JP2012219791A - Hermetic scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, in a scroll compressor having an oil filling port set and machined in a direction perpendicular to the lap bottom land of a fixed scroll, cooling oil when filled into a compression chamber is drifted by a high-velocity gas flow to cause insufficient mixing of the cooling oil with gas, insufficient heat exchange between the gas and the cooling oil, and thus insufficient lowering of the temperature of gas discharged from the compressor, by improving the heat exchange between the gas and the cooling oil.SOLUTION: This hermetic scroll compressor includes a rotary scroll and a fixed scroll forming a compression chamber to compress cooling medium, the fixed scroll having a filling port for filling gas or liquid into the compression chamber, the filling port being formed obliquely to the base plate of the fixed scroll.

Description

  The present invention relates to a hermetic scroll compressor, and is particularly suitable for a hermetic scroll compressor for refrigeration / air conditioning and helium.

  As a prior art, a rotary scroll compressor and a fixed scroll form a compression chamber for compressing refrigerant, and the fixed scroll has a hermetic scroll compressor having an injection port for injecting gas or liquid into the compression chamber. ing.

  The scroll compressor of patent document 1 compresses gas, such as air and a refrigerant | coolant, and is fixed to a casing so that the end surface of this cylindrical casing and this casing may be obstruct | occluded. A fixed scroll in which a wrap is erected, and a spiral wrap that is positioned in the casing so as to be pivotable on the drive shaft, and forms a plurality of compression chambers on the end plate overlapping the fixed scroll wrap and swiveling Is composed of orbiting scrolls.

  The end plate of the fixed scroll is provided with two oil injection ports spaced apart in the radial direction, and the radial interval between the oil injection ports is equal to or slightly larger than the tooth thickness of the orbiting scroll. Is set to Each oil injection port communicates with one oil supply port. The oil injection port on the center side is installed so as to communicate with the orbiting outer compression chamber in a state where the orbiting scroll lap contacts the outer side of the fixed scroll wrap.

  Further, as a conventional hermetic scroll compressor, there is a helium hermetic scroll compressor disclosed in Patent Document 2. In this hermetic scroll compressor, a compressor unit and an electric motor unit that drives the compressor unit are housed and disposed in a hermetic container.

  This compressor unit meshes a fixed scroll in which a spiral wrap is erected on a disc-shaped end plate and a turning scroll in which a spiral wrap is erected on a disc-like end plate, with these wraps 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, and providing the fixed scroll with an outlet opening at the center and an inlet opening at the outer periphery, Helium gas is sucked from the suction port, moved around the compression chamber formed by the fixed scroll and the orbiting scroll, the volume is reduced, and helium gas is compressed and discharged from the discharge port.

  The compressor unit also includes an oil injection mechanism unit in which an injection pipe for injecting fluid into the compression chamber in the middle of compression is connected to one oil injection port provided on the lap tooth bottom surface of the fixed scroll through the sealed container. ing. The diameter of the oil injection port is set larger than the wrap width of the orbiting scroll.

No. 1-176969 Japanese Patent Laid-Open No. 2004-232481

  In the above-described scroll compressor, the oil injection port is set in a direction perpendicular to the bottom surface of the wrap tooth of the fixed scroll, and when the cooling oil is injected into the compression chamber, it is pushed away by the high-speed gas flow, In addition, the gas and the cooling oil are not mixed, and the heat exchange between the gas and the cooling oil is insufficient, so that the discharge gas temperature of the compressor is not sufficiently lowered.

  For example, when a certain amount of cooling oil is injected into the compression chamber in a direction perpendicular to the bottom surface of the wrap tooth of the fixed scroll, the heat of the gas and the cooling oil is not sufficiently exchanged. The orbiting scroll expands excessively. Then, each other wears and power loss occurs, resulting in an increase in power consumption.

  For example, when a certain amount of cooling oil is injected into the compression chamber in a direction perpendicular to the bottom surface of the wrap tooth of the fixed scroll, heat exchange between the gas and the cooling oil is insufficient, so that more helium gas is cooled. Cooling oil needs to be injected. In this case, power consumption is increased due to an increase in compression power.

  Furthermore, if the amount of cooling oil injected increases, an oil hammer phenomenon will occur if the orbiting scroll wrap closes the injection port, resulting in increased piping vibration and piping stress in the oil piping system, resulting in compressor noise. In addition, the vibration of the entire compressor is increased.

  That is, the above problem can be improved by improving the heat exchange between the gas and the cooling oil.

