KR20060032340A - Gear type compressor - Google Patents

Abstract

The present invention relates to a compressor of a gear type that can improve the performance coefficient of the refrigeration system, in particular to improve the internal gear structure to increase the oil storage space instead of reducing the contact area to reduce the friction of the contact portion. .

To this end, the present invention and the casing having an internal space of a predetermined size; A motor installed inside the casing; A gear type compression unit configured to compress the refrigerant introduced from the evaporator by receiving the driving force of the motor; And a gear type expansion unit for expanding the refrigerant re-sucked through the condenser after being discharged from the compression unit, wherein the gear type compression unit comprises: a main bearing fixed to the lower side of the motor; An annular compression cylinder connected to the lower part of the main bearing; An external gear rotatably positioned in the compression cylinder inner space; An internal gear installed inside the external gear to compress the refrigerant while being engaged with the external gear by receiving the driving force of the motor; Comprising a compression plate is installed in contact with the lower portion of the compression cylinder, the gear-type expansion portion, the expansion plate is installed on the lower compression plate of the gear-type compression portion; An annular expansion cylinder connected to the lower portion of the expansion plate; An external gear rotatably positioned in the expansion cylinder inner space; An internal gear installed inside the external gear to expand the refrigerant while being engaged with the external gear by receiving the driving force of the motor; A gear type compressor comprising a sub-bearing connected to the lower portion of the expansion cylinder, the inlet groove is formed on the surface of the compression unit or the inner gear of the expansion portion to reduce the contact area with other components and to function as an oil storage space. Is provided.

Compressor, internal gear, compression, expansion, contact surface, oil

Description

Gear type compressor

1 is a conceptual diagram showing the configuration of a typical refrigeration system

2 is a graph showing a P-h diagram of the refrigeration system of FIG.

3 is a cross-sectional view showing the configuration of a gear type compressor according to the present invention.

4A is a cross-sectional view along the line I-I of FIG.

4B is a cross-sectional view along the line II-II of FIG. 3.

Figure 5a is a plan view of the inner gear of the compression unit

Figure 5b is a plan view of the inner gear of the expansion portion

FIG. 6A is a cross-sectional view along line III-III of FIG. 5A

FIG. 6B is a cross-sectional view taken along line IV-IV of FIG. 5B

7 is a configuration diagram of a refrigeration system to which the gear type compressor of the present invention is applied;

8 is a graph comparing the torque change generated by the compressor of the present invention with the torque generated by the conventional compressor.

9 is a plan view and a cross-sectional view showing another embodiment of the internal gear of the present invention.

* Description of the symbols for the main parts of the drawings *

1: Casing 100: suction pipe

110: power terminal 120: base plate                 

2: motor 200: stator

210: rotor 220: shaft

3: Compression part 300: Main bearing

300a: suction port 310: compression cylinder

320: External gear 320a: Teeth groove

330: Internal gear 330 g: Recessed groove

330g-1: Indentation groove 330a: Teeth

340: compression plate 340a: discharge port

350: compressed part suction pipe 360: compressed part discharge pipe

4: expansion part 400: expansion plate

410: expansion cylinder 420: external gear

420a: Teeth groove 430: Internal gear

430 g: Indentation groove 430a: Teeth

440: sub bearing 440a: suction port

440b: discharge port 450: inflatable suction pipe

460: expansion part discharge pipe

5: condenser 6: evaporator

The present invention relates to a compressor, and more particularly to a compressor of the gear type.

In general, a compressor is a machine that increases the pressure of a working fluid by receiving power from a power generator such as an electric motor or a turbine and applying compression work to air, a refrigerant, or other special gas. It is widely used in general household appliances such as the field to the plant industry.

On the other hand, such compressors are classified into positive displacement compressors and dynamic compressors or turbo compressors according to the compression method.

Among them, a widely used industrial compressor is a volumetric compressor, which has a compression method of increasing pressure through volume reduction. The volumetric compressor is further classified into a reciprocating compressor and a rotary compressor.

The reciprocating compressor compresses the working fluid by a piston reciprocating linearly inside the cylinder, and has a merit of obtaining a high compression efficiency with a relatively simple mechanical element. On the other hand, the size and weight of the machine is increased, the reciprocating compressor has a limitation in the rotational speed due to the inertia of the piston, there is a disadvantage that significant vibration occurs due to the inertia force.

