451 results about "Acoustic quieting" patented technology

The utility model relates to the field of air conditioner air outlet devices, in particular to a central air conditioner air outlet noise reduction device which comprises an air receiving barrel, a bucket-shaped air expanding cover, an air outlet cover, a noise reduction frame, an air direction guiding frame and a protection frame. A hopper-shaped air expanding cover is arranged at the lower end of the air receiving barrel, an air outlet cover is arranged at the lower end of the hopper-shaped air expanding cover, an embedded groove is formed in the end, away from the hopper-shaped air expanding cover, of the air outlet cover, and a noise reduction frame, an air direction guiding frame and a protection frame are sequentially arranged in the embedded groove. According to the air conditioner air outlet device, noise generated by airflow resonance is effectively reduced through the air expansion flow guide design of the hopper-shaped air expansion cover and the sound absorption cotton plate filling of the sound attenuation and noise reduction frame, airflow can be evenly and softly blown to a room through the design of the air direction guide frame, and the problems that airflow in a traditional air conditioner air outlet device is too strong and uneven in distribution are solved.

This utility model relates to a noise reduction structure for a DC motor, wherein the noise reduction structure (1) is disposed within a cavity for accommodating a commutator (2) and close to the sound source. The noise reduction structure (1) can be a honeycomb structure, a square structure, a circular structure, or a regular polygonal structure, and can be disposed on the bottom surface of the cavity, or simultaneously on the sidewalls and bottom surface of the cavity. The noise reduction structures (1) can be evenly distributed on the bottom surface and sidewalls of the cavity, or staggered. In addition, the noise reduction structure (1) can also be disposed within the cavity of a gearbox (5), including at the bottom of the gearbox cavity (6), or simultaneously on the bottom and cavity walls of the gearbox cavity (6). Using this noise reduction structure for a DC motor, the sound waves generated by the sound source are effectively reflected and canceled out by the noise reduction structure, thus reducing the noise of the DC motor and possessing certain practical value.

The utility model relates to the technical field of noise reduction plates, and discloses a shock absorption and noise reduction plate which comprises a shock absorption and noise reduction plate body, a shock absorption groove is formed in the outer surface of the front side of the shock absorption and noise reduction plate body, and a first damping rubber pad adheres to the inner surface of the rear side of the shock absorption groove. First rubber blocks are arranged at the positions, close to the four corners, of the outer surface of the front side of the first damping rubber pad, first clamping grooves are formed in the outer surfaces of the front sides of the four first rubber blocks, damping springs are connected to the interiors of the four first clamping grooves in a clamped mode, and a partition plate is fixedly connected to the position, close to the center, of the inner surface wall of each damping groove; the utility model solves the problem that the working efficiency of the equipment is reduced because the ideal noise reduction and sound attenuation effect cannot be achieved due to overhigh sound vibration frequency when the traditional sound attenuation plate is generally applied to places with higher noise, such as a music hall and the like.

This utility model discloses a negative pressure compressor silencer made of composite sound-absorbing material, including a negative pressure fan body and a silencer pipe fixedly installed on the air inlet end of the negative pressure fan body. An air inlet channel is fixedly installed on the inner wall of the silencer pipe, and a primary noise reduction mechanism is provided on the inner wall of the air inlet channel near the pipe opening. The primary noise reduction mechanism includes an air inlet cylinder fixedly installed on the inner wall of the air inlet channel, and multiple air inlets are opened on the outer wall of the air inlet cylinder. This utility model, through the inner ring silencer cylinder, outer ring silencer cylinder, and silencer ring cylinder of the primary noise reduction mechanism forming a multi-stage sound absorption structure, utilizes the cooperation between the silencer holes and the annular cavity to allow sound waves to reflect and diffract between different cavities, effectively absorbing mid-to-high frequency noise. The coaxial and annular array distribution design of the air inlets guides the airflow to enter evenly, reducing the generation of eddy noise. The composite structure of the perforated metal cylinder and the sound insulation felt further blocks the transmission of noise, improving the broadband noise reduction effect.

