JP2003214370A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor that is able to improve compressing efficiency by securing necessary cross sectional area of the suction path and reducing leakage area S. <P>SOLUTION: In the rotary compressor 20, a rotor 28 fixed to a rotary shaft 27 rotates eccentrically inside a cylinder room 34. The transferred fluid is introduced from a suction port 37 that is opened on the cylinder room 34 and compressed. Then the fluid pushes open a discharge valve 39 and is discharged from a discharge port 38 that is provided in the cylinder room 34. The sectional form of the suction port 37 is made to noncircular form with the dimension of the rotor 28 in the rotational direction larger than the axial dimension of the rotary shaft 27. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor used, for example, for refrigerant compression of refrigeration equipment and air conditioners.

[0002]

2. Description of the Related Art Conventionally, in a refrigerating apparatus, an air conditioner, etc., a gas refrigerant vaporized in an evaporator is sucked and compressed to a pressure necessary for condensing the high-temperature high-pressure gas refrigerant in a refrigerant circuit. A compressor is used to pump out. A rotary compressor is known as one of such compressors. This rotary compressor includes a cylindrical housing, a motor arranged in the housing, and a fully enclosed rotary compression mechanism that is driven by the motor and compresses a conveyed (compressed) fluid such as a gas refrigerant. Is configured.

As shown in FIG. 7, for example, the rotary compression mechanism 10 includes a rotary shaft 1 joined to a drive shaft of a motor, and a rotor 2 rotatably fitted to the rotary shaft 1 at an eccentric position. The outer peripheral surface of the rotor 2 has a space of circular cross section which is slidably contacted at one location, and the cylinder 3 is inserted into the housing 11 with the rotor 2 arranged in the space. The cylinder 3 is fixed to the upper end surface of the cylinder 3. An upper bearing 4 that rotatably supports the rotating shaft 1 above the rotor 2.
And a lower bearing 5 fixed to the lower end surface of the cylinder 3 and rotatably supporting the rotary shaft 1 below the rotor 2.

The cylinder 3 is opened with a suction port 7 for sucking gas toward a suction chamber formed in a cylinder chamber 6, and the upper bearing 4 is provided with a gas from a compression chamber formed by turning from the suction chamber. A discharge port 8 that discharges the rotor 2 is opened, and the rotor 2 is housed in a cylinder chamber 6 formed by closing a cylinder 3 from above and below by an upper bearing 4 and a lower bearing 5.

The cylinder chamber 6 has a suction chamber provided on one side of the blade and communicating with the suction port 7 when the tip of a blade (not shown) is pressed against the outer peripheral surface of the rotor 2 and a suction chamber on the other side of the blade. It is partitioned into a compression chamber that is provided and communicates with the discharge port 8.

The intake port 7 is opened in the outer peripheral side wall surface of the cylinder chamber 6, and is provided so as to penetrate the cylinder 3 and the housing 11. The suction port 7 has a circular cross section as shown in FIG. 8, and one end of the connection portion of the suction fitting 12 having the same circular cross section is press-fitted into the suction port 7. A suction pipe 13 is connected to the other end of the suction fitting 12. Reference numeral 14 in the figure is an outer pipe welded to the housing 11, and the outer pipe 14 and the suction fitting 12 are brazed.

The discharge port 8 is formed as a circular hole in a plan view penetrating the upper bearing 4, and a discharge valve 9 which is opened when a pressure of a predetermined magnitude or more is released is formed on the upper surface of the discharge port 8. It is provided.

In the rotary compressor having the above-described structure, the sliding contact portion of the rotor 2 on the suction chamber side passes through the suction port 7 to gradually expand the suction chamber and move away from the suction port 7 into the suction chamber. Inhale gas. On the other hand, on the compression chamber side, the sliding portion of the rotor 2 approaches the discharge port 8 while gradually shrinking the compression chamber, and when compressed to a predetermined pressure or higher, the discharge valve 9 opens and gas is discharged from the discharge port 8. Drain.

