A family of Swiss-developed elastomeric elements for tension, suspension, oscillation, and vibration devices are now available for U.S. and Mexican OEM designers via a firm formed by Rosta AG of Switzerland and the U.S. coupling manufacturer Lovejoy. The new company Rosta LLC, headquartered in Downers Grove, IL claims that the elements can be used to replace self-opening and -closing hinges, oscillating bearings, chain/belt tensioners, or shock-absorbing mount-ings that are dependant upon metal springs or pneumatic/hydraulic cylinders. With no metal-to-metal contact, the new elements eliminate the need for lubrication, avoid failures caused by moisture and rust, and diminish the noise associated with moving metal parts.
The elements are self-contained, torsion-spring units in which four elastomeric inserts are fitted into the corner spaces created when a square metal shaft is positioned within a square metal outer housing and displaced 45°. These inserts are press-fitted between the shaft and housing, essentially suspending the shaft in the housing to create a moveable joint that combines bearing, spring, and vibration-damping functions.
When
either the housing or shaft is clamped in place, the other half can rotate 30°
clockwise and counterclockwise for a total oscillation of 60°. Greater
angles of oscillation can be achieved by combining the elements so that two
housing and shaft units working in series can rotate up to 60° for a total
oscillation arc of 120°. As the angle of rotation for the outer housing
increases, the torque applied against the square inner shaft by the elastomeric
inserts also increases for a greater damping effect.
The Rosta LLC tension/vibration elements are available in several
elastomeric materials and can be used to replace spring and
bearing combinations, reducing component and assembly
costs and simplifying product design.
The elastomeric inserts in the Rosta LLC elements dampen vibration through hysteresis; the higher the angle of oscillation, the greater the amount of physical energy that is converted into heat energy. The external metal housing and internal metal shaft provide the sinking necessary to prevent the heat from building up and adversely affecting the elastomer. Because the elastomer is always in compression between shaft and housing, it suffers very little shearing or degradation.
The elements are available in several elastomeric materials that can extend temperature tolerance up to 120°C (250°F) and resist oil degradation. Neoprene tensioning elements, for example, can withstand temperatures up to 82°C (180°F) while adding high resistance of chemicals and oil-bath environments.
ExxonMobil Lubricants & Petroleum Specialties Co. announced at MINExpo International 2000 that it will be offering a lubrication management program to simplify the tasks of maintenance planners, managers, and supervisors. Slated to debut in January, the Mobil Monitor Lubrication Management System (LMS) integrates lubrication task routing and scheduling with preventive maintenance functions to automate and facilitate the planning and control of a company's entire lubrication program. It will work closely with the other two components of the Mobil Monitor suite of services: laboratory testing and oil analysis software.
Mobil Monitor LMS is designed to simplify lubrication tracking, scheduling, and routing as well as parts inventory management for all types of site equipment. It is capable of generating a wide range of customizable reports covering lubricant inventory, personnel efficiency, root-cause failure, and work history. The system also offers detailed lube charts for a single piece of equipment, a department, or an entire facility.
"Mobil Monitor LMS will make the manager's job easier by putting knowledge at his or her fingertips," said Sally Edge, ExxonMobil's Lubrication Services Program Advisor. "Managers no longer have to make potentially costly guesses or assumptions because the screen tells you at a glance which jobs are due or past due. And it makes things much more efficient by automating tasks that used to be done manually."
The system was developed with input from maintenance professionals, lubrication
engineers, and industry consultants.
Some of its key features include:
"Mobil Monitor LMS provides an easy-to-use, flexible lubrication management tracking and reporting system that helps extend equipment life, minimize production costs, and improve bottom-line results," said Edge.
