JP2002039065A - Reciprocating compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible that pressure pulsation by exhaustion gas is kept low when compressed gas is joined at one place to be exhausted all together in a reciprocating compressor having a plurality of gas compressing sections. SOLUTION: Four gas compressing sections including a first gas compressing section 1 to fourth gas compressing section 4 are arranged in a way that each one's position is shifted by 90 deg. against one another to reach 360 deg. and each four gas compressing section is connected to a head cylinder 5 via each connect pipe including a first connect pipe 6 to a forth connect pipe. With each connect pipe being set up at a prescribed length, the compressed gas sent from each gas compressing section offset its pressure wave one another at a joint point in the head cylinder 5 so that the pressure pulsation by the gas collectively exhausted from the joint point T in the head cylinder 5 is kept low, while a crankpin make a turn (2π).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating compressor having a plurality of gas compressors, and more particularly to a reciprocating compressor capable of suppressing pressure pulsation due to discharge gas.

[0002]

2. Description of the Related Art An ordinary reciprocating compressor has one gas compression section comprising a cylinder and a piston.
There is also a reciprocating compressor provided with a plurality of such compressors. Conventionally, a reciprocating compressor provided with a plurality of gas compressors has a conventional structure in which three gas compressors 101, 102, and 103 each including a cylinder and a piston are orthogonally connected to a shaft 105, as shown in FIG. It is known that the pistons are opposed to each other so as to reciprocate on 106, and the gas is compressed in order from the gas compression unit 101 to a high pressure, and the gas compression unit 103 is used as the final high-pressure compression unit.

In the reciprocating compressor 100, a pair of opposed pistons 51 and 53 are connected to the yoke 1A,
The other pair of opposing pistons 52 and 54 are connected to a yoke 1B disposed 90 degrees out of phase with the yoke 1A. By rotating the crankshaft 57 by the rotor 56 of the electric motor unit 55 shown in FIG. 4B, the crankpin 58 is eccentrically rotated around the crankshaft 57, and the pair of pistons 51 and 53 are moved only in the direction of the shaft 105. And a scotch yoke mechanism that reciprocates the other pair of pistons 52 and 54 only in the direction of the shaft 106.

The scotch yoke mechanism is a type of double-slider crank mechanism described with reference to a schematic diagram shown in FIG. 6, and converts rotary motion into reciprocating motion or reciprocating motion into rotary motion. In the above case, the rotary motion is converted into a reciprocating motion, and the Scotch yoke mechanism having the yokes 1A and 1B is provided between the lower balancer 59 and the upper balancer 60 provided on the crankshaft 57 shown in FIG. Are mounted and engaged with the yokes 1A and 1B, so that vibrations and the like are suppressed and stable operation is performed.

[0005] In this reciprocating compressor 100, as the number of compression stages increases, the diameter of the cylinder and piston decreases as the gas compression section, that is, the gas compression section formed by the cylinder and piston, becomes higher in pressure. It is configured to engage with the crank pin and operate in conjunction with the step shifted in phase.

Meanwhile, there is a reciprocating compressor in which gases compressed by a plurality of gas compressors are combined into a single location via connecting pipes and discharged in a concentrated manner in order to increase the amount of discharged gas. In this case, the compression performance of each gas compression unit is the same, that is, the size of the cylinder and the piston are the same, and the compression operation of each gas compression unit is shifted at a fixed interval with the rotation of the crankpin. The compressed gas is merged into the head cylinders provided in the sections via the connecting pipes, and the compressed gas is discharged from the head cylinder in a concentrated manner.

[0007]

In the conventional reciprocating compressor, a pressure pulsation is generated when the gas is discharged from the gas compressor, which causes vibration and noise. In particular, in the central discharge type reciprocating compressor, since the compressed gas sent through a plurality of connecting pipes joins into the head cylinder, there is a problem that a large pressure pulsation occurs due to mutual interference. For this reason, a muffler is provided in each connecting pipe to reduce the pressure pulsation of the gas discharged from each gas compression unit. And the size of the compressor body becomes larger.

