KR20000007205A - Structure to reduce inhale loss of impeller for turbo compressor - Google Patents

Abstract

PURPOSE: A structure is provided to remarkably reduce the loss of inhaling of the inhaled coolant gas and to easily manage the difference of the gap between an impeller and a shroud. CONSTITUTION: The structure comprises:an impeller(100,200) installed on a first and a second compressing chamber installed on both sides of a sealed container and on both ends of the drive shaft rotated by a motor, and installed to be symmetrical by a cone centering the drive shaft according to the inhaling direction of the coolant gas inhaled to each compressing chamber.

Description

Suction loss reduction structure of impeller for turbo compressor

The present invention relates to an impeller of a turbo compressor, and more particularly, to a suction loss reduction structure of an impeller for a turbo compressor which prevents the refrigerant sucked from flooding the vane of the impeller.

In general, a compressor is a machine that compresses gas such as air or refrigerant gas by a rotary motion of a vane or a rotor or a reciprocating motion of a piston, and is a power generator for driving a vane, a rotor, and a piston, and a driving force transmitted from the power generator. It consists of a compressor mechanism for sucking and compressing gas.

Such a compressor is classified into a hermetic type or a separable type according to the arrangement of the power generating portion and the compression mechanism. Among them, the hermetic compressor in which the power generating portion and the compression mechanism are installed together in one hermetically sealed container is recomposed according to the structure for compressing the gas. It is divided into rotary, reciprocating, linear and scroll compressor.

Among these, a turbo compressor recently introduced by the present invention rotates an impeller with a driving force of a motor, and sucks and compresses gas by using a centrifugal force generated when the impeller is rotated. FIG. 1 is a longitudinal sectional view showing an example of a conventional turbo compressor. .

As shown in the drawing, a conventional two-stage compression turbo compressor is normally sealed with a first compression chamber 11 communicating with an evaporator (not shown) and a second compression chamber 12 communicating with a condenser (not shown). It is formed on both sides of the container 10, the motor chamber 13 is formed in the inner center of the sealed container 10 is mounted with an axial type of brushless DC MOTOR (20), The first and second compression chambers 11 and 12 and the motor chamber 13 are communicated with each other by the first and second gas passages 14 and 15, and are coupled to the motor 20 to rotate. Both ends of the 30 are inserted into the first and second compression chambers 11 and 12, respectively, and at the ends thereof, the gas sucked while rotating in the first and second compression chambers 11 and 12, respectively, is compressed into two stages. The first and second impellers 40 and 50 for the combination are configured.

In addition, a radial bearing 60 for supporting the radial direction of the drive shaft 30 is coupled to both sides of the drive shaft 30, that is, both sides of the motor 20, and one side of the radial bearing 60. The outer thrust bearing 70 for supporting the axial direction of the drive shaft 30 is coupled.

In the figure, reference numeral 10a denotes an inlet port, 10b denotes a discharge port, 11a and 12a denote first and second diffusers, 11b and 12b denote first and second volutes, and 11c and 12c denote shrouds. The stator and 22 is the rotor.

The conventional two-stage compression turbocompressor configured as described above is operated as follows.

That is, when induction magnetism is generated in the motor 20 by the applied power source, the drive shaft 30 starts to rotate at a high speed by the induction magnetism and is fixed to both ends of the drive shaft 30. 2 The impellers 40 and 50 rotate, and the refrigerant gas is sequentially sucked into each of the compression chambers 11 and 12 by the rotation of the impellers 40 and 50, and then each of the impellers 40 and 50 It is sprinkled in the form of a screw by centrifugal force and flows through each diffuser 11a and 12a to each volute 11b and 12b, where it is pressurized while passing through the first diffuser 11a and the first volute 11b. In the process of flowing into the second diffuser 12a and the second volute 12b, the refrigerant gas was completely compressed by the rise of the pressure head and discharged to the condenser (not shown) through the discharge port 10b.

Here, each of the impellers 40 and 50 may be coupled in the form of an inverted cone around the drive shaft 30 according to the suction form of the refrigerant gas, or vice versa. It is the same that the impellers 40 and 50 are symmetrically coupled in all four branches.

