JP2009052465A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the reliability of a fixed scroll and a rotary scroll of a scroll compressor to match the compressor to recent refrigerating air conditioners increased in efficiency and life and using a high-pressure refrigerant such as carbon dioxide. <P>SOLUTION: The thickness H of an end plate of the rotary scroll 13 on the inside of a bearing housing part 13c is 10-35% of the inner diameter D of the bearing housing part 13c. When the scroll compressor is under high load, the tooth bottom of the end plate 13a of the rotary scroll 13 corresponding to the bearing housing part 13c and the winding start part at the lap end 12b of the fixed scroll 12 are deformed, and also the winding start part of the fixed scroll 12 is heated, and thermally expanded to the rotary scroll 13 side. However, since the tooth bottom of the end plate 13a of the rotary scroll 13 on the inside of the bearing housing 13c is flexibly deformed to the end 12b of the fixed scroll 12 by pressure, nonuniform contact does not occur, and the high reliability of the scroll compressor can be realized. <P>COPYRIGHT: (C)2009,JPO&INPIT

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, in the scroll compressor, in order to keep the contact of the sliding surface between the orbiting and fixed end plates in a good state, improve the durability and reduce the leakage loss, about the wrap portion of the orbiting scroll or the fixed scroll, Based on the result of measuring the temperature distribution at the tip of the lap, the height dimension from the root of the end plate to the tip of the lap is adjusted, and in the assembled state, the height between each tip of the lap and the bottom of the other end plate The thrust direction gap that is the largest on the inner peripheral side is formed, or the thrust direction gap is changed in a plurality of stages (for example, see Patent Document 1).

FIG. 5 is a cross-sectional view of the orbiting scroll of the conventional scroll compressor described in Patent Document 1. As shown in FIG. 5, the lap portion tip 13d of the orbiting scroll 13 has an inner peripheral flat surface 13e and an outer peripheral flat surface 13f based on the result of measuring the temperature distribution during operation. The inclined surface between the side flat surface 13e and the outer peripheral side flat surface 13f is used to prevent galling due to the contact of the wrap tip portion 13d due to temperature rise and reduce leakage loss.
Japanese Patent Laid-Open No. 7-197891

  However, in the conventional configuration described in Patent Document 1, each compression chamber formed between the fixed scroll and the orbiting scroll is thermally expanded by the compression heat generated by the compression action. In particular, it is considered that the thermal expansion of the central portion is large, but the deformation of the fixed scroll and the orbiting scroll due to the pressure difference between the discharge pressure and the suction pressure of the compressor is not considered.

  The orbiting scroll is deformed to the fixed scroll side due to the differential pressure between the discharge pressure and the suction pressure, and the rear surface of the orbiting scroll is divided into a high pressure and an intermediate pressure by a sliding partition ring. Since the center part of the end plate corresponding to the housing is thin and high in pressure, the end of the orbiting scroll end plate is deformed by deformation to the fixed scroll side and thermal expansion of the fixed scroll lap center part to the orbiting scroll side. The contact pressure between the bottom and the beginning of the wrap portion of the fixed scroll increases due to contact with each other, and galling occurs between them, reducing the efficiency and durability of the compressor as a compressor.

  In particular, when carbon dioxide is used as the refrigerant, the pressure difference between the discharge pressure of the compressor and the suction pressure is about 7 to 10 times higher than the pressure difference of the refrigeration cycle of the conventional HFC refrigerant. There is a problem that deformation becomes easier to the side, galling occurs at the tooth bottom of the end plate of the orbiting scroll and the tip of the lap portion, and the compressor efficiency and durability as a compressor are reduced.

  In the conventional configuration, the height dimension from the tooth bottom of the end plate to the tip of the wrap is measured based on the result of measuring the temperature distribution at the tip of the wrap during high load operation for the orbiting scroll or fixed scroll. When adjusted, a gap is created at the tip of the lap portion during low-load operation, resulting in a reduction in compressor efficiency.

  Therefore, the present invention has been made in view of the above-described conventional problems, and achieves high reliability even when there is pressure deformation of the orbiting scroll due to the differential pressure between the discharge pressure and the suction pressure at the time of high load. It aims at providing the scroll compressor which implement | achieves high efficiency in a driving | operation area | region.

