Cooling systems and strainers for cooling systems for marine engines

Abstract

A cooling system is for a marine engine. The cooling system has a cooling fluid conduit that is configured to convey cooling fluid for cooling at least one component of the marine engine; a strainer disposed in the cooling fluid conduit and configured to strain the cooling fluid; and a quick connector that is manually operable to connect and disconnect the strainer from the cooling fluid conduit.

Claims

1. A cooling system for a marine engine, the cooling system comprising: a cooling fluid conduit configured to convey cooling fluid for cooling an exhaust conduit that conveys exhaust gas from the marine engine; a strainer disposed in the cooling fluid conduit and configured to strain the cooling fluid; and a quick connector that is manually operable to connect and disconnect the strainer from the cooling fluid conduit; wherein the quick connector and the cooling fluid conduit together form a first axially extending flow path for the cooling fluid, wherein the cooling fluid conduit further forms a second transversely extending flow path that branches off from the first axially extending flow path, wherein the second transversely extending flow path leads to a cooling jacket on the exhaust conduit, and wherein the first axially extending flow path leads to a sprayer for spraying a portion of the cooling fluid into the exhaust conduit.

2. The cooling system according to claim 1, wherein the marine engine is part of an outboard motor having an internal combustion engine, an upper cowling covering the internal combustion engine, and a lower cowling located below the upper cowling, and wherein the quick connector and strainer are manually accessible via removal of the upper cowling while the lower cowling remains in place.

3. The cooling system according to claim 1, wherein the cooling fluid conduit is axially elongated, and wherein the strainer is axially elongated and axially extends into to the cooling fluid conduit.

4. The cooling system according to claim 3, wherein the strainer comprises a body that has a through-bore, a first axial end that is fixed in place by the quick connector, and a second axial end that freely extends into the cooling fluid conduit.

5. The cooling system according to claim 4, wherein the cooling fluid conduit conveys the cooling fluid from upstream to downstream and wherein the second axial end of the strainer is located upstream of the first axial end of the strainer such that the second axial end faces the cooling fluid as it is conveyed from upstream to downstream.

6. The cooling system according to claim 4, further comprising at least one protrusion on the body at the second axial end, the protrusion configured for engagement with the quick connector.

7. The cooling system according to claim 6, wherein the at least one protrusion comprises a plurality of bumps that are radially spaced apart from each other around the body.

8. The cooling system according to claim 6, further comprising an annular rib at the second end, the annular rib configured for engagement with the quick connector.

9. A cooling system for a marine engine, the cooling system comprising: a cooling fluid conduit configured to convey cooling fluid for cooling at least one component of the marine engine; a strainer disposed in the cooling fluid conduit and configured to strain the cooling fluid; a quick connector that is manually operable to connect and disconnect the strainer from the cooling fluid conduit; wherein the cooling fluid conduit is axially elongated, and wherein the strainer is axially elongated and axially extends into to the cooling fluid conduit; wherein the strainer comprises a body that has a through-bore, a first axial end that is fixed in place by the quick connector, and a second axial end that freely extends into the cooling fluid conduit; wherein the cooling fluid conduit conveys the cooling fluid from upstream to downstream and wherein the second axial end of the strainer is located upstream of the first axial end of the strainer such that the second axial end faces the cooling fluid as it is conveyed from upstream to downstream; and an end cap on the second axial end.

10. The cooling system according to claim 9, further comprising a screen that extends along the body and strains the cooling fluid as the cooling fluid flows from the cooling fluid conduit into the through-bore.

11. The cooling system according to claim 10, wherein the screen is located closer to the second axial end than the first axial end.

12. A cooling system for a marine engine, the cooling system comprising: a cooling fluid conduit that is configured to convey cooling fluid for cooling a component of the marine engine and a strainer disposed in the cooling fluid conduit and configured to strain the cooling fluid; wherein the cooling fluid conduit is axially elongated and wherein the strainer is axially elongated and axially extends into to the cooling fluid conduit; wherein the strainer comprises a body having a through-bore, a first axial end that is fixed with respect to the cooling fluid conduit and a second axial end that freely extends into the cooling fluid conduit; wherein the cooling fluid conduit conveys the cooling fluid from upstream to downstream; wherein the second axial end of the strainer is located upstream of the first axial end of the strainer such that the second axial end faces the cooling fluid as it is conveyed from upstream to downstream; and an end cap on the second axial end and a screen that extends along the body and strains the cooling fluid as the cooling fluid flows from the cooling fluid conduit into the through-bore.

