Double inner-cycloid precision reducer and reduction module

Abstract

This invention relates to the field of cycloidal speed reducer modules, specifically to a double internal cycloidal precision reducer and speed reducer module, comprising a housing, an output component, an end cover, an input eccentric shaft, and pins; n eccentric portions are fixedly arranged on the input eccentric shaft; cycloidal gears are arranged on the eccentric portions, and the tooth profile of the cycloidal gears adopts a first internal cycloidal tooth profile generated by a first base circle and a first internal rolling circle; an internal gear ring is fixedly arranged on the housing, and the tooth profile of the internal gear ring adopts a second internal cycloidal tooth profile generated by a second base circle and a second internal rolling circle; the internal gear ring and the cycloidal gears form a double internal cycloidal transmission internal meshing pair through the first and second internal cycloidal tooth profiles; the cycloidal gears have several pin holes along the circumference, and the pins are fixedly connected to the output component. This invention optimizes the meshing pair in the traditional cycloidal reducer into a double internal cycloidal transmission internal meshing pair, achieving reasonable control of the meshing area, reducing the relative sliding speed of the contact points during meshing, reducing friction loss, and simplifying the overall process.

Description

Technical Field

[0001] This invention relates to the field of cycloidal deceleration module technology, specifically to a double internal cycloidal precision reducer and deceleration module. Background Technology

[0002] In the field of precision transmission for robot joints, cycloidal joint modules are a new type of precision transmission module that has gradually achieved industrial application in recent years. Its core transmission mechanism is based on the cycloidal pinwheel meshing transmission principle of the cycloidal reducer, which realizes the functions of speed reduction and torque multiplication through the conjugate meshing motion of the cycloidal wheel and the pin gear ring.

[0003] However, existing cycloidal joint modules still have certain technical limitations. For example, in existing cycloidal modules, there is significant sliding friction during the meshing process between the cycloidal wheel and the pin tooth ring, resulting in meshing losses that limit the improvement of transmission efficiency and make it difficult to meet the design requirements of lightweight robot joints and the control requirements of high-speed dynamic movements in high-end robots. In addition, the overall structure of the cycloidal wheel and pin tooth ring has extremely strict requirements for geometric tolerances, and high manufacturing and assembly precision leads to high mass production costs.

[0004] Meanwhile, existing cycloidal reducers also have room for improvement in terms of long-term operational reliability, uniformity of tooth surface stress distribution, and transmission smoothness. Summary of the Invention

[0005] To address the shortcomings of existing reducers, this invention provides a double internal cycloidal precision reducer and reduction module. It optimizes the meshing pair in the traditional cycloidal reducer into a double internal cycloidal transmission internal meshing pair, achieving reasonable control of the meshing area and effectively reducing the relative sliding speed of the contact points during meshing, thereby reducing friction loss. At the same time, this structural design simplifies the manufacturing and assembly process, improves production efficiency and consistency, and provides a solution for high-performance, low-cost robot joint transmission.

[0006] The technical solution provided by this invention is: a double internal cycloidal precision reducer, characterized in that it includes a housing, an output component, an end cover, an input eccentric shaft, and a pin; the end cover is fixed to one side of the housing, and the output component is rotatably disposed on the other side of the end cover; n eccentric portions are fixedly disposed on the input eccentric shaft, n≥1; cycloidal gears are disposed on the eccentric portions, and the tooth profile of the cycloidal gears adopts a tooth profile with a radius of R. b1 The first internal cycloidal gear profile is generated by a first base circle and a first inner rolling circle with a radius of r1, and the number of teeth of the cycloidal gear is N1; an internal gear ring is fixedly provided on the housing, and the tooth profile of the internal gear ring is formed by a first inner rolling circle with a radius of R. b2The second cycloidal tooth profile is generated by the second base circle and the second inner rolling circle with radius r2, and the number of teeth of the internal gear ring is N2; the first base circle is inscribed in the second base circle, and N2 > N1, r1 = r2; there is a center distance a between the eccentric part and the input eccentric shaft, satisfying a = R b2 -R b1 Both the first and second internal cycloidal tooth profiles are internal cycloidal tooth profiles or internal cycloidal fully supported equidistant tooth profiles. The internal gear ring and the cycloidal gear form a double internal cycloidal transmission internal meshing pair through the first and second internal cycloidal tooth profiles. The cycloidal gear is provided with several pin holes along its circumferential direction. The pins are fixedly connected to the output component, and the pins pass through the pin holes and tangentially abut against the inner wall of the pin holes, so as to convert the revolution of the cycloidal gear into the rotation of the output component and output it.

