{{Short description|Mechanical device}}
A '''hydrospring''' or '''hydro-spring''' is a spring damped by hydraulic fluid (typically oil) being driven through holes in a piston, as the piston moves in response to a force.
The spring is often made of rubber. Inside a rubber hydrospring there are hydraulic viscous damping systems which damp movement in all three directions but require very few parts. Even the slack adjustment may be integrated into the element.<ref>{{Cite conference|url=http://railknowledgebank.com/Presto/content/GetDoc.axd?ctID=MTk4MTRjNDUtNWQ0My00OTBmLTllYWUtZWFjM2U2OTE0ZDY3&rID=NDI1NA==&pID=Nzkx&attchmnt=VHJ1ZQ==&uSesDM=False&rIdx=MzI0Ng==&rCFU=|format=pdf|title=Wear and Energy Saving Bogie Design with Rubber Primary Springs – Principles and Experiences|last=Hecht|first=Markus|conference=IHHA Specialist Technical Session (STS)|location=Kiruna, Sweden|year=2007}}</ref>
==Application== Hydrosprings are used mainly as shock absorbers in applications such as damped suspension in railway bogies, bulldozer blade shock absorbers and as recoil absorbers for artillery.{{cn|date=April 2026}}
==Gallery== <gallery> Rubber Hydrospring.png|A railway type rubber hydrospring<ref>{{cite patent |country=EP |number=1369616 |status=patent}}</ref> Rubber Hydrospring Cross Section Up.png|A railway type rubber hydrospring in relaxed state Rubber Hydrospring Cross Section Down.png|A railway type rubber hydrospring in compressed state 60PounderRecoilMechanismDiagram.jpg|Hydro-spring recoil system of British WWI 60 pounder gun, with working explained </gallery>
==See also== * Dashpot * Garter spring
==References== {{Reflist}} * [https://web.archive.org/web/20060811053146/http://www.afms1.belvoir.army.mil/dictionary/h_terms.htm Army Dictionary - see ''hydrospring''] * [https://web.archive.org/web/20060811052709/http://www.afms1.belvoir.army.mil/dictionary/r_terms.htm Army Dictionary - see ''recoil cylinder''] * [https://web.archive.org/web/20070311012655/http://resistoflexindia.com/railways_hydrospring.asp A railway hydrospring]
==External links== *[https://chinacustomspring.com/ Custom-Made Spring]
Category:Springs (mechanical)