KR20010028034A - Apparatus for preventing backflow of active gas in scroll compressor - Google Patents

Abstract

PURPOSE: A backflow prevention apparatus for scroll compressor is provided to reduce noise of the compressor by preventing a collision between the fixed scroll and the check valve. CONSTITUTION: A backflow prevention apparatus comprises a fixed scroll(51) engaged with a swirling scroll so as to form a plurality of compression pockets(P) and which has an outlet port(51a) for discharging the refrigerant gas compressed in the compression pocket; a cylindrical check valve housing(55) fixed onto the fixed scroll so as to accommodate the outlet port and which has a pressure hole(55a) and a discharge hole(55b) formed at the top surface and the side surface of the check valve housing, respectively; and a cylindrical check valve(53) arranged within the check valve housing in such a manner that the check valve moves in vertical direction in accordance with the discharge pressure of the refrigerant gas so as to open/shut the outlet port of the fixed scroll. The check valve housing is provided with a free space to allow the check valve to move in vertical direction from the discharge hole of the check valve housing, to thereby prevent a contact between the fixed scroll and the check valve caused by the downward movement of the check valve.

Description

Backflow prevention device of scroll compressor {APPARATUS FOR PREVENTING BACKFLOW OF ACTIVE GAS IN SCROLL COMPRESSOR}

The present invention relates to a backflow prevention device of a scroll compressor, and more particularly, a backflow of a scroll compressor having a sufficient flow space for moving the check valve downward in the check valve housing to prevent contact noise between the fixed scroll and the check valve. It relates to a prevention device.

The scroll compressor according to the prior art, as shown in Figures 1 to 3, the upper and lower frames (2, 3) are coupled to the upper and lower sides of the sealed container (1) having a predetermined internal volume, respectively, A stator 4 and a rotor 5 forming a motor are installed between the upper frame 2 and the lower frame 3.

In addition, a rotating shaft 6 having an eccentric portion 6a which rotates together with the rotation of the rotor 5 at the center of the rotor 5 is coupled, and a fixed scroll 7 to the upper frame 2. ) Is fixed.

In addition, the involute wrap 7a formed on the fixed scroll 7 and the wrap 8a of the swing scroll 8 engaged therewith are pivotally engaged with each other, and the lower portion of the swing scroll 8 is rotated. It is coupled to the eccentric portion (6a) of the rotary shaft (6), the old dam ring (9) for preventing the rotation of the swing scroll (8) is coupled to the lower portion of the swing scroll (8).

In addition, a discharge port 7b for discharging the high-temperature, high-pressure refrigerant gas compressed in the compression pocket, which is a compression space, to the outside of the compression pocket is formed at the center of the fixed scroll 7, and the upper surface of the fixed scroll 7 The check valve 10 and the check valve housing 11 which open and close the discharge port 7b are provided.

In addition, a high low pressure separating plate 13 for separating the inside of the sealed container 1 into a high pressure part and a low pressure part is installed on the upper side of the fixed scroll 7, and the high low pressure separating plate 13 includes a plurality of bolts 14. Is coupled to the fixed scroll (7) and welded to the hermetic container (1).

Here, the check valve housing 11, as shown in Figure 2, the pressure hole (11a ') on the upper surface so that the pressure of the high pressure portion separated by the high and low pressure separating plate 13 to the check valve 10 can be applied to And a body portion 11a having a discharge hole (not shown) formed at a side thereof so that the refrigerant gas passing through the check valve 10 can be discharged to the high pressure portion, and formed at a lower end of the body portion 11a. And a fastening portion 11b fixed to the fixed scroll 7 by the fastening bolt 12.

In addition, the check valve 10 is formed in a cylindrical shape is installed inside the check valve housing 11 to move up and down along the inner surface of the body portion (11a) of the check valve housing (11).

In addition, a suction tube 15 and a discharge tube 16 through which refrigerant gas is sucked are formed at the side of the sealed container 1, and an oil supplied for lubrication of the sliding part at the lower part of the sealed container 1. Is filled.

Operation of the scroll compressor including each component as described above, first, when the rotor 5 is rotated by the applied current, the rotary shaft 6 is rotated by the rotation of the rotor (5) By turning the eccentric distance of the core portion 6a into a radius, the orbiting scroll 8 is subjected to a circular motion, that is, an orbital motion.

At this time, the turning scroll 8 is rotated by drawing the turning member at a distance as far as the turning radius while the rotation center is prevented by the Oldham ring (9).

By the swinging motion of the swinging scroll 8 as described above, a compression pocket P, which is a compression space, is formed between the fixed scroll 7 and the wraps 7a, 8a of the swinging scroll 8, and this compression pocket P ) Is moved to the center by the continuous turning motion of the turning scroll 8 to reduce the volume to compress the refrigerant gas is sucked.

