Information
-
Patent Grant
-
6742482
-
Patent Number
6,742,482
-
Date Filed
Wednesday, August 22, 200123 years ago
-
Date Issued
Tuesday, June 1, 200420 years ago
-
Inventors
-
-
Examiners
- Argenbright; Tony M.
- Harris; Katrina B.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 123 71 R
- 123 65 R
- 123 536
- 123 597
- 123 662
- 123 533
- 123 557
- 123 552
- 123 556
-
International Classifications
-
Abstract
A two-cycle engine having improved performance characteristics includes a block and a cylinder head coupled to the block, the cylinder head defining a cylinder bore and a precombustion chamber. The head of piston located in the cylinder bore divides the bore into first and second variable volume intake chambers. An intake port allows fresh air to be drawn into the variable volume intake chamber and be compressed by the moving piston and delivered to the precombustion chamber. Fuel is added to the compressed air, which is heated, and then delivered to the variable volume combustion chamber. In one embodiment, the piston drives a crankshaft which is mounted both for rotation and for translation. Another embodiment of the invention is a lubricating system for a piston where movement of the piston up and down generates a pumping effect moving lubricant through the piston for lubricating piston rings.
Description
FIELD OF THE INVENTION
The present invention relates to two-cycle internal combustion engines, and more particularly to such an engine including a double-acting piston, a precombustion chamber and a translating and rotating crankshaft.
BACKGROUND OF THE INVENTION
In accordance with the laws of thermodynamics, it is desirable to provide an engine which maximizes pressure and temperature during combustion, as such results in the most efficient conversion of energy. In addition, in accordance with the laws of physics, the power to weight ratio of an engine increases as the speed of engine operation increases.
Unfortunately, a variety of secondary effects make difficult the achievement of an engine which achieves these objectives. As engine speed increases, so do the inertial forces and the stresses placed upon moving parts in the engine. At high speeds, the failure rate of these parts increases. Increasing the size of these parts to increase their strength has limited benefits, as such further increases the inertial forces and the total weight of the engine.
In some instances, current engine designs also do not permit ready solutions to these problems. For a number of reasons, traditional piston rods are much longer than the distance of the entire piston stroke. One advantage arising from a longer piston rods is such permits a longer piston stroke, and thus a higher compression ratio. The longer piston rod also provides greater clearance between the piston and crankshaft at bottom dead center. On the other hand, the longer piston rod is subject to high inertial forces.
A problem with raising engine temperatures and pressures is that the life of parts subjected to these high heat and pressures in the engine are reduced. In order to reduced the detrimental effects of the high heat, today's engines employ cooling systems. The cooling systems, however, serve to reduce the efficiency of the system.
Another problem with an engine operating at high speed is that the time for combustion is very short. To accommodate combustion time, combustion may be initiated before the piston is at top dead center. Combustion forces generated as the piston moves upwardly to top dead center act against the direction of the piston, contributing to a lower energy level of the engine. On the other hand, if combustion is not initiated until the piston is at top dead center, then total optimum combustion time is very short. As a result, the generated combustion force is limited, and so is the power output of the engine in relation to provided fuel.
Another disadvantage of a short combustion time is that certain less combustible alternative fuels are not usable in these engines. Simply, the combustion time is so short that slower combusting fuels do not sufficiently combust to generate efficient engine power. A problem with existing engines is that the optimal combustion time is so short, that it is detrimental to raise the speed of the engine because optimal combustion time is further shortened. This problem thus prevents achievement of an engine with otherwise higher efficiency by operation at higher speeds.
Two-cycle internal combustion engines have an advantage over four-cycle internal combustion engines in that an entire piston cycle is not lost without producing force. On the other hand, combustion effects are reduced due to incomplete scavenging: not all of the exhaust gasses are exhausted before combustion initiates, and insufficient incoming air is provided for complete combustion of the fuel.
One detrimental side effect of this incomplete combustion of fuel is the exhausting of unburned fuel and undesirable gasses. Due to the emission problems associated with two-cycle engines, in some instances U.S. laws prevent the operation of two-cycle engines.
An engine which is capable of exploiting the advantages of high pressures of combustion, high temperatures of combustion, and high engine speed is desired.
SUMMARY OF THE INVENTION
An improved internal combustion engine is disclosed. In one embodiment, the engine is a two-cycle engine with improved performance characteristics.
In one embodiment, the engine is an internal combustion engine including an engine block. Preferably, at least two cylinder heads are mounted to the block. A piston is movably mounted in a cylinder bore defined by each cylinder head. The cylinder bore is generally closed at its top and bottom, whereby the piston divides the bore into a first variable volume intake chamber and a second variable volume combustion chamber. The cylinder head farther defines a precombustion chamber, the precombustion chamber selectively in communication with the first variable volume intake chamber and the second variable volume combustion chamber.
At least one intake port is provided for permitting air to be drawn into the variable volume intake chamber. Air within the variable volume intake chamber is compressed when the piston in the cylinder bore moves downwardly.
At least one passage is provided for selectively permitting the compressed charge of air to flow into the precombustion chamber. Once in the precombustion chamber, the compressed air charge is heated, raising it to yet a higher pressure. A fuel delivery element is adapted to deliver fuel into the compressed air. A passage is provided permitting the fuel and air charge to flow from the precombustion chamber to the variable volume combustion chamber.
At least one valve is provided for selectively opening and closing the passage(s) between the variable volume intake chamber and the precombustion chamber, and the precombustion chamber and variable volume combustion chamber.
Ignition of the fuel and air mixture in the variable volume combustion chamber causes the piston to move downwardly in the cylinder bore. The piston is connected to a crankshaft which is mounted to the engine block.
In one embodiment, the block includes a first block gear and a second block gear. The crankshaft has a first end and a second end and at least one, and preferably two, piston mounting portions located between its ends. Each piston mounting portion is positioned along a first axis offset from a second axis through the first and second ends of the crankshaft. A first crankshaft gear is located at the first end of the crankshaft, the first crankshaft gear engaging the first block gear. A second crankshaft gear is located at the second end of the crankshaft, the second crankshaft gear engaging the second block gear. Movement of the piston causes the crankshaft to rotate about the second axis and the second axis to move in a generally circular pathway.
In one embodiment, the ends of the piston are supported by eccentric bearings. The bearings permit rotation and translation (i.e. movement of the rotational axis of the crankshaft) of the crankshaft.
In one embodiment of the invention, the block has four sides positioned between its ends. A cylinder head is coupled to each of the sides, and a piston is movably mounted in the cylinder bore defined by each head. The crankshaft includes a first piston mounting portion and a second piston mounting portion. A first pair of pistons mounted at opposing sides of the block are connected to one another about the first piston mounting portion. A second pair of pistons mounted at opposing sides of the block are connected to one another about the second piston mounting portion.
In one embodiment, the intake port includes an intake valve adapted to selectively open and close the intake port. A single valve is located in the precombustion chamber. The valve includes a first seal and a second seal. The first seal is adapted to selectively open and close the port or passage between the variable volume intake chamber and the precombustion chamber. The second seal is adapted to selectively open and close the port or passage between the precombustion chamber and the variable volume combustion chamber.
In one embodiment, the valve located in the precombustion chamber is driven by a rocker arm. The rocker arm is, in turn driven by an end of a follower. An opposing end of the follower is driven by a cam which is rotated by the crankshaft.