[0007] Optionally, the first and second cycloidal tooth profiles are generated by the following equation: ; Where R is the pitch circle radius, R is taken as R1 when generating the first cycloidal tooth profile, and R is taken as R2 when generating the second cycloidal tooth profile, and R2 > R1; satisfying R b1 =R1+r1;R b2 =R2+r2; e is the eccentricity, and the same eccentricity e is used when generating the first and second cycloidal tooth profiles; r d To ensure equidistant dimensions, the first and second cycloidal tooth profiles are generated using equal equidistant dimensions r. d r d ≥0; z is the cycloidal tooth profile parameter. When generating the first cycloidal tooth profile, z takes z1, and when generating the second cycloidal tooth profile, z takes z2, satisfying z2>z1, r1=R1 / z1=r2=R2 / z2; and satisfying N1=z1+1, N2=z2+1.

[0008] Optionally, there is a tooth difference ΔN between the cycloidal gear and the internal gear ring, where ΔN = N2 - N1, and ΔN takes values ​​from 1 to 3.

[0009] Optionally, when the equidistant dimension r d When r is not equal to 0, d It is 0.5-2.5 times the eccentricity e.

[0010] Optionally, when n=2, and two eccentric parts are fixedly provided on the input eccentric shaft, the phase difference between adjacent eccentric parts is 180 degrees.

[0011] Optionally, a needle roller bearing is provided between the eccentric part and the cycloidal gear; a crossed roller bearing is provided between the housing and the output component; and ball bearings are provided between the input eccentric shaft, the output component, and the end cover.

[0012] A speed reduction module includes the aforementioned double cycloidal precision speed reducer.

[0013] Optionally, it also includes a rotor, wherein the input eccentric shaft is fixedly connected to the rotation center of the rotor, and a magnet is provided on the rotor; the housing includes an outer wall, and a stator is provided on the side of the internal gear ring facing the outer wall, wherein the magnet engages with the stator inductively.

[0014] Compared with the prior art, the technical solution provided by this invention has the following beneficial effects: In view of the shortcomings of existing reducers, this invention optimizes the meshing pair in the traditional cycloidal reducer into a double internal cycloidal transmission internal meshing pair, realizing reasonable control of the meshing area, effectively reducing the relative sliding speed of the contact points during meshing, thereby reducing friction loss. At the same time, this structural design simplifies the manufacturing and assembly process, improves production efficiency and consistency, and provides a solution for high-performance, low-cost robot joint transmission. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the double internal cycloidal precision reducer proposed in an embodiment of the present invention.

[0016] Figure 2 This is a cross-sectional structural schematic diagram of the double internal cycloidal precision reducer proposed in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the internal structure of the double internal cycloidal precision reducer proposed in an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the meshing of the first and second cycloidal tooth profiles proposed in an embodiment of the present invention. Detailed Implementation

[0019] 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.

[0020] 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. Example 1

[0021] Combined with appendix Figure 1 To be continued Figure 4 This embodiment proposes a double internal cycloidal precision reducer, including a housing 1, an output component 3, an end cover 11, an input eccentric shaft 8, and pins 70. The end cover 11 is fixed to one side of the housing 1, and the output component 3 is rotatably mounted on the other side of the end cover 11. The input eccentric shaft 8 has n eccentric portions 80 fixedly mounted, where n ≥ 1.

