Fuel pump including a protruding portion and connecting an inner gear and a rotary shaft

A fuel pump comprising:

• an outer gear that includes a plurality of internal teeth;
• an inner gear that includes a plurality of external teeth and is eccentric from the outer gear in an eccentric direction to be engaged with the outer gear;
• a pump housing that rotatably accommodates the outer gear and the inner gear;
• an electric motor that includes a rotary shaft which is rotary-driven;
• and
• a joint member that connects together the inner gear and the rotary shaft, wherein:
• the outer gear and the inner gear expand and contract volume of a plurality of pump chambers formed between both the gears, and rotate to suction fuel into the plurality of pump chambers and then discharge fuel from the plurality of pump chambers sequentially;
• the inner gear includes multiple insertion holes, each of which is depressed along its axial direction;
• and
• the joint member includes:
• a main body portion that is fitted to the rotary shaft;
• multiple foot portions, each of which extends from the main body portion along the axial direction and is inserted in each of the insertion holes with a clearance therebetween;
• and
• multiple protruding portions, each of which protrudes from the foot portion toward a rotation progress side of the inner gear and has its width in the axial direction further narrowed toward a top portion of the protruding portion,
• wherein the foot portions are arranged in a circumferential direction of the inner gear in such a way that none of them is located at a point symmetric position with any other foot portions around an inner center line of the inner gear.