Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Title: VARIABLE STROKE MOTOR AND VALVE
Background of the Invention
Field of the Invention
The invention relates in general to a valve and associated piston actuated
motor, and, more particularly, to a variable stroke motor and valve rotated at
a
constant speed.
to
Description of the Prior Art
In the prior art internal combustion piston-type devices, it is known to
inject a liquid hydrocarbon into a piston assembly, draw the piston outward to
create a vacuum strong enough to vaporize the hydrocarbon, and then compress
i5 the hydrocarbon before ignition thereof. Since the ignition of the
hydrocarbon
gas typically creates waste material and uses up most of the oxidizer within
the
piston assembly, work must be performed to remove the waste material and
introduce fresh oxidizer into the piston assembly before more hydrocarbon may
be combusted.
a o One drawback associated with the internal combustion engine is the
pollution generated by such an engine. Additionally, since fuels typically do
not
burn cleanly in an internal combustion engine waste deposits build up within
the piston which can either decrease the efficiency of the engine or require
regular maintenance of the engine.
25 An additional drawback associated with internal combustion engines is
the range of speeds at which typical internal combustion engines operate.
Since
internal combustion engines operate based upon a predetermined stroke length,
the force of the combustion must be at least adequate to move the piston this
predetermined stroke length. The force, however, must not be too large,
3 0 otherwise components of the internal combustion engine may be damaged.
Although the "force" of the stroke may be manipulated, the length of the
stroke
in an internal combustion engine typically cannot be varied. Accordingly,
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vehicles powered by internal combustion engines typically require a clutch and
gearing to step up or step down the rotational energy produced by the internal
combustion engine.
The difficulties encountered in the prior art discussed hereinabove are
s substantially eliminated by the present invention. The present invention is
designed to provide a variable stroke motor with a constant speed rotating
valve
to increase efficiency and decrease the drawbacks associated with prior art
internal combustion engines.
to Summary of the Invention
According to the invention, a fluid valve system comprising a valve
housing forming a hollow cylinder; a first fluid input in fluid communication
with said hollow cylinder; a first fluid output in fluid communication with
said
hollow cylinder; a second fluid input in fluid communication with said hollow
15 cylinder; a second fluid output in fluid communication with said hollow
cylinder;
a shaft positioned within said hollow cylinder, said shaft being rotatable
between a first position substantially sealing off fluid communication between
said first fluid input and said first fluid output, and a second position
substantially sealing off fluid communication between said second fluid input
a o and said second fluid output; wherein said shaft is provided with a first
slot and
a second slot; wherein said first slot is oriented on said shaft in a manner
which
opens fluid communication between said first fluid input and said second fluid
output when said shaft is in said second position; wherein said second slot is
oriented on said shaft in a manner which opens fluid communication between
a s said first fluid input and said first fluid output when said shaft is in
said second
position; and means coupled to said shaft for rotating said shaft between said
first position and said second position.
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Brief Description of the Drawings
Fig. 1 is a side elevation in cross-section showing the valve assembly and
piston assembly of the present invention;
s Fig. 2 is a perspective view of the valve assembly and piston assembly of
Fig. l; and
Fig. 3 is an exploded view of the valve assembly and piston assembly of
Fig. 2.
Fig. 4 is a top view in cross-section showing the valve and piston
1 o assembly of Fig. 1.
Detailed Description of the Preferred Embodiment
With reference to the drawings, a variable stroke motor is indicated
generally as (10) in Fig. 1. As shown in Fig. 3, the variable stroke motor
is includes a valve housing (12). In the preferred embodiment, the valve
housing
(12) is constructed of aluminum and provided with a hollow cylinder (14) to
accommodate a valve shaft (16). The valve housing (12) is constructed to form
a
first fluid input (18) in fluid communication with the hollow cylinder (14)
and a
first fluid output (20) which is also in fluid communication with the hollow
z o cylinder (14). As shown in Fig. 1, the valve housing (12) is also formed
with a
second fluid input (22) and a second fluid output (24).
