JP2008002430A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor for achieving high reliability and high efficiency from the initial stage of operation by taking into consideration the pressure deformation of a fixed scroll and a turning scroll in a scroll compressor, accompanied by the requirement of the high efficiency of a refrigerating air-conditioning apparatus in recent years and the application of a high pressure refrigerant such as a carbon dioxide. <P>SOLUTION: An inclined face is formed on the lap part tip 12d of the fixed scroll 12 for reducing the lap height to the inner peripheral side from the outer peripheral side toward the turning scroll 13 so that a clearance in the thrust direction between the bottom 13c of an end plate 13a of the turning scroll 13 and the lap part tip 12d of the fixed scroll 12 increases toward the inner peripheral side from the outer peripheral side. An inclination is also arranged on the lap part tip 12d of the fixed scroll 12 so as to reduce to the inner peripheral side from the outer peripheral side in the radial direction of a lap. <P>COPYRIGHT: (C)2008,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 is adjusted to the maximum. 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. 4 is a cross-sectional view of the orbiting scroll of the conventional scroll compressor described in Patent Document 1. As shown in FIG. 4, the lap portion tip 13d of the orbiting scroll 13 has an inner peripheral side flat surface 13e and an outer peripheral side 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. However, 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 taken into consideration.

  Due to the pressure difference between the discharge pressure and the suction pressure, the orbiting scroll is deformed to the fixed scroll side, and the contact surface pressure increases due to the contact between the bottom of the end plate of the orbiting scroll and the tip of the wrap section of the fixed scroll, causing galling. As a result, the compression efficiency and durability of the compressor are reduced. In addition, when the bottom of the end plate of the orbiting scroll is deformed to the front end of the fixed scroll lap due to the differential pressure between the discharge pressure and the suction pressure, the front end of the end of the orbiting scroll comes into contact with the bottom of the end plate of the fixed scroll. However, there is a problem that durability is lowered due to a sudden increase in input and generation of galling due to a single contact.

  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.

  Therefore, the present invention has been made in view of the above-described conventional problems, and considering the pressure deformation of the orbiting scroll due to the differential pressure between the discharge pressure and the suction pressure, scroll compression that realizes high reliability and high efficiency from the beginning of operation. The purpose is to provide a machine.

  In order to solve the above-described conventional problems, in the scroll compressor of the present invention, the thrust direction gap between the bottom of the orbiting scroll and the tip of the wrap portion of the fixed scroll is from the outer peripheral side to the inner peripheral side of the wrap curve. The tip of the wrap portion of the fixed scroll or the orbiting scroll is formed so as to increase the inclination and to increase the inclination in the radial direction of the wrap so as to decrease from the outer peripheral side to the inner peripheral side.

  As a result, even when pressure deformation occurs due to the differential pressure between the discharge pressure and the suction pressure, the tooth bottom of the orbiting scroll end plate and the tip of the fixed scroll wrap portion or the end of the orbiting scroll wrap portion and the end of the fixed scroll end plate The object is to achieve high reliability and high efficiency from the initial operation because the bottom does not come into contact with each other and contacts uniformly.

  The scroll compressor according to the present invention optimizes the shapes of the orbiting scroll and the fixed scroll, so that the bottom of the orbiting scroll end plate and the fixed scroll wrap end, and the orbiting scroll end and fixed scroll end plate are fixed. The tooth bottom can be contacted uniformly, and high reliability and high efficiency can be realized from the initial operation.

  The first invention provides an inclination so that the thrust direction gap between the bottom of the orbiting scroll and the tip of the wrap portion of the fixed scroll increases from the outer peripheral side to the inner peripheral side of the wrap curve, and the wrap The tip end of the wrap portion of the fixed scroll is formed so as to be inclined so as to decrease in the radial direction from the outer peripheral side to the inner peripheral side.

  As a result, even when pressure deformation due to the differential pressure between the discharge pressure and suction pressure occurs, the bottom of the end plate of the orbiting scroll and the tip of the wrap section of the fixed scroll do not come into contact with each other, making contact evenly. And high efficiency from the initial operation.

