JP2002155875A - Scroll compressor - Google Patents

Abstract

[PROBLEMS] To reduce the centrifugal force of a driving part during high-speed operation, improve durability, reduce sliding loss, and effectively reduce leakage loss in all operating regions. To do. SOLUTION: A fixed scroll component 5 and an orbiting scroll component 6 are formed of metal materials having different thermal expansion coefficients, and a wrap thickness T1 having a larger thermal expansion coefficient is made thicker than a wrap thickness having a smaller thermal expansion coefficient, so that thermal expansion is achieved. Scroll component 6 with large coefficient
Rise of the spiral wrap 4 having the larger thermal expansion coefficient so that the gap G in the thrust direction between the spiral wrap 4 and the end plate 1 of the scroll component 5 having the smaller thermal expansion coefficient increases from the outer peripheral side to the center side. The above object is achieved by providing the end 4c with a longitudinal inclination.

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 cooling device such as a cooling / heating machine or a refrigerator.

[0002]

2. Description of the Related Art There are reciprocating compressors, rotary compressors, and scroll compressors as hermetic compressors for refrigeration and air conditioning, and all of them have been used in home and commercial refrigeration and air conditioning fields. ing. At present, it is growing by making use of its features in terms of cost and performance.

[0003] Among them, a compressor in which a compression mechanism and an electric mechanism are housed in a container is represented by a so-called hermetic compressor intended for soundproofing and maintenance-free, and a scroll compressor and a rotary compressor are mainly used. Generally, as shown in FIG. 3, a scroll compressor meshes a fixed scroll component e and a orbiting scroll component f in which spiral wraps c and d rise from end plates a and b to form a compression chamber g between the two. When the component f is rotated along a circular orbit under the rotation restriction by the rotation restricting mechanism h, the compression chamber g moves while changing the volume to perform suction, compression, and discharge, and the outer periphery of the orbiting scroll component f A predetermined back pressure is applied to the back surface of the portion and the portion where the spiral wrap d is formed by lubricating oil so that the orbiting scroll component f does not separate from the fixed scroll component e and capsize.

The refrigerant gas sucked from the suction pipe i passes through the suction chamber j of the fixed scroll component e and is confined in the compression chamber g between the orbiting scroll component f and compressed while decreasing its volume toward the center. Is discharged from the discharge port k. The back pressure chamber m formed by being surrounded by the fixed scroll component e and the bearing member 1 has an intermediate pressure between high and low pressures, and the back pressure adjusting mechanism n controls the intermediate pressure to be constant. The back pressure adjusting mechanism n is provided with a valve p in a passage o communicating from the back pressure chamber m to the suction chamber j through the inside of the fixed scroll component e, and the pressure of the back pressure chamber m is set. When the pressure becomes higher than the pressure, the valve p is opened, the oil in the back pressure chamber m is supplied to the suction chamber j, and the back pressure chamber m is maintained at a constant intermediate pressure. Further, the oil supplied to the suction chamber j moves to the compression chamber g together with the swirling motion, which helps prevent leakage between the compression chambers. The above-described intermediate pressure is applied to the back surface of the orbiting scroll component f, thereby suppressing overturning during operation. When overturned, the fixed scroll component e and the orbiting scroll component f are separated from each other, and leakage occurs at that portion.

[0005] As the material of the fixed scroll component e and the orbiting scroll component f constituting the scroll compressor, an iron system mainly made of cast iron is used for both, or an iron system is used for the fixed scroll component e and the orbiting scroll component f. Uses an aluminum type.

[0006]

By the way, the present inventor has found that when the fixed scroll component e and the orbiting scroll component f are made of a metal or iron-based material having the same thermal expansion coefficient, the orbiting scroll component is not used. Since the specific gravity of f increases, the centrifugal force during operation increases. As a result, the bearing load increases and the sliding loss increases. In particular, during high-speed operation, the centrifugal force becomes extremely large, so that the main shaft q and the bearing member l are severely worn and lack durability. In order to increase the accuracy of the spiral wraps c and d, it is necessary to precisely machine the mounting surface and the sliding surface. However, since the ferrous material has low machinability, the machining is extremely difficult and the productivity is improved. It is difficult to do.

