JPH10110687A - Scroll compressor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a wide operation range including a low speed operation range,
Provided is a high-efficiency scroll compressor that does not cause a compression leakage operation. SOLUTION: An electric motor 9 and a compression mechanism 2 are provided in a closed container.
The compression mechanism unit 2 controls the rotational force of the fixed scroll 3, the orbiting scroll 4, and the electric motor 9 by engaging the spiral wraps 3a, 4a on the base plates 3b, 4b to form the compression chamber 5. It has a crankshaft 6 for transmitting and rotating the orbiting scroll 4, and a frame 7 coupled to the fixed scroll 3 and supporting the crankshaft 6. The thickness of the base plate 4 b of the orbiting scroll 4 sandwiched between the fixed scroll 3 and the frame 7. A difference g between a dimension D and a dimension S of a step 7c between a surface of the frame 7 contacting the fixed scroll 3 and an inner surface 7b of the base plate 4b serving as a seating surface is set to 5 to 25 μm.

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 suitable for improving efficiency in a wide operating range including a low speed operating range. Used as a machine.

[0002]

2. Description of the Related Art A conventional general scroll compressor will be described with reference to FIG. FIG. 2 is a longitudinal sectional view of a conventional general scroll compressor. In FIG. 2, 1
Is a closed container, 2 is a compression mechanism, 3 is a revolving scroll, 3
a is the spiral wrap of the orbiting scroll, 3b is the base plate of the orbiting scroll, 4 is the fixed scroll, 4a is the spiral wrap of the fixed scroll, 4b is the base plate of the fixed scroll,
Reference numeral 6 denotes a crankshaft, 6a denotes an eccentric portion thereof, 6b denotes an oil supply passage provided at the axis of the crankshaft 6, and 7 denotes a fixed scroll 3.
A frame having a bearing 7a for rotating the crankshaft 6 in combination with the motor 9; an electric motor unit 9 comprising a rotor 9a and a stator 9b; and 13, an Oldham relating to a rotation preventing member for preventing rotation of the orbiting scroll and causing orbital movement. It is a ring.

[0003] In the conventional scroll compressor shown in FIG. 2, a compression mechanism section 2 and an electric motor section 9 are housed in a closed container 1 by being connected via a crankshaft 6. The compression mechanism 2 forms a compression chamber 5 by the fixed scroll 3 and the orbiting scroll 4 meshed with the spiral wraps 3a and 4a inside. Further, the orbiting scroll 4 is constituted by an Oldham ring 13 which is a rotation preventing member of the orbiting scroll 4 and a frame 7 connected to the fixed scroll 3. The motor unit 9 is connected to a rotatable crankshaft 6 via a bearing 7 a of the frame 7.

The fixed scroll 3 has a suction port 10 for sucking the refrigerant gas and a suction gas for moving the suctioned refrigerant gas to the center by the orbiting motion of the orbiting scroll, reducing the volume and compressing the compressed gas, and discharging the compressed gas into the sealed container. It has an outlet 3c. The orbiting scroll 4 has a hole (intermediate pressure hole 4 c) for communicating a room (compression chamber 5) in the middle of the compression stroke with a back pressure chamber 15 formed on the back surface of the orbiting scroll 4. Is controlled so as to have a constant pressure ratio with respect to the suction pressure and a pressure intermediate between the suction pressure and the discharge pressure.
With this intermediate pressure, the orbiting scroll 4 is levitated so that the orbiting scroll 4 can be operated in contact with the fixed scroll 3.

At this time, the fixed scroll 3 and the frame 7
Between the thickness of the base plate 4b of the base plate 4b of the orbiting scroll 4 and the step size between the surface of the frame 7 in contact with the fixed scroll 3 and the inner surface of the frame serving as the seat surface of the base plate 4b. The difference was set to 20 to 50 μm in consideration of normal processing accuracy. In addition, the orbiting scroll 4 may be subjected to a familiar surface treatment in order to suppress leakage between the plurality of compression chambers 5. Furthermore, in this structure, it is not necessary to consider the deformation of the frame 7 of about several μm when the compression mechanism 2 is fixed to the closed vessel 1 by welding.

