Sudden shock loads and excessive vibration may not be pleasant, but they are typical of many industrial settings. To help your designs stand up to the rigors of harsh environments, consider the following tips and tools.
Sensors detect damaging vibration
The V-Sensor detects damaging vibration levels that occur during automated processes. Sensors are connected to devices such as linear modules, rotary actuators, grippers, and other components. In addition, the sensing units can signal when an industrial shock absorber is nearing the end of its lifecycle, preventing expensive repairs, maintenance, and downtime. V-Sensors are available in PNP, NPN, and analog versions and include various installation adapters. Securing clamps in several diameters are also available.
Ace Controls Inc.
Contact springs handle shock, vibration
Miniature bellows contact springs ensure reliable electrical connection in applications where tolerance buildup, vibration, and thermal expansion are present. Spring flexibility minimizes shock and vibration in dynamic applications. Force requirements of 0.04 oz. per 0.001 in. of travel are available, in diameters from 0.020 to 0.245 in. Springs are made of electrodeposited nickel alloy and gold plated to ASTM B 488-01 to enhance conductivity. Rated for maximum current of 4 amps, they can be used to 260° F. Springs offer low dc resistance with a minimum of insertion loss and feature a nonporous, seamless design.
Linear-position sensors withstand high vibration
Temposonics R and G-Series linear-position sensors have been redesigned to double their prior vibration resistance of 15 g. They survive impact forces of 100 g and vibration forces to 30 g, significantly increasing longevity in high-vibration applications, such as those in the wood industry. R-Series sensors offer linearity down to ±20 µm or better, resolution of 1 µm, and repeatability within 0.001%. G-Series sensors feature analog or digital outputs and enhanced diagnostics. Sensors use non-contact, magnetostrictive technology, which eliminates wear.
MTS Systems Corp.
Encoder stands up to severe shock and vibration
The harsh-duty Acuro AR62 absolute encoder delivers true 16-bit multi-turn resolution. Rather than using batteries and gears, the new design relies on pulse-wire technology while keeping a slim profile for space-constrained applications. When a rotating magnet passes by the pulse-wire, it creates a short burst of electrical energy that can be counted and stored in memory. The design can withstand severe shock and vibration up to 200 g. Installed height is 32 mm; operating temperatures range from -40° to 100° C.
Power supply features passive motor brake
Newly released 8B0P passive power supply modules offer a new type of central power supply for ACOPOSmulti drive systems. Designed for main input voltages from 3x 380 to 3x 500 Vac, the modules provide continuous power output of 8 or 16 kW; a peak power rating of 24 or 48 kW is useful in dynamic applications. Modules also feature a passive motor brake, which can be used to prevent hanging loads from dropping in an uncontrolled manner if power is lost on the drive system. The brake is engaged if the mechanical clamping system fails.
B&R Industrial Automation Corp.
Air Actuators withstand coal dust and vibration - The interior of a coal pulverizer is one of the harshest industrial environments around, as coal dust and vibrations tax materials and components. However, FTL Seals Technology, Leeds, England, recently discovered that air actuators are able to withstand the difficult pulverizer conditions. Figure 1
FTL manufactures pressure cylinders, which press the pulverizer's grinding gears against the material to be ground. These cylinders ensure that grinding pressure remains steady, and also balance out abrasion on the grinding balls. Until recently, these pressure cylinders had been fitted with traditional metal cylinders using hydraulically actuated pistons. Average service life was three months before failure.
Air actuators from ContiTech Air Spring Systems, Montvale, N.J., show much better longevity. These nitrogen-operated pneumatic actuators ensure the correct grinding pressure in coal pulverizers and greatly reduce the toll on equipment. They also function oil-free and without sliding gaskets, for less environmental impact and no maintenance. Channeled air generates force, as in traditional pneumatic cylinders; stroke is output with plain compressed air or with compressed air containing oil or other gaseous media like nitrogen. In low-pressure areas, hydraulic media such as water and glycol can also be used. Because they function without mechanical parts, air actuators do not wear; they also resist dirt, dust, granulated material, sludge, and even many chemicals. Figure 2
The expected service life of FTL's new pressure cylinders equipped with ContiTech's air actuators is 10 times longer than the old steel cylinders. In one early application, a coal-fired power station in South Africa, they've lasted more than five years; the air actuators are now used in coal pulverizers in England, Mexico, Holland, and India as well. For more information, visit www.contitech-usa.com