Therefore, when a metal having a different coefficient of thermal expansion such as an iron-based material is used for the fixed scroll component e and an aluminum-based material is used for the orbiting scroll component f, a metal is formed between the fixed scroll component e and the orbiting scroll component f. Since each compression chamber g performs compression action, compression heat is generated, and this heat causes the fixed and orbiting scroll components e and f to become high in temperature. Then, the pressure in each compression chamber g gradually increases from the outer circumference side compression chamber g toward the center side compression chamber g.
, A temperature gradient is generated from the outer peripheral side toward the central side. That is, the center compression chamber g has a higher temperature than the outer circumference compression chamber g. Due to this increase in temperature, the portions of the spiral wraps c and d thermally expand, and the side of the spiral wraps c and d, which is located particularly at the center where the temperature becomes high, greatly expands. For this reason, at the time of thermal expansion of each spiral wrap c, d, each spiral wrap c,
The gap in the thrust direction between the rising end of the d portion and each of the end plates a and b is smaller than the gap size at the time of assembly,
The rising ends of the spiral wraps c and d are the respective end plates a and b.
Contact with. Further, when the contact surface pressure is increased, galling occurs with each other, and there is a possibility that each of the end plates a and b and each of the spiral wraps c and d may be damaged, and the compression efficiency and durability of the compressor are reduced. There is. In order to avoid this, the gap in the thrust direction between the fixed and orbiting scroll components e and f must be increased, which leads to an increase in leakage of the compressed fluid such as a refrigerant, resulting in a decrease in performance. are doing.

Further, in order to avoid a decrease in performance due to the presence of the gap in the thrust direction, when the tip seal r is provided on one or both of the orbiting scroll component f and the fixed scroll component e, the tip seal r may come into contact. Therefore, there is a problem that productivity is reduced due to an increase in sliding loss due to the increase in the number of parts and an increase in the number of processing steps.

In a scroll compressor known in Japanese Patent Application Laid-Open No. 7-197891, etc., the spiral wraps c and d of the orbiting scroll component f or the fixed scroll component e are raised from the rising base to the rising end of the end plates a and b. Adjust the size of each spiral wrap c in the assembled state,
A thrust gap may be formed between the rising end of the part d and the other end plates a and b at the center side so as to be the largest at the center side, or the thrust gap may be determined based on the result of measuring the temperature distribution at the rising end face. Are formed so as to change in a plurality of stages. However, there is a problem that the gap in the thrust direction in the central portion is large at the time of low-speed operation where the temperature in the central portion is not high, and the leakage loss is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. By reducing the centrifugal force of a driving portion during high-speed operation, the present invention is excellent in durability, reduces sliding loss, and can be used in all operation regions. An object of the present invention is to provide a high-efficiency scroll compressor that effectively reduces leakage loss.

[0011]

SUMMARY OF THE INVENTION A scroll compressor according to the present invention forms a compression chamber between both a fixed scroll component and a revolving scroll component in which a spiral wrap rises from a head plate, and restrains the revolving scroll component from rotating. When swiveling along a circular orbit under the pressure, the compression chamber moves while changing the volume, thereby performing suction, compression and discharge, and applies a predetermined back pressure to the outer peripheral portion of the orbiting scroll component and its back surface. In the above configuration, the fixed scroll component and the orbiting scroll component are formed of metal materials having different thermal expansion coefficients, and the wrap thickness of the metal material having a large thermal expansion coefficient is smaller than that of the metal material having a smaller thermal expansion coefficient. The main feature is that it is thicker.

In such a configuration, the centrifugal force of the drive section during high-speed operation is reduced by applying the side using the metal material having a large thermal expansion coefficient to the turning side, so that friction between the drive section and the bearing member is reduced. While reducing sliding loss and improving durability and operating efficiency, at the same time, the amount of thermal expansion at the time of temperature increase is increased by increasing the thickness of the spiral wrap, and as the temperature increases, the coefficient of thermal expansion decreases. Since the gap between the counterpart made of the material is reduced and the sealing performance is sufficiently increased at each time, the leakage loss can be effectively reduced in the entire operation range, and the compression performance is improved.

The present invention also provides, in addition to the above main features,
The thrust gap between the spiral wrap in a scroll component formed using a metal material having a large thermal expansion coefficient and the end plate in a scroll component formed using a metal material having a low thermal expansion coefficient is changed from the outer peripheral side to the inner peripheral side. A further feature is that a longitudinal inclination is provided at the rising end of the spiral wrap using a metal material having a large coefficient of thermal expansion so as to increase the height.

