Multi-point meshing compound planetary gear reducer, driving wheel set and robot driving module

Abstract

The invention belongs to the technical field of speed reducers, and particularly relates to a multi-point meshing compound planetary gear speed reducer, a driving wheel set and a robot driving module. Wherein the multi-point meshing compound planetary gear reducer is provided with a sun gear serving as power input; the duplex planet gears are uniformly distributed around the sun gear, the duplex planet gears are composed of first planet gears and second planet gears, and the sun gear is meshed with the first planet gears; an intermediate planet gear exists between any two adjacent second planet gears in the circumferential direction, and each intermediate planet gear is meshed with the two adjacent second planet gears at the same time; an inner gear ring is arranged on a machine shell of the speed reducer, and the inner gear ring is meshed with the intermediate planet wheel. An existing planetary reducer has defects in the torque transmission capacity and the bearing capacity, a combined structure of a duplex planet wheel and an intermediate planet wheel is adopted, the intermediate planet wheel forms a multi-point meshing relation in the transmission process, loads are evenly dispersed, and the torque transmission capacity and the bearing capacity of the reducer are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of speed reducers, and particularly relates to a multi-point meshing composite planetary gear speed reducer, a driving wheel set, and a robot driving module. Background Art

[0002] Planetary speed reducers have become one of the core components in fields such as robot joint drives due to their many advantages. Currently, the planetary speed reducers used in robot joints are mainly divided into three transmission forms: NGW, NW, and 3K. The NGW transmission form is the most widely used, with a single-stage transmission ratio range of 3 to 9. Its advantage is that the manufacturing process is relatively simple and it is convenient for large-scale production, but the defect is that the axial dimension is relatively large during multi-stage transmission. The transmission ratio of the NW transmission form can reach 17, but its manufacturing process is relatively complex and has high requirements for machining accuracy. The 3K transmission form has a relatively large transmission ratio range, but the efficiency is relatively low. Generally, it has double internal gears and the structure is the most complex, posing higher requirements for design and manufacturing.

[0003] Although planetary speed reducers play an important role in humanoid robot joints, the planetary speed reducers of various existing transmission forms still face some problems that need to be solved urgently. In terms of accuracy and transmission ratio, the single-stage transmission ratio range of planetary speed reducers is relatively small. In order to meet the requirements of humanoid robots for large reduction ratios, a multi-stage structure is usually required. This not only increases the complexity of the structural design but also poses a huge challenge to the precise arrangement of gears in a limited space. In terms of torque and load capacity, the torque transmission capacity of planetary speed reducers still has room for improvement and it is difficult to meet the requirements of humanoid robots in some high-load scenarios, such as tasks like carrying heavy objects or climbing stairs. The limitation of its load capacity has become a key factor restricting its further development. In addition, the manufacturing cost of planetary speed reducers is relatively high, restricting the development and market competitiveness of planetary speed reducers used in the robot industry. Summary of the Invention

[0004] Aiming at the deficiencies of existing planetary speed reducers, the present invention provides a multi-point meshing composite planetary gear speed reducer. Through the combined design of a double-connected planetary gear and an intermediate planetary gear, the intermediate planetary gear forms a multi-point meshing relationship during the transmission process, enabling the load to be evenly dispersed, effectively improving the bearing capacity of the speed reducer, and significantly enhancing the torque transmission capacity and system reliability.