  Therefore, an object of the present invention is to improve heat exchange between gas and cooling oil.

The object of the present invention is as follows.
The orbiting scroll and the fixed scroll form a compression chamber that compresses the refrigerant,
The fixed scroll is a hermetic scroll compressor having an injection port for injecting gas or liquid into the compression chamber.
This is achieved by a hermetic scroll compressor characterized in that the injection port is formed obliquely with respect to the fixed scroll base plate.

  According to the present invention, the degree of heat exchange between the gas and the cooling oil can be further increased.

The longitudinal cross-sectional view which shows the whole structure of a compressor. The top view of the fixed scroll of FIG. The longitudinal cross-sectional view of the fixed scroll of FIG. The top view of the turning scroll of FIG. FIG. 5 is a longitudinal sectional view of the orbiting scroll of FIG. 4. The figure which looked at the cross section in the A1-A2 connection of FIG. 7 from the suction side. FIG. 2 is a plan sectional view showing a state in which the fixed scroll and the orbiting scroll of FIG. 1 are combined. FIG. 8 is a plan sectional view when the orbiting scroll is further rotated with respect to FIG. 7. The figure explaining the relationship between the suction | inhalation volume of a turning outer side compression chamber and a turning inner side compression chamber in 1st Embodiment, and a crankshaft rotation angle. The plane sectional view showing the state where the fixed scroll and turning scroll of a 2nd embodiment of the present invention were combined. The figure which looked at the cross section in A3-A4 connection of FIG. 10 from the suction side. The whole block diagram of the refrigerating device provided with the sealed scroll compressor for helium.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  In FIG. 12, the refrigeration apparatus 300 includes a vertical type helium hermetic scroll compressor 100 (hereinafter, abbreviated as the 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 is connected between an oil take-out pipe 30 that communicates with the lubricating oil 23 that accumulates at the bottom of the compressor 100 and an oil injection pipe 31 that communicates with the compression chamber 8 of the compressor 100.

  The lubricating oil 23 stored at the bottom of the sealed container 1 is taken out from the oil take-out pipe 30 by the discharge pressure in the inner space of the sealed container 1 and led to the oil cooler 200 through the pipe 220, where After being cooled by air, it flows through an oil piping path 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 into the compressor 100 by being injected into the compression chamber 8 of the compressor 100 through the oil injection port 22 (see FIG. 1).

  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 flows into the oil adsorber 170 via the pipe 330, and after the oil residue is further separated, it is introduced into the refrigerator 110 via the pipe 130. The helium gas introduced into the refrigerator 110 becomes a cold heat source by being adiabatically expanded inside. 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.

  Next, the overall configuration of the compressor 100 will be described with reference mainly to FIG. The compressor 100 houses a compressor unit 4 and a motor unit 3 that serves as an electric motor in a vertically long sealed container 1 that are arranged up and down. The sealed container 1 is configured by combining an upper lid 2a, a barrel portion 2b that is a cylindrical casing portion, and a bottom portion 2c. The 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. In this embodiment, a so-called asymmetric wrap type scroll compressor is used.

  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 15a (see FIGS. 2 and 3). 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.

  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. A main bearing 40 is formed at the center of the frame 7, and the crankshaft 14 is supported on the main bearing 40. 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 provided so as to penetrate the upper lid 2 a of the sealed container 1 and communicate with an oil injection port 22 provided on the end plate 5 a of the fixed scroll 5. The oil injection port 22 is opened facing 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.

  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 edges of the frame 7, and the motor chamber 1b communicates with the discharge pipe 20 that penetrates the body 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 oil and oil are 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. 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 mixture of gas and cooling oil in the spaces 1b1 and 1b2 inside the container, it is possible to directly cool the motor unit 3 with a relatively low temperature injection oil of, for example, 60 ° C 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 via the lower second passage 25b.

  A space 36 (hereinafter referred to as an intermediate pressure chamber 36) surrounded by the 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 the suction pressure and the 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 the axial direction is applied to press the orbiting scroll 6 against the fixed scroll 5. Power is given.

  The oil separated from the helium gas is stored as lubricating oil 23 at the bottom of the sealed container 1. The lubricating oil 23 is sucked up into the oil suction pipe 27 by the difference between the high pressure (discharge pressure) in the internal space of the sealed container 1 and the intermediate pressure in the intermediate pressure chamber 36, The central hole 13 is raised, and oil is supplied to the swivel bearing 32 from the upper end of the central hole 13 and is supplied to the auxiliary bearing 39 and the main bearing 40 through the lateral hole 51. The lubricating oil 23 supplied to the slewing bearing 32 and the main bearing 40 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 discharged together with the helium gas. It is discharged into the chamber 1a. 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.

