Fuel pump

A fuel pump comprising:

• a disk-like impeller to be rotatingly driven;
• casing halves which receive said impeller, each casing half having a C-shaped flow channel formed substantially along an outer periphery of said impeller;
• each casing half comprising a pressurizing groove constituting a part of said flow channel, said groove having a predetermined sectional lateral length and being formed along the outer periphery of said impeller;
• an inlet portion formed at one end of said flow channel and enlarged inside of the outer periphery of said impeller so that the sectional lateral length of the channel at the inlet portion is larger than that of said pressurizing groove;
• a suction port for sucking fuel, which extends in an axial direction of said impeller and is positioned inside of the outer periphery of said impeller, said suction port being opened to said inlet portion;
• a discharge port communicating with the other end of said flow channel to discharge the fuel;
• and
• an introduction groove formed between said inlet portion and said pressurizing groove, a sectional lateral length of said introduction groove gradually becoming smaller from said inlet portion toward said pressurizing groove, and a sectional vertical length of said introduction groove gradually becoming smaller from said inlet portion toward said pressurizing groove, while a deepest portion of the introduction groove takes a course gradually shifting from the exit of said suction port toward the outer periphery of said impeller,
• wherein said pressurizing groove is formed concentrically with the outer periphery of said impeller, an inner side edge of said introduction groove extends gradually outwardly from said inlet portion to lead to an inner side edge of said pressurizing groove, and the deepest portion of said introduction groove takes a course gradually shifting from the exit of said suction port toward the outer periphery of said impeller.

A fuel pump comprising:

• an electric motor;
• a disk-like impeller adapted to be driven by said motor;
• a casing containing said impeller therein and having a suction port for sucking fuel at a position inside of an outer periphery of said impeller, an introduction groove connected with said suction port and formed arcuately along the outer periphery of said impeller, a pressurizing groove connected to said introduction groove and formed arcuately along the outer periphery of said impeller, and a discharge port connected to said pressurizing groove for discharging pressurized fuel therefrom;
• said introduction groove having a lateral width which is gradually reduced in a direction of rotation of said impeller and a depth which varies laterally and is gradually reduced in a direction of rotation of said impeller, an inner side wall of said introduction groove being defined by a first arc, of which a center is shifted from a center of said impeller such that said inner side wall is directed to the outside of said impeller from said suction port toward said pressurizing groove, an outer side wall of said introduction groove being defined by a second arc, of which a center is shifted from the center of said impeller such that said outer side wall is directed to the inside periphery of said impeller from said suction port toward said pressurizing groove, and said introduction groove being connected to said suction port continuously and having a bottom depth which is directed to the outside periphery of said impeller from said suction port;
• and
• said pressurizing groove being substantially constant in lateral width and depth, inner and outer side walls of said pressurizing groove being defined by third and fourth arcs which have centers thereof corresponding to the center of said impeller.