JP2010096016A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine capable of preventing the separation of a movable scroll from a fixed scroll and reducing power consumption. <P>SOLUTION: The scroll fluid machine includes a back pressure applying mechanism increasing pressure in a space housing a movable base plate (40a) so as to generate a force pressing the movable scroll (40) against the fixed scroll, and a back pressure increasing mechanism increasing a force pressing the movable scroll (40) against the fixed scroll. The back pressure increasing mechanism includes a recess (68) formed in a region slidingly contacting with a seal wall of the fixed scroll in the movable base plate (40a). The recess (68) communicates with the outer end of a swirl-shape groove of the fixed scroll. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine.

For example, a scroll compressor used for compressing a working fluid such as a refrigerant includes an asymmetric scroll compressor in which a fixed scroll has a spiral groove.
The spiral groove of the fixed scroll accommodates the spiral wall of the movable scroll so as to be rotatable, and the spiral groove is partitioned into a plurality of pressure chambers. In the case of a scroll compressor, the pressure chamber moves from the outer end to the inner end of the spiral groove while the volume of the pressure chamber decreases with the orbiting movement of the movable scroll. The working fluid is sucked into the pressure chamber in the outer end region of the spiral groove and is compressed during the movement of the pressure chamber. The compressed working fluid is discharged from the pressure chamber in the inner end region of the spiral wall. The discharged working fluid is supplied to the outside after the lubricating oil contained therein is separated.

Some scroll type fluid machines have a mechanism for increasing the pressure (back pressure) of the space in which the movable scroll substrate is accommodated in order to press the movable scroll against the fixed scroll. This mechanism uses the separated lubricating oil to increase the pressure in the space (see, for example, Patent Document 1).
According to the scroll compressor disclosed in Patent Document 1, oil is supplied to the back pressure chamber at a supply pressure equivalent to the discharge pressure. Thereby, it is thought that separation of the turning scroll from the fixed scroll is suppressed.

Moreover, according to the scroll compressor which patent document 1 discloses, the recessed part connected to an inlet is formed in the fixed scroll. According to Patent Document 1, the back pressure is increased by the low suction pressure acting on the recess. This is also considered to suppress the separation of the orbiting scroll from the fixed scroll.
International Publication No. WO2005 / 038254 pamphlet (eg, page 6, lines 22-31, page 7, lines 12-18, see FIG. 1)

On the other hand, the scroll type fluid machine is desired to reduce power consumption in addition to suppressing the separation of the movable scroll from the fixed scroll.
Moreover, in order to suppress the deformation | transformation by the heat | fever of a movable scroll and to improve a sliding characteristic, the heat dissipation improvement of a movable scroll is also desired.
Further, when the concave portion is formed in the fixed scroll, flash is generated, and there is a possibility that the sliding characteristics between the fixed scroll and the movable scroll are adversely affected. In addition, some fixed scrolls have a manganese phosphate treatment on the surface of a base material made of steel. However, when the recesses are formed on the base material and then the manganese phosphate treatment is applied, the shape of the recesses varies. End up.

The present invention has been made based on the above-described circumstances, and one of its purposes is to provide a scroll type fluid machine in which the movable scroll is prevented from being separated from the fixed scroll and the power consumption is reduced.
One of the objects of the present invention is to provide a scroll type fluid machine that prevents the movable scroll from being separated from the fixed scroll and has improved sliding characteristics.

  One of the objects of the present invention is to provide a high-quality scroll-type fluid machine in which the movable scroll is prevented from being separated from the fixed scroll and the variation in the shape of the recess is suppressed.

