JPH0670434B2 - Scroll fluid device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scroll fluid device, and more particularly to a support structure for an orbiting scroll.

(Prior Art) Generally, a scroll fluid device is used as a compressor in a refrigerator, and its scroll structure has a fixed scroll (a) and an orbiting scroll (a) as shown in FIGS. 10 and 11. b) and is comprised.

Both scrolls (a, b) are made by wrapping (e, f) spirally standing on the front surface of the end plate (c, d).
b) is arranged in parallel with the front faces of the end plates (c, d) facing each other, and is also provided by meshing both laps (e, f). Further, the orbiting scroll (b) is supported by the crankshaft (g) being connected to the rear surface of the end plate (d), and the flank shaft (g) is
The pin center (01) (movable fulcrum) is the center of the crankshaft (0
2) The wraps (e, f) of both scrolls (a, b) are provided eccentrically from the (revolution center) and contact at multiple points on the side (h).
However, a closed chamber (i) is formed between the contacts (h).
And, a suction port (j) is provided on the side of the fixed scroll (a).
However, a discharge port (k) is bored in the central portion so that a fluid such as a refrigerant vapor in a refrigerator flows out.

The operation principle of this scroll fluid device is shown in FIG.
Describing based on (d), the revolution scroll (b)
Is revolved around the shaft center (02) of the crank main shaft with respect to the fixed scroll (a) by the rotation of the crank shaft (g). 8 (a) to 8 (d) show a state in which the revolution scroll (b) is revolved clockwise at 90 degrees, and first, FIG. 8 (a) shows the outer edge of each wrap (e, f). Is in an initial state in which the sealed chamber (i) is formed by contacting the other wrap (e, f), and is sealed in the sealed chamber (i) that has flowed in through the suction port (j). Then, when the revolution scroll (b) is revolved in the clockwise direction, FIG.
As shown in (d), the sealed chamber (i) is sequentially contracted to compress the enclosed fluid, and the enclosed fluid is rotated once to return to FIG. 8 (a). By repeating this operation, the closed chamber (i) communicates with the discharge port (k) in the most contracted state, and the high-pressure fluid flows out.

On the contrary, when the high-pressure fluid is supplied from the discharge port (k), the revolution scroll (b) revolves counterclockwise (see FIGS. 8 (d) to 8 (a)) and power is obtained.

In this scroll fluid device, both scrolls (a,
Since both end plates (c, d) receive a force (separation force) in the direction in which they are separated from each other by the fluid pressure in the closed chamber (i) between b), the end plates (c, d) and the wraps (e, f) are separated. Axial support is also required so as not to separate from the tip surface. The method of supporting the orbiting scroll (b) is as follows.

A device that applies fluid pressure to and supports the end plate (d) of the orbiting scroll (b).

 Supported by thrust bearings.

 What is supported by both bearings with the above fluid pressure.

Of these supporting methods, the present invention is one in which the fluid pressure is used to support, and in the method using this fluid pressure, the pressure center (03) of the back pressure as shown in FIG. There are those in which the center of the pressure (03) coincides with the center of the main shaft (02) of g), and the center of pressure (03) coincides with the center (01) of the pin of the crankshaft (g) as shown in FIG.

That is, as shown in FIG. 10, a ring member (m) and two ring-shaped seal members (n, q) are provided on the frame (l) on the rear side of the orbiting scroll (b), and the seal member (l) is provided. n,
q) contacts the back surface of the end plate (d) to form a donut-shaped back pressure chamber (s), and the back pressure chamber (s) communicates with the closed chamber (i) through the small hole (t). That is, the fluid pressure in the closed chamber (i) is introduced into the back pressure chamber (s) to press the revolution scroll (b) toward the fixed scroll (a). Since the back pressure chamber (s) is fixed to the frame (l), the center of pressure (03) coincides with the center of revolution (02) of the revolution scroll (b).

Further, as shown in FIG. 11, a back pressure chamber (v) is formed between the orbiting scroll (b) and the frame (u) on the back side, and the back pressure chamber (v) is the one shown in FIG. Small hole (w)
The orbiting scroll (b) is pressed by being communicated with the closed chamber (i) via the. Since the back pressure chamber (v) applies back pressure to the entire back surface of the end plate (d), the center of pressure (03) must match the center of pin (01) (movable fulcrum) of the crankshaft (g). become.

