A motor converts electric energy into kinetic energy. The motor is classified into a rotating motor that converts electric energy to a rotational movement force and a reciprocating motor that converts electric energy to a linear movement force.
FIGS. 1, 2 illustrate one embodiment of the reciprocating motor. As shown therein, the reciprocating motor includes a stator (S) including an outer core 100 and an inner core 200 inserted in the outer core 100; and a mover 300 movably inserted between the outer core 100 and the inner core 200 of the stator. The mover 300 includes a permanent magnet 310 and a magnet holder 320 supporting the permanent magnet 310. A winding coil 400 and a bobbin 510 around which the winding coil 400 is wound are coupled to the inside of the outer core 100, and the winding oil 400 may be coupled to the inner core 200.
The outer core 100 is formed in a cylindrical shape having a certain diameter and has a certain width. When viewed in a circumferential direction, the outer core 100 includes an opening groove 110 inwardly opened so that the winding coil 400 and the bobbin 410 are positioned therein; a pass portion 120, an outer side of the opening groove 110, through which a flux flows; and pole portions 130, both end portions of the pass portion 120, for forming poles.
The inner core 200 is formed in a cylindrical shape having a certain width. When viewed in a circumferential direction, the inner core 200 has a rectangular shape having certain width and a certain length.
The bobbin 410 is formed in a ring shape, and the winding oil 400 is made such that a wire is wound around the bobbin 410 plural times.
Non-explained reference numerals 411, 140 are a terminal part and a fixing ring, respectively.
Operations of the reciprocating motor will now be described.
When power is applied to the reciprocating motor, a current flows through the winding coil 400, and a flux is formed around the winding coil 400 by the current flowing through the winding coil 400. The flux formed around the winding coil 400 forms a closed loop along the pass portion 120 of the outer core and the inner core 200.
By interaction between the flux formed along the pass portion 120 of the outer core and the inner core 200 by the current flowing through the winding coil 400 and the permanent magnet 310 of the mover, a force is applied to the permanent magnet 310 in an axial direction. The permanent magnet 310 and the magnet holder 320 are moved in an axial direction by the force applied to the permanent magnet 310. And, a direction of the current supplied to the winding coil 400 is alternatively changed, thereby linearly reciprocating the mover 300.
The outer core 100 and the inner core 200 constituting the stator (S) are various in shapes and in their production method. In order to minimize loss of flux, the outer core 100 and the inner core 200 of the stator are usually fabricated by stacking a plurality of thin plates having a prescribed shape.
FIG. 3 is a perspective view showing a disassembled outer core of the stator.
As shown therein, the outer core 100 is made such that a plurality of lamination sheets (L1) having a prescribed shape is stacked at a ring-shaped bobbin 410, and fixing rings 140 are respectively coupled to both sides of a laminated assembly. The lamination sheets (L1) are radially and alternatively stacked to the bobbin 410. The laminated assembly is formed in a cylindrical shape.
Such an outer core 100 of the stator is made as a plurality of lamination sheets (L1) is radially and alternatively stacked so as to have a ring shape, and fixing rings 140 are coupled to both sides of the laminated assembly. Accordingly, it is difficult to assemble the outer core and it takes much time to assemble the outer core, thereby deteriorating its productivity.
FIG. 4 illustrates another embodiment of the stator.
As shown therein, the outer core of the stator is made such that a unit laminated assembly (LU1) with a certain thickness is constructed of a plurality of lamination sheets (L2), the unit laminated assemblies (LU1) are radially coupled to a ring-shaped bobbin 410, and fixing rings 140 are respectively coupled to both sides of the plurality of unit laminated assemblies (LU1).
An inner surface and an outer surface of the unit laminated assembly (LU1) are formed curved by a plurality of lamination sheets 12. The inner surfaces of the unit laminated assemblies (LU1) coupled to the bobbin 410 form a circle, and their outer surfaces are spaced apart from each other, maintaining certain intervals therebetween.
The bobbin 410 includes a ring-shaped body 412 having a ring-shaped winding groove (not shown) in a circumferential direction therein, and a ring-shaped Over 413 for covering the winding groove of the ring-shaped body 412. The winding oil 400 is positioned in the winding groove of the ring-shaped body 412, and a terminal part 411 is formed at one side of the ring-shaped body 412.
Such a structure is relatively easy to assemble as compared to the above-mentioned ring-shaped outer core 100, since unit laminated assemblies (LU1) are coupled to the bobbin 410.
However, such an outer core of the stator is made such that the unit laminated assembly (LU1) is coupled to the bobbin 410, and then ring-shaped fixing rings 140 are respectively coupled to both sides of unit laminated assemblies (LU1). Thus, it is not easy to finely fabricate the fixing rings 140, and an assembling operation of making the fixing rings 140 fixedly coupled to both sides of the unit laminated assemblies (LU1) becomes complicated and difficult. That is, a ring groove 150 formed at the unit laminated assembly (LU1), in which the fixing ring 140 is coupled, is formed by grooves formed at each lamination sheet (L2) constructing the unit laminated assembly (LU1). At this time, it is complicated and difficult to form grooves at each lamination sheet 12 and make the fixing ring 140 coupled to the grooves, thereby deteriorating assembly productivity.