JP2007046532A - Hermetic compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic compressor in a hermetic compressor, which simultaneously improves the cooling performance of a protector main body and secures an insulation space distance and simultaneously solves both problems of leakage current reduction. There is to do.
SOLUTION: The present invention fixes a motor protector means to a top end of a motor coil end with a tie strap through an insulating sheet means, a compressor internal member and an airtight container inner wall facing the protector main body. An insulation distance equal to or greater than an insulation space distance of the hermetic terminal portion for power supply is secured.
[Selection] Figure 1

Description

The present invention is a hermetic scroll compressor, a rotary compressor and a reciprocating compressor used for cryopump apparatuses using refrigerant R22, R410A and the like as working gas and a cryopump apparatus using helium gas. The present invention relates to a shape compressor.

In the conventional hermetic scroll compressor, the motor protector is fixed to the outer surface of the motor coil end with a cylindrical insulating sheet as shown in FIG. There is a structure that is fixed in close contact with the side chamber wall surface.
In addition, there are examples of scroll compressors having a motor protector in Japanese Patent Application Laid-Open Nos. 7-18954, 2001-304147, and 2004-197680.

Japanese Laid-Open Patent Publication No.7-189954 JP 2001-304147 A JP 2004-197680 A

In the above prior art, although the motor protector is fixed to the outer surface of the motor coil end, it is covered with an insulating sheet, so that the cooling action due to the flow of the refrigerant gas cannot be obtained, and the gas flow is stagnant in the first place. Therefore, the cooling effect by the gas flow cannot be obtained. For this reason, protector ambient temperature becomes comparatively warm, the performance and function of the protector are lowered, and the upper limit value of the operating current is lowered. Since the structure fixed to the side chamber wall surface is also a structure in which the gas flow is likely to stagnate, there is a problem that the above-described protector body is not sufficiently cooled. Also, when the motor protector is installed inside the compressor,
Since the space distance between the motor protector charging part and the surrounding insulating part is not optimally secured,
There is an example in which the electrical insulation resistance is lowered to cause insulation failure. At that time, the leakage current during operation of the compressor (a minute current flowing between the compressor main unit and the ground side) rises, reducing the reliability of the compressor as a whole (for example, leading to a motor rare short) and inducing electric shock accidents, etc. There is a problem in ensuring the electrical safety. In the case of an inverter driven hermetic compressor, a high surge voltage of around 1500V acts on the motor and protector as the secondary voltage of the inverter. In this case, the above leakage current becomes abnormally large. There is. In the publicly known example of JP-A-2001-304147,
Although there is a description of the motor protector character, there is no specific structure and position indication. Further, there is no description about the compressor for helium. In addition, in Japanese Patent Application Laid-Open No. 2004-197680, there is an example in which protector means is arranged at a position separated from the motor, but in combination with other references, the insulation space distance and abnormal leakage current intended by the present invention are supported. No structure or description is disclosed. In the compressor with a motor protector of the present invention, as described later,
In order to solve the above-mentioned problems, where the motor protector is arranged inside the compressor and the assembly method is applied is an extremely important technical point. Furthermore, in a conventional scroll compressor, when the compressor horsepower increases, in a large-capacity motor protector through which a large current flows at start-up, the temperature rise of the protector body due to heat generated by the protector increases, and the life of the protector itself Is extremely low. On the other hand, in the conventional separation structure of the motor and the protector disclosed in Japanese Patent Application Laid-Open No. 2004-197680, the response of the protector operation that the motor is abnormally heated and quickly cuts off the motor circuit is deteriorated. There is a problem that the reliability of motor protection is reduced and the motor protection function cannot be achieved.

The present invention provides a compressor structure equipped with an optimal motor protector that can secure the insulation space distance by specifying the protector position and a unique assembling method and solve the problems related to heat generation of the motor protector, and can surely protect the motor. Is to provide. In particular, in the case of a compressor for helium, when the sealing pressure is as low as about 0 to 2 kg / cm 2 G, the influence on the increase in leakage current due to the decrease in the dielectric strength of the diluted helium gas itself, It has been found that when the water content contained is about 10 ppm or more, the above-mentioned problem in terms of electrical safety and compressor reliability that the leakage current during the operation of the compressor becomes large is highlighted.
It is an object of the present invention to provide a hermetic compressor for simultaneously solving the problems of both sides of reduction of leakage current by securing the cooling performance of the protector main body and the insulation space distance.

In order to overcome the above problems, an object of the present invention is to energize a motor coil due to an abnormal increase in motor current and abnormal increase in gas temperature in a hermetic compressor in which a compressor unit and an electric motor unit are housed in a hermetic container. An assembly method in which a motor protector means having a direct cut function for a motor circuit is provided at an upper end portion of a motor coil end, the outer surface of the protector main body is a charge exposed portion, and is fixed by a binding string via an insulating sheet means; In addition, the hermetic compressor is characterized in that the insulating space distance between the compressor inner member facing the protector body and the inner wall of the sealed container is equal to or greater than the insulating space distance of the hermetic terminal for power supply. Structure.

