Mechanical Components

Unique Method for Orifice Production

To produce accurate, repeatable orifices, all the variables that might influence the Cd Value (Coefficient of Discharge) must be controlled during production. This includes the orifice hole length, edges, surface finishes, roundness and the elimination of all tool marks, burrs, ragged edges and irregularities. If any one of these areas is not perfectly managed, the orifice flow rates will vary from piece to piece thereby making it impossible to predict flow with any accuracy.

Posted in: White Papers, White Papers, Mechanical Components, Mechanics
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The Ultimate Shaft-To-Hub Connection

Polygon Shapes - Multi-Faceted Problem Solvers

Kinematically ground polygonal shapes have been used as drive connections for more than 45 years. What is now referred to as Polygon Systems was developed by Fortunawerke, Stuttgart, West Germany, who patented a grinding machine capable of producing matched polygonal shaft and bore diameters.

Posted in: White Papers, White Papers, Mechanical Components, Mechanics
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Non-Destructive Damping Measurement for MEMS Acceleration Switches

Determining damping coefficients is important for categorizing how each sensor or switch operates.

Microelectromechanical systems (MEMS) three-axis acceleration threshold sensors have been developed to measure acceleration threshold levels using voltage switching when the threshold is reached. Switches with different damping coefficients result in different mechanical impedances and response times. Analytical and numerical methods to model damping coefficient values based on empirical data are needed to characterize three-axis acceleration sensors; traditional methods use the displacement of an underdamped system to calculate the damping ratio.

Posted in: Briefs, Aerospace, Defense, Mechanical Components, Simulation and modeling, Sensors and actuators, Switches
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Flange Couplings

RINGFEDER POWER TRANSMISSION (Westwood, NJ) has announced the launch of its new RfN 5571 series flange coupling for heavy industry. RINGFEDER® flange couplings provide a superior solution to standard press fits. Equipped with the Ringfeder Shrink Disc this new series eliminates the needs for additional components such as keyways or shims. Eliminating the need for heating and cooling of the part reduces installation complexity. RINGFEDER® flange couplings are slip fit with frictional engagement achieved by torqueing the shrink disc screws. Available with hexagon head screws or hexagon socket head cap screws. Some of the advantages provided by this system are: a stronger connection than keyway systems, no wear parts, higher torque carrying capacity, backlash-free shaft hub connection, and a high level of true running accuracy.

For Free Info Visit http://info.hotims.com/55588-514

Posted in: Products, Defense, Consumer Product Manufacturing, Joining & Assembly
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Damping Measurement for Wafer-Level Packaged MEMS Acceleration Sensors

Two methods were developed for mechanical analysis of MEMS sensors.

Army Research Laboratory, Adelphi, Maryland

Microelectromechanical system (MEMS) three-axis acceleration threshold sensors have been developed to measure acceleration threshold levels using voltage switching when the threshold is reached. Determining damping coefficients is important for categorizing how each threshold sensor or switch operates. Switches with different damping coefficients result in different mechanical impedances and response times. Analytical and numerical methods to model damping coefficient values based on empirical data are needed to characterize three-axis acceleration sensors; traditional methods use the displacement of an underdamped system to calculate the damping ratio.

Posted in: Briefs, Defense, MEMs, Sensors, Measuring Instruments, Sensors and actuators, Switches
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3-D Manufacturing of Titanium Components Takes Off

MRO providers are discovering ways to innovate their procedures while remaining viable and profitable through the current downturn in government spending. Read more at http://articles.sae.org/13268.

Posted in: Articles, DTB, Aerospace, Defense, Mechanical Components
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Rotating Detonation-Wave Engines

Rotating detonation engines have the potential to increase the performance of airbreathing propulsion devices.

All Navy aircraft and missiles use gasturbine engines for propulsion. Many ships are also dependent on gasturbine engines to generate both propulsive power and electricity. These engines are fundamentally similar to engines used to power commercial airplanes. Future ships moving to an “all electric” paradigm for the propulsion system will still require these gas-turbine engines to generate electricity for the propulsion system and also for other critical onboard systems. Because of the amount of power required by modern warfighting ships, and the prospect that this power requirement will only increase, there is a strong interest in improving the specific fuel consumption of these engines.

Posted in: Briefs, TSP, Mechanical Components, Electric power, Fuel economy, Gas turbines, Marine vehicles and equipment, Military aircraft, Missiles
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Thermal Analysis and Microhardness Mapping in Hybrid Laser Welds in a Structural Steel

Hardness values of the weldment are used as an acceptance criteria for certain industrial applications involving structural steel.

The concept of combining a laser welding system with a conventional arc welding system (GTAW) was first proposed in order to improve the stability of the laser welding system and to allow greater flexibility in part fit-up. Prior research stated that using a YAG laser at a power of 3 kW, one was able to hybrid laser weld a 4-mm-thick aluminum alloy at a speed of 4 n/min. For a mild steel plate, butt welding at 1 m/min with 5 kW of 6-mm-thick plate was realized. Just as significantly as the weld speed was the ability to hybrid laser weld with gaps up to 1.5 mm in a plate 6 mm thick. The glass metal arc welding (GMAW) laser hybrid process can increase the gap bridging ability, i.e., it appreciably broadens the range of tolerances with regard to edge preparation quality. The arc’s energy input in the hybrid welding process also permits control of the cooling conditions. Via the keyhole, the laser beam brings about easier ignition of the arc, stabilization of the arc welding process, and penetration of the energy deep into the material. The improvement of the energy input leads to a greater welding depth and speed being achieved with the hybrid process compared with individual processes on their own.

Posted in: Briefs, TSP, Mechanical Components, Lasers, Welding, Steel, Thermal testing
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Encapsulated Ball Bearings for Rotary Micro Machines

This bearing design can be used in MEMS elements for micro-motors and micro-turbomachinery.

Microelectromechanical systems (MEMS)-fabricated silicon rotary elements for micro-motors, micro-generators, and micro-turbomachinery have received growing attention with applications in power conversion and actuation. Within these technologies, the bearing mechanism is the primary determinant of device performance and reliability. Active bearings, such as magnetic or electrostatic, have the advantage of being controlled during the operation, but at the cost of the accompanying circuitry. Passive bearings span a large range of velocities that include center-pin bushings with low revolution rates possible, and hydrostatic or hydrodynamic bearings with high revolution rates possible.

Posted in: Briefs, TSP, Mechanical Components, Microelectromechanical devices, Bearings
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Reverse Pressure Capable Finger Seal

Finger seals are a contacting air-to-air seal technology that allows for low leakage in high-speed and high-temperature operating conditions.

Each finger seal consists of a number of multiple thin metal laminates, each with a multitude of flexible projections that are referred to as “fingers.” To form a functional seal, multiple laminates are formed into a stack, with each laminate oriented so that the slots between its fingers cover the slots of the neighboring laminates. For protection and support of the laminates, forward and aft cover plates are placed on each side of the finger seal stack. A high pressure exists on one side of the seal, providing a driving force to push the air from one side of the seal to the other.

Posted in: Briefs, TSP, Mechanical Components, Coatings, colorants, and finishes, Seals and gaskets
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