A multi-point engagement compound planetary gear reducer, drive wheel set and robot drive module

Abstract

The present application belongs to the technical field of speed reducer, and particularly relates to a multi-point meshing composite planetary gear speed reducer, a driving wheel set and a robot driving module. The multi-point meshing composite planetary gear speed reducer is provided with a sun gear as a power input; double planetary gears are uniformly distributed around the sun gear, the double planetary gears are composed of first planetary gears and second planetary gears, the sun gear is meshed with each first planetary gear; there is an intermediate planetary gear between any two adjacent second planetary gears in the circumferential direction, each intermediate planetary gear is meshed with the adjacent two second planetary gears; an inner ring gear is arranged on the casing of the speed reducer, and the inner ring gear is meshed with the intermediate planetary gears. The existing planetary speed reducer has defects in torque transmission capacity and load bearing capacity, the present application adopts the combined structure of double planetary gears and intermediate planetary gears, so that the intermediate planetary gears form a multi-point meshing relationship in the transmission process, thereby uniformly dispersing the load and improving the torque transmission capacity and load bearing capacity of the speed reducer.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, specifically to a multi-point meshing composite planetary gear reducer, a drive wheel set, and a robot drive module. Background Technology

[0002] Planetary reducers have become a core component in fields such as robot joint drives due to their numerous advantages. Currently, planetary reducers used in robot joints are mainly divided into three transmission types: NGW, NW, and 3K. The NGW transmission type is the most widely used, with a single-stage transmission ratio ranging from 3 to 9. Its advantages include relatively simple manufacturing processes, facilitating mass production, but its disadvantage lies in the larger axial dimension when using multi-stage transmissions. The NW transmission type can achieve a transmission ratio of up to 17, but its manufacturing process is more complex and requires higher machining precision. The 3K transmission type has a larger transmission ratio range, but its efficiency is relatively low. It generally has double internal gears, making its structure the most complex and placing higher demands on design and manufacturing.

[0003] While planetary gear reducers play a crucial role in humanoid robot joints, various transmission types of planetary gear reducers still face several pressing issues. Regarding accuracy and transmission ratio, the single-stage transmission ratio range of planetary gear reducers is relatively small. To meet the high reduction ratio requirements of humanoid robots, multi-stage structures are typically required. This not only increases the complexity of the structural design but also poses a significant challenge to the precise arrangement of gears within limited space. In terms of torque and load capacity, the torque transmission capacity of planetary gear reducers still has room for improvement and struggles to meet the needs of humanoid robots in high-load scenarios, such as lifting heavy objects or climbing stairs. This limitation in load capacity is a key factor restricting its further development. Furthermore, the high manufacturing cost of planetary gear reducers hinders their development and market competitiveness in the robotics industry. Summary of the Invention

[0004] To address the shortcomings of existing planetary gear reducers, this invention provides a multi-point meshing composite planetary gear reducer. Through the combined design of double planetary gears and intermediate planetary gears, the intermediate planetary gears form a multi-point meshing relationship during transmission, which allows the load to be evenly distributed, effectively improving the load-bearing capacity of the reducer and significantly enhancing torque transmission capability and system reliability.

[0005] The technical solution provided by this invention is as follows: a multi-point meshing compound planetary gear reducer, comprising an input shaft, a sun gear, a double planetary gear set, an intermediate planetary gear set, a housing, a first planetary carrier, and a second planetary carrier; the sun gear is fixedly disposed at the end of the input shaft; at least three double planetary gear sets are provided, the double planetary gear sets are evenly arranged around the sun gear, each double planetary gear set includes a first planetary gear set and a second planetary gear set coaxially and fixed to each other, each first planetary gear set meshing with the sun gear; an intermediate planetary gear set exists between any two adjacent second planetary gear sets in the circumferential direction, and each intermediate planetary gear set simultaneously... The sun gear meshes with two adjacent second planetary gears; an internal gear ring is provided on the inner side of the housing, the sun gear, the double planetary gear, and the intermediate planetary gear are all located on the inner side of the housing, and each of the intermediate planetary gears meshes with the internal gear ring; the first planetary carrier and the second planetary carrier are respectively located on both sides of the housing, and the input shaft passes through the first planetary carrier or the second planetary carrier; a plurality of pins are fixedly provided between the first planetary carrier and the second planetary carrier, and the double planetary gear and the intermediate planetary gear are rotatably mounted on the corresponding pins; when the first planetary carrier or the second planetary carrier is used as the output, the transmission ratio is: i = 1 - (z p1 *z g ) / (z s *z p2 When the housing is used as the output, the transmission ratio is: i = z p1 *z g / (z s *z p2 ); where z s The number of teeth on the sun gear; z p1 z is the number of teeth on the first planetary gear; p2 z is the number of teeth on the second planetary gear; g This represents the number of teeth on the internal gear ring.

