EP3739213B1

EP3739213B1 - Scroll fluid machine

Info

Publication number: EP3739213B1
Application number: EP19756906.4A
Authority: EP
Inventors: Hajime Sato; Yoshiyuki Kimata; Masashi Hamano; Takahide Ito
Original assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2018-02-21
Filing date: 2019-01-11
Publication date: 2023-09-20
Anticipated expiration: 2039-01-11
Also published as: JP6612376B2; JP2019143551A; CN111742142B; EP3739213A1; EP3739213A4; WO2019163322A1; EP3739213C0; CN111742142A

Description

[Technical Field]

The present invention relates to a scroll fluid machine.

[Background Art]

Generally, there is known a scroll fluid machine in which a fixed scroll member and a turning scroll member provided with respective spiral walls on respective end plates are engaged and revolved to compress or expand fluid.
As such a scroll fluid machine, a so-called stepped scroll compressor disclosed in PTL 1 is known. In this stepped scroll compressor, respective step sections are provided at positions along the spiral directions of tooth tip surfaces and tooth bottom surfaces of spiral walls of a fixed scroll and a turning scroll, and the height of the outer circumferential side of the wall is made higher than the height of the inner circumferential side of the wall with each step section as a boundary. The stepped scroll compressor performs compression not only in the circumferential direction of the walls, but also in the height direction (three-dimensional compression), and therefore it is possible to increase displacement and increase compressor capacity compared to a general scroll compressor with no step section (two-dimensional compression). Other scroll compressors are disclosed in PTL 2 and PTL 3.

[Citation List]

[Patent Literature]

[PTL 1] Japanese Unexamined Patent Application, Publication No. 2015-55173
[PTL 2] Chinese Utility Model Application, Publication No. 204003446
[PTL 3] US patent, Publication No. 5496161 .

[Summary of Invention]

[Technical Problem]

However, the stepped scroll compressor has a problem that fluid leakage at the step sections is large. Further, there is a problem that stress is concentrated on root portions of the step sections, and strength is reduced.
To cope with the above, the inventors are considering providing continuous inclined sections in place of the step sections provided on the walls and the end plates.
In a case where the inclined sections are provided on the walls and the end plates, and flat sections connected to the inclined sections are provided, inclined connecting sections are provided between the inclined sections and the flat sections. In the inclined connecting sections, the following failures may occur.
That is, in each inclined connecting section, when the inclined section and the flat section are connected without any modification, the shape discontinuously changes, and machining becomes difficult. Therefore, a burr or sagging is easily generated on the tooth tip or the tooth bottom. When a burr or sagging is generated on the tooth tip or the tooth bottom, the shape deviates from a desired shape, and the inclined connecting section projects on the facing tooth bottom or tooth tip. Therefore, excessive contact may occur between the tooth tip and the tooth bottom.
In a case where a tip seal is installed in a groove section formed in the tooth tip of a wall, the inclined connecting section is provided in the groove bottom of the groove section. When a burr or sagging is generated on this groove bottom inclined connecting section, the tip seal is caught, movement of the tip seal in accordance with turning movement is restricted, and desired seal performance may not be able to be exhibited.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a scroll fluid machine in which an inclined section and a flat section are provided on a wall and an end plate, and it is possible to avoid failure caused in a connecting section between the inclined section and the flat section.

[Solution to Problem]

