JPS63117186A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent the mixing of oil into a suction glass and suppress the oil rising phenomenon by forming a plurality of oil grooves onto the surface of a thrust bearing and opening and inner edge onto the inner peripheral part of the thrust bearing and allowing the outer edge to communicate to an oil return hole communicating to the bottom part of a shell through the annular grooves. CONSTITUTION:Annular grooves 21b in concentric form are formed on the surface of a thrust bearing 21, and the outer peripheral side is formed into flat surface, and a plurality of oil grooves 21a which extend in the radial direction and whose outer edge communicates to the annular grooves 21b and whose inner edge communicates to the inner hole part of the thrust bearing 21 are formed on the inner peripheral side. The annular groove 21b communicates to an oil reservoir 15 in the lower part of a sealed shell 12 through a waste oil hole 21c formed on the thrust bearing 21 and an oil return hole 25 formed on a bearing frame 8. Since the oil introduced into the oil groove 21a from the inner hole on the thrust bearing 21 is returned into the annular groove 21b, and is not introduced into the suction part of on the outer peripheral side of the thrust bearing 21, the oil is prevented from being transported into a compression chamber by the inhaled gas, and the oil rising phenomenon in which oil flows outside the compressor can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a scroll compressor used for air compressors, refrigerant compressors, and the like.

[Conventional technology]

FIG. 5 shows a diagram of the operating principle of a scroll compressor. In the figure, 1 is a fixed scroll, 2 is an oscillating scroll, 3 is a suction chamber, 4 is a discharge port, and 5 is a compression chamber. Also, O
is the center of the fixed scroll 1.

The fixed scroll 1 and the oscillating 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 nine involute 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 180 degrees with respect to the fixed scroll 1, and rotates around the center 0 of the fixed scroll 1 without rotating on its own axis. 0° as shown in Figure 1 (4) to (dl).
, 90”, 180°.

In the 0° state shown in FIG. 5 (al), the confinement of the gas in the suction chamber 3 is completed, and the compression chamber 5 is formed in the vortex 1a for 2 days.

As the orbiting scroll 2 moves, the compression chamber 5 gradually reduces its volume, and the gas therein is compressed and discharged from 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. 6 shows a conventional example of a scroll compressor, which is disclosed in Japanese Patent Application Laid-Open No. 58-117380. In particular, it shows a concrete implementation when a scroll compressor is applied to a totally hermetic refrigerant compressor. This is an example. In the figure, 1 is a fixed scroll with a vortex 1a on one side of the base plate 1b, 2 is an oscillating scroll with a vortex S2a on one side of the base plate 2b, 3 is a suction port (suction chamber), and 4 is a Discharge boat, 5 is both warm @la, when 2a is combined with each other, both warm winding la, 2a
A compression chamber is formed in between, 6 is a main shaft, 7 is a suction lower a, an oil cap is attached to cover the lower end of the main shaft 6 with a predetermined gap from the lower end of the main shaft, 8.9 is a bearing frame, The bearing frame 8 has a recessed portion 8a. 10 is a motor rotor, 11 is a motor stator, 12 is a shell, 13 is an Oldham joint, 13a is a key that fits into the groove 2G provided in the swinging scroll 2, 15 is an oil reservoir provided at the bottom of the shell 12, 16 17 is a suction pipe, 17 is a discharge pipe, and 1 is an oscillating scroll bearing eccentric to the main shaft 6 and rotatably fitted into an oscillating scroll shaft 2c provided on the other side of the base plate 2b. It is fixed in an eccentric hole 60a formed in a large diameter portion 6a at the upper end of the main shaft 6. 19 is a first main bearing that supports the outer peripheral surface 61a of the large diameter portion 6a at the top of the main shaft 6; 20 is a second main bearing that supports the small diameter portion 6b at the bottom of the main shaft 6; 21;
22 is a first thrust bearing that axially supports the lower surface 20b of the plywood 2b of the orbiting scroll 2; and 22 is a second thrust bearing that axially supports the stepped portion 6c between the large diameter portion 6a and the small diameter portion 6b of the main shaft 6. The thrust bearing 23 has an opening 2 at the lower end of the main shaft 6.
3a, and is an oil supply hole provided in the main shaft 6 eccentrically with respect to its axis, and communicates with each bearing 18.20. 24
25 and 26 are oil return holes for the oil path, and 27 and 28 are communication holes for the suction gas path. Note that the first thrust bearing 21 is shown in FIG.
(Explaining bl. The outer periphery of the thrust bearing 21 is widened to such an extent that a slight gap is created between the inner wall of the recess 8a of the bearing frame 8, and a part of the outer periphery is provided with an Oldham joint 13.
A notch 21d is provided so as not to obstruct the movement range of the key 13a. In addition, in the center part in the radial direction, there is an annular 111 in the area that always overlaps with the back surface of the oscillating scroll 2.
21b is provided, and has a waste oil hole 21c. Further, an oil groove 21a penetrating inwardly is provided on the surface inside the annular groove 21b.