Another aspect of the invention is a lubricating and cooling system for a piston of an internal combustion engine, the piston having a head and a rod. A first end of the rod is coupled to the head and a second end of the rod is located opposite the first end thereof. A passage extends through the rod from the first end to the second end. An inlet leads from an exterior of the second end to the passage. At least one delivery passage is located in the head and extends from the passage in the head and returns to the passage in the rod. An outlet extends from the passage in rod.
At least one partition divides the passage through the rod into an inlet passage leading from the inlet to the delivery passage and an outlet passage leading from the delivery passage to the outlet. At least one lubrication directing element is located in the inlet passage and outlet passage, the at least one lubrication directing element generally inhibiting the flow of lubricant from the delivery passage to the inlet and from the outlet to the delivery passage.
Upward and downward movement of the piston during engine operation generates a pumping effect. Lubricant is drawn into the inlet and delivered to the head. The lubricant may be delivered through weeps to rings mounted on the exterior of the piston head. Excess lubricant is delivered back to the outlet.
Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.
DESCRIPTION OF THE DRAWINGS
FIG. 1
is a plan view of an exterior of an embodiment of an engine in accordance with the present invention;
FIG. 2
is a cross-sectional view of the engine illustrated in
FIG. 1
taken in the plane
2
—
2
;
FIG. 3
is a perspective view of an engine block in accordance with an embodiment of the invention;
FIG. 4
is a perspective view of a cylinder head in accordance with an embodiment of the invention;
FIG. 5
is a bottom plan view of the cylinder head illustrated in
FIG. 4
;
FIG. 6
is a cross-sectional view of the cylinder head illustrated in
FIG. 5
taken along line
6
—
6
therein;
FIG. 7
is a perspective view of an embodiment of a piston in accordance with the invention;
FIG. 8
is a partial crankshaft assembly of the present invention illustrated in an exploded view;
FIG. 9
is a side view of the crankshaft and a supporting assembly in accordance with the invention;
FIG. 10
illustrates the relationship between a crankshaft gear and supporting gear in accordance with an embodiment of the invention;
FIG. 11
is a perspective view of a valve rod in accordance with the invention;
FIG. 11A
is a perspective view of a valve rod with heat exchange element in accordance with another embodiment of the invention;
FIG. 12
is a top view of a bottom plate for the cylinder head illustrated in
FIG. 4
;
FIG. 13
is a cross-sectional view of the bottom plate illustrated in
FIG. 12
taken along line
13
—
13
therein;
FIG. 14
is a bottom view of a cylinder cap for the cylinder head illustrated in
FIG. 4
;
FIG. 15
is a cross-sectional view of the cylinder cap illustrated in
FIG. 14
taken along line
15
—
15
therein;
FIG. 16
is a cross-sectional view of a piston including a lubricating system in accordance with an embodiment of the invention;
FIG. 17
is a side view of a lubricating system partition and diverter assembly for positioning in a piston as illustrated in
FIG. 16
;
FIG. 18
is a perspective view of a diverter of the lubricating system illustrated in
FIG. 17
FIG. 19
is a front view of the assembly illustrated in
FIG. 17
;
FIG. 20
is a is a cross-sectional view of a piston including a lubricating system in accordance with another embodiment of the invention;
FIG. 21
is a plan view of a diverter of the lubricating system illustrated in
FIG. 20
;
FIGS. 22A-F
are a series of figures illustrating an engine cycle of the engine of the present invention;
FIGS. 23A-H
are a series of figures illustrating the movement of the crankshaft of the invention through a complete rotation thereof;
FIG. 24
is view of the piston illustrated in
FIG. 16
shown moving downward and illustrating the movement of lubrication thereby;
FIG. 25
is a view of the piston illustrated in
FIG. 16
shown moving upward and illustrating the movement of lubrication thereby;
FIG. 26
is a view of the piston illustrated in
FIG. 20
shown moving downward and illustrating the movement of lubrication thereby;
FIG. 27
is a view of the piston illustrated in
FIG. 21
shown moving upward and illustrating the movement of lubrication thereby;
FIG. 28
is an enlarged view of a portion of the piston illustrated in
FIG. 26
;
FIG. 29
is an enlarged view of a portion of the piston illustrated in
FIG. 27
;
FIG. 30
is a chart illustrating engine pressure versus crankshaft angle during operation of the engine in accordance with the invention; and
FIG. 31
illustrates an engine in accordance with an embodiment of the invention arranged in a “V” configuration.
DETAILED DESCRIPTION OF THE INVENTION
The invention is a two-cycle internal combustion engine. In the following description, numerous specific details are set forth in order to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention.
In general, the present invention comprises an improved internal combustion engine. In a preferred embodiment, the engine is a two-cycle internal combustion engine. In accordance with the invention, such an engine is provided having a two-way acting piston, a precombustion chamber, an improved lubricating system for moving parts, and an output shaft mounting and drive arrangement. It will be appreciated that the invention extends to one or more of the features of the engine used alone or in combination with one another, and to such features as used in other than a two-cycle internal combustion engine.
One embodiment of an internal combustion engine
20
in accordance with the invention will be described with reference to
FIGS. 1-3
. The engine
20
includes a block
22
. The block
22
is also illustrated in more detail in FIG.
3
. The block
22
preferably comprises a housing defining one or more hollow interior areas. The block
22
has a first end
24
and a second end
26
which support a crankshaft
28
, which crankshaft
28
is described in detail below. The crankshaft
28
extends through the generally hollow interior of the block
22
.
The block
22
generally has four sides
30
a, b, c, d
between its ends
24
,
26
. Preferably, opposing pairs of sides are positioned in parallel, spaced apart planes, while adjacent sides adjoin at right angles. In this arrangement, the sides
30
a, b, c, d
define a generally cube-shaped block.
Each side
30
a, b, c, d
defines a mounting area for a head
32
. Referring to
FIG. 3
, in one embodiment, each side
30
a, b, c, d
includes a main piston opening
34
and a valve opening
36
. Preferably, these openings
34
,
36
are in communication with the hollow interior area of the block
22
housing the crankshaft
28
.
Referring to
FIGS. 1 and 2
, a head
32
is connected to each side
30
a, b, c, d
of the block
22
. Each head
32
may be connected to the block
22
in a variety of manners, such as with nuts and bolts. In one embodiment, the heads
32
may be formed with the block
22
in whole or in part.
FIG. 4
illustrates the head
32
in perspective view. In a preferred embodiment, and referring to
FIG. 2
, each head
32
includes a body
38
and a cap
40
. A bottom plate
42
is located at a first end of the body
38
of the head
32
. The cap
40
is located at the opposing second end of the body
38
of the head
32
. Preferably, when the head
32
is mounted to the block
22
, the bottom plate
42
is positioned against the exterior of the side of the block
22
. In one embodiment, the bottom plate
42
is formed integrally with the remainder of the body
38
of the head
32
. Alternatively, the bottom plate
42
may be an independent element which is connected to the body
38
of the head
32
.
As illustrated in
FIG. 12
, the bottom plate
42
preferably includes a piston opening
44
and a valve opening
46
. The size and orientation of these openings
44
,
46
is preferably similar to that of the openings
34
,
36
in the side of the block
22
, whereby the openings in the block
22
and head
32
align when the head
32
is mounted to the block
22
.
