JPS60222580A - Scroll fluid machinery - Google Patents

Abstract

PURPOSE:To improve the efficiency of a scroll compressor by forming a concaved part on a mirror plate so as to be along the inside of a lap over the angle of about 180 deg. from the winding edge part of a swirl scroll lap and reducing the pressure loss in a suction passage. CONSTITUTION:A circular groove 25 is formed onto a mirror plate 4 engaged with the lap part in the part 24 inside by about 180 deg. from the lap winding edge surface 23 in the outer edge part 2 of the swirl scroll lap 6 of the captioned scroll compressor, and the outside diameter D0 has a center coinciding with the center On of the mirror plate. Therefore, a coolant passage communicating to the suction chamber is made wide by the groove 25, and the pressure loss in suction can be reduced, and the efficiency of the scroll compressor can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a scroll fluid machine used in an expander or a compressor for a nitrogen conditioning machine, and particularly relates to an end plate that engages with an outer end of an orbiting scroll wrap. This invention relates to a scroll fluid machine in which a concave part is formed to widen the suction passage. <Background of the Invention> A conventional scroll fluid machine, for example, a scroll compactor for an air conditioner, is shown in FIGS. 1 to 3. As shown, it is equipped with a crown part consisting of a fixed scroll 1 and an orbiting scroll 2, both scrolls 1.2 having their respective circular mirror plates 3.
4, and a spiral scroll wrap 5.6 standing upright thereon and formed into an involute or a curve similar to this, and both wraps 5.6 are interlocked with each other inside. Being faced with.

The inner wall surface of the fixed scroll wrap 5, the outer wall surface of the orbiting scroll wrap 6, and the mirror plate 3 of both scrolls 1.2.
．． At the same time, a sealed space is formed by the wall surface of 4, etc., and at the same time, a closed space is formed by the outer wall surface of the fixed scroll wrap 5, the inner wall surface of the orbiting scroll wrap, and the wall surface of the mirror plate 3.4 of both scrolls 1.2. 8.12 are formed, and these constitute two symmetrical closed spaces.

Therefore, the suction chamber 13 of the scroll compressor has two suction passages 14 communicating with the outermost sealed space 7.8.
．． +5 is provided.

Moreover, the shape of the outermost peripheral wall surface of the groove forming the suction chamber 13 in the fixed scroll 1 is formed into an arc. If the scroll-type fluid machine configured in this way is used as a compressor for a refrigeration system, The low-volume, low-pressure refrigerant gas is supplied through an inlet 18 provided on the outer periphery of the end plate 16 of the fixed scroll 1.
The air is sucked into the suction chamber 13 on the outer circumference of the orbiting scroll 2 through the air.

The operating position of the quantity scroll 1.2 at the time of completion of suction is as shown in FIG.

Next, an orbiting scroll 2 is configured to rotate while being prevented from rotating via an Oldham mechanism (not shown).
Due to the rotating movement of the scrolls 1.2, the closed spaces 7 to 12 formed by the scrolls 1.2 are gradually reduced, so that the closed spaces 7.8
The refrigerant gas sucked into the scrolls 1.2 is transferred to the center of both scrolls 1.2, its temperature and pressure are increased, and the refrigerant gas is discharged to the outside from the central discharge hole 19.

The passage leading to the suction passage 14 is always maintained in a relatively wide state as shown in FIG.
The suction passage 15 that communicates with the outer edge of the fixed scroll wrap 5 and the outer edge 20 of the orbiting scroll wrap 6 that engages therewith repeats expansion, contraction, and reduction as the orbiting scroll 2 rotates.

Therefore, when the passage leading to the suction passage 15 is reduced as shown in FIG. 2, a pressure loss of suction pressure occurs.

When the suction passages 14 and 15 are reduced, the gap between them is F41. as shown in FIGS. 1 and 2, respectively. g2
It is indicated by.

In this case, the shape of the wall surface of the outermost periphery of the groove portion of the fixed scroll 1 forming the suction chamber 13 including the suction passages 14 and 15 is formed into a circular arc, and the center of the circular arc is the center of the head plate 3. The center of the arc of the wall surface 14 is the fixed scroll wrap 50
It also coincides with the center of the base circle.