The rotary compressor compresses the working fluid by a roller revolving with the eccentricity inside the cylinder, and a high compression efficiency can be obtained at a low speed compared to the reciprocating compressor.

However, in order to change the flow rate at a constant rotational speed, the rotary compressor needs to discharge extra air or throttle the intake air, and to provide a stabilizer in order to increase the discharge pressure caused by the extra air. It becomes difficult.

In addition, if the gap between the parts is not very uniform, compressed gas may leak and may not be able to exert its performance. Thus, highly precise machining is required. In addition, the bearing load is easily damaged due to the acting load due to the rapid pressure change.

That is, the rotary compressor and the reciprocating compressor have different characteristics and advantages and disadvantages, respectively.

On the other hand, a refrigeration cycle is a thermodynamic cycle, when the purpose of extracting heat to the cold reservoir by applying work (working) is called a refrigeration cycle (refrigeration cycle), the system forming the refrigeration cycle is a refrigeration cycle It is called a system and it is mainly used in refrigerators and air conditioners.

In addition, referring to FIG. 1, the refrigerating system extracts heat from a compressor 30 that compresses the refrigerant at a high temperature and high pressure, and extracts heat from the refrigerant compressed by the compressor 30 to the outside to make the refrigerant into a liquid state. A condenser 50, an expansion valve 40 for adiabatic expansion of the refrigerant flowing from the condenser 50, and a pressure drop, and the refrigerant passing through the expansion valve 40 to a low pressure gas while absorbing external heat. Consisting of an evaporator 60.                         

For reference, FIG. 2 is a graph showing the pH diagram of the refrigeration system of FIG. 1, which receives the work (Wc) from the outside to compress the refrigerant in the compressor 30 (1 → 4), and compresses in the compressor 30. The refrigerant is released through the condenser 50 to the heat of the refrigerant to the outside (2 → 3).

The refrigerant passing through the condenser 50 is adiabaticly expanded while passing through the expansion device 20 (3 → 4), and the refrigerant passing through the expansion device receives external heat while passing through the evaporator 60. (4 → 1), the refrigerant passing through the evaporator 60 flows back into the compressor (30).

The coefficient of performance (COP) of this refrigeration system is defined as the compressor work (Wc) for the amount of heat Q _H absorbed by the low temperature section, that is, the evaporator 60.

Therefore, in order to construct an efficient refrigeration system, it is necessary to configure an efficient compressor with an appropriate refrigerant selection.

In recent years, the necessity of alternative refrigerants such as CO2 is very important as the problem of freon gas, which is a refrigerant, destroys the ozone layer.In this case, even when using an alternative refrigerant, there is no fear of leakage during compression, and mechanical reliability is secured. A compressor is needed.

In view of the above needs of the present invention, the present invention relates to a gear-type compressor that can improve the coefficient of performance of the refrigeration system, and in particular, the oil storage space is reduced instead of reducing the contact area of the internal gear structure. An object of the present invention is to provide a gear-type compressor that can reduce friction of the contact by improving the structure to increase.

In order to achieve the above object, the present invention and the casing having an internal space of a predetermined size; A motor installed inside the casing; A gear type compression unit configured to compress the refrigerant introduced from the evaporator by receiving the driving force of the motor; And a gear-type expansion part for expanding the refrigerant re-absorbed through the condenser after being discharged from the compression part.

The gear type compression unit, the main bearing is fixed to the lower side of the motor; An annular compression cylinder connected to the lower part of the main bearing; An external gear rotatably positioned in the compression cylinder inner space; An internal gear installed inside the external gear to compress the refrigerant while being engaged with the external gear by receiving the driving force of the motor; It comprises a compression plate that is connected to the lower portion of the compression cylinder,

The gear-type expansion unit, the expansion plate which is installed under the compression plate of the gear-type compression unit; An annular expansion cylinder connected to the lower portion of the expansion plate; An external gear rotatably positioned in the expansion cylinder inner space; An internal gear installed inside the external gear to expand the refrigerant while being engaged with the external gear by receiving the driving force of the motor; It is made to include a sub-bearing that is connected to the lower portion of the expansion cylinder,

A gear type compressor is provided on the inner gear surface of the compression section or the expansion section to reduce the contact area with other parts and to form a recess groove which functions as an oil storage space.