[0006] Optionally, the number of teeth of the sun gear, the first planet gear, the second planet gear, the intermediate planet gear, and the internal gear ring satisfies: z s +z p1 =z p2 +z m =z g -z m Among them, z m The number of teeth on the intermediate planetary gear.

[0007] Optionally, three of each of the double planetary gears and the intermediate planetary gears are provided. The sun gear has a rotation center Q1, the double planetary gears have a rotation center Q2, and the intermediate planetary gears have a rotation center Q3. For any gear set consisting of one of the double planetary gears, one of the intermediate planetary gears meshing with it, and the sun gear, the lines connecting Q1, Q2, and Q3 form an equilateral triangle.

[0008] Optionally, the number of teeth of the sun gear, the first planet gear, the second planet gear, the intermediate planet gear, and the internal gear ring are all integer multiples of 3.

[0009] Optionally, needle roller bearings are provided between the double planetary gear and the pin, and between the intermediate planetary gear and the pin.

[0010] Optionally, a first shim is provided between each end of the double planetary gear and the first planetary carrier and the second planetary carrier, and the first shim located between the double planetary gear and the first planetary carrier is also located between the intermediate planetary gear and the first planetary carrier; the first shim is provided with a plurality of first clearance holes, and the pin passes through the first clearance holes; a second shim is provided between the first planetary gear and the intermediate planetary gear, and the second shim is provided with second clearance holes and third clearance holes spaced apart along the circumferential direction, the pin passes through the second clearance hole, and the second planetary gear passes through the third clearance hole.

[0011] Optionally, it further includes a coupling sleeve, a screw, a first bearing, a second bearing, and a third bearing; the pin is fixedly connected to the first planetary carrier and the second planetary carrier by the screw, and the coupling sleeve is fixedly connected to one end of the input shaft; the first bearing is located between the coupling sleeve and the first planetary carrier; the second bearing is located between the input shaft and the second planetary carrier; the third bearing is located between the housing and the first planetary carrier, and also between the housing and the second planetary carrier.

[0012] Optionally, a nano-coating is provided on the tooth surfaces of the sun gear, the double planetary gear, the intermediate planetary gear, and the internal gear ring.

[0013] A drive wheel assembly includes the aforementioned multi-point meshing compound planetary gear reducer, and further includes a motor and a tire body. The motor is fixedly connected to the first planetary carrier, the output shaft of the motor is fixedly connected to the input shaft, and the tire body covers the outer side of the housing.

[0014] A robot drive module includes the aforementioned multi-point meshing composite planetary gear reducer, and further includes a housing, a rotor, a magnet, and a stator coil; the housing is fixedly connected to the housing, and a gap is formed between the housing and the housing; the stator coil is located within the gap and is fixedly connected to the housing; the center of the rotor is fixedly connected to the input shaft; the magnet is fixedly disposed on the circumferential inner wall of the rotor, and the magnet is correspondingly disposed with respect to the stator coil.

[0015] Compared with the prior art, the technical solution provided by this invention has the following advantages: In view of the shortcomings of existing planetary reducers, this invention, through the combined design of double planetary gears and intermediate planetary gears, enables the intermediate planetary gears to form a multi-point meshing relationship during transmission, so that the load can be evenly distributed, effectively improving the load-bearing capacity of the reducer, and significantly improving the torque transmission capacity and system reliability.

[0016] Compared to traditional planetary reducers, this invention achieves direct meshing transmission between two sets of planetary gears: a double-planetary gear set and an intermediate planetary gear set. This results in a more compact structure, and the direct meshing transmission between these planetary gear sets enables a wider range of gear ratio combinations, thus expanding the transmission ratio range.

[0017] Compared to traditional planetary reducers, achieving a specific transmission ratio may require designing a more complex composite gear train structure or a multi-stage mechanism. However, the single reducer of this invention can achieve a wider range of transmission ratios, thus giving it superior economic efficiency. Attached Figure Description

[0018] Figure 1 This is a cross-sectional schematic diagram of the multi-point meshing composite planetary gear reducer proposed in an embodiment of the present invention.

[0019] Figure 2 This is an exploded schematic diagram of the multi-point meshing composite planetary gear reducer proposed in an embodiment of the present invention.

[0020] Figure 3 This is one of the schematic diagrams of the multi-point meshing composite planetary gear reducer proposed in the embodiments of the present invention.

[0021] Figure 4 This is the second schematic diagram of the principle of the multi-point meshing composite planetary gear reducer proposed in the embodiment of the present invention.

[0022] Figure 5 This is the third schematic diagram of the principle of the multi-point meshing composite planetary gear reducer proposed in the embodiments of the present invention.

[0023] Figure 6 This is an explosion diagram of the double planetary gear proposed in an embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram illustrating the engagement of the double planetary gears proposed in an embodiment of the present invention.

[0025] Figure 8 This is a schematic diagram of the drive wheel assembly proposed in an embodiment of the present invention.