Accordingly, an object of the present invention is to provide a centralized discharge type reciprocating compressor in which pressure pulsation due to interference of converging compressed gas can be suppressed without attaching a muffler to a connecting pipe. .

[0009]

As a means for technically solving the above-mentioned object, the present invention provides a plurality of gas compressing sections each including a cylinder and a piston, and the piston movement of each gas compressing section is controlled. A reciprocating compressor in which the rotational motion of a crankshaft provided in a drive source is converted into reciprocating motion by a Scotch yoke mechanism so that the reciprocating compressor is operated in conjunction with compressing the sucked gas in each gas compression unit. When the compressed gas discharged from each of the gas compressors is merged into a single location via a connecting pipe and discharged in a concentrated manner, the pressure at the time of the concentrated discharging is set by setting each of the connecting pipes to a predetermined length. The gist of the present invention is a reciprocating compressor configured to reduce pulsation.

[0010]

Next, an embodiment of a reciprocating compressor according to the present invention will be described with reference to the accompanying drawings. 1A is a plan view of the entire reciprocating compressor, FIG. 1B is a front view of the reciprocating compressor P partially broken, and FIG. 1C is a side view of the reciprocating compressor P partially broken. A plurality of gas compressors, that is, a first gas compressor 1, a second gas compressor 2,
The third gas compressing section 3 and the fourth gas compressing section 4 are arranged opposite to each other in a cross shape.

Each of these four gas compressors 1 to 4 is composed of a cylinder and a piston. Unlike the conventional compressor, the four gas compressors 1 to 4 have the same internal volume and compression performance. The piston of the compression unit 1 and the piston of the third gas compression unit 3 are coaxially connected to one yoke,
A piston of the second gas compressor 2 and a fourth gas compressor 4
Is coaxially connected to the other yoke 90 degrees out of phase.

A head cylinder 5 is mounted on the head of the cylinder in the fourth gas compression section 4, and a gas passage is provided therein, and a discharge port 5a is provided at one end thereof. And a discharge port 1a of the first gas compression section 1 is a first connection pipe 6, a discharge port 2a of the second gas compression section 2 is a second connection pipe 7, and a third gas compression section. The third discharge ports 3a are connected to each other by third connection pipes 8, respectively. As a result, the gas compressed in each of the gas compressors 1 to 4 merges into the gas passage of the head cylinder 5.

The reciprocating compressor P is of a non-lubricated type,
The cooling device Q for cooling is provided.
As shown in FIGS. 1 (b) and 1 (c), a fan motor 11 is installed on a unit base 10 in a fan casing 9, and a cooling fan 12 is attached to a tip end of a rotating shaft thereof.
An air suction port 13 with a net is provided on a side surface of the fan casing 9.

The reciprocating compressor P is mounted on the cooling device Q via a leg member 14. An anti-vibration rubber 15 is interposed at the upper end of the leg member 14 to reduce the vibration of the reciprocating compressor P. It is made to absorb. Also, columns 16 are provided upright at four corners in the casing 9 so that the reciprocating compressor P can be stably supported. Reference numeral 17 denotes a cooling casing disposed around the reciprocating compressor P. Reference numeral 18 denotes a terminal cover for protecting a connection terminal of the motor unit 19 of the reciprocating compressor P.

In the reciprocating compressor P configured as described above, when gas is supplied from a gas supply source (not shown) to the suction port 20 provided above, the gas is supplied to the first to fourth gas compressors.
Flows into the cylinders of the gas compressors 1 to 4 and is compressed by the piston. The compression process by the piston is performed by operating two yokes 90 degrees out of phase by rotating a crankpin via a crankshaft in a conventional manner with rotation of the rotor of the electric motor unit 19.

