JPH06101665A - Scroll fluid machine - Google Patents

Abstract

PURPOSE:To provide a scroll fluid machine having no possibility to increase noises and abrasion due to the contact at a circular arc portion, rarely reducing the sealing property, and having high reliability. CONSTITUTION:The cutting-off quantity 1j of the outer circular arc of a driven scroll spiral projection or the inner circular arc 1e of a driving scroll spiral projection 1a is given as the function of the spiral projection shape data and the radial gap to avoid the contact at the circular arc portions. The outer circular arc radius of the driving scroll spiral projection is made larger than the outer circular arc radius of the driven scroll spiral projection. Both scroll spiral projection shapes are made the same to avoid the contact at the circular arc portions, and centers of the outer circular arc and the inner circular arc of respective spiral projections are arranged on the basic circle of the involute curve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll fluid machine used for compressors, vacuum pumps and the like.

[0002]

2. Description of the Related Art The principle of a scroll fluid machine has been known for a long time and is a kind of positive displacement fluid machine which combines a pair of spiral projections to perform a compression action. Normally, one of the spiral protrusions is fixed and the other is swung to perform the compression action, but the principle of the so-called full system rotation type in which both spiral protrusions are rotated around their respective centers Patent No.
No. 3,884,599. Further, in a full-system rotary scroll fluid machine, a drive system that transmits a rotational force by bringing the scroll protrusion of one scroll into contact with the scroll protrusion of the other scroll is disclosed in U.S. Pat. It is described in.

This conventional full-system rotary scroll fluid machine is shown in FIGS. 11 and 12. In the figure, 1 is an electric motor,
A drive scroll (not shown) such as an engine or a turbine is a drive scroll that rotates about its axial center (spiral center) O ₁ and has a spiral protrusion 1a. Denoted at 2 is a driven scroll which is rotated around an axis center (spiral center) O ₂ in synchronism with the rotation of the driving scroll 1.
a. Both spiral projections 1a and 2a are formed by an involute curve. 3 is both scrolls 1, 2
The compression chamber for reducing the volume toward the center side and increasing the pressure of the compressed gas by the rotation of 4 is the first frame for supporting the driving scroll 1, 5 is the shaft for supporting the driven scroll, and 6 is for supporting this shaft. The second frame member 7 is a gas discharge port provided at the center of the driven scroll 2.

In the device constructed as described above,
The drive scroll 1 is rotated by the drive source in the direction of arrow 11 about the center O ₁ of the spiral. Then, the drive scroll spiral protrusion 1a contacts the driven scroll spiral protrusion 2a, and the rotational force is transmitted from the drive scroll 1 to the driven scroll 2. Therefore, the driven scroll 2 also rotates about the spiral center O ₂ in synchronization with the rotation of the drive scroll 1. Accordingly, the volume of the compression chamber 3 is reduced by the rotation of the compression chamber 3 toward the center, the pressure of the gas is increased, and the gas is discharged from the discharge port 7. In the state of 0 ° in FIG. 12A, gas is sucked into the compression chamber 3,
After that, as shown in (b) to (d), 0 ° → 90 ° → 180 ° → 2
Due to the rotation of 70 ° → 360 ° (0 °), the compression chamber 3 gradually moves to the center side and the volume decreases.

In the above operation, the situation when power is transmitted from the driving scroll to the driven scroll will be described in detail with reference to FIG. FIG. 13 shows that both scroll spiral protrusions 1a,
2a shows a state in which they are combined in a radial direction with no clearance. In the figure, 1b and 2b are outer involute curves 1c and 2c of the spiral protrusions 1a and 2a, respectively.
Is the inward curve of the spiral protrusions 1a and 2a, 1f and 2f are the basic circles of the involute curve, and a is the basic circle 1
The radii of f and 2f, and t are the thicknesses of the spiral projections 1a and 2a (thickness of the involute curve portion). r is the distance between the (normal) spiral centers (distance between O _{1 and} O ₂ ) in this state, and is defined by the following equation. r = πa-t (1) I ₁ is the contact point (seal point) between the involute curves 1c and 2b, I
₂ is the contact point (seal point) between the involute curves 1b and 2c, the broken line
303 is a tangent line drawn from I ₁ to the basic circles 1f and 2f, a broken line
304 shows a tangent line drawn from I ₂ to the base circles 1f and 2f. F _n1 and F _t1 are normal force and tangential force (friction force) acting on the driven scroll spiral projection 2a at the contact point I ₁ , and F _n2 and F _t2 are driven scroll spiral projection 2a at the contact point I ₂ . Is a normal force and a tangential force (friction force) acting on. Here, F _n1 acts in the direction of the tangent line 303 and F _n2 acts in the direction of the tangent line 304 due to the geometrical relationship of the involute curve. As is clear from the figure, F _n1 and F _t1 act in the direction of driving the driven scroll, while F _n2 and F _t2 act in the direction of braking the driven scroll. Therefore, it is absolutely necessary to avoid contact between the outer involute curve 1b of the spiral projection 1a and the inner involute curve 2c of the spiral projection 2a.

