A rotary joint actuator and its design method

Abstract

The present invention discloses a rotary joint actuator and its design method. One of the rotary joint actuators includes a fixed housing, which comprises a front cover and a rear cover. A frameless motor and a cam surface tooth planetary reducer are both arranged in the installation cavity reserved between the front cover and the rear cover; a driving device is connected to the frameless motor; the driving device includes a driving plate, an encoder is fixed on the driving plate, the driving plate is fixed inside a driving cover plate, and the driving cover plate is fixed outside the rear cover; the cam surface tooth planetary reducer includes: an input bearing, a planetary needle roller bearing, a planet carrier group, and a planetary gear group; the planetary gear group includes: a sun gear, a cam surface tooth planetary gear, and a tooth ring that is conjugated and meshed with the cam surface tooth planetary gear. The present invention discloses a rotary joint actuator and its design method. A rotary joint actuator has the characteristics of a compact structure, a large transmission ratio, high transmission accuracy, and good stability under the condition of controlling the size.

Description

Technical Field

[0001] The present invention relates to the field of rotary joints, and particularly to a rotary joint actuator and its design method. Background Art

[0002] Humanoid robots walk, crawl or run in complex environments by simulating human walking methods, and have strong adaptability and flexibility. Therefore, the joint actuators used in humanoid robots mainly meet the requirements of motion control of humanoid robots.

[0003] Therefore, the joint actuators used in humanoid robots mainly consider aspects such as high torque output, high transmission ratio, shock resistance, vibration resistance, self - adaptability, and compact design to meet the complex motion requirements and environmental adaptability of humanoid robots.

[0004] Currently, the rotary joint actuators used in humanoid robots mainly adopt traditional involute gear actuators, and the design of their transmission ratio is restricted by involute gears and cannot be further increased. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a rotary joint actuator and its design method, a rotary joint actuator for humanoid robots. The actuator has a compact structure and can have the characteristics of a large transmission ratio, high transmission accuracy, and good stability under the condition of controlling the size.

[0006] To achieve the above - mentioned purpose, the technical solution adopted by the present invention is: a frameless motor, which is used to provide driving force for a cam - surface - tooth planetary reducer; the cam - surface - tooth planetary reducer includes an input bearing, a planetary needle roller bearing, a planetary carrier group, and a planetary gear group; the flange is connected to the planetary carrier group through the input bearing, and the planetary gear group is connected to the planetary gear group through the planetary needle roller bearing; the planetary gear group includes a sun gear, a cam - surface - tooth planetary gear, and a tooth ring that is conjugated and meshed with the cam - surface - tooth planetary gear; the sun gear meshes with the cam - surface - tooth planetary gear and is fixedly connected to the flange, and the tooth ring is coaxially arranged in the stop collar through a first output bearing and a second output bearing, and the cam - surface - tooth planetary gear is connected to the planetary gear group through the planetary needle roller bearing.

[0007] In a preferred embodiment of the present invention, the planetary carrier group includes a first planetary carrier and a second planetary carrier, the planetary needle roller bearings are respectively connected to the first planetary carrier and the second planetary carrier, and the cam - surface - tooth planetary gear is respectively connected to the first planetary carrier and the second planetary carrier through the planetary needle roller bearings.

[0008] In a preferred embodiment of the present invention, the fixed housing includes a front cover and a rear cover. There is an installation cavity reserved between the front cover and the rear cover, and the frameless motor and the cam surface tooth planetary reducer are both arranged in the installation cavity; the driving device includes a driving plate, an encoder and a driving cover plate. The driving cover plate is fixed to the outside of the rear cover, the driving plate is fixed inside the driving cover plate, and an encoder is fixedly arranged on the driving plate;

[0009] And / or, the sun gear and the curved surface tooth planetary gear form an external meshing spur gear drive;

[0010] And / or, the curved surface tooth planetary gear and the ring gear form an internal meshing spur gear drive.

[0011] In a preferred embodiment of the present invention, the tooth surface of the sun gear is formed by a cam curve and the tooth surface formation function of the sun gear to obtain the tooth surface equation of the sun gear;

[0012] The tooth surface of the curved surface tooth planetary gear is composed of a spline curve conjugate to the cam curve formed according to the relative motion relationship by the cam curve, and the tooth surface formation function of the curved surface tooth planetary gear to obtain the tooth surface equation of the curved surface tooth planetary gear;

[0013] The tooth surface of the ring gear is composed of a conjugate curve formed by the spline curve of the curved surface tooth planetary gear according to the relative motion relationship, and the tooth surface formation function of the ring gear to obtain the tooth surface equation of the ring gear;

[0014] The tooth profiles of the ring gear, the curved surface tooth planetary gear and the sun gear perform meshing motion according to the gear transmission ratio relationship to form a conjugate meshing tooth profile of the ring gear, the curved surface tooth planetary gear and the sun gear.

[0015] In a preferred embodiment of the present invention, the tooth surface equation of the sun gear is:

[0016] ;

[0017] Wherein, is the eccentricity of the sun gear, is the base circle radius of the sun gear, is the tooth profile angle parameter of the sun gear, p is the tooth thickness change parameter of each gear in the planetary gear set, is the tooth surface form change parameter function in the tooth profile direction of each gear in the planetary gear set, is the tooth surface form change parameter function in the tooth thickness direction of each gear in the planetary gear set, is the tooth surface form change parameter of each gear in the planetary gear set.

