Low noise servo

Abstract

The utility model is suitable for mechanical control technical field provides a kind of low noise steering engine, including shell assembly, shell assembly includes mutually matched connection's upper cover, middle frame and base, jointly form closed containing cavity;Drive assembly, drive assembly is located inside containing cavity, including reduction gear set and DC motor, the output shaft of DC motor is engaged with reduction gear set and is connected;Control component, control component is located inside containing cavity, including PCB board and drive IC and noise reduction IC integrated on PCB board;Potentiometer, potentiometer is located inside containing cavity, potentiometer is electrically connected with control component, and potentiometer is coaxially connected with reduction gear set;Contact microphone, contact microphone is located inside containing cavity;Loudspeaker, loudspeaker is fixedly installed in the base.The utility model provides low noise steering engine structure compact, help to reduce the volume and weight of steering engine, reduce the noise when motor operation, realize low noise, high reliability steering engine performance.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical control technology, and in particular relates to a low-noise servo motor. Background Technology

[0002] Servo motors, as precision actuators widely used in robotics, drones, and remote-controlled models, directly impact the stability and accuracy of the entire system. However, traditional servo motors often generate significant noise during operation, which not only affects the user experience but may also adversely impact the long-term operational stability of the equipment.

[0003] One of the main sources of noise from servo motors is the motor itself. Since the motor is usually exposed and in direct contact with the housing, the noise from its operation is amplified further by the housing. Furthermore, as a core drive component in robots, aircraft, and industrial equipment, the noise of servo motors directly impacts user experience and equipment concealment. Traditional noise reduction solutions often rely on improving mechanical structures (such as helical gear design and damping material filling) or optimizing motor control algorithms. However, these methods are limited by the physical properties of materials, offering limited effectiveness in suppressing broadband noise (such as high-frequency electromagnetic noise from motors and low-frequency impacts from gears), and also increase equipment size and cost. Utility Model Content

[0004] The purpose of this invention is to provide a low-noise servo motor, thereby suppressing the noise source of the servo motor and ensuring the compactness and reliability of the servo motor structure.

[0005] In a first aspect, this utility model provides a low-noise servo motor, comprising:

[0006] The housing assembly includes a top cover, a middle frame, and a base that fit together to form a sealed receiving cavity;

[0007] A drive assembly, located inside the receiving cavity, includes a reduction gear set and a DC motor, wherein the output shaft of the DC motor is meshed with the reduction gear set.

[0008] A control component, which is located inside the receiving cavity, includes a PCB board and a driver IC and a noise reduction IC integrated on the PCB board;

[0009] A potentiometer is located inside the receiving cavity, at the midpoint between the control component and the reduction gear set. The potentiometer is electrically connected to the control component and coaxially connected to the reduction gear set. It is used to detect the rotation angle of the servo motor in real time and output a feedback signal.

[0010] A contact microphone, located inside the receiving cavity, is used to collect noise generated by the operation of the DC motor;

[0011] A loudspeaker, which is fixedly mounted on the base, is used to output anti-phase sound waves;

[0012] The driver IC is used to receive external control commands and control the operation of the DC motor according to the feedback signal output by the potentiometer, forming a closed-loop control system. The noise reduction IC is used to receive the noise signal collected by the contact microphone, and generate an anti-phase sound wave control signal after filtering and analog-to-digital conversion.

[0013] In some embodiments, the top cover is a three-layer composite structure. The first layer is teardrop-shaped with an output shaft through hole in the middle. The through hole is coaxially arranged with the output shaft of the reduction gear set and is used for the output shaft to pass through and connect to the outside. The second and third layers are designed in a stepped stacked manner. The third layer has mounting holes symmetrically arranged on both sides. The mounting holes are used for the fixed installation of the servo motor.

[0014] In some embodiments, the middle frame has a rectangular frame structure and is connected to the upper cover and the base respectively. The middle frame is provided with a partition sidewall, and the axial length of the partition sidewall is equal to the sum of the height of the middle frame and the height of the base.

