JPH05332264A - Scroll compressor - Google Patents

Abstract

PURPOSE:To correct a pressure unbalance, which occurs during delivery between two closed spaces and by which the generation of noise and vibration is caused, by suppressing a re-expansion loss to a low value. CONSTITUTION:The shape of a helical body is formed such that the volume of an innermost chamber surrounded with a fixed scroll helical body 2 and a revolving scroll helical body 5 is reduced to zero. A circular spot facing 8 forming a fluid passage communicated with a delivery port 7 is formed at a fixed scroll end plate 3 such that the volume ratio of a closed space formed outside the revolving scroll helical body 5 and that of a closed space formed inside the revolving scroll helical body are caused to approximately coincide with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor which is a kind of positive displacement fluid machine.

[0002]

2. Description of the Related Art In a scroll compressor disclosed in Japanese Patent Laid-Open No. 56-20701, a scroll of a fixed scroll has a large wrap angle within a range not exceeding 180 ° from a wrap angle of a scroll of an orbiting scroll. Is characterized by. As a result, there is an effect that a wasted space serving as a gas passage is eliminated in the outer peripheral portion of the fixed scroll, the theoretical suction volume is increased, and the size of the scroll per unit volume is reduced. Further, at the completion of suction, in order to correct the pressure imbalance immediately before the discharge of these two spaces due to the difference in the volume of the closed space formed on the outer side of the orbiting scroll spiral body and the volume of the closed space formed on the inner side, By removing the winding start of the orbiting scroll spiral body, the closed space formed outside the orbiting scroll spiral body is quickly communicated with the discharge port to equalize the pressure in both spaces.

[0003]

An involute curve is generally used for the scroll body shapes of the fixed scroll and the orbiting scroll of the scroll compressor. Therefore, the volume of the innermost chamber surrounded by the fixed scroll spiral body and the orbiting scroll spiral body does not become zero, but becomes a clearance volume, and the residual gas in this space re-expands, resulting in a loss and a reduction in efficiency. In Japanese Patent Laid-Open No. 56-20701, since the winding start of the orbiting scroll spiral body is cut off, the volume of the innermost chamber enclosed by the fixed scroll spiral body and the orbiting scroll spiral body further increases, and the re-expansion loss occurs. There is also a problem of increasing. Further, an extra work for scraping off the scroll spiral body is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide means for suppressing re-expansion loss in a scroll compressor and correcting pressure imbalance during discharge of two enclosed spaces which causes noise and vibration. ..

[0005]

In order to achieve the above-mentioned object, the scroll compressor of the present invention has a shape that the volume of the innermost chamber surrounded by the fixed scroll spiral body and the orbiting scroll spiral body. It shall be zero. Further, in order to correct the pressure imbalance immediately before the discharge of the closed space formed outside the orbiting scroll spiral body and the closed space formed inside,
The fixed scroll or the end plate of the orbiting scroll is provided with a fluid passage such as a counterbore for allowing the closed space formed outside the orbiting scroll spiral body to communicate with the discharge port earlier.

[0006]

The closed space formed on the outer side of the orbiting scroll spiral body is expedited by making the innermost chamber surrounded by the fixed scroll spiral body and the orbiting scroll spiral body have a volume of zero. Even when the discharge port is communicated with the innermost chamber (where the volume of the innermost chamber is not zero), the re-expansion loss can be reduced.

Further, since the means for promptly communicating the closed space formed on the outer side of the orbiting scroll scroll with the discharge port is a fluid passage such as a spot facing provided on the fixed scroll end plate, the processing is easy.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 shows a vertical sectional view of the scroll compressor according to the present invention. The scroll compressor 30 includes a fixed scroll 1, an orbiting scroll 4, a crankshaft 20 that rotates the orbiting scroll 4, a frame 21 that supports the crankshaft 20, and an Oldham ring 22 that allows the orbital motion of the orbiting scroll 4 to prevent rotation. , A motor 23 for driving the crankshaft 20. Here, the scrolls of both scrolls 1 and 4 are the scroll of the fixed scroll 1 and the orbiting scroll 4.
With the shape of the innermost chamber surrounded by the spiral body of
The spiral body of the fixed scroll 1 has a larger winding angle than the spiral body of the orbiting scroll 4 within a range not exceeding 180 °.

FIG. 1 is a plan view of a spiral portion of a scroll compressor according to the present invention. In this embodiment, one of the curves forming the fixed scroll spiral body 2 and the orbiting scroll spiral body 5 is an algebraic spiral, and the difference between the winding angle of the fixed scroll spiral body 2 and that of the orbiting scroll spiral body 5 is It is 180 °. Here, the algebraic spiral is represented by the following mathematical expression 1 in polar coordinates (radial radius r, deviation angle θ) with a and k as parameters.

[0011]

[Equation 1]

An algebraic spiral represented by Formula 1 was selected as the inner curve of the scroll of both scrolls, and the inner curve was rotated 180 ° as the outer curve of the scroll, and this was revolved with a turning radius ε. Of the two envelopes that can be made, the inner one is chosen. At this time, the winding start portion of the spiral body connects the outer curve of the spiral body and the inner curve of the spiral body with a smooth straight line so that the volume of the innermost chamber surrounded by the fixed scroll spiral body and the orbiting scroll spiral body is increased. It can be zero.