[0018] In a preferred embodiment of the present invention, the tooth surface equation of the curved surface tooth planetary gear is:

[0019] ;

[0020] Among them, is the center distance between the sun gear and the curved-tooth planetary gear, represents the rotation angle of the coordinate where the sun gear is located, represents the rotation angle of the coordinate where the curved-tooth planetary gear is located, is the number of teeth of the sun gear, is the number of teeth of the curved-tooth planetary gear, is the tooth number ratio between the curved-tooth planetary gear and the sun gear, as well as the transmission ratio between the curved-tooth planetary gear and the sun gear, is the base circle radius of the curved-tooth planetary gear.

[0021] In a preferred embodiment of the present invention, the tooth surface equation of the ring gear is:

[0022] ;

[0023] Among them, is the number of teeth of the ring gear, is the tooth number ratio between the ring gear and the curved-tooth planetary gear, and the transmission ratio between the ring gear and the curved-tooth planetary gear, represents the rotation angle of the coordinate where the curved-tooth planetary gear is located, represents the rotation angle of the coordinate where the ring gear is located, is the base circle radius of the ring gear, is the radius of the center circle of the needle bearing of the ring gear.

[0024] In a preferred embodiment of the present invention, the tooth surfaces of the sun gear, the curved-tooth planetary gear, and the ring gear are conical tooth surfaces; the tooth surface of the curved-tooth planetary gear is a bilaterally symmetric double conical tooth surface; the tooth surface of the sun gear is a single conical tooth surface, and it meshes with only one side tooth surface of the curved-tooth planetary gear; the tooth surface of the ring gear is a single conical tooth surface, and it meshes with only the other side tooth surface of the conical surface planetary gear; among them, the tooth thickness change parameter , B is the tooth surface thickness of the sun gear; in the tooth profile direction of the conical tooth surface gear, the tooth surface shape change parameter function , where represents the inclination angle of the conical tooth surface; in the tooth thickness direction of the conical tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameter of the conical tooth surface gear ;

[0025] And / or, the tooth surfaces of the sun gear, the curved-tooth planetary gear, and the ring gear are arc tooth surfaces; the tooth surface of the curved-tooth planetary gear is a bilaterally symmetric double arc tooth surface; the tooth surface of the sun gear is a single arc tooth surface that meshes with only one side of the tooth surface of the curved-tooth planetary gear; the tooth surface of the ring gear is a single arc tooth surface, and it meshes with only the other side tooth surface of the curved-tooth planetary gear; among them, the tooth thickness change parameter of the arc tooth surface gear , B is the thickness of the sun gear tooth surface; in the tooth profile direction of the circular arc tooth surface gear, the tooth surface morphology change parameter function ; Parameter function of tooth surface morphology change in the tooth thickness direction of circular arc tooth surface gear ; Tooth surface morphology change parameters of circular arc tooth surface gear ;

[0026] And / or, the tooth surfaces of the sun gear, the curved tooth planetary gear and the ring gear are straight tooth surfaces; wherein the tooth thickness variation parameter of the straight tooth surface gear is , B is the thickness of the sun gear tooth surface; in the tooth profile direction of the spur gear, the tooth surface morphology change parameter function ; Parameter function of tooth surface morphology change in the tooth thickness direction of spur gear ; Tooth surface morphology change parameters of spur gears ; and the sun gear and the curved tooth planet gear form an external meshing spur gear transmission, and the curved tooth planet gear and the ring gear form an internal meshing spur gear transmission.

[0027] In a preferred embodiment of the present invention, the number of teeth of the ring gear is , and the number N of curved-tooth planetary gears can be Whether the formula is an integer is determined, the transmission ratio of the planetary gear set is and / or, the tooth surfaces of the sun gear, the curved-tooth planetary gear, and the ring gear and the tooth surface forming function include straight lines, oblique lines, circular arcs, parabolas, or spline curves; and / or, .

[0028] In a preferred embodiment of the present invention, the curved surface gear planetary gear is divided into two layers, and each layer is evenly distributed with three curved surface gear planetary gears; , wherein the axis of the relative position curved surface gear planetary gear is set at a phase offset of 180° around the revolution center of the curved surface gear planetary gear;

[0029] Or, the curved surface planetary gears are divided into two layers, and each layer is evenly distributed with 3 curved surface planetary gears, that is , wherein the curved surface gear planetary gears in relative positions are arranged in a coaxial connection and staggered on the coaxial line phase;

[0030] Alternatively, the gear ring is provided with two layers, and is respectively meshed with the two layers of curved surface planetary gears through gear ring needle roller bearings, and the number of gear ring needle roller bearings is the same as the number of teeth of the corresponding gear ring.

[0031] In a preferred embodiment of the present invention, a design method for a rotary joint actuator is implemented using a rotary joint actuator.

[0032] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0033] A rotary joint actuator of the present invention and its design method. The present invention is a cam curve planetary rotary joint actuator for a humanoid robot. The actuator has a compact structure and can have advantages such as a large transmission ratio, high transmission accuracy, and good stability under the condition of controlling the size. It has a large transmission ratio on the basis of high torque, high stiffness, and impact resistance.

