Power Transmission
New lubricant-free ball bearing materials for better wear resistance
L
ubricant and maintenance-free, xiros polymer ball bearings can endure temperatures of up to
150°C, are highly corrosion-resistant, can be washed and cleaned, are non-magnetic and are lightweight. According to Matthew Aldridge, of
igus UK, xiros ball bearings provide an economic alternative for many applications where the use of conventional metallic ball bearings is problematic. These applications are varied, ranging from all kinds of medical equipment, pumps and measurement machines, through to transport and conveying technology – particularly in the industrial sectors of chemicals, food, laboratories and packaging. “These are applications where the focus
is not on maximum load and speed, but on other features such as chemical resistance or submerged components,” explains Aldridge. “In such applications, lubricants
can be washed out of the metallic, sealed and permanently lubricated ball bearings, so that corrosion becomes a significant problem.” In addition to the lack of
lubricant and corrosion, weight reduction, the avoidance of magnetism, very good friction coefficients and longer service life are further benefits of the use of xiros plastic ball bearings. The general purpose ball bearing
Fig. 2. xirodur B180 - radial deep-grooved ball bearings for absorbing axial forces, lubricant-free ball transfer unit for conveying sensitive materials.
material xirodur B180, low-price chemical resistant xirodur C160 and high-temperature xirodur A500 are now complemented with the addition of xirodur F180 and xirodur D180 materials. xirodur F180 is a conductive polymer
that provides electrostatic discharge (ESD) protection. Bearings from this material can be used permanently at temperatures of up to 80°C and are therefore well-suited to a variety of applications, including those found in the semiconductor, paper processing, textile and glass industries. The second new material is xirodur D180,
Fig. 1. xirodur D180 - extremely wear- resistant for high rotational speeds.
which is four times more wear-resistant than the general purpose material xirodur B180. The inner and outer ring of the xiros D180 bearing is made of the new high- performance material, the cage is made of PA, the balls either of glass or stainless steel and operating temperature is 80°C. “Our laboratory testing of the xiros
D180 bearings indicates that they can be 72 times more wear-resistant than ball bearings made of PEEK,” says Aldridge. “We also tested ball bearings made of PE, PP, PA and POM – all of these gave a significantly shorter service life. Ongoing material optimisation, along with a comprehensive series of tests, has enabled us to increase the service lives of our xiros plastic ball bearings by a factor of 42 since the birth of xiros in 2007.” The range of dimensions has also been
increased; igus now offers more than a hundred sizes, shapes and styles. These range from radial and axial bearings, multi-purpose bearings for both linear and rotational movements, ball transfer units, pedestal bearings and flange bearings through to ball bearings with dust shields. “The standard range is supplemented by tailor-made, customer-specific solutions, which are becoming increasingly important,” adds Aldridge. ●
For more information, visit
www.igus.co.uk H
Linear actuator range is adaptable and flexible The H series actuator design is based
eason Technology’s new H series linear actuators are aimed at OEM positioning applications
in automated manufacturing and test equipment. With seven selectable travel ranges
from 25mm to 300mm, commercial or precision grade positioning options and a choice of integrated or separate stepper motor/drive combinations, the H series actuator features a modular and smart design that provides a flexible mounting system for XY, XYZ and Gantry systems as well as telescopically arranged linear axes for extended Z-axis travel.
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on an extruded profile housing with T-slots that facilitate multi-axis actuator mounting, optional limit switches and customer fixtures. A fixed cover plate provides additional protection and is arranged to allow unrestricted carriage travel. The carriage, which may be moving or fixed, is supported by a sturdy linear guide bearing for maximum rigidity and a choice of commercial or precision grade leadscrews are available to suit application performance and budget. A flexible coupling and anti-backlash nut arrangement guarantees high stiffness with
repeatability stated at 0.2 microns for the commercial grade option and 0.1 microns for the precision grade version. Extremely compact multi-axis configuration is possible using Heason Technology’s recommended DSMS series stepper motors which have integrated microstepping drives for much reduced system wiring. With up to 51,200 steps/rev the maximum positioning resolution is 2 microns with traverse speeds to 170 mm/sec. ●
For more information, visit
www.heason.com
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