KR20130099917A - Clearance pocket for reciprocating compressor - Google Patents

Abstract

The nut which is screwed to the rod of the clearance piston is made into two components which engage through a spring member, and aims at enabling stable operation | movement and remote operation etc. by screwing without a rattling. The clearance pocket of the reciprocating compressor according to the present invention includes a rod 59 provided in the clearance piston 58 and provided with a male screw 59a and held in a non-rotating state by the rotation preventing member 84, and the male screw. A nut 74 screwed to the 59a, and first and second nut portions 75 and 76 that form the nut 74 and are urged in opposite directions through the spring member 77 to be engaged with each other. The structure is such that there is no rattling in the engagement of the screw, and stable operation can be obtained even if the variable load acts on the rod 59.

Description

Clearance pocket for reciprocating compressors {CLEARANCE POCKET FOR RECIPROCATING COMPRESSOR}

The present invention relates to a clearance pocket of a reciprocating compressor, and in particular, a nut that is screwed to a rod of a clearance piston is composed of two components engaged through a spring member, and stable operation is achieved by screwing smoothly. The present invention relates to a novel improvement for enabling remote operation and the like.

One method of capacity control of a reciprocating compressor conventionally used is a clearance pocket. As a typical structure, the structure disclosed by patent document 1 like FIG. 3 is mentioned.

That is, in FIG. 3, the balance pocket 61 is partitioned by slidingly inserting the second piston body 7 into the clearance pocket 3 and the clearance pocket main body 60, and the pressure is communicated by the communication path 62. While the chamber 2a and the balance chamber 61 communicate with each other, the second piston body 7 is connected to the first piston body 4 by the first connecting rod 5 so that the gas in the pressure chamber 2a A balance device 6, in which pressure is guided to the balance chamber 61 against the control chamber 31, and an operating device for moving the first piston body 4 to a predetermined position to increase or decrease the volume of the control chamber 31. (Drive part of the clearance pocket) 8, and hydraulic means 11 is used as an actuator. In addition, when the capacity of the compressor is to be decreased, the clearance volume of the cylinder 1 is increased by opening the clearance pocket 3 connected in the cylinder 1. In the reciprocating compressor, even when the discharge stroke is completed and the suction stroke is completed, the compressed gas remaining in the gap volume in the cylinder 1 expands, so that the suction of the gas does not proceed until the pressure in the cylinder 1 becomes lower than the suction pressure. Do not. If the gap volume is made larger, the volume occupied by the inflation gas in the intake stroke increases, and the intake amount decreases accordingly. In this capacity control system, the amount of gas itself compressed by the piston 2 decreases, so that power consumption can be reduced.

Moreover, the structure disclosed by patent document 2 like FIG. 4 is mentioned as a variable displacement reciprocating compressor using a clearance pocket.

That is, FIG. 4 is sectional drawing which shows the clearance pocket of the principal part of a reciprocating compressor, The clearance adjustment rod 43 closes the cylinder 40 in which the taper rod part 43t of the front end side receives a piston, and has clearance clearance ( A tapered hole gas passage hole 41c provided in the partition wall 41b of the cylinder cover 41 having the 41a and communicating with the clearance pocket 41a and the head side gas compression chamber 40h of the cylinder 40. The female screw of the metal rod support member 44 fixed to the outer cover 42 which closes the cylinder cover 41 by screwing the male screw of the screw rod portion 43s on the proximal side, The protruding end of the gap adjusting rod 43 from the metal rod supporting member 44 is connected to the output shaft of the stepping motor 45, and the gap adjusting rod 43 is freely rotated in the forward / reverse direction to extend the lengthwise direction. Reciprocating with And the castle.

Therefore, if the gap volume is continuously changed by remote operation, the suction amount of the compressor is also continuously changed, so that even if the amount of gas required for the process changes at any time, a large energy saving effect can be obtained by compressing only the required gas amount. For this reason, the apparatus which comprises the actuator so that the volume of a clearance pocket can be remotely operated, and controls to discharge a required amount automatically through a control apparatus using a measured value according to process conditions, such as discharge pressure, is used.