  In order to solve the above-mentioned conventional problems, in the scroll compressor of the present invention, the thickness of the end plate inside the housing portion of the bearing of the orbiting scroll is 10 to 35% of the inner diameter of the housing portion of the bearing.

  With this configuration, at the time of high load, the orbiting scroll is deformed to the fixed scroll side due to the differential pressure between the discharge pressure and the suction pressure, and in particular, the bottom of the end plate corresponding to the housing portion of the bearing of the orbiting scroll loaded with high pressure. Even if the deformation of the center portion of the wrap portion of the fixed scroll is large, and the wrap center portion of the fixed scroll is thermally expanded to the side of the orbiting scroll due to the high temperature due to the compression heat, the end plate of the housing portion of the orbiting scroll bearing Since the thickness is 10 to 35% of the inner diameter of the housing portion of the bearing, the bottom of the end plate of the orbiting scroll is flexibly deformed to the tip end side of the fixed scroll while maintaining the rigidity of the orbiting scroll. And high reliability can be realized.

  The scroll compressor according to the present invention corresponds to the housing portion of the end plate of the orbiting scroll that is relatively slid while maintaining the rigidity of the orbiting scroll even during high load operation where the pressure difference between the discharge pressure and the suction pressure is high. High reliability can be realized at the center part and the fixed scroll wrap end.

  In the first invention, the thickness of the end plate inside the housing portion of the bearing of the orbiting scroll is 10 to 35% of the inner diameter of the housing portion of the bearing.

  By making the thickness of the end plate inside the housing part of the bearing of the orbiting scroll 35% or less of the inner diameter of the housing part of the bearing, the orbiting scroll is fixed to the fixed scroll side due to the differential pressure between the discharge pressure and the suction pressure at high load. In particular, the deformation of the center of the end of the end plate corresponding to the housing portion of the bearing of the orbiting scroll loaded with high pressure and the tip of the wrap portion of the fixed scroll is large, and the lap center portion of the fixed scroll is compressed heat. Even if the temperature expands due to higher temperatures, the bottom of the orbiting scroll end plate flexibly deforms to the tip end of the fixed scroll lap, so it does not come into contact with each other, achieving high reliability. it can. In addition, the thickness of the end plate inside the housing part of the bearing of the orbiting scroll is 10% or more of the inner diameter of the housing part of the bearing, so that sufficient rigidity is secured against the stress generated on the end plate of the orbiting scroll at high loads. Therefore, high reliability can be realized.

  The second invention is particularly the first invention, in which the thickness of the end plate in the housing portion of the bearing of the orbiting scroll is reduced in the central direction.

  The wrap tip of the fixed scroll becomes hot at the center and thermally expands toward the orbiting scroll. However, the thickness of the end plate inside the housing portion of the orbiting scroll bearing is reduced in the center direction. The scroll can be deformed by pressure more flexibly toward the fixed scroll side at the center, and high reliability can be realized without hitting the wrap tip of the fixed scroll.

The third invention is the second invention, in particular, in which the bottom surface of the end plate of the orbiting scroll is formed so that the thickness of the end plate inside the housing portion of the bearing of the orbiting scroll becomes smaller in the center direction.

  At the time of high load, the wrap tip of the fixed scroll becomes hot and thermally expands toward the orbiting scroll as it becomes the center, but the thickness of the end plate inside the housing part of the bearing of the orbiting scroll becomes smaller in the center direction. Since the bottom of the end plate of the orbiting scroll is formed, pressure deformation can be performed more flexibly, and high reliability can be realized without hitting the wrap tip of the fixed scroll.

  The fourth aspect of the invention is any one of the first to third aspects of the invention, in which a wrap is formed on the end plate excluding the inside of the housing portion of the bearing of the orbiting scroll.

  As a result, even if the end of the end plate corresponding to the housing portion of the bearing of the orbiting scroll is pressure-deformed to the tip end side of the wrap of the fixed scroll at high load, the orbiting scroll wrap does not exist in the bearing housing portion. High reliability can be realized without abnormally contacting the scroll wrap tip with the bottom of the fixed scroll.

