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

Abstract

The invention discloses a built-in cycloid speed reducer of a humanoid robot joint crosshead shoe output structure and a joint module. The problems that an existing robot joint module is large in size, complex in structure, insufficient in transmission precision and bearing capacity and the like are solved. According to the invention, the frameless torque motor and the cycloidal-pin wheel speed reducer are designed in an integrated built-in manner, so that the structure is highly compact; the cycloidal speed reducer adopts a cross slide block output structure, planetary motion of the cycloidal gear is efficiently converted into rotary motion of an output flange, and the structure has the advantages of being short in transmission chain, high in rigidity and small in return difference. In addition, a parabola modification method is adopted for the tooth profile of the cycloidal gear, the meshing characteristic of the gear is optimized, the transmission stability is improved, and noise is reduced. The joint module has the advantages of being high in integration level, high in torque density, high in rigidity, high in impact resistance, convenient and fast to install and the like, and is particularly suitable for humanoid robot joints with strict requirements for space and performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of core components of robots, and in particular relates to a joint module with an integrated motor and reducer design, specifically a joint module applied to the joints of a humanoid robot, which adopts a built-in cycloid pinwheel reducer and uses a cross slider as the output mechanism. Background Art

[0002] Robotics, particularly humanoid robots, is a key indicator of a country's technological innovation and high-end manufacturing capabilities. Joint modules, the "joints" of robots, are the core components that enable high-precision, high-dynamic response motion. Currently, the main reducers used in robot joints are harmonic reducers and RV reducers.

[0003] Harmonic reducers use the elastic deformation of flexible wheels to transmit motion and power. They have the advantages of large transmission ratio, small size and light weight. However, their disadvantages are also very obvious: low load-bearing capacity and stiffness, and poor impact resistance, which limits their application in joints such as the lower limbs of humanoid robots that require high load and high rigidity.

[0004] RV reducers (cycloidal planetary transmissions) typically utilize a two-stage reduction structure, characterized by excellent rigidity, strong load-bearing capacity, and impact resistance. However, their complex structure and large number of parts result in a large size and weight, making processing and assembly difficult and costly. For humanoid robots striving for extreme lightweight and compactness, the size and weight of traditional RV reducers present a bottleneck for their application.

[0005] Furthermore, in cycloid pinwheel transmissions, the theoretical tooth profile of the cycloid gear must be modified to ensure smooth meshing of multiple teeth, reduce impact and noise, and facilitate lubrication and assembly. While traditional tooth profile modification methods (such as equidistant shifting) can be effective, there is still room for improvement in optimizing transmission errors, increasing meshing rigidity, and enhancing transmission smoothness.

[0006] At the same time, how to more efficiently integrate the reducer and drive motor, further reduce the axial and radial dimensions of the joint module, and adopt a more optimized output structure to improve transmission rigidity and accuracy are key challenges in the current development of humanoid robot joint technology. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of existing technologies by providing a novel, highly integrated, and high-performance humanoid robot joint cross-slider output structure with a built-in cycloid reducer and joint module. This module is designed to achieve the goals of small size, light weight, high rigidity, high torque, high precision, and long life.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A humanoid robot joint with a cross-slider output structure and a built-in cycloid reducer and joint module includes a motor and a cycloid reducer built into the motor, forming an integrated joint module. The cycloid reducer includes an input mechanism, a cycloid wheel, a pinion housing, and an output mechanism. The input mechanism drives the cycloid wheel to perform planetary motion relative to the pinion housing. The core of the output mechanism is its cross-slider output structure, which converts the cycloid wheel's planetary motion (including revolution and rotation) into the rotational motion of the output flange.

[0010] In a preferred embodiment, the motor is an outer rotor frameless torque motor, the stator of which is fixedly mounted on the outer circumference of the pin-tooth housing, and the rotor is fixedly connected to the input crankshaft of the cycloid reducer, thereby achieving structural integration and effectively shortening the axial dimension of the joint.

[0011] The cross slider output structure is the key to the present invention. It includes a cross slider conversion element, a first guide mechanism (such as a slide groove) arranged on the end face of the cycloid wheel, a second guide mechanism (such as a slide groove) arranged on the end face of the output flange, and a third guide mechanism (such as a slide groove) arranged on the input support end. The cross slider conversion element has two mutually perpendicular sliding mechanisms, which slide with the first, second and third guide mechanisms respectively. When the cycloid wheel performs planetary motion, its revolution component is absorbed by the cooperation of the first guide mechanism and the first sliding mechanism, and only the rotation component is transmitted to the output flange through the cooperation of the second guide mechanism and the second sliding mechanism, thereby realizing precise conversion of motion. In order to improve efficiency and wear resistance, rolling elements such as needle rollers or rollers can be set between the slider and the slide groove to form a rolling friction pair.

[0012] To further improve transmission performance, the present invention employs a parabolic shaping method for the cycloidal gear tooth profile. This method dynamically adjusts the shaping amount based on the position of the cycloidal gear meshing point, bringing the tooth profile closer to the theoretical tooth profile in the primary meshing area to ensure load bearing and accuracy. Sufficient clearance is left in the tooth tip and tooth root areas to facilitate the formation of a lubricating oil film and reduce shock and vibration.

