Abstract:
The device includes a set of rotatable vanes and a set of stationary vanes which are mounted within a cylindrical housing. The set of rotatable vanes are connected to a post located at the axis of the housing and rotate relative to the post in response to the intake or exhaust fluid impinging on the vanes which are angled relative to the direction of flow of the fluid stream. The set of stationary vanes are rigidly secured to the post and also rigidly secured to the housing walls. The set of stationary vanes are positioned adjacent the set of rotatable vanes and are similarly angled relative to the direction of flow of the fluid stream in order to deflect the fluid stream and impart a swirling motion to the fluid stream in order to provide more complete mixing of the air/fuel mixture of the intake fluid stream or scavenging of the exhaust fluid stream. Tabs which extend radially outwardly from the housing ends secure the device within an intake or exhaust passageway.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a continuation in part of patent application Ser. No. 11/042,101 filed Jan. 26, 2005 entitled Fluid Swirling Device and now copending. 

   BACKGROUND OF THE INVENTION 
   The invention relates generally to fuel economizers and performance enhancers for internal combustion engines of the type conventionally used in motor vehicles. More specifically, the invention relates to devices which improve the fuel economy and performance of such internal combustion engines via modification of the intake and exhaust systems thereof. The invention also more specifically relates to intake and exhaust system components, parts and fittings which provide enhanced combustion efficiency by more thoroughly mixing the air and fuel entering the engine or by improving exhaust gas flow through the exhaust system. 
   With the continually increasing worldwide proliferation of motor vehicles, worldwide concern for the reduction of toxic gases emitted from the internal combustion engines of such vehicles has concomitantly increased. As a result, manufacturers of motor vehicles have sought to directly treat the toxic exhaust gases by means of exhaust gas recirculation or catalytic degradation. Such efforts have been generally successful in reducing the toxic gases emitted from the internal combustion engines. However, such additional treatment is expensive, is not long lasting so that it requires component replacement at certain intervals and requires maintenance. In addition, such modifications of motor vehicle exhaust systems increases the weight of the vehicles and may compromise performance. 
   Some motor vehicle manufacturers have therefore sought to reduce toxic exhaust gas emissions by modification of the intake systems of the internal combustion engines thereof. However, intake systems of internal combustion engines have particular complexities which make addressing these concerns via modification of the intake systems very difficult. 
   In a conventional internal combustion engine&#39;s intake system, the fluid flow which moves adjacent the walls of the intake passageway i.e., laminar fluid flow, typically includes a substantial amount of gasoline that is not atomized. Fuel that is not atomized does not readily combust. Thus, incomplete atomization of the fuel in the fluid flow hinders complete combustion of the fluid. This laminar flow consequently reduces the combustion efficiency of the engine. In addition, due to the frictional forces generated by contact of the fluid flow against the walls of the intake passageway, the laminar fluid flow travels through the passageway at a slower velocity than the rest of the fluid flow. Moreover, due to the difference in mass density between the gasoline molecules and the air molecules in the laminar fluid flow, the gasoline molecules experience greater frictional forces via contact with the walls of the passageway than the air molecules resulting in slower moving gasoline molecules than air molecules. This difference in velocity tends to additionally hamper mixing of the gasoline particles with the air particles thereby further contributing to incomplete combustion of the fluid and reducing the efficiency of the engine in converting heat energy to mechanical energy. 
   Inducing turbulence in the fluid flow passing through the intake passageway reduces laminar fluid flow and moves the slower moving gasoline particles away from the walls of the passageway thereby preventing further deceleration caused by contact with the walls. Both of these effects result in improved mixing of the air and fuel. Such benefits can be realized if turbulence is induced either in the air entering the carburetor (or fuel injection system), in the fluid passing through the intake manifold or intake runners or in the fluid passing through the intake ports or around the intake valves of the engine. Consequently, various devices and systems have been designed to induce such turbulence at various locations in the intake system. 
   Some prior art devices which are designed to produce turbulence in the air entering the fuel introduction subsystem include vanes which deflect the air passing thereagainst in order to impart a swirling motion to the air. Some such devices include a hub or central member to which the device vanes are attached. The central member provides rigidity to the vanes so that they do not absorb energy of deflection but rather transmit that energy back to the fluid. The central member is typically streamlined in order to reduce obstruction of fluid flow and reduce negative pressure areas which would otherwise create undesired turbulence. 
