Patent Publication Number: US-11047384-B2

Title: Scroll compressor with non-uniform gap

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. National stage application claims priority under 35 U.S.C. § 119(a) to Japanese Patent Application No. 2016-133795, filed in Japan on Jul. 6, 2016, the entire contents of which are hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a scroll compressor having a non-uniform gap. 
     BACKGROUND ART 
     A scroll compressor equipped with a fixed wrap and an orbiting wrap that have tooth bottom portions in which steps are formed so as to become deeper heading front an outer peripheral side to an inner peripheral side is known (see International Publication No. WO 2014/155646). 
     SUMMARY 
     The inventors of the present application discovered that in this type of scroll compressor the temperature inside the compression chamber during operation rises more exponentially than rises linearly heading from the outer peripheral side to the inner peripheral side. Consequently, for example, even if steps are formed in the tooth bottom portions so as to become deeper heading from the outer peripheral side to the inner peripheral side as in the scroll compressor of International Publication No. WO 2014/155646, the steps are insufficient, and, as a result, there is the concern that the fixed scroll and the orbiting scroll will contact each other. Particularly in a case where high compression efficiency is required in a low-load condition, the volumes of the fixed wrap and the orbiting wrap are designed smaller. In such a configuration as this, it is easy for the refrigerant to be over-compressed in a high-load condition, that is, it is easier for the temperature to rise, so the aforementioned problem becomes more pronounced. 
     It is a problem of the present invention to provide a scroll compressor that inhibits contact between the fixed scroll and the orbiting scroll. 
     A scroll compressor pertaining to a first aspect of the invention has a fixed scroll and an orbiting scroll. The fixed scroll has a first base and a first wrap. The first wrap is formed spirally on the first base. The orbiting scroll forms a compression chamber together with the fixed scroll. The orbiting scroll has a second base and a second wrap. The second wrap is formed spirally on the second base. The scroll compressor satisfies at least one of a first condition and a second condition. The first condition is a condition where a first gap between a distal end of the first wrap and the second base changes heading from an outer peripheral side of the first wrap to an inner peripheral side and where the rate of change in the first gap from a center of the first wrap to an intermediate point of the first wrap is greater than the rate of change in the first gap from the intermediate point of the first wrap to an outer peripheral end of the first wrap. The second condition is a condition where a second gap between a distal end of the second wrap and the first base changes heading from an outer peripheral side of the second wrap to an inner peripheral side and where the rate of change in the second gap from a center of the second wrap to an intermediate point of the second wrap is greater than the rate of change in the second gap from the intermediate point of the second wrap to an outer peripheral end of the second wrap. 
     In the scroll compressor pertaining to the first aspect of the invention, in a case where the rate of change in the first gap from the center of the first wrap to the intermediate point of the first wrap is greater than the rate of change in the first gap from the intermediate point of the first wrap to the outer peripheral end of the first wrap, the first gap from the center of the first wrap to the intermediate point of the first wrap becomes locally larger. Consequently, contact between the distal end of the first wrap and the second base can be inhibited at the portion of the first wrap from the center of the first wrap to the intermediate point of the first wrap. 
     In the same way, # in a case where the rate of change in the second gap from the center of the second wrap to the intermediate point of the second wrap is greater than the rate of change in the second gap from the intermediate point of the second wrap to the outer peripheral end of the second wrap, the second gap from the center of the second wrap to the intermediate point of the second wrap becomes locally larger. Consequently, contact between the distal end of the second wrap and the first base can be inhibited at the portion of the second wrap from the center of the second wrap to the intermediate point of the second wrap. 
     As described above, by satisfying at least one of the first condition and the second condition, contact between the fixed scroll and the orbiting scroll can be inhibited. 
     In a scroll compressor pertaining to a second aspect of the invention, the portion of the first wrap from the center of the first wrap to the intermediate point of the first wrap is a center portion of the first wrap, and the portion of the second wrap from the center of the second wrap to the intermediate point of the second wrap is a center portion of the second wrap. 
     In the scroll compressor pertaining to the second aspect of the invention, the first gap at the center portion of the first wrap is set to become locally larger in anticipation of expansion of the first wrap due to heat at the center portion of the compression chamber, which can reach a particularly high temperature. Consequently, contact between the fixed scroll and the orbiting scroll at the center portion of the compression chamber can be inhibited. 
     In the same way, the second gap at the center portion of the second wrap is set to become locally larger in anticipation of expansion of the second wrap due to heat at the center portion of the compression chamber, which can reach a particularly high temperature. Consequently, contact between the fixed scroll and the orbiting scroll at the center portion of the compression chamber can be inhibited. 
     In a scroll compressor pertaining to a third aspect of the invention, the first gap changes in a stepwise manner heading from the outer peripheral side of the first wrap to the inner peripheral side. The second gap changes in a stepwise manner heading from the outer peripheral side of the second wrap to the inner peripheral side. 
     In the scroll compressor pertaining to the third aspect of the invention, the first gap and the second gap gradually change heading toward the center portion of the compression chamber, so contact between the fixed scroll and the orbiting scroll can be effectively inhibited. 
     In a scroll compressor pertaining to a fourth aspect of the invention, at least one of the first wrap and the second base is formed in a stepwise manner, whereby the first gap changes in a stepwise manner heading from the outer peripheral side of the first wrap to the inner peripheral side. At least one of the second wrap and the first base is formed in a stepwise manner, whereby the second gap changes in a stepwise manner heading from the outer peripheral side of the second wrap to the inner peripheral side. The at least one of the first wrap and the second base includes at least one step portion in the range of the center portion of the first wrap. The at least one of the second wrap and the first base includes at least one step portion in the range of the center portion of the second wrap. 
     In the scroll compressor pertaining to the fourth aspect of the invention, at least one of the first wrap and the second base is formed in a stepwise manner, so compared to a case where it is formed in a sloping manner, for example, processing for forming the first gap becomes easy. In the same way, at least one of the second wrap and the first base is formed in a stepwise manner, so compared to a case where it is formed in a sloping manner, for example, processing for forming the second gap becomes easy. Furthermore, because of the step portion included in the range of the center portion of the first wrap, the first gap can easily be made locally larger. In the same way, because of the step portion included in the range of the center portion of the second wrap, the second gap can easily be made locally larger. 
