A reverse self-locking deceleration driving device

Abstract

The application relates to the field of photovoltaic tracking driving technology and provides a reverse self-locking deceleration driving device which comprises a transmission shaft, a shell, a first gear, two output shafts and a third gear, the two output shafts are symmetrically arranged at the two ends of the transmission shaft and coaxial with the shaft center of the transmission shaft, the first gear is eccentrically arranged on the transmission shaft and comprises a gear one and a gear two with different gear numbers, the output shaft is provided with a second gear which is engaged with the gear one, the third gear is eccentrically engaged with the gear two, and the eccentric directions of the two first gears engaged with the two output shafts are conjugate. Two-stage deceleration can realize large deceleration ratio output, the circular-arc teeth are matched to realize multi-tooth engagement bearing, the bearing torque is increased, the teeth are slidably and frictionally driven, and reverse large-torque self-locking of the output shaft is realized.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic tracking drive technology, and in particular to a reverse-locking deceleration drive device. Background Technology

[0002] In heavy-duty applications such as photovoltaic tracking systems, stringent requirements are placed on the performance of speed reducers. Traditional speed reducers suffer from insufficient torque retention and weak impact resistance when dealing with extreme conditions such as strong winds. Photovoltaic tracking brackets require drive devices with extremely high reverse self-locking and impact load resistance capabilities, while also meeting the operating characteristics of low-speed, intermittent motion. Existing speed reducers are insufficient in terms of structural compactness, reverse self-locking load retention, and service life to meet the reliability requirements of 25 years of continuous outdoor operation. Especially when dealing with strong wind conditions, it is necessary to overcome the weight of the components during normal operation and achieve short-term continuous operation under peak wind torque, which poses new challenges to the gear meshing method, torque transmission path, and overall structural strength of the speed reducer. When the tracking bracket encounters extreme wind conditions, the uneven distribution of wind loads causes the entire torque to be borne by the reduction mechanism, and commercially available tracking mechanisms often use worm gear reducers as the reduction drive device. Because worm gear reducers use involute teeth, and due to the size limitations of the worm gear reducer, each tooth has to bear a huge tangential load when subjected to reverse torque caused by strong winds. Tracking bracket failures caused by tooth root fractures occur frequently in actual projects.

[0003] Therefore, a reverse-locking deceleration drive device is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a reversible self-locking deceleration drive device, which has the advantages of high reversible self-locking capability, high torque output capability, excellent structural compactness, larger reduction ratio, and adaptability to intermittent motion and resistance to impact loads.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] According to an embodiment of the present invention, a reversible self-locking speed reduction drive device includes: a drive shaft, a housing, a first gear, two output shafts, and a third gear integrally formed with the housing. The housing has a mounting cavity extending through a horizontal direction. The drive shaft is mounted in the mounting cavity and extends along the through direction. The two output shafts are symmetrically arranged at both ends of the drive shaft, and the output shafts are coaxial with the axis of the drive shaft. The first gear is eccentrically mounted on the drive shaft. The first gear is configured as an external gear with circular arc teeth, including a gear one and a gear two with different numbers of teeth. A second gear is formed on the output shaft and meshes with the gear one. The third gear meshes eccentrically with the gear two. The second gear and the third gear are configured as internal gears with circular arc teeth, and the eccentric directions of the two first gears meshing with the two output shafts are conjugate.

[0007] The reversible self-locking speed reduction drive device according to embodiments of the present invention achieves a larger reduction ratio output through two-stage reduction. Combined with the application of circular arc teeth design, it enables multi-tooth meshing for load bearing, increasing the load-bearing torque and impact load resistance. The direct sliding friction transmission between the teeth enables high-torque self-locking of the output shaft in the reverse direction. This speed reduction device, applied to the drive structure of photovoltaic tracking brackets, can achieve greater torque output and reverse torque maintenance under low-speed, intermittent motion conditions, exhibiting significant advantages in adapting to harsher operating conditions such as strong winds.

[0008] In addition, the reversible self-locking speed reduction drive device according to the above embodiments of the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the circular arc tooth external gear includes a cycloidal surface of the external tooth, a transition surface of the external tooth, and a tooth tip surface of the external tooth. The cycloidal surface of the external tooth is determined by a curve generation equation. The tooth tip surface of the external tooth is set as a plane. The transition surface of the external tooth connects the cycloidal surface of the external tooth and the tooth tip surface of the external tooth, and makes the cycloidal surface of the external tooth and the tooth tip surface of the external tooth smoothly connected. The curve generation equation of the cycloidal surface of the external tooth is as follows:

[0010] ; Where X is the X-axis coordinate on the curve; Y is the Y-axis coordinate on the curve; e is the eccentricity; α is the angle, from 0 to 360 degrees; Z1 is the number of teeth of the internal gear meshing with the external gear; and R1 is the pitch circle radius of the internal gear.

[0011] In some embodiments of the present invention, the arc-tooth internal gear includes an arc surface of the internal teeth, a meshing surface of the internal teeth, and a transition surface of the internal teeth. The transition surface of the internal teeth is a smooth transition surface connecting two adjacent meshing surfaces of the internal teeth. Only a portion of the transition surface of the internal teeth participates in meshing with the external teeth. The meshing surface of the internal teeth is formed by fitting the cycloidal surface motion of the external teeth and smoothly transitions with the arc surface of the internal teeth. This portion of the surface is designed to increase the meshing contact area, reduce local contact stress, and improve the stability of reverse self-locking. The arc surface of the internal teeth is composed of arc surfaces with equal radii of curvature, ensuring multi-point contact with the external teeth and that the number of teeth meshing simultaneously at any rotation angle is not less than 3. The arc-tooth external gear and the arc-tooth internal gear exhibit sliding friction.

[0012] In some embodiments of the present invention, the number of internal teeth of the second gear is greater than the number of teeth of the first gear, the number of internal teeth of the third gear is greater than the number of teeth of the second gear, and the difference in the number of teeth between the inner gear with circular arc teeth and the outer gear with circular arc teeth is 1 tooth, and the difference in the number of teeth between the second gear and the third gear is 1 to 2 teeth.

[0013] In some embodiments of the present invention, a fourth gear is further included, which is installed inside the housing and fixedly mounted on the drive shaft between the two first gears, and the fourth gear drives the drive shaft to rotate.

[0014] In some embodiments of the present invention, a power component is also included. The power component is mounted on the housing. The housing has a through hole communicating with the mounting cavity. A fifth gear is fixedly mounted on the output end of the power component. The fifth gear passes through the through hole to transmit torque to the fourth gear.

[0015] In some embodiments of the present invention, a bracket and a sixth gear are also included. The bracket is mounted on the inner wall of the housing and located between the two first gears. The sixth gear is mounted on the bracket and meshes with the fourth gear and the fifth gear, respectively.

[0016] In some embodiments of the invention, a rotating shaft is also included, the rotating shaft being mounted on the bracket, and the sixth gear being rotatably mounted on the rotating shaft.

[0017] In some embodiments of the present invention, it further includes:

[0018] A first fixing member is installed between the fourth gear and the drive shaft to fix the fourth gear on the drive shaft;

[0019] The second fixing member is installed between the drive shaft and the first bearing, and the inner ring of the first bearing is fixedly installed on the drive shaft.

[0020] The third fixing component is installed between the output end of the power component and the fifth gear, thereby fixing the fifth gear on the output end of the power component.

[0021] In some embodiments of the present invention, it further includes:

[0022] A first bearing is mounted on the drive shaft, and the first gear is mounted on the drive shaft via the first bearing;

[0023] The second bearing is mounted on the output shaft and is located at the end of the transmission shaft. The inner ring of the second bearing cooperates with the transmission shaft to provide radial support for the transmission shaft.

