JP2001153072A - Hermetic scroll compressor - Google Patents

Abstract

(57) [Problem] To provide an oil injection type hermetic scroll compressor capable of preventing bearing seizure accidents and improving the reliability of the scroll compressor. A groove parallel to the eccentric shaft surface engaged with the slewing bearing portion on a bearing surface having a phase angle advanced by about 90 degrees with respect to the load direction acting on the eccentric shaft portion of the slewing bearing portion. And a groove parallel to the axial direction is formed on the rotating shaft surface that engages with the auxiliary bearing portion. The groove depth with respect to the shaft diameter on the auxiliary bearing portion side is the groove depth with respect to the shaft diameter on the swing bearing portion side. Set large for.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hermetic scroll compressor having a mechanism for improving lubrication of a bearing portion,
Particularly, the present invention relates to a hermetic scroll compressor suitable for use in a helium compressor for a cryopump device in an ultra-high vacuum field using helium gas as a working gas.

[0002]

2. Description of the Related Art In a conventional hermetic scroll compressor using helium gas as a working gas, a so-called high-pressure chamber system in which the inside of the hermetic container is kept at a high pressure state and cooling with oil, a so-called oil injection system (hereinafter, referred to as an oil injection system). Among those employing an oil injection method), as disclosed in, for example, Japanese Patent Application Laid-Open No. 61-112794, the oil in the bottom of the closed vessel is once guided to the outside of the closed vessel, and is then passed through an oil cooler. And then re-injected into the compressor section of the scroll compressor.

[0003]

The above prior art has the following problems. That is, in the case of the helium compressor, the helium gas does not dissolve in the oil unlike the refrigerant Freon 22, so that the oil is not diluted by the refrigerant and the oil viscosity is kept high. Therefore, when the differential pressure for lubrication is reduced to several kg / cm ² , such as in low pressure pressure ratio conditions, the amount of oil required for the bearing with the differential pressure lubrication structure is insufficient for the required amount of oil for the bearing. There is a problem specific to helium compressors that causes seizure accidents in parts.

FIG. 15 shows the structure of the bottom chamber of the above-mentioned prior art hermetic scroll compressor. This conventional example is shown in FIG.
As shown in the figure, since the position of the inlet of the oil discharge pipe 30 and the lower end of the oil suction pipe 15d at the lower end of the rotary shaft 15 are at the same level, the oil level is abnormally lowered and the lower end of the oil suction pipe 15d When the position is reached, the gas enters the oil suction pipe 15d, and as a result, there is a problem that the bearing is not lubricated and a seizure accident occurs.

The present invention has been made in view of the above-mentioned problems of the prior art, but is applicable not only to a helium compressor but also to a general scroll compressor. Another object of the present invention is to provide an oil injection type hermetic scroll compressor which can prevent bearing seizure accidents and improve the reliability of the scroll compressor.

[0006]