Specifically, in a hermetic compressor having a high-pressure chamber structure, a scroll compressor part and an electric motor part are accommodated in the container, and the scroll compressor part is provided with a spiral wrap upright on a disc-shaped end plate. The fixed scroll and the orbiting scroll are engaged with each other with the laps inside each other, and the orbiting scroll is engaged with an eccentric mechanism that is connected to the rotating shaft, and the orbiting scroll is orbited relative to the fixed scroll without rotating. Is provided with a discharge port that opens in the center and a suction port that opens in the outer periphery, sucks gas from the suction port, moves around the compression chamber formed by both scrolls to reduce the volume and compresses the gas In a hermetic scroll compressor that discharges compressed gas from the discharge port into the container chamber, and further discharges gas to the outside through the discharge pipe,
A motor protector having a direct cut function is provided at the upper end portion of the motor coil end, and a motor circuit that energizes the motor coil due to an abnormal increase in motor current and an abnormal increase in gas temperature in the gas flow path portion that is the main flow of refrigerant gas, The outer surface of the protector main body is a charge exposed portion, and is fixed with a strap through an insulating sheet means, and the coil end portion and the protector means are integrated, and the compressor internal member is opposed to the protector main body. In addition, the insulation space distance from the inner wall portion of the sealed container is ensured to be equal to or greater than the insulation space distance of the hermetic terminal portion for power supply.

Further, when the working gas is helium gas, an oil injection mechanism in which an oil injection pipe for cooling the working helium gas passes through the sealed container and is connected to an oil injection port provided in the end plate portion of the fixed scroll. In the sealed helium scroll compressor provided with a section, at the end of the motor coil end on the downstream side of the flow of the mixture of mist oil and refrigerant gas discharged from the discharge port, an abnormal motor current A motor protector having a direct cut function for a motor circuit that energizes the motor coil due to an increase in gas temperature and an abnormal increase in gas temperature is located at the upper end of the motor coil end, and the outer surface of the protector main body is a charge exposed portion,
While securing with a tie string through an insulating sheet means, the insulation space distance between the frame member facing the protector main body and the inner wall of the sealed container was ensured to be equal to or greater than the insulation space distance of the hermetic terminal for power supply. The protector is arranged at a position.

  Specifically, the motor protector means is located on the upper end surface portion of the motor coil end portion, and the protector is mounted at an inner position equal to or less than the outer diameter of the coil end. It is.

In addition, in order to regulate the amount of water contained in the gas that directly affects the leakage current, the water content in the helium gas is 0.5 ppm or less, and the purity of the helium gas is 99.9999% or higher. It is characterized by using helium gas.

In the case of a hermetic scroll compressor having a low pressure chamber structure in which the pressure inside the container is a low pressure atmosphere, the scroll compressor unit and the electric motor unit are housed in the hermetic container, and the scroll compressor unit The fixed scroll and the orbiting scroll that erect the spiral wrap on the disc-shaped end plate are engaged with each other with the wrap inside, and the orbiting scroll is engaged with an eccentric mechanism that is connected to the rotating shaft, and the orbiting scroll rotates. The fixed scroll is pivoted with respect to the fixed scroll, and the fixed scroll is provided with a discharge port that opens at the center and a suction port that opens at the outer periphery. The suction port is a low-pressure refrigerant from the motor chamber below the frame through the communication passage. Inhale gas, inhale gas from the inlet, move around the compression chamber formed by both scrolls to reduce the volume and compress the gas, In a hermetic scroll compressor that discharges compressed gas to the outside through a discharge pipe, in the motor chamber, an abnormal increase in motor current and abnormal gas temperature occur in the gas flow path that is the mainstream of low-pressure refrigerant gas. A motor circuit for energizing the motor coil by increasing the motor protector means having a direct cut function is fixed to the upper end portion of the motor coil end with a tie string through an insulating sheet means, and the compressor is opposed to the protector main body. The sealed scroll compressor structure is characterized in that the insulating space distance between the inner member and the inner wall portion of the sealed container is secured to be equal to or greater than the insulating space distance of the hermetic terminal for power supply.