In order to avoid contact between the outer involute curve 1b of the spiral projection 1a and the inner involute curve 2c of the spiral projection 2a, in JP-A-3-267503, the distance between spiral centers is expressed by the equation (1). It is proposed to make the distance shorter than the regular center-to-center spiral distance r. This conventional invention will be described with reference to FIG. FIG. 14A shows a case where the distance between the centers of spirals is shorter than r by a distance b. In this case, the radial clearances at the seal points I ₁ and I ₂ are all b. When the machine is driven in this state, the drive scroll 1 rotates in the direction of arrow 11 as shown in FIG. 14 (b), and a difference in rotation angle occurs between the scrolls 1 and 2, and the spiral projections come into contact with each other. .
At this time, the spiral projections contact each other at the sealing point I ₁ between the involute curves 1c and 2b as shown in the figure, and the involute curve 1b
The size of the clearance at the seal point I ₂ between 2 and 2c is (2 * b)
Becomes

As described above, if the distance between the centers of the spirals is set shorter than the regular distance r between the centers of the spirals, there is no contact at the seal point I2, so that the driven scroll 2 is not subject to the braking force. Absent. Here, the practical range of the distance b is substantially determined from the processing error of the spiral projections 1a and 2a. If the maximum values of the processing errors of the spiral protrusions 1a and 2a are η ₁ and η ₂ , respectively, the distance b should be b> η ₁ + η ₂ (2). In this case, the scrolls 1 and 2 always have a rotation angle difference, and the scrolls 1 and 2 come into contact with each other only at the seal point I ₁ . Since the size of the clearance at the seal point I ₂ is (2 * b), if b is set too large, the leakage will increase and the performance will deteriorate. Therefore, in an actual machine, b has a certain upper limit value, and this upper limit value is set to such an extent that the sealing performance is not deteriorated.

Further, in the conventional scroll fluid machine, in order to reduce the re-expansion volume, the spiral projection is formed by an arc which smoothly connects the innermost peripheral portion to the involute curve.
It is known from Japanese Patent Laid-Open No. 59-58187. In the scroll fluid machine having such a spiral protrusion shape, when a difference in rotation angle occurs between the driving scroll 1 and the driven scroll 2, the spiral protrusions 1a and 2a come into contact with each other in an arc portion, which increases noise and increases the spiral protrusion. There is a risk of abnormal wear on the body. For this reason, in Japanese Patent Laid-Open No. 3-267503, it has been proposed to cut out an arc portion that may come into contact. This conventional machine will be described with reference to FIGS. 15 and 16. FIG. 15 shows a state in which both scroll spiral projections 1a and 2a are combined in a state with no radial clearance and are in contact with each other at an arc portion and an involute curve portion. In FIG. 15, the spiral projection 1a is formed with an outer inward curve 1b and an inner involute curve 1c on the outer peripheral portion, and an inner arc smoothly connects to an outer arc 1d and an inner involute curve 1c that smoothly connect to the outer involute curve 1b. It is formed by the inner circular arc 1e. Similarly, the spiral protrusion 2a also has an outer peripheral portion formed by an outer involute curve 2b and an inner involute curve 2c, and an inner peripheral portion smoothly connected to an outer arc 2d and an inner involute curve 2c that smoothly connect to the outer involute curve 2b. It is formed by the connecting inner circular arc 2e. I ₁ and I ₂ are the contact points between the involute curves 1c and 2b (sealing points) and the contact points between the involute curves 1b and 2c (sealing points), G ₁ and G _{2 respectively.}
Are contact points (sealing points) between the arcs 1e and 2d and contact points (sealing points) between the arcs 1d and 2e, respectively.

Similar to FIG. 14A, FIG. 16A shows a case where the distance between the centers of spirals is shorter than r by a distance b. In this case, the radial clearances at the respective seal points I ₁ , I ₂ , G ₁ and G ₂ are all b. If you drive the machine in this state,
As shown in FIG. 16 (b), the drive scroll 1 rotates in the direction of the arrow 11, and a difference in rotation angle occurs between the scrolls 1 and 2 so that the spiral projections come into contact with each other. At this time, the spiral projections are in contact with each other at the contact point G ₁ between the arcs 1e and 2d as shown in the figure, but not in the involute curve portion. In this case, the radial clearance at each seal point is smaller than b for I ₁ , and I ₂ , G
_{At 2} , it becomes larger than b.

As described above, when a difference in rotation angle occurs between the scrolls 1 and 2, contact at the arc portion cannot be avoided.
If both scroll spiral projections 1a and 2a contact each other in an arc portion, noise may increase or a large load may be applied to the spiral projections 1a and 2a to increase wear. Therefore, in the specification of the conventional invention, it is described that a part of the inner arc 1e of the drive scroll spiral projection 1a or the outer arc 2d of the driven scroll spiral projection 2a is cut off so as not to contact with the arc part. .

[0011]

Although the conventional scroll fluid machine is constructed as described above, the cut amount of the arc portion is not specified. For this reason, when cutting the arc portion in advance, there is a possibility that the spiral projection portion may be damaged due to insufficient cut amount, or the cutting performance may be deteriorated by cutting more than necessary.

The present invention has been made in order to solve the above-mentioned problems, and there is no fear of increase in noise and wear due to contact at an arc portion, and there is almost no deterioration in sealing performance. The purpose is to obtain a high scroll fluid machine.