  According to a second aspect of the present invention, an inclination is provided so that a thrust direction gap between the tip of the wrap portion of the orbiting scroll and the bottom of the fixed scroll increases from the outer peripheral side to the inner peripheral side of the wrap curve, and the wrap The tip of the wrap portion of the orbiting scroll is formed so as to be inclined so as to decrease in the radial direction from the outer peripheral side to the inner peripheral side.

  As a result, even when pressure deformation due to the differential pressure between the discharge pressure and the suction pressure occurs, the wrap portion tip of the orbiting scroll has a shape that takes into account temperature distortion or pressure deformation. The tip of the part and the bottom of the fixed scroll do not come into contact with each other and contact uniformly, and high reliability and high efficiency can be realized from the initial operation.

  In the third invention, in particular, the orbiting scroll of the first and second inventions is subjected to surface treatment with an alumite film treatment, PVD treatment, or nickel phosphorous plating treatment as surface treatment, thereby causing abnormal wear due to surface treatment with a hardened layer. It is possible to drive without causing seizure. In addition, even in transient operation where the return of the liquid refrigerant is severe in a system with a large capacity and multiple refrigerants, the liquid refrigerant ensures high reliability without seizure even if the lubricating oil runs out or the temperature rises on the thrust surface of the orbiting scroll. Can be secured. In addition, it is possible to avoid the sudden increase in input due to the local hit unique to the hardened layer in the first and second inventions.

  In the fourth invention, the refrigerant of the first to third inventions is a high-pressure refrigerant, for example, carbon dioxide. Accordingly, even when a high differential pressure is generated, according to the first to third aspects, galling and abnormal wear can be effectively prevented even if the bottom of the end plate of the orbiting scroll is deformed by pressure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(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 a 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 according to 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 the rotation of the orbiting scroll 13 between the orbiting scroll 13 and the main bearing member 11 is prevented. 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 4a at the upper end of the crankshaft 4, thereby causing the orbiting scroll 13 to move in a circular orbit. Thereby, 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 center 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 leave the fixed scroll 12 and stably exhibits a predetermined compression function.

  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. 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.

Further, the oil 6 entering the back pressure space 29 flows through a throttle hole 57 provided in a part of the communication path 54.
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. 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 is determined by a 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.

  In addition, as shown in FIG. 2, the thrust direction gap between the tooth bottom 13 c of the end plate 13 a of the orbiting scroll 13 and the tip 12 d of the wrap portion of the fixed scroll 12 increases from the outer peripheral side to the inner peripheral side at room temperature. Furthermore, an inclined surface is formed on the wrap portion tip 12d of the fixed scroll 12 so that the wrap height decreases from the outer peripheral side to the inner peripheral side with respect to the orbiting scroll 13, and the wrap portion front end 12d of the fixed scroll 12 In addition, an inclination is provided so as to decrease from the outer peripheral side to the inner peripheral side in the radial direction of the wrap.

  With the above configuration, even when pressure deformation occurs due to the differential pressure between the discharge pressure and the suction pressure, the bottom 13c of the end plate 13a of the orbiting scroll 13 and the tip 12d of the wrap portion of the fixed scroll 12 do not come into contact with each other and are uniform. Because of the contact, high reliability and high efficiency can be realized from the initial operation.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the compression element of the scroll compressor according to the second embodiment of the present invention. As shown in the figure, the swivel so that the thrust direction gap between the bottom 12c of the end plate 12a of the fixed scroll 12 and the lap portion tip 13d of the orbiting scroll 13 increases from the outer peripheral side to the inner peripheral side at room temperature. An inclined surface is formed at the wrap portion tip 13d of the scroll 13 so that the wrap height decreases from the outer peripheral side to the inner peripheral side with respect to the fixed scroll 12, and the wrap portion 13d of the orbiting scroll 13 is wrapped. An inclination is provided so as to decrease in the radial direction from the outer peripheral side to the inner peripheral side.

