JP4134331B2 - Hermetic scroll compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hermetic scroll compressor, and is particularly suitable for a hermetic scroll compressor used in a refrigerating and air conditioning apparatus in the field of refrigerating and air conditioning using fluorocarbon gas or helium gas as a working gas, a cryopump apparatus in an ultrahigh vacuum field, and the like. It is a thing.
[0002]
[Prior art]
A conventional hermetic scroll compressor is provided with a motor protector that opens and closes the electric motor based on an abnormal increase in motor current and an abnormal increase in ambient temperature. There is one that is fixed to the inner wall surface of a staying sealed container (prior art 1).
[0003]
As another conventional hermetic scroll compressor, as disclosed in Japanese Patent Application Laid-Open No. 2001-304147 (Patent Document 1), the motor on the flow path of the discharge gas from the discharge port of the fixed scroll to the discharge pipe is heated. There is a motor protector that can detect an electric current, and the compressor is stopped before the vortex breakage and bearing seizure are detected by detecting the temperature of the motor protector (Prior Art 2).
[0004]
[Patent Document 1]
JP 2001-30414 A
[0005]
[Problems to be solved by the invention]
In the prior art 1 described above, since the motor protector is fixed to the inner wall surface of the hermetic container in the portion where the working gas flow is stagnant at a flow velocity of 0.3 m / s or less, the cooling effect by the working gas flow on the motor protector is sufficient It was not obtained. For this reason, there existed a problem that the ambient temperature of a motor protector became comparatively high and the performance and function of a motor protector fell.
[0006]
Further, in the above-described prior art 2, it is disclosed that the motor protector is provided in the motor on the flow path of the discharge gas, but there is no disclosure of the specific configuration, and the motor protector is simply provided on the outer surface of the motor. In this case, the cooling effect by the working gas flow on the motor protector cannot be sufficiently obtained. In this case, like the prior art 1, the ambient temperature of the motor protector becomes relatively high, and there is a problem that the performance and function of the motor protector are deteriorated.
[0007]
An object of the present invention is to obtain a hermetic scroll compressor capable of increasing the operating current value by promoting the cooling of the motor protector and extending the life of the protector contact portion.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a scroll compressor unit and an electric motor unit housed in a sealed container, a fixed scroll that erects the spiral wrap on the end plate, and a revolving scroll that erects the spiral wrap on the end plate. The scroll compressor part is formed by meshing with the wraps inside each other, and a discharge port for discharging the compressed working gas into the space in the sealed container is provided in the fixed scroll, and is discharged into the sealed container. In a hermetic scroll compressor provided with a discharge pipe for discharging the working gas to the outside, the flow of the working gas from the discharge port to the discharge pipe Has a portion to be contracted, before and after the portion to be contracted A motor protector that directly opens the motor circuit of the electric motor unit based on an abnormal increase in motor current and an abnormal increase in ambient temperature is disposed in the gas flow path unit.
[0009]
The other means of the present invention will be clarified from the following description.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Several embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.
[0011]
A hermetic scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS. This hermetic scroll compressor is a vertical compressor and is used for a refrigeration air conditioner.
[0012]
In FIG. 1, a hermetic scroll compressor 100 is configured by storing a scroll compressor unit 2 and an electric motor unit 3 in a hermetic container 1, and specifically, scrolls upward in a vertically long hermetic container 1. It is a vertical type in which the compressor unit 2 is stored and the electric motor unit 3 is stored below. The sealed container 1 is divided into two rooms 1a and 1b (that is, an upper chamber 1a and an electric motor chamber 1b) by a frame 7. Furthermore, the inside of the electric motor room 1b is divided into two rooms 1b1, 1b2 (that is, the upper electric motor room 1b1 and the lower electric motor room 1b2) by the electric motor unit 3.
[0013]
The scroll compressor unit 2 includes a fixed scroll 5, a turning scroll 6, and a frame 7. The fixed scroll 5 and the orbiting scroll 6 are arranged in mesh with each other, and a compression chamber (sealed space) 8 is formed between them.