In order to achieve the above object, a hermetic scroll compressor according to the present invention is characterized by what is described in each of the claims. According to a first aspect of the present invention, there is provided a hermetic scroll compressor in which a compressor portion and an electric motor portion are housed in a closed container, and the compressor portion is configured to erect a spiral wrap on a disk-shaped end plate. The scroll and the orbiting scroll are engaged with each other with the wrap inside, the orbiting scroll is engaged with an eccentric mechanism connected to the rotation axis, and the orbiting scroll is rotated with respect to the fixed scroll without rotating, and the fixed scroll is centered. Provide a discharge port that opens to the part and a suction port that opens to the outer periphery, suck working gas from the suction port, and move around the compression chamber formed by both scrolls to reduce the volume. The working gas is compressed, the compressed gas is discharged from a discharge port into the container chamber, and the working gas is further discharged outside through a discharge pipe. A back pressure chamber surrounded by a compressor unit and a frame is formed on the back surface of the end plate of the orbiting scroll, and a pore is formed in the end plate of the orbiting scroll in the back pressure chamber. Scroll compressor in which an intermediate pressure between the discharge pressure and the discharge pressure is introduced, and oil in an oil sump is supplied to the various bearing portions and the compression chambers via an oil suction pipe by a differential pressure between the discharge pressure and the intermediate pressure. A groove parallel to the eccentric shaft surface engaged with the slewing bearing portion on a bearing surface having a phase angle advanced by about 90 degrees with respect to a load direction acting on the eccentric shaft portion of the slewing bearing portion. And the rotating shaft surface engaged with the auxiliary bearing portion. A groove parallel to the axial direction is formed, and a groove depth with respect to the shaft diameter on the auxiliary bearing portion side is set to be larger than a groove depth with respect to the shaft diameter on the slewing bearing portion side. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows a main bearing portion using a differential pressure lubrication system,
FIG. 3 is a cross-sectional view of a general hermetic scroll compressor in which lubricating oil is supplied to an auxiliary bearing portion and a turning bearing portion. In FIG. 1, a compressor unit 2 is accommodated in an upper part of a closed container 1, and a motor unit 3 is accommodated in a lower part. The inside of the closed container 1 is divided into an upper space 1a, a middle space 1b, and a lower space 1f. In the compressor section 2, a compression chamber 8 is formed by engaging the fixed scroll 5 and the orbiting scroll 6 with each other.

The fixed scroll 5 has a disk-shaped end plate 5a.
And a wrap 5b which stands upright and is formed into an involute curve or a curve approximating the same, and has a discharge port 10 at the center and a suction port 14 at the outer periphery. The orbiting scroll 6 has a disk-shaped end plate 6a and a wrap 6 which stands upright and has the same shape as the wrap of the fixed scroll.
b, and a boss 6c formed on the opposite side of the end plate from the lap.

The frame 11 has an auxiliary bearing 26 at the center,
The main bearing 27 is formed, and the rotating shaft 15 is supported by these bearings. The eccentric shaft 15 a at the tip of the rotating shaft 15 is connected to the boss 6.
c is inserted so as to be able to perform a turning motion. The fixed scroll 5 is fixed to the frame 11 by a plurality of bolts. The orbiting scroll 6 is supported on the frame 11 by an Oldham mechanism 12 including an Oldham ring and an Oldham key. It is configured to make a turning motion without rotating.

The rotating shaft 15 has a motor shaft 15 b integrally provided at a lower portion thereof, and is directly connected to the motor unit 3. A vertical suction pipe 17 is connected to the suction port 14 of the fixed scroll 5 through the closed container 1 from above, and the upper space 1a in which the discharge port 10 is opened is formed through the passages 18a and 18b in the middle. It communicates with the space 1b. The middle space 1b has a discharge pipe 19 that penetrates the sealed container 1 from the side.

The middle space 1b and the lower space 1f are
Passages 20a, 20b, 20c, 20d between the motor stator 3a and the inner wall of the closed casing 1 and the motor stator 3
a and a motor rotor 3b through a gap.
9a and 9b are a balance weight and a sub-weight for canceling the centrifugal force generated by the orbiting movement of the orbiting scroll 6, respectively. Further, between the suction pipe 17 and the fixed scroll 5, an O-ring 21 for sealing the high pressure portion and the low pressure portion is provided.

On the back surface of the end plate of the orbiting scroll 6, a back pressure chamber 23 surrounded by the compressor unit 2 and the frame 11 is formed. A pressure intermediate between the suction pressure and the discharge pressure is introduced through the hole 6d, and gives the orbiting scroll 6 an applied force in the axial direction pressing the fixed scroll 5 against the orbiting scroll 6.

The oil 24 is stored at the bottom of the closed vessel 1 and is supplied to the oil suction pipe 15d by a differential pressure between the high pressure in the closed vessel 1 and the intermediate pressure in the back pressure chamber 23. After being sucked up, one is fed up the central hole 50 in the rotary shaft 15 to the slewing bearing 32, and the other is fed from the auxiliary bearing 26 to the main bearing 27 which is a cylindrical roller bearing via the lateral hole 51. The oil 24 supplied to each bearing is injected into the compression chamber 8 of the scroll wrap through the back pressure chamber 23, mixed with the compressed gas, and then discharged to the upper space 1a together with the discharge gas. Reference numeral 28 denotes an oil level 24d of the oil 24 stored at the bottom.
Fig. 3 shows an oil plate for preventing forming formed thereon.

