JPH01301974A - Fluid compressor - Google Patents

Abstract

PURPOSE:To prevent any leakage so as to attempt enhancement of compression efficiency by forming, alternately in the axial direction of a cylinder, operational chambers contributing to compression and non-operational chambers showing no diret contribution to compression. CONSTITUTION:Two spiral grooves 43, 44 each of which is individually arranged in an uniform pitch but respective ones of them are different from each other in their pitches are provided in a piston 27. Two spiral blades 28, 29 each of which has its own constant pitch are freely detachably inserted in these two grooves 43, so that operation chambers 45 contributing to the compression and non-operational chambers 46 not contributing to compression are formed alternately in the axial direction of a cylinder 26. In addition, two grooves 43, 44 and oil hole 46 communicating to non-operational chamber 46 and a oil supply source are provided inside the piston 27. Both grooves 43, 44 and non-operational chamber 46 are filled with oil and two blades 23, 29 are expanded in the radial directional of the cylinder 26 by means of hydraulic pressure and also they are pressed toward the direction for sandwiching the operational chambers 54.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a helical blade type fluid compressor for compressing refrigerant gas in, for example, a refrigeration cycle.

(Prior Art) A helical blade type fluid compressor is generally constructed as shown in FIG.

That is, this type of fluid compressor 1 has a closed case 2
A cylinder 6 fixed to the rotor 3 is rotated by driving a motor 5 consisting of a rotor 3 and a stator 4 provided inside the cylinder 6.
A piston 7 having eccentricity me with respect to + is pivotally supported. Furthermore, a spiral groove 8 is provided on the outer periphery of the piston 7, the pitch of which gradually decreases from one end side to the other end side.

A continuous spiral blade 9 is fitted into the groove 8, the outer peripheral edge of which touches the inner surface of the cylinder 6. Then, the refrigerant gas in the refrigeration cycle is sucked into the low pressure side of the cylinder 6 from the suction hole 11 to which the suction tube 1o is attached.

Furthermore, such a fluid compressor has a space formed by a spiral blade 9 between the outer periphery of the piston 7 and the inner surface of the cylinder 6 due to the rotation of the cylinder 6;
That is, the gas trapped in the operating chamber 12 is transferred from one end of the piston 7 to the other end. At this time, since the volume of each operating chamber 12 is gradually reduced from the transfer front side 13 to the transfer side 14, the gas taken into the cylinder 6 is gradually compressed as it is transferred. . The transfer side 14 of the cylinder 6 discharges the compressed gas into the sealed case 2. Then, the compressed high-pressure gas discharged into the sealed case 2 is transferred to the discharge tube 1.
It is discharged from the discharge hole 17 to which 6 is attached and returned to the refrigeration cycle.

By the way, in order to increase compression efficiency in this type of fluid compressor 1, it is necessary to improve processing accuracy and assembly accuracy to improve sealing performance. In other words, it was necessary to improve the sealing performance between the blade 9 and the inner circumferential surface of the cylinder 6, and between the blade 9 and the wall surface of the groove 8 to prevent leakage of high-pressure gas. However, when winding the blade 9 around the piston 7, the blade 9 is screwed into the groove 8 whose pitch gradually changes while being elastically deformed. There were limits to processing accuracy and assembly accuracy.

In addition, since the blade 9 is made of a flexible material such as polytetrafluoroethylene (Teflon), the blade 9 may undergo plastic deformation, or so-called settling, due to long-term operation. was there.

Due to these problems, especially the part 2 where the differential pressure is large
For example, leaks tend to occur between adjacent operating chambers on the high pressure side.

(Problem to be solved by the invention) In conventional fluid compressors as mentioned above.

Because the blade was wrapped around the piston while being elastically deformed, there were problems with processing accuracy and assembly accuracy.

In addition, since the blade was made of a flexible material, the blade could become stale if the machine was operated for a long period of time. And by these things.

There was a problem in that it was difficult to obtain sufficient sealing performance and leaks were likely to occur.

An object of the present invention is to provide a fluid compressor that improves the sealing performance between a high-pressure operating chamber and a low-pressure operating chamber to prevent leakage and has high compression efficiency.