[0014]
The fixed scroll 5 includes a disc-shaped end plate 5a, and a wrap 5b that is formed upright and has an involute curve or an approximate curve, and discharges the working gas from the compression chamber 8 to the center. In addition, a discharge port 10 is formed, and a suction port 14 for sucking the working gas into the compression chamber 8 is provided on the outer peripheral portion. The discharge port 10 is opened to the discharge chamber 1a.
[0015]
The orbiting scroll 6 includes a disk-shaped end plate 6a, a wrap 6b that stands upright and is formed in the same shape as the wrap 5b of the fixed scroll 5, and a boss portion 6c that is formed on the opposite wrap surface of the end plate 6a. Configured.
[0016]
Bearings 39 and 40 are provided at the center of the frame 7. The rotary shaft 14 is supported on these bearing portions 39 and 40. The outer periphery of the frame 7 is fixed to and supported by the sealed container 1. An eccentric shaft 14 a is formed on one side of the rotation shaft 14. The eccentric shaft 14a is inserted into the boss portion 6c of the orbiting scroll 6 so that the orbiting motion is possible. A fixed scroll 5 is fixed to the frame 7 by a plurality of bolts 81.
[0017]
The orbiting scroll 6 is disposed between the frame 7 and the orbiting scroll 6 and is supported on the frame 7 by an Oldham mechanism 38 including an Oldham ring and an Oldham key, and is configured to perform an orbiting motion without rotating with respect to the fixed scroll 5. Has been. An electric motor shaft 14 b is formed on the other side of the rotating shaft 14. The motor unit 3 is directly connected to the motor shaft 14b.
[0018]
A suction pipe 17 extending through the sealed container 1 is connected to the suction port 16 of the fixed scroll 5. A check valve 13 is provided at the suction port 16. An O-ring 53 that seals the high pressure portion and the low pressure portion is provided between the suction pipe 17 and the fixed scroll 5.
[0019]
The upper chamber 1a in which the discharge port 10 is open communicates with the electric motor chamber 1b through passages 18a and 18b. The passage 18 a is formed by a gap between the orbiting scroll 6 and the side wall 1 m of the sealed container 1, and the passage 18 b is formed by a gap between the frame 7 and the side wall 1 m of the sealed container 1.
[0020]
The electric motor unit 3 is disposed in an electric motor chamber 1b formed below the scroll compressor unit 2, and includes an electric motor stator 3a fixed to the side wall 1m of the hermetic container 1, and an electric motor rotor 3b fixed to the electric motor shaft 14b. It is configured with. The electric motor unit 3 is composed of a three-phase motor, and the motor circuit is a circuit in which an internal motor protector 91 is installed at a neutral point 3k of the star connection as shown in FIG. Contact points (current interrupting portions) 91p are respectively provided for the three-phase two motor coils 3e. As a result, the motor protector 91 having a direct cut function (a function of directly opening the motor circuit) that energizes the motor coil 3e based on the abnormal increase in the motor current and the abnormal increase in the gas temperature. The two contact points 91p are always closed in the normal state and open in the case of abnormality. Specifically, the contact portions 91n and 91p have a bimetal structure. The motor protector 91 has a terminal 91b for connecting to the motor coil 3e. A hermetic terminal 37 for energizing the motor unit 3 is attached to the sealed container 1.
[0021]
The electric motor chamber 1 b communicates with a discharge pipe 20 that penetrates the sealed container 1. Accordingly, the discharge port 10 and the discharge pipe 20 are communicated with each other via the discharge chamber 1a, the passages 18a and 18b, and the electric motor chamber 1b. Further, the upper portion 1b1 and the lower portion 1b2 of the electric motor chamber 1b communicate with each other via a gap 25a between the electric motor stator 3a and the electric motor rotor 3b, and a gap 25b between the electric motor stator 3a and the side wall 1m of the sealed container 1. . The balance weight 9a provided on the rotating shaft 14 and the subweight 9b provided on the electric motor rotor 3b are for canceling the centrifugal force generated by the orbiting motion of the orbiting scroll 6.
