JP2007092722A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an asymmetrical scroll compressor having good operating efficiency. <P>SOLUTION: The scroll compressor has an outer compression chamber bypass port with a check valve, which is formed in an end plate of a fixed scroll and brings a tip portion of an outer compression chamber Y into communication with a discharge chamber when an orbiting scroll turns from an angular position of confining the outer compression chamber Y over a bypass turning angle θ<SB>out</SB>and a confined volume V<SB>out</SB>(0) of the outer compression chamber Y is decreased to a predetermined bypass volume V<SB>out</SB>(a), and an inner compression chamber bypass port with a check valve, which is formed in the end plate of the fixed scroll and brings a tip portion of an inner compression chamber X into communication with the discharge chamber when the orbiting scroll turns from an angular position of confining the inner compression chamber X over a bypass turning angle θ<SB>in</SB>and a confined volume V<SB>in</SB>(0) of the inner compression chamber X is decreased to a predetermined bypass volume V<SB>in</SB>(a). The bypass turning angles θ<SB>out</SB>and θ<SB>in</SB>are set so that V<SB>in</SB>(a)/V<SB>in</SB>(0)>V<SB>out</SB>(a)/V<SB>out</SB>(0) is satisfied. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scroll compressor used as a gas (refrigerant) compressor such as a refrigerator, a freezer, and an air conditioner.

As a conventional scroll compressor, in a scroll compressor provided with a fixed scroll having a spiral body (scroll wrap) projecting on an end plate and a turning scroll, a compression chamber (internal compression) formed between the fixed scroll and the turning scroll Among the chamber X and the outer compression chamber Y), the compression chamber (X1, Y1) immediately before opening to the discharge port and the inside of the casing communicate with each other by a relief port (bypass port), and the compression chamber (X X1, Y1) is provided with a relief valve (check valve) that allows only the flow into the casing, and each fluid in the compression chamber (X1, Y1) immediately before opening to the discharge port is transferred to each compression chamber (X1, Y1). A stage in which the ratio of the volume of each compression chamber (X1, Y1) to the volume of each compression chamber (X, Y1) when the fluid is closed in the inner compression chamber X and the outer compression chamber Y) is the same value. [That is, {the volume V _in (0) of the inner compression chamber X in volume V _in (a) / confining when X1} = {Y1 volume of the outer compression chamber Y when the volume V _out (a) / confining the There is one in which the relief port is opened at a position where relief is sequentially performed in the casing with a phase difference at the stage where V _out (0)} is reached (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-098308 (Claim 1, FIG. 4)

  In an ideal state where there is no leakage of high-pressure gas fluid between the compression chambers, the pressure increase due to the volume reduction of each compression chamber (inner compression chamber X, outer compression chamber Y) is caused by the volume decrease of each compression chamber and the high pressure in each compression chamber. It depends on the temperature rise of the gas fluid. However, between adjacent compression chambers, there are minute gaps between the compression chambers due to the processing accuracy of each scroll, thermal deformation, etc., and the gas fluid leaks from the high-pressure side compression chamber to the low-pressure side compression chamber. Therefore, the pressure increase in the compression chamber on the low pressure side is larger than the ideal state without leakage.

FIG. 3 shows the outer compression chamber Y and the inner compression chamber when the volume V _out (0) of the outer compression chamber Y when closed is 20 cc and the volume V _in (0) of the inner compression chamber X when closed is 16 cc. FIG. 6 is a diagram showing the relationship between the volume [cc] of the compression chamber X and the pressure ratio. FIG. 6 shows the compression volume ratio of each of the outer compression chamber Y and the inner compression chamber X and the pressure ratio in consideration of leakage of the high-pressure gas fluid. It is a figure which shows the relationship.

As shown in FIG. 3, the confining volume V _out (0) of the outer compression chamber Y is larger than the confining volume V _in (0) of the inner compression chamber X ( _in the example of FIG. 3, V _in (0) / V _out (0) = 16 cc / 20 cc = 0.8) In the asymmetric scroll compressor, when the pressure in the outer compression chamber Y and the pressure in the inner compression chamber X at the same volume are compared, the outer compression chamber Y is a higher pressure (in FIG. 3, the suction pressure is 1 and is shown as a pressure ratio). Therefore, as shown in FIG. 6, the pressure in the same compression volume ratio is higher in the inner compression chamber X than in the outer compression chamber Y due to the inflow of the gas fluid from the adjacent outer compression chamber Y to the inner compression chamber X. (The pressure in the inner compression chamber X in consideration of leakage is higher than the ideal state without leakage as indicated by the arrow M in FIG. 2-4. This is because the gas fluid flows in.)

