With the direct-drive technology, linear motor and the traditional "rotary servo motor + ball screw" in contrast to drive the industry's concern.
The British in 1845 had invented the linear electric motor, but the linear motor air-gap is too large resulting in low efficiency, can not be applied. 19th century 70s Kollmorgen also launched, but due to the high cost and low efficiency limited its development. 70s until the 20th century, the linear motor to the progressive development and application of some special area, the 20th century, the beginning of 90's linear motor used in the machine manufacturing industry, now some of the world's technologically advanced manufacturers of machining centers in its application of high-speed machine tools, foreign well-known enterprises such as DMG, Ex-cell-O, Ingersoll, CINCI ATI, GROB, MATEC, MAZAK, FANUC, SODICK have rolled out the use of linear motor centers of the high-speed and high precision.
HIWIN linear products as the world leader in the ball screw and linear slide after success in recent years on its own R & D and production of a linear motor, and in the field of high-speed and high precision good performance.
HIWIN below the main reference of the company's advanced high-speed silent SUPER S series screw-type (DN value of 220,000) and the linear motor HIWIN several major features in some of the more so, for the relevant industry to provide a reference.
Accuracy:
Precision linear motor drive mechanism by a simple interpolation to reduce the lag issues, positioning accuracy and reproducibility precision, absolute precision, through the position detection feedback control will be more "rotary servo motor + ball screw" high, and easy to implement.
Linear motor positioning accuracy of up to 0.1μm. "Rotary servo motor + ball screw" up to 2 ~ 5μm, and the requirements of CNC-servo motors - even without coupling gap - thrust bearing - Cooling System - high-precision rolling guide - Nut Block - table closed-loop system as a whole transmission part to lighter, higher precision grating.
To achieve higher stability, "rotary servo motor + ball screw" to take dual-axis drive, linear motor is a high-heat components, the cold to take strong measures to achieve the same end, the linear motor will pay a higher price .
Price comparison:
Linear motor prices to much higher prices, which is restricted by linear motor of the reasons for wider application.
Speed comparison:
Speed linear motor with a considerable advantage, linear motor speed of 300m/min, acceleration reached 10g; ball screw speed of 120m/min, acceleration is 1.5g. Speed and acceleration from the contrast, the linear motor has a considerable advantage, and the linear motor in the successful resolution of fever after the speed will improve on that level, and "rotary servo motor + ball screw" in the speed limit has been difficult to further increase more.
Because of the dynamic response from the movement of inertia and the gap as well as institutional issues such as the complexity of linear motor also has an absolute advantage.
Speed control on the linear motor because of its fast response, wide speed range, you can start to achieve the highest instantaneous speed, high-speed run-time and can stop quickly. Speed range up to 1:10000.
Comparison of energy consumption:
Linear motors provide the same torque in the power consumption at the time of the "rotating servo motor + ball screw" more than doubled, "rotary servo motor + ball screw" is energy saving, by type power transmission components, linear motor control system reliability by stability, a great influence on the perimeter to take effective protective measures and the magnetic traps, rolling off a strong magnetic field on the impact of rail and the absorption of iron magnetic dust.
Following this example to make it easier for us to know the linear motor and the "rotating servo motor + ball screw" a number of characteristics:
Japan, a company high-speed gantry type machining center. X, Y-axis linear motor drive using V = 120m/min. Why does the company "spin servo motor + ball screw (HIWIN SUPER S series)"? SUPER S Although the DN as the value has gone through a screw from the traditional 70000-150000 to 220000 of the acceleration process, but because of the weakness of pure mechanical transmission, the line speed, acceleration, increased range of travel is always limited . Φ40 × 20mm if selected product is vmax = 110m/min, due to the high speed nmax = 5500r/min trip by the critical speed range Nc constraints obviously not too long.
If the large lead Φ40 × 40mm products, while Vmax = 220m/min, which obviously can not meet the high positioning accuracy of occasions. DN values to achieve 220,000 reflected from one aspect of HIWIN design, manufacturing standards. If we choose Φ40 × 20 (double) mm product, in the n ≈ 4000 ~ 5000r/min, V = 80 ~ 100m/min state use, its safety, reliability, service life can be higher than expected. In fact so far, in the high-speed high-precision CNC machine cut gold (CNC forming machine tools other than) the speed is still V ≥ 120m/min using SUPER S Series driver did not see a successful example. In fact, "rotary servo motor + ball screw" the best applications are: the requirements V = 40 ~ 100m/min, acceleration of 0.8 ~ 1.5 (2.0) g, the accuracy of more than P3-class mid-range high-speed CNC equipment and some high-end number of control equipment.
Application of comparison:
In fact, the linear motor and the "rotating servo motor + ball screw" Despite the way the two drivers have their own advantages, but there are also its Achilles heel. Both have their own CNC machine tools on the scope of application of the best.
Linear motor drive CNC equipment in the following areas of unique advantages: high-speed, ultra high-speed, high acceleration and large-volume production, will require a location more than the movement, speed and direction of the frequent changes in the size of the occasion. For example, the automobile industry and IT industry, production lines, sophisticated manufacturing mold.
