Rotary joint actuator and design method thereof

Abstract

The invention discloses a rotary joint actuator and a design method thereof.The rotary joint actuator comprises a fixed shell, the fixed shell comprises a front cover and a rear cover, and a frameless motor and a cam curved surface tooth planetary reducer are both arranged in a mounting cavity reserved between the front cover and the rear cover; the driving device is connected with the frameless motor; the driving device comprises a driving plate, the 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 curved surface tooth planetary reducer comprises an input bearing, a planetary needle bearing, a planetary carrier set and a planetary gear set. The planetary gear set comprises a sun gear, a curved surface tooth planet gear and a gear ring which is in conjugate engagement with the curved surface tooth planet gear. The invention discloses a rotary joint actuator and a design method thereof, and the rotary joint actuator is compact in structure and has the characteristics of large transmission ratio, high transmission precision and good stability under the condition of size control.

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 limited 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 as follows: 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 is meshed with the cam - surface - tooth planetary gear and fixedly connected to the flange, 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. 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 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. And / or, the sun gear and the surface tooth planetary gear form an external meshing spur gear drive. And / or, the surface tooth planetary gear and the ring gear form an internal meshing spur gear drive.

[0009] 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. The tooth surface of the 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 surface tooth planetary gear to obtain the tooth surface equation of the surface tooth planetary gear. The tooth surface of the ring gear is composed of a conjugate curve formed by the spline curve of the 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. The tooth profiles of the ring gear, 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 ring gear, the surface tooth planetary gear, and the sun gear.

[0010] In a preferred embodiment of the present invention, the tooth surface equation of the sun gear is: ; 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 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.

[0011] In a preferred embodiment of the present invention, the tooth surface equation of the surface tooth planetary gear is: ; Wherein, is the center distance between the sun gear and the surface 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 surface 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, and the transmission ratio between the curved-tooth planetary gear and the sun gear, is the base circle radius of the curved-tooth planetary gear.

[0012] In a preferred embodiment of the present invention, the tooth surface equation of the ring gear is: ; wherein, 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.

[0013] 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 meshes only with one side tooth surface of the curved-tooth planetary 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 surface tooth planetary gear; wherein, 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 form change parameter function , wherein represents the inclination angle of the conical tooth surface; in the tooth thickness direction of the conical tooth surface gear, the tooth surface form change parameter function ; the tooth surface form change parameter of the conical tooth surface gear ; 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 only with 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 meshes only with the other side tooth surface of the curved-tooth planetary 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 form change parameter function ; in the tooth thickness direction of the arc tooth surface gear, the tooth surface form change parameter function ; the tooth surface form change parameter of the arc tooth surface gear ; 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 change parameter of the straight tooth surface gear , 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 variation parameters of spur gears ; and the sun gear and the curved-tooth planetary gear form an external meshing spur gear transmission, and the curved-tooth planetary gear and the ring gear form an internal meshing spur gear transmission.

[0014] In a preferred embodiment of the present invention, the number of teeth of the gear ring is , and the number of curved planetary gears N can be obtained by Whether the formula is an integer or not, 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, .

[0015] In a preferred embodiment of the present invention, the curved surface gear planetary gear is divided into two layers, and three curved surface gear planetary gears are evenly distributed in each layer; , wherein the axis of the relative position curved surface gear planetary gear is arranged at a phase difference of 180° around the revolution center of the curved surface gear planetary gear; Or, the curved surface gear planetary gear is divided into two layers, and each layer is evenly distributed with 3 curved surface gear 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; Alternatively, the gear ring is provided with two layers, and is meshed with the two layers of curved surface gear planetary gears through gear ring needle roller bearings respectively, and the number of gear ring needle roller bearings is the number of teeth of the corresponding gear ring.

[0016] In a preferred embodiment of the present invention, a design method of a rotary joint actuator is implemented using a rotary joint actuator.

