JPH02201081A - Fluid compressor - Google Patents

Abstract

PURPOSE:To reduce deformative stresses in a blade of a fluid compressor in such a construction, that a piston with a spiral blade fitted in a spiral groove reducing its pitch from the suction side toward the discharge gradually is fitted in a cylinder, by specifying the relationship between the inner dia. of cylinder and the effective length of piston. CONSTITUTION:A stator 15 of an electromotive element 13 is fixed to the inner surface of side peripheries of an enclosed case 12, and a cylinder 17 is fitted on a rotor 16 arranged inside thereof, therein the two ends are supported rotatably by bearings 18, 19, which are provided with a suction hole 26 and a discharge hole 28, respectively. A piston 20 is fitted in this cylinder 17 eccentrically in an amount (e). This piston 20 is provided at its periphery with a spiral groove 23 reducing its pitch gradually from the suction toward discharge side, and a spiral blade 24 is fitted in this groove 23 in such a way that it can advance and retreat freely. Therein the relation as expressed by D>=L shall be met, where D is inner dia. of cylinder 17, and L is effective length of piston 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fluid compressor that compresses refrigerant gas in, for example, a refrigeration cycle.

(Prior Art) Compressors of various types, such as a reciprocating type and a rotary type, are conventionally known. However, in these types of compressors, the drive section such as a crankshaft that transmits rotational force to the compressor section and the structure of the compression section are complicated, and the number of parts is large. Furthermore, in order to increase compression efficiency in such conventional compressors, it is necessary to install a check valve on the discharge side, but since the pressure difference on both sides of this check valve is very large, Gas easily leaks and compression efficiency is low. In order to solve these problems, it is necessary to improve the dimensional accuracy and assembly accuracy of each component, which increases manufacturing costs.

Also, US Pat. No. 2,401,189 discloses a so-called screw type pump. This type of pump has a cylindrical rotating body inside the sleeve.
A spiral groove is formed on the outer peripheral surface of this rotating body, and a spiral blade is slidably fitted into the groove. By rotating the rotating body, between the outer peripheral surface of the rotating body and the inner peripheral surface of the sleeve, the fluid trapped in the two adjacent winding sections of the blade is transferred from one end of the sleeve to the other end. It is designed to be transported. However, the above-mentioned screw type pump simply transfers fluid from one end to the other, and does not have the function of compressing fluid.

(Problems to be Solved by the Invention) As mentioned above, the conventional fluid compressor has a complicated structure and a large number of parts, and it is necessary to provide a check valve at the boundary between the high pressure side and the low pressure side. However, gas sometimes leaked from this check valve, resulting in low compression efficiency.

Further, a type of screw pump in which a rotating body wrapped with spiral blades is disposed within a sleeve simply transports fluid and does not have a compression effect.

For these reasons, the applicant's earlier application (Patent Application No. 63)
-170692) has been proposed. As shown in Fig. 6, a cylinder 2 having a suction side and a discharge side is disposed inside a sealed case 1, and the cylinder 2 is arranged along the axial direction of the cylinder 2 and eccentrically (e). A piston (rotating body) 3 is provided, and the piston 3 is
The cylinder 2 and piston 3 are made to rotate relative to each other with a portion of the piston 3 in contact with the inner circumferential surface of the cylinder 2. Further, a spiral groove 4 is provided on the outer periphery of the piston 3, and a spiral blade 5 is fitted into the spiral groove 4 so as to be able to move in and out.

By bringing the outer circumferential surface of the blade 5 into contact with the inner circumferential surface of the cylinder 2, the blade 5 is used to open a space between the inner circumferential surface of the cylinder 2 and the outer circumferential surface of the piston 3 into a plurality of working chambers 6. The cylinder 2 and the piston 3 are rotated relatively while dividing the fluid into the working chamber 6 from the suction side of the cylinder 2, and the working chamber 6 is sequentially transferred to the discharge side of the cylinder 2. It constitutes a compression section that compresses fluid during the process.

