JP6932797B2 - Scroll compressor - Google Patents

Description

The present invention relates to a three-dimensional compression type scroll compressor.

The scroll compressor includes a pair of fixed scrolls and swirl scrolls in which spiral wraps are erected on an end plate, and the spiral laps (spiral walls) of the pair of fixed scrolls and swirl scrolls face each other. By engaging with each other by shifting the phase by 180 °, a sealed compression chamber is formed between both scrolls to compress the fluid. In such a scroll compressor, the lap height of the spiral laps of the fixed scroll and the swirl scroll is made uniform over the entire circumference in the spiral direction, and the compression chamber is moved from the outer peripheral side to the inner peripheral side while reducing the volume. Generally, a two-dimensional compression structure is used to compress the fluid sucked into the compression chamber in the circumferential direction of the spiral wrap.

On the other hand, in order to improve the efficiency and reduce the size and weight of the scroll compressor, a step portion is provided at a predetermined position along the spiral direction of the spiral lap of the fixed scroll and the swirl scroll, and the step portion is provided. By making the lap height on the outer peripheral side of the spiral wrap higher than the lap height on the inner peripheral side at the boundary, and making the axial height of the compression chamber higher than the height on the inner peripheral side on the outer peripheral side of the spiral wrap. , A three-dimensional compression type scroll compressor having a structure that compresses a fluid in both the circumferential direction and the height direction of the spiral wrap is provided.

As such a three-dimensional compression type scroll compressor, for example, as shown in Patent Document 1, a step portion on the end plate side is formed on both the end plates of the fixed scroll and the swirl scroll, and the fixed scroll and the swirl scroll have a stepped portion. It is known that both spiral wraps are provided with a lap-side step portion corresponding to an end plate-side step portion.

Further, as shown in Patent Document 2, an end plate side step portion is provided on the end plate of one of the fixed scroll and the swivel scroll, and the end plate side step portion is provided on the spiral wrap of the other scroll. It is known that a step portion on the lap side corresponding to the above is formed.

Japanese Unexamined Patent Publication No. 2002-5052 Special Publication No. 60-17956 (see Fig. 8)

As in Patent Document 1, when both the fixed scroll and the swivel scroll are provided with stepped portions and the heights of these stepped portions are equal, both scrolls have the same shape. Therefore, since the volumes of the pair of compression chambers facing each other across the center of the fixed scroll are theoretically equal at each turning angle, the pressures of these compression chambers are equal.
However, when the heights of the stepped portions of the fixed scroll and the swivel scroll are different, the shapes of both scrolls are not the same. Therefore, the volumes of the pair of compression chambers facing each other across the center of the fixed scroll are not always equal at each turning angle, and the pressures of these compression chambers are different.
Similarly, as in Patent Document 2, an end plate side step portion is provided on the end plate of one of the fixed scroll and the swivel scroll, and the spiral wrap of the other scroll is provided on the end plate side step portion. Even if the corresponding lap side step portion is provided, the shapes of both scrolls are not the same. Therefore, the volumes of the pair of compression chambers facing each other across the center of the fixed scroll are not always equal at each turning angle, and the pressures of these compression chambers are different.

As described above, if the pressures of the pair of compression chambers facing each other across the center of the fixed scroll are different, one of the compression chambers may be excessively compressed, which causes a decrease in compression efficiency.
In particular, in an intermediate period such as spring when a low pressure ratio is required, overcompression of one of the compression chambers becomes remarkable.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a scroll compressor capable of preventing excessive compression.

In order to solve the above problems, the scroll compressor of the present invention employs the following means.
That is, the scroll compressor according to the present invention has a fixed scroll having a spiral wall body erected on one side surface of the end plate and a spiral wall body erected on one side surface of the end plate. A swivel scroll that is supported so that it can revolve around while being prevented from rotating by engaging the walls with each other, and a discharge port that discharges the fluid compressed by both scrolls. One end plate is provided with an end plate side step portion formed on one side surface so that the height is high on the central portion side and low on the outer terminal side along the vortex of the wall body. The other wall of the scroll is provided with a wall-side step that corresponds to the end plate-side step and is formed so that the height is low on the center side of the vortex and high on the outer end side, and the suction deadline is provided. After the above is performed to form a pair of compression chambers, the pair of compression chambers are configured so that the volume change ratios of the pair of compression chambers are different from each other due to the stepped end plate portion in the middle of the swivel movement, so that swirl at the time of discharge is performed. In a scroll compressor configured so that the pressures in the pair of compression chambers at the corners are different from each other, the compression chamber having the higher compression chamber pressure and the compression chamber having the lower pressure among the pair of compression chambers. It is characterized in that it communicates with the discharge port before.