[0005] The technical solution provided by the present invention is as follows: a multi-point meshing compound planetary gear reducer, comprising an input shaft, a sun gear, a double planetary gear, an intermediate planetary gear, a housing, a first planetary carrier and a second planetary carrier; the sun gear is fixedly arranged at the end of the input shaft; at least three double planetary gears are provided, and the double planetary gears are evenly arranged around the sun gear. Each double planetary gear includes a first planetary gear and a second planetary gear which are coaxially arranged and fixedly connected to each other, and each first planetary gear meshes with the sun gear; there is one intermediate planetary gear between any two adjacent second planetary gears in the circumferential direction, and each intermediate planetary gear meshes with the two adjacent second planetary gears at the same time; an internal gear ring is arranged on the inner side of the housing, the sun gear, the double planetary gears and the intermediate planetary gears are all located inside the housing, and each intermediate planetary gear 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 penetrates through the first planetary carrier or the second planetary carrier; a plurality of pin shafts are fixedly arranged between the first planetary carrier and the second planetary carrier, and the double planetary gears and the intermediate planetary gears are all rotatably arranged on the corresponding pin shafts; 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 );wherein, z s is the number of teeth of the sun gear; z p1 is the number of teeth of the first planetary gear; z p2 is the number of teeth of the second planetary gear; z g is the number of teeth of the internal gear ring.

[0006] Optionally, the number of teeth of the sun gear, the first planetary gear, the second planetary gear, the intermediate planetary gear and the internal gear ring satisfies: z s +z p1 =z p2 +z m =z g -z m ;wherein, z m is the number of teeth of the intermediate planetary gear.

[0007] Optionally, three of the double planetary gears and three of the intermediate planetary gears are respectively provided; the sun gear has a rotation center Q1, the double planetary gear has a rotation center Q2, and the intermediate planetary gear has a rotation center Q3; for any gear set composed of one of the double planetary gears, and one of the intermediate planetary gears and the sun gear that mesh with it, the connection lines of Q1, Q2, and Q3 therein form an equilateral triangle.

[0008] Optionally, the number of teeth of the sun gear, the first planetary gear, the second planetary gear, the intermediate planetary 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, first gaskets are provided between both ends of the double planetary gear and the first planetary carrier and the second planetary carrier, and the first gasket located between the double planetary gear and the first planetary carrier is also located between the intermediate planetary gear and the first planetary carrier; a plurality of first avoidance holes are provided on the first gasket, and the pin passes through the first avoidance holes; a second gasket is provided between the first planetary gear and the intermediate planetary gear, and second avoidance holes and third avoidance holes are sequentially arranged at intervals in the circumferential direction on the second gasket, the pin passes through the second avoidance holes, and the second planetary gear passes through the third avoidance holes.

[0011] Optionally, it further includes a coupling sleeve, screws, 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 through the screws, 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 between the housing and the second planetary carrier.

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

[0013] A driving wheel set includes the above - mentioned multi - point meshing composite 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 is coated on the outer side of the housing.

[0014] A robot drive module includes the above-mentioned multi-point meshing compound planetary gear reducer, and also includes a housing, a rotor, a magnet, and a stator coil; the housing is fixedly connected to the machine housing, a gap is formed between the housing and the machine housing, the stator coil is located in the gap and fixedly connected to the machine housing, the center of the rotor is fixedly connected to the input shaft, the magnet is fixedly arranged on the circumferential inner wall of the rotor, and the magnet is arranged corresponding to the stator coil.

[0015] Adopting the technical solution provided by the present invention, compared with the prior art, it has the following beneficial effects: aiming at the deficiencies of the existing planetary reducer, through the combined design of the double planetary gear and the intermediate planetary gear in the present invention, a multi-point meshing relationship is formed during the transmission of the intermediate planetary gear, so that the load is evenly dispersed, effectively improving the bearing capacity of the reducer, and significantly improving the torque transmission capacity and system reliability.

[0016] And compared with the traditional planetary reducer, the present invention realizes the direct meshing transmission between the two sets of planetary gears of the double planetary gear and the intermediate planetary gear, making the structure more compact, and this direct meshing transmission between the planetary gear sets can achieve a richer combination of gear ratios, making the transmission ratio range larger.

