JPH0311103A - Scroll fluid machine - Google Patents

Abstract

PURPOSE:To make it possible to obtain excellent performance in a compression ratio and volume efficiency by setting the thickness of the scroll body of each scroll to dimension different from each other. CONSTITUTION:Scrolls 21 and 22 have base plates and scroll walls 21a and 22a forming enclosed space 23 which moves depending on a relative swing movement. At this point, the thickness of scroll walls 21a and 22a are set to dimensions which are different from each other. That is, the scroll thickness of the fixed scroll is set to a thickness smaller than the scroll thickness of the swing scroll 22. By this, the aperture of a exhaust port 24 can be enlarged without lessening stroke volume by the scroll body whose scroll-like parameter is different. Therefore, excellent performance in a compression ratio and volume efficiency, and so on can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll fluid machine, which is a type of positive displacement fluid machine.

[Conventional technology]

The basic principles of generally known scroll fluid machines are as follows.

Here, the basic elements of the scroll fluid machine are shown in FIG. 4, in which numerals 1 and 2 are a fixed scroll and an oscillating scroll, each of which is eccentrically assembled and has a spiral body of the same shape, and 3. are these both scrolls 1
．． A chamber 4 is a boat formed between 2 and 4 as a compression chamber.

First, if we consider the case where the scroll fluid machine is used as an oscillating compressor, the fixed scroll 1 is stationary with respect to space, and the oscillating scroll 2 is in rotational motion that does not change its attitude with respect to space, i.e. The rocking motion is performed at a predetermined crank radius (swing radius), and as shown in Fig. 4, the angle is O”, 90°,
Move as shown at 180° and 270°. At this time,
As the oscillating scroll 2 moves, the crescent-shaped chamber 3 formed between the fixed scroll 1 and the oscillating scroll 2 gradually decreases in volume. The fluid sucked into the chamber 3 is then compressed and discharged from the boat 4.

On the other hand, when used as an expander, 06.2
70. The fluid moves in reverse as shown at 180° and 90°, and the fluid is sucked into the chamber 3 from the boat 4, expanded, and discharged to the outer periphery of the vortex.

This is the operating principle of scroll fluid machines.

Although the above description is based on an oscillating scroll fluid machine for convenience, even if it is a double rotary scroll fluid machine in which both scrolls are eccentrically combined by a predetermined distance and rotate on their own axis, the two scrolls may be relative to each other. There is no essential difference in that they perform a rocking motion.

In addition, such a scroll fluid machine has the advantage that multi-point contact between both spirals is geometrically guaranteed for any spiral wall thickness, and it is easy to process.
As the spiral body, a spiral bift in the radial direction, a spiral wall with a constant thickness and an involute (circular expansion line) or a combination of circular arcs (polygon expansion line) are usually used.

By the way, in this type of scroll fluid machine, from the standpoint of volumetric efficiency, it is desirable that the discharge boat always communicate with the first compression chamber located at the innermost periphery. That is,
If there is a moment when the discharge boat communicates with the second compression chamber during one rotation, the volume of the first compression chamber becomes a so-called dead volume, which is disadvantageous in terms of compression ratio and volumetric efficiency. be. On the other hand, in terms of fluid resistance when discharging fluid, it is preferable to set the boat diameter to be as large as possible. For this reason, the boat diameter is set to be as large as possible within the range in which the vortex of the oscillating scroll is blocked by the inner end of the wall when discharge is completed.

(Problem to be Solved by the Invention) However, in conventional scroll fluid machines, both scrolls have spiral bodies of the same shape;
Even if the diameter of the discharge boat could be set to a large size, the stroke volume would be small. This can be understood from Fig. 5(a) and Fig. 5(a). Same figure (
In al, the thickness of the spiral bodies 11 and 12 is set to be larger than the thickness of the spiral bodies 13 and 14 shown in Q)) of the same figure, and the spiral pitch is set to the same dimension. Further, the diameter of the discharge boat 1516 is set to the maximum dimension as described above. As a result, there was a problem in that good performance in terms of compression ratio, volumetric efficiency, etc. could not be obtained.