The utility model discloses a noise reduction type drainage pipeline, which belongs to the technical field of drainage pipelines, and comprises a first pipe body and a second pipe body, the right side of the first pipe body is provided with a connector, the left side of the second pipe body is provided with a connecting seat, the top and the bottom of the connecting seat are both fixedly provided with rectangular grooves, and the rectangular grooves are communicated with the first pipe body and the second pipe body. Limiting rods are fixedly connected to the left side and the right side of an inner cavity of the rectangular groove, the outer sides of the limiting rods are movably sleeved with limiting blocks, lantern rings are fixedly connected to the top of the limiting block at the top and the bottom of the limiting block at the bottom, and silencing layers are arranged in inner cavities of the first pipe body and the second pipe body. According to the utility model, two pipelines can be conveniently and quickly spliced, the operation by virtue of an auxiliary tool is avoided, the installation efficiency of workers is improved, a certain silencing effect is achieved, the sound generated when water flows in the pipelines can be reduced, and the comfort of living and working is improved.

The application discloses a noise reduction air inlet air duct of a dust collector body, and relates to the technical field of dust collector accessories, which comprises a dust collector body and a noise reduction assembly. A double-layer nested first cylinder and a second cylinder are arranged in the ventilation pipeline of the noise reduction assembly. The first cylinder and the second cylinder are respectively provided with first through holes and second through holes which are staggered and communicated to form sound holes. When the device is working, the air duct airflow pressure cooperates with the magnetic control air path and the spring reset structure to adaptively adjust the effective communication cross-sectional area of the sound holes according to the operating power of the dust collector. In the high-power working condition, the aperture is automatically enlarged to improve the full-band noise reduction effect, and in the low-power working condition, the aperture is reduced to avoid negative pressure and air volume loss. Meanwhile, the composite noise reduction material, the split pipeline and the detachable sealing locking connection structure are matched. The problems that the traditional fixed sound holes cannot adapt to multiple working conditions and the noise reduction and dust collection performance are difficult to be considered are solved.

The utility model belongs to air conditioner compressor technical field especially relates to a kind of noise reduction structure of air conditioner compressor sound attenuation package, including frame, air inlet and air outlet are set up on frame, frame has sound attenuation chamber inside, noise enters from air inlet, to sound attenuation chamber inside, then noise passes through air outlet and enters into gas storage chamber, in turn through upper support plate, middle support plate and lower support plate, finally from exhaust port inside the noise is discharged, when noise spreads to sound attenuation chamber inside, will first collide with assembly component, noise will occur reflection, refraction and scattering and other phenomena in the process of collision, so that noise is in the bounce space Bounce back.And in the bounce process, the energy of noise will be gradually consumed and dispersed, because installation frame is installed at air outlet, to lengthen the path of noise, further reduce noise;Compared with prior art, the utility model thereby improves sound attenuation effect.

The present invention relates to a compressor including a compression mechanism adapted to compress a fluid and a sound deadening partition for partitioning an internal space of the compressor into a high-pressure side and a low-pressure side, the sound deadening partition including a mounting hole and an insert mounted in the mounting hole, the fluid compressed by the compression mechanism being discharged to the high-pressure side via a passage of the insert and then to the outside of the compressor, the insert having an interference fit with the mounting hole and having an interference fit portion, and a protruding section protruding toward the high-pressure side direction with respect to the remaining portion of the sound deadening partition being provided at a portion of the sound deadening partition adjacent to the interference fit portion. The present invention provides a compressor improved in sound deadening configuration and safety reliability.

The utility model relates to the technical field of sound attenuation equipment, specifically relates to a compressor sound attenuation device, including compressor, the bottom plate of installing compressor, the cavity containing compressor and the top -tight mechanism of connecting cavity and compressor, the cavity is composed of the upper end cover of open and close and the closed wall body, its lower end opening is fixedly connected with the bottom plate, still has the through -hole of connecting compressor copper pipe on the upper end cover, and the top -tight mechanism is connected in the lower part and the upper part of compressor in pairs, and two pairs of top -tight mechanism are cross -distributing in the four -around of compressor on the projection plane, and the mounting seat of connecting top -tight mechanism is still provided in the closed wall body. The utility model discloses a compressor sound attenuation device, through the cavity of close connection with the shell, the compressor is contained and fixed in the cavity, reduces the noise of compressor, and the top -tight mechanism is still provided between the cavity and compressor to reduce or eliminate the vibration noise produced when the compressor works.

