JPS6332945Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a parallel compressor, in particular, when compressors connected in parallel are operated in parallel, or when any compressor is operated, the oil in the compressor is This invention relates to a parallel compression device that maintains a proper surface.

In a conventional system using two compressors, a pressure equalization/oil equalization pipe is installed between both compressors, and this pipe is only blocked during service, and the operation can be performed regardless of parallel operation or single-lung operation. The inside was connected with only an open operation valve installed. As a result, in one-sided operation for capacity control, the internal pressure of the compressor on the stop side becomes relatively higher than the internal pressure of the compressor on the operating side by a pressure equivalent to the resistance of the branch pipe of the suction pipe, and the suction pipe of the compressor in operation The oil that has returned to the suction chamber side cannot be returned to the compression element chamber side, making it impossible to maintain an appropriate oil level in the compressor on the operating side, resulting in poor supply of lubricating oil to the sliding parts of the compressor. There were drawbacks such as seizure and abnormal wear caused by this, reduction in refrigeration capacity due to excessive oil flow, and damage and destruction of the valve part due to oil compression. In addition, in order to improve oil consumption during one-sided operation, there is a method to install an oil separator on the discharge side and collect some of the discharged oil, but in this case, the oil separated by the oil separator is at a high temperature. This causes an increase in the oil temperature within the compressor, which is unfavorable in terms of lubrication of the sliding parts of the compressor.

This invention was made to improve the above-mentioned drawbacks, and is characterized by opening the on-off valve corresponding to a predetermined compressor using the fluid pressure generated by the compressor during a predetermined compressor operation.

In the following, the invention will be explained with reference to the illustrated embodiments. As shown in FIG. 1, the semi-hermetic compressors 1 and 2 are equipped with crankcases 101 and 201 for constructing the compressors, and the interior of the crankcases is partitioned into a motor chamber 10 by partition walls 102 and 202.
3,203 and compression element chambers 104,204. The motor chambers 103 and 203 house motors 105 and 205, and the compression element chambers 104 and 204 house compression elements 106 and 206, respectively.
This compression element 106, 206 is connected to the motor 105, 2
Crankshafts 107, 20 driven by 05
7, connecting rod 108, 208, piston 109, 2
09, cylinders 110, 210, and a valve device (not shown). Motor chamber 103, 20
A pressure equalizing check valve 113, 213 is placed between the compression element chamber 104, 204 and the compression element chamber 10.
4,204 side to the motor chamber 103,203 side. An oil equalizing check valve 114 between the oil reservoirs 115, 215 of the motor chambers 103, 203 and the oil reservoirs 116, 216 of the compression element chambers 104, 204,
214 to allow flow from the motor chamber 103, 203 side to the compression element chamber 104, 204 side. Compressors 1 and 2 configured in this way
The suction sides are connected to each other by suction pipes 5 and 6 via suction operation valves 3 and 4, and the discharge sides are connected to each other by discharge pipes 9 and 10 via discharge operation valves 7 and 8.

In addition, the compression element chambers 104 and 20 of the compressors 1 and 2
4 are connected to each other by a pressure/oil equalizing pipe 11, and on-off valves 119, 219 are attached to the connection portions between each compressor 1, 2 and the pressure/oil equalizing pipe 11.
Oil pumps 117 and 217 for compressor lubrication and on-off valves 119 and 219 are connected to oil pipes 118 and 21, respectively.
8.

Figure 2 is a sectional view showing details of the structure of the on-off valve.
Since the on-off valves 119 and 219 have the same structure, each member is given two different symbols.

The on-off valve body 120, 220 is the crank case 1
01, 201 with bolts 120b, 220b. One end of the main body 120, 220 is connected to the pressure/oil equalizing pipe 11, and the other end is connected to the pressure/oil equalizing hole 1.
10 inside the crankcase by 20a and 220a
It opens at 1,201. Equalizing pressure/oil hole 120
The oil pressure regulating valve cylinders 118a, 218a, which are arranged concentrically with the oil pipes 118, 220a,
18, or one end thereof is connected to the oil pipes 118, 218. A piston 121, 221 for hydraulic pressure adjustment is slidably provided in the cylinder 118a, 218a, and a spring 122,
222 is installed. Spring seats 123, 223
The pins 124 and 224 connect the cylinders 118a and 21.
It is fixed at 8a. Cylinder 118a, 21
On the outside of 8a, there is a pressure equalizing/oil equalizing hole 120a in the valve body,
Valve bodies 125, 22 arranged concentrically with 220a
5, and the valve bodies 125, 225 have pins 126, 22 provided in the cylinders 118a, 218a and passing through slit-shaped oil relief holes 127, 227.
6 is fixed to the pistons 121, 221, and can slide on the cylinders 118a, 218a in the axial direction.

