Abstract:
The invention includes an oil system vent that is remote from an oil reservoir so that the oil reservoir can be stored in the bilge section of a boat. The oil reservoir has an oil supply outlet and an oil supply return. The oil reservoir is constructed without a ventilation means attached thereto. The oil system vent includes an oil return port having an oil input and an oil output. The oil input receives pressurized lubricant and the oil output returns the pressurized lubricant to the oil supply return of the oil reservoir. The oil return port has a vent port in communication with atmospheric pressure so that when lubricant is drawn and used from the oil reservoir, the vent port allows air to displace the used lubricant in the oil reservoir. The oil reservoir is positioned at a relatively low elevation, in the bilge section of the boat, and the vent port is positioned at a relatively high elevation with respect to the outboard motor.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to oil systems for internal combustion engines, and more specifically, to an oiling system for a two-stroke engine in an outboard motor having an oil reservoir remote from the oil system vent. 
     Typically, two-stroke outboard marine engines do not have a separate oiling system. That is, these prior art engines require pre-mixing lubricant and fuel so that the lubricant dissolves in the fuel to lubricate the engine. This requires consistent, accurate measuring and agitation of the mixture. There are many disadvantages to the prior art system of pre-mixing lubricant and fuel. For example, since various two-stroke engines require different mix concentrations, many outboard marine engine owners also own other two-stroke engine equipment, such as various lawn and garden equipment and ATV&#39;s, they may store several different concentrations of oil/fuel mixture. This is not only an aggravation to the owner, but is also problematic if the containers become mixed up and the owner uses the wrong concentration for a particular two-stroke engine. While this is not catastrophic, if run over time with the wrong concentration, a two-stroke engine can wear excessively. 
     The present invention is for use in a unique lubrication system for two-stroke engines. Such a lubrication system must provide lubrication to each cylinder of the engine and provide lubrication to the fuel system to properly lubricate the fuel metering and injection system from an oil reservoir. 
     It is desirable in such systems to place the oil reservoir in the bilge section of the boat. However, since such prior art oil reservoirs have a vent located directly on the oil reservoir, and often in the cap on the top of the reservoir, water in the bilge section of the boat can be ingested into the tank through the vent. That is, as oil in the tank is consumed, the volume must be displaced, and is usually displaced with air from the vent. While occasionally the oil reservoir may become submerged in water and the water can be directly ingested into the oil reservoir by the vacuum created by the oil consumed, water may also be consumed if the oil reservoir is not completely submerged, but only subjected to the normal use of the boat in which water splashes on the oil reservoir thereby allowing ingestion of air and water. Since water will sink to the bottom of the tank and the oil will float on top of the water due to their relative densities, and since oil is often drawn from the bottom of the tank to maximize volume of the tank, the oiling system can draw water in place of oil if the water level reaches the oil pickup. Water in place of oil, or water mixed with oil, can severely damage an engine. 
     It would therefore be desirable to have an oiling system that could accommodate a completely sealed oil reservoir that may be located in the bilge of the boat, and may be susceptible to complete submersion. 
     SUMMARY OF THE INVENTION 
     The present invention includes a ventless oil reservoir and a remote oil system vent for an outboard motor that solves the aforementioned problems. 
     In accordance with one aspect of the invention, an oil system vent for an outboard motor includes an oil reservoir having an oil supply outlet and an oil supply return. The oil reservoir is designed to be located below the water line of a boat, and in particular, in the bilge area of the boat. The oil reservoir is free of any internal ventilation means such that the oil reservoir can be completely submerged in water, and as long as the cap is secured tightly, water will not enter the oil reservoir, even when the oil reservoir is under a slight vacuum. The oil system vent includes an oil return port having an oil input and an oil output. The oil input receives pressurized lubricant and the oil output and returns the pressurized lubricant to the oil supply return of the oil reservoir. The oil return port also has a vent port that is in communication with atmospheric pressure when lubricant is drawn and used from the oil reservoir. In this manner, the vent port allows air to displace the used lubricant in the oil reservoir. 