[0026] Figure 9 This is a schematic diagram of the robot drive module proposed in an embodiment of the present invention. Detailed Implementation

[0027] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0028] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "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 the invention and simplifying the description, not 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 the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this invention.

[0029] Example 1

[0030] Combined with appendix Figure 1 and attached Figure 2This embodiment proposes a multi-point meshing composite planetary gear reducer, including an input shaft 100, a sun gear 101, a double planetary gear 102, an intermediate planetary gear 104, a housing 105, a first planetary carrier 106, and a second planetary carrier 107.

[0031] The sun gear 101 is fixedly mounted at the end of the input shaft 100. At least three double planetary gears 102 are provided, typically three to five, with the specific number adjustable according to actual needs; three are used as an example in this embodiment. The three double planetary gears 102 are evenly arranged around the sun gear 101. Each double planetary gear 102 includes a first planetary gear 1021 and a second planetary gear 1022 coaxially arranged and fixed to each other. Each first planetary gear 1021 meshes with the sun gear 101.

[0032] Furthermore, an intermediate planetary gear 104 exists between any two adjacent second planetary gears 1022 in the circumferential direction, and each intermediate planetary gear 104 simultaneously meshes with two adjacent second planetary gears 1022; an internal gear ring 1051 is provided on the inner side of the housing 105, and the sun gear 101, the double planetary gears 102, and the intermediate planetary gears 104 are all located on the inner side of the housing 105, with each intermediate planetary gear 104 meshing with the internal gear ring 1051. Since there are three double planetary gears 102 in this embodiment, there are correspondingly three intermediate planetary gears 104. It is understood that in other embodiments, there may be more than three intermediate planetary gears 104 depending on the configuration of the double planetary gears 102 or the overall reducer.

[0033] The first planetary carrier 106 and the second planetary carrier 107 are located on both sides of the housing 105, and the input shaft 100 passes through the first planetary carrier 106 or the second planetary carrier 107. A number of pins 108 are fixedly arranged between the first planetary carrier 106 and the second planetary carrier 107, and the double planetary gear 102 and the intermediate planetary gear 104 are rotatably arranged on the corresponding pins 108.

[0034] In addition, the multi-point meshing compound planetary gear reducer also includes structures such as a coupling sleeve 109, a screw 112, a first bearing 113, a second bearing 114, and a third bearing 115. The pin 108 is preferably fixedly connected to the first planet carrier 106 and the second planet carrier 107 by an interference fit, meaning the pin 108 will not rotate, thus avoiding any gap between the pin 108 and the first and second planet carriers 106 and 107, which would affect the effective meshing of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104, and the internal gear ring 1051. Furthermore, the pin 108 can be fixedly connected to the first planet carrier 106 and the second planet carrier 107 by a screw 112.

[0035] The coupling sleeve 109 is fixedly connected to one end of the input shaft 100, and is used to connect to the output shaft of an external power mechanism. A first bearing 113 is located between the coupling sleeve 109 and the first planetary carrier 106, a second bearing 114 is located between the input shaft 100 and the second planetary carrier 107, and a third bearing 115 is located between the housing 105 and the first planetary carrier 106, and also between the housing 105 and the second planetary carrier 107. The arrangement of the first bearing 113, the second bearing 114, and the third bearing 115 ensures the smooth movement of each rotating component.

[0036] Appendix Figure 3 To be continued Figure 5 This is a schematic diagram illustrating the meshing principle of this embodiment. The basic working principle of the multi-point meshing composite planetary gear reducer in this embodiment is as follows: The input shaft 100 is connected to and rotates with an external power device, driving the sun gear 101 to rotate. The sun gear 101 serves as the power input end of the reducer. Each double planetary gear 102 consists of a first planetary gear 1021 and a second planetary gear 1022, which are coaxially fixed. The sun gear 101 meshes with the three first planetary gears 1021, realizing power input. The second planetary gear 1022 rotates synchronously with the first planetary gears 1021. The second planetary gear 1022 meshes with the intermediate planetary gear 104, which in turn meshes with the internal gear ring 1051, achieving power transmission.

[0037] In this embodiment, the speed reduction and torque increase effect of the reducer is achieved through the continuous meshing of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104, and the internal gear ring 1051 on the housing 105.

[0038] The reducer in this embodiment has two output forms. One form is to keep the housing 105 stationary while the double planetary gear 102 and the intermediate planetary gear 104 perform planetary motion, and output is achieved through the circumferential rotation of the first planetary carrier 106 or the second planetary carrier 107. The other form is to keep the first planetary carrier 106 or the second planetary carrier 107 stationary while output is achieved through the circumferential rotation of the housing 105.

[0039] Specifically, when the first planetary carrier 106 or the second planetary carrier 107 is used as the output, its transmission ratio is: i = 1 - z p1 *z g / (z s *z p2 When housing 105 is used as the output, its transmission ratio is: i = z p1 *z g / (z s *z p2 ), where z s The number of teeth on the sun gear 101; z p1 The number of teeth on the first planetary gear 1021; zp2 The number of teeth on the second planetary gear 1022; z g This represents the number of teeth on the internal gear ring 1051.