  With the above configuration, even when pressure deformation due to the differential pressure between the discharge pressure and the suction pressure occurs, the wrap portion tip 13d of the orbiting scroll 13 has a shape that takes into account pressure deformation and temperature distortion. The tip 13d of the wrap portion 13 of the scroll 13 and the tooth bottom 12c of the end plate 12a of the fixed scroll 12 do not come into contact with each other and contact uniformly, and high reliability and high efficiency can be realized from the initial operation.

(Embodiment 3)
The fixed scroll 12 is made of an iron-based material, and the orbiting scroll 13 has a surface treatment applied to an aluminum-based material, and a hardened layer is formed on the surface thereof. As this surface treatment, an alumite film treatment, PVD treatment, nickel phosphorus plating treatment, etc. are performed (not shown).

With the above configuration, the discharge pressure of the compressor is high, and when the back scroll 13 is applied with a back pressure not to be pulled away from the fixed scroll 12, the orbiting scroll 13 is strongly pressed against the fixed scroll 12. The hardened layer formed by the surface treatment can provide a more reliable scroll compressor without seizing. Also, in a system with a large capacity and a large number of refrigerants, a severe liquid return to the scroll compressor occurs during transient operations such as starting and defrosting, and this liquid return causes the lubricating oil to be washed with the liquid refrigerant, resulting in severe lubrication. However, it is not seized by the hardened layer by this surface treatment, and high speed operation is possible.

(Embodiment 4)
In the scroll compressor according to the fourth embodiment of the present invention, the refrigerant is a high-pressure refrigerant, for example, carbon dioxide (not shown).

  When the refrigerant is a high-pressure refrigerant, for example, carbon dioxide, 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 refrigeration cycle of the conventional HFC refrigerant. However, in the present invention, the temperature distortion and pressure deformation of the orbiting scroll 13 and the fixed scroll 12 are taken into consideration, and there is no local contact and the surface pressure is uniform. Therefore, a highly reliable and highly efficient scroll compressor can be realized from the beginning of operation.

  As described above, the scroll compressor according to the present invention can achieve high reliability and high efficiency by optimizing the shapes of the orbiting scroll and the fixed scroll, and the air scroll compression is not limited to the working fluid as the refrigerant. The present invention can also be applied to the use of scroll fluid machines such as compressors, vacuum pumps, oil-free compressors, and scroll type expanders.

The longitudinal cross-sectional view of the scroll compressor in Embodiment 1 of this invention Element expanded sectional view of the compression mechanism part of the scroll compressor in Embodiment 1 of this invention Element expanded sectional view of the compression mechanism part of the scroll compressor in Embodiment 2 of the present invention Sectional view of the orbiting scroll of a conventional scroll compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Fixed scroll 12a End plate 12b Spiral wrap 12c Tooth bottom 12d Lapping part tip 13 Orbiting scroll 13a End plate 13b Spiral wrap 13c Tooth bottom 13d Lapping part tip 15 Compression chamber

Claims (4)

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, In a scroll compressor forming a compression chamber for discharging, a thrust direction gap between the bottom of the orbiting scroll and the tip of the wrap portion of the fixed scroll increases from the outer peripheral side to the inner peripheral side of the wrap curve. The scroll compressor is characterized in that the tip end of the wrap portion of the fixed scroll is formed so as to be inclined and to be inclined so as to decrease in the radial direction of the wrap from the outer peripheral side to the inner peripheral side. 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, In a scroll compressor that forms a compression chamber for discharging, a thrust direction gap between the tip of the wrap portion of the orbiting scroll and the bottom of the fixed scroll increases from the outer peripheral side to the inner peripheral side of the wrap curve. The scroll compressor is characterized in that the tip of the wrap portion of the orbiting scroll is formed so as to be inclined and to be inclined so as to decrease in the radial direction of the lap from the outer peripheral side to the inner peripheral side. 3. The scroll compressor according to claim 1, wherein the orbiting scroll is subjected to any one of alumite film treatment, PVD treatment, and nickel phosphorus plating treatment as a surface treatment. 4. The scroll compressor according to claim 1, wherein the refrigerant is a high-pressure refrigerant, for example, carbon dioxide.

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