JP2012047082A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem with a conventional scroll compressor, wherein as an operating pressure condition is extended in the range, an operating condition occurs such that an axial gap between a revolving scroll member and a fixed roll is increased, and thus the performance is degraded.SOLUTION: By providing a space inside an end plate of the revolving scroll member to introduce intermediate pressure between suction pressure and back pressure, deformation amount change of a revolving end plate under wide pressure conditions is suppressed, and performance improvement of a scroll compressor under a wide range of conditions can be achieved.

Description

  The present invention relates to a scroll compressor, and more particularly to an apparatus that achieves high efficiency by reducing leakage loss under a wide range of operating conditions.

  Scroll compressors are widely used as compressors for refrigeration cycles of air conditioners and heat pump water heaters that require energy saving. Since air conditioners and heat pump water heaters are operated throughout the year, high performance is required over a wide range of operating conditions for scroll compressors mounted on them.

  In the scroll compressor, a scroll chamber is formed by meshing two scroll members each having a spiral wrap standing on an end plate, and the volume of the compression chamber is changed by fixing one and rotating the other. In order to increase the efficiency, it is necessary to keep the axial gap, which is the main seal portion of the compression chamber, narrow. The axial gap is a gap between one wrap tooth tip and the other lap tooth bottom, that is, the end plate.

  As a method for realizing this, a method is adopted in which discharge pressure or intermediate pressure is applied to the back surface of the orbiting scroll member to be rotated, and the orbiting scroll member is urged toward the fixed scroll member to reduce the gap. A scroll compressor that urges the orbiting scroll member to the fixed scroll member is disclosed in Patent Document 1, for example.

  Furthermore, each scroll member is deformed to reduce the axial gap. As shown in FIG. 2 (fixed scroll member) and FIG. 5 (orbiting scroll member) of Patent Document 1, the deformation mode by the pressure of each scroll member is a deformation in which the axial gap is narrowed. For this reason, as shown in FIG. 10 of Patent Document 1, an initial gap that expands toward the center of the end plate is set.

JP-A-7-19187

  In the above prior art, the axial clearance during actual operation can be narrowed under the operating conditions targeted when the axial clearance is set in advance, but under other operating conditions, the axial clearance is expanded and internal leakage is reduced. There is a problem that the efficiency is decreased due to an increase. In particular, it is not preferable from the viewpoint of the amount of leakage that the gap is enlarged near the center where the pressure is high. The axial gap set at this time is referred to as an axial setting gap.

  An object of the present invention is to provide an efficient scroll compressor.

The object of the present invention is as follows.
In the scroll compressor in which the orbiting scroll member is urged by the pressure of the back pressure chamber to the fixed scroll member, and the orbiting scroll member and the fixed scroll member mesh to form a compression chamber and compress the working fluid.
In the orbiting scroll member,
A space in the end plate is provided inside,
Scroll compression characterized in that a communication passage that connects the compression chamber and the end plate space is disposed so that a pressure higher than the suction pressure and lower than the back pressure chamber is applied to the end plate space. Achieved by machine.

  According to the present invention, a highly efficient scroll compressor can be provided.

The longitudinal cross-sectional view of a scroll compressor. The longitudinal cross-sectional view of a fixed scroll member. Orbiting scroll member. The bottom view of a fixed scroll member. The expanded longitudinal cross-sectional view (FIG. 1Q part) of a back pressure control valve. The both lap cross-sectional view in the turning tooth bottom explaining the pressure distribution between both laps. The bottom perspective view of a turning scroll member, and the perspective view of an Oldham ring. The schematic longitudinal cross-sectional view of the turning scroll member explaining a deformation | transformation of a turning endplate. The longitudinal cross-sectional enlarged view of a back mirror board inner peripheral side (FIG. 3 (a) S part). The longitudinal cross-sectional enlarged view of the outer peripheral part of an end plate, and the lower surface perspective view of a turning scroll member. Relationship between biasing force, pulling force, and pulling force

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent, and each embodiment includes having further effects by appropriately combining as necessary.

Embodiment 1
A first embodiment of the present invention will be described with reference to FIGS. In these embodiments, the compressor diameter is about 10 mm to 1000 mm. Further, FIG. 11 shows the relationship among the urging force, the separating force, and the attracting force described everywhere.

  As shown in FIG. 1, the orbiting movement of the orbiting scroll member 3 is performed by mounting an orbiting bearing 23 fixed to the orbiting scroll member 3 on an eccentric boss portion 6a at the upper end of the rotating shaft 6 and by a motor 7 to be described later. This is realized by turning. Here, the Oldham ring 5 provided between the orbiting scroll member 3 and the stationary frame 4 prevents the orbiting scroll member 3 from rotating.

