【摘要】 本文对JKM(Ⅰ)型多绳提升机的几个机型的振动特性及其影响因素进行了理论分析和实验研究,指出了该类型机器在生产运行中出现强烈振动的原因,提出了改进措施。对某矿主井提升机进行了具体分析,找到了症结所在,所得结论可用于对现场使用的JKM(Ⅰ)型提升机的消振。更多还原

【Abstract】 Vibration characteristic and contributing factors in it are significant for the shock reduction of multirope hoist, especially in case of overrunning vibration taking place in operation. So, study on it is valuable to the choice of means by which to climinate abnormal shock in operation of a hoist is possible. This paper presents the result of study which provides a sound basis for resolving further the abnormal operation problem theoretically and practically.Summary. Three types of JKM-1 Series mine hoist with reducer spring-loaded have been experimentally investigated. Vibration characteristic calculation based on a mechanical model of the hoist system, as shown in Fig.1, is performed to determine eigenvalues and eigenvectors in this chain system by means of transfer matrix without formulating stiffness and mass matrices. In this way, the natural frequency calculating the five preceding orders together with their correspondent vibration modes are given by computer. A frequency ratio of vibration source to the natural frequency of chain system, taking just the first order in account, has been calculated. Among the three types of JKM-1 Series hoist, this frequency ratios are 0.92 and 0.91 for two and 0.71 for the other one. The fact implies that the former two are in the resonant region. Factors contributing in vibration characteristic of hoist are analyzed through tests.1. Connection stiffness of coupling between hoister and driving motor has great influence on the natural frequency of hoist system. Compared with loosely coupling, the natural frequency of closely coupling is about 30% higher and the damping ratio is correspondingly raised from 0.061 to 0.088.2. Shape and structure of springs in elastic coupling have influence on shock exitation caused by the coupling. Shock exitation will be significantly decreased if replacing the S-shaped leaf springs by single leaf springs with closely controlled size tolerance. 3. Backlash between teeth space and spring leafs in elastic coupling has influence on the natural frequency of hoist system. The smaller the backlash, the higher the natural frequency is. Smaller backlash is favourable for making an effort to keep the frequency of hoist system out of resonant region.4. Finally, the relative axial displacement between the two halfcoupl-ings is also a contributing factor. The longer the displacement, the smaller the stiffness of hoist system is.The above views have been justified by shock elimination practice in situ.Fig.1 Schematic of a multirope hoist with reducer spring-loaded (a) andits mechanical model (b) Fig.2 Main vibration modes calculating first order only Fig.3 Static free attenuation (a) and dynamic resonance (b) measuredFig.4 Responce of hoist system using different springsFig.5 Influence of backlash between spring leaf and teeth space in an elastic coupling on natural frequency of hoist systemFig.6 Influence of relative axial displacement between two half-couplings on natural frequency of hoist systemFig.7 Frequency-responce curve of hoist systemFig.8 Dependence of natural frequency on relative axial displacementFig.9 Static free attenuation (a) and dynamic amplitude-frequency curve(b) measuredTab.1 Natural frequencies calculating the five preceding orders Tab.2 Influence of clearance between bearing and hoister shaft on naturalfrequency of hoist system更多还原