JPH029973A - Scroll type fluid device - Google Patents

Abstract

PURPOSE:To reduce the thrust force and friction loss of a revolution scroll by forming multiple pressure chambers between the end plates of the revolution scroll and a fixed frame and forming thrust bearing faces of the revolution scroll between the pressure chambers. CONSTITUTION:A fixed scroll 7 and a revolution scroll 8 are constituted so that laps 13 and 14 formed on the front faces of end plates 11 and 12 are engaged with each other and the revolution scroll 8 is revolved without being rotated with respect to the fixed scroll 7. In this case, a high-pressure chamber 42, an intermediate-pressure chamber 43 communicated to it via an orifice passage 41a, and a low-pressure chamber 44 adjacent to it are formed between the end plate 12 of the revolution scroll 8 and a fixed frame 15. The thrust bearing face 156 of the revolution scroll 8 is formed between the intermediate- pressure chamber 43 and the low-pressure chamber 44. A thrust oil film is formed between the thrust bearing face 156 and the end plate 12 of the revolution scroll 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scroll-type fluid device, and particularly to a thrust support structure for a revolving scroll.

(Prior Art) Generally, for example, a scroll-type fluid device is used for a compressor in a refrigerator, and this scroll-type fluid device has a hermetically sealed structure as disclosed in Japanese Patent Laid-Open No. 60-73081. A fixed frame is provided in the casing and divided into an upper chamber and a lower chamber, and a fixed scroll and a revolving scroll are housed in the upper chamber, and a motor is housed in the lower chamber. Both of the above-mentioned scrolls each have wraps erected in an involute curve shape on the front surface of an end plate, so that both end plates are faced to each other, and both wraps are meshed with each other, so that the side surfaces of both wraps are in multi-point contact, and between the contacts. A closed chamber is formed.

Furthermore, the above-mentioned revolving scroll is supported by connecting the crankshaft of a motor passing through the fixed frame to the back of the end plate,
The support center of the revolving scroll is provided eccentrically from the crankshaft center, and the revolution of the crankshaft causes the revolving scroll to revolve without rotating with respect to the stationary crawler, so that the sealed chamber is contracted, for example.

Therefore, the refrigerant gas that has flowed into the lower chamber of the sealed case passes through the through hole in the fixed frame, is introduced from the side of the revolving scroll into the sealed chamber between the two wraps, is compressed by the revolution of the revolving scroll, and is then compressed by the revolution of the revolving scroll. It is discharged from the center to the outside of the case.

In this scroll-type fluid device, the closed chamber between both scrolls compresses refrigerant gas, resulting in high pressure, and a downward thrust force acts on the revolving scroll. Therefore, a back pressure chamber is formed between the back surface of the above-mentioned revolving scroll and the fixed frame, and a part of the high-pressure refrigerant gas in the sealed chamber is guided into the back pressure chamber, which presses the revolving scroll upward to reduce the thrust force. That's what I do. This back pressure chamber was formed by cutting two circumferential grooves on the upper surface of the fixed frame, fitting a chip seal into the circumferential grooves, and pressing the chip seal against the back surface of the end plate of the revolving scroll. .

(Problems to be Solved by the Invention) In the scroll-type fluid device described above, the thrust force of the revolving scroll is received by the pressure in the back pressure chamber and the bearing ring provided outside the back pressure chamber. The chip seal and bearing ring forming the back pressure chamber were provided in direct contact with the end plate of the revolving scroll. In this case, since no function such as fluid lubrication is provided between the tip seal, the bearing ring, and the end plate, a large friction loss occurs, resulting in a problem of poor drive efficiency.

The present invention has been made in view of these points, and by applying pressure oil to the back surface of the end plate of the revolving scroll and providing a hydrostatic thrust bearing, the thrust force of the revolving scroll is reduced and friction loss is reduced. The purpose is to reduce this.

(Means for Solving the Problem) In order to achieve the above object, the means taken by the inventions according to claims (1) and (2) are as shown in FIGS. 1 and 2, respectively. An involute curved wrap (13) is placed on the front surface of the mirror plates (11) and (12).

