JP2003206871A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of a scroll compressor by improving a refrigerant leak preventing structure. <P>SOLUTION: In this scroll compressor, a fixed scroll 14 and a turning scroll 15 are installed in a easing 11 and the turning scroll 15 is turned by a drive shaft 12 to compress gas. The end plate 15a of the turning scroll 15 is formed in a half-split body having a swirl side member 25 on the fixed scroll 14 side and an eccentric side member 26 on the drive shaft 12 side. A hole 27 extending in the axial direction of the drive shaft 12 is provided in the divided surface 25a of the swirl side member 25 facing the eccentric side member 26, and a through hole 28 extending in the axial direction in communication with the hole 27 is provided in the divided surface 26a of the eccentric side member 26 facing the swirl side member 25. A pin 29 is slidably fitted into the holes 27 and 28, and an energizing means is installed to energize the swirl side member 25 and the eccentric side member 26 in a direction to separate these members from each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a scroll compressor, and more particularly to a scroll compressor suitable as a scroll compressor for a vapor compression refrigeration cycle using a refrigerant such as carbon dioxide in a supercritical range.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of environmental protection, in a vapor compression refrigeration cycle, a refrigeration cycle using carbon dioxide (CO ₂ ) as a refrigerant (hereinafter referred to as a CO ₂ cycle) as one of measures for dechlorofluorocarbon of the refrigerant. Has been proposed (for example, Japanese Patent Publication No. 7-18602). The operation of this CO ₂ cycle is similar to that of the conventional vapor compression refrigeration cycle using chlorofluorocarbon. That is, in the CO ₂ Mollier diagram of FIG.
As shown by -B-C-D-A, in compressing the CO ₂ in the vapor phase by a compressor (A-B), the radiator of CO ₂ in the gas phase state of this hot pressing (gas cooler) Cool (B-
C). Then, the pressure is reduced by a decompressor (C-D), CO ₂ in a gas-liquid phase state is evaporated (D-A), and latent heat of vaporization is taken from an external fluid such as air to cool the external fluid.

By the way, since the critical temperature of CO ₂ is about 31 °, which is lower than the critical point temperature of CFC which is a conventional refrigerant, CO ₂ on the radiator side when the outside temperature is high such as in summer.
Temperature becomes higher than the critical point temperature of CO ₂ ,
CO ₂ does not condense on the radiator outlet side (the line segment BC does not intersect the saturated liquid line SL). In addition, the radiator outlet side (C
The state of point) is the discharge pressure of the compressor and C at the radiator outlet side.
It is determined by the O ₂ temperature, and the CO ₂ temperature at the radiator outlet side is determined by the heat radiation capacity of the radiator and the outside air temperature (uncontrollable). Therefore, the temperature at the radiator outlet should be controlled substantially. I can't. Therefore, the radiator outlet side (C
The state of point) is the discharge pressure of the compressor (radiator outlet side pressure)
Can be controlled by controlling. That is, when the outside air temperature is high such as in summer, in order to secure a sufficient cooling capacity (enthalpy difference), it is necessary to increase the radiator outlet side pressure as indicated by E-F-G-HE. is there. Therefore, it is necessary to increase the operating pressure of the compressor as compared with the conventional refrigeration cycle using CFCs. Taking a vehicle air conditioner as an example, the operating pressure of the compressor is R13 of the conventional compressor.
4a (CFC) refrigerant is about 3 kg / cm ² , CO ₂ is as high as 40 kg / cm ^2, and operation stop pressure is about 15 kg / cm ² for R134a (CFC) refrigerant. CO ₂ is as high as about 100 kg / cm ² .

As a compressor using the CO ₂ cycle, for example, like the scroll compressor described in Japanese Patent Application Laid-Open No. 11-161690, leakage of CO ₂ gas that occurs between fixed and orbiting scrolls due to high operating pressure is prevented. Some have adopted means for. As shown in FIG. 5, the means is an end plate 101 of an orbiting scroll 100 that constitutes a compression mechanism by being combined with a fixed scroll (not shown).
Is a halved body of the spiral side portion 102 on the fixed scroll side and the eccentric side portion 103 on the eccentric shaft side, and the spiral side portion 102 is supported movably in the axial direction with respect to the eccentric side portion 103. A leaf spring 104 is provided between the spiral side portion 102 and the eccentric side portion 103 on the eccentric shaft side. The elastic force of the leaf spring 104 is formed between the spiral side portion 102 and the eccentric side portion 103. Space 105a, 1
By pressing the spiral side portion 102 against the fixed scroll by using the pressure of the compressed refrigerant introduced into 05b, CO ₂
It is to prevent gas leakage.