Referring to
FIGS. 4-6
, the body
38
of the head
32
defines a cylinder bore
48
. The cylinder bore
48
is preferably an elongate cylindrical passage. The bore
48
may be of a variety of diameters. Referring to
FIG. 2
, when mounted, the piston opening
44
in the bottom plate
42
aligns with the cylinder bore
48
in the body
38
. At the top end, the head cap
40
encloses the top of the cylinder bore
48
. In a preferred embodiment, the head cap
40
is removable from the body
38
of the head
32
, thus providing a means for access into the cylinder bore
48
.
As illustrated in
FIG. 6
, the body
38
of the head
32
also defines a first or precombustion chamber
50
. The first combustion chamber
50
is an elongate cylindrical bore extending from end-to-end through the body
38
. In one embodiment, the diameter of the bore defining the first combustion chamber
50
is generally smaller than the diameter of the cylinder bore
48
. Referring to
FIG. 2
, at the first end of the body
38
, the valve opening
46
in the bottom plate
42
aligns with the first combustion chamber
50
. At the top or second end of the body
38
, the head cap
40
(see also
FIG. 15
) extends over but does not fully enclose the first combustion chamber
50
. Instead, a small bore
52
is provided in the cap
40
in alignment with the bore defining the first combustion chamber for passage there through of a rod of a valve, as described in more detail below.
A piston
54
is mounted in each cylinder bore
48
between the bottom plate
42
and the head cap
40
. As best illustrated in
FIG. 7
, the piston
54
includes a head
56
and a rod
58
extending from the head
56
. Preferably, the head
56
is a cylindrical body having a diameter slightly less than the diameter of the cylinder bore
48
, and a height less than the length of the cylinder bore
48
. The rod
58
is preferably a cylindrical member extending from the piston head
56
through the piston opening
44
in the bottom plate
42
to the crankshaft
28
.
In one embodiment, one or more rings
60
are mounted on the exterior of the piston head
56
. The rings
60
may include compression and oil rings, as are known in the art for sealing the piston head in the chamber, preventing gasses and fluids from moving from one side of the piston head to the other in the cylinder bore
48
.
Referring to
FIG. 2
, a seal
62
is preferably provided for sealing the space between the piston rod
58
and the bottom plate
42
at the piston opening
44
. The seal
62
may comprise a plurality of ring elements.
Still referring to
FIG. 2
, so mounted in its respective head
32
, each piston
54
defines two variable volume chambers. A first variable volume chamber is located between the piston head
56
and the head cap
40
. A second variable volume chamber is located between the piston head
56
and the bottom plate
42
. As will be appreciated, as the piston
54
moves within the cylinder bore
48
, the volumes of these chambers increase and decrease in proportion to one another. As will be appreciated later, the first chamber may be referred to as a variable volume combustion chamber, while the second as a variable volume intake chamber, owing to their functions.
As described in more detail below, combustion forces move the pistons
54
up and down within the cylinder bores
48
. The movement of the pistons
54
is utilized to rotate the crankshaft
28
.
The crankshaft
28
will be described with reference to
FIGS. 2
,
8
and
9
. The crankshaft
28
includes a body which is similar in many respects to crankshafts which are well known in the art. The crankshaft
28
has a first end
64
and a second end
66
. The first and second ends
66
of the crankshaft
28
are rotatably supported by the block
22
.
A first gear
68
is located at the first end
64
of the crankshaft
28
. In one embodiment, the first gear
68
is integrally formed with the remainder of the crankshaft
28
, and comprises a plurality of teeth formed about the exterior of the first end
64
of the crankshaft. The first gear
68
is configured to engage a first block gear
72
. Preferably, the first block gear
72
comprises a gear member having teeth facing inwardly in a closed circular configuration. In one embodiment, the first block gear
72
may comprise a mating teeth formed in the block
22
at the crankshaft opening at the first end
24
of the block
22
. In another embodiment, a gear body is mounted to the exterior of the block
22
, the gear body having a passage there through defined by a circular inner wall or perimeter having the teeth formed thereon.
Preferably, the circumference of the first gear
68
of the crankshaft
28
is smaller than (as described below, preferably one-half the size of) the circumference of the first block gear
72
. Rotation of the crankshaft
28
causes the first gear
68
to move in a circular motion about the first block gear
72
.
In one embodiment, a second gear
70
is located at the second end
66
of the crankshaft
28
. In one embodiment, the second gear
70
is integrally formed with the remainder of the crankshaft
28
, and comprises a plurality of teeth formed about the exterior of the second end
66
of the crankshaft. The second gear
70
is configured to engage a second block gear
74
. Preferably, the second block gear
74
comprises a gear member having teeth facing inwardly in a closed circular configuration. In one embodiment, the second block gear
74
may comprise mating teeth formed in the block
22
at the crankshaft opening at the second end
26
of the block
22
. In another embodiment, a gear body is mounted to the exterior of the block
22
, the gear body having a passage there through defined by a circular inner wall or perimeter having the teeth formed thereon.
Preferably, the circumference of the second gear
70
of the crankshaft
28
is smaller than (as described below, preferably one-half the size of) the circumference of the second block gear
74
. Rotation of the crankshaft
28
causes the second gear
70
to move in a circular motion about the second block gear
74
.
In a preferred embodiment, as best illustrated in
FIG. 10
, the diameter of the gear of the crankshaft
28
is D, while the diameter of the gear of the block
22
is
2
D. In this arrangement, the diameter of the gear of the crankshaft is one-half of the size of the gear of the block.
The crankshaft
28
is preferably rotatably supported by the block
22
, keeping the first and second crankshaft gears
68
,
70
in contact with the first and second block gears
72
,
74
. In one embodiment, the crankshaft
28
includes a first journal portion
76
adjacent the first gear
68
and a second journal portion
78
adjacent the second gear
70
. Each journal portion
76
,
78
comprises a smooth cylindrical portion of the crankshaft body.
A first eccentric bearing
80
engages the first journal portion
76
of the crankshaft
28
. The first eccentric bearing
80
is supported by the block
22
. In an embodiment where the first block gear
72
is mounted external to the first end
24
of the block
22
, the eccentric bearing
80
may be supported by the wall of the block
22
forming the first end of the block.
Likewise, a second eccentric bearing
82
engages the second journal portion
78
of the crankshaft
28
. The second eccentric bearing
82
is supported by the block
22
. In an embodiment where the second block gear
74
is mounted external to the second end
26
of the block
22
, the eccentric bearing
82
may be supported by the wall of the block
22
forming the second end of the block.
The crankshaft
28
includes a first piston set mount or mounting portion
84
and a second piston set mounting portion
86
. Each mount or mounting portion
84
,
86
preferably comprises a generally smooth rod or cylinder-shaped portion of the crankshaft
28
.
In a preferred embodiment, the mounts
84
,
86
are offset and do not have their centers along the same axis. In one embodiment, as illustrated in
FIG. 9
, the crankshaft
28
includes a crankshaft centerline CL which extends through the first and second ends
64
,
66
of the crankshaft
28
. The axes through the center of each of the mounts
84
,
86
are offset from the crankshaft centerline CL and from one another. In one embodiment, the mounts
84
,
86
are aligned with a centerline of the engine CL at one or more times (when rotated into a particular position).
In one embodiment a first pair of opposing pistons
54
located nearest the first end
24
of the block
22
are connected to the first mount
84
. A second pair of opposing pistons
54
located nearest the second end
26
of the block
22
are connected to the second mount
86
. In one embodiment, each piston
54
is connected via a half-bearing
88
at the end of the piston rod
58
opposite the piston head
56
. Referring to
FIGS. 2 and 7
, the half-bearing
88
is preferably designed to be connected to an opposing half-bearing associated with another piston. In this manner, opposing pistons
54
are mounted to one another about one of the piston mounting portions of the crankshaft
28
. A pin
90
or other mounting may be used to connect the bearing
88
to the rod
58
.
