线性执行器介绍（中英文）

什么是线性执行器？

What is a Linear Actuator?

“线性执行器”一词涵盖了广泛的产品。线性执行器是一种机械装置，可将能量（来自空气、电力或液体的动力）转换为直线运动，与传统电动机的圆周运动形成对比。它还可用于施加力。运动类型包括：阻挡、夹紧、弹出、提升、下降、推动或拉动。

The term "linear actuator" covers a broad range of products. A linear actuator is a mechanical device that converts energy (power from air, electricity or liquid) to create motion in a straight line, contrasted with circular motion of a conventional electric motor. It can also be used to apply a force. Types of motion include: blocking, clamping, ejecting, lifting, descending, pushing or pulling.

线性执行器的基本设计

Basic Design of a Linear Actuator

如前所述，“线性执行器”一词涵盖了广泛的产品；每个子类别的外观和操作方式都不同。在大多数线性执行器设计中，其基本操作原理是倾斜平面。简单地说，丝杠的螺纹充当连续的斜坡，允许在长距离上使用较小的旋转力来实现短距离内大负载的移动。

As mentioned earlier, the term "linear actuator" covers a broad range of products; each sub-category looks and operates differently. In the majority of linear actuator designs, the basic principle of operation is that of an inclined plane. Simply stated, the threads of a lead screw act as a continuous ramp that allows a small rotational force to be used over a long distance to accomplish movement of a large load over a short distance.

线性执行器如何工作？

How Does a Linear Actuator Work?

所有线性执行器都依赖于外部非线性力来驱动某种活塞来回移动。但是，不同类型的线性执行器的工作方式不同。“活塞”是指通过或逆着流体、气压或电流移动的滑动件。它通常由一个短圆柱体组成，安装在圆柱形容器内，并沿着该容器来回移动。例如：在蒸汽机中，运动是由蒸汽产生的，而泵将运动传递给流体。

All linear actuators depend on an external, non-linear force to drive some kind of a piston back and forth. However, different types of linear actuators work in different ways. A ‘piston’ is defined as a sliding piece which is moved by or against fluid, air pressure, or electricity. It usually consists of a short cylinder fitting within a cylindrical vessel along which it moves back and forth. For example: in steam engines, motion is created by steam, and pumps transmit motion to a fluid.

例如，液压泵执行器依靠液压泵压缩和减压活塞的两侧，以推动活塞来回移动。活塞连接到外部轴上，因此轴会随之移动。另一方面，蜡马达线性执行器使用电流熔化蜡块，使其膨胀。当蜡随着电流的变化而膨胀和收缩时，压在蜡上的柱塞会以线性运动来回移动。

Hydraulic pump actuators, for example, depend on a hydraulic pump to compress and decompress the two sides of a piston in order to push it back and forth. The piston is attached to an external shaft, so the shaft moves with it. On the other hand, a wax motor linear actuator uses an electric current to melt a block of wax, causing it to expand. As the wax expands and contracts with varying electrical currents, a plunger that is pressed against it moves back and forth in a linear motion.

线性执行器功率和操作选项：

Linear Actuator Power and Operational Options:

线性执行器驱动力有很多选项：手动机械方法包括虎钳和夹具的丝杠系统，以及手动榨汁机或罐头粉碎机中的杠杆。带有活塞的气缸由压缩空气驱动，用于移动机器的部件。带有活塞的液压缸为铲车、升降机和千斤顶等建筑设备提供巨大的力量和冲程，而短行程气缸则用于制动系统。螺线管线圈是短行程电磁线性执行器，除了锁定和解锁门外，还可以打开和关闭开关和阀门。电磁电机极的线性级数用于有轨电车、自动人行道和物料输送机。还提供独立的线性执行器电机。

There are many options regarding the linear actuator driving force: Manual mechanical methods include the lead screw systems of vises and clamps, and levers found in manual juicers or can crushers. Cylinders with pistons powered by compressed air are used to move parts of machines. Hydraulic cylinders with pistons provide large forces and strokes for construction equipment such as shovels, lifts and jacks, and short throw cylinders for braking systems. Solenoid coils, which are short throw electromagnetic linear actuators, turn switches and valves on and off in addition to locking and unlocking doors. Linear progressions of electromagnetic motor poles are used for trams, people movers, and material conveyors. Self-contained linear actuator motors are also available.