  The rotating shaft 6 is supported by a main bearing 24 provided integrally with the frame 4 and a sub-bearing 25 provided on the opposite side of the main bearing 24 with the rotor 7a interposed therebetween. The axial direction refers to the direction of the axis of the rotary shaft 6. The direction in which a lap described later stands is also the axial direction. Here, in the center of the rotating shaft 6, an oil supply vertical hole 6 b that is a flow path of oil supplied to each bearing passes. An upper balance 7c and a lower balance 7d for balancing the unbalance of the orbiting scroll member 3 are disposed on the upper and lower portions of the rotor 7a.

  The auxiliary bearing 25 is held by an auxiliary bearing holding member 27 and is attached to the lower frame 35. The sub bearing 25 supplies oil by centrifugal oil supply. The frame 4 and the lower frame 35 are fixedly arranged on the cylindrical casing 8a so that the coaxiality of the main bearing 24 and the sub-bearing 25 fixedly arranged on them is at a desired level. Thereafter, the discharge pipe 55 for discharging the pressurized working fluid to the outside of the compressor is fixedly arranged.

  A bottom casing 8c is mounted and welded to the lower part of the cylindrical casing 8a. An upper casing 8b is mounted and welded to the upper part of the cylindrical casing 8a. As described above, the sealed casing 8 is formed by welding the upper casing 8b on the cylindrical casing 8a and the bottom casing 8c on the lower side.

  A hermetic terminal 85 is fixedly disposed in the upper casing 8b in advance, and a motor wire 7e is connected to the inner side of the hermetic terminal 85. The case pipe 50a is also fixedly arranged in advance, and the suction pipe 50 is fixed to the upper casing 8b after passing through the case pipe 50a. The suction pipe 50 and the case pipe 50a are sealed by brazing.

  Although not specified, oil is sealed in the casing 8 at an appropriate time of the above-described assembly, and the oil storage portion 125 is formed at the bottom of the casing 8.

  In FIG. 2, a fixed scroll member 2 having a fixed end plate 2a and a fixed wrap 2b erected on the fixed end plate 2a as main components is a fixed end plate 2a that is the same surface as a fixed tooth tip surface 2b10 that is a tooth tip surface of the fixed wrap 2b. 1 is fixedly arranged on the frame 4 as shown in FIG. 1 at the outer side of the fixed reference surface 2c of the integrated base plate 2a '.

  FIG. 3A is a longitudinal sectional view of the orbiting scroll member, and FIG. 3B is a top view. In FIG. 3 (a), the orbiting scroll member 3 whose main component is the orbiting end plate 3a and the orbiting wrap 3b standing on the fixed scroll member 2 is meshed with the fixed scroll member 2, and the orbiting scroll member 3 is revolved without rotating. The compression chamber 100 is formed between both scroll members by making it move (FIG. 1).

  In a normal operation state, the orbiting scroll member 3 is biased by the fixed scroll member 2. That is, the attractive force of the orbiting scroll member 3 at this time is upward in FIG. As a result, the turning urging surface 3c, which is the surface on the lap side of the turning outer edge 3e, which is the periphery of the turning end plate 3a, slides while being urged against the fixed reference surface 2c of the fixed scroll member 2. That is, the orbiting urging surface 3c becomes a thrust surface of the orbiting scroll member 3, and a region closer to the center than the outer side portion of the fixed reference surface 2c of the fixed scroll member 2 is a thrust bearing.

  Next, a general operation will be described. First, the flow of the working fluid will be described. The working fluid at the suction pressure flows from the suction pipe 50 through the suction chamber 105 and flows into the compression chamber 100 described above and is pressurized. Here, since the suction chamber 105 corresponding to the compression chamber before being closed is formed around the compression chamber 100 (see FIG. 4), the vicinity of the center of the swivel biasing surface 3c, that is, near the lap, is a suction pressure region. In many cases.

  Thereafter, the working fluid is pressurized in the compression chamber 100 and then discharged from the discharge hole 2 d closer to the center to the fixed back chamber 115 of the fixed scroll member 2. Here, at the time of over-compression, it is also discharged from the bypass valve 22 provided around the discharge hole 2d. Thus, discharge pressure is applied to the back surface of the fixed scroll member 2. Then, the working fluid flows into the entire inside of the casing 8 through the outer peripheral groove 4z of the frame 4, the peripheral groove 7f of the stator, and the through hole 7g. In this way, the inside of the casing 8 becomes a discharge pressure. This is a so-called high pressure chamber compressor. The working fluid in the casing 8 flows out of the compressor from the discharge pipe 55 after the oil contained therein is separated in the compressor.

  Next, the flow of oil will be described. Since a discharge pressure is applied to the oil storage part 125, which is the lower part of the internal space of the casing 8, the oil staying there naturally becomes the discharge pressure. The oil passes from the oil supply piece 80 fixedly arranged at the lower end of the rotary shaft 6 through the oil supply vertical hole 6b, exits from the end facing the back side of the orbiting scroll member, and lubricates the orbiting bearing 23 and the main bearing 24 while lubricating them. It flows into the pressure chamber 110.

