A direct drive motor of the outer rotor type comprising: a motor unit including a stator and a rotor rotatable with respect to the stator ; a housing including an inner housing to which the stator is fixed and a rotor flange to which the rotor is fixed, wherein the inner housing and the rotor flange are formed into substantially cylindrical shapes with different diameters and arranged concentrically with respect to a rotation axis (S); a bearing that rotatably supports the rotor flange with respect to the inner housing ; and a rotation detector that detects a rotating state of the motor unit , wherein the rotation detector is a single incremental-type resolver that detects a relative displacement of the rotor with respect to the stator , wherein the resolver includes a resolver rotor and a resolver stator , the resolver rotor being fixed to the rotor flange , and the resolver stator being arranged to face the resolver rotor with a predetermined interval and fixed to an inner ring retainer connected to the inner housing , an inner ring of the bearing is held between the inner housing and the inner ring retainer , the rotor flange includes a collar extending on one axial-direction end surface side of an outer ring of the bearing , and a retaining ring arranged on the other axial-direction end surface side of the outer ring , characterized in that thermosetting resin is filled in a gap between the collar and the one axial-direction end surface of the outer ring of the bearing while compression load is applied by a push-in tool in order to mold a press ring , wherein the compression load is applied in a direction to crush the axial-direction gap between the retaining ring and the bearing . a motor unit including a stator and a rotor rotatable with respect to the stator ; a housing including an inner housing to which the stator is fixed and a rotor flange to which the rotor is fixed, wherein the inner housing and the rotor flange are formed into substantially cylindrical shapes with different diameters and arranged concentrically with respect to a rotation axis (S); a bearing that rotatably supports the rotor flange with respect to the inner housing ; and a rotation detector that detects a rotating state of the motor unit , wherein the rotation detector is a single incremental-type resolver that detects a relative displacement of the rotor with respect to the stator , wherein the resolver includes a resolver rotor and a resolver stator , the resolver rotor being fixed to the rotor flange , and the resolver stator being arranged to face the resolver rotor with a predetermined interval and fixed to an inner ring retainer connected to the inner housing , an inner ring of the bearing is held between the inner housing and the inner ring retainer , the rotor flange includes a collar extending on one axial-direction end surface side of an outer ring of the bearing , and a retaining ring arranged on the other axial-direction end surface side of the outer ring , characterized in that thermosetting resin is filled in a gap between the collar and the one axial-direction end surface of the outer ring of the bearing while compression load is applied by a push-in tool in order to mold a press ring , wherein the compression load is applied in a direction to crush the axial-direction gap between the retaining ring and the bearing . <EOS>