JP3252495B2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly to a scroll compressor for use in an air conditioner, a refrigerator or the like. It relates to a suitable scroll compressor.

[0002]

2. Description of the Related Art In recent years, scroll compressors which are advantageous in principle for reducing vibration and noise of compressors have been employed.
Furthermore, as a technology that is advantageous for higher efficiency and lubrication, the above rear chamber is maintained at an intermediate pressure between suction pressure and discharge pressure.
There is a technique described in Japanese Patent Application Laid-Open No. 57-23899 and a technique described in Japanese Patent Application Laid-Open No. 61-89990 in which the control range of the pressure in the back pressure chamber is further expanded to expand the operation range.

[0003]

In the above prior art, the turning scroll is pressed against the fixed scroll with an appropriate force, and the pressure in the back pressure chamber is controlled even at a low speed and a low pressure, so that the discharge pressure is controlled. Refueling using differential pressure is possible. However, if the swivel scroll is separated from the fixed scroll for some reason with the back pressure control valve opened at low speed and low pressure, the gap in the axial direction at the tip of the lap will increase, reducing the compression efficiency and reducing the back pressure. Since the gas continuously flows from the chamber to the low-pressure chamber through the opened back pressure control valve, the pressure in the back pressure chamber does not increase, and a state close to a so-called idle rotation occurs.

The present invention solves the above-mentioned drawbacks, and even if a situation occurs in which the turning scroll is separated from the fixed scroll, the scroll quickly returns to the original state and enables stable operation. A compressor.

[0005]

Means for Solving the Problems In order to achieve the above object, the structure of the invention related to the scroll compressor of the present invention is as follows.
An electric motor and a compression mechanism connected to the electric motor by a crankshaft are housed in a closed container, wherein the compression mechanism has at least two spiral wraps each standing upright on a base plate. The scrolls are engaged with each other with the wraps on the inside, and one of the scrolls makes a swinging movement with respect to the other scroll while the rotation of the scrolls is prevented. A scroll having a rear chamber on a surface opposite to the wrap, and having a communication passage containing a valve device for communicating and blocking the rear chamber and the low-pressure chamber of the compression mechanism in the other scroll (fixed scroll). In the compressor, the opening to the rear chamber is formed at the position of the fixed scroll facing the outer plane of the wrapping side of the slewing scroll, and at the outer side of the stencil. That can be opened and closed That.

[0006]

The operation of the above technical means is as follows.

According to the present invention, there is provided a scroll compressor having a communication passage having a built-in valve in the other scroll (fixed scroll) for opening and closing a rear chamber and a low-pressure chamber of a compression mechanism. Fix the opening to the rear chamber with the scroll
The rotating scroll is provided at a position facing the outer surface of the slab on the lap side and at a position where the opening can be opened and closed by the outer surface of the stencil. Since the above-mentioned valve device for shutting off the communication is operated by the pressure difference, once the swirling scroll is separated from the fixed scroll, the axial gap at the tip of the lap becomes large, the compression efficiency is reduced, and at the same time, the pressure is reduced from the back pressure chamber to the low pressure chamber. Since the gas continuously flows through the opened back pressure control valve, the pressure in the back pressure chamber does not increase, and a state close to a so-called idle rotation occurs. In the structure according to the present invention, the turning scroll is provided at a position opposed to the outer plane of the slab side of the slab and at a position where the opening can be opened and closed by the outer plane of the slab. The opening closes and shuts off the flow of gas from the back pressure chamber to the low pressure chamber. Therefore, even if a situation occurs in which the pressure in the back pressure chamber rises and the turning scroll once separates, it can be quickly restored. The closing angle can be arbitrarily selected depending on the position of the opening.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, the general structure of a scroll compressor according to the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a scroll compressor according to one embodiment of the present invention, in which a compression mechanism section and an electric section are housed in a closed container 1. FIG. The compression mechanism includes a fixed scroll 2, a revolving scroll 3, a frame 4, a crankshaft 5, and an Oldham ring 6 as main components. A suction pipe 9 connected to an external cycle is press-fitted into a suction port of the fixed scroll 2.

The electric motor section includes a stator 7 and a rotor 8. The stator 7 is fixed to the closed casing 1 by shrink fitting or the like, and the rotor 8 is fixed to the crankshaft 5 by press fitting or the like.

The outer periphery of the frame 4 is fixed to the closed casing 1 and has a bearing for receiving rotation of the crankshaft 5. A revolving scroll 3 is rotatably mounted on an eccentric portion of the crankshaft 5, and an Oldham ring 6 is slidably mounted on a groove provided on the frame 4 and a groove provided on the revolving scroll 3. The rotating scroll 3 is provided to prevent the rotation of the rotating scroll 3.

A fixed scroll 2 meshing with the revolving scroll 3 to form a compression chamber is fastened to the frame 4 by bolts 10.

The shaft end of the crankshaft 5 opposite to the eccentric portion is supported by a sub-bearing 11, and the sub-bearing 11 is
Is mounted on a support plate 12 fixed to the support plate 12. on the other hand,
The rear chamber space 13 formed by the frame 4 and the orbiting scroll 3 has a pressure from suction pressure to discharge pressure determined by the position of the back pressure hole 24 communicating the compression chamber and the rear chamber space 13. Since the inside of the closed container 1 is at the discharge pressure, the refrigerating machine oil is supplied to each sliding portion via the oil hole 14 provided in the crankshaft 5 by the differential pressure. Further, the fixed scroll 2 is provided with a communication passage 18 which incorporates a valve device composed of a valve 16 and a spring 17 for interrupting communication between the rear chamber 13 and the low-pressure chamber 15 of the compression mechanism. A stopper 19 is provided above the valve 16.

