Title of Invention

STATOR OF RECIPROCATING MOTOR

Abstract A stator of a reciprocating motor has a ring shaped bobbin (500) having a winding coil (400) therein; a plurality of unit laminated assemblies (LU2) each constructed of a plurality of lamination sheets and coupled to the bobbin in a circumferential direction; a fixing means integrally formed with the bobbin (500) and for fixing the unit laminated assemblies to the bobbin (500); and an inner core (200) inserted in an outer core inserted in an outer core at a certain interval between itself and a round inner circumferential surface formed by inner surface of the unit laminated assemblies, so that components can be easily assembled, the number of assembling processes and the number of components can be reduced.
Full Text Description
STATOR OF RECIPROCATING MOTOR
Technical Field
The present invention relates to a reciprocating motor, and particularly, to a stator
of a reciprocating motor capable of reduing the number of components and the
number of assembling processes and also reduing dimensional errors of components
in assembling.
Background Art
A motor converts electric energy into kinetic energy. The motor is classified into a
rotating motor that coverts electric energy to a rotational movement force and a re-
ciprocating motor that converts electric energy to a linear movement force.
Figures 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 coil 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 coil 400 is made sirh
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, re-
spectively.
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.
Figure 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 (LI) 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 (LI) 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 (LI)
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 de-
teriorating its productivity.
Figure 4 illustrates another embodiment of the stator.
As shown therein, the outer core of the stator is made sich 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 (LUI).
An inner surface and an outer surface of the unit laminated assembly (LUI) are
formed curved by a plurality of lamination sheets 12. The inner surfaces of the unit
laminated assemblies (LUI) 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 cover 413 for covering the winding
groove of the ring-shaped body 412. The winding coil 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.
US 2002 / 105247 Al shows a stator of a reciprocating motor comprising an outer and an
inner stator structure. The outer structure is composed of a winding coil and a plurality of units of
laminated assemblies coupled to the bobbin of the winding coil in the circumferential direction.

JP 2001-352737 A describes a stator of a reciprocating motor comprising an outer and an
inner structure, only the outer stator structure is turned implemented around 90° in relation to the
outer stator structure.
WO 02/087059 Al describes a further stator of a reciprocating motor including an outer and
an inner stator structure. The outer stator structure is composed of a ring coil and a plurality of U-
shaped core laminates coupled to the bobbin of the coil in the circumferential direction.
US 3,774,059 A shows a rotating stepping motor with an outer stator comprising a ring coil
and U-shaped laminated cores arranged along this ring coil in the circumferential direction like the
configuration of the outer stator.
Disclosure
It is an object of the present invention to provide a stator of a reciprocating motor capable of
reducing the number of components and the number of assembling processes, which are not taught
by the aforesaid prior art references.
It is another object of the present invention to provide a stator of a reciprocating motor
capable of reducing a dimensional error of a component in assembling and simplifying assembling
operation.

To achieve the above object, there is provided a stator of a reciprocating motor comprising : a
bobbin formed in a ring shape and providing a winding coil therein, the bobbin having a covering
portion defining an outer circumferential surface of the bobbin for covering the winding coil in the
bobbin; a plurality of unit laminated assemblies each constructed of a plurality of lamination sheets
and coupled to the bobbin in a circumferential direction; two partially-fixing portions adjacent to
each other, and extending from the covering portion to cover lateral sidewalls and a part of the outer
circumferential surface of each of the unit laminated assemblies therebetween; and an inner core
inserted in an outer core at a certain interval between itself and a round inner circumferential surface
formed by inner surfaces of the unit laminated assemblies.
Description of the Accompanying Drawings
Figures 1, 2 are a sectional view and a front view showing a general reciprocating