[0013] The expression of the parabola shaping amount ΔL of the present invention is:

[0014] ΔL=a c (PK-PK0) n +b

[0015] 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.

[0016] 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:

[0017]

[0018] 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 .

[0019] The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure provided by the present invention have the following beneficial effects:

[0020] 1. Highly integrated and compact structure: The integrated built-in design of the motor and reducer, combined with the efficient output mechanism of the cross slider, makes the axial and radial dimensions of the entire joint module extremely small and light in weight, which is very suitable for the lightweight requirements of humanoid robots.

[0021] 2. High transmission rigidity and small backlash: The cross slider output structure has a short transmission chain and is a rigid transmission. Compared with the flexible wheel transmission, it has higher torsional rigidity and smaller backlash, which can provide more precise positioning and faster dynamic response.

[0022] 3. Excellent meshing performance and smooth operation: The parabolic modified cycloid gear tooth profile makes multi-tooth meshing smoother, effectively reduces transmission error, vibration and noise, and improves the operation quality of the joint.

[0023] 4. Strong load-bearing capacity: The cycloid pinwheel transmission itself has the characteristics of multiple teeth meshing at the same time, which has a strong load-bearing capacity. The output flange is supported by a large-size cross roller bearing, which can withstand loads in various directions at the same time, ensuring the strength and rigidity of the joint.

[0024] 5. Relatively low manufacturing cost: Compared with the complex multi-stage transmission RV reducer, the present invention has a simpler structure and fewer parts, which reduces the difficulty and cost of processing and assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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;

[0026] 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;

[0027] 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;

[0028] 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;

[0029] 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;

[0030] Figure 6 This is an exploded schematic diagram of the built-in cycloid reducer and the cross slider 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, cross slider, and output flange;

[0031] Figure 7 Schematic diagram of the cycloid gear tooth profile using parabolic modification in the present invention.

[0032] The reference numerals in the figure are: 1-joint module housing, 2-exoskeleton oil seal, 3-cross roller bearing, 4-output flange, 5-spacer pinion housing, 6-cross slider conversion element, 7-cycloid wheel, 8-swing arm bearing, 9-needle roller, 10-input mechanism, 11-input support end, 12-motor stator, 13-motor rotor, 14-pinion housing, 15-motor driver and end cover assembly, 401-second guide mechanism, 601-rolling body, 701-first guide mechanism, 1101-third guide mechanism. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] In response to the above problems, the present application makes improvements and innovations and proposes the following embodiments.

[0039] In one embodiment, see Figure 1 、 Figure 2 、 Figure 3The present invention provides a built-in cycloid reducer and joint module of a cross slider output structure of a humanoid robot joint, comprising a motor and a cycloid reducer built into the motor, the two forming an integrated joint module; the cycloid reducer comprises an input mechanism (10), a cycloid wheel (7), a pinion housing (14) and an output mechanism 6; the input mechanism drives the cycloid wheel (7) to perform planetary motion relative to the pinion housing (14); the output mechanism 6 is used to convert the planetary motion of the cycloid wheel (7) into pure rotational motion and output it, and is characterized in that the output mechanism is a cross slider output structure (6).

[0040] The motor is an outer rotor frameless torque motor, and its annular stator (12) is mounted on the outer wall of the pin-tooth housing (14) of the cycloid reducer by static fit or screw fixation. The rotor (13) of the motor is directly fixed to the input end of the double eccentric crankshaft, which is the input component of the cycloid reducer.

[0041] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 The cycloid reducer has an input component which is a double eccentric crankshaft, with roller bearings or angular contact bearings at both ends supported in the center holes of the input support end (11) and the output flange (4). The two eccentric parts of the crankshaft have a phase angle difference of 180 degrees, and two cycloid wheels (7) are mounted on the crankshaft via a swing arm bearing (8). The two cycloid wheels (7) are arranged in a central symmetrical manner to balance the radial force.

[0042] In some embodiments, see Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 The pinion housing (14) is an annular part with a number of pinions (9) evenly distributed on its inner wall, forming an externally meshing pinion wheel. The outer tooth profile of the cycloid wheel (7) meshes with these pinions. The number of teeth zc of the cycloid wheel (7) is one less than the number of teeth zp of the pinions (9) (zp-zc=1), forming a small-tooth-difference planetary transmission.

[0043] The core of the present invention lies in its output mechanism. Figure 6 As shown, a pair of mutually parallel first chute grooves (701) are provided on the end surface of the cycloid wheel (7) facing the output end. A pair of mutually parallel second chute grooves (401) are also provided on the end surface of the output flange (4) facing the cycloid wheel. The extension direction of the second chute grooves is perpendicular to the extension direction of the first chute grooves.