Through this process, when the refrigerant gas is compressed and becomes equal to or greater than a predetermined pressure, the check valve 10 blocking the discharge port 7b of the fixed scroll 7 is raised by the pressure of the refrigerant gas to discharge the discharge port. 7b is opened. Thereafter, the refrigerant gas is discharged to the outside of the compression pocket (P) through the discharge port (7b).

As described above, the refrigerant gas discharged through the discharge port 7b is moved to the high pressure portion separated by the high and low pressure separator 13, and then discharged to the outside of the compressor through the discharge tube 16, the check valve 10 Is lowered again by the pressure acting on the upper surface of the check valve 10 through the pressure hole 11a 'of the check valve housing 11 to block the discharge port 7b to discharge the refrigerant gas to the discharge port 7b. The reverse flow of the refrigerant gas flowing into the compression pocket (P) again through).

However, when the check valve 10 operated as described above is used in an operating condition in which the compression ratio is increased due to a drop in suction pressure or the like, it causes a problem of noise.

More specifically, the suction pressure of the refrigerant gas is Ps, the volume and temperature immediately after the suction of the refrigerant gas are Vs and Ts, the discharge pressure of the refrigerant gas is Pd, and the volume and temperature immediately before the discharge of the refrigerant gas are Vd and In the case of Td, nR = (Ps x Vs) / Ts = (Pd x Vd) / Td by PV = nRT, so that Pd can be expressed by Equation 1 below.

In addition, the sum of the forces acting on the check valve 10 may be represented by Equation 2 below.

Here, Pf is a value obtained by subtracting the pressure Pa leaked between the upper surface of the fixed scroll 7 and the check valve 10 from the discharge pressure Pd of the refrigerant gas, wherein A represents the cross-sectional area of the check valve 10, M denotes the mass of the check valve 10.

Therefore, Equation 2 may be expressed as Equation 3 below.

Assuming that there is no pressure leaking between the upper surface of the fixed scroll 7 and the check valve 10 in Equation 3 as described above, Pa = 0 and using Equation 1 above, Equation 3 is It can be expressed as Equation 4.

Ps = 5.34 kg / cm 2 G, Vs = 34 cm 3, Ts = 75 ° C., Vd = 14.2 cm 3, Td = 115 ° C., and Po = 20 kg / cm 2 G in the above equation (4), Σ F =-(0.4A + mg) and the check valve 10 is lowered.

Therefore, when the Ps decreases due to a decrease in suction pressure during the compression process of the compressor, that is, when the compression ratio is increased, the driving force of the check valve 10 is increased since ΣF < The movement distance to the lower side of (10) becomes longer.

However, in the conventional check valve 10 and the check valve housing 11 structure, since there is no free space in which the check valve 10 can be moved downward, the compression ratio is increased due to a drop in suction pressure and the like. The lower the moving distance of the) is the check valve 10 is lowered while hitting the upper surface of the fixed scroll (7) is a problem that the contact sound due to the collision of the fixed scroll (7) and the check valve (10) occurs There was this.

In particular, the contact noise between the check valve 10 and the fixed scroll (7) as described above while the check valve 10 is repeatedly raised and lowered according to the magnitude of the pressure Pf acting on the lower surface of the check valve (10). As it is repeated over and over, it becomes a serious noise problem.

In addition, the structure of the conventional check valve 10 and the check valve housing 11 is fixed to the bottom surface of the check valve 10 because the check valve 10 hits the upper surface of the fixed scroll 7 as described above. There is a problem that the upper surface of the scroll 7 is worn or broken due to the collision and the mechanical durability is weak.

In the above, reference numeral S, which is not described, indicates a moving distance in which the check valve 10 is raised when Po + mg <Pf.

An object of the present invention devised in view of the above problems, the check valve housing is provided with a sufficient flow space to move the check valve to the lower side to prevent the contact between the check valve and the fixed scroll fixed scroll The present invention provides a device for preventing the backflow of a scroll compressor, in which contact noise between the check valve and the check valve is removed to reduce the noise of the compressor.

