317 results about "Rotor vibration" patented technology

A system and method for determining thermal growth of motor or engine parts to thereupon control the clearance of motor or engine fan blades is disclosed herein. In addition, a system and method for monitoring the health of a turbine engine, its components and sub-components is also described herein. The system(s) and method(s) described herein permit continuous monitoring during the life of the engine for radial clearances and blade and rotor vibration problems, which will assist in correcting and retaining performance for a longer on-wing time in operation. In addition, inconsistent engine-to-engine performance variations due to component tolerances, engine operation characteristics, and operation during extremes in ambient temperatures can be eliminated or significantly minimized when employing the system(s) and method(s) described herein.

The bearing assembly comprises a radial foil bearing and an axial foil bearing, a control bearing preload device for controlling stiffness of the bearing under normal operating conditions, an electromagnetic unloading device for decreasing amplitude of rotor oscillations and an unloading means for increasing the ultimate bearing load without damaging bump foils. The radial foil bearing comprises a bushing 6 providing accommodating bearing misalignment with respect to the journal, an elastic member in the form of an elastic damping unit for increasing damping, which consists of a bump foil 20 and two smooth foils 16 and 22. The bump foils in the bearing have different heights and alternate in the axial direction to decrease wear under start/stop. A top foil 4 of the bearing is weldlessly retained within slots of mounting bars 70 and 80. The axial bearing has the bump foil with ridges circumferentially extended in order for the bearing to work in sealing mode. The top foils of the bearing are provided with circumferential slits in order to decrease thermal stress.

A rotor aircraft has a fuselage with a rotor mounted above by a rotor shaft. An arm is pivotally engaged with a lower portion of the rotor shaft and pivotally engaged with the fuselage, enabling the rotor to move with little restriction vertically and horizontal in all directions relative to the fuselage as the rotor rotates in order to isolate rotor oscillations. An infinitely variable air spring is used to counter vertical and fore and aft loads. Damping in the form of elastomeric materials, piston seal friction, and fluid flow through an orifice may be added as required.

The invention relates to a rotor variable-mass frequency-modulation dynamic vibration absorber of rotating machinery. The vibration absorber is formed by a connection transmission mechanism, a mass regulating mechanism and a control system. A rotating machinery rotor produces vibration in the work. The rotor variable-mass frequency-modulation dynamic vibration absorber is installed at the proper position of the rotor. The connection transmission mechanism installed on the rotor transmits vibration energy produced by the rotor to the mass regulating mechanism; the mass regulating mechanism keeps consistent in frequency with a rotor main system under the adjustment of the control system to cause resonance; an annular mass plate produces a dynamic response and counteracts the dynamic response on the rotor main system, so that the effects of offsetting and suppressing rotor vibration are achieved. The rotor variable-mass frequency-modulation dynamic vibration absorber is unique in structure, high in reliability, stable in performance, low in maintenance frequency, flexible in installing position and good in adaptability; besides, the control system is excellent, and active control is easy to achieve.

The invention discloses a method for adjusting dynamic balance of a rotor of a magnetic suspension vacuum molecular pump, which particularly comprises fist, detecting an actual vibrating signal of a rotor which is obtained by a sensor directly from a rotor of a magnetic bearing, second, collecting rotor speed and phase signal, third, doing an isolating process of direct current composition to the vibrating signal of the rotor which is obtained, fourth, doing a real-time filtering process to the vibrating signal according to the rotor speed, obtaining vibrating signals with the same frequency of the rotor, fifth, finishing corresponding dynamic balance algorism in post period by utilizing a dynamic balancing device or an observation system which is operated in a magnetic suspension vacuum molecular pump, and doing a dynamic balance to the rotor according to the result of the dynamic balance algorism, sixth, repeating the steps untill the rotor achieves a needed dynamic balancing accuracy. The method of the invention has the advantages of high accuracy of a vibrating value which is collected, high dynamic balance accuracy, and balancing behavior of the rotor is completely consistent with the final actual operating behavior, which is beneficial for simplifying dynamic balancing equipment.

Vibration is monitored in a dual rotor engine. A first total vibration of the engine is measured during operation. Relative phase of the two rotors is then clocked, and a second total vibration of the engine is then measured during operation. First and second total unbalances are then resolved at a common response frequency from the measured total vibrations. First and second rotor unbalances are then resolved for the corresponding rotors from the first and second total unbalances. In a further method, corresponding corrective balance weights may be determined for offsetting the resolved rotor unbalances.

