JP2005146958A - Hermetic compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hermetic compressor capable of highly efficiently suppressing and compressing heat transfer inside a discharge chamber from a high-temperature fluid to an intake fluid. <P>SOLUTION: This hermetic compressor is provided with a compression mechanism part 200 inside a casing 101 for compressing the taken-in liquid, discharging it to the discharge chamber 257 and then making it flow out outside the casing 101. The discharge chamber 257 is formed of a member 260 different from a member forming the casing 101. Working pressure of at least the periphery of the discharge chamber 257 is made to be the same as that of the taken-in fluid. The discharge chamber 257 is provided with a thermal insulation means 290 for suppressing transfer of heat of the liquid compressed by the compression mechanism 200 to the taken-in fluid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a hermetic compressor suitable for application to, for example, a supercritical refrigeration cycle using CO ₂ as a refrigerant.

  As a conventional compressor, for example, as disclosed in Patent Document 1, a movable scroll member is engaged with a fixed scroll member, and after compressing the refrigerant gas in a compression chamber formed between the two roll members, the compressed refrigerant gas is used. In a compressor that discharges to a discharge chamber formed by a substrate of a fixed scroll member and a housing (casing) (that is, a scroll type compressor), a heat insulating film made of a low thermal conductivity material is provided on the back surface of the discharge chamber side of the substrate. Things are known.

Thereby, it is possible to reduce the thermal effect of the compressed refrigerant gas discharged into the discharge chamber on the fixed scroll member and the refrigerant gas on the compression chamber side, and suppress thermal deformation in the axial direction and the radial direction of the fixed scroll member, In addition, the refrigerant gas flowing into the compression chamber is suppressed from being heated, and the volumetric efficiency during compression is improved.
Japanese Utility Model Publication No.59-111982

  However, with the aim of reducing weight and cost, a low pressure dome type compressor (sealed compression) in which a discharge chamber is formed by a member different from the housing and the inside of the housing (around the discharge chamber) is in a low pressure atmosphere by the sucked refrigerant gas The intake refrigerant gas is affected (heated) from the compressed high-temperature refrigerant gas in the discharge chamber, which leads to a decrease in volumetric efficiency during compression. was there.

  In view of the above problems, an object of the present invention is to provide a hermetic compressor that enables high-efficiency compression by suppressing heat transfer from a high-temperature fluid in a discharge chamber to an intake fluid.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the invention, in the hermetic compressor, the compression provided in the casing (101), compresses the sucked fluid and discharges it to the discharge chamber (257), and then flows out of the casing (101). The discharge chamber (257) having a mechanism (200) is formed from a member (260) different from the member forming the casing (101), and at least the operation around the discharge chamber (257) is sucked. The discharge chamber (257) is provided with heat insulating means (290) that suppresses the heat of the fluid compressed by the compression mechanism (200) from being transferred to the sucked fluid. It is a feature.

  Thereby, since the temperature rise of the sucked fluid is suppressed, the reduction in volumetric efficiency at the time of compression due to the decrease in fluid density is suppressed, and highly efficient compression becomes possible.

  The invention according to claim 2 is characterized in that the heat insulating means (290) is provided on the inner wall surface of the discharge chamber (257).

  Thereby, since the heat from the compressed fluid in the discharge chamber (257) can be directly insulated, the effect of suppressing the temperature rise with respect to the sucked fluid can be enhanced.

  As in the third aspect of the present invention, the heat insulating means (290) may be provided on the outer wall surface of the discharge chamber (257).

  Thereby, since the heat insulation means (290) is provided in the environment on the low temperature and low pressure side of the fluid, the material selection of the heat insulation means (290) can be facilitated and made inexpensive.

  As in the invention described in claim 4, the heat insulating means (290) can be formed as a heat insulating material (290) in close contact with the inner wall surface or the outer wall surface of the discharge chamber (257).

  Further, as in the invention described in claim 5, the heat insulating means (290) is a heat insulating material (291) made of a resin member, and is mechanically fixed to the inner wall surface or the outer wall surface of the discharge chamber (257). Anyway.