[0017] Compared with the traditional planetary reducer, if a specific transmission ratio needs to be achieved, a more complex compound gear train structure or multi-stage mechanism may need to be designed, while a single reducer of the present invention can achieve a larger transmission ratio range, and the present invention thus has better economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional view of the multi-point meshing compound planetary gear reducer proposed in the embodiment of the present invention.

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

[0020] Figure 3 It is one of the schematic diagrams of the principle of the multi-point meshing compound planetary gear reducer proposed in the embodiment of the present invention.

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

[0022] Figure 5 It is a third schematic diagram of the principle of the multi-point meshing compound planetary gear reducer proposed in the embodiment of the present invention.

[0023] Figure 6 It is an exploded schematic view of the double planetary gear proposed in the embodiment of the present invention.

[0024] Figure 7 Schematic diagram of the cooperation of the double planetary gears proposed in the embodiments of the present invention.

[0025] Figure 8 Schematic diagram of the structure of the driving wheel set proposed in the embodiments of the present invention.

[0026] Figure 9 Schematic diagram of the structure of the robot drive module proposed in the embodiments of the present invention. Detailed implementation manners

[0027] To further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings and embodiments.

[0028] The following will further elaborate on the present application in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are merely used to explain the related invention and do not limit the invention. Additionally, it should be noted that for the convenience of description, only the parts related to the invention are shown in the drawings. The terms such as "first" and "second" in the present invention are set for the convenience of describing the technical solution of the present invention and have no specific limiting effect. They are all general references and do not constitute a limiting effect on the technical solution of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. 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 without contradiction or conflict, and all are within the scope of protection required by the present invention.

[0029] Embodiment 1

[0030] Combined with the attached Figure 1 and the attached Figure 2, in this embodiment, a multi-point meshing compound planetary gear reducer is proposed, which includes 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] Among them, the sun gear 101 is fixedly arranged at the end of the input shaft 100. There are at least three double planetary gears 102, generally designed to be three to five, and the specific quantity can be adjusted according to actual requirements. In this embodiment, three are taken as an example. The three double planetary gears 102 are evenly surrounded by the sun gear 101. Each double planetary gear 102 includes a first planetary gear 1021 and a second planetary gear 1022 which are coaxially arranged and fixed to each other. Each first planetary gear 1021 meshes with the sun gear 101.

[0032] And, 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 meshes with the adjacent two second planetary gears 1022 at the same time; an internal gear ring 1051 is arranged 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 intermediate planetary gear 104 meshes with the internal gear ring 1051. Since there are three double planetary gears 102 in this embodiment, three intermediate planetary gears 104 are correspondingly arranged. It can be understood that in other embodiments, the number of intermediate planetary gears 104 can be more than three according to the configuration of the double planetary gear 102 or the overall reducer.

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

[0034] In addition, the multi-point meshing compound planetary gear reducer also includes structural components such as a coupling sleeve 109, screws 112, a first bearing 113, a second bearing 114 and a third bearing 115. The stud pins 108 are preferably fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 by an interference fit method, that is, the stud pins 108 will not rotate, so as to avoid gaps between the stud pins 108 and the first planetary carrier 106 and the second planetary carrier 107, thereby affecting the effective meshing of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104 and the internal gear ring 1051. Further, the stud pins 108 can be fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 by screws 112.

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

[0036] Appendix Figure 3 to Appendix Figure 5 is the meshing principle diagram of this embodiment. For the multi-point meshing compound planetary gear reducer of this embodiment, its basic working principle is as follows: The input shaft 100 is connected to an external power device and rotates, 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 is composed of a first planetary gear 1021 and a second planetary gear 1022, and the two are axially coaxial and fixed. The sun gear 101 meshes with three first planetary gears 1021 to achieve power input. The second planetary gear 1022 rotates synchronously with the first planetary gear 1021, and the second planetary gear 1022 meshes with the intermediate planetary gear 104, and the intermediate planetary gear 104 also meshes with the internal gear ring 1051 at the same time to achieve 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 of this embodiment has two output forms. One form is to ensure that the housing 105 is fixed, and the double planetary gear 102 and the intermediate planetary gear 104 perform planetary motion, and the output is achieved through the circumferential rotation of the first planet carrier 106 or the second planet carrier 107; the other form is to ensure that the first planet carrier 106 or the second planet carrier 107 is fixed, and the output is achieved through the circumferential rotation of the housing 105.

