JP6132567B2 - Scroll compressor - Google Patents

Description

  The present invention relates to a scroll compressor used in a refrigeration apparatus (including a refrigerator and an air conditioner) using R32 as a refrigerant.

  Conventionally, scroll compressors for refrigeration and air conditioning are fixed in a sealed container at a compression mechanism unit including a fixed scroll and a turning scroll, a frame, an electric motor including a rotor and a stator, and the center of the rotor. A rotating shaft that rotates in rotation, a rolling bearing that is provided on the frame and supports the rotating shaft, and an Oldham coupling that is engaged with the frame and the orbiting scroll to rotate the orbiting scroll without rotating. ing. And this scroll compressor uses R410A etc. which are kind to a global environment as a refrigerant | coolant compressed by the said compression mechanism part.

When R410A is used as the refrigerant, the maximum discharge temperature is about 120 ° C., and a neodymium magnet is generally used for the rotor of the electric motor.
Examples of this type of prior art include those described in Patent Document 1 (Japanese Patent Laid-Open No. 2008-82272) and Patent Document 2 (Japanese Patent Laid-Open No. 2012-55117).

JP 2008-82272 A JP 2012-55117 A

  In the compressor using R410A as the refrigerant, the discharge temperature rises to about 120 ° C., so that each component can withstand about 120 ° C. Therefore, the insulation class of the stator insulation of the motor is JISC4003: heat resistance class 120 (E) (hereinafter referred to as heat resistance class 120 (E)) stipulated in the electrical insulation, and the Oldham joint is made of aluminum. As the bearing, a bearing having a heat resistant temperature of about 120 ° C. is used.

  However, recently, adoption of refrigerants such as R32 having a low global warming potential (GWP) has been studied. When R32 refrigerant is used as the refrigerant of the compressor, the compressor discharge gas temperature becomes higher by about 20 ° C. to 30 ° C. than refrigerants such as R22 and R410A. When the discharge temperature increases, the ambient temperature of the electric motor in the hermetic container rises, and there is a problem that the heat resistance temperature of the stator insulating material is exceeded and coil burning occurs.

  Further, when a neodymium magnet is used for the rotor of the electric motor, irreversible demagnetization is likely to occur because the ambient temperature of the electric motor exceeds the demagnetization heat resistance temperature of the neodymium magnet. When irreversible demagnetization occurs, there arises a problem in that the efficiency decreases due to an increase in the electric current of the motor winding and the temperature rises further.

  Further, in the scroll compressor, the Oldham joint for preventing the rotation of the frame and the orbiting scroll is at a high temperature about the discharge gas temperature during the operation of the compressor. Therefore, when the R32 refrigerant is used, the discharge gas temperature is higher by about 20 ° C. to 30 ° C. than the R22 or R410A refrigerant. That is, the temperature of the Oldham joint and the frame is about 120 + 20-30 ° C. = 140 ° C.-150 ° C.

  On the other hand, in a scroll compressor that uses aluminum as the material for the Oldham joint and uses a casting for the frame, the key gap formed by the key of the Oldham joint and the key groove formed in the frame has its linear expansion. Due to the difference in coefficient, the gap during operation becomes smaller than when the compressor is stopped. Even in the structure in which the gap is secured in the R410A refrigerant, it is assumed that the gap cannot be secured by using the R32 refrigerant. In this case, the sliding portion between the key of the Oldham joint and the key groove of the frame is worn. There is also a problem that galling occurs, which causes vibration and noise of the compressor, and in the worst case, the compressor stops, reducing the reliability of the scroll compressor.

  An object of the present invention is to obtain a scroll compressor that can ensure reliability even when an R32 refrigerant is used.