[0022]
A space 36 (hereinafter referred to as a back pressure chamber) surrounded by the scroll compressor unit 2 and the frame 7 is formed on the back surface of the end plate 6 a of the orbiting scroll 6. A pressure intermediate between the suction pressure and the discharge pressure is introduced into the back pressure chamber 36 through the pores 6 d formed in the end plate 6 a of the orbiting scroll 6. As a result, an axially applied force for pressing the orbiting scroll 6 against the fixed scroll 5 is applied.
[0023]
The lubricating oil 22 is stored at the bottom of the sealed container 1. The lubricating oil 22 is sucked up through the oil suction pipe 27 by the differential pressure between the high pressure in the sealed container 1 and the intermediate pressure in the back pressure chamber 23, and then rises in the central hole 13 in the rotating shaft 14, Oil is supplied from the upper end opening of the central hole 13 to the slewing bearing 32 and from the auxiliary bearing 39 (slide bearing portion) to the main bearing 40 (cylindrical roller bearing portion) through the lateral hole 51. The lubricating oil 22 supplied to the bearings 32, 39, 40 is injected into the compression chamber 8 through the hole 6d through the back pressure chamber 36, mixed with the compressed gas, and discharged to the upper chamber 1a together with the discharge gas. The The oil plate 47 is disposed on the oil surface of the lubricating oil 22.
[0024]
A motor protector 91 is disposed in the flow path portion 1g which is the main flow of the gas flow in the vicinity of the gas outlet to the discharge pipe 20 serving as the gas discharge port of the compressor. The flow path portion 1g is an inlet side (front side) portion of the discharge port 10 that is a contracted flow portion, and is a portion where the flow velocity of the working gas is particularly faster than the flow of a wide space portion in the electric motor chamber 1b. The motor protector 91 is held by a holder 90 fixed to the inner wall surface 1m. The lead wire 91a connects the three-phase motor coil 3e and the terminal portion of the motor protector 91. The motor protector 91 directly opens the motor circuit of the three-phase motor. Specifically, the motor protector 91 has a function of opening a contact inside the protector when the motor current and the ambient gas temperature are abnormally increased, and turning off the motor circuit. Yes. As a result, the motor protector 91 can prevent excessive current from flowing through the motor circuit to prevent motor burnout, thereby protecting the compressor.
[0025]
In the above configuration, when the motor unit 3 is energized and the motor rotor 3b is rotated, the motor shaft 14b directly connected to the motor rotor 3b is rotated and the eccentric shaft 14a is eccentrically rotated. As a result, the orbiting scroll 6 is orbited through the orbiting bearing 32. By this turning motion, the compression chamber 8 gradually moves from the periphery to the center, and the volume decreases. Along with this, the working gas enters the suction chamber 5f from the suction pipe 17 through the suction port 16 and compression is started in the compression chamber 8, and the oil that has lubricated the bearings 32, 39, and 40 is the orbiting scroll of the orbiting scroll 6. It flows into the compression chamber 8 from the narrow hole 6d of the end plate 6a and mixes with the working gas. The working gas containing oil is compressed in the compression chamber 8 and then discharged from the discharge port 10 to the upper chamber 1a and flows into the electric motor chamber 1b through the passages 18a and 18b. In FIG. 1, solid arrows indicate the flow of chlorofluorocarbon, which is a working gas, and broken arrows indicate the flow of oil.
[0026]
The working gas (including oil) that has flowed into the wide motor chamber 1b from the narrow passages 18a and 18b passes through the gaps 25a and 25b in the vertical direction to the lower motor chamber 1b2, and again upwards toward the upper motor chamber. 1b1. In this process, a part of the oil contained in the working gas is separated. On the other hand, the working gas that has flowed into the motor chamber 1b and collided with the upper surface of the motor stator 3a has its flow direction changed, and in the process, part of the oil contained in the gas is separated and further passes around the motor protector 91. Then, after the cooling of the protector 91 is promoted, it flows into the discharge pipe 20. The separated oil flows down through the gap 25b in the outer periphery of the motor stator and stays at the bottom of the sealed container 1.