In order to solve the aforementioned problems, a scroll fluid machine of the present invention is defined in claim 1.
That is, a scroll fluid machine according to an aspect of the present invention is a scroll fluid machine including: a first scroll member provided with a spiral first wall on a first end plate; and a second scroll member that is provided with a spiral second wall on a second end plate disposed so as to face the first end plate, and that relatively revolves by engagement between the second wall and the first wall, the scroll fluid machine including: an inclined section that continuously reduces an inter-facing-surface distance between the first end plate and the second end plate facing each other, from an outer circumferential side toward an inner circumferential side of each of the first wall and the second wall; wall flat sections provided in an outermost circumferential part and/or an innermost circumferential part of each of the first wall and the second wall, and having no change in height; and an end plate flat section provided in each of the first end plate and the second end plate, and corresponding to each of the wall flat sections, wherein each of the inclined sections is provided over a range of 180° or more around a spiral center and has an inclination angle of 0.2° or more and 4° or less, and a tooth tip of a wall inclined connecting section that connects the inclined section and each of the wall flat sections, and/or a tooth bottom of an end plate inclined connecting section that connects the inclined section and the end plate flat section has an inclination moderation shape formed by moderating and connecting an inclination extending from the flat section to the inclined section.
The inclined section that continuously reduces the inter-facing-surface distance between the first end plate and the second end plate from the outer circumferential side toward the inner circumferential side of each wall is provided, and therefore fluid sucked from the outer circumferential side is not only compressed by reduction of volume of compression chambers in accordance with the spiral shape of the wall, but also further compressed by reduction of the inter-facing-surface distance between the end plates, toward the inner circumferential side.
In the wall inclined connecting section that connects the inclined section and each of the wall flat sections, and/or the end plate inclined connecting section that connects the inclined section and the end plate flat section, if one tries to connect the flat section and the inclined section without any modification, the shape becomes a discontinuously changed portion, and machining becomes difficult, and therefore burrs or sagging are easily generated in the tooth tips or the tooth bottoms of these inclined connecting sections. When a burr or sagging is generated in the tooth tip or the tooth bottom, the shape deviates from a desired shape, and the inclined connecting section projects on the facing tooth bottom or tooth tip. Therefore, excessive contact may occur between the tooth tip and the tooth bottom.
To cope with the above, the tooth tip of the wall inclined connecting section and/or the tooth bottom of the end plate inclined connecting section has the inclination moderation shape formed by moderating and connecting the inclination extending from the flat section to the inclined section. Consequently, machining is facilitated by performing smooth connecting machining in the inclined connecting section, generation of a burr or sagging is suppressed, and it is possible to avoid excessive contact between the tooth tip and the tooth bottom.
An example of the "inclination moderation shape" includes a chamfered shape.
The scroll fluid machine according to an aspect of the present invention may include: a tip seal that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein a groove bottom inclined section corresponding to the inclined section of the wall, a groove bottom flat section corresponding to each of the wall flat sections, and a groove bottom inclined connecting section corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and the groove bottom inclined connecting section has an inclination moderation shape formed by moderating and connecting an inclination extending from the groove bottom flat section to the groove bottom inclined section.
In the groove bottom inclined connecting section, if one tries to connect the groove bottom flat section and the groove bottom inclined section without any modification, the shape becomes discontinuously changed, and machining becomes difficult, and therefore a burr or sagging is easily generated. When a burr or sagging is generated in the groove bottom, the tip seal is caught, and movement in accordance with turning movement is restricted, so that seal performance may not be able to be exhibited effectively.
In order to cope with the above, the groove bottom inclined connecting section has the inclination moderation shape formed by moderating and connecting the inclination extending from the groove bottom flat section to the groove bottom inclined section. Consequently, a smooth shape can be employed for the groove bottom inclined connecting section, catching of the tip seal is suppressed, and movement of the tip seal in accordance with the turning movement is allowed, so that it is possible to obtain desired seal performance.
An example of the "inclination moderation shape" includes a chamfered shape.
The scroll fluid machine according to an aspect of the present invention may include: a tip seal that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein a groove bottom inclined section corresponding to the inclined section of the wall, a groove bottom flat section corresponding to each of the wall flat sections, and a groove bottom inclined connecting section corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and a deep groove section located in a direction in which a groove becomes deeper than an extrapolation line of the groove bottom inclined section in longitudinal section view is provided in the groove bottom inclined connecting section.
The deep groove section located in the direction in which the groove becomes deeper than an extrapolation line of the groove bottom inclined section in longitudinal section view is provided in the groove bottom inclined connecting section. Consequently, the tip seal moves in and out of the deep groove section at the time of turning movement, so that it is possible to allow movement of the tip seal, and obtain desired seal performance.
The "longitudinal section view" means section view in a case of cutting by a cross-section along the center axis direction of a scroll member, and specifically means section view in a cross-section along the groove depth direction.
The scroll fluid machine according to an aspect of the present invention may include: a tip seal that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein a groove bottom inclined section corresponding to the inclined section of the wall, a groove bottom flat section corresponding to each of the wall flat sections, and a groove bottom inclined connecting section corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and the tip seal has a thickness at a position corresponding to the groove bottom inclined connecting section that is thinner than a thickness in another region.
The thickness of the tip seal at the position corresponding to the groove bottom inclined connecting section is thinner than the thickness in another region. Consequently, catching of the tip seal at the groove bottom inclined connecting section at the time of turning movement is suppressed, and movement of the tip seal in accordance with the turning movement is allowed, so that it is possible to obtain desired seal performance.

[Advantageous Effects of Invention]

It is possible to avoid excessive contact between the tooth tip and the tooth bottom in the inclined connecting section.
Further, movement of the tip seal in accordance with the turning movement in the groove bottom inclined connecting section is allowed, so that it is possible to obtain desired seal performance.