In order to achieve the above object, the present invention provides a compression mechanism portion having a fixed scroll and a turning scroll, a frame that supports the compression mechanism portion, an electric motor that drives the compression mechanism portion via a rotating shaft, and the rotation A rolling bearing as a main bearing that supports the main shaft portion of the shaft , a rolling bearing as a sub bearing that supports the sub-bearing support portion of the rotating shaft, a key groove formed in the frame, and the orbiting scroll. A scroll compressor for a refrigeration apparatus comprising a key that engages with a key groove, and an Oldham coupling for making a turning motion while preventing the orbiting scroll from rotating, and a sealed container that houses each of the components. the use of R32 alone refrigerant as a refrigerant for a refrigeration apparatus, the temperature rise of the frame key of the Oldham coupling [Delta] T, the key grooves formed in the frame When the width is L1, the linear expansion coefficient of the frame is α1, the width of the key formed on the Oldham joint is L2, and the linear expansion coefficient of the Oldham joint is α2, the keyway width L1 of the frame and the Oldham joint The relationship with the key width L2 is that ΔT = 130 ° C.
L1 (1 + α1 · ΔT)> L2 (1 + α2 · ΔT)
It is characterized by being satisfied.

  According to the present invention, even when an R32 refrigerant is used, an effect of obtaining a scroll compressor that can ensure reliability can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a first embodiment of a scroll compressor according to the present invention. II-II sectional view taken on the line of the electric motor shown in FIG. It is a figure which expands and shows the Oldham coupling shown in FIG. 1, (a) is a side view, (b) is a bottom view. The top view which expands and shows the flame | frame shown in FIG.

  Hereinafter, specific embodiments of the scroll compressor of the present invention will be described with reference to the drawings.

A scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the scroll compressor of this embodiment will be described with reference to FIG.
The scroll compressor 1 is a scroll compressor for a refrigeration apparatus used in a refrigeration apparatus such as a refrigerator or an air conditioner, and includes a compression mechanism unit 2 that compresses a refrigerant gas that is a working fluid and discharges the refrigerant gas upward. The driving mechanism 3 that drives the compression mechanism 2 via the rotary shaft 300 is housed in a cylindrical sealed container 700. In the present embodiment, the vertical scroll compression in which the compression mechanism unit 2, the drive unit 3, and the oil sump 730 are arranged in this order from the top, and the compression mechanism unit 2 and the drive unit 3 are connected via the rotation shaft 300. Machine.

  The sealed container 700 has an upper cap 710 and a lower cap 720. The upper cap 710 and the lower cap 720 are fitted over the central cylindrical portion of the sealed container 700 so as to cover the outside, and the fitting end portions are heated and welded obliquely from below and obliquely upward by a welding torch. A leg portion 721 is attached to the bottom surface of the sealed container 700. A magnet 722 is attached to the inside of the lower cap 720 and plays a role of collecting dust (iron powder or the like) in the compressor.

  A hermetic terminal 702 and a terminal cover 703 are provided on the side surface of the hermetic container 700 so that electric power can be supplied to the electric motor 600. The hermetic terminal 702 is provided through the hermetic container 700 and is positioned between the coil end 601 a of the stator 601 and the frame 400.

The compression mechanism unit 2 is configured with a fixed scroll 100 and a turning scroll 200 as basic elements.
The driving unit 3 that drives the orbiting scroll 200 to rotate is an Oldham that is a main part of the rotation prevention mechanism of the electric motor 600 including the stator 601 and the rotor 602, the rotating shaft 300, the oil supply pump 900, and the orbiting scroll 200. The joint 500 includes rolling bearings 401 and 803, an orbiting scroll bearing portion 203, and a sliding bearing 210 disposed on the orbiting scroll bearing portion 203.

  The rotating shaft 300 includes a main shaft portion 302, a crankpin 301, and a sub bearing support portion 303 that are integrally provided. The main shaft portion 302 and the sub-bearing support portion 303 are formed on the same axis, and constitute a portion of the main shaft portion 302. Further, an oil supply pump 900 is press-fitted into the lower end portion of the rotary shaft 300. The rolling bearings 401 and 803 constitute a rotating shaft support portion that rotatably engages the main shaft portion 302 and the sub bearing support portion 303 of the rotating shaft 300. The orbiting scroll bearing portion 203 is provided in the orbiting scroll 200 so that the sliding bearing 210 is press-fitted into the inner diameter of the orbiting scroll bearing portion 203 so that the crank pin 301 of the rotating shaft 300 can be moved and rotated in the thrust direction that is the rotating shaft direction. It has been.