In such a configuration, the scroll component made of a metal material having a large thermal expansion coefficient also thermally expands in the rising direction of the spiral wrap as the temperature rises, thereby forming a gap in the thrust direction with a counterpart having a small thermal expansion coefficient. As described above, the sealing performance is enhanced by reducing the size, but the rising end of the spiral wrap has a slope opposite to the temperature gradient in which the temperature rises from the outer peripheral side toward the center side, and the amount of thermal expansion increases. The rise is low on the center side and high on the outer circumference where the amount of thermal expansion is small,
The other end of the spiral wrap has a small coefficient of thermal expansion at each part from the outer periphery to the center as the temperature rises by freely suppressing the difference in the amount of thermal expansion due to the difference in temperature rise between the outer periphery and the center. The gap in the thrust direction can be prevented from being excessive or insufficient, so that the leakage loss can be effectively reduced without increasing the sliding loss due to excessive contact.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a scroll compressor according to an embodiment of the present invention will be described in detail with reference to FIGS.

This embodiment is a scroll compressor of the type shown with reference to FIG. 3, in which the fixed scroll component 5 and the orbiting scroll component 6 shown in FIG. 1 and FIG. It is a maintenance-free type housed in a container together with a driving motor.

The compression mechanism 10 will be briefly described for the following description. The fixed scroll component 5 and the orbiting scroll component 6 in which the spiral wraps 3, 4 rise from the end plates 1, 2 are engaged to form a compression chamber 7 therebetween. When the orbiting scroll component 6 is turned along a circular orbit by an electric motor and a drive shaft (not shown) under the rotation constraint by a rotation constraint mechanism (not shown), the compression chamber 7 changes its volume from the outer peripheral side to the central side while changing its volume. By moving and decreasing the volume,
A predetermined back pressure is applied to the outer peripheral portion of the orbiting scroll component 6 and its rear surface under pressure regulation by the pressure regulating valve 20 while performing suction, compression through the suction port 11 and discharge through the discharge port 12, and the fixed scroll. The component 5 and the orbiting scroll component 6 are stably engaged with each other, and the same operation as in the related art can be performed.

In the present embodiment, in particular, the fixed scroll component 5 and the orbiting scroll component 6 are formed of metal materials having different thermal expansion coefficients, and a metal having a large thermal expansion coefficient is used. Wrap thickness T1
As shown in FIGS. 1 and 2, the smaller the coefficient of thermal expansion, for example, the thickness of the wrap thickness T <b> 2 of the fixed scroll component 5 is made thicker. A metal material having a small thermal expansion coefficient is preferably an iron-based material, and a metal material having a large thermal expansion coefficient is preferably an aluminum-based material. However, the present invention is not limited to this. Basically, the above object of the present invention can be achieved by selecting two kinds of metal materials having different coefficients of thermal expansion.

As described above, by applying the side using the metal material having a large thermal expansion coefficient to the orbiting scroll component 6, the weight can be reduced as compared with the case of using the iron-based material, and the weight can be reduced. By only reducing the centrifugal force of the drive unit during high-speed operation, it is possible to reduce friction and sliding loss between the drive shaft and a bearing member (not shown) that receives the drive shaft. With these, durability and operation efficiency can be improved. At the same time, the thickness T1 on the side of the spiral wrap 4 made of a metal material having a large thermal expansion coefficient is larger than that of the spiral wrap 3 made of a metal material having a small thermal expansion coefficient by the same amount as when the temperature is not increased. As the temperature rises, the gap between the fixed scroll component 5 which is a counterpart having a small thermal expansion made of a metal material having a small thermal expansion coefficient is reduced as the temperature rises, thereby improving the sealing performance. Since it is sufficiently increased, the leakage loss can be effectively reduced in the entire operation range, and the compression performance is improved. Such a sealing effect due to the difference in thermal expansion is exerted on the fixed scroll component 5 and the orbiting scroll component 6 on the side made of a metal material having a high thermal expansion coefficient.

The spiral wrap 4 in, for example, the orbiting scroll component 6 formed by using a metal material having a large thermal expansion coefficient and the end plate 1 in, for example, the fixed scroll component 5 formed by using a metal having a small thermal expansion coefficient. The gap G in the thrust direction between the outer side 4a and the center side 4b
The rising end 4c of the spiral wrap 4 on the side of the orbiting scroll component 6 using a metal material having a large thermal expansion coefficient is provided with a longitudinal inclination as shown in FIG.