[0034] The rotary joint actuator of the present invention consists of a fixed housing, a driving device, a frameless motor, and a cam surface tooth planetary reducer. The cam surface tooth planetary reducer is a cam surface tooth planetary reducer with a compact structure, which can obtain a large transmission ratio and high transmission accuracy under the condition of controlling the size. Moreover, the number of teeth of the sun gear is only [X], which can avoid the phenomenon of root cutting and is convenient for processing. The tooth height of the gear teeth is small and the tooth root width is large, having good tooth root bending strength and tooth surface contact strength, and a large load-bearing capacity. Brief Description of the Drawings

[0035] The present invention will be further described below in conjunction with the drawings and embodiments.

[0036] Figure 1 It is a three-dimensional structure schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention;

[0037] Figure 2 It is a three-dimensional sectional view of a rotary joint actuator according to a preferred embodiment of the present invention;

[0038] Figure 3 It is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ;

[0039] Figure 4 It is an embodiment schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ;

[0040] Figure 5 It is a schematic diagram of the gear tooth surface according to a preferred embodiment of the present invention Figure 1 ;

[0041] Figure 6 It is a schematic diagram of the gear tooth surface according to a preferred embodiment of the present invention Figure 2 ;

[0042] Figure 7 It is a schematic diagram of the gear tooth surface according to a preferred embodiment of the present invention Figure 3 ;

[0043] Figure 8 It is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 2 ;

[0044] Figure 9 It is an embodiment schematic diagram of a rotary joint actuator according to a preferred embodiment of the present inventionFigure 2 ;

[0045] Figure 10 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 3 ;

[0046] Figure 11 is a schematic diagram of an embodiment of a rotary joint actuator according to a preferred embodiment of the present invention Figure 3 ;

[0047] Figure 12 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 4 ;

[0048] Figure 13 is a schematic diagram of an embodiment of a rotary joint actuator according to a preferred embodiment of the present invention Figure 4 ;

[0049] Figure 14 is the explosion of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ;

[0050] Figure 15 is the explosion of a rotary joint actuator according to a preferred embodiment of the present invention Figure 2 ;

[0051] In the figure: 100, fixed housing; 200, frameless motor; 300, cam surface tooth planetary reducer; 400, drive device; 1, drive cover plate; 2, rear cover; 3, drive plate; 4, rotor; 5, first planet carrier; 6, encoder; 7, magnet; 8, flange; 9, first bearing; 10, input bearing; 11, spigot support; 12, second planet carrier; 13, planetary gear set; 14, planetary needle roller bearing; 15, first output bearing; 16, stator; 17, second output bearing; 18, front cover; 19, ring gear; 20, surface tooth planetary gear; 21, second layer surface tooth planetary gear; 22, sun gear; 23, ring gear needle roller bearing; 22a, tapered tooth surface sun gear; 20a, tapered tooth surface surface tooth planetary gear; 19a, tapered tooth surface ring gear; 22b, arc tooth surface sun gear; 20b, arc tooth surface surface tooth planetary gear; 19b, arc tooth surface ring gear; 22c, straight tooth surface sun gear; 20c, straight tooth surface surface tooth planetary gear; 19c, straight tooth surface ring gear. Detailed implementation manners

[0052] Now, the present invention will be further described in detail with reference to the drawings and embodiments. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0053] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Embodiment 1

[0054] As Figure 1 , Figure 2 , Figure 14 , Figure 15 shown, a rotary joint actuator includes a fixed housing 100, a frameless motor 200 and a cam surface gear planetary reducer 300 disposed in the fixed housing 100, and a driving device 400 connected to the frameless motor 200; the fixed housing 100 includes a front cover 18 and a rear cover 2, and an installation cavity is reserved between the front cover 18 and the rear cover 2, and both the frameless motor 200 and the cam surface gear planetary reducer 300 are disposed in the installation cavity; the driving device 400 includes a driving plate 3, an encoder 6 and a driving cover plate 1, the driving cover plate 1 is fixed to the outside of the rear cover 2, the driving plate 3 is fixed inside the driving cover plate 1, and an encoder 6 is fixedly disposed on the driving plate 3; the frameless motor 200 is connected to the cam surface gear planetary reducer 300; the driving device 400 is used to control the frameless motor 200, and the frameless motor 200 is used to provide driving force for the cam surface gear planetary reducer 300. The frameless motor 200 includes a stator 16, a rotor 4 and a magnet 7 disposed in the fixed housing 100, and the rotor 4 is fixedly connected to a flange 8. The driving device 400 is responsible for providing motor control for the rotary joint actuator; the frameless motor 200 is used to provide driving force for the rotary joint actuator; the cam surface gear planetary reducer 300 can have a high reduction ratio under the condition of a fixed size and is fixed inside the fixed housing 100.

[0055] Specifically, the cam surface tooth planetary reducer 300 includes an input bearing 10, a planetary needle bearing 14, a planetary carrier group, and a planetary gear group 13; the flange 8 is respectively connected to the first planetary carrier 5 and the rear cover 2 through the input bearing 10 and the first bearing 9, and the planetary gear group 13 is connected to the planetary gear group 13 through the planetary needle bearing 14; the planetary gear group 13 includes a sun gear 22, a cam surface tooth planetary gear 20, and a tooth ring 19 that is conjugate meshed with the cam surface tooth planetary gear 20; the sun gear 22 meshes with the cam surface tooth planetary gear 20 and is fixedly connected to the flange 8, the tooth ring 19 is coaxially arranged in the stop collar 11 through the first output bearing 15 and the second output bearing 17, and the cam surface tooth planetary gear 20 is connected to the planetary gear group 13 through the planetary needle bearing 14.