That is, as shown in FIG. 6, the pressure in the inner compression chamber X and V _in (x) / V _in (0) = V _out (x) / V _out (0) are compared with the pressure in the outer compression chamber Y. Then, the pressure in the inner compression chamber X is higher than the pressure in the outer compression chamber Y. That is, even when the compression volume ratio is the same, the pressure in actual operation where the high-pressure gas fluid leaks is higher in the inner compression chamber X.

  Therefore, when the bypass port is provided at a position where the compression volume ratio is the same in the inner compression chamber X and the outer compression chamber Y as in the background art described above, the inner compression chamber X has a higher pressure than the bypass port. It will communicate with. That is, a difference occurs in the pressure of at least one compression chamber with respect to the predetermined pressure at which bypass should be started. When the pressure in the outer compression chamber Y is set to the predetermined pressure, the pressure in the inner compression chamber X is excessive. Since the compressor is in a compressed state and the scroll compressor performs useless overcompression work, the operation efficiency is lowered.

  The present invention has been made in view of the above, and an object of the present invention is to obtain an asymmetric scroll compressor with high operating efficiency.

In order to solve the above-described problems and achieve the object, the present invention provides a closed volume V _in (0) of the inner compression chamber X formed inside the orbiting scroll wrap in the wrap groove of the fixed scroll. An asymmetric type compression chamber smaller than the confining volume V _out (0) of the outer compression chamber Y formed outside the orbiting scroll wrap, and a fixed scroll end plate, and the orbiting scroll is provided in the outer compression chamber When the bypass turning angle θ _out turns from the closing angle position of Y and the closing volume V _out (0) of the outer compression chamber Y is reduced to the predetermined bypass volume V _out (a), the outer compression is performed. An outer compression chamber bypass port with a check valve that communicates the front end of the chamber Y with the discharge chamber, and an end plate of the fixed scroll, and the orbiting scroll bypasses the inner compression chamber X from the closed angle position. and θ _in turning, the internal pressure The tip portion of the compression chamber X of the attached non-return valve communicating with the discharge chamber when the chamber was closed narrowing reduces the volume V _in (0) of the X becomes a predetermined bypass volume V _in (a) In the scroll compressor provided with a compression chamber bypass port, the bypass turning angle of the orbiting scroll so that V _in (a) / V _in (0)> V _out (a) / V _out (0) It is characterized _in that θ _out and θ _in are set.

  The scroll compressor according to the present invention has an effect that the bypass pressure in actual operation is substantially the same in the inner compression chamber X and the outer compression chamber Y, and the operation efficiency is improved.

  Embodiments of a scroll compressor according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

FIG. 1 is a longitudinal sectional view of an embodiment of a scroll compressor according to the present invention, and FIG. 2A is a plan view of the compression unit 4 in a closed position of the outer compression chamber Y (a turning angle of the turning scroll 42 is 0 °). Fig. 2-2 is a transverse sectional view, Fig. 2-2 is a transverse sectional view of the compression section 4 at a turning angle of 90 °, and Fig. 2-3 is a compression section at a turning angle of 180 ° (closed position of the inner compression chamber X). 4 is a cross-sectional view of the compression unit 4 at a turning angle of 258 ° (bypass turning angle θ _out = 258 °), and FIG. 2-5 is a turning angle of 373 ° ( FIG. 3 is a cross-sectional view of the compression unit 4 at a bypass swirl angle θ _in = 373 ° −180 ° = 193 °), and FIG. 3 is a diagram showing the relationship between the volume and pressure ratio of the outer compression chamber Y and the inner compression chamber X. 4 is a diagram showing the relationship between the turning angle of the orbiting scroll and the pressure ratio, and FIG. 5 shows the pressure in the inner compression chamber X. It is a figure which shows the relationship between a compression turning angle and a compression volume ratio.

  As shown in FIG. 1, a scroll compressor 1 according to an embodiment includes a cylindrical sealed casing 2, a main frame 3 installed on the upper part of the sealed casing 2, and a compression unit 4 installed above the main frame 3. And an electric motor 5 that is installed in an electric motor chamber 24 below the main frame 3 and that drives the compression unit 4.

