Built-in cycloid speed reducer of humanoid robot joint disc output structure and joint module

Abstract

The invention discloses a built-in cycloid speed reducer of a humanoid robot joint disc output structure and a joint module. The problems that an existing robot joint module is large in size, insufficient in transmission precision and bearing capacity and the like are solved. The joint module adopts a compact built-in design, the motor and the cycloid speed reducer are integrated, the cycloid speed reducer adopts a disc output structure, and the joint module has the advantages of high integration level, high transmission precision, large torque, high rigidity, strong impact resistance, long service life and the like, and is particularly suitable for the requirements of humanoid robot joints on compactness and high performance. And the tooth profile of the cycloidal gear adopts a parabola modification method, so that the meshing characteristic is further optimized, the transmission stability is improved, and the transmission error is reduced. Complete self-sealing is achieved, secondary pollution to the operation environment of the robot is avoided, a simple and convenient installation mode is achieved, the two ends of the input crankshaft are supported by the cylindrical roller bearings, and radial force can be directly borne.

Description

Technical Field

[0001] The present invention belongs to the technical field of robot joint driving, and in particular relates to a built-in cycloid transmission joint module applied to a humanoid robot joint. Background Art

[0002] With the continuous development of Industry 4.0 and intelligent manufacturing, robots, as an important part of high-end manufacturing, the research and development of their core components is of vital importance. Robot joint reducers are one of the key components. Currently, there are few mature products on the market and they face serious production capacity shortages, which cannot meet the rapid development needs of the robotics industry. Robot reducers have strict requirements on size, transmission accuracy, load-bearing capacity, sealing and impact resistance, so there are certain requirements for the transmission method and structure of the reducer. Reducers designed with cycloid pinwheel transmission have the advantages of small size, light weight, compact structure, large load-bearing capacity, strong impact resistance, smooth transmission and large transmission ratio. This transmission method is increasingly used in the field of precision transmission and is very suitable for the requirements of robot reducers.

[0003] Existing robot joint reducers mainly include harmonic reducers and RV reducers. Harmonic reducers use elastic element deformation transmission and are only suitable for small load and small impact situations. However, they have low torsional stiffness, cannot withstand large loads, and have poor impact resistance. They are generally used in small, low-load robot joints. Although RV reducers have high stiffness, large load capacity, and strong impact resistance, their two-stage transmission method leads to a complex structure, a large number of parts, high processing and assembly precision requirements, high cost, and large size. These factors limit their application in humanoid robot joints with more stringent requirements on size and performance.

[0004] Traditional cycloid pinwheel reducers also present challenges in tooth profile design and manufacturing. To ensure transmission accuracy and service life, the cycloid gear tooth profile requires modification to compensate for manufacturing errors, ensure lubrication, and facilitate assembly and disassembly. However, improper modification methods can lead to increased transmission errors and reduced meshing performance.

[0005] The purpose of the present invention is to provide a new type of humanoid robot joint disc output structure with a built-in cycloid reducer and joint module, aiming to solve the problems of existing robot joint modules such as large size, complex structure, insufficient transmission accuracy and load-bearing capacity, and to provide a solution with compact structure, high transmission accuracy, large load-bearing capacity, strong impact resistance, stable operation, long life and relatively low manufacturing cost. Summary of the Invention

[0006] The present invention provides a built-in cycloid reducer and joint module of a humanoid robot joint disc output structure, comprising a motor and a cycloid reducer. The cycloid reducer adopts a disc output structure and is built-inly connected to the motor to achieve an integrated design.

[0007] In one solution, a built-in cycloid reducer and joint module for a humanoid robot joint disc output structure are provided, including:

[0008] The motor is an outer rotor frameless motor. The rotor with an umbrella-shaped flange structure is directly connected to the cycloid pinwheel input crankshaft. The motor stator is sleeved on the built-in cycloid reducer housing and fixedly connected to the built-in cycloid reducer housing.

[0009] The input crankshaft is supported at both ends on the input support end and the output flange respectively through crankshaft support roller bearings.

[0010] Swing arm bearings, two swing arm bearings are installed on the eccentric outer circle in the middle of the input crankshaft.

[0011] The two cycloid wheels are respectively sleeved on the outside of the two arm bearings, and their outer tooth surfaces mesh with the pin teeth 6 in the housing to achieve a small tooth difference transmission. The number of teeth on the cycloid wheel is an odd number, one less than the number of teeth on the pin teeth on the housing, so that the cycloid wheel, the housing, and the pin teeth perform a planetary reduction motion with a small tooth difference.

