JP2005344654A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the efficiency of a compressor by reducing the heating loss thereof and, when the compressor is used as a refrigerant compressor, increase the efficiency of a refrigerating cycle by lowering the temperature of the delivery refrigerant. <P>SOLUTION: In this compressor 1 having a discharge chamber 40 and a suction chamber 38 adjacent to each other, a partial insulator 11 is formed in a partition wall 37 between the discharge chamber and the suction chamber 38 without forming an insulator on the inner and outer surfaces of the portion 10 of a wall surrounding the discharge chamber 40 which has an outer surface in contact with the outside air. Thus, the heat of the delivery refrigerant can be dissipated to the outside air and the amount of heat absorbed by the suction refrigerant can be reduced. Also, the conduction of heat to the suction refrigerant is desirably be stopped by forming an insulator 64 on the inner surface of the suction chamber 38. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a compressor, and more particularly to a compressor suitable for use as a refrigerant compressor that is used in an air conditioner or the like and compresses a refrigerant such as CO ₂ .

  In the conventional refrigerant compressor, the heat of the discharged refrigerant discharged to the discharge chamber by being compressed is conducted by the wall of the housing made of aluminum alloy having a good thermal conductivity, etc. As a result, the temperature of the intake refrigerant rises due to absorption by the low-temperature intake refrigerant, and so-called “heating loss” occurs due to a decrease in density. As a result, the efficiency of the compressor is lowered.

  To solve this problem, as described in Patent Document 1 and Patent Document 2 below, the inner wall surface of the discharge chamber filled with the high-temperature discharge refrigerant or the inside of the suction chamber through which the low-temperature intake refrigerant passes. Covering the wall surface etc. with a heat insulating material, it is difficult for the heat of the discharged refrigerant to be conducted to the housing, or even if the heat is conducted to the housing, the heat is not easily absorbed by the drawn refrigerant passing through the suction chamber. It is considered.

JP-T-2001-515174 JP 2003-214345 A

  However, if the inner wall surface of the discharge chamber is completely covered with a heat insulating material, the amount of heat absorbed by the suction refrigerant is reduced by conduction from the discharge refrigerant to the housing through the wall surface of the discharge chamber, and the temperature of the suction refrigerant is lowered. Since the so-called heating loss is reduced and the efficiency of the compressor is increased because the heat can be maintained, the temperature of the discharged refrigerant itself (discharge temperature) is reduced because the heat of the discharged refrigerant is not released from the wall surface of the discharge chamber. Since it is maintained at a high state, the temperature of the refrigerant flowing into the condenser or the gas cooler becomes high, resulting in another problem that the cycle efficiency of the entire refrigeration cycle is lowered.

  In view of the problems in the conventional compressor as described above, the present invention prevents a decrease in the efficiency of the compressor due to a rise in the temperature of the suction refrigerant and, at the same time, a problem of a decrease in the efficiency of the refrigeration cycle that occurs. The purpose is to solve.

  In order to solve the above-mentioned problems, the present invention provides a compressor having a configuration as described in claim 1. In this compressor, the suction chamber and the discharge chamber are provided adjacent to each other, and at least the inner surface on the discharge chamber side of the portion surrounding the discharge chamber that is a partition wall with the suction chamber is insulated. A material is provided, and a heat insulating material is not provided on the inner surface and the outer surface on the discharge chamber side in at least a part of the portion of the wall surrounding the discharge chamber that is in contact with the outside air. .

  In this compressor, since heat insulation is not provided on the inner surface and the outer surface on the discharge chamber side in at least a part of the portion of the wall surrounding the discharge chamber that the outer surface is in contact with the outside air, it is heated by being compressed. Since the discharge fluid in the discharge chamber at a high pressure exchanges heat with the outside air through the wall portion where the heat insulating material is not provided on the inner surface and the outer surface, a part of the heat of the discharge fluid is dissipated into the outside air. Not only does the temperature of the discharge fluid decrease and the volume decreases, but also the amount of heat that is transferred to the suction chamber through the wall and heats the suction fluid before compression decreases. Can be suppressed. As a result, the heating loss of the compressor is reduced and the efficiency is increased.

  Further, when a heat insulating material is provided on the inner surface of the wall surrounding the suction chamber on the suction chamber side, even if the heat of the discharge fluid is transmitted to the wall of the suction chamber, the suction fluid inside the suction chamber is caused by the heat. Is hardly heated, the above-mentioned effect is further enhanced.

