eccentric shaft 04 coincides with the overall center of the reducer. Cylindrical surface 0402 is rotatably fitted within the external gear cavity 0303 on the external gear 03 via multiple second bearings 08, providing stable radial support for the external gear 03. This allows the rotation of the eccentric shaft 04 to precisely drive the external gear 03 to perform regular cycloidal motion within the housing 01, preventing wobbling and vibration of the external gear 03. The axial arrangement of the multiple second bearings 08 also enhances the external gear 03's resistance to lateral bending moments, ensuring precise tooth meshing, reducing tooth surface wear, and improving overall transmission efficiency.

[0079] As an optional implementation, retaining ring grooves 0403 are respectively opened at both ends of the cylindrical surface 0402. The retaining ring 11 is connected in the retaining ring groove 0403. The inner cavity 0303 of the external gear is provided with an inner hole step 0304 of the external gear in the middle. The space for installing the second bearing 08 is formed between the retaining ring 11 and the inner hole step 0304 of the external gear. The retaining ring 11 and the inner hole step 0304 of the external gear cooperate to prevent the second bearing 08 from moving axially.

[0080] The cylindrical surface 0402 has retaining ring grooves 0403 at both ends, and retaining rings 11 are connected inside the retaining ring grooves 0403. The outer gear 03 has an outer gear inner hole step 0304 in the middle of its outer gear inner cavity 0303. The retaining ring 11 and the outer gear inner hole step 0304 form a dedicated space for installing the second bearing 08. The retaining ring 11 and the outer gear inner hole step 0304 cooperate to effectively prevent axial movement of the second bearing 08, ensuring that the second bearing 08 is always in the preset working position. This avoids deviation of the movement trajectory of the outer gear 03 due to bearing movement, preventing transmission failures such as tooth surface meshing interference and tooth wear. At the same time, this positioning structure makes the fit between the outer gear 03 and the eccentric shaft 04 more compact, improving the overall transmission rigidity, ensuring the synchronization of the cycloidal motion and rotation of the outer gear 03, and further improving the operating stability of the reducer.

[0081] As an optional implementation, the cylindrical surface 0401 rotates coaxially with the torque output shaft 02 via the first bearing 07.

[0082] The cylindrical surface 0401 of the eccentric shaft 04 rotates coaxially with the torque output shaft 02 via the first bearing 07, providing additional radial support for the eccentric shaft 04. This ensures stable support at both ends of the eccentric shaft 04, resulting in higher coaxiality during rotation and preventing deformation of the eccentric shaft 04 due to cantilever stress, thus guaranteeing the motion accuracy of the eccentric cylindrical surface 0402. Simultaneously, this connection method makes the relative rotation between the eccentric shaft 04 and the torque output shaft 02 smoother, reducing frictional losses and improving transmission efficiency. Because the eccentric shaft 04 and the first bearing 07 provide positional restraint to the torque output shaft 02, the rotation of the torque output shaft 02 is more stable, reducing a certain degree of oscillation.

[0083] To more clearly demonstrate the mating relationships of the parts, Figure 7 This demonstrates the mating structure between the torque output shaft 02 and the housing 01. The support and sealing structures of the torque output shafts 02 on both the left and right sides are identical.

[0084] Specifically, the torque output shaft 02 is coaxially arranged with the housing 01. The torque output shaft 02 rotates coaxially with respect to the housing 01. It is necessary to achieve radial support and axial limitation of the torque output shaft 02, and to withstand a certain overturning moment. The radial support of the torque output shaft 02 on each side is mainly achieved by two independent self-lubricating bushings 06, which cooperate with the housing 01 and rotate relative to it, and are assembled by the split end caps 05.

[0085] Each side of the split end cap 05 adopts an upper and lower split structure. Several first anchors 12, evenly distributed circumferentially, pass through the end cap anchoring holes 0501 and are fastened to the threaded holes 0106 on the end face of the housing, realizing the fixed connection between the split end cap 05 and the housing 01. The outer cylindrical surface 0504 of the end cap mates with the inner cylindrical surface 0104 of the housing to achieve the assembly positioning of the split end cap 05. The split structure facilitates assembly and installation. Since the inner diameter of the split end cap 05 is smaller than the outer diameter of the torque output shaft 02, the split structure can effectively avoid interference with the torque output shaft 02 during installation.

