JPS621118B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary compressor housed in a closed container, and particularly to a rotary compressor suitable for small-sized, low-power, low-temperature refrigerators that require a high compression ratio. A rotary compressor has one set of compression elements consisting of a cylinder, rollers, blades, discharge port, and suction port, and the compression part can be designed in a circular shape by combining with the cylindrical shape of the drive motor. The dimension perpendicular to the drive rotation axis does not increase significantly, making it lightweight and compact.The reciprocating mass of the rotating part of the compression section is small, making it easy to balance, and the continuous compression action reduces the pulsation of the discharged gas. Since there is less vibration, there is less vibration. Furthermore, unlike reciprocating compressors, rotary compressors have many advantages, such as superior efficiency and low power consumption, since refrigerant gas can be drawn into a cylinder within a closed container without overheating. For this reason, it is often used as a compressor with a relatively low compression ratio as a small air conditioning refrigerator. However, when conventional rotary compressors are used at high compression ratios, especially for low-temperature applications such as refrigerators, compressed gas leaks from the mating parts due to an increase in the pressure difference between the inside and outside of the compression element, resulting in a reduction in volumetric efficiency. and the shape must be increased accordingly. To compensate for this drawback, there are known speed-controlled compressors that can increase the speed of the compressor above the rated speed, but in this case, compression elements such as blades, discharge ports, and suction ports are located on one side of the cylinder. As the rotation speed increases, the vibration becomes noticeable and becomes larger. Further, since the blade pressing spring continues to flex by an amount equivalent to the lift of the vane each time, there is a drawback that the reliability of the strength of the blade pressing spring decreases. Furthermore, in a conventional rotary compressor with one set of compression elements, the indicated efficiency decreases as the compression ratio increases, and therefore the driving power must be increased. Furthermore, since the sealed container of a rotary compressor is a high-pressure container filled with discharged gas, the temperature of the windings of the drive motor also rises as the temperature of the discharged gas rises, causing the temperature limit to be exceeded. ing.

An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a rotary compressor suitable for low-temperature refrigerators and the like.

In order to achieve the above object, the present invention provides two blades in a cylinder of a compressor on a straight line passing through the center of the cylinder, facing each other and in contact with a roller. By providing two sets of elements to reduce vibration during high-speed rotation, lowering the compression ratio on each of the low-pressure side and high-pressure side compared to single-stage compression, and lowering the temperature of the suction gas of the refrigerant on the high-pressure side. , the adiabatic compression work is reduced, and the rise in the temperature of the discharged gas is suppressed to prevent the coil temperature from rising.

The present invention will be explained below with reference to an embodiment shown in FIG. In Figure 1, the suction/discharge device on the low pressure side (first stage) consists of sections 10 to 12, and the suction/discharge device on the high pressure side (second stage) consists of sections 13 to 12.
It is a part consisting of 5. That is, the low-pressure side suction/discharge device consists of a low-pressure side suction port 10, a low-pressure side blade 11, and a low-pressure side discharge port 12, and the high-pressure side suction/discharge device consists of a high-pressure side suction port 15,
High pressure side blade 14 and high pressure side discharge port 13
The cylinder space formed by the cylinder 3 and the roller 4 rotated by the drive shaft 5 having an eccentric portion is divided into two parts, a low-pressure side cylinder space 7 and a high-pressure side cylinder space 8, by two blades 11 and 14. are doing.

Here, in particular, the low pressure side blade 11 and the high pressure side blade 14 are arranged so as to sandwich the roller 4 on a straight line passing through the center of the cylinder, and are provided facing each other. A U-shaped rod-shaped blade pressing spring 6 is fixed to the back of the blade through the open space of the high-pressure chamber space 2.

Further, 9 is a low-pressure pipe connected to a refrigeration cycle (not shown) connected to the low-pressure side suction port 10, 17 is a low-pressure discharge pipe connected to the low-pressure side discharge port 12, and 16 is connected to the high-pressure side suction port 15. High pressure piping 16 and low pressure discharge piping 1
A cooler 18 for cooling the gas discharged from the low-pressure side is provided between the gas pump and the gas pump 7.

Note that 1 is the sealed case, and 2 is the high pressure side discharge port 1.
3 is a high-pressure chamber space for storing the gas emitted from the chamber, and 6 is a blade pressing spring.

