JPH09170572A - Scroll type fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain noise caused by increase of pressing force by inertial force. SOLUTION: This fluid machine is constituted to change a rotational and revolutional radius of a revolving scroll. Increase of pressing force at the time of high speed rotation is set off by providing a slide member 20 to vary a slide angle θ in accordance with the number of rotation between a slide hole 7 of a drive bush 5 and a slide surface of an eccentric pin 9 and reducing the slide angle θ of the eccentric pin 9 by inertial force of the slide member 20 at the time when the inertial force becomes proportional to a square of the number of rotation and the pressing force increases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine which is constituted by combining a fixed scroll and an orbiting scroll and is used as a compressor and an expander.

[0002]

2. Description of the Related Art In an air conditioner, a scroll type compressor (scroll type fluid machine) has recently been adopted because of the advantage that it can perform efficient compression. As shown in FIG. 9, the scroll type compressor includes a fixed scroll 1 in which a spiral wrap 1b is erected on an inner surface of an end plate 1a,
An orbiting scroll 2 in which a spiral wrap 2b having substantially the same shape as the wrap 1b is erected on the inner surface of the end plate 2a.
And

The fixed scroll 1 and the orbiting scroll 2 have their centers O ₁ and O 2 eccentric by a predetermined distance r, and their phases are shifted by 180 °, and the wrap 1 is formed.
b and 2b are intermeshed with each other to form a plurality of compression chambers 3 which are point-symmetric with respect to the center of the spiral between the wraps.

The drive structure for the orbiting scroll 2 is such that a cylindrical boss 4 projecting from the center of the outer surface of the end plate 2a of the orbiting scroll 2 is offset from the end face of the rotary shaft 8 by a predetermined distance r from its axis 0 _1. An eccentric rotation structure in which an eccentric pin 9 that projects in a centered manner is fitted is employed, and by rotating a rotating shaft 8 by a motor (not shown), the orbiting scroll 2 is rotated around the axis of the fixed scroll 1, that is, the rotating shaft 8 and the circular orbit of a predetermined distance r between the radius around the center O ₁ of the fixed scroll 1 are so as to orbital exercise.
The rotation of the orbiting scroll 2 is restricted by a rotation prevention mechanism such as an Oldham ring (not shown).

By driving the orbiting scroll 2, the compression chamber 3 moves toward the center of the spiral while reducing its volume. Due to this behavior, the compression chamber 3
The compressed gas sucked inside is gradually compressed, and the compressed gas is discharged from the discharge port 12 to the outside through the central chamber 11.

By the way, in the scroll type compressor, when the eccentricity r of the orbiting scroll 2 is set so that the radial gap between the wraps becomes 0, depending on the shape accuracy of the fixed scroll 1 and the orbiting scroll 2, during operation, Unreasonable force may be applied to the bearing.

Therefore, in the scroll compressor, the radial gap between the wraps is made zero by utilizing the force generated during operation. As shown in FIG. 10, a cylindrical drive bush 5 having a slide hole 7 formed therein is rotatably fitted in a cylindrical boss 4 via a bearing 6, and this drive is driven. An eccentric pin 9 protruding from the end surface of the rotary shaft 8 is slidably fitted into the slide hole 7 of the bush 6 to use a mechanism capable of changing the revolution radius of the orbiting scroll 2.

Specifically, the slide hole 7 has an eccentric pin 9
The eccentric pin 9 is formed in an oval shape having a linear slide surface 7a extending in the radial direction that is inclined at an angle θ with respect to the eccentric direction of the eccentric direction. The slide surface 9a of the eccentric pin 9 is slidably contacted with the slide surface 7a of the slide hole 7 so that the slide surface 9a can slide along the slide surface 7a.

That is, the eccentric pin 9 is inserted into the slide hole 7 of the drive bush 6 so that the planes of the eccentric pin 9 and the slide hole 7 are combined, and the eccentric pin 9 is bossed. 4 is connected so that it can slide in the radial direction and does not rotate.

As a result, the rotational force from the rotary shaft 8 is transmitted from the slide surface 9a of the eccentric pin 9 to the drive bush 5 via the slide surface 7a of the slide hole 7, and further through the bearing 6 and the boss 4 to the orbiting scroll. 2 is transmitted.