[Brief Description of Drawings]

[Fig. 1A] Fig. 1A is a longitudinal sectional view illustrating a fixed scroll and a turning scroll of a scroll compressor according to a first embodiment of the present invention.
[Fig. 1B] Fig. 1B is a plan view of the fixed scroll of Fig. 1A viewed from a wall side.
[Fig. 2] Fig. 2 is a perspective view illustrating the turning scroll of Fig. 1.
[Fig. 3] Fig. 3 is a plan view illustrating end plate flat sections provided in the fixed scroll.
[Fig. 4] Fig. 4 is a plan view illustrating a wall flat section provided in the fixed scroll.
[Fig. 5] Fig. 5 is a schematic diagram illustrating a wall represented so as to extend in the spiral direction.
[Fig. 6] Fig. 6 is a partially enlarged view illustrating an enlarged region of reference symbol Z in Fig. 1B.
[Fig. 7A] Fig. 7A is a side view illustrating a tip seal clearance of a portion illustrated in Fig. 6, and illustrating a state in which the tip seal clearance is relatively small.
[Fig. 7B] Fig. 7B is a side view illustrating the tip seal clearance of the portion illustrated in Fig. 6, and illustrating a state in which the tip seal clearance is relatively large.
[Fig. 8] Fig. 8 is a perspective view illustrating a circumference of a wall inclined connecting section.
[Fig. 9] Fig. 9 is a plan view of the fixed scroll, in which a position of the circumference of the wall inclined connecting section illustrated in Fig. 8 is indicated.
[Fig. 10] Fig. 10 is a longitudinal sectional view illustrating the circumference of the inclined connecting section illustrated in Fig. 8.
[Fig. 11] Fig. 11 is a longitudinal sectional view illustrating a circumference of an inclined connecting section of a comparative example, corresponding to Fig. 10.
[Fig. 12] Fig. 12 is a longitudinal sectional view illustrating a circumference of an inclined connecting section according to a second embodiment of the present invention.
[Fig. 13] Fig. 13 is a longitudinal sectional view illustrating a circumference of a groove bottom inclined connecting section according to a third embodiment of the present invention.
[Fig. 14] Fig. 14 is a longitudinal sectional view illustrating a circumference of a groove bottom inclined connecting section according to a fourth embodiment of the present invention.
[Fig. 15A] Fig. 15A is a longitudinal sectional view illustrating a modified example, and illustrating combination of scrolls having no step section.
[Fig. 15B] Fig. 15B is a longitudinal sectional view illustrating a modified example, and illustrating combination of stepped scrolls.

[Description of Embodiments]

[First Embodiment]

Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings.
Fig. 1 illustrates a fixed scroll (first scroll member) 3 and a turning scroll (second scroll member) 5 of a scroll compressor (scroll fluid machine) 1. The scroll compressor 1 is used as a compressor that compresses a gas refrigerant (fluid) for performing refrigerating cycle of an air conditioner or the like, for example.
The fixed scroll 3 and the turning scroll 5 are a compression mechanism made of metal such as aluminum alloy and iron, and are housed in a housing (not illustrated). The fixed scroll 3 and the turning scroll 5 suck, from the outer circumferential side, fluid guided into the housing, and discharge the compressed fluid from a discharge port 3c at the center of the fixed scroll 3 to the outside.
The fixed scroll 3 is fixed to the housing, and includes a substantially disk-shaped end plate (first end plate) 3a, and a spiral wall (first wall) 3b erected on a side surface of the end plate 3a, as illustrated in Fig. 1A. The turning scroll 5 includes a substantially disk-shaped end plate (second end plate) 5a, and a spiral wall (second wall) 5b erected on a side surface of the end plate 5a. The respective spiral shapes of the walls 3b, 5b are each defined by using, for example, an involute curve or an Archimedes curve.
The center of the fixed scroll 3 and the center of the turning scroll 5 are separated by a turning radius ρ, are engaged such that the phases of the walls 3b, 5b are shifted by 180°, and are assembled so as to have slight clearances (tip clearances) in the height direction between tooth tips and tooth bottoms of the walls 3b, 5b of both the scrolls at normal temperature. Consequently, a plurality of pairs of compression chambers formed so as to be surrounded by the end plates 3a, 5a and the walls 3b, 5b are formed between the scrolls 3, 5 so as to be symmetrical with respect to the scroll centers. The turning scroll 5 revolves around the fixed scroll 3 by a rotation prevention mechanism such as an Oldham ring (not illustrated).
As illustrated in Fig. 1A, inclined sections that continuously reduce an inter-facing-surface distance L between the facing end plates 3a, 5a from the outer circumferential sides toward the inner circumferential sides of the spiral walls 3b, 5b are provided.
As illustrated in Fig. 2, a wall inclined section 5b1 having a height that continuously reduces from the outer circumferential side toward inner circumferential side is provided in the wall 5b of the turning scroll 5. An end plate inclined section 3a1 (see Fig. 1A) that inclines in accordance with inclination of the wall inclined section 5b1 is provided in a tooth bottom surface of the fixed scroll 3 facing a tooth tip of this wall inclined section 5b1. The continuous inclined section is formed by these wall inclined section 5b1 and end plate inclined section 3a1. Similarly, a wall inclined section 3b1 having a height that continuously reduces from the outer circumferential side toward inner circumferential side is provided in the wall 3b of the fixed scroll 3, and an end plate inclined section 5a1 facing a tooth tip of this wall inclined section 3b1 is provided in the end plate 5a of the turning scroll 5.
The meaning of "continuously" in the inclined section mentioned in this embodiment is not limited to smoothly connected inclination, but includes inclination that is formed by stepwisely connecting small steps inevitably generated in machining, and that is an inclined section continuously inclined as a whole. However, the above meaning does not include a large step such as a so-called stepped scroll.
The wall inclined sections 3b1, 5b1 and/or the end plate inclined sections 3a1, 5a1 are coated. Examples of the coating include manganese phosphate treatment, and nickel-phosphorus plating.
As illustrated in Fig. 2, wall flat sections 5b2, 5b3 each having a constant height are provided on the innermost circumferential side and the outermost circumferential side of the wall 5b of the turning scroll 5, respectively. These wall flat sections 5b2, 5b3 are each provided over a region of 180° around the center 02 (see Fig. 1A) of the turning scroll 5. Wall inclined connecting sections 5b4, 5b5 serving as bent sections are provided at respective positions where the wall flat sections 5b2, 5b3 and the wall inclined section 5b1 are connected.
Similarly, end plate flat sections 5a2, 5a3 each having a constant height are provided on a tooth bottom of the end plate 5a of the turning scroll 5. These end plate flat sections 5a2, 5a3 are also each provided over a region of 180° around the center of the turning scroll 5. End plate inclined connecting sections 5a4, 5a5 serving as bent sections are provided at respective positions where the end plate flat sections 5a2, 5a3 and the end plate inclined section 5a1 are connected.
As illustrated by hatching in Fig. 3 and Fig. 4, end plate flat sections 3a2, 3a3, wall flat sections 3b2, 3b3, end plate inclined connecting sections 3a4, 3a5, and wall inclined connecting sections 3b4, 3b5 are provided in the fixed scroll 3, like the turning scroll 5.
Fig. 5 illustrates the walls 3b, 5b represented so as to extend in the spiral direction. As illustrated in Fig. 5, the wall flat sections 3b2, 5b2 on the innermost circumferential sides are each provided so as to extend over a distance D2, and the wall flat sections 3b3, 5b3 on the outermost circumferential sides are each provided so as to extend over a distance D3. The distance D2 and the distance D3 are equivalent to the lengths of the regions of 180° (180° or more and 360° or less, preferably 210° or less) around the centers 01, 02 of the scrolls 3, 5. The wall inclined sections 3b1, 5b1 are provided between the wall flat sections 3b2, 5b2 on the innermost circumferential sides and the wall flat sections 3b3, 5b3 on the outermost circumferential sides so as to extend over a distance D1. Where each of height differences between the wall flat sections 3b2, 5b2 on the innermost circumferential sides and the wall flat sections 3b3, 5b3 on the outermost circumferential sides is denoted by h, the inclination ϕ of each of the wall inclined sections 3b1, 5b1 is expressed by the following expression. $Φ = \tan^{- 1} (h / D 1)$
Thus, the inclination ϕ in the inclined section is constant with respect to the circumferential direction in which each of the spiral walls 3b, 5b extends. The distance D1 is longer than the distance D2, and is longer than the distance D3.
For example, in this embodiment, the specifications of the scrolls 3, 5 are as follows.

(1) Turning radius ρ [mm]: 2 or more and 15 or less, preferably 3 or more and 10 or less
(2) The number of turns of each of the walls 3b, 5b: 1.5 or more and 4.5 or less, preferably 2.0 or more and 3.5 or less
(3) Height difference h [mm]: 2 or more and 20 or less, preferably 5 or more and 15 or less
(4) h/Lout (wall height on outermost circumferential side): 0.05 or more and 0.35 or less, preferably 0.1 or more and 0.25 or less
(5) Angular range of inclined section (angular range equivalent to distance D1) [°]: 180 or more and 1080 or less, preferably 360 or more and 720 or less
(6) Angle Φ [°] of inclined section: 0.2 or more and 4 or less, preferably 0.5 or more and 2.5 or less

