Articulated actuator and its two-stage planetary reduction transmission

Abstract

The utility model discloses a two -stage planetary reduction drive mechanism, including one -stage planetary drive mechanism and two -stage planetary drive mechanism, one -stage planetary drive mechanism includes one -stage sun wheel and one -stage gear, and is equipped with a plurality of one -stage planetary gear and one -stage planet carrier for installing one -stage planetary gear between one -stage sun wheel and one -stage gear, and one -stage planetary gear is engaged with one -stage sun wheel and one -stage gear respectively, two -stage planetary drive mechanism includes two -stage sun wheel and two -stage gear, and is equipped with a plurality of two -stage planetary gear and two -stage planet carrier for installing two -stage planetary gear between two -stage sun wheel and two -stage gear, and two -stage planetary gear is engaged with two -stage sun wheel and two -stage gear respectively, still including the fixed sleeve of the sleeve setting in one -stage gear and two -stage gear outside, and one -stage gear and two -stage gear synchronous rotation cooperation between fixed sleeve, and one -stage sun wheel and two -stage sun wheel can rotate around its axis, and one -stage planet carrier is connected with two -stage sun wheel transmission. The utility model discloses a joint actuator.

Description

Technical Field

[0001] This utility model belongs to the field of robot technology, specifically a joint actuator and its two-stage planetary reduction transmission mechanism. Background Technology

[0002] As the core power component of a robot system, the joint actuator plays a crucial role in converting electrical energy into mechanical motion. Its performance directly affects the robot's motion accuracy, load capacity, response speed, and overall reliability. Technically, a typical joint actuator usually consists of modules such as a drive motor, reduction gear, sensor system, and control unit. These components are precisely integrated to achieve functions such as torque amplification, motion conversion, and closed-loop control. With the continuous expansion of robot applications, from industrial manufacturing to medical services, from space exploration to home services, the performance requirements for joint actuators are becoming increasingly diversified and stringent.

[0003] Mechanically reduced-speed articulated actuators have long dominated the field of industrial robots. Their core technology utilizes gear meshing to reduce the motor's output speed and amplify its torque. These actuators typically employ a three-stage architecture: the high-speed stage provides the initial power to the servo motor; the intermediate stage uses a precision reducer to achieve speed and torque variation; and the output stage integrates position / torque sensors to form a closed-loop control. Based on the type of reduction mechanism, mainstream solutions can be divided into three main categories: harmonic reducers, planetary reducers, and RV reducers, each with distinct performance characteristics and applicable scenarios. Among them, planetary reducers employ a multi-stage parallel gear splitting structure, offering advantages in high rigidity and high load capacity, and are commonly found in heavy-duty industrial robots. However, achieving a large transmission ratio with existing planetary reducers leads to an increase in radial dimensions, limiting their application in space-constrained environments. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a joint actuator and its two-stage planetary reduction transmission mechanism, which can not only meet the requirements of a large transmission ratio, but also reduce the radial dimension.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] This utility model first proposes a two-stage planetary reduction transmission mechanism, including a first-stage planetary transmission mechanism and a second-stage planetary transmission mechanism;

[0007] The primary planetary transmission mechanism includes a primary sun gear and a primary ring gear, with a plurality of primary planet gears and a primary planet carrier for mounting the primary planet gears provided between the primary sun gear and the primary ring gear; the primary planet gears mesh with the primary sun gear and the primary ring gear respectively;

[0008] The secondary planetary transmission mechanism includes a secondary sun gear and a secondary ring gear, with a plurality of secondary planet gears and a secondary planet carrier for mounting the secondary planet gears provided between the secondary sun gear and the secondary ring gear; the secondary planet gears mesh with the secondary sun gear and the secondary ring gear respectively;

[0009] It also includes a fixed sleeve fitted around the first-stage gear ring and the second-stage gear ring, the fixed sleeve being fixedly installed, and the first-stage gear ring and the second-stage gear ring rotating synchronously with the fixed sleeve; the first-stage sun gear and the second-stage sun gear can both rotate around their axes, and the first-stage planetary carrier and the second-stage sun gear are connected by a transmission.