线性执行器有什么用途？

What is a Linear Actuator Used For?

线性执行器用于工业自动化和机械、机床、计算机外围设备（如磁盘驱动器和打印机）、家庭自动化、包装、装配、电子制造、数据存储、激光加工以及测试和检查。线性执行器通常与电机、阀门、泵、开关、阻尼器一起用于需要线性运动的许多其他地方。线性执行器还用于医学成像和诊断、太阳能、农业、建筑、汽车和机器人应用。

Linear actuators are used in industrial automation and machinery, machine tools, computer peripherals such as disk drives and printers, home automation, packaging, assembly, electronic manufacturing, data storage, laser processing, and test and inspection. Linear actuators are typically used in applications along with motors, valves, pumps, switches, dampers, and in many other places where linear motion is required. Linear actuators are also used for medical imaging and diagnostics, solar, farming, construction, automotive, and robotics applications.

几乎所有需要线性运动的电气设备都使用线性执行器。电钻、泵和其他工业设备通常依靠线性执行器来移动其他物体。线性执行器还用于某些类型的电机，并且经常用于机器人行业，为机器人提供运动技能。事实上，电动机或燃油喷射发动机内的简单活塞使用线性运动，因此可充当线性执行器。

Linear actuators are used in nearly every type of electrical device that requires linear motion. Power drills, pumps, and other industrial appliances often rely on linear actuators to move other objects. Linear actuators are also used in some types of motors, and are often used in the robotics industry to provide robots with motor skills. In fact, a simple piston inside of an electric motor or fuel-injection engine uses linear motion, and therefore, acts as a linear actuator.

线性执行器的基本变体

Basic Variations of Linear Actuators

长期以来，人们已经创建了许多基本线性执行器设计的变体。大多数变体都侧重于提供一般改进，例如更高的机械效率、速度或负载能力。工程界也大力推行线性执行器小型化。一些制造商认为线性执行器越小越好。这并不一定意味着节省成本，相反，这有利于减小线性执行器运动控制系统的整体尺寸和重量。

Many variations of the basic linear actuator design have been created throughout time. Most focus on providing general improvements such as a higher mechanical efficiency, speed, or load capacity. There is also a large engineering movement towards linear actuator miniaturization. It is seen by some manufacturers that the smaller the linear actuator, the better. This does not necessary equate to cost savings, and rather, is desirable for reducing the overall size and weight of a linear actuator motion control system.

• 旋转到线性运动 – 一些线性执行器使用齿形带或滚子传动链的直线部分，在两个滑轮或链轮之间的纵向回路中运行。这种类型的线性执行器系统广泛用于车库门开启器。其他线性执行器还使用标准旋转电动机（例如步进电机、直流有刷电机、直流无刷电机和交流电机），并进行机械转换，用于转向系统或缝纫机中的曲轴，以及许多其他用途。

Rotary to Linear Motion – Some linear actuators use straight sections of a cogged belt or roller drive chain in a lengthwise circuit between two pulleys or sprockets. This type of linear actuator system is widely used in garage door openers. Other linear actuators also use standard rotational electric motors (such as Stepper, DC Brush, DC Brushless and AC motors) with mechanical conversion for steering systems, or crankshafts in sewing machines, and many other uses.