13. The cooling system according to claim 12, further comprising at least one protrusion on the body at the second axial end, the protrusion configured for engagement with the quick connector to thereby mate the strainer with the quick connector.

14. An outboard motor comprising: an internal combustion engine, an upper cowling covering the internal combustion engine, and a lower cowling located below the upper cowling; a cooling fluid conduit that conveys cooling fluid for cooling at least one component of the internal combustion engine; a strainer disposed in the cooling fluid conduit and configured to strain the cooling fluid; and a quick connector that is manually operable to connect and disconnect the strainer from the cooling fluid conduit, wherein the quick connector and strainer are manually accessible via removal of the upper cowling while the lower cowling remains in place; wherein the component of the internal combustion engine is an exhaust conduit that conveys exhaust gas from the internal combustion engine, wherein the quick connector and the cooling fluid conduit together form a first axially extending flow path for the cooling fluid and wherein the cooling fluid conduit further forms a second transversely extending flow path that branches off from the first axially extending flow path, wherein the second transversely extending flow path leads to a cooling jacket on the exhaust conduit, and wherein the first axially extending flow path leads to a sprayer for spraying a portion of the cooling fluid into the exhaust conduit.

15. The outboard motor according to claim 14, wherein the cooling fluid conduit is axially elongated, and wherein the strainer is axially elongated and axially extends into to the cooling fluid conduit; wherein the strainer comprises a body that has a through-bore, a first axial end that is mated with the quick connector and a second axial end that freely extends into the cooling fluid conduit when the quick connector is connected; wherein the cooling fluid conduit conveys the cooling fluid from upstream to downstream; and wherein the second axial end is located upstream of the first axial end such that the second axial end faces the cooling fluid as it is conveyed from upstream to downstream.

16. A cooling system for a marine engine, the cooling system comprising: a cooling fluid conduit that conveys cooling fluid to first and second components of the marine engine; and a strainer that strains the cooling fluid, wherein the strainer comprises a screen on an axially elongated body that extends into the cooling fluid conduit; wherein the cooling fluid conduit and strainer are configured so that a first portion of the cooling fluid flows transversely through the body via the screen and then to the first component; and wherein the cooling fluid conduit and strainer are further configured so that a second portion of the cooling fluid flows into the body via the screen and then axially along a throughbore in the body, and then to the second component.

17. The cooling system according to claim 16, wherein a first one of the first and second components is a cooling jacket on an exhaust conduit for conveying exhaust gas from the marine engine and wherein a second one of the first and second components is a sprayer for spraying the cooling fluid into the exhaust conduit.

18. The cooling system according to claim 16, further comprising a quick connector that is manually operable to connect and disconnect the strainer from the cooling fluid conduit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of an outboard motor having a cooling system according to the present disclosure.

(2) FIG. 2 is a perspective view of an exhaust conduit and a cooling water conduit that conveys cooling water for cooling the exhaust conduit.

(3) FIGS. 3 and 4 are views of a strainer disposed in the cooling water conduit and configured to strain the cooling water and a quick connector that is manually operable to connect and disconnect the strainer from the cooling water conduit.

(4) FIG. 5 is a view of section 5-5, taken in FIG. 2.