The invention relates to the technical field of hub polishing, in particular to a rear axle hub special polishing device capable of preventing environmental pollution, which comprises a base, a second sound insulation layer is arranged on the base, a first sound insulation layer forming a double-layer structure with the second sound insulation layer is arranged in the second sound insulation layer, and a top cover is overturned on the second sound insulation layer. And a silencing mechanism is arranged on the second sound insulation layer, and the silencing mechanism comprises a rotating rod rotating at the center of the bottom of the second sound insulation layer. In the working process, an interlayer between the second sound insulation layer and the first sound insulation layer gradually tends to be in a vacuum environment, energy can be rapidly attenuated when sound waves are transmitted in an air rarefied medium, noise generated by polishing is rapidly attenuated, and the situation that workers are injured by the noise due to long-time work is avoided; and the pollution of noise to the environment is reduced.

The invention relates to the field of masks, and discloses a mask and a control method thereof, the mask comprises a mask body, a secondary sound source device and a voice signal acquisition part; the mask body comprises a mouth and nose wrapping structure and a mask shell, and the mouth and nose wrapping structure is connected with the mask shell; the voice signal acquisition part comprises a main microphone, and the main microphone is arranged on the inner side of the mouth and nose wrapping structure; the secondary sound source device is arranged on the outer side of the mask shell and works based on a control instruction. According to the mask, user sound or environmental noise is collected through the voice collecting part, the secondary sound source device sends out corresponding sound according to user requirements or conducts phase reversal processing on sound waves, and sound opposite to the user is sent out to achieve sound wave counteracting near the air outlet so as to achieve the purpose of active noise reduction; or scrambling signals such as white noise, environment sound and scene sound are generated, and user voice is hidden to the maximum extent; or the sound of the user is amplified, so that the sound is clearer and more stable.

The utility model relates to the field of noise reduction equipment, specifically disclose a sound attenuation room of reducing noise, including a plurality of by the sound attenuation room main part of inner panel and outer panel, the sound attenuation room main part is connected each other through the connecting structure to form a casing with the cavity, the sound attenuation room main part adopts integrated structure, constitutes by the wallboard of Q235A material, ceiling and access door, and ceiling can be individually detached, the sound attenuation room is filled with fire -resistant sound attenuation cotton, and the fire -retardant sound attenuation cotton is cut even neat and tightly wrapped in the wallboard, the utility model provides a sound attenuation room of reducing noise, through the connecting design of optimization air duct and wallboard, reasonable layout equipment, adopt sound insulation material and set up sound attenuation device etc.

An intake pipe integrating two silencing structures includes a pipe body formed by the joining of an upper shell and a lower shell. A first opening and a second opening are formed on the bottom wall of the lower shell. A first cylinder and a second cylinder are integrally formed on the outer bottom surface of the lower shell, corresponding to the positions of the first and second openings, respectively. The opening of the first cylinder overlaps with the first opening and forms a wavelength tube within the first cylinder. The opening of the second cylinder overlaps with the second opening, and a cover plate is provided over the second opening. A third opening is formed in the middle of the cover plate. An annular baffle is integrally formed on the bottom surface of the cover plate, corresponding to the position of the third opening. The cover plate, the annular baffle, the second cylinder, and the third opening form a holmhertz silencer. By integrating a wavelength tube and a holmhertz silencer on the intake pipe, a wider frequency band can be covered, forming a complementary effect, thereby reducing mid-to-high frequency noise and low-frequency noise within the intake pipe respectively. This invention has a simple structure and is easy to manufacture and assemble.

The utility model discloses a noise reduction air receiving port, which comprises a square frame, an outer plate, a shell, an air inlet, an air inlet pipeline, an air outlet joint, an inner plate and an air outlet, the outer plate is arranged above the square frame, the shell is arranged on the outer plate, the air inlet is arranged on the shell, one side of the shell is connected with the air inlet pipeline, and the other side of the shell is connected with the air outlet joint. One end of the air inlet pipeline is communicated with the air inlet in the shell, and the other end of the air inlet pipeline is communicated with an air outlet connector. An inner plate is installed below the square frame, an air outlet is formed in the inner plate and communicated with the air outlet end of the air outlet connector, the shell is of a square structure with an opening in the top, an air inlet is formed in the side wall of the shell, the air inlet pipeline is a porous noise reduction air channel, the air outlet connector is composed of two air channel connectors, and the air inlet connector is connected with the air inlet pipeline. According to the utility model, wind noise and external sound can be reduced, so that the sound insulation effect of the cabin body is improved, and wind circulation is kept.