   Others of such prior art devices which induce turbulence through the use of vanes do not utilize a central member in order to eliminate the likelihood that such members would present a significant obstruction to air flow. Some of these devices utilize vanes which are radially curved to attach both ends of the vanes to the same side of the cylindrical housing. However, the vane portions which are at the central area produce higher stresses at the attachment points due to the effects of leverage. In addition, the absence of a secure central connection and thereby lack of rigidity of the vanes at the central area results in deflection movement in response to the forces of the fluid flow. The movement of the vanes may adversely affect the fluid flow movement by setting up harmonics in the fluid, by absorbing energy from the fluid flow or by undesired deflection of the fluid flow. The vanes are often made thicker in an attempt to obviate these shortcomings. However, the thicker vanes reduce the cross-sectional area of the passageway thereby tending to reduce fluid flow through the passageway. 
   Many of the prior art devices that induce air turbulence are manufactured in various sizes to accommodate the differently sized and structured intake systems of the many makes and models of motor vehicles on the market. Some of these prior art devices are simply dimensioned to adequately fit in the duct in which placed while others are designed to be diametrically resilient to exert a force against the inner walls of the intake duct and thereby provide a more snug fit therein. This prevents displacement of the device within the duct and also allows it to accommodate small variations in the diametrical sizes of these ducts. However, due to the oftentimes high vibrations acting on the device while in use and during vehicle operation, this snug fit is often not enough to prevent displacement of the device. Displacement of the device from its intended position can result in damage to the device, the duct or other parts of the intake system or engine. As a result of these problems many of these devices are instead designed to fit in other parts of the intake system in which component structures thereof are available to secure the device therein. 
   One of the primary disadvantages of prior art devices or systems that generate intake air turbulence is that the structures thereof that produce the desired turbulence also restrict air flow through the system. This undesirably reduces the maximum quantity of air and fuel that is delivered into the engine thereby reducing its maximum horsepower output. The deflection of air flowing through the intake system so as to produce turbulence may absorb excessive kinetic energy of the moving air thereby undesirably reducing the velocity of the air flow into the engine. In addressing these concerns, some designers have minimized the total surface area of the turbulence generating structures. Although such designs have been somewhat successful in reducing the otherwise excessive kinetic energy reduction of the air flow, they also reduce the amount of desired turbulence generated. Other designers have addressed these concerns by orienting the turbulence generating structures at relatively small angles relative to the incoming air flow. Such designs have successfully reduced the otherwise excessive kinetic energy reduction of the air flow, but they have similarly also reduced the amount of desired turbulence generated. 
   Some prior art devices seek to improve mixing of the air and fuel by inducing both turbulence and a swirling motion to the fluid stream. An example of a prior art device that generates swirling and also turbulence of the intake air is disclosed in U.S. Pat. No. 5,947,081 to Kim. The device disclosed includes vanes which have slits as well as concave and convex portions. The small concave and convex surface portions of the vanes deflect small portions of the air flow at relatively sharp angles of deflection. The high degree of deflection produces turbulence of the air stream. This turbulence includes collision of fluid flow molecules rather than a smooth blending or mixing of the fluid flow. Consequently, the collisions absorb energy thereby reducing the velocity of the fluid flow and consequently reducing fluid flow. In addition, the slit portions reduce the amount of metal in certain portions of the vanes thereby producing weakened portions which may break off under operational stress resulting in malfunction or damage to proximal engine components. 
   Another important disadvantage of some prior art devices is that they are difficult or expensive to mount in the engine system. Some prior art devices such as that disclosed in U.S. Pat. No. 4,424,777 to Klomp require that they be installed around the intake valves necessitating that the purchaser disassemble the engine and have engine components suitably machined to adapt these components to the device. But, this is typically a time consuming and expensive endeavor rendering such devices impractical for many motor vehicle owners. Similarly, other prior art devices require that they be installed in the intake manifold or runner necessitating that the purchaser disassemble major components of the engine in order to install such devices. But, this is also a time consuming and expensive endeavor requiring a degree of mechanical skill rendering such devices impractical for many motor vehicle owners. 
   Designers of such prior art intake fluid turbulence generation systems have recognized that the effectiveness of such turbulence varies according to the engine throttle position. U.S. Pat. No. 4,424,598 to Tsutsumi discloses an automobile swirl producing system which is responsive to engine load and engine operating conditions. Basically, the Tsutsumi system uses a pivot shaft responsive to carburetor throttle valve position to alter the swirl produced in the combustion chamber. However, the disadvantage of such a system is that it is difficult to properly install, and this especially discourages many do-it-yourselfers from purchasing it. 
   Designers of exhaust systems have also recognized that improving the rate of exhaust gas flow out of the engine can provide improved combustion efficiency. There have consequently been many exhaust systems that have sought to increase the velocity of exhaust gas flow out of the exhaust system and thereby in effect scavenge exhaust gases from the combustion chamber and exhaust ports. Some exhaust header systems have been designed to position exhaust pipes around the inner circumference of a collector pipe to produce swirling of the exhaust gases from the collector pipe in a vortex flow and thereby enhance exhaust gas flow therefrom. Such systems have been very effective in improving exhaust as well as intake fluid flow and thereby improving combustion. However, such systems require retuning of the carburetor or fuel injection system and ignition system of the engine as well as replacement of major engine system components and are thus impractical for many motor vehicle owners. In addition, such systems typically do not meet government emission standards requirements and are thus undesirable for the typical vehicle owner. 