When one of the fixed scroll and the swivel scroll is provided with a step portion on the end plate side and the other scroll is provided with a step portion on the wall body side, the shapes of both scrolls are not the same. Therefore, the pressures of the pair of compression chambers facing each other across the center of the fixed scroll are not the same. Therefore, in the present invention, the compression chamber having the higher pressure among the pair of compression chambers communicates with the discharge port before the compression chamber having the lower pressure. This makes it possible to avoid overcompression.
For example, if the swivel scroll has a step on the end plate side and the fixed scroll has a step on the wall side, the compression chamber on the ventral side (inner circumference side) across the wall of the fixed scroll comes first. Communicate with the discharge port.

Further, the scroll compressor according to the reference example of the present invention includes a fixed scroll having a spiral wall body erected on one side surface of the end plate and a spiral wall body erected on one side surface of the end plate. It is provided with a swivel scroll that is supported so that it can revolve and swivel while being prevented from rotating by meshing the walls with each other, and a discharge port for discharging the fluid compressed by both the scrolls. Each end plate of the scroll is provided with an end plate side step portion formed on one side surface so that the height is high on the center side and low on the outer end side along the vortex of the wall body. Each wall of the scroll is provided with a wall-side step that corresponds to the end plate side step and is formed so that the height is low on the center side of the vortex and high on the outer end side. In a scroll compressor in which the height of the step portion on the end plate side and the step portion on the wall body side are different, the compression chamber having the higher pressure is the pair of compression chambers facing each other with the center of the fixed scroll sandwiched. It is characterized in that it communicates with the discharge port before the compression chamber having a lower pressure.

The end plate side step portion is formed on both the fixed scroll and the swivel scroll, and the wall body side step portion corresponding to the end plate side step portion is formed on the wall body of the fixed scroll and the swivel scroll, and the corresponding end plate side step is further formed. If the heights of the portion and the step portion on the wall body side are different, the shapes of both scrolls are not the same. Therefore, the pressures of the pair of compression chambers facing each other across the center of the fixed scroll are not the same. Therefore, in the present invention, the compression chamber having the higher pressure among the pair of compression chambers communicates with the discharge port before the compression chamber having the lower pressure. This makes it possible to avoid overcompression.
For example, if the step portion on the end plate side of the swivel scroll is higher than the step portion on the wall body side of the fixed scroll, the compression chamber on the ventral side (inner circumference side) across the wall body of the fixed scroll. Communicate with the discharge port first.

Further, the scroll compressor according to the reference example of the present invention includes a fixed scroll having a spiral wall body erected on one side surface of the end plate and a spiral wall body erected on one side surface of the end plate. A swivel scroll that meshes with each other and is supported so that it can revolve around while being prevented from rotating, a discharge port that discharges a fluid compressed by both scrolls, and a discharge port. An extraction port for discharging a fluid having a predetermined pressure or higher is provided before the fluid is discharged, and one of the end plates of both scrolls has a height along the vortex of the wall body on one side surface. An end plate side step portion formed so as to be high on the central portion side and low on the outer end side is provided, and the other wall body of both scrolls has a height corresponding to the end plate side step portion. In a scroll compressor provided with a wall-side step portion formed so as to be low on the center side of the vortex and high on the outer end side, the pressure of the pair of compression chambers facing each other across the center of the fixed scroll is high. The higher compression chamber communicates with the extraction port before the lower pressure chamber.

When one of the fixed scroll and the swivel scroll is provided with a step portion on the end plate side and the other scroll is provided with a step portion on the wall body side, the shapes of both scrolls are not the same. Therefore, the pressures of the pair of compression chambers facing each other across the center of the fixed scroll are not the same. Therefore, in the present invention, the compression chamber having the higher pressure among the pair of compression chambers communicates with the extraction port (so-called bypass port) before the compression chamber having the lower pressure. This makes it possible to avoid overcompression.
For example, if the swivel scroll has a step on the end plate side and the fixed scroll has a step on the wall side, the compression chamber on the ventral side (inner circumference side) across the wall of the fixed scroll comes first. Communicate with the extraction port.