[0015] In some embodiments, the partition sidewall divides the middle frame into a first independent chamber and a second independent chamber that are not interconnected, wherein the first independent chamber is used to house the control components and potentiometer, the second independent chamber is used to house the DC motor, and the contact microphone is disposed on the partition sidewall.

[0016] In some embodiments, the bottom of the partition sidewall is provided with an opening for the access of the drive line of the DC motor.

[0017] In some embodiments, the reduction gear set includes a primary gear, a driven gear, and a final gear. The primary gear is meshed with the output shaft of the DC motor. The driven gear meshes with the primary gear and rotates, and is coaxially connected to the shaft of the potentiometer via a coupling structure. The final gear meshes with the driven gear and rotates, and its output shaft extends to the outside of the housing assembly for connection with external components.

[0018] In some embodiments, a damping membrane is adhered to the side of the partition sidewall and the inner surface of the base.

[0019] In some embodiments, the damping membrane has a sound absorption coefficient greater than 0.5 and a thickness of 50µm-200µm, and is used to absorb and isolate the mechanical vibration noise generated during the operation of the DC motor.

[0020] In some embodiments, a steering disk is also included, which is connected to the output shaft of the final stage gear via a keyway structure, for transmitting the rotational motion of the output shaft to external mechanical components.

[0021] In some embodiments, four support rods are also included, which are respectively vertically arranged at the four corners of the housing assembly for connecting and fixing the top cover, the middle frame and the base.

[0022] This invention provides a low-noise servo, comprising a housing assembly, a drive assembly, a control assembly, a potentiometer, a contact microphone, and a speaker. The drive assembly includes a reduction gear set and a motor, while the control assembly includes a PCB board and a drive IC and a noise reduction IC integrated on a PVB board. This invention uses a contact microphone to collect noise signals from a DC motor in real time. After processing by the noise reduction IC, it generates anti-phase sound waves with opposite phases. Utilizing the principle of sound wave interference, it directly cancels out the noise source, thereby achieving active noise reduction during servo operation, reducing motor noise, and achieving low-noise, high-reliability servo performance. Furthermore, by integrating the noise reduction IC and drive IC onto the servo's PCB board and placing the contact microphone and speaker inside the servo, it does not occupy additional space, helping to reduce the servo's size and weight and ensuring a compact structure. Attached Figure Description

[0023] Figure 1 This is a perspective view of a low-noise servo motor provided by this utility model;

[0024] Figure 2 This is a partial schematic diagram of a low-noise servo motor provided by this utility model;

[0025] Figure 3 This is another partial schematic diagram of a low-noise servo motor provided by this utility model;

[0026] Figure 4 This is an exploded view of a low-noise servo motor provided by this utility model;

[0027] Figure 5 This is a schematic diagram of the top cover of a low-noise servo motor provided by this utility model;

[0028] Figure 6 This is a schematic diagram of the mid-frame of a low-noise servo motor provided by this utility model;

[0029] Figure 7 This is a schematic diagram of a reduction gear set for a low-noise servo motor provided by this utility model;

[0030] Figure 8 This is a schematic diagram of a low-noise servo motor control component provided by this utility model; Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0032] It should be noted that the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to direct setup or connection, or indirect setup or connection through centered components or centered structures.

[0033] Furthermore, in embodiments of this utility model, terms such as "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or in a conventional placement or usage state. These terms are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the structure, feature, device, or element referred to must have a specific orientation or positional relationship, nor that it must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0034] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the various specific technical features / embodiments in this utility model will not be described separately.

