Gearbox noise reduction method and gearbox noise reduction system

Abstract

The present application relates to the technical field of gear box, especially to a gear box noise reduction method and a gear box noise reduction system.The noise reduction method comprises the following steps:S1: collecting the environmental noise signal A1 of the gear box before the gear box operates;S2: collecting the current noise signal X0 of the gear box when the gear box operates, and performing inverse filtering processing on X0 to obtain the inverse noise signal X1 after filtering A1;S3: the speaker emits corresponding noise reduction sound towards the gear box according to X1.The gear box noise reduction system uses the above-mentioned gear box noise reduction method, and through the active noise reduction mode, the sound emitted by the speaker and the noise of the gear box are mutually offset, which greatly reduces the energy and propagation distance of the noise of the gear box, and improves the noise reduction effect of the gear box.

Description

Technical Field

[0001] This invention relates to the field of gearbox technology, and in particular to a gearbox noise reduction method and a gearbox noise reduction system. Background Technology

[0002] The operation of wind turbine gearboxes generates significant noise, causing considerable noise pollution to the environment near wind farms and surrounding residents.

[0003] To improve the acoustic environment quality, noise reduction measures are typically implemented for wind turbine gearboxes. These measures include optimizing gear meshing profiles and structural modal analysis to improve transmission stability and efficiency, as well as adding sound insulation structures. All of these measures fall under the category of passive noise reduction. However, due to the complex structure and large size of wind turbine gearboxes, passive noise reduction methods are often ineffective and fail to meet noise reduction requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a noise reduction method and system for gearboxes, so as to achieve active noise reduction of gearboxes and improve the noise reduction effect.

[0005] To achieve this objective, the technical solution adopted by the present invention is as follows:

[0006] The noise reduction method for gearboxes includes the following steps:

[0007] S1: Before the gearbox runs, the ambient noise signal A1 of the gearbox is collected;

[0008] S2: When the gearbox is running, the current noise signal X0 of the gearbox is collected, and the X0 is subjected to inverse filtering to obtain the inverse noise signal X1 after filtering out A1;

[0009] S3: The loudspeaker emits a corresponding noise-reducing sound toward the gearbox according to X1.

[0010] As a preferred embodiment, the noise reduction method for the gearbox further includes the following steps:

[0011] S4: Collect the ambient noise signal A2 of the gearbox at the next moment, and calculate the difference A0 between A2 and A1;

[0012] S5: Synchronously acquire the noise signal X2 of the gearbox at the next moment, and superimpose X2 with A0 to obtain the noise signal X3 at the next moment, so as to obtain the corresponding anti-phase noise signal -X3;

[0013] S6: The speaker continues to emit the corresponding noise-reducing sound toward the gearbox according to -X3 at the next moment.

[0014] As a preferred embodiment, in steps S2 and S5, the noise signal is filtered and inverted using an inverting filter to obtain X1 and -X3, respectively.

[0015] As a preferred embodiment, in steps S3 and S6, before the speaker emits the noise-reduced sound, the digital anti-phase noise signal is converted into an analog anti-phase noise signal by a digital-to-analog converter.

[0016] As a preferred embodiment, in steps S3 and S6, the corresponding noise-reducing sounds are emitted from the gearbox circumferentially and from above the gearbox via multiple speakers.

[0017] As a preferred embodiment, in steps S3 and S6, X1 and -X3 are amplified by power amplifiers, and the loudspeaker emits corresponding noise-reducing sounds toward the gearbox based on the amplified X1 and -X3.

[0018] A gearbox noise reduction system reduces noise in the gearbox using the aforementioned gearbox noise reduction method; the gearbox noise reduction system includes:

[0019] An environmental noise sensor is disposed on one side of the gearbox at a first preset interval to collect the environmental noise signal of the gearbox;

[0020] Multiple gearbox noise sensors are arranged around the gearbox at a second preset spacing to collect noise signals from the gearbox.

[0021] A plurality of speakers are arranged around the gearbox at the second preset spacing to emit noise-reducing sounds toward the gearbox.

[0022] As a preferred embodiment, some of the gearbox noise sensors are arranged at equal intervals around the outer periphery of the gearbox, while the other part of the gearbox noise sensors are arranged at intervals above the gearbox.

[0023] As a preferred embodiment, each gearbox noise sensor is provided with a speaker adjacent to one side.

[0024] As a preferred embodiment, the first preset spacing is 2m to 3m, and the second preset spacing is 20cm to 30cm.

