PURPOSE: To prevent the occurrence of pulsation owing to air bubbles in working oil and prevents temperature rise by disposing a displacement switching valve to switch one hydraulic pump to a delivery state and a circulation state and an induction part to cause a bypass flow to flow in a state to cross a circulation flow.
CONSTITUTION: Two pumps 4 and 5 are juxtaposed on one and the same rotary shaft 9. In which case, a pressure chamber 62 communicated to the delivery port of a second pump 5 is communicated with the oil introduction chamber of a flow rate control valve 7. In this constitution, a capacity switching valve 8 to always hold the first pump 4 in a delivery state and switch the second pump 5 to a delivery state or a circulation state is disposed. Meanwhile, an induction part 11 is disposed at a portion where a circulation passage 92 is joined with a bypass passage 95. The induction part 11 is disposed to the tip part of a plug 1 and formed such that a bypass flow and a circulation flow are brought into a cross flow state through an induction passage 3. This constitution prevents the occurrence of pulsation owing to air bubbles in working oil and temperature rise.
KATOU TOSHIYA
IKEMOTO HIROYUKI
TOYOTA MOTOR CORP