[0024] A composite bushing is installed inside the housing, and the inner ring of the composite bushing cooperates with the outer ring of the output shaft to radially support the output shaft.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a reversible self-locking speed reduction drive device according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the reversible self-locking speed reduction drive device according to an embodiment of the present invention. Figure 1 ;

[0028] Figure 3 This is a schematic diagram of the structure of the reversible self-locking speed reduction drive device according to an embodiment of the present invention. Figure 2 ;

[0029] Figure 4 This is a schematic diagram of the structure of the reversible self-locking speed reduction drive device according to an embodiment of the present invention. Figure 3 ;

[0030] Figure 5 This is a schematic diagram of the structure of the reversible self-locking speed reduction drive device according to an embodiment of the present invention. Figure 4 ;

[0031] Figure 6 This is a schematic diagram of the structure of the reversible self-locking speed reduction drive device according to an embodiment of the present invention. Figure 5 ;

[0032] Figure 7 This is a schematic diagram of the arc gear structure of the reversible self-locking reduction drive device according to an embodiment of the present invention. Figure 1 ;

[0033] Figure 8 This is a schematic diagram of the arc gear structure of the reversible self-locking reduction drive device according to an embodiment of the present invention. Figure 2 .

[0034] Figure Labels

[0035] 101. Drive shaft; 102. First gear; 103. Output shaft; 104. Second gear; 105. Gear 1; 106. Gear 2; 107. Housing; 108. Mounting cavity; 109. Third gear; 110. Fourth gear; 111. Power component; 113. Fifth gear; 115. Sixth gear; 116. Rotating shaft; 117. First fixing component; 118. Second fixing component; 119. Third fixing component; 121. First bearing; 122. Second bearing; 124. Input shaft; 125. Third bearing; 126. First shaft retaining ring; 127. First O-ring Seals; 128. First skeleton seal; 129. Second O-ring seal; 130. Third O-ring seal; 131. First bolt; 132. First hole retaining ring; 133. Fourth bearing; 134. First spacer; 135. Second hole retaining ring; 136. Second shaft retaining ring; 137. Second spacer; 138. Third hole retaining ring; 139. First bushing; 140. Third shaft retaining ring; 141. Composite bushing; 142. First bearing housing; 143. Fifth bearing; 144. Fourth hole retaining ring; 145. Second skeleton seal; 146. Second bolt;

[0036] 201. Circular arc surface of internal tooth; 202. Meshing surface of internal tooth; 203. Transition surface of internal tooth; 204. Cycloidal surface of external tooth; 205. Transition surface of external tooth; 206. Tooth tip surface of external tooth. Detailed Implementation

[0037] The following description, in conjunction with the accompanying drawings, provides a more detailed account of a reversible self-locking speed reduction drive device according to the present invention, which illustrates preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0038] In the description of this specification, terms such as "one embodiment" or "some embodiments" mean that one or more embodiments of this specification include a particular feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0039] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] In existing technologies, photovoltaic tracking drive devices need to provide high reverse self-locking torque in windy environments while simultaneously ensuring long-term stable operation under low-speed, heavy-load conditions. Traditional reducers often employ worm gear structures, which suffer from excessively large axial dimensions and low transmission efficiency, making it difficult to balance high load-bearing capacity with a compact structure. Similar cycloidal gear reducers or reducers with few tooth differences have not been proven to possess reliable reverse self-locking capabilities. The cycloidal teeth and pin wheels in cycloidal gears rely on rolling friction, failing to form effective reverse self-locking. Furthermore, the excessive strength of the pin teeth and the high contact stress on the meshing surfaces affect the required load-bearing capacity. Reducers with few tooth differences, using involute tooth profiles, suffer from limited simultaneous meshing due to the limited number of teeth, impacting load-bearing capacity. Additionally, issues such as tooth root fracture make them unsuitable for photovoltaic tracking bracket applications.

[0041] To address the aforementioned issues, considering the requirements of the reducer for high static reverse self-locking torque under strong wind conditions and the need to withstand alternating loads under intermittent motion conditions, the load-bearing capacity was improved by optimizing the gear meshing method. Based on the 2K-H differential principle, an attempt was made to combine an eccentric mounting structure with a circular arc tooth profile to explore the feasibility of an asymmetric meshing relationship. By analyzing the meshing characteristics of the external and internal gears, it was found that during reverse rotation, the enveloping effect of the circular arc internal gear ring fitted with cycloidal teeth on the eccentric cycloidal external teeth, combined with relative sliding friction motion and after passing through two stages of gear reduction, can form an effective reverse self-locking mechanism. Therefore, a bidirectional symmetrical arrangement scheme was conceived to balance the vibration load and meet the bidirectional output requirements of the reducer in the tracking bracket.

[0042] Therefore, this invention proposes a reversible self-locking deceleration drive device, as detailed below with reference to the appendix. Figure 1-8 A reversible self-locking speed reduction drive device according to an embodiment of the present invention is described.

[0043] According to embodiments of the present invention, a reversible self-locking speed reduction drive device, such as... Figures 1-4 As shown, it includes: a drive shaft 101, a housing 107, a first gear 102, and two output shafts 103, as well as a third gear 109 integrally formed with the housing 107. The housing 107 has a mounting cavity 108 extending horizontally through it. The drive shaft 101 is installed in the mounting cavity 108 and extends along the through direction. The two output shafts 103 are symmetrically arranged at both ends of the drive shaft 101, and the output shafts 103 are coaxial with the drive shaft 101. The first gear... 102 is eccentrically mounted on the transmission shaft 101. The first gear 102 is configured as an external gear with circular arc teeth, including a gear 105 and a gear 106 with different numbers of teeth. A second gear 104 is formed on the output shaft 103 to mesh with the gear 105. The third gear 109 meshes eccentrically with the gear 106. The second gear 104 and the third gear 109 are configured as internal gears with circular arc teeth. The eccentric directions of the two first gears 102 meshing with the two output shafts 103 are conjugate.

[0044] The transmission shaft 101 refers to a rotating shaft that transmits power. It can be a hollow or solid shaft structure, specifically manufactured by forging alloy steel, and is used to support the gear set and transmit rotational motion. The output shaft 103 and the transmission shaft 101 are eccentrically mounted, meaning their axes have a predetermined offset distance. This can be achieved using an eccentric shaft or eccentric bearing, creating asymmetrical meshing conditions. A circular arc gear refers to a gear pair with a circular arc tooth profile. Specifically, cycloidal teeth or involute circular arcs can be used to modify the tooth profile, increasing the contact line length to enhance load-bearing capacity. The meshing of the external gear and internal gear refers to the meshing method of the external gear ring and the annular internal gear ring. Specifically, a double eccentric phase difference arrangement can be used, utilizing the staggered distribution of the tooth surface contact area to enhance the self-locking effect.

[0045] Specifically, the output shafts 103 at both ends of the transmission shaft 101 form symmetrically distributed power output points through eccentric mounting. The eccentric mounting of the first gear 102 creates a phase difference with the transmission shaft 101. When power is input, the meshing area of ​​the external and internal gears undergoes periodic changes under eccentric action, forming a dynamic contact surface. Under reverse load, the internal gear ring exerts an envelope constraint on the external gear, and the contact area of ​​the meshing gear pair expands with increasing load. The conjugate eccentricity, i.e., the eccentricity directions of the first gears 102 at the left and right ends meshing with the output shaft 103 are opposite, results in a 180-degree phase difference between the two meshing sides, causing vibration loads to cancel each other out on the transmission shaft 101. The contact surfaces of the arc-shaped internal and external teeth undergo sliding friction during operation, improving the stability of the reverse self-locking retention.