[0040] Clearly, by adjusting the number of teeth on the sun gear 101, the first planetary gear 1021, the second planetary gear 1022, the intermediate planetary gear 104, and the internal gear ring 1051, the transmission ratio can be flexibly changed to meet the needs of different application scenarios. For example, by adjusting different numbers of teeth, a specific transmission ratio can be achieved for robot joints, thereby meeting the requirements of different robot joints. Therefore, the reducer of this embodiment will have broader application prospects in robot joint driving.

[0041] In this embodiment, three intermediate planetary gears 104 are evenly distributed among the second planetary gears 1022. Each intermediate planetary gear 104 simultaneously meshes with the adjacent second planetary gear 1022, and each intermediate planetary gear 104 also simultaneously meshes with the internal gear ring 1051. This meshing configuration directly realizes the meshing transmission between the two sets of planetary gears, the double planetary gears 102 and the intermediate planetary gears 104. This allows the intermediate planetary gears 104 to form a multi-point meshing relationship during transmission, enabling the load to be evenly distributed and effectively improving the load-bearing capacity of the reducer. In other words, it also achieves the effect of force dispersion transmission, effectively solving the load sharing problem of traditional planetary gear systems in multi-planetary gear applications, and significantly improving torque transmission capability and system reliability. Therefore, the multi-point meshing composite planetary gear reducer of this embodiment can meet the needs of robots in high-load scenarios.

[0042] Compared with traditional planetary reducers, this embodiment utilizes the direct meshing between two sets of planetary gears, namely the double planetary gear 102 and the intermediate planetary gear 104, to achieve continuous transmission between the sun gear 101 and the internal gear ring 1051, resulting in a more compact structure.

[0043] In traditional reducers, there is always a certain error between any meshing gears. This error affects the effectiveness of meshing, thus affecting the stability of transmission and ultimately leading to a decrease in the overall operational stability of the reducer. However, in the multi-point meshing compound planetary gear reducer of this embodiment, although meshing error still exists when any intermediate planetary gear 104 meshes with two adjacent second planetary gears 1022 simultaneously, since the error is randomly generated, when there is an error between the intermediate planetary gear 104 and one second planetary gear 1022 at a certain meshing position, the meshing between the intermediate planetary gear 104 and the other second planetary gear 1022 may not have an error (which can be considered to be within the allowable range). In this case, the intermediate planetary gear 104 can still transmit normally. That is, from an overall perspective, the impact of meshing error is "weakened". In other words, the probability that the meshing errors of any intermediate planetary gear 104 and the two second planetary gears 1022 at two points simultaneously exceed the allowable range is very small. As long as one of the second planetary gears 1022 meshes normally with the intermediate planetary gear 104, the error will not affect the normal operation of the reducer. Therefore, based on the transmission form of the intermediate planetary gear 104 and the double planetary gear 102, the reducer in this embodiment also has error averaging characteristics, that is, the reducer in this embodiment has higher transmission accuracy.

[0044] Based on the meshing transmission form of this embodiment and the transmission ratio calculation method described above, it can be seen that the multi-point meshing compound planetary gear reducer of this embodiment can achieve a wider range of transmission ratios within a more compact volume, and achieve stronger load capacity within a limited volume. A specific example is provided here, where the number of teeth z of the sun gear 101... s The number of teeth z of the first planetary gear 1021 is 12. p1 The number of teeth z of the second planetary gear 1022 is 57. p2 The number of teeth z of the intermediate planetary gear 104 is 18. m The number of teeth z of the internal gear ring 1051 is 51. g When the gear ratio is 120 and the housing is 105 as the output, the gear ratio of the reducer is 31.67.

[0045] To achieve a transmission ratio close to that of traditional planetary reducers, a more complex composite gear train structure or multi-stage mechanism might be required. For example, the single-stage transmission ratio of NGW or NW type reducers is relatively small, necessitating multi-stage series connection. This inevitably increases their size, and the increased complexity after series connection reduces their stability and transmission efficiency. In contrast, the single reducer of this invention can achieve a wider transmission ratio range and is clearly more economical. Similarly, while a single-stage 3K type reducer can achieve a transmission ratio close to that of the example above, its structure—two internal gears and a planetary gear set with a corresponding planet carrier—significantly results in a relatively large size and lower efficiency. It cannot achieve the compact structure and large transmission ratio of the reducer in this example. Therefore, the reducer of this embodiment can meet the needs of robots under high load conditions and has broad application prospects.

[0046] It is easy to understand that, apart from this embodiment, when there are three or more of the double planetary gears 102 and the intermediate planetary gears 104, as long as the multi-point meshing of the double planetary gears 102 and the intermediate planetary gears 104 exists, the above-mentioned load distribution effect, compactness advantage, and error elimination characteristics will still exist.