[Structure of the invention]

(Means and operations for solving the problems) In order to achieve the above objects, the present invention provides: 1. Two spiral grooves are provided in the piston, each having an equal pitch and different pitches from each other, and each of these two grooves has a The reason is that two helical blades of equal pitch are fitted in and out so that working chambers that contribute to compression and non-working chambers that do not directly contribute to compression are alternately formed in the axial direction of the cylinder. Furthermore, the above 2
Two grooves, an oil hole communicating with the non-operating chamber and an oil supply source are provided, both grooves and the non-operating chamber are filled with oil, and the two blades are operated by hydraulic pressure.

The reason is that the cylinder is expanded in the radial direction and is also pressed in the direction across the working chamber.

By doing so, the present invention is able to wrap one blade around the piston without elastically deforming the blade.

In addition, the present invention applies hydraulic pressure to the three blades.

The reason is that both blades and the inner circumferential surface of the cylinder, and both blades and both grooves are brought into close contact with each other to improve sealing performance.

(Example) An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which reference numeral 20 indicates a hermetic compressor for refrigerant gas used in a refrigeration cycle. This compressor 2o has an electric element 2 inside a sealed case 21.
2 and a compression element 23 are incorporated. Electric element 22
is the stator 24 attached and fixed to the inner wall surface of the sealed case 21.
and a rotor 25 disposed inside the stator 24.

The compression element 23 has a piston 27 eccentrically arranged inside a cylindrical cylinder 26 fixed to the rotor 25, and the piston 27 is rotated at the same rotation speed as the cylinder 26 by a mechanism (not shown).

It is adapted to rotate relative to the inner surface of the cylinder 26.

Further, first and second blades 28 and 29 are wound around the outer circumference of the piston 27, as will be described later. The piston 27 and the cylinder 26 each have bearings mounted on the inner surface of each end wall of the sealed case 21.
0.31. That is, the piston 27 has shaft portions 32 and 33 projecting from both ends thereof, and the shaft portions 32 and 33 are inserted into the bearing hole 34 of the bearing member 30.31.
．． 35 for pivot support.

Further, the cylinder 26 has both end portions connected to bearing members 30.3.
It fits into the bearing circumferential surface portion 36, 37 of No. 1 and is pivotally supported.

As shown in FIG. 1, the central axis of the cylinder 26 (and rotor 25) and the central axis of the piston 27 are offset by e and are eccentric. Namely.

The center axis No. 1 of the cylinder 26 is the rotation center axis l of the piston 27! It is mounted eccentrically by e with respect to 2. Further, the center axis of the cylinder 26 substantially coincides with the rotation center axis No. 1 of the rotor 25.

Further, a suction hole 38 and a discharge hole 39 communicating with the inside of the cylinder 26 are formed in the bearing member 30 on one end side and the bearing member 31 on the other end side.

A suction tube 40 in a refrigeration cycle is connected to the suction hole 38. Further, this suction-side bearing member 30 is provided with an oil suction pipe 41 that communicates the internal space of the sealed case 21 with the bearing hole 34 .

One end of the oil suction pipe 41, that is, the end located within the internal space of the sealed case 21, is filled with lubricating oil (not shown) injected into the sealed case 21.
is inserted inside.

On the other hand, the discharge hole 39 opens into the inside of the sealed case 21, and a discharge tube 42 communicating with the inside of the case is connected to the sealed case 21. That is, the gas to be compressed is taken into the cylinder via this suction tube 40 and the above-mentioned suction hole 38, and is compressed. The compressed gas passes through the discharge hole 39 and is first discharged into the sealed case 21, and then flows out from the discharge tube 41.

Next, the piston 27 and the first cylinder wound around the piston 27 are installed. The second blades 28 and 29 will be explained.

Two spiral grooves 43, 44 for winding both blades 28, 29 around the outer periphery of the piston 27 are formed in succession, as shown in FIG. 3, respectively. The pitch a of the first grooves 43 and the pitch b of the second grooves 44 are equal to each other, and furthermore, the pitch b of the second grooves 44 is somewhat smaller than the pitch a of the first grooves 43. It's getting bigger. Further, here, the number of turns of the second groove 44 is approximately one turn less than the number of turns of the first groove 43. The starting point 43a of the first groove 43 is located approximately at the end on the suction side of the large diameter portion of the piston 27 excluding both shaft portions 32 and 33.

The end point 43b also reaches the discharge side end of the large diameter portion.

Furthermore, the starting point 44a of the second groove 44 is located at the starting point 44a of the first groove 43.
It is located in point contact with the discharge side near the starting point 43a, and the end point 44b reaches the discharge side end of the large diameter portion of the piston 27.