[0012] The disc transmission components each have two first rectangular bosses at one end of each of the two cycloid wheels. These first bosses connect to two rectangular holes on the front and rear disc transmission components. The other two rectangular holes on the front and rear disc transmission components connect to the two second rectangular bosses on the output flange and the two third rectangular bosses on the input support end, respectively. Each rectangular hole in the disc transmission component is fitted with several cylindrical rollers. These rectangular holes form a rolling fit with the first rectangular boss of the cycloid wheel, the second rectangular boss of the output flange, and the third rectangular boss of the input support end, reducing friction and effectively improving the transmission efficiency of the reducer.

[0013] The output structure includes an input support end roller bearing sleeved onto the outside of the input support end. The housing sleeves onto the outside of the input support end roller bearing. The cylindrical cross roller sleeves onto the output flange and is connected to the housing and the bearing gland. A rotating skeleton oil seal is mounted on the bearing gland. The output flange and bearing gland are connected to the housing via locking bolts, nuts, and screws. The first rectangular boss on the cycloid wheel, the second rectangular boss on the output flange, and the third rectangular boss on the input support end are symmetrically arranged to form a force couple. These, in conjunction with the disc transmission, convert the cycloid wheel's planetary motion into circular motion.

[0014] The cycloid gear tooth profile of the present invention adopts a parabolic shaping method. The expression of the parabolic shaping amount ΔL is:

[0015] ΔL=a c (PK-PK0) n +b

[0016] Where PK is the distance between the meshing point and the node on the cycloid gear tooth profile at different meshing phase angles, PK0 is the distance between the meshing point and the node P at the initial reference point, a c is the parabola modification coefficient, n is the parabola modification order, usually n is an even number, and b is the constant term modification coefficient.

[0017] By superimposing the modification amount ΔL along the normal direction onto the theoretical cycloid gear tooth profile equation, the cycloid gear tooth profile equation can be obtained as follows:

[0018]

[0019] Among them, R p is the radius of the pinwheel, (R rp is the radius of the needle tooth, a is the eccentricity, is the pinwheel angle, i H is the transmission ratio of the cycloid pinwheel pair in the conversion mechanism, i H =z p / z c , z p is the number of pinwheel teeth, z c is the number of cycloid gear teeth, K1=az p / R p .

[0020] The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure provided by the present invention have the following beneficial effects:

[0021] The compact structure and small size utilize a first-stage cycloid drive structure. The input shaft is the crankshaft, and it is highly integrated with the motor rotor. Compared with RV reducers, the number of parts is reduced by over 50%, effectively reducing manufacturing difficulty and costs, reducing cumulative errors, and achieving assembly precision. This allows for a smaller installation size, meeting the strict joint volume requirements of humanoid robots.

[0022] To optimize meshing characteristics, the cycloidal gear tooth profile utilizes a parabolic modification method. While maintaining a similar profile to the standard tooth profile in the primary meshing section, appropriate clearances are left at the tooth tips and roots to facilitate lubrication and assembly, while also reducing transmission errors. Compared to equidistant shift modification, parabolic modification offers superior performance in terms of the number of teeth in simultaneous contact and maximum contact force.

[0023] High torsional rigidity and anti-overturning capability. Cylindrical rollers separate all components, creating a radial and axial output bearing structure, itself a combined bearing. The output flange 9 receives the strongest axial and radial loads and provides greater anti-overturning capability. The disc drive, cycloid gear boss, and output flange bosses cooperate to provide high torsional rigidity.

[0024] Good sealing performance and a fully self-sealing structure effectively avoid the problem of re-contamination of the reducer during use.

[0025] Simple installation: Both ends of the input crankshaft are supported by cylindrical roller bearings, which can directly bear radial forces without the need for additional support bearings.

[0026] Reducing manufacturing costs, reducing the number of parts, and easing processing difficulty facilitates mass production, thereby reducing product costs. By optimizing error distribution, manufacturing costs can be further reduced while ensuring transmission accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 This is a schematic diagram of the front and oblique side of a humanoid robot joint disc output structure with a built-in cycloid reducer and a joint module according to the present invention;

[0029] Figure 2 This is a schematic diagram of the anticline side product of a humanoid robot joint disc output structure with a built-in cycloid reducer and a joint module according to the present invention;

[0030] Figure 3 This is an exploded schematic diagram of the built-in cycloid reducer and joint module of the humanoid robot joint disc output structure described in the present invention, showing the assembly relationship of the main components;

[0031] Figure 4 This is an axial cross-sectional view of the built-in cycloid reducer and joint module of the humanoid robot joint disc output structure described in the present invention, clearly showing the internal structure;

[0032] Figure 5 This is a three-dimensional exploded schematic diagram of a built-in cycloid reducer and joint module of a humanoid robot joint disc output structure according to the present invention;

[0033] Figure 6This is an exploded schematic diagram of the built-in cycloid reducer and the disc output mechanism of the joint module of a humanoid robot joint disc output structure described in the present invention, showing the coordination of the cycloid wheel, disc, and output flange;

[0034] Figure 7 This is a schematic diagram of the parabolic modified tooth profile of the cycloid gear described in the present invention.