     In a scroll compressor pertaining to a fifth aspect of the invention, the center portion of the first wrap is a range from the center of the first wrap to 540°. The center portion of the second wrap is a range from the center of the second wrap to 540°. 
     In the scroll compressor pertaining to the fifth aspect of the invention, the first gap in the range from the center of the first wrap to 540° and the second gap in the range from the center of the second wrap to 540°, which can reach a particularly high temperature, become locally larger. Consequently, contact between the fixed scroll and the orbiting scroll can be effectively inhibited. 
     In a scroll compressor pertaining to a sixth aspect of the invention, the rate of change in the first gap from the center of the first wrap to the intermediate point of the first wrap is in the range of 4.5 times to 5.5 times the rate of change in the first gap from the intermediate point of the first wrap to the outer peripheral end of the first wrap. The rate of change in the second gap from the center of the second wrap to the intermediate point of the second wrap is in the range of 4.5 times to 5.5 times the rate of change in the second gap from the intermediate point of the second wrap to the outer peripheral end of the second wrap. 
     In the scroll compressor pertaining to the sixth aspect of the invention, the rate of change in the first gap from the center of the first wrap to the intermediate point of the first wrap is in the range of 4.5 times to 5.5 times the rate of change in the first gap from the intermediate point of the first wrap to the outer peripheral end of the first wrap, and the rate of change in the second gap from the center of the second wrap to the intermediate point of the second wrap is in the range of 4.5 times to 5.5 times the rate of change in the second gap from the intermediate point of the second wrap to the outer peripheral end of the second wrap, so contact between the fixed scroll and the orbiting scroll can be effectively inhibited. 
     In a scroll compressor pertaining to a seventh aspect of the invention, the fixed scroll and the orbiting scroll compress refrigerant that includes more than 50 wt % R32 as refrigerant. 
     When R410A refrigerant and refrigerant that includes more than 50 wt % R32 are compressed under the same conditions, the refrigerant that includes more than 50 wt % R32 reaches a higher temperature than the R410A refrigerant. That is, it becomes easier for the first wrap and the second wrap to deform. Even in a case such as this, the scroll compressor pertaining to the seventh aspect of the invention satisfies at least one of the first condition and the second condition, so contact between the fixed scroll and the orbiting scroll can be inhibited. 
     In the scroll compressor pertaining to the first aspect of the invention, by satisfying at least one of the first condition and the second condition, contact between the fixed scroll and the orbiting scroll can be inhibited. 
     In the scroll compressor pertaining to the second aspect of the invention, contact between the fixed scroll and the orbiting scroll at the center portion of the compression chamber can be inhibited. 
     In the scroll compressor pertaining to the third aspect of the invention, contact between the fixed scroll and the orbiting scroll can be effectively inhibited. 
     In the scroll compressor pertaining to the fourth aspect of the invention, processing for forming the first gap and the second gap becomes easy. Furthermore, the first gap at the center portion of the first wrap and the second gap at the center portion of the second wrap can easily be made locally larger. 
     In the scroll compressor pertaining to the fifth aspect of the invention, contact between the fixed scroll and the orbiting scroll at the portion that reaches a particularly high temperature can be effectively inhibited. 
     In the scroll compressor pertaining to the sixth aspect of the invention, contact between the fixed scroll and the orbiting scroll can be effectively inhibited. 
     In the scroll compressor pertaining to the seventh aspect of the invention, refrigerant that includes more than 50 wt % R32 is compressed, so even in a case where it becomes easier for the first wrap and the second wrap to deform, contact between the fixed scroll and the orbiting scroll can be inhibited. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a longitudinal sectional view of a scroll compressor pertaining to an embodiment. 
         FIG. 2  is a bottom view of a fixed scroll. 
         FIG. 3  is a top view of an orbiting scroll. 
         FIG. 4A  is a drawing describing a first gap that is a gap between a first wrap and a second end plate. 
         FIG. 4B  is a drawing describing a second gap that is a gap between a first end plate and a second wrap. 
         FIG. 5A  is a drawing describing a change in the height of the first gap. 
         FIG. 5B  is a drawing describing a change in the height of the second gap. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT(S) 
     An embodiment of the invention will be described below. It will be noted that the following embodiment is merely a concrete example and is not intended to limit the invention pertaining to the scope of the claims. 
       FIG. 1  is a longitudinal sectional view of a scroll compressor  101  pertaining to the embodiment. The scroll compressor  101  is used in a refrigerating system such as an air conditioning system. The scroll compressor  101  compresses refrigerant gas that circulates through a refrigerant circuit of the refrigerating system. As the refrigerant, refrigerant that includes more than 50 wt % R32 can be used. 
     (1) Configuration of Scroll Compressor 
     The scroll compressor  101  mainly has a casing  10 , a compression mechanism  15 , a housing  23 , an Oldham coupling  39 , a drive motor  16 , a lower bearing  60 , a crankshaft  17 , a suction pipe  19 , and a discharge pipe  20 . 
     (1-1) Casing 
     The casing  10  is configured from a middle casing portion  11  in the shape of an open cylinder, an upper wall portion  12  in the shape of a bowl, and a bottom wall portion  13  in the shape of a bowl. The upper wall portion  12  is airtightly welded to the upper end portion of the middle casing portion  11 . The bottom wall portion  13  is airtightly welded to the lower end portion of the middle casing portion  11 . The casing  10  is installed in such a way that the axial direction of the open cylinder shape of the middle casing portion  11  lies along the vertical direction. 
     Inside the casing  10  are housed the compression mechanism  15 , the housing  23 , the drive motor  16 , the crankshaft  17 , and the like. In the bottom portion of the casing  10  is formed an oil reservoir  10   a  in which lubricating oil is stored. The lubricating oil is used to well maintain the lubricity of sliding portions of the compression mechanism  15  and the like during the operation of the scroll compressor  101 . 
     (1-2) Compression Mechanism 
     The compression mechanism  15  sucks and compresses low-temperature low-pressure refrigerant gas and discharges compressed refrigerant that is high-temperature high-pressure refrigerant gas. The compression mechanism  15  is configured mainly from a fixed scroll  24  and an orbiting scroll  26 . The fixed scroll  24  is fixed with respect to the casing  10 . The orbiting scroll  26  performs revolving movement with respect to the fixed scroll  24 . 
