JP2015078665A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor capable of suppressing tip gap expansion due to thermal and pressure deformation of a turning scroll, and capable of reducing leakage loss of a compression chamber.SOLUTION: A scroll compressor of the present invention includes: a stationary scroll that includes a stationary base plate, and a helical stationary lap built on the stationary base plate; and a turning scroll that includes a turning base plate, and a helical turning lap built on the turning base plate, and that forms, together with the stationary scroll, a compression chamber. A first Oldham keyway and a second Oldham keyway are formed on a surface of the turning base plate opposite to the turning lap. The turning base plate includes an Oldham ring attached to the first Oldham keyway and the second Oldham keyway for preventing rotation of the turning scroll. The turning lap is formed highest in an area higher in an average pressure of the compression chamber if the turning scroll is divided on a line connecting the first Oldham keyway to the second Oldham keyway.

Description

  The present invention relates to a scroll compressor.

  One of the issues in improving the efficiency of scroll compressors is reducing refrigerant leakage in the gaps between the wrap teeth. During actual operation, the wrap is deformed by the heat and pressure of the compressed refrigerant and the tooth tip gap changes, so a design that takes this into account is more desirable. For example, Patent Document 1 states that “a plurality of compression chambers are provided between a fixed scroll in which a spiral wrap portion is erected on an end plate, and is provided so as to be able to swivel against the fixed scroll, and between the wrap portions of the fixed scroll. A scroll-type fluid machine having a swirl scroll with a spiral wrap portion formed thereon, wherein at least one of the orbiting scroll and the fixed scroll has a thrust gap with a counterpart tooth bottom. And the tooth tip of the wrap portion has an inner peripheral side flat surface having a minimum height dimension on the innermost peripheral side, and the inner peripheral side flat surface and the outermost peripheral surface are formed. Disclosed is a scroll type fluid machine characterized in that it is formed as an inclined surface between the two sides.

  According to the scroll compressor disclosed in Patent Document 1, generation of galling or the like on the lap center side that thermally expands at a high temperature is suppressed, and the gap on the tip side of the lap portion is reduced to a lower pressure compression chamber. It is said that the amount of leakage of the compressed fluid can be reduced.

Japanese Patent No. 3046486

  However, in the method of Patent Document 1, although deformation due to heat is considered, the deformation due to pressure is not clearly shown. During actual operation, the pressures in the plurality of compression chambers are different from each other, so that the base plate of the orbiting scroll is deformed due to the non-uniformity. In particular, in the structure in which the Oldham ring keyway is provided on the side opposite to the orbiting scroll, the amount of deformation at that location is large, and the orbiting scroll is deformed so as to separate from the fixed scroll on the side where the thrust pressure on the wrap side is high.

  An object of the present invention is to provide a scroll compressor that suppresses expansion of the tooth tip gap due to heat and pressure deformation of the orbiting scroll and reduces leakage loss of the compression chamber.

  The scroll compressor according to the present invention has a fixed scroll having a fixed base plate and a spiral fixed wrap standing on the fixed base plate, and a fixed scroll having a spiral rotating wrap standing on the rotary base plate and the rotary base plate. A swivel scroll that forms a compression chamber with the scroll, and the swivel base plate has a first Oldham key groove and a second Oldham key groove formed on a surface opposite to the swirl wrap, and the first Oldham key groove and the second Oldham key groove When the orbiting scroll is divided by a line connecting the first Oldham key groove and the second Oldham key groove, the orbiting wrap is installed in the region where the average pressure of the compression chamber is higher. The wrap height is the highest.

  ADVANTAGE OF THE INVENTION According to this invention, the scroll compressor which suppressed the tooth-tip clearance expansion by the heat | fever and pressure deformation of a turning scroll, and reduced the leakage loss of the compression chamber can be provided.

