JP2003097426A - Linear compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear compressor capable of suppressing the leakage of refrigerant gas from a clearance between a piston and a cylinder using a seal member even under oilless conditions, and to realize high efficiency and high reliability. SOLUTION: A channel 4c having a recessed shape is formed in the circumferential direction in the tip of the piston 4 on a compression chamber 8 side, the seal member 10 is arranged in the channel 4c having the recessed shape, and the seal member 10 is curved and extended onto the compression chamber 8 side to perform sealing in the channel 4c and on the wall face of the cylinder 3. Gas pressure in the compression chamber acts on the seal member to press the seal member in the axial direction of the channel 4c arranged in the tip of the piston 4 and in the radial direction of the cylinder wall face by this configuration. Consequently, the leakage of refrigerant into a sealed vessel 1 from the compression chamber 8 is prevented. In particular, a sufficient seal length in the radial direction can be obtained by curving and extending the seal member 10 when compared with a conventional ringlike seal member, thereby improving seal performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear compressor that reciprocates a piston incorporated in a cylinder by a linear motor to suck and discharge gas.

[0002]

2. Description of the Related Art In a refrigerating cycle, an HCFC refrigerant represented by R22 is said to destroy the ozone layer due to its stable physical properties. In recent years, HCFC
An HFC-based refrigerant is used as an alternative refrigerant to the system-based refrigerant, and this HFC-based refrigerant has a property of promoting a warming phenomenon. Therefore, recently, HC-based refrigerants that do not significantly affect the ozone layer destruction and the warming phenomenon have begun to be adopted. However, since this HC-based refrigerant is flammable, it is necessary to prevent explosion and ignition from the viewpoint of ensuring safety, and for this reason, it is required to minimize the amount of the refrigerant used. On the other hand, the HC refrigerant has no lubricity as a refrigerant itself and has a property of easily dissolving in a lubricant.

From the above, when using the HC refrigerant, an oilless or oil poor type compressor is required. Linear compressors that have a small load acting in the direction orthogonal to the axis of the piston and a small sliding surface pressure are reciprocating compressors, rotary compressors that have been used more frequently than before.
It is known as a type of compressor that is easier to achieve oilless than a scroll compressor.

[0004]

However, there is a problem that if the oilless structure is used, the sealing property is disadvantageous and the compression efficiency is lowered. In addition, the piston may collide with the valve plate due to a sudden change in pressure due to control on the system side,
It was necessary to avoid this.

In view of the above circumstances, the present invention provides a linear compressor having high efficiency and high reliability, which prevents the refrigerant gas from leaking from the gap between the piston and the cylinder by the seal member even under the oilless condition. The purpose is to provide.

Another object of the present invention is to provide a linear compressor having high reliability by mitigating the impact force even when the piston tip and the valve plate collide with each other due to a sudden change in pressure on the system side.

[0007]

According to a first aspect of the present invention, there is provided a cylinder supported by a support mechanism in a closed container, and the cylinder is slidably supported along the axial direction thereof. A piston, a head cover portion, a compression chamber provided between the piston and the head cover portion, a spring member that applies a force in the axial direction to the piston, and a connection mechanism that connects the piston and the spring member. A linear compressor having a linear motor portion having a fixed portion fixed to the cylinder and a movable portion coupled to the piston, wherein the linear compressor is circumferentially arranged at the piston tip portion on the compression chamber side. A concave groove is formed, a seal member is disposed in the concave groove, the seal member is curvedly extended toward the compression chamber, and sealing is performed between the concave groove and the wall surface of the cylinder. There, this configuration, the gas pressure in the compression chamber acts on the sealing member, the sealing member is pressed in the radial direction of the axial direction and the cylinder wall of concave grooves which are disposed in the piston tip. Therefore, the leakage of the refrigerant from the compression chamber into the closed container is prevented. In particular, by extending the seal member in a curved manner, the seal length in the radial direction can be taken as compared with the conventional ring-shaped seal member, and the sealing performance can be improved.

A linear compressor according to a second embodiment of the present invention is the linear compressor according to the first aspect of the present invention, further comprising the seal member sandwiched between the piston end surface and the end plate and supported. As a result, the seal member is sandwiched and supported by the separate end plates, so that a large sealing area can be secured in the axial direction, so that the sealing performance can be further improved.