As shown in FIG. 4, in the first embodiment, the eccentric shaft has a phase angle of about 90 degrees with respect to the load direction acting on the eccentric shaft 15a of the slewing bearing 32. An axially parallel groove (hereinafter simply referred to as a “groove”) 54 cut out in a crescent shape in section on the 15a surface is formed, and its depth L1 is about 2 to 2.5 × 10 Set to ^-3 . Conventional dimensions are 1.5 × 10 ^-3 due to air-conditioning specifications
In the case of the same viscosity, it is possible to increase the amount of lubrication by the cube of the numerical value. That is, the bearing gap and the groove are formed as the oil supply passage.

On the other hand, the rotating shaft 15 engaged with the auxiliary bearing 26
A groove 53 is formed in the same axial direction as the groove 54 parallel to the axial direction provided on the surface of the eccentric shaft 15a. The depth L2 of the groove 53 is about 2.5 to 3 × 1 with respect to the shaft diameter ds.
0 ^-3 is set to the front and rear. Even when the lubricating differential pressure is as small as ² kg / cm ² , the bearing gap is set wide, in other words, the lubricating passage is enlarged, eliminating the oil shortage, which was a conventional problem, and causing the seizure of the bearing. Is to be prevented beforehand.

FIGS. 2 to 9 show a second embodiment.
FIG. 2 shows a vertical sectional view and a lubrication system diagram of an oil injection type hermetic scroll compressor for helium according to the present invention. FIG. 3 is a partial cross-sectional view in which the periphery of the rotation shaft in FIG. 2 is enlarged. This embodiment will be described with reference to FIGS.

In the second embodiment shown in FIG. 2, the working gas is helium gas, and an oil injection pipe 31 for supplying oil for cooling the working helium gas is provided.
It penetrates through the closed container 1 from above and is connected to an oil injection port 22 provided in the end plate portion 5a of the fixed scroll 5, and the opening of the oil injection port 22 is connected to the wrap 6 of the orbiting scroll 6.
b.

In FIG. 2, a compressor unit 2 is accommodated in an upper part of a closed container 1 and a motor unit 3 is accommodated in a lower part. The inside of the closed container 1 is divided into an upper space 1a, a middle space 1b, and a lower space 1f. In the compressor section 2, the fixed scroll 5 and the orbiting scroll 6 are engaged with each other,
A compression chamber 8 is formed.

The fixed scroll 5 has a disk-shaped end plate 5a.
And a wrap 5b which stands upright and is formed into an involute curve or a curve approximating the same, and has a discharge port 10 at the center and a suction port 14 at the outer periphery. The orbiting scroll 6 has a disk-shaped end plate 6a and a wrap 6 which stands upright and has the same shape as the wrap of the fixed scroll.
b, and a boss 6c formed on the opposite side of the end plate from the lap.

The frame 11 has an auxiliary bearing 26 at the center,
The main bearing 27 is formed, and the rotating shaft 15 is supported by these bearings. The eccentric shaft 15 a at the tip of the rotating shaft 15 is connected to the boss 6.
c is inserted so as to be able to perform a turning motion. The fixed scroll 5 is fixed to the frame 11 by a plurality of bolts. The orbiting scroll 6 is supported on the frame 11 by an Oldham mechanism 12 including an Oldham ring and an Oldham key. It is configured to make a turning motion without rotating.

The rotating shaft 15 has a motor shaft 15 b integrally formed at the lower part thereof and is directly connected to the motor unit 3. A vertical suction pipe 17 is connected to the suction port 14 of the fixed scroll 5 through the closed container 1 from above, and the upper space 1a in which the discharge port 10 is opened is formed through the passages 18a and 18b in the middle. It communicates with the space 1b. The middle space 1b has a discharge pipe 19 that penetrates the sealed container 1 from the side.

