JP2009281209A - Scroll compressor - Google Patents

Abstract

A friction loss caused by deformation of a fixed scroll and a turning scroll is reduced to improve the efficiency of a compressor.
A fixed scroll 5 having a spiral wrap standing on the inner peripheral portion of the base plate and a cylindrical end plate 5b surrounding the wrap on the outer peripheral portion; An orbiting scroll 6 in which a spiral wrap that forms a plurality of compression chambers is engaged with the end plate 6b facing the side, and a back pressure chamber provided on the back of the orbiting scroll; A scroll compressor is configured by housing a discharge pressure chamber provided on the back surface of the fixed scroll in a sealed container. An inclined surface 6g is formed on the surface of the orbiting scroll 6 facing the end plate 5b of the fixed scroll 5 in anticipation of the deformation of the scroll in advance from the outer peripheral side to the inner peripheral side.
[Selection] Figure 6

Description

  The present invention relates to a scroll compressor, and in particular, a back pressure chamber serving as an intermediate pressure between discharge pressure and suction pressure is provided on the anti-fixed scroll side of the orbiting scroll, and the intermediate pressure that presses the orbiting scroll against the fixed scroll by this back pressure. The present invention relates to a pressing scroll compressor.

  The scroll compressor includes a fixed scroll in which a spiral wrap is erected on the inner peripheral portion of a disc-shaped base plate and a cylindrical end plate is provided on the outer peripheral portion so as to surround the wrap, and the inner portion of the disc-shaped end plate The orbiting scroll formed by erecting a spiral wrap around the periphery is opposed so that the wraps are engaged with each other, and the working fluid is compressed in a compression chamber formed by the wraps. At this time, due to the compressing action of the working fluid in the compression chamber, a force is generated to separate the scrolls from each other. However, the discharge pressure and the anti-fixed scroll side of the orbiting scroll are prevented from being separated from the fixed scroll. A back pressure chamber serving as an intermediate pressure between the suction pressures is provided, and the orbiting scroll is pressed against the fixed scroll by the back pressure.

  In such an intermediate pressure pressing scroll compressor, for example, as described in Patent Document 1, the fixed scroll and the orbiting scroll are elastically deformed by the pressing force due to the ambient pressure and back pressure during the operation of the refrigeration cycle. It is known. In other words, if the fixed scroll is arranged on the upper side and the orbiting scroll is arranged on the lower side, the fixed scroll is pressed downward from the top by the discharge pressure on the counter-orbiting scroll side, and the central part is generally downward (the orbiting scroll). Deforms to be convex to the side). On the other hand, the orbiting scroll is pressed against the fixed scroll that is deformed downward by the back pressure on the anti-fixed scroll side. In order to follow the deformation, the entire central portion is deformed so as to protrude downward.

  Thus, if the tooth tip surface and the tooth bottom surface of the laps of both scrolls come into strong contact, friction loss occurs at this portion, and the efficiency of the compressor decreases. In this regard, in Patent Document 1, by providing a step with a minute gap between the bottom surfaces of the orbiting scroll and the fixed scroll, the friction loss is reduced so that the contact between the wrap tooth tip and the bottom surface does not become strong. .

JP-A-1-159482

  However, with only the technique described in Patent Document 1, it may be difficult to suppress the generation of friction loss and improve the efficiency of the compressor.

  That is, for example, in recent years, carbon dioxide having a very low global warming factor has been used as a refrigerant instead of a fluorocarbon refrigerant from the viewpoint of preventing global warming. Carbon dioxide refrigerant has a characteristic that its operating pressure is about 3 to 5 times higher than that of Freon refrigerant, so that the discharge pressure that presses the fixed scroll and the back pressure that presses the orbiting scroll become larger than the conventional one.

  In this case, the fixed scroll is deformed so that the central portion is generally convex downward as in the conventional case, whereas the orbiting scroll is generally convex upward (fixed scroll side) unlike the conventional scroll. It transforms to become.

  This is because the orbiting scroll is pressed against the fixed scroll with a larger back pressure than the conventional one, and the lap tooth tip surface and the tooth bottom surface come into strong contact with each other, and the wear of the lap tooth tip surface is larger than the conventional speed. This is to make progress. As the wear on the wrap tooth tip progresses, the orbiting scroll gradually deforms so that the center part becomes convex upward (fixed scroll side) as a whole, and with this change the cylindrical end plate that surrounds the fixed scroll wrap And the end plate of the orbiting scroll are stronger on the inner peripheral side than on the outer peripheral side. In this way, wear is generated so as to absorb the deformation of the orbiting scroll on the inner peripheral side of the contact surface between the fixed scroll and the end plate of the orbiting scroll, and the friction loss increases, so it is difficult to improve the efficiency of the compressor. I have to.