The fixed scroll (7) and the revolving scroll (8), each consisting of a fixed scroll (14) and a revolving scroll (8), are housed in parallel in the high-pressure dome (2) with their respective wraps (13) and (14) meshing with each other. The present invention is based on a scroll-type fluid device in which the scroll (8) is supported eccentrically from the center of the fixed scroll (7), and the above-mentioned revolving scroll (8) is made to revolve around the fixed scroll (7) without rotating. .

The end plate (12) of the revolving scroll (8) and a fixed frame (15) provided on the back side of the end plate (12).
), a high pressure chamber (42) to which high pressure oil is supplied;
Adjacent to the high pressure chamber (42) and a throttle passage (41a)
An intermediate pressure chamber (43) communicates with the high pressure chamber (42) via
) and a low pressure chamber (44) adjacent to the intermediate pressure chamber (43). Further, a thrust bearing surface (15b) receiving the thrust force of the revolving scroll (8) is formed between the intermediate pressure chamber (43) and the low pressure chamber (44), and a thrust bearing surface (15b) is formed between the intermediate pressure chamber (43) and the low pressure chamber (44). Revolution scroll (8
) A thrust oil film was formed between the mirror If (12) and the back surface (1'4 formation).

The high pressure chamber (42) is formed in an annular shape on the outside of the crankshaft (10) connected to the end plate (12) of the revolving scroll (8), and is compressed by the high pressure fluid in the dome (2). High pressure oil is supplied. Further, the intermediate pressure chamber (43) is formed in an annular shape outside the high pressure chamber (42), while the low pressure chamber (44) is formed in an annular shape outside the intermediate pressure chamber (43), and has a dome ( 2) is configured to introduce the low pressure fluid.

(Function) According to the above (R configuration), in the inventions according to claims (1) and (2), the revolving scroll (8) revolves around the fixed scroll (7) without rotating, and for example, the refrigerant gas is compressed and discharged into the dome (2).

Then, the high compression compressed by the high pressure refrigerant gas pressure in the dome (2) is introduced into the high pressure chamber (42), and the high compression in the high pressure chamber (42) passes through the throttle passage (41a) and is reduced in pressure. It flows into the intermediate pressure chamber (43). The intermediate pressure chamber (4
3) The pressure is determined by the balance between the thrust force of the revolving scroll (8) and the pressure in the high pressure chamber (42).
It does not receive the thrust force of the above-mentioned revolving scroll (8). Furthermore, the compression in the intermediate pressure chamber (43) flows into the low pressure chamber (44) through the gap between the thrust bearing surface (15b) and the back surface of the end plate (12), forming a thrust oil film in the gap, The thickness of the thrust oil film is maintained at a predetermined value by raising and lowering the revolving scroll (8) so that the pressure in the intermediate pressure chamber (43) remains constant. This supports the revolving scroll (8) in the thrust direction.

(Effect of the invention) Therefore, according to the scroll type fluid device according to claims (1) and (2), compression of a predetermined pressure is supplied to the intermediate pressure chamber (43) to increase the thrust force of the revolving scroll (8). Since the bearing is stopped and a thrust oil film is formed on the thrust bearing surface (15b) by the oil flowing out from the intermediate pressure chamber (43), the thrust force acting on the revolving scroll (8) is reliably reduced. Therefore, the revolving scroll (8) can be reliably supported in the thrust direction. Furthermore, the revolving scroll (8) is moved up and down by the hydraulic pressure in the intermediate pressure chamber (43), and the thickness of the thrust oil film is maintained at a sufficient predetermined value, so that friction loss can be significantly reduced and drive efficiency can be improved. You can improve your performance.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 3, (1) is a scroll-type fluid device, which is used in a compressor in a refrigerator to compress refrigerant gas to high pressure and discharge it.

