JPS639693A - Scroll compressor - Google Patents

Abstract

PURPOSE:To certainly lubricate a bearing even by the lubricating oil containing solvent by suppressing the rise of the bearing temperature by selecting the bearing gap between a swing scroll shaft and the bearing and the bearing gap between a main shaft large diameter part and the bearing. CONSTITUTION:When the outside diameter of a swing scroll shaft 2c is d1, and the inside diameter of a swing scroll bearing 17 is D1, the bearing gap delta1 is set so that delta1>=2d1/1000, and when the outside diameter of the outer periphery 62a of the large diameter part 6a of a main shaft 6 is d2, and the inside diameter of a main bearing 18 is D2, the bearing gap delta2 is set so that delta2>=1.3d2/1000. With such constitution, even if the lubricating oil containing the dissolved solvent is used, the bearing temperature does not rise so much, and generation of seizure between the shafts 2c and 6 and the bearing is prevented. Therefore, the scroll compressor having high reliability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a scroll compressor used in a compressor using refrigerant.

[Conventional technology]

Fig. 4 shows the basic components and pressure principle when a scroll fluid machine is used as a compressor.
3 is a suction chamber, 4 is a discharge boat, and 5 is a compression chamber. Further, O is the center of the fixed scroll 1.

The fixed scroll 1 and the swinging scroll 2 have spirals 1a and 2a having the same shape and opposite winding directions, and the shapes of these spirals 1a and 2a are as conventionally known.
It is composed of two arcs of inzelute curves, etc.

Next, the operation will be explained. The fixed scroll 1 is stationary with respect to space, and the oscillating scroll 2 is assembled with a phase shift of 1800 degrees relative to the fixed scroll 1, and performs an orbital motion that does not rotate around the center 0 of the fixed scroll 1. As shown in Figure (a) - ((O<O
', 90°, 180°, 270°. In the figure, gas confinement in the suction chamber 3 is completed in the 0° state shown in FIG. 4(a), and a compression chamber 5 is formed between the spirals 1a and 2a. As the orbiting scroll 2 moves, the compression chamber 5 gradually reduces its volume, and the gas therein is compressed and discharged through the discharge port 4 provided at the center of the fixed scroll 1.

The outline of the device known as a scroll compressor is as above.

Next, the specific configuration and operation of the scroll compressor will be explained. FIG. 5 shows the configuration of an embodiment of the scroll compressor shown in, for example, Japanese Patent Application No. 59-64571. In particular, it shows a specific example of the scroll compressor applied to a totally hermetic refrigerant compressor. This is an example. In the figure, 1 is a fixed scroll with a spiral 1a on one side of the base plate 1b, 2 is an oscillating scroll with a spiral 2a on one side of the base plate 2b, 3 is a suction port (suction chamber), and 4 is a The discharge port 5 has both spirals la and 2 when both spirals 1a and 2at are combined with each other.
6 is a main shaft; 7 is an oil cap mounted to shoulder the suction lower a and covers the lower end of the main shaft with a predetermined gap between the lower end of the main shaft; 8.9 is a bearing frame; 10 is a A motor rotor, 11 is a motor stator, 12 is a shell, 13 is an Oldham joint, 14 is an oil reservoir provided at the bottom of the shell 12, 15 is a suction pipe, 16 is a discharge pipe, 17 is eccentric with respect to the main shaft 6, and a stand The oscillating scroll bearing is fitted through a small gap with the oscillating scroll shaft 2C provided on the other side of the plate 2b, and is fixed in the eccentric hole 60a formed in the large diameter portion 6a at the upper end of the main shaft 6. There is. 18 is a first main bearing which supports the outer circumferential surface 61ae of the upper large diameter portion 6a of the main shaft 6 and is fitted with a slight gap; 19 is a second main bearing which supports the smaller diameter portion 6bi of the lower part of the main shaft 6. A bearing 20 is a first thrust bearing that supports the oscillating scroll 20 from the axial direction of the lower surface 20bt of the base plate 2b, and is a bearing adjacent to the first main bearing 19 so as to support the center side of the base plate 2b. It is provided on the frame 8. A second thrust bearing 21 is provided in the bearing frame 9 and supports the stepped portion 6C between the large diameter portion 6a and the small diameter portion 6b of the main shaft 6 in the axial direction. 22
is a first oil supply hole which has an opening 22a at the lower end of the main shaft 6 and is eccentrically provided in the main shaft 6 with respect to its axis.
7. It is connected to the 19th section. 24 is a gas vent hole provided in the main shaft 6, 25.26 is an oil return hole for the oil path, 27.
28 is a communication hole for the suction gas path.