[0047] In a further embodiment, the number of teeth of the sun gear 101, the first planet gear 1021, the second planet gear 1022, the intermediate planet gear 104, and the internal gear ring 1051 satisfies: z s +z p1 =z p2 +z m =z g -z m This implementation method, by designing the tooth number relationship of the sun gear 101, the first planetary gear 1021, the second planetary gear 1022, the intermediate planetary gear 104, and the internal gear ring 1051, ensures that the internal components of the reducer can maintain an effective and stable meshing state during transmission.

[0048] Specifically, the sum of the number of teeth on the sun gear 101 and the first planet gear 1021 is equal to the sum of the number of teeth on the second planet gear 1022 and the intermediate planet gear 104, and is also equal to the number of teeth on the internal gear ring 1051 minus the number of teeth on the intermediate planet gear 104. This tooth number relationship ensures that the gears mesh correctly during operation, avoids mutual interference between gears, and guarantees the stability of the reducer.

[0049] Furthermore, in order to ensure stable and efficient meshing transmission of the components in the reducer when there are three planetary gears 102 and three intermediate planetary gears 104 respectively, the number of teeth of the sun gear 101, the first planetary gear 1021, the second planetary gear 1022, the intermediate planetary gear 104 and the internal gear ring 1051 is preferably an integer multiple of 3.

[0050] Since this embodiment has three sets of double planetary gears 102 and three sets of intermediate planetary gears 104, there are correspondingly six equally spaced pins 108. The pins 108 are preferably fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 via an interference fit, and further fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 via screws 112. This arrangement ensures a stable connection between the first planetary carrier 106 and the second planetary carrier 107 and the double planetary gears 102 and intermediate planetary gears 104, guaranteeing the stability of the reducer output.

[0051] In this embodiment, the fixed connection is achieved by six equally spaced pins 108 and screws 112, which can effectively prevent the double planetary gear 102 and the intermediate planetary gear 104 from shifting or loosening during operation, thus ensuring the stability of the overall structure of the reducer.

[0052] Furthermore, the fastening connection is achieved through six equally spaced pins 108 and screws 112. This design not only improves the overall rigidity of the reducer but also simplifies the assembly process. In addition, the equally spaced pins 108 and screws 112 ensure more even stress distribution on the first planetary carrier 106 and the second planetary carrier 107, further enhancing the reducer's operational stability and service life.

[0053] Through this design, the reducer in this embodiment can maintain efficient and stable transmission performance in complex working environments, solving problems such as easy planetary gear misalignment and overall structural instability of the reducer in existing technologies. Compared with existing technologies, this reducer has higher structural stability and can better meet the requirements of high precision and high stability in operation.

[0054] And, as attached Figure 3 As shown, in this embodiment, there are three double planetary gears 102 and three intermediate planetary gears 104. The sun gear 101 has a rotation center Q1, the double planetary gears 102 have a rotation center Q2, and the intermediate planetary gears 104 have a rotation center Q3. Therefore, for any gear set consisting of a single double planetary gear 102, a meshing intermediate planetary gear 104, and the sun gear 101, the lines connecting Q1, Q2, and Q3 form an equilateral triangle.

[0055] The rotation center Q2 of the double planetary gear 102 and the rotation center Q3 of the intermediate planetary gear 104 are actually the centers of the corresponding pins 108 in the reducer. The lines connecting Q1, Q2 and Q3 form an equilateral triangle. This means that the lines connecting the centers of two adjacent pins 108 with the geometric center of the first planetary carrier 106 (or the second planetary carrier 107) form an equilateral triangle layout. That is, the included angle formed by the lines connecting the centers of any two adjacent pins 108 with the center of the first planetary carrier 106 (or the second planetary carrier 107) is 60°. This layout can ensure a compact structure and smooth transmission.

[0056] Understandably, from an overall perspective, each pin 108 conforms to this equilateral triangle layout design. This design ensures that the planetary carrier remains stable during rotation, avoiding eccentricity problems caused by uneven load distribution. It effectively reduces vibration and noise caused by uneven loads, thereby improving the service life and reliability of the reducer and helping it maintain balance and stability during operation. Furthermore, the equilateral triangle layout allows the first planetary carrier 106 (or the second planetary carrier 107) to better distribute stress when subjected to external impact loads, improving the overall structural rigidity and strength, and enhancing reliability.

[0057] In this embodiment, the second planetary gear 1022 is inserted into the first planetary gear 1021 to form a double planetary gear 102. In some embodiments, the second planetary gear 1022 has an optical axis segment, which is interference-fitted with the central shaft hole of the first planetary gear 1021 to complete the assembly of the double planetary gear 102.

[0058] Combined with appendix Figure 6 In a preferred embodiment, an inner ring gear groove 210 is provided at the center of the first planetary gear 1021, and a plug-in section 220 is fixedly provided on the second planetary gear 1022. An external gear 221 is fixedly provided on the outer periphery of the plug-in section 220, and the external gear 221 cooperates with the inner ring gear groove 210. This embodiment can ensure a stable connection between the first planetary gear 1021 and the second planetary gear 1022.

