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Flexure hub washer: Ø12 to Ø26.4 × 2 mm
What goes between the hubs in a flexure bearing stack? · Hardware · basis: Washer = the leaf hub: Ø hub × leaf bore, 2 mm thick, the same as the rim spacer
Long Earth Society build part. Flexure-suspended displacer on the LES free-piston test bed. The engines
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 5 in table
Notes
- A 2 mm washer the size of a leaf's hub, with the leaf's bore, that sits between the two leaf hubs of a stack: as thick as the 2 mm rim spacer between the leaf rims, so both leaves stay flat and parallel.
- Ø12 × Ø4, Ø13.2 × Ø5, Ø17.6 × Ø5, Ø22 × Ø8, Ø26.4 × Ø8 for the Ø40 to Ø120 leaves.
Sizes
| flexure_od_mm | od_mm | bore_mm | thickness_mm |
|---|---|---|---|
| 40 | 12 | 4 | 2 |
| 60 | 13.2 | 5 | 2 |
| 80 | 17.6 | 5 | 2 |
| 100 | 22 | 8 | 2 |
| 120 | 26.4 | 8 | 2 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| hub-clamp bore | Ø4 / Ø5 / Ø8 | rod, tube or centring bush | slide | hub-clamp-* |
| hub washer thickness | 2 (= rim spacer) | the two leaf hubs either side | designed | hub-clamp-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| NASA (NTRS, public domain) | Free-piston Stirling convertor flexure bearing development and life testing (2005) | US Government work, public domain | |
| NASA (NTRS, public domain) | Flexure bearing design for free-piston Stirling engines (1986) | US Government work, public domain | |
| NASA (NTRS, public domain) | Advanced Stirling Radioisotope Generator (ASRG) engineering unit (2011) | US Government work, public domain | |
| Wikipedia | Flexure bearing | web | CC BY-SA 4.0 (text) |
| Sunpower (AMETEK) | Free-piston Stirling technology overview | web | Sunpower site verify |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 5 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| hub-clamp-40-b4 | hub washer Ø12, Ø4 bore, 2 thick (= the rim spacer): between the two leaf hubs of a stack | STEP · STL |
| hub-clamp-60-b5 | hub washer Ø13.2, Ø5 bore, 2 thick (= the rim spacer): between the two leaf hubs of a stack | STEP · STL |
| hub-clamp-80-b5 | hub washer Ø17.6, Ø5 bore, 2 thick (= the rim spacer): between the two leaf hubs of a stack | STEP · STL |
| hub-clamp-100-b8 | hub washer Ø22, Ø8 bore, 2 thick (= the rim spacer): between the two leaf hubs of a stack | STEP · STL |
| hub-clamp-120-b8 | hub washer Ø26.4, Ø8 bore, 2 thick (= the rim spacer): between the two leaf hubs of a stack | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=flexure-hub-clamp-washer
How it fits
Goes in or on
Planar spiral flexure bearing leavesbetween leaf hubs, same boreConnects to
Flexure hub collarscollars clamp the hub stack
Flexure hub centring bushrides on the bush when the rod is smaller than the boreIn these build lists
Free-piston Stirling, 2 in tri-clampNo crank: piston and displacer each hang on a stack of spiral flexures, with a t…You might also need
Questions
What size is the hub washer for an Ø80 flexure?
Ø17.6 × Ø5 bore × 2 mm, the same thickness as the rim spacer.
Which hub washer goes with which leaf?
The one with the same OD: Ø12 for Ø40 leaves, Ø13.2 for Ø60, Ø17.6 for Ø80, Ø22 for Ø100, Ø26.4 for Ø120, each with that leaf's bore.