This invention relates to an analogy and vibration measurement device of high-speed revolving mechanic air-current exciting, which is characterized by the following: a high-speed revolving mechanic air-current exciting analogy and vibration measurement device which comprises the following steps: its rotor supporting and fixing on the checking platform, the driving device activating the rotor revolving, an air-seal assembling liner in the cylinder, the air-seal elaborating on the rotor, the liner and air-seal on the rotor constituting a labyrinth air-seal; an entrance in the middle of the cylinder which injects pressure to the cylinder through the air-line device; Signal measurement device contains many groups of sensors, which fixed two sensors in the entrance, exit, and stator air-seal gear of the cylinder and the shaft bearing shelf separately; Fitting a sensor on the end of the driving generator shaft bearing shelf; the signal of the sensor connects the multi-route datum device through the wire.

The invention discloses a rotor torsional vibration excitation and vibration analyzing experimental system, and belongs to the technical field of rotating machine experimental devices. The rotor torsional vibration excitation and vibration analyzing experimental system comprises a multi-span rotor test bed, a rotor torsional vibration exciting device and a rotor vibration monitoring and analyzing system. In the rotor torsional vibration exciting device, an alternating signal generated by a signal generator is processed by a power amplifier and a transformer and then is overlapped with an output signal of a direct current voltage stabilization linear power source, and the overlapped signals serve as the input of a direct current motor to enable the direct current motor to output fluctuation torque. A rotor of the multi-span rotor test bed generates torsional vibration under the excitation of the fluctuation torque, and the rotor transverse vibration and rotor torsional vibration are monitored by the rotor vibration monitoring and analyzing system. The excitation and measuring of the torsional vibration of the rotor system can be finished under the condition of a laboratory, and the rotor torsional vibration excitation and vibration analyzing experimental system can be used for studying the relation between the transverse vibration and the torsional vibration when the rotor system is excited by the torsional vibration, and analyzing the characters of the rotor system excited by the torsional vibration. The rotor torsional vibration excitation and vibration analyzing experimental system is easy to achieve and complete in function, and is mainly used for the fields of rotating machine scientific researches and teaching.

The invention discloses a fault diagnosis method of a compressor shafting based on a three-dimensional space axle center orbit, comprising the following steps: (1) detecting radial vibration signals x(t) and y(t) of a compressor rotor; (2) detecting an axial vibration signal z(t) of the compressor rotor; (3) carrying out low-pass filtering on the vibration signals to eliminate a high-frequency interference signal; (4) acquiring the three-dimensional axle center orbit w(t); (5) forming the three-dimensional axle center orbit; (6) respectively filtering the vibration signals x(t), y(t) and z(t) in three directions and then reconfiguring the vibration signals in a time domain to obtain the three-dimensional filter axle center orbit; and (7) synthesizing the vibration signals using a spectrum analysis principle to obtain the synthesized axle center orbit. The invention provides a three-dimensional vibration analysis method on the basis of a holo-spectrum technology, and the method comprises synthesized three-dimensional vibration analysis and filter three-dimensional vibration analysis, which can more clearly and vividly reflect running status and fault characteristics of equipment. Rotor vibration comprises horizontal, vertical and axial vibration, and the vibration signals in the three directions are synthesized to form the three-dimensional axle center orbit which comprises the three-dimensional filter axle center orbit and the three-dimensional synthesized axle center orbit. The method can really reflect motion situation of the axle center of the rotor and provide more complete information for the fault diagnosis.

The invention provides a rotor-rotor. The nonlinear dynamics analysis method for the bearing system comprises the following steps: inputting calculation parameters; Calculating a system overall mass matrix, a rigidity matrix, a damping matrix and a gyroscopic effect matrix; Calculating unbalanced excitation of the rotor; Calculating the thickness of the bearing oil film at the t moment; And calculating the bearing oil film pressure at the t moment. Judging whether the oil film pressure meets a convergence condition or not; Calculating a bearing friction force and an end leakage flow at a t moment; Calculating the effective temperature and effective viscosity of the lubricating oil at the t moment; And calculating the oil film bearing capacity at the t moment. Newmark-based And algorithm: calculating the vibration response of the rotor system at the t + t moment. And whether the break + t moment reaches a time upper limit is determined. According to the method, the bearing nonlinear oilfilm force solving process based on the finite difference method is embedded into calculation of the rotor vibration response, and influence factors such as lubricating oil rheological properties andbearing bush surface elastic deformation are considered when the oil film force is solved, so that the response calculation is more accurate.