Here, in the oscillating scroll 2, the oscillating scroll shaft 2c is engaged with the main shaft 6 via the oscillating scroll bearing 18 while being engaged with the fixed scroll 1, and the oscillating scroll shaft 2c is engaged with the main shaft 6 through the oscillating scroll bearing 18 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 19. The second main bearing 20° is supported by a second thrust bearing 21.

Further, the Oldham joint 13 is disposed between the swinging scroll 2 and the recessed portion 8a of the bearing frame 8, and is configured to prevent the swinging scroll 2 from rotating on its own axis and to allow only revolution movement. In this state, the fixed scroll 1 is collinear with the bearing frame 8.9 by bolts or the like. Further, the motor/rotor 10 is attached to the main shaft 6.
The stator 11 is fixed to the bearing frame 9 by press fitting, shrink fitting, screwing, or the like. Furthermore, the oil cap 7 is fixed to the main shaft 6 by press fitting, shrink fitting, or the like. The mechanism section assembled in this manner is housed and fixed in the shell lz by press-fitting, shrink-fitting, etc., with the fixed and oscillating scrolls 1 and 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, and compression begins according to the operating principle explained in FIG. 1. At this time, the refrigerant gas is supplied to the shell 1 from the suction pipe 16.
2 and passes through the communication hole 27 between the bearing frame 9 and the motor/stator 11, the air gap between the motor/rotor 10 and the motor/stator 11, etc. to cool the motor, as shown by the solid arrow. After that, it passes through the communication hole 28 between the shell 12 and the bearing frame 8.9, is taken into the compression chamber 5 through the suction port 3 provided in the fixed scroll 1, and is compressed. The compressed gas passes through the discharge port 4 to the discharge pipe 1
7 and is discharged from the compressor. Also, the lubricating oil is in the oil sump 1.
As shown by the broken line arrow from 5, the oil supplied to each of the bearings 18 to 20 through the suction lower a of the oil cap 7 and the oil supply hole 23 by the centrifugal pump action of the oil camp 7 and the oil supply hole 23 arranged on the main shaft 6 is further The oil reaches the thrust bearing 21 and flows in this order through the oil groove 21a, the annular groove 2lb, and the waste oil hole 21c. The oil used for lubrication is returned to the oil sump 15 mainly through oil return holes 25.26 provided in the bearing frame 8.9.

[Problem that the invention seeks to solve]

Since the conventional scroll compressor is configured as described above, each bearing is lubricated and the waste oil hole 21e of the thrust bearing 21 is filled with oil.
Since the gap between the outer circumferential surface of the thrust bearing 21 and the inner wall surface of the recessed portion 8a is very small, most of the oil that reaches the rich portion 8a of the bearing frame 8 passes through the oil return holes 25 and 26 and enters the oil sump 15. I was trying to get back to it. However, since a notch 21d must be provided on a part of the outer circumference of the thrust bearing 21 so as not to hinder the movement of the key 13a of the Oldham joint 13, and the outer diameter of the thrust bearing 21 is large,
Due to processing, it is not possible to make the gap between the inner wall of the recess 8a very small, so the suction part of the compression chamber 5 and the thrust bearing 21
The recessed portion 8a of the bearing frame 8 partitioned by the compressor was unable to be isolated, and in reality, not only was a considerable amount of oil brought into the suction section of the compression chamber 5, but a large amount of oil was taken out to the circuit outside the compressor. Furthermore, since the thrust bearing 21 is larger than the size required to function as a bearing, there is a problem in that the cost increases.

This invention was made in order to solve the above-mentioned problems, and it is possible to use a scroll compressor with less oil flow by almost no oil used for bearing lubrication being brought into the suction part of the compression chamber. The purpose is to obtain.

[Means for solving problems]

In the scroll compressor according to the present invention, the outer diameter of the thrust bearing is set to be smaller than the outer diameter of the oscillating scroll and overlap the entire circumference of the thrust bearing, and oil is transferred from the thrust bearing to the recessed part of the bearing frame. The oil groove of the thrust bearing is closed at the outer periphery of the bearing surface to prevent oil from flowing, and an oil return hole is provided in the bearing frame to communicate the oil groove with the oil reservoir at the bottom of the shell.

[For production]

In this invention, after lubricating each bearing, the amount of oil that reaches the recessed part of the bearing frame is a small amount that leaks from the bearing gap of the thrust bearing, and most of the oil is returned to the oil reservoir at the bottom of the shell. The oil is discharged into the hole, thereby reducing the amount of oil carried out to the circuit outside the compressor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the cross-sectional view of the scroll compressor shown in the figure, 21 is a thrust bearing, the outer diameter of which is smaller than the outer diameter of the plywood of the oscillating scroll 20, and the thrust bearing surface is the oscillating scroll 20.
The plywood surface is always over-ruffed.

Figure 2+a) is a plan view of the thrust bearing 21, and Figure 2 (bl is a cross-sectional view).A concentric annular groove 21b is formed near the outer circumference on the thrust bearing surface, and a waste oil hole is formed in this groove 21b. 21c are arranged in multiple stages at equal intervals.Furthermore, the annular groove 21
A radial oil groove 21a is formed in the inner circumferential direction from b.