[0059] The diameter of the insertion section 220 is generally equal to the diameter of the root circle of the second planetary gear 1022. The external gear 221 on the insertion section 220 is an extension of the teeth on the second planetary gear 1022, but the addendum of the external gear 221 on the insertion section 220 should preferably be lower than the addendum of the second planetary gear 1022. Correspondingly, the shape of the inner ring gear groove 210 also needs to be adjusted to match the external gear 221. When the external gear 221 and the inner ring gear groove 210 are engaged, due to the contact at multiple points, the tooth profiles on the external gear 221 and the inner ring gear groove 210 can play a role in dispersing stress, thereby ensuring the stable transmission of torque or load between the first planetary gear 1021 and the second planetary gear 1022, and improving the overall reliability of the double planetary gear 102.

[0060] It is important to note that the layout of the external gear 221 and the inner ring gear groove 210 between each of the double planetary gears 102 should be completely identical to strictly ensure the tooth phase requirements and guarantee the precise meshing of each double planetary gear 102 with the input sun gear 101 and the intermediate planetary gear 104. For example, in the attached... Figure 7 In one embodiment shown, the first planetary gear 1021 and the second planetary gear 1022 form a toothed design, that is, the center lines of one tooth or tooth groove on the external gear 221 of the insertion section 220 and the first planetary gear 1021 coincide on the same radial straight line.

[0061] In other preferred embodiments, a nano-coating is provided on the tooth surfaces of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104, and the internal gear ring 1051. By applying a nano-coating to the tooth surfaces of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104, and the internal gear, a nano-level protective film is formed on the tooth surfaces of each component. This significantly improves their surface hardness and wear resistance, ensuring the stability and reliability of the reducer under high load and long-term operating conditions, thereby extending the service life of the reducer.

[0062] Specifically, nano-coating treatment can be achieved through methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD). These methods can uniformly deposit a nano-coating with high hardness and high wear resistance on the gear surface. Nano-coating materials can be selected from titanium nitride (TiN) and tungsten carbide (WC), which have excellent mechanical properties and chemical stability, and can effectively improve the hardness and wear resistance of the gear surface.

[0063] Furthermore, the thickness of the nano-coating can be adjusted according to the working environment and load of the gear, generally ranging from a few micrometers to tens of micrometers, to ensure that the wear resistance is maximized without affecting the gear's precision.

[0064] Through the design of the nano-coating, the reducer in this embodiment achieves significant improvements in wear resistance and service life. This not only reduces the frequency of gear maintenance and replacement, lowering operating costs, but also ensures stable operation of the reducer under various complex working conditions. Compared with existing technologies, the technical solution of this application has obvious advantages in improving gear wear resistance and extending service life.

[0065] In some embodiments, needle roller bearings 103 are provided between the double planetary gear 102 and the pin 108, and between the intermediate planetary gear 104 and the pin 108. In this embodiment, the double planetary gear 102 and the intermediate planetary gear 104 are rotatably connected to the pin 108. By providing needle roller bearings 103, friction can be effectively reduced and transmission efficiency improved. This design not only ensures the smooth rotation of the double planetary gear 102 and the intermediate planetary gear 104, but also improves the overall stability of the reducer.

[0066] Specifically, the use of needle roller bearing 103 reduces frictional losses between the double planetary gear 102 and the intermediate planetary gear 104 during transmission, thereby improving transmission efficiency. Simultaneously, the structure of needle roller bearing 103 ensures that the double planetary gear 102 and the intermediate planetary gear 104 maintain stable operation under high load conditions, further enhancing the stability and service life of the reducer. It is easy to see that high-strength needle roller bearing 103 can be preferred to adapt to more demanding working environments and load requirements.

[0067] In other embodiments, first gaskets 110 are provided between both ends of the double planetary gear 102 and the first planetary carrier 106 and the second planetary carrier 107, and the first gasket 110 located between the double planetary gear 102 and the first planetary carrier 106 is also located between the intermediate planetary gear 104 and the first planetary carrier 106; the first gasket 110 is provided with a plurality of first clearance holes 1101, and the pin 108 passes through the first clearance holes 1101. A second gasket 111 is provided between the first planetary gear 1021 and the intermediate planetary gear 104, and the second gasket 111 is provided with second clearance holes 1111 and third clearance holes 1112 spaced apart along the circumferential direction, the pin 108 passes through the second clearance hole 1111, and the second planetary gear 1022 passes through the third clearance hole 1112. In these embodiments, the design of the first shim 110 and the second shim 111 can respectively fill the gaps between the double planetary gear 102, the intermediate planetary gear 104, the first planetary carrier 106, and the second planetary carrier 107, and simultaneously limit the movement of the double planetary gear 102 and the intermediate planetary gear 104, i.e., retain them. Therefore, it can be ensured that the double planetary gear 102 and the intermediate planetary gear 104 maintain stable operation under high load conditions, further improving the stability and service life of the reducer.

