282 results about "Harmonic vibration" patented technology

A rotary cutting tool that includes an elongated tool body, rotatable along a longitudinal axis of rotation is disclosed. It has a fluted cutting end on one end and a shank end on the opposite end of the tool body. The fluted cutting end includes a nose, a periphery and an end surface that extends from the nose to the periphery. A plurality of axial flutes extends from the end surface to the fluted cutting end and combines with a plurality of cutting edges. The cutting edges are unequally spaced along the circumference of the end surface lying in a plane perpendicular to the longitudinal axis of rotation. In addition, all cutting edges are of a different helix from one another and the cutting edge geometries vary from one another to create a different sound pattern. This reduces resonant harmonic vibrations.

Harmonic capacitive micromachined ultrasonic transducer (“cMUT”) devices and fabrication methods are provided. In a preferred embodiment, a harmonic cMUT device generally comprises a membrane having a non-uniform mass distribution. A mass load positioned along the membrane can be utilized to alter the mass distribution of the membrane. The mass load can be a part of the membrane and formed of the same material or a different material as the membrane. The mass load can be positioned to correspond with a vibration mode of the membrane, and also to adjust or shift a vibration mode of the membrane. The mass load can also be positioned at predetermined locations along the membrane to control the harmonic vibrations of the membrane. A cMUT can also comprise a cavity defined by the membrane, a first electrode proximate the membrane, and a second electrode proximate a substrate. Other embodiments are also claimed and described.

The invention relates to a hydro-oscillator for well drilling. The hydro-oscillator consists of a hydraulic driving assembly, a fixed valve assembly, a bottom assembly and a vibrating pipe nipple, wherein the vibrating pipe nipple is connected with the hydraulic driving assembly; a rotor is connected with a vibrating valve; the fixed valve assembly is arranged on the bottom assembly; and a power shell is connected with the bottom assembly. A drilling fluid is used for driving the rotor to rotate, and the rotor is used for driving the vibrating valve to vibrate, so that flow holes of the vibrating valve and a fixed valve are staggered with each other, and simple harmonic pressure waves are modulated and are upwardly transmitted to a disc spring for driving the vibrating shell to perform continuous simple harmonic vibration in the axial direction, so that the friction resistance between a drilling column and a well wall is improved effectively, and the drilling speed is increased; and meanwhile, pressure waves are downwardly transmitted to drill bit jet flow, so that periodic change of rock breaking pressure is facilitated, and rocks are crushed effectively. The hydro-oscillator has the characteristics of simple structure, convenience for operating, safety, reliability, low pressure drop, high adaptability, no influence on the drilling tool structure and the like, and plays an important role in increasing the drilling speed and reducing cost.

A noise suppression method of a wave filter used to eliminate standing wave signal interferences in the acoustic wave filter consisted by a plurality of film bulk acoustic resonators (FBARs). The method is to provide a plurality of scatterers in the structured consisted by the FBARs, thereby creating an band-gap structure due to the material characteristics difference, which consequently generates a destructive interfering effect to the transverse higher harmonics vibration within a specific operating frequency range, and ultimately decreases or even eliminates any parasitic effects. Therefore, within the operation frequency range of this band-gap structure, abnormal signals created by any transverse wave modes cannot exist. In addition, an acoustic shield can be provided by phononic crystal structures between different FBARs, thus acoustic shielding any mutual interference within the operation frequency range.

Multiple criteria are monitored and controlled to enhance the success of direct-metal deposition, including greater control over factors such as deposit layer height / thickness, sub-harmonic vibration, contour path shape, powder mass flow, and deposition speed, and stress accumulation. Sensors are used to monitor some or all of the following parameters during the deposition process: deposit height, width, temperature, and residual stress. A predetermined limit with respect to the yield strength of the material is preferably set. If the stress exceeds that limit sensors will automatically introduce one or more remedial measures, the priority of which is established using a look-up table generated in accordance with prior experimental knowledge. To control temperature induced distortion and stress, an infrared temperature detector may be used in conjunction with a controller to reduce temperature, increase speed and decreased power for purpose of stress management.

