JP2001020863A - Reciprocating type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocating type compressor to prevent the occurrence of local slide and gouging to a slide part between a cylinder and a piston and perform stable and smooth rectilinear advance of a piston. SOLUTION: A compression chamber 10 is formed between the top face 5b of a piston 5 and a cylinder 4 and the piston 5 is coupled to the rotor of a linear motor to make reciprocating rectilinear advance. In a so formed reciprocating type compressor, a groove 11a intermittently or continuously extending in a peripheral direction is formed in the side peripheral surface 5a of the piston 5 and a number of communicating grooves 11b to perform intercommunication between the groove 11a and the top face 5b of the piston 5 are formed in the side peripheral surface 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating compressor including a vibrating compressor.

[0002]

2. Description of the Related Art Reciprocating compressors, including vibrating compressors, are known for use in refrigerators and air conditioners, etc.
As a conventional vibratory compressor, for example, Japanese Patent Application Laid-Open No. 04-34
There is one disclosed in Japanese Patent No. 7460.

FIG. 1 shows the basic structure of a reciprocating compressor. The compressor main body 2 includes a linear motor 3, a cylinder 4 including a cylinder main body 15 and a cylinder head 7, a piston 5, a compression chamber 10, a support block 6, and an elastic support 8, and a plurality of suspension springs (not shown). The elastic casing is elastically supported in the closed casing 1.

The linear motor 3 comprises a stator 3a to which a permanent magnet 3c is fixed, and a mover 9 having a coil 3b. The mover 9 is fixedly connected to the piston 5. The piston 5 is supported by a cylinder 4 and an elastic support member 8 so as to be capable of reciprocating and rectilinear movement. Lubricating oil is applied between a side peripheral surface 5a of the piston 5 and an inner peripheral surface 4a of the cylinder 4. Is being worn. The compression chamber 10 is formed between the cylinder 4 and the top surface 5b of the piston 5.
The cylinder head 7 has a low-pressure chamber 7 a communicating with a suction pipe (not shown) and a high-pressure chamber 7 b communicating with a discharge pipe (not shown), and is connected to the compression chamber 10. The elastic support 8 is formed by stacking leaf springs, and the outer end is
The inner ends are respectively connected to the pistons 5.

Next, the mechanism of the reciprocating compressor will be described. The coil 3b of the linear motor 3 is energized from the AC power supply, and an electromagnetic force that causes the mover 9 to move straight in the axial direction of the piston 5 is generated by the action of the magnetic field generated by the permanent magnet 3c. The piston 5 connected to the mover 9 by this electromagnetic force
Resonates by utilizing the elastic force of the elastic support member 8 to efficiently reciprocate and rectilinearly move.

[0006] Refrigerant gas from a cooling system (not shown) is guided to a low-pressure chamber 7 a of a cylinder head 7 via a suction pipe (not shown), and reaches a compression chamber 10 in the cylinder 4. The refrigerant gas that has reached the compression chamber 10 is compressed by the linear movement of the piston 5. The compressed refrigerant gas is once discharged into a high-pressure chamber 7b in the cylinder head 7 through a discharge valve (not shown) arranged in the cylinder head 7,
It is discharged to the cooling system via a discharge pipe (not shown).

Further, the conventional reciprocating compressor is configured such that the axes of the linear motor 3, the cylinder 4, and the piston 5 are aligned, and the side peripheral surface 5a of the piston 5 is smooth.

[0008]

However, in the above-described conventional configuration, when the axes of the cylinder, piston, elastic support (plate spring), etc. are shifted or inclined, the linear motor is fixed. When the armature and mover are assembled with their axes shifted, when the mover of the linear motor is attracted in the radial direction by the magnetic force of the permanent magnet, etc. Torsion occurs, and strong resistance acts on the piston, especially during the compression stroke, and these become prominent. As a result, problems such as a decrease in the compressor effect due to an increase in sliding loss and a decrease in reliability due to wear of the sliding portion occur. there were.

In view of these problems, the present invention provides a highly reliable reciprocating compressor in which the piston moves linearly and smoothly in a stable and smooth manner without local sliding or twisting in the sliding portion between the cylinder and the piston. It is intended to do so.

[0010]

According to a first aspect of the present invention, a compression chamber is formed between a top surface of a piston and a cylinder, and the piston is connected to a mover of a linear motor to reciprocate linearly. In the machine, on the side peripheral surface of the piston, a groove extending intermittently or continuously in the circumferential direction is provided, and a large number of communication grooves communicating the groove and the top surface of the piston are provided on the side peripheral surface. Features.

According to the first aspect of the present invention, during the compression stroke of the piston, the pressure of the compression chamber, which becomes high, is guided to the groove extending intermittently or continuously in the circumferential direction through the communication groove. When the pressure is uniformly applied in the circumferential direction of the piston, a function as a fluid bearing is performed between the side peripheral surface of the piston and the inner peripheral surface of the cylinder.

[0012] By the centering action of the fluid bearing, the linearly moving piston can maintain the axial center and perform a stable and smooth linear movement.

