Patent Application
20100319652
The present invention relates to rotary engines, and more particularly, to rotor housing assemblies for rotary engines.
Rotary engines, also known as Wankel engines, are used in a large number of applications, from automobiles, aircraft and boats to power generation and power tools. In one type of rotary engine, referring to
The fuel/air mixture first enters the rotor housing assembly 110 at a front side internal passage inlet 122 and travels through a front side internal passage 120 to a front side internal passage outlet 124 near the rotor 134. (A small portion of the fuel/air mixture passes through idling openings 180 in the barrel valve 118 to enter a barrel valve housing 142, and pass from thence to the internal chamber 140 through an internal chamber fuel/air inlet passage 146.)
After passing through and around various power train components, the fuel/air mixture, excepting the small portion, enters a rear side internal passage 156 through a rear side internal passage inlet 158 and exits through a rear side internal passage outlet 160. The fuel/air mixture enters the barrel valve housing 142, through an open end of the barrel valve 118: The fuel/air mixture passes through a fuel/air outlet opening 184 of the barrel valve 118 and into the internal chamber 140 through the internal chamber fuel/air inlet passage 146. Once in the internal chamber 140, the fuel/air mixture travels with the rotor 134, cooling and lubricating the rotor 134 and apex seals, before being combusted and exhausted as known in the art.
Thus, in this type of rotary engine housing assembly, one mechanism (the barrel valve) regulates entry of the fuel/air mixture into the internal chamber. To regulate entry of the fuel/air mixture into the housing assembly, a separate mechanism (not shown) must be provided.
Based on the foregoing, it is an object of the present invention to provide an improved rotary engine rotor housing assembly, as well as an improved method for regulating fuel/air flow through a rotary engine housing assembly.
According to an embodiment of the present invention, a rotary engine rotor housing assembly includes a rotor housing at least partially defining an internal chamber therein, a front side housing arranged on a front side of the rotor housing, a rear side housing arranged on a rear side of the rotor housing, and a barrel valve arranged in a barrel valve housing defined in the housing assembly. An internal lubrication flow path is defined within the housing assembly and the barrel valve is operable to regulate entrance of fuel/air flow both into the housing assembly and from the internal lubrication flow path into the internal chamber.
According to an aspect of the present invention, the barrel valve includes a valve element defining an interior volume, a fuel/air inlet opening and a fuel/air outlet opening being defined in the valve member in communication with the interior volume. The barrel valve also includes a separation plate dividing the interior volume into an inlet chamber, directly communicating with the fuel/air inlet opening, and an outlet chamber, directly communicating with the fuel/air outlet opening.
According to a method aspect of the present invention, a method of regulating fuel/air mixture flow in a rotary engine rotor housing assembly includes arranging a single valve in the path of a fuel/air mixture both from outside the housing assembly into an internal lubrication flow path, and from the internal lubrication flow path into an internal chamber. The single valve is operated to simultaneously regulate the fuel/air flow into the housing assembly and into the internal chamber.
These and other objects, aspects and advantages of the present invention will be better understood in view of the drawings and following detailed description of a preferred embodiment.
With reference to
Referring to
Referring to
An exhaust passage 50 and spark plug passage 52 are also defined extending from the internal chamber 40 to outside the rotor housing 14. The spark plug passage 52 is dimensioned to sealingly accommodate a spark plug (not shown) therein.
Referring to
The rear side housing 16 further defines a rear side housing central opening 62 proximate to the rear side internal passage inlet 58. The rear side housing central opening 62 accommodates rear bearings (not shown) for the rotary engine drive shaft 30. The rear side housing 16 has a rear machined surface 64 that sealingly engages a rear surface of the rotor 34 (
Referring to
A fuel/air inlet opening 82 is defined through the valve member 68 opening into the inlet chamber 74 and is dimensioned to substantially match the shape of the adjacent end of the rotor housing assembly fuel/air inlet passage 44. A fuel/air outlet opening 84 is defined through the valve member 68 opening into the outlet chamber 76 and is dimensioned to substantially match the shape of the adjacent end of the internal chamber fuel/air inlet passage 46.