[0046] Compared to existing technologies, most speed reduction drive devices used in photovoltaic tracking systems employ worm gear transmission structures. While worm gears can achieve reverse self-locking, their limited reduction ratio and size make them prone to tooth root fracture when subjected to larger reverse torques, resulting in insufficient reverse holding torque. Similar structures include cycloidal gear reducers and low-tooth-difference reducers, but neither of these types has been proven to achieve effective reverse self-locking. The two-stage reduction structure used in this invention, combined with the design of circular arc teeth, allows the output shaft 103 to achieve reliable reverse holding torque. Compared to involute teeth, circular arc teeth can withstand greater loads without worrying about tooth root fracture. Furthermore, optimization through tooth profile fitting and other methods can further reduce tooth surface contact stress, improving the holding torque and impact load. The left and right output shafts 103 are symmetrically arranged to meet the dual output requirements of the tracking bracket. The first gear 102, which meshes with the output shaft 103, is symmetrically arranged in an eccentric direction, eliminating the eccentric load on the transmission shaft 101.

[0047] Through the above technical solution, this invention realizes the construction of a high-load-bearing transmission system within a limited space. The eccentric meshing of the external and internal gears generates a self-locking effect, and the unique shape characteristics of the circular arc teeth themselves enable it to withstand instantaneous impact loads greater than 20 kN·m. Compared with a worm gear reducer of the same volume, it can increase the reverse self-locking torque by nearly double, greatly improving the strength and reliability of the reduction device in high-wind conditions in photovoltaic tracking applications. Because photovoltaic tracking requires a speed of only 0.01 to 0.02 revolutions per minute for the reducer, the speed is extremely low. Furthermore, the relative slip ratio of the outer and inner teeth differs in different meshing regions. When the inner tooth's meshing surface 202 is engaged, the tooth bears a large load but has a low relative slip ratio. Conversely, on the inner tooth's arc surface, especially near the apex, the relative slip ratio is high, but the load is small. Simultaneously, through tooth profile optimization, the tooth is disengaged from the outer tooth's tip surface 206. Therefore, this characteristic ensures that the use of arc-shaped teeth fully meets the wear requirements of the photovoltaic tracking bracket at extremely low speeds. Combined with the material improvements of this invention, it fully meets the 25-year service life requirement of the photovoltaic tracking bracket.

[0048] In some embodiments of the present invention, such as Figure 3 , Figure 4 The first gear 102 includes a first gear 105 and a second gear 106. The first gear 105 meshes with the second gear 104. The second gear 106 is located away from the output shaft 103 and the first gear 105 and the second gear 106 are integrally formed. The number of teeth of the first gear 105 is less than the number of teeth of the second gear 106.

[0049] In this design, gear 105 is a transmission component that directly meshes with gear 104. It employs a circular arc tooth profile, with its number of teeth designed to be less than that of gear 104, preferably a difference of 1 tooth. The engagement of gear 105 and gear 104 constitutes the second stage of reduction at the output end. The first stage of reduction consists of gear 106 and gear 109, also employing a circular arc tooth design. Gear 106 has fewer teeth than gear 109, preferably a difference of 1 tooth. Similarly, gear 109 and gear 104 have a difference in the number of teeth, preferably 1 or 2 teeth. "Integral molding" means that gear 105 and gear 106 are formed into a single structure through forging and integral machining. Specifically, CNC machining can be used to ensure the coaxiality of the two gears, eliminating axial misalignment errors caused by separate assembly. "Difference in the number of teeth" refers to the different tooth ratios used by gear 105 and gear 106, forming the basis for multi-stage reduction transmission.

[0050] Specifically, when gear 105 meshes with gear 104, the smaller tooth difference design improves the single-stage reduction ratio, while the placement of gear 106 away from the output shaft 103 provides space for the subsequent meshing of gear 109. The integrated molding structure creates a rigid connection between gear 105 and gear 106, preventing relative displacement of the split gears under heavy loads and reducing accumulated errors during assembly. The meshing of gear 106 with gear 109 constitutes the first-stage reduction, while the meshing of gear 105 with gear 104 constitutes the second-stage reduction. These two stages of reduction create a larger reduction ratio and a reliable reverse self-locking structure.

[0051] Compared to existing technologies, such as worm gear reducers, which typically have a reduction ratio of around 50 in photovoltaic tracking, this invention achieves a reduction ratio of 300 or even higher through a two-stage reduction mechanism. This is advantageous for photovoltaic tracking applications requiring extremely low speeds. In contrast, a cycloidal gear reducer, being a single-stage reducer with an external gear output, requires a cantilever pin between the output shaft and the external gear to eliminate eccentricity due to the external gear's eccentric rotation. This significantly increases the number of parts and the risk to operational reliability. This invention, however, uses a two-stage reduction mechanism. Gear 106 (the second gear) engages eccentrically with the third gear 109 (which serves as a fixed internal gear), and the second gear 104 (part of the output structure) engages eccentrically with gear 105. This two-stage eccentricity simplifies the output structure, increases operational stability, and eliminates the need for a cantilever pin and the associated failures. This invention achieves multi-stage speed reduction by using an integrally molded double gear structure, while maintaining a compact layout.

[0052] Through the above technical solution, the present invention achieves a high reduction ratio superposition effect under axial space constraints. The difference in the number of teeth between gear one 105 and gear two 106 forms the initial reduction stage, while reserving expansion space for subsequent transmission chains. The one-piece molded structure ensures the gear assembly maintains overall rigidity under heavy loads, avoiding fatigue fracture of the split structure under alternating loads. The placement of gear two 106 away from the output shaft 103 effectively isolates the interference risk of different transmission stages, allowing multi-stage reduction to be transmitted orderly within a compact space.

[0053] The housing 107 refers to the support structure surrounding the transmission system, which can be integrally cast to support the internal transmission components and maintain the overall structural rigidity. The mounting cavity 108 refers to a through-hole structure extending along the horizontal axis, which can be formed into a cylindrical channel with a smooth inner wall through machining to ensure that the transmission shaft 101 rotates in a fixed direction along the axis. The third gear 109 refers to a ring-shaped gear structure fixed to the inner wall of the housing 107, integrally formed with the housing 107, and made of ductile iron containing alloying elements through isothermal quenching to improve the material strength and hardness. It forms the first stage of reduction through eccentric meshing with the second gear 106.

[0054] Specifically, the housing 107 serves as an integral support frame, providing a radial positioning reference for the transmission shaft 101 through the mounting cavity 108, eliminating radial offset caused by eccentric movement during transmission. The eccentric meshing relationship between the third gear 109 and the second gear 106, through periodically changing tooth surface contact areas, forms an alternating meshing state when the transmission shaft 101 rotates, ensuring uniform contact wear rather than localized tooth wear even for small-angle output circumferential teeth, while simultaneously dispersing load stress through multi-point alternating contact. Under reverse load, the meshing contact surfaces of the third gear 109 and the second gear 106, due to the axial deviation of the two teeth, create an angular difference between the direction of the force and the direction of rotation, forming a self-locking angle that prevents the transmission system from rotating in the opposite direction.