[0017] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are: The present invention discloses a rotary joint actuator and a design method thereof. The present invention discloses a cam curve planetary rotary joint actuator for a humanoid robot. The actuator has a compact structure and can have a large transmission ratio, high transmission accuracy, good stability, etc. under the condition of controlling the size. The transmission ratio is increased on the basis of high torque, high rigidity, and impact resistance.

[0018] The 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. The cam surface tooth planetary reducer is a cam surface tooth planetary reducer with a compact structure. Under the condition of controlling the size, it can obtain a large transmission ratio and high transmission precision. Moreover, the number of teeth of the sun gear is only [specific number], which can avoid the root cutting phenomenon 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

[0019] The present invention will be further described below in conjunction with the drawings and embodiments.

[0020] Figure 1 is a three-dimensional structure schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention; Figure 2 is a three-dimensional sectional view of a rotary joint actuator according to a preferred embodiment of the present invention; Figure 3 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ; Figure 4 is an embodiment schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ; Figure 5 is a gear tooth surface schematic diagram of a preferred embodiment of the present invention Figure 1 ; Figure 6 is a gear tooth surface schematic diagram of a preferred embodiment of the present invention Figure 2 ; Figure 7 is a gear tooth surface schematic diagram of a preferred embodiment of the present invention Figure 3 ; Figure 8 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 2 ; Figure 9 is an embodiment schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 2 ; Figure 10 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 3 ; Figure 11 is an embodiment schematic diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 3 ; Figure 12 is the assembly of a rotary joint actuator according to a preferred embodiment of the present invention Figure 4 ; Figure 13Schematic diagram of an embodiment of a rotary joint actuator according to a preferred embodiment of the present invention Figure 4 ; Figure 14 Explosion diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 1 ; Figure 15 Explosion diagram of a rotary joint actuator according to a preferred embodiment of the present invention Figure 2 ; 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, stop collar; 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

[0021] Now, the present invention will be further described in detail with reference to the accompanying 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.

[0022] 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 understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Unless otherwise clearly defined and limited, the terms "set", "connected", and "connected to" 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 internal communication of 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 situations. Embodiment 1

[0023] 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 tooth 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 tooth 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 arranged on the driving plate 3; the frameless motor 200 is connected to the cam surface tooth 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 tooth 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 tooth planetary reducer 300 can have a high reduction ratio under the condition of a fixed size and is fixed inside the fixed housing 100.

[0024] 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 a first planetary carrier 5 and the rear cover 2 through the input bearing 10 and a 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 conjugated and 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, and the tooth ring 19 is coaxially disposed in a spigot bracket 11 through a first output bearing 15 and a 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.

[0025] Further, the planet carrier group includes a first planet carrier 5 and a second planet carrier 12. The planetary needle roller bearings 14 are respectively connected to the first planet carrier 5 and the second planet carrier 12. The curved-tooth planet gears 20 are respectively connected to the first planet carrier 5 and the second planet carrier 12 through the planetary needle roller bearings 14. The sun gear 22 and the curved-tooth planet gears 20 form an external meshing spur gear drive; the curved-tooth planet gears 20 and the ring gear 19 form an internal meshing spur gear drive. That is, the planetary gear set 13 includes the sun gear 22, a plurality of curved-tooth planet gears 20, and the ring gear 19; the plurality of curved-tooth planet gears 20 are arranged around the sun gear 22, and the periphery of the sun gear 22 meshes with the curved-tooth planet gears 20; the curved-tooth planet gears 20 are located inside the ring gear 19, and the ring gear 19 is in conjugate meshing with the curved-tooth planet gears 20.

[0026] Further, the tooth profile of the sun gear 22 is a cam curve, the tooth profile of the curved-tooth planet gear 20 is a spline curve conjugate to the cam curve formed according to the relative motion relationship, and the tooth profile of the ring gear 19 is a conjugate curve formed according to the relative motion relationship of a cam curve; the tooth profiles of the ring gear 19, the curved-tooth planet 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 ring gear 19, the curved-tooth planet gear 20, and the sun gear 22. Embodiment 2

[0027] 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 curved-tooth planetary reducer 300. Specifically, the driving device 400 is responsible for providing motor control for the rotary joint actuator; the frameless motor 200 provides driving force for the rotary joint actuator; the cam curved-tooth planetary reducer 300 is a cam curved-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.