  This is because the back pressure chamber 110 is held at a back pressure that is a pressure between the discharge pressure and the suction pressure by the back pressure control valve 26, which will be described later, and therefore between the oil storage portion 125 that is the discharge pressure. This is because differential pressure is generated and oil is sucked up by the differential pressure. At this time, the slewing bearing chamber 120, which is the space between the slewing end plate 3a and the eccentric boss portion 6a and is sealed by the slewing bearing 23, is filled with the oil of the discharge pressure. It becomes a pressure and it becomes a back discharge pressure field.

  The oil that has flowed into the back pressure chamber 110 flows into the suction chamber 105 through a back pressure communication passage 60 (see FIG. 5) in which the back pressure control valve 26 is provided in the middle of communication between the back pressure chamber 110 and the suction chamber 105. . The oil flowing into the suction chamber 105 is transferred to the discharge chamber 95 together with the working fluid while improving the sealing performance of the compression chamber 100, and is discharged from the discharge port 2d to the fixed back chamber 115. Thereafter, the oil is separated from the working fluid and returns to the oil storage unit 125. However, only a part of them flows out of the compressor together with the working fluid.

  Next, the configuration of the back pressure control valve 26 and the back pressure holding operation will be described with reference to FIG. A valve hole 26a is provided in the outer periphery of the back surface of the fixed scroll member 2, a plate-like valve body 26c and a valve spring 26b are inserted therein, and the valve cap 26f is inserted with one end of the valve spring 26b inserted into the spring positioning projection 26d. The back pressure control valve 26 is formed by press-fitting into a valve cap insertion portion 26g having a diameter larger than that of the valve hole 26a. At this time, the valve spring 26b is compressed, and the valve body 26c is pressed against the valve seal portion 26e. As a result, the valve body 26c does not move unless the back pressure rises above the suction pressure to a value (value converted to pressure) obtained by dividing the pressing force by the area of the internal area of the valve seal portion 26e. Accordingly, the back pressure is increased from the suction pressure to a pressure obtained by adding a certain value corresponding to the compression amount of the valve spring 26b at the time of installation.

  Next, the effect of the change in the suction pressure Ps on the orbiting scroll member and the effect of the change in the discharge pressure Pd on the orbiting scroll member will be considered. First, the influence of Ps will be described.

  Theoretically, as described above, the actual back pressure is increased to a pressure at which the added value is slightly larger than the added value. The reason is as follows.

  Since the back pressure control valve 26 serves as an oil passage, the valve body 26c must be separated from the valve seal portion 26e in order to secure the passage. As a result, the compression amount of the valve spring 26b increases by the distance between the valve seal portion 26e and the valve body 26c, and the back pressure increases by an amount corresponding to the increase.

When symbols are defined as follows, the above can be organized by equation (1).
Pb real-Ps> Pb pre-Ps (1)
Ps: Suction pressure
Pd: discharge pressure Pb actual: actual back pressure Pb pre: expected back pressure corresponding to the compression amount of the valve spring

Since the separation distance between the valve seal portion 26e and the valve body 26c decreases as the amount of oil flowing through the back pressure control valve 26 decreases, the relationship (2) is derived.
q is small ⇒ (Pb real-Ps)-(Pb pre-Ps) is small (2)
q: The amount of oil flowing through the back pressure control valve

On the other hand, in the scroll compressor of the present embodiment, the oil flowing through the back pressure control valve 26 is oil that lubricates the slewing bearing 23 and the main bearing 24, and they flow by the differential pressure between the discharge pressure and the back pressure.
For this reason, (3) holds.
Pb actual is large ⇒ (Pd-Pb actual) is small ⇒ q is small (3)

Further, since the back pressure increases when the suction pressure increases, (4) holds.
Ps is large ⇒ Pb is large… (4)

The relationship (5) is derived from these two relationships.
Ps is large ⇒ q is small (5)

For this reason, from the relationship between (5) and (2), the following relationship (6) is established in the scroll compressor of the present embodiment.
Ps is large ⇒ (Pb actual-Ps)-(Pb pre-Ps) is small (6)

  That is, when the suction pressure increases, the differential pressure between the back pressure and the suction pressure decreases.

  The difference between the formula (4) and the formula (6) is as follows.

  Equation (4) only states that the actual Pb increases as Ps increases. Therefore, in the equation (4), when Ps increases, the actual Pb becomes larger than the amount added by the increase amount of Ps, or smaller than the amount added by the increase amount of Ps, or Nothing is said about whether they are the same. That is, it cannot be derived from the equation (4) whether or not (Pb actual−Ps), which is the actual differential pressure between Pb and Ps, increases when Ps increases.

  On the other hand, equation (6) states that (Pb actual−Ps) always decreases when Ps increases.