This invention relates to a spiral noise-canceling earphone, comprising: an earphone head including a front cavity and a rear cavity opposite to the front cavity, wherein a sound-generating unit is disposed within the front and rear cavities; one end of the rear cavity that connects to the front cavity is designated as the front end, and the other end as the rear end; the inner wall of the rear cavity extends from the front end to the rear end, and the distance to the center of the rear cavity decreases as it approaches the rear end; a noise-canceling structure is provided on the inner wall of the rear cavity, the noise-canceling structure including a first spiral ridge, a second spiral ridge, and a spacer groove; the first spiral ridge and the second spiral ridge extend clockwise or counterclockwise from the front end of the rear cavity along its inner wall to the rear end; through the cooperation of the first spiral ridge, the second spiral ridge, and the spacer groove, combined with the conical cavity and the gradually changing width of the spiral ridge, a complex sound wave propagation path is formed; when noise passes through these spiral channels, the sound waves are subjected to multiple reflections and interferences, resulting in gradual energy attenuation, thereby achieving the effect of eliminating noise and improving sound quality.

The utility model relates to the field of sound attenuation and noise reduction devices, in particular to a diffusion sound attenuation and noise reduction device for a gas buried valve, which comprises a first hot galvanizing metal net, a mounting frame, a connecting spring, a self-pressure-relief top cover, a gland and a gas diffusion valve, the upper end of the first hot-dip galvanized metal net is sleeved with a mounting frame, a self-pressure-relief top cover used for safely relieving pressure when the flow rate of exhausted gas exceeds 30 m / s and the pressure exceeds 0.3 Mpa is mounted in the center of the upper surface of the mounting frame, a gland used for relieving pressure is mounted in the center of the upper surface of the self-pressure-relief top cover, and three sets of air diffusion valves are sequentially and transversely mounted at the upper end of the gland. According to the diffusion, noise reduction and noise reduction device for the gas buried valve, noise generated in the exhaust process of gas is reduced again through the secondary noise reduction silencer, when the gas passes through the silencer, sound waves can be reflected, absorbed, scattered and the like through a noise reduction material and an internal structure, the noise reduction effect is good, and the noise reduction effect is good. Therefore, the noise propagation is weakened again.

The utility model relates to a sound insulation and shock absorption structure of a guest room wall body, which comprises a wall surface hanging piece, a hanging rod, shock absorption and sound insulation pads, a plate hanging piece and a wall surface plate, the wall surface hanging piece is arranged on the wall body through a fastening piece, the hanging rod is hung on the wall surface hanging piece, the shock absorption and sound insulation pads are arranged according to a wavy line shape and sleeved on the hanging rod, the plate hanging piece is hung on the hanging rod, and the wall surface plate is arranged on the wall surface hanging piece. The wall panel is installed on the panel hanging piece through the fastening piece, and the shock absorption and sound insulation pad is clamped between the wall panel and the wall body. The damping and sound insulation pad has the advantages that the damping and sound insulation pad is hung on the wall through cooperation of the hanging rod and the wall surface hanging piece, the damping and sound insulation pad is arranged in a wavy line shape, a silencing cavity is formed, sound waves can be absorbed easily, and the elastic deformation space is increased to improve the damping effect; the wall surface is hung on the wall body through cooperation of the plate hanging piece, the hanging rod and the wall surface hanging piece, the wall surface plate is prevented from being directly and fixedly connected with the wall body or the damping and sound insulation pad, a damping activity space is provided for the wall surface plate, and sound and vibration waves are prevented from being transmitted between adjacent hotel guest rooms on the same layer through the wall body.

The invention discloses a sound absorption structure, an air outlet head and air treatment equipment, and relates to the technical field of life electric appliances, the sound absorption structure is applied to the air treatment equipment, an air duct is arranged in the air treatment equipment, and the sound absorption structure comprises a plurality of sound absorption channels and a plurality of sound absorption holes correspondingly communicating with the sound absorption channels; the sound absorption structure is communicated with the air channel through the sound absorption holes, the sound absorption channels are not communicated with one another, and the total lengths of at least two sound absorption channels are different. According to the technical scheme, the sound absorption structure can have the noise reduction characteristic that the sound absorption frequency and the sound absorption coefficient can be adjusted at will, and then noise of equipment applying the sound absorption structure is reduced.