[0028] As Figure 1 、 Figure 2As shown, 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, and the driving cover plate 1 is fixed outside 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 to the flange 8 coaxially. The stator 16 is connected to the cam surface tooth planetary reducer 300 through a spigot support 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 to the flange 8 coaxially through the input bearing 10; the first planet carrier 5 is connected to the spigot support 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.

[0029] As Figure 2 , Figure 3 shown, in the cam surface tooth planetary reducer 300, the planetary gear set 13 includes a ring gear 19, a surface tooth planetary gear 20 and a sun gear 22 with conjugate meshing tooth profiles; 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, and the tooth profile of the ring gear 19 is a conjugate curve formed according to the relative motion relationship of the section of curve. The tooth profiles of the three gears perform meshing motion according to the quantitative relationship, forming the conjugate meshing tooth profiles of the three gears.

[0030] Specifically, the tooth profile equation of the sun gear 22 is: ; 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.

[0031] Specifically, the tooth surface equation of the surface tooth planetary gear 20 is: ; Wherein, is the center distance between the sun gear 22 and the curved-tooth planetary 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 planetary gear 20 is located, is the number of teeth of the sun gear 22, is the number of teeth of the curved-tooth planetary gear 20, is the tooth number ratio of the curved-tooth planetary gear 20 to the sun gear 22, and the transmission ratio of the curved-tooth planetary gear 20 to the sun gear 22, is the base circle radius of the curved-tooth planetary gear 20.

[0032] Specifically, the tooth surface equation of the ring gear 19 is: ; 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 planetary gear 20, represents the rotation angle of the coordinate where the curved-tooth planetary 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.

[0033] In some 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 planetary 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 planetary gear 20 form an external meshing spur gear transmission. The curved-tooth planetary gear 20 and the ring gear 19 form an internal meshing spur gear transmission. And the tooth surfaces and tooth surface formation functions of the sun gear 22, the curved-tooth planetary gear 20, and the ring gear 19 are not limited to straight lines, oblique lines, arcs, parabolas, or other spline curves. Embodiment Three

[0034] On the basis of Embodiment Two, as Figure 5 shown, the tooth surfaces of the sun gear 22, the curved-tooth planetary gear 20, and the ring gear 19 are conical tooth surfaces; the conical tooth surface curved-tooth planetary gear 20a, the conical tooth surface sun gear 22a, and the conical tooth surface ring gear 19a shown in Figure 5 are respectively adopted.

[0035] Specifically, the curved-tooth planetary gear 20 adopts the one as shown in Figure 5The conical tooth surface curved tooth planet gear 20a shown has a tooth surface of a double conical tooth surface that is symmetric about the left and right; the sun gear 22 is a 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 it meshes only with one side tooth surface of the conical tooth surface curved tooth planet gear 20a; the ring gear 19 is a 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 it meshes only with the other side tooth surface of the conical tooth surface curved tooth planet gear 20a.

[0036] 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 4

[0037] On the basis of Example 2, as shown in Figure 6 , the tooth surfaces of the sun gear 22, the curved tooth planet gear 20, and the ring gear 19 are arc tooth surfaces; respectively, an arc tooth surface curved tooth planet gear 20b, an arc tooth surface sun gear 22b, and an arc tooth surface ring gear 19b as shown in Figure 6 are used.

[0038] Specifically, the curved tooth planet gear 20 uses an 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 an arc tooth surface that is symmetric about the left and right; the sun gear 22 uses an 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 it meshes only with one side tooth surface of the arc tooth surface curved tooth planet gear 20b; the ring gear 19 uses an 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 it meshes only with the other side tooth surface of the arc tooth surface curved tooth planet gear 20b.

