JPH0692795B2 - Scroll compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a scroll compressor used for an air compressor, a refrigerant compressor, and the like.

[Prior Art] FIG. 5 is a diagram showing an operation principle of a scroll compressor.

In the figure, 1 is a fixed scroll, 2 is an orbiting scroll, 3 is a suction chamber, 4 is a discharge port, and 5 is a compression chamber.
Further, 0 is the center of the fixed scroll 1.

The fixed scroll 1 and the orbiting scroll 2 have spirals 1a and 2a having the same shape but opposite winding directions, and the shapes of these spirals 1a and 2a are, as is conventionally known, from an involute curve, an arc or the like. It is configured.

Next, the operation will be described.

The fixed scroll 1 is stationary with respect to the space, and the orbiting scroll 2 is combined with the fixed scroll 1 in a phase shift of 180 ° so that the center of the fixed scroll 1 is 0.
Performing an orbital motion that does not rotate around the
As shown in (d), it moves like 0 °, 90 °, 180 °, 270 °. In the figure, at the 0 ° state shown in FIG. 5 (a), the confinement of gas in the suction chamber 3 is completed, and the compression chamber 5 is inserted between the spirals 1a and 2a.
Is formed. Then, with the movement of the orbiting scroll 2, the volume of the compression chamber 5 is gradually reduced, and the gas therein is compressed and discharged from the discharge port 4 provided at the center of the fixed scroll 1.

This is the general operation of the device known in the scroll compressor.

Next, a specific configuration and operation of the scroll compressor will be described.

FIG. 6 shows a conventional example of a scroll compressor, which is disclosed in Japanese Unexamined Patent Publication No. 58-117380. In particular, a concrete example when the scroll compressor is applied to a totally hermetic refrigerant compressor is shown. This is an example.

In FIG. 6, 1 is a fixed scroll having a spiral 1a on one side of a base plate 1b, 2 is an orbiting scroll having a spiral 2a on one side of the base plate 2b, 3 is a suction port (suction chamber), 4 Is the discharge port,
5 is a compression chamber formed between both spirals 1a, 2a when they are combined with each other, 6 is a main shaft, 7 has a suction port 7a, and the lower end of the main shaft 6 has a lower end of the main shaft 6 and a predetermined gap. The oil caps 8 and 9 mounted so as to cover the parts are bearing frames, and the bearing frame 8 has a recess 8a. 10 is a motor rotor, 11 is a motor stator, 12 is a shell, 13 is an Oldham coupling, 13a is a key that fits into the groove 2d provided in the orbiting scroll 2, 15 is an oil sump provided at the bottom of the shell 12, 16
Is a suction pipe, 17 is a discharge pipe, 18 is an oscillating scroll bearing which is eccentric with respect to the main shaft 6 and is rotatably fitted to an oscillating scroll shaft 2c provided on the other side of the base plate 2b. It is fixed in the eccentric hole 60a formed in the large diameter portion 6a at the upper end portion of 6. Reference numeral 19 is a first main bearing that supports the outer peripheral surface 61a of the large diameter portion 6a at the upper end of the main shaft 6, 20 is a second main bearing that supports the smaller diameter portion 6b of the lower portion of the main shaft 6, and 21 is an orbiting scroll 2. A first thrust bearing that axially supports the lower surface 2e of the base plate 2b of
22 is a second thrust bearing that axially supports a step 6c between the large-diameter portion 6a and the small-diameter portion 6b of the main shaft 6, and 23 has an opening 23a at the lower end of the main shaft 6, and the shaft center is inside the main shaft 6. The oil supply holes provided more eccentrically communicate with the bearings 18 and 20. 24 is a gas vent hole provided in the main shaft 6, 25 and 26 are oil return holes for the oil passage, and 27 and 28 are communication holes for the intake gas passage.

Next, the first thrust bearing 21 will be described with reference to FIGS. 7 (a) and 7 (b).

The outer periphery of the thrust bearing 21 is widened to such an extent that a slight gap is formed with the inner wall of the recess 8a of the bearing frame 8, and a cutout 21d is formed in a part of the outer periphery so as not to obstruct the motion range of the key 13a of the Oldham coupling 13. Is provided. Further, an annular groove 21b is provided at a central portion in the radial direction in a region which always overlaps with the back surface of the orbiting scroll 2, and has a waste oil hole 21c. Further, an oil groove 21a penetrating inward is provided on the inner surface of the annular groove 21b.

