Flexure Design and Testing for STC Stirling Convertors

Qiu, Songgang; Peterson, Allen A.; Augenblick, Jack E.

doi:10.2514/6.2003-6040

Cited by 15 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rawling et al have designed the smallest spiral arm disc having four arms, which is equal to the size of a coin around 1.5 inches. The disc is made from tempered steel and photochemically itched 18 . Meijers et al have described the concept of flexural pack.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of difference in diameter enlargement and circularity of micro-holes drilled by flexural spindle head

Shinde

Lekurwale

2020

Journal of Micromanufacturing

View full text Add to dashboard Cite

The flexural bearing or the flexural cartridge allows very nano-meter axial displacement movement, which is frictionless and noiseless. The repeatability of the mechanism obtained is achieved by bending of the load element. The bearing can operate under stringent conditions such as vacuum, elevated temperatures (0–40 °C), and moist conditions. Hence, due to these indigenous properties, these bearings are observed in applications such as linear bearing of linear compressor, flexural bearing electromagnetic linear actuator, and parasitic error-free mechanism. The endorsed capability of obtaining high-level positional accuracy along with repeatability leads to design and development of low-cost flexural cartridge for micro-drilling spindle head. This flexural cartridge provides a linear guideway while feeding inside the test specimen (in micro-drilling operation). The designed head dampens and nullifies the force, acting on the shaft carrying the micro-tool. The designed spindle head carrying the three-leg spiral flexural stack is assembled on the designed machine tool. The run out measured on the spindle shaft is 50 µm. Four test specimens, namely aluminum, brass, acrylic and mild steel, are drilled by three drills of diameter 1 mm, 0.8 mm, and 0.5 mm each. The main objective of the article is to understand the differential analysis of diameter enlargement and circularity between the experimental method and the numerical method. The answers predicted by the experimental method may have second possible value as it depends upon judgment of inscribing the circle/points in the computer-aided design (CAD) environment. This ambiguity is excluded by the MATLAB code, which gives one specific answer. The maximum difference in diameter enlargement for aluminum, brass, acrylic, and mild steel specimens are 3.8 µm, 11 µm, 24.6 µm, and 16.1 µm, respectively, whereas the maximum difference in circularity for the same specimens is 11.8 µm, 1.3 µm, 8.2 µm, and 16.8 µm, respectively. This difference is termed as the |error|.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of difference in diameter enlargement and circularity of micro-holes drilled by flexural spindle head

Shinde

Lekurwale

2020

Journal of Micromanufacturing

View full text Add to dashboard Cite

show abstract

“…Flexures are another form of bearing system used in free-piston Stirling convertors (Qiu, Peterson and Augenblick, 2003) and their design is optimized over many parameters and iterated with linear alternator and Stirling modeling. Since they are bending during the cycle, they interact with the fluid.…”

Section: Flexuresmentioning

confidence: 99%

Towards Fully Three-Dimensional Virtual Stirling Convertors For Multi-Physics Analysis and Optimization

Dyson¹,

Geng²,

Tew³

et al. 2008

Engineering Applications of Computational Fluid Mechanics

View full text Add to dashboard Cite

ABSTRACT:The desire for fast, low-cost, and reliable Stirling convertor design decisions has motivated the development of a comprehensive in-house Stirling analysis capability. One of the predominant goals of this project is to enhance the Stirling industry's suite of design tools beyond the currently employed one-dimensional analysis to the level of a virtual three-dimensional full fidelity convertor including structural, mechanical, electromagnetic, and thermal dynamics. This virtual Stirling engine/linear alternator coupling can be used to pre-test prototype hardware, examine internal part performance, and investigate design modifications before expensive convertors are fabricated. An approach is presented for incorporating the complete three-dimensional geometry of modern Stirling convertors and coupling this with multi-physics capability to examine the effects of magnetic, pressure, gravity, spring, and inertial forces on startup behavior, material creep, and overall system performance/efficiency/reliability.

show abstract

“…Flexure springs are known for their long service life and maintenance-free operation, which are mainly due to the elimination of contacting parts [131]. There are several papers on flexure design and optimization, using FEA and experimental tests, and sensitivity analyses in order to identify an optimized design.…”

Section: Flexure Springs (Bearings)mentioning

confidence: 99%

“…They demonstrated the reliability of over 99% confidence level in their spring design. The models considered both the surge and rocking modes of the spring arms [131]. Chen springs for linear compressor purposes using FEA.…”

Section: Flexure Springs (Bearings)mentioning

confidence: 99%

See 1 more Smart Citation

Design and Optimization of Dynamic System for a One-kW Free Piston Linear Engine Alternator-GENSETS Program

Meymian¹

View full text Add to dashboard Cite

In power/energy systems, free-piston linear machines are referred to as a mechanism where the constrained crank motion is eliminated and replaced with free reciprocating piston motion.Depending on the application, the piston motion can be converted into other types of energy and includes compressed air/fluid, electricity, and high temperature/pressure gas. A research group at West Virginia University developed a free-piston linear engine alternator (LEA) in 1998 and have achieved significant accomplishment in the performance enhancement of the LEAs to date. The present LEA design incorporates flexure springs as energy restoration components and as bearing supports. The advantages of using flexure springs are threefold and include: (1) it increases the LEA's stiffness and resonant frequency, and hence the power density; (2) it eliminates the need for rotary or linear bearings and lubrication system; and (3) it reduces the overall frictional contact area in the translator assembly which improves the durability.The current research focuses on the design and optimization of the flexure springs as the system's resonant dominating component for a 1 kW free-piston LEA. First, the flexure springs were characterized according to the LEA's target outputs and dimensional limitations. The finite element method (FEM) was used to analyze the stress/strain, different modes of deformation, and fatigue life of a range of flexure spring designs under dynamic loadings. Primary geometric design variables included the number of arms, inside and outside diameter, thickness, and arm's length.To find the near-optimum designs, a machine learning algorithm incorporating the FEM results was used in order to find the sensitivity of the target outputs to the geometrical parameters. From the results, design charts were extracted as a guideline to flexure spring selection for a range of operations. Then, methods were introduced, investigated, and analyzed to improve the overall energy conversion performance and service life of the flexure springs and the overall LEA system.

show abstract

Flexure Design and Testing for STC Stirling Convertors

Cited by 15 publications

References 5 publications

Experimental and numerical investigation of difference in diameter enlargement and circularity of micro-holes drilled by flexural spindle head

Experimental and numerical investigation of difference in diameter enlargement and circularity of micro-holes drilled by flexural spindle head

Towards Fully Three-Dimensional Virtual Stirling Convertors For Multi-Physics Analysis and Optimization

Design and Optimization of Dynamic System for a One-kW Free Piston Linear Engine Alternator-GENSETS Program

Contact Info

Product

Resources

About