13results about How to "Guaranteed noise" patented technology

The invention belongs to the field of engine blade testing, and discloses a vibration excitation device and method with adjustable vibration excitation frequency. A motor with adjustable rotating speed is arranged on the mounting plate; a first synchronous pulley is arranged on an output shaft of the motor; a driving crankshaft is arranged on the mounting plate, a connecting plate is arranged on the driving crankshaft, and a connecting part for connecting an engine blade and a tool thereof is arranged on the connecting plate; a transmission belt is arranged on the first synchronous pulley and is connected with a second synchronous pulley arranged on the driving crankshaft; a rotating speed sensor for acquiring the rotating frequency of the driving crankshaft is arranged on the mounting plate. By adjusting the rotating speed of the motor, power transmitted by the transmission belt can be accurately controlled, then the rotating speed of the driving crankshaft is changed, flexible adjustment of the excitation frequency is achieved, diversified experiment and production requirements are met, and different vibration requirements for engine blades and tools of the engine blades in different testing or working environments can be met; and by accurately controlling the excitation frequency, a vibration environment closer to an actual working state can be simulated, so that the accuracy and the reliability of the test are improved.

The utility model relates to the technical field of photoelectricity, in particular to a photoelectric conversion circuit for an omnidirectional photoelectric receiver. Comprising a multi-stage signal amplification circuit, a signal filtering and interference source processing module, a pulse level output circuit and a power supply unit module, the multi-stage signal amplification circuit is used for amplifying the current signal and converting the current signal into a voltage signal with a symmetrical waveform; the signal filtering and interference source processing module is used for carrying out de-noising processing on the voltage signal in the photoelectric conversion circuit; the pulse level output circuit adopts a hysteresis comparator circuit design and is used for converting the voltage signal into a digital pulse signal; the power supply unit module comprises a single-power-supply low-ripple power supply unit and a reference voltage source unit, the single-power-supply low-ripple power supply unit is used for providing power for the photoelectric conversion circuit, and the reference voltage source unit is used for providing output limiting level. The photoelectric conversion circuit provided by the utility model can effectively adapt to an omnidirectional photoelectric receiver, and realizes a high-speed photoelectric conversion function.

The utility model discloses a large-displacement high-rotating-speed reciprocating piston type compressor unit for pipeline gas transmission. The device comprises a skid-mounted base, and an air cooler, an air inlet separator, a first-stage air inlet buffer, a compression host, a first-stage air outlet buffer, a first-stage air outlet separator, a second-stage air inlet buffer, a second-stage air outlet buffer, a second-stage air outlet separator and a control device which are arranged on the skid-mounted base, wherein a first-stage air cylinder and a second-stage air cylinder are arranged in the compression main machine; a primary cooler and a secondary cooler are arranged in the air cooler; in the air inlet direction, the air inlet separator, the first-stage air inlet buffer, the first-stage air cylinder, the first-stage exhaust buffer, the first-stage cooler, the first-stage exhaust separator, the second-stage air inlet buffer, the second-stage air cylinder, the second-stage exhaust buffer, the second-stage cooler and the second-stage exhaust separator are sequentially connected through pipelines. According to the large-displacement and high-rotating-speed reciprocating piston type compressor unit for pipeline gas transmission, stable operation of the compressor at high speed and high power can be guaranteed, and the service life of the compressor is guaranteed.

The invention discloses a range hood which comprises an exhaust fume collecting hood and a fan system, the fan system further comprises an upper air inlet, a lower air inlet, an exhaust fume collecting hood, an exhaust fume collecting hood and an exhaust fume collecting hood, and the upper air inlet is formed in a shell of the fan system, penetrates through the shell of the fan system and is communicated with the air inlet end of a fan of the fan system; the flow guide cover is arranged in the upper air inlet in a penetrating manner, an outlet of the flow guide cover corresponds to a fan air inlet end of the fan system, the flow guide cover extends in the height direction of the range hood, and an inlet of the flow guide cover extends outwards from a shell of the fan system; the driving part is arranged on the shell and used for driving the flow guide cover to do reciprocating motion in the height direction of the extractor hood, the calculation formula of the ratio coefficient of the flow of the upper air inlet to the total flow of the extractor hood is shown in the specification, delta is the ratio of the flow of the upper air inlet to the total flow of the extractor hood, and delta is the ratio of the flow of the upper air inlet to the total flow of the extractor hood. S is the stroke of the inlet of the flow guide cover in the height direction of the range hood.