  Therefore, an object of the present invention is to reduce the friction loss caused by the deformation of the fixed scroll and the orbiting scroll and improve the efficiency of the compressor.

  The scroll compressor of the present invention includes a fixed scroll in which a spiral wrap is erected on the inner peripheral portion of the base plate and a cylindrical end plate is provided on the outer peripheral portion so as to surround the wrap, and the fixed scroll Provided on the back of the orbiting scroll on the side of the anti-fixed scroll, and the orbiting scroll that has a spiral wrap standing on the end plate facing the lap standing side and is engaged with the fixed scroll lap to form a plurality of compression chambers. A back pressure chamber that is maintained at a pressure between the discharge pressure and suction pressure of the working fluid, a discharge pressure chamber that is provided on the back surface of the fixed scroll on the side opposite to the orbiting scroll and is maintained at the discharge pressure of the working fluid, and the fixed scroll And an orbiting scroll, a back pressure chamber, and a sealed container that houses the discharge pressure chamber.

  And in order to solve the said subject, at least one of the mutually opposing surface of the end plate of a fixed scroll and the end plate of a turning scroll is formed so that plate | board thickness of an inner peripheral side may become smaller than an outer peripheral side, It is characterized by the above-mentioned. .

  That is, by forming the opposite surfaces of the end plates of both scrolls in advance corresponding to the deformation of the scroll, the end plates of both scrolls can be brought into surface contact evenly on the inner and outer peripheral sides. Therefore, it is possible to reduce the frictional loss by relieving the one-side contact at the contact portion of the end plates of both scrolls, improve the conformability and improve the efficiency of the compressor.

  More specifically, at least one of the facing surfaces of the end plate of the orbiting scroll and the end plate of the fixed scroll can be formed with an inclined surface whose thickness decreases from the outer peripheral side to the inner peripheral side. Moreover, you may form the staircase surface in which plate | board thickness becomes small in steps from the outer peripheral side to the inner peripheral side.

  By the way, as described above, when the orbiting scroll is deformed in a direction different from the conventional one (when the entire center portion is deformed so as to protrude toward the fixed scroll), the contact between the fixed scroll and the end plate of the orbiting scroll is stopped. In addition to the friction loss due to the above, there may be a factor that makes it difficult to improve the compressor efficiency by generating the friction loss.

  That is, a scroll compressor configured by housing a frame that supports the outer peripheral surface of the end plate of the orbiting scroll on the anti-fixed scroll side in a hermetically sealed container generally has the orbiting scroll supported by the frame when stopped and is in operation. Is pressed against the fixed scroll by increasing the back pressure and does not contact the frame. However, even during operation, if the orbiting scroll is deformed as described above, the supported surface may come into contact with the frame and cause friction loss.

  Therefore, the scroll compressor according to the present invention is characterized in that at least a part of the supported surface of the orbiting scroll supported by the frame is formed so that the plate thickness on the outer peripheral side is smaller than the inner peripheral side.

  As a result, even if the orbiting scroll is deformed during operation, since the shape to avoid contact with the frame is applied to the supported surface, the generation of friction loss can be suppressed and the efficiency of the compressor can be improved.

  More specifically, at least a part of the supported surface of the orbiting scroll supported by the frame may be formed with an inclined surface whose thickness decreases from the inner peripheral side to the outer peripheral side, or from the inner peripheral side. You may form the staircase surface which plate | board thickness becomes small in steps toward the outer peripheral side.

  Further, a stepped surface having a smaller plate thickness than the inner peripheral side may be formed on at least a part of the supported surface of the orbiting scroll supported by the frame.

  In particular, the present invention is preferably applied to a scroll compressor using carbon dioxide as a working fluid, but is not limited thereto. The point is that the orbiting scroll is deformed in the same manner as described above due to the relative relationship between the values of the suction pressure, back pressure, and discharge pressure of the working fluid and the rigidity of the fixed scroll and the orbiting scroll, so that the contact between the end plates of both scrolls The present invention can be applied to the case where the friction loss due to or the friction loss due to the contact between the orbiting scroll and the frame occurs.

  ADVANTAGE OF THE INVENTION According to this invention, the friction loss resulting from a deformation | transformation of a fixed scroll and a turning scroll can be reduced, and the efficiency of a compressor can be improved.

  Hereinafter, embodiments of a scroll compressor to which the present invention is applied will be described with reference to each example. In the following description, the same functional parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a view showing a longitudinal section of the scroll compressor of this embodiment. FIG. 2 is a view showing a longitudinal section of the basic configuration of the fixed scroll and the orbiting scroll of the scroll compressor of this embodiment. In FIG. 2, the relative dimensional ratios of the fixed scroll and the orbiting scroll do not exactly match.

