36results about How to "Eliminate resonance phenomenon" patented technology

The invention relates to a resonance sound-generating device through an electromagnetic driving manner. A bearing piece (2) is arranged in an outer casing (1); a permanent magnet (3) is arranged in the bearing piece (2); a voice coil suspension (8) is arranged at the outer periphery of the permanent magnet (3); and a drive voice coil (7) is arranged on the voice coil suspension (8). The invention is characterized in that a vibration end cover (6) is connected with one end of the outer casing (1), and the voice coil suspension (8) is fixedly connected with the vibration end cover (6), so as to enable the vibration generated by the voice coil suspension (8) to be transferred to the vibration end cover (6); and a first elastomer(7), a second elastomer (8), and a third elastomer (9) are arranged in the casing. After the structure is adopted, the drive voice coil is utilized to be input with sound signals, so as to enable the voice coil suspension in the magnetic field of the permanent magnet to generate axial vibration, thereby transferring electric signals into the mechanical vibration; and the vibration is transferred to a flat plate through the vibration end cover, so as to drive the flat plate to be in resonant and generate the sound. Furthermore, the invention has the advantages of simple structure, small volume, wide vocal range, and convenient manufacture and assembly.

The invention belongs to the technical field of machining, particularly relates to a combined machining tool for molded surfaces of deep cavities among drum webs and a machining method of the combined machining tool. By the combined machining tool, the technical problems of vibration, tool collision and poor surface quality during machining of the molded surfaces of the deep cavities among the drum webs of aero-engines are solved. The combined machining tool comprises a middle plate-shaped tool, an upper plate-shaped tool and a lower plate-shaped tool. The machining method includes the following steps: step 1, fixedly connecting a transfer tool with a numerically-controlled vertical turning tool clamp; step 2, machining middle molded surfaces of the deep cavities among the drum webs; step 3, machining upper molded surfaces and upper arc-shaped molded surfaces of the deep cavities among the drum webs; step 4, machining lower molded surfaces and lower arc-shaped molded surfaces of the deep cavities among the drum webs to complete machining of primary inner cavities; step 5, circularly performing the step 2 to the step 4 to sequentially complete machining of each-level inner cavities.

The present disclosure relates to an apparatus and a method of reducing vibrations in a washing machine, and particularly, to an apparatus and a method of reducing vibrations in a washing machine that may predict a resonance frequency (or vibration generation region) before operating or driving a motor during a washing process to prevent a resonance phenomenon, thereby reducing noise and vibrations in the washing machine. To this end, the apparatus may include a motor configured to transmit rotational force; a motor driving unit configured to output a motor driving signal controlling an operation of the motor; and a filter configured to remove or reject a frequency or band causing a resonance phenomenon of the washing machine and allow another frequency or band to pass through in the motor driving signal output.

The invention provides a driven plate of a clutch and the clutch. The driven plate of the clutch comprises a plate hub, a driven plate body and damping springs, wherein the plate hub and the driven plate body are coaxially arranged. The plate hub comprises a hub core and a plate hub flange coaxially arranged outside the hub core. The driven plate body is provided with a plurality of first holes which are circumferentially distributed. The plate hub flange is provided with a plurality of second holes which are circumferentially distributed. The first holes and the second holes are axially opposite. The damping springs are arranged in the first holes and the second holes and have pre-tightening force. In the elastic deformation direction, the first end of the first type of damping springs abut against the side walls of the first holes, the second end of the first type of damping springs abut against the side walls of the second holes, the first end of the second type of damping springs abut against the side walls of the second holes, and the second end of the second type of damping springs abut against the side walls of the first holes. In the circumferential direction, the force borne by the driven plate body from the first type of damping forces and the force borne by the driven plate body from the second type damping forces are identical in magnitude and opposite in direction.The driven plate of the clutch is free of idle travel, and the resonance phenomenon caused by the idle travel can be eliminated.