     (1-2-1) Fixed Scroll 
     The fixed scroll  24  has a first end plate  24   a  serving as a first base and a first wrap  24   b . The first wrap  24   b  is formed upright on the first end plate  24   a . The first wrap  24   b  is spiral in shape. The height of the first wrap  24   b  is preferably 20 to 40 mm. The number of turns of the first wrap  24   b  is longer than the number of turns of a later-described second wrap  26   b . Specifically, it is about ½ turn longer. An outer peripheral surface is not formed on the outermost periphery of the first wrap  24   b . The outermost periphery of the first wrap  24   b  is continuous with the edge portion of the fixed scroll  24 . A main suction hole  24   c  is formed in the first end plate  24   a . The main suction hole  24   c  is a space that interconnects the suction pipe  19  and a later-described compression chamber  40 . The main suction hole  24   c  forms a suction space. The suction space is a space for introducing the low-temperature low-pressure refrigerant gas from the suction pipe  19  to the compression chamber  40 . 
     A discharge hole  41  is formed in the central portion of the first end plate  24   a . An enlarged recess portion  42  that communicates with the discharge hole  41  is formed in the upper surface of the first end plate  24   a . The enlarged recess portion  42  is a space that is recessedly provided in the upper surface of the first end plate  24   a . A cover  44  is fixed by bolts  44   a  to the upper surface of the fixed scroll  24  so as to close off the enlarged recessed portion  42 . The fixed scroll  24  and the cover  44  are tightly sealed via a gasket (not shown in the drawings). A muffler space  45  that muffles the operating sound of the compression mechanism  15  is formed as a result of the enlarged recessed portion  42  being covered with the cover  44 . A first compressed refrigerant flow passage  46  that communicates with the muffler space  45  and opens to the lower surface of the fixed scroll  24  is formed in the fixed scroll  24 . An oil groove  24   e  is formed in the lower surface of the first end plate  24   a.    
     (1-2-2) Orbiting Scroll 
     The orbiting scroll  26  has a second end plate  26   a  serving as a second base and a second wrap  26   b . The second end plate  26   a  is in the shape of a disc. An upper end bearing  26   c  is formed in the central portion of the lower surface of the second end plate  26   a . The second wrap  26   b  is formed upright on the second end plate  26   a . The second wrap  26   b  is spiral in shape. The height of the second wrap  26   b  is preferably 20 to 40 mm. An oil supply pore  63  is formed in the orbiting scroll  26 . The oil supply pore  63  communicates the outer peripheral portion of the upper surface of the second end plate  26   a  to the space inside the upper end bearing  26   c.    
     The first wrap  24   b  and the second wrap  26   b  interfit, whereby the fixed scroll  24  and the orbiting scroll  26  form a compression chamber  40 . The compression chamber  40  is a space enclosed by the first end plate  24   a , the first wrap  24   b , the second end plate  26   a , and the second wrap  26   b . The volume of the compression chamber  40  gradually decreases because of the revolving movement of the orbiting scroll  26 . As the orbiting scroll  26  revolves, the lower surface of the first end plate  24   a  and the first wrap  24   b  of the fixed scroll  24  slides against the upper surface of the second end plate  26   a  and the second wrap  26   b  of the orbiting scroll  26 . In this specification, the surface of the fixed scroll  24  that slides against the orbiting scroll  26  is called a sliding surface  24   d.    
     Although details will be described later, a first gap is formed between the distal end of the first wrap  24   b  (i.e., the portion of the first wrap  24   b  that opposes the second end plate  26   a ) and the second end plate  26   a . A second gap is formed between the distal end of the second wrap  26   b  (i.e., the portion of the second wrap  26   b  that opposes the first end plate  24   a ) and the first end plate  24   a . In the present embodiment, both a first condition and a second condition described below are satisfied in relation to the first gap and the second gap. 
     The first condition is a condition where the first gap changes heading from the outer peripheral side of the first wrap  24   b  to the inner peripheral side and where the rate of change in the first gap in a range from a center  24   p  (see  FIG. 2 ) of the first wrap  24   b  to an intermediate point of the first wrap  24   b  is greater than the rate of change in the first gap in a range from the intermediate point of the first wrap  24   b  to the outer peripheral end of the first wrap  24   b . In the present embodiment, the range from the center  24   p  of the first wrap  24   b  to the intermediate point of the first wrap  24   b  is a range from the center  24   p  of the first wrap  24   b  to 540°. The range from the intermediate point of the first wrap  24   b  to the outer peripheral end of the first wrap  24   b  is a range from 540° of the first wrap  24   b  to 1080°. 
     Although details will be described later, the rate of change in the first gap in the range from the center  24   p  of the first wrap  24   b  to 540° is a value obtained by dividing the amount of change in the height of the first gap in the range from the center  24   p  of the first wrap  24   b  to 540° by the number of steps included in the portion of the second end plate  26   a  corresponding to the range from the center  24   p  of the first wrap  24   b  to 540°. The rate of change in the first gap in the range from 540° of the first wrap  24   b  to 1080° is a value obtained by dividing the amount of change in the height of the first gap in the range from 540° of the first wrap  24   b  to 1080° by the number of steps included in the portion of the second end plate  26   a  corresponding to the range from 540° of the first wrap  24   b  # to 1080°. 
     The second condition is a condition where the second gap changes heading from the outer peripheral side of the second wrap  26   b  to the inner peripheral side and where the rate of change in the second gap in a range from a center  26   p  (see  FIG. 3 ) of the second wrap  26   b  to an intermediate point of the second wrap  26   b  is greater than the rate of change in the second gap in a range from the intermediate point of the second wrap  26   b  to the outer peripheral end of the second wrap  26   b . In the present embodiment, the range from the center  26   p  of the second wrap  26   b  to the intermediate point of the second wrap  26   b  is a range from the center  26   p  of the second wrap  24   b  to 540°. The range from the intermediate point of the second wrap  26   b  to the outer peripheral end of the second wrap  26   b  is a range from 540° to 900° of the second wrap  26   b.    
     Although details will be described later, the rate of change in the second gap in the range from the center  26   p  of the second wrap  26   b  to 540° is a value obtained by dividing the amount of change in the height of the second gap in the range from the center  26   p  of the second wrap  26   b  to 540° by the number of steps included in the portion of the first end plate  24   a  corresponding to the range from the center  26   p  of the second wrap  26   b  to 540°. The rate of change in the second gap in the range from 540° of the second wrap  26   b  to 900° is a value obtained by dividing the amount of change in the height of the second gap in the range from 540° of the second wrap  26   b  to 900° by the number of steps included in the portion of the first end plate  24   a  corresponding to the range from 540° of the second wrap  26   b  # to 900°. 