Here, in the orbiting scroll 2, the orbiting scroll shaft 2c is engaged with the main shaft 6 via the orbiting scroll bearing 18 in a state of being meshed with the fixed scroll 1, and the orbiting scroll bearing 18 and the bearing frame 8 are It is supported by a first thrust bearing 21 arranged. Further, the main shaft 6 is supported by a first main bearing 19, a second main bearing 20, and a second thrust bearing 22 which are arranged in bearing frames 8 and 9 which are connected to each other by an anchor. Also, the Oldham coupling 13
Is disposed between the orbiting scroll 2 and the recessed portion 8a of the bearing frame 8 and is configured to prevent the orbiting scroll 2 from rotating and to perform only revolving motion. In such a state, the fixed scroll 1 is fastened together with the bearing frames 8 and 9 with bolts or the like. Also, motors and rotors
10 is the main shaft 6, and motor / stator 11 is the bearing frame 9
Are fixed by press fitting, shrink fitting or screwing. Further, the oil cap 7 is fixed to the main shaft 6 by press fitting, shrink fitting, or the like. The mechanism thus assembled is housed and fixed in the shell 12 by press fitting, shrink fitting, etc. with the fixed and oscillating scrolls 1 and 2 on the upper side and the motor rotor and the stators 10 and 11 on the lower side.

Next, the operation of the scroll compressor configured as described above will be described.

When the motor / rotor 10 rotates, the orbiting scroll 2 starts to revolve through the main shaft 6 and the Oldham's joint 13, and compression starts according to the operating principle described in FIG. At this time, the refrigerant gas is sucked into the shell 12 through the suction pipe 16 and, as shown by the solid arrow, the bearing frame 9 and the motor / stator 11
Between the shell 12 and the bearing frames 8 and 9 after cooling the motor by passing through a communication hole 27 between the motor rotor 10 and the motor stator 11 and the like.
Through the suction port 3 provided in the fixed scroll 1 into the compression chamber 5 and compressed. The compressed gas is discharged to the outside of the compression chamber 5 from the discharge pipe 17 through the discharge port 4. In addition, the lubricating oil flows from the oil sump 15 as shown by the broken line arrow in the main shaft 6
The oil supplied to the bearings 18 to 20 through the suction port 7a of the oil cap 7 and the oil supply hole 23 by the centrifugal pump action of the oil cap 7 and the oil supply hole 23 disposed in the oil further reaches the thrust bearing 21, and the oil groove 21a, The annular groove 21b and the waste oil hole 21c flow in this order. The oil used for lubrication is mainly the bearing frame8,
The oil is returned to the oil sump 15 through the oil return holes 25 and 26 provided in 9.

[Problems to be Solved by the Invention] Since the conventional scroll compressor is configured as described above, oil is supplied to each bearing and reaches the recess 8a of the bearing frame 8 from the waste oil hole 21c of the thrust bearing 21. Thrust bearing
Since the gap between the outer peripheral surface of 21 and the inner wall surface of the recessed portion 8a is made small, most of them are designed to pass through the oil return holes 25 and 26 and return to the oil sump 15. However, a cutout portion 21d must be provided in 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 coupling 13, and the outer diameter of the thrust bearing 21 is large, so that there is a dent in processing. Since the gap between the inner wall of the portion 8a cannot be made too small, the compression chamber 5
Bearing frame 8 partitioned by the suction part and thrust bearing 21
The hollow portion 8a of the compression chamber 5 cannot be isolated and is actually
There was not a little oil brought into the suction part of, and the amount of oil going up to the circuit outside the compression chamber 5 was large. Further, the thrust bearing 21 is larger than the size that fulfills the function as a bearing, which causes a problem of high cost.

On the other hand, Japanese Utility Model Laid-Open No. 55-144884 discloses a technique in which the pitch of the shape of the oil groove repeated on the frust bearing surface supporting the orbiting scroll is smaller than the orbiting diameter of the orbiting scroll. Has been done. However, similar to the above-described embodiment, the amount of oil brought into the suction portion of the compression chamber is not small, and the amount of oil that is taken out of the compression chamber is large, which is more problematic than the above-described conventional example.

Therefore, the present invention has been made in order to solve the above problems, and the oil used for lubricating the bearing is hardly carried into the suction portion of the compression chamber, and the scroll compression with little oil rise Aim to get the opportunity.

[Means for Solving the Problems] A scroll compressor according to the present invention includes a fixed scroll and an orbiting scroll which have a spiral side plate and form a compression chamber by combining the side plates with each other, and An Oldham coupling and a main shaft for oscillating the dynamic scroll, a thrust bearing having an oil groove on a bearing surface that supports the back surface of the oscillating scroll, the fixed scroll are fixed, and the Oldham coupling and the scroll bearing are housed. In a scroll compressor provided with a bearing frame that supports the main shaft and an oil supply means that supplies oil stored in the bottom portion of the shell to the thrust bearing surface of the thrust bearing, the oil supply means is provided on the thrust bearing surface of the thrust bearing. The oil groove provided on the thrust bearing surface is opened on the inner peripheral edge side and closed on the outer peripheral edge side, and the outer peripheral portion on the thrust bearing surface. A flat surface is formed over the entire circumference so as to come into contact with the back surface of the orbiting scroll, and an oil return hole that connects the oil groove and the bottom of the shell is formed in the bearing frame.

