NOT APPLICABLE
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The following disclosure relates generally to machines and apparatuses having axial piston arrangements and, more particularly, to apparatuses and methods for converting reciprocating linear motion of one or more pistons into rotary motion of an associated shaft oriented in parallel to the piston motion.
Various apparatuses are known that convert movement of a working fluid within a changeable cylinder volume into rotary motion of an input/output shaft. Conventional internal combustion engines, compressors, and pumps are just a few of such apparatuses. In conventional arrangements, the pistons are connected via connecting rods to a crankshaft that rotates on an axis oriented perpendicular to the direction of travel of the piston.
The theoretical advantages of the axial piston arrangement have been well understood for many years, but no prior effort has succeeded in the marketplace. The primary difficulty in implementing an axial piston engine is in the means provided for preventing rotation of the motion converter, or as commonly referred to, the “wobble plate.”
It is an object of the invention to reduce friction losses in internal combustion engines and the like.
Another object of the invention to provide for variable compression ratio in internal combustion engines.
A further object of the invention is to provide a piston motion that is harmonic in nature and can be readily balanced and thereby reduce vibration.
It is an additional object of the invention to provide an improved means for preventing the rotation of the motion converter in an axial piston machine.
Another object of the invention is to provide a means for preventing the rotation of the connecting rods in an axial piston machine.
Yet another object of the invention is to provide for a one-piece or rigidly attached piston and connecting rod in an axial piston machine.
The following disclosure is directed to apparatuses and methods for converting reciprocal linear motion of one or more pistons into rotary motion of an output power shaft whose rotational axis is parallel to ther motions of the pistons or, conversely, for converting rotary motion of a similarly configured input shaft into reciprocal linear motion of one or more pistons. Various embodiments of the invention can be applied to internal combustion engines, external combustion engines, air compressors, air motors, liquid fluid pumps, and the like where movement of a working fluid within a volume-changing cylinder results from/in rotary motion of an input/output shaft. In contrast to conventional engines, compressors, and pumps where the crankshaft's rotational axis is perpendicular to the motions of the pistons, an axial piston apparatus configured in accordance with embodiments of the present invention can have one or more cylinders aligned in parallel with the rotational axis of the input/output shaft. As described in greater detail below, such a configuration can further include the capability to dynamically vary the compression ratio in the cylinders to alter the performance characteristics of the apparatus.
Certain embodiments of the apparatuses and methods described herein are described in the context of fluid pumps, fluid compressors, and internal combustion engines of both two- and four-stroke cycle designs. Accordingly, in these embodiments, the invention can include one or more features often associated with internal combustion engines, fluid pumps, or compressors such as fuel delivery systems, ignition systems, and/or various other engine/pump control functions. Because the basic structures and functions often associated with internal combustion engines, fluid pumps, fluid compressors and the like are known to those of ordinary skill in the relevant art, they have not been shown or described in detail here to avoid unnecessarily obscuring the described embodiments of the invention.
Certain specific details are set forth in the following description and in
In the drawings, identical reference numbers identify identical or at least generally similar elements. To facilitate the discussion of any particular element, the most significant digit or digits in any reference number refers to the figure in which that element is first introduced. For example, element 130 is first introduced and discussed in reference to
In another aspect of this embodiment, pistons 112 reciprocate back and forth within the cylinders 110 parallel to the Z-crank rotational axis 131. The pistons 112 are connected via connecting rods 114 to a “wobble-plate” or motion converter 120. As described in greater detail below, the motion converter 120 is rotatably attached to the Z-crank 130 about a nutation axis 133 such that the Z-crank 130 is free to rotate with respect to the motion converter 120 about the nutation axis 133. Accordingly, reciprocating motion of the pistons 112 in the cylinders 110 causes the motion converter 120 to nutate or wobble (but not rotate) relative to the Z-crank rotational axis 131.
In a further aspect of this embodiment, the apparatus 100 also includes a reaction control shaft 150 slidably engaging the motion converter 130. As explained in greater detail below, the reaction control shaft 150 restricts rotational movement of the motion converter 130 while allowing the motion converter 130 to nutate relative to the Z-crank rotational axis 131. The reaction control shaft 150 is configured to accommodate this nutation by rotating about an axis 151 as the Z-crank 130 rotates about its rotational axis 131. A gear train 160 controls motion of the reaction control shaft 150 relative to the Z-crank 130.
