42results about How to "Reduce sound radiation" patented technology

Vibro-acoustic attenuation or reduced energy transmission. The present invention relates to devices that display frequency zones of strong vibro-acoustic attenuation or reduced energy transmission. This can be used in particular, although not necessarily solely, in applications that require lightweight materials with good mechanical properties and good vibro-acoustic response or in applications that require materials with high sound reflection, absorption or sound isolation in a certain frequency band.

Vibro-acoustic attenuation or reduced energy transmission. The present invention relates to devices that display frequency zones of strong vibro-acoustic attenuation or reduced energy transmission. This can be used in particular, although not necessarily solely, in applications that require lightweight materials with good mechanical properties and good vibro-acoustic response or in applications that require materials with high sound reflection, absorption or sound isolation in a certain frequency band.

A muffler system for a compressor includes an expansion chamber muffler for reducing pressure pulses at the compressor's fundamental pulsation frequency and a side-branch muffler for filtering high-frequency pressure pulses. The expansion muffler is positioned along the compressor discharge stream at a location that maximizes pulsation reduction at the compressor's fundamental pulsation frequency. The side-branch muffler is tuned to the frequency at which the pulsation reduction for the expansion muffler is at a minimum.

The invention aims to provide a composite damping supporting plate structure for ships. The invention comprises a supporting plate, a hollow damping mass block, an acoustic absorbent and a band plate, wherein the hollow damping mass block is installed on the supporting plate, the band plate is fixed on the hollow damping mass block, and the acoustic absorbent is installed on the band plate. By utilizing the rigid damping technology, on the premise of no large deformation of the supporting plate structure, the invention obtains favorable effects of damping and noise reduction, and has the functions of damping and sound absorption. On the premise of minimally increasing the weight of the supporting plate, the invention effectively reduces the vibration and acoustic radiation at the power bay section of the ship, has the advantages of higher cost-benefit ratio and high economical efficiency, is a structural acoustic design between double layer hulls suitable for various ships, and has wide application prospects.

The invention discloses a sound-absorbing large-damping self-resetting track mechanism, which adopts a C-shaped track body. The track body is injected with a two-color injection mold. The inside of the track body is inlaid with rubber materials. Dry friction occurs between the rail bodies. The bullet bears the extrusion force of the gear slot, and the internal spring is compressed accordingly. The extruded spring has the function of storing energy. When the external force is removed, the spring returns to its original state, and the whole mechanism is reset at the same time. The present invention adopts a structure with large damping to help reduce the resonance amplitude of the structure, and avoid mechanism damage caused by the vibration stress inside the structure; it helps the mechanism to quickly recover to a stable state after being subjected to an instantaneous impact; Acoustic radiation from mechanical vibrations. The present invention also realizes the shift form of the internal mechanism of the gear shifter, which is self-resetting. This mechanism is realized by the principle that the spring deforms under the action of the external force and returns to its original shape after the external force is removed.

The invention discloses a vibration and noise comprehensive control system for rail traffic. The system comprises a rail base, a floating plate, a non-linear vibration isolator, a rail, a periodicityvibration absorber and steel rail vibration noise inhibition devices. The floating plate is arranged above the rail base, the non-linear vibration isolator is placed on the floating plate, and the steel rail vibration noise inhibition devices are arranged on the surface of the waist portions of the two sides of the rail. The vibration and noise comprehensive control system for rail traffic is composed of the floating plate, the non-linear vibration isolator, the rail, the periodicity vibration absorber and the steel rail vibration noise inhibition devices, vibration reduction is conducted firstly, then noise reduction is conducted, the non-linear vibration isolator and the periodicity vibration absorber are adopted for vibration reduction and the noise reduction, the aims of controlling environment vibration and lowering plate sound radiation of the floating plate are achieved, control over the noise of a wheeltrack can be achieved, the noise in a train is inhibited, and accordingly the vibration and noise cooperation control effect is achieved.

A bearing bush is for a holder, which is for fastening a component, particularly of a fuel distributor, to an add-on structure. The bearing bush has an inner bush part, which is made of a metallic material, and an outer bush part, which is made of a metallic material, and an elastically deformable damping element. The outer bush part has a continuous recess, in which the inner bush part is situated. The damping element is situated between the inner bush part and the outer bush part. A holder having such a bearing bush is also specified. In addition, a fuel-injection system having a fuel distributor and at least one holder is specified, which is used for fastening the fuel distributor on an internal combustion engine.