(5) FIG. 6 is an isometric view of the strainer.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 depicts an exemplary outboard motor 10 for propelling a marine vessel in a body of water. The outboard motor 10 has an internal combustion engine 12 that is supported with respect to the marine vessel via a conventional mounting arrangement associated with an underlying adapter plate 14. A driveshaft housing 16 extends below the adapter plate 14, opposite the internal combustion engine 12. The type and configuration of internal combustion engine 12 can vary from what is shown. In the illustrated example, the internal combustion engine 12 has a V-shape which discharges exhaust gases inside of the V-shape to a centrally located exhaust conduit 22. The internal combustion engine 12 and exhaust conduit 22 are configured in the manner disclosed in the above incorporated U.S. Pat. No. 9,616,987. Briefly, combustion within the internal combustion engine 12 creates exhaust gas, which is centrally conveyed into the valley of the V-shape and then directed upwardly and then downwardly through an exhaust manifold and elbow portion 21 of the exhaust conduit 22. The exhaust conduit 22 conveys the exhaust gas downwardly from the elbow portion 21 to the adapter plate 14. The exhaust gas is ultimately discharged from the outboard motor 10 via a conventional underwater exhaust outlet. FIG. 1 also schematically depicts an upper cowling 18 covering the internal combustion engine 12 and related components and a lower cowling 20 covering the driveshaft housing 16 and related components. The upper cowling 18 is located above the lower cowling 20. The shape and configuration of the upper and lower cowlings 18, 20 can vary.

(7) FIGS. 1 and 2 also depict portions of a cooling system for cooling certain components of the internal combustion engine 12, including for example the above-noted exhaust conduit 22. A pump 28 is configured to pump cooling fluid (e.g., relatively cold water from the body of water in which the outboard motor 10 is operating) to the internal combustion engine 12 via a cooling fluid conduit (i.e., a cooling water conduit) 26. The pump 28 is shown schematically in FIG. 2 and can include any type of conventional pump device for pumping cooling fluid, including for example a mechanical pump powered by the driveshaft of the internal combustion 12 or an electrical pump powered by a battery associated with the outboard motor 10. In the illustrated example, the pump 28 is configured to pump cooling water from a conventional underwater inlet on a lower portion of the outboard motor 10. The conventional underwater inlet is not shown in FIG. 2 however one suitable configuration is disclosed in the incorporated U.S. Pat. No. 8,540,536. Typically the underwater inlet is located in the gear case housing of the outboard motor, below the anti-cavitation plate 25 shown in FIG. 1. Reference is made to the '536 patent, showing one example. The pump 28 pumps the cooling water upwardly to the internal combustion engine 12 via the cooling water conduit 26, as shown by arrows in FIGS. 2 and 5. For further background information, the '536 patent also discloses conveyance of the cooling water to an internal combustion engine, as well as an exhaust system for conveying exhaust gas from the internal combustion engine, via cooling water conduits.

(8) Referring to FIGS. 2 and 5, the pump 28 pumps the cooling water via the cooling water conduit 26 to a cooling water jacket 30 disposed on the exhaust conduit 22. As the relatively cold cooling water is pumped vertically upwardly through the cooling water jacket 30, it naturally exchanges heat with the relatively hot exhaust conduit 22 and thus also the relatively hot exhaust gas flowing downwardly there through. See e.g. the dashed arrows in FIG. 5. Reference is also made to the above-incorporated U.S. Pat. No. 8,540,536 for further details regarding prior art cooling systems having an exhaust conduit and a cooling water jacket disposed thereon and configured for heat exchange with relatively hot exhaust gas flowing there through. As is conventional, the cooling water flows from upstream to downstream through the cooling water jacket 30, under pressure from the pump 28, and is then routed to the internal combustion engine 12 for further heat exchange with components thereof, including for example the cylinder heads, cylinder block, etc. Once the cooling water has completed its path through the cooling system, it typically is discharged back to the body of water in which the outboard motor 10 is operating via for example an underwater outlet on the outboard motor 10.

(9) It is known in the art to provide one or more strainers in the above-described cooling system to strain solid/particulate material of a certain size from the cooling water. In use, prior art strainers can unfortunately become clogged, especially when the outboard motor is operated in a body of water having high debris content. When the strainer becomes clogged, the cooling functionality of the system is compromised and the internal combustion engine is put at risk of overheating. Thus, it is typically recommended that the operator of the outboard motor routinely service the strainer(s). The strainer(s) should be routinely checked for clogs and any other problems. However the present inventors have found that this process can be especially challenging and cumbersome because prior art strainers are usually located below the adapter plate, under the lower cowling. Access to a plugged strainer usually requires the operator or service technician to remove the lower cowling and then remove other connection features associated with the strainer (e.g. fasteners, brackets, etc.).

(10) The present disclosure is a result of the present inventors' efforts to provide cooling systems and strainers for cooling systems that are both more effective and easier to service.

