Traditional roller screws — sometimes referred to as planetary roller screws — can produce axial forces comparable to hydraulic cylinders, with the speed and precision capabilities of ball screws, at a price point that falls between the two. A variation of the planetary roller screw — referred to as a differential roller screw — reduces some […]
Linear drives (all)
Synchronous belt materials: What’s the difference between urethane and neoprene?
Synchronous belts for linear motion applications — such as general transport conveyors or high-speed gantry positioning — are available in a wide range of materials suitable for virtually any application. The most common synchronous belt materials are neoprene and polyurethane, but specialty materials and backing surfaces are also available to address requirements such as temperature extremes, […]
Acme or trapezoidal? What’s the difference between lead screw designs?
In power transmission applications, there are two primary types of screw drives: those that use recirculating balls or rollers, for applications that require high rigidity, excellent positioning accuracy, and high duty cycles, and those that rely on sliding contact, for applications that require corrosion-resistance, self-locking operation, and customizable nut designs. The second category — screw […]
What’s the best timing belt tooth profile for high-speed applications?
Synchronous belts (also referred to as timing belts) are used in a wide range of power transmission and transport applications that require good positioning accuracy. Tensile cords molded into the belt material help eliminate or minimize belt stretch, and positive engagement between the teeth of the belt and the pulley make synchronous belts less likely […]
What causes synchronous belt noise and how can it be reduced?
Synchronous belts are common in motion systems, providing smoother operation and better high-speed performance than chains and lacking the problems of slipping and stretching that can plague V-belts in precision applications. But one downfall of synchronous, or toothed, belts is the noise they produce. Although quieter than a chain drive, a synchronous belt can still generate noise […]
How can lead screw backlash be reduced?
Backlash is an inherent property of lead screw assemblies due to the sliding motion between the screw and the nut. For some applications, a certain amount of backlash, or “play,” can be tolerated, but applications such as positioning, dispensing, or assembly often require a level of precision and repeatability that can’t be achieved if backlash […]
What’s the difference between ball screw critical speed and characteristic speed?
Ball screw drives incorporate two primary moving components: the rotating screw shaft and the nut that traverses the screw. (The radial bearings that support the screw shaft play a minor role for the purposes of this discussion.) This means that to accurately determine the maximum allowable speed of a ball screw assembly, there are two […]
What is a follower nut, and what role does it play in lead screw operation?
Although the idea of a “follower nut” may seem to indicate that the nut serves a passive role in lead screw operation, it actually plays an important part in monitoring the condition and life of the screw assembly. The wear characteristics of a lead screw nut make the expected service life of the assembly difficult […]
When to use linear bearings and ball nuts with ceramic balls
Ball nut preload: What effect does it have on bearing life?
Ball nut preload offers several benefits to screw assemblies, but the most common reason for using a preloaded ball nut is to reduce axial play, or backlash, caused by clearance between the screw and nut raceways. Reducing this axial play does two things. It improves the repeatability of the screw assembly — meaning the assembly […]
