A dynamic balancing device for a motor of a drone

Abstract

The utility model discloses a kind of unmanned vehicle motor dynamic balancing device, including shell, first motor and fan blade, the shell upper end is equipped with first motor, and first motor is equipped with the first output shaft of connecting fan blade;The bottom of the shell is equipped with control circuit board, and microcontroller is equipped on control circuit board;The internal cavity of the shell is equipped with the fixed plate connected with first motor;The lower end of the fixed plate is connected with second motor, and second motor is equipped with second output shaft, and second output shaft is connected with counterweight, and the lower end of counterweight is connected with sliding block;The lower end of second motor is equipped with annular base, and annular base is equipped with annular slide rail, and annular slide rail is slidably connected with the sliding block;The lower end of annular base is equipped with a group of vibration sensors, and microcontroller is electrically connected with second motor and vibration sensor respectively.The utility model can monitor high-frequency vibration in real time and compensate dynamic unbalance generated by single motor, with the advantages of compact structure and good integration.

Description

Technical Field

[0001] This utility model belongs to the field of unmanned aerial vehicle (UAV) technology, and in particular relates to a dynamic balancing device for UAV motors. Background Technology

[0002] The stable operation of the drone's propulsion system is fundamental to ensuring the achievement of its various performance indicators. However, the dynamic imbalance generated by the motor and its driven propeller during high-speed rotation has always been a major technical challenge hindering the design and application of drones. In the prior art, Chinese invention patent CN110217381A discloses a dynamic counterweight balancing system and its balancing method for drone stabilization. The core solution involves installing a fixed frame at the bottom of the drone, on which are arranged parallel positive and negative conductive racks and sliding resistor plates. A "movable counterweight" (including a micro DC motor, a counterweight motor sleeve, a metal gear ring, etc.) can roll on these racks. When the drone's reference plane is not horizontal (i.e., tilted), the movable counterweight slides downwards due to gravity. This change in position is reflected on the sliding resistor plate through the sliding resistor contact driven by the connecting rod, thereby changing the voltage detected by the control circuit. The control circuit calculates the position, velocity, and acceleration of the movable counterweight based on voltage changes, thereby inferring the drone's tilt angle and driving a miniature DC motor to adjust the movable counterweight to a new equilibrium position, restoring the drone's reference plane to horizontal. This system aims to counteract attitude instability caused by load changes or external disturbances by altering the drone's overall center of gravity. However, this invention balances the entire drone, aiming to adjust its overall center of gravity to maintain attitude balance. This approach may lack the specificity and real-time capability to compensate for the dynamic imbalance torque generated by a single high-speed rotating motor and the resulting high-frequency vibrations. Furthermore, the invention's structure may be relatively complex and space- and weight-intensive, making it more suitable for applications highly sensitive to load changes and requiring significant center of gravity adjustments, such as large or specialized mission drones. Therefore, its structure is not compact or lightweight enough. Utility Model Content

[0003] The purpose of this invention is to provide a dynamic balancing device for drone motors. This invention can monitor high-frequency vibrations in real time and compensate for the dynamic imbalance generated by a single motor, and has the advantages of compact structure and good integration.

[0004] The technical solution of this utility model is as follows: A dynamic balancing device for a drone motor includes a housing, a first motor, and fan blades. The first motor is located at the upper end of the housing and has a first output shaft connected to the fan blades. A control circuit board is located at the bottom of the housing, and a microcontroller is located on the control circuit board. A fixing plate connected to the first motor is located in the internal cavity of the housing. A second motor is connected to the lower end of the fixing plate. The second motor has a second output shaft, and a counterweight is connected to the second output shaft. A slider is connected to the lower end of the counterweight. An annular base is located at the lower end of the second motor, and an annular slide rail is located on the annular base. The annular slide rail slides in cooperation with the slider. A set of vibration sensors is located at the lower end of the annular base. The microcontroller is electrically connected to the first motor, the second motor, and the vibration sensors.

[0005] In the aforementioned dynamic balancing device for UAV motors, the fixed plate is provided with multiple first through holes, the bottom of the first motor is provided with multiple first threaded holes that mate with the through holes, and the bottom of the second motor is provided with multiple second threaded holes that mate with the first through holes; the first through hole is provided with a double-ended bolt whose two ends are respectively threaded to the first threaded hole and the second threaded hole.