In the configuration of the present invention, in a scroll type using a chlorofluorocarbon refrigerant gas and a helium gas, and a rotary type, a reciprocating type hermetic compressor,
(1) By ensuring the insulation space distance reliably, the leakage current of the compressor during operation flowing between the compressor main body and the electric system ground can be greatly reduced, so that electrical safety such as electric shock prevention can be ensured. In addition, failure / trouble (noise generation) of electrical system equipment can be prevented in advance. In particular, in the case of an inverter-driven hermetic compressor, the leakage current is greatly reduced compared to the conventional model even if a high-voltage surge voltage of around 1500 V is applied to the motor and protector as the secondary voltage of the inverter. it can.
(2) In the motor protector means, the outer surface of the main body is a charge exposed part, and the lower end surface of the protector means and the upper end surface part of the motor coil end part are interposed only through the thin-film insulating sheet means.
Responsiveness is dramatically improved and motor protection is ensured by an integrated structure that is fixed in a so-called naked state, which is fixed with a tie string. Further, the forced cooling function by the gas flow flowing around the protector is greatly improved, and the maximum operating current value of the protector is further increased.
It is possible to further extend the life of the protector contact portion serving as an overcurrent interrupting portion.
(3) By disposing the motor protector in the discharge gas on the high-pressure side or the gas flow on the low-pressure side, the cooling action by the gas flow around the protector can be promoted. The overload condition of the compressor can be widened by improving the cooling function. For example, since the discharge pressure can be ensured higher than before, an effect that the operation range can be set wider can be obtained. The so-called maximum operating current value (MCC value) of the protector can be made higher than that of the conventional machine.
(4) According to the above items (1), (2), and (3), the motor protector can be reduced in size and weight. As a result, the cost can be reduced.
(5) Especially in the case of a helium scroll compressor, the cooling effect by oil injection can further reduce the gas atmosphere temperature around the motor protector. For this reason, chlorofluorocarbon refrigerant R
Even if the functionality is equivalent to the same capacity horsepower class of the scroll compressor for refrigeration and air conditioning of 22 specifications, a smaller motor protector can be used, and the cost can be reduced.
(6) Further, as shown in FIG. 11, in the conventional fixing method using a tight string of a hard insulating paper 89, extra protrusions 89a and 89b are generated at the end of the insulating paper, resulting in a coil. Variations in the molding dimensions occurred, but this structure eliminates the occurrence of the protrusions,
The formability (dimensional accuracy) of the protector and coil end part is greatly improved, and the mass productivity can be improved by improving the quality and reducing the number of assembly steps.
(7) Helium compressors are mainly used in cryopumps used in semiconductor manufacturing equipment, but the reliability of the motor protector improves the motor protection, thereby protecting the helium compressor unit. Also leads. The effect will also be extended to prolong the service life of the helium compressor unit.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

