JP3401051B2 - Fluid compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral type fluid compressor suitable for compressing refrigerant gas in a refrigeration cycle, for example.

[0002]

2. Description of the Related Art Reciprocating type compressors, rotary type compressors, and the like have been known as general compressors. In addition, a refrigerant flowing from a suction end side of a cylinder into a working chamber is discharged from the cylinder. There is provided a spiral type fluid compressor in which the fluid is compressed while being sequentially transferred to the working chamber and discharged to the outside.

An outline of the spiral type compressor is shown in FIG.
As shown in FIG. 7, a cylinder 105 rotated by a driving unit composed of a stator 101 and a rotor 103, and an Oldham mechanism 107 eccentrically arranged in the cylinder 105 by e.
And a rotating body 109 that can rotate relative to the cylinder 105. A spiral groove 111 is formed on the outer peripheral surface of the rotating body 109 over substantially the entire length.
A spiral blade 113 is fitted in the shaft 1 so as to be retractable. The outer peripheral surface of the blade 113 is in close contact with the inner peripheral surface of the cylinder 105, and the blade 113 rotates integrally with the rotating body 109. Since the rotating body 109 with respect to the cylinder 105 is eccentrically rotated by the Oldham mechanism 107, a relative speed is generated between the outer peripheral surface of the rotating body 109 and the cylinder inner peripheral surface facing the rotating body 109, and the relative speed is one rotation. It changes as one cycle. Therefore, as described above, the blade 113 projects into and out of the spiral groove 111, whereby a plurality of working chambers 115 are formed in the space between the rotating body 109 and the cylinder 105 along the axial direction. . The volume of the working chamber 115 is determined by the pitch P of the spiral groove 111 into which the blade 113 is fitted as shown in FIG. 28, and the pitch P of the groove 111 gradually increases from one end to the other end of the rotor 109. It is getting smaller. Therefore, the volume of the working chamber 115 formed by the blade 113 gradually decreases from the suction end side of the rotating body 109, which is the suction pipe 117 side, toward the discharge end side, which is the discharge pipe 119 side. The structure is such that it is compressed and discharged to the outside while being sequentially transferred to the discharge end side.

[0004]

As described above, since the working chamber 115 for compressing the refrigerant is created by the spiral blade 113, the blade 113 does not deteriorate in its properties even when exposed to the refrigerant. Various performances required for the are required. For example, elastically deformable low rigidity performance is required so that the groove 113 can be easily fitted.
Therefore, the blade 113 has a small friction coefficient,
A synthetic resin having properties such as refrigerant resistance, heat resistance, and low flexural modulus is most suitable. Specifically, it is tetrafluoroethylene resin (hereinafter referred to as PTFE) or tetrafluoroethylene and perfluoroalkyl. Vinyl ether copolymer resin (hereinafter, P
FA) is considered. Also, the blade 113
It has been considered to use a composite material filled with glass fiber or carbon fiber for the purpose of improving the sliding characteristics of the above and the deformation due to the differential pressure, but all of these materials have a large dimensional change due to thermal expansion. Has drawbacks.

On the other hand, the coefficient of performance of the fluid compressor (refrigerating capacity /
The load power) is greatly affected by the clearance between the blade 113 and the spiral groove 111.

With respect to the clearance Pt and the depth Ph of the groove 111 in FIG. 29, the clearance is the width Bt shown in FIG.
A gap is formed when the blade 113 in the depth direction Bh is inserted into the groove 111, and this gap serves as a clearance. Further, when the clearance groove width direction is Ct and the groove depth direction is Ch, it is necessary to seal the refrigerant gas in both Ct and Ch, which affects the coefficient of performance. Therefore, it is ideally desirable that the clearance within the range in which the refrigerant gas can be sealed by the oil film of the lubricating oil be uniformly formed in any direction of the cross section of the blade 113.

However, as a practical problem, the operating temperature range (temperature rise) of the fluid compressor changes depending on the configuration of the fluid compressor (compression ratio, refrigerating capacity, operating rotation speed, type of refrigerant gas, etc.). Also, as a matter of course, it varies depending on the ambient temperature depending on the season when the machine is stopped and when the machine is operating. Therefore, there is a problem that the amount of dimensional change due to thermal expansion of the blade 113 is different.