[0044] In some embodiments, a cross-slider conversion element (6) is placed between the cycloid wheel (7) and the output flange (4). The element has two pairs of mutually perpendicular parallel outer surfaces, which respectively constitute a first sliding mechanism and a second sliding mechanism. The first sliding mechanism is embedded in a first sliding groove (701) of the cycloid wheel (7), and the second sliding mechanism is embedded in a second sliding groove (401) of the output flange (4). To reduce friction, needle rollers or rollers are arranged as rolling bodies (601) between the surface of the slider and the side wall of the sliding groove.

[0045] When the motor rotor drives the input crankshaft to rotate, the eccentric force causes the cycloid wheel (7) to perform planetary motion along the inner wall of the pinion housing (14), that is, it rotates around its own center and revolves around the center of the crankshaft. This composite motion of the cycloid wheel (7) is transmitted to the cross slider conversion element (6). Since the first sliding mechanism of the cross slider (6) can only translate in the first chute of the cycloid wheel (7), and its second sliding mechanism can only translate in the second chute of the output flange (4), these two mutually perpendicular motion constraints completely constrain and absorb the cycloid wheel's revolving motion. Only its rotational motion can be transmitted to the output flange (4) through the cross slider (6), thereby driving the output flange (4) to achieve pure, decelerated rotational motion.

[0046] The output flange (4) is the power output end of the entire joint module, and its outer edge is connected to the pinion housing (14) through a large-diameter thin-walled cross roller bearing (3). The cross roller bearing (3) can simultaneously withstand radial force, axial force and overturning moment, providing the joint with extremely high rigidity and load-bearing capacity.

[0047] In some embodiments, see Figure 7 The tooth profile of the cycloid wheel (7) adopts parabolic modification. The parabolic modification amount ΔL changes with the change of the distance between the meshing point and the node on the cycloid wheel tooth profile, so that the tooth profile is as close to the theoretical tooth profile as possible in the main working section. This modification method ensures that during the transmission process, multiple gear teeth can smoothly enter and exit the meshing, avoiding impact and interference, while optimizing the stress distribution in the contact area, thereby improving the transmission accuracy, efficiency and service life of the reducer.

[0048] In summary, the present invention has successfully developed a humanoid robot joint module with excellent performance through the compact integration of the motor and the reducer, as well as the innovative cross-slider output structure and the optimized tooth profile modification method, which effectively solves the various problems mentioned in the background technology.

[0049] 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 cross slider output structure with a built-in cycloid reducer and joint module, characterized by: The invention comprises a motor and a cycloid reducer built into the motor, and the two constitute an integrated joint module; the cycloid reducer comprises an input mechanism (10), a cycloid wheel (7), a pinion housing (14) and an output mechanism (6); the input mechanism drives the cycloid wheel (7) to perform planetary motion relative to the pinion housing (14); the output mechanism (6) is used to convert the planetary motion of the cycloid wheel (7) into pure rotational motion and output it, and is characterized in that the output mechanism is a cross slide output structure (6).

2. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 1, characterized in that: The motor is a frameless torque motor, the stator (12) of which is fixed to the outside of the pin-tooth housing (14), and the rotor (13) of which is fixed to the input mechanism (10) of the cycloid reducer.

3. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 1, characterized in that: The cross slider output structure comprises a cross slider conversion element (6), a first guide mechanism (701) provided on the cycloid wheel (7), a second guide mechanism (401) provided on the output flange (4), and a third guide mechanism (1101) on the input support end (11); the cross slider conversion element (6) has a first sliding mechanism and a second sliding mechanism perpendicular to each other; the first sliding mechanism is in sliding engagement with the first guide mechanism, the second sliding mechanism is in sliding engagement with the second guide mechanism, and the second sliding mechanism is in sliding engagement with the third guide mechanism.

4. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 3, characterized in that: The first guide mechanism is a first slide groove provided on the end face of the cycloid wheel (6), the second guide mechanism is a second slide groove provided on the end face of the output flange (4), the extension direction of the first slide groove and the extension direction of the second slide groove are perpendicular to each other, and the third guide mechanism is a third slide groove provided on the end face of the output support end (11), the extension direction of the first slide groove and the extension direction of the third slide groove are perpendicular to each other.

5. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 4, characterized in that: Rolling bodies (601) are provided between the first sliding mechanism and the first sliding groove of the cross slide conversion element (6), and between the second sliding mechanism and the second and third sliding grooves to form rolling friction pairs.

6. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 1, characterized in that: The cycloid reducer is a double cycloid wheel structure, comprising two cycloid wheels (7) arranged in a centrally symmetrical manner; the input mechanism is a double eccentric crankshaft (10); the two cycloid wheels (7) are respectively mounted on the two eccentric parts of the double eccentric crankshaft via swing arm bearings (8).

7. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 1, characterized in that: The output flange (4) is rotatably connected to the pin gear housing (14) via a cross roller bearing (3), and the cross roller bearing (3) simultaneously bears radial force, axial force and overturning moment.

8. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider output structure according to claim 1, characterized in that: The tooth profile of the cycloid wheel (7) adopts a parabolic shaping method.

9. The built-in cycloid reducer and joint module of the humanoid robot joint cross slider 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 cross slider output structure according to claim 8, characterized in that: The tooth profile equation of the cycloid wheel (7) 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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