  The rolling bearing (main bearing) 401 is arranged on the upper side of the electric motor 600, and the rolling bearing (sub bearing) 803 is arranged on the lower side of the electric motor 600. Rolling bearings 401 and 803 constitute main shaft bearings that support main shaft portions on both sides of electric motor 600. A housing 802 is fixed to the lower frame 801 fixed to the hermetic container 700 via bolts 805. A rolling bearing 803 is inserted into the housing 802 from above, and a housing cover 804 is further attached from above.

  The oil pump 900 is a centrifugal pump attached to the lower end of the rotary shaft 300, and forcibly sucks the lubricating oil stored in the oil reservoir 730 through the oil supply hole 901, passes through the oil passage 311, the auxiliary bearing 803, It is provided for supplying to the orbiting scroll bearing 203 and further to the rolling bearing 401. The oil supplied from the oil passage 311 is also supplied to the sliding portion between the orbiting scroll 200 and the fixed scroll 100. The oil passage 311 is provided so as to vertically penetrate the rotating shaft 300, and has a lower oiling hole concentric with the axis of the rotating shaft 300 and an upper oiling hole eccentric with respect to the axis of the rotating shaft 300. doing. A lateral oil supply hole 312 communicating with the lower oil supply hole is provided to supply oil to the auxiliary bearing 803.

  The frame 400 is fixed to the hermetic container 700 and constitutes a member that supports the rolling bearing 401. The frame 400 includes a bearing support portion 401a that supports the rolling bearing 401, and a compression mechanism support portion 401b that extends outward from an upper portion of the bearing support portion 401a and supports the compression mechanism portion 2. The entire lower surface of the compression mechanism support 401b is formed flat and positioned above the discharge pipe 701, and the outer peripheral surface thereof is welded 740 to the inner peripheral surface of the sealed container 700 at a plurality of locations in the circumferential direction.

  A balance weight 407 is provided on the rotating shaft 300 so as to be positioned closer to the motor than the rolling bearing 401. In this embodiment, the balance weight 407 is formed separately from the rotary shaft 300 and is press-fitted and fixed to the rotary shaft 300. However, the balance weight 407 is formed integrally with the rotary shaft 300. It may be provided. A maximum outer diameter portion 407a of the balance weight 407 is provided so as to protrude from the end face side of the coil end 601a of the stator 601 and is larger in diameter than the inner diameter of the coil end 601a. Thereby, a sufficient rotation balance of the rotation shaft 300 can be ensured.

  The fixed scroll 100 includes a base plate 101, a scroll wrap 102 that is a spiral body, a suction port 103, and a discharge port 104, and is fixed to the frame 400 by a plurality of bolts 405. The plurality of bolts 405 are equally arranged in the circumferential direction. The scroll wrap 102 is erected vertically below the base plate 101.

  The orbiting scroll 200 includes a base plate 201, a scroll wrap 202, an orbiting scroll bearing portion 203, a slide bearing 210 disposed in the orbiting scroll bearing portion 203, and a back pressure hole (not shown) as basic components. Yes. The scroll wrap 202 is erected vertically above the base plate 201. The orbiting scroll bearing portion 203 is formed so as to protrude perpendicularly to the lower side (non-lap side) of the base plate 201. The orbiting scroll 200 is formed by processing each component from a casting made of cast iron or aluminum (aluminum).

  The base plate 201 of the orbiting scroll 200 is provided with a back pressure hole (not shown) that allows the compression chamber 130 and the back pressure chamber 411 on the orbiting back surface to communicate with each other. The pressure is maintained at an intermediate pressure (intermediate pressure). The back pressure chamber 411 configured on the back side of the orbiting scroll 200 is a space formed by being surrounded by the orbiting scroll 200, the frame 400, and the fixed scroll 100. Therefore, the frame 400 also serves as a member that forms the back pressure chamber 411.

  A seal ring 410 is provided in a groove formed on the upper surface of the frame 400, and the seal ring 410 prevents discharge gas from flowing into the back pressure chamber 411. The orbiting scroll 200 is pressed against the fixed scroll 100 by the resultant force of the intermediate pressure in the back pressure chamber 411 and the discharge pressure acting inside the seal ring 410. The inner diameter of the seal ring 410 is smaller than the outer diameter of the rolling bearing 401.

