JP3164796B2 - Linear compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor having a linear motor for refrigeration in a temperature range in which a high-temperature superconductivity phenomenon is observed (nitrogen temperature: about 80 ° K). The present invention relates to a linear compressor having improved heat dissipation and improved assembly accuracy.

[0002]

2. Description of the Related Art FIG. 6A shows a typical linear compressor as a prior art. The entire device is configured to be covered by a pressure vessel 6, and when a current flows through the coil 1, an electromagnetic force acts between the coil 1 and the magnet 7 to drive the piston 3. Since the plurality of magnets are combined so that the magnetic directions are the same, the piston reciprocates in the axial direction by passing an alternating current. The piston 6 performs an operation of compressing the working gas together with the cylinder 4, and the piston itself is supported by the leaf spring 5. As a problem of the prior art, as shown in FIG. 6A, heat dissipation is poor because a coil as a heating member is inside, and durability is low because a lead wire is connected to a movable portion. In addition, the movable part is cantilevered, and is structurally weak against bending and twisting due to assembly and driving.

There is also a problem that the accuracy of parts and the skill of assembly are required to maintain the assembly accuracy.

As another prior art, a moving magnet type linear motor is disclosed in Japanese Patent Application Laid-Open No. Hei 6-189518. The disclosed technology has a large stroke length and improved heat dissipation. However, this technique has a special configuration of a spindle (piston), and is not a structure supported by a leaf spring. The yoke has a balanced cantilever structure and a movable portion is heavy. Cannot be applied as is.

Therefore, the present inventors provide an improved linear compressor which can be used as a compressor of a refrigerator.

[0006]

An actuator which is driven by an electromagnetic force constituting a linear compressor generates a force by applying a current to a coil. However, the actuator generates heat by Joule heat based on the current, and the temperature around the coil becomes high. Becomes Since the high-temperature portion exists inside the actuator, it is difficult to radiate heat, and the compressor itself becomes high in temperature. Insufficient heat radiation and a high temperature of the device may cause damage to the machine, deterioration of the magnet, etc., leading to lower performance of the actuator and the compressor.

When the linear compressor is operated, the temperature around the piston and cylinder becomes high due to the heat of gas compression.

Further, when assembling the linear compressor, in addition to the above-mentioned measures against heat generation around the coil portion and around the piston / cylinder, the problem of assembly accuracy cannot be ignored. In the linear compressor of the present invention, the gap between the piston and the cylinder is only a few microns, and the accuracy of the movable part including the piston is required when considering the thermal expansion, bending and twisting, and the side force due to the attractive force of the magnet. Needless to explain.

If the movable portion has a cantilever structure, the weight causes the movable portion to be displaced due to bending or the like, and it becomes difficult to perform precise assembly. Despite the demand for assembly accuracy from smooth driving conditions, the positioning of the leaf spring and the movable part,
Positioning becomes difficult. In addition, this linear compressor has a structure in which displacement is easily generated with respect to torsional force and moment force during driving, in addition to the problem of assembly accuracy.

When assembling a linear compressor, when the number of parts is large and the number of connection parts is large, the overlapping of mechanical tolerances (especially in a configuration in which the components are sequentially assembled from one side) causes
It becomes difficult to assemble movable parts that require high accuracy. Therefore, minimizing the number of parts required for such assembling is an effective measure for assembling accuracy.
In addition, since the linear compressor has a structure in which the piston is held by a number of leaf springs, it is not easy to assemble the piston and the cylinder, which is required to have an accuracy of several μm due to the processing accuracy of the leaf spring and the like. . Deformation force (stress) is easily applied to the leaf spring at the time of assembling the piston, there is little adjustment allowance for positioning in the piston part, the number of leaf springs is large, and it is difficult to position and assemble the leaf spring.
It has been pointed out that the displacement affects the spring constant.

[0011]

As means for improving heat dissipation, a coil housed in a movable part in the prior art is formed in a housing of an actuator, and a magnet fixed to the housing is moved to the movable part to generate heat. Place the body coil near the outer surface. Further, the housing of the actuator is connected to the housing member of the compressor (pressure vessel).
And the actuator itself has a structure having a heat radiation function. Further, a heat dissipating member such as a fin is formed on the housing to further enhance the heat dissipating property. Furthermore, if necessary, the shape of the housing portion is changed, and the coil as the heat source is taken out of the pressure vessel as far as possible to further improve the heat dissipation.

Since the magnet is moved to the movable part, the structure of the movable part is simplified, and the strength of the member on which the force acts directly increases. Use a cylinder with high thermal conductivity and high mechanical strength and a thermal expansion coefficient similar to that of the piston material (for example, strong brass). Makes heat dissipation easier.