     (1-3) Housing 
     The housing  23  is disposed under the compression mechanism  15 . The outer peripheral surface of the housing  23  is airtightly joined to the inner peripheral surface of the middle casing portion  11 . Because of this, the inside space of the casing  10  is partitioned into a high-pressure space S 1  under the housing  23  and a low-pressure space S 2  that is a space above the housing  23 . The housing  23  has the fixed scroll  24  mounted on it and, together with the fixed scroll  24 , sandwiches the orbiting scroll  26 . A second compressed refrigerant flow passage  48  is formed in, so as to run in the vertical direction through, the outer peripheral portion of the housing  23 . The second compressed refrigerant flow passage  48  communicates with the first compressed refrigerant flow passage  46  at the upper surface of the housing  23  and communicates with the high-pressure space S 1  at the lower surface of the housing  23 . 
     A crank chamber S 3  is recessedly provided in the upper surface of the housing  23 . A housing through hole  31  is formed in the housing  23 . The housing through hole  31  runs in the vertical direction through the housing  23  from the central portion of the bottom surface of the crank chamber S 3  to the central portion of the lower surface of the housing  23 . In this specification, the part of the housing  23  that has the housing through hole  31  formed in it is called an upper bearing  32 . In the housing  23  is formed an oil return passageway  23   a  that communicates the high-pressure space S 1  in the neighborhood of the inner surface of the casing  10  to the crank chamber S 3 . 
     (1-4) Oldham Coupling 
     The Oldham coupling  39  is an annular member installed between the orbiting scroll  26  and the housing  23 . The Oldham coupling  39  is a member for preventing self-rotation of the revolving orbiting scroll  26 . 
     (1-5) Drive Motor 
     The drive motor  16  is a brushless DC motor disposed under the housing  23 . The drive motor  16  is configured mainly from a stator  51  fixed to the inner surface of the casing  10  and a rotor  52  disposed inside the stator  51  with an air gap between them. 
     In the outer peripheral surface of the stator  51  are provided plural core cut portions comprising cutouts formed a predetermined interval apart from each other in the circumferential direction and ranging from the upper end surface of the stator  51  to the lower end surface. The core cut portions form motor cooling passageways  55  that extend in the vertical direction between the middle casing portion  11  and the stator  51 . 
     The rotor  52  is coupled to the crankshaft  17 , which runs in the vertical direction through the rotational center of the rotor  52 . The rotor  52  is connected via the crankshaft  17  to the compression mechanism  15 . 
     (1-6) Lower Bearing 
     The lower bearing  60  is disposed under the drive motor  16 . The outer peripheral surface of the lower bearing  60  is airtightly joined to the inner surface of the casing  10 . The lower bearing  60  supports the crankshaft  17 . 
     (1-7) Crankshaft 
     The crankshaft  17  is disposed in such a way that its axial direction lies along the vertical direction. The crankshaft  17  has a shape in which the axial center of the upper end portion of the crankshaft  17  is slightly eccentric with respect to the axial center of the portion excluding the upper end portion. The crankshaft  17  has a counterweight  18 . The counterweight  18  is tightly fixed to the crankshaft  17  at a height position under the housing  23  and above the drive motor  16 . 
     The crankshaft  17  runs in the vertical direction through the rotational center of the rotor  52  and is coupled to the rotor  52 . The upper end portion of the crankshaft  17  is fitted into the upper end bearing  26   c , whereby the crankshaft  17  is connected to the orbiting scroll  26 . The crankshaft  17  is supported by the upper bearing  32  and the lower bearing  60 . 
     The crankshaft  17  has inside a main oil supply passage  61  that extends in the axial direction of the crankshaft  17 . The upper end of the main oil supply passage  61  communicates with an oil chamber  67  formed by the upper end surface of the crankshaft  17  and the lower surface of the second end plate  26   a . The oil chamber  67  communicates with the sliding surface  24   d  and the oil groove  24   e  via the oil supply pore  63  in the second end plate  26   a  and finally communicates with the low-pressure space S 2  via the compression chamber  40 . The lower end of the main oil supply passage  61  is connected to an oil supply pipe that is a pipe for supplying to the compression mechanism  15  the lubricating oil stored in the oil reservoir  10   a.    
     The crankshaft  17  has a first auxiliary oil supply passage  61   a , a second auxiliary oil supply passage  61   b , and a third auxiliary oil supply passage  61   c  that branch from the main oil supply passage  61 . The first auxiliary oil supply passage  61   a , the second auxiliary oil supply passage  61   b , and the third auxiliary oil supply passage  61   c  extend in the horizontal direction. The first auxiliary oil supply passage  61   a  opens to the sliding surfaces of the crankshaft  17  and the upper end bearing  26   c  of the orbiting scroll  26 . The second auxiliary oil supply passage  61   b  opens to the sliding surfaces of the crankshaft  17  and the upper bearing  32  of the housing  23 . The third auxiliary oil supply passage  61   c  opens to the sliding surfaces of the crankshaft  17  and the lower bearing  60 . 
     (1-8) Suction Pipe 
     The suction pipe  19  is a pipe for introducing the refrigerant in the refrigerant circuit from the outside of the casing  10  to the compression mechanism  15 . The suction pipe  19  is airtightly fitted into the upper wall portion  12  of the casing  10 . The suction pipe  19  runs in the vertical direction through the low-pressure space S 2 . 
     (1-9) Discharge Pipe 
     The discharge pipe  20  is a pipe for discharging the compressed refrigerant from the high-pressure space S 1  to the outside of the casing  10 . The discharge pipe  20  is airtightly fitted into the middle casing portion  11  of the casing  10 . The discharge pipe  20  runs in the horizontal direction through the high-pressure space S 1 . 
     (2) Details of Fixed Scroll and Orbiting Scroll 
       FIG. 2  is a bottom view of the fixed scroll  24  seen along the vertical direction. Plural regions are formed in a refrigerant flow passage portion  24   f  of the fixed scroll  24  from the main suction hole  24   c  to the discharge hole  41 . In the present embodiment, four regions are formed. Namely, a first region  34   a , a second region  34   b , a third region  34   c , and a fourth region  34   d  are formed. 
