146results about How to "Noise reduction effect" patented technology

A power transmission belt comprising a body comprising an elastomeric material and having tensile members running in a longitudinal direction, the body having a pulley engaging region having a profile; the pulley-engaging region comprising a fibrous nonwoven fabric material; characterized in that the fibers of the nonwoven material comprise acrylic fibers. The acrylic fibers are preferably micro-fibers of less than about 1.5 dpf and having an average diameter of 13.5 microns or less and an average length of about 1 to about 10 mm. The nonwoven material may be commingled with the elastomeric material in the pulley engaging region. Up to about 75% by weight of the fibers of the nonwoven material may comprise non-acrylic fibers such as other synthetic fibers, natural fibers, or cellulosic fibers.

An aircraft noise-reduction apparatus (10) for a landing gear (20) comprises a skeleton structure (14), which supports and acts to maintain the profile of a noise-reducing layer. The skeleton structure may comprise blades (16). The noise-reducing layer may have more than 10 apertures through which, in use, air can pass and may be in the form of a deformable mesh (12).

In order to solve the problem of noise generated in the sensorless control of the existing built-in permanent magnet synchronous motor based on the high frequency signal injection method, a permanent magnet synchronous motor rotor position observer with random frequency high frequency square wave voltage injection is provided, which belongs to the motor control field. The present invention includes: a random frequency signal generator for generating a random frequency injection signal v with the same frequency and phase quadrature inj and a random frequency demodulated signal v dem ; Envelope extraction means for demodulating signal v according to random frequency dem , to extract the α-axis high-frequency current i αh and β-axis high-frequency current i βh The envelope line of the α-axis high-frequency current envelope signal i is obtained α,pu and β-axis high-frequency current envelope signal i β,pu ; Quadrature phase-locked loop 3, used for the high-frequency current envelope signal i according to the α-axis α,pu and β-axis high-frequency current envelope signal i β,pu , to estimate the position of the rotor. The invention can be widely applied to the control system of the built-in permanent magnet synchronous motor, does not need additional hardware, and has obvious effects of reducing noise.

A power transmission belt comprising a body comprising an elastomeric material and having tensile members running in a longitudinal direction, the body having a pulley engaging region having a profile; the pulley-engaging region comprising a fibrous nonwoven fabric material; characterized in that the fibers of the nonwoven material comprise acrylic fibers. The acrylic fibers are preferably micro-fibers of less than about 1.5 dpf and having an average diameter of 13.5 microns or less and an average length of about 1 to about 10 mm. The nonwoven material may be commingled with the elastomeric material in the pulley engaging region. Up to about 75% by weight of the fibers of the nonwoven material may comprise non-acrylic fibers such as other synthetic fibers, natural fibers, or cellulosic fibers.

The invention discloses a table-type high-speed centrifugal machine, which comprises a motor, a rotor, a centrifugal cavity and a door cover, wherein the inner side face of the door cover is provided with at least one air ducting device, the door cover is provided with an air outlet and an interembeded air duct. One end of the interbedded air duct is connected with the air ducting device and the other end of the interbedded air duct is connected with the air outlet. The centrifugal machine has the advantages of ventilation and cooling by using the operational characteristics of the centrifugal rotor, simple structure, great reduction of manufacturing and operational cost and lower noise level. The centrifugal machine can achieve better cooling and radiation effect as well as low-noise effect with a self air duct structure instead of a complex and expensive compressor or semi-conductor cooling system and a cooling fan.

A low-noise liquid-cooled compressor of the invention has a liquid-cooled screw compressor with a pair of screw rotors which are meshed. The inhalation to the above-mentioned screw in the rotor supply of inhalation gas flow on the road I set up oil from the oil to the above I inhaled into the liquid flow path. According to this structure, even if the compressor and the speed of change in the frequency of occurrence of the noise changes to the functioning of the state in a variety of low-noise results obtained, mainly through the compressor to reduce the inhalation flow path and out to the external noise amplitude, in particular to reduce the inhalation side of the compressor body pulse amplitude in order to suppress noise.