The invention relates to a low rotating speed high precision control method of a control moment gyro gimbal servo system. The method solves the problems of friction interference and a disturbing moment caused by unbalanced rotor vibration of the control moment gyro gimbal servo system in a low speed operation process. The method comprises the steps of establishing a control moment gyro gimbal servo system kinetic model containing the friction interference and an unbalanced rotor vibration interference moment, performing control design on a frame servo system current loop via vector control andPI (proportional-integral) control methods, designing an interference observer to estimate equivalent interference formed by the friction interference and the disturbing moment caused by the unbalanced rotor vibration at a frame servo system speed loop, allowing the interference observer to offset an equivalent interference estimated value via a feedforward channel and designing a composite controller. The method has the advantages of high engineering practicability, high interference immunity and the like.

The proposed method for starting a motor having a stator, a rotor, a winding and an asymmetrical air gap, comprising the steps of: (a) exciting said winding with a current impulse such that said stator generates a magnetic field and going to one of steps (b) and (d); (b) driving said rotor to rotate in a first direction if a polarity of a portion of a specific tooth of said stator close to said air-gap and a polarity of a specific magnetic pole of said rotor corresponding to said tooth are opposite; (c) stopping said current impulse at a specific moment such that said rotor is rotated in a second direction by a cogging torque and going to step (f); (d) driving said rotor to rotate in a first direction if a polarity of a portion of a specific tooth of said stator close to said air-gap and a polarity of a specific magnetic pole of said rotor corresponding to said tooth are the same; (e) stopping said current impulse at said moment such that said rotor is rotated in a second direction by an inertia; and (f) detecting a back electromotive force (BEMF) in said winding when said rotor is rotated such that said motor is controlled for commutating according to said BEMF. The provided method overcomes the drawbacks of failing to position the rotor due to the oscillation of the rotor in the prior art.

The invention discloses a method for recognizing rotor rub-impact failure, which comprises using a kurtosis size of a rotor vibration signal as an objective function, selecting a second era wavelet predictor and a renovator in feature of self-adaptable matching rotor vibration signal to decompose the rotor signal; afterconditioning the decomposed rotor vibration signal with each frequency band by using fourier transform method to eliminate irrelevant frequency and extract hypo-harmonic in order to recognize the impact severe degree of the rotor. The invention excellently solves the problem decomposing frequency band overlapping of the second era wavelet, improves the accuracy for recognizing rotor rub-impact failure, and provides effective practical new technology for electromechanical device failure recognition; the invention is simple, reliable and suitable for engineering practice.

The invention provides a method for identifying the failure state of the rotor vibration signal of an aircraft engine. The method mainly includes the following steps of: firstly extracting 11 time domains and frequency domains and characteristics of time and frequency domains of the rotor vibration signal; selecting the proper characteristics by clustering; training a classifier by using the clustering result; at last introducing new data into the trained classifier to generate classification result. According to the method, the problem that, when in existing aircraft engine rotor failure state identification, the lots of extracted diagnosis characteristics have many uncorrelated or uncorrelated due to objective and subjective reasons is overcome. The method of classifying rotor vibration signal faults of the aircraft engine by using the combination of the clustering method and the classifier is adopted to provides a frame of the method for identifying the failure state of the rotor vibration signal of the aircraft engine, the key characteristic sensitive to the fault characteristic can be automatically identified, the correlated characteristics insensitive to the fault characteristic can be removed, and the performance of identifying the failure state of the rotor vibration signal of the aircraft engine can be effectively promoted.

Disclosed is a structural dynamic design method for a high-pressure rotor of an aircraft engine. The relationship between high-pressure rotor model design parameters and rotor vibration characteristics is determined, so that the design method and criterions are provided for dynamic design of the high-pressure rotor, and the method is of great guiding significance to the design of the high-pressure rotor of the aircraft engine. The method includes: establishing a dynamic model and a dynamic equation of the high-pressure rotor to obtain a nondimensionalization characteristic equation; introducing an equivalent critical speed, and determining a two-order critical speed range of a high-pressure rotor system according to the equivalent critical speed; changing a conventional equilibrium amount configuration method by configuring residual disequilibrium amount phases; configuring a ratio of rotor pole rotation inertia to mass center rotation inertia in design according to a specific design objective; establishing configuration criterions for a rotor bearing stiffness ratio. A conventional design process is changed, structural dynamic active design of the high-pressure rotor is realized, the design process is optimized beneficially, design cycle is shortened, and the method has important construction value.