[0005]

By the way, in the scroll compressor provided with the structure for preventing leakage of CO ₂ gas as described above, the spiral side portion 102 and the eccentric side portion 103 are provided.
Since it is necessary to provide the pin 106 for supporting the leaf spring 104 and the spiral side portion 102 while securing the spaces 105a and 105b for introducing the CO ₂ gas therebetween, the end plate 101 must be enlarged in the radial direction. As a result, the scroll compressor itself tends to increase in size.

On the other hand, R134 is not limited to the CO ₂ cycle.
Even in the refrigeration cycle using HFC refrigerants such as a, increasing efficiency by preventing leakage of the compressed refrigerant in the compressor and miniaturization of the compressor have become more and more important issues. The present invention has been made in view of the above circumstances, and an object of the present invention is to improve a structure for preventing refrigerant from leaking and to downsize a scroll compressor.

[0007]

As a means for solving the above problems, a scroll compressor having the following structure is adopted. That is, the present invention according to claim 1 includes, in a casing, a fixed scroll and an orbiting scroll that is combined with the fixed scroll to form a compression chamber,
In a scroll compressor that discharges the refrigerant introduced into the casing by compressing the refrigerant introduced into the casing by rotating the orbiting scroll around a drive shaft, the end plate of the orbiting scroll is a spiral side member on the fixed scroll side. And a eccentric side member on the side of the drive shaft, and a hole extending in the axial direction of the drive shaft is provided in the divided surface of the spiral side member facing the eccentric side member. The divided surface of the eccentric side member facing the side member is provided with a hole communicating with the hole and also extending in the axial direction, and the hole and the hole are slidable with respect to at least one of them. It is characterized in that the shafts are fitted to each other, and a biasing means is provided for biasing the spiral side member and the eccentric side member in a direction of separating from each other.

In the present invention, the shaft is slidably fitted in the hole provided in the split surface of the spiral side member facing the eccentric side member and the hole provided in the split surface of the eccentric side member facing the spiral side member. With this structure, the space for arranging the shaft that functions as a guide can be secured without enlarging the end plate of the orbiting scroll (specifically, on the back surface of the spiral side member). It will be possible to place). Therefore, the scroll compressor is prevented from increasing in size due to the addition of the refrigerant leakage prevention structure.

According to a second aspect of the present invention, in the scroll compressor according to the first aspect, the hole and the hole and the shaft fitted in both of them are separated from each other in the circumferential direction of the orbiting scroll. It is characterized by being provided.

In the present invention, since the spiral side member is supported by the shaft at a plurality of points, the stability of the spiral side member is improved, rattling is suppressed, and durability is improved.

According to a third aspect of the present invention, in the scroll compressor according to the first aspect or the second aspect, the urging means causes the refrigerant pressurized in the compression chamber to flow into the spiral side member and the refrigerant. It is characterized in that it is guided to the eccentric side member and is biased in the direction of separating the spiral side member and the eccentric side member by the pressure of the refrigerant.

In the present invention, by utilizing the pressure of the refrigerant, the urging force can be obtained without increasing the number of parts. Moreover, since the urging force does not change with time, it is also excellent in durability.

The present invention described in claim 4 is the same as claim 1,
The scroll compressor according to any one of 2 and 3 is characterized in that the biasing means is an elastic body interposed between the spiral side member and the eccentric side member.

In the present invention, a constant biasing force is always obtained by utilizing the elastic body.

The present invention according to claim 5 provides the invention according to claim 2,
In the scroll compressor according to any one of 3 and 4, the other end of the shaft is provided so as to penetrate the eccentric side member, and the other end forms a part of a rotation preventing mechanism of the orbiting scroll. To do.

In the present invention, the number of parts is reduced by sharing the parts in the refrigerant leakage prevention structure and the rotation preventing mechanism of the orbiting scroll.

