Linear compressor

Abstract

A linear compressor having a stator comprising a coil body for generating a magnetic field when electric current is supplied to the stator, and outer cores disposed on the coil body while surrounding the coil body such that a magnetic flux passes therethrough. The coil body is formed in the shape of a hollow cylinder. The coil body is made of wound electric wires. The coil body is provided with a form-maintaining member for maintaining the shape of the coil body, by which the outer cores are supported. An impregnant, such as varnish, is used as the form-maintaining member. The impregnant is penetrated into gaps between electric wires, and is then solidified so that the shape of the coil body is firmly maintained.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 2004-18069, filed on Mar. 17, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a linear compressor, and, more particularly, to a linear compressor having a stator for moving a moving member connected with a piston forward and backward.

2. Description of the Related Art

Generally, a compressor is used to compress a coolant and discharge the compressed coolant to the outside in a refrigerating cycle where compression, condensation, expansion, and evaporation processes are consecutively carried out with the coolant as a medium. A linear compressor is used to compress a coolant by means of a linear motor that is capable of carrying out a rectilinear movement, by which a piston is linearly reciprocated.

The conventional linear compressor serving to perform the above-mentioned functions comprises: a compressing unit for compressing a coolant in a hermetically sealed container; and a driving unit for transmitting power to the compressing unit.

The compressing unit comprises: a cylinder block having a compression chamber defined therein; and a piston disposed in the compression chamber of the cylinder block such that the piston is moved forward and backward to compress the coolant. To one side of the cylinder block is attached a cylinder head having an inlet chamber and outlet chamber defined therein.

The driving unit comprises: a stator for generating a magnetic field when electric current is supplied to the stator; an inner core disposed while being spaced a prescribed distance from the stator for generating a magnetic flux together with the stator; and a moving member disposed between the stator and the inner core for driving the piston.

The stator of the conventional compressor will hereinafter be described in more detail. The stator comprises: a cylindrical bobbin; and a coil wound on the outer circumference of the bobbin. On the bobbin are mounted outer cores in the circumferential direction of the bobbin.

The bobbin is provided at the top and bottom parts thereof with core mounting grooves, into which the outer cores are engaged so that the outer cores are fixedly attached to the bobbin.

In the conventional linear compressor with the above-stated construction, there is generated a magnetic field at the outer cores when electric current is supplied to the coil. The moving member is linearly moved by means of magnetic interaction between the magnetic field and the moving member. At the same time, the piston connected to the moving member is reciprocated in the compression chamber so that the coolant is compressed.

In the stator of the conventional compressor, however, the outer cores are mounted on the bobbin. As a result, the outer cores may deviate from their originally mounted positions when the bobbin is deformed due to heat generated during operation of the compressor.

Consequently, gaps between the moving member and the outer cores may not be constantly maintained, whereby the entire efficiency of the linear motor is decreased.

Furthermore, the compressor may be damaged when the moving member directly collides with the outer cores.

SUMMARY OF THE INVENTION

Therefore, it is an aspect of the invention to provide a linear compressor that is capable of preventing deformation of a stator due to heat generated when the compressor is operated.

In accordance with an aspect, the present invention provides a linear compressor comprising: a piston reciprocated in a cylinder for compressing a coolant; a moving member reciprocated along with the piston; and a stator electro-magnetically interacting with the moving member for driving the moving member, wherein the stator comprises: a coil body formed of wound electric wires; a core disposed on the coil body; and a form-maintaining member for maintaining the shape of the coil body so that the core is supported by means of the coil body.

Preferably, the form-maintaining member is an impregnant penetrated between the electric wires forming the coil body.

Preferably, the coil body and the core are fixedly attached to each other with an injection-molded member filled between the coil body and the core by means of injection molding.

Preferably, the coil body is formed in the shape of a hollow cylinder, the core comprises a plurality of cores spaced apart from each other along the outer circumference of the coil body, and the injection-molded member is filled between the cores.

Preferably, each of the cores is provided at the side thereof opposite to the moving member with a pair of teeth parts, the injection-molded member being filled in a separated space defined between the teeth parts.

Preferably, the injection-molded member is formed of a resin material.

Preferably, the compressor further comprises a protection member disposed between the core body and the coil for protecting the coil body.

Preferably, the protection member is made of paper.

BRIEF DESCRIPTION OF THE DRAWINGS

The above aspects, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which:

FIG. 1 is a sectional view of a linear compressor according to the present invention;

FIG. 2 is a perspective view illustrating a coil body of the linear compressor according to the present invention;

FIG. 3 is a sectional view illustrating the coil body of the linear compressor according to the present invention;

FIG. 4 is an exploded perspective view illustrating how to combine cores with the coil body of the linear compressor according to the present invention;

FIG. 5 is a perspective view illustrating combination of the cores and the coil body of the linear compressor according to the present invention by means of an injection-molded member; and

FIG. 6 is a sectional view illustrating a protection member disposed between each core and the coil body of the linear compressor according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of a linear compressor according to the present invention.

Referring to FIG. 1, the linear compressor according to the present invention comprises: a compressing unit 20 for compressing a coolant in a hermetically sealed container 10; and a driving unit 30 for driving the compressing unit 20.

The compressing unit 20 comprises: a cylinder block 21 having a compression chamber 21a defined therein; and a piston 22 disposed in the compression chamber 21a of the cylinder block 21 such that the piston 22 is moved forward and backward. To the bottom part of the cylinder block 21 is attached a cylinder head 23 having an inlet chamber (not shown) and outlet chamber (not shown) defined therein.