A rotor system dynamic balance excitation identification method is disclosed. The method is characterized by carrying out experiment determination; collecting output of an eddy current sensor on a rotating shaft and acquiring an actual measurement value of a rotor vibration response; when a motor stops rotating, collecting a geometrical parameter and a material parameter of a rotor system and establishing a finite element model of the rotor system; through finite element simulation, acquiring a simulation value of the rotor vibration response; setting a rotor system dynamic balance excitation identification target function and an optimization model; and using an optimization algorithm to carry out iteration solution and acquiring an initial imbalance amount, bearing rigidity and a damping parameter of the rotor system. By using the method, a simulation result and an experiment result are optimized; based on parts of experiment data, through rotor system dynamic balance excitation possessing good robustness and identification precision, effective identification is performed; the method can be easily applied to actual engineering; and an application is less limited by an equipment result and a test condition.

The invention provides a rotary machinery fault feature extraction method based on self-adaptive wavelet energy. According to the invention, firstly rotor vibration signals are collected on a machinery fault comprehensive simulation experiment table, and then for the problem that signal energy features are influenced by the rotating speed and the sampling frequency, a new self-adaptive wavelet energy feature extraction method is adopted to complete effective feature extraction of a rotor imbalance fault, a misalignment fault and a bearing pedestal loosening fault of a rotor of the rotary machinery. In addition, in order to reserve more original features of the rotary machinery vibration signals and overcome the problems of a conventional denoising method that constant deviation and discontinuity exist at the threshold and parameters are not adjustable, a novel threshold function is embedded in the method for carrying out denoising. By adopting the method, a relatively good effect is obtained on the machinery fault simulation experiment table, and different fault types can be effectively distinguished by the extracted energy features.

The invention discloses a control method for realizing resuspension of a magnetic bearings system after temporary loss of control, and belongs to the field of magnetic bearings system. The control method for realizing the resuspension of the magnetic bearings system after the temporary loss of control is characterized in that a rotor position control module in a controller is used for controlling when the magnetic bearings system works normally, and a combined electromagnetic attracting force in direction opposite to the direction that the rotor deviates from a balance position can be applied to a rotor, thus ensuring that the rotor can be kept in the balance position where the suspension is to be stabilized; in case that the magnetic bearings system is subjected to temporary loss of control, a rotor speed control module in the controller is switched to control in order to apply the combined electromagnetic attracting force in the direction opposite to the rotor vibrating speed direction to the rotor, thus dissipating the rotor vibration energy caused by external distributing force, and as a result, the rotor vibrating speed can be reduced; then the rotor position control module in the controller is switched to control to enable the rotor to return to the balance position where the suspension is to be stabilized, so as to realize resuspension; the operation is convenient.

The invention discloses a detection method of a generator air-gap static-state eccentric fault orientation. The method comprises the following steps of 1) through a Hall voltage sensor, collecting voltage signals of induction coils on four vertical distribution measuring points of a stator circumference and outputting to an acquisition instrument; 2) comparing the four voltage signals and determining a static eccentric fault orientation and a fault degree. By using a technical scheme disclosed in the invention, the air-gap static eccentric fault in the generator can be simply, rapidly and reliably detected so that a disadvantage of a traditional diagnosis technology is overcome and maintenance and repairing of the generator are convenient, wherein a rotor vibration characteristic is a main part in the traditional diagnosis technology.

The invention relates to a method for monitoring and controlling safety risk of a steam turbine generator bearing on line. The method comprises: calculating fault probability of a bearing of the steam turbine generator, monitoring a rotor vibration signal of the steam turbine generator on line, monitoring a bearing bush metal temperature signal of the steam turbine generator on line, monitoring a bearing oil back temperature signal of the bearing on line, monitoring a bearing lubricating oil pressure signal on line, calculating an average maintenance time of the bearing, determining a weight coefficient of a bearing fault result, calculating a safe risk rank number of the steam turbine generator bearing, evaluating a safe risk grade of the steam turbine generator bearing, determining a maximum safe risk rank number of the steam turbine generator bearing, and recommending a risk control measure of the steam turbine generator bearing. The invention provides the method for monitoring and controlling the safety risk of the steam turbine generator bearing on line, and realizes the online calculation and control of the safety risk of the steam turbine generator bearing.