The present invention has been made in view of these circumstances, and it is an object of the present invention to provide a scroll fluid machine that can obtain good performance in terms of compression ratio, volumetric efficiency, etc.

[Means to solve the problem]

In the scroll fluid machine according to the present invention, the thickness of the spiral body of each scroll is set to be different in size from each other.

[For production]

In the present invention, the diameter of the discharge boat can be increased without reducing the stroke volume due to the spiral bodies having different spiral shape parameters.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

Figures 1 (al to d) are plan views for explaining the operating principle of the scroll fluid machine according to the present invention. These scrolls 21.22 move by relative rocking motion to form a closed space 23 formed by a base plate (not shown) and a spiral wall 21.a.

22a, and a discharge boat 24 is provided on the base plate (not shown) of this fixed scroll 21. The thicknesses of the spiral walls 21a, 22a of each scroll 21, 22 are set to be different in size from each other. That is, the spiral thickness of the fixed scroll 21 is set to be smaller than the spiral thickness of the oscillating scroll 22. Note that the spiral pitches of both scrolls 21 and 22, that is, the basic circle radius of the involute curve are equal.

Next, it will be explained that in the scroll fluid machine configured in this manner, the spiral bodies are in contact with each other in the same way as in the conventional scroll fluid machine.

In FIG. 2, the spiral wall thicknesses are assumed to be t,, tz for a common base circle of radius a. The pitch of both spirals is p=2
πa is common.

t,=2aα.

From the relationship t, = 2a αZ, the spiral starting point angle α8. α2 is determined. here,
The oscillation radius r is calculated as r = (
p − (t++t*) 1 /2=a (π−(α,
+ α ri) ... (1), the coordinates of the expansion/opening angle 00 point on the inner surface of the spiral wall 21a (fixed scroll) are:
i=a (sin θ −(θ −α+) co
s θ ).

On the other hand, the point coordinates of the expansion/opening angle θ on the outer surface of the spiral wall 22a (oscillating scroll) in the rotating square type are x, o=-a (cos θ+(θ+α2) sin θ
)+r cos 'P...(2) Yto= a (sin θ-(θ+αz) cos
θ) r sin A (3). The expansion and opening angles of the points to be contacted at this time are θ, =
20π+π/2-A θ2=2nπ-π/2-A, so θ2 and A are θ, and 'P = 'l
nπ+π/2−θ, ...(4
)θ2 =01−π
...It is expressed as (5). (11, (4), f
Substituting 5) into (2), (31), x, o= a
(cos (θ1−π)+ (θ,−π+α2)・
5in(θ1-π') ) +a(π-α1(X
z) ・cos(π/2−θI)=a(cosθ1 +
(θ, −α+) sin θ1)=x °
...(6)y2゜=-a(s
in(θ1-π)=(θ1-π+α2)・cos (θ
, -π) l -a(π-α1α2)・5in(π/2
−〇,) = a(sinθ, −(θ1−α+) CO3θ”)=y
I...(7) Considering the slope at this point, dx+ i/dθIs, a=a(θ+ ”+)co
sθdV++/d/' Q, 6. =a(θ, −α,
) sinθ1-'-d)'th/dX+i l,,,=
Regarding the tano vortex device wall 22a, dx to/dθ1. ,, = −a (θ, +π−
α, ) stnθ2d Y zo/d 0144. =
a(θ2+yr−α,) cosθ2” dyXo
/dX1o 1. ,,=a tanθz −tan(θ
1-π) = ay eye/dx eye, ll, ...
(8) (6), (7L (From 81, it can be understood that the two spiral walls 21a and 22a having different spiral thicknesses are in contact with each other.

Furthermore, when comparing the scroll shown in Fig. 1 and the scroll shown in Fig. 3(a), the diameter of the discharge boat of the former scroll is the same as that of the latter scroll.
It can be seen that the stroke volume is large despite the dimensions.

