JP5279324B2 - Helium hermetic scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress pressure pulsation of a suction pipe line; to reduce oil stirring loss in a suction chamber; to reduce pressure loss in a discharge passage; to suppress discharge pressure pulsation; and to reduce flow resistance loss power, in a hermetic scroll compressor for helium. <P>SOLUTION: When a turning outside compression chamber 8a becomes maximum suction volume, a lap outer peripheral surface at a lap winding finish end part of a turning scroll 6 and a lap inner peripheral surface of a fixed scroll 5 are brought into contact with each other at a first contact position. When a turning inside compression chamber 8b becomes maximum suction volume, a lap inner peripheral surface at a lap winding finish end part of the turning scroll 6 and a lap outer peripheral surface of the fixed scroll 5 are brought into contact with each other at a second contact position. A winding angle of the first contact position of the fixed scroll 5 is extended by a prescribed angle in relation to a winding angle of the second contact position of the fixed scroll 5. A winding angle of the first contact position of the turning scroll 6 and a winding angle of the second contact position of the turning scroll 6 coincide with the winding angle of the first contact position of the fixed scroll 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a scroll compressor for helium.

  The helium-enclosed scroll compressor uses helium gas as the working gas, and stores the compressor unit and the electric motor unit that drives the compressor unit vertically in the hermetic container, and oil injection that penetrates the hermetic container Constructed by connecting a tube to the compressor section. The compressor unit forms a compression chamber by meshing a fixed scroll and an orbiting scroll that stand up a spiral wrap on a disc-shaped end plate with the wraps inside each other, and moves the compression chamber as a center to increase the volume. By reducing, the compressed helium gas is discharged into the sealed container. The oil supplied to the compressor part via the oil injection pipe cools the helium gas and lubricates the sliding part of the scroll constituting the compressor part. This oil is discharged together with helium gas from the compressor section and stored in the bottom of the sealed container. After being extracted from the bottom by the oil injection mechanism, the oil is cooled and returned to the sealed container through the oil injection pipe. It is injected into the machine part.

  As an example in which a sealed scroll compressor for helium (hereinafter, abbreviated as a compressor as appropriate) configured as described above is used in a refrigeration system, for example, Japanese Patent Application Laid-Open No. 2004-232481 (Patent Document 1) is disclosed. ing. This refrigeration system has a refrigeration circuit formed by connecting a compressor and a refrigerator with two pipes, and an oil injection circuit that extracts oil from the compressor by an oil injection mechanism, cools it, and returns it to the compressor again. Is provided. Here, helium gas is used as a working refrigerant in the refrigeration circuit.

JP 2004-232481 A

  According to the conventional compressor including Patent Document 1, the volume is maximized when the suction of the two symmetrical compression chambers formed in the scroll compressor, that is, the swirling outer compression chamber and the swirling inner compression chamber, which will be described later, is completed. The timing is set to be the same, and the discharge start timing is set to be the same at the time of discharge in the turning outer compression chamber and the turning inner compression chamber.

  FIG. 16 shows the relationship between the suction volume of these two compression chambers and the rotation angle of the crankshaft for turning the orbiting scroll. Here, Vths indicates the suction volume of the orbiting outer compression chamber formed by being surrounded by the outer peripheral surface of the orbiting scroll wrap and the inner peripheral surface of the fixed scroll, and Vthk is the inner peripheral surface of the orbiting scroll and the fixed scroll. The suction | inhalation volume of the rotation inner side compression chamber formed so that it may be enclosed with the outer peripheral surface of lap | wrap of this may be shown.

  As shown in FIG. 16, when the suction of the swirling outer compression chamber with the suction volume Vths and the swirling inner compression chamber with the suction volume Vthk are completed, both are point C, and the rotation angles thereof are the same. That is, the volumes Vths and Vthk of the compression chambers change as indicated by dotted lines, and the total volume Vths + Vthk of the compression chambers becomes a point D that is twice the volumes Vths and Vthk of the point C as indicated by the solid lines. Therefore, the suction of helium gas is temporarily stopped in the suction line, and a large pressure fluctuation occurs due to an impact phenomenon that accompanies the instantaneous stop of the flow of helium gas and oil. In addition, the reciprocating motion of the displacer unit during the expansion stroke on the refrigerator side may promote fluctuations in the suction pressure.

  In this way, when a large fluctuation occurs in the suction pressure, in the configuration in which the suction gas flows directly into the compressor section, a large fluctuation occurs in the compression torque, resulting in abnormal vibration of the Oldham mechanism and the like and a reduction in the life of the compressor. Therefore, reliability may be adversely affected. In order to solve this problem, conventionally, a surge tank or the like having a function of reducing or suppressing fluctuations in suction pressure is installed in the suction piping line connecting the refrigerant outlet side of the refrigerator and the inlet side of the compressor. Yes. However, providing such equipment increases the volume and weight of the entire unit as a refrigeration system, which is disadvantageous in terms of manufacturing costs.

  On the other hand, in the conventional refrigeration system, the high-pressure gas discharged from the compressor is led to a gas cooler to separate the oil, and the separated oil is led to a suction pipe line and is sent to the compressor together with helium gas. Supplied. In such a case, the oil returned to the compressor is likely to accumulate in the suction chamber of the compression unit, and this oil causes a stirring loss in the orbiting motion of the outer peripheral portion of the orbiting scroll wrap, thereby degrading the performance of the compressor. There is.

  FIG. 17 shows the relationship between the internal pressure of the turning outer compression chamber and the turning inner compression chamber and the rotation angle of the crankshaft. Here, Pis indicates the internal pressure of the orbiting outer compression chamber, and Pik indicates the internal pressure of the orbiting inner compression chamber.