Harmonic capacitive micromachined ultrasonic transducer (“cMUT”) devices and fabrication methods are provided. In a preferred embodiment, a harmonic cMUT device generally comprises a membrane having a non-uniform mass distribution. A mass load positioned along the membrane can be utilized to alter the mass distribution of the membrane. The mass load can be a part of the membrane and formed of the same material or a different material as the membrane. The mass load can be positioned to correspond with a vibration mode of the membrane, and also to adjust or shift a vibration mode of the membrane. The mass load can also be positioned at predetermined locations along the membrane to control the harmonic vibrations of the membrane. A cMUT can also comprise a cavity defined by the membrane, a first electrode proximate the membrane, and a second electrode proximate a substrate. Other embodiments are also claimed and described.

The invention discloses a resonant converter comprising a transformer, a square wave generator, a resonant circuit, an output rectifying circuit, and an output filtering circuit, wherein the output rectifying circuit is connected between the secondary line winding of the transformer and the output filtering circuit; the input terminal of the square wave generator is connected with DC power supply; the square wave generator is used to convert the input DC voltage into square wave AC voltage and export; the resonant circuit comprises a first inductor, a resonant capacitor, and a second inductor; the resonant capacitor and the first inductor are series-connected into a resonant branch; the second inductor and the first line winding of the transformer are parallel-connected into a parallel branch; one end of the resonant branch is connected with one end of the parallel branch; the other ends of the resonant branch and the parallel branch are respectively connected with the two output terminals of the square wave generator. The square wave AC voltage from the square wave generator has fixed frequency and adjustable duty ratio, which can prevent working frequency of the converter from being in a wide range, optimizing the design of the output filtering circuit.

A rotary cutting tool such as a helical end mill, having pockets arranged to overcome harmonic vibrations. The tool has at least two and in one embodiment all three of three spacing irregularities. In the first irregularity, columns of pockets, typically associated with flutes, are staggered circumferentially out of even spacing. In a preferred embodiment having three flutes, the flutes are mostly not centered on one hundred twenty degree intervals. In the second irregularity, at least some pockets are arranged at different radial rake angles. In the third irregularity, at least some pockets are arranged at different axial rake angles.

In an electric motor provided with a bearing mechanism utilizing fluid dynamic pressure, it is an object of the invention to restrain synergy superimposition and synergy superimposition resonance of vibration caused by deterioration of roundness of the sleeve and harmonic vibration caused by number of poles or number of phase. In a bearing mechanism which is provided in a motor and which utilizes fluid dynamic pressure of lubricant oil, five straight grooves substantially parallel to the center axis J1 are formed in an outer surface of a sleeve at substantially equal distances from one another in the circumferential direction. The grooves and an inner surface of a sleeve housing form flow paths for circulating the lubricant oil. In the motor, the number of grooves of the sleeve is a relative prime with respect to the number of phase (three phase) of drive current of the motor and the number of poles (eight poles) of the field magnet. With this, it is possible to suppress the synergy superimposition and the synergy superimposition resonance of vibration caused by deterioration of the roundness of sleeve and vibration caused by number of poles of the motor or the number of phase of the drive current.

An apparatus for cutting materials and more specifically an improved saw blade includes a plurality of variable teeth thereon. The variable tooth saw blade cuts faster and smoother while reducing harmonic vibrations. Specifically, the teeth on the saw blade are grouped into sections with differing circumferential widths and differing spacing between the sections.

A modular integrated rail system for a firearm includes a dampening device for absorbing shock waves and dissipating harmonic vibration generated by a firearm. The modular integrated rail system includes an upper hand guard, a clamping assembly configured to releasably clamp the hand guard to the firearm, and a dampening structure disposed within a cavity formed in the hand guard. The cavity has opposing fixed end walls, and the dampening structure is captivated between the opposing fixed end walls of the cavity.

