JPH04121482A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To improve compression efficiency by a high compression ratio by forming the inner wall curved surface of each blade part of a fixed scroll blade and a turning scroll blade into respective specific curves from the winding end angle of the blade part to a determined angle and from there to the winding start angle. CONSTITUTION:In the blade part 10B of a turning scroll blade, its inner wall curved surface (m) is formed into a curved surface laid along a standard involute curve from a winding end angle phi0 to an angle (phi0-2pi) and a deformed involute curve which is a curve shifted inward from the standard involute curve in proportion to the winding angle phi of the blade part 10B, from this angle (phi0-2pi) to a winding start angle 0. The outer wall curved surface (n) is formed into a curved surface laid along the standard involute curve from the winding end angle phi0 of the blade part 10B to an angle (phi0-3pi), and deformed involute curve which is a curve shifted inward from the standard involute curve in proportion to the winding angle phi of the blade part 10B from this angle (phi0-3pi) to the winding start angle 0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention relates to a scroll compressor that constitutes a refrigeration cycle of an air conditioner, for example, and particularly relates to a fixed This invention relates to improvements in the shape of blades in scroll blades and orbiting scroll blades.

(Prior art) For example, compared to a normal rotary compressor used as a compressor that constitutes the refrigeration cycle of an air conditioner,
Scroll compressors, which have extremely low motion noise and high compression efficiency, are increasingly being used.

This type of scroll compressor is constructed as shown in FIG. 7, for example. That is, 1 is a closed case.

A frame 3 is provided within the sealed case 1 via a frame support plate 2 so as to partition the inside of the sealed case 1 into upper and lower parts. An electric motor section 4 is provided on the upper part of the frame 3,
A scroll compression mechanism section 5 is provided at the bottom.

The electric motor section 4 has a stator 6 fitted into the sealed case 1.
and a rotor 7 provided within the stator 6 with a narrow gap.

A main shaft 8 is fitted into the rotor 7 along its axis, and the main shaft 8 is rotatably supported by the frame 3 and extends to the scroll compression mechanism section 5.

That is, these scroll compression mechanism section 5 and electric motor section 4
are connected to each other via the main shaft 8.

The scroll compression mechanism section 5 includes a fixed scroll blade 9 that is fixedly attached to the frame 3, and an orbiting scroll blade that meshes with the fixed scroll blade 9 so as to be able to rotate freely and forms a compression chamber S in the mutual space. It consists of 10.

The fixed scroll blade 9 includes a mirror plate portion 9a and a spiral wing portion 9b standing upright at one end of the mirror plate portion 9a. A flange portion 9C integrally provided on the periphery of the mirror plate portion 9a is fixedly attached to the frame 3. The orbiting scroll blade 10 includes a mirror plate portion 10a and a spiral wing portion 10b standing upright at one end of the mirror plate portion 10a. A boss portion 10c integrally provided on the mirror plate portion 10b is pivotally engaged with a boss portion 8a provided integrally with the lower end portion of the main shaft 8 and eccentrically from the shaft center.

A balancer 11 is fitted to the boss portion 8a at the lower end of the main shaft 8, and the frame 3 and the orbiting scroll j! A thrust ring 12 is interposed between the end plate portion 10a of 10 and the end plate portion 10a. In the figure, reference numeral 13 denotes an Oldham ring for preventing rotation of the orbiting scroll 10 as it rotates.

A suction pipe 14 passes through the lower part of the sealed case 1, and its open end is connected to the flange portion 9C of the fixed scroll JI9.
The outer periphery of the compression chamber S can be seen from here.

A gas discharge passage 15 is provided which communicates with the axis of the boss portion 10c of the orbiting scroll blade 10 and the axis of the main shaft 8. The gas discharge passage 15 of the main shaft 8 opens into the closed case 1 at the upper end of the main shaft 8, and a discharge pipe (not shown) is provided at the upper end of the closed case 1.