[0025] The beneficial effects of this invention are as follows:

[0026] The noise reduction method for gearboxes proposed in this invention first collects the ambient background noise signal A1 of the gearbox before it starts operating. During gearbox operation, the current noise signal X0 of the gearbox is collected and subjected to inverse filtering to obtain an inverse noise signal X1 after filtering out A1. A loudspeaker then emits a corresponding noise-reduced sound towards the gearbox based on X1. This active noise reduction method cancels out the noise from the loudspeaker, significantly reducing the noise energy and propagation distance, and improving the noise reduction effect.

[0027] The gearbox noise reduction system proposed in this invention adopts the above-mentioned gearbox noise reduction method. Through active noise reduction, the sound emitted by the speaker cancels out the noise of the gearbox, which greatly reduces the noise energy and propagation distance of the gearbox and improves the noise reduction effect of the gearbox. Attached Figure Description

[0028] Figure 1 This is a flowchart of the main noise reduction method provided in the embodiments of the present invention;

[0029] Figure 2 This is a detailed flowchart of the noise reduction method provided in the embodiments of the present invention. Detailed Implementation

[0030] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] Wind turbine gearboxes generate significant noise during operation, necessitating noise reduction measures. These measures typically involve optimizing gear meshing profiles and employing structural modal analysis to improve transmission stability and efficiency, while also incorporating sound insulation. All of these measures fall under the category of passive noise reduction. However, due to the complex structure and large size of wind turbine gearboxes, passive noise reduction methods are often ineffective and fail to meet noise reduction requirements.

[0036] To address the aforementioned problems, this embodiment proposes a gearbox noise reduction system. The system includes an environmental noise sensor, multiple gearbox noise sensors, and multiple speakers. The environmental noise sensors are positioned at a first preset interval on one side of the gearbox to collect the ambient noise signal of the gearbox. The multiple gearbox noise sensors are arranged around the gearbox at a second preset interval to collect the gearbox noise signal. The multiple speakers are arranged around the gearbox at a second preset interval to emit noise-reducing sound towards the gearbox. Through active noise cancellation, the sound emitted by the speakers cancels out the gearbox noise, significantly reducing the noise energy and propagation distance, thus improving the gearbox noise reduction effect.

[0037] In this embodiment, an omnidirectional electret microphone is used as the environmental noise sensor. This type of microphone is readily available and inexpensive. Furthermore, the omnidirectional electret microphone can pick up noise from all directions within the sound field, thus improving the accuracy and precision of the environmental noise signal acquisition. Specifically, the first preset distance is 2m to 3m, meaning the environmental noise sensor is placed approximately 2m to 3m away from the gearbox to ensure the accuracy and precision of the environmental noise signal acquisition. When other types of acquisition elements are used as the environmental noise sensor, the second preset distance can be adaptively adjusted according to the performance of the corresponding acquisition element.

[0038] It should be noted that because the bottom of the gearbox is fixed or installed in a designated location, the noise generated by the gearbox during operation is difficult to propagate from its bottom to the surrounding environment. Therefore, the noise of the gearbox mainly propagates to the surrounding environment from the circumference and top of the gearbox.

[0039] Furthermore, some gearbox noise sensors are arranged at equal intervals around the outer periphery of the gearbox, while others are spaced apart above the gearbox. By placing multiple gearbox noise sensors on the outer periphery and above the gearbox, gearbox noise can be collected from different directions, thus improving the accuracy and precision of gearbox noise acquisition.

[0040] This embodiment has twelve gearbox noise sensors, ten of which are evenly spaced around the circumference of the gearbox, and two are spaced apart and mounted directly above the gearbox. Of course, in other embodiments, the number and installation positions of the gearbox noise sensors can be flexibly adjusted according to the data collection requirements, and are not specifically limited here.

[0041] Specifically, a unidirectional supercardioid electret microphone is used as the gearbox noise sensor. This type of microphone is readily available and inexpensive. It also enables unidirectional noise acquisition, reducing the impact of noise from other directions and further improving acquisition accuracy. Since the theoretical pickup radius of a unidirectional supercardioid electret microphone is no more than 30cm, the aforementioned second preset distance is 20cm to 30cm to ensure reliable acquisition by the gearbox noise sensor. When other types of acquisition elements are used for the gearbox noise sensor, the size of the second preset distance can be adaptively adjusted according to the performance of the corresponding acquisition element.

[0042] Furthermore, a loudspeaker is installed adjacent to one side of each gearbox noise sensor, which enables a compact installation of the loudspeaker and the gearbox noise sensor, while also facilitating the acquisition of sound signals emitted by the loudspeaker by the gearbox noise sensor.

