A roller screw’s application will dictate whether the shaft or nut should rotate. In either case, the type of nut selected depends on the load and how the assembly will move and actuate the system. There are three major types of roller screw nuts: single, split, and double. Single nuts are the most common configuration […]
Ball + lead + roller screws
How to select the right roller screw size
Roller screw systems typically have smaller footprints and more compact designs than their hydraulic counterparts. One motivation to replace hydraulics with roller screws is to reduce bulky and auxiliary equipment and its associated maintenance without compromising performance. Roller screw shafts come in a variety of diameters and load capacities. Some are 3.5 mm in diameter with […]
Lead-screw assemblies from igus for automotive applications
igus’ dryspin lead-screw assemblies are now available as a single-source solution for the automotive industry. In today’s vehicles, advanced linear motion components play a critical role in providing convenience and safety to drivers. Lead-screw assemblies are used extensively wherever automotive parts need to be opened, closed, lifted, or lowered. Typical uses include seats, doors, sunroofs, […]
What is a high helix (high lead) screw?
Ball and lead screws are specified by the diameter of the screw shaft and the lead (or, in some cases, pitch) of the screw thread. The lead, which specifies how far the nut travels for each revolution of the screw, is created by the thread, or helix, that wraps around the screw shaft. If the […]
How to calculate duty cycle and what it means for machine life
Determining the life of a linear system that uses balls or rollers is relatively straightforward, thanks to the L10 bearing life equation, which gives life in meters of travel (for linear bearings) or revolutions (for screws). And for plain bearings and lead screws, manufacturers typically use the bearing’s PV value and operating conditions to provide an […]
Screw drives see new uses in robotics, other applications
Some of the surest, time-tested methods of linear actuation are screw drives. Whether lead- or ball- or roller screws, screw actuation remains a large part of the linear actuation equation, thanks to their reliability, accuracy, and relative simplicity of operation. Recently screw drive developments have included advances in materials as well as manufacturing methods leading […]
Part 2 of 2: Electric actuators as an alternative to hydraulic cylinders
Here we offer some tips for converting a fluid-power-driven axis to electrical actuation. By Ryan Klemetson • Business Development Manager | Tolomatic, Inc. As explained in Part 1 of this article series on motioncontroltips.com, hydraulic systems offer long service life, but they’re not as efficient as electric systems. Electric systems also provide precise position, velocity, […]
What is an inverted roller screw and how does it work?
Roller screws are often thought of as the standard planetary design, but several variations exist, including differential, recirculating, and inverted versions. Each design offers unique benefits in performance capabilities — load capacity, torque, and positioning — but the inverted roller screw’s primary strength is its ability to be easily integrated into actuators and other subassemblies. Recall that […]
Linear bearing basics: Surface roughness, texture, and finish
One of the factors to consider when selecting shafts for linear bearings is surface roughness, which describes the microscopic asperities, or peaks, and valleys present on a material’s surface. But surface roughness is an important specification for all types of linear guides and screws — whether plain or recirculating, round shaft or profiled rail, ball […]
Screw handedness: When do you need a left-handed screw?
Just like people, ball and lead screws can be either right-handed or left-handed. But in screw terminology, handedness indicates the direction in which the nut moves relative to the direction of the screw’s rotation. By far the most common version is the right-handed screw, in which the nut moves toward you when the screw is […]