     In accordance with another aspect of the invention an oil system for a two-stroke engine includes a ventless oil reservoir having a pump associated therewith to draw and pump lubricant therefrom. A closed loop in an oil routing system of the oiling system includes the ventless oil reservoir and pump, and also includes a pressure regulator and a solenoid valve. The solenoid valve is positioned in the closed loop to periodically open the closed loop and divert lubricant to the two-stroke engine. A remotely located vacuum controlled vent valve is located in the closed loop to allow air into the closed loop when the solenoid valve periodically diverts lubricant to the two-stroke engine. 
     Another aspect of the invention includes a boat and outboard motor combination that includes an outboard motor mounted to the transom of a boat and further includes a ventless oil reservoir located in the boat that does not allow water ingestion even when completely submersed in water. The combination includes an oiling system having a pump to draw lubricant from the ventless oil reservoir and route the lubricant through the oiling system and back to the ventless oil reservoir. The oiling system periodically diverts the lubricant to the engine of the outboard motor. The combination also includes a remote ventilation means for venting the ventless oil reservoir while lubricant is periodically diverted to displace used lubricant with air to avoid excessive vacuum in the oil reservoir. 
     The invention also includes a method of venting an oil reservoir of an outboard motor that includes providing a ventless oil reservoir and routing lubricant from the ventless oil reservoir through an oil pump, to an oil system, and back to the ventless oil reservoir in a closed loop. The method includes periodically opening the closed loop in the oil system to draw and use lubricant from the ventless oil reservoir. A vent valve is provided at a higher elevation than the ventless oil reservoir. The vent valve automatically opens when lubricant is consumed to displace the consumed lubricant with air within the ventless oil reservoir. 
     Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention. 
     In the drawings: 
     FIG. 1 is a perspective view of an oiling system for a two-stroke outboard marine engine. 
     FIG. 2 is a schematic illustration of an oiling system in accordance with one aspect of the present invention. 
     FIG. 3 is a left side, elevational view of the oiling system of FIG. 1 connected to an ECU of an outboard motor. 
     FIG. 4 is a front elevational view of the oiling system of FIG. 1 shown connected to an ECU and oil tank for an outboard motor. 
     FIG. 5 is a top plan view of the oiling system of FIG.  4 . 
     FIG. 6 is a partial cross-section of the oiling system taken along line  6 — 6  of FIG.  5 . 
     FIG. 7 is a cross sectional view taken along line  7 — 7  of FIG.  5 . 
     FIG. 8 is a partial cross-sectional view taken along  8 — 8  of FIG.  5 . 
     FIG. 9 is a partial cross-sectional view taken along line  9 — 9  of FIG.  5 . 
     FIG. 10 is a partial cross-sectional view taken along line  10 — 10  of FIG.  5 . 
     FIG. 11 is a partial cross-sectional view taken along line  11 — 11  of FIG.  4 . 
     FIG. 12 is a schematical illustration of the oiling system shown in FIGS. 1-10 incorporated into an outboard motor and boat combination. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, an oiling system  10  is shown, preferably for a two-stroke engine of an outboard marine motor. The oiling system  10  includes an oil system housing  12  having an oil inlet  14  connected to a supply line  16 . The oiling system housing  12  also includes an oil outlet  18  that supplies oil to a distribution manifold  20 . A separate oil return  22  is provided through a tee-connector  24  connected to the oil system housing  12  and a return line  26  to return unused oil to an oil reservoir. The tee-connector is also connected to a vent valve  28  that is open on one end  30  to atmospheric pressure. 
     The oil system housing  12  is mounted to an engine with mounting bolts  32 ,  34  and is constructed to receive a full flow, replaceable oil filter  36  on an oil filter base  38  to filter incoming pressurized oil from supply line  16  through oil inlet  14 . The pressurized oil is then routed through internal passages to an oil flow control section  40  of the oil system housing  12 . The oil flow control section  40  is controlled by a solenoid (not shown in FIG. 1) that controls whether oil flows through the oil outlet  18  and distribution manifold  20  or through the oil return  22  and return line  26 . The oil system housing  12  also includes a test port  48  that is in fluid communication with an output side of the replaceable oil filter  36  to measure oil pressure during operating conditions. The housing  12  also includes a sensor chamber  42  to receive an oil pressure sensor  64  therein. 
