When it comes to the hazards of heat, water, dust, humidity, shock, and vibration, designs need solid protection. Check out some of the latest components with built-in body armor.
PC handles harsh environments
The newly released Panel PC 725 is an IP65-protected HMI for use directly on machinery. With installation on a support arm, the PC permits flexible mounting and ergonomic operation, even in tight spaces. Equipped with an Intel Atom N270 processor and 15-in. touchscreen display, the fan-free 725 handles standard applications, such as SCADA systems; all components requiring special cooling, such as processor and chipset, are positioned so that heat is distributed directly above the housing. Two Ethernet interfaces, two USB 2.0 interfaces, and one serial interface simplify communication.
B&R Industrial Automation Corp.
Adhesive resists high temps and thermal shock
Formulated for structural applications in extreme environments with temperatures from -80° to 425° F, Master Bond Supreme 33 resists thermal cycling, thermal shock, and impact. This two-component epoxy offers high structural bond strength to a variety of substrates including metals, glass, ceramics, wood, rubbers, and many plastics. Supreme 33 also resists chemicals (including water, oil, and many organic solvents) and cures at room temperature in 48 to 72 hours. It produces bonds with shear strength of more than 2,500 psi and tensile shear strength greater than 7,500 psi.
Master Bond Inc.
Rotary position sensors sealed to IP69 K
IPX Series rotary position sensors with unlimited mechanical movement feature a 79-mm diameter housing size, IP69 K rating, and repeatability to 0.002% over measurement ranges up to 350°. TX2 Series sensors are available from stock in single and fully redundant second-channel versions and feature an operating life of more than 100 million movements. The TX2 series operates in temperatures of -40° to 120° C, as well as in the presence of high humidity, dust, shock, and vibration.
Novotechnik U.S. Inc.
Encoders and inclinometers handle harsh settings
OPTOCODE absolute rotary encoders combine accurate measurement with heavy-duty packaging, suitable for use in harsh environments. Shaft seals and electrical connections are rated to IP67; the plastic code disk withstands shock loads to 100 g and vibrations to 20 g. Suited for use in harsh outdoor conditions, ACCELENS inclinometers feature a DeviceNet electronic interface that allows easy communication. A polyurethane enclosure provides dust and moisture resistance to IP68.
CONEXPO Booth H-31913
Stainless steel gearbox suits washdown conditions
The alpha SG stainless steel gearbox is designed for washdown and food-grade environments. It features a stainless steel housing, shaft, and fasteners, uses NSF H1 food-grade lubricant, and includes corrosion-resistant rotary shaft seals. Applications include food packaging and processing, pharmaceutical manufacturing, and clean room settings. The SG is available in sizes 095 and 130.
Belt drive powers ocean-crossing pedal boat
Two brave young engineers from the U.K. are planning to pedal across the Atlantic Ocean later this year to raise money for charity. Mark Byass, a 23-year-old design engineer, is the boat's designer and crewman. Serving as second crewman and project manager is Mike Sayer, 26, a mechanical engineer. Both have participated in charitable athletic events, so it was no surprise when a friend suggested paddleboating across the English Channel to raise money for charity. Deeming that idea too risky, the pair instead founded the Torpedalo Project, to design a sturdier boat themselves.
The engineers need the boat to withstand a harsh 3,000-mile ocean crossing, so they enlisted a team of experts in the fields of boat design, fiber usage, ergonomics, and hydrodynamics to create a vessel that is strong, fast, comfortable, and safe. Focus quickly shifted to the drive: The initial design included two belt drives with a 90° gearbox to transmit the rotational power of the pedaling motion to the propeller. However, the team soon realized that the gearbox added weight to the boat. After extensive research, they contacted Gates Corp., Denver, for technical assistance with belt-based power transmission.
Dan Parsons, a product application engineer at Gates, began working with Ivo Nikolov, the project's drivetrain engineer. Ivo's initial drawings called for a two-stage drive using a 20-mm wide synchronous belt with an 8-mm tooth pitch. The first stage included a 2:1 speed ratio to take the 85 rpm pedal speed and 0.2 kW of power up to 170 rpm, then a second 2:1 speed stage to take the speed up to 340 rpm and transmit that power down to the propeller.
After reviewing Ivo's design, Dan recommended a narrower belt for both stages — a 12-mm wide PowerGrip GT2 synchronous belt. The first stage includes a 112-tooth driveR sprocket and 28-tooth driveN sprocket (4:1 ratio). The second stage 1:1 ratio drive delivers the increased speed to the propeller using a 26-tooth sprocket at either end, with a 90° twist to eliminate the need for the 90° gearbox.
GT2 belts are made with an EPDM compound highly resistant to seawater, and fiberglass tensile cord. What's more, the belt drive weighs 20% less than the shaft and gearbox design. Efficiency also matters in a human-powered boat: Each stage of the synchronous belt drives is about 98% efficient, for a total estimated drive system efficiency of 96%. In contrast, the belt-and-gearbox system's efficiency was only 92 to 94%.
Torpedalo sea trials will begin this year. In December, the team will participate in the Woodvale Challenge Atlantic Rowing Race 2011, crossing from La Gomera in the Canary Islands to English Harbour in Antigua. Visit torpedalo.com or gates.com/ptdesign for more information.