A helium hermetic scroll compressor will be described as an example. FIG. 1 is a longitudinal sectional view showing an embodiment of the oil-filled sealed helium scroll compressor of the present invention in a vertical structure. FIG.
FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 and FIG. 5 are a plan view and a longitudinal sectional view showing a part summary in which the stator 3a and the protector 91 of the present invention are combined. 6 and 7 show a longitudinal sectional view and a plan view of the hermetic terminal portion 37. Description will be made based on these examples. The scroll compressor parts 5 and 6 and the electric motor part 3 are accommodated in the hermetic container 1, and the scroll compressor part wraps the fixed scroll 5 and the orbiting scroll 6 for standing the spiral wrap on the disc-shaped end plate. Are engaged with each other, engaged with an eccentric mechanism that connects the orbiting scroll 6 to the rotary shaft 14, and the orbiting scroll 6 is orbited relative to the fixed scroll 5 without rotating. A discharge port 10 that opens and a suction port 15 that opens to the outer periphery are provided. Gas is sucked from the suction port 15 and moved around the compression chamber 8 formed by the scrolls 5 and 6 to reduce the volume. Compressed gas from the discharge port 10 is moved to the motor chamber 1b via the communication passage 18 in the container chamber 1a, and the sealed scroll pressure is discharged to the outside through the discharge pipe 20. It shows the machine structure. When the working gas is helium gas, an oil injection pipe 31 for cooling the working helium gas is passed through the sealed container 1 and connected to an oil injection port 22 provided in the end plate part 5a of the fixed scroll 5. An oil injection mechanism is provided. The injected oil discharged from the discharge port 10 becomes mist-like oil and flows into a mixture with helium gas, and moves from the container chamber 1a to the motor chamber 1b via the communication passage 18. become. A three-phase motor protector having a direct cut function at a motor coil end end 3e on the downstream side of the flow of the mixture and having a motor circuit energized by an abnormal increase in motor current and abnormal increase in gas temperature The means 91 is fixed to the upper end portion of the motor coil end with a plurality of tie straps 186 (186a, 186b; see FIG. 4) via the insulating sheet means 130. Thereby, the coil end part 3e and the protector means 91 are made into the integrated assembly method. The discharge gas flow path portion which is the main flow of the mixed flow of the gas flow and the mist-like oil mixture passes from the discharge chamber 1a to the motor chamber 1b1, the core through the communication passages 18a and 18b at the upper edge of the fixed scroll. Cut section passage 2
5b, because of the upward flow through the motor air gap passage 25g and then through the motor chamber 1b2, it further collides with the flow path leading from the core cut portion passage 25c to the discharge pipe 20 and the upper surface 3y of the stator 3a, so that the second hand in the circumferential direction The two flows are divided into two and reach the discharge pipe 20. The protector means 91 is attached to the motor coil end portion 3e serving as the joining position. In the motor protector means 91, the surface of the outer shell 91a is a charge exposed portion, and a plurality of lower end surfaces 91b of the protector means and an upper end surface part 3m of the motor coil end portion are provided via a thin film insulating sheet means 130. The tie strap 186 (insulating material) is fixed, and the motor coil end portion and the protector means are integrated. In FIG. 3, an arc-shaped gas flow path portion 25c is formed in the vicinity of the gas outlet of the discharge pipe 20 by the outer periphery of the motor stator and the inner wall surface of the sealed container, and engages with the gas flow path portion 25c. The example which installed the motor protector means 91 in the coil end edge part 3e is shown. With this structure, as shown in the figure, the flow of oil and gas is directly placed in the mixed flow around the protector, so that the forced cooling effect by the mixed flow can be greatly increased, and the temperature rise of the protector body can be increased. It can be suppressed. The protector 91 is bare with respect to the surrounding gas region. By this structure, since it exists in the flow area of the mixture of the surrounding gas flow and oil mist to a protector main-body part, a cooling function is improved greatly. There are three motor protector terminal portions 91P1, 91P2 and 91P3, and each connection terminal portion is connected to the neutral point lead wires 142, 143 and 144. Reference numeral 85 denotes a main power supply lead wire. In FIG. 3, the coil end inner diameter Dk is set so as to secure a necessary spatial distance L4 with respect to the chamber inner diameter Dci. 6 and 7 are a longitudinal sectional view and a plan view of the hermetic terminal portion 37, respectively. 372n is an insulator made of tempered glass. Reference numeral 37C denotes a sealing rubber portion, and reference numerals 37a, 37b, and 37c denote strap portions, which are main power connection portions to the outside of the compressor. The insulation space distance inside the compressor between the pin portion 372 (372a, 372b, 372c) serving as the connection portion of the hermetic terminal portion 37 and the main body portion 372m of the terminal portion 37 joined to the container 2b is L11 and L12 dimensions. For example, it is set to about 5 mm to 6 mm so as to satisfy UL984 of the US UL standard (standard for safety standards of hermetic compressors). Further, the creeping distance between the pin portion 372 and the main body portion 372m of the terminal portion 37 is similarly set to about 5 mm to 7 mm as in L15. As a safety standard for hermetic compressors, in the case of Japan, it is described in JIS standard JISC9335-2-34 (safety of electrical equipment), and the content conforms to the UL standard. In the case of FIG. 5, the arrangement set at the position on the inner side by the L2 dimension ensures a spatial distance corresponding to the dimension, and the spatial distance L4 between the protector outer surface and the container inner wall 2m is secured as the insulation distance. Is. Similarly, it arrange | positions so that the space distance L1 dimension of a protector outer surface part and the frame 7 inner wall part may be ensured as an insulation distance. Practically, the L4 dimension can be ensured to be equal to or greater than the insulation space distance (L11, L12 dimensions in FIG. 6) of the hermetic terminal part 37 with the main body part 372m, for example, around 5 mm to 7 mm. The insulation space distance around the conventional protector was about 2 mm and about 1/2 of the space distance of the hermetic terminal. When a high voltage is applied between the terminals, the discharge start voltage is set to a level of 1000 V at a distance of 1 mm in a general air atmosphere. In a He gas atmosphere, the dielectric strength value is low compared to other refrigerant gases (R22, R410a, air, etc.) due to the rare gas, so in the case of a small space distance, between the compressor body and the electrical system ground Has a unique problem that the leakage current flowing in is increased more than in the case of other refrigerant gases. The dimension L3 in FIG. 3 sets the size of the thin-film insulating sheet means 130 so as to ensure a creepage distance for insulation. As the electrical insulating sheet means 130, there is a polyester-based synthetic resin material (insulating sheet material) that is relatively soft and heat resistant. By placing the protector 91 at an inner position that is equal to or less than the coil end outer diameter Dk, the stator 3a integrated with the protector 91 is baked into the casing portion 2b as shown in FIG. At the time of press-fitting assembly by fitting, the protector 91 is not brought into contact with the axial positioning jig 890, and assemblability can be greatly improved. As shown in FIG. 11, in the conventional fixing method using a tight tie string with a hard insulating paper 89, there are some extra protrusions 89 a and 89 b at the end of the insulating paper, resulting in variations in coil forming dimensions. In the structure of the conventional motor 803, such as the occurrence of the protrusion and interference with the jig 890, the number of assembling steps increases and the mass productivity is difficult. Further, by adopting the configuration of the present invention, the speed of the main flow of gas can be set to about 1 to 3 m / sec, and the cooling effect of the present invention can be obtained more sufficiently. Conventional protectors have a flow rate of around 0.3 m / sec or less and have no cooling effect by gas. Further, since the protector is packaged inside the insulating paper in the prior art of FIG. 11, the heat generated by the protector is trapped inside, but the heat generated in the protector portion by this structure is positively applied to the motor chamber 1b1. It becomes possible to dissipate. By exposing it to the flow of the gas flow and oil mist mixture, a cooling effect by forced convection can be obtained directly, and the temperature rise of the motor protector body can be further suppressed. Promoting the cooling of the protector can increase the MCC value of the operating current as shown in FIG. Also, as shown in FIG. 12, by reducing the protector ambient temperature (protector body temperature), the number of ON / OFF lifespans of the contact part in the protector 91 body is extended, leading to an increase in capacity as a protector. Is. Here, taking the helium scroll compressor of FIG. 1 as an example, the flow of working helium gas and the flow of injected cooling oil will be described. In FIG. 1, an oil injection pipe 31 for cooling helium gas is connected to an oil injection port 22 provided in the end plate part 5a of the fixed scroll 5 through the upper lid 2a of the sealed container 1, The opening of the port 22 is opened facing the tooth tip surface of the wrap 6 b of the orbiting scroll 6. The scroll compression mechanism part is accommodated in the upper part which becomes the suction piping 17 side in the airtight container 1, and the motor part 3 is accommodated in the lower part. The sealed container 1 is partitioned into a motor chamber 1b with the discharge chamber 1a and the frame 7 interposed therebetween. The scroll compression mechanism unit forms a compression chamber (sealed space) 8 by meshing the fixed scroll 5 and the orbiting scroll 6 with each other. The fixed scroll 5 is composed of a disc-shaped end plate 5a and a wrap 5b formed in an upright involute curve or a curve approximate thereto, and is provided with a discharge 10 at the center and a suction port 15 at the outer periphery. ing. The orbiting scroll 6 is also composed of a disc-shaped end plate 6a, a wrap 6b standing upright and formed in the same shape as the fixed scroll wrap, and a boss portion 6c formed on the anti-wrap surface of the end plate. The frame 7 has a bearing portion 40 formed at the center thereof, and the rotating shaft 14 is supported on the bearing portion, and the eccentric shaft 14a at the tip of the rotating shaft is inserted into the boss portion 6c so as to be capable of turning. The fixed scroll 5 is fixed to the frame 7 by a plurality of bolts. The orbiting scroll 6 is supported on the frame 7 by an Oldham mechanism 38 including an Oldham ring and Oldham key. The orbiting scroll 6 does not rotate with respect to the fixed scroll 5. It is formed to make a swivel motion. An electric motor shaft 14b is integrally connected to the rotating shaft 14, and the motor unit 3 is directly connected thereto. A suction pipe 17 is connected to the suction port 15 of the fixed scroll 5 through the upper lid 2 a of the sealed container 1, and the discharge chamber 1 a in which the discharge 10 is opened passes through passages 18 a and 18 b on the outer edge of the frame 7. The motor chamber 1b (1b1, 1b2) communicates with the motor chamber 1b. The motor chamber 1b communicates with a discharge pipe 20 that penetrates the casing 2b at the center of the sealed container. The discharge pipe 20 is installed at a position almost opposite to the positions of the passages 18a and 18b. The positional relationship between the two 18 and 20 is such that the mixture of the gas and the injection oil that has passed through the passage 18 flows downward into the passage 25b in the vertical direction of the passage 18, the stator upper surface 3y, and the surrounding area. Due to the collision with the coil end portion 3g, it is divided into two hands in the horizontal direction and divided into two directions (strictly, three directions) along the flow path along the inner wall of the container. The motor chamber 1b is divided into an upper space 1b1 of the stator 3a and a lower space 1b2 of the stator 3a. Arc-shaped passages 25 (25a, 25b, 25c, 25d, which serve as gas flow paths between the motor stator 3a and the casing 2b inner wall surface 2m side so as to communicate the spaces 1b1 and 1b2 on both sides. 4). In the passage 25, mainly gas 25b, 25a, and 25d flow downward in the gas and the injection oil, and the working gas flows upward in the passage 25c only. Further, the gap 25g of the motor air gap also becomes a gas passage, and the space 1b1 and the space 1b2 communicate with each other through the gap 25g. According to the flow of the gas and oil mixture in the motor chambers 1b1 and 1b2 inside the container, the motor 91 is directly cooled by a relatively low temperature injection oil of 60 ° C. to 70 ° C. and the protector 91 body according to the present invention. Direct cooling to the part and the peripheral part is possible. In the space, the oil in the gas is separated from the gas and flows downward while cooling the surrounding members 3a, 2b, 7, and 14 via the passages 25a, 25b, and 25d. The scroll compressor for air conditioning and refrigeration applications does not have an oil injection structure, so the cooling effect of this oil cannot be obtained. An O-ring 53 that seals the high-pressure part and the low-pressure part is provided between the suction pipe 17b and the fixed scroll 5. Further, 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 of the orbiting scroll 6. An intermediate pressure Pb between the suction pressure and the discharge pressure is introduced through the bored hole 6d, and an axial application force for pressing the orbiting scroll 6 against the fixed scroll 5 is applied. The lubricating oil 23 is stored at the bottom of the sealed container 1, and the lubricating oil 23 is sucked up to the oil suction pipe 27 by the differential pressure between the high pressure in the sealed container and the intermediate pressure Pb in the back pressure chamber 36. Then, the oil flows through the rotary shaft 14 and is supplied to the auxiliary bearing 39 and the main bearing 40 through the slewing bearing 32 and the lateral hole 51. Oil supplied to the bearing portions 40 and 32 is injected into the compression chamber 8 of the scroll wrap through the hole 6d through the back pressure chamber 36, mixed with the compressed gas, and then discharged into the discharge chamber 1a together with helium gas. . An oil take-out pipe 30 for taking out the lubricating oil 23 at the bottom is provided at the bottom of the sealed container 1.