A mounting assembly for attaching an accessory to a dovetail rail interface on a firearm includes a body having a lower portion and an upper portion. The lower portion is configured to engage the dovetail rail interface and the upper portion is configured to receive and retain an accessory such as a scope or aiming device. A spring dampening structure resides within the body of the assembly wherein dampening structure is configured to dampen shock waves and harmonic vibration transferred into the body from operation of the firearm. A clamping assembly is configured to releasably clamp the body to the dovetail rail interface.

An alternating current electrified railway traction network impedance frequency characteristic testing device is composed of a step-down transformer TP, a harmonic source HS, a monitoring device MC, a voltage transducer TV and a current transducer TA. The monitoring device MC controls that the harmonic source HS sends harmonic current and injects a primary side winding of the step-down transformer TP into a traction network. The voltage transducer TV and the current transducer TA respectively detects harmonic voltage between a contact network T and a steel rail G and the harmonic current injected into the traction network, and the monitoring device MC receives output signals of the voltage transducer TV and the current transducer TA and finishes harmonic impedance calculation. Under the situation that the contact network is electrified, an impedance frequency characteristic of the traction network can be obtained by adjusting the frequency and amplitude of the current sent by the harmonic source, and further the harmonic frequency is obtained. The alternating current electrified railway traction network impedance frequency characteristic testing device can be used for newly-constructed electrified railway joint debugging integration test and can be also used for providing technical support for solving the harmonic vibration problem and guaranteeing power supply safety of existing lines.

The invention discloses a process for processing a carburizing and quenching gear with a welding structure. The process is performed according to the following steps: the inner circle, the outer circle and the two end surfaces of a gear ring are processed, a hub and a radial plate are processed, and the margins are kept on the inner hole and the two end surfaces of the hub; the tooth form of the gear ring is coarsely processed, and the margins are kept; the gear ring is carburized, quenched, oil-cooled and low-temperature tempered; the radial plate and the hub are group-welded, and the gear ring and the radial plate are group-welded on a rotary work table of an automatic welding machine, the gear ring is pre-heated before welding, in the turning process when the gear ring is pre-heated and welded, the tooth part is cooled by cooling fluid through a cooling device, so that the temperature of the tooth part is below 200 DEG C; the ultrasonic crack detection of the welding seam is preformed; the stress is eliminated by the spectral harmonic vibration; and the precision machined step is performed. The process can ensure the hardness and the performance of the tooth surface of the gear as well as the quality of the welding seam after the gear ring is carburized and quenched, thereby solving the problem of the crack of the welding seam; moreover, by adopting the vibration stress eliminating process to eliminate the welding stress, the environment is protected, and the energy consumption is greatly lowered.

A rotary cutting tool such as a helical end mill, having pockets arranged to overcome harmonic vibrations. The tool has at least two and in one embodiment all three of three spacing irregularities. In the first irregularity, columns of pockets, typically associated with flutes, are staggered circumferentially out of even spacing. In a preferred embodiment having three flutes, the flutes are mostly not centered on one hundred twenty degree intervals. In the second irregularity, at least some pockets are arranged at different radial rake angles. In the third irregularity, at least some pockets are arranged at different axial rake angles.

A noise suppression method of a wave filter used to eliminate standing wave signal interferences in the acoustic wave filter consisted by a plurality of film bulk acoustic resonators (FBARs). The method is to provide a plurality of scatterers in the structured consisted by the FBARs, thereby creating an band-gap structure due to the material characteristics difference, which consequently generates a destructive interfering effect to the transverse higher harmonics vibration within a specific operating frequency range, and ultimately decreases or even eliminates any parasitic effects. Therefore, within the operation frequency range of this band-gap structure, abnormal signals created by any transverse wave modes cannot exist. In addition, an acoustic shield can be provided by phononic crystal structures between different FBARs, thus acoustic shielding any mutual interference within the operation frequency range.