[0013] Separately, in order to improve the assembly and its accuracy, a hollow leaf spring is used to support the piston,
Adopting a moving magnet type actuator with a structure that reduces the weight of the movable part (the yoke is separated from the movable part), the movable part has a box-shaped structure, and has a structure that is strong against torsional force and moment force. The accuracy is improved so that positioning of the leaf spring portions located on both sides of the movable portion and positioning of the leaf spring portions located on both sides of the movable portion are facilitated.

Further, the plate spring portion is made into a sub-assembly, the yoke of the actuator is made to have a two-sided structure, the number of parts is reduced, the dimensional error due to the tolerance of parts is reduced, and the assembling is good and the assembling can be performed with high accuracy. To improve. It is also effective to provide a positioning member and a positioning pin on a receiving member on which the leaf spring is placed, and to have a configuration in which the piston and the leaf spring do not interfere with each other. With such a configuration that does not interfere, the piston can be directly connected to the movable portion, and the positioning and assembly can be easily performed. It can also be said that the position adjustment can be performed with both the cylinder and the piston. Even if this is viewed from the leaf springs provided on both outer sides of the piston, the positioning of the leaf spring is naturally easy. Sub-assembly of the leaf spring, which most affects the driving state, makes it possible to evaluate the characteristics of the leaf spring in the final assembled state, adjust the elastic force of the spring, and suppress variations in the characteristics of the compressor.

According to the above solution, the linear compressor according to the first aspect includes a plurality of coils fixed to the housing for inducing a magnetic field, a magnet, and a yoke for forming a magnetic path. A cylinder, a piston that reciprocates to expand and compress the working fluid, a leaf spring that adjusts the driving force and rigidity of the piston, and a compressor that includes a housing that forms a magnetic path and serves as a pressure vessel. A coil is installed on the housing member, the housing member is configured as a pressure vessel of the compressor, and the actuator itself is configured as a heat radiating section.

When the compressor operates, the coil generates a considerable amount of heat. However, in the present invention, since the coil is formed in the housing member, heat is easily generated, and the sliding resistance increases due to a dimensional change accompanying thermal expansion. Inconveniences such as a decrease in magnetic force can be avoided.

According to a second aspect of the present invention, there is provided a compressor having a heat radiation fin provided on an outer surface of a housing member to promote heat radiation from a coil and a cylinder having a high thermal conductivity and a thermal expansion coefficient substantially equal to that of a piston material. It is characterized in that the cylinder and the heat transfer member having a high thermal conductivity are brought into contact with each other to release the heat of gas compression to the outside of the machine. With this improvement,
There is the same effect as in claim 1 for preventing the compressor from becoming hot.

According to the present invention, there are provided a plurality of coil portions fixed to a housing for inducing a magnetic field, a plurality of magnets forming a movable portion, a piston for reciprocating to expand and compress a working fluid, a cylinder, A compression unit including a hollow leaf spring for adjusting the driving force and rigidity of the piston, and a housing as a pressure vessel, fixing the coil unit, moving the magnet, and configuring a movable unit. A linear compressor characterized in that the weight of the magnet, the piston, and the leaf spring is reduced and the driving frequency can be increased. As a linear compressor, a coil and a fixed part, a magnet and the arrangement of the movable part, further reduces the weight of the movable portion, allowing a high frequency of the drive frequency.

According to a third aspect of the present invention, a movable part including a hollow leaf spring and a piston has a box-shaped structure, and the piston constituting the movable part and a yoke of an actuator have a double-ended structure, and a part constituting the movable part. 2. The linear compressor according to claim 1, wherein the number of points is reduced, the leaf spring portion is formed into a sub-assembly, and a receiving member on which the leaf spring is placed is provided with a positioning receiver and a positioning pin. .

Since the movable portion has a box-shaped structure and has little displacement against torsional force and moment force, that is, is strong against external force, and the movable portion has a two-sided structure, the leaf springs located at both ends of the movable portion are located. Has an easy structure. Further, the number of parts between the piston and the movable portion is reduced, the positioning of the piston is facilitated, and the plate spring is sub-assembled, so that the assembling accuracy and the assembling property are improved. As a result, it can be said that the configuration is also capable of adjusting the position of both the cylinder and the piston and adjusting the characteristics of the leaf spring.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A linear compressor generates heat due to various causes during operation. Among these heat generations, the heat generated by the coil due to Joule heat and the heat generated by the compression of the gas around the piston / cylinder are large. Occupy part.

In the present invention, the problem of how to radiate the heat generated by the coil heat of the linear compressor and the heat generated by the gas compression, and the improvement of the function and structure of the components of the linear compressor, including measures for radiating heat, are provided. The problem is solved by the following means.

