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

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 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.