• 专用线性执行器 – 高度专用的线性执行器用于关键应用，例如大型飞机上的液压驱动飞行控制面、需要精确定位到千分之一的超精细加工设备、微型伺服电机和齿形带，以及眼科手术等医疗程序中的微小运动。即使是家用电脑打印机中使用的廉价步进电机驱动线性执行器的分辨率也可以低至单个像素大小。

Specialized Linear Actuators – Highly specialized linear actuators are used in critical applications, such as hydraulically actuated flight control surfaces on large aircraft, in ultra-fine machining equipment requiring precise positioning to tenths of thousandths, as well as tiny servo motors and cog belts, and for minute movements in medical procedures such as eye surgery. Even inexpensive stepper motor-driven linear actuators used in home computer printers have resolution down to single pixel size.

• 运动、位置、速度和力的组合 – 将线性执行器集成到设备中的设计师必须仔细检查其应用，以确定运动、力、位置或速度是否是主要的操作要求，或者应用是否需要所有这些的组合。例如：打印机头倾斜系统必须能够在长行程中精确定位打印头，而制动缸必须通过相对较短的行程对限制其运动的制动盘提供非常大的力。建筑中使用的大型挖掘机上的液压缸必须能够在数英尺的行程中提供数万磅的力，精度达到一两英寸就足够了。电路板组装中使用的电子控制线性执行器以惊人的速度移动，因为微芯片被插入到精确的位置。因此，复杂的线性执行器应用通常会结合连接到可编程机器控制系统的位置、力和速度反馈传感器，以确保线性执行器性能始终如一。

Motion, Position, Velocity, and Force Combinations – Designers integrating linear actuators into equipment must examine their application carefully to determine whether motion, force, position, or velocity is the primary operational requirement, or whether the application requires some combination of all of them. For example: printer head skewing systems must be able to position the heads precisely across a long stroke, while braking cylinders must provide very large forces through relatively short strokes against the brake discs that limit their motion. The hydraulic cylinders on large excavators used in construction must be able to provide tens of thousands of pounds of force over many feet of stroke, with a degree of precision of an inch or two being considered adequate. Electronically controlled linear actuators used in circuit board assembly move at blinding speed as microchips are inserted into precise positions. Therefore, complex linear actuator applications will often incorporate position, force and velocity feedback sensors connected into programmable machine control systems to ensure that linear actuator performance is achieved consistently.

• 机电线性执行器设计 – 大多数机电线性设计都包含导螺杆和导螺杆螺母，而有些则使用滚珠螺杆和滚珠螺母。无论哪种情况，螺杆都可以直接或通过一系列齿轮连接到电机或手动控制旋钮。齿轮通常用于允许以较高 RPM 旋转的较小、较弱的电机减速，以提供在比电机能够直接驱动的更大负载下旋转螺杆所需的扭矩。一般而言，这种方法实际上牺牲了线性执行器的速度，以增加执行器的推力。在某些应用中，使用蜗轮很常见，因为这种方法允许更小的内置尺寸和更大的行程长度。

Electromechanical Linear Actuator Designs – Most electromechanical designs incorporate a lead screw and lead nut, while some use a ball screw and ball nut. In either case, the screw may be connected to a motor or manual control knob either directly or through a series of gears. Gears are typically used to allow a smaller, weaker motor rotating at a higher RPM to be geared down to provide the torque necessary to rotate the screw under a heavier load than the motor would otherwise be capable of driving directly. Generally speaking, this approach effectively sacrifices linear actuator speed in favor of increased actuator thrust. In some applications, the use of a worm gear is common, as this approach allows for a smaller built-in dimension and greater travel length.

移动螺母线性致动器的电机固定在丝杠的一端（可能通过变速箱间接固定）。电机转动丝杠，而丝杠螺母则被限制转动。因此，螺母沿丝杠上下“移动”。

A traveling-nut linear actuator has a motor that stays attached to one end of the lead screw (perhaps indirectly through a gearbox). The motor rotates the lead screw, and the lead nut is restrained from rotating. Therefore, the nut "travels" up and down the lead screw.

外部线性（移动螺母）执行器如何操作？

How do external linear (traveling-nut) actuators operate?