[0056] Further, the planetary carrier group includes a first planetary carrier 5 and a second planetary carrier 12. The planetary needle bearings 14 are respectively connected to the first planetary carrier 5 and the second planetary carrier 12, and the cam surface tooth planetary gears 20 are respectively connected to the first planetary carrier 5 and the second planetary carrier 12 through the planetary needle bearings 14. The sun gear 22 and the cam surface tooth planetary gear 20 form an external meshing spur gear drive; the cam surface tooth planetary gear 20 and the tooth ring 19 form an internal meshing spur gear drive. That is, the planetary gear group 13 includes a sun gear 22, a plurality of cam surface tooth planetary gears 20, and a tooth ring 19; the plurality of cam surface tooth planetary gears 20 are arranged in a ring around the sun gear 22, and the outer periphery of the sun gear 22 meshes with the cam surface tooth planetary gears 20; the cam surface tooth planetary gears 20 are located inside the tooth ring 19, and the tooth ring 19 is conjugate meshed with the cam surface tooth planetary gears 20.

[0057] Further, the tooth profile of the sun gear 22 is a cam curve, the tooth profile of the cam surface tooth planetary gear 20 is a spline curve conjugate to the cam curve formed according to the relative motion relationship, and the tooth profile of the tooth ring 19 is a conjugate curve formed according to the relative motion relationship of a cam curve; the tooth profiles of the tooth ring 19, the cam surface tooth planetary gear 20, and the sun gear 22 perform meshing motion according to the gear transmission ratio relationship, constituting the conjugate meshing tooth profiles of the tooth ring 19, the cam surface tooth planetary gear 20, and the sun gear 22. Embodiment 2

[0058] As Figure 1 shown, on the basis of Embodiment 1, a rotary joint actuator includes: a fixed housing 100, a driving device 400, a frameless motor 200, and a cam surface tooth planetary reducer 300. Specifically, the driving device 400 is responsible for providing motor control for the rotary joint actuator; the frameless motor 200 is used to provide driving force for the rotary joint actuator; the cam surface tooth planetary reducer 300 is a cam surface tooth planetary reducer, which can have a high reduction ratio under the condition of a fixed size and is fixed inside the fixed housing 100.

[0059] As Figure 1 、 Figure 2As shown in the figure, the fixed housing 100 includes a rear cover 2 and a front cover 18. The rear cover 2 and the front cover 18 are fixedly connected by screws. The frameless motor 200 and the cam surface tooth planetary reducer 300 are both arranged inside the fixed housing 100. The driving device 400 includes a driving cover plate 1, a driving plate 3, an encoder 6 and a magnet 7. The encoder 6 is fixed on the driving plate 3 and is coaxial with the flange 8. The driving plate 3 is fixed inside the driving cover plate 1. Moreover, the driving cover plate 1 is fixed on the outside of the rear cover 2. The magnet 7 is arranged coaxially with the encoder 6 and the flange 8 and is fixed inside the flange 8. The frameless motor 200 includes a rotor 4 and a stator 16. The rotor 4 is fixedly connected coaxially with the flange 8. The stator 16 is connected to the cam surface tooth planetary reducer 300 through a rabbet bracket 11. The cam surface tooth planetary reducer 300 includes a first planet carrier 5, an input bearing 10, a second planet carrier 12, a planetary gear set 13, and a planetary needle roller bearing 14. The first planet carrier 5 is connected coaxially with the flange 8 through the input bearing 10. The first planet carrier 5 is connected to the rabbet bracket 11 and the planetary gear set 13 through a first output bearing 15. The second planet carrier 12 is connected to the front cover 18 and is connected to the planetary gear set 13 through a second output bearing 17. The first planet carrier 5 and the second planet carrier 12 are fixedly connected to each other.

[0060] As Figure 2 , Figure 3 shown in the figure, in the cam surface tooth planetary reducer 300, the planetary gear set 13 includes a tooth ring 19, a surface tooth planetary gear 20 and a sun gear 22 whose tooth profiles are conjugate meshed. The tooth profile of the sun gear 22 is a section of cam curve. The tooth profile of the surface tooth planetary gear 20 is a spline curve conjugate to the cam curve formed according to the relative motion relationship. The tooth profile of the tooth ring 19 is a conjugate curve formed according to the relative motion relationship of this section of curve. The tooth profiles of the three gears perform meshing motion according to a quantitative relationship, forming the conjugate meshed tooth profiles of the three gears.

[0061] Specifically, the tooth profile equation of the sun gear 22 is:

[0062] ;

[0063] where is the eccentricity of the sun gear 22, is the base circle radius of the sun gear 22, is the tooth profile angle parameter of the sun gear 22, p is the tooth thickness change parameter of each gear in the planetary gear set, is the tooth surface form change parameter function in the tooth profile direction of each gear in the planetary gear set, is the tooth surface form change parameter function in the tooth thickness direction of each gear in the planetary gear set, is the tooth surface form change parameter of each gear in the planetary gear set. is the number of teeth of the sun gear 22.

