Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2011-0030994, filed on 5 Apr. 2011, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The following disclosure relates to a turbine fuel pump for a vehicle. More particularly, the following disclosure relates to a turbine fuel pump for a vehicle that can improve efficiency of the fuel pump and solve pressure instability caused by collision of fuel by forming a separate independent channel in a lower casing, an impeller, and an upper casing where channels of fuel are formed at the time of suctioning fuel from the fuel tank and supplying fuel to an engine of an internal combustion engine. 
       BACKGROUND 
       [0003]    In general, a fuel pump of a vehicle is mounted on the inside of a fuel tank of the vehicle and serves to suction fuel and pressure-feed the suctioned fuel to a fuel injection device mounted in an engine. 
         [0004]    In addition, the fuel pump for the vehicle is classified into a mechanical fuel pump and an electrical fuel pump and a turbine fuel pump  10  which is a type of electrical fuel pump is primarily used in an engine using gasoline as fuel. 
         [0005]    In the turbine fuel pump  10 , a driving motor  20  is provided in a motor housing  60  of the fuel pump  10 , an upper casing  30  and a lower casing  40  are provided on a lower end part of the motor housing  60  to be closely attached to each other, and an impeller  50  is interposed therebetween as shown in  FIG. 1 . 
         [0006]    In addition, the impeller  50  is joined to a rotational shaft  21  of a driving motor  20 , such that the impeller  50  is configured to rotate with the driving motor  20 . 
         [0007]    That is, as the impeller  50  rotates, a pressure difference is generated, and as a result, fuel is suctioned into the impeller  50  and while the pressure of fuel is increased by a rotation flow generated by continuous rotation of the impeller  50 , fuel is discharged. 
         [0008]    Therefore, fuel is introduced into a fuel suction port  41  of the lower casing  40  to flow to a check valve  70  formed in an upper part of the motor housing  60  along an inner part of the motor housing  60  through a fuel discharge port  31  of the upper casing  30  with the pressure thereof increased through the rotating impeller  50  and supplied to the fuel injection device mounted on the engine of the vehicle. 
         [0009]    In this case, the impeller  50  is formed in a disk shape, a plurality of blades  51  are formed on an circumferential surface thereof in an outer direction of the circumferential surface, blade chambers  52  are formed among respective blades  51  to penetrate through both surfaces of the impeller  50  as shown in  FIG. 2 , such that fuel is introduced and discharged individually in an upper part and a lower part of the blade chamber  52  and fuel is introduced into the fuel suction port  41  of the lower casing  40  to generate the rotation flow in a space between a blade chamber  52  and a lower channel groove  42  formed in the lower casing  40  and an upper channel groove  32  formed in the upper casing  30  as shown in  FIG. 3 , and a circulation process in which fuel is again introduced into the neighboring blade chamber  52  to generate the rotation flow is repeated. Therefore, kinetic energy generated by the rotation of the impeller  50  is converted into pressure energy of fuel, and as a result, fuel is delivered to the fuel discharge port  31  of the upper casing  30 . 
         [0010]    In addition, in the impeller  50  in the related art, a circumference center guide  53  is formed at the center of the circumferential surface along the circumferential surface of the impeller  50  so as to efficiently generate the rotation flow formed in the space between the blade chamber  52  and the lower channel groove  42  and the rotation flow generated in the space between the impeller chamber  52  and the upper channel groove  32 . 
         [0011]    In this case, as shown in  FIG. 4 , the fuel that flows along the upper channel groove  32  of the upper casing  30  is discharged through the fuel discharge port  31 . However, the fuel that flows along the lower channel groove  42  of the lower casing  40  should be discharged through the fuel discharge port  31  by passing through the blade chamber  52  of the impeller  50 . 
         [0012]    Therefore, the fuel that flows along the lower channel groove  42  hits the blade  51  of the impeller  50  and passes through the blade chamber  51  to interrupt the flow of the rotation flow, thereby causing loss of a fuel movement amount and further, serve as flow resistance of fuel to make the pressure of the fuel pump instable and deteriorate performance. 
         [0013]    Further, with a current technological tendency in which components in the vehicle are gradually subjected to a light weight, a compact size, and high performance in order to satisfy user&#39;s various preferences globally, a study about high performance of even the fuel pump has been required. 
         [0014]    In addition, performance of the fuel pump is determined according to a specification of the vehicle and high efficiency is required as a recent trend. Therefore, the turbine fuel pump for a vehicle in the related art is limitative in increasing a discharge amount of fuel under high pressure. 