The invention provides an assembly method of a two-stage compression heat pump air-conditioning and refrigerator system and a device used the method. The method is characterized in that a split-type air-conditioning outdoor system and a split-type refrigerator outdoor system are assembled together; the compressors of two different pressure levels of the same unit are used; the adjustment of the air and the refrigeration of the refrigeration are realized through the serial and parallel arrangement of the cooling pipeline, the control of the control valves, and the auxiliary function of the intermediate heat exchanger cold / heat exchange system; as the air-conditioning refrigerant cycling circuit and the refrigerator refrigerant cycling circuit arranged in parallel supply heat energy to the rooms and supply cold energy to the refrigerator when operating in opposite directions; the air-conditioning refrigerant cycling circuit and the refrigerator refrigerant cycling circuit supply cold energy to both the room and the refrigerator when arranged both in series and in parallel and operating in collaboration. The invention realizes the transfer between different work modes of the system through changing the cycling direction of the refrigerant of the system and the allocation of flow of the refrigerant. The different types of energy utilize each other, and the energy-saving and noise-reducing effects are obvious. The indoor machine can be arranged in an embedded type, which saves space and is beneficial for the beautification of the environment. The device is widely applicable to locations such as households, villas, hotels and motels, etc.

The invention relates to steel wire vibration isolator. It includes one the first fixed seat, one the second fixed seat, many steel wires connected between the former two. It has the advantages of ensuring safe reliability for the vibration isolation system while suffering impact, reducing structure high frequency noise, simple assembly, and convenient using.

The invention discloses an air purifier which comprises a case, a fan assembly and a filter element. A wind inlet and a wind outlet are formed in the case, the wind inlet is formed in the lower portion of a side surface of the case, and the wind outlet is formed in the upper portion of the case; the filter element is internally arranged at the bottom of the case, the tubular outer contour of the filter element is matched with the edges of the inner wall of the lower portion of the case, an exhaust channel which is positioned inside the filter element is formed in the filter element, an exhaust outlet is formed in the upper end of the exhaust channel, and a wind inlet side surface is arranged on at least one part of the outer peripheral surface of the filter element and is close to the wind inlet; the fan assembly is internally arranged on the upper portion of the case and is used for delivering air exhausted from the exhaust outlet to the wind outlet. According to the technical scheme, the air purifier has the advantage that noise can be prevented from being increased under the condition that high CADR (clean air delivery rate) values are guaranteed.

The invention provides a wide-band, low-noise, and small-sized high frequency power amplifier that has small temperature dependence of the gain and is excellent in input matching. A parallel circuit consisting of a resistor whose resistance depends strongly on temperature and a conventional resistor is inserted serially into a signal path in an input matching circuit of an amplification unit, and resistances of the resistors are set to appropriate values, for example, about 2 / 3 times an input impedance of the amplification unit.

An amplifying circuit arranged for converting an input signal into an amplified output signal comprising: an input node (11) at an input side of said circuit for receiving said input signal (pi); an output node (9) at an output side of said circuit for outputting said amplified output signal (io); a first gain element (M1) connected between said input and output nodes and provided for converting an input voltage taken from said input signal into a current for forming said amplified output signal; a negative feedback loop (3) over said first gain element, said negative feedback loop having first elements (5, 6) arranged for providing input matching; and a positive feedback loop (2) over said first gain element, said positive feedback loop having second elements (7, 8) arranged for providing additional input matching and gain enhancement of said first gain element.

An analog to digital converter (ADC) includes a cross switch array coupled between an input switch array and an integrator configured to alternately transfer charges from a first input capacitor and a second input capacitor to a first integration capacitor and a second integration capacitor thereby improving linearity problems caused by capacitor mismatching. The cross switch array may also be configured to transfer charges from the first input capacitor to the first integration capacitor and from the second input capacitor to the second integration capacitor during a first charge transfer time interval, and from the first input capacitor to the second integration capacitor and from the second input capacitor to the first integration capacitor during a second charge transfer time interval. A sensing system including and ADC consistent with the invention is also provided. Various methods of transferring charges in an ADC are also provided.