In such a configuration, the outermost wall surface 16 of the groove portion forming the suction chamber 13 has a size of DSi1+ shown in FIG.
) is given by the following equation:

Del=2(a%e+ε+92)・(1) where D
Inner diameter a of the siH suction chamber 13 = base circle radius of the scroll wrap... ri... winding end angle of the wrap (expansion/opening angle of the heppolute) ε: turning radius g2: arc-shaped wall surface 14 and Minimum clearance between the orbiting scroll wrap and the side wall FIG. 4 shows the positional relationship between the scroll wrap winding angle (involute expansion/opening angle), the base circle radius a, and the involute curve C.

Therefore, based on the above formula (1), the shape of the suction chamber 13 of the fixed scroll 1 or the outer shape D of the fixed scroll 1 is determined.
fo is round.

Therefore, the tooth profile shape of the scroll wrap (for example, (
1) When it is desired to reduce the size of the entire fixed scroll (dimension Dfo in FIG. 3) as the dimensions a and -λe1ε of the equation are determined.

The I・ It is impossible to reduce the dimension 62 in the above formula (1).

Therefore, if the dimension 62 is reduced, the above-mentioned suction passage 1
This creates performance problems such as an increase in child losses in the case of 5.

FIG. 3 shows an enlarged cross section of the suction passage 15, showing the side wall surface 2 of the outer edge 21 of the orbiting scroll wrap 6.
2, and a mirror plate 3 of the fixed scroll 1 facing this side wall surface.
The gap between the outer periphery of the scroll and the side wall surface 16 changes with the orbiting movement of the orbiting scroll 2, as described above.

Then, the maximum gap l can be determined from the above-mentioned minimum gap g2 using the following equation (2).

1=g2+2ε...(2) Therefore, the area of the suction passage is determined by the product of the above-mentioned gap and the height h of the scroll wrap, and the passage area of the suction passage is also the same as the above-mentioned gap. In the suction section 14, the gap B1 forming the suction passage 15 is always maintained in an enlarged state regardless of the rotation movement, and the suction passage 15 and the end plate 3.4 of the orbiting scroll 2 The center of the scroll wrap 5.6 coincides with each center of the base circle of the scroll wrap 5.6.

In such a compressor structure, the two suction passages 14.
Since the GL and GL formed in 15 have different structures, as the refrigerant gas flows to the suction passage 14.15, in addition to the friction loss between the refrigerant gas and the passage wall surface, the passage due to the orbiting movement of the orbiting scroll. Pressure loss and pressure fluctuation occur due to changes in area and wide changes in shape such as bending.

That is, the graph shown in FIG. 5 is the acupressure line of the conventional scroll compressor shown in FIGS. 1 to 3, and the vertical axis shows the pressure (
When the volume (V) is plotted with P) as the horizontal axis, in the conventional mode, as shown in FIG. The pressure immediately before compression is P s (11+, P s 02), and since compression starts from this point, the acupressure line is drawn so that the pressure rise in the closed space 9.1o is shown by the actual pressure and the broken line. Two diagrams are drawn. In this situation, a pressure difference (for example, ΔP) with a volume of Vl occurs between the closed spaces 9 and 10 forming the compression chamber, causing leakage between them, and the overall However, the disadvantage was that the power of the compressor increased.

Also, like the gap g2 of the suction passage 15, the suction passage 1
If the suction passage becomes extremely narrow compared to No. 4, the pressure loss and pressure fluctuation in this portion will increase, so there is a risk that the performance will decrease due to a decrease in the volumetric efficiency of the compressor.

Furthermore, due to the difference in the width of the suction passage leading to the suction passage 14.15, the magnitude of pressure loss and pressure fluctuation in the suction passage 14.15 differs, so the pressure of the refrigerant gas immediately before compression also differs. Therefore, a pair of compression chambers 1 forming a sealed space, e.g., sealed space 7.8.9 in FIG.
．． Since a pressure difference is generated between the compressors 10 and 10, the amount of leakage increases due to this pressure difference, and the motive power of the compressor also increases, which in turn causes a problem that promotes the deterioration of the fully adiabatic moving vehicle.