[0035] This utility model provides a low-noise servo motor 1. Please refer to the following: Figures 1 to 8The servo motor 1 includes a housing assembly 10, a drive assembly 20, a control assembly 30, a potentiometer 40, a contact microphone 50, and a speaker 60. The housing assembly 10 includes a top cover 11, a middle frame 12, and a base 13 that are interconnected to form a sealed housing cavity. The drive assembly 20 is located inside the housing cavity and includes a reduction gear set 21 and a DC motor 22. The output shaft of the DC motor 22 is meshed with the reduction gear set 21. The control assembly 30 is located inside the housing cavity and includes a PCB board 31 and a drive IC 32 and a noise reduction IC 33 integrated on the PCB board 31. The drive IC 32 and the noise reduction IC 33 are arranged adjacent to each other on the PCB 31. The potentiometer 40 is located inside the housing cavity, positioned between the control assembly 30 and the reduction gear set 21. The potentiometer 40 is electrically connected to the control assembly 30 and coaxially connected to the reduction gear set 22, used to detect the rotation angle of the servo motor in real time and output a feedback signal. A contact microphone 50 is also located inside the housing cavity to collect noise generated by the operation of the DC motor 22. A speaker 60 is fixedly mounted on the base 13 to output inverted sound waves. The driver IC 32 receives external control commands and controls the operation of the DC motor 22 based on the feedback signal output from the potentiometer 40, forming a closed-loop control system. The noise reduction IC 33 receives the noise signal collected by the contact microphone 50, filters it, and converts it to digital signal to generate an inverted sound wave control signal. The low-noise servo 1 provided in this embodiment has a compact structure, which helps to reduce the size and weight of the servo, lowers the noise during motor operation, and achieves low-noise, high-reliability servo performance.

[0036] In some embodiments, the housing assembly 10 includes an upper cover 11, a middle frame 12, and a base 13 that are connected to each other to form a sealed receiving cavity. Specifically, the upper cover 11 has a three-layer composite structure. The first layer 111 has a teardrop shape and an output shaft through hole 1111 in the middle. The through hole 1111 is coaxially arranged with the output shaft of the reduction gear set 21, so that the output shaft of the reduction gear set 21 can pass through the upper cover 11 for the output shaft to pass through and connect to the outside. The second layer 112 and the third layer 113 have a stepped stacked design. The third layer 113 has mounting holes 1131 symmetrically arranged on both sides. The mounting holes 1131 are used for the fixed installation of the servo motor to achieve stable installation of the servo motor 1.

[0037] The middle frame 12 is roughly rectangular in shape and is connected to both the upper cover 11 and the base 13. The middle frame 12 has a partition sidewall 121, located slightly to the right of the center inside, which effectively divides the internal space of the middle frame 12. The axial length of the partition sidewall 121 is equal to the sum of the height of the middle frame 12 and the height of the base 13, ensuring that its bottom fits snugly against the inner surface of the base 13, thus achieving a stable structural connection. Furthermore, the bottom of the partition sidewall 121 has an opening 1211 for the drive wire of the DC motor 22 to be connected, ensuring a smooth wiring connection.

[0038] The base 13 has a rectangular parallelepiped structure with an opening on its upper surface. The size of the opening perfectly matches the bottom of the middle frame 12, allowing the base 13 to fit tightly with the middle frame 12 to form a complete housing. The housing assembly 10 provides stable support and reliable installation space for each component, ensuring the stability and reliability of the entire servo motor 1 during operation.

[0039] In some embodiments, the partition sidewall 121 divides the middle frame 12 into a first independent chamber and a second independent chamber that are not interconnected. The first independent chamber has a slightly larger volume than the second independent chamber. The first independent chamber is used to house the control assembly 30 and the potentiometer 40, while the second independent chamber is used to house the DC motor 22. Dividing the space according to the different functions of the devices optimizes functional zoning, making the internal structure of the entire device more compact and efficient.

[0040] In some embodiments, the drive assembly 20 is disposed inside the receiving cavity and includes a reduction gear set 21 and a DC motor 22, the output shaft of the DC motor 22 being meshed with the reduction gear set 21. The reduction gear set 21 consists of a plurality of gears of different types and a gear shaft that assembles these gears together.

[0041] Specifically, the reduction gear set 21 includes a primary gear 211, a driven gear 212, and a final gear 213. The primary gear 211 meshes with the output shaft of the DC motor 22. The driven gear 212 meshes with the primary gear 211 and rotates, and is coaxially connected to the shaft of the potentiometer 40 via a coupling structure. The final gear 213 meshes with the driven gear 212 and rotates, and its output shaft extends to the outside of the housing assembly 10 for connection to external components. The primary gear 211 of the reduction gear set 21 is connected to the DC motor 22, responsible for introducing the power of the DC motor 22 into the reduction gear set 21. The driven gear 212 is connected to the potentiometer 40 for precise speed feedback and control. The output shaft of the final gear 213 extends to the outside and connects to external components, thereby efficiently transmitting the reduced power to subsequent equipment.