  The main frame 3 is formed in a disk shape, the outer peripheral portion is fixed to the inner wall surface of the hermetic casing 2, and a bearing 31 that supports the rotating shaft 6 of the electric motor 5 is provided in the lower center portion. A circular two-stage recess 3a for accommodating the orbiting scroll 42 is formed.

  The space above the compression unit 4 is a discharge chamber 23 into which the high-pressure refrigerant (discharge gas) compressed by the compression unit 4 is discharged. The discharge chamber 23 is provided in the fixed scroll 41 and the frame 3 described later. The motor chamber 24 communicates with a discharge pipe 26 fixed to the hermetic casing 2 through a communication hole or notch that is not connected.

  The fixed scroll 41 which is formed in a disk shape and whose outer peripheral part is bolted to the outer peripheral part of the frame 3 is provided with a suction pipe 25 for sucking into the compression part 4 low-pressure refrigerant (intake gas) after an external refrigeration cycle (not shown). , And are connected through the sealed casing 2. The compression unit 4 sucks low-pressure refrigerant that has finished an external refrigeration cycle (not shown) through the suction pipe 25, compresses the low-pressure refrigerant, and discharges it as a high-pressure refrigerant to the discharge chamber 23, via the motor chamber 24 and the discharge pipe 26. To the refrigeration cycle.

  In the scroll compressor 1 according to the embodiment, since the electric motor 5 has no will if it is changed from a normal conventional electric motor, detailed description thereof is omitted. The electric motor 5 is supplied with electric power from a terminal block 51 installed on the outer peripheral portion of the hermetic casing 2.

  As shown in FIGS. 1 and 2-1, the compression section 4 includes a fixed scroll 41 having a spiral fixed scroll wrap 41b (and a wrap groove 41c) formed on the lower surface of a disk-shaped end plate 41a, And an orbiting scroll 42 in which a spiral orbiting scroll wrap 42b (and a wrap groove 42c) indicated by a broken line is formed on the upper surface of the end plate 42a.

  As shown in FIG. 2A, the fixed and orbiting scroll wraps 41b and 42b are meshed with each other, whereby an inner compression chamber X is formed inside the orbiting scroll wrap 42b in the wrap groove 41c. An outer compression chamber Y is formed outside the orbiting scroll wrap 42b.

  The end plate 41 a of the fixed scroll 41 is provided with a discharge port 41 d for discharging the high-pressure refrigerant compressed in the inner compression chamber X and the outer compression chamber Y to the discharge chamber 23 at the center thereof. A bottomed suction hole 41 e that communicates the lap groove 41 c of the fixed scroll 41 and the suction pipe 25 is provided on the outer peripheral portion of the fixed scroll 41. A check valve 45 that prevents the refrigerant from flowing backward in the direction of the suction pipe 25 is installed in the suction hole 41e.

  The check valve 45 includes a valve body 45a that slides in the suction hole 41e, and a coil spring that presses the valve body 45a against a valve seat formed at the lower end of the suction pipe 25 and biases the check valve 45 in a closing direction. 45b.

  A rotating shaft 6a that is eccentric with the rotating shaft 6 is formed integrally with the upper end portion of the rotating shaft 6 of the electric motor 5, and the rotating shaft 6a is a bearing portion 42d formed on the lower surface side of the end plate 42a of the orbiting scroll 42. Has been inserted. When the rotating shaft 6 rotates, the orbiting shaft 6 a revolves around the rotating shaft 6, and the orbiting scroll 42 revolves without rotating about the fixed scroll 41 via the Oldham ring 43. The volume of the compression chamber Y is reduced.

  The rotating shaft 6 and the turning shaft 6a are provided with an oil passage 6b for supplying the lubricating oil O stored at the bottom of the hermetic casing 2 to the compression unit 4 side. Lubricating oil O stored at the bottom of the hermetic casing 2 is sucked by a trochoid pump 63 driven by the rotating shaft 6, and is supplied via a lubricating oil pipe 62 attached to a lower bearing 61 that supports the rotating shaft 6. It flows into the path 6b and is supplied to the compression part 4 side, and lubricates the sliding part of the compression part 4 including the Oldham ring 43, the bearing 31 and the like.

As shown in FIG. 2A, the turning shaft 6 a is eccentric in the lower left 45 ° direction, and the winding end 42 e of the turning scroll wrap 42 b is in contact with the outer wall surface of the scroll groove 41 c of the fixed scroll 41. Assuming that the turning angle of the turning scroll 42 is 0 °, the outer compression chamber Y is closed at this time, and the closed volume V _out (0) is obtained.

