JPH06167285A - Scroll compressor - Google Patents

Abstract

PURPOSE:To enable stable compression operation by arranging at a specified position an opening of a communication passage between a back pressure chamber and a low pressure chamber on the side of the back pressure chamber, thereby securing the pressure inside the back pressure chamber, and speedily reccovering an original condition even when a revolving scroll is once separated from a fixed scroll. CONSTITUTION:When motors 7, 8 are operated and a crank shaft 5 is rotated, a revolving scroll 3 revolves without rotating by means of an Oldham's ring 6. Cooling medium gas is suctioned by a suction pipe 9, compressed, and discharged to an inside of a sealed vessel 1 from a discharge port 20. The gas is then discharged from a discharge pipe 21 after cooling the motors 7, 8. A valve 16 is lifted for communication of a communication passage 18 when required, so that the cooling medium gas flows from a back pressure chamber 13 to a low pressure chamber 15, and a required amount of oil is secured. In this case, an opening of the communication passage 18 on the side of the back pressure is blocked within a specified rotational angle range in the revolving scroll 3. The pressure inside the back pressure chamber is increased for securing normal compression operation.

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 in particular to a refrigerator such as an air conditioner or a freezer, for expanding the operating condition range with a simple structure and improving efficiency. The present invention relates to a suitable scroll compressor.

[0002]

2. Description of the Related Art In recent years, scroll compressors, which are in principle advantageous for reducing vibration and noise, have been adopted.
Furthermore, as a technology that is advantageous for higher efficiency and refueling, the above-mentioned back chamber is maintained at an intermediate pressure between suction pressure and discharge pressure.
There is a technique described in 57-23793 and a technique described in JP-A-61-89990, which further expands the control range of the pressure of the back pressure chamber to expand the operating range.

[0003]

In the above-mentioned prior art, the swirl scroll is pressed against the fixed scroll with an appropriate force, and the pressure in the back pressure chamber is controlled even at low speed and low pressure, so that the discharge pressure It is possible to refuel using the differential pressure. However, if the swirl scroll is separated from the fixed scroll for some reason while the back pressure control valve is open at low speed and low pressure, the axial gap at the tip of the wrap increases and compression efficiency decreases and back pressure decreases. Since 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 rise and the state becomes so-called idle.

The present invention eliminates the above-mentioned drawbacks, and even if the turning scroll is separated from the fixed scroll, the scroll quickly returns to its original state and enables stable operation. To provide a compressor.

[0005]

In order to achieve the above object, the structure of the invention relating to the scroll compressor of the present invention is as follows.
An electric motor and a compression mechanism portion connected to the electric motor by a crankshaft are housed in a closed container, and the compression mechanism portion has at least two spiral wraps each standing upright on a plate. The scrolls are engaged with each other with the wraps inside, and one of the scrolls makes a swivel motion with respect to the other scroll in a state in which the rotation of the scroll is blocked. A scroll having a back chamber on the side opposite to the wrap, and having a communication passage containing a valve device for communicating between the back chamber and the low pressure chamber of the compression mechanism section in the other scroll (fixed scroll). -In the compressor, the opening to the back chamber is located at a position of the fixed scroll facing the wrap side plate outer plane of the swivel scroll, and at the plate outer plane. It is provided at a position where you can open and close That.

[0006]

The function of the above technical means is as follows.

According to the present invention, in the scroll compressor having a communication passage containing a valve device for connecting and disconnecting the back chamber and the low pressure chamber of the compression mechanism portion in the other scroll (fixed scroll), The opening to the back room is fixed,
It was provided at a position facing the outer plane of the lap side plate of the orbiting scroll and at a position where the opening can be opened and closed in the outer plane of the plate. Since the valve device that shuts off the communication operates with a pressure difference, once the swivel scroll separates from the fixed scroll, the axial gap at the tip of the wrap becomes large and the compression efficiency decreases, and at the same time 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 rise, and the state becomes so-called idle. In the structure according to the present invention, since the opening is provided at a position facing the wrap-side plate outer surface of the orbiting scroll and the opening can be opened and closed on the plate outer surface, a constant angle during one rotation. The opening closes and blocks the flow of gas from the back pressure chamber to the low pressure chamber. Therefore, even if the pressure in the back pressure chamber rises and the turning scroll temporarily separates, it can be quickly restored. The closing angle can be arbitrarily selected depending on the position of the opening.

[0008]

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

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

The electric motor portion is composed of a stator 7 and a rotor 8. The stator 7 is fixed to the closed container 1 by shrink fitting, and the rotor 8 is fixed to the crankshaft 5 by press fitting or the like.

The outer peripheral portion of the frame 4 is fixed to the closed container 1 and has a bearing for receiving the rotation of the crankshaft 5. A swivel scroll 3 is rotatably attached to the eccentric part of the crankshaft 5, and an Oldham ring 6 is slidably mounted in a groove provided in the frame 4 and a groove provided in the swivel scroll 3. It is provided to prevent the turning scroll 3 from rotating.

