Self-locking reduction drive device

Abstract

A self-locking deceleration drive device comprises a motor, a compound planetary gear set, and an output gear installed within a housing. The motor drives the output gear via the compound planetary gear set to output decelerated rotational power. The compound planetary gear set, by virtue of its configuration of at least two fixed internal gear rings pivotally connected to a movable internal gear ring, possesses the dual functions of self-locking and outputting decelerated rotational power. This facilitates its application to equipment such as unmanned vehicles, controlling the direction or angle of the equipment during travel or flight, and resisting reverse loads fed back from the equipment, thereby saving power consumption of the equipment.

Description

Self-locking reduction drive device Technical Field

[0001] This invention relates to a technology that can generate forward deceleration rotational power and also has reverse braking rotation, and particularly to a self-locking drive device that can be applied to unmanned vehicles. Prior Technology

[0002] Remote-controlled cars and remote-controlled aircraft can generally be referred to as unmanned vehicles. These unmanned vehicles usually require a deceleration drive device to control their driving or flight direction or angle, such as the left or right swaying direction or angle of the wheels of a remote-controlled car, or the up or down swinging direction or angle of the flaps of a remote-controlled aircraft.

[0003] The reduction drive typically consists of a motor driving a reducer to output a forward-decelerating rotational force to control the forward direction or angle of the unmanned vehicle. When the reduction drive moves the unmanned vehicle to a specific direction or angle, the force acting on the front wheel or the flap is transmitted to the motor in the reduction drive to maintain the unmanned vehicle's specific direction or angle. At this time, the motor must continuously receive a power supply (or other energy) to keep the unmanned vehicle in that specific direction or angle, which creates the problem of continuously consuming the unmanned vehicle's reserve power (or other energy).

[0004] The main reason for the above problems is that the existing motor reduction mechanism lacks ideal self-locking function; in other words, when the reduction mechanism connected to the motor transmission encounters the resistance of the force generated at the load end (i.e., reverse load), the reduction mechanism lacks ideal self-locking ability to maintain its predetermined rotation angle, which causes the motor to have to continuously receive electrical (or other energy) excitation in order to maintain (or lock) its predetermined rotation angle.

[0005] Chen Ru, in the existing patent TWI675973B, teaches the use of a locking unit that has the function of locking certain specific rotation angles. However, the structure has many and complex parts and cannot be locked at any angle position. In other words, the patented technology, as a linkage mechanism of the output shaft, can only be locked at three specific angle positions within one rotation, which is not suitable for use in the motor drive connection of unmanned vehicles that must arbitrarily control multiple specific forward directions or angles.

[0006] For example, the worm gear and worm reduction transmission configuration taught in patent TWI866269B claims to solve the problem of the difficulty in effectively reducing the size of motor reduction transmission mechanisms; however, to achieve a high reduction ratio, the structural volume of a typical worm gear and worm reduction transmission configuration is inevitably difficult to reduce effectively. Furthermore, while worm gears and worms are known to have a self-locking function, this is difficult to adopt when a high reduction ratio is required, thus increasing the size. Therefore, the worm gear and worm configuration technology disclosed in patent TWI866269B presents the challenge of simultaneously achieving both a high reduction ratio and self-locking.

[0007] Therefore, if the focus is on locking and controlling the direction or angle of travel or flight of unmanned vehicles, there is currently no suitable deceleration drive technology available for application, which may even lead to the consumption of the onboard power (or other energy) of the unmanned vehicles. Therefore, it is urgent to improve this technology. Summary of the Invention

[0008] Therefore, the inventors of this invention have focused on developing a self-locking reduction drive device suitable for installation and use on unmanned vehicles. This device includes a motor or a geared motor for driving a compound planetary gear set. When the motor or geared motor drives the compound planetary gear set to control the direction or angle of travel or flight of the unmanned vehicle, especially when encountering a reverse load, the self-locking function provided by the compound planetary gear set can directly resist the reverse load without consuming backup power (or other energy) to continuously excite the motor. This saves the power consumption of the unmanned vehicle and helps to increase the operating time of the unmanned vehicle.

