JP2009008008A - Scroll compressor - Google Patents

Abstract

The pressure deformation of the orbiting scroll causes local contact with the fixed scroll, which may lead to a decrease in capacity, a rapid increase in input, and even seizure.
A clearance is provided between a wrap tip 13c of the orbiting scroll 13 and a lap groove bottom surface 12d of the fixed scroll 12, and the thickness of the end plate 13a of the orbiting scroll 13 is different between the outer peripheral portion 13o, the intermediate portion 13m, and the boss inner peripheral portion 13i. The seal member 78 is disposed on the orbiting scroll back surface 13e corresponding to the intermediate portion 13i, and the rotation restraining mechanism 14 is disposed on the orbiting scroll back surface 13e corresponding to the outer peripheral portion 13o to suppress pressure deformation.
[Selection] Figure 3

Description

  The present invention relates to a scroll compressor used in a cooling device such as a cooling / heating air conditioner or a refrigerator, or a heat pump type hot water supply device.

  Conventionally, scroll compressors used in refrigeration air conditioners and refrigerators generally have a compression chamber formed by meshing a fixed scroll and a rotating scroll where a spiral wrap rises from an end plate, and the rotating scroll is rotated by a rotation restraint mechanism. When it is swung along a circular orbit under the constraint of the above, suction, compression, and discharge are performed by moving the compression chamber while changing the volume. During operation, pressure is applied to the orbiting scroll from the back, and it is pressed against the fixed scroll side by applying high pressure on the inside and intermediate pressure on the outside with the annular seal member as a boundary. Yes. Due to this pressure deformation, local contact between the orbiting scroll and the fixed scroll occurs, and there is a possibility that the input increases and further seizure occurs. Therefore, there is a method of suppressing pressure deformation by changing the thickness of the end plate of the orbiting scroll between the outer peripheral portion and the intermediate portion (see, for example, Patent Document 1).

FIG. 5 is a cross-sectional view of a conventional orbiting scroll described in Patent Document 1. Originally, Patent Document 1 is a configuration for improving productivity, but it is cited here. As shown in FIG. 5, by changing the thickness of the end plate of the orbiting scroll 113 between the intermediate portion 113m and the outer peripheral portion 113o and increasing the thickness of the intermediate portion 113m to which high voltage is applied, deformation of the end plate 113a of the orbiting scroll 113 is suppressed. ing.
JP 2002-174187 A

  In the conventional configuration, the amount of pressure deformation of the orbiting scroll is reduced and the warpage to the fixed scroll side is suppressed, so that local contact due to pressure deformation is alleviated. However, this configuration can be used effectively only when pressure is applied from the back of the orbiting scroll and the orbiting scroll is pressed against the fixed scroll by this pressure. In the case of a so-called low-pressure compressor, the entire area on the back of the orbiting scroll is a suction pressure, and the pressure deformation of the orbiting scroll is small, so there is no need to change the thickness of the end plate of the orbiting scroll.

  The scroll compressor of the present invention operates with the orbiting scroll in contact with the fixed scroll, thereby suppressing leakage, and at the same time, regulating the lap height relationship between the orbiting scroll and the fixed scroll and the thickness of the end plate of the orbiting scroll. Thus, an object of the present invention is to provide a scroll compressor that can prevent local contact and achieve high efficiency and high reliability.

In order to solve the above-described conventional problems, the scroll compressor according to the present invention forms a compression chamber between the fixed scroll and the orbiting scroll in which the spiral wrap rises from the end plate, and forms an annular ring on the back of the orbiting scroll. A seal member is arranged, and the seal member is divided into an inner high pressure region and an outer back pressure chamber, and the orbiting scroll is brought into contact with the fixed scroll by applying suction pressure or a constant intermediate pressure to the back pressure chamber. By providing a rotation restraining mechanism on the back, the orbiting scroll revolves along a circular orbit, which causes the compression chamber to move toward the center while changing the volume, and scroll compression that performs a series of operations of suction, compression, and discharge In the machine, a clearance is provided between the wrap tip of the orbiting scroll and the bottom surface of the wrap groove of the fixed scroll,
The end plate thickness of the orbiting scroll is formed to be different between the outer peripheral part, the intermediate part, and the inner peripheral part of the boss, a seal member is arranged on the rear face of the orbiting scroll corresponding to the intermediate part, and a rotation restraining mechanism is arranged on the rear face of the orbiting scroll corresponding to the outer peripheral part. It is.