  The present invention can be particularly suitably applied to a piston type compressor such as a swash plate type compressor. In a piston-type compressor, a discharge chamber and a suction chamber are often provided adjacent to each other through a partition wall at the end of the housing, so it is necessary to prevent the heat of the discharge fluid from being absorbed by the suction fluid. Because there is.

The compressor of the present invention is suitable for use as a refrigerant compressor for compressing refrigerant in an air conditioner, but is suitable for compressing so-called supercritical pressure fluid such as CO ₂ as refrigerant among refrigerant compressors. ing. When compressing a supercritical pressure fluid as a refrigerant, the compression pressure is much higher than when using a refrigerant such as chlorofluorocarbon, so the temperature difference between the refrigerant discharged from the compressor and the intake refrigerant also increases. This is because it is very effective to provide a heat insulating means between them.

  As a means for providing a heat insulating material on the inner surface or outer surface of the wall of the discharge chamber or the suction chamber, a heat insulating paint is applied to the wall surface, or a solid heat insulating material such as a foamed resin is formed in the discharge chamber or the suction chamber. Any of the methods such as press fitting, molding the insulation directly on the inner or outer surface of the wall, etc., can be selected or a combination of these means. When the heat insulating paint is applied, the thickness of the heat insulating material is reduced, so that the volume of the discharge chamber or the like is hardly reduced.

  Hereinafter, the structure of the compressor 1 of the first embodiment which is the best mode of the present invention will be described in detail with reference to FIGS. Even though the compressor 1 of the first embodiment is mostly the same as that of the compressor according to the prior art, with respect to the reference numerals attached to the drawings for explanation, the embodiment of the present invention, For comparison, in any of the conventional compressors described later, substantially the same components will be denoted by the same reference numerals.

  The compressor 1 of the first embodiment shown in FIGS. 1 and 2 is a so-called “swash plate type variable capacity compressor”, and its housing or outer shell is formed of several parts made of a metal such as an aluminum alloy. That is, it is composed of a front housing 31 at the front end, an intermediate cylinder block 32, and a rear housing 33 at the rear end. These housing components are fastened together by means such as through bolts (not shown) and integrated.

  Between the cylinder block 32 and the rear housing 33, a valve plate 34 made of a thick plate material and a suction valve plate 35 made of a thin spring steel plate sandwiched along the front surface are interposed. Although not shown in detail, the suction valve plate 35 is formed with a cantilever lead piece that forms a suction valve that closes the suction port 39 that opens to the valve plate 34 by punching a part of the suction valve plate 35. Reference numeral 36 denotes a discharge valve plate made of a thin spring steel plate, which, like the suction valve plate 35, also has a plurality of pieces serving as a discharge valve for closing the discharge port 41 opened in the valve plate 34. In order to form a possessed lead piece, it is provided along the rear surface of the valve plate 34.

  The inner space of the rear housing 33 is divided into two parts, an inner part and an outer part, by an annular partition wall 37 as shown in FIG. An annular space outside thereof constitutes a suction chamber 38, and a suction port 44 provided in the suction chamber 38 opens to the outside and communicates with an evaporator in a refrigerating cycle of an air conditioner (not shown). . Then, a refrigerant (generally a fluid) to be compressed is introduced into the suction chamber 38 as shown by an arrow A shown in FIG. The so-called “return refrigerant” introduced in this way is usually at a low pressure and a low temperature.

  In the case of the compressor 1 of the first embodiment, the central circular portion of the internal space of the rear housing 33 constitutes the discharge chamber 40. The discharge chamber 40 communicates with a condenser (or a gas cooler) in the refrigeration cycle (not shown) via a discharge port 45 that opens to the outside and a pipe (not shown). Therefore, after the high-pressure and high-temperature discharge refrigerant compressed by the compressor 1 is filled in the discharge chamber 40, it is sent out from the discharge port 45 to the refrigeration cycle through the piping as indicated by an arrow A shown in FIG. A discharge valve plate 36 in which a plurality of cantilevered lead pieces described above are formed by bolts 42 screwed into the female screw holes of the valve plate 34 and the lead pieces thereof are provided at the center of the discharge chamber 40. A star-shaped valve retainer 43 (see FIG. 2) that prevents and protects the lens from excessive deformation is screwed.