   The many requirements for such air swirling or air turbulence generating devices and systems have resulted in prior art systems and devices in which there are compromises between swirl or turbulence generation and air flow restriction. In addition, there have also been many prior art systems that have been very effective in generating the required swirl or turbulence yet have necessitated undue engine component alterations and labor consumption. Consequently, what is needed is an intake and exhaust fluid swirling device which does not require special tools for installation and thus may be easily manually installed. What is also needed is an intake and exhaust fluid swirling device providing enhanced swirl generation while producing minimal fluid flow restriction. What is additionally needed is such a device which may be securely positioned in passageways of intake and exhaust systems. 
   SUMMARY OF THE INVENTION 
   It is a principal object of the present invention to provide an air swirling device that can be positioned in an intake passageway for air entering the fuel introduction subsystem of an internal combustion engine. 
   It is also another object of the present invention to provide an exhaust swirling device that can be positioned in an exhaust passageway for exhaust exiting an internal combustion engine. 
   It is another object of the present invention to provide an intake and exhaust fluid swirling device having structural components that are angled and shaped to provide enhanced swirling of the fluid flow. 
   It is another object of the present invention to provide an intake and exhaust fluid swirling devicing having vanes for inducing fluid swirling which spin in response to the forces of the intake and exhaust fluid stream acting thereon. 
   It is an object of the present invention to provide an intake and exhaust fluid swirling device which provides minimal obstruction to the fluid stream. 
   It is also an object of the present invention to provide an intake and exhaust fluid swirling device which produces fluid flow swirl the degree of which is proportional to the kinetic energy of the fluid stream entering the device. 
   It is an object of the present invention to provide an intake and exhaust fluid swirling device the degree of swirl produced varying according to engine operation parameters in order to normalize the degree of swirl produced. 
   It is also an object of the present invention to provide an intake and exhaust fluid swirling device which absorbs a portion of the fluid stream kinetic energy, the degree of that absorption inversely proportional to the kinetic energy of the fluid stream entering the device. 
   It is also an object of the present invention to provide a fluid swirling device having structural components which provide secure retention of the device within intake and exhaust passageways. 
   It is an object of the present invention to provide a fluid swirling device having structural components which are resilient to provide a snug fit in an intake or exhaust passageway. 
   It is an object of the present invention to provide a fluid swirling device that does not require disassembly of major engine components for installation thereof. 
   It is an object of the present invention to provide a fluid swirling device that may be manually installed in an intake or exhaust passageway. 
   It is an object of the present invention to provide an exhaust gas swirling device that reduces back pressure. 
   Essentially, the device of the present invention is designed to be positioned in the fluid flow path of an internal combustion engine and deflect the flow passing therethrough so as to induce a rotational or swirling type of movement of the fluid. This swirling movement tends to move the fluid away from the walls of the passageway and reduce continual or prolonged contact with the walls of the passageway which produce frictional forces exerting a drag on the fluid flow. When positioned in an intake passageway, the swirling motion enhances mixing of the air and fuel yielding more complete combustion of the fuel mixture. When positioned in a tailpipe or exhaust pipe, the swirling motion reduces the decrease in exhaust gas velocity that would otherwise occur yielding reduced backpressure and thereby increasing engine power output. 
   The device achieves its goal of modifying the straight motion of the intake air or exhaust gas flow so as to produce swirling motion of that flow by incorporating vanes which are positioned in the fluid flow stream. The vanes are angled so that they deflect the fluid laterally into a rotational movement. This lateral motion in combination with the longitudinal motion of the fluid stream ultimately results in a swirling or vortex type of motion of the fluid stream. 