This can be explained using the spirals shown in Figures 2 (a) to (C). In Figures (b) and (C), only the innermost ends of each spiral wall are set to different sizes. Among these, Figures (b) and (C) show In a spiral, the thickness of the fixed side spiral wall 51.52 is the same as that of the oscillating side spiral wall 53°5.
The dimensions are set to be smaller than the thickness of 4. In the figure, 55 to 57 are discharge boats.

In addition, in this example, the number of turns N of the spiral is N=1.
I showed an example of using 2.5 turns of ~3.5,
Of course, the present invention is not limited to this.

Further, in this embodiment, a case is shown in which the scroll fluid machine is of an oscillating type, but the same effects as in the embodiment can be obtained even when the present invention is applied to a double-rotation type scroll fluid machine.

Furthermore, the present invention can be applied not only to compressor-type and expander-type scroll fluid machines but also to transfer machine-type scroll fluid machines.

〔Effect of the invention〕

As explained above, according to the present invention, the thickness of the spiral body of each scroll is set to be different in size from each other, so that the diameter of the discharge boat can be reduced without reducing the stroke volume due to the spiral bodies having different spiral shape parameters. (can be made thicker), and good performance can be obtained in terms of compression ratio, volumetric efficiency, etc.

[Brief explanation of the drawing]

Figures 1 (a) to (dl) are plan views for explaining the operating principle of the scroll fluid machine according to the present invention; Figure 2 is a diagram for explaining contact between spiral bodies with different spiral thickness; 3(δ) to (C) are plan views showing scrolls in other embodiments, FIGS. 4(a) to (d) are plan views for explaining the operating principle of a conventional scroll fluid machine, and FIG.
FIGS. 18) and 18(b) are plan views showing conventional scrolls. 21... Fixed scroll, 21a... Spiral wall, 22... Oscillating scroll, 22a...
Swirl wall, 23...closed space, 24...discharge port. Agent Masuo Oiwa 1 Figure 4 26 Name of the invention Scroll fluid machine 3 Person making the amendment 5 Detailed description of the invention in the specification to be amended 6 Contents of the amendment ill Description page 9 Correct "Fig. 3 (a) J" in line 5 to "Fig. 5 (a)". (2) “This...
・It is set to a small size. ” shall be corrected as follows. 3 shows another embodiment of the present invention. In FIG. 3 fa), the spiral wall thicknesses of the spiral walls 31 and 32 are set to different dimensions throughout including the innermost end of the spiral. Same figure mountain 1. (
In C1, the spiral wall thickness of the fixed scroll and the oscillating scroll are basically equal, but at the innermost end of the volute, the fixed scroll is thinner and the oscillating scroll is thicker. Here, the time-wall thickness is Fig. 3 (bl) and Fig. 5 (
Comparing a) (conventional example), Fig. 3 (C), and Fig. 5 (b) (conventional example), the present invention can be achieved by simply making the fixed scroll thinner and the oscillating scroll thicker at the innermost end of the spiral. It is understood that the discharge boat can be made thicker than before.As shown in Figure 3 (al), for spirals with different thicknesses, the innermost end of the spiral can be compared to the spirals in Figure 3 (b) and (C). By making it the same as the innermost end, the effect of increasing the discharge boat without reducing the stroke volume becomes even more remarkable.'' (3) ``For scroll fluid machines'' on page 10, line 6 of the same book is changed to ``For scroll fluid machines.''
"to scroll fluid machinery" and amend it. (4) "In the present invention," on page 10, line 8 of the same book is amended to read "the present invention is."that's all

Claims (1)

[Claims] In a scroll fluid machine equipped with two scrolls each having a base plate and a spiral body, each of which is eccentrically combined with the other and forms a closed space in which the scrolls move by relative rocking motion, the thickness of each of the spiral bodies is set to A scroll fluid machine characterized by having different sizes.