Considering the oil supply to the outer circumferential surface 21a located outward from the annular groove 21b, the annular groove 21b extends from the outer diameter of the orbiting scroll 2.
It is desirable that the distance to 1b be within the orbital diameter of the orbiting scroll, that is, the diameter of the annular groove 21b should be set by d1%.
The outer diameter of the thrust bearing 21 is d! , when the revolution diameter of the orbiting scroll 2 is do, the annular groove diameter d1 is set such that (d* d+)/2<d. Further, the oil groove 21a is not limited to a radial shape, but may be any groove penetrating from the annular groove 21b to the inner circumference.On the other hand, the waste oil hole 21c communicates with the oil return hole 25 of the bearing frame 8, as can be seen from FIG. Bearing frame 8.9
It communicates with a balancer chamber 29 formed by. This balancer chamber 29 has a waste oil hole 27 communicating with the oil reservoir 15. Note that 21f is a thrust bearing surface without an oil groove 21a.

In the scroll compressor configured as described above, the oil sucked up from the oil hole 23 provided in the crankshaft 6 reaches the thrust bearing 21 as shown by the broken line arrow. , oil groove 21a, annular groove 21b, waste oil hole 21C, oil return hole 25° balancer chamber 29. Oil return hole 26. It flows through the thread path of the oil sump 15. The oil brought into the suction section of the compression chamber is the total amount of oil accumulated in the rich portion 8a of the bearing frame 8, but this amount is the total amount of oil that is collected in the rich portion 8a of the bearing frame 8. It is determined by the gap, so it is small.

Therefore, the lubricating oil is hardly brought into the suction section of the compression chamber, so it is possible to reduce the amount of oil flowing out of the compressor.

FIG. 3 (al, (bl) shows another embodiment of the thrust bearing 21. By providing a bypass oil groove 21g penetrating outward from the annular groove 21b, a part of the oil lubricating each bearing is removed. By sending oil to the recess 8a of the bearing frame 8, the necessary amount of oil can be supplied to the suction part of the compression chamber.
1a, the annular groove 21b is on the thrust bearing surface, is open on the inner peripheral edge side, and is not limited in shape as long as it is closed on the outer peripheral edge side. For example, as shown in FIGS. The oil groove 21a may be opened on the inner peripheral edge side and spirally formed outward, and this oil groove may be communicated with the waste oil hole 21c.

〔Effect of the invention〕

As explained above, according to the present invention, the outer diameter of the thrust bearing is smaller than the outer diameter of the oscillating scroll and overlaps the entire circumference of the thrust bearing, so that oil can be transferred from the thrust bearing to the recessed part of the bearing frame. The oil groove of the thrust bearing is closed at the outer periphery of the bearing surface to prevent oil from flowing, and an oil return hole is provided in the bearing frame that communicates the oil groove with the oil reservoir at the bottom of the shell. Almost no oil is brought into the suction section of the compression chamber, reducing the amount of oil flowing out of the compressor, thereby providing a compact scroll compressor with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a scroll compressor according to an embodiment of the present invention, FIGS. .) is a plan view and a sectional view of another embodiment of the thrust bearing, Fig. 5 is a diagram of the operating principle of a scroll compressor, Fig. 6 is a sectional view of a conventional scroll compressor, and Fig. 7 (a). t) is a plan view and a sectional view of a conventional thrust bearing. 1... Fixed scroll, 2... Oscillating scroll, 5
... Compression chamber, 6... Main shaft, 8.9... Bearing frame, 8a... Recessed part, 12... Shell, 13...
Oldham joint, 15...oil sump, 18...bearing, 2
1... Thrust bearing, 21a... Oil groove, 21b...
- Annular groove, 21C... waste oil hole, 25... oil return hole. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A fixed scroll and a seeding scroll that have spiral side plates such as an involute and form a compression chamber by combining the side plates, an Oldham joint and a main shaft that cause an oscillating scroll to oscillate, and an oscillating scroll. A thrust bearing that has an inner circumferential edge and an outer circumferential edge that supports the back surface of the moving scroll and has a lubrication groove on its bearing surface, and a bearing frame that fixes the fixed scroll, houses the Oldham coupling mentioned above, the thrust bearing, and supports the main shaft. In this scroll compressor, the oil groove provided on the thrust bearing surface is opened on the inner peripheral edge side of the thrust bearing surface. The outer circumferential portion of the thrust bearing surface is a flat surface with no oil grooves and overlaps the back surface of the oscillating scroll over the entire circumference. A scroll compressor characterized by forming an oil return hole that communicates an oil groove with the bottom of the shell. (2) An oil groove is provided that communicates the oil groove of the thrust bearing with the Oldham joint storage space of the bearing frame, and by changing the size and number of oil grooves, after lubricating the thrust bearing surface, the oil groove passes through the oil groove and the thrust bearing The scroll compressor according to claim 1, wherein the amount of oil flowing out from the outer periphery is adjusted so that the amount of oil sucked into the compression chamber is an appropriate amount.