[0009]

By the way, in the above-described conventional rotary compressor, the outer peripheral surface of the eccentrically rotating rotor 2 and the outer peripheral surface of the rotor 2 are in linear contact with the outer peripheral side wall surface of the cylinder 3. The leakage area S formed between the outer peripheral side wall surface of the cylinder 3 affects the compression efficiency. As shown in FIG. 9, the leak area S is a rectangular shape formed by a minute gap W and a cylinder height H, and in order to reduce the leak amount and improve the compression efficiency, the leak area S is reduced. Is desired to be small. As one means for reducing the leakage area S, the cylinder height H
Can be reduced. Note that there is a limit to the reduction of the gap W due to the problems of wear and seizure.

However, in the case of the rotary compressor, the suction port 7 and the suction pipe 13 are connected by a suction fitting 12, and the suction fitting 12 further introduces gas into the compression chamber of the cylinder chamber 6. It also becomes a road. Therefore, the suction pipe 1 having a circular cross section is provided in the cylinder chamber 6.
In order to connect 3 to each other, both ends of the suction fitting 12 need to have a connecting portion having a circular cross section. Therefore, the sectional shape of the suction port 7 for press-fitting and connecting one connecting portion of the suction fitting 12 also has a circular cross section. .

Under these circumstances, the cylinder height H of the cylinder chamber 6 needs to be determined in consideration of the pressure loss at the time of sucking gas so that the cross-sectional area required for the suction passage can be secured. . That is, since it is necessary to provide the suction port 7 into which the suction fitting 12 having an inner diameter capable of ensuring a sufficient flow passage cross-sectional area can be press-fitted, the cylinder height H of the cylinder chamber 6 has a minimum value depending on the diameter of the suction port 7. The situation is limited.

The present invention has been made in view of the above circumstances, and provides a rotary compressor capable of securing a cross-sectional area required for an intake passage and reducing a leak area S to improve compression efficiency. It is intended to be provided.

[0013]

The present invention adopts the following means in order to solve the above problems. In the rotary compressor according to claim 1, a rotor rotatably fitted to an eccentric portion of a rotary shaft is fixed to a cylindrical cylinder and an upper portion of the cylinder, and the rotary shaft is rotatably supported above the rotor. Eccentrically rotationally moves in a cylinder chamber composed of an upper bearing and a lower bearing which is fixed to the lower portion of the cylinder and rotatably supports a rotating shaft below the rotor, from an intake port opened toward the cylinder chamber. In a rotary compressor that sucks in and compresses a fluid to be conveyed and discharges it by pushing and opening a discharge valve from a discharge port that is also provided in the cylinder chamber, the suction port causes the rotor to rotate more than the axial dimension of the rotary shaft. It is characterized by having a non-circular cross-sectional shape with a large directional dimension.

According to such a rotary compressor, since the cross-sectional shape of the suction port has a non-circular cross-sectional shape in which the size in the rotational direction of the rotor is larger than the size in the axial direction of the rotary shaft, the flow passage in the suction path is blocked. Cylinder height H with the same area
Can be reduced.

In this case, it is preferable that the suction port is connected to the suction pipe through a suction fitting provided with a connecting portion having one of the non-circular cross-sectional shape and the other of the circular cross-sectional shape. This facilitates connection between the suction port (non-circular cross section) of the rotary compressor and the suction pipe (circular cross section). The non-circular cross-sectional shape described above is preferably either an ellipse, an ellipse, a connecting circle, or a shape in which two circles are connected by a rectangle.

[0016]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of a rotary compressor according to the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the rotary compressor 20 has a cylindrical housing 21, a motor 22 arranged in the housing 21, and a hermetically sealed structure that is driven by the motor 22 to compress a gas (a fluid to be transported) of a refrigerant. Type rotary compression mechanism 23
And is configured.

The housing 21 has a hollow cylindrical shape in which a bottom portion 21b and a lid portion 21c are welded and closed above and below a tubular portion 21a. One end of a suction pipe 24 connected to the rotary compression mechanism 23 is provided in the cylindrical portion 21a in a penetrating state, and a discharge pipe 25 connected to a cooling mechanism (refrigeration cycle) not shown penetrates the lid portion 21c. It is arranged in a state.