  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. The lubricating oil 23 stored in the bottom of the sealed container 1 is caused by a differential pressure between the high pressure (discharge pressure) in the inner space of the sealed container 1 and the pressure in the compression chamber 8 during compression (pressure lower than the discharge pressure). The oil flows into the oil take-out pipe 30 from the inflow portion 30 a of the oil take-out pipe 30. 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 discharged together with the working gas from the discharge port 10 to the discharge chamber 1a and moves to the lower motor chamber 1b.

  Next, the configuration of the fixed scroll 5 will be described with reference mainly to FIGS. 2 and 3.

  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. The fixed scroll 5 includes the discharge port 10 at the center and the suction ports 15 (15a and 15b) at the outer periphery. Yes. The wrap 5b forms a lap outer peripheral surface 562 and an inner peripheral surface 561 of an involute curve up to points 58 and 59 at the wrap end portion, respectively, 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 indicate the contact positions of the outermost peripheral part forming the compression chamber 8. That is, the points 53 and 54 are 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 stroke volume Vths on the side of the orbiting outer compression chamber 8a formed by the orbiting scroll wrap outer curve 661 and the fixed scroll wrap inner curve 561 is the orbiting inner side formed by the orbiting scroll wrap inner curve 662 and the fixed scroll wrap outer curve 562. It increases with respect to the stroke volume Vthk on the compression chamber 8b side. A point 54 that is the contact position of the outermost peripheral portion forming the turning outer compression chamber 8a of the fixed scroll wrap inner curve 561 extends the winding angle by π rad with respect to the prior art.

  The points 51 and 52 at the wrap start end portion (innermost peripheral portion) are smoothly connected by the arc radius Rk1. The point 55 on the wrap start end side of the inner curve 561 is smoothly connected to the point 52 by a concave shape having an arc radius Rk2. 5k is a ring-shaped oil groove for lubrication provided on the surface of the end plate 5a, and 5p and 5r are arc-shaped oil grooves for lubrication provided on the surface of the end plate 5a.

  The tooth gap dimension (Dt dimension in FIG. 2) of the fixed scroll 5 is given by the following equation (1).

  Next, the configuration of the orbiting scroll 6 will be described with reference mainly to FIGS. 4 and 5.

  As described above, the orbiting scroll 6 is composed of the disc-shaped end plate 6a and the wrap 6b that stands upright on the end plate 6a. 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 end portion 6n are smoothly connected by a convex shape having an arc radius Rs1 and a concave shape having an arc radius Rs2. Os is a coordinate center point, and Xs and Ys are coordinate axes.

  The groove 6 m is provided at a position facing the discharge port 10 of the fixed scroll 5, and is formed by a recess having a size equivalent to that of the discharge port 10.

  In the orbiting scroll 6, a single intermediate pressure hole 6d penetrating the end plate portion 6a in the axial direction, a radial horizontal hole 6h provided in the end plate 6a in the axial center direction, and an axial direction opening in the lap direction in communication therewith. A single oil drain mechanism comprising the oil drain hole 6f is provided, and the intermediate pressure hole 6d and the opening of the oil drain hole 6f are arranged at positions along the outer curved line 661. The intermediate pressure hole 6d is not set at a position along the inner curve 662 of the orbiting scroll 6 because the compression chambers 8a and 8b are displaced by π rad in terms of pressure. If the position along the inner curve 662 is set, the holes 6d and 6f are positioned in the direction of the slewing bearing so as to be further on the inner side of πrad, which causes a machining problem that hole machining becomes difficult. It is.

  Next, the oil injection mechanism will be described with reference mainly to FIGS.

  An oil injection structure for cooling is provided for cooling the main body of the compressor and cooling the temperature rise due to heat generated during adiabatic compression of helium gas, and for lubrication and sealing of the sliding portion between the laps. An oil injection port 22 that uses oil as a cooling liquid is provided in the end plate 5a. An opening on the bottom side of the fixed scroll wrap tooth groove of the oil injection port 22 is an oil injection port opening 22a, and an opening on the connection side with the oil injection pipe 31 is an oil injection port opening 22b. Accordingly, the mixing function can be promoted by disturbing the flow of the gas and the cooling oil in each of the turning outer compression chamber 8a and the turning inner compression chamber 8b, and the heat exchange function between the gas and the cooling oil can be enhanced. This action can reduce the required cooling oil injection amount.

