JP2011038480A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine wherein a scroll unit achieves enhanced performance while securing reliability. <P>SOLUTION: The scroll fluid machine is provided with: a first actuation chamber (100) and a second actuation chamber (102) partitioned by a central end (98) of a wrap (48, 64) of a fixed scroll (44, 60) and a central end (96) of a wrap (46, 62) of a movable scroll (42, 58); and a connection path (106, 119, 112), which when at least part of a connection hole (52, 72) gets blocked by the central end of the wrap of the movable scroll as the movable scroll is moved to revolve, connects the first and second actuation chambers with the connection hole, and when the central ends of the wraps of the fixed and movable scrolls abut against each other, cuts off the connection between the first and second actuation chambers and the connection hole. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine.

  This type of scroll type fluid machine includes a scroll unit, and the scroll unit is composed of fixed and movable scrolls each having a spiral wrap opposed to each base surface of each substrate. Then, the movable scroll is revolved to form a working chamber for refrigerant as a working fluid of the fluid machine between the laps of the fixed and movable scrolls. When this fluid machine is used as an expander, a suction hole is formed through the central portion of the fixed scroll substrate, and a refrigerant is supplied from the refrigerant circuit outside the scroll unit to the expansion chamber as a refrigerant working chamber. Inhale.

  And in patent document 1, in order to correct the imbalance between the working chambers at the start of expansion of the refrigerant and to cause the scroll unit to perform efficient expansion operation, the tooth portion (lap) of the orbiting scroll (movable scroll). When the concave portion is formed at the central tip of the first opening and the introduction port (suction hole) is open to the first working chamber, the second working chamber and the introduction port communicate with each other, and the first working chamber and the introduction port A technique is disclosed in which the recess is shut off from the second working chamber at the same timing when is shut off.

JP 2006-242133 A

  However, in the case of the above-described prior art, since the concave portion is formed at the center front end portion of the movable scroll wrap, the strength of the wrap is lowered, and there is a possibility that the movable scroll is damaged due to the revolving orbiting motion.

  Further, in the case of the above prior art, at least a part of the suction hole is closed by the central tip of the wrap as the movable scroll revolves, so that the amount of refrigerant taken into the scroll unit is reduced and the scroll is reduced. There exists a problem that the expansion efficiency of the refrigerant | coolant in a unit falls, and the subject remains in the improvement of the operating efficiency of the refrigerant | coolant in a scroll unit.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a scroll type fluid machine that can improve the performance of the scroll unit while ensuring the reliability of the scroll unit.

  In order to achieve the above object, the scroll type fluid machine according to claim 1 is composed of a fixed scroll and a movable scroll each having a spiral wrap opposed to each base surface of each substrate. A movable scroll is revolved around the center to form a working chamber for working fluid between the wraps of the fixed and movable scrolls, and the working chamber and the scroll are formed through the central portion of the fixed scroll substrate. A first working chamber defined by a communication hole for communicating with the outside of the unit, an outer wall of a central tip portion of the fixed scroll wrap and an inner wall of a central tip portion of the movable scroll wrap, and a central tip portion of the fixed scroll wrap The second working chamber defined by the inner wall of the movable scroll and the outer wall of the central tip of the movable scroll wrap, and the number of communication holes are reduced along with the orbiting revolution of the movable scroll. When at least a part of the movable scroll wrap is closed by the central tip of the movable scroll, the first and second working chambers communicate with the communication hole, and the central tips of the fixed and movable scroll wrap are brought into contact with each other. And a communication passage for blocking communication between the first and second working chambers and the communication hole.

  According to a second aspect of the present invention, in the first aspect, the communication path is a communication groove that is recessed in the base surface of the fixed scroll to reach the communication hole, and the communication groove is a revolving orbiting motion of the movable scroll. Accordingly, when at least a part of the communication hole is blocked by the central tip of the movable scroll wrap, at least a part of the communication groove is opened to the first and second working chambers, and the fixed and movable scroll wraps are opened. When the central tip portions are brought into contact with each other, the entire communication groove is formed in a range covered by the wrap of the movable scroll.

  Further, in the invention according to claim 3, in claim 2, the communication groove has a first working chamber and a second working chamber when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll. It is characterized by communicating with.

  Furthermore, in the invention according to claim 4, in claim 2, the communication groove comprises a first working chamber, a communication hole, and a communication hole when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll. The first communication groove is configured to communicate with the second working chamber and the second communication groove is configured to communicate with the communication hole.

  According to a fifth aspect of the present invention, in the second aspect of the present invention, when the communication groove is at least partially closed by the central tip of the movable scroll wrap, It is characterized in that the open areas of the communication grooves are formed in a range that is substantially the same.