Further, the scroll compressor according to the reference example of the present invention includes a fixed scroll having a spiral wall body erected on one side surface of the end plate and a spiral wall body erected on one side surface of the end plate. A swivel scroll that meshes with each other and is supported so that it can revolve around while being prevented from rotating, a discharge port that discharges a fluid compressed by both scrolls, and a discharge port. Each end plate of both scrolls is provided with an extraction port that discharges a fluid above a predetermined pressure prior to the discharge of the fluid, on one side of the scroll, the height of which is along the vortex of the wall. An end plate side step portion formed so as to be high on the central portion side and low on the outer end side is provided, and each wall body of both scrolls corresponds to the end plate side step portion and has a vortex height. In a scroll compressor in which a wall-side step portion formed so as to be low on the central portion side and high on the outer terminal side is provided, and the height of the end plate-side step portion and the height of the wall-side step portion are different, the fixing is performed. Of the pair of compression chambers facing each other across the center of the scroll, the compression chamber having a higher pressure communicates with the extraction port before the compression chamber having a lower pressure.

The end plate side step portion is formed on both the fixed scroll and the swivel scroll, and the wall body side step portion corresponding to the end plate side step portion is formed on the wall body of the fixed scroll and the swivel scroll, and the corresponding end plate side step is further formed. If the heights of the portion and the step portion on the wall body side are different, the shapes of both scrolls are not the same. Therefore, the pressures of the pair of compression chambers facing each other across the center of the fixed scroll are not the same. Therefore, in the present invention, the compression chamber having the higher pressure among the pair of compression chambers communicates with the extraction port (so-called bypass port) before the compression chamber having the lower pressure. This makes it possible to avoid overcompression.
For example, if the step portion on the end plate side of the swivel scroll is higher than the step portion on the wall body side of the fixed scroll, the compression chamber on the ventral side (inner circumference side) across the wall body of the fixed scroll. Communicate with the discharge port first.

Since it is decided that the compression chamber having the higher pressure is communicated with the discharge port or the extraction port first, excessive compression can be prevented.

It is a vertical sectional view which showed the scroll compressor which concerns on one Embodiment of this invention. It is a cross-sectional view which showed the meshing of a fixed scroll and a swivel scroll. It is a graph which showed the volume change of the ventral compression chamber and the dorsal compression chamber. (A) is an enlarged cross-sectional view showing the engagement of the central portion of the fixed scroll and the swivel scroll, (b) is a cross-sectional view showing the position adjustment of the discharge port, and (c) is a modified example. It is a cross-sectional view which showed the position adjustment of the discharge port as. It is a graph which showed the volume change of the ventral compression chamber and the dorsal compression chamber which concerns on one Embodiment. It is sectional drawing which showed the engagement of the fixed scroll and the swivel scroll which concerns on a reference embodiment. As a comparative example, it is a cross-sectional view showing the meshing of a fixed scroll and a swivel scroll. It is a graph which showed the volume change of the ventral compression chamber and the dorsal compression chamber which concerns on a reference embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
[Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, the scroll compressor 1 includes a housing 2 that constitutes an outer shell. The housing 2 has a cylindrical shape in which the front end side (left side in the drawing) is opened and the rear end side is sealed. A closed space is formed in the closed space, and the scroll compression mechanism 5 and the drive shaft 6 are incorporated in the closed space.

The drive shaft 6 is rotatably supported by the front housing 3 via a main bearing 7 and an auxiliary bearing 8, and the front housing 3 is provided at a front end portion protruding outward from the front housing 3 via a mechanical seal 9. A pulley 11 rotatably installed on the outer peripheral portion via a bearing 10 is connected via an electromagnetic clutch 12, and power can be transmitted from the outside. A crank pin 13 eccentric by a predetermined dimension is integrally provided at the rear end of the drive shaft 6, and includes a swivel scroll 16 of a scroll compression mechanism 5 described later, a drive bush having a variable swivel radius, and a drive bearing. It is connected via a known driven crank mechanism 14.