  On the other hand, increasing the cooling effect in the compressor brings about an effect of reducing internal leakage between the compression chambers and recompression power. For this reason, reduction of the compression power of gas and cooling oil is achieved, and the power consumption of the whole compressor can be reduced. Further, since the heat exchange function is enhanced, excessive thermal expansion of the fixed scroll 5 and the orbiting scroll 6 can be prevented, and wear of the fixed scroll wrap 5b and the orbiting scroll wrap 6b due to sliding can be prevented.

  The oil injection port 22 supplies oil to the orbiting outer compression chamber 8a formed by the orbiting scroll outer curve 661 and the fixed scroll inner curve 561 and to the orbiting inner compression chamber 8b formed by the orbiting scroll inner curve 662 and the fixed scroll outer curve 562. Is provided at a substantially central position with respect to the groove width of the lap tooth groove bottom surface 5 m.

  The center line Zk of the oil injection port 22 is set to the fixed scroll inner curve 561 side with respect to the lap tooth groove bottom surface 5m so that the oil injection port opening 22a is directed to the side wall portion on the fixed scroll outer curve 562 side. It is the shape which injects to the angle θ1 (about 60 degrees) obliquely. The flow path length L5 of the oil injection port 22 is set to an appropriate length.

  Between the oil injection pipe 31 and the fixed scroll 5, an O-ring 31e for sealing between the discharge chamber 1a which is a high pressure chamber and the compression chamber 8 is provided. The hole diameter Φd1 of the oil injection port 22 is set to be equal to or larger than the wrap thickness t. With this structure, as shown in FIG. 6, the oil injected into the swivel inner compression chamber 8 b runs along the side wall portion on the fixed scroll outer curve 562 side that becomes a low speed region T <b> 1 (dotted line range) of gas generated by the flow path resistance. Since it moves to the tooth groove bottom face of the orbiting scroll, the flow of gas and cooling oil is disturbed, and the mixing function is promoted, the degree of heat exchange between the gas and cooling oil can be increased.

  As described above, the power consumption can be reduced and the compressor reliability can be improved. Furthermore, increasing the heat exchange between the gas and the cooling oil can further prevent the oil hammer phenomenon by reducing the injection amount at the time of cooling oil injection, so that the pipe vibration of the oil pipe system and the pipe stress are reduced, the compressor noise and the compressor An effect of reducing the overall vibration can be obtained.

  The position of the oil injection port 22 is set to a position inside the scroll wrap winding angle with respect to the point 5j (see FIG. 2) by about 2 × πrad. By setting at these positions, immediately after the helium gas intake stroke is completed, in order to perform an oil injection operation (oil injection), injection oil is injected into the turning outer compression chamber 8a and the turning inner compression chamber 8b. The effect of improving the volumetric efficiency of the compressor can be obtained by reducing the heating action.

  The oil injection pipe 31 has an elbow structure. The oil injection pipe 31 passes through the upper lid 2 a of the sealed container 1 and communicates with an oil injection port 22 provided on the end plate 5 a of the fixed scroll 5.

  Next, the compressor unit 4 will be described with reference mainly to FIGS.

  When the turning scroll 6 starts turning, the contact point between the turning scroll 6 and the fixed scroll 5 moves toward the center. At this time, as shown in FIGS. 7 and 8, a turning outer compression chamber 8 a is formed in a space surrounded by the wrap outer peripheral surface 661 of the wrap end 6 n of the orbiting scroll 6 and the wrap inner peripheral surface 662 of the fixed scroll 5. In the space surrounded by the wrap inner peripheral surface 662 of the orbiting scroll 6 and the wrap outer peripheral surface 562 of the fixed scroll 5, the orbiting inner compression chamber 8b is formed. The swirling outer compression chamber 8a and the swirling inner compression chamber 8b move while reducing the volume sequentially 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 means a value obtained by dividing the stroke volume Vths 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.

  On the other hand, the set volume ratio Vrk set in the turning inner compression chamber 8b is defined by the following equation (3). Here, the set volume ratio Vrk means a value obtained by dividing the stroke volume Vthk of the orbiting inner compression chamber 8b by the volume Vd1 of the innermost chamber on the side of the orbiting inner compression chamber 8b immediately before the discharge stroke of the compression chamber.

