JPS629750B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a forced oil-feeding semi-hermetic compressor, and particularly to improvements in its pressure equalization mechanism.

(Prior technology) A conventional refrigerator (hereinafter referred to as a parallel refrigerator, hereinafter referred to as a parallel refrigerator, in which the suction and discharge pipes are connected to each other and multiple semi-hermetic compressors are used for one condenser) When operating two compressors, the oil level in each crank chamber is not uniform due to variations in pressure loss on the suction side. Pressure equalization piping for equalizing the pressure in each crank chamber to the refrigerant gas atmosphere above the level of the lubricating oil stored in the crank chamber, and lubrication pipes below the level of the lubricating oil. A pressure equalizing pipe is provided in the oil phase. Furthermore, this type of refrigerator has a mechanism in which operation is switched from operating two compressors to operating one compressor in response to fluctuations in the load on the cooler side within the refrigeration cycle.

The structure of a conventional parallel refrigerator will be explained below with reference to figures. In Fig. 1, 1 and 2 are semi-hermetic compressors, 31 and 32 are a motor chamber 6 in which a motor (not shown) is housed, 8 and crank chambers 9 and 10 in which the compression mechanism section is housed, and the motor chamber 6,
8, and the refrigerant gas atmosphere portions 6a, 8a and 9a, 10a of the crank chambers 9, 10 and the lubricating oil phase portion 6.
It shows an inner wall provided with pressure equalizing holes 11, 12 and oil return holes 15, 16 that communicate with each other.b, 8b and 9a, 10b.

Reference numeral 3 denotes a suction pipe that connects a cooler (not shown) that performs a cooling action and the compressors 1 and 2, and the arrow in the figure indicates the flow direction of the refrigerant. 4 is a discharge pipe for sending the refrigerant gas compressed by the compressors 1 and 2 to a condenser (not shown), and the arrow in the figure indicates the flow direction of the refrigerant. The refrigerant sent to the condenser passes through an expansion valve (not shown) through a connecting pipe and reaches the cooler. The refrigerant that performs the cooling action in this cooler is
It passes through the suction pipe 3 and is compressed again by the compressors 1 and 2.

The above cycle is called a refrigeration cycle.
In the parallel refrigerator in this refrigeration cycle, if we consider the case where one compressor is operated (only compressor 1 on the left side in the figure is operated), the operating valve installed at the inlet of the operating side compressor 1 5 after passing through the motor chamber 6;
A pressure difference is created between the stopped compressor 2 and the motor chamber 8 after passing through the operation valve 7 provided at the suction port, and the motor chamber 8 side of the stopped compressor 2 becomes higher. The refrigerant gas moves through the pressure equalization pipe 13 that communicates the refrigerant gas atmosphere parts of the crank chambers 9 and 10 of each compressor 1 and 2, and the pressure in each part is adjusted to the motor chamber 8 of the stop side compressor 2.
is the highest, followed by the crank chamber 10 of the stopped compressor 2, then the crank chamber 9 of the operating compressor 1, and the motor chamber 6 of the operating compressor 1 is the lowest.

On the other hand, when both compressors 1 and 2 are in operation, a small amount of the lubricating oil 14 stored at the bottom of the crank chambers 9 and 10 normally circulates together with the refrigerant in the refrigeration cycle, is returned to the motor chambers 6 and 8, and is sent to the motor chambers 6 and 8. Room 6, 8
When lubricating oil has accumulated to some extent, the crank, which is slightly higher than the motor chambers 6 and 8, is caused by high pressure blow-by from between the cylinder and piston (both not shown) due to the water head difference due to the height of the oil. Hydraulic feed holes 15 and 16 to overcome the pressure in chambers 9 and 10
It is returned to the crank chambers 9 and 10 through the
When one compressor 1 is in operation, the pressure difference in the motor chamber 8 of the stopped compressor 2 affects the crank chamber 9 of the operating compressor 1 via the pressure equalizing hole 12 and the pressure equalizing pipe 13, As a result, the pressure in the crank chamber 9 of the driving compressor 1 is increased, and the pressure difference with the motor chamber 6 further increases, making it difficult for the lubricating oil accumulated in the motor chamber 6 to be returned to the crank chamber 9 side. The amount of lubricating oil accumulated in the motor chamber 6 increases. Therefore,
A large amount of lubricating oil is sucked into the compression part (cylinder) together with refrigerant gas by the rotor part (not shown) of the motor rotating in the motor chamber 6, causing valve cracking and leakage inside the refrigeration cycle due to oil (liquid) compression. Decrease in refrigeration capacity due to increased circulating oil, and further damage to the crank chamber 9
There have been cases where metal parts have seize due to lack of oil on the side.

(Purpose of the Invention) This invention was made to eliminate the above-mentioned drawbacks, and integrates the pressure equalizing piping outlet for equalizing the pressure in the crank chambers of both compressors and the hydraulic pressure regulating valve. By installing a hydraulic pressure adjustment valve with a pressure equalization outlet that opens and closes the pressure equalization port, it is possible to prevent a decrease in refrigeration capacity due to an increase in the amount of oil coming out, valve cracking due to oil compression, and metal seizure due to lack of oil in the crank chamber. The purpose of this invention is to provide a refrigerant compressor that is possible.

(Example) An embodiment of this invention will be shown below.

