有刷DC电机与无刷DC电机的比较.doc

国外论坛看到的一篇文章,供大家参考:DC Brushed MotorsDewalt-Brushed-Motor.jpg (28.58 KB, 下载次数: 6)下载附件 保存到相册 2012-2-26 19:35 上传A basic brushed motor has an armature (rotor), commutator, brushes, axle and permanent magnets. Current is applied through the brushes, which are in physical and electrical contact with the commutator. Current then passes through the coiled armature, creating a magnetic field.The created magnetic fields interact with those of the permanent magnets that surround the armature, causing the armature to rotate around the axle. If you apply greater current, such as when you squeeze the trigger of a cordless power tool harder, you will create stronger magnetic fields in the armature, resulting in greater interaction forces and thus faster rotation.As you can see in the diagram, highlighted in red, the brushes are in contact with the commutator. Friction between the brushes and the commutator results in a slight drop in speed and thermal energy losses. In addition, the brushes may need to be replaced periodically as they wear out over time with use.DC Brushless Motors2.jpg (36.6 KB, 下载次数: 3)下载附件 保存到相册 2012-2-26 19:36 上传In a brushless motor, there are no brushes, and thus no physical contact that could lead to frictional energy losses. Instead of the armature being located on the rotor with permanent magnets fixed to the surrounding shell (stator), permanent magnets are located on the brushless rotor with the armatures electromagnetic coils in fixed positions surrounding it.In a brushed motor, the commutator reverses the current flow through the armature coils, flipping the magnetic fields so that the rotor continues to spin. In a brushless motor, an electronic control switches the phase of current through the armature windings at precise timings to accomplish the rotational response.Brushless vs. Brushed MotorsBrushless motors are more expensive to design and manufacture, but they are typically more efficient than brushed motors. This leads to: less maintenance and longer life less noise and more power compact size and longer runtimeBrushless Cordless Power ToolsSeveral brands already offer a couple of cordless power tools with brushless motors. With Dewalt and Milwaukee joining the club, we predict that others brands are going to follow the trend, if not in 2012 then most certainly in 2013. Initially, brushless motors will only be found in drills, drivers, and impact wrenches, but we anticipate that saws and other tool types may be redesigned to accommodate the new tech as well.Additional ConsiderationsA brushless vs. brushed motor comparison is not exactly as black and white as described. For example, moving the armature from the rotor to the stator also results in a decrease in mass and radial mass distribution of the rotor. In