Each of these impellers 40 and 50 includes inducers 42a and 52a on the outer circumferential surface of the hub flanges 41 and 51 through which drive shaft mounting inserts 41a and 51a are formed. A plurality of vanes 42 and 52 are twisted in the axial direction and are formed at equal intervals.

Since the hub flanges 41 and 51 are curved to have a constant curvature in consideration of the smooth flow of refrigerant gas, the vanes 42 and 52 also have a similar height from the suction side to the discharge side. Although formed, each vanes 42 and 52 are formed to be bent in the direction of rotation to the inducers (42a, 52a) in order to minimize the suction resistance of the refrigerant during rotation.

However, in the impeller of the conventional turbo compressor as described above, as the compressor is compact, the vanes 42 and 52 of the impellers 40 and 50 are formed very low, so that each wing as shown in FIG. A portion of the refrigerant gas sucked by the pressure difference between the inner (or compressed) and outer (or negative pressure) surfaces of the cars 42 and 52 flows from the inner side of the high pressure to the outer side of the low pressure. There was a risk of generating suction loss of the refrigerant gas.

In addition, in order to prevent the loss of the refrigerant gas, the gap between the impellers 40 and 50 and the shrouds 11c and 12c formed to surround the outer surface of the impeller should be kept to a minimum. There was also a problem that tolerance management is difficult because it is coupled to the drive shaft 30 that rotates while starting up.

Accordingly, the present invention is conceived in view of the problems of the impeller of the conventional turbo compressor as described above, and easy to manage the tolerance for the gap between the impeller and the shroud, while the turbo which can significantly reduce the suction loss of the refrigerant gas sucked in It is an object of the present invention to provide a structure for reducing the suction loss of an impeller for a compressor.

1 is a longitudinal sectional view showing an example of a conventional turbo compressor.

Figure 2a is a perspective view of the impeller of a conventional turbo compressor.

FIG. 2B is a front view of part “A” of FIG. 2A;

Figure 3a is a perspective view showing an example of the impeller of the turbocompressor of the present invention.

FIG. 3B is a front view of part “B” of FIG. 3A;

Figure 4a is a perspective view showing a modification of the impeller of the present invention turbo compressor.

4B is a front view of part “C” of FIG. 4A;

Explanation of symbols on the main parts of the drawings

100,200: impeller 110,210: hub flange

111,211: Insertion hole for driving shaft 120,220: Wing car

121,221: Inducer 130,230: Flow preventing rod

140,240: Flow prevention jaw

In order to achieve the object of the present invention, the air fence for preventing the overflow of the fluid on the outer rim of each vane that is formed to protrude on the outer peripheral surface of the hub flange mounted to the drive shaft to suck and discharge the fluid during rotation (air A suction loss reduction structure of an impeller for a turbocompressor, characterized by forming a fence, is provided.

Hereinafter, the suction loss reduction structure of the impeller for a turbo compressor according to the present invention will be described in detail based on the embodiment shown in the accompanying drawings.

Figure 3a is a perspective view showing an example of the impeller of the turbocompressor of the present invention, Figure 3b is a front view of the "B" portion of Figure 3a.

As shown therein, the impeller of the present invention is mounted on both ends of the drive shaft (not shown) rotated by the motor (not shown), respectively, the first and second compression chambers formed on both sides of the sealed container (not shown) ( The impellers 100 and 200 are symmetrically mounted in a conical or inverted cone shape around a driving shaft (not shown) according to the suction direction of the refrigerant gas sucked into each compression chamber.

The impellers 100 and 200 are integrally formed with an inducer for inducing fluid intake, and a plurality of inducers 121 and 221 are included on the outer circumferential surfaces of the hub flanges 110 and 210 through which drive shaft mounting inserts 111 and 211 are formed. The vanes 120 and 220 are twisted in the axial direction and are formed at equal intervals.

Since the hub flanges 110 and 210 are formed to be curved with a constant curvature in consideration of the smooth flow of refrigerant gas, the vanes 120 and 220 are also formed to be curved with the same height from the suction side to the discharge side, respectively. The vanes 120 and 220 are formed to be bent in the rotational direction toward the inducers 121 and 221 to minimize the suction resistance of the refrigerant during rotation.