[Operation] In the present invention, the oil supply groove provided on the thrust bearing surface is formed so as to open on the inner peripheral edge side of the thrust bearing surface and close on the outer peripheral edge side of the thrust bearing surface. Lubricates each bearing by overlapping the back surface of the orbiting scroll over the entire circumference on a flat surface without an oil supply groove and directly connecting an oil return hole that communicates with the oil sump at the bottom of the shell provided on the bearing frame. After that, the amount of oil that reaches the recess of the bearing frame is a small amount that leaks from the bearing gap of the thrust bearing, and most of it is discharged to the oil return hole that communicates with the oil sump at the bottom of the shell, which causes the outside of the compressor. It is possible to reduce the amount of oil that is taken out to.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a scroll compressor.

In FIG. 1, reference numeral 21 denotes a thrust bearing, the outer diameter of which is smaller than the outer diameter of the base plate of the orbiting scroll 2, and the thrust bearing surface is configured to always overlap the base plate surface of the orbiting scroll 2. There is.

FIG. 2 (a) is a plan view of the thrust bearing 21 and FIG. 2 (b) is a sectional view.

A concentric annular groove 21b is formed near the outer periphery of the thrust bearing surface of the thrust bearing 21, and a plurality of waste oil holes 21c are provided at equal intervals in the annular groove 21b. Further, radial oil grooves 21a are formed from the annular groove 21b in the inner peripheral direction. Considering the oil supply to the outer peripheral surface 21e outside the annular groove 21b, it is desirable that the distance from the outer diameter of the orbiting scroll 2 to the annular groove 21b be within the revolution diameter of the orbiting scroll 2. That is, the diameter of the annular groove 21b is d ₁ , the outer diameter of the thrust bearing 21 is d ₂ ,
When the orbital diameter of the orbiting scroll 2 is d ₀ , (d ₂ −d ₁ )
Set the annular groove diameter d _{1 such} that / 2 <d ₀ . Further, the oil groove 21a is not limited to a radial shape, and may be any groove that penetrates 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. 1 and communicates with the balancer chamber 29 formed by the bearing frames 8 and 9. This balancer room
29 has a communication hole 27 communicating with the oil sump 15. In addition,
21f is a thrust bearing surface without the oil groove 21a.

As described above, the scroll compressor according to the present embodiment includes the fixed scroll 1 and the orbiting scroll 2 which have the spiral side plates and which form the compression chamber by combining the side plates, and the orbiting scroll 2. The Oldham coupling 13 and the main shaft 6 for oscillating movement, the thrust bearing 21 having an oil groove 21a on the bearing surface that supports the back surface of the oscillating scroll 2, and the fixed scroll 1 are fixed, and the Oldham coupling 13 and the scroll are fixed. Bearing frame 8 for accommodating the bearing 18 and supporting the main shaft 6,
In the scroll compressor including 9 and oil supply means for supplying the oil stored in the bottom portion of the shell 12 that houses the whole to the thrust bearing surface 21f of the thrust bearing 21, the oil supply means is
An oil groove 21a formed on the thrust bearing surface 21f of the thrust bearing 21 and formed in a straight line in the radial direction that is open on the inner peripheral edge side of the thrust bearing surface 21f and closed on the outer peripheral edge side.
And the outer peripheral portion on the thrust bearing surface 21f is in contact with the back surface of the orbiting scroll 2 over the entire circumference, that is, a flat surface which is in intimate contact with or is in contact with the back surface of the orbiting scroll 2 to such an extent that a part thereof comes into contact in terms of time and space. The oil groove 21a and the oil return hole 25 for communicating the bottom of the shell 12 are formed in the frame 8.

In the scroll compressor configured as described above, the oil sucked up from the oil supply hole 23 provided in the main shaft 6 reaches the thrust bearing 21 as the oil supplied to the bearings 18 and 19 as shown by the broken line arrow, It flows through the system paths of the groove 21a, the annular groove 21b, the waste oil hole 21c, the oil return hole 25, the balancer chamber 29, the oil return hole 26, and the oil sump 15. The amount of oil brought into the suction portion of the compression chamber 5 is the total amount of oil accumulated in the recess 8a of the bearing frame 8, and this amount is the outer peripheral surface of the thrust bearing 21.
It is very small because it is determined by the bearing gap formed between 21e and the back surface of the orbiting scroll base plate 2b. Therefore, the lubricating oil is hardly brought into the suction portion of the compression chamber 5, so that the oil rise outside the compressor can be reduced.