       SUMMARY 
       [0015]    An embodiment of the present invention is directed to providing a turbine fuel pump for a vehicle that can improve efficiency of the fuel pump by allowing fuel to pass through a separate independent channel without passing through an impeller blade and solve pressure instability by reducing flow resistance caused by collision of fuel by forming the separate independent channel in a lower casing, an impeller, and an upper casing where channels of fuel are formed. 
         [0016]    In one general aspect, a turbine fuel pump for a vehicle includes: an upper casing  100  including an upper channel groove  120  formed in a lower surface thereof so as to allow fuel to flow therethrough and a fuel discharge port  110  connected to the upper channel groove  120 , formed to penetrate through upper and lower surfaces thereof, and discharging the fuel therethrough; a lower casing  300  joined to a lower part of the upper casing  100  and including a lower channel groove  320  formed in an upper surface thereof so as to allow the fuel to flow therethrough and a fuel suction port  310  connected to the lower channel groove  320 , formed to penetrate through upper and lower surfaces thereof, and introducing the fuel thereinto; and an impeller  200  provided between the upper casing  100  and the lower casing  300 , having a disk shape, and including a plurality of blades  230  formed along an outer circumferential surface in an outer direction of the outer circumferential surface and blade chambers  240  each formed between the blades  230  so as to penetrate through upper and lower surfaces thereof to allow the fuel to be discharged and introduced in upper and lower parts of the blades  230 , respectively, wherein the upper casing  100  includes an upper inner channel  140  formed to be spaced apart from a shaft penetration hole  130  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, the impeller  200  includes an impeller channel  260  formed to be spaced apart from a shaft fixation hole  220  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, and the lower casing  300  includes a lower inner channel  340  formed at the center of the upper surface thereof and a lower connection groove  350  connecting the lower inner channel  340  and the lower channel groove  320  to each other, such that a separate channel is formed so that the fuel suctioned into the fuel suction port  310  flows along the lower channel groove  320  by rotation of the impeller  200 , is introduced into the lower inner channel  340  through the lower connection groove  350 , and passes through the impeller channel  260  to be discharged through the upper inner channel  140 . 
         [0017]    Further, one side of the lower connection groove  350  may be connected to the lower inner channel  340  and the other side thereof may be connected to the lower channel groove  320  and one side of the lower connection groove  350  may be connected to an opposite end of the lower channel groove  320  connected to the fuel suction port  310 . 
         [0018]    Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a cross-sectional view illustrating a schematic configuration of a turbine fuel pump for a vehicle in the related art. 
           [0020]      FIG. 2  is a perspective view illustrating an impeller in the related art. 
           [0021]      FIG. 3  is a cross-sectional view illustrating a flow of fuel in the fuel pump in the related art. 
           [0022]      FIG. 4  is a schematic diagram illustrating the flow of fuel at a fuel outflow portion of the fuel pump in the related art. 
           [0023]      FIG. 5  is a partial exploded perspective view illustrating a turbine fuel pump for a vehicle according to an exemplary embodiment. 
           [0024]      FIG. 6  is a cross-sectional view illustrating a flow of fuel in the turbine fuel pump according to the exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF MAIN ELEMENTS 
       [0000]    
       
           10 : Fuel pump 
           20 : Motor 
           21 : Rotational shaft 
           30 : Upper casing 
           31 : Fuel discharging port 
           32 : Upper channel groove 
           40 : Lower casing 
           41 : Fuel suction port 
           42 : Lower channel groove 
           50 : Impeller 
           51 : Blade 
           52 : Blade chamber 
           53 : Circumference center guider 
           60 : Motor housing 
           70 : Check valve 
           1000 : Turbine fuel pump for vehicle (present invention) 
           100 : Upper casing 
           110 : Fuel discharge port 
           120 : Upper channel groove 
           130 : Shaft penetration hole 
           140 : Upper inner channel 
           200 : Impeller 
           210 : Impeller body 
           220 : Shaft fixation hole 
           230 : Blade 
           240 : Blade chamber 
           250 : Side ring 
           260 : Impeller channel 
           300 : Lower casing 
           310 : Fuel suction port 
           320 : Lower channel groove 
           330 : Shaft support groove 
           340 : Lower inner channel 
           350 : Lower connection groove 
           360 : Ball 
       
     
       DETAILED DESCRIPTION OF EMBODIMENTS 