[0042] Specifically, the DC motor 22 is installed inside the second independent cavity, and its output shaft is tightly coupled to the first gear 211 of the reduction gear set 21 via a coaxial connection. The DC motor 22 serves as a power source to precisely drive the reduction gear set 21.

[0043] In some embodiments, the control component 30 is disposed inside the receiving cavity, including a PCB board 31 and a driver IC 32 and a noise reduction IC 33 integrated on the PCB board 31. The driver IC 32 and the noise reduction IC 33 are arranged side by side adjacent to each other on the PCB board 31. Specifically, the PCB board 31 serves as the basic carrier, integrating various electronic components and circuits to provide electrical connections and physical support for the driver IC 32 and the noise reduction IC 33, thereby enabling signal transmission between various circuits. The driver IC 32, integrated on the PCB board 31, is used to receive external control commands and control the operation of the DC motor 22 according to the feedback signal output by the potentiometer 40, forming a closed-loop control system. The driver IC 32 has a built-in control algorithm and power amplifier circuit. When it receives an external control command (such as a speed setting signal), it compares it with the actual position or speed signal fed back by the potentiometer 40, calculates the deviation value through a PID control algorithm, and adjusts the duty cycle of the PWM (pulse width modulation) signal output to the DC motor 22 accordingly, thereby precisely controlling the speed and direction of the DC motor 22, realizing closed-loop control to improve the stability and control accuracy of the system.

[0044] The noise reduction IC33 and driver IC32 are arranged adjacently and integrated on the PCB board 31. They are used to receive noise signals collected by the contact microphone 50, and after filtering and analog-to-digital conversion, generate an anti-phase sound wave control signal. Specifically, after the contact microphone 50 converts the mechanical vibration noise into an electrical signal, the noise reduction IC33 first filters the signal using its built-in bandpass filter to remove irrelevant frequency components from the environment and retain the main noise frequency range. Then, a high-precision analog-to-digital converter converts the analog noise signal into a digital signal, and a digital signal processing algorithm (such as an adaptive filtering algorithm) generates an anti-phase sound wave with the opposite phase and equal amplitude to the original noise. After digital-to-analog conversion and power amplification, the anti-phase sound wave is output through a speaker. The anti-phase sound wave and the noise generated by the DC motor's operation superimpose and interfere inside the servo motor's housing cavity. Because the two are out of phase, the sound pressure levels in the superposition area cancel each other out, achieving the effect of noise amplitude attenuation or noise elimination.

[0045] In some embodiments, potentiometer 40 is located at the middle position between control component 30 and reduction gear set 21. Potentiometer 40 is electrically connected to control component 30 and coaxially connected to reduction gear set 21. It is used to detect the rotation angle of the servo motor in real time and output a feedback signal.

[0046] Specifically, potentiometer 40 includes a brush and a resistor. The brush is fixedly connected to the output shaft of reduction gear set 21 via an insulating bracket and can rotate synchronously with the output shaft. The resistor has an arc-shaped or ring-shaped layout, is fixed on the base of potentiometer 40, and is electrically connected to PCB board 31. When the servo motor rotates, the output shaft of reduction gear set 21 drives the brush to slide on the surface of the resistor. By changing the contact position between the brush and the resistor, a linear change in resistance value is achieved, thereby converting the mechanical rotation angle of the servo motor into a voltage signal output to drive IC 32, forming the position feedback required for closed-loop control. Potentiometer 40 can accurately track the rotation angle of servo motor 1, providing real-time and accurate position information for the control system.

