The breakaway connectors also feature ITT’s spring probe pin/pad contact system. The contact design utilizes an internal clip mechanism that stays in constant contact with the contact itself, helping to reduce electrical contact resistance. Additionally, the spring probe contact system accommodates misalignment issues, making the contact system much more forgiving.

The spring probe system allows the connector receptacle to house individual touch pad contact areas, providing a highly effective electrical engagement point of contact. Further, the spring probe contact system and touch pads allow for ease of cleanability in the field, where dirt, moisture, mud, sand, and other contaminants may be present. The individual touch pad contacts contain no crevices for contaminants to accumulate.

The Nemesis Series sealed, lightweight, miniature connectors are resistant to salt spray for more than 500 hours, measure less than 15mm in diameter, and have an anti-reflecting coat. Maximum current rating for the Nemesis WT connectors is 3A and voltage rating is 200VAC RMS at sea level. Minimum insulation resistance is 5000MΩ, and maximum contact resistance is 8mΩ. Operating temperature ranges from -40°C to +100°C.  Life span is to 2500 cycles.

The MKJ Series miniature, circular connectors are available with a variety of mounting options for both crimp and PC board contacts, including in-line, jam nut, front mount, square flange mount and flange mount. The connectors are up to 71% lighter and 52% smaller than comparable devices, and feature size 23 pin-and-socket contacts that have the equivalent electrical performance of size 22 contacts. Dielectric withstanding voltage at sea level is 500VAC RMS, 60Hz. Operating temperature ranges from -55°C to +150°C.

Typical pricing for the Nemesis breakaway connectors is approximately $90.00 per mated pair for 1,000 sets. The breakaway connectors will be available in Q2 2010.

www.ittcannon.com

An imperfect coil structure induces an unbalanced geometry and increases sensitivity to the position of the measured conductor within the sensor, or to the proximity of external electric cables. The RT series of sensors overcomes the problem of asymmetry resulting from the discontinuity at the sensor opening, which is inherent in conventional split-core Rogowski coils. LEM engineers have invented a unique magnetic coupling technology that allows a perfect extension of the magnetic flux at the loop opening, which compensates for coil asymmetry.

The thin, light and flexible format of the RT sensors allows them to fit into applications in which traditional current transformers are typically too heavy and bulky, especially when measuring high currents. Their split-core construction allows them to be easily wrapped around the conductor without dismantling cables or shutting down operation. The benchmark accuracy of RT series sensors provides enhanced performance in current and power monitors as well as energy meters.

www.instrumentation.co.za

Stafford Corrosion-Resistant Collars and Couplings are offered in 303 and 316 stainless steel, brass, bronze, and other materials for various power transmission and structural system requirements. Featuring a wide range of sizes and styles, they are suitable for use in pump drive systems, mixing equipment, flow control instruments, and other applications exposed to water, harsh chemicals, solvents, and detergents.

Developed for water treatment, pollution control, pulp and paper, chemical plants and related facilities, Stafford Corrosion-Resistant Collars come in 1-pc, 2-pc and set-screw styles in sizes up to 16″ I.D. and the couplings in 1-pc, 2-pc, and 3-pc styles up to 6″ I.D. All can be modified with special bores, keyways, mounting holes, flats, hinges, threads, and more.

Length adjustability also results from this design, making the EZV reusable in different machine layouts, and easier to install, especially with certain alternate hub designs, like EK7 expanding mandrels and EK6 high strength conical clamp ends. For any size the EZV can also be made with ZAE torsionally rigid bellows couplings, or with integral ES2 mechanical torque limiters.

R+W America
www.rw-america.com

Available with either M12 or M8 connector ports, the new Lumberg Automation modules are designed for ease of installation and plug-and-play startup. In addition, they offer comprehensive diagnostics possibilities, are sealed to IP67 and exhibit high resistance to shock and jarring.

The Lion-Link peripheral I/O system can be used for line topologies of up to 100m in length. The system comprises bus coupling modules for interfacing with higher-level fieldbus systems, including Profibus, Canopen, Devicenet or Ethernet, and protocol-independent I/O modules. A key benefit is that machine manufacturers only need to implement minor hardware modifications when connecting equipment to end customers’ specific communication networks if they use different data transmission protocols.

One of the modules, the 0940 PSL 602 bus coupling module, is designed for controlling electrical drives over Profibus-DP V1. Up to nine 0942 UEM 783 motion drive control modules can be connected to its two Link ports for controlling a maximum of 72 drives.