According to a sixth aspect of the present invention, in the scroll compressor according to the fifth aspect, the rotation preventing mechanism comprises:
A circular concave portion formed in a bearing portion that supports the orbiting scroll, and a protrusion that is provided on the orbiting scroll side and moves along a circular peripheral surface of the concave portion, and the other end of the shaft is the protrusion. It is characterized by

In the present invention, by sharing the parts as described above, the deterioration of the quality of the product due to the accumulation of the assembly error can be suppressed. For example, if there are many parts to be assembled, many assembly errors will occur at each assembly position, which may result in quality deterioration of the finished product.However, sharing parts reduces the assembly parts. As a result, the accumulated assembly error is reduced accordingly, so that the product quality is maintained at a high level. Furthermore, by sharing the parts, the amount of twist between the eccentric side member and the spiral side member is reduced during operation of the compressor, so the amount of twist between the fixed scroll and the orbiting scroll is also reduced, resulting in high efficiency. Can be realized.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a scroll compressor according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the overall configuration of a scroll compressor included in an air conditioner for an automobile. In the drawings, reference numeral 11 indicates a casing. The casing 11 sandwiches the center plate 11b between the cup-shaped main body 11a, the center plate 11b arranged on the open end side of the main body 11a, and the main body 11a. It is composed of an end plate 11c.

The main body 11a has a crankshaft 12a at one end.
And a drive shaft 12 fixed to a pulley P with a built-in magnet clutch penetrates through the other end.
Are rotatably supported by the main body 11a via bearings 13a and 13b.

A fixed scroll 14 and an orbiting scroll 15 are disposed inside the casing 11. The fixed scroll 14 has a structure in which a spiral wrap 14b is integrally formed on an end plate 14a which also serves as a center plate 11b, and is fastened to a main body 11a together with an end plate 11c by a bolt 16.

The orbiting scroll 15 comprises an end plate 15a and a spiral wrap 15b provided on one end surface of the orbiting scroll 15a. The orbiting scroll 15 is seated on a bearing portion 11d inside the main body 11a and is rotatably supported. ing. The spiral wrap 15 b has substantially the same shape as the spiral wrap 14 b of the fixed scroll 14. The orbiting scroll 15 and the fixed scroll 14 are eccentric to each other by the orbiting radius and are meshed with each other with a phase shift of 180 °, and a crescent-shaped compression chamber C is defined between the spiral wraps of each other. When the orbiting scroll 15 revolves with respect to the scroll 14, the contact portions of the spiral wraps 14b and 15b gradually move to the center of the spiral, and the compression chamber C also decreases to the center of the spiral along with this. The refrigerant gas that has moved and taken into the compression chamber C is pressurized and compressed.

A suction chamber 18 is defined between the main body 11a and the center plate 11b, and the suction port 1 is formed in the main body 11a.
8a is formed, and the scroll compression mechanism including the fixed scroll 14 and the orbiting scroll 15 sucks the refrigerant gas into the suction chamber 18 through the suction port 18a by its own pumping action.

A discharge cavity 19 is defined between the center plate 11b and the end plate 11c, and a discharge port 19a for connecting the suction chamber 18 and the discharge cavity 19 is formed in the center plate 11b. A discharge valve 20 that opens to the discharge cavity 19 side when a predetermined pressure is applied is attached to the discharge port 19a, and gas pressurized to a predetermined pressure or higher by the scroll compression mechanism pushes the discharge valve 20 open. It is adapted to be discharged into the discharge cavity 19. Further, a cyclone type oil separator 21 is integrally formed with the end plate 11c.

A cylindrical boss 22 is provided at the center of the other end surface of the end plate 15a of the orbiting scroll 15, and a crankshaft 12a is rotatably inserted into the boss 22 via a drive bush 23. Has been done. Further, between the outer edge portion of the other end surface of the end plate 15a and the bearing portion 11d of the main body 11a, the orbiting scroll 15 is provided via a static pressure assist bearing 24.
A mechanism is provided for supporting rotation of the shaft while blocking its rotation (this "rotation blocking mechanism" will be described later).

The end plate 15a of the orbiting scroll 15 is divided into two parts, a spiral side member 25 having a spiral wrap 15b and an eccentric side member 26 provided with a boss 22. As shown in FIG. 2, a hole 27 extending in the axial direction of the drive shaft 12 is formed in the split surface 25 a of the spiral side member 25 facing the eccentric side member 26, while the eccentricity facing the spiral side member 25 is formed. A through hole 28 that communicates with the hole 27 and that also extends in the axial direction of the drive shaft 12 is formed in the divided surface 26 a of the side member 26. A pin (shaft) 29 is fitted into the hole 27 and the through hole 28 that are continuous in the axial direction of the drive shaft 12 so that one end 29 a of the pin 29 is slidable with respect to the hole 27. These holes 27, through holes 28 and pins 29
The four link mechanisms are provided at equal intervals in the circumferential direction of the orbiting scroll.