[0006] In the aforementioned dynamic balancing device for UAV motors, a connecting rod connected to a counterweight is provided on the side of the second output shaft.

[0007] In the aforementioned dynamic balancing device for UAV motors, the bottom of the counterweight is provided with multiple third threaded holes, and the slider is provided with multiple fourth threaded holes that mate with the third threaded holes. The counterweight and the slider are connected by screw threads.

[0008] In the aforementioned dynamic balancing device for UAV motors, the slider is provided with multiple mounting holes, and a screw is inserted through the mounting holes. A pulley that is rotatably engaged with the annular slide rail is mounted on the screw. One end of the screw is located on one side of the pulley, and the other end of the screw is fixed in the mounting hole by a washer and a nut.

[0009] In the aforementioned dynamic balancing device for drone motors, the bottom of the slider is also provided with a pair of limiting components that cooperate with the annular slide rail.

[0010] In the aforementioned dynamic balancing device for UAV motors, the vibration sensors are symmetrically distributed at the lower end of the annular base.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] This invention achieves a stable connection between the first and second motors via double-ended bolts, along with a ring base, ring slide rail, and compact counterweight drive system, realizing a relatively miniaturized and modular balancing unit. This invention uses vibration sensors to monitor the vibration parameters of the first motor in real time. Once the vibration parameters reach a trigger threshold, the microcontroller immediately sends a signal to the second motor to drive the counterweight block to move to the compensation position on the ring slide rail, thus achieving real-time compensation and effectively suppressing the dynamic imbalance and high-frequency vibration of the first motor itself (especially at high speeds). Furthermore, this invention symmetrically distributes vibration sensors at the lower end of the ring base, which helps to collect more comprehensive and accurate vibration information of the first motor in different directions. Attached Figure Description

[0013] Figure 1 This is a diagram of the internal structure of this utility model;

[0014] Figure 2 This is a cross-sectional view of the present invention;

[0015] Figure 3 This is a partial view A of the present invention;

[0016] Figure 4 This is a cross-sectional view of the limiting component of the annular base of this utility model;

[0017] Figure 5 This is a partial view B of the present invention;

[0018] Figure 6 This is a cross-sectional view of the mounting hole of the annular base of this utility model;

[0019] Figure 7 This is a partial view C of the present invention.

[0020] The labels in the attached diagram are as follows: 1. Housing; 2. Annular base; 3. Fan blade; 4. First motor; 5. First output shaft; 6. Control circuit board; 7. Microcontroller; 8. Fixing plate; 9. Second motor; 10. Second output shaft; 11. Counterweight; 12. Slider; 13. Limiting component; 14. Annular slide rail; 15. Vibration sensor; 16. Connecting rod; 17. First through hole; 18. First threaded hole; 19. Second threaded hole; 20. Double-ended bolt; 21. Third threaded hole; 22. Fourth threaded hole; 23. Mounting hole; 24. Screw; 25. Pulley. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0022] Example: A dynamic balancing device for a drone motor, configured as follows Figure 1 and Figure 2 As shown, the device includes a housing 1, a first motor 4, and fan blades 3. The first motor 4 is located at the upper end of the housing 1, and the first motor 4 has a first output shaft 5 connected to the fan blades 3. The first motor 4 is a 2212 type brushless DC motor with a power of 100-300W. The first output shaft 5 has a diameter of 3-5mm and is fixedly connected to the fan blades 3 via a keyway. The speed range is 5000-12000rpm. The housing 1 is made of aerospace-grade aluminum alloy or carbon fiber composite material with a thickness of 2-3mm and an anodized surface, combining lightweight (overall weight ≤150g) and vibration resistance. The housing 1 is cylindrical with an inner diameter of 50-80mm and a height of 40-60mm. The bottom is closed and integrates a control circuit board 6. The control circuit board 6 has a microcontroller 7, which uses an STM32F405RG chip. The internal cavity of the housing 1 is equipped with a fixing plate 8 connected to the first motor 4. The lower end of the fixing plate 8 is connected to a second motor 9. The second motor 9 is a micro servo motor (such as a 20mm diameter hollow cup motor) with a rated torque of 0.1-0.3 N·m and a speed range of 0-300 rpm. The fixing plate 8 is made of 6061-T6 aluminum alloy plate, 4-6mm thick, with a milled mounting surface matching the first motor 4 and the second motor 9. Specifically, the fixing plate 8 has four evenly distributed first through holes 17 with an M4 diameter and a hole spacing conforming to motor installation standards. The bottom of the first motor 4 has four first threaded holes 18 that mate with the through holes, and the bottom of the second motor 9 has four second threaded holes 19 that mate with the first through holes 17. The first through holes 17 are equipped with double-ended bolts 20, each threaded to the first threaded holes 18 and 19 respectively. The M4×20mm double-ended bolts 20 penetrate the first through holes 17 to achieve a rigid connection between the upper and lower motors, with a tightening torque of 1.5-2 N·m.

