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.

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.

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.

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.

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.

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.

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 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 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.