An aircraft landing gear (1) is described including a noise-reducing element that includes an air-deflecting surface, in the form of a fairing (4), and a perforated airflow-reducing region (8). In use, some air passes through the perforations, whilst other air is deflected by the fairing away from a noise-generating region of the landing gear. Noise caused by the passing of the landing gear through the air is therefore reduced.

The invention discloses a building sound insulation wall panel, which comprises a wall panel body, two protrusions are symmetrically arranged on the left side of the wall panel body, and a slot opening to the left is arranged on the protrusion, and the wall panel body The right side is provided with an insert block adapted to the slot; the adjacent wall panel body is connected with the protruding slot through the insert block, and the end surface of the adjacent wall panel body and the two protruding inner surfaces constitute A connecting hollow part; the wall panel body is sequentially provided with a decorative board layer, a load-bearing layer, a sound insulation layer, a waterproof layer, a concrete main layer, a glass magnesium board layer and a silent cushion layer from top to bottom. The invention has reasonable structural design, light weight, convenient assembly, high structural strength and good connection strength, which greatly reduces the influence of cold bridge effect on thermal insulation performance; Insulation, fire and earthquake resistance.

A noise-reducing fan system, comprising a motor, a fan body, a plurality of magnetic-inducing elements, a magnetic field generator and a noise-reducing sound source device, is provided. Here, the fan body is mounted on the motor. The fan body comprises a plurality of blades, on which the plurality of magnetic-inducing elements are disposed, respectively. The magnetic field generator, which may generate a magnetic field, is employed for driving the plurality of magnetic-inducing elements to vibrate the plurality of blades and generate a vibration sound, so that at least one portion of the noise emitted from the fan body as rotating may be counterbalanced. The noise-reducing sound source device is disposed on a predetermined position and may send out a noise-reducing sound, so that the noise-reducing sound may counterbalance at least the other portion of the noise emitted from the fan body as rotating.

A fast acting charge pump is provided which is suitable for use in a locked loop circuit where very short duration first and second adjustment pulses are produced by a phase detector. The first complement of the second adjustment pulses are used to switch the output of the charge pump through respective pairs of switching and associated biasing transistors, while a complement of the first and second adjustment pulses are respectively capacitively coupled to interconnection nodes of the pairs of switching and biasing transistors.

A semiconductor device includes: a semiconductor substrate including a first semiconductor layer, an insulation layer and a second semiconductor layer, which are laminated in this order; a trench penetrating both of the second semiconductor layer and the insulation layer and reaching the first semiconductor layer; and a third semiconductor layer. The trench has a ring shape on a principal surface of the substrate so that a part of the second semiconductor layer and a part of the insulation layer are surrounded with the trench. The third semiconductor layer is disposed in the trench through a first insulation film disposed on a sidewall of the trench so that the third semiconductor layer contacts the first semiconductor layer at a bottom of the trench.

A material of multifunctional modified asphalt used in bridge engineers, which is characterized by the raw materials and weight ratio as follows: 4-7 of styrene-butadiene-styrene block copolymer, 90-96 of asphalt, 3-6 of Urotropine, 8-12 of gum powder, 4-7 of styrene, 0.1 -0.3 of isoprene, 0.1-0.5 of linking agent. Its preparation is: adding the above raw materials on the ratio into a reactor with stirring apparatus to mix at a high temperature. The invention makes the asphalt pavement with properties of anti-rutting, cracking resistance, noise reduce, ice broken, and can be used in regeneration, irrigation slot, cold built and others.