The scroll-type fluid device (1) is constructed by housing a scroll mechanism (3) and a drive mechanism (4) in a sealed dome (2), and a suction pipe (5) is installed on the side of the dome (2). and a discharge pipe (6) are connected. 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 fixed scroll (7) and the revolving scroll (8) have a wrap (13) on the front surface of the end plate (11), (12).
(14) are erected in an involute curve shape, and both scrolls (7) and (8) have an end plate (11),
(12) are arranged vertically in parallel with their front surfaces facing each other, and both wraps (13) and (14) are engaged with each other. The fixed scroll (7) has a flange (11a) connected to the outer peripheral edge of the end plate (11), and is fixed to the dome (2) by the flange (11a). Furthermore, a scroll shaft (12a) is provided protruding from the center of the back surface of the end plate (12) of the revolving scroll (8), while a revolving scroll (8) and a crank shaft (10) are mounted on the dome (2). A supporting fixed frame (15) is attached below the revolving scroll (8), and the crankshaft (10) is fitted vertically into the fixed frame (15), so that the crankshaft (10)
is supported. The crankshaft (10) is connected to a boss (10c) having a concave scroll bearing hole (10b) at the upper end of a crank main shaft (10a) passing through the fixed frame (15), and an oil supply passage (10d). is bored, and a balancer (1) is provided on the side of the boss (10c).
0e) is configured to protrude. And, while the electric motor (9) is attached to the crank main shaft (10a),
The scroll bearing hole (10b) is located at its bearing center (01
) is provided eccentrically from the axis (02) of the crank main shaft (10a), and the scroll shaft (12a) of the revolving scroll (8) is fitted into the scroll bearing hole (10b). Furthermore, although not shown, the revolving scroll (8) is provided with an autorotation prevention means, and the revolving scroll (8) prevents the autorotation movement while the scroll bearing hole (
10b) revolves around the fixed scroll (7), and the center (01) of this scroll bearing hole (10b)
(center of scroll axis (12a)) is the center of the revolving scroll (8
), the axial center (02) of the crank shaft (10a)
is the center of revolution.

The fixed scroll (7) and the revolving scroll (8) are in multi-point contact with both wraps (1B) and (14) on the sides (18)
Each wrap (1B), (1
4) is in contact with the other end plate (12), (11), and a sealed chamber (19) is formed between the contact (18).

Further, the flange (1) of the fixed scroll (7) is
1a), there is a suction passage (20) on the inner periphery, and an end plate (11).
A discharge port (21) is formed in the center of each of the suction passages (20), and the suction pipe (5) is connected to the flange (11a).
), and the low pressure refrigerant gas is supplied to the sealed chamber (19) through the suction passage (20).

The fixed frame (15) also has a crankshaft (10
), a flange (152) is continuously formed on the outer circumference of the upper end of a substantially cylindrical support tube (151), which is fixed to the dome (2) on the outer circumference of the flange (152), and is the flange (11a) of the fixed scroll (7)
Closely placed on the underside. And the above fixed scroll (
7) and both flanges (11a) of the fixed frame (15)
.

(152) is provided with a refrigerant gas flow path (Ilb) (15a) penetrating vertically, and the high-pressure refrigerant gas discharged from the discharge port (21) of the fixed scroll (7) is Flow path (llb).

(15a), the dome (2) is filled with the dome (2), which becomes a high-pressure dome, and the discharge pipe (
6) so as to be discharged outside the dome (2).

Moreover, the crank main shaft (10a) and boss (10c) of the crankshaft (10) are fitted and supported in the shaft hole (15b) through the bearing metals (31) and (32) in the support tube (151). At the same time, a balancer chamber (15C) in which the balancer (10e) is housed is formed, and a step portion (15d) is formed above the balancer chamber (15c) on the inner circumference of the flange (152), A support member (153) that supports the revolving scroll (8) in the thrust direction is provided in the stepped portion (15d), and the revolving scroll (8)
) is housed in the mirror plate (12).

Furthermore, a sump (33) is formed at the bottom of the dome (2), and a lubricating oil in the sump (33) is supplied to a differential connected to the lower end of the crankshaft (10). Pressure pump (
34) is immersed.

The differential pressure pump (34) supplies high-pressure lubricating oil to the bearing metal (31) through the oil supply path (10d).
(32) and the scroll bearing hole (10b).

Next, the thrust bearing structure of the revolving scroll (8), which is a feature of the present invention, will be explained.