A linear compressor according to a third embodiment of the present invention is the linear compressor according to the second aspect of the present invention, wherein the piston end surface or the end plate surface has a convex shape, and the protruding height of the convex shape is used. The space for sandwiching the seal member is adjusted. As a result, if the sandwiching space is too wide, the seal member rattles, increasing the leakage of the refrigerant gas. Further, if the sandwiching space is too narrow, the seal member is fixed to the rigid, and even if the gas pressure acts, it becomes difficult for the seal member to evenly contact the seal surface, which may promote refrigerant leakage. Therefore, by securing an appropriate sandwiching space by the end plate and the seal member, it is possible to obtain the effect of suppressing variations in the sealing performance.

A linear compressor according to a fourth embodiment of the present invention is the invention according to claim 1, 2 or 3, wherein a step is provided on the outer peripheral surface of the piston. As a result, the sliding area where the piston outer peripheral surface and the cylinder inner peripheral surface are in contact with each other is reduced, so that sliding loss is reduced. On the other hand, the increase in leakage due to the shortened seal length can be prevented by the seal member having high sealing performance, resulting in higher efficiency.

A linear compressor according to a fifth embodiment of the present invention is the linear compressor according to claim 2, 3 or 4, wherein an elastic member is sandwiched between the piston end surface and the end plate. Is. As a result, even if there is a possibility of collision between the piston tip and the valve plate, such as when the pressure in the compression chamber suddenly changes, the impact force is mitigated by the elastic member, and high reliability can be ensured. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the linear compressor of the present invention will be described below with reference to the drawings.

[0013]

First Embodiment FIG. 1 is a sectional view showing the overall configuration of a linear compressor according to a first embodiment of the present invention.

First, the overall structure of the linear compressor in this embodiment will be described with reference to FIG. This linear compressor
Generally, the cylinder 3 is supported by the support mechanism 2 in the closed container 1, the piston 4 is slidably supported by the cylinder 3 along the axial direction thereof, and the spring that contributes to the piston 4 in the axial direction. A linear motor part 6 having a member 5, a fixed part 6a fixed to the cylinder 3 side, and a movable part 6b reciprocally supported in a reciprocating path formed in the fixed part 6a, and a linear motor part 6 connected to the piston 4. A connecting rod 7a, which is one of the connecting mechanism portions 7, and a head cover portion 9 having a suction valve and a discharge valve for letting the refrigerant into and out of the compression chamber 8 side of the cylinder 3. One end of the connecting rod 7a is connected to the spring member 5, and the movable portion 6b is also connected to the spring member 5.

The closed container 1 is composed of a container for containing the main constituent elements of the linear compressor, and a refrigerant is supplied to a space 1a inside the container from a suction pipe (not shown) and introduced into the suction side of the head cover 9. It Further, the compressed refrigerant is discharged outward from the head cover 9 side through a discharge pipe (not shown) connected to the closed container 1.

The support mechanism 2 comprises a spring support plate 2a fixed inside the closed container 1 and a plurality of coil springs 2b mounted on the spring support plate 2a and supporting the cylinder 3.
The coil spring 2b functions to prevent transmission vibration from the cylinder 3 to the closed container 1.

The cylinder 3 is integrally formed with a flat flange portion 3a with which the coil spring 2b abuts, and a boss portion 3b projecting from the center of the flange portion 3a toward one end side (upward in the figure). Consists of. In addition, on the inner peripheral surface of the boss portion 3b, the seal member 1 extending in a curved shape from the piston 4 toward the compression chamber 8 side.
An inner peripheral surface 3c with which 0 abuts is formed. A compression chamber 8 is provided between the head cover 9 and the tip 4b of the piston 4 which are closely connected to the flange 3a of the cylinder 3 as shown in the drawing.
Is formed.

The piston 4 has an outer peripheral surface 4a slidably supported by the inner peripheral surface 3c of the cylinder 3, and a cylindrical body forming a concave groove 4c in the circumferential direction at the tip 4b of the piston 4. The inner surface of the concave portion 4e is such that its center of gravity is located at the bottom portion 4d. Further, the seal member 10 is disposed in the concave groove 4c, the seal member 10 is curvedly extended toward the compression chamber 8 side, and the concave groove 4c and the inner peripheral surface 3 of the cylinder 3 are provided.
The configuration is such that c is used for sealing.

As shown in FIG. 1, the spring member 5 is made of a disk-shaped member in this embodiment, and has a structure that elastically deforms from the peripheral edge to the central portion when the peripheral edge is fixed.

