JPH06323275A - Rotary compressor - Google Patents

Abstract

PURPOSE:To provide a rotary compressor capable of reducing a dead volume and retraining the degradation of performance caused by the reexpansion loss increased by the deviation of clearance between a roller and main and auxiliary bearings. CONSTITUTION:A compression mechanism part consists of a cylinder 3 fixed in an enclosed receptacle 10, a roller 4 provided in the cylinder 3 and inserted in an eccentric part 8a of a crankshaft 8, a vane 5 following up the rotation of the roller 4 to reciprocate, a main bearing 6 and auxiliary bearing 7 closing both ends of the cylinder 3 and supporting the crankshaft 8. In a rotary compressor having delivery valves for discharging refrigerant gas compressed in the cylinder 3 and a delivery valve stopper for restraining the opening of the delivery valve respectively attached to both main bearing and auxiliary bearing, the thickness X of a mounting surface of the delivery valve 13 attached to the main bearing 6 is formed thinner than that Y of a mounting surface of the delivery valve 15 attached to the auxiliary bearing 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor mainly used in air conditioners and refrigerators, and more particularly to a rotary compressor suitable for ensuring the performance of the compressor.

[0002]

2. Description of the Related Art A conventional rotary compressor will be described with reference to FIGS. 10 is a vertical cross-sectional view of a compression mechanism portion of a general vertical rotary compressor, FIG. 6 is a main-part vertical cross-sectional view of the compression mechanism portion of FIG.
Is a longitudinal cross-sectional view of a main part showing the operation of the compression mechanism part of FIG.
FIG. 8 is a vertical cross-sectional view of a discharge hole portion equipped with a discharge valve and a discharge valve stopper in a conventional auxiliary bearing, and FIG. 9 is a vertical cross-sectional view of a discharge valve portion equipped with a discharge valve and a discharge valve stopper in a conventional main bearing. It is a figure.

As shown in FIG. 10, a vertical rotary compressor generally houses a motor unit 1 in the upper portion of a closed container 10 and a compression mechanism unit 2 in the lower portion, and a lubricating oil 1 at the bottom of the closed container 10.
1 is stored. The electric motor unit 1 is composed of a rotor 1a and a stator 1b, and the compression mechanism unit 2 is fitted into a cylinder 3 fixed to the inner wall of the closed container 10 and an eccentric portion 8a of a crankshaft 8 provided in the cylinder. A roller 4 relating to a rolling piston, a vane 5 that reciprocates following the eccentric rotation of the roller 4, a main bearing 6 and a sub bearing 7 that seal both ends of the cylinder 3 and support a crankshaft 8,
It is composed of a discharge cup 9 fitted to the auxiliary bearing 7.

The compressor having the above-mentioned structure is provided with the rotor 1
a rotates, and the crankshaft 8 fitted in the rotor 1a
The roller 4 fitted in the eccentric portion 8a rotates eccentrically along the inner wall of the cylinder 3 and compresses the refrigerant gas sucked into the cylinder chamber 3b from the refrigerant suction hole (not shown). When the pressure in the cylinder chamber 3b becomes higher than the pressure in the closed container 10, the discharge valve 15 on the sub bearing 7 side and the discharge valve 13 on the main bearing 6 side open to the sub bearing 7 side and the main bearing 6 side, respectively, The refrigerant gas in 3b is discharged outside the cylinder chamber 3b.

Here, since the discharge gas in the discharge notch of the cylinder 3 and the discharge gas of the main and auxiliary bearings remains without being discharged to the outside of the cylinder 3, the gas reaching this discharge pressure returns to the inside of the cylinder chamber 3b. As a result, the suction pressure in the cylinder chamber 3b is prevented. This action is called re-expansion loss and is a factor that reduces the volumetric efficiency of the compressor.
The volume not discharged from the discharge notch and the discharge port is called a dead volume.

In addition, in the conventional general rotary compressor,
The roller 4 fitted in the eccentric portion 8a of the crankshaft 8
When the compressor is not in operation, is biased closer to the sub bearing 7 side due to its own weight as shown in FIG. 6, and after the operation of the compressor is started, as shown in FIG. Due to the pressure difference between the inner diameter portion 2 and the inner pressure of the cylinder chamber 3b, it is pressed toward the side with a smaller clearance.
Further, in the conventional rotary compressor, the wall thickness A of the mounting surface of the discharge valve 15 and the discharge valve stopper 16 mounted on the auxiliary bearing 7 shown in FIG. 8 and the discharge valve mounted on the main bearing 6 shown in FIG. 1
3. The relation with the wall thickness B of the mounting surface of the discharge valve stop 14 is A = B
Has become.

