JP2013139714A - Scroll compressor - Google Patents

Scroll compressor Download PDF

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Publication number
JP2013139714A
JP2013139714A JP2011289555A JP2011289555A JP2013139714A JP 2013139714 A JP2013139714 A JP 2013139714A JP 2011289555 A JP2011289555 A JP 2011289555A JP 2011289555 A JP2011289555 A JP 2011289555A JP 2013139714 A JP2013139714 A JP 2013139714A
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Japan
Prior art keywords
pressure
space
oil supply
valve
passage
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JP2011289555A
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Japanese (ja)
Inventor
Kenichi Sata
健一 佐多
Yoshitaka Shibamoto
祥孝 芝本
Ryuzo Sotojima
隆造 外島
Sachihiro Inada
幸博 稲田
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Daikin Industries Ltd
ダイキン工業株式会社
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Priority to JP2011289555A priority Critical patent/JP2013139714A/en
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Abstract

In a scroll compressor, mechanical loss between a fixed scroll and a movable scroll is reduced.
A scroll compressor (1) has a back pressure space (55) (an inner space (56) and an outer space (57)) for pressing the movable scroll (31) against the fixed scroll (21). A back pressure adjusting mechanism (100) for adjusting the pressure in the outer space (57) is provided. The back pressure adjustment mechanism (100) is configured so that the pressure in the outer space (57) is adjusted to a predetermined pressure, and the predetermined pressure increases as the rotational speed of the drive shaft (80) increases.
[Selection] Figure 1

Description

  The present invention relates to a scroll compressor, and particularly relates to measures for reducing mechanical loss between a fixed scroll and a movable scroll.
  Conventionally, scroll compressors are known. For example, a scroll compressor disclosed in Patent Document 1 includes a fixed scroll fixed in a casing, and a movable scroll that meshes with the fixed scroll and has a drive shaft connected to the back side. In this scroll compressor, when the drive shaft is rotated, the movable scroll turns. And at the time of the turning, the fluid is sucked into the compression chamber formed between the two scrolls, and the fluid is compressed in the compression chamber.
  Further, in this scroll compressor, during the compression operation, the movable scroll is pressed against the fixed scroll by making the back pressure space formed between the movable scroll and the housing on the back side relatively high. By doing so, separation of the movable scroll is suppressed, and fluid is prevented from leaking from the compression chamber and reducing the compression efficiency.
JP 2003-97458 A
  In conventional scroll compressors, the pressure in the back pressure space is increased in accordance with the high-speed rotation that requires high pressing force in order to prevent the compression efficiency from decreasing due to the separation of the movable scroll under all operating conditions (rotation speed conditions). It was set to. For this reason, there is a problem that the movable scroll becomes excessively pressed during low-speed rotation that does not require much pressing force, and mechanical loss due to friction between the fixed scroll and the movable scroll increases.
  The present invention has been made in view of such points, and by reducing the pressing force of the movable scroll under all operating conditions (rotational speed conditions), the mechanical loss between the fixed scroll and the movable scroll is reduced. The purpose is to do.
  A first invention is provided in a casing (10), and is engaged with a compression mechanism (20) having a fixed scroll (21) and a movable scroll (31) meshing with each other, and the movable scroll (31). A housing (80) that drives the compression mechanism (20) and a rear side of the movable scroll (31) that forms a back pressure space (55) between the movable scroll (31) and the drive shaft (80). 50) and the movable scroll (31) and the housing (50), and the back pressure space (55) is divided into an inner space (56) and an outer space (56) having a lower pressure than the inner space (56). 57). The present invention is intended for a scroll compressor including an annular seal member (54) partitioned into 57). The scroll compressor (1) is configured such that the pressure in the outer space (57) is adjusted to a predetermined pressure, and the predetermined pressure increases as the rotational speed of the drive shaft (80) increases. And a back pressure adjusting mechanism (100).
  In the first aspect of the invention, the predetermined pressure in the outer space (57) increases as the rotational speed increases. Therefore, the pressing force of the movable scroll (31) generated by the pressure in the outer space (57) and the pressure in the inner space (56) increases as the rotation speed increases, and is optimized for each rotation speed.
  In a second aspect based on the first aspect, the drive shaft (80) is configured such that the drive shaft (80) supplies oil in the casing (10) to the engagement portion (34) with the movable scroll (31). ) And an oil supply pump (85) for supplying oil in the casing (10) to the oil supply passage (90) by rotation of the drive shaft (80), and the back pressure adjusting mechanism (100) , Formed in the end plate (32) of the movable scroll (31), the outer space (57) and the low pressure space (25) in the casing (10) are communicated, and the outer space (57) is decompressed. Pressure reducing passage (102), a cylinder chamber (110) provided in the middle of the pressure reducing passage (102) and communicating with the oil supply passage (90), and provided in the cylinder chamber (110), the pressure reducing passage A piston (120) for opening and closing (102), and the piston (120) receives the pressure of the outer space (57) in the valve opening direction. The pressure of the oil supply passage (90) is received in the valve closing direction, and the pressure reduction passage (102) is opened when the pressure of the outer space (57) becomes higher than the predetermined pressure. To do.
  In the second aspect of the invention, the refrigerant and oil flow from the inner space (56) to the outer space (57) having a lower pressure than the inner space (56) during the compression operation, so the pressure in the outer space (57) gradually increases. To do. When the pressure becomes higher than the predetermined pressure, in the back pressure adjustment mechanism (100), the force in the valve opening direction due to the pressure in the outer space (57) becomes larger than the force in the valve closing direction, and the piston (120) Opens the decompression path (102). Then, the outer space (57) is depressurized and held at a predetermined pressure.
  Further, when the rotational speed of the drive shaft (80) increases, the back pressure adjusting mechanism (100) increases the amount of oil supplied to the oil pump (85) driven by the rotation of the drive shaft (80), and the oil supply path (90) The pressure in the valve closing direction increases due to the pressure in the oil supply passage (90). For this reason, the force in the valve opening direction required for the piston (120) to open the pressure reducing path (102) increases, and as a result, the pressure (predetermined) in the outer space (57) required to open the pressure reducing path (102). Pressure) increases.