At the same time, the drive bush 7 is centrifugally moved toward the eccentric direction of the eccentric pin 9 due to the unbalanced weight composed of the orbiting scroll 2, the boss 4, the bearing 6, the drive bush 5 and the like, which is generated by the orbiting motion of the scroll 2. In the direction of the slide angle θ formed by the radial direction and the slide surface 7 a of the drive bush 7, the component force of the force F _S and the gas pressure F _P in the compression chamber 3 acting on the orbiting scroll 2 is received. By sliding (the orbiting radius of the orbiting scroll 2 increases), the side surface of the wrap 2b of the orbiting scroll 2 is pressed against the side surface of the wrap 1b of the fixed scroll 1, and during operation,
The radial gap between the laps is always zero.

At this time, the force F by which the side surface of the wrap 2b presses the side surface of the wrap 1b is F = F _S + F _P cos θ _p + F _d sin θ (1) where F _d is the drive bush driving force, which is shown in FIG. From the vertical balance F _d = F _P sin θ _p / cos θ (2)
It is expressed as However, in equations (1) and (2), the frictional force of the slide surface 7a of the drive bush 5 when the turning radius changes is omitted.

[0013]

By the way, the fixed scroll 1 and the orbiting scroll 2 come into contact with each other by the pressing force F, but if the pressing force F can be positively secured at this time, the sealing property of the compressed gas is secured, which is good. Efficiency can be maintained.

However, if the pressing force F is further increased, the contact between the scrolls 1 and 2 becomes stronger, but the improvement in the sealing property of the compressed gas becomes slower, and the expected improvement in efficiency cannot be obtained.

On the contrary, the pressing force F is the orbiting scroll 2
Is a vibration source that excites, propagates vibration, and radiates noise. Therefore, an increase in the pressing force F has a harmful effect of significantly increasing noise.

Here, as shown in FIGS. 11 (a) and 11 (b), the larger the slide angle θ is set, the larger the value of F _d sin θ in the equation (1) becomes, and the pressing force F is accordingly increased. Shows a behavior of increasing.

Therefore, in the scroll type compressor, in order to achieve both high efficiency and low noise, the slide angle θ is set so that the pressing force F is positive and the one is as low as possible under various operating conditions. ing.

However, the scroll type compressor is operated at a high speed by adopting a variable speed, or is operated at a high speed such as 60 HZ when the power frequency is 50 HZ.

Therefore, when θ is set as described above at a low rotational speed in order to ensure a good sealing property, low noise is ensured in a low rotational speed range, but at the time of high speed rotation (variable speed compression). In the case of high-speed rotation of the machine or in the case of 60 HZ rotation with respect to 50 HZ), the inertial force increases in proportion to the rotation speed ω ² , so that the pressing force F increases remarkably and the noise increases. is there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a scroll type fluid machine capable of suppressing noise caused by an increase in pressing force due to inertial force.

[0021]

In order to achieve the above object, the invention set forth in claim 1 is a scroll type fluid machine in which the revolution revolution radius of an orbiting scroll is variable, and a slide hole of a drive bush and a slide of an eccentric pin. This is because a slide member that changes the slide angle according to the rotation speed is provided between the surfaces.

According to the invention described in claim 1, when the pressing force F increases in proportion to the square of the rotation speed due to the inertial force of the slide member, the sliding angle of the eccentric pin becomes small, and the high-speed rotation occurs. This offsets the increase in the pressing force of time.

Then, at the time of high speed rotation, the pressing force is reduced to the same level as at the time of low speed rotation. This reduces vibration propagation and suppresses an increase in noise due to an increase in pressing force due to inertial force.

As a result, noise reduction is realized in a wide range from low rotation speed to high rotation speed. In addition to the above object, the invention described in claim 2 has a structure in which the slide member of claim 1 is supported by a spring in order to support the slide member so as to be capable of returning with a simple structure.

According to the invention described in claim 3, in addition to the above object, a stepped groove is provided on the slide surface of the slide hole according to claim 2 in order to stabilize the position of the spring, and the stepped groove is provided in this stepped groove. There is a spring installed.

According to the invention described in claim 4, in addition to the above object, the slide member of claim 1 is elastically deformed with a spring property in order to displace the slide angle according to the change of the inertia force with the simplest structure. It consists of wood.

According to the invention described in claim 5, in order to displace the slide angle according to the change of the inertia force with the same simple structure, the slide hole of the drive bush and the slide surface of the eccentric pin are curved surfaces. This is because the contact point is changed according to the number of rotations to change the slide angle.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on the first embodiment shown in FIG. The present embodiment is characterized by the structure around the drive bush 5, and other scroll structures and scroll power transmission structures are the same as those of the "conventional technique" described above.
Since it is the same as the structure described in the section (1), the description of the structure of the same part is omitted, and the characteristic part (the essential part of the invention) will be described here.

