JPH0463993A - Fluid compressor - Google Patents

Abstract

PURPOSE:To prevent generation of breakage of a blade and increase discharge capacity by connecting the nearest helical part of a blade and a groove to the suction side to a straight part at the middle part of the curved part. CONSTITUTION:In a fluid compressor 1, a helical groove 19 is formed on the outer circumferential face of a rotary rod 11, and a helical blade 21 is fitted into the groove 19. The nearest helical part of the blade 21 and the groove 19 to the suction side is connected to a straight part at the middle part of the curved part. Hereby, because torsion of the blade 21 is mitigated, generation of breakage of the blade 21 is prevented and the discharge capacity can be increased.

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 a refrigeration cycle, for example, and particularly relates to a fluid compressor (hereinafter referred to as a fluid compressor) equipped with spiral blades. (simply referred to as a compressor).

(Prior Art) Various types of compressors, such as a reciprocating type and a rotary type, have been known so far. However, in these 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 conventional compressors, it is necessary to provide a check valve on the discharge side of the compressor in order to increase compression efficiency. However, the pressure difference between both sides of this check valve is very large, and gas tends to leak from the check valve. Therefore, compression efficiency is low. In order to solve such problems, it is necessary to improve the dimensional accuracy and assembly accuracy of each component, which results in higher manufacturing costs.

In recent years, fluid compressors equipped with spiral blades have been provided to solve the above problems. FIG. 12 shows the main parts of a conventional spiral blade type fluid compressor, which includes a cylinder 101 and an eccentric arrangement (e in the figure indicates the amount of eccentricity) inside the cylinder 101.
The rotating body 102 includes a rotating body 102 that rotates relative to the cylinder 101 (eccentric rotational movement), and a blade 104 inserted into a groove 103 formed in a spiral shape on the outer surface of the rotating body 102. The blade 104 slides in and out of the groove 103 in the depth direction thereof as the rotating body 102 rotates relative to the cylinder 101.

Both ends of the cylinder 101 and the rotating body 102 are
Each bearing 10 is rotatably supported by bearings 105 and 106.
5.106 has a suction port 107 and a discharge port 10, respectively.
8 is provided. The pitch of the grooves 103 gradually narrows from the suction port 107 toward the discharge port 108.

Therefore, when the cylinder 101 and the rotating body 102 are rotated relative to each other, the cylinder 101
The fluid to be compressed, such as gas, sucked into the space between the rotating body 102 and the rotating body 102 is compressed. That is, the space is moved toward the discharge port 108 as the rotating body 102 rotates with respect to the cylinder 101, but since the pitch of the grooves 103 gradually becomes smaller, the volume of the space partitioned by the blades 104 decreases. is gradually becoming smaller. therefore,
The compressed fluid that has entered the space is gradually compressed and finally discharged from the discharge port 108.

In the conventional compressor configured as described above, in order to increase the suction capacity of the fluid to be compressed, the characteristics of the shape of the blade 104a that partitions the first working chamber closest to the suction side are shown in FIG. It was configured as shown. In the figure,
The horizontal axis indicates the rotation angle during one rotation of the rotating body 102, and the vertical axis indicates the distance in the axial direction from the suction end of the blade 104a at each rotation angle. That is, the curve on the suction end side of the blade 104a is convex downward, and the blade 104a
is convex toward the discharge side. On the other hand, blade 10
The curve M on the discharge side of 4a is convex upward, and the blade 104a is convex toward the suction side.

Blade 104a and this blade 104 as described above.
By setting the shape of the groove 103 in the portion where a fits, the volume of the suction side portion of the first working chamber can be increased, and the suction capacity can be increased. As a result, the discharge capacity of the compressor can also be increased. However, due to the curve of the blade 104a, the twist of the blade 104a becomes large at the connection part of M, which causes the blade to break.

(Problem to be Solved by the Invention) As described above, in conventional compressors, in order to increase the suction capacity, the suction side portion of the blade that partitions the first working chamber closest to the suction side is It had a convex shape toward the side, and the discharge side part had a convex shape toward the suction side. As a result, the twist of the blade becomes large at the connection point, and the blade tends to break at this point.