  The back pressure controlled in this way forms a back pressure region 155 (see FIG. 8) on the outer side of the orbiting back surface 3d, which is the back surface of the orbiting scroll member 3. This serves as an attracting force generating means for attracting the orbiting scroll member 3 to the fixed scroll member 2 together with the above-described rear discharge pressure region 150 (see FIG. 8).

  Next, the influence of Pd will be described. The area of the rear discharge pressure region 150 is determined by a method as described later, and a discharge chamber 95 formed on the front surface side of the swivel end plate 3a, that is, on the back pressure chamber side and the compression chamber side with respect to the back pressure chamber side. The setting position is set to a position where the pulling force originating from the discharge chamber 95 can be offset.

  Next, a method for setting the area of the back surface discharge pressure region 150 to be equal to the area of the discharge chamber 95 formed on the compression end plate 3a on the compression chamber 100 side will be described with reference to FIG.

  The area S (Pd) of the region where the discharge pressure is applied to the swivel end plate 3a on the compression chamber 100 side is in addition to the projected area from the axial direction of the discharge chamber 95 and the laps 2b and 3b forming the boundary of the discharge chamber 95. Assume that it is half the tooth tip area.

  Since the latter is a seal portion between the compression chamber located outside the discharge chamber 95 and the discharge chamber 95, the portion close to the discharge chamber 95 becomes discharge pressure, and the portion close to the outer compression chamber becomes the pressure of the compression chamber. Therefore, it is reasonable to consider that the discharge pressure is equal to the average pressure of the compression chamber. Therefore, the area to which the discharge pressure is applied is half the tooth tip area.

  Since the area S (Pd) of this region changes as the orbiting scroll member 3 revolves, the time average should originally be the area of the rear discharge pressure region, but it is difficult to define and is complicated. As a good approximation and a clear definition, the average value of the maximum value SM and the minimum value Sm of the changing values is used.

Here, an example of the projected area is shown in FIG. This figure shows the moment when the innermost compression chambers A1 and A2 communicate with the discharge chamber A3 at the same time. Assuming immediately after communication,
SM = A1 + A2 + A3
+ K2 + K3 + S2 + S3
+ (K1 + S1) / 2
Is the maximum value SM of the projected area in question. Also, if we consider it just before communication,
Sm = A3 + (K3 + S3) / 2
Thus, the minimum value Sm of the projection area in question is obtained. Therefore,
S (Pd) = (SM + Sm) / 2
It becomes.

  Conventionally, when the upper limit of the pressure in the compression chamber is set to the discharge pressure level by the bypass valve 22 (see FIG. 1) that suppresses overcompression, the separation is performed in a wide operating range, excluding the separation force component originating from the discharge pressure. The suction force for urging the orbiting scroll member 3 to the fixed scroll member 2 at a minimum against the force, that is, the pulling force originating from the suction pressure and the pressure of the compression chamber depending on the suction pressure is It is obtained when a pressure higher than the pressure by a certain value is applied to the orbiting scroll member 3.

In other words, in this embodiment, in order to urge the orbiting scroll member 3 to the fixed scroll member 2 with a minimum urging force in a wide operation range, the back pressure is a pressure higher than the suction pressure by a certain value. It is sufficient to hold it. The values (Pb pre-Ps) appearing at various points in the previous equation are set values that can urge the orbiting scroll member 3 to the fixed scroll member 2 with a minimum urging force in a wide operating range. . The fact that the biasing force is small means that the pulling force is close to the pulling force from the definition of the biasing force. That is, since “urging force = attraction force−separation force”, a small urging force means that the difference between the attraction force and the attraction force is small, and the convex deformation of the swivel end plate 3a is Get smaller. Therefore, in the present embodiment, the following can be said in a wide operation range.
(Pb actual−Ps) − (Pb pre−Ps) is small ⇒The convex deformation of the revolving end plate 3a is small (7)

  Here, the back pressure valve theory will be described. In the case where the upper pressure limit of the compression chamber is set to the discharge pressure level by the bypass valve 22 (see FIG. 1) for suppressing overcompression, the separation force excluding the separation force component originating from the discharge pressure in a wide operating range, that is, The pulling force for biasing the orbiting scroll member 3 to the fixed scroll member 2 at a minimum against the pulling force originating from the suction pressure and the compression chamber pressure depending on the suction pressure is constant from the suction pressure. It can be obtained by applying a pressure (Pb) that is higher by a value to the orbiting scroll member 3.

  With this back pressure valve theory described before the equation (7) and “the force originating from the discharge pressure of the urging force and the separating force cancels out in this embodiment” That is, it can be seen that there is a value (Pb−Ps) that can minimize the biasing force without depending on the discharge pressure Pd. (Pb pre-Ps) in the equation (7) is a set value that can minimize the urging force in a wide operation range.