Furthermore, in the invention described in claim 6, in any one of claims 3 to 5, the scroll unit has a symmetric scroll structure.
Furthermore, the invention described in claim 7 is characterized in that, in claim 2, the communication groove has a groove width smaller than the width of the central tip of the wrap of the movable scroll.

  The invention according to claim 8 is the expansion machine according to claim 1, wherein the working chamber is an expansion chamber.

  According to the scroll type fluid machine of the first aspect of the present invention, since the communication passage is provided, at least a part of the communication hole is closed by the central tip of the movable scroll wrap as the movable scroll revolves. However, since the flow path of the working fluid between the first and second working chambers and the communication hole can be enlarged, a decrease in the amount of working fluid flowing between the working chamber and the outside of the scroll unit is prevented. be able to.

  Further, even if the center tip portions of the fixed and movable scroll laps come into contact with each other along with the revolving orbiting motion of the movable scroll, the communication between the first and second working chambers and the communication hole can be blocked. A working chamber that is completely blocked from the first and second working chambers can be formed in the central portion where the hole is opened. Therefore, it is possible to prevent a decrease in the amount of working fluid flowing between the working chamber and the outside of the scroll unit while preventing leakage of the working fluid from the working chamber. A drop can be prevented, and the performance of the scroll unit can be improved while ensuring the reliability of the scroll unit.

  According to the second aspect of the invention, specifically, the communication path is a communication groove that is recessed in the base surface of the fixed scroll to reach the communication hole, and the communication groove is the revolution of the movable scroll. When at least a part of the communication hole is closed by the central tip of the movable scroll wrap with the turning motion, at least a part of the communication groove is opened in the first and second working chambers, and the fixed and movable scroll When the central front ends of the wraps are brought into contact with each other, the entire communication groove is formed in a range covered by the wrap of the movable scroll. As a result, the performance of the scroll unit is improved while the reliability of the scroll unit is ensured with a simple configuration that does not impair the durability of the scroll unit by processing the lap of the movable scroll, without losing the durability of the scroll unit. can do.

  According to a third aspect of the present invention, the communication groove communicates between the first working chamber and the second working chamber when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll. Let Accordingly, when at least a part of the communication hole is blocked by the central front end of the wrap of the movable scroll, the first working chamber and the second working chamber can be equalized. The working fluid can be circulated more smoothly between the outside and the working efficiency of the working fluid in the scroll unit can be further improved.

  Furthermore, according to the invention described in claim 4, the communication groove allows the first working chamber and the communication hole to communicate with each other when at least a part of the communication hole is blocked by the central front end portion of the wrap of the movable scroll. The first communication groove includes a second communication groove that communicates the second working chamber and the communication hole. As a result, the degree of freedom of the shape of the communication groove is increased, so that the center tip portions of the fixed and movable scroll laps are brought into contact with each other with the revolving orbiting motion of the movable scroll, and the first and The first and second communication grooves can be formed in the ranges opened to the first and second working chambers, respectively, until just before the working chamber completely cut off from the second working chamber is formed. Therefore, the working fluid can be circulated more smoothly between the working chamber and the outside of the scroll unit, and the working efficiency of the working fluid in the scroll unit can be further improved.

  According to the fifth aspect of the present invention, the communication groove is connected to the first and second working chambers when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll. Are formed in a range where the opening areas are substantially the same. Thereby, when at least a part of the communication hole is blocked by the central tip of the movable scroll wrap, substantially the same amount of working fluid can be circulated in the first working chamber and the second working chamber. The working fluid can be circulated more smoothly between the working chamber and the outside of the scroll unit, and the working efficiency of the working fluid in the scroll unit can be further improved.

  Furthermore, according to the sixth aspect of the invention, since the scroll unit has a symmetrical scroll structure, the working fluid can smoothly flow between the working chamber and the outside of the scroll unit. The imbalance between the working chambers at the time is corrected, and flapping of the movable scroll with respect to the fixed scroll can be surely prevented. Therefore, it is possible to improve the performance of the scroll unit while ensuring the reliability of the scroll unit.

  Further, according to the seventh aspect of the present invention, the communication groove has a groove width smaller than the width of the center tip portion of the movable scroll wrap, so that the center of the movable wrap is rotated along with the orbital revolving motion. The tip portion is prevented from being caught in the communication groove, and the performance of the scroll unit can be improved more reliably while ensuring the reliability of the scroll unit.

  According to the eighth aspect of the invention, specifically, the scroll type fluid machine is an expander having the working chamber as an expansion chamber, so that the expansion efficiency of the working fluid in the scroll unit can be improved. .