  The scroll compressor 1 includes a compression mechanism unit 3 including a turning scroll 6 and a fixed scroll 5, an electric motor 4 that drives the compression mechanism unit 3, and a sealed container 2 that houses the compression mechanism unit 3 and the electric motor 4. Composed. A compression mechanism unit 3 is disposed in the upper part of the sealed container 2, and an electric motor 4 is disposed in the lower part. A lubricating oil 13 is stored at the bottom of the sealed container 2.

  The sealed container 2 is configured by welding a lid chamber 2b and a bottom chamber 2c up and down to a cylindrical case 2a. The lid chamber 2b is provided with a suction pipe 2d, and a discharge pipe 2e is provided on the side surface of the case 2a. The inside of the sealed container 2 is a discharge pressure chamber 2f. That is, the discharge pressure chamber 2 f is accommodated in the sealed container 2. Further, the compression mechanism 3 and the electric motor 4 are accommodated in the discharge pressure chamber 2f.

The fixed scroll 5 is provided in a cylindrical shape so as to surround the wrap 5a on a disk-shaped base plate 5d, a spiral wrap 5a standing on the inner peripheral portion of the base plate 5d, and an outer peripheral portion of the base plate 5d. It is configured to have an end plate 5b and the like. The periphery of the base plate 5d is fixed to the inner wall surface of the sealed container 2 by welding or the like.
The orbiting scroll has a disc-shaped end plate 6b facing the standing side of the wrap 5a of the fixed scroll 5, a spiral wrap 6a standing on the inner peripheral portion of the end plate 6b and meshing with the fixed scroll wrap 6a. Configured. The orbiting scroll 6 is disposed to be opposed to the fixed scroll 5 so as to be orbitable. A suction chamber 10 and a compression chamber 11 are formed between the fixed scroll wrap 6a and the orbiting scroll wrap 5a. The scroll wrap is formed with a circular involute curve or the like as a basic curve. The scroll wrap is formed by engaging both scrolls with each other and a compression chamber formed outside the winding end wrap of the orbiting scroll and a compression chamber formed inside the compression chamber. The asymmetric scroll shape is different in size and formed with a phase shift of about 180 ° with respect to the rotation of the shaft.

  The compression mechanism unit 3 includes a fixed scroll 5, a turning scroll 6, and a frame 9 that is integrated with the fixed scroll 5 with a bolt 8 to support the turning scroll 6.

  The outer peripheral side of the frame 9 is fixed to the inner wall surface of the sealed container 2 by welding or the like. The fixed scroll 5 is provided with a release valve device 15. The frame 9 is provided with a main bearing 9a that rotatably supports the crankshaft 7. An eccentric portion 7 b of the crankshaft 7 is connected to the lower surface side of the orbiting scroll 6.

  An Oldham ring 12 is disposed between the lower surface side of the orbiting scroll 6 and the frame 9. The Oldham ring 12 is mounted in a groove formed on the lower surface side of the orbiting scroll 6 and a groove formed on the frame 9. Yes. The Oldham ring 12 functions to revolve by receiving the eccentric rotation of the eccentric portion 7 b of the crankshaft 7 without rotating the orbiting scroll 6.

  The electric motor 4 includes a stator 4a and a rotor 4b. The stator 4a is fastened to the sealed container 2 by press-fitting or welding. The rotor 4b is rotatably arranged in the stator 4a. A crankshaft 7 is fixed to the rotor 4b, and the orbiting scroll 6 is caused to orbit as the rotor 4b rotates.

  The crankshaft 7 includes a main shaft 7 a and an eccentric portion 7 b and is supported by a main bearing 9 a and a lower bearing 17 provided on the frame 9. The eccentric portion 7 b is formed integrally with the main shaft 7 a of the crankshaft 7 so as to be eccentric, and is fitted to a orbiting bearing provided on the back surface of the orbiting scroll 6. The crankshaft 7 is driven by the electric motor 4, and the eccentric portion 7b is eccentrically rotated with respect to the main shaft 7a to drive the orbiting scroll 6. Further, the crankshaft 7 is provided with an oil supply passage 7c that guides the lubricating oil 13 to the main bearing 9a, the lower bearing 17 and the slewing bearing, and an oil supply pipe 7d that sucks the lubricating oil 13 into the motor-side shaft end and guides it to the oil supply passage 7c. It is installed.

  Between the back side of the orbiting scroll 6 and the frame 9, a back pressure chamber 14 is formed which is an intermediate pressure between the pressure of the suction pipe 2 d and the pressure of the discharge pressure chamber 2 f. Lubricating oil 13 sealed at the bottom of the hermetic container 2 is supplied to the main bearing 9a and the like through an oil supply passage 7c formed at the center of the crankshaft 7 due to a pressure difference between the back pressure chamber 14 and the discharge pressure chamber 2f. The back pressure chamber 14 is formed in a path for supplying the lubricating oil 13 in the sealed container 2 to the sliding portion of the compression mechanism portion 3.