  Thus, in the back pressure adjusting mechanism (100), the piston (120) adjusts the pressure of the outer space (57) to a predetermined pressure, and further, the predetermined pressure is supplied to the oil supply passage (90) by the oil supply pump (85). It is changed using the pressure change.
  According to a third aspect, in the second aspect, the oil supply pump (85) is a positive displacement pump.
  In the third aspect of the invention, since the oil supply pump (85) is a positive displacement pump, the pressure of the oil supply passage (90) at the time of high-speed rotation is likely to be higher and the rotational speed is changed compared to other pumps. The pressure change in the oil supply passage (90) becomes large. Therefore, it becomes easy to control the pressure of the outer space (57) using the pressure change of the oil supply passage (90).
  In a fourth aspect based on the first aspect, the drive shaft (80) is configured to provide a main oil supply passage (supplies for supplying oil in the casing (10) to the engaging portion (34) with the movable scroll (31). 91) and a sub oil supply passage (93) branched in the middle of the main oil supply passage (91), the back pressure adjusting mechanism (100) is provided in the middle of the sub oil supply passage (93), In the pressure regulating valve (130) for reducing the pressure on the terminal side of the auxiliary oil supply passage (93) as the rotational speed of the drive shaft (80) increases, and in the end plate (32) of the movable scroll (31) A decompression path (142) formed to communicate the outer space (57) and the low pressure space (25) in the casing (10) to decompress the outer space (57); and the decompression path (142) And a cylinder chamber (150) communicating with the terminal end of the auxiliary oil supply passage (93), and provided in the cylinder chamber (150) for opening and closing the pressure reduction passage (142). And a spring member (163, 164) that urges the piston (160), and the piston (160) includes the pressure of the outer space (57) and the auxiliary oil supply passage (93). The pressure on the end side is received in the valve opening direction and the urging force of the spring member (163, 164) is received in the valve closing direction so that the pressure reducing path (142) is opened when the pressure in the outer space (57) becomes higher than the predetermined pressure. The machine is characterized by being configured.
  In the fourth aspect of the invention, during the compression operation, refrigerant or oil flows from the inner space (56) into the outer space (57) having a lower pressure than the inner space (56), so the pressure in the outer space (57) gradually increases. To do. When the pressure becomes higher than the predetermined pressure, in the back pressure adjusting mechanism (100), the force in the valve opening direction due to the pressure in the outer space (57) becomes larger than the force in the valve closing direction, and the piston (160) Opens the decompression path (142). Then, the outer space (57) is depressurized and held at a predetermined pressure.
  Further, when the rotational speed of the drive shaft (80) increases, the back pressure adjusting mechanism (100) depressurizes the terminal end side of the auxiliary oil supply passage (93) by the pressure adjustment valve (130), so the auxiliary oil supply passage (93) The force in the valve opening direction due to the pressure on the end side of the valve becomes small. Therefore, the force in the other valve opening direction necessary to open the decompression path (142), that is, the force due to the pressure in the outer space (57) is increased, and as a result, the outer side necessary to open the decompression path (142). The pressure (predetermined pressure) in the space (57) increases.
  Thus, in the back pressure adjusting mechanism (100), the piston (160) adjusts the pressure of the outer space (57) to a predetermined pressure, and further, the predetermined pressure is adjusted to the auxiliary oil supply passage by the pressure adjusting valve (130). The pressure is changed using the pressure change on the terminal side of (93).
  In a fifth aspect based on the fourth aspect, the pressure regulating valve (130) is provided in the valve chamber (131) provided in the middle of the auxiliary oil passage (93) and in the valve chamber (131). And a valve body (132) for changing the opening degree of the auxiliary oil supply passage (93), and the valve body (132) is configured to apply centrifugal force during rotation of the drive shaft (80) to the auxiliary oil supply passage. (93) receiving in the direction of decreasing the opening degree.
  In the fifth aspect of the present invention, when the rotational speed of the drive shaft (80) increases, the centrifugal force of the valve element (132) of the pressure regulating valve (130) increases and the force in the valve closing direction increases, and the auxiliary oil supply path The opening of (93) becomes smaller. Therefore, in the auxiliary oil supply passage (93), the flow rate of the oil flowing out from the pressure regulating valve (130) to the terminal side decreases, and as a result, the pressure on the terminal side decreases. Thus, in the pressure regulating valve (130), the pressure on the terminal side of the auxiliary oil supply passage (93) changes as the centrifugal force of the valve body (132) changes.
  According to the present invention, the predetermined pressure in the outer space (57) is increased as the rotational speed increases. As a result, the pressing force of the movable scroll (31) generated by the pressure in the outer space (57) and the pressure in the inner space (56) can be increased as the rotation speed increases, and can be optimized for each rotation speed. . As a result, mechanical loss due to friction between the fixed scroll and the movable scroll can be reduced.
  According to the second aspect of the invention, the pressure in the outer space (57) is controlled using the oil supply pump (85) that supplies oil by the rotation of the drive shaft (80). When this oil pump (85) is used, the oil supply amount is increased during high-speed rotation to increase the pressure in the oil supply passage (90), while the oil supply amount is decreased during low-speed rotation to reduce the pressure in the oil supply passage (90). This pressure change can be used to automatically change the pressure in the outer space (57). Therefore, it is not necessary to separately provide a regulator or the like to control the pressure in the outer space (57), and the apparatus cost can be reduced.
  According to the third aspect, the oil supply pump (85) is a positive displacement pump. Therefore, it becomes easy to control the pressure of the outer space (57) using the pressure change of the oil supply passage (90), and the controllability of the pressing force can be improved.
  According to the fourth aspect of the invention, the pressure regulating valve (130) is used. By using this pressure regulating valve (130), the pressure on the terminal side of the auxiliary oil passage (93) can be lowered during high speed rotation, while the pressure on the terminal side of the auxiliary oil passage (93) can be increased during low speed rotation. The pressure in the outer space (57) can be automatically changed using this pressure change. Therefore, it is not necessary to separately provide a regulator or the like to control the pressure in the outer space (57), and the apparatus cost can be reduced.