  In order to achieve the above object, according to one aspect of the present invention, a spiral substrate is disposed in a case, and a spiral groove is formed together with the fixed spiral wall and the fixed spiral wall by surrounding the fixed spiral wall. A fixed scroll having a partition wall for partitioning, a movable substrate in sliding contact with the fixed spiral wall and a tip of the seal wall, and a movable spiral wall, and a plurality of pressure chambers in the groove in cooperation with the fixed scroll A movable scroll that divides into the fixed scroll, a first communication path that is formed in the fixed scroll and communicates the inner end region of the groove and the outside of the fixed scroll, and is formed in the fixed scroll, and the outer end region of the groove and the A second communication path that communicates with the outside of the fixed scroll, and a space that is joined to the fixed scroll and that accommodates the movable substrate in a rotatable manner in cooperation with the fixed scroll. A support frame, a drive shaft that penetrates the support frame, a turning mechanism for turning the movable scroll with respect to the fixed scroll, and a force for pressing the movable scroll against the fixed scroll A back pressure applying mechanism for increasing the pressure in the space; and a back pressure increasing mechanism for increasing a force for pressing the movable scroll against the fixed scroll. The back pressure increasing mechanism is provided on the movable substrate. A scroll type fluid machine is provided that includes a recess formed in a region slidably contacting the seal wall and communicating with an outer end region of the groove.

Preferably, the movable scroll is made of an alloy containing aluminum, and the fixed scroll is made of an alloy containing iron.
Preferably, the movable scroll further has a film containing aluminum oxide on the surface of the movable substrate, and the fixed scroll further has a film formed by manganese phosphate treatment on the surface of the seal wall. 3).

In the scroll type fluid machine according to the first aspect of the present invention, the concave portion is formed in the substrate of the movable scroll. Since the recess communicates with the spiral-shaped groove of the fixed scroll, the force for pressing the movable scroll against the fixed scroll is increased. Moreover, since the recessed part is formed in the movable scroll, weight reduction of the movable scroll is achieved.
As a result, in this scroll type fluid machine, the movable scroll is prevented from being separated from the fixed scroll, and the power consumption is reduced.

In the scroll type fluid machine according to the second aspect, since the movable scroll is made of an alloy containing aluminum, the flash is soft even if the flash is generated when the recess is formed. For this reason, the influence of the flash on the sliding between the movable scroll and the fixed scroll is small.
Moreover, the heat dissipation of the movable scroll is improved by forming the concave portion in the movable scroll. For this reason, even if the material of the movable scroll is an alloy containing aluminum, the temperature rise of the movable scroll due to the sliding between the movable scroll and the fixed scroll is suppressed, and the deformation of the movable spiral wall is suppressed. As a result, the sliding characteristics between the movable scroll and the fixed scroll are improved.

  In the scroll type fluid machine according to the third aspect, since the film of the movable scroll contains aluminum oxide, the dimensional accuracy of the concave portion is higher than that when the concave portion is formed on the fixed scroll. For this reason, this scroll type fluid machine is of high quality.

  FIG. 1 shows a scroll type fluid machine according to an embodiment of the present invention. This scroll type fluid machine is applied to a compressor such as a refrigeration system, an air conditioning system, or a hot water supply system, and compresses a refrigerant or the like as a working fluid. In addition, this scroll type fluid machine can be used as an expander with appropriate modifications. In the following description, a case where a scroll type fluid machine is used as a compressor will be described.

  This scroll type fluid machine includes a housing (closed container) 2. The housing 2 includes a cylindrical portion 4 and an upper lid 6 and a lower lid 8 that are airtightly fitted to the upper end and the lower end of the cylindrical portion 4, respectively. A suction pipe 10 for introducing a working fluid into the housing 2 is connected to the cylindrical portion 4, and a discharge pipe 12 for discharging the working fluid compressed in the housing 2 is connected to the upper lid 6. . The housing 2 is installed so that the vertical direction in the figure matches the vertical direction.

An electric motor 14 is accommodated in the cylindrical portion 4, and the electric motor 14 has a substantially cylindrical stator 14a. The stator 14a is fixed to the cylindrical portion 4, and a substantially columnar rotor 14b is concentrically disposed inside the stator 14a so as to be rotatable.
The rotor 14b is penetrated in the axial direction by the drive shaft 16, and the drive shaft 16 can rotate integrally with the rotor 14b. Accordingly, the drive shaft 16 is rotationally driven by energization of the electric motor 14.