[0064] Specifically, the tooth surface equation of the curved-tooth planet gear 20 is:

[0065] ;

[0066] wherein, is the center distance between the sun gear 22 and the curved-tooth planet gear 20, represents the rotation angle of the coordinate where the sun gear 22 is located, represents the rotation angle of the coordinate where the curved-tooth planet gear 20 is located, is the number of teeth of the sun gear 22, is the number of teeth of the curved-tooth planet gear 20, is the tooth number ratio of the curved-tooth planet gear 20 to the sun gear 22, and the transmission ratio of the curved-tooth planet gear 20 to the sun gear 22, is the base circle radius of the curved-tooth planet gear 20.

[0067] Specifically, the tooth surface equation of the ring gear 19 is:

[0068] ;

[0069] wherein, is the number of teeth of the ring gear 19, is the tooth number ratio of the ring gear 19 to the curved-tooth planet gear 20, represents the rotation angle of the coordinate where the curved-tooth planet gear 20 is located, represents the rotation angle of the coordinate where the ring gear 19 is located, is the base circle radius of the ring gear 19, is the radius of the center circle of the needle roller bearing 23 of the ring gear.

[0070] In some of the embodiments, the number of teeth of the ring gear 19 or the number of needle roller bearings 23 of the ring gear is , and the number of curved-tooth planet gears 20 can be determined by whether the formula is an integer. Specifically, the transmission ratio of the planetary gear set 13 is . The sun gear 22 and the curved-tooth planet gear 20 form an external meshing spur gear transmission. The curved-tooth planet gear 20 and the ring gear 19 form an internal meshing spur gear transmission. Moreover, the tooth surfaces and tooth surface formation functions of the sun gear 22, the curved-tooth planet gear 20, and the ring gear 19 are not limited to straight lines, oblique lines, arcs, parabolas, or other spline curves. Embodiment Three

[0071] Based on Embodiment Two, as Figure 5 shown, the tooth surfaces of the sun gear 22, the curved-tooth planet gear 20, and the ring gear 19 are conical tooth surfaces; respectively, as Figure 5The conical tooth surface curved tooth planet gear 20a, conical tooth surface sun gear 22a, and conical tooth surface ring gear 19a shown in

[0072] Specifically, the curved tooth planet gear 20 uses the conical tooth surface curved tooth planet gear 20a as shown in <() Figure 5 The tooth surface of the conical tooth surface curved tooth planet gear 20a is a left - right symmetric double - conical tooth surface; the sun gear 22 uses the conical tooth surface sun gear 22a as shown in Figure 5 The tooth surface of the conical tooth surface sun gear 22a is a single - conical tooth surface and meshes only with one side tooth surface of the conical tooth surface curved tooth planet gear 20a; the ring gear 19 uses the conical tooth surface ring gear 19a as shown in Figure 5 The tooth surface of the conical tooth surface ring gear 19a is a single - conical tooth surface and meshes only with the other side tooth surface of the conical tooth surface curved tooth planet gear 20a.

[0073] Among them, the tooth surface tooth thickness change parameter of the conical tooth surface gear , B is the tooth surface thickness of the conical tooth surface sun gear 22a; in the tooth profile direction of the conical tooth surface gear, the tooth surface shape change parameter function , where represents the inclination angle of the conical tooth surface; in the tooth thickness direction of the conical tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameter of the conical tooth surface gear . Example Four

[0074] Based on Example Two, as shown in Figure 6 , the tooth surfaces of the sun gear 22, curved tooth planet gear 20, and ring gear 19 are arc tooth surfaces; respectively use the arc tooth surface curved tooth planet gear 20b, arc tooth surface sun gear 22b, and arc tooth surface ring gear 19b shown in Figure 6 . <()

[0075] Specifically, the curved tooth planet gear 20 uses the arc tooth surface curved tooth planet gear 20b as shown in Figure 6 The tooth surface of the arc tooth surface curved tooth planet gear 20b is a left - right symmetric arc tooth surface; the sun gear 22 uses the arc tooth surface sun gear 22b as shown in Figure 6 The tooth surface of the arc tooth surface sun gear 22b is a single - arc tooth surface and meshes only with one side tooth surface of the arc tooth surface curved tooth planet gear 20b; the ring gear 19 uses the arc tooth surface ring gear 19b as shown in Figure 6 The tooth surface of the arc tooth surface ring gear 19b is a single - arc tooth surface and meshes only with the other side tooth surface of the arc tooth surface curved tooth planet gear 20b.

[0076] Among them, the tooth thickness change parameter of the arc tooth surface gear It should be noted that there may be some inaccuracies in the translation due to the lack of specific context for the tags and some unclear expressions in the original text. If possible, more detailed information about the text content would be helpful for a more accurate translation., B is the tooth surface thickness of the arc tooth surface sun gear 22b; in the tooth profile direction of the arc tooth surface gear, the tooth surface shape change parameter function ; in the tooth thickness direction of the arc tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameters of the arc tooth surface gear . Embodiment Five

[0077] On the basis of Embodiment Two, as Figure 7 shown, the tooth surfaces of the sun gear 22, the curved tooth planet gear 20 and the ring gear 19 are straight tooth surfaces; respectively as Figure 7 shown, the straight tooth surface curved tooth planet gear 20c, the straight tooth surface sun gear 22c, and the straight tooth surface ring gear 19c.