[0086] Two self-lubricating bushings 06 are arranged axially at a distance, respectively assembled on the inner cylindrical surface 0102 of the housing and the inner cylindrical surface 0502 of the end cover. The inner cylindrical surface of the self-lubricating bushing 06 forms a sliding fit with the cylindrical surface 0208 of the output shaft. The two self-lubricating bushings 06 have a predetermined axial spacing, which can improve radial support stability and withstand a certain overturning moment. The second cylindrical surface 0209 of the output shaft is located inside the third cylindrical surface 0104 of the housing. The stepped end face 0105 of the housing and the end face 0503 of the end cover cooperate with each other to achieve axial constraint on the torque output shaft 02, and at the same time improve the load-bearing capacity when subjected to overturning moment.

[0087] The first O-ring seal 15 is fitted into the groove of the first cylindrical surface 0208 of the output shaft, and the third O-ring seal 17 is fitted into the groove of the second cylindrical surface 0209 of the output shaft. Together with the skeleton seal 18, they form a multi-layered dynamic sealing structure for the torque output shaft 02. The second cylindrical surface 0103 inside the housing is used for the installation and positioning of the skeleton seal 18. The second O-ring seal 16 is positioned between the mating surfaces of the split end cap 05 and the housing 01, forming a static seal between the split end cap 05 and the housing 01 to prevent leakage of the sealing medium.

[0088] The torque output shaft 02 is supported by a double self-lubricating bushing 06 and fixed with a split end cap 05. This structure can effectively resist overturning bending moment and improve the stability of the rotational motion of the torque output shaft 02.

[0089] The torque output shaft 02 employs a multi-seal structure, with the first O-ring seal 15, the third O-ring seal 17, and the skeleton seal 18 working together to form a dynamic seal, and the second O-ring seal 16 forming a static seal, ensuring sealing reliability.

[0090] The reducer housing 01 serves as the installation reference and load-bearing base for the entire device. Its main structure and functions are as follows: The reducer housing 01 includes a cylindrical housing body 0111 and a housing base 0108, which are integrally formed to constitute the overall load-bearing frame of the housing. Base reinforcing ribs 0109 are located at the connection between the housing base 0108 and the housing body 0111 to ensure a stable connection and enhance the connection strength between the housing base and the housing body, thereby improving the overall deformation resistance of the housing. Housing reinforcing ribs 0112 are evenly distributed along the outer wall of the housing body 0111 to strengthen the structural rigidity of the housing body and prevent deformation of the housing under load during operation. Housing weight-reduction holes 0110 are formed on the housing body 0111 to achieve a lightweight design of the housing and reduce the overall weight of the device while ensuring the structural strength and load-bearing capacity of the housing.

[0091] The housing base 0108 is also provided with a base anchoring hole 0107.

[0092] An oil filling hole plug 14 is also connected to the housing body 0111.

[0093] The internal cavity of the reducer housing 01 integrates multiple functional structures to meet the installation, support, and transmission requirements of internal components. Internally, it features an internal gear 0101 for first-stage gear transmission, serving as a fixed meshing element for gear engagement. It also includes an inner cylindrical surface 0102, an inner cylindrical surface 0103, an inner cylindrical surface 0104, and a stepped end face 0105, all used for supporting, assembling, and positioning the torque output shaft 02, ensuring stable rotational movement of the torque output shaft 02. A threaded hole 0106 is formed on the end face of the housing 01, used for anchoring the split end cover 05 via a first anchor 12, providing a fixed reference for the split end cover 05. In addition, the housing 01 is provided with a housing limiting step 0113, which cooperates with the output shaft limiting step 0207 on the torque output shaft 02 to realize the rotation angle limit protection of the torque output shaft 02, prevent the torque output shaft 02 from being damaged by the component plate installed above due to the rotation angle exceeding the limit, and ensure the safe operation of the tracking bracket.