motor, respectively;
Figure 3 is a perspective view showing a disassembled stator of a reciprocating
motor in accordance with one embodiment of the conventional art;
Figure 4 is a front view showing a stator of a reciprocating motor in accordance
with another embodiment of the conventional art;
Figures 5,6 are a sectional view and a front view showing a reciprocating motor
having stator in accordance with one embodiment of the present invention;
Figure 7 is a perspective view showing partially cutout stator of the reciprocating
motor;
Figure 8 is a perspective view showing a partially cutout stator of a reciprocating
motor in accordance with another embodiment of the present invention; and
Figures 9, 10 are plane views respectively showing a part-fixing portion con-
stituting a stator of the reciprocating motor.
Mode for Invention
Hereinafter, a stator of a reciprocating motor in accordance with the present
invention will now be described in detail with reference to embodiments shown in ac
companying drawings.
Figures 5, 6 are a sectional view and a front view showing a reciprocating motor
having a stator in accordance with one embodiment of the present invention, and
Figure 7 is a perspective view showing a partially cutout stator of the reciprocating
motor. The same reference numerals are given to the same parts as the conventional
art.
As shown therein, the reciprocating motor includes a ring-shaped bobbin 500
providing a winding coil 400 therein; a plurality of unit laminated assemblies (LU2)
each constructed by stacking a plurality of lamination sheets and coupled to the bobbin
500 in a circumferential direction; a fixing means integrally formed with the bobbin
500 and fixing the unit lamination sheets (LU2) to the bobbin 500; an inner core 200
inserted in an outer core at a certain interval between itself and a round inner circum-
ferential surface formed by inner surfaces of the unit laminated assembly (LU2); and a
mover 300 movably inserted between the unit laminated assembly (LU2) and the inner
core 200.
The unit laminated assembly (LU2) is constricted of two half-unit laminated
assemblies 600 which are formed to be symmetric to each other on the reference to a
horizontal direction (circumferential direction) of the bobbin 500. Preferably, the

the same shape.
The unit laminated assembly (LU2) may not be separated in two but be formed
integrally, and may be implemented variously in shape.
A lamination sheet constricting the half-unit laminated assembly 600 includes a
half pass portion 610 having a certain width and a certain length; a side pass portion
620 formed extended from the half pass portion 610, bent at a right angle; and a pole
portion 630, an end portion of the side pass portion 620.
The shape of the pole portion 630, an end portion of the side pass portion 620, may
be implemented variously in shape.
The half-unit laminated assemblies 600 are positioned at the bobbin 500 with end
portions of the half pass portions 610 contacted to each other, and the two half-unit
laminated assemblies 600 construct one unit laminated assembly (LU2).
The bobbin 500 includes a ring-shaped body portion 510 having a ring-shaped
winding groove 511 in which a winding coil is positioned; a covering portion 520 for
covering the winding groove 511 of the ring-shaped body portion; and a totally-fixing
portion 530 formed extended from the covering portion 520 and for fixing the unit
laminated assembly (LU2) to the bobbin by covering an entire outer surface of the unit
laminated assembly (LU2).
The totally-fixing portion 530 of the bobbin is the fixing means.
The bobbin 500 is made of a molding material having an insulating property.
The winding coil 400 is made as a wire is wound plural times around the ring-
shaped body portion 510 of the bobbin.
The covering portion 520 is formed in a ring shape with a certain thickness and a
certain width, and the width of the covering portion 520 is formed to be the same as
that of the ring-shaped body portion 510.
The unit laminated assembly (LU2) is formed as two separated half-unit laminated
assemblies 600 are coupled to the bobbin 500 so that ends of the half pass portions 610
of the half-unit lamination assemblies are contacted to each other. Then, an inner side
of the half pass portion 610 of the laminated assembly 600 comes in contact with the
covering portion 520 of the bobbin 500, and an inner side of the side pass portion 620
comes in contact with a side surface of the ring-shaped body portion 510 of the bobbin.
That is, the unit laminated assembly (LU2) is coupled to the bobbin, making the
lamination sheets (L3) constricting the unit laminated assembly (LU2) face the center
of the bobbin.
The totally-fixing portion 530 of the bobbin has a certain thickness and is formed in

a band shape a width of which is the same as that of the covering portion 520. The
totally-fixing portion 530 covers a portion where two half-unit laminated assemblies
600 constructing the unit laminated assembly (LU2) (a half pass portion of the
laminated sheet) are in contact with each other. At this time, both surfaces and outer
surface of the unit laminated assembly (LU2) are adhered to the totally-fixing portion
530, and the totally-fixing portion 530 is protruded.
A plurality of discharge openings 540 through which moisture is discharged is
formed at the ring-shaped body portion 510 of the bobbin.
The plurality of unit laminated assemblies (LU2) is fixedly coupled to the bobbin
500 by totally-fixing portions 530, respectively.
Figure 8 illustrates another embodiment of the fixing means. The same reference
numerals are given to the same part as in the above embodiment.
As shown therein, the fixing means is formed extended from a covering portion 520
of the bobbin 500 and includes a partially fixing portion 550 for fixing the unit
laminated assembly (LU2) to the bobbin by covering parts of both sides of the unit
laminated assembly (LU2).
The partially-fixing portions 550 for respectively fixing both sides of the unit
laminated assembly (LU2) to the bobbin are formed in the same shape.
The partially-fixing portion 550 has a certain thickness and a certain width, and its
width is the same as that of the covering portion 520 of the bobbin.
The partially-fixing portion 550 covers one side surface of the unit laminated
assembly (LU2) and a part of its outer circumferential surface. And an inner surface of
the partially-fixing portion 550 is adhered to one side surface of the unit laminated
assembly (LU2) and its outer ciraimferential surface. The partially-fixing portion 550
is protruded from the unit laminated assembly (LU2).
Preferably, the partially-fixing portion 550 covers 1/3 of an outer surface of the unit
laminated assembly (LU2).
In addition, as shown in Figure 9, ends of partially-fixing portions 550 that fix both
sides of the unit laminated assembly (LU2) are formed to be straight.
As a different modified example of the partially-fixing portion, as shown in Figure
10, ends of partially-fixing portions 550 that fix both sides of the unit laminated
assembly (LU2) are formed to be curved, and the curved lines of the two partially-
fixing portions 550 are formed to be symmetric to each other.
The bobbin 500 provided with the partially-fixing portion 550 is made of a molding
material having an insulating property.