[0009] The reverse load refers to the force generated by the load end. The self-locking means that the reduction drive device has the function of locking (or resisting) the reverse load and preventing the reverse load from being fed back to the motor.

[0010] In addition, the self-locking reduction drive device provided by this invention is also suitable for use in other equipment that require resisting the reverse load, besides unmanned vehicles. Moreover, the self-locking reduction drive device has a simple structure and a high reduction ratio transmission efficiency.

[0011] This invention will provide two embodiments to illustrate the structural details of the self-locking reduction drive device. Wherein:

[0012] In a first embodiment of the self-locking reduction drive device, a motor, a compound planetary gear set, and an output gear are installed within a housing. The motor comprises a stator fixed within the housing and a rotor pivotally mounted within the stator and rotating under electromagnetic induction. The compound planetary gear set includes a sun gear connected in series with the rotor to drive its rotation, multiple planetary gears meshing around the sun gear and rotating and revolving as driven, two fixed internal gear rings fixed within the housing to guide the rotation and revolution of the multiple planetary gears, and a receiving ring for the multiple planetary gears. A movable internal gear ring rotates by meshing transmission; the output gear is pivotally mounted inside the housing and located on one side of the movable internal gear ring to receive the meshing transmission of the movable internal gear ring and rotate; its technical feature is that two fixed internal gear rings are spaced apart and located around the periphery of a plurality of planetary gears, the movable internal gear ring is concentrically pivotally mounted between the two fixed internal gear rings, and the outer wall of the movable internal gear ring forms an external tooth portion, the movable internal gear ring meshes with the output gear through the external tooth portion to rotate, so as to output rotational power with a specific reduction ratio to a device demand end.

[0013] The second embodiment of the self-locking reduction drive device differs from the first embodiment in that the motor in the first embodiment is replaced with a geared motor to generate a first-stage reduction ratio of rotational power to drive the compound planetary gear set, so that the compound planetary gear set can generate a second-stage reduction ratio of rotational power, and drive the output gear to output the final rotational power to the equipment demand end.

[0014] The geared motor includes a simple planetary gear set connected to the aforementioned motor drive. This simple planetary gear set includes a simple sun gear connected in series with the rotor and driven to rotate, multiple simple planetary gears meshing around the sun gear and driven to rotate and revolve, and a simple planetary disk pivotally mounted on the multiple simple planetary gears and driven to rotate by the revolution of the multiple simple planetary gears. Furthermore, the compound planetary gear set includes the sun gear coaxially fixed to the simple planetary disk and driven to rotate, generating rotational power for the first reduction ratio. It meshes with the multiple planetary gears in the compound planetary gear set, enabling rotation and revolution under the guidance of two fixed internal gear rings, thereby meshing with the movable internal gear ring to rotate, and driving the output gear via the external teeth to output rotational power for the second reduction ratio used by the equipment.

[0015] Further details of the above two embodiments also include:

[0016] The motor (or the geared motor) and the compound planetary gear set are concentrically arranged along a first axis inside the housing, and the output gear is arranged along a second axis. The first axis and the second axis are parallel to each other and do not collinear.

[0017] The housing also houses an angle sensing assembly comprising a magnetic element and a sensing element. The magnetic element is positioned along the second axis at one end of the output gear, and the sensing element is fixed within the housing along the second axis, maintaining a magnetic gap corresponding to the magnetic element. Furthermore, the housing also houses a drive controller and a sensing circuit board, with the drive controller electrically connected to the sensing circuit board and the motor.

[0018] The device requires an unmanned vehicle, allowing the housing to be installed within it. The output gear is connected to a directional control element of the unmanned vehicle to control its direction or angle of travel or flight. The unmanned vehicle can be a remote-controlled car or a remote-controlled aircraft. When the unmanned vehicle is a remote-controlled car, the directional control element is at least one wheel of the car; when the unmanned vehicle is a remote-controlled aircraft, the directional control element is at least one flap.