In the scroll compressor configured in this manner, the electric motor section 4 is energized to drive the scroll compression mechanism section 5. That is, when the orbiting scroll 10 is rotated relative to the fixed scroll blade 9, a fluid to be compressed, such as low-pressure refrigerant gas, is sucked into the compression chamber S from the suction pipe 14 and compressed. This compression chamber S gradually shrinks, and when it moves to the center, the pressure rises to a predetermined pressure. The refrigerant gas is discharged into the discharge gas passage 15, and then first discharged into the sealed case 1, and then guided to a predetermined external device via the discharge pipe. The electric motor section 4 is controlled to an optimal operating frequency according to the load, and air conditioning can be performed under optimal conditions.

(Problems to be Solved by the Invention) By the way, the blade section 1 in the conventional orbiting scroll blade 10
8 shows the cross-sectional shape of 0b, and FIG. 9 shows the cross-sectional shape of the wing portion 9b of the fixed scroll blade 9. Each of the wing parts 10b and 9b has a uniform plate thickness from the winding start end O to the winding end end O5, and is curved along a standard involute curve.

A compression process in the scroll compression mechanism 5 equipped with such an orbiting scroll blade 10 and a fixed scroll blade 9 is shown in FIG. 10. That is, the horizontal axis represents the rotation angle θ (D E C) of the main shaft 8, and the vertical axis represents the pressure P of the compression chamber S.
(kg/cd-G) and the compression ratio is plotted on a portion of the vertical axis. The different change curves are for the wing portions 10b and 9.
The number of turns of b is N.

As is clear from the figure, regardless of the number of turns N, the compression process is determined only by the number of turns N of the blades 10b and 9b and the rotation angle θ of the main shaft 8 after the refrigerant is confined in the compression chamber S. It will be decided. Therefore, the pressure of the fluid to be compressed in the compression chamber S rises more slowly than necessary, and a higher compression ratio cannot be achieved.

Further, each wing portion 10b, 9b has a winding start end 0
Starting end of winding 0. As mentioned earlier, the thickness is uniform throughout. On the other hand, the compression chamber S
The pressure increases from the outer periphery to the center of the blade portions 10b and 9b, and the pressure is highest at the center. That is, although the pressures received are different over the entire length of the wing parts 10b and 9b, the plate thickness is uniform, so the reliability of the strength particularly at the central part of the wing parts 10b and 9b is low.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to change the plate thickness of the fixed scroll blade and the orbiting scroll blade to an ideal state, so that the compressed fluid in the compression chamber can be reduced. The purpose of this invention is to provide a scroll compressor that can speed up the pressure rise and improve compression efficiency through a higher compression ratio, as well as increase strength and reliability, particularly in the center of the blade section.

[Structure of the Invention (Means and Effects for Solving the Problems) That is, the present invention provides a fixed scroll wing having a spiral wing section erected at one end of the end plate. In a scroll type compressor, in which orbiting scroll blades each having a spiral blade section vertically engaged with each other so as to be able to rotate, and compressing and discharging a fluid to be compressed in a compression chamber formed between these blades, the above-mentioned fixed scroll The wing portions of the blades and the orbiting scroll blades each have their inner wall curved at an angle (φ, −
2π) and its outer wall curved surface to the winding end angle φ of the wing part.
. to the angle (φ.-3π) is formed by a standard involute curve, and from the angle of the inner wall curved surface (φo-2π) to the winding start angle 0, and the angle of the outer wall curved surface (φo3π
) to the winding start angle O are formed into curves that are shifted inward by K (mie/2π two reduction coefficients) from the standard involute curve in proportion to the winding angle φ of the blade part. It is a compressor.

In such a scroll compressor, during compression, the center of the blade receives stronger pressure than the outer periphery. However, the wing section has a thick wall from the middle to the center, and both the inner wall curved surface and the outer wall curved surface have an ideal shape, so the compression speed is increased, a high compression ratio is achieved, and the strength of the wing section itself is increased. increases.

(Example) An example of the present invention will be described below based on the drawings. Since a mold compressor can be applied, further explanation will be omitted here.