Next, the operation of the compressor configured as described above will be explained. Refrigeration cycle outside sealed case 1 (not shown)
The low-temperature, low-pressure refrigerant gas that has returned to the low-pressure pipe 9 from the cylinder 3 is sucked into the low-pressure side cylinder space 7 from the low-pressure side suction port 10 of the cylinder 3, and then flows into the cylinder 3 of the roller 4.
Due to the closing of the blade 11, accompanied by an eccentric rotational movement in contact with the inner wall of the cylinder 3 and a lifting movement (movement of the cylinder 3 outward) of the low pressure side blade 11,
It is compressed to an intermediate pressure lower than a predetermined high compression level, and the low pressure discharge pipe 1 is discharged from the low pressure side discharge port 12.
7 and is discharged. The discharged gas is once led to the piping outside the sealed case 1, and the refrigerant gas, whose temperature has risen to a certain extent, is cooled by the cooler 18, and then returned to the high pressure side piping 16 inside the sealed case 1, where it becomes low temperature and medium pressure. The refrigerant gas is transferred from the high pressure side suction port 15 to the high pressure side cylinder space 8 and into the low pressure side cylinder space 7.
In synchronization with the compression action at
4's downward movement (inward movement of the cylinder 3) and the closing action, the roller 4 is sucked in again.
A two-stage compression action is performed in which compression work is accomplished by compressing to a predetermined high pressure by the rotational movement of the blade 14 and the closing of the high-pressure side blade 14.

As described above, the present invention has the following effects.

(1) In a conventional one-stage rotary compressor, as the rotation speed increases, the plate, discharge port,
Since the compression elements consisting of suction ports are unevenly distributed on one side, vibrations become large, but the two sets of compressors of the present invention have these compression elements 180
Since they are arranged symmetrically and in a well-balanced manner, vibrations can be reduced even during high-speed rotation.

(2) In a conventional compressor, the blade pressure spring is a rod-shaped spring that locks one end of the spring to the cylinder.
The structure is such that a coil spring is installed on the back of the blade, but these blade pressure springs are subject to strain and load equal to the stroke of the blade's linear reciprocating motion each time, and as the blade rotates at high speeds, Therefore, the reliability is reduced, whereas the blade pressing spring of the present invention has
It locks onto two blades that sandwich a roller and moves in the same direction as the blades move, and the gap between the two blades maintains a length close to the roller diameter, so it can rotate at high speeds. Since the initial load at the time of locking is maintained even if the parts are bent, the reliability of this part can be improved.

(3) In conventional one-stage rotary compressors, the discharge gas temperature becomes too high to be applied to low-temperature refrigeration cycles such as refrigerator-freezers, and this high-temperature, high-pressure gas is discharged into a sealed case. Therefore, the motor coil winding temperature is directly affected by the high temperature discharged gas and exceeds the heat resistance limit. However, according to the compressor of the present invention, the suction temperature on the high pressure side can be lowered by cooling at an intermediate pressure, and the discharge gas temperature on the high pressure side can therefore be kept low, so the coil winding temperature can be kept within the heat resistance limit. can be suppressed to

(4) In the conventional rotary compressor, a refrigeration cycle of E-LO-HA-HO-HE-TOI is formed on the Mollier diagram shown in Figure 2, and among these, E-ROHA is Performs adiabatic compression work along the line. The line formed by this curve tends to have a steeper slope as it approaches the saturated gas line 20. Therefore, the enthalpy decreases by that amount, and the work of adiabatic compression can be measured.

The present invention performs two-stage compression.
By performing Niho's adiabatic compression work, the above characteristics can be utilized and the compressor efficiency can be improved.

(5) Since the compression ratio is lowered by compressing in two stages, the amount of compressed gas leakage is reduced than before, and even when used for low temperature applications, the volumetric efficiency is not reduced.
Compression efficiency can be maintained or improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the two-stage compression mechanism of the present invention;
FIG. 2 is a Mollier diagram showing conventional adiabatic compression and adiabatic compression of the present invention. 10...Low pressure side suction port, 11...Low pressure side blade, 12...Low pressure side discharge port, 13...High pressure side discharge port, 14...High pressure side blade, 15
...High pressure side suction port, 18...Cooler.

Claims (1)

[Claims] 1 In a rotary compressor housed in a closed container, two sets of compression elements consisting of a blade, a discharge port, and a suction port are arranged in one cylinder of the rotary compressor, and the two blades pass through the center of the cylinder. A rotary compressor, characterized in that the two blades are arranged in contact with rollers facing each other in a straight line, and each of the two blades is locked at both ends of one rod-shaped blade pressing spring.