Product category:
Electric Linear Actuators
News Release from: Power Jacks | Subject: Rolaram linear actuators
Edited by the Engineeringtalk Editorial
Team on 19 April 2004
Powerful solution for linear motion
The Rolaram linear actuator range provides a powerful yet flexible linear motion solution for applications where historically hydraulic or pneumatic solutions were used.
The Rolaram linear actuator range provides a powerful yet flexible linear motion solution for applications where historically hydraulic or pneumatic solutions were used Rolaram linear actuators are designed to satisfy medium- to high-duty actuation applications with 5 to 400kN loads at speeds of up to 7000mm/min as standard
Higher speeds are available as special designs.
From the beginning design of the Rolaram actuators was based around two key building blocks the "actuation unit" and the "drive unit".
Together these units were designed and selected to meet the product performance criteria for load, speed and duty.
The building blocks specified would also have to be compact for their performance rating and be able to offer key mounting, drive and feedback configurations.
The actuation unit is based around a basic lead screw assembly.
To meet the performance range two types are used: a high quality ball screw and nut for medium-duty applications and a roller screw and nut assembly for medium- to high-duty applications.
The roller screw design is essential to meet the high duty aspect while keeping the unit compact and providing the customer with a practical life rating for the unit.
Roller screws in general have higher dynamic load carrying capability than ball screws for a given working envelope.
The roller screw assembly in the Rolaram is Power Jacks' own Spiracon design.
The Spiracon design consists of a multistart screw with an involute thread form and a number of planetary rollers with annular grooves, which engage with the screw.
The rolling action results in a high efficiency mechanism, while the line contact and hardened and ground construction achieves a high dynamic load carrying capacity along with almost no axial backlash or wear.
The lead screw assembly is packaged inside a ram arrangement with internal and external guides and seals to provide a sturdy enclosure.
At the drive end of this assembly is a thrust housing which carries the load from the lead screw to a mounting that allows the unit to be secured to the surrounding structure.
The "drive unit" which is attached to the "actuation unit" provides the rotary motion, which the lead screw converts to linear motion.
The "drive unit" is either a helical or bevel gearbox that allows the motor to be mounted either parallel, inline or at right angles to the actuation unit.
This allows the actuator to fit into most application spaces without special modifications.
The mounting options for the units are equally varied and flexible and include the classic trunnion to clevis and double clevis arrangements.
As each actuator will require a varying level of motion control for each application the units have the capability to have a wide array of feedback devices fitted.
These include encoders (incremental and absolute), limit switches (mechanical or proximity sensors) and clutches.
Since their initial design, the actuators have undergone extensive tests both in-house and in industrial applications throughout the world.
The results have been successful even when operated to the extreme with some units operating on a continuous cycle basis 24 hours a day and others operating in harsh environments. Request a free brochure from Power Jacks ...
• Power Jacks: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
Search the Pro-Talk network of sites
