Abstract:
A torque converter impeller has a hemispherical wall with a plurality of vanes attached thereto. An improvement comprises a deflector adjacent the ends of the vanes to deflect fluid during rotation of the impeller such that the fluid is directed to the turbine vanes of the torque converter without overshooting the turbine. The deflector is preferably mounted to the inside surface of the impeller wall and extends 360°.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 of a provisional application Ser. No. 61/367,200 filed Jul. 23, 2010, and which application is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to torque converters for use with vehicles utilizing automatic transmissions. More particularly, the invention relates to an improved impeller and method for directing oil from the impeller to the turbine in a torque converter. 
     BACKGROUND OF THE INVENTION 
     Torque converters have been known and used in combination with automatic transmissions of automobiles for quite some time. Generally, a torque converter consists of a housing, an impeller or pump, a turbine, a stator containing a one-way clutch, and a lock-up clutch. 
     The impeller is hemispherical with an outer wall having inner and outer surfaces, and a plurality of vanes radially mounted to the concave inner surface of the impeller wall. The turbine is rotatably mounted within a back wall, and also contains a plurality of vanes opposite the impeller vanes. The impeller wall is welded to the converter body to form an enclosed housing for the torque converter. The stator is located between the impeller and the turbine. The impeller has an input shaft operatively connected to the engine drive shaft. The turbine has an output shaft attached to the transmission input shaft so as to rotate the output shaft of the transmission. 
     Many improvements have been made to torque converters to improve operation and efficiency. For example, see Applicant&#39;s patent, U.S. Pat. No. 6,996,978, relating to an improved stator for the torque converter. Also, see the General Motors patent, U.S. Pat. No. 6,959,239, which discloses a cooling control for a torque converter; the Nissan patent, U.S. Pat. No. 7,264,574, which discloses a control device for the torque converter lock up; and the Daimlerchrysler published application, U.S. Publication No. 2008/0016859, which relates to augmented output method and apparatus for a torque converter. 
     In use, fluid, such as oil, is added into the torque converter housing. When the engine shaft rotates the impeller, the fluid starts rotating as well. As the rotation speeds up, centrifugal forces cause the fluid to flow outward toward the impeller vanes. The impeller vanes direct the fluid towards the turbine vanes, wherein the force of the fluid causes the turbine to rotate in the same direction as the impeller. The turbine shaft rotates the transmission shaft, which causes the vehicle to begin moving. The orientation of the turbine vanes directs the fluid towards the center of the turbine, where the vanes of the stator direct the fluid back towards the impeller, and the fluid cycle is repeated. Initially, the impeller will be rotating at a much greater speed than the turbine, which results in energy loss between input from the motor and output from the transmission. However, when the vehicle reaches a higher speed (over 40 miles per hour), the impeller and turbine will be rotating at approximately the same speed. At this time, a lock-up clutch will mechanically connect the impeller and the turbine so that they rotate at exactly the same speed to transfer 100% of the power through the torque converter. 
     The lock-up clutch is installed in front of the turbine. When engaged, the clutch will rotate with and lock together the rotational speeds of the impeller and the turbine. This is called the “lock-up operation.” Because 100% of the power from the engine is passing through the torque converter, the vehicle will obtain greater fuel efficiency. However, problems exist with current designs of torque converters, and more specifically, with the design of the impeller. Because the impeller and turbine rotate independent of one another and contain separate vanes, when the centrifugal force directs the fluid outwardly towards the turbine, the turbine vanes may not receive all of the fluid. The fluid may overshoot the turbine vanes, and end up in front of the lock-up clutch. This fluid leak into the lock-up clutch increases the amount of time before the torque converter is able to “lock-up,” or it may prevent lock-up all together. When the impeller and turbine are not locked together, heat is generated in the converter. The greater the load and RPM difference, the greater the heat generated. This heat is lost power, and results in a lower transmission life, performance and fuel economy. 
     Therefore, the present invention addresses an improvement in the art and provides a better method and means for the fluid to be directed from the impeller to the turbine in a torque converter for improved efficiency, reduced lock-up time, and enhanced fuel economy. 
     It is therefore a principal object, feature, and/or advantage of the present invention to provide an improved method and apparatus for increasing fuel efficiency in an automobile having an automatic transmission. 
     It is another object, feature, and/or advantage of the present invention to provide an improved method and apparatus for transferring a fluid from an impeller pump to a turbine in a torque converter. 
     It is another object, feature, and/or advantage of the present invention to provide an improved method and apparatus for decreasing the amount of time the torque converter will take to lock up. 
     It is another object, feature, and/or advantage of the present invention to provide an improved method and apparatus for increasing the life of a lock-up clutch. 
     It is another object, feature, and/or advantage of the present invention to provide an improved method and apparatus that is compatible with most automobiles having automatic transmissions. 
     Still another objective of the present invention is the provision of an improved torque converter impeller having a deflector for improved flow of fluid from the impeller to the turbine. 
     Yet another objective of the present invention is the provision of a deflector on a torque converter impeller to preclude fluid over-shoot of the turbine. 
     SUMMARY OF THE INVENTION 
     The improved torque converter of the present invention includes an impeller or pump, a turbine, and a stator between the impeller and the turbine. The impeller is operatively connected to the output shaft of the vehicle engine, while the turbine is operatively connected to the output shaft of the vehicle transmission. The improvement is a deflector, or series of deflectors, in the impeller, which direct the oil or fluid from the impeller to the turbine during operation of the torque converter and thereby eliminating or minimizing loss of functional fluid flow between the impeller and turbine so as to improve the efficiency of the torque converter and the engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an engine, a torque converter, and an automatic transmission of an automobile. 
