JP2007046582A - Scroll fluid machinery and refrigerating cycle using the fluid machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide scroll fluid machinery in which the end-face of the scroll lap of at least either one of a movable and fixed scrolls is manufactured easily and comparatively in a short time irrespective of being divided in a plurality of regions having different heights in the laps, and further particularly scratching between the movable and fixed scrolls is prevented from occurring. <P>SOLUTION: The scroll fluid machinery comprises the movable and fixed scrolls 48, 50 respectively. Each of the scrolls 48, 50 has a spiral lap 54 formed integrally with the base plate 52. At least either one end face of the spiral laps 54 is divided into first to forth regions 57a-57d of different lap-heights. The end faces of the spiral laps 54 are worked to have four finished surfaces having different distances from the base plate 52, and three finished surfaces are round finished surfaces 82a, 82b, 82c having respectively round contours. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine and a refrigeration cycle using the fluid machine, and more particularly to a scroll type fluid machine used for air-conditioning applications such as vehicles and a refrigeration cycle using the fluid machine.

For example, a scroll compressor used as a compressor of an air conditioning system for vehicles includes a movable and fixed scroll in a housing, and these scrolls perform a series of operations of suction, compression, and discharge of working fluid (refrigerant) between them. Has a compression chamber to perform.
As the movable scroll orbits with respect to the fixed scroll, the compression chamber moves from the radially outer side to the center of the scroll, and the volume of the compression chamber decreases with this movement. That is, when the scroll compressor is in operation, the fluid in the compression chamber is compressed most when the compression chamber is positioned at the center of the movable and fixed scrolls, and the temperature at the center portion of these scrolls is higher than that at the radially outer portion. To rise. For this reason, in the scroll compressor, the central portion of the scroll is largely thermally expanded, and the space between the central portion of the spiral wrap and the opposite substrate (for example, the central portion of the spiral scroll of the movable scroll and the fixed scroll substrate). There was a problem that galling occurred.

Therefore, in the scroll compressor disclosed in Patent Document 1, at least the end surface of the spiral wrap of one scroll is separated from the substrate of the other scroll stepwise from the outside toward the center as viewed in the spiral direction. It is divided into two or more areas. According to this scroll compressor, even if the central portion of the movable and fixed scrolls is thermally expanded larger than the radially outer portion, the central region is separated from the substrate. Generation of galling between the substrate and the substrate is prevented.
Japanese Unexamined Patent Publication No. 2005-9332

  By the way, in the above-described scroll compressor of the prior art, the cutting tool having an outer diameter slightly larger than the width of the end surface of the spiral wrap is moved along the spiral direction while being applied to the end surface of the spiral wrap, and the substrate By gradually or stepwise changing the distance of the cutting tool from the end of the spiral wrap, the end surface of the spiral wrap was given a lap height that changed continuously or stepwise as viewed in the spiral direction.

For this reason, when manufacturing a scroll compressor of the prior art, not only an expensive NC milling machine is required, but detailed data on the spiral shape of the spiral wrap must be input to the NC milling machine, and the manufacturing process is complicated. Met.
Further, when processing a scroll having a different spiral wrap shape, it is necessary to input the respective shape data to the NC milling machine each time, so that it takes a long time to switch the setting of the NC milling machine. In addition, the distance to be processed along the spiral direction is approximately proportional to the length of the spiral wrap, and therefore is several tens of millimeters, and the processing itself takes a long time.

Further, the need for such expensive manufacturing equipment and the long time for manufacturing directly lead to an increase in the manufacturing cost of the scroll type fluid machine.
The present invention has been made in view of the above-described circumstances, and the object thereof is that although the end surface of at least one spiral wrap of the movable and fixed scrolls is divided into a plurality of regions having different wrap heights. Accordingly, it is an object of the present invention to provide a scroll type fluid machine that is easily manufactured in a short time and is particularly suitable for preventing the occurrence of galling between a movable scroll and a fixed scroll.

  In order to achieve the above object, according to the present invention, a movable scroll and a fixed scroll each having a spiral wrap integrally formed on a substrate are provided, and at least one end surface of the spiral wrap has a plurality of wrap heights different from each other. In the scroll-type fluid machine divided into regions, the end surface of the spiral wrap is obtained by processing each of two or more finishing surfaces having different distances from the substrate, and at least one of the finishing surfaces has a circular contour. A scroll type fluid machine is provided, characterized in that the scroll type fluid machine has a circular finished surface having a surface.