  The fifth invention is any one of the first to fourth inventions, and uses carbon dioxide as the working refrigerant.

  Since the carbon dioxide refrigerant is a high differential pressure refrigerant, an excessive pressing force is generated on the surface on which the end plate of the orbiting scroll and the end plate of the fixed scroll slide. It will cause abnormal wear. In particular, the orbiting scroll is more easily deformed to the fixed scroll side, galling occurs at the bottom of the end plate of the orbiting scroll and the tip of the wrap portion of the fixed scroll, reducing the efficiency and durability of the compressor as a compressor. End up. Also, when carbon dioxide refrigerant is used, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than the pressure difference of the conventional refrigeration cycle using chlorofluorocarbon as a refrigerant. Furthermore, the performance was reduced. According to the first to fifth aspects of the invention, even when there is a pressure deformation of the orbiting scroll due to the differential pressure between the discharge pressure and the suction pressure at high load, high reliability can be realized without hitting. Further, high efficiency can be realized in the entire operation region.

  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 the first embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part of the compression mechanism portion of FIG. The operation and action of the scroll compressor configured as shown in the figure will be described below.

As shown in FIG. 1, the scroll compressor of the present invention includes a main bearing member 11 of a crankshaft 4 fixed by welding or shrink fitting in an airtight container 1, and a fixed bolted 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 scroll 12 and prevents the orbiting scroll 13 from rotating between the orbiting scroll 13 and the main bearing member 11. A rotation restricting mechanism 14 such as an Oldham ring that guides the orbital motion 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, thereby causing the orbiting scroll 13 to move circularly. Thus, the compression chamber 15 formed between the fixed scroll 12 and the orbiting scroll 13 is small while moving from the outer peripheral side to the central portion. The refrigerant gas is sucked and compressed from the suction pipe 16 communicating with the outside of the hermetic container 1 and the suction port 17 on the outer peripheral portion of the fixed scroll 12, and the refrigerant gas exceeding the predetermined pressure is fixed. The reed valve 19 is pushed open from the discharge port 18 at the center of the scroll 12 and discharged into the sealed container 1 repeatedly.

  A sliding partition ring 78 disposed on the main bearing member 11 is provided on the back surface portion of the orbiting scroll 13, and the high pressure portion that is an inner region of the sliding partition ring 78 is formed by the sliding partition ring 78 while performing the orbiting motion. 30 and a back pressure space 29 set to an intermediate pressure of high pressure and low pressure, which is an outer region. By applying pressure on the back surface, the orbiting scroll 13 is stably pressed against the fixed scroll 12, reducing leakage and performing stable circular orbit movement.

  Further, the fixed scroll 12 includes a back pressure adjusting valve 9 that controls the pressure in the back pressure space 29 on the back surface of the orbiting scroll 13.

  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.

  Further, the oil 6 supplied to the high pressure portion 30 enters the back pressure space 29 around the outer peripheral portion of the orbiting scroll 13 where the rotation restricting mechanism 14 is located by the communication passage 54 provided in the orbiting scroll. The back pressure of the orbiting scroll 13 is applied in the back pressure space 29 in addition to lubricating the sliding portion by the meshing of the fixed scroll 12 and the orbiting scroll 13 and the sliding portion of the rotation restricting mechanism 14.

  The oil 6 entering the back pressure space 29 is set to an intermediate pressure that is intermediate between the pressures of the high pressure portion 30 and the low pressure side of the compression chamber 15 by the throttle action of the throttle 57. The back pressure space 29 is sealed between the high pressure portion 30 and the high pressure side by an annular partition ring 78. The pressure increases as the incoming oil is filled, and when the pressure exceeds a predetermined pressure, the back pressure adjusting valve 9 Acts to return to the suction portion of the compression chamber 15 and enter.