移动式螺杆线性致动器的导螺杆完全穿过电机。在移动式螺杆线性致动器中，电机沿着被限制旋转的导螺杆上下“爬行”。唯一的旋转部件位于电机内部。在某些设计中，从螺杆致动器的外部甚至看不到旋转部件。

A traveling-screw linear actuator has a lead screw that passes entirely through the motor. In a traveling-screw linear actuator, the motor "crawls" up and down a lead screw that is restrained from rotating. The only rotating parts are inside the motor. In some designs, the rotating parts may not even be visible from the outside of the screw actuator.

非固定（移动丝杠）线性执行器操作

Non-captive (traveling-screw) linear actuator operation

一些丝杠有多个“头”。这意味着它们在同一轴上交替有多个螺纹。一种简单的可视化多头丝杠的方法是糖果棒上的多个彩色条纹。多头丝杠在螺距和螺母/丝杠螺纹接触面积之间提供更多的调整能力，这将分别决定（螺纹的）伸展速度和承载能力。

Some lead screws have multiple "starts." This means that they have multiple threads alternating on the same shaft. One simple way to visualize the multiple starts lead screw is the multiple color stripes on a candy cane. Multiple starts lead screws provide for more adjustment capability between thread pitch and the nut/screw thread contact area, which will determine the extension speed and load carrying capacity (of the threads), respectively.

糖果上的多个彩色条纹类似于具有多个头的导螺杆

The multiple color stripes on the candy resemble a lead screw with multiple starts

线性执行器的静态负载能力

Static Load Capacity of Linear Actuators

螺旋式线性执行器可以具有静态负载能力，这意味着当电机停止时，执行器基本上被锁定在原位，可以支撑对执行器进行拉动或推动的负载。线性执行器的制动力随螺纹的角螺距和螺纹的具体设计而变化。

梯形丝杠具有非常高的静态负载能力，而滚珠丝杠的负载能力极低，并且几乎是自由浮动的。一般来说，如果不使用额外的技术，就不可能改变螺旋式线性执行器的静态负载能力。螺旋执行器的螺纹螺距和驱动螺母设计决定了无法动态调整的具体负载能力。

Screw-type linear actuators can have a static load capacity, meaning that when the motor stops, the actuator is essentially locked in place and can support the load that is either pulling or pushing on the actuator. The braking force of the linear actuator varies with the angular pitch of the screw threads and the specific design of the threads.

Acme screws have a very high static load capacity, while ball screws have an extremely low load capacity and are nearly free-floating. Generally speaking, it is not possible to vary the static load capacity of screw-type linear actuators without additional technology. The screw thread pitch and drive nut design of the screw actuator defines the specific load capacity that cannot be dynamically adjusted.

线性执行器的动态负载能力

Dynamic Load Capacity of Linear Actuators

在某些设计中，螺旋式线性执行器使用电磁制动系统来增加动态负载能力，电磁制动系统对旋转驱动螺母施加摩擦力。例如，弹簧可用于将制动片施加到驱动螺母上，在电源关闭时将其固定在原位。当需要移动执行器时，电磁铁会抵消弹簧的作用并释放驱动螺母上的制动力。同样，螺旋式线性执行器可以使用电磁棘轮机构，这样当执行器的电源关闭时，提升负载的驱动系统将锁定在原位。要降低执行器，可使用电磁铁抵消弹簧力并解锁棘轮。

A dynamic load capacity is in some designs added to a screw-type linear actuator using an electromagnetic brake system, which applies friction to the rotating drive nut. For example, a spring may be used to apply brake pads to the drive nut, holding it in position when power is turned off. When the actuator needs to be moved, an electromagnet counteracts the spring and releases the braking force on the drive nut. Similarly, an electromagnetic ratchet mechanism can be used with a screw-type linear actuator so that the drive system lifting a load will lock in position when power to the actuator is turned off. To lower the actuator, an electromagnet is used to counteract the spring force and unlock the ratchet.