FILTER ARRANGEMENT

Abstract: Filter arrangement for marine engines having an inlet (29) for coling water fitted with a filter element (33), said inlet being located beneath the surface of the water, and an outlet (29) for the cooling water. The filter element (33) covers both the inlet and the outlet (29) and is so arranged as to be capable of being displaced by means of a drive arrangement (32, 39). Those components which at a given time cover the inlet will have been caused to move after the elapse of a certain period so as to cover the outlet and will then be caused to move back to the inlet. Any impurities which may have been carried by the flow of water to the inlet and which may have settled on the filter element will be washed off in this way by the flow of water passing outwards from the outlet.

Description: Title of the Invention; Filter arrangement Technical Field: The present invention relates to a filter arrangement having a filter element for an inlet and so arranged as to be caused to be displaced by means of a drive arrangement in such a way that those components which at a given time cover the inlet will have been caused to move after the elapse of a certain period so as to cover the outlet and will then be caused to move back to the inlet, so that any impurities which may have been carried by the flow of water to the inlet and which may have settled on that part of the filter element which was covering same at the time will be washed off in this way by the flow of water passing outwards from the outlet once the part has been moved to the outlet position. Description of the prior art: The majority of marine engines are water—cooled^ For this purpose water is taken from the surrounding water for the purpose of cooling the engine either directly or via a heat exchanger. The water is then discharged, sometimes mixed with the exhaust from the engine. Technical problem: The water which surrounds the vessel in which the marine engine is installed may contain impurities, and in order to prevent such impurities from being taken into the engine or the heat exchanger, some form of filter is arranged at the inlet point. There is a risk, however, that this filter will become choked by impurities collecting on it, with the result that the engine will receive insufficient cooling. The object of the invention is to prevent such choking from taking place. OMPI < v# „ WIFO Solution: The task facing the invention is solved by causing the aforementioned inlet point to be situated beneath- the surface of the water which surrounds the vessel in which the marine engine is installed, and with the outlet for the cooling water and/or the exhaust gases from the engine also preferably being situated beneath the surface of the water, in which case the filter element will cover both the inlet and the outlet and can be moved between them. Advantages: The taking in of cooling water for the engine is assured by the invention, even in watercourses containing impurities. Description of the drawings: Two embodiments of the invention are illustrated in the accompanying drawings. Fig. 1 shows a longitudinal section along the line' I—I in Fig. 2, Fig. 2 shows a longitudinal section along the line II—II in Fig. 1, both of which relate to the first embodiment. Fig. 3 shows a view of the arrangement in accordance with the second embodiment, and Fig. 4 is a longitudinal section along the line IV-IV in Fig. 3. Description of the preferred embodiments: The fundamental concept of the invention is that the filter which is present at the inlet for the cooling water is so arranged as also to cover the outlet for the heated cooling water, in conjunction with which the filter is so arranged as to move so that those areas of it which cover the inlet will gradually be caused to move over to the outlet, in so doing being washed clean. In Fig. 1 is shown a section 1 of a drive shaft tube for a marine engine (an outboard motor or a so— alled Mnu—drev'). The drive shaft tube 1 incorporates a sleeve 2 which in an internal cavity 3 encloses a drive shaft 4 leading from the engine to the propeller, said component parts not being illustrated. As may be appreciated from Fig. 2, the drive shaft tube is of elliptical cross—section. _OMPI As may be appreciated from Fig. 1 there is present on the drive shaft tube a point 5 which is so arranged as to permit the circulation of cooling water. This component part- exhibits two edges 6 and 7 which are recessed below the outer contour 8 of the drive shaft tube. Between the edges 6 and 7 are situated four cavities 9, 10, 11 and 12 . The cavity 9 is designed to be connected to an inlet pipe for cooling water, which is shown in Fig. 1 to extend upwards from the part 5 . An outlet pipe for the cooling water is connected in a similar fashion to the cavity 11 . These pipes thus lie above the section II—II and are not visible in the Figures. The cavities 10 and 12 are not provided with any such connection, but extend only between the walls 13 and 14 to which the edges 6 and 7 are connected. The cavity 10 encloses a drive mechanism in the form of a push—rod 15 with a seal 16 and at its outer end a curved spring 17 . The push—rod 15 is so arranged as to interact with a notch 18 on the shaft 4 . The edges 6 and 7 are used to accommodate a rotating filter 20 . This consists of a relatively rigid filter cloth 21 _, to the edges of which are bonded strips 22 and 23 of soft plastic or rubber. The filter is executed in the form of a rectangle and is capable of being folded into the elliptical form shown in Fig. 2 and of being locked together by its ends by means of a snap—in closure 24 formed in the plastics or rubber material. The edges of the cloth 21 overlap each other in the joint. The second embodiment illustrated in Figs. 3 and 4 consists of a water intake arrangement which can be positioned at a . suitable point on a vessel. It is thus not connected with the engine in any way other than by those pipes or hoses which are to carry the water to and from the engine. In accordance with Fig. 3 the arrangement consists of a housing 25 with a mounting flange 26 from which project pipe stubs or hose stubs 27 for the connection of the inlet and outlet lines for the engine. There extends from the flange a body 28 of essentially drop—shaped cross—section (see Fig. 4), one approximately hemispherical end of which exhibits two cavities 29 , each of which is connected to one of the stubs 27 . Between the cavities 29 there extends a separating wall 30 , OMPI which at the cross—section 4 is executed in the form of a support with an inner bearing channel 31 for a shaft 32 . To the shaft is attached a curved, rigid filter cloth 33 of approximately hemispherical shape, The attachment_may be achieved by causing the shaft 32 and the filter cloth 33 jointly to have bonded to them a hub 34 made of plastic. So as to provide support for the edge of the filter cloth an edge part 35 is arranged on the body 28 . At the pointed part of the body is arranged- a second cavity 36. into which the shaft 32 extends. The shaft is placed under load by means of a spring 37 which ensures that the edge of the filter cloth 33 is forced against the edge part 35 - The shaft is also provided with a flange 38 which connects it to an electric motor 39 mounted inside the cavity 36 . The electric motor 39 is fitted with gearing providing a low speed of rotation. The shaft 32 is fitted with a seal 40 to prevent the ingress of water into the cavity 36 . Operation of the engine to which the drive shaft tube 1 belongs will cause the shaft 4 to rotate. This will cause the push—rod 15 to be forced outwards when it is actuated by the cam 18 Ψ The spring 17 will be imparted in this way with a movement which, at its end, will be directed essentially in parallel with that part of the edge 7 with which the spring is in contact. Once the cam 18 has passed the push—rod 15 the spring will force the push—rod inwards in such a way that it will be forced outwards again when the cam 18 passes. The movement of the spring 17 parallel with the edge 7 generates a frictional force against the edge 23 of the filter 20 . The result of this is that the filter will rotate whilst being supported by the edges 6 and 7 . The return movement of the spring 17 will not, in fact, produce the same moment through the trailing movement of the spring in that direction, and the rotation will thus occur in an anti—clockwise direction when viewed as in Fig. 2. With the engine running water will be sucked in through the filter cloth and into the cavity 9 . Water will be discharged from the cavity 11 outwards through the filter cloth. If the filter cloth, which is directly in line with the inlet at the cavity 9 becomes choked by particles, these will be washed off once the filter has covered a sufficient distance for the part concerned to have moved directly into line with the outlet at the cavity 11 , Cloths which are not choked with impurities will have moved at the same time to a position in line with the inlet, enabling the intake of water to continue unhindered.. As it moves along the elliptical track, the filter 20 will change shape in approximately the same fashion as a drive belt running over two pulleys. In the case of the embodiment in accordance with Figs. 3 and 4, water is sucked into one of the cavities 29 and is discharged from the other cavity 29 . In order to do this the water must enter via one half of the circular filter cloth 33 and must exit via the other half. The filter cloth is caused to rotate all the time with the help of the motor 39 at a slow speed. In this way any parts of the filter cloth which have become choked by impurities in the water as it arrives will be moved over to the discharge side and will be washed clean, whereupon they will be returned to the inlet side.