The longitudinal cross-sectional view of the scroll compressor in Example 1 Pressure in each compression chamber in Example 1 Example 1 orbiting scroll wrap and Oldham keyway Deformation of orbiting scroll in Example 1 Tooth gap of orbiting scroll in embodiment 1 Region in which the orbiting scroll tooth gap increases in the first embodiment Wrap tooth tip shape of orbiting scroll in embodiment 1 Wrap tooth tip shape of orbiting scroll in embodiment 2 Wrap tooth tip shape different from FIG. 8 in the second embodiment Wrap tooth tip shape of orbiting scroll in embodiment 3 Example 4 orbiting scroll lap and Oldham keyway Wrap tooth tip shape of orbiting scroll in embodiment 4 Wrap tooth tip shape of orbiting scroll in embodiment 5

  The scroll compressor of the present embodiment has a fixed scroll having a fixed base plate and a spiral fixed wrap standing on the fixed base plate, and a spiral rotary wrap standing on the rotary base plate and the rotary base plate. A swivel scroll that forms a compression chamber with a fixed scroll, and the swivel base plate is formed with a first Oldham key groove and a second Oldham key groove on a surface opposite to the swirl wrap, and a first Oldham key groove and a second Oldham key groove. And an Oldham ring which prevents the rotation of the orbiting scroll, and the orbiting wrap in the region where the average pressure of the compression chamber is higher when the orbiting scroll is divided by a line connecting the first Oldham key groove and the second Oldham key groove. Is formed with the highest lap height. According to the present embodiment, expansion of the tooth tip gap due to heat and pressure deformation of the orbiting scroll can be suppressed, and leakage loss of the compression chamber can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a longitudinal sectional view of a scroll compressor showing a first embodiment of the present invention. The basic operation of the scroll compressor of this embodiment will be described with reference to FIG. The scroll compressor 1 includes a compression mechanism unit 3 having a revolving scroll 6 in which a spiral wrap 6a is erected on a base plate 6b, and a fixed scroll 5 in which a spiral wrap 5c is erected on a base plate 5d. An electric motor 4 that drives the mechanism unit 3 and a sealed container 2 that houses the compression mechanism unit 3 and the electric motor 4 are provided. A compression mechanism unit 3 is disposed in the upper part of the sealed container 2. An electric motor 4 is disposed in the lower part of the sealed container 2. Lubricating oil 13 is stored at the bottom of the sealed container 2.

  The sealed container 2 is configured by welding a lid chamber 2b and a bottom chamber 2c up and down to a cylindrical case 2a. The lid chamber 2b is provided with a suction pipe 2d, and a discharge pipe 2e is provided on the side surface of the case 2a. The inside of the sealed container 2 is a discharge pressure chamber 2f.

  The compression mechanism unit 3 includes a fixed scroll 5 having a spiral wrap 5c on the end plate surface 5f side of the base plate 5d, a revolving scroll 6 having a spiral wrap 6a on the base plate 6b, and a bolt attached to the fixed scroll 5. 8 and a frame 9 that supports the orbiting scroll 6.

  The frame 9 includes a main bearing 9a that rotatably supports the crankshaft 7. An eccentric portion 7 b of the crankshaft 7 is connected to the lower surface side of the orbiting scroll 6.

  An Oldham ring 12 is disposed between the lower surface side of the orbiting scroll 6 and the frame 9. The Oldham ring 12 receives the eccentric rotation of the eccentric portion 7b of the crankshaft 7 and makes a revolving motion without rotating the orbiting scroll 6.

  The electric motor 4 includes a stator 4a and a rotor 4b. The stator 4a is fastened to the sealed container 2 by press-fitting or welding. The rotor 4b is rotatably arranged in the stator 4a. A crankshaft 7 is fixed to the rotor 4b.