[0094] The torque output shaft 02, as the core component for torque transmission and output of the device, has the following main structure and functions: The inner cavity of the torque output shaft 02 integrates an internal gear 0201 for realizing the second-stage gear transmission. It also has an output shaft inner cavity 0202 to accommodate the first bearing 07 and provide an installation positioning reference, ensuring the stable assembly and operation of the first bearing 07. The torque output shaft 02 is provided with a positioning stepped hole 0203 and an anchoring threaded hole 0204. These two work together to achieve coaxial positioning and fixed anchoring with the power component 09, ensuring that the power component 09 and the torque output shaft 02 rotate synchronously and stably transmit torque.

[0095] The outer cylindrical surface of the torque output shaft 02 mainly includes output shaft cylindrical surface one 0208 and output shaft cylindrical surface two 0209. Output shaft cylindrical surface one 0208, located on both sides, forms a sliding fit with the self-lubricating bushing 06, jointly providing radial support for the torque output shaft 02. Due to the different diameters of the two cylindrical surfaces, the resulting left and right stepped end faces, in conjunction with the inner stepped surface of the reducer housing 01 and the end face of the split end cover 05, achieve axial positioning of the torque output shaft 02, ensuring the smooth rotational movement of the torque output shaft 02. The torque output shaft 02 is equipped with a square tube mating surface 0206 and a threaded hole 0205 for precise mating and secure anchoring with the external square tube main beam, ensuring reliable torque output from the device. Furthermore, the angular limiting of the torque output shaft 02 is achieved through the coordinated action of the output shaft limiting step 0207 and the housing limiting step 0113 of the housing 01: when the torque output shaft 02 is in the preset correct engagement position, the output shaft limiting step 0207 and the housing limiting step 0113 are in the same axial position. When the torque output shaft 02 rotates, as the rotation angle gradually increases, when the step surface of the output shaft limiting step 0207 and the step surface of the housing limiting step 0113 come into contact with each other, the rotation of the torque output shaft 02 is restricted and stopped, thereby achieving angular limiting protection for the torque output shaft 02. The output shaft limiting step 0207 on the torque output shaft 02 and the housing limiting step 0113 on the housing 01 cooperate to achieve limiting protection for the rotation angle of the torque output shaft 02, preventing excessive rotation damage and ensuring the safe operation of the device.

[0096] The speed reducer provided by this invention offers a superior reverse holding torque compared to traditional worm gear reducers of the same specifications. In practical applications of photovoltaic tracking brackets, the magnitude of the reverse holding torque is a core control factor in the selection of speed reducer specifications. The speed reducer provided by this invention, with its higher reverse holding torque, can further reduce the overall size of the speed reducer while meeting the self-locking requirements of the tracking bracket, effectively lowering the manufacturing cost of the speed reducer and the overall supporting cost of the photovoltaic tracking bracket.

[0097] This invention achieves stable and reliable reverse self-locking by coordinating a dual-output, two-stage reduction mechanism with a circular arc tooth meshing structure, and provides greater self-locking torque. Specifically, during the meshing operation of the internal and external teeth inside the reducer, the meshing tooth surfaces exhibit a low-slippage sliding friction motion. Since there is a preset angle between the force direction between the tooth surfaces and the tooth surface direction itself, this invention optimizes the tooth surface profile curve of the circular arc teeth to precisely control this angle within the self-locking angle range. After two-stage gear meshing reduction, experimental verification shows that stable and reliable reverse self-locking can be achieved. This self-locking mechanism is fundamentally different from the self-locking mechanism of traditional worm gear reducers commonly used in the photovoltaic tracking bracket field, solving the technical shortcoming of insufficient reverse holding torque in traditional worm gear reducers.

[0098] The limited reverse self-locking torque of worm gear reducers is mainly due to tooth root fracture induced by insufficient bending resistance of the worm gear teeth, resulting in a decrease in reverse load capacity. Compared with traditional worm gear reducers, the reducer proposed in this invention can provide greater reverse holding torque and impact load resistance under the same specifications, mainly due to the following three key technical features: First, the tooth structure design is more advantageous: the circular arc gear of this invention requires only 11 teeth to achieve reliable reverse self-locking, and has a larger reduction ratio compared to worm gears. In contrast, existing worm gear reducers used in photovoltaic tracking brackets generally require a reduction ratio of no less than 50, meaning the worm gear must have at least 50 teeth to meet the application design requirements of photovoltaic tracking. Under the premise of the same pitch circle diameter, the tooth body dimensions of the circular arc gear of this invention are much larger than those of the worm gear, significantly improving the tooth structure strength and effectively resisting the stress impact from reverse loads.