In this structure, when the inner diameter of the cylinder 2 is D1 and the effective length of the piston 3 is L, the relationship between the two lengths is DSL.

With this structure, a large displacement volume cannot be obtained, and in order to increase the displacement volume, it is necessary to increase the eccentricity between the cylinder 2 and the piston 3 or to increase the pitch of the grooves 4.

However, if the eccentricity fake is increased or the pitch of the grooves 4 is increased, the stress and friction loss due to the deformation of the blade 5 will increase, and the results cannot necessarily be expected to be sufficient in terms of compression performance, durability, etc. There will be no.

The present invention has been made with a focus on the two-pronged problem, and its purpose is to provide relatively simple means, high efficiency,
An object of the present invention is to provide a fluid compressor that has high performance and improved durability.

[Structure of the invention]

(Means and Actions for Solving the Problems) In order to achieve the above object, the present invention provides a method which is arranged in a cylinder along the axial direction of the cylinder and eccentrically so that a part of its circumferential surface contacts the inner circumferential surface of the cylinder. A cylindrical rotating body that is rotatable relative to the L cylinder is arranged in a state in which a spiral groove is provided on the outer periphery of the rotating body, and the groove can freely move in and out in a substantially radial direction of the rotating body. A spiral blade having an outer circumferential surface that is in close contact with the inner circumferential surface of the cylinder is fitted, and the space between the inner circumferential surface of the cylinder and the outer circumferential surface of the rotating body is partitioned into a plurality of sections by the blade. , a working chamber for fluid compression whose volume gradually decreases from one end side to the other end is formed by relatively rotating the cylinder and the rotating body; In a fluid compressor provided with a driving means for relative rotation, the relationship between the inner diameter of the cylinder and the effective length of the piston satisfies D≧L.

Since the relationship between the inner diameter of the cylinder of the fluid compressor and the effective length of the piston is D≧L, the displaced volume of the fluid compressor can be increased by increasing the eccentricity of the piston with respect to the cylinder. However, the deformation stress of the blade can be reduced. Therefore, it is possible to reduce loss due to stress caused by deformation of the blades, and provide a fluid compressor that is efficient, high performance, and durable.

By the way, in the fluid compressor of the above type, when the eccentricity We of the cylinder and piston is changed, the relationship between the inner diameter of the cylinder and the displacement volume V becomes as shown in FIG. In other words, if the inner diameter of the cylinder is increased without changing the effective length of the piston and the lead of the blade, the displacement volume V will increase in proportion. Moreover, the greater the eccentricity ff1e, the greater the tendency.

Furthermore, without changing the effective length of the piston and the lead of the blade, FIG. 3 shows the relationship between the inner diameter of the cylinder and the deformation stress σ of the blade at various eccentricities e. That is,
In this case, as the inner diameter of the cylinder increases,
The deformation stress σ of the blade increases.

Further, in each case where the eccentricity is changed without changing the effective length of the piston and the inner diameter of the cylinder, the relationship between the pitch of the groove and the deformation stress σ of the blade is as shown in FIG. 4. That is, as the pitch of the grooves increases, the deformation stress σ of the blade increases.

Therefore, as shown in Fig. 2, from the relationship between the inner diameter of the cylinder and the excluded volume V, in order to increase the excluded volume V, it is necessary to increase the eccentricity Jle or increase the inner diameter of the cylinder. is possible.

On the other hand, as shown in Fig. 3, when considering the relationship between the inner diameter of the cylinder and the deformation stress σ of the blade in terms of the amount of eccentricity e, for the same inner diameter of the cylinder, the larger the amount of eccentricity e, the more the blade deforms. It can be seen that the stress σ increases. In other words,
If an attempt is made to increase the displacement volume by increasing the eccentricity e, the deformation stress σ of the blade becomes considerably large.

Furthermore, if the pitch of the grooves is increased, the deformation stress σ of the blade will be increased due to the relationship shown in FIG.