  In order to be able to adopt such a configuration, the rolling bearing 401 is inserted into the frame 400 from the rotation driving means side of the frame 400, and the inserted rolling bearing 401 is fixed by the frame cover 403. Yes. A thrust bearing 402 is provided on the frame cover 403. The frame cover 403 is formed separately from the frame 400.

  The frame cover 403 is fixed to the frame 400 with bolts 406. By fixing the bolts in this manner, the gap between the frame cover 403 and the frame 400 can be accurately sealed, so that oil leakage from the oil supply path can be suppressed. The frame cover 403 includes a portion that is inserted inside the frame 400 and presses the rolling bearing 401, and a portion that contacts and is fixed to the end surface of the frame 400 on the side of the rotation driving means.

  An Oldham joint 500 is disposed on the back surface of the base plate 201 of the orbiting scroll 200. The Oldham joint 500 is formed with two sets of orthogonal keys (see 614 shown in FIG. 3), and one set of these keys is a key groove that is a receiving portion of the Oldham joint 500 formed on the frame 400. (See 399 in FIG. 4), and the remaining one set slides on the key groove 206 formed on the back side of the base plate 201 of the orbiting scroll wrap 202. As a result, the orbiting scroll 200 orbits within the plane perpendicular to the axial direction, which is the direction in which the scroll wrap 202 stands, without rotating with respect to the fixed scroll 100.

  When the crank pin 301 rotates eccentrically due to the rotation of the rotary shaft 300 connected to the electric motor 600, the compression mechanism unit 2 performs the orbiting motion without causing the orbiting scroll 200 to rotate with respect to the fixed scroll 100 by the Oldham coupling 500. The gas is sucked into the compression chamber 130 formed by the scroll wraps 102 and 202 through the suction pipe 711 and the suction port 103. The compression chamber 130 formed by meshing the fixed scroll 100 and the orbiting scroll 200 is subjected to a compression operation in which the volume thereof is reduced by the orbiting movement of the orbiting scroll 200. That is, due to the orbiting motion of the orbiting scroll 200, the compression chamber 130 decreases in volume while compressing the refrigerant gas while moving to the center.

  In this compression operation, the refrigerant gas is sucked into the compression chamber 130 via the suction pipe 711 and the suction port 103 as the orbiting scroll 200 rotates, and is sealed from the discharge port 104 of the fixed scroll 100 through the compression stroke. It is discharged into the container 700. Thereby, the space in the sealed container 700 is kept at the discharge pressure. As the refrigerant gas to be compressed by the compression mechanism unit 2, a refrigerant such as R32 that is gentle to the global environment and has a low global warming potential (GWP) is used.

  Thereafter, the discharged refrigerant gas circulates around the compression mechanism unit 2 and the electric motor 600 and then is discharged from the discharge pipe 701 to the outside of the scroll compressor 1 of the sealed container 700.

  Next, the oil supply path will be described. When the rotating shaft 300 is rotated, the oil in the oil reservoir 730 is boosted and supplied to the oil passage 311 in the rotating shaft by the oil supply pump 900. Part of the oil sent to the oil passage 311 flows through the side hole 312 to the auxiliary bearing 803 that is a rolling bearing, and then returns to the oil reservoir 730. The oil that reaches the upper portion of the crankpin 301 through the oil passage 311 passes through the slide bearing 210 and further flows into the rolling bearing 401. Most of the oil that has lubricated the rolling bearing 401 passes through the oil drain pipe 408 and returns to the oil sump 730.

  An oil supply pocket 205 is provided on an end surface of the orbiting scroll bearing portion 203 of the orbiting scroll 200, and the orbiting scroll 200 reciprocates between the outer side and the inner side of the seal ring 410 as the orbiting scroll 200 revolves. Part of the oil between 210 and the bearing 401 is conveyed to the back pressure chamber 411. The conveyed oil is supplied to the Oldham coupling 500 and then supplied to the end face 105 of the fixed scroll and the sliding face of the base plate 201 of the orbiting scroll 200.

  The oil conveyed to the back pressure chamber 411 flows into the compression chamber 130 through a back pressure hole (not shown) or through a minute gap on the end plate sliding surface. The oil flowing into the compression chamber 130 is discharged from the discharge port 104 together with the compressed refrigerant gas, is separated from the refrigerant gas in the sealed container 700, and returns to the oil reservoir 730.