Here, in the oscillating scroll 2, the oscillating scroll shaft 2C is engaged with the main shaft 6 via the oscillating scroll bearing 17 while being engaged with the fixed scroll 1, and the oscillating scroll shaft 2C is engaged with the main shaft 6 via the oscillating scroll bearing 17, and the oscillating scroll shaft 2C is engaged with the main shaft 6 through the oscillating scroll bearing 17 and the bearing frame 8. It is supported by a first thrust bearing 21 provided therein. Furthermore, the main shaft 6
Bearing frames 8.9 connected to each other with dowels etc.
A first main bearing 18. The second main bearing 19° is supported by a second thrust bearing 20.

Furthermore, the Oldham joint 13 is disposed between the oscillating scroll 2 and the bearing frame 8, and is configured to completely prevent the oscillating scroll 2 from rotating on its axis and to allow only revolution movement. , the fixed scroll 1 has a bearing frame 8
, 9 are collinear with Zelt et al. Further, the motor/rotor 10 is press-fitted into the main shaft 6, and the motor/stator 11 is press-fitted into the bearing frame 9.

It is fixed with burnt ash or screws. Furthermore, the oil gap 7 is press-fitted into the main shaft 6.

It is fixed with incinerated ash etc. The mechanism assembled in this way is housed and fixed in the shell 12 by press fitting, burning ashes, etc., with the fixed and oscillating scroll 1.2 at the top and the motor rotor and stator 10.11 at the bottom. .

Next, the operation of the scroll compressor configured as described above will be explained. When the motor rotor 10 rotates, the oscillating scroll 2 begins to revolve through the main shaft 6 and the Oldham joint 13 while being prevented from rotating, and compression begins according to the operating principle explained in FIG. 4. At this time, the refrigerant gas is sucked into the shell 12 through the suction pipe 16, and as shown by the solid line arrow, the refrigerant gas is passed through the communication hole 27 between the bearing frame 9 and the motor stator 11, and between the motor rotor 10 and the motor stator 1.
After passing through the air gap between the shell 12 and the bearing frames 8 and 9 to cool the motor, the motor passes through the communication hole 28 between the shell 12 and the bearing frames 8 and 9, and enters the compression chamber 5 from the suction port 3 provided in the fixed scroll 1. Captured and compressed. The compressed gas is discharged from the compressor through the discharge boat 4 and the discharge pipe 16. Further, the lubricating oil is supplied to the oil cap 7 by centrifugal pump action by the oil cap 7 disposed on the main shaft 6 and the first oil supply hole 22 as shown by the broken line arrow from the oil reservoir 14.
each bearing 17 through the suction lower a and the first oil supply hole 22.
, 19', and bearings 18, 2 from bearing 17.
Refueling is done in the order of 0.21. The oil used for lubrication mainly flows through oil return holes 25 and 26i provided in the bearing frames 8 and 9.
and is returned to the oil sump 14. Further, the gas vent hole 24 provided in the main shaft 6 is for quickly discharging the gas in the oil cap 7 to the outside of the shaft during operation, thereby increasing pump efficiency.