And FIG. 4(a) and FIG. 4(b).

A first blade 28 and a second blade 29 are shown, respectively. The first blade 28 has the same diameter and is wound spirally at a constant pitch a.

Further, the second blade 29 also has the same diameter and is wound helically at the same pitch b. And this second blade 2
The number of turns of the first blade 28 is approximately 1 more than the number of turns of the first blade 28.
There are fewer windings. Furthermore, these two blades 28
．． The material of both 29 is, for example, thin laminated metal, and the cross section of each of the two grooves 43 and 44 is similar to the above-mentioned grooves 43 and 44.
It has a rectangular shape that almost matches the radial shape of.

Both blades 28 and 29 are shaped so that their outer peripheral edges closely contact and roll against the inner surface of the cylinder 26, and the width of each groove 43 and 44 is the same as that of both blades 28 and 29.
．． The thickness is almost the same as that of No. 29.

Furthermore, as shown in FIGS. 1 and 2, the blades 28 and 29 are respectively fitted into the grooves 43 and 44 provided in the piston 27 so as to be able to move in and out. Here, both the blades 28 and 29 are wound around the piston 27 by being screwed from the discharge side to the suction side of the piston 27. At this time, the starting point 29a of the second blade 29
is in contact with the discharge side of the first blade 28, and further.

Both end points 28b, 29b of both blades 28, 29 are.

It is in contact with the disc-shaped member 27B fitted to the shaft portion 33 on the discharge side. This disc-shaped member 27a has a through hole 27b and rotates in synchronization with the piston 27.

As shown in FIGS. 1 and 2, the piston 27 is housed in the cylinder 26, so that the discharge side is partitioned by a first blade 28, and the suction side is partitioned by a second blade 29. Multiple operation chambers 45 divided by
... is formed. In other words, the suction side surfaces 28c of the first blades 28 forming the operating chambers 45 are arranged at equal pitches.

The second blade 29 also forms the operating chamber 45...
The discharge side surfaces 29c... are also arranged at equal pitches. The volume of the plurality of operating chambers 45 is the same as that of the first blade 2.
The difference between the pitch a of the blade 8 and the pitch b of the second blade 29 gradually decreases from the suction side to the discharge side.

Further, non-operating chambers 46, which are not directly involved in fluid compression, are formed between the operating chambers 45.

This non-operating chamber 46 is located at the discharge side 2 of the first blade 28.
8d and the suction side surface 29d of the second blade 29, and is formed between the working chambers 45... and the non-working chambers 46.
... are formed alternately in the axial direction of the cylinder 28. The discharge side surface 28d of the first blade 28 and the suction side surface 29 of the second blade 29, which form the non-operating chambers 46, are also arranged at equal pitches.

Further, inside the piston 27, as shown in FIGS. 2 and 5, an oil hole 47 is provided in the axial direction. The oil hole 47 opens in the end surface 32a of the shaft portion 32 on the suction side and communicates with the bearing hole 34. In other words, oil hole 4
7 is lubricating oil (not shown) via the oil suction pipe 41.
It communicates with the inside of the sealed case 21, which serves as an oil supply source into which oil is injected.

Further, as shown in FIG. 5, the oil hole 47 is connected to the introduction hole 48.
49, the second groove 44 and the non-operating chamber 46 are communicated with each other. That is, the introduction holes 48 and 48 are open to each groove 43 and 44 and the oil hole 47, and the t and other introduction holes 49 are open to the non-operating chamber 46 and the oil hole 47.

Next, the operation of the compressor 20 having the above configuration will be explained.

By activating the electric element 22, the rotor 25 rotates, and the cylinder 26 integrated therewith also rotates once. and,
Due to this rotation of the cylinder 26, the piston 27, which is mounted eccentrically by e with respect to the rotation center axis no. l of the cylinder 26, rotates within the cylinder 26 at the same rotation speed as the cylinder 26, and Transfer tangent.

For this purpose, the spiral blades 28, 29 fitted into the grooves 43, 44 of the piston 27 move in and out of the grooves 43, 44 following the eccentric rotational movement of the cylinder 26. The two blades 28.degree.
The outer Ji4 edge of the cylinder 29 always adheres closely to the inner circumferential surface of the cylinder 26 and follows it smoothly. Thus, the suction side of the first blade 28 and the discharge side of the second blade 29.

and an operating chamber 45 formed by the inner peripheral surface of the cylinder 26.
...Mutual partitioning is ensured.

