High-speed Elevator Research Articles

Microstructure and Property of Fe-based Wear-resistant Alloy Coating Prepared by Laser Cladding on the Surface of Super High-speed Elevator Parts

Aiming at the problem of poor wear-resistance of wear-resistant parts used in super high-speed elevator, the experiments of laser cladding to prepare composite coating were made. Fe-Cr-Ti-V-Mo-C powder was used as cladding material. The microstructure and property of composite coating were tested by relevant equipment. The research results show that the composite coating is made up of Cr3C2, TiC, VC, WC, Fe3C, Fe-based solid solution. The carbides present as network-like and distribute in solid solution. The average hardness of composite coating is 743 HV0.2, which is 91% higher than that of matrix. Using this technology to the surface strengthening of elevator parts, the wear resistance and service life can be greatly improved.

Robust Control of High-Speed Elevator Transverse Vibration Based on LMI Optimization

Aiming at the problem of transverse vibration of high-speed elevator caused by surface roughness excitation of guide rail and relative motion between car and car frame, firstly, this paper establishes an eight-degree-of-freedom active control model for the transverse vibration of the high-speed elevator separated of car from the car frame. Secondly, the transverse vibration state equation of the high-speed elevator is derived. The H2 norm is used to minimize the vibration acceleration of the car system. Based on Linear matrix inequality (LMI) optimization technology, a robust controller for the high-speed elevator is designed. Finally, the robust controller is solved by MATLAB and its simulation analysis is carried out. The results show that the vibration of the car and the car frame is inconsistent in actual operation. At the same time, the simulation results also show that the root mean square value, mean value and maximum value of the acceleration of the transverse vibration of the car and the car frame are reduced by more than 19% after using the robust controller. Therefore, the robust controller designed in this paper can effectively suppress the transverse vibration of the vibration car system.

Study on Aerodynamic Characteristics of Super High Speed Elevator

With the increase of elevator running speed, the influence of aerodynamic force on elevator becomes more and more obvious, and the impact is also increasing gradually. In this paper, the Computational Fluid Dynamic numerical simulation method is used to simulate and analyse the aerodynamic characteristics of elevator car under the influence of different operating speed and distance from side of car to hoistway wall by establishing full-scale model of elevator and hoistway. The results show that when the car is in a symmetrical position, the aerodynamic characteristics on both sides always show obvious symmetry. With the decrease of distance from side of car to hoistway wall and the operating speed of the car, the flow field around the car changes intensified, and the aerodynamic forces on the side of the car will also increase significantly.

Study on Transverse Vibration Characteristics of High-Speed Elevator under Gas-Solid Coupling

The purpose of this paper is to study the transverse vibration characteristics of highspeed elevator under the action of gas-solid coupling. A three-dimensional physical model of the high-speed elevator is established, the aerodynamic loads on the car under different transverse vibration states (translation and rotation) are numerically solved, and then the relationship between the different transverse vibration states of the car and the aerodynamic loads is obtained. The transverse vibration model of the high-speed elevator based on gas-solid coupling is established by transferring the attitude parameters and aerodynamic parameters of the car in real time combined with the guide excitation. Finally, the transverse vibration characteristics of high-speed elevators with or without gas-solid coupling are compared and analysed by solving the model with an example. The results show that the effect of gas-solid coupling on the transverse vibration acceleration peak value of high-speed elevator is greater when the running speed is greater than 4m/s, and the greater the speed, the more obvious the effect is, which provide some theoretical guidance for the analysis and control of the transverse vibration of high-speed elevator.

Sensitivity Analysis of Piston Wind in Hoistway of Super High-Speed Elevator

The piston wind will be produced when the car runs at high speed in the narrow and long hoistway, which will produce aerodynamic noise with the car enclosure and the hoistway walls, thus affecting ride comfort. In order to put forward better noise reduction measures, a piston wind model of super high-speed elevator with ventilation holes during the whole operation process was established firstly in this paper. Then, based on this theoretical model, the influence of the variation of ventilation-hole area, hoistway blockage ratio and car length on the piston wind was analysed separately. The analysis proved that the larger the area of ventilation holes, the more obvious the weakening of piston wind was when the building code permits. With the increase of blockage ratio, the intensity of piston wind increases obviously, but the duration of maximum piston wind does not change obviously. As the length of the car increases, there is no significant change in the movement of the piston wind, and this small change can be ignored in engineering applications.