     The first region  34   a  is a region on the innermost peripheral side of the refrigerant flow passage portion  24   f . In the present embodiment, the first region  34   a  is a region corresponding to a range from the center  24   p  of the first wrap  24   b  (i.e., the start of the spiral) to 540°. In the present embodiment, the range from the center  24   p  of the first wrap  24   b  to 540° is defined as the center portion of the first wrap  24   b , and the first region  34   a  is defined as the center portion of the first end plate  24   a . The center portions of the first wrap  24   b  and the first end plate  24   a  form a center portion of the compression chamber  40 . 
     The second region  34   b  is a region continuous with the first region  34   a . The second region  34   b  is a region between the first region  34   a  and the third region  34   c . In the present embodiment, the second region  34   b  is a region corresponding to a range from 540° of the first wrap  24   b  to 720°. 
     The third region  34   c  is a region continuous with the second region  34   b . The third region  34   c  is a region between the second region  34   b  and the fourth region  34   d . In the present embodiment, the third region  34   c  is a region corresponding to a range from 720° of the first wrap  24   b  to 900°. 
     The fourth region  34   d  is a region continuous with the third region  34   c . The fourth region  34   d  is a region on the outermost peripheral side of the refrigerant flow passage portion  24   f . In the present embodiment, the fourth region  34   d  is a region corresponding to a range from 900° of the first wrap  24   b  to the outer peripheral end (1080°). 
     In the present embodiment, the range from 540° of the first wrap  24   b  to the outer peripheral end is defined as the non-center portion of the first wrap  24   b , and the second region  34   b , the third region  34   c , and the fourth region  34   d  are defined as the non-center portion of the first end plate  24   a . The non-center portions of the first wrap  24   b  and the first end plate  24   a  form a non-center portion of the compression chamber  40 . 
       FIG. 3  is a top view of the orbiting scroll  26  seen along the vertical direction. Plural regions are formed in a refrigerant flow passage portion  26   f  of the orbiting scroll  26  surrounded from the center  26   p  of the second wrap  26   b  to the outer peripheral end. In the present embodiment, four regions are formed. Namely, a first region  36   a , a second region  36   b , a third region  36   c , and a fourth region  36   d  are formed. 
     The first region  36   a  is a region on the innermost peripheral side of the refrigerant flow passage portion  26   f . In the present embodiment, the first region  36   a  is a region corresponding to a range from the center  26   p  of the second wrap  26   b  (i.e., the start of the spiral) to 540°. In the present embodiment, the range from the center  26   p  of the second wrap  26   b  to 540° is defined as the center portion of the second wrap  26   b , and the first region  36   a  is defined as the center portion of the second end plate  26   a . The center portions of the second wrap  26   b  and the second end plate  26   a  form the center portion of the compression chamber  40 . 
     The second region  36   b  is a region continuous with the first region  36   a . The second region  36   b  is a region between the first region  36   a  and the third region  36   c . In the present embodiment, the second region  36   b  is a region corresponding to a range from 540° of the second wrap  26   b  to 660°. 
     The third region  36   c  is a region continuous with the second region  36   b . The third region  36   c  is a region between the second region  36   b  and the fourth region  36   d . In the present embodiment, the third region  36   c  is a region corresponding to a range from 660° of the second wrap  26   b  to 780°. 
     The fourth region  36   d  is a region continuous with the third region  36   c . The fourth region  36   d  is a region on the outermost peripheral side of the refrigerant flow passage portion  26   f . In the present embodiment, the fourth region  36   d  is a region corresponding to a range from 780° of the second wrap  26   b  to the outer peripheral end (900°). 
     In the present embodiment, the range from 540° of the second wrap  26   b  to the outer peripheral end is defined as the non-center portion of the second wrap  26   b , and the second region  36   b , the third region  36   c , and the fourth region  36   d  are defined as the non-center portion of the second end plate  26   a . The non-center portions of the second wrap  26   b  and the second end plate  26   a  form the non-center portion of the compression chamber  40 . 
       FIG. 4A  is a drawing describing the first gap that is a gap between the first wrap  24   b  and the second end plate  26   a . In  FIG. 4A , the horizontal axis represents the angle from the center  26   p  of the second wrap  26   b . The vertical axis represents the height of the first gap. Namely, the vertical axis represents the distance between the distal end of the first wrap  24   b  and the second end plate  26   a  (particularly the refrigerant flow passage portion  26   f ). Gap height h 1  represents the distance between the distal end of the first wrap  24   b  and the first region  36   a . Gap height h 2  represents the distance between the distal end of the first wrap  24   b  and the second region  36   b . Gap height h 3  represents the distance between the distal end of the first wrap  24   b  and the third region  36   c . Gap height h 4  represents the distance between the distal end of the first wrap  24   b  and the fourth region  36   d.    
     As shown in  FIG. 4A , the height of the refrigerant flow passage portion  26   f  changes heading from the outer peripheral side to the inner peripheral side. The height of the refrigerant flow passage portion  26   f  becomes lower heading from the outer peripheral side to the inner peripheral side. Namely, the thickness of the refrigerant flow passage portion  26   f  becomes thinner. In the present embodiment, the height of the refrigerant flow passage portion  26   f  becomes lower in a stepwise manner heading from the outer peripheral side toward the inner peripheral side. More specifically, the height of the refrigerant flow passage portion  26   f  becomes lower in the order of the fourth region  36   d , the third region  36   c , the second region  36   b , and the first region  36   a.    
     Three step portions  66  are formed in the refrigerant flow passage portion  26   f  as a result of the refrigerant flow passage portion  26   f  becoming lower in a stepwise manner. Namely, a step portion  66   a  is formed at the boundary between the second region  36   b  and the first region  36   a , a step portion  66   b  is formed at the boundary between the third region  36   c  and the second region  36   b , and a step portion  66   c  is formed at the boundary between the fourth region  36   d  and the third region  36   c.    
     In contrast, the height of the first wrap  24   b  is constant. As a result, the height of the first gap changes heading from the outer peripheral side of the first wrap  24   b  to the inner peripheral side. The height of the first gap becomes wider heading from the outer peripheral side of the first wrap  24   b  to the inner peripheral side. The height of the first gap changes in a stepwise manner. Gap height h 1  is the largest, and gap height h 4  is the smallest. 
