KR100202622B1 - Variable velocity scroll compressor - Google Patents

Abstract

The variable speed scroll compressor according to the present invention includes a drive shaft, a drive pin eccentrically protruded from an upper end of the drive shaft, a drive bush for sliding movement while being in contact with the planar portion of the drive pin, and a swing scroll coupled to the drive bush. In the variable speed scroll compressor in which the operating frequency is changed while being driven, the variable radius clearance determined by the eccentricity of the driving pin, the turning radius of the turning scroll, the outer diameter of the driving pin, and the inner diameter of the driving bush is equal to the fixed radius gap. By taking advantage of the fixed radius type in the low speed area, the leakage efficiency is minimized to increase the efficiency of the compressor.In the case of rated and high speed operation, the variable radius type is adopted to minimize the leakage than the fixed radius type. Reliability is increased compared to the variable radius that gives the inclination angle.

Description

Variable speed scroll compressor

The present invention relates to the lateral leakage prevention of a variable speed scroll compressor, in particular in the low speed region to take advantage of the fixed radius type to minimize the leakage to increase the efficiency of the compressor, taking advantage of the variable radius type at the rated and high speed operation The present invention relates to a variable speed scroll compressor that minimizes leakage rather than a radial type and improves reliability compared to a variable radius type having an inclination angle on a cross section of a driving pin.

As shown in FIG. 1, a typical scroll compressor includes a fixed scroll 1 located above the inside of the compressor main body, a swing scroll 2 coupled to a lower portion of the fixed scroll, and a main frame located below the swing scroll. (8) and a drive shaft (4) for rotating the pivoting scroll through the central portion of the main frame are connected to the rotor (5) and the stator (6).

Below the swing scroll 2, an all-dam ring 3, which is a rotation prevention mechanism for preventing the rotation of the swing scroll, is installed, and the upper end of the drive shaft 4 is eccentric to swing the swing scroll.

By the apparatus configured as described above, the refrigerant gas sucked through the suction pipe 9 is simultaneously sucked at both ends of the scroll in accordance with the swinging motion of the swinging scroll 2, and thus, between the swinging scroll 2 and the fixed scroll 1 It is trapped in two symmetrical crescent-shaped pockets formed in the pocket, which continuously move toward the center with a volume decrease, thereby compressing the refrigerant gas. When the pockets come to the center, the two pockets merge with each other, and the ejection opening is opened and the ejection starts.

Regarding the refrigerant leakage of the scroll compressor operated as described above, in the leakage inside the compression chamber, as shown in FIGS. 2 and 4, the involute between the tip of the scroll (1) wrap and the bottom of the opposite scroll (2) member is shown. Radial gaps 12 at the lap side portions of the scrolls 1 and 2 which abut against the leakage r generated radially by the axial gaps 13 along the curve of the shape, as shown in FIGS. 2 and 3. ), There is a leakage n that occurs in the tangential direction. The radial sealing structure for preventing leakage n occurring in the tangential direction between the latter wrap side portions includes a variable radius type and a fixed radius type.

Referring to FIG. 5, in the case of the variable radius type, the eccentric drive pin 4a having the same center as the swing scroll 2 and driving the swing scroll protrudes at one end of the drive shaft 4. By turning the slide along the planar portion, the turning radius, which is the distance between the center of the driving shaft 4 and the center of the driving bush 7, that is, the center of the turning scroll 2, can be varied. When the lap is in contact with the fixed scroll lap, the centrifugal force of the swivel scroll acts between the laps to perform sealing, and during hydraulic compression or foreign matter intervention, the swivel scroll retreats in the direction of increasing the gap between the laps so that excessive load is not applied between the laps. In this variable radius formula, the sealing force acting between the laps is a value obtained by subtracting the radial gas force from the centrifugal force of the turning scroll and the drive bushing. The centrifugal force of the swing scroll and the drive bush is changed according to the rotational speed of the compressor, and the radial gas force is affected by the operating conditions of the compressor.

In the figure, reference numeral 11 denotes a compression chamber.

In variable speed scroll compressors, there are many operations in the low speed region lower than the rated operating frequency. In the conventional variable radius type, the centrifugal force becomes very small in comparison with the radial gas force at low speed, so it is impossible to add proper sealing force. There is a lot of leakage in the chamber, which reduces the efficiency of the compressor. In order to solve this problem, a method of adding a tangential gas force to the sealing force by giving an inclination angle to the drive pin of the drive shaft has been devised. The problem with this method is that it can add an appropriate sealing force in the low speed range. However, when the high speed range is higher than the rated operating frequency, excessive sealing force is exerted compared to the conventional variable radius. There is a problem with noise and reliability.

On the other hand, in the latter fixed radius type, since the driving pin of the drive shaft is eccentric as much as the turning radius to drive the turning scroll, there is no change in the sealing force at the low speed, the high speed, and the entire area of the variable speed scroll compressor. However, since the eccentricity of the drive pins cannot be exactly matched to the turning radius, the drive pins are located within a range of ± 30 μm. If the eccentricity of the driving pin is larger than the turning radius, the friction loss increases due to the friction between the laps, and the wear and noise between the laps becomes a problem.In the actual design, the driving pin eccentricity is designed to be somewhat smaller than the turning radius. Since there is always a certain gap in all areas of the city, there must be a certain amount of leakage in all areas of low speed and high speed.

In the variable speed scroll compressor according to the related art, in the case of the variable radial type of the radial sealing structure, the centrifugal force becomes small during the low speed region operation of the variable speed scroll compressor, and the sealing force decreases, thereby increasing leakage and reducing the efficiency of the compressor. When the inclination angle is given to the end face of the driving pin, excessive sealing force is generated in the high speed region, thereby causing friction and wear between the fixed scroll wrap and the turning scroll wrap.