[0027]
FIG. 3 is a motor protector characteristic diagram showing the relationship between the operating current of the motor protector 91 and the ambient temperature around the protector. As shown in FIG. 3, in the case of the atmospheric temperature Tp, the operating current value of the motor protector is as low as k1 in the prior art 1, whereas the operating current value of the motor protector 91 is as high as k2 in this embodiment. ing. This means that the compressor overload condition by the motor protector 91 can be increased by arranging the motor protector 91 at an optimum position (that is, a portion where the speed of the working gas flowing through the sealed container 1 is particularly fast). Therefore, for example, the discharge pressure can be ensured higher than that of the conventional technique 1. Thereby, in the present embodiment, an effect that the operation range can be set wide is obtained.
[0028]
FIG. 4 is a characteristic diagram showing the relationship between the protector ambient temperature and the service life. By lowering the motor protector ambient temperature, the temperature of the protector contact portion 91p can be lowered when an overcurrent flows in the motor circuit, thereby reducing the on / off frequency of the contact portion 91p. Therefore, as shown in FIG. 4, the effect of improving the life of the motor protector 91 can be obtained. Since the bimetal type motor protector 91 is used, when the motor current and the atmospheric temperature return to normal, the contact portions 91p and 91n are closed again, the motor circuit is energized, and the operation of the motor unit 3 is automatically restored. .
[0029]
Next, a hermetic scroll compressor according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment as described below, and is basically the same as the first embodiment in other points.
[0030]
In the second embodiment, the motor protector 91 is disposed in the flow path portion 1k that is located above the stator coil end portion 3c and is the main flow of the gas flow in the vertical direction of the passage 18b. This flow path portion 1k is an outlet side (rear side) portion of the passage 18b which is a contracted flow portion, and the flow velocity of the working gas is particularly faster than the flow of the stagnant working gas in the wide space portion in the motor chamber 1b. Part. In particular, since the working gas flowing down the passage 18b has a high gas velocity and contains a large amount of oil, the cooling effect of the protector 91 can be used more effectively. The working gas that has cooled the periphery of the motor protector 91 then flows in the same manner as in the first embodiment described above and flows out of the discharge pipe 20.
[0031]
According to the second embodiment, the cooling effect of the motor protector 91 can be further enhanced, and thereby the compressor can be more reliably protected.
[0032]
Next, an oil-sealed hermetic scroll compressor according to a third embodiment of the present invention will be described with reference to FIGS. In the description of the third embodiment, a part of the description overlapping with the first embodiment is omitted.
[0033]
The hermetic scroll compressor 100 has a horizontal configuration in which a scroll compressor unit 2 and an electric motor unit 3 are arranged in the left and right in a hermetic container 1. A side cover 72 that is provided in the motor chamber 1b and supports the auxiliary bearing 239 is provided. The side cover 72 constitutes a cover that covers the downstream side of the electric motor unit 3. A gas guide passage 319 is provided in communication with the gas discharge opening 72e. A motor protector 91 is disposed inside the gas guide passage portion 319.
[0034]
In this third embodiment, the working gas is helium gas, and as shown in FIG. 6, an oil injection pipe 31 for cooling the working gas is passed through the S cap 1 d of the sealed container 1, and the fixed scroll 5 The oil injection port 19 is connected to the oil injection port 19 provided on the end plate part 5a, and the oil injection mechanism part is constituted by these. The opening portion of the oil injection port 19 is opened facing the tooth tip surface of the wrap 6 b of the orbiting scroll 6.
[0035]
The scroll compressor portion 2 is accommodated on the suction pipe 17a side in the sealed container 1, and the electric motor portion 3 is accommodated on the opposite side. The sealed container 1 is partitioned into an electric motor chamber 1b with the discharge chamber 1a and the frame 7 interposed therebetween. The scroll compressor unit 2 forms a compression chamber (sealed space) 8 by meshing the fixed scroll 5 and the orbiting scroll 6 with each other.
[0036]
As shown in FIG. 6, FIG. 10 and FIG. 11, the fixed scroll 5 is composed of a disc-shaped end plate 5a and a wrap 5b which stands upright on this and is formed in an involute curve or a curve approximate thereto. A discharge port 10 is provided in the part and a suction port 16 is provided in the outer peripheral part. An oil injection port 19 is formed through the end plate 5a. One oil injection port 19 can inject cooling oil into the adjacent compression chamber 8 and is provided at the center position of the wrap groove 5f having the groove diameter Dt. The hole diameter d of the oil injection port 19 ₀ Is set to a value larger than the wrap thickness t to prevent an oil hammer phenomenon during oil injection.