[0013]

A scroll fluid machine according to the present invention comprises a drive scroll and a driven scroll that rotate on mutually different axes and have spiral projections on a flat plate.
Both the driving scroll and the driven scroll work together to form a compression chamber, the outer peripheral portions of both spiral projections are formed with the same involute curve, and the inner peripheral portion forms the spiral projection body of the drive scroll on the outer involute curve. The outer arc with radius R ₁ that smoothly connects to the inner radius and the radius that smoothly connects to the inner involute curve (R ₂ +
r) is formed by the inner arc, and the spiral projection of the driven scroll is smoothly connected to the outer involute curve. The outer arc of radius R _{2 and} the radius to smoothly connect to the inner involute curve (R ₁ +
In the scroll fluid machine, which is formed by an inner circular arc of r), the distance between the center of spiral of both scrolls is shorter by b than the normal distance r of center of spiral where there is no clearance in the radial direction. Ε> -r + [r ² + 4e ₁ sin Ψ {e ₁ sin Ψ + rsin (ξ ₁ + φ + Ψ)}] of the spiral thickness of the outer circular arc part or the inner circular arc part of the driving scroll spiral protrusion
^0.5 -b ξ ₁ = tan ^-1 {a / (m + fcosγ)} (0 ≤ ξ ₁ ≤ π) a: Basic circle radius of the involute curve φ: Angle of the above arc measured from the contact point with the involute curve (however , R ₁ = R ₂ may be used).

Also, in a scroll fluid machine according to another invention of the present invention, the spiral thickness of the outer circular arc portion of the driven scroll spiral projection or the inner circular arc portion of the drive scroll spiral projection is expressed as ε> 2e ₁ sin Ψ-b. e ₁ = (m ² + 2mf cosγ + f ² ) ^0.5 m = (R ₁ -R ₂ ) / 2, f = (R ₁ + R ₂ + r) / 2 γ = sin ^-1 (a / f) (0 ≦ γ ≦ π / 2) Ψ = b / 2a (however, R ₁ = R ₂ may be used), and the thickness is uniformly thin.

Further, the outer arc radius of the drive scroll spiral projection is larger than the outer arc radius of the driven scroll spiral projection.

Further, a scroll fluid machine according to another invention of the present invention is provided with a drive scroll and a driven scroll which rotate on mutually different axes and have spiral projections provided on a flat plate.
Both the driving scroll and the driven scroll work together to form a compression chamber, both spiral projections have the same shape, and the outer circumference of each spiral projection is formed by an involute curve, and the inner circumference is outside. The outer arc with radius R that smoothly connects to the involute curve of and the radius (R that smoothly connects to the inner involute curve of R
+ R) is formed by the inner arc, and by forming the outer arc radius R of both scroll spiral projections by R = a−r / 2, the center of the outer arc and the inner arc is the basis of the involute curve. It is arranged on a circle.

[0017]

According to the present invention, even if there is a difference in rotation angle between the driving scroll and the driven scroll, the arc portion of the inner peripheral portion of the spiral projection is cut out in advance by a predetermined amount, so that the arc portion is always in contact. You can drive without. In addition, since the arcuate portion is cut out only in the required minimum amount, it can be expected that the sealing property is hardly deteriorated.

According to another aspect of the present invention, the inner arc of the drive scroll spiral projection or the outer arc of the driven scroll spiral projection may be machined with a predetermined radius in advance, which facilitates the machining. Become.

If the outer arc radius of the drive scroll spiral projection is made larger than the outer arc radius of the driven scroll spiral projection, the outer arc of the drive scroll spiral projection and the driven scroll spiral projection are added in addition to the above functions. Since the clearance between the inner circular arcs can be reduced, the sealing performance can be further improved.

Further, by arranging the centers of the outer arc and the inner arc on the basic circle of the involute curve, even if there is a difference in the rotation angle between the driving scroll and the driven scroll, in principle, the arc portion does not always come into contact with each other. You can drive to. Further, since the clearance between the outer arc of the drive scroll spiral projection and the inner arc of the driven scroll spiral projection can be minimized, the sealing performance can be further improved.

[0021]

【Example】

Example 1. An embodiment of the scroll fluid machine according to the invention of claim 1 will be described below with reference to FIGS. In this embodiment, the shapes of both scroll spiral projections are the same (that is, the radii R ₁ = R _{2 of} both scrolls). FIG. 1 shows the shape of the drive scroll spiral protrusion 1a. R is the radius of the outer arc 1d (2d) of the spiral protrusion 1a (2a), r
Is the normal center-to-center spiral distance shown in equation (1). Then, the inner circular arc 1e (2e) of the spiral protrusion 1a (2a)
Has a radius of R + r. A ₁ (A ₂ ) is the inner arc 1e (2
e) center, B ₁ (B ₂ ) is the center of the outer arc 1d (2d),
C ₁ (C ₂ ) is the inner arc 1e (2e) and the inner involute curve 1
The contact point of c (2c), D ₁ (D ₂ ) is the contact point of the outer arc 1d (2d) and the outer involute curve 1b (2b). e is O ₁
-A ₁ (O ₂ −A ₂ ) distance, which is O ₁ −B ₁ (O ₂ −
Equal to the distance between B ₂ ). γ is B ₁ (B ₂ ) and D ₁ (D ₂ )
The angle formed by the straight line 101 (straight line 201) connecting A and the straight line 103 (straight line 203) connecting A ₁ (A ₂ ) and B ₁ (B ₂ ) is E ₁ (E ₂ ) is A ₁
The contact point between the straight line 102 (straight line 202) connecting (A ₂ ) and C ₁ (C ₂ ) and the base circle 1f (2f), F ₁ (F ₂ ) is the straight line 101 (straight line ₂ )
This is the contact point between 01) and the base circle 1f (2f). e and γ
Are expressed by the following equations based on the geometrical relationship. e = R + r / 2 (3) γ = sin ⁻¹ (a / e) (0 ≦ γ ≦ π / 2) (4)