As shown in FIGS. 1 and 2, the support member (15B) of the fixed frame (15) is formed in a donut shape, and the inner peripheral surface is connected to the boss (15B) of the crankshaft (10).
c), and the outer peripheral surface is fitted into the inner surface of the flange (152), and the balancer chamber (1
5C) is closed, and the balancer chamber (15c)
is communicated with the high-pressure dome (2) via the communication path (15e) and maintained at a high pressure state.

On the upper surface of the support member (153), annular protrusions (154) and (155) are formed on the inner and outer circumferential sides, and the inner protrusion (154) has a small width and a slight height. While the outer protrusion (155) is formed to be low, the outer protrusion (155) is formed to be wide and slightly high.
The upper surface thereof is formed on a sintered metal annular thrust bearing surface (156) which is in contact with the back surface of the end plate (12) of the revolving scroll (8). Further, a seal ring (4
1) is fitted, and the upper surface of the seal ring (41) is in contact with the back surface of the end plate (12) of the revolving scroll (8), dividing the seal ring (41) into an inner circumferential side and an outer circumferential side. The inner peripheral side of the seal ring (41) is connected to the upper surface of the boss (10c) of the crankshaft (10) and the revolving scroll (8).
An annular high-pressure chamber (42) divided by a mirror plate (12) and a back surface of
), and is configured such that high-pressure lubricating oil supplied to the scroll bearing hole (10b) flows into the high-pressure chamber (42). Further, in the upper part of the seal ring (41), there is a concave throttle passage (41a) at a substantially symmetrical position.
41a) are formed across the inner circumferential side and the outer circumferential side, and the two convex portions (154).

(155) is formed in an intermediate pressure chamber (43) adjacent to the outside of the high pressure chamber (42), and the intermediate pressure chamber (43) is depressurized from the high pressure chamber (42) through the throttle passage (41a). The structure is such that reduced-pressure lubricating oil flows into the tank. Further, on the outside of the outer convex portion (155), there are an end plate (12) of the revolving scroll (8) and a flange (15) of the fixed frame (15).
2) and the low pressure chamber (44) is an intermediate pressure chamber (43).
The low pressure chamber (44) is connected to the suction passage (20) formed in the fixed scroll (7) to introduce low pressure refrigerant gas and is maintained at a low pressure state. A thrust oil film is formed between the thrust bearing surface (156) and the back surface of the end plate (12) of the revolving scroll (8) by the lubricating oil flowing from the intermediate pressure chamber (43) to the low pressure chamber (44). It is made up like this.

Here, the basic principle of the thrust bearing structure of the above-mentioned revolving scroll (8) will be explained.

As shown in FIG. 4, the high pressure lubricating oil in the high pressure chamber (42) flows into the intermediate pressure chamber (43) through the throttle passage (41a).
A thrust oil film is formed between the thrust bearing surface (156) and the back surface of the end plate (12) and flows out into the low pressure chamber (44). The pressure (Pa) of the high pressure lubricating oil in the high pressure chamber (42)
is the high-pressure discharge refrigerant gas pressure in the dome (2), and is the pressure in the low-pressure chamber (
The pressure (pb) of the high pressure chamber (44) is determined by the low pressure suction refrigerant gas pressure, while the lubricating oil pressure (Pc) of the intermediate pressure chamber (43) is determined by the downward thrust force of the revolving scroll (8). ) and the pressure (Pa) of the intermediate pressure chamber (43),
(Pc), and the intermediate pressure chamber (43
) The revolving scroll (8) is supported in the thrust direction by the pressure (Pc).

Therefore, the cross-sectional area of the side throttle passage (41a) is (Sac
), and the circumferential length (L) of the thrust bearing surface (156) is m
The communication cross-sectional area between the intermediate pressure chamber (43) and the low pressure chamber (44) determined by m and the thickness of the thrust oil film (h) m+n is expressed as (Sbc
), the flow rate (Qac) of the lubricating oil flowing out from the high pressure chamber (42) to the intermediate pressure chamber (43) is
From the pressure (Pa) and (Pc) in (43), it is expressed by the following equation.