(11) Referring to FIGS. 4-6, according to the present disclosure, a strainer 34 is disposed in the cooling water conduit 26 at a location above the adapter plate 14. Referring to FIGS. 2-6, the strainer 34 is easily accessible by the operator, requiring only removal of the upper cowling 18 and removal of a quick connector 36 that connects the strainer 34 to the cooling water conduit 26. The quick connector 36 is manually operable to allow the operator to easily connect and disconnect the strainer from the cooling water conduit 26 without the need for tools. As explained further herein below, the strainer 34 is also uniquely configured to more efficiently strain the cooling water flowing into the exhaust conduit 22 and the cooling water flowing into the cooling water jacket 30, as compared to the prior art, and is also less likely to clog. Other advantages and improvements over the prior art will be apparent from the following description of the drawings.

(12) As shown in FIG. 5, the cooling water conduit 26 includes an elbow fitting 37 that has a first outlet port 39 attached to an inlet boss 41 on the cooling water jacket 30. An O-ring seal 47 is disposed between the elbow fitting 37 and the inlet boss 41 so as to form a fluid tight seal there between. The elbow fitting 37 further includes an inlet port 43 that receives cooling water from the pump 28 via a flexible hose 45. The flexible hose 45 is clamped to a barb 49 on the inlet port 43 so as to form a fluid tight seal there between. The elbow fitting 37 also has a second outlet port 51 to which the strainer 34 is connected by the quick connector 36.

(13) The cooling water conduit 26 and the quick connector 36 define a first axially extending flow path 38 for the cooling water. The cooling water conduit 26 further defines a second, transversely extending flow path 40 that transversely branches off from the first axially extending flow path 38. The first axially extending flow path 38 extends through the elbow fitting 37 and quick connector 36 to a flexible connection hose 53, which leads to an exhaust sprayer 32 configured to spray cooling water into the exhaust conduit 22 for mixing with and cooling the exhaust gas flowing downwardly there through. The second transversely extending flow path 40 leads to the cooling water jacket 30 on the exhaust conduit 22.

(14) Thus, as shown by arrows in FIG. 5, a first portion of the cooling water flows upwardly along the first axially extending flow path 38, through the strainer 34, and on to the exhaust sprayer 32 via the connection hose 53. A second portion of the cooling water flows through the strainer 34 and then transversely along the second transversely extending flow path 40. The second portion of the cooling water generally includes cooling water flowing on the radially outer side of the inlet port 43, diametrically opposite the cooling water jacket 30. A shoulder 57 is formed on the radially outer side of the inlet port 43 so as to transversely redirect the second portion of the cooling water along the second transversely extending flow path 40, through the strainer 34, and then into the first outlet port 39. A third portion of the cooling water that generally consists of cooling water flowing along the radially inner side of the inlet port 43, bypasses the strainer 34, and then flows through the second, transversely extending flow path 40.

(15) As shown in FIG. 5, the strainer 34 axially extends into the cooling water conduit 26 along the first axially extending flow path 38. Referring to FIGS. 5 and 6, the strainer 34 includes a body 42 that has a through-bore 44, a first axial end 46 that is mated with the quick connector 36 and a second axial end 48 that freely extends into the cooling water conduit 26. As shown in FIG. 5, the cooling water conduit 26 conveys the cooling water from upstream to downstream and the second axial end 48 is located upstream of the first axial end 46, such that the second axial end 48 faces the cooling water as it is conveyed. Referring to FIG. 6, an end cap 50 is disposed on the second axial end 48 of the strainer 34. A filter or screen 52 extends along the body 42 and is configured to strain the cooling water as it flows from the cooling water conduit 26 into the through-bore 44 in the body 42. The screen 52 is located closer to the second axial end 48 than the first axial end 46. A plurality of bumps 54 extend radially outwardly from the body 42 and are spaced apart around the body 42 at the first axial end 46. An annular rib 56 is formed at the first axial end 46. The bumps 54 and annular rib 56 are configured for engagement with the second outlet port 51 and quick connector 36, respectively, as further described herein below.

