A motor comprising: a housing; a stator disposed in the housing; an integrated nut spindle disposed to be rotatable relative to the stator; a ball spindle that is coupled to the integrated nut spindle and moves linearly when the integrated nut spindle is rotated, wherein said integrated nut spindle includes a core having a first through-hole through which the ball spindle passes and pockets in which magnets are mounted and supports disposed axially on opposite sides of the core, the supports having second through-holes larger than the first through-hole; wherein a radial thickness of the core is greater than that of each support; wherein the ball spindle is provided with first threads on an outer circumferential surface thereof and the core is provided with second threads on an inner circumferential surface of the first through-hole so as to correspond to the first threads (1 10a) of the ball spindle, wherein balls are inserted between the first and the second threads (110a, 122a); wherein the integrated nut spindle is configured to rotate by an electromagnetic interaction between the stator and the magnets of the integrated nut spindle, so that the ball spindle screwed onto the integrated nut spindle moves linearly; characterized in that opposite ends of the nut spindle are supported by bearings (300, 400), each attached to a radially outer surface of one of the supports; in that an outer diameter of the core is greater than an outer diameter of each support and in that pockets are defined by a plurality bar shaped protrusions in axial direction disposed in parallel along the outer circumferential surface of the core, so that the magnets are attached to the outer circumferential surface of the core. a housing; a stator disposed in the housing; an integrated nut spindle disposed to be rotatable relative to the stator; a ball spindle that is coupled to the integrated nut spindle and moves linearly when the integrated nut spindle is rotated, wherein said integrated nut spindle includes a core having a first through-hole through which the ball spindle passes and pockets in which magnets are mounted and supports disposed axially on opposite sides of the core, the supports having second through-holes larger than the first through-hole; wherein a radial thickness of the core is greater than that of each support; wherein the ball spindle is provided with first threads on an outer circumferential surface thereof and the core is provided with second threads on an inner circumferential surface of the first through-hole so as to correspond to the first threads (1 10a) of the ball spindle, wherein balls are inserted between the first and the second threads (110a, 122a); wherein the integrated nut spindle is configured to rotate by an electromagnetic interaction between the stator and the magnets of the integrated nut spindle, so that the ball spindle screwed onto the integrated nut spindle moves linearly; characterized in that opposite ends of the nut spindle are supported by bearings (300, 400), each attached to a radially outer surface of one of the supports; in that an outer diameter of the core is greater than an outer diameter of each support and in that pockets are defined by a plurality bar shaped protrusions in axial direction disposed in parallel along the outer circumferential surface of the core, so that the magnets are attached to the outer circumferential surface of the core.