Next, the configuration of the electric motor 600 shown in FIG. 1 will be described with reference to FIG. 2 is a cross-sectional view taken along line II-II of the electric motor 600 shown in FIG.
As shown in FIG. 2, the electric motor 600 includes a rotor 602 fixed to a rotating shaft (crankshaft) 300 and the sealed container 700 (see FIG. 2) so as to face the rotor 602 with a gap in the circumferential direction. 1), and a stator 601 fixedly provided. The rotor 602 includes a rotor core 603, six magnet grooves 604 formed in the stator core 603 in parallel with the rotation shaft 300, and permanent magnets 605 mounted in the respective magnet grooves 604. Etc. By mounting these permanent magnets 605, six magnetic poles are formed on the rotor core 603.

  The stator 601 is composed of a stator core 606, a stator winding 21 and the like. The stator core 606 includes nine stator slots 7a formed on the inner diameter side at equal intervals in the circumferential direction, nine tooth portions 7b, and a core back 7c integrally connecting the outer peripheral sides of the tooth portions 7b. Etc. The stator winding 21 is a concentrated winding method wound so as to surround the teeth portion 7b, and includes a three-phase winding.

  In this way, the electric motor 600 is configured as a concentrated pole permanent magnet type electric motor having 6 poles and 9 slots, and this electric motor 600 is configured to be driven by the inverter driving device. The electric motor 600 may employ, for example, the number of poles such as four poles and six slots, the number of slots, and a distributed winding method.

Next, the relationship between the discharge temperature of the compressor and the winding temperature of the stator will be described with reference to Table 1 for each type of refrigerant compressed by the scroll compressor.
Table 1 shows a comparison of the suction temperature, discharge temperature, and stator winding temperature when R410A, R22, and R32 are used as refrigerants in the refrigeration system, with the evaporation temperature and condensation temperature being constant. ing.

  As shown in Table 1, when R32 is used as the refrigerant, the discharge temperature and the winding temperature of the stator are about 30 ° C. higher than when R22 or R410A is used as the refrigerant. Recognize.

  When the discharge temperature increases, as described above, the ambient temperature of the electric motor 600 in the hermetic container 700 rises, and the problem arises that the heat resistance temperature of the insulating material used for the stator 601 is exceeded and coil burning occurs.

  Further, when a neodymium magnet is used as the permanent magnet 605 of the rotor 602 of the electric motor 600, the irreversible demagnetization occurs exceeding the demagnetization heat resistance temperature of the neodymium magnet, causing a decrease in efficiency due to an increase in current and a further increase in temperature. Also occurs.

  Further, when aluminum is used as the material of the Oldham joint 500 and casting is used for the frame 400, the key 614 of the Oldham joint 500 and a key groove 399 (see FIG. 3) formed in the frame 400 are configured. The key gap becomes smaller due to the difference in the coefficient of linear expansion, and the necessary gap cannot be secured, and the sliding portion between the key of the Oldham joint 500 and the key groove of the frame 400 generates wear and galling, which causes the scroll compression. It will reduce the reliability of the machine.

  In addition, when the rolling bearings 401 and 803 that support the rotating shaft 300 are used at a high temperature of 120 ° C. or more, the amount of dimensional change due to thermal expansion increases, the bearing gap becomes inappropriate, and the bearing may be damaged. Arise.

  Therefore, in the present embodiment, in order to ensure the reliability of the scroll compressor even when the temperature in the sealed container 700 rises by using R32 or the like as a refrigerant, the following devices have been devised. Yes.

  First, in the rotor 602 constituting the electric motor 600, the permanent magnet 605 embedded in the magnet groove (magnet insertion groove) 604 is made of a ferrite magnet. Ferrite magnets have the property of being easily irreversibly demagnetized at lower temperatures and less likely to be irreversibly demagnetized at higher temperatures. Therefore, there is no risk of demagnetization even when the temperature is increased by using an R32 refrigerant. Therefore, even with a scroll compressor that uses R32 as the refrigerant, the performance of the compressor can be maintained.