The present invention has been made in view of the above points, and an object of the present invention is to provide a fluid compressor that can increase the discharge capacity while preventing the occurrence of blade damage.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cylinder that sucks in compressed fluid from one end and discharges it from the other end, and a a cylindrical rotating body that is provided on the outer circumferential surface of the rotating body and supported so as to be rotatable relative to the cylinder with a part of the outer circumferential surface being in contact with the inner circumferential surface of the cylinder; a spiral groove formed at a pitch that gradually decreases from the suction end side to the discharge end side of the cylinder; a spiral blade having an outer circumferential surface in close contact with the inner circumferential surface of the cylinder and dividing a space between the inner circumferential surface of the cylinder and the outer circumferential surface of the rotary body into a plurality of working chambers; A fluid compressor comprising a driving means that rotates in synchronization with the cylinder and sequentially transfers the compressed body flowing into the working chamber from the suction end side of the cylinder to the working chamber on the discharge side of the cylinder. The shapes of the blades and grooves that partition the working chamber closest to the suction side among the working chambers are shown with the horizontal axis representing the blade position angle and the vertical axis representing the axial distance from the suction side. The groove curve is characterized by having a concave shape on the suction side, a convex shape toward the discharge side, a convex shape on the discharge side, and a straight connecting portion.

(Function) According to the above configuration, the helical shape of the blade and groove closest to the suction side is connected at the straight part in the middle of the curved part, so the twisting of the blade becomes gentle and damage is prevented. Thus, the discharge capacity can be increased.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 11.

FIG. 2 shows an embodiment in which the present invention is applied to a hermetic compressor for compressing refrigerant in a refrigeration cycle.

The compressor 1 includes a closed case 2, and a motor section 3 and a compression section 4, which are drive means, arranged inside the case 2. The electric motor section 3 has a substantially annular stator 5 fixed to the inner surface of the case 2 and an annular rotor 6 provided inside the stator 5.

The compression section 4 has a cylinder 7, and a rotor 6 is coaxially fixed to the outer peripheral surface of the cylinder.

Both ends of the cylinder 7 are rotatably supported by bearings 8 and 9 fixed to the inner surface of the case 2, respectively, and are hermetically closed. In particular, the right end of cylinder 7,
That is, the suction side end is rotatably supported by the bearing 8, and the left end of the cylinder, that is, the discharge side end is rotatably supported by the bearing 9. The bearings 8 and 9 have boss parts 3a and 9a rotatably inserted into the end of the cylinder 7, a boss part 8a,
A base 8b having a larger diameter than 9a and fixed to the inner surface of the case 2
, 9b, respectively. Therefore, cylinder 7
A rotor 6 fixed thereto is supported coaxially with the stator 5 by bearings 8 and 9.

Inside the cylinder 7 , a rotating rod 11 as a cylindrical rotating body having a smaller diameter than the inner diameter of the cylinder 7 is disposed along the axial direction of the cylinder 2 . The rod 11 is made of metal such as iron. The rod 11 has its central axis A eccentrically positioned by a distance e with respect to the central axis B of the cylinder 7, and a portion of its outer circumferential surface is in line contact with the inner circumferential surface of the cylinder.

A support shaft 12a is provided at both ends of the rotating rod 11.

12b are provided in a protruding manner. These support shafts 1
2a and 12b are rotatably inserted and supported in bearing holes 8c and 9c formed in the bearing 8.9, respectively.

As shown in FIGS. 2 to 5, one support shaft 12a
A prismatic portion 13 having a square cross section is formed in the. An Oldham ring 15 having a rectangular long hole 14 is attached to this prismatic portion 13 . That is, the prismatic portion 13 is inserted into the elongated hole 14 of the ring 15, and the ring is fitted to be slidable along the elongated hole 14. A pair of through holes are formed in the ring 15 and extend in the radial direction perpendicular to the longitudinal direction of the elongated hole 14, and one end of the bottle 16 is slidably inserted into these through holes. The other end of each pin 16 is fixed within a through hole 17 formed in the cylinder 7. Note that the outer end of each through hole 17 is hermetically closed with a cap 18.