The invention discloses a vehicle brake system simulation testing stand. The testing stand includes a testing stand, a column and a fixing stand, wherein one end of a top portion of the testing standis equipped with the fixing stand through a bolt, one side of the fixing stand is equipped with a vehicle bridge portion through a mounting support, one side of the vehicle bridge portion is connectedwith a brake disc through a rotation shaft, one side of the brake disc is welded with a connection shaft, one end of the connection shaft is connected with the rotation shaft through a coupling, a top portion of the vehicle bridge portion is equipped with a casing through a bolt, the casing is internally provided with a doughnut shape-like oil cavity, two sides at a bottom end in the doughnut shape-like oil cavity are provided with a piston through a mounting member, two sides of a top end of the brake disc are provided with friction blocks, and the other end of a top portion of the testing stand is equipped with a supporting plate through a bolt. The testing stand is advantaged in that functions are various, operation is simple, production is convenient, multiple test demands are satisfied, and the testing stand is suitable for wide popularization and application.

The invention relates to the field of rail damping and denoising, in particular to a damping jacket for a railway rail and an assembly method thereof. The damping jacket for the railway rail comprises an expansion layer clung to the rail base and rail web of the railway rail, wherein a coating is formed outside the expansion layer, sealing layers are formed at two ends of the expansion layer and the coating, a closed space is formed by the expansion layer, the coating and the sealing layers, and the closed space is filled with liquid damping material. The assembly method comprises the steps as follows: (1) connecting the expansion layer, the coating and the sealing layer at one side together; (2) injecting the liquid damping material to a cavity; (3) arranging the other sealing layer at the opening position; (4) sleeving the damping jacket from one end of the railway rail; and (5) arranging sleepers at the bottom of the railway rail. According to the invention, the damping jacket filled with the damping material is coated on the rail, and the damping material has the damping and the denoising functions, so that the wheel rail noise generated by the rail vibration is effectively reduced.

The invention discloses a low-shrinkage HIPS composite material for solving abnormal sound, and a preparation method thereof. The material comprises, by weight, 60-80 parts of HIPS resin, 3-10 parts of a rubber composite material, 8-20 parts of a reinforcing agent, 3-10 parts of a blocking agent, 0.3-1.5 parts of a weather-proof agent, 0.1-0.6 part of an antioxidant and 0.1-0.6 part of a lubricant. The material not only has excellent strength, toughness and dimensional stability, but also can play a role in vibration and noise reduction, can solve the common abnormal sound problem of current household appliances and improve the living environment of people, and is low in comprehensive cost and wide in application range.

The invention relates to an anti-friction bearing (1) having a bearing inner ring and a bearing outer ring (2) which is arranged radially outside the former, between which rolling bodies are positioned, wherein there is a single-piece decoupling element (3) radially outside the bearing outer ring (2) as vibration damper which engages around the bearing outer ring (2) at least in sections and rests with a bearing section (4) of at least partially cylindrical design on the outer circumferential surface of the bearing outer ring (2), wherein the bearing section (4) is interrupted in the axial direction by a spring section (5), in which the decoupling element (3) is spaced apart from the outer circumferential surface of the bearing outer ring (2). According to the invention, two bump-like projections (6) which extend at least partially over the circumference and on which the bearing section (4) rests are present on the outer circumferential surface of the bearing outer ring (2).

A shape for sheet metal stampings is provided that will minimize the radiation of sound from the panel, to thereby reduce or eliminate the need to add supplemental acoustical absorbing or barrier materials. The sheet metal panel shape includes a crown portion, a peripheral flange that extends around the boundary of the crown portion, a flat portion that truncates the crown, and a bead pattern that is formed in at least the flat portion of the panel, whereby the crown and the flat and the bead pattern cooperate to define a panel shape that has low sound radiation. The bead pattern can also extend part way or more into the crown portion.

The invention relates to a ceiling type acoustic device based on bean control. The ceiling type acoustic device based on the beam control comprises an audio product, a controller, a sounding module, a beam control module, a power amplifier module and a loudspeaker array, wherein the audio product is provided with a first end and a second end, the first end is connected with the controller in an interactive mode, the second end is connected with a wireless module in an wireless interactive mode, the controller is connected with the first end of the audio product in the interactive mode and is used for achieving the pairing of the sounding module and the audio product when command information is given by the audio product, the controller can also receive or generate expected information of a user, the sounding module comprises the wireless module which is connected with the second end of the audio product in the interactive mode, the beam control module is connected with the controller and the wireless module in electric mode, an input end of the power amplifier module is connected with an output end of the beam control module, an output end of the power amplifier module is connected with the loudspeaker array in an electric mode, the loudspeaker array comprises a plurality of loudspeaker units, and each loudspeaker unit is used for achieving electric-acoustic transformation.

