May 14, 2013 Volume 09 Issue 18

Mechanical News & Products

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SOLIDWORKS: FeatureManager tips for assemblies

Discover tools to make your SOLIDWORKS assembly Feature-Manager design tree display easier to view and use. Learn options to limit the amount of information in each component listing, combine multiple instances of a component into a single listing, and separate fasteners mates into a new folder. Lots more tips on the SOLIDWORKS YouTube channel.
View the video.


Top die casting design tips: Xometry

Optimize your die casting project's manufac-turability with these 23 top design tips from Xometry. Ensure your work is cost effective too, so you can hit the ground running and have the highest chance of success. Tips include: fillets and radii, wall thicknesses, ribs and metal savers, holes and windows, parting lines, finishes, and more.
Read the Xometry article.


8 top ways to wreck your coupling-driven system

Engineers at Ruland Manufacturing Co. have compiled the eight best ways to consistently sabotage or damage your coupling-driven system -- and how to avoid these pitfalls in the future. Misunderstanding performance criteria such as misalignment, torque, or rpm can be all it takes to cause a critical and costly failure.
Read the full article.


New washer tech for leak-free automotive sealing

Trelleborg Sealing Solutions has just launched the Rubore® Washer, a unique solution offering virtually leak-free sealing beneath screwheads to safeguard critical systems in vehicles, especially electric ones.
Read the full article.


How Reell electric wrap spring clutches work

Electric wrap spring clutches are ideally suited for critical timing applications requiring consistent, repeatable engagement and disengagement performance. Wrap spring technology used in Reell clutches provides the capability to transmit a large amount of torque in a small size -- package sizes smaller than other clutch technologies such as friction disk, tooth, or magnetic particle. Reell's technology has very positive engagement characteristics and also limits the effects of wear.
Read this informative Reell article.


New 'breathable' rupture disk tech provides overpressure and vacuum relief

To increase equipment safety and reliability, a new rupture disk technology activates at a set burst pressure, but it can also "breathe" to relieve minor pressure fluctuations. The patent-pending, dual-function device from BS&B Safety Systems is ideal for use on low-pressure vessels that are susceptible to ambient temperature changes.
Read the full article.


Engineer's Toolbox: 9 considerations for specifying a slewing ring bearing

In applications that require a bearing to support a structure while it rotates (e.g., cranes, radar, tank turrets), premature bearing failure can put people and equipment at risk. While slewing ring bearings have proven themselves countless times in such applications, designers must consider many factors when specifying them. According to engineers at Kaydon, the bearing's support structure, mounting (including bolt strength, tensioning, and hole patterns), installation, and even storage are all factors in a bearing's success or failure.
Read the full article.


ClampDisk micro fastener is new alternative for automotive and consumer electronics

Designed as a unique alternative in assemblies for the automotive and consumer electronics markets, the ClampDisk Press-on Fastener is a new offering from PennEngineering that delivers a fast, simple way to achieve sheet-to-sheet clamped fastening while replacing the use of standard screws, nuts, and adhesives. The most common challenges that can be eliminated or reduced by using ClampDisk include over installation, cross threading, stripped screw heads, broken screws, and damaged product. This fastener can be removed easily with a sharp-edged tool.
Learn more and see how ClampDisk works.


New nylon constant torque hinge

Southco has expanded its line of E6 Constant Torque Hinges with a compact, nylon version designed for small applications. The newest addition to the company's E6 50 Constant Torque Position Control Hinge series measures 45 mm with a torque range of 4 to 16 in./lb and is 65% lighter compared to the standard E6 50 Hinge. It provides constant resistance throughout the entire range of motion, enabling users to easily position doors, display screens, and other mounted components and hold them securely at any desired angle.
Learn more.


What injection molding material do I use?

How do you decide what type of plastic to use for your next injection molding project? Xometry can help you narrow your choices. Discover the different strengths and applications for materials that could be ideal for your application by learning about the most common plastic injection molding materials in detail.
Read this detailed Xometry article.


What are carbon composite bellows springs?

The Carbon Composite Bellows Spring (CCBS) from MW Components is a system of carbon fiber elements that combine to work as a high-performance, lightweight, and design-flexible compression spring meant to replace coil springs or metallic Belleville disc springs. A functional spring is made from several individual elements paired and joined to make a stack. The stack spring rate is determined by the number of elements, the base rate of each element, and their series or parallel orientation in the stack. Applications include motorsports, aerospace, and high-performance activities.
Learn more.