A second invention of the present application is directed to a reciprocating compressor in which a compression chamber is formed between a top surface of a piston and a cylinder, and the piston is connected to a mover of a linear motor and reciprocates linearly. On the side peripheral surface of the cylinder or on the inner peripheral surface of the cylinder, a number of concave portions whose cross-sectional area decreases toward the bottom dead center of the piston in the reciprocating direction of the piston are arranged side by side in the circumferential direction, and the minimum cross-sectional area of these concave portions is The groove communicating with the portion is provided intermittently or continuously in the circumferential direction.

According to the second aspect of the present invention, during the compression stroke of the piston, the fluid between the piston and the cylinder is pushed toward the minimum cross-sectional area of the recess by the friction when the piston moves linearly,
Due to the fluid wedge action, a high pressure is introduced into the groove extending intermittently or continuously in the circumferential direction. When the high-pressure fluid acts in the circumferential direction of the piston, an action as a dynamic pressure bearing is performed between the side peripheral surface of the piston and the inner peripheral surface of the cylinder.

[0015] By the centering action of the dynamic pressure bearing, the linearly moving piston can maintain the axial center and perform a stable and smooth linear movement.

The fluid is generally a lubricating oil, specifically a refrigerant gas. Further, it is preferable that the shape of the concave portion is triangular or V-shaped groove and W-shaped groove whose center is symmetrical with the piston reciprocating direction.

In the second invention, in addition to the above configuration,
A number of recesses whose cross-sectional area decreases toward the piston top dead center in the reciprocating direction of the piston are arranged side by side in the circumferential direction on the side peripheral surface of the piston or the inner peripheral surface of the cylinder. By providing the groove communicating with the portion intermittently or continuously in the circumferential direction, the piston can function as a dynamic pressure bearing even in the suction stroke of the linear movement of the piston.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.

The basic configuration of the reciprocating compressor according to the first embodiment of the present invention is the same as the basic configuration of the prior art, and is as described with reference to FIG.

FIGS. 2 and 3 show the structure of the piston and the cylinder of the present embodiment.

2 and 3, the piston 5 has a plurality of grooves 11a extending intermittently in the circumferential direction on the side peripheral surface 5a, and a communication groove communicating these grooves 11a with the top surface 5b of the piston 5. 11b. The groove 11a and the communication groove 11b are formed in the circumferential direction of the piston side peripheral surface 5a so that the high pressure guided from the compression chamber 10 acts uniformly on the inner peripheral surface 4a of the cylinder 4 during the compression stroke of the piston. They are arranged uniformly.

The groove 11a and the communication groove 11b preferably have a depth of 2 μm to 50 μm and a width of 300 μm to 2 mm, respectively.

The reciprocating compressor assembled as described above has a high pressure in the compression chamber 10 during the compression stroke of the piston 5.
Is introduced into each groove 11a through the communication groove 11b, and the lubricating oil in the groove 11a uniformly distributed in the circumferential direction is made high pressure to apply the pressure to the inner peripheral surface 4a of the cylinder 4, thereby forming a fluid bearing. As a result, the linear motion of the piston can be stably and smoothly performed, and a highly reliable reciprocating compressor can be provided.

In the first embodiment of the present invention, the groove 11a is formed intermittently in the circumferential direction of the side peripheral surface 5a. However, the groove 11a extends continuously in the circumferential direction. One
It is also possible to form with the groove of the book. If no lubricating oil is used, the pressure in the groove 11a becomes high during the compression stroke.

Next, a second embodiment of the present invention will be described with reference to FIGS. The basic configuration of this embodiment is the same as that of the first embodiment, and is as described with reference to FIG.

The piston 5 of this embodiment is formed as shown in FIGS. A first concave portion 12b whose sectional area decreases in a direction toward the bottom dead center of the piston 5 in a reciprocating direction of the piston 5 is provided on a side peripheral surface 5a of the piston 5; A second concave portion 12c whose cross-sectional area decreases in the direction toward the dead center is formed. A large number of the first concave portions 12b are arranged in three rows in the circumferential direction, and the second concave portions 12c are similarly arranged in three rows.
A large number are arranged in the circumferential direction across the rows. The rows of the first recesses 12b and the rows of the second recesses 12c are arranged alternately, and these recesses 12b and 12c are provided between the rows of the adjacent first recesses 12b and the rows of the second recesses 12c.
Are formed as annular grooves communicating with each other in the circumferential direction. The recesses 12b and 12c are formed in a W-shaped groove whose center is a line of symmetry in the reciprocating direction of the piston 5.

The annular groove 12a has a depth of 2 μm to 50 μm.
μm and a width of 300 μm to 2 mm. The W-shaped recesses 12b and 12c have a depth of 2 μm to 50 μm and a width of 30 μm.
0 μm to 2 mm, the angle with respect to the central symmetry line is, for example, 30
°.

When the piston 5 is assembled in the above-described manner and the piston 5 moves straight, during the compression stroke, the lubricating oil in the first concave portion 12b increases in pressure toward the minimum area by the fluid wedge action, and the pressure in the groove 12a increases. During the suction stroke, the lubricating oil in the second recess 12c increases in pressure toward the minimum area due to the fluid wedge action, and the lubricating oil in the groove 12a becomes high in pressure, so that the lubricating oil in the groove 12a has a high pressure. Works, the piston 5 holds the shaft center, and allows the linear movement of the piston 5 to be performed stably and smoothly, thereby providing a highly reliable reciprocating compressor.