[0023] The second motor 9 is equipped with a second output shaft 10, which is connected to a counterweight 11. A slider 12 is connected to the lower end of the counterweight 11. The counterweight 11 is made of tungsten steel or copper alloy with a density ≥8 g / cm³. 3 The weight can be adapted to different motor loads by changing different specifications (such as 50g, 100g, 150g). Specifically, the second output shaft 10 has a connecting rod 16 welded to the counterweight 11 on its side. The lower end of the second motor 9 has an annular base 2, and an annular slide rail 14 is provided on the annular base 2, which slides in cooperation with the slider 12. Figure 3 and Figure 4As shown, the outer diameter of the slider 12 is clearance-fitted with the inner diameter of the annular slide rail 14 (clearance 0.1-0.2mm). Two symmetrical limiting members 13, with a T-shaped cross-section, are machined at the bottom to fit into the T-groove of the annular slide rail 14, preventing the slider 12 from dislodging. A set of vibration sensors 15 is provided at the lower end of the annular base 2. The microcontroller 7 is electrically connected to the first motor 4, the second motor 9, and the vibration sensors 15. The vibration sensors 15 are connected via I... 2 The C-bus communicates with the microcontroller 7. The second motor 9 is connected to the microcontroller 7 through an H-bridge drive circuit (such as L298N). The power supply is provided by the drone's main battery (11.1V / 2200mAh), with a power consumption of ≤5W.

[0024] like Figure 5 and Figure 6 As shown, the bottom of the counterweight 11 is provided with eight third threaded holes 21, and the slider 12 is provided with eight fourth threaded holes 22 that mate with the third threaded holes 21. The counterweight 11 and the slider 12 are connected by M3×8mm screws to the third threaded holes 21 and the fourth threaded holes 22, which facilitates quick disassembly and replacement.

[0025] like Figure 7 As shown, the slider 12 has six evenly distributed mounting holes 23, each with a diameter of φ5mm. A φ4mm screw 24 is inserted into each hole 23, and the screw 24 is rotatably fitted onto the screw 24, slidingly engaging with the annular slide rail 14. One end of the screw 24 is located on one side of the pulley 25, and the other end is fixed in the mounting hole 23 by a washer and a nut. Both ends of the screw 24 pass through the center hole of the pulley 25 and the mounting hole 23, respectively, and are fixed by an M4 washer and a nut. The pulley 25 uses a 608ZZ deep groove ball bearing, with its outer ring in contact with the inner surface of the annular slide rail 14. The coefficient of friction is ≤0.001, ensuring smooth sliding.

[0026] The vibration sensors 15 are symmetrically distributed at the lower end of the annular base 2. The vibration sensors 15 are arranged in two symmetrical configurations. These sensors are commercially available; for example, the VTall-N-T163R vibration sensor from Weituo Information Technology Co., Ltd. can be used. It is primarily used to monitor vibration acceleration, vibration velocity, and vibration displacement. It is fixed to the bottom of the housing 1 with countersunk screws, and has a sampling frequency of 3Hz-3000Hz, capable of simultaneously acquiring X, Y, and Z-axis vibration data.