The linear motor section 6 comprises a fixed section 6a and a movable section 6b. The fixed portion 6a includes an inner yoke 6c and an outer yoke 6d. The inner yoke 6c is formed of a cylindrical body, and is externally fixed to the boss portion 3b of the cylinder 3. A coil 11 is housed inside the inner yoke 6c and connected to a power source (not shown). On the other hand, the outer yoke 6
Reference numeral d denotes a cylindrical body that covers the inner yoke 6c, and is fixed to the collar portion 3a of the cylinder 3. The outer yoke 6d
A reciprocating path of a minute space is formed between the inner peripheral surface of the inner peripheral surface of the inner yoke 6c and the outer peripheral surface of the inner yoke 6c. Further, in the present embodiment, the outer yoke 6d supports and fixes the peripheral edge side of the spring member 5.

The movable portion 6b of the linear motor portion 6 comprises a permanent magnet 6g and a cylindrical holding member 6h for holding the permanent magnet 6g. The cylindrical holding member 6h is reciprocally housed in the reciprocating path, and is formed of a disc portion 6j integrally connected to a peripheral edge portion 6I for fixing the permanent magnet 6g. Also, the disc portion 6j
The central part of is fixed to the central part of the spring member 5. In addition,
The permanent magnet 6g is arranged at a position facing the coil 11, and a certain minute gap is formed between them. The inner yoke 6c and the outer yoke 6d are arranged on a concentric circle in order to uniformly maintain this minute gap over the entire circumference.

The connecting rod 7a of the connecting mechanism portion 7 is composed of an elongated rod-shaped member. The piston 4 is provided at one end on the lower side in the figure, and the other end on the upper side is the center of the disc portion 6j of the cylindrical holding member 6h. And is fixed to the central part of the spring member 5. The other end is connected by the bolt 7 in this embodiment.
It is formed into a detachable structure by b.

The head cover portion 9 is fixed to the end face side of the collar portion 3a of the cylinder 3 via the valve plate 12. A suction valve (not shown), a discharge valve (not shown), etc. that can communicate with the compression chamber 8 are assembled to the valve plate 12, and these are provided in the head cover 9 at a suction side space (not shown) and It is connected to each of the discharge side spaces (not shown). The suction pipe and the discharge pipe (not shown) provided on the closed container 1 side are connected to the suction side space and the discharge side space, respectively.

The operation of the linear compressor configured as described above will be described below.

First, when the coil 11 of the fixed portion 6a is energized, a thrust force proportional to the current is generated between the movable portion 6b and the permanent magnet 6g according to Fleming's left-hand rule. Due to the generation of this thrust, a driving force that moves along the axial direction acts on the movable portion 6b. The cylindrical holding member 6h of the movable portion 6b is
Since it is connected to the spring member 5 together with the connecting rod 7a, the piston 4 moves. Here, the coil 11 is energized with a sine wave, and forward and reverse thrusts are alternately generated in the linear motor unit 6. Then, the piston 4 reciprocates by the forward and reverse thrusts that are alternately generated.

The refrigerant is introduced into the closed container 1 through the suction pipe. The refrigerant introduced into the closed container 1 enters the compression chamber 8 from the suction side space of the head cover portion 9 through the suction valve mounted on the valve plate 12. Then, it is discharged outward from a discharge pipe (not shown) from the discharge valve assembled to the valve plate 12 through the discharge side space of the head cover 9.

As described above, in the linear compressor of this embodiment, the concave groove 4c is formed in the circumferential direction at the piston tip portion 4b on the compression chamber 8 side, and the seal member 10 is arranged in the concave groove 4c. Since the seal member 10 is curvedly extended toward the compression chamber 8 and the concave groove 4c and the inner peripheral surface 3c of the cylinder 3 are sealed, the refrigerant in the compressor is In the flow, when the refrigerant flowing into the compression chamber 8 is compressed by the piston 4, the gas pressure in the compression chamber 8 acts on the seal member 10 and the shaft of the concave groove 4c arranged in the piston tip portion 4b. Direction and inner surface 3 of cylinder 3
The seal member 10 is pressed in the radial direction of c. Therefore, it passes from the compression chamber 8 through the gap between the cylinder 3 and the piston 4,
The leakage of the refrigerant into the closed container 1 is prevented. Especially the sealing member 10
By curving and extending, the seal length in the radial direction can be taken as compared with the conventional ring-shaped seal member, and the sealing performance can be improved. Therefore, the compression loss of the compressor is reduced,
A highly efficient linear compressor can be realized.