  When the orbiting scroll 6 is orbitally moved through the crankshaft 7 driven by the electric motor 4, the laps of both scrolls mesh with each other, and two compression chambers having different sizes are alternately formed with a phase difference of 180 degrees. The Then, the working fluid such as refrigerant gas is guided from the suction pipe 2d to the compression chamber 11 formed by the orbiting scroll 6 and the fixed scroll 5, where the volume of the refrigerant gas is reduced as it moves in the center direction of the scroll. Compressed. The compressed refrigerant gas is discharged from the discharge port 5e provided at the approximate center of the base plate 5d of the fixed scroll 5 to the discharge pressure chamber 2f in the sealed container 2, and flows out from the discharge pipe 2e to the outside.

  Next, the back pressure control valve 16 that is a pressure adjusting mechanism of the back pressure chamber 14 will be described. The back pressure is an intermediate pressure between the discharge pressure and the suction pressure held in the space surrounded by the back of the orbiting scroll and the frame 9 in order to bring the orbiting scroll into close contact with the fixed scroll and prevent leakage in the compression chamber (this pressure). Pressure is called back pressure). A mechanism for creating the back pressure and controlling the value is the back pressure control valve 16. The back pressure control valve 16 controls the pressure in the back pressure chamber 14 and presses the orbiting scroll 6 against the fixed scroll 5.

  The operation of the back pressure control valve 16 will be described. Lubricating oil 13 stored in the lower part of the sealed container 2 is supplied to each bearing portion through the oil supply pipe 7d and the oil supply passage 7c due to a pressure difference between the sealed container 2 and the back pressure chamber 14. The lubricating oil 13 supplied to the bearing portion enters the back pressure chamber 14, and the refrigerant dissolved in the lubricating oil 13 foams to increase the pressure in the back pressure chamber 14. Here, since the spring pressing the back pressure control valve 16 communicates with the suction chamber 10, the valve body opens when the pressure difference between the back pressure chamber 14 and the suction chamber 10 exceeds the pressing force of the spring, and the back pressure is increased. The lubricating oil 13 in the chamber 14 is supplied to the suction chamber 10. That is, the pressure in the back pressure chamber 14 is controlled as the suction pressure + a constant value (this constant value is determined by the spring force).

  Next, pressure deformation of the compression mechanism unit 3 during operation of the scroll compressor will be described. First, FIG. 3 is a diagram schematically showing pressure deformation of the compression mechanism portion 3 of the conventional scroll compressor. As shown in the drawing, since the upper part of the fixed scroll 5 (counter-turning scroll side) faces the discharge pressure chamber 2f, the discharge pressure acts on the upper surface of the fixed scroll 5. Further, since the lower part of the orbiting scroll 6 (the anti-fixed scroll side) faces the back pressure chamber 14, the back pressure acts on the lower surface of the orbiting scroll and presses the orbiting scroll 6 upward.

  In the case of the conventional scroll compressor, since the peripheral edge of the end plate 5b is fixed to the sealed container 2, the fixed scroll 5 is deformed so that the central portion is convex downward (orbiting scroll side) as a whole. On the other hand, since the orbiting scroll 6 is pressed against the fixed scroll deformed in the downward convex, the lap tooth tip surface and the tooth bottom surface of the center part of both scrolls are in contact with each other and further pressed to follow the deformation of the fixed scroll. As a whole, the central portion is deformed so as to protrude downward.

  In this case, since the orbiting scroll 6 is deformed to follow the deformation of the fixed scroll 5, the end plates of both scrolls are approximately in surface contact with each other, and the conformability is good, so that the problem of friction loss hardly occurs. On the other hand, depending on the relative relationship between the values of the suction pressure, the back pressure, and the discharge pressure of the working fluid and the rigidity of the fixed scroll 5 and the orbiting scroll 6, the orbiting scroll is deformed differently from the conventional scroll scrolls. The problem of friction loss may occur due to the contact between the two end plates.

  For example, in recent years, carbon dioxide, which has a very low global warming coefficient, has been used as a refrigerant instead of CFC refrigerant from the viewpoint of preventing global warming. 3-5 times higher. In a compressor using carbon dioxide as a working fluid, the discharge pressure is about 7 to 13 MPa, the suction pressure is 2 to 5 MPa, the back pressure is 4 to 6 MPa, and a large pressure difference acts. The pressing force of the scroll becomes larger than the conventional one.

  In this case, the fixed scroll 5 and the orbiting scroll 6 are deformed as shown in FIG. FIG. 4 is a diagram schematically illustrating pressure deformation of the compression mechanism unit 3 of the scroll compressor according to the present embodiment. That is, the deformation of the fixed scroll 5 is substantially the same as that of the conventional scroll compressor, and the center portion is deformed so as to be maximum displaced downward and to be convex downward as a whole. In the case of the same shape as in the prior art, the pressure acting on the surroundings becomes larger in the carbon dioxide refrigerant, so that the maximum displacement at the center portion of the scroll wrap becomes larger than in the conventional case. However, it is possible to make the displacement similar to the conventional one by giving rigidity according to the value of the working pressure.

