Trading fiber reinforced plastic for aluminum, new couplings from R+W deliver lower moments of inertia compared to metal versions of similar capacities. That translates to faster accelerating—or smaller motors and gears for achieving it. After choosing a lightweight material for their hubs, R+W engineers further reduced the coupling’s inertia by locating a greater proportion of the hub mass close to center. They also lightened it with holes, which also permits even cooling.
The TX1 Series 60 coupling weighs 6.3 oz. and has a moment of inertia of 0.03 x 10-3 kg m2. Compare that to the same series of the aluminum type, the EK2/60, which weighs 12.3 oz and has a moment of inertia of 0.09 x 10-3 kg m2.
The new design costs about half of what a traditional aluminum servo insert coupling would. It operates within a slightly narrower temperature range than standard couplings, -20 to 100C instead of -30 to 120C. It’s capable of speeds to 10,000 rpm.
To answer any concern over the material’s durability, R+W subjected a TX1 60 Series model to accelerated life testing that consisted of 40 million load reversals at its 60 Nm load rating. No change in the hub structure was seen. Also, the company subjected it to torques of 3 to 4 times rated capacity and found the motor shaft key deforming but not either hub. The manufacturer expects the keys and the polyurethane insert to be the most likely elements to fatigue.
High rigidity was an important goal for the coupling’s designers, as it is intended to operate without backlash. Static torsional stiffness for the thermoplastic coupling is 9750 Nm/rad and dynamic torsional stiffness is 11,900 Nm/rad.
TX1 couplings are available for torques of 2 Nm to 660 Nm (18 to 5841 lbs/in) and for bore sizes from 8mm to 45mm (0.375 to 1.75in).
Fiber reinforced plastic in the hubs of this jaw coupling lighten it and reduce its moment of inertia.
Lithium-ion battery prices will drop rapidly over the next 10 years, setting the stage for plug-in vehicles to reach 5%-10% of total automotive sales by the mid- to late-2020s, according to a new study.
Two researchers from Cornell University have won a $100,000 grant from NASA to continue work to develop an energy-harvesting robotic eel the space agency aims to use to explore oceans on one of the moons of Jupiter.
Is the factory smarter than it used to be? From recent buzzwords, you’d think we’ve entered a new dimension in industrial plants, where robots run all physical functions wirelessly and humans do little more than program ever more capable robotics. Some of that is actually true, but it’s been true for a while.
A recent Design News-exclusive study proves that engineering professionals are at the very forefront of this push into the future and making direct financial, performance, and value impact on their organizations by being personally involved or final decision-makers on automation solution and component choices.
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