[0037]
As shown in FIG. 6, the orbiting scroll 6 is formed on a disc-shaped end plate 6a, a wrap 6b that stands upright and formed in the same shape as the wrap 5b of the fixed scroll 5, and an anti-wrap surface of the end plate 6a. The boss portion 6c is provided.
[0038]
The frame 7 is provided with bearings 39 and 40 at the center. The rotary shaft 14 is supported on these bearings 39 and 40. An eccentric shaft 14 a is formed on one side of the rotation shaft 14. The eccentric shaft 14a is inserted into the boss portion 6c of the orbiting scroll 6 so that the orbiting motion is possible. Further, the frame 7 is formed with a cylindrical side wall 7 a that supports the electric motor unit 3. The peripheral edge of the side wall 7a on the side of the scroll compressor is formed in a flange shape, and the outer periphery of the peripheral edge is fixed to the sealed container 1. The electric motor unit 3 is supported in the side wall 7a. A fixed scroll 5 is fixed to the frame 7 by a plurality of bolts 81. The orbiting scroll 6 is disposed between the frame 7 and the orbiting scroll 6 and is supported on the frame 7 by an Oldham mechanism 38 including an Oldham ring and an Oldham key, and is configured to perform an orbiting motion without rotating with respect to the fixed scroll 5. Has been. An electric motor shaft 14 b is formed on the other side of the rotating shaft 14. The motor unit 3 is directly connected to the motor shaft 14b.
[0039]
A suction pipe 17 is connected to the suction port 16 of the fixed scroll 5 through the sealed container 1. The suction pipe 17 is composed of a suction pipe 17a and a joint pipe 17b. An O-ring 53 that seals the high pressure portion and the low pressure portion is provided between the suction pipe 17 and the fixed scroll 5. A check valve 13 is provided in the suction port 16. The check valve 13 is provided for preventing the reverse rotation of the rotary shaft 14 when the compressor is stopped and for preventing the lubricating oil 22 in the sealed container 1 from flowing out to the low pressure side.
[0040]
The discharge chamber 1a in which the discharge port 10 is open communicates with the electric motor chamber 1b through passages 18a and 18b. The electric motor chamber 1b communicates with a discharge pipe 20 that passes through the central casing 1e of the sealed container 1. The electric motor chamber 1b is partitioned into left and right spaces 1b1 and 1b2 by the frame 7 and the electric motor unit 3. The space 1b1 and the space 1b2 are communicated with each other via a gap 25c between the motor stator 3a and the side wall 7a of the frame 7, and a gap 25a between the motor stator 3a and the motor rotor 3b.
[0041]
A hole 7 b is formed at the lower end of the frame 7. The hole 7b is an oil hole for moving the oil 22a accumulated in the discharge chamber 1a to the oil chamber 22b on the motor chamber 1b side. The direction change block 115 is a component that is provided so as to cover the discharge port 10 and that directs the working gas and oil that have come out of the discharge port 10 upward from the horizontal direction. By this direction change block 115, a relatively large amount of oil can be guided to the passage 18a side, and the oil can be sprayed directly onto the electric motor unit 3 through the space 1b1 to enhance the motor cooling and the cooling effect on the motor protector 91. The oil level gauge 45 is provided for managing the oil level during operation. The power supply unit 57 is provided outside the portion of the sealed container 1 that faces the motor protector 91.
[0042]
Further, a back pressure chamber 36 surrounded by the scroll compressor unit 2 and the frame 7 is formed on the back surface of the end plate 6 a of the orbiting scroll 6. An intermediate pressure between the suction pressure and the discharge pressure is introduced into the back pressure chamber 36 through the pores 6 d formed in the end plate 6 a of the orbiting scroll 6. As a result, an axially applied force for pressing the orbiting scroll 6 against the fixed scroll 5 is applied.