(16) The configuration of the quick connector 36 can vary from what is shown in the drawings. Referring to FIG. 5, the illustrated example is a SAEJ2044 Quick Connect Fitting, which for example is commercially available from Parker Hannifin. The quick connector 36 is manually operable to easily connect and disconnect the strainer 34 from the cooling water conduit 26 and from the quick connector 36. The quick connector 36 includes an elongated body 60 having a through-bore sized to fit onto the outer diameter of the second outlet port 51 of the elbow fitting 37. The quick connector 36 has a retention ring 62 with an inner diameter that is sized slightly smaller than the outer diameter of an annular ring 64 on the second outlet port 51. As shown by an arrow in FIG. 3, the retention ring 62 is manually deformable by pressing on the outer surface thereof. Manually deforming the retention ring 62 changes the dimensions of its inner diameter so as to free the quick connector 36 for axial removal from the second outlet port 51. That is, the retention ring 62 is able to pass over the annular ring 64 when the retention ring 62 is manually pressed. See FIG. 4.

(17) The quick connector 36 can be manually re-connected to the second outlet port 51 by re-inserting the strainer 34 into the second outlet port 51 and axially moving the quick connector 36 downwardly onto the second outlet port 51, until the retention ring 62 is forced to deform over the outer diameter of the annular ring 64. The natural resiliency of the retention ring 62, which can be made of plastic, causes it to snap back into its natural shape once it axially passes by the retention ring 62, thus engaging with the second outlet port 51 in a snap-fit manner. An inner O-ring seal 63 is configured to seal with the outer diameter of the second outlet port 51. The bumps 54 on the outer diameter of the body 42 of the strainer 34 are configured to engage in a press-fit connection with the inner diameter of the second outlet port 51.

(18) Referring to FIGS. 3-6, the quick connector 36 facilitates quick and easy checking and maintenance of the strainer 34, including to removal any clogs or other debris. FIG. 3 depicts the quick connector 36 in a connection position on the second outlet port 51. When the retention ring 62 is manually engaged and deformed, the body 60 is removable from the second outlet port 51, as described above and shown in FIG. 4. When the body 60 of the quick connector 36 is manually withdrawn from the second outlet port 51, the strainer 34 will tend to remain seated in the second outlet port 51 due to the frictional engagement between the bumps 54 and the inner diameter of the second outlet port 51. As the body 60 of the strainer 34 is removed, the annular rib 56 on the first axial end 46 of the strainer 34 is engaged by an inner mantle piece 55 on the quick connector 36, which pulls the strainer 34 out of the second outlet port 51 along with the quick connector 36, overcoming the frictional engagement between the bumps 54 and the inner diameter of the second outlet port 51. The inner mantle piece 55 is sized just slightly larger than the annular rib 56 so that the engagement there between is strong enough to pull the strainer 34 out of engagement with the second outlet port 51. However the engagement between the inner mantle piece 55 and annular rib 56 can be configured so that it can be overcome by a stronger manual force, i.e. manually pulling the strainer 34 out of the body 60 of the quick connector 36. That is, the inner mantle piece 55 and/or the annular rib 56 are made of a resilient material such as plastic, which will slightly deform under a sufficient manual separating force. This allows separation of the strainer 34 from the quick connector 36 after the quick connector 36 has been removed from the second outlet port 51, thus facilitating cleaning and/or repair of both components.

(19) The location of the strainer 34 on the outboard motor 10 and the configuration of the quick connector 36 advantageously provide the operator with an accessible arrangement that does not require tools or fasteners for assembly and disassembly. The inline configuration of the strainer facilitates improved flow area and straining functionality over the prior art, thus improving performance. The shape of the strainer and orientation of the strainer in the cooling water conduit is less restrictive for water flow, as compared to the prior art, and also facilitates self-cleaning during shutdown of the internal combustion engine. Large debris is less likely to get stuck on the strainer because of its axial (inline) orientation with the flow of water. Large debris will tend to deflect off of the closed end cap 50, without getting stuck. This configuration can also be easily inspected without removal of the lower cowling. In certain examples, the second outlet port 51 of the elbow fitting 37 can be made of transparent material (e.g. plastic), thus allowing for easier visual inspection without requiring removal of the quick connector 36 from the second outlet port 51.

(20) In the present description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different apparatuses described herein may be used alone or in combination with other apparatuses. Various equivalents, alternatives and modifications are possible within the scope of the appended claims.