On the other hand, the flow ff1 (Qbc) of lubricating oil flowing out from the intermediate pressure chamber (43) to the low pressure chamber (44) changes depending on the thrust oil film thickness (h), and 43), 44) pressure (Pc),
(Pb) is expressed by the following formula.

Qbccch3 ・L・ (PC-Pb) -■ If this famous flow fA (Qa c), (Qbc) is calculated based on a predetermined compressor, for example, as shown in Fig. 5, the flow is transferred to the intermediate pressure chamber (43) The inflow flow ff1 (QaC) is constant regardless of the thrust oil film thickness (h), while the outflow flow ff1 (Qac) to the low pressure chamber (44) changes as a function of the thrust oil film thickness (h). do. And the two streams m
(Qac) and (Qbc) are balanced at their intersection (A), and the thrust oil film thickness (h) is, for example, 20
It becomes μm.

In addition, the above-mentioned revolving scroll (8) and support member (15B)
The friction loss between the thrust oil film and the friction loss is the resistance when shearing the fluid (lubricating oil) in the thrust oil film, and the shearing force per unit area (τ) is expressed by the following equation.

τ−−μ・ (du/dz) １１μ・ (U/h) ...■μ: Viscosity U Flow velocity in the nislast oil film z Distance in the direction of the nislast oil film thickness U: Sliding speed h nislast oil film thickness It is clear from equation 0 that increasing the thrust oil film thickness (h) reduces the friction loss, so by forming the three pressure chambers (42), (43) and (44) as described above, the thrust oil film thickness (h) can be increased. We try to ensure a large amount of h).

Next, the operation of the scroll type fluid device (1) will be explained.

First, low-pressure refrigerant gas is introduced from the suction pipe (5) into the suction passage (20) in the fixed scroll (7), and then passes through each lap (
13) and (14) into a sealed chamber (19).

The revolving scroll (8) rotates eccentrically due to the rotation of the crankshaft (10), and revolves around the fixed scroll (7) without rotating, so that the sealed chamber (one) has both wraps (13), (14) and are sequentially formed and contracted.

The refrigerant gas is compressed by the contraction of the sealed chamber (19), becomes high-pressure refrigerant gas, and is discharged into the dome (2) from the discharge port (21) of the fixed scroll (7). after that,
The high-pressure refrigerant gas passes through the fixed scroll (7) and the flow passages (11b) and (15a) of the fixed frame (15), extends to the lower part of the dome (2), and exits the dome (2) via the discharge pipe (6). will be derived.

During this compression operation, the high-pressure refrigerant gas flows into the oil sump (33
), the lubricating oil becomes high-pressure oil,
The differential pressure pump (34) passes through the oil supply path (10d) to the bearing metals (31), (32) and the scroll bearing hole (
10b). This high-pressure lubricating oil is then applied to the scroll bearing hole (10b) and the scroll shaft (10b).
2a) into a high pressure chamber (42), and the high pressure chamber (42) is maintained at a high pressure (pa), for example, 20 kg/cm2 determined by the high pressure discharge refrigerant gas pressure.

Next, the high pressure lubricating oil in the high pressure chamber (42) flows through the throttle passage (
41a) and flows into the intermediate pressure chamber (43) under reduced pressure, while the low pressure chamber (44) is connected to the suction path (20), so low pressure refrigerant gas is introduced and the low pressure (pb) is increased. For example, it is maintained at 6 kg/cm2. A downward thrust force is applied to the revolving scroll (8) due to the refrigerant gas pressure in the sealed chamber (one).
In response to this thrust force, the high pressure chamber (42) and intermediate pressure chamber (4
3), the pressure (Pa) and (Pc) are balanced, and the pressure (Pc) of the intermediate pressure chamber (43) is, for example, 8 kg/
cm2, and the pressure (Pc) prevents the thrust force from being received and supports the revolving scroll (8) in the thrust direction.