FIGS. 3 (a) and 3 (b) show another embodiment of the thrust bearing 21. By providing a bypass oil groove 21g penetrating outward from the annular groove 21b, one of the oil that lubricates each bearing is provided. By sending the portion to the recessed portion 8a of the bearing frame 8, the required amount of oil can be supplied to the suction portion of the compression chamber. Further, the oil groove 21a and the annular groove 21b are on the thrust bearing surface and open on the circumferential edge side,
The shape is not limited as long as it is closed on the outer peripheral side, for example,
As shown in FIGS. 4 (a) and 4 (b), an oil groove which is open on the inner peripheral edge side of the thrust bearing 21 and is spirally formed outward
21a, and this oil groove may communicate with the waste oil hole 21c.

That is, the oil supply means in each of the above-described embodiments of the present invention is provided on the thrust bearing surface 21f of the thrust bearing 21, and is open on the inner peripheral edge side of the thrust bearing surface 21f and closed on the outer peripheral edge side thereof. And an outer peripheral portion on the thrust bearing surface 21f is a flat surface that comes into contact with the back surface of the orbiting scroll 2 over the entire circumference, and an oil return hole 25 that allows the oil groove 21a and the bottom of the shell 12 to communicate with the bearing frame 8. And are formed.

[Effects of the Invention] As described above, according to the scroll compressor of the present invention, the outer diameter of the thrust bearing is smaller than the outer diameter of the orbiting scroll, and the thrust bearing is in contact with the entire circumference of the thrust bearing. , The thrust bearing oil groove is closed at the outer peripheral edge of the bearing surface, the bearing frame is provided with an oil return hole that communicates the oil groove with the oil reservoir at the bottom of the shell, and there is a waste oil hole provided on the outer peripheral side of the oil supply groove. Since the oil return hole communicating with the oil reservoir on the bottom of the shell provided on the bearing frame is directly connected, almost no oil used for lubricating the bearing is brought into the suction part of the compression chamber, and oil does not rise outside the compressor. A compact structure with reduced reliability.

In particular, by changing the size and number of oil grooves, the amount of oil that flows through the oil grooves from the outer peripheral edge of the thrust bearing after the lubrication of the thrust bearing surface is adjusted, and part of the oil after lubrication is necessary for the compression chamber. In the case where a large amount of oil is sucked in, it is possible to increase the degree of freedom in design, reduce the oil buildup of the oil used to lubricate the bearing, and further improve its reliability.

[Brief description of drawings]

1 is a sectional view of a scroll compressor according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are a plan view and a sectional view of a thrust bearing of a scroll compressor according to an embodiment of the present invention. 3 (a), (b) and FIGS. 4 (a), (b)
Is a plan view and a sectional view of a thrust bearing used in a scroll compressor according to another embodiment of the present invention, FIG. 5 is a principle diagram of the operation of the scroll compressor, FIG. 6 is a sectional view of a conventional scroll compressor, 7 (a) and 7 (b) are a plan view and a sectional view of a conventional thrust bearing. In the figure, 1: fixed scroll, 2: orbiting scroll 5: compression chamber, 6: main shaft 8,9: bearing frame, 8a: hollow 12: shell, 13: Oldham coupling 15: oil sump, 18: bearing 21: Thrust bearing, 21a: oil groove 21b: annular groove, 21c: waste oil hole 25: oil return hole. In the drawings, the same reference numerals and symbols indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norihide Kobayashi 6-5-66 Tehira, Wakayama, Wakayama Sanryo Electric Co., Ltd. Wakayama Works (56) Reference JP-A-58-117381 (JP, A) ) Actual development Sho 55-144884 (JP, U)

Claims (1)

[Claims] 1. A fixed scroll (1) and an orbiting scroll (2) having a spiral side plate and forming a compression chamber (5) by combining the side plates with each other, and the orbiting scroll (2). Thrust bearing (2) that has an Oldham coupling (13) and a main shaft (6) that cause the oscillating motion, and an oil groove (21a) on the bearing surface that supports the back surface of the oscillating scroll (2).
1), the fixed scroll (1) is fixed, the Oldham coupling (13) and the scroll bearing (18) are housed, the bearing frame (8, 9) supporting the main shaft (6), and the shell (1)
In a scroll compressor provided with an oil supply means for supplying the oil stored in the bottom portion of 2) to the thrust bearing surface (21f) of the thrust bearing (21), the oil supply means is a thrust bearing surface (21) of the thrust bearing (21). 21f) provided on the above thrust bearing surface (21f)
Of the oil groove (21
a) and the outer peripheral portion on the thrust bearing surface (21f) are flat surfaces that come into contact with the back surface of the orbiting scroll (2) over the entire circumference, and the bearing frame (8) has an oil groove (21a) and a shell. A scroll compressor having an oil return hole (25) communicating with the bottom of (12).