  The stroke volumes of the orbiting outer compression chamber 8a and the orbiting inner compression chamber 8b are in a relationship of Vths> Vthk due to their geometric shapes. In addition, 6 m of the orbiting scroll 6 has a groove shape of a concave portion having a size equivalent to the discharge port 10 on the fixed scroll 5 side.

  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.

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

  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. 7, when the suction volume of the orbiting outer compression chamber 8a is maximized, the wrap outer peripheral surface 661 at the end of the orbiting scroll 6 contacts the wrap inner peripheral surface 561 of the fixed scroll 5, and at this time the point 65 And point 54 are in contact. FIG. 7 shows a state when the suction is completed, which is the timing for forming the maximum sealed volume of the swirling outer compression chamber 8a. In a state where the point 65 overlaps with the point 54, the oil injection port opening 22a is in a positional relationship where the orbiting scroll wrap tooth tip is blocked.

  On the other hand, as shown in FIG. 8, when the suction volume of the orbiting inner compression chamber 8b is maximized, the wrap inner peripheral surface 662 at the end of the orbiting scroll 6 comes into contact with the wrap outer peripheral surface 562 of the fixed scroll 5, At this time, the points 64 and 53 come into contact with each other. FIG. 8 shows a state when the suction is completed, which is the timing for forming the maximum sealed volume of the swivel inner compression chamber 8b. Thereafter, when the crankshaft turns 180 degrees, the state shown in FIG. 7 is entered.

  With this positional relationship, both the gas cooling function and the sealing function in the working chamber to the turning outer compression chamber 8a and the turning inner compression chamber 8b can be made to function substantially equally. Moreover, the compression efficiency (illustration efficiency) of both compression chambers can be improved equally.

  In the present embodiment, in the fixed scroll 5, the winding angle of the points 53 and 54 (winding end angle) that is the contact point 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. In addition, the scroll wrap shape is formed so that the winding angle (winding end angle) of the points 64 and 65 coincides with the winding angle of the point 54 of the fixed scroll 5 in the orbiting scroll 6.

  FIG. 9 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 this 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.

  In the present embodiment, since the orbiting outer compression chamber 8a and the orbiting inner compression chamber 8b are configured to deviate by π rad in pressure, the intermediate pressure hole 6d and the oil drain hole 6f are arranged at positions along the inner curve 662 of the orbiting scroll 6. Not done. If it is arranged at a position along the inner curve 662, the intermediate pressure hole 6d and the oil drain hole 6f must be arranged in the swivel bearing direction so as to be further on the inner side of πrad. This is because harmful 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).

  The opening of the intermediate pressure hole 6d that opens to the orbiting outer compression chamber 8a has a communication angle of Δλd (1.0 to 1.5 rad) intermittently communicating with the suction chamber 5f on the outer periphery of the orbiting scroll 6 lap. The oil discharge hole 6f is intermittently communicated with the suction chamber 5f by 0.5 rad. As a result, the oil draining mechanism including the horizontal hole 6h and the oil draining hole 6r allows oil accumulated in the outer peripheral portion of the orbiting scroll 6 to escape to the compression chamber 8 side due to a pressure difference, and reduces oil stirring power in the outer peripheral portion. Therefore, the power consumption of the compressor motor can be reduced.

  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. 7, 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 oil injection port opening 22a. Further, when the crankshaft rotates 180 degrees and the inner peripheral surface of the wrap end portion of the orbiting scroll 6 comes into 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 oil injection port opening 22a.

  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.

  The oil injection port opening 22a 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 has a phase of 180 degrees during one rotation of the crankshaft 14. It will be done twice. That is, the intermediate pressure hole 6d and the oil drain 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. 7, 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.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.

  The second embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In this second embodiment, the oil injection port opening 22a has the center line Zk of the oil injection port 22 with respect to the lap tooth groove bottom surface 5m so that the cooling oil proceeds to the side wall portion on the fixed scroll inner curve 561 side. Thus, the shape is ejected obliquely at an angle θ2 (about 60 degrees) toward the fixed scroll outer curve 562 side. With this structure, the oil injected into the orbiting outer compression chamber 8a passes along the side wall portion on the fixed scroll inner curve 561 side, which is the low speed region T2 (dotted line range) of the gas generated by the flow path resistance, to the tooth groove bottom surface of the orbiting scroll. And the flow of gas and cooling oil is disturbed, the mixing function is promoted, and the heat exchange function between the gas and cooling oil can be enhanced. As in the first embodiment, the power consumption can be reduced and the compressor reliability can be improved. Furthermore, increasing the heat exchange between the gas and the cooling oil can further prevent the oil hammer phenomenon by reducing the injection amount at the time of cooling oil injection, so that the pipe vibration of the oil pipe system and the pipe stress are reduced, the compressor noise and the compressor An effect of reducing the overall vibration can be obtained.