Next, a more detailed explanation of the oil supply system portion of such a compressor will be given with reference to FIG. That is, FIG. 1 is a partial cross-sectional view showing the structure of the upper part of the main shaft 6, in which reference numeral 30 indicates the swinging shaft of the swinging scroll 2, the lower end surface 20c of the roll shaft 2c, the swinging scroll bearing 17, and the eccentric hole. The first oil supply hole 22 has an opening of the bottom surface 600aKI1m of the eccentric hole 60a in the first space formed by the bottom surface 600a of the eccentric hole 60a.
It communicates with 31 is located on the inner peripheral side of the thrust bearing 2o, and is located on the lower surface 20b of the base plate 2b of the swinging scroll 2.
and a second space formed by the upper end surface 61a of the large diameter portion 6a of the main shaft 6; 32, a bearing frame 8, a recess 8a and an oscillating scroll 2 on the outer peripheral side of the first thrust bearing 20;
An eighth space 33 (shown in FIG. 5) formed by the base plate 2b is located on the inner peripheral surface of the oscillating scroll bearing 17, and a first space 33 is formed from the lower end surface to the vicinity of the upper end surface. It is an oil groove, and its lower end communicates with the first space 3o. 34
is located on the outer circumferential surface 62a side of the large diameter portion 6a of the main shaft 6 and the main bearing 1
The upper end of the second oil groove is formed on the sliding surface of the main bearing 8 and the second oil groove communicates with the second space 31, and the lower end thereof extends to the vicinity of the lower end of the main bearing 18. 35 is the first and second oil groove 33, 34t
The second oil supply hole % 20a is the thrust bearing 2
A plurality of 30th radial oil grooves are provided on the sliding surface side of the oscillating scroll 2, one end of which is connected to the second space 31 and the other end is connected to the oil return hole through the third space 32. 25 (shown in Figure 5). In this way, the first oil supply hole 22,
a first space 30, a tenth oil groove 33, a second oil supply hole 35,
Second oil groove 34, second space 31, third oil groove 20a
Since a series of oil supply paths are formed, the lubricating oil pumped up by the action of the centrifugal pump flows as shown by the broken line arrow and is discharged to the oil return hole 25 side via the third space 32 (the fifth (shown in figure). The subsequent oil path is the same as explained in FIG. 5, so the explanation thereof will be omitted.

Next, the bearing structure will be explained in more detail with reference to FIG.

The oscillating scroll shaft 2c and the oscillating scroll bearing 17 are fitted with a small gap between them, and although this gap varies somewhat depending on the viscosity of the lubricating oil and the rotational speed of the shaft, it is usually d/ which provides the minimum frictional work. I use it around 1o00.

d is the diameter of the glaze. Therefore, the oscillating scroll shaft 2
The diameter of the oscillating scroll bearing 17 is d, and the diameter of C is d.
t, the bearing gap δ created when these are fitted together at nine o'clock is
1 is set so that approximately δt = Dt d+ = d, /1000.

The outer peripheral surface 62a of the large diameter portion 6a of the main @6 and the main bearing 18
Similarly, the diameter of the large diameter portion 6a is d2, and the main bearing 1 is
80 If the inner diameter is 8, the bearing gap δ2 is approximately δ2=D2
It is set so that dt=dy/'1000.

[Issues on which the invention is based]

Conventional scroll compressors are configured as described above, so when used as a refrigerant compressor, for example, a phenomenon occurs where the refrigerant dissolves into the oil at the bottom of the shell, diluting the oil and reducing the viscosity of the oil. do. For this reason, the thickness of the oil film on the bearing portion decreases, and if the oil film is excessively diluted, the oil film will run out and the shaft and bearing will come into contact and cause friction. Also, oscillating scroll shaft 2
C has four spirals forming the compression chamber, and because it is close to the discharge port 4, it easily receives heat from compression work, and the rocking bearing also has a volute on the outside thereof (
Heat is difficult to escape because of the outer circumferential surface 62a of the large diameter portion 6a and the main bearing 18). Therefore, there is a problem in that the area near the bearing becomes high temperature, which promotes the contact between the shaft and the bearing, resulting in seizing.

This invention was made to solve the above problems, and even if diluted oil lubricates the bearing, seizure will not occur, and the friction between the shaft and bearing can be minimized. The purpose is to obtain a scroll compressor.

[Means for solving problems]

In the scroll compressor according to the present invention, the bearing diameter gap δ2 between the oscillating scroll shaft and the oscillating scroll bearing is δ2≧d2.

