Mechanical & Fluid Systems

Multiturn Kit Encoders Without Batteries or Gears: A Cost-Efficient Approach for Rotary Position Measurement in Servomotors and Rotating Equipment

POSITAL is introducing a new set of component-level products that are designed to be built into servomotors or other types of equipment when real-time measurement of rotary position (angular displacement) or rotational speed is required. Based on POSITAL’s well-proven magnetic rotary encoder technology, these new products provide manufacturers with a flexible and cost-effective way of incorporating rugged and precise rotation measurement capabilities directly into their devices.

Posted in: White Papers, Mechanical Components, Mechanics, Motion Control

Magnetic Fields Enable New Soft Robots

Researchers from North Carolina State University have a found a new way to control robots. The team used magnetic fields to remotely manipulate microparticle chains embedded in soft robotic devices.

Posted in: News, Joining & Assembly, Drug Delivery, Automation, Robotics

Fundamentals of Wire, Cable, and Connectivity

Continuous supply of electric power or faultless data transfer, provided mostly through wiring, are primary requirements affecting virtually all systems. This results in stringent requirements for production, installation, and operation of cables.

Posted in: White Papers, Mechanical Components, Motion Control, Automation, Robotics

LAPP PLAYBOOK — Next Generation Cables For Factory Automation

Achieving maximum productivity and minimizing downtime are critical in production line equipment or any automation applications.

Posted in: White Papers, Aerospace, Defense, Mechanical Components, Mechanics, Motion Control

Development of the Orion Crew-Service Module Umbilical Retention and Release Mechanism

The design is highly modular, and can easily be adapted to other vehicles/modules and alternate commodity sets.

The Orion Crew-Service Module (CM/SM) umbilical retention and release mechanism supports, protects, and disconnects all of the cross-module commodities between the spacecraft's crew and service modules. These commodities include explosive transfer lines, wiring for power and data, and flexible hoses for ground purge and life support systems. Initial development testing of the mechanism's separation interface resulted in binding failures due to connector misalignments. Separation of the umbilical lines between the Crew Module (CM) and the Service Module (SM) happens as part of the vehicle separation activities prior to reentry. If the umbilical fails to separate successfully, the crew and spacecraft will likely be lost.

Posted in: Briefs, Mechanical Components, Mechanics, Architecture, Fasteners, Entry, descent, and landing, Spacecraft

Micro-Lid for Sealing a Sample Reservoir for Micro-Extraction Systems

Improved micro-extraction systems could be useful for military remote sensing using microfluidics.

Great strides are taken to miniaturize spaceflight instrumentation, particularly analytical systems such as liquid chromatographs, gas chromatographs, and mass spectrometers. With miniaturization of instruments, large amounts of samples are no longer required. Therefore, a lesser quantity of sample from the environment needs to be acquired and extracted. Current practices of sample extraction are large in volume and consume an enormous amount of power, which is inconsistent for microfluidic instruments in development. These consume minute amounts of power and are of low mass. There have been efforts to create micro-sample extraction systems; however, a downfall of those systems is the inability to automatically close sample reservoirs.

Posted in: Briefs, Mechanical Components, Mechanics, Containers, Seals and gaskets, Test equipment and instrumentation, Spacecraft

Single-Fluid-Pumped Radiators with Increased Turn-Down Ratio and Control in the Stagnation Regime

The system trades mass-optimized heat rejection for a human-rated, single-fluid pumped system of greater heat rejection range and passive control.

Fluid-pumped radiators are used to reject heat from structures to space. A fluid travels inside the structure to collect heat, and then travels external to the structure through radiators where the heat is rejected to space via radiation heat transfer. A radiator is essentially several tubes attached to a thermally conducting plate or face sheet. The fluid cools as it travels along the inside of the tubes, and then returns to the inside of the structure to repeat the heat rejection cycle. If the structure contains humans, the fluid in the structure must be nontoxic and nonflammable. Further, as space can be extremely cold (4 K), the fluid external to the structure may freeze, particularly during low-power operations where heat rejection needs are minimal. Freezing of the fluid renders the radiator inoperable, and unfreezing a radiator can be very difficult, power-intensive (i.e. heaters), and/or timely. For these reasons, two fluids may be used: one inside that is compatible with humans (e.g. water), and one outside that has a low freezing point (e.g. ammonia). The heat is then transferred from the inner loop to the external loop through a heat exchanger. This dual-loop system is more complex and heavier than a single-loop system. However, as the outer loop does not freeze as easily, the dual-loop radiator system can be operated at lower heat rejection loads, increasing its overall heat rejection range (or turn-down ratio) over that of the single-loop system.

Posted in: Briefs, Mechanical Components, Mechanics, Heat exchangers, Heat transfer, Radiators

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

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.