[0028]

Second Embodiment FIG. 2 is a sectional view showing the overall configuration of a linear compressor according to a second embodiment of the present invention.

This embodiment differs from the first embodiment in that
The seal member 13 is attached to the end surface portion 1 of the piston 14 on the compression chamber 8 side.
4a and the end plate 15, and is fixedly supported by a bolt 15a.

The operation of the linear compressor configured as described above will be described below with reference to FIG.

The refrigerant is introduced into the closed container 1 through the suction pipe. The refrigerant introduced into the closed container 1 enters the compression chamber 8 from the suction side space of the head cover portion 9 through the suction valve mounted on the valve plate 12. Then, it is discharged outward from a discharge pipe (not shown) from the discharge valve assembled to the valve plate 12 through the discharge side space of the head cover 9.

As described above, in the linear compressor of the present embodiment, the seal member 13 is connected to the piston end surface portion 14a and the end plate 1.
It is configured to be sandwiched and supported by 5. As a result, since the seal member 13 is sandwiched and supported by the separate end plate 15, the seal area in the axial direction can be made larger, so that the leakage of the refrigerant during compression can be prevented and the sealing performance can be further improved. Therefore, the compression loss of the compressor is reduced and the efficiency can be improved.

[0033]

[Third Embodiment] FIG. 3 is a sectional view showing the overall configuration of a linear compressor according to a third embodiment of the present invention.

In this embodiment, in the linear compressor according to the second embodiment, the piston end surface 16a has a convex shape,
The connection with the end plate 17 is fastened with a bolt 17a. Here, the sandwiching space of the seal member 18 is adjusted by the protruding height of the convex shape.

The operation of the linear compressor configured as described above will be described below with reference to FIG.

The refrigerant is introduced into the closed container 1 through the suction pipe. The refrigerant introduced into the closed container 1 enters the compression chamber 8 from the suction side space of the head cover portion 9 through the suction valve mounted on the valve plate 12. Then, it is discharged outward from a discharge pipe (not shown) from the discharge valve assembled to the valve plate 12 through the discharge side space of the head cover 9.

As described above, in the linear compressor of the present embodiment, the piston end surface 16a is formed in a convex shape, and the sandwiching space of the seal member 18 is adjusted by the protruding height of the convex shape. As a result, if the sandwiching space is too wide, the seal member 18 rattles, increasing the leakage of the refrigerant gas. Further, if the sandwiching space is too narrow, the seal member 18 is rigidly fixed,
Even if the gas pressure acts, it becomes difficult for the sealing member 18 to uniformly contact the sealing surface, which may promote the leakage of the refrigerant. Therefore, by the end plate 17 and the seal member 18,
By ensuring an appropriate sandwiching space, it is possible to obtain the effect of suppressing variations in sealing performance.

Although the piston end surface 16a is provided with a convex shape, the same effect can be obtained by providing the end plate 17 with a convex shape and adjusting the sandwiching space.

[0039]

[Fourth Embodiment] FIG. 4 is a sectional view showing the overall structure of a linear compressor according to a fourth embodiment of the present invention.

In this embodiment, the linear compressor according to the first, second or third embodiment is further provided with a step on the outer peripheral surface 19a of the piston 19.

The operation of the linear compressor configured as described above will be described below with reference to FIG.

The refrigerant is introduced into the closed container 1 through the suction pipe. The refrigerant introduced into the closed container 1 enters the compression chamber 8 from the suction side space of the head cover portion 9 through the suction valve mounted on the valve plate 12. Then, it is discharged outward from a discharge pipe (not shown) from the discharge valve assembled to the valve plate 12 through the discharge side space of the head cover 9.

As described above, since the linear compressor of the present embodiment has a structure in which the outer peripheral surface 19a of the piston 19 is provided with a step, the outer peripheral surface 19a and the inner peripheral surface 3c of the cylinder 3 are formed.
Since the sliding area where and contact is reduced, the sliding loss between the piston 19 and the cylinder 3 is reduced. On the other hand, the increase in leakage due to the shortened seal length can be prevented by the seal member 10 having high sealing performance, resulting in higher efficiency.

[0044]

Fifth Embodiment FIG. 5 is a sectional view showing the overall structure of a linear compressor according to a fifth embodiment of the present invention.

In the present embodiment, the elastic member 20 is further sandwiched between the end face 21a of the piston 21 and the end plate 22 in the linear compressor according to the second, third or fourth embodiment. At this time, the elastic member 20 is provided with a preload capable of opposing the compressed gas force so as not to move during the normal operation.