[0010] Furthermore, the fixing sleeve is provided with an internal spline, and the primary gear ring and the secondary gear ring are respectively provided with external splines, and the primary gear ring and the secondary gear ring are respectively spline-fitted with the fixing sleeve.

[0011] Furthermore, a spacer sleeve is provided between the primary gear ring and the secondary gear ring, and the spacer sleeve is used to adjust the distance between the primary gear ring and the secondary gear ring.

[0012] Furthermore, the primary planetary carrier is disposed between the primary planetary gears and the secondary planetary gears, and the primary planetary carrier rotates synchronously with the secondary sun gear.

[0013] Furthermore, the axis of rotation of the first-stage planetary carrier and the second-stage sun gear are integrated.

[0014] This utility model also proposes a joint actuator, including a housing, a motor assembly inside the housing, the motor assembly including a stator and a rotor sleeved outside the stator, the stator having a central through hole, and a two-stage planetary reduction transmission mechanism as described above installed in the central through hole; a fixed sleeve sleeved inside the central through hole and fixedly connected to the housing, the first-stage sun gear being drivenly connected to the rotor, and an output flange being provided on the second-stage planetary carrier.

[0015] Furthermore, the housing includes a shell and an end cap mounted on the shell.

[0016] Furthermore, a connecting disc is connected to the rotor, and the connecting disc is located between the housing and the stator; the center of the connecting disc is provided with an axially extending connecting portion, and a connecting through hole is provided in the connecting portion, and the shaft of the first-stage sun gear is installed in the connecting through hole.

[0017] Furthermore, the housing is provided with a clearance hole to accommodate the connecting part, and the inner diameter of the fixing sleeve is larger than the outer diameter of the connecting part; deep groove ball bearings are respectively provided between the connecting part and the housing and the fixing sleeve.

[0018] Furthermore, the fixing sleeve is fixedly connected to the end cover, and a crossed roller bearing is provided between the fixing sleeve and the end cover and the secondary planetary carrier. A bushing is fitted on the secondary planetary carrier between the inner ring of the crossed roller bearing and the secondary gear ring. The bushing is used to position the primary gear ring and the secondary gear ring in the axial direction.

[0019] The beneficial effects of this utility model are as follows:

[0020] This utility model discloses a joint actuator by setting up a primary planetary transmission mechanism and a secondary planetary transmission mechanism. The rotor is connected to the primary sun gear, and the primary planetary carrier is connected to the secondary sun gear. An output flange is provided on the secondary planetary carrier. Thus, primary reduction is achieved by the primary planetary gears meshing with the primary ring gear and the primary sun gear, and secondary reduction is achieved by the secondary planetary gears meshing with the secondary ring gear and the secondary sun gear. The total reduction ratio of the two-stage planetary reduction transmission mechanism is the product of the transmission ratios of the primary and secondary planetary transmission mechanisms. This means that a larger transmission ratio can be achieved through two-stage reduction, and the transmission ratios of the primary and secondary planetary transmission mechanisms can be reduced respectively, thereby reducing the radius of the two-stage planetary reduction transmission mechanism. The axial length of the joint actuator can be reduced by setting a fixed sleeve and fitting the primary and secondary gear rings inside the fixed sleeve, allowing them to rotate synchronously with the fixed sleeve. Simultaneously, the fixed sleeve is fixedly installed in the central through hole of the stator. Furthermore, by separating the primary and secondary gear rings, the transmission ratios of the primary and secondary planetary transmission mechanisms can be flexibly adjusted. This not only meets the requirement for a larger transmission ratio but also allows for flexible adjustment of the load capacity of the primary and secondary planetary transmission mechanisms to meet load requirements. In summary, the joint actuator of this invention not only achieves the requirement for a larger transmission ratio but also reduces the radial dimension without increasing the axial dimension. Attached Figure Description

[0021] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the following drawings are provided for illustration:

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the joint actuator of this utility model;

[0023] Figure 2 for Figure 1 Left-axis projection;

