261 results about "Noise emission" patented technology

An assembly for cooling an electronic image assembly having a rear channel placed behind the image assembly and a heat exchanger for accepting ambient air. The system contains a first fan placed within the heat exchanger to force ambient air through the heat exchanger and the rear channel. A second fan may be used to force circulating gas through an interior portion of the display housing and through the heat exchanger in order to transfer heat to the ingested ambient air.

An assembly for cooling an electronic image assembly having a rear channel placed behind the image assembly and a heat exchanger for accepting ambient air. The system contains a first fan placed within the heat exchanger to force ambient air through the heat exchanger and the rear channel. A second fan may be used to force circulating gas through an interior portion of the display housing and through the heat exchanger in order to transfer heat to the ingested ambient air.

A 3D printer has a casing, a nozzle for printing, an extruder, a heating element, and a print bed. The casing encloses a region above and around the print bed to form a printing zone. Further, the 3D printer has features adapted for low-noise operation, and is already suitably quiet enough for use in a low-noise environment because it does not generate loud sounds. Specifically, in a quiet office with 37-38 dB of noise, noise emissions were measured while the present invention constructed a 3D printed model, and at six inches from the extruder on the 3D printer, the noise emissions measured 39-58 dB, at three feet away measured 38-43 dB, and at six feet away measured around 37-40 dB.

A combustor and combustor liner cap assembly for reducing noise emissions and acoustic dynamics during operation of a gas turbine generally includes a cellular solid media disposed in the combustor liner cap assembly. The cellular solid media absorbs noise emissions and acoustic dynamics, thereby reducing stresses and vibrations on the combustor assembly associated with operation of the gas turbine.

Rotor blades for wind power installations are known in many different forms. In a wind power installation the rotors or the rotor blades thereof represent the main source of sound. For reasons relating to acceptance and noise prevention laws, the aim should / must be that of minimizing the levels of sound emission as wind power installations are often also set up in the proximity of residential accommodation. The levels of sound emission which hitherto occur with a wind power installation or a wind power converter also mean that wind power installations are faced with resistance from populated areas because of the sound they produce and for that reason such installations can be accepted sometimes with difficulty or not at all as authorities responsible for planning permission refuse permission for wind power installations because of the existing environmental requirements, noise also being an environmentally polluting factor. Therefore the object of the invention is further to improve the noise emission of wind power installations. Wind power installation rotor blade comprising means for reducing the sound produced by a rotor blade, wherein the means is formed by a fluid-repellent layer and / or surface which is provided at least on a surface portion of the rotor blade.

The present invention is an improved AHU that can be easily architecturally disguised, made in a modular unit, have increased overall efficiency and ease of servicing, reduce radial noise emissions and allow for the direct adjacent placement of additional AHU's. This AHU has a cuboid structure with smooth side walls that are insulated and adapted for the attachment of aesthetic surface treatments, roof inset fans louvered end walls with door access. Heat removal can accomplished through angled heat exchangers also housed within the enclosure. Air filtration is also accomplished with angled filters. The improved aesthetic appearance of these units also eliminates the use of surrounding architectural parapet walls or screening units. The improved space effectiveness and modularity shall provide greater flexibility in building construction.

An arrangement to reduce noise emission generated by a wind turbine rotor blade is provided. The arrangement includes the rotor blade and a noise reduction device attached thereto. The rotor blade has a suction side and pressure side, leading and trailing edge sections with a trailing edge. The noise reduction device has an inner surface facing the rotor blade trailing edge section, and an outer surface opposite to the inner surface. The noise reduction device has a leading and trailing edge, both connecting the inner and outer surface. The noise reduction device is connected at the rotor blade trailing edge section by a connector. The inner surface has a pre-defined distance to at least one side of the rotor blade chosen so acoustic waves generated at the rotor blade trailing edge section are reflected by the inner surface to reduce noise emission generated by the wind turbine rotor blade.

A method for operating a cooling system for a fuel cell stack in a vehicle is provided. The method includes the steps of: determining a fan request for a variable speed fan disposed in the cooling system; employing a noise-comfort function to select a fan comfort request; and adjusting a speed of the variable speed fan in response to the fan request; wherein a noise emission by the variable speed fan is militated against. A cooling system for a fuel cell stack in a vehicle that employs the noise-comfort function is also provided.

According to the present disclosure, a method of operating a wind turbine including operating the wind turbine in a noise reduction mode based on at least one set point of a wind turbine parameter such that noise produced by said wind turbine remains below a predefined noise emission level, obtaining an actual air density related value, and applying a correction factor to the at least one set point of a wind turbine parameter is provided. The correction factor is determined in dependence of said actual air density related value.