The lower end of the drive shaft 16 reaches the central hole of the partition wall 18. A sleeve 20 with a hook surrounding the lower end of the drive shaft 16 is fixed in the central hole of the partition wall 18, and a slide bearing 22 is inserted between the sleeve 20 and the drive shaft 16.
The partition wall 18 partitions the inside of the housing 2 up and down, and an oil storage chamber 24 that stores lubricating oil is defined between the partition wall 18 and the lower lid 8. Lubricating oil introduction holes 18 a are formed in the partition wall 18, and the lubricating oil adhering to the upper surface of the partition wall 18 flows into the oil storage chamber 24 through the introducing holes 18 a.

An end plate 26 is also fixed to the partition wall 18 so as to close the lower end of the sleeve 20, and an outer rotor 28 a having inner teeth and an inner rotor 28 b having outer teeth are formed in a recess formed in the flange of the sleeve 20. Contained.
The outer rotor 28a is fixed to the outer peripheral surface of the recess, and the inner rotor 28b is fitted to the lower end of the drive shaft 16 so as to be integrally rotatable. That is, the sleeve 20, the end plate 26, the outer rotor 28 a and the inner rotor 28 b constitute a trochoid pump 30, and the sleeve 20 and the end plate 26 constitute a casing of the trochoid pump 30.

The inlet of the trochoid pump 30 opened to the lower surface of the end plate 26 is in communication with the vicinity of the bottom of the oil storage chamber 24 through the nozzle 32 fixed to the partition wall 18, overlooking the oil storage chamber 24. On the other hand, the lower end surface of the drive shaft 16 faces the outlet of the trochoid pump 30 opened on the upper surface of the end plate 26.
The drive shaft 16 is formed with an internal flow path 16 a that passes through the drive shaft 16 in the axial direction, and an inlet of the internal flow path 16 a is open to a lower end surface of the drive shaft 16. For this reason, the internal flow path 16 a communicates with the outlet of the trochoid pump 30. The outlet of the internal flow path 16 a is opened at the upper end surface of the drive shaft 16.

  The upper end portion of the drive shaft 16 is formed into an eccentric shaft 34, and the eccentric shaft 34 is surrounded by a boss 38 via a slide bearing 36. The boss 38 is integrally formed on the back surface of the end plate (movable substrate) 40 a of the movable scroll 40. The eccentric shaft 34, the plain bearing 36, and the boss 38 constitute a turning mechanism for converting the rotational movement of the drive shaft 16 into the turning movement of the movable scroll 40.

The movable scroll 40 is turnably disposed in a space formed between the upper block 42 and the lower block (center frame) 44, and the upper block 42 and the center frame 44 are fixed to the cylindrical portion 4 by welding. ing.
More specifically, the upper end of the center frame (support frame) 44 is formed with a recess for rotatably accommodating the movable substrate 40a, and an intermediate hole 48 for receiving the boss 38 in the center of the bottom surface 46 of the recess. Is open. A shaft hole extends between the bottom surface of the intermediate hole 48 and the lower end of the center frame 44, and a slide bearing 50 is interposed between the shaft hole and the drive shaft 16. Accordingly, the drive shaft 16 is rotatably supported by the housing 2 via the slide bearing 22 and the slide bearing 50.

  The movable substrate 40a and the bottom surface 46 of the recess are opposed to each other with a predetermined gap in the axial direction of the drive shaft 16, and the movable scroll 40 rotates while the movable scroll 40 is turning. An anti-rotation device for preventing the rotation is provided. The rotation prevention device has, for example, a plurality of pins 52, and the roots of the pins 52 are press-fitted into pin holes opened on the back surface of the movable substrate 40a. The distal end portion of each pin 52 is received in a bottomed hole 54 opened in the bottom surface 46 of the recess, and can pivot within the bottomed hole 54.

A seal ring 55 is disposed on the bottom surface 46 of the recess on the inner side of the bottomed hole 54. The recess is partitioned by the seal ring 55 into a region radially inward of the seal ring 55 (high pressure region) and a region radially outward of the seal ring 55 (intermediate pressure region).
The above-described trochoid pump and the internal flow path 16a of the drive shaft 16 constitute a back pressure applying mechanism that generates a back pressure that presses the movable scroll 40 against the fixed scroll 42, and the radial direction of the movable substrate 40a by the seal ring 55. The back pressure at the center increases. The back pressure applying mechanism may employ a pump other than the trochoid pump.