  Insulating materials used for the stator 601 constituting the electric motor 600 generally have a heat resistance class of 120 (E). On the other hand, in this embodiment, the specification of the insulating material is changed to any one of the heat resistance class 130 (B), the heat resistance class 155 (F), and the heat resistance class 180 (H). When the R32 refrigerant was used with respect to the conventional R410A or R22 refrigerant, it was found that the temperature of the stator winding exceeded 120 ° C. as described in Table 1 above. However, by using the above-mentioned specifications for the insulating material, it is possible to prevent exceeding the heat resistance class of the stator winding even at a high temperature condition of 120 ° C. or higher, and to prevent the stator winding from being burned out. Can do.

  In the present embodiment, the rolling bearings 401 and 803 further use bearing steel subjected to dimensional stabilization processing (TS processing). The bearing steel subjected to the dimensional stabilization treatment is a bearing steel in which a dimensional change under high temperature use is suppressed by high-temperature tempering to stabilize the structure.

  As a result, by adopting a rolling bearing that uses bearing steel that has undergone dimensional stabilization treatment, it is possible to prevent damage to the rolling bearing even when the temperature becomes high due to the use of the R32 refrigerant.

  That is, it was found that when the rolling bearing supporting the rotating shaft is used at a high temperature of 120 ° C. or higher, the dimensional change due to thermal expansion increases (NSK) (NSK) rolling bearing catalog CAT. No. 1102n (Refer to A. Page 5.2.4 and NTN Rolling Bearings General Catalog CAT. No. 2202 / J A-16, page 3.3.2). When this amount of dimensional change is increased, it has been found that the bearing gap becomes inappropriate and may cause damage to the bearing. In this embodiment, as described above, the rolling bearing 401 is used to solve this problem. , 803, bearing steel subjected to dimension stabilization treatment (TS treatment) is employed.

  Further, in this embodiment, in addition to the above measures, the Oldham joint 500 is also configured as follows. This will be described with reference to FIGS. 3 is an enlarged view of the Oldham coupling shown in FIG. 1, (a) is a side view, (b) is a bottom view, and FIG. 4 is an enlarged plan view showing the frame shown in FIG.

  First, an iron-based sintered material is used as the material of the Oldham coupling 500 of the present embodiment. The Oldham coupling 500 is engaged with a key 614 that engages with a key groove 399 formed on the frame 400 and a key groove 206 (see FIG. 1) formed on the back surface of the base plate 201 of the orbiting scroll 200. Keys 614 are formed, and these keys 614 serve as sliding portions with the respective key grooves 206 and 399. If a gap is not secured between the key 614 and the key groove 399 formed in the frame 400 and the key groove 206 formed in the orbiting scroll 200, there is a possibility that wear or galling due to sliding may occur. Therefore, in this embodiment, the effect of deformation (elongation) is minimized by using an iron-based sintered material that has a smaller thermal expansion than aluminum.

  Note that cast iron is generally used as the material of the frame 400 that engages with the key 614 of the Oldham joint 500, and the material of the orbiting scroll 200 is generally composed of an iron-based material such as cast iron.

When an aluminum material is used as the material of the Oldham joint 500, the gap between the Oldham key and the key groove of the frame or the orbiting scroll is 100 at a room temperature of 20 ° C., and the gap when thermally expanded to 120 ° C. is 10. As an example, the gap when thermally expanded to 150 ° C is
10− (150 ° C.−120 ° C.) × (100−10) / (120−20) = − 17
Thus, the gap is not secured. For this reason, galling or wear occurs between the Oldham key and the keyway of the frame or the orbiting scroll.

On the other hand, when an iron-based sintered material is used as the material of the Oldham joint 500, the linear expansion coefficient of iron is “12.1 × 10E-6 / K”, and the linear expansion coefficient of aluminum is “23 × 10E-6”. / K ", when the room temperature changes from 20 ° C to 120 ° C,
100− (100−10) × 12.1 × 10E-6 / 23 × 10E−6 = 53
It becomes. If it changes to 150 ° C,
53− (150 ° C.−120 ° C.) × (100−53) / (120−20) = 39
Thus, a sufficient gap can be secured.

  Therefore, even when the R32 refrigerant is used, by using an iron-based sintered material for the Oldham joint 500, a larger gap can be secured when using the R410A refrigerant than when using an aluminum material for the Oldham joint. . Accordingly, it is possible to prevent wear due to sliding between the key 614 and the key grooves 206 and 399.