  In the scroll type fluid machine of the present invention, at least one finished surface is a circular finished surface having a circular contour. The circular finished surface is formed by arranging the end surface of the spiral wrap on the processing axis of the planar processing tool having a cutting edge at the tip, and then relatively rotating toward the end surface of the spiral wrap along the processing axis while rotating the planar processing tool. It is formed by cutting or grinding the area of the end face of the spiral wrap against which the tip of the feed and plane machining tool is pressed.

  In this way, when a circular finish surface is flattened by sending a plane machining tool relatively along the machining axis, it is not necessary to send the plane machining tool along the spiral direction of the spiral wrap, so the spiral wrap is placed on the NC milling machine. In addition, when processing a scroll having a different spiral wrap shape, the time for inputting the shape data and switching the setting of the NC milling machine is omitted.

Further, in this case, since the plane machining tool only needs to perform a simple operation of reciprocating on the machining axis relative to the end face of the spiral wrap, an expensive NC milling machine is not required and an inexpensive milling machine is required. Can be easily processed.
Furthermore, in this case, the distance to be machined by the plane machining tool is equal to the feed amount along the machining axis of the plane machining tool, and this feed amount is very small, for example, several tens of μm or less, and the plane machining is performed along the spiral direction. Compared with the case of sending the tool, the time required for the machining itself is greatly reduced.

Therefore, the scroll type fluid machine of the present invention is easily manufactured in a short time and inexpensive even though the end surface of at least one of the spiral wraps of the movable and fixed scrolls is divided into a plurality of regions having different wrap heights. It is.
Of the plurality of regions, it is preferable that the region closer to the center in the spiral direction has a smaller wrap height (Claim 2).

  In the scroll type fluid machine, for example, when operating as a compressor, a plurality of compression chambers formed between the movable scroll and the fixed scroll move from the radially outer side of the scroll toward the center, and along with this movement, The working fluid is compressed in each compression chamber. Since the temperature of the working fluid rises as the working fluid is compressed, the temperature at the central portion of the movable and fixed scrolls rises relative to the temperature at the radially outer portion.

  In the scroll type fluid machine according to claim 2, among the plurality of regions dividing the end surface of the spiral wrap, the region closer to the center in the spiral direction has a smaller wrap height. The gap between the scroll substrate and the scroll substrate is gradually increased from the outside toward the center in the spiral direction. By providing a gap that is increased stepwise toward the center in this manner, even when one or both of the central portions of the movable scroll and the fixed scroll are in thermal expansion in a direction close to each other during the operation, The occurrence of galling between the end face of the spiral wrap and the substrate facing the end face is prevented.

The end surface of the spiral wrap is divided into three or more regions as the plurality of regions, and at least two of the finished surfaces are the circular finished surfaces having different outer diameters of the contour, and among these circular finished surfaces, It is preferable that the circular finished surface having a small outer diameter of the contour is located inside the large circular finished surface (Claim 3).
Preferably, the end surface of the spiral wrap is divided into three or more regions as the plurality of regions, and at least two of the finished surfaces are the circular finished surfaces having different center positions of the contours. ).

The end face of the spiral wrap is divided into three or more regions as the plurality of regions, and two or more steps existing between the adjacent regions preferably have different step heights. ).
In the case of the scroll type fluid machine according to claim 3, claim 4, and claim 5, each region of the end surface of the spiral wrap has a wrap height corresponding to a variation in thermal expansion amount based on a temperature distribution in the movable and fixed scrolls. Thus, by dividing the end surface of the spiral wrap into three or more regions, the size of the gap existing between the end surface of the spiral wrap and the substrate facing the end surface is reduced when the scroll fluid machine is operated. Equalization is achieved. For this reason, according to this scroll type fluid machine, not only the occurrence of galling between the movable scroll and the fixed scroll is further prevented, but also the spiral wrap is removed from the high pressure compression chamber located in the center of these scrolls. The working fluid is prevented from leaking into the surrounding low-pressure compression chamber through a gap existing between the end face and the substrate facing the end face, whereby the working fluid is compressed with high efficiency.

In addition, in the scroll type fluid machine according to claim 3, the circular finished surface having a small outer diameter of the contour is located inside the large circular finished surface. If the surface processing is performed with the small circular finished surface after the surface processing by the above, the processing time of the small circular finished surface is shortened, and the manufacturing time of the fluid machine is also shortened.
Further, in the scroll type fluid machine according to claim 4, by changing the center position of the contour of the circular finished surface, a gap existing between the end face of the spiral wrap and the substrate facing the end face when the scroll type fluid machine is operated. The size can be further reduced and equalized. This is due to the following reason.