FIG. 8 is an embodiment of a lubrication system diagram showing an embodiment of the helium hermetic scroll compressor 100 of the present invention. As shown in FIG. 8, the lubricating oil 23 stored in the bottom of the sealed container 1 is a differential pressure between the pressure in the sealed container 1 (discharge pressure Pd) and the pressure in the compression chamber 8 (pressure less than the discharge pressure). Accordingly, the oil flows into the oil take-out pipe 30 from the inflow portion 30a of the oil take-out pipe 30. The oil that has flowed into the oil take-out pipe 30 reaches the oil cooler 33 through the external oil pipe 51 and is appropriately cooled here, and then is passed through the oil injection pipe 31 and the port 22 via the oil pipes 36a and 36b. The pressure is introduced and injected into the compression chamber 8. Reference numeral 271 denotes an oil flow rate adjusting valve. 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 to the discharge chamber 1a. The protector 91 is directly cooled in the motor chamber 1b and separated from the working gas in the same manner as described above, and the passages 25a and 2 are separated.
It flows down through 5b and 25d and accumulates at the bottom of the sealed container 1. In the case of FIG. 8, the spatial distance L8 between the outer surface portion of the protector 91 and the container inner wall portion 2m, and the spatial distance L9 between the outer surface portion of the protector 91 and the inner wall portion of the frame 7 are the spatial distances of the above-mentioned Herme terminal portions. Arrange them so that they are at least as secure as.