     Referring to FIG. 2, a schematic representation of an oiling system  10  in accordance with the present invention is illustrated. The oil system includes an oil tank/reservoir  50  having an oil pump  52  associated therewith to pump oil through supply line  16  and filter  36 . In a preferred embodiment, as shown in FIG. 2, the oil pump  52  is located inside the oil tank  50 . After the oil is filtered, it is routed through an internal passage  54  of the oil system housing  12  to the oil flow control section  40  wherein the flow of oil is controlled by operation of solenoid  44 , which in turn is controlled by an electronic control unit (ECU)  56 . As previously indicated, the solenoid  44  toggles the flow of lubricant from internal passage  54  to internal passages  58  and  60 . When the solenoid  44  is not activated, the normally open position  61  relays oil from the internal passage  54  to the internal passage  60  of the oil system housing  12  through an internal pressure regulator  62  and returns unused oil to the oil reservoir  50 . 
     When solenoid  44  is activated, the flow of oil is diverted to internal passage  58  to supply oil to the distribution manifold  20 . A pressure sensor  64  is in fluid communication with the lubricant in internal passage  58  to monitor the lubricant pressure and provide an oil pressure signal  66  to the ECU  56 . The distribution manifold  20  includes an internal check valve  68  to prevent the backflow of oil in the oil system  10 . The distribution manifold  20  has a number of cylinder oiling outlets  70  that coincide with a number of cylinders of an engine  72 , and each oiling outlet  70  is connected to a cylinder of engine  72 . The distribution manifold  20  also includes a fuel system oiling outlet  72  to supply lubricant to the fuel system  74 , preferably, to lubricate a fuel injection distribution system, and purge air from the oil system through a fuel separator in the fuel system  74 . 
     The oil reservoir  50  of oil system  10  includes an oil supply outlet  76  and an oil supply return  78  and is free of any internal ventilation mechanism. In this manner, the oil reservoir  50  can be completely submerged in water, and as long as the fill cap is properly closed, water cannot enter the oil reservoir. 
     When solenoid  44  is not activated, a closed loop  80  is formed in the oil routing system between the ventless oil reservoir  50 , the filter  36 , the oil flow control section  40 , through internal passage  60 , and the oil return  22 . As long as no oil is withdrawn from the reservoir, by the activation of solenoid  44 , the oil circulates through the closed loop  80 . However, when the loop is open by solenoid  44  to divert lubricant from internal passage  60  to internal passage  58  in the oil flow control section  40 , oil is then consumed in the engine  72  and the fuel system  74 . This consumption of oil must be displaced or the oil reservoir  50  will come under an increasing negative pressure. Accordingly, the vent valve  28  is coupled to the closed loop  80  at one end of the tee-connector  24  at the oil return  22 . Vent valve  28  is a vacuum controlled vent valve and includes a check valve  82  that preferably opens at approximately 3″ of H 2 O to allow air to displace the consumed oil in the oil reservoir  50  when the solenoid valve  44  periodically diverts lubricant to engine  72 . The vent valve  28  also includes a filter  84  to filter contaminates that may be drawn from the atmosphere  86 . 
     Accordingly, a method of venting an oil reservoir  50  of an outboard motor is disclosed that includes providing a ventless oil reservoir, routing lubricant from the ventless oil reservoir  50  through an oil pump  52 , to an oil system  10  and back to the ventless oil reservoir  50  in a closed loop  80 . The method includes periodically opening the closed loop  80  in the oil system  10  to draw unused lubricant from the ventless oil reservoir. The method also includes providing a vent valve  28 , remote from the ventless oil reservoir  50 , and at an elevation higher than that of the ventless oil reservoir. The vent valve then automatically opens when lubricant is consumed to displace the consumed lubricant with air in the ventless oil reservoir. 
     Referring to FIG. 3, a left side view of the oil system  10  and the oil system housing  12  of FIG. 1 shows the ventilation system  88 , the distribution manifold  20 , and the solenoid  44  and the pressure sensor  64  connected to the ECU  56  by lead wires  45 ,  65 . The distribution manifold  20  is mounted to the housing  12  over the oil outlet  18  by mounting bolts  90 . When oil is diverted by solenoid  44 , it is routed through oil outlet  18  to a plurality of cylinder outlet housings  92  and a fuel system oiling outlet housing  94 , each of which is equipped with a push-to-connect fitting  96  to allow quick connection and disconnection of the oiling lines that extend to each cylinder and the fuel system. As is indicated in FIG. 3, the fuel system oiling outlet housing  94  is at a higher elevation than each of the cylinder oiling outlets  92  to purge any air from the oiling system through a fuel separator in the fuel system. 