The general operation of such a scroll compressor will be described.

The rotor 8 receives a rotational force from the stator 7,
The crank shaft 5 rotates, and the orbiting scroll 3 does not rotate by the action of the Oldham ring 6 eccentric rotation (revolution).
I do. As the revolving scroll 3 revolves, the refrigerant gas sucked in from the suction port of the fixed scroll 2 through the suction pipe 8 is gradually compressed in the compression chamber, and is discharged from the discharge hole 20 into the closed container 1. The released refrigerant gas cools the motor unit and is supplied from the discharge pipe 21 to the external cycle.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.
A description will be given with reference to FIGS.

The valve 16 receives the discharge pressure from the upper part, receives the spring 17 and the low pressure chamber pressure and the back pressure chamber pressure from the lower part, and communicates as shown in FIG. 4 or FIG.
The cutoff state is as shown in FIG. Working pressure is spring 1
7 can be arbitrarily set by changing the strength. It is shut off when the pressure difference between the discharge pressure and the back pressure chamber pressure is sufficient to obtain the required lubrication amount, but the discharge pressure drops and the condition is insufficient to obtain the required lubrication amount requiring the differential pressure. Then, as shown in FIGS. 3 and 4, the valve 16 rises and the communication passage 18 passes. As shown in FIG. 3, the back pressure chamber space 13 and the low pressure chamber 15 are connected via the communication path 18, the pores 22, and the grooves 23, and the refrigerant gas flows from the back pressure chamber space 13 to the low pressure chamber 15 as shown in FIG. The pressure in the room space 13 is reduced, and a required refueling amount can be obtained. The opening of the communication passage 18 on the back pressure chamber side is a flat outer surface of the wrapping side plate of the revolving scroll 3, and the opening for a fixed angle of one rotation is closed to prevent the flow of gas from the back pressure chamber to the low pressure chamber. Cut off. Therefore, even if a situation where the pressure in the back pressure chamber rises and the turning scroll once separates occurs, the pressure can be quickly restored, and a normal compression operation can be performed.

Also, as shown in FIGS. 6 and 7, by providing a counterbore-shaped recess, the opening or closing angle during one rotation can be easily changed by changing the diameter or position of the recess without changing the angle of the communication passage 18. Can be selected. Furthermore, when the material of the revolving scroll is aluminum, which has a relatively small elastic coefficient and is easily affected by deformation at the time of high pressure ratio operation, the operating range is expanded to the low pressure ratio side to increase the air conditioning capacity. It is easy to achieve a wide range.

[0019]

According to the present invention, the air conditioner can be operated in a region where the ratio between the condensing pressure and the evaporating pressure is smaller, and the annual energy efficiency can be improved. In addition, the pressure in the back pressure chamber can be set to the minimum necessary for efficient operation with less leakage by pressing the turning scroll against the fixed scroll, and the friction loss can be minimized. It leads to efficiency improvement. In addition, a necessary and sufficient amount of lubrication can be secured, which is effective for improving reliability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll compressor according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a diagram showing a state where an opening of a communication passage is closed.

FIG. 5 is a diagram showing a state of a control valve when a communication passage is shut off.

FIG. 6 is a diagram in which a concave portion is provided in an opening of a communication passage.

FIG. 7 is a sectional view taken along the line CC of FIG. 6;

[Explanation of symbols]

1. Sealed container 2. Fixed scroll 3. Rotating scroll
4 ... frame, 5 ... crankshaft, 6 ... Oldham ring, 7 ... stator, 8 ... rotor, 9 ... suction pipe, 11 ...
Auxiliary bearing, 12: support plate, 13: back pressure chamber space, 14: oil hole, 15: low pressure chamber, 16: valve, 17: spring, 18
... communication passage, 19 ... stopper, 20 ... discharge hole, 21 ... discharge pipe, 22 ... pore, 23 ... groove, 24 ... back pressure hole.

Claims (3)

(57) [Claims] An electric motor and a compression mechanism connected to the electric motor by a crankshaft are housed in a closed container, wherein the compression mechanism has at least a spiral shape standing upright on a platform. Two scrolls having wraps are engaged with each other with the wraps on the inside, and one of the scrolls makes a pivoting motion with respect to the other scroll while rotation is prevented. The other side of the scroll (fixed scroll) is provided with a back passage on the surface opposite to the wrap of the scroll, and a communication passage containing a valve device for shutting off the back passage and the low pressure chamber of the compression mechanism. In the scroll compressor according to (1), the opening to the rear chamber is located at a position facing the outer surface of the fixed scroll on the wrap side of the wrapping side of the slewing scroll. In a position where the opening can be opened and closed on a flat surface Le compressor - scroll, characterized in that digit. 2. The scroll compressor according to claim 1, wherein a counterbore-shaped recess is provided at an opening to said rear chamber. 3. The scroll compressor according to claim 1, wherein the material of said revolving scroll is aluminum.