Lubricating device for four-stroke engine

Details Lubricating device for four-stroke engine Lubricating device for four-stroke engine

1999-03-02

2001-01-09

Wolfe, Willis R. (Department: 3747)

Internal-combustion engines

Lubricators

Crankcase, pressure control

C123S1960CP, C184S006200

Reexamination Certificate

active

06170456

ABSTRACT:

FIELD OF THE INVENTION
The present invention involves a lubricating device for a four-stroke engine, and especially a system that can lubricate an engine running on any inclination.
BACKGROUND OF THE INVENTION
Compared with a two-stroke engine, a four-stroke engine has the advantages of cleaner exhaust and fuel saving. As such, more and more light duty, general industrial/agricultural machines adopt a four-stroke engine according to the Regulation on Environmental Protection. At the present, there are two types of lubricating devices used for a four-stroke engine, i.e., a wet (wet sump) and a dry type. A difference between them is whether or not a common space is used for the crankcase and the oil box.
FIG. 1
shows a design of American RYOBI Co. published in SAE TECHNICAL PAPER SERIES 961728, which is a common wet lubricating device for a four-stroke engine. In this device, a crankcase
11
and an oil box of the four-stroke engine have a common space, i.e., it is a so-called wet sump. This device can be used with certain light duty tools, such as a grass cutter, lopping shears, wood saw and so on. As will be appreciated, these tools are widely used and operated on various inclinations. However, the engine
10
is restricted to operating on no more than a slight inclination to avoid oil flowing out from the oil box. If the engine operates on a larger inclination, oil will flow out from the oil box to the gap between the piston
13
and the cylinder wall and will be pumped into the combustion chamber, resulting in engine failure or oil flowing into the cylinder head and then out from the vent/filter.
In order to allow the engine mentioned above to operate on any inclination, conventional designs also adopt a fully separated oil box, i.e. the oil box and the crankcase are completely separate, to form a so-called dry sump.
FIG. 2
shows a design of Japanese Patent of Application No. 7-327665, Application date of Dec. 15, 1995, in which a proper amount of oil is pumped to points to be lubricated in the engine, or oil
22
is splashed by a slinger
21
to create an oil fog which is pumped to the crankcase
23
and the cylinder head
25
for lubrication using suction generated by the piston
24
. Although the dry sump has a better structure than the wet sump, an additional oil trough, pressure regulating devices and additional drillings in the crankshaft are needed, resulting in a more complex structure and higher cost.
SUMMARY OF THE INVENTION
A major object of the present invention is to provide a semi-separate crankcase design, in which an oil trough is provided under the crankcase. The oil trough has an internal space just large enough for an oil dipper arm moving in it to create an oil mist for lubrication, so that only a little bit of oil may flow into the crankcase when the engine is inclined.
Another object of the present invention is to arrange a hole in the bottom of the oil trough. The hole forms a path from the oil box to the oil trough, and has a selected diameter that ensures a great amount of oil will not enter the crankcase when the engine is inclined.
A further object of the present object is to provide several plugs, each having an orifice, in the bottom of the crankcase. Therefore, even if the engine is running upside-down, oil will drop into the crankcase and be atomized by the rotating components for lubrication.
In order to describe the objects, characteristics and functions of the present invention, an example of an embodiment accompanied with figures is given as follows:


REFERENCES:
patent: 3687233 (1972-08-01), Greenwald
patent: 4270497 (1981-06-01), Valerio
patent: 5176116 (1993-01-01), Imagawa et al.
patent: 5738062 (1998-04-01), Everts
patent: 5860403 (1999-01-01), Hirano et al.
patent: 5960764 (1999-10-01), Araki
patent: 5975042 (1999-11-01), Aizawa et al.
patent: 9-170417 (1997-06-01), None
Conley, et al., “The New Ryobi 26.2 CC, OHV, 4-Stroke Engine For Hand Held Power Equipment Applications”, SAE Technical Paper Series 961728, Aug. 26-28, 1996.

Affiliated with

Also associated with

Rating

Lubricating device for four-stroke engine does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Lubricating device for four-stroke engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lubricating device for four-stroke engine will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2507647