The scroll compression mechanism 5 engages the pair of fixed scrolls 15 and the swivel scroll 16 with a 180 ° phase shift, so that the pair of compression chambers facing each other with the center of the fixed scroll 15 sandwiched between the scrolls 15 and 16. 17 is formed, and the fluid (refrigerant gas) is compressed by moving the compression chamber 17 from the outer peripheral position to the central position while gradually reducing the volume. The fixed scroll 15 is provided with a discharge port 18 for discharging compressed gas at a central portion, and is fixedly installed on the bottom wall surface of the housing 2 via bolts 19. Further, the swivel scroll 16 is connected via a driven crank mechanism 14 of the crank pin 13 of the drive shaft 6, and is freely supported on the thrust bearing surface of the front housing 3 via a known rotation prevention mechanism 20 to revolve and swivel drive. There is.

An O-ring 21 is provided on the outer periphery of the end plate 15A of the fixed scroll 15, and the O-ring 21 is brought into close contact with the inner peripheral surface of the housing 2, so that the internal space of the housing 2 becomes the discharge chamber 22 and the suction chamber 23. It is divided into. A discharge port 18 is opened in the discharge chamber 22, and the compressed gas from the compression chamber 17 is discharged, from which the compressed gas is discharged to the refrigeration cycle side. Further, the suction chamber 23 is opened with a suction port 24 provided in the housing 2, and the low pressure gas circulated in the refrigeration cycle is sucked in, and the refrigerant gas is sucked into the compression chamber 17 through the suction chamber 23. It has become like.

The pair of fixed scrolls 15 and swivel scrolls 16 have spiral wraps 15B and 16B erected as walls on the end plates 15A and 16A, respectively. The tooth tip surface 15C of the fixed scroll 15 comes into contact with the tooth bottom surface 16D of the swivel scroll 16, and the tooth tip surface 16C of the swivel scroll 16 comes into contact with the tooth bottom surface 15D of the fixed scroll 15.
The end plate 16A of the swivel scroll 16 is provided with an end plate side step portion 16E formed so that its height is high on the central portion side and low on the outer terminal side along the vortex of the spiral wrap 16B. .. Specifically, as shown in FIG. 2, the end plate side step portion 16E is provided at a position 180 ° from the winding end position of the spiral wrap 16B of the swirl scroll 16.

The spiral wrap 15B of the fixed scroll 15 is provided with a lap-side step portion 15E corresponding to the end plate side step portion 16E of the swirl scroll 16 described above, and the height is low on the central portion side of the vortex and high on the outer end side. Has been done. Specifically, as shown in FIG. 2, a lap-side step portion 15E is provided at a position 360 ° from the winding end position of the spiral wrap 15B of the fixed scroll 15.

That is, the end plate side step portion 16E is provided only on the end plate 16A of the swivel scroll 16, and the lap side step portion 15E is provided only on the spiral wrap 15B of the fixed scroll 15. Therefore, the spiral wrap 16B of the swirl scroll 16 is not provided with a step portion, and the tips of the spiral wrap 16B are set to have the same height. Further, the end plate 15A of the fixed scroll 15 is not provided with a stepped portion and has a flat surface.

As shown in FIG. 2, the compression chamber 17 is formed of at least one pair of compression chambers 17A and 17B facing each other with the center of the fixed scroll 15 in between. In order to distinguish the pair of compression chambers 17A and 17B, in FIG. 2, the compression chamber formed on the ventral side (inner peripheral side) of the spiral wrap 15B of the fixed scroll 15 is designated as the ventral compression chamber 17A, and the fixed scroll. The compression chamber formed on the dorsal side (outer peripheral side) of the spiral wrap 15B of 15 is defined as the dorsal compression chamber 17B.

FIG. 3 shows the volume change of the ventral compression chamber 17A and the dorsal compression chamber 17B. In the figure, the horizontal axis shows the turning angle θ *, and the vertical axis shows the volumes of the compression chambers 17A and 17B.
As can be seen from FIG. 3, after the suction deadline is performed at the turning angle α1 and a pair of compression chambers are formed on the outermost peripheral side, the ventral compression chamber 17A and the dorsal compression chamber 17B are compressed with different volumes. The compression is performed up to the turning angle at which the volume becomes the same at the turning angle α2 and is discharged. Since the volume change rate (inclination) of the ventral compression chamber 17A is larger than that of the dorsal compression chamber 17B, the pressure of the ventral compression chamber 17A is higher than that of the dorsal compression chamber 17B, and the ventral compression chamber 17A has a higher pressure than the dorsal compression chamber 17B. The discharge pressure of 17A may become excessive.

