This invention relates to vane-type rotary apparatuses, such as engines, and, in particular, to vane-type rotary apparatuses with split vanes having two separate components contacting cam-like surfaces on each side of a stator. The invention also relates to vane-type rotary apparatuses having a rotatable annular housing within the stator between the stator and the rotor, the components of the vane assemblies slidably engaging the housing, the housing rotating with the rotor and the vane assemblies.
Many different types of rotary engines have been suggested in the past and have been covered by a large number of patents. Only a relatively small number of these have been thoroughly tested. Many rotary engines are appealing on paper, but practical difficulties arise when prototypes are constructed.
The best-known rotary engine is the Wankel engine which has been in volume production in Mazda automobiles. Even this engine has had considerable difficulties with proper sealing of the rotors, although such problems have been largely overcome. However the engine is not particularly efficient and high fuel consumption has been a characteristic of vehicles using this technology.
Another type of rotary engine is the axial vane type. This type of engine has a cylindrical rotor within a cylindrical chamber in a stator. A plurality of blade-like vanes extend slidably through the rotor, parallel to the axis of rotation. There are undulating cam surfaces on each side of the rotor. High portions of the cam surface on one side align with low portions of the cam surface on the other side such that the vanes are caused to reciprocate back and forth in the axial direction as the rotor rotates.
One such engine is found, for example, in U.S. Pat. No. 4,401,070 to James Lawrence McCann. This type of engine compresses gases forwardly of each vane in the direction of rotation as the rotor rotates. The compression occurs as the vane moves from a low cam surface, relatively distant from the rotor, to a high cam surface relatively close to the rotor. After the gases are compressed, they must be transferred to the rearward side of each vane prior to combustion so that the ignited gases will propel the rotor forwards.
The need for transferring the compressed gases is removed in a variation of this type of rotary engine such as found in Polish Patent Number 38112 to Czyewski. In this case the gases are compressed between adjacent vanes which are angularly spaced-apart much closer than in the McCann engine. The gases are compressed as each pair of adjacent vanes moves towards a high cam area. Expansion of the ignited gases is permitted, and the propulsion force created, as the vanes continue to move past the high cam area to a relatively low cam area after ignition.
This type of rotary engine offers many potential advantages including high-efficiency, simple construction and light weight. However, while the theoretical possibility of such an engine has been suggested in the past, many practical difficulties have inhibited development of such engines beyond the stage of a working prototype. For example, considerable time and effort have been expended trying to develop practical sealing systems between the vanes, the rotor and the stator of such an engine.
Prior art rotary engines of this type typically have the radially outer edges of the vanes in sliding contact with the cylindrical inner wall of the stator. It has been difficult to insure both proper sealing between the vanes and the stator and, at the same time, deal with potentially high wear between the vanes and the wall of the stator or the seals and the wall of stator.
Another problem has been the axially outer edges of the vanes which are in sliding contact with the surfaces of the cams. Again it has been difficult to insure proper sealing on both sides of the rotor and deal with wear which inevitably occurs between the edges of the vanes, or the seals, and the cam surfaces.
The third area where difficulties have occurred is in delivering intake gases, such as an air/fuel mixture, to the spaces defined between the vanes and between the cams and the rotor. Likewise difficulties have occurred in providing for proper passage of exhaust gases from the spaces. Such means needs to be both efficient in transferring gases as well as being reliable in operation and simple and economical in construction.
Accordingly, it is an object of the invention to provide an improved rotary apparatus which improves sealing and reduces wear between radially outer edges of the vanes and the stator.
It is also an object of the invention to provide an improved rotary apparatus which improves sealing and reduces wear between axially outer edges of the vanes and the cam surfaces.
It is a still further object of the invention to provide an improved rotary apparatus with an efficient intake means for conducting intake gases to spaces between the vanes and between the cam-like surfaces and the rotor and improved exhaust means for conducting exhaust gases away from the spaces.
In accordance with these objects, there is provided a rotary apparatus comprising a stationary stator having an internal cylindrical chamber and a rotor rotatably mounted in the chamber. There are cam-like annular surfaces on the stator to each side of the rotor. A plurality of vane assemblies are slidably mounted on the rotor. The vane assemblies each have two outer ends which slidably engage the cam-like annular surfaces, whereby gases between the vane assemblies are compressed and expand between the cam-like surfaces and the rotor as the rotor and vanes rotate relative to the stator. Each of the vane assemblies has two separate components. Each outer end is on one of the components. The apparatus has a conduit for conducting compressed gases between the two components of each of the vane assemblies and thereby biasing each of the components toward one of the cam-like annular surfaces.