[0055] Compared to existing technologies, traditional worm gear drives correspond to specific teeth on the worm wheel at specific angles. Since different rotation angles in photovoltaic tracking result in varying loads, uneven tooth wear occurs. However, the structure of this invention ensures all teeth engage even at very small output angles, leading to more uniform wear. Furthermore, the internal third gear 109 and the housing 107 are integrally formed, resulting in a more compact structure and avoiding anchoring stability issues associated with separate designs. This invention achieves balanced dynamic load distribution while maintaining structural compactness through the integrated housing 107 and the eccentric meshing gear.

[0056] Through the above technical solution, this invention solves the problem of insufficient stability of the transmission system under heavy load conditions. The integrated design of the third gear 109 and the housing 107, as well as the integrated design of gear one 105 and gear two 106, reduces the anchoring connections of the main load-bearing components and improves the stability of the node connections. The eccentric meshing structure of the third gear 109, while increasing torque density, utilizes asymmetrical contact characteristics to achieve a reverse self-locking function, meeting the requirements of photovoltaic tracking systems to resist sudden wind load impacts. The phase difference compensation mechanism of the gear pair effectively reduces transmission errors, ensuring motion control accuracy under low-speed conditions.

[0057] It should be noted that the first gear 102, the second gear 104, and the third gear 109 are made of different materials to avoid scuffing of the internal and external teeth. For example, the external teeth are preferably made of bearing steel with a hardness of not less than HRC65 after quenching, while the internal teeth are made of quenched ductile iron. Due to the significant increase in strength and hardness, the wear resistance when mating with bearings is greatly improved, while avoiding the problem of tooth surface scuffing under frictional motion of the same material. The use of ductile iron for the internal teeth also facilitates integral casting with the housing 107 and the output shaft 103. After quenching, the surface is further improved and the surface roughness is reduced through shot peening and tumbling processes.

[0058] In some embodiments of the present invention, the circular arc tooth external gear (not shown in the figure) includes a cycloidal surface 204 of the external tooth, a transition surface 205 of the external tooth, and a tooth tip surface 206 of the external tooth. The cycloidal surface 204 of the external tooth is determined by a curve generation equation. The tooth tip surface 206 of the external tooth is set as a plane. The transition surface 205 of the external tooth connects the cycloidal surface 204 of the external tooth and the tooth tip surface 206 of the external tooth, and makes the cycloidal surface 204 of the external tooth and the tooth tip surface 206 of the external tooth smoothly connected. The curve generation equation of the cycloidal surface 204 of the external tooth is as follows:

[0059] ; Where X is the X-axis coordinate on the curve; Y is the Y-axis coordinate on the curve; e is the eccentricity; α is the angle, from 0 to 360 degrees; Z1 is the number of teeth of the internal gear meshing with the external gear; and R1 is the pitch circle radius of the internal gear.

[0060] The cycloidal surface 204 of the external tooth refers to the tooth profile surface generated by mathematical equations. Specifically, it can be defined using equations including parameters such as eccentricity, number of teeth of the internal gear, and pitch circle radius, to ensure precise conjugate meshing between the tooth profile and the internal gear. The transition surface 205 of the external tooth refers to the geometric structure connecting the cycloidal surface and the tooth tip surface. Specifically, it can be implemented using a surface with continuously changing curvature to eliminate abrupt curvature changes at the tooth profile connection. The tooth tip surface 206 of the external tooth refers to the planar region at the top of the gear tooth. Specifically, it can be implemented using a machining plane perpendicular to the gear axis to reduce stress concentration at the tooth tip. The eccentricity e in the curve generation equation refers to the axial offset between the external and internal gears. Specifically, this parameter can be adjusted to control the envelope range of the tooth meshing trajectory. The angle α ranges from 0 to 360 degrees to fully generate the cycloidal tooth profile of a single tooth. The number of teeth Z1 and pitch circle radius R1 of the internal gear are introduced into the equations to match internal gear pairs of different specifications.

[0061] Specifically, the tooth profile surface of the outer circular arc tooth is generated as follows:

[0062] The tooth profile of the external circular arc tooth is generated by a curved surface produced by the curve equation and offset by an equal distance δ in the direction of the arrow.

[0063] The equation of the curve that generates the surface is as follows:

[0064] ; X — The X-axis coordinate on the curve;

[0065] Y—The Y-axis coordinate on the curve;

[0066] e – eccentricity;

[0067] α – Angle, from 0 to 360 degrees;

[0068] Z1 — The number of teeth of the internal gear that meshes with the external gear;

[0069] R1—Pitch circle radius of the internal gear;

[0070] Determination and optimization of eccentricity In this technical solution, the preferred value for the eccentricity coefficient K1 is between 0.6 and 0.7, which can achieve a larger self-locking torque. The tooth profile shapes corresponding to different eccentricity coefficients are shown in the attached figure.

[0071] The distance δ from the curve generated by the curve equation to the tooth profile surface is determined and optimized. K2 is the tooth diameter coefficient of the internal gear. Since the internal and external gears have different material strengths, optimizing the tooth diameter coefficient can reduce the contact stress at the meshing point and achieve equal strength design for the internal and external teeth. The preferred value for the tooth diameter coefficient δ is between 1.65 and 1.8.

[0072] Generation of the internal tooth profile: The internal tooth profile consists of three curved surfaces: the internal tooth's circular arc surface 201, the internal tooth's meshing surface 202, and the internal tooth's transition surface 203. The internal tooth's circular arc surface 201 is an arc-shaped circle, and the radius of the arc-shaped circle... The meshing surface 202 of the internal tooth has a radius of curvature similar to that of the cycloidal surface of the external tooth. When the cycloidal angle Φ = arccos(K1), the bearing capacity of the meshing tooth is at its maximum. The meshing surface 202 of the internal tooth meshes with the cycloidal surface 204 of the external tooth at this meshing angle, which can achieve a larger contact area and reduce surface contact stress. The transition surface 203 of the internal tooth is a transition surface from the meshing disengagement state to the meshing state. Considering ease of machining, the radius of curvature of this surface is usually not smaller than the arc surface 201 of the internal tooth.

[0073] Similarly, the tooth profile of the external circular arc tooth is also composed of three curved surfaces: the cycloidal surface 204 of the external tooth, the transition surface 205 of the external tooth, and the tooth tip surface 206 of the external tooth. The cycloidal surface 204 of the external tooth, as described above, meshes with the circular arc surface 201 and the meshing surface 202 of the internal tooth within a certain cycloidal angle Φ. The preferred cycloidal angle of this meshing segment is usually within 100 degrees, ensuring simultaneous meshing of 5-6 teeth. The transition surface 205 of the external tooth, composed of one or more circular arcs with a certain radius of curvature, serves as the transition segment from the separated state to the meshing state of the meshing teeth. The tooth tip surface 206 of the external tooth is in a separated state from the internal circular arc tooth.

[0074] Furthermore, the angle between the pressure load direction at each meshing position and the tooth movement direction is the meshing angle β. The meshing angle is different for different meshing tooth positions. The meshing angle applied to the tooth profile design of this invention is usually not less than 45 degrees. At the same time, sliding friction is used between the inner and outer teeth. When the two output shafts 103 are subjected to reverse torque, the component force load of the outer arc tooth rotating in the opposite direction is small due to the large meshing angle between the teeth. Considering the resistance load caused by the large frictional sliding, the two-stage gear transmission will have reliable self-locking.

[0075] In other words, the cycloidal surface is generated through parametric equations, enabling a precise conjugate relationship between the external gear tooth profile and the internal gear, thus achieving simultaneous contact of multiple teeth during meshing. The transition surface connects the cycloidal surface and the tooth tip surface through continuous curvature variation, avoiding localized stress concentrations caused by geometric abrupt changes during meshing. The planar tooth tip surface simplifies the machining process and reduces contact stress in the tooth tip region. During transmission, the cycloidal tooth profile of the external gear and the meshing surface of the internal gear are dynamically matched through equation parameters, ensuring a uniform load distribution under different meshing phases. By adjusting the eccentricity and tooth number difference, the contact area of ​​the tooth surface can be optimized, thereby improving the load-bearing capacity of the gear pair.

