KR20070081636A - Air compressor and expander - Google Patents

Abstract

An air compressor and expander is provided to prevent clearance between a screw type protrusion part of a male rotor and a screw type groove part of a female rotor by arranging end covers in both ends of a casing and installing a clearance prevention unit in one side of the end covers. An air compressor and expander comprises a male rotor(10), a female rotor(20), a casing(30), first and second end covers(40,50), a gear part(60) and a clearance prevention unit. The male rotor is shaft-coupled to a drive shaft(11), and has a screw type protrusion part(12) in an outer surface. The female rotor is shaft-coupled to a driven shaft(21) so as to be communicated with the male shaft, and is consisted of a screw type groove part(22) corresponding to the protrusion part. The casing forms compression or expansion space of air by rotation of the male rotor and the female rotor. The first and second end covers are penetration- installed with the drive shaft and the driven shaft, and seal both ends of the casing. The gear part is respectively shaft-coupled to the drive shaft and the driven shaft in any one side of the first and second end covers, and transfers power. The clearance prevention unit is installed in an opposite side of the gear unit so as to prevent clearance of the male rotor or a female rotor arranged between the first and second end covers.

Description

AIR COMPRESSOR AND EXPANDER}

1 is a conceptual diagram illustrating the basic principle of a general air cycle.

2 is a T-s diagram of a typical air cycle

3 is a cross-sectional view of a conventional air compressor / expander.

Figure 4 is a perspective view showing a conventional male rotor.

5 is a perspective view of the combination of the air compressor / expander according to the present invention.

6 is a cross-sectional view of an air compressor / expander in accordance with the present invention.

7 is a cross-sectional view taken along the line AA of FIG.

(Explanation of symbols for the main parts of the drawing)

10: male rotor 11: drive shaft

12: protrusion 20: arm rotor

21: driven shaft 22: groove

30: casing 31: first distribution port

40, 50: 1st, 2nd end cover 60: gear part

61: protruding jaw 70: play prevention means

71: tee bushing 2: coupling member

73: annular bushing 80: rear cover

90: front cover 91: second outlet

O: Oil seal B: Bearing

The present invention relates to an air compressor / expander, and more particularly, to prevent the play between the male rotor and the arm rotor rotated in the air compressor / expander applied to an air cycle that compresses or expands air to obtain a refrigeration effect. It relates to an air compressor / expander which can improve the

In general, refrigeration companies around the world are focusing on developing alternative refrigerant systems to replace R134a refrigerants, which have been used to date due to global warming and environmental issues, and are particularly environmentally friendly, safe and efficient, rather than replacing refrigerants themselves. New systems are being studied.

One of the most promising alternative cycles in recent years is an air cycle called a reverse-Bryton cycle, which is a system that uses air as a refrigerant and was developed for the first time as a gas power cycle. This cycle achieves the freezing effect by operating the cycle in reverse.

1 is a conceptual diagram illustrating the basic principle of a general air cycle, and FIG. 2 shows a T-s diagram of a general air cycle.

As shown, the air cycle is composed of a compressor (1), expander (2), first, second heat exchanger (3) (4), the compression process (1 → 2), the temperature drop process (2 → 3), expansion The cycle is composed through the process (3 → 4) and temperature rise process (4 → 1).

The compression process (1 → 2) is a process in which air is introduced into the compressor 1 so that pressure and temperature are increased through the compression process.

The temperature lowering process (2 → 3) is a compressed high-pressure, high-temperature air transfers heat to an external heat source through the first heat exchanger (3) and the temperature decreases under isostatic pressure (actually, a slight pressure drop). In this case, the high temperature heat transferred to the external heat source can be used as a heat source for heating the air conditioning space or obtaining hot water.

The expansion process (3 → 4) drops the pressure by using the expander 2 (a structure similar to a compressor) with the air having a lowered temperature, and the air temperature drops to below zero. At this time, the work extracted from the expander (2) can be used as a power for generating electricity or can be returned to the compressor (1) to help the compression work to reduce the power consumption of the compressor (1).

In the temperature increase process (4 → 1), the air having a lowered temperature and pressure passes through the second heat exchanger 4, and the temperature rises. At this time, the air absorbs heat from the air conditioning space, thereby performing a cooling (or freezing) role. Done.