Theoretical modeling and sensitivity analysis of the car-induced unsteady airflow in super high-speed elevator

The high-speed airflow generated by super high-speed elevators during operation causes significant aerodynamic noise, and research on the airflow characteristics in hoistways is necessary to effectively attenuate this noise. At present, the research on the airflow characteristics of super high-speed elevators lacks a systematic theoretical analysis of the entire elevator movement process. Therefore, the goal of this study was to develop a theoretical model of the entire process and conduct a parameter impact analysis of the car-induced airflow. First, Bernoulli's principle for unsteady flow is used to theoretically model the car-induced unsteady airflow, after which the validity of the model is verified by comparing the velocity coefficients of the theoretical results and the test data. Second, based on the theoretical model, the effects of four key parameters on the car-induced airflow and hoistway ventilation rate are analyzed, and a universal predictive formula for the hoistway ventilation rate accounting for the four parameters is proposed. Finally, the model of super high-speed elevators is simplified, theoretical modeling is carried out based on Bernoulli's principle for unsteady flow, and the influence of the ventilating holes at different positions on the car-induced airflow is analyzed.

Response analysis of non-linear compound random vibration of a high-speed elevator

This study presents a non-linear constitutive equation for the rolling guide-shoes associated with a high-speed elevator system. This was done to accurately evaluate the dynamic behavior of a high-speed elevator car and analyze the action mechanism of random factors during manufacturing and installation on the dispersion of vibration acceleration. Through the combination of the Hertz contact theory and the Bouc-Wen hysteretic model, the non-linear vibration model of the elevator car system was founded. This model was equivalent to a linear system by least squares technique, and then the random parameters and the random excitation were converted by random perturbation method and pseudo excitation method. The acceleration response sensitivities of each random parameters, the means and standard deviations of transverse vibration acceleration responses at the observation point were obtained. In the case, the transverse vibration acceleration responses of the car system were calculated. The elevator car’s vibration instance was analyzed under the different degrees of variation of the random parameters and the random excitation. The results showed that the randomness of geometric parameters has the greatest influence on transverse acceleration. The variability of parameters affects the dispersion degree of the transverse vibration responses while the variability of the excitation mainly affects the amplitude of the vibration response. This study provides an effective method for the analysis of non-linear compound random vibration responses of high-speed elevator car system, and provides a reference for the vibration control design and safety assessment.

Method of Deciding Air Pressure Adjustment Pattern for High Speed Elevator

We focused on the step-wise pattern of air pressure adjustment patterns applied to an air-pressure adjustment device for alleviation of ear stuffing that passengers feel in a cab of an elevator. Each step of the step-wise pattern consists of three elements which are the amount of air pressure change, the rate of air pressure change and the time with no change in air pressure. In this study, we have quantified the relationship between intensity level of ear stuffing and each of the three elements. And we have created relational expressions which can estimate the intensity level of ear stuffing from the three elements. Accordingly we can decide the most effectual air-pressure adjustment pattern for alleviation of ear stuffing with these relational expressions.

Study on horizontal vibration characteristics of high-speed elevator with airflow pressure disturbance and guiding system excitation

This paper aims to study the horizontal vibration dynamic characteristics of high-speed elevator by considering the combined effect of airflow and guiding system. The relationships of lateral force and overturning moment with horizontal displacement, deflection angle displacement and rated speed of the car are mathematically solved, and the horizontal vibration dynamic model of the car under the two excitations is established. For case model, the natural frequency and horizontal vibration response of the car are studied, and the guide-rail excitation frequency and car natural frequency are compared and analyzed. The results indicate that the higher the rated speed is, the more obvious the resonance phenomenon between the guide-rail and car will be in a certain range; the effect of airflow on horizontal vibration acceleration of the car with a speed lower than 6 m/s is small, but when the speed is over 6 m/s, the airflow will greatly affect the single-peak value of horizontal vibration acceleration, which is approximately a quadratic relationship; the deflection angle displacement has an increasing influence on horizontal vibration dynamic response with the increasing speed. The conclusions provide a theoretical guidance for the research and control on the horizontal vibration of high-speed elevator.

Intelligent control of active shock absorber for high-speed elevator car

Due to the influencing factors, such as irregularity of guide, piston wind excitation in the hoistway, and uncertain swinging of hoisting rope during the operation of high-speed traction elevator, car will produce dramatic horizontal vibration. With the purpose of suppressing this vibration effectively, the active car shock absorber is designed with linear motor, and a five-degrees-of-freedom space vibration model of the car is established and, subsequently, its state space equation is derived. For the uncertainty external excitation in the car system, the back propagation neural network proportional–integral–derivative controller with linear prediction model is designed for the intelligent active control of the vibration of the car, and simulation analysis is carried out with MATLAB/Simulink. The result shows that the active shock absorber designed in this study can effectively suppress the horizontal vibration of high-speed elevator car, better than traditional proportional–integral–derivative controller. This study has opened up a new idea of high-speed elevator vibration damping method, and is of important referential significance for the field of active control of car vibration.