[0039] Among them, the tooth surface tooth thickness change parameter of the arc tooth surface gear , 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 parameter of the arc tooth surface gear . Embodiment 5

[0040] Based on the second embodiment, Figure 7 As shown, the tooth surfaces of the sun gear 22, the curved-tooth planetary gear 20 and the ring gear 19 are straight tooth surfaces; Figure 7 The spur-tooth curved-surface planetary gears 20c, the spur-tooth sun gear 22c, and the spur-tooth ring gear 19c are shown.

[0041] The tooth surfaces of the spur-tooth sun gear 22c, the spur-tooth curved-tooth planetary gear 20c and the spur-tooth ring gear 19c are all spur-tooth surfaces. The tooth thickness variation parameter of the spur-tooth gear is , B is the tooth surface thickness of the spur gear sun gear 22c; 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 variation parameters of spur gears The spur gear sun gear 22c and the spur gear curved surface gear planetary gear 20c form an external meshing spur gear transmission, and the spur gear curved surface gear planetary gear 20c and the spur gear ring gear 19c form an internal meshing spur gear transmission. Embodiment 6

[0042] Based on any one of the embodiments from Embodiment 2 to Embodiment 5, Figure 3 , Figure 4 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, that is, , wherein the axis of the curved-tooth planetary gear 20 is arranged at a relative position with a phase difference of 180° around the revolution center of the curved-tooth planetary gear 20 .

[0043] Specifically, the arrangement of the planetary gear set 13 is as follows: Figure 3 As shown. The planetary needle bearing 14 is 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 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 respectively evenly distributed with three curved surface gear planetary gears, wherein the axes of the curved surface gear planetary gears are arranged at a phase staggered by 180° around the revolution center of the curved surface gear planetary gears, and are connected to the planetary needle bearing 14; the ring gear 19 is provided with two layers of internal gears meshing with the curved surface gear planetary gear 20 and the second layer of curved surface gear 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 meshing with the curved surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21 respectively. Embodiment 7

[0044] Based on any one of Embodiments 2 to 5, as Figure 8 , Figure 9 shown, the curved-tooth planetary gear 20 is divided into two layers, and each layer is evenly distributed with 3 curved-tooth planetary gears 20, that is , among which the curved-tooth planetary gears 20 in relative positions are coaxially connected and are offset by phases on the coaxial line.

[0045] Specifically, the arrangement of the planetary gear set 13 is as Figure 8 shown. The planetary needle roller bearing 14 is connected to the second planet carrier 12; the planetary gear set 13 is provided with two layers, including a ring gear 19, a curved-tooth planetary gear 20, a second-layer curved-tooth planetary gear 21, and a sun gear 22; the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21 are each evenly distributed with 3 curved-tooth planetary gears, among which the curved-tooth planetary gears 20 in relative positions are coaxially connected and are offset by phases ( is the number of teeth of the curved-tooth planetary gear) and are 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 spigot support 11; the sun gear 22 is coaxially connected to the flange 8, and its gear part is two cam curve gears offset by 180°, and respectively meshes with the curved-tooth planetary gear 20 and the second-layer curved-tooth planetary gear 21. Embodiment 8

[0046] Based on any one of Embodiments 2 to 5, as Figure 10 , Figure 11 shown, the ring gear 19 is provided with two layers of ring gear needle roller bearings 23 respectively meshing with the two layers of curved-tooth planetary gears 20, and the number of ring gear needle roller bearings 23 is the number of teeth of the corresponding ring gear.

[0047] Specifically, the arrangement of the planetary gear set 13 is as Figure 10As shown. The planetary needle roller bearing 14 is 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 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 respectively evenly distributed with three curved surface gear planetary gears, wherein the axes of the curved surface gear planetary gears in relative positions are arranged at a phase offset of 180° around the revolution center of the curved surface gear planetary gears, and are 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 surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21, and the number of the ring gear needle roller bearings 23 is 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 offset by 180°, and meshing with the first layer of curved surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21 respectively. Embodiment 9

[0048] Based on 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 configured as two layers of gear ring needle bearings 23 respectively meshing with two layers of curved surface gear planetary gears 20, and the number of gear ring needle bearings 23 is the same as the number of teeth of the corresponding gear ring.