  According to this configuration, since the pressure applied at the boundary of the seal member is different, the thickness of the end plate of the orbiting scroll can be changed according to the applied pressure, and pressure deformation can be suppressed. As a result, the orbiting scroll can be operated in contact with the fixed scroll, and high efficiency can be achieved by suppressing leakage. Further, as described above, since it is possible to suppress the pressure deformation of the orbiting scroll, it is possible to prevent local contact and eliminate the risk of sudden increase in input and seizure. That is, it is possible to provide a scroll compressor that achieves high efficiency and high reliability.

  The scroll compressor of the present invention operates with the orbiting scroll in contact with the fixed scroll, thereby suppressing leakage, and at the same time, regulating the lap height relationship between the orbiting scroll and the fixed scroll and the thickness of the end plate of the orbiting scroll. As a result, local contact can be prevented, and a scroll compressor that achieves high efficiency and high reliability can be provided.

  In the first aspect of the present invention, the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate are meshed to form a compression chamber therebetween, and an annular seal member is disposed on the back of the orbiting scroll, and the seal member The inner high pressure region and the outer back pressure chamber are partitioned, and the orbiting scroll is brought into contact with the fixed scroll by applying a suction pressure or a constant intermediate pressure to the back pressure chamber, and a rotation restraining mechanism is provided on the back of the orbiting scroll. In a scroll compressor in which the orbiting scroll revolves along a circular path and the compression chamber moves toward the center while changing the volume, and performs a series of operations of suction, compression, and discharge, the wrap tip of the orbiting scroll A gap is provided between the bottom surface of the wrap groove of the fixed scroll and the end plate thickness of the orbiting scroll is different between the outer peripheral portion, the intermediate portion, and the boss inner peripheral portion. And sea urchin formed, a sealing member disposed in the orbiting scroll back falls intermediate section is obtained by arranging the rotation restraint mechanism to the orbiting scroll back corresponding to the outer peripheral portion. According to this configuration, since the pressure applied at the boundary of the seal member is different, the thickness of the end plate of the orbiting scroll can be changed according to the applied pressure, and pressure deformation can be suppressed. As a result, the orbiting scroll can be operated in contact with the fixed scroll, and high efficiency can be achieved by suppressing leakage. Further, as described above, since it is possible to suppress the pressure deformation of the orbiting scroll, it is possible to prevent local contact and eliminate the risk of sudden increase in input and seizure. That is, it is possible to provide a scroll compressor that achieves high efficiency and high reliability.

  In the present invention described in claim 2, in particular, the rotation restraint mechanism according to claim 1 is configured by an Oldham ring, and the difference in thickness between the intermediate portion and the outer peripheral portion is made larger than the thickness excluding the key portion of the Oldham ring. It is. According to this configuration, it is possible to suppress the pressure deformation of the orbiting scroll to the maximum while maintaining the axial size of the compression mechanism portion, thereby preventing local contact, rapid increase in input and seizure. The fear of reaching can be resolved.

  In the present invention described in claim 3, the end plate thickness of the inner peripheral portion of the boss described in claim 1 or 2 is particularly thinned. According to this configuration, the end plate of the inner peripheral portion of the orbiting scroll can flexibly deform and absorb the thermal expansion of the center portion of the fixed scroll under the condition that the discharge temperature of the working fluid is high, such as during overload. .

In the present invention described in claim 4, in particular, the end plate thickness of the intermediate portion described in any one of claims 1 to 3 is made the same as that of the boss portion. And according to this structure, since a boss | hub part becomes a thick structure, there is no worry of the stress concentration of a root part, and it can improve reliability regarding a turning scroll.

  According to the fifth aspect of the present invention, particularly in the scroll compressor according to any one of the first to fourth aspects, the working fluid is a high-pressure refrigerant, for example, carbon dioxide. In this case, the difference between the high pressure and the low pressure is particularly large, and the load applied to the rear surface of the orbiting scroll is also increased. Therefore, the effect of the present invention appears remarkably, and a scroll compressor that realizes high reliability can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a scroll compressor according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part of the compression mechanism portion of FIG. 1, and FIG. 3 is a detailed sectional view of the compression mechanism portion. is there. Hereinafter, operation | movement and an effect | action are demonstrated about a scroll compressor.