According to another aspect of the invention, there is provided a rotary apparatus comprising a stationary stator having an internal cylindrical chamber and a rotor rotatably mounted in the chamber. There are cam-like annular surfaces on the stator to each side of the rotor. A plurality of vane assemblies are slidably mounted on the rotor. The vane assemblies each have two outer ends which slidably engage the cam-like annular surfaces, whereby gases between the vane assemblies are compressed and expand between the cam-like surfaces and the rotor as the rotor and vanes rotate relative to the stator. There is a rotatable housing within the stator between the stator and the rotor, the vane assemblies slidably engaging the housing. The housing rotates with the rotor and the vane assemblies. Preferably radially outer edges of the vane assemblies slidably engage the housing.
According to a further aspect of the invention, there is provided a rotary apparatus comprising a stationary stator having an internal cylindrical chamber and a rotor rotatably mounted in the chamber. There are cam-like annular surfaces on the stator to each side of the rotor. A plurality of vane assemblies are slidably mounted on the rotor. The vane assemblies each have two outer ends which slidably engage the cam-like annular surfaces, whereby gases between the vane assemblies are compressed and expand between the cam-like surfaces and the rotor as the rotor and vanes rotate relative to the stator. There is intake means for intaking gases to spaces between the vane assemblies and between the cam-like surfaces and the rotor and exhaust means for exhausting gases away from the spaces. Each of the intake and exhaust means includes a one-way valve. For example each one-way valve may be a reed valve.
a is an isometric view of one of the vane assemblies thereof;
Referring to the drawings and first to
A plurality of vane assemblies, shown generally at 44, are slidably mounted on the rotor such that the vane assemblies reciprocate from side to side with respect to the rotor, as the rotor rotates relative to the stator, as may be best appreciated by comparing the different positions of the vane assemblies in
Each cam surface has an undulating nature as may be appreciated from
With reference to
In prior art engines of this type, each vane assembly comprised a single vane with two axial ends, each of which slidingly engaged one of the cams. However in this embodiment of the invention each vane assembly includes two separate components 72 and 74 as shown in
Each vane component has a axially outer end 78, a axially inner end 80, an radially inner end 82 and an radially outer end 84 as seen for component 74 in
a show engine 84 which is generally similar to engine 30. Like parts have like numbers. Stator 32 includes an outer housing 86, shown best in
Rotor 36 is in two halves 94 and 96 as shown in
Each rotor half has two sets of twelve openings. Openings 102 are for providing intake gases to the spaces between the vanes and between the rotor and the cams. Openings 104 are for exhausting exhaust gases from spaces 106 where the mixture is ignited and expands to propel the rotor. There is a seal between the intake and exhausting regions of the rotor.
The rotor halves are mounted on drive shaft 38 shown in better detail in
A plurality of intake reed valves 112, twelve in the case of the embodiment of
There is also a set of exhaust reed valves 124, twelve in the case of the embodiment of
Rotary engines according to the invention also differ from the prior art in that a rotatable annular housing 130, shown in
Exhaust gases pass radially outwards from the housing 130 through openings 136 into a groove 138 extending about the housing.
Referring to
By comparison, with reference to
By making the sleeve integral with the rotor, leakage between the rotor and the stator and between the vane and the stator is eliminated. In the conventional engine configuration it is necessary to add seals between the rotor and the stator to control the amount of leakage in this area. The seals are difficult to make because of the high rubbing velocity in this area and because the outer diameter of the rotor is interrupted by vane slots.
The rotary device of
In summary, the invention improves over the prior art by attaching a sleeve or rotatable housing to the outer diameter of the rotor such that it functions as an integral part of the rotor, rotating with the rotor and sealing the interface between the sleeve and the rotor. Also, the invention improves over the prior art in this embodiment by attaching a rotatable inner housing to the rotor such that the inner housing rotates with the rotor and seals the interface between the inner housing and the rotor. The housing can be made as an integral part of the rotor.
The invention eliminates the rotating relative motion between the rotor and the stator and significantly reduces wear and friction. Leakage between the rotor and stator is eliminated to along with the need for seals in this area. Leakage between the inner portion of the stator and the face of the rotor is also eliminated along with the need for seals in this area.