The invention relates to a floor, in particular to a composite plastic floor. The composite plastic floor comprises plastic substrates; the upper edge of each plastic substrate is of an arc-edge square or rectangle; a wear resisting layer and a pattern printing layer are combined on the upper surface of each plastic substrate; a surface structure edge layer and a base structure edge layer are respectively arranged on two adjacent edges of two adjacent substrates; a surface layer and a slot layer are sequentially arranged on each surface structure edge layer from top to bottom, and a plurality of slots are horizontally arranged on the slot layer at intervals; and flanges which are embedded with and have equal quantity with the slots of the slot layer of the adjacent substrate are horizontally arranged on the base structure edge layer at intervals. The composite plastic floor provided by the invention has the advantages that the edges are prevented from raising, the falling is avoided, the manufacturing cost and the installing cost are low, the installation is simple and the dismounting is convenient, certain aesthetical impression is achieved, the duration is realized, damage by worms can be prevented, the elasticity is large and the noise is lowered.

The invention discloses a low-noise submarine. The low-noise submarine comprises a submarine body and is characterized by further comprising a silencing housing, wherein the silencing housing is arranged on the outer wall of the submarine body; a silencing gap exists between the submarine body and the silencing housing; and the silencing gap is a liquid storage gap or a liquid flowing gap. As the silencing housing is additionally arranged on the outer wall of the submarine body of the submarine, the liquid is stored in or flows through the silencing gap between the silencing housing and the submarine body so that a silencing layer is formed between the outer wall of the submarine body (in operation) and seawater; therefore, the integral silencing effect of the submarine is realized and the noise reducing effect is obviously improved. And moreover, the invention is advantaged in that the low-noise submarine is simply structured and simple to implement; the sound insulating effect of the low-noise submarine is extremely perfect by using seawater as a sound insulating material; and the submarine can be in the seawater during operation so that the seawater is easy to collect and zero cost is realized.

The invention provides a noise reduction device applied to refrigeration equipment. The refrigeration equipment comprises a compressor, a condenser, a capillary tube and an evaporator, and refrigerantcirculates among the compressor, the condenser, the capillary tube and the evaporator. The noise reduction device is connected between the capillary tube and the evaporator, the noise reduction device comprises at least one transition tube, the at least one transition tube forms passages allowing the refrigerant to flow therethrough, and the tube diameter of the passages gradually increases in the direction from the capillary tube to the evaporator. The invention further provides the refrigeration equipment with the noise reduction device. According to noise reduction device and the refrigeration equipment with the noise reduction device, the transition tubes form the refrigerant circulating passages with the inner diameter gradually increasing in the direction from the capillary tube tothe evaporator, so that the flow rate of the refrigerant flowing from the capillary tube to the evaporator can be reduced, and the effect of reducing the noise of the refrigeration equipment is achieved. In addition, the noise reduction device also comprises damping glue to achieve the effect of damping and sound absorbing, thereby further reducing the noise of the refrigeration equipment.

The invention provides an air-conditioner compressor mounting structure. The air-conditioner compressor mounting structure comprises a compressor, a chassis, compressor mounting feet which are arranged and fixed at the bottom of the compressor in an equilateral triangle mode, three chassis connecting pieces which are used for enabling the compressor mounting feet to be fixedly connected to the chassis, compressor damping feet which are placed on the upper end faces of the compressor mounting feet, and a cylindrical compressor damping block. An inward recessed arc-shaped structure which is in contact with the bottom of the compressor and is matched with the bottom of the compressor is arranged on the upper end face of the compressor damping block, a plane structure which coincides with the contact face of the chassis is arranged on the lower end face of the compressor damping block, and a damping groove is formed in the peripheral direction of the cylindrical compressor damping block. In the mounting process, the upper end face of the cylindrical compressor damping block is tightly attached to the bottom of the compressor and compresses the bottom of the compressor, the lower end face of the cylindrical compressor damping block is attached to a round damping block mounting groove formed in the chassis and compresses the round damping block mounting groove, and the round damping block mounting groove is placed in the central position among the three chassis connecting pieces. The compressor mounting structure effectively improves the stress condition of the overall mounting structure of the compressor.