In the above, the efficiency of the air cycle is highly dependent on the efficiency of the compressor 1 and the expander 2. In the past, the efficiency of the two components remained below about 80%, but the overall efficiency of the system was low. The overall efficiency is more than 80% due to the increase in the isentropic efficiency of this part.

In other words, when the efficiency of the compressor 1 is low, the power of the compressor 1 is increased, and the compression temperature is increased (see (1 → 2) in FIG. 2). This is because the cooling performance is reduced because it cannot be obtained (see (3 → 4) in Fig. 2).

Figure 3 is a cross-sectional view showing a conventional air compressor / inflator, Figure 4 is a perspective view of a conventional male rotor (before the description of the air compressor and expander is similar to the main components of the air compressor / expander in the following I list it.)

As shown, the air compressor / expander is axially coupled to the drive shaft 1a, and has a male rotor 1 having a spiral protrusion 1b on its outer surface, and a driven shaft 2a so as to be interlocked with the male rotor 1. The compressed air space is formed by the rotation of the female rotor 2 and the male rotor 1 and the female rotor 2, which are axially coupled and have a helical groove 2b corresponding to the protrusion 1b. The first and second flow ports 3a and 3b through which air is introduced and discharged are formed on both sides of the casing 3 at right angles to the shaft, and a sealing member 4 for closing both ends of the casing 3. And the end cover 5, the gear part 6 which is axially coupled to the driving shaft 1a and the driven shaft 2a on one side of the sealing cover 4, and transmits power, and the gear part 6 ) Is composed of a gearbox 7 covering.

In addition, a bearing 8 is axially coupled to the sealing member 4 and the end cover 5 to support rotation of the drive shaft 1a and the driven shaft 2a.

In addition, the oil seal 9 is coupled to the male rotor 1 and the female rotor 2 of the sealing member 4 to lubricate the gear part 6 and the bearing 8 installed in the gear box 7. It is made to prevent the lubricant from flowing into the casing (3).

In addition, the fixing nut 10 is coupled to the other side of the gear part 6 of the male rotor 1 and the female rotor 2 to connect the male rotor 1 and the female rotor 2 to the driving shaft 1a and the driven shaft. It is fixed.

The conventional air compressor / expander configured as described above drives the cycle in a state in which each is disposed on the air cycle.

In the above air compressor / expander, when the drive shaft 1a is rotated, the male rotor 1 coupled to the drive shaft 1a is rotated, and when the male rotor 1 is rotated, the arm coupled to the driven shaft 2a. The rotor 2 is rotated. The driving shaft 1a, the male rotor 1, the driven shaft 2a, and the female rotor 2 are respectively coupled to one end by a fixing nut 10 so that they are integrally rotated when driven. Done.

In addition, the air introduced through the first flow port 3a is compressed or expanded while the spiral of the male rotor 1 passes between the protrusion 1b and the spiral groove 2b of the female rotor, thereby expanding the second distribution port. Discharged through 3b constitutes a cycle.

In this case, in the case of an open type air cycle that directly supplies cool air to an air conditioning space, a human rotor must breathe the air itself, which is a refrigerant, so that contaminated air containing oil other than pure air cannot be used. ), The spiral protrusion 1b and the groove 2b of the arm rotor 2 should be designed in such a way as to minimize clearance between the rotors so that the grooves 2b of the arm rotor 2 do not contact each other. Otherwise, the efficiency of the compressor and expander will decrease, resulting in reduced system performance and efficiency.

For reference, most oil-injected screw compressors have a structure in which the rotors interlock with each other so that oil is injected and compressed to seal and cool the nasan acid on the rotor. Not applicable

However, the air compressor / expander as described above has the male rotor 1 and the female rotor 2 up and down due to the pressure change inside the casing 3 when the male rotor 1 and the female rotor 2 rotate. It is flowed, the gear part 6 for rotating the drive shaft (1a) and the driven shaft (2a) is made of a helical gear can reduce the backlash (backlash), but there is a problem that the play is generated by the thrust is generated.