Fig. 2 is an external view of the compressor showing the installation state of the hydraulic pressure regulating valve device 18 with pressure equalization outlet, Fig. 3 is a plan view of the compressor in Fig. 2, and Figs. 4 and 5 are the A sectional view taken along line A-A shows the compressor when it is in operation and when it is stopped. In the figure, reference numeral 17 denotes a crank chamber wall, and a hydraulic pressure regulating valve device 18 with a pressure equalization outlet is attached to the crank chamber wall 17 of each compressor 1, 2 with a bolt 34 via a packing 19. Normally, in a forced lubrication type semi-hermetic compressor, lubricating oil stored at the bottom of the crank chamber is pumped through an oil hole provided in the crankshaft by an oil pump 35 directly connected to the crankshaft. It is pumped to the department. In order to keep this oil pressure constant, an oil return piping 20 is provided to bypass a part of the oil pumped from the oil pump and return it to the crank chamber. A hydraulic control valve is installed at the outlet to the chamber. 13a is a pressure equalizing pipe for equalizing the pressure in the crank chambers 9, 10 of each compressor 1, 2, and these pipes are "connected to the oil pressure regulating valve body 21 by brazing or the like. This valve body" 21 is provided with a smoothly finished cylinder 22, a pressure equalization port 23, and a hydraulic pressure return port 24, and a piston 25 and a coil spring 26 are installed inside the cylinder 22 via a packing 27 and a plug 28. ing. The piston 25 has large diameter portions 29 on both sides with a smoothly finished outer circumferential portion, and a small diameter portion 30 provided in the center thereof. Also, this piston 25
can move within the cylinder 22, and one end face is always pushed toward the oil return pipe 20 by a coil spring 26. Figure 4 shows the state of the piston position when the compressor is operating. As mentioned above, when the compressor is operating, oil is being pumped under pressure by the oil pump, and the bypassed oil is indicated by the arrow in the figure. As shown, the oil is returned to the crank chamber from the oil return port 24 through the oil return pipe 20, and the pressure between the crank chambers 9 and 10 is equalized. That is,
The end face of the piston 25 is pressed by the oil pressure of the oil return pipe 20 and moves in the opposite direction to the oil return pipe 20 against the coil spring 26, so that the large diameter portion 29 of the piston 25 opens the oil return port 24. The oil return pipe 20 communicates with the crank chamber, and the small diameter portion 30 of the piston 25 coincides with the pressure equalization port 23 provided in the valve body 21, so that the pressure equalization port 23 is opened.
The pressure equalization pipe 13a and the inside of the crank chamber communicate with each other via a pressure equalization port 23 and a cylinder 22. Therefore, when both compressors 1 and 2 are in operation, the pressure equalization outlet oil pressure regulating valve device 18 of the compressors 1 and 2 is always in this state, so oil is returned to both crank chambers 9 and 10, and oil is returned to both crank chambers 9 and 10. The pressure is equalized between 9 and 10. On the other hand, when the compressor is stopped, oil is not pumped by the oil pump as shown in FIG. Move to the piping 20 side.

In this state, the large diameter portion 2 of the piston 25
9 coincides with the pressure equalization port 23 provided in the valve body 21, and since the pressure equalization port 23 is closed, even when one compressor is operated in a parallel refrigerator (in Fig. 1, the compressor 1 is in operation) The pressure difference in the motor chamber 8 of the stopped compressor 2 does not affect the crank chamber 9 of the operating compressor 1 (note that the oil equalization pipe 33 remains open at this time, so (During operation, the oil in the compressor crank chamber 10 moves slightly into the compressor flank chamber 9 during operation, and the oil level in the compressor crank chamber 9 increases slightly during operation, but the internal pressure does not increase.) Since the pressure inside the crank chamber 9 is not increased, the lubricating oil returned to the motor chamber 6 accumulates in the motor chamber 6, and the difference in water head due to the height of the oil overcomes the pressure inside the crank chamber 9. Oil return hole 15
It is returned to the crank chamber 9.

(Effects of the Invention) As described above, according to this invention, communication between the pressure equalizing pipes is opened and closed by the operation of the hydraulic pressure regulating valve. ) It has the effect of preventing valve cracking due to compression and metal seizure due to lack of oil in the crank chamber.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a parallel type refrigerator, Fig. 2 is an external view of a refrigerant compressor showing the installation state of a hydraulic pressure regulating valve device with a pressure equalization outlet to which the present invention is applied, and Fig. 3 is a schematic diagram of a parallel type refrigerator. The plan view of the refrigerant compressor in the figure, and FIGS. 4 and 5 are sectional views taken along the line AA in FIG. 3, showing the refrigerant compressor when it is in operation and when it is stopped, respectively. In the figure, 1 and 2 are semi-hermetic compressors, 6 and 8 are motor chambers, 9 and 10 are crank chambers, 13a is pressure equalization piping, 18 is a hydraulic pressure regulating valve device with a pressure equalization outlet, 2
0 is the oil return pipe, 21 is the oil pressure regulating valve body, 22 is the cylinder, 23 is the pressure equalization port, 24 is the oil return port, 25
is a piston, 26 is a coil spring, 29 is a large diameter portion of the piston, and 30 is a small diameter portion of the piston. Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A pressure equalizing hole and an oil space are provided which partition a motor chamber in which a motor is housed and a crank chamber in which a compression mechanism is housed, and communicate the refrigerant gas atmosphere part and the lubricating oil phase part of the motor chamber and the crank chamber, respectively. Suction/discharge of a plurality of forced-lubricated semi-hermetic compressors, each having an inner wall provided with a return hole and having a hydraulic pressure adjustment valve that communicates with the crank chamber and adjusts the hydraulic pressure of lubricating oil supplied to the compression mechanism. The pipes communicate with each other, and the refrigerant gas atmosphere part of each crank chamber and the lubricating oil phase part are communicated with each other by a pressure equalization pipe and an oil equalization pipe, respectively, and the pressure is equalized by the operation of the hydraulic pressure regulating valve. A refrigerant compressor characterized by opening and closing piping communication.