This utility model relates to the field of bearing processing technology and discloses a drilling device for bearing production. The device includes a body assembly and a support plate. The top of the support plate has a moving groove, and the outer periphery of the top of the support plate has an installation groove. This utility model uses three circumferentially distributed adjusting components and a double-sided gear linkage mechanism to synchronously drive multiple clamping parts to move radially, achieving precise concentric clamping of the inner and outer rings of bearings of different diameters. The transmission structure of the lead screw and the driven bevel gear ensures consistent displacement of each clamping part. Combined with the rubber anti-slip texture design, it effectively prevents bearing slippage and reduces surface damage during clamping. The dual positioning mechanism of the positioning plate and the clamping plate further ensures strict concentricity of the inner and outer rings, significantly improving the drilling position accuracy, effectively reducing vibration and noise problems caused by eccentricity, and extending the service life of the bearing.

The utility model provides an anti-seismic structure of an automobile interior drawer, which belongs to the technical field of vehicle-mounted drawers and aims to solve the problems that plastic materials are short in service life due to abrasion in the use process, noise is easy to generate and user experience is affected if a gap between a drawer box and a panel is increased, and the anti-seismic structure comprises a mounting main body and a box body arranged in the mounting main body in a sliding manner, a plurality of mounting holes are formed in the mounting main body, anti-shaking assemblies are arranged in the mounting holes in a penetrating manner, each anti-shaking assembly comprises a main shaft clamped in the corresponding mounting hole, a ball head is arranged at one end of each main shaft, a tail part is arranged at the other end of each main shaft, a clamping cone is arranged between each tail part and the corresponding main shaft, the clamping cones abut against the mounting main body, and the ball heads are hemispherical and clamped between the mounting main body and the box body.

The application claims a high-gain operational amplifier circuit for Sigma-Delta ADC. The circuit comprises a main operational amplifier, a gain-improving auxiliary operational amplifier, a bias circuit and a switched-capacitor common-mode negative feedback circuit. The main operational amplifier serves as the main body of the circuit, has a high gain and a wide bandwidth; the auxiliary operational amplifier improves the output impedance and effectively improves the DC gain of the operational amplifier; the bias circuit is used to provide appropriate DC bias voltage for the main operational amplifier and the auxiliary operational amplifier; the switched-capacitor common-mode negative feedback is used to stabilize the output common-mode voltage. The application uses the auxiliary operational amplifier to improve the gain, ensures a high input-output swing of the operational amplifier, improves the DC gain of the operational amplifier, adopts a symmetrical switched-capacitor common-mode negative feedback, ensures the bandwidth range and reduces the nonlinearity of the circuit.

The utility model provides an electronic expansion valve which comprises a valve seat assembly, a first valve needle assembly, a second valve needle assembly and a silencing circulation piece, and a valve seat cavity, a large valve port and a second circulation hole communicated with the valve seat cavity are formed in the valve seat assembly. A small valve port is formed in the first valve needle assembly; the second valve needle assembly is used for controlling opening and closing of the small valve port and controlling movement of the first valve needle assembly. The first valve needle assembly is used for controlling opening and closing of the large valve port; wherein the noise reduction circulation piece is fixedly arranged at the end, close to the large valve port, of the small valve port, a plurality of through holes are formed in the noise reduction circulation piece, and the through holes communicate with the large valve port and the small valve port correspondingly so as to conduct flow division and noise reduction on fluid circulating between the large valve port and the small valve port. According to the utility model, the fluid can be effectively shunted by the plurality of through holes when passing through the silencing circulation piece, so that the noise of the fluid during flowing is reduced, the noise of the switching valve of the electronic expansion valve is reduced, and the use comfort of a user is improved.

The present invention relates to an air-controlled controller for extracting odors triggered by a manual air-controlled controller, comprising a shell and a valve core assembly installed inside the shell; the outer end of the shell is provided with a control interface, an air interface, a first output interface, a first input interface, a second output interface, a second input interface and a third input interface; the valve core assembly comprises a valve stem which moves by changing the air pressure at the control interface, a corrugated diaphragm fixedly connected to the valve stem, and a reset spring for resetting the valve stem movement; the present invention is suitable for vacuum toilets with air extraction function, and vacuum toilets with two-in-one odor extraction and water extraction. The overall structure is simple and compact, and the functionality is strong. The movement of the valve stem along the second cavity is achieved by changing the air pressure at the control interface. The problem of active odor extraction and maximum toxin removal of the vacuum toilet can be solved during operation. At the same time, the reasonable structural design can effectively reduce the noise generated during operation.

