WO2001098661A1

WO2001098661A1 - Scrawl compressor

Info

Publication number: WO2001098661A1
Application number: PCT/JP2001/005243
Authority: WO
Inventors: Takahide Itoh; Chikako Sasakawa; Susumu Matsuda
Original assignee: Mitsubishi Heavy Industries, Ltd.
Priority date: 2000-06-22
Filing date: 2001-06-20
Publication date: 2001-12-27
Also published as: CN1159529C; DE60108871T2; CN1383472A; DE60108871D1; JP2002005046A; EP1293674A1; KR20020025231A; KR100436221B1; US20020114719A1; EP1293674A4; EP1293674B1

Abstract

A scroll compressor comprising a back pressure chamber (HR) formed at the other side of an end plate (12a) of a stationary scroll (12), the stationary scroll (12) being pressed against a revolving scroll (13) by introducing a compressed fluid into the back pressure chamber (HR), wherein a level difference is provided between end plates (12a, 13a) of the stationary and revolving scrolls (12, 13) and the upper edges of the walls (12b, 13b) of the stationary and revolving scrolls (12, 13) are of stepped shape to prevent leakage of the fluid.

Description

Specification

Scroll compressor Technical field

The present invention relates to a scroll compressor provided in an air conditioner, a refrigeration system, and the like. Background art

In a scroll compressor, a fixed scroll and an orbiting scroll are arranged in combination with spiral-shaped walls, and the volume of the compression chamber formed between the walls by revolving the orbiting scroll with respect to the fixed scroll. Is gradually reduced to compress the fluid in the compression chamber.

The design compression ratio of the scroll compressor is as follows: The maximum volume of the compression chamber (the volume immediately before the compression chamber disappears due to the disengagement of the walls and the compression chamber disappears) (The volume at the time when the chamber was formed), and is expressed by the following formula (I).

V i = {Α (θ sue) · L} / {A (Θ top) · L} = A (Θ sue) / A (Θ top) ··· (I)

In equation (I), Α (θ) is a function that represents the cross-sectional area parallel to the revolving surface of the compression chamber whose volume changes according to the revolving angle of the orbiting scroll Θ, and Θ sue is when the compression chamber has the maximum volume. Θ top is the turning angle of the turning scroll when the compression chamber has the minimum volume, and L is the wrap (overlap) length between the walls.

Conventionally, in order to increase the compression ratio V i of the scroll compressor, a method has been adopted in which the number of turns of the walls of both scrolls is increased to increase the cross-sectional area A (0) of the compression chamber at the maximum capacity. . However, in the conventional method of increasing the number of windings on the wall, the outer shape of the scroll is enlarged and the compressor itself is enlarged, so that it is difficult to adopt the method in an air conditioner for an automobile or the like whose size is severely restricted. There was a problem.

In order to solve the above problems, Japanese Patent Publication No. 60-17956 proposes the following technology. The fixed scroll 50 shown in FIG. 12A is provided with an end plate 50 a and a spiral wall 50 b erected on one side of the end plate 50 a. I have. The orbiting scroll 51 is shown in FIG. 12B. Similarly to the fixed scroll 50, the orbiting scroll 51 also includes an end plate 51a, and a spiral wall 51b provided on one side of the end plate 51a.

The fixed scroll 50 and the orbiting scroll 51 are located on the side of the end plates 50a, 51a, π (rad) from the outer peripheral edge of the spiral of the wall bodies 50b, 51b, and the center side is A step 52 is formed that is high and the outer end is low. Further, corresponding to the steps 52 of the end plates 50a and 51a, the center of the scroll 50a and 51b is provided on the spiral upper edges of the walls 50b and 51b. A step portion 53 that is low and has a high outer peripheral end side is formed. Tip seals 54 and 56 for improving airtightness are provided on the upper edges of the walls 50b and 51b.

In the scroll compressor as described above, the fixed scroll 50 and the orbiting scroll 51 are engaged with the respective walls 50b and 51b to form the compression chamber P having the maximum volume. Fig. 13B is a sectional view of the compression chamber P along the spiral direction.