(Problem to be Solved by the Invention) In the scroll fluid device described above, the revolution scroll (b) has a radius within the revolution surface due to the fluid enclosed in the closed chamber (i) as shown in FIG. In addition to the directional load (F2) and the tangential load (F3), the centrifugal force (F1) generated by the revolution will act. And, of these, the tangential load (F3) and the centrifugal force (F1) are mainly
It acts on the orbiting scroll (b) as a so-called overturning moment for inclining the orbiting scroll (b) with respect to the fixed scroll (a).

In order to remove this overturning moment, back pressure chamber (s,
The pressure of v) is made excessive and the oil film pressure distribution of the outer sliding part (see Fig. 13 (A)) between the lower surface of the flange between the scrolls (a, b) and the upper surface of the end plate is unbalanced, and this asymmetry Or the pressure of the back pressure chamber ((s, v) is made insufficient, and the oil film pressure distribution that acts on the thrust bearing provided facing the back surface of the end plate (d) of the orbiting scroll (b). Was made asymmetric and was removed by this imbalance.

However, the pressure center (03) of the conventional back pressure chamber (s, v)
Is coincident with the main shaft center (02) of the crankshaft (g) (see FIG. 10) or the pin center (01) of the crankshaft (g) (see FIG. 11), so that as shown in FIG. In the case of a shaft that coincides with the main axis (02) of the crankshaft (g), the moment and spin due to the centrifugal force (F1) that acts on the center of gravity of the orbiting scroll, with the bearing center point (04) of the scroll shaft as the fulcrum. The action direction of the moment due to the pressure (F′4) coincides, and the overturning moment is increased. Also, in the case where it coincides with the pin center (01) of the crankshaft (g),
Since the back pressure (F ″ 4) acts on the bearing center point (04), it does not affect the moment and the overturning moment cannot be reduced.

Therefore, the revolution scroll (b) is the fixed scroll (a)
The end plate (d) is tilted with respect to
However, since the centrifugal force (F1) is increased, this force also becomes large, and there are problems such as severe wear and seizure. Further, there is a problem that a small gap is generated between the tip of the wrap (e, f) and the surface of the end plate (c, d) facing the wrap (e, f), which lowers the volumetric efficiency.

In view of such a point, the present invention positions the pressure center (03) of the back pressure chamber (24) further eccentric to the orbiting center (02) of the orbiting scroll (8) substantially in the eccentric direction. The purpose is to offset or reduce the overturning moment due to the centrifugal force by the moment due to the back pressure.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the structure of the invention according to claim 1 has an end plate (11, 1) as shown in FIG. 1 to FIG.
The fixed scroll (7) and the orbiting scroll (8) each having the wraps (13, 14) set upright on the front of the wrap (1)
3,14) are meshed side by side, and the orbiting scroll (8)
Is supported by a movable fulcrum (01) that is eccentric to the fixed scroll (7), is prevented from rotating with respect to the fixed scroll (7), and is revolvable, and the side surfaces of both wraps (13, 14) are The closed chamber (18) is provided between the wraps (13, 14) so that the back pressure side (24) is provided on the rear side of the end plate (12) of the revolution scroll (8). / 30 / ...) and the orbiting scroll (8) is pressed against the fixed scroll (7) or the load applied to the bearing that axially supports the orbiting scroll (8) is reduced. Presupposes things.

The pressure center (03) of the back pressure chamber (24/30 / ...) Is substantially on the eccentric direction line of the movable fulcrum (01) with respect to the revolution center (02) of the revolution scroll (8). It is characterized by being located more eccentrically.

Further, in the configuration taken by the invention according to claim 2, in the invention according to claim 1, the back pressure chamber (24/30 / ...) At least the end plate (12) of the revolution scroll (8) and the end plate (12). ) And the frame (21) provided on the back side of the frame, the partition part inside the back pressure chamber (24/30 / ...) with respect to the end plate (12) of the revolution scroll (8) is a frame (21).
The circle fixed to the outer partition is an orbiting scroll (8)
It is a circle that revolves around.