Japanese Patent Laid-Open No. 11-82314 Japanese Unexamined Patent Publication No. 10-122138

In the conventional configuration of FIG. 3 described above, the hydraulic cylinder is used because it can exert a large force with a small actuator and the working oil does not cause vibration due to the variable load because the compressibility is very small. Since the pressure fluctuations corresponding to the suction / compression / discharge stroke of the gas into the cylinder act on the capacity adjustment piston (clearance piston) of the clearance pocket directly connected to the gas compression chamber of the cylinder, a large fluctuation load acts.

In addition, for example, in a compressor for oxygen gas having a high flammability, a driving method using no hydraulic pressure is preferable in order to avoid ignition by high pressure oxygen.

In addition, in the conventional configuration of FIG. 4 described above, the tapered rod portion at the tip of the screw rod portion is inserted into the tapered hole-shaped gas passage hole, and the degree of communication with the clearance pocket is adjusted according to the insertion state. Since the gas inlet / outlet passage is narrow, there is a disadvantage that the pressure loss is large.

In addition, although not shown in figure, the drive by a screw actuator is also used in the manual clearance pocket. In this case, the screw surface may be hit by the variable load, which may cause damage. In order to avoid this, in the manual type, at the time when the movement of the piston is finished, the lock nut is tightened to prevent damage caused by the impact of the screw surface due to the variable load. However, in order to rotate the two nuts individually by remote operation, a complicated mechanism is required, and there is a problem in terms of installation space and cost, and it is difficult to increase the reliability of the machine.

Here, the present invention is a reciprocating compressor that allows a nut that is screwed to a rod of a clearance piston by two members engaged with a spring member, and enables stable operation, remote operation, etc. by screwing without a rattling. The purpose is to provide a clearance pocket.

The clearance pocket of the reciprocating compressor according to the present invention includes a cylinder in which a suction port and a discharge port are formed and a piston is provided therein; An upper gas compression chamber and a lower gas compression chamber divided by the piston in the cylinder; A clearance pocket body provided above the cylinder and in communication with the upper gas compression chamber, the clearance pocket body having a pocket chamber and a pocket back pressure chamber; A clearance piston in the clearance pocket body; In the clearance pocket of the reciprocating compressor provided with the drive body for sliding the clearance piston, and the volume of the pocket chamber communicating with the upper gas compression chamber is variable by sliding of the clearance piston. A rod provided in and provided with a male screw, and held in a non-rotating state by the rotation preventing member; A nut screwed to the male screw; A first gear and a second nut part which form the nut and are pressed against each other through a spring member and engaged with each other, and further comprising: a first gear provided on an outer circumference of the nut, and provided in the driving body; A second gear engaged with the first gear and configured to perform movement of the rod and the clearance piston by driving the drive body; and further, as a piston back pressure of the clearance piston, the suction pressure and the discharge pressure of the cylinder. It is the structure which acts the intermediate | middle intermediate pressure of this, and is the structure which acts the suction pressure of the said cylinder as a piston back pressure of the said clearance piston, and the said spring member is a structure which consists of a disc spring.

Since the clearance pocket of the reciprocating compressor by this invention is comprised as mentioned above, the following effects can be acquired.

That is, the cylinder is formed with the suction port and the discharge port, the piston is provided therein; An upper gas compression chamber and a lower gas compression chamber divided by the piston in the cylinder; A clearance pocket body provided above the cylinder and in communication with the upper gas compression chamber, the clearance pocket body having a pocket chamber and a pocket back pressure chamber; A clearance piston in the clearance pocket body; In the clearance pocket of the reciprocating compressor provided with the drive body for sliding the clearance piston, and the volume of the pocket chamber communicating with the upper gas compression chamber is variable by sliding of the clearance piston. A rod provided in and provided with a male screw, and held in a non-rotating state by the rotation preventing member; A nut screwed to the male screw; Since the nut is formed, and the first and second nut portions are provided to be engaged with each other by being pushed in opposite directions through the spring members, the spring members are sandwiched between the two nut portions, and the female screw is loaded in advance. There is no rattling at the engaging portion of the screw, and even if the variable load acts on the rod, no breakage due to the impact of the screw surface occurs. Further, the advance and retraction of the clearance piston is performed by rotating the female screw on the cylinder side in the forward and reverse directions. In addition, in the state where the clearance piston is stopped, the force of the spring member acts on the screw surface. Therefore, even if the fluctuating load is applied, the screw surface is always pressurized in one direction and the friction force acts, and the clearance piston does not move freely. .