Next, a motor circuit diagram is shown in FIG. Although the protector 91 shows an example for three phases, it is also within the scope of the present invention to apply a single-phase protector means. Neutral point 3 for star connection
k is a circuit equipped with an internal motor protector 91. Two contact parts 351p and 351n (current interrupting parts) are configured in the protector 91 for the three phases, and with this configuration, a motor circuit that energizes the motor coil due to an abnormal increase in motor current and abnormal increase in gas temperature is directly provided. A three-phase motor protector having a cutting function is shown. For this reason,
The contact portion is always closed. It opens at the time of abnormality. 91p1, 91p2 and 91p3 are protector pin portions. 3e is a motor coil part. Reference numeral 37 denotes a hermetic terminal.

FIG. 10 is a motor protector characteristic diagram showing the relationship between the operating current passing through the protector and the ambient temperature around the protector. By lowering the ambient temperature of the protector 91 (denoted as Tp), and thus lowering the discharge gas temperature (denoted as Td) flowing out from the discharge pipe 20,
The operating current of the protector can be increased. Usually, Td <Tp, and the conventional machine (for air conditioning use) has a temperature difference of Tp−Td = 20 to 30 ° C. under an overload condition. In the scroll compressor for helium of the present invention, the temperature difference can be reduced to Tp−Td = 10 to 15 ° C. by the oil injection effect. As a result, the motor protection function of the protector 91 can be improved. Further, the oil injection cooling amount is adjusted by the oil flow rate adjusting valve 271 (FIG. 8) so that Tp−Td = 10 to 15 ° C. The operation and effect of the present invention will be described with reference to FIG. The X mark and the operation point (a) in the operation diagram are for the case where the insulating sleeve shown in FIG. 11 wraps the protector body, and with respect to the operation point (b) of the individual characteristics of the protector (no gas flow). Thus, the temperature range becomes low, and the motor circuit is shut off at a relatively low Tp temperature. This is a result of a difference between the ambient temperature Tp and the actual temperature of the protector body. On the other hand, the operating characteristic (circle) and the operating point (C) of the present invention indicate that the system operates to a higher ambient temperature than the conventional machine due to the cooling effect. At the protector ambient temperature TP2, the operating current of the conventional machine that was A0, A1 can be increased to the operating current A2 according to the present invention. When this operating current becomes high, the operating range of the compressor, particularly the upper limit value of the discharge pressure, can be increased, and the operating range is widened. FIG. 12 shows that the lifetime of the protector is increased by lowering the protector temperature by about 20 ° C. due to the cooling effect in the present invention, compared to the conventional technique in which the protector ambient temperature is increased. Thus, by lowering the surface temperature of the protector of the present invention and arranging it at the optimum position of the present invention, it is possible to obtain a significant increase function of the operating current, and thereby the upper limit of the operating range of the compressor. The overload condition can be increased. With the oil injection described above, the protector's ambient temperature can be lowered than that for air conditioning applications. When an overcurrent flows, the temperature of the protector contact portion (eg, 351p in FIG. 9) decreases, and the number of contact ON / OFF times is reduced. The effect of increasing the total number of times is obtained. As the structure of the contact portion, there is a bimetal structure (not shown). That is, the effect of improving the life of the protector can be obtained. The motor protector 91 is an automatic return type in which, when the ambient temperature returns to normal, the contact is closed and current flows again to the circuit by the bimetal structure.

FIG. 13 is an example showing the relationship between the in-vessel helium gas operating pressure and the leakage current. When the helium gas itself is a rare gas and the operating pressure is low, the leakage current greatly increases with the operating voltage of the compressor. Helium gas has a problem inherent to helium gas that has a lower dielectric strength value (unit: kV / cm) than the case of the air conditioning refrigerant R22. For this reason, in order to reduce the leakage current during operation, This is to secure a larger distance. FIG. 13 shows that the high-pressure chamber structure is advantageous in that it has a lower leakage current than the low-pressure chamber structure. FIG. 14 shows the relationship between the amount of moisture in the helium gas in the container and the leakage current. It has been found that the leakage current of the compressor greatly increases when the amount of water in the helium gas is high. From this relationship, in order to reduce leakage current, in the present invention, the high-purity helium gas is practically composed of components whose water content in the helium gas is 0.5 ppm or less and whose purity is 99.9999% or more. It is characterized by using.

FIG. 15 shows an embodiment of the refrigeration / air-conditioning scroll compressor 200 that does not require the oil injection mechanism sections 30 and 31. In the air-conditioning scroll compressor 200 that does not have an oil injection mechanism, as shown in FIG. 15, the protector 91 having the insulating means 130 is tied to the coil end 3e and attached with the string 86, as shown in FIG. According to the above, the same operation and effect as described above can be obtained.

