JP2001173584A - Scroll compressor - Google Patents

Abstract

(57) [Summary] [Problem] In a scroll compressor used in an air conditioner for business use and home use, performance may be deteriorated due to over-compression. SOLUTION: By providing an offset portion 36 on a wrap outer wall 31a near the beginning of winding of a wrap 31 of a movable scroll to make the wrap 31 thin, a contact between the wrap 31 between a compression chamber and a discharge chamber and a wrap of a fixed scroll is provided. A minute gap is provided at the point. For this reason, when the volume of the compression chamber is reduced and the pressure in the compression chamber exceeds the pressure on the high pressure side of the refrigeration cycle and overcompression occurs, the refrigerant gas flows from the compression chamber to the discharge chamber through the minute gap, so that the compression is performed. An increase in the pressure of the chamber can be suppressed. Therefore, it is possible to prevent a decrease in performance due to overcompression, and to provide a highly efficient scroll compressor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor used for a commercial or household air conditioner.

[0002]

2. Description of the Related Art Scroll-type compressors have been put to practical use in air conditioners for business use or home use, taking advantage of the characteristics of low noise and low vibration. Here, the conventional scroll compressor,
An example of a hermetic scroll compressor incorporating a motor will be described with reference to FIGS.

FIG. 13 is a longitudinal sectional view of a conventional scroll compressor. A fixed scroll 2 and a movable scroll 3, a thrust bearing 4 supporting the movable scroll 3, a bearing component 5, an Oldham ring 6 provided between the movable scroll 3 and the bearing component 5, and a rotating shaft L <b> 1 are provided inside the closed container 1. A compression mechanism including a crankshaft 7 that rotates at the center, and an electric motor 8 are provided.

The eccentricity r is provided at the end of the crankshaft 7.
The shaft 3a of the movable scroll 3 is inserted in the eccentric bearing 9 configured to maintain the movable scroll 3 and the movable scroll 3 is restrained from rotating by the Oldham ring 6. Therefore, the movable scroll 3 orbits with the rotation of the crankshaft 7.

[0005] A rotor 8a of an electric motor 8 is attached to the crankshaft 7, and a stator 8b is shrink-fitted in the closed casing 1. Electrodes (not shown) are provided on the side surface of the sealed container 1 and are connected to the stator 8 b to supply electric power to the electric motor 8. The crankshaft 7 is supported by a main bearing 10 provided on the bearing component 5 and a sub-bearing 11 provided below the closed casing 1. The bearing component 5 is fastened to the fixed scroll 2 with bolts.
Are hermetically welded and fixed to the closed container 1.

[0006] A suction pipe 12 for guiding the refrigerant gas to the compression mechanism is provided on the side of the closed vessel 1. Further, a discharge pipe 13 for sending the refrigerant gas to the refrigeration cycle side is provided above the closed container 1.

A discharge hole 14 is provided at the center of the fixed scroll 2. Above the discharge hole 14, a valve 15 for preventing the movable scroll 3 from rotating backward when stopped, and a valve stop for restricting the movement thereof 16 are provided.

An oil sump 17 for storing lubricating oil is provided below the closed casing 1. Lubricating oil is sucked up from an oil guide 18 at a lower end of the crankshaft 7, and a through hole 19 formed in the crankshaft 7 is provided. Through which the lubricating oil is supplied to each bearing.

Next, the operation of the compression mechanism having the above configuration will be described. Refrigerant gas from the low pressure side of the refrigeration cycle is drawn into the compression mechanism through the suction pipe 12. The orbiting movement of the orbiting scroll 3 with respect to the fixed scroll 2 compresses the refrigerant gas into a high-pressure refrigerant gas, which is discharged into the closed container 1 through the discharge holes 14. afterwards,
It is sent from the discharge pipe 13 to the high pressure side of the refrigeration cycle.

The principle of compression in the compression mechanism will be described with reference to FIGS. FIG. 14 is a cross-sectional view of the compression mechanism, FIG.
5 is an enlarged cross-sectional view near the center of the compression mechanism. The wrap 20a of the fixed scroll 2 is formed by involute curves 22a and 23a of a base circle 21a having a radius rb centered on the origin Oa of the coordinate axes X0-Y0, and the outer involute curve 22a has a spread angle of the X0 axis. Based on the positive direction, the inner involute curve 23a is shifted by a phase angle θ (= w / rb) corresponding to the wrap thickness w.

The wrap 20b of the orbiting scroll 3 has a similar shape, and has an involute curve 22 of a base circle 21b centered on the origin Ob of the coordinate axes X1-Y1 and having a radius rb.
b, 23b. These curves translate the wrap 20a of the fixed scroll 2 on a revolving circle 24 having a radius ra (= π × rb-w) centered on the origin Oa of the coordinate axes X0-Y0, and rotated by 180 degrees. Equivalent to something.

As shown in FIG. 14, the wraps 20a and 20b of the fixed and movable scrolls 2 and 3 are P1 and P2.
The suction chambers 25a and 25b, the compression chambers 26a and 26b, and the discharge chamber 27 are formed by contacting and meshing with the points Q1 and Q2 at a plurality of points. When the orbiting scroll 3 makes a clockwise orbital movement on the orbiting circle 24 having the orbital radius ra from this state, the contact points P1, P2, Q1, and Q2 approach the coordinate axis origin, and the volumes of the compression chambers 26a and 26b decrease. . Due to this swirling motion, the compression chambers 26a and 26b gradually decrease in volume while approaching the origin of the coordinate axes.
The internal refrigerant gas is compressed.

[0013] The suction chamber is in a state where it is not substantially sealed by the fixed scroll and the movable scroll.
The space between the fixed scroll and the movable scroll,
The compression chamber refers to a space between the fixed scroll and the movable scroll which is substantially sealed by the fixed scroll and the movable scroll. Therefore, as shown in FIG. 14, the wraps 20a, 2 of the fixed and movable scrolls 2, 3 are formed.
When 0b contacts and meshes with the P1 and P2 points and the Q1 and Q2 points at a plurality of points, the suction chamber means the space of 25a and 25b, and the compression chamber means the space of 26a and 26b.