The utility model discloses a mute type car window motor, and particularly relates to the technical field of car window motors, the mute type car window motor comprises a mounting frame arranged outside a motor main body, and a plurality of groups of sound absorption pieces used for silencing are arranged outside the mounting frame; each group of sound-absorbing parts comprises a sound-absorbing plate arranged in the mounting frame, and a plurality of groups of buffer parts for buffering impact are arranged outside the sound-absorbing plate; and each group of buffer parts comprises a fixing column mounted outside the sound absorption plate, the end, away from the sound absorption plate, of the fixing column penetrates through the mounting frame and extends to the outside of the mounting frame, and a fixing plate is mounted at the end, away from the sound absorption plate, of the fixing column. The connecting plate is pressed to drive the positioning columns to move inwards, the positioning columns push the positioning plate to compress the spring, and therefore the folded positioning plate, the spring and the fixing plate can be lower than the positioning shell, and the sound absorbing piece and the buffering piece can be conveniently moved out through the sliding way to be replaced; therefore, the convenience of dismounting and replacing the sound absorbing member and the buffer member is improved.

This utility model relates to the field of sound absorption technology, particularly to a composite modified sound-absorbing panel, comprising: a panel body, protrusions, locking holes, and latches. Multiple protrusions are slidably arranged on the panel body, and multiple locking holes are provided on any two adjacent sides of the panel body. Multiple latches are provided on the other two adjacent sides of the panel body, and the locking holes and latches between different panels cooperate to lock and fix them in place. By sliding the protrusions up and down, sound waves of different magnitudes are absorbed. This invention solves the problem that existing sound-absorbing structures cannot maximize the sound absorption and vibration reduction effect, and cannot effectively reduce noise and vibration of different magnitudes. It achieves that the sound-absorbing panel can maximize sound absorption and vibration reduction, and can effectively reduce noise and vibration of different magnitudes.

This invention discloses an H-configuration multimodal noise-absorbing vibration damper and its design method, belonging to the field of vibration control technology. The vibration damper includes a composite-clad elastic plate, an elastic plate, a multimodal coupling structure, and movable counterweights. The elastic plate assembly includes a composite-clad elastic plate, which is a layered structure formed by combining fiberglass epoxy board and stainless steel, prepared by a molding process. The material ratio of fiberglass epoxy board to stainless steel is determined according to the formula for the stiffness of a simply supported beam spring. Both sets of movable counterweights can slide and adjust their positions along the length of the composite-clad elastic plate or the elastic plate, adapting to the vibration suppression requirements of different frequency bands by changing the mass distribution of the noise-absorbing vibration damper. The multimodal coupling structure is integrated into the elastic plate assembly, and frequency control of multiple modes is achieved through stiffness matching between the elastic plate assembly and the multimodal coupling structure. This invention can cover a wide frequency band, has high vibration reduction efficiency, and a reliable structure, providing technical support for the field of multi-frequency vibration suppression.

The outer ring fire cover comprises a fire cover body, the fire cover body is provided with a plurality of fire holes distributed in the circumferential direction of the fire cover body, and the outer ring fire cover further comprises a noise reduction structure; the silencing structures are arranged on the sides, facing the radial inner side of the fire cover body, of the fire holes, the silencing structures and the fire holes are arranged in the radial direction of the fire cover body at intervals, and gas chambers communicating with the fire holes are formed. The noise reduction structure comprises a gas channel and a plurality of noise reduction parts arranged in the circumferential direction of the fire cover body at intervals, and the gas channel is formed by the interval between every two adjacent noise reduction parts. And the structure of the fuel gas channel is set as follows: the flow rate of fuel gas flowing through the fuel gas channel is greater than that of fuel gas flowing through the fuel gas chamber. The silencing structure is arranged in the outer ring fire cover, so that gas flowing to the fire holes is silenced, and the combustion performance of the combustor is not affected.

The application discloses a charging pile soundproof cover and belongs to the technical field of charging piles. The soundproof cover comprises an outer cover. The outer cover is the main structure of the soundproof cover and is detachably fixed on the air inlet and outlet of the charging equipment through a mounting piece. The outer cover defines a cavity for accommodating and guiding the propagation of sound. The cavity has a first opening through which sound propagates into the cavity of the outer cover. The inner wall of the outer cover is covered with a sound-absorbing layer for absorbing sound entering the cavity. The sound propagating into the cavity of the outer cover through the first opening is absorbed by the sound-absorbing layer covering the inner wall of the outer cover, thereby effectively reducing the propagation of sound of the charging equipment. Further, the cavity also has a second opening adjacent to the first opening, through which the heat of the air inlet and outlet of the charging equipment can be discharged. At the same time, by adjusting the fixed position of the outer cover to change the opening direction of the second opening, the propagation direction of residual sound can be changed, thereby minimizing the influence on the user.