The cross-sectional dimension of the blade 113 is shown in FIG.
As shown in Nos. 1 and 32, the blade 11 is formed so that the groove depth direction is larger than the groove width direction and that the blade 11 has a single linear expansion coefficient.
In the case of configuring No. 3, a difference occurs in the dimensional change amounts Dt and Dh of the blade 113 due to thermal expansion, and the clearances Ct and Ch
But different problems occur.

Further, the size of the fluid compressor may cause deviation from an appropriate clearance range. For example, for the blade 113 having a sufficient size and the small blade 113, the amount of dimensional change (D
t, Dh) are different. Therefore, when the clearance is large, the sealing performance may be deteriorated or the blade 113 may fall due to the differential pressure. Further, when the clearance is small, the resistance when the blade 113 moves in and out of the groove 111 is increased, so that the fluid compressor is increased. The load power increases and the coefficient of performance decreases. Further, when the blade 113 is made of a material having a large linear expansion coefficient, the blade has a small size in order to secure an appropriate clearance, and there is a problem that a predetermined refrigerating capacity cannot be obtained.

In other words, there is a problem that the dimension of the blade 113 changes due to thermal expansion and that the clearance range deviates from an appropriate range depending on the dimension ratio of the fluid compressor.

Therefore, an object of the present invention is to provide a fluid compressor which is not affected by thermal expansion and is excellent in sealability and has a high coefficient of performance.

[0012]

To SUMMARY OF THE INVENTION To achieve the above object, the present invention is disposed eccentrically along the sheet cylinder and the axial direction of the cylinder, contacting a portion of the inner peripheral surface of the cylinder the rotating body of the cylinder relatively pivotable cylindrical state, rotating body outer circumference provided spiral formed by gradually becomes smaller pitch in the discharge end from the suction end of the cylinder A groove and a spiral blade that is inserted into and retracted from the groove and has an outer peripheral surface that is in close contact with the inner peripheral surface of the cylinder and that divides the cylinder and the rotating body into a plurality of working chambers. However, at the time of turning of the rotating body,
In the fluid compressor that sequentially transfers the refrigerant flowing from the suction end side to the working chamber on the discharge end side, the blade has a dimension relative to the cross-sectional dimension ratio in the groove width direction of the spiral groove and the groove depth direction. The side with a small ratio has a large linear expansion coefficient, the side with a large dimensional ratio has a small linear expansion coefficient, and the product of the dimensional ratio of the blade cross section and the ratio of the linear expansion coefficient is at least 1 ± 0.2 . Range.

The dimensions of the spiral groove of the blade cross section in the groove width direction and the groove depth direction are such that the coefficient of linear expansion on the smaller side is 20 × 10 ⁻⁵ / ° C. (value in the range of 30 to 150 ° C.). It is composed of the following tetrafluoroethylene resin or a composite material of ethylene tetrafluoride and a perfluoroalkyl vinyl ether copolymer resin.

[0014]

According to such a fluid compressor, the blade has a cross-sectional dimension ratio in the groove width direction and the groove depth direction of the spiral groove,
The side with a small dimensional ratio has a large linear expansion coefficient, the side with a large dimensional ratio has a small linear expansion coefficient, and the product of the dimensional ratio of the blade cross section and the linear expansion coefficient is 1 ± 0.2.
By setting the above range, the amount of dimensional change due to thermal expansion becomes uniform regardless of the size configuration of the spiral groove of the blade in the groove width direction and the groove depth direction, and a substantially constant clearance can be obtained. Further, in the dimension of the blade cross section in the groove width direction and the groove depth direction, the linear expansion coefficient in the direction with the smaller dimension is 20 × 10.
^-5 / ° C. (value in the range of 30 to 150 ° C.) or less, and by being composed of a tetrafluoroethylene resin or a composite material of tetrafluoroethylene and a perfluoroalkyl vinyl ether copolymer resin, various characteristics of the blade are not impaired. Therefore, the optimum clearance can be obtained, and stable sealing performance can be secured for a long period of time.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings of FIGS. In FIG.
Reference numeral 1 denotes a closed case of a closed type fluid compressor 3 used in a refrigeration cycle. One side of the closed case 1 is provided with a suction pipe 5 of the refrigeration cycle and the other side is provided with a discharge pipe 7. . In the closed case 1, an electric element 9 as a driving means and a compression element 11 as a compression means.
Are arranged respectively.