In addition, a first gear provided on the outer circumference of the nut, and a second gear provided on the drive body and meshed with the first gear, and the rod and the clearance piston is moved by driving the drive body. This makes it possible to change the volume of the gap by remote operation by rotating the gear using the drive body to advance / retract the clearance piston. When the control device is configured to receive the input signal from the process side and perform the advance / retract of the clearance piston to the required gas amount, it is possible to automatically adjust the capacity of the compressor.

In addition, in addition to the suction / discharge pressure of the compressor and the mass of parts, the back pressure acting on the pocket back pressure chamber of the clearance piston greatly affects the variable load acting on the clearance piston. When the average pressure in the cylinder is applied to the pocket back pressure chamber, the cylinder and the pocket back pressure chamber are connected through a restrictor such as an orifice. However, since the same action can be obtained by providing a thin hole communicating with the pocket back pressure chamber from the front surface of the clearance piston, the structure is simplified. On the other hand, since the amplitude of the load acting on the clearance piston varies greatly in the vertical direction, it is necessary to increase the spring force acting between the nuts. In addition, there is a drawback that the torque required to rotate the nut to move the clearance piston is also increased.

Even when the suction pressure is applied to the pocket back pressure chamber, the amplitude of the load is the same as above, but since the load by mass is relatively small with respect to the pressure load, the upward load and the downward load are fine. For this reason, the small spring force acting as a spring member is enough, and the torque required to rotate a nut can also be made small.

1 is a schematic configuration diagram showing a clearance pocket of a reciprocating compressor according to the present invention.
FIG. 2 is an enlarged cross-sectional view illustrating a specific configuration of the clearance pocket of FIG. 1.
3 is a configuration diagram showing a conventional reciprocating compressor.
4 is a sectional view showing a main part of a conventional reciprocating compressor.

<Examples>

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the clearance pocket of the reciprocating compressor which concerns on this invention is described, referring drawings.

Here, the same or equivalent parts as those in FIG. 3 will be described with the same reference numerals.

In FIG. 1, a cylinder 1 is provided on the compressor frame 1A, and the piston 2 driven through the piston rod 2c reciprocates in the cylinder 1. The cylinder 1 is a double-acting type for compressing gas to both the upper and lower surfaces of the piston 2, and the inlet valve (2) is provided in the upper gas compression chamber 2a and the lower gas compression chamber 2b, respectively. 12a, 12b and discharge valves 14a, 14b are provided. These cylinder valves (intake valves 12a and 12b and discharge valves 14a and 14b) are check valves which are manually opened and closed by the differential pressure before and after.

The clearance pocket 6 is provided in the upper part of the said cylinder 1, and the volume of the clearance pocket 6 is comprised so that the drive part 8 of the clearance pocket is changeable.

A suction port 13a for sucking suction gas A is formed at each suction valve 12a, 12b side of the cylinder 1, and discharge gas B is discharged at each discharge valve 14a, 14b side. The discharge port 13b for this is formed.

A pair of mounting flanges 50 are provided on both sides of the clearance pocket body 60 of the clearance pocket 6, and the upper gas compression chamber 2a of the cylinder 1 and the pocket of the clearance pocket body 60 are provided. The back pressure chamber 51 is communicated so that a force can be transmitted by the 1st pressure-pressure piping 55 provided with the 1st restrictor 52.

In addition, the suction port 13a of the suction gas A and the pocket back pressure chamber 51 communicate with each other so that a force can be transmitted by the second pressure-pressure pipe 55A having the second restrictor 54. have.

FIG. 2 is a detailed enlarged view of the clearance pocket 6 of FIG. 1, and in the clearance pocket main body 60, a clearance piston 58 composed of a slip ring 56 and a rider ring 57 slides in the vertical direction. It is provided freely.