       [0060]    A turbine fuel pump for a vehicle includes: an upper casing  100  including an upper channel groove  120  formed in a lower surface thereof so as to allow fuel to flow therethrough and a fuel discharge port  110  connected to the upper channel groove  120 , formed to penetrate through upper and lower surfaces thereof, and discharging the fuel therethrough; a lower casing  300  joined to a lower part of the upper casing  100  and including a lower channel groove  320  formed in an upper surface thereof so as to allow the fuel to flow therethrough and a fuel suction port  310  connected to the lower channel groove  320 , formed to penetrate through upper and lower surfaces thereof, and introducing the fuel thereinto; and an impeller  200  provided between the upper casing  100  and the lower casing  300 , having a disk shape, and including a plurality of blades  230  formed along an outer circumferential surface in an outer direction of the outer circumferential surface and blade chambers  240  each formed between the blades  230  so as to penetrate through upper and lower surfaces thereof to allow the fuel to be discharged and introduced in upper and lower parts of the blades  230 , respectively, wherein the upper casing  100  includes an upper inner channel  140  formed to be spaced apart from a shaft penetration hole  130  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, the impeller  200  includes an impeller channel  260  formed to be spaced apart from a shaft fixation hole  220  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, and the lower casing  300  includes a lower inner channel  340  formed at the center of the upper surface thereof and a lower connection groove  350  connecting the lower inner channel  340  and the lower channel groove  320  to each other, such that a separate channel is formed so that the fuel suctioned into the fuel suction port  310  flows along the lower channel groove  320  by rotation of the impeller  200 , is introduced into the lower inner channel  340  through the lower connection groove  350 , and passes through the impeller channel  260  to be discharged through the upper inner channel  140 . 
         [0061]    Hereinafter, the respective components will be described in more detail with reference to the accompanying drawings. 
         [0062]      FIG. 5  is a partial exploded perspective view illustrating a turbine fuel pump for a vehicle according to an exemplary embodiment. 
         [0063]    As shown in  FIG. 5 , in the turbine fuel pump  1000  for a vehicle according to the exemplary embodiment, an upper casing  100  and a lower casing  300  are joined to a lower end part of a motor housing  60  constituting the fuel pump and an impeller  200  is interposed therebetween. 
         [0064]    In this case, the impeller  200  is configured to rotate in contact with the lower surface of the upper casing  100  and the upper surface of the lower casing  300 , and a rotational shaft  21  of a motor  2  is joined to the impeller while penetrating through a shaft penetration hole  130  formed at the center of the upper casing  100  and penetrating through a shaft fixation hole  220  formed at the center of an impeller body  210  of the impeller  200 , such that the impeller  200  rotates in accordance with rotation of the rotational shaft  21  of the motor  20 . In addition, a lower part of the rotational shaft  21  penetrating through the shaft fixation hole  220  of the impeller body  210  is inserted into a shaft support groove  330  formed at the center of the lower casing  300  and a lower end surface of the rotational shaft  21  contacts a ball  360  joined to the shaft support groove  330  and is supported by the ball  360 . 
         [0065]    In addition, referring to  FIGS. 5 and 6 , the impeller  200  has a disk shape and includes a plurality of blades  230  formed along an outer circumferential surface in an outer direction of the outer circumferential surface, a side ring  250  formed on an outer surface of the plurality of blades  230 , and blade chambers  240  each formed between the blades  230  so as to penetrate through upper and lower surfaces thereof to allow the fuel to be discharged and introduced in upper and lower parts of the blades  230 , respectively. 
         [0066]    Further, the lower casing  300  includes a lower channel groove  320  formed in an upper surface thereof so as to allow the fuel to flow therethrough and a fuel suction port  310  connected to the lower channel groove  320 , formed to penetrate through upper and lower surfaces thereof and introducing the fuel thereinto, and the upper casing  100  includes an upper channel groove  120  formed in a lower surface thereof and having fuel flowing therethrough and a fuel discharge port  110  connected to the upper channel groove  120 , formed to penetrate through upper and lower surfaces thereof, and discharging the fuel therethrough. 
         [0067]    In this case, a start portion of the upper channel groove  120  is formed to be opposite to a start portion of the lower channel groove  320 , and an end portion of the upper channel groove  120  is formed to be opposite to an end portion of the lower channel groove  320 . 
         [0068]    Therefore, as the impeller  200  rotates, a pressure difference is generated, such that fuel is suctioned into the fuel suction port  310  of the lower casing  300  and some of the fuel passes through the blade chamber  240  of the impeller  200  and flows along the upper channel groove  120  positioned in the upper part of the blade chamber  240  to be discharged through the fuel discharge port  110  and the rest of the fuel flows along the lower channel groove  320  positioned in the lower part of the blade chamber  240  and passes through the blade chamber  240  at the end portion of the lower channel groove  320  to be discharged through the fuel discharge port  110 . 
