Lead Screw Mechanism - Types , Advantages, Applications

Table of Contents

What Is Lead Screw?

铅螺杆，也称为动力螺钉，是螺纹杆或杆，其将旋转运动转化为线性运动。当涉及将电机的旋转运动转换为线性运动时，存在许多不同的方式完成这项任务。通常在运动控制世界中，不同方法和技术之间的战斗可以变得非常有争议。然而，通常，最好记住，某些技术比其他技术更好，并且一如既往，成本和产品寿命也是确定在给定应用中使用的技术的关键因素。

铅螺钉使用线的螺旋角度将旋转运动转换为线性运动。引线螺钉的性能严重依赖于螺母和螺钉之间的摩擦系数，这又取决于用于螺母的材料和拧紧。铅螺钉通常使用由内部润滑的塑料或轴承级青铜制成的螺母。塑料螺母通常在不锈钢螺钉上行进，而青铜螺母经常在碳钢螺钉上运行。使用轴承级青铜螺母时，不锈钢螺钉是一种选择。

铅印件以与其他螺纹形式相同的方式制造（它们可以被滚动，切割或接地）。

A lead screw is sometimes used with a split nut also called half nut which allows the nut to be disengaged from the threads and moved axially, independently of the screw’s rotation, when needed (such as in single-point threading on a manual lathe).

Types Of Lead Screws are:

Power screws are classified by the geometry of their thread. V-threads are less suitable for leadscrews than others such as ACME because they have more friction between the threads. Their threads are designed to induce this friction to keep the fastener from loosening. Leadscrews, on the other hand, are designed to minimize friction. Therefore, in most commercial and industrial use, V-threads are avoided for leadscrew use. Nevertheless, V-threads are sometimes successfully used as leadscrews, for example on micro lathes and micro mills.

Square head

Square threads are named after their square geometry. They are the most efficient, having the least friction, so they are often used for screws that carry high power. But they are also the most difficult to machine and are thus the most expensive.

Acme thread

Acme threads have a 29° thread angle, which is easier to machine than square threads. They are not as efficient as square threads, due to the increased friction induced by the thread angle. ACME Threads are generally also stronger than square threads due to their trapezoidal thread profile, which provides greater load-bearing capabilities.

支撑线

支撑线s are of a triangular shape. These are used where the load force on the screw is only applied in one direction. They are as efficient as square threads in these applications but are easier to manufacture.

Advantages and disadvantages of Lead screw Mechanism :

铅螺丝的优点是：

大负载承载能力
袖珍的
Simple to design
易于制造;不需要专门的机械
Large mechanical advantage
Precise and accurate linear motion
Smooth, quiet, and low maintenance
Minimal number of parts
Most are self-locking

铅螺杆机构的缺点：

The disadvantages are that most are not very efficient. Due to the low efficiency they cannot be used in continuous power transmission applications. They also have a high degree of friction on the threads, which can wear the threads out quickly. For square threads, the nut must be replaced; for trapezoidal threads, a split nut may be used to compensate for the wear.