  At the lower end of the upper block 42, a spiral spiral groove 56 is formed to accommodate a spiral spiral wall (movable spiral wall) 40b of the movable scroll 40 so as to be pivotable. A pressure chamber 58 is formed between the two. That is, the upper block 42 has a function as a fixed scroll. Therefore, in the following, the upper block 42 is also referred to as a fixed scroll 42.

Further, the fixed scroll 42 is formed with a discharge hole (first communication passage) 60, and the discharge hole 60 penetrates substantially the center of the fixed scroll 42 in the axial direction. The working fluid compressed in the pressure chamber 58 is discharged from the pressure chamber 58 through the discharge hole 60.
The discharge hole 60 is opened and closed by a reed valve as the discharge valve 62, and the discharge valve 62 is covered with a cover 64. The space in the cover 64 is connected to the vicinity of the partition wall 18 through a predetermined flow path. This flow path is constituted by a downward flow path for the working fluid and the lubricating oil contained in the working fluid formed in the fixed scroll 42, the center frame 44, and the rotor 14b, and a gap between slots in the stator 14a. Yes. An ascending flow path for the working fluid reaching from the partition wall 18 to the upper lid 6, that is, the discharge pipe 12 is formed on the outer periphery of the stator 14 a, the center frame 44, and the fixed scroll 42.

FIG. 2 is a cross-sectional view of the fixed scroll 42 taken along the line II-II in FIG. The fixed scroll 42 is formed with a suction hole (second communication path) 66 that connects the outer end region of the spiral groove 56 when viewed in the spiral direction and the inner end of the suction pipe 10. The opening of the suction hole 66 opens at the bottom surface of the outer end region of the spiral groove 56.
Note that the fixed scroll 42 includes a fixed substrate 42a, a fixed spiral wall 42b, and a seal wall 42c when also referring to FIG. The fixed substrate 42a, the fixed spiral wall 42b, and the seal wall 42c are integrally formed, and the fixed spiral wall 42b and the seal wall 42c are supported by the fixed substrate 42a. The seal wall 42c surrounds the fixed spiral wall 42b, thereby defining the spiral groove 56 together with the fixed spiral wall 42b.

  FIG. 3 is a cross-sectional view of the movable scroll 40 taken along the line III-III in FIG. The movable scroll 40 has a movable substrate 40a and a movable spiral wall 40b that are integral with each other. The movable substrate 40a has a substantially circular shape in plan view, and the tip of the fixed spiral wall 42b and the tip of the seal wall 42c are in sliding contact with the surface of the movable substrate 40a on the movable spiral wall 40b side. Note that the expression that the tip of the fixed spiral wall 42b and the movable substrate 40a are in sliding contact includes the case where they are in sliding contact with a seal member interposed therebetween.

Further, the movable substrate 40a is formed with a recess 68 in a region in sliding contact with the tip of the seal wall 42c as a back pressure increasing mechanism for increasing the back pressure acting on the movable substrate 40a. The recess 68 is a groove extending in a circular arc shape on the outer side of a part of the movable spiral wall 40b when viewed in the radial direction of the movable substrate 40a, and the width of the recess 68 is wide at the center in the longitudinal direction, for example.
One end (communication end) 70 of the recess 68 is separated to some extent from the vicinity of the outer end of the movable spiral wall 40b. The communication end 70 of the recess 68 is positioned at a position where it can always communicate with the outer end region of the spiral groove 56 while the movable scroll 40 is swiveling. In other words, the coolant is supplied to the recess 68 through the outer ends of the suction hole 66 and the spiral groove 56.