other words, the rotor of a brushless motor often has a much lower moment of inertia than that of a brushed motor. This means that a brushed motor rotor is more resistant to rotation. (Visualize a spinning ice skater with their arms reaching out vs. at their sides.)So its not just about boosting efficiency by reducing brush-commutator frictional energy losses. Additional fundamental advantages of brushless motors include improved heat dissipation, flatter torque, reduced electrical noise, and greater power output.目前看来,直流产品使用无刷电机,已经成为直流产品继锂电以后的又一个发展趋势了.其实无刷电机已经在一些专业的直流品牌上使用了,象松下HITACHIMAKITAPROTOOL等品牌的新款直流产品上已经基本是使用无刷电机了.相对于常规的直流电机,无刷电机具有体积小、噪音小、效率高、过载能力强、寿命长等明显的优点，当然，也不存在EMC方面的问题。下面是无刷电机的一个简单的图例介绍：AAA.jpg (78.31 KB, 下载次数: 15)下载附件 保存到相册 2011-11-20 17:20 上传下面是目前已经在市场上使用无刷电机的一些主流专业品牌使用无刷电机的机器：3.jpg (29.18 KB, 下载次数: 11)下载附件 保存到相册 2011-11-20 17:21 上传4.jpg (26.74 KB, 下载次数: 10)下载附件 保存到相册 2011-11-20 17:21 上传5.jpg (80.08 KB, 下载次数: 6)下载附件 保存到相册 2011-11-20 17:21 上传6.jpg (83.67 KB, 下载次数: 12)下载附件 保存到相册 2011-11-20 17:21 上传7.jpg (16.42 KB, 下载次数: 8)下载附件 保存到相册 2011-11-20 17:21 上传目前象DEWALT的新款也基本使用了无刷电机：Dewalt-20V-Max-Cordless-Power-Tool-Drill-DCD780C2_1.jpg (33.33 KB, 下载次数: 10)下载附件 保存到相册 2011-11-20 17:28 上传而BOSCH在这方面好象晚了点，BOSCH网站上查到的新款枪钻的产品介绍上写的用的还是四极电机：r04926v43.JPG (34.83 KB, 下载次数: 4)下载附件 保存到相册 2011-11-20 17:30 上传而Milwaukee的新的LI电系列也使用了无刷电机：Milwaukee-FUEL-Drill-Drivers.jpg (33.34 KB, 下载次数: 5)下载附件 保存到相册 2011-11-20 17:32 上传m18fuel.jpg (70.58 KB, 下载次数: 0)下载附件 保存到相册 2011-11-20 21:28 上传相关帖子 今后微电机产品发展趋势 稀土永磁电机的发展趋势 车王德克斯锂电池全系列产品 交流电锤改装后 电锤打墙壁上不平的地方，对机器损坏特别大 电机保护常识 解读现代家具五金产品的发展趋势 钢盾工具：以产品为核心 国内五金工具应向高端领域发展 国内外五金气动工具：市场发展方向分电动工具的核心部件是电机和控制器，最近几年来，行业内存在着“有刷派”和“无刷派”两派之争，众多技术专家表示，无刷电机和无刷控制器与有刷的相比，性能好，技术含量高，是行业的发展方向，但是无刷电机的研制相当复杂，因此一直未得到快速的发展，而在国家节能、环保、绿色发展方针调控下，不少企业加大了 对无刷电机研发的投入，并已取得显著成效。市场反馈表明，无刷电机的诸多优越性使其市场地位越来越高，取代有刷电机市场地位已逐渐成为现实。/ |2 x# t2 y, 4 8 b1 S+ r C wL6 * U# Y# l3 e! m3 W& F0 h) 6 e4 ! B6 G z6 r# e4 R/ T6 E+ O5 y炭刷作为电动工具行业最消耗最大的产品，一直是电动工具生产厂家利益的主要来源或与产品绑定打开市场缺口的主要手段，也养活了大批碳刷配件生产厂家。而随着直流无刷电机的兴起，这个曾经风光一时的五金配件产业或将退出历史舞台。: c/ & y4 F: Q1 R+ i5 K9 q炭刷或将退出电动工具市场- & 2 Y( a3 k3 ) C$ t! J5 u5 9 M5 V: G. d8 s众多技术专家表示，无刷电机和无刷控制器与有刷的相比，性能好，技术含量高，是行业的发展方向。3 f 6 N: M7 F& S5 A( jr7 ) x! B与有刷电机相比，无刷电机拥有噪音小，没有粉尘，没有磨损等优点，拥有越来越多的认可客户。) 9 u$ p7 i5 i! f/ - Y; iV6 g- p, j据介绍，因为无刷电机没有碳刷，那么它就噪音小，没有粉尘，没有磨损，效率高，节能。可以在任何地方使用，特别是无尘厂房。有刷的电机他是因为有碳刷，所以有磨损，维修困难，噪音大，有粉尘，不能用在无尘厂房等地方。( . g2 n1 K4 n+ X& I9 X! hW- ?0 Y- h+ p7 N有刷电机与无刷电机的基本对比 H% E% ; E5 i5 a& j# T6 Q& j + Rw. v B4 j2 s! h有刷的电机他是因为有碳刷，所以易磨损，寿命短，噪音大，有粉尘，不能用在无尘厂房等地方！/ n% g/ O L|: g% y# c; i% G( p6 O4 x6 Q- D. P4 ( s! c有刷电机功率大，调速电路比较简单，结构简单，缺点是内部的碳刷易磨损，噪音大。有刷电机寿命较短，有刷电机可能每隔两年要换一次碳刷。如果相关部件磨损如换相器磨损严重也需要更换。. n8 l: wg* r1 w3 & N8 n7 U3 . - c; f$ 5 P$ n# O无刷电机无机械磨损，损噪音小。省电,寿命长,免维护,但价格相对较高。6 8 y% C& k2 uj6 Q& m; Z# c: x9 S5 B无刷机的换向是通过电子换向实现的，无任何接触也就