JPH0378586A - Scroll type fluid device - Google Patents

Abstract

PURPOSE:To enable secure sealing for a closed chamber in a simple structure and to reduce a manufacturing cost by applying fluid pressure in an intermediate pressure zone to a thrust bearing to apply urging force toward a revolution scroll side to the thrust bearing. CONSTITUTION:At the time of a compression operation, intermediate pressure refrigerant gas in the compression chamber 3a of an intermediate pressure zone is led to a pressure introduction passage 18 from an intermediate pressure port 18a and to be blowed to the small gap 18b of a bearing groove 16 from a stationary scroll 7 and a frame 11. Next, the refrigerant gas pushes a thrust bearing 17 to the back of a revolution scroll 8, the scroll 8 is shifted upwards and the top end of a lap 8b is pressed to the front of an end plate 7a of the stationary scroll 7. Namely, the scroll 8 is applied by pressure from only the bearing 17 to be pressed to the scroll 7 side. Hereupon, as the height to a scroll lap 7b is equal to the height of the scroll lap 8b, the top end of the lap 7b is pressed to the front of the end plate 8a to securely seal among compress chambers 3a, 3a... formed by the laps 7b, 8b and the end plates 7a, 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scroll-type fluid device used in a compressor of a refrigeration system, and particularly relates to sealing measures at the end surface of the wrap.

(Prior Art) Generally, some compressors in refrigeration equipment use a scroll-type fluid device, and this scroll-type fluid device has a structure inside a casing, as shown in Japanese Patent Publication No. 57-23793, for example. A fixed scroll and a revolving scroll are housed in the , and each of the fixed scroll and the revolving scroll has a wrap spirally erected on the front surface of an end plate, so that the front surfaces of both end plates face each other,
By meshing both wraps with each other, the side surfaces of both wraps are brought into contact at multiple points, and a compression chamber is formed between the contact portions.

Further, a refrigerant outlet is provided at approximately the center of the end plate of the fixed scroll, while a frame is provided on the back side of the end plate of the revolving scroll, and a frame is provided on the back side of the end plate.
The revolving scroll is supported by a crankshaft to which an electric motor is attached, and the center of the revolving scroll is eccentric from the axis of the crankshaft, and the rotation of the crankshaft causes the revolving scroll to move relative to the fixed scroll. It is configured so that the compressor chamber rotates without rotating on its own axis, and the compression chamber contracts.

Furthermore, a tip seal is attached to the tip end surface of both wraps for the purpose of sealing between adjacent compression chambers. This chip seal is made by inserting a sealing material made of multiple thin metal plates in a stacked manner into a sealing groove formed on the tip end surface of the wrap, and bringing the end surface of the sealing material into contact with the front surface of a roughened mirror plate. This is intended to prevent fluid leakage between the plurality of compression chambers formed by the wrap, that is, fluid leakage from the high pressure chamber side to the low pressure chamber side.

(Problem to be Solved by the Invention) However, in a scroll-type fluid device having a tip seal as described above, during operation, the compression chamber, especially near the outlet, is in a high pressure state, so the revolving scroll A downward pushing force, that is, a thrust force that attempts to separate the revolving scroll from the fixed scroll, is acting, and the high pressure above causes the tip seal to come into contact with the roughened head plate, so that the tip seal is pressed against the bottom surface of the seal groove. Around this tip seal, the gap between the wrap tip and the roughened end plate and the gap between the back surface of the tip seal and the bottom of the seal groove become large, so high pressure is generated in the circumferential direction of the scroll along these gaps. The pressure on the chamber side will leak.

Therefore, there has been a problem in that the compressor efficiency decreases due to this fluid leakage.

Therefore, as an example of a scroll-type fluid device that attempts to ensure sealing performance at the tip of the wrap without using a tip seal, there is a fluid device as disclosed in Japanese Patent Application Laid-open No. 80088/1988.

The device disclosed in this publication is configured such that the fixed scroll is movable in the direction toward the revolving scroll, and the intermediate pressure in the compression chamber is applied to the back side of the fixed scroll. is pressed toward the revolving scroll side. That is, by pressing the wrap end surface of each scroll against the front surface of each end plate facing each other, the sealing performance between each compression chamber is improved and a tip seal is not required. However, in such a configuration, a new support means must be adopted to make the fixed scroll movable, and as the number of parts increases, the structure becomes more complicated, leading to an increase in the number of failure points. It lacked practicality due to the problems it caused.