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

[0040] Obviously, by adjusting 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, the transmission ratio can be flexibly changed to meet the requirements of different application scenarios. For example, by adjusting different numbers of teeth, a specific transmission ratio applicable to a robot joint can be achieved, thereby meeting the requirements of different robot joints. Thus, the speed reducer of this embodiment will have a broader application prospect in the drive of robot joints.

[0041] In this embodiment, the three intermediate planet gears 104 are evenly distributed between the second planet gears 1022. Each intermediate planet gear 104 meshes with the adjacent second planet gear 1022 at the same time, and each intermediate planet gear 104 also meshes with the internal gear ring 1051 at the same time. This meshing form directly realizes the meshing transmission between the two sets of planet gears, namely the double planet gear 102 and the intermediate planet gear 104, so that the intermediate planet gear 104 forms a multi-point meshing relationship during the transmission process, enabling the load to be evenly dispersed, effectively improving the load-bearing capacity of the speed reducer. In other words, it also realizes the function of force-dispersed transmission, effectively solving the problem of load sharing in the application of traditional planetary gear systems with multiple planet gears, and significantly improving the torque transmission capacity and system reliability. Thus, the multi-point meshing compound planetary gear speed reducer of this embodiment can meet the requirements of robots in high-load scenarios.

[0042] Compared with the traditional planetary speed reducer, this embodiment realizes the continuous transmission between the sun gear 101 and the internal gear ring 1051 by means of the direct meshing between the two sets of planet gears, namely the double planet gear 102 and the intermediate planet gear 104, making the structure more compact.

[0043] For traditional speed reducers, there are certain errors between any meshing gears. Such errors will affect the effectiveness of meshing, and then affect the stability of transmission, and ultimately lead to a decline in the overall operating stability of the speed reducer. However, for the multi-point meshing compound planetary gear speed reducer of this embodiment, any intermediate planetary gear 104 meshes with two adjacent second planetary gears 1022 at the same time. Although the meshing error still exists, since the error is randomly generated, when there is an error at a certain meshing position between the intermediate planetary gear 104 and one second planetary gear 1022, there may be no error in the meshing between the intermediate planetary gear 104 and the other second planetary gear 1022 (it can be considered that the error is within the allowable range). At this time, the intermediate planetary gear 104 can still transmit power normally. That is, overall, the influence of the meshing error is "weakened". In other words, the probability that the errors of the two meshing positions between any intermediate planetary gear 104 and the two second planetary gears 1022 exceed the allowable range at the same time is very small. As long as one of the second planetary gears 1022 meshes with the intermediate planetary gear 104 normally, the error will not affect the normal operation of the speed reducer. Therefore, based on the transmission form between the intermediate planetary gear 104 and the double planetary gear 102, the speed reducer of this embodiment also has the characteristic of error averaging, that is, the speed reducer of 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 speed reducer of this embodiment can achieve a larger range of transmission ratios within a more compact volume, and has a stronger load capacity under a limited volume. Here is a specific example. When the number of teeth z of the sun gear 101 s is 12, the number of teeth z of the first planetary gear 1021 p1 is 57, the number of teeth z of the second planetary gear 1022 p2 is 18, the number of teeth z of the intermediate planetary gear 104 m is 51, the number of teeth z of the internal gear ring 1051 g is 120, and when the housing 105 is used as the output, the transmission ratio of the speed reducer is 31.67.