  As shown in FIG. 17, the internal pressure Pis of the orbiting outer compression chamber changes as indicated by a one-dot chain line, and the inner pressure Pik of the orbiting inner compression chamber changes as indicated by a solid line. The discharge start timings of the orbiting outer compression chamber and the orbiting inner compression chamber are both at point E, and the rotation angles thereof coincide. As a result, there is a problem that the pressure loss increases due to the narrowing of the discharge passage and the large amount of oil flow at the start of discharge, the increase in discharge pressure pulsation, and the flow resistance loss power greatly increase.

  An object of the present invention is to suppress pressure pulsation in the suction piping line and reduce oil agitation loss in the suction chamber, and to reduce pressure loss in the discharge passage, suppression of discharge pressure pulsation, and reduction of flow resistance loss power. The object is to obtain a sealed scroll compressor for helium that can be used.

In order to achieve the above-mentioned object, in the present invention, helium gas is used as a working gas, and a scroll compressor part and an electric motor part for driving the scroll compressor part are housed and arranged in a sealed container, The scroll compressor unit has a fixed scroll in which a spiral wrap is provided upright on a disk-shaped end plate and a revolving scroll in which a spiral wrap is provided upright on a disk-shaped end plate with these wraps being inside each other. Engaging the orbiting scroll with the eccentric part of the crankshaft, causing the orbiting scroll to orbit with respect to the fixed scroll without rotating. A compression chamber formed by the two scrolls. The helium gas is compressed by moving to the heart and reducing the volume, and the compressed helium gas is discharged from the discharge port, and the oil injection pipe that guides oil for cooling the helium gas is sealed. In the helium hermetic scroll compressor provided with an oil injection mechanism portion that penetrates the container and is connected to an oil injection port provided in the end plate portion of the fixed scroll, the outer peripheral surface of the wrap on the winding end side of the orbiting scroll And a wrap outer peripheral surface of the orbiting scroll and a wrap inner periphery of the fixed scroll when the orbiting outer compression chamber formed by being surrounded by the wrap inner peripheral surface of the fixed scroll has a maximum suction volume. The surface is in contact with the first contact position, and is surrounded by the inner peripheral surface of the orbiting scroll and the outer peripheral surface of the fixed scroll. When the orbiting inner compression chamber has the maximum suction volume, the inner peripheral surface of the wrap winding end of the orbiting scroll and the outer peripheral surface of the fixed scroll come into contact with each other at a second contact position, and the fixed scroll The winding angle of the first contact position of the fixed scroll is extended by a predetermined angle with respect to the winding angle of the second contact position of the fixed scroll, and the winding angle is larger than the arc radius of the tip portion that becomes the winding start portion of the fixed scroll. The arc radius of the tip portion that becomes the winding start portion of the orbiting scroll is set to be large, and the arc radius of the tip portion that becomes the winding start portion of the fixed scroll is set to Rk1, and the tip portion that becomes the winding start portion of the orbiting scroll is When the arc radius is represented as Rs1,
Rs1 / Rk1 = 1.4 to 1.6
The arc radius of each of the fixed scroll winding start portion and the orbiting scroll winding start portion is set so as to be within the range, and the discharge start timing of the orbiting outer compression chamber and the discharge start of the orbiting inner compression chamber are set. The timing is shifted from 1 / 3π rad to 1 / 2π rad so that the discharge flow timing and phase of the working gas and oil in the swirling outer compression chamber and the swirling inner compression chamber are shifted .

A more preferable specific configuration example of the present invention is as follows.
(1) With respect to the opening of the oil injection port at the completion of the suction, which is the timing of forming the maximum sealed volume of the orbiting inner compression chamber formed by the inner curve of the orbiting scroll and the outer curve of the fixed scroll wherein as lap addendum portion of the orbiting scroll is positioned substantially at the center position, to the provision of the oil injection port substantially in the center position of the tooth space of the fixed scroll Te.
(2) When one of the swirl outer compression chamber and the swirl inner compression chamber reaches a maximum volume, the opening of the oil injection port communicates with both the swirl outer compression chamber and the swirl inner compression chamber. The oil injection port.

  According to the sealed scroll compressor for helium of the present invention, the pressure pulsation of the suction pipe line is suppressed and the oil stirring loss in the suction chamber is reduced, the pressure loss in the discharge passage is reduced, the discharge pressure pulsation is suppressed, It is possible to reduce the flow resistance loss power.

  Hereinafter, a sealed scroll compressor for helium according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is an overall configuration diagram of a refrigeration apparatus including a sealed scroll compressor for helium according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an external appearance of the compressor unit of FIG.

  The refrigeration apparatus 300 according to this embodiment includes a vertical type helium-enclosed scroll compressor 100 (hereinafter, abbreviated as a compressor 100 as appropriate) and a refrigerator 110. The compressor 100 and the refrigerator 110 constitute a refrigeration cycle 140 that circulates a working refrigerant by being connected via pipes 120 and 130. In the refrigeration cycle 140, a gas cooler 150, an oil separator 160, and an oil adsorber 170 are disposed. In addition, a pipe 180 that bypasses the oil adsorber 170 and the refrigerator 110 from the oil separator 160 and returns the oil to the compressor 100 is provided. Helium gas is used as a working refrigerant for such a refrigeration cycle 140.

  On the other hand, the compressor 100 is provided with an oil injection circuit 190 for extracting the lubricating oil in the compressor 100 to the outside, cooling it, and returning it to the compressor 100 for circulation. The oil injection circuit 190 includes an oil cooler 200 and an oil flow rate adjustment valve 210, and these are connected by pipes 220 and 230. The oil injection circuit 190 includes an oil take-out pipe 30 that communicates with the lubricating oil 23 (see FIG. 3) accumulated at the bottom of the compressor 100, and an oil injection pipe that communicates with the compression chamber 8 (see FIG. 3) of the compressor 100. 31.