The middle space 1b and the lower space 1f are
Passages 20a, 20b, 20c, 20d between the motor stator 3a and the inner wall of the closed casing 1 and the motor stator 3
a and a motor rotor 3b through a gap.
9a and 9b are a balance weight and a sub-weight for canceling the centrifugal force generated by the orbiting movement of the orbiting scroll 6, respectively. Further, between the suction pipe 17 and the fixed scroll 5, an O-ring 21 for sealing the high pressure portion and the low pressure portion is provided.

As shown in FIG. 3, a back pressure chamber 23 surrounded by the compressor unit 2 and the frame 11 is formed on the back surface of the end plate of the orbiting scroll 6. An intermediate pressure between the suction pressure and the discharge pressure is introduced through the small holes 6d formed in the end plate, and gives the orbiting scroll 6 an axial force to press the fixed scroll 5 against the orbiting scroll 6.

The oil 24 is stored at the bottom of the closed container 1 and is supplied to the oil suction pipe 15d by a differential pressure between the high pressure in the closed container 1 and the intermediate pressure in the back pressure chamber 23. After being sucked up, one is fed up the central hole 50 in the rotary shaft 15 to the slewing bearing 32, and the other is fed from the auxiliary bearing 26 to the main bearing 27 which is a cylindrical roller bearing via the lateral hole 51. The oil 24 supplied to each bearing is injected into the compression chamber 8 of the scroll wrap through the back pressure chamber 23, mixed with the compressed gas, and then discharged to the upper space 1a together with the discharge gas. Reference numeral 28 denotes an oil level 24d of the oil 24 stored at the bottom.
Fig. 3 shows an oil plate for preventing forming formed thereon.

An oil take-out pipe 30 for taking out the oil 24 at the bottom of the hermetically sealed container 1 is provided on the bottom side surface.
An oil injection pipe 31 for injecting oil into the compression chamber 8 in the middle of the compression of the compressor unit 2 is provided at an upper part of the closed casing 1. The oil injection pipe 31 is connected to the oil injection port 22 formed in the end plate 5 a of the fixed scroll 5.
Through the compression chamber 8.

The oil discharge pipe 30 and the oil injection pipe 31 are provided with an oil cooler 33, and an oil pipe 36,
36a, the throttle part 271 and the oil pipe 36b. With the above configuration, when the motor shaft 15b directly connected to the motor rotor 3b rotates and the eccentric shaft 15a rotates eccentrically, the orbiting scroll 6 performs a orbiting motion via the orbiting bearing 32. Due to this swirling motion, the compression chamber 8 gradually moves to the center and the volume decreases.

The working gas enters the suction chamber 5f from the suction pipe 17 via the suction port 14, and the oil 24 lubricating the bearings flows from the frame chamber 11f on the outer peripheral portion of the orbiting scroll head plate of the orbiting scroll 6 through a minute gap or the like. 5f and mixed with the working gas. The working gas containing the oil 24 passing through the bearing and the oil 24 injected from the oil injection port 22 is compressed in the compression chamber 8 and
Is discharged into the upper space 1a and flows into the middle space 1b through the passages 18a and 18b.

The solid arrows indicate the flow of the working gas, and the broken arrows indicate the flow of the oil 24. Narrow passage 18
a, the working gas and the oil 24 flowing into the middle space 1b of the large space from the 18b rapidly decrease the flow velocity and change the flow direction, so that most of the oil 24 contained in the gas is separated, A part of the working gas passes through the passage 20d facing the passages 18a and 18b and the lower space 1f, and again passes through the passage 20a.
a, 20b, and 20c ascend and flow out of the discharge pipe 19.