  As shown in FIGS. 1 and 2, the scroll compressor of the present invention includes a main bearing member 11 of a crankshaft 4 fixed by welding or shrink fitting in a sealed container 1, and a bolt on the main bearing member 11. The scroll-type compression mechanism 2 is configured by sandwiching the orbiting scroll 13 that meshes with the fixed scroll 12 between the fixed scroll 12 and the rotation of the orbiting scroll 13 between the orbiting scroll 13 and the main bearing member 11. Then, a rotation restraint mechanism 14 such as an Oldham ring that guides the circular scroll to move is provided, and the orbiting scroll 13 is eccentrically driven by the eccentric shaft portion 4 a at the upper end of the crankshaft 4, whereby the orbiting scroll 13 is circularly orbited. As a result, the compression chamber 15 formed between the fixed scroll 12 and the orbiting scroll 13 moves from the outer peripheral side to the center portion. Utilizing this, the refrigerant gas is sucked and compressed from the suction pipe 16 leading to the outside of the sealed container 1 and the suction port 17 on the outer peripheral portion of the fixed scroll 12, and the refrigerant gas having a predetermined pressure or higher is compressed. The reed valve 19 is pushed open from the discharge port 18 at the center of the fixed scroll 12 and discharged into the sealed container 1 repeatedly.

  The wrap tip 13c of the orbiting scroll 13 is gradually increased in height from the winding start portion which is the central portion to the winding end portion which is the outer peripheral portion based on the result of measuring the temperature distribution during operation. Is provided with a slope shape. Thereby, the dimensional change by thermal expansion can be absorbed and local sliding can be prevented.

  Further, the orbiting scroll back surface 13e has an annular seal member 78 disposed on the main bearing member 11, and the seal member 78 performs an orbiting motion so that the high pressure region 30 that is the inner region of the seal member 78 and the outer region. And a back pressure chamber 29 set at a low pressure or an intermediate pressure. By applying pressure on the back surface 13e, the orbiting scroll 13 is stably pressed against the fixed scroll 12, and leakage can be reduced and the circular orbit motion can be stably performed.

  Further, the fixed scroll 12 is provided with a back pressure adjusting mechanism 9 for controlling the back pressure chamber 29 on the back surface 13e of the orbiting scroll 13 so as to always have a constant pressure.

During operation of the compressor, a pump 25 is provided at the other downward end of the crankshaft 4 and is driven simultaneously with the scroll compressor. As a result, the pump 25 sucks up the oil 6 in the oil reservoir 20 provided at the bottom of the hermetic container 1 and supplies it to the compression mechanism 2 through the oil supply hole 26 extending vertically through the crankshaft 4. The supply pressure at this time is substantially equal to the discharge pressure of the scroll compressor, and also serves as a back pressure source for the orbiting scroll 13. As a result, the orbiting scroll 13 does not move away from the fixed scroll 12 and does not come into contact with each other, and the predetermined compression function is stably exhibited.

  A part of the oil 6 supplied in this way is obtained by a supply pressure or its own weight so as to obtain a clearance, between the fitting portion between the eccentric shaft portion 4a and the orbiting scroll 13, and between the crankshaft 4 and the main bearing member 11. Then, the oil enters the bearing portion 66, lubricates the respective portions, falls, and returns to the oil sump 20. Another part of the oil 6 supplied to the high-pressure region 30 passes through an oil supply passage 54 having an opening in the high-pressure region 30, is around the outer peripheral portion of the orbiting scroll 13, and the rotation restraint mechanism 14 is located. Along with entering the pressure chamber 29 and lubricating the thrust sliding portion and the sliding portion of the rotation restraining mechanism 14, the back pressure of the orbiting scroll 13 is applied in the back pressure chamber 29.

  The back pressure chamber 29 is sealed between the high pressure region 30 and the high pressure side by an annular sealing member 78, and the pressure increases as the incoming oil fills up. 9 acts to return and enter the suction portion of the compression chamber 15.