The rod 59 provided in the clearance piston 58 extends upward through the seal 72a and the seal fixing cover 72 of the cover 70 provided on the upper surface of the clearance pocket main body 60, and this pocket The gas in the back pressure chamber 51 is comprised so that the clearance pocket main body 60 and the cover 70 may not leak out.

A male screw 59a is formed at an upper portion of the rod 59, and a nut 74 having a female screw 73 screwed to the male screw 59a is provided at an outer circumference of the male screw 59a.

The nut 74 is composed of a first nut portion 75 as an upper screw provided with a female screw 73 and a second nut portion 76 as a lower screw provided with a female screw 73. 75, 76 are comprised so that it may slide slightly in the state pressed in the reverse direction through the spring member 77 which consists of a disc spring etc., for example.

As for the said nut parts 75 and 76, when the spring force by the spring member 77 becomes optimal and the backlash does not exist between the male screw 59a and the female screw 73, a fixed screw is carried out. The 78 is inserted from the outside of the second nut portion 76 so as to fix the positional relationship between the nut portions 75 and 76.

On the cover 70, the support part 79 which consists of several rod-shaped bodies etc. is provided in the state embedded vertically, and the edge part 84a of the anti-rotation member 84 provided in the said rod 59 is the said It is configured to be guided freely up and down with respect to the support portion 79, and the rod 59 only moves up and down along the positive load direction C and the negative load direction D, and does not rotate. It is.

A table-shaped machine table 90 is fixed to the upper portion of the support portion 79, and the nut 74 is rotatably held on the machine table 90 through a pair of bearings 91. The first gear 93 is fixed to the outer circumference of the second nut portion 76 on one side of the nut 74 via a key 92.

A driving body 94 made of an air motor or the like is provided on the upper portion of the machine table 90, and the second gear 96 provided on the rotating shaft 95 of the driving body 94 is the first gear 93. Is in conflict with

Accordingly, the driving of the drive body 94 causes the clearance piston 58 to move up and down by rotating the nut 74 through the respective gears 93 and 96, while supplying air to the drive body 94. By switching ports (not shown), the nut 74 is configured to enable forward / reverse rotation. Therefore, the drive part 8 of the clearance pocket of FIG. 1 is the above-mentioned external thread 59a, the nut 74, each gear 93 and 96, the machine table 90, the support part 79, and the drive body 94. ) And the like.

Next, the operation will be described. As described above, when the driving member 94 is driven to rotate the nut 74 through the respective gears 93 and 96, the nut parts 75 and 76 for constituting the nut 74 are spring members. Since it is pressurized in the opposite direction through 77, the female screw 73 is preloaded (preload), and the nut 74 is rotated due to the gas pressure applied to the clearance piston 58 and the preload. In order to achieve this, a relatively large torque is required. However, since the diameter of the first gear 93 is n times larger than the diameter of the second gear 96, the nut 74 easily rotates due to the large torque due to the large reduction ratio. The clearance piston 58 can be moved up and down with high precision by the engagement rotation between the male screw 59a and the female screw 73 without backlash, so that the volume of the gas pressure adjusting pocket chamber 31 can be changed.

As described above, when the clearance piston 58 is moved, the volume of the pocket back pressure chamber 51 is changed so that the gas is compressed / expanded. As one method for avoiding this, as shown in FIG. 1, the cylinder 1 and the pocket back pressure chamber 51 are connected to each other via a first pressure reducing pipe 55 having a first restrictor 52. In addition, although the pressure in the cylinder 1 fluctuates between the suction and discharge pressures according to the up-and-down movement of the piston 2, since there is a first restrictor 52, the pressure of the gas to the pocket back pressure chamber 51 generated by this is The entry and exit is small, and as a result, the pocket back pressure chamber 51 is maintained at the average pressure of the suction pressure and the discharge pressure. In this case, the pressure of 1/2 of the suction / discharge pressure difference alternately acts on the clearance piston 58 alternately in the direction C, D for each cycle (actually, the loaded state is the cross-sectional area of the rod 59). Is slightly changed by the difference in the hydraulic pressure area and the mass of the clearance piston 58 or the rod 59).