As can be seen from FIG. 13B, the wrap length L 1 on the outer peripheral end side of the step portion 52 is longer than the inner wrap length Ls. For this reason, it can be seen that the maximum volume of the compression chamber P is increased by the length of the wrap outside the step 52 as compared with the case where the wrap length is uniform. Therefore, it is possible to improve the design compression ratio without increasing the number of windings of the wall.

However, in the conventional scroll compressor, as shown in FIG. 14, depending on the phase of the orbiting scroll 51, the tip seal 56 near the step 53 is fixed to the end plate 50a of the fixed scroll 50. (Part indicated by reference symbol a in the figure). Similarly, the tip seal 54 on the fixed scroll 50 side is also separated from the end plate 51 a of the orbiting scroll 51 in the vicinity of the step 52.

For this reason, the chip seals 54 and 56 may fall from the walls 50b and 51b, respectively, or the chip seals 54 and 56 may be broken, causing fluid leakage at the step. There was a problem. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scroll compressor that can prevent fluid leakage. Disclosure of the invention

The scroll compressor according to the present invention includes: a fixed scroll having a spiral wall provided upright on one side surface of an end plate; and a spiral wall body provided upright on one side surface of the end plate. An end plate of at least one of the fixed scroll and the orbiting scroll, wherein the scroll compressor includes a orbiting scroll supported so as to be capable of revolving orbit while being prevented from rotating by combining the respective wall bodies. A back-pressure chamber is formed on the other side of the scroll, and the fluid compressed by the two scrolls is introduced into the back-pressure chamber, whereby the one scroll is pressed against the other scroll. The end plate of at least one of the fixed scroll and the orbiting scroll has, on one side surface, a height that is higher at a center portion side along a vortex of a wall body. A step formed so as to be lower on the peripheral end side is provided, and an upper edge of a wall of the other scroll of the fixed scroll or the orbiting scroll corresponds to a step of the end plate. It is characterized in that it is divided into portions and has a stepped shape in which the height of the portion is lower at the center of the vortex and higher at the outer peripheral end.

In this scroll compressor, one scroll is pressed against the other scroll by the compressed fluid introduced into the back pressure chamber. For this reason, the compression chamber is sealed without using a tip seal as in the related art, and leakage of fluid in the compression chamber can be prevented. Therefore, problems such as dropping and breakage of the tip seal caused by separation of the tip seal from the end plate do not occur.

Further, in the scroll compressor of the present invention, an elastic body for pressing at least one of the fixed scroll and the orbiting scroll against the other scroll may be provided.

In this scroll compressor, one scroll is pressed against the other scroll by the elastic body, so that leakage of fluid is prevented.

Further, in the scroll compressor according to the present invention, the back pressure chamber may be formed on the other side of the fixed scroll. In this scroll compressor, the compression chamber is sealed by pressing the fixed scroll toward the orbiting scroll.

In the scroll compressor of the present invention, the back pressure chamber may be formed on the other side of the orbiting scroll.

In this scroll compressor, the compression chamber is sealed by pressing the orbiting scroll toward the fixed scroll.

Further, in the scroll compressor, a bearing member is provided for revolving orbiting by being fitted to the other side of the end plate of the orbiting scroll, and the back pressure chamber is provided between the orbiting scroll and the bearing member. May be formed between them.

In this scroll compressor, the compressed fluid introduced into the back pressure chamber exerts pressure to push and spread between the orbiting scroll and the bearing member. As a result, the orbiting scroll is pressed against the fixed scroll. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view showing the overall configuration of a scroll compressor shown as a first embodiment of the present invention.

FIG. 2 is a perspective view of a fixed scroll used in the scroll compressor.

FIG. 3 is a perspective view of an orbiting scroll used in the scroll compressor.

FIG. 4 is a cross-sectional view along the vortex of the fixed scroll or the orbiting scroll. FIG. 5 is a diagram showing a process of fluid compression when the scroll compressor is driven. FIG. 6 is a diagram showing a process of fluid compression when the scroll compressor is driven. FIG. 7 is a diagram showing a process of fluid compression when the scroll compressor is driven. FIG. 8 is a diagram showing a process of fluid compression when the scroll compressor is driven. FIGS. 9A to 9D are views showing shapes of expanded compression chambers of the scroll compressor. FIG. 10 is a cross-sectional view showing the overall configuration of a scroll compressor shown as the second embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the overall configuration of a scroll compressor shown as the third embodiment of the present invention.