The motion drive control modules have four outputs that can be configured both for brushless EC and brushed DC, as well as other DC motors. Acceleration, speed and deceleration can be controlled in noncyclical mode.

A third new module is the 0942 UEM 620 I/O Link master module, which provides point-to-point connections for intelligent sensors and actuators by means of the I/O Link protocol. Four ports can be configured as digital inputs/outputs or for communications mode. The module is wired with three-conductor standard cords that can be up to 20m in length. The Profibus bus coupling module enables users to connect up to six master modules. In combination with a Profinet bus coupling module from the Lion-Link family, the I/O Link master module can also be used in Ethernet networks.

The 0940 PSL 603 bus coupling module permits the integration of up to 30 of the 0942 UEM 670 shadow modules in a Profibus network. Serving as inactive secondary components, these modules each provide eight digital I/O connections. They can be activated by means of a ‘hot plug’ function without compromising the higher-level Profibus communication. In this way, lines can also be retrofitted or upgraded when in operation and without the need for additional hardware.

Each of the 0942 UEM 602 and 0942 UEM 612 I/O modules features four digital outputs for an increased output current limiting of 2A per line and a maximum total of 6A. Whereas the 0942 UEM 602 version has standard-type outputs, those of the 0942 UEM 612 version are designed for safety-critical applications up to Performance Level D of EN ISO 13849-1. Amongst others, therefore, this module is also suitable for intrinsically safe actuator control or reliable emergency power-off functions.

The 0941 UNC 601/…M Lion-Link power module is used for decentralised power supplies. It has four ports, two potential circuits and a 10m lead with a conductor gauge of 5×1mm2. This provides for bridging distances of up to 25m without voltage loss, as well as for configuring separate potential groups each with their own fuses.

www.beldenemea.com

The composite material is flexible in one plane and stiff in another plane. It is not prone to fatigue and will perform longer than stainless steel. Custom designs are available with torque ranges from 270 in.-lbs (30 Nm) to 550,000 in.-lbs (63,000 Nm) and with speed ranges from 500 rpm to 15,000 rpm. They are available in custom lengths from 46 in. to 196 in. and with outside hub diameters of 2.25 to 12 in.

www.zero-max.com

Utilizing a special, high stiffness bellows and new, high strength connection method, the BKZ handles an average of 2.6x the traditional torque rating at a given outside diameter, and an average of 2.9x more lateral misalignment, opening up the benefits of precision bellows couplings to a whole new segment of machine design and servo motion control.

Accepting bore diameters ranging from 15 to 60mm and torque ratings from 20 to 1000Nm, the BKZ range is available in 4 sizes, with a variety of materials, finishes and the optional self-opening clamp system. View online at http://www.rw-america.com/bellows_couplings/bellow-coupling-bkz-t.php

R+W America
www.rw-america.com

The RSD series couplings are used to rapidly and easily connect and disconnect the hydraulic lines between a tractor and its various items of equipment (trailer, plough, etc.) without using any tools.

The technology of the RSD coupling allows for a completely safe connection of a male connector, whether pressurized or not, under adverse conditions, such as under a maximum pressure of 250 bar (3626 psi), and withstands a return flow rate that may reach 190 l/min (50.2 gallons/min) and even beyond for a few seconds at a temperature close to 120°C (248°F).

www.victrex.com

In an ideal world, multiple components could be produced in a single piece, or coupled and installed in perfect alignment. However, in the real world, separate components must be brought together and connected on-site.

Couplings are required to transmit rotational forces (torque) between two lengths of shaft, and despite the most rigorous attempts, alignment is never perfect. To maximize the life of components such as bearings and shafts, flexibility must be built in to absorb the residual misalignment that remains after all possible adjustments are made. Proper lubrication of couplings is critical to their performance.

Figure 1. Types of Misalignment

MISALIGNMENT
Misalignment can occur as either an offset or angular displacement on two of the three possible axes (Figure 1). The third axis, in the longitudinal direction, is not commonly measured, though errors in this direction can result in excessive thrust loads in a system. For major installations, such as large compressors, wire alignment methods are used. Smaller applications have traditionally used rim-and-face dial indicator readings to quantify and correct misalignment, though optical laser indicators have grown in popularity due to their ease of use and accuracy.In pace-setting maintenance organizations, efforts are also made to compensate for thermal growth that occurs in equipment during operation. All materials (except water) expand a small amount when heated; the amount by which they do so is governed by the material’s coefficient of thermal expansion and the degree to which it is heated. A machine that is brought into alignment at ambient temperature will creep into a position of misalignment as the machinery materials climb or fall to operating temperature.