It is a longitudinal section of a scroll type fluid machine concerning one embodiment of the present invention. It is the top view which looked at the center part of the expansion side scroll unit concerning a 1st embodiment of the present invention from the movable scroll side just before formation of a central expansion chamber. (A) The top view which showed the center part of only the fixed scroll of the expansion side scroll unit of FIG. 2, (b) It is sectional drawing which looked at the AA cross section of Fig.3 (a) from the arrow direction. It is the top view which looked at the center part of the expansion side scroll unit of FIG. 2 from the movable scroll side at the time of formation of a center expansion chamber. It is the top view which looked at the center part of the expansion side scroll unit of FIG. 4 from the movable scroll side after formation of a center expansion chamber. It is the top view which looked at the center part of the expansion side scroll unit which concerns on 2nd Embodiment of this invention from the movable scroll side just before formation of a center expansion chamber. It is the top view which looked at the center part of the expansion side scroll unit of FIG. 6 from the movable scroll side at the time of formation of a center expansion chamber. It is the top view which looked at the center part of the expansion side scroll unit of FIG. 7 from the movable scroll side after formation of a center expansion chamber. It is the top view which looked at the center part of the expansion side scroll unit which concerns on the modification of 2nd Embodiment of this invention from the movable scroll side at the time of formation of a center expansion chamber.

  FIG. 1 is a longitudinal sectional view of a scroll type fluid machine 1. The fluid machine 1 is, for example, a vertically installed compressor-integrated expander, and is inserted in a refrigeration cycle (not shown) such as a heat pump in which a supercritical carbon dioxide refrigerant circulates. It is incorporated in a machine and a heat pump type hot water heater. In this refrigeration cycle, the expansion energy of the refrigerant is converted into power by an expander 4 described later, and the compressor 2 is driven.

The fluid machine 1 includes a housing 6, and a drive shaft 8 that drives the fluid machine 1 is extended in the housing 6 with its longitudinal direction arranged in the vertical direction.
The drive shaft 8 is configured by connecting an upper shaft portion 8a and a lower shaft portion 8b, and an upper eccentric shaft portion 10a that is eccentric from the axis of the drive shaft 8 is integrally formed at the upper end of the upper shaft portion 8a. A compression-side scroll unit (scroll unit) 14 is connected to the upper eccentric shaft portion 10 a via a bearing portion 12.

  On the other hand, a lower eccentric shaft portion 10b that is eccentric from the axis of the drive shaft 4 is integrally formed at the lower end of the lower shaft portion 8b, and the lower eccentric shaft portion 10b is connected to the expansion side via a bearing portion 16. A scroll unit (scroll unit) 18 is connected. Thus, in the housing 6, the compressor 2 and the expander 4 to which the common drive shaft 8 is connected are accommodated in the vertical direction in order from the top.

  The housing 6 includes a center shell 20 that forms a cylindrical body of the fluid machine 1, a cap-like top shell 22 that covers the upper part of the fluid machine 1, and a cap-like bottom shell 24 that covers the lower part of the fluid machine 1. ing. On the inner side of the center shell 20, an upper frame 28 that rotatably supports the upper shaft portion 8 a via the bearing portion 26, and a lower frame 32 that rotatably supports the lower shaft portion 8 b via the bearing portion 30. And are fixed. A balance weight 34 is supported and fixed to the lower shaft portion 8b, and the balance weight 34 rotates with the rotation of the drive shaft 8 in a space 36 between the upper frame 28 and the lower frame 32 inside the center shell 20. Is done.

The housing 6 is sealed by the shells 20, 22, and 24, and the pressure of the refrigerant as the working fluid of the fluid machine 1 taken in from the external circuit is applied to the inside of the housing 6.
Specifically, the bottom shell 24 is connected to a suction pipe 38 that sucks the refrigerant taken in from the external circuit, and a suction chamber 40 is formed inside the bottom shell 24, and the suction pipe 38 opens to the suction chamber 40. Has been.

The expander 4 includes a movable scroll 42 and a fixed scroll 44, and spiral wraps 46 and 48 each having a predetermined involute curve are formed on the base surfaces 42 b and 44 b of the respective substrates 42 a and 44 a of the scrolls 42 and 44. Are standing upright.
The movable scroll 42 is supported by the pedestal portion of the lower frame 32 so as to be capable of revolving and revolving, and a boss portion 50 projects from a back surface 42c opposite to the base surface 42b. The eccentric shaft portion 10b is connected.

  The fixed scroll 44 is fixed inside the center shell 20, and a suction hole (communication hole) 52 is formed through the central portion of the substrate 44 a of the fixed scroll 44. The suction hole 52 is opened to the suction chamber 40. Yes. A refrigerant discharge chamber 54 is formed inside the outer periphery of the fixed scroll 44, and a discharge pipe 56 that discharges the refrigerant that has passed through the expansion side scroll unit 18 to the outside of the housing 6 is connected to the discharge chamber 54.