The above description has been made by taking an example of the high pressure chamber structure in which the sealed container has a discharge pressure atmosphere. However, the present invention can also be applied to the scroll compressor 300 having a low pressure chamber structure in which the sealed container has an intake pressure atmosphere. The range is included, and an example thereof is shown in FIG. The scroll compressor unit and the electric motor unit are housed in the hermetic container 202, and the scroll compressor unit has the fixed scroll 612 and the orbiting scroll 610 with the spiral wrap standing upright on the disc-shaped end plate so that the wraps are inside each other. The rotating scroll is engaged with an eccentric mechanism connected to the rotary shaft 515, and the rotating scroll is rotated with respect to the fixed scroll without rotating. The fixed scroll has an outlet 109 and an outer peripheral portion that are open at the center. Suction port 5
18, the suction port 518 sucks low-pressure refrigerant gas from the motor chamber (low pressure chamber) 512 below the frame 387 through the communication path 516, sucks gas from the suction port 518, The gas is compressed by moving around the formed compression chamber to reduce the volume. Reference numeral 510 denotes an intake pipe. Reference numeral 550 denotes a discharge pipe, and reference numeral 543 denotes a sealing O-ring. 519 is an oil supply hole, and the oil supplied through the hole reaches the chamber 303 through the bearing portions 32 and 40. The hole 325 is a discharge oil hole for returning the oil accumulated in the chamber 303 to the low pressure chamber 512 and the compressor. The compressed refrigerant gas is discharged from the discharge port 109 to the outside through the discharge pipe 550. A three-phase motor protector means having a direct cut function for a motor circuit in the motor chamber 512 that energizes a motor coil due to an abnormal increase in motor current and an abnormal increase in gas temperature in a gas flow path portion that is the main flow of refrigerant gas. 91 is fixed to the upper end portion 3e of the motor coil end with a tie cord 86 through an insulating sheet means 130, and the frame 387 of the compressor internal member facing the protector main body portion 91a and the inner wall portion 202m of the sealed container The insulation space distances L22 and L21 are ensured to be equal to or greater than the insulation space distance L12 of the power supply hermetic terminal portion 37.

FIG. 17 is a longitudinal sectional view showing an embodiment of the vertical rotary type air-conditioning hermetic compressor of the present invention. 18 is a cross-sectional view taken along the line FF of FIG. 17, and FIG. 19 shows another embodiment of FIG. FIG. 20 is a longitudinal sectional view around the hermetic terminal portion 377 shown in FIG. In FIG. 17, a stationary member 805, a piston portion 806, and an electric motor portion 803 serving as a rotary compressor portion are housed in an airtight container 801. A suction pipe 817 that opens to the outer periphery is provided, gas is sucked from the suction pipe 817, the volume is reduced in the compression chamber 808 formed by the compressor mechanism portions 805 and 806, and the gas is compressed. A sealed rotary compressor structure is shown in which compressed gas is moved to a motor chamber 801b1 via a passage 818, and is further moved to the motor chamber 801b2 via a motor core cut portion 825, and further gas is discharged outside the apparatus. The three-phase motor protector means 91 is located at the upper end of the coil end 803e of the motor 803, and the outer surface 91a of the protector 91 main body is a charge exposed portion, and as shown in FIG. The insulation space distances L18 and L44 between the member 802a and the inner wall portion 802m, which are fixed with a tie strap 186 (not shown here) and are opposed to the protector body 91a, are insulated from the power supply hermetic terminal portion 377. It is secured at least equal to the spatial distances L12 and L11. In FIG. 17, the coil end inner diameter Dk is set so as to ensure a necessary spatial distance L44 with respect to the chamber inner diameter Dc2. In FIG. 18, the dimension L33 sets the size of the thin-film insulating sheet means 130 so as to secure a necessary creepage distance for insulation.