The shape of the spiral wrap is defined by an involute curve. The involute curve is drawn with reference to a basic circle located approximately in the center of the spiral, but the shape is not concentric with the basic circle as the center. Therefore, the variation in the thermal expansion amount of the scroll due to the temperature rise accompanying the compression of the working fluid is not concentric.
Therefore, in this scroll type fluid machine, by changing the center position of the contour of the circular finish surface, the end surface of the spiral wrap is divided into a plurality of regions so that each region has a lap height more corresponding to variation in thermal expansion amount. Thus, when the scroll type fluid machine is operated, the size of the gap existing between the end face of the spiral wrap and the substrate opposed to the end face can be further narrowed and equalized.

  Further, in the scroll type fluid machine according to claim 5, two or more steps existing between adjacent regions have different step heights, so that the end face of the spiral wrap and the end face are relatively opposed to each other during the operation of the scroll type fluid machine. Narrowing and equalization of the size of the gap existing between the substrate and the substrate to be performed is further achieved. That is, the variation in the amount of thermal expansion of the scroll is caused by the temperature of the working fluid, the shape of the scroll, etc., but in this scroll type fluid machine, two or more steps existing between adjacent regions are different from each other. By providing the height, the end surface of the spiral wrap is divided into a plurality of regions so that each region has a corresponding wrap height due to variations in the amount of thermal expansion. And the size of the gap existing between the end face and the substrate facing the end face are further reduced and equalized.

The working fluid applied to the scroll type fluid machine according to claims 2 to 5 may be CO ₂ (claim 6). When CO ₂ gas is compressed, the temperature of the central part of the movable and fixed scrolls is higher than that when compressing CFC-based gas such as R134a. As a result of this temperature rise, one or both of the central portions of the movable and fixed scrolls are greatly expanded in the direction in which they are close to each other. Even in the case where such thermal expansion occurs, in this scroll type fluid machine, the end face of the spiral wrap is divided into a plurality of regions, and the region closer to the center in the spiral direction is separated from the relatively sliding substrate. Therefore, the occurrence of galling between the movable scroll and the fixed scroll is surely prevented.

Moreover, according to this invention, the refrigeration cycle provided with the scroll type fluid machine as described in any one of Claim 2 thru | or 6 is applied (Claim 7).
Since the scroll type fluid machine applied to the refrigeration cycle of the present invention is highly reliable by preventing the occurrence of galling between the movable scroll and the fixed scroll, the refrigeration cycle itself is also highly reliable.

As described above, according to the first to sixth aspects of the present invention, even if the end surface of at least one spiral wrap of the movable scroll and the fixed scroll is divided into a plurality of regions, it can be manufactured in a short time and easily. An inexpensive scroll fluid machine is provided.
In particular, according to the second to sixth aspects of the present invention, it is possible to prevent the occurrence of galling between the movable scroll and the fixed scroll, and to provide a scroll type fluid machine having high reliability.

  Further, according to the present invention of claim 7, a highly reliable refrigeration cycle can also be provided.

FIG. 1 shows a refrigeration cycle (refrigeration circuit) of one embodiment applied to a vehicle air conditioning system.
The refrigeration cycle includes, for example, a circulation flow path 2 through which a refrigerant of CO ₂ gas circulates. The circulation flow path 2 has a scroll fluid machine 4 as a compressor, a radiator 6, and an expander as viewed in the flow direction of the refrigerant. 8, an evaporator 10 and an accumulator 12 are sequentially inserted.

  In this vehicle air-conditioning system, the scroll fluid machine 4 operates upon receiving power supply from the engine 14 of the vehicle, sucks and compresses low-temperature and low-pressure gas refrigerant from the return path of the circulation flow path 2, and the circulation flow path 2. High-temperature and high-pressure refrigerant is discharged in the forward path. The discharged refrigerant is cooled when passing through the radiator 6, and its temperature is lowered. And the refrigerant | coolant which temperature fell expands, when passing through the expander 8, the temperature and pressure fall, and it will be in a gas-liquid mixed state. When the refrigerant in the gas-liquid mixed state flows into the evaporator 10, the liquid refrigerant in the gas-liquid mixed state vaporizes in the evaporator 10, and the gas refrigerant mainly flows out from the evaporator 10. The refrigerant flowing out of the evaporator 10 passes through the accumulator 12 and is then sucked into the fluid machine 4.