A groove 30 is formed on the dividing surface 26a of the eccentric side member 26 so as to be concentric with the boss 22 on the back surface. On the other hand, on the dividing surface 25a of the spiral side member 25, a ridge portion 31 matching the groove 30. Are formed. A slight gap is provided between the bottom surface of the groove 30 and the end surface of the convex stripe portion 31, and U-seals 32, 3 are provided along the groove 30 inside and outside the gap.
3 is arranged to define a space S1. Also, the groove 3
There is also a slight gap between the dividing surface 25a located inside 0 and the dividing surface 26a located inside the ridge portion 31, and this portion also has a space S2 by the U seal 33.
Is defined in.

The vortex side member 25 is used as urging means for urging the vortex side member 25 and the eccentric side member 26 in the direction of separating from each other.
The compression chamber C1 and the space S where the gas pressure is raised to a medium level.
1 and a pressure introducing hole 35 which connects the space S2 with the compression chamber C2 in which the gas pressure is increased to a high pressure close to the discharge pressure. As a result, the space S1
A medium gas pressure acts on the space S2 as in the compression chamber C1 and a very high gas pressure acts on the space S2 as in the compression chamber C2. Generates a force that biases the two in the direction of separating them. This structure is excellent in that the biasing force can be obtained without increasing the number of parts such as the elastic body.

The other end of each of the four pins 29 penetrates the eccentric side member 26 and projects to form a protrusion 29b.
Each of the protrusions 29b is loosely fitted in a recess 36 provided corresponding to each of the bearing portions 11d to form a rotation preventing mechanism of the orbiting scroll 15. The recess 36 is circular when viewed in plan from the side of the orbiting scroll 15 in the axial direction, and its radius is equal to the amount of eccentricity of the orbiting scroll 15, and is formed at a uniform depth. As shown in FIG.
6 is always in contact with the circular peripheral surface of 6, and when the drive shaft 12 rotates, the orbiting scroll 15 is prevented from rotating by the projection 29b loosely fitted in the recess 36 and contacting the peripheral surface.
The 9b moves along the peripheral surface of the recessed portion 36 to make a revolution revolution.

In the scroll compressor having the above-mentioned structure, the orbiting scroll 1 is constructed by using the link mechanism including the hole 27, the through hole 28 and the pin 29.
Even if the end plate 15a of No. 5 is not enlarged, it is possible to secure a space for arranging the pin 29 that functions as a guide. Specifically, by arranging the link mechanism on the back surface of the spiral side member 25, as a result, it was possible to suppress the increase in size of the scroll compressor.

Further, since the leakage prevention mechanism for preventing the leakage of the gas filled in the compression chamber C and the rotation prevention mechanism for the orbiting scroll 15 share the component (pin 29),
The number of parts has been reduced, and it has become possible to reduce costs and improve workability during assembly.

Moreover, by sharing the parts as described above, it is possible to suppress the deterioration of the quality of the product due to the accumulation of the assembly error. In other words, if parts are separately prepared for the leak prevention mechanism and the rotation prevention mechanism, assembly errors occur at two locations and the errors are accumulated, so that the quality of the finished scroll compressor is reduced by the error. Although this may occur, since the assembling portion is reduced to one place by sharing the pin 29, the assembling error is reduced and the product quality is maintained at a high level.

Further, since the pin 29 is shared, the amount of twist between the eccentric side member 26 and the spiral side member 25 is reduced during operation of the compressor, so that the twist between the fixed scroll 14 and the orbiting scroll 15 is increased. The volume was also reduced, and the definition of the compression chamber by the spiral wrap was made finer, which made it possible to achieve higher efficiency.

Although the scroll compressor provided in the air conditioner of the automobile has been described in this embodiment, the scroll compressor according to the present invention is not limited to the air conditioner of the automobile. It can be installed in any device. In the present embodiment, the compression chamber C1,
The urging means for separating the spiral side member 25 and the eccentric side member 26 from each other by introducing the gas pressure in C2 between the spiral side member 25 and the eccentric side member 26 is adopted. For example, an elastic body such as a leaf spring may be interposed between the spiral side member 25 and the eccentric side member 26 to form a similar biasing means. This is advantageous in that the biasing force can be made uniform by separately using the elastic body. The two urging means may be combined.

[0035]

As described above, according to the scroll compressor of the first aspect of the present invention, the hole provided on the split surface of the spiral side member facing the eccentric side member and the surface on the spiral side member. By adopting a structure in which the shaft is slidably fitted in the hole provided in the divided surface of the eccentric side member, there is a space for arranging the shaft that functions as a guide without enlarging the end plate of the orbiting scroll. It becomes possible to secure. Therefore, it is possible to prevent the scroll compressor from increasing in size due to the addition of the refrigerant leakage prevention structure.

