Gear Pump

A gear pump comprising:

• a drive shaft adapted to be connected with a drive source;
• a first gear driven by the drive shaft and arranged to form a first pump;
• a first pump chamber in which the first gear is received;
• a second gear driven by the drive shaft and arranged to form a second pump;
• a second pump chamber in which the second gear is received;
• a partition member arranged to separate the first and second pump chambers, formed with a shaft hole extending through the partition member and receiving the drive shaft, and disposed axially between one of side surfaces of the first gear and one of side surfaces of the second gear;
• a first side plate arranged to confront the other of the side surfaces of the first gear;
• a second side plate arranged to confront the other of the side surfaces of the second gear;
• and
• a connecting section connecting the drive shaft with the first and second gears in a manner to prevent relative rotation and to allow relative axial movement, the connecting section including a drive pin which is provided in the drive shaft and which extends radially outwards from the drive shaft, and a recess which is formed in one of the first and second gears, and which is engaged with the drive pin, the drive pin forming a limiting means for limiting the axial movement of the drive shaft, together with one of the partition member and the side plates.

A gear pump comprising:

• a drive shaft adapted to be connected with a drive source;
• a first gear driven by the drive shaft and arranged to form a first pump;
• a first pump chamber in which the first gear is received;
• a second gear driven by the drive shaft and arranged to form a second pump;
• a second pump chamber in which the second gear is received;
• a partition member arranged to separate the first and second pump chambers, and disposed axially between one of side surfaces of the first gear and one of side surfaces of the second gear;
• a first side plate arranged to confront the other of the side surfaces of the first gear;
• a second side plate arranged to confront the other of the side surfaces of the second gear;
• and
• first and second drive pins projecting radially outwards from the drive shaft and engaging, respectively, in a first drive recess formed in the first gear and a second drive recess formed in the second gear so that the first and second gears are driven, respectively, through the first and second drive pins in a manner allowing relative axial movement,
• the first drive pin being arranged to limit axial movement of the drive shaft in a second direction, with the first side plate or the partition member, and the second drive pin being arranged to limit the axial movement of the drive shaft in a first direction opposite to the second direction, with the second side plate or the partition member.

A gear pump comprising:

• a drive shaft;
• a gear driven by the drive shaft;
• a side wall member disposed on one side of the gear;
• a side plate disposed on the other side of the gear, so that the gear is interposed, and sealed so as to restrain leakage of an operating fluid, between the side wall member and the side plate;
• and
• a connecting section connecting the drive shaft with the gear in a manner to prevent relative rotation and to allow relative axial movement between the drive shaft and the gear, the connecting section including a drive projection which is provided in the drive shaft and which projects radially outwards from the drive shaft and a drive recess which is formed in the gear and which is engaged with the drive projection, an axial dimension of the drive projection being smaller than or equal to a width of the gear, the drive projection being arranged to limit the axial movement of the drive shaft relative to the gear, with one of the side wall member and the side plate.