71results about How to "Suppress vibration noise" patented technology

In accordance with the present invention an aircraft floor panel is provided comprising a honeycomb core element having an upper core surface, a lower core surface, and a core thickness. An upper face sheet assembly is mounted to and seals the upper core surface and includes at least one upper material sheet impregnated with an upper epoxy resin. A lower damping face sheet assembly is mounted to and seals the lower core surface and includes at least one lower material sheet infused with a highly damped lower epoxy resin. The lower damping face sheet assembly dampens vibrational noise.

The invention discloses a polyphase permanent magnet synchronous motor current waveform optimal control method, comprising the following steps of A, current reference value coordinate transformation; B, current multiple proportion resonance regulation; and C, coupling compensation. In the control method, based on polyphase permanent magnet synchronous motor vector control, a polyphase synchronous rotating coordinate system current reference value is transformed to a current reference value of each phase in a polyphase static coordinate system through polyphase coordinate transformation, the current reference value of each phase and a current feedback value of each phase of a motor are respectively subjected to improved multiple superposition proportion resonance regulation, and a resonance separation method is introduced, decoupling is realized by feed-forward compensation, and floating tracking and harmful subharmonic restraining for highly dynamic property fundamental waves and usable subharmonic are realized. The method can restrain the adverse impacts, such as motor loss, torque ripple and vibration noise, caused by a harmful harmonic current of the polyphase motor, can explore the positive effects of the usable harmonic current, gives full play to the advantages of the polyphase motor and improves the system performance.

The invention relates to an asynchronous starting permanent magnet synchronous motor rotor based on permanent magnets with different residual magnetic densities, and belongs to the field of permanent magnet motors. The asynchronous starting permanent magnet synchronous motor rotor comprises a rotating shaft, a starting cage, a rotor iron core and the permanent magnets, wherein 2p VVV-shaped permanent magnet slots encircling the rotating shaft are uniformly formed in the rotor iron core; a first permanent magnet and a second permanent magnet are arranged in a first V-shaped slot; a third permanent magnet and a fourth permanent magnet are arranged in a second V-shaped slot; a fifth permanent magnet and a sixth permanent magnet are arranged in a third V-shaped slot; and magnetism isolation slots are reserved between the permanent magnets. On the premise that the stable-state running performance is not reduced, the cost of an asynchronous starting permanent magnet synchronous motor is effectively reduced, and the no-load air gap magnetic density waveform sine distortion rate is reduced; harmonic waves are effectively suppressed; the efficiency of the motor is improved; the torque ripple is reduced; and the vibration noise is reduced.

There is provided a microphone that can suppress vibration noise stemming from mechanical vibrations and that outputs a collective signal having superior quality.There is provided a microphone comprising a first capacitance section M1 having a first movable electrode 101 and a second electrode 102 disposed opposite the first electrode 101 and a second capacitance section M2 that has a first movable electrode 111 and a second electrode 112 disposed opposite the first electrode 111; a first amplifier 201 that amplifies a signal from the first electrode 101 of the first capacitance section M1 and a signal from the second electrode 112 of the second capacitance section M2; and a second amplifier 202 that amplifies a signal from the second electrode 102 of the first capacitance section M1 and a signal from the first electrode 111 of the second capacitance section M2.

The invention discloses an adjustable damping device for a ship base. The adjustable damping device for the ship base comprises webs (1), a flat plate (2), a vibration isolating cushion (3), a spring assembly (4), a base (5), base stand bars 5 (1), a base support 5 (2), vertical bolts (6), a supporting block (7), transverse bolts (8), an arc-shaped toggle plate (9), a foot pad (10), fixing plates (11) and fixing bolts (12). By the adoption of the adjustable damping device for the ship base, a whole ship can be better hidden, and the comfort of the whole ship is improved. The adjustable damping device for the ship base has the advantages of being reasonable, simple, easy to manufacture and low in cost.

A silent chain transmission utilizes two different kinds of link plates. In a first kind of link plate, the inner flank pitch line is farther than the outer flank pitch line from the chain pitch line. In a second kind of link plate the inner flank pitch line is closer than the outer flank pitch line from the chain pitch line. Every four successive links includes at least one link composed of one type of link plate and at least one link composed of the other type of link plate.

A vibration-suppressed transformer is fixed to a base plate and includes a magnetic lower core, two or more magnetic upper cores, primary and secondary coils. The lower core is on the base plate. The upper cores are arranged face to face over the lower core. The coils are arranged between the lower and upper cores. Each upper core contacts the lower core, on an outer side of the coils, with a first gap being provided between the upper and lower cores, on an inner side of the coils. The upper cores are extended towards each other from the outer to the inner side of the coils, with a second gap being provided therebetween. The second gap is provided therein with a non-magnetic pressing member to press the lower core against the base plate, on an inner side of the coils.