As shown in Fig. 3, the valve shaft (16) is provided with a first slot (26)
and a second slot (28). The valve shaft (16) is also provided with a first
ring seat
(30), a second ring seat (32), and a third ring seat (34). Provided on the
first ring
a5 seat (30), second ring seat (32), and third ring seat (34) are three Teflon
rings
(36), (38) and (40) which prevent the escape of fluid between the valve shaft
(16)
and hollow cylinder (14).
As shown in Fig. 2, secured to the valve housing (12) is a shaft rotator
(42) which is operably secured to the key (44) extending from the valve shaft
(16)
3 o shown in Fig. 3. The shaft rotator (42) may be a small electric motor or
any
similar rotation device known in the art.
As shown in Fig. 3, the first slot (26) and second slot (28) of the valve
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shaft (16) are disposed on opposite sides of the valve shaft (16).
Accordingly,
when the valve shaft (16) is positioned within the hollow cylinder (14) of the
valve housing (12), as shown in Fig. 1, the second slot (28) opens fluid
communication between the second fluid input (22) and the second fluid output
s (24). When the second slot (28) opens fluid communication between the second
fluid input (22) and second fluid output (24), as shown in Fig. 1, the first
slot (26)
is completely covered by the valve housing (12) (Figs. 1 and 3). The portion
of
the valve shaft (16) on the opposite side of the first slot (26), therefore,
seals off
fluid communication between the first fluid input (18) and first fluid output
(20).
Similarly, when the shaft rotator (42) rotates the valve shaft (16) one
hundred and eighty degrees, the first slot (26) opens fluid communication
between the first fluid input (18) and first fluid output (20), while the
portion of
the valve shaft (16) opposite the second slot (28) seals off fluid
communication
between the second fluid input (22) and second fluid output (28). In the
preferred embodiment, the slots (26) and (28) and the inputs (18) and (22) and
the outputs (20) and (24) are sized so that when the fluid communication
between the first fluid input (18) and first fluid output (20) is open, fluid
communication between the second fluid input (22) and second fluid output (24)
a o is closed. Similarly, when fluid communication between the second fluid
input
(22) and second fluid output (24) is open, fluid communication between the
f"first
fluid input (18) and first fluid output (20) is closed.
Secured to the valve housing (12) is a drive housing (46) which forms a
drive cylinder (48) as shown in Fig. 1. In the preferred embodiment, the drive
housing (46) is constructed of stainless steel seamless tubing. Preferably,
the
drive housing (46) is secured to a drive box (50) which, is preferably
constructed
of aluminum. Provided within the drive cylinder (48) is a piston (52). The
piston (52) is preferably constructed with an aluminum cap (54) and an
aluminum base (56). As the piston (52) is of a wobble-type, the piston (52) is
3 o provided with a plastic sealing ring (58) which allows the piston (52) to
pivot two
degrees from a position normal to the center axis of the drive cylinder (48),
while
maintaining a seal between the sealing ring (58) and the drive housing (46).
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A piston rod (60) preferably constructed of hardened steel is secured to the
piston (52) with a securement screw (62) (Fig. 1). As shown in Fig. 3, the
piston
rod (60) is provided with an eyelet (62) which fits within a yoke (64) of a
swing
arm (66). Provided within the eyelet (62) is a needle roller bearing (68) or
similar bearing known in the art to reduce friction. The needle roller bearing
(68) is positioned within the eyelet (62), the eyelet (62) positioned within
the
yoke (64) and a dowel pin (70) constructed of heat treated steel is positioned
through a first eyelet (72) of the yoke (64), the needle roller bearing (68),
and a
second eyelet (74) of the yoke (64). The dowel pin is preferably constructed
of
to heat treated steel to withstand the large pressures associated with
actuation of
the piston rod (60). The swing arm (66) is preferably constructed of hardened
steel and is provided with a large hole (76) to accommodate a pair of drive
sprags
(78). The drive sprags (78) are coupled to a drive shaft (80) in a manner
which
transfers rotational energy from the swing arm (66) to the drive shaft (80) on
the
Zs drive stroke and which allows the drive shaft (80) to "freewheel" relative
to the
swing arm (66) on the recovery stroke so that the drive shaft (80) is not
rotated
in the opposite direction. As shown in Fig. 2, the drive shaft (80) extends
through the drive box (50) to power a vehicle or any other drivable device.