  The crankshaft 7 includes a main shaft 7 a and an eccentric portion 7 b and is supported by a main bearing 9 a and a lower bearing 17 provided on the frame 9. The eccentric portion 7 b is formed integrally with the main shaft 7 a of the crankshaft 7 so as to be eccentric, and is fitted to the orbiting bearing 6 c provided on the back surface of the orbiting scroll 6. The crankshaft 7 is driven by the electric motor 4, and the eccentric portion 7b is eccentrically rotated with respect to the main shaft 7a, and the orbiting scroll 6 is orbitally moved. The crankshaft 7 is provided with an oil supply passage 7c that guides the lubricating oil 13 to the main bearing 9a, the lower bearing 17 and the slewing bearing 6c.

  When the orbiting scroll 6 orbits through the crankshaft 7 driven by the electric motor 4, the refrigerant gas flows into the compressor from the suction pipe 2d. The refrigerant gas flowing into the compressor is guided to a compression chamber 11 formed by the orbiting scroll 6 and the fixed scroll 5 through a suction port 5a provided in the fixed scroll 5 shown in FIG.

  A plurality of chambers are formed in the compression chamber 11. FIG. 2 shows the pressures of the plurality of compression chambers 11 from P1 to P5. The relationship between P1 and P5 is P1 ≦ P2 ≦ P3 ≦ P4 ≦ P5, and the pressure becomes higher as the lap center side. The compressed refrigerant gas is discharged to the discharge pressure chamber 2f in the sealed container 2 from the discharge port 5e provided at the approximate center of the base plate 5d of the fixed scroll 5, and flows out from the discharge pipe 2e to the outside.

  Next, the flow of refueling will be described. The lubricating oil 13 stored in the bottom of the hermetic container 2 and in the discharge pressure atmosphere is supplied to the back pressure chamber 16 through the oil supply passage 7 c of the crankshaft 7 due to a differential pressure with the back pressure chamber 16. A part of the dissolved refrigerant is separated from the oil that flows into the back pressure chamber 16 and is decompressed, and the inside of the back pressure chamber 16 is in a mixed state of the refrigerant and the oil. The oil and refrigerant that have flowed into the back pressure chamber 16 finally flow out of the back pressure valve 10 provided in the fixed scroll, and are supplied to the compression chamber 11 to lubricate and seal each gap.

  Next, the problem of the present invention will be described. FIG. 3 shows a view of the orbiting scroll 6 as viewed from the lap 6a side (upper side in FIG. 3) and the back pressure chamber 16 side (lower side in FIG. 3). As shown in FIG. 2, a plurality of compression chambers 11 are formed on the lap 6a side of the orbiting scroll 6, and deformation due to pressure occurs. On the back pressure chamber 16 side of the orbiting scroll 6, the Oldham ring 12 is inserted and two Oldham key grooves 6d and 6e formed in the radial direction are formed. The Oldham key groove 6d is the most part of the base plate 6b. getting thin.

  FIG. 4 shows the pressure deformation of the orbiting scroll 6 in the FF cross section of FIG. The deformation mode is such that the Oldham key groove 6d that is thinnest on the base plate 6b is bent. When the compression chamber 11 is divided into two at the center of the Oldham key groove 6d, the orbiting scroll 6 is pressed against the fixed scroll 5 by the pressure of the back pressure chamber 16 on the side where the lowest pressure P1 compression chamber is formed. On the side where the high pressure P2 and P4 compression chambers are formed, the base plate 6b is deformed toward the back pressure chamber 16, and a gap is formed at the tip of the wrap 6c of the orbiting scroll 6. This is hereinafter referred to as the tooth tip gap.

  FIG. 5 shows a gap between the wrap tooth tips of the orbiting scroll 6 when the above-described deformation occurs. The solid line is the wrap height of the orbiting scroll 6 from the end plate surface 5f, and the broken line is the tooth bottom position of the fixed scroll 5. The horizontal axis indicates the distance along the lap from the beginning of the turning scroll 6. A space surrounded by a solid line and a broken line is a tooth gap. The tooth tip gap is small at the beginning of winding, increases in the section from A to B, and decreases again at the end of winding. The section from A to B in which the tooth tip gap increases becomes a shaded portion in FIG.