The motor 22 has a stator 22a fixed to the housing 21 and a lower end of a drive shaft 26 to which the rotor 22b is fixed extended toward the rotary compression mechanism 23 located below. The rotary compression mechanism 23 includes the rotary shaft 2 press-fitted into the lower end of the hollow drive shaft 26.
7, a rotor 28 rotatably fitted in an eccentric position with respect to the rotary shaft 27, and a space with a circular cross section that linearly slidably contacts the outer peripheral surface of the rotor 28 at one location. The cylinder 29 welded to the housing 21 in the arranged state, the upper bearing 30 fixed to the upper end surface of the cylinder 29 to rotatably support the rotating shaft 27 above the rotor 28, and fixed to the lower end surface of the cylinder 29. And a lower bearing 31 that rotatably supports the rotating shaft 27 below the rotor 28.

The rotary shaft 27 is supported with the lower end thereof protruding from the lower bearing 23. An oil pump mechanism 32 for supplying lubricating oil to the hollow interior is provided at the lower end of the rotary shaft 27, and a lubricating oil sump 33 is formed at the bottom of the housing 21.

The rotor 28 is housed in a cylinder chamber 34 formed by closing a circular cross-section space provided in the cylinder 29 with an upper bearing 30 and a lower bearing 31. As shown in FIG. 2, a slot hole 29a is formed on the inner surface of the cylinder 29 forming the cylinder chamber 34, and a blade 35 having one side having a length substantially the same as the thickness of the rotor 28 is formed in the slot hole 29a. A spring body 36 is fitted into the cylinder chamber 34 so that one side of the blade 35 can be retracted and retracted, and behind the blade 35 is a spring body 36 that pushes the blade 35 toward the cylinder chamber 34. The blade 35 is a plate-shaped member having one side having a length substantially equal to the length of the rotor 28 in the thickness direction, and by being biased by the spring body 36, one side thereof is brought into pressure contact with the outer peripheral surface of the rotor 28. ing.

Further, in the cylinder 29 forming the cylinder chamber 34, an intake port 37 located in front of the blade 35 in the rotational direction of the rotor 28 and communicating with the intake pipe 24 is opened, and the upper bearing 30 is provided with the blade 35. From rotor 2
A discharge port 38 that is located at the rear of the rotation direction of 8 and communicates with the discharge pipe 25 is opened. The cylinder chamber 34 is provided on one side of the blade 35 by pressing the tip of the blade 35 against the outer circumferential surface of the rotor 28, and the suction port 37 is provided.
And a compression chamber provided on the other side of the blade 35 and communicating with the discharge port 38.

The discharge port 38 is formed as a circular hole penetrating through the upper bearing 30 and communicates with an upper muffler chamber 40 formed by a cover 39 covering the upper surface of the upper bearing 30. Further, the discharge port 38 opening to the upper muffler chamber 40 side is provided with a discharge valve 41 which is opened when a pressure of a predetermined magnitude or more is received.

Further, the rotary compressor 20 is provided with an accumulator 50 for the purpose of separating the lubricating oil contained in a small amount from the gas flowing through the cooling mechanism. The accumulator 50 has a cylindrical container 51 connected to a pipe through which gas flows. The other end of the suction pipe 24 is opened upward above the inside of the cylindrical container 51. Reference numeral 52 in the figure is a connecting portion of a pipe for introducing gas into the accumulator 50.

Now, as shown in FIG. 3, a laterally elongated elliptical shape is adopted as the cross-sectional shape of the suction port 37 described above. The suction port 37 secures a cross-sectional area similar to that of a conventional circular cross section, and the rotation direction (horizontal direction) of the rotor 28 is larger than the axial direction (vertical direction) of the rotary shaft 27 (H1 <
L1) is a horizontally long elliptical shape. As a result, the cross-sectional shape of the suction port 37 becomes lower than that in the case of a circular cross section in which the height H1 has the same cross sectional area.

Further, the oblong suction port 37 which is horizontally long
A suction fitting 42 is used to connect the suction pipe 24 having a circular cross section. This suction fitting 42
Has a double tube structure composed of an inner tube 42a and an outer tube 42b, and one of the connecting portions is formed in a horizontally elongated elliptical cross section. The elliptical connecting portion is press-fitted and connected to a press-fitting receiving portion 37a having an elliptical cross-section, the diameter of which is increased outside the suction port 34. The connecting portion on the other end side to which the suction pipe 24 is connected has a circular shape that can be inserted into the suction pipe 24 having a circular cross section. That is, the suction fitting 4
Reference numeral 2 is a connecting member having a cross-sectional shape different from that of the elliptical connecting portion and the circular connecting portion at both ends. Inner pipe 42a to prevent pressure loss from increasing
To secure the necessary cross-sectional area.