[0022] A cycloidal gear 6 is provided on the eccentric part 80. The tooth profile of the cycloidal gear 6 adopts a tooth profile with a radius of R. b1 The first inner cycloidal tooth profile is generated by the first base circle and the first inner rolling circle with radius r1, and the number of teeth of the cycloidal gear 6 is N1.

[0023] An internal gear ring 10 is fixedly mounted on the housing 1. The tooth profile of the internal gear ring 10 is composed of a radius of R. b2The second cycloidal tooth profile is generated by the second base circle and the second inner rolling circle with radius r2, and the number of teeth of the inner gear ring 10 is N2.

[0024] The first base circle is inscribed in the second base circle, and N2 > N1, r1 = r2; there is a center distance a between the eccentric part 80 and the input eccentric shaft 8, satisfying a = R b2 -R b1 .

[0025] Both the first and second internal cycloidal tooth profiles are internal cycloidal tooth profiles or internal cycloidal fully supported equidistant tooth profiles. The internal gear ring 10 and the cycloidal gear 6 form a double internal cycloidal transmission internal meshing pair through the first and second internal cycloidal tooth profiles.

[0026] The cycloidal gear 6 has several pin holes 71 along its circumference. The pin 70 is fixedly connected to the output component 3, and the pin 70 passes through the pin hole 71 and abuts against the inner wall of the pin hole 71, so as to convert the planetary motion of the cycloidal gear 6 into the rotation of the output component 3 and output it.

[0027] The transmission principle of the double internal cycloidal precision reducer in this embodiment is as follows: the input eccentric shaft 8 rotates, and the internal gear ring 10 and the cycloidal gear 6 are connected by the first internal cycloidal tooth profile and the second internal cycloidal tooth profile to form a double internal cycloidal transmission internal meshing pair to achieve transmission, so that the cycloidal gear 6 performs planetary motion relative to the internal gear ring 10. The pin 70 converts the planetary revolution motion of the cycloidal gear 6 into the rotational motion of the output component 3 around the geometric center, and the output is realized through the output component 3.

[0028] For a double internal cycloidal precision reducer, n eccentric parts 80 are fixedly arranged on the input eccentric shaft 8. The eccentric parts 80 are used to assemble the cycloidal gear 6 so that the cycloidal gear 6 can achieve eccentric rotation during the rotation of the input eccentric shaft 8. Generally, at least one or more eccentric parts 80 are provided. In practice, when only one eccentric part 80 is provided, there will be a dynamic imbalance, which will cause the reducer to vibrate. Therefore, in this embodiment, two eccentric parts are preferably provided, which can improve the load-bearing capacity.

[0029] In this embodiment, both the first and second cycloidal tooth profiles are cycloidal tooth profiles or equidistant cycloidal tooth profiles with full branch. Their shapes can be referenced in the appendix. Figure 4 Among them, the equidistant tooth profile of the cycloid refers to the continuous tooth surface formed by equidistant offset along the normal direction after the tooth shape is generated based on the cycloid theory (i.e., after the cycloid tooth profile is generated). This tooth profile can ensure that the sliding speed of the contact point is reduced during meshing.

[0030] Specifically, the tooth profile of the cycloidal gear 6 adopts a first internal cycloidal tooth profile formed by a first base circle and a first inner rolling circle. The number of teeth of the cycloidal gear 6 is N1, and the radius of the first base circle is R. b1The radius of the first inner rolling circle is r1. The tooth profile of the internal gear ring 10 adopts a second internal cycloidal tooth profile generated by the second base circle and the second inner rolling circle. The number of teeth of the internal gear ring 10 is N2, and the radius of the second base circle is R. b2 The radius of the second inner rolling circle is r2. Understandably, in order to satisfy the meshing relationship between the cycloidal gear 6 and the internal gear ring 10, the first base circle needs to be internally tangent to the second base circle, and obviously, the radius r1 of the first inner rolling circle is smaller than the radius r2 of the second inner rolling circle.