  Therefore, the Pb actual value that makes (Pb actual-Ps)-(Pb pre-Ps) small is a value close to (Pb pre) that can minimize the urging force. In combination with the fact that the convex deformation of the swivel end plate is small, the equation (7) can be derived.

From (6) and (7),
Ps is large ⇒ Convex deformation of the swivel end plate 3a is reduced (8)
The relationship is derived.

  This is the end of the description of the schematic configuration of the embodiment and the operations associated therewith. Next, the configuration of the orbiting scroll member, which is the central part of the present invention, and the operations related to the configuration are mainly shown in FIGS. This will be described with reference to FIG.

  First, the configuration of the orbiting scroll member 3 will be described. As shown in FIG. 3A, the orbiting end plate 3a of the orbiting scroll member 3 is divided into two, a wrap end plate 3a1 and a rear end plate 3a2 on which the orbiting wrap 3b stands. Here, it is assumed that the slewing bearing support 3p including the entire back discharge pressure region 150 (see FIG. 8) on the swivel back side is integrated with the wrap end plate 3a1. Then, the lap end plate 3a1 and the rear end plate 3a2 are fixed with a screw 3q (see FIG. 7A) at the turning outer side 3e while having an end plate gap which is an axial gap. In addition to screwing, this may be fixed or fixed by screwing, welding, sliding welding or adhesion. The end plate gap is different from the addendum root gap.

  FIG. 7A shows a bottom perspective view of the orbiting scroll member. Here, when the rear end plate 3a2 is fixed, the inner end portion of the rear end plate 3a2 and the inner end portion of the rear end plate 3a2 and the lap end plate 3a1 are attached to the inner end portion of the end plate space 3a2. The space between the slewing bearing support 3p is sealed in a relatively axially movable state (see FIG. 9).

  As described above, the rotating outer side 3e, which is the outer side of the end plate gap, is fixed with the screw 3q, and the inner side is sealed by the end plate space seal 200a, so that the end plate gap is separated from the back pressure chamber 110, and the pressure is different. An end plate space 200 partitioned from the back pressure chamber 110 is formed inside the swivel end plate 3a.

  Here, the end plate space 200 in FIG. 3A and FIG. 8 is exaggerated for ease of explanation, but is actually very thin. The thickness level is such that the inner side portion of the rear end plate 3a2 is not in contact with the wrap end plate 3a1 due to the deformation described later, and is a level of several μm to 100 μm.

  As shown in the figure, the cross section of the end plate space seal 200 a has a U shape that opens to the back pressure chamber 110. That is, it has a cross-sectional shape that is rectangular and has no lower side. As will be described later, the end plate internal pressure that is the pressure in the end plate inner space 200 is set lower than the back pressure that is the pressure in the back pressure chamber, so that the opening 200a1 of the end plate inner space seal 200a is deformed to open. This has the effect of improving the performance. The cross-sectional shape at this time is a trapezoidal shape having a long lower side and no lower side. Further, an inner peripheral projection 3a2a is provided on the inner peripheral side of the rear end panel 3a2. This is to prevent the end plate space seal 200a from jumping out of the gap when the end plate pressure is inadvertently raised above the back pressure.

  Next, a means for setting the internal pressure of the end plate to an intermediate pressure higher than the suction pressure will be described. As shown in FIGS. 3 (a) and 3 (b), a space in the end plate that connects the compression chamber 100 and the end plate space 200 through the lap end plate 3a1 (except for the part reaching the swivel back) is provided. A passage 200b is provided. As shown in FIG. 4, the opening position is such that the trajectory associated with the swiveling motion of the communication opening 200c, which is the outer end of the intra-endplate space communication passage 200b, causes the compression chamber 100 to fade, that is, intermittently communicates. Set to position. In FIG. 4, the orbiting scroll member 3 at a timing when the end plate space communication path 200 b (communication opening 200 c) communicates with the compression chamber 100 is also drawn.

  Specifically, the internal space communication path 200b in the end plate is set so that the inner circle of the ring, which is the locus of the communication opening 200c, does not pass through the compression chamber but is all on the fixed reference plane of the base plate 2a ′. That is, among the compression chambers, the low pressure compression chamber 100a (see FIG. 4) slightly elevated from the suction chamber 105 and the end plate space 200 communicate with each other for a moment at the swivel phase timing in FIG. The level is fixed at the pressure level of the compression chamber shown in FIG. The pressure level of the compression chamber is a value obtained by multiplying the suction pressure by the power of the adiabatic index of the working fluid of the compression chamber volume ratio (compression chamber volume when closed / compression chamber volume).

  That is, the level of the end plate internal pressure is fixed to a constant value multiple of the suction pressure. Further, as will be described later, since the fluctuation synchronized with the rotation of the rotating shaft 6 can be removed from the deformation of the swivel end plate 3a due to the internal pressure of the end plate, the deformation of the swivel end plate 3a is stabilized, the axial gap is stabilized, It has the effect of improving the sealing performance by oil and improving the performance by suppressing leakage.