FIG. 16 shows changes in the volumes of the suction chambers 25a and 25b and the compression chambers 26a and 26b,
The change of the gap t between the openings 28a and 28b of FIG. 5b is shown. The volumes and gaps on the vertical axis are shown with their maximum values being 100%. The turning angle of the horizontal axis is the turning angle of the movable scroll 3 based on the start of the suction stroke. As can be seen from FIG. 16, the volumes of the suction chambers 25a and 25b reach a maximum value during the suction stroke, and part of the refrigerant gas once sucked into the suction chambers 25a and 25b is discharged from the openings 28a and 28b.

[0015]

In the above-described conventional scroll type compressor, a specific compression ratio is determined by the number of turns of an involute curve constituting a wrap of a fixed scroll and a movable scroll. However, in a refrigeration cycle used in an air conditioner, the pressure on the high-pressure side and the low-pressure side change due to changes in the amount of heat exchange in the heat exchanger and changes in the operating frequency of the compressor using the inverter. The required compression ratio is not constant.

For this reason, when the pressure ratio between the high pressure side and the low pressure side of the refrigeration cycle is smaller than the compression ratio inherent in the scroll compressor, the refrigerant gas on the low pressure side of the refrigeration cycle sucked by the scroll compressor is temporarily refrigerated. Compressed to a higher pressure than the high pressure side of the cycle and sent out,
The amount of work increased, resulting in a decrease in performance.

The present invention has been made in consideration of the above-described problems of the conventional scroll compressor, and has as its object to provide a high-efficiency scroll compressor in which the amount of work does not increase even if the compression ratio changes. It is.

Further, in the conventional scroll compressor, a part of energy is wasted by the refrigerant gas discharged once after being sucked into the suction chamber in the suction process, and the efficiency is lowered.

The present invention has been made in consideration of the above-described problems of the conventional scroll compressor, and provides a high-efficiency scroll compressor by reducing the amount of refrigerant gas discharged once after being sucked into a suction chamber. It is intended for.

[0020]

Means for Solving the Problems The first invention (claim 1)
Corresponds to a crankshaft that can rotate around the rotation axis,
A bearing that supports the crankshaft, a fixed scroll,
A movable scroll that is eccentrically attached to the crankshaft by a predetermined amount so as to orbit with respect to the rotating shaft, and that meshes with the fixed scroll; a thrust bearing that supports the movable scroll; The fixed scroll and the movable scroll each have a spiral-shaped wrap, and a compression mechanism portion having an Oldham coupling that restrains the rotation motion has a spiral wrap, and at least one of the fixed scroll and the movable scroll has a wrap start. A scroll compressor characterized in that a predetermined region is offset in a thickness direction.

For example, the wrap is an involute curve-shaped wrap, and at least a part of a section having an expansion angle of 0 to 2πrad on the outer wall near the start of winding of the wrap of at least one of the fixed scroll and the movable scroll. , Or the extension angle π to 3πrad at the inner wall
At least a portion of the section is offset in the thickness direction to reduce the thickness of the wrap in this portion,
By providing a minute gap at the contact point separating the compression chamber and the discharge chamber, the compression ratio can be made variable and the compression efficiency can be increased.

According to a second aspect of the present invention, a crankshaft rotatable around a rotating shaft, a bearing supporting the crankshaft, a fixed scroll, and a revolving motion with respect to the rotating shaft are provided. A movable scroll attached to the crankshaft eccentrically by a predetermined amount, a thrust bearing for supporting the movable scroll, and a compression mechanism having an Oldham coupling for restraining the rotation of the movable scroll, The fixed scroll and the movable scroll each have a spiral wrap, and at least one of the wraps of the fixed scroll and the movable scroll has one wrap at the end position of the wrap. The other lap wall, which has one flat portion and faces the first flat portion, may face the first flat portion for a predetermined length. A scroll compressor and having a second flat section that can.

With this configuration, in the final stage of the suction stroke, the opening of the suction chamber becomes a narrow flow path sandwiched between the inner wall flat portion and the outer wall flat portion. The amount of refrigerant gas discharged after being sucked is
It can be reduced by the wall frictional resistance of the flow channel.
In other words, more refrigerant gas can be taken into the suction chamber at the end of the suction stroke. Therefore, a supercharging effect can be obtained without increasing the power, and a highly efficient scroll compressor can be provided.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The configuration of the scroll compressor according to the embodiment of the present invention is shown in FIGS. 13 to 15 except for a part of the wrap of the fixed scroll and the wrap of the movable scroll.
In the embodiment of the present invention, the same parts as those described in the above-described conventional example will not be described.

(Embodiment 1) FIG. 1 is an enlarged cross-sectional view showing the vicinity of the start of winding of a wrap of a movable scroll according to Embodiment 1, and FIG. 2 is an overall cross-sectional view of the wrap. 3 and 4 are cross-sectional views of the compression mechanism.

In FIG. 1, W is the start of winding of the involute curve C1 constituting the outer wall of the wrap 31, and the spread angle is zero. Hereinafter, the extension angle of the involute including the involute curve C2 constituting the inner wall of the wrap 31 is based on this position.

The involute curve shape of the wrap outer wall 31a starts from P at the expansion angle θ1 and ends at R at the expansion angle θ2. θ2 is expressed by (Equation 1) using the polytropic index κ and the maximum compression ratio λ1 among the assumed operating conditions of the scroll compressor.

[0028]

(Equation 1) With such a configuration, the wrap 31 has the number of turns that gives the compression ratio λ1.

Further, the expansion angle θ3 of Q is represented by (Equation 2) using the polytropic index κ and the minimum compression ratio λ2 under the assumed operating conditions of the compressor.

[0030]

(Equation 2) The wrap outer wall 31a in the section from P to Q is offset toward the inner wall 31b from the involute curve C1 by a constant offset d in the wrap thickness direction. The size of the distance d is about 0.1 mm.

