The present invention relates to a vane heat engine and in particular to a vane heat engine efficiently utilizing potential energy and having an adjustable expansion chamber wall so that the volume of the expansion chamber is adjustable.
U.S. Pat. No. 3,084,677 to Mitchell is titled Sliding Vane Type Rotary Steam Engine and relates to improvements in steam engines of the rotary type. U.S. Pat. No. 3,890,071 to O'Brien is titled Rotary Steam Engine. It shows a rotaty steam engine having a cylindrical housing with an eccentrically mounted cylindrical rotor therein. The rotor is provided with reciprocal vanes that are controlled by a fixed cam surface, and the inner surface of the housing has a flat chordal plate extending thereacross through which inlet and outlet passages are provided. The arrangement is such that the chambers between the inner rotor and the housing approximate an involute in order to take full advantage of isentropic expansion.
U.S. Pat. No. 4,758,137 to Kieper is titled Vane Type Variable Displacement Motor. It shows a vane type variable displacement motor comprising a body having an elliptical first bore, end caps with axial bores, an axial drive shaft journaled therethrough and a rotor on the shaft. A plurality of radial vanes are movably mounted upon and around the rotor and are biased toward the first bore and react to pressurized liquid delivered through intake and exhaust passages in the body. Rotative pistons upon the shaft within the end cap bores have a series of radial slots to receive the vanes whereby the pistons are adapted for axial movement relative to the vanes into the first bore for modifying the effective internal volume of the first bore and speed of shaft rotation. Pilot ports in the end caps are connected to a variable pressure source for biasing the pistons variably into the first bore.
U.S. Pat. No. 8,567,178 to Hartfield, Jr. is titled Positive Displacement Rotary Vane Engine. It shows an engine, which includes a positive displacement compression process, a variably fueled, continuous combustor and/or heat exchanger, and a positive displacement, work-producing expander. This arrangement avoids the traditional stochiometric mixture requirements utilized in spark-ignition based engines and the emission problems associated with diesel engines.
While the engines shown in each of these patents may work well for their intended purposes, they each may be improved upon.
Thus there exists a need for a vane heat engine that solves these and other problems.
The present invention relates to a vane heat engine and in particular to a vane heat engine efficiently utilizing potential energy and having an adjustable expansion chamber wall so that the volume of the expansion chamber is adjustable. The engine has a housing with an inlet and an outlet. A rotor with a plurality of vanes is provided to rotate within the housing. An adjuster is provided for adjusting the location of an expansion chamber wall. The position or location of the expansion chamber wall determines the volume within a plurality of compartments bound by the rotor, the expansion chamber wall and two of the plurality of vanes. The expansion wall can be made of a plurality of members, whereby the expansion wall is flexible along its longitudinal dimension yet strong perpendicular to the longitudinal dimension.
According to one advantage of the present invention, the size and shape of the expansion chamber is variable (as opposed to moving the location of the chamber or rotor).
Related, this advantageously allows the volumes of individual compartments to be sized appropriately to achieve desired compartment pressures at the end of the expansion cycle.
According to another advantage of the present invention, the expansion chamber wall can be made of a plurality of members. This advantageously allows the wall to be radially flexibly along the longitudinal or perimeter dimension of the wall, yet provide for stiffness and strength perpendicular to the wall.
According to another advantage of the present invention, mechanical adjusters can be provided for shaping the expansion chamber wall and providing support to the wall.
According to a further advantage yet of the present invention, one end of the expansion chamber wall is fixed and the other end is not fixed. In this regard, the non-fixed end is able to move relative to the rotor (and also relative to the housing cavity fixed outer wall) thereby increasing or decreasing the cavity volume.
According to a still further advantage of the present invention, as the ratio of input pressure to output pressure changes, the increasing and decreasing cavity size provided by the adjustable expansion chamber wall allows for full expansion of a gas within the cavity so that the pressure within the cavity can be equal or close to equal to the ambient pressure at the point of exhaust thereby increasing engine efficiency.
Related, the members are allowed to slide relative to each other. This allows the distal end (non-fixed end) to have an end profile that seals with the housing cavity fixed outer wall.
This radial flexibility allows each of the members to contact the outer wall to provide a good seal. In an alternative embodiment, one of the members can comprise a seal such as rubber for increased sealing effectiveness.