  The above-described devices constituting the refrigeration apparatus 300 are accommodated in a compressor unit 240 indicated by a one-dot chain line in FIG. These devices are arranged and housed in the compressor unit 240 as shown in FIG. The solid line in the figure represents the flow direction of helium gas, and the dotted line represents the flow direction of oil.

  The lubricating oil 23 stored at the bottom of the sealed container 1 is taken out from the oil take-out pipe 30 due to the pressure difference in the sealed container 1 and led to the oil cooler 200 through the pipe 220, where it is drawn by the external air. After cooling, an oil piping path is formed that reaches the oil injection pipe 31 through the oil flow rate adjusting valve 210 and the piping 230. The oil in the oil injection pipe 31 is returned to the compressor 100 through the oil injection port 22 (see FIG. 3).

  On the other hand, the helium gas discharged from the compressor 100 through the discharge pipe 20 flows into the gas cooler 150 through the pipe 310, is cooled here, and is guided to the oil separator 160 through the pipe 320. Here, the helium gas from which the oil has been separated to some extent is introduced into the oil adsorber 170 via the pipe 330 and further separated into the oil, and then introduced into the refrigerator 110 via the pipe 130. The helium gas introduced into the refrigerator 110 is adiabatically expanded inside to generate a cold heat source. The helium gas discharged from the refrigerator 110 passes through the pipe 120 and the suction pipe 340 and is directly returned to the compressor 100 as a normal temperature suction gas. Here, a pipe 180 is connected to the suction pipe 340 so that the oil separated by the oil separator 160 is returned.

  The refrigeration apparatus 300 according to the present embodiment absorbs a large pressure pulsation generated on the compressor side and the chiller side across the suction piping system, and can greatly reduce this. Further, conventionally, for example, a surge tank installed on the suction pipe 340 is not required, and the refrigerator 110 and the compressor 100 can be directly connected by a pipe.

  In FIG. 2, the compressor unit 240 is formed of a substantially rectangular casing having outer dimensions of a lateral width L1, a depth L2, and a height L3, and a caster 410 is provided at the bottom of the casing so as to be movable. It has become. Further, a ventilation port (louver part) 400 is provided on the front surface or the side surface for ventilation of a cooling fan provided inside. The external dimensions of the compressor unit 240 can be reduced by three because no surge tank is required. In addition, L4 shows the height dimension of a caster part.

  Next, the configuration of the compressor 100, which is a main part of the compressor unit 240, will be described in detail with reference to FIGS. 3 is a longitudinal sectional view showing the overall configuration of the compressor of FIG. 1, FIG. 4 is a plan view of the fixed scroll of FIG. 3, FIG. 5 is a longitudinal sectional view of the fixed scroll of FIG. 4, and FIG. FIG. 7 is a longitudinal sectional view of the orbiting scroll of FIG. 6, FIG. 8 is a plan sectional view showing a state in which the fixed scroll and the orbiting scroll of FIG. 3 are combined, and FIG. FIG. 10 is a diagram for explaining the relationship between the suction volume and the crankshaft rotation angle of the orbiting outer compression chamber and the orbiting inner compression chamber in the present embodiment.

  First, the overall configuration of the compressor 100 will be described with reference to FIG. The compressor 100 stores a scroll compressor unit 4 and a motor unit 3 serving as an electric motor in a vertically long sealed container 1 in an up-down direction. The sealed container 1 is configured by combining an upper lid 2a, a cylindrical body portion 2b, and a bottom portion 2c. The scroll compressor unit 4 forms a compression chamber 8 serving as a sealed space 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 an approximate curve thereto, and has a discharge port 10 at the center and a suction port 15 at the outer periphery. I have. The suction port 15 includes a first suction port 15a that communicates with the suction pipe 17 and a second suction port 15b that communicates with the suction port 5a.

  The orbiting scroll 6 includes a disc-shaped end plate 6a, a wrap 6b that stands upright and is formed in the same shape as the fixed scroll wrap 5b, and a boss portion 6c that is formed on the anti-wrap surface of the end plate 6a. ing. The frame 7 forms a main bearing 40 at the center, and the crankshaft 14 is supported by the main bearing 40, and the eccentric shaft 14a at the tip of the crankshaft 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 comprising an Oldham ring and an Oldham key, and is formed so as to perform an orbiting motion without rotating with respect to the fixed scroll 5. A motor shaft 14 b is integrally connected to the crankshaft 14, and the motor shaft 14 b is directly connected to the motor unit 3.

  An oil injection pipe 31 for supplying oil for cooling the 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 hermetic container 1, and this oil injection pipe The opening of the port 22 is opened facing the tooth tip surface of the wrap 6 b of the orbiting scroll 6. A suction pipe 17 for sucking helium gas into the sealed container 1 passes through the upper lid 2 a of the sealed container 1 and is connected to the suction port 15 of the fixed scroll 5. Both the oil injection pipe 31 and the suction pipe 17 have an elbow structure. The distal end portion 17c of the suction pipe 17 becomes an expanded portion into which a copper pipe can be inserted, and brazing connection is possible.

  Inside the hermetic container 1, a discharge chamber 1 a in which a discharge port 10 of the fixed scroll 5 is opened and a motor chamber 1 b are divided into upper and lower portions by a frame 7. The discharge chamber 1a communicates with the motor chamber 1b via the fixed scroll 5 and the first passages 18a and 18b at the outer edge of the frame 7, and the motor chamber 1b communicates with the discharge pipe 20 penetrating the trunk portion 2b of the sealed container 1. ing.

