When patients have a medical exam or procedure that involves x-ray machines, mammography units, or robotic surgery equipment, the last thing they want to hear is grinding gear noise. Noisy or vibrating motion systems are off-putting for patients and can compromise their comfort during an already stressful medical test. Not only that, motion chatter in the drives that move imaging equipment can also produce fuzzy images that aren’t suitable for diagnostic purposes.
Medical machines and imaging equipment require motion system components that are smooth and quiet. Thermoplastic gears can greatly reduce noise and absorb shock and vibration for critical applications such as mammography units and robotic surgery devices.
Power-Core™ gears, for example, combine the company’s proprietary polymer gear material with a metal core. The knurled shape of the metal core ensures a molecular and mechanical bond between metal and the polyamide, allowing the transmission of the full torque found on the keyway, machined into the metal core. This provides a unique balance of properties that make them well suited to medical equipment applications. The polyamide gears have tension-free, homogeneously crystalline structure, achieved through a unique casting process. The shapes are made from laurolactam resin that come in a variety of sizes of rods, tubes, rods with cast-in metal cores, and plates.
In addition to absorbing shock and vibration, compared to metals, these gears reduce noise by up to 6 db, making them an ideal for point-of-care (POC) equipment. The polymer gears are suitable for x-ray equipment, mammography machines, and other imaging systems. The gears eliminate motion chatter, which can compromise image quality in diagnostic tests. And, because the gears use a stainless steel, nonmagnetic core, they are a safe option for magnetic resonance imaging (MRI) machines.
In one dental x-ray machine application, engineers designed a gear that improved the image quality. In addition to providing precise control over the gear’s mesh engagement and backlash, the polymer gear eliminated vibration, maintaining high image quality over time. Because the gears successfully eliminated fuzzy imaging due to motion chatter, the dentists were able to better diagnose and treat patients. For motion system applications that require rollers or cam followers, rollers with polymer bearing surfaces offer a high-performance alternative to traditional metal components. When used as wheels for moving patient platforms, these polymer cam followers provide patients with quiet, vibration-free comfort when moving in and out of MRI equipment.
Unlike metal gears, polymer gears don’t require lubrication, which helps eliminate any potential contamination caused by stray lubricants or metal particulates. Moreover, the material has a low coefficient of friction, translating into higher torque transmission efficiency and allowing designers to select smaller drive motors. The gears resist corrosion and commonly used sterilization chemicals, and they meet out-gassing specifications for laboratory equipment applications that involve vacuum operation.
In many instances — for example, in robotic surgery equipment — inertia is a factor when designing the gear train. Polymer gears are seven times lighter than steel, significantly reducing inertia. A variety of types are available, including bevel gears, helical gears, and worm gears. Because the polymer gears absorb shock and eliminate motion chatter, they are ideal for any application that must retain superior imaging quality.
This article was written by Georg Bartosch, President of Intech Power-Core, Closter, NJ. For more information, visit here .