That is, the helical protrusion 1b of the male rotor 1 and the helical groove 2b of the female rotor 2 are abraded by the clearance between the male rotor 1 and the female rotor 2. The problem is that the efficiency decreases due to the temperature rise and chipped chips pile up in the low pressure side space and are stuck (see Fig. 4).

Looking at this in more detail, when the rotor is moved upward in the drawing is formed a protruding jaw (6a) in the gear portion 6 coupled to the shaft can be prevented from contacting the inner ring of the bearing to the upper side, but downward If the play is not made of a structure that prevents play, the male rotor (1) and the protrusion (1b) and the groove (2b) of the female rotor is in contact with each other, in particular, the upper and lower bearings are sufficient when the rotor rotates at high speed Since the protruding portion 1b and the groove portion 2b are not easily interlocked, a lot of interference is generated.

In addition, the conventional air compressor / expander has a structure in which the upper bearing 8 does not come into contact with oil, so that heat generated from the bearing 8 during high-speed rotation is transferred to the air side inside the casing 3 as it is, thereby degrading performance. There is a problem.

In addition, the conventional air compressor / expander has a structure in which the flow of air is discharged through the first and second flow ports (3a) (3b) arranged in a line perpendicular to the axis, which is compressed or expanded air Considering that the traveling direction of the axial direction has a problem of lowering efficiency due to excessive pressure drop.

The present invention has been made to solve such a conventional problem, and an object thereof is a closed cover at both ends of a casing in which the male rotor and the female rotor are built in order to prevent a gap between the spiral protrusion of the male rotor and the spiral groove of the female rotor. It is arranged to provide an air compressor / inflator provided with a clearance preventing means on one side of the sealed cover.

In addition, another object of the present invention is to provide an air compressor / expander in which the air outlet is disposed at right angles to the shaft in order to minimize the pressure drop of the air.

The present invention for achieving this object is a shaft axially coupled to the drive shaft, the outer rotor having a helical protrusion on the outer surface, the arm is axially coupled to the driven shaft so as to interlock with the male rotor, the arm consisting of a helical groove corresponding to the protrusion First and second ends of the rotor, the casing for forming the compression or expansion space of the air by the rotation of the male rotor and the female rotor, the drive shaft and the driven shaft are installed in the axial direction, sealing both ends of the casing The male rotor or the female rotor disposed between the cover, the first and second end cover and the gear portion for transmitting power to the driving shaft and the driven shaft respectively coupled to any one of the first and second end cover; It is to include a clearance preventing means installed on the opposite side of the gear portion to prevent the clearance.

In addition, the clearance preventing means is to close the drive shaft or driven shaft end to the second end cover in close contact so that the male rotor or the female rotor does not have a clearance to the gear portion.

In addition, the clearance preventing means is one side is axially coupled to the center of the male rotor and the female rotor, the other side is a pair of T-type bushing coupled to the second end cover, and the second end cover and axially coupled to the T It is made of a bearing that one side is in contact with the mold bushing, the coupling member is fixed to both ends of the drive shaft and the driven shaft coupled to the bearing, it is made to form a constant gap between the gear portion and the first end cover.

In addition, a first flow port is formed on one surface of the casing, and is perpendicular to the first flow port and extends a second flow port in the axial direction of the drive shaft.

In addition, the rear and front covers are provided on the outer sides of the first and second end covers, respectively.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a perspective view of the combination of the air compressor / expander according to the present invention, Figure 6 is a cross-sectional view of the air compressor / expander according to the present invention, Figure 7 is a cross-sectional view taken along line AA of FIG.

As shown in the drawing, the air compressor / expander includes a male rotor 10, an arm rotor 20, a casing 30, first and second end covers 40 and 50, a gear unit 60, and a clearance preventing means 70. ).

The male rotor 10 is axially coupled to the drive shaft 11, the spiral protrusion 12 is formed on the outer surface.

The female rotor 20 is axially coupled to the driven shaft 21 so as to be interlocked with the male rotor 10, and is formed of a spiral groove 22 corresponding to the protrusion 12.

The casing 30 forms a compression or expansion space of air by the rotation of the male rotor 10 and the female rotor 20.

The first and second end covers 40 and 50 have the drive shaft 11 and the driven shaft 21 penetrated in the axial direction, and seal both ends of the casing 30.