FIG. 2 (a) shows a state in which the spiral projections 1a, 2a of both scrolls 1, 2 are combined in a radial direction without any clearance, and φ is a straight line 201 (straight line 102) and A ₁ and B. It is the angle formed by the straight line 301 connecting the _two . FIG. 2B is an enlarged view showing a state in which only the drive scroll 1 is rotated by an angle ψ (rotation angle difference) from the state of FIG. 2A. Since there is no radial clearance, a rotational angle difference does not actually occur, but here it is considered that the drive scroll 1 has rotated ψ for the sake of convenience. In the drawing, an arc 1e indicated by a broken line is an inner arc of the drive scroll spiral projection 1a before rotation, and 1h is a drive scroll spiral projection 1 after rotation.
Inner arc of a, A ₁₀ is center of inner arc 1h, C ₁₀ is contact point C ₁
After rotation, β is ∠A ₁₀ A ₁ B ₂ , λ is ∠A ₁ B
₂ A ₁₀ and G ₁₁ are the intersections of the straight line 302 connecting A ₁₀ and B ₂ and the inner arc 1f, G ₁₂ is the intersection of the straight line 302 and the outer arc 2d, and φ ₁ is ∠
C ₁₀ A ₁₀ G ₁₂ , φ ₂ is ∠D ₂ B ₂ G ₁₂ , L is the distance between A _{10 and} B ₂ , d is the distance between A _{1 and} A ₁₀ , and ε ₀ is between G _{11 and} G ₁₂ . It is a distance. As is apparent from the figure, the inner arc 1h of the drive scroll spiral projection 1a and the outer arc 2d of the driven scroll spiral projection 2a interfere with each other. The maximum value of the amount of interference in the radial direction is ε _{0 due} to the geometrical relationship of the circle. Below, ε ₀ is obtained. From the figure, ε ₀ is ε ₀ = L−r (5), and L is expressed as L = (r ² + d ² −2 drcos β) ^0.5 (6). Further, d and β are respectively expressed as d = 2 esin (ψ / 2) (7) β = 1.5π-γ-φ-ψ / 2 (8). Further, λ, φ ₁ and φ ₂ are given as follows from the geometrical relation. λ = sin ^-1 (dsin β / L) (9) φ ₁ = φ + ψ-λ (10) φ ₂ = φ-λ (11) On the other hand, in the involute curve, the difference in rotation angle between the drive scroll 1 and the driven scroll 2 The interference amount ε ₁ corresponding to the interference amount ε ₀ in the above-mentioned arc portion when ψ occurs is obtained from FIG. In the figure, 1c is the inner involute curve of the driving scroll spiral protrusion 1a before rotation, and 1g is the driving scroll 1.
Is rotated ψ in the direction of arrow 11, the inner involute curve of the driven scroll spiral protrusion 1a after rotation, 2b is the outer involute curve of the driven scroll spiral protrusion 2a, and I1 is the contact portion (seal portion) before rotation. , H1 and H2 are the tangent line 303 and the base circles 1f and 2 drawn from I1 to the base circles 1f and 2f, respectively.
f is the contact point, H ₁₀ is the position of H ₁ after rotation, I ₁₀ is the tangent 303
And the inner involute curve 1g, ε ₁ is the distance between I _{1 and} I ₁₀ . From the geometrical characteristics of the involute curve, ε ₁ is the maximum radial interference amount. The distance between H _{1 and} I ₁ is aΦ
(Φ is the extension angle), ε ₁ is independent of the rotational position,
It can be easily calculated as follows. ε1 = aΦ-a (Φ−ψ) = aψ (12) Next, the condition that the circular arc portion is not brought into contact with the clearance b in the radial direction is calculated. When there is a clearance in the radial direction and the contact is always made at the involute portion, naturally ε ₁ = b.
Therefore, in order to always make contact at the involute portion, the arc portion may be cut off by ε shown by ε> ε ₀ -b (13). Hereinafter, ε will be expressed as a function of the spiral projection shape data and the radial clearance b. The rotation angle difference ψ can be obtained by setting ε ₁ = b in equation (12). ψ = b / a (14) Substituting ψ obtained from equation (12) into equations (7) and (8), equations (5) to (8)
By substituting equation (13) for equation (8), the following equation is obtained. ε> −r + [r ² +4 esin Ψ {esin Ψ + rsin (γ + φ + Ψ)}] ^0.5 −b (15) where Ψ = ψ / 2 = b / 2a. If the arc portion is cut off as shown in Expression (15), the operation can be performed without contact at the arc portion. However, in reality, if ε is made larger than necessary, the sealing property at the most important arc portion will be deteriorated. Therefore, it is desirable that ε be ε = -r + [r ² +4 esin Ψ {esin Ψ + rsin (γ + φ + Ψ)}] ^0.5 -b + δ (16) from the viewpoint of sealing property. Here, δ is a small amount. In equations (15) and (16), the actual b
The range of is given by equation (2). Further, b has an upper limit value such that the sealing property does not deteriorate.

