JPH08144954A - Gas compressor - Google Patents

Abstract

PURPOSE: To reduce a mechanical loss such as frictional resistance between a cylinder and a piston by providing a high-pressure gas generation piston to be slidably coupled to a high-pressure gas generation cylinder for giving a slide motion in such a state as integrated with a compression piston. CONSTITUTION: A gas compressor 1 is provided with a high-pressure gas generation cylinder 5 separately from a compression cylinder 4. Also, a high-pressure gas generation piston 50 is provided in such a state as slidably coupled to the cylinder 5 and capable of giving a slide motion integrally with a compression piston 40. A gas flow passage 31 is formed for connecting void space 56 to another void space 46 formed in the piston 40. Furthermore, the piston 50 has a valve 52 for causing a gas flow from the cylinder 5 to the void space 51 of the piston 50. According to this construction, the pistons 40 and 50 are caused to slide integrally in the gas compressor 1 and a system can be thereby made compact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor for reciprocating a piston fitted in a cylinder to compress gas and supply the gas to the outside. In particular, the present invention relates to a compressor that enhances the bearing effect of a gas bearing formed between a piston and a cylinder.

[0002]

2. Description of the Related Art Conventionally, in a refrigeration system, as a mechanism for compressing and supplying a refrigerant gas, a compression piston having a reciprocating motion is slid by a crank mechanism in a compression cylinder having a refrigerant gas suction valve and a discharge valve. In operation, the refrigerant gas is supplied to the evaporator or the like. However, in the compressor configured as described above, since the rotational movement of the crankshaft of the crank mechanism is converted into the reciprocating movement of the compression piston, the mechanical loss generated during power transmission is large, and the operating parts are Since it is a compression piston, crank mechanism, power source, etc., vibration and noise were large.

Therefore, as a low vibration and low noise compressor,
A gas compressor that drives a compression piston by a linear motor is under development. In a compressor using a linear motor, a compression piston is slid directly by an electromagnetic force and a restoring force of a spring. For this reason, since only the piston is used as the operating component, vibration and noise are reduced, and since the power transmission mechanism is not required, mechanical loss is reduced and miniaturization is realized.

Regarding the refrigerant gas of the refrigeration system,
In recent years, the abolition of the production and use of specific CFCs, which have a large ability to destroy the stratospheric ozone layer (hereinafter referred to as "ozone depletion coefficient"), has been proposed. Instead, the ozone depletion coefficient is small and the refrigerant characteristics are close to those of CFC It is necessary to produce and use alternative CFCs. Conventionally, in a compressor that has been used in a refrigerator or the like that uses a specific CFC as a refrigerant,
Lubricating oil for the purpose of lubrication is circulated together with the refrigerant between the compression cylinder and the compression piston formed in the compressor to reduce the frictional resistance between the compression cylinder and the compression piston. Since the lubricating oil has a strong affinity with the specific freon, it melts into the specific freon and circulates in the refrigeration system. However, "R134a" and the like, which have been proposed as alternative CFCs, have low affinity with lubricating oil, so when used as lubricating oil for compressors of refrigerators,
It may be separated from the refrigerant gas and circulated in the refrigeration system, and may remain in another mechanism that constitutes the refrigeration system, for example, a condenser, an evaporator, an accumulator, etc. and may not be circulated again in the compressor. . If the lubricating oil does not circulate in the compressor, the friction resistance between the compression cylinder and the compression piston increases, and the power source that slides the compression piston is overloaded, or the compression cylinder and the compression piston seize. There was a danger such as.

Therefore, as a compressor that does not use lubricating oil, there is a compressor in which the inner wall of the compression cylinder and the peripheral surface of the compression piston are coated with Teflon resin to reduce the frictional resistance between the compression cylinder and the compression piston. It has been developed. However, the cycle in which the compression piston reciprocates in the compression cylinder is as high as 50 Hz to 60 Hz, which causes severe wear,
In addition, the fine dust generated in the refrigeration system mixes with the refrigerant in the compressor, peels off the resin coating on the contact surface between the compression cylinder and compression piston, or clogs the contact surface between the compression cylinder and compression piston. The frictional resistance between the compression cylinder and the compression piston sometimes increased.