The same applies to the shape of the wrap of the fixed scroll.

With this configuration, the compression chambers 32a, 3a
2b is completely closed by the contact points 33a, 33b, 34a, and 34b before and after the compression ratio reaches λ2. However, after the compression ratio reaches λ2 or more, the wrap 31 swings. A contact point 33a on the discharge chamber 35 side,
33b is located at the offset portion 36 of the wrap outer wall 31a, and the compression chambers 32a and 32b communicate with the discharge chamber 35 via a gap of a distance d.

When the scroll compressor is operated under the condition that the load of the refrigeration cycle is light, the compression ratio and the rotation speed are low, in the conventional scroll compressor, the volume of the compression chamber is reduced and the pressure in the compression chamber is reduced. Although excessive compression occurred due to exceeding the pressure on the high pressure side of the above, in the present embodiment,
As shown by the arrow in FIG. 4, when over-compression occurs, refrigerant gas flows from the compression chambers 32a and 32b to the discharge chamber 35 through the gap of the offset portion 36, so that the compression chambers 32a and 3b
2b can be suppressed from increasing. Therefore, it is possible to prevent performance degradation due to overcompression.

When the scroll compressor is operated under the condition that the load of the refrigeration cycle is heavy, the compression ratio and the rotation speed are high, as shown by the arrow in FIG. The refrigerant gas flows backward from the chamber 35 to the compression chambers 32a and 32b. However, since the rotation speed of the scroll compressor is high, the amount of the refrigerant gas sent out of the scroll compressor is large, but the flow rate of the backflow is very small and negligible. Therefore, it has little effect on performance.

As can be understood from these facts, the scroll compressor of the present embodiment exhibits high performance under any operating conditions.

The offset d of the offset section 36
Is set to 0.1 mm, but it is not always necessary to set this value within a range up to about 0.5 mm. By increasing the offset amount d, it is possible to further enhance the effect of preventing over-compression when operating under conditions of a low compression ratio and a low rotational speed. Further, by further reducing the offset amount d, it is possible to further reduce the influence on the performance due to the backflow from the discharge chamber 35 to the compression chambers 32a and 32b when operating under the conditions of a high compression ratio and a high rotation speed. It is possible. Therefore, a scroll compressor with higher performance can be obtained by selecting the offset amount d at which the synergistic effect of both of them is maximized.

The offset section 36 does not necessarily have to be provided in the entire range from P to Q.
To Q, the above-described effect of preventing over-compression can be obtained.

The above is also true when the offset portion is provided only on the outer wall 31a of the orbiting scroll. That is, the wrap outer wall 31a of the movable scroll
Is prevented from being overcompressed in the compression chamber 32a at the position in contact with the scroll compressor, so that the performance of the scroll compressor can be improved. The fixed scroll wrap outer wall 37 is also provided.
It is needless to say that the same effect can be obtained even when the above-mentioned offset portion (not shown) is provided only in a. In short, it is only necessary to offset at least one of the wrap outer walls of the movable scroll and the fixed scroll.

In the above-described embodiment, the offset amount d of the offset portion 36 is from 0.1 mm to 0.5 mm.
Although it was sufficient if it was in the range up to the extent, by increasing the height of the compression mechanism if the substantial diameter of the compression mechanism is large, and by decreasing the height of the compression mechanism if the diameter is small, The offset amount d is from 0.1 mm to 0.5 mm
If it is within the range, the offset portion 36 may be
Since the refrigerant gas flows from the compression chambers 32a and 32b to the discharge chamber 35 through the gap, the effect of suppressing an increase in the pressure of the compression chambers 32a and 32b can be exhibited.

(Embodiment 2) FIG. 5 is an enlarged cross-sectional view of the vicinity of the start of winding of a wrap of a movable scroll according to Embodiment 2. The same applies to the shape of the wrap of the fixed scroll. Further, the configuration of the scroll compressor of the present embodiment is the same as that of the first embodiment in FIG. 1 except for the shape of the offset portion 38 of the wrap outer wall 31a. Therefore,
In the present embodiment, description of the same parts as those in the first embodiment will be omitted.

In the present embodiment, the wrap outer wall 31a in the section from P to Q is tapered from the involute curve C1 to the wrap inner wall 31b.
The offset amount is set to d at P, and is decreased by a linear function as the extension angle increases, and set to zero at Q.
The offset d at P is set to about 0.1 mm.

The same applies to the shape of the wrap of the fixed scroll.

With such a configuration, the compression chambers 32a, 3
2b is completely closed by the contact points 33a, 33b, 34a, and 34b before and after the compression ratio reaches λ2, but after the compression ratio reaches λ2 or more, the contact on the discharge chamber 35 side Points 33a, 33b are located at the tapered offset portion 38 of the wrap outer wall 31a, and the compression chamber 32
a and 32b communicate with the discharge chamber 35 through a gap of a distance d.

When the scroll compressor is operated under the condition that the load of the refrigeration cycle is light, the compression ratio and the rotation speed are low, the gap is small when the overcompression is small by changing the offset amount, and When the volume of 32a, 32b is further reduced and overcompression is increased, the gap is increased. Accordingly, the compression chambers 32a and 32b
Can efficiently increase the flow rate of the refrigerant gas flowing through the compression chambers in proportion to the magnitude of the overcompression, so that an increase in the pressure of the compression chambers 32a and 32b can be suppressed, and a decrease in performance due to overcompression can be prevented.

When the compressor is operated under the condition that the load of the refrigeration cycle is heavy, the compression ratio and the rotation speed are high, the discharge chamber 35 is moved from the discharge chamber 35 to the compression chambers 32a and 32b through the gap of the tapered offset portion 38. Although the refrigerant gas flows backward, the gap of the tapered offset portion 38 is smaller as the pressure is lower, and gradually increases until the discharge pressure is reached. Therefore, the backflow of the refrigerant gas is further reduced as compared with the first embodiment. can do. Therefore, the performance can be further improved.