The invention discloses a harmonic modal analysis method for an offshore wind farm. The method comprises the steps of 1) building a system harmonic model according to an offshore wind farm system, namely a connection relationship between each component and a cable; 2) establishing a network admittance matrix of the system according to the system harmonic model, solving a modal impedance frequency spectrum of the system by utilizing a modal method, calculating a participation factor of each node, and determining a real occurrence position of harmonic vibration; 3) assessing the sensitivity of electric parameters of components of the system; and 4) assessing the sensitivity of design parameters of the system. According to the method, an equivalent model is built according to the parameter of each component of the wind farm, the harmonic performance of the system under different topological parameters, cable parameters, transformer parameters and other parameters is studied by applying the modal analysis method, and the topological design and component model selection of the wind farm can be optimized.

A spring, which may be either a coil spring or a leaf spring, provides an adjustable stabilization force to the barrel of a rifle to tune out harmonic vibrations resulting from firing a particular bullet from the weapon. This tuning enables the scatter pattern for any bullet fired from any rifle to be significantly tightened from the resultant improved accuracy of the weapon.

The invention discloses an offshore-type wave energy sea water desalination and power generation combined device. The device comprises a support platform, a floating body, a pretreatment tank, a sea water piston pump, a reverse osmosis membrane component, a thrust cylinder, a vibrating pipe-type linear generator, a fresh water tank, a fresh water piston pump and a hydroelectric generating set. Wave energy is converted into sea water pressure energy by the aid of the sea water piston pump, high-pressure sea water passes the reverse osmosis membrane component to obtain fresh water, discharged concentrated sea water drives a thrust rod and a thrust disc of the thrust cylinder to move, the thrust disc is in contact with a slider of a permanent magnet mounted in the linear generator and pushes the slider to move, and the slider in movement generates and maintains high-speed simple harmonic vibration under combined action of two groups of vibrating springs of the linear generator. The wave energy is converted into pressure energy of the obtained fresh water by the aid of the fresh water piston pump, and the high-pressure fresh water is delivered landwards automatically and drives the hydroelectric generating set to act and generate power. The offshore-type wave energy sea water desalination and power generation combined device can not only output high-frequency high-power current but also deliver fresh water landwards automatically, has the advantages of high energy utilization rate and lower power generation cost and fresh water cost, and is particularly suitable for low-cost mass production.

The invention discloses a standard-static method for measuring the piezoelectric coefficient of d15 of piezoelectric materials. The standard-static method comprises the following steps: (a) based on the beam theory of Timoshenko, by means of a piezoelectric laminated cantilever beam of an operating mode of d15, putting forward an experimental method principle model which can measure the piezoelectric coefficient of the d15 of the piezoelectric materials; (b), conducting horizontal polarization on a piezoelectricity block body, manufacturing a coplanar electrode structural piezoelectricity laminated cantilever beam, and enabling the cantilever to be in a d15 shearing operating mode by means of series circuit connection; (c) setting up an excitation vibration device, enabling the cantilever to obtain the excitation frequency which is far less than the resonant frequency and voltage, and measuring the harmonic vibration accelerated speed and the output electric charge under the standard-static condition of the cantilever beam; (d) substituting the structural size, the material parameter and the output electric charge of the cantilever bean into the principle model so that the piezoelectricity coefficient d15 of the piezoelectric materials can be estimated. The standard-static method for measuring the piezoelectric coefficient d15 of the piezoelectric materials has the advantages of being capable of measuring the piezoelectric coefficient d15 of the piezoelectric materials, simple in technology, easy to operate, capable of measuring the piezoelectric coefficient d15 of piezoelectric ceramic, piezoelectric crystal and piezoelectric film materials, and wide in application range.