The electric element 9 has a stator 13 fixed to the inner surface of the closed case 1, and a rotatable rotor 15 provided inside the stator 13.

The compression element 11 has a cylinder 17 whose both ends are open, and the cylinder 17 is rotatably supported at both ends by left and right main bearings 19 and sub bearings 20 fixed to the inner surface of the hermetic case 1. . The bearings 19 and 20 are boss portions 19a and 20 in which the ends of the cylinder 17 are rotatably fitted.
The cylinder 17 includes a and bases 19b and 20b having a diameter larger than those of the bosses 19a and 20a and fixed to the inner surface of the closed case 1. Both ends of the cylinder 17 are hermetically closed.

Inside the cylinder 17, a cylindrical rotating body 21 smaller than the inner diameter of the cylinder 17 is arranged along the axial direction of the cylinder 17. The rotating body 21 is arranged such that its central axis A is eccentric downward in FIG. 2 with respect to the central axis B of the cylinder 17 by a distance e, and a part thereof is in line contact with the inner peripheral surface.

Spindles 21a and 21b each having a small diameter are provided at both ends of the rotary body 21.
a and 21b are bearing holes 19c and 20c formed in the boss portions 19a and 20a of the main bearing 19 and the sub bearing 20, respectively.
It is rotatably inserted into and supported by.

On the right supporting shaft portion 21a of the rotating body 21, there is formed a square column portion 25 having a square cross section which functions as a power transmitting surface for transmitting the rotary power from the cylinder 17 side via the Oldham mechanism 23. There is.

The Oldham mechanism 23 is composed of a ring-shaped Oldham ring 24 and a transmission pin 27, and the inside of the rectangular elongated hole 26 formed in the Oldham ring 24 has the rotating body 2 therein.
1 has a play with respect to the prismatic portion 25, and has a long hole 26
Within the range, the Oldham ring 24 can be slid in a direction orthogonal to the central axis A while making surface contact.

On the outer peripheral surface of the Oldham ring 24,
One ends of the transmission pins 27, 27 are slidably fitted and inserted in a radial direction orthogonal to the longitudinal direction of the elongated hole 26, and the other ends of the transmission pins 27, 27 are bored in the peripheral wall of the cylinder 17. It is fitted and fixed in the fitting hole 29. As a result, the rotating body 21 is secured in the coupled state at a position eccentric to the cylinder 17, and the rotating force of the cylinder 17 is transmitted through the Oldham mechanism 23.
1 is transmitted.

Therefore, when the electric element 9 is actuated, the cylinder 17 rotates integrally with the rotor 15, so that the rotating body 21 eccentrically rotates with respect to the cylinder 17 via the Oldham mechanism 23. At this time, the outer peripheral surface of the rotating body 21,
A relative speed is generated between the inner peripheral surface of the cylinder 17 and the inner peripheral surface of the cylinder 17, and the relative speed changes in a cycle of one rotation so as to rotate in the cylinder 17 and rotate with respect to the cylinder 17. The turning motion is given without any.

On the other hand, a spiral groove 31 is provided on the outer peripheral surface of the rotating body 21, and the spiral groove 31 has the largest pitch P on the suction end side (right side in FIG. 2). , The pitch is set to decrease gradually toward the discharge end side (left side in the drawing).