         [0069]    That is, the rotation flow is formed in each of the upper part and the lower part of the blade chamber  240  with the rotation of the impeller  200 , such that the fuel suctioned into the fuel suction port  310  flows along each of the upper channel groove  120  and the lower channel groove  320  and passes through the blade chamber  240  of the impeller  200  at the end portion of the lower channel groove  320  to be joined and discharged in the fuel discharge port  110 . 
         [0070]    The turbine fuel pump for a vehicle that has the above structure and where fuel flows is called a side channel type and the fuel that flows along the lower channel groove  320  in the suctioned fuel is configured to be discharged through the fuel discharge port  110  only when it passes through the blade chamber  240  at the end portion of the lower channel groove  320 . 
         [0071]    Here, the upper casing  100  includes an upper inner channel  140  formed to be spaced apart from a shaft penetration hole  130  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, the impeller  200  includes an impeller channel  260  formed to be spaced apart from a shaft fixation hole  220  formed at the center thereof by a predetermined distance and penetrate through the upper and lower surfaces thereof, and the lower casing  300  includes a lower inner channel  340  formed at the center of the upper surface thereof and a lower connection groove  350  connecting the lower inner channel  340  and the lower channel groove  320  to each other 
         [0072]    Here, the respective channels  140 ,  260 , and  340  are passages formed so that fuel may flow, and the lower connection groove  350  is a passage formed so that fuel flows by connecting the lower channel groove  320  and the lower inner channel  340  to each other. 
         [0073]    Further, one side of the lower connection groove  350  is connected to the lower inner channel  340  and the other side of the lower connection groove  350  is connected to the lower channel groove  320 , and one side of the lower connection groove  350  is connected to an opposite end of the lower channel groove  320  connected to the fuel suction port  310 . 
         [0074]    That is, the lower connection groove  350  is preferably formed so that the end portion of the lower channel groove  320  and the lower inner channel  340  are connected to each other. 
         [0075]    In this case, the upper inner channel  140  is formed to be positioned between the shaft penetration hole  130  formed at the center of the upper casing  100  and the upper channel groove  120  formed outside the upper casing  100  and is formed so as not to be connected to the upper channel groove  120 . 
         [0076]    In addition, the impeller channel  260  is formed to be positioned between the shaft fixation hole  220  formed at the center of the impeller body  210  of the impeller  200  and the blade chamber  240  formed outside the impeller body  210  and formed so as not to be connected to the blade chamber  240 . 
         [0077]    Therefore, a separate channel is formed so that the fuel suctioned into the fuel suction port  310  flows along the lower channel groove  320  by rotation of the impeller  200 , is introduced into the lower inner channel  340  through the lower connection groove  350 , and passes through the impeller channel  260  to be discharged through the upper inner channel  140 . 
         [0078]    That is, as shown in  FIG. 6 , when the fuel is introduced into the fuel suction port  310  formed in the lower casing  300 , some of the introduced fuel passes through the blade chamber  240  and flows along the upper channel groove  120  to be discharged through the fuel discharge port  110  of the upper casing  100  and the rest of the fuel flows along the lower channel groove  320  without passing through the blade chamber  240 , is introduced into the lower inner channel  340  through the lower connection groove  350 , and passes through the impeller channel  260  of the impeller  200  positioned in the upper part to be discharged through the upper inner channel  140 . 
         [0079]    Therefore, the fuel that flows along the lower channel groove  320  flows along the separate channel to be discharged without passing through the blade chamber  240  of the impeller  200  to reduce rotation resistance of the impeller  200  and damage of the rotation flow formed in the fuel that flows along the lower channel groove  320 , thereby making it possible to reduce pressure instability of the fuel pump and increase efficiency. 
         [0080]    As set forth above, according to the exemplary embodiment of the present invention, pressure instability can be solved by reducing flow resistance caused due to collision of fuel by allowing fuel to pass through the separate channel without passing through the impeller blade by forming the separate independent channel in the lower casing, the impeller, and the upper casing where channels of fuel are formed. 
         [0081]    Further, damage of a fuel rotation flow caused by the impeller decreases to improve efficiency of a fuel pump. 
         [0082]    The present invention is not limited to the aforementioned exemplary embodiment and an application range is various and it is apparent that various modifications can be made to those skilled in the art without departing from the spirit of the present invention described in the appended claims.

Technology Category: 2