[0099] Secondly, traditional worm gear reducers suffer from insufficient reverse holding torque, which can lead to tooth root fracture and cause the collapse of the entire row of tracking supports, resulting in significant systemic damage. However, the self-locking principle and tooth structure employed in this invention are completely different from worm gears. Under extreme loads, the failure modes are tooth surface fatigue spalling due to excessive tooth surface contact stress, pitting, and localized tooth surface indentation. Since gears in the industry are generally made of ductile iron, the material's properties determine that its ability to withstand tooth surface contact stress and its compressive strength are far greater than its bending fracture strength. Even under extreme loads, systemic damage due to tooth root fracture will not occur.

[0100] Third, multi-tooth meshing enhances load capacity: During the meshing process of the inner and outer arc teeth in this invention, multiple pairs of teeth can simultaneously contact and share the load. This design is significant for improving the load-bearing capacity and reverse holding torque of the transmission system. By increasing the number of meshing contact teeth, the load during torque transmission can be effectively distributed, avoiding damage caused by excessive force on a single tooth. Simultaneously, it significantly improves the smoothness and reliability of the overall transmission process, further optimizing the reducer's impact resistance. Although worm gear reducers used in photovoltaic tracking can also achieve multi-tooth meshing transmission to some extent through an envelope tooth design, the width of the worm wheel is limited by the diameter of the worm due to the fit of the worm wheel and worm. The structure adopted in this invention, by widening the inner teeth, further improves the tooth load-bearing capacity.

[0101] To address the long-term reciprocating operation of photovoltaic (PV) tracking systems, this invention optimizes the structural layout, overcoming the shortcomings of traditional worm gear reducers that are prone to localized wear, and significantly improving the dynamic torque load and transmission reliability of the equipment. Reducers used in PV tracking typically cycle at ±45 degrees or ±60 degrees. Different operating angles correspond to different torsional eccentricities, and the dynamic load torque increases with the angle. For worm gear reducers, teeth at larger angles wear much more than teeth at smaller angles due to the greater load torque. The transmission structure adopted in this invention ensures that even at very small output angles, all teeth engage, resulting in uniform wear and a longer service life.

[0102] This invention adopts a more compact integrated structural design, which significantly reduces the number of parts, improves transmission stability, and reduces the failure rate.

[0103] The dual-output synchronous transmission is achieved by meshing the middle external gear 0301 with the internal gear 0101 to complete the first stage of reduction. The power is evenly transmitted to the two external gears 0302 at both ends, and then output synchronously by the torque output shafts 02 on both sides. The synchronous operation of the two sets of secondary reduction mechanisms can be achieved by a single external gear. The structure is compact and the transmission efficiency is high.

[0104] The improved operational stability and resistance to lateral bending moment are achieved by reserving an axial spacing between the two external gears 03 and 02 at both ends, allowing multiple second bearings 08 to be arranged along the axial direction to form multi-point radial support. This effectively ensures the stability of the external gear 03 during rotation, significantly improves its resistance to lateral bending moment, and reduces sway and vibration.

[0105] Eliminating assembly errors and ensuring synchronization accuracy is achieved by using a three-section structure for integrated machining. This ensures that the phase angles of the teeth of the two external gears 0302 at both ends are completely consistent, avoiding the cumulative errors caused by the assembly of multiple parts. This ensures that the rotation angles of the torque output shafts 02 on both sides are synchronized and that the transmission accuracy is higher.

[0106] The force transmission path is clear. Its static reverse holding torque is transmitted from the output shafts on both sides to the external gear 03, and then uniformly transmitted to the housing 01. The force transmission path is simple and clear, the overall structure is highly compact, effectively reducing the number of parts and improving the reliability of the whole machine.