In the spiral groove 31, the spiral blade 3
3 is fitted so that it can appear and disappear freely by utilizing the elastic force. As a result, each working chamber 35 is formed and the working chamber 35 on the suction end side has the largest volume. Less than,
The volume of each working chamber 35 is set to decrease gradually toward the discharge end side, and the final working chamber 35 on the discharge side is formed in the auxiliary bearing 20 and the discharge hole 3 opened in the closed case 1 is formed.
It is connected and communicates with 7. In addition, each working chamber 35 is arranged along the blade 33 as shown in FIG.
It is an almost crescent-shaped region that extends from the contact part with the inner peripheral surface to the next contact part. The first working chamber 35 on the suction end side is provided with the main passage 3 provided at the shaft end of the rotating body 21.
9 and the suction passage 41 provided in the main bearing 19 so as to connect and communicate with the suction pipe 5 of the refrigeration cycle, and the refrigerant sucked from the suction pipe 5 into the cylinder 17 enters the first working chamber 35. It is being introduced without fail without interruption.

The blade 33 has a large linear expansion coefficient on the side having a smaller dimensional ratio and a side having a larger dimensional ratio with respect to the sectional size ratio of the spiral groove 31 in the groove width direction Pt and the groove depth direction Ph. Has a small linear expansion coefficient, and the blade 3
The product of the dimensional ratio of the three cross sections and the ratio of the linear expansion coefficient is 1 ± 0.2
It is set to the range of.

The dimensions of the groove width Pt and the groove depth Ph of the spiral groove 31 of the blade cross section are such that the coefficient of linear expansion on the smaller side is 20 × 10 ⁻⁵ / ° C. (value in the range of 30 to 150 ° C.). ) A composite material of the following tetrafluoroethylene resin or tetrafluoroethylene perfluoroalkyl vinyl ether copolymer resin.

In FIG. 1 , reference numeral 43 denotes an oil introducing passage provided in the rotating body 21, one end of the oil introducing passage 43 communicates with the spiral groove 31, and the other end thereof is on the suction end side. The main bearing 19 is connected through a communication hole 45 formed in the main bearing 19 to an introduction pipe 49 having a suction port 47 facing the bottom of the closed case 1. Therefore, when the pressure in the closed case 1 rises, the lubricating oil stored in the bottom of the closed case 1 is sent into the groove 31 through the introduction pipe 49, the communication hole 45 and the oil introduction passage 43, so that the blade 31 Lubrication at the time of entry and exit of 33 is ensured.

Next, the operation of the fluid compressor thus constructed will be described.

First, when the electric element 9 is energized, the rotor 15
Rotates, and the cylinder 17 also rotates integrally with the rotor 15. When the cylinder 17 rotates, the rotating body 21 also rotates via the Oldham mechanism 23. Since the rotating body 21 with respect to the cylinder 17 is eccentrically rotated, a relative speed is generated between the outer peripheral surface of the rotating body 21 and the inner peripheral surface of the cylinder 17 facing the rotating body 21, and the relative speed is one cycle of one rotation. The internal rotation of the cylinder 1
On the other hand, the rotating body 21 makes a turning motion without rotation with respect to 7. As a result, the fluid such as the refrigerant taken into the working chamber 35 on the suction end side is compressed while being sent to the working chamber 35 on the discharge end side in a confined state, and discharged from the discharge pipe 7. Like

In this operation, the spiral groove 31 has almost the same clearance Ct = Ch in the groove width direction Pt and the groove depth direction Ph, and moreover, the optimum clearance value is secured, and the stable sealing performance is good. A good coefficient of performance was obtained.

5 to 14 show the results of the first experiment. This experiment is conducted in Examples 1 to 3 and Comparative Examples 1 to 3.
The blade 33 to be a PT with a density of 2.15 g / cm ³ .
A composite of FE resin and φ13 μm glass fiber is used.