[For production]

In the scroll compressor of this invention, the bearing gap is set as described above, so the diluted oil containing refrigerant lubricates the bearing, and even if the shaft and bearing come into contact, the temperature of the bearing does not rise to the melting point. , it is possible to prevent seizure between the shaft and the bearing.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. Since the configuration of this invention is the same as that shown in FIGS. 1 and 5, explanations of the configuration and operation will be omitted. The difference between this invention and the conventional one lies in the bearing clearance, and the bearing clearance will be explained in detail below. Figure 3 shows the relationship between the temperature near the bearing and the bearing gap, where the vertical axis shows the temperature near the bearing and the horizontal axis shows the bearing gap.6 Also, Figure 2 shows the case when the bearing is lubricated with diluted oil. This is the damage data. ■ on the vertical axis indicates the investigation on the oscillating scroll shaft 2C and the oscillating scroll bearing 17, @ indicates the investigation on the outer periphery of the large diameter portion 6a of the main shaft (6) and the main bearing 18, The horizontal axis shows the bearing clearance. Note that d is the shaft diameter. ■ In Figure 2.

The shaded area at @ represents the area where the bearing has seized up. Judging from this, the bearing temperature can be lowered by widening the bearing gap, and in order to ensure a bearing gap that will not seize, the outer diameter tdt of the oscillating scroll shaft 2C, the inner diameter f Dt of the oscillating scroll bearing 17, Then, the bearing clearance δ
1 (=D1 d□) is δ□≧-2ct.

and the outer diameter t dz of the outer periphery 62a of the large diameter portion 6a of the main shaft 60 and the inner diameter t dz of the main bearing 18, the bearing gap δz (=Dz dz) is set to δ2≧i, 3 ct. It is. According to this, the difference between the former and the latter is thought to be due to heat conduction and heat transfer, and the reason why the latter is smaller is because the heat at the discharge part is conducted through the lubricating oil, so the heat near the bearing is relatively low. It is presumed that this is the case.

When the scroll compressor configured as described above is used for a refrigerant compressor, for example, even if the refrigerant is dissolved in the oil and the bearings are fully lubricated with the diluted oil, the bearing gap is reduced to a second level. Since the temperature is increased to the value shown in the figure, the temperature near the bearing does not rise much, making it possible to prevent seizure between the shaft and the bearing.

Note that, if the values of δl and δ2 are within the ranges shown in FIG. 2, the above-mentioned effect can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the bearing gap δl between the oscillating scroll shaft and its bearing is δl≧−2al, and the bearing gap 5zk1.3 δ2≧−1000′ between the outer diameter of the main shaft large diameter portion and the main bearing As a result, even if the bearings are lubricated with oil diluted with refrigerant dissolved in the oil, the shaft and bearings will not seize, making it possible to obtain a highly reliable scroll compressor. can.

[Brief explanation of the drawing]

Fig. 1 is an enlarged sectional view of the main shaft portion of a scroll compressor according to an embodiment of the present invention, Fig. 2 is data determining the range of the bearing gap, Fig. 3 is a diagram of the relationship between the temperature near the bearing and the bearing gap, FIG. 4 is a diagram showing the basic structure and principle of using a scroll fluid machine as a compressor, and FIG. 5 is a sectional view of the entire scroll compressor. 2... Oscillating scroll, 2C... Oscillating scroll shaft, 6... Main shaft, 5a... Large diameter portion, 8, 9... Bearing frame, 17... Oscillating scroll bearing, 18 ...
Main bearing, 20... Thrust bearing, 62a... Main shaft outer peripheral surface. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A fixed scroll and an oscillating scroll that combine a pair of spirals to form a compression chamber, a main shaft that drives the oscillating scroll through a bearing, and a bearing frame that has a bearing that supports this main shaft. , a motor that drives the main shaft, an oil reservoir at the bottom, and the above-mentioned fixed scroll at the top.
In a low-pressure shell type scroll compressor, the motor is located at the bottom and the oil cap fixed to the lower end of the main shaft is immersed in an oil reservoir.
If the outer diameter of the above-mentioned oscillating scroll shaft is d_1 and the inner diameter of the scroll bearing is D_1, then the bearing gap δ_1 (=D-
d_1) is set to δ_1≧(2/1000)d_1,
In addition, the outer diameter of the large diameter part of the main shaft is d_2, and the inner diameter of the bearing is D_2.
_2, the bearing clearance δ_2 (=D_2-d_1) is δ
A scroll compressor characterized in that _2≧(1.3/1000)d_2.