A motor including a motor unit including a stator, a rotor and a rotation shaft receiving a rotary power from the rotor, and a housing accommodating the motor unit, the motor comprising: a first housing accommodating the motor unit and including a hitching rim extending from the upper inner surface of the first housing toward the center of the first housing; a second housing interposed between the first housing and the motor unit and including a first flange unit protruded to an upper outer surface of the second housing for a space distanced from the first housing and a second flange protruded to a bottom outer surface of the second housing; a first cover coupled to an upper surface of the first housing and the second housing; a second cover coupled to a bottom surface of the first housing and the second housing: characterized by: a first array unit formed at a bottom surface of the first cover to array a centrality of the second housing by pressing the first flange unit to an inner surface of the first housing; and a second array unit formed at a bottom surface of the second cover to array a centrality of the second housing by pressing the second flange unit to an inner surface of the first housing, wherein the first array unit is brought into close contact with the inner surface of the second housing, and wherein a periphery of the second array unit is brought into close contact with the inner surface of the second housing. a first housing accommodating the motor unit and including a hitching rim extending from the upper inner surface of the first housing toward the center of the first housing; a second housing interposed between the first housing and the motor unit and including a first flange unit protruded to an upper outer surface of the second housing for a space distanced from the first housing and a second flange protruded to a bottom outer surface of the second housing; a first cover coupled to an upper surface of the first housing and the second housing; a second cover coupled to a bottom surface of the first housing and the second housing: characterized by: a first array unit formed at a bottom surface of the first cover to array a centrality of the second housing by pressing the first flange unit to an inner surface of the first housing; and a second array unit formed at a bottom surface of the second cover to array a centrality of the second housing by pressing the second flange unit to an inner surface of the first housing, wherein the first array unit is brought into close contact with the inner surface of the second housing, and wherein a periphery of the second array unit is brought into close contact with the inner surface of the second housing. a first array unit formed at a bottom surface of the first cover to array a centrality of the second housing by pressing the first flange unit to an inner surface of the first housing; and a second array unit formed at a bottom surface of the second cover to array a centrality of the second housing by pressing the second flange unit to an inner surface of the first housing, wherein the first array unit is brought into close contact with the inner surface of the second housing, and wherein a periphery of the second array unit is brought into close contact with the inner surface of the second housing.