The rod 11 is supported with respect to the cylinder 7 by the Oldham ring 15 configured as described above so as to be eccentric in the radial direction of the cylinder. Therefore, when the electric motor section 3 is energized and the cylinder 7 is rotated integrally with the rotor 6, the rotational force of the cylinder 7 is transmitted to the rotating rod 11 via the Oldham ring 15. As a result, the rod 11 is internally rotated within the cylinder 7 with a portion of the rod 11 in contact with the inner circumferential surface of the cylinder 7, and rotates relative to the cylinder 7.

As shown in FIGS. 2 to 4, a spiral groove 19 is formed on the outer peripheral surface of the rotating rod 11 and extends between both ends of the rod 11.
is formed. The grooves 19 are formed such that the pitch thereof gradually decreases from the right end to the left end of the cylinder 7 in the figure, that is, from the suction side to the discharge side of the cylinder. Further, the total length of the groove 19 is larger than the total length of the blade 21, which will be described later, and when the rod 11 is assembled into the cylinder 7, the end of the groove 19
As shown in FIGS. 4 and 6, a gap G is provided between the ends of the .

Gap G is provided to allow relative movement, in particular pivoting movement, of blade 21 with respect to rod 11.

The total length of both gaps G is set to be approximately twice or more the eccentricity e of the rod 1 with respect to the cylinder 7. Note that, for example, due to thermal expansion of the blade 21 or the like, the total dimension of the gap may not be exactly twice the eccentricity e, but may be less than twice the eccentricity e. Considering this point,
The above-mentioned total dimension is set to be approximately twice or more the eccentricity e.

A spiral blade 21 shown in FIGS. 3 and 4 is fitted into the groove 19 of the rod 11. As shown in FIGS.

This blade 21 is made of an elastic material such as synthetic resin, and is installed in the groove 19 by screwing it into the groove 19 by utilizing its elasticity. The thickness of the blade 21 is the groove 19
It almost matches the width of . Both ends of the blade 21 are located within a plane perpendicular to the axis of the rod 11, and face the end of the blade 19 with a gap G therebetween. Note that when the blade 21 is installed in the groove 19, the blade may be provided biased toward one end of the groove, that is, so that a gap 2G is created at one end of the blade. Each part of the blade 21 is connected to the rotating rod 1 with respect to the groove 19.
It can freely move forward and backward along the radial direction of 1. Further, the outer peripheral surface of the blade 21 is in close contact with the inner peripheral surface of the cylinder 7.

As shown in FIG. 2, the space between the inner circumferential surface of the cylinder 7 and the outer circumferential surface of the rod 11 is partitioned into a plurality of working chambers 22 by blades 21. As shown in FIG. Each working chamber 22 is
It is defined between two adjacent windings of the blade 21,
As shown in FIG.
It has a substantially crescent shape extending from the contact point between the inner peripheral surface of the cylinder 7 and the inner peripheral surface of the cylinder 7 to the next contact point. The volume of the working chamber 22 gradually decreases from the suction side to the discharge side of the cylinder 7.

As shown in FIG. 2, a suction hole 23 extending in the axial direction of the cylinder 7 is formed through the bearing 8 that supports the suction side end of the cylinder 7 . One end of this suction hole 23 opens into the suction side end of the cylinder 7, and the other end is connected to the suction tube 24 of the refrigeration cycle. Also,
The bearing 9 that supported the discharge side end of the cylinder 7 has a discharge hole 2.
5 is formed. One end of the discharge hole 25 opens into the discharge side end of the cylinder 7, and the other end opens into the inside of the case 2. Note that the discharge hole 25 may be formed in the cylinder 7.

Further, an oil introduction passage 26 is formed inside the rod 11 and extends from the right end of the rod to approximately the middle thereof. The right end of the passage 26 is connected to a passage 27 formed in the bearing 8 and the introduction pipe 2.
8, it communicates with the inside of the case 2, particularly the bottom of the case. The left end of the passage 26 is connected to the groove 1 formed in the rod 11.
It opens at the bottom of 9. Lubricating oil 29 is stored at the bottom of the case 1o. Therefore, when the pressure inside the case 2 increases, the oil 29 flows through the inlet pipe 28 and the passage 27°26.
is introduced into the space between the bottom of the groove 19 and the blade 21 through it.