Operably coupled in fluid communication with the first fluid input (18), is
a o a fluid pressure generator (82) (Fig. 2). In the preferred embodiment, the
pressure generator (82) is a steam generator, but the pressure generator (82)
may, of course, be any similar device. The fluid pressure generator (82) is
coupled to the first fluid input (18) via a transfer hose (84) (Figs. 2 and
3). In the
preferred embodiment, the second fluid output (24) is also coupled to the
fluid
25 pressure generator (82) by a supplemental transfer hose (86).
As shown in Fig. 2, the variable stroke motor (10) is also provided with a
supplemental valve and piston assembly (88). The supplemental valve and
piston assembly (88) is substantially similar in design to the assembly
described
above. As shown in Fig. 3, however, the valve shaft (16) is provided with a
third
3 o slot (90) and a fourth slot (92) positioned on the valve shaft (16) in
reverse of the
positions of the first slot (26) and second slot (28). This positioning of the
slots
(26), (28), (90) and (92) causes the piston (52), described above, to drive
when the
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piston (94) of the supplemental valve and piston assembly (88) is recovering,
and
to recover when the piston (94) of the supplemental valve and piston assembly
(88) is driving. This complimentary actuation of the pistons (52) and (94)
causes
the drive shaft (80) to be substantially continuously driven by one of the two
s pistons (52) and (94).
As shown in Fig. 4, two recovery springs (96) and (98) are provided to
return the swing arm (66), described above, and the swing arm (100) of the
supplemental valve and piston assembly (88) to a starting position. As each
swing arm (66) and (100) alternately moves to a starting position, the swing
to arms (66) and (100) move their respective pistons (52) and (94) to a
starting
position as well. The recovery springs (96) and (98) are secured to the drive
box
(50) around the drive shaft (80). Each recovery spring (96) and (98) is
provided
with a recovery arm (102) and (104) and a securement finger (106) and (108).
Once the recovery springs (96) and (98) are secured to the drive box (50), the
15 fingers (106) and (108) are positioned within holes (110) and (112)
provided in
the swing arms (66) and (100). As shown in Fig. 4, the drive shaft (80), is
coupled to the interior perimeters of a pair of drive sprags (114) which, in
turn,
are coupled on their exterior perimeters to the swing arm (100). The drive
sprags (114) are oriented so that as the swing arm (100) is driven by the
piston
a o (94), the drive sprags (114) transfer the rotational motion of the swing
arm (100)
to the drive shaft (80). During the recovery stroke, the drive sprags (114)
"freewheel" to allow the recovery spring (96) to return the swing arm (100) to
its
starting position without transferring a large amount of rotational energy to
the
drive shaft (80).
25 An anti-backlash sprag (116) is secured to the drive shaft (80) between
the swing arms (66) and (100) to further reduce the transfer of rotational
energy
between the swing arms (66) and (100) and the drive shaft (80). As shown in
Fig. 4, the anti-backlash sprag (116) is secured to the drive box (50) within
a
drive shaft opening (118) provided in the drive box (50) between the swing
arms
3 0 (66) and (100).
The anti-backlash sprag (116) is secured to the drive box (50) by
weldments or other similar securement means. The anti-backlash sprag (116) is
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similar in construction to the drive sprags (114), but is coupled to the drive
shaft
(80) in an opposite operational orientation relative to the drive sprags
(114).
Accordingly, when the swing arm (100) is in its drive stroke, the drive sprags
(114) transfer rotational energy of the swing arm (100) to the drive shaft
(80).
s During this drive stroke, the anti-backlash sprag (116) is in its
"freewheel"
orientation, allowing the drive shaft (80) to rotate freely. Once the swing
arm
(100) has finished its drive stroke, the recovery spring (96) returns the
swing
arm (100) to its starting position. As the recovery spring (96) rotates the
swing
arm (100), the drive sprags (114) are in their "freewheel" orientation which
to limits rotational energy transfer from the swing arm (100) to the drive
shaft (80)
and reduces the drag on the recovery spring (96).