  According to the fifth aspect of the present invention, the valve element (132) that receives centrifugal force in the direction of decreasing the opening of the auxiliary oil passage (93) when the drive shaft (80) rotates is used as the pressure regulating valve (130). I made it. Thereby, the pressure of the outer space (57) communicating with the auxiliary oil supply passage (93) can be automatically changed using the change in the centrifugal force of the valve body (132).
FIG. 1 is an overall configuration diagram of a scroll compressor according to the first embodiment. FIG. 2 is an enlarged view of the vicinity of the end plate of the movable scroll according to the first embodiment. FIG. 3 is an explanatory diagram for explaining the opening and closing operation of the piston according to the first embodiment. FIG. 4 is an explanatory diagram for explaining an opening / closing operation during high-speed rotation of the piston according to the first embodiment. FIG. 5 is an overall configuration diagram of the scroll compressor according to the second embodiment. FIG. 6 is an enlarged view of the vicinity of the end plate of the movable scroll according to the second embodiment. FIG. 7 is an explanatory diagram for explaining the opening and closing operation of the piston according to the second embodiment. FIG. 8 is an explanatory diagram for explaining an opening / closing operation during high-speed rotation of the piston according to the second embodiment. FIG. 9 is an overall configuration diagram of a scroll compressor according to a modification of the second embodiment. FIG. 10 is an overall configuration diagram of a scroll compressor according to another embodiment.
  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.
Embodiment 1 of the Invention
The scroll compressor (1) of this embodiment is connected to a refrigerant circuit (not shown) that performs a refrigeration cycle, for example, and compresses the refrigerant. As shown in FIG. 1, the scroll compressor (1) includes a casing (10), a compression mechanism (20), a housing (50), a motor (60), a lower bearing portion (70), and a drive shaft (80). ing.
  The casing (10) is an airtight container extending in the vertical direction and closed at both ends, the cylindrical body (11), the upper wall (12) fixed to the upper end of the body (11), and The lower wall portion (13) is fixed to the lower end of the body portion (11). A suction pipe (14) that guides the refrigerant in the refrigerant circuit to the compression mechanism (20) is fixed to the upper wall (12). A discharge pipe (15) through which the refrigerant in the casing (10) is discharged to the refrigerant circuit is fixed through the body (11). Moreover, the oil storage part (16) in which oil was stored is formed in the lower wall part (13).
  Inside the casing (10), a compression mechanism (20), a housing (50), a motor (60), and a lower bearing (70) are arranged in order from the top to the bottom. The housing (50) is joined to the inner peripheral surface of the body (11) of the casing (10), and the internal space of the casing (10) is connected to the upper space (17) on the compression mechanism (20) side and the motor (60) side. It is divided into the lower space (18). The drive shaft (80) is arranged in the vertical direction so as to straddle each part.
<Drive shaft>
The drive shaft (80) has a main shaft portion (81), an eccentric portion (82), a counterweight portion (83), and an oil supply passage (90). The eccentric part (82) protrudes upward from the upper end surface of the main shaft part (81), and its axis is eccentric with respect to the axis of the main shaft part (81). The counterweight portion (83) protrudes outward from the side surface of the substantially central portion of the main shaft portion (81), and is configured to achieve a dynamic balance during rotation. The oil supply passage (90) supplies oil from the oil storage part (16) to the boss part (34) (described later), from the lower end surface of the drive shaft (80) to the upper end surface (eccentric part (82)). And a horizontal path extending in the lateral direction from the middle of the vertical path to each bearing portion (51, 71) (described later).
  An oil supply pump (85) is connected to the lower end of the drive shaft (80). The oil supply pump (85) is a positive displacement pump that supplies oil from the oil reservoir (16) to the oil supply passage (90). The suction port opens to the oil storage portion (16), while the discharge port is the oil supply passage ( 90) is connected. The oil supply pump (85) supplies oil by the rotation of the drive shaft (80), and the amount of oil supply increases as the rotational speed of the drive shaft (80) increases.
<Compression mechanism>
The compression mechanism (20) includes a fixed scroll (21) fixed to the upper surface of the housing (50) and a movable scroll (31) meshing with the fixed scroll (21).
  The fixed scroll (21) includes an end plate (22), a spiral (involute) wrap (23) formed on the front surface (the lower surface in FIG. 1) of the end plate (22), and the top of the wrap (23). And an outer peripheral wall portion (24) continuously formed radially outward from the outer peripheral wall. The outer peripheral wall portion (24) is fixed to the upper surface of the housing (50).
  On the other hand, the movable scroll (31) has an end plate (32) and a spiral (involute) wrap (33) formed on the front surface (upper surface in FIG. 1) of the end plate (32). The movable scroll (31) is disposed so that the wrap (33) of the movable scroll (31) meshes with the wrap (23) of the fixed scroll (21). The compression chamber (30) is formed by a space partitioned by the wraps (23, 33) of these two scrolls (21, 31).
  One end of the casing of the suction pipe (14) is connected to the outer peripheral wall (24) of the fixed scroll (21), and the suction chamber (30) that guides the refrigerant sucked from the suction pipe (14) to the compression chamber (30) 25) is formed. The suction chamber (25) has a lower pressure than other places in the casing (10), and constitutes a low pressure space of the present invention.
  In the end plate (22) of the fixed scroll (21), a discharge port (26) is formed in the vicinity of the center. The lower end of the discharge port (26) opens to the discharge position of the compression chamber (30). On the other hand, the upper end of the discharge port (26) opens to a discharge chamber (27) defined in the upper part of the fixed scroll (21). Although not shown, the discharge chamber (27) communicates with the lower space (18) of the casing.
  A cylindrical boss (34) is formed in the end plate (32) of the movable scroll (31) in the vicinity of the center on the back side (lower side in FIG. 1). The eccentric part (82) of the drive shaft (80) is inserted into the boss part (34). Therefore, the oil that has flowed out from the upper end of the oil supply passage (90) is supplied into the boss portion (34). This boss | hub part (34) comprises the engaging part of this invention.