In addition, the constitution taken by the invention according to claim 3 is, as shown in Fig. 1, in the invention according to claim 1, the back pressure chamber (24).
Is an orbiting scroll (8) end plate (12) and the end plate (12)
And a frame (21) provided on the back side of the. The partition section inside the back pressure chamber (24) with respect to the end plate (12) of the orbiting scroll (8) is mounted on the frame (21) so as to be in sliding contact with the end plate (12) of the orbiting scroll (8). The end plate (12) of the orbiting scroll (8) is formed by the ring-shaped tip seal (22).
The outer partition of the back pressure chamber (24) is formed by a ring-shaped tip seal (23) mounted on the end plate (12) of the orbiting scroll (8) so as to be in sliding contact with the frame (21). .

In addition, the constitution taken by the invention according to claim 4 is, as shown in FIG. 4, in the invention according to claim 1, the back pressure chamber (30).
Of the orbiting scroll (8) and the end plate (1)
A flange (11a) that is continuous with the outer peripheral edge of the end plate (11) of the fixed scroll (7) and is in sliding contact with the front face of the end plate (12) of the revolving scroll (8) and the frame (21) provided on the back side of the second scroll. ) And are formed by division.
Then, the inner partition of the back pressure chamber (30) with respect to the end plate (12) of the orbiting scroll (8) is mounted on the frame (21) so as to be in sliding contact with the end plate (12) of the orbiting scroll (8). The outer partition of the back pressure chamber (30) with respect to the end plate (12) of the orbiting scroll (8) is formed by the ring-shaped tip seal (22). It is formed by a swinging part (110) between the flange (11a) and the end plate (12) of the orbiting scroll (8).

(Operation) According to the present invention having the above-described configuration, when the revolution scroll (8) is revolved around the movable fulcrum (01), the sealed chamber (18) is formed between the contact between the both wraps (13, 14) and the enclosed fluid is compressed. Or while expanding, the orbiting scroll (8) is pressed toward the fixed scroll (7) by the back pressure of the back pressure chamber (24/30 / ...), and the moment due to the back pressure cancels or reduces the moment due to the centrifugal force. However, the orbiting scroll (8) is supported so as not to tilt with respect to the fixed scroll (7).

Example 1 An example of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, (1) is a scroll fluid device, which is used for a compressor in a refrigerator and compresses refrigerant vapor (fluid) to a high pressure and discharges it.

The scroll fluid device (1) is constructed by housing a scroll mechanism (3) and a drive mechanism (4) in a closed case (2), and a suction pipe (5) on a side of the case (2). )
However, a discharge pipe (6) is connected to the upper part. The skeleton mechanism (3) comprises a fixed scroll (7) and an orbiting scroll (8), and the drive mechanism (4) is an electric motor (9).
And a crankshaft (10).

The fixed scroll (7) and orbiting scroll (8)
Consists of wraps (13,14) standing upright in front of the end plates (11,12), and both scrolls (7,8) are end plates (11,12).
Side-by-side with the front sides of the wraps facing each other (13,1
4) is engaged. The fixed scroll (7) has an end plate (1
A flange (11a) is continuously provided on the outer peripheral edge of 1) and is fixed to the case (2) by the flange (11a). Further, a scroll shaft (12a) is provided at the center of the rear surface of the end plate (12) of the orbiting scroll (8).

On the other hand, the crankshaft (10) has a boss (10c) having a concave scroll bearing (10b) at the upper end of the crank main shaft (10a).
Are connected to each other, are fixed to the case (2), and have a crank frame (10
a) is penetrated so that the crankshaft (10) becomes a crank bearing (1
01) is supported through. This crank spindle (10
A motor (9) is attached to a), and the scroll bearing (10b has a bearing center (01) at the crank spindle (10b).
It is provided eccentrically from the shaft center (02) of (a), and the scroll shaft (12a) of the rotary scroll (8) is fitted in the scroll bearing (10b).

Then, a plurality of spheres (100) are provided between the outer peripheral surfaces of the end plates (11, 12) of both scrolls (7, 8) via guide circular grooves to prevent the orbital scroll (8) from rotating and the scroll bearing. Revolution scroll due to the eccentricity of (10b) (8)
Revolves around the fixed scroll (7), and the center (01) of the scroll bearing (10b) (center of the scroll shaft (12a)) is the movable fulcrum of the revolving scroll (8) and the crank spindle ( The axis (02) of 10a) is the center of revolution.