[0043]
The lubricating oil 22 is stored at the bottom of the sealed container 1. The lubricating oil 22 is sucked up into the oil suction pipe 96d by the differential pressure between the high pressure in the sealed container 1 and the intermediate pressure in the back pressure chamber 36, and then flows through the rotary shaft 14 to form the swivel bearing 32 and the auxiliary Oil is supplied to the bearing 39 and the main bearing 40. The lubricating oil 22 supplied to the bearings 32, 39, and 40 is injected into the compression chamber 8 through the hole 6d through the back pressure chamber 36, mixed with the compressed gas, and discharged to the discharge chamber 1a together with the discharge gas. An oil take-out pipe 30 for taking out the lubricating oil 22 at the bottom is provided at the bottom of the sealed container 1. The lubricating oil 22 stored at the bottom of the sealed container 1 is taken out by the pressure difference between the pressure in the sealed container 1 (discharge pressure) and the pressure in the compression chamber 8 (pressure at the opening of the port 19 below the discharge pressure). The oil flows into the oil take-out pipe 30 from the inflow portion 30 a of the pipe 30.
[0044]
As shown in FIGS. 6 to 8, the side cover 72 includes an outer peripheral cylindrical portion 72a, a central cylindrical portion 72b, and a bottom portion 72c. A plurality of flange portions are formed on the distal end side of the outer peripheral cylindrical portion 72a, and holes 72d are formed in the flange portions. The side cover 72 is attached to the end surface of the side wall 7a of the frame 7 by a bolt 74 through the hole 72d. A sub-bearing 239 is provided in the central cylindrical portion 72b, and the end of the motor shaft 14b is supported by the sub-bearing 239. A gas discharge opening 72e and a lead wire hole 72f are formed in the bottom portion 72c.
[0045]
A gas guide passage part 319 and a holder 90 having a protector holding function are provided on the gas discharge side (reverse motor part side) of the gas discharge opening 72e of the side cover 72. The holder 90 is detachably attached to the side cover 72 with screws or the like. On the other hand, the hole 72f of the side cover 72 is a dedicated hole through which the motor lead wire 360 and the three-phase neutral point lead wire 91a inside the stator 3a pass. Since the motor circuit of the third embodiment is the same as the motor circuit of the first embodiment (see FIG. 2), description thereof is omitted.
[0046]
The motor protector 91 is disposed inside the gas guide passage portion 319 and attached to the holder 90. The lead wire 91a is fixed to the side cover wall surface 72c with a stopper 372.
[0047]
The working gas (including oil) that has flowed into the space 1b1 from the passage 18b reaches the space in the side cover 72 through the passage 25c and the gap 25a. At this time, the working gas cools the electric motor unit 3 (in other words, heated by the electric motor unit 3). In this space, a part of the oil is separated and collected at the bottom of the sealed container 1. The main flow of the working gas flowing into this space is guided to the gas guide passage part 319 from the gas discharge opening 72e, passes around the motor protector 91, and flows out into the wide space 1b2. Here, the gas discharge opening 72e constitutes a contracted portion, and the flow velocity of the working gas discharged from the gas discharge opening 72e is particularly fast in the gas guide passage portion 319. That is, the motor protector 91 is disposed in the gas flow region where the main flow velocity of the working gas is 1 to 3 m / s. Therefore, the motor protector 91 built in the gas guide passage portion 319 is cooled by this particularly fast working gas. Moreover, since the heat sensitive part of the motor protector 91 is attached to the side cover 72 so as to face the discharge side of the gas discharge opening 72e, the heat sensitive part of the motor protector 91 can be effectively cooled with the working gas. A part of the oil contained in the working gas that has flowed out from the gas guide passage part 319 into the wide space 1b2 is separated and stored at the bottom of the sealed container 1, and the remaining working gas flows out through the discharge pipe 20 to the outside. Is done.
[0048]
In the third embodiment, as shown in FIG. 3, the operating current value of the motor protector 91 is as high as k3. This means that the compressor overload condition by the motor protector 91 can be made larger than in the first embodiment, so that, for example, the discharge pressure can be secured higher than in the first embodiment. Thereby, in the third embodiment, an effect that the operation range can be set wider is obtained.
[0049]
Next, an oil-filled hermetic scroll compressor according to a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is different from the third embodiment as described below, and is basically the same as the third embodiment in other points.