  According to the expander 4 described above, as indicated by solid arrows in FIG. 1, the refrigerant sucked from the suction pipe 38 is taken into the expansion side scroll unit 18 through the suction chamber 40 and the suction hole 52, The movable and fixed scrolls 42 and 44 cooperate with each other to be expanded in an expansion chamber formed between the wraps 46 and 48 of the scrolls 42 and 44. The volume of the expansion chamber is increased while moving toward the outer peripheral side of each of the scrolls 42 and 44, and accordingly, the movable scroll 42 is revolved around the axis of the fixed scroll 44.

  The drive shaft 8 is rotationally driven in accordance with the revolving orbiting motion of the movable scroll 42, and the refrigerant used for the revolving orbiting motion of the movable scroll 42 and thus generating the driving force of the driving shaft 8 passes through the discharge chamber 54 through the discharge pipe 56. It is sent to an external circuit outside the housing 6.

  On the other hand, the compressor 2 includes a movable scroll 58 and a fixed scroll 60, and a spiral wrap 62 having a predetermined involute curve is formed on the base surfaces 58 b and 60 b of the substrates 58 a and 60 a of the scrolls 58 and 60. 64 are erected in opposition.

The movable scroll 58 is supported by the pedestal portion of the upper frame 28 so as to be capable of revolving and revolving, and a boss portion 66 projects from a back surface 58c opposite to the base surface 58b. The boss portion 66 has an upper eccentric shaft. The part 10a is connected.
Connected to the top shell 22 is a discharge pipe 68 for discharging the refrigerant that has passed through the compression-side scroll unit 14 to the outside of the housing 6, and the discharge pipe 68 is opened to a discharge chamber 70 formed inside the top shell 22. .

  The fixed scroll 60 is fixed to the inside of the center shell 20, and a discharge hole (communication hole) 72 opened to the discharge chamber 70 is formed through the central portion of the substrate 60 a of the fixed scroll 60. A suction chamber 74 is formed inside, and a suction pipe 76 is connected to the suction chamber 74.

  According to the compressor 2 described above, as indicated by a solid line arrow in FIG. 1, the refrigerant sucked from the suction pipe 76 is taken into the compression side scroll unit 14 through the suction chamber 74, and is movable and fixed scroll. 58 and 60 are compressed in a compression chamber formed between the wraps 62 and 64 of the scrolls 58 and 60 by cooperating with each other. The volume of the compression chamber moves while the movable scroll 58 revolves around the axis of the fixed scroll 60 by the rotation of the drive shaft 8 via the boss portion 66, and moves toward the center of each scroll 58, 60. Is reduced. Then, the refrigerant whose pressure has been increased with the decrease in the volume of the compression chamber passes through the discharge hole 72 and the discharge chamber 70 and is sent to an external circuit outside the housing 6 through the discharge pipe 68.

Thus, in the fluid machine 1, the driving side expansion side scroll unit 18 is driven by the pressure of the refrigerant, and the driven side compression side scroll unit 14 is driven by this power.
On the other hand, the space 36 is formed with a lubricating oil chamber 78 in which lubricating oil for lubricating the expansion side and compression side scroll units 18 and 14 is stored.

  Specifically, an oil passage 80 that opens at the upper end of the upper shaft portion 8a is formed along the axial direction of the drive shaft 8, and an oil passage 82 that opens at the lower end of the lower shaft portion 8b. Is drilled so as to communicate with the oil passage 80 along the axial direction of the drive shaft 8. The oil passages 80 and 82 communicate with the lubricating oil chamber 78 through an oil supply hole (not shown) drilled along the radial direction of the drive shaft 8.

  The lubricating oil stored in the lubricating oil chamber 78 is discharged from the upper end and the lower end of the drive shaft 8 through the oil passages 80 and 82 from the oil supply holes, as indicated by dotted arrows in FIG. 16, the bearings 26 and 30 are lubricated, while the upper frame 28 and the rear surface 58c of the movable scroll 58 are formed, and the lower frame 32 and the rear surface 42c of the movable scroll 42 are formed. Lubrication oil back pressure chambers 84 and 86 lubricate the sliding portions of the scroll units 14 and 18. Further, the movable scrolls 42 and 58 are pressed and urged against the fixed scrolls 44 and 60 by the pressures of the back pressure chambers 84 and 86, respectively, whereby the movable scrolls 42 and 58 against the fixed scrolls 44 and 60 are pressed. Smooth revolving motion is possible.

  The upper frame 28 is provided with an oil passage 88 from the back pressure chamber 84 to the space 36, and the lower frame 32 is provided with an oil passage 90 from the space 36 to the back pressure chamber 86. An oil guide pipe 92 is connected to the opening on the space 36 side of each oil passage 88, 90, and the oil guide pipe 92 is disposed in an airtight manner with the lubricating oil chamber 78 in the space 36. A back pressure adjusting mechanism 94 for the back pressure chamber 86 is provided in the middle of the oil passage 90, and the oil passage 90 is also used as a pressure release passage for releasing excessive high pressure in the back pressure chamber 86 into the pressure guiding pipe 92.