  Here, in the vicinity of the radiator 6 and the evaporator 10, a heat radiating fan and a cooling fan (not shown) that form air passing outside the radiator 6 and the evaporator 10 are arranged, respectively. The refrigerant | coolant which passes the heat radiator 6 is cooled because 6 receives ventilation. Further, the air passing through the evaporator 10 is deprived of vaporization heat by the liquid refrigerant in the evaporator 10 and becomes cold air, and the cold air is blown out to the vehicle interior, thereby cooling the vehicle interior.

A housing 16 of the scroll type fluid machine 4 is formed of a drive side casing 18 and a compression side casing 20, and the casings 18 and 20 are coupled to each other via a connecting bolt 22.
A drive shaft 24 is disposed in the drive-side casing 18, and the drive shaft 24 has a large-diameter end portion 26 on the compression-side casing 20 side, and a small-diameter shaft portion 28 extends from the large-diameter end portion 26. A needle bearing 30 and a ball bearing 32 are interposed between the drive-side casing 18 and the large-diameter end portion 26 and the small-diameter shaft portion 28, respectively, and the drive shaft 24 is connected to the drive-side casing 18 via these bearings 30 and 32. It is supported rotatably.

A lip seal 34 is attached to the small-diameter shaft portion 28 between the ball bearing 32 and the large-diameter end portion 26, and the lip seal 34 is slidably contacted with the small-diameter shaft portion 28 to move inside the drive-side casing 18. It is airtight.
A small-diameter shaft portion 28 of the drive shaft 24 protrudes from the drive-side casing 18, and a driven-side unit of the electromagnetic clutch 36 is attached to the protruding end. The electromagnetic clutch 36 has a drive pulley 38 in its drive side unit, and the drive pulley 38 is rotatably supported by the drive side casing 18 via a bearing 40. The drive pulley 38 is rotated by receiving power from the engine 14, and the rotation of the drive pulley 38 can be transmitted to the drive shaft 24 via the electromagnetic clutch 36. Therefore, if the electromagnetic clutch 36 is turned on during driving of the engine, the drive shaft 24 rotates together with the drive pulley 38.

On the other hand, although not shown, the compression-side casing 20 is formed with a suction port and a discharge port on its peripheral wall, and the suction port and the discharge port are connected to the accumulator 12 and the radiator 6 via the circulation channel 2, respectively.
A scroll unit 42 is accommodated in the compression side casing 20, and a drive chamber 44 is formed between the scroll unit 42 and the lip seal 34, and between the scroll unit 42 and the peripheral wall of the compression side casing 20. A suction chamber 46 communicating with the suction port of the compression side casing 20 is formed.

  The scroll unit 42 includes an aluminum alloy movable scroll 48 and a fixed scroll 50 that are arranged to mesh with each other. The movable and fixed scrolls 48 and 50 are formed integrally with the substrate 52 and the substrate 52, respectively. It consists of a spiral wrap 54. Grooves are provided on the end faces of the spiral wraps 54, respectively, and spiral chip seals 56 are fitted into these grooves as seal members. The outer surface of the tip seal 56 is substantially flush with or slightly protrudes from the end faces of the spiral wrap 54, and the mutual spiral wraps between the movable and fixed scrolls 48, 50 via the tip seal 56. The end face of 54 and the substrate 52 are in sliding contact.

Here, the end surfaces of the spiral wraps 54 of the movable and fixed scrolls 48 and 50 are each stepped, and this will be described by taking the movable scroll 48 as an example.
As shown in FIG. 2, the end surface of the spiral wrap 54 of the movable scroll 48 is divided stepwise into first to fourth regions 57a to 57d from the center to the outside as viewed in the spiral direction, and adjacent regions 57a. Step surfaces 58a, 58b, and 58c exist between -d.

  As shown in FIG. 3, these regions 57a to 57d are all parallel to the substrate 52. Of these regions 57a to 57d, the distance from the substrate 52 is greater in the region closer to the center in the spiral direction. That is, the lap height is small. The step heights D1, D2, and D3 between the regions 57a to 57d are in the range of several μm to several tens of μm, respectively, and in the present embodiment, the intervals D1, D2, and D3 are substantially equal to each other.

