PURPOSE: To provide a variable capacity pump which is more favorable in terms of the space and cost than a conventional pump, and the capacity of which is variable.
CONSTITUTION: A drive shaft 2 to which a plurality of gears 4-8a are fixed and a driven shaft 3 to which a plurality of driven gears engaged with the respective drive gears are fixed are arranged in a housing 12, and a partitioning member 13 is arranged between the gears. An oil discharge space 16 formed on the one side of a gear train is communicated to both an oil suction port 15 and an oil delivery port 17 of the housing 12. A spool valve 19 to divide oil, delivered in an oil delivery space 16, into oil discharged to the delivery port side and oil returned to the suction port 15 through a return passage 18 is provided. An amount of oil discharged from a pump and an oil pressure are changed according to a position in the space 16.