  The approach of the oil 6 is repeated at a predetermined cycle, and the timing of this repetition is determined by a combination of the relationship between the repeated cycle of suction, compression, and discharge and the pressure setting in the back pressure adjusting mechanism 9, Intentional lubrication of the sliding portion with the scroll 13 is achieved. This intentional lubrication is always guaranteed by the back pressure adjusting mechanism 9 opening the recess 10a of the communication path 10 as described above. The oil 6 supplied to the suction port 17 moves to the compression chamber 15 along with the orbiting motion of the orbiting scroll 13 and serves to prevent leakage between the compression chambers 15.

  As shown in FIG. 3, in the scroll compressor of the present embodiment, the operation is performed in a state where it is pressed against the fixed scroll 12 by applying a back pressure to the orbiting scroll 13, but this is continued stably. Therefore, the height of the wrap 13b of the orbiting scroll 13 is formed lower than the height of the wrap 12b of the fixed scroll 12. Thereby, the frictional force due to sliding acts between the lap bottom surface 13 d of the orbiting scroll 13 and the lap top surface 12 c of the fixed scroll 12. Further, a slope is formed on the lap bottom surface 13d of the orbiting scroll 13 so that the groove bottom surface gradually becomes deeper from the outer periphery toward the center, so that the end plate 13a of the orbiting scroll 13 and the portion 12f on the outer peripheral surface of the fixed scroll 12 are brought into contact with each other. I am letting. That is, the distance between the power points acting on the orbiting scroll 13 is reduced in the axial direction, and the power point is moved to the outer peripheral portion in the radial direction, thereby stabilizing the orbiting motion of the orbiting scroll 13.

  During operation, a back pressure is applied to the orbiting scroll back surface 13e, and a high pressure is applied to the inner side of the annular seal member 78, and a suction pressure or a predetermined intermediate pressure is applied to the outer back pressure chamber 29. Thus, the orbiting scroll 13 is pressed against the fixed scroll 12 in a warped state. If the end plate 13a has a constant thickness, the orbiting scroll 13 is greatly warped, and a gap is generated between the outer peripheral portion of the end plate 13a and the outer peripheral surface portion 12f of the fixed scroll 12, and the back pressure chamber 29 is compressed. If the chamber 15 communicates, there is a risk of causing a decrease in capacity. Further, local contact between the orbiting scroll 13 and the fixed scroll 12 may occur, leading to an increase in input and further seizure.

Therefore, in the scroll compressor of the present invention, a gap is provided between the wrap tip 13c of the orbiting scroll 13 and the lap groove bottom surface 12d of the fixed scroll 12, and the thickness of the end plate 13a of the orbiting scroll 13 is set to the outer peripheral portion 13o, the intermediate portion 13m, and the boss. The seal member 78 is disposed on the orbiting scroll back surface 13e corresponding to the intermediate portion 13i, and the rotation restraining mechanism 14 is disposed on the orbiting scroll back surface 13e corresponding to the outer periphery portion 13o. Since the pressure applied across the seal member 78 is different, pressure deformation can be suppressed by changing the thickness of the end plate 13a of the orbiting scroll 13 in accordance with the applied pressure. As a result, it is possible to operate without generating a gap between the outer peripheral portion of the end plate 13a of the orbiting scroll 13 and the portion 12f of the outer peripheral surface of the fixed scroll 12, and the communication between the back pressure chamber 29 and the compression chamber 15 is prevented. With this, high efficiency can be achieved. Further, local contact between the orbiting scroll 13 and the fixed scroll 12 can be prevented, and the risk of sudden increase in input and seizure can be eliminated. That is, it is possible to provide a scroll compressor that achieves high efficiency and high reliability.

  Further, the rotation restraint mechanism 14 is constituted by an Oldham ring, and the difference in thickness between the intermediate portion 13m and the outer peripheral portion 13o is made larger than the thickness 14h excluding the key portion of the Oldham ring. In this configuration, it is possible to suppress the pressure deformation of the orbiting scroll 13 to the maximum while maintaining the axial size of the compression mechanism portion, thereby preventing local contact and leading to rapid increase in input and seizure. The fear can be resolved.