The application discloses a vibration-absorbing and sound-absorbing device for a precision detection instrument experiment table, which is used for reducing the noise and vibration of the air path of the experiment table and comprises the following components: an air inlet assembly, a Tesla sound-absorbing assembly, two symmetrical semi-cylindrical sound-absorbing blocks, a plurality of Tesla flow channels arranged on the sound-absorbing blocks, the Tesla flow channels receiving the airflow provided by the air inlet assembly, a cylindrical sound-absorbing column formed by the two symmetrical semi-cylindrical sound-absorbing blocks, a first elastic metal sheet arranged on the joint surface of the two symmetrical semi-cylindrical sound-absorbing blocks, a cavity arranged on the outer circumference of the sound-absorbing column, and a shear thickening fluid STF filled in the cavity, a vibration-absorbing assembly and an air outlet assembly. The application has the beneficial effect that the vibration and noise of the pneumatic pipeline used in the precision detection experiment table are greatly reduced, and a low-noise and stable working environment is provided for the precision detection.

To reduce noise of a flow inside a pipe. An aspect of the present disclosure relates to a sound-reducing pipe including: a pipe body having a first flow inlet and a first flow outlet for a gas, and a peripheral wall including an inner peripheral surface connecting the first flow inlet and the first flow outlet and serving to form a flow passage for the gas to flow from the first flow inlet to the first flow outlet; and a plurality of protrusions protruding from the peripheral wall, a front end of the protrusion being located inside the pipe body as compared to the inner peripheral surface located closer to the first flow inlet side than the front end of the protrusion.

The application discloses a kind of sound attenuation device for boiling dryer, including silencer shell, the bottom and top outer wall are respectively provided with first, second mounting edge and bolt hole, first, second, third sound attenuation component are sequentially assembled in shell from bottom to top.Silencer shell is divided into four sections, first sound attenuation part is formed adjustable annular channel by first bushing, first sound attenuation pipe, first sleeve and first spring, second sound attenuation part is provided with sound attenuation passage and sound attenuation cotton, third sound attenuation part is realized dynamic cross-sectional area adjustment by second bushing, second sound attenuation pipe, second sleeve, expansion plate and second spring.The device can effectively reduce the noise of boiling dryer through the frequency self-adaptive adjustment of multi-stage sound attenuation structure, and the sound attenuation volume is greater than or equal to 25dB (A) under rated operating condition, and is suitable for-20℃-120℃ environment.

The utility model discloses a noise reduction box and a traction machine, which belong to the technical field of traction machines, the noise reduction box comprises a first plate, a second plate and four third plates, the first ends of the four third plates are all installed on the first plate, the second ends of the four third plates are all installed on the second plate, the first plate and the second plate are arranged oppositely, and the first plate and the second plate are arranged oppositely. A cavity is formed among the inner sides of the first plate, the second plate and the four third plates; the first plate or the second plate is provided with a plurality of first ribs and second ribs, the first ribs extend in the width direction of the first plate or the second plate, and the second ribs extend in the length direction of the first plate or the second plate; the first ribs and the second ribs are distributed in a criss-cross mode, and a plurality of silencing areas are formed. The multiple silencing areas are used for conducting isolation and differentiation treatment on sound waves of the noise reduction box, the sound waves of the noise reduction box are prevented from being overlapped, the multiple silencing areas can prevent the sound waves from generating a resonance effect, and therefore 5%-15% of noise of a noise source can be reduced.

The invention relates to the technical field of noise reduction, in particular to a silencing unit, a silencing module, a silencer, a compressor and a silencing control method. The silencing unit comprises a first prism, a second prism, a first sealing plate, a second sealing plate, a first sealing film, a second sealing film and an electromagnetic driving assembly, the first sealing film is attached to the inner surface of the first prism, and the second sealing film is attached to the outer surface of the second prism; a first sealing cavity is defined by the first sealing film, the second sealing film, the first sealing plate and the second sealing plate, and the first sealing cavity is configured to be filled with magnetorheological media. The magnetorheological state of the magnetorheological medium is controlled through the magnetic field, rapid switching of the silencing unit among different acoustic working modes is achieved, the silencing unit can dynamically adapt to different frequency band noise generated by the compressor under different load working conditions, and the problems that a traditional silencer is fixed in silencing frequency band and poor in working condition adaptability are solved.