In addition, between the first and second end covers 40 and 50 and the casing 30, an oil seal O that prevents oil from flowing into the casing 30 is driven between the drive shaft 11 and the driven shaft 21. ) Are combined.

In addition, the first and second end covers 40 and 50 are provided with bearings B for supporting rotation of the driving shaft 11 and the driven shaft 21, respectively, and in particular, the second end cover 50. At least two bearings (B) are preferably provided on the side to minimize vibration during high speed rotation of the drive shaft 11 and the driven shaft 21.

The gear part 60 is axially coupled to the driving shaft 11 and the driven shaft 21 on any one side of the first and second end covers 40 and 50 to transmit power. One end cover 40 is provided on the side, the gear portion 60 is made of a helical gear is made to prevent backlash.

The clearance preventing means 70 of the gear unit 60 to prevent the clearance between the male rotor 10 and the female rotor 20 disposed between the first and second end covers 40 and 50. It is installed on the opposite side, one side is axially coupled to the center of the male rotor 10 and the female rotor 20, the other side is a pair of T-type bushing 71 is coupled to the second end cover 50, A bearing B which is axially coupled to the second end cover 50 and whose one side is in contact with the T-shaped bushing 71, and the drive shaft 11 and driven shaft 21 to which the bearing B is coupled. It is made of a coupling member 72 for fixing both ends of the, to form a predetermined interval between the gear portion 60 and the first end cover (40).

In addition, one side of the gear unit 60 is formed with a projection jaw 61 is preferably separated from the bearing (B) coupled to the first end cover 40 at a predetermined interval.

That is, the bearing B coupled to the protruding jaw 61 of the gear part 60 and the first end cover 40 is spaced at a predetermined interval so that the driving shaft 11 and the driven shaft 21 are fixed, and On the opposite side, the male rotor 10 and the female rotor 20 inside the casing 30 are constrained by thrust prevention means 70 composed of a T-shaped bushing 71, a bearing B, and a coupling member 72, and thrust. Even if this occurs, play does not occur.

Meanwhile, the male rotor 10 and the female rotor 20 which are in contact with the first end cover 40 further have an annular bushing 73 which is axially coupled on the driving shaft 11 and the driven shaft 21, and there is a clearance. It can prevent more.

In addition, a rear cover 80 is installed outside the gear part 60 to seal the gear part 60, and the rear cover 80 supports the drive shaft 11 and the driven shaft 21. The bearing B is fixed and the oil seal O is installed in the drive shaft 11 penetrated through the rear cover 80.

As described above, the respective bearings B and the like that support the gear unit 60, the drive shaft 11, and the driven shaft 21 by the rear cover 80 can be lubricated by oil, and the oil seal O By blocking the inflow of oil to the casing 30 by the side, only the air in the casing 30 is compressed or expanded.

In addition, a front cover 90 is installed at the second end cover 50 side and a through hole 51 is formed so that the air compressed or expanded in the casing 30 is installed outside the front cover 90. It is to be discharged or sucked into the second distribution port (91).

In other words, a second flow port 91 corresponding to the first flow port 31 formed on one surface of the casing 30 is installed on the front cover 90 in the axial direction.

Here, when the air compressor / expansion machine of the present invention is used as an air compressor, the first flow port 31 becomes the intake port, and the second flow port 91 becomes the discharge port. The sphere 91 serves as a suction port, and the first flow port 31 serves as a discharge port.

Referring to the operation according to the invention in detail as follows.

The male rotor 10 is coupled to the drive shaft 11, the female rotor 20 is coupled to the driven shaft 21, and the male rotor 10 and the female rotor 20 are disposed in the casing 30. do.

 Further, first and second end covers 40 and 50 are installed at both ends of the casing 30, respectively, and bearings B, oil seals O and annular bushings are provided on the first end cover 40 side. The shafts are coupled to each other, and the ends of the driving shaft 11 and the driven shaft 21 in the state in which the T-type bushing 71 oil seal O and the bearing B are axially coupled to the second end cover 50 side are coupled members ( 72).

In addition, the protruding jaw 61 and the bearing B of the gear part 60 provided on one side of the driving shaft 11 and the driven shaft 21 are preferably spaced apart from each other.