MCU System-based Intelligent High-speed Elevator Door Operator Fault Analysis and Research

The elevator hall door lock MCU system is the important safety core component installed on the elevator. It can monitor the fault information of the elevator operation in real time. At present, MCU system can not adapt to the changes in the application of the intelligent high-speed elevator. This paper first analyzes the reasons of MCU system fault on the intelligent high-speed elevator based on the actual case analysis, and summarizes the optimization measures for the safety monitoring, and provides reference for the further research on the performance and the system intelligent technology of the intelligent high-speed elevator door operator system.

Response analysis of the composite random vibration of a high-speed elevator considering the nonlinearity of guide shoe

As a result of unevenness (or non-uniformity) of elevator guide rails, an elevator car experiences horizontal vibration in the vertical motion of an elevator run. To improve the accuracy of the car vibration model and analyze the influence of uncertainty factors on the vibration response, the nonlinear characteristics of rolling guide shoes, randomness of car parameters, and random excitation of guide rails need to be considered. Based on the Hertz contact theory, the functional relationship between the amount of deformation of rolling guide shoes and restoring force was derived, and a nonlinear model of rolling guide shoes was established. The average responses of the composite random vibration of a high-speed elevator were determined by the orthogonal polynomial approximation method, and the standard deviations were determined by the complex Cotes integration method. With a two-degree-of-freedom high-speed elevator car system as the research object, the horizontal vibration responses were analyzed under the condition of variation of parameters and the irregularity of the guide rails. The results showed that the variation of parameters mainly affected the dispersion extent of the horizontal vibration responses of the car, and the irregularity of the guide rails mainly affected the amplitude of the vibration responses. This study provided an effective method for analyzing composite random vibration responses of a high-speed elevator car system, and provided a reference for anti-vibration design and safety assessment.

Analysis of Transverse Vibration Acceleration of a High-Speed Elevator with Random Parameters under Random Excitation

The randomness of a high-speed elevator car system’s parameters was caused by manufacturing and installation error. In order to more accurately evaluate the dynamic behavior of the elevator car, the compound vibration problems containing both random excitation and random parameters were studied. The deterministic part and random part of the acceleration response were derived by the perturbation theory, and the vibration image in the time domain and frequency domain were analyzed. The sensitivity expressions of each parameter to the system response were established in the random vibration system. The acceleration standard deviation due to random excitation was calculated by the pseudo excitation method. The acceleration standard deviation due to the random parameters was obtained according to the displacement response covariance matrix and random parameters covariance matrix. The discrete degree of random excitation and random parameters on the transverse acceleration of the car was analyzed in an example, and the influence degree of each parameter on acceleration responses was quantitatively described by calculating the response sensitivity of random parameters. This paper provides an effective method for the analysis of the vibration characteristics of the high speed elevator car system.

Analysis of Transverse Vibration Acceleration for a High-speed Elevator with Random Parameter Based on Perturbation Theory

Analysis of Transverse Vibration Acceleration for a High-speed Elevator with Random Parameter Based on Perturbation Theory

Research and Improvement of the High-speed Elevator Over-speed Governor

This paper focuses on the issues that the action speed of the traditional mechanical over-speed governor could not follow the speed of the car and the over-speed governor action speed is not precise, which are significant in the elevator safety and the whole cost of elevator. A new governor called mechanical-electronic over-speed governor without altering the original mechanical governor had been present to improve the performance of mechanical governor. The structure, control part and the principle of the mechanical-electronic governor had been given in this article. Based on the design of the mechanical-electronic governor, data analysis interrelated have been given. The result shows that this design could significantly increase the safety performance of high-speed elevator, and has important reference value in the elevator design. Mechanical-electronic over-speed governor has great significance not only for the safety of elevator but also for shortening distance of pit and overhead. Using this method, lower speed governor and shorter distance of pit and overhead could be chosen for high-speed elevator to improve the elevator safety and reduce the whole cost.

Modeling of High Speed Elevator Traction Machine Base and Investigation of Vibration Isolator

Modeling of High Speed Elevator Traction Machine Base and Investigation of Vibration Isolator