   The device addresses a crucial disadvantage of prior art devices which is that they present deflection structures set at the same angle of deflection at both high and low engine speeds thereby resulting in a compromise of efficiency at both extremes of engine (and motor vehicle speed). In contrast, the free spinning characteristic of the present invention precludes a high degree of deflection at low engine speeds when the fluid stream velocity may not be high enough or the kinetic energy may not be high enough to accept a high degree of deflection as with prior art angled vanes without compromising optimum engine intake efficiency. Such a relatively high degree of deflection at low engine speeds would unduly reduce the velocity of the intake fluid entering the engine thereby reducing the mass or volume of intake fluids entering the combustion chamber. As a result, such prior art angled vanes may unduly reduce the power output and performance of the engine. Similarly, such a high degree of deflection of prior art angled vanes at low engine speeds would unduly reduce the velocity of the exhaust fluid exiting the engine thereby increasing backpressure to such an extent that the intake fluid is reduced. But, the alternative of providing a vane oriented at a small angle specifically for low engine speeds may render the vanes less efficient at high engine speeds when the air flow has high kinetic energy so that only minimal deflection results from striking the vanes. In contrast, the free spinning characteristic of the present invention allows the rotating vanes to be provided with a greater degree of angulature than conventional swirlers having stationary vane designs. At high air stream velocities, the relatively high kinetic energy of the air stream simply increases the degree of rotational motion of the vanes. At low air stream velocities, the relatively low kinetic energy of the fluid stream causes the vanes to rotate slowly and a proportionately greater amount of the kinetic energy may thereby be utilized to deflect the fluid stream. At high fluid stream velocities the relatively high kinetic energy of the stream causes the vanes to rotate faster yet present relatively low resistance to movement of the fluid stream through the device. The rotating characteristic of the vanes renders the vanes responsive to the high velocity of the fluid stream and its higher kinetic energy and may be able to surrender relatively larger amounts of this energy in order to produce the desired deflection and the desired swirl. Thus, the present invention via its unique free spinning feature provides deflection and kinetic energy absorption that is tailored to engine operational characteristics. This yields more efficient swirl generation. The vanes&#39; ability to spin allows them to be at a higher and more optimal angulature than would otherwise be possible because less kinetic energy is absorbed at all engine speeds and throughout the engine&#39;s parameters of operation in accordance with their ability to respond to the air flow velocity and kinetic energy. 
   When the kinetic energy is high due to either high engine speeds or high mass of fluid stream entering the device, the rotatable vanes spin at a relative high rate. But, reducing the engine speed, closing the throttle or reducing engine load does not result in immediate reduction of the rotational speed of the rotatable vanes. Thus, the kinetic energy of the vanes which is still high is transmitted to the fluid stream which was moving with less kinetic energy than before the transmittal. This has a normalizing effect on the fluid stream kinetic energy. 
   It is an important feature that the rotatable vane structure is positioned upstream of the stationary vanes. In this way the swirl motion is gradually introduced to the fluid stream thereby minimizing undesired turbulence and agitation. The stationary vanes thus meet a fluid stream which has already experienced a directional change in motion and is thus swirling to a certain degree. Due to inertia, this facilitates further generation of swirl of the stream by the stationary vanes. Consequently, more fluid stream swirl is generated than may be possible with prior art designs in which angled stationary vanes meet head on and deflect a fluid stream which is moving in a straight line longitudinally through the passageway. In contrast to less efficient prior art designs, the present invention produces swirl of the fluid stream with minimal reduction of the fluid stream&#39;s kinetic energy and with minimal reduction of the fluid stream&#39;s velocity. Furthermore, conventional prior art designs unduly absorb the fluid stream&#39;s kinetic energy and reduce the velocity of the fluid stream. Consequently, the device of the invention does not have the deleterious effect on intake and exhaust system efficiency of conventional prior art systems and devices. 
   In operation, the spinning vanes rotate into contact with the back side of the mass of fluid that is moving through the device of the invention. The rotating vanes will in effect push on the mass of fluid. Since the air and fuel combination is a fluid mixture, the fluid mass has a certain degree of cohesiveness and this will cause that portion of the fluid stream to in effect bend into the desired lateral direction which adds to the swirl motion. That portion of the fluid stream is thus made to change direction. Thus, the rotating vanes cause the deflection or change to a lateral direction by means of deflection by impinging on the vanes head on as well as by means of the vanes striking the fluid on the tail side. With regard to each particular mass of fluid stream in the form of a fluid sheet moving between the particular pairs of rotating vanes, that sheet is induced to change to lateral direction of motion at both sides of the fluid stream sheet. This produces a smoother transition from longitudinal direction of movement to lateral direction of movement. As a result, the swirl that is produced is smoother and with less undesired turbulence than without such rotating vane structure. 
   In operation, the rush of fluid stream impinging on the rotating vanes will deflect i.e., change its direction of movement or in effect push the vanes into moving laterally. The degree to which the fluid stream will either change its direction of movement or move the vanes laterally depends on which takes less kinetic energy from the fluid stream. Consequently, the degree of rotational motion of the vanes is proportional to the velocity of the fluid stream and the mass density of the fluid stream passing through the rotating vane structure. These factors depend upon engine speed, throttle position and engine load. Thus, the rotational speed of the rotating vane structure as well as the fluid stream&#39;s change in direction to lateral movement will vary in degree. Therefore, the rotating vane structure has a normalizing effect on the degree of swirl produced during typical engine operation. In contrast, with conventional stationary vanes, the angle of deflection is constant throughout the engine speed range, throttle and engine load. Consequently, with conventional stationary vanes, the deflection angle although perhaps sometimes optimum is other times less than optimum during typical engine operation. 