     As described above, the height of the refrigerant flow passage portion  26   f  changes, while the height of the first wrap  24   b  is constant. Consequently, the amount of change in the height of the refrigerant flow passage portion  26   f  can be understood as the amount of change in the first gap itself. 
     In the present embodiment, the center portion of the second end plate  26   a  includes the step portion  66   a . Consequently, the gap heights at the outer peripheral end (i.e., the step portion  66   a ) and the inner peripheral end of the center portion of the second end plate  26   a  differ. Specifically, they differ by the difference between gap height h 1  and gap height h 2 . The height of the step portion  66   a  is h 1 -h 2 . 
     In the present embodiment, the non-center portion of the second end plate  26   a  includes two step portions. Namely, the non-center portion of the second end plate  26   a  includes the step portion  66   b  and the step portion  66   c . The height of the step portion  66   b  is h 2 -h 3 , and the height of the step portion  66   c  is h 3 -h 4 . 
       FIG. 4B  is a drawing describing the second gap that is a gap between the first end plate  24   a  and the second wrap  26   b . In  FIG. 4B , the horizontal axis represents the angle from the center  24   p  of the first wrap  24   b . The vertical axis represents the height of the second gap. Namely, the vertical axis represents the distance between the first end plate  24   a  (particularly the refrigerant flow passage portion  24   f ) and the distal end of the second wrap  26   b . Gap height h 5  represents the distance between the distal end of the second wrap  26   b  and the first region  34   a . Gap height h 6  represents the distance between the distal end of the second wrap  26   b  and the second region  34   b . Gap height h 7  represents the distance between the distal end of the second wrap  26   b  and the third region  34   c . Gap height h 8  represents the distance between the distal end of the second wrap  26   b  and the fourth region  34   d.    
     As shown in  FIG. 4B , the height of the refrigerant flow passage portion  24   f  changes heading from the outer peripheral side to the inner peripheral side. The height of the refrigerant flow passage portion  24   f  becomes lower heading from the outer peripheral side toward the inner peripheral side. Namely, the thickness of the refrigerant flow passage portion  24   f  becomes thinner. In the present embodiment, the height of the refrigerant flow passage portion  24   f  becomes lower in a stepwise manner heading from the outer peripheral side toward the inner peripheral side. More specifically, the height of the refrigerant flow passage portion  24   f  becomes lower in the order of the fourth region  34   d , the third region  34   c , the second region  34   b , and the first region  34   a.    
     Three step portions  64  are formed in the refrigerant flow passage portion  24   f  as a result of the refrigerant flow passage portion  24   f  becoming lower in a stepwise manner. Namely, a step portion  64   a  is formed at the boundary between the second region  34   b  and the first region  34   a , a step portion  64   b  is formed at the boundary between the third region  34   c  and the second region  34   b , and a step portion  64   c  is formed at the boundary between the fourth region  34   d  and the third region  34   c.    
     In contrast, the height of the second wrap  26   b  is constant. As a result, the height of the second gap changes heading from the outer peripheral side to the inner peripheral side of the second wrap  26   b . The height of the second gap becomes wider heading from the outer peripheral side to the inner peripheral side of the second wrap  26   b . The height of the second gap changes in a stepwise manner. Gap height h 5  is the largest, and gap height h 8  is the smallest. 
     As described above, the height of the refrigerant flow passage portion  24   f  changes, while the height of the second wrap  26   b  is constant. Consequently, the amount of change in the height of the refrigerant flow passage portion  24   f  can be understood as the amount of change in the second gap itself. 
     In the present embodiment, the center portion of the first end plate  24   a  includes the step portion  64   a . Consequently, the gap heights at the outer peripheral end (i.e., the step portion  64   a ) and the inner peripheral end of the center portion of the first end plate  24   a  differ. Specifically, they differ by the difference between gap height h 5  and gap height h 6 . The height of the step portion  64   a  is h 5 -h 6 . 
     In the present embodiment, the non-center portion of the first end plate  24   a  includes two step portions. Namely, the non-center portion of the first end plate  24   a  includes the step portion  64   b  and the step portion  64   c . The height of the step portion  64   b  is h 6 -h 7 , and the height of the step portion  64   c  is h 7 -h 8 . 
       FIG. 5A  is a drawing describing the change in the height of the first gap. In  FIG. 5A , the horizontal axis represents the angle of the second wrap  26   b , and the vertical axis represents the height of the first gap. Here, gap height h 4  is defined as a reference for the gap height. Furthermore, as an example, the height of the step portion  66   c  is defined as 1 μm, the height of the step portion  66   b  is defined as 9 μm, and the height of the step portion  66   a  is defined as 26 μm. In that case, gap height h 3  can be expressed as h 4 +1, gap height h 2  can be expressed as h 4 +10, and gap height h 1  can be expressed as h 4 +36. 
     In the present embodiment, the amount of change at the center portion of the second end plate  26   a  is h 1 -h 2 =26 μm. The number of steps in the center portion of the second end plate  26   a  is 1, so the rate of change at the center portion of the second end plate  26   a  is 26. The amount of change at the non-center portion of the second end plate  26   a  is h 2 -h 4 =10 μm. The number of steps in the non-center portion of the second end plate  26   a  is 2, so the rate of change at the non-center portion of the second end plate  26   a  (the average of the amount of change per step) is 10/2=5. 
     As described above, the rate of change in the first gap at the center portion of the second end plate  26   a  is greater than the rate of change in the first gap at the non-center portion of the second end plate  26   a . More specifically, the rate of change in the first gap at the center portion of the second end plate  26   a  is 5.2 times the rate of change in the first gap at the non-center portion of the second end plate  26   a . The first gap becomes locally larger in the range of the center portion of the second end plate  26   a . It will be noted that preferably the rate of change in the first gap at the center portion of the second end plate  26   a  is in the range of 4.5 times to 5.5 times the rate of change in the first gap at the non-center portion of the second end plate  26   a.    
       FIG. 5B  is a drawing describing the change in the height of the second gap. In  FIG. 5B , the horizontal axis represents the angle of the first wrap  24   b , and the vertical axis represents the height of the second gap. Here, gap height h 8  is defined as a reference for the gap height. Furthermore, as an example, the height of the step portion  64   c  is defined as 1 μm, the height of the step portion  64   b  is defined as 9 μm, and the height of the step portion  64   a  is defined as 26 μm. In that case, gap height h 7  can be expressed as h 8 +1, gap height h 6  can be expressed as h 8 +10, and gap height h 5  can be expressed as h 8 +36. 