[0076] Compared to existing technologies, reducers with small tooth difference often employ involute tooth profiles, where the tooth surface contact area is concentrated in the single or double tooth meshing region, easily leading to stress concentration and localized wear. In contrast, cycloidal surfaces, generated through mathematical equations, enable simultaneous meshing of multiple teeth, distributing the load across multiple tooth surfaces. The continuous curvature design of the transition surface avoids the stress abrupt changes caused by the direct connection between the cycloidal and straight segments in traditional tooth profiles. Furthermore, the planar tooth tip surface, compared to the traditional circular arc tooth tip surface, reduces machining difficulty and the stress peak at the tooth tip edge.

[0077] Through the above technical solutions, this application improves the load distribution characteristics during gear meshing, reduces stress concentration on the tooth surface, and minimizes tooth surface wear under extreme conditions. The precise cycloidal tooth profile design enhances transmission accuracy and stability, extending the service life of the gear pair under heavy-load intermittent motion conditions. The smooth connection design of the transition surface effectively suppresses vibration and noise during meshing, enhancing the reliability of the reduction gear under impact load conditions.

[0078] In some embodiments of the present invention, the arc-tooth internal gear (not shown in the figure) includes an arc surface 201 of the internal teeth, a meshing surface 202 of the internal teeth, and a transition surface 203 of the internal teeth. The transition surface 203 of the internal teeth is a smooth transition surface connecting two adjacent meshing surfaces of the internal teeth. Only a portion of the transition surface 203 of the internal teeth participates in meshing with the external teeth. The meshing surface 202 of the internal teeth is formed by fitting the cycloidal surface motion of the external teeth and smoothly transitions with the arc surface. This portion of the surface is designed to increase the meshing contact area, reduce local contact stress, and improve the stability of reverse self-locking. The arc surface 201 of the internal teeth is composed of arc surfaces with equal radii of curvature, ensuring multi-point contact with the external teeth and that the number of meshing teeth at any rotation angle is not less than 3. The arc-tooth external gear and the arc-tooth internal gear are subject to sliding friction.

[0079] The meshing surface 202 of the internal teeth refers to the meshing surface that matches the cycloidal trajectory of the arc-tooth external gear. Specifically, it can be formed using a five-axis CNC machining center to maximize the contact area during meshing. The arc-tooth surface 201 of the internal teeth refers to the contact area of ​​multi-point meshing. Specifically, it can be improved by carburizing and quenching to withstand contact stress under alternating loads. The transition surface 203 of the internal teeth refers to the smooth transition surface connecting two adjacent meshing surfaces of the internal teeth. Specifically, it can be designed with a variable radius arc transition for the transition section from contact to separation when meshing with the internal teeth. The requirement of at least three meshing teeth is a mandatory constraint condition achieved through tooth profile parameter optimization. Specifically, tooth tip modification technology can be used to avoid tooth contact at excessively large pressure angles, thus reducing contact stress and wear. Sliding friction refers to the motion mode where the tooth surfaces maintain surface contact. Specifically, high-viscosity grease that increases surface contact stress can be used to reduce the wear rate and improve transmission smoothness.

[0080] Specifically, the meshing surface 202 of the internal tooth is generated through reverse engineering. Based on the cycloidal motion trajectory of the external tooth, a three-dimensional scan and fitting are performed to form a conjugate meshing surface. This surface is divided into the main load-bearing areas of the tooth. By adopting a conjugate surface design, the contact area is increased, and local contact stress concentration is reduced. Tooth surface damage caused by surface contact stress concentration is the main failure mode of arc-shaped teeth. This design can significantly increase the load-bearing capacity of the tooth. The arcuate surface 201 of the internal tooth smoothly transitions to the meshing surface 202 of the internal tooth, consisting of arcs with equal radii of curvature. This area can simultaneously contact the cycloidal surface 204 of the external tooth at different meshing phase angles, ensuring multi-point meshing. The sliding friction fit uses ductile iron containing self-lubricating material and a high-viscosity lubricating grease containing molybdenum disulfide to form a boundary lubrication layer between the tooth surfaces, maintaining the necessary frictional self-locking torque while avoiding excessive wear.

[0081] Compared to existing technologies, low-tooth reducers often use involute teeth, which have low tooth strength, resulting in a limited number of teeth capable of simultaneous meshing and insufficient load-bearing capacity. Traditional cycloidal wheel designs often employ single-stage reduction, where the internal teeth use pin-shaped pins. The rolling friction between the pin and the cycloidal wheel does not create reverse self-locking, and the pin's inherent strength makes it unsuitable for applications requiring resistance to large impact loads in photovoltaic tracking. This solution, however, utilizes a multi-tooth synchronous meshing structure to distribute the load across more than three contact teeth, significantly improving instantaneous overload capacity. As the load-bearing capacity increases, the number of meshing teeth also increases. This solution employs a sliding friction surface contact design, increasing the contact area within the same dimensions, while utilizing multi-tooth meshing to reduce wear and increase load-bearing capacity.

[0082] Through the above technical solution, this application can maintain the synchronous meshing of at least three teeth when the photovoltaic tracking system encounters strong winds, effectively dispersing peak torque loads and preventing tooth surface overload damage. The sliding friction-coordinated multi-tooth load-bearing structural design ensures the reverse self-locking torque while extending the service life of the gear pair by optimizing the contact stress distribution. The continuous curvature variation characteristics of the transition surface ensure a smooth transition of the teeth from the disengaged state to the meshing state, enabling the gear to maintain stable operation even under intermittent and frequent start-stop conditions.

[0083] In some embodiments of the present invention, the number of internal teeth of the second gear 104 is greater than the number of teeth of the first gear 105, the number of internal teeth of the third gear 109 is greater than the number of teeth of the second gear 106, and the difference in the number of teeth between the inner gear with circular arc teeth and the outer gear with circular arc teeth is 1 tooth, and the difference in the number of teeth between the second gear 104 and the third gear 109 is 1 to 2 teeth.

[0084] The difference in the number of teeth between the internal and external circular arc gears is 1 tooth, meaning the internal gear has 1 more tooth than the external gear. Specifically, this can be achieved by having the external gear with 39 teeth and the internal gear with 40 teeth. This design creates a multi-tooth meshing state through a small difference in the number of teeth. The difference in the number of teeth between the second gear 104 and the third gear 109 is 1 to 2 teeth, meaning the difference in the number of teeth between the two gear pairs is stepped. Specifically, this can be achieved by having the second gear 104 with 40 teeth and the third gear 109 with 41 or 42 teeth. This range of difference allows more internal and external teeth to contact simultaneously, increasing the load-bearing capacity of the teeth.

[0085] Specifically, when the difference in the number of teeth between the external gear and the internal gear is 1 tooth, for every revolution of the external gear, the internal gear experiences a phase shift of one tooth, forcing the meshing point to move continuously along the tooth surface, forming a multi-tooth simultaneous meshing effect. The difference in the number of teeth between the second gear 104 and the third gear 109 is controlled within the range of 1 to 2 teeth, ensuring that the meshing phases of the two gear pairs are staggered. During reverse transmission, since there is a certain angle between the force direction on the tooth surface and the contact direction of rotation, and as mentioned above, the internal and external teeth use conjugate curved surfaces to increase the contact area, the angle in some areas is kept within the friction angle range, thus achieving a self-locking function. During intermittent motion, the stepped tooth difference distribution allows different gear pairs to alternately bear the load, avoiding continuous impact on the same tooth surface area and reducing the local wear rate.