That is, in this embodiment, the slide member 20 for varying the slide angle θ according to the rotation speed of the rotating shaft 8 is interposed between the slide surface 7a of the drive bush 5 and the slide surface 9a of the eccentric pin 9. I was wearing it.

More specifically, the slide member 20 is composed of a plate member whose thickness dimension decreases toward the axial center of the rotary shaft 8, for example. Further, a portion of the drive bush 5 facing the slide surface 7a is notched in a slide surface 9a which is inclined so as to be lowered as it moves away from the axis of the rotary shaft 8, and the slide member 20 is accommodated in the notch portion 21. ing.

An elastic member, for example, a spring, more specifically, a coil spring 22, is interposed between the lower surface of the slide member 20 and the inner surface of the notch 21 facing the slide member 20, and the slide member 20 swings with one side as a fulcrum. It is elastically supported as much as possible.

As a result, the slide member 20 is slidably supported at the set position of the eccentric pin 9. The slide member 20 rotates at a high speed and has an inertia force of a coil spring 22.
When it is increased to exceed the pressing force of, due to the inertial force of the slide member itself (proportional to the square with respect to the rotation speed ω),
The entire slide member moves radially outward to reduce the angle γ between the drive bush 5 and the slide surface of the eccentric pin 9.

The displacement of the slide member 20 causes the eccentric pin 9 to move outward in the radial direction to reduce the slide angle θ. Of course, if the inertial force becomes small, the elastic force of the coil spring 22 causes the sliding member 20 to move.
Returns and the slide angle θ returns.

Next, the operation will be described. When the rotational force from the rotating shaft 8 is transmitted to the slide surface 9a of the eccentric pin 9, the slide surface 7a of the slide hole 7, the drive bush 5, the bearing 6, and the boss 4, the scroll compressor rotates the orbiting scroll 2. Revolving movement is performed around the axis of the fixed scroll 1, that is, on a circular orbit having a radius of a predetermined distance r around the rotation shaft 8 and the center O ₁ of the fixed scroll 1. The orbiting scroll 2 does not rotate due to the rotation preventing mechanism.

By driving the orbiting scroll 2, the compression chamber 3 moves toward the center of the spiral while reducing its volume, and the compressed gas sucked into the compression chamber 3 is gradually compressed.

Here, it is assumed that the slide angle θ is set under the operating condition at a low rotation speed. At this time, if the compressor is operated at a low rotation speed, the slide member 20 is
Since the inertial force that moves outward in the radial direction is not generated, the slide angle θ is maintained as it is.

As a result, the drive bush 7 moves toward the eccentric direction of the eccentric pin 9 due to the unbalanced weight of the orbiting scroll 2, the boss 4, the bearing 6, the drive bush 5 and the like, which is generated along with the orbiting motion of the scroll 2. The centrifugal force F _S and the gas pressure F _P in the compression chamber 3 that acts on the orbiting scroll 2 cause a component force to slide in the direction of the slide angle θ (the orbiting radius of the orbiting scroll 2 increases). Then, the side surface of the wrap 2b of the orbiting scroll 2 is pressed against the side surface of the wrap 1b of the fixed scroll 1 to make the radial gap between the wraps zero.

Next, when the motor is operated at a high speed, the inertial force increases in proportion to the rotation speed ω ² , and the pressing force F tends to increase. At this time, if the inertial force of the slide member 20 increases until it exceeds the pressing force of the coil spring 22,
The inertial force of the slide member itself (proportional to the square with respect to the rotation speed ω) causes the entire slide member to move outward in the radial direction.

As a result, the angle γ between the drive bush 5 and the sliding surface of the eccentric pin 9 becomes small. Then, the eccentric pin 9 also moves.

As a result, the slide angle θ becomes smaller.
Here, the force F by which the side surface of the wrap 2b presses the side surface of the wrap 1b, which is obtained by the above-described formula (1), includes a component (F _d sin θ) that increases as the slide angle θ increases.

In other words, as the slide angle θ becomes smaller, the pressing force F, which is the exciting force of noise, acts in a decreasing direction. This means that the pressing force F, which tends to increase, is offset by the behavior that the slide angle θ decreases at the time of high speed rotation.

As a result, the pressing force F that is positive and is as low as possible is maintained even during high speed rotation. Therefore, vibration propagation is reduced, and it is possible to suppress an increase in noise due to an increase in the pressing force F due to the inertial force.

Therefore, noise reduction in a wide range from low rotation speed to high rotation speed can be realized. In particular, when the slide member 20 is supported by the spring 22, the slide member 20 can be supported by the simple structure so as to be able to return.