  The approach of the oil 6 is repeated at a predetermined cycle, and the timing of this repetition depends on the combination of the repetitive cycle of suction, compression, and discharge and the relationship between the pressure setting by the throttle hole 57 and the pressure setting by the back pressure adjusting mechanism 9. As a result, the sliding of the fixed scroll 12 and the wrap 13b of the orbiting scroll 13 is intentionally lubricated. This intentional lubrication is always ensured by the opening of the communication path 10 into the recess 105 by the back pressure regulating valve 9 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.

  Further, as shown in FIGS. 1 and 2, the thickness H of the end plate inside the housing portion 13 c of the bearing of the orbiting scroll 13 is 10 to 35% of the inner diameter D of the housing portion of the bearing.

By setting the thickness H of the end plate 13a inside the housing portion 13c of the bearing of the orbiting scroll 13 to 35% (0.35 × D) or less of the inner diameter D of the housing portion of the bearing, the discharge pressure and the suction are increased at high load. Due to the pressure difference, the orbiting scroll 13 is deformed to the fixed scroll 12 side, and in particular, the end 13a of the end plate corresponding to the inside of the housing part 13c of the bearing of the orbiting scroll 13 loaded with high pressure and the fixed scroll 12 wrap. Even when the central portion of the top end 12b is greatly deformed, and the central portion of the wrap 12b of the fixed scroll 12 becomes hot due to compression heat and thermally expands toward the orbiting scroll 13 side, the end plate 13a of the orbiting scroll 13 can be flexibly expanded. Since the bottom of the tooth is deformed by pressure toward the wrap tip 12b of the fixed scroll 12, high reliability is achieved without contact with one piece. Kill. Further, by setting the thickness H of the end plate 13a inside the housing portion 13c of the bearing of the orbiting scroll 13 to be 10% (0.10 × D) or more of the inner diameter D of the housing portion of the bearing, the fixed scroll 12 at high load. Since sufficient rigidity can be secured against the stress generated when the tip of the wrap 12b contacts the tooth bottom of the end plate 13a of the orbiting scroll 13, high reliability can be realized.

  In addition, even during low-load operation, the bottom of the end plate 13a of the orbiting scroll 13 is flexibly deformed to the wrap tip 12b side of the fixed scroll 12, so that the compressor efficiency can be improved by reducing leakage loss, resulting in higher efficiency. it can.

(Embodiment 2)
In the scroll compressor according to the second embodiment of the present invention, the thickness H of the end plate 13a inside the housing portion 13c of the bearing of the orbiting scroll 13 is reduced in the center direction. FIG. 3 shows an enlarged cross-sectional view of the main part of the compression mechanism. As a result, the wrap end portion 12b of the fixed scroll 12 becomes hot at the center and thermally expands toward the orbiting scroll 13. However, the thickness H of the end plate inside the housing portion 13c of the bearing of the orbiting scroll 13 is increased in the center direction. Since it is made small, the turning scroll 13 can be deformed by pressure more flexibly toward the fixed scroll 12 at the center portion, and high reliability can be realized without coming into contact with the wrap tip 12b of the fixed scroll 12. .

  Further, as shown in the figure, by forming the bottom surface of the end plate 13a of the orbiting scroll 13 so that the thickness H of the end plate 13a inside the housing portion 13c of the bearing of the orbiting scroll 13 becomes smaller in the center direction, At this time, the wrap tip 12b of the fixed scroll 12 becomes high temperature, and the thermal expansion expands toward the orbiting scroll 13 toward the center. However, the thickness H of the end plate 13a inside the housing portion 13c of the bearing of the orbiting scroll 13 increases in the center direction. Since the bottom of the end plate 13a of the orbiting scroll 13 is formed so as to be smaller, the contact of the orbiting scroll 13 is prevented while preventing the one-side contact in consideration of the shape of the wrap tip 12b of the fixed scroll 12 at the time of thermal expansion. Since the end plate 13a inside the housing portion 13c is pressure-deformed more flexibly, the fixed scroll 1 It is possible to further suppress the contact and wrap tip 12b piece can be realized and high reliability.

(Embodiment 3)
In the scroll compressor according to the third embodiment of the present invention, a wrap 13b is formed on an end plate 13b excluding the housing portion 13c of the bearing of the orbiting scroll 13. FIG. 4 shows a front view of the orbiting scroll 13.