  Further, as in the invention described in claim 6, the compression mechanism section (200) further compresses the fluid compressed to the intermediate pressure and the first compression mechanism section that compresses the sucked fluid to the intermediate pressure. A second compression mechanism that discharges into the discharge chamber (257), and at least around the discharge chamber (257) is an intermediate pressure instead of the working pressure of the sucked fluid. Application is also possible.

  In the invention according to claim 7, the compression mechanism section (200) has a working chamber formed between the orbiting scroll (240) and the fixed scroll (250) facing the orbiting scroll (240). (256) is a scroll type compression mechanism (200) for compressing fluid.

  Thereby, it can be set as the compact compressor of high efficiency and low noise (100).

  In the inventions according to claims 1 to 7, as in the invention according to claim 8, an electric motor part (300) driven by external power is provided in the casing (101) to compress the casing. The mechanism part (200) may be operated by the electric motor part (300).

  Thereby, the operation of the compression mechanism part (200) based on the control can be easily performed, and the motor part (300) is cooled by the low-temperature refrigerant sucked, so that a highly reliable hermetic compressor (100).

  Furthermore, in the invention described in claims 1 to 8, as in the invention described in claim 9, the fluid is a refrigerant that circulates in the refrigeration cycle, and the pressure after the compression of the refrigerant is a critical pressure. It is suitable for use in those set to exceed.

  That is, when the refrigerant is used at such a high pressure that the pressure after compression exceeds the critical point, the temperature of the refrigerant also becomes high, and the refrigerant sucked is easily affected by the temperature rise. Can be used effectively.

The specific refrigerant in the invention described in claim 9 is a case of CO ₂ as in the invention described in claim 10.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

(First embodiment)
A first embodiment of the present invention is shown in FIG. 1, and a specific configuration will be described first. The hermetic compressor 100 of this embodiment is applied to a supercritical refrigeration cycle in which the pressure after compression exceeds the critical pressure using CO ₂ as a refrigerant.

  As shown in FIG. 1, a hermetic compressor (hereinafter referred to as a compressor) 100 includes a scroll-type compression mechanism unit 200 integrally provided with an electric motor unit 300, and the electric motor unit 300 causes the compression mechanism unit 200 to be integrated. The electric compressor is operated. The compression mechanism unit 200 and the electric motor unit 300 are accommodated in a pressure vessel (corresponding to the casing of the present invention) 101 including a main body casing 101a, an upper casing 101b, and a lower casing 101c.

  The electric motor unit 300 includes a rotor 310 fixed to the shaft 211 and a stator 320 that is shrink-fitted and fixed to the inner wall of the main body casing 101a on the outer peripheral side of the rotor 310. When electric power is supplied to the motor unit 300 from an external power source (battery) (not shown), the rotor 310 is driven to rotate and the shaft 211 is rotated.

  The compression mechanism section 200 is formed of a turning scroll 240 connected to an eccentric crank mechanism 210 formed with the shaft 211 as a main body section, a fixed scroll 250 disposed opposite to the turning scroll 240, and the like.

  The eccentric crank mechanism 210 is formed by a bush 213 assembled to a drive pin 212 formed on one end side (lower side in FIG. 1) of the shaft 211 and a snap ring 214 that prevents the bush 213 from coming off. .

  The shaft 211 has a main receiving portion 211a having a large outer diameter on one end side, and the main receiving portion 211a is integrally provided with a drive pin 212 that is eccentric with respect to the shaft center of the shaft 211. . A main bearing 215 is fixed to the middle housing 220 provided in the main body casing 101a, and a sub-bearing 216 is fixed to the holder 230 having the opening 231. The main receiving portion 211a corresponds to the main bearing 215. Further, the other end side of the shaft 211 corresponds to the auxiliary bearing 216, and the shaft 211 is rotatably supported.