[0068] The first clearance hole 1101 on the first shim 110, and the second clearance hole 1111 and the third clearance hole 1112 on the second shim 111 are designed to avoid interference with the corresponding pin 108 or the second planetary gear 1022, which is also to ensure the effective operation of the reducer.

[0069] In traditional gear reducers, shims are also placed on the end faces of planetary gears and other gears. However, the shims in traditional reducers are generally circular shims coaxial with the planetary gears and other gears. When the planetary gears and other gears rotate, the shims may remain stationary or rotate with the gears. The function of the shims is to prevent direct friction between the gears and the planetary carrier, which would cause wear on the end faces of the planetary carrier. However, if the shims rotate with the gears, friction will occur between the shims and the planetary carrier, leading to wear on the planetary carrier.

[0070] In this embodiment, the first gasket 110 is not circular. The first gasket 110 is limited by the first clearance hole 1101 and the pin 108 and cannot rotate on its own, thereby avoiding relative rotation and friction between the first gasket 110 and the first planetary carrier 106 or the second planetary carrier 107, and thus effectively avoiding wear on the first planetary carrier 106 and the second planetary carrier 107.

[0071] Example 2

[0072] Combined with appendix Figure 8 This embodiment proposes a drive wheel assembly, including the multi-point meshing composite planetary gear reducer described in Embodiment 1, and further including a motor 301 and a tire body 302. The motor 301 is fixedly connected to the first planetary carrier 106, and the output shaft of the motor 301 is fixedly connected to the input shaft 100. The tire body 302 covers the outer side of the housing 105. The motor 301 is preferably a servo motor 301, and the tire body 302 is preferably made of polyurethane rubber. In other embodiments, the tire body 302 can also be selected as other types of tires.

[0073] The drive wheel assembly of this embodiment can be used as an AGV drive wheel assembly in automated logistics equipment. Specifically, the polyurethane rubber wheels have good wear resistance and shock absorption performance, which can effectively extend the service life of the drive wheel assembly and improve the stability of equipment operation. The connection of the servo motor 301 enables the drive wheel assembly to achieve precise speed and position control, further improving the automation level and work efficiency of the equipment.

[0074] For the drive wheel set in this embodiment, the various advantages of the multi-point meshing compound planetary gear reducer described in Embodiment 1 can be fully utilized to ensure that the AGV drive wheel set and other devices have excellent performance, thereby improving the performance and market competitiveness of automated logistics equipment or other application equipment.

[0075] Example 3

[0076] Combined with appendix Figure 9 This embodiment proposes a robot drive module, including the multi-point meshing composite planetary gear reducer described in Embodiment 1, and further including a housing 401, a rotor 402, a magnet 403, and a stator coil 404. The housing 401 is fixedly connected to the housing 105, forming a gap between the housing 401 and the housing 105. The stator coil 404 is located within the gap and fixedly connected to the housing 105. The center of the rotor 402 is fixedly connected to the input shaft 100. The magnet 403 is fixedly disposed on the circumferential inner wall of the rotor 402, and the magnet 403 is correspondingly disposed to the stator coil 404.

[0077] In this embodiment, the outer shell 401, rotor 402, magnet 403 and stator coil 404 actually constitute a frameless motor 301 structure. The frameless motor 301 with the reducer embedded in the outer rotor 402 further constitutes a robot drive module, which effectively ensures the compactness of the overall structure. This robot drive module can be used as a robot joint module, which can effectively improve the transmission efficiency and stability of the robot joint.

[0078] Clearly, the robot drive module in this embodiment achieves efficient power transmission and significantly improves torque transmission capability through the multi-point meshing composite planetary gear structure of Embodiment 1, making it suitable for precise control of robot joints and high-load operation requirements.

[0079] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A multi-point engagement compound planetary gear reducer characterized by, It includes an input shaft (100), a sun gear (101), a double planetary gear set (102), an intermediate planetary gear set (104), a housing (105), a first planetary carrier (106), and a second planetary carrier (107); The sun gear (101) is fixedly mounted on the end of the input shaft (100); At least three double planetary gears (102) are provided. The double planetary gears (102) are evenly arranged around the sun gear (101). Each double planetary gear (102) includes a first planetary gear (1021) and a second planetary gear (1022) that are coaxially arranged and fixed to each other. The first planetary gear (1021) meshes with the sun gear (101). There is an intermediate planetary gear (104) between any two adjacent second planetary gears (1022) in the circumferential direction, and each intermediate planetary gear (104) simultaneously meshes with the two adjacent second planetary gears (1022); An internal gear ring (1051) is provided on the inner side of the housing (105). The sun gear (101), the double planetary gear (102) and the intermediate planetary gear (104) are all located on the inner side of the housing (105). Each of the intermediate planetary gears (104) meshes with the internal gear ring (1051). The first planetary carrier (106) and the second planetary carrier (107) are located on both sides of the housing (105), and the input shaft (100) passes through the first planetary carrier (106) or the second planetary carrier (107); a plurality of pins (108) are fixedly arranged between the first planetary carrier (106) and the second planetary carrier (107), and the double planetary gear (102) and the intermediate planetary gear (104) are rotatably arranged on the corresponding pins (108); When the first planetary carrier (106) or the second planetary carrier (107) is used as the output, the transmission ratio is: i = 1 - (z p1 *z g ) / (z s *z p2 When the housing (105) is used as the output, the transmission ratio is: i = z p1 *z g / (z s *z p2 ); where z s The number of teeth on the sun gear (101); z p1 z is the number of teeth of the first planetary gear (1021); p2 The number of teeth on the second planetary gear (1022); z g The number of teeth on the internal gear ring (1051) is given.