[0019] Based on the above-described embodiments, the advantages of this invention over prior art include:

[0020] 1. By leveraging the self-locking function of this composite planetary gear set, power consumption at the demand end of the equipment is reduced, thereby increasing the operating time of the demand end of the equipment.

[0021] 2. The movable internal gear ring, which can output decelerating rotational power, is pivotally mounted between the two fixed internal gear rings, which makes the overall structure of the compound planetary gear set more compact.

[0022] 3. Due to the staggered configuration of the fixed internal gear ring and the movable internal gear ring described above, each planetary gear can generate a stable transmission phenomenon with torque balance and high reduction ratio during its rotation and revolution.

[0023] Furthermore, the implementation details and technical effects disclosed above will be explained in more detail in the following diagrams and implementation methods. Simple Explanation of the Diagram

[0024] Figure 1 is an exploded perspective view of the first embodiment of the present invention. Figure 2 is a planar sectional view of Figure 1. Figure 3 is a three-dimensional exploded view of the second embodiment of the present invention. Figure 4 is a planar sectional view of Figure 3. Implementation

[0025] Please refer to Figures 1 and 2 together, which together disclose a first embodiment of the novel self-locking reduction drive device. It includes a motor 20 and a compound planetary gear set 30 concentrically arranged along a first axis L1 within a housing 10, and an output gear 40 arranged along a second axis L2. "Concentric" means the same axis along the first axis L1, and this axis is the same as the rotation center of the rotor 22. Furthermore, the first axis L1 and the second axis L2 are parallel to each other and collinear. Wherein:

[0026] The housing 10 has a accommodating compartment for installing the self-locking reduction drive device, and can therefore be regarded as the fixed end of the self-locking reduction drive device. In the embodiment shown in Figures 1 and 2, the housing 10 consists of an upper housing 11, a lower housing 13, and a central housing 12 that is segmentally locked between the upper housing 11 and the lower housing 13 by means of a plurality of bolts 15 and 16.

[0027] The motor 20 includes a stator 21 fixed within the central housing 12 and a rotor 22 pivotally mounted within the stator 21. The stator 21 is formed by winding wires to create multiple sets of wires 211 capable of generating a magnetic effect; the rotor 22 is traversed by a first axis L1, and its walls are fitted with at least one polarity pair formed by pairing permanent magnets 221. When a device equipped with the self-locking speed reducer is powered to the wires, the rotor 22 with the polarity pair can rotate under the electromagnetic induction generated by the stator 21, thus serving as the power source for the self-locking speed reducer.

[0028] The composite planetary gear set 30 includes a sun gear 31, multiple planetary gears 32, two fixed internal gear rings 33 and 34, and a movable internal gear ring 35. Wherein:

[0029] The sun gear 31 is columnar with a column portion 311 (as shown in Figure 2) and a sun tooth portion 312. The sun gear 31 forms the rotor 22 by attaching the pair of permanent magnets 221 to the column portion 311. The sun gear 31 is pivotally connected to the housing 10 by bearings 313 and 314 respectively disposed in the upper housing 11 and the middle housing 12, allowing the sun tooth portion 312 of the sun gear 31 to penetrate into the lower housing 13. Thus, when the rotor 22 rotates, it can drive the sun gear 31 with the sun tooth portion 312 to rotate synchronously.

[0030] The plurality of planetary gears 32 may be housed in the lower housing 13, or housed between the middle housing 12 and the lower housing 13, such that the plurality of planetary gears 32 are located on the periphery of the sun gear 31 and mesh with the sun tooth portion 312 of the sun gear 31, thereby being driven by the sun gear 31 to rotate passively and revolve around the sun gear 31.