In operation, reciprocating motion of the pistons 112 within the cylinders 110 causes the motion converter 120 to nutate relative to the Z-crank rotational axis 131. Although the motion converter 120 nutates, it does not rotate a significant amount. Nutation of the motion converter 120 causes the Z-crank 130 to rotate relative to the motion converter 120 about the nutation axis 133. Such motion also causes the Z-crank 130 to rotate about the Z-crank axis 131. While the Z-crank 130 rotates, the reaction control shaft 150 also rotates about its axis 151 (e.g., at twice the Z-crank rotational speed) to accommodate the nutational movement of the motion converter 120 while restricting rotational movement of the motion converter 120.
Accordingly, in an internal combustion engine embodiment, combustion of fuel gases in the cylinders 110 can impart linear motion to the pistons 112 which in turn causes the motion converter 120 to wobble or nutate relative to the Z-crank rotational axis 131 providing rotational shaft-power at the Z-crank 130. This shaft-power can be utilized for any one of many applications including propelling air, land, and sea vehicles. Alternatively, when used as a pump or air compressor, shaft-power can be applied to the Z-crank 130 causing it to rotate about the Z-crank rotational axis 131 and thereby nutate the motion converter 120. Nutation of the motion converter 120 in turn causes axial motion of the pistons 112 in the cylinders 110. Such motion can be used to pump water, air or another fluid to or from a reservoir or source (not shown) for many applications.
In yet another aspect of this invention, the axial arrangement of the cylinders 110 relative to the Z-crank rotational axis 131 can advantageously facilitate compression ratio changes within the cylinders 110. For example, in one embodiment the apparatus 100 can include a support plate 140 that provides rotational support to the Z-crank 130 and the reaction control shaft 150. In the illustrated embodiment, the support plate 140 can be axially movable relative to the cylinders 110 back and forth parallel to the Z-crank rotational axis 131. Accordingly, as the support plate 140 moves toward the cylinders 110, the clearance between the top of the pistons 112 and the top of the combustion chamber within the cylinders 110 is reduced. As a result, such movement of the support plate 140 causes the compression ratio within the cylinders 110 to increase. Similarly, movement of the support plate 140 away from the cylinders 110 causes the compression ratio within the cylinders 110 to decrease. As will be appreciated by those of ordinary skill in the relevant art, controlling the compression ratio within the cylinders 110 in the foregoing manner can advantageously be used to alter or optimize various performance aspects of the axial piston apparatus 100.
In one aspect of this embodiment, the axial piston apparatus 100 can include an actuator 142 operably connected to the support plate 140, and an engine control unit 144 (“ECU” 144) that provides control inputs to the actuator 142. In one embodiment, the actuator 142 can include a hydraulic actuator configured to move the support plate 140 back and forth relative to the cylinders 110. In other embodiments, other types of mechanical, hydraulic, pneumatic and other types of actuators can be used to move the support plate 140 in response to inputs from the ECU 144. The ECU 144 of the illustrated embodiment can include one or more facilities for receiving engine operating information and outputting control signals to the actuator 142. For example, in one embodiment, the ECU can include a processor and a controller. In other embodiments, the ECU can include other functionalities. In yet another embodiment, the ECU 144 may be at least substantially similar to ECUs for controlling conventional internal combustion engines. In this embodiment, however, the ECU 144, in addition to controlling engine functions such as fuel intake, ignition timing, and/or valve timing, can provide additional output signals to control the actuator 142 and move the support plate 140 in response to one or more of the engine operating parameters. In a further aspect of this embodiment, one or more engine sensors 146 can provide engine operating parameter input to the ECU 144. Such engine sensors can include, for example, airflow rate, combustion and/or exhaust temperatures, throttle position, vehicle speed, etc.
In a further aspect of this embodiment, a variable compression axial piston engine in accordance with the present invention can be utilized to optimize engine performance to suit different operating conditions. For example, when the axial piston engine is operated at idle speeds, the compression in the combustion chambers can be reduced to enhance fuel efficiency. Alternatively, at higher RPMs, the compression within the combustion chambers can be increased. In other embodiments, the variable compression aspects of the present invention can be utilized in other ways to increase efficiency or performance.
The gear train 160 introduced above with reference to
In another aspect of this embodiment, the motion converter 120 has a centerbore 422 including one or more bearings (e.g., needle bearings) configured to rotatably receive the Z-crank bearing surface 432. The motion converter 120 can further include a reaction control bearing bore 424 radially offset from the centerbore 422 and configured to rotatably receive the reaction control bearing 352. The reaction control bearing 352 can similarly include a control shaft bore 454 configured to slidably and rotatably receive the offset bearing surface 351 of the reaction control shaft 150. The reaction control shaft gear 266 is fixed to one end of the reaction control shaft 150 and is configured to be operably engaged with the Z-crank gear 262 fixed on the Z-crank 130 proximate to the aft bearing surface 435.
