KR100556413B1 - gear type compressor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear type compressor, and more particularly, to a coupling structure of a shaft of a motor and internal gears of each of the compression and expansion portions.

To this end, the present invention is a motor, a gear-type compression unit for compressing the refrigerant flowing from the evaporator receives the driving force of the motor, and a gear-type expansion unit for expanding the refrigerant re-absorbed through the condenser after discharged from the compression unit Including but not limited to

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 is fixed to the lower side of the motor; 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,

The inner gear of the gear-type compression unit and the inner gear of the gear-type expansion unit provide a gear-type compressor, characterized in that coupled to the shaft of the motor in a fitting manner.

Gear, Compressor, Internal Gear, External Gear, Compression, Expansion

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 taken along the line II of FIG. 3.

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

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

Figure 6 is a graph comparing the torque change generated in the compressor of the present invention with the torque generated in the conventional compressor

* 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

221: Combination key 3: Compression part

300: Main bearing 300a: Suction port

310: Compression cylinder 310h: Oil supply hole

320: External gear 320a: Teeth groove

330: Internal gear 331: Keyway for coupling

330a: Teeth 340: Compression Plate

340a: discharge port 350: compression suction pipe

360: compression part discharge pipe 4: expansion part

400: expansion plate 410: expansion cylinder

410h: Oil supply hole 420: External gear

420a: Teeth groove 430: Internal gear

430a: Teeth 431: Combination Keyway

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 coupling structure of a drive shaft and an internal gear of a gear type compressor.

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 for increasing pressure through a 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 can obtain a high compression efficiency 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, the refrigeration cycle is a kind of thermodynamic cycle, when it is intended to extract heat to the cold reservoir by applying a work (refrigeration cycle), which constitutes the refrigeration cycle The system is called a refrigeration system and is mainly used for 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).

In addition, 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 passes through the evaporator 60 to cool external heat. (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.

The present invention has been made in view of the above-described necessities, and provides a compressor having a new structure that can improve the performance coefficient of a refrigeration system different from the existing compressor structure. The purpose is to transfer the driving force of the motor through the motor shaft more accurately and easily by connecting the coupling structure between the inner gear and the inner gear constituting the expansion portion in the structure of the key and the key groove.

In order to achieve the above object, the present invention provides a motor, a gear-type compression unit for compressing the refrigerant introduced from the evaporator receives the driving force of the motor, and expands the refrigerant re-absorbed through the condenser after discharged from the compression unit Is made to include a gear-type inflation,

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 is fixed to the lower side of the motor; 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,

The inner gear of the gear-type compression unit and the inner gear of the gear-type expansion unit provide a gear-type compressor, characterized in that coupled to the shaft of the motor in a fitting manner.

Here, the shaft of the motor is provided with a coupling key and corresponding to the inner gear of the gear-type compression unit and the inner gear of the gear-type expansion unit is provided with a coupling key groove, respectively, the coupling key groove of the respective inner gear The inner gear is rotated by receiving the rotational force of the motor through the shaft of the motor by coupling the coupling key of the motor rotation shaft.

The height of the coupling key is smaller than the thickness of the inner gear corresponding thereto.

And, the coupling key groove is provided with at least one in each of the inner gear, the coupling key is characterized in that provided in the number corresponding to the coupling key groove.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, FIGS. 3 to 6.

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.

And, Figure 5 is a block diagram of a refrigeration system to which the gear type compressor of the present invention is applied.

A gear type compressor of the present invention includes a 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.
Here, the power terminal 110 is provided on the upper surface of the casing (1), one side is connected to the stator 200 and the other side is connected to an external power line, to apply power to the stator 200.
Therefore, when power is applied to the stator 200 through the power terminal 110, the rotor 210 is rotated by the electromagnetic action with the stator 200.

The gear type compression unit 3 (ie, the compression unit) includes a main bearing 300 fixed to the lower side of the motor 2 in 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).

In addition, a suction pipe 100 (suction pipe) is installed at one side of the casing 1 to introduce refrigerant 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 has a compression-negative suction pipe connected to the main bearing 300 to send the refrigerant introduced into the casing 1 to the inner space of the external gear 320 through the compression cylinder 310. A sub compression suction pipe 350 is installed, and the compression plate 340 is provided with a compression discharge pipe 360 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 in the upper and lower portions of the compression part is not separately filled, but the grooves 3g are formed to have lengths in the vertical direction on the outer circumferential surfaces of the compression cylinder 310, the main bearing 300 and the compression plate 340. Through each other through the exchange is possible.