  On the other hand, since the orbiting scroll 6 receives a pressing force due to back pressure from below to above, the center portion of the wrap tooth of the wrap 5a of the fixed scroll 5, the center portion 6f of the bottom of the orbiting scroll 6, and the center of the bottom of the fixed scroll. The center portion of the tooth tip of the orbiting scroll wrap 6a comes into contact with the portion 5f. In order to prevent this contact from becoming excessively strong, the tooth bottoms of the orbiting scroll 6 and the fixed scroll 5 are each provided with a step which becomes deeper from the outside toward the center, and absorbs the displacement of each member due to pressure deformation. ing.

  However, in a scroll compressor using carbon dioxide as a working fluid, the pressure difference is large and the pressing force of the orbiting scroll against the fixed scroll 5 is large, so that wear of the lap tooth tip surfaces of both scrolls proceeds at a relatively high speed. As the wear of the lap tooth tip surface progresses, the orbiting scroll 6 is deformed so that the central portion is convex upward (fixed scroll side) as a whole unlike the prior art. With this change, the contact between the cylindrical end plate 5b surrounding the wrap of the fixed scroll 5 and the end plate 6b of the orbiting scroll 6 hits more strongly on the inner peripheral side than on the outer peripheral side.

  In this way, wear occurs so as to absorb the deformation of the orbiting scroll 6 on the inner peripheral side of the contact surface of the end plate of the fixed scroll 5 and the orbiting scroll 6, and the friction loss increases, thereby improving the efficiency of the compressor. Making it difficult.

  The characteristic part of the scroll compressor of the present embodiment for preventing the increase in the compressor input and the loss due to the friction of the end plate surface will be described with reference to FIGS. 5 is a top view of the orbiting scroll of the scroll compressor of the first embodiment, and FIG. 6 is a cross-sectional view of the orbiting scroll of FIG.

  As shown in FIGS. 5 and 6, the wrap forming surface of the end plate 6b of the orbiting scroll 6 of the scroll compressor of the present embodiment (the opposite surface of the end plate of the orbiting scroll and the end plate of the fixed scroll) is directed inward from the outer peripheral side. The inclined surface 6g is formed so as to become deeper (the thickness decreases from the outer peripheral side to the inner peripheral side).

  In other words, the surface of the end plate of the orbiting scroll 6 that faces the end plate of the fixed scroll 5 is formed by the inclined surface 6g that inclines so as to increase from the 6e surface having the radius of the outermost peripheral portion at the end of the wrap winding toward the outer periphery of the end plate. Has been. The inclination angle θ1 is set to be in the range of tan θ1 = 1/10000 to 1/500.

  The scroll compressor is operated and the compression mechanism unit 3 is operated by previously forming the face of the end plate 6b of the orbiting scroll 6 facing the end plate 5b of the fixed scroll 5 so that the plate thickness on the inner periphery side is smaller than the outer periphery side. When the working fluid pressure is applied, the fixed scroll end plate 5b and the inclined surface 6g of the orbiting scroll end plate are prevented from being strongly contacted (one-sided) at the lap root portion (the inner peripheral side of the opposite contact surface of the end plates of both scrolls). Make surface contact evenly.

  Therefore, since the pressing force of the orbiting scroll can be borne with an appropriate surface pressure, an increase in input and an increase in loss due to friction can be prevented.

  Next, a second embodiment of the scroll compressor of the present invention will be described. This embodiment is different from the first embodiment only in the shape of the surface formed on the surface of the end plate 6b of the orbiting scroll 6 facing the end plate 5b of the fixed scroll 5. Therefore, description of other parts similar to those of the first embodiment is omitted.

  7 is a top view of the orbiting scroll of the scroll compressor of the second embodiment, and FIG. 8 is a cross-sectional view of the orbiting scroll of FIG. In the present embodiment, the surface of the orbiting scroll 6 facing the end plate 5b of the fixed scroll 5 of the end plate 6b is a step surface composed of 6c, 6d, and 6e surfaces whose thickness decreases stepwise from the outer peripheral side to the inner peripheral side. Is formed.

  In other words, the 6d surface on the outer peripheral side is higher than the 6e surface near the end of the wrap winding, for example, in the range of about 1 to 10 μm (dimension α), and the 6c surface on the outer peripheral side is the 6d surface. On the other hand, for example, by forming it higher in the range of about 1 to 10 μm (dimension β), a staircase surface that increases stepwise as it goes from the vicinity of the end of the wrap winding toward the outer periphery is formed.