     In the present embodiment, the amount of change at the center portion of the first end plate  24   a  is h 5 -h 6 =26 μm. The number of steps in the center portion of the first end plate  24   a  is 1, so the rate of change at the center portion of the first end plate  24   a  is 26. The amount of change at the non-center portion of the first end plate  24   a  is h 6 -h 8 =10 μm. The number of steps in the non-center portion of the first end plate  24   a  is 2, so the rate of change at the non-center portion of the first end plate  24   a  (the average of the amount of change per step) is 10/2=5. 
     As described above, the rate of change in the second gap at the center portion of the first end plate  24   a  is greater than the rate of change in the second gap at the non-center portion of the first end plate  24   a . More specifically, the rate of change in the second gap at the center portion of the first end plate  24   a  is 5.2 times the rate of change in the second gap at the non-center portion of the first end plate  24   a . The second gap becomes locally larger in the range of the center portion of the first end plate  24   a . It will be noted that preferably the rate of change in the second gap at the center portion of the first end plate  24   a  is in the range of 4.5 times to 5.5 times the rate of change in the second gap at the non-center portion of the first end plate  24   a.    
     (3) Operation of Scroll Compressor 
     First, the rotor  52  is rotated by the driving of the drive motor  16 . Because of this, the crankshaft  17  fixed to the rotor  52  rotates. The rotational movement of the crankshaft  17  is transmitted via the upper end bearing  26   c  to the orbiting scroll  26 . The axial center of the upper end portion of the crankshaft  17  is eccentric with respect to the axis of the rotational movement of the crankshaft  17 . The orbiting scroll  26  is engaged with the housing  23  via the Oldham coupling  39 . Because of this, the orbiting scroll  26  performs revolving movement with respect to the fixed scroll  24  without self-rotating. 
     The low-temperature low-pressure refrigerant before being compressed is supplied from the suction pipe  19  via the main suction hole  24   c  to the compression chamber  40  of the compression mechanism  15 . Because of the revolving movement of the orbiting scroll  26 , the compression chamber  40  moves from the outer peripheral portion of the fixed scroll  24  to the center portion while its volume is gradually decreased. As a result, the refrigerant in the compression chamber  40  is compressed and becomes compressed refrigerant. When the compression chamber  40  moves from the outer peripheral portion of the fixed scroll  24  # to the center portion, the temperature of the compression chamber  40  rises in accompaniment with the move. Particularly in a case where the refrigerant is compressed in a high-load condition, the temperature rises more. In accompaniment with the rise in temperature, the fixed scroll  24  and the orbiting scroll  26  expand. 
     Here, in the scroll compressor  101  of the present embodiment, the first gap and the second gap are locally large at the center portion of the compression chamber  40 , which is more susceptible to the effects of heat. Consequently, even if the fixed scroll  24  and the orbiting scroll  26  expand due to heat, contact between the fixed scroll  24  and the orbiting scroll  26  can be inhibited. 
     The compressed refrigerant is discharged from the discharge hole  41  to the muffler space  45  and thereafter is discharged via the first compressed refrigerant flow passage  46  and the second compressed refrigerant flow passage  48  to the high-pressure space S 1 . Then, the compressed refrigerant descends through the motor cooling passageways  55  and reaches the high-pressure space S 1  under the drive motor  16 . Then, the compressed refrigerant reverses its flow direction and ascends through other motor cooling passageways  55  and the air gap in the drive motor  16 . Finally, the compressed refrigerant is discharged from the discharge pipe  20  to the outside of the scroll compressor  101 . 
     (4) Characteristics of Scroll Compressor 
     In the scroll compressor  101  of the present embodiment, the rate of change in the first gap at the center portion of the second end plate  26   a  is greater than the rate of change in the first gap at the non-center portion of the second end plate  26   a . The first gap in the range of the center portion of the second end plate  26   a  becomes locally larger. Consequently, in the center portion of the second end plate  26   a , contact between the distal end of the first wrap  24   b  and the second end plate  26   a  can be inhibited. The first gap at the center portion of the first wrap  24   b  is set to become locally larger in anticipation of the expansion of the first wrap  24   b  due to heat at the center portion of the compression chamber  40 , which can reach a particularly high temperature, so contact between the fixed scroll  24  and the orbiting scroll  26  at the center portion of the compression chamber  40  can be inhibited. 
     In the same way, the rate of change in the second gap at the center portion of the first end plate  24   a  is greater than the rate of change in the second gap at the non-center portion of the first end plate  24   a . The second gap in the range of the center portion of the first end plate  24   a  becomes locally larger. Consequently, at the center portion of the first end plate  24   a , contact between the distal end of the second wrap  26   b  and the first end plate  24   a  can be inhibited. The second gap at the center portion of the second wrap  26   b  is set to become locally larger in anticipation of the expansion of the second wrap  26   b  due to heat # at the center portion of the compression chamber  40 , which can reach a particularly high temperature, so contact between the fixed scroll  24  and the orbiting scroll  26  at the center portion of the compression chamber  40  can be inhibited. 
     In the scroll compressor  101  of the present embodiment, the first gap changes in a stepwise manner heading from the outer peripheral side of the first wrap  24   b  # to the inner peripheral side. The second gap changes in a stepwise manner heading from the outer peripheral side of the second wrap  26   b  # to the inner peripheral side. The first gap and the second gap gradually change heading toward the center portion of the compression chamber  40 , so contact between the fixed scroll  24  and the orbiting scroll  26  can be effectively inhibited. 
     In the scroll compressor  101  of the present embodiment, the second end plate  26   a  includes the step portion  66   a  in the range of the center portion of the first wrap  24   b , and the first end plate  24   a  includes the step portion  64   a  in the range of the center portion of the second wrap  26   b . Because of the step portion  66   a , the first gap at the center portion of the second end plate  26   a  can easily be made locally larger. In the same way, because of the step portion  64   a , the second gap at the center portion of the first end plate  24   a  can easily be made locally larger. 