[0031] The fixed internal gear ring 33 is fixed within the central housing 12 along the first axis L1, and the fixed internal gear ring 34 is also fixed within the lower housing 13 along the first axis L1. This allows the two fixed internal gear rings 33 and 34 to be fixed at intervals within the housing 10 along the first axis L1, and to be spaced apart around the plurality of planetary gears 32. The two fixed internal gear rings 33 and 34 are approximately identical in shape, and each has a plurality of internal teeth surrounding its inner wall for meshing with the plurality of planetary gears 32. This allows the plurality of planetary gears 32 to be arranged at equal angles between the fixed internal gear rings 33 and 34 and the sun gear 31, and when the plurality of planetary gears 32 rotate and revolve around the sun gear 31, the two fixed internal gear rings 33 and 34 provide a stable guiding function.

[0032] The inner wall of the movable internal gear ring 35 is surrounded by a plurality of internal teeth, and its outer wall forms an external tooth portion 351. The movable internal gear ring 35 can be pivotally mounted in the housing 10 by means of the space between the two fixed internal gear rings 33 and 34. In other words, the movable internal gear ring 35 is pivotally mounted between the two fixed internal gear rings 33 and 34 and is located around the periphery of the plurality of planetary gears 32, so that the internal teeth of the movable internal gear ring 35 can mesh with the plurality of planetary gears 32, thereby receiving the meshing transmission of the plurality of planetary gears 32 that can rotate on their own axis and revolve around the sun, and outputting the rotational power of the compound planetary gear set 30 to generate a predetermined reduction ratio.

[0033] The output gear 40 can be made into a stepped wheel shape, and its two ends are respectively equipped with a bearing 401 and 402 along the second axis L2. The bearing 401 is disposed in the middle housing 12, and the bearing 402 is disposed in the lower housing 13, so that the output gear 40 can be pivotally mounted in the housing 10 along the second axis L2 and located on one side of the movable internal gear ring 35, so as to mesh with the outer teeth 351 of the movable internal gear ring 35, and thus receive the transmission of the movable internal gear ring 35 to rotate, and be used as the output end of the self-locking reduction drive device to generate deceleration power.

[0034] In the above implementation, to achieve the self-locking function, the two fixed internal gear rings 33 and 34 must have the same number of internal teeth, and the projection of their tooth profiles onto the first axis L1 must overlap. However, the number of teeth of the two fixed internal gear rings 33 and 34 must not be the same as that of the movable internal gear ring 35. Furthermore, since the two fixed internal gear rings 33 and 34 are arranged on both sides of the movable internal gear ring 35, each planetary gear 32 can generate a torque balance phenomenon during its rotation and revolution, thereby achieving stable transmission and reducing the structural volume.

[0035] Furthermore, as shown in Figures 1 and 2, the self-locking reduction drive device may also include an angle sensing group 50 and a drive controller 60 disposed within the housing 10. Wherein:

[0036] The angle sensing assembly 50 includes at least a magnetic element 52 and a sensing element 53. The magnetic element 52 can be disposed along the second axis L2 at one end of the output gear 40 located in the central housing 12; furthermore, the magnetic element 52 can be first fixed on a mounting base 51, and then fixed at the end of the output gear 40 by the mounting base 51; and the magnetic element 52 can be a magnetized or magnetizable magnet having N poles and S poles (i.e., bipolar orientation).

[0037] The sensing element 53 can be a magnetic encoder that can detect the rotational position and rotational speed of the magnetic element 52, and is fixed in the central housing 12 of the housing 10 along the second axis L2, so that the sensing element 53 can maintain a magnetic gap corresponding to the magnetic element 52.

[0038] Accordingly, the magnetic element 52 can change its bipolar rotational position and speed (i.e., orientation change) as the output gear 40 rotates; the sensing element 53 can be pre-attached to a sensing circuit board 54 using surface mount technology (SMT), so that the sensing element 53 can be fixed in the central housing 12 adjacent to the sensing circuit board 54 in a manner that can sense the orientation change of the magnetic element 52; in other words, the installation position of the sensing element 53 is located within the magnetic field range emitted by the magnetic element 52, so that the present invention can detect the rotation angle output by the output gear 40 based on the configuration details of the angle sensing group 50, and generate an angle signal through the sensing circuit board 54.