The oil 24 is supplied to the passage 2 on the outer periphery of the motor rotor 3b.
It flows down through Oa, 20b, 20c, 20d and remains at the bottom of the closed vessel 1. Oil 2 stored at the bottom of closed container 1
4 is an oil discharge pipe 30 formed by a pressure difference between a high pressure in the closed vessel 1 and an intermediate pressure in the compression chamber 8 related to the oil injection port 22.
From the inflow portion 30a into the oil discharge pipe 30.
The oil that has flowed into the oil discharge pipe 30 reaches the oil cooler 33 through the oil pipe 36, and is appropriately cooled here.
a, 36b, the oil injection pipe 31, and the oil injection port 22 to be injected into the compression chamber 8.

The oil 24 injected into the compression chamber 8 has a function of cooling the working gas in the compression chamber 8 and lubricating a sliding portion such as a scroll wrap tip. After being compressed together with the working gas, the oil 24 is discharged from the discharge port 10 to the upper space 1 a, separated from the working gas in the middle space 1 b, and accumulated at the bottom of the closed container 1 as described above.

The oil supply to the slewing bearing 32, the auxiliary bearing 26, and the main bearing 27 is performed by the differential pressure between the high pressure in the closed vessel 1 and the intermediate pressure in the back pressure chamber 23, and the oil suction pipe 15d and the rotating This is performed via an oil supply passage in the shaft 15. Reference numeral 78 denotes a discharge gas thermostat mounted on the outer wall surface of the sealed container 1. Reference numeral 79 denotes a discharge gas thermostat mounted on the outer wall surface of the discharge pipe 19.

FIGS. 4 to 8 show a second embodiment of the rotary shaft 15 having a differential pressure oil supply structure. As shown in FIG. 4, on the bearing surface where the phase angle is advanced by about 90 degrees with respect to the load direction acting on the eccentric shaft 15a of the slewing bearing 32,
A groove 54 parallel to the axial direction is formed on the surface of the eccentric shaft 15a, and its depth L1 is set to about 2 to 2.5 × 10 ⁻³ in proportion to the shaft diameter dm. Conventional dimensions are 1.5 × 10
^-3 or less, and in the case of the same viscosity, it is possible to increase the lubrication amount by the cube of the numerical value. That is, the bearing gap and the groove are formed as the oil supply passage.

On the other hand, an axially parallel groove 53 formed in the same direction as the axially parallel groove 54 provided on the eccentric shaft 15a is formed on the shaft surface relating to the auxiliary bearing 26. The depth L2 of the groove 53 is about 2.5 to 3 ×
Set around 10 ^-3 . Even when the lubrication differential pressure is as small as ² kg / cm ² , the bearing clearance is set wide for helium applications, in other words, the lubrication passage is expanded, eliminating the conventional oil shortage and preventing bearing seizure accidents Is what you do.

As shown by the broken line in FIG. 4, the oil 24 passes through the central hole 50, and a part of the oil 24 passes through the lateral hole 51 to the axial parallel groove 53 and the peripheral bearing gap by differential pressure. Inflow,
Move to main bearing 27. Next, the periphery of the balance weight 9a is wet to reach the back pressure chamber 23. On the other hand, the oil in the eccentric shaft 15a reaches the space 6v (see FIG. 3) on the bottom surface of the boss 6c, flows into the axial parallel groove 54 and the surrounding bearing gap in the direction of the arrow, and Is discharged.

Here, in the present invention, L1 / dm <L2 /
ds. If dm = ds, L1
<L2. When the amount of oil supplied to the auxiliary bearing 26 is increased with respect to the slewing bearing 32, the oil promotes a cooling effect on the upper main bearing 27, and the oil film thickness of the roller portion is increased, thereby reducing the wear. can get. Thus, the life of the main bearing 27 can be greatly extended.

FIG. 9 is an explanatory diagram showing the operation and effect of the present invention. In the low operating pressure ratio condition range where the pressure ratio is around 2, in contrast to the oil supply characteristic indicated by a broken line in the conventional machine, the oil supply characteristic indicated by a solid line is approximately doubled in the present invention, and the lower limit of the operating pressure ratio range is lower. As a result, there is an effect that the operating pressure ratio range is widened.