[0045] For a traditional planetary reducer, if a transmission ratio close to that of the above example is to be achieved, it may be necessary to design a more complex compound gear train structure or a multi-stage mechanism. For example, the single-stage transmission ratio of an NGW or NW type reducer is relatively small and can only be achieved through multi-stage series connection. Inevitably, its volume will increase, and after series connection, its stability will decrease due to increased complexity, and its transmission efficiency will also inevitably decrease. In contrast, a single reducer of the present invention can achieve a larger transmission ratio range and obviously has better economy. Another example is the 3K type reducer. Even if the transmission ratio of a single-stage 3K type reducer can be close to the above example, since the 3K type reducer has two internal gears and a planetary gear set, and the planetary gear set also corresponds to a planet carrier, this structural form basically determines that the 3K type reducer has a relatively large volume and low efficiency, and cannot have both a compact structure and a large transmission ratio like the reducer of this example. Therefore, the reducer of this embodiment can meet the requirements of a robot under high-load conditions and has a wide range of application prospects.

[0046] It is not difficult to understand that, except for this embodiment, when there are more than three double-link planet gears 102 and intermediate planet gears 104 respectively, as long as the multi-point meshing form of the double-link planet gears 102 and the intermediate planet gears 104 exists, the above-mentioned load dispersion effect, compactness advantage, and error elimination characteristics 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 satisfy: z s +z p1 =z p2 +z m =z g -z m . By designing the tooth number relationship 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, this embodiment ensures that each component inside the reducer can maintain an effective and stable meshing state during the transmission process.

[0048] Specifically, the sum of the number of teeth of the sun gear 101 and the first planet gear 1021 is equal to the sum of the number of teeth of the second planet gear 1022 and the intermediate planet gear 104, and is also equal to the number of teeth of the internal gear ring 1051 minus the number of teeth of the intermediate planet gear 104. The setting of this tooth number relationship enables the correct meshing of each gear during operation, avoids mutual interference between the gears, and ensures the stability of the reducer.

[0049] Moreover, in order to ensure stable and efficient meshing transmission of all components within the speed reducer when three double planetary gears 102 and three intermediate planetary gears 104 are respectively provided, 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 three double planetary gears 102 and three intermediate planetary gears 104 are respectively provided in this embodiment, correspondingly, six stud pins 108 are equally spaced. The stud pins 108 are preferably fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 by an interference fit, and further fixedly connected to the first planetary carrier 106 and the second planetary carrier 107 by screws 112. This setting method enables the first planetary carrier 106 and the second planetary carrier 107 to be firmly connected to the double planetary gears 102 and the intermediate planetary gears 104, ensuring the stability of the speed reducer output.

[0051] In this embodiment, by fixedly connecting with six equally spaced stud pins 108 and screws 112, it can effectively prevent the double planetary gears 102 and the intermediate planetary gears 104 from shifting or loosening during operation, ensuring the stability of the overall structure of the speed reducer.

[0052] Furthermore, by fixedly connecting with six equally spaced stud pins 108 and screws 112, this design can not only improve the overall rigidity of the speed reducer but also simplify the assembly process. In addition, the equally spaced stud pins 108 and screws 112 can make the force on the first planetary carrier 106 and the second planetary carrier 107 more uniform, further improving the working stability and service life of the speed reducer.

[0053] Through this design, the speed reducer of this embodiment can maintain efficient and stable transmission performance in a complex working environment, solving the problems of easy offset of planetary gears and unstable overall structure of the speed reducer existing in the prior art. Compared with the prior art, this speed reducer has higher structural stability and can better meet the working requirements of high precision and high stability.

[0054] And, as shown in the Figure 3 attachment, since three double planetary gears 102 and three intermediate planetary gears 104 are respectively provided in this embodiment, and 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. Then for any gear set composed of one double planetary gear 102, and one intermediate planetary gear 104 and the sun gear 101 meshing with it, the connection lines of Q1, Q2, and Q3 form an equilateral triangle.