When the orbiting scroll 42 is turned counterclockwise from the state of the turning angle 0 ° shown in FIG. 2-1 to the state of the turning angle 90 ° shown in FIG. 2-2, the outer compression chamber Y is also reduced in volume by 90. ° Moved to the swivel position, and as shown in FIGS. 3 and 4, V _out (x) / V _out (0) is 0.90 (= 18 cc / 20 cc), and the pressure ratio considering leakage is approximately 1.13.

As shown in Figure 2-3, when the orbiting scroll 42 is 180 ° pivot, the outer compression chamber Y is moved to a position 180 ° turns by further reducing the volume, as shown in FIGS. 3 and 4, V _out (x) / V _out (0) is 0.80 (= 16 cc / 20 cc), and the pressure ratio in consideration of leakage is 1.31. At this time, the winding end 42e of the orbiting scroll wrap 42b contacts the inner wall surface of the scroll groove 41c of the fixed scroll 41, the inner compression chamber X is closed, and the closed volume V _in (0) is obtained. V _out (x) / V _out (0) = V _in (0) / V _out (0) = 0.80.

Thus, in the scroll compressor 1 of the embodiment, the closing swirl angle of the outer compression chamber Y and the closing swirl angle of the inner compression chamber X are 180 ° out of phase, and the confining volume V of the inner compression chamber X is different. _in (0) is smaller than the confining volume V _out (0) of the outer compression chamber Y (V _in (0) / V _out (0) = 0.80), which is an asymmetric scroll compressor.

As shown in FIGS. 2-4 and 4, the orbiting scroll 42 orbits the bypass turning angle θ _out = 258 ° while flowing the high-pressure refrigerant from the outer compression chamber Y to the inner compression chamber X (arrow M direction). As shown in FIG. 3, when V _out (a) / V _out (0) is 0.713 (= 14.26 cc / 20 cc) and the pressure ratio considering leakage is 1.5, the outer compression chamber A bypass port 41f with a check valve 46 (see FIG. 1) communicating the Y end portion Ya with the discharge chamber 23 is provided, and bypasses the high-pressure refrigerant when the pressure ratio becomes 1.5.

  The check valve 46 is configured by a spring plate that is screwed to the end plate 41a of the fixed scroll 41 and closes the bypass port 41f. When the pressure in the discharge pressure chamber 23 is higher than the pressure of the compression unit 4, the check valve 46 closes the bypass port 41f. It is like that. The check valve presser 47 is screwed to the end plate 41a together with the check valve 46, so that the check valve 46 is not opened too much and is not damaged by the ejection of the high-pressure refrigerant.

As shown in FIGS. 2-5 and 4, while the high-pressure refrigerant enters from the outer compression chamber Y to the inner compression chamber X (in the direction of arrow M), the orbiting scroll 42 is 373 ° (from the closing angle of the inner compression chamber X). Bypass turning angle θ _in = 193 °), and as shown in FIG. 3, V _in (a) / V _in (0) is 0.732 (= 11.71 cc / 16 cc), and the pressure ratio considering leakage Is provided with a bypass port 41g with a check valve 46 (see FIG. 1) for communicating the tip Xa of the inner compression chamber X with the discharge chamber 23 and bypassing the high-pressure refrigerant. .

  The refrigerant that has not been bypassed while the bypass ports 41f and 41g communicate with the outer compression chamber Y and the inner compression chamber, respectively, causes the orbiting scroll 42 to further rotate, and the compression chambers Y and X become the central portion of the compression section 4. Is compressed again in the process of moving to the center, reaches the center, communicates with the discharge hole 41d, and is discharged into the discharge chamber 23.

As described above, in the scroll compressor 1 of the embodiment, (V _in (a) / V _in (0) = 0.732)> (V _out (a) / V _out (0) = 0.713 As shown in FIG. 5, the bypass turning angle θ _in = 193 ° of the inner compression chamber X is V _in (a) / V _in (0) = V _out (a) / V _out (0 ) = 0.713, which is 14 ° smaller than the turning angle 207 °.

