Metallic Glass Shatters Gear Limitations

Gears play an essential role in precision robotics, and they can become a limiting factor when the robots must perform in space missions. In particular, the extreme temperatures of deep space pose numerous problems for successful gear operation. At NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, CA, technologist Douglas Hofmann and his collaborators aim to bypass the limitations of existing steel gears by creating gears from bulk metallic glass (BMG).

Posted in: Articles, Aerospace, Manufacturing & Prototyping, Metals, Mechanical Components, Motion Control, Motors & Drives, Power Transmission, Robotics, Robotics, Alloys, Glass, Gears, Durability, Spacecraft

Servo Couplings for High-Tech Systems

Proper coupling ensures a design will meet performance requirements and have a long, trouble-free life.

Couplings are a critical part of system performance in high-tech applications, yet they are often one of the last components to be specified. Selecting the proper coupling ensures the equipment will meet performance requirements and have a long, trouble-free life. Poor coupling selection can lead to high maintenance costs, frequent downtime, and imprecise positioning.

Posted in: Articles, Joining & Assembly, Motion Control, Power Transmission, Sensors and actuators, Materials properties, Fittings, Parts

Adding SCADA to a Hydraulic Power Unit

With an increased focus on plant productivity and equipment reliability, Supervisory Control and Data Acquisition (SCADA) systems have become vital tools to reduce downtime while increasing asset reliability in hydraulic systems. A SCADA system is a computer system that essentially gathers and analyzes real-time data.

Posted in: Articles, Fluid Handling, Motion Control, Computer software and hardware, Hydraulic and pneumatic hybrid power, Productivity, Hydraulic control

Designing for Mechanical and Signal Integrity in Handheld Medical Treatment Applications

Handheld medical devices must perform across a wide range of device specifications and end-user environmental conditions. Mechanical and signal integrity of cable components is especially important for high-level performance, accuracy, durability, longevity, and user satisfaction. A great variety of insulating and jacketing material options exist for wire and cable in medical electronics. Performance factors that affect material selection decisions include biocompatibility, disinfection and sterilization compatibility, revision control assurance, environmental regulatory compliance, aesthetics, flexibility, durability, and cost. Subtle differences in priority may result in significant differences in product design, as well as overall cost.

Posted in: White Papers, White Papers, Manufacturing & Prototyping, Mechanical Components, Bio-Medical, Medical

Metal Stamping Design Guidelines

Metal Stamping provides an economical way to produce quantities of parts that can possess many qualities, including strength, durability, wear resistance, good conductive properties, and stability. In this paper, we are sharing some ideas that can help you design a part that optimizes all the features that the metal stamping process offers.

Posted in: Briefs, TSP, Aeronautics, Manufacturing & Prototyping, Materials, Mechanical Components, Design processes, Stamping, Metals, Parts

Airfoil-Shaped Fluid Flow Tool for Use in Making Differential Measurements

Researchers at NASA’s Marshall Space Flight Center have developed a suite of adaptable flow measurement devices that can be easily installed without compromising the structural integrity of existing conduits. With their simple installation procedures, the devices can be removed or exchanged without difficulty, allowing for temporary or extended use. The design is in-situ and self-contained, taking measurements from within the conduit, thereby offering more accuracy and allowing for opportunities to modify system operating parameters. Some of the designs can be used to mix the flow or inject a second fluid into the stream.

Posted in: Briefs, Fluid Handling, Mechanical Components, Mechanics, Measurements, On-board diagnostics, On-board diagnostics (OBD), Hoses

Piezo-Actuated, Fast-Acting Control Valve

The ability of this valve to throttle makes it suitable for regulators and cold gas thrusters.

High-power electric propulsion systems have the potential to revolutionize space propulsion due to their extremely high performance. This can result in significant propellant savings on space vehicles, allowing the overall mass to shrink for launch on a less expensive vehicle, or to allow the space vehicle to carry more payload at the same weight. Many electrical propulsion systems operate in pulse mode, pulsing hundreds or thousands of times per second. Creating reliable valves that can operate in pulse mode for extremely long periods and at low power is critical in these applications. Current solenoid valves have difficulty achieving the life requirements. In addition, a valve with the ability to throttle has the potential to simplify the entire propulsion system by eliminating the need for pressure regulators or latching valves.

Posted in: Briefs, Fluid Handling, Mechanical Components, Mechanics, Valves, Throttles, Reliability, Electric vehicles, Spacecraft

Interface Between STAR-CCM+ and 42 for Enhanced Fuel Slosh Analysis

Fuel slosh is excited during spacecraft maneuvers. The forces and torques exerted on the spacecraft by the slosh must be controlled by the attitude control system to maintain correct pointing and spacecraft orbit. In some rare cases, the attitude control system may excite the slosh and cause a loss of control of the spacecraft, or the expected spacecraft motion from a certain control command will be different enough from the control command to adversely affect the mission. By linking the computational fluid dynamics (CFD) and the flight simulation software, the fuel slosh can be modeled at high fidelity by the CFD software, while receiving and passing information to and from the flight simulation software, thus increasing the fidelity of both models. In the past, fuel slosh has either been modeled with an equivalent mechanical model, such as a pendulum, or with a standalone CFD simulation.

Posted in: Briefs, Fluid Handling, Mechanical Components, Mechanics, Computational fluid dynamics, Computer simulation, Attitude control, Data exchange, Fuel tanks, Spacecraft

Mechanisms for Achieving Non-Sinusoidal Waveforms on Stirling Engines

The current state-of-the-art Stirling engines use sinusoidal piston and displacer motion to drive the thermodynamic cycle and produce power. Research performed at NASA Glenn has shown that non-sinusoidal waveforms have the potential to increase Stirling engine power density, and could possibly be used to tailor engine performance to the needs of a specific application. However, the state-of-the-art Stirling engine design uses gas springs or planar springs that are very nearly linear, resulting in a system that resonates at a single frequency. This means that imposing non-sinusoidal waveforms, consisting of multiple frequencies, requires large forces from the drive mechanism (either the alternator or the crank shaft). These large forces increase losses, and increase the size and requirements of the control system. This innovation aims to reduce the external forcing requirements by introducing internal mechanical components that provide the forces necessary to achieve the desired waveforms.

Posted in: Briefs, Mechanical Components, Mechanics, Motion Control, Alternators, Crankshafts, Engine efficiency, Stirling engines

RFID Cavity

Potential applications include inventory tracking for containers such as waste receptacles or storage containers.

This technology provides a method for interrogating collections of items with radio-frequency identification (RFID) tags. It increases the read accuracy, meaning that more of the item tags will be successfully read. It also permits smaller tag antennas than would otherwise be necessary.

Posted in: Briefs, Fluid Handling, Mechanical Components, Mechanics, Downsizing, Antennas, Product development, Radio-frequency identification, Reliability

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