  The discharge pipe 20 is installed at a position almost opposite to the positions of the first flow paths 18a and 18b. The motor chamber 1b is divided into an upper space 1b1 of the stator 3a and a lower space 1b2 of the stator 3a, and an oil is provided between the stator 3a and the inner wall surface 2m of the body portion 2b so as to communicate the spaces 1b1 and 1b2. And passages 25b and 25c serving as gas flow paths are formed. Further, a gap 25g of the motor air gap also serves as a passage, and the upper space 1b1 and the lower space 1b2 are communicated with each other through the gap 25g. A balance weight 9a and a sub balance weight 9b are provided on the crankshaft 14 and the rotor 3b in order to cancel out the centrifugal force generated by the turning motion of the turning scroll 6.

  By such a flow of the gas and oil mixture in the spaces 1b1 and 1b2 inside the container, it is possible to directly cool the motor unit 3 with, for example, a relatively low temperature injection oil of 60C to 70 ° C. The oil in the gas is separated from the gas in the upper space 1b1 and flows down while cooling the surrounding members 3h, 3g, 2b, 7, and 14 via the lower second passage 25b. Since scroll compressors for air conditioning and refrigeration applications do not have such an oil injection structure, a cooling effect by oil cannot be obtained. 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 space 36 (hereinafter referred to as an intermediate pressure chamber 36) surrounded by the scroll compressor unit 4 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 suction pressure and discharge pressure is introduced into the intermediate pressure chamber 36 through an intermediate pressure hole 6 d that penetrates the end plate 6 a of the orbiting scroll 6, and an axially applied force that presses the orbiting scroll 6 against the fixed scroll 5. Is given.

  The oil separated from the gas is stored as lubricating oil 23 at the bottom of the sealed container 1 and is sucked up to the oil suction pipe 27 by the difference between the high pressure in the sealed container 1 and the intermediate pressure in the intermediate pressure chamber 36. After that, the central hole 13 in the crankshaft 14 is raised and supplied to the auxiliary bearing 39 and the main bearing 40 through the slewing bearing 32 and the lateral hole 51. The lubricating oil 23 supplied to the main bearing 40 and the slewing bearing 32 is injected into the compression chamber 8 formed by the scroll wrap through the intermediate pressure chamber 36 and the intermediate pressure hole 6d, where it is mixed with the compressed gas, and then together with the helium gas. It is discharged into the discharge chamber 1a. An oil take-out pipe 30 for taking out the lubricating oil 23 to the outside is provided at the bottom of the sealed container 1. A forming prevention oil plate 47 is provided on the surface of the lubricating oil 23 stored at the bottom of the sealed container 1 to prevent the forming phenomenon of the lubricating oil 23 that occurs when the compressor 100 is started. ing.

  The lubricating oil 23 stored at the bottom of the sealed container 1 is caused by a differential pressure between the pressure in the sealed container 1 (the same pressure as the discharge pressure) and the pressure in the compression chamber 8 (a pressure lower than the discharge pressure). Flows into the oil take-out pipe 30 from the inflow portion 30a. The lubricating oil 23 is appropriately cooled by the cooler 200 and then injected into the compression chamber 8 through the oil injection pipe 31 and the oil injection port 22.

  The oil injected into the compression chamber 8 in this manner serves to cool the helium gas in the compression chamber 8 and lubricate sliding portions such as the scroll wrap tip. This oil is compressed together with the working gas, and then discharged from the discharge port 10 to the discharge chamber 1a and moves to the lower motor chamber 1b.

  Next, the structure of the fixed scroll 5 is demonstrated using FIG.4 and FIG.5. As described above, the fixed scroll 5 is composed of the disc-shaped end plate 5a and the wrap 5b upright on the disk-shaped end plate 5a. Yes. The wrap 5b forms a wrap outer peripheral surface 562 and a wrap inner peripheral surface 561 having involute curves up to points 58 and 59 at the wrap end portion, and is connected to the suction port 15 in the suction chamber 5f. Ok is a coordinate center point, and Xk and Yk represent coordinate axes.

  Points 53 and 54 serve as contact positions when the wrap end portion of the orbiting scroll 6 is in contact with the wrap outer peripheral surface 562 and the wrap inner peripheral surface 561 to form the compression chamber 8. The points 51 and 52 at the wrap start end portion (innermost peripheral portion) are smoothly connected by the arc radius Rk1. Also, the point 55 on the wrap start end side of the inner curve 561 is smoothly connected to the point 52 by the arcuate radius Rk2 of the concave shape. Reference numerals 5k, 5p, and 5r denote ring-shaped oil grooves for lubrication provided on the surface of the end plate 5a.

  The fixed scroll 5 is provided with an oil injection structure for cooling in order to cool the compressor main body and lower the temperature of heat generated during adiabatic compression of helium gas. The oil injection port 22 of this structure is provided as a single port at a substantially central position with respect to the groove width of the lap tooth groove portion. The port hole diameter do of the oil injection port 22 is set to do> t, where t is the thickness of the wrap 5b. As a practical dimensional relationship, the dimensionless value do / t is set in a range of 1.5 <do / t ≦ 2.5, and the port hole diameter do is 0.45 to the groove width Dt of the wrap. This structure, which is in the range of 0.70, prevents the oil hammer phenomenon at the time of oil injection to supply oil from the oil injection port 22, and also enables reduction of pipe vibration and stress reduction in the helium gas supply piping system. And reduce noise and vibration of the compressor body. The tooth gap dimension (Dt dimension in FIG. 4) of the wrap 5b of the fixed scroll 5 is given by the following equation (1).