[0007]

In the above prior art, in order to reduce the re-expansion loss and improve the volumetric efficiency, it was necessary to reduce the discharge port diameter and the discharge port cross-sectional area. However, if the diameter of the discharge port is reduced, the flow velocity of the discharge gas is increased, so that the discharge loss is increased. If the cross-sectional area of the discharge port is reduced, the wall thickness B of the mounting surface of the discharge valve 13 mounted on the main bearing 6 is
And the thickness A of the mounting surface of the discharge valve 15 mounted on the auxiliary bearing 7 becomes thin, and when the cylinder chamber 3b reaches the suction pressure that is the lowest pressure, deformation due to the pressure difference between the inside of the compression container 10 and Therefore, there is a problem that metal powder is generated due to wear caused by contact with the roller 4, and in the worst case, the compressor may be locked.

Further, the roller 4 fitted into the eccentric portion 8a of the crankshaft 8 is the weight of the roller 4 or the roller 4 itself.
When pressed against the sub bearing 7 due to the pressure difference on the inner diameter side and the pressure inside the cylinder chamber 3b, the clearance between the main bearing 6 and the roller 4 on the side where the roller is not pressed increases, thereby increasing leakage. There was a problem that the performance deteriorated.

The present invention has been made to solve the above-mentioned problems of the prior art. It is possible to reduce the dead volume while ensuring the reliability, and the clearance between the roller and the main and auxiliary bearings. It is an object of the present invention to provide a rotary compressor in which the deterioration of the performance due to the increase of the re-expansion loss due to the deviation of the above is improved.

[0010]

In order to achieve the above object, a rotary compressor according to the present invention has a structure in which an electric motor section and a compression mechanism section are connected by a crankshaft and housed in a closed container. Therefore, the compression mechanism section reciprocates following a cylinder fixed in a closed container, a rolling piston fitted in an eccentric portion of a crankshaft provided in the cylinder, and following the rotation of the rolling piston. A vane and a main bearing and a sub-bearing that seal the both ends of the cylinder and support the crankshaft. The discharge valve for discharging the refrigerant gas compressed in the cylinder and the opening degree of the discharge valve are provided. In a rotary compressor in which a suppressing discharge valve stop is mounted on both the main bearing and the sub bearing, the wall thickness of the mounting surface of the discharge valve mounted on the main bearing is mounted on the sub bearing. Than the thickness of the mounting surface of the off valve is obtained by thinly formed.

[0011]

The function of the above technical means is as follows. In the compression chamber formed by the cylinder, when the roller fitted in the eccentric part of the crankshaft is pressed against the sub bearing due to the roller's own weight or the pressure difference between the pressure inside the roller and the pressure inside the compression chamber, the roller is pressed. The clearance between the main bearing and the roller on the unsupported side increases. However, if the wall thickness of the mounting surface of the discharge valve mounted on the main bearing is made thin, it deforms due to the pressure difference between the pressure inside the closed container and the suction mechanism inside the compression mechanism, and the clearance between the main bearing and the roller is reduced. Can be reduced. Set the wall thickness of the mounting surface of the discharge valve mounted on this main bearing to a range where there is no abnormal wear on the mounting surface of the discharge valve due to contact with the rollers and there is no problem in reliability, reducing dead volume,
Moreover, since the leakage of the discharge pressure into the cylinder can be reduced, the re-expansion loss can be reduced and the performance can be improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a vertical cross-sectional view of a compression mechanism portion of a rotary compressor according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a discharge valve portion and a discharge hole portion equipped with a discharge valve stopper in the auxiliary bearing of FIG. FIG. 3 is a vertical cross-sectional view of a discharge hole and a discharge hole portion equipped with a discharge valve stopper in the main bearing of FIG. 1, and FIG. 4 is a diagram showing the thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing and the main bearing. The change in the wall thickness ratio of the mounted discharge valve mounting surface, re-expansion loss,
FIG. 5 is a diagram showing the relationship with the EER, showing a change in the ratio of the wall thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing to the wall thickness of the mounting surface of the discharge valve mounted on the main bearing, and The clearance between the roller when the deflection of the mounting surface of the discharge valve mounted on the bearing is maximized, the wear of the mounting surface of the discharge valve mounted on the main bearing and the mounting surface of the discharge valve mounted on the auxiliary bearing It is a diagram which shows the relationship with quantity.