[0078] The tooth surfaces of the straight tooth surface sun gear 22c, the straight tooth surface curved tooth planet gear 20c and the straight tooth surface ring gear 19c are all straight tooth surfaces. Among them, the tooth thickness change parameter of the straight tooth surface gear , B is the tooth surface thickness of the straight tooth surface sun gear 22c; in the tooth profile direction of the straight tooth surface gear, the tooth surface shape change parameter function ; in the tooth thickness direction of the straight tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameters of the straight tooth surface gear . And an external meshing spur gear drive is formed between the straight tooth surface sun gear 22c and the straight tooth surface curved tooth planet gear 20c, and an internal meshing spur gear drive is formed between the straight tooth surface curved tooth planet gear 20c and the straight tooth surface ring gear 19c. Embodiment Six

[0079] On the basis of any one of Embodiments Two to Five, as Figure 3 , Figure 4 shown, the curved tooth planet gear 20 is divided into two layers, and each layer is evenly distributed with 3 curved tooth planet gears 20, that is , where the axes of the relatively positioned curved tooth planet gears 20 are arranged at a phase difference of 180° around the revolution center of the curved tooth planet gear 20.

[0080] Specifically, the arrangement of the planetary gear set 13 is as Figure 3As shown. Planetary needle roller bearings 14 are connected to the first planet carrier 5 and the second planet carrier 12, respectively. The planetary gear set 13 is provided with two layers, including a ring gear 19, a curved-tooth planetary gear 20, a second layer of curved-tooth planetary gear 21, and a sun gear 22. The curved-tooth planetary gear 20 and the second layer of curved-tooth planetary gear 21 each have three curved-tooth planetary gears evenly distributed. The axes of the curved-tooth planetary gears are arranged at a phase difference of 180° around the orbital center of the curved-tooth planetary gears and are connected to the planetary needle roller bearings 14. The ring gear 19 is provided with two layers of internal gears that mesh with the curved-tooth planetary gears 20 and the second layer of curved-tooth planetary gears 21, and is fixedly connected to the stop frame 11. The sun gear 22 is coaxially connected to the flange 8. Its gear portion is composed of two cam gears that are offset by 180° and mesh with the curved-tooth planetary gears 20 and the second layer of curved-tooth planetary gears 21, respectively. Example 7

[0081] Based on any one of the embodiments from the second embodiment to the fifth embodiment, Figure 8 、 Figure 9 As shown, the curved surface gear planetary gear 20 is divided into two layers, and each layer is evenly distributed with three curved surface gear planetary gears 20, namely , wherein the relatively positioned curved planetary gears 20 are arranged in a coaxial connection and staggered on the coaxial line Phase.

[0082] Specifically, the arrangement of the planetary gear set 13 is as follows: Figure 8 As shown. Planetary needle roller bearings 14 are connected to the second planet carrier 12; the planetary gear set 13 is provided with two layers, including a ring gear 19, a curved surface gear planetary gear 20, a second layer of curved surface gear planetary gear 21, and a sun gear 22; the curved surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21 are each evenly distributed with three curved surface gear planetary gears, wherein the curved surface gear planetary gears 20 in relative positions are arranged in a coaxial connection and staggered on the coaxial axis. Phase ( is the number of teeth of the curved-tooth planetary gear), and is connected to the planetary needle roller bearing 14; the ring gear 19 is provided with two layers of internal gears meshing with the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21, and is fixedly connected to the stop frame 11; the sun gear 22 is coaxially connected to the flange 8, and its gear part is two cam curve gears staggered by 180°, and meshes with the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21 respectively. Example 8

[0083] Based on any one of the embodiments from the second embodiment to the fifth embodiment, Figure 10 、 Figure 11 As shown, the gear ring 19 is provided with two layers of gear ring needle roller bearings 23 respectively meshing with two layers of curved surface gear planetary gears 20, and the number of gear ring needle roller bearings 23 is the same as the number of teeth of the corresponding gear ring.

[0084] Specifically, the arrangement of the planetary gear set 13 is as follows: Figure 10 As shown, the planetary needle roller bearings 14 are connected to the first planet carrier 5 and the second planet carrier 12, respectively. The planetary gear set 13 is provided with two layers, including a ring gear 19, curved-tooth planetary gears 20, a second layer of curved-tooth planetary gears 21, and a sun gear 22. The curved-tooth planetary gears 20 and the second layer of curved-tooth planetary gears 21 each have three curved-tooth planetary gears, with the axes of the curved-tooth planetary gears being arranged at a phase difference of 180° around the orbital center of the curved-tooth planetary gears and connected to the planetary needle roller bearings 14. The ring gear 19 is fixedly connected to the stop frame 11 and is provided with two layers of ring gear needle roller bearings 23 that mesh with the curved-tooth planetary gears 20 and the second layer of curved-tooth planetary gears 21, respectively. The number of ring gear needle roller bearings 23 is equal to the number of teeth on the corresponding ring gear 19. The sun gear 22 is connected to the flange 8. Its gear portion comprises two cam gears that are offset by 180° and mesh with the first layer of curved-tooth planetary gears 20 and the second layer of curved-tooth planetary gears 21, respectively. Embodiment 9

[0085] On the basis of any one of the embodiments 2 to 5, the arrangement of the planetary gear set 13 is as follows: Figure 12 、 Figure 13 As shown. Figure 12 、 Figure 13 As shown, the gear ring 19 is provided with two layers of gear ring needle roller bearings 23 respectively meshing with two layers of curved surface gear planetary gears 20, and the number of gear ring needle roller bearings 23 is the same as the number of teeth of the corresponding gear ring.

