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.
With major product releases coming from big names like Sony, Microsoft, and Samsung, and big investments by companies like Facebook, 2015 could be the year that virtual reality (VR) and augmented reality (AR) finally pop. Here's take a look back at some of the technologies that got us here (for better and worse).
Good engineering designs are those that work in the real world; bad designs are those that don’t. If we agree to set our egos aside and let the real world be our guide, we can resolve nearly any disagreement.
The Industrial Internet of Things is bringing a previously reluctant process industry into the wireless fold. The ability to connect smart sensors to the Internet has spiked the demand for wireless devices in process manufacturing, according to the new study from ARC Advisory Group.
If you’re developing an embedded monitoring and control application, then you’ll want to take note of the upcoming Design News Continuing Education Center class, “Embedded Development Using Microchip Microcontrollers and the CCS C Compiler."
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.