[0107] The speed reduction drive includes the aforementioned bidirectional output low tooth difference speed reducer. One end of the eccentric shaft 04 is connected to the output shaft of the power component 09, and the output shaft of the power component 09 causes the eccentric shaft 04 to rotate.

[0108] This device connects the output shaft of the power component 09 to one end of the eccentric shaft 04. The power component 09 provides continuous and stable rotational power to the reducer. The rotation of the power component 09 directly drives the eccentric shaft 04 to rotate, which in turn drives the entire reducer transmission mechanism, consisting of the housing 01, external gear 03, and torque output shaft 02, to operate, realizing a complete transmission chain from power input to bidirectional reduction and torque increase output. This integrated design eliminates the need for additional transmission reversing components, making the overall structure of the reduction drive device more compact, the transmission path shorter, and energy loss lower, thus adapting to the compact installation requirements of photovoltaic tracking brackets.

[0109] As an alternative implementation, the fixed end of the power component 09 is fixedly connected to one of the torque output shafts 02.

[0110] By fixing the fixed end of the power component 09 inside one of the torque output shafts 02, the power component 09 and the torque output shaft 02 achieve synchronous rotational engagement. This allows the power component 09 to be integrated into the main beam of the photovoltaic tracking bracket, effectively protecting it from external environmental erosion such as sunlight, rain, and sandstorms, thus extending its service life. Simultaneously, this fixing method ensures higher coaxiality between the power component 09 and the reducer, resulting in more direct power transmission from the power component 09 to the eccentric shaft 04. This reduces vibration and noise caused by coaxiality deviations, further improving the operational stability of the reduction drive device and effectively preventing motion interference between the power component 09 and the upper photovoltaic module panel.

[0111] The power component 09 is fixed to the end flange face of the torque output shaft 02 by a number of second anchors 13. Specifically, the second anchors 13 pass through the power component mounting hole 0901 of the power component 09 and are tightened in the anchor thread hole 0204 of the torque output shaft 02, so that the body of the power component 09 and the torque output shaft 02 form a synchronous rotational fit.

[0112] The power component 09 and the torque output shaft 02 are arranged coaxially. The coaxial positioning and assembly guidance of the two are achieved by the power component positioning step 0902 on the power component 09 and the positioning step hole 0203 on the torque output shaft 02.

[0113] The fourth O-type seal 19 is installed between the mating end face of the power component 09 and the torque output shaft 02 to form a static sealing structure to ensure the sealing reliability of the assembly position.

[0114] The power output shaft 0903 is sleeved with the inner hole of the eccentric shaft 04, and the connecting piece 10 is respectively installed in the groove of the power output shaft 0903 and the inner hole groove of the eccentric shaft 04 to realize torque transmission.

[0115] The power output shaft 0903 is coaxially arranged with cylindrical surface 0401 and eccentrically arranged with cylindrical surface 0402.

[0116] This invention features a coaxial arrangement of the power input shaft and torque output shaft O2, resulting in a more compact structure and smaller overall size. This arrangement eliminates the need for additional radial offset space in the transmission mechanism, leading to a smaller overall size of the reducer. This allows it to fit within the limited installation space of a photovoltaic tracking system, avoiding motion interference with surrounding structures such as the upper module board and support beams, thus improving the flexibility and safety of the system layout. Furthermore, the shorter transmission path results in higher transmission efficiency. The coaxial arrangement of input and output reduces complex transmission steps such as commutation, eccentricity, and offsetting, making the power transmission path more direct and shorter, reducing energy loss, and significantly improving the overall transmission efficiency compared to traditional non-coaxial reducer structures.

[0117] Compared to traditional worm gear reducers, which are mostly arranged with staggered vertical axes, the coaxial input and output structure of this invention allows it to directly drive multiple supports in the same row in series in a photovoltaic tracking system. This eliminates the need for additional intermediate components such as commutators and angle boxes, simplifying the overall structure of the tracking transmission system and reducing costs and potential failure points.

[0118] The power component and the torque output shaft are coaxially arranged. The torque output shaft can be directly connected to the main beam of the tracking bracket and rotate synchronously. The power component can be housed inside the cavity of the main beam of the bracket, and the cavity of the main beam forms a closed protection to avoid external environmental erosion such as sun exposure, rain, and sandstorms, thereby improving the reliability and service life of the power component.