In the equations (15) and (16), ε is expressed as a function of φ. Strictly speaking, in the portion of the inner circular arc 1e of the driving scroll spiral projection 1a, at the position of φ ₁ , the driven scroll is driven. In the portion of the outer circular arc 2d of the spiral projection 2a, it is necessary to cut out by ε at the position of φ ₂ . However, since the influence of the angle λ on ε is actually sufficiently small, it is almost okay to cut the portion of the inner arc 1e or the outer arc 2d by ε at the position of the angle φ.

FIG. 4 shows a portion of the inner circular arc 1e of the drive scroll spiral projection 1a cut out in accordance with the circular arc angle φ using the relationship of the equation (16). In the figure, the shaded portion 1j indicates a cutout portion. In FIG. 4, the inner arc 1e of the drive scroll spiral projection 1a is cut out, but as shown in FIG. 5, the outer arc 2d of the driven scroll spiral projection 2a is cut off.
The same effect can be obtained by similarly cutting out the part.

With the above construction, the scrolls 1 and 2 are always in contact with each other only by the involute curve portions 1c and 2b of the spiral projections 1a and 2a, and the arc portions 1e and 2d have a small clearance δ. It will be.

Example 2. An embodiment of the invention of claim 2 is shown in FIG. In this embodiment, the portion of the inner arc 1e of the drive scroll spiral protrusion 1a is evenly cut by the maximum value ε _{m of} ε. The maximum value ε _m of ε is given by the equation (16) as ε _m = 2esin Ψ−b + δ (17). In this case as well, the same effect can be obtained by similarly cutting out the outer arc 2d of the driven scroll spiral projection 2a.

With the above structure, the inner arc 1e of the drive scroll spiral projection 1a has a radius (R + r + ε _m ) or the outer arc 2d of the driven scroll spiral projection 2a has a radius (R-
Since processing with ε _m ) is sufficient, processing becomes easy.

Example 3. Next, another embodiment of the inventions of claims 1 and 2 will be described. In the present embodiment, as for the scroll fluid machine having different arc portion shapes for the driving scroll and the driven scroll, the cut amount of the arc portion is expressed by an equation as in the first and second embodiments. Scroll fluid machines having different arc shapes are known from Japanese Patent Laid-Open Nos. 3-11103 and 3-267503.

This embodiment will be described with reference to FIGS.
7 (a) and 7 (b) respectively show the spiral projection shapes of the driving scroll and the driven scroll. In FIG. 7, R1, R
Reference numerals 2 denote the radii of the outer arc 1d of the drive scroll spiral projection 1a and the outer arc 2d of the driven scroll spiral projection 2a, respectively. Then, the radii of the inner arc 1e of the drive scroll spiral projection 1a and the inner arc 2e of the driven scroll spiral projection 2a are R ₂ + r and R ₁ + r, respectively, due to the geometrical conditions. e ₁ and e ₂ are the distance between O ₁ -A ₁ (O ₂ -B ₂ ) and the distance between O ₂ -A ₂ (O ₁ -B ₁ ), respectively, and γ is the straight line 102.
The angle between (line 201) and line 103 (line 203), ξ ₁ ,
ξ ₂ is straight line 102 (straight line 201) and A ₁ and O ₁ (B ₂ and 0)
₂ ) and the angle formed by the straight line connecting 101 and straight line 101 (straight line 20
2) and the straight line connecting B ₁ and O ₁ (A ₂ and O ₂ ). When the difference between the distance between C _{1 and} E ₁ and the distance between D _{1 and} F ₁ is calculated, the following equation is obtained from the geometrical relationship of the involute curve. R ₂ −R ₁ −r + e ₁ cos ξ ₁ −e ₂ cos ξ ₂ = t−aπ (18) Here, t is the thickness of the incomplete curve portion of the spiral protrusions 1 a and 2 a. On the other hand, the following equation is obtained from the geometrical relation of the arc portion in FIG. e ₁ cosξ ₁ + e ₂ cosξ ₂ = (R ₁ + R ₂ + r) cosγ (19) e ₁ sinξ ₁ = e ₂ sinξ ₂ = a (20) From equation (18) and equation (19), The formula is obtained. e ₁ cos ξ ₁ = m + f cosγ (21) Here, m = (R ₁ −R ₂ ) / 2, f = (R ₁ +
R ₂ + r) / 2. From Equation (20) and Equation (21), e ₁ , ξ ₁
Are given as follows. e ₁ = (m ² + 2m fcosγ + f ² ) ^0.5 (22) ξ ₁ = tan ⁻¹ {a / (m + fcosγ} (0 ≦ ξ ≦ π) (23) Note that γ is γ = sin from the figure. ⁻¹ (a / f) (0 ≦ γ ≦ π / 2) (24).