[0047] In some embodiments, the contact microphone 50 is installed at a slightly upper-middle position on the partition sidewall 121, with its pickup surface facing the DC motor 22. The contact microphone 50 is used to collect noise signals generated by the operation of the DC motor 22 in real time. The noise signals are regular low-frequency signals that exhibit continuous and predictable periodic characteristics when the servo motor 1 is running stably.

[0048] In some embodiments, the speaker 60 is fixedly mounted on the inner surface of the base 13, near the partition sidewall 121, to generate a sound wave signal that is completely opposite in phase to the noise signal, i.e., an inverse sound wave. This inverse sound wave can precisely cancel out the noise signal, thereby significantly reducing the noise level.

[0049] In some embodiments, a damping membrane is adhered to the side of the partition sidewall 121 and the inner surface of the base 13. Specifically, the damping membrane is mainly adhered to and covers the second receiving cavity, that is, the surface of the partition sidewall 121 facing the DC motor 22 and the inner surface of the base 13.

[0050] In some embodiments, the damping diaphragm is required to have a sound absorption coefficient greater than 0.5 and a thickness of approximately 50µm-200µm. It is used to absorb and isolate the mechanical vibration noise generated during the operation of the DC motor 22, thereby reducing the noise of the DC motor 22 during operation and achieving low-noise, high-reliability servo motor performance. The damping diaphragm comprises various membrane materials with a sound absorption coefficient greater than 0.5, such as glass fiber, porous microporous membranes, and piezoelectric fibers.

[0051] In some embodiments, the damping membrane may also be replaced by a sound-insulating membrane.

[0052] In some embodiments, the servo motor 1 further includes a servo disc 80, which may be configured as a straight line. The servo disc 80 is connected to the output shaft of the reduction gear set 21 through a keyway structure, which is used to transmit the rotational motion of the output shaft to external mechanical components.

[0053] In some embodiments, the servo motor 1 further includes four support rods 90, which are respectively vertically arranged at the four corners of the housing assembly 10 and fixedly connected to the upper cover 11 and the base 13, for connecting and supporting the upper cover 11, the middle frame 12 and the base 13.

[0054] The working process of the low-noise servo motor in this embodiment of the invention includes the following steps:

[0055] Noise capture steps: The noise signal generated by the operation of the DC motor 22 is collected in real time by the contact microphone 50. The noise signal is a regular low-frequency signal, which exhibits continuous and predictable periodic characteristics when the servo motor 1 is running stably.

[0056] The inverted signal generation process involves the noise reduction IC 33 filtering and performing analog-to-digital conversion on the noise signal, and controlling the speaker 60 to generate a sound wave signal with the opposite phase to the noise signal, i.e., an inverted sound wave. Specifically, after the contact microphone 50 converts the mechanical vibration noise into an electrical signal, the noise reduction IC 33 first filters the signal using its built-in bandpass filter to remove irrelevant frequency components from the environment and retain the main noise frequency range. Subsequently, a high-precision analog-to-digital converter converts the analog noise signal into a digital signal, and then a digital signal processing algorithm (such as an adaptive filtering algorithm) generates an inverted sound wave with the opposite phase and equal amplitude to the original noise.

[0057] The acoustic interference process involves the antiphase acoustic wave and the noise generated by the DC motor 22 interacting superimposed within the housing of the servo motor 1. Because the two waves are out of phase, the sound pressure levels within the superposition area cancel each other out, resulting in noise amplitude attenuation or noise elimination. Specifically, after digital-to-analog conversion and power amplification, the antiphase acoustic wave is output through a speaker. The antiphase acoustic wave and the noise generated by the DC motor interact superimposed within the housing of the servo motor. Because the two waves are out of phase, the sound pressure levels within the superposition area cancel each other out, achieving noise amplitude attenuation or noise elimination.

[0058] Adaptive adjustment steps: Continuously monitor the operating status of servo motor 1. When changes in operating conditions such as changes in DC motor speed or temperature increase are detected, causing changes in noise characteristic parameters, re-acquire noise signals, continuously detect and analyze them to generate inverse signals, and dynamically adjust the speaker output to maintain the noise reduction effect.