According to the scroll compressor of the second aspect, since the spiral side member is supported by the shaft at a plurality of points, the stability of the spiral side member is improved, rattling is suppressed, and durability is improved. Since the property is improved, stable operation can be realized.

According to the scroll compressor of the third aspect, the pressure of the refrigerant is used as the biasing means, so that the biasing force can be obtained without increasing the number of parts. Therefore, the cost can be reduced and the assembling workability can be improved. Can be achieved. Moreover, since the urging force does not change with time, it is also excellent in durability, and this also makes it possible to realize stable operation.

According to the scroll compressor of the fourth aspect, by using the elastic body for the biasing means, a constant biasing force can always be obtained and the efficiency of compression performance can be improved.

According to the scroll compressor of the fifth aspect, since the number of parts is reduced by sharing the parts between the refrigerant leakage prevention structure and the orbiting scroll rotation preventing mechanism, the cost is also reduced. Workability of down and assembly can be improved.

According to the scroll compressor of the sixth aspect, by sharing the parts as described above, it is possible to suppress the quality deterioration of the product due to the accumulation of the assembly error and to maintain the high quality. Furthermore, since the amount of twist between the fixed scroll and the orbiting scroll is reduced by sharing the parts, the compression efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a scroll compressor according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a link mechanism.

FIG. 3 is a perspective view showing a mechanism of a rotation preventing mechanism.

FIG. 4 is a Mollier diagram of carbon dioxide.

FIG. 5 is a cross-sectional view showing the structure of a refrigerant leakage prevention mechanism in a conventional scroll compressor.

[Explanation of symbols]

11 casing 12 drive shaft 14 fixed scroll 15 orbiting scroll 15a End plate 25 Swirl side member 26 Eccentric side member 25a split surface 26a division plane 27 holes 28 through holes 29 pin (axis) 29b protrusion S1, S2 space 34,35 Pressure introduction hole 36 recess C compression chamber

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuzo Ukai             3-1, Asahi-cho, Nishibiwajima-cho, Nishikasugai-gun, Aichi             Address Mitsubishi Heavy Industries Co., Ltd. F-term (reference) 3H029 AA02 AA17 AB03 AB05 BB04                       BB16 BB32 BB43 CC05 CC19                       CC54                 3H039 AA02 AA12 BB01 BB15 BB28                       CC08 CC24 CC25 CC31

Claims (6)

[Claims] 1. A casing is provided with a fixed scroll and an orbiting scroll which is combined with the fixed scroll to form a compression chamber, and the refrigerant introduced into the casing by orbiting the orbiting scroll by a drive shaft is provided. In a scroll compressor that discharges after compressing in the compression chamber, the end plate of the orbiting scroll is a half body of a scroll side member on the fixed scroll side and an eccentric side member on the drive shaft side, and the eccentricity The split surface of the spiral side member facing the side member is provided with a hole extending in the axial direction of the drive shaft, and the split surface of the eccentric side member facing the spiral side member,
A hole that also communicates with the hole and extends in the axial direction is provided, and a shaft is slidably fitted in at least one of the hole and the hole, and further, the spiral side member and the eccentric side member A scroll compressor, characterized in that it is provided with a biasing means for biasing the and. 2. The scroll compressor according to claim 1, wherein a plurality of the holes and the shafts fitted in the holes are provided in the circumferential direction of the orbiting scroll so as to be separated from each other. 3. The urging means guides the refrigerant pressurized in the compression chamber between the spiral side member and the eccentric side member, and the pressure of the refrigerant causes the spiral side member and the eccentric side member to move. 3. The scroll compressor according to claim 1, wherein the scroll compressor is urged in a direction in which the and are separated from each other. 4. The urging means is an elastic body interposed between the spiral side member and the eccentric side member, and the urging means is an elastic body. Scroll compressor. 5. The other end of the shaft is provided so as to penetrate the eccentric side member, and the other end forms a part of a rotation preventing mechanism of the orbiting scroll.
Any one of the scroll compressors. 6. The rotation preventing mechanism includes a circular recess formed in a bearing portion that supports the orbiting scroll, and a protrusion that is provided on the orbiting scroll side and moves along a circular peripheral surface of the recess. The scroll compressor according to claim 5, characterized in that the other end of the shaft forms the protrusion.