[0049] Specifically, the arrangement of the planetary gear set 13 is as follows: Figure 12 The planetary needle bearing 14 is connected to the first planet carrier 5; the planetary gear set 13 is provided with two layers, including a gear ring 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 respectively evenly distributed with three curved surface gear planetary gears, wherein the curved surface gear planetary gears at relative positions are arranged in a coaxial connection and staggered on the coaxial line. Phase ( is the number of teeth of the curved surface gear 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 surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21, and the number of the ring gear needle roller bearings 23 is 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 are respectively meshed with the curved surface gear planetary gear 20 and the second layer of curved surface gear planetary gear 21. Embodiment 10

[0050] Based on the second embodiment, is the number of teeth of the sun gear 22, and . Embodiment 11

[0051] A design method of a rotary joint actuator is realized by using a rotary joint actuator in any one of Embodiment 1 to Embodiment 9.

[0052] Working principle: 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 undercut phenomenon 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.

[0053] The above specific implementation manners 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 this technical solution according to 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 comprises a fixed housing, and a frameless motor, a cam-curved-tooth planetary reducer, and a driving device arranged in the fixed housing; the frameless motor is connected to the driving device; the frameless motor is connected to the cam-curved-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-curved-tooth planetary reducer; The cam curved surface gear planetary reducer comprises an input bearing, a planetary needle roller bearing, a planetary carrier set, and a planetary gear set; the flange is connected to the planetary carrier set through the input bearing, and the planetary gear set is connected to the planetary gear set through the planetary needle roller bearing; The planetary gear set includes a sun gear, a curved-tooth planetary gear, and a ring gear that is conjugately meshed with the curved-tooth planetary gear; the sun gear is meshed with the curved-tooth planetary gear and is fixedly connected to a flange, the ring gear is coaxially arranged in a stop frame through a first output bearing and a second output bearing, and the curved-tooth planetary gear is connected to the planetary gear set through a planetary needle bearing.

2. A rotary joint actuator according to claim 1, characterized in that: The fixed housing comprises a front cover and a rear cover, an installation cavity is reserved between the front cover and the rear cover, and the frameless motor and the cam curved surface gear planetary reducer are both arranged in the installation cavity; the driving device comprises 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 to the inside of the driving cover plate, and the encoder is fixedly arranged on the driving plate; And / or, the sun gear and the curved-tooth planetary gears form an external meshing spur gear transmission; And / or, the curved-tooth planetary gear and the ring gear form an internally meshing spur gear transmission; And / or, the planet carrier set includes a first planet carrier and a second planet carrier, the planetary needle roller bearings are respectively connected to the first planet carrier and the second planet carrier, and the curved gear planetary gear is respectively connected to the first planet carrier and the second planet carrier through the planetary needle roller bearings.

3. A rotary joint actuator according to claim 1, characterized in that: The tooth surface of the sun gear is formed by a cam curve and a tooth surface forming function of the sun gear, and the tooth surface equation of the sun gear is obtained; The tooth surface of the curved surface gear planetary gear is composed of a spline curve conjugate with the cam curve formed according to the relative motion relationship of the cam curve and a tooth surface formation function of the curved surface gear planetary gear, and a tooth surface equation of the curved surface gear planetary gear is obtained; The tooth surface of the gear ring is composed of a conjugate curve formed by the spline curve of the curved surface gear planetary gear according to the relative motion relationship and a function formed by the tooth surface of the gear ring, so as to obtain the tooth surface equation of the gear ring; The tooth profiles of the ring gear, the curved surface gear planetary gear and the sun gear mesh according to the gear transmission ratio relationship, forming conjugate meshing tooth profiles of the ring gear, the curved surface gear planetary gear and the sun gear.