     The ventilation system  88  preferably includes a diaphragm vent valve  28 . The vent valve  28  includes two ends  98 ,  100 , wherein a first end  98  is in communication with the oil return  22  via the tee-connector  24  of the oil system housing  12 . The second end  100  is open to the atmosphere  86  to draw air therefrom when solenoid  44  is activated by ECU  56 . 
     FIG. 4 shows a front elevational view of the oiling system  10  of FIG. 1 connected schematically to the closed loop default flow path  80 . As indicated, lubricant is pumped from the oil reservoir  50  by pump  52  and circulates through the closed loop system  80  all the while that solenoid  44  is not activated by the ECU  56 , which also controls the oil pump  52 . In this manner, oil is circulated from the oil reservoir  50  through the oil inlet  14 , through the replaceable oil filter  36  and is routed in the oil flow control section  40  to the oil return  22 , out the tee-connector  24 , and back to the oil reservoir  50 . When the solenoid  44  is activated by the ECU  56 , oil is then diverted from the oil return  22  to the oil outlet  18  and out the distribution manifold  20  to each of the engine cylinders and the fuel system. As oil is consumed, the oil reservoir comes under a negative pressure and draws air through the ventilation system  88 . 
     According to one aspect of the invention, the aforementioned system is incorporated into a two-stroke engine of an outboard motor that includes the oil system housing  12  having an oil filter base to replaceably receive an oil filter  36  thereon such that lubricant in the closed loop system  80  can be continuously filtered, and filtered before consumption by the two-stroke engine. 
     FIG. 5 shows a top plan view of the oiling system  10  of FIGS. 1,  3  and  4 . FIG. 5 shows a top view of the distribution manifold  20  and the diaphragm vent valve  28 . FIG. 5 is used to illustrate the cross-section views for FIGS. 6-10 that illustrate the oil flow paths through housing  12 . 
     Referring to FIG. 6, oil is first introduced into the oil inlet port  14  through a first internal passage  102  and is then introduced into the full flow, replaceable oil filter  36 . The oil filter is mounted to the oil filter base  38  and sealed therebetween with gasket  104 . Oil is introduced into filter  36  through a plurality of openings  106 , is filtered in element  108  and discharged through center opening  110 . As shown in FIG. 7, once discharged through center opening  110 , the oil enters a second internal passage  112  and is routed to the oil flow control section  40 . 
     The test port  48  is in fluid communication with the second internal passage  112  and is equipped with a Schraeder valve  114  to test the oil pressure on the back side of filter  36 . The Schraeder valve  114  thus provides a point to acquire an accurate reading of the oil pressure as it is presented through the system. 
     As indicated by arrow  116 , oil is then routed to a third internal passage  118  when solenoid  44  is not activated. Solenoid  44  includes an internal plunger  120 , magnet  122  and return spring  124  and is constructed in a known manner. The oil flow control section  40  includes a check ball  126  and a pressure spring  128  which moves downwardly when the solenoid is activated, which pulls plunger  124  downwardly and closes the oil path indicated by arrow  116  when oil is diverted to the engine. 
     Referring now to FIG. 8, the return oil path through solenoid  44  is shown. The oil return port  22 , which includes the tee-connector  24 , is in fluid communication with the third internal passage  118  through a pressure regulator  62 . The pressure regulator  62  includes a check ball  130  and pressure spring  132  to regulate the oil pressure in the oil system at a desired level. The tee-connector  24  includes a relatively narrow air inlet passage  134  that is connected with a hose  136  to the vent valve  28 . The vent valve  28  includes air filter  84  and check valve  82 , which in turn includes a diaphragm  138  and return spring  140 . The vent valve  28  is connected to an L-shaped extension hose  142  at its second end  100  to draw air from the atmosphere  86  to displace consumed oil, as previously described. FIG. 8 also shows a more detailed view of solenoid  44  in which plunger  120  is drawn downward when the magnet  122  is energized. The return spring  124 , which is positioned between a stationary block  144  and a shoulder  146  of the plunger  120 , causes the plunger to return to its upward position when the magnet  122  is de-energized. An extension shaft  148  is positioned within the plunger  120  and extends upward to support the check ball  126  against pressure spring  128  to maintain oil flow around the check ball  126  along the third internal passage  118 . 