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

The shaft end of the crankshaft 5 opposite to the eccentric part is supported by a sub bearing 11, and the sub bearing 11 is a closed container 1.
It is attached to a support plate 12 fixed to. on the other hand,
The back chamber space 13 formed by the frame 4 and the swirl scroll 3 is determined by the position of the back pressure hole 24 that connects the compression chamber and the back chamber space 13 to any pressure from suction pressure to discharge pressure. Since it is leaning and the inside of the closed container 1 is the discharge pressure, the refrigerating machine oil is supplied to each sliding portion via the oil hole 14 provided in the crankshaft 5 due to the differential pressure. Further, the fixed scroll 2 is provided with a communication passage 18 which has a built-in valve device including a valve 16 and a spring 17 for connecting and disconnecting the rear chamber 13 and the low pressure chamber 15 of the compression mechanism section. A stopper 19 is arranged 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 crankshaft 5 rotates, and the orbiting scroll 3 is eccentrically rotated (revolved) by the action of the Oldham ring 6 without rotating.
To do. Due to the revolution of the orbiting scroll 3, the refrigerant gas sucked 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 discharged refrigerant gas cools the electric 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.
Along with this, description will be made with reference to FIGS.

The valve 16 receives the discharge pressure from the upper part, the spring 17, the low pressure chamber pressure and the back pressure chamber pressure from the lower part, and the resultant force of these causes the communication state as shown in FIG.
The cutoff state is as shown in. Working pressure is spring 1
It can be set arbitrarily by changing the strength of 7. When the pressure condition is sufficient to obtain the required amount of oil supply, the pressure difference between the discharge pressure and the back pressure chamber is in the cutoff state, but the discharge pressure decreases and the pressure difference is insufficient to obtain the required amount of oil supply. Then, as shown in FIGS. 3 to 4, the valve 16 rises and the communication passage 18 communicates. As shown in FIG. 3, the back pressure chamber space 13 and the low pressure chamber 15 are connected to each other through the communication passage 18, the pore 22 and the groove 23 as shown in FIG. 3, and the refrigerant gas flows from the back pressure chamber space 13 to the low pressure chamber 15 to generate the back pressure. The pressure in the chamber space 13 is reduced and the required amount of oil can be obtained. Further, the opening on the back pressure chamber side of the communication passage 18 is a fixed angle of one rotation on the outer flat surface of the wrap side plate of the swirl scroll 3, and the opening is closed to allow the flow of gas from the back pressure chamber to the low pressure chamber. Cut off. Therefore, even if the pressure in the back pressure chamber rises and the turning scroll temporarily separates, the pressure can be quickly restored, and a normal compression operation can be performed.

Further, as shown in FIGS. 6 to 7, it is possible to easily change the opening / closing angle during one rotation by changing the diameter or the position of the recess without changing the angle of the communication passage 18 by providing the recessed recess. Can be selected. Furthermore, when using a material such as aluminum that has a relatively small elastic coefficient, such as aluminum, for the swivel scroll, the operating range is expanded to the low pressure ratio side when the material that is susceptible to deformation during high pressure ratio operation is used. It is easy to achieve wide range.

[0019]

According to the present invention, it is possible to operate in a region where the ratio of the condensation pressure to the evaporation pressure of the air conditioner is smaller and to improve the annual energy efficiency. Also, the pressure in the back pressure chamber can be set to the minimum necessary for efficient operation with less leakage by pressing the swivel scroll against the fixed scroll, and friction loss is also minimized. It leads to efficiency improvement. In addition, it is possible to secure a necessary and sufficient amount of oil supply, which is also effective in improving reliability.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a scroll compressor according to an 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.

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

FIG. 5 is a diagram showing a state of the control valve when the communication passage is blocked.

FIG. 6 is a view in which a recess is provided in the opening of the communication passage.

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

[Explanation of symbols]

1 ... airtight container, 2 ... fixed scroll, 3 ... swivel scroll
LE, 4 ... Frame, 5 ... Crankshaft, 6 ... Oldham ring, 7 ... Stator, 8 ... Rotor, 9 ... Suction pipe, 11 ...
Secondary 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 ... discharging hole, 21 ... discharging pipe, 22 ... pore, 23 ... groove, 24 ... back pressure hole.

Claims (3)

[Claims] 1. A hermetically-sealed container for accommodating an electric motor and a compression mechanism portion connected to the electric motor by a crankshaft, wherein the compression mechanism portion has at least a spiral shape which stands upright on a plate. Two scrolls having a wrap are engaged with each other with the wraps inside, and one scroll makes a swivel motion with respect to the other scroll in a state where rotation of the scroll is blocked. Is provided with a back chamber on the side opposite to the wrap of the scroll, and the communication passage containing the valve device for communicating and blocking the back chamber and the low pressure chamber of the compression mechanism part is connected to the other scroll (fixed scroll). In the scroll compressor provided in (1) above, the opening to the back chamber is located at a position facing the wrap side plate external surface of the swivel scroll of the fixed scroll and outside the plate. At 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 in the opening to the back chamber. 3. The scroll compressor according to claim 1 or 2, wherein the material of the orbiting scroll is an aluminum material.