Next, the procedure for connecting the suction pipe 24 will be briefly described. An outer pipe 21d through which the suction fitting 42 is inserted is welded to the tubular portion 21a of the housing 21 in advance. The cylinder 29 is placed in the housing 21 and is fixed by plug welding in place. At this time, the suction port 37 of the cylinder 29 is positioned so as to coincide with the outer pipe 21d.

After that, the elliptical connection portion of the suction fitting 42 passes through the outer pipe 21d and the suction port 37.
Is press-fitted into the press-fitting receiving portion 37a. Then, the circular connection portion that is the other end of the suction fitting 42 is connected to the accumulator 50 by inserting the inner pipe 42a into the suction pipe 24 that is integral with the accumulator 50. In the rotary compressor 20, the suction fitting 42, and the accumulator 50 thus connected, the outer pipe 21d, the suction fitting 42, and the suction pipe 24 are brazed at the same time.

With such a structure, gas can be sucked from the suction pipe 24 having a circular cross section into the suction port 37 having an elliptical cross section, and further, the cylinder chamber 34 defined by the height H1 of the suction port 37. Cylinder height H (Fig. 9
It is also possible to reduce the leak area S by lowering (see reference).

Hereinafter, a process of operating the rotary compressor 20 having the above-described structure to compress and convey gas will be described. First, when the motor 22 is operated, the rotary shaft 27 connected to the drive shaft 26 rotates and the rotor 28 also starts to rotate. The rotor 28 makes an eccentric rotational motion in the cylinder chamber, and accordingly, gas is sucked from the suction pipe 24 into the suction chamber, and at the same time, gas already sucked into the compression chamber is gradually compressed.

The gas compressed in the compression chamber pushes up the discharge valve 41 from the discharge port 38 and flows into the upper muffler chamber 40, and its pulsating component is removed. The gas flowing into the upper muffler chamber 40 passes through a through hole (not shown) formed in the cover 39, flows below the motor 22 and expands, so that the pulsating component is further removed. The gas flowing into the lower part of the motor 22 passes through the air gap between the stator 22 a and the rotor 22 b and the gas passage formed between the stator 22 a and the housing 21, and flows into the upper part of the motor 22 to expand. By doing so, the pulsating component is further removed. The gas that has flowed above the motor 22 flows into the discharge pipe 25 and is conveyed toward a cooling mechanism (not shown).

On the other hand, the gas flowing through the cooling mechanism flows into the accumulator 50, and becomes fine oil droplets (mist form) to separate the lubricating oil scattered in the gas. Also,
The lubricating oil accumulated in the oil sump 33 is moved upward in the rotary shaft 27 by being urged by the pump action generated by the rotational movement of the oil pump mechanism 32, and the rotor 28 in the cylinder chamber 34 is supplied from a supply path (not shown). Is supplied to the sliding position between the cylinder 29 and the cylinder 29 and is jetted from the upper end of the rotary shaft 27 to cool the rotary compression mechanism 23.

A modification of the suction port 37 having a horizontally long elliptical cross section will be described below with reference to the drawings. Intake port 37A shown in FIG. 4 as a first modification.
Is an elliptical cross-sectional shape instead of the elliptical cross-sectional shape described above. In this case as well, the height H2 of the suction port 37A can be reduced by forming a horizontally long ellipse having the same cross-sectional area as the circular cross section.

As a second modification, the suction port 37B shown in FIG. 5 has a cross-sectional shape of a connecting circle formed by arranging two circles side by side instead of the elliptical cross-sectional shape described above. Also in this case, the height H3 of the suction port 37B can be reduced by using the horizontally long connecting circle having the same cross-sectional area as the circular cross section. Since such a connecting circle can be formed by drilling twice with a drill, the processing is easy. Also,
Such a connection portion on the suction fitting side, which has a connection circular cross section to be press-fitted into the suction port 37B, can be easily formed by pressing a circular cross section tube. Furthermore, if the press working (throttle) on the suction fitting (press-fitting) side is made small and is deformed by further narrowing when press-fitting into the suction port 37B, the adhesion of the connection portion is improved and leakage is prevented. Less likely to occur.