SUMMARY OF THE INVENTION An object of the present invention is to provide a scroll-type fluid device that has a simple configuration and does not require a tip seal.

(Means for Solving the Problems) In order to achieve the above object, the present invention applies fluid pressure in a sealed chamber to the back side of the revolving scroll to press the revolving scroll toward the fixed scroll side, and wraps the scroll by pressing the revolving scroll toward the fixed scroll side. The sealing performance of the tip portion is improved, and the specific means thereof will be described below.

First, in the invention described in claim (1), as shown in FIGS. 1 and 2, a fixed scroll (7) and a revolving scroll (8) are housed in a casing (2). Both scrolls (7) and (8) each have an end plate (7a).
, (8a) is configured with spiral wraps (7b) and (8b) erected, and both of the wraps (7b),
(8b) are intermeshed with each other, both wraps (7b),
(8b) and both end plates (7a) and (8a) form a fluid sealed chamber (3a), and the above-mentioned revolving scroll (8) revolves around the fixed scroll (7) without rotating. The object is a scroll-type fluid device configured such that the volume of the sealed chamber (3a) changes. The revolving scroll (8) is placed on a frame (11) fixed to the inner wall of the casing (2), and a recess (16) is formed on the surface of the frame (11) facing the revolving scroll (8). ing. Furthermore, the recess (1
6) The thrust bearing (17) of the revolving scroll (8)
is inserted into the recess (1) so as to be slidable in the depth direction.
The revolving scroll (8) is pressed toward the fixed scroll (7) via the thrust bearing (17) by introducing pressure fluid to the rear side of the thrust bearing (17) in the inner wall of each wrap (7b).

The tip of (8b) is connected to the closed chamber (3a) in the intermediate pressure region so as to be in contact with mirror plates (7a) and (8a) facing each other.

Further, in the invention described in claim ('2J), in the scroll type fluid device according to claim (1), the recessed portion of the frame (11) is formed in the groove (16) for the annular bearing, The thrust bearing (17) has a groove (16) in the above bearing.
), and the bearing is fitted in the groove (16), while the front surface of the end plate (7a) of the fixed scroll (7) has an intermediate groove that communicates with the closed chamber (3a) in the intermediate pressure region. A pressure port (18a) is opened, and the pressure introduction path (18) connects the intermediate pressure port (18a) and the bottom surface of the bearing groove (16).
is formed on the fixed scroll (7) and the frame (11).

(effect) The effects of the above configuration will be described below.

First, in the invention described in claim (1), when a motor or the like is driven, the revolving scroll (8) rotates relative to the fixed scroll (7) without rotating, for example,
The refrigerant is compressed to a high pressure state and discharged into the refrigerant circuit through the inside of the casing (2). Further, the fluid pressure in the intermediate pressure region of the sealed chamber (3a) flows into the recess (16) and acts on the thrust bearing (17).
By applying a biasing force toward the revolving scroll (8), the revolving scroll (8) is pressed against the fixed scroll (7), and each end plate (7a) whose tips face each other ), (8a) Press it to the front. As a result, without using a conventional tip seal, it is possible to easily attach the tips of the wraps (7b) and (8b) of the scrolls (7) and (8) to the mirror plate (which the tips face) with a simple structure.
8a), (7a) A sealing structure with the front surface is obtained.

On the other hand, in the invention according to claim 2, the fluid in the closed chamber (3a) in the intermediate pressure region flows from the intermediate pressure port (18a) through the pressure introduction path (18) into the bearing groove (16). , each wrap (7) is pushed up by the thrust bearing (17) to push the revolving scroll (8) toward the fixed scroll (7).
b), (8b) Attach the tip to each end plate (8a), (7a
) Press it to the front.

Thereby, the pressing force of the revolving scroll (8) is set by appropriately setting the position of the intermediate pressure port (18a).

(Example) Embodiments of the present invention will be described below with reference to the drawings.

As shown in Figure 1, (1) is a scroll compressor;
Used in refrigerators to compress refrigerant gas to high pressure and discharge it.

The scroll compressor (1) has a hermetic casing (2)
A scroll mechanism (3) and a drive mechanism (4) are housed inside, and a suction pipe (5) is connected to the side surface of the sealed casing (2), and a discharge pipe (6) is connected to the top surface. ing. The scroll mechanism (3) includes a fixed scroll (7) and a revolving scroll (8), and the drive mechanism (4) includes an electric motor (9) and a crankshaft (10).