Figures 128 and 12B show fixed scrolls used in conventional scroll compressors. And a perspective view of the orbiting scroll.

FIGS. 13 and 13B are diagrams showing a compression chamber at the maximum capacity in a conventional scroll compressor.

FIG. 14 is a cross-sectional view showing a sliding state of a tip seal in the vicinity of a step portion of a conventional scroll compressor. BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a scroll compressor according to the present invention will be described with reference to FIGS. 1 to 9A to 9D.

FIG. 1 shows a configuration of a back-pressure scroll compressor shown as one embodiment of the present invention. This back-pressure scroll compressor has a sealed housing 1, a discharge cover 2, which separates a housing 1 內 into a high-pressure chamber HR and a low-pressure chamber LR, a frame 5, a suction pipe 6, a discharge pipe 7, and a motor 8 , Rotating shaft 9, rotation prevention mechanism 10, fixed scroll 12, and orbiting scroll 13 meshing with fixed scroll 12.

As shown in FIG. 2, the fixed scroll 12 has a configuration in which a spiral wall 12b is erected on one side surface of an end plate 12a. Like the fixed scroll 12, the orbiting scroll 13 has a structure in which a spiral wall 13b is erected on one side of the end plate 13a, and particularly the wall 13b. Has substantially the same shape as the wall 1 2b on the fixed scroll 12 side.

As shown in FIG. 3, the orbiting scrolls 13 are mutually eccentric with respect to the fixed scrolls 12 by the orbital revolving radius and shifted in phase by 180 °. And assembled. .

In such a back-pressure scroll type fluid machine, the fixed scroll 12 is not completely fixed to the frame 5 by a bonolet or the like, and is movable within a restricted range.

A cylindrical boss A is formed on the back side of the orbiting scroll 13, and an eccentric pin 9 a provided at the upper end of a rotary shaft 9 driven by a motor 8 and orbiting is inserted into the boss A. ing. As a result, the orbiting scroll 1 ³ becomes the fixed scroll 1 2 In addition to the turning motion, the rotation is prevented by the action of the rotation preventing mechanism 10.

On the other hand, the fixed scroll 12 is supported by the frame 5 fixed to the housing 1 via a supporting panel (elastic body) 11 so as to float freely, and is pressed against the orbiting scroll 13. . A discharge port 15 for compressed fluid is provided at the center of the back surface of the end plate 3a. Around the discharge port 15, there is provided a cylindrical flange 16 protruding from the back surface of the end plate 12 a of the fixed scroll 12, and the circular flange 16 is a cylinder on the discharge charge cover 2 side. Mated with flange 17. It is necessary to separate the high-pressure chamber HR and the low-pressure chamber LR at the part where these cylindrical flanges 16 and 17 are fitted, and apply high pressure (back pressure) to the back of the fixed scroll 12 to push it down. A seal structure using a seal member 18 is employed. This seal member 15 has a U-shaped cross section. The high-pressure chamber HR in this case also functions as a back-pressure chamber for applying a high-pressure discharge pressure to the back of the fixed scroll 12. '

The end plate 1 2a of the fixed scroll 1 2 has one side on which the wall 1 2b is erected, and is high at the center and low at the outer end along the vortex direction of the wall 1 2b. The step portion 42 is formed.

Similarly to the end plate 1a, the end plate 13a on the orbiting scroll 13 side is on one side where the wall body 13b is erected, and at the center side along the vortex direction of the wall body 13b. A step 43 is formed so as to be higher and lower on the outer peripheral end side.

The steps 42 and 43 are located at positions π (rad) ahead of the outer edges of the walls 1 2 b and 13 b with reference to the center of the spiral of the walls 12 b and 13 b, respectively. It is provided in.

The bottom surface of the end plate 1 2a has a shallow bottom surface 12 f provided from the center portion and a deep bottom surface 12 g provided from the outer peripheral edge due to the formation of the step portion 42. Is divided into two parts. Between the adjacent bottom surfaces 12 f and 12 g, there is a stepped portion 42, and there is a connecting wall surface 12 h which connects the bottom surfaces 12 f and 12 g and is vertically cut. Similarly to the end plate 1a, the bottom surface of the end plate 1a is provided with a shallow bottom surface 13f provided from the center and the outer peripheral end due to the formation of the step 43. The deep bottom of the shaved bottom is divided into two parts of 13 g. Between the adjacent bottom surfaces 13 f and 13 g, there is a step portion 43, and there is a connecting wall surface 13 h that connects the bottom surfaces 13 f and 13 g and is vertically cut.