When the crankpin makes one rotation, the first to fourth gas compressors 1 to 4 are compressed in this order, and the gas compressed by the first gas compressor 1 is discharged from the discharge port 1a. The gas which is discharged and sent into the head cylinder 5 via the first connection pipe 6 and similarly compressed by the second gas compression section and the third gas compression section is supplied to the second connection section. Via the pipe and the third connecting pipe 8 respectively
Sent inside. Further, the gas compressed by the fourth gas compressor 4 is also sent into the head cylinder 5 from the discharge port 4a.

Therefore, the gases compressed by the first to fourth gas compressors 1 to 4 respectively join together in the gas passage in the head cylinder 5, and the combined compressed gas is mixed with the head cylinder 5 Are concentratedly discharged from the discharge port 5a. Thereby, the discharge amount of the compressed gas discharged from the reciprocating compressor P increases four times.

As described above, the piston of the first gas compression unit 1 and the piston of the third gas compression unit 3 opposed thereto are directly connected to one yoke. When the gas compression operation is performed, the gas suction operation into the cylinder is performed simultaneously in the third gas compression unit 3, and conversely, when the gas compression operation is performed in the third gas compression unit 3, the first gas compression operation is performed. In the compression section 1, a gas suction operation into the cylinder is performed at the same time.

Similarly, the piston of the second gas compression unit 2 and the piston of the fourth gas compression unit 4 opposed thereto are directly connected to the other yoke, which is 90 degrees out of phase. When the gas compression operation is performed in the second gas compression unit 2, the gas suction operation into the cylinder is performed simultaneously in the fourth gas compression unit 4, and conversely, the gas compression operation is performed in the fourth gas compression unit 4. When the operation is performed, the operation of sucking gas into the cylinder is simultaneously performed in the second gas compression unit 2.

For this reason, with the rotation of the crankpin, the compression operation is repeatedly performed in the order of the first gas compression unit 1 to the fourth gas compression unit 1, and a large amount of the compressed gas joined by the head cylinder 5 is removed. It can discharge continuously.

In such a reciprocating compressor P, the first
When the gases compressed by the gas compressors 1 to 4 merge with the head cylinder 5, large pressure pulsations are generated by interfering with each other. For this reason, in the present invention, pressure pulsation is reduced by adjusting the length of each connecting pipe in consideration of the phase difference in each gas compression section.

FIG. 2 schematically shows the reciprocating compressor P, wherein the length of the first connecting pipe 6 is L.
1, the length of the second connecting pipe 7 is L2, the length of the third connecting pipe 8 is L3, and the distance from the fourth gas compressor 4 to the head cylinder 5 (referred to as the fourth connecting pipe 4b) ) Is L4. The inner diameter of each connecting pipe is the same.

When the crankpin makes one rotation as described above, the compression is performed in the first to fourth gas compressors 1 to 4 sequentially, and the compressed gas is merged into the head cylinder 5 and discharged in a concentrated manner. However, if the pressure waves of the compressed gas cancel each other at the junction T, the pressure pulsation can be suppressed low. Here, since the phases of the first to fourth gas compressors 1 to 4 are shifted by 90 ° (π / 2), the pressure of each compressed gas reached when the crankpin makes one rotation (2π). It is necessary for the waves to cancel each other.

The length of each connecting pipe in the reciprocating compressor P is limited within a certain range from the size of the compressor body, and within the range, for example, the preferable length L2 of the second connecting pipe 2 is set. 1.133 m. When a pressure sensor was attached to measure the waveform of the compressed gas passing through the second connecting pipe 2, the number of peaks during one rotation of the crankpin was five. The number of rotations of the crankpin is 1
800 rpm.

The length L2 of the second connecting pipe 2 is 1.133 m
As for the length of the other connecting pipes, when a preferable length was tested within a range limited by the size of the compressor body, L1 = 0.708 m, L3 = 0.436 m, and L4 =
It has been found that pulsation can be minimized in the case of 0.298 m.

