Marine propulsion – Means for accomodating or moving engine fluids – Cooling for engine
Reexamination Certificate
2002-03-29
2004-02-24
Morano, S. Joseph (Department: 3617)
Marine propulsion
Means for accomodating or moving engine fluids
Cooling for engine
C123S572000
Reexamination Certificate
active
06695658
ABSTRACT:
PRIORITY INFORMATION
This application is based on and claims priority to Japanese Patent Application No. 2001-373759, filed Dec. 7, 2001, the entire contents of which are hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a lubricant reservoir. More specifically, the present invention relates to an improved breather arrangement for a lubricant reservoir.
2. Description of Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries one or more riders. A relatively small hull of the personal watercraft defines a rider's area above an engine compartment. An internal combustion engine powers a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on an underside of the hull. The jet propulsion unit, which includes an impeller, is placed within the tunnel. The impeller has an impeller shaft driven by the engine. The impeller shaft usually extends between the engine and the jet propulsion device through a bulkhead of the hull tunnel.
Four-stroke engines include lubrication systems arranged to supply lubrication oil to various portions of their engines, such as the crankshaft chamber and camshaft chamber. Desirably, a volume of lubrication oil is provided within a reservoir to be available for supply to the engine. The lubrication oil is permitted to cool upon being returned to the reservoir before again being supplied to the engine. As the oil pools in the reservoir, blow by gasses and air that have been entrained in the oil, aspirate out of the oil and collect in the reservoir. Vapor conduits can connect the lubricant reservoir with an induction system of the engine so as to draw out and dispose of the air and/or blow-by gasses.
SUMMARY OF THE PREFERRED EMBODIMENTS
One aspect of the present invention includes the realization that vapor recovery arrangements in the lubricant reservoirs of some watercraft can ingest liquid oil during normal operation. For example, with reference to
FIGS. 1 and 2
, the lubricant reservoir and vapor recovery arrangement
10
of a personal watercraft (not shown) is illustrated therein. The reservoir assembly and vapor recovery arrangement
10
include a lubricant tank
12
which includes a reservoir portion
14
and the vapor separator portion
16
.
The reservoir portion
14
includes an inlet
18
which receives liquid lubricant L from a pump (not shown). The reservoir portion
14
also includes an outlet
20
which guides lubricant L from the reservoir portion
14
to another pump (not shown).
The vapor separator portion
16
includes a baffle
22
mounted below an upper wall of the reservoir
12
. A breather chamber
24
is defined between the baffle
22
on the upper walls of the reservoir
12
. The baffle
22
includes a plurality of breather apertures
26
.
A conduit
27
extends from a side of the reservoir to the head of the associated engine. The conduit
27
thus allows oil overflowing within the reservoir
12
to be returned to the engine body. Additionally, blow-by gases contained within the engine body can flow into the reservoir
12
. A vapor recovery conduit
28
extends from an upper wall of the reservoir
12
to a second breather chamber
29
. The second breather chamber
29
defines a labyrinth path therein. The outlet of the second breather chamber
29
is connected to the induction system (not shown) of the watercraft.
In normal operation, the level of liquid lubricant L within the reservoir
12
means substantially level, as shown on FIG.
1
. As the engine (not shown) of the watercraft operates, liquid lubricant L travels up the inlet portion
18
and fills the reservoir portion
14
. Because the liquid lubricant L becomes entrained with air and/or blow-by gases as it moves through the engine, the air and/or blow-by gases along with some oil vapor V aspirate out of the liquid lubricant L. The vapors V travel through the apertures
26
into the breather chamber
24
. From the breather chamber
24
, the vapors travel through the vapor conduit
28
through the second breather chamber
29
. As the vapor V travels through the labyrinth path defined within the second breather chamber
29
, additional liquids, such as liquid lubricant L, precipitates out of the vapor V. The second breather chamber
29
includes a drain which allows the liquid lubricant L to return to the crankcase of the engine. The vapors that travel through the second breather chamber
29
return to the induction system of the engine for combustion within the engine.
When the watercraft is operated at elevated speed, and in particular at planing speeds, the watercraft continually jumps out of the water to varying degrees. Additionally, personal watercraft are often turned sharply during operation. It has been found that jumping and turning movements of such a watercraft tend to cause the liquid lubricant L, within the reservoir
14
to travel upwardly along the sides of the reservoir
14
toward the apertures
26
. As such, an excessive amount of liquid lubricant L, which can be in the form of large droplets, enters the first breather chamber
24
, and thus can enter the vapor recovery line
28
. Further, it has been found that enough liquid lubricant L can travel into the first breather chamber
24
so as to hinder the performance of vapor recovery and/or be drawn into the vapor recovery line
28
.
According to another aspect of the present invention, a watercraft includes a hull into an engine disposed within the hull. The engine includes a lubrication and vapor recovery arrangement including a lubricant reservoir in the breather assembly within the reservoir. The breather assembly includes at least one baffle defining a breather chamber within a lubricant reservoir. The baffle includes at least one aperture allowing vapor from the lubricant reservoir to flow into the breather chamber. Additionally, a wall extends downwardly from a lower surface of the breather assembly, around the periphery of the at least one aperture.
By providing the wall disposed around the periphery of the aperture in the baffle, less oil can enter the breather chamber. For example, when the watercraft is operated at a planing speed which it jumps out of the water and/or operated through highspeed turns, lubricant is urged upwardly along the sides of the lubricant reservoir towards the apertures. As the lubricant travels up the sides of the walls and hits the baffle, the lubricant is turned inwardly towards the apertures. The wall disposed around the periphery of the aperture helps divert the liquid lubricant away from the apertures. Thus, the baffle arrangement according to the present invention helps prevent oil from entering the breather chamber and thus impeding the operation of the breather assembly.
Further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiments which follow.
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Application entitled, Cooling System for S
Knobbe Martens Olson & Bear LLP
Morano S. Joseph
Vasudeva Ajay
Yamaha Marine Kabushiki Kaisha
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