As shown in FIGS. 2 and 3, a suction groove 31 is formed on the outer peripheral surface of the suction side end of the rotating rod 11. As shown in FIGS. The groove 31 extends in the axial direction of the rod 11 and is formed deeper than the spiral groove 19. One end of the groove 31 is connected to the large diameter portion 11 of the rod 11. It opens at the end surface of H, and the other end extends to a position communicating with the first working chamber located at the suction side end of the cylinder 7 among the working chambers 22 . Therefore, the refrigerant gas sucked into the cylinder 7 from the suction tube 24 is reliably introduced into the first working chamber 22 through the suction groove 31 without interruption.

In FIG. 2, reference numeral 32 indicates a discharge tube communicating with the inside of the case 2.

Next, among the working chambers 22 formed between the inner periphery of the cylinder 7 and the outer periphery of the rod 11 and partitioned by the blades 21, the blade 21 and this portion partition the first working chamber 22 closest to the blowing side. The spiral shape of the groove 19 will be explained. Figure 1 shows the characteristics of the spiral shape of this part. In the figure, the horizontal axis indicates the rotation angle during one rotation of the rod 11, and the axis indicates the axial distance from the suction end side of the blade 21 at each blade position angle. That is, blade 2
The curve on the suction end side of the blade 1 is concave, and therefore the shape of the blade 21 is convex toward the discharge side. On the other hand, the curve M on the discharge side of the blade 21 is convex, and therefore the shape of the blade 21 is convex toward the suction side. The intermediate portion between the curve and M is a straight line, so that the slope of the blade 21 does not change sharply and the twist is gentle.

Next, the operation of the compressor configured as above will be explained.

First, when the electric motor section 3 is energized, the rotor 6 rotates.
The cylinder 7 also rotates together with this. At the same time, the rotating rod 11 is driven to rotate with a portion of its outer circumferential surface in contact with the inner circumferential surface of the cylinder 7 .

Such relative eccentric rotational movement between the rod 11 and the cylinder 7 is ensured by a transmission means, that is, an Oldham ring 15 provided on the prismatic portion 13 of the support shaft 12a.

The blade 21 is pressed toward the outer peripheral surface of the cylinder 7 by the pressure of the lubricating oil introduced into the bottom of the spiral groove 19 through the oil introduction path 26, and the outer peripheral surface of the blade is in close contact with the inner peripheral surface of the cylinder 7. There is.

Therefore, the frictional force between the blade 21 and the cylinder 7 is greater than the frictional force between the blade 21 and the rod 11, and the blade 21 rotates with its outer peripheral surface in contact with the inner peripheral surface of the cylinder 7. Each part of the blade 21 performs a turning motion with respect to the rod 11.

That is, each part of the blade 21 has grooves 1 as it approaches the contact area between the outer circumferential surface of the rod 11 and the inner circumferential surface of the cylinder 7.
9, and as it moves away from the contact portion, it moves in the direction of popping out from the groove. In other words, each part of the blade 21 is
The cylinder 7 moves relative to the rod 11 in the radial direction. Further, a spiral groove 1 in which a blade 21 is inserted is formed.
9 is formed longer than the end of the blade 21 and has a play G portion, which is longer than the length that allows the blade 21 to pivot relative to the piston 11 when the compressor is assembled.

Therefore, the blade 21 does not pivot relative to the piston 11, and the arrow X in FIG. 6 indicates the axis of the pivoting motion of the end of the blade 21. ), it rotates integrally with the cylinder 7 without almost sliding. For this reason,
The sliding loss between the blade 21 and the cylinder 7 can be reduced, and efficiency can be improved.