The wall 12b of the fixed scroll 12 corresponds to the step 43 of the orbiting scroll 13, and the upper edge of the spiral is divided into two parts, and is lower at the center of the vortex. It has a high stepped shape on the outer peripheral end side. Similarly to the wall 1 2b, the orbiting scroll 1 3 side wall 1 3b also corresponds to the stepped portion 42 of the fixed scroll 1 2 and the spiral upper edge is divided into two portions, and The shape is low at the center and high at the outer edge.

Specifically, the upper edge of the wall 1 2b is divided into two parts: a lower upper edge 1 2c provided near the center and a higher upper edge 1 2d provided near the outer edge. A connecting edge 12 e that is perpendicular to the turning surface exists between the adjacent upper edges 12 c and 12 d. Like the wall 1 2b, the upper edge of the wall 13b is also composed of a lower upper edge 13c near the center and a higher upper edge 13d near the outer edge. It is divided into parts, and between the adjacent upper edges 13c and 13d, there is a connection edge 13e that connects the two and is perpendicular to the turning surface.

When viewed from the direction of the orbiting scroll 13, the connecting edge 1 2 e is a half having a diameter that is smoothly continuous with the inner and outer sides of the wall 1 2 b when viewed from the direction of the orbiting scroll 13 and has a wall thickness equal to the wall 1 2 b. The connecting edge 13e, like the connecting edge 12e, has a semicircular shape that smoothly continues to the inner and outer sides of the wall 13b and has a diameter equal to the wall thickness of the wall 13b. Has made. When the end plate 12a is viewed from the direction of the turning axis, the connecting wall surface '12h has an arc that matches the envelope drawn by the connecting edge 13e with the turning of the orbiting scroll. Similarly to the connecting wall 12h, the 13h has an arc corresponding to the envelope drawn by the connecting edge 12e.

Note that, in the present example, no tip seal is provided on the upper edge of the wall 1 2 b of the fixed scroll 1 2 and the wall 13 b of the orbiting scroll 13, and the walls 1 2 b, 1 3 The compression chamber C, which will be described later, is sealed by pressing the end face of b against the end plates 12a and 13a.

As shown in FIG. 4, the upper edge 12c and the connection edge 12e of the wall 12b abut each other. The ribs are provided with ribs 1 2 i at the bottom. The rib 12 i is formed integrally with the wall 12 b to form a concave surface that smoothly connects the upper edge 12 c and the connecting edge 12 e to avoid stress concentration. A rib 13i of the same shape is also provided at a portion where the upper edges 13c and 13e abut on the wall 13b for the same reason. A rib 12j is also provided on the end plate 12a at the portion where the bottom surface 12g and the connecting wall surface 12h abut, as if they were overlaid. The rib 12j is formed integrally with the wall 12b as a concave curved surface that smoothly connects the bottom surface 12g and the connecting wall surface 12h to avoid stress concentration. A rib 13 j of the same shape is also provided at a portion of the end plate 13 a where the bottom surface 13 g and the connecting wall surface 13 h meet the force S for the same reason.

The part of the wall 1 2b where the upper edge 1 2d and the connecting edge 1 2e meet, and the part of the wall 1 3b where the upper 緣 13 d and the connecting edge 13 e match, are ribs 1 during assembly. They are chamfered to avoid interference with 3 j and 1 2 j.

When the orbiting scroll 1 3 is assembled to the fixed scroll 1 2, the lower upper edge 1 3 c abuts the shallow bottom 1 2 f, and the upper upper edge 1 3 d abuts the deep bottom 1 2 g I do. At the same time, the lower upper edge 1 2c abuts the shallow bottom 13 f and the higher upper edge 1 2d abuts the deep bottom 13 g. As a result, a compression chamber C is formed between the two scrolls by being divided into end plates 12a and 13a and wall bodies 12b and 13b facing each other.