超高速エレベータ向けSiC適用小型変換器の検討

超高速エレベータ向けSiC適用小型変換器の検討

ANALYSIS OF INFLUENCE OF DESIGN CHARACTERISTICS OF INCLINED BUCKET ELEVATOR ON THE POWER OF ITS DRIVE

Purpose.One of the main elements of the inclined belt bucket elevators is their drive. To determine the drive power, it is necessary to carry out calculations according to standard methods, which are described in the modern literature. The basic design parameters are the productivity, lifting height, type and properties of the transported material, the angle of inclination. It is necessary to build a parametric dependence of the driving power of the elevator on its design parameters, which takes into account the standard sizes and types of buckets and belts. Methodology. Using the methodology of traction calculation of inclined belt bucket elevator there were built parametric dependences of efforts in specific points of the route of the elevator, as well as the parametric dependences of the drive power of high-speed elevators with deep and shallow buckets on their design parameters and characteristics. Findings. On the basis of constructed parametric dependencies, it was found that the function of changing the value of the elevator’s power from design capacity (at fixed lifting height, type of cargo, belt speed) is piecewise constant and monotonically increasing. It was built a graphical representation of elevator drive power on the angle of its inclination within acceptable limits of change. The resulting relationship is non-linear and monotonically decreasing. In general terms the intervals of project performance values, which provide a constant value of drive power of inclined elevator were defined. As an example of the obtained results it was observed the process of dependence construction of the drive power on design capacity and inclination angle of the elevator for transporting the fine coal. Originality. For the first time there were constructed the parametric dependences of drive power of inclined bucket elevator on its design parameters that take into account the standard sizes and types of buckets and belts. Practical value. Using the constructed dependencies enables relatively quick determination of the approximate value of the drive power of high-speed inclined elevators with deep and shallow buckets at the design stage and high-quality selection of its basic elements in the design of specific characteristics: type of cargo, productivity, lifting height, angle of inclination.

INFLUENCE ANALYSES OF DESIGNED CHARACTERISTICS OF THE ELEVATOR TO THE PARAMETERS OF ITS DRIVE

Purpose. A drive behaves to the basic elements of scoop band elevators. To determine the drive power calculations are carried out according to standard methods, which take plenty of time. It is necessary to conduct the analysis of influence of project characteristics on the parameters of high-speed drive in a scoop bent elevator and to build the improved algorithm of speed-up determination of its drive power on project descriptions, that will take into account the type of load, rise height, necessary productivity, standard parameters of scoops and tape. Methodology. Using parametric dependences of elevators drive power on its project characteristics, received by the author earlier, the improved algorithm of speed-up determination of elevators high-speed drive power with deep and shallow scoops at set type of load, productivity, rise height was offered. Findings. The algorithm of drive power speed-up determination of high-speed vertical elevators with deep and shallow scoops depending on project parameters was offered. The example of such algorithm application is considered for an elevator that is intended for transporting of cement. Analytical dependences of drive power of such elevator are determined on the productivity and rise height. Corresponding graphic dependences were built and character of drive power changes during the size changing of any project characteristics was determined. Originality. The improved algorithm of drive power elevator determination at the given project characteristics (type of load, rise height, productivity) that takes into account standard sizes, parameters of scoops and ribbons, was built at first time. Practical value. The use of an offered algorithm of calculation gives the possibility of relatively fast determination of reference value of high-speed elevators drive power with deep and shallow scoops, to build graphic dependences of drive power on the values of the productivity and rise height at the certain type of load, that assists the quality selection of his basic elements at certain project descriptions, such algorithm gives an opportunity to save time on calculations in the process of elevators planning.

RESEARCH OF INFLUENCING OF PROJECT DISCRIPTIONS OF ELEVATOR ON PARAMETERS OF ITS DRIVE

Purpose.One of basic elements of band bucket elevators is their drive. For determination of power drive it is necessary to conduct calculations on standard by methods, in what it is needed to expend enough time. One of project parameters is productivity of elevator. It is necessary to build parametric dependence of power drive of elevator on its design capacity that takes into account a type and descriptions of load, lifting height, standard sizes and parameters of buckets and tapes. Methodology. Using the method of hauling calculation of band buckets elevators, the parametric dependences of power drive of high-speed elevators are built with deep and shallow buckets from their productivity at fixed type of load and height of getting up. Findings.It is set on the basis of the built parametric dependences that the change function of a size of elevator power from design capacity (at fixed to the lifting height, load type, rate of tape movement) is piecewise and droningly increasing. The intervals of project values of productivity, which provide the permanent size of elevator power drive are certain in a general view. As the example of application of the recived results the construction process of power drive dependence from design capacity of elevator of shotblasting room, which is intended for transporting of the metallic shot using for consolidating of carriage springs, is considered. For concrete type of load and lifting height of such elevator graphic dependence of power drive on productivity was built. Originality.Parametric dependences of elevator power drive on its design capacity were first built, which take into account a type and physical and mechanical descriptions of load, lifting height, standard sizes and parameters of buckets and tapes. Practical value. The use of the built dependences enables in relation to rapid determination of approximate value of power drive of vertical high-speed elevators with deep and shallow buckets on the stage of planning and to execute the high-quality selection of its basic elements at concrete project descriptions: type of load, productivity, lifting height.