As described above, in the linear compressor of this embodiment, the elastic member 20 is connected to the end surface 21a of the piston 21 and the end plate 2.
Even if there is a possibility of collision between the tip of the piston 21 and the valve plate 12, such as when the pressure inside the compression chamber 8 suddenly changes, the elastic member 20 causes
It has the effect of reducing impact force and ensuring high reliability.

[0047]

As described above, according to the invention described in claim 1, a concave groove is formed in the circumferential direction at the piston tip portion on the compression chamber side, and a seal member is disposed in the concave groove.
The seal member is curvedly extended to the compression chamber side, and sealing is performed by the concave groove and the wall surface of the cylinder. With this configuration, the gas pressure in the compression chamber acts on the seal member and is distributed to the tip of the piston. The seal member is pressed in the axial direction of the provided concave groove and the radial direction of the cylinder wall surface. Therefore, the leakage of the refrigerant from the compression chamber into the closed container is prevented. In particular, by extending the seal member in a curved manner, the seal length in the radial direction can be taken as compared with the conventional ring-shaped seal member, and the sealing performance can be improved.

The invention according to claim 2 is. Claim 1
In the invention described in (1), the seal member is supported by being sandwiched between the piston end surface and the end plate. As a result, the seal member is sandwiched and supported by the separate end plates, so that a large sealing area can be secured in the axial direction, so that the sealing performance can be further improved.

The invention described in claim 3 is the same as claim 2
In addition to the invention described in (1), the piston end surface or the end plate surface is further made to have a convex shape, and the sandwiching space of the seal member is adjusted by the protruding height of the convex shape.
As a result, by securing an appropriate sandwiching space for the seal member, it is possible to obtain the effect of suppressing variations in sealing performance.

The invention described in claim 4 is the same as claim 1
Alternatively, in addition to the invention described in 2 or 3, a step is provided on the outer peripheral surface of the piston. As a result, the sliding area where the piston outer peripheral surface and the cylinder inner peripheral surface are in contact with each other is reduced, so that sliding loss is reduced. On the other hand, the increase in leakage due to the shortened seal length can be prevented by the seal member having high sealing performance, resulting in higher efficiency.

The invention described in claim 5 is the same as claim 2
Alternatively, in addition to the invention described in 3 or 4, an elastic member is sandwiched between the piston end surface and the end plate. As a result, even if there is a possibility of collision between the piston tip and the valve plate, such as when the pressure in the compression chamber suddenly changes, the impact force is mitigated by the elastic member, and high reliability can be ensured. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of a linear compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing an overall configuration of a linear compressor according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing an overall configuration of a linear compressor according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing an overall configuration of a linear compressor according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing an overall configuration of a linear compressor according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 closed container 2 Support mechanism 3 cylinders 3c wall surface 4 pistons 4c concave groove 5 spring members 6 Linear motor section 6a Fixed part 6b Moving part 7 Connection mechanism 8 compression chambers 9 head cover 10 Seal member 13 Seal member 14 pistons 15 End plate 16 pistons 17 End plate 18 Seal member 19 pistons 19a outer peripheral surface 20 Elastic member 21 pistons 22 End plate

Claims (5)

[Claims] 1. A cylinder supported by a support mechanism in an airtight container, a piston slidably supported by the cylinder along its axial direction, a head cover, and between the piston and the head cover. A compression chamber, a spring member that applies a force in the axial direction to the piston, a connecting mechanism that connects the piston and the spring member, a fixing portion fixed to the cylinder, and the piston. A linear motor unit having a movable part that is configured to be formed, wherein a concave groove is formed in the circumferential direction at the piston tip portion on the compression chamber side, and a seal member is arranged in the concave groove. A linear compressor, wherein the seal member is curvedly extended toward the compression chamber, and sealing is performed between the concave groove and the wall surface of the cylinder. 2. The linear compressor according to claim 1, wherein the seal member is supported by being sandwiched between the end face of the piston and the end plate. 3. The linear compressor according to claim 2, wherein the piston end surface or the end plate surface has a convex shape, and the sandwiching space of the seal member is adjusted by the protruding height of the convex shape. 4. The linear compressor according to claim 1, 2, or 3, wherein a step is provided on the outer peripheral surface of the piston. 5. The linear compressor according to claim 2, 3 or 4, wherein an elastic member is sandwiched between the piston end surface and the end plate.