(Third embodiment)
In the above-described embodiment, the compressor to which the asymmetric wrap is applied has been described, but the same effect can be obtained even in a scroll compressor having a symmetric wrap shape by applying the present invention.

  In the above-described embodiment, the compressor in which the working gas is helium gas and oil is injected as a cooling medium has been described. However, the present invention also provides cooling for a refrigeration / air-conditioning scroll compressor that uses CFC refrigerant. It can also be applied as a liquid refrigerant for cooling provided on the fixed injection scroll structure or the fixed scroll side or a structure for injecting wet refrigerant. Specifically, in the case where the working gas is a chlorofluorocarbon refrigerant gas, for example, R22, R410A, R404A refrigerant, etc., the cooling liquid is a high-pressure chlorofluorocarbon liquid refrigerant, or a gas or liquid refrigerant or a wet state in the compression chamber. It is a compressor structure in which a chlorofluorocarbon refrigerant is injected.

  As described above, each embodiment promotes the mixing function by disturbing the flow of the respective gas and cooling oil in the swirling outer compression chamber and the swirling inner compression chamber, and enhances the heat exchange function between the gas and the cooling oil, That is, the degree of heat exchange can be further increased. In addition, the structure that can inject the minimum injection amount necessary for cooling can reduce power consumption, and also reduce the vibration of the oil piping system, the piping stress, the compressor noise and the overall compressor vibration. Reliability can be improved.

  Moreover, mixing is promoted by disturbing the flow of the gas and cooling oil in the swirling outer compression chamber and the swirling inner compression chamber, heat exchange between the gas and cooling oil is increased, and compression power and power consumption are reduced. it can.

DESCRIPTION OF SYMBOLS 1 Airtight container 1a Discharge chamber 1b, 1b1, 1b2 Motor chamber 2b Casing part 3 Motor part 4 Compressor part 5 Fixed scroll 5a, 6a End plate 5b, 6b Lap 5f Suction chamber 6 Orbiting scroll 6n Lap end 7 Frame 8 Compression chamber 8a Swirling outer compression chamber 8b Swirling inner compression chamber 10 Discharge port 14 Crankshaft 14a Eccentric shaft 15, 15a, 15b Suction port 17 Suction tube 20 Discharge tube 22 Oil injection port 22a, 22b Oil injection port opening 23 Lubricating oil 30 Oil Extraction pipe 31 Oil injection pipe 32 Slewing bearing 39 Sub bearing 40 Main bearing 561 Fixed scroll wrap inner peripheral surface 562 Fixed scroll wrap outer peripheral surface Rk1 Arc radius Rs1 of fixed scroll wrap start end Arc radius Vrs of swing scroll wrap start end Outer compression chamber set volume ratio Vths Swing outer pressure Chamber stroke volume Vrk orbiting inner compression chamber set volume ratio Vthk orbiting inner compression chamber of the stroke volume .theta.1, .theta.2 inclination of the oil injection port

Claims (6)

The orbiting scroll and the fixed scroll form a compression chamber that compresses the refrigerant,
The fixed scroll is a hermetic scroll compressor having an injection port for injecting gas or liquid into the compression chamber.
The hermetic scroll compressor, wherein the injection port is formed obliquely with respect to the base plate of the fixed scroll.   2. The hermetic scroll compressor according to claim 1, wherein a working gas of the hermetic scroll compressor is helium gas, and oil is injected into the compression chamber.   The hermetic scroll compressor according to claim 1, wherein a working gas of the hermetic scroll compressor is a chlorofluorocarbon refrigerant, and a gas, a liquid, or a wet refrigerant is injected into the compression chamber.   4. The hermetic scroll compressor according to claim 3, wherein a dimension of the hole diameter of the injection port is equal to or less than a dimension of a wrap thickness of the opposed orbiting scroll.   3. The hermetic scroll compressor according to claim 2, wherein a dimension of the hole diameter of the injection port is larger than a dimension of a wrap thickness of the opposed orbiting scroll.   The injection port is inclined with respect to the base plate so that the gas or liquid to be injected is injected obliquely from the bottom of the fixed scroll toward the side wall of the fixed scroll wrap forming the compression chamber. The hermetic scroll compressor according to claim 1, wherein the hermetic scroll compressor is formed.

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