[0024] Figure 3 for Figure 1 The right axonometric projection.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10-Housing; 101-Protrusion; 102-Connecting hole; 11-End cover; 12-Stator; 13-Rotor; 14-Fixing sleeve; 15-First-stage sun gear; 16-First-stage gear ring; 17-First-stage planetary gear; 18-First-stage planetary carrier; 19-Second-stage sun gear; 20-Second-stage gear ring; 21-Second-stage planetary gear; 22-Second-stage planetary carrier; 23-Output flange; 24-Connecting disc; 241-Connecting part; 242-Connecting through hole; 25-Magnetic ball; 26-Deep groove ball bearing; 27-Deep groove ball bearing; 28-Crossed roller bearing; 29-Spacer sleeve; 30-Shaft sleeve; 31-Circuit board. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0028] like Figure 1 As shown, the joint actuator of this embodiment includes a housing, within which a motor assembly is housed. In this embodiment, the housing includes a shell 10 and an end cap 11 mounted on the shell, with the end cap 11 and the shell 10 fixedly connected. The motor assembly includes a stator 12 and a rotor 13 sleeved outside the stator 12. The stator has a central through hole, within which a two-stage planetary reduction gear is installed.

[0029] In this embodiment, the two-stage planetary reduction gear mechanism includes a primary planetary transmission mechanism, a secondary planetary transmission mechanism, and a fixed sleeve 14. Specifically, the primary planetary transmission mechanism includes a primary sun gear 15 and a primary ring gear 16. A plurality of primary planetary gears 17 and a primary planet carrier 18 for mounting the primary planetary gears 17 are provided between the primary sun gear 15 and the primary ring gear 16. The primary planetary gears 17 mesh with the primary sun gear 15 and the primary ring gear 16 respectively. The secondary planetary transmission mechanism includes a secondary sun gear 19 and a secondary ring gear 20. A plurality of secondary planetary gears 21 and a secondary planet carrier 22 for mounting the secondary planetary gears 21 are provided between the secondary sun gear 19 and the secondary ring gear 20. The secondary planetary gears 21 mesh with the secondary sun gear 19 and the secondary ring gear 20 respectively.

[0030] In this embodiment, the fixing sleeve 14 is sleeved around the primary gear ring 16 and the secondary gear ring 20, and the fixing sleeve 14 is fixedly installed. The primary gear ring 16 and the secondary gear ring 20 are synchronously rotated with the fixing sleeve 14. That is, in this embodiment, the primary gear ring 16 and the secondary gear ring 20 are fixed and do not rotate. Specifically, in this embodiment, the fixing sleeve 14 is provided with an internal spline, and the primary gear ring 16 and the secondary gear ring 20 are respectively provided with external splines. The primary gear ring 16 and the secondary gear ring 20 are splinedly engaged with the fixing sleeve 14. In this way, the axial position of the primary gear ring 16 and the secondary gear ring 20 within the fixing sleeve 14 can be adjusted through the spline engagement, and the rotation of the primary gear ring 16 and the secondary gear ring 20 relative to the fixing sleeve 14 can be prevented.

[0031] In this embodiment, both the primary sun gear 15 and the secondary sun gear 19 can rotate around their axes, and the primary planetary carrier 18 and the secondary sun gear 19 are connected by a transmission. Specifically, the primary planetary carrier 18 is disposed between the primary planetary gear 17 and the secondary planetary gear 21, and the primary planetary carrier 18 and the secondary sun gear 19 rotate synchronously. In a preferred embodiment, the shafts of the primary planetary carrier 18 and the secondary sun gear 19 are integrated, which simplifies the structure.

[0032] In this embodiment, the fixing sleeve 14 is fitted inside the central through hole and fixedly connected to the outer shell. The first-stage sun gear 15 is driven by the rotor 13, and the second-stage planetary carrier 22 is provided with an output flange 23. Specifically, a connecting disc 24 is connected to the rotor 13, and the connecting disc 24 is located between the housing 10 and the stator 12. The center of the connecting disc 24 is provided with an axially extending connecting portion 241, and a connecting through hole 242 is provided inside the connecting portion 241. The shaft of the first-stage sun gear 15 is installed in the connecting through hole 242. In this embodiment, the first-stage sun gear 15 rotates synchronously with the rotor 13 through the connecting disc 24. In this embodiment, a magnetic bead 25 is provided at the end of the connecting through hole 242 facing away from the first-stage sun gear 15.