[0055] Among them, 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, which actually means that the lines connecting the centers of two adjacent pins 108 and the geometric center of the first planet carrier 106 (or the second planet carrier 107) form an equilateral triangle layout, that is, the angle formed by the lines connecting the centers of any two adjacent pins 108 and the center of the first planet carrier 106 (or the second planet carrier 107) is 60°. This layout can ensure a compact structure and smooth transmission.

[0056] It is understandable that, overall, each pin 108 conforms to the layout design of the equilateral triangle, and this design ensures that the planet carrier can remain stable during rotation, avoiding the eccentricity problem caused by uneven load distribution. It can effectively reduce the vibration and noise caused by uneven load, thereby improving the service life and reliability of the reducer, and is conducive to the balance and stability of the reducer during operation. In addition, the layout of the equilateral triangle can also enable the first planet carrier 106 (or the second planet carrier 107) to better disperse stress when subjected to external impact loads, improve the rigidity and strength of the overall structure, and enhance 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, there is an optical axis section on the second planetary gear 1022, and the optical axis section and the central axis hole of the first planetary gear 1021 are interference fit to complete the assembly of the double planetary gear 102.

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

[0059] Among them, the diameter of the insertion section 220 is generally equal to the root circle diameter 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. However, the addendum height of the external gear 221 on the insertion section 220 should preferably be lower than the addendum height 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 cooperates with the inner ring gear groove 210, 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 should be noted that between each double planetary gear 102, the layout of the external gear 221 and the inner ring gear groove 210 should be exactly the same, so as to strictly ensure the tooth alignment phase requirements and ensure the precise meshing of each double planetary gear 102 with the input sun gear 101 and the intermediate planetary gear 104. For example, in Figure 7 In an embodiment shown in the appendix, the first planetary gear 1021 and the second planetary gear 1022 form a tooth alignment 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 line.

[0061] In other preferred embodiments, nano - coatings are 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 performing nano - coating treatment on the tooth surfaces of the sun gear 101, the double planetary gear 102, the intermediate planetary gear 104, and the internal gear, a nano - scale protective film is formed on the tooth surfaces of each component, which can significantly improve their surface hardness and anti - wear performance, ensure the stability and reliability of the reducer under high - load and long - time operation conditions, and thus extend the service life of the reducer.

[0062] Specifically, the nano - coating treatment can be achieved by 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 as titanium nitride (TiN), tungsten carbide (WC), etc. These materials 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 treatment can be adjusted according to the working environment and load conditions of the gear, generally between a few micrometers and dozens of micrometers, to ensure that without affecting the gear accuracy, its wear - resistant performance is maximally improved.

[0064] Through the design of the nano - coating, the reducer of this embodiment has been significantly improved in terms of wear resistance and service life. This not only reduces the frequency of maintaining and replacing gears, lowers the usage cost, but also ensures the stable operation of the reducer under various complex working conditions. Compared with the prior art, the technical solution of this application has obvious advantages in improving the wear resistance of gears and extending the service life.

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

[0066] Specifically, the use of the needle roller bearings 103 can reduce the frictional losses of the double - row planetary gear 102 and the intermediate planetary gear 104 during the transmission process and improve the transmission efficiency. At the same time, the structure of the needle roller bearings 103 enables the double - row planetary gear 102 and the intermediate planetary gear 104 to still maintain smooth operation under high - load conditions, further enhancing the stability and service life of the reducer. It is not difficult to think that high - strength needle roller bearings 103 can be preferably selected to adapt to more stringent working environments and load requirements.