How much smaller the bypass turning angle θ _in = 193 ° of the inner compression chamber X than the turning angle at which V _in (a) / V _in (0) = V _out (a) / V _out (0) Is the processing accuracy of the compression section 4 of the scroll compressor 1, thermal deformation, the number of turns of the orbiting scroll wrap, the phase difference between the closed turning angle of the outer compression chamber Y and the closed turning angle of the inner compression chamber X, the refrigerant pressure and the rotation. Although it depends on the amount of high-pressure refrigerant leakage that varies depending on the speed, etc., the bypass pressure in actual operation of the outer compression chamber Y and the inner compression chamber X should be substantially the same by setting the angle to be reduced to 5 ° to 30 °. Can do.

  In the present embodiment, a pair of bypass ports are provided in each compression chamber, and when the pressure ratio becomes 1.5, the high pressure refrigerant in each compression chamber is bypassed. Two or three different bypass ports may be provided to bypass the high-pressure refrigerant at different bypass pressures. Further, the phase difference between the closing swirl angle of the outer compression chamber Y and the closing swirl angle of the inner compression chamber X is not necessarily 180 °, and may be approximately 90 °.

  As described above, the scroll compressor according to the present invention is suitable for gas compressors such as refrigerators, freezers, and air conditioners that require quietness and energy saving.

It is a longitudinal cross-sectional view which shows the Example of the scroll compressor concerning this invention. It is a cross-sectional view of the compression part in the closed position of an outer compression chamber. It is a cross-sectional view of the compression part at a turning angle of 90 °. It is a cross-sectional view of the compression part at a turning angle of 180 °. It is a cross-sectional view of the compression part at a turning angle of 258 °. It is a cross-sectional view of the compression part at a turning angle of 373 °. It is a figure which shows the relationship between the compression volume of an outer compression chamber and an inner compression chamber, and a pressure ratio. It is a figure which shows the relationship between the turning angle of a turning scroll, and a pressure ratio. It is a figure which shows the relationship between the compression turning angle of an inner compression chamber, and compression volume ratio. It is a figure which shows the relationship between the compression volume ratio of each of an outer compression chamber and an inner compression chamber, and the pressure ratio which considered the leak of the high pressure gas fluid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Sealed casing 23 Discharge chamber 24 Electric motor chamber 25 Suction pipe 26 Discharge pipe 3 Main frame 4 Compression part 41 Fixed scroll 41b Fixed scroll wrap 41d Discharge port 41f Outer compression chamber bypass port 41g Inner compression chamber bypass port 42 Turning scroll 42b Orbiting scroll wrap 42e End of winding 41a, 42a End plate 41c, 42c Lap groove 43 Oldham ring 46 Check valve 5 Electric motor 6 Rotating shaft 6a Rotating shaft O Lubricating oil X Inner compression chamber Xa End of inner compression chamber Y Outer compression chamber Ya Outer compression chamber tip V _in (0) Inner compression chamber confining volume V _in (a) Inner compression chamber bypass start volume V _out (0) Outer compression chamber confining volume V _out (a) Volume of outer compression chamber at start of bypass θ _in Bypass swivel angle of inner compression chamber θ _out Bypass swirl angle of outer compression chamber

Claims (2)

The confining volume V _in (0) of the inner compression chamber X formed inside the orbiting scroll wrap in the wrap groove of the fixed scroll is the confining volume of the outer compression chamber Y formed outside the orbiting scroll wrap. An asymmetric compression chamber smaller than V _out (0);
Provided on the end plate of the fixed scroll, the orbiting scroll turns by the bypass turning angle θ _out from the closing angle position of the outer compression chamber Y, and the closing volume V _out (0) of the outer compression chamber Y decreases. An outer compression chamber bypass port with a check valve that communicates the tip of the outer compression chamber Y with the discharge chamber when a predetermined bypass volume V _out (a) is reached;
Provided on the end plate of the fixed scroll, the orbiting scroll orbits the bypass turning angle θ _in from the closing angle position of the inner compression chamber X, and the closing volume V _in (0) of the inner compression chamber X decreases. An inner compression chamber bypass port with a check valve that communicates the tip of the inner compression chamber X with the discharge chamber when a predetermined bypass volume V _in (a) is reached;
In the scroll compressor with
The scroll characterized by setting the bypass turning angles θ _out and θ _in of the orbiting scroll so that V _in (a) / V _in (0)> V _out (a) / V _out (0). Compressor. Claims, characterized in that the bypass pivot angle theta _in, and _{V in (a) / V in} (0) = V out (a) / V out (0) and than turning angle becomes smaller 5 ° to 30 ° Item 2. The scroll compressor according to Item 1.

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