   The device includes a housing within which the vanes are mounted. The housing is open at both longitudinal ends for the fluid flow to pass through. The housing is sized and shaped to accommodate the intake ducts or passageways of various motor vehicles as well as the exhaust pipes or passageways of various motor vehicles. This makes it relatively easy for a user to simply manually insert the device into an intake duct or exhaust pipe. However, due to engine vibrations and vehicle jarring type motions, other prior art devices have become dislodged from their desired locations in such ducts. Therefore, in order to overcome such shortcomings of prior art devices, the present invention includes structures which engage the passageway in such ways as to enable it to be retained in its desired position therein. These structures include tabs at the lower end of the housing which project outwardly therefrom. The tabs are integral with the housing and resist inward deflection. Thus, when the housing is inserted in a duct (which is diametrically slightly larger than the housing), the resilient tabs engage the duct and exert a resistive force thereagainst. The resistive force prevents undesired movement of the device relative to the duct thus ensuring a tight fit or snug fit. In addition to the effect of the resistive force, the ends of the tabs which contact the inner surfaces of the duct are relatively small thereby providing a gripping surface. The gripping surface also prevents undesired movement of the device relative to the duct. 
   The retaining structures of the invention also include tabs at the upper end of the housing which similarly project outwardly therefrom. These tabs have outer ends which extend radially from the housing. The underside straight surfaces of the tabs engage the rim of the duct in which the housing is positioned and thereby act to block axial movement of the housing relative to the duct. Thus, the tab ends prevent the housing from undesirably moving deeper into the duct. Moreover, intake systems typically include a component structure that fits over the rim and enabling it to be used to cover the tab ends thus block axial movement of the housing relative to the duct. The blocking effect of that component structure prevents the housing from undesirably moving out of the duct. Thus, when the device is installed in the duct and the intake system is assembled, the tabs prevent movement of the housing relative to the duct in both axial directions. The upper and lower tabs thus enable the device to stay in its desired position within the passageway without the need for screws or other fastener means to anchor it in place. Obviating the need for fasteners results in no need to drill holes in the intake system or otherwise cause structural changes thereto which may weaken it or produce air leaks. Moreover, this feature of the present invention facilitates proper user installation thereof making the installation process fast, simple and easy. 
   The vanes are mounted within the housing and extend radially between the inner walls thereof and the central post (or axle). The vanes have appendages at the longitudinal ends thereof, and the housing has apertures which receive the appendages. The appendages extend through the apertures, and their ends are positioned flat against the outer surface of the housing and secured thereto in order to attach the vanes at the outer ends thereof to the housing. 
   The apertures are angled so that the vane portions located at the housing are comparably angled. The angulature of the vanes produces a rotational movement of the fluid flow upon impacting these vane portions. The end portions of vanes located at opposite sides of the housing are angled in opposite directions from each other. 
   The lower apertures are also angled relative to the upper apertures. The lower apertures are angled in the same axial direction but to a greater degree than the upper apertures. This results in the vane being angled upwardly more at its trailing edge than at its leading edge. The upper and lower portions of the vane at their peripheral portions thus have different angles of inclination so that the fluid stream is deflected first at the upper portion and subsequently deflected again in the same direction at the lower portion to produce a higher degree of deflection. Providing the vane portions with axially increasing angular orientation results in a smoother deflection of the fluid flow. This takes less kinetic energy from the impacting fluid flow than would otherwise result. Consequently, there is minimal reduction in fluid flow velocity. However, the upper and lower portions of the vanes at their central portions (at the central post or axle) do not have different angles of inclination. Instead, the upper and lower portions of the vane at their central portion have the same degree of inclination. The vanes are secured to the central post of axis so that the medial portions of the vanes are at the same angle of inclination as the peripheral portions. Each vane in its entirety is thus angled at a particular angle of inclination. 
   In comparison to conventional prior art designs, the rotatable vanes present less obstruction to the fluid flow because they yield to the kinetic energy of the fluid flow passing therethrough. Moreover, after passing through the spinning vanes, the fluid stream is further deflected by the stationary vanes to increase the degree of desired swirl thereby enhancing the swirl producing effectiveness of the device of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view of an intake air flow subsystem which incorporates the device of the present invention and showing the carburetor and intake duct of the subsystem. 
       FIG. 2A  is a sectional view of an exhaust gas flow subsystem which incorporates the device of the present invention and showing the catalytic converter and tailpipe of the subsystem. 
       FIG. 2B  is a sectional view of an exhaust gas flow subsystem which incorporates the device of the present invention and showing the exhaust manifold and exhaust pipe of the subsystem. 
       FIG. 3  is a perspective view of the device of the present invention. 