Each of the partitioned operating chambers 45 has a crescent shape of some kind. In other words, this operating chamber 4
5... can be explained in the circumferential direction.

The partitioned working chamber 45 starts from the position where the cylinder 26 and the piston 27 touch, the gap gradually increases, and then becomes smaller again until it reaches the position where they touch. And one blade 28
．． Due to the difference between the pitches a and b of 29, the operating chamber 45...
The volume decreases as it moves toward the transfer side.

The refrigerant gas flowing into the cylinder 26 from the suction tube 40 through the suction hole 38 enters the operation chamber 45b at the suction side end, and is compressed as it is confined and transferred. This compressed refrigerant gas is discharged into the sealed case 21 through a discharge hole 39 provided in the bearing member 31 and returned to the refrigeration cycle through a single discharge tube 41.

Furthermore, the first groove 43 and the second groove 44 . Oil 50 flows into the non-operating chambers 46 through the oil hole 47, and both the grooves 43, 44 and the non-operating chamber 46 are filled with this oil 50.

And the first blade 28 and the second blade 29
receives hydraulic pressure as shown by arrows 51 and 52 in FIG. 1, and presses its outer peripheral edge against the inner surface of the cylinder 26. That is 1
Both blades 28.29 are pushed out in the radial direction of cylinder 26 and piston 27 by the pressure of oil 50 filled in both grooves 43.44, and thereby both blades 28.2
The outer peripheral edge of the cylinder 26 is in close contact with the inner surface of the cylinder 26 without any gap.

Therefore, the space between the outer peripheral edges of the blades 28 and 29 and the inner surface of the cylinder 26 is completely closed.

This prevents the compressed gas inside the working chambers 45 from leaking from between the outer circumferential edges of the blades 28, 29 and the inner surface of the cylinder 26.

Also, the oil 50 filled in the non-operating chamber 46 causes the first
The discharge side surface 28d of the second blade 28 and the suction side surface 29d of the second blade 29 receive back pressure and the two blades 2
8.29 are each pushed in the direction of sandwiching the operating chamber 45... and.

The suction side surface 28c of the first blade 28 and the discharge side surface 29c of the second blade 29 are connected to both the grooves 43.44.
are pressed against the wall surfaces 43c and 44c, respectively, so that the side surfaces 28C129c are pressed against the wall surfaces 43c and 44c, respectively.
Closely fits 44c without any gaps. Therefore, the suction side 28 c of the first blade 28 and the second blade 29
discharge side surface 29c, and each wall surface 43 of both grooves 43.44.
C244c, and as a result, the compressed gas inside the operating chamber 45... leaks from between the side surfaces 28c, 29c and the wall surfaces 43c, 44C. Never.

Here, the part surrounded by circle A in Fig. 2, that is, the second
If the starting point 29a of the first blade 29 and the discharge side surface 28d of the first blade 28 are joined by a method such as adhesive or welding, the oil 50 will not leak from this joint A.

Here, the introduction holes shown as 48.49 in this embodiment are the first groove 43 and the second groove 44. and non-operating chamber 46...
It is sufficient if the arrangement is such that the oil hole can be filled with the oil 50. That is, the first groove 43 and the oil hole 47. A plurality of introduction holes may be provided between each of the second grooves 44 and the oil holes 47, and a plurality of non-operating chambers 46...
An introduction hole may be provided for each of them. Furthermore, an introduction hole may be formed in one groove on the gas upstream side, that is, in the suction side end of the cylinder 26 and one non-operating chamber 46.

Further, the number of introduction holes may be one, for example, only one introduction hole 48 formed for the second groove 44.

In this case, both the grooves 43, 44 and the non-operating chamber 46...
・In order to ensure that oil 50 is sufficiently supplied to the first
It is possible to set large clearances between the discharge side surface 28d of the blade 28 and the wall surface of the first groove 43, and between the suction side surface 29d of the second blade 29 and the wall surface of the second groove 44.

Note that the oil 50 rises through the oil suction pipe 41 by high pressure gas discharged into the inside of the sealed case 21 and flows into both the grooves 4.
3.44 and the non-operating chamber 46... In other words,
When the compressor 20 is in operation, the inside of the sealed case 21 is filled with discharged high-pressure gas, and the lubricating oil injected into the sealed case 21 is placed under the pressure of the high-pressure gas.