When examining the pressure waveform of the compressed gas passing through the first connecting pipe 1, the third connecting pipe 3, and the fourth connecting pipe 4, the first connecting pipe 1 rotates during one rotation of the crankpin. In No. 1, the number of peaks was eight, in the third connecting pipe 3 was thirteen, and in the fourth connecting pipe 4b, nineteen.

Based on the number of these waveforms, a pressure wave is drawn with a phase shift of 90 ° as shown in FIG. 3. When the crankpin makes one rotation (2π), the first gas compressor 1
And the pressure wave between the third gas compressing section 3 and the pressure wave opposite to the second gas compressing section 3, and the pressure wave between the second gas compressing section 2 and the fourth gas compressing section 4 opposite thereto. Indicate a state in which they cancel each other. The gas is concentrated and discharged from the junction T of the head cylinder 5 by repeating such a cycle, and the pressure pulsation at that time is suppressed to a low level.

[0028]

As described above, according to the present invention, in a reciprocating compressor having a plurality of gas compressors, the length of each connecting pipe for sending the compressed gas from each gas compressor to the junction of the head cylinder is reduced. By setting the length to a predetermined length, pressure pulsation during concentrated discharge can be suppressed to a low level. Thereby, there is an effect that the vibration and noise of the reciprocating compressor are significantly reduced. Further, since there is no need to attach a muffler to each connecting pipe as in the related art, it is possible to prevent troublesome installation work, an increase in cost due to an increase in parts, an increase in the size of the compressor body, and the like.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a reciprocating compressor according to the present invention, wherein (a) is a plan view, (b) is a partially broken front view,
(C) is a partially broken side view.

FIG. 2 is an explanatory view schematically showing a reciprocating compressor according to the present invention.

FIG. 3 is an explanatory diagram showing a state of gas pressure waves sent from each gas compression unit via a connecting pipe.

4A and 4B show a conventional reciprocating compressor, wherein FIG. 4A is a cross-sectional plan view, and FIG.

FIG. 5 is an explanatory view of a crankshaft portion.

FIG. 6 is an explanatory view of a scotch yoke mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st gas compression part 2 ... 2nd gas compression part 3 ... 3rd gas compression part 4 ... 4th gas compression part 5 ... head cylinder 6 ... 1st connection pipe 7 ... 2nd connection pipe DESCRIPTION OF SYMBOLS 8 ... 3rd connection pipe 9 ... Fan casing 10 ... Unit base 11 ... Fan motor 12 ... Cooling fan 13 ... Air suction port 14 ... Leg member 15 ... Anti-vibration rubber 16 ... Column 17 ... Cooling casing 18 ... Terminal cover 19 … Motor part 20… Suction port

 ──────────────────────────────────────────────────の Continuing on the front page (72) Kishi Atom, 2-5-1-5, Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Takayuki Mizuno 2-5-2, Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Kazuya Sato 2-chome 5-5 Keihanhondori, Moriguchi-shi, Osaka (72) Inventor Yasuo Sakamoto 2 Keihanhondori, Moriguchi-shi, Osaka 5-5-5 Sanyo Electric Co., Ltd. F-term (reference) 3H003 AA02 AB03 AC01 BA05 3H076 AA04 BB02 CC07 CC25 CC93 CC95

Claims (1)

[Claims] A plurality of gas compressing sections each comprising a cylinder and a piston are provided, and the piston motion of each gas compressing section converts the rotational motion of a crankshaft provided in a drive source into a reciprocating motion by a Scotch yoke mechanism. This is a reciprocating compressor that is linked to each other, compressing the inhaled gas by each gas compression unit and merging the compressed gas discharged from each gas compression unit to one place via the connecting pipe. A reciprocating compressor characterized in that, when performing concentrated discharge by setting, the connection pipes are set to a predetermined length to reduce pressure pulsation during concentrated discharge.