Although not shown in a single figure, the end surfaces of the spiral wrap 54 of the fixed scroll 50 are also provided with step surfaces 58a, 58b, and 58c in the first to fourth regions 57a to 57d as in the case of the movable scroll 48. It is divided in stages (see FIGS. 2 and 3).
FIG. 3 is a schematic cross-sectional view in which the chip seal 56 and the groove of the chip seal 56 are omitted, and the step heights D1, D2, and D3 are exaggerated.

A compression chamber 59 serving as a pressure chamber is defined between the movable and fixed scrolls 48 and 50 described above via a tip seal 56, and this compression chamber 59 is moved by the swirling motion of the movable scroll 48. It moves from the radially outer side to the center in the spiral direction, and its volume is reduced.
In order to impart a turning motion to the movable scroll 48 described above, the movable scroll 48 and the large-diameter end portion 26 of the drive shaft 24 are connected to each other via a crank pin 60, an eccentric bush 62, and a needle bearing 64, and are movable. The rotation of the scroll 48 is prevented by a ball-type orbiting thrust bearing 66 disposed between the movable scroll 48 and the drive-side casing 18. Reference numeral 68 in FIG. 1 indicates a counterweight, and this counterweight 68 is attached to the eccentric bush 62.

  On the other hand, the fixed scroll 50 is fixed in the compression side casing 20, and the substrate 52 partitions the inside of the compression side casing 20 into a compression chamber 59 side and a discharge chamber 70. Further, a discharge hole 72 for communicating between the compression chamber 59 and the discharge chamber 70 is formed in the center of the substrate 52, and the discharge hole 72 is opened and closed by a reed valve 74 as a discharge valve. The reed valve 74 is attached to the outer surface of the substrate 52 together with the valve retainer 76 via bolts (not shown).

  According to the scroll type fluid machine 4 described above, the movable scroll 48 orbits through the crankpin 60 and the eccentric bush 62 as the drive shaft 24 rotates, and at this time, the movable scroll 48 functions as the orbiting thrust bearing 66. This prevents the rotation. As a result, the movable scroll 48 orbits with respect to the fixed scroll 50 while maintaining its orbiting posture constant. By this turning motion, a series of processes consisting of a refrigerant suction process from the suction port into the compression chamber 59, a compression process of the suctioned refrigerant in the compression chamber 59, and a discharge process of the compressed refrigerant from the discharge port are repeated. Executed.

Hereinafter, the method of forming the region 57 on the end face of the spiral wrap 54 of the movable and fixed scrolls 48 and 50 will be described taking the case of the movable scroll 48 as an example.
First, finish processing is performed on the entire end face of the spiral wrap 54 by plane cutting so that the entire end face is parallel to the substrate 52. Next, as shown in FIG. 4A, the machining axis of the milling cutter 80a having a cutting edge at the tip as a planar machining tool so that the region of the end surface excluding the portion that becomes the fourth region 57d is cut. Above, the end face of the spiral wrap 54 is arranged with the normal line aligned with the machining axis. Thereafter, while rotating the milling cutter 80a around the processing axis, the milling cutter 80a is relatively fed toward the end surface of the spiral wrap 54 along the processing axis, and the tip of the milling cutter 80a is pressed against the end surface of the spiral wrap 54 to perform plane cutting. (Planar processing) is performed. At the time of this planing, the milling cutter 80a hardly moves relative to the movable scroll 48 in the direction parallel to the substrate 52, and the side surface of the milling cutter 80a has the same curvature as that of the milling cutter 80a. An arc-shaped step surface 58c is formed and a fourth region 57d is defined.

  Thereafter, as shown in FIG. 4B, the milling cutter 80a is applied to the portion of the end face region of the spiral wrap 54 that has been plane-cut by the milling cutter 80a except for the portion that becomes the third region 57c. The milling cutter 80b having a smaller diameter is pressed while being rotated. Also at this time, the machining axis of the milling cutter 80b is aligned with the normal direction of the end face of the spiral wrap 54, and the milling cutter 80b is relatively fed toward the end face of the spiral wrap 54 along the machining axis. Accordingly, an arc-shaped step surface 58b having the same curvature as that of the milling cutter 80b is formed by the side surface of the milling cutter 80b, and a third region 57c is defined between the step surfaces 58b and 58c.