  By forming the face of the end plate 6b of the orbiting scroll 6 facing the end plate 5b of the fixed scroll 5 in this way, the orbiting scroll 6 is operated when the scroll compressor is operated and the working fluid pressure is applied to the compression mechanism section 3. Is deformed so that the central portion is convex upward, and the contact surface of the fixed scroll of the end plate 6b with the end plate 5b has a shape substantially along the end plate 5b. At this time, the surfaces 6c, 6d, and 6e of the end plate of the orbiting scroll and the end plate 5b of the fixed scroll come into contact with each other at the corner of the step, so that the familiarity is easy to progress, and the shape along the fixed scroll end plate is formed in a short time. Can be formed.

  In addition, this step makes it possible to retain oil on the inner peripheral side of the end plate surface, so it has the effect of supplying oil to the corner of the step that is familiar, preventing adhesion at the corner, This has the effect of reducing the friction loss and improving the sliding reliability.

  As described above, in the present embodiment, an effect of facilitating the progress of the familiarity of the end plate 6b of the orbiting scroll 6 with the contact surface of the fixed scroll with the end plate 5b appears. Therefore, it is possible to form a surface according to the deformation state of the fixed scroll that changes depending on various operating conditions. For this reason, it is possible to prevent an increase in input and an increase in loss due to friction of the end plate under various conditions as well as specific operating conditions. Further, by setting the circumferential step, there is an effect that high-precision processing is easy when the end plate surface is processed by an end mill.

  In this example, the circumferential step is formed as two steps. However, the larger the number of steps, the smaller the steps per step and the less the contact at the corners of the steps, thus further reducing the friction loss. can do. In addition, since the refrigerant leakage at the end plate portion can be reduced, leakage loss can be reduced, and a more efficient scroll compressor can be obtained.

  Next, a third embodiment of the scroll compressor of the present invention will be described. The present embodiment is different from the first and second embodiments in that the end plate of the orbiting scroll is not processed in advance for the deformation of the scroll, but the end plate 5b of the fixed scroll 5 is processed. Therefore, description of other parts similar to those of the first embodiment is omitted.

  9 is a bottom view of the fixed scroll of the scroll compressor of the third embodiment, and FIG. 10 is a cross-sectional view of the fixed scroll of FIG. In the present embodiment, an inclined surface 5g that decreases in thickness from the outer peripheral side to the inner peripheral side is formed on the surface of the end plate 5b of the fixed scroll 5 facing the end plate 6b of the orbiting scroll 6.

  In other words, the inclined surface 5g is formed on the surface of the end plate 5b of the fixed scroll 5 facing the end plate 6b of the orbiting scroll 6 so as to protrude downward toward the outer peripheral side of the end plate with respect to the wrap 5a. In this configuration, an inclined surface similar to the inclined surface 6g formed on the end plate of the orbiting scroll in the first embodiment is formed on the end plate of the fixed scroll.

  According to this, similarly to the first embodiment, when the scroll compressor is operated and the working fluid pressure is applied to the compression mechanism section 3, the inclined surface 5g formed on the end plate 5b of the fixed scroll and the end plate of the orbiting scroll. 6b prevents the strong contact (one piece contact) in the lap | root base part (opposite contact surface inner peripheral side of the end plate of both scrolls), and carries out surface contact equally.

  Therefore, since the pressing force of the orbiting scroll can be borne with an appropriate surface pressure, an increase in input and an increase in loss due to friction can be prevented.

  In the first and second embodiments, the orbiting scroll end plate is preliminarily processed to allow for deformation of the scroll, and in the third embodiment, the fixed scroll end plate is previously processed to allow for deformation of the scroll. . However, the present invention is not limited thereto, and processing that allows for deformation of the scroll may be appropriately performed on the opposing surfaces of the end plates of both the fixed scroll and the orbiting scroll. Similarly, the friction loss caused by the deformation of the scroll can be reduced and the efficiency of the compressor can be improved.

  Next, a fourth embodiment of the present invention will be described in detail below. In the present embodiment, unlike the first to third embodiments, the opposite surfaces of the end plates of the fixed scroll and the orbiting scroll are not preliminarily processed in anticipation of the deformation of the scroll, but the end plate of the orbiting scroll and the frame are brought into contact with each other. The only difference is that the revolving process is performed on the end plate of the orbiting scroll. Therefore, description of other parts similar to those of the first embodiment is omitted.

  Although the orbiting scroll 6 is supported by the frame 9 on the outer peripheral side of the rear surface of the end plate 6b, the orbiting scroll 6 is pressed against the fixed scroll 5 and does not come into contact with the frame 9 due to an increase in back pressure during operation. The gap between the frame 9 and the orbiting scroll 6 needs to be set appropriately. If it is small, contact occurs due to deformation or swinging motion of the orbiting scroll during operation, which causes a reduction in efficiency. On the other hand, if the gap is large, the orbiting scroll does not rise because the back pressure cannot be sealed, and the normal scrolling operation cannot be performed without being pressed against the fixed scroll.