In Fig. 6, an enlarged view of a region indicated by reference symbol Z in Fig. 1B is illustrated. As illustrated in Fig. 6, a tip seal 7 is provided on the tooth tip of the wall 3b of the fixed scroll 3. The tip seal 7 is made of resin, and comes into contact with the tooth bottom of the end plate 5a of the facing turning scroll 5 to seal fluid. The tip seal 7 is housed in a tip seal groove 3d formed in the circumferential direction of the tooth tip of the wall 3b. Compressed fluid enters this tip seal groove 3d, and the tip seal 7 is pressed from a back surface, and pressed out to the tooth bottom side to be brought into contact with the facing tooth bottom. Similarly, a tip seal is provided on the tooth tip of the wall 5b of the turning scroll 5.
As illustrated in Fig. 7, the height Hc of the tip seal 7 in the height direction of the wall 3b is constant in the circumferential direction.
When both the scrolls 3, 5 relatively revolve, the respective positions of the tooth tip and the tooth bottom relatively shift by a turning diameter (turning radius ρ × 2). In the inclined section, a tip clearance between the tooth tip and the tooth bottom changes due to this position shift between the tooth tip and the tooth bottom. A tip clearance change amount Δh [mm] is, for example, 0.05 or more and 1.0 or less, preferably 0.1 or more and 0.6 or less. For example, the tip clearance T is small in Fig. 7A, and the tip clearance T is large in Fig. 7B. Even when this tip clearance T changes due to the turning movement, the tip seal 7 is pressed to the tooth bottom side of the end plate 5a from the back surface by compressed fluid, and therefore can seal following this pressing.
Fig. 8 is a perspective view illustrating a circumference of the wall inclined connecting section. This wall inclined connecting section is the wall inclined connecting section 3b4 on the inner circumferential side of the fixed scroll 3, as illustrated by reference symbol Z1 in Fig. 9.
In Fig. 8, the left side is the inner circumferential side of the wall 3b, and the right side is the outer circumferential side of the wall 3b. Therefore, the inner circumferential side of the wall inclined connecting section 3b4 (left side in Fig. 8) is the wall flat section 3b2, and the outer circumferential side of the wall inclined connecting section 3b4 (right side in Fig. 8) is the wall inclined section 3b1.
The tip seal 7 is inserted into the tip seal groove 3d formed in the tooth tip of the wall 3b. Fig. 8 illustrates a state in which compressed fluid enters the back surface side of the tip seal 7, and protrudes on the facing tooth bottom side (upper side in Fig. 8).
In Fig. 10, a longitudinal cross-section of the circumference of the wall inclined connecting section 3b4 illustrated in Fig. 8 is illustrated. In Fig. 10, a lower solid line illustrates the tooth tip of the wall 3b of the fixed scroll 3, and an upper solid line illustrates the tooth bottom of the end plate 5a of the turning scroll 5. That is, Fig. 10 illustrates a state in which the tooth tip and the tooth bottom face. In Fig. 10, the left side is the outer circumferential side of each of the scrolls 3, 5, and the right side is the inner circumferential side of each of the scrolls 3, 5.
As illustrated in Fig. 10, the wall inclined connecting section 3b4 between the wall flat section 3b2 and the wall inclined section 3b1 of the fixed scroll 3 has an R-chamfered shape. This R-chamfered shape is an inclination moderation shape formed by moderating and connecting an inclination extending from the wall flat section 3b2 to the wall inclined section 3b1. That is, a surface having the R-chamfered shape is located on the upper side in the height direction of the wall 3b with respect to an extrapolation line OL1 of the wall flat section 3b2 and an extrapolation line OL2 of the wall inclined section 3b1.
The end plate inclined connecting section 5a4 between the end plate flat section 5a2 and the end plate inclined section 5a1 of the turning scroll 5 has an R-chamfered shape. This R-chamfered shape is an inclination moderation shape formed by moderating and connecting an inclination extending from the end plate flat section 5a2 to the end plate inclined section 5a1. That is, this R-chamfered shape is an inclination moderation shape formed by moderating and connecting an inclination extending from the end plate flat section 5a2 to the end plate inclined section 5a1. That is, a surface having the R-chamfered shape is located in the direction in which the thickness of the end plate 5a reduces with respect to an extrapolation line OL3 of the end plate flat section 5a2 and an extrapolation line OL4 of the end plate inclined section 5a1 (direction in which the end plate 5a is dug).
Although not illustrated, the inclined connecting sections 3a4, 5b4 on the other inner circumferential sides each have a similar R-chamfered shape. Further, a similar R-chamfered shape may be employed in each of the inclined connecting sections 3b5, 5a5, 3a5, 5b5 on the outer circumferential sides.
In a groove bottom 10 (see Fig. 8) of the tip seal groove 3d, a groove bottom inclined connecting section corresponding to the wall inclined connecting section 3b4 has an R-chamfered shape similar to the R-chamfered shape of the tooth tip of the wall 3b.
The aforementioned scroll compressor 1 is operated as follows.
The turning scroll 5 revolves around the fixed scroll 3 by a driving source such as an electric motor (not illustrated). Consequently, fluid is sucked from the outer circumferential sides of the scrolls 3, 5, and is taken in the compression chambers surrounded by the walls 3b, 5b and the end plates 3a, 5a. The fluid in the compression chambers is sequentially compressed in accordance with movement from the outer circumferential side to the inner circumferential side, and the compressed fluid is finally discharged from the discharge port 3c formed in the fixed scroll 3. When the fluid is compressed, the fluid is compressed also in the height direction of the walls 3b, 5b in the inclined sections formed by the end plate inclined sections 3a1, 5a1 and the wall inclined sections 3b1, 5b1, and is three-dimensionally compressed.
According to this embodiment, the following working effects are exhibited.
As illustrated in Fig. 10, the R-chamfered shape is employed in each of the inclined connecting sections 3b4, 5a4. The working effects according to the above are as follows.
As a comparative example, a shape formed by cutting by an end mill without employing the R-chamfered shape is illustrated in Fig. 11. As illustrated in Fig. 11, when a machining instruction to connect a wall flat section 3b2 and a wall inclined section 3b1 without any modification, and perform machining along the extrapolation line OL1 of the wall flat section 3b2 and the extrapolation line OL2 of the wall inclined section 3b1 is given to an NC (Numerically Control) machine tool, sagging B1 is generated on a wall inclined connecting section 3b4, and a burr B2 is generated on an end plate inclined connecting section 5a4. That is, if one tries to connect the wall flat section 3b2 and the wall inclined section 3b1 without any modification, the wall inclined connecting section 3b4 becomes a portion in which the inclination suddenly changes, that is, a portion having a discontinuously changed shape. Thus, the portion having a discontinuously changed shape is difficult to be automatically machined by the NC machine tool, and therefore the sagging B1 that protrudes on the tooth bottom side of the turning scroll 5 is generated, as illustrated in Fig. 11.
Similarly, the end plate inclined connecting section 5a4 provided between an end plate flat section 5a2 and an end plate inclined section 5a1 is difficult to be machined, and therefore a burr B2 that protrudes on a tooth tip side of a fixed scroll 3 is generated. When such sagging B1 and burr B2 are generated, excessive contact is generated between the tooth tip and the tooth bottom in the inclined connecting sections 3b4, 5a4.
In this embodiment, the R-chamfered shapes are provided in the tooth tips of the wall inclined connecting sections 3b4, 3b5, 5b4, 5b5, and the tooth bottoms of the end plate inclined connecting sections 3a4, 3a5, 5a4, 5a5. Consequently, machining is facilitated by performing smooth connecting machining in the inclined connecting sections, generation of the burrs B2 or the sagging B1 is suppressed, and it is possible to avoid excessive contact between the tooth tips and the tooth bottoms.
Also in the groove bottom 10 of the tip seal groove 3d, if one tries to connect a groove bottom flat section and a groove bottom inclined section without any modification, the shape discontinuously changes, and machining becomes difficult, and therefore a burr or sagging is easily generated. When a burr or sagging is generated in the groove bottom 10, the tip seal 7 is caught, and movement in accordance with turning movement is restricted, so that seal performance may not be able to be exhibited effectively.
In this embodiment, like each tooth tip, the groove bottom inclined connecting section has the R-chamfered shape, and has the inclination moderation shape. Consequently, a smooth shape can be employed for the groove bottom inclined connecting section, catching of the tip seal 7 is suppressed, and movement of the tip seal 7 in accordance with the turning movement is allowed, so that it is possible to obtain desired seal performance.
In place of the R-chamfered shape used as the inclination moderation shape, a C-chamfered shape may be employed. Alternatively, a shape formed by changing an inclination stepwise so as to moderate a discontinuous inclination, and connecting the inclination may be employed.
The inclination moderation shape may be used for the inclined connecting section on one of the wall side and the end plate side.
The inclination moderation shape may be formed only on the inner circumferential side in which fluid pressure in the compression chambers is high, and may not be formed on the outer circumferential side in which fluid pressure in the compression chambers is relatively low.