1 is a longitudinal sectional view showing a scroll compressor according to the prior art,

FIG. 2 is a cross-sectional view showing part A of FIG. 1 in detail;

3 is a cross-sectional view showing a backflow preventing device of a scroll compressor according to the present invention;

4 is a (a) front view and (b) bottom view showing the structure of a check valve according to the present invention,

5 is (a) a front view and (b) a bottom view showing the structure of a check valve housing according to the present invention;

6 is a (a) front view and (b) bottom view showing the structure of a check valve according to another embodiment of the present invention,

7 is a cross-sectional view showing a state in which a check valve is assembled to a check valve housing according to another embodiment of the present invention;

8 is a (a) front view and (b) bottom view showing the structure of a check valve housing according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

51: fixed scroll 51a: discharge port

53: check valve 55: check valve housing

55a: pressure hole 55b: discharge hole

In order to achieve the object of the present invention as described above, the fixed scroll and the discharge port to form a plurality of compression pockets in engagement with the rotating scroll and discharge the refrigerant gas compressed in the compression pocket in the center, and the discharge port A cylindrical check valve housing fixed to an upper side of the fixed scroll and having pressure and discharge holes formed on upper and side surfaces thereof, and installed to move up and down in accordance with the discharge pressure of refrigerant gas in the check valve housing. Consists of a check valve for opening and closing, the check valve housing has a free flow space for the check valve can be moved more than a predetermined distance in each of the upper and lower directions, based on the discharge hole due to the lower movement of the check valve Scroll pressure, characterized in that to prevent contact between the fixed scroll and the check valve The non-return device of the machine is provided.

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

Figure 3 is a cross-sectional view showing a backflow prevention device of the scroll compressor according to the present invention, Figure 4 is a (a) front view and (b) bottom view showing the structure of a check valve according to the invention, Figure 5 (A) a front view and (b) a bottom view showing the structure of a check valve housing according to the invention, Figure 6 is a (a) front view and (b) showing a structure of a check valve according to another embodiment of the present invention 7 is a cross-sectional view showing a state in which a check valve is assembled to a check valve housing according to another embodiment of the present invention, and FIG. 8 is a structure of a check valve housing according to another embodiment of the present invention. (A) front view and (b) bottom view.

3 to 5, the reverse flow prevention apparatus of the scroll compressor according to the present invention forms a plurality of compression pockets P in engagement with the turning scroll and simultaneously cools the refrigerant gas compressed in the compression pocket P at the center thereof. A fixed scroll 51 having a discharge port 51a for discharging is formed, and fixed to an upper side of the fixed scroll 51 to accommodate the discharge port 51a, and a pressure hole 55a and a discharge hole on the upper and side surfaces thereof, respectively. A cylindrical check valve 55 formed with a cylindrical check valve housing 55b and a cylindrical check valve installed in the check valve housing 55 to move up and down in accordance with the discharge pressure of the refrigerant gas to open and close the discharge port 51a. 53, the check valve housing 55 is the check valve 53 is the discharge hole so that the contact between the fixed scroll 51 and the check valve 53 due to the lower movement of the check valve 53 is prevented Up and down both directions based on (55b) Over each predetermined distance and has a free flow space which can be moved.

Here, a high and low pressure separation plate for separating the sealed container into a high pressure portion and a low pressure portion is installed on the upper side of the fixed scroll 51, the pressure hole (55a) of the check valve housing 55 is separated by the high and low pressure separation plate The pressure Po of the high pressure portion serves to act on the upper surface of the check valve 53.

In addition, the discharge hole 55b of the check valve housing 55 serves to discharge the refrigerant gas discharged from the compression pocket P through the discharge port 51a to the outside of the check valve housing 55. A plurality of check valve housings 55 are formed at regular intervals.

In addition, the discharge port 51a is formed with an extended portion 51a 'having an enlarged diameter at an upper portion thereof, and the check valve housing 55 is press-installed with a lower portion in an expanded portion 51a' of the discharge port 51a. It is.

6 and 7, the refrigerant gas discharged through the discharge port 51a is discharged to the lower portion of the check valve 153 through the discharge hole 55b of the check valve housing 55. A plurality of discharge grooves 153a may be formed in the vertical direction to be discharged smoothly.

In addition, according to another embodiment illustrated in FIG. 8, the check valve housing 155 has pressure holes 156a and discharge holes 156b formed on upper and side surfaces thereof, respectively, and is checked based on the discharge holes 156b. Cylindrical body portion 156 having a free flow space so that the valve 53 can be moved over a predetermined distance in each of the upper and lower directions, and formed at a predetermined height of the body portion 156 and the fastening bolt is penetrated A fastening hole 157a may be formed and may include a fastening part 157 fixed to the fixed scroll 51 by the fastening bolt.

The check valve housing 55 as described above may be formed by overlapping two cylindrical members having fastening pieces formed at the bottom thereof in a direction facing each other with a predetermined interval therebetween, wherein the gap between the cylindrical members is formed in the discharge hole. (156b).

In addition, the lower portion of the body portion 156 is inserted into an expansion portion 51a 'formed at an upper portion of the discharge port 51a.

The reverse flow prevention apparatus of the scroll compressor according to the present invention configured as described above operates as follows.