Referring again to
FIG. 2
, in a preferred embodiment of the invention, a valve
92
is associated with each first combustion chamber
50
. In one embodiment, as illustrated in
FIG. 11
, the valve
92
is an elongate rod having a first end and a second end. A first seal
94
is located at the first end of the valve
92
. The first seal
94
is preferably a circular disc located at the end of the rod forming the majority of the valve
92
. The first seal
94
has an outer diameter slightly less than the inner diameter of the chamber
50
.
A second seal
96
is located near the second end of the valve. The second seal
96
preferably also comprises a generally circular disk having a diameter slightly less than the inner diameter of the chamber
50
.
A stem
98
is located at the second end of the valve
92
. As illustrated, when positioned in the first or precombustion chamber
50
, the first seal
94
is located near the bottom plate
42
of the cylinder head
32
. The second seal
96
is located near the head cap
40
. The stem
98
extends through the bore
52
in the cap
40
to a point external to the cylinder head.
FIG. 11A
illustrates another embodiment of a valve
92
a
. In this embodiment, the valve
92
a
includes heat exchange element or member
93
. In the embodiment illustrated, the heat exchange element
93
comprises a helical member position along a stem of the valve
92
a
. In general, the heat exchange element
93
is adapted to increase the surface area of the valve
92
a
, permitting a greater heat transfer rate. In on embodiment, the element
93
may be integrally formed with the stem or body portion of the valve
92
a
. Of course, other varieties of heat exchange elements may be utilized.
Referring to
FIGS. 2 and 8
, in a preferred embodiment, means are provided for moving the valve
92
. In a preferred embodiment, the means includes a cam
100
. In one embodiment, the cam
100
is mounted to the eccentric bearing
82
located at the second end of the crankshaft
28
. The cam
100
has an outer surface which varies in distance from a rotational axis.
A follower
102
extends from the cam
100
upwardly from the cam
100
generally parallel to the cylinder head
32
. A first end of the follower
102
engages the cam
100
, such that rotation of the cam moves the follower up and down in accordance with the profile of the cam. Preferably, the profile of the cam
100
is appropriately configured to accomplish movement of the follower as described in detail below in conjunction with
FIGS. 22A-F
.
As illustrated in
FIG. 2
, a rocker
104
is located at the second end of the follower
102
. The rocker
104
has a first arm
106
and a second arm
108
extending from either side of a pivot. The first arm
106
is arranged to engage a second end of the follower
102
. The second arm
108
is arranged to engage the stem
98
of the valve
92
. In one embodiment, a biasing means is provided for maintaining the follower
102
in engagement with the cam
100
. The biasing means may comprise a spring associated with the rocker
104
causing the rocker to apply downward pressure upon the follower
104
. As described in more detail below, upward movement of the follower
102
pushes the first arm
106
of the rocker upwardly, and thus the second arm
108
downwardly. Downward movement of the second arm
108
causes the valve
92
to be moved downwardly.
In one embodiment, the rocker
104
is mounted to the cylinder head
32
. The rocker
104
and follower
102
may be located under a protective cover. Appropriate lubrication may be provided to these members. Of course, a follower
102
and rocker
104
are provided for each cylinder of the engine
20
.
Biasing means may be provided for biasing the valve
92
upwardly, maintaining it in contact with the second arm
108
of the rocker
104
. This biasing means may comprise a spring (not shown).
Passages are provided allowing air, fuel and mixtures of burned and unburned air and fuel to move in and out of the precombustion chamber
50
and cylinder bore
48
. In one embodiment, as illustrated in
FIG. 2
, an intake passage or port
110
is provided to the cylinder bore
48
. Preferably, the intake passage
110
is provided in communication with a portion of the cylinder bore
48
below the piston head
56
. As illustrated, the intake port
110
extends from an exterior of the head
32
through the bottom plate
42
to the bore
48
. As described in more detail below, the intake port
110
permits fresh air to be drawn into the cylinder bore
48
.
FIGS. 12 and 13
illustrate a preferred configuration of the bottom plate
42
. As illustrated, the intake port
110
generally comprises a plurality of individual passages extending horizontally through the plate
42
to vertically extending inlet
109
.
In one embodiment, a valve
111
is provided for selectively opening and closing the intake port
110
. In a preferred embodiment, the valve
111
is a poppet type valve which is biased into a closed position. As described in more detail below, a condition of reduced pressure within the cylinder bore
48
causes the valve
111
to be moved upwardly as a result of the higher air pressure on the exterior side of the valve. As illustrated, the valve
111
is preferably “C” shaped and includes a head and a seating section, the seating section extending downwardly into the intake port
110
for use in guiding/aligning the valve
111
.
A compression port
112
is provided between the cylinder bore
48
and the precombustion chamber
50
. In a preferred embodiment, the compression port
112
extends from a portion of the cylinder bore
48
below the piston head
56
to the precombustion chamber
50
. As illustrated, the compression port
112
is also provided in the bottom plate
42
of the cylinder head
32
. A preferred arrangement of the bottom plate
42
including the compression port
112
is illustrated in
FIGS. 12 and 13
.
As illustrated in
FIG. 2
, a bi-directional combustion and exhaust port
114
is provided as well. As illustrated, the bi-directional port
114
is provided in communication with a portion of the cylinder bore
48
above the piston head
56
. At one or more times, the bi-directional port
114
is in communication with the precombustion chamber
50
. As illustrated, the bi-directional port
114
is provided in the cylinder cap
40
. A preferred configuration of the cylinder cap
40
is illustrated in
FIGS. 14 and 15
.
As described in more detail below, the valve
92
is designed to cooperate with the compression port
112
and bi-directional port
114
. The locations of these ports and the configuration of the valve
92
are designed to provide a specific effect. In particular, movement of the first seal
94
of the valve
92
is adapted to open and close the compression port
112
at its entrance to the precombustion chamber
50
. The movement of the second seal
96
of the valve
92
is adapted to open and close a pathway from the precombustion chamber
50
to the bi-directional port
114
leading to the cylinder bore
48
.
The engine
20
includes a fuel delivery system. Such systems are well known and thus are not described herein. In general, the engine
20
may use any of a variety of known fuel delivery systems. Preferably, the fuel delivery system includes a fuel supply, a pump or other means for moving the fuel from the supply and pressurizing the fuel, and a fuel injector
116
for injecting fuel under pressure. In a preferred embodiment, the fuel injector
116
is arranged to deliver fuel into the precombustion chamber
50
.
Appropriate controls are preferably provided for controlling the injector
116
associated with each cylinder
32
. These controls are arranged to control the timing and duration of fuel delivery.
In a preferred embodiment, an ignition mechanism is provided for igniting a fuel and air mixture in the cylinder bore
48
above the piston head
56
. In one embodiment, the ignition mechanism includes a spark plug (not shown). The spark plug preferably has a tip positioned in the cylinder bore
48
, such as by threading the plug into a passage through the cylinder body
38
or the cylinder cap
40
. A control and power delivery system may be provided for delivering electrical energy to the spark plug at the appropriate time for the start of ignition.
