Mechanical & Fluid Systems

Rugged Iris Mechanism

Advantages include capability for full obscuration, low friction, and general adaptability of design.

A rugged iris mechanism has been designed to satisfy several special requirements, including a wide aperture in the “open” position, full obscuration in the “closed” position, ability to function in a cryogenic or other harsh environment, and minimization of friction through minimization of the number of components. An important element of the lowfriction aspect of the design is maximization of the flatness of, and provision of small gaps between, adjacent iris blades. The tolerances of the design can be very loose, accommodating thermal expansions and contractions associated with large temperature excursions. The design is generic in that it is adaptable to a wide range of aperture sizes and can be implemented in a variety of materials to suit the thermal, optical, and mechanical requirements of various applications.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Design processes, Optics, Optics, Thermodynamics, Thermodynamics, Parts

Alignment Stage for a Cryogenic Dilatometer

A low-friction, low-thermal-expansion kinematic design affords stability and precise adjustability.

A three degree of freedom alignment stage has been designed and built for use in a cryogenic dilatometer that is used to measure thermal strains. The alignment stage enables precise adjustments of the positions and orientations of optical components to be used in the measurements and, once adjustments have been completed, keeps the components precisely aligned during cryogenic dilatometer operations that can last as long as several days.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Calibration, Heat resistant alloys, Test equipment and instrumentation, Thermal testing

Variable-Pressure Washer

Clamping force would be applied in a specified nonuniform pattern.

The variable-pressure washer (VPW) is a proposed device that is so named because (1) it would play the role similar to that played by an ordinary washer, except that (2) the clamping pressure applied by it would vary with either circumferential or radial position. In a typical contemplated application, the radially varying clamping pressure would be used to obtain more nearly uniform compression on a pair of concentric seals (e.g., an O-ring or a gasket) in an assembly that experiences larger deformations normal to the sealing surface for locations around the outer diameter of the attachment flange when compared to locations around the inner diameter.

Posted in: Briefs, Mechanical Components, Mechanics, Tools and equipment, Fittings, Seals and gaskets

Rotating Desk for Collaboration by Two Computer Programmers

Two programmers can work together or alternately with minimal stress.

A special-purpose desk has been designed to facilitate collaboration by two computer programmers sharing one desktop computer or computer terminal. The impetus for the design is a trend toward what is known in the software industry as extreme programming — an approach intended to ensure high quality without sacrificing the quantity of computer code produced. Programmers working in pairs is a major feature of extreme programming.

Posted in: Briefs, Mechanical Components, Mechanics, Design processes, Collaboration and partnering, Product development

Magnetically Attached Multifunction Maintenance Rover

This robot could move along a ferromagnetic structure in any orientation.

A versatile mobile telerobot, denoted the magnetically attached multifunction maintenance rover (MAGMER), has been proposed for use in the inspection and maintenance of the surfaces of ships, tanks containing petrochemicals, and other large ferromagnetic structures. As its name suggests, this robot would utilize magnetic attraction to adhere to a structure. As it moved along the surface of the structure, the MAGMER would perform tasks that could include close-up visual inspection by use of video cameras, various sensors, and/or removal of paint by water-jet blasting, laser heating, or induction heating.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Imaging, Imaging and visualization, Sensors and actuators, Imaging, Imaging and visualization, Sensors and actuators, Maintenance, Repair and Service Operations, Maintenance, repair, and service operations, Robotics, Magnetic materials, Marine vehicles and equipment

Alternative Way of Shifting Mass To Move a Spherical Robot

A payload would change its position by lengthening and shortening suspension cables.

An alternative method of controlled shifting of the center of mass has been proposed as a means of locomotion of a robot that comprises mostly a payload inside a hollow, approximately spherical shell. The method would be applicable to robots that include rigid, semirigid, or flexible inflated shells, including those of the “beach-ball rover” type, variants of which have been described in several previous NASA Tech Briefs articles.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Sensors and actuators, Sensors and actuators, Kinematics, Robotics

Ultrasonic/Sonic Jackhammer

Advantages include low noise, low vibration, and low average power demand.

An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices, the first of which were reported in “Ultrasonic/Sonic Drill/Corers With Integrated Sensors” (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2003), page 38. Each of these devices cuts into a brittle material by means of hammering and chiseling actions of a tool bit excited with a combination of ultrasonic and sonic vibrations. A small-scale prototype of the USJ has been demonstrated. A fully developed, full-scale version of the USJ would be used for cutting through concrete, rocks, hard asphalt, and other materials to which conventional pneumatic jackhammers are applied, but the USJ would offer several advantages over conventional pneumatic jackhammers, as discussed below.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Tools and equipment, Drilling, Acoustics, Vibration, Acoustics, Vibration


Vortex-generating microscopic robots would move in swarms.

The term “vortobots” denotes proposed swimming robots that would have dimensions as small as micrometers or even nanometers and that would move in swarms through fluids by generating and exploiting vortices in a cooperative manner. Vortobots were conceived as means of exploring confined or otherwise inaccessible fluid environments: they are expected to be especially attractive for biomedical uses like examining the interiors of blood vessels.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Cardiovascular system, Fluids and secretions, Medical equipment and supplies, Robotics

Two SMA-Actuated Miniature Mechanisms

These mechanisms represent two different approaches to latch/release operation.

The figures depict two miniature mechanisms actuated by strips made of shape-memory alloy (SMA). A typical SMA is a nickel-titanium alloy known by the trade name “Flexinol” or “Nitinol.” In preparation for a typical application, a suitably sized and shaped piece of an SMA is deformed by a predetermined amount at the lower of two operating temperatures, then mounted in a mechanism. When stroking of the mechanism in one direction is desired, the piece of SMA is heated above a transition temperature to make it return to the “remembered” undeformed state. When stroking of the mechanism in the opposite direction is desired, the SMA is cooled below the transition temperature to make it return to the deformed state.

Posted in: Briefs, Mechanical Components, Mechanics, Downsizing, Sensors and actuators, Sensors and actuators, Product development, Nickel alloys, Smart materials, Titanium alloys

Piezo-Operated Shutter Mechanism Moves 1.5 cm

This shutter is designed for use as part of an atomic clock.

The figure shows parts of a shutter mechanism designed to satisfy a number of requirements specific to its original intended application as a component of an atomic clock to be flown in outer space. The mechanism may also be suitable for use in laboratory and industrial vacuum systems on Earth for which there are similar requirements. The requirements include the following:

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Mountings, Parts, Test equipment and instrumentation, Industrial vehicles and equipment, Spacecraft

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