Attempts are made to preheat or cool equipment to normal operating conditions before performing alignment checks. Alternatively, calculations of anticipated thermal growth can be used to intentionally misalign the drivetrain at ambient temperature so that it may grow into alignment. Whatever precautions are taken to make alignments as precise as possible, some amount of residual misalignment will inevitably remain. Misalignment forces rigid machine components such as shafts to deflect in order to effectively become aligned. This deflection stresses the components, causes vibrations, and distributes higher and uneven loads on the structures that support these elements, such as bearings. These stresses waste energy and can dramatically reduce equipment life and reliability.

Designed properly, couplings can absorb misalignment forces so that more expensive, critical and sensitive components may be saved. While rotating shafts appear sturdy, the bearings which support them are some of the most sensitive precision components in the drivetrain.

Figure 2. Gear Couplings

TYPES OF COUPLINGS
Coupling designs may be divided into four principal categories, each having several specific designs. Solid and magnetic couplings do not require lubrication, but are included here for completeness. Solid couplings are fundamentally rigid structures that do not compensate for misalignment, but do allow two shafts to be joined for the purpose of transmitting torque. Bolted hubs keyed onto shafts are an example of a machine with magnetic couplings. Magnetic couplings allow shafts not in direct contact to be driven together using powerful permanent or electrical magnets. A sealless magnetic drive pump is a common example.Other coupling types are flexible couplings and fluid couplings. Many flexible couplings use fixed-position flexible metallic, rubber or plastic elements, such as discs or bushings, that rotate with the shafts and absorb misalignment. Designs of this type do not require lubrication. Others such as geared, chain, grid and universal joints do require lubrication for performance and longevity. Fluid couplings include torque converters and torque multipliers. These couplings are filled with lubricating fluids that rely on the fluid to transmit torque.

Figure 3. Chain Couplings

FLEXIBLE COUPLINGS
Gear couplings (Figure 2) compensate for misalignment via the clearance between gear teeth. Shaft-mounted external gear teeth on both shafts mate with internal gear teeth on a housing that contains a lubricant. Other designs mount external teeth on only one shaft, mating with internal teeth mounted to the other shaft. Acceleration or deceleration can result in impacts between gear teeth due to backlash from the clearance being taken up on opposite sides of gear teeth. Misalignment will result in sliding relative motion across mating teeth as they pass through each revolution.Chain couplings (Figure 3) operate similarly to gear couplings. Sprockets on each shaft end are connected by a roller chain. Clearance between components and clearance in mating the chain to the sprockets compensate for the misalignment. Loading is similar to that of geared couplings.

External grid couplings (Figure 4) use a corrugated steel grid that bends to compensate for loading induced by misalignment. Grooved discs attached to the ends of each shaft house the grid, which transmits torque between them. Low-amplitude sliding motion develops between the grid and grooves as the grid deforms under load, widening in some locations and narrowing in others over each revolution.

Universal joints are used for maximum allowable misalignment up to 20 to 30 degrees, depending upon the design. They are used extensively for the drive shafts of vehicles to allow the wheels to move with the suspension system. Universal joints use a four-spindled component called the spider to connect two shafts terminating in yokes or knuckles at right angles (Figure 5). Each of the four spider journals is supported by a bearing or bushing contained in one of the knuckles, which allow articulation.

Figure 4. Grid Coupling

FLEXIBLE COUPLING LUBES
Both lubricating oils and greases can be selected to lubricate flexible couplings. Unless specifically noted by the coupling designer, couplings for the majority of industrial components are grease lubricated. Coupling components are protected primarily by an oil film which bleeds from the grease thickener and seeps into the loading zone.Lubricated flexible couplings require protection from the low-amplitude relative motion that develops between components. Other concerns include centrifugal stress on the lubricant (particularly grease), which causes premature separation of the oil from the thickener, poor oil distribution within the housing and oil leakage from the housing.

The motion’s low amplitude, articulation speed and tendency toward a sliding rather than rolling action inhibits the development of hydrodynamic (full-film) lubrication. Greases made with high-viscosity base oils, anti-scuff (EP) and metal-wetting agents are recommended to overcome the boundary (mixed-film) conditions that often exist in flexible couplings. High oil viscosity also slows the leakage rates.

Centrifugal forces in flexible couplings can be extreme, becoming greater with increased distance from the rotational axis. Even moderately sized couplings can generate forces thousands of times greater than gravity (referred to as Gs). Grease makers put a high priority on formulations that resist premature separation of oil and thickener due to the high G forces.