The rotary compressor shown in FIG.
An electric motor unit 1 is housed in the upper part of 0, a compression mechanism unit 2 is housed in the lower part, and lubricating oil 11 is stored in the bottom part of the closed container 10. The electric motor unit 1 is composed of a rotor 1a and a stator 1b, and the compression mechanism unit 2 is fitted into a cylinder 3 fixed to the inner wall of the closed container 10 and an eccentric portion 8a of a crankshaft 8 provided in the cylinder. A roller 4 relating to a rolling piston, a vane 5 which reciprocates following the eccentric rotation of the roller 4, a main bearing 6 and a sub bearing 7 which seal both ends of the cylinder 4 and support a crank shaft 8, and a sub bearing 7 thereof.
It is composed of a discharge cup 9 fitted to.

Reference numeral 7b shown in FIG. 2 is a discharge port provided in the auxiliary bearing 7, 15 is a discharge valve, 16 is a discharge valve stop, and Y is the thickness of the mounting surface of the auxiliary bearing side discharge valve. In addition, 6 shown in FIG.
b is a discharge port provided in the main bearing 6, 13 is a discharge valve, 1
4 is the discharge valve stop, and X is the thickness of the mounting surface of the main bearing side discharge valve.

The compressor having the above-described structure is provided with the rotor 1
a rotates, and the crankshaft 8 fitted in the rotor 1a
The roller 4 fitted in the eccentric portion 8a rotates eccentrically along the inner wall of the cylinder 3 and compresses the refrigerant gas sucked into the cylinder chamber 3b from the refrigerant suction hole (not shown). When the pressure in the cylinder chamber 3b becomes higher than the pressure in the closed container 10,
The discharge valve 15 on the side of the auxiliary bearing 7 shown in FIG. 2 and the discharge valve 13 on the side of the main bearing 6 shown in FIG.
The refrigerant gas in b is discharged from the discharge hole 7b and the discharge hole 6b. Then, the eccentric portion 8a of the crankshaft 8 has the vane 5
When moving toward the refrigerant suction hole side, the cylinder chamber 3b
Since the inside becomes a suction pressure and becomes lower than the pressure inside the closed container 10, the inside of the cylinder chamber 3b repeats high pressure and low pressure.

Further, when the rotor 1a is not rotated, the roller 4 is biased to the sub bearing side by its own weight as shown in FIG. Then, the rotor 1a rotates and the cylinder chamber 3
When the pressure in b repeats high pressure and low pressure, the pressure of the inner diameter portion 2 in contact with the eccentric portion 8 a of the crankshaft 8 of the roller 4 becomes the same pressure as in the closed container 10. When the pressure in the cylinder chamber 3b becomes lower than the pressure in the closed container 10, the roller 4
The pressure in the sealed container 10 is applied to the gap between the main bearing 6 and the sub bearing 7. The roller 4 is biased to the side of the sub bearing when the rotor 1a is not rotated, and a large pressure is applied to the gap between the roller 4 and the main bearing 6 in the hermetically sealed container 10. It can be pressed.

Here, as shown in FIGS. 2 and 3, the wall thickness X of the mounting surface of the discharge valve 13 mounted on the main bearing 6 and the wall thickness Y of the mounting surface of the discharge valve 15 mounted on the auxiliary bearing 7. And X <Y, the amount of deformation of the wall thickness X on the main bearing side and the wall thickness Y on the auxiliary bearing side to the cylinder chamber side due to the pressure difference between the sealed container 10 and the cylinder chamber 3b. Has a mounting surface on the main bearing side larger than that on the auxiliary bearing side.

FIG. 4 shows the discharge valve 13 mounted on the auxiliary bearing 7.
The thickness Y of the mounting surface is constant, and the ratio of the wall thickness X of the mounting surface of the discharge valve 15 mounted on the main bearing 6 to the wall thickness Y (X /
It is a diagram which shows re-expansion loss and EER (compressor efficiency) when Y) is changed. Further, in FIG. 5, when the compressor is in operation, the closed container 10 has a discharge pressure and the cylinder chamber 3b has a suction pressure, and the amount of deflection of the wall thickness X and Y into the cylinder chamber 3b is maximized. 6 is a diagram showing the relationship between the clearance with the roller 4 and the amount of wear of each of the discharge valve mounting surface mounted on the main bearing and the discharge valve mounting surface mounted on the auxiliary bearing.