  In the illustrated embodiment, the cylinder block 32 is formed with five cylinder bores 46 in parallel with each other as shown in FIG. Pistons 47 are slidably inserted into the cylinder bores 46, and their front ends are slidably engaged with a common swash plate 48 having a generally disk shape through a shoe 49 from the front and back. ing. A drive shaft 52 parallel to the piston 47 is pivotally supported by a radial bearing 50 provided in the front housing 31 and a radial bearing 51 provided in the cylinder block 32, and the opening at the center of the swash plate 48 is the drive shaft. 52 so that it can be inclined with respect to 52.

  A drive plate 53 provided at right angles to the drive shaft 52 and integrally therewith is supported by the front housing 31 via a radial bearing 54 and a thrust bearing 55. A pair of coil springs 56 and 57 wound around the drive shaft 52 engage with the front and rear of the swash plate 48, and always urge the swash plate 48 in a direction perpendicular to the drive shaft 52.

  An arm 57 extending forward from a part of the swash plate 48 is formed with a long hole 58 that acts as a cam. An arm 60 having a pin 59 that engages with the elongated hole 58 projects rearward from a part of the drive plate 53 described above. By the link mechanism composed of such portions, the swash plate 48 can be freely tilted with respect to the drive plate 53, but is rotationally driven integrally with the drive plate 53 and the drive shaft 52 in the rotation direction. The drive plate 53 is connected.

  1 is a shaft seal provided at a portion where the drive shaft 52 penetrates the front housing 31, and the control pressure chamber 62 in which the swash plate 48 is accommodated is sealed against the outside air. ing. The control pressure chamber 62 communicates with the suction chamber 38 and the discharge chamber 40 via a pressure control valve (not shown), and a refrigerant having an arbitrary height intermediate between the low pressure of the suction chamber 38 and the high pressure of the discharge chamber 40. The pressure is introduced and becomes the back pressure of all the pistons 47.

  On the other hand, when the drive shaft 52 is rotated by an external power source such as an internal combustion engine and the piston 47 rotates the swash plate 48 via the link mechanism including the arms 57 and 60, the piston 47 has an inclination angle of the swash plate 48. The piston 47 reciprocates with a stroke of a corresponding size to compress the refrigerant, pressurize the low-pressure refrigerant in the suction chamber 38 and discharge it to the discharge chamber 40. As a reaction by the piston 47 compressing the refrigerant, A compression reaction force acts on the piston 47 and moves backward toward the control pressure chamber 62 to increase the inclination angle of the swash plate 48. The retraction of the piston 47 is prevented by the pressure in the control pressure chamber 62 acting as the back pressure of the piston 47, and therefore, in the state where the compression reaction force acting on all the pistons 47 and the axial force due to the back pressure are balanced. The inclination angle of the plate 48 is determined. Therefore, when the pressure of the control pressure chamber 62 is changed by controlling the pressure control valve by an electronic control device or the like (not shown), the inclination angle of the swash plate 48 changes, and the discharge capacity of the compressor changes steplessly. It will be.

  The above description is not a description of the swash plate type variable displacement compressor 1 of the illustrated embodiment, but rather a configuration and an action common to a conventionally well known swash plate type variable displacement compressor. Therefore, the above description can be applied to the operation of the conventional swash plate type variable capacity compressor 2 illustrated in FIGS. 3 and 4 as it is. Further, the present invention is not characterized by the basic operation of the swash plate type variable capacity compressor, and is not limited to the swash plate type variable capacity compressor. A more detailed description of the operation of the variable capacity compressor is omitted. As is clear from this description, in the compression process from the pressurization of the refrigerant (generally fluid) in the suction chamber 38 to the discharge into the discharge chamber 40, the present invention provides an arbitrary type of compressor mechanism. Can be used.

  In the conventional swash plate type variable displacement compressor 2 shown in FIG. 3 and FIG. 4, the refrigerant compressed by the reciprocation of the piston 47 and discharged into the discharge chamber 40 is compressed as described above. Therefore, a large amount of heat is conducted as indicated by the thick arrow b through the wall of the rear housing 33 made of aluminum alloy or the like, and is absorbed by the low-temperature suction refrigerant in the suction chamber 44. Is done. Since the temperature of the refrigerant sucked before being pressurized by the heat rises, the compressor compresses the refrigerant having a reduced density (increase in volume), so-called “heating loss” occurs, and as a result The efficiency of the compressor is reduced.