Similar to FIG. 2A, FIG. 8A shows a state in which the spiral projections 1a and 2a of both scrolls 1 and 2 are combined in a radial direction without any clearance and are in contact with each other in an arc portion. Is. Similarly to FIG. 2B, FIG. 8B also shows a state in which only the drive scroll 1 is rotated by the angle ψ. As is clear from the figure, if there is a clearance b in the radial direction, the minimum arc cut-off amount ε to prevent contact at the arc portion is given by ξ1 in place of γ and e1 in place of e in equation (16). Desired. Then, the cut amount ε of the arc portion is expressed by the following equation. ε = -r + [r ² + 4e ₁ sin Ψ {e ₁ sin Ψ + rsin (ξ ₁ + φ + Ψ)}] ^0.5 -b + δ (25)

FIG. 9 shows a portion of the inner circular arc 1e of the drive scroll spiral projection 1a cut out in accordance with the circular arc angle φ using the relationship of the equation (25). In the figure, the shaded portion 1j indicates a cutout portion. Although the inner arc 1e of the drive scroll spiral projection 1a is cut out in FIG. 9, the same effect can be obtained by similarly cutting the outer arc 2d of the driven scroll spiral projection 2a.

With the above structure, the scrolls 1 and 2 are always in contact with each other only by the involute curve portions 1c and 2b of the spiral projections 1a and 2a, and the arc portions 1e and 2d have a small clearance δ. It will be.

Further, as in the second embodiment, in the above-described embodiment, the maximum value of ε _m of the inner arc 1e of the drive scroll spiral projection 1a or the outer arc 2d of the driven scroll spiral projection 2a is determined. However, it may be cut out uniformly (not shown). The maximum value ε _m of ε is given by the following equation from equation (25). ε _m = 2e ₁ sin Ψ-b + δ (26)

According to the above construction, the inner arc 1e of the drive scroll spiral projection 1a has a radius (R ₂ + r + ε _m ) or the outer arc 2d of the driven scroll spiral projection 2a has a radius (R ₂ ) in advance. -ε
_Since it only has to be processed in _m ), the processing becomes easier.

Example 4. Next, an embodiment of the scroll machine of claim 3 will be described. In this embodiment, the outer arc radius R1 of the drive scroll spiral projection is larger than the outer arc radius R2 of the driven scroll spiral projection in the third embodiment. For the sake of simplicity, a case will be described in which either the inner arc 1e of the drive scroll spiral projection 1a or the outer arc 2d of the driven scroll spiral projection 2a is cut out uniformly. In the third embodiment, the radial clearance between the inner arc 1e of the drive scroll spiral projection 1a and the outer arc of the driven scroll spiral projection 2a is certainly a small amount δ.
Kept in. However, the radial clearance between the outer circular arc 1d of the driving scroll spiral protrusion 1a and the inner circular arc 2e of the driven scroll spiral protrusion is larger than b.

When there is a clearance b in the radial direction, the size of the clearance at the sealing point G ₂ (see FIG. 8 (a)) between the outer arc 1d of the drive scroll spiral projection 1a and the inner arc 2e of the driven scroll spiral projection 1a. When the the epsilon ₂ of the maximum value epsilon _2m of epsilon ₂ removes δ in equation (24), -b instead of b, obtained by substituting e ₂ in place of e _1. ε _2m = 2e ₂ sin Ψ + b (27) Below, e ₂ is obtained. The following equation is obtained from the equations (18) and (19). e ₂ cos ξ ₂ = -m + f cosγ (28) From equations (28) and (20), e2 is given by the following equation. e ₂ = (m ² -2mf cosγ + f ² ) ^0.5 (29)

In this embodiment, the outer circular arc radius R1 of the driving scroll spiral projection 1a is the driven scroll spiral projection 2a.
Since it is configured to be larger than the outer arc radius R2 of
m> 0. Then, e ₂ becomes smaller than the expression (29), and as a result, the clearance ε _2m becomes smaller than the expression (27).

As described above, in this embodiment, since the clearance ε ₂ between the outer circular arc 1d of the drive scroll spiral projection 1a and the inner circular arc 2e of the driven scroll spiral projection can be reduced, the sealing performance is improved. You can

Example 5. An embodiment of the scroll fluid machine according to the invention of claim 4 will be described with reference to FIG. Figure 10
Although (a) shows the shape of the driving scroll spiral projection 1a, the shape of the driven scroll spiral projection 2a is also the same. In the figure, the inner arc center A ₁ (A ₂ ) and the outer arc center B ₁ (B ₂ ) are on the basic circle 1f (2f). Therefore, the angle γ formed by the straight line 101 (straight line 201) and the straight line 103 (straight line 203) is π / 2, and the distance between O ₁ −A ₁ (O ₂ −A ₂ ) or O ₁ −B ₁ (O ₂ The distance e between −B ₂ ) is equal to the base circle radius a.