  The bush 213 is a cylindrical member provided with an eccentric hole 213a. The drive pin 212 is rotatably inserted into the eccentric hole 213a, and a snap ring 214 having a C-shape is formed at the tip of the drive pin 212. Is fixed to prevent the bush 213 from coming off. As described above, the bush 213 is mounted in an eccentric manner with respect to the axis of the shaft 211, and revolves around the axis of the shaft 211 when the shaft 211 rotates. The bush 213 is fixed with a balancer 217 for canceling out dynamic imbalance during rotation operation by press fitting, caulking, shrink fitting, welding, or the like.

  A turning scroll 240 is connected to the bush 213 of the eccentric crank mechanism 210. The orbiting scroll 240 is provided with a spiral blade portion 242 and a cylindrical boss portion 243 on each plane (upper and lower surfaces in FIG. 1) of the disc-shaped end plate portion 241. The orbiting scroll bearing 245 is press-fitted into. The bush 213 is inserted into the boss portion 243 via the orbiting scroll bearing 245. The orbiting scroll 240 is supported by a thrust bearing 246 fixed to the middle housing 220 so as to be able to perform a revolving operation via the bush 213. The thrust bearing 246 plays a role of receiving a thrust load generated in the orbiting scroll 240 during the compression operation.

  A rotation prevention hole 244 is provided on the outer peripheral side of the end plate portion 241, and a rotation prevention pin 254 provided in the fixed scroll 250 described later is inserted to prevent the rotation of the orbiting scroll 240. .

  A fixed scroll 250 having a spiral blade 252 formed on the end plate portion 251 is provided on the opposite shaft side of the orbiting scroll 240, and the fixed scroll 250 is fixed to the middle housing 220 with a bolt (not shown). The blade portion 242 of the orbiting scroll 240 and the blade portion 252 of the fixed scroll 250 are fitted in the longitudinal direction of the shaft 211 to form a crescent-shaped working chamber 256.

  A concave portion 255 is provided on the side opposite to the blade portion of the fixed scroll 250, and a discharge hole 253 is further provided in the center portion. On the opening side of the recessed portion 255 of the fixed scroll 250, there is provided a rear plate 260 that is a member different from the members (the casings 101a to 101c) that form the pressure-resistant container 101. It is fixed.

  A concave portion 261 is provided on the fixed scroll 250 side of the rear plate 260, and a discharge chamber 257 serving as an internal space is formed by the concave portions 255 and 261 of the fixed scroll 250 and the rear plate 260. The discharge hole 253 is provided with a discharge valve 270 that opens to the discharge chamber 257 side and a stopper 271 that regulates the maximum opening of the discharge valve 270, and is fixed to the fixed scroll 250 by bolts 272.

  A space 101 is formed between the rear plate 260 fixed to the fixed scroll 250 and the lower casing 101c.

  The middle housing 220 is provided with a refrigerant passage 221 and a suction chamber 222, and the space in which the electric motor unit 300 is mainly accommodated is the suction chamber 222 via the refrigerant passage 221, the outer portion of the boss portion 243, and the thrust bearing 246. To communicate with. Further, the suction chamber 222 and the working chamber 256 communicate with each other by a passage provided in the fixed scroll 250 (not shown).

  In addition, the fixed scroll 250 is provided with a communication hole 258 that penetrates in the thickness direction of the end plate portion 251 so that the suction chamber 222 communicates with the space 101d.

  The upper housing 101b is provided with a suction pipe 281 communicating with the main body casing 101a, and the fixed scroll 250 is provided with a discharge pipe 282 communicating with the discharge chamber 257.

  In the present invention, a heat insulating means is provided on the inner wall surface of the discharge chamber 257. The heat insulating means is a porous heat insulating material 290 such as silicon rubber, for example, and is provided in close contact with the inner wall surface of the recess 261 of the rear plate 260 by coating.