       FIG. 4  is an exploded view of the device of the present invention. 
       FIG. 5  is a top view of the device of the present invention. 
       FIG. 6  is a side view of the device of the present invention showing the apertures thereof. 
       FIG. 7  is a longitudinal-sectional view of the device of the present invention taken along lines  7 — 7  of  FIG. 6 . 
       FIG. 8A  is a front plan view of a representative vane of the rotatable vane component structure of the present invention. 
       FIG. 8B  is a top view of a representative vane of the rotatable vane component structure of the present invention as installed in the housing. 
       FIG. 8C  is a side end view of a representative vane of the rotatable vane component structure of the invention as installed in the housing. 
       FIG. 9A  is a front plan view of a representative vane of the stationary vane component structure of the present invention. 
       FIG. 9B  is a top view of a representative vane of the stationary vane component structure of the present invention as installed in the housing. 
       FIG. 9C  is a side end view of a representative vane of the stationary vane component structure of the invention as installed in the housing. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the drawings, the swirling device of the present invention is generally designated by the numeral  10 . The device  10  is sized to fit inside an intake passageway or duct  12  of an intake subsystem  14  of an internal combustion engine (not shown). The passageway  12  leads to a fuel introduction subsystem  16  which may be a fuel injection subsystem, as shown, or a carburetor. The passageway is thus used for delivery of intake air to the fuel injection subsystem  16  from the air filter box  15 . 
     FIG. 2A  shows the device  10  mounted in an exhaust passageway or pipe  19 . The tailpipe  19  is attached to a catalytic converter  21  which receives the exhaust gases from the muffler (not shown) and from the engine (not shown). The device provides a swirl to the exhaust gases resulting in a vortex shaped flow stream thereby drawing out the exhaust gases from the exhaust system. 
     FIG. 2B  shows the device  10  mounted in another type of exhaust passageway or pipe  18 . The exhaust pipe  18  is attached to an exhaust manifold  20  which receives the exhaust gases from the exhaust port (not shown) and combustion chamber (not shown) of the engine. 
   The device  10  is preferably manufactured in different sizes to accommodate the differently sized intake ducts and passageways of various makes and models of motor vehicles. The device includes a housing  22  which is preferably cylindrical in shape (having an axis  23 ) to accommodate standard intake ducts which are similarly cylindrical in shape. However, other types of housing shapes may also be used to accommodate intake ducts or exhaust ducts having other shapes. The housing  22  is open at both ends yet circumferentially closed and dimensioned so that it may be fitted within the ducts  12 ,  18  and  99  and positioned in the path of the intake gases and exhaust gases therein to allow these gases to pass therethrough. 
   The device  10  preferably includes an upper member  24  and a lower member  26 . Both the upper member and the lower member are mounted within the housing  22  and positioned adjacent each other. The upper member is positioned so that it is upstream of the fluid stream  28  so that it initially meets the gas flow of the fluid stream  28 . 
   The upper member  24  includes a set of vanes  30 . The set of vanes  30  are movably mounted onto an axle  34  so that the set of vanes are able to rotate relative to the axle  34 . The set of vanes  30  are mounted on the axle  34  via a bearing  36  in order to reduce the frictional forces generated by movement of the set of vanes  30 . Alternatively, a bushing (not shown) may be used instead of the bearing  36  in order to provide longevity and durability. Since the tip  38  of the axle  34  faces the fluid stream  28 , it is curved to reduce aerodynamic resistance. Preferably, the tip  38  is more curved at its front end portion than more rearward portions such that it is parabolic in longitudinal section. 
   The lower member  26  is dissimilar from the upper member  24  in that the lower member has a set of vanes which are stationary relative to the axle or central post  34 . Thus, the set of vanes  32  are securely connected to the central post  34  at their inner lateral ends  40  by welding for example. Alternatively, the set of vanes  32  may be instead integral, with the central post  34 . In addition, the set of vanes  32  are securely connected to the housing  22 . Thus, the set of vanes  32  securely interconnect the housing  22  and central post  34 . This interconnection provides a degree of structural strength and rigidity to the entire device  10 . The preferred means of interconnection of the set of vanes  32  to the housing  22  is via a set of upper and lower appendages  42  at the outer lateral ends  44  of the set of vanes  32  which are received by a set of upper and lower apertures  46  in the upper wall portions  48  and lower wall portions  50  respectively of the housing  22 . 