Therefore, in order to reduce the frictional resistance between the compression cylinder and the compression piston, the refrigerant gas circulating in the refrigeration system is caused to flow at a high pressure between the compression cylinder and the compression piston to form a film of the refrigerant gas. Compressors have been developed that employ gas bearings that form and generate bearing effects. A compressor using a gas bearing forms a hollow space inside the compression piston, opens a plurality of through holes for ejecting refrigerant gas on the peripheral surface of the compression piston, and supplies high-pressure gas from the gas flow path to the hollow space. A high pressure refrigerant gas is supplied and jetted from the through small hole to form a gas bearing between the compression cylinder and the compression piston.

[0007]

However, in a compressor using a conventional gas bearing, it is difficult to generate a gas having a high pressure sufficient to form the gas bearing. In order to produce, a compressor other than the compressor forming the refrigeration system was needed.

An object of the present invention is to enhance the effect of a gas bearing formed between a cylinder and a piston of a gas compressor used in a refrigeration system or the like, so that mechanical loss such as frictional resistance between the cylinder and the piston can be reduced. To improve the smooth operation of the compressor.

[0009]

Therefore, in the compressor of the present invention, a high pressure gas generation cylinder (5) is provided separately from the compression cylinder (4), and the high pressure gas generation cylinder (5) is slid on the high pressure gas generation cylinder (5). A high pressure gas generating piston (50) that is movably fitted and that slides integrally with the compression piston (40) is provided, and a hollow space (56) is formed inside the high pressure gas generating piston (50). A gas flow path (31) connecting the hollow space (56) and the hollow space (46) formed inside the compression piston (4) is provided, and the high pressure gas generation piston (50) includes a high pressure gas generation cylinder ( 5) A valve (52) for flowing gas from the high pressure gas generation piston (50) toward the hollow space (56) of the high pressure gas generation cylinder (50) is provided. It is equipped with a valve (51) which allows it to flow towards 50).

Further, in the compressor according to claim 2 of the present invention, the compression piston (40) and the high pressure gas generation piston
(50) is driven by a linear motor (6). Further, in the compressor according to claim 3 of the present invention, a plurality of through small holes (54) are provided on the peripheral surface of the high pressure gas generating piston (50) having a hollow space (56) inside, and the hollow Small holes through the gas in the space (56)
It is ejected from (54) to form a gas bearing between the high pressure gas generation piston (50) and the inner wall surface of the high pressure gas generation cylinder (5).

[0011]

According to the gas compressor (1) having the above structure, when the high pressure gas generation piston (50) moves in the direction of expanding the volume of the high pressure gas generation cylinder (5), the high pressure gas generation cylinder
The gas pressure in (5) decreases, the valve (51) provided in the high pressure gas generation cylinder (5) opens, and gas flows from the outside into the high pressure gas generation cylinder (5). In addition, the high pressure gas generation piston (5
When (0) moves in the direction of reducing the volume of the high pressure gas generation cylinder (5), the gas pressure of the high pressure gas generation cylinder (5) rises and the valve (51) arranged in the high pressure gas generation cylinder closes. . When the high pressure gas generation piston (50) moves in a direction to further reduce the volume of the high pressure gas generation cylinder (5), the high pressure gas is higher than the gas pressure of the hollow space (56) formed inside the high pressure gas generation piston (50). A valve installed in the high-pressure gas generation piston (50) because the gas pressure inside the generation cylinder (5) becomes higher.
(52) opens and gas flows through the valve (52) into the hollow space (56) inside the high pressure gas generating piston (50). The hollow space (5
The gas flowing into 6) passes through the gas flow path (31), flows into the hollow space (46) formed inside the compression piston (40), and is formed on the peripheral surface of the compression piston (40). The gas is formed by ejecting from the small through hole (44) toward the wall surface of the compression cylinder (4). When the high-pressure gas generation piston (50) moves again in the direction of expanding the volume of the high-pressure gas generation cylinder (5), the gas pressure in the hollow space (56) inside the high-pressure gas generation piston (50) is increased. ), The valve (52) provided in the high pressure gas generation piston (50) closes.