Here, each of the vanes before the discharged fluid is discharged in the normal direction, that is, the respective diffusers (not shown) and the volute (not shown) along the vanes 120,220 on the outer edges of the vanes 120 and 220. Air fences are formed outside the vanes 120 and 220 in order to prevent flooding beyond the vans 120 and 220, which are shown in FIGS. 3A and 3B. Flow prevention rods 130 and 230 having a diameter larger than the thickness of the vanes are mounted on the outer rim of the vanes or as shown in FIGS. 4A and 4B, the outer sides of the vanes 120 and 220 are curved toward the inner side. It is bent to form a flow barrier (140, 240).

The general operation of the turbo compressor equipped with the impeller of the present invention as described above is the same as in the prior art.

That is, referring to FIG. 1, the refrigerant gas sucked into the first impeller 100 through the first gas passage 14 of the hermetically sealed container (not shown) is first diffused by the first impeller 100. 11a) and one-stage compressed by the centrifugal force while being discharged to the first volute (11b), the pressurized shaft gas compressed in the first stage is sucked into the second impeller 200 through the second gas flow path 15 and again the second As it is discharged to the diffuser 12a and the second volute 12b, it is also compressed by two stages by centrifugal force and then discharged to a condenser of a refrigeration cycle apparatus.

At this time, the refrigerant gas sucked into each impeller (100,200) is attracted to the inner surface (or compressed surface) of each vane (120,220) is attracted to each diffuser (11a, 12a) and volute (11b, 12b) The inner surfaces (or compression surfaces) of the vanes 120 and 220 are discharged, and the high pressure portions are formed, while the outer surfaces (or negative pressure surfaces) of the vanes 120 and 220 are formed with low pressure portions, respectively. Some of the refrigerant gas sucked into the inner surface of the vanes overflows from the high pressure portion to the low pressure portion, that is, from the inner surface of the vanes 120 and 220, which is generally about 2 mm, but the vanes 120 and 220 Since the flow preventing rods 130 and 230 of the present invention are attached to the outer edge of the) or the flow preventing jaws 140 and 240 are formed to be bent inwardly, the refrigerant gas to be flooded outward from the inside of the vanes 120 and 220 flows as described above. Prevention rods 130, 230 or flow prevention jaws (140, 240) Coming back to the original hanging on the inner side will be discharged to the top of each diffuser (11a, 12a) and a volute (11b, 12b).

Thus, even if the height of each vanes 120 and 220 is not formed too high, the suction loss of the refrigerant gas in each vanes 120 and 220 may be reduced to a minimum, and the height of the vanes 120 and 220 may be increased. Since it is not necessary, the clearance gap between the shrouds 11c and 12c facing the outer surfaces of the vanes 120 and 220 can be increased, thereby allowing easy tolerance management.

As described above, the suction loss reduction structure of the impeller for a turbocompressor according to the present invention is formed on the outer circumferential surface of the hub flange mounted on the drive shaft, and the fluid is formed on the outer rim of each vane that sucks and discharges the fluid during rotation. By forming an air fence to prevent flooding, the refrigerant gas sucked into each impeller does not overflow each vane, thereby significantly reducing the suction loss of the refrigerant and making the vane too high. Since it is not necessary to form, it is easy to manage the tolerance of the gap between the impeller and the shroud, thereby improving productivity.

Claims (3)

Turbo compression, characterized in that formed on the outer peripheral surface of the hub flange mounted on the drive shaft protruding to form an air fence to prevent the fluid overflow on the outer rim of each vane that sucks and discharges the fluid during rotation Suction loss reduction structure of aircraft impeller. The method of claim 1, wherein the air fence is a suction loss reduction structure of the impeller for turbo compressor, characterized in that formed on the outer rim surface of each vane by mounting a flow preventing rod larger than the thickness of the vane. The structure of claim 1, wherein the air fence is formed by bending a flow stopper toward an inner side of each vane.