According to another advantage of the present invention, the rotor is in close proximity to the cavity wall between the outlet and inlet.
According to another advantage of the present invention, the expansion chamber has a radially expanding dimension at the entrance face, and either a constant or a radially expanding volume at the expansion face allowing the engine to efficiently harness potential energy of expanding gas as it causes the rotor to turn.
According to a still further advantage yet of the present invention, spring loaded vanes are operable with the adjustable expansion chamber wall. The spring loaded vanes are operable regardless of the position of the expansion chamber wall.
Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.
While the invention will be described in connection with one or more preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Looking now to
It is appreciated that the dimensions shown and described herein are preferred dimensions, and that alternative dimensions could be used without departing from the broad aspects of the present invention. Specifically, the engine could be larger or smaller. Also, there could be multiple inlets or outlets (vertically stacked or otherwise arranged), or there could be specifically sized and shaped inlets without departing from the broad aspects of the present invention.
Looking now at
The housing 60 has an outer wall 70. The outer wall 70 has an outside diameter of approximately 9 inches. The outer wall 70 preferably has several inner faces 71, 72, 73, 7475 and 76, as described below moving around the housing 60.
Face 71 is an entrance face. The entrance face preferably is recessed inward approximately 0.250 inch and is preferably 1.75 inches from the outside of the outside surface at the first end of the face. The entrance face preferably has a taper of approximately 0.125 inches along its length, wherein the face is recessed in approximately 0.375 inches and is inward from the outer wall approximately 1.625 inches at the second end. It is preferred that the taper is smooth, constant and continuous.
Face 72 is a ledge face, and drops off radially approximately 0.625 inches. From the entrance face 71. Face 72 is preferably perpendicular to the end of entrance face 71.
Face 73 is a continually radially expanding expansion face. In this regard, the expansion face has a starting thickness of approximately 1 inch. The expansion face has an ending thickness of approximately 0.500 inch. The decrease in diameter from start to end is preferably smooth and continuous.
Face 74 is a return face. A variable sized expansion wall (described below) contacts the return face 74. Return face is preferably flat. The face has a thickness of about 0.500 inches at the start of the face and a thickness of about 1.84 inches at the end of the face. Face 74 lies in a face plane. At the end of the face 74, the angle between the face and a line 68 dissecting the housing 60 through the center 69 is at an angle of approximately 96 degrees. Of course, this angle can be changed without departing from the broad aspects of the present invention. A face in this approximate angle provides a surface that the adjustable expansion wall can slide against without binding.
Face 75 is an exit face, and the outlet 67 is open through this face. Exit face 75 preferably has a flat profile. The exit face lies in an exit face plane. The exit face plane is about 166 degrees from a return face plane that the return face 74 lies in.
Face 76 is an annular face with a constant or uniform thickness of approximately 2 inches. Annular face 76 is between the outlet 66 and the inlet 67. The annular face 76 is preferably approximately 2.5 inches from the center 69 of the cavity 65.
Looking now at
Vanes 100, 101, 102, 103, 104, 105, 106 and 107 are removably received within slots 90, 91, 92, 93, 94, 95, 96 and 97, respectively, as seen in
While eight slots and vanes are illustrated herein, it is appreciated that more of fewer vanes and slots may be utilized without departing from the broad aspects of the present invention. Specifically, it is understood that it could be possible to use an engine with a single vane.
An expansion chamber 110 is provided within the cavity 65 between the rotor 80 and an expansion chamber wall 120 (as the rotor turns counter-clockwise within the cavity). The expansion chamber wall has a first end 121, a second end 122, a first side 123 and a second side 124. The chamber wall 120 is preferably formed from spring steel plates 130, 131, 132, 133, 134, 135, 136, 137, 138, 139 and 140 as seen in
The first end 121 is preferably secured in a fixed position to the entrance face 71 of the fixed outer wall as seen in
The minimum expansion position is illustrated in
Now looking at
Now looking at
Hence, it is illustrated that the chamber expands in volume at the entrance face, and either is held constant or increases about the expansion face.
It is appreciated that the vanes remain in contact with the expansion wall 120 regardless of the position of the expansion wall 120 within the cavity 65.