The cross-sectional area of the gas passage (31) connecting the hollow space (46) (56) formed in the compression piston (40) and the high-pressure gas generation piston (50) is set to the hollow space (46) (56). ) By making it smaller than the cross-sectional area of the accumulator,
The gas pressure in the hollow space (46) (56) is high pressure gas generation piston (50)
It becomes almost constant regardless of the position of.

[0013]

In the gas compressor (1) of the present invention, the compression piston (40) and the high pressure gas generation piston (50) are slid together, so that another gas for forming a gas bearing is used. The system can be downsized without the need for a compressor or the like.
Further, the gas pressure in the hollow spaces (56) (46) inside the high pressure gas generation piston (50) and the compression piston (40) is always equal to the gas pressure in the high pressure gas generation cylinder (5) and the compression cylinder (4). Or more, so that a stable gas bearing effect can be obtained. Further, since it is not necessary to use lubricating oil or the like, it can be used for a gas compressor that compresses and supplies the alternative CFC.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the gas compressor (1) of the present invention is driven by a linear motor (6) will be described in detail below with reference to the drawings. As shown in FIG. 1, the gas compressor (1) of the present invention is
Casing with suction gas inlet (13) for sucking gas from the outside and discharge gas outlet (14) for discharging gas to the outside
Inside the (12), there is provided a cylindrical gas compressor main body (11) whose lower end is supported by a spring (15). A cylindrical compression cylinder wall (16) is formed above the center of the inside of the gas compressor body (11) to form a compression cylinder (4), and surrounds the outer periphery of the compression cylinder wall (16). A linear motor (6) for driving a piston is provided in the. The piston driving linear motor (6) comprises a coil A (61) and a cylindrical coil B (62). When an alternating current is passed through the linear motor (6), the coil A (61) and the coil B (62) A magnetic force is generated between them and forms a field core. Also, the field core space (2) formed between the coil A (61) and the coil B (62)
The armature (33) of the piston (3) described later slides on the (1).

A high pressure gas generating cylinder (5) having a diameter smaller than that of the compression cylinder (4) is located on the same axis as the compression cylinder (4) of the compressor body (11) and at an opposite position by a cylinder wall (22). It has been deployed. The piston (3) has a compression piston (40) at the upper end and a high pressure gas generation piston (50) at the lower end so that it can slide on the compression cylinder (4) and the high pressure gas generation cylinder (5). Has been deployed. The piston (3) is driven by a piston drive linear motor (6), and the compression piston (40) and the high pressure gas generation piston (50)
The suspension spring (23) whose other end is supported by the compressor body (11) is suspended between and, and vertical sliding is restricted.

A suction valve A (41) and a discharge valve A (42) are provided at the upper end of the compression cylinder (4) of the compressor body (11). The suction valve A (41) is a valve that opens only in the direction in which the refrigerant gas sucked from the suction gas inlet (13) is supplied to the compression cylinder (4), and the suction valve A (41) and the suction gas inlet (13) )
Are connected by a suction gas passage A (24). The discharge valve A (42) is a valve that opens only in the direction in which the refrigerant gas compressed by the compression cylinder (4) is discharged from the compression cylinder (4), and the refrigerant gas discharged from the discharge valve A (42) Is discharged through the discharge gas passageway (26) to the outside from the discharge gas outlet (14). As shown in FIG. 8, the discharge valve A (42) has a holding spring so that the refrigerant gas flowing from the compression piston (40) described later to the hollow space A (46) does not flow out until it reaches a predetermined threshold value. A (43) has been deployed.