Both the fixed scroll (7) and the orbiting scroll (8) wraps (13, 14) are provided so as to come into contact (17) at multiple points on the side surface, and the end surface is on the other end plate (12, 11). A closed chamber (18) is formed between the contact (17).
Further, the end plate (11) of the fixed scroll (7) is provided with a suction port (19) in the outer peripheral portion thereof and a discharge port (20) in the central portion thereof, and the discharge pipe (6) is provided in the discharge port (20). Is connected so that the fluid is supplied to the closed chamber (18) from the suction port (19) while the high-pressure fluid is discharged from the discharge port (20).

A donut-shaped back frame (21) fixed to the case (2) is formed in parallel with the end plate (12) on the back side of the end plate (12) in the orbiting scroll (8) with a small gap. Has been done. An inner peripheral end of the rear frame (21) is provided with a boss (10) of the crankshaft (10) via a crank bearing (102).
c) is rotatably supported, and the rear frame (2
Ring tip seals (22, 23) project and are fixed to the upper part near the inner peripheral edge in 1) and the outer peripheral edge of the rear surface of the revolution scroll end plate (12).
The both tip seals (22, 23) are provided in contact with the orbiting scroll end plate (12) or the rear frame (21) which face each other, and the back pressure chamber (24) is provided between the both tip seals (22, 23). It is configured.

That is, the back pressure chamber (24) is defined by the end plate (12) of the orbiting scroll (8) and the rear frame (21). The inner side partition of the back pressure chamber (24) with respect to the orbiting scroll end plate (12) is mounted on the back frame (21) so as to be in sliding contact with the back face of the orbiting scroll end plate (12). 22) and is formed into a circle fixed to the back frame (21). On the other hand, the partition plate outside the back pressure chamber (24) with respect to the orbiting scroll end plate (12) is mounted on the back surface of the orbiting scroll end plate (12) so as to be in sliding contact with the back frame (21). It is formed of a seal (23) and is formed into a circle that revolves together with the revolution scroll (8).

In addition, the end plate (12) of the orbiting scroll (8) is provided with a small hole (25) penetrating vertically so that the back pressure chamber (24) and the closed chamber (18) communicate with each other, and the closed chamber (18 (4) is introduced into the back pressure chamber (24) to press the revolution scroll (8) toward the fixed scroll (7).

Further, the back pressure chamber (24) is provided with concave grooves (26, 27) in the rear frame (21) on the lower surface and the end plate (12) on the upper surface, and both concave grooves (26, 27) are partially formed. Are formed so as to overlap with each other, and as the orbiting scroll (8) revolves, the end plate side groove (27) becomes the frame side chip seal (22) and the frame side recess groove (26) becomes the end plate side chip seal ( 23) so that they do not interfere with each other. This double groove (26,2
In 7), pressure drop due to fluid leakage occurs near the tip seals (22, 23), so this pressure gradient is prevented and the back pressure is evenly distributed to the end plate (12) facing the back pressure chamber (24). The back groove of the back pressure chamber (24) is a main part of the back groove (26, 27).

The frame side tip seal (22) is attached to the crank spindle (10
It is installed concentrically with the shaft center (02) of a), and the end plate side chip seal (23) is the bearing center (01) of the scroll bearing (10b).
And the center of pressure (03) of the back pressure chamber (24) is concentrically arranged with the center of the scroll bearing (01) (movable fulcrum) with respect to the center of the crankshaft (02) (center of revolution) and the eccentric direction. It is located so as to be eccentric from the center (01). Therefore, as shown in FIG. 2, the pressure center (03) on the plan view is derived from the following equation.

X = r × {D1 ² / (D2 ² −D1 ² )} …… X: Distance between scroll bearing center (01) and pressure center (03) r: Scroll bearing center (01) and crank spindle center (02) Distance (revolution radius) D1: Diameter of frame side chip seal (22) (back pressure chamber (2
4) Inner diameter) D2: Diameter of end plate side tip seal (23) (outer diameter of back pressure chamber (24)) Incidentally, (28) in FIG. 3 is a sump of lubricating oil, which is the crankshaft ( Oil is supplied to the crank bearings (101, 102) from an oil supply passage (103) provided in 10a). In the fluid that has sucked low-pressure fluid from the suction pipe (5), has passed through the lower portion of the case (2) and the air gap of the electric motor (9), has passed through the upper and lower ports (15), and has flowed into the balancer chamber (104). The mist-like oil in the balancer chamber (10d) is rotated by the rotation of the balancer (10d).
It collides with the side wall of 4) and returns from the lower part of the side wall to the oil sump (28) through the passage (29).