In the second embodiment described above, the offset amount on the wrap inner wall 31b side is reduced by a linear function as the extension angle increases, but the offset amount decreases as the extension angle increases. It is only necessary to perform the reduction, and there is no limitation that the reduction is performed by a linear function.

The offset d at P is 0.1 m
It is not limited to about m.

In the above-described embodiment, the movable scroll and the fixed scroll have the same shape. However, only the outer wall of one of the movable scroll and the fixed scroll may be offset.

(Embodiment 3) FIG. 6 is an enlarged cross-sectional view showing the vicinity of the start of winding of a wrap of a movable scroll according to Embodiment 3 of the present invention. The configuration of the scroll compressor of the present embodiment is different from that of the wrap outer wall 31a in that the wrap inner wall 31b is not used.
Is the same as that of the first embodiment except that is offset. Therefore, in the present embodiment, the first embodiment
The description of the same parts as described above is omitted.

The involute curve C2 forming the inner wall 31b of the wrap starts at P 'at the expansion angle θ4 and ends at R' at θ5. θ4 is given by the following equation (Equation 3), and θ5 is given by the following equation (Equation 4).

[0051]

(Equation 3)

[0052]

(Equation 4) However, the extension angle of P 'is not necessarily set to θ4, and may be set to θ4 or less so as not to interfere with the outer wall 31a of the other scroll when the compression mechanism is assembled.

Further, the expansion angle θ6 of Q ′ is expressed by the following (Equation 5) using the minimum compression ratio λ2 and the polytropic index κ under the assumed operating conditions of the compressor. Then, the wrap inner wall 31b in the section from P 'to Q' is shifted from the involute curve C2 by the offset amount d by the offset amount d.
Offset to a side. The magnitude of the offset amount d is about 0.1 mm.

[0054]

(Equation 5) The same applies to the shape of the wrap of the fixed scroll.

With such a configuration, the compression chambers 32a, 3
2b is completely closed by the contact points 33a, 33b, 34a, and 34b before and after the compression ratio reaches λ2, but after the compression ratio reaches λ2 or more, the contact on the discharge chamber 35 side The points 33a and 33b are located at the offset portions 39 of the wrap inner wall 31b, and the compression chambers 32a and 32b communicate with the discharge chamber 35 via a gap of a distance d.

The effect obtained in this embodiment is the same as that of the first embodiment, and the load of the refrigeration cycle is light,
An object of the present invention is to provide a highly efficient scroll compressor that prevents performance degradation due to overcompression that occurs when operating under conditions of a low compression ratio and a low rotational speed.

In the wrap 31 of the movable scroll, the offset portion 3 of the present embodiment is provided on the wrap inner wall 31b.
9 is provided on the wrap outer wall 31a with the offset portion 36 shown in the first embodiment, so that both the movable scroll and the fixed scroll have the wrap inner walls 31b and 37b provided with the offset portion of the present embodiment. The effect can be obtained. The same can be said for the fixed scroll wrap 37.

The offset d is not limited to about 0.1 mm.

In the above-described embodiment, the shapes of the movable scroll and the fixed scroll are the same, but only the inner wall of one of the movable scroll and the fixed scroll may be offset.

(Embodiment 4) FIG. 7 is an enlarged cross-sectional view of the orbiting scroll of the movable scroll according to Embodiment 4 of the present invention in the vicinity of the winding start. The same applies to the shape of the wrap of the fixed scroll. Further, the configuration of the scroll compressor according to the present embodiment has the offset d of the wrap inner wall 31b.
The third embodiment is the same as the third embodiment shown in FIG. Therefore, in the present embodiment, the description of the same parts as in the third embodiment will be omitted.

In the present embodiment, the wrap inner wall 31b in the section from P 'to Q' is tapered and offset from the involute curve C2 toward the wrap inner wall 31b. The offset amount is set to d at P ′, and is decreased by a linear function as the extension angle increases, and set to zero at Q ′. The offset d at P 'is set to about 0.1 mm. However, the offset d at P ′ is not limited to about 0.1 mm. Further, the offset amount on the wrap inner wall 31b side only needs to be reduced with an increase in the extension angle, and is not limited to be reduced by a linear function.

The same applies to the shape of the wrap of the fixed scroll.

The effect obtained in this embodiment is the same as that of the third embodiment, and the load of the refrigeration cycle is light,
It is an object of the present invention to provide a highly efficient scroll compressor that prevents performance deterioration due to overcompression when the compressor is operated under conditions of a low compression ratio and a low rotation speed.

In the above-described embodiment, the movable scroll and the fixed scroll have the same shape. However, only the inner wall of one of the movable scroll and the fixed scroll may be offset.

In Embodiments 1 to 4 described above, the spiral shape of the wrap is an involute curve, but it goes without saying that the same effect can be obtained even when an Archimedes curve or the like is used. In short, it suffices that at least one of the wraps of the fixed scroll and the movable scroll is provided with an offset in the thickness direction in the vicinity of the winding start. The offset may be applied to the inside or outside of the wrap. Further, the amount of the offset may be substantially constant irrespective of the winding angle of the wrap, or may decrease as the winding angle increases.

(Fifth Embodiment) FIG. 8 is a cross-sectional view of a compression mechanism according to a fifth embodiment. Inner wall 131a and outer wall 132a of spiral wrap 130a of fixed scroll 2
Is a base circle 1 centered on the origin Oa of the coordinate axes X0-Y0.
33a is formed by the involute curve. Also,
The inner wall 131b and the outer wall 132b of the spiral wrap 130b of the movable scroll 3 are connected to the origin O of the coordinate axes X1-Y1.
It is formed by an involute curve of a base circle 133b centered at b.

From the point S1 at the winding end position of the involute curve of the inner wall 131a of the fixed scroll 2, the point S1
An inner wall flat portion 134a having a length L is provided in a tangential direction of the involute curve at the point. The point T1 on the involute curve of the outer wall 132b of the movable scroll 3 is
This point is in contact with the point S1 in accordance with the turning movement of the orbiting scroll 3, and from the point T1, in the tangential direction of the involute curve at the point T1, the outer wall flat portion 135 having a length L is formed.
a is provided.