High pressure gas generation cylinder of the compressor body (11)
A suction valve B (51) is provided at the lower end of (5). The suction valve B (51) is a valve that opens only in the direction in which the refrigerant gas sucked from the suction gas inlet (13) is supplied to the high-pressure gas generation cylinder (5), and the suction valve B (51) and the suction gas inlet (1
3) is connected by the suction gas passage B (25).

The compression cylinder of the compressor body (11) having the above structure
A piston (3) having a slidable compression piston (40) and a high-pressure gas generation piston (50) is slidably arranged in (4) and the high-pressure gas generation cylinder (5), respectively. Inside the compression piston (40) and the high pressure gas generation piston (50),
A hollow space A (46) and a hollow space B (56) are formed respectively, and the hollow space A (46) and the hollow space B (56) are connected by a gas channel (31) having a reduced diameter. There is. In addition, a plurality of through small holes (44) (54) are formed on the peripheral surfaces of the compression piston (40) and the high pressure gas generation piston (50), respectively. Through hole (44)
Refrigerant gas flows between the hollow space A (46) and the compression cylinder (4) and between the hollow space B (56) and the high pressure gas generation cylinder (5) by the through small hole (54). The gas flow path (31) is
By reducing the diameter, it becomes a flow resistance of the refrigerant gas flowing in the gas flow path (31), and the hollow space A (46) and the hollow space B are
Has the role of accumulator between (56). In addition, an annular bottom plate (3) protruding parallel to the lower end surface of the compression cylinder (4)
On the peripheral surface of (2), the field core space (2
An armature (33) made by stacking cylindrical permanent magnets that slide on 1) is connected.

At the lower end of the high-pressure gas generation piston (50), the high-pressure gas generation cylinder (5) described above discharges high-pressure gas which is opened only toward the hollow space B (56) of the high-pressure gas generation piston (50). Valve B (52) is deployed. As shown in FIG. 9, the high pressure gas discharge valve B (52) has a high pressure gas generating piston.
A holding spring B (53) is provided so that the refrigerant gas flowing from the (50) to the hollow space B (56) does not flow in until it reaches a predetermined threshold value.

Further, a circular plate-shaped suspension spring (23) is provided on the outer wall of the gas flow path (31). The circular center of the suspension spring (23) coincides with the center of the gas flow path (31), and the circular outer periphery of the suspension spring (23) is
It extends to the compressor body (1) and is fixed. The spring coefficient of the suspension spring (23) is about 70 N / mm, which is much larger than the pushing-down force of the refrigerant gas compressed in the gas compressor (1). The natural frequency of the suspension spring (23) matches the drive frequency of the linear motor (6),
By driving the linear motor (6) to cause resonance, the compression efficiency is improved. The piston (3) that slides when the linear motor (6) is driven is
The reciprocating motion is limited by (6) and the suspension spring (23), and is hardly affected by the pressure generated by the refrigerant gas.

The inner surfaces of the compression cylinder (4) and the high-pressure gas generation cylinder (5) and the peripheral surfaces of the compression piston (40) and the high-pressure gas generation piston (50) are coated with Teflon resin. There is. Also, the compression cylinder (4) of the gas compressor body (11), which is a closed space, the high pressure gas generation cylinder
(5), hollow space A (46), hollow space B (56) and gas flow path (3
The back pressure space (27) is a space other than 1) that causes a slight pressure fluctuation due to the vertical movement of the piston (3).

The gas compressor (1) having the above structure operates as follows. In the compression cycle described later, when the linear motor (6) generates a moving magnetic field of 60 Hz by an alternating current of 60 Hz, the compression cylinder (4), the high pressure gas generation cylinder (5), the hollow space A The pressure changes in the space (46), the hollow space B (56) and the back pressure space (27) are shown in FIGS. When a current is applied to the linear motor (6) from an AC power supply of 60 Hz, a magnetic force is generated in the coil A (61) and the coil B (62), and the armature of the piston (3) arranged in the field core space (21).
(33) starts reciprocating motion.