Specifically, the fiber length of Example 1 and Comparative Example 1 was 20 μm, the fiber length of Example 2 and Comparative Example 30 was 30 μm, and the fiber length of Example 3 and Comparative Example 3 was 40 μm. Combined, processing procedure is 400-600kg / cm
A square member 51 (base material) of 100 mm square is prepared by pressure molding at a pressure of ² and subsequent firing at 380 ° C. A round bar member 53 is cut from the square member 51 and further machined into a spiral blade 33. At this time, as shown in FIG. 6 to FIG. 7, the orientation of the glass fiber when the blade 33 is formed changes depending on the direction of forming the round bar 53 with respect to the pressure surface F of the pressure molding. That is, the glass fibers are arranged side by side with respect to the pressing direction, and the linear expansion coefficient changes depending on the fiber direction. That is, when the round bar 53 is formed perpendicularly to the pressing surface F of FIG. 6 and the blade 33 is configured, the fibers are oriented in the groove depth direction Bh and the dimension in the groove width direction Dt and the groove depth direction Dh. The change amount has a relationship of Dt> Dh. In addition, the round bar 5 is placed horizontally with respect to the pressing surface F in FIG.
3 is created and the blade 33 is configured, the groove width direction Bt
Since the fibers are oriented in the direction, the dimensional change has a relationship of Dt <Dh.
Furthermore, the degree of orientation (strength of orientation) of the fibers is controlled by the molding pressure and the fiber length. The higher the molding pressure and the longer the fiber length, the stronger the degree of orientation. Therefore, the coefficient of linear expansion is reinforced in the direction in which the degree of orientation of the fiber is strong and becomes smaller,
Utilizing this relationship, as shown in FIG. 5, the dimension (Bt) in the groove width direction of the blade 33 is unified and the dimension (Bh) in the groove depth direction is unified.
The relationship between the ratio of the blade cross-sectional dimension and the reciprocal is different, that is, when the ratio is small, the linear expansion coefficient is large, and when the ratio is large, the linear expansion coefficient is small (groove width direction Dt, groove depth direction D
h). Further, as shown in FIGS. 8 to 13, the set clearances Ct, Ch and the eccentricity α are unified. The purpose of this is because the volume of the working chamber 35 changes depending on the eccentricity α and the dimension of the blade 33 in the groove width direction and the refrigerating capacity is different, so that the influence of the linear expansion coefficient of the present invention is not clear. This configuration is different in the dimension Ph of the blade 33 in the groove depth direction from a1 to a3.
Even if the blade 33, which is called the hanging margin, pops out, the groove 3
It is a dimension that remains 1. This hanging margin prevents the blade 33 from collapsing due to the differential pressure.

Further, Examples 1 to 3 in which the product of the dimensional ratio of the blade cross section and the ratio of the coefficient of linear expansion is set in the range of 1 ± 0.2
The blades 33 of Comparative Examples 1 to 3 in which the product of the dimensional ratio of the blade cross section and the ratio of the linear expansion coefficient were 0.7 or less to 1.3 or more were applied to the spiral type fluid compressor shown in FIG.

In the fluid compressor, "Freon 1" is added to the refrigerant gas.
2 "is used to impart rotation to cylinder 17 at a speed of" 3,000 rpm ". Also, the compressor temperature is 80 ° C.
And The load power and the refrigerating capacity at that time were measured to obtain a coefficient of performance COP (refrigerating capacity / load power).

The measured performance of the fluid compressor is shown in FIG. Figure 14 shows the coefficient of performance COP and Bt / Bh x Dt
The / Dh results are shown in contrast.

That is, "Bt / Bh × Dt of Comparative Example 1"
/ Dh of 0.7 or less to 1.3 or more "
As seen, “Bt / Bh × Dt / Dh of Example 1 is 1 ±
A decrease is recognized for the "range of 0.2". Further, in Comparative Example 2, “Bt / Bh × Dt / Dh is 0.7 or less to 1.
Looking at the COP obtained with “3 or more”, “Bt /
Bh × Dt / Dh is in the range of 1 ± 0.2 ”. Furthermore, “Bt / Bh × Dt / D” of Comparative Example 3
"h is 0.7 or less to 1.3 or more", and "B of Example 3"
"T / Bh x Dt / Dh in a range of 1 ± 0.2" also had similar results. That is, “Bt / Bh ×” in Comparative Examples 1 to 3
When Dt / Dh is 0.7 or less ", the amount of dimensional change Dt <Dh
Because of this relationship, the clearance Ch in the groove depth direction becomes smaller, the groove height direction Bh of the blade 33 contacts the bottoms of the cylinder 17 and the groove 31, and the load power of the fluid compressor increases, resulting in COP It seems to have decreased. Further, in “Bt / Bh × Dt / Dh is 1.3 or more” of Comparative Examples 1 to 3, the dimensional change amount Dt> Dh is satisfied, so
The clearance Ct in the width direction becomes small, and the blade 33
It is considered that the load power of the fluid compressor increased as the resistance to move in and out of the groove 31 increased, resulting in a decrease in COP.