From the above two results, it has been found that in order to increase the displacement volume V of this type of fluid compressor while decreasing the deformation stress σ of the blades, it is better to increase the inner diameter of the cylinder.

Therefore, in the present invention, as described above, the relationship between the inner diameter of the cylinder and the effective length of the piston is set to D≧L.

(Embodiment) FIG. 1 shows a first embodiment of the present invention. 1st
The figure shows a hermetic fluid compressor 11 for refrigerant gas used in a refrigeration cycle. The fluid compressor 11 includes a closed case 12, an electric element 13 as a driving means disposed inside the closed case 12, and a compression element 14. The electric element 13 is arranged in a sealed case 1
a substantially annular stator 15 fixed to the side peripheral inner surface of 2;
An annular rotor 16 provided inside this stator 15
This drives the compression element 14 as described later.

The compression element 14 has a vertically placed cylinder 17;
The rotor 16 is coaxially fixed to the outer peripheral surface of the cylinder 17. The upper and lower ends of the cylinder 17 each have bearings 18.1 fixed to the inner surface of the sealed case 12.
It is rotatably supported by 9. Also, cylinder 1
The openings at the upper and lower ends of 7 are hermetically closed by bearings 18 and 19.

Furthermore, in the cylinder 17, this cylinder 17
A piston 20 as a cylindrical rotating body having an outer diameter smaller than the inner diameter of the cylinder 17 is arranged in parallel along the axial direction of the cylinder 17 . This piston 20 is arranged such that its central axis A is eccentric to the central axis B of the cylinder 17 by a distance e.

A part of the outer peripheral surface of this piston 20 is part of the cylinder 1.
A part of the inner circumferential surface of 7 is always in contact. The upper and lower ends of the piston 20 are rotatably supported by the bearings 18 and 19, respectively.

Further, as shown in FIG. 1, an engagement groove 21 is formed in a part of the outer periphery of one end of the piston 20.
1 includes a drive bottle 22 protruding from the inner circumferential surface of the cylinder 7.
is inserted into the cylinder 17 so that it can move forward and backward along the radial direction. Therefore, the electric element 13 is energized and the cylinder 1 is
7 is rotated integrally with the rotor 16, the cylinder 1
7 is transmitted to the piston 20 via the drive pin 22. Then, the piston 20 internally rotates within the cylinder 17 with a portion of its circumference contacting the inner surface of the cylinder 17. Note that as a means for transmitting the rotational force of the cylinder 17 to the piston 20, an Oldham joint or the like may be used.

Further, the piston 20 is provided on the outer peripheral surface of the piston 20.
A spiral groove 23 is formed that extends to both ends. The pitch of this spiral groove 23 is gradually reduced from the bottom to the top in FIG. 1, that is, from the suction side to the discharge side. Further, the width of the groove 23 may be formed to gradually increase from the suction side to the discharge side, but in this embodiment, it is formed with the same width over the entire length. The width of the partition between adjacent grooves gradually decreases from the suction side to the discharge side.

Further, the depth of tJ23 is formed to be equal over its entire length.

A spiral blade 24 is fitted into the groove 23 thus formed. This blade 24 is made of, for example, a fluororesin material and has appropriate elasticity. The thickness of this blade 24 is formed to match the width of the spiral groove 23 into which it is fitted.

Further, the height of the blade 24 is formed to be equal over its entire length. Each part of the blade 24 has a groove 23.
The piston 20 can freely move forward and backward along the radial direction of the piston 20 . The outer circumferential surface of the blade 24 slides on the inner circumferential surface of the cylinder 17 while being in contact with the inner circumferential surface of the cylinder 17 . The blade 24 is attached to the spiral 123 by screwing the blade 24 using its elasticity.