In addition, the pressure loss in the suction passage 14.15 becomes more noticeable when the compressor #1 rotates at high speed.
If the speed is increased to speeds such as m, there are disadvantages such as a significant drop in performance.

<Objective of the Invention> The object of the present invention is to solve the problems of fluid mechanisms such as scroll compressors based on the above-mentioned prior art, and
It is an object of the present invention to provide an excellent scroll fluid mechanism that reduces pressure loss in the suction passage between the scroll wraps of a fixed scroll and an orbiting scroll and improves performance, thereby benefiting the field of fluid application in the energy industry.

<Summary of the Invention> In order to solve the above-mentioned problems, the present invention, which is based on the above-mentioned object and is summarized in the above-mentioned claims, is to solve the above-mentioned problem. A concave portion is formed in the end plate that engages with the wrap portion up to the inner wrap winding position to widen the suction passage in the suction chamber formed by both scrolls, and
The wrap in the above-mentioned lathe has a uniform thickness from its inner wall surface,
and the thickness of the scroll wrap is formed to be thinner than the thickness of the inner scroll wrap within the above range, a recess is formed in the end plate that engages with the wrap portion of the thin portion, and further a recess provided in the end plate of the orbiting scroll. and the side wall of the outermost periphery of the groove on the fixed scroll side in the suction chamber formed by both scrolls, where DO1 is the inner diameter of the suction chamber, DO is the outer diameter of the recess, and ε is the turning radius, DO1≧ Do-1-
This method takes technical measures to satisfy Z・ε.

<Example> Next, an example of the present invention will be described below based on the drawings from FIG. 6 onwards. The same parts as in FIGS. 1 to 3 will be described using the same reference numerals.

In the embodiment shown in FIGS. 6 to 8, it engages with a part of the outer edge 2 of the orbiting scroll wrap 6 of a scroll compressor for an air conditioning machine, halfway from the end surface 3 of the wrap to -24, approximately 180 degrees inward. A concave portion of an arc-shaped groove 25 is formed in the mirror plate 4, and has an outer diameter DoVi and a center coincident with the center Om of the mirror plate 4.

Therefore, by forming the nuclear recess 25, the suction chamber 13 is
The refrigerant passage is kept wide compared to conventional machines.

Further, in the embodiment shown in FIG. 9, the end plate 4 of the orbiting scroll 2
A concave portion 30' provided in
End plate 4 that engages with the lap portion until just before the inner position 24
This is an embodiment formed in the same manner as above.

In addition, in the embodiment shown in FIG. 10.11, the wrap 6' from the end surface 23 of the wrap winding end 23 at the outer end 6' of the orbiting scroll wrap 6 to a position 24 located approximately 180 degrees inward is separated from the inner wall surface thereof. , and its lap thickness tli is thinner than the thickness t of the preceding lap 6 ((1
-1(t) This is an embodiment in which a concave portion 30'' is formed in the end plate 4 which engages with the wrap portion 6' of the thin wall portion.

By making the recessed portion 30° as described above, the suction passage can be made even wider. The range of the thin wall portion 6' of the knob 6 is not limited to the above-mentioned positions 23 and 24, and the same effect as described above can be obtained even if the thin wall portion 6' is formed between the positions at an appropriate wrap angle between the positions 23 and 24. .

In addition, the recessed portion 30°'' provided in the end plate 4 of the above-mentioned orbiting scroll
The positional relationship between this and the side wall 16 at the outermost circumference of the groove on the fixed scroll 1 side in the suction chamber 13 formed by both scrolls 1.2 is as follows: Dsi≧Do-1-Z-ε-(3) where (Ilsi: inner diameter of the suction chamber, DO: outer diameter of the recess, ε: turning radius).
Set O.

The end plate sliding portion 31, which is the outer edge of both scrolls 1.20 m3.4, performs lubrication and sealing between the suction chamber 13 and the back space of the orbiting scroll 2.

This ensures the sealing performance of the axial sliding portions 31 of both scrolls 1.2.