FIG. 1 shows the cross-sectional shape of the wing section 10B in the orbiting scroll wing, and FIG.
B shows the cross-sectional shape. The cross-sectional shapes of these wing portions 10B and 9B are the same as those of the conventional art in that they are symmetrical and have the same shape.

As for the actual cross-sectional shape, in the wing portion 10B of the orbiting scroll blade shown in FIG. 1, the winding end angle φ is the end of the winding. Both the inner wall curved surface m and the outer wall curved surface n do not change until a predetermined midway point toward the winding start angle 0, which is the winding start end, but change thereafter. That is, the winding end angle φ on the inner wall curved surface m of the wing portion 10B
. to the angle (φo 2π) is a curved surface that follows a standard involute curve similar to the conventional one. This angle (φ
. -2π) to the winding start angle 0, the deformed involute curve is a curve that is shifted inward from the standard involute curve by K (m+m/2π: reduction coefficient) in proportion to the winding angle φ of the blade portion 10B. is formed. Further, the outer wall curved surface n is the winding end angle φ of the wing portion 10B. to the angle (φo3π) is a curved surface that follows a standard impolinated curve similar to the conventional one. This angle (φ.-3π) until the empty winding start angle 0 is proportional to the winding angle φ of the blade portion 10B, and is smaller than the standard involute curve by
A modified involute curve is formed, which is a curve shifted inward by 2π: reduction coefficient).

Also in the wing section 9B of the fixed scroll wing shown in FIG.
The winding end angle φ of the inner wall curved surface m. Gara angle (φo2π
) is a curved surface that follows the same standard impoline curve as before, and from this angle (φ.-2π) the winding start angle O
A modified involute curve is formed, which is a curve that is proportional to the winding angle φ of the wing portion 9B and is shifted inward by K (mm/2π: reduction coefficient) from the standard involute curve. Further, the outer wall curved surface n is the winding end angle φ of the wing portion 9B.

It is a curved surface that follows the same standard involute curve as before from the angle (φo3π), and from this angle (φo-3π) to the winding start angle 0, the standard involute curve than K(mm/2π:
A modified involute curve is formed, which is a curve shifted inward by the reduction factor. Note that K(+m/2π) is a proportionality constant that determines the rate of reduction of the involute curve. (K>O) In FIG. 3, a solid line X indicates a change in plate thickness with respect to the involute winding angle φ in the wing portions 10B and 9B of the orbiting scroll wing and the fixed scroll wing formed in this manner. The broken line Y indicates the plate thickness according to the conventional standard involute curve.

The plate thickness T' according to the conventional standard invo-lute curve is 2
It is expressed as aα (a is the base circle radius, α is the starting angle of the involute) and does not change over its entire length.

On the other hand, the new blade thickness change X is φ. −2π
≦φ≦φ. In the range of TNT' m2aα, the plate thickness is the same as that of the conventional one.

φ. In the range of -3π≦φ≦φo 2π, the plate thickness is T-T'/2π ((φ.-2π)-φ).

In the range of φ≦φo−3π, The plate thickness is T-T'+2.

Thus, the blade portions 10B and 9B of the orbiting scroll blade and the fixed scroll blade are meshed to perform compression operation. At the moment when the uncompressed gas is confined in the outermost compression chamber, that is, when the rotation angle θ of the main shaft 80 is 0, this compression chamber is formed only by the conventional involute curve, so that the conventional wing portion 10b , 9b is obtained as the excluded volume.

Then, when the main shaft 8 rotates and the compression chamber located on the outermost side gradually moves inward to reach θ degrees, the compressed state as shown in FIG. 5 is achieved. That is, at least a portion of the compression chamber S1 is covered by the newly set modified involute curve, and its displacement volume is smaller than the displacement volume of the compression chamber formed by the conventional standard involute curve.

FIG. 6 shows the compressed state of the blade portions 10b and 9b formed by the conventional standard involute curve at the same angle (θ degrees). The displaced volume is larger than the displaced volume of the compression chamber S formed by the new deformed involute curve.