FIG. 2 shows a second embodiment of the present invention.
In this embodiment, the installation direction of the slide member 20 is reversed. Even in this case, the same effect as that of the first embodiment is obtained.

FIG. 3 shows a third embodiment of the present invention.
The present embodiment is a modification of the first embodiment, and a stepped groove 25 is provided on the inner surface of the slide hole 7, and a spring for supporting the slide member 20, for example, a coil spring 22 is installed in the stepped groove 25. It is a thing.

When the coil spring 22 is thus installed in the stepped groove 25, the spring 22 is restricted by the inner surface of the stepped groove 25, so that the spring position is stabilized.
Of course, even with such a structure, the same effect as that of the first embodiment can be obtained.

FIG. 4 shows a fourth embodiment of the present invention.
The present embodiment is a modification of the first embodiment, in which a balance weight 30 is added to the slide member 20.

In such a structure to which the balance weight 30 is added, the range in which the inertial force can be controlled is widened by the weight of the balance weight 30, so that the change amount of the slide angle θ can be made larger and can be set more freely.

As a result, the amount of offset of the increase in the pressing force F at the time of high speed rotation can be set large, and the effect of suppressing noise can be increased accordingly. 5 and 6 show a fifth embodiment of the present invention.

In this embodiment, the slide hole 7 and the eccentric pin 9 are used.
The respective slide surfaces 7a and 9a are curved surfaces, and the slide point θ is made variable by changing the contact point position according to the number of rotations.

Specifically, for example, the slide surface 9a of the eccentric pin 9 is formed into a curved surface having a small curvature, and the slide surface 7a of the slide hole 7 is formed into a curved surface having a smaller curvature than that, and the contact between them is made. The function of changing the slide angle θ is generated by the point.

To explain this point, during high-speed rotation, the orbiting radius increases due to centrifugal force, so that the boss 4 of the orbiting scroll 2 together with the drive bush 5 becomes
It is pressed to the outside of the radius.

Then, as shown in FIG. 6A, the contact point between the eccentric pin 9 and the drive bush 5 relatively moves inward in the radial direction of the slide surface 9a of the eccentric pin 9. Then, the slide angle θ becomes smaller.

Since the change of the slide angle θ acts in the direction in which the pressing force F decreases as described in the first embodiment, it acts in the direction of canceling the increase in the pressing force F at the time of high speed rotation. The increase in noise due to the increase in the pressing force F can be suppressed.

On the other hand, during low speed rotation, on the contrary, the centrifugal force is small, so that the contact point between the slide surface 9a of the eccentric pin 9 and the slide surface 7a of the drive bush 5 is relative as shown in FIG. 6 (b). To the outer side of the eccentric pin 9 in the radial direction.

Then, the slide angle θ becomes large. As a result, the pressing force F increases. Here, since the pressing force itself is small at low speed rotation, even if the slide angle θ is slightly increased, there is no adverse effect on noise as at high speed rotation. Rather, since the pressing force F is small, there is a large amount of leakage between the laps, and the performance tends to deteriorate as compared with high-speed rotation. However, the action of increasing the pressing force F brings about an improvement in performance.

Moreover, the drive bush 5 and the eccentric pin 9
Since the sliding surfaces 7a and 9a of 4 are only formed into curved surfaces, they are structurally simple. 7 and 8 show a sixth embodiment of the present invention.

This embodiment is a modification of the first embodiment, in which the slide member 20 is made of an elastically deformable material having a spring property so that the pressing force F at the time of high speed rotation can be increased without using a spring. This is the performance that is offset.

Specifically, the slide member 20 is made of, for example, a substantially V-shaped strip-shaped elastically deformable member, and one side thereof is formed on the inner surface of the drive bush 5, for example. It is embedded and fixed in the stepped groove 34. The sliding surface 35 is provided on the other side surface.
Is formed, and the sliding surface 35 supports the sliding surface 9a of the eccentric pin 9.

Even in this case, at the time of high-speed rotation, the sliding angle θ becomes smaller due to the deformation of the elastically deformable material as shown by the chain double-dashed line in FIG. 8, and the pressing force F that tends to increase is increased. Can be offset.

As a result, the same effect as that of the first embodiment is obtained. Moreover, since only the slide member 20 is required,
It is structurally simple. In addition, in 2nd-6th embodiment, the same code | symbol is attached | subjected to the same part as 1st Embodiment, and the description was abbreviate | omitted.

However, in the first to sixth embodiments, the elastic modulus, position, initial deflection, and slide member 20 of the spring 22 are used.
, The weight of the balance weight 30 (fourth embodiment), the curved surfaces of the eccentric pin 9 and the slide surfaces 7a, 9a of the drive bush 5 (fifth embodiment), etc. It is properly set according to noise characteristics, operating conditions, etc., and is not limited to the embodiment.