[0059] This invention utilizes a contact microphone to collect noise signals from a DC motor in real time. After processing by a noise reduction IC, it generates anti-phase sound waves with opposite phases. By employing the principle of acoustic wave interference, the noise source is directly canceled out, thereby achieving active noise reduction during servo operation. This reduces motor noise and achieves low-noise, high-reliability servo performance. Furthermore, this invention integrates the noise reduction IC and driver IC onto the servo's PCB board, and places the contact microphone and speaker inside the servo, saving space and reducing the servo's size and weight, ensuring a compact servo structure.

[0060] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A low-noise servo motor, characterized in that, include: The housing assembly includes a top cover, a middle frame, and a base that fit together to form a sealed receiving cavity; A drive assembly, located inside the receiving cavity, includes a reduction gear set and a DC motor, wherein the output shaft of the DC motor is meshed with the reduction gear set. A control component, which is located inside the receiving cavity, includes a PCB board and a driver IC and a noise reduction IC integrated on the PCB board; A potentiometer is located inside the receiving cavity, at the midpoint between the control component and the reduction gear set. The potentiometer is electrically connected to the control component and coaxially connected to the reduction gear set. It is used to detect the rotation angle of the servo motor in real time and output a feedback signal. A contact microphone, located inside the receiving cavity, is used to collect noise generated by the operation of the DC motor; A loudspeaker, which is fixedly mounted on the base, is used to output anti-phase sound waves; The driver IC is used to receive external control commands and control the operation of the DC motor according to the feedback signal output by the potentiometer, forming a closed-loop control system. The noise reduction IC is used to receive the noise signal collected by the contact microphone, and generate an anti-phase sound wave control signal after filtering and analog-to-digital conversion.

2. The low-noise servo motor as described in claim 1, characterized in that, The top cover has a three-layer composite structure. The first layer is teardrop-shaped with an output shaft through hole in the middle. The through hole is coaxial with the output shaft of the reduction gear set and is used for the output shaft to pass through and connect to the outside. The second and third layers are stepped stacked. The third layer has mounting holes symmetrically arranged on both sides for the fixed installation of the servo motor.

3. The low-noise servo motor as described in claim 1, characterized in that, The middle frame has a rectangular frame structure and is connected to the upper cover and the base respectively. The middle frame is provided with a partition sidewall, and the axial length of the partition sidewall is equal to the sum of the height of the middle frame and the height of the base.

4. The low-noise servo motor as described in claim 3, characterized in that, The partition sidewall divides the middle frame into a first independent chamber and a second independent chamber that are not interconnected. The first independent chamber is used to house the control components and potentiometer, and the second independent chamber is used to house the DC motor. The contact microphone is located on the partition sidewall.

5. The low-noise servo motor as described in claim 4, characterized in that, The bottom of the partition sidewall is provided with an opening for the drive line of the DC motor to be connected.

6. The low-noise servo motor as described in claim 1, characterized in that, The reduction gear set includes a primary gear, a driven gear, and a final gear. The primary gear meshes with the output shaft of the DC motor. The driven gear meshes with the primary gear and rotates, and is coaxially connected to the shaft of the potentiometer via a coupling structure. The final gear meshes with the driven gear and rotates, and its output shaft extends to the outside of the housing assembly for connection with external components.

7. The low-noise servo motor as described in claim 1, characterized in that, Damping and vibration-absorbing membranes are attached to the side walls of the partition and the inner surface of the base.

8. The low-noise servo motor as described in claim 7, characterized in that, The damping membrane has a sound absorption coefficient greater than 0.5 and a thickness of 50um-200um, and is used to absorb and isolate the mechanical vibration noise generated during the operation of the DC motor.

9. The low-noise servo motor as described in claim 1, characterized in that, It also includes a steering disk, which is connected to the output shaft of the final stage gear via a keyway structure, for transmitting the rotational motion of the output shaft to external mechanical components.

10. The low-noise servo motor as described in claim 1, characterized in that, It also includes four support rods, which are respectively vertically arranged at the four corners of the outer shell assembly to connect and fix the top cover, the middle frame and the base.

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