  A part of the back pressure adjustment mechanism (100) is provided inside the end plate (32) of the movable scroll (31). Details of the back pressure adjusting mechanism (100) will be described later.
<housing>
The housing (50) is formed in a substantially cylindrical shape. The housing (50) is formed such that the upper portion of the outer peripheral surface has a larger diameter than the lower portion, and the upper portion of the outer peripheral surface is formed on the inner peripheral surface of the body (11) of the casing (10). It is joined. The housing (50) is formed such that the upper part of the inner peripheral surface has a larger diameter than the lower part. The drive shaft (80) is inserted inside the housing (50), and the upper part of the main shaft part (81) rotates to the upper bearing part (51) which is the lower part of the inner peripheral side of the housing (50). Supported.
  An oil drain passage (58) is formed in the housing (50). The oil drainage passage (58) penetrates the inside and outside of the housing (50), communicates with the space inside the housing (50), and communicates with the lower space (18) outside the housing (50). .
  An annular recess (52) is formed on the upper surface of the housing (50), and an annular ring groove (53) is formed on the inner peripheral side of the recess (52). An annular seal member (54) is fitted in the ring groove (53). The seal member (54) is in contact with both the housing (50) and the movable scroll (31), and has a back pressure space (55) formed between the housing (50) and the movable scroll (31). It is divided into an inner space (56) and an outer space (57).
  The inner space (56) is mainly formed by the space inside the housing (50). Since this inner space (56) communicates with the lower space (18) that is at a high pressure during the compression operation, it is maintained at a high pressure. Further, since this inner space (56) accommodates the boss part (34) of the movable scroll (31), the oil supplied from the upper end of the oil supply passage (90) into the boss part (34) It flows into the space (56).
  On the other hand, the outer space (57) is mainly formed by the space in the recess (52). The outer space (57) has a lower pressure than the inner space (56), and oil and refrigerant leak from the inner space (56) through the gap between the seal member (54) and the upper and lower contact surfaces. The pressure gradually increases. The pressure in these two spaces (56, 57) generates a pressing force that presses the movable scroll (31) against the fixed scroll (21).
<motor>
The motor (60) includes a stator (61) and a rotor (62). The stator (61) is fixed to the body (11) of the casing (10) by shrink fitting or the like. The rotor (62) is disposed coaxially with the stator (61) inside the stator (61). The main shaft portion (81) of the drive shaft (80) is inserted into the rotor (62) so that the rotor (62) and the main shaft portion (81) rotate integrally.
<Lower bearing part>
The lower bearing part (70) includes a cylindrical bearing part (71) and a fixed part that protrudes outward from the outer peripheral surface of the bearing part (71) and is fixed to the body part (11) of the casing (10). (72) The bearing portion (71) rotatably supports the lower portion of the main shaft portion (81).
<Back pressure adjustment mechanism>
As shown in FIG. 2, the back pressure adjusting mechanism (100) includes a pressure reducing path (102), a cylinder chamber (110), and a piston (120).
  The decompression path (102) is formed in the end plate (32) of the movable scroll (31), and communicates the outer space (57) and the suction chamber (25).
  The cylinder chamber (110) is provided in the middle of the decompression path (102), and forms a cylindrical internal space extending in the radial direction (left and right in FIG. 2) of the end plate (32) of the movable scroll (31). Yes. The internal space of the cylinder chamber (110) is divided into an inner peripheral side and an outer peripheral side of the end plate (32) by a partition wall (111), and the inner peripheral side space constitutes the first pressure chamber (112). The space on the outer peripheral side constitutes the second pressure chamber (113). The first pressure chamber (112) communicates with the interior of the boss portion (34) via the boss portion side passage (103), and further communicates with the oil supply passage (90) within the boss portion (34). On the other hand, the second pressure chamber (113) communicates with the outer space (57) via the outer passage (104) and also communicates with the suction chamber (25) via the suction chamber side passage (105). In the second pressure chamber (113), the outer passage (104) opens to the inner wall on the outer peripheral side, and the suction chamber side passage (105) opens to the upper inner wall. The outer passage (104) and the suction chamber side passage (105) constitute a part of the decompression passage (102).
  A through hole (114) penetrating between the two pressure chambers (112, 113) is formed in the partition wall (111). The through hole (114) is for sliding a shaft (121) of a piston (120), which will be described later, and the diameter of the hole is not restricted from the movement of the shaft (121), but from the gap with the shaft (121). The dimensions are set so as to have a gap that allows some oil to leak into the two pressure chambers (113).
  The piston (120) reciprocates in the cylinder chamber (110), and has a shaft (121) extending in the longitudinal direction of the cylinder chamber (110) and a disc shape formed at one end of the shaft (121). The valve body (122). The shaft (121) is inserted into the through hole (114) of the partition wall (111), and the valve body (122) is accommodated in the second pressure chamber (113).
  When the piston (120) moves outward (rightward in FIG. 2), the valve body (122) closes the opening (106) of the outer passage (104) and moves inward (leftward in FIG. 2). Then, the valve body (122) opens the opening (106) of the outer passage (104). By doing so, the decompression path (102) is opened and closed.
  The first pressure chamber (112) has a first spring member (123) having one end in contact with the end surface of the shaft (121) and the other end in contact with the inner wall on the inner peripheral side of the first pressure chamber (112). Is provided. Further, the second pressure chamber (113) is provided with a second spring member (124) having one end in contact with the back surface (left surface in FIG. 2) of the valve body (122) and the other end in contact with the partition wall (111). It has been. These two spring members (123, 124) urge the piston (120) to a position where the opening (106) of the outer passage (104) is closed (valve closing position).
-Driving action-
Next, the operation of the scroll compressor (1) described above will be described.