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

First, the fluid is supplied into the case (2) through the suction pipe (5) and flows into both scrolls (7, 8) through the suction port (19). On the other hand, the orbiting scroll (8) has a crankshaft (1
0) and revolves, and as shown in FIGS. 8 (a) to (d), the closed chamber (18) is sequentially formed and contracted, and the fluid is enclosed in the closed chamber (18) and compressed. , Becomes a high-pressure fluid and is discharged from the discharge port (20).

When the orbiting scroll (8) revolves, centrifugal force (F1) and tangential and normal direction fluid forces (F3, F2) are generated as shown in Fig. 9, of which the normal of the crankshaft (10) The moment due to the centrifugal force (F1) acts strongly in the direction and acts on the bearing center point (04) of the scroll shaft (12a) as a covering moment for inclining the revolution scroll (8).

On the other hand, fluid pressure is introduced into the back pressure chamber (24) from the closed chamber (18) through the small hole (25) and presses the revolution scroll (8) against the fixed scroll (7). It is considered that the total back pressure resultant force (F4) of this back pressure chamber (24) acts on the pressure center (03), and this pressure center (03) is the center of the scroll bearing (01) with respect to the crank spindle (02). ) Is further eccentric to the eccentric direction, and the moment due to this back pressure resultant force (F4) is opposite to the overturning moment due to the centrifugal force (F1) with respect to the bearing center point (04) and cancels the covering moment. It will be.

Here, the moment Mr about the bearing center point (04) (the overturning moment component in the radial direction of the crankshaft (10)) is expressed by the following equation.

Mr = F1 × h1−F2 × (h2 + H / 2) −Ft × (r / 2) ……
H: Height of wrap (14) h1: Center of gravity of bearing (04) and orbiting scroll (8) G
Distance h2: Distance between the bearing center point (04) and the top surface of the end plate (12) Ft: Fluid force in the axial direction In this equation, the first term is the component due to centrifugal force F4, Grows to. Therefore, the back pressure resultant force F4 that cancels out this moment Mr is expressed by the following equation.

F4 = Mr / X = Mr × {(D2 ² −D1 ² ) / D1 ² } × (1 / r)
...... In addition, when reducing the above-mentioned moment Mr without canceling it, the effect of the back pressure resultant force F4, that is, the amount of reduction of the moment
dMr is expressed by the following equation.

dMr = F4 × X ... And the overturning moment Ms in the radial direction that actually acts on the revolution scroll (8) is Ms = Mr−dMr.

Therefore, the inner diameter (D1) and the outer diameter (D2) of the back pressure chamber (24) are kept in a relationship of D2> D1 + 2r so that the inner and outer circles do not interfere with each other, and the inner diameter (D1) is increased and the outer diameter ( When D2) is set small, the rollover moment in the radial direction can be more effectively canceled or reduced.

(Embodiment 2) This embodiment 2 is shown in FIG. 4, in which the outer periphery of the back pressure chamber (30) surrounds the end face of the end plate (12) of the revolution scroll (8) and the rear frame (21) and the fixed scroll ( 7) Flange (11
It is formed by a) and. That is, the back pressure chamber (30)
The inner partition in is formed by a chip seal (22) mounted on the rear frame (21) so as to be in sliding contact with the rear surface of the end plate (12) of the orbiting scroll (8) in the same manner as in the first embodiment. The back pressure chamber (30) is formed so as to include the outside of the end plate (12) in contact with the seal (22).

Further, in the back pressure chamber (30) in the present embodiment, the partition portion outside the revolution scroll end plate (12) is a sliding portion (110) between the flange (11a) and the end plate (12) of the revolution scroll (8). ) Corresponding to the partition of the back pressure chamber (24) with respect to the revolving scroll end plate (12) formed by the end plate side tip seal (23) in the first embodiment, the sliding contact part (110). ) Is provided with a seal member (111).

On the other hand, the small hole (31) that connects the back pressure chamber (30) and the closed chamber (18) is composed of an L-shaped refraction path, and one end of the end plate (12) forms the closed chamber (18). Is opened on the upper surface of the end plate, descends from this front surface, bends at a right angle in the middle, and the other end is opened on the end surface of the end plate (12). Other configurations and operations are similar to those of the first embodiment.