[0050]
In the fourth embodiment, a gap 286 is provided between the side cover 72 and the flange portion 91 a of the motor protector 91 via a spacer piece 296. By setting the gap 286, the resistance of the gas flow is reduced, the gas flow to the motor protector 91 is smoothed, and the cooling effect is improved. Even if the gap 286 is a minute gap of about 1 mm, the above effect can be obtained.
[0051]
Next, a helium refrigerating apparatus according to a fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, the oil-sealed hermetic scroll compressor of the third or fourth embodiment described above is used as the hermetic scroll compressor 100.
[0052]
The lubricating oil 22 stored at the bottom of the sealed container 1 is taken out by the pressure difference between the pressure in the sealed container 1 (discharge pressure) and the pressure in the compression chamber 8 (pressure at the opening of the port 19 below the discharge pressure). The oil flows into the oil take-out pipe 30 from the inflow portion 30 a of the pipe 30. The oil that has flowed into the oil take-out pipe 30 reaches the oil strainer 56 and the oil cooler 33 through the external oil pipe 51, where it is appropriately cooled, and then reduced in pressure through the oil injection pipe 53 by the oil flow rate adjustment valve 53. Further, the gas is injected into the compression chamber 8 through the oil injection pipe 31 and through the port 19 to cool the helium gas. An oil flow rate adjusting valve 53 is provided between the oil injection pipes 53 and 31 so that the oil amount can be adjusted.
[0053]
The oil injected into the compression chamber 8 in this manner serves to cool the working gas in the compression chamber 8 and lubricate sliding portions such as the scroll wrap tip. The oil is compressed together with the working gas, and then discharged from the discharge port 10 into the upper chamber 1a. The oil is separated from the working gas in the electric motor chamber 1b and stored in the bottom of the hermetic container 1 as described above.
[0054]
On the other hand, the helium gas discharged from the compressor 100 is separated by the oil separator 70 and then cooled by the gas cooler 50. Next, the helium gas is adiabatically expanded in the helium refrigerator 80 and then returns to the compressor 100 as the suction gas again through the pipes 340 and 300.
[0055]
The effects based on the configuration of the embodiment described above are summarized as follows.
[0056]
Positioning the motor protector in a gas flow or a mixed flow of mist-like oil and gas promotes cooling of the protector itself, increases the maximum operating current of the motor protector, and shuts off overcurrent It is possible to extend the life of the protector contact part that becomes the part. As a result, the motor protector can be reduced in size and weight, and the cost can be reduced.
[0057]
In addition, since the life of the motor protector can be extended, the life and reliability of the compressor as a whole can be greatly improved.
Moreover, since the overload condition of the compressor can be increased by arranging the motor protector at the optimum position, the discharge pressure can be secured higher than before and the operation range can be set wider.
[0058]
Especially in the case of a scroll compressor for helium, the gas atmosphere temperature around the motor protector can be further reduced by the cooling effect due to oil injection, so for the same capacity horsepower class of the scroll compressor for refrigeration and air conditioning of the CFC refrigerant R22 specification, A small motor protector can be used even if the functionality is equivalent.
[0059]
Helium compressors are mainly used in cryopump devices used in semiconductor manufacturing equipment, but the reliability of the motor protector improves the motor protection and leads to compressor protection. Therefore, the effect is extended to the extension of the life of the compressor.
[0060]
【The invention's effect】
As is apparent from the description of the above-described embodiments, according to the present invention, a hermetic scroll compression that promotes cooling of the motor protector to increase the operating current value and prolong the life of the protector contact portion. You can get a chance.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an air-conditioning hermetic scroll compressor according to a first embodiment of the present invention.
FIG. 2 is a motor circuit diagram of the hermetic scroll compressor of FIG.
FIG. 3 is a characteristic diagram of the protector ambient temperature of the hermetic scroll compressor of the prior art 1 and the first and second embodiments of the present invention.
FIG. 4 is a characteristic diagram showing protector durability of the hermetic scroll compressor according to the prior art 1 and the first embodiment of the present invention.