  In this way, the lubricating oil used for the expansion side scroll unit 18 side lubrication and the formation of the back pressure chamber 86 is transferred to the back pressure chamber 84 via the oil guide pipe 92 as indicated by the dotted line arrow in FIG. Is supplied and contributes to the formation of the back pressure chamber 84. Lubricating oil that has contributed to the formation of the back pressure chamber 84 is supplied to the suction chamber 74 through a pressure adjusting mechanism (not shown) that connects the back pressure chamber 84 and the suction chamber 74, and after lubricating the compression scroll unit 14, The liquid is delivered to an external circuit outside the housing 6 via the discharge pipe 68 through the discharge hole 72 and the discharge chamber 70.

  2, 4 and 5 are plan views of the central portion of the expansion side scroll unit 18 according to the first embodiment as viewed from the movable scroll 42 side. In each of these drawings, a first expansion chamber (first working chamber) defined by an outer wall 98a of the central tip portion 98 of the wrap 48 of the fixed scroll 44 and an inner wall 96b of the central tip portion 96 of the wrap 46 of the movable scroll 42 is shown. 100 and a second expansion chamber (second working chamber) 102 defined by an inner wall 98b of the central tip 98 of the wrap 48 of the fixed scroll 44 and an outer wall 96a of the central tip 96 of the wrap 46 of the movable scroll 42. It is shown.

In FIG. 2, a central expansion chamber (working chamber) 104 that is completely cut off from the first and second working chambers 100 and 102 is formed at a position where the suction hole 52 is opened along with the revolving orbiting motion of the movable scroll 42. This shows the state just before
On the base surface 44 b of the fixed scroll 44, one continuous communication groove (communication path) 106 is recessed in a range reaching the suction hole 52.

  Specifically, referring to the plan view showing only the center portion of the fixed scroll 44 in FIG. 3A, a part of the outer edge of the communication groove 106 extends along the inner wall 98 b and straddles the outer edge of the communication groove 106 across the suction hole 52. In this way, the planar shape of the entire communication groove 106 when connected to the phantom line 108 indicated by the alternate long and short dash line in FIG. 3A is substantially S-shaped including at least a part of the suction hole 52.

  In addition, as shown in the cross-sectional view of the AA cross section in FIG. 3A viewed from the direction of the arrow in FIG. 3B, an annular step 52 a is formed at the opening edge of the suction hole 52. The groove bottom surface 106a of the communication groove 106 is formed in a range from the base surface 44b to the step portion 52a, and the communication groove 106 is communicated with the suction hole 52 through the step portion 52a.

  By forming the communication groove 106 in such a shape and range, at least a part of the suction hole 52 is at the center front end of the lap 46 of the movable scroll 42 immediately before the refrigerant intake is completed, in which the central expansion chamber 104 is formed. When closed by the portion 96, at least a part of the communication groove 106 is opened to the first and second expansion chambers 100 and 102, and as shown by a solid line in FIG. A refrigerant path larger than the gaps G1 and G2 between 96 and 98 is formed, and the refrigerant flows into the first and second expansion chambers 100 and 102 from the suction hole 52 through the refrigerant path.

At this time, the first expansion chamber 100 and the second expansion chamber 102 are communicated with each other via the communication groove 106, and the refrigerant flows between the first and second expansion chambers 100 and 102.
Further, at this time, the shape and range of the communication groove 106 are set in advance so that the opening areas of the communication grooves 106 with respect to the first and second expansion chambers 100 and 102 are substantially the same.

  FIG. 4 shows a state in which the revolving turning of the movable scroll 42 further proceeds from the state of FIG. 2, the central expansion chamber 104 is formed, and the refrigerant intake is finished. As is apparent from this figure, the communication groove 106 is formed when the central expansion chamber 104 is formed, and the central tip portions 98 and 96 of the wraps 48 and 46 of the fixed and movable scrolls 44 and 42 are brought into contact with each other. In this case, the entire communication groove 106 is formed over a range covered by the wrap 46 of the movable scroll 42.

  FIG. 5 shows a state after the revolution of the movable scroll 42 further proceeds from the state of FIG. 4 and the central expansion chamber 104 is formed. As is clear from this figure, the communication groove 106 is not only before and during the formation of the central expansion chamber 104, but also after the formation of the central expansion chamber 104, the revolving orbiting motion of the movable scroll 42 and the first and second expansions. The expansion chambers including the chambers 100 and 102 are formed over a range that does not hinder the formation. Specifically, the communication groove 106 is formed over a range in which the groove width is smaller than the width of the central front end portion 96 of the wrap 46 of the movable scroll 42.

