JP3064050B2 - Scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a scroll type fluid machine.

[0002]

2. Description of the Related Art An example of a conventional scroll compressor is shown in FIG.
The interior of the sealed housing 8 is partitioned into a high-pressure side 44 and a low-pressure side 45 by the discharge cover 31. Inside the low-pressure side 45, a scroll-type compression mechanism C is disposed at an upper part thereof, and an electric motor M is disposed at a lower part thereof. The electric motor M includes a rotor Ma and a stator Mb.
Is fixed to the rotating shaft 5, and the stator Mb is fixed by press-fitting into the closed housing 8. The scroll type compression mechanism C has a fixed scroll 1 and an orbiting scroll 2. The fixed scroll 1 includes an end plate 11 and a spiral wrap 12 erected on the inner surface thereof. A discharge port 13 is provided.
The orbiting scroll 2 includes an end plate 21 and a spiral wrap 22 erected on the inner surface of the end plate 21. A drive bush 54 rotates via a slewing bearing 73 in a boss 23 erected on the outer surface of the end plate 21. An eccentric pin 53 protruding from the upper end of the rotary shaft 5 is slidably fitted into a slide hole formed in the drive bush 54 so as to be freely inserted. The fixed scroll 1 and the orbiting scroll 2 are eccentric to each other by a predetermined distance, and are engaged with each other at an angle of 180 degrees to form a plurality of closed spaces 24. The orbiting scroll 2 is slidably supported on a casing 6 fixed in a sealed housing 8, and allows the orbiting scroll 2 to revolve orbit between the orbiting scroll 2 and the casing 6, but prevents the orbiting scroll from rotating. A rotation prevention mechanism 3 including an Oldham link is provided. Fixed scroll 1, the end plate 11 periphery is supported freely on the casing 6 flying through the disposed a support spring 32, and the back of the end plate 11 of the fixed scroll 1 is centered at the center Concentric cylindrical flanges 15, 16
Are formed to project upward, and between them, cylindrical flanges 38 and 39 projecting downward from the lower surface of the discharge cover 31 are hermetically slidable via a pair of inner and outer seal members 37. back pressure chamber 40 surrounded by these by fitting is formed, the back pressure chamber 40,
It communicates with the sealed space 24 in the middle of gas compression through a pressure guiding hole 41 formed in the end plate 11. Here the pressure guide hole 4
1 is located at a point in contact with the inner diameter side of the wrap 12.
A high pressure chamber 42 is formed on the inner peripheral side of the back pressure chamber (also called an intermediate pressure chamber) 40, and a low pressure chamber 43 is formed on the outer peripheral side. The upper end of the rotary shaft 5 is more journalled to the upper bearing 71 provided in the casing 6, the lower end is lower bearing 72
It is more journaled in. In such a structure, by driving the electric motor M, the orbiting scroll 2 is driven by the orbiting drive mechanism including the rotary shaft 5, the eccentric pin 53, the drive bush 54, the boss 23, and the like.
The orbiting scroll 2 makes a revolving orbiting motion on a circular orbit having a revolving orbital radius while being prevented from rotating by the rotation preventing mechanism 3. Then, the gas enters the low-pressure chamber 45 via the suction pipe 82, and passes through the closed space 24 via a path (not shown).
Inhaled into. As the volume of the closed space 24 decreases due to the orbital motion of the orbiting scroll 2,
The gas reaches the central portion while being compressed, enters the high-pressure side 44 from the discharge port 13 through the high-pressure chamber 42, and is discharged to the outside by pushing and opening the discharge pipe 83 and the check valve incorporated therein. At this time, the fixed scroll 1 is pressed against the orbiting scroll 2 by the gas pressure in the high-pressure chamber 42 and the back-pressure chamber 40, thereby suppressing gas leakage from the closed space 24. When the liquid is sucked into the closed space 24, the fixed scroll 1 floats and escapes the liquid, thereby preventing the scroll-type compression mechanism from being damaged .

[0003]

In this type of scroll type compressor, the fixed scroll 1 is turned by the back pressure load based on the areas of the high pressure chamber 42, the intermediate pressure chamber 40 and the low pressure chamber 43 and the gas pressure. 2 to prevent gas from leaking from inside the sealed space 24. Here, the back pressure load is desirably substantially equal to the in-cylinder load that pushes up the fixed scroll 1 upward based on each area of the closed space 24 and its gas pressure. By the way, the pressure on the suction side (the pressure in the low pressure chamber 43) and the pressure on the discharge side (the pressure in the high pressure chamber 42) of the compressor are variously changed depending on the operating conditions of the refrigeration system in which this kind of compressor is incorporated. It is important to apply an appropriate back pressure load to the fixed scroll 1 for all operating conditions. On the other hand, the relationship between the pressure in the intermediate pressure chamber 40 and the pressure in the low pressure chamber 43 has been elucidated, and the areas of the intermediate pressure chamber 40 and the low pressure chamber 43 are set based on this relationship. However, how to set the area of the high-pressure chamber 42 has not been clarified yet. For this reason, in particular, the back pressure load applied to the fixed scroll 1 becomes excessively large, which may damage the fixed scroll and the orbiting scroll and increase the required power of the compressor.

The present invention has been proposed in view of such circumstances, and by appropriately setting the area of a high pressure chamber,
An object of the present invention is to provide a long-life scroll type fluid machine that prevents damage to a compression mechanism.