The anti-backlash sprag (116) is provided to prevent any further rotation
of the drive shaft (80) in the direction of the swing arm (100) recovery. If
the
friction between the drive sprags (114) and drive shaft (80) is great enough
to
15 transfer some amount of rotational energy from the drive sprags (114) to
the
drive shaft (80) during the recovery stroke of the swing arm (100), the anti-
backlash sprag (116) prevents rotation of the drive shaft (80). Since the anti-
backlash sprag (116) is welded to the drive box (50), the anti-backlash sprag
(116) transfers any "backward" rotational energy of the drive shaft (80) to
the
a o drive box (50) to prevent rotation of the drive shaft (80) in the
direction of the
swing arm (100) recovery.
The anti-backlash sprag (116) continues to prevent backward rotation of
the drive shaft (80) until one of the swing arms (66) or (100) begins rotating
the
drive shaft (80) on the drive stroke. In this way, the anti-backlash sprag
(116),
a5 assures that the drive shaft (80) is rotated in only a single direction.
To operate the variable stroke motor (10) of the present invention, the
shaft rotator (42) is actuated to rotate the valve shaft (16) within the
hollow
cylinder (14). The fluid pressure generator (82) is then actuated to supply a
pressurized fluid, such as steam, to the first fluid input (18) and to the
3 o supplemental valve and piston assembly (88). The valve shaft (16) is
thereby
being rotated at a constant speed. When fluid is being applied at a low
pressure
to the first fluid input (18), only a small amount of fluid enters the drive
cylinder
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(58) as the first slot (26) opens fluid communication between the first fluid
input
(18) and first fluid output (20). This introduction of fluid into the drive
cylinder
(48) forces the piston (52) away from the valve housing (12). As the swing arm
(66) rotates, the eyelet (62) of the piston rod (60) pivots slightly as the
swing arm
(66) reciprocates. This pivoting of the piston rod (60) causes the entire
piston
(52) to tilt slightly relative to the drive cylinder (48). To reduce the
amount of
tilt, the piston (52) is arranged so that in both its starting position and
its
ending position the piston (52) is slightly tilted. This reduces the degree of
tilt of
the piston (52) when the piston is at the center of a full stroke. The swim
ar"~,
io (66) and piston rod (60) are preferably designed with lengths sufficient to
place
the piston (52) in a starting position wherein the piston (52) is tilted two
degrees
from normal, relative to the center axis of the drive cylinder (48).
To examine how the piston (52) tilts, it is desirable to examine a full
stroke of the piston (52), that is, when fluid is being applied to the first
fluid
i5 input (18) at full pressure. As the drive cylinder (48) begins to fill with
fluid the
piston (52) moves toward the swing arm (66) causing the piston (52) to move
away from the valve housing (12), thereby pushing the swing arm (66) which
begins to rotate. As the swing arm (66) rotates, the piston rod (60) pivots
within
the yoke (64) of the swing arm (66). The piston (52) continues to rotate until
the
a o piston (52) becomes normal to the center axis of the drive cylinder (48).
This
occurs when the piston (52) is one-quarter of the way through the full stroke
of
the piston (52).
As more fluid enters the drive cylinder (48), the piston (52) continues to
pivot away from the drive shaft (80) until the piston (52) is halfway through
its
25 full stroke as shown in Fig. 1. At this point, the piston (52) is two
degrees from
normal relative to the axis of the drive cylinder (48), but in a direction
opposite
the two degree orientation of the starting point. As the drive cylinder (48)
continues to fill with fluid, the swing arm (66) rotates further, until the
piston
(52) is three-quarters of the way through its full stroke. At this point the
swing
3 o arm (66) has rotated suff"iciently so that the piston (52) is again normal
to the
center axis of the drive cylinder (48). As the drive cylinder (48) continues
to fill
with fluid, the swing arm (66) continues to rotate, and the piston (52) moves
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toward a position two degrees from normal relative to the center axis of the
drive cylinder (48). This two degree tilt is in the same direction as the two
degree from normal orientation of the piston (52) at the starting point of the
full
stroke. At full fluid pressure, this full stroke occurs every time fluid
communication is opened between the first fluid input (18) and the first fluid
output (Fig.3).