From the point S2 at the end of winding of the involute curve of the inner wall 131b of the movable scroll 3, the point S2
In the tangent direction of the involute curve at the point, the length L '
The inner wall flat portion 134b is provided. The point T2 on the involute curve of the outer wall 132a of the fixed scroll 2 is a point at which the movable scroll 3 makes opposing contact with the point S2 along with the orbital movement of the orbiting scroll 3. From the point T2, the tangential direction of the involute curve at the point T2 An outer wall flat portion 135b having a length L 'is provided.

The wraps 130a and 130b of the fixed scroll 2 and the movable scroll 3 come into contact with and mesh with each other at a plurality of points P1, P2, Q1 and Q2, thereby forming the suction chamber 136.
a, 136b, compression chambers 137a, 137b, discharge chamber 13
8. When the orbiting scroll 3 orbits, the contact points P1, P2, Q1, and Q2 respectively approach the coordinate axis origins, and accordingly, the suction chambers 136a, 136b,
The volumes of the compression chambers 137a and 137b and the discharge chamber 138 change.

The suction chambers 136a and 136b and the compression chamber 1
37a, 137b and the suction chambers 136a, 136b.
The change in the gap t between the openings 139a and 139b of 36b is
This is the same as the conventional scroll compressor shown in FIG.
Hereinafter, the suction chambers 136a and 136b and the compression chamber 137
a, 137b and the suction chambers 136a, 136
FIG. 16 shows changes in the gap t between the openings 139a and 139b of FIG.
This will be described with reference to FIG.

The volumes of the suction chambers 136a and 136b increase in the range of the turning angle from 0 deg to 315 deg and reach a maximum value, and then the turning angle increases from 315 deg to 360 deg.
g. The gap t between the openings 139a and 139b of the suction chambers 136a and 136b has a turning angle of 0 deg.
From 180 deg to the maximum value,
The turning angle decreases in the range from 180 deg to 360 deg. Openings 139a, 139 at a turning angle of 360 deg
When the gap t of b becomes zero and the suction stroke is completed, the suction chambers 136a and 136b become the compression chambers 137a and 137b, and the compression stroke is started. After the start of the compression stroke, the compression chamber 137
Since the volumes of a and 137b decrease monotonically, the refrigerant gas inside is compressed.

In the suction stroke, the suction chambers 136a, 136
The range in which the volume of 6b increases, that is, the turning angle is 0 de
g to 315 deg, the openings 139a, 139
The refrigerant is sucked into the suction chambers 136a and 136b through 9b. On the other hand, the range in which the volumes of the suction chambers 136a and 136b are reduced, that is, the turning angle is from 315 deg to 3
In the range of 60 deg, the refrigerant gas once sucked from the suction chambers 136a and 136b through the openings 139a and 139b is discharged.

In this embodiment, as described above, the fixed scroll 2 is provided with the inner wall flat portion 134a having the length L, and the movable scroll 3 is provided with the outer wall flat portion 135a having the length L, so that the opening of the suction chamber 136a is formed. 139a is a flow path having a gap t and a length L. The movable scroll 3 has a length L '.
Of the inner wall flat portion 134b and the fixed scroll 2 having the outer wall flat portion 135b having the length L '.
The opening 139b of b is a flow path having a gap t and a length L '.

As can be seen from FIG. 16, the turning angle is 31
The gap t in the range of 5 deg to 360 deg is 17% or less of the maximum value at the turning angle of 180 deg, and is very narrow. Therefore, a large wall frictional resistance acts on the refrigerant gas discharged through the openings 139a and 139b, and the amount of the refrigerant gas once drawn into the suction chambers 136a and 136b is reduced through the openings 139a and 139b. Can be.

In other words, the turning angle 36 at the end of inhalation
At 0 deg, more refrigerant gas is supplied to the suction chamber 136.
a, 136b. Therefore, a supercharging effect can be obtained in the suction chambers 136a and 136b without increasing power as compared with the conventional scroll compressor, and a highly efficient scroll compressor can be provided.

The magnitude of the supercharging effect in the suction chamber 139a depends on the inner wall flat portion 134a and the outer wall flat portion 135.
It can be adjusted by the length L of a. If L is made longer, the wall frictional resistance acting on the refrigerant gas discharged through the opening 139a increases, and a greater supercharging effect can be obtained. Similarly, the magnitude of the supercharging effect in the suction chamber 139b depends on the inner wall flat portion 134b and the outer wall flat portion 13b.
It can be adjusted by the length L 'of 5b.

(Embodiment 6) FIG. 9 is a cross-sectional view of a compression mechanism according to Embodiment 6. The inner wall 51a and the outer wall 52a of the spiral wrap 50a of the fixed scroll 2 are formed by an involute curve of a base circle 53a centered on the origin Oa of the coordinate axes X0-Y0. Further, the inner wall 51b and the outer wall 52b of the spiral wrap 50b of the orbiting scroll 3 are formed by an involute curve of a base circle 53b centered on the origin Ob of the coordinate axes X1-Y1.

The inner wall 5 of the wrap 50a of the fixed scroll 2
The winding angle of the involute curve of 1a is 1 point in the longitudinal direction of the wrap 50a from the point A which is equal to the winding angle of the involute curve of the inner wall 51b of the wrap 50b of the movable scroll 3.
It has been extended to point S3, 80 deg.

[0086] An inner wall flat portion 54a having a length L is provided in the tangential direction of the involute curve at the point S3 ahead of the point S3 at the end of winding of the involute curve of the inner wall 51a of the fixed scroll 2. The point T3 on the involute curve of the outer wall 52b of the orbiting scroll 3 is a point that comes into contact with the point S3 as the orbiting motion of the orbiting scroll 3 proceeds. From the point T3, the tangential direction of the involute curve at the point T3 becomes longer. An outer wall flat portion 55a having a height L is provided.