The above fixed scroll (7) and revolving scroll (8)
Wrap (7b), (
8b) are arranged in a spiral shape, and both scrolls (7)
, (8) is the end plate (7a).

(8a) are arranged vertically in parallel with their front surfaces facing each other, and both wraps (7b) and (8b) are engaged with each other, and the side surfaces of both wraps (7b) and (8b) are in multi-point contact, and the contact A compression chamber (3a) is formed between the sections, while a refrigerant outlet (7c) is formed in the center of the end plate (7a) of the fixed scroll (7).
) are provided on both the top and bottom sides. The fixed scroll (7) also has a flange (
7d) are arranged in series, and are fixed to the inner circumferential surface of the sealed casing (2) by the flanges (7d), and the sealed casing (
The internal space of 2) is divided into an upper high pressure chamber (2a) and a lower low pressure chamber (2b), and the discharge pipe (6) is communicated with the high pressure chamber (2a). That is, this scroll type compressor is of a low pressure tom type. Further, on the back surface of the end plate (8a) of the revolving scroll (8), a scroll shaft (8c) is provided concentrically with the center of the revolving scroll (8).
) is provided protrudingly. Also, the above-mentioned wrap (7b).

(8b) and the flange (7) of the fixed scroll (7).
d), a suction chamber (14) is formed between the two.

On the other hand, a frame (11) is fixedly installed in the center of the sealed casing (2), located on the back side of the revolving scroll (8), and the crankshaft (10) is supported by a radial bearing (12), ( 12) to the frame (11
), while the suction pipe (5) is communicated with the lower part of the frame (11), and the frame (11)
The low-pressure refrigerant gas is configured to flow into the suction chamber (14) through a suction passage (11a) formed in the suction chamber (14).

The crankshaft (10) is a crank main shaft (10
an electric motor (9) is attached to the main shaft (10a), and a connecting portion (10b) is provided at the upper end of the crankshaft (10a), and the connecting portion (10b) has a fitting hole (10c) for the scroll shaft (8c). is formed eccentrically from the axis (02) of the crankshaft (10), and by fitting the scroll shaft (8c) into the fitting hole (10c), the scroll shaft (8c) The center (01) is the crank shaft (10
It is arranged eccentrically by a predetermined dimension from the axis (02) of a). Furthermore, the orbiting scroll (8) and the frame (11
Although not shown, a rotation prevention mechanism for the revolving scroll (8) is provided between the crankshaft (10) and the above-mentioned crankshaft (10).
Due to the rotation of the revolving scroll (8), the fixed scroll (
7), the compression chamber (3a) moves spirally toward the center, contracts in volume, and compresses the refrigerant gas.

Furthermore, a storage part (2C) for lubricating oil (L) is formed at the bottom of the sealed casing (2), while a connecting part (2C) is formed in the crankshaft (10a) from its lower end (10d). An oil supply path (10e) extending over the bottom of the scroll shaft insertion hole (10c) of 10b) is bored, and the lower end (10d) is immersed in the 71-force oil (L) of the storage part (2c), The lubricating oil (L) is supplied to the radial bearing (12) and the scroll shaft (
8C) We try to supply it to the surrounding area.

Further, the frame (11) has its outer periphery fixed to and supported by the inner circumferential surface of the casing (2), and the upper surface of the outer periphery is tightly fitted to the lower surface of the flange (7d) of the fixed scroll (7). ing. On the other hand, the upper center of the frame (11) is removed in a concave shape, and a balancer chamber (1l b
) is formed in the balancer chamber (11b), and a balance weight (15
) is installed to maintain rotational balance during operation.