In the linear compressor according to the present invention, a coil is installed on a housing member of an actuator, the housing member is configured as a pressure vessel of the compressor, and the actuator itself is a heat radiation part. When the compressor operates, the coil generates considerable heat. However, in the present invention, the coil is formed on the housing member located at a position close to the surface of the device that easily dissipates heat. Inconveniences such as an increase in sliding resistance and a decrease in magnetic force due to dimensional changes can be avoided.

In the second aspect of the present invention, a radiating fin is provided on the outer surface of the housing member to promote heat radiation from the coil, and a cylinder having a high thermal conductivity and a thermal expansion coefficient substantially equal to that of the piston material is used. Then, the cylinder and the heat transfer member having high thermal conductivity are brought into contact with each other, so that the heat of gas compression can be easily discharged to the outside of the machine. This improvement can prevent the compressor from becoming hot.

Further, in the present invention , as the linear compressor,
Since the weight of the movable portion is reduced, the required radial rigidity of the hollow leaf spring can be reduced, and the driving frequency can be increased. When used for a refrigerator, there is an advantage that the refrigeration efficiency is increased by increasing the frequency.

Furthermore, in claim 3, twisting force to the movable portion in a box shape, both ends structure, less displaced relative moment force, there is a first feature in that a structure strong against an external force. The two-sided structure is structurally more advantageous than the cantilevered structure. Second
In addition, the box-shaped structure has an advantage that the plate springs located at both ends of the movable portion can be easily positioned. Third
In the improvement of the above, the number of parts between the piston and the movable part was reduced, so that the assembling accuracy was increased and the positioning of the piston was easy. The fourth improvement is that the structure of the plate spring can be easily adjusted by making the plate spring sub-assembly. Thus, the movable part has a box-shaped structure,
As a double-sided structure, the structure is strong against external force and can be assembled with high accuracy. Sub-assembly of the leaf spring and reduction in the number of parts between the movable portion and the piston further improve the assembly accuracy and assemblability. As a result, it is easy to adjust the position of both the cylinder and the piston and adjust the characteristics of the leaf spring.

[0027]

<Embodiment 1> A specific example of the present invention is shown in FIG. As a compressor, heat dissipation and assemblability (assembly accuracy) have been improved. First, as a means for improving the heat radiation, the coil 1 is formed in the housing 2 of the actuator, and the housing of the actuator is further configured as a housing member (pressure vessel) of the compressor, so that the actuator itself has a heat radiation function. . Since the heat source coil is disposed near the outside of the device, heat is easily dissipated. Further, a heat dissipating member such as a fin 8 may be formed on the housing, and if necessary, the shape of the housing portion may be changed so that the coil serving as a heat source is drawn out of the pressure vessel to further improve heat dissipating properties. it can. Further, when a cylinder having the same thermal expansion coefficient as the piston and having a high thermal conductivity is used, the heat radiation from the working gas is improved.

Next, from the viewpoint of assembly accuracy, FIG. 1B is a partial view showing a box-shaped structure including the piston 3, the magnet 7, and a leaf spring. Compared with FIG. 6B in the case of the cantilever yoke in which the above-described prior art coil is held inside the device, the difference between the two configurations will become apparent. In this embodiment, the two-sided box type has a structure capable of withstanding a moment force and a torsion force at the time of assembling and driving. In addition, the box type structure has the advantage that leaf springs can be attached to both ends. The positioning of the leaf spring before and after the important movable part can be easily performed. Further, FIG.
In (b), the number of components between the linear drive unit and the piston is reduced, so that workability in assembling is improved, and assembling accuracy is also improved. Further, in the case of the drawing, the adjustment allowance for positioning the piston is large, which itself has the advantage of facilitating the positioning of the piston, and the piston and the leaf spring do not interfere with each other at all. Therefore, there is also an advantage that the piston is in a state where a stress that deforms the leaf spring is not applied, and the positioning of the piston is facilitated. In addition, the coil that generates heat is removed from the movable part, and as a result of the removal of the coil, the problem of durability of the lead wire due to the movement of the lead wire is eliminated.

As described above, the compressor of the present invention has been sufficiently improved in terms of heat dissipation, and has a box-shaped structure from a cantilever to a displaceable with respect to torsional force and moment force. It can be understood that the shape is small, the assemblability is improved, and the accuracy is high. <Embodiment 2> FIG. 2 shows an embodiment in which the assembling accuracy of the present invention is improved. FIG. 2 shows an example in which the piston is shortened. By shortening the piston, there is an advantage that assembly such as centering becomes easier. In the box-shaped structure, the drive unit can be reduced in size as described above, and if it is necessary to make the compressor compact, it is possible to cope with such a design. <Embodiment 3> FIG. 3 shows an embodiment in which the heat radiation of the present invention is further improved. FIG. 3 shows a linear compressor having a configuration in which a coil is taken out of a pressure vessel to make heat radiation more advantageous. In this case, as shown in FIG. 4, the coil can be cooled by being in direct contact with air or water. If the housing 2 is provided with a slit, a cavity can be formed in the device, and the through cavity makes cooling easier. <Embodiment 4> A linear compressor according to the present invention includes a coil formed inside or outside a housing, a magnet having a box-shaped structure and serving as a movable portion, a cylinder, a piston, and a plate supporting the magnet and the piston. Although the main part is a spring and a housing as a pressure vessel, as described above, the box-shaped structure has a structural advantage that can resist torsion and bending during operation as well as during assembly. . It is also possible to reduce the weight of the movable part and improve the assembling accuracy at the time of assembling.