Figure 5. Universal Joint

FLUID COUPLINGS
Fluid couplings transfer momentum from the input shaft to a fluid and then to the output shaft when transmitting torque. Misalignment is accommodated solely by clearances between the moving parts. The small clearances don’t provide much room for error in alignment. However, it is possible to effectively compensate for shock loading and high-torque starting loads as there is no solid connection between input and output shafts.In fluid couplings, an impeller attached to the input shaft accelerates fluid within the coupling as it spins, much like in a centrifugal pump. This fluid then hits the vanes of the output shaft’s runner, transferring its momentum as the runner accelerates. It will accelerate until it approaches the speed of the input shaft, but will never actually reach it. The difference in speed between the input and output shafts is known as slippage. Of course, frictional and viscous drag must be overcome before the output shaft can rotate. The minimum input speed required for this condition is known as the stall speed. Equipment with large static loads, such as a steam or gas turbine, would use a fluid coupling to minimize the initial stress on the driving shaft.

Shock loads on the input side, such as starting torque, are never created. The speed of the input shaft is never restrained. When the stall speed is exceeded, the output shaft will begin to accelerate, but will do so at a constrained rate due to its moment of inertia (resistance to angular acceleration). Slippage is created as the runner accelerates to the speed of the input, dissipating excess energy through viscous heat generation in the fluid. Output side shock loads will be similarly dissipated, even if the output shaft should completely stall.

Torque converters and multipliers are special applications of fluid couplings that allow the input torque to be modified before transmission. These designs operate fundamentally by the same principles, but are mechanically much more complex.

FLUID COUPLING LUBES
The dissipation of energy that makes fluid couplings so tolerant of shock loading creates the potential for rapid and extreme increases in fluid temperature. The energy dissipated during stall and slip is converted to heat through the viscous shearing of the fluid (fluid internal friction). In extreme applications, the fluid temperature can rise above the normal 200-degree Fahrenheit operating temperature in less than a minute.Oxidation and thermal degradation resistance are important qualities of oil used for fluid couplings because of the potential for drastic temperature increases. Similarly, a high viscosity index (VI) is also useful to prevent severe decreases in operating viscosity at temperature spikes and excessively high operating viscosity at low-temperature conditions.

Low-viscosity fluids are ordinarily used in these applications to reduce the power lost to heat due to fluid friction. Fluid coupling viscosities may fall between 2.5 to 72 centistokes (cSt) at 40 degrees Celsius. For fluid couplings designed to operate at high temperatures, viscosity limits may be given at 100 C.

These fluids must also resist foaming due to the severe agitation caused by the impeller’s movement and its impact upon the runner vanes. Rust-protective properties help preserve the coupling’s metal components. Hydrocarbon-based fluids are superior in this regard to other fluids, but their performance can be improved through rust-inhibiting additives. Seal compatibility is also important for long-life usefulness.

RECOMMENDATIONS
Acceptable life can be expected from any of these devices only if proper maintenance is performed. Lubricant levels and quality must be verified through periodic checks. Additional lubricant may be needed to compensate for leakage. Periodically flush and change the lubricant to remove harmful by-products of lubricant breakdown, to replace oil-depleted grease or to refresh the additive population. Gear couplings require perhaps the most maintenance. Typical relubrication intervals are six months to one year, depending upon application severity and experience.All maintenance tasks must be performed with attention paid to contamination control. The sliding contact suffered by many couplings indicates that abrasive three-body wear caused by particulate contamination could be particularly damaging. Improper removal of solvents used to clean couplings during inspections and flushing operations can lead to significant viscous thinning of the lubricant in operation or detrimental reactions with grease-thickening materials.

Couplings will endure when the demands placed on them are reduced. Consider the first line of defense to be a minimization of shock loading, including hard starts and sudden load reversals. Sometimes operational demands make this impossible. The principal source of loading in coupling systems can be controlled to a great extent, however. Proper alignment is considered a high-priority, precision maintenance functions. Use vibration analysis or thermography during operation to identify couplings that are not in alignment, as even the sturdiest foundations shift over time. Certainly, check for proper alignment whenever intrusive maintenance or repairs are performed on the coupled components.

www.reliableplant.com

Leadership in Engineering

This is the 3rd annual Leadership event announcing the winners in the 2009 Leadership Awards Program. The Design World User Community have cast their votes and we are pleased to announce the winners.