  Therefore, this gap is usually set to about 10 to 30 μm, for example. However, in the scroll compressor using carbon dioxide as the refrigerant, as described above, the orbiting scroll 6 is deformed so that the central portion thereof is convex upward (fixed scroll side) as a whole unlike the conventional one. In addition, the outer peripheral side of the back surface (supported surface) of the end plate easily comes into contact with the frame. When the supported surface of the end plate of the orbiting scroll 6 and the frame 9 are in contact with each other, a friction loss occurs, making it difficult to improve the efficiency of the compressor.

  A characteristic part of this embodiment for preventing an increase in compressor input and an increase in loss due to the friction of the end plate surface will be described. 11 is a top view of the orbiting scroll of the scroll compressor of the fourth embodiment, FIG. 12 is a sectional view of the orbiting scroll of FIG. 11, and FIG. 13 is a sectional view of the orbiting scroll and the frame.

  In this embodiment, a part of the supported surface supported by the frame 9 of the orbiting scroll 6 has a stepped surface having a smaller plate thickness than the inner peripheral side so that the outer peripheral side plate thickness is smaller than the inner peripheral side. Is formed. In other words, a 6h surface that forms a step in a circumferential shape is provided on the back side of the end plate 6b of the orbiting scroll 6 so that the outer periphery is lowered in the range of about 10 to 500 μm (dimension γ) with respect to the inner periphery. .

  In addition, a step is not formed by the 6h surface, but an inclined surface in which the plate thickness decreases from the inner peripheral side to the outer peripheral side of the supported surface of the end plate of the orbiting scroll, or the plate thickness from the inner peripheral side to the outer peripheral side. Alternatively, a staircase surface that becomes smaller in a staircase pattern may be formed.

  By giving such a shape to the end plate 6b of the orbiting scroll 6 in advance, when the scroll compressor is operated and the orbiting scroll 6 is deformed so that the central portion is convex upward, the end surface of the end plate is the frame 9 It can suppress contacting the surface opposite to the back surface of the end plate. Therefore, generation | occurrence | production of friction loss can be suppressed and the efficiency of a compressor can be improved.

  In this embodiment, the 6h surface forming the step is not provided over the entire circumference of the relative surface on the frame side so that the orbiting scroll 6 normally floats. It is necessary to secure a seal surface between the scroll mirror plate back surface and the frame relative surface. Therefore, the width of the step 6h is approximately the turning radius of the crankshaft 7.

  As mentioned above, although each Example of the scroll compressor of this invention was described, it is not restricted to the form of these each Example, Each Example can also be combined suitably. For example, the first to third embodiments and the fourth embodiment can be combined. In other words, the end face of the fixed scroll and the end face of the orbiting scroll have a shape that allows for the deformation of the scroll, and the supported face of the end face of the orbiting scroll has a shape that allows for the deformation of the scroll. You may give it.

  In each of the above-described embodiments, the scroll compressor using carbon dioxide as the working fluid has been described as an example, but the present invention is not limited thereto. When carbon dioxide is used as the working fluid, deformation unlike the conventional one of the orbiting scroll (deformation in which the central part protrudes toward the fixed scroll) is likely to occur, but the same is true for working fluids other than carbon dioxide Deformation of can occur.

  The point is that the center part of the orbiting scroll is deformed so that it protrudes to the fixed scroll side due to the relative relationship between the values of the suction pressure, back pressure and discharge pressure of the working fluid and the rigidity of the fixed scroll and orbiting scroll. The present invention can be applied to the case where friction loss due to contact between the end plates of both scrolls occurs or friction loss due to contact between the orbiting scroll and the frame occurs.

It is a figure which shows the longitudinal cross-section of the scroll compressor of 1st Example. It is a longitudinal cross-sectional view which shows the basic composition of a fixed scroll and a turning scroll. It is the figure which showed typically the pressure deformation of the compression mechanism part of the conventional scroll compressor. It is the figure which showed typically the pressure deformation of the compression mechanism part of the scroll compressor of 1st Example. It is a top view of the turning scroll of the scroll compressor of the 1st example. It is sectional drawing of the turning scroll of FIG. It is a top view of the turning scroll of the scroll compressor of 2nd Example. It is sectional drawing of the turning scroll of FIG. It is a bottom view of the fixed scroll of the scroll compressor of 3rd Example. It is sectional drawing of the fixed scroll of FIG. It is a top view of the turning scroll of the scroll compressor of 4th Example. It is sectional drawing of the turning scroll of FIG. It is sectional drawing of a turning scroll and a flame | frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Airtight container 2f Discharge pressure chamber 5 Fixed scroll 5a Wrap 5b End plate 5d Base plate 5g Inclined surface 6 Orbiting scroll 6a End plate 6g Inclined surface 9 Frame 10 Suction chamber 11 Compression chamber 14 Back pressure chamber