The invention discloses a high-speed bogie dynamic design method based on an anti-snake movement frequency band energy absorption mechanism. A high-speed train is viewed as a closed-loop system, and advanced correction is conducted on an instable snake movement oscillating phenomenon of a bogie by means of an adaptive control mode. According to an anti-snake movement matching principle, an optimal distribution theoretical scheme of the bogie is determined. A novel anti-snake movement damper using a double-flow control principle is selected and used, a technical implementation mode of the novel anti-snake movement damper is worked out by using an anti-snake movement series stiffness judging principle, anti-snake movement is restrained softly, or an expansion bag is added into an auxiliary cavity. The dynamic performance assessment should have three stable features of a high-speed bogie. In order to lower lateral coupling strength, a train body model state form is reorganized to analyze aluminum alloy train body lateral coupled oscillation inherent features, the lateral stiffness of a suspension point is determined according to a harmonic vibration reduction mechanism, according to a structural damping constraint effect, the damping optimum value of rubber proportions is selected, a bolt pre-tightening or deadweight wedge-caulking rubber suspension mode is used, and therefore desired stable robust performance of bogie optimal match is achieved.

The invention discloses a frequency-raising type vibration energy collecting system and a collecting method. The environmental vibration frequency is sensed through a low-frequency harmonic vibration structure, and the low-frequency harmonic vibration structure is in contact and collision with a high-frequency harmonic vibration structure to cause the high-frequency harmonic vibration structure to realize self-excited vibration, so that the purpose of raising the frequency is achieved. Through the high-frequency vibration of the high-frequency harmonic vibration structure, a piezoelectric material layer on a high-frequency vibration beam is extended and compressed in a periodicity manner, the high-efficiency conversion from vibration energy to electric energy is realized, and high-density output and low operating frequency are considered together. The vibration beam with the low-frequency harmonic vibration structure has the advantages of lower structural stiffness and higher harmonic vibration quality, the resonance vibration frequency can be reduced to below 50 Hz, the response to the environmental vibration frequency is sensitive, and the application range is wider.

The invention relates to a high-precision aspheric surface ultrasonic polishing method for small-aperture brittle high-hardness materials, and discloses a non-contact type ultrasonic surface shape correcting and polishing method and a device thereof. A bristle hard alloy material is polished by the aid of propagation characteristics of ultrasonic simple harmonic vibration, which is generated by acircular oscillator, in liquid, and a stable material removing function in Gaussian distribution can be realized. After a polishing path covering an integral processed surface is set, dwell time of atool head at each of points on the polishing path is determined according to the obtained material removing function and residual errors of the processed surface, and a processing program is scheduled and inputted into a numerical-control machine tool to realize correcting and polishing processing. Accurate control of material removal amount of different areas of the surface by means of combiningthe numerical control technology, surface shape correcting and polishing of various optical surfaces such as planes, spherical surfaces, aspheric surfaces and the like can be realized, and optical surfaces with high surface shape precision can be obtained.

The invention discloses a magnetic suspension rotor harmonic vibration suppression method based on a frequency-domain self-adaption LMS (least mean square) algorithm. Aiming at a four-freedom-degree active-passive magnetic suspension control moment top, dynamics modeling of a magnetic suspension rotor is performed on the condition of considering rotor mass unbalance and sensor harmonic waves, the harmonic vibration suppression method based on the frequency-domain self-adaption LMS algorithm is designed to suppress frequency doubling vibration of a rotor system, and a wave trap is used for suppressing synchronous vibration. The magnetic suspension rotor harmonic vibration suppression method has the advantages that the method can suppress harmonic components in magnetic bearing coil currents to further suppress harmonic components in rotor displacement and is applicable to active control of magnetic suspension rotor system harmonic vibration with the mass unbalance and the sensor harmonic waves.

The invention provides a swing type wave power generation device which is composed of a mechanical part and a circuit part. The mechanical part is composed of a floater, a rack, a motor gear box assembly, a suspension system, a pendulum rod and a pendulum bob. The rack is fixed inside the floater, a stator of the motor gear box assembly is fixedly connected with the rack, an output shaft of the motor gear box assembly is fixedly connected with one end of the pendulum rod through a coupler and the suspension system, the other end of pendulum rod is fixedly connected with pendulum rod, and the pendulum rod is capable of driving the pendulum rod to drive the output shaft of the motor gear box assembly to rotate. The circuit part is composed of a storage cell and a power storage circuit. The storage cell and the power storage circuit are arranged inside the floater. A motor outputs power, commutating, voltage-stabilizing and voltage-rising are conducted on the power through the power storage circuit, and the power is stored into the storage cell. The swing type wave power generation device utilizes similarly-regular simple harmonic vibration of waves to force the pendulum rod to swing and drag a generator to rotate to produce current. The swing type wave power generation device is simple in structure, and high in energy conversion utilization rate.