Accordingly, instead of orienting the piston (52) normal to the center axis
of the drive cylinder (48) in the starting position and pivoting the piston
(52)
through a large angle as the swing arm (66) rotates through its cycle, the
piston
to (52) is oriented two degrees from normal to start. In this way the piston
(52)
starts at a position two degrees from normal, cycles through a normal
position, a
position two degrees from normal in the opposite direction, another normal
position, and finally a position two degrees from normal in the same direction
as
the starting position. The total amount of deviation from the normal position
is
i5 thereby kept to a minimum throughout the full stroke.
Although the variable stroke motor (10) is fully capable of cycling through
the full stroke noted above, this full stroke is only realized under full
fluid
pressure. When only a small amount of pressure is being applied to the first
fluid input (18), the piston (52) moves through a much shorter stroke cycle.
As
z o the pressure of the fluid supplied by the fluid pressure generator (82)
increases,
a larger amount of fluid passes from the first fluid input (18), through the
first
fluid output (20) and into the drive cylinder (48) with each rotation of the
valve
shaft (16). This larger amount of fluid entering the drive cylinder (48) moves
the
piston (52) more quickly, thereby generating a longer and longer stroke. The
z5 swing arm (66) translates this longer stroke into a greater rotation of the
drive
shaft (80). Since the shaft rotator (42) rotates the valve shaft (16) at a
constant
speed, each cycle takes the same amount of time, regardless of the pressure of
the fluid being applied. Accordingly, a greater rotation of the drive shaft
(80) in
the same amount of time translates into a greater speed of the drive shaft
(80).
3 o For each rotation of the valve shaft (16), the second slot (28) provided
on
the valve shaft (16) opens fluid communication between the second fluid input
(22) and second fluid output (24) one time (Fig. 1). During this period of
time,
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the force of the recovery spring (96) causes the swing arm (66) to push the
piston
rod (60) into the piston (52), thereby pushing fluid out of the drive cylinder
(48)
through the second fluid input (22) and second fluid out (24). The fluid is
thereafter returned to the fluid pressure generator (82) through the
s supplemental transfer hose (86), so that the fluid can again be pressurized
and
recirculated through the motor (10) (Fig. 2). As the piston (52) is being
driven,
the supplemental valve and piston assembly (88) is working in a reciprocating
manner, to drive the drive shaft (80) when the piston (52) is in its recovery
stroke. As noted above, the anti-backlash sprag (116) prevents the swing arms
i o (66) and (98) from transferring rotational energy to the drive shaft (80)
during
their recovery stroke.
Since the valve shaft (16) is rotated at a constant speed, varying the
amount of fluid pressure entering the first fluid input (18) causes the piston
(52)
to stroke a longer distance, and thereby drive the drive shaft (80) a greater
15 distance during the same interval. The fluid pressure generator (82) may be
provided with a heating adjustment control (120), such as a propane valve, to
vary the amount of heat delivered to the fluid pressure generator (82) and,
thereby, the pressure of the fluid. Accordingly, the variable stroke motor
(10)
can directly convert a larger amount of heat energy into a faster rotation of
the
a o drive shaft (80).
The foregoing description and drawings merely explain and illustrate the
invention, and the invention is not limited thereto, except insofar as the
claims
are so limited, as those skilled in the art who have the disclosure before
them
will be able to make modifications and variations therein without departing
25 from the scope of the invention. For example, it is anticipated that any
number
of supplemental valve and piston assemblies may be coupled to the drive shaft
(80), and that a wide variety of dimensions are available for the fluid inputs
and
fluid outputs of the valve housing and for the slots in the valve shaft.
io