[0043] The gearbox noise reduction system in this embodiment also includes a controller, which mainly includes an inverse filter, an acoustic feedback channel, a power amplifier, and a main control unit. The main control unit has core components such as a filter, an ADC (analog-to-digital converter), an MCU (microcontroller unit), and a DAC (digital-to-analog converter). Since the controller is existing technology, its various functional modules, such as the inverse filter, acoustic feedback channel, power amplifier, and main control unit, will not be described in detail.

[0044] For ease of understanding, such as Figure 1 As shown, this embodiment also proposes a noise reduction method, which specifically includes the following steps:

[0045] S1: Before the gearbox runs, collect the ambient noise signal A1 of the gearbox.

[0046] S2: When the gearbox is running, collect the current noise signal X0 of the gearbox, and perform inverse filtering on X0 to obtain the inverse noise signal X1 after filtering out A1.

[0047] S3: The speaker emits a corresponding noise-reducing sound according to X1's orientation toward the gearbox.

[0048] First, before the gearbox operates, the ambient noise level signal A1 of the gearbox is collected. During gearbox operation, the current noise signal X0 of the gearbox is collected. X0 is then subjected to an inverse filter to obtain an inverse noise signal X1 after removing A1. The speaker emits a corresponding noise-reduced sound towards the gearbox based on X1. This active noise cancellation method effectively cancels out the noise from the speaker and the gearbox, significantly reducing the noise energy and propagation distance, thus improving the noise reduction effect.

[0049] It should be noted that the noise reduction method and gearbox noise reduction system of this embodiment are not only applicable to wind power gearboxes, but also to other gearboxes or other mechanical equipment in similar noise reduction scenarios, which will not be listed here.

[0050] Specifically, in step S1, before the gearbox runs, the environmental noise sensor first collects the environmental noise signal A1 of the gearbox and transmits the environmental noise signal A1 to the main control unit of the controller to store A1 in the main control unit.

[0051] In step S2, when the gearbox generates noise during operation, multiple gearbox noise sensors transmit the current noise signal X0 collected by the gearbox to the main control unit. The noise signal X0 is filtered and inverted by an inverting filter in the controller to obtain X1. The aforementioned inverting filter can filter out the A1 signal in X0 and then invert it to obtain the corresponding inverted noise signal X1, i.e., the noise-reduced signal.

[0052] In step S3, before the speaker emits noise-reduced sound, the digital anti-phase noise signal is converted into an analog anti-phase noise signal by a digital-to-analog converter, so that the speaker can emit noise-reduced sound according to the waveform of the analog anti-phase noise signal.

[0053] Furthermore, the inverted noise signal X1 is amplified by a power amplifier, and the speakers emit corresponding noise-reducing sounds towards the gearbox based on the amplified X1. This ensures that the noise-reducing sounds have the same amplitude and opposite phase to the gearbox noise, thereby improving the noise reduction effect. Specifically, multiple speakers emit corresponding noise-reducing sounds towards the gearbox from both the circumference and top, respectively, to perform active noise reduction on the gearbox in multiple directions, further enhancing the noise reduction effect.

[0054] When the gearbox starts running, noise reduction sounds are emitted from multiple speakers to cancel out noise from various directions within the gearbox. It should be noted that due to signal acquisition errors, speaker intensity and direction errors, a small amount of noise may still be present in the gearbox even after the speakers emit the noise reduction sounds.

[0055] Furthermore, such as Figure 2 As shown, the noise reduction method for gearboxes also includes the following steps:

[0056] S4: Collect the ambient noise signal A2 of the gearbox at the next moment, and calculate the difference A0 between A2 and A1.

[0057] S5: Synchronously acquire the noise signal X2 of the gearbox at the next moment. X2 is superimposed with A0 to obtain the noise signal X3 at the next moment, so as to obtain the corresponding anti-phase noise signal -X3.

[0058] S6: The speaker will continue to emit the corresponding noise-canceling sound toward the gearbox according to -X3 at the next moment.

[0059] Specifically, in step S4, after the gearbox runs and the speaker emits noise reduction sound, the environmental noise sensor collects the environmental noise signal A2 of the gearbox at the next moment again, and transmits the environmental noise signal A2 of the next moment to the main control unit to store A2 in the main control unit, and calculates the difference A0 between A2 and A1. A0 is the superposition signal of the noise signal of the gearbox and the noise reduction signal of the speaker.