  As described above, in the present embodiment, by having the communication groove 106, at least a part of the suction hole 52 is closed by the central front end portion 96 of the wrap 46 of the movable scroll 42 along with the revolution turning motion of the movable scroll 42. Even immediately before the formation of the central expansion chamber 104, that is, just before the end of refrigerant intake, the refrigerant flow path between the first and second expansion chambers 100, 102 and the suction hole 52 can be expanded, so that the expansion It is possible to prevent a decrease in the amount of refrigerant flowing between the chamber and the outside of the expansion side scroll unit 18, that is, the amount of refrigerant taken into the expansion side scroll unit 18.

  In addition, even if the center tip portions 98 and 96 of the wraps 48 and 46 of the fixed and movable scrolls 44 and 42 are brought into contact with each other as the movable scroll 42 revolves, the first and second expansion chambers 100 and 102 The communication with the suction hole 52 can be blocked, and a central expansion chamber 104 that is completely blocked from the first and second expansion chambers 100 and 102 can be formed in the central portion where the suction hole 52 opens. Accordingly, it is possible to prevent the refrigerant from flowing into the expansion side scroll unit 18 while preventing the refrigerant from leaking from the central expansion chamber 104, so that the expansion efficiency of the refrigerant in the expansion side scroll unit 18 is reduced. Therefore, the reliability of the expansion side scroll unit 18 can be secured and the performance can be improved.

  Further, since the communication groove 106 is recessed in the base surface 44b of the fixed scroll 44 in a range reaching the suction hole 52, the durability of the expansion side scroll unit 18 is impaired by processing the wrap 46 of the movable scroll 42. Therefore, the performance of the expansion scroll unit 18 can be improved while the reliability of the expansion scroll unit 18 is ensured with a simple configuration in which a groove is provided in the fixed scroll 44.

  Furthermore, the communication groove 106 communicates the first expansion chamber 100 and the second expansion chamber 102 immediately before the formation of the central expansion chamber 104, that is, immediately before the end of refrigerant intake, thereby allowing the first expansion chamber 100 and the second expansion chamber 102 to communicate with each other. Since the pressure in the expansion chamber 102 can be equalized, the refrigerant can be taken into the expansion side scroll unit 18 more smoothly, and the expansion efficiency of the refrigerant in the expansion side scroll unit 18 can be further improved.

  The communication groove 106 is formed in a range in which the opening areas of the communication grooves 106 with respect to the first and second expansion chambers 100 and 102 are substantially the same immediately before the formation of the central expansion chamber 104, that is, immediately before the end of refrigerant intake. Is done. As a result, almost the same amount of refrigerant can be taken into the first expansion chamber 100 and the second expansion chamber 102 immediately before the formation of the central expansion chamber 104, that is, immediately before the end of refrigerant intake, so The refrigerant can be taken in more smoothly, and the expansion efficiency of the refrigerant in the expansion-side scroll unit 18 can be further improved.

  Further, the communication groove 106 has a groove width smaller than the width of the central tip portion 96 of the wrap 46 of the movable scroll 42, so that the central tip portion 96 of the wrap 46 communicates with the revolution turning motion of the movable scroll 42. It is prevented from being caught in the groove 106, and the performance can be improved while ensuring the reliability of the expansion side scroll unit 18 more reliably.

  Next, FIGS. 6-8 is the top view which looked at the center part of the expansion side scroll unit 18 which concerns on 2nd Embodiment from the movable scroll 42 side. In addition, the same code | symbol is attached | subjected about the location similar to the said 1st Embodiment, and the description is abbreviate | omitted.

  FIG. 6 shows a state immediately before the formation of the central expansion chamber 104, that is, immediately before the end of the refrigerant intake, in accordance with the revolution turning motion of the movable scroll 42. As is apparent from this drawing, the communication groove of the present embodiment includes a first communication groove (communication path, communication groove) 110 that communicates the first expansion chamber 100 and the suction hole 52, and a second expansion chamber 102 and the suction channel. A second communication groove (communication path, communication groove) 112 that communicates with the hole 52 is formed.

  Specifically, the first communication groove 110 extends from the suction hole 52 toward the first expansion chamber 100 in the shape of a long groove within a range that forms a curve substantially along the revolution turning trajectory of the movable scroll 42. On the other hand, the second communication groove 112 is extended from the suction hole 52 toward the second expansion chamber 102 in the shape of a substantially straight line within the revolution turning trajectory of the movable scroll 42.

  By forming the first and second communication grooves 110 and 112 in such a shape and range, at least a part of the suction hole 52 immediately before the central expansion chamber 104 is formed, that is, immediately before the end of refrigerant intake. Is closed by the central tip 96 of the wrap 46 of the movable scroll 42, the first communication groove 110 is communicated with the first expansion chamber 100, the second communication groove 112 is communicated with the second expansion chamber 102, The first expansion chamber 100 and the second expansion chamber 102 communicate with each other through a slight gap.