In this compression element 14, the space between the inner peripheral surface of the cylinder 17 and the outer peripheral surface of the piston 20 is partitioned into a plurality of spaces by the blade 24, and each space defines a working chamber 25 for fluid compression. formed respectively. In this way, each working chamber 25 is separated and partitioned between two adjacent winding portions of the blade 24, and when the shape of this space is viewed from the axial direction of the cylinder 17, the piston 20 extends along the blade 24. The cylinder 17 has a substantially crescent shape extending from the contact point with the inner circumferential surface of the cylinder 17 to the next contact point.

Further, the cylinder 17 and the piston 20 are attached to the bearing 18.
A suction hole 26 communicating with the suction side end of the space formed between the two is formed. A refrigerant gas suction tube 27 is connected to this suction hole 26 . However,
The refrigerant gas flows through its suction tube 27 and suction hole 2.
6 into the above-mentioned working chamber 15 from the suction side.

Further, a discharge hole 28 is formed in the other bearing 19 . One end of the discharge hole 28 is open facing the discharge side end surface of the piston 20 and communicates with the working chamber 25 . The other end of the discharge hole 28 opens into the inside of the sealed case 12.

On the other hand, a plurality of oil pump chambers 29 are formed in a space within the groove 23 defined by the blade 24 and the groove 23 into which the blade 24 is fitted. The space forming this oil bomb chamber 29 also has a nearly crescent shape extending from the contact point at one end to the next contact point between the bottom peripheral surface of the groove 23 and the inner peripheral surface of the blade 24. The volume of each oil pump chamber 29 is equal from the suction side to the discharge side because the width of the blade 24 is equal as described above.The cylinder 17 and the piston 20
Due to the relative rotation of , it moves from the suction side to the discharge side,
As will be described later, oil is sucked in and supplied to the parts of the operating members that come into sliding contact with each other.

As shown in FIG. 1, an oil suction hole 30 is formed at the suction side end of the piston 20 along its axial center, and one end of the oil suction hole 30 passes through a through hole 31 formed in the bearing 18 to the sealed case 12. It communicates with the bottom of the. Lubricating oil 32 is stored at the bottom of the closed case 12.

Note that, as shown in FIG. 1, a discharge tube 33 is connected to the closed case 12 and communicates with the inside thereof.

Further, in the compression element 14 configured as described above, the relationship between the inner diameter of the cylinder 17 and the effective length of the piston 20 is made such that D≧L.

Next, the operation of the fluid compressor 11 configured as described above will be explained. First, when the electric element 13 is energized, the rotor 16 rotates, and the cylinder 17 is integrated with the rotor 16.
It also rotates. Each part of the blade 24 is pushed into the groove 23 as it approaches the contact area between the outer circumferential surface of the piston 20 and the inner circumferential surface of the cylinder 17, and moves in the direction of protruding from the groove 23 as it moves away from the contact area. do.

At the same time, the piston 20 is rotated with a portion of its outer circumferential surface in contact with the inner circumferential surface of the cylinder 17 . Further, a portion of the bottom outer circumferential surface of the groove 23 of the piston 20 is also rotated while being in contact with the inner circumferential surface of the blade 24 on the same side. Such relative rotational movement between the cylinder 17 and the piston 20 is ensured by a regulating means consisting of the drive pin 22 and the engagement groove 21. Further, thereby, the blade 24 also rotates together with the piston 20.

Between the inner circumferential surface of the cylinder 17 and the outer circumferential surface of the piston 20, there is a working chamber 25, which is a crescent-shaped space when viewed from the axial direction of the cylinder 17, between each winding of the blade 24. It is formed.

The working chamber 25 moves from the suction side at one end to the discharge side at the other end as the cylinder 17 and piston 20 rotate relative to each other while maintaining a closed space. As a result, a suction action occurs, which causes the working chamber 2 on the suction side to
Refrigerant gas (not shown) from the refrigeration cycle is sucked into the refrigeration cycle 5 through the suction tube 27 and the suction hole 26 . This refrigerant gas is sequentially taken into the newly formed working chambers 25 from the suction side, and is sequentially transferred to the discharge side by each of the working chambers 25. Since the volume of each working chamber 25 gradually decreases from the suction side to the discharge side as described above, the refrigerant gas is gradually compressed. The refrigerant gas compressed by being transferred to the discharge side is discharged into the space of the sealed case 12 from the discharge hole 28 formed in the bearing 19 on the discharge side, and is further returned into the refrigeration cycle through the discharge tube 33. It will be done.