The invention relates to the field of vibration control, in particular to a frequency extension vibration absorber based on an intelligent stiffness element and a control method thereof. Including the vibration absorber body and the control system, the vibration absorber body includes a high magnetic permeability mounting seat, a magnetorheological elastomer and a high magnetic permeability vibration absorbing block that are sequentially fitted from the inside to the outside. The central column of the control system, one end of the central column is connected to the inner circumference of the high magnetic permeability mounting seat through a plurality of ribs uniformly distributed radially along the central column, and an excitation coil is wound on any rib; the control system includes Acceleration sensor, controller and controllable DC power supply. The invention has fast response speed, wide vibration absorption spectrum and effectively avoids new resonance phenomenon of the controlled system due to the introduction of the vibration absorber.

A constant velocity drive shaft of an automobile, including a left half shaft and a right half shaft, wherein the left end of the left half shaft is assembled with the left wheel through the left half shaft fixed joint, and the right end of the left half shaft is connected with the middle differential of the power transmission device through the left half shaft moving joint The left half shaft gear of the transmission is assembled, the left end of the right half shaft is assembled with the right side shaft gear of the differential in the power transmission device through the right half shaft movable joint, and the right end of the right half shaft is connected with the right wheel through the right half shaft fixed joint. Assembly, the right half shaft is a hollow shaft tube structure, the left half shaft is a solid rod shaft structure, the length of the right half shaft hollow shaft tube is X, the length of the left half shaft solid rod shaft is Y, X>Y, the right half shaft The shaft torsional stiffness is K right, the left half shaft torsional stiffness is K left, and K right = K left. The invention not only solves the deviation problem caused by the inconsistency of the torsion angles of the left and right axle shafts when the whole vehicle is running under dynamic load during acceleration, but also eliminates the resonance phenomenon caused by the different speed conditions of the engine, and improves the NVH performance and economic performance of the vehicle.

The invention discloses a phase-sectioning dimming control circuit for an LED lamp and a dimming method of the phase-sectioning dimming control circuit. A logic circuit in the circuit is used for performing multiplication on error amplification signals of input voltages and output currents collected after rectification, phase sectioning is performed on collected rectification voltage signals after phase sectioning is performed on the input voltages, obtained phase-sectioning signals are used for controlling breakover time of a field-effect tube after multiplication is performed on the rectification voltage signals and the output signals of an error amplifier, and the larger the phase sectioning angle is, the smaller the energy transmitted by a transformer is. When a load is constant-voltage characteristic load, output voltages are reduced in the phase sectioning process; when the load is a constant-current characteristic load, the output currents are reduced in the phase sectioning process. According to the phase-sectioning dimming control circuit and the dimming method, on the basis of constant-voltage and constant-current control over power output, the phase-sectioning dimming function is achieved through dummy loads, signal collecting, processing and other means, and therefore the whole circuit system achieves the purpose of compatibility of constant-voltage phase-sectioning dimming and constant-current phase-sectioning dimming.

The invention discloses a low-torque linkage double-open fire hydrant which comprises a hydrant seat. A hydrant body is arranged on the hydrant seat; a hydrant cover is sealed at the end of the hydrant body; a valve seat is arranged between the hydrant seat and the hydrant body; a valve cavity is formed in the valve seat; a valve core is arranged in the valve cavity; an operating rod penetrates through the hydrant body and the hydrant cover; the valve core comprises a valve plate; a pressure-relief hole is formed in the valve plate and is provided with a pressure-relief valve for blocking the pressure-relief hole; the operating rod is connected with the pressure-relief valve; a linkage limiting device is arranged between the operating rod and the valve plate; when the fire hydrant is opened, an operating screw rod drives the valve plate to move downwards, and because the area of the pressure-relief valve is smaller than that of the valve plate, the pressure-relief valve can be rapidly opened through small opening torque, and thus the pressure in a cavity of the fire hydrant is reduced; and moreover, when the fire hydrant is closed, the valve plate with large area moves upwards, and then the pressure-relief valve is closed, so that the pressure-relief valve is opened or closed in a labor-saving mode, the resonance phenomenon of the internal parts is eliminated, noises are eliminated, and the low-torque linkage double-open fire hydrant is convenient and reliable to use.