  Next, the operation based on the above configuration and the operation and effect thereof will be described. When electric power is supplied to the electric motor unit 300, the rotor 310 is driven to rotate, the shaft 211 rotates accordingly, and the bush 213 revolves around the shaft 211 with an eccentric amount. Then, the orbiting scroll 240 revolves together with the bush 213, and the refrigerant flows from the suction pipe 281 through the electric motor unit 300, the refrigerant passage 221, and the suction chamber 222 into the working chamber 256 to a high temperature and high pressure (beyond the critical point). The compressed air is further discharged into the discharge chamber 257 through the discharge hole 253 and the discharge valve 270, and flows out from the discharge pipe 282.

  In the compressor 100, the refrigerant sucked from the suction pipe 281 reaches the space 101d from the suction chamber 222 through the communication hole 258, and the pressure vessel 101 becomes a pressure atmosphere of the sucked refrigerant. This is a so-called low-pressure dome type compressor, and the pressure of the compressed refrigerant is received by the fixed scroll 250 and the rear plate 260. The pressure vessel 101 does not need high pressure resistance, and can be light and low in cost. Has the advantage of being able to.

  In the present invention, the heat insulating material 290 can suppress the heat of the high-temperature refrigerant discharged into the discharge chamber 257 from being transmitted to the intake refrigerant in the space 101d via the rear plate 260, so that the temperature of the intake refrigerant increases. , And a reduction in volumetric efficiency at the time of compression due to a decrease in the density of the refrigerant is suppressed, thereby enabling highly efficient compression.

  Since the heat insulating material 290 is provided on the inner wall surface of the discharge chamber 257 (rear plate 260), the heat from the compressed refrigerant in the discharge chamber 257 can be directly insulated, and the suction refrigerant The effect of suppressing the temperature rise can be enhanced.

  Moreover, since the scroll-type compression mechanism part is employ | adopted as the compression mechanism part 200, it can be set as the compressor 100 of small size, high efficiency, and low noise.

  In addition, since the compression mechanism unit 200 is the electric compressor 100 that is operated by the electric motor unit 300 provided in the pressure vessel 101, the compression mechanism unit 200 can be easily operated based on the control, and the suction unit By cooling the motor unit 300 with the low-temperature refrigerant that is generated, the compressor 100 with high reliability can be obtained.

Further, as in the present embodiment, when CO ₂ is used as the refrigerant and the refrigerant is used at a high pressure such that the pressure after compression of the refrigerant exceeds the critical point, the temperature of the refrigerant also increases, and the refrigerant to be sucked in Therefore, the present invention can be effectively used because it is easily affected by the temperature rise.

  Note that the heat insulating material 290 provided in the discharge chamber 257 may also be provided on the inner wall surface of the concave portion 255 of the fixed scroll 250 as shown in FIG. It is possible to insulate the refrigerant in the middle of the compression in the working chamber 256, and it is possible to suppress the lowering of the refrigerant density and to perform more efficient compression.

(Second Embodiment)
A second embodiment of the present invention is shown in FIG. In the second embodiment, in contrast to the first embodiment, the heat insulating material 291 is made of a resin material, and is provided on the outer wall surface of the rear plate 260.

  The heat insulating material 291 is formed in advance along the outer wall surface of the rear plate 260, and after being fitted to the rear plate 260, the heat insulating material 291 is mechanically fixed by an engaging claw or screw tightening (not shown). ing.

  Thereby, since the heat insulating material 291 is provided in the environment on the low temperature and low pressure side of the suction refrigerant, the material selection of the heat insulating material 291 can be facilitated and made inexpensive.

(Other embodiments)
In the first and second embodiments, the description has been given assuming that the periphery of the discharge chamber 257 is applied to the compressor 100 that is placed in the pressure atmosphere of the suction refrigerant. However, the compression mechanism 200 is installed in the cylinder as is well known, for example. A rotary type first compression mechanism portion and a second compression mechanism portion, each of which includes a rotor and a vane, are arranged, and the sucked refrigerant is compressed to an intermediate pressure by the first compression mechanism portion. The intermediate pressure dome type compressor in which the refrigerant compressed to the pressure is further compressed by the second compression mechanism and discharged to the discharge chamber (257) so that the pressure around the discharge chamber (257) becomes an intermediate pressure. It may be applied to.