[0086] Through the above technical solutions, this application solves the problem of insufficient reverse self-locking load retention in traditional reducers under extreme operating conditions, increasing the self-locking torque to more than 10 times the rated output torque. Impact resistance is enhanced through multi-tooth meshing and phase dispersion, reducing tooth surface contact stress when subjected to instantaneous impacts. The stepped tooth number difference design causes the wear area of ​​the gear pair to shift periodically, extending the service life to twice that of traditional designs under the same operating conditions, meeting the reliability requirements of 25 years of continuous operation for photovoltaic tracking systems. Transmission smoothness under intermittent motion conditions is improved through phase complementarity, reducing the vibration amplitude of the gear pair.

[0087] In some embodiments of the present invention, such as Figure 1 , Figures 3-6 As shown, it also includes a fourth gear 110, which is installed inside the housing 107 and fixedly mounted on the transmission shaft 101 between the two first gears 102. The fourth gear 110 drives the transmission shaft 101 to rotate.

[0088] The fourth gear 110 refers to a transmission component with an external tooth structure, which can be implemented using an involute gear. Its tooth surface undergoes carburizing and quenching treatment to improve its load-bearing capacity. This gear is rigidly fixed to the transmission shaft 101 via a keyway fit or flange connection, forming a direct power transmission path.

[0089] Fixed installation refers to a connection method in which there is no relative rotation between the gear and the transmission shaft 101. Specifically, it can be achieved by using the first fixing member 117 to ensure that no axial displacement occurs during power transmission.

[0090] The first gear 102 refers to the middle section of the transmission shaft 101 along the axial direction. Specifically, it can be set at an axially symmetrical position of 30% to 50% of the total length of the transmission shaft 101. The two first gears 102 are eccentric to the transmission shaft 101, and the first gears 102 on both sides are arranged conjugately 180 degrees eccentrically.

[0091] In some embodiments of the present invention, such as Figures 1-6 As shown, it also includes a power component 111, which is mounted on the housing 107. The housing 107 has a through hole (not shown) communicating with the mounting cavity 108. The fifth gear 113 is fixedly mounted on the output end of the power component 111, and the fifth gear 113 passes through the through hole to transmit torque to the fourth gear 110.

[0092] The power component 111 refers to a drive device that provides rotational power, specifically a DC motor (preferably) or a stepper motor. Its output end is connected to the fifth gear 113 via a third fixing component 119 to achieve synchronous rotation. The through hole refers to a through-hole structure provided on the wall of the housing 107, specifically a pre-cast structure, with its maximum size slightly larger than the outer diameter of the fifth gear 113 for easy assembly. The fifth gear 113 refers to a gear component that meshes with the fourth gear 110, specifically a spur gear or helical gear made of carburized and quenched steel, with its tooth profile parameters matching those of the fourth gear 110. The fourth gear 110 refers to a power input gear fixedly mounted on the transmission shaft 101, with its tooth surface ground to improve transmission accuracy.

[0093] Specifically, the power component 111 is installed on the outer surface of the housing 107 by means of bolt fastening or other methods, forming a stable mounting base, such as... Figure 5 As shown, the power component 111 is fixed to the housing 107 by the second bolt 146. The mounting cavity 108 inside the housing 107 communicates with the external environment through the through hole, and the teeth of the fifth gear 113 extend through this channel into the mounting cavity 108. The power component 111 and the fifth gear 113 rotate synchronously using a keyway fit, and the rotational torque is transmitted to the drive shaft 101 through the meshing contact surface between the fifth gear 113 and the fourth gear 110. The lubricating grease in the mounting cavity 108 is isolated from the journal of the fifth gear 113 by a seal provided between the through hole and the journal of the fifth gear 113, preventing external contaminants from entering the transmission system.

[0094] In some embodiments of the present invention, such as Figure 1 , Figures 3-6 As shown, it also includes a sixth gear 115, which is installed in the mounting cavity 108 and meshes with the fourth gear 110 and the fifth gear 113 respectively.

[0095] The sixth gear 115 can be installed in the mounting cavity 108 using a bracket (not shown in the figure). The bracket refers to a support structure used to fix the sixth gear 115. The bracket can also be integrally formed with the housing.

[0096] The sixth gear 115 refers to a gear used as an intermediate transmission gear, which is a spur or helical gear that transmits torque by simultaneously meshing with the fourth gear 110 and the fifth gear 113.

[0097] Specifically, the bracket is mounted on the inner wall of the housing, forming a stable support base. The sixth gear 115 is installed on the bracket, and its teeth mesh with the fourth gear 110 and the fifth gear 113, respectively. When the power component 111 drives the fifth gear 113 to rotate, torque is transmitted to the fourth gear 110 through the sixth gear 115, thereby driving the transmission shaft 101 to rotate. In this process, the sixth gear 115 serves as a transition node in the torque transmission path.

[0098] In some embodiments of the present invention, such as Figure 5 , Figure 6 As shown, it also includes a rotating shaft 116, which is installed in the mounting cavity 108, and the sixth gear 115 is rotatably mounted on the rotating shaft 116.

[0099] The rotating shaft 116 refers to a rigid shaft used to support the rotational motion of the sixth gear 115. Specifically, it can be implemented by using a stepped shaft or a smooth shaft combined with a keyway structure. Its two ends are fixed in the mounting holes of the bracket by interference fit or threaded connection, providing stable radial positioning for the sixth gear 115.

[0100] The sixth gear 115 is rotatably mounted on the rotating shaft 116, meaning that the inner hole of the gear and the outer surface of the rotating shaft 116 form a clearance fit or a rolling bearing connection. Specifically, a deep groove ball bearing or a sliding bearing can be used to achieve this, so that the sixth gear 115 can rotate freely around the axis of the rotating shaft 116 while restricting axial displacement.

[0101] Specifically, the bracket, as the supporting structure of the transmission system, directly affects the gear meshing accuracy due to its rigidity. The rotating shaft 116 is fixed to a predetermined position on the bracket via a mechanical connection, forming a stable reference line for the rotating shaft 116. The sixth gear 115 is mounted on the rotating shaft 116 via a bearing assembly. When transmitting torque between the fourth gear 110 and the fifth gear 113, the rotating shaft 116 bears the radial load generated by gear meshing. When there are assembly errors or load fluctuations in the transmission system, the sixth gear 115 can perform slight self-adjustment around the rotating shaft 116 to eliminate uneven distribution of contact stress on the tooth surface.

[0102] In some embodiments of the present invention, it further includes:

[0103] First fastener 117, such as Figure 6 As shown, the first fixing member 117 is installed between the third gear 109 and the transmission shaft 101, and the fourth gear 110 is fixed on the transmission shaft 101.

[0104] Second fastener 118, such as Figure 2As shown, the second fixing member 118 is installed between the drive shaft 101 and the first bearing 121, and the first bearing 121 is fixedly installed on the drive shaft 101;

[0105] Third fastener 119, such as Figure 5 As shown, the third fixing member 119 is installed between the output end of the power member 111 and the fifth gear 113, fixing the fifth gear 113 on the output end of the power member 111.