Further, as shown in FIG. 5, a plurality of springs are provided in a sub-assembly manner by providing a receiving member for positioning and a positioning pin, thereby improving the assembling property, and adjusting the spring constant and the like in units of sub-assembly. , And easily. Further, it is effective that the piston and the leaf spring do not interfere with each other, so that the piston can be directly connected to the movable part, and the positioning and the assembly are facilitated. It can also be said that the position adjustment can be performed with both the cylinder and the piston.

As described above, reducing the weight of the movable part can reduce the radial rigidity of the leaf spring, which is advantageous for adjusting the driving frequency and increasing the frequency, and adopting a box-shaped structure and a two-sided structure. The number of parts has been reduced to reduce dimensional errors due to component tolerances, and the structure has been improved so that assemblability is good and assembling can be performed with high accuracy.

[0032]

According to the first aspect of the present invention, a coil is provided on a housing member of an actuator, the housing member is configured as a pressure vessel (housing) of the compressor, and the actuator itself is a heat radiating portion. Heat is easily dissipated, and there is an effect that inconveniences such as an increase in sliding resistance and a decrease in magnetic force due to a dimensional change due to thermal expansion can be avoided.

In the compressor according to the present invention, a radiating fin is provided on the outer surface of the housing member to promote heat radiation from the coil, and has a high thermal conductivity and a thermal expansion coefficient substantially equal to that of the piston material. By using a cylinder and having a structure in which the cylinder and a component having a high thermal conductivity are brought into contact with each other, it is possible to prevent the compressor from becoming hot.
Further, the invention according to claim 1 or 2 is a moving magnet type actuator, a hollow leaf spring, a piston,
This is a compressor having a configuration including a cylinder, and has the effect of reducing the weight of the movable part and improving the assembling accuracy during assembling. Specifically, there is an effect of reducing the required radial rigidity of the leaf spring.

In addition, according to the invention of claim 3 , the actuator has a double-ended structure, and the movable portion including the hollow leaf spring and the piston has a box-shaped structure.
The assemblability, adjustment margin, ease of adjustment, and the like are improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a linear compressor according to an embodiment of the present invention. (A) shows the whole and (b) shows the part.

FIG. 2 is a schematic view of an embodiment of the present invention, using a short piston.

FIG. 3 is a schematic view showing an example in which a coil is installed outside a pressure vessel in the embodiment of the present invention.

FIG. 4 is a perspective view in which a slit is provided in a housing for cooling a coil according to an embodiment of the present invention, and a cavity is formed between the housing and the outside.

FIG. 5 is an external view of a leaf spring (part) according to an embodiment of the present invention.

FIG. 6 is a schematic view of a conventional linear compressor, in which (a) shows the whole and (b) shows a part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coil 2 Housing 3 Piston 4 Cylinder 5 Leaf spring 6 Pressure vessel 7 Magnet 8 Fin

(56) References JP-A-4-209978 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 35/04

Claims (3)

(57) [Claims] 1. A plurality of coils fixed to a housing for inducing a magnetic field, a plurality of magnets, a yoke for forming a magnetic path, a cylinder, and a piston for reciprocating to expand and compress a working fluid. And a leaf spring for adjusting the driving force and rigidity of the piston, and a compressor including a housing forming a magnetic path and serving as a pressure vessel, wherein a coil is installed on a housing member of an actuator, and the housing member is mounted on the compressor. A linear compressor configured as a pressure vessel, wherein the actuator itself serves as a heat radiating section. 2. A cylinder made of a material having heat radiating fins on an outer surface of a housing member to radiate heat to the outside of the machine and / or having a high thermal conductivity and a thermal expansion coefficient substantially equal to that of a piston material. 2. The linear compressor according to claim 1, wherein heat of compression of the gas is released to the outside of the machine by contacting the gas with a heat conductive member having high thermal conductivity. 3. A movable portion including a hollow leaf spring and a piston is formed in a box-shaped structure, and the piston and the yoke of the actuator are formed as a double-supported structure, thereby reducing the number of parts constituting the movable portion. 2. The linear compressor according to claim 1, wherein said leaf spring portion is formed into a sub-assembly, and a receiving member on which said leaf spring is mounted is provided with a positioning receiving pin and a positioning pin.