Furthermore, the lubricating oil in the intermediate pressure chamber (43) flows into the low pressure chamber (44) through the gap between the thrust bearing surface (156) and the back surface of the end plate (12) of the revolving scroll (8), forming a thrust oil film in the gap. is forming. If the thickness (h) of the thrust oil film is small, the pressure (Pc
) rises to push up the revolving scroll (8) and increase the thrust oil film thickness (h). On the other hand, when the thrust oil film thickness (h) is large, the pressure (
Pc) decreases and the revolving scroll (8) sinks, reducing the thrust oil film thickness (h), automatically adjusting the pressure (Pc) in the intermediate pressure chamber (43), and increasing the thrust oil film thickness (h) to a predetermined value. ) will always be ensured.

Therefore, by supplying pressure oil at a predetermined pressure to the intermediate pressure chamber (43) to stop receiving the thrust force of the revolving scroll (8),
Since a thrust oil film is formed on the thrust bearing surface (156) by the outflow surface from the intermediate pressure chamber (43), the thrust force acting on the revolving scroll (8) can be reliably reduced. The orbiting scroll (
8) can be reliably supported in the thrust direction. Furthermore, the revolving scroll (8) is moved up and down by the hydraulic pressure in the intermediate pressure chamber (43), and the thrust oil film thickness is ensured at a sufficient predetermined value, so friction loss can be significantly reduced and drive efficiency improved. You can improve your performance.

In this embodiment, the scroll type fluid device (1) is used as a compressor, but it may also be applied to an expander.

In addition, the high pressure chamber (42) is placed on the outer peripheral side of the intermediate pressure chamber (43),
The low pressure chamber (44) may be provided on the inner peripheral side of the intermediate pressure chamber (43).

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is an enlarged cross-sectional view showing the bearing part of the revolving scroll, FIG. FIG. FIG. 4 is a principle diagram showing the thickness of the thrust oil film, and FIG. 5 is a characteristic diagram showing changes in oil amount with respect to the thickness of the thrust oil film. (1)...Scroll type fluid device, (2)...Dome, (3)...Scroll mechanism, (4)...Drive mechanism, (7)...Fixed scroll, (8)... ...Revolving scroll, (10)...Crankshaft, (11),
(12)... end plate, (13), (14)... wrap, (15)... fixed frame, (41)... seal ring, (41a)... throttle passage, (42)...・・・
- High pressure chamber, (43)...Intermediate pressure chamber, (44)...Low pressure chamber, (153)...Support member, (156)...Thrust bearing surface. Figure 5

Claims (2)

[Claims] (1) A fixed scroll (7) consisting of involute curved wraps (13) and (14) erected in front of end plates (11) and (12), respectively, and a revolving scroll (8) are connected to each wrap (13). ) and (14) to form a high pressure dome (2
), and the revolving scroll (8)
is supported eccentrically from the center of the fixed scroll (7),
In the scroll-type fluid device in which the revolving scroll (8) revolves around the fixed scroll (7) without rotating, the end plate (12) of the revolving scroll (8) and the end plate (1
A high pressure chamber (42) to which high pressure oil is supplied and a high pressure chamber (42) which is adjacent to the high pressure chamber (42) and is connected to the fixed frame (15) provided on the back side of the frame (2) through a throttle passage (41a). An intermediate pressure chamber (43) communicating with the high pressure chamber (42) and a low pressure chamber (44) adjacent to the intermediate pressure chamber (43) are formed, while the intermediate pressure chamber (43) and the low pressure chamber (44) and the thrust bearing surface (156) of the revolving scroll (8).
) is formed, and a thrust oil film is formed between the thrust bearing surface (156) and the back surface of the end plate (12) of the revolving scroll (8). (2) The high pressure chamber (42) is formed in an annular shape on the outside of the crankshaft (10) connected to the end plate (12) of the revolving scroll (8), and is compressed by the high pressure fluid in the dome (2). While high pressure oil is supplied, the intermediate pressure chamber (43)
is formed in an annular shape outside the high pressure chamber (42), and further includes:
2. The scroll-type fluid device according to claim 1, wherein the low pressure chamber (44) is formed in an annular shape outside the intermediate pressure chamber (43) and into which the low pressure fluid of the dome (2) is introduced.