[0033] In this embodiment, the housing 10 is provided with a clearance hole for the clearance connecting part 241, and the inner diameter of the fixing sleeve 14 is larger than the outer diameter of the connecting part 241. A deep groove ball bearing 26 and a deep groove ball bearing 27 are respectively provided between the connecting part 241 and the housing 10 and the fixing sleeve 14.

[0034] In this embodiment, the fixing sleeve 14 is fixedly connected to the end cover 11, and a crossed roller bearing 28 is provided between the fixing sleeve 14, the end cover 11, and the secondary planetary carrier 22. In this embodiment, a spacer sleeve 29 is provided between the primary gear ring 16 and the secondary gear ring 20. The spacer sleeve 29 is used to adjust the distance between the primary gear ring 16 and the secondary gear ring 20. The end of the primary gear ring 16 facing away from the secondary gear ring 20 is matched with the outer ring of the deep groove ball bearing 27. In this embodiment, a bushing 30 is fitted on the secondary planetary carrier 22 between the inner ring of the crossed roller bearing 28 and the secondary gear ring 20. Under the axial positioning action of the spacer sleeve 29 and the bushing 30, the positions of the primary gear ring 16 and the secondary gear ring 20 in the axial direction can be positioned.

[0035] Specifically, in this embodiment, the number of teeth on the first-stage planetary gear 17 and the second-stage planetary gear 21 are equal, the number of teeth on the first-stage sun gear 15 and the second-stage sun gear 19 are equal, and the number of teeth on the first-stage ring gear 16 and the second-stage ring gear 20 are equal. That is, in this embodiment, the transmission ratios of the first-stage planetary transmission mechanism and the second-stage planetary transmission mechanism are the same. Of course, in some other embodiments, the transmission ratios of the first-stage planetary transmission mechanism and the second-stage planetary transmission mechanism may not be the same. For example, the number of teeth on the first-stage planetary gear 17 and the second-stage planetary gear 21 may be unequal, the number of teeth on the first-stage sun gear 15 and the second-stage sun gear 19 may be unequal, and the number of teeth on the first-stage ring gear 16 and the second-stage ring gear 20 may be unequal, which will not be elaborated further. Specifically, the transmission ratio of the first-stage planetary transmission mechanism can be flexibly adjusted by adjusting the number of teeth on the first-stage ring gear 16, the first-stage planetary gear 17, and the first-stage sun gear 15; similarly, the transmission ratio of the second-stage planetary transmission mechanism can be flexibly adjusted by adjusting the number of teeth on the second-stage ring gear 20, the second-stage planetary gear 21, and the second-stage sun gear 19; by adjusting the transmission ratios of the first-stage and second-stage planetary transmission mechanisms, the load capacity of the first-stage and second-stage planetary transmission mechanisms can also be flexibly adjusted to meet load requirements.

[0036] In this embodiment, the end face of the housing 10 is provided with a protrusion 101, and the protrusion 101 is provided with connecting holes 102 at intervals. The protrusion 101 and the connecting holes 102 are used to mount circuit boards 31, etc., and will not be described in detail.

[0037] The joint actuator in this embodiment uses a primary planetary transmission mechanism and a secondary planetary transmission mechanism to connect the rotor to the primary sun gear and the primary planetary carrier to the secondary sun gear. An output flange is provided on the secondary planetary carrier. Thus, primary reduction is achieved by the primary planetary gears meshing with the primary ring gear and the primary sun gear, and secondary reduction is achieved by the secondary planetary gears meshing with the secondary ring gear and the secondary sun gear. The total reduction ratio of the two-stage planetary reduction transmission mechanism is the product of the transmission ratios of the primary and secondary planetary transmission mechanisms. This means that a larger transmission ratio can be achieved through two-stage reduction, and the transmission ratios of the primary and secondary planetary transmission mechanisms can be reduced respectively, thereby reducing the radius of the two-stage planetary reduction transmission mechanism. Regarding the axial dimensions, by setting a fixed sleeve and fitting the primary and secondary gear rings inside the fixed sleeve and rotating synchronously with it, while fixing the fixed sleeve in the central through hole of the stator, the axial length of the joint actuator can be reduced. Furthermore, by separating the primary and secondary gear rings, the transmission ratios of the primary and secondary planetary transmission mechanisms can be flexibly adjusted. This not only meets the requirement for a larger transmission ratio but also allows for flexible adjustment of the load capacity of the primary and secondary planetary transmission mechanisms to meet load requirements. In summary, the joint actuator of this embodiment not only achieves the requirement for a larger transmission ratio but also reduces the radial dimension without increasing the axial dimension.