A heat resistant air hose which is excellent in oil-bleeding resistance and causes reduced vibration noise is provided. The heat resistant air hose has an inner layer formed of an inner layer material comprising silicone rubber as a major component thereof; and an outer layer provided on an outer periphery of the inner layer and formed of an outer layer material comprising acrylic rubber as a major component thereof, and the acrylic rubber contains not less than 50 wt % of ethyl acrylate and has a dissipation factor (tanδ) of not less than 0.09 at 150 ° C. and a storage elastic modulus (E′) of not less than 7.0 MPa.

The invention discloses a sandwich plate vibration absorbing structure based on micro local resonance subarrays. The sandwich plate vibration absorbing structure comprises a sandwich plate and at least one resonance subarray arranged in the sandwich plate, wherein each resonance subarray comprises a pair of parallel installation limiting supports and a plurality of vibrator units suspended between the installation limiting supports, and the vibrator units are used for absorbing low-frequency vibration energy from outside. The resonance subarray is arranged in the sandwich plate, so that the sandwich plate has a good sound insulation property at the low frequency, particularly near the low order natural frequency of the sandwich plate. The sandwich plate vibration absorbing structure has the advantages of low cost, simple control system and high reliability.

The invention relates to a permanent magnet synchronous motor for weakening cogging torque of a built-in permanent magnet motor; a motor shaft passes through a rotor and is fixed with the rotor; the rotor is located on the inner side of a ring-shaped stator; the stator comprises a stator core and a motor winding; the motor winding is wound on a stator slot of the stator core; the rotor comprises permanent magnet poles in even pairs; two permanent magnets are arranged in the permanent magnet poles; the two permanent magnets are in a "V" shape; the "V" shaped sections of the two permanent magnets have the same polarity in the radial direction; the permanent magnets in the adjacent permanent magnet poles have the opposite polarities; each permanent magnet pole on the outer periphery of the rotor is an arc, the radius of which is smaller than the radius of the ring-shaped inner wall of the stator core; the arc corresponding to each permanent magnet pole is eccentric, wherein the eccentricdistances of the arcs of the adjacent permanent magnet poles are different; and the eccentric distances of the arcs of the separated permanent magnet poles are the same. Such a rotor structure can weaken the cogging torque.

The invention discloses a rotor core of a segmented skewed-pole motor and a permanent magnet synchronous motor. The rotor core comprises a plurality of rotor core sections which are mutually staggeredat a preset angle, and the rotor core sections are formed by laminating rotor punching sheets; magnetic steel grooves are distributed in each rotor core section along the circumferential direction, and magnetic steel can be arranged in the magnetic steel grooves; a plurality of axially-penetrating auxiliary grooves are formed in the outer circumferential face of each rotor core section, the positions and / or the section shapes of the auxiliary grooves in each rotor core section are not completely the same, and the auxiliary grooves are used for restraining torque pulsation and vibration noisegenerated when the motor rotates. According to the scheme, the plurality of axially-penetrating auxiliary grooves are formed in the outer circumferential surface of each rotor core section; and the positions and / or the section shapes of the auxiliary grooves on the rotor core sections are not completely the same, so that the torque pulsation and the radial electromagnetic force generated by the rotor core of each section are respectively suppressed at a relatively low level, the overall torque pulsation and the radial electromagnetic force of the motor are reduced, and the vibration noise of the motor is effectively suppressed.

The invention discloses a noise-reduction damping device of a train wheel. The structure of the noise-reduction damping device is characterized in that a noise shielding plate is formed by alternately bonding and superimposing at least two circular ring-shaped metal plates (3a,3b) and at least one circular ring-shaped viscoelastic damping layer (4); the outer circumference of the noise shielding plate is fixed on the rim (1a) of a wheel (1) through an outer mounting ring (2) by screw threads; and the inner circumference is clamped on a hub (1c) and an axle (1d) through a clamping ring (10). The damping device has good noise-reduction effect and does not change the shape of the main body of the wheel, thereby being easy to popularize and implement.

The invention provides a terahertz low-noise communication system transmit-receive front end based on GaAs monolithic integration, and belongs to the technical field of terahertz wireless communication, the terahertz low-noise communication system transmit-receive front end comprises an intermediate frequency circuit and a terahertz circuit, the terahertz circuit comprises a local oscillator frequency tripler, a local oscillator homodromous 3dB filtering coupler, a radio frequency 180-degree filtering coupler and two terahertz GaAs monolithic integration subharmonic mixers; the local oscillator equidirectional 3 dB filtering coupler and the radio frequency 180-degree filtering coupler comprise an annular cylindrical resonant cavity and four rectangular waveguides, the annular cylindrical resonant cavity is divided into a large fan annular resonant cavity and three small fan annular resonant cavities through four fan annular grooves, and the central angle of the large fan annular resonant cavity is twice that of the small fan annular resonant cavities; and the four rectangular waveguides are correspondingly connected with the four sector-ring-shaped resonant cavities respectively. According to the invention, the local oscillator same-direction 3dB filtering coupler and the radio frequency 180-degree filtering coupler which have coupling and filtering functions are adopted, so that the low local oscillator noise suppression transceiving front end is realized.