The feature of the present invention lies in the structure of the thrust bearing of the above-mentioned revolving scroll (8). The structure of this thrust bearing is that the annular bearing has a groove (16) which is a recess on the upper surface of the frame (11) on the outer peripheral side of the balancer chamber (11b).
A thrust bearing (17) is formed in an annular shape having approximately the same shape as the groove (16).
) is fitted. Specifically, as shown in Fig. 2, the depth of the groove (16) of the bearing is set slightly smaller than the height dimension of the thrust bearing (17), and the bearing has a groove (16) with a depth slightly smaller than the height of the thrust bearing (17). O-rings (16a
), (16a) are buried so that the bearing seals the small gap (18b) between the side surfaces of the groove (16) and the thrust bearing (17). Furthermore, the thrust bearing (17) is molded to such a height that its upper surface always protrudes from the upper surface of the frame (11), and the bearing moves in the groove (16) in the vertical direction while its side surface contacts the O-ring (16a). The revolving scroll (8) is supported on the frame (11) via the thrust bearing (17). The greatest feature of the present invention is that this bearing has a groove (16) and the compression chamber (3a).
and multiple (two in Figure 1) pressure introduction passages (18
) is a pressure introduction mechanism communicated by. This pressure introduction passage (18) opens at the front surface of the end plate of the fixed scroll so that one end communicates with the compression chamber (3a) in the intermediate pressure region, forming an intermediate pressure bow (18a), and the intermediate pressure port After extending the end plate (7a) of the fixed scroll (7) in the outer circumferential direction from (18a), bend it downward at the flange (7d), and then move the inside of the frame (11) below the revolving scroll (8) in the centripetal direction. The other end of the bearing has a groove (16).
It is formed with an opening on the bottom surface. The above-mentioned intermediate pressure region is a compression chamber (in which refrigerant exists at a pressure state approximately intermediate between the refrigerant pressure (low pressure) near the suction chamber (14) and the refrigerant pressure (high pressure) near the refrigerant outlet (7C). 3a). Therefore, during compressor operation, the bearing is configured to guide the intermediate pressure of the refrigerant in the compression chamber (3a) into the groove (16).

Next, the operation of this device with the above configuration will be explained.

First, when the scroll compressor (1) is driven, the crankshaft (10) rotates as the electric motor (9) is driven, and this rotation causes the revolving scroll (8) to move relative to the fixed scroll (7). It revolves without rotating. Then, from the suction pipe (5) to the low pressure chamber (
The refrigerant sucked into 2b) flows through the suction passage (lla) and the suction chamber (14) into the compression chamber (3a) formed between the scrolls (7) and (8). This compression chamber (
3a) is formed from the outside of the wraps (7b) and (8b), and its volume contracts while moving spirally toward the central refrigerant outlet (7C), and the refrigerant gas flows into the compression chamber (3a).
After being sequentially compressed within the refrigerant and flowing out from the refrigerant outlet (7C) of the fixed scroll (7) to the high pressure chamber (2a) of the casing (2), it is discharged from the discharge pipe (6) into the refrigerant circuit.

During the above-mentioned compression operation, the bearing of the revolving scroll (8) by the thrust bearing (17) will explain the state in which the refrigerant gas at the intermediate pressure in the compression chamber (3a) in the intermediate pressure region is transferred to the intermediate pressure port. (18a) is led to the pressure introduction path (18), passes through the fixed scroll (7) and the frame (11), and the bearing flows into the small gap (18b) formed in the groove (16), and the thrust bearing ( 17
) and presses the thrust bearing (17) against the back surface of the revolving scroll (8). As a result, the revolving scroll (8) is moved upward and its wrap (8b
) The tip end surface is pressed against the front surface of the end plate (7a) of the fixed scroll (7).

That is, the revolving scroll (8) is a thrust bearing (17)
This means that it is pressed against the fixed scroll (7) by pressure from only the scroll. At this time, the above fixed scroll (
Since the height of the wrap (7b) of 7) is the same as the height of the wrap (8b) of the revolving scroll (8), the tip of the wrap (7b) of the fixed scroll (7) is also the same as that of the revolving scroll (8).
The compression chambers (3a), (3a), which are pressed against the front surface of the end plate (8a), are formed by the wraps (7b), (8b) and the end plates (7a), (8a).
・Reliably seal the gap. In this seal, the end plate (7a) of each wrap (7b), (8b).

Since the pressing force on (8a) uses the intermediate pressure in the compression chamber (3a), the tip end surface of each wrap is not pressed more than necessary against each end plate, which suppresses the occurrence of wear on the wraps. Further, even when the differential pressure between high and low levels fluctuates due to changes in the operating conditions of the compressor (1), sealing can be performed using the intermediate pressure that follows the fluctuations, thereby preventing refrigerant leakage. Furthermore, a desired pressure state can be obtained by appropriately setting the position of the intermediate pressure port (18a).