On the other hand, an oil pump chamber 29 is formed in the space defined by the blade 24 and the groove 23 into which it is fitted. Oil 32 in 12 is taken in. In addition, due to the discharge pressure of the refrigerant, the closed case 12
Since the pressure inside increases, oil 32 is introduced into the oil pump chamber 29 due to this pressurizing action. And this oil 3
2 is supplied between the blade 24 and the 823 through which it moves in and out, and between the cylinder 17 and the piston 20, during the operation of the compression element 14, to perform a lubricating action therebetween. Moreover, it not only smoothes the relative movement between each member, but also acts as a seal between each member. In particular, working chamber 2
5. Prevent gas leakage between the two.

The fluid compressor 11 configured as described above has a relationship between the inner diameter of the cylinder 17 and the effective length of the piston 20 as D.
≧L. Therefore, even if the displacement e of the fluid compressor 11 is increased by increasing the eccentricity e of the piston 20 with respect to the cylinder 17, the deformation stress σ of the blade 24
can be made smaller. Therefore, loss due to stress caused by deformation of the blades 24 can be reduced, and the fluid compressor 11 can be constructed with good compression efficiency and durability.

Further, according to the configuration of the above embodiment, the refrigerant gas is supplied to the working chamber 2.
Since the gas is transferred and compressed while being confined within the fluid compressor, the gas can be efficiently compressed even if a discharge valve is not provided on the discharge side of the fluid compressor.

Furthermore, since the discharge valve can be omitted, the configuration of the fluid compressor can be simplified and the number of parts can be reduced. Further, since the rotor 16 of the electric element 13 is supported by the cylinder 17 of the compression element 14, there is no need to provide a dedicated rotating shaft, bearing, etc. for supporting the rotor 16. Therefore, the configuration of the fluid compressor can be further simplified and the number of parts can be reduced.

Furthermore, since the spiral blade 24 is made of a fluororesin material with sufficient elasticity, no unreasonable deformation stress is generated even when it moves in and out of the L2 spiral groove 23.
The blade 24 smoothly moves in and out of the groove 23. In other words,
Due to its flexibility, the blade 24 moves in and out of the groove 23 according to the spiral shape, so that, for example, no local deformation force is applied to the blade 24, and the blade 24
4 smoothly enters and exits the groove 23. Further, since the blade 24 made of fluororesin material undergoes sufficient thermal expansion when placed in a high-pressure environment, the gap between the groove 23 and the blade 24 fitted therein is filled and reduced. . Therefore, gas leakage is reduced and performance is improved.

The blade 24 made of fluororesin material does not wear out even when sliding on the groove 23, and even when placed in a high-temperature environment due to an increase in pressure, or exposed to a refrigerant, its properties are resistant to wear. is not easily deteriorated. This greatly improves compressor performance and reliability. Furthermore, the blade 24
When fitting into the groove 23 formed with a variable pitch,
Since the blade 24 can be screwed into the groove 23 while being elastically deformed, the blade 24 can be easily wound around the piston 20.

Furthermore, while the fluid compressor 11 is in operation, the pressure of the oil in the oil pump chamber 26 is applied to the blades 24 in the radial direction from the inner circumferential side, so the blades 24 are constantly pressed toward the inner circumferential surface of the cylinder 17. Therefore, the blade 24 rotates with its outer peripheral surface always in close contact with the inner peripheral surface of the cylinder 17. Therefore, adjacent working chambers 25 can be reliably partitioned off. Moreover, since the blade 24 is pressed toward the inner circumferential surface of the cylinder 17 in this way, even if the manufacturing precision of the parts, such as the perpendicularity of the blade 24, is not very high, the blade 24 is pressed against the inner circumferential surface of the cylinder 17. It follows and moves smoothly in the groove 23 along the radial direction of the cylinder 17. Therefore, manufacturing and assembly of parts can be easily performed.

