TECHNOLOGY
The invention is to be applied as pump, motor, compressor or thermodynamic engine.
OBJECTS OF THE INVENTION
A design and way of constructing a simple engine with no valves and low restrictions. Low manufacturing cost, high durability, robust sealing, lubrication and cooling. For application as thermodynamic engine: variable compression, high swirl for fast combustion, low emissions, high speeds, high fuel efficiency and high specific power.
BACKGROUND OF THE INVENTION
The simple geometry of the reciprocating piston engine has made it the dominant choice for pumps, compressors and combustion engines. Demands on efficiency and pollution have however increased complexity and added many auxiliary devices, and further improvements can only be made at great costs. A more adaptable simple geometry is sought after, that will allow higher thermodynamic efficiency by having faster combustion, variable compression and less restrictions to gas flow, maintaining at the same time proper sealing, lubrication and cooling.
U.S. Pat. No. 1,972,302 (Hutchington M. R., 04-09-1934), describes a pump with rockers and a rotor with intake and exhaust ports, with seals at the tips of the rockers. U.S. Pat. No. 1,983,033 US (Hutchington M. R., 04-12-1934) describes a pump with rockers and a flexible rotor, with the flexible rotor allowing for proper sealing. U.S. Pat. No. 2,006,298 (Hutchington M. R., 25-06-1935) describes pumps with a rotor and rocking elements with rollers creating a seal. A specific feature of all these pumps is that the distance between the two rocker-rotor contact points is constant. Another description of machines of this type is given in German Patent DE 1,401,391 (A. J. Ignacio,21-10-1968). U.S. Pat. No. 3,186,385 (Walker H., 01-06-65) shows such an engine with a elliptical rotor, and two rockers, with ports inside the rotor, describing the advantages as 4 stroke engine.
In all these inventions the rocker has fixed contact zones and the distance between the two rocker-rotor contact zones is constant. In our invention the two rocker contact zones move along the flat surface of the rocker, and the distance between the two rocker-rotor contact zones is not constant. A first advantage of this being much lower thermal pressure on the seal and distributed wear on the rocker. Also the geometry now allows for relatively larger variable volumes .
U.S. Pat. No. 3,302,870 (Schell, Carl M, 1967-02-07) describes a pump with an elliptical rotor and two “oscillatable rocker members”. The patent however fails to describe a construction method for the rockers, which is not obvious for someone skilled in the art, who will find it difficult if not impossible to construct an engine with the information provided.
We present in this document the construction of engines, including asymmetric and non-elliptical rotors, with rockers with two perpendicular arms, which each have a flat contact zone towards the rotor, and have their juncture point, which is also their center of rotation, at a distance from the center of rotation of the rotor of squareroot(s*s+t*t), with s halve the length and t halve the width of the rotor. That these engines can be constructed follows from the insight that the junction point of any straightedge encompassing any ellipse creates a circle (Apollonius-Fermat circle).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 rotation of elliptical rotor and two straightedged rockers
FIG. 2 planar view of engine with non-elliptical rotor
FIG. 3 rotation of non-elliptical rotor in engine (e.g. HCCI)
FIG. 4 side views of FIG. 2
FIG. 5 side views of rotor of FIG. 2
FIG. 6 side views of rocker of FIG. 2
FIG. 7 side views of housing and top seal of FIG. 2
FIG. 8 geometry of rotor and rocker
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-section of a machine comprising in essence of one rotor(1), two rockers (3) and a housing (10), creating inside the housing eighth separate variable volumes. One volume between each rocker and the rotor (5),(7), two volumes between the first rocker and the housing (5a),(8a), two volumes between the second rocker and the housing (6a),(7a) and two volumes between housing, rotor and rockers (6),(8), all volumes being constrained in the axial direction by the housing(10) at the bottom and a plate or co-rotating seal at the top, which in case of uniform cross-sections would be flat. In case the cross-sections linearly increase in size from bottom to top, the axes of the rockers are no longer parallel to the rotating axis of the rotor, but the arms of the rockers will still make a right angle in any plane perpendicular to the rotating axis of the rotor, but will make an obtuse angle in any plane perpendicular to the respective rocker axis. Shaping the bottom and top bodies spherically, with the rotor axis and both rocker axes normal to the spherical shapes, a full enclosure of the eighth volumes can be guaranteed. An advantage of this more complex construction could be expansion towards one end.
In operation, the rotor (1), here shown an ellipse, rotates around an axis (2), and contacts two rockers (3), that pivot around their axes (4) inside a housing (10). For an ellipse, with major semi-axis t and minor semi-axis s, it can be shown that a pivoting straightedge, centered at a distance of squareroot {t squared plus s squared} will always have two, and only two contact points (9). As shown here, it is sufficient that the rocker has a straightedge shape only on the contacting path with the ellipse. In this way, four expanding and compressing internal volumes (5), (6), (7) and (8) are created, which can be filled or emptied through openings in the rotor, the straightedges, top or bottom. Additionally four secondary expanding and compressing volumes are created (5a), (6a), (7a) and (8a), between the housing and the straightedges. Here shown are four stages of one quarter of a rotor rotation, in which top and bottom volumes (5) and (7) expand from minimum to maximum, right and left volumes (6) and (8) contract from maximum to minimum, secondary volumes (5a) and (7a) are first expanding and then contracting, and secondary volumes (6a) and (8a) are first contracting and then expanding. Mirroring and reversing the order of the pictures can easily show the other three quarters of the rotor rotation. Applications can be for instance as pump, compressor, steam or Stirling engine.