A gate drive circuit for driving the gate of a power transistor switch comprising a gate drive sourcing circuit supplying gate drive current to the power transistor switch, the gate drive sourcing circuit initially providing a first current to the gate of the power transistor switch and then providing a second current to the gate of the power transistor switch; a circuit for driving the gate drive sourcing circuit, the circuit having a first input for driving the gate drive sourcing circuit to turn on the power transistor switch by providing the first current, the circuit further having a second input coupled to a voltage across the power transistor switch and being controlled by the second input to cause the gate drive sourcing circuit to provide the second current when the voltage across the power transistor switch begins to drop as the power transistor switch begins to turn on.

A system for reducing jet noise emission from an internally mixed gas turbine engine exhaust, comprising a fan / core flow mixer having a plurality of mixer lobes and a common flow nozzle having an equal number of tabs located along a circumferential edge of an aft end of the nozzle. There is a predetermined clocking relationship between the plurality of mixer lobes and the plurality of nozzle tabs that results in reduced exhaust noise emission, most evident in the lower frequency range. A method for reducing jet noise emission from an internally mixed gas turbine engine exhaust comprises selectively aligning a circumferential distribution of a mixed flow vorticity field produced by a fan / core mixer with a circumferentially distributed exhaust flow vorticity field produced by a modified common flow nozzle at an exit plane of the engine exhaust.

A stator or rotor of an electric motor or generator comprises a core formed of ferromagnetic material having a plurality of teeth arranged circumferentially about an axis. In one aspect of the invention, at least one retaining member connects the end portions of at least two of the teeth to each other in a manner inhibiting relative movement between said tooth end portions. By inhibiting relative movement between said tooth end portions, vibration is reduced. Vibration can also be reduced by welding interior surfaces of a core to each other. Reducing the vibration reduces the noise emissions of the rotor or stator during operation.

Problems of noise emission during transmission in successive time slots (A-B) in mobile telephony are solved by causing the transmitted power to change in a monotonic manner from a previous value to a new value. It is shown that this increases the transmission bit rate.

A fan case assembly includes a noise attenuation layer that is covered by a face sheet. The face sheet includes a first plurality of openings. The noise attenuation layer includes a plurality of individual cells that are in communication with at least one of the first plurality of openings. Noise energy is communicated through the first plurality of openings into the individual cells and dissipated to reduce noise emissions. A seam in the face sheet is covered to protect the underlying noise attenuation layer from damage by a retainer. The retainer is bonded to the face sheet over the seam and includes a second plurality of holes that communicates noise energy through the retainer to the noise attenuation layer. Communication of noise energy through the retainer provides an acoustically active seam that aids in the dissipation of noise energy and thereby reduces the level of sound emitted from the engine.

A feed pump includes an impeller with two rings of guide blades delimiting blade chambers. The rings of guide blades concentrically surrounding one another and have different angular intervals between guide blades. The angular intervals between the guide blades of each ring vary within a range of values and ranges of values of each ring of guide blades is different to avoid the additions of noise emissions the feed pump consequently has noises which cause particularly little disturbance.

A gate drive circuit for driving the gate of a power transistor switch comprising a gate drive sourcing circuit supplying gate drive current to the power transistor switch, the gate drive sourcing circuit initially providing a first current to the gate of the power transistor switch and then providing a second current to the gate of the power transistor switch; a circuit for driving the gate drive sourcing circuit, the circuit having a first input for driving the gate drive sourcing circuit to turn on the power transistor switch by providing the first current, the circuit further having a second input coupled to a voltage across the power transistor switch and being controlled by the second input to cause the gate drive sourcing circuit to provide the second current when the voltage across the power transistor switch begins to drop as the power transistor switch begins to turn on.

An apparatus and a method for active reduction of the noise emission from a jet engine having an air inlet, a gas outlet and an engine arranged between the air inlet and the gas outlet. A first acoustic transducer is arranged in the air inlet upstream of the engine and / or in the gas outlet downstream of the engine in order to convert sound waves into first signals that are a measure of the frequency, amplitude and phase of the sound waves. An electronic control unit converts the first signals into second signals. A second acoustic transducer is centrally arranged in the air inlet upstream of the engine and / or in the gas outlet downstream of the engine in order to convert the second signals into compensation sound waves whose frequency, amplitude and phase are such that the sound waves and the compensation sound waves at least partially cancel one another out.

As air passes through the airflow channels (46) between the blades (10) of a compressor impeller, boundary layers build up on the blade (10) surfaces. These low momentum masses of air are considered a blockage and loss generators. Ultimately, the boundary layer on the suction side of the blade (20) will separate, causing stall and reversed flow. Reversed flow will occur until a stable pressure ratio with positive volume flow rate is reached. When the pressure ratio becomes unstable again, the cycle will repeat. Introducing a slit (12) or a series of perforations (28) on the compressor wheel blade (10) allows the air to communicate between the pressure side (18) and the suction side (20) of the blade, which allows the boundary layer to stay attached longer. The invention allows for various shapes, positions, lengths and widths, locations, and arrangements of either a slit (12) or a series of perforations (28) on the compressor blade (10) in order to accomplish the objectives of delaying surge conditions by prolonging the boundary layer adherence to the suction side (20) of the compressor blade (10) and of maintaining a low level of noise emission, ease of manufacturing, and structural integrity.