As illustrated in
FIG. 8
, in one embodiment of the invention, an output shaft
120
is provided. The output shaft
120
is preferably coupled to the crankshaft
28
for transferring rotational energy of the crankshaft
28
to another element, such as a transmission. As illustrated, the output shaft
120
preferably comprises a shaft having a universal joint. In one embodiment, the output shaft
120
is keyed at one end for insertion into a correspondingly shaped aperture in the first end of the crankshaft
28
at the first end
24
of the engine
20
. The opposing end of the output shaft
120
is formed as a female coupling to accept a driven member.
Another aspect of the present invention is a lubricating system for one or more moving parts of the engine
20
. In one embodiment, the invention is a lubricating system for each piston
54
. In accordance with one embodiment of the invention, the rod
58
and at least a portion of each piston head
56
is hollow or has one or more passages there through. As illustrated in
FIG. 16
, a main passage
122
is provided through the rod
58
. An inlet
124
is provided from the exterior of the rod
58
to the main passage
122
. At least one delivery passage
126
extends from the main passage
122
in the rod
58
through the piston head
56
to an outer area thereof for delivering lubricant to the rings
60
. The delivery passage
126
preferably extends back to the main passage
122
. An outlet
128
is provided from the main passage
122
to the exterior of the rod
58
.
In one embodiment, the inlet
124
is formed near a trough defined by an outwardly extending member, such as a portion of the half-bearing or mount
88
.
In accordance with the invention, there is provided a means for moving lubricant through the main passage
122
to the delivery passage
126
to the rings
60
. In a preferred embodiment, the means comprises a linear pump cell
130
. The linear pump cell
130
is located in the main passage
122
of the rod
58
. The linear pump cell
130
comprises a partition
132
and a plurality of flow directing elements
134
. Preferably, the partition
132
divides the main passage
122
into two portions, a first passage
125
a
leading from the inlet
124
to the delivery passage
126
, and a second passage
125
b
leading from the delivery passage
126
to the outlet
128
. As best illustrated in
FIGS. 16-19
, the flow directing elements
134
comprise generally flat, elliptically shaped members. The elements
134
are mounted to the partition
132
at an angle with respect to horizontal, and preferably such that they angle upwardly in the portion of the main passage
122
leading from the inlet
124
and downwardly in the portion of the main passage
122
leading to the outlet
128
.
As illustrated in
FIG. 18
, each flow directing element
134
includes a cut-out
136
at each end. When the flow directing elements
134
are located in the main passage
122
, they substantially obstruct the main passage
122
except for the cut-out areas
136
, which areas define a passage through which lubricant may flow. Details of the operation of the lubricating system are provided below in conjunction with
FIGS. 24 and 25
.
Another embodiment of a lubricating system for a piston is illustrated in
FIGS. 20 and 21
. Similar to the lubricating system described above, at least a portion of each piston head
56
is hollow or has one or more passages there through. The piston
54
again includes a main passage
142
through the rod
58
. An inlet
144
is provided from the exterior of the rod
58
to the main passage
142
. At least one delivery passage
146
extends from the main passage
142
in the rod
58
through the piston head
56
to an outer area thereof for delivering lubricant to the rings
60
. The delivery passage
146
preferably extends back to the main passage
142
. An outlet
148
is provided from the main passage
142
to the exterior of the rod
58
.
In accordance with the invention, there is provided a means for moving lubricant through the main passage
142
to the delivery passage
146
to the rings
60
. In a preferred embodiment, the means comprises a linear pump cell
150
. The linear pump cell
150
is located in the main passage
142
of the rod
58
. The linear pump cell
150
comprises a support
152
, a divider
154
, and at least one flow directing element
156
.
Referring to
FIG. 21
, in a preferred embodiment the support
152
comprises a rod or similar member. The dimension of the support
152
permits it to fit within the main passage
142
but leave substantial space between it and the rod
58
in which the passage
142
is formed.
The divider
154
comprises a helical wall which extends along the length of the support
152
and which extends outwardly therefrom. The divider
154
preferably extends outwardly from the support
152
a distance which causes it to abut the inside of the main passage
142
when the pump cell
150
is located therein. In this configuration, the divider
154
cooperates with the rod
58
and the support
152
to form a generally helical main passage
142
.
The at least one flow directing element
156
comprises a stepped or laddered flow director. In a preferred embodiment, the flow directing element
156
extends in helical fashion around the rod
58
. The element
156
is located in the helical passage
142
defined by the rod
58
and divide
154
, further dividing the passage into a pair of passages
159
a, b.
The element
156
includes alternating upwardly extending walls
157
a
and downwardly extending walls
157
b
. The upwardly extending walls
157
a
are slanted and extending upwardly a greater distance than the downwardly extending walls
157
b
. Preferably, the downwardly extending walls
157
b
are nearly vertical.
A trough
157
c
is formed at the intersection of each upwardly extending wall
157
a
and downwardly extending wall
157
b
. As described below, these troughs
157
c
hold lubricant in transport along the elements
156
.
One of the passages
159
a
has its inlet in communication with the inlet
144
to the interior of the rod
58
. This passage leads to the delivery passage
146
.
The other of the two passages
159
b
leads from the delivery passage
146
to the outlet
148
. In one embodiment, walls
160
are provided for dividing or sealing the passages
159
a
,
159
b
from one another.
Details of the operation of this embodiment lubricating system are provided below in conjunction with
FIGS. 26-29
.
Operation of the engine
20
described is as follows. In the description of the combustion cycle of the engine
20
, with reference to
FIGS. 22A-F
(shown in general schematic form and not in exacting detail to the preferred embodiment of the invention described above and illustrated in FIGS.
1
-
21
), reference is made to only a single cylinder of the engine
20
. Referring to
FIG. 22A
, the piston
54
of the cylinder is illustrated just after it has reached its top dead center position and has begun to move downwardly. At this time, the area below the piston head
56
is filled with a fresh air charge. As noted, the cylinder head
32
and piston
54
cooperate to define a variable volume chamber below the piston head
56
. At the point in time illustrated, this chamber is sealed, as the pressure of the air within the chamber has caused the valve
111
associated in the intake port
110
to close. In addition, the first seal
94
of the valve
92
is in a position in which it has closed the compression port
112
, preventing the escape of air to the pre combustion chamber
50
. As the piston
54
moves downwardly, the air within this variable volume chamber is compressed, raising its pressure.
In a preferred embodiment, combustion of the air and fuel begins in the precombustion chamber (such as described below, via initiation with heat of compression or a spark plug). Thus at the time illustrated, the pressurized air and fuel mixture formed within the precombustion chamber
50
which has already begun to ignite or burn flows into the variable volume combustion chamber located above the downwardly moving piston head
56
. The fuel and air charge flows through the bi-directional port
114
as at this time the second seal
96
of the valve
92
is positioned above the port
114
, and at the same time closes the exhaust pathway through the cylinder head cap
40
. The burning of the charge causes the rapidly burning and expanding fuel and air mixture to force the piston
54
downwardly. The downward force of the piston
54
is used to drive the crankshaft
28
, as is known in the art of reciprocating piston type internal combustion engines.
FIG. 22B
illustrates the piston
54
as it is forced downwardly in a power stroke towards its bottom dead center position. At this time, the fresh air charge under the piston head
56
has been significantly compressed to a high pressure. The fuel and air charge above the piston head
56
has substantially completed combusting. During the movement of the piston
54
from near its top dead center to near its bottom dead center it will be seen that the valve
92
remains in a relatively constant position. It is noted that as the piston
54
moves downwardly, the increase in volume draws the pressurized fuel and air charge from within the precombustion chamber
50
into the combustion chamber.