     In the scroll compressor  101  of the present embodiment, the second end plate  26   a  is formed in a stepwise manner, whereby the first gap changes in a stepwise manner heading from the outer peripheral side of the first wrap  24   b  # to the inner peripheral side. The first end plate  24   a  is formed in a stepwise manner, whereby the second gap changes in a stepwise manner heading from the outer peripheral side of the second wrap  26   b  # to the inner peripheral side. Thus, compared to a case where the second end plate  26   a  and the first end plate  24   a  are formed in a sloping manner, processing for forming the first gap and the second gap becomes easy. 
     In the scroll compressor  101  of the present embodiment, the center portion of the first wrap  24   b  is a range from the center of the first wrap  24   b  to 540°. The center portion of the second wrap  26   b  is a range from the center of the second wrap  26   b  to 540°. The first gap in the range from the center of the first wrap  24   b  to 540° and the second gap in the range from the center of the second wrap  26   b  to 540°, which can reach a particularly high temperature, are made locally larger, so contact between the fixed scroll  24  and the orbiting scroll  26  can be effectively inhibited. 
     In the scroll compressor  101  of the present embodiment, the rate of change in the first gap at the center portion of the second end plate  26   a  is in the range of 4.5 times to 5.5 times the rate of change in the first gap at the non-center portion of the second end plate  26   a.  The rate of change in the second gap at the center portion of the first end plate  24   a  is in the range of 4.5 times to 5.5 times the rate of change in the second gap at the non-center portion of the first end plate  24   a . Because of the above, contact between the fixed scroll  24  and the orbiting scroll  26  can be effectively inhibited. 
     In the scroll compressor  101  of the present embodiment, the fixed scroll  24  and the orbiting scroll  26  compress refrigerant that includes more than 50 wt % R32 as refrigerant. When R410A refrigerant and refrigerant that includes more than 50 wt % R32 are compressed under the same conditions, the refrigerant that includes more than 50 wt % R32 reaches a higher temperature than the R410A refrigerant. That is, it becomes easier for the first wrap  24   b  and the second wrap  26   b  to deform. Even in a case such as this, the scroll compressor  101  satisfies the first condition and the second condition, so contact between the fixed scroll  24  and the orbiting scroll  26  can be inhibited. 
     Example modifications applicable to the embodiment of the invention will be described. 
     (1) Example Modification A 
     In the above description, the second end plate  26   a  is formed in a stepwise manner, but the configuration whereby the first gap changes in a stepwise manner heading from the outer peripheral side of the first wrap  24   b  to the inner peripheral side is not limited to this. The first wrap  24   b  may also be formed in a stepwise manner, or the first wrap  24   b  and the second end plate  26   a  may also be formed in a stepwise manner. Namely, it suffices for at least one of the first wrap  24   b  and the second end plate  26   a  to be formed in a stepwise manner. It suffices for at least one of the first wrap  24   b  and the second end plate  26   a  to include a step portion in the range of the center portion of the first wrap  24   b.    
     In the same way, in the above description, the first end plate  24   a  is formed in a stepwise manner, but the configuration whereby the second gap changes in a stepwise manner heading from the outer peripheral side of the second wrap  26   b  to the inner peripheral side is not limited to this. The second wrap  26   b  may also be formed in a stepwise manner, or the second wrap  26   b  and the first end plate  24   a  may also be formed in a stepwise manner. Namely, it suffices for at least one of the second wrap  26   b  and the first end plate  24   a  to be formed in a stepwise manner. It suffices for at least one of the second wrap  26   b  and the first end plate  24   a  to include a step portion in the range of the center portion of the second wrap  26   b.    
     (2) Example Modification B 
     In the above description, three step portions are formed in each of the refrigerant flow passage portion  24   f  and the refrigerant flow passage portion  26   f , but two step portions may also be formed, or four or more step portions may also be formed. 
     (3) Example Modification C 
     In the above description, the center portion of the first end plate  24   a  is a range from the center of the first wrap  24   b  to 540°, but the range of the center portion of the first end plate  24   a  is not limited to this. The range of the center portion of the first end plate  24   a  may also change in accordance with the number of step portions. For example, in a case where four step portions are formed in the refrigerant flow passage portion  24   f , the center portion of the first end plate  24   a  may also be a range from the center of the first wrap  24   b  to 360°. 
     In the same way, the center portion of the second end plate  26   a  is a range from the center of the second wrap  26   b  to 540°, but the range of the center portion of the second end plate  26   a  is not limited to this. The range of the center portion of the second end plate  26   a  may also change in accordance with the number of step portions. For example, in a case where four step portions are formed in the refrigerant flow passage portion  26   f , the center portion of the second end plate  26   a  may also be a range from the center of the second wrap  26   b  to 360°. 
     (4) Example Modification D 
     In the above description, the center portion of the first end plate  24   a  and the center portion of the second end plate  26   a  each have one step portion, but the configuration of the center portion of the first end plate  24   a  and the center portion of the second end plate  26   a  is not limited to this. The center portion of the first end plate  24   a  and the center portion of the second end plate  26   a  may also each have two or more step portions. Namely, it suffices for the center portion of the first end plate  24   a  and the center portion of the second end plate  26   a  to each include at least one step portion. 
     (5) Example Modification E 
     In the above description, the first gap and the second gap change in a stepwise manner, but the configuration of the first gap and the second gap is not limited to changing in a stepwise manner. The first gap and the second gap may also change in a sloping manner. 
     (6) Example Modification F 
     In the above description, the scroll compressor  101  satisfies both the first condition and the second condition, but the scroll compressor  101  may also satisfy just the first condition or may also satisfy just the second condition. Namely, it suffices for the scroll compressor  101  to satisfy at least one of the first condition and the second condition. More specifically, just the first gap at the center portion of the compression chamber  40  may become locally larger, or just the second gap at the center portion of the compression chamber  40  may become locally larger. Namely, it suffices for the gap at the center portion of the compression chamber  40  to become locally larger in at least one of the first gap and the second gap. By satisfying at least one of the first condition and the second condition, contact between the fixed scroll  24  and the orbiting scroll  26  can be inhibited. 
     (7) Example Modification G 
     In the above description, the change in the height of the first gap is the same as the change in the height of the second gap, but the change in the height of the first gap may also be different from the change in the height of the second gap. 
     The invention has been described above using an embodiment, but the technical scope of the invention is not limited to the scope described in the above embodiment. It will be apparent to persons skilled in the art that various changes or improvements can be made to the above embodiment. That embodiments to which such changes or improvements have been made can also be included in the technical scope of the invention will be apparent from the description of the scope of the claims.