The piston (3) in the position shown in FIG. 2 is
Starting the linear motor (6) starts the descending motion.
(Stage 1). When the pressure of the refrigerant gas in the compression cylinder (4) becomes lower than the pressure of the refrigerant gas flowing from the suction gas inlet (13) through the suction gas passage A (24) due to the lowering of the compression piston (40), The suction valve A (41) is opened, and the refrigerant gas flows into the compression cylinder (4).

At this time, the high pressure gas generating cylinder (5) is filled with the sucked refrigerant gas in step 2 described later. The high-pressure gas generation piston (50) starts to descend (moves downward in the drawing in FIG. 2), and the suction gas passage B (2
When the pressure of the refrigerant gas in the high-pressure gas generation cylinder (5) becomes higher than the pressure of the refrigerant gas in 5), the suction valve B (51) that opens in step 2 closes. Due to the lowering of the high pressure gas generation piston (50), the refrigerant gas in the high pressure gas generation cylinder (5) is compressed. When the refrigerant gas is compressed and its pressure becomes a threshold value (17.0 kgf / cm ² ) or more than the pressure of the refrigerant gas in the hollow space B (56) of the high-pressure gas generation piston (50), as shown in FIG. The discharge valve B (52) pressed in the closing direction is pushed open by the presser spring B (53), and high-pressure refrigerant gas flows into the hollow space B (56) through the discharge valve. Hollow space B
The refrigerant gas flowing into (56) flows into the hollow space A (46) of the compression piston (40) through the gas flow path (31). Also, as shown in FIG. 9, a part of the refrigerant gas is a high pressure gas generation piston (5
The gas bearing (arrow in FIG. 9) is formed by jetting from a small through hole (54) formed in the peripheral surface of (0). When the difference between the pressure of the refrigerant gas in the high pressure gas generation cylinder (5) and the pressure of the refrigerant gas in the hollow space B (56) becomes less than a threshold value, the holding spring B (53).
Due to this, the discharge valve B (52) is closed (above "Stage 1").

Piston (3) lowered to the position shown in FIG.
Starts ascending movement by the linear motor (6) (step 2). As the compression piston (40) rises, the compression cylinder
(4) The pressure of the refrigerant gas inside becomes high, the suction valve A (41) closes, and the compression piston (40) further rises, and the compression cylinder
When the refrigerant gas pressure in (4) becomes higher than the refrigerant gas pressure in the discharge gas passage (26) by a threshold value (15.0 kgf / cm ² ) or more,
As shown in Fig. 1, the discharge spring A (43) opens the discharge valve A (42) pressed in the closing direction, and the discharge valve A (42) is discharged from the compression cylinder (4) via the discharge gas passage (26). Refrigerant gas is discharged to the discharge gas outlet (14). When the refrigerant gas is discharged and the difference between the refrigerant gas pressure in the compression cylinder (4) and the gas pressure in the discharge gas passage (26) becomes equal to or less than a threshold value, the discharge valve A (43) discharges the discharge valve A. (42) closes.

At this time, the pressure of the refrigerant gas in the high pressure gas generation cylinder (5) decreases due to the rise of the high pressure gas generation piston (50). When the refrigerant gas pressure in the high-pressure gas generation cylinder (5) becomes lower than the refrigerant gas pressure in the suction gas passage A (24), the suction valve A (41) is opened and the refrigerant gas is sucked in the suction gas passage A (24). Flows into the high-pressure gas generation cylinder (5) from above (above "stage 2").

The compression cycle in which the above steps 1 and 2 are one cycle is completed, and this cycle is repeated by the operation of the linear motor.

As shown in FIG. 8, the refrigerant gas flowing into the hollow space A (46) is ejected from the small through hole (44) formed in the peripheral surface of the compression piston (40) to generate a gas bearing (FIG. 8). Arrow)
To form.