FIG. 5 is a longitudinal sectional view of an air conditioning hermetic scroll compressor according to a second embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of an oil-filled hermetic scroll compressor according to a third embodiment of the present invention.
7 is a side view of a side cover portion (a state where a motor protector is omitted) of the hermetic scroll compressor of FIG. 6; FIG.
8 is a side view of a side cover portion (with a motor protector) of a fixed scroll of the hermetic scroll compressor of FIG. 6. FIG.
9 is an enlarged cross-sectional view of a main part of the hermetic scroll compressor of FIG. 6. FIG.
10 is a front view of a fixed scroll of the hermetic scroll compressor of FIG. 6;
11 is a cross-sectional view of a fixed scroll of the hermetic scroll compressor of FIG. 6;
FIG. 12 is a longitudinal sectional view of an oil-filled hermetic scroll compressor according to a fourth embodiment of the present invention.
FIG. 13 is a configuration diagram of a helium refrigeration apparatus according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sealed container, 1a ... Discharge chamber, 1b ... Electric motor room, 1m ... Side wall, 2 ... Scroll compressor part, 3 ... Electric motor part, 3a ... Electric motor stator, 3b ... Electric motor rotor, 5 ... Fixed scroll, 5a ... Fixed scroll End plate, 5b ... wrap, 5f ... suction chamber, 6 ... turning scroll, 6a ... turning scroll end plate, 6b ... wrap, 6c ... boss part, 8 ... compression chamber, 10 ... discharge port, 7 ... frame, 14 ... rotating shaft, 14a ... eccentric shaft, 14b ... motor shaft, 16 ... suction port, 17 ... suction pipe, 18a, 18b ... passage, 19 ... port, 20 ... discharge pipe, 22 ... lubricating oil, 27 ... oil suction pipe, 30 ... oil Extraction pipe, 30a ... inflow part, 31 ... oil injection pipe, 32 ... slewing bearing, 33 ... oil cooler, 38 ... Oldham mechanism, 39 ... auxiliary bearing, 40 ... main bearing, 50 ... gas cooler, 51 ... oil piping 53 ... O 56 ... oil strainer means, 70 ... oil separator, 72 ... side cover, 91 ... motor protector, 100 ... closed scroll compressor, 72e ... gas discharge opening.

Claims (5)

A scroll compressor unit and an electric motor unit are housed in an airtight container, and the scroll is formed by meshing a fixed scroll that erects a spiral wrap on the end plate and a revolving scroll that erects the spiral wrap on the end plate with the wraps inside each other. A discharge pipe that forms a compressor portion, has a discharge port for discharging the compressed working gas into the space in the sealed container in the fixed scroll, and discharges the working gas discharged into the sealed container to the outside. In a hermetic scroll compressor provided with
Based on the abnormal increase in motor current and the abnormal increase in ambient temperature in the gas flow path part before and after the compressed part, the flow of the working gas from the discharge port to the discharge pipe is reduced. A hermetic scroll compressor comprising a motor protector for directly opening a motor circuit of the electric motor section. The working gas discharged from the discharge port is configured to reach the discharge pipe through the electric motor part, and a gas flow path part having a high flow velocity is formed on the downstream side of the electric motor part in the flow of the working gas, hermetic scroll compressor according to claim 1, characterized in that this is arranged the motor protector in the gas flow passage portion. A cover for covering the downstream side of the electric motor part in the flow of the working gas is provided, a gas discharge opening is formed in a part of the cover, and the heat sensitive part of the motor protector is opposed to the discharge side of the gas discharge opening. 3. The hermetic scroll compressor according to claim 2 , wherein the hermetic scroll compressor is attached to a cover. The working gas is helium gas, and an oil injection pipe for cooling the working gas in the working chamber of the compression mechanism is passed through the sealed container and connected to an oil injection port provided on the end plate of the fixed scroll. comprising an oil injection mechanism, according to any one of claims 1 to 3, characterized in that a said motor protector in the mixture of the flow of the working gas and the mist oil discharged from the discharge port Hermetic scroll compressor. The hermetic scroll compressor according to any one of claims 1 to 4 , wherein a speed of a working gas flow in the gas flow path portion in which the motor protector is disposed is 1 to 3 m / sec.

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