The invention, as illustrated in the embodiment of
Referring to
In a conventional engine, and the version of
In summary, the version of
The sealing grooves eliminates gaps that can form between the vanes and the outer and inner housings by providing a face seal for the vane against the sides of the grooves. This improves sealing and reduces leakage. The grooves eliminate seals on the radially inner and outer edges of the vanes. The axial grooves support the vanes to reduces vane deflection caused by pressure differences from one side of the vane to the other. Like the previous embodiment, this embodiment is applicable to engines, compressors, pumps, expanders and other types of rotary devices.
In summary, this embodiment of the invention consists of splitting the vanes vertically into two parts so that the vane surface that contacts the cam always contacts on both cam surfaces. A one-piece vane can only contact on one cam at the time. Applying outlet pressure to the space between the two vane halves pressure loads the vanes against the cam surfaces. Installing spring type elements between the two vane halves loads them against the cam surfaces.
This embodiment allows the cams to continuously seal against the cam surfaces and thus eliminates the need for seals in this interface. By applying outlet pressure to the space between the two cam surfaces, the invention ensures that they are pressed against the cam surfaces regardless of the pressures in the working chambers of the rotary device. Referring to
Referring to
In summary, this aspect of the invention consists of a vane 260 in two pieces 262 and 264 that are loaded against the sloped or inclined part of the vane half such that the seal piece 270 or 272 can move radially inward and seal against the inner housing. This aspect of the invention is also applicable to either a stationary or rotating (sleeved) inner housing with or without vane sealing and support grooves.
The outlet pressure is applied to the space 281 between the two seal pieces to load them against the sloped parts of the vane and thus to the inner housing. The resilient spring 280 is inserted between the two seal pieces to provide pre-loaded such that each seal is loaded against the inner housing when outlet pressure is present.
Each seal piece closes the gap between the bottom or inward inside 285 and 287 of the vane seal pieces and the outer diameter of the inner housing (or the bottom of the sealing and support grooves). This improves sealing in this area and helps to eliminate leakage. The sloped interface allows seal to move axially and radially to compensate for wear of the outer housing (or sleeve), the vane, the seal piece and the inner housing. As any of these components wear the gap between the two seal pieces increases. This aspect of the invention is applicable to compressors or pumps as well as expanders.
Referring to
A second series of thin sheet metal valves, including valve 302, are placed on the outward side of a series of holes communicating with the working chambers. These holes are further illustrated in
The use of reed type inlet and outlet valves on a positive displacement compressor or pump is very common. However the unique feature here is that these valves have been placed in the rotor of a rotory engine of this type. This location permits the inlet flow to be brought through a hollow rotor and shaft and benefit by the centrifugal pumping action which is inherent in the design. The fluid enters on the center line of the rotor and flows radially outward to reach the valve port. The centrifugal pumping effect raises the pressure of the inlet fluid before it reaches the inlet valve. Similarly the outlet flow goes through the exhaust valve in the face of the rotor and flows into a hollow cavity in the outer portion of the rotor. It exhausts from this cavity through the outer diameter of the rotor. The movement of the fluid from a given diameter (outer port) to the periphery of the rotor (rotor diameter) generates a centrifugal pumping effect which raises the outlet pressure.
In summary, this aspect of the invention consists of reed type inlet valves located in the face of a rotor of a rotory device of this class. There are individual valves for each working chamber. For example, a rotory device with eight vanes would have sixteen valves, eight on each side.
Inlet reed valves are located on the face of the rotor such that the intake flow comes through a hollow shaft and flows outward radially to the valves such that the pressure at the valve is higher than the pressure in the shaft due to centrifugal pumping action.
The invention also includes the feature of having reed type exhaust valves located in the face of a rotor of rotary engine of this type with individual valves for each working chamber.
Exhaust reed valves are located on the face of the rotor such that the exhaust flow exit from the valve travels radially outward to an exit from the outer periphery of the rotor. The pressure at the exit on the periphery is higher than the pressure at the valve due to centrifugal pumping action.
Locating the inlet and exhaust valves on the face of the rotor, with inlet flow through the shaft and exhaust flow through the outer periphery of the rotor, increases the efficiency of the device by adding a centrifugal pumping effect to a conventional rotary engine of this type. This essentially puts three pumps in series: a centrifugal pomp on the inlet, the rotary engine pump itself and a centrifugal pump on the exhaust or outlet. The invention is applicable to compressors and pumps.
It will be understood by someone skilled in the art that many of the details described above are provided by way of example only and can be varied or omitted without departing from the scope of the invention which is to be interpreted with reference to the following claims.