The invention discloses an active control device for propeller shaft transverse vibration. The active control deice comprises a stern bearing, a middle bearing and a thrust bearing which are sequentially distributed in an axial direction of a propeller shaft, and further comprises an electromagnetic bearing assembly, wherein one end, close to the stern bearing, of the propeller shaft is connectedto counterweight, and the other end of the propeller shaft is connected to a motor; the electromagnetic bearing assembly comprises an electromagnetic bearing, a displacement sensor, a controller and apower amplifier, wherein the electromagnetic bearing is arranged on the propeller shaft; the displacement sensor is mounted on the electromagnetic bearing; the displacement sensor is connected to thecontroller; and the power amplifier is separately connected to the controller and the electromagnetic bearing. The active control device can reduce load of the stern bearing or the middle bearing, sothat bearing friction force is reduced or eliminated.

The invention provides a light wood structure sound-proof wall system and a manufacturing method thereof, and belongs to the technical field of building engineering. Through the structural design of discontinuous floor board and a double-deck sound-proof wall, under a premise of meeting the safety, and the purpose of reducing lateral sound transmission caused by the floor board and a top layer ceiling in the structurally horizontal direction is realized. Meanwhile, the joint connection of a wall body frame structure and a floor board frame structure is designed, and structural sound transmission between a partition frame and the floor board frame is reduced. The floor board structure is designed to reduce the influence of floor board impact sound on adjacent rooms in the perpendicular andhorizontal directions.

Systems and devices of the various embodiments may provide a low-drag, variable-depth acoustic liner having shared inlet volumes. Various embodiments may include a low-drag, variable-depth acoustic liner providing aircraft noise reduction. Acoustic liners according to the various embodiments may be used in engine nacelles and / or on external surfaces of an aircraft to reduce acoustic radiation. Acoustic liners according to various embodiments may provide increased broadband acoustic performance with less drag than conventional liners. Various embodiments may provide an acoustic liner with a reduced open area of the facesheet, and therefore reduced drag of the liner, when compared with conventional acoustic liners.

The invention discloses a bottom plate for an engineering machine cab. The bottom plate comprises an upper-layer flat plate, a lower-layer prestress reinforcement plate and a locating plate, the upper-layer flat plate, the lower-layer prestress reinforcement plate and the locating plate are all made of steel plates, the upper-layer flat plate is welded to the top face of the lower-layer prestress reinforcement plate, and the locating plate is welded to the bottom face of the lower-layer prestress reinforcement plate. Through the stamping technology, reinforcement ribs are formed on the surface of the lower-layer prestress reinforcement plate, and structural prestress is formed in the lower-layer prestress reinforcement plate. According to the bottom plate, the problems that vibration and sound radiation of the flat bottom plate of a current traditional engineering machine cab are obvious, and the bending and torsion resisting capacity is insufficient can be solved.

The invention discloses a ship noise reduction device. The ship noise reduction device is characterized by comprising a carrying board 1, a hollow damping mass block 2, a sound absorption material 3 and a band board 4. The hollow damping mass block 2 is installed on the carrying board 1. The middle portion of the carrying board is broken and the hollow damping mass block is fixed to the position between the two parts of the carrying board. The band board 4 is fixed to the hollow damping mass block 2. The sound absorption material 3 is installed on the band board 4. By the adoption of the ship noise reduction device, vibration and sound radiation in an engine compartment section of a ship are effectively reduced, the benefit ratio is high, economic cost is saved, the quality is guaranteed, and the production yield is increased.

The invention relates to a noise-insulating cladding for a panelled housing, in particular, for current track housings or for cable channels, whereby the base surface (202), the cover surface (204) and the lateral surfaces (206) of the housing (200) are formed from metal sheet. According to the invention, the cladding is embodied as a material strip (100), applied between two parallel wall pieces (206), lying flat on a wall piece (202), whereby the material strip (100) lies transverse to the longitudinal extension (L) of the housing (200) and is supported between parallel lateral surfaces (206) by means of spring forces.

The invention relates to a vibratory pile-driving apparatus having a carrier implement with a mast, on which, for the purpose of generating vibrations, a vibration generator with a transmission housing is supported, in which at least one pair of rotatably supported unbalanced units is arranged that are driven in a rotating manner by at least one rotary drive. According to the invention provision is made in that the transmission housing is surrounded by a soundproof housing, in which the transmission housing is supported by way of damping elements, and in that from the transmission housing at least one oil supply line and one oil discharge line are led out of the soundproof housing, wherein transmission oil can be cooled outside the soundproof housing.

The invention discloses a multi-layer sandwich-type composite structure and an automobile dash board using the same. The composite structure comprises an upper roof plate, a first sandwich-type body,and an intermediate separating plate which are successively connected. The first sandwich-type body comprises a plurality of first matrixes. A plurality of the first matrixes is arranged on a horizontal plane in periodic array. The first matrix is formed by four first crossed units. The four first crossed units are arranged along a diagonal line of four side faces of a cube, and the four first crossed units are successively connected and a first cavity is surrounded between the four first crossed units. Two neighboring first matrixes are connected through own first crossed units. The compositestructure is capable of greatly improving structural rigidity and strength, bending resistance, anti-penetration performance and different surface collision resistance. The first sandwich-type body is a single-layer lattice structure, and has higher energy absorption capability. In addition, the first cavity has a noise-reducing function.