  If the tooth tip clearance is large, leakage loss increases and the efficiency of the compressor decreases. In the section from A to B in FIG. 6, the tooth gap is large and leakage increases. Therefore, the compressor efficiency can be improved by reducing the tooth gap. Therefore, in the scroll compressor of the present embodiment, in consideration of the tooth tip gap shown in FIG. 5, when the orbiting scroll is divided by the section from A to B (the line connecting the Oldham key grooves 6d and 6e), the compression chamber In the lap 6a) of the orbiting scroll 6 located on the higher side X, the lap height is configured to be the highest. Since the lap height is the highest in the section from A to B where the tooth tip gap is the largest, the tooth tip gap during actual operation can be reduced and the leakage loss of the compression chamber can be reduced. it can. In addition, since the tooth tip gap becomes the smallest at the start of winding of the wrap 6a, more preferably, the wrap height at the start of winding of the orbiting scroll 6 is made the lowest.

  FIG. 7 is a diagram showing the relationship between the distance from the start of winding of the orbiting scroll 6 along the lap and the lap height in this embodiment. In the present embodiment, the lap height is made highest in the section from A to B where the tooth tip gap becomes the largest, and the wrap height is lowered toward the beginning of winding where the tooth tip gap becomes smaller. By adopting such a configuration, the tooth gap in the section from A to B can be reduced and leakage loss can be reduced, so that the efficiency of the compressor can be improved.

  In addition, such a scroll compressor of the present embodiment can be configured as a refrigeration cycle apparatus formed by sequentially connecting a scroll compressor, a condenser, an expansion valve, and an evaporator with a connecting pipe. Moreover, such a refrigeration cycle apparatus can be applied to apparatuses such as an air conditioner, a heat pump water heater, and a refrigerator.

  A second embodiment of the present invention will be described with reference to FIG. The difference from the first embodiment is that the wrap height at the beginning of the wrap winding is made flat.

  As shown in FIG. 2, in the scroll compressor, the pressure increases as it goes to the center of the wrap rather than the outer periphery of the wrap, and the pressure difference in the tooth tip gap increases. The pressure difference becomes larger at the center of the lap. In the center of the wrap, the loss of leakage can be reduced by pressing the tooth tip of the orbiting scroll 6 against the bottom of the fixed scroll 5 more than the outer periphery of the wrap. Efficiency is improved.

  In Example 2 as described above, by making the wrap height at the beginning of winding flat, leakage at the center of the wrap where the pressure difference in the tooth tip gap increases can be reduced compared to Example 1.

  In addition, FIG. 9 is comprised by the curve with which the inclination which a lap height reduces becomes small, so that it goes to the beginning of winding. Also in this shape, as in FIG. 8, it is possible to reduce the leakage at the center of the wrap where the pressure difference in the tooth tip gap becomes larger than in the first embodiment.

  A third embodiment of the present invention will be described with reference to FIG. As shown in FIG. 5, the wrap tooth gap of the orbiting scroll 6 is small at the beginning of the winding, increases in the section from A to B, and decreases again at the end of the winding. Although the end of the winding is not as much as the start of winding, the tooth tip gap becomes smaller, so that the tooth tip gap in the section from A to B can be made smaller by lowering the wrap height.

  In Example 3, correspondingly, the wrap height is lowered from the section A to B toward the end of the winding. The tooth tip gap in the section from A to B can be reduced by the configuration of the first embodiment, and the compressor efficiency can be further improved.

  A fourth embodiment of the present invention will be described with reference to FIGS. Example 4 is a wrap when the winding end is extended by 360 ° with respect to the wrap shown in Example 1.