  When the motor (60) is driven and the drive shaft (80) is rotated, the movable scroll (31) revolves without rotating by the Oldham ring (59), and the compression chamber (30 ) Is contracted toward the center, and the refrigerant sucked from the suction pipe (14) into the compression chamber (30) is compressed. The compressed high-pressure refrigerant is discharged to the discharge chamber (27) through the discharge port (26) of the fixed scroll (21), passes through the lower space (18) of the casing (10), and is discharged. It is discharged from the pipe (15) to the refrigerant circuit.
  Further, when the drive shaft (80) is rotated, the oil supply pump (85) is driven, and the oil in the oil reservoir (16) is supplied to the oil supply passage (90). The oil in the oil supply passage (90) flows upward and flows out from the opening at the upper end surface of the drive shaft (80) into the boss portion (34) of the movable scroll (31). The oil that has flowed out lubricates the sliding surfaces of the boss part (34) and the eccentric part (82), then flows into the inner space (56), and enters the lower space (18) through the oil drainage passage (58). Discharged.
  Since the lower space (18) of the casing (10) becomes high pressure by the refrigerant discharged from the discharge pipe (15), the inner space (56) communicating with the lower space (18) is maintained at high pressure. Further, with the revolving motion of the movable scroll, high-pressure refrigerant or oil leaks from the inner space (56) through the gap between the seal member (54) and the upper and lower contact surfaces to the outer space (57). Further, refrigerant and oil in the middle of compression flow into the outer space (57) through a slight gap (thrust surface) between the movable scroll (31) and the fixed scroll (21), so that the outer space (57) The pressure increases gradually. At this time, the movable scroll (31) is pressed against the fixed scroll (21) by the pressure in the inner space (56) and the pressure in the outer space (57).
  In the back pressure adjusting mechanism (100) of the present embodiment, as shown in FIG. 3, five forces act on the piston (120). In the valve closing direction (right direction in FIG. 3) of the piston (120), the urging force A of the first spring member (123), the urging force B of the second spring member (124), the pressure of the oil supply passage (90) ( A first load C due to the pressure in the first pressure chamber (112) and a second load D due to the pressure in the suction chamber (25) (pressure in the second pressure chamber (113)) are applied. On the other hand, the third load E due to the pressure of the outer space (57) acts in the valve opening direction (leftward in FIG. 3) of the piston (120). The urging force A and the first load C act on the end face of the shaft, the urging force B and the second load D act on the back surface (left surface in FIG. 3) of the valve body (122), and the third load E is the valve body ( 122) on the front surface (right surface in FIG. 3).
  When the force in the valve opening direction is smaller than the resultant force of the four valve closing directions (the state shown in FIG. 3A), the piston (120) is held in the valve closing position and the pressure reducing passage (102) is closed. . In a state where the decompression path (102) is closed, the oil in the outer space (57) does not flow to the suction chamber (25), and the pressure in the outer space (57) continues to rise.
  When the pressure in the outer space (57) becomes higher than a certain pressure (hereinafter referred to as the opening pressure) and the force in the valve opening direction exceeds the resultant force in the four valve closing directions (see FIG. 3 (b)). State), the piston (120) moves in the valve opening direction, and the pressure reducing path (102) opens. In a state where the decompression path (102) is open, oil flows from the outer space (57) to the suction chamber (25), and thus the outer space (57) is decompressed. When the pressure in the outer space (57) becomes equal to or lower than the open pressure, the piston (120) moves to the valve closing position again, and the pressure reducing path (102) is closed (state shown in FIG. 3 (a)). Thus, the outer space (57) is maintained at an open pressure.
  Further, when the rotational speed of the drive shaft (80) increases, the back pressure adjusting mechanism (100) increases the amount of oil supplied to the oil supply pump (85) and increases the pressure in the oil supply passage (90). And the 1st load C by the pressure of an oil supply path (90) increases (state of Fig.4 (a)), and the resultant force of a valve closing direction increases. Therefore, the force (third load E) in the valve opening direction required for the piston (120) to open the pressure reducing path (102) becomes large (the state shown in FIG. 4B). As a result, the pressure reducing path (102) The pressure (opening pressure) in the outer space (57) necessary for opening the door increases.
  Thus, in the back pressure adjustment mechanism (100) of the present embodiment, the pressure in the outer space (57) can be held at the open pressure, and the open pressure can be increased as the rotational speed increases. In this back pressure adjusting mechanism (100), the open pressure can be adjusted by changing the amount of oil supplied to the oil pump (85) and the force acting on the piston (160). Therefore, if the opening pressure is adjusted so that the pressure in the outer space (57) becomes a predetermined pressure at each rotation speed, the movable scroll (31) is driven by the pressure in the inner space (56) and the pressure in the outer space (57). The pressing force can be optimized for each rotational speed while increasing with increasing rotational speed.
-Effect of Embodiment 1-
According to this embodiment, the pressure in the outer space (57) is maintained at a predetermined pressure, and the predetermined pressure is increased as the rotational speed is increased. Thereby, the pressing force of the movable scroll (31) generated by the pressure in the outer space (57) and the pressure in the inner space (56) can be increased with the increase in the number of rotations and optimized for each number of rotations. it can. As a result, mechanical loss due to friction between the fixed scroll and the movable scroll can be reduced.
  Furthermore, according to the present embodiment, the oil supply pump (85) driven by the rotation of the drive shaft (80) is used. When this oil pump (85) is used, the oil supply amount is increased during high-speed rotation to increase the pressure in the oil supply passage (90), while the oil supply amount is decreased during low-speed rotation to reduce the pressure in the oil supply passage (90). The pressure in the outer space (57) can be automatically changed using the pressure change in the oil supply passage (90). Therefore, it is not necessary to separately provide a regulator or the like to control the pressure in the outer space (57), and the apparatus cost can be reduced.
  Furthermore, according to this embodiment, since the oil supply pump (85) is a positive displacement pump, the pressure change in the oil supply passage (90) can be increased as compared with other pumps. Therefore, it becomes easy to control the pressure of the outer space (57) using the pressure change of the oil supply passage (90), and the controllability of the pressing force can be improved.
<Modification of Embodiment 1>
In the first embodiment, the oil supply pump (85) is a positive displacement pump. However, the oil supply pump (85) only needs to suck the oil in the oil reservoir (16) and supply it to the oil supply passage (90), and may be a differential pressure pump or a centrifugal pump, for example.