A not so obvious part of this invention is the use as a progressive cavity pump, made by stacking sections on top of each other. We could do this by taking sections according to each picture of FIG. 1 with certain thickness, aligning the rotor sections on top of each other as if it were extruded, and rotating housing and rockers. Looking in we would see a cavity progressing when the rotor is turned. Of course with more sections with smaller angles between each next section and the previous, the cavity shapes can be more continuous axially. This could be extended to continuously shaped cavities using flexible rockers spiraling around the rotor. If we would increase or decrease the shape of rotor and rockers linearly from top to bottom, as described above, we could have expansion respectively compression axially as well. Of course alternatively all rockers could be stacked axially on top of each other with all rocker axes in parallel along two straight lines , which would allow for a simple to machine or extrude housing, but now with a twisted rotor.
In FIG. 2 a possible application is shown with a non-elliptical rotor (11) with inlet (21) and exhaust (22). The rotor has a bearing (12) and the rockers (13) have bearings (14) and are rotating inside the housing (20). Together they create volumes (15), (16), (17) and (18), and secondary volumes (15a), (16a), (17a) and (18a). The contact areas on the rockers here are made of separate glide plates (19) that act as mating surfaces for the rotor material, and act as sideway seals to compensate for manufacturing tolerances and wear. Inside the housing (20) and rockers (13), and through the bottom of housing (20), cylindrical bodies (24) are inserted, which can move along their axis, and which can change the expansion ratio's of volumes (15), (16), (17) and (18). In, on, or instead of these bodies (24), spark plugs (25), fuel injectors (23), valves and other devices can be inserted, for instance to facilitate venting, inlet/exhaust timing, ignition timing, addition or recirculation of gasses or fuel. Next to the glide seals (19), each primary volume (15), (16), (17) and (18), is sealed from the top and bottom by seals on the housing (26), rockers (27) and rotor (28), pressed down by the top seal (31) and body (33) (as shown in FIG. 7). Lubricating oil is supplied to the gliding plates by bodies (29) or from inside the rockers (13). Cooling and lubricating fluid can be transported in the rotor (11) through the bearing (12) radius, inside the rockers (13) through their bearing (14) radii, and inside the housing (20). Additional (e.g. steam) cooling can be applied through the secondary volumes (15a), (16a), (17a) and (18a), possibly creating additional power, and possible air cooling along the rotor(11) axis, heat pipes and cooling fins. Bearings can be large, long and robust to accept fast combustion. Concatenation of units can minimize vibrations. Application for instance as Controlled Auto Ignition (HCCI) combustion engine.
In FIG. 3 half a rotation is shown of the configuration of FIG. 2
In FIG. 4 several views are shown of the configuration of FIG. 2
In FIG. 5 several views are shown of the rotor of configuration of FIG. 2
In FIG. 6 several views are shown of a rocker of configuration of FIG. 2. The glide plates (19) are inserted into recesses, where they can move within the recesses, and be pressurized externally or through openings (30) by combustion gasses.
In FIG. 7 the housing (20) and top cover (33) are shown. If tolerances allow, a fixed top plate (33) is sufficient. Otherwise, the top plate (33) and seal (31) can co-rotate with the rotor and take up axial tolerances and wear. In this case a small hole (32) can be used, allowing high pressure combustion gasses to enter, to pressurize the seal downwards towards the rotor, pivoting bodies and housing.
In FIG. 8 a cross-section of a rotor (41) is shown, in a plane perpendicular to its rotating central axis, its point-symmetric boundary curve made up out of (infinitesimal) sections of ellipses with equal origin, with t′*t′+s′*s′=R*R, with f=t(m) the maximum semi-axis and s′=s(m) the minimum semi-axis of an ellipse, both function of the origin based vector m of the boundary curve, and R the distance between central axis and axis of a rocker(44) in this cross-section plane, where on the boundary an inscribed rectangle (46) can be defined, such that (a,b), (−a,b), (a,−b) and (−a,−b), lie on the boundary, with a+b=R. The boundary curve of the rotor has a continuous mapping by its normal vector n, (−pi<angle(n)<=pi) to the origin based vector m of a boundary point (−pi<angle(m)<=pi), where the mapping can be bijective (one-to-one) as on point (36) of rotor (42), or surjective (one-or-more-to-one) as on point (35) and (35a) of rotor (41). In either case the boundary can be cut up into connected smooth sections (34) and (34a), and the direction of rotation of the normal vector n follows the direction of rotation of m on the boundary curve. In effect, the straightedge is the operator, mapping one section (34) on the next section (34a), and this section (34a) on the next (34), continuing back to the first section. This means shapes will be point symmetric (45) and for any given phi, a part of a boundary curve with m defined for phi<angle(n)<=phi+pi/2 defines the whole boundary curve.
Shown is an ellipse (43), which could be defined for any point of the boundary curve, by the point and its normal vector (37) and a perpendicular normal vector (38) at another point on the boundary. This meaning a straightedge (44) would contact these points precisely. Within some mathematically definable boundaries, tolerances and some curvature can be allowed on the straightedge (47), which will slightly differently map one point on the boundary, to another point on the boundary. A remaining property is that, on each arm of the straightedge, a plane through the rocker axis and any rocker contact point at distance sqrt(2)*a will go through any rocker contact point at sqrt(2)*b, and the cross-section lines of these contact planes of the two arms with a plane perpendicular to the central axis are perpendicular. Even though approximate, the rotor will now not be made up out of (infinitesimal) ellipses as describe above, but will be close.
Patent Application
20130259731