[0031] In this embodiment, in order to ensure effective meshing between the internal gear ring 10 and the cycloidal gear 6, as a meshing condition, there is a center distance a between the eccentric part 80 and the input eccentric shaft 8, satisfying a=R. b2 -R b1 Therefore, by setting the center distance 'a', it is ensured that the first base circle and the second base circle can be internally tangent. Thus, the internal gear ring 10 and the cycloidal gear 6 form a double internal cycloidal transmission internal meshing pair through the first internal cycloidal tooth profile and the second internal cycloidal tooth profile.

[0032] Furthermore, when the first and second internal cycloidal tooth profiles mesh, clearances are maintained between the tooth profiles except in the meshing area, making it less prone to interference during transmission. Therefore, compared to traditional cycloidal pinwheel reducers, the reducer in this embodiment has relatively relaxed geometric tolerance requirements and lower manufacturing and assembly precision requirements, thus reducing mass production costs.

[0033] In this embodiment, the pin 70 passes through the pin hole 71 and abuts tangentially against the inner wall of the pin hole 71. The output component 3 is driven to move by the contact between the pin 70 and the pin hole 71. Specifically, the inner diameter of the pin hole 71 needs to be larger than the diameter of the pin 70 to avoid interference and jamming, and to meet the transmission requirements.

[0034] Specifically, in this embodiment, the first and second cycloidal tooth profiles are generated by the following equation: ; Where R is the pitch circle radius, R is taken as R1 when generating the first cycloidal tooth profile, and R is taken as R2 when generating the second cycloidal tooth profile, and R2 > R1; satisfying R b1 =R1+r1;R b2 =R2+r2.

[0035] e is the eccentricity, and the eccentricity e is taken to be equal when generating the first cycloidal tooth profile and the second cycloidal tooth profile.

[0036] r d To ensure equidistant dimensions, the first and second cycloidal tooth profiles are generated using equal equidistant dimensions r. d r d ≥0.

[0037] z is the cycloidal tooth profile parameter. When generating the first cycloidal tooth profile, z takes the value z1, and when generating the second cycloidal tooth profile, z takes the value z2, satisfying z2>z1, r1=R1 / z1=r2=R2 / z2; and satisfying N1=z1+1, N2=z2+1.

[0038] According to the above equation, when r d When r = 0, the first and second cycloidal tooth profiles are the corresponding theoretical cycloidal tooth profiles obtained without equidistant modification, and the equidistant dimension is 0. d When the value is greater than 0, in this embodiment, the first and second cycloidal tooth profiles are generated with equal equidistant dimensions r. d The first and second internal cycloidal tooth profiles are the corresponding equidistant tooth profiles of the entire branch of the internal cycloidal axis. Based on Camus' theorem, the meshing between the theoretical internal cycloidal tooth profiles is conjugate, and r d Since they are equal, meshing interference caused by the difference in offset is avoided, and the corresponding fully supported equidistant tooth profiles are also conjugate.

[0039] Preferably, the equidistant dimension r d ≥0, by optimizing the equidistant parameter r d This allows for a larger radius of curvature in the tooth profile. Compared to the theoretical tooth profile of the cycloidal gear, the fully supported equidistant tooth profile can, to some extent, improve the abrupt change in curvature between the tooth tip and root, resulting in a more uniform distribution of contact stress and increased strength at the tooth tip, thus leading to superior transmission performance. In this embodiment, when the external cycloidal gear and the internal gear ring 10 mesh with the corresponding cycloidal fully supported equidistant tooth profile, the relative sliding speed at the meshing point can be reduced, lowering friction loss. Compared to the existing technology where the meshing of the cycloidal wheel and the pin gear ring involves local sliding friction, this solution uses a cycloidal fully supported equidistant tooth profile to make the relative motion at the contact point closer to pure rolling, reducing sliding friction, reducing energy loss, improving transmission efficiency, and contributing to a higher dynamic response rate.