The invention discloses a device and a method for detecting water content of fresh tobacco leaves. The device comprises a detection box, a first electrode plate, a second electrode plate, a frequency measuring device and a computer, wherein the detection box is internally provided with an SAW (Surface Acoustic Wave) harmonic vibration detector and a stabilized voltage supply; the stabilized voltage supply is electrically connected with a power supply end of the SAW harmonic vibration detector; two detection ends of the SAW harmonic vibration detector are electrically connected with the first electrode plate and the second electrode plate respectively; the output end of the SAW harmonic vibration detector is electrically connected with the input end of the frequency measuring device; the output end of the frequency measuring device is electrically connected with the computer. With the method, the fresh tobacco leaves to be detected are detected through the SAW harmonic vibration detector, a characteristic value M is obtained after nonlinear stochastic resonance processing of frequency of output signal of the SAW harmonic vibration detector, and the characteristic value is substituted into a forecast formula of proportion of the water content to calculate and obtain the water content of the fresh tobacco leaves. According to the device and the method, the water content of the fresh tobacco leaves can be quickly and accurately detected in a lossless manner.

The invention discloses a resonant tuning fork liquid density sensor with piezoelectric actuation and piezoelectric detection, comprising a tuning fork body, a clamped body, a piezoelectric actuator, a piezoelectric vibration pickup, and a temperature sensor, wherein, the piezoelectric actuator and the piezoelectric vibration pickup are arranged on the clamped body, the generated alternating force is transmitted to the tuning fork body by the piezoelectric actuator to let the tuning fork body produce simple harmonic vibration with intrinsic frequency itself; when immersing the tuning fork body in a liquid under test, the additional mass of the tuning fork body changes so as to let the vibration frequency of the tuning fork body change; by picking up the vibration signal with the piezoelectric vibration pickup, the detection of the vibration frequency of the tuning fork body is realized; because the vibration frequency of the tuning fork body is a monotone function of the liquid density, thus the real-time on-line detection of the liquid density is realized; and the temperature sensor is arranged on the clamped body for real-time detection of the temperature of the liquid under test, and is used for compensating the variation of the elastic modulus of the tuning fork body. According to the invention, the high precision on-line detection of densities of various liquids at different temperature can be realized.

Described is a method for examining a surface of a sample using an atomic force scanning microscope (AFM) comprising a cantilever with a longitudinal extension along which a measuring tip is disposed, which is selectively arranged relative to said sample surface by a driver means and whose spatial position is detected using a sensor unit, and said microscope is provided with at least one ultrasound generator, which initiates vibration excitation at a given excitation frequency between said sample surface and said cantilever, the measuring tip of which is brought into contact with said sample surface in such a manner that said measuring tip is excited to vibrations which are oriented lateral to said sample surface and perpendicular to said longitudinal extension of said cantilever and that the torsional vibrations induced in said cantilever are detected and analyzed by means of an evaluation unit. The invention is distinguished in that the vibration excitation occurs in such a manner that the oscillations executed by the measuring tip have higher harmonic vibration parts relative to the excitation frequency, that vibration excitation is conducted at excitation amplitudes which lead inside the cantilever to torsional amplitudes, the maximum values of which form a largely constant plateau value despite increasing excitation amplitudes and the resonance spectra of which undergo, in the range of the maximum values of the torsional amplitudes, a widening of the resonance spectrum which is determinable by a plateau width, and that used for examining the sample surface are the resonance spectra, preferably the plateau value, the plateau width and / or the gradient of the respective resonance spectra.