Abstract: A vane pump including a cam ring, a rotor, slits formed in the rotor, vanes inserted slidably into the slits, pump chambers defined by the vanes, back pressure chambers defined between respective base end portions of the vanes and the slits, back pressure grooves capable of communicating with the back pressure chambers as the rotor rotates, and connecting grooves connecting back pressure grooves that are adjacent in a circumferential direction of the rotor to each other, wherein a connecting groove that communicates with a back pressure groove positioned in a suction region formed above a rotary center of the rotor so as to suction a working fluid into the pump chambers is formed to have a larger passage sectional area than a connecting groove that communicates with another back pressure groove positioned in another suction region formed below the rotary center of the rotor.

Abstract: A vane pump including a cam ring, a rotor, slits formed in the rotor, vanes inserted slidably into the slits, pump chambers defined by the vanes, back pressure chambers defined between respective base end portions of the vanes and the slits, back pressure grooves capable of communicating with the back pressure chambers as the rotor rotates, and connecting grooves connecting back pressure grooves that are adjacent in a circumferential direction of the rotor to each other, wherein a connecting groove that communicates with a back pressure groove positioned in a suction region formed above a rotary center of the rotor so as to suction a working fluid into the pump chambers is formed to have a larger passage sectional area than a connecting groove that communicates with another back pressure groove positioned in another suction region formed below the rotary center of the rotor.

Abstract: A solenoid actuator (1) comprises a case (9) made of a magnetic material and housing a coil (12) wound on a bobbin (11), and a pressure tube (17) made of a non-magnetic material and fitted into a hollow portion of the bobbin (11). A base (2) and a sleeve (3) made of a magnetic material are disposed in the pressure tube (17). A plunger (4) provided in an operation chamber (74, 75) formed in the base (2) and the sleeve (3) strokes according to energization of the coil (12) to axially drive a shaft (5) fixed to the plunger (4). The pressure tube (17) ensures that magnetic flux is transferred between the case (9) and the sleeve (3) while preventing pressure variation in the operation chamber (74, 75) from being transmitted to the bobbin (11), thereby achieving a high response and a pressure tightness in the solenoid actuator (1).

Abstract: A solenoid actuator (1) comprises a case (9) made of a magnetic material and housing a coil (12) wound on a bobbin (11), and a pressure tube (17) made of a non-magnetic material and fitted into a hollow portion of the bobbin (11). A base (2) and a sleeve (3) made of a magnetic material are disposed in the pressure tube (17). A plunger (4) provided in an operation chamber (74, 75) formed in the base (2) and the sleeve (3) strokes according to energization of the coil (12) to axially drive a shaft (5) fixed to the plunger (4). The pressure tube (17) ensures that magnetic flux is transferred between the case (9) and the sleeve (3) while preventing pressure variation in the operation chamber (74, 75) from being transmitted to the bobbin (11), thereby achieving a high response and a pressure tightness in the solenoid actuator (1).