Further, before the winding end position of the involute curve of the inner wall 51b of the orbiting scroll 3 from the point S4,
In the tangential direction of the involute curve at the point S4, an inner wall flat portion 54b having a length L is provided. The T4 point on the involute curve of the outer wall 52a of the fixed scroll 2 is
This is a point that comes into contact with the point S4 in accordance with the orbital movement of the orbiting scroll 3, and an outer wall flat portion 55b having a length L is provided ahead of the point T4 in a tangential direction of the involute curve at the point T4.

FIG. 10 is an enlarged view of the inner wall flat portion 54a, the outer wall flat portion 55a, the inner wall flat portion 54b, and the outer wall flat portion 55b.

The wraps 50a and 50b of the fixed scroll 2 and the movable scroll 3 come into contact with and mesh with each other at a plurality of points P1, P2, Q1 and Q2, thereby forming the suction chambers 56a and 56b.
b, compression chambers 57a and 57b, and a discharge chamber 58.

In the present embodiment, the fixed scroll 2 and the movable scroll 3 are respectively provided with inner wall flat portions 54a of length L,
With the provision of the outer wall flat portions 55a and 55b and the outer wall flat portions 55a and 55b, the openings 59a and 59b of the suction chambers 56a and 56b become a flow passage having gaps t and t '(= ra-t) and a length L.
As can be seen from FIG. 16, the gaps t and t ′ in the range of the turning angle from 315 deg to 360 deg are equal to the turning angle 18
It is 17% or less of the maximum value at 0 deg, which is very narrow.

For this reason, a large wall frictional resistance acts on the refrigerant gas discharged through the openings 59a and 59b, and the amount of the refrigerant gas once drawn into the suction chambers 56a and 56b is discharged through the openings 59a and 59b. Can be reduced. In other words, the turning angle 360d at the end of inhalation
In the eg, more refrigerant gas is supplied to the suction chambers 56a, 5a.
6b. Therefore, the suction chamber 56 is increased without increasing the power as compared with the conventional scroll compressor.
A supercharging effect can be obtained at a and b, and a highly efficient scroll compressor can be provided.

In this embodiment, the winding angle of the involute curve of the inner wall 51a of the wrap 50a of the fixed scroll 2 is determined by the inner wall 51 of the wrap 50b of the movable scroll 3.
By extending from point A equal to the winding angle of the involute curve b to point S3 180 degrees ahead in the longitudinal direction of the wrap 50a, the S3 point of the inner wall 51a of the wrap 50a of the fixed scroll 2 and the T4 point of the outer wall 52b are: Both are located on the moving radius 60a of the base circle 53a,
The inner wall flat portion 54a and the outer wall flat portion 55b are substantially parallel to each other. Therefore, the shape of the wrap 50a of the fixed scroll 2 is simple and compact, and processing is easy.

The S4 point of the inner wall 51b of the wrap 50b of the movable scroll 3 and the T3 point of the outer wall 52b are both located on the moving radius 60b of the base circle 53b.
The inner wall flat portion 54b and the outer wall flat portion 55a are substantially parallel to each other, and the flat portions 54b and 55a can be provided while the wrap 50b of the movable scroll 3 is maintained at a constant thickness. Therefore, the shape is simple and compact, and processing is easy.

(Seventh Embodiment) FIG. 11 shows a wrap 50 of a fixed scroll 2 and a movable scroll 3 according to a seventh embodiment.
a, 50b is an enlarged cross-sectional view near the end of winding. The configuration of the present embodiment is substantially the same as the configuration of the sixth embodiment described with reference to FIG. 9 except for a part, and the same reference numerals are given to the same portions as the configuration of the sixth embodiment. The description is omitted.

In the present embodiment, rectangular grooves 61a and 61b are provided in the inner wall flat portion 54a of the fixed scroll 2, and rectangular grooves 62a and 62b are provided in the outer wall flat portion 55b. In addition, the inner scroll flat surface portion 54b and the outer wall flat surface portion 55a of the orbiting scroll 3 are provided with displacement surfaces 63a and 63b that are displaced in a direction in which the thickness of the wrap becomes thinner.

The rectangular grooves 61a, 61b, 62a, and 6 are formed in the inner wall flat portion 54a and the outer wall flat portion 55b of the fixed scroll 2.
With the provision of 2b, the refrigerant gas discharged through the openings 59a and 59b of the suction chambers 56a and 56b undergoes pressure loss due to expansion and contraction of the flow path cross-sectional area in addition to the wall frictional resistance. , 56b can further increase the effect of reducing the amount of refrigerant gas once sucked into suction. Therefore, the suction chambers 56a, 56b on both sides
In this case, a larger supercharging effect can be obtained than in Embodiment 6, and a highly efficient scroll compressor can be provided.

The grooves 61a, 61b, 62a, 62b
Need not be limited to a rectangle, and the number is not specified. The magnitude of the supercharging effect is determined by the grooves 61a, 61b, 62
It can be adjusted by a combination of the shapes, sizes, and numbers of a and 62b.

The grooves 61a and 61b do not necessarily need to be provided on the inner wall flat portion 54a of the fixed scroll 2, and needless to say, the same effects can be obtained by providing them on the outer wall flat portion 55a of the movable scroll 3.

The grooves 62a and 62b need not necessarily be provided on the outer wall flat portion 55b of the fixed scroll 2, and it goes without saying that the same effect can be obtained by providing them on the inner wall flat portion 54b of the movable scroll 3.

Further, the inner wall flat portion 5 of the movable scroll 3
4b, the outer surface 52a of the fixed scroll 2 accompanies the orbital movement of the movable scroll 3.
When the T4 point and the S4 point of the inner wall 51b of the movable scroll 3 are in contact with each other, the outer wall flat portion 55b of the fixed scroll 2 and the inner wall flat portion 54 of the movable scroll 3
Since a minute gap is secured between the displacement surfaces 63a of b, no contact occurs.

