Rotary swash plate hydraulic pump

A rotary swash plate hydraulic pump comprising:

• a casing;
• a cylinder block that is disposed in the casing so as to prevent relative rotation of the cylinder block and including a plurality of cylinder bores;
• a plurality of pistons each of which is inserted into a corresponding one of the plurality of cylinder bores;
• a rotary swash plate that is housed in the casing so as to be rotatable about an axis and reciprocates each of the plurality of pistons;
• and
• a variable capacity mechanism that changes an effective stroke length of at least one of the plurality of pistons, wherein:
• the casing includes a discharge passage connected to each of the plurality of cylinder bores, and an inlet passage including an inlet-end ring-shaped portion in the shape of a ring to which each of the plurality of cylinder bores is connected;
• the discharge passage is formed in the shape of a ring so as to surround the plurality of cylinder bores;
• the variable capacity mechanism includes a plurality of spools that open and close paths between the plurality of cylinder bores and a tank;
• the cylinder block includes a plurality of spool holes into each of which a corresponding one of the plurality of spools is inserted;
• and
• each of the plurality of spools is positioned inward of the plurality of cylinder bores and connected to the inlet passage.