  As shown in FIG. 4, the orbiting scroll 6 is deformed by pressure, and the tooth tip gap on the side where the average pressure of the compression chamber 11 is high is increased around the Oldham key groove 6 d of the Oldham ring 12. Similar behavior is exhibited even when the number of turns is increased as in the case of the orbiting scroll 6 shown in FIG.

  If the orbiting scroll 6 of FIG. 11 is demonstrated as an example, the tooth-tip gap | interval of the area from A to B and the area from C to D will become large. In Example 4, as shown in FIG. 12, the lap height is maximized in the section from A to B and the section from C to D, and the lap height in the other sections is lowered (from A to (The maximum value of the lap height in the B section and the section from C to D is set higher than the maximum lap height in the other sections). With such a configuration, even when the number of turns of the orbiting scroll 6 is increased, the tooth tip gap can be reduced, and the compressor efficiency can be improved.

  A fifth embodiment of the present invention will be described with reference to FIG. In Example 1 to Example 4, the wrap height of the orbiting scroll 6 was continuously changed in a slope shape, but as shown in FIG. The same effects as those of the first to fourth embodiments can be obtained.

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Sealed container 2a Case 2b Cover chamber 2c Bottom chamber 2d Suction pipe 2e Discharge pipe 2f Discharge pressure chamber 3 Compression mechanism part 4 Electric motor 4a Stator 4b Rotor 5 Fixed scroll 5a Suction port 5c Lap 5d Base plate 5e Discharge Exit 5f End plate surface 6 Orbiting scroll 6a Wrap 6b Base plate 6c Orbiting bearing 6d Oldham keyway 6e Oldham keyway 7 Crankshaft 7a Main shaft 7b Eccentric part 7c Oil supply passage 8 Bolt 9 Frame 9a Main bearing 10 Back pressure valve 11 Compression chamber 12 Oldham ring 13 Lubrication Oil 16 Back pressure chamber 17 Lower bearing X Side with higher thrust direction average pressure Y Side with lower thrust direction average pressure

Claims (8)

A fixed scroll having a fixed base plate and a spiral fixed wrap standing on the fixed base plate;
A revolving scroll that has a swirl base plate and a spiral revolving wrap standing on the revolving base plate, and that forms a compression chamber with the fixed scroll, and
The swivel base plate is formed with a first Oldham key groove and a second Oldham key groove on a surface opposite to the swirl wrap,
An Oldham ring attached to the first Oldham keyway and the second Oldham keyway to prevent rotation of the orbiting scroll;
When the orbiting scroll is divided by a line connecting the first Oldham key groove and the second Oldham key groove, the wrap height of the orbiting lap is formed highest in the region where the average pressure of the compression chamber is higher. Scroll compressor. In claim 1,
When the orbiting scroll is divided by a line connecting the first Oldham key groove and the second Oldham key groove, in the region where the average pressure of the compression chamber is higher, the wrap height of the orbiting lap is formed highest,
A scroll compressor in which a wrap height decreases toward a winding start direction of the orbiting wrap. In claim 2,
A scroll compressor in which the rate of decrease in lap height decreases as the turning wrap starts. In any one of Claims 1 thru | or 3,
When the orbiting scroll is divided by a line connecting the first Oldham key groove and the second Oldham key groove, in the region where the average pressure of the compression chamber is higher, the wrap height of the orbiting lap is formed highest,
A scroll compressor in which a wrap height decreases toward a winding end direction of the orbiting wrap. In any one of Claims 1 thru | or 4,
A scroll compressor in which the wrap height is constant in a predetermined section from the winding start portion of the orbiting wrap. In any of claims 1 to 5,
The scroll compressor which changed the lap height of the said turning lap continuously. In any of claims 1 to 5,
The scroll compressor which changed the lap height of the turning lap discontinuously by the level difference.   A refrigeration cycle apparatus comprising the scroll compressor according to any one of claims 1 to 7, a condenser, an expansion valve, and an evaporator.