[0106] The first fixing member 117 is a torque transmission structure used to connect the drive shaft 101 and the fourth gear 110. Specifically, it can be implemented using a combination of keyway and flat key, with the flat key transmitting the torque of the fourth gear 110 to the drive shaft 101. The second fixing member 118 is used for torque transmission between the inner ring of the first bearing 121 and the drive shaft 101. The first bearing 121 is designed as an eccentric bearing, and its axial positioning on the drive shaft 101 is achieved through a spacer and a retaining ring. The third fixing member 119 is used to transmit torque between the input shaft 124 and the fifth gear 113, transmitting the power torque of the power component 111 to the fifth gear 113 to drive its rotation.

[0107] Specifically, a keyway is machined on the mating surface of the transmission shaft 101 and the fourth gear 110 and a flat key is installed. A stepped shoulder is machined on the transmission shaft 101 at the mounting position of the first bearing 121, and a retaining ring groove is opened on the other side of the shoulder to install an elastic retaining ring, so that the inner ring of the bearing is precisely limited within the axial range.

[0108] It should be noted that the first fixing member 117, the second fixing member 118 and the third fixing member 119 can also be any other structural member that can achieve the above-mentioned fixing function, such as a flat key, a positioning pin, etc., which will not be described in detail here.

[0109] In some embodiments of the present invention, the reduction ratio between the output end of the power component 111 and the output shaft 103 can be arbitrarily set, wherein the reduction ratio is preferably greater than 100, and different gear differences and tooth number ratios can form a large range of reduction ratios.

[0110] The reduction ratio refers to the ratio of the rotational speed at the output end of the power component 111 to the rotational speed of the output shaft 103. This is achieved using a multi-stage gear transmission structure; in this invention, a two-stage planetary gear reduction mechanism with a small tooth difference is employed. This parameter range setting allows the high-speed rotation of the power source to be converted into ultra-low-speed motion at the output end, while simultaneously meeting heavy-load requirements through torque amplification.

[0111] Specifically, when the high-speed rotation output by the power component 111 is transmitted to the output shaft 103 via a multi-stage reduction mechanism, the reduction ratio reaches or exceeds 100, thus controlling the rotational speed of the output shaft 103 within the range of 0.01-0.03 revolutions per minute. During this process, the low torque at the input end is amplified step-by-step through gear meshing, ultimately forming the peak torque required by the photovoltaic tracking bracket at the output end. Since the reduction ratio is directly related to the gear tooth ratio, a high reduction ratio can be achieved within a limited space using a multi-stage reduction structure. Simultaneously, the mechanical self-locking effect generated by gear meshing prevents the output shaft 103 from rotating in the opposite direction.

[0112] This invention combines a specific reduction ratio range with a multi-stage transmission structure to achieve both speed control and torque amplification without the need for an additional braking mechanism. It also utilizes the friction of the transmission system itself to achieve reverse self-locking, and the use of arc teeth increases the reverse self-locking retention capability.

[0113] Through the above technical solution, the present invention achieves the requirement of extremely low output speed of photovoltaic tracking drive device by realizing a large reduction ratio in a compact structure. At the same time, within the limited size specifications, reliable reverse self-locking holding torque is achieved through the design of arc teeth and two-stage reduction structure. The application of arc teeth ensures multi-point meshing during operation and at rest, and avoids the risk of tooth root breakage, thus meeting the strength requirements of photovoltaic tracking bracket for drive device under strong winds.

[0114] In some embodiments of the present invention, such as Figure 2 As shown, it also includes:

[0115] A first bearing 121 is mounted on the drive shaft 101, and a first gear 102 is mounted on the drive shaft 101 via the first bearing 121;

[0116] The second bearing 122 is mounted on the output shaft 103 and disposed near the end of the transmission shaft 101. The inner ring of the second bearing 122 cooperates with the transmission shaft 101 to avoid interference between the transmission shaft 101 and the output shaft 103.

[0117] A composite bushing 141 is installed inside the housing, and the inner ring of the composite bushing 141 cooperates with the outer ring of the output shaft 103 to radially support the output shaft 103.

[0118] The first bearing 121 is a rolling support component installed between the transmission shaft 101 and the first gear, specifically a deep groove ball bearing or a cylindrical roller bearing, which provides low-friction support for the eccentric rotation of the first gear. The second bearing 122 is a positioning component located at the joint between the output shaft 103 and the transmission shaft 101, specifically an angular contact ball bearing or a tapered roller bearing, whose inner ring is interference-fitted with the transmission shaft 101 to constrain the radial displacement of the output shaft 103. The composite bushing 141 is a radial support component made of a self-lubricating material, specifically a PTFE-based composite material and a metal matrix composite structure, whose inner ring forms a clearance-fit sliding support interface with the outer surface of the output shaft 103.

[0119] Specifically, the rolling elements of the first bearing 121 form rolling contact between the transmission shaft 101 and the first gear, converting the sliding friction generated by the eccentric motion of the gear into rolling friction. The inner ring of the second bearing 122 forms a rigid connection with the transmission shaft 101, establishing an axial positioning reference at the end of the output shaft 103 and eliminating the relative radial offset between the transmission shaft 101 and the output shaft 103. The inner ring surface of the composite bushing 141 maintains a constant clearance with the outer circle of the output shaft 103, absorbing the radial load fluctuations of the output shaft 103 during eccentric motion through elastic deformation, while maintaining the stability of the support interface by utilizing the low friction characteristics of the self-lubricating material. The support system composed of these three components forms multi-point constraints in the transmission shaft 101 system, balancing the periodic load generated by eccentric motion through the synergistic effect of rolling and sliding supports.

[0120] Compared with existing technologies, traditional reduction gears typically use a single deep groove ball bearing to support the drive shaft 101, which is prone to increased bearing clearance and support failure under eccentric loads. Existing bushing structures are mostly single metal bushings, lacking elastic compensation capabilities and having a high coefficient of friction. This solution, through the combined design of rolling bearings and the composite bushing 141, achieves flexible load transmission while maintaining transmission accuracy, effectively suppressing shaft deformation.

[0121] Through the above technical solution, this application maintains the coaxiality of the transmission shaft 101 and the output shaft 103 under heavy-load impact conditions, reduces the friction loss caused by gear eccentricity, and compensates for the radial displacement of the output shaft 103 through the elastic support of the composite bushing 141. This solves the problem of abnormal gear meshing caused by insufficient support stiffness during the reverse self-locking process of traditional structures, and significantly improves the operational reliability of the speed reduction device under intermittent impact loads.

[0122] It should be noted that the first bearing 121 and the second bearing 122 can be eccentric bearings to achieve the eccentric design of the first gear 102 and the output shaft 103. Alternatively, the first bearing 121 and the second bearing 122 can be non-eccentric bearings, while the transmission shaft 101 is set as an eccentric structure to achieve the eccentric design of the first gear 102 and the output shaft 103. Furthermore, the eccentric setting of the first gear 102 and the output shaft 103 can also be achieved by combining the first bearing 121, the second bearing 122 and the transmission shaft 101, which will not be elaborated here.

[0123] In summary, one embodiment of the reversible self-locking speed reduction drive device is as follows: Figures 1-8 As shown:

[0124] The power component 111 provides driving torque, which drives the fourth gear 110 to rotate via the sixth gear 115 through the fifth gear 113, wherein the fourth gear 110 transmits torque to the drive shaft 101 through the first fixing member 117.

[0125] The power component 111 transmits torque to the input shaft 124 via the third fixing component 119. The input shaft 124 is radially supported by a third bearing 125, one of which is fixed inside the mounting cavity 108, and the other is fixed to the first bearing seat 142. The input shaft 124 is connected to the fifth gear 113 via the third fixing component 119, transmitting torque and driving the fifth gear 113 to rotate. A first shaft retaining ring 126 is used to prevent axial movement. A first O-ring seal 127 and a first skeleton seal 128 provide dynamic torsional sealing for the input shaft 124. A second O-ring seal 129 provides static sealing for the first bearing seat 142, and a third O-ring seal 130 seals the power component 111.

