工业电机中的滚动轴承噪声

在工业电机出厂检验以及运行过程的机械故障中，轴承的噪声问题一直是困扰各界的重要问题。越来越多的专业人士开始关注如何降低轴承的噪声，如何判别轴承的非正常噪声，对电机中轴承的噪声问题也进行了深入地研究。从轴承的正常噪声机理人手，介绍影响轴承噪声的几个重要因素，同时提出了相应的解决方案。     

关于电机轴承噪声问题的分析和解决措施

1 引言 电机噪声主要有电磁噪声、机械噪声、通风噪声等,其中机械噪声中以轴承噪声最为突出,常常使电机噪声超过限制标准,直接影响到电机质量,使电机容易过早出现故障,给电机制造厂家造成一定程度上的经济损失和信誉流失,同时对生产环境造成极大的影响.如何解决电机轴承噪声问题就自然成为电机制造行业特别关注的问题.     

装配工艺对电机噪声的影响

降低电机噪声是环境保护中的一个重要问题。国内外对此进行了大量的研究改进工作,收到一定效果。我们就电机装配质量对电机噪声的影响问题,介绍我们进行的一些工作和体会。一、轴承处理工艺对电机噪声的影响 1.轴承装配工艺的影响我厂轴承装配原用热套工艺,后来为提高效率改为冷压装,发现装配后的电机噪声较大,于是又重新采用热套工艺,噪声降了     

关于Y2电机轴承噪声分析及解决方法

0 引言 轴承噪声是电机的一项重要质量考核指标,但在电机出厂试验的噪声测试中常出现噪声值超标.针对这一现象我们展开了专项研究.怎样才能从根本上解决这一问题,我们首先对电机进行拆机检查,更换轴承后电机做出厂试验时仍有轴承噪声.我们又从产品制造上找原因,分析在加工的过程中到底哪一环节存在问题,最终找出影响电机产品质量的关键所在.     

电机噪声与轴承使用的探讨

电机的轴承噪声分析其原因,一般为二个主要因素决定,(1)轴承的质量,(2)轴承安装的质量(包括轴承的内外径配合,轴向予压力及装配工艺)。为了使低噪声电机的噪声稳定、达到产品标准,我们选用上海红星轴承厂202Z_1级轴承与 YYK—180空调用风扇电动机作了配套试验。图1反映了电机噪声随轴承噪声而增加的关系。同一工艺水平的电机噪声值相对轴承噪声增加14dB,当轴承噪声大于41dB 时,电机噪声就将超过该电机的技术要求规定值(55dB)。目前红星厂 Z_1级电机轴承出厂噪声的保证值为43dB,已低于国标3dB。因此如何从轴承安装质量入手,降低噪声是当前设     

探讨洗衣机电机轴承应用中的振动与噪声问题

本文针对一种洗衣机电机用滚动轴承6202 2Z,应用阶次分析等故障诊断方法,对轴承应用过程中几种典型故障带来的噪声与振动问题进行分析。滚动轴承每一个部分都有相应的特征频率,由此推测与轴承组装使用方面的问题,查找原因,寻求解决方案。电机作为洗衣机的动力源,是噪声优化改善的关键部件,而作为重点高速部件的轴承,优化其振动与噪声问题.则显得尤为重要。所以,轴承在应用方面的振动与噪声的故障诊断和分析,对电机的设计、生产、应用有着重要的指导意义。     

小型电机的轴承与噪声

电机的振动和噪声是衡量中小型电机质量的指标之一。在电机振动和噪声的研究中,滚动轴承零件产生的振动和噪声是整机振动和噪声的重要因素。因而在中小型电机中合理使用滚动轴承,控制轴承振动和噪声也是降低电机振动和噪声的有效措施。为使读者对滚动轴承振动和噪声的基本情况有所了解,现对电机轴承振动和噪声的使用概况和引起原因提出以下几点看法,供使用轴承时参考。下面以交流异步电机用向心球轴承为例,讨论电机轴承的应用。一、轴承结构和振动、噪声产生原因滚动轴承振动和噪声的关系是十分密切的,从     

电机轴承装配工艺与噪声振动的影响

在小型异步电机的噪声问题中,轴承噪声时常起着举足轻重的作用。新的“电机基本技术要求”国际(GB755-81)中将电机的噪声功率级分成 N、R、S、E四个等级(见表一所列)。同一台电机的噪声往往因为轴承噪声的变化可以从优级变成不合格品,上下相差20多分贝。从本刊第6期登载“降低小型异步电机轴承噪声的分析研究”一文中可见,引起轴承噪声变化的主要因素有三个方面:一是轴承本身的质量问题;二是电机的轴承结构、尺寸配合公差和加工质量问题;三是轴承的装配工艺问题。本文所谈的就这第三个方面的问题。     

电机轴承装配工艺对电机噪声、振动的影响

在小型异步电机的噪声振动问题中,轴承常常起着举足轻重的作用,同一台电机噪声、振动往往可能因为轴承噪声、振动的变化从优级变成不合格品,噪声大小之差可达20dB(A)以上,引起轴承噪声变化的原因有三个方面:一是轴承本身的质量问题;(这是一个主要的问题);二是电机的轴承结构,尺寸配合公差和加工质量问题;三是轴承的装配工艺问题。本文所谈的是第三个方面的问题。     