[0086] Specifically, the arrangement of the planetary gear set 13 is as follows: Figure 12 As shown. Planetary needle roller bearings 14 are connected to the first planet carrier 5; the planetary gear set 13 is provided with two layers, including a ring gear 19, a curved surface gear planetary gear 20, a second layer of curved surface gear planetary gear 21, and a sun gear 22; the curved surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21 are each evenly distributed with three curved surface gear planetary gears, wherein the curved surface gear planetary gears in relative positions are arranged in a coaxial connection and staggered on the coaxial axis. Phase ( is the number of teeth of the curved-tooth planetary gear), and is connected to the planetary needle roller bearing 14; the ring gear 19 is fixedly connected to the stop frame 11, and is provided with two layers of ring gear needle roller bearings 23 respectively meshing with the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21. The number of ring gear needle roller bearings 23 is equal to the number of teeth of the corresponding ring gear 19; the sun gear 22 is connected to the flange 8, and its gear part is two cam curve gears staggered by 180°, and meshing with the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21 respectively. Example 10

[0087] Based on the second embodiment, is the number of teeth of the sun gear 22, and . Embodiment XI

[0088] A design method of a rotary joint actuator is realized by using a rotary joint actuator in any one of Embodiments 1 to 9.

[0089] Working principle:

[0090] A rotary joint actuator and its design method of the present invention, a cam curve planetary rotary joint actuator for a humanoid robot. The actuator has a compact structure and can have advantages such as a large transmission ratio, high transmission accuracy, and good stability under the condition of controlling the size. On the basis of high torque, high stiffness, and impact resistance, the transmission ratio is increased. A rotary joint actuator of the present invention is composed of a fixed housing, a driving device, a frameless motor, and a cam surface tooth planetary reducer. It has a compact structure and can obtain a large transmission ratio and high transmission accuracy under the condition of controlling the size. Moreover, the number of teeth of the sun gear is only 1, which can avoid the phenomenon of undercutting and is convenient for processing. The tooth height of the gear teeth is small and the tooth root width is large, having good tooth root bending strength and tooth surface contact strength and large load-bearing capacity.

[0091] The above specific embodiments are specific supports for the proposed solution idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any equivalent change or equivalent modification made on the basis of the technical solution of the present invention in accordance with the technical idea proposed by the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A rotary joint actuator, characterized in that: It includes a fixed housing, and a frameless motor, a cam surface tooth planetary reducer and a driving device arranged inside the fixed housing; the frameless motor is connected to the driving device; the frameless motor is connected to the cam surface tooth planetary reducer; the driving device is used to control the frameless motor, and the frameless motor is used to provide driving force for the cam surface tooth planetary reducer; The cam surface tooth planetary reducer includes an input bearing, a planetary needle bearing, a planetary carrier group, and a planetary gear group; the flange is connected to the planetary carrier group through the input bearing, and the planetary gear group is connected to the planetary gear group through the planetary needle bearing; The planetary gear group includes a sun gear, a surface tooth planetary gear, and a tooth ring that is conjugate meshed with the surface tooth planetary gear; the sun gear meshes with the surface tooth planetary gear and is fixedly connected to the flange, the tooth ring is coaxially arranged inside the stop collar through a first output bearing and a second output bearing, and the surface tooth planetary gear is connected to the planetary gear group through a planetary needle bearing; The tooth surface of the sun gear is formed by a cam curve and a function of the tooth surface of the sun gear to obtain the tooth surface equation of the sun gear; The tooth surface of the surface tooth planetary gear is composed of a spline curve conjugate to the cam curve formed by the cam curve according to the relative motion relationship, and a function of the tooth surface of the surface tooth planetary gear to obtain the tooth surface equation of the surface tooth planetary gear; The tooth surface of the tooth ring is composed of a conjugate curve formed by the spline curve of the surface tooth planetary gear according to the relative motion relationship, and a function of the tooth surface of the tooth ring to obtain the tooth surface equation of the tooth ring; The tooth profiles of the tooth ring, the surface tooth planetary gear and the sun gear perform meshing motion according to the gear transmission ratio relationship to form the conjugate meshing tooth profiles of the tooth ring, the surface tooth planetary gear and the sun gear; The tooth surfaces of the sun gear, the curved-tooth planet gear and the ring gear are conical tooth surfaces; the tooth surface of the curved-tooth planet gear is a bilaterally symmetric double conical tooth surface; the tooth surface of the sun gear is a single conical tooth surface and meshes only with one side tooth surface of the curved-tooth planet gear; the tooth surface of the ring gear is a single conical tooth surface and meshes only with the other side tooth surface of the conical curved-tooth planet gear; wherein, the tooth thickness change parameter of the conical tooth surface gear , B is the tooth surface thickness of the sun gear; in the tooth profile direction of the conical tooth surface gear, the tooth surface shape change parameter function , where represents the inclination angle of the conical tooth surface; in the tooth thickness direction of the conical tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameter of the conical tooth surface gear ; And / or, the tooth surfaces of the sun gear, the curved-tooth planet gear, and the ring gear are arc tooth surfaces; the tooth surface of the curved-tooth planet gear is a bilaterally symmetric double-arc tooth surface; the tooth surface of the sun gear is a single-arc tooth surface that meshes only with one side tooth surface of the curved-tooth planet gear; the tooth surface of the ring gear is a single-arc tooth surface and meshes only with the other side tooth surface of the curved-tooth planet gear; wherein, the tooth thickness change parameter of the arc tooth surface gear , B is the tooth surface thickness of the sun gear; in the tooth profile direction of the arc tooth surface gear, the tooth surface shape change parameter function ; in the tooth thickness direction of the arc tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameter of the arc tooth surface gear ; And / or, the tooth surfaces of the sun gear, the curved-tooth planet gear and the ring gear are straight tooth surfaces; wherein, the tooth thickness change parameter of the straight tooth surface gear , B is the tooth surface thickness of the sun gear; in the tooth profile direction of the straight tooth surface gear, the tooth surface shape change parameter function ; in the tooth thickness direction of the straight tooth surface gear, the tooth surface shape change parameter function ; the tooth surface shape change parameter of the straight tooth surface gear ; and an external meshing straight gear drive is formed between the sun gear and the curved-tooth planet gear, and an internal meshing straight gear drive is formed between the curved-tooth planet gear and the ring gear.

