Chris Ras, Product Development Manager at Dexter Magnetic Technologies, describes the drive system as “consisting of two single sided timing pulleys configured into two independent drive sections, each of which utilizes two single-sided timing belts.“ During tests at a customer’s plant, the faster of the two compact belt drives required frequent and precise tensioning to eliminate belt stretching and excessive wear.
Ras, in exploring a gear design as an alternative to the belt drive, contacted Tody Mihov, our Engineering Manager at Intech Corporation, to discuss how self-lubricating plastic Intech gears might work into his design. The application offered limited space, featured both high torque and reversing torque, and the gears needed to be retrofitted into existing equipment on location at the customer’s facility.
Upon reviewing load data using a proprietary gear calculation developed by Intech in conjunction with a leading university, Mihov determined that the Intech gear would work. He then decided to maximize the load carrying capacity of the Power-Core™ gears by applying an innovative Intech developed plus/plus gear mesh modification to the gear train. With the addition of two stainless steel drive gears, an Intech Power-Core™ idler gear that has an integral stainless steel core and a proprietary backlash-free plastic gear design, the desired smooth manipulator motion was assured. In addition, a special idler gear shaft was designed to provide an easy, field-ready retrofit.
An in-house test was constructed to determine how the Intech solution performed relative to visible wear patterns and drive efficiency. As per his expectation, Ras determined that drive efficiency increased by a full 15%! He reasoned that this was achieved in part by eliminating the radial stresses that belt tensioning transferred to the bearing. With the Intech Power-Core™ gears running stress-free, the only force transmitting onto the mating gear teeth was the torque, which traveled on a precision-machined pitch line.
With the retrofit Intech gear replacement system in place to manage reliability of the rotary axis, Dexter Magnetic Technologies has gained even greater industry attention.
Self-lubricating, Anti-backlash Gear Solution
Intech Power-Core Thermoplastics Engineering Blog
Intech engineers are frequently asked for help to determine worm gear size, design parameters and to make wear-life projections using our proprietary gear calculations. As a result of these calculations, Intech Power-Core™ composite worm gears are chosen to replace industry-standard bronze gears in demanding operations to increase transmission efficiency with quieter, longer-wearing performance.
Intech Power-Core Worm Gears
Power-Core material does not require special grade oil or frequent oil changes and the composite material does not generate abrasive particles which become suspended in the oil as a contaminant that contributes to wear. The tough, self-lubricating properties of the composite gear material enable Intech Power-Core worm drives to consistently outlast conventional bronze worm gears.
We completed a 1,000 hour test that compared gear performance between the Intech Power-Core gear and a case-hardened ground steel worm gear, and the results confirmed the capacity of Power-Core material to absorb shock load and vibrations. Test data showed an average noise reduction of 6 dB, with up to an 8% increase in gear transmission efficiency and no wear was detected on the 6.5 PD Power-Core worm gear.
In applications such as conveyors for glass washing or light load semi-conductor manufacturing machinery, the Intech Power-Core worm gears run with only light grease lubrication, or completely dry. Even in high torque applications that result in friction, the self-lubricating Power-Core worm gear can run for extended periods without lubrication.
The mating worm shaft can be made of conventional materials utilizing standard manufacturing methods. The low-maintenance Power-Core composite worm gears use readily available machine oil to lubricate the gear box, instead of more expensive specialized synthetic oil that is usually recommended for bronze worm gears.
So our engineers at Intech have developed a proprietary gear durability calculation software program that enables us to precisely predict the operating life of the Power-Core™ gears that they design and build.
Parameters used in the gear calculation are based on data obtained at a leading university during a decade-long study. The calculation includes both tooth root stress and contact safety stress under a wide range of temperatures and rotational speeds.
The result: a calculation that accurately predicts performance, wear reliability, and the expected gear life for the given operating conditions, even before the gear is machined.
The calculation is also used to properly size a gear for any application, making the use of lubrication-free gears possible.