The compression chamber C moves from the outer peripheral end toward the center with the orbital movement of the orbiting scroll 13, but the connecting edge 12 e is connected to the contact edge of the walls 12 b and 13 b by the connecting edge 1 2 While it is closer to the outer peripheral edge than e, it slides against the connecting wall 13h so that fluid does not leak between the adjacent compression chambers C (one is not in a sealed state) with the wall 12 interposed. As long as the contact points of the walls 12b and 13b are not closer to the outer peripheral end than the connecting edge 12e, the compression chambers C (both in a sealed state) adjacent to each other with the wall 12 interposed therebetween. In order to equalize the pressure, it does not come into sliding contact with the connecting wall surface for 13 h.

Similarly, the compression chamber C adjacent to the connecting edge 13 e with the wall 13 interposed therebetween while the contact point of the walls 1 2 b and 13 b is closer to the outer peripheral end than the connecting edge 13 e. (One side is not in a sealed state) so that the fluid does not leak between the connecting wall 12h and the contact point of the wall 12b, 13 is closer to the outer edge than the connecting edge 13e. While it does not exist, sandwich the wall 1 3 In order to equalize the pressure between the adjacent compression chambers C (both in a sealed state), they do not slide on the connecting wall 12h. The sliding contact between the connecting edge 12 e and the connecting wall surface 13 h and between the connecting edge 13 e and the connecting wall surface 12 h occur synchronously while the orbiting scroll 13 makes one or two rotations.

The process of fluid compression when the scroll compressor configured as described above is driven will be described in order with reference to FIGS.

In the state shown in FIG. 5, the outer peripheral end of the wall 1 2b contacts the outer surface of the wall 13b, and the outer peripheral end of the wall 13b contacts the outer surface of the wall 12b. Fluid is sealed between the end plates 12a and 13a and the walls 12b and 13b, and two compression chambers C with the maximum capacity are located directly opposite each other across the center of the scroll compression mechanism. It is formed. At this point, the connecting edge 12 e and the connecting wall 13 h are in sliding contact with each other, and the connecting edge 13 e and the connecting wall 12 h are in sliding contact with each other, but immediately separate.

In the process of turning from the state in Fig. 5 by the orbiting scroll 13 force S _π / 2 to the state shown in Fig. 6, the compression chamber C moves toward the center while maintaining the sealed state, and gradually reduces the volume. The fluid is compressed, and the compression chamber C0 preceding the compression chamber C also advances toward the center while maintaining a sealed state, and gradually reduces the volume to compress the fluid. In this process, the sliding contact between the connecting edge 12 e and the connecting wall 13 h and between the connecting edge 13 e and the connecting wall 12 h are eliminated, and the two adjacent compression chambers C are equalized.

In the process in which the orbiting scroll 13 orbits by π / 2 from the state in Fig. 6 to the state shown in Fig. 7, the compression chamber C advances toward the center while maintaining the closed state, and the volume gradually decreases to further reduce the volume. The fluid is compressed, and the compression chamber C0 also moves toward the center while maintaining the sealed state, and gradually reduces the volume to compress the fluid continuously. In this process, the connecting edge 12e starts sliding contact with the connecting wall 13h, and the connecting edge 13e starts sliding contact with the connecting wall 12h.

In the state shown in FIG. 7, an open space C1, which later becomes a compression chamber, is formed between the inner surface of the wall 1 2b near the outer peripheral end and the outer surface of the wall 13b located inside the wall. Similarly, an open space C1, which will later become a compression chamber, is formed between the inner surface of the wall 13b near the outer peripheral end and the outer surface of the wall 13b located inside the wall 13b. A low-pressure fluid flows into the space C1 from the low-pressure chamber LR. In the process of turning the orbiting scroll 13 from the state of Fig. 7 by π / 2 and reaching the state shown in Fig. 8, the open space C1 expands toward the center of the scroll compression mechanism while expanding, and is opened. The compression chamber C preceding the space C1 also moves toward the center, and gradually reduces the volume to compress the fluid.

