This paper contains an account of an electromagnetic method of testing for mechanical flaws in wire ropes such as colliery winding ropes, the method comprising the use of a ÃÂÿsearch band of flux ÃÂÿ in combination with a search-coil system. In the introduction are detailed the advantages of the use of alternating as compared with direct current for the excitation of the magnet system. Section 1 describes the results of an experimental investigation of the penetration of magnetic flux in ÃÂÿlocked coilÃÂÿ wire ropes, for a supply frequency of 50 and 20 cycles per second respectively. In Section 2 the effect of mechanical strain on magnetic permeability is considered, with special reference to a.c. excitation. In Section 3 the change in reluctance of the air space due to eccentricity of the rope in the magnet system is examined. Section 4 contains an account of the construction of the rope-testing magnet system, and the method of utilizing the search band of flux is explained. Section 5 contains the results of tests on a length of wire rope which was specially constructed for the purpose by Messrs. Latch and Batchelor, and in which a series of hidden flaws were incorporated. A complete rope-testing equipment constructed in accordance with the principles explained in this paper has been installed in one of the Carlton Main Co.'s collieries in south Yorkshire.
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机译:本文介绍了一种电磁方法,用于测试钢丝绳(例如,煤矿用钢丝绳)中的机械缺陷,该方法包括使用ƒƒβ磁通量搜索谱带。结合搜索线圈系统。在引言中详细介绍了与直流电相比,使用交流电对磁体系统进行励磁的优势。第1节介绍了磁通量在Ã’,锁定线圈âÂ,钢丝绳中的渗透率的实验研究的结果,其供电频率分别为每秒50和20个周期。在第2节中,考虑了机械应变对磁导率的影响,并特别参考了a.c.激发。在第3节中,研究了由于磁铁系统中绳索偏心引起的气室磁阻的变化。第4节介绍了绳索测试磁体系统的结构,并说明了利用磁通搜索带的方法。第5节包含针对一段长度的钢丝绳的测试结果,该钢丝绳是由Latch和Batchelor先生专门建造的,其中并入了一系列隐藏的缺陷。根据本文介绍的原理构造的完整的绳索测试设备已安装在南约克郡的Carlton Main Co.煤矿之一中。
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