Claims (9)

A fixed scroll in which a spiral wrap is erected on the inner peripheral portion of the base plate and a cylindrical end plate is provided on the outer peripheral portion so as to surround the wrap, and facing the wrap erection side of the fixed scroll A swirl scroll in which a spiral wrap that is engaged with the fixed scroll wrap to form a plurality of compression chambers is erected on the end plate, and a discharge of working fluid provided on the back surface of the orbiting scroll on the side opposite to the fixed scroll A back pressure chamber that is maintained at a pressure between the pressure and the suction pressure, a discharge pressure chamber that is provided on the back surface of the fixed scroll on the side opposite to the orbiting scroll and is maintained at the discharge pressure of the working fluid, the fixed scroll, A scroll compressor comprising a orbiting scroll, the back pressure chamber, and a sealed container that houses the discharge pressure chamber,
At least one of the opposing surfaces of the end plate of the fixed scroll and the end plate of the orbiting scroll is formed such that the plate thickness on the inner peripheral side is smaller than the outer peripheral side.   2. The scroll compressor according to claim 1, wherein an inclined surface whose thickness decreases from an outer peripheral side to an inner peripheral side is formed on at least one of the opposing surfaces of the end plate of the orbiting scroll and the end plate of the fixed scroll.     2. The scroll compression according to claim 1, wherein at least one of the facing surfaces of the end plate of the orbiting scroll and the end plate of the fixed scroll is formed with a stepped surface whose thickness decreases stepwise from the outer peripheral side to the inner peripheral side. Machine. A fixed scroll in which a spiral wrap is erected on the inner peripheral portion of the base plate and a cylindrical end plate is provided on the outer peripheral portion so as to surround the wrap, and facing the wrap erection side of the fixed scroll A swirl scroll in which a spiral wrap that is engaged with the fixed scroll wrap to form a plurality of compression chambers is erected on the end plate, and a discharge of compressed fluid provided on the back surface of the orbiting scroll on the side opposite to the fixed scroll A back pressure chamber that is maintained at a pressure between the pressure and the suction pressure, a discharge pressure chamber that is provided on the back surface of the fixed scroll on the side opposite to the orbiting scroll and that is maintained at the discharge pressure of the compressed fluid, and the end plate of the orbiting scroll A frame that supports an outer peripheral surface of the anti-fixed scroll side, a fixed scroll, the orbiting scroll, the back pressure chamber, the discharge pressure chamber, and a sealed container that houses the frame. A Ete become scroll compressor,
A scroll compressor characterized in that at least a part of a supported surface of the orbiting scroll supported by the frame is formed so that a plate thickness on an outer peripheral side is smaller than an inner peripheral side.   5. The scroll compressor according to claim 4, wherein an inclined surface whose thickness decreases from an inner peripheral side to an outer peripheral side is formed on at least a part of a supported surface of the orbiting scroll supported by the frame.   5. The scroll compressor according to claim 4, wherein at least a part of a supported surface of the orbiting scroll supported by the frame is formed with a stepped surface having a stepped thickness that decreases from an inner peripheral side to an outer peripheral side.   The scroll compressor according to claim 4, wherein a stepped surface having a thickness smaller than that of the inner peripheral side is formed on at least a part of the supported surface of the orbiting scroll supported by the frame. A fixed scroll in which a spiral wrap is erected on the inner peripheral portion of the base plate and a cylindrical end plate is provided on the outer peripheral portion so as to surround the wrap, and facing the wrap erection side of the fixed scroll A swirl scroll in which a spiral wrap that is engaged with the fixed scroll wrap to form a plurality of compression chambers is erected on the end plate, and a discharge of compressed fluid provided on the back surface of the orbiting scroll on the side opposite to the fixed scroll A back pressure chamber that is maintained at a pressure between the pressure and the suction pressure, a discharge pressure chamber that is provided on the back surface of the fixed scroll on the side opposite to the orbiting scroll and that is maintained at the discharge pressure of the compressed fluid, and the end plate of the orbiting scroll A frame that supports an outer peripheral surface of the anti-fixed scroll side, a fixed scroll, the orbiting scroll, the back pressure chamber, the discharge pressure chamber, and a sealed container that houses the frame. A Ete become scroll compressor,
At least one of the opposing surfaces of the end plate of the fixed scroll and the end plate of the orbiting scroll is formed so that the plate thickness on the inner peripheral side is smaller than the outer peripheral side,
A scroll compressor characterized in that at least a part of a supported surface of the orbiting scroll supported by the frame is formed so that a plate thickness on an outer peripheral side is smaller than an inner peripheral side.   The scroll compressor according to claim 1, wherein carbon dioxide is used as the working fluid.

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