On the other hand, "Bt / Bh × Dt" in Examples 1 to 3
/ Dh is in the range of 1 ± 0.2 "blade 33
It can be seen that, since the clearances Ct and Ch are maintained in an appropriate range, good sealability is secured, and high COP is obtained in both cases. Here, the COP of Example 1 is lower than that of Example 2 because the margin of a1 is small and the blade 33 is tilted due to the pressure difference, and the refrigerant gas leaks. On the contrary, in Example 3, the margin of a3 is large, and the resistance when the blade 33 is pushed into the groove 31 while being elastically deformed is large. Therefore, the load power of the fluid compressor is increased and the COP is lowered. . Furthermore, Comparative Example 1
It can be seen from the comparison of ~ 3 that the COP falls in the order of Comparative Example 1 <Comparative Example 2 <Comparative Example 3. This is because the groove depth direction Bh of the blade 33 becomes larger than the groove depth direction Bt, so that the dimensional change amount (D
It is considered that the absolute value of h) is large, and as a result, the difference in the degree of influence on clearance appears as the result.

15 to 26 show the results of the second experiment.

This experiment was conducted in Examples 4-5 and Comparative Examples 4-5.
The blade 33 to be a PF with a density of 2.12 g / cm ³
The resin A is a composite of pitch-based carbon fibers having a diameter of 15 μm and a length of 100 μm. Specifically, Example 4
15% by weight, 5% by weight in Example 5, 2% by weight in Comparative Example 4 and 1% by weight in Comparative Example 5, and a mold having a nest 55 having spiral grooves as shown in FIG. 57 is mounted on the fixed mold 61 of the injection molding device 59, and the molding temperature is set to 380.
The blade 33 is produced by injection molding under the conditions of ℃ and mold temperature of 200 ℃. At this time, the pitch-based carbon fibers are oriented along the flow of the PFA resin as shown in FIG. Generally, when formed by injection molding, there is no difference in the orientation of the pitch-based carbon fibers, but since the linear expansion coefficient changes depending on the filling amount of the pitch-based carbon fibers, using this relationship, as shown in FIG. Let B be the ratio of the groove width dimension (Bt) of the blade 33 to the groove depth dimension (Bh).
It is unified to t / Bh = 1/1, and the linear expansion coefficient corresponding to the groove width direction Bt and the groove depth direction Bh is also set to Dt / Dh = 1/1. Here, in order to secure the clearances Ct and Ch set as shown in FIGS. 18 to 21, it is necessary to make the size according to the linear expansion coefficient of the blade 33. Further, in order to match other conditions, the eccentricity amount (α1 to α4) and the margin are set to be similar to each other in the size of the blade 33.

Further, in the width direction of the groove 31 and the depth direction of the groove 31 of the blade cross section, the coefficient of linear expansion in the direction of smaller dimension (the same dimension in this embodiment) is set to 20 × 10 ⁻⁵ / ° C. or less. The blades 21 of Examples 4 to 5 and Comparative Examples 4 to ^{5 having a} coefficient of linear expansion exceeding 20 × 10 ⁻⁵ / ° C. were applied to the spiral type fluid compressor shown in FIG.

In the fluid compressor, "Freon 1" is added to the refrigerant gas.
2 "is used to impart rotation to cylinder 17 at a speed of" 3,000 rpm ". Also, the compressor temperature is 80 ° C.
And The load power and the refrigerating capacity at that time were measured to obtain a coefficient of performance COP (refrigerating capacity / load power).

The measured performance of the fluid compressor is shown in FIG.