[0063]

As described above, according to the invention described in claim 1, the sliding angle can be made small at the time of high speed rotation,
It is possible to offset the pressing force that is increasing due to the inertial force. Therefore, at the time of high speed rotation, a low pressing force can be maintained, and an increase in noise due to an increase in pressing force due to inertial force can be suppressed.

As a result, noise reduction can be realized in a wide range from low rotation speed to high rotation speed. According to the invention described in claim 2, in addition to the effect of the invention of claim 1, there is an effect that the slide member can be supported so as to be capable of returning with a simple structure.

According to the invention described in claim 3, according to claim 2
In addition to the effect of the invention described above, the position of the spring can be stabilized. According to the inventions of claims 4 and 5, in addition to the effect of the invention of claim 1, there is an effect that the slide angle can be displaced in accordance with a change in inertial force with the simplest structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of a scroll type fluid machine according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a scroll type fluid machine according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a main part of a scroll type fluid machine according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of a scroll type fluid machine according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a main part of a scroll type fluid machine according to a fifth embodiment of the present invention.

FIG. 6 is a diagram for explaining that the mutual contact position between the curved slide surface of the drive bush and the curved slide surface of the eccentric pin changes according to a change in the rotational speed in the same embodiment.

FIG. 7 is a sectional view showing a main part of a scroll type fluid machine according to a sixth embodiment of the present invention.

FIG. 8 is an enlarged view showing a slide member made of an elastically deformable material according to the same embodiment.

FIG. 9 is a cross-sectional view for explaining the configuration of the scroll type fluid machine.

FIG. 10 is a cross-sectional view around a boss drive bush of the fluid machine.

FIG. 11 is a diagram for explaining that the force F for pressing the lap changes in accordance with the change in the slide angle θ formed by the radial direction and the slide surface of the drive bush.

[Explanation of symbols]

 1 ... Fixed scroll 1b ... Wrap 2 ... Orbiting scroll 2b ... Wrap 4 ... Boss 5 ... Drive bush 6 ... Bearing 7 ... Sliding hole 7a ... Sliding surface 8 ... Rotating shaft 9 ... Eccentric pin 9a ... Sliding surface 20 ... Sliding member 22 ... Coil spring (spring) 25 ... Stepped groove 30 ... Balance weight.

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[Procedure amendment]

[Submission date] March 22, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

By the way, in the scroll compressor, if the eccentricity r of the orbiting scroll 2 is set so that the radial gap between the wraps becomes zero, the scroll type compressor is in operation depending on the shape accuracy of the fixed scroll 1 and the orbiting scroll 2. , There is a risk that excessive force will be applied to the bearing.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

On the contrary, the pressing force F is the fixed scroll 1
Also , since it is a vibration source that excites the orbiting scroll 2, propagates vibration, and further radiates noise, an increase in the pressing force F has a harmful effect of significantly increasing noise.

[Procedure 3]

[Document name to be amended] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction contents]

FIG. 10

Claims (5)

[Claims] 1. A fixed scroll, an orbiting scroll that is eccentric to the fixed scroll by a predetermined distance, is meshed at a different angle, and is orbitally driven to rotate with respect to the fixed scroll. A drive bush having a slide hole supported by
A scroll type fluid machine comprising an eccentric pin slidably fitted in a slide hole of the drive bush, and a rotary shaft for driving the orbiting scroll via the drive bush. A scroll type fluid machine characterized in that a slide member for varying a slide angle is provided between slide surfaces of an eccentric pin according to a rotation speed. 2. The scroll type fluid machine according to claim 1, wherein the slide member is supported by a spring. 3. The scroll type fluid machine according to claim 2, wherein a stepped groove is provided on a slide surface of the slide hole of the drive bush, and the spring is installed in the stepped groove. 4. The scroll type fluid machine according to claim 1, wherein the slide member is made of an elastically deformable material having a spring property. 5. A fixed scroll, an orbiting scroll that is eccentric to the fixed scroll by a predetermined distance, is meshed at a different angle, and is revolvingly orbitally driven with respect to the fixed scroll, and is rotatable by the orbiting scroll. A drive bush having a slide hole supported by
A scroll type fluid machine comprising an eccentric pin slidably fitted in a slide hole of the drive bush, and a rotary shaft for driving the orbiting scroll via the drive bush. A scroll type fluid machine characterized in that each slide surface of the eccentric pin is a curved surface, and a contact point is changed according to the number of rotations to make a slide angle variable.