[0005]

For that purpose, the screen of the present invention is used.
Roll type fluid machines are swirled on the inner surface side of each end plate.
Fixed scroll and orbiting scroll with vertical wrap
Fixed scroll and orbit
Multiple closed spaces are formed between the scrolls and fixed
The center part on the back side of the scroll communicates with the above enclosed space
Pressure of the discharge fluid discharged from the enclosed space
A scroll-type fluid machine having a high-pressure chamber formed therein,
Fluid pressure of the discharge fluid discharged into the high-pressure chamber acts.
Of the fluid pressure acting surface on the back surface of the fixed scroll
The area is the innermost two enclosed spaces among the above enclosed spaces.
Immediately after communication with each other, the fixed scroll and
Multiple contacts where the orbiting scroll wraps abut each other
Of the circle whose diameter is the distance between the two innermost contacts
It is characterized by being set to be equal to or less than the product.

[0006]

According to such a configuration, the area of the high-pressure chamber is equal to or larger than the average value of the area of the closed space in the discharge pressure state when the orbiting scroll makes one revolution by the revolving orbiting operation. Is also set small. Accordingly, the load applied from the back of the fixed scroll or the orbiting scroll by the high-pressure chamber is equal to or smaller than the load applied from the inner surface of the fixed scroll or the orbiting scroll by the closed space in the discharge pressure state. the operating conditions of the refrigeration system is not an excessive back pressure load is the load also <br/> fixed scroll or the orbiting scroll and various variations are incorporated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a horizontal sectional view showing a scroll portion thereof.
Its longitudinal sectional view is substantially the same as FIG. The area of the high-pressure chamber 42 in the present invention is set as follows. That is, meshes wrapped 12 and the orbiting scroll 2 in the lap 22 of the fixed scroll 1, to form a multilayer of several closed space 24 in point symmetry, the volume of the closed space 24, the wrap 22 is fixed orbiting scroll 2 It changes with the movement of the position where the scroll 1 comes into contact with the wrap 12. The innermost two closed spaces 24A, 24B formed on the most central sides of the fixed scroll 1 and the orbiting scroll 2.
Immediately after passing through each other (that is, the base ends of the wraps 12, 22).
When wrap 12 and 22 to each other at the point of contact P immediately after each other is separated from the state of being in contact) is two points of abutting at its innermost A, and B of the area of the high pressure chamber, the point A, B
The opening area of the discharge port 13 is set as the lower limit, which is the same as or smaller than the area of a circle whose diameter is the distance between them. Here, the area of a circle whose diameter is the distance between the points A and B corresponds to the closed space 24 in the discharge pressure state when the orbiting scroll 2 makes one revolution due to the revolving orbiting motion (the closed space 24 in the closed space 24). The pressure is sufficient for the compressed gas to be discharged through the discharge port 13). Accordingly, the load for pushing the fixed scroll 1 downward by the high-pressure chamber 42 is equal to or smaller than the load for pushing the fixed scroll 1 upward by the sealed space 24 in the discharge pressure state. Even if the operating conditions of the refrigeration system vary, the fixed scroll 1 is not subjected to an excessive back pressure load.

[0008]

Effects of the Invention] According to this structure, load applied from the back of the fixed scroll by the high pressure chamber is the same or than, the load applied from the inner surface of the fixed scroll by the enclosed space in the discharge pressure state becomes small, even if the operating conditions of the refrigeration apparatus to which the compressor is incorporated is variously changed, not that excessive back pressure load is loaded on the fixed scroll, the damage results fixed scroll and the orbiting scroll Thus, an increase in required power of the compressor can be suppressed.

In short, the scroll type fluid machine of the present invention
According to the spiral wrap on the inner surface of each end plate
The fixed scroll and the orbiting scroll that are erected
Meshed between the fixed scroll and the orbiting scroll
A plurality of closed spaces are formed in the fixed scroll.
The central part on the back side communicates with the above enclosed space
The high pressure chamber in which the fluid pressure of the discharge fluid discharged from
The scroll-type fluid machine formed, wherein the high-pressure chamber
Fixed by the fluid pressure of the discharge fluid discharged to
The area of the fluid pressure acting surface on the back of the scroll is
Two innermost enclosed spaces communicate with each other
Immediately after the fixed scroll and orbiting scroll
Innermost circumference of the multiple contacts where each wrap of the
Set to be less than the area of the circle whose diameter is the distance between the two contacts
Therefore, the present invention is extremely useful in industry, since a scroll-type fluid machine having a long life and preventing damage to the compression mechanism is obtained.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view showing a scroll unit according to one embodiment of the present invention.

FIG. 2 is an overall vertical sectional view showing a conventional scroll compressor.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 fixed scroll 2 orbiting scroll 11 end plate 12 lap 21 end plate 22 lap 24 closed space 24A closed space 24B closed space 40 intermediate pressure chamber 42 high pressure chamber 43 low pressure chamber

Claims (1)

(57) [Claims] 1. A spiral roller is provided on the inner surface of each end plate.
Fixed scroll and orbiting scroll
The fixed scroll and the orbiting scroll are meshed with each other.
Multiple closed spaces are formed between the
The center of the rear side of the
High pressure at which the fluid pressure of the discharge fluid discharged from the closed space acts
A scroll-type fluid machine in which a chamber is formed,
The fluid pressure of the discharge fluid discharged into the pressure chamber acts.
Area of the fluid pressure acting surface on the back of the fixed scroll
However, the innermost two enclosed spaces of the above enclosed spaces are mutually
Immediately after communication with the
Multiple contact points where each wrap of the scroll abuts each other
The area of a circle whose diameter is the distance between the two innermost contacts
Scroll type flow characterized by being set below
Body machine.