电机轴承噪声与轴承室尺寸精度

噪声是Y系列电机的主要质量指标之一。在噪声不合格的电机中,约有80％是由于轴承噪声过大所致。以往认为,电机轴承噪声是因轴承本身质量引起的,每当噪声超过指标时,就采用更换轴承的办法来弥补。我厂在一次质量检查时,12台Y225S-4电机中有9台噪声值超标,更换轴承后仍有4台     

Minimizing electric bearing currents in ASD systems

During recent years, an increase in bearing failures has been seen in ASD-fed electric motors, as well as in gearboxes, and other connected machinery, caused by electric current flow through such bearings. The theories presented in this paper focus on bearing currents in ASDs of the voltage source pulse width modulated (PWM) type, for use with AC induction motors, although the concepts are applicable to various types AC and DC drive systems     

Sleeve versus antifriction bearings: selection of the optimal bearing for induction motors

The decision between which hearing type to utilize is not always easy or even obvious. There is no choice in bearing selection on small motors (less than 200 hp), where only antifriction bearings (AFBs) are readily available. Likewise, a choice does not always exist on larger motors in excess of 2000 hp, where various design requirements leave only the sleeve bearing (or tilting pad bearing) as a viable option. On intermediate size motors, a choice will have to be made. In general, AFBs are less expensive, and result in a more compact motor. However, there are potential disadvantages associated with AFBs. The "best" bearing decision depends on the details of the particular application. This paper explores the advantages/disadvantages of both types of bearings. Additionally, it provides guidelines to help select the best bearing for the application. Judicious selection of bearings will result in motor purchasing savings without sacrificing process reliability.     

电机异常噪声的分析判断

应用振动分析法对轴承中、低频振动及电机中低频振动和噪声之间的关系进行研究，以典型实例说明在中低频段考核轴承振动的必要性。     

大中型电机轴承及润滑方式的选择

主要论述了电机设计过程中轴承及其润滑方式的选择问题,并对滑动轴承及滚动轴承分别作了详细的介绍。其中介绍了滑动轴承润滑冷却方式的确定方法及润滑油牌号的选择;对滚动轴承则介绍了轴承牌号、尺寸及润滑方式的选择。最后结合实际应用对两种轴承分别进行了举例说明。     

大中型立式电动机（大附加轴向力）的轴承结构的研究

阐述了大附加轴向力稀油润滑的滚动轴承支承的立式电动机的轴承结构及其冷却方式、推力滑动轴承的轴承结构及其冷却方式,以及在设计轴承结构时需要考虑的技术要点。     

Vertical motor-bearing systems

The number one reason for the removal of vertical motors from service is the failure of the bearing system. These systems can be much more complicated than those used in horizontal motors. This article addresses various bearing configurations for definite-purpose vertical motors, along with their various accessories. Issues associated with design specifications, installation, operation, maintenance, and repairs are also addressed. The purpose of this article is to present the various bearing systems used in vertical motors and the reasons why these systems can fail prematurely. Suggestions will be given for extending the bearing life, including how to specify these bearings and their accessories correctly. The motors used in this article includes motors up to 5,000 hp, all speeds, and enclosures.     

Anti-friction bearing temperature rise for NEMA frame motors

An acceptable antifriction bearing temperature is recommended, and, in particular, the location for monitoring the bearing temperature rise for NEMA frame chemical industry severe-duty squirrel-cage induction motors is identified. The relationship between the bearing temperature rise and stator winding temperature rise is investigated. An overview of the types of antifriction bearings most commonly used, criteria for the selection of such bearings, and factors affecting bearing life is presented     

钢球磨煤机系统的轴承故障诊断与分析

几个电厂的多台钢球磨煤机减速机或电机经常发生轴承损坏故障,通过对发生异常的磨煤机系统的振动情况进行现场测试,发现主要的振动频率为磨煤机小牙轮与大齿轮的啮合频率;另外,经常发生损坏的轴承其滚动体故障频率与该频率也比较接近或重合,说明造成齿轮啮合频率与滚动轴承故障频率相重合会降低滚动轴承的使用寿命.     

Scaling Effects of Inverter-Induced Bearing Currents in AC Machines

In this survey paper, we show by straightforward mathematical scaling considerations that small inverter-fed ac motors of up to typical 20 kW at 1500/min are likely to suffer from discharge (electric discharge machining) bearing currents, whereas larger motors are likely to be subjected to high-frequency (HF) circulating bearing currents. When comparing motors that operate at the same voltage level, the resulting bearing-current density is high for very small and very large motors. Smaller values occur in between these two extremes with medium size motors in the range of 10-100 kW. Therefore, electric bearing insulation is useful for larger motors to interrupt the HF circulating bearing-current path, whereas small motors need rotor shielding, common-mode voltage filters, or hybrid bearings.     

Motor bearing systems

Numerous bearing systems are used in the electric motor industry. These systems even vary for a given manufacturer based on the motor size, type, enclosure, speed, and application. This article focuses on anti-friction rolling-element, grease- or oil-lubricated bearings used in vertical and horizontal motors. Although common in large motors, the hydrodynamic sleeve and plate-type bearings are beyond the scope of this article. The primary focus is on industrial applications that use more traditional types of bearings, lubricating systems, and enclosures. It is acknowledged that there are other specialized bearings in operation and other types of machinery where the principles of the article may have application. A comparison is made between the different types of bearing systems available. Loading, speed, coupling, and life factors are considered. The various methods of lubrication, sealing, mounting, and clamping are reviewed. Recommendations are given for a wide variety of industrial applications. The primary focus of this article is on conrad-type ball bearings, with the understanding that other types of bearings are, used for specific applications. These bearings can be open, shielded, or sealed.