  : The concept is as old as forced lubrication systems, maybe even older. For as long as oil has been flowing down narrow pipes, they've had some sort of strainer. : The first are probably the capillary 'trimmings' (wicks) made of twisted wool, used on steam engines. These allow a slow flow of oil from an oil reservoir to flow into a bearing. They're small enough that they can be mounted individually on each joint of coupling rods. These locations are also likely to collect some dirt, so the filtering aspect is useful too. : The next development was the use of brass wire mesh strainers, again at first in total loss systems for steam engines. As it's a total loss system this isn't about straining collected bearing detritus from the oil, it's about removing dirt that gets in during filling. As it's total loss though, refilling is needed before each shift, so dirt ingress is a problem. : Some high-speed steam engines see the introduction of the sump or oil pan, thus permitting both splash lubrication or the first continuously pumped oil systems. These sumps collected as much condensed water as oil, so as well as the brass wire mesh there are also oil-water separators. : The first petrol engines are contemporaneous and have similar lubrication systems, largely by splash and only sometimes or partially by pump, for high stress areas. : Aircraft engines develop in WWI. These have a vast budget for materials, provided that performance and reliability are increased. We see much improved bearing materials, even silver alloys. Dry sump systems are used for in-line engines, as these are lighter than wet sumps as they need less oil to operate. There are also oil coolers. These high performance bearings rely on a reliable supply of clean oil through a hydrostatic bearing with very close tolerances. This is really the point when fine particle filtration becomes important and we see real filters, rather than just debris strainers. : Between the wars the Auto-Klean type of filter is important. This is a stack of fine steel disks and stars, with oil passing the gaps between them. They have a distinctive top handle which is turned a quarter turn every so often in use, scraping any debris into the centre. There are also centrifugal oil filtration systems built into crankshaft pulleys etc. (These lasted into the 1960s on at least one car, the Fiat 124 1438cc A series) : Around 1930 the high-speed diesel engine appears and starts to be used for trucks. This needs a fuel filter, as the injection system can't function without. It is this, not lubricating oil, that prompts the development of paper element filters with good flow rates. At first these are in steel bowls (glass for fuel), with a bare element. The element gains glued end discs, then an open-ended enclosing canister, then finally the familiar spin-on close-ended canister.   