[0067] In addition, in some other embodiments, first gaskets 110 are provided between both ends of the double - row planetary gear 102 and the first planetary carrier 106 and the second planetary carrier 107, and the first gasket 110 located between the double - row planetary gear 102 and the first planetary carrier 106 is also located between the intermediate planetary gear 104 and the first planetary carrier 106; a number of first avoidance holes 1101 are provided on the first gasket 110, and the pin 108 passes through the first avoidance holes 1101. A second gasket 111 is provided between the first planetary gear 1021 and the intermediate planetary gear 104. Second avoidance holes 1111 and third avoidance holes 1112 are sequentially and circumferentially spaced on the second gasket 111, the pin 108 passes through the second avoidance holes 1111, and the second planetary gear 1022 passes through the third avoidance holes 1112. In these embodiments, through the design of the first gasket 110 and the second gasket 111, the gaps between the double - row planetary gear 102, the intermediate planetary gear 104, the first planetary carrier 106 and the second planetary carrier 107 can be filled respectively, and at the same time, the double - row planetary gear 102 and the intermediate planetary gear 104 can be limited, that is, they can be held. Thus, it can be ensured that the double - row planetary gear 102 and the intermediate planetary gear 104 can still maintain smooth operation under high - load conditions, further enhancing the stability and service life of the reducer.

[0068] Among them, the first avoidance hole 1101 on the first gasket 110, and the second avoidance hole 1111 and the third avoidance hole 1112 on the second gasket 111 are to avoid interference with the corresponding stud 108 or the second planet gear 1022, that is, to ensure the effective operation of the reducer as well.

[0069] In traditional reducers, gaskets are also provided at the end faces of gears such as planet gears. However, the gaskets in traditional reducers are generally circular gaskets coaxially arranged with gears such as planet gears. When gears such as planet gears rotate, the gasket may remain stationary or rotate with the gear. The function of the gasket should be to prevent the gear from directly rubbing against the planet carrier and causing wear on the end face of the planet carrier. However, if the gasket rotates with the gear, friction will be formed between the gasket and the planet carrier, resulting in wear of the planet carrier by the gasket.

[0070] In this embodiment, the first gasket 110 is not circular. The first gasket 110 is limited by the first avoidance hole 1101 and the stud 108 and cannot rotate by itself, thereby avoiding relative rotation and friction between the first gasket 110 and the first planet carrier 106 or the second planet carrier 107, and effectively avoiding wear on the first planet carrier 106 and the second planet carrier 107.

[0071] Embodiment 2

[0072] Combined with the attached Figure 8 In this embodiment, a drive wheel set is proposed, which includes the multi-point meshing compound planetary gear reducer described in Embodiment 1, and also includes a motor 301 and a tire body 302. The motor 301 is fixedly connected to the first planet carrier 106, the output shaft of the motor 301 is fixedly connected to the input shaft 100, and the tire body 302 is coated on the outside of the housing 105. Among them, the motor 301 can preferably be a servo motor 301, and the tire body 302 can preferably be made of a polyurethane rubber wheel. In other embodiments, the tire body 302 can also be selected as other forms of tires.

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

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

[0075] Embodiment 3

[0076] Combined with the attached Figure 9 , this embodiment proposes a robot drive module, which includes the multi-point meshing compound planetary gear reducer described in Embodiment 1, and also includes a housing 401, a rotor 402, a permanent magnet 403, and a stator coil 404. Among them, the housing 401 is fixedly connected to the machine housing 105, a gap is formed between the housing 401 and the machine housing 105, the stator coil 404 is located in the gap and fixedly connected to the machine housing 105, the center of the rotor 402 is fixedly connected to the input shaft 100, the permanent magnet 403 is fixedly arranged on the circumferential inner wall of the rotor 402, and the permanent magnet 403 is arranged corresponding to the stator coil 404.

[0077] In this embodiment, the housing 401, the rotor 402, the permanent magnet 403, and the stator coil 404 actually constitute a structure of a frameless motor 301. Embedding the reducer in the outer rotor 402 frameless motor 301 further constitutes a robot drive module, effectively ensuring 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] Obviously, the robot drive module of this embodiment realizes efficient power transmission through the multi-point meshing compound planetary gear structure of Embodiment 1, and significantly improves the torque transmission capacity, and is suitable for the precise control and high-load operation requirements of robot joints.