Similarly, the outer wall flat portion 5 of the movable scroll 3
5a is provided with a displacement surface 63b, so that the orbiting motion of the movable scroll 3 causes the inner wall 51a of the fixed scroll 2 to move.
And the point S3 of the movable scroll 3 and the point T3 of the outer wall 52b of the movable scroll 3 are in contact with each other, the inner wall flat part 54a of the fixed scroll 2 and the outer wall flat part 55 of the movable scroll 3
Since a minute gap is secured between the displacement surfaces 63b of a, no contact occurs.

The inner wall flat portion 54a of the fixed scroll 2 and the outer wall flat portion 55a of the movable scroll 3, the movable scroll 3
Inner wall flat portion 54b and fixed scroll 2 outer wall flat portion 5
5b are in contact with each other, the contact P of the spiral part
1, the wraps 50a, 50b exert a greater force on each other as compared to the line contact at 1, P2, Q1, Q2. Therefore, in order to ensure the reliability of the wraps 50a and 50b, measures such as reinforcement of the wraps 50a and 50b are required.

On the other hand, in the present embodiment, the inner wall flat portion 54a of the fixed scroll 2, the outer wall flat portion 55a of the movable scroll 3, and the inner wall flat portion 54b of the movable scroll 3
And the outer wall flat portion 55b of the fixed scroll 2 do not contact with each other, so that a highly reliable scroll compressor can be provided without reinforcing the wraps 50a and 50b.

It is needless to say that the displacement surface 63a does not necessarily have to be provided on the inner wall flat portion 54b of the movable scroll 3, and it is needless to say that the same effect can be obtained even if it is provided on the outer wall flat portion 55b of the fixed scroll 2.

It is needless to say that the displacement surface 63b does not necessarily have to be provided on the outer wall flat portion 55a of the movable scroll 3, and it is needless to say that the same effect can be obtained even if it is provided on the inner wall flat portion 54a of the fixed scroll 2.

When the displacement amount of the displacement surfaces 63a, 63b is increased, the gap between the inner wall flat portions 54a, 54b and the outer wall flat portions 55a, 55b is increased, so that the contact is less likely to occur. , 56b, the width of the flow path of length L at the openings 59a, 59b is increased, and the supercharging effect is reduced. Therefore, in the present embodiment, the inner wall flat portions 54a and 54b and the outer wall flat portion 55
It is important to balance the prevention of contact and the supercharging effect at a and 55b, and the displacement is optimally 3 to 20% of the thickness of the spiral-shaped portion of the wraps 50a and 50b.

Further, the spiral shape of the wrap of the scroll compressor of the present invention has been described as using an involute curve in each of the above embodiments, but is not limited to this.

As shown in FIG. 12, an offset 36a is provided at the beginning of the wrap of the fixed scroll, and an offset 36b is provided at the beginning of the wrap of the movable scroll.
Is provided, and at the end of winding of the wrap,
A scroll compressor including a compression mechanism provided with an inner wall flat portion 134b for the movable scroll and an outer wall 135b for the fixed scroll also belongs to the present invention.

More specifically, a predetermined area at the beginning of winding of at least one of the wraps of the fixed scroll and the movable scroll is offset in the thickness direction, and the winding end position of at least one of the wraps of the fixed scroll and the movable scroll is provided. , A first flat portion is provided on one wall of one of the wraps at the winding end position, and the first flat portion is opposed to the first flat portion by a predetermined length on a wall of the other wrap facing the first flat portion. A scroll compressor having a compressor rear portion provided with a second flat portion which can be provided also belongs to the present invention.

[0103]

As apparent from the above description, the first aspect of the present invention is to provide an offset portion on the outer or inner wall of the wrap near the start of the wrap winding of the movable scroll or the fixed scroll to make the wrap thinner.
A minute gap is provided at a contact point between the wraps between the compression chamber and the discharge chamber. For this reason, when the volume of the compression chamber is reduced and the pressure in the compression chamber exceeds the pressure on the high pressure side of the refrigeration cycle and overcompression occurs, the refrigerant gas flows from the compression chamber to the discharge chamber through the minute gap, so that the compression is performed. An increase in the pressure of the chamber can be suppressed. Therefore, a decrease in performance due to overcompression can be prevented, and a highly efficient scroll compressor can be provided.

Further, according to a second aspect of the present invention, an inner wall flat portion or an outer wall flat portion is provided at a winding end position of at least one of the spiral wraps of the fixed scroll and the movable scroll, and the other of the wraps is opposed to the inner wall flat portion. By providing the outer wall flat portion or the inner wall flat portion on the wrap, in the final stage of the suction stroke, the opening of the suction chamber is formed as a narrow flow path sandwiched between the inner wall flat portion and the outer wall flat portion. It is composed.

Therefore, in the suction process, the amount of the refrigerant gas discharged once after being sucked into the suction chamber can be reduced by the action of the wall friction resistance in the flow path of the opening. In other words, more refrigerant gas can be taken into the suction chamber at the end of the suction stroke. Therefore, a supercharging effect can be obtained without increasing the power, and a highly efficient scroll compressor can be provided.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view near the beginning of winding of a wrap of a movable scroll according to a first embodiment.

FIG. 2 is a cross-sectional view of a wrap of a movable scroll according to the first embodiment.

FIG. 3 is a cross-sectional view of a compression mechanism according to the first embodiment.

FIG. 4 is a cross-sectional view of a compression mechanism according to the first embodiment.

FIG. 5 is an enlarged cross-sectional view near the beginning of winding of a wrap of a movable scroll according to a second embodiment.

FIG. 6 is an enlarged cross-sectional view showing the vicinity of the beginning of winding of a wrap of a movable scroll according to a third embodiment.

FIG. 7 is an enlarged cross-sectional view of the vicinity of the beginning of winding of a wrap of a movable scroll according to a fourth embodiment.

FIG. 8 is a cross-sectional view of a compression mechanism of a scroll compressor according to a fifth embodiment.