On the other hand, the gear-type expansion unit 4 (that is, the expansion unit), the expansion plate 400 which 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 2; 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 coupling shaft 221 is formed on the shaft 220 of the motor and corresponding to the inner gear 330 of the gear-type compression unit 3 and the inner gear of the gear-type expansion unit 4 ( 430 has coupling key grooves 331 and 431 corresponding to the coupling key 221, respectively, and the motors are provided in the coupling key grooves 331 and 431 of the respective inner gears 330 and 430. As the coupling key 221 of the shaft 220 is coupled, each of the inner gears 330 and 430 is rotated by receiving the rotational force of the motor through the motor shaft 220.

In addition, the height h of the coupling key 221 may be smaller than the thickness t of the inner gears 330 and 430 corresponding thereto.

At least one coupling key groove 331 and 431 is formed in each of the internal gears 330 and 430, and the coupling key 221 corresponds to the coupling key groove 331 and 431. It is more preferable that it is formed in the number which becomes.

Hereinafter, the compressor of the present invention configured as described above will be described with reference to FIGS. 3 to 6.

First, referring to FIGS. 3 and 5, 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 the motor 2 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. The refrigerant flows into the casing 1 through a suction 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.

The refrigerant sent to the inner space of the outer 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.

On the other hand, the refrigerant undergoing a heat exchange process in the condenser 5 is re-introduced into the gear type expansion portion 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 may be used as the driving means as long as it generates a driving force other than the motor 2.

On the other hand, Figure 4a is a cross-sectional view taken 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 external gear 320 is formed to have more teeth grooves 320a than the number of teeth 330a of the inner gear 330 which is coupled to the motor shaft 220 and rotates, and the inner gear 330. The center of rotation and the center of rotation of the external 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 to illustrate 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.

6 is a graph comparing the torque change generated by the compressor of the present invention with the torque generated by the conventional compressor, wherein the vertical axis is a torque ratio obtained by dividing each torque value T by an average value Tm of torques 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.

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

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.

Meanwhile, referring to FIGS. 3 to 4B, the inner gear 330 constituting the compression part 3 and the inner gear 430 constituting the expansion part 4 are formed with the shaft 220 of the motor. Since they are coupled by a keying method, which is a joining machine element instead of a coupling method such as shrink-fit, press-fitting, etc., they are not only easily coupled to each other but also rotational force from the shaft 220 of the motor. This is accurately and intactly transmitted to each of the internal gears 330 and 430.

That is, each of the internal gears 330 and 430 stably supports the rotational torque transmitted by the motor and rotates by accurately receiving the rotational force of the motor, thereby further increasing the compression efficiency and expansion efficiency of the refrigerant.

 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 driving force and torque transmitted from the motor to the inner gear by improving the coupling force between the motor shaft and the internal gear.

Claims (11)

It comprises a motor, a gear-type compression unit for compressing the refrigerant introduced from the evaporator by receiving the driving force of the motor, and a gear-type expansion unit for expanding the refrigerant discharged from the compression unit and then re-absorbed through the condenser, 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 is fixed to the lower side of the motor; 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, And an inner gear of the gear type compression unit and an inner gear of the gear type expansion unit are coupled to the shaft of the motor in a fitting manner. The method of claim 1, A coupling key is provided on the shaft of the motor, and an inner gear of the gear-type compression unit and an inner gear of the gear-type expansion unit are respectively provided with coupling key grooves. Combination key of the gear type compressor, characterized in that each of the inner gear is rotated by receiving the rotational force of the motor through the shaft of the motor. The method of claim 2, The height of the coupling key is a gear-type compressor, characterized in that formed smaller than the thickness of the corresponding inner gear. The method of claim 2, At least one coupling key groove is provided in each of the inner gears, and the coupling key is provided in a number corresponding to the coupling key groove. The method of claim 1, The main bearing is a gear type compressor, characterized in that the sub-compression suction pipe (sub compression suction pipe) connected to the main bearing to send the refrigerant to the inner space of the outer gear. The method of claim 1, And a suction port is formed in the main bearing, and a discharge port is formed in the compression plate. The method of claim 1, The compression plate is a gear type compressor, characterized in that the compression discharge pipe (compression discharge pipe) for sending the compressed refrigerant to the condenser. The method of claim 1, And a expander suction pipe installed at one side of the sub-bearing to allow refrigerant passing through the condenser to flow into the expansion cylinder. The method of claim 1, The other side of the sub-bearing gear type compressor characterized in that an expander discharge pipe (expander discharge pipe) for sending the expanded refrigerant to the evaporator is installed. The method of claim 1, And a suction port and a discharge port are formed at predetermined positions in the sub bearing. The method of claim 1, The outer gear is a gear type compressor, characterized in that it is formed to have more teeth grooves than the number of teeth (teeth) of the inner gear is coupled to the motor shaft.

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