If the partially-fixing portion 550 is formed by over-molding, its deformation due to
a constriction caused by cooling can be prevented, which may occur in the totally-
fixing portion 530.
The inner core 200 is formed in a cylindrical shape having a certain width. The
inner core 200 is a laminated assembly constructed of a plurality of quadrangular
shaped lamination sheets having a certain width and a certain length.
One example of a method for fabricating a stator of a reciprocating motor as above
will now be described.
First of all, a plurality of unit laminated assemblies (LU2) is coupled to a bobbin
500 in which a winding coil 400 is positioned. At this time, a totally-fixing portion 530
or a partially-fixing portion 550 have not been made at the bobbin yet. The unit
laminated assembly (LU2) is constructed of two half-unit laminated assemblies 600,
and the two half-unit laminated assemblies 600 are coupled to the bobbin 500 so as to
be in contact with each other. Inner surfaces of the lamination sheets (L3) constricting
the laminated assembly 600 come in contact with the covering portion 520 of the
bobbin, and inner surfaces of the side pass portions 620 of the lamination sheets come
in contact with a side surface of the bobbin 500. The inner surfaces of the unit
laminated assemblies (LU2) coupled to the bobbin 500 form an inner circumferential
surface of a cylindrical shape.
A molding material having art insulating property is over-molded on the bobbin and
the plurality of unit laminated assemblies. The totally-fixing portion, the fixing means,
means the molding material particularly covering the unit laminated assembly
When partially-fixing portions 550, the fixing means, are formed, a molding
material is over-molded only on a part of both sides of the unit laminated assembly
(LU2).
Then, the molding material is cooled.
Hereinafter, operational effect of a stator of a reciprocating motor in accordance
with the present invention will now be described.
In the stator of the reciprocating motor in accordance with the present invention, a
plurality of unit laminated assemblies (LU2) coupled to the bobbin 500 is fixedly
coupled to the bobbin 500 by extendedly forming one side of the bobbin 500. Ac-
cordingly the number of components is relatively reduced, and an assembly process is
simplified.
That is, in the conventional art, ring grooves 150 are formed at each unit laminated
assembly (LU2), and a round-shaped fixing ring 140 is inserted in the ring groove 150

by compressing the fixing ring 140. Therefore, a dimension of the ring groove 150 and
that of the fixing ring 140 must be made so as to fit to each other, thereby making
fabrication complicated and requiring relatively many components. However, in the
present invention, there is no need for a ring groove 150 of a unit laminated assembly
(LU2) and a fixing ring 140.
In addition, in the present invention, deformation of a dimension of a unit laminated
assembly (LU2) constructed of a plurality of lamination sheets (L3) is minimized, so
that a gap between the outer core and the inner core, in which a mover 300 is inserted,
is constantly maintained.
Especially, since the present invention has a structure which can be produced by an
over-molding, when a plurality of unit laminated assemblies (LU2) is fixed to the
bobbin by an over-molding, an assembling time is shortened and the number of
assembling processes is reduced.
As so far described, in a stator of a reciprocating motor in accordance with the
present invention is produced, components are easily assembled, and the number of
assembling processes and the number of components are relatively reduced, thereby
improving assembling productivity, reducing fabrication cost, and thus strengthening
the competitiveness of the product.
Also, in the present invention, since a dimensional error of a component is reduced
in assembling, thereby improving reliability of a product.
It will be apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing from the spirit or
scope of the invention. Thus, it is intended that the present invention cover modi-
fications and variations of this invention provided they come within the scope of the
appended claims and their equivalents.