In the present embodiment, the portion of the recessed portion 68 other than the communication end 70 does not communicate with the spiral groove 56 while the movable scroll 40 is swiveling. Further, the recess 68 is not in communication with the intermediate pressure region.
In the scroll type fluid machine of the above-described embodiment, when electric power is supplied to the electric motor 14, the rotor 14b and the drive shaft 16 are rotationally driven, and the rotation of the drive shaft 16 is caused by the eccentric shaft 34, the slide bearing. It is converted into a turning motion of the movable scroll 40 by the 36 and the boss 38. While the movable scroll 40 is turning, the rotation movement of the movable scroll 40 is blocked by the rotation blocking device.

  As the movable scroll 40 turns, working fluid containing lubricating oil is sucked into the pressure chamber 58 through the suction pipe 10 and the suction hole 66 in the outer end region of the spiral groove 56. The working fluid is compressed in the pressure chamber 58 and discharged through the discharge hole 60 at the inner end of the spiral groove 56. The discharged working fluid collides with the partition wall 18 and the lubricating oil is separated, and then is discharged to the outside through the discharge pipe 12.

FIG. 4 is a diagram illustrating a turning state of the movable scroll 40 relative to the fixed scroll 42 when viewed from the back of the movable scroll 40. In FIG. 4, for convenience of explanation, the boss 38 is omitted, and the recess 68 is not visible from the back of the movable scroll 40, but the recess 68 is represented by a solid line.
High pressure lubricating oil is supplied to the high pressure region in the recess of the center frame 44. In the intermediate pressure region of the recess, high-pressure lubricating oil leaks through the gap between the seal ring 55 and the movable substrate 40a, and the pressure in the intermediate pressure region is increased to some extent. For this reason, a back pressure that presses the movable scroll 40 against the fixed scroll 42 acts on the movable scroll 40.

In addition, as described above, the recess 68 is always in communication with the outer end of the spiral groove 56 through the communication end 70. When a low-pressure refrigerant is sucked into the outer end region of the spiral groove 56, the pressure in the recess 68 also becomes low. At this time, since the pressure in the recess 68 is lower than the pressure in the high pressure region and the intermediate pressure region, the back pressure is relatively or substantially increased.
As described above, in the scroll type fluid machine described above, since the recess 68 communicates with the spiral groove 56, the force for pressing the movable scroll 40 against the fixed scroll 42 is increased. Moreover, since the recessed part 68 is formed in the movable scroll 40, weight reduction of the movable scroll 40 is achieved.

As a result, in this scroll type fluid machine, separation of the movable scroll 40 from the fixed scroll 42 is prevented, and power consumption is reduced.
The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the scroll type fluid machine of one embodiment is a vertical type, but may be a horizontal type.

  In the scroll type fluid machine of one embodiment, the shape of the recess 68 is not particularly limited as long as the communication end 70 can always communicate with the outer end region of the spiral groove 56. For example, as shown in FIG. 5, a groove having a constant width may be formed as the recess 68. Alternatively, as the recess 68, a groove as wide as possible may be formed as shown in FIG. The width of the recess 68 is preferably larger than the depth.

In the scroll type fluid machine according to the embodiment, the material of the fixed scroll 42 and the movable scroll 40 is not particularly limited, but the fixed scroll 42 is made of a material mainly composed of iron (steel material), and the movable scroll. 40 is preferably made of a material containing aluminum as a main component (aluminum alloy).
In this case, even if a flash occurs in the vicinity of the recess 68 when the recess 68 is formed, the flash is soft. For this reason, the influence of the flash on the sliding between the movable scroll 40 and the fixed scroll 42 is small.

  Further, in this case, the heat dissipation of the movable scroll 40 is improved by forming the recess 68 in the movable scroll 40. For this reason, the temperature rise of the movable scroll 40 by sliding with the movable scroll 40 and the fixed scroll 42 is suppressed, and a deformation | transformation of the movable spiral wall 40b is suppressed. As a result, the sliding characteristics between the movable scroll 40 and the fixed scroll 42 are improved.

On the other hand, as shown in FIG. 7, the fixed scroll 42 may be configured by a base material 72 and a film 74 formed on the surface of the base material 72. You may be comprised with the membrane | film | coat 78 formed in the surface of the base material 76. FIG.
In this case, in the fixed scroll 42, the base material 72 is preferably made of a steel material, and the coating 74 is formed by subjecting the base material 72 to manganese phosphate treatment. In the movable scroll 40, the base material 76 is preferably made of an aluminum alloy, and the coating 78 is preferably made of aluminum oxide formed by subjecting the base material 76 to an alumite treatment.