The embodiments after FIG. 10 are the third embodiment. In FIG. 10, an oil outlet pipe 30 is provided in a body portion 1u of a bottom cap 1d, and an oil outlet pipe 30 is integrally provided with a joint section 30c serving as a connection port between an oil suction pipe section 30b and an oil pipe 36, and an inflow section of the oil suction pipe section 30b. 30a is directed upward as shown in FIG. 10, and the position of the tip is the pivot bearing 32, the frame 1
The lower end of the oil suction pipe 15d provided at the lower end of the rotary shaft 15 for oil supply to the auxiliary bearing 26 at the lower end is located above the lowermost end. The difference between the dimensional positions is indicated by symbol m1.

The height of the bottom cap 1d is, for example, H1 = 4
3 mm, the height of the oil discharge pipe 30 is H2 = 26 mm, m1
= 20 mm. For example, chamber inner diameter D
H1 / Dc = 0.25 with respect to c or H2 / Dc
Dc is set around 0.15.

FIG. 11 is a partial longitudinal sectional view in which the periphery of the oil discharge pipe 30 is enlarged in a state where the compressor is inclined, for example, by about 10 degrees and the oil level 24d is abnormally lowered. 11
Reference numerals 2 and 113 denote anti-vibration support means for supporting the feet 122 of the compressor. Reference numeral 110 denotes a support table on the unit side.

Even if the position of the oil surface 24d of the oil 24 is in the state shown in FIG. 11, the auxiliary bearing 26, the main bearing 27 and the slewing bearing 3
Refueling to 2 will not be stopped. Therefore, seizure of the bearing portion is prevented. In that case, the gas escapes from the oil extraction pipe 30, and the cooling oil is not supplied to the oil injection pipe 31. For this reason, although the gas temperature in the compression chamber 8 rises abnormally, the abnormal gas temperature is detected by the discharge gas thermostats 79 and 78, and the compressor is stopped before the auxiliary bearing 26, the main bearing 27 and the slewing bearing 32 are seized. can do.

As described above, FIG. 11 shows that the inflow portion 30a facing upward from the oil outlet pipe 30 serving as the oil outlet portion is
Even if is inclined about 10 degrees in the front-back direction, the position of the tip is
This is an embodiment showing that the oil suction pipe 15d provided at the lower end of the rotary shaft 15 is located above the lowermost end of the oil suction pipe 15d.

FIG. 12 is a sectional view taken along the line AA of FIG.
FIG. 14 is a sectional view taken along the line BB of FIG. 2, and FIG.
It is C sectional drawing. 14, an oil plate 28 is provided on the inner wall surface of the casing 1e of the compressor between the lower end of the electric motor unit 3 and the oil outlet pipe 30 serving as an oil outlet, and is guided to the bottom chamber 1u of the oil plate 28. Oil passages 28b, 28c are provided on passages 20a, 20b, 20 provided on the outer peripheral portion of motor stator 3a.
It is set to a circumferential position that does not face the passage 20d through which the oil 24 and the gas flow downward in the positions of c and 20d.

As shown in FIGS. 12 and 13, the passage 20d
Are in the vertical direction of the passages 18a and 18b on the outer edge of the frame 11. The hole 28a at the center is connected to the oil suction pipe 15d.
Is a hole through which The size of the area S1 of the oil passages 28b and 28c of the oil plate 28 is set to be equal to or greater than the size of the cutout area S2 for the passage provided on the outer peripheral portion of the electric motor stator 3a.

In the case of a helium compressor, the refrigerant Freon 22
As described above, the helium gas does not dissolve in the oil 24, so that the oil 24 is not diluted by the refrigerant, and the oil viscosity is several times higher. For this reason, in order to smoothly return the oil 24 dropped from the passage 20d and accumulated on the oil plate 28 to the bottom chamber portion, the passage area is reduced so that the passage resistance can be greatly reduced. This is larger than in the case of the structure of the plate 28. For example, S1 / S2
Is set to about 1.3 to 1.5 times to secure a large size of the oil passages 28b and 28c.