  As a countermeasure against this problem, in the prior art, heat is transferred from the high-temperature and high-pressure refrigerant in the discharge chamber 40 to the wall of the housing 33 as in the improved swash plate type variable capacity compressor 3 shown in FIGS. In order to prevent the transmission of the heat, the heat insulating material 63 is applied to the entire inner surface of the wall of the housing 33 forming the discharge chamber 40 or the heat insulating material 63 is attached. Further, in order to prevent heat from being transferred from the wall of the housing 33 to the low-temperature and low-pressure refrigerant in the suction chamber 38, the heat insulating material 64 is applied to the entire inner surface of the suction chamber 38 or the heat insulating material 64 is attached. There are cases where a method is taken.

  However, when the inner surface of the discharge chamber 40 or the suction chamber 38 is completely covered with the heat insulating material 63 or 64 as in the conventional improved swash plate type variable capacity compressor 3, the discharge refrigerant in the discharge chamber 40 is removed. Although the amount of heat transmitted to the housing 33 through the wall surface of the discharge chamber 40 is reduced and the amount of heat absorbed by the suction refrigerant passing through the suction chamber 38 is also reduced, heat is not released from the discharge refrigerant in the discharge chamber 40. As a result, the temperature of the discharged refrigerant itself (discharge temperature) is maintained at a high level, so that the high-temperature and high-pressure refrigerant flows into the condenser or gas cooler as it is, thereby reducing the cycle efficiency of the entire refrigeration cycle. Become.

  In order to solve the problems found in the conventional compressors 2 and 3 and the like at the same time, in the swash plate type variable capacity compressor 1 as the first embodiment of the present invention shown in FIGS. 1 and 2, Of the wall surrounding the discharge chamber 40, the portion 10 which is a partition wall between the discharge chamber 40 and the outside air (atmosphere) is not provided with a heat insulating material, and an annular shape between the discharge chamber 40 and the suction chamber 38 is provided. By providing the heat insulating material 11 only on the inner surface of the partition wall 37, the heat of the discharged refrigerant is dissipated from the discharge chamber 40 into the outside air, and the heat of the discharged refrigerant in the discharge chamber 40 passes through the partition wall 37. Transmission to the low-temperature suction refrigerant in the suction chamber 38 is prevented. Further, in the compressor 1 of the first embodiment, a heat insulating material 64 is also provided on the inner surface of the suction chamber 38, and the heat of the discharged refrigerant transmitted to the wall of the rear housing 33 is absorbed by the refrigerant in the suction chamber 38. Is also blocked.

  Thus, in the compressor 1 of 1st Example, since the heat insulating material 11 is not provided in the part 10 used as the partition between external walls among the wall surfaces of the discharge chamber 40, it is the inside of the discharge chamber 40. The heat of the high-temperature and high-pressure refrigerant is transmitted to the rear housing 33 in the part 10 of the partition wall, and is radiated from the surface of the rear housing 33 to the outside air as indicated by a thin arrow a. Thereby, since the temperature of the discharged refrigerant is lowered, it is possible to prevent the cycle efficiency in the refrigeration cycle from being lowered. Although the temperature of the rear housing 33 and the like is slightly increased by providing the partial heat insulating material 11, the heat is prevented from being transmitted to the suction refrigerant by the heat insulating material 64 provided on the inner surface of the suction chamber 38. An increase in the temperature of the refrigerant is prevented, and the problem of a decrease in efficiency of the compressor 1 due to so-called “heating loss” does not occur.

  In this case, as the heat insulating means such as the partial heat insulating material 11 used in the discharge chamber 40 and the heat insulating material 64 used in the suction chamber 38, for example, fine particles of inorganic material such as ceramics containing many bubbles are used. An arbitrary method such as a method of applying a heat insulating paint mixed with a heat insulating material, a solid resin material foam-molded in advance, or directly molding the heat insulating material on the wall surface can be employed.