ADVANCED MATERIALS

Da/Pro Rubber is a custom manufacturer of precision rubber, TPE, and plastic molding products. The proprietary Da/Pro process adjusts for rubber compound and rubber part configuration variables so that it can produce high tolerance parts of consistent quality. The company offers complete in-house capabilities from design for moldability, rubber compound development, lab testing, mold construction, subassembly, and quality assurance.

Digital Manufacturing

Proto Labs’ quick-turn Protomold® injection molding and First Cut® CNC machining services are the fastest in the world at providing design engineers with real parts based on their 3D CAD models. We achieved this unique ability by applying proprietary software and parallel processing technologies to the automation of standard manufacturing processes, so engineers can finally have it all : real parts in as little as one day.

Electrical & Electronic

Since 1976, Glenn Taylor’s vision of an enterprising engineer has been our guiding force. Our goal is to design and manufacture standard industrial control products that meet or exceed customer and industry specifications for quality and operation. We engineer more features, more functions and more flexibility into our products, and we are able to offer a lifetime warranty for them.

Fastening & Joining

Bal Seal Engineering, Inc.’s original product was a plastic ring with a groove to house a coiled spring. Today, the company’s patented canted coil spring energized PTFE is at the core of its product offerings. Bal Seal offers custom-engineered sealing, connecting, conducting, and shielding products for medical electronics, medical device aerospace/defense, energy management, automotive, and industrial applications.

Fluid Power

Norgren’s vision is to create competitive advantage for its customers. By exploiting the potential of motion and fluid control technologies. For Norgren customers this means better results, faster/more efficient machines, improved machine performance, increased reliability/uptime and lower cost of ownership. Application specific solutions frequently involve integrated or modular combinations of actuator, control valve and air preparation technologies. Within the field of motion control Norgren develops solutions for automation applications and within the field of fluid control Norgren combines proven brands to offer solutions for handling air, water, oil and other fluids.

Mechanical

Arrow Gear Company is among the most technologically advanced gear manufacturers in the world. With a facility of over 145,000 square feet, Arrow is equipped for a full range of precision gear machining, heat treating and inspection capabilities for spiral bevel gears, spur and helical gears, curvic couplings – as well as complete gearboxes.

Arrow has earned a reputation for providing high precision gears to the global market for a wide variety of aerospace and commercial applications.

Arrow’s advanced technologies reach beyond machine tools alone. Arrow is equipped with design and development capabilities that are on the leading edge of the industry. Utilizing Gleason CAGE, GAGE, MINIGAGE, Finite Element and Fully Loaded TCA software, Arrow engineers can create computer models which accurately predict gear design performance. This process for contact pattern development is dramatically more efficient than conventional methods.

Motion Control

PBC Linear is a leader in providing linear and rotary solutions, specializing in everything from out-of-the-box components, to mechanical sub-assemblies, to complete linear systems. PBC Linear’s team of expert engineers draws experience from years of mechanical and design engineering both in the classroom and in the field. Their skilled staff, sophisticated tools, and innovative products create long lasting solutions for the toughest motion control problems.

Software

COMSOL Group provides software solutions for multiphysics modeling. A fast growing engineering software company with a proven track recor, Comsol was founded in July 1986 in Stockholm, Sweden, and has offices in Denmark, Finland, France, Germany, The Netherlands, Norway, India, Italy, Switzerland, United Kingdom, and U.S.A.

Switches & Sensors

MTS Sensors, a division of MTS Systems Corp., is the global leader in the development and production of magnetostrictive, linear-position and liquid-level sensors. Using MTS’s patented Temposonics® technology, the Sensors Division is continually developing new ways to apply magnetostrictive sensing technology to solve critical applications in a variety of markets worldwide, including steel, wood, plastics, metalworking, automotive, and off-highway. It also applies megnetostrictive technology to the packaging, oil, gas, food and beverage, and medical industries. MTS Sensors Division has facilities in the U.S., Germany, and Japan, and is an ISO 9001 certified supplier committed to providing innovative sensing solutions that deliver customers with reliable, cost-effective position-feedback devices.

Test & Measurement

Omega is a major US company that manufacturers more than 80% of its product offerings in house ─ and this percentage is continuously increasing. At a time when “outsourcing” seems to be the foundation of many US manufacturers, Omega Engineering, headquartered in Stamford, Connecticut, remains a notable exception. Omega enjoys this leadership position because it strongly advocates process automation to achieve high productivity and create quality products. When commercial equipment is used, in-house automation handles the input and output processes. Omega’s automation engineers are among the most talented, and it has invested substantially in the model shops and labs needed to support them. Working with an equally talented staff of software engineers, they produce a wide range of custom automation equipment.