         FIG. 2  is an exploded view of the torque converter. 
         FIG. 3  is an elevation view of the inside of a preferred embodiment of a torque converter impeller of the present invention. 
         FIG. 4  in an enlarged view taken along line  4 - 4  of  FIG. 3  and showing the impeller deflector adjacent the impeller vanes. 
         FIG. 5  is an elevation view of an impeller having an additional embodiment of a fluid deflector, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As seen in  FIG. 1 , the torque converter of the present invention is generally designated by the reference numeral  10 . The torque converter  10  is located between the vehicle engine  12  and the vehicle automatic transmission  14 . The transmission includes an output shaft  16  which operatively drives one or more vehicle wheels  18 . 
     The torque converter  10  includes an impeller  20 , a turbine  22 , and a stator  24 , as shown in  FIG. 2 . The impeller  20  has a hemi-spherical body or wall  26  to which a plurality of blades or vanes  28  are fixed. The turbine  22  is rotatably mounted in a body  30  and has a plurality of blades or vanes  32 . The impeller  20  has an input shaft  34  connected to the engine drive shaft by any convenient coupling means. The turbine  22  has an output shaft  36  connected to the transmission shaft  16  by any convenient coupling means. The torque converter  10  also includes a lock-up clutch  25 . 
     The above description of the torque converter  10  is conventional. 
       FIG. 3  shows a preferred embodiment of an impeller  20  of the present invention. The impeller vanes  28  are curved and extend radially about the center of the impeller. The impeller vanes  28  are spaced equally apart from one another, and are also oriented at substantially the same angle as one another. A ring  38  supports the vanes  28 . The ring  38  is spaced from the wall  26  of the impeller  20 . 
     The improvement to the impeller, according to the present invention, is the provision of a deflector  40  positioned on the impeller wall  26  adjacent the outer ends of the vanes  28 . The deflector  40  deflects a fluid, such as oil, into the turbine, as discussed in greater detail below. The deflector  40  may take many forms. In the embodiment of  FIGS. 3 and 4 , the deflector  40  is a weld bead adjacent the impeller vanes  28  and extending around the outer wall  26  of the impeller  20 . The weld bead  40  is a continuous weld extending 360° around the inner periphery of the impeller wall  26 . 
       FIG. 5  shows an alternative embodiment for the deflector  40 A in the form of a rod on the impeller wall  26  adjacent the outer ends of the vanes  28 . The rod  40 A may be attached by weld, by adhesive, or by other means which will fix the rod to the inside surface of the wall  26  of the impeller  20 . The rod  40 A works similarly to the weld bead  40  of  FIGS. 3 and 4  to deflect a fluid, as will be discussed below. Another example of a deflector may be a curved object attached or positioned below the outer edge of the vanes  28 . Also, while the deflectors  40 ,  40 A are shown to extend continuously 360°, it is understood that the deflector may be formed from a series of discontinuous segments on the wall  26  or on the vanes  28  adjacent the area of fluid flow past the vanes  28 . 
     In use, the torque converter  10  contains a fluid, such as an oil. When the engine drive shaft begins to rotate, the input shaft  34  will rotate the impeller  20 . The spinning of the impeller  20  produces centrifugal forces on the fluid, which forces the fluid between the vanes  28  along the outer wall  26 . The impeller vanes  28  are oriented to direct the fluid towards the turbine vanes  32 . The deflector  40 ,  40 A directs the fluid towards the turbine  22 , in such a way that the fluid will not overshoot the outer edge of the turbine or get behind the turbine. Because the impeller vanes  28  and the turbine vanes  32  are oriented opposite of one another, when the fluid is directed by the deflector  40 .  40 A and the impeller vanes  28 , it will be forced against the turbine vanes  32  to produce a rotation of the turbine  22 . The rotation of the turbine rotates the output shaft  36 , which is connected to the transmission  14 , so as to drive the vehicle wheels  18 . The transfer of fluid from the impeller  20  to the turbine  22  without the loss of fluid as in prior art torque converters, improves the efficiency of a vehicle. 
     The orientation of the turbine vanes  32  will force the fluid towards the center of the turbine  22 . The fluid will then contact the vanes of the stator  24 , which directs the fluid back towards the vanes  28  of the impeller  20 . This transfer of fluid creates a cycle wherein the fluid transfers from the impeller  20  to the turbine  22 , through the stator  24 , and back to the impeller  20 . As the rotational speed of the impeller  20  increases with the rotational speed of the engine  12 , the rotational speed of the turbine  22  will increase. At lower vehicle speeds, the impeller  20  will be rotating at a higher speed than the turbine  22 .This difference in rotational speed is energy loss, and produces heat in the torque converter  10 .At a certain rotational speed, the impeller  20  and the turbine  22  will be rotating at substantially the same rotational speed. At this time, the locking mechanism, such as a lockup clutch, will lock the rotation of the turbine  22  with the rotation of the impeller  20 ,thus synchronizing the rotation of the torque converter  10 . At this moment, 100% of the input from the engine  12  is being outputted through the torque converter  10  to the transmission  14 , to produce the greatest fuel efficiency for the vehicle. Because the impeller vanes  28  contain the deflector  40 ,  40 A, the locking clutch will engage upon command. Additionally, the deflector  40 ,  40 A will ensure that fluid does not get behind the turbine  22 , which may cause the lock mechanism to overheat or not lock, which produces a much lower fuel efficiency, and could also potentially overheat the transmission  14 . 
     The invention has been shown and described above with reference to the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made all within the intended spirit and scope of the invention. The invention is only to be limited by claims appended hereto.