Conductive Brush Ring overcomes current leakage in EV powertrains

SKF's new Conductive Brush Ring paves the way to greater reliability and longer life in high-performance electric vehicle powertrain systems. Using pure carbon fiber bristles, it provides a reliable electrical connection between an EV eAxle rotor shaft and its housing. When used in combination with SKF Hybrid ceramic ball bearings, it helps to alleviate parasitic current effects that can lead to premature failure in bearings and other components. Available in different configurations for wet (oil-lubricated) motor designs -- and soon for dry (sealed) applications.
Learn more.


hyperMILL 2024 CAD/CAM software suite

OPEN MIND Technologies has introduced its latest hyperMILL 2024 CAD/CAM software suite, which includes a range of powerful enhancements to its core toolpath capabilities, as well as new functionality for increased NC programming efficiency in applications ranging from 2.5D machining to 5-axis milling. New and enhanced capabilities include: Optimized Deep Hole Drilling, a new algorithm for 3- and 5-axis Rest Machining, an enhanced path layout for the 3D Plane Machining cycle, better error detection, and much more.
Learn more.


One-part epoxy changes from red to clear under UV

Master Bond UV15RCL is a low-viscosity, cationic-type UV-curing system with a special color-changing feature. The red material changes to clear once exposed to UV light, indicating that there is UV light access across the adhesive material. Although this change in color from red to clear does not indicate a full cure, it does confirm that the UV light has reached the polymer. This epoxy is an excellent electrical insulator. UV15RCL adheres well to metals, glass, ceramics, and many plastics, including acrylics and polycarbonates.
Learn more.


SPIROL Press-N-Lok™ Pin for plastic housings

The Press-N-Lok™ Pin was designed to permanently retain two plastic components to each other. As the pin is inserted, the plastic backfills into the area around the two opposing barbs, resulting in maximum retention. Assembly time is quicker, and it requires lower assembly equipment costs compared to screws and adhesives -- just Press-N-Lok™!
Learn more about the new Press-N-Lok™ Pin.


Drive-thru tent proves to be simpler, cheaper way to test heavy-duty truck emissions

University of Denver scientists have developed a new highway emissions test for trucks that is far more reliable and less costly than the present test. If used, it could save the trucking industry millions of dollars and ensure that truck emissions are measured accurately.

"We have invented a drive-thru Streamlined Heavy-duty Emissions Test (SHED) which measures all the pollutants of importance in mass emissions units -- the current government standard," says Donald Stedman, John Evans Professor in the Department of Chemistry and Biochemistry at Denver. "The test allows the truck to simply accelerate in its normal way with its normal load."

Developed by researchers at the University of Denver, the new SHED test for truck emissions is more accurate and less costly.

 

 

The SHED technique measures realistic truck exhaust emissions in 20 sec or less -- and the truck does not even have to stop. The system basically places a 50-ft long tent roof over the roadway, which captures some of the exhaust. "Under the roof," says Stedman, "is a perforated sampling tube with suction provided by an in-line blower. The perforations are designed to accelerate the air sample down the tube at about the same speed as the truck accelerates under the roof."

The result is a measurement that is closely comparable to federal emissions standards.

That is an upgrade to existing testing practices in two ways. First, the current method tests only for how much or little light (opacity) a truck's exhaust lets in. This actually has little correlation with the government standard for pollution, which is measured in units of smoke mass. Oxides of nitrogen, an important part of diesel exhaust, are not measured at all.

Second, the test now in place is time-consuming, which drives up transportation costs. The truck must be pulled over and stopped with the engine idling. The tester mounts an opacity monitor on the hot exhaust pipe, then has the driver floor the accelerator to allow the motor to go to its maximum RPM. "This is something that never occurs under normal circumstances," Stedman says.

The SHED testing technique has undergone two successful tests. The first was done in collaboration with researchers at Texas A&M University. The second took place in Vancouver, British Columbia. In the latter test, more than 1,000 heavy-duty truck emissions were measured. The results were presented in April at the Coordinating Research Council On-Road Mobile Source Emissions Conference.

Stedman says that practical applications of the SHED test include "improved estimates of the impact of truck emissions on air quality and fast emission screening at selected drive-thru locations, such as weigh stations, transit terminals, and border crossings."

The SHED test could also help The United States fulfill an unmet part of the North American Free Trade Agreement (NAFTA), he notes. NAFTA allows trucks from Mexico to deliver directly to destinations in the U.S. But in practice that doesn't happen, in part because of fears that the Mexican trucks might be more polluting than the better-regulated U.S. fleet.

"Border crossing loads now are emptied from one truck and refilled into another," says Stedman, "significantly increasing the cost and time of transportation."

Earlier work by Stedman and his University of Denver colleagues resulted in a technique that enabled an emissions test for cars that, by using remote sensing, could be carried out in about 1 sec as the car drove by. That resulted in on-road emission monitoring being made a part of the 1990 U.S. Clean Air Act Amendments, although that mandate has been more or less ignored, except in Colorado. In Colorado, almost 300,000 drivers each year get a postcard from Air Care Colorado stating that they have passed their emission test by means of remote sensing during the course of their normal driving and thus do not have to report for their biennial emission test.

Stedman is hopeful that his new truck test will take off nationwide as successfully as his car test has been accepted in Colorado.

Source: University of Denver/Newswise

Published May 2013

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