In yet another aspect of this embodiment, the Z-crank 130 can include a counter-weight 534 laterally offset from the Z-crank rotational axis 131. If required or desirable, the counter-weight 534 can be used to dynamically balance the motion converter/Z-crank assembly.
In another aspect of this embodiment, the motion converter 120 can include needle bearings 628 received in the motion converter bore 422. The needle bearings 628 facilitate rotational motion of the Z-crank 130 relative to the motion converter 120. In other embodiments, other bearings in other configurations can be used to provide rotational freedom of the Z-crank 130 relative to the motion converter 120.
In a further aspect of this embodiment, the reaction control bearing 454 includes a ball bearing 752 and a retaining ring 754. The ball bearing 752 is received on the reaction control bearing 352 at an angle relative to the reaction control bearing bore 454. In a further aspect of this embodiment, the angle of the ball bearing 752 accommodates the nutational movement of the motion converter 120 relative to the reaction control shaft 150 as the Z-crank 130 rotates. In addition, the ball bearing 752 allows the reaction control bearing 352 to rotate relative to the reaction control bearing bore 424 (
Prior to assembly of the reaction control shaft 150 (for example, prior to installing the first counterweight 756), the bearing surface 351 of the reaction control shaft 150 is inserted through the reaction control bearing bore 454 of the reaction control bearing 352. The first counterweight 755 can then be installed on the reaction control shaft 150.
The foregoing discussion describes one embodiment of the present invention for restricting rotational movement of the motion converter 120 as it nutates relative to the Z-crank rotational axis 131 (
In one aspect of this embodiment, the anti-rotation gear train 860 (the “gear train 860”) includes a fixed gear 862, a first planetary gear 864, a second planetary gear 866, and a motion converter gear 868. The fixed gear 862 can be fixedly mounted to a lower portion of the Z-crank 830 and meshed with the first planetary gear 864. In one embodiment, the fixed gear 862 and the planetary gear 864 can be straight gears. In other embodiments, these gears can have other configurations. In another aspect of this embodiment, the first planetary gear 864 can be fixedly mounted on a common shaft with the second planetary gear 866. Accordingly, the first and second planetary gears 864 and 866 are fixed relative to each other and rotate about a common axis 835. In a further aspect of this embodiment, the second planetary gear 866 can be beveled or tapered to mesh with the correspondingly tapered motion converter gear 868. The motion converter gear 868 can be rotatably mounted (e.g., with needle or roller bearings) to a bearing surface 832 of the Z-crank 830. Further, the motion converter gear 868 can be fixedly attached to the motion converter 920.
An example of the operation of the gear train 860 will now be explained in accordance with an embodiment of the invention in which a combustion force F drives the pistons 812 to provide shaft-power output from the Z-crank 830. In this embodiment, combustion gases move the pistons 812 causing the motion converter 920 to wobble or nutate relative to the Z-crank axis 931. As the motion converter 920 nutates, it causes the Z-crank 830 to rotate about its rotational axis 931. Simultaneously, however, the gear train 860 prevents the motion converter 920 from rotating relative to the nutational axis 833. Rotation of the motion converter 920 is prevented by the motion converter gear 868 which is fixed relative to the motion converter 920 and engaged with the second planetary gear 866. The second planetary gear 866 is fixed relative to the first planetary gear 864 which in turn meshes with the fixed gear 862. In a further aspect of this embodiment, the ratio of the fixed gear 862 to the first planetary gear 864 should be equal to the ratio of the motion converter gear 868 to the second planetary gear 866. When this ratio is met, the gear train 860 as illustrated in
If the motion converter 920 is allowed to rotate freely about the nutation axis 833 as the Z-crank 830 rotates, then the motion converter 920 cannot convert linear motion of the pistons 812 into torque at the Z-crank 830 nor, conversely, can the motion converter 920 convert torque from the Z-crank 830 into linear motion of the pistons 812. Accordingly, in an ideal situation, the motion converter 920 will move in a purely nutational motion without any substantial rotation.
Various aspects of the axial piston apparatuses described above can be combined to create engine and/or pump configurations in addition to those described above. For example, various dual-Z-crank configurations can be achieved in accordance with the present disclosure. Such dual-Z-crank configurations can include pistons facing towards each other in pairs sharing common cylinders. Alternatively, such configurations can include opposed cylinders facing outwardly relative to each other similar to two axial piston apparatuses positioned back-to-back. Such configurations may be advantageously self-counterbalancing and not require further counterbalancing via weights, etc.