In the case of the fixed radius type, it has an advantage over the leakage in the low speed range of the variable radius type, but because it has a constant clearance at the rated and high speed operation, there is a problem that the leakage is larger than the variable radius type, an object of the present invention In consideration of the above problems, in the low speed region, the advantage of fixed radius type is minimized to increase the efficiency of the compressor by minimizing leakage. It is to provide a variable speed scroll compressor to minimize and to increase the reliability compared to the variable radius of the inclined angle of the drive pin.

1 is a cross-sectional view showing a typical scroll compressor.

Figure 2 is a structural diagram showing the leakage of refrigerant in accordance with the wrap structure of a typical scroll compressor.

3 is a schematic configuration diagram showing a lateral leakage of a general scroll compressor.

4 is a schematic block diagram showing radial leakage of a general scroll compressor.

5 is a cross-sectional view showing a driving pin and a slide bush of a general scroll compressor.

6 is a block diagram showing a variable radius clearance of the scroll compressor according to the present invention.

7 is a diagram showing the leakage loss according to the variable radius clearance of the scroll compressor according to the present invention.

Explanation of symbols for main parts of the drawings

2 ; Turning scroll 31; driving axle

32; Drive pin 33; Drive Bush

A; Inner diameter B of the driving bush; Outer diameter of drive pin

C; Turning radius D of turning scroll D; Eccentricity of Drive Pin

E; Variable Radius Clearance

The object of the present invention is a drive shaft, a drive pin eccentrically protruded at an upper end of the drive shaft, a drive bush for sliding movement in contact with the planar portion of the drive pin, and the swing scroll is coupled to the drive bush In a variable speed scroll compressor in which a driving frequency is changed while being driven, the variable radius clearance defined by the eccentricity of the drive pin, the turning radius of the turning scroll, the outer diameter of the driving pin, and the inner diameter of the driving bush has the same value as the fixed radius gap. Is achieved.

Hereinafter, a variable speed scroll compressor according to the present invention will be described according to the embodiment shown in the accompanying drawings.

FIG. 5 is a cross-sectional view illustrating a driving pin and a slide bush of a general scroll compressor, and FIG. 6 is a block diagram illustrating a variable radius gap of the scroll compressor according to the present invention, and FIG. 7 is a variable radius of the scroll compressor according to the present invention. The diagrams show the leakage loss along the gap.

As shown in the drawing, the variable speed scroll compressor according to the present invention slides while being in contact with a drive shaft 31, a drive pin 32 formed to be eccentrically protruded from an upper end of the drive shaft, and a flat portion 32a of the drive pin. In the drive bushing 33 and the variable speed scroll compressor in which the driving frequency is changed while the swinging scroll is coupled to the driving bushing, the eccentric amount (D) of the driving pin, the turning radius (C) of the turning scroll, and the driving The variable radius clearance E determined by the outer diameter B of the pin and the inner diameter A of the drive bushing has the same value as the fixed radius clearance.

The variable radius clearance is determined as follows. E = (A-B) / 2 + (C-D) [E; Variable radius clearance, A; Drive bushing bore, B; Drive pin outside diameter, C; Turning radius, D; Drive pin eccentricity]

The loss by the leakage in the low speed area | region by this variable radius clearance is shown in FIG. In the present invention, the variable radius clearance E is maintained at a fixed radius clearance so that the loss due to leakage generated during the low speed region operation is equivalent to the fixed radius clearance. In addition, the drive bush cannot be moved beyond the turning radius due to the contact between the laps during the rated and high speed operation. Therefore, the advantages of the existing variable radius type are kept as it is, and the leakage is minimized compared to the fixed radius type. At the same time, there is an advantage in friction loss and wear between wraps due to excessive sealing force. Therefore, in all the frequency domain of the variable speed scroll compressor operation to compensate for the disadvantages in the existing radial sealing structure contributes to the high efficiency and reliability of the variable speed scroll compressor.

In the above structure, the drive bush is mounted on the protruding drive pin of the drive shaft, and the revolving scroll boss portion 2a is coupled thereto, but in another embodiment, the revolving pin has a protruding pin portion under the hard plate of the revolving scroll. Forming a boss portion, by combining the boss portion and the drive bushing capable of sliding movement, the same effect can be obtained even if the variable radius clearance is maintained.

As described above, the variable speed scroll compressor according to the present invention includes a drive shaft, a drive pin eccentrically protruded from an upper end of the drive shaft, a drive bush that slides in contact with the planar portion of the drive pin, and the drive thereof. In a variable speed scroll compressor in which a driving scroll is coupled with a swinging scroll to be driven, the variable radius clearance determined by the eccentricity of the driving pin, the turning radius of the turning scroll, the outer diameter of the driving pin, and the inner diameter of the driving bush is fixed. By having the same value as the radial clearance, it takes advantage of the fixed radius type in the low speed area to minimize the leakage to increase the efficiency of the compressor, and at the rated and high speed operation takes advantage of the variable radius type to minimize the leakage than the fixed radius type In addition, there is an effect to increase the reliability compared to the variable radius giving the inclination angle on the cross section of the drive pin.

Claims (1)

A drive shaft, a drive pin which is formed to be eccentrically protruded at an upper end of the drive shaft, a drive bush for sliding movement while being in contact with the planar portion of the drive pin, and a variable speed in which the driving frequency changes while the swing scroll is driven in combination with the drive bush. In the scroll compressor, the variable radius clearance (E) {E = (AB) / 2 + (CD) [A; driving bushing diameter, B; driving pin outer diameter, C; turning scroll radius, D; driving pin eccentricity ]} Variable speed scroll compressor, characterized in that to have the same value as the fixed radius clearance.

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