That is, the coefficient of performance COP was small for the "linear expansion coefficient Dt of 25 x 10 ^-5 / ° C" of Comparative Example 4 and the "linear expansion coefficient Dt of 30 x 10 ^-5 / ° C" of Comparative Example 5. . This is the blade 33 to ensure a set clearance.
It is considered that the volume of the working chamber 35 is inevitably reduced by reducing the cross-sectional shape of, and the refrigerating capacity is reduced. In addition, the sharp decrease in the coefficient of performance COP in Comparative Example 5 is
Since the set clearance is large with respect to the cross-sectional shape of the blade 33, the differential pressure causes the blade 33 to collapse,
This is the result of the deterioration of the sealing ability of the refrigerant gas. That is, if the linear expansion coefficient Dt is large, the shape and size of the blade 33 are reduced in order to secure an appropriate clearance, and the refrigerating capacity is deteriorated. Further, it can be seen that the appropriate clearance range also changes as the shape size of the blade 33 becomes smaller.

On the other hand, in Example 4, the coefficient of linear expansion Dt was 10
× 10 ⁻⁵ / ° C. ”and“ the linear expansion coefficient Dt of Example 5 was 20.
“× 10 ⁻⁵ / ° C.” has a large coefficient of performance COP, and good compressor performance was obtained. However, in Example 4, although the refrigerating capacity was larger than that in Example 5, there was no great difference in COP. This is because the blade 33 is elastically deformed by increasing the cross-sectional shape of the blade 33 and the groove 3
It is considered that the resistance at the time of being pushed into No. 1 became large, and as a result, the load power of the compressor increased and the degree of COP improvement decreased. In this experiment, blade 3
Only the relationship between the linear expansion coefficient and the clearance of No. 3 is shown, and it must be taken into consideration that the COP is also affected by the appearing loss of the blade 33 and the collapse due to the differential pressure.

Therefore, the linear expansion coefficient Dt is 20 × 10 ^-5 /
By setting the temperature to not higher than 0 ° C, a large refrigerating capacity can be obtained while maintaining an appropriate clearance, and a high coefficient of performance COP can be obtained. In addition, although this experiment was performed with a configuration of Dt = Dh, the linear expansion coefficient was 20 × 10 ^{−5 in the} direction of the smaller cross-sectional dimension.
If the temperature is set to / ° C or lower, the linear expansion coefficient in the direction of the larger cross-sectional dimension becomes less than that, assuming that the linear expansion coefficient is inversely related to the cross-sectional ratio verified in Experiment 1. That is, it goes without saying that the above effect can be obtained by defining the linear expansion coefficient only in the direction in which the cross-sectional dimension is small.

Even when the temperature of the compressor is higher than that in the present experiment, the same effect can be obtained by using the blade 33 having a linear expansion coefficient (small) corresponding to the temperature rise. Further, although the PFA resin was used in this experiment, the same effect was obtained also with the PTFE resin, a large refrigerating capacity was obtained while maintaining an appropriate clearance without impairing various characteristics of the blade 33, and a high coefficient of performance COP was obtained. Will be obtained. As the filler, inorganic fibers such as glass fibers and carbon fibers, metal oxides such as ceramic powder and ceramic whiskers, solid lubricants such as bronze, molybdenum, graphite and molybdenum disulfide that impart lubricity, all and There are organic fillers such as partially aromatic polyamide resins, wholly and partially aromatic polyester resins, wholly and partially aromatic polyimide resins, polyether resins, polysulfone resins, etc. It is desirable to use them properly according to the linear expansion coefficient such as the orientation direction.

Further, although the single type blade 33 has been described, it is also possible to apply to a twin type having a pair of left and right.

[0049]

As described above, according to the present invention,
Since the clearances in the groove width direction and the groove depth direction of the blade can be ensured to be almost the same and the optimum clearance can be obtained, the sealability and the coefficient of performance of the blade can be greatly improved. Therefore, the initial performance can be stably maintained over a long period of time, and it is very preferable in terms of assembling.

[Brief description of drawings]

FIG. 1 is a sectional view of a fluid compressor embodying the present invention.

FIG. 2 is a perspective view of a rotating body.

FIG. 3 is a sectional view of the Oldham mechanism.

FIG. 4 is an exploded view showing a compression element.

FIG. 5 is an explanatory diagram showing first experimental conditions of Examples 1 to 3 and Comparative Examples 1 to 3.

FIG. 6 is an explanatory view showing a first molding method of a blade.