On the other hand, when the compression section 4 is activated, refrigerant gas is sucked into the cylinder 7 through the suction tube 24 and the suction hole 23 . This gas passes through the introduction groove 31 and is first confined in the first working chamber 22 located on the most suction side of the cylinder 7. As shown in FIGS. 7 to 11, as the rotating rod 11 rotates, the gas is trapped between two adjacent windings of the blade 21.
It is sequentially transferred to the working chamber on the discharge side. And the working chamber 22
Since the volume of the refrigerant gas gradually decreases from the suction side to the discharge side of the cylinder 7, the refrigerant gas is compressed just as it is transferred to the discharge side. The compressed refrigerant gas is then discharged into the case 2 through the discharge hole 25 formed in the bearing 9, and further returned into the refrigeration cycle through the discharge tube 32.

When the pressure inside the case 2 increases due to the discharged refrigerant gas, the lubricating oil 29 stored inside the case is pressurized and passes through the oil introduction path 26 into the space between the bottom of the spiral groove 19 and the blade 21. will be introduced in Therefore, blade 2
1 is pressed by hydraulic pressure in the direction in which it pops out from the cylinder 7, that is, toward the inner circumferential surface of the cylinder 7. Therefore, the outer circumferential surface of the blade 2 is always kept in close contact with the inner circumferential surface of the cylinder 7. As a result, gas leakage between the working chambers 22 can be reliably prevented.

In addition, the blade 21 that partitions the working chamber 22 closest to the suction side and the groove 19 in which this blade 21 is fitted,
By making the suction side convex toward the discharge side,
The volume of the working chamber 22 in that portion can be increased. In addition, by making the connecting portion between the blade 21 and the discharge side portion convex in the opposite direction of the groove 19 into a straight line, the twisting of the blade 21 becomes gentle, and the blade 21
damage can be prevented.

Note that this invention is not limited to the embodiments described above, and can be modified in various ways within the scope of this invention. For example, the present invention is not limited to compressors combined with refrigeration cycles;
It can also be adapted to other compressors.

〔Effect of the invention〕

As explained above, according to the fluid compressor of the present invention,
The helical shape of the blade and groove closest to the suction side is connected by a straight part in the middle of the curved part, so the twisting of the blade is gentle, preventing damage and increasing the discharge capacity. can.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between blade rotation angle and axial distance in an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing the overall configuration of a fluid compressor to which this embodiment is applied, and FIG. 3
The figure is an exploded side view showing the configuration of the compression section, FIG. 4 is an external perspective view, FIG. 5 is a cross-sectional view showing the Oldham ring section in FIG. 2, and FIG. 6 is the compression section in FIG. 2. A partially sectional side view, FIGS. 7 to 11 are sequential illustrations of the compression process of refrigerant gas, FIG. 12 is a sectional view showing the configuration of an example of a compression section in a conventional compressor, and FIG. 13 is a FIG. 4 is a diagram similarly showing the relationship between the rotation angle and the axial distance of the blade. 1...Fluid compressor 3...Driving means (electric motor part) 7...Cylinder 11...Rotating body (rod) 19...Groove 21...Blade 22...Working chamber ring member Patent Attorney Hide Miyoshi Axial direction JL % Son 3t″2′1 % 11

Claims (1)

[Claims] A cylinder that sucks in compressed fluid from one end and discharges it from the other end, and a cylinder that is installed eccentrically along the axial direction of the cylinder, with a part of its outer circumferential surface in contact with the inner circumferential surface of the cylinder. A cylindrical rotating body supported so as to be rotatable relative to the cylinder, and a pitch formed on the outer peripheral surface of the rotating body that gradually becomes smaller from the suction end side to the discharge end side of the cylinder. a spiral groove; and an outer circumferential surface that is slidably fitted into the groove along the radial direction of the rotating body and that is in close contact with the inner circumferential surface of the cylinder; a spiral blade that divides a space between the rotating body and the outer peripheral surface into a plurality of working chambers, and rotating the rotating body in synchronization with the cylinder;
and a drive means for sequentially transferring the fluid to be compressed that has flowed into the working chamber from the suction end side of the cylinder to the working chamber on the discharge side of the cylinder, the fluid compressor comprising: The shapes of the blades and grooves that partition the working chamber near the side are shown with the horizontal axis representing the blade position angle and the vertical axis representing the axial distance from the suction side.
A fluid compressor characterized in that the groove curve is concave on the suction side and convex on the discharge side, and the connecting portion thereof is linear.