<Effects of the Invention> According to the present invention, in the scroll fluid mechanism, by forming a recess at the outer edge of the scroll wrap in the end plate of the scroll 2, the suction passage is widened and the pressure loss is reduced. The excellent effects of eliminating leakage, suppressing the increase in power, and improving thermal efficiency are achieved.

In the above-described embodiment, since the suction passages have approximately the same area, the pressure loss in the passages is also approximately the same, and as shown in FIG. 12, the pressure (
When P) is taken as the volume (V) on the horizontal axis, the pressure immediately before compression in the two suction spaces is both peo in the acupressure diagram shown in contrast to the acupressure line graph of FIG. Since compression starts from this pressure, the solid line and dotted line become one in the acupressure diagram, and there is no pressure difference between the two compression chambers.Therefore, there is no leakage of the compression space, and the Ichida force is improved. It turns out that it can be achieved.

That is, by forming the concave portion for the suction passage in the end plate of the orbiting scroll, the weight of the orbiting scroll is reduced, which has the effect of reducing the weight of the compressor as a whole.

Next, an example of this invention and the prior art is JP-A-57-13.
Regarding the differences in operation and effect from the invention disclosed in Publication No. 7601, the horizontal axis represents the compressor rotation speed No, and the vertical axis represents the suction pressure loss JPs and the centrifugal force F acting on the orbiting scroll.
To explain the comparison using FIG. 13, which takes c. The loss, dos, is a value expressed by the following equation.

aP s = P s - P e o ・= (4) Here, Pθ: Suction pressure (pressure outside the compressor, for example, inside the suction pipe) (K9/cd) −, Psi: Pressure in the suction chamber 3 (3kl) K9/d) Also, the centrifugal force Fa acting on the orbiting scroll is divided by the value expressed by the following formula: 0 Fc=We/g-ε, ω2. (5) Here, Ws: Weight of the orbiting scroll (K9) g: Acceleration of gravity (m7g) ε: Radius of rotation (m) U: Rotational angular velocity of the main shaft (=2yLNs/60)
(r a d/s) Ns: rotational speed of the main shaft (rpm) Therefore, in this invention, since the suction passage is secured wider than in the conventional mode, the suction pressure loss ΔP8 is reduced,
In particular, high-speed rotation of scroll compressors (for example, N""
70,000 rpm), the difference in results is clear compared to the conventional machine.

In addition, since the centrifugal force Fc acting on the orbiting scroll is further reduced, the excitation force itself acting on the scroll compressor is also reduced, making it possible to provide a scroll compressor with low vibration compared to conventional machines. There is.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing the compressed state of a conventional scroll fluid machine, Figure 3 is a cross-sectional view of essential parts of a conventional scroll fluid machine, and Figure 4 is a cross-sectional view of the spiral curve of the wrap. , Fig. 5 shows the conventional mode.

Claims (1)

[Scope of Claims] In a scroll fluid machine that compresses fluid by reduction, approximately 180 degrees inward from the end surface of the lap winding end at the outer end of the orbiting scroll wrap (located in the scroll wrap portion up to the lap winding position) A scroll fluid machine characterized by the fact that a concave portion for lowering a suction passage is formed entirely in the end plate. (2) A patented roll fluid machine characterized in that the concave portion has a generally fan-shaped groove shape. (3) The scroll mentioned above The thickness of the scroll wrap from the end surface of the wrap winding end at the outer end of the wrap to the wrap winding position approximately 180 degrees inward from the inner wall surface, and the thickness of the scroll wrap is uniform. The scroll fluid machine according to claim 1, wherein the scroll wrap is formed thinner than the thickness of the scroll wrap on the inner side of the range. The positional relationship with the side wall of the outermost periphery of the groove on the fixed scroll side in the suction chamber is expressed by the formula Dai≧Do-}-Z・ε~ (here, DsiH the inner diameter of the suction chamber, Do the outer diameter of the recess, ε: A scroll fluid machine according to any one of claims 1 to 3, characterized in that the scroll fluid machine is formed to satisfy a radius of gyration.