油注入用ポート２２の位置となる点５ｓは、点５３と点５４の中間位置の点５ｊに対して巻き角度にして、約（１．５〜１．８）×πｒａｄ分の内側の位置に設定する。この位置に設定することにより、旋回外側圧縮室８ａ及び旋回内側圧縮室８ｂに油インジェクションを注入することができ、これにより油加熱作用を低減し、圧縮機全体の体積効率を向上させることができる。

The point 5s, which is the position of the oil injection port 22, is set to an inner position of about (1.5 to 1.8) × π rad at a winding angle with respect to the point 5j at an intermediate position between the point 53 and the point 54. Set. By setting at this position, oil injection can be injected into the turning outer compression chamber 8a and the turning inner compression chamber 8b, thereby reducing the oil heating action and improving the volumetric efficiency of the entire compressor. .

  Next, the configuration of the orbiting scroll 6 will be described with reference to FIGS. As described above, the orbiting scroll 6 is composed of the disc-shaped end plate 6a and the wrap 6b standing upright on the end plate 6a, and the wrap inner end surface 662 of the involute curve up to the point 64 and the point 65 of the wrap end portion 6k, respectively. An outer peripheral surface 661 is formed. The points 64 and 65 are smoothly connected with an arc radius Rs3. The point 61, the point 62, and the point 63 of the wrap start end portion 6n are smoothly connected by the convex shape having the arc radius Rs1 and the concave shape having the arc radius Rs2. Os is a coordinate center point, and Xs and Ys are coordinate axes.

When the orbiting scroll 6 configured in this way starts turning, the contact point between the orbiting scroll 6 and the fixed scroll 5 moves toward the center. At this time, as shown in FIGS. 8 and 9, the orbiting outer compression chamber 8 a is formed in a space surrounded by the wrap outer peripheral surface 661 of the wrap terminal portion 6 k of the orbiting scroll 6 and the wrap inner peripheral surface 561 of the fixed scroll 5. An orbiting inner compression chamber 8b is formed in a space formed and surrounded by the inner peripheral surface 662 of the orbiting scroll 6 and the outer peripheral surface 562 of the fixed scroll 5. The orbiting outer compression chamber 8a and the orbiting inner compression chamber 8b move while decreasing in volume toward the center, and as a result, the low-pressure helium gas sucked from the suction port 15 is compressed and sealed from the discharge port 10. It is discharged into the space 1a in the container 1.

  Here, the suction volume of the orbiting outer compression chamber 8a and the suction volume of the orbiting inner compression chamber 8b change so as to increase or decrease alternately, that is, when one increases, the other decreases.

  The set volume ratio Vrs set in the orbiting outer compression chamber 8a is defined by the following equation (2). Here, the set volume ratio Vrs is a value obtained by dividing the stroke volume Vths, which is the maximum suction volume of the orbiting outer compression chamber 8a, by the volume Vd1 of the innermost chamber on the orbiting outer compression chamber 8a immediately before the discharge stroke of the compression chamber 8. Means.

  Here, the wrap winding angle will be described. The winding angle refers to a winding end angle or a winding start angle.

In the orbiting scroll 6, the wrap winding end angles at the points 64 and 65 are both 19.24 rad, and the wrap winding start angles at the points 61 and 63 are 1.5 rad and about 4.6 rad, respectively. In contrast, in the fixed scroll 5, which is the inner curve 561 of the wrap of the fixed scroll 5 to the outer curve 562, rad content of a predetermined angle as the winding angle, a structure in which it is extended. The points 51 and 53 of the fixed scroll 5 are relatively at the same positions as the points 63 and 64 of the orbiting scroll 6, respectively. Further, the set volume ratio Vrs of the orbiting outer compression chamber 8a and the set volume ratio Vrk of the orbiting inner compression chamber 8b are set substantially equal. Specifically, the set volume ratio is suitable for relatively low pressure ratio operation conditions of Vrk = Vrs = 2.3 to 2.6. This is due to helium-specific operating conditions in which there are many operating conditions in the pressure ratio region (pressure ratio = 2 to 2.8 or so) where the operating conditions of the compressor for helium are low.

As shown in FIG. 6, the position 6k of the wrap end portion becomes the wrap winding end angles λ _1s and λ _1k , and the position of the wrap start end portion 6n becomes the wrap winding start angles λ _SS and λ _Sk . The tooth gap dimension (Dt dimension in FIG. 6) is given by the following equation (4), similarly to the fixed scroll wrap.

前記のＤｔ寸法とＲｓ２寸法またはＲｋ２寸法とは、ほぼ、Ｄｔ＝Ｒｓ２×２．０またはＤｔ＝Ｒｋ２×２．０の関係となっている。

The Dt dimension and the Rs2 dimension or the Rk2 dimension have a relationship of Dt = Rs2 × 2.0 or Dt = Rk2 × 2.0.

Here, a state when the suction volume of the turning outer compression chamber 8a is maximized and a state when the suction volume of the turning inner compression chamber 8b is maximized will be described with reference to FIGS. As shown in FIG. 8, when the suction volume of the orbiting outer compression chamber 8a is maximum, it wraps the outer peripheral surface 661 of the end portion is in contact with the wrap inner peripheral surface 56 1 of the fixed scroll 5 of the orbiting scroll 6, the point at this time 65 and point 54 are in contact. In contrast, as shown in FIG. 9, when the suction volume of the orbiting inner compression chamber 8b becomes the maximum, wrapped inner peripheral surface 662 of the end portion of the orbiting scroll 6 is in contact with the wrap outer peripheral surface 56 2 of the fixed scroll 5 At this time, the point 64 and the point 53 are in contact with each other.

That is, in this embodiment, in the fixed scroll 5, the winding angle (winding end angle) of the points 53 and 54 that are the contact position with the terminal portion of the orbiting scroll 6 is set to the winding angle of the point 54 with respect to the winding angle of the point 53. angle was πrad extended to form the shape of the absence crawl lap.