At this time, the recess groove may be selectively formed on the upper or lower surface of the inner gear, it is more preferably formed on both sides.

In addition, the recess groove is formed to have a profile of the same shape as the outer profile of the inner gear.

On the other hand, the width (W) of the outer recessed groove of the inner gear may be formed differently depending on the peak portion and the valley portion of the inner gear.

And, the depth (D) of the recess groove is characterized in that it is formed within 200㎛.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, FIGS. 3 to 10.

3 is a cross-sectional view showing the configuration of a gear-type compressor according to the present invention, Figure 4a is a cross-sectional view along the line I-I of Figure 3, Figure 4b is a cross-sectional view along the line II-II of FIG.

5A is a plan view of the inner gear of the compression unit, FIG. 5B is a plan view of the inner gear of the expansion unit, FIG. 6A is a cross-sectional view taken along the line III-III of FIG. 5A, and FIG. to be.

On the other hand, Figure 7 is a block diagram of a refrigeration system to which the gear type compressor of the present invention is applied, Figure 8 is a graph comparing the torque generated in the compressor of the present invention with the torque generated in the conventional compressor.                     

Referring to this, the gear-type compressor of the present invention, the casing (1) having a predetermined space therein; A motor 2 installed inside the casing 1; A gear type compression unit 3 which receives the driving force of the motor 2 and compresses the refrigerant introduced from the evaporator 6; And a gear type expansion part 4 for discharging the refrigerant re-sucked through the condenser 5 after being discharged from the compression part 3.

At this time, the motor 2, the stator 200 mounted on the inner wall of the casing (1) and the rotor 210 is rotated when the power is applied to the stator 200 through the power terminal 110 is installed in the center thereof. Is made of.

The gear type compression unit 3 includes a main bearing 300 fixed to the motor lower side of the casing 1; An annular compression cylinder 310 connected to the lower part of the main bearing 300; An external gear 320 rotatably positioned in an inner space of the compression cylinder 310; An inner gear 330 installed inside the outer gear 320 to compress the refrigerant while being engaged with the outer gear 320 by receiving the driving force of the motor 2; It includes a compression plate 340 is installed in contact with the lower portion of the compression cylinder (310).

At this time, one side of the casing (1) is provided with a suction pipe 100 (suction pipe) for the refrigerant flow into the casing (1).

In addition, a base plate 120 for installing a compressor is provided below the casing 1.

In addition, the main bearing 300 sucks the compression portion connected to the main bearing 300 to send the refrigerant flowing into the casing 1 to the inner space of the external gear 320 through the compression cylinder 310. A pipe 350 (sub compression suction pipe) is installed, and the compression plate 340 is provided with a compression discharge pipe 360 (compression discharge pipe) for sending the compressed refrigerant to the condenser (5).

At this time, the compression unit suction pipe 350 is installed to be exposed on the liquid level of the oil (oil) filled in the casing (1).

That is, the oil of the upper and lower portions of the compression unit 3 is not separately filled, but is drawn to have a length in the vertical direction on the outer circumferential surfaces of the compression cylinder 310, the main bearing 300, and the compression plate 340. It communicates with each other through the groove (3g).

On the other hand, the gear-type expansion unit 4, the expansion plate 400 is installed below the compression plate 340 of the gear-type compression unit (3); An annular expansion cylinder 410 which is installed to be connected to the lower portion of the expansion plate 400; An external gear 420 rotatably positioned in an inner space of the expansion cylinder 410; An inner gear 430 installed inside the outer gear 420 to expand the refrigerant while being engaged with the outer gear 420 by receiving the driving force of the motor; It comprises a sub-bearing 440 is installed in contact with the expansion cylinder 410 lower portion.

In addition, an expansion suction pipe 450 is installed at one side of the sub-bearing 440 to allow the refrigerant passing through the condenser 5 to flow into the expansion cylinder 410.

And, the other side of the sub-bearing 440 is provided with an expansion discharge pipe 460 (expander discharge pipe) for sending the expanded refrigerant to the evaporator (6).                     

In addition, a suction port 300a is formed in the main bearing 300, and a discharge port 340a is formed in the compression plate 340.

In addition, a suction port 440a and a discharge port 440b are formed at predetermined positions in the sub bearing 440.