[0046]

According to the present invention, there is an effect that the reliability of the compressor can be greatly improved, the operating pressure ratio range can be expanded as compared with the conventional compressor, and the usability of the compressor is improved. Further, there is an effect that the cooling action to the main bearing is promoted, and the life of the main bearing can be greatly extended.

Further, the lubrication of the bearing portion is ensured, the reliability of the compressor can be further greatly improved, and the axial dimension of the bottom chamber can be set small, so that the compressor can be reduced in size and weight. . In particular, in a bearing portion having a differential pressure lubrication structure, lubrication is ensured even under a low-pressure pressure ratio condition, and accordingly, a seizure accident of the bearing portion is less likely to occur.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a hermetic scroll compressor according to the present invention.

FIG. 2 is a vertical sectional view and a lubrication system diagram showing a second embodiment of the oil injection type closed scroll helium compressor of the present invention.

FIG. 3 is an enlarged partial cross-sectional view of a portion around a rotation shaft of FIG. 2;

FIG. 4 is a front view of a rotating shaft.

FIG. 5 is a diagram viewed from a direction C in FIG. 4;

FIG. 6 is a sectional view taken along line AA of FIG. 4;

FIG. 7 is a sectional view taken along line BB of FIG. 4;

FIG. 8 is a plan view of a rotation shaft.

FIG. 9 is an explanatory diagram showing an effect of the present invention.

FIG. 10 is an enlarged partial longitudinal sectional view of the periphery of an oil extraction pipe in FIG. 2;

FIG. 11 is an enlarged partial longitudinal sectional view of the periphery of an oil discharge pipe when the compressor is inclined.

FIG. 12 is a sectional view taken along line AA of FIG. 2;

FIG. 13 is a sectional view taken along line BB of FIG. 2;

FIG. 14 is a sectional view taken along line CC of FIG. 2;

FIG. 15 shows a prior art bottom chamber structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Closed container 1a ... Upper space 1b ... Middle space 1d ... Bottom cap 1e ... Casing 1f ... Lower space 1u ... Body part 2 ... Compressor part 3 ... Electric motor part 3a ... Electric motor stator 3b ... Electric motor rotor 5 ... Fixed scroll 5a ... End plate 5b Lap 5f Suction chamber 6 Orbiting scroll 6a End plate 6b Lap 6c Boss 6v Space 9a Balance weight 9b Sub weight 10 Outlet 11 Frame 11f Frame chamber 12 Oldham mechanism 14 Suction port 15 ... Rotating shaft 15a ... Eccentric shaft 15b ... Electric motor shaft 15d ... Oil suction pipe 17 ... Suction pipe 18a, 18b ... Path 19 ... Discharge pipe 20a, 20b, 20c, 20d ... Path 21 ... O-ring 22 ... Oil injection Port 23 ... Back pressure chamber 24 ... Oil 24d ... Oil level 26 ... Auxiliary bearing 27 ... Main bearing 271 ... Throttle section 28 ... Oil Plate 28a ... Hole 28b ... Oil passage 28c ... Oil passage 30 ... Oil extraction pipe 30a ... Inflow section 30b ... Oil suction pipe section 30c ... Coupling section 31 ... Oil injection pipe 32 ... Slewing bearing 33 ... Oil cooler 36,36a, 36b ... Oil piping 53,54 ... Groove 78,79 ... Discharge gas thermostat 110 ... Support table 112,113 ... Vibration isolation support means 122 ... Feet

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H029 AA02 AA14 AA21 AB04 BB01 BB12 BB50 CC16 CC17 CC22 CC33 CC48 3H039 AA03 AA04 AA12 BB05 BB11 BB13 CC10 CC12 CC19 CC27 CC42 CC48

Claims (5)