<< Embodiment 2 of the Invention >>
The second embodiment is obtained by changing the method for changing the opening pressure of the piston in the first embodiment. Specifically, in the first embodiment, the opening pressure is changed using the pressure change in the oil supply passage (90) by the oil supply pump (85). Instead, in the second embodiment, as shown in FIG. 5, the open pressure is changed by using the pressure change on the terminal end side of the auxiliary oil passage (93) by the pressure adjusting valve (130).
  In the second embodiment, a main oil supply passage (91) and a sub oil supply passage (93) are formed inside the drive shaft (80).
  The main oil supply passage (91) supplies oil from the oil reservoir (16) to the boss portion (34), opens to the lower end surface of the drive shaft (80), and is eccentric in the boss portion (34). It opens to the upper end surface and the outer peripheral surface of the part (82). The main oil supply passage (91) is connected to the oil supply pump (85), which is a differential pressure pump, on the lower end surface side of the drive shaft (80). The main oil supply passage (91) communicates with an oil supply groove (36) formed between the fixed scroll (21) and the movable scroll (31) on the upper end surface side of the eccentric portion (82). Specifically, an oil supply passage (37) that connects the boss portion (34) and the oil supply groove (36) is formed in the end plate (32) of the movable scroll (31). Therefore, the oil supplied to the main oil supply passage (91) by the oil supply pump (85) is supplied to the oil supply groove (36) through the oil supply passage (37).
  The auxiliary oil supply passage (93) branches from the main oil supply passage (91) at a substantially central portion of the drive shaft (80), and extends toward the boss portion (34) through the counterweight portion (83). Specifically, the auxiliary oil supply passage (93) includes a first horizontal passage (94) extending from the branch point with the main oil supply passage (91) in the protruding direction (lateral direction) of the counterweight portion (83), and the first A first upper path (95) extending upward from the end of the horizontal path (94). Further, a second lateral path (96) extending laterally from the end of the first upper path (95) toward the center of the drive shaft (80), and an end of the second lateral path (96) in the main shaft portion (81). And a second upper passage (97) connected to a boss portion side passage (145) (described later) at the end.
  In the second embodiment, the back pressure adjusting mechanism (100) includes a pressure adjusting valve (130), a pressure reducing path (142), a cylinder chamber (150), and a piston (160).
  The pressure regulating valve (130) includes a valve chamber (131), a ball valve (132), and a spring member (133). The valve chamber (131) is provided in the middle of the second lateral path (96) and forms a columnar internal space extending in the lateral direction. The ball valve (132) changes the opening degree of the opening (134) on the outer peripheral side (left side in FIG. 5) of the second lateral passage (96) in the valve chamber (131). Is configured. When the drive shaft (80) rotates, the ball valve (132) receives centrifugal force in a direction (valve closing direction) in which the opening degree of the opening (134) on the outer peripheral side of the second lateral path (96) is reduced. One end of the spring member (133) is fixed to the inner wall surface on the inner peripheral side (right side in FIG. 5) of the valve chamber (131), and the other end is fixed to the ball valve (132).
  As shown in FIG. 6, the decompression path (142) is formed in the end plate (32) of the movable scroll (31) and communicates the outer space (57) and the suction chamber (25).
  The cylinder chamber (150) is provided in the middle of the decompression path (142), and forms a cylindrical internal space extending in the radial direction of the end plate (32) of the movable scroll (31). The internal space of the cylinder chamber (110) is divided into three by two partition walls (151 and 152), the inner circumferential space constitutes the first pressure chamber (153), and the middle space is the second pressure chamber. (154), and the outer peripheral space constitutes a third pressure chamber (155). The first pressure chamber (153) communicates with the suction chamber (25) via the suction chamber side passage (143). The second pressure chamber (154) communicates with the outer space (57) through the outer passage (144). The suction chamber side passage (143) and the outer passage (144) constitute a part of the decompression passage (142). The third pressure chamber (155) communicates with the inside of the boss portion (34) through the boss portion side passage (145), and further, at the end of the auxiliary oil supply passage (93) in the boss portion (34). It is connected.
  A first through hole (156) is formed in the first partition wall (151) between the first pressure chamber (153) and the second pressure chamber (154). The first through-hole (156) communicates the first pressure chamber (153) and the second pressure chamber (154) in a state where a shaft (161) of a piston (160) described later is inserted. Is larger than the shaft diameter of the shaft (161). Furthermore, a second through hole (157) is formed in the second partition wall (152) between the second pressure chamber (154) and the third pressure chamber (155). The second through hole (157) is for inserting and sliding the shaft (161), and the hole diameter does not restrict the movement of the shaft (161), and the second pressure from the gap with the shaft (161). The dimensions are set so that there is a gap enough to allow some oil to leak into the chamber (154).
  The piston (160) reciprocates in the cylinder chamber (150) and has a shaft (161) extending in the longitudinal direction of the cylinder chamber (150) and a disc shape formed at one end of the shaft (161). Valve body (162). The shaft (161) is inserted into each of the two through holes (156, 157), and the valve body (162) is accommodated in the first pressure chamber (153). When the piston (160) moves outward (rightward in FIG. 6), the valve body (162) closes the first through hole (156) and moves inward (leftward in FIG. 6). The body (162) opens the first through hole (156). By doing so, the decompression path (142) is opened and closed.
  Further, one end of the first pressure chamber (153) is in contact with the front surface (left surface in FIG. 6) of the valve body (162), and the other end is in contact with the inner wall surface on the inner peripheral side of the first pressure chamber (153). A first spring member (163) is provided. Further, the third pressure chamber (155) is provided with a second spring member (164) having one end in contact with the end surface of the shaft (161) and the other end in contact with the inner wall on the outer peripheral side of the third pressure chamber (155). It has been. These two spring members (163, 164) urge the piston (160) to a position (valve closing position) where the valve body (162) closes the first through hole (156).