The film thickness variation of the film 74 formed by the manganese phosphate treatment is about 10 μm, whereas the film thickness variation of the film 78 formed by the alumite treatment is about 3 μm. For this reason, the precision of the shape dimension of the recessed part 68 becomes high, and the quality of a scroll type fluid machine becomes high.
In one embodiment, the communication end 70, which is one end of the recess 68, communicates with the outer end of the spiral groove 56. However, as the movable scroll 40 turns, the other end of the recess 68 is connected to the outer end region of the spiral groove 56. You may make it communicate intermittently. For this purpose, the other end side of the recess 68 may be made longer in FIGS. 3, 5, and 6. By intermittently communicating the other end of the recess 68 with the outer end region of the spiral groove 56, the pressure in the recess 68 is equalized and the wear powder is removed from the recess 68. Thus, the configuration in which the other end of the recess 68 is intermittently communicated with the outer end region of the spiral groove 56 is difficult to realize when the recess is formed in the fixed scroll 42.

When the movable scroll 40 or its base material 76 is made of an aluminum alloy, the depth of the concave portion 68 is set so as not to disappear due to wear, and the width and depth of the concave portion 68 are such that the strength of the movable scroll 40 is high. It is set to ensure enough.
Finally, the scroll type fluid machine according to the present invention can be applied to compression or expansion of various working fluids. However, as a preferable use example, it is used for compression of CO ₂ gas which is more environmentally friendly than the HFC system.

It is a longitudinal section showing a scroll type fluid machine of one embodiment of the present invention. It is sectional drawing of the fixed scroll which follows the II-II line in FIG. It is sectional drawing of the movable scroll which follows the III-III line in FIG. It is a figure for demonstrating turning of the movable scroll with respect to a fixed scroll in the fluid machine of FIG. It is sectional drawing equivalent to FIG. 3 of the movable scroll which concerns on a modification. It is sectional drawing equivalent to FIG. 3 of the movable scroll which concerns on a modification. It is a schematic fragmentary sectional view of a fixed scroll and a movable scroll in the scroll type fluid machine of a modification.

Explanation of symbols

40 movable scroll 40a movable substrate 68 recess (back pressure increasing mechanism)

Claims (3)

A fixed scroll having a seal wall that is disposed in the case and has a fixed wall, a fixed spiral wall, and a spiral wall surrounding the fixed spiral wall to partition a spiral-shaped groove;
A movable substrate in sliding contact with the fixed spiral wall and the tip of the seal wall; and a movable scroll having a movable spiral wall and partitioning the groove into a plurality of pressure chambers in cooperation with the fixed scroll;
A first communication path formed in the fixed scroll and communicating the inner end region of the groove with the outside of the fixed scroll;
A second communication path formed in the fixed scroll and communicating between the outer end region of the groove and the outside of the fixed scroll;
A support frame that is joined to the fixed scroll and that defines a space in which the movable substrate can be swiveled in cooperation with the fixed scroll;
A revolving mechanism for revolving the movable scroll with respect to the fixed scroll, having a drive shaft penetrating the support frame;
A back pressure applying mechanism for increasing the pressure of the space to generate a force to press the movable scroll against the fixed scroll;
A back pressure increasing mechanism that increases a force for pressing the movable scroll against the fixed scroll,
The scroll type fluid machine according to claim 1, wherein the back pressure increasing mechanism includes a recess formed in a region of the movable substrate in sliding contact with the seal wall and communicating with an outer end region of the groove. The movable scroll is made of an alloy containing aluminum,
The scroll type fluid machine according to claim 1, wherein the fixed scroll is made of an alloy containing iron. The movable scroll further has a film containing aluminum oxide on the surface of the movable substrate,
The scroll type fluid machine according to claim 2, wherein the fixed scroll further includes a coating formed on the surface of the seal wall by manganese phosphate treatment.

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