The valve stem 78 has a distal end 88 adapted for engagement by an operating mechanism (not shown) adapted to rotate the barrel valve 18 between an idle and a full power position.
It will be appreciated that the rotary engine rotor housing assembly 10 can incorporate additional features beyond those described above, such as bolts, threaded bores, additional bearings, gaskets, seals, cooling channels, mounting points, and other components known in the rotary engine art. Various construction materials can also be used. Preferably, the front side housing 12, rotor housing 14 and rear side housing 16 and barrel valve 18 are made from aluminum, and the rotor 34 from steel with high wear rotor surfaces being formed from ceramics. However, other materials can be used as desired or dictated by design requirements.
In addition to being applied to the design and manufacture of new rotary engine housing assemblies, the aspects of the present invention can be applied to retrofits of existing rotary engine housing assemblies. For example, referring to
In operation, with reference to
At idle, the barrel valve 18 is rotated such that the valve member 68 almost completely occludes the adjacent ends of the rotor housing fuel/air inlet passage 44 and the internal chamber fuel/air inlet passage 46, with only a minimal portion of the fuel/air inlet and outlet openings 82, 84 exposed. The fuel/air mixture enters the inlet chamber 74 and substantially all of the relatively small amount of fuel/air mixture flows through the idling openings 80 directly to the outlet chamber 76. From the outlet chamber 76, the fuel/air mixture enters the internal chamber 40 through the internal chamber fuel/air inlet passage 46. In the internal chamber, the fuel/air mixture is combusted and exhausted in a manner known in the art.
Above idle, the barrel valve 18 is rotated such that a larger portion of the fuel/air inlet and outlet openings 82, 84 are aligned with the respective adjacent ends of the rotor housing fuel/air inlet passage 44 and the internal chamber fuel/air inlet passage 46. The pressure drop across the internal chamber 40 is sufficient that a significant portion of the fuel/air mixture flows from the inlet chamber 74, out the corresponding open end of the valve member 68 and into the front side internal passage inlet 22.
The fuel/air mixture flows from thence through the front side internal passage 20 and out the front side internal passage outlet 24. The fuel/air mixture helps to lubricate the various drive train components as it passes between the rotor 34 and drive shaft 30 towards the rear side housing 16.
The fuel air/mixture enters the rear side internal passage 56 through the rear side internal passage inlet 58 and exits through the rear side internal passage outlet 60. The fuel/air mixture again enters the barrel valve housing 42, this time into the outlet chamber 76 through its respective open end of the valve member 68.
The fuel/air mixture passes through the fuel/air outlet opening 84 and into the internal chamber fuel/air inlet passage 46. Once in the internal chamber, the fuel/air mixture is combusted and exhausted in a manner known in the art.
It will be appreciated that a rotor housing assembly according to the present invention can regulate the entrance of the fuel/air mixture into the housing assembly and from thence into the internal chamber with a single valve. Accordingly, the need for a separate mechanism to regulate entrance of the fuel/air mixture into the housing assembly is eliminated, along with the concomitant mechanical complexity and weight. Thus, the rotary engine power-to-weight ratio can be increased.
While a rotor housing assembly according to the present invention can be used in substantially any rotary engine application, such as automobiles, watercraft and aircraft, it will be appreciated that the present invention is particularly advantageous in applications where low weight, high power-to-weight ratio and/or mechanical simplicity are most valuable. For example, the present invention offers significant advantages in personal watercraft and small aircraft applications.
In general, the foregoing description is provided for exemplary and illustrative purposes; the present invention is not necessarily limited thereto. Rather, those skilled in the art will appreciate that additional modifications, as well as adaptations for particular circumstances, will fall within the scope of the invention as herein shown and described and the claims appended hereto.