-Driving action-
In the back pressure adjusting mechanism (100) of the second embodiment, as shown in FIG. 7, five forces act on the piston (160) of the cylinder chamber (150) during the compression operation. In the valve closing direction (right direction in FIG. 7) of the piston (160), the urging force A of the first spring member (163), the urging force B of the second spring member (164), the pressure of the suction chamber (25) ( The first load C due to the pressure of the first pressure chamber (153) acts. On the other hand, in the valve opening direction (leftward in FIG. 7) of the piston (160), the second load D due to the pressure in the outer space (57) (the pressure in the second pressure chamber (154)) and the sub oil supply passage (93 ) Acts on the third load E due to the pressure on the terminal side (pressure in the third pressure chamber (155)). The urging force A and the first load C act on the front surface (left surface in FIG. 7) of the valve body (162), and the second load D acts on the back surface (right surface in FIG. 7) of the valve body (162). The biasing force B and the third load E act on the end surface of the shaft (161).
  When the resultant force of the two valve opening directions is smaller than the resultant force of the three valve closing directions (the state shown in FIG. 7A), the piston (160) has the valve body (162) as the first through hole. (156) is held at the closing position (valve closing position), and the pressure reducing path (142) is closed. When the decompression path (142) is closed, the oil in the outer space (57) does not flow to the suction chamber (25), and the pressure in the outer space (57) continues to rise.
  Then, when the pressure in the outer space (57) becomes higher than a certain pressure (hereinafter referred to as opening pressure) and the resultant force of the two valve opening directions exceeds the resultant force in the three valve closing directions (FIG. 7). (State of (b)), the piston (160) moves in the valve opening direction and opens the pressure reducing path (142). In a state where the decompression path (142) is opened, the suction chamber (25) passes through the outer space (57) through the second pressure chamber (154), the first through hole (156), and the first pressure chamber (153) in this order. Since the oil flows, the outer space (57) is depressurized. When the pressure in the outer space (57) becomes equal to or lower than the open pressure, the piston (160) moves to the valve closing position again, and the pressure reducing path (142) is closed (state shown in FIG. 7 (a)). Thus, the outer space (57) is maintained at an open pressure.
  Further, when the rotational speed of the drive shaft (80) increases, the centrifugal force of the ball valve (132) increases in the pressure regulating valve (130), so that the ball valve (132) is closed (left side in FIG. 5). And the clearance (opening) between the ball valve (132) and the opening (134) of the second lateral passage (96) is reduced. Then, the flow rate of the oil flowing through the pressure regulating valve (130) and flowing into the second upper passage (97) is reduced, and the pressure of the second upper passage (97), that is, the terminal oil supply passage (93) on the terminal side is reduced. The pressure decreases and the third load E decreases (state shown in FIG. 8). Therefore, the force (second load D) in the other valve opening direction required for the piston (160) to open the pressure reducing path (142) is increased, and as a result, the outer side required to open the pressure reducing path (142). The pressure (opening pressure) in the space (57) increases.
  As described above, in the back pressure adjustment mechanism (100) of the second embodiment, the pressure in the outer space (57) can be held at the open pressure, and the open pressure can be increased as the rotational speed increases. In the back pressure adjusting mechanism (100), the opening pressure can be adjusted by changing the opening of the pressure adjusting valve (130) and the force acting on the piston (160). Therefore, if the opening pressure is adjusted so that the pressure in the outer space (57) becomes a predetermined pressure at each rotation speed, the movable scroll (31) is driven by the pressure in the inner space (56) and the pressure in the outer space (57). The pressing force can be optimized for each rotational speed while increasing with increasing rotational speed.
-Effect of Embodiment 2-
According to the second embodiment, the pressure regulating valve (130) is used. By using this pressure regulating valve (130), the pressure on the terminal side of the auxiliary oil passage (93) can be lowered during high speed rotation, while the pressure on the terminal side of the auxiliary oil passage (93) can be increased during low speed rotation. The pressure in the outer space (57) can be automatically changed using this pressure change. Therefore, it is not necessary to separately provide a regulator or the like to control the pressure in the outer space (57), and the apparatus cost can be reduced.
  According to the second embodiment, the pressure regulating valve (130) is provided with a valve body (132) that receives centrifugal force in a direction to reduce the opening of the auxiliary oil passage (93) when the drive shaft (80) rotates. I did it. Thereby, the pressure of the outer space (57) communicating with the auxiliary oil supply passage (93) can be automatically changed using the change in the centrifugal force of the valve body (132).
<Modification of Embodiment 2>
In the second embodiment, the oil supply pump (85) is a differential pressure pump. However, the oil supply pump (85) only needs to suck the oil in the oil reservoir (16) and supply it to the main oil supply passage (91), and may be, for example, a volumetric pump or a centrifugal pump.
  When the centrifugal pump is used, as shown in FIG. 9, the main oil supply passage (91) opens in the outer peripheral surface of the eccentric portion (82) in the boss portion (34), while the sub oil supply passage (93) is the eccentric portion. Open to the upper end surface of (82) and communicate with the boss side passage (145) through a gap between the upper end surface of the eccentric portion (82) and the lower surface of the end plate (32) of the movable scroll (31). May be.
<< Other Embodiments >>
In the said embodiment, the pressure of the outer space (57) is changed using the pressure change of the oil supply path (90) and the sub oil supply path (93). However, the embodiment of the present invention is not limited to this. For example, as shown in FIG. 10, the pressure in the outer space (57) may be changed by an external regulator (173).
  The scroll compressor (1) of this embodiment includes a decompression path (172), a regulator (173), a pressure detector (174), and a pressure controller (175). The decompression path (172) is formed by piping and communicates with the outer space (57) and the suction chamber (25). The regulator (173) is provided in the middle of the decompression path (172), and opens and closes the decompression path (172). The pressure detector (174) detects the pressure in the outer space (57) and outputs the detection result to the pressure controller (175).