An adjuster 150 having five adjustable fluid tubes 151, 152, 153, 154 and 155 is further provided for adjusting the location of the wall 120 and also for providing support to the backside of the wall as seen in
Several compartments 160, 161, 162, 163, 164, 165, 166 and 167 are provided. Each compartment or cavity is bound by the rotor, the expansion wall and two vanes. In this regard, the size or volume of each compartment can change as the rotor rotates (depending on the location of the expansion wall). It is understood that in an embodiment having a single vane, that the vane could form a cavity with the expansion chamber wall, the rotor and an item other than a vane without departing from the broad aspects of the present invention. It is further understood that a single vane embodiment could be used in an embodiment wherein the inlet is controlled with a valve to control the time and duration during which the inlet is opened and closed.
The expansion of a single compartment or cavity is illustrated in
It is appreciated that the inlet pressure can be changed as well as the volume of the expansion chamber. In the minimum expansion position, the volume expands at the entrance face and is constant around the expansion face. In this regard, the variable in the P1×V1=P2×V2 equation is P1, which is the inlet pressure. The V1 is the volume at the entrance wall. P2 is the exhaust pressure (which could be atmospheric or otherwise) and V2 is the volume of the chamber at the exhaust. By adjusting the movable wall in and out, the ratio of the input cavity volume/output cavity volume is increased and decreased. This allows the gas to expand in a manner whereby maximum thermodynamic efficiency can be extracted from the system. If the temperature of the gas were to be held constant in accordance with the ideal gas law, PV=nRT, then P1×V1=P2×V2. Further, if known temperature drops do occur, this can be taken into account and the wall can be adjusted in order to increase efficiency.
It is appreciated that at the minimum expansion position, the volume of the chamber is constant as it moves about the expansion face. In this regard, the curve shown at the end of the second segment in
An inlet pressure gauge 601 and an outlet pressure gauge 602 are provided so that a processor 603 can calculate the respective pressures and make adjustments to the adjustable wall position and inlet pressure as necessary to achieve the desired pressure at the outlet in accordance with the pressure times volume equation as described above. In this regard, the output of the engine is variable as determined by the inlet pressure and adjustable wall position. It is further understood that temperature could be factored into the calculation to determine the proper inlet pressure and adjustable wall position.
Looking now at
A control 210 with a fulcrum 211 is provided. Rotation of the control 210 about the fulcrum 211 causes the first piece 190 to move relative to the second piece 200 and hence cause the wedges to ride up or down each other. It is appreciated that the slope of the wedges is lowest near the ledge face 72 and greatest near the return face 74. Hence, per unit of lateral band travel, the bands separate the farthest near the return face.
It is appreciated that adjustable expansion does not require constant expansion. In one position, the chamber expands only at the inlet face and is constant about the expansion face. The rate of increase of volume could also change to achieve a desired power output of the engine in response to a change in the ratio of input pressure to output pressure, or input/output pressure ratio.
Looking now to
Looking now to
Looking now to
It is appreciated that in this embodiment, as well as in the other embodiments, that there can be more or fewer adjusters without departing from the broad aspects of the present invention.
Looking now at
The housing 560 has a fixed outer wall 570. The fixed outer wall 570 has an entrance face 571, a transition point 572 (where the entrance face would meet an expansion chamber wall), an expansion face 573, a return face 574, an exit face 575 and an annular face 576. The return face 574 preferably follows a curved path. In this regard, the end of the expansion wall engages the face along the curved path ensuring smooth operation thereof.
Thus it is apparent that there has been provided, in accordance with the invention, a vane heat engine that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
This United States utility patent application claims priority on and the benefit of provisional application 61/974,353 filed Apr. 2, 2014, the entire contents of which are hereby incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
3084677 | Mitchell | Apr 1963 | A |
3889775 | Luscher | Jun 1975 | A |
3890071 | O'Brien | Jun 1975 | A |
4758137 | Kieper | Jul 1988 | A |
7931450 | Ueki et al. | Apr 2011 | B2 |
8118575 | Williamson et al. | Feb 2012 | B2 |
8545199 | Koller et al. | Oct 2013 | B2 |
8567178 | Hartfield, Jr. | Oct 2013 | B2 |
20050036897 | Kasmer | Feb 2005 | A1 |
20100232989 | Watanabe et al. | Sep 2010 | A1 |
20120000199 | Hartfield, Jr. | Jan 2012 | A1 |
20130089446 | Williamson et al. | Apr 2013 | A1 |
Number | Date | Country | |
---|---|---|---|
61974353 | Apr 2014 | US |