Large, long journey of high speed machining centers, aerospace manufacturing industry in light alloy, thin-walled, metal removal rate of the overall component "hollowing" processing. Such as the United States CINCI ATI's "Hyper Mach" Machining Center (46m); Japan MAZAK's "HYPERSONIC 1400L ultra-high-speed machining center.
High dynamic performance, low-speed and high-speed mobility with the time, the dynamics of a highly sensitive precision positioning. For example, Sodick, represented a new generation of high-performance CNC EDM, CNC ultra-precision machine tools, a new generation of CPC crankshaft grinders, cam grinders, CNC lathes and other non-circular.
Light load, rapid special CNC equipment. DMG Germany, for instance, the "DML80 Fine Cutting" laser engraving, drilling machine, Belgium LVD's "AXEL3015S" laser cutting machine, MAZAK the "Hyper Cear510" high-speed laser processing machine.
Germany DMG production all kinds of companies known for high-performance CNC equipment in its feed system servo linear motor used in earlier, but also a high rate of adoption (after models in the machine marked "Linear"), the company's two drive configurations are three types:
All configuration of the axis of linear motor drive "rapid-type" CNC equipment. For example: DMC85V Linear, DMC75V Linear, DMC105V Linear, DMC60H Linear, DMC80H Linear and DML80-Fine Cutting machines such as laser processing.
Mixed-driven. For example: DMF500 Linear dynamic large-scale vertical machining center column in the X axis (trip 5m) with linear motor, V = 100m/min; and in Y, Z axis is the "rotating ball screw servo motor +", V = 60m/min.
All configuration of the coordinate axis "rotary servo motor + ball screw" and "strong-type" processing center. For example: DMC63H high-speed horizontal machining center, V = 80m/min, acceleration of 1g, positioning accuracy of 0.008mm. In addition, DMC80H and DMC100H, DMC125H (duo BLOCK), as well as such DMC60T.
The two drivers in Germany at the same time the use of DMG was also stating that they have their own advantages. Linear motor is much room for improvement, the future of linear motor technologies become more mature, and production up and costs come down, the application will be more extensive, but saving energy, green manufacturing perspective, as well as to consider the characteristics of the two structures "rotary servo motor + ball screw" drive still has its broad market space. Will become a high-speed linear motor (ultra-high-speed), high-end CNC equipment in the mainstream at the same time drive, "rotary servo motor + ball screw" will continue to maintain its mid-range high-speed CNC equipment in the mainstream.
在网上翻译的
随着直接驱动技术的发展，直线电机与传统的“旋转伺服电机+滚珠丝杠”的驱动方式的对比引起业界的关注。