FIG. 9 is a cross-sectional view of a compression mechanism of a scroll compressor according to a sixth embodiment.

FIG. 10 is a cross-sectional view of a part of a compression mechanism of a scroll compressor according to a sixth embodiment.

FIG. 11 is an enlarged cross-sectional view of a compression mechanism of a scroll compressor according to a seventh embodiment.

FIG. 12 is a cross-sectional view of a compression mechanism of the scroll compressor according to the embodiment;

FIG. 13 is a longitudinal sectional view of a conventional scroll compressor.

FIG. 14 is a cross-sectional view of a compression mechanism of a conventional scroll compressor.

FIG. 15 is an enlarged cross-sectional view near the center of a compression mechanism of a conventional scroll compressor.

FIG. 16 is a diagram showing the relationship between the volume of the suction chamber of the scroll compressor, the clearance of the opening, and the turning angle of the movable scroll.

[Explanation of symbols]

31 wrap 31a wrap outer wall 31b wrap inner wall 32a, 32b compression chamber 33a, 33b, 34a, 34b contact point 35 discharge chamber 36, 38, 39, 40 offset part 20a, 20b, 130a, 130b, 50a, 50b
Wraps 131a, 131b, 51a, 51b Wrap inner walls 132a, 132b, 52a, 52b Wrap outer walls 134a, 134b, 54a, 54b Inner wall flat portions 135a, 135b, 55a, 55b Outer wall flat portions 25a, 25b, 136a, 136b, 56a, 56b
Suction chamber 26a, 26b, 137a, 137b, 57a, 57b
Compression chamber 61a, 61b, 62a, 62b Groove 63a, 63b Displacement surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fumitoshi Nishiwaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Terms (reference) 3H039 AA03 AA06 AA12 BB17 CC04 CC06 CC07

Claims (15)

[Claims] 1. A crankshaft rotatable around a rotating shaft, a bearing supporting the crankshaft, a fixed scroll, and the crankshaft eccentric by a predetermined amount so as to orbit with respect to the rotating shaft. And a compression mechanism unit having a movable scroll that meshes with the fixed scroll, a thrust bearing that supports the movable scroll, and an Oldham coupling that restricts the rotation of the movable scroll. The scroll, wherein each of the movable scrolls has a spiral-shaped wrap, and a predetermined region at the beginning of winding of at least one of the fixed scroll and the movable scroll is offset in a thickness direction. Compressor. 2. The wrap according to claim 1, wherein the offset is provided inside the wrap at the beginning of the winding.
2. The scroll compressor according to item 1. 3. The wrap according to claim 1, wherein the offset is applied to the outside of the winding start of the wrap.
2. The scroll compressor according to item 1. 4. The scroll compressor according to claim 1, wherein the amount of offset in the thickness direction of the wrap is substantially constant regardless of the winding angle of the wrap. 5. The scroll compressor according to claim 1, wherein the amount of offset in the thickness direction of the wrap decreases as the winding angle of the wrap increases. 6. At a winding end position of at least one of the fixed scroll and the movable scroll, one wall of one of the wraps at the winding end position has a first plane portion, and the first plane portion thereof. 2. The scroll compressor according to claim 1, wherein a wall of the other wrap opposite to the first wrap has a second flat portion that can face the first flat portion by a predetermined length. 3. 7. A crankshaft rotatable around a rotary shaft, a bearing supporting the crankshaft, a fixed scroll, and the crankshaft eccentric by a predetermined amount so as to orbit with respect to the rotary shaft. A movable scroll, a thrust bearing that supports the movable scroll, and a compression mechanism having an Oldham coupling that restrains the rotation of the movable scroll.The fixed scroll and the movable scroll each have a spiral shape. A wrap, at a winding end position of at least one of the fixed scroll and the movable scroll, one wall of one of the wraps at the winding end position has a first flat portion, and the first flat portion thereof The wall of the other lap opposite to the first flat portion has a second flat portion that can face the first flat portion for a predetermined length. Scroll compressor. 8. The first flat portion and / or the second flat portion.
The flat portion is provided in a tangential direction of the wrap at an end on the winding end side of the wall of the wrap in a portion where the first flat portion or the second flat portion is not provided. A scroll compressor according to claim 7. 9. The method according to claim 9, wherein the first flat portion is formed on the inner wall of the wrap at the winding end position of the movable scroll.
The scroll compressor according to claim 7, wherein the flat portion is provided on an outer wall of the wrap of the fixed scroll, respectively. 10. The method according to claim 1, wherein the first flat portion is provided on an inner wall of the wrap at the winding end position of the fixed scroll, and the second flat portion is provided on an outer wall of the wrap of the movable scroll. A scroll compressor according to claim 7. 11. At the winding end position of the wrap provided with the first flat portion, the outer wall of the wrap at the winding end position has a third flat portion, and the other wall facing the third flat portion. The scroll compressor according to claim 9, wherein the inner wall of the wrap has a fourth flat portion that can face the third flat portion at least a predetermined length. 12. The outer wall of the wrap of the orbiting scroll at a second position substantially closer to the start of winding by 180 deg from the end of the wrap of the movable scroll has a third flat portion, and the outer wall of the wrap opposes the third flat portion. The scroll compressor according to claim 9, wherein a wall of the wrap of the fixed scroll has a fourth flat portion that can face the third flat portion by a predetermined length. 13. All or a part of the first plane portion, the second plane portion, the third plane portion, and the fourth plane portion, at least one groove having a depth in a thickness direction of the wrap. The scroll compressor according to any one of claims 7 to 12, comprising: 14. All or a part of the first flat portion, the second flat portion, the third flat portion, and the fourth flat portion have a displacement surface displaced in a direction in which the thickness of the wrap becomes thin. The scroll compressor according to any one of claims 7 to 12, comprising: 15. The scroll compressor according to claim 14, wherein the displacement amount of the displacement surface is 3 to 20% of the thickness of the spiral-shaped portion of the wrap.