[0038] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A two-stage planetary reduction gear mechanism, characterized in that: Includes a primary planetary transmission mechanism and a secondary planetary transmission mechanism; The primary planetary transmission mechanism includes a primary sun gear and a primary ring gear, with a plurality of primary planet gears and a primary planet carrier for mounting the primary planet gears provided between the primary sun gear and the primary ring gear; the primary planet gears mesh with the primary sun gear and the primary ring gear respectively; The secondary planetary transmission mechanism includes a secondary sun gear and a secondary ring gear, with a plurality of secondary planet gears and a secondary planet carrier for mounting the secondary planet gears provided between the secondary sun gear and the secondary ring gear; the secondary planet gears mesh with the secondary sun gear and the secondary ring gear respectively; It also includes a fixed sleeve fitted around the first-stage gear ring and the second-stage gear ring, the fixed sleeve being fixedly installed, and the first-stage gear ring and the second-stage gear ring rotating synchronously with the fixed sleeve; the first-stage sun gear and the second-stage sun gear can both rotate around their axes, and the first-stage planetary carrier and the second-stage sun gear are connected by a transmission.

2. The two-stage planetary reduction gear mechanism according to claim 1, characterized in that: The fixed sleeve is provided with an internal spline, and the primary gear ring and the secondary gear ring are respectively provided with external splines, and the primary gear ring and the secondary gear ring are respectively spline-fitted with the fixed sleeve.

3. The two-stage planetary reduction gear mechanism according to claim 2, characterized in that: A spacer sleeve is provided between the primary gear ring and the secondary gear ring, and the spacer sleeve is used to adjust the distance between the primary gear ring and the secondary gear ring.

4. The two-stage planetary reduction gear mechanism according to claim 1, characterized in that: The primary planetary carrier is positioned between the primary planetary gears and the secondary planetary gears, and the primary planetary carrier rotates synchronously with the secondary sun gear.

5. The two-stage planetary reduction gear mechanism according to claim 4, characterized in that: The primary planetary carrier and the secondary sun gear are integrated into one unit.

6. A joint actuator, characterized in that: The device includes a housing, within which a motor assembly is provided. The motor assembly includes a stator and a rotor sleeved outside the stator. The stator has a central through hole, and a two-stage planetary reduction gear as described in any one of claims 1-5 is installed in the central through hole. A fixed sleeve is sleeved in the central through hole and fixedly connected to the housing. The first-stage sun gear is driven by the rotor. An output flange is provided on the second-stage planetary carrier.

7. The joint actuator according to claim 6, characterized in that: The outer casing includes a housing and end caps mounted on the housing.

8. The joint actuator according to claim 7, characterized in that: The rotor is connected to a connecting disc, which is located between the housing and the stator; the center of the connecting disc is provided with an axially extending connecting portion, and the connecting portion is provided with a connecting through hole, and the shaft of the first-stage sun gear is installed in the connecting through hole.

9. The joint actuator according to claim 8, characterized in that: The housing is provided with a clearance hole to accommodate the connecting part, and the inner diameter of the fixing sleeve is larger than the outer diameter of the connecting part; deep groove ball bearings are respectively provided between the connecting part and the housing and the fixing sleeve.

10. The joint actuator according to claim 7, characterized in that: The fixed sleeve is fixedly connected to the end cover. A crossed roller bearing is provided between the fixed sleeve and the end cover and the secondary planetary carrier. A bushing is sleeved on the secondary planetary carrier between the inner ring of the crossed roller bearing and the secondary gear ring. The bushing is used to position the primary gear ring and the secondary gear ring in the axial direction.

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