  This time, the inner space communication passage 200b is set so that the inner circle of the trajectory of the communication opening 200c does not hit the compression chamber, and the outer circle is hung. Moreover, in order to make this internal pressure in the end plate smaller than the back pressure in the entire operating condition, the set position of the end plate space communication path 200b is arranged on the winding end side of the swirl wrap 3b.

  Next, the operation when the orbiting scroll member 3 configured as described above is incorporated in the scroll compressor will be described with reference to FIG.

  The orbiting scroll member 3 has a back pressure region 155 and a central rear discharge pressure region 150 on the outer side of the orbiting back surface 3d, so that an upward force in the figure (the above-mentioned attraction force) is applied, and this operates. Since the downward force accompanying the fluid compression (the above-described pulling force) is exceeded, the fixed scroll member 2 is urged. The position where the biasing force, which is the difference between the pulling force and the pulling force, is applied is 105 parts of the suction chamber formed at the outer side of the region where the swirl wrap 3b is erected mainly due to the pressure relationship.

  That is, as shown in FIG. 8, the orbiting scroll member 3 has an upwardly convex shape as an overall deformation mode, and the orbiting biasing surface 3 c is formed on the outer side of the fixed reference surface 2 c of the fixed scroll member 2. It is energized at the center side. For this reason, the swivel tooth bottom surface 3a10 has an upwardly convex shape as shown by a thick two-dot chain line in the conventional case where there is no space 200 in the end plate, and the tooth tip surface 3b10 of the swirl wrap 3b erected there is the same. It was convex upward.

  In the present embodiment, the end plate space 200 is provided, and the end plate pressure, which is the pressure inside the end plate space, is changed to an intermediate pressure lower than the back pressure but higher than the suction pressure by the above-described means. Convex deformation at the bottom can be suppressed. The reason for this will be described next.

  Since the discharge chamber 95 is formed on the front surface of the central portion of the wrap end plate 3a1 while changing the area in accordance with the rotational phase of the rotary shaft 6, the force in a direction to dent the central portion of the wrap end plate 3a1. Will be applied. However, as described above, the back surface discharge pressure region 150 having an area equivalent to the average area of the phase angle of the discharge chamber 95 is provided on the back surface of the central portion of the wrap end plate 3a1, so that the wrap by the discharge pressure of the discharge chamber 95 is provided. The force in the direction of denting the central portion of the end plate 3a1 is almost canceled. As a result, it can be considered that the front surface of the wrap end plate 3a1 is in a state where only the suction pressure and the pressure of the compression chamber 100 depending on the suction pressure are applied.

  On the other hand, the end plate internal pressure, which is the pressure applied to the back surface of the wrap end plate 3a1, is an intermediate pressure lower than the back pressure, so that there is no end plate space and the end plate has a larger thickness and higher rigidity than in the conventional case. The amount of downward deflection increases.

  As a result, as shown in FIG. 8, the swiveling tooth bottom surface 3a10 can be displaced downward rather than the thick two-dot chain line showing the conventional tooth bottom surface, and the deformation of the end plate can be controlled to a shape close to a plane. Become. Further, the tooth tip surface 3b10 of the swirl wrap 3b standing on the end plate approaching the plane can also be brought close to the plane. This eliminates the need for step processing and slope processing on the tooth tips and tooth bottoms of the scroll members 2 and 3 for the axial setting gap, which is necessary in the past, and has the effect of reducing processing costs.

  The back end plate 3a2 is subjected to back pressure on its back surface, and an end plate internal pressure that is lower than the back pressure is applied to the upper surface of the opposite surface, so that the inner side portion (near the center) rises as shown in FIG. However, since the inner side portion of 3a2 is separated from the turning bearing support portion 3p integrated with the lap end plate 3a1, the back pressure does not displace the wrap end plate 3a1 upward, and the flatness of the turning tooth bottom surface 3a10 is increased. Will not be reduced. Further, the inner space of the end plate inner space 200a and the back pressure chamber 110 can be reliably secured by the end plate inner space seal 200a because the inner periphery of the swivel bearing support portion 3p and the rear end plate 3a2 is relatively movable in the axial direction. Can be partitioned. High flatness of the swivel tooth bottom surface 3a10 and the swivel tooth tip surface 3b10 is realized under a certain pressure condition in which the deformation of the swivel end plate 3a is controlled.

  As described above, in the present embodiment, this high flatness can be maintained even when the pressure condition is shifted to a different pressure condition. The reason is shown below.