The present invention discloses a device and method for actively suppressing the jitter of a test light path. The device is formed by beacon light, a light splitter, a piezoelectric fast reflector anda control computer. The overall method comprises steps of transmitting the beacon light at a test light path detection end, using the light splitter to couple and merge the test light, and reverselytransmit the light in the light path to a light entrance end of the test light path. The light entrance end of the test light path is equipped with the piezoelectric fast reflector, the light splitterand a detection camera. Through the light splitter, the beacon light is separated from the test light, the detection camera is used to collect light spot jitter which is test light path jitter. The control computer uses a centroid algorithm to calculate a beacon light miss distance and controls the piezoelectric fast reflector to compensate for the jitter. According to the device and the method,the jitter caused by a platform and other reasons in the test light path can be effectively res suppressed.

The invention relates to the field of ship power, and discloses a condensing device with symmetric nozzles. The condensing device comprises a condensing chamber; a cooling water inlet pipeline and a plurality of cooling branch pipes are mounted in the condensing chamber; each cooling branch pipe comprises two tail-stage branch pipes which are symmetrically arranged; and each tail-stage branch pipecommunicates with the cooling water inlet pipeline, and a plurality of groups of jet holes matched with each other are formed in each two symmetrically-arranged tail-stage branch pipes along the way.According to the condensing device with the symmetric nozzles provided by the invention, a traditional jet type condenser water chamber and baffle plate are saved, the cooling branch pipes are directly arranged in the condensing chamber, through the jet holes symmetrically formed in the tail-stage branch pipes, cooling water films are formed through impacting, so that for the condensing device with the symmetric nozzles, the water films can be directly utilized for cooling exhaust steam, and thus not only is the structure of the condensing device simplified, but also the compactness and condensing efficiency of the device are improved. Compared with the mode that jet flow impacts the baffle plate to form cooling water films, the mode provided by the invention is more direct, the quality of the water films is more convenient to regulate and control, and meanwhile, vibration noise is restrained.

The invention discloses a device for suppressing vibration noise of a steel rail. The device comprises the steel rail, steel cavities, elastic material layers, viscoelastic material layers, lead ballsand outer wrapping layers, wherein the steel cavities are arranged on the two sides of the steel rail; and the elastic material layers are arranged between the steel cavities and the steel rail, theelastic material layers are connected with the surfaces of rail webs on the two sides of the steel rail, and meanwhile, the steel cavities are connected with the elastic material layers. According tothe device for suppressing the vibration noise of the steel rail, the lead balls with different radii are adopted in the steel cavities to form particle damping elements, the strong nonlinear behaviorof granular particles makes the inherent damping characteristics of the granular particles change with the excitation level so that the response level, at the resonance peak, of the steel rail can beeffectively suppressed, the vibration absorption frequency band can be widened, and the vibration reduction effect of the particles is not influenced by the negative impact of large damping; and viscoelastic damping materials are adhered to the inner walls of the steel cavities, the steel rail vibrates to drive the lead ball particles to vibrate, collision and friction behaviors are generated among the particles to dissipate part of energy, and then vibration is reduced.

The invention relates to a low-noise centrifugal pump with a staggered non-uniform symmetric impeller / guide vane structure. According to the low-noise centrifugal pump with the staggered non-uniform symmetric impeller / guide vane structure, a conventional uniform and symmetric arrangement mode of impeller vanes is broken through, the arrangement angles between impellers and adjacent vanes of the guide vanes are designed according to the periodic trigonometric function relation, the arrangement angles between the vanes conform to the periodic distribution rule, the superimposed effect of pressure waves generated by dynamic and static interference between fluid at outlets of the impellers and the guide vanes is restrained, and the pressure pulsation amplitude is reduced. Meanwhile, rib plates are arranged between the impellers and the guide vanes, the impellers and the guide vanes are arranged in a staggered mode through the rib plates, the flow of liquid flowing out of impeller runners and guide vane runners at the same time is reduced, the dynamic and static interference effect between the movable vanes and the static vanes of the centrifugal pump is further weakened, the purpose of reducing vibration noise is achieved, and on the premise that the efficiency is not influenced, the operation stability of the centrifugal pump is improved.