[0006]

However, the structure of the conventional scroll compressor has the following problems. 2. Description of the Related Art In recent room air conditioners, demands for energy saving in addition to comfort are increasing, and there is an urgent need to improve efficiency in a wide operating range. In the conventional intermediate pressure control (back pressure control) method, as described in the related art, the gap between the base plate of the orbiting scroll 4 sandwiched by the fixed scroll 3 and the frame 7, that is, the base plate 4b of the orbiting scroll 4 The difference between the thickness dimension of the base plate 4b and the step size between the surface of the frame 7 in contact with the fixed scroll 3 and the inner surface of the frame serving as the seating surface of the base plate 4b is determined in consideration of normal machining accuracy by 20%. Usually, it is set to about 50 μm.

However, in order to cover a wide range of operation in order to meet the needs of comfort, the orbiting scroll 4 fitted to the eccentric portion 6a of the crankshaft 6 is overturned by the orbiting scroll 4 by a compression action that meshes with the fixed scroll 3. It has been found that a moment acts to cause the orbiting scroll 4 to move away from the fixed scroll 3, causing a compression leakage operation and possibly causing a decrease in efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a high-efficiency, compression-leakage operation in a wide operation range including a low-speed operation range. Another aspect of the present invention is to provide a scroll compressor. Another object of the present invention is to provide a scroll compressor which can be mounted on, for example, a room air conditioner, which is a product, and which can be a product that is comfortable and consumes less power.

[0009]

According to a first aspect of the present invention, there is provided a scroll compressor in which a motor and a compression mechanism connected to the motor are housed in a closed container. The compression mechanism has a spiral wrap on each base plate, and engages with each wrap to form a compression chamber and a orbiting scroll. A rotation preventing member for blocking and orbiting, a crankshaft for transmitting the rotational force of the electric motor to rotate the orbiting scroll, and a frame having a bearing coupled to the fixed scroll and rotating the crankshaft; In a scroll compressor configured to push up the back surface of the orbiting scroll and press against the fixed scroll to compress the fixed scroll, the fixed scroll and the scroll The difference between the thickness of the base plate of the orbiting scroll base plate sandwiched between the base plate and the step difference between the surface of the frame in contact with the fixed scroll and the inner surface of the frame serving as the seat surface of the base plate, It is set to 5 to 25 μm.

In order to achieve the above object, a second configuration of the scroll compressor according to the present invention is to house an electric motor and a compression mechanism connected to the electric motor in a closed container. The compression mechanism section has a spiral wrap on each base plate, and engages with each wrap to form a compression chamber and a orbiting scroll. A rotating shaft for transmitting rotation force of the electric motor to rotate the orbiting scroll, and a frame having a bearing coupled to the fixed scroll and rotating the crankshaft. Scroll pressure with a familiar surface treatment that pushes up the back of the orbiting scroll and presses against the fixed scroll to compress A thickness dimension of the base plate of the orbiting scroll sandwiched between the fixed scroll and the frame, and a surface of the frame in contact with the fixed scroll and an inner surface of a frame serving as a seating surface of the base plate. The difference between the step size and the step size is set to 5 to 25 μm before performing a surface treatment that is familiar to the orbiting scroll.

When the orbiting scroll is subjected to a familiar surface treatment, the familiar surface treatment layer is usually 5 to 15 μm, that is, 10 to 30 μm on both sides of the orbiting scroll base plate. The compressor cannot be assembled. Do not attach a surface treatment layer to the back surface of the orbiting scroll that does not require familiarity to enable assembly by masking or the like, or remove the surface treatment layer on the back surface of the orbiting scroll after surface treatment, and set the wrap side of the orbiting scroll. The assembly can be made possible by forcibly adjusting the surface treatment layer attached to the plate during assembly of the compressor.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a sectional view of a main part showing a gap between a fixed scroll and a base plate portion of an orbiting scroll sandwiched by a frame of a scroll compressor according to an embodiment of the present invention, and FIG. 2 is a conventional general scroll compressor. 3 is a longitudinal sectional view of another general scroll compressor, and FIG. 4 is a sectional view of a main part showing a detailed structure of a back pressure control valve used in the scroll compressor of FIG. , FIG.
Is a plan view showing a cross section of a compression mechanism section of the scroll compressor, and FIG. 6 is a diagram showing a relationship between a gap between base plates of the orbiting scroll and a volumetric efficiency. In each drawing, the same parts are denoted by the same reference numerals.

The scroll compressor according to the present embodiment is the same as the general scroll compressor shown in FIGS. 2 to 4 except that a gap g of the orbiting scroll base plate shown in FIG. 1 is formed. As shown in FIGS. 2, 3, and 5, the scroll compressor of the present embodiment includes a compression mechanism 2 and an electric motor 9 in a closed container 1.
And are stored.