  If the discharge chamber (257) of this compressor is provided with the same heat insulating material (290) as in the first and second embodiments so that the heat of the compressed refrigerant is not transferred to the intermediate pressure refrigerant, 2 The compression efficiency can be increased by suppressing the density reduction of the refrigerant in the compression mechanism.

  In the first and second embodiments, the compression mechanism 200 is not limited to the scroll type, and may be a compression mechanism such as a piston type or a vane type.

  The compressor 100 has been described as an electric compressor in which the compression mechanism unit 200 is operated by the electric motor unit 300. However, the compressor 100 may be operated by an external prime mover such as an internal combustion engine (engine) mounted on a vehicle. good.

Furthermore, although described as applied to a supercritical refrigeration cycle using CO ₂ as refrigerant, may be applied to a normal refrigeration cycle using Freon is not limited thereto.

It is sectional drawing which shows the whole structure of the hermetic compressor which shows 1st Embodiment of this invention. It is sectional drawing which shows the discharge chamber vicinity in the modification of 1st Embodiment. It is sectional drawing which shows the discharge chamber vicinity in 2nd Embodiment.

Explanation of symbols

100 hermetic compressor 101 pressure vessel (casing)
200 Scroll type compression mechanism (compression mechanism)
240 orbiting scroll 250 fixed scroll 256 working chamber 257 discharge chamber 260 rear plate (another member)
290, 291 Heat insulation material (heat insulation means)
300 Electric motor part

Claims (10)

A compression mechanism (200) that is provided in the casing (101), compresses the sucked fluid and discharges it into the discharge chamber (257), and then flows out of the casing (101);
The discharge chamber (257) is formed of a member (260) different from the member forming the casing (101),
At least around the discharge chamber (257) is the operating pressure of the sucked fluid;
The discharge chamber (257) is provided with heat insulating means (290) for suppressing the heat of the fluid compressed by the compression mechanism (200) from being transmitted to the sucked fluid. Hermetic compressor.   The hermetic compressor according to claim 1, wherein the heat insulating means (290) is provided on an inner wall surface of the discharge chamber (257).   The hermetic compressor according to claim 1, wherein the heat insulating means (290) is provided on an outer wall surface of the discharge chamber (257).   The said heat insulation means (290) is the heat insulating material (290) closely_contact | adhered to the inner wall surface or the outer wall surface of the said discharge chamber (257), The sealing in any one of Claims 1-3 characterized by the above-mentioned. Mold compressor.   The heat insulating means (290) is a heat insulating material (291) made of a resin member, and is mechanically fixed to the inner wall surface or the outer wall surface of the discharge chamber (257). The hermetic compressor according to any one of 3 above. The compression mechanism (200) is a first compression mechanism that compresses the sucked fluid to an intermediate pressure, and a second compression mechanism that compresses the fluid compressed to the intermediate pressure and discharges it to the discharge chamber (257). Consisting of a compression mechanism,
The hermetic compressor according to any one of claims 1 to 5, wherein at least the periphery of the discharge chamber (257) becomes the intermediate pressure instead of the working pressure of the sucked fluid.   The compression mechanism (200) compresses the fluid in a working chamber (256) formed between the orbiting scroll (240) and a fixed scroll (250) opposed to the orbiting scroll (240). The hermetic compressor according to any one of claims 1 to 6, wherein the compressor is a scroll-type compression mechanism (200). An electric motor part (300) provided in the casing (101) and driven by receiving external electric power;
The hermetic compressor according to any one of claims 1 to 7, wherein the compression mechanism (200) is operated by the electric motor (300). The fluid is a refrigerant that circulates in the refrigeration cycle,
The hermetic compressor according to any one of claims 1 to 8, wherein a pressure after compression of the refrigerant is set to exceed a critical pressure. The hermetic compressor according to claim 9, wherein CO ₂ is used as the refrigerant.

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