Claims: Patent Claims: 1. Filter arrangement having a filter element (21; 33) for an inlet (9; 29) and so arranged as to be caused to be displaced by means of a drive arrangement (17, 18; 32, 39) in such a way that those components which at a given time cover the inlet will have been caused to move after the elapse of a certain period so as to cover the outlet and will then be caused to move back to the inlet, so that any impurities which may have been carried by the flow of water to the inlet and which may have settled on that part of the filter element which was covering same at the time will be washed off in this way by the flow of water passing outwards from the outlet once the component has been moved to the outlet position, c h a r a c t e r z e d in that it is arranged for the cooling water in a water— ooled marine engine with the inlet situated beneath the surface of the water which surrounds the vessel in which the motor is installed, and with the outlet (11; 29) for the cooling water and/or the exhaust gases from the engine also preferably situated beneath the surface of the water, in which case the filter element ( 21; 33) will cover both the inlet and the outlet (9, 11; 29.) and can be moved between them. 2. Filter arrangement in accordance with Patent Claim 1, c h a r a c t e i z e d in that the filter element (21) has the form of an endless belt and in that it is so arranged as to enclose a body (2), inside which the inlet and outlet points (9, 11) are arranged, and in that the filter element is so arranged as to be displaced in a movement about said surface. 3. Filter arrangement in accordance with patent Claim 2, c h a r a c t e r i z e d in that the body constitutes part of the drive shaft tube (2) of an outboard motor. 4. Filter arrangement in accordance with Patent Claims 2 or 3„ c h a r a c t e r ! * z e d in that the belt—shaped filter element (21) is so arranged as to be displaced by means of a ratchet device (17) which is driven by means of a push— od (15) or similar from a transmission shaft (4) passing through the drive shaft tube (2). 5. Filter arrangement in accordance with Patent Claim 1, OMPI c h a r a c t e r i z e d in that the filter element (33) exhibits essentially circular form and is arranged above a corresponding fixed component in which are arranged the inlet and outlet points (29), with the filter element being fixed to a shaft (32) which is so arranged as to be caused to rotate in such a way as to impart a turning movement to the filter element over said component. 6. Filter arrangement in accordance with Patent Ctaim 5, c h a r a c t e r i z e d in that the shaft (32) is so arranged as to be driven by an electric motor (39).

Inventors: TOERNKVIST BOERJE, TOERNKVIST, BOERJE
Applicants: NP NEW PROD NORDINVENT INVEST, N.P. - NEW PRODUCTS NORDINVENT INVESTMENT AB
Application year: 1983
Main classification: B63H21
IPC codes: F01P11