  FIG. 10 shows the relationship between the suction volume of the turning outer compression chamber 8a and the turning inner compression chamber 8b and the rotation angle of the crankshaft in the present embodiment. According to the shape of the scroll wrap of this embodiment, the suction completion timing at which the suction volume of the orbiting outer compression chamber 8a is maximized is point B, and the suction completion timing at which the suction volume of the orbiting inner compression chamber 8b is maximized. Is point A. For this reason, the timing at which both compression chambers 8 reach the maximum volume causes a rotational phase difference of 180 degrees, and the suction completion timing is twice during one rotation of the crankshaft 14.

On the other hand, according to the shape of the conventional scroll wrap , as shown in FIG. 16, the suction completion timing is once in one rotation of the crankshaft 14. That is, the suction volume of the orbiting outer compression chamber 8a and the orbiting inner compression chamber 8b is simultaneously maximized at the point C, and when the sum of the suction volumes of both the compression chambers 8 is increased to the point D that is approximately twice the C point.

  Therefore, according to the present embodiment, the suction completion timing can be doubled from once to twice, so that the flow of helium gas and oil during the suction process can be made continuous, and the suction pipes 120, 340 It is possible to alleviate the shock phenomenon that occurs when the gas pressure during the period is closed immediately after the intake of the compressor is completed, and in addition, the pressure pulsation generated on the refrigerator 110 side can be absorbed. As a result, it is possible to prevent the generation of abnormal vibrations in the Oldham mechanism and the like, and to reduce the life of the compressor, thereby improving the reliability.

  In addition, according to this embodiment. Conventionally, since the surge tank that has been arranged in the compressor unit can be eliminated, helium can be directly connected between the refrigerator 110 and the compressor 100 and the unit piping of the compressor can be simplified. The inherent effect of the compressor unit 240 can be obtained. Further, the helium compressor unit 240 as a whole can be reduced in weight and cost.

  Further, as shown in FIGS. 6 and 7, in the orbiting scroll 6, a single intermediate pressure hole 6d penetrating the end plate portion 6a in the axial direction, and a radial horizontal hole 6h provided in the end plate portion 6a in the axial center direction, A single oil drain mechanism comprising an axial oil drain hole 6f that communicates with this and opens in the lap direction, and the intermediate pressure hole 6d and the oil drain hole 6f have openings at positions along the outer curve 661. It is arranged.

In the present embodiment, the compression chambers 8a, 8b is not disposed in the pressure to for constitution deviated rad, the pressure hole 6d and Haiyuana 6f between the middle along the inner curve 662 of the orbiting scroll 6 position. When placed in position along the inner curve 662, such that further [pi r ad inner position, the intermediate pressure hole 6d, must place Haiyuana 6f the orbiting bearing direction, machining of hole machining becomes difficult This is because the above adverse effects occur. The positions of the intermediate pressure hole 6d and the oil drain hole 6f are practically the positions of the following expressions (5) to (7).

  That is, since helium gas does not dissolve in oil, in a closed scroll compressor for helium, for example, the viscosity of oil is about 20 cSt, whereas the scroll compressor for freezing and air conditioning that does not use helium gas. , The working gas dissolves in the oil and is diluted, so that, for example, the oil viscosity is reduced to about 10 cSt. And since the magnitude | size of oil stirring power becomes large in proportion to oil viscosity in the outer peripheral part of the turning scroll 6, the oil stirring power of the compressor 100 is about twice when there is no oil discharge mechanism of this embodiment. Stirring loss power is generated. Therefore, in the sealed scroll compressor for helium, the oil discharge mechanism of this embodiment is necessary to reduce such a large oil stirring power.

  When the oil drain hole 6f is intermittently communicated with the suction chamber 5f in this way, the suction chamber 5f has the lowest suction pressure, so the pressure (intermediate pressure) at the outer peripheral portion of the orbiting scroll 6 and the suction chamber 5f Due to the pressure difference from the pressure, the oil accumulated on the outer periphery of the orbiting scroll 6 can be easily released to the compression chamber 8 side, and the oil agitating power can be easily reduced.

  Further, in this embodiment, as shown in FIG. 8, when the outer peripheral surface of the wrap end portion of the orbiting scroll 6 is in contact with the inner peripheral surface of the fixed scroll and the points 65 and 54 overlap, The tooth tip portion is set so as to be positioned substantially at the center of the opening of the oil injection port 22. Further, when the crankshaft rotates 180 degrees and the inner peripheral surface of the wrap end portion of the orbiting scroll 6 is in contact with the outer peripheral surface of the fixed scroll and the points 64 and 53 overlap as shown in FIG. Similarly, the wrap tooth tip portion of the orbiting scroll 6 is set so as to be positioned substantially at the center of the opening portion of the oil injection port 22.

  With such a positional relationship, both the gas cooling function and the sealing function are made to function substantially equally with respect to the orbiting outer compression chamber 8a and the orbiting inner compression chamber 8b, and the compression efficiency of both the compression chambers 8 is made equal. Can be improved.

  Further, the opening portion of the oil injection port 22 is intermittently communicated with the suction chamber 5f on the outer peripheral side of the lap of the orbiting scroll 6 just before the completion of the suction, and the suction process is performed at a phase of 180 degrees during one rotation of the crankshaft 14. It is performed twice with different. That is, the intermediate pressure hole 6d and the oil discharge hole 6f are not in communication with the oil injection port 22 located on the downstream side via the compression chamber 8 in the state of FIG. 8, but in the state of FIG. It communicates via the chamber 8a. The oil injection port 22 is disposed at a position intermittently communicating with the intermediate pressure hole 6d and the oil discharge hole 6f. Thereby, it is possible to have a function of preventing oil compression in the initial start-up time of the oil accumulated in the compression chamber 8. Further, since the oil sump can be effectively discharged in the suction chamber 5f, there is an inherent effect of the helium hermetic scroll compressor in which an action of reducing oil agitation loss in the suction chamber 5f can be obtained.