On the other hand, the outer size of the inflation portion 4 is formed to a size smaller than the outer size of the compression portion (3).

That is, the outer size of the sub-bearing 440, the expansion cylinder 410 and the expansion plate 400 is formed in a smaller size than the outer size of the main bearing 300, the compression cylinder 310 and the compression plate 340 desirable.

Accordingly, the compression unit discharge pipe 360 connection to the compression plate 340 constituting the gear type compression unit 3 can be easily made.

On the other hand, the reason why the outer size of the gear-type expansion part 4 can be formed in a smaller size than the outer size of the compression part 3 is that the gear size of the expansion part 4 is the gear size of the compression part 3. Because it is small compared to.

This is due to the specific volume difference between the refrigerant flowing into the suction port 300a in the compression unit 3 and the refrigerant flowing into the suction port 440a in the expansion unit 4, Since the specific volume of the refrigerant flowing into the suction port 440a is small, in order for the mass flow of the expansion process and the compression process to achieve the same mass flow rate, the administrative volume of the expansion process must be smaller than the administrative volume of the compression process. This is because the gear size of the inflation section 4 must be smaller than the gear size of the compression section 3.                     

However, the difference in gear size does not have a direct relationship with the difference in external size of the compression cylinder 310 and the expansion cylinder 410.

On the other hand, the upper and lower surfaces of the internal gear 330 of the compression unit 3, and the upper and lower surfaces of the internal gear 430 of the expansion unit 4 Recessed grooves 330g and 430g are respectively formed to reduce the contact area with other parts and to function as oil storage spaces.

In this case, the recessed grooves 330g and 430g may be selectively formed on the upper or lower surface of the inner gears 330 and 430, and more preferably formed on both surfaces thereof.

In addition, the recessed grooves 330g and 430g are formed to have the same or similar profile as the outer profile of the inner gears 330 and 430.

And, the depth (D) of the recessed grooves (330g) (430g) is characterized in that it is formed within 200㎛.

On the other hand, the width (W1) (W2) of the outer peripheral grooves (330g, 430g) of the inner gears (330, 430) may be formed differently depending on the peaks and valleys of the inner gears (330, 430). This is to increase the rigidity of the portion that takes more force of the mountain portion and the bone portion of the inner gear 330.

Hereinafter, the operation of the compressor of the present invention configured as described above will be described with reference to FIGS. 3 to 8.

First, referring to FIGS. 3 and 7, the refrigerant is compressed in the gear type compression unit 3 according to the operation of the motor 2, and the refrigerant compressed in the compression unit 3 is then condenser along the flow path. Inflow to the (5), the heat is discharged to the outside while passing through the condenser (5).

In addition, the refrigerant passing through the condenser 5 is introduced into the expansion part 4 of the compressor of the present invention through the flow path, and the refrigerant introduced into the expansion part 4 expands in the process of passing through the expansion part.

Subsequently, the refrigerant passing through the expansion part 4 flows into the evaporator 6, and the refrigerant absorbs heat from the outside while passing through the evaporator 6.

Then, the refrigerant passing through the evaporator 6 flows back into the compression unit 3, and this series of flows is repeated to form a refrigeration cycle.

When described in more detail with reference to Figure 3 the compression and expansion action performed by the compressor of the present invention during the process of forming a refrigeration cycle as described above.

First, when power is applied to a motor mounted on the inner wall of the casing 1 and the rotor 210 rotates by electromagnetic interaction with the stator 200, the suction pipe 100 installed at the upper end of the casing 1 (suction) The refrigerant flows into the casing 1 through the pipe.

In addition, the refrigerant introduced into the casing 1 is sent to the inner space of the external gear 320 through a sub compression suction pipe 350 connected to the main bearing 300.

At this time, the refrigerant passing through the compression portion suction pipe 350 is introduced into the inner space of the outer gear 320 through the suction port 300a of the main bearing 300 in communication with the inner space of the outer gear 320.

In addition, the refrigerant sent to the inner space of the external gear 320 is gradually compressed according to the rotation of the inner gear 330 axially coupled to the motor shaft 220, and then passes through the discharge port 340a formed in the compression plate 340. It is discharged through the compression part discharge pipe 360 connected to the discharge port 340a and sent to the condenser 5.