The invention relates to an unmanned aerial vehicle forest flame recognition method based on deep learning, and belongs to the technical field of unmanned aerial vehicle vision and digital image processing. The method comprises the following steps: firstly, preprocessing a returned flame image by using histogram equalization and multistage median filtering algorithms, then detecting suspected flame pixels of a video by using a color space model algorithm, and then performing opening operation processing on the video image by using mathematical morphology. According to the invention, the improved median filtering is used to remove the noise of the video image; compared with common median filtering, the improved filtering not only reserves the special effect of the filtering in a phase analysis processing method of an optical measurement image, but also adopts a fringe center analysis method, the spatial density of impulse noise is relatively reduced by expanding a window, so that the details of the image are better, and meanwhile, the processing efficiency is improved.

The invention discloses a pipe cutting device. The pipe cutting device comprises a base, a retaining plate, a fixing column, a support column, a cutting device and a sound isolation plate, wherein the base is of a rectangle shape; the retaining plate is vertically arranged on the side surface of the base; the fixing column is fixedly arranged on the side surface, facing the upper surface of the base, of the retaining plate through a thread rod; one side surface, adjacent with the retaining plate, of the base is inwards depressed to form a slide groove; a slide block is fixedly arranged on the support column; the slide block is clamped into the slide groove, and can be slide along the length direction of the slide groove; the sound isolation plate is fixedly arranged on the other side surface, adjacent with the retaining plate, of the base, and is crossed with the retaining plate; the cutting device is arranged on the side surface, facing the base, of the support column, and can be slide along the length direction of the support column; the upper surface of the base is provided with scales which are matched with the cutting device. The pipe cutting device has the advantages that the problems of single function, poor cutting accuracy, complicated operation and low working efficiency of the denoising pipe cutting machine of the prior art are solved; the problems of noise production and pollution to surrounding environment in the cutting process are solved.

The invention discloses low-noise polyurea lubricating grease and a preparation method thereof. The low-noise polyurea lubricating grease is prepared from 85-90 parts by weight of base oil, 8-15 parts by weight of polyurea thickening agent and 1-4 parts by weight of hydroxyl compound. The polyurea lubricating grease prepared by the method disclosed by the invention has a better and stable vibration value, thereby reducing noise values of motors and low vibration bearings of office automation equipment and household appliances. The product has remarkable influence on a noise reduction effect.

A power source IC and noise absorption capacitors (decoupling capacitors) are formed on an inductor in such a manner that the noise absorption capacitors are provided on the input side and the output side, respectively. A micro-power source module can'thus be provided which is small in occupied area and height and can reduce conduction noise due to ground lines.

The invention discloses a noise eliminating device for reducing the exhaust noise of an internal combustion engine. The noise eliminating device comprises a shell, wherein the shell comprises an innershell and an outer shell, a cavity is formed between the inner shell and the outer shell, an air inlet pipe is arranged on the left side of the shell, the air inlet pipe extends into the inner cavityof the shell, a first baffle is arranged in the inner cavity of the shell, a buffer groove is formed in the middle of the left side of the first baffle plate, the buffer groove and the air inlet pipeare located on the same horizontal plane, and noise eliminating pipes are arranged on the periphery of the buffer groove. Through the arrangement of the buffer groove, the airflow can play a role inbuffering when coming out of the air inlet pipe, and the air flow can circularly flow on the left side of the first baffle to reduce the noise; sound absorbing cotton is arranged on the inner surfaceof the buffer groove, so that when the air flow is transmitted to the buffer groove, the effect of absorbing noise is achieved; the noise eliminating pipes are arranged, so that air flow is transmitted to the right side of the first baffle from the left side of the first baffle; and first noise eliminating holes are formed, so that the energy of the air flow in the noise eliminating pipes is prevented from being attenuated, and the effect of noise eliminating is achieved.