The compression mechanism 2 forms a compression chamber 5 by combining the fixed scroll 3 and the orbiting scroll 4 having spiral wraps 3a and 4a with the wraps 3a and 4a, respectively. 2 is an electric motor 9 for driving the compression mechanism 2 via the crankshaft 6
It is connected to. The compression mechanism 2 further includes an Oldham ring 13 for preventing rotation of the orbiting scroll 4 and causing the orbiting scroll to perform a revolving motion, and the fixed scroll 3 and a closed vessel 1.
And a frame 7 fixed by welding. A main bearing 7a for slidably supporting the crankshaft 6 connected to the electric motor 9 is formed on the frame 7.

The scroll compressor shown in FIGS.
A suction port 10 is provided at an outer peripheral portion of the closed container 1. The refrigerant gas is sucked from the suction port 10, and the compression chamber 5 formed by the fixed scroll 3 and the orbiting scroll 4 is moved to the center to increase the volume. The refrigerant gas is reduced to compress the refrigerant gas, and the high-pressure gas is discharged from the discharge port 3c at the center of the fixed scroll 3 into the closed container 1. Wrap 3a,
There are always a plurality of compression chambers 5 formed by meshing the compression chambers 4a. Further, the fixed scroll 3 is provided with a release valve 11 for releasing the pressure when the pressure in the compression chamber 5 becomes excessively compressed.

Further, on the back of the orbiting scroll 4, there is formed a back pressure chamber 15 controlled to a pressure intermediate between the suction pressure and the discharge pressure for pressing the orbiting scroll 4 against the fixed scroll 3 to compress the gas. I have. Here, there are several means for controlling the back pressure. For example, as described in the prior art, a small intermediate pressure hole 4c for communicating the compression chamber 5 and the back pressure chamber 15 is provided in the base plate 4b of the orbiting scroll 4 shown in FIG. There is a method of controlling the back pressure chamber 15 with a constant pressure ratio.

As another means of back pressure control, FIG.
There is a method of providing a back pressure control valve 14 on the fixed scroll 3 as shown in FIG. The detailed configuration of the back pressure control valve 14 is shown in FIG.
Shown in The back pressure control valve 14 shown in FIGS. 3 and 4 includes a seal member 18 that blocks off the discharge pressure side, a spring 17 that controls the back pressure chamber 15 and the suction chamber 16 to a constant pressure, and a back pressure chamber 1.
5 and a plate 19 for opening and closing the suction chamber 16.

Here, when the pressure in the back pressure chamber 15 becomes larger than the suction pressure and the force of the spring 17, the plate 19 is pushed up, and the back pressure chamber 15 and the suction chamber 16 communicate with each other through the communication hole 20 so as to communicate with the back pressure chamber 15. Pressure decreases. When the pressure in the back pressure chamber 15 decreases, the force of the suction chamber 16 and the spring 17 exceeds the force on the back pressure chamber side, and the plate 19 moves the back pressure chamber 15 and the suction chamber 1.
Block 6 Further, since the back pressure chamber 15 is communicated with the oil sump 8 at the inner bottom of the sealed container 1 on the discharge pressure side via the oil supply passage 6b while being depressurized by the swivel bearing 4d or the main bearing 7a, the pressure always rises. Trying to. This increase in pressure is controlled by the operation of the back pressure control valve 14 so that the back pressure chamber 15 has a constant pressure difference with respect to the suction pressure.

As described earlier in the section [Problems to be Solved by the Invention], in the conventional general structure, the fixed scroll 3
And the base plate 4 of the orbiting scroll 4 sandwiched by the frame 7
The gap of the portion b, that is, the base plate 4 of the orbiting scroll 4
b, the thickness D of the base plate 4b and the frame 7
The difference between the dimension S of the step 7c between the surface in contact with the fixed scroll 3 and the frame inner surface 7b serving as the seating surface of the base plate 4b (g shown in FIG. 1) is 20 to
Usually, it is set to about 50 μm.

However, today, in order to meet a need for comfort, the orbiting scroll 4 separates from the fixed scroll 3 due to a capsizing moment acting on the orbiting scroll by a compressing action to cover a wide operating area, thereby causing a compression leakage operation. There is a fear of getting worse.