Therefore, in the present embodiment, as shown in FIGS. 4A and 4B, the shape of the discharge port 18 is adjusted so that the ventral compression chamber 17A becomes the discharge port 18 before the dorsal compression chamber 17B. It is designed to communicate. As a method of adjusting the shape of the discharge port 18, the diameter may be larger than the diameter of the discharge port 18'adjusted so that the ventral compression chamber 17A and the dorsal compression chamber 17B open at the same time. The positions a and b shown in the figure are the ventral compression chamber 17A and the dorsal compression when the discharge port 18'adjusted so that the ventral compression chamber 17A and the dorsal compression chamber 17B open at the same time is used. The communication start position of the chamber 17B is shown. As can be seen from the figure, if the discharge port 18 has a diameter larger than the diameter of the discharge port 18'adjusted so that the ventral compression chamber 17A and the dorsal compression chamber 17B open at the same time, the discharge port 18 has a diameter larger than that of the dorsal compression chamber 17B. First, the ventral compression chamber 17A communicates with the discharge port 18.
As another method for adjusting the shape of the discharge port 18, as shown in FIG. 4C, the diameter of the discharge port 18'adjusted so that the ventral compression chamber 17A and the dorsal compression chamber 17B open at the same time. The center position may be moved to the ventral compression chamber 17A side, that is, to the outside (left side in the drawing) of the spiral wrap 15B of the fixed scroll 15. Alternatively, the cross-sectional shape of the discharge port 18 may be formed into an oval shape or a keyhole shape instead of a circular shape so as to communicate with the ventral compression chamber 17A first.

According to the scroll compressor 1 of the present embodiment, the following effects are obtained.
Of the pair of compression chambers 17A and 17B facing each other across the center of the fixed scroll 15, the ventral compression chamber 17A having the higher pressure communicates with the discharge port before the dorsal compression chamber 17B having the lower pressure. It was decided to. As a result, a step portion 16E is provided on the end plate 16A of the swivel scroll 16, and a step portion 15E corresponding to the step portion 16E is provided on the spiral lap 15B of the other fixed scroll 15 so as to sandwich the center of the fixed scroll 15. Even if the pressures of the pair of compression chambers 17A and 17B facing each other are not the same, overcompression of the ventral compression chambers 17A can be avoided.
Specifically, as shown in FIG. 5, since the ventral compression chamber 17A communicates with the discharge port 18 at a turning angle α3 before the turning angle α4 at which the dorsal compression chamber 17B communicates with the discharge port 18. After the turning angle α3, the ventral compression chamber 17A is not further compressed. As a result, it is possible to avoid that the energy corresponding to the substantially triangular region A1 shown in FIG. 5 causes a power loss and lowers the compression efficiency.

In the present embodiment, the configuration will be described using a configuration in which the end plate side step portion 16E is provided only on the end plate 16A of the swivel scroll 16 and the lap side step portion 15E is provided only on the spiral wrap 15B of the fixed scroll 15. However, the reverse configuration, that is, the configuration in which the end plate side step portion is provided only on the end plate 15A of the fixed scroll 15 and the lap side step portion is provided only on the spiral lap 16B of the swirl scroll 16. The invention can be applied. In this case, since the pressure in the dorsal compression chamber 17B is higher than that in the ventral compression chamber 17A, the dorsal compression chamber 17B is configured to communicate with the discharge port 18 before the ventral compression chamber 17A. do. For example, in FIG. 4A, a notch or a groove is provided on the ventral side of the spiral wrap 16B of the swirl scroll 16 so that a gap is first formed at the position b.

The present invention can also be applied to a scroll compressor in which end plate side step portions are provided on both end plates of a fixed scroll and a swivel scroll as described with reference to Patent Document 1. That is, when the height of the end plate side step portion provided on the end plate of the swivel scroll is higher than the end plate side step portion provided on the end plate of the fixed scroll, the ventral side as in the present embodiment. Since the pressure of the compression chamber 17A is higher than that of the dorsal compression chamber 17B, excessive compression of the ventral compression chamber 17A can be avoided by adjusting the shape of the discharge port. On the other hand, when the height of the end plate side step portion provided on the end plate of the fixed scroll is higher than the end plate side step portion provided on the end plate of the swivel scroll, the dorsal compression chamber 17B is used. Since the pressure is higher than that of the ventral compression chamber 17A, excessive compression of the dorsal compression chamber 17B can be avoided by providing a notch or a groove on the ventral side of the spiral wrap 16B of the swirl scroll 16.