In the fluid compressor having such a configuration, since the pitches of the two grooves 43,44 formed in the piston 27 are equal to each other, machining of each groove 43,44 is easy. In addition, the two spiral blades 28 and 29 are formed at equal pitches.

It can be fitted into both grooves 43 and 44 without being elastically deformed. Therefore, the processing accuracy and assembly accuracy of the piston 27 and both blades 28, 29 are good, and one assembly is easy, which improves productivity. Also, when winding one blade 28 and 29 around the piston 27, the blade 2
8.29 can be screwed in without elastically deforming it.

Metal can be used as the material of the blades 28 and 29. Therefore, even if the operation continues for a long time, the blade 28
．． 29 does not become sagging, and performance deterioration can be prevented.

Also, by using hydraulic pressure, the two blades 28 and 29 are pushed out in the radial direction of the cylinder 26, and the one blade 28 and 29 are expanded in the radial direction of the cylinder 26.
29 in the direction sandwiching each operating chamber 45, the outer circumferential edges of the two blades 28, 29 and the inner circumference of the cylinder 26,
The side surfaces of the blades 28 and 29 are in close contact with the walls of both grooves 43 and 44.

Therefore, the sealing performance between the high-pressure operating chambers 45 and the surrounding low-pressure portions is greatly improved, thereby preventing leakage of high-pressure gas. This increases compression efficiency and improves reliability.

Furthermore, the sealing performance can be improved without increasing processing accuracy or assembly accuracy, so it is inexpensive.

In addition, since the operating chambers 45 and non-operating chambers 46 are formed adjacent to each other, even if overcompression occurs in the operating chamber on the discharge side, for example, the non-operating chambers 46 and The reliability is high because a buffering effect occurs between the two and the pressure is reduced.

〔Effect of the invention〕

As explained above, the present invention provides a piston with two spiral grooves each having an equal pitch and different pitches from each other, and allowing two spiral blades each having an equal pitch to move in and out of these two grooves. an operating chamber that is fitted into the chamber and contributes to compression;
Non-working chambers that do not directly contribute to compression are formed alternately in the axial direction of the cylinder, and an oil hole is provided inside the piston that communicates with the two grooves, the non-working chamber, and an oil supply source.

Both the grooves and the non-operating chamber are filled with oil, and the two blades are pushed apart in the radial direction of the cylinder and pushed in the direction across the operating chamber by hydraulic pressure.

Therefore, the present invention has the effect that both blades can be wound around a piston without being elastically deformed, which facilitates processing and assembly and improves productivity.

Furthermore, the present invention has the effect that sealing performance can be improved even if processing accuracy and assembly accuracy remain unchanged, thereby reducing leakage and improving compression efficiency.

[Brief explanation of the drawing]

Figures 1 to 5 show one embodiment of the present invention.
The figure is a side sectional view of the compressor, Figure 2 is a partial side sectional view showing a state in which a piston wrapped with blades is arranged in a cylinder, Figure 3 is a side view of the piston, Figures 4 (a) and Fourth
Figure (b) is a side view showing the first and second blades, Figure 5 is an enlarged side sectional view showing the oil hole and its action, and Figure 6 is a side view showing the first and second blades.
The figure is a side sectional view showing a conventional example. 20...Fluid compressor, 26...Cylinder, 27...
・Piston, 28.29...Blade, 43.44・
··groove. 45... Operating chamber, 46... Non-operating chamber, 47... Oil hole. 50...Oil. Applicant's agent Patent attorney Takehiko Suzue Figure 3 (a) (b) W&4 Figure 5 Figure 6

Claims (1)

[Claims] A piston with a spiral blade wound around a spiral groove provided on its outer periphery is placed inside the cylinder, and the fluid taken in between the blades is discharged in the axial direction of the cylinder by the relative movement between the piston and the cylinder. In a fluid compressor that compresses fluid while transferring it to the side, the piston is provided with two spiral grooves each having an equal pitch and different pitches from each other,
Two spiral blades each having an equal pitch are fitted in and out of these two grooves, and working chambers that contribute to compression and non-working chambers that do not directly contribute to compression are alternately formed in the axial direction of the cylinder. An oil hole communicating with the two grooves, the non-operating chamber, and an oil supply source is provided inside the piston, and both the grooves and the non-operating chamber are filled with oil, and the two blades are moved by hydraulic pressure to the diameter of the cylinder. A fluid compressor characterized in that it expands in the direction and is pressed in the direction to sandwich the operating chamber.