[0027] This invention achieves a stable connection between the first motor 4 and the second motor 9 via a double-ended bolt 20, along with the annular base 2, annular slide rail 14, and a compact counterweight drive system, realizing a relatively miniaturized and modular balancing unit. This invention uses a vibration sensor 15 to monitor the vibration parameters of the first motor 4 in real time. Once the vibration parameters reach a trigger threshold, the microcontroller 7 immediately sends a signal to the second motor 9 to drive the counterweight block 11 to move to the compensation position on the annular slide rail 14, thereby achieving real-time compensation and effectively suppressing the dynamic imbalance and high-frequency vibration of the first motor 4 itself (especially at high speeds). Furthermore, this invention symmetrically distributes the vibration sensors 15 at the lower end of the annular base 2, which helps to collect vibration information of the first motor 4 in different directions more comprehensively and accurately.

[0028] Work process

[0029] When the first motor 4 drives the fan blade 3 to rotate at high speed, radial vibration will occur if dynamic imbalance occurs (such as blade wear or assembly errors). The vibration sensor 15 monitors the vibration parameters of the first motor 4 in real time. After the vibration parameters reach the trigger threshold, the microcontroller 7 immediately sends a signal to the second motor 9 to drive the counterweight 11 to rotate along the annular slide rail 14. The pulley 25 reduces frictional resistance, and the limiting component 13 ensures the stability of the motion trajectory. When the counterweight 11 reaches the target position, the centrifugal force it generates cancels out the motor's unbalanced force, and the vibration parameters drop below the set threshold (e.g., ≤0.5g), achieving dynamic balance.

[0030] In summary, this invention can monitor high-frequency vibration in real time and compensate for the dynamic imbalance generated by a single motor, and has the advantages of compact structure and good integration.

Claims

1. A dynamic balancing device for a drone motor, comprising a housing (1), a first motor (4), and a fan blade (3), wherein the housing (1) is provided with the first motor (4) at its upper end, and the first motor (4) is provided with a first output shaft (5) connected to the fan blade (3); the housing (1) is provided with a control circuit board (6) at its bottom, and a microcontroller (7) is provided on the control circuit board (6); characterized in that: The internal cavity of the housing (1) is provided with a fixing plate (8) connected to the first motor (4); the lower end of the fixing plate (8) is connected to a second motor (9), the second motor (9) is provided with a second output shaft (10), the second output shaft (10) is connected to a counterweight (11), the lower end of the counterweight (11) is connected to a slider (12); the lower end of the second motor (9) is provided with an annular base (2), the annular base (2) is provided with an annular slide rail (14), the annular slide rail (14) is slidably engaged with the slider (12); the lower end of the annular base (2) is provided with a set of vibration sensors (15), and the microcontroller (7) is electrically connected to the first motor (4), the second motor (9) and the vibration sensors (15) respectively.

2. The UAV motor dynamic balancing device according to claim 1, characterized in that: The fixing plate (8) is provided with a plurality of first through holes (17), the bottom of the first motor (4) is provided with a plurality of first threaded holes (18) that cooperate with the through holes, and the bottom of the second motor (9) is provided with a plurality of second threaded holes (19) that cooperate with the first through holes (17); the first through hole (17) is provided with a double-ended bolt (20) whose two ends are respectively threaded to the first threaded hole (18) and the second threaded hole (19).

3. The dynamic balancing device for UAV motors according to claim 1, characterized in that: The second output shaft (10) has a connecting rod (16) on its side that is connected to the counterweight (11).

4. The UAV motor dynamic balancing device according to claim 1, characterized in that: The counterweight (11) has multiple third threaded holes (21) at its bottom, and the slider (12) has multiple fourth threaded holes (22) that mate with the third threaded holes (21). The counterweight (11) and the slider (12) are connected by screw threads to the third threaded holes (21) and the fourth threaded holes (22).

5. The dynamic balancing device for UAV motors according to claim 1, characterized in that: The slider (12) is provided with multiple mounting holes (23), and a screw (24) is inserted into the mounting hole (23). A pulley (25) is rotatably fitted on the screw (24) and slides with the annular slide rail (14). One end of the screw (24) is set on one side of the pulley (25), and the other end of the screw (24) is fixed in the mounting hole (23) by a washer and a nut.

6. The UAV motor dynamic balancing device according to claim 1, characterized in that: The bottom of the slider (12) is also provided with a pair of limiting members (13) that cooperate with the annular slide rail (14).

7. The dynamic balancing device for UAV motors according to claim 1, characterized in that: The vibration sensors (15) are symmetrically distributed at the lower end of the annular base (2).

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