  Next, the arc radius of the tip that becomes the winding start portion of the wrap will be described with reference to FIGS. 11 is an enlarged view of the peripheral portion of the discharge hole in FIG. 8, FIG. 12 is an enlarged view of the peripheral portion of the discharge hole in a state in which the compression process has advanced with respect to FIG. 11, and FIG. FIG. 14 is an enlarged view of the periphery of the discharge hole in a state where the compression process and discharge have further progressed with respect to FIG. 13, and FIG. It is a figure explaining the relationship between the working chamber pressure of a compression chamber and a rotation inside compression chamber, and a crankshaft rotation angle.

  The arc radius Rs1 of the tip portion that becomes the winding start portion of the orbiting scroll 6 is set larger than the arc radius Rk1 of the tip portion that becomes the winding start portion of the fixed scroll 5. Specifically, the relationship Rs1> Rk1 is established by setting Rk1 = 1.2 to 1.5 mm and setting Rs1 = 1.8 to 2.2 mm. Further, the arc radius Rs1 and the arc radius Rk1 are set to a ratio range of approximately Rs1 / Rk1 = 1.4 to 1.6. Thereby, the discharge flow timing and phase of the working gas and oil in the turning outer compression chamber 8a and the turning inner compression chamber 8b can be shifted.

  That is, in the swirling outer compression chamber 8a and the swirling inner compression chamber 8b, the compression process and the discharge stroke are performed as shown in FIGS. In FIG. 11, a swirl outer compression chamber 88a and a swirl inner compression chamber 88b in the discharge process communicated with the discharge hole 10 and a swirl outer compression chamber 8a and a swirl inner compression chamber 8b in the compression process by the contacts 78 and 79 are formed. It is in the state. When the compression stroke proceeds with respect to FIG. 11, as shown in FIG. 12, the point 61 of the orbiting scroll 6 forms the contact 110 of the orbiting outer compression chamber 8a, and the point 51 of the fixed scroll 5 becomes the orbiting inner compression chamber 8b. The contact 112 is formed. When the compression stroke further proceeds with respect to FIG. 12, as shown in FIG. 13, the turning outer compression chamber 8a is connected to the innermost chamber 8d side via the gap Ld1, and becomes the turning outer compression chamber 88a of the discharge stroke. The point 51 of the fixed scroll 5 forms the contact 113 with the turning outer compression chamber 8b and is not connected to the innermost chamber 8d side. This is due to the difference between the arc radii Rs1 and Rk1 of the front ends of the scrolls 5 and 6. When the discharge stroke and the compression stroke further advance with respect to FIG. 13, the turning outer compression chamber 88a and the turning inner compression chamber 88b are completely connected to the innermost chamber 8d side via the gaps Ld2 and Ld3. The discharge strokes 88a and 88b are simultaneously performed.

  In the present embodiment, the internal pressure Pis of the orbiting outer compression chamber 8a and the internal pressure Pik of the orbiting inner compression chamber 8b change with respect to the rotation angle of the crankshaft 14 as shown in FIG. As apparent from FIG. 15, in the change of the pressure Pis in the orbiting outer compression chamber 8a, the discharge start timing is point G, the discharge start timing of the orbiting inner compression chamber 8b is point H, and the phase difference Δd1 Will occur. The value of Δd1 is preferably 1 / 3πrad to 1 / 2πrad for practical use. On the other hand, in the prior art, as shown in FIG. 17, the discharge start timings of the swirling outer compression chamber and the swirling outer compression chamber are the same at point E. For this reason, in this embodiment, the discharge start timing is doubled from once to twice as compared with the prior art. As a result, the pressure losses ΔPik and ΔPis that have occurred in the prior art can be greatly reduced like the pressure losses ΔPik and ΔPis shown in FIG.

  In this way, the helium gas flowing out from the discharge port 10 and a large amount of bearing lubricating oil and injection oil flow out at two timings in one rotation of the crankshaft 14, and in combination with securing the discharge passage, Significantly reduced pressure loss due to flow during the process. In particular, as described above, the bearing lubricating oil and the injected total oil amount pass through the discharge hole 10, and the effect inherent to the helium compressor can reduce the discharge pressure loss to about ¼ that of the conventional machine. Can be obtained. In addition to the effect of reducing the discharge pressure pulsation width, there are effects unique to the helium compressor, such as a significant effect of reducing the discharge pressure loss, a reduction in compressor input, and an effect of improving performance.