First, the refrigerant gas is sucked into the compression pocket P formed by the fixed scroll 51 and the revolving scroll 51 and then compressed and discharged through the discharge port 51a of the fixed scroll 51. Acts on the lower surface of the check valve 53. At this time, the pressure actually acting on the lower surface of the check valve 53 is Pf minus the pressure Pa leaking through the discharge hole 55b formed in the check valve housing 55 from the above Pd.

In the above state, the force Pf × A acting on the lower surface of the check valve 53 to push the check valve 53 upward is the upper surface of the check valve 53 to push the check valve 53 downward. If the force Po x A acting on and the load mg of the check valve 53 are equal to the sum, that is, if Pf = Po + mg / A, the check valve 53 does not move up or down from a certain position. Will be maintained. At this time, m denotes the mass of the check valve 53, and A denotes the cross-sectional area of the check valve 53.

Thereafter, when the discharge pressure Pd of the refrigerant gas is increased to Pf> Po + mg / A, the check valve 53 is raised to open the discharge port 51a. At this time, the rising distance of the check valve 53 is S1.

When the check valve 53 is raised as described above and the discharge port 51a is opened, the refrigerant gas in the compression pocket P is discharged through the discharge port 51a to discharge the discharge hole 55b of the check valve housing 55. It is moved to the high pressure part through).

As described above, the force acting on the check valve 53 while the refrigerant gas is discharged momentarily becomes Pf = Po + mg / A so that the check valve 53 is stopped at a predetermined position.

Thereafter, when the discharge of the refrigerant gas is completed and Pf &lt; Po + mg / A, the check valve 53 is lowered again to block the discharge port 51a. At this time, the falling distance of the check valve 53 is S2. The above process continues at a rapid rate.

In the compression process of the compressor, when the compression ratio is increased due to a decrease in suction pressure, etc., the driving force increases to ΣF &lt; 0 so that the force pushing the check valve 53 downward increases. The travel distance to the lower side is longer than in normal driving condition.

In this case, in the present invention, the compression ratio is increased due to a decrease in suction pressure, so that the check valve 53 is stopped before the fixed scroll 51 is hit even if the downward travel distance of the check valve 53 is increased. Since the check valve 53 has a sufficient flow space in which the check valve 53 can be moved up and down in both directions, the check valve housing 55 prevents the collision between the fixed scroll 51 and the check valve 53. Will be.

In the above description, reference numerals L1 and L2, which are not described, indicate the height and depth of the free flow space provided in the check valve housing 55 so that the check valve 53 can be moved in both up and down directions.

As described above, the apparatus for preventing the backflow of the scroll compressor according to the present invention includes the check valve 53 in the check valve housing 55 such that the check valve 53 can be moved upwards or downwards by a predetermined distance. Since a sufficient flow space is provided, even if the compression ratio is increased due to a drop in suction pressure, the check valve 53 is stopped before hitting the fixed scroll 51 even if the downward travel distance of the check valve 53 is increased. The collision between the fixed scroll 51 and the check valve 53 is prevented, and thus the contact noise between the fixed scroll 51 and the check valve 53 is removed, thereby reducing the noise of the compressor.

In addition, since the present invention prevents a collision between the fixed scroll 51 and the check valve 53 as described above, wear or damage of the upper surface of the fixed scroll 51 and the lower surface of the check valve 53 due to the collision are prevented. As a result, the mechanical durability is enhanced and the compressor performance and lifespan are improved.

Claims (4)

A fixed scroll having a discharge port for discharging the refrigerant gas compressed from the compression pocket at the center thereof to form a plurality of compression pockets in engagement with the turning scroll, and fixed to an upper side of the fixed scroll to accommodate the discharge port; A check valve housing having a pressure hole and a discharge hole formed therein, and a check valve installed inside the check valve housing to move up and down according to the discharge pressure of the refrigerant gas, and opening and closing the discharge port. The check valve housing has a free flow space so that the check valve can be moved upwards or downwards in both directions, based on the discharge hole, to provide contact between the fixed scroll and the check valve due to the downward movement of the check valve. Backflow prevention device of the scroll compressor, characterized in that the prevention. The method of claim 1, The discharge port has an extended portion having an enlarged diameter formed on the upper portion, the check valve housing is a reverse flow prevention device of the scroll compressor, characterized in that the lower portion is press-installed in the expansion portion of the discharge port. The method of claim 1, The check valve and the check valve housing is a reverse flow prevention device of the scroll compressor, characterized in that each formed in a cylindrical shape. The method of claim 3, wherein The check valve is a reverse flow prevention device of the scroll compressor, characterized in that a plurality of discharge grooves formed in the upper and lower directions so that the refrigerant gas discharged through the discharge port can be smoothly discharged through the discharge hole of the check valve housing.