In this way, wrap (7b), (8b) tip and tf
Since the seal structure is formed by the front surfaces of the plates (7a) and (8a), there is no need for the chip seal that was conventionally provided at the end of the wrap, and high pressure is applied in the circumferential direction of the scroll as in the past. Leakage is prevented and compressor efficiency is improved.

Note that the present invention is not limited to the embodiments described above, and can be applied to expanders, vacuum pumps, and the like.

(Effects of the Invention) As described above, according to the present invention, the following effects are achieved.

First, in the invention set forth in claim (1), the fluid pressure in the intermediate pressure region acts on the thrust bearing, and by applying a biasing force to the thrust bearing toward the revolving scroll,
The front end of each wrap is pressed against the front surface of the end plate facing oppositely to each other to seal between the sealed chambers. As a result, a sealing structure between the tip end surface of each lap and the front surface of the end plate can be obtained without using a conventional tip seal, and a sealed chamber can be reliably sealed with a simple configuration, and manufacturing costs can also be reduced. I can figure it out.

In addition, the thrust bearing does not require high machining accuracy, which simplifies machining.

On the other hand, in the invention described in claim (a), the fluid in the sealed chamber in the intermediate pressure region flows from the intermediate pressure port through the pressure introduction path into the bearing groove, and the thrust bearing pushes the revolving scroll toward the fixed scroll side. The tip of the wrap of the revolving scroll is pressed against the front surface of the end plate of the fixed scroll.Thereby, by appropriately setting the position of the intermediate pressure port, the pressing force at the tip of the wrap of the revolving scroll can be set within a predetermined range.

[Brief explanation of drawings]

FIGS. 1 and 2 show an embodiment of the present invention,
FIG. 1 is a longitudinal sectional view of a scroll compressor, and FIG. 2 is an enlarged sectional view showing the vicinity of a thrust bearing. (1)...Scroll compressor (2)...Hermetic casing (3a)...Compression chamber (sealed chamber) (7)...Fixed scroll (8)...Revolving scroll (7a), (8a)... End plate (7b), (8b)... Wrap (11)... Frame (16)... Bearing is groove (recess) (17)... Thrust bearing (18)...・Pressure introduction path (18a)...Intermediate pressure port (1)...Scroll compressor (2)...Hermetic casing (3a)...Compression chamber (7)...Fixed scroll (8) ...Revolving scroll (7a), (8a)...Kagami Saka (7b), (8b)...Wrap (11)...Frame (16)...Bearing is in groove (17)... Thrust bearing (18)...Pressure introduction path (18a)...Intermediate pressure port

Claims (2)

[Claims] (1) A fixed scroll (7) and a revolving scroll (8) are housed in a casing (2), and both scrolls (7) are housed in a casing (2).
) and (8) are configured by spiral wraps (7b) and (8b) standing on end plates (7a) and (8a), respectively, and both wraps (7b) and (8b) are mutually connected. are engaged with both wraps (7b), (8b) and both end plates (7a).
, (8a) form a fluid sealed chamber (3a), and the revolving scroll (8) is connected to the fixed scroll (7).
In the scroll-type fluid device configured such that the volume of the sealed chamber (3a) changes by revolving without rotating relative to ), the revolving scroll (8) is fixed to the inner wall of the casing (2). The orbital scroll (8) of the frame (11) is placed on the frame (11)
A recess (16) is formed in the opposing surface, and the thrust bearing (17) of the revolving scroll (8) is fitted into the recess (16) so as to be slidable in the depth direction. On the back side of the thrust bearing (17), the revolving scroll (8) is rotated by the introduction of pressure fluid into the thrust bearing (17).
An end plate (7) is pressed toward the fixed scroll (7) through
a), a closed chamber (3) in the intermediate pressure region so as to be in contact with (8a)
A scroll-type fluid device, characterized in that it is in communication with a). (2) In the scroll-type fluid device according to claim (1), the recess of the frame (11) has an annular bearing groove (1).
The thrust bearing (17) is formed in the same shape as the bearing groove (16), and the thrust bearing (17) is formed in the same shape as the bearing groove (16).
6), while the fixed scroll (7) end plate (
7a) An intermediate pressure port (18a) that communicates with the closed chamber (3a) in the intermediate pressure region is opened on the front surface, and a pressure introduction path that connects the intermediate pressure port (18a) and the bottom surface of the bearing groove (16). (18) is fixed scroll (7) and frame (
11) A scroll-type fluid device characterized by being formed in.