As is apparent from the equations (3) and (4), the spiral protrusion shape as described above is e and the outer arc radius R.
Is the minimum shape. From the equation (3), R is R = a−r / 2 (30). The maximum value of the arc cut amount at this time ε _m
Can be obtained by substituting a for e in equation (17). ε _m = 2a (sin Ψ−Ψ) + δ (31) Since sin Ψ <Ψ, εm <δ (32). Therefore, in the spiral projection shape of the present embodiment, it is possible in principle to avoid contact at the arc portion. This eliminates the need for cutting
Processing becomes easy and reliability is improved. In addition, even when cutting out the arc portion in consideration of the processing error,
As shown in (b), the inner circular arc 1 of the drive scroll spiral protrusion 1a
It suffices to evenly cut out the portion e by a small amount δ, and processing becomes easy. In addition, in this embodiment,
It is clear from Equation (27) that the maximum value ε _2m of the clearance ε ₂ between the outer circular arc 1d of the driving scroll spiral protrusion 1a and the inner circular arc 2e of the driven scroll spiral protrusion is also minimum. Therefore, the sealing property is also significantly improved.

In each of the above-described embodiments, the drive system in which the rotating force is transmitted by bringing the spiral projections into contact with each other has been described, but the present invention can be applied to other full-system rotary scroll fluid machines. As a method of driving the scroll fluid machine of the entire system, there are a method using an old joint, a method using a pin joint, a method using a gear, and the like.
Regardless of which drive method is used, a slight difference in rotation angle always occurs between the two scrolls due to scroll processing errors and assembly errors. On the other hand, since the radial clearance b is naturally set to be small, there is a possibility that the spiral projections may come into contact with each other in some cases. In this case, if the circular arc portion of the spiral protrusion is not cut off, the spiral protrusion will always come into contact with the spiral protrusion, resulting in increased wear and noise of the spiral protrusion. Therefore, no matter which driving method is used, if the arcuate portion is cut out by the amount shown in the above-mentioned embodiment, even if the spiral projections are in contact with each other, the contact in the arcuate portion can be always avoided. The property is improved.

[0042]

As described above, according to the present invention, the spiral thickness of the outer circular arc portion of the driven scroll spiral projection or the inner circular arc portion of the drive scroll spiral projection is expressed as ε> -r + [r ² + 4e ₁ sin Ψ {e ₁ sin Ψ + rsin (ξ ₁ + φ + Ψ)}]
^0.5 -b ξ ₁ = tan ^-1 {a / (m + fcosγ)} (0 ≤ ξ ₁ ≤ π) a: Basic circle radius of the involute curve φ: Angle of the above arc measured from the contact point with the involute curve (however , R ₁ = R ₂ ), the cutting amount of the outer arc of the driven scroll spiral projection or the inner arc of the driving scroll spiral projection is equal to the spiral projection shape. It is given as a function of specifications and radial clearance, which allows the circular arc portion to be cut out to the minimum required amount, so the radial clearance during operation is always kept small, and there is no risk of contact in the circular arc portion. . Therefore, compared to the conventional case, the contact in the arc portion can be always avoided and the sealing property can be easily improved, so that it is possible to provide a scroll fluid machine with high performance and high reliability. Become.

According to another invention of the present invention, the spiral thickness of the outer circular arc portion of the driven scroll spiral projection or the inner circular arc portion of the drive scroll spiral projection is expressed as ε> 2e ₁ sin Ψ-b e ₁ = (m ² + 2mf cosγ + f ² ) ^0.5 m = (R ₁ −R ₂ ) / 2, f = (R ₁ + R ₂ + r) / 2 γ = sin ⁻¹ (a / f) (0 ≦ γ ≦ π / 2) Ψ = b / 2a (however, R ₁ = R ₂ may be used), and since it is formed uniformly thin by the amount of ε, processing is facilitated in addition to the above effect.

If the outer circular arc radius of the driving scroll spiral projection is made larger than the outer circular arc radius of the driven scroll spiral projection, the outer arc of the driving scroll spiral projection and the driven scroll spiral projection are added in addition to the above functions. Since the clearance between the inner circular arcs can be reduced, the sealing performance can be further improved.

Further, according to another invention of the present invention, both spiral projections have the same shape, the outer peripheral portion of each spiral projection is formed by an involute curve, and the inner peripheral portion is formed by an outer involute curve. It is formed by an outer circular arc with a radius R that smoothly connects to the inner circular arc and an inner circular arc with a radius (R + r) that smoothly connects to the inner involute curve. The outer circular arc radius R of both scroll spiral projections is R = a By forming with -r / 2, the centers of the outer arc and the inner arc are arranged on the basic circle of the involute curve, so that in principle, the shape of the spiral protrusion that does not contact at the arc portion is obtained, and by this, Since it is not necessary to cut out the arc portion and contact with the arc portion can be avoided, there is an effect that machining is facilitated and reliability is improved. Furthermore, since the clearance between the outer arc of the drive scroll spiral projection and the inner arc of the driven scroll spiral projection can be minimized, there is an effect that the sealing performance is significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a main part of a scroll spiral protrusion for explaining a first embodiment.

FIG. 2 is an explanatory diagram showing a main part of a scroll spiral protrusion for explaining the first embodiment.

FIG. 3 is an explanatory diagram for explaining the first embodiment.

FIG. 4 is an explanatory diagram showing an example of a shape of a main part of the drive scroll spiral protrusion according to the first embodiment.

