Patent ID: 7927079

Claim:
An electrically operated hydraulic pump, comprising: a motor portion including a hollow and cylindrical motor housing with a bottom and an opening, the motor portion including a brushless DC motor with a stator fixedly provided in the motor housing, a plurality of exciting coils generating magnetic field, a rotating shaft arranged at a space in the motor housing to be rotatable relative to the stator, a rotor arranged at the space in the motor housing and fixed to the rotating shaft, the rotor including a first magnet facing the exciting coils, and a rotation control means controlling a rotation of the rotor by switching energizing electric current flow from an exciting coil from among the exciting coils to another exciting coil from among the exciting coils in accordance with a rotational position of the rotor; a pump portion connected to one end of the rotating shaft, the pump portion absorbing and exhausting fluid by driving force of the rotating shaft; first rotor position detecting means including speed electromotive force detecting means for detecting speed electromotive force induced by the exciting coils, the first rotor position detecting means detecting the rotational position of the rotor on the basis of a result detected by the speed electromotive force detecting means; second rotor position detecting means including a second magnet provided at the rotating shaft and a magnetic field detecting unit detecting a magnetic field of the second magnet, the second rotor position detecting means detecting the rotational position of the rotor on the basis of a result detected by the magnetic field detecting unit; and motor operating condition detecting means detecting an operating condition of the motor portion, wherein the rotation control means of the motor portion is configured to switch a first rotation controlling based on the rotational position of the rotor detected by the first rotor position detecting means and a second rotation controlling based on the rotational position of the rotor detected by the second rotor position detecting means on the basis of a result detected by the motor operating condition detecting means.