The design and manufacture of customised linear positioning systems on short lead times is key to LinTech’s success. This California-based company offers an exceptionally wide range of options enabling its customers to create the optimum system for the job.
To compensate for misalignment between the motor shaft and screw (or belt) drive shaft extension LinTech’s product programme includes the choice of three different coupling types. The middle option is especially apposite to LinTech’s policy as it too can be tailored to suit the specific needs of the application. This flexibility is provided by the Oldham Series couplings, which are manufactured and supplied by Huco Dynatork.
This British manufacturer of precision drive products was the first to employ the sliding coupling designed by the 19th century engineer, John Oldham, for locomotive applications. It introduced a plastic torque disc to achieve zero backlash and applied the principle to modern precision drives. The Oldham coupling has been central to the Huco product programme since the mid ‘80s.
The 3-part sliding disc Oldham coupling is typically recommended by LinTech for applications that involve high acceleration and the starting and stopping of high inertial loads. Naturally it is supplied in a choice of diameter and length sizes and with bore diameters to accommodate various NEMA and metric motor shafts. However, it is the choice of hub styles and disc materials associated with this coupling that has particular appeal for LinTech. The hubs determine the method of installation and shaft attachment and the discs, the quality of motion.
The Oldham is precision engineered throughout and comprises two hubs with inward facing tenons. These engage with matching slots spaced at 90° in a central lightweight torque disc. As the coupling rotates, the disc compensates for any parallel shaft offset by sliding the commensurate distance along each tenon in turn. A hard, low friction facing on the working surface guarantees long, trouble-free operation.
Quality of motion is a function of the carefully controlled relationship between the tenons and the torque disc. The disc is precision moulded from high grade engineering polymers and, being easily replaced at low cost, is the sacrificial element in the drive train. A choice of torque discs is available including those resistant to radiation and heat. If severely overloaded the torque disc will break, acting as a mechanical fuse, thereby protecting associated equipment from damage. A replacement torque disc quickly restores the drive without the need to dismantle the drive system.
“We like the flexibility of mixing and matching different bore hubs to create a total coupling for an application,” explains Gary Wester, Vice President of Sales. “And we favour standard nylon torque disc that provides a nice degree of system damping between the motor output vibrations and the input shaft on our positioning slide.”
This ability to fine-tune the component to the exact performance requirements of the application has earned LinTech a substantial customer base. Its systems are used in a broad variety of general automation applications but particularly for precise positioning in the medical, automotive and packaging sectors.
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