  At this time, the first and second communication grooves 110 and 112 have substantially the same opening area of the first communication groove 110 with respect to the first expansion chamber 100 and the opening area of the second communication groove 112 with respect to the second expansion chamber 102. Opened to be the same.

  FIG. 7 shows a state in which the orbiting scroll 42 further revolves from the state shown in FIG. 6 and the central expansion chamber 104 is formed, that is, the refrigerant intake is completed. As is apparent from this figure, the first and second communication grooves 110 and 112 are in contact with the central tip portions 98 and 96 of the wraps 48 and 46 of the fixed and movable scrolls 44 and 42 so that the central expansion chamber 104 is formed. When formed, all of the first and second communication grooves 110 and 112 are formed over a range covered by the wrap 96 of the movable scroll 42.

  FIG. 8 shows a state after the revolution of the movable scroll 42 further proceeds from the state of FIG. 7 and the central expansion chamber 104 is formed. As is clear from this figure, the first and second communication grooves 110 and 112 are not only before and during the formation of the central expansion chamber 104, but also after the central expansion chamber 104 is formed. And the expansion chamber is formed over a range that does not hinder the formation. Specifically, the first and second communication grooves 110 and 112 are formed over a range where the width of each of these grooves is smaller than the width of the central front end portion 96 of the wrap 46 of the movable scroll 42.

  As described above, also in the present embodiment, similarly to the first embodiment, it is possible to prevent the refrigerant from being taken into the expansion side scroll unit 18 while preventing the refrigerant from leaking from the central expansion chamber 104. Therefore, the expansion efficiency of the refrigerant in the expansion side scroll unit 18 can be prevented from being lowered, and the performance of the expansion side scroll unit 18 can be improved while ensuring the reliability.

  Particularly in the case of this embodiment, since the degree of freedom of the shape of the communication groove is increased by configuring the communication groove from the first and second communication grooves 110 and 112, the communication groove is immediately before the formation of the central expansion chamber 104. That is, it can be formed in the ranges opened to the first and second working chambers until the moment immediately before the end of refrigerant intake.

  Specifically, FIG. 9 shows a plan view of the central portion of the expansion-side scroll unit 18 according to the modification of the second embodiment of the present invention as viewed from the movable scroll 42 side when the central expansion chamber 104 is formed. Yes. As is apparent from this figure, the end portion 110a of the first communication groove 110 on the first expansion chamber 100 side is made asymptotic toward the outer wall 98a of the central front end portion 98 of the fixed scroll 44, while the second communication groove 112 The distal end portion 112a on the second expansion chamber 102 side is formed asymptotically toward the inner wall 98b of the central front end portion 98 of the fixed scroll 44. Thus, as compared with the case of the first embodiment, the first communication groove 110 is kept open to the first expansion chamber 100 and the second communication groove 112 is set to the second until the moment immediately before the formation of the central expansion chamber 104. It is possible to keep the expansion chamber 102 open. Therefore, the refrigerant can be taken into the expansion side scroll unit 18 more smoothly, and the expansion efficiency of the refrigerant in the expansion side scroll unit 18 can be further improved.

Although the description of the embodiment of the present invention has been completed above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in each of the above embodiments, the communication groove is formed in the base surface 44b of the fixed scroll 44. However, the present invention is not limited to this. For example, a communication path may be formed in the substrate 42a. Similarly, the expansion efficiency of the refrigerant in the expansion side scroll unit 18 can be improved.

  In addition, the shape of each communication groove in each of the above embodiments is not limited to these shapes. For example, the outer edge of the communication groove may be formed by a polygonal line.

  Further, in each of the above embodiments, the scroll structure of the expansion side scroll unit 18 is not mentioned. However, when the expansion side scroll unit 18 has a symmetric scroll structure, the refrigerant can be smoothly taken into the expansion side scroll unit 18. Therefore, the imbalance between the expansion chambers at the start of the operation of the expansion side scroll unit 18 is corrected, and flapping of the movable scroll 42 with respect to the fixed scroll 44 can be reliably prevented. Therefore, it is possible to improve the performance of the expansion side scroll unit 18 while ensuring the reliability of the expansion side scroll unit 18 more reliably.

  Furthermore, in each of the embodiments described above, the communication groove is formed on the base surface 44b of the fixed scroll 44 of the expansion side scroll unit 18, but this is not limiting, and the base surface 60b of the fixed scroll 60 of the compression side scroll unit 14 is not limited thereto. In this case, the refrigerant discharge amount from the compression side scroll unit 14 can be prevented from decreasing while preventing the refrigerant from leaking from the central compression chamber. Decrease in the compression efficiency of the refrigerant can be prevented, and the performance can be improved while ensuring the reliability of the compression scroll unit 14.

  Finally, in each of the above-described embodiments, the case where the present invention is applied to a compressor-integrated expander has been described. However, the present invention is not limited to this, and the present invention is not limited to this. Needless to say, the present invention is applicable to any fluid machine including a scroll unit.

