The present disclosure relates to outboard motors and more particularly to apparatuses for lubricating cranktrains of outboard motors.
The following U.S. patents are incorporated herein by reference:
U.S. Pat. No. 9,616,987 discloses a marine engine including a cylinder block having first and second banks of cylinders that are disposed along a longitudinal axis and extend transversely with respect to each other in a V-shape so as to define a valley there between. A catalyst receptacle is disposed at least partially in the valley and contains at least one catalyst that treats exhaust gas from the marine engine. A conduit conveys the exhaust gas from the marine engine to the catalyst receptacle. The conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to the catalyst receptacle. The conduit reverses direction only once with respect to the longitudinal axis.
U.S. Pat. No. 7,198,019 discloses a lubricating system for a marine engine having a lubrication deflector which extends from the cylinder block of the engine toward rotating surfaces of a crankshaft and/or connecting rod. A lubrication passage is provided as an integral part of a cylinder block of the outboard motor to direct a flow of liquid lubricant away from the lubrication deflectors and downwardly toward a lubrication reservoir, or sump.
This Summary is provided to introduce a selection of concepts that are further described herein below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting scope of the claimed subject matter.
An outboard motor comprises an engine block having vertically-aligned first and second banks of cylinders that extend from each other in a V-shape, a vertically-extending central drain passage located below the first bank of cylinders and configured to drain lubricant to an underlying sump, a vertically-extending crankshaft, and a central deflector located between the first and second banks of cylinders. The central deflector extends from the engine block towards the crankshaft and is configured to deflect lubricant away from the crankshaft to the central drain passage.
Each bearing 24 has several lubricant passages (not all are shown, e.g. see 26) for conducting lubricant from an underlying sump to the interior of the crankcase, for lubricating the crankshaft 18 and the pistons 15 (see
Thus, in use, lubricant is pumped into the crankcase 19 via the passages in the plurality of bearings 24. The rotating crankshaft 18 agitates the lubricant and causes the lubricant to generally travel with (i.e. follow or be flung by) the crankshaft 18 generally in the direction of rotation of the crankshaft. The lubricant tends to stick to the rotating crankshaft 18 and/or travel and/or get flung into a revolving path alongside the outer surfaces 36 of the crankshaft.
Through research and experimentation, the present inventors have determined that lubricant in the above-described engine configuration tends to drain by gravity and according to the direction of rotation of the crankshaft 18, and collect, particularly, in the lowermost cylinder 16a. This can cause frictional losses in the system, which is disadvantageous. The present disclosure provides a unique solution to this problem.
As shown in
Referring to
In use, pressurized lubricant is pumped into the crankcase via the passages 26 in the plurality of bearings 24. The rotating crankshaft 18 agitates the lubricant and causes the lubricant to travel generally in the direction of rotation of the crankshaft 18. The lubricant tends to stick to the rotating crankshaft 18 and/or travel or get flung into a revolving path alongside the outer surfaces 36 of the crankshaft. According to the concepts presently disclosed, the outer surface 36 of the crankshaft 18 first rotates past the outer deflector 32, which deflects a portion of the lubricant that is traveling with or being flung alongside the outer surface 36 into the outer drain passage 30. The outer surface 36 of the crankshaft 18 continues to rotate past the lowermost cylinder 14a in the first bank of cylinders 14, and then past the central deflector 42, which deflects another portion of the lubricant that is travelling with or being flung alongside the outer surface 43 into the central drain passage 40. The outer surface 36 of the crankshaft continues to rotate past the lowermost cylinder 16a in the second bank of cylinders 16. This process repeats upon each rotation of the crankshaft 18 about the axis V. Thus, the lubricant carried or flung by the rotating crankshaft 18 during its rotation is efficiently deflected from the crankshaft 18 to the outer and central drain passages 30, 40, instead of migrating into the lowermost cylinder 16a in the second bank of cylinders 16. During experimentation, this was found to advantageously limit the frictional losses that otherwise occurred in the system
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 systems, methods and apparatuses described herein may be used alone or in combination with other systems, methods and apparatuses. Various equivalents, alternatives and modifications are possible within the scope of the appended claims.
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