When the gas bearing is formed, the clearance A (35) between the peripheral surface of the compression piston (40) and the inner wall of the compression cylinder (4) through the small through hole (44) and the peripheral surface of the high pressure gas generation piston (50). The refrigerant gas ejected into the gap B (56) between the high pressure gas generation piston (50) and the inner wall of the high pressure gas generation piston (50) flows into the compression cylinder (4) and the high pressure gas generation cylinder (5), respectively, and a part of the refrigerant gas (27). ) Flow into. The refrigerant gas flowing into the back pressure space (27) is
When (3) rises, the pressure of the refrigerant gas in the high pressure gas generation cylinder (5) decreases, so that the refrigerant gas flows into the high pressure gas generation cylinder (5) through the gap B (56). When the piston (3) descends, the pressure of the refrigerant gas in the compression cylinder (4) decreases, so that the refrigerant gas flows into the compression cylinder (4) through the gap A (35). Therefore, the refrigerant gas pressure in the back pressure space (27) is maintained at a substantially constant value at approximately the middle of the maximum gas pressure and the minimum gas pressure of the compression cylinder (4) and the high pressure gas generation cylinder (5).

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gas compressor of the present invention, in which a piston is rising.

FIG. 2 is a sectional view when the piston of the gas compressor of the present invention is most raised.

FIG. 3 is a cross-sectional view of the piston of the gas compressor of the present invention while the piston is descending.

FIG. 4 is a sectional view when the piston of the gas compressor of the present invention is most lowered.

FIG. 5 is a diagram showing pressure fluctuations in a compression cylinder portion.

FIG. 6 is a diagram showing pressure fluctuations in a high pressure gas generation cylinder portion.

FIG. 7 is a diagram showing pressure fluctuations in a hollow space A and a hollow space B.

FIG. 8 is an enlarged sectional view of a compression cylinder portion.

FIG. 9 is an enlarged cross-sectional view of a high pressure gas generation cylinder portion.

[Explanation of symbols]

 (1) Gas compressor (3) Piston (4) Compression cylinder (40) Compression piston (46) Hollow space A (5) High pressure gas generation cylinder (50) High pressure gas generation piston (56) Hollow space B (6) Linear motor

Claims (3)

[Claims] 1. A hollow space (46) is provided inside a compression piston (40) slidably fitted in a compression cylinder (4), and gas sucked into the hollow space (46) is compressed. Oil-less gas compression in which a gas bearing is formed between the compression piston (40) and the inner wall surface of the compression cylinder (4) by ejecting from a plurality of small through holes (44) provided on the circumferential surface of the piston (4). At the machine
In the gas compressor (1), a high pressure gas generation cylinder (5) is provided separately from the compression cylinder (4), and the high pressure gas generation cylinder (5) is slidably fitted to the compression piston (40). ) And a high-pressure gas generation piston (50) that slides integrally with the high-pressure gas generation piston (50) to form a hollow space (56) inside the hollow space (56) and the compression piston (4). ) A gas flow path (31) that connects to the hollow space (46) formed inside is provided, and the high pressure gas generation piston (50) is connected to the high pressure gas generation cylinder (5) from the high pressure gas generation piston (50). Hollow space (56)
Equipped with a one-way valve (52) for flowing gas toward the high pressure gas generation cylinder (50) and a one-way valve (51) for flowing gas from the outside toward the high pressure gas generation cylinder (50). A gas compressor characterized by comprising. 2. The compression piston (40) and the high-pressure gas generation piston (50) are arranged in the same axial direction and integrally connected, and are driven by a linear motor (6).
The described gas compressor. 3. A plurality of small through holes (54) are provided on the peripheral surface of the high-pressure gas generating piston (50) having a hollow space (56) inside, and small holes (54) are formed through the gas in the hollow space (56). 2.) The gas compressor according to claim 1, wherein a gas bearing is formed between the high pressure gas generating piston (50) and the inner wall surface of the high pressure gas generating cylinder (5) by ejecting the gas bearing.