Fluid system

1. An oil reservoir system comprising:

an oil container comprising an oil reservoir which is in fluidic communication with an oil circulation system of an engine, a vent port, a headspace which is in fluidic communication with the vent port, and an inlet and an outlet which each independently comprise a port comprising a self-sealing valve or a non-return valve; and

an oil filter located in an interior of the oil container and in fluidic communication with the oil reservoir,

wherein the oil filter is constrained such that when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the oil reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil.

2. An oil reservoir system according to claim 1 , wherein, when oil is circulated by the oil circulation system of the engine, the oil filter is at least partially, or fully, submerged in oil in the oil reservoir.

3. An oil reservoir system according to claim 1 , wherein the oil filter comprises a filter medium which has an inner surface defining an inner region of the filter medium and an outer surface, wherein the inner surface is of a smaller surface area than the outer surface, and, when oil is circulated by the oil circulation system of the engine, oil is directed to the inner region of the filter medium from where it is forced outward through, and out of, the filter medium.

4. An oil reservoir system according to claim 1 , wherein the oil filter comprises a filter medium which has an inner surface defining an inner region of the filter medium and an outer surface, wherein the inner surface is of a smaller surface area than the outer surface, and, when oil is circulated by the oil circulation system of the engine, oil is directed to the outer surface of the filter medium from where it is forced inward through, and out of, the filter medium into the inner region, before entering the body of oil of the oil reservoir.

5. An oil reservoir system according to claim 1 , wherein the oil filter comprises a tubular filter medium defining a central channel and, when oil is circulated by the oil circulation system of the engine, oil is forced radially through the filter medium.

6. An oil reservoir system according to claim 1 , wherein the oil filter comprises a filter housing comprising an inlet for oil and an outlet, and wherein the inlet and outlet of the filter housing each comprise a conduit which includes a non-return valve.

7. An oil reservoir system according to claim 1 , wherein the oil filter further comprises an overflow relief configured such that oil entering the oil filter is diverted so that it does not pass through the filter medium of the filter and does not entrain particulate material which is held by the filter medium when the filter medium is blocked or there is excessive back pressure.

8. An oil reservoir system according to claim 7 , wherein the overflow relief comprises a bypass valve.

9. An oil reservoir system according to claim 1 , wherein the inlet is in fluidic communication with the oil circulation system of the engine and the oil filter is arranged such that oil entering the inlet is conveyed directly to the oil filter.

10. An oil reservoir system comprising:

an oil pan located within a sump of an engine, wherein the oil pan comprises an oil reservoir which is in fluidic communication with an oil circulation system of the engine, wherein the oil circulation system comprises a pump in the oil reservoir, and wherein the pump is arranged to pump oil from the oil reservoir to the engine via a first outlet of the pump;

a headspace which is in fluidic communication with a ventilation system of the engine; and

an oil filter located in the oil pan and in fluidic communication with the oil reservoir, wherein the oil filter is in fluid communication with a second outlet of the pump which supplies oil which has been pressurized by the pump, and wherein the oil filter is constrained such that when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the oil reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil.

11. An oil reservoir system according to claim 1 , wherein, when oil is circulated by the oil circulation system of the engine, entrained gas is separated from suspension in the oil upon passage through the filter medium of the filter and gas exiting the oil filter passes through the body of oil in the oil reservoir to the ventilated headspace.

12. A method of reducing the amount of entrained gas in an oil of an oil reservoir system for an engine, which engine comprises an oil circulation system, said method comprising the steps of i) locating an oil filter in an oil reservoir within an oil container of the oil reservoir system, wherein the oil container comprises an inlet and an outlet which each independently comprise a port comprising a self-sealing valve or a non-return valve; and ii) constraining the oil filter such that, when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the oil reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil.

13. A method according to claim 12 , wherein the method comprises arranging the oil filter such that oil entering the inlet is conveyed directly to the oil filter.

14. An oil reservoir system according to claim 10 , wherein the ventilation system comprises either a closed crankcase ventilation system or a positive crankcase ventilation (PCV) system.

15. A method of reducing the amount of entrained gas in an oil of an oil reservoir system for an engine, which engine comprises an oil circulation system, said method comprising the steps of i) locating an oil filter in an oil reservoir within an oil pan located within a sump of the engine, wherein the oil circulation system comprises a pump in the oil reservoir, wherein the pump is arranged to pump oil from the oil reservoir to the engine via a first outlet of the pump, and wherein the oil filter is in fluid communication with a second outlet of the pump which supplies oil which has been pressurized by the pump; and ii) constraining the oil filter such that, when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil.

16. An oil reservoir system comprising:

an oil container comprising an oil reservoir which is in fluidic communication with an oil circulation system of an engine, a vent port, a headspace which is in fluidic communication with the vent port, and an inlet and an outlet which each independently comprise a port comprising a self-sealing valve or a non-return valve; and

an oil filter located in an interior of the oil container and in fluidic communication with the oil reservoir,

wherein the oil filter is constrained such that when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the oil reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil and gas exiting the oil filter passes through the body of oil in the oil reservoir to the headspace.

17. A method of reducing the amount of entrained gas in an oil of an oil reservoir system for an engine, which engine comprises an oil circulation system, said method comprising the steps of i) locating an oil filter in an oil reservoir within an oil container of the oil reservoir system, wherein the oil container comprises an inlet and an outlet which each independently comprise a port comprising a self-sealing valve or a non-return valve; and ii) constraining the oil filter such that, when oil is circulated by the oil circulation system of the engine, oil is forced through the oil filter and out into a body of oil in the oil reservoir, such that when oil having entrained gas flows through the oil filter, the entrained gas is separated from suspension in the oil and gas exiting the oil filter passes through the body of oil in the oil reservoir to the headspace.