In the embodiment of the present invention, the orbiting scroll 4 sandwiched between the fixed scroll 3 and the frame 7 shown in FIG.
The difference g between the thickness D of the base plate 4b of the base plate 4b and the dimension S of the step 7c between the surface of the frame 7 in contact with the fixed scroll 3 and the frame inner surface 7b serving as the seat surface of the base plate 4b. By setting the (gap) to 5 to 25 μm, compression leakage due to an overturning moment acting on the orbiting scroll due to the compression action is prevented, and a reduction in efficiency due to compression leakage is improved. As a result, the present invention provides a scroll compressor that responds to needs in recent years that value comfort and that exhibits high efficiency in a wide operating range.

FIG. 6 shows the fixed scroll 3 in the present embodiment by taking the above-mentioned gap g (μm) on the horizontal axis and the volumetric efficiency (%) as a parameter of the ratio of compression leakage on the vertical axis.
Plate 4b of orbiting scroll 4 sandwiched between frame and frame 7
The difference g between the thickness D of the base plate 4b and the dimension S of the step 7c between the surface of the frame 7 in contact with the fixed scroll 3 and the inner surface 7b of the base plate 4b serving as the seating surface is 5 to 5. The result of having confirmed the compression performance by setting to 25 micrometers is shown.

As is apparent from FIG. 6, the volumetric efficiency sharply decreases when the gap g becomes larger than 25 μm.
If the gap g is less than 5 μm, the assembling cannot be performed. If the assembling is forcibly performed, the orbiting scroll cannot be turned, the sliding loss increases, and the efficiency of the compressor decreases. Therefore, assembling the above gap g with 5 to 25 μm leads to an improvement in efficiency without causing performance deterioration such as compression leakage even when the overturning moment acting on the orbiting scroll due to the compression action in a low speed operation region or the like becomes large. Things.

The orbiting scroll 4 according to the present embodiment is subjected to a familiar surface treatment that suppresses leakage loss from a plurality of compression chambers 5 and contributes to higher efficiency of the scroll compressor. There are many things you can find.
For this reason, the gap (g in FIG. 1) between the base plate 4b of the orbiting scroll 4 which is conventionally slidably sandwiched between the fixed scroll 3 and the frame 7 is set to 20 to 5 before the surface treatment of the orbiting scroll.
It had to be as wide as 0 μm. At this time, the familiar surface treatment layer is usually 5 to 15 μm, that is, 10 to 30 μm on both sides of the orbiting scroll base plate. However, since the surface layer is soft, more than half of the surface treatment layer is peeled off by the operation of the compressor. . For this reason, although the orbiting scroll 4 is operated by being pushed up at the intermediate pressure, the gap g shown in FIG. 1 is widened, and the orbiting scroll 4 separates from the fixed scroll 3 due to the overturning moment due to gas compression and the like, resulting in a compression leakage operation. It was easy and caused a decrease in efficiency.

Therefore, in order to prevent the orbiting scroll 4 from separating from the fixed scroll 3 and to provide a highly efficient scroll compressor, the fixed scroll 3 and the frame 7 are prevented from moving.
And a step between a thickness dimension D of the base plate 4b of the base plate 4b of the orbiting scroll 4 and a frame inner surface 7b serving as a seat surface of the base plate 4b and a surface of the frame 7 in contact with the fixed scroll 3. The object of the present invention is achieved by setting the difference g from the dimension S of 7c to 5 to 25 μm before performing the surface treatment which is familiar to the orbiting scroll 4.

In order to achieve this object, it is necessary to solve the problem that the compressor cannot be assembled due to the presence of the surface treatment layer. In order to make this assembly possible, a surface treatment layer is not attached to the back surface of the orbiting scroll 4 which does not require familiarity by masking or the like, or the surface treatment layer on the back surface of the orbiting scroll 4 is removed after the surface treatment, and This problem can be solved by assembling the surface treatment layer attached to the base plate 4b on the wrap 4a side of the orbiting scroll 4 by forcibly adjusting the surface treatment layer during assembly of the compressor.

Further, an embodiment to be considered in the present invention will be described. In FIGS. 2 and 3, reference numeral 1 a denotes a welded portion when the compression mechanism 2 is welded and fixed to the closed container 1. The center position of the welding portion is set to the base plate 4 of the orbiting scroll 4.
It is desirable that the back surface of b is located on the side opposite to the pump with respect to the surface (seat surface 7b: see FIG. 1) in contact with the frame 7.
Thereby, deformation of the frame 7 due to welding work and deviation of the gap g in the base plate 4b of the orbiting scroll 4 sandwiched between the fixed scroll 3 and the frame 7 can be suppressed.