(Embodiment 3) In this embodiment, a back pressure chamber (32) is provided on the back side (upper side in the drawing) of the fixed scroll (7), and the back pressure chamber (30) is shown in FIG. It is formed similarly to the second embodiment.

That is, the cover (33) is mounted over the flange (11a) of the fixed scroll (7) to form the back pressure chamber (32), and the small hole (34) is formed in the end plate (11) of the fixed scroll (7). Perforated closed chamber (18) and back pressure chamber (32)
Are in communication. Further, a small hole (35) is also formed in the flange (11a) in the cover (33) to allow the back pressure chamber (3
2) and the back pressure chamber (30) are in communication.

Therefore, the fluid pressure in the closed chamber (18) is introduced into the back pressure chamber (32) through the small hole (34) and then into the back pressure chamber (30) through the small hole (35). It will be. Other configurations and operations are similar to those of the second embodiment.

(Embodiment 4) This embodiment is shown in FIGS. 6 and 7 and has two back pressure chambers (36, 37) formed therein.

That is, the ring-shaped tip seal (38) contacting the rear frame (21) is provided at the center of the rear face of the end plate (12) of the orbiting scroll (8), and the end plate (12) is provided at the center of the rear frame (21).
The ring-shaped tip seals (39) that are in contact with the back surface of the first back pressure chamber (3
In (6), the outer side of the frame side tip seal (39) is configured as the second back pressure chamber (37).

The second back pressure chamber (37) is the back pressure chamber (30) of the second and third embodiments.
Similarly to the above, it is formed so as to include the outer peripheral portion of the end plate (12). Further, the second back pressure chamber (37) is formed to have a higher pressure than the first back pressure chamber (36), and for example, although not shown, the first back pressure chamber (36)
Is connected to the closed chamber (18) in the early stage of contraction, and the second back pressure chamber (37) is connected to the closed chamber (18) in the final stage of contraction.

Therefore, the pressure center of the first back pressure chamber (36) is eccentric to the side opposite to the eccentric direction of the scroll bearing center (01), but the second back pressure chamber (37) is eccentric to the scroll bearing center (01). Since the second back pressure chamber (37) is eccentric, and the second back pressure chamber (37) has a high pressure, the entire center of pressure is eccentric in the eccentric direction of the scroll bearing center (01) as in the first to third embodiments. By providing these two back pressure chambers (36, 37), the sealing property of the back pressure chambers (36, 37) is improved, and in the case of the high pressure sealed case (2), that is, the space (130) is at high pressure. It is effective for the area. Other configurations and operations are similar to those of the second embodiment.

Although each of the embodiments has been described with reference to the compressor, the present invention can be applied to a drive machine, an expander, etc. by reversing the fluid flow.

Further, the invention according to claim 1 and claim 2 may be a seal mechanism using pressure oil such as a static pressure generating groove in addition to the tip seal (22, 23, 38, 39).

Further, the tip seals (22, 23, 38, 39) do not have to be circular and the centers of the shapes may coincide with 01 and 02, respectively.

(Effects of the Invention) As described above, according to the scroll fluid device of the present invention,
A back pressure chamber is provided on the back side of the orbiting scroll, and in order to make the pressure center of the back pressure chamber eccentric from the movable fulcrum in an approximately eccentric direction of the movable fulcrum with respect to the revolution center of the orbiting scroll, the overturning moment due to centrifugal force is caused by the back pressure. Since it can be offset or reduced by the moment, the orbiting scroll can be supported so as not to tilt with respect to the fixed scroll.

Therefore, it is possible to largely prevent the one-sided contact of the revolving scroll at the time of high-speed rotation, so that abrasion and seizure can be prevented in advance. Further, since it is possible to prevent the generation of the gap in the axial direction, it is possible to prevent the volume efficiency from lowering and further improve the reliability.