   The apertures  46  are preferably located at diametrically opposite sides of the housing  22 . The apertures  46  may be semi-circular (as shown) or rectangular and dimensioned to provide a snug fit between the apertures  46  and the appendages  42 . The apertures  46  are partly defined by aperture wall portions  52  which are preferably straight to engage the corresponding appendages  42  which are similarly straight (or flat). The apertures  46  and, more specifically, the wall portions  48  and  50  are angled such that they are inclined relative to the axis  23 . The angle of inclination of the apertures  46  and the upper wall portions  48  are preferably six degrees with reference to the axis  23 . The angle of inclination of the apertures  46  and the lower wall portions  50  are preferably also six degrees with reference to the axis  23 . Since the apertures  46  and appendages  42  and their corresponding vanes  32  snugly interfit, the angle of inclination of the apertures  46  translates to the same angle of inclination of the vanes  32  at portions adjacent to the apertures  46 . Away from the apertures  46  (and the housing  22 ) at the medial portions  54  of the vanes  32 , the medial portions  54  are also at the same angle of inclination as the portions  48  and  50 . The vanes  32  thus have the same angle of inclination throughout their entire lateral width from the central post  34  to the housing  22 . 
   Unlike the stationary vanes  32 , the set of rotating vanes  30  are not connected to the housing. Thus, the vanes  30  are able to rotate relative to the housing  22  as well as relative to the axle (or central post)  34 . The vanes  32  are securely connected to a collar  56  which is cylindrical and laterally encircles the axle  34 . The vanes  32  have medial portions  58  which are connected to the collar  56  at connection points  60  which are at an angle of inclination of six degrees with respect to the axis  23 . Since the vanes  30  are preferably rigid, the vanes  30  extend outwardly from the axle  34  at the same angle of inclination throughout their entire lateral width. The collar  56  is rotatably mounted on the axle  34 . The bearing  36  is preferably mounted within the collar  56  and positioned between the collar  56  and the axle  34 . The vanes are preferably integral with the collar  56 . Alternatively, however, the vanes  30  may also be welded to the collar  56 . 
   The set of vanes  30  preferably include six individual vanes  62 , while the set of vanes  32  preferably include four individual vanes  64 . The vanes  62  and  64  are preferably planar and generally rectangular in shape, as shown in  FIG. 8 . The vanes  64  extend radially across the width of the housing  22  from one side of the housing to the central post  34 . The vanes  64  are thus stationary relative to the housing  22  and the central post  34 . The vanes  62  extend radially across the width of the housing from the axle  34  and collar  56  to the housing  22 . But, they do not contact the housing  22 . Vanes  62  instead have lateral end portions  66  which are instead proximal to and adjacent the housing  22 . This enables the vanes  62  to rotate relative to the housing  22 . 
   The leading edges  68  of vanes  62  extend in a straight line radially across the housing  22  from the central post  34  to the housing  22 . Similarly the leading edges  70  of vanes  64  extend in a straight line radially across the housing  22  from the axle (or central post)  34  to the housing  22 . 
   The apertures  46  (and the straight aperture wall portions  52 ) and connection points  60  are preferably inclined at opposite directions at opposite sides of the housing  22 . The apertures  46  (and wall portions  52 ) are thus inclined in a clockwise direction with respect to the housing  22 . Concomitantly, the connection points  60  are thus inclined in a clockwise direction with respect to the housing  22 . Thus, the vanes  62  and the vanes  64  are oriented at an angle which is laterally clockwise from a vantage point of the fluid stream  28  entering the housing  22 . 
   The housing  22  is also provided with upper curved tabs  72  and upper straight tabs  74  at the upper end wall portions (or longitudinally upper end portions)  76  of the housing  22  and lower straight tabs  78  and lower curved tabs  80  at the lower end wall portions (or longitudinally lower end portions)  82  of the housing  22 . The tabs  72 ,  74 ,  78  and  80  extend radially outwardly from the wall portions  76  and  80  of the housing  22 . The upper straight tabs  74  preferably include upper main portions  84  and upper peripheral portions  86  oriented so that the upper peripheral portions  86  extend outwardly from the housing  22  and perpendicular to the housing  22 . The upper main portions  84  are inclined at an obtuse angle relative to the upper wall portions  76  and extend away from the lower wall portions  82 . The upper main portions  84  are flat and the upper peripheral portions  86  are also flat and inclined relative to the upper main portions  84 . When suitably positioned in the intake duct  12 , the upper peripheral portions  86  engage the rim  88  of the duct thereby preventing movement of the device  10  against the rim  88  in a longitudinal direction relative to the duct preventing the device from moving deeper into the duct than desired. The lower tabs  78  similarly have lower main portions  90  and lower peripheral portions  92  oriented so that the lower peripheral portions  92  extend outwardly from the housing  22  and perpendicular to the housing  22 . The lower main portions  90  are inclined at an obtuse angle relative to the lower wall portions  82  and extend away from the upper wall portions  76 . The lower main portions  90  are similarly flat and the lower peripheral portions  92  are also flat and inclined relative