Patent GB-1382992-A (GB)
Title: Internal combustion engine lubricating oil cooling system
IPC: F01M5/00
Filed: 1971-02-16
Abstract: 1382992 Bearings; valves GEC DIESELS Ltd 16 Feb 1972 [16 Feb 1971] 4707/71 Headings F2A and F2V A valve assembly for use in the lubrication system of an internal combustion engine has a relief and by-pass valve located in a single housing 40. The lubrication system comprises a sump 20 from which oil is pumped via a filter 21 by either an engine driven pump 22 or an auxiliary pump 23 through non-return valves 24, which may also be located in the valve housing 40, to either a heat exchanger 19 or a by-pass valve 31 and thence via a filter 25 to the engine 26 from which it returns to the sump 20. A relief valve 28 is provided to limit the pressure in the system. The oil is cooled in the heat exchanger by circulating water. The valve assembly comprises a valve body 40 having one passage 54 which communicates with a second passage 56 via a valve port 34 surrounded by a valve seat 60 which in turn communicates with a third passage in the body by way of a second valve port surrounded by a second seat 69. Bores are provided in the body corresponding to each valve port in which are slidably mounted valve members which are resiliently urged into the valve seats, thereby interrupting the communication between the passages. Each valve member has a surface which is exposed to fluid in the first and second passages respectively whereby the fluid pressure may overcome the resilient bias and unseat the valve members. Each passage has a port for external connection of the assembly. The degree of resilient biasing may be varied by means of screws 62, 75 which move caps 61, 74 which engage the springs 33, 29. Lubricant being pumped by the pumps 22, 23 enters the valve assembly through ports 46 and 52 and forces valve members 47, 50 against a spring 51 from their seats allowing the lubricant to pass into passages 53 and 54 in the body. From passage 53 the lubricant passes from the body to the heat exchanger and thence either to the engine or via port 55 back into the second passage 56 of the body from which it may act on the valve member 57 to urge it to remain closed, or the member 68 to urge it to open. As the lubricant pressure increases due, e.g. to increasing speed of the engine, value 28 is caused to open, thereby allowing lubricant to return via port 30 to the sump, and limiting the pressure in passage 56. If the pressure of lubricant isssuing from the pumps increases further, the pressure in passage 54 increases until valve 34 opens allowing lubricant to flow into the passage 56 and thence to the engine by-passing the heat exchanger. The cooling system for the lubricant may be part of the engine cooling system, the engine coolant (e.g. water) which is supplied to the engine cylinder jackets 11 passing through the cylinder heads to a thermostatically controlled diversion valve 13 which except when the coolant is cold directs at least part of the flow through a heat exchanger where it is cooled by air or water. The coolant is then pumped through the heat exchanger 19 where it cools the lubricant and passes back to the engine. A header tank 18 may be provided.