[0040] It is important to note that the equations used to generate the first and second cycloidal tooth profiles contain an eccentricity e. This eccentricity e refers to the distance from a point within the inner circumference to the center of that inner circumference when the corresponding cycloid is generated. For both the first and second cycloidal tooth profiles, the eccentricity e is equal.

[0041] Therefore, the eccentricity e in this embodiment is not equivalent to the aforementioned center distance a. This is because, based on the analysis of the meshing conditions, the improved double internal cycloidal transmission internal meshing pair in this embodiment needs to further ensure that the first base circle is tangent to the second base circle (in fact, the first pitch circle is also tangent to the second pitch circle). Clearly, taking the center of the internal gear ring 10 (or the second internal cycloidal tooth profile) as a reference point, the cycloidal gear 6 containing the first internal cycloidal tooth profile needs a greater offset to compensate for the gap between the first and second internal cycloidal tooth profiles. That is, the center distance a needs to be greater than the eccentricity e to ensure the correct meshing of the internal gear ring 10 and the cycloidal gear 6.

[0042] As can be seen from the foregoing embodiments, the double internal cycloidal precision reducer in this embodiment converts the planetary motion of the cycloidal gear 6 into the rotation of the output component 3 and outputs it by tangentially abutting the inner wall of the pin 70 and the pin hole 71. (See attached diagram.) Figure 3 It is known that there is also a center distance between the pin hole 71 and the pin 70 to prevent the relative movement of the pin 70 and the pin hole 71 from jamming. Thus, the planetary motion of the cycloidal gear 6 is converted into a rotational output around the center of the internal gear ring 10 through the cooperation of the pin 70 and the pin hole 71. The pin 70 and the pin hole 71 are evenly distributed in the circumferential direction. This cooperation relationship restricts the rotation component of the cycloidal gear 6, and only the revolution component is transmitted to the output component 3.

[0043] For the double internal cycloidal precision reducer in this embodiment, in order to ensure the reduction transmission between the internal gear ring 10 and the cycloidal gear 6, according to the speed ratio formula i=N2 / (N2-N1), the number of teeth N2 of the internal gear ring 10 should be greater than the number of teeth N1 of the cycloidal gear 6, that is, there is a tooth difference ΔN between the cycloidal gear 6 and the internal gear ring 10. Generally, the difference between the number of teeth N1 of the cycloidal gear 6 and the number of teeth N2 of the internal gear ring 10 should be at least 1; if it is 0, there is no reduction effect.

[0044] In a preferred embodiment, ΔN takes the value between 1 and 3. Generally, the larger the difference between N2 and N1 (i.e., ΔN), the better R... b2 With R b1 The larger the difference, the greater the difference between the pin hole 71 and the pin 70 will be. As can be seen from the above description, in order to achieve output, the diameter difference between the pin hole 71 and the pin 70 will also be larger. However, when the pin hole 71 is too large, the pin 70 hole may not be able to be arranged because the disk space of the output component 3 takes priority. Therefore, the upper limit of △N is preferably 3.

[0045] Understandably, due to the small ΔN, in the actual operation of the double internal cycloidal precision reducer, the internal meshing pair of the double internal cycloidal transmission formed by the cycloidal gear 6 and the internal gear ring 10 forms a multi-tooth synchronous contact state, which can effectively avoid the problem of excessive load on a single tooth. Furthermore, through this tooth number difference design, the continuity of the meshing trajectory is enhanced, and the distribution of contact stress on the tooth surface tends to be more uniform.

[0046] Therefore, the double internal cycloidal precision reducer in this embodiment can obviously reduce the tooth surface wear rate and extend the service life of the transmission mechanism, while improving the vibration and noise problems caused by tooth surface slippage during dynamic transmission. Furthermore, the optimized design of the tooth number difference further enhances the stability of the multi-tooth meshing state, providing a foundation for high-precision transmission.