[0126] The fifth gear 113 meshes externally with the sixth gear 115. The rotation direction of the sixth gear 115 is opposite to that of the fifth gear 113. It is mounted on the rotating shaft 116 via a fourth bearing 133. The rotating shaft 116 is fixed inside the mounting cavity 108 by a first bolt 131. A retaining ring 132 axially fixes the fourth bearing 133 in the first hole. A first spacer 134 prevents axial movement of the sixth gear 115.

[0127] The sixth gear 115 meshes externally with the fourth gear 110, transmitting torque from the fifth gear 113, and ultimately transmitting the torque to the drive shaft 101 via the first fixing member 117 to drive the circular arc gear. The fifth bearing 143 is fixed inside the mounting cavity 108, providing radial support for the drive shaft 101, and a retaining ring 135 is used for axial fixation of the second hole. A second shaft retaining ring 136 and a second spacer 137 axially fix the fourth gear 110, preventing axial movement of the fourth gear 110.

[0128] The two output shafts 103 are symmetrically structured. A second gear 104 is housed within each output shaft 103, meshing with gear 105 of the first gear 102. The first gear 102 is driven by the first bearing 121 and oscillates eccentrically relative to the centerline of the transmission shaft 101. Another part of the first gear 102, gear 106, meshes with a third gear 109 located in the mounting cavity 108, forming a two-stage gear reduction output. The inner ring of the first bearing 121 is connected to the transmission shaft 101 via the second fixing member 118 and is driven by the transmission shaft 101 to rotate eccentrically around its axis. The first bearing 121 is mounted in the cavity of the first gear 102 and axially fixed by a retaining ring 138. A first bushing 139 and a third retaining ring 140 are used for axial fixation of the first gear 102. A composite bushing 141 provides radial support to the output shaft 103 and is installed inside the mounting cavity 108. The composite bushing 141 is preferably made of a self-lubricating composite material. The fifth bearing 143 is installed in the internal cavity of the output shaft 103 for radial support of the drive shaft 101. The fourth hole retaining ring 144 is used to limit the axial movement of the output shaft 103, and the second skeleton seal 145 is used for dynamic rotational sealing of the output shaft 103.

[0129] It should be noted that in this invention, during the meshing process of the arc-shaped gears, multiple pairs of teeth participate in meshing simultaneously at any meshing angle, and the pressure angle also varies with the change of the meshing angle. By controlling the pressure angle of the meshing teeth through measures such as tooth profile modification, and in conjunction with the two-stage reduction transmission structure mentioned in this technical solution, self-locking retention of the output teeth at any angle can be achieved.

[0130] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A reversible self-locking speed reduction drive device, characterized in that, include: The system comprises a drive shaft, a housing, a first gear, two output shafts, and a third gear integrally formed with the housing. The housing has a mounting cavity extending horizontally through the drive shaft. The drive shaft is mounted in the mounting cavity and extends along the through direction. The two output shafts are symmetrically arranged at both ends of the drive shaft and are coaxial with the drive shaft axis. The first gear is eccentrically mounted on the drive shaft and is configured as an external gear with circular arc teeth, including a gear one and a gear two with different numbers of teeth. A second gear is formed on the output shaft to mesh with the gear one. The third gear meshes eccentrically with the gear two. The second gear and the third gear are configured as internal gears with circular arc teeth, and the eccentric directions of the two first gears meshing with the two output shafts are conjugate.

2. The reversible self-locking speed reduction drive device according to claim 1, characterized in that, The circular arc tooth external gear includes a cycloidal surface of the external tooth, a transition surface of the external tooth, and a tooth tip surface of the external tooth. The cycloidal surface of the external tooth is determined by a curve generation equation. The tooth tip surface of the external tooth is set as a plane. The transition surface of the external tooth connects the cycloidal surface of the external tooth and the tooth tip surface of the external tooth, and makes the cycloidal surface of the external tooth and the tooth tip surface of the external tooth smoothly connected. The curve generation equation of the cycloidal surface of the external tooth is as follows: ; Where X is the X-axis coordinate on the curve; Y is the Y-axis coordinate on the curve; e is the eccentricity; α is the angle, from 0 to 360 degrees; Z1 is the number of teeth of the internal gear meshing with the external gear; and R1 is the pitch circle radius of the internal gear.

3. The reversible self-locking speed reduction drive device according to claim 2, characterized in that, The circular arc tooth internal gear includes a circular arc surface of the internal teeth, a meshing surface of the internal teeth, and a transition surface of the internal teeth. The transition surface of the internal teeth is a smooth transition surface connecting two adjacent meshing surfaces of the internal teeth. Only a portion of the transition surface of the internal teeth participates in meshing with the external teeth. The meshing surface of the internal teeth is formed by fitting the cycloidal surface motion of the external teeth and smoothly transitions with the circular arc surface of the internal teeth. The circular arc surface of the internal teeth is composed of circular arc surfaces with equal radii of curvature, and the number of teeth meshing simultaneously at any rotation angle is not less than 3. The circular arc tooth external gear and the circular arc tooth internal gear experience sliding friction.

4. The reversible self-locking speed reduction drive device according to claim 1, characterized in that, The number of internal teeth of the second gear is greater than the number of teeth of the first gear, the number of internal teeth of the third gear is greater than the number of teeth of the second gear, and the difference in the number of teeth between the inner and outer arc-tooth gears is 1 tooth, while the difference in the number of teeth between the second gear and the third gear is 1 to 2 teeth.

5. The reversible self-locking speed reduction drive device according to claim 1, characterized in that, It also includes a fourth gear, which is installed inside the housing and fixedly mounted on the drive shaft between the two first gears, and the fourth gear drives the drive shaft to rotate.

6. The reversible self-locking speed reduction drive device according to claim 5, characterized in that, It also includes a power component, which is mounted on the housing. The housing has a through hole that communicates with the mounting cavity. A fifth gear is fixedly mounted on the output end of the power component. The fifth gear passes through the through hole to transmit torque to the fourth gear.

7. The reversible self-locking speed reduction drive device according to claim 6, characterized in that, It also includes a bracket and a sixth gear, the bracket being mounted on the inner wall of the housing and located between the two first gears, the sixth gear being mounted on the bracket and meshing with the fourth gear and the fifth gear respectively.

8. The reversible self-locking speed reduction drive device according to claim 7, characterized in that, It also includes a rotating shaft mounted on the bracket, and the sixth gear is rotatably mounted on the rotating shaft.

9. The reversible self-locking speed reduction drive device according to claim 8, characterized in that, Also includes: A first bearing is mounted on the drive shaft, and the first gear is mounted on the drive shaft via the first bearing; The second bearing is mounted on the output shaft and disposed near the end of the drive shaft. The inner ring of the second bearing cooperates with the drive shaft to provide radial support to the drive shaft. A composite bushing is installed inside the housing, and the inner ring of the composite bushing cooperates with the outer ring of the output shaft to radially support the output shaft.

10. The reversible self-locking speed reduction drive device according to claim 9, characterized in that, Also includes: A first fixing member is installed between the fourth gear and the drive shaft to fix the fourth gear on the drive shaft; The second fixing member is installed between the drive shaft and the first bearing, and the inner ring of the first bearing is fixedly installed on the drive shaft. The third fixing component is installed between the output end of the power component and the fifth gear, thereby fixing the fifth gear on the output end of the power component.

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