[0035] The reference numerals in the figure are: 1-input support end; 2-input crankshaft; 3-cylindrical roller bearing; 4-cycloid wheel; 5-housing; 6-pin gear; 8-disc transmission member; 9-output flange; 10-cylindrical cross roller; 11-bearing pressure cover; 12-crankshaft support roller bearing; 13-motor driver and end cover assembly; 14-motor rotor; 15-motor stator; 401-first rectangular boss; 801-cylindrical roller; 901-second rectangular boss; 101-third rectangular boss. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application. Similarly, the following examples are only some embodiments of the present application and not all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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 therefore should not be understood as limiting the present invention.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include at least one of these features.

[0039] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0040] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0041] In response to the above problems, the present application makes improvements and innovations and proposes the following embodiments.

[0042] In one embodiment, see Figure 1 、 Figure 2 、 Figure 3 The present invention provides a built-in cycloid reducer and joint module for a humanoid robot joint disc output structure. The built-in cycloid reducer mainly includes an input support end 1, an input crankshaft 2, a swing arm bearing 3, a cycloid wheel 4, a housing 5, pin teeth 6, a disc transmission member 8, an output flange 9, cylindrical cross rollers 10, a bearing gland 11, and a crankshaft support roller bearing 12. The external motor mainly includes a motor rotor 14 and a motor stator 15.

[0043] The motor is an outer rotor frameless motor. The umbrella-shaped flange structure rotor 14 is directly connected to the cycloid pinwheel input crankshaft 2. The motor stator 15 is sleeved on the built-in cycloid reducer housing 5 and fixedly connected to the built-in cycloid reducer housing 5.

[0044] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6The input crankshaft 2 is supported at both ends by crankshaft support roller bearings 12 on the input support end 1 and output flange 9, respectively. Two swing arm bearings 3 are mounted on the eccentric outer circle in the center of the input crankshaft 2. Two cycloid wheels 4 are respectively sleeved onto the outer sides of the two swing arm bearings 3, with their outer tooth surfaces meshing with the pinions 6 within the housing 5. The cycloid wheel 4 has an odd number of teeth, one less than the number of teeth on the pinions 6 on the housing 5. This allows the cycloid wheel 4, the housing 5, and the pinions 6 to perform a planetary reduction motion with one less tooth difference.

[0045] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 , each end of the two cycloid wheels 4 has two first rectangular bosses 401, and the first rectangular bosses 401 are connected to the two rectangular holes on the front and rear disc transmission parts 8. The other two rectangular holes of the front and rear disc transmission parts 8 are respectively connected to the two second rectangular bosses 901 of the output flange 9 and the two third rectangular bosses 101 of the input support end 1. Each rectangular hole of the disc transmission part 8 is installed with a number of cylindrical rollers 801, and the rectangular holes and the first rectangular boss 401 of the cycloid wheel 4, the second rectangular boss 901 of the output flange 9 and the third rectangular boss 101 of the input support end 1 are in rolling fit, which can reduce friction resistance and effectively improve the transmission efficiency of the reducer. The first rectangular boss 401 on the cycloid wheel 4, the second rectangular boss 901 on the output flange 9 and the third rectangular boss 101 on the input support end 1 are all symmetrically arranged.

[0046] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 The input support end 1 is sleeved with an input support end roller bearing 18 on its outer side. The housing 5 is sleeved on the outer side of the input support end roller bearing 18. The cylindrical cross roller 10 is sleeved on the output flange 9 and connected to the housing 5 and the bearing cover 11. A rotating skeleton oil seal 14 is installed on the bearing cover 11. The output flange 9 and the bearing cover 11 are connected to the housing 5 via locking bolts 15, nuts 16, and screws 17.

[0047] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6, this joint module drives the input crankshaft 2 to rotate through the motor rotor 14. After the input crankshaft 2 rotates, the swing arm bearing 3 installed on its eccentric circle pushes the cycloid wheel 4, causing it to mesh with the cylindrical needle teeth 6 in the housing 5, and perform a small tooth difference movement to form a deceleration. The two first rectangular bosses 401 on one of the cycloid wheels 4 drive the disc transmission part 8 through the cylindrical roller 801, and transmit the rotation to the second boss 901 of the output flange 9, causing the output flange 9 to rotate. The output flange 9 and the cylindrical cross roller 10, the bearing cover 11 and the housing 5 form a built-in cylindrical cross roller bearing, which provides axial and radial support for the output flange 9. The two first rectangular bosses 401 on the other cycloid gear 4, via cylindrical rollers 801, drive another disc transmission element 8, transmitting rotation to the third rectangular boss 101 on the input support end 1, causing it to rotate. The input support end 1 and the output flange 9 are connected integrally by locking bolts 15 and nuts 16, balancing and increasing the output torque. The input support end 1 is supported on the housing 5 by input support end roller bearings 18. A rotating skeleton oil seal 14, mounted on the bearing gland 11, seals the output flange 9.