[0039] The drive controller 60 can be installed inside the upper housing 11 and is electrically connected to the sensing circuit board 54 and the motor 20 via wires to receive the angle signal sent by the sensing circuit board 54, thereby controlling the motor 20 to output the rotation angle via the output gear 40.

[0040] Based on the above configuration, the multiple planetary gears 32 in the composite planetary gear set 30 can produce a smooth reduction transmission without the need for a conventional planetary gear housing. This effect is particularly significant when the self-locking reduction drive is applied to an unmanned vehicle. Furthermore, the unmanned vehicle (not shown) can be a remote-controlled car or a remote-controlled aircraft. The housing 10 can be fixedly installed inside the unmanned vehicle, allowing the output gear 40 to drive a directional control element (not shown) of the unmanned vehicle. This directional control element can be at least one wheel of the remote-controlled car or at least one flap of the remote-controlled aircraft.

[0041] Accordingly, when the unmanned vehicle equipped with the self-locking reduction drive device is driving or flying normally, the backup power on the unmanned vehicle can drive the motor 20 to rotate via the drive controller 60. The decelerated rotational power is then output through the output gear 40 to control the direction control element to generate a specific yaw direction or angle. The angle sensing group 50 detects the specific yaw direction or angle and feeds it back to the drive controller 60 to precisely control the direction or angle of the unmanned vehicle's driving or flying. Subsequently, the backup power on the unmanned vehicle can be immediately cut off, and the direction control element is locked in the specific yaw direction or angle by means of the self-locking function of the compound planetary gear set 30. This is used to resist the reverse load generated by the direction control element (i.e., the load end) without consuming the unmanned vehicle's continuous power supply to drive the motor 20 to resist the reverse load, thereby saving the unmanned vehicle's power consumption and increasing the unmanned vehicle's operating time.

[0042] In addition, please refer to Figures 3 and 4 together to disclose a second embodiment of the novel self-locking reduction drive device, which is used to increase the reduction ratio of the rotational power output by the output gear 40, so that the equipment demand end (such as the aforementioned unmanned vehicle direction control element) can further fine-tune and control its rotation or yaw direction or angle.

[0043] The difference between this second embodiment and the first embodiment is that the motor 20 shown in Figures 1 and 2 is replaced by a geared motor 200 to generate a first-stage reduction ratio rotational power transmission compound planetary gear set 300. This compound planetary gear set 300 then generates a second-stage reduction ratio rotational power, which is transmitted to the output gear 40 to deliver the final rotational power to the equipment. To this end, the second embodiment also increases the volume of the housing 10 shown in Figures 1 and 2 to accommodate the geared motor 200, so that the central housing 12 shown in Figures 1 and 2 is replaced by a first central housing 120 and a second central housing 130.

[0044] Furthermore, as shown in Figures 3 and 4, the disclosed housing 100 is composed of an upper housing 11, a lower housing 13, and a first central housing 120 and a second central housing 130 that are segmentally locked between the upper housing 11 and the lower housing 13 by means of a plurality of bolts 17 and 18.

[0045] The geared motor 200 includes a rotor 22 of the aforementioned motor 20 connected in series and driving a simple planetary gear set 80 to generate rotational power for the first reduction ratio. Wherein:

[0046] The simple planetary gear set 80 includes: a simple sun gear 81 connected in series with the rotor 22 and driven to rotate; a plurality of simple planetary gears 82 meshing around the simple sun gear 81 and driven to rotate and revolve; a simple planetary disk 83 providing pivot for the plurality of simple planetary gears 82 and receiving the drive of the plurality of simple planetary gears 82 to rotate; and a simple ring gear 84 fixed in the housing 100 and guiding the rotation and revolution of the plurality of simple planetary gears 82, so that the simple planetary gear set 80 can generate rotational power with the first reduction ratio from the simple planetary disk 83.

