Reactor, converter, and power conversion device

A reactor comprising:

• a coil including a first winding portion;
• and
• a magnetic core,
• wherein the magnetic core includes:
• a middle core arranged inside the first winding portion,
• a first end core facing a first end face of the first winding portion,
• a second end core facing a second end face of the first winding portion,
• a first side core that is arranged outward of a first side face of the first winding portion and connects the first end core and the second end core, and
• a second side core that is arranged outward of a second side face of the first winding portion and connects the first end core and the second end core,
• the first end core includes:
• a first outer face separated from the first end face in an X direction, and
• a first recessed portion provided in the first outer face,
• a cross-section of the first recessed portion orthogonal to a Z direction has a rectangular shape,
• in a plan view of the magnetic core from the Z direction, the first recessed portion is located in a central portion of the first end core with respect to a Y direction,
• in a plan view of the magnetic core from the Z direction, the width of the first recessed portion in the Y direction is 40% or more and 80% or less of the length of the middle core in the Y direction, and the depth of the first recessed portion in the X direction is 50% or more and 66% or less of the length of the first end core in the X direction,
• the X direction is a direction conforming to an axial direction of the middle core,
• the Y direction is a direction in which the middle core, the first side core, and the second side core are side-by-side, and
• the Z direction is a direction orthogonal to the X direction and the Y direction.