1 is an overall configuration diagram of a refrigeration apparatus including a helium hermetic scroll compressor according to an embodiment of the present invention. It is a perspective view which shows the external appearance of the compressor unit of FIG. It is a longitudinal cross-sectional view which shows the whole structure of the compressor of FIG. It is a top view of the fixed scroll of FIG. It is a longitudinal cross-sectional view of the fixed scroll of FIG. It is a top view of the turning scroll of FIG. It is a longitudinal cross-sectional view of the turning scroll of FIG. FIG. 4 is a plan sectional view showing a state in which the fixed scroll and the orbiting scroll of FIG. 3 are combined. It is a plane sectional view when the orbiting scroll is further rotated with respect to FIG. It is a figure explaining the relationship between the suction | inhalation volume of a turning outer side compression chamber and a turning inner side compression chamber in this embodiment, and a crankshaft rotation angle. It is an enlarged view of the peripheral part of the discharge hole in FIG. It is an enlarged view of the peripheral part of the discharge hole in the state which the compression process advanced with respect to FIG. It is an enlarged view of the peripheral part of the discharge hole in the state which the compression process advanced further with respect to FIG. FIG. 14 is an enlarged view of a peripheral portion of the discharge hole in a state where the compression process and discharge have further progressed with respect to FIG. 13. It is a figure explaining the relationship between the working chamber pressure and crankshaft rotation angle of the turning outer compression chamber and the turning inner compression chamber in the present embodiment. It is a figure explaining the relationship between the suction | inhalation volume of a rotation outer side compression chamber and a rotation inner side compression chamber, and a crankshaft rotation angle in a prior art. It is a figure explaining the relationship between the pressure in the working chamber of a turning outer side compression chamber and a turning inner side compression chamber, and a crankshaft rotation angle in a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sealed container, 1a ... Discharge chamber, 1b, 1b1, 1b2 ... Motor chamber, 2b ... Casing part, 3 ... Motor part, 5 ... Fixed scroll, 5a ... End plate, 5b ... Wrap, 5f ... Suction chamber, 6 ... Swirling Scroll, 6a ... End plate, 6b ... Wrap, 6n ... Wrap start end, 7 ... Frame, 8 ... Compression chamber, 8a ... Swivel outer compression chamber, 8b ... Swivel inner compression chamber, 10 ... Discharge port, 14 ... Crankshaft, 14a ... Eccentric shaft, 15, 15a, 15b ... Suction port, 17 ... Suction pipe, 20 ... Discharge pipe, 22 ... Oil injection port, 23 ... Lubricating oil, 30 ... Oil extraction pipe, 31 ... Oil injection pipe, 32 ... Swivel bearing , 39 ... auxiliary bearings, 40 ... main bearing, 561 ... fixed scroll wrap inner peripheral surface, 562 ... fixed scroll wrap outer peripheral surface, Rk1 ... arc radius of the fixed scroll wrap starting end, Rs1 ... orbiting scroll Arc radius of the lapping start end, Vrs ... set volume ratio of the orbiting outer compression chamber, Vths ... stroke volume as maximum suction volume of the orbiting outer compression chamber, Vrk ... set volume ratio of the orbiting inner compression chamber, Vthk ... The stroke volume that is the maximum suction volume.

Claims (3)

Helium gas is used as a working gas, and a scroll compressor part and an electric motor part for driving the scroll compressor part are housed in an airtight container, and the scroll compressor part is spirally formed on a disk-shaped end plate. The fixed scroll provided upright with the lap and the orbiting scroll provided upright with the spiral wrap on the disc-shaped end plate are meshed with the wraps inside each other, and the orbiting scroll is connected to the eccentric part of the crankshaft. And the revolving scroll is revolved with respect to the fixed scroll without rotating, and the fixed scroll is provided with a discharge port that opens at a central portion and a suction port that opens at an outer peripheral portion. Helium gas is sucked from the suction port with the swivel motion and moved around the compression chamber formed by the two scrolls to reduce the volume, thereby reducing the helium gas. The compressed helium gas is discharged from the discharge port, and an oil injection pipe that guides oil for cooling the helium gas passes through the hermetic container to the end plate portion of the fixed scroll. In a sealed scroll compressor for helium equipped with an oil injection mechanism connected to an oil injection port provided,
When the orbiting outer compression chamber formed by being surrounded by the outer peripheral surface of the wrap at the end of winding of the orbiting scroll and the inner peripheral surface of the wrap of the fixed scroll has the maximum suction volume, Orbital inner compression formed by the outer peripheral surface of the wrap and the inner peripheral surface of the fixed scroll contacting at the first contact position and being surrounded by the inner peripheral surface of the orbiting scroll and the outer peripheral surface of the fixed scroll. When the chamber has the maximum suction volume, the wrap inner peripheral surface of the wrap winding end of the orbiting scroll and the wrap outer peripheral surface of the fixed scroll are in contact at the second contact position,
The winding angle of the first contact position of the fixed scroll is extended by a predetermined angle with respect to the winding angle of the second contact position of the fixed scroll,
The arc radius of the front end portion that becomes the winding start portion of the orbiting scroll is set larger than the arc radius of the front end portion that becomes the winding start portion of the fixed scroll, and the arc of the front end portion that becomes the winding start portion of the fixed scroll When the radius is Rk1, and the arc radius of the tip portion that becomes the winding start portion of the orbiting scroll is represented as Rs1,
Rs1 / Rk1 = 1.4 to 1.6
The arc radius of each of the fixed scroll winding start portion and the orbiting scroll winding start portion is set so as to be within the range, and the discharge start timing of the orbiting outer compression chamber and the discharge start of the orbiting inner compression chamber are set. The timing is shifted from 1 / 3π rad to 1 / 2π rad so that the working gas and oil discharge flow timing and phase in the swirling outer compression chamber and swirling inner compression chamber are shifted . Hermetic scroll compressor. 2. The opening of the oil injection port according to claim 1, wherein when the suction is completed, which is the timing of forming the maximum sealed volume of the orbiting inner compression chamber formed by the inner curve of the orbiting scroll and the outer curve of the fixed scroll. The helium-enclosed scroll is characterized in that the oil injection port is provided at a substantially central position of the tooth space of the fixed scroll so that a lap tooth tip portion of the orbiting scroll is located at a substantially central position. Compressor. 2. The opening of the oil injection port communicates with both the swirling outer compression chamber and the swirling inner compression chamber when one of the swirling outer compression chamber and the swirling inner compression chamber reaches a maximum volume. Thus, a sealed scroll compressor for helium , wherein the oil injection port is arranged .

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