[0047] The motor 20 can be fixed within the first central housing 120, and the simple sun gear 81 is pivotally connected to the housing 10 by bearings 313 and 314 respectively disposed within the upper housing 11 and the first central housing 120. The simple sun gear 81 is axially shaped with a column portion 811 and a sun tooth portion 812. The simple sun gear 81 becomes the rotor 22 by attaching a pair of permanent magnets 221 to the column portion 811. The sun tooth portion 812 of the simple sun gear 81 can extend into the second central housing 130. The second central housing 130 can provide a simple ring gear 84 for fixing and guiding the plurality of simple planetary gears 82 and the simple planetary disk 83. The fixed internal gear ring 33 can be fixedly placed inside the second central housing 130, and the fixed internal gear ring 34 is fixedly placed inside the lower housing 13, so that the plurality of planetary gears 32 can be located between the second central housing 130 and the lower housing 13 and be guided by the two fixed internal gear rings 33 and 34, thereby driving the movable internal gear ring 35 to rotate.

[0048] Furthermore, in this embodiment, the sun gear 36 of the composite planetary gear set 300 is not fixed to the rotor 22 as in the first embodiment (as shown in Figures 1 and 2), but is fixed to the simple planetary disk 83 along the first axis L1 (as shown in Figures 3 and 4) to receive the first stage reduction ratio rotational power generated by the simple planetary disk 83, so that the composite planetary gear set 300 can further generate the second stage reduction ratio rotational power, thereby transmitting the output gear 40 to output the final rotational power, so as to meet the device's demand for fine-tuning and control of its rotation or yaw direction or angle.

[0049] In this compound planetary gear set 300, except for the slight difference in the configuration of the sun gear 36 compared to the first embodiment, the transmission configurations of the fixed internal gear rings 33 and 34, the planetary gear 32, and the movable internal gear ring 35 described above can all be implemented by referring to the description of the first embodiment. Furthermore, the components and structures not explained or detailed in the second embodiment can all be equally interpreted and applied from the content already described in the first embodiment.

[0050] The above two embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, the present invention should be subject to the claims defined in the patent application.

[0051] 10,100: Vessel shell 11: Upper shell 12: Centrally mounted housing 120: First centrally located housing 13: Lower shell 130: Second central housing 15, 16, 17, 18: Bolts 20: Motor 200: Gear motor 21: Stator 211: Line Set 22: Rotor 221: Permanent magnet 30, 300: Compound planetary gear set 31, 36: Sun Gear 311: Column 312: Solar tooth 313, 314: Bearings 32: Planetary Gears 33, 34: Fixed internal gear ring 35: Movable internal gear ring 351: External teeth 40: Output gear 401, 402: Bearings 50: Angle Sensing Group 51: Configuration Seat 52: Magnetic components 53: Sensing element 54: Sensing circuit board 60: Drive Controller 80: Simple Planetary Gear Set 81: Simple Sun Gear 811: Column 812: Solar tooth 82: Simple Planetary Gears 83: Simple Planetary Wheel 84: Simple Ring Gear L1: First axis line L2: Second axis line

Claims

1. A self-locking speed reduction drive device, comprising: (The following is a description of the device's components, which are not directly related to the main point about speed reduction.) A motor includes a stator fixed within a housing and a rotor pivotally mounted within the stator and rotating under electromagnetic induction. A compound planetary gear set includes a sun gear connected in series with the rotor to drive its rotation, multiple planetary gears meshing around the sun gear and rotating and revolving as driven, two fixed internal gear rings fixed within the housing to guide the rotation and revolution of the multiple planetary gears, and a movable internal gear ring rotating under the meshing transmission of the multiple planetary gears; and a power gear pivotally mounted within the housing and situated on one side of the movable internal gear ring, rotating under the meshing transmission of the movable internal gear ring. The two fixed internal gear rings are spaced apart and positioned around the periphery of the multiple planetary gears. The movable internal gear ring is concentrically pivotally mounted between the two fixed internal gear rings, and its outer wall forms an external tooth portion. The movable internal gear ring meshes with the power gear through this external tooth portion to rotate.