[0119] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0120] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A bidirectional output reducer with a small tooth difference, characterized in that, include: A housing (01) and torque output shafts (02) rotatably fitted at both ends of the housing (01). An external gear (03) is provided inside the housing (01). The external gear (03) is driven by the torque output shaft (02). An eccentric shaft (04) is rotatably fitted inside the external gear (03). One end of the eccentric shaft (04) is used to connect to a power input device. The eccentric shaft (04) causes the external gear (03) to perform cycloidal motion inside the housing (01). The external gear (03) is provided with external tooth 1 (0301), and external tooth 2 (0302) is symmetrically and coaxially fixed on both sides of external tooth 1 (0301). The housing (01) is provided with internal tooth 1 (0101) that is in transmission cooperation with external tooth 1 (0301). Internal tooth 1 (0101) causes the external gear (03) to rotate when it performs cycloidal motion. The torque output shaft (02) is provided with an internal gear (0201) that is in transmission cooperation with the external gear (0302). While the external tooth 2 (0302) rotates and cycloidally moves along with the external tooth 1 (0301), the internal tooth 2 (0201) causes the torque output shaft (02) to rotate relative to the housing (01). Wherein, the number of teeth of the inner tooth (0101) is greater than the number of teeth of the outer tooth (0301); Wherein, the number of teeth of the inner tooth 2 (0201) is greater than the number of teeth of the outer tooth 2 (0302); There is a difference in the number of teeth between the first external tooth (0301) and the second external tooth (0302).

2. The bidirectional output reducer with low tooth difference according to claim 1, characterized in that, The difference between the number of teeth of the inner tooth (0101) and the number of teeth of the outer tooth (0301) is 1.

3. The bidirectional output reducer with low tooth difference according to claim 1, characterized in that, The difference between the number of teeth of the inner tooth 2 (0201) and the number of teeth of the outer tooth 2 (0302) is 1.

4. The bidirectional output reducer with low tooth difference according to claim 1, characterized in that, The difference in the number of teeth between the first external tooth (0301) and the second external tooth (0302) is 1-3.

5. The bidirectional output reducer with a small tooth difference according to claim 1, characterized in that, The tooth surfaces of the first internal tooth (0101), the second internal tooth (0201), the first external tooth (0301), and the second external tooth (0302) are all smooth arc surfaces.

6. The bidirectional output reducer with low tooth difference according to claim 1, characterized in that, The eccentric shaft (04) includes a second cylindrical surface (0402) and a first cylindrical surface (0401) eccentrically disposed at both ends of the second cylindrical surface (0402). The first cylindrical surface (0401) rotates coaxially with the torque output shaft (02), and the second cylindrical surface (0402) rotates coaxially with the external gear (03). The cylindrical surface 2 (0402) is rotatably fitted within the external gear cavity (0303) opened on the external gear (03) by multiple second bearings (08).

7. The bidirectional output reducer with low tooth difference according to claim 6, characterized in that, The two ends of the cylindrical surface (0402) are respectively provided with retaining ring grooves (0403), and retaining rings (11) are connected in the retaining ring grooves (0403). The inner cavity of the external gear (0303) is provided with an external gear inner hole step (0304) in the middle. The space between the retaining ring (11) and the external gear inner hole step (0304) is formed for installing the second bearing (08). The retaining ring (11) and the external gear inner hole step (0304) cooperate to prevent the second bearing (08) from axially moving.

8. The bidirectional output reducer with low tooth difference according to claim 6, characterized in that, The cylindrical surface (0401) rotates coaxially with the torque output shaft (02) via the first bearing (07).

9. A speed reduction drive device, comprising a bidirectional output low-tooth-difference speed reducer as described in any one of claims 1-8, characterized in that, One end of the eccentric shaft (04) is connected to the output shaft of the power component (09), and the output shaft of the power component (09) causes the eccentric shaft (04) to rotate.

10. The speed reduction drive device according to claim 9, characterized in that, The fixed end of the power component (09) is fixedly connected to one of the torque output shafts (02).

Images