The concave portions 12b and 12c and the grooves 12 of the present embodiment
a can be configured in various ways. That is, when the concave portions 12b and 12c are formed of a triangular shape or a V-shaped groove, or when the number of rows is different, the groove 12a
Is formed so as to extend in the circumferential direction intermittently,
2a and recesses 12b and 12c are formed on the inner peripheral surface 4a of the cylinder 4.
In this case, the same effects as in the present embodiment can be obtained.

According to the present embodiment, it is possible to prevent local sliding and twisting in the sliding portion between the piston 5 and the cylinder 4 over the entire stroke of suction, compression and discharge, thereby increasing the sliding loss. Thus, it is possible to prevent a decrease in reliability such as a decrease in the efficiency of the compressor and wear of the sliding portion. Further, unlike the first embodiment, the recesses 12b, 12c and the groove 12a do not communicate with the compression chamber 10, so that leakage of the refrigerant gas in the compression chamber 10 and an increase in re-expansion loss are minimized. Therefore, the above-described effects can be obtained without causing a decrease in volumetric efficiency and compression efficiency of the reciprocating compressor.

Even if the first recess 12b and the groove 12a are only provided on the outer peripheral surface 5a of the piston 5 or the inner peripheral surface 4a of the cylinder 4 without the second concave portion 12c, the above-described operation is performed during the compression stroke. Similar effects can be obtained.

[0032]

According to the first aspect of the present invention, the linear movement of the piston is achieved only by providing the groove and the communication groove on the peripheral surface of the piston, and by the fluid bearing action utilizing the high pressure of the compression chamber during the compression stroke of the piston. Can be performed stably and smoothly, and a highly reliable reciprocating compressor free of local sliding and prying in the sliding portion between the cylinder and the piston can be provided.

Further, according to the second aspect of the present invention, only by providing a concave portion and a groove on the peripheral surface of the piston or the inner peripheral surface of the cylinder, during the compression stroke of the piston or during the entire stroke, the dynamic pressure bearing action causes It is possible to provide a highly reliable reciprocating compressor in which the linear movement of the piston is performed stably and smoothly while maintaining the compression efficiency, and there is no local sliding or prying in the sliding portion between the cylinder and the piston.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic configuration of a reciprocating compressor according to the present invention.

FIG. 2 is a sectional view showing a piston and a cylinder according to the first embodiment of the present invention.

FIG. 3 is a perspective view thereof.

FIG. 4 is a sectional view showing a piston and a cylinder according to a second embodiment of the present invention.

FIG. 5 is a perspective view thereof.

[Explanation of symbols]

 Reference Signs List 3 Linear motor 3a Stator 4 Cylinder 4a Inner peripheral surface of cylinder 5 Piston 5a Side peripheral surface of piston 5b Top surface of piston 10 Compression chamber 11a Groove 11b Communication groove 12a Groove 12b First concave part 12c Second concave part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takafumi Asada 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Takao Yoshimura 4-5-2, Takaidahondori, Higashiosaka-shi, Osaka Matsushita Refrigeration Machinery Co., Ltd. In-house (72) Inventor Masanori Kobayashi 4-5-2, Takaida Motodori, Higashiosaka City, Osaka Prefecture F-term in Matsushita Refrigeration Co., Ltd. (Reference) 3H003 AA02 AB05 AC03 BD10 CB00 CB01 CF04 3H076 AA02 BB17 BB26 CC06 CC31

Claims (5)

[Claims] 1. A reciprocating compressor in which a compression chamber is formed between a top surface of a piston and a cylinder, and the piston is connected to a mover of a linear motor and reciprocates linearly. A reciprocating compressor comprising: a groove that extends intermittently or continuously in a circumferential direction; and a large number of communication grooves that communicate the groove and a top surface of the piston are provided on the side peripheral surface. 2. A reciprocating compressor in which a compression chamber is formed between a top surface of a piston and a cylinder, and the piston is connected to a mover of a linear motor and reciprocates linearly. On the inner peripheral surface, a number of concave portions whose cross-sectional area decreases toward the bottom dead center side of the piston in the reciprocating direction of the piston are arranged in parallel in the circumferential direction, and grooves communicating with the minimum cross-sectional area portions of these concave portions are provided. A reciprocating compressor provided intermittently or continuously in a circumferential direction. 3. The reciprocating compressor according to claim 2, wherein the recess has a triangular shape. 4. The reciprocating compressor according to claim 2, wherein the recess is a V-shaped groove or a W-shaped groove having a center symmetrical line in the reciprocating direction of the piston. 5. A large number of recesses whose cross-sectional area decreases toward the top dead center side of the piston in the reciprocating direction of the piston are provided side by side on the circumferential surface of the piston or the inner circumferential surface of the cylinder. 3. The reciprocating compressor according to claim 2, wherein the groove communicating with the minimum sectional area of the recess is provided intermittently or continuously in the circumferential direction.