FIG. 22C
illustrates the piston
54
at nearly its bottom dead center position. At this time, rotation of the cam
100
to a new profile area has resulted in movement of the valve
92
. As illustrated, the valve
92
has been permitted to move downwardly with respect to the cylinder head
32
. The first seal
96
is in a position in which it no longer obstructs the compression port
112
. At the same time, the second seal
98
has moved into a position in which is obstructs a top portion of the pre combustion chamber
50
, sealing it from the bi-directional port
114
.
When the first seal
94
moves into a position in which is no longer obstructs the compression port
112
, the compressed fresh air charge flows into the lower pressure precombustion chamber
50
. Thus, the precombustion chamber
50
is filled with a charge of fresh air at high pressure.
At the same time, the combusted fuel and air charge above the piston head
56
is permitted to begin flowing from the combustion chamber through the bi-directional port
114
and the bore
52
in the head cap
40
. Preferably, the exhaust flows into an exhaust pathway leading to a catalytic converter and muffler then to a point of discharge from the engine
20
.
FIG. 22D
illustrates the piston
56
after it has reach its bottom dead center position and has begun to move upwardly. At this time, the cam
100
has rotated to a position in which it has forced the valve
92
upwardly. The valve
92
has been moved upwardly a sufficient distance that the first seal
94
again seals or closes the compression port
112
. However, the second seal
94
still seals the top of the precombustion chamber
50
, preventing escape of the fresh air charge in the precombustion chamber. Importantly, at this time, the already mechanically pressurized fresh air charge within the precombustion chamber is further pressurized. Heat of combustion from within the precombustion chamber
50
from the previous cycle heats the newly introduced air in the precombustion chamber
50
. In addition, some heat from cylinder bore passes through the body of the cylinder head
32
.
As the piston
54
moves upwardly, a condition of reduced pressure is created under the piston head
56
. Higher pressure fresh air on the opposing side of the valve
111
moves the valve
111
into its open position, permitting fresh air to flow through the inlet port
110
into the chamber below the piston
54
.
Movement of the piston
54
upwardly forces the combusted air and fuel exhaust from the combustion chamber. The exhaust continues to flow out through the bi-directional port
114
.
FIG. 22E
illustrates the piston
54
as it moves towards its top dead center position. Fresh air continues to be drawn into the area below the piston
54
. The exhaust continues to be forced out of the combustion chamber through the bi-directional port
114
.
FIG. 22F
illustrates the piston
54
at nearly its top dead center position. As illustrated, at this time, the valve
92
is in generally the same position as previously illustrated. The precombustion chamber
50
is sealed. Fuel is injected into the pressurized air charged in the precombustion chamber
50
. The fuel is injected with the fuel injector
116
or similar member. Preferably, ignition of the air and fuel within the precombustion chamber
50
is then initiated, such as by a spark plug (not shown) or other ignition device.
The process then repeats at
FIG. 10A
, with the ignited fuel and air charge being released from the precombustion chamber into the main combustion chamber above the piston
54
.
Each piston
54
preferably moves through this same cycle. In a preferred embodiment where more than one cylinder and corresponding piston are provided, one or more of the pistons are preferably arranged to be at a different point in the combustion/exhaust cycle at the same time. In this manner, as one piston is in a non-power producing portion of its cycle, another piston is in the power stroke portion, thus rotating the crankshaft and aiding in the movement of the other piston through the portion of its cycle which is non-power producing.
Movement of the crankshaft
28
during operation of the engine
20
will be described with reference to
FIGS. 23A-H
. The crankshaft
28
is shown as viewed towards its first end
64
. In
FIGS. 23A-H
, the first gear
68
at the first end
64
of the crankshaft
28
is shown as engaged with the first block gear
72
. The first and second mounting portions
84
,
86
of the crankshaft
28
are also illustrated.
FIG. 23A
illustrates the crankshaft
28
at an arbitrary position referred to as the 0 degree position. In this position, the first and second mounting portions
84
,
86
and the first end of the crankshaft
28
are all aligned vertically. As a result of a power stroke and exhaust stroke of the pistons associated with the first and second mounts
84
,
86
, the first mounting portion
84
is driven downwardly, while the second mounting portion is driven outwardly. As a result, the crankshaft
28
, which is rotating counter-clockwise, moves along the first block gear
72
in a clockwise direction. The crankshaft
28
is then in the position illustrated in FIG.
23
B.
Further operation of the engine
20
causes the first mounting portion
84
to be driven downwardly until the first and second mounting portions
84
,
86
and first end
64
of the crankshaft
28
are all aligned along a horizontal axis, as illustrated in FIG.
23
C.
The first mounting portion
84
is driven further downward while the second mounting portion
86
begins its return, moving in the opposite direction. The crankshaft
28
continues to rotate, with the first end
64
moving further clockwise around the first block gear
72
to the position illustrated in FIG.
23
D.
Further movement of the crankshaft
28
occurs in like manner as illustrated in
FIGS. 23E through 23H
until the crankshaft
28
returns to its original starting position.
It will now be appreciated that in a preferred embodiment, the first pair of pistons
54
move cooperatively to move the first mounting portion
84
of the crankshaft
28
. When one piston of that pair is moving downwardly in its power stroke, it is forcing the other piston upwardly in an exhaust stroke. Likewise, the other pair of pistons are associated with the second mounting member
86
. Moreover, the first and second mounting portions
84
,
86
are offset so that the crankshaft
28
is translated, i.e. moved laterally or other than rotationally.
Because the crankshaft
28
translates, the attachment point of each piston
54
also moves, but a greater distance than if the crankshaft only rotated. In this configuration, the throw or maximum distance traveled by each piston
54
is great, even though the length of the piston rod is quite short.
Operation of the lubricating system for the pistons in accordance with the embodiment illustrated in
FIGS. 16-19
will now be described in detail with reference primarily to
FIGS. 24 and 25
. In general, the operation of the lubricating system is in the nature of a linear pump. As the piston
54
moves downwardly, oil flows from the inlet
124
upwardly through the first passage
125
a
to the delivery passage
126
. The upward flow occurs as lubricant passes through the cut-outs
136
in the elements
134
. Notably, upward movement of oil from the outlet
128
through the second passage
125
b
is inhibited by the partition elements
132
. The upward flow of oil forces oil through the various lubricating passages in the piston head and through lubricating weeps for lubricating the rings.
Referring to
FIG. 25
, as the piston
54
moves upwardly, oil is swept off of the piston rod towards the inlet
124
. In addition, the inertial forces draw excess lubricant downwardly from the delivery passage
126
through the second passage
125
b
to the outlet
128
. At the same time, downward movement of oil from the delivery passage
126
through the first passage
125
a
is inhibited by the partitions
132
.
In this cycle, oil is provided to the inlet
124
, is forced upwardly through the first passage
125
a
to the delivery passage
126
and weeps. Excess lubricant is then drawn back to the outlet
128
.
Operation of the lubricating system for the pistons in accordance with the embodiments illustrated in
FIGS. 20-21
will now be described in detail with reference to
FIGS. 26-29
.
Operation of this embodiment system is similar to that described above. In this embodiment system, upward movement of the piston
56
causes lubricant to be directed into the inlet
124
, as illustrated in FIG.