Here, the area of the discharge port 340a in the compression unit 3 is smaller than that of the suction port 300a.

Meanwhile, the refrigerant that has undergone the heat exchange process in the condenser 5 is re-introduced into the gear type expansion part 4 of the compressor of the present invention.

That is, the refrigerant having undergone the heat exchange in the condenser 5 passes through the expansion part suction pipe 450 connected to one side of the sub bearing 440, and then the external gear 420 through the suction port 440 a of the sub bearing 440. The refrigerant flowing into the inner space and sent to the inner space of the outer gear 420 is gradually expanded according to the rotation of the inner gear 430 axially coupled to the motor shaft 220 and then discharged to the other side of the sub bearing 440. It is discharged through the expansion part discharge pipe 460 connected to the port 440b is sent to the evaporator (6).

Here, the area of the discharge port 440b in the expansion part 4 is larger than that of the suction port 440a.

On the other hand, the gear-type compression unit 3 and the gear-type expansion unit 4 is preferably all installed in one casing (1), as in the above-described embodiment, each separately installed in a separate casing (1) May be

In addition, the motor 2 may also be installed outside the casing 1, and any driving device can be used as the driving means.                     

On the other hand, Figure 4a is a cross-sectional view along the line I-I of Figure 3, illustrating the geometry of the inner gear 330 and the outer gear 320 forming the compression section (3).

At this time, the outer gear 320 is formed to have more teeth grooves 320a than the number of teeth 330a of the inner gear 330 that is coupled to the motor shaft 220 and rotates of the inner gear 330. The center of rotation of the center and the outer gear 320 is installed eccentrically.

Typically, the teeth 330a of the inner gear 330 are smaller than the number of the tooth grooves 320a of the outer gear 320, and the shape of the teeth 330a preferably forms a cycloid curve.

4B is a cross sectional view taken along the line II-II of FIG. 3, and illustrates the geometric shapes of the inner gear 430 and the outer gear 420 constituting the expansion part 4. The structures of the inner gear 430 and the outer gear 420 of the expansion part 4 are the same as the structures of the inner gear 330 and the outer gear 320 of the compression part 3, and only differ in size.

On the other hand, as shown in Figures 5a to 6b, the gear type compressor of the present invention is the upper and lower inner gear 330 of the compression section 3, and the upper and lower inner gear 430 of the expansion section (4). The lower surface is formed with a recess groove (330g) having an outer profile and the same profile of the inner gear, it is possible to reduce the contact area between each of the inner gear and the other parts and to secure the oil storage space.

In addition, the concave groove 330g configured as described above reduces the contact area, and the oil stored in the concave groove 330g not only reduces friction but also performs a thrust bearing function that withstands axial load.

In addition, the reduction of the frictional resistance makes it possible to reduce the input value input to the motor 2, thereby increasing the energy consumption efficiency of the compressor.

On the other hand, Figure 8 is a graph comparing the torque change generated in the compressor of the present invention with the torque generated in the conventional compressor, the vertical axis is the torque ratio divided by each torque value (T) by the average value (Tm) of the torque generated during rotation. The horizontal axis represents the rotation angle.

Referring to this, it can be seen that the amount of torque change generated when the refrigerant is compressed by the compressor according to the structure of the present invention is significantly smaller than that of the compression device having another structure.

For example, it can be seen that the compressor according to the structure of the present invention is significantly less torque change than the reciprocating compressor.

In particular, in the gear type compressor of the present invention, vibration and noise are reduced by maintaining torque balance as the external gears 320 and 420 rotate together with the inner gears 330 and 430 when the refrigerant is compressed and expanded. .

In addition, in the gear type compressor of the present invention, the teeth 330a and 430a formed in the inner gears 330 and 430 and the teeth grooves 320a and 420a of the outer gears 320 and 420 are contacted with each other. Therefore, there is an effect that the force transmitted from the inner gear to the outer gear is dispersed without being concentrated in one place.

In addition, the gear type compressor of the present invention at the point where the teeth 330a, 430a formed in the inner gears 330, 430 and the teeth grooves 320a, 420a of the outer gears 320, 420 are engaged. Speed difference, i.e., the relative speed is small.

On the other hand, the gear type compressor of the present invention can be used as a refrigerant carbon dioxide refrigerant.