[Reference Embodiment]
Next, a reference embodiment of the present invention will be described with reference to FIGS. 6 to 8.
This reference embodiment differs in that it includes a bypass port in addition to the above embodiment. Therefore, the same reference numerals are given to the same configurations as those in the above embodiment, and the description thereof will be omitted.

The scroll compressor 1 of this reference embodiment has a vertical cross-sectional shape shown in FIG. Further, in the scroll compressor 1 of the present reference embodiment, as shown in FIG. 6, bypass ports (extraction ports) 30A and 30B are formed on the end plate 15A of the fixed scroll 15. The bypass ports 30A and 30B are provided with a check valve or the like that opens when the pressure exceeds a predetermined pressure, and discharges the fluid having a predetermined pressure or higher before the fluid is discharged from the discharge port 18 to prevent excessive compression. Is. One bypass port 30A in FIG. 6 corresponds to the ventral compression chamber 17A and the other bypass port 30B corresponds to the dorsal compression chamber 17B.

In this reference embodiment, as shown in FIG. 6A, when the turning angle β1, the ventral compression chamber 17A communicates with the bypass port 30A, and the dorsal compression chamber 17B does not communicate with the bypass port 30B. Therefore, at this turning angle β1, the fluid for the excess pressure is extracted only from the ventral compression chamber 17A. Then, as shown in FIG. 6B, when the turning angle β2 is reached, the dorsal compression chamber 17B communicates with the bypass port 30B. At this turning angle β2, the ventral compression chamber 17A already communicates with the bypass port 30A.

FIG. 7 shows the communication start timing of the bypass port as a comparative example. In this comparative example, the pressure difference between the ventral compression chamber 17A and the dorsal compression chamber 17B is substantially zero or small enough not to affect the performance, and as shown in FIG. 7A, the swivel is swiveled. Bypass ports 30A and 30B are not in communication with both compression chambers 17A and 17B when the angle β1 is set, and as shown in FIG. 7B, both compression chambers 17A and 17B are simultaneously connected to both compression chambers 17A and 17B when the turning angle β2. It communicates with the bypass ports 30A and 30B.

FIG. 8 shows the pressure change due to the bypass ports 30A and 30B of the present reference embodiment shown in FIG. In the figure, the horizontal axis represents the turning angle and the vertical axis represents the pressure. As can be seen from the figure, the pressure of the ventral compression chamber 17A becomes higher than that of the dorsal compression chamber 17B from around the turning angle β0. Then, as shown in FIG. 6A, the ventral compression chamber 17A starts communicating with the bypass port 30A at the turning angle β1 and is not excessively compressed to the required discharge pressure or more. After that, as shown in FIG. 6B, the dorsal compression chamber 17B starts communicating with the bypass port 30B at the turning angle β2, and the required discharge pressure is adjusted up to the turning angle β3 communicating with the discharge port 18.
On the other hand, as shown in FIG. 7, when both compression chambers 17A and 17B start communicating with the bypass ports 30A and 30B at the same time at the turning angle β2, the ventral compression chambers 17A and 17B are shown in FIG. 17A will be over-compressed above the required discharge pressure. Therefore, the energy corresponding to the substantially triangular region A2 shown in FIG. 8 becomes a power loss and reduces the compression efficiency.

According to the scroll compressor 1 of the present reference embodiment, the following effects are obtained.
Of the pair of compression chambers 17A and 17B facing each other across the center of the fixed scroll 15, the ventral compression chamber 17A having the higher pressure is connected to the bypass port 30A before the dorsal compression chamber 17B having the lower pressure. I decided to communicate. As a result, a step portion 16E is provided on the end plate 16A of the swivel scroll 16, and the spiral wrap 15B of the other fixed scroll 15 has a stepped shape corresponding to the step portion 16E, and is positive with the center of the fixed scroll 15 interposed therebetween. Even if the pressures of the pair of compression chambers 17A and 17B are not the same, excessive compression of the ventral compression chambers 17A can be avoided.