[0048] In some embodiments, see Figure 7 The cycloid gear tooth profile adopts a parabolic modification method. The parabolic modification amount ΔL varies with the distance between the meshing point and the node on the cycloid gear tooth profile, thereby making the tooth profile as close as possible to the theoretical tooth profile during the main working section. This modification method ensures that multiple teeth can smoothly enter and exit meshing during the transmission process, avoiding impact and interference. At the same time, it optimizes the stress distribution in the contact area, improving the transmission accuracy, efficiency and service life of the reducer.

[0049] The present invention realizes a built-in, compact, high-performance humanoid robot joint module through the above-mentioned structure and shaping method, which has important theoretical significance and practical application value.

[0050] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A humanoid robot joint disc output structure with a built-in cycloid reducer and joint module, characterized by: The invention comprises a motor and a cycloid reducer. The cycloid reducer adopts a disc output structure and is internally connected with the motor to realize an integrated design.

2. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 1, characterized in that: The motor is an outer rotor frameless motor. The rotor is connected to the cycloid pinwheel input crankshaft through an umbrella-shaped flange structure. The motor stator is sleeved on the built-in cycloid reducer housing and fixedly connected to the built-in cycloid reducer housing.

3. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 1, characterized in that: The cycloid reducer includes an input support end, an input crankshaft, a swing arm bearing, a cycloid wheel, a housing, needle teeth, a disc transmission member, an output flange, a cylindrical cross roller, a bearing cover, and a crankshaft support roller bearing; the two ends of the input crankshaft are supported by crankshaft support roller bearings on the input support end and the output flange respectively; two swing arm bearings are installed on the eccentric outer circle in the middle of the input crankshaft; two cycloid wheels are respectively sleeved on the outer sides of the two swing arm bearings, and their outer tooth surfaces are engaged with the needle teeth in the housing; one end of each cycloid wheel has two first rectangular bosses, and the first rectangular bosses are connected to the two rectangular holes on the front and rear disc transmission members; the other two rectangular holes of the front and rear disc transmission members are respectively connected to the two second rectangular bosses on the output flange and the two third rectangular bosses on the input support end.

4. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 3, characterized in that: The outer side of the input support end is sleeved with an input support end roller bearing, the housing is sleeved on the outer side of the input support end roller bearing, the cylindrical cross roller is sleeved on the output flange, and is connected to the housing and the bearing cover. A rotating skeleton oil seal is installed on the bearing cover, and the output flange and the bearing cover are connected to the housing through locking bolts, nuts and screws.

5. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 3, characterized in that: The number of teeth of the cycloid wheel is an odd number, which is one less than the number of teeth of the pinion on the housing, so that the cycloid wheel, the housing and the pinion perform a planetary deceleration motion with one less tooth difference.

6. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 3, characterized in that: The first rectangular boss on the cycloid wheel, the second rectangular boss on the output flange, and the third rectangular boss on the input support end are all symmetrically arranged.

7. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 3, characterized in that: Each rectangular hole of the disc transmission member is equipped with a plurality of cylindrical rollers, and the rectangular hole is in rolling fit with the first rectangular boss of the cycloid wheel, the second rectangular boss of the output flange and the third rectangular boss on the input support end.

8. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 1, characterized in that: The cycloid gear tooth profile adopts a parabolic shaping method.

9. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 8, characterized in that: The expression of the parabola modification amount ΔL is: ΔL=a c (PK-PK0) n +b Where PK is the distance between the meshing point and the node on the cycloid gear tooth profile at different meshing phase angles, PK0 is the distance between the cycloid gear meshing point and the node P at the initial reference point, a c is the parabola modification coefficient, n is the parabola modification order, and b is the constant term modification coefficient.

10. The built-in cycloid reducer and joint module of the humanoid robot joint disc output structure according to claim 8, characterized in that: The tooth profile equation of the cycloid gear is: Among them, R p is the radius of the pinwheel, (R rp is the radius of the needle tooth, a is the eccentricity, is the pinwheel angle, i H is the transmission ratio of the cycloid pinwheel pair in the conversion mechanism, i H =z p / z c , z p is the number of pinwheel teeth, z c is the number of cycloid gear teeth, K1=az p / R p .

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