Carbon dioxide has a long service life as a refrigerant, is not toxic and nonflammable. In addition, the price is low, the source is abundant, there is no need to recover, it can be dissolved well with lubricating oil, and the amount of cooling per unit volume is five times higher than that of CFC series R-22. Compression ratio also has the advantage of being smaller.

Therefore, when using the gear type compressor of the present invention it is possible to fully utilize the above advantages by using carbon dioxide as a refrigerant.

On the other hand, Figure 9 is a plan view and a cross-sectional view showing another embodiment of the inner gear of the present invention, the shape of the recessed groove (330g-1) formed on the outer surface of the inner gear 330 of the compression section (3) of the inner gear It shows the case of forming an annulus without following the outer profile. Although the figure shows the inner gear of the compression part as an example, the recess groove of this structure is equally applied to the inner gear of the expansion part.

That is, the recessed groove 330g-1 has an annular shape, and the outer diameter of the recessed groove 330g-1 is smaller than the diameter of the valley of the inner gear.

In this case, too, the recessed groove 330g-1 may achieve the same contact area reduction and oil storage effect as in the above-described embodiment.

As described above, the present invention can provide a gear-type compressor, it is possible to improve the performance coefficient of the refrigeration system.

On the other hand, according to the present invention, it is possible to replace the refrigerant used in the compressor with carbon dioxide, there is an advantage that the environmentally friendly compressor can be implemented.

That is, carbon dioxide has a long service life as a refrigerant, not only toxic but also nonflammable. In addition, the price is low, the source is abundant, there is no need to recover, it can be dissolved well with lubricating oil, and the amount of cooling per unit volume is five times higher than that of CFC series R-22. Compression ratio also has the advantage of being smaller.

In addition, the gear-type compressor of the present invention has the advantage of reducing the vibration and noise when operating the compressor due to the balance of the torque of the internal gear and the external gear.

On the other hand, the present invention is to form a recess groove in the inner gear surface to reduce the contact area and to store the oil to prevent mechanical loss due to friction on the contact surface and further increase the energy consumption efficiency of the compressor.

Claims (8)

A casing having a predetermined size space therein; A motor installed inside the casing; A gear type compression unit configured to compress the refrigerant introduced from the evaporator by receiving the driving force of the motor; And a gear-type expansion part for expanding the refrigerant re-absorbed through the condenser after being discharged from the compression part. The gear type compression unit, the main bearing is fixed to the lower side of the motor; An annular compression cylinder connected to the lower part of the main bearing; An external gear rotatably positioned in the compression cylinder inner space; An internal gear installed inside the external gear to compress the refrigerant while being engaged with the external gear by receiving the driving force of the motor; It comprises a compression plate that is connected to the lower portion of the compression cylinder, The gear-type expansion unit, the expansion plate which is installed under the compression plate of the gear-type compression unit; An annular expansion cylinder connected to the lower portion of the expansion plate; An external gear rotatably positioned in the expansion cylinder inner space; An internal gear installed inside the external gear to expand the refrigerant while being engaged with the external gear by receiving the driving force of the motor; It is made to include a sub-bearing that is connected to the lower portion of the expansion cylinder, Gear-type compressor characterized in that the concave groove is formed on the surface of the inner gear of the compression unit or expansion unit to reduce the contact area with other parts and function as an oil storage space. The method of claim 1, The recess groove is a gear type compressor, characterized in that formed selectively on the upper or lower surface of the inner gear. The method of claim 1, The recess groove is a gear type compressor, characterized in that formed on the upper and lower surfaces of the inner gear at the same time. The method according to any one of claims 1 to 3, The recess groove is a gear type compressor, characterized in that it is formed to have a profile that is the same or similar to the outer profile of the inner gear. The method of claim 1, The thickness of the recess groove is a gear type compressor, characterized in that formed within 200㎛. The method of claim 1, The width (W) of the outer groove of the recessed groove of the inner gear is a gear type compressor, characterized in that it is formed differently depending on the peak portion and the valley portion of the inner gear. The method according to any one of claims 1 to 3, The recess groove is a gear-type compressor, characterized in that to form an annular. The method of claim 7, wherein The outer diameter of the recess groove is a gear-type compressor, characterized in that to form a dimension smaller than the diameter of the bone portion of the inner gear.

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