Further, in the present embodiment, the following device is also made.
As shown in FIGS. 3 and 4, the width of the key groove 399 of the frame 400 when the compressor is stopped is L1, the width of the key 614 of the Oldham joint 500 is L2, and the linear expansion coefficient of the frame is α1, and the Oldham joint. , And the temperature rise degree of the key 614 and the frame 400 of the Oldham coupling 500 is ΔT (discharged gas temperature during compressor operation−temperature in a stopped state). During the compressor operation, the keyway 399 of the frame 400 and the key 614 of the Oldham coupling 500 are at a high temperature such as the discharge gas temperature. Therefore, if the width of the keyway 399 of the frame 400 during operation of the compressor is L1 ′ and the width of the key 614 of the Oldham coupling 500 is L2 ′,
L1 ′ = L1 (1 + α1 · ΔT) (1)
L2 ′ = L2 (1 + α2 · ΔT) (2)
Holds. Thus, the gap δ between the keyway of the frame 400 during operation of the compressor and the key 614 of the Oldham coupling 500 is
δ = L1′−L2 ′
= L1 (1 + α1 · ΔT) −L2 (1 + α2 · ΔT) (3)
It becomes.

From the above formula (3), the condition for ensuring the clearance δ during the compressor operation is “δ> 0”. That is,
L1 (1 + α1 · ΔT) −L2 (1 + α2 · ΔT)> 0
１ L1 (1 + α1 · ΔT)> L2 (1 + α2 · ΔT) (4)
It becomes.

  When the R32 refrigerant is used, the discharge gas temperature is higher by about 20 ° C. to 30 ° C. than the R22 or R410A refrigerant. That is, since the temperature of the Oldham joint and the frame is about “120 + 20 to 30 ° C. = 140 ° C. to 150 ° C.”, the temperature increase ΔT is about 20 ° C. to 30 ° C. higher than that of the R410A refrigerant.

  For example, if “L1 = 8.02 mm, L2 = 8.01 mm, α1 = 12.1 × 10E-6 / K (casting), α2 = 23 × 10E-6 / K (aluminum)”, R410A refrigerant Since “ΔT = 120−20 = 100” and δ = 0.0014 mm, a gap can be secured. However, when R32 refrigerant is used, if “ΔT = 150−20 = 130”, δ = −0.0013 mm and a gap cannot be secured.

  Therefore, in the case of the scroll compressor using the R32 refrigerant, the width L1 of the key groove 399 of the frame 400, the width L2 of the key 614 of the Oldham coupling 500, and the material are “δ> 0”, that is, the above formula (4). By satisfying the configuration, the gap δ during the operation of the compressor can be sufficiently ensured even when the R32 refrigerant is used. Thereby, it is possible to prevent wear due to sliding.

In this embodiment, more specifically, the heat-resistant class 180 (H) is used as the stator insulating material, the width of the key groove formed in the frame is L1, the linear expansion coefficient of the frame is α1, and the Oldham The relationship between the key groove width L1 of the frame and the key width L2 of the Oldham joint when the width of the key formed on the joint is L2 and the linear expansion coefficient of the Oldham joint is α2 is L1 × (1 + α1 × 160) > L2 × (1 + α2 × 160) (5)
It is comprised so that it may satisfy. In this mathematical formula (5), the temperature rise ΔT in the mathematical formula (4) is 160, which is an upper limit temperature of use of 180 ° C. when the heat resistance class 180 (H) is used as the stator insulating material, This is the difference from the temperature of 20 ° C. when the compressor is stopped.

  Note that the key groove 206 of the orbiting scroll 200 engaged with the key 614 of the Oldham joint 500 also satisfies the above formula (4) or the above formula (5), as in the case of the key groove 399 of the frame 400. Is configured to do.

  Since the scroll compressor of the present embodiment is configured as described above, even if the discharge gas temperature rises using R32 as a refrigerant, the compressor is configured with components having high heat resistance. Thus, it is possible to obtain a scroll compressor that prevents adverse effects due to temperature rise and has excellent reliability.