The invention provides a method of controlling noise emission from a wind turbine comprising at least one rotor blade (1, 2, 3). The inventive method comprises steps of: Providing wind shear data comprising wind shear values as a function of height over ground; Determining an expected noise emission based on the wind shear data; and Controlling the wind turbine to reduce noise emission from the wind turbine in accordance with the expected noise emission.

The invention relates to an ecological intelligent machine room which has zero waste heat emission, zero waste water drainage and zero noise emission, integrates multiple systems, achieves integral software platform management, can achieve unattended operation and remote control, and is applied to the fields of the electric power industry, the electronic industry, automation and mechatronics. The machine room is composed of a power generating module, a power supply module, a backup power module, a monitoring module, a security module, a fire fighting module, a cabinet inner equipment module cluster, a super equipment cabinet cluster and a heat dissipation module thereof, a central control unit and application software IJF2013. The super equipment cabinet cluster and the heat dissipation module thereof form a kernel heat dissipation system of the ecological intelligent machine room, the kernel heat dissipation system is divided into two levels which comprise a main heat dissipation loop and a backup heat dissipation loop, the main heat dissipation loop ensures the zero waste heat emission, the zero waste water drainage and the zero noise emission of the cabinet inner equipment module cluster, and the main heat dissipation loop is switched to the backup heat dissipation loop in a seamless mode once the main heat dissipation loop is broken off. The iJFang2013 takes central control unit, with Ethernet connection, of all the function modules as a physical layer, and the management of the machine room is divided into a manual mode, an automatic mode and a remote mode.

The invention relates to a medical or dental-medical treatment instrument (1) having a rod-like handpiece (2) with the forward end region of which a tool (3) can be releasably coupled by means of a tool coupling (4), and the rearward end region of which can be releaseably coupled with a connection part (6) by means of a handpiece coupling (5), preferably a plug-in / turn coupling, the handpiece having: a grip sleeve (11) which forms an outer body of the handpiece (2), an oscillatory rod (13) which extends longitudinally in the grip sleeve (11) and is mounted therein radially or also axially elastically yieldingly, an in particular pneumatic oscillation generator (31) for transmitting oscillations to the oscillatory rod (13), and a sleeve (14) surrounding the oscillation generator (31). For reducing noise emissions, the sleeve (14) is of elastically compressible or sound-absorbing material.

A variable nozzle area jet pump is provided having a nozzle-sealing member resiliently urged to form a sealing closure. The sealing member is part of a normally non-passing pressure control valve that recirculates excess fluid back to the inlet of a positive displacement fluid pump. The fluid is recirculated with elevated pressure after a threshold fluid pressure is exceeded. The disclosed system provides for energy conservation and pump cavitation speed increase. The system may be integrated with an engine balance shaft module so as to provide low cost robustness to low speed gear noise emissions by application of the oil pump's drive torque to at lease one gearset.

An emergency release device for manual actuation of the parking lock of a shift-by-wire transmission. The emergency release device comprises a mechanical transfer device located between an emergency release actuator and the transmission and engages a pivoting lever mechanism arranged on a transmission shifting shaft. A characterizing feature of the emergency release device is that the pivoting lever mechanism comprises a primary pivoting lever connected to the transfer device, a secondary pivoting lever connected to the transmission and a unidirectional coupling element located between the primary and the secondary pivoting levers. The advantage of this device relates to reduced susceptibility to corrosion, wear and noise emission and easier correct adjustment of the transfer device during assembly, while a separate prestressing mechanism for the cable of the emergency parking lock release can be omitted.

The invention discloses a high-quality environment-friendly rice processing and producing method. The high-quality environment-friendly rice processing and producing method comprises the following steps of 1 grain detecting, 2 screening and residue removing, 3 drying, 4 stone removing, 5 magnetic separating, 6 rice husking, 7 husked rice separating, 8 thickness grading, 9 multi-level rice milling,10 rice grading, 11 color sorting and 12 polishing. According to the high-quality environment-friendly rice processing and producing method, dust and noise emission can be effectively controlled, recovery and incineration treatment is conducted on chips generated in the processing process, grain drying is conduced through a heat source generated in the incineration process, an environment-friendly waste recycling production technology is achieved, and then the energy-saving and environment-friendly effect is achieved.