A bearing bush is for a holder, which is for fastening a component, particularly of a fuel distributor, to an add-on structure. The bearing bush has an inner bush part, which is made of a metallic material, and an outer bush part, which is made of a metallic material, and an elastically deformable damping element. The outer bush part has a continuous recess, in which the inner bush part is situated. The damping element is situated between the inner bush part and the outer bush part. A holder having such a bearing bush is also specified. In addition, a fuel-injection system having a fuel distributor and at least one holder is specified, which is used for fastening the fuel distributor on an internal combustion engine.

The invention relates to a fuel injection system (10) having a high-pressure fuel pump (18) which has an intake valve (28), wherein a non-return valve (42) is arranged upstream of the intake valve (28) in the direction of flow of a fuel (12) in the fuel injection system (10), which blocks the return flow of a fuel volume, which has not been conveyed by the high-pressure fuel pump (18) into a high-pressure region (36), into a low-pressure system (32) of the fuel injection system (10).

The invention discloses a bottom plate for an engineering machine cab. The bottom plate comprises an upper-layer flat plate, a lower-layer prestress reinforcement plate and a locating plate, the upper-layer flat plate, the lower-layer prestress reinforcement plate and the locating plate are all made of steel plates, the upper-layer flat plate is welded to the top face of the lower-layer prestress reinforcement plate, and the locating plate is welded to the bottom face of the lower-layer prestress reinforcement plate. Through the stamping technology, reinforcement ribs are formed on the surface of the lower-layer prestress reinforcement plate, and structural prestress is formed in the lower-layer prestress reinforcement plate. According to the bottom plate, the problems that vibration and sound radiation of the flat bottom plate of a current traditional engineering machine cab are obvious, and the bending and torsion resisting capacity is insufficient can be solved.

The invention discloses a train noise-reducing wheel, which comprises a web (1), a rim (2) and a hub (3). An annular noise shielding plate (4) is fixed, the outer edge of the noise shielding plate (4) is in contact with the rim (2) of the wheel, and the inner edge is in contact with the hub (3) of the wheel. The wheel can suppress noise generation, hinder noise transmission, has good noise reduction effect, is easy to install, does not change the shape of the main body of the wheel, and is easy to popularize and implement.

The invention proposes a closed cavity type PVDF thin-film loudspeaker. The closed cavity type PVDF thin-film loudspeaker comprises a main structure and an impedance converter; the main structure comprises a PVD thin film, a sound absorbing material layer and a glass fiber reinforced plastics back cavity; the PVDF thin film has double-sided electrodes; the double-sided electrodes respectively leadout external electrodes; the PVDF thin film and the double-sided electrodes are subjected to insulation encapsulation, and parts of the external electrodes are exposed during the insulation encapsulation; an open surface of the glass fiber reinforced plastics back cavity is a cambered surface with a rectangular projection, and the PVDF thin film after being subjected to the insulation encapsulation is sealed and fixedly connected with the edge of the open surface of the glass fiber reinforced plastics back cavity through a sealant; the sound absorbing material layer is fixed inside the glassfiber reinforced plastics back cavity body, and the sound absorbing material layer is not in contact with the PVDF thin film; and the main structure is connected with an external standard power amplifier through the impedance converter. The closed cavity type PVDF thin-film loudspeaker provided by the invention can effectively improve the sound radiation efficiency of the PVDF thin-film loudspeaker and reduce the sound radiation behind the PVDF thin-film loudspeaker, so as to solve the problems of the driving difficulty of the PVDF thin-film loudspeaker, the poor low frequency effect and the noise pollution behind the loudspeaker.

The invention relates to a multi-stage piston compressor which comprises a compressor unit (1) having a plurality of air-cooled cylinders (10a-10c), the crankshaft (8) of said compressor unit being housed in a crankcase (6) and driving a motor unit (3) that is flange-mounted on an end face (2) on said compressor. On the opposing end face (4) of the compressor unit (1), a cooler unit (5) is arranged, mounted on said compressor unit and driven by the crankshaft (8), the integrated axial fan wheel (9) of said cooler unit blowing the generated cooling air substantially outwards along the compressor unit (1) and, in order to conduct cooling air externally in the region of said compressor unit (1), at least one air guide housing (7) which extends at least partially radially around the crankcase (6) in a curved manner being mounted on said cooler unit (5) on the air inlet side and being mounted on the compressor unit (1) crankcase (6) on the air outlet side such that the axial air flow which is generated by said axial fan wheel (9) is at least partially taken in by the air guide housing (7) and at least partially guided around the crankcase (6) in the radial direction so as to reach at least one cylinder (10a) arranged on the air outlet side of said air guide housing (7).