[Second Embodiment]

Now, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in a shape in each inclined connecting section. Therefore, in the following, only portions different from the portions in the first embodiment will be described, and description of other common configurations will be omitted.
As illustrated in Fig. 12, in a wall inclined connecting section 3b4, a retreat section located in the retreating direction from a tooth bottom of a facing end plate 5a (lower side in Fig. 12) with respect to an extrapolation line OL1 of a wall flat section 3b2 and an extrapolation line OL2 of a wall inclined section 3b1 is provided. This retreat section is dug in the root direction of a wall 3b, and has a shape projecting downward.
An end plate inclined connecting section 5a4 has an R-chamfered shape like the first embodiment.
A retreat section located in the retreating direction from a facing tooth bottom is provided in each of other wall inclined connecting sections 3b5, 5b4, 5b5.
Thus, according to this embodiment, the retreat section is provided in the wall inclined connecting section 3b4, so that it is possible to increase a tip clearance that is a clearance between the tooth tip and the tooth bottom. Consequently, it is possible to reduce a possibility of contact between the tooth tip and the tooth bottom in the inclined connecting section.
The end plate inclined connecting section 5a4 has the R-chamfered shape in this embodiment, but may be provided with a retreat section having a shape projecting upward in Fig. 12 by further digging in the thickness direction of an end plate 5a. In this case, the retreat section provided in the facing wall inclined connecting section 3b4 may be omitted.
The retreat section may be formed only on the inner circumferential side in which fluid pressure in compression chambers is high, and may not be formed on the outer circumferential side in which fluid pressure in compression chambers is relatively low.