Further, the cylinder 17 and the piston 20 are in contact with each other while being rotated in the same direction. For this reason,
The friction between these members is relatively small and each can rotate smoothly, resulting in less vibration and noise.

FIG. 5 shows a second embodiment of the invention. In this embodiment, an outer rotor electric motor is used as the electric element 13 as a driving means. Moreover, this electric element 13 is arranged vertically.

That is, the rotor 16 provided around the stator 15
A piston 20 is attached to the outer periphery of the cylinder 17, and the cylinder 17 is fixed to the inner circumferential surface of the side of the sealed case 12. The suction side and the discharge side of the compression element 14 are directly open to the inside of the sealed case 12. That is, the inside of the sealed case 12 has a suction side protrusion 35 with the compression element 14 in between.
and a discharge side space 36. A suction tube 27 is connected to the suction side protrusion 35, and a discharge tube 33 is connected to the discharge side space 36.

Further, the relationship between the inner diameter of the cylinder 17 and the effective length of the piston 20 is D≧L. Therefore, even if the displacement volume of the fluid compressor 11 is increased by increasing the eccentricity me of the piston 2o with respect to the cylinder 17, the blade 2
The deformation stress σ of No. 4 can be reduced. For this reason, blade 2
It is possible to construct a fluid compressor 1 which has good compression efficiency and durability by reducing losses due to stress and the like due to deformation of the fluid compressor 1.

Further, the other configurations and effects of this embodiment are similar to those of the first embodiment.

Note that the present invention is not limited to the above embodiments. Furthermore, the fluid compressor of the present invention is applicable not only to refrigeration cycles but also to other compressors.

C Effects of the Invention As explained above, the fluid compressor of the present invention has a relationship between the inner diameter of the cylinder and the effective length of the piston such that D≧L, but the eccentricity of the piston with respect to the cylinder is Even if you increase the displacement volume of the fluid compressor by increasing the
The deformation stress of the blade can be reduced. therefore,
It is possible to reduce loss due to stress due to blade deformation, and provide an efficient, high-performance, and durable fluid compressor.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing the entire fluid compressor according to the first embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the cylinder inner diameter and the excluded volume V, and FIG. 3 is a diagram showing the relationship between the cylinder inner diameter and the excluded volume V. FIG. 4 is a diagram showing the relationship between groove pitch and deformation stress σ, and FIG. 5 is a diagram showing the entire fluid compressor showing the second embodiment of the present invention. FIG. 6 is a vertical side view of a fluid compressor of an advanced type. 11...Fluid compressor, 13...Electric element, 17...
・Cylinder, 20... Piston, 23... Spiral groove, 24... Blade, 25... Compression chamber, D...
Cylinder, L...effective length of the piston. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A cylinder, and a rotating cylindrical cylinder arranged eccentrically within the cylinder along the axial direction of the cylinder and capable of rotating relative to the cylinder with a part of its circumferential surface in contact with the inner circumferential surface of the cylinder. a spiral groove provided on the outer periphery of the rotary body; and a spiral groove that is fitted into the groove in a substantially radial direction of the rotary body so as to be freely removable and has an outer circumferential surface that is in close contact with the inner circumferential surface of the cylinder. a shaped blade, the blade partitions a space between the inner circumferential surface of the cylinder and the outer circumferential surface of the rotary body into a plurality of sections, and one end is formed by relatively rotating the cylinder and the rotary body. A fluid compressor configured to include a fluid compression working chamber whose volume gradually decreases as it moves from one end to the other end, and a drive means for relatively rotating the cylinder and the rotating body. The inner diameter D and the effective length L of the piston
A fluid compressor characterized in that the relationship D≧L.