2. A multi-point engagement compound planetary gear reducer according to claim 1, characterized in that, The number of teeth of the sun gear (101), the first planet gear (1021), the second planet gear (1022), the intermediate planet gear (104), and the internal gear ring (1051) satisfies: z s +z p1 =z p2 +z m =z g -z m Among them, z m The number of teeth of the intermediate planetary gear (104).

3. A multi-point engagement compound planetary gear reducer according to claim 1, wherein The double planetary gear (102) and the intermediate planetary gear (104) are each provided in threes. The sun gear (101) has a rotation center Q1, the double planetary gear (102) has a rotation center Q2, and the intermediate planetary gear (104) has a rotation center Q3. For any gear set consisting of a double planetary gear (102), an intermediate planetary gear (104) meshing with it, and a sun gear (101), the lines connecting Q1, Q2, and Q3 form an equilateral triangle.

4. A multi-point engagement compound planetary gear reducer according to claim 1 or 3, characterized in that, The number of teeth of the sun gear (101), the first planet gear (1021), the second planet gear (1022), the intermediate planet gear (104), and the internal gear ring (1051) are all multiples of 3.

5. A multi-point engagement compound planetary gear reducer according to claim 1, wherein Needle roller bearings (103) are provided between the double planetary gear (102) and the pin (108), and between the intermediate planetary gear (104) and the pin (108).

6. A multi-point engagement compound planetary gear reducer according to claim 1, wherein Both ends of the double planetary gear (102) are provided with first gaskets (110) between the first planet carrier (106) and the second planet carrier (107), and the first gasket (110) located between the double planetary gear (102) and the first planet carrier (106) is also located between the intermediate planetary gear (104) and the first planet carrier (106); the first gasket (110) is provided with a plurality of first clearance holes (1101), and the pin (108) passes through the first clearance holes (1101); A second washer (111) is provided between the first planetary gear (1021) and the intermediate planetary gear (104). The second washer (111) is provided with a second clearance hole (1111) and a third clearance hole (1112) at intervals along the circumferential direction. The pin (108) passes through the second clearance hole (1111) and the second planetary gear (1022) passes through the third clearance hole (1112).

7. A multi-point engagement compound planetary gear reducer according to claim 1, wherein It also includes a coupling sleeve (109), a screw (112), a first bearing (113), a second bearing (114), and a third bearing (115); The pin (108) is fixedly connected to the first planetary carrier (106) and the second planetary carrier (107) by the screw (112), and the coupling sleeve (109) is fixedly connected to one end of the input shaft (100); the first bearing (113) is located between the coupling sleeve (109) and the first planetary carrier (106); the second bearing (114) is located between the input shaft (100) and the second planetary carrier (107); the third bearing (115) is located between the housing (105) and the first planetary carrier (106), and between the housing (105) and the second planetary carrier (107).

8. A multi-point engagement compound planetary gear reducer according to claim 1, wherein The sun gear (101), the double planetary gear (102), the intermediate planetary gear (104), and the internal gear ring (1051) are all provided with nano-coatings on their tooth surfaces.

9. A drive wheel set, characterized in that The multi-point meshing compound planetary gear reducer according to any one of claims 1-8 further includes a motor (301) and a tire body (302), wherein the motor (301) is fixedly connected to the first planetary carrier (106), the output shaft of the motor (301) is fixedly connected to the input shaft (100), and the tire body (302) covers the outside of the housing (105).

10. A robot drive module, characterized in that, The multi-point meshing composite planetary gear reducer according to any one of claims 1-8 further includes a housing (401), a rotor (402), a magnet (403), and a stator coil (404); The outer casing (401) is fixedly connected to the housing (105), and a gap is formed between the outer casing (401) and the housing (105). The stator coil (404) is located in the gap and is fixedly connected to the housing (105). The center of the rotor (402) is fixedly connected to the input shaft (100). The magnet (403) is fixedly disposed on the circumferential inner wall of the rotor (402), and the magnet (403) is correspondingly disposed to the stator coil (404).

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