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

5. A rotary joint actuator as claimed in claim 4, characterized in that: The tooth surface equation of the curved tooth planetary gear is: ； in, is the center distance between the sun gear and the curved planet gear, Indicates the rotation angle of the coordinates of the sun gear, Indicates the rotation angle of the coordinates of the curved planetary gear. is the number of teeth of the sun gear, is the number of teeth of the curved planetary gear, is the gear ratio between the curved planetary gear and the sun gear, and the transmission ratio between the curved planetary gear and the sun gear, is the base circle radius of the curved tooth planetary gear.

6. A rotary joint actuator according to claim 5, characterized in that: The tooth surface equation of the gear ring is: ； in, is the number of teeth on the ring gear, is the gear ratio between the ring gear and the curved gear planetary gear, and the transmission ratio between the ring gear and the curved gear planetary gear, Indicates the rotation angle of the coordinates of the curved planetary gear. Indicates the rotation angle of the coordinates of the gear ring. is the base circle radius of the gear ring, is the axis center radius of the gear ring needle roller bearing.

7. A rotary joint actuator as claimed in claim 4, characterized in that: The tooth surfaces of the sun gear, curved-tooth planetary gear and ring gear are conical tooth surfaces; the tooth surface of the curved-tooth planetary gear is a bilaterally symmetrical double-conical tooth surface; the tooth surface of the sun gear is a single-conical tooth surface, and only meshes with the tooth surface of the curved-tooth planetary gear on one side; the tooth surface of the ring gear is a single-conical tooth surface, and only meshes with the tooth surface of the conical-curved-tooth planetary gear on the other side; Among them, the tooth thickness variation 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 morphology change parameter function ,in Indicates the inclination angle of the conical tooth surface; the parameter function of the tooth surface shape change in the tooth thickness direction of the conical tooth surface gear ; Tooth surface morphology change parameters of conical tooth surface gears ; And / or, the tooth surfaces of the sun gear, the curved-tooth planetary gear and the ring gear are circular arc tooth surfaces; the tooth surface of the curved-tooth planetary gear is a bilaterally symmetrical double circular arc tooth surface; the tooth surface of the sun gear is a single circular arc tooth surface that meshes only with the tooth surface on one side of the curved-tooth planetary gear; the tooth surface of the ring gear is a single circular arc tooth surface that meshes only with the tooth surface on the other side of the curved-tooth planetary gear; wherein the tooth thickness variation parameter of the circular arc tooth surface gear is , B is the tooth surface thickness of the sun gear; in the tooth profile direction of the circular 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 ; Parameters of tooth surface shape change of circular arc tooth surface gear ; And / or, the tooth surfaces of the sun gear, the curved-tooth planetary gear and the ring gear are spur tooth surfaces; wherein the tooth thickness variation parameter of the spur 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 variation parameters of spur gears ; and the sun gear and the curved-tooth planetary gear form an external meshing spur gear transmission, and the curved-tooth planetary gear and the ring gear form an internal meshing spur gear transmission.

8. A rotary joint actuator as claimed in claim 6, characterized in that: The number of teeth of the gear ring is , and the number of curved planetary gears N can be obtained by The transmission ratio of the planetary gear set is determined by whether the formula is an integer. ; And / or, the tooth surfaces of the sun gear, curved-tooth planetary gear, and ring gear and the tooth surface forming function include straight lines, oblique lines, circular arcs, parabolas, or spline curves; and / or, .

9. A rotary joint actuator according to claim 8, characterized in that: 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 arranged at a phase difference of 180° around the revolution center of the curved surface gear planetary gear; Or, the curved surface gear planetary gear is divided into two layers, and each layer is evenly distributed with three curved surface gear 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; Alternatively, the gear ring is provided with two layers, and is respectively meshed with the two layers of curved surface gear planetary gears through gear ring needle roller bearings, and the number of the gear ring needle roller bearings is the number of teeth of the corresponding gear ring.

10. A design method for a rotary joint actuator, characterized in that: The invention is implemented by using a rotary joint actuator as described in any one of claims 1 to 9.

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