[0047] Furthermore, combining the aforementioned equations and corresponding explanations, it can be seen that during the tooth profile generation process, the pitch circle radius R and the eccentricity e jointly determine the shape of the basic cycloid, while the equidistant dimension r d Controlling the magnitude of tooth profile offset, equidistant dimension r d The size of r directly affects the geometry and mechanical properties of the tooth tip profile. By adjusting r... d The value of r can change the tooth tip arc thickness and tooth root clearance, thereby balancing the tooth surface contact stress and bending strength. For example, when r d As the diameter increases, the tooth tip arc thickness increases, enhancing the bending resistance at the tooth tip; however, it is necessary to ensure that no interference occurs at the tooth root. As a preferred embodiment, when the equidistant dimension r... d When r is not equal to 0, d The eccentricity e can be 0.5-2.5 times, used to adjust the overall tooth profile, tooth tip arc, and tooth thickness, thereby increasing the bending strength of the tooth tip. In actual design, this can be determined through finite element analysis and engineering experience. In other words, this implementation method, by designing a range of equidistant dimensions, enables the tooth tip structure to achieve higher load-bearing capacity with the same amount of material, extending the service life of transmission components. It also avoids the increase in overall machine weight caused by forcing an increase in material usage due to insufficient tooth tip strength, or the increase in cost caused by changing material selection.

[0048] In this embodiment, two eccentric portions 80 are provided, i.e., n=2. Preferably, the phase difference between adjacent eccentric portions 80 is 180 degrees. The 180-degree phase difference makes the two adjacent eccentric portions 80 centrally symmetrically arranged, and the two cycloidal gears 6 form a 180-degree complementary distribution in the circumferential direction. Since the center distance between the two eccentric portions 80 and the input eccentric shaft 8 is equal, the motion trajectory formed by the two cycloidal gears 6 during meshing is symmetrical, making the load distribution of the meshing gear pair tend to be uniform. At the same time, the 180-degree phase difference arrangement makes the centrifugal force vectors generated by the two cycloidal gears 6 mutually balanced, so that the inertial forces generated by the cycloidal gears 6 during motion cancel each other out, effectively suppressing the vibration of the transmission system.

[0049] Theoretically, there can be three or more eccentric parts 80, with the n eccentric parts 80 evenly distributed circumferentially and the phase difference between adjacent eccentric parts 80 being 360° / n. However, in practice, three or more eccentric parts 80 would lead to a complex shape of the input eccentric shaft 8 and difficulties in assembling the cycloidal gear 6. Therefore, it is preferable to set two eccentric parts 80.

[0050] Furthermore, in this embodiment, a needle roller bearing 9 can be provided between the eccentric portion 80 and the cycloidal gear 6 to ensure the smoothness and stability of the cycloidal gear 6 during planetary motion. A crossed roller bearing 2 can also be provided between the housing 1 and the output component 3 to ensure the stability of the output component 3's movement. Similarly, a ball bearing 12 can be provided between the input eccentric shaft 8 and the output component 3 and end cover 11. The ball bearing 12 provides support to both ends of the input eccentric shaft 8 and improves the smoothness of its movement.

[0051] The following comparison of the double internal cycloidal precision reducer of this embodiment with the traditional cycloidal pinwheel reducer and the double external cycloidal reducer is performed. The relevant parameters and conditions are set as follows: the number of teeth of the cycloidal gear is 60, the tooth difference is 1, e=0.75mm, the center distance is 80mm, the speed is 1000r / min, grease lubrication is used, and the room temperature is 40°C. The comparison results are shown in the table below: As can be seen from the table, the double internal cycloidal precision reducer in this embodiment has more teeth meshing simultaneously during operation. Furthermore, based on actual observation and simulation, compared to the double external cycloidal reducer, the double internal cycloidal precision reducer has a wider contact surface between tooth profiles during meshing, resulting in a better meshing effect.

