Rotary drive device and pump

A pump comprising:

• a rotor;
• a magnetic bearing that supports the rotor in a contactless manner by a magnetic force;
• a drive unit that rotationally drives the rotor;
• and
• a pump mechanism that includes an impeller which is fitted to the rotor,
• the magnetic bearing comprising:
• a bearing stator disposed on an outer peripheral side of the rotor to support the rotor in a contactless manner by a magnetic force;
• and
• a ring-shaped bearing rotor member provided in the rotor, the bearing rotor member consisting of a magnetic material and forming a magnetic circuit along with the bearing stator,
• the drive unit including:
• a drive stator disposed on an outer peripheral side of the rotor to apply a rotational driving force to the rotor;
• and
• a ring-shaped drive rotor member disposed on an outer peripheral side of the bearing rotor member of the rotor to receive a rotational driving force from the drive stator,
• the bearing stator including:
• a plurality of bearing stator cores disposed on an outer peripheral side of the bearing rotor member, the bearing stator cores consisting of a magnetic material and forming a magnetic circuit along with the bearing rotor member;
• and
• a bearing coil wound around the bearing stator core,
• the bearing stator core including:
• a first portion extending in a first direction orthogonal to a direction facing the bearing rotor member;
• and
• a pair of second portions extending to a bearing rotor member side from both end portions in the first direction of the first portion,
• the bearing coil being wound around the first portion of the bearing stator core, and
• the drive stator being formed so as to pass through a position between an outer peripheral surface of the rotor and the first portion of the bearing stator core and between the pair of second portions of the bearing stator core in the first direction.