WE CLAIM :
1. A stator of a reciprocating motor comprising:
a bobbin formed in a ring shape and providing a winding coil therein, the bobbin having a
covering portion defining an outer circumferential surface of the bobbin for covering the winding coil
in the bobbin;
a plurality of unit laminated assemblies each constructed of a plurality of lamination sheets
and coupled to the bobbin in a circumferential direction;
two partially-fixing portions adjacent to each other, and extending from the covering portion
to cover lateral sidewalls and a part of the outer circumferential surface of each of the unit laminated
assemblies therebetween; and
an inner core inserted in an outer core at a certain interval between itself and a round inner
circumferential surface formed by inner surfaces of the unit laminated assemblies.
2. The stator as claimed in claim 1, wherein the unit laminated assembly comprises two half-unit
laminated assemblies symmetric to each other on the reference to a horizontal direction of the
bobbin.
3. The stator as claimed in claim 2, wherein the lamination sheet for constructing the half-unit
laminated assembly comprises :
a half pass portion having a certain width and a certain length;
a side pass portion formed extended from the half pass portion, bent at a right angle; and
a pole portion, an end portion of the side pass portion.

4. The stator as claimed in claim 1, wherein the partially-fixing portions for respectively fixing
both sides of the unit laminated assembly are the same in shape.
5. The stator as claimed in claim 1, wherein the partially-fixing portion covers 1/3 of an outer
surface of the unit laminated assembly.
6. The stator as claimed in claim 1, wherein ends of the partially-fixing portions for respectively
fixing both sides of the unit laminated assembly are straight.
7. The stator as claimed in claim 1, wherein ends of the partially-fixing portions for respectively
fixing both sides of the unit laminated assembly are curved.
8. The stator as claimed in claim 7, wherein the curved lines of the partially-fixing portions
respectively positioned at both sides of the unit laminated assembly are symmetric to each other.
9. The stator as claimed in claim 1, wherein widths of the partially-fixing portions respectively
positioned at both sides of the unit laminated assembly are the same as that of the covering portion.
10. The stator as claimed in claim 1, wherein the bobbin is made of a molding material having an
insulating property.

11. The stator as claimed in claim 1, wherein the partially-fixing portion is protruded with a
certain thickness from an outer circumferential surface of the unit laminated assembly.
12. The stator as claimed in claim 1, wherein a plurality of discharge openings through which
moisture is discharged is formed at one side of the bobbin.

A stator of a reciprocating motor has a ring shaped bobbin (500) having a winding coil (400)
therein; a plurality of unit laminated assemblies (LU2) each constructed of a plurality of lamination
sheets and coupled to the bobbin in a circumferential direction; a fixing means integrally formed with
the bobbin (500) and for fixing the unit laminated assemblies to the bobbin (500); and an inner core
(200) inserted in an outer core inserted in an outer core at a certain interval between itself and a
round inner circumferential surface formed by inner surface of the unit laminated assemblies, so that
components can be easily assembled, the number of assembling processes and the number of
components can be reduced.

Documents:

1772-KOLNP-2005-FORM-27.pdf

1772-kolnp-2005-granted-abstract.pdf

1772-kolnp-2005-granted-assignment.pdf

1772-kolnp-2005-granted-claims.pdf

1772-kolnp-2005-granted-correspondence.pdf

1772-kolnp-2005-granted-description (complete).pdf

1772-kolnp-2005-granted-drawings.pdf

1772-kolnp-2005-granted-examination report.pdf

1772-kolnp-2005-granted-form 1.pdf

1772-kolnp-2005-granted-form 18.pdf

1772-kolnp-2005-granted-form 3.pdf

1772-kolnp-2005-granted-form 5.pdf

1772-kolnp-2005-granted-gpa.pdf

1772-kolnp-2005-granted-reply to examination report.pdf

1772-kolnp-2005-granted-specification.pdf


Patent Number 227782
Indian Patent Application Number 1772/KOLNP/2005
PG Journal Number 04/2009
Publication Date 23-Jan-2009
Grant Date 20-Jan-2009
Date of Filing 06-Sep-2005
Name of Patentee LG ELECTRONICS INC.
Applicant Address 20, YOIDA-DONG, YOUNGDUNGPO-GU, SEOUL
Inventors:
# Inventor's Name Inventor's Address
1 YOON WON-KI 28/5, 766-2, YEONSAN 4-DONG, YEONJE-GU, BUSAN 611-823
2 JUNG WON-HYUN SUNGWON 1-CHA APT. 106-404, NAMYANG-DONG, CHANGWON, GYEONGSANGNAM-DO 641-751
PCT International Classification Number H02K
PCT International Application Number PCT/KR2004/000505
PCT International Filing date 2004-03-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10-2003-0015208 2003-03-11 Republic of Korea