[0052] Furthermore, the contact stress σ present in the double internal cycloidal precision reducer during meshing. H It is also relatively smaller; compared to a double external cycloidal reducer, the contact stress σ of a double internal cycloidal precision reducer is lower. H It reduces slippage by approximately 27%. The slip ratio is also relatively smaller; the surface-mounted double internal cycloidal precision reducer has a higher pure rolling ratio during meshing, resulting in higher single-stage efficiency and advantages in noise control. Furthermore, due to its better tooth profile design and greater tolerance, the double internal cycloidal precision reducer also exhibits better backlash control. Additionally, its torsional stiffness is superior.

[0053] In summary, this embodiment addresses the technical shortcomings of existing reducers, particularly the problem of excessively high sliding speeds in traditional cycloidal pinwheel meshing, leading to transmission efficiency losses. This embodiment optimizes the meshing pair in the traditional cycloidal reducer into a double internal cycloidal transmission internal meshing pair composed of internal cycloidal tooth profiles or internal cycloidal fully supported equidistant line tooth profiles. This achieves reasonable control of the meshing area, effectively reducing the relative sliding speed of the contact points during meshing, thereby reducing frictional losses. Simultaneously, this structural design simplifies manufacturing and assembly processes, improves production efficiency and consistency, and provides a solution for high-performance, low-cost robot joint transmission. Example 2

[0054] Combined with appendix Figure 1 To be continued Figure 4 This embodiment proposes a speed reduction module, including the double cycloidal precision speed reducer described in the technical solution of Embodiment 1.

[0055] The reduction module in this embodiment, which includes a double internal cycloidal precision reducer, can be combined with a motor, thus solving the problem that traditional cycloidal reducers, where the motor and reducer are independent, result in a complex transmission chain and difficulty in compressing the axial dimension. Specifically, it also includes a rotor 4, with an input eccentric shaft 8 fixedly connected to the rotation center of the rotor 4, and a magnet 40 disposed on the rotor 4; the housing 1 includes an outer wall 100, and a stator 5 is disposed on the side of the internal gear ring 10 facing the outer wall 100, with the magnet 40 and the stator 5 inductively engaging to form a motor assembly.

[0056] When the reduction module is working, the stator 5 is energized. Through the inductive interaction between the magnet 40 and the stator 5, the rotor 4 rotates, which in turn drives the input eccentric shaft 8 to rotate. The internal gear ring 10 and the cycloidal gear 6 form a double internal cycloidal transmission internal meshing pair through the first internal cycloidal tooth profile and the second internal cycloidal tooth profile to achieve transmission. This causes the cycloidal gear 6 to perform planetary motion relative to the internal gear ring 10. The pin 70 converts the planetary revolution motion of the cycloidal gear 6 into the rotational motion of the output component 3 around the geometric center, and output is achieved through the output component 3.

[0057] In this implementation, the motor rotor 4 is directly coupled to the input eccentric shaft 8, and the motor stator 5 winding is directly mounted on the internal gear ring 10. This integrates the motor and the reducer, forming a compact reduction module. This eliminates the need for traditional separate couplings and support frames, reduces intermediate connecting components, and minimizes axial space occupation, effectively resolving the conflict between the built-in reducer and the axial space occupied by the motor. Furthermore, as shown in the attached... Figure 2 In the embodiment shown, a bearing can be provided between the rotor 4 and the end cover 11 to support and stabilize the rotor 4 through the end cover 11, thereby ensuring the stability of the rotor 4's movement.

[0058] The deceleration module of this embodiment can be applied in the field of robotics as a joint module for robots (or robot dogs), meeting the design requirements of lightweight robot joints and the control requirements of high-speed dynamic movements in high-end robots. Of course, the deceleration module of this embodiment is not limited to the field of robotics and can also be applied to other fields where deceleration modules are applicable.