FIG. 19 is a plan view showing a component assembly diagram in which the stator 803a, the protector 91, and the container member 802b are combined. The passage 825 (825a, 825b, 825c, 825)
As shown in the gas flow direction, the upward gas flow flowing out from d) flows around the protector and exits to the outside through the discharge pipe 820. FIG. 19 shows that the motor protector means 91 is located at the upper end of the motor coil end 3e and has a motor core cut portion 825c serving as a gas flow path portion.
It is the example arrange | positioned in the position engaged with the side. Thereby, a gas flow will be directly exposed to a protector main-body part, and a forced cooling effect | action can be exhibited further, and the temperature of a protector main body can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing one embodiment of a vertical type helium hermetic scroll compressor of the present invention. AA sectional drawing of FIG. BB sectional drawing of FIG. The top view which shows the components summary which combined the stator 3a and protector 91 of this invention. The longitudinal cross-sectional view which shows the components summary which combined the stator 3a and protector 91 of this invention. The longitudinal cross-sectional view of the Herme terminal part 37. FIG. The top view of the Herme terminal part 37. FIG. The Example of the oil supply system figure which shows the oil injection piping path | route which has arrange | positioned one Example of the hermetic scroll compressor for helium of this invention. Motor circuit diagram. Explanatory drawing which shows the effect | action and effect of this invention. The stator external view of a prior art. Explanatory drawing which shows the effect | action and effect of this invention. Explanatory drawing which shows the effect | action and effect of this invention. Explanatory drawing which shows the effect | action and effect of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing one embodiment of a vertical type airtight hermetic scroll compressor of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an embodiment of an airtight hermetic scroll compressor having a low-pressure chamber structure according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an embodiment of a vertical rotary type air-conditioning hermetic compressor of the present invention. FF sectional drawing of FIG. FIG. 19 shows another embodiment of FIG. FIG. 18 is a longitudinal sectional view around the hermetic terminal portion 377 shown in FIG. 17.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,801 ... Sealed container, 1a, 801a ... Discharge chamber, 1b, 1b1, 1b2, 801b1, 801b2 ... Motor chamber, 2,802 ... Container member, 3,803 ... Electric motor part, 3a ... Motor stator, 3b ... Motor rotor, 3c: Discharge pipe side motor coil end portion, 3g: Motor coil end portion on the passage 18 side, 5 ... Fixed scroll, 6 ... Orbiting scroll, 7 ... Frame, 8,808 ... Compression chamber, 9,809 ... Balance weight, 10 , 810 ... Discharge port, 15 ... Suction port, 818 ... Passage, 14,814 ... Rotating shaft, 14a ... Eccentric shaft, 17,817 ... Suction pipe, 18a, 18b ... Passage, 20, 820 ... Discharge pipe, 22 ... Port , 23 ... Lubricating oil, 25, 825 ... Passage, 30 ... Oil take-out pipe, 31 ... Oil injection pipe, 32 ... Slewing bearing, 36 ... Oldham mechanism, 39 ... Auxiliary bearing , 40 ... main bearing, 85, 885 ... lead wire for main power supply, 86 ... tie string, 88, 91 ... motor protector, 89 ... insulating paper, 130 ... thin-film insulating sheet means, 142, 143, 144 ... neutral point Lead wire.

Claims (5)

  In a hermetic compressor in which a compressor unit and an electric motor unit are housed in a hermetic container, a motor protector means having a direct cut function for a motor circuit that energizes a motor coil due to an abnormal increase in motor current and abnormal increase in gas temperature. At the upper end of the coil end, the outer surface of the protector main body is a charge exposed portion, and is fixed with a tie through an insulating sheet means, and the compressor internal member and the airtight container facing the protector main body A hermetic compressor characterized in that an insulation space distance with the inner wall portion is secured to be equal to or greater than an insulation space distance of a hermetic terminal for power supply. In the sealed container, the scroll compressor unit and the electric motor unit are housed, and the scroll compressor unit meshes the fixed scroll and the orbiting scroll with the spiral wrap upright on the disc-shaped end plate with the wraps inside each other, The orbiting scroll is engaged with an eccentric mechanism connected to the rotating shaft, and the orbiting scroll is caused to orbit with respect to the fixed scroll without rotating. The fixed scroll has an outlet opening at the center and an inlet opening at the outer periphery. In a hermetic scroll compressor that compresses gas by reducing the volume by sucking gas from the suction port and moving it around the compression chamber formed by both scrolls,
A motor protector having a direct cut function is provided at the upper end portion of the motor coil end, and a motor circuit that energizes the motor coil due to an abnormal increase in motor current and an abnormal increase in gas temperature in the gas flow path portion that is the main flow of refrigerant gas, The outer surface of the protector main body is a charge exposed portion, and is fixed with a tie string through an insulating sheet means, and the insulation space distance between the compressor internal member and the inner wall of the sealed container facing the protector main body is A hermetic scroll compressor characterized in that it is secured at least equal to the insulation space distance of the hermetic terminal for power supply.   The working gas is helium gas, and the scroll compressor unit and the electric motor unit are housed in a sealed container. The scroll compressor unit includes a fixed scroll and an orbiting scroll for standing a spiral wrap on a disc-shaped end plate. The wraps are meshed with each other, engaged with an eccentric mechanism that connects the orbiting scroll to the rotating shaft, and the orbiting scroll is orbited with respect to the fixed scroll without rotating. A hermetic scroll compressor that compresses gas by reducing the volume by sucking gas from the suction port and moving the suction chamber formed by both scrolls to the center. The oil injection port provided in the end plate portion of the fixed scroll passes through the hermetic container through the oil injection pipe for cooling the working helium gas. In a sealed helium scroll compressor having a continuous oil injection mechanism, at the end of the motor coil end that is downstream of the flow of the mixture of mist oil and refrigerant gas discharged from the discharge port. A motor circuit that energizes the motor coil due to an abnormal increase in motor current and an abnormal increase in gas temperature has a motor protector means having a direct cut function at the upper end of the motor coil end, and the outer surface of the protector main body is exposed to charge. It is fixed with a tie through an insulating sheet means, and the insulation space distance between the frame member facing the protector body and the inner wall of the sealed container is equal to or greater than the insulation space distance of the hermetic terminal for power supply A helium-enclosed scroll compressor characterized in that the protector is disposed at a position secured in the helium.   The said motor protector means exists in the upper end surface part of a motor coil end part, and the attachment position of this protector is arrange | positioned in the inner position below equivalent to a coil end outer diameter. Item 6. The hermetic compressor according to item 3.   4. The working gas is helium gas, and the helium gas having a water content of 0.5 ppm or less and a purity of helium gas of 99.9999% or more is used. Sealed scroll compressor for helium.

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