The foregoing description of the embodiments of the invention are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those of ordinary skill will recognize. For example, although certain functions may be described in the present disclosure in any particular order, and alternate embodiments, these functions can be performed in a different order or, alternatively, these functions may be performed substantially concurrently. In addition, the teachings of the present disclosure can be applied to other systems, not only the representative axial engine, compressor, pump systems described herein. Further, various aspects of the invention described herein can be combined to provide yet other embodiments.
Accordingly, aspects of the invention can be modified, if necessary or desirable, to employ the systems, functions, and concepts of conventional engine, pump and/or compressor apparatuses to provide yet further embodiments of the invention. These and other changes can be made to the invention in light of the above-detailed description. Accordingly, the actual scope of the invention encompasses the disclosed embodiments described above and all equivalent ways of practicing or implementing the invention.
Unless the context clearly requires otherwise, throughout this disclosure the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.
The following examples represent additional embodiments of axial piston apparatuses configured in accordance with the present disclosure.
Number | Name | Date | Kind |
---|---|---|---|
575991 | Schonheyder | Jan 1897 | A |
748559 | Peet | Dec 1903 | A |
773206 | Hall | Oct 1904 | A |
780549 | Callan | Jan 1905 | A |
812636 | Callan | Feb 1906 | A |
821546 | Smallbone | May 1906 | A |
868947 | Smith | Oct 1907 | A |
876202 | Lege | Jan 1908 | A |
893181 | Macomber | Jul 1908 | A |
933316 | Macomber | Sep 1909 | A |
1038537 | Dexter | Sep 1912 | A |
1042018 | Macomber | Oct 1912 | A |
1233635 | Almen | Jul 1917 | A |
1255973 | Almen | Feb 1918 | A |
1282179 | Brackett | Oct 1918 | A |
1282180 | Brackett | Oct 1918 | A |
1300098 | Almen | Apr 1919 | A |
1316679 | Brackett | Sep 1919 | A |
1346672 | Patton | Jul 1920 | A |
1355485 | Lleo et al. | Oct 1920 | A |
1370927 | Staude | Mar 1921 | A |
1411556 | Almen | Apr 1922 | A |
1520960 | Nagelmann | Dec 1924 | A |
1582076 | Page | Apr 1926 | A |
1637017 | Almen | Jul 1927 | A |
1679924 | Almen | Aug 1928 | A |
1696676 | Fuhr | Dec 1928 | A |
1698102 | Michell | Jan 1929 | A |
1732659 | Redrup | Oct 1929 | A |
1787493 | Redrup | Jan 1931 | A |
1808380 | Royal | Jun 1931 | A |
1814946 | McGeorge | Jul 1931 | A |
1819137 | Thompson | Aug 1931 | A |
1825691 | Hall | Oct 1931 | A |
1844386 | Harris et al. | Feb 1932 | A |
1869440 | Schlenker | Aug 1932 | A |
1891927 | Hall | Oct 1932 | A |
1895206 | Ricardo | Jan 1933 | A |
1948827 | Redrup | Feb 1934 | A |
1968470 | Szombathy | Jul 1934 | A |
1978194 | Gray | Oct 1934 | A |
2009495 | Hulsebos | Jul 1935 | A |
2028557 | Nevatt | Jan 1936 | A |
2042730 | Redrup | Jun 1936 | A |
2065790 | Braunwalder | Dec 1936 | A |
2083730 | Michell | Jun 1937 | A |
2097138 | Steele | Oct 1937 | A |
2105019 | Turner | Jan 1938 | A |
2150162 | Hall | Mar 1939 | A |
2152351 | Hall | Mar 1939 | A |
2152811 | Michell | Apr 1939 | A |
2216342 | Hall | Oct 1940 | A |
2216343 | Hall | Oct 1940 | A |