As described above, the driving shaft 11 and the driven shaft 21 are axially coupled, and the male rotor 10 and the female rotor 20 disposed inside the casing 30 have one side of the bearing B of the gear part 60. And the other side is fixed by the play prevention means 70, that is, the T-type bushing 71, the bearing B and the coupling member 72, so that the spiral of the male rotor 10 at high speed rotation is supported. Since the protrusions 12 and the spiral grooves 22 of the arm rotor 20 do not interfere, wear and the like are not generated to improve cooling ability.

In addition, the rear cover 80 is fixed to the first end cover 40 side, and the front cover 90 is installed on the second end cover 50, and a second distribution port provided on the front cover 90 is provided. Air is sucked in and discharged through the first flow port 31 provided in the 91 and the casing 30.

Referring to the flow of air when using the air compressor / expander of the present invention as described above in the air, the first flow port 31, that is, the air is introduced through the inlet, the introduced air is inside the casing 30 It is compressed while passing through the spiral projection 12 and the spiral groove portion 22 between the male rotor 10 and the female rotor 20, the compressed air is front through the through hole of the second end cover 50 Air is discharged from the second flow port 91 of the cover 90, that is, the discharge port.

In this process, the male rotor 10 and the female rotor 20 are fixed to the play shaft 11 and the driven shaft 21 so as not to be free from the thrust.

In addition, when the air flow when using the air compressor / expander of the present invention as an air inflator described above, the second flow port 91 of the front cover 90 of the second end cover 50, that is, Air is introduced through the inlet, and the introduced air is expanded while passing through the spiral protrusion 12 and the spiral groove 22 between the male rotor 10 and the female rotor 20 inside the casing 30, The expanded air discharges air to the first flow port 31 of the casing 30, that is, the discharge port.

The air compressor / expander according to the present invention as described in detail above arranges the end covers at both ends of the casing in which the male rotor and the female rotor are built, and installs a clearance preventing means at one side of the end cover to form a spiral protrusion of the male rotor. And play between the spiral groove of the arm rotor can be prevented.

In addition, the air compressor / expander according to the present invention can minimize the pressure drop of the air by arranging a pair of air outlet in a direction perpendicular to each other.

Claims (5)

A male rotor 10 axially coupled to the drive shaft 11 and having a spiral protrusion 12 on its outer surface; An arm rotor 20 axially coupled to a driven shaft 21 so as to be interlocked with the male rotor 10, and having a spiral groove 22 corresponding to the protrusion 12; Casing 30 to form a compression or expansion space of air by the rotation of the male rotor 10 and the female rotor 20, First and second end covers 40 and 50 through which the drive shaft 11 and the driven shaft 21 penetrate in the axial direction and seal both ends of the casing 30; A gear unit 60 which is axially coupled to the driving shaft 11 and the driven shaft 21 on any one side of the first and second end covers 40 and 50, and transmits power; Gap preventing means installed on the opposite side of the gear portion 60 to prevent the play of the male rotor 10 or the female rotor 20 disposed between the first and second end covers 40, 50 ( 70) air compressor / expander. The driving shaft 11 or the driven shaft 21 of claim 1, wherein the clearance preventing means 70 does not have clearance between the male rotor 10 or the female rotor 20 toward the gear unit 60. Air compressor / inflator, characterized in that the end is fixed to the second end cover 50 in close contact According to claim 1, wherein the clearance preventing means 70, One side is axially coupled to the center of the male rotor 10 and the female rotor 20, the other side is a pair of T-type bushing 71 is coupled to the second end cover 50, A bearing (B) axially coupled to the second end cover (50) and one side of which is in contact with the T-type bushing (71); It consists of a coupling member 72 is fixed to both ends of the drive shaft 11 and the driven shaft 21 is coupled to the bearing (B), Air compressor / inflator, characterized in that to form a constant interval between the gear portion 60 and the first end cover (40). According to claim 1, wherein the first flow port 31 is formed on one surface of the casing 30, perpendicular to the first flow port 31, and the second flow port in the axial direction of the drive shaft (11) An air compressor / expander, characterized in that the extension 91 is formed. The air compressor / expansion device according to claim 1, wherein rear and front covers (80, 90) are provided outside the first and second end covers (40) (50), respectively.

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