The invention relates to an assembly-type integrated bathroom and a construction method thereof. The assembly-type integrated bathroom comprises foaming cement composite bottom plates, foaming cement composite wall plates, foaming cement composite top plates and bathroom equipment; dovetail groove type steel frame edge ribs are arranged in the plates, and each dovetail groove type steel frame edge rib is composed of an upper wing flange, a lower wing flange and a dovetail groove edge rib groove; an embedded part wedge block is arranged in each dovetail groove edge rib groove; all the plates are fixedly connected through bolts, connecting parts and the wedge blocks arranged in the dovetail groove edge rib grooves of the plates. The assembly-type integrated bathroom has the advantages that the foaming cement composite plates obtained through industrialized production are adopted, the fire resistance duration is larger than or equal to 4 hours, the sound insulation is larger than or equal to 42 decibels, raw materials forming the plates adopt inorganic materials and are non-combustible, and the comprehensive properties of energy conservation and environment protection, bearing and thermal insulation, heat insulation, fire resistance, durability, shock resistance, small mass, high strength and the like are achieved; installing operation is easy and convenient, rapidness and firmness are achieved, and environmental pollution and noise emission caused by traditional bathroom construction are reduced. The assembly-type integrated bathroom is an energy-saving and environment-protecting green building product.

The invention provides a method for updating a three-dimensional traffic noise map in conjunction with offline storage and instant calculation. The method comprises the following steps: dividing noise calculation into calculations for noise emission item related to traffic flow and noise degeneration item unrelated to the traffic flow; calculating the noise degeneration item only related to geographic elements in advance and offline storing in a database; while updating the three-dimensional traffic noise map, only calculating the changed noise emission item according to the change in urban road traffic flow state and calculating the final noise value by combining with the offline stored noise emission item, thereby reducing the calculation amount. For increasing the updating speed of the three-dimensional traffic noise map, the manner of computer cluster parallel computing is taken for accelerating the noise calculation and updating of the noise map. The distributed calculation system combined with the method has the characteristics of high load balance, high flexibility and excellent expansibility. The system matched with the optimized noise map updating algorithm can greatly reduce the calculation time and obviously increase the updating efficiency.

The invention discloses a thread turning process parameter optimization method for green manufacturing, which comprises the steps of 1) determining optimization variables such as the cutting speed Vcand the feeding amount f; 2) establishing a multi-objective optimization function; 3) determining constraint conditions; 4) optimizing the objective function to obtain a Pareto optimal solution set thereof; 5) determining the weight of each target attribute according to an AHP (Analytic Hierarchy Process) and RS (Rough Set) based combined weight determination method, and obtaining an optimal solution meeting actual processing requirements from the optimal solution set in the step 4. In the application process of the method disclosed by the invention, parameters in the model can be determined firstly according to the actual condition, then the model is solved by adopting the method so as to obtain the cutting speed Vc and the feeding amount f when the carbon emission, noise emission and dust emission are synthetically optimized, and finally a purpose of reducing the carbon emission, noise remission and dust emission is achieved through controlling mechanical equipment.

The invention relates to a method for influencing an automated transmission taking into consideration the tractional resistance with which the magnitude of an external tractional resistance can be determined easily and without need of data exchange with devices outside the vehicle, the same as independently of a digitalized road map of the area in which the vehicle drives and with low construction complexity.In particular a topographical information of the area in which the vehicle drives is obtained which allows a tractional resistance detection unit, optionally in combination with additional influencing variables in relation to the external tractional resistance, to act upon the controller of an automated transmission so that by shifting the gear change points or selecting a suitable program, reduces both the fuel consumption and the pollutant and noise emissions. Moreover, the driving comfort and the climbing capacity of the vehicle are improved by preventing, starting from a specific threshold, the switching of the automated transmission to neutral position and in the full load range of the prime mover than allows the witching to a higher gear if in the gear a minimum acceleration capacity of the vehicle is guaranteed.

The invention provides a noise reducing device, a manufacturing method thereof and a freezer and solves the problem of poor noise reducing effects in the prior art. According to the technical scheme, the noise reducing device comprises a tubular body, both ends of the tubular body are provided with necked openings, one of the necked opening is connected with a refrigerant inlet pipe, and the other necked opening is connected with a refrigerant outlet pipe; the inside of the tubular body is provided with at least one taper cap, the taper cap is provided with a plurality of silencing holes and at least two liquid separating holes. The invention also provides the manufacturing method of the noise reducing device and the freezer comprising the noise reducing device. The noise reducing device can fully release the pressure of jet flow of capillary pipes, diverse the jet flow through the taper cap to achieve gas-liquid separation, filter sound waves through the round holes in the taper cap, achieve reflection and attenuation of sound waves within a certain frequency band in a first chamber and a second chamber to effectively reduce noise, solve the problem of noise emission of the freezer system of a refrigerator and improve the auditory feeling of users.