Abstract: A bearing is located with movement of an outer race in the longitudinal direction of a drive shaft being restricted, and the drive shaft is fixed to an inner race with the press fit, so that, it is possible to prevent the drive shaft from escaping. In addition, the inner race is longer than the outer race. Therefore, it is possible to obtain sufficient strength of the press fit of the drive shaft in the inner race while suppressing the size of the outer race (in other words, suppressing the size of the pump device). As a consequence, the size of the pump device can be suppressed while increasing reliability of the function for preventing the drive shaft from escaping.

Abstract: A pump body includes a cylindrical first case for housing the plurality of rotary pumps, a second case located coaxially with the first case, and a disk spring located between the first case and the second case. In addition, a fixing means located at an entrance of the concave portion of a housing presses the second case in the insertion direction of the pump body and fixes the second case.

Abstract: The curvature of a circular arc constituted by a side of a suction groove is made larger than that of a circular arc constituted by a side of a discharge groove. Thus, when the suction groove and the discharge groove are viewed in the axial direction of a drive shaft, the distance between the suction groove and the discharge groove in the radial direction of a rotary portion is short in a region intersecting with a line W perpendicular to a centerline, and increases in accordance with a decrease in distance from containment portions. It is therefore possible to ensure a sufficient distance between the discharge and suction grooves and enhance a total fluid pressure generated therebetween, and the contact surface pressure that is necessitated by a second side plate to obtain a press-back force when being in contact with an outer rotor and an inner rotor is reduced.

Abstract: A bearing is located with movement of an outer race in the longitudinal direction of a drive shaft being restricted, and the drive shaft is fixed to an inner race 51c with the press fit, so that, it is possible to prevent the drive shaft from escaping. In addition, the inner race is longer than the outer race. Therefore, it is possible to obtain sufficient strength of the press fit of the drive shaft in the inner race 51c while suppressing the size of the outer race (in other words, suppressing the size of the pump device). As a consequence, the size of the pump device can be suppressed while increasing reliability of the function for preventing the drive shaft from escaping.

Abstract: A pump body includes a cylindrical first case for housing the plurality of rotary pumps, a second case located coaxially with the first case, and a disk spring located between the first case and the second case. In addition, a fixing means located at an entrance of the concave portion of a housing presses the second case in the insertion direction of the pump body and fixes the second case.

Abstract: The curvature of a circular arc constituted by a side of a suction groove is made larger than that of a circular arc constituted by a side of a discharge groove. Thus, when the suction groove and the discharge groove are viewed in the axial direction of a drive shaft, the distance between the suction groove and the discharge groove in the radial direction of a rotary portion is short in a region intersecting with a line W perpendicular to a centerline, and increases in accordance with a decrease in distance from containment portions. It is therefore possible to ensure a sufficient distance between the discharge and suction grooves and enhance a total fluid pressure generated therebetween, and the contact surface pressure that is necessitated by a second side plate to obtain a press-back force when being in contact with an outer rotor and an inner rotor is reduced.

Abstract: A leaf spring for urging a spool toward a flange part of a yoke is provided between a guide fixed to a housing and the spool. Owing to the urging force of the leaf spring, the spool is pressed against the flange part of the yoke, and the yoke can be pressed against the cover through the spool. Thus it is possible to prevent the spool and the yoke from loosening. Further because the leaf spring is provided for each magnet valve, the leaf spring can be commonly used for respective modes of a fluid control apparatus and thus the cost can be reduced.

Abstract: A leaf spring for urging a spool toward a flange part of a yoke is provided between a guide fixed to a housing and the spool. Owing to the urging force of the leaf spring, the spool is pressed against the flange part of the yoke, and the yoke can be pressed against the cover through the spool. Thus it is possible to prevent the spool and the yoke from loosening. Further because the leaf spring is provided for each magnet valve, the leaf spring can be commonly used for respective modes of a fluid control apparatus and thus the cost can be reduced.