2222294 | Hall | Nov 1940 | A |
2251543 | Hulsebos | Aug 1941 | A |
2257258 | Hulsebos | Sep 1941 | A |
2258127 | Almen | Oct 1941 | A |
2258138 | Hall | Oct 1941 | A |
2278696 | George | Apr 1942 | A |
2282721 | Hall | May 1942 | A |
2282722 | Hall | May 1942 | A |
2341203 | Borer | Feb 1944 | A |
2379119 | Tucker | Jun 1945 | A |
2403282 | Holmes | Jul 1946 | A |
2424660 | Howard | Jul 1947 | A |
2451455 | Willson | Oct 1948 | A |
2464228 | Hall | Mar 1949 | A |
2475295 | Sherman | Jul 1949 | A |
2583564 | Hall | Jan 1952 | A |
2650676 | Jamotte | Sep 1953 | A |
2737055 | Dauben | Mar 1956 | A |
2827792 | Hopkins | Mar 1958 | A |
2918012 | Lucien | Dec 1959 | A |
3007462 | Balzer | Nov 1961 | A |
3101621 | Bunyan | Aug 1963 | A |
3180159 | Girodin | Apr 1965 | A |
3182644 | Drtina | May 1965 | A |
3196698 | Liddington | Jul 1965 | A |
3212483 | Balzer | Oct 1965 | A |
3257855 | Dangauthier | Jun 1966 | A |
3276276 | Dangauthier | Oct 1966 | A |
3319874 | Welsh | May 1967 | A |
3357209 | Mooney | Dec 1967 | A |
3398699 | Stark | Aug 1968 | A |
3528317 | Cummins | Sep 1970 | A |
3528394 | Cummins | Sep 1970 | A |
3910242 | Hom et al. | Oct 1975 | A |
3943895 | Howell | Mar 1976 | A |
3945359 | Asaga | Mar 1976 | A |
4066049 | Teodorescu et al. | Jan 1978 | A |
4077269 | Hodgkinson | Mar 1978 | A |
4152944 | Kemper | May 1979 | A |
4166398 | Girodin | Sep 1979 | A |
4207779 | Papst | Jun 1980 | A |
4209980 | Pronovost et al. | Jul 1980 | A |
4433596 | Scalzo | Feb 1984 | A |
4454779 | Vos | Jun 1984 | A |
4497284 | Schramm | Feb 1985 | A |
4502427 | Brille | Mar 1985 | A |
4515113 | DeLorean | May 1985 | A |
4516536 | Williams | May 1985 | A |
4523549 | Lacy | Jun 1985 | A |
4688439 | Cureton et al. | Aug 1987 | A |
4727761 | Scalzo | Mar 1988 | A |
4736715 | Larsen | Apr 1988 | A |
4745814 | Miller et al. | May 1988 | A |
4869212 | Sverdlin | Sep 1989 | A |
4905637 | Ott | Mar 1990 | A |
4986226 | Lacy | Jan 1991 | A |
5007385 | Kitaguchi | Apr 1991 | A |
5027755 | Henry, Jr. | Jul 1991 | A |
5027756 | Shaffer | Jul 1991 | A |
5083532 | Wiesen | Jan 1992 | A |
5094195 | Gonzalez | Mar 1992 | A |
5103778 | Usich, Jr. | Apr 1992 | A |
5113809 | Ellenburg | May 1992 | A |
5205718 | Fujisawa et al. | Apr 1993 | A |
5269193 | Rabinow | Dec 1993 | A |
5273012 | Brock | Dec 1993 | A |
5368449 | Kimura et al. | Nov 1994 | A |
5415077 | Ono | May 1995 | A |
5437251 | Anglim et al. | Aug 1995 | A |
5442971 | Romanchev et al. | Aug 1995 | A |
5450823 | Istomin | Sep 1995 | A |
5553582 | Speas | Sep 1996 | A |
5564372 | Llewellyn | Oct 1996 | A |
5638778 | James | Jun 1997 | A |
5749337 | Palatov | May 1998 | A |
5752413 | Kuhn et al. | May 1998 | A |
5762039 | Gonzalez | Jun 1998 | A |
5782219 | Frey et al. | Jul 1998 | A |
5904044 | White | May 1999 | A |
5950580 | Birckbichler | Sep 1999 | A |
5992357 | Tasi | Nov 1999 | A |
6003480 | Quayle et al. | Dec 1999 | A |
6098578 | Schuko | Aug 2000 | A |
6164252 | Kuhn et al. | Dec 2000 | A |
6202606 | Anttila | Mar 2001 | B1 |
6305334 | Schuko | Oct 2001 | B1 |
6305335 | O'Toole | Oct 2001 | B1 |
6390052 | McMaster et al. | May 2002 | B1 |
6397794 | Sanderson et al. | Jun 2002 | B1 |
6487858 | Cammack | Dec 2002 | B2 |
20030046932 | Isaac, Jr. et al. | Mar 2003 | A1 |
Number | Date | Country | |
---|---|---|---|
20050155488 A1 | Jul 2005 | US |