[Third Embodiment]

Now, a third embodiment of the present invention will be described. In this embodiment, a shape of a groove bottom of a tip seal groove 3d is different from that in the first embodiment. Therefore, in the following, only portions different from the portions in the first embodiment will be described, and description of configurations similar to the configurations in the first embodiment will be omitted. This embodiment can be combined with the aforementioned second embodiment.
As illustrated in Fig. 13, in a groove bottom 10 of the tip seal groove 3d, a groove bottom inclined section 10a corresponding to an inclined section 3b1 of a wall 3b, a groove bottom flat section 10b corresponding to a wall flat section 3b2, and a groove bottom inclined connecting section 10c corresponding to a wall inclined connecting section 3b4 are formed. A deep groove section 10d located in the direction in which the groove is deeper than an extrapolation line OL5 of the groove bottom inclined section 10a, that is, in the direction in which the groove is dug is provided in the groove bottom inclined connecting section 10c. The deep groove section 10d has a smooth shape formed by combination of curved surfaces.
This deep groove section 10d is provided also in the groove bottom inclined connecting section 10c corresponding to each of other wall inclined connecting sections 3b5, 5b4, 5b5.
According to this embodiment, the deep groove section 10d is provided, so that a tip seal 7 can move in and out of the deep groove section 10d at the time of turning movement. In Fig. 13, a shape in which the tip seal 7 enters the deep groove section 10d is illustrated by a two-dot chain line. Thus, it is possible to allow movement of the tip seal 7 in the circumferential direction to follow the turning movement, and desired seal performance can be obtained by the tip seal 7.
The deep groove section 10d may be formed only on the inner circumferential side in which fluid pressure in the compression chambers is high, and may not be formed on the outer circumferential side in which the fluid pressure in the compression chambers is relatively low.

[Fourth Embodiment]

Now, a fourth embodiment of the present invention will be described. This embodiment is characterized by the shape of a tip seal 7. Other configurations are similar to the configuration of the first embodiment, and therefore the description thereof will be omitted. This embodiment can be combined with each of the aforementioned first to the third embodiment.
As illustrated in Fig. 14, a groove bottom inclined section 10a corresponding to an inclined section 3b1 of a wall 3b, a groove bottom flat section 10b corresponding to a wall flat section 3b2, and a groove bottom inclined connecting section 10c corresponding to a wall inclined connecting section 3b4 are formed in a groove bottom 10 of a tip seal groove 3d. The tip seal 7 has a thickness t1 at a position corresponding to a groove bottom inclined connecting section 10c that is thinner than the thicknesses in other regions.
The shape formed by thinning the tip seal 7 at the position corresponding to the groove bottom inclined connecting section 10c is formed in a groove bottom inclined connecting section 10c corresponding to each of other wall inclined connecting sections 3b5, 5b4, 5b5.
According to this embodiment, the tip seal 7 has the thickness t1 at the position corresponding to the groove bottom inclined connecting section 10c which is thinner than the thicknesses in other regions, and therefore the tip seal 7 can move on the groove bottom inclined connecting section 10c side (see a two-dot chain line in Fig. 14). Consequently, it is possible to suppress catching of the tip seal 7 at the groove bottom inclined connecting section 10c at the time of turning movement to allow movement of the tip seal 7 in accordance with the turning movement, so that it is possible to obtain desired seal performance.
The shape formed by thinning the tip seal 7 may be formed only on the inner circumferential side in which fluid pressure in compression chambers is high, and may not be formed on the outer circumferential side in which fluid pressure in compression chambers is relatively low.
The end plate inclined sections 3a1, 5a1 and the wall inclined sections 3b1, 5b1 are provided in both the scrolls 3, 5 in each of the aforementioned embodiments, but may be provided in either one.
Specifically, as illustrated in Fig. 15A, in a case where a wall inclined section 5b1 is provided in a first wall (for example, a turning scroll 5), and an end plate inclined section 3a1 is provided in a second end plate 3a, a second wall and a first end plate 5a may be flat.
As illustrated in Fig. 15B, a shape formed by combination with a conventional stepped shape, that is, a shape, in which while an end plate inclined section 3a1 is provided in an end plate 3a of a fixed scroll 3, a step section is provided in an end plate 5a of a turning scroll 5, may be combined.
The present invention is applied to a scroll compressor in the aforementioned embodiments, but can be also applied to a scroll expander used as an expander.