[0060] In step S5, the gearbox noise sensor synchronously acquires the gearbox noise signal X2 at the next moment. X2 at this time is the noise signal after noise reduction in step S3. X2 is superimposed with A0 to obtain the actual gearbox noise signal X3 at the next moment. Then, the noise signal is filtered and inverted using an inverting filter to obtain the inverted noise signal -X3. Finally, it is filtered by the filter in the main control unit to output an accurate inverted noise signal.

[0061] Similarly, in step S6, before the speaker emits a noise-reduced sound, the digital anti-phase noise signal is converted into an analog anti-phase noise signal by a digital-to-analog converter, so that the speaker can emit a noise-reduced sound according to the waveform of the analog anti-phase noise signal.

[0062] Furthermore, the inverted noise signal -X3 is amplified by a power amplifier. The speakers then emit corresponding noise-reducing sounds towards the gearbox based on the amplified -X3, ensuring that the noise-reducing sounds have the same amplitude and opposite phase to the gearbox noise, thereby improving the noise reduction effect. Specifically, multiple speakers emit corresponding noise-reducing sounds towards the gearbox from both the circumference and top, achieving active noise reduction in multiple directions and further enhancing the noise reduction effect.

[0063] In step S6, the power amplifier outputs the noise reduction signal from the loudspeaker to the acoustic feedback channel, and serves as negative feedback for the gearbox noise sensor to synchronously collect the noise signal of the gearbox at the next moment. This eliminates the error between the ambient background noise signal and the waveform signal sent by the power amplifier, thereby realizing closed-loop control of the gearbox noise reduction system and improving the noise reduction effect.

[0064] During the operation of the gearbox, by repeating steps S4 to S6, the gearbox noise reduction system can perform efficient active noise reduction on the running gearbox, thereby improving the noise reduction effect.

[0065] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A noise reduction method for a gearbox, characterized in that, Includes the following steps: S1: Before the gearbox runs, the ambient noise signal A1 of the gearbox is collected; S2: When the gearbox is running, the current noise signal X0 of the gearbox is collected, and the X0 is subjected to inverse filtering to obtain the inverse noise signal X1 after filtering out A1; S3: The loudspeaker emits a corresponding noise-reducing sound toward the gearbox according to X1; S4: Collect the ambient noise signal A2 of the gearbox at the next moment, and calculate the difference A0 between A2 and A1; S5: Synchronously acquire the noise signal X2 of the gearbox at the next moment, and superimpose X2 with A0 to obtain the noise signal X3 at the next moment, so as to obtain the corresponding anti-phase noise signal -X3; S6: The speaker continues to emit the corresponding noise-reducing sound toward the gearbox according to -X3 at the next moment.

2. The noise reduction method for a gearbox according to claim 1, characterized in that, In steps S2 and S5, the noise signal is filtered and inverted using an inverting filter to obtain X1 and -X3, respectively.

3. The noise reduction method for a gearbox according to claim 1, characterized in that, In steps S3 and S6, before the speaker emits the noise-reduced sound, the digital anti-phase noise signal is converted into an analog anti-phase noise signal by a digital-to-analog converter.

4. The noise reduction method for a gearbox according to claim 3, characterized in that, In steps S3 and S6, the corresponding noise-reducing sounds are emitted from the gearbox circumferentially and from above the gearbox via multiple speakers.

5. The noise reduction method for a gearbox according to claim 1, characterized in that, In steps S3 and S6, X1 and -X3 are amplified by power amplifiers, and the loudspeaker emits corresponding noise-reducing sounds toward the gearbox based on the amplified X1 and -X3.

6. A gearbox noise reduction system, characterized in that, The gearbox is noise-reduced using the gearbox noise reduction method described in any one of claims 1 to 5; the gearbox noise reduction system comprises: An environmental noise sensor is disposed on one side of the gearbox at a first preset interval to collect the environmental noise signal of the gearbox; Multiple gearbox noise sensors are arranged around the gearbox at a second preset spacing to collect noise signals from the gearbox. A plurality of speakers are arranged around the gearbox at the second preset spacing to emit noise-reducing sounds toward the gearbox.

7. The gearbox noise reduction system according to claim 6, characterized in that, Some of the gearbox noise sensors are arranged at equal intervals around the outer periphery of the gearbox, while other gearbox noise sensors are arranged at intervals above the gearbox.

8. The gearbox noise reduction system according to claim 7, characterized in that, Each gearbox noise sensor has a speaker installed adjacent to one side.

9. The gearbox noise reduction system according to claim 6, characterized in that, The first preset spacing is 2m to 3m, and the second preset spacing is 20cm to 30cm.

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