A suction port 37C shown in FIG. 6 as a fourth modified example has a cross-sectional shape in which two circles arranged side by side in a separated state are connected by a rectangle, instead of the above-mentioned elliptical cross-sectional shape. Also in this case, the height H4 of the suction port 37C can be reduced by making the cross-sectional area similar to the circular cross section. Regarding the cross-sectional shape of the suction port 37, in addition to the above-described shapes, a non-rectangular shape or the like in which the axial (vertical) dimension of the rotary shaft 27 is larger than the rotational (lateral) dimension of the rotor 28 is used. It may have a circular shape.

In the above-described embodiment, the compression capacity of the rotary compressor 20 is reduced by reducing the height H of the suction port 37, but this reduction in capacity is due to the outer peripheral surface of the rotor 28 and the cylinder chamber 34. It is possible to compensate by slightly enlarging the outer diameter of the outer peripheral side wall surface. It should be noted that the configuration of the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.

[0036]

According to the above-described rotary compressor of the present invention, since the suction port has a non-circular cross-sectional shape in which the rotor size in the rotational direction is larger than the axial size of the rotating shaft, the intake port is inhaled. It is possible to reduce the cylinder height H by making the flow passage cross-sectional areas of the paths the same. Therefore, if the gap W is kept the same, the leak area S can be reduced, and the leak amount can be reduced by the decrease in the leak area S to improve the efficiency of the compressor.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a rotary compressor according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration example of a rotary compression mechanism.

3 is a sectional view taken along the line AA of FIG. 1 showing a sectional shape of an intake port.

FIG. 4 is a cross-sectional view taken along line AA showing a first modified example of the cross-sectional shape of the suction port shown in FIG.

5 is a sectional view taken along line AA showing a second modification of the sectional shape of the suction port shown in FIG.

6 is a cross-sectional view taken along line AA showing a third modified example of the cross-sectional shape of the suction port shown in FIG. Is.

FIG. 7 is a cross-sectional view of essential parts showing a conventional example of a rotary compression mechanism.

FIG. 8 is a sectional view taken along line B- of FIG.
It is a B sectional view.

9 is an explanatory diagram showing a leakage area S. FIG.

[Explanation of symbols]

20 rotary compressor 21 housing 22 motor 23 Rotary compression mechanism 24 Inhalation tube 25 discharge pipe 27 rotating shaft 28 rotor 29 cylinders 30 upper bearing 31 Lower bearing 34 Cylinder chamber 35 blade 37, 37A-37C Inhalation port 38 Discharge port 41 Discharge valve 42 Inhalation fitting 50 accumulator S Leakage area H cylinder height H1 to H4 suction port height

Continued front page    (72) Inventor Toshiyuki Shikauchi             3-1, Asahi-cho, Nishibiwajima-cho, Nishikasugai-gun, Aichi             Address Mitsubishi Heavy Industries Co., Ltd. (72) Inventor Takahide Ito             1 Takamichi, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi               Mitsubishi Heavy Industries Nagoya Research Center F term (reference) 3H029 AA04 AA13 AB03 BB16 BB42                       BB43 CC24 CC83

Claims (3)

[Claims] 1. A cylindrical cylinder, a rotor rotatably fitted to an eccentric part of a rotary shaft, and an upper bearing fixed to the upper part of the cylinder to rotatably support the rotary shaft above the rotor. An eccentric rotary motion is made in a cylinder chamber consisting of a lower bearing fixed to the lower part of the cylinder and rotatably supporting a rotating shaft below the rotor, and a fluid to be transferred is sucked from a suction port opened toward the cylinder chamber. In the rotary compressor that compresses and compresses and discharges the discharge valve by pushing it open from the discharge port also provided in the cylinder chamber, the suction port has a rotation direction dimension of the rotor larger than an axial dimension of the rotation shaft. A rotary compressor having a non-circular cross-section. 2. The suction port is connected to a suction pipe through a suction fitting having a connecting portion, one of which has the non-circular cross-sectional shape and the other of which has the circular cross-sectional shape. The described rotary compressor. 3. The non-circular cross-sectional shape is an ellipse, an ellipse,
The rotary compressor according to claim 1 or 2, wherein the rotary compressor has a connection circle or a shape in which two circles are connected in a rectangle.