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
Youblob (generated from this blueprint's notebook) · CC0
The Spool Valve: Steering Oil With a Sliding Rod
A pump makes flow and a cylinder makes force. Between them sits the valve that decides where the oil goes: to one end of the cylinder, to the other, or back to the tank. In almost every hydraulic machine that valve is a **spool**: a ground steel rod with raised lands, sliding in a bore with five ports — pressure, tank, two work ports, and a second tank.
Slide the spool one way and pressure goes to port A while B drains; slide it the other way and the roles swap; centre it and the ports are blocked or joined, depending on the spool's centre. The edges of the lands are orifices, so the spool also meters how fast.
This rung works out the metering, the choice between open and closed centre, and builds a transparent spool valve that shows the oil paths in coloured water.
Àárín
About 4 hours
Ìlànà
1
1
Metering edges and the centre condition
Metering edges and the centre condition
Ń ṣí ìwé Jupyter…
2
2
Each land edge is a throttle
Each land edge is a throttle
The spool meters flow the way any restriction does. The embedded blueprint shows how flow through a restriction depends on its area and the pressure across it.
3
3
Build a clear spool valve
Build a clear spool valve
Take 150 mm of clear acrylic tube with a smooth 20 mm bore. Drill five 6 mm holes in a line along one side, 20 mm apart, and glue a hose barb over each: from one end, **T**, **A**, **P**, **B**, **T**.
3D-print a spool: a 10 mm shaft carrying three lands, each 12 mm long with an O-ring groove, spaced so that when the spool is centred the middle land exactly covers **P** and the outer lands cover **A** and **B**. Fit O-rings sized to seal lightly in the bore. A handle on one end, a stop on the other.
Connect **P** to a garden hose through a ball valve, the two **T** ports to a bucket, and **A** and **B** to the two ports of the double-acting cylinder, or to two clear tubes standing up so you can see which one fills.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Ọ̀pá akiriliki (aláìdàrú)1 ẹyọ
Àkójọpọ̀ Ìsopọ̀ Páìpù PVC1 ẹyọ
Àkójọpọ̀ Òrùka O1 ẹyọ
Ọ̀pọ̀n Sílíkọ́nì2 mítà
Fáàlù ìdarí ọ̀nà1 ẹyọÀwọn irinṣẹ́ tí a nílò:
Ẹ̀rọ ìtẹ̀ 3D oníwàyà (FDM)
Okùn PETG
Ẹ̀rọ Ìlùkòkò Aláìlókùn
Àkójọ Orí Ìlùkòkò
Òṣùwọ̀n Kálípà Díjítà Ìnṣì 6
Ìbọn ìlẹ̀mọ́ gbígbóná
Bàkẹ́ẹ̀tì4
4
The three positions
The three positions
Ààyè Iṣẹ́ Blockly
Loading Blockly workspace...
5
5
Run it with coloured water
Run it with coloured water
Add food colouring to a bucket feeding a small submersible pump, or tint the hose supply with a dye injector, so the flow shows in the clear bore.
Centre the spool and open the supply: nothing moves, and the supply hose stiffens — that is a closed centre. Slide the spool slowly one way: first a thread of colour as the edge just cracks open, then a full stream into **A** while **B** drains to **T**. Slide it the other way and watch the paths swap.
Then turn the middle land down on a second printed spool so that, centred, it leaves a gap round **P**: now the supply runs straight through to **T** at the centre. That is an open centre.
Àwọn ohun èlò fún ìgbésẹ̀ yìí:
Àwọ̀ oúnjẹ (aró fún ríri ìṣàn omi)1 ẹyọ
Omi20 lítàÀwọn irinṣẹ́ tí a nílò:
Ẹ̀rọ ìfàmi tí a ń rì sínú omi
Aago Ìdúró6
6
A valve that will not control the load
A valve that will not control the load
Directional valve faults, in the order to check them.
Flow
Loading...
7
7
Context and honest limits
Context and honest limits
Spool valves go back to the steam age — slide valves on engines, piston valves on locomotives — and became the standard directional valve of oil hydraulics. Their symbols and port letters (P, T, A, B) are now standardised, so a circuit diagram from any maker reads the same way.
**Honest limits.** A spool always leaks a little through its clearance, so it cannot hold a load for long; a check valve does that. Flow through the edges also pushes on the spool (flow forces), which is why large valves are moved by pilot pressure rather than by hand. The printed model with O-rings shows the paths, not the metering: real spools seal by a micrometre clearance, not by rubber.
Àwọn ohun-èlò
7- Àyè
- Àyè
- 1 ẹyọÀyè
- 2 mítàÀyè
- 1 ẹyọÀyè
- 20 lítàÀyè
Àwọn irinṣẹ́ tó nílò
9- Àyè
- 1 vendor sell this, none ship to you yetÀyè
- Àyè
- Àyè
Blueprint tó jọra
Àwọn blueprint wọ̀nyí pín ìmọ̀ — ọ̀nà, ohun-èlò tàbí ìlànà
Throttling: Letting Some of It Past
láti ọwọ́ Emma
Ìmọ̀ Ẹ̀rọ
9
0
0
0
0
0
Orifice Plate Meter
láti ọwọ́ Emma
ÌMỌ̀-Ẹ̀RỌ
37
0
0
0
0
0
One Way Only: The Check Valve and the Bang It Makes
láti ọwọ́ Martin
Àwọn Irinṣẹ́
15
0
0
0
0
0
Safety Relief Valve
láti ọwọ́ Penny
ÌMỌ̀-Ẹ̀RỌ
41
0
0
0
0
0
O-Ring Seal
láti ọwọ́ Mary
Iṣẹ́ Irin
49
0
0
0
0
0
Hydraulic Accumulator
láti ọwọ́ Emma
Iṣẹ́ Irin
34
0
0
0
1
0
CC0 Àgbègbè Gbogbogbò
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