  Then, as shown in FIG. 4 (c), the milling cutter 80b removes the portion of the end face region of the spiral wrap 54 that has been plane-cut by the milling cutter 80b from the portion that becomes the second region 57b. The small-diameter milling cutter 80c is pressed while rotating. Also at this time, the machining axis of the milling cutter 80c is aligned in the normal direction of the end face of the spiral wrap 54, and the milling cutter 80c is relatively fed toward the end face of the spiral wrap 54 along the machining axis. Accordingly, an arc-shaped step surface 58a having the same curvature as that of the milling cutter 80c is formed by the side surface of the milling cutter 80c, and the second region 57b is defined between the step surfaces 58a and 58b. At the same time, the first region 57a is defined on the center side of the step surface 58a in the spiral direction.

  By the first to fourth regions 57a to 57d being partitioned on the end face of the spiral wrap 54 by the above-described method, the movable scroll 48 can move the milling cutters 80a to 80c as shown by the one-dot chain line in FIG. Virtually finished surfaces (circular finished surfaces) 82a to 82c having circular contours are provided as surfaces to be planed by the end surfaces. The surfaces where the finished surfaces 82a to 82c and the spiral wrap 54 intersect form the first to third regions 57a to 57c, in other words, the first to third regions 57a to 57c correspond to each other. Each of the finished surfaces 82a to 82c is included. Note that the outermost fourth region 57d as viewed in the spiral direction is also finished, but the finished surface of the fourth region 57d does not have a circular outline.

Hereinafter, the operation and effect of the scroll type fluid machine 4 will be described.
In the scroll type fluid machine 4, the first to fourth regions 57a to 57d are obtained by plane machining for each finished surface, and three of the finished surfaces have circular finished surfaces 82a to 82c each having a circular contour. It is. As described above, these circular finished surfaces 82a to 82c are arranged on the machining axis while rotating the planar machining tool after the end surface of the spiral wrap 54 is arranged on the machining axis of the planar machining tool having the cutting edge at the tip. It is formed by cutting or grinding the region of the end face of the spiral wrap 54 to which the tip end of the flat working tool is pressed against the end face of the spiral wrap 54.

  In this way, when the circular finishing surfaces 82a to 82c are planarized by relatively sending the plane machining tool along the machining axis, it is not necessary to send the plane machining tool along the spiral direction of the spiral wrap 54. It is not necessary to input the shape data of the spiral wrap 54 to the milling machine. In addition, when processing a scroll having a different shape of the spiral wrap 54, the time for inputting the shape data and switching the setting of the NC milling machine is omitted.

Further, in this case, since the planar machining tool only needs to perform a simple operation of reciprocating on the machining axis relative to the end surface of the spiral wrap 54, an expensive NC milling machine is not required and is inexpensive. Can be easily processed using a milling machine.
Furthermore, in this case, the distance to be machined by the plane machining tool is equal to the feed amount along the machining axis of the plane machining tool. This feed amount is very small, for example, several tens of μm or less, and the plane machining is performed along the spiral direction. Compared with the case of sending the tool, the time required for the machining itself is greatly reduced.

Therefore, the scroll type fluid machine 4 can be easily manufactured in a short time even though the end surfaces of the spiral wraps 54 of the movable and fixed scrolls 48 and 50 are divided into a plurality of regions 57a to 57d having different wrap heights. It is cheap.
In the scroll type fluid machine 4, the CO ₂ gas as the working fluid is compressed in the compression chamber 59 between the movable scroll 48 and the fixed scroll 50 during the operation, and the temperature of the CO ₂ gas is increased with this compression. Since the temperature rises, the temperature at the central portion of the movable and fixed scrolls 48 and 50 rises relatively higher than the temperature at the radially outer portion.

  In this scroll type fluid machine 4, the end faces of the spiral wraps 54 of the movable and fixed scrolls 48, 50 are stepped from the substrate 52 of the scrolls 50, 48 that are in sliding contact with each other in the spiral direction from the outside toward the center. Even if the central portions of the movable and fixed scrolls 48, 50 are thermally expanded in a direction closer to each other as compared to the radially outer portions, the spiral wraps are cut. The occurrence of galling between the end face 54 and the substrate 52 facing the end face is prevented. Therefore, this scroll type fluid machine 4 has high reliability.

And the refrigerating cycle provided with the scroll type fluid machine 4 mentioned above as a compressor also has high reliability.
The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the refrigeration cycle of the present invention includes a vehicle air conditioning system, a home / business indoor air conditioning system or a refrigeration / cooling system. It can also be applied to uses such as refrigerators. The refrigeration cycle may use a condenser instead of the radiator 6 or a receiver instead of the accumulator 12 according to the application, or between the forward path and the return path of the circulation path 2. An internal heat exchanger may be provided.