The embodiment of the application provides a kind of vehicle-mounted projection equipment and vehicle, it is related to vehicle-mounted projection technical field.The vehicle-mounted projection equipment includes: shell, including top plate, bottom plate and the side plate extending along height direction, top plate and bottom plate are oppositely arranged, top plate, bottom plate and side plate enclose the accommodating space of inside hollow, wherein top plate is used to fix vehicle-mounted projection equipment;Air inlet is provided on side plate, and air outlet is provided on bottom plate;Projection module is installed in accommodating space, and can be projected by shell;At least one radiator is installed in accommodating space, and radiator is correspondingly arranged with air inlet;At least one cooling fan is installed in accommodating space, and is arranged with the dislocation of radiator, and is correspondingly arranged with air outlet, and the air outlet direction of cooling fan is towards air outlet.Using the vehicle-mounted projection equipment, the noise can be reduced while guaranteeing the heat dissipation performance of vehicle-mounted projection equipment.

The invention discloses a photoelectric detector circuit capable of adaptively eliminating the direct current bias influence of a photodiode. The photoelectric detector circuit comprises a photodiode module, a TIA module, a power divider module, a low-pass filter module, an inverse proportion amplification module, a reference voltage module, a summing circuit module and a band-pass filter module. When the photodiode module outputs changed direct current bias current, the low-pass filter module and the inverse proportion amplification module extract direct current bias components and feed the direct current bias components back to the in-phase end of the TIA module, and the band-pass filter module filters interference signals outside the bandwidth and retains detection alternating current signals. And the feedback voltage and the reference voltage are added to serve as the N-stage bias voltage of the photodiode module. The reference voltage connected with the in-phase end of the TIA module and the N pole of the photodiode module is self-adaptive change voltage, signal saturation caused by direct current bias is avoided, the voltage difference between the N pole and the P pole of the photodiode module is stabilized, and the stability and noise performance of the photoelectric detection circuit are improved.

The utility model discloses a high-brightness tunnel light source module with an air cooling heat dissipation function. The high-brightness tunnel light source module comprises an arched outer cover and two light source assemblies. Each light source assembly is provided with an air cooling heat dissipation structure and a detachable connecting structure. The arched outer cover is also provided with a diffuse reflection coating; each air cooling heat dissipation structure comprises two pipelines, an air inlet and an air outlet, the air inlet is provided with an air pipe connector, and the air outlet is provided with an exhaust silencer. According to the utility model, the air cooling heat dissipation structure is arranged to take away heat for heat dissipation through air flow, so that the heat can be quickly guided out through a flow channel, and the heat dissipation effect is improved; the exhaust silencer is arranged to reduce noise during exhaust, vibration is reduced, and the stability of light irradiation is guaranteed; the base and the lamp panel can be conveniently connected or detached through the detachable connecting structure, maintenance replacement is facilitated, steps and time are saved, maintenance efficiency is improved, and the working efficiency of follow-up illumination is guaranteed.

The invention discloses an auxiliary heat dissipation device for installation of a computer graphics card, and relates to the technical field of heat dissipation, the auxiliary heat dissipation device comprises a graphics card body, a temperature sensor is fixedly connected in the graphics card body, and an auxiliary heat dissipation mechanism for assisting heat dissipation of the graphics card is arranged in the graphics card body; an auxiliary cleaning mechanism used for cleaning dust is arranged on the outer surface of the display card body, an auxiliary heat dissipation mechanism can adjust the deflection angle of fan blades, by optimizing the inclination angle of the fan blades, the air output of a fan can be increased, more cold air can flow through a radiator, and therefore the heat dissipation efficiency is improved, and the service life of the display card is prolonged. The air pressure of the fan can be increased by adjusting the angles of the fan blades, so that airflow can more effectively penetrate through the heat dissipation fins to help take away heat, and compared with manual dust blowing or wiping with cloth, the auxiliary cleaning mechanism can more thoroughly remove dust which is difficult to touch on the heat dissipation net, reduce dust accumulation and improve the heat dissipation efficiency. Noise generated during heat dissipation is reduced, and the service life of the fan is shortened and prolonged.