[0059] 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 double internal cycloidal precision reducer, characterized in that, It includes a housing (1), an output component (3), an end cover (11), an input eccentric shaft (8), and a pin (70); the end cover (11) is fixed to one side of the housing (1), and the output component (3) is rotatably disposed on the other side of the end cover (11); The input eccentric shaft (8) is fixedly provided with n eccentric parts (80), where n≥1; A cycloidal gear (6) is provided on the eccentric part (80), and the tooth profile of the cycloidal gear (6) adopts a tooth profile with a radius of R. b1 The first inner cycloidal tooth profile is generated by the first base circle and the first inner rolling circle with radius r1, and the number of teeth of the cycloidal gear (6) is N1; An internal gear ring (10) is fixedly mounted on the housing (1), and the tooth profile of the internal gear ring (10) is formed by a radius of R. b2 The second cycloidal tooth profile is generated by the second base circle and the second inner rolling circle with radius r2, and the number of teeth of the inner tooth ring (10) is N2; The first base circle is inscribed in the second base circle, and N2 > N1, r1 = r2; there is a center distance a between the eccentric part (80) and the input eccentric shaft (8), satisfying a = R b2 -R b1 ; The first and second cycloidal tooth profiles are both cycloidal tooth profiles or cycloidal tooth profiles with full support and equidistant line. The internal gear ring (10) and the cycloidal gear (6) form a double cycloidal transmission internal meshing pair through the first and second cycloidal tooth profiles. The cycloidal gear (6) is provided with a plurality of pin holes (71) along the circumferential direction. The pin (70) is fixedly connected to the output component (3), and the pin (70) passes through the pin hole (71) and abuts against the inner wall of the pin hole (71) in order to convert the revolution of the cycloidal gear (6) into the rotation of the output component (3) and output it.

2. The double internal cycloidal precision reducer according to claim 1, characterized in that, The first and second cycloidal tooth profiles are generated by the following equations: ； Where R is the pitch circle radius, R is taken as R1 when generating the first cycloidal tooth profile, and R is taken as R2 when generating the second cycloidal tooth profile, and R2 > R1; satisfying R b1 =R1+r1;R b2 =R² + r²; e is the eccentricity, and the eccentricity e is taken to be equal when generating the first cycloidal tooth profile and the second cycloidal tooth profile; r d To ensure equidistant dimensions, the first and second cycloidal tooth profiles are generated using equal equidistant dimensions r. d r d ≥0; z is the cycloidal tooth profile parameter. When generating the first cycloidal tooth profile, z takes the value z1, and when generating the second cycloidal tooth profile, z takes the value z2, satisfying z2>z1, r1=R1 / z1=r2=R2 / z2; and satisfying N1=z1+1, N2=z2+1.

3. A double internal cycloidal precision reducer according to claim 1 or 2, characterized in that, There is a tooth difference ΔN between the cycloidal gear (6) and the internal gear ring (10), where ΔN = N2 - N1, and ΔN ranges from 1 to 3.

4. A double internal cycloidal precision reducer according to claim 2, characterized in that, When the equidistant dimension r d When r is not equal to 0, d It is 0.5-2.5 times the eccentricity e.

5. A double internal cycloidal precision reducer according to claim 1, characterized in that, When n=2, and two eccentric parts (80) are fixedly provided on the input eccentric shaft (8), the phase difference between adjacent eccentric parts (80) is 180 degrees.

6. A double internal cycloidal precision reducer according to claim 1, characterized in that, A needle roller bearing (9) is provided between the eccentric part (80) and the cycloidal gear (6); a cross roller bearing (2) is provided between the housing (1) and the output part (3); and ball bearings (12) are provided between the input eccentric shaft (8), the output part (3), and the end cover (11).

7. A speed reduction module, characterized in that, Including the double internal cycloidal precision reducer as described in any one of claims 1-6.

8. A speed reduction module according to claim 7, characterized in that, It also includes a rotor (4), the input eccentric shaft (8) is fixedly connected to the rotation center of the rotor (4), and a magnet (40) is provided on the rotor (4); the housing (1) includes an outer wall (100), and a stator (5) is provided on the side of the inner gear ring (10) facing the outer wall (100), and the magnet (40) and the stator (5) are inductively engaged.

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