The orbiting scroll component 6 made of a metal material having a large coefficient of thermal expansion is supplied to the spiral wrap 4 with increasing temperature.
Of the fixed scroll component 5 having a small coefficient of thermal expansion in the thrust direction with the end plate 1 to increase the sealing performance as described above. 4 rising edge 4c
However, it has a slope opposite to the temperature gradient in which the temperature rise in the compression process increases from the outer peripheral side toward the center side, the rise is low on the central side where the amount of thermal expansion increases, and on the outer peripheral side where the amount of thermal expansion decreases Since the rise is higher, the difference in the amount of thermal expansion due to the difference in the temperature rise between the outer peripheral side and the center side is freely suppressed, and as the temperature rises, the spiral wrap 4 moves from the outer peripheral side to the center side. Since the gap G in the thrust direction with the end plate 1 of the fixed scroll component 5 which is a partner having a small coefficient of thermal expansion in each of the leading portions can be prevented from being excessive or insufficient, an increase in sliding loss due to excessive contact is caused. And the leakage loss can be effectively reduced.

That is, since the compression heat is generated at the central portion in the compression process and the temperature becomes higher, the rising end 4c on the central side of the spiral wrap 4 becomes higher due to thermal expansion and comes into contact with the end plate 1 of the fixed scroll component 5. And leakage of the compressed fluid, such as refrigerant, exceeding the rising end 4c can be minimized. In other words, the proximity of the rising end 4c of the spiral wrap 4 to the end plate 1 can be uniform over the entire region in the longitudinal direction. It is also possible to easily cope with the tendency that leakage is likely to occur on the side. From such a feature, there is also an advantage that it is not necessary to provide a tip seal as in the related art.

[0023]

According to the present invention, as is apparent from the above description, by reducing the centrifugal force of the driving part during high-speed operation, the durability is excellent, the sliding loss is reduced, and the entire operating range is reduced. In this case, the leakage loss can be effectively reduced.

Further, the difference in the amount of thermal expansion in the rising direction due to the difference in the temperature rise between the outer peripheral side and the central side of the spiral wrap is freely suppressed, and as the temperature rises, the outer peripheral side of the spiral wrap moves from the central side to the central side. The gap in the thrust direction with the partner with a small coefficient of thermal expansion in each part up to the point in the thrust direction can be prevented from becoming excessive or insufficient, so that the leakage loss can be effectively reduced without increasing the sliding loss due to excessive contact. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view showing an engaged state of spiral wraps of a fixed scroll component and a revolving scroll component of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a state where the fixed scroll component and the orbiting scroll component in FIG. 1 are engaged with each other.

FIG. 3 is a cross-sectional view showing one example of a conventional scroll compressor.

[Explanation of symbols]

 1, 2 End plate 3, 4 Spiral wrap 4c Rising edge 5 Fixed scroll component 6 Revolving scroll component 7 Compression chamber 11 Suction port 12 Discharge port T1, T2 Thickness G Gap in thrust direction

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Sakuda 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Kiyoshi Sano 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. 3H039 AA01 AA12 BB01 BB05 BB15 CC04 CC35

Claims (2)

[Claims] 1. A compression chamber is formed between a fixed scroll component and a revolving scroll component in which a spiral wrap rises from a head plate to form a compression chamber therebetween, and the revolving scroll component is revolved along a circular orbit under the constraint of rotation. When the compression chamber moves while changing the volume, suction, compression, and discharge are performed, and a predetermined back pressure is applied to the outer peripheral portion of the orbiting scroll component and the back surface thereof. And the orbiting scroll component is formed of a metal material having a different coefficient of thermal expansion, and a wrap thickness using a metal material having a larger coefficient of thermal expansion is made thicker than that of a material having a smaller coefficient of thermal expansion. Machine. 2. A thrust gap between a spiral wrap in a scroll component formed using a metal material having a large thermal expansion coefficient and a head plate in a scroll component formed using a metal material having a low thermal expansion coefficient is formed as an outer periphery. 2. The scroll compressor according to claim 1, wherein a rising end of the spiral wrap using a metal material having a large thermal expansion coefficient is provided with a longitudinal inclination so as to increase from a side to a center side.