  As a result, even when the bottom of the end plate 13a corresponding to the inside of the housing portion 13c of the bearing of the orbiting scroll 13 is pressure-deformed toward the lap tip 12b side of the fixed scroll 12 under high load, the wrap 13b of the orbiting scroll 13 is Since the wrap tip 13b of the orbiting scroll 13 does not abnormally contact the tooth bottom of the end plate 12a of the fixed scroll 12, high reliability can be realized.

(Embodiment 4)
The scroll compressor according to the fourth embodiment of the present invention uses carbon dioxide as a working refrigerant. Since the carbon dioxide refrigerant is a high differential pressure refrigerant, an excessive pressing force is generated on the surface on which the end plate 13a of the orbiting scroll 13 and the tip of the wrap 12b of the fixed scroll 12 slide, which increases the sliding loss. Or it will cause galling and abnormal wear. In particular, the orbiting scroll 13 is more easily deformed toward the fixed scroll 12, and galling occurs at the bottom of the end plate 13 a of the orbiting scroll 13 and the tip of the wrap 12 b of the fixed scroll 12, so that the compressor efficiency and durability as a compressor are increased. The nature will decline. When carbon dioxide refrigerant is used, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than the pressure difference of the conventional refrigeration cycle using chlorofluorocarbon as a refrigerant. Furthermore, the performance was reduced. According to the first to fifth embodiments of the present invention, even when there is a pressure deformation of the orbiting scroll due to the differential pressure between the discharge pressure and the suction pressure at high load, high reliability can be realized without hitting. Further, high efficiency can be realized in the entire operation region.

  As described above, the scroll compressor according to the present invention can achieve high reliability even under high differential pressure operation, and the air scroll compressor, the vacuum pump, the scroll type expansion can be realized without limiting the working fluid to the refrigerant. It can also be applied to the use of scroll fluid machines such as machines.

The longitudinal cross-sectional view of the scroll compressor in Embodiment 1 of this invention Sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 1 of this invention Sectional drawing of the compression mechanism part of the scroll compressor in Embodiment 2 of this invention The front view of the turning scroll of the scroll compressor in Embodiment 3 of this invention Sectional view of the orbiting scroll of a conventional scroll compressor

Explanation of symbols

6 Oil 11 Main bearing member 12 Fixed scroll 12a End plate 12b Wrap 13 Orbiting scroll 13a End plate 13b Wrap 13c Housing portion 14 Rotation restricting mechanism 15 Compression chamber 17 Suction port 29 Back pressure space 30 High pressure portion 31 High pressure space 78 Sliding partition ring

Claims (5)

By engaging the fixed scroll and the orbiting scroll where the spiral wrap rises from the end plate, and moving the orbiting scroll along a circular orbit under the regulation of rotation, it moves while changing the volume, so that suction, compression, A compression chamber for discharging is formed, and a ring-shaped groove is provided in a bearing member that substantially supports the orbiting scroll and the back side of the end plate, and a high pressure is applied to the bearing member and the central part on the back side of the end plate by lubricating oil. The high pressure portion to be applied and the high pressure portion are partitioned by a ring-shaped sliding partition ring having a joint portion attached to the groove portion, and a predetermined pressure lower than that of the high pressure portion is applied to the outer peripheral portion of the rear surface of the orbiting scroll end plate In the scroll compressor provided with the back pressure space to
The scroll compressor characterized in that the end plate thickness inside the housing portion of the bearing of the orbiting scroll is 10 to 35% of the inner diameter of the housing portion of the bearing. The scroll compressor according to claim 1, wherein the thickness of the end plate inside the housing portion of the bearing of the orbiting scroll is reduced in the center direction. The scroll compressor according to claim 2, wherein the bottom surface of the end plate of the orbiting scroll is formed so that the thickness of the end plate inside the housing portion of the bearing of the orbiting scroll is reduced in the center direction. The scroll compressor according to any one of claims 1 to 3, wherein a wrap is formed on an end plate excluding the inside of a housing portion of the bearing of the orbiting scroll. The scroll compressor according to any one of claims 1 to 4, wherein carbon dioxide is used as a working refrigerant.

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