As is clear from FIG. 4, the EER is hardly improved when X / Y = 1 to 0.9, and X / Y =
When it is less than 0.9, it starts to improve. Further, as is clear from FIG. 5, the clearance X / Y = 0.
When it is smaller than 9, it starts to shrink. Where the lord,
Looking at the amount of wear of the mounting surface of each discharge valve mounted on the auxiliary bearing, it rapidly increases when X / Y = 0.8 is less than 0.8. From this, X / Y may be set to 0.8 to 0.9 in order to reduce the re-expansion loss and improve the EER within the range where the reliability does not decrease.

[0020]

As described in detail above, according to the present invention, the wall thickness of the mounting surface of the discharge valve mounted on the main bearing is made smaller than the wall thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing. It is possible to provide a rotary compressor in which dead volume can be reduced by making it thinner, and performance deterioration due to increase in re-expansion loss due to deviation of the clearance between the roller and the main and auxiliary bearings is improved. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a compression mechanism portion of a rotary compressor according to an embodiment of the present invention.

2 is a vertical cross-sectional view of a discharge hole portion equipped with a discharge valve and a discharge valve stopper in the auxiliary bearing of FIG.

FIG. 3 is a vertical cross-sectional view of a discharge hole portion equipped with a discharge valve and a discharge valve stopper in the main bearing of FIG.

FIG. 4 shows a change in the ratio of the wall thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing to the wall thickness of the mounting surface of the discharge valve mounted on the main bearing,
It is a diagram which shows the relationship with re-expansion loss and EER.

FIG. 5 shows a change in the ratio of the wall thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing to the wall thickness of the mounting surface of the discharge valve mounted on the main bearing,
The clearance between the mounting surface of the discharge valve mounted on the main and auxiliary bearings and the roller when the amount of deflection is maximized, the mounting surface of the discharge valve mounted on the main bearing and the mounting surface of the discharge valve mounted on the sub bearing FIG. 6 is a diagram showing the relationship with the wear amount of

FIG. 6 is a longitudinal cross-sectional view of essential parts showing the compression mechanism part of FIG. 10 when not operating.

FIG. 7 is a longitudinal cross-sectional view of essential parts showing the compression mechanism section in FIG. 10 during operation.

FIG. 8 is a vertical cross-sectional view of a discharge hole portion equipped with a discharge valve and a discharge valve stopper in a conventional auxiliary bearing.

FIG. 9 is a vertical cross-sectional view of a discharge hole portion equipped with a discharge valve and a discharge valve stopper in a conventional main bearing.

FIG. 10 is a vertical sectional view of a compression mechanism portion of a general vertical rotary compressor.

[Explanation of symbols]

 3 cylinder 4 roller 5 vane 6 main bearing 7 auxiliary bearing 8 crankshaft 8a eccentric part 13,15 discharge valve 14,16 discharge valve stop,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukichi Nakata 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Hitachi, Ltd. Living Equipment Division Cooling & Heating Division

Claims (2)

[Claims] 1. An electric motor unit and a compression mechanism unit are connected by a crankshaft and housed in a closed container, wherein the compression mechanism unit includes a cylinder fixed in the closed container, and a cylinder fixed in the cylinder. A rolling piston provided in an eccentric part of the crankshaft, a vane that reciprocates following the rotation of the rolling piston, a main bearing and a sub-bearing that seal both ends of the cylinder and support the crankshaft. And a rotary compressor in which a discharge valve for discharging the refrigerant gas compressed in the cylinder and a discharge valve stopper for suppressing the opening of the discharge valve are mounted on both the main bearing and the sub bearing. 2. The rotary compressor according to, wherein the thickness of the mounting surface of the discharge valve mounted on the main bearing is thinner than the thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing. 2. The thickness of the mounting surface of the discharge valve mounted on the main bearing is 80 to 90% of the thickness of the mounting surface of the discharge valve mounted on the auxiliary bearing. The rotary compressor according to Item 1.