The invention relates to a rack capable of eliminating the resonance of a multi-rotor aircraft. The rack comprises a central plate, wherein two carbon fiber tubes which are horizontally placed and are vertical to each other are arranged on the central plate, and an undercarriage placed horizontally is arranged below the central plate; two adjacent sides of the two carbon fiber tubes are connected by a connecting rod; four brackets distributed in a circumference and in an arc shape are arranged between the central plate and the undercarriage; and reinforcing rods are arranged between two ends of each carbon fiber tube and the undercarriage. According to the rack, two adjacent sides of the two carbon fiber tubes are fixed by the connecting rod, so that the resonance phenomenon generated by a motor is eliminated, and thus the service lives of the aircraft and a flight control system are prolonged.

The invention discloses a suspension device of an automotive exhaust system capable of adjusting the angle of a lifting lug, comprising the lifting lug, a connection pin I, a connection pin II, a support I provided with a chute and a support II provided with a chute, wherein, the connection pin I and the connection pin II are connected with the support I and the support II through the chutes, and are connected with the lifting lug. The suspension device of the invention can conveniently adjust the installation angle of the lifting lug relative to the automotive body, can adjust the lifting lug at any time according to actual conditions, and eliminates covibration to the greatest extent, thus leading the transmission amount of the vibration of the exhaust system to the automobile body to reach the lowest value, improving comfort of a control cabin, reducing noise pollution and prolonging the service life of the suspension device; and meanwhile, when a vibration test of the exhaust system is performed, multiple different suspension devices need not to be manufactured, thus large scale adjustment of the lifting lug angle is realized, thereby realizing tests of lifting lugs at different installation angles, which has an important significance in improving work efficiency, shortening development cycle and lowering development cost in the development process of automobiles.

The invention relates to the field of ship machinery manufacturing, and discloses an intelligent anti-rolling device for ships. Through the setting of a drive plate, etc., the counterweight box is pulled into the placement groove on the base to complete the low-height limit and prevent the ship from being static or driving. When there is no need for anti-rolling, the position of the counterweight box is too high to cause greater resistance, thereby increasing energy consumption or affecting the state of the ship. By driving the motor to run further, the vibration frequency of the counterweight box and multiple sub-springs can be quickly changed to eliminate resonance. phenomenon, improve the safety performance of the ship, change the overall quality of the counterweight through electromagnets and other settings, and match the load of the cargo ship to ensure sufficient anti-rolling force of the hull and avoid large swaying phenomena of the hull. Through arc chamfering and other settings, The counterweight is mechanically limited, and there is no need for the electromagnet to keep the energized state for a long time, which saves energy and improves the practicability of the anti-rolling device.

A clutch driven disc and a clutch, wherein the clutch driven disc includes: a hub arranged coaxially, a driven disc body, the hub includes a hub core, and a hub flange coaxially arranged outside the hub core ; The driven disc body has several first holes distributed circumferentially, the hub flange has several second holes distributed circumferentially, the first holes are axially opposite to the second holes; vibration damping The spring is arranged in the first hole and the second hole and has a pre-tightening force; along the elastic deformation direction, the first end of the first type damping spring is against the side wall of the first hole, and the second end is in contact with the side wall of the first hole. The side wall of the second hole is against, the first end of the second type of damping spring is against the side wall of the second hole, and the second end is against the side wall of the first hole; along the circumferential direction, the driven disc body The force received by the first type of damping spring is equal in size and opposite in direction to the force received by the second type of damping spring. The clutch driven disc of the present invention has no idle stroke, and can eliminate the resonance phenomenon caused by the idle stroke.