27
. At this time excess lubricant is directed from the delivery passage
146
to the outlet
148
through the second passage
159
b
. As illustrated in greater detail in
FIG. 28
, downward flow of the lubricant from the delivery passage
146
to the inlet
144
is prohibited in that the lubricant is trapped by the troughs
157
c
in the first passage
159
a.
Referring to
FIG. 26
, upon downward movement of the piston
56
, lubricant delivered to the trough area and inlet
144
is directed upwardly to the delivery passage
146
through the first passage
159
. As illustrated in greater detail in
FIG. 29
, lubricant is prohibited from moving from the outlet
148
back to the delivery passage
146
through the second passage
159
b
by the troughs
157
c
defined by the flow directing element
156
.
Of course, the engine
20
need not be configured exactly as illustrated, and many alternate configurations are contemplated as within the scope of the invention. Further, one or more features of the invention may be used alone or in combination with other elements not described in detail herein.
In one embodiment, the engine
20
may have more than four cylinders or less than four cylinders. For example, the engine
20
may have two cylinders including two opposing pistons. The crankshaft and block of the engine
20
may be elongate and for accommodating six cylinders and six pistons.
The lubricating system described above may be used in a variety of other environments or applications. For example, the lubricating system may be applied to a piston of a four-cycle internal combustion engine of the type now known.
The various components of the engine
20
may be constructed of a wide variety of materials. These materials may include, but are not limited to metal, ceramic and plastic.
The components of the engine
20
may vary from that described above. For example, the cylinder head
32
may be formed with an integral head cap or bottom plate. One or more portions of the cylinder head
32
may also be integrally formed with the block
22
. In one arrangement, the bottom plate may actually be formed inside of the engine block, this portion of the engine block thus forming the lower portion of the cylinder.
The valves used to control the flow of air, air and fuel, and exhaust through the engine
20
may vary from that described. For example, electronically controlled valves, such as butterfly or rotating port valves may be utilized. Other means that the cam and follower arrangement may be utilized to move the valve
92
. For example, the valve
92
may be moved with a motor.
One advantage to the configuration of the first and second seals
94
,
96
being of substantially the same size or surface area is that the pressure of the air within the precombustion chamber
50
acting upon the seals
94
,
96
is generally the same. Thus, the pressure of the air does not tend to move the valve
92
in one direction or the other. It will be appreciated that, if desired, one seal or the other may be configured to be larger (and fit within a correspondingly larger portion of the cylinder head
32
defining the chamber
50
) to bias the valve
92
into a particular position. For example, the second seal
96
may be slightly larger than the first seal
94
, so that when acted upon by an excessively high pressure, the valve
92
is moved upwardly to exhaust the air from the precombustion chamber
50
, acting similar to a relief valve.
The various shapes and sizes of the components of the engine
20
may vary. For example, the precombustion chamber may have other than a generally circular cylindrical shape, such as an oval cylindrical shape.
Of course, a number of seals, connectors (such as nuts and bolts) and other elements may be used to achieve the objects of the invention. The particular elements used may depend upon the particular configuration of the engine
20
.
The precombustion
50
chamber and precombustion fuel and air mixing aspects of the invention may be applied to engines configured other than as illustrated and described. For example, such an arrangement may be applied to engines having a single cylinder. The engine of the invention also need not include a precombustion chamber
50
with each cylinder
32
. Instead, the arrangement of the invention may be used with a cylinder having normal intake and exhaust porting as is known in the art.
In one embodiment, instead of mounting the pistons in pairs to mounting sections of the crankshaft, each piston may be mounted to a different section of the crankshaft. Such an arrangement is advantageous where there are two cylinders or where it is desired to provide a number of cylinders in the same plane. Such an arrangement where the pistons are mounted in a “V” arrangement is illustrated in FIG.
31
.
In one embodiment, engine control or management devices or systems may be employed. For example, an O2 sensor may be used to monitor the exhaust of the one or more cylinders. The O2 sensor feedback may be used to control the timing and duration of fuel injection or spark timing.
The start of combustion of the fuel and air mixture may be either in the cylinder bore or in the precombustion chamber. As described above, in a preferred embodiment, combustion is initiated in the precombustion chamber. In this arrangement, combustion is initiated only shortly before or nearly at the same time the valve
92
is moved upwardly (to prevent damage to the precombustion chamber due to overexpansion).
The engine may include other features. For example, a turbo charger or supercharger may be used to pre-compress the intake air. An intercooler may be used to cool the incoming air so that it may be compressed to a higher density.
The principles of the invention may also be applied to an engine having a crankshaft which is non-translating (i.e. rotates about a fixed axis). In such event, however, the length of the rods and cylinder bores may be appropriately adjusted to permit the pistons to move a full range of motion and provide a desired compression ratio.
The embodiments of the invention have numerous advantages. As with conventional two-cycle internal combustion engines, one advantage is that a high power output is realized because each piston has a power stroke every cycle (instead of every other cycle as in a four-stroke engine). On the other hand, problems associated with conventional two-stroke or two-cycle engines are overcome.
First, problems associated with incomplete scavenging in two-cycle engines are overcome. A fresh air charge is not drawn into the cylinder while the exhaust is being exhausted. Instead, the exhaust is completely exhausted during the upward stroke of the piston. Only then is a fresh air charge admitted into the cylinder.
Unlike convention engines, combustion need not begin before the piston reaches top dead center, and thus there is no robbing negative force upon the upwardly rising piston. Instead, combustion may begin after the piston reaches top dead center. In part, this is due to the fact that combustion is permitted during nearly the entire downward stroke of the piston. In addition, because combustion begins in the precombustion chamber, the air and fuel mixture may combust and expand, generating a very high pressure. The highly pressurized mixture is preferably released when it reaches a maximum and at piston top dead center for maximum efficiency.
A higher engine efficiency is realized because the air and fuel charge which is admitted into the cylinder for combustion is at high heat and high pressure. As noted, the fresh air charge is first mechanically compressed by the piston and then thermally compressed within the precombustion chamber. The highly heated and compressed air charge permits more complete burning of fuel and greater energy output during combustion.
FIG. 30
is a graph which illustrates pressure of an air charge as it moves through the engine. As illustrated, the air charge enters the intake at substantially ambient pressure. The air charge is the compressed mechanically with the piston, and then thermally by the heat within the precombustion chamber. After fuel injection and delivery to the combustion chamber, the pressure beings to fall as the fuel and air are converted to mechanical energy. By comparison, in a conventional engine greater power is derived as a result of the higher temperatures and pressures and none complete burning of the fuel.
The engine is capable of operating at high speeds. The rods
54
are short, reducing destructive inertial forces. This is due, in part to the translation of the crankshaft
28
. Because the crankshaft translates, the piston mounting portion
86
more toward and away from the cylinder during the upward and downward movement of the pistons as a result of the rotation of the crankshaft. As a result, the piston rods
54
can be shorter while a large compression ration is still realized.
The lubricating system as described provides for efficient lubrication of the pistons without the need for complex mechanically or electrically powered pumps, external lines, coolers and similar elements. In addition, the lubricating system has the advantage that it is useful in cooling the pistons.
It will be understood that the above described arrangements of apparatus and the method therefrom are merely illustrative of applications of the principles of this invention and many other embodiments and modifications may be made without departing from the spirit and scope of the invention as defined in the claims.