to the lower main portion  88 . When suitably positioned in the intake duct  12 , the lower peripheral portions  92  engage the inner surfaces  94  of the duct  12 . The upper curved tabs  72  preferably include upper main portions  95  and upper peripheral portions  96  so that the upper peripheral portions  96  are parallel to the upper wall portions  76  and extend toward the lower wall portions  82 . The upper main portions  95  are inclined at an obtuse angle relative to the walls  76  and extend away from the lower wall portions  82 . The upper main portions  95  are curved and the upper peripheral portions  96  are also curved and inclined relative to the upper main portions  95 . When suitably positioned in the intake duct  12 , the upper peripheral portions  96  engage the rim  88  of the duct thereby preventing movement of the device  10  against the rim in a longitudinal direction relative to the duct preventing the device from moving deeper into the duct than desired. The lower curved tabs  80  similarly have lower main portions  97  and lower peripheral portions  98  so that the lower peripheral portions  98  are parallel to the lower wall portions  82  and extend toward the upper wall portions  76 . The lower main portions  97  are similarly curved and the lower peripheral portions  98  are also curved and inclined relative to the lower main portion  97 . The lower main portions  97  are inclined at an acute angle relative to the lower wall portions  82  and extend away from the upper walls  76 . The curved tabs  72  and  80  are preferably a hyberbolic shape in cross-section. When suitably positioned in the intake duct  12 , the lower peripheral portions  98  engage the inner surfaces  94  of the duct. The relatively small end portion  99  of the lower peripheral portion  98  tends to produce a gripping effect effectively holding the device in the desired position within the duct  12 . The tabs  72 ,  74 ,  78  and  80  are composed of spring steel or other suitable substance which has memory such that it resists movement from its position in which extending outwardly from the upper and lower wall portions  76  and  82 . Thus, when the diametrical dimensions of the housing  22  relative to the duct  12  produce a narrow gap therebetween and therefor therefore result in inward deflection of the tabs  78  and  80  when the device is installed in the duct  12 , the resistive force of the tabs  78  and  80  serve to resist movement of the device  10  relative to the duct  12 . This tends to retain the device  10  within the duct  12 . The upper main portions  84  and  95  and upper peripheral portions  86  and  96  as well as the lower main portions  90  and  97  and lower peripheral portions  92  and  98  are planar but may be other suitable shapes rather than curved or flat. 
   The device  10  is used in an intake duct  12  to provide swirl to the fluid flow exiting the device but may also be used in an intake manifold or runner to swirl the fluid flow which includes both air and fuel. However, when used in a tailpipe, exhaust pipe or other portion of the exhaust system, the device  10  also provides swirl of the fluid flow exiting the device but the ultimate purpose of this application is not to provide mixing of the fluid components but simply to improve exhaust gas flow. Basically, the device  10  functions to draw out exhaust gases from the exhaust system. The improved exhaust gas flow in effect scavenges the exhaust gases from the exhaust ports resulting in improved intake fluid flow through the engine providing increased power. 
   In operation, the set of vanes (or set of rotatable vanes)  30  work in conjunction with the set of vanes (or set of stationary vanes)  32  to accomplish the desired objective of swirling the intake or exhaust fluid flow  28  passing through the passageway  12 , passageway (tailpipe)  19  or passageway  18 . Initially, the intake or exhaust fluid stream  28  meets the set of rotatable vanes  30  which alter the direction of the fluid flow  28  from a generally straight and longitudinal direction to a more lateral direction. This is accomplished smoothly and gradually as a result of the ability of the vanes  62  to spin responsive to the force of the moving fluid stream  28 . After passing through the set of rotatable vanes  30 , the fluid stream  28  meets the set of stationary vanes  32 . Subsequently, the set of stationary vanes  32  deflects the fluid stream  28  laterally. Since the fluid stream  28  is moving in a lateral direction (to a degree) when it meets the set of stationary vanes  32 , it is more easily diverted to a more lateral direction of motion than would otherwise be produced by a more conventional prior art vane structure. As a result of the combination of rotatable vanes and stationary vanes, the device of the present invention facilitates generation of swirl of the fluid stream. Moreover, the generation of swirl by the device is accomplished with less absorption of energy of the fluid stream so that intake and exhaust system efficiency is not compromised as with conventional prior art systems and devices. 
   Accordingly, there has been provided, in accordance with the invention, a device for swirling the fluid flow passing through the passageway of an intake or exhaust system of an internal combustion engine that fully satisfies the objectives set forth above. It is to be understood that all terms used herein are descriptive rather than limiting. Although the invention has been described in conjunction with the specific embodiment set forth above, many alternative embodiments, modifications and variations will be apparent to those skilled in the art in light of the disclosure set forth herein. Accordingly, it is intended to include all such alternatives, embodiments, modifications and variations that fall within the spirit and scope of the invention set forth in the claims hereinbelow.