  In the compressor 1 of the first embodiment, the suction chamber 38 is provided on the outer side (outer peripheral portion) of the rear housing 33 and the discharge chamber 40 is provided on the inner side (center portion) of the rear housing 33. A swash plate type variable displacement compressor 4 according to the second embodiment of the present invention shown in FIGS. 7 and 8 is obtained by reversing the internal and external positional relationship between the chamber 38 and the discharge chamber 40. In the compressor 4, a suction chamber 66 is provided at the center of the rear housing 65, and an annular discharge chamber 67 is provided at the outer periphery thereof. An annular partition wall 68 is formed between the chambers. The positions of the suction port 39 and the discharge port 41 of the valve plate 34 are changed in accordance with the positions of the suction chamber 66 and the discharge chamber 67. Further, the valve presser 69 for the discharge valve provided in the discharge port 41 is not star-shaped but corresponds to each discharge port 41.

  In the swash plate type variable capacity compressor 4 of the second embodiment, as shown in FIG. 7, the discharge refrigerant in the discharge chamber 67 and the outside air out of the wall surface surrounding the discharge chamber 67 in the outer peripheral portion of the rear housing 65. A partial heat insulating material 13 is provided on the inner surface of the discharge chamber 67 except for the portion 12 serving as a partition wall. A heat insulating material 14 is provided on the entire inner surface of the suction chamber 66. The materials and application methods of the heat insulating materials 13 and 14 are the same as those in the first embodiment. Since the swash plate type variable displacement compressor 4 of the second embodiment has such a configuration, even if the positional relationship between the suction chamber and the discharge chamber changes, the operation is substantially the same as that of the compressor 1 of the first embodiment. There is an effect.

The present invention can be most suitably applied to a refrigerant compressor used in an air conditioner. In this case, the refrigerant to be compressed may be a so-called supercritical pressure fluid such as CO ₂ . Furthermore, the present invention can be applied to a compressor of a general fluid such as air, in which case the efficiency of the compressor can be improved by at least reducing heat loss. The type of the compression mechanism is not limited to the swash plate type, and the present invention can be applied to various types of compressors such as a piston type, a scroll type, a vane type, and a centrifugal type.

It is a vertical front view of the compressor of 1st Example. It is a cross-sectional side view of the compressor of 1st Example. It is a vertical front view of the compressor as a prior art example. It is a cross-sectional side view of the compressor as a prior art example. It is a vertical front view of the compressor as an improved conventional example. It is a cross-sectional side view of the compressor as an improved conventional example. It is a vertical front view of the compressor of 2nd Example. It is a cross-sectional side view of the compressor of 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Swash plate type variable capacity compressor 2 of 1st Example ... Conventional swash plate type variable capacity compressor 3 ... Improved conventional swash plate type variable capacity compressor 4 ... Swash plate type variable of 2nd Example Capacity compressor 10 ... Part 11 serving as a partition wall with outside air ... Partial heat insulating material 12 ... Part 13 serving as a partition wall between outside air ... Partial heat insulating material 14 ... Overall heat insulating material 33 ... Rear housing 34 ... Valve plate 37 ... Annular partition wall 38 ... Suction chamber 40 ... Discharge chamber 63, 64 ... Insulating material 65 ... Rear housing 66 ... Suction chamber 67 ... Discharge chamber 68 ... Annular partition wall

Claims (7)

  In the compressor comprising: a suction chamber into which a fluid to be compressed is introduced; a compression mechanism that sucks and compresses the fluid in the suction chamber; and a discharge chamber into which the compressed fluid is discharged. And the discharge chamber are adjacent to each other, and a heat insulating material is provided on at least the inner surface of the discharge chamber side of a portion of the wall surrounding the discharge chamber that becomes a partition wall with the suction chamber. And a heat insulating material is not provided on the inner surface of the discharge chamber side and the outer surface of at least a part of the wall where the outer surface is in contact with the outside air.   2. The compressor according to claim 1, further comprising a heat insulating material provided on an inner surface of the wall surrounding the suction chamber on the suction chamber side.   3. The compressor according to claim 1, wherein the compressor is a piston type. The compressor according to any one of claims 1 to 3, wherein the fluid to be compressed is a CO ₂ refrigerant.   5. The compressor according to claim 1, wherein a heat insulating paint is applied to a wall surface of the discharge chamber or the suction chamber as at least a part of the heat insulating material.   5. The compressor according to claim 1, wherein a solid heat insulating material is press-fitted into the discharge chamber or the suction chamber as at least a part of the heat insulating material.   The compressor according to any one of claims 1 to 4, wherein a heat insulating material is molded on a wall surface of the discharge chamber or the suction chamber as at least a part of the heat insulating material.

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