  That is, the reliability of the scroll compressor when using the R32 refrigerant that increases the discharge gas temperature is ensured by making each part of the scroll compressor a part with high heat resistance that can be used at temperatures exceeding 120 ° C. can do.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1: scroll compressor, 2: compression mechanism unit, 3: drive unit,
7a: Stator slot, 7b: Teeth portion, 7c: Core back,
21: Stator winding,
100: fixed scroll, 101: base plate, 102: lap,
103: suction port, 104: discharge port, 105: end plate surface,
130: compression chamber,
200: Orbiting scroll 201: Base plate 202: Lap
203: Orbiting scroll bearing, 205: Oiling pocket, 206: Keyway,
210: plain bearing,
300: Rotating shaft, 301: Crank pin, 302: Main shaft part,
303: Sub-bearing support part, 311: Oil passage, 312: Side hole,
399: Keyway of frame, 400: Frame,
401: Rolling bearing (main bearing), 401a: Bearing support, 401b: Compression mechanism support,
402: Thrust bearing, 403: Frame cover,
405, 406, 805: bolts,
407: Balance weight,
408: Oil drain pipe, 410: Seal ring, 411: Back pressure chamber,
500: Oldham coupling,
600: Electric motor, 601: Stator, 601a: Coil end,
602: Rotor, 603: Rotor core,
604: magnet groove, 605: permanent magnet, 606: stator core,
614: Oldham coupling key,
700: Airtight container, 701: Discharge pipe, 702: Hermetic terminal, 703: Terminal cover,
710: upper cap, 711: suction pipe, 720: lower cap, 721: leg,
722: Magnet, 730: Oil sump,
801: Lower frame, 802: Housing, 803: Rolling bearing (sub bearing),
804: Housing cover,
900: Pump part, 901: Refueling hole.

Claims (7)

As a compression mechanism portion having a fixed scroll and a turning scroll, a frame for supporting the compression mechanism portion, an electric motor for driving the compression mechanism portion via a rotating shaft , and a main bearing for supporting the main shaft portion of the rotating shaft A rolling bearing, a rolling bearing as a secondary bearing that supports a secondary bearing support portion of the rotary shaft, a key groove formed in the frame, and a key that engages with a key groove formed in the orbiting scroll, A scroll compressor for a refrigeration apparatus comprising an Oldham coupling for making a turning motion while preventing the rotation of the orbiting scroll, and a sealed container for housing the components,
R32 simple substance refrigerant is used as the refrigerant for the refrigeration apparatus,
The temperature rise of the key of the Oldham joint and the frame is ΔT, the width of the key groove formed in the frame is L1, the coefficient of linear expansion of the frame is α1, and the width of the key formed in the Oldham joint is L2. When the linear expansion coefficient of the Oldham joint is α2, the relationship between the keyway width L1 of the frame and the key width L2 of the Oldham joint is ΔT = 130 ° C.
L1 (1 + α1 · ΔT)> L2 (1 + α2 · ΔT)
Scroll compressor characterized by being configured to satisfy The scroll compressor according to claim 1,
When the width of the key groove formed on the orbiting scroll is L1, the linear expansion coefficient of the orbiting scroll is α1, the width of the key formed on the Oldham joint is L2, and the linear expansion coefficient of the Oldham joint is α2, The relationship between the keyway width L1 of the orbiting scroll and the key width L2 of the Oldham joint is L1 (1 + α1 · ΔT)> L2 (1 + α2 · ΔT)
Scroll compressor characterized by being configured to satisfy A scroll compressor according to claim 2,
A scroll compressor characterized by applying an iron-based sintered material to an Oldham joint. The scroll compressor according to any one of claims 1 to 3,
The rolling bearing that supports the rotating shaft uses a material that has been subjected to dimensional stabilization treatment (TS treatment) that suppresses dimensional changes under high temperature use by tempering at high temperature to stabilize the structure. A scroll compressor characterized by that. The scroll compressor according to claim 4,
As the stator insulating material of the motor, any one of JIS C4003: heat resistance class 130 (B), heat resistance class 155 (F) or heat resistance class 180 (H) defined in electrical insulation is used. Compressor. The scroll compressor according to claim 5,
A scroll compressor characterized in that a heat resistant class 180 (H) is used as the stator insulating material. The scroll compressor according to claim 6,
A scroll compressor characterized in that a magnet of a rotor of the electric motor is composed of a ferrite magnet.

Images