First, consider the case where the discharge pressure changes. As described above, since the back discharge pressure region 150 having the same area as the discharge pressure region applied to the front side of the swivel mirror plate 3a is provided on the swivel back surface 3d, these cancel each other and are substantially discharged onto the swivel mirror plate 3a. It has a form that does not apply pressure.
For this reason, even if the discharge pressure of the operating conditions is changed, the deformation of the swivel end plate 3a does not change, so that the axial gap does not change and a narrow state can be maintained.

Next, consider a case where the suction pressure changes. From the previous consideration, in the present embodiment, the following relationship (8) is established.
High suction pressure ⇒ Decreasing convex deformation of swivel end plate 3a (8)

On the other hand, the end plate internal pressure in the space in the swivel end plate is a constant value multiple of the suction pressure, so that the end plate internal pressure increases as the suction pressure increases. Then, since the space in the swivel end plate expands, the convex deformation of the swivel end plate 3a is increased. That is, the following relationship is established.
High suction pressure ⇒ Increased convex deformation of swivel end plate 3a (9)

  Actually, when the suction pressure increases, the opposite (8) and (9), which are opposite to the change, occur at the same time.

  As described above, according to this embodiment, even if the discharge pressure and the suction pressure are changed, the amount of deformation of the swivel end plate 3a does not change. be able to. As a result, the axial setting gap adjusted to a certain pressure condition becomes an appropriate value in a wide operation range, and leakage can be suppressed under a wide operation condition, and a highly efficient scroll compressor can be provided.

So far, only pressure deformation has been considered, but in the actual case, thermal deformation also overlaps it.
For this reason, it is possible to further increase the efficiency by setting the axial clearance in consideration of thermal deformation.

  Here, normally, a straight groove is provided on the orbiting back surface 3d as constituting a straight pair with the Oldham ring 5, but if it is desired to further increase the strength of the rear end plate 3a2, the orbiting scroll is reversed. A rotating Oldham protrusion 3x, which is a linear protrusion, is provided on the back surface of the member 3. FIG. 7B shows a perspective view of the Oldham ring.

  Accordingly, the Oldham ring 5 is provided with an Oldham groove 5x together with an Oldham protrusion 5y that forms a straight pair with the frame 4. At this time, a reinforcing protrusion 5x1 is provided on the back side of the Oldham groove 5x in order to maintain the rigidity of the Oldham ring 5.

If it is set as this structure, thickness can be suppressed rather than the normal Oldham ring provided with the processus | protrusion on the upper and lower sides, and the effect which can suppress the dimension of a compressor will be acquired. In addition, since the mass of the Oldham ring 5 can be reduced, there is an effect of reducing vibration and noise generated by the reciprocating motion of the Oldham ring 5.
Further, since the turning Oldham projection 3x serves as a rib of the rear end panel 3a2, there is an effect that the rigidity of the rear end panel 3a2 can be increased.

  Further, the end plate ring groove may be provided on the turning urging surface 3c so that the end plate is thicker than the rear end plate 3a2.

Further, as described above, the internal pressure of the end plate becomes substantially constant, but this makes it possible to eliminate the re-expansion loss of the working fluid through the end plate inner space 200, and to avoid the performance degradation associated therewith.
Actually, a slight pressure change occurs because of communication in a limited turning motion section. However, as described above, since the volume of the end plate space 200 is extremely small, the re-expansion loss due to the pressure change is negligible.

  Furthermore, in this time, the end plate space communication path 200b is set so that the inner circle of the path of the communication opening 200c does not hang on the compression chamber, and the outer circle hangs. However, the present invention is not limited to this, and the communication opening 200c is not limited thereto. Although the inner circle of the trajectory is applied to the low-pressure compression chamber 100a, it is of course possible to reduce the diameter of the communication opening 200c and reduce the width of the ring that is the trajectory. As a result, even if the position of the communication opening 200c is displaced, the variation in the amount of working fluid flowing through the communication opening 200c is small, and the variation in re-expansion loss is small. .

[Embodiment 2]
Next, a scroll compressor according to a second embodiment of the present invention will be described with reference to an enlarged longitudinal sectional view of the outer periphery of the end plate in FIG. 10A and a bottom perspective view of the orbiting scroll member in FIG. To do.

  This 2nd Embodiment is the same as that of 1st Embodiment except the point which integrates the back side of the turning outer periphery part 3e to the lap | wrap end plate 3a1. Due to this difference, since the outer periphery of the rear end plate 3a2 is press-fitted or shrinked or cooled into the inner periphery of the outer side rear surface portion 3ae of the wrap end plate 3a1, the both are fixed, so that the processing cost can be reduced.

  Here, in order to prevent the rear end plate 3a2 from rotating, the single screw 3r is used as a rotation stopper, but it may be omitted if an interference fit amount can be secured. Although the thickness of the rear end plate 3a2 is reduced and recessed from the back surface of the outer side back surface portion 3ae to secure δ, the swivel back surface 3d and the frame 4 are swiveled as parameters for determining whether or not the operation is started. It is easy to manage the gap with the bed surface (not shown), that is, the back gap, and the assembly cost can be reduced. This is because the thickness of the rear end plate 3a2 is irrelevant to the back gap, and the only dimension that must be managed on the swivel end plate side is the thickness of the turning outer side 3e of the wrap end plate 3a1.