2. The rotary joint actuator according to claim 1, wherein: The fixed housing includes a front cover and a rear cover, and an installation cavity is reserved between the front cover and the rear cover. The frameless motor and the cam surface tooth planetary reducer are both arranged in the installation cavity; the driving device includes a driving board, an encoder and a driving cover plate. The driving cover plate is fixed outside the rear cover, the driving board is fixed inside the driving cover plate, and the encoder is fixedly arranged on the driving board; And / or, the sun gear and the surface tooth planetary gear form an external meshing spur gear transmission; And / or, the surface tooth planetary gear and the tooth ring form an internal meshing spur gear transmission; And / or, the planetary carrier group includes a first planetary carrier and a second planetary carrier. The planetary needle bearings are respectively connected to the first planetary carrier and the second planetary carrier, and the surface tooth planetary gear is connected to the first planetary carrier and the second planetary carrier through the planetary needle bearings respectively.

3. The rotary joint actuator according to claim 2, characterized in that: The tooth surface equation of the sun gear is: ； Among them, is the eccentricity of the sun gear, is the base circle radius of the sun gear, is the tooth profile angle parameter of the sun gear, and p is the tooth thickness change parameter of each gear in the planetary gear set, is the tooth surface morphology change parameter function in the tooth profile direction of each gear in the planetary gear set, is the tooth surface morphology change parameter function in the tooth thickness direction of each gear in the planetary gear set, is the tooth surface morphology change parameter of each gear in the planetary gear set.

4. The rotary joint actuator according to claim 3, wherein, The tooth surface equation of the surface tooth planetary gear is: ； Among them, is the center distance between the sun gear and the curved-tooth planetary gear, represents the rotation angle of the coordinate where the sun gear is located, represents the rotation angle of the coordinate where the curved-tooth planetary gear is located, is the number of teeth of the sun gear, is the number of teeth of the curved-tooth planetary gear, is the tooth number ratio between the curved-tooth planetary gear and the sun gear, as well as the transmission ratio between the curved-tooth planetary gear and the sun gear, is the base circle radius of the curved-tooth planetary gear.

5. The rotary joint actuator according to claim 4, characterized in that: The tooth surface equation of the tooth ring is: ； Among them, is the number of teeth of the ring gear, is the tooth number ratio of the ring gear to the curved-tooth planetary gear, that is, the transmission ratio of the ring gear to the curved-tooth planetary gear, represents the rotation angle of the coordinate where the curved-tooth planetary gear is located, represents the rotation angle of the coordinate where the ring gear is located, is the base circle radius of the ring gear, is the axis circle radius of the needle bearing of the ring gear.

6. The rotary joint actuator according to claim 5, characterized in that, The number of teeth of the ring gear is , and the number N of the curved-surface tooth planet gears can be determined by whether the formula is an integer. The transmission ratio of the planetary gear set is ; And / or, the tooth surfaces and the tooth surface formation functions of the sun gear, the surface tooth planetary gear, and the tooth ring include straight lines, oblique lines, arcs, parabolas, or spline curves; and / or, .

7. The rotary joint actuator according to claim 6, wherein: The curved surface gear planetary gears are divided into two layers, and each layer is evenly distributed with three curved surface gear planetary gears; , wherein the axis of the relative position curved surface gear planetary gear is set at a phase offset of 180° around the revolution center of the curved surface gear planetary gear; Or, the curved-tooth planetary gears are divided into two layers, and each layer is evenly distributed with 3 curved-tooth planetary gears, that is , and the curved-tooth planetary gears in the relative positions are coaxially connected and staggered in phase on the coaxial line; Or, the tooth ring is arranged in two layers and is respectively meshed with the two layers of surface tooth planetary gears through tooth ring needle bearings, and the number of tooth ring needle bearings is the number of teeth of the corresponding tooth ring.

8. A design method for a rotary joint actuator, characterized in that: It is realized by using a rotary joint actuator according to any one of claims 1-7.

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