1845年英国人就已经发明了直线电动机，但当时的直线电动机气隙过大导致效率很低，无法应用。19世纪70年代科尔摩根也推出过，但因成本高效率低限制了它的发展。直到20世纪70年代以后，直线电机才逐步发展并应用于一些特殊领域，20世纪90年代直线电机开始应用于机械制造业，现在世界一些技术先进的加工中心厂家开始在其高速机床上应用，国外知名企业例如DMG、Ex-cell-O、Ingersoll、CINCI ATI、GROB、MATEC、MAZAK、FANUC、SODICK都陆续推出使用直线电机的高速高精加工中心。
HIWIN做为世界线性产品的领导者，在滚珠丝杠和线性滑轨方面取得成功后，于近几年自行研发和生产了直线电机，并且在高速高精领域取得不错的业绩。
下面主要参考HIWIN公司的先进的高速静音式丝杠 SUPER S 系列（DN值达22万）和HIWIN的直线电机在几个主要特性上做一些比较，为相关业者提供一个参考。
精度比较：
精度方面直线电机因传动机构简单减少了插补滞后的问题，定位精度、重现精度、绝对精度，通过位置检测反馈控制都会较“旋转伺服电机+滚珠丝杠”高，且容易实现。
直线电机定位精度可达0.1μm。“旋转伺服电机+滚珠丝杠”最高达到2~5μm，且要求CNC-伺服电机-无隙连轴器-止推轴承-冷却系统-高精度滚动导轨-螺母座-工作台闭环整个系统的传动部分要轻量化，光栅精度要高。
若想达到较高平稳性，“旋转伺服电机+滚珠丝杠”要采取双轴驱动，直线电机是高发热部件，需采取强冷措施，要达到相同目的，直线电机则要付出更大的代价。
价格比较：
价格方面直线电机的价格要高出很多，这也是限制直线电机被更广泛应用的原因。
速度比较：
速度方面直线电机具有相当大的优势，直线电机速度达到300m/min，加速度达到10g；滚珠丝杠速度为120m/min，加速度为1.5g。从速度上和加速度的对比上，直线电机具有相当大的优势，而且直线电机在成功解决发热问题后速度还会进一步提高，而“旋转伺服电机+滚珠丝杠”在速度上却受到限制很难再提高较多。
从动态响应上因为运动惯量和间隙以及机构复杂性等问题直线电机也占有绝对的优势。
速度控制上直线电机因其响应快，调速范围更宽，可以实现启动瞬间达到最高转速，高速运行时又能迅速停止。调速范围可达到1：10000。
能耗比较：
直线电机在提供同样转矩时的能耗是“旋转伺服电机+滚珠丝杠”一倍以上，“旋转伺服电机+滚珠丝杠”属于节能、增力型传动部件，直线电机可靠性受控制系统稳定性影响，对周边的影响很大必须采取有效隔磁与防护措施，隔断强磁场对滚动导轨的影响和对铁屑磁尘的吸附。
通过以下这个例子更容易使大家了解直线电机和“旋转伺服电机+滚珠丝杠”的一些特点：
日本某公司超高速龙门式加工中心。X、Y轴采用直线电动机驱动V=120m/min。该公司为何不应用“旋转伺服电机+滚珠丝杠(HIWIN SUPER S 系列）”？因为SUPER S虽然DN值已经历了从传统丝杠7万到15万再到22万的提速进程，但由于存在纯机械传动的软肋，其线速度、加速度、行程范围的增加总是有限的。若选用Φ40×20mm的产品，则vmax=110m/min，因nmax=5500r/min转速很高，行程范围受临界转速Nc的制约显然不可能太长。
若采用大导程Φ40×40mm产品，则Vmax=220m/min，这显然又不能满足定位精度高的场合。能达到DN值22万从一个侧面反映了HIWIN的设计、制造水准。如果我们选择Φ40×20(双头)mm产品，在n≈4000~5000r/min，V=80～100m/min状态下使用，其安全性、可靠性、工作寿命均可高于预期值。事实上到目前为止，在高速高精CNC金切机床中(CNC成形机床除外)速度V≥120m/min仍采用SUPER S系列驱动的成功范例未见到。实际上“旋转伺服电机+滚珠丝杠”的最佳应用场合是：要求V=40~100m/min，加速度0.8~1.5(2.0)g，精度P3级以上的中档高速数控装备和部分高档数控装备。
应用比较：
事实上，直线电机和“旋转伺服电机+滚珠丝杠”两种驱动方式尽管各有优势，但也有自身的软肋。两者在数控机床上都有各自最佳的适用范围。
直线电机驱动在以下数控装备领域具有得天独厚的优势：高速、超高速、高加速度和生产批量大、要求定位的运动多、速度大小和方向频繁变化的场合。例如汽车产业和IT产业的生产线，精密、复杂模具的制造。
大型、超长行程高速加工中心，航空航天制造业中轻合金、薄壁、金属去除率大的整体构件“镂空”加工。例如美国CINCI ATI公司的“Hyper Mach”加工中心(46m)；日本MAZAK公司的“HYPERSONIC 1400L超高速加工中心。
要求高动态特性、低速和高速时的随动性、高灵敏的动态精密定位。例如，以Sodick为代表的新一代高性能CNC电加工机床、CNC超精密机床、新一代CPC曲轴磨床、凸轮磨床、CNC非圆车床等。
轻载、快速特种CNC装备。例如德国DMG的“DML80 Fine Cutting”激光雕刻、打孔机，比利时LVD公司的“AXEL3015S”激光切割机，MAZAK的“Hyper Cear510”高速激光加工机等。
德国DMG公司以批量生产各类高性能数控装备著称，在其伺服进给系统中采用直线电机较早，而且采用率也是很高的(均在机床型号后标注“Linear”)，该公司对两种驱动方式的配置有三种类型：
各坐标轴全部配置直线电机驱动的“快速型”数控装备。例如：DMC85V Linear、DMC75V Linear、DMC105V Linear、DMC60H Linear、DMC80H Linear以及DML80-Fine Cutting激光加工机等。
混合驱动型。例如：DMF500 Linear动柱式大型立式加工中心，在X轴(行程5m)配直线电机，V=100m/min；而在Y、Z轴则采用“旋转伺服电机+滚珠丝杠”，V=60m/min。
各坐标轴全部配置“旋转伺服电机+滚珠丝杠”的“强力型”加工中心。例如：DMC63H高速卧式加工中心，V=80m/min，加速度1g，定位精度0.008mm。此外还有DMC80H和DMC100H、DMC125H (duo BLOCK)以及DMC60T等。
两种驱动方式在德国DMG公司被同时运用也说明他们具有各自的优势。直线电机的提升空间很大，未来直线电机的技术更加成熟了、产量上去了、成本下降了，应用也会更加广泛，但从节能降耗、绿色制造的角度思考，以及两种结构自身特点考虑“旋转伺服电机+滚珠丝杠”驱动仍有其广阔的市场空间。直线电机将成为高速(超高速)、高档数控装备中的主流驱动方式的同时，“旋转伺服电机+滚珠丝杠”依然会继续保持其在中档高速数控装备中的主流地位。
原文地址
http://www.winnermotor.com/Article/238.html