2. The self-locking speed reduction drive as claimed in claim 1, wherein the motor and the compound planetary gear set are concentrically arranged within the housing along a first axis, and the output gear is arranged along a second axis, the first axis and the second axis being parallel to each other and excluding collinearity.

3. The self-locking reduction drive as claimed in claim 2, wherein the housing further includes an angle sensing group comprising a magnetic element and a sensing element, the magnetic element being disposed at one end of the output gear along the second axis, and the sensing element being fixedly disposed within the housing along the second axis and having a magnetic gap corresponding to the magnetic element.

4. The self-locking speed reduction drive as claimed in claim 3, wherein a drive controller and a sensing circuit board are further installed inside the housing, and the drive controller is electrically connected to the sensing circuit board and the motor.

5. A self-locking reduction drive device, comprising: (The following is a description of the device's components, which is not directly related to the preceding text and can be omitted.) A geared motor includes a motor and a simple planetary gear set. The motor includes a stator fixed within a housing and a rotor pivotally mounted within the stator and rotating under electromagnetic induction. The simple planetary gear set includes a simple sun gear connected in series with the rotor to drive its rotation, a plurality of simple planetary gears meshing around the simple sun gear and rotating and revolving thereafter, and a simple planetary disk pivotally mounted on the plurality of simple planetary gears and rotating under the influence of the revolution of the plurality of simple planetary gears. A compound planetary gear set includes a sun gear coaxially fixed to the simple planetary disk and rotating thereafter, a plurality of planetary gears meshing around the sun gear and rotating and revolving thereafter, two fixed internal gear rings fixed within the housing to guide the rotation and revolution of the plurality of planetary gears, and a movable internal gear ring rotating under the meshing transmission of the plurality of planetary gears; and an output gear pivotally mounted within the housing and located on one side of the movable internal gear ring for rotating under the meshing transmission of the movable internal gear ring. The two fixed internal gear rings are spaced apart and located around the periphery of the plurality of planetary gears. The movable internal gear ring is concentrically pivoted between the two fixed internal gear rings, and the outer wall of the movable internal gear ring forms an external tooth portion. The movable internal gear ring drives the output gear to rotate by meshing with the external tooth portion.

6. The self-locking reduction drive device as claimed in claim 5, wherein the reduction motor and the compound planetary gear set are concentrically arranged within the housing along a first axis, and the output gear is arranged along a second axis, the first axis and the second axis being parallel to each other and excluding collinearity.

7. The self-locking reduction drive as claimed in claim 6, wherein the housing further includes an angle sensing group comprising a magnetic element and a sensing element, the magnetic element being disposed at one end of the output gear along the second axis, and the sensing element being fixedly disposed within the housing along the second axis and having a magnetic gap corresponding to the magnetic element.

8. The self-locking speed reduction drive as claimed in claim 7, wherein a drive controller and a sensing circuit board are further installed inside the housing, and the drive controller is electrically connected to the sensing circuit board and the motor.

9. The self-locking reduction drive as claimed in claim 1 or 5, wherein the housing is mounted inside an unmanned vehicle, and the output gear is connected to a directional control element of the unmanned vehicle.

10. The self-locking deceleration drive as claimed in claim 9, wherein the unmanned vehicle is a remote-controlled vehicle and the direction control element is at least one wheel of the remote-controlled vehicle.

11. The self-locking deceleration drive as claimed in claim 9, wherein the unmanned vehicle is a remotely controlled aircraft, and the direction control element is at least one flap of the remotely controlled aircraft.

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