In the process in which the orbiting scroll 13 turns from the state in Fig. 8 further by 7: 2 and returns to the state shown in Fig. 5, the space C1 further increases in size toward the center of the scroll compressor mechanism. However, the compression chamber C preceding the space C1 also moves toward the center while maintaining the sealed state, and gradually reduces the volume to compress the fluid. When the state shown in FIG. 5 is reached, the compression chamber C shown in FIG. 8 corresponds to the compression chamber CO shown in FIG. 5, and the space C1 shown in FIG. 8 corresponds to the compression chamber C shown in FIG. .

Thereafter, by continuing compression, the compression chamber C becomes the minimum volume, and the fluid is discharged from the compression chamber C.

The discharged fluid is introduced into the high-pressure chamber HR. Then, the fixed scroll 12 receives the high back pressure and is pressed against the orbiting scroll 13 side. In the seal member 15, the high pressure fluid is introduced into the U-shaped portion to cause the differential pressure. The sealing is performed between the high-pressure chamber HR and the low-pressure chamber LR by pressing the sealing surfaces toward the vertical surfaces of the cylindrical flanges 16 and 17.

Next, a change in the shape of the compression chamber C will be described.

The change in the size of the compression chamber C from the maximum volume to the minimum volume can be regarded as the compression chamber C in FIG. 5 → the compression chamber C in FIG. 7 → the compression chamber C 0 in FIG. 5 → the compression chamber C 0 in FIG. Here, the expanded shapes of the compression chambers in each state are shown in FIGS. 9A to 9D.

In the state shown in Fig. 9A where the maximum volume is reached, the compression chamber is shaped like a strip with a narrow width in the direction of the pivot axis. The width is the height of the wall 1 2b from the bottom 12 g to the upper edge 12 d on the outer peripheral end side of the scroll compression mechanism (or the wall 1 from the bottom 13 g to the upper edge 13 d). Lap length L 1 which is approximately equal to the height of 3 b), and the height from the bottom 12 f to the upper edge 12 d at the center (or the height from the bottom 13 f to the upper edge 13 d) The wrap length L s (<L 1) is approximately equal to the height of the wall 13 b.

Even in the state shown in Fig. 9B, the compression chamber has an irregular short shape whose width in the direction of Form a book. The width is the wrap length L s on the outer peripheral end of the scroll compression mechanism, and the height from the bottom 12 f to the upper edge 12 c (or from the bottom 13 f to the upper edge 13 c) on the center. The wrap length Lss is approximately equal to the height of the wall 13b.

As the compression further proceeds, the compression chamber has a uniform wrap length L s s as shown in FIG. 9C.

Then, as shown in Fig. 9D, the compression chamber has the minimum volume by minimizing its length.

In the scroll compressor described above, the change in the volume of the compression chamber is caused not only by the decrease in the cross-sectional area parallel to the turning surface as in the conventional case, but also in the direction of the turning axis as shown in FIGS. 9A to 9D. It is caused synergistically by a decrease in width and a decrease in cross-sectional area.

Therefore, the walls 12b, 13b are stepped, and the wrap length of the walls 12b, 13b is changed between the outer peripheral end and the center of the scroll compression mechanism, and the compression chamber C By increasing the maximum volume or decreasing the minimum volume, the compression ratio can be improved as compared with a conventional scroll compressor in which the wrap length between the walls is constant.

Then, by introducing the back pressure into the high-pressure chamber HR, the fixed scroll 1 2 is pressed against the orbiting scroll 13. For this reason, the compression chamber C is sealed without using a tip seal, and efficient compression can be performed without dropping or breaking the tip seal.

Next, a second embodiment of the present invention will be described. In addition, about the same structure as the said 1st Embodiment, the description is abbreviate | omitted using the same code | symbol.

FIG. 10 shows a scroll compressor according to this example. This scroll compressor has a closed housing 2, a suction pipe 23 at the lower part, and a discharge pipe 25 at the upper part. Inside the housing 21, an upper lever drive unit 27 is provided, and a compressor unit 29 is provided at a lower portion. The driving section 27 includes a rotor 27 a fixed to the main shaft 28 and a stator 27 b fixed to the housing 21. The main shaft 28 is rotatably supported by the main bearing 30, and current flows through the stator 27 b Thus, rotational power is given to the main shaft 28 via the rotor 27a.

The compressor section 29 includes a fixed scroll 31 and an orbiting scroll 32. The end plate of the fixed scroll 31 is fixed to the housing 21.