[0028]

As described above in detail, according to the present invention, it is possible to provide a high-efficiency scroll compressor which does not cause a compression leakage operation in a wide operation region including a low speed operation region. . Further, according to the present invention, it is possible to provide a scroll compressor that can be mounted on, for example, a room air conditioner that is a product and that can be a product that is comfortable and consumes less power.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing a gap between a fixed scroll and a base plate portion of an orbiting scroll sandwiched by a frame of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional general scroll compressor.

FIG. 3 is a longitudinal sectional view of another general scroll compressor.

FIG. 4 is a sectional view of a main part showing a detailed structure of a back pressure control valve used in the scroll compressor of FIG. 3;

FIG. 5 is a plan view showing a cross section of a compression mechanism of the scroll compressor.

FIG. 6 is a diagram illustrating a relationship between a gap between base plates of the orbiting scroll and a volumetric efficiency;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Closed container, 2 ... Compression mechanism part, 3 ... Fixed scroll,
4 orbiting scroll, 3a, 4a ... wrap, 3b, 4b
... Base plate, 5 ... Compression chamber, 6 ... Crank shaft, 7 ... Frame,
7a: Main bearing, 9: Electric motor unit, 10: Suction port, 13: Oldham ring, 14: Back pressure control valve, 15: Back pressure chamber, 16
... Suction chamber, g ... Gap.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takehiro Akizawa 800, Tomita, Odai-machi, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Inside the Cooling and Refrigerating Business Dept., Hitachi, Ltd. Hitachi Tochigi Electronics Co., Ltd.

Claims (5)

[Claims] An electric motor and a compression mechanism connected to the electric motor are housed in an airtight container, wherein the compression mechanism has a spiral wrap on each base plate. A fixed scroll and an orbiting scroll that form a compression chamber by engaging the wraps of the above, a rotation preventing member for preventing the orbiting of the orbiting scroll and making an orbital motion, and a crank that transmits the rotational force of the electric motor to rotate the orbiting scroll A scroll compressor comprising: a shaft; and a frame having a bearing coupled to the fixed scroll and rotating the crankshaft, wherein a rear surface of the orbiting scroll is pushed up and pressed against the fixed scroll to be compressed. And the thickness of the base plate of the base plate of the orbiting scroll sandwiched between the frame and the frame, The difference between the step size of the surface in contact with the fixed scroll and the inner surface of the frame serving as the seating surface of the base plate is 5 to 5.
A scroll compressor characterized in that it is set to 25 μm. 2. An electric motor and a compression mechanism connected to the electric motor are housed in a closed container, wherein each of the compression mechanisms has a spiral wrap on each base plate. A fixed scroll and an orbiting scroll that form a compression chamber by meshing the wraps; a rotation preventing member for preventing the orbiting of the orbiting scroll from rotating; and a crank that transmits the rotational force of the electric motor to rotate the orbiting scroll. A shaft having a shaft coupled to the fixed scroll and having a bearing for rotating the crankshaft; applying a surface treatment familiar to the orbiting scroll; pushing up the rear surface of the orbiting scroll and pressing against the fixed scroll. In the scroll compressor configured to compress, the orbiting scroll sandwiched between the fixed scroll and the frame. The difference between the thickness of the base plate in the base plate and the difference in level between the surface of the frame in contact with the fixed scroll and the inner surface of the frame serving as the seat surface of the base plate is compatible with the orbiting scroll. A scroll compressor having a thickness of 5 to 25 [mu] m before surface treatment. 3. The method according to claim 2, wherein when the orbiting scroll is subjected to a familiar surface treatment, the orbiting scroll is masked so that a surface treatment layer is not attached to the back surface of the orbiting scroll which does not need to be familiar. Scroll compressor. 4. A surface treatment layer on the back side of the orbiting scroll after removing the surface treatment layer familiar to the orbiting scroll and attaching to the base plate on the lap side of the orbiting scroll. 3. The scroll compressor according to claim 2, wherein the scroll compressor is forcibly adapted during assembly of the compressor. 5. When the compression mechanism is welded and fixed to the closed container, the center of the weld is set so that the back surface of the base plate of the orbiting scroll is on the side opposite to the pump from the surface in contact with the frame. The scroll compressor according to any one of claims 1 to 4, wherein