[Reference Signs List]

1 scroll compressor (scroll fluid machine)
3 fixed scroll (first scroll member)
3a end plate (first end plate)
3a1 end plate inclined section
3a2 end plate flat section (inner circumferential side)
3a3 end plate flat section (outer circumferential side)
3a4 end plate inclined connecting section (inner circumferential side)
3a5 end plate inclined connecting section (outer circumferential side)
3b wall (first wall)
3b1 wall inclined section
3b2 wall flat section (inner circumferential side)
3b3 wall flat section (outer circumferential side)
3b4 wall inclined connecting section (inner circumferential side)
3b5 wall inclined connecting section (outer circumferential side)
3c discharge port
3d tip seal groove
5 turning scroll (second scroll member)
5a end plate (second end plate)
5a1 end plate inclined section
5a2 end plate flat section (inner circumferential side)
5a3 end plate flat section (outer circumferential side)
5a4 end plate inclined connecting section (inner circumferential side)
5a5 end plate inclined connecting section (outer circumferential side)
5b wall (second wall)
5b1 wall inclined section
5b2 wall flat section (inner circumferential side)
5b3 wall flat section (outer circumferential side)
5b4 wall inclined connecting section (inner circumferential side)
5b5 wall inclined connecting section (outer circumferential side)
7 tip seal
10 groove bottom
10a groove bottom inclined section
10b groove bottom flat section
10c groove bottom inclined connecting section
10d deep groove section
B1 sagging
B2 burr
Hc height of tip seal
L inter-facing-surface distance
T tip clearance
t1 thickness of tip seal
ϕ inclination

Claims

A scroll fluid machine (1) comprising:
a first scroll member (3) provided with a spiral first wall on a first end plate (3a); and

a second scroll member (5) that is provided with a spiral second wall on a second end plate (5a) disposed so as to face the first end plate, and that relatively revolves by engagement between the second wall and the first wall, the scroll fluid machine comprising:
an inclined section (3a1, 5a1) that continuously reduces an inter-facing-surface distance between the first end plate (3a) and the second end plate (5a) facing each other, from an outer circumferential side toward an inner circumferential side of each of the first wall and the second wall;

characterised in that it further comprises a wall flat section (3b2, 3b3, 5b2, 5b3) provided in an outermost circumferential part and/or an innermost circumferential part of each of the first wall and the second wall, and having no change in height; and

an end plate flat section (3a2, 3a3, 5a2, 5a3) provided in each of the first end plate and the second end plate, and corresponding to the wall flat section, wherein

each of the inclined sections (3a1, 5a1) is provided over a range of 180° or more around a spiral center and has an inclination angle of 0.2° or more and 4° or less, and

a tooth tip of a wall inclined connecting section (3b4, 3b5) that connects the inclined section and the wall flat section, and/or a tooth bottom of an end plate inclined connecting section (3a4, 3a5) that connects the inclined section and the end plate flat section has an inclination moderation shape formed by moderating and connecting an inclination extending from the flat section to the inclined section.
The scroll fluid machine (1) according to claim 1, further comprising:
a tip seal (7) that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein

a groove bottom inclined section (10a) corresponding to the inclined section of the wall, a groove bottom flat section (10b) corresponding to the wall flat section, and a groove bottom inclined connecting section (10c) corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and

the groove bottom inclined connecting section has an inclination moderation shape formed by moderating and connecting an inclination extending from the groove bottom flat section to the groove bottom inclined section.
The scroll fluid machine (1) according to claim 1, further comprising:
a tip seal (7) that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein

a groove bottom inclined section (10a) corresponding to the inclined section of the wall, a groove bottom flat section (10b) corresponding to the wall flat section, and a groove bottom inclined connecting section (10c) corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and

a deep groove section (10d) located in a direction in which a groove becomes deeper than an extrapolation line of the groove bottom inclined section in longitudinal section view is provided in the groove bottom inclined connecting section.
The scroll fluid machine (1) according to claim 1, further comprising:
a tip seal (7) that is provided in a groove section formed in a tooth tip of each of the first wall and the second wall, and that comes into contact with a facing tooth bottom to seal fluid, wherein

a groove bottom inclined section (10a) corresponding to the inclined section of the wall, a groove bottom flat section (10b) corresponding to the wall flat section, and a groove bottom inclined connecting section (10c) corresponding to the wall inclined connecting section are formed in a groove bottom of the groove section formed in the tooth tip, and

the tip seal (7) has a thickness at a position corresponding to the groove bottom inclined connecting section that is thinner than a thickness in another region.