56results about How to "Avoid abnormal vibration" patented technology

The moment of inertia and the eccentric load are measured in rotating a drum at 100 rpm, and the decision critical value is decided according to the moment of inertia and the eccentric load(S31-S42). The motor is controlled to accelerate within the range of 140 to 220 rpm less than the resonance point of about 250 rpm, and the value is measured according to fluctuation of acceleration(S43-S47). The large vibration is decided, and the emergency stop is performed in case of the value from the acceleration fluctuation to be over the critical value(S48). Acceleration is changed by adding uneven load to the bearing in rotating while reducing eccentric load, and the critical value is decided accurately according to the moment of inertia and the eccentric load.

A vehicle brake apparatus capable of preventing abnormal vibration due to thickness variations in a disc rotor includes a motor drive unit configured to control the motor which presses the brake pad against the disc rotor, a brake pressure detection unit for detecting a braking pressure for pressing the brake pad, and a wheel speed sensor for detecting a rotation speed of the disc rotor. If an amount of variation in the detection values detected by the brake pressure detection unit during one rotation of the disc rotor exceeds a variation amount determination threshold value and a detection value variation frequency has a correlation with the rotation speed of the disc rotor and the detection value variation frequency exceeds a variation frequency determination threshold value, the motor drive unit controls the motor in inverted phase to the variation in the detection values.

The invention aims to provide a centrifugal refrigerator having high pressure head specification. The centrifugal refrigerator can avoid surge, and the capacity of the refrigerator can be reduced to the load capacity on the equipment side during low pressure head. The centrifugal refrigerator comprises a measuring unit, an economizer steam valve (7) and a control device (20), wherein the measuring unit is used for measuring the pressure difference between a condenser (4) and an evaporator (5); the economizer steam valve (7) is arranged on a flow path (11) and used for opening and closing the flow path (11), and the flow path (11) is used for communicating an economizer (6) with the middle part of multiple compression stages of a multi-stage centrifugal compressor (TC); the control device (20) controls the opening of a guide vane which is used for adjusting the flow of suction facing the multi-stage centrifugal compressor (TC), and controls the lower limit of opening of the guide vane variably on the basis of the relationship between the preset pressure difference of the condenser (4) and the evaporator (5) and the lower limit of opening of the guide vane according to the pressure difference measured by the measuring unit.

Provided is a technique which can prevent abnormal vibrations from occurring on a resonator and apply, to a cutting edge, vibrations with the magnitude of amplitude thereof adjusted in the direction of width of the edge, thereby cutting an object of interest with high accuracy. The resonator (21) with a grip portion grasped with clamp means (28) is supported by a support means (24), thereby preventing abnormal vibrations from occurring on the resonator (21). The resonator (21) has at least one elongated hole (26b) defined through a side thereof, thus allowing for adjusting the amplitude magnitude of vibrations in the direction of width of the cutting edge (23) on one end of the resonator (21). This enables vibrations with the amplitude of an adjusted magnitude in the direction of width to be applied to the cutting edge (23). Accordingly, the cutting edge (23) which is adequately vibrated can be used to cut the object of interest with high accuracy.

The invention discloses a portable transformer substation noise imaging positioning detection device which comprises an imaging displaying mechanism and a noise detection mechanism which are connected via a coaxial cable, the noise detection mechanism comprises a noise sensor of which a matrix is arranged on a quadratic surface structure and a signal pre-treatment circuit; the imaging display mechanism comprises a display, a processor and a data memory connected with the processor; the processor is provided with a sound intensity mapping processing module for driving and displaying a sound intensity mapping figure to quickly judge a noise resource. According to the position of equipment to be detected in a transformer substation, a cubic data module of a quadratic surface is established, a three-dimensional coordinate system is established on the basis of the cubic data module, and pre-treatment and pre-displaying of a relative noise signal are performed, spurious imaging information is used for noise imaging, and quick fault positioning is achieved by analyzing a color ring band. The portable transformer substation noise imaging positioning detection device effectively improves the efficiency of overhauling and maintaining the transformer substation, is simple, convenient and practical, and has very high promotion and application values.

The invention provides a low-noise deep groove ball bearing. A bearing retainer (6) formed by mutually buckling two parts is distributed in a cavity between a bearing inner ring and a bearing outer ring, the combination position of the bearing retainer (6) among bearing balls (3) uses a tenon and groove combination form, the bearing retainer (6) is in an axial direction between the bearing inner ring (1) and the bearing outer ring (2), two side parts of the spherical cavity form two annular slots (6.2, 6.4), and the openings of the two slots are open to a baring ball raceway and are divergent.

The invention discloses a method for reminding a user to dismantle a package bolt, relating to the technical field of washing machines. The method for reminding the user to dismantle the package boltcomprises the following steps: a reminding module reminds the user to dismantle the package bolt at least one time after the washing time is started. After the washing machine is started certain time,the reminding module reminds the user to dismantle the package bolt. After the user dismantles the package bolt, great noises or abnormal vibrations during a clothes-washing process are avoided. Therefore, normal application of the washing machine is ensured so that damage is avoided.

The invention discloses a fully mechanized coal mining face real-time three-dimensional imaging method and system based on multiple laser radars. The imaging method comprises the steps that the pose of any laser radar in a corresponding hydraulic support coordinate system is acquired, and the laser radar is preset on the corresponding hydraulic support; acquiring original point data of a local fully mechanized coal mining face in the field of view of any laser radar at the current moment; performing local real-time imaging on the local fully mechanized coal mining face through the original point data; and by taking a hydraulic support coordinate system as a reference, converting a result of any local real-time imaging into the hydraulic support coordinate system so as to carry out global real-time imaging. According to the imaging system, laser radars are arranged on a hydraulic support, and sub-processors corresponding to the laser radars, a total processor connected with the sub-processors and software for executing the imaging method are arranged. Local real-time imaging and global real-time imaging of the fully mechanized coal mining face can be achieved, and an original mine structure does not need to be transformed.