Claims
- 1. A two-cycle internal combustion engine comprising a block, at least one cylinder head mounted to said block, a piston movably mounted in a bore defined by said cylinder head, said piston dividing said bore into a first variable volume intake chamber and a second variable volume combustion chamber, said cylinder head further defining a precombustion chamber, said precombustion chamber selectively in communication with said first variable volume intake chamber and said second variable volume combustion chamber, at least one valve member for selectively permitting a compressed charge of air to flow into said precombustion chamber from said first variable volume intake chamber and from said precombustion chamber to said second variable volume combustion chamber, and at least one fuel delivery element adapted to deliver fuel into said air for at least partial combustion in said second variable volume combustion chamber for moving said piston in said bore, said piston connected to a crankshaft and moving said crankshaft as a result of said movement in said bore.
- 2. The two-cycle internal combustion engine in accordance with claim 1 wherein said cylinder head comprises a body having a first end and a second end, a first member mounted at said first end and a second member mounted at said second end.
- 3. The two-cycle internal combustion engine in accordance with claim 2 wherein said first member comprises a plate having a passage there through, said plate connected to said block, and wherein said piston includes a rod extending from a head thereof, said rod extending through said passage through said plate into said block.
- 4. The two-cycle internal combustion engine in accordance with claim 1 including a first passage extending from said first variable volume intake chamber portion of said bore to said precombustion chamber and a second passage extending from said precombustion chamber to said second variable volume combustion chamber portion of said bore.
- 5. The two-cycle internal combustion engine in accordance with claim 4 including a valve located at least partially in said precombustion chamber, said valve having a first seal thereon for selectively sealing said first passage and a second seal thereon for selectively sealing said second passage.
- 6. An internal combustion engine comprising a block, at least one head connected to said block and defining a cylinder bore, a piston movably mounted in said cylinder bore, said piston connected to a crankshaft, said block including a first block gear and a second block gear, said crankshaft having a first end and a second end, at least one piston mounting portion located between said ends and positioned along a first axis offset from a second axis through said first and second ends, a first crankshaft gear located at said first end of said crankshaft, said first crankshaft gear smaller than said first block gear and engaging said first block gear, and a second crankshaft gear smaller than said second block gear and located at said second end of said crankshaft, said second crankshaft gear engaging said second block gear, whereby movement of said piston causes said crankshaft to rotate about said second axis and said second axis to move in a generally circular pathway.
- 7. The internal combustion engine in accordance with claim 6 wherein said first block gear comprises a passage through a first end portion of said block and a plurality of teeth extending into said passage from said block, and wherein said second block gear comprises a passage through a second end portion of said block and a plurality of teeth extending into said passage from said block.
- 8. The internal combustion engine in accordance with claim 6 wherein said crankshaft includes at least one crankshaft mounting portion between said ends and including at least one eccentric bearing supporting said at least one mounting portion, said at least one eccentric bearing connected to said block.
- 9. The internal combustion engine in accordance with claim 6 wherein said crankshaft includes a first crankshaft mounting portion and a second crankshaft mounting portion, a first eccentric bearing supported by said block and engaging said first crankshaft mounting portion and a second eccentric bearing supported by said block and engaging said second crankshaft mounting portion.
- 10. The internal combustion engine in accordance with claim 9 wherein at least one of said first and second eccentric bearings defines a cam surface.
- 11. The internal combustion engine in accordance with claim 6 further including an output shaft coupled to said first or second end of said crankshaft, said output shaft including a universal joint.
- 12. A lubricating system for a piston of an internal combustion engine, said piston having a head and a rod, a first end of said rod coupled to said head and a second end of said rod located opposite said first end thereof, a passage through said rod generally extending from said first end to said second end, an inlet leading from an exterior of said second end to said passage, at least one delivery passage located in said head and extending from said passage in head and returning to said passage in said rod, and an outlet from said passage in rod, at least one partition dividing said passage through said rod into an inlet passage leading from said inlet to said delivery passage and an outlet passage leading from said delivery passage to said outlet, and at least one lubrication directing element located in said inlet passage and outlet passage, said at least one lubrication directing element generally inhibiting the flow of lubricant from said delivery passage to said inlet and from said outlet to said delivery passage.
- 13. The lubricating system in accordance with claim 12 wherein said at least one lubrication directing element comprises a generally oval element, said element oriented at an angle with respect to said partition.
- 14. The lubricating system in accordance with claim 13 wherein said oval element has a first end and a second end, said first end located in said inlet passage and said second end located in said outlet passage.
- 15. The lubricating system in accordance with claim 14 including a cut out area located at said first and second ends of said oval element.
- 16. The lubricating system in accordance with claim 12 including a divider located in said passage in said rod, said divider defining a generally helical passage through said rod.
- 17. The lubricating system in accordance with claim 16 wherein said lubrication directing element is positioned in said helical passage and divides said passage into helical inlet passage and helical outlet passage.
- 18. A two-cycle internal combustion engine comprising a block having a first end and a second end, a crankshaft rotatably supported by said ends of said block, said crankshaft having a first end with a gear thereon engaging a first block gear at said first end of said block and said crankshaft having a second end with a gear thereon engaging a second block gear at said second end of said block, said crankshaft including at least one piston mounting portion, said at least one piston mounting portion extending along a first axis offset from a second axis through said ends of said crankshaft, said crankshaft rotatably supported by said block with at least one eccentric bearing permitting said crankshaft to rotate about said second axis and to translate, at least one piston connected to said at least one mounting portion of said crankshaft, said piston including a rod connected to said crankshaft and a head, said head located in a cylinder bore defined by a cylinder head connected to said block, said cylinder bore generally closed at a top end and a bottom end thereof, said head of said piston dividing said cylinder bore into a variable volume intake chamber below said head and a variable volume combustion chamber above said head, an intake port leading from an exterior of said engine to said variable volume combustion chamber and a valve adapted to selectively open and close said intake port, said cylinder head defining a precombustion chamber, a compression port leading from said variable volume intake chamber to said precombustion chamber, a bi-directional port leading from said precombustion chamber to said variable volume combustion chamber, at least one valve adapted to selectively open and close said compression port and bi-directional port, a fuel delivery mechanism adapted to deliver fuel into said precombustion chamber, and a cam rotated by said crankshaft and arranged to drive said at least one valve adapted to selectively open and close said compression port.
- 19. The two-cycle internal combustion engine in accordance with claim 18 wherein said block has four sides, a cylinder head coupled to each of said sides and a piston movably mounted in each of said cylinder heads, said pistons connected to said crankshaft.
- 20. The two-cycle internal combustion engine in accordance with claim 18 including a follower having a first end engaging said cam and a second end engaging a rocker, said rocker adapted to move said at least one valve adapted to selectively open and close said compression port and bi-directional port.
- 21. The two-cycle internal combustion engine in accordance with claim 18 including at least two opposing pistons, said pistons connected to one another about a mounting portion of said crankshaft.
- 22. A method of operating an internal combustion engine including a piston movably mounted in a cylinder bore, said piston connected to a crankshaft comprising:drawing an air charge into a variable volume combustion chamber below a head of said piston; compressing said air charge as said piston moves downwardly in said bore; releasing said compressed air charge into a precombustion chamber; heating said compressed air charge in said precombustion chamber; adding fuel to said heated and compressed air charge in said precombustion chamber; releasing said fuel and air from said precombustion chamber into a combustion chamber above said piston head; igniting said fuel and air mixture thereby driving said piston downwardly; and moving said piston upwardly driving exhaust from said combustion chamber.
- 23. The method in accordance with claim 22 including the step of rotating and translating said crankshaft to which said piston is coupled.
US Referenced Citations (7)