A suction port 6 is provided at the outer peripheral portion of the fixed scroll end plate 3, a discharge port 7 and a circular counterbore 8 serving as a fluid passage are provided at the central portion. The discharge port 7 is shown in FIG.
As shown in (b), the fixed scroll spiral body 2 is partially cut away. In addition, a cross section of the circular counterbore 8 serving as a fluid passage is shown in FIG.

The scroll compressor 30 having such a configuration
By energizing the motor 23, the crankshaft 20
Is rotated, the orbiting scroll 4 revolves by the Oldham ring 22 without rotating, and a compression action is performed between the scrolls 1 and 4.

FIG. 2 is a plan view showing the state change of the scroll of the scroll compressor according to the present invention. As the revolution advances, the relationship between the fixed scroll spiral body 2 and the orbiting scroll spiral body 5 changes in the order of (a), (b), (c), (d), (e). (A) shows a state in which the closed space formed outside the orbiting scroll spiral body 5 has completed suction.

9s is a closed space at this time. Also,
When the revolution of 180 ° progresses from the state of (a), as shown in (c), the closed space formed inside the orbiting scroll spiral body 5 is in a state where suction is completed. 10s is a closed space at this time. (d) is an angle α from the state of (c)
In the state where the revolution has advanced, the volume of the closed space formed on the outer side of the orbiting scroll spiral body 5 and the volume of the closed space formed on the inner side of the orbiting scroll scroll 5 are minimum. 9e and 10e are closed spaces at this time. When the revolution advances from this point, the winding start portions of the fixed scroll spiral body 2 and the orbiting scroll spiral body 5 separate, and the two sealed spaces 9e, 10e become one. The closed space formed inside the orbiting scroll spiral body 5 communicates with the discharge port 7 immediately after the formation of the minimum closed space 10e, but the closed space formed outside the orbiting scroll spiral body 5 does not. , So that the volume ratio (volume at the time of completion of suction / volume at the time immediately before discharge) is substantially equal to that of the closed space formed inside, the circular counterbore 8 serving as a fluid passage is connected to the discharge port 7 earlier. Therefore, the pressure imbalance immediately before the discharge in both spaces can be corrected. This is effective in reducing noise and vibration due to pressure imbalance when the discharge ports of both spaces are communicated.

FIG. 3 shows the main part of the discharge port of the scroll compressor according to the present invention. The closed space 9 formed on the outer side of the orbiting scroll spiral body 5 is in a state immediately before being communicated with the discharge port 7 by the circular counterbore 8 serving as a fluid passage. At this time, the volume of the innermost chamber 11 surrounded by the fixed scroll spiral body 2 and the orbiting scroll spiral body 5 is not zero, but since this volume is very small, the loss due to the re-expansion of the gas in this volume. Can be kept small. Further, the machining of the circular counterbore that serves as the fluid passage is very simple.

FIG. 4 shows the main part of the discharge port of another scroll compressor according to the present invention. Instead of the circular counterbore 8 serving as the fluid passage in FIG. 3, a groove 13 serving as the fluid passage is provided.
Is provided. Although the shape of the fluid passage is different, the same effect as in FIG. 3 is obtained.

FIG. 5 shows a main part of a discharge port of another scroll compressor according to the present invention. By displacing the discharge port position in FIGS. 3 and 4 toward the fluid passage side and increasing the diameter of the discharge port, the discharge port 7 also serving as the fluid passage shown in FIGS. 3 and 4 is shown. Similar to FIGS. 3 and 4, the re-expansion loss can be suppressed to be small. Further, this is a simpler method as compared with FIGS. 3 and 4 as a means for correcting the pressure imbalance during the discharge of the two closed spaces.

[0020]

According to the present invention, the re-expansion loss can be suppressed to be small by forming the spiral body shape in which the volume of the innermost chamber surrounded by the fixed scroll spiral body and the orbiting scroll spiral body becomes zero. it can.

Further, since the means for early communicating the closed space formed on the outer side of the orbiting scroll scroll with the discharge port is a fluid passage such as a spot facing provided on the fixed scroll end plate, the processing is easy.

[Brief description of drawings]

FIG. 1 is a plan view of a spiral portion of a scroll compressor according to the present invention.

FIG. 2 is a plan view showing a state change of a scroll body of the scroll compressor according to the present invention.

FIG. 3 is a plan view of a main part of a discharge port of the scroll compressor according to the present invention.

FIG. 4 is a plan view of a main part of a discharge port of another scroll compressor according to the present invention.

FIG. 5 is a plan view of a main part of a discharge port of another scroll compressor according to the present invention.

FIG. 6 is a sectional view of the scroll compressor according to the present invention.

[Explanation of symbols]

1 ... Fixed scroll, 2 ... Fixed scroll spiral body, 4 ...
Orbiting scroll, 5 ... Orbiting scroll spiral body, 7 ... Discharge port, 8 ... Circular counterbore that serves as a fluid passage.

Claims (1)

[Claims] 1. A fixed scroll having a spiral body and an orbiting scroll are engaged with each other so that the orbiting scroll revolves around the fixed scroll without rotating, and the shape of the spiral body is a fixed scroll. The volume of the innermost chamber surrounded by the spiral body and the orbiting scroll spiral body becomes zero, and the fixed scroll spiral body has a large wrap angle within a range not exceeding 180 degrees than the wrap angle of the orbiting scroll spiral body. The fixed scroll or the end plate of the orbiting scroll, the fluid passage having a volume ratio of each of the enclosed space formed outside the orbiting scroll spiral body and the enclosed space formed inside the orbiting scroll spiral body is substantially the same. A scroll compressor, which is provided in the.