The present invention provides a control method for inhibiting single-phase capacitor run motor vibration noise. The circuit of the method comprises a primary winding, a secondary winding, a start capacitor and an adjustable run capacitor. The induction electromotive force of the secondary winding when the primary winding is powered and the secondary winding is disconnected and the induction electromotive force of the primary winding when the secondary winding is powered and the primary winding is disconnected are detected when a motor is in a no-load operation, and the effective turn ratio of the primary winding and the secondary winding is obtained. Rated voltage is applied to the motor to allow the motor to drive a load to run, a start capacitor is disconnected after normal running, the adjustable run capacitor is connected, the voltage of the primary winding, the secondary winding and the adjustable run capacitor at that time are detected, the ovality information of a gap magnetic field is obtained, the capacitance value of the adjustable run capacitor is changed according to the information, the vibration noise in common single-phase capacitor run motor load running can be effectively inhibited, the adjustable run capacitor can be changed according to different loads dragged by the motor, and the vibration noise is small when multiple types of loads are dragged by the motor.

The invention relates to a method for optimizing the current waveform of a multi-phase permanent magnet synchronous motor, comprising the following steps: A, current reference value coordinate transformation; B, current multi-proportional resonance adjustment; C, coupling compensation; the control method is based on multi-phase permanent Magnetic synchronous motor vector control, the current reference value of the multi-synchronous rotating coordinate system is transformed into the current reference value of each phase in the multi-phase static coordinate system through multi-phase coordinate transformation, and the current feedback value of each phase of the motor is respectively improved by multiple superposition proportional resonance adjustment , and the method of resonance separation is introduced, and the decoupling of feedforward compensation is adopted to realize the static error-free tracking of the fundamental wave and available sub-harmonics with high dynamic performance and the suppression of harmful sub-harmonics. This method can suppress the negative effects of motor loss, torque ripple and vibration noise caused by harmful harmonic currents of multi-phase motors, and enable the positive effects of available harmonic currents to be explored, give full play to the advantages of multi-phase motors, and improve system performance .

This invention provides a seatbelt retractor capable of effectively suppressing occurrence of a vibration and a noise, a base frame (12) is composed of a first frame (16) for rotatably supporting a spool, and a second frame (17) to be attached to a motor vehicle body. The first frame (16) is composed of a pair of flat plate-shaped first and second supporting members (18 and 19), and spacing members (20, 21, 22, and 23) that couple the pair of the first and second supporting members (18 and 19). Further, the degree of the parallelization of the pair of the first and second supporting members (18 and 19) is obtained with high accuracy by the spacing member. Accordingly, an assembling accuracy for a spool can be improved and, thereby, a vibration and a noise caused by a rotation of the spool can be suppressed.

The invention discloses an auxiliary groove structure for suppressing vibration noise of a vehicle permanent magnet synchronous motor. The auxiliary groove structure comprises a groove body, a bufferassembly, a first noise reduction assembly and a second noise reduction assembly, the lower surface of the groove body is fixedly connected with a support, the right end of the outer surface of the groove body is fixedly connected with a first flange, and the left side face in the groove body is fixedly connected with a buffer pad; a second flange is arranged at the front end of the outer surfaceof an end cover, the second flange is fixedly connected with the first flange through a bolt, a mounting hole is formed in the middle of the end cover, and a cooling fan is mounted in the mounting hole; the buffer assembly is fixedly connected to the inner bottom surface of the groove body, and the upper surface of the buffer component is fixedly connected with a motor, the auxiliary groove structure for suppressing the vibration noise of the permanent magnet synchronous motor for the vehicle has the advantages that the vibration of the motor is reduced, the noise reduction is performed through multiple noise reduction measures, the effect is obvious, in addition, the heat on the surface of the motor can be fast transferred out, the heat dissipation efficiency is improved, the aging of internal elements is delayed, and the service life is prolonged.

The invention provides an integrated washing and drying machine with a drying unit with excellent installation performance and a good universality. The integrated washing and drying machine comprisesa machine body, a cylinder body and the drying unit, wherein the cylinder body is arranged in the machine body, and the drying unit is arranged in the machine body and communicated with the cylinder body. The integrated washing and drying machine is characterized in that the drying unit comprises a drying main assembly, an air suction connector assembly connected to the drying main assembly and anair supply connector assembly connected to the drying main assembly.

The invention provides a vibration noise smoothing method and system for attitude time series data. The method comprises the following steps of dividing original attitude time sequence data accordingto a preset time window to form the multiple segments of attitude time sub-sequence data, conducting vibration noise smoothing processing on each segment of attitude time sub-sequence data at the sametime. The processing efficiency can be improved, high real-time performance is achieved, the vibration noise in the attitude time sub-sequence data can be restrained, and smooth transition of continuous same-working-condition and different-attitude data is supported.