  The pressure controller (175) controls opening and closing of the regulator (173). Specifically, the pressure control unit (175) compares the detected pressure in the outer space (57) with a predetermined pressure, and when the pressure in the outer space (57) becomes higher than the predetermined pressure, the valve opening operation is regulated by a regulator ( 173), and when the pressure in the outer space (57) falls below a predetermined pressure, the valve closing operation is commanded to the regulator (173). By doing so, the pressure in the outer space (57) is maintained at a predetermined pressure.
  In the pressure control unit (175), the predetermined pressure differs for each rotation speed, and increases as the rotation speed of the drive shaft (80) increases. Therefore, the pressing force of the movable scroll (31) generated by the pressure in the outer space (57) and the pressure in the inner space (56) can be increased and optimized as the rotational speed increases.
  In the above embodiment, the upper space (17) of the casing (10) is a low pressure dome and the lower space (18) is held at a high pressure, but the type of the scroll compressor (1) is this. Not limited to this, a low-pressure dome that holds both spaces at a low pressure or a high-pressure dome that holds a high pressure may be used.
  As described above, the present invention is useful for the scroll compressor (1) that is connected to the refrigerant circuit that performs the refrigeration cycle and compresses the refrigerant.
10 Casing
20 Compression mechanism
21 Fixed scroll
25 Suction chamber (low pressure space)
31 Moveable scroll
34 Boss part (engagement part)
50 housing
54 Seal member
55 Back pressure space
56 Interior space
57 Outer space
80 Drive shaft
85 Refueling pump
90 Refueling channel
91 Main oilway
93 Secondary oil supply passage
100 Back pressure adjustment mechanism
102 decompression path
110 Cylinder chamber
120 piston
130 Pressure regulating valve
131 Valve chamber
132 Ball valve (valve)
142 Decompression path
150 Cylinder chamber
160 pistons
163,164 Spring member

Claims (5)

  1. A compression mechanism (20) having a fixed scroll (21) and a movable scroll (31) provided in the casing (10) and meshing with each other;
    A drive shaft (80) engaged with the movable scroll (31) to drive the compression mechanism (20);
    A housing (50) disposed on the back side of the movable scroll (31) and forming a back pressure space (55) with the movable scroll (31);
    Arranged between the movable scroll (31) and the housing (50), the back pressure space (55) is divided into an inner space (56) and an outer space (57) having a lower pressure than the inner space (56). A scroll compressor comprising an annular sealing member (54) for partitioning;
    A back pressure adjusting mechanism (100) configured to adjust the pressure of the outer space (57) to a predetermined pressure and to increase the predetermined pressure as the rotational speed of the drive shaft (80) increases; A scroll compressor characterized by that.
  2. In claim 1,
    The drive shaft (80) has an oil supply passage (90) for supplying oil in the casing (10) to an engagement portion (34) with the movable scroll (31),
    An oil supply pump (85) for supplying oil in the casing (10) to the oil supply passage (90) by rotation of the drive shaft (80);
    The back pressure adjustment mechanism (100) is formed in the end plate (32) of the movable scroll (31), and communicates the outer space (57) with the low pressure space (25) in the casing (10). A decompression passage (102) for decompressing the outer space (57), a cylinder chamber (110) provided in the middle of the decompression passage (102) and communicating with the oil supply passage (90), and the cylinder chamber (110 ) And a piston (120) that opens and closes the decompression path (102),
    The piston (120) receives the pressure of the outer space (57) in the valve opening direction and receives the pressure of the oil supply passage (90) in the valve closing direction, and the pressure of the outer space (57) is greater than the predetermined pressure. A scroll compressor characterized by being configured to open the decompression path (102) when it is high.
  3. In claim 2,
    The oil supply pump (85) is a positive displacement pump.
  4. In claim 1,
    The drive shaft (80) includes a main oil supply passage (91) for supplying oil in the casing (10) to an engagement portion (34) with the movable scroll (31), and the main oil supply passage (91). A secondary oil supply passage (93) that branches in the middle,
    The back pressure adjusting mechanism (100) is provided in the middle of the auxiliary oil supply passage (93), and adjusts the pressure on the terminal side of the auxiliary oil supply passage (93) as the rotational speed of the drive shaft (80) increases. A pressure regulating valve (130) to be lowered is formed in the end plate (32) of the movable scroll (31), and the outer space (57) communicates with the low pressure space (25) in the casing (10). A decompression path (142) for decompressing the outer space (57), a cylinder chamber (150) provided in the middle of the decompression path (142) and communicating with the terminal end of the auxiliary oil supply path (93), and the cylinder A piston (160) provided in the chamber (150) for opening and closing the decompression path (142), and a spring member (163,164) for biasing the piston (160),
    The piston (160) receives the pressure of the outer space (57) and the pressure on the terminal end side of the auxiliary oil passage (93) in the valve opening direction, and receives the biasing force of the spring members (163, 164) in the valve closing direction, A scroll compressor characterized in that when the pressure in the outer space (57) becomes higher than the predetermined pressure, the decompression path (142) is opened.
  5. In claim 4,
    The pressure regulating valve (130) includes a valve chamber (131) provided in the middle of the auxiliary oil passage (93) and an opening degree of the auxiliary oil passage (93) provided in the valve chamber (131). And a valve body (132) for changing
    The scroll compressor according to claim 1, wherein the valve body (132) receives a centrifugal force when the drive shaft (80) rotates in a direction to reduce the opening of the auxiliary oil supply passage (93).
JP2011289555A 2011-12-28 2011-12-28 Scroll compressor Pending JP2013139714A (en)

Priority Applications (1)

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JP2011289555A JP2013139714A (en) 2011-12-28 2011-12-28 Scroll compressor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011289555A JP2013139714A (en) 2011-12-28 2011-12-28 Scroll compressor

Publications (1)

Publication Number Publication Date
JP2013139714A true JP2013139714A (en) 2013-07-18

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Family Applications (1)

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Country Link
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20200002471A (en) * 2018-06-29 2020-01-08 엘지전자 주식회사 Scroll compressor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20200002471A (en) * 2018-06-29 2020-01-08 엘지전자 주식회사 Scroll compressor
KR102081339B1 (en) 2018-06-29 2020-02-25 엘지전자 주식회사 Scroll compressor

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