Scroll fluid machine 4 of an embodiment, but were fixed displacement scroll type fluid machine of the present invention may be a variable displacement type or closed type, Besides CO ₂ gas, various Applicable to compression or expansion of working fluid.
That is, even when the fluorocarbon gases such as R134a, R152a, and R600a are compressed, the temperature of the central portion of the movable and fixed scrolls 48 and 50 rises. However, in the scroll type fluid machine 4, two end faces of the spiral wrap 54 are provided. Since the region 57a on the center side is separated from the substrate 52 that is in sliding contact with the regions 57b to 57d on the outer side in the radial direction as viewed in the spiral direction, the movable scroll 48 and the fixed scroll 50 are separated from each other. The occurrence of galling during the period is preferably prevented.

  In the scroll type fluid machine 4 of the embodiment, although the plurality of regions 57 are formed on the end faces of the spiral wraps 54 of both the movable and fixed scrolls 48 and 50, the spiral wraps of at least one of the scrolls 48 and 50 is formed. If the region 57 is formed only on the end face 54, the occurrence of galling between the movable scroll 48 and the fixed scroll 50 can be prevented. However, if the region 57 is formed on the end surfaces of the spiral wraps 54 of both the movable and fixed scrolls 48 and 50, the occurrence of galling can be more suitably prevented.

  In the scroll type fluid machine 4 according to the embodiment, the end surface of the spiral wrap 54 is divided into four regions 57a to 57d. However, if the end surface of the spiral wrap 54 is divided into at least two regions 57, the movable scroll is provided. It is possible to prevent galling between 48 and the fixed scroll 50. However, if the end face of the spiral wrap 54 is divided into three or more regions 57, the occurrence of galling can be suitably prevented.

  That is, the end face of the spiral wrap 54 is divided into three or more regions 57 so that each region 57 has a wrap height corresponding to the variation in thermal expansion amount based on the temperature distribution in the movable and fixed scrolls 48 and 50. Thus, the size of the gap existing between the end face of the spiral wrap 54 and the substrate 52 facing the end face during the operation of the scroll type fluid machine 4 can be reduced and equalized.

  By narrowing and equalizing the size of the gap as described above, according to the scroll type fluid machine 4, not only the occurrence of galling between the movable scroll 48 and the fixed scroll 50 is further prevented, but also these scrolls. The working fluid is prevented from leaking from the high-pressure compression chamber 59 located in the center of 48 and 50 to the surrounding low-pressure compression chamber 59 through a gap existing between the end face of the spiral wrap 54 and the substrate 52, thereby operating. The fluid is compressed with high efficiency.

In the scroll type fluid machine 4 of one embodiment, of the circular finished surfaces 82a to 82c, a circular finished surface having a small outer diameter, for example, a circular finished surface 82b is a large circular finished surface, for example, a circular finished surface 82c. Although located on the radially inner side, a part of the small circular finished surface may protrude from the larger circular finished surface to the radially outer side.
However, if the small circular finish surface is inside the large circular finish surface in the radial direction, the processing time of the small circular finish surface can be reduced by flattening with the large circular finish surface and then with the small circular finish surface. Is reduced, and as a result, the manufacturing time of the fluid machine is also reduced.

  In the scroll type fluid machine 4 of one embodiment, although the center positions of the contours of the circular finished surfaces 82a to 82c are different, the center positions of the contours of the circular finished surfaces 82a to 82c may not be different. However, by changing the center positions of the contours of the circular finished surfaces 82a to 82c, the size of the gap existing between the end surface of the spiral wrap 54 and the substrate 52 facing the end surface when the scroll fluid machine 4 is operated. Narrowing and equalization are further achieved. This is due to the following reason.

The shape of the spiral wrap 54 is defined by an involute curve. The involute curve is drawn with reference to a basic circle located approximately in the center of the spiral, but the shape is not concentric with the basic circle as the center. Therefore, the variation in the thermal expansion amount of the scrolls 48 and 50 due to the temperature rise accompanying the compression of the working fluid is not concentric.
Therefore, in the scroll type fluid machine 4, the spiral wrap 54 is formed so that the regions 57a to 57d have a corresponding wrap height due to variations in the amount of thermal expansion by changing the center positions of the contours of the circular finished surfaces 82a to 82c. The end surface of each of the spiral wraps 54 is divided into a plurality of regions 57, so that the gap between the end surface of the spiral wrap 54 and the substrate 52 facing the end surface is narrowed and equalized when the scroll type fluid machine 4 is operated. It is even more planned.