2 fixed scroll member 2a fixed end plate 2a 'base plate 2c fixed reference surface 2a10 fixed tooth bottom surface 2b fixed wrap 2b10 fixed tooth tip surface 3 orbiting scroll member 3a orbiting end plate 3a1 wrap end plate 3a2 rear end plate 3a10 orbiting tooth bottom surface 3b orbiting wrap 3b10 orbiting tooth Front surface 3c Swing urging surface 3d Swing back surface 3e Swing outer side 3ae Outer side back 3p Swing bearing support 3x Swing Oldham protrusion 4 Frame 5 Oldham ring 6 Rotating shaft 22 Bypass valve 23 Swing bearing 26 Back pressure control valve 60 Back Pressure communication passage 95 Discharge chamber 100 Compression chamber 105 Suction chamber 110 Back pressure chamber 115 Fixed back chamber 120 Swivel bearing chamber 150 Back discharge pressure region 155 Back pressure region 200 End plate space 200a End plate space seal 200b End plate space communication passage 200c Communication opening Part

Claims (6)

An orbiting scroll member having an end plate and a spiral wrap standing on the end plate and orbiting in a plane perpendicular to the axial direction, which is the standing direction, and an end plate and the orbiting scroll having the spiral wrap standing on the end plate The fixed scroll member meshed with the member, and the pulling force in the direction of separating the orbiting scroll member from the fixed scroll member due to the pressure of the working fluid in the compression chamber formed by meshing these scroll members The revolving end plate, which is the end plate of the revolving scroll member, is integrated with the fixed end plate, which is the end plate of the fixed scroll member, and is biased to the base plate which is substantially the same surface as the tooth tip of the fixed wrap which is the wrap of the fixed scroll member. An attraction force adding means for generating an attraction force applied to the orbiting scroll member, and an intake fluid that introduces a working fluid into the compression chamber and becomes a suction pressure. In a system with scroll compressor provided with a discharge system comprising a derived discharge pressure outside the pressurized working fluid in the compression chamber,
The attraction force adding means includes a rear discharge pressure region in which discharge pressure is introduced and an intermediate pressure between suction pressure and discharge pressure on the orbiting rear surface on the opposite side of the fixed scroll member in the orbiting end plate which is the end plate of the orbiting scroll member. Formed by the back pressure region that introduced the back pressure,
The rear discharge pressure region is a projection of the area as viewed from the axial direction of the discharge chamber, which is a region that communicates with the discharge system and is sandwiched between the two end plates at the lap center end that is the start of winding of the wrap. The value between the maximum value and the minimum value of the area, plus half of the tooth tip area of the wrap portion that forms the boundary between the discharge chamber and the compression chamber surrounding it,
In the back pressure region, it is assumed that the differential pressure from the suction pressure decreases as the suction pressure increases.
The swivel end plate is divided into a wrap end plate and a back end plate on which a wrap is erected, and the wrap end plate is integrated with the back discharge pressure region closer to the center,
The rear end plate has an axial end plate gap between the rear end plate and the lap end plate, and is fixed at the outer side, and includes a sealing means that axially moves the inner side but separates the end plate gap and the rear end of the end plate. Separating the interior space
End plate internal pressure, which is the pressure in the end plate space, is an intermediate pressure lower than the back pressure and higher than the suction pressure,
Scroll compressor characterized by. In claim 1,
The end plate internal pressure is introduced through an end plate space communication passage that passes through the wrap end plate and communicates the compression chamber and the end plate space. In claim 2,
In the end plate space communication passage, the end plate opening, which is the compression chamber side opening, communicates only with the compression chamber, and does not communicate with the back pressure region or the suction system. In claim 3,
A scroll compressor characterized in that the end plate mouth is provided so that all inner circles of the end plate ring that is a trajectory drawn by the swivel movement of the end plate port are on the base plate. In any one of Claims 1 thru | or 4,
A scroll compressor characterized in that a rear outermost peripheral portion of the swivel end plate is integrated with the wrap end plate, and the rear end plate is press-fitted or shrinked into an inner periphery of the rear outermost periphery portion. In the scroll compressor in which the orbiting scroll member is urged by the pressure of the back pressure chamber to the fixed scroll member, and the orbiting scroll member and the fixed scroll member mesh to form a compression chamber and compress the working fluid.
In the orbiting scroll member,
A space in the end plate is provided inside,
Scroll compression characterized in that a communication passage that connects the compression chamber and the end plate space is disposed so that a pressure higher than the suction pressure and lower than the back pressure chamber is applied to the end plate space. Machine.

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