FIG. 5 is an explanatory diagram showing another example of the shape of the main part of the drive scroll spiral protrusion according to the first embodiment.

FIG. 6 is an explanatory diagram showing an example of a shape of a main part of a drive scroll spiral protrusion according to a second embodiment.

FIG. 7 is an explanatory diagram showing a main part of a drive and driven scroll spiral projection for explaining a third embodiment.

FIG. 8 is an explanatory diagram showing a main part of a scroll spiral protrusion for explaining a third embodiment.

FIG. 9 is an explanatory diagram showing an example of a shape of a main part of a drive scroll spiral protrusion according to a third embodiment.

FIG. 10 is an explanatory diagram showing a main part of a scroll spiral protrusion for explaining a fifth embodiment.

FIG. 11 is a partial cross-sectional view showing a conventional full-system rotary scroll fluid machine.

FIG. 12 is an explanatory diagram explaining the operation of the one in FIG. 11;

FIG. 13 is an explanatory diagram illustrating a situation when power is transmitted from a driving scroll to a driven scroll.

FIG. 14 is a cross-sectional view of an essential part for explaining the operation principle of another conventional device.

FIG. 15 is an explanatory diagram showing a main part of still another conventional device.

16 is an explanatory diagram illustrating an operation of the conventional device shown in FIG.

[Explanation of symbols]

 1 Drive Scroll 1a Spiral Protrusion 1b Outer Involute Curve 1c Inner Involute Curve 1d Outer Arc 1e Inner Circular Arc 1j Cutout Part 2 Driven Scroll 2a Outer Involute Curve 2c Inner Involute Curve 2d Outer Arc 2e Inner Arc 2j Internal Arc 2j

Claims (4)

[Claims] 1. A drive scroll and a driven scroll, which rotate on mutually different axes and have spiral projections provided on a flat plate, both drive scroll and driven scroll working together to form a compression chamber. The outer circumferences of both spiral projections are formed with the same involute curve, and the inner circumference is formed with an outer arc of radius R ₁ and an inner involute curve that smoothly connect the spiral projections of the drive scroll to the outer involute curve. Radius for smooth connection (R
₂ + r) is formed by an inner arc and the spiral projection of the driven scroll is smoothly connected to the outer involute curve. The outer arc of radius R _{2 and} the radius to smoothly connect to the inner involute curve (R ₁ +
In the scroll fluid machine, which is formed by an inner circular arc of r), the distance between the center of spiral of both scrolls is shorter by b than the normal distance r of center of spiral where there is no clearance in the radial direction. Ε> -r + [r ² + 4e ₁ sin Ψ {e ₁ sin Ψ + rsin (ξ ₁ + φ + Ψ)}] of the spiral thickness of the outer circular arc part or the inner circular arc part of the driving scroll spiral protrusion
^0.5 -b ξ ₁ = tan ^-1 {a / (m + fcosγ)} (0 ≤ ξ ₁ ≤ π) a: Basic circle radius of the involute curve φ: Angle of the above arc measured from the contact point with the involute curve (however , R ₁ may be R ₂ ). 2. A drive scroll and a driven scroll, which rotate on mutually different axes and have spiral projections provided on a flat plate, both drive scroll and driven scroll working together to form a compression chamber. The outer circumferences of both spiral projections are formed with the same involute curve, and the inner circumference is formed with an outer arc of radius R ₁ and an inner involute curve that smoothly connect the spiral projections of the drive scroll to the outer involute curve. Radius for smooth connection (R
₂ + r) is formed by an inner arc and the spiral projection of the driven scroll is smoothly connected to the outer involute curve. The outer arc of radius R _{2 and} the radius to smoothly connect to the inner involute curve (R ₁ +
In the scroll fluid machine, which is formed by an inner circular arc of r), the distance between the center of spiral of both scrolls is shorter by b than the normal distance r of center of spiral where there is no clearance in the radial direction. , Ε> 2e ₁ sin Ψ-be ₁ = (m ² + 2mf cosγ + f ² ) ^0.5 m = (R ₁ -R ₂ ) / 2, f = (R ₁ + R ₂ + r) / 2 γ = sin ⁻¹ (a / f) (0 ≦ γ ≦ π / 2) Ψ = b / 2a (where R ₁ = R ₂ A scroll fluid machine characterized by being formed uniformly thin by an amount of ε shown in (3). 3. The scroll fluid machine according to claim 1, wherein the outer circular arc radius of the driving scroll spiral protrusion is larger than the outer circular arc radius of the driven scroll spiral protrusion. 4. A drive scroll and a driven scroll, which rotate on mutually different axes and have spiral projections provided on a flat plate, and both the drive scroll and the driven scroll work together to form a compression chamber. , The shape of both spiral protrusions is the same, and the outer peripheral portion of each spiral protrusion is formed by an involute curve,
The inner circumference has a radius R that smoothly connects to the outer involute curve.
It is formed by the outer arc and the inner arc having a radius (R + r) that smoothly connects to the inner involute curve. The outer arc radius R of both scroll spiral projections is formed by R = ar-2. As a result, the scroll fluid machine is characterized in that the centers of the outer arc and the inner arc are arranged on the basic circle of the involute curve.