  In the scroll type fluid machine 4 according to the embodiment, two or more step surfaces 58a to 58c existing between adjacent regions 57a to 57d have the same step heights D1, D2, and D3. Preferably it has a height. The two or more steps 58a to 58c existing between the adjacent regions 57a to 57d have different step heights, so that the end surface of the spiral wrap 54 and the substrate 52 facing the end surface when the scroll type fluid machine is operated. This is because the size of the gaps between them can be further narrowed and equalized.

  That is, the variation in the thermal expansion amount of the scrolls 48 and 50 occurs due to the temperature of the working fluid, the shape of the scrolls 48 and 50, and the like, but two or more steps 58a to 58 existing between the adjacent regions 57a to 57d. By giving c different step heights to each other, the end surface of the spiral wrap 54 is divided into a plurality of regions 57 so that each region 57a-d has a corresponding wrap height due to variations in the amount of thermal expansion. The size of the gap existing between the end face of the spiral wrap 54 and the substrate 52 facing the end face during the operation of the die fluid machine is further reduced and equalized.

  In the scroll type fluid machine 4 of one embodiment, when the end face of the spiral wrap 54 is divided into the plurality of regions 57, the milling cutters 80a, 80b and 80c are used in this order. However, as shown in FIG. The milling cutters 80c, 80b and 80a may be used in this order by reversing the above. However, as shown in FIG. 4, if the milling cutters 80a, b, c are used in order of decreasing outer diameter in stages, the amount of cutting by the milling cutters b, c to be used later is reduced, and the machining time is reduced. Therefore, the scroll type fluid machine 4 can be manufactured in a shorter time.

  In the scroll type fluid machine 4 of one embodiment, the movable and fixed scrolls 48 and 50 are made of an aluminum alloy, but the material of the scrolls 48 and 50 is not particularly limited, and may be made of iron or the like.

It is the schematic block diagram which showed the refrigerating cycle of one Example applied to the vehicle air conditioning system by making the scroll type fluid machine into the longitudinal cross-section. It is a top view of the movable scroll applied to the fluid machine of FIG. It is the figure which showed typically the cross section which follows the III-III line | wire in FIG. It is a figure for demonstrating the manufacturing method of the scroll of FIG. 3, (a) is a 3rd area | region, (b) is a 2nd area | region, (c) is the state cut to the 1st area | region, respectively. Show. It is a top view for demonstrating the positional relationship of a finishing surface and a spiral wrap in the scroll of FIG. It is a figure for demonstrating the other manufacturing method of the scroll of FIG. 3, (a) is a 1st area | region, (b) is a 2nd area | region, (c) is the state cut to the 3rd area | region. Respectively.

Explanation of symbols

48 movable scroll 50 fixed scroll 52 substrate 54 spiral wrap 57a, b, c, d first to fourth regions 58a, b, c, d stepped surface 82a, b, c (circular) finished surface

Claims (7)

In a scroll type fluid machine comprising a movable scroll and a fixed scroll each having a spiral wrap integrally formed on a substrate, and an end face of at least one of the spiral wraps is divided into a plurality of regions having different wrap heights,
The end surface of the spiral wrap is obtained by processing each of two or more finished surfaces having different distances from the substrate,
The scroll type fluid machine according to claim 1, wherein the at least one finishing surface is a circular finishing surface having a circular contour.   2. The scroll fluid machine according to claim 1, wherein among the plurality of regions, the region closer to the center in the spiral direction has a smaller wrap height. The end face of the spiral wrap is divided into three or more regions as the plurality of regions,
At least two of the finished surfaces are the circular finished surfaces having different outer diameters of the contours;
The scroll type fluid machine according to claim 2, wherein a circular finishing surface having a small outer diameter of the contour is located inside a large circular finishing surface among the circular finishing surfaces. The end face of the spiral wrap is divided into three or more regions as the plurality of regions,
The scroll type fluid machine according to claim 2, wherein at least two of the finished surfaces are the circular finished surfaces having different center positions of the contours. The end face of the spiral wrap is divided into three or more regions as the plurality of regions,
3. The scroll type fluid machine according to claim 2, wherein two or more steps existing between the adjacent regions have different step heights. The scroll type fluid machine according to claim ₂ , wherein the working fluid is CO ₂ .   A refrigeration cycle comprising the scroll fluid machine according to any one of claims 2 to 6.

Images