  In addition, under conditions where the discharge temperature of the working fluid is high, such as during an overload, the wrap 12b of the fixed scroll 12 has a larger amount of thermal expansion at the center than at the outer peripheral portion. May cause. As a countermeasure, there is a method of further expanding the slope formed on the bottom surface 13d of the lap groove of the orbiting scroll 13, but the slope becomes a gap under a low discharge temperature condition, which causes a decrease in performance. Therefore, the thickness of the boss inner peripheral portion 13i is made the thinnest in the end plate 13a. As a result, the end plate 13a of the boss inner peripheral portion 13i of the orbiting scroll 13 is flexibly deformed and absorbs the thermal expansion of the wrap 12b of the fixed scroll 12. Therefore, local contact can be achieved without increasing the slope of the wrap groove bottom surface 13d. Can be prevented and at the same time higher efficiency can be achieved.

(Embodiment 2)
FIG. 4 is a cross-sectional view showing the orbiting scroll 13 of the compression mechanism portion of the scroll compressor according to the second embodiment of the present invention. 4, the same components as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 4, the thickness of the end plate 13a of the intermediate portion 13m is made the same as that of the boss portion 13g. Thereby, since the boss portion 13g has a thick structure, there is no worry of stress concentration at the root portion, and the reliability of the orbiting scroll 13 can be improved.

  Finally, when the working fluid is a high-pressure refrigerant, such as carbon dioxide, the difference between the high and low pressures is particularly large, and the load applied to the orbiting scroll back surface 13e is also increased. It is possible to realize a scroll compressor that achieves both high performance and high reliability.

  As described above, the scroll compressor according to the present invention is operated with the orbiting scroll in contact with the fixed scroll, thereby suppressing leakage, and at the same time, the wrap height relationship between the orbiting scroll and the fixed scroll and the orbiting scroll. By restricting the thickness of the end plate, it is possible to prevent local contact. Therefore, the working fluid is not limited to the refrigerant, and the scroll fluid machine such as an air scroll compressor, a vacuum pump, or a scroll type expander is used. It can also be applied to applications.

The longitudinal cross-sectional view of the scroll compressor in Embodiment 1 of this invention The principal part expanded sectional view of the compression mechanism part of the scroll compressor in Embodiment 1 of this invention Detailed sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 1 of this invention Detailed sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 2 of this invention Sectional view of the compression mechanism of a conventional scroll compressor

Explanation of symbols

12 fixed scroll 12b wrap 12d lap groove bottom surface 12f outer peripheral surface portion 13 orbiting scroll 13a end plate 13b wrap 13c lap tip 13d lap groove bottom surface 13g boss portion 13i boss inner peripheral portion 13m intermediate portion 13o outer peripheral portion 14 rotation restraint mechanism 15 compression chamber 29 Back pressure chamber 30 High pressure region 78 Seal member

Claims (5)

A compression scroll is formed between the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate, and an annular seal member is disposed on the back of the orbiting scroll. The orbiting scroll is divided into a back pressure chamber, the orbiting scroll is brought into contact with the fixed scroll by applying a suction pressure or a fixed intermediate pressure to the back pressure chamber, and a rotation restraining mechanism is provided on the back of the orbiting scroll, In the scroll compressor in which the scroll is swung along a circular trajectory, and the compression chamber moves toward the center while changing the volume, and performs a series of operations of suction, compression, and discharge.
A gap is provided between the wrap tip of the orbiting scroll and the bottom surface of the wrap groove of the fixed scroll, and the end plate thickness of the orbiting scroll is formed to be different between the outer peripheral part, the intermediate part, and the inner peripheral part of the boss, and the orbiting corresponding to the intermediate part The scroll compressor which arrange | positions the said sealing member on the scroll back surface, and arrange | positions the said rotation restraint mechanism in the said turning scroll back surface which corresponds to the said outer peripheral part. The scroll compressor according to claim 1, wherein the rotation restraint mechanism is configured by an Oldham ring, and a difference in thickness between the intermediate portion and the outer peripheral portion is made larger than a thickness excluding the key portion of the Oldham ring. The scroll compressor according to claim 1 or 2, wherein the end plate thickness of the inner peripheral portion of the boss is made the thinnest. The scroll compressor according to any one of claims 1 to 3, wherein the end plate thickness of the intermediate portion is the same as that of the boss portion. The scroll compressor according to any one of claims 1 to 4, wherein the working fluid is a high-pressure refrigerant, for example, carbon dioxide.