A priming pump may include a housing; an inlet passageway inside of the housing; an outlet passageway inside of the housing; a divider, inside of the housing, separating the inlet passageway and the outlet passageway; a connecting passageway through the divider in fluid communication with the inlet passageway and the outlet passageway; a valve, disposed in the connecting passageway, configured for one-way fluid flow from the inlet passageway to the outlet passageway; a rotary pump, inside of the housing, having an inlet in fluid communication with the inlet passageway and an outlet in fluid communication with the outlet passageway; and a shaft connected to the rotary pump and extending through the housing, the shaft configured for rotation by an external driving mechanism.

A fuel pump includes a cam arrangement surrounding a rotor and disposed within a spacer ring. The cam arrangement is configured to deterministically translate relative to the spacer ring and the rotor during stroking of the pump. An involute gear set provides an interface between the cam arrangement and the spacer ring. In some cases, the involute gear set is configured to provide a linear translation of the cam arrangement along a timing line. In other cases, the involute gear set is configured to provide a linear translation of the cam arrangement at an angle relative to the timing line.

A fuel pump includes a cam arrangement surrounding a rotor and disposed within a spacer ring. The cam arrangement is configured to deterministically translate relative to the spacer ring and the rotor during stroking of the pump. An involute gear set provides an interface between the cam arrangement and the spacer ring. In some cases, the involute gear set is configured to provide a linear translation of the cam arrangement along a timing line. In other cases, the involute gear set is configured to provide a linear translation of the cam arrangement at an angle relative to the timing line.

An inner gear includes: sliding surface parts that are provided annularly at an outer peripheral part including a plurality of outer teeth on both sides of the inner gear in its axial direction and that slide on a pump housing; recessed parts that are respectively provided radially inward of the sliding surface parts to respectively form fuel chambers, into which fuel flows, between the recessed parts and the pump housing; and a communication hole that communicates between the recessed parts. The inner gear further includes an inclined surface part that is provided at an edge portion of a communicating edge portion on a rotation advance side of the inner gear, to avoid an adjacent part adjacent to an inner peripheral edge portion of each of the sliding surface parts and that is inclined further toward a rear side in a direction to a central part of the communication hole.

An inner gear includes: sliding surface parts that are provided annularly at an outer peripheral part including a plurality of outer teeth on both sides of the inner gear in its axial direction and that slide on a pump housing; recessed parts that are respectively provided radially inward of the sliding surface parts to respectively form fuel chambers, into which fuel flows, between the recessed parts and the pump housing; and a communication hole that communicates between the recessed parts. The inner gear further includes an inclined surface part that is provided at an edge portion of a communicating edge portion on a rotation advance side of the inner gear, to avoid an adjacent part adjacent to an inner peripheral edge portion of each of the sliding surface parts and that is inclined further toward a rear side in a direction to a central part of the communication hole.

An inner gear includes an insertion hole, which extends through the inner gear in an axial direction, and a first balance groove, which is axially recessed at an axial end portion of the inner gear and is communicated with the insertion hole. First and second chamfered portions are formed in an inner peripheral edge of the inner gear, which is adjacent to the insertion hole. A joint member has a leg inserted into the insertion hole. An inserting direction of the leg into the insertion hole is defined as a first direction, and a direction, which is opposite from the first direction, is defined as a second direction. In a view taken in a direction perpendicular to the axial direction, at least a part of a first direction side end portion of the leg is axially placed between a first chamfered end plane and a first groove end plane.

An inner gear includes an insertion hole, which extends through the inner gear in an axial direction, and a first balance groove, which is axially recessed at an axial end portion of the inner gear and is communicated with the insertion hole. First and second chamfered portions are formed in an inner peripheral edge of the inner gear, which is adjacent to the insertion hole. A joint member has a leg inserted into the insertion hole. An inserting direction of the leg into the insertion hole is defined as a first direction, and a direction, which is opposite from the first direction, is defined as a second direction. In a view taken in a direction perpendicular to the axial direction, at least a part of a first direction side end portion of the leg is axially placed between a first chamfered end plane and a first groove end plane.

A fuel pump includes a housing, a pump section disposed within the housing on a first side thereof, a motor section disposed within the housing on a second side thereof and communicating with the pump section, and an upper body closing an end of the housing on the second side. A fuel chamber, into which fuel flows from the pump section through the motor section toward the second side of the housing, and a first branch fuel path, which is connected to the fuel chamber, are provided between the upper body and a motor. A discharge port is connected to the fuel chamber. A supply port is connected to the first branch fuel path, and the fuel in the fuel chamber is provided to the supply port through the first branch fuel path.

A fuel pump includes a housing, a pump section disposed within the housing on a first side thereof, a motor section disposed within the housing on a second side thereof and communicating with the pump section, and an upper body closing an end of the housing on the second side. A fuel chamber, into which fuel flows from the pump section through the motor section toward the second side of the housing, and a first branch fuel path, which is connected to the fuel chamber, are provided between the upper body and a motor. A discharge port is connected to the fuel chamber. A supply port is connected to the first branch fuel path, and the fuel in the fuel chamber is provided to the supply port through the first branch fuel path.

The present invention discloses an anti-decompression gear fuel pump for broken bubbles, characterized by comprising: a drive motor; and a pump body and a pump cover successively installed on the top end of the drive motor, wherein the pump body is provided with a groove, and a driving gear, a left driven gear and a right driven gear which are installed in the groove and are linked through a motor shaft of the drive motor; meanwhile, the driving gear is respectively internally engaged with the left driven gear and the right driven gear; the pump cover is provided with an A end of a fuel outlet, a D end of a circulating fuel outlet, a B end of a circulating fuel inlet, and a C end of a fuel inlet; and the A end of the fuel outlet, the D end of the circulating fuel outlet, the B end of the circulating fuel inlet, and the C end of the fuel inlet are penetrated into the groove of the pump body. The anti-decompression gear fuel pump for broken bubbles, designed in the present invention, not only solves a decompression problem generated because bubbles appear in a fuel pipeline, but also has scientific and reasonable structure.