This state continues until the position where the compression chamber S1 faces the discharged gas passage 15, that is, the winding start angle is 0. As a result, the rate of pressure rise in the compression chamber S formed by the modified involute curve shown in FIG. 5 is greater than in the compression chamber S1 formed by the conventional standard involute curve. The rate of pressure increase is the pressure velocity, and the faster the pressure velocity, the higher the compression ratio. In addition, the pressure in the compression chamber S gradually increases from the outer periphery to the center of each wing section 10b, 9b, but the plate thickness of the wing sections 10b, 9b is set closer to the center than at the outer periphery. The increased thickness increases strength and improves reliability.

As an example, FIG. 4 shows calculation results of the pressure increase process in the compression chamber S with respect to the rotation angle θ of the main shaft 8 when the number of windings of the blade portions 10b and 9b is 4. The parameters in the figure are dimensionless reduction coefficients obtained by dividing the reduction coefficient K by the turning pitch P, and K-0 is for a conventional involute blade. Therefore, as in the present invention, as the dimensionless reduction coefficient K is increased, the compression speed becomes higher and a higher compression ratio can be obtained.

[Effects of the Invention] As explained above, according to the present invention, each of the fixed scroll blade and the orbiting scroll blade has its inner wall curved surface at an angle (φo−2π
) and the outer wall curved surface to the winding end angle φ of the wing. The angle from (φo 3π) is formed by a standard involute curve, and the angle from the inner wall curved surface angle (φ.-2π) to the winding start angle and the outer wall curved angle (φ.-3π)
From to the winding start angle, the curves were formed to be shifted inward by K (ms/2π: reduction coefficient) from the standard impolinated curve in proportion to the winding angle of the wing, so the outer diameter of the wing Moreover, the compression speed can be increased without changing the height dimension, and the compression efficiency can be improved due to a high compression ratio.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view of a wing section of an orbiting scroll wing showing an embodiment of the present invention, Fig. 2 is a cross-sectional plan view of a wing section of a fixed scroll wing, and Fig. 3 is a diagram of changes in plate thickness of each wing section. , FIG. 4 is a characteristic change diagram of the dimensionless reduction coefficient, FIG. 5 is a diagram showing the shape of the compression chamber during compression, FIG. 6 is a diagram showing the shape of the compression chamber during compression in the conventional example of the present invention, Fig. 7 is a partially omitted vertical cross-sectional view of a scroll compressor, Fig. 8 is a cross-sectional plan view of the wing section of an orbiting scroll wing showing a conventional example of the present invention, and Fig. 9 is a cross-sectional view of the wing section of a fixed scroll wing. The plan view and FIG. 10 are compression process characteristic diagrams at different numbers of windings of the wing portion. 9a... End plate part, 9B... Wing part, 9... Fixed scroll wing, 10a... End plate part, IOB... Wing part, 1
o...Orbiting scroll blade, S...Compression chamber, m...
Inner wall curved surface, n...outer wall curved surface.

Claims (1)

[Claims] For a fixed scroll wing consisting of an end plate part and a spiral wing part erected at one end of this end plate part, the end plate part and
An orbiting scroll blade consisting of a spiral blade installed upright at one end of this mirror plate part is engaged with the rotating scroll blade so as to be able to rotate freely, and the fluid to be compressed is sucked into the compression chamber formed between them, compressed, and discharged. In a scroll compressor, each of the fixed scroll blade and the orbiting scroll blade has its inner wall curved at an angle (φ_0-2) from the end winding angle φ_0 of the blade.
π) and its outer wall curved surface to the winding end angle φ_
The angle from 0 to (φ_0-3π) is formed by the standard involute curve, and the angle of the inner wall curved surface (φ_0-2π) is
to the winding start angle 0, and the angle of the outer wall curved surface (φ_
From 0-3π) to the winding start angle 0, the winding angle φ of the wing is
K (mm/
A scroll type compressor characterized in that each curve is formed to be shifted inward by 2π (reduction coefficient).