In this reference embodiment, it is assumed that the end plate side step portion 16E is provided only on the end plate 16A of the swivel scroll 16 and the lap side step portion 15E is provided only on the spiral wrap 15B of the fixed scroll 15. However, the reverse configuration, that is, the configuration in which the end plate side step portion is provided only on the end plate 15A of the fixed scroll 15 and the lap side step portion is provided only on the spiral lap 16B of the swirl scroll 16. The invention can be applied. In this case, the pressure in the dorsal compression chamber 17B is higher than that in the ventral compression chamber 17A, so that the dorsal compression chamber 17B is bypassed so as to communicate with the bypass port 30B before the ventral compression chamber 17A. Adjust the position of port 30B.

The present invention can also be applied to a scroll compressor in which end plate side step portions are provided on both end plates of a fixed scroll and a swivel scroll as described with reference to Patent Document 1. That is, when the height of the end plate side step portion provided on the end plate of the swivel scroll is higher than the end plate side step portion provided on the end plate of the fixed scroll, the ventral side as in the reference embodiment. Since the pressure of the compression chamber 17A is higher than that of the dorsal compression chamber 17B, overcompression of the ventral compression chamber 17A can be avoided by adjusting the position of the bypass port 30A. On the other hand, when the height of the end plate side step portion provided on the end plate of the fixed scroll is higher than the end plate side step portion provided on the end plate of the swivel scroll, the dorsal compression chamber 17B is used. Since the pressure is higher than that of the ventral compression chamber 17A, overcompression of the dorsal compression chamber 17B can be avoided by adjusting the position of the bypass port 30B.

1 Scroll compressor 15 Fixed scroll 16 Swirling scroll 15A, 16A End plate 15B, 16B Spiral wrap 15C, 16C Tooth tip surface 15D, 16D Tooth bottom surface 15E Wrap side step portion (wall body side step portion)
16E End plate side step 17 Compression chamber 17A Ventral compression chamber 17B Dorsal compression chamber 30A, 30B Bypass port (extraction port)

Claims (2)

A fixed scroll with a spiral wall erected on one side of the end plate,
A swivel scroll that has a spiral wall body erected on one side of the end plate and is supported so that it can revolve and swivel while being prevented from rotating by engaging the wall bodies with each other.
A discharge port that discharges the fluid compressed by both scrolls, and
With
The end plate of either one of the scrolls has an end plate side step portion formed on one side surface so that the height is high on the central portion side and low on the outer terminal side along the vortex of the wall body. Provided,
The other wall of both scrolls is provided with a wall-side step that corresponds to the end plate-side step and is formed so that the height is low on the center side of the vortex and high on the outer end side.
After the suction deadline is performed to form a pair of compression chambers, the volume change ratios of the pair of compression chambers are configured to be different from each other due to the end plate step portion in the middle of the turning motion, so that at the time of discharge. In a scroll compressor configured such that the pressures in the pair of compression chambers are different from each other at the turning angle of
A scroll compressor, wherein the compression chamber having a higher compression chamber pressure among the pair of compression chambers communicates with the discharge port before the compression chamber having a lower pressure. A fixed scroll with a spiral wall erected on one side of the end plate,
A swivel scroll that has a spiral wall body erected on one side of the end plate and is supported so that it can revolve and swivel while being prevented from rotating by engaging the wall bodies with each other.
A discharge port that discharges the fluid compressed by both scrolls, and
With
The end plate of either one of the scrolls has an end plate side step portion formed on one side surface so that the height is high on the central portion side and low on the outer terminal side along the vortex of the wall body. Provided,
The other wall of both scrolls is provided with a wall-side step that corresponds to the end plate-side step and is formed so that the height is low on the center side of the vortex and high on the outer end side.
After the suction deadline is performed to form a pair of compression chambers, the volume change ratios of the pair of compression chambers are configured to be different from each other due to the end plate step portion in the middle of the turning motion, so that at the time of discharge. In a scroll compressor configured such that the pressures in the pair of compression chambers are different from each other at the turning angle of
When the swivel scroll is provided with a step portion on the end plate side and the fixed scroll is provided with the step portion on the wall body side, the pair of compression chambers facing each other with the center of the fixed scroll in between are described. The compression chamber on the inner peripheral side of the fixed scroll wall is communicated with the discharge port before the compression chamber on the outer peripheral side, or
When the fixed scroll is provided with the step portion on the end plate side and the swivel scroll is provided with the step portion on the wall body side, the said one of the pair of compression chambers facing each other across the center of the fixed scroll. A scroll compressor characterized in that the compression chamber on the outer peripheral side of the fixed scroll wall is communicated with the discharge port before the compression chamber on the inner peripheral side.

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