As another method, as shown in FIG. 1, the inlet 13a or the intake valve chamber 12A of the intake gas A of the cylinder 1 and the pocket back pressure chamber 51 are provided with a second restrictor 54. Is connected via 55A of second pressure pipes. Since the suction port 13a and the suction valve chamber 12A also experience pressure fluctuations due to the intermittent suction operation into the cylinder 1, it is preferable to insert the second restrictor 54 in the middle of the second pressure pipe 55A. desirable. In this case, roughly the load of the suction / discharge pressure differential acts on the clearance piston 58 only in the positive direction C intermittently.

This invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, size, numerical value, shape, quantity, arrangement place, etc. of each component in the above-mentioned embodiment are arbitrary and are not specifically limited as long as this invention can be achieved.

Although this invention was detailed also demonstrated with reference to the specific embodiment, it is clear for those skilled in the art that various changes and correction can be added within the thought and range of this invention.

This application is based on the JP Patent application (patent application 2010-182245) of an application on August 17, 2010, The content is taken in here as a reference.

The clearance pocket of the reciprocating compressor according to the present invention can easily perform a variable capacity operation such as, for example, gas compression, such as a chemical plant, by remote operation.

1: cylinder
1A: frame
2: Piston
2a: upper gas compression chamber
2b: lower gas compression chamber
2c: piston rod
A: suction gas
B: discharge gas
C: positive load direction
D: negative load direction
6: clearance pocket
8: Drive part of clearance pocket
12a, 12b: suction valve
12A: suction valve chamber
13a: inlet
13b: discharge port
14a, 14b: discharge valve
31: pocket room
50: mounting flange
51: pocket back pressure chamber
52: First List Character
54: 2nd List Character
55: first overpressure piping
55A: 2nd pressure piping
56: slipper ring
57: rider ring
58: clearance piston
59: load
59a: external thread
60: clearance pocket body
70: cover
71: O-ring
72: seal fixing cover
72a: seal
73: female thread
74: nuts
75: first nut part (upper thread)
76: second nut part (lower screw)
77: spring member (plate spring)
78: set screw
79: support part
84: anti-rotation member
90: machine stand
91: bearing
92: key
94: driving body
93: first gear
96: second gear

Claims (7)

A cylinder in which a suction port and a discharge port are formed and a piston is provided therein;
An upper gas compression chamber and a lower gas compression chamber divided by the piston in the cylinder;
A clearance pocket body provided at an upper portion of the cylinder and in communication with the upper gas compression chamber, the clearance pocket body including a pocket chamber and a pocket back pressure chamber;
A clearance piston in the clearance pocket body; And
A driving body for sliding the clearance piston,
In the clearance pocket of the reciprocating compressor in which the volume of the pocket chamber communicating with the upper gas compression chamber is made variable by sliding of the clearance piston,
A rod provided on the clearance piston and having a male screw, the rod being held in a non-rotating state by an anti-rotation member;
A nut screwed to the male screw; And
A clearance pocket of a reciprocating compressor constituting the nut and including a first nut portion and a second nut portion which are pressed against each other through a spring member and engaged with each other. The method of claim 1,
A first gear provided on an outer circumference of the nut, and a second gear provided on the driving body and engaged with the first gear, and reciprocating to perform movement of the rod and the clearance piston by driving of the driving body. Clearance pocket of the same type compressor. 3. The method according to claim 1 or 2,
A clearance pocket of a reciprocating compressor which acts as a piston back pressure of the clearance piston to act as an intermediate pressure between the suction pressure and the discharge pressure of the cylinder. 3. The method according to claim 1 or 2,
A clearance pocket of a reciprocating compressor which acts on the suction pressure of the cylinder as the piston back pressure of the clearance piston. 3. The method according to claim 1 or 2,
The spring member is a clearance pocket of a reciprocating compressor consisting of a disc spring. The method of claim 3,
The spring member is a clearance pocket of a reciprocating compressor consisting of a disc spring. 5. The method of claim 4,
The spring member is a clearance pocket of the reciprocating compressor according to claim 4, comprising a disc spring.

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