[0079] The above schematically describes the present invention and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and design a structural manner and an embodiment similar to this technical solution without creative work without departing from the purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A multi-point meshing composite planetary gear reducer, characterized in that, It includes 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); The sun gear (101) is fixedly arranged at the end of the input shaft (100); At least three double planetary gears (102) are provided. The double planetary gears (102) are evenly surrounded by the sun gear (101). Each double planetary gear (102) includes a first planetary gear (1021) and a second planetary gear (1022) which are coaxially arranged and fixed to each other. The first planetary gears (1021) are all meshed 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) is simultaneously meshed with two adjacent second planetary gears (1022); An internal gear ring (1051) is arranged inside the housing (105). The sun gear (101), the double planetary gears (102) and the intermediate planetary gears (104) are all located inside the housing (105). Each intermediate planetary gear (104) is meshed with the internal gear ring (1051); The first planetary carrier (106) and the second planetary carrier (107) are respectively located on both sides of the housing (105). The input shaft (100) penetrates through the first planetary carrier (106) or the second planetary carrier (107); A number of stud pins (108) are fixedly arranged between the first planetary carrier (106) and the second planetary carrier (107). The double planetary gears (102) and the intermediate planetary gears (104) are all rotatably arranged on the corresponding stud pins (108); When the first planet carrier (106) or the second planet 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 is the number of teeth of the sun gear (101); z p1 is the number of teeth of the first planet gear (1021); z p2 is the number of teeth of the second planet gear (1022); z g is the number of teeth of the internal gear ring (1051).

2. The multi-point meshing compound planetary gear reducer according to claim 1, wherein, 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 ; where z m is the number of teeth of the intermediate planet gear (104).

3. A multi-point meshing compound planetary gear reducer according to claim 1, characterized in that, There are three double planetary gears (102) and three intermediate planetary gears (104) respectively. 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 composed of one double planetary gear (102), and an intermediate planetary gear (104) and the sun gear (101) meshed therewith, the connection lines of Q1, Q2 and Q3 therein form an equilateral triangle.

4. A multi-point meshing compound planetary gear reducer according to claim 1 or 3, characterized in that 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) are all integer multiples of 3.

5. A multi-point meshing composite planetary gear reducer according to claim 1, characterized in that, Needle bearings (103) are arranged between the double planetary gears (102) and the stud pins (108), and between the intermediate planetary gears (104) and the stud pins (108).

6. The multi-point meshing compound planetary gear reducer according to claim 1, wherein, At both ends of the double planetary gear (102), first gaskets (110) are provided between the double planetary gear (102) and the first planet carrier (106) and the second planet carrier (107) respectively, 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); several first avoidance holes (1101) are provided on the first gasket (110), and the stud (108) penetrates through the first avoidance holes (1101). A second gasket (111) is provided between the first planetary gear (1021) and the intermediate planetary gear (104). Second avoidance holes (1111) and third avoidance holes (1112) are arranged at intervals along the circumferential direction on the second gasket (111). The stud (108) penetrates through the second avoidance holes (1111), and the second planetary gear (1022) penetrates through the third avoidance holes (1112).

7. A multi-point meshing compound planetary gear reducer according to claim 1, characterized in that, It further includes a coupling sleeve (109), a screw (112), a first bearing (113), a second bearing (114) and a third bearing (115). The stud (108) is fixedly connected to the first planet carrier (106) and the second planet carrier (107) through the screw (112). 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 planet carrier (106). The second bearing (114) is located between the input shaft (100) and the second planet carrier (107). The third bearing (115) is located between the housing (105) and the first planet carrier (106), and between the housing (105) and the second planet carrier (107).

8. A multi-point meshing compound planetary gear reducer according to claim 1, characterized in that, Nano coatings are 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).

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

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

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