DESCRIPTION OF SYMBOLS 1 Scroll type fluid machine 4 Expander 14 Compression side scroll unit (scroll unit)
18 Expansion side scroll unit (scroll unit)
42 Movable scroll (movable scroll) of expansion side scroll unit
42a Movable scroll substrate (substrate) of expansion side scroll unit
42b Base surface (base surface) of movable scroll substrate of expansion side scroll unit
44 Fixed scroll of expansion side scroll unit (fixed scroll)
44a Fixed scroll substrate of expansion side scroll unit (substrate)
44b Base surface (base surface) of fixed scroll substrate of expansion side scroll unit
46 Wrap of movable scroll of expansion side scroll unit (wrap)
48 Wrap of fixed scroll of expansion side scroll unit (wrap)
52 Suction hole (communication hole)
58 Movable scroll (movable scroll) of compression side scroll unit
58a Movable scroll substrate (substrate) of compression side scroll unit
58b Base surface (base surface) of movable scroll substrate of compression side scroll unit
60 Fixed scroll (fixed scroll) of compression side scroll unit
60a Fixed scroll substrate of compression side scroll unit (substrate)
60b Base surface (base surface) of fixed scroll substrate of compression side scroll unit
62 Scroll of movable scroll of compression side scroll unit (wrap)
64 Compression scroll unit fixed scroll wrap (wrap)
72 Discharge hole (communication hole)
96 Central tip (central tip) of the movable scroll wrap of the expansion side scroll unit
96a The outer wall (outer wall) of the center tip of the movable scroll wrap of the expansion side scroll unit
96b Inner wall (inner wall) at the center tip of the movable scroll wrap of the expansion side scroll unit
98 Center tip (center tip) of fixed scroll wrap of expansion side scroll unit
98a Outer wall (outer wall) at the center tip of the fixed scroll wrap of the expansion side scroll unit
98b Inner wall (inner wall) at the center tip of the fixed scroll wrap of the expansion side scroll unit
100 first expansion chamber (first working chamber)
102 Second expansion chamber (second working chamber)
104 Central expansion chamber (working chamber)
106 Communication groove (communication passage)
110 First communication groove (communication path, communication groove)
112 Second communication groove (communication path, communication groove)

Claims (8)

Each of the bases of each substrate is composed of fixed and movable scrolls each having a spiral wrap facing each other, and the movable scroll is revolved around the axis of the fixed scrolls to make the fixed and movable scrolls. A scroll unit that forms a working chamber for the working fluid between the laps,
A communication hole formed through the central portion of the substrate of the fixed scroll and communicating the working chamber and the outside of the scroll unit;
A first working chamber defined by an outer wall of a central tip portion of the wrap of the fixed scroll and an inner wall of a central tip portion of the wrap of the movable scroll;
A second working chamber defined by an inner wall of the central tip of the wrap of the fixed scroll and an outer wall of the central tip of the wrap of the movable scroll;
When at least a part of the communication hole is closed by the central front end portion of the wrap of the movable scroll in accordance with the revolving orbiting motion of the movable scroll, the first and second working chambers, the communication hole, A communication path that blocks communication between the first and second working chambers and the communication hole when the central tip portions of the wraps of the fixed and movable scrolls are in contact with each other. A scroll type fluid machine comprising: The communication path is a communication groove that is recessed in a range reaching the communication hole on the base surface of the fixed scroll,
The communication groove is configured such that when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll in accordance with a revolving orbiting motion of the movable scroll, at least a part of the communication groove is When the central front ends of the fixed and movable scroll laps are in contact with each other, the communication grooves are all covered with the movable scroll by the wraps. The scroll type fluid machine according to claim 1, wherein the scroll type fluid machine is formed within a range.   The communication groove communicates the first working chamber and the second working chamber when at least a part of the communication hole is blocked by the central tip of the wrap of the movable scroll. The scroll type fluid machine according to claim 2.   The communication groove includes a first communication groove that communicates the first working chamber and the communication hole when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll; The scroll fluid machine according to claim 2, comprising a second communication groove for communicating the second working chamber and the communication hole.   The communication groove has an opening area of each of the communication grooves with respect to the first and second working chambers when at least a part of the communication hole is closed by the central tip of the wrap of the movable scroll. 3. The scroll type fluid machine according to claim 2, wherein the scroll type fluid machine is formed in a range that is substantially the same.   The scroll type fluid machine according to any one of claims 3 to 5, wherein the scroll unit has a symmetrical scroll structure.   3. The scroll fluid machine according to claim 2, wherein the communication groove has a groove width smaller than a width of the central tip portion of the wrap of the movable scroll.   The scroll fluid machine according to claim 1, wherein the scroll fluid machine is an expander having the working chamber as an expansion chamber.

Images