[Claims] 1. A compressor unit and an electric motor unit are housed in a closed container, and the compressor unit is provided with a fixed scroll and an orbiting scroll in which a spiral wrap is erected on a disk-shaped end plate with the wraps inside each other. Engagement, engaging the orbiting scroll with the eccentric mechanism connected to the rotating shaft, and orbiting the orbiting scroll with respect to the fixed scroll without rotating, and the fixed scroll has an opening at the center and an opening at the outer periphery. A suction port is provided, a working gas is sucked from the suction port, the working gas is moved around the compression chamber formed by both scrolls, the volume is reduced to compress the working gas, and the compressed gas is discharged from the discharge port into the container chamber. The working gas is further discharged to the outside of the vessel via a discharge pipe, and further includes a swivel bearing, a main bearing, and an auxiliary bearing with respect to the rotating shaft, and a compressor is provided on a back surface of the end plate of the orbiting scroll. Department and Forming a back pressure chamber surrounded by a frame, drilling a hole in the end plate of the orbiting scroll in the back pressure chamber,
A sealed scroll in which an intermediate pressure between the suction pressure and the discharge pressure is introduced, and oil in an oil reservoir is supplied to the various bearing portions and the compression chambers via an oil suction pipe by a differential pressure between the discharge pressure and the intermediate pressure. In the compressor, on a bearing surface where a phase angle advances by about 90 degrees with respect to a load direction acting on the eccentric shaft portion of the slewing bearing portion, the eccentric shaft surface engaging with the slewing bearing portion is parallel to the axial direction. And a groove parallel to the axial direction is formed on the rotating shaft surface that engages with the auxiliary bearing portion, and a groove depth with respect to a shaft diameter on the auxiliary bearing portion side is on the side of the slewing bearing portion. A hermetic scroll compressor characterized in that the groove depth is set large with respect to the shaft diameter. 2. The working gas is helium gas. In order to cool the working helium gas, an oil injection pipe for supplying oil taken out from a bottom side surface of the closed vessel having the oil reservoir is passed through the closed vessel. The fixed scroll is connected to an oil injection port provided on a head portion of the fixed scroll, and an opening of the oil injection port is opened to face a wrap tooth surface of the orbiting scroll. Item 2. A hermetic scroll compressor according to Item 1. 3. A groove depth L1 of an axially parallel groove formed on an eccentric shaft surface engaged with the slewing bearing portion is set to be about 2 to 2.5 in a ratio with respect to a diameter dm of the eccentric shaft portion. Set to × 10 ^-3 ,
A groove depth L2 of an axially parallel groove formed on the rotating shaft surface engaged with the auxiliary bearing portion is set to about 2.5 to 3 × 10 ^-3 in proportion to a shaft diameter ds. The hermetic scroll compressor according to claim 1 or 2, wherein: 4. The working gas is helium gas, and in order to cool the working helium gas, an oil injection pipe for supplying oil taken out from a bottom side surface of the closed vessel having the oil reservoir penetrates the closed vessel. The fixed scroll is connected to an oil injection port provided on the end plate portion of the fixed scroll, and the opening of the oil injection port is opened to face the wrap tooth tip surface of the orbiting scroll, and the oil outlet is formed as one oil outlet. An oil extraction pipe is provided on the bottom side surface of the closed vessel, which is integrally provided with a joint section serving as a connection port between the oil suction pipe section and the external pipe. The inflow section of the oil suction pipe section faces upward, and the position of the tip section is The hermetic scroll compressor according to any one of claims 1 to 3, wherein the oil suction pipe is located above a lowermost end of the oil suction pipe. 5. An oil passage is provided between the lower end of the electric motor unit and the oil outlet pipe serving as the oil outlet on the inner wall surface of the closed vessel, and leads to a bottom chamber of the oil plate. Is set at a circumferential position that is not opposed to a position of a downward gas and oil passage provided on an outer peripheral portion of a stator of the electric motor unit, and an oil passage area of the oil plate is set to a stator of the electric motor unit. The hermetic scroll compressor according to any one of claims 1 to 4, wherein the size is set to be equal to or greater than the passage area provided in the outer peripheral portion of the scroll compressor.