IṢẸ́ ỌNÀ
ẸWÀ ÀTI ÌLERA
IṢẸ́ ỌWỌ́
ÀṢÀ ÀTI ÌTÀN
ÌṢERÉ
ÀYÍKÁ
OÚNJẸ ÀTI OHUN MÍMU
REVERSE ENGINEERING
SÁYẸ́ǸSÌ
ERÉ ÌDÁRAYÁ
ÌMỌ̀-Ẹ̀RỌ
ÀWỌN OHUN WÍWỌ̀
The Piston Ring: Sealed by the Gas It Holds Back
Early steam pistons were sealed with packing — hemp or leather pressed against the cylinder by adjustable rings. In the 1850s John Ramsbottom, locomotive superintendent of the London and North Western Railway, replaced it with a thin split ring of iron sprung into a groove round the piston. It is still how every piston in every engine is sealed.
The ring's own spring presses it lightly against the wall. The gas it is holding back gets into the groove behind it and presses it far harder — so the higher the pressure, the tighter the seal. Its one enemy is heat: the ring must have a gap so it does not jam when it grows.
This rung works out both effects and makes a split ring from a pipe to feel its spring.
Olùbẹ̀rẹ̀
About 2 hours
Ìlànà
1
1
Gas loading and the end gap
Gas loading and the end gap
Ń ṣí ìwé Jupyter…
2
2
Make a split ring and feel its spring
Make a split ring and feel its spring
Cut a 5 mm slice from a copper pipe slightly larger than a second, rigid tube that will be your 'bore'. Saw a 3 mm gap through the slice: that is the ring. It now springs open wider than the bore.
Squeeze it closed with your fingers and push it into the bore: it grips the wall all round. Hook the spring scale to it and pull it along the bore: the reading is the friction its spring alone produces.
Measure the gap with the feeler gauges when the ring is in the bore — that is how an engine builder checks a real ring: square in the bore, gap measured, compared with the specification.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Ọ̀pá bàbà0.1 mítàÀwọn irinṣẹ́ tí a nílò:
Ohun èlò ìgé òpó
Ìdìpọ̀ òǹwọ̀n àyè
Ẹ̀rọ Ìwọ̀n Agbára (Òṣùwọ̀n Ìsúnkì)
Òṣùwọ̀n Kálípà Díjítà Ìnṣì 63
3
History and context
History and context
**John Ramsbottom**, of the London and North Western Railway, introduced the narrow split cast-iron piston ring for locomotive pistons in the 1850s; 'Ramsbottom rings' replaced adjustable packing. No patent number is asserted here.
Modern pistons carry a stack: a top compression ring, a second ring that scrapes and seals, and an oil-control ring that wipes oil back down.
**Honest limits.** A ring seals least well at low pressure and at the moment the piston reverses; it wears, and the cylinder wears with it; and a stuck or broken ring lets gas past into the crankcase ('blow-by') and oil up into the combustion chamber.
Àwọn irinṣẹ́ tó nílò
4Blueprint tó jọra
Àwọn blueprint wọ̀nyí pín ìmọ̀ — ọ̀nà, ohun-èlò tàbí ìlànà
Packing Gland
láti ọwọ́ Forge
IṢẸ́ ỌWỌ́
42
0
0
0
0
0
O-Ring Seal
láti ọwọ́ Mary
Iṣẹ́ Irin
49
0
0
0
0
0
Drilling, Boring and Reaming: Three Tools, Three Different Jobs
láti ọwọ́ Emma
Iṣẹ́ Irin
28
0
0
0
0
0
Lubrication: The Film Does the Work, and More Grease Is Not More Lubrication
láti ọwọ́ Martin
Ìmọ̀-ẹ̀rọ
17
0
0
0
0
0
Rotative Beam Engine
láti ọwọ́ Martin
ÌMỌ̀-Ẹ̀RỌ
40
0
0
0
1
0
CC0 Àgbègbè Gbogbogbò
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