FIG. 7 is an explanatory view showing a second molding method of the blade.

FIG. 8 is a sectional view showing a state in which a blade is inserted in a spiral groove.

FIG. 9 is a cross-sectional view showing a state in which the blade protrudes from the groove in the same as above and the margin for engagement is small.

FIG. 10 is a cross-sectional view showing a state where a blade having a large groove depth direction enters the groove.

FIG. 11 is a cross-sectional view showing a state in which the blade of the same as above protrudes from the groove and has a relatively large allowance.

FIG. 12 is a cross-sectional view of a state where a blade having a large groove depth direction enters the groove.

FIG. 13 is a cross-sectional view showing a state in which the blade of the same as above protrudes from the groove and has a large margin of engagement.

FIG. 14 is a characteristic diagram showing the results of performance experiments of the fluid compressor.

FIG. 15 is an explanatory diagram showing second experimental conditions of Examples 4 to 5 and Comparative examples 4 to 5.

FIG. 16 is a schematic explanatory view of an injection molding device that molds a blade.

FIG. 17 is a cutaway perspective view of a portion of a blade formed by injection molding.

FIG. 18 is a cross-sectional view showing a state in which the blade has the maximum size and has entered the groove.

FIG. 19 is a cross-sectional view of the above blade in a state of protruding from the groove.

FIG. 20 is a sectional view showing a state in which the blade has the second largest size and is in the groove.

FIG. 21 is a cross-sectional view of the above blade in a state of protruding from the groove.

FIG. 22 is a cross-sectional view of a state in which the blade has the third size and is in the groove.

FIG. 23 is a cross-sectional view of the same blade as above, protruding from the groove.

FIG. 24 is a cross-sectional view showing a state in which the blade is the smallest and has entered the groove.

FIG. 25 is a cross-sectional view showing a state in which the blade of the above is protruding from the groove.

FIG. 26 is a characteristic diagram showing a second experimental result.

FIG. 27 is a sectional view similar to FIG. 1 showing a conventional example.

FIG. 28 is a perspective view of a rotating body.

FIG. 29 is a sectional view of a spiral groove.

FIG. 30 is a sectional view of the blade.

FIG. 31 is a sectional view showing a clearance of a blade.

FIG. 32 is an explanatory view showing the amount of dimensional change of the blade.

[Explanation of symbols]

9 Drive element (drive means) 17 cylinders 21 rotating body 23 Oldham Organization 31 spiral groove 33 blade 35 working chamber Pt groove width direction Ph Groove depth direction

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F04C 18/344 311 F04C 18/107 F04C 18/22

Claims (2)

(57) [Claims] 1. A and shea cylinder is arranged eccentrically in the axial direction of the cylinder, the rotation of the cylinder relatively pivotable cylindrical with its part in contact with the inner peripheral surface of the cylinder body and an outer circumferential said gradually becomes smaller spiral formed at a pitch grooves to the discharge end from the suction end of the cylinder is provided on the rotating body, of the cylinder with the inserted freely fitted retractable into the groove A spiral blade having an outer peripheral surface that is in close contact with the inner peripheral surface and partitioning the space between the cylinder and the rotating body into a plurality of working chambers, and at the time of turning of the rotating body, the refrigerant that has flowed in from the suction end side. In the fluid compressor that sequentially transfers the fluid to the working chamber on the discharge end side, the blade has a groove width direction of the spiral groove and a cross-sectional dimension ratio in the groove depth direction,
The side with a small dimensional ratio has a large linear expansion coefficient, the side with a large dimensional ratio has a small linear expansion coefficient, and the product of the dimensional ratio of the blade cross section and the linear expansion coefficient is at least 1 ± 0.2. A fluid compressor characterized in that 2. The dimensions of the spiral groove of the blade cross section in the groove width direction and the groove depth direction are such that the coefficient of linear expansion on the smaller side is 2
It is composed of a tetrafluoroethylene resin or a composite material of ethylene tetrafluoride and a perfluoroalkyl vinyl ether copolymer resin having a concentration of 0 × 10 ⁻⁵ / ° C. (value in the range of 30 to 150 ° C.) or less. The described fluid compressor.