At the center of the end plate of the orbiting scroll 32, a discharge port 33 for compressed fluid is provided. (In this example, unlike the first embodiment, the fixed scroll 31 has a discharge port ( (Refer to reference numeral 15 in Fig. 1) is not provided). On the back side of the orbiting scroll 32, a cylindrical boss A is formed surrounding the opening of the discharge port 33, and the eccentric portion 28a of the main shaft 28 is inserted into the boss A.

Other configurations of the fixed scroll 31 and the orbiting scroll 32 are the same as those of the fixed scroll 12 and the orbiting scroll 13 in the first embodiment, and the end plates are formed with step portions 42, 43, In addition, it is equipped with stepped walls 12b and 13b.

A communication hole 34 is provided in the main shaft 28 so as to penetrate in the axial direction, and connects the discharge port 33 and the discharge pipe 25.

Between the orbiting scroll 32 and the main bearing 30, there is provided an annular sealing member 35 for separating the inside of the housing 21 into a high-pressure chamber (back pressure chamber) HR and a low-pressure chamber LR. ing. The high-pressure chamber HR is formed around the opening of the discharge port 33 on the back side of the orbiting scroll 32.

In this scroll compressor, when the orbiting scroll 32 is revolved orbiting, the compression chamber C moves from the outer peripheral end toward the center, and gradually reduces the volume to compress the fluid. The compression stroke of the fluid is the same as that of the first embodiment, but the compressed fluid is introduced into the high-pressure chamber HR formed on the back side of the orbiting scroll 32 via the discharge port 33. Then, the orbiting scroll 32 is pressed against the fixed scroll 31 with the high back pressure.

In the scroll compressor of this example, the change in the volume of the compression chamber is not caused only by the decrease in the cross-sectional area parallel to the swivel surface as in the conventional case, but as shown in Figs. 9A to 9D. It is caused synergistically by a reduction in the width in the direction and a reduction in the cross-sectional area. Therefore, the walls 12b and 13b are stepped, and the wrap lengths of the walls 12b and 13b are changed between the outer peripheral end and the center of the scroll compression mechanism, and the compression chamber C By increasing the maximum volume or decreasing the minimum volume, the compression ratio can be improved as compared with a conventional scroll compressor in which the wrap length between the walls is constant. -Then, the orbiting scroll 3 2 is pressed against the fixed scroll 3 1 by introducing the back pressure into the high pressure chamber HR. For this reason, the compression chamber C is sealed without using a tip seal, and efficient compression can be performed without dropping or breaking the tip seal.

Next, a third embodiment of the present invention will be described. In addition, about the same structure as the said 1st Embodiment, the description is abbreviate | omitted using the same code | symbol.

FIG. 11 shows a scroll compressor according to the present example. This scroll compressor has an orbiting scroll 13 combined with a fixed scroll 12. The orbiting scroll 13 'is composed of a terminal 13a' and a wall 13b standing upright on one side of the end plate 13a '. Except for the end plate 13a ', the configuration is the same as that of the orbiting scroll 13 of the first embodiment.

The end plate 13a 'of the orbiting scroll 13 has an annular groove 45 on the back side (the other side of the end plate 13a'). A bearing member 46 is fitted in the annular groove 45. An annular protrusion 46 a corresponding to the annular groove 45 is formed on the bearing member 46, and the annular protrusion 46 a is fitted into the annular groove 45. A seal member 47 is provided on the seal surface between the annular protrusion 46a and the annular groove 45, so that a gap between the turning scale 13 'and the bearing member 46 is reduced. It is separated into a high pressure chamber (back pressure chamber) HR 'on the center side and a low pressure chamber LR on the outside. The end plate 13a 'has a communication hole 48 communicating the high-pressure chamber HR' and the compression chamber C.

A cylindrical boss A is formed on the bearing member 46 and extends in a direction opposite to the annular projection 46 a. An eccentric pin 9 a provided at the upper end of the rotating shaft 9 and rotating is inserted into the boss A. . The bearing member 46 is supported in a state where its rotation is prevented by the rotation preventing mechanism 10. Thus, the bearing member 46 is revolved orbitally by the rotation of the rotary shaft 9, and the motion is transmitted to the orbiting scroll 13 ', so that the orbiting scrolls 13 and revolve.

