Screw assemblies that use rollers as the load-carrying element come in several varieties, with the most common being the traditional planetary roller screw, which provides high load capacities and very high rigidity, capable of outperforming ball screw and hydraulic actuators in some heavy-duty applications. But another type of roller screw — the recirculating roller screw — […]
Linear drives (all)
How to account for ball and lead screw inertia during system design
When sizing a motion system with a ball or lead screw drive, the first step is to determine the screw diameter and lead that can meet the application requirements for thrust force, speed, and compressive (buckling) loads. Once the screw diameter and lead are determined, the next step is to choose a motor that can […]
Ewellix Planetary roller screw lands on Mars
Ewellix has developed and manufactured a planetary roller screw that recently landed on Mars as part of NASA’s Mars 2020 Perseverance Rover Mission. Ewellix engineers in Armada, Michigan, worked in collaboration with NASA’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology to develop a roller screw component for the Perseverance Rover that would […]
Ball and lead screw drunkenness: What is it and when does it matter?
Unlike ball screws, which follow industry standards such as DIN ISO 3408, JIS B1192-1997, or ANSI-B5.48 for accuracy classifications, there are no accuracy standards for lead screws. Instead, many lead screw manufacturers have loosely adopted two of the most common ball screw lead accuracy specifications: lead deviation per 300 mm and lead deviation per revolution. Lead deviation […]
The difference between rack-pinion module and diametral pitch
Gear sizes are typically specified by one of two designations: Module or diametral pitch. While both specifications define the size of the gear teeth, module and diametral pitch are calculated differently, with module (sometimes referred to as metric pitch) being the metric sizing standard and diametrical pitch being the Imperial (inch) sizing method. Standard […]
More on the performance of roller screws
Knowing the differences between the several kinds of roller screws can help determine the best fit for an application. By Michael Boudreau, P.Eng. • Application Engineering Manager | Rollvis S.A. Planetary roller screws — also called satellite roller screws — have long been the primary choice for applications that involve heavier loads and higher forces […]
Top 10 considerations when applying rack and pinion systems
Rack and pinion systems are excellent electromechanical devices uniquely suited for achieving a linear or rotary motion solution mostly unattainable with other technologies. The typical system is made up of long straight rack (or linear gear) with teeth on one surface, a matching pinion (or circular gear), and a method for driving one or the […]
Ride the wave of electrification: Off-highway designs with linear actuators
The transition of mobile machinery and off-highway equipment away from fossil fuels may be a long-term goal, but electrification is already delivering real benefits in the sector. By Tarek Bugaighis • Ewellix Is the era of the internal combustion engine coming to end? Under pressure to reduce harmful emissions, the automotive industry is already gearing […]
Rails, screw assemblies boast 20,000 km travel without relubrication
The BSHP ball rail systems and BASA ball screw assemblies from Bosch Rexroth now achieve lubrication intervals that are up to four times longer. In more and more applications, they can even be used maintenance-free over the entire service life of a component. As a result, low-maintenance or maintenance-free linear motion technology minimizes operating costs […]
When should you use a bronze lead screw nut?
Lead screw manufacturers offer nuts in a wide array of materials, including various plastics and grades of bronze. And while plastics garner a lot of attention for their versatility and range of suitable applications, lead screw nuts made of bronze are especially well-suited for applications with high loads or extremely high (or low) temperatures. Plastic […]