[Brief description of drawings]

FIGS. 1 to 8 show an embodiment of the present invention, and FIGS.
1 shows a first embodiment, FIG. 1 is a schematic sectional side view of a scroll mechanism, FIG. 2 is a plan view of a back pressure chamber, FIG. 3 is a sectional view of a scroll fluid device, and FIG. 5 is a sectional view of the scroll fluid device of the third embodiment, FIG. 6 is a schematic sectional side view of the scroll mechanism of the fourth embodiment, and FIG. 7 is a plan view of the back pressure chamber. 8 (a), (b), (c), and (d) are schematic plan views showing the operation of the fixed and revolution scrolls, and FIG. 9 is a schematic side view of the revolution scroll showing the action relationship of forces. Figures 10-13
FIG. 10 shows a conventional example, FIGS. 10 and 11 are sectional side views of a scroll mechanism, FIG. 12 is a plan view of an orbiting scroll, and FIG.
The figure is a side view of the same section. (1) ... scroll fluid device, (3) ... scroll mechanism, (7) ... fixed scroll, (8) ... revolving scroll, (10) ... crank shaft, (10a) ... crank main shaft, ( 10b) …… Scroll bearing, (11,12) …… End plate, (13,14) …… Wrap, (17) …… Contact, (18)…
… Closed room, (21) …… Rear frame, (22,23), (38,
39) …… Tip seal, (24,30,36,37) …… Back pressure chamber,
(26,27) …… Concave groove, (01) …… Scroll bearing center,
(02) …… Crank spindle center, (03) …… Pressure center, (F
1) ... centrifugal force.

Claims (4)

[Claims] 1. A fixed scroll (7) having a wrap (13) standing upright on the front surface of an end plate (11) and an orbiting scroll (8) having a wrap (14) standing upright on the front surface of the end plate (12). And the wraps (13, 14) mesh with each other, and the orbiting scroll (8) is the fixed scroll (7).
It is supported by a movable fulcrum (01) that is eccentric with respect to the fixed scroll (7) and is prevented from rotating on the fixed scroll (7) so that it can freely revolve, and the side surfaces of both wraps (13, 14) come into contact with each other at multiple points. , And a closed chamber (18) is formed between the wraps (13, 14) in contact with each other, while a back pressure chamber (24/30 / ...) is provided on the rear side of the end plate (12) in the revolution scroll (8). ) Is formed and the orbiting scroll (8) is pressed toward the fixed scroll (7) side, and the pressure center (03) of the back pressure chamber (24/30 / ...) is the orbital center (0) of the orbiting scroll (8). 02) movable fulcrum (0
A scroll fluid device characterized in that it is located eccentrically from the movable fulcrum (01) substantially on the eccentric direction line of 1). 2. The back pressure chamber (24/30 / ...) is partitioned by at least an end plate (12) of an orbiting scroll (8) and a frame (21) provided on the back side of the end plate (12). The inner partition of the back pressure chamber (24/30 / ...) with respect to the end plate (12) of the revolution scroll (8) is a circle fixed to the frame (21), and the outer partition is the revolution scroll (8). The scroll fluid device according to claim 1, wherein the scroll fluid device is a circle that revolves together with the scroll fluid. 3. The back pressure chamber (24) is defined by an end plate (12) of an orbiting scroll (8) and a frame (21) provided on the back side of the end plate (12), The partition part inside the back pressure chamber (24) with respect to the end plate (12) of (8) is attached to the frame (21) so as to be in sliding contact with the end plate (12) of the revolution scroll (8). 22), and the partition part outside the back pressure chamber (24) with respect to the end plate (12) of the orbiting scroll (8) is slidably in contact with the frame (21). The scroll fluid device according to claim 1, wherein the scroll fluid device is formed of a ring-shaped tip seal (23) mounted on the scroll fluid. 4. The back pressure chamber (30) comprises a mirror plate (12) of an orbiting scroll (8), a frame (21) provided on the back side of the mirror plate (12), and a fixed scroll (7). An orbiting scroll (8) continuous with the outer peripheral edge of the end plate (11)
Flange (11a) with which the front surface of the end plate (12) in sliding contact
And a frame (21) so that a partition part inside the back pressure chamber (30) with respect to the end plate (12) of the orbiting scroll (8) slides on the end plate (12) of the orbiting scroll (8). A ring-shaped tip seal (22) attached to the outer periphery of the back pressure chamber (30) with respect to the end plate (12) of the orbiting scroll (8), and the flange (11a) and the orbiting scroll (8). 3. The scroll fluid device according to claim 1, wherein the scroll fluid device is formed of a sliding portion (110) with respect to the end plate (12).