     FIG. 9 shows the solenoid  44  in its actuated position with the plunger  120  drawn downwardly within the magnet  122 . In this position, the return spring  124  is compressed and the pressure spring  128  is extended causing the check ball  126  against seat  150  which closes oil flow through the third internal passage  118 . In this position, oil is routed through a fourth internal passage  152 , which is in communication with the pressure sensor  64 . Pressure sensor  64  is threadedly engaged in housing  12  and is constructed in a known manner having a pressure diaphragm  154  connected to a pair of contacts  156  that operate to close an electrical path between contact leads  158  which are connected to the ECU. The fourth internal passage  152  is also in fluid communication with the oil outlet  18  of FIG. 10 to supply oil to a number of passages  160  in the distribution manifold  20  to supply oil to the cylinder outlet housings  92  and then to each cylinder of the two-stroke engine. Oil is also supplied by oil outlet  18  to passage  162 , FIG. 9, to supply oil through the fuel system oiling outlet housing  94  which leads to the fuel system. Internal passage  162  is at the highest point to purge any air from the oil system. 
     FIG. 11 shows a cross-section of the distribution manifold  20  taken along line  11 — 11  of FIG. 4 showing the distribution manifold mounted to the oil system housing  12 . The cross-section shows oil outlet  18  opening into a D-shaped domed chamber  166  that feeds oil to each of the passages  160  equally. Each of the passages  160  include a check valve  164  within the cylinder outlet housings  92 , and each of the outlet housings  92  include a push-to-connect fitting  96 , such as the Legris Carstick® fitting made by Legris, Inc. Since the fuel system outlet housing  94  is at a higher elevation than the other outlet housings  92 , the upper passageway is not shown. However, passageway  162  for the fuel system outlet housing  94  is at the highest elevation to intersect with a high point of the dome chamber  166 . As previously described, this allows any air in the oil system to purge through outlet housing  94  which leads to the fuel system, and once in the fuel system, the air is purged through a fuel separator. 
     FIG. 12 shows an operating environment for the present invention herein described. However, it will be appreciated by those skilled in the art that the present invention is equally applicable for use with other types of engines and applications. FIG. 12 shows an outboard motor  170  having a power head  172  enclosed in an upper cowl  173 , a midsection  174 , and a lower gear case  176 . The outboard motor  170  is mounted to a transom  178  of a boat  180  by a transom mounting bracket  182 . The outboard motor  170  includes a propeller  184  extending rearward from the lower gear case  176  to propel the boat  180  through the water. The powerhead  172  includes a two-stroke internal combustion engine  186  controlled by the ECU  56 . A fuel tank  188  supplies fuel to the fuel system  190  through a pickup line  192 , as is known. 
     As described with reference to FIG. 2, the oil reservoir  50  pumps oil via pump  52  to the inlet  14  and after filtering through filter  36 , the oil is re-circulated through the closed loop  80  until the solenoid  44  is activated by the ECU  56  which diverts lubricant to each of the cylinders  194  and the fuel system  190 . As lubricant is withdrawn and consumed from the oil reservoir  50 , vent  28  cracks open to intake air and displace the oil consumed in the reservoir  50 . Preferably, the oil reservoir is located in a bilge section  196  of the boat  180 , which is below the water line  198 . It is also preferred that the open end  30  of the vent valve  28  is at an elevation well above the water line  198  to avoid the introduction of water into the oil reservoir  50 . 
     Accordingly, the present invention also includes a method of venting an oil reservoir of an outboard motor that includes providing a ventless oil reservoir, routing lubricant from the ventless oil reservoir through an oil pump to an oil system, and back to the ventless oil reservoir in a closed loop. The method next includes periodically opening the closed loop in the oil system to draw and use lubricant from the ventless oil reservoir. The method provides a vent valve remote from the ventless oil reservoir at an elevation higher than that of the ventless oil reservoir. The vent valve automatically opens when lubricant is consumed to displace the consumed lubricant with air in the ventless oil reservoir. 
     The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.