The driving unit 30 comprises: an inner core 31 disposed at the outside of the cylinder block 21; a stator 40 surrounding the inner core 31 while being spaced a prescribed distance from the outer circumference of the inner core for generating a magnetic field; and a moving member 50 having a magnet 51 disposed such that the moving member is vertically reciprocated by means of a magnetic flux between the inner core 31 and the stator 40. Preferably, the driving unit 30 is a linear motor.

The stator 40 according to the present invention comprises: a coil body 41 for generating a magnetic field when electric current is supplied to the stator 40; and outer cores 42 disposed on the coil body while surrounding the coil body 41 such that a magnetic flux passes therethrough.

Referring to FIG. 2, the coil body 41 is formed in the shape of a hollow cylinder. The coil body 41 is made of wound electric wires 41a. The coil body 41 is provided with a form-maintaining member 41b for maintaining the shape of the coil body 41, as shown in FIG. 3, by which the outer cores 42 are supported.

An impregnant, such as varnish, may be used as the form-maintaining member 41b. The impregnant is penetrated into gaps between electric wires 41a, and is then solidified so that the shape of the coil body 41 is firmly maintained. The varnish is a type of paint, which is made of a natural or synthetic resin dissolved in a solvent. The varnish forms a transparent lustrous film.

Along the outer circumference of the impregnated coil body 41 are disposed a plurality of outer cores 42, spaced apart from each other as shown in FIG. 4. Each outer core 42 comprises an upper outer core part 42a and a lower outer core part 42b. To the coil body are attached the outer core parts 42a and 42b in correspondence to each other. The outer core parts 42a and 42b are provided at the sides thereof opposite to the moving member 50 with teeth parts 42c and 42d, respectively, by which the areas of the outer cores 42 electro-magnetically interacting with the moving member 50 are increased with the result that the stroke of the piston 22 is effectively increased.

As shown in FIG. 5, the coil body 41 and the outer cores 42 are fixedly attached to each other with an injection-molded member 43, which is filled between the coil body 41 and the outer cores 42 by means of injection molding. The injection-molded member 43 is made of a resin material. The injection-molded member 43 is filled between the outer cores 42 and in separated spaces defined between the teeth parts 42c and 42d of the outer cores 42 so that the outer cores are securely attached to the coil body 41.

Referring to FIG. 6, the stator 40 according to the present invention further comprises a protection member 44 disposed between the coil body 41 and each outer core 42 for surrounding the coil body 41 so that damage to the coil body is prevented. Preferably, the protection member 44 may be a thin paper, by which a magnetic flux smoothly flows between the coil body 41 and the outer core 42.

Now, the operation and effect of the linear compressor with the above-stated construction according to the present invention will be described.

When electric current is supplied to the coil body 41 made of wounded electric wires 41a, there is generated a magnetic field. The magnetic field interacts with a magnetic filed generated by means of the magnet 51 mounted in the moving member 50 so that the piston 22 is vertically reciprocated. As the piston 22 is reciprocated, the coolant is introduced, compressed, and discharged.

At this time, the coil body 41 and the outer cores 42 are securely attached to each other with the injection-molded member 43 made of a resin material and formed by means of injection molding. Consequently, shake or separation of the outer cores 42 from the coil body 41 due to the vibration generated during the operation of the compressor is prevented.

In the stator 40 according to the present invention, the outer cores 42 are directly attached to the coil body without an additional bobbin. Consequently, deformation of the stator 40 due to heat generated during the operation of the compressor is prevented.

As apparent from the above description, the present invention provides a linear compressor wherein outer cores are directly attached to a coil body without an additional bobbin, the outer cores being securely fixed to the coil body with an injection-molded member formed by means of injection molding.

Consequently, deformation of a stator due to heat generated during the operation of the compressor is prevented, whereby gaps between a moving member and the outer cores are constantly maintained. As a result, initial gaps between the moving member and the outer cores are set to the minimum, whereby the efficiency of a linear motor is improved.

Furthermore, the linear compressor according to the present invention requires no bobbin, whereby the number of winding electric wires, which form the coil body, is increased. Consequently, output of the linear motor is increased, the manufacturing process is simplified, and the manufacturing cost is reduced.

Although the preferred embodiment of the invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A linear compressor comprising: a piston reciprocated in a cylinder for compressing a coolant; a moving member reciprocated along with the piston; and a stator electro-magnetically interacting with the moving member for driving the moving member, wherein the stator comprises:

a coil body formed of wound electric wires;

a core disposed on the coil body; and

a form-maintaining member for maintaining the shape of the coil body so that the core is supported by means of the coil body.

2. The compressor according to claim 1, wherein the form-maintaining member is an impregnant penetrated between the electric wires forming the coil body.

3. The compressor according to claim 1, wherein the coil body and the core are fixedly attached to each other with an injection-molded member filled between the coil body and the core by means of injection molding.

4. The compressor according to claim 3, wherein the coil body is formed in the shape of a hollow cylinder, the core comprises a plurality of cores spaced apart from each other along the outer circumference of the coil body, and the injection-molded member is filled between the cores.

5. The compressor according to claim 4, wherein each of the cores is provided at the side thereof opposite to the moving member with a pair of teeth parts, the injection-molded member being filled in a separated space defined between the teeth parts.

6. The compressor according to claim 3, wherein the injection-molded member is formed of a resin material.

7. The compressor according to claim 1, further comprising a protection member disposed between the core body and the coil for protecting the coil body.

8. The compressor according to claim 7, wherein the protection member is made of paper.