In this scroll compressor, when the orbiting scroll 13 ′ is made to revolve orbit, the compression chamber C moves from the outer peripheral end toward the center, and gradually reduces the volume to compress the fluid. The compression stroke of the fluid is the same as that of the first embodiment, but the compressed fluid is discharged from the discharge port 15 and introduced into the high-pressure chamber H R ′ through the communication hole 48. The high-pressure fluid introduced into the high-pressure chamber HR exerts pressure so as to separate the orbiting scroll 13 'and the bearing member 46 from each other, whereby the orbiting scrolls 13 and 13 are pressed against the fixed scroll 12 Can be

In the scroll compressor of the present example, the change in the volume of the compression chamber is not caused only by the decrease in the cross-sectional area parallel to the orbital surface as in the conventional case, but as shown in Figs. 9A to 9D. It is caused synergistically by the reduction of the width in the direction and the reduction of the cross-sectional area.

Therefore, the walls 12b and 13b are stepped, and the wrap lengths of the walls 12b and 13b are changed between the outer peripheral end and the center of the scroll compression mechanism, and the compression chamber C By increasing the maximum volume or decreasing the minimum volume, the compression ratio can be improved as compared with a conventional scroll compressor in which the wrap length between the walls is constant.

Then, by introducing the back pressure into the high-pressure chamber H R ′, the fixed scroll 12 and the orbiting scroll 13 ′ are pressed against each other. Therefore, the compression chamber C is sealed without using a tip seal, and efficient compression can be performed without dropping or breaking the tip seal.

In the above embodiment, the connecting edges 12 e and 13 e are formed perpendicular to the turning surface of the orbiting scroll 13, and the connecting walls 12 h and 13 h are correspondingly perpendicular to the turning surface. It is formed, but the connecting edges 12 e and 13 6 and the connecting walls 12 and 13 h do not need to be perpendicular to the turning surface as long as they keep their correspondence, for example, with respect to the turning surface. It may be formed so as to be inclined.

The connecting edges 1 2 e and 13 e do not have to be semicircular, It may be. In this case, the envelope drawn by the connecting edges 12 e and 13 e does not become an arc, so that the connecting walls 12 h and 13 h also do not become arcs.

Furthermore, the formation portions of the step portions 42 and 43 are not limited to one, and may be provided at a plurality of portions. Industrial applicability

As described above, in the scroll compressor of the present invention, the compressed fluid introduced into the back pressure chamber, and therefore _c the one scroll is pressed against the other scroll, compressed without using a conventional tip seal Since the chamber is sealed, the tip seal does not fall or break, preventing leakage of fluid and enabling efficient compression.

Claims

The scope of the claims

1. A fixed scroll having a spiral wall provided on one side of the end plate, and a spiral wall provided on one side of the end plate. In a scroll compressor having a revolving scroll supported to be capable of revolving revolving motion while being prevented from rotating in combination,

A back pressure chamber is formed on the other side surface of the end plate of at least one of the fixed scroll and the orbiting scroll, and the fluid compressed by the two scrolls is introduced into the back pressure chamber so that the one of the scrolls is introduced. The scroll is pressed against the other scroll,

Further, the end plate of the scroll of at least one of the fixed scroll and the orbiting scroll has a height on the one side surface along the vortex of the wall body, which is higher on the center side and lower on the outer peripheral end side. The upper edge of the wall of the other scroll of the fixed scroll and the orbiting scroll corresponds to the step of the end plate, and is divided into a plurality of portions. A scroll compressor with a stepped shape in which the height of the part is lower at the center of the vortex and higher at the outer peripheral end.

2. The scroll compressor according to claim 1,

A scroll compressor provided with an elastic body that presses at least one of the fixed scroll and the orbiting scroll against the other scroll.

3. The scroll compressor according to claim 1,

The back pressure chamber is a scroll-type compressor formed on the other side of the fixed scroll.

4. The scroll compressor according to claim 1,

The scroll type compressor in which the back pressure chamber is formed on the other side of the orbiting scroll.

5. The scroll compressor according to claim 4, wherein

A bearing member is provided for revolving orbiting by being fitted to the other side of the end plate of the orbiting scroll, and the back pressure chamber is a scroll compression formed between the orbiting scroll and the bearing member. Machine.