Returning to FIG. 1 again, in order to be connected in parallel, the compressors 1 and 2 have their suction pipes 5 and 6 connected to an evaporator (not shown) via piping 12, and discharge pipes 9 and 2. 10 is connected to a condenser 14 by a refrigerant pipe 13. Furthermore, this condenser 14 is connected to the evaporator (not shown) through a throttle device (not shown).
A refrigeration cycle is constructed by connecting the

Next, to explain the operation, in FIG. 1, in a capacity control operation in which the compressor 2 is operated and the compressor 1 is stopped, the compression element chamber 2 of the compressor 2
Comparing the pressures in the motor chamber 203 and the pressure in the motor chamber 203, the compressor 2 is in operation, so the suction pipe 6, suction operation valve 4,
and motor chamber 2 due to pressure loss of motor 205.
03, especially the pressure of the oil reservoir 215 decreases.
On the other hand, since the stop-side compressor 1 is in a stopped state, there is no pressure loss in the suction pipe 5, suction operation valve 3, and motor 105, and the pressure at the branch point of the suction pipes 5 and 6 is
Operation valve 3, motor chamber 103, oil equalization check valve 11
4. It acts on the compression element chamber 204 of the compressor 2 during operation via the compression element chamber 104 and the pressure/oil equalization pipe 11, and since this value is about 100 to 400 mmAg, the oil equalization of the compressor 2 Check valve 214 is closed. In the compressor 2 during operation, the oil that has returned to the motor chamber 203 together with the suction gas cannot return from the oil reservoir 215 in the motor chamber 203 to the oil reservoir 216 in the compression element chamber 204, causing a serious problem in terms of lubrication of the compressor. Become.

This invention is intended to improve such drawbacks, and the on-off valve 119 of the compressor 1 that is stopped is closed, and the on-off valve 219 of the compressor 2 that is in operation is open. In other words, the oil pump 1 of the compressor 1 that is stopped
17 is inoperative, so no oil pressure is applied to the oil pressure regulating valve cylinder 118a of the on-off valve 119 that follows the oil pipe 118. Therefore, the piston 121 is pushed to the left in FIG. 2 by the action of the spring 122, and the pin 1
The valve body 125, which is connected to the piston 121 by 26, is also pushed to the left against the end of the valve body 120, closing the pressure equalization hole 120a. On the other hand, since the compressor 2 in operation is generating hydraulic pressure, the hydraulic pressure acts on the hydraulic cylinder 218a following the piping 218, and as shown in FIG.
1 moves to the right in the figure until the balance point between the hydraulic pressure and the spring force is reached, and when it moves to a predetermined position, the cylinder 218
Slit-shaped oil release hole 227 provided in the wall of a
Then, a certain amount of oil is returned into the crankcase 201 through a hole 228 provided in the valve body, and while keeping the oil pressure constant, the valve body 225, which is fixed by the piston 221 and the pin 226, is moved to the right. Equal pressure hole 2
An opening 229 is formed in 20a. Therefore, when the compressor is stopped, the spring pressure of the oil adjustment valve closes the pressure equalization/oil equalization pipe opening/closing valve, increasing the pressure in the compression element chamber of the operating compressor, and preventing oil return failure. It can be prevented.

When both compressors 1 and 2 are operating,
The oil pressure generated by each compressor opens each on-off valve to equalize the pressure and oil in both compression element chambers, allowing operation at a stable oil level.

As described above, according to this invention, even in so-called single-lung operation in which only one compressor of a parallel compression device is operated, it is possible to reliably return the oil returned from the suction pipe to the compression element chamber. Stable cooling operation can be performed without the risk of oil recovery being impossible and the sliding parts seizing up.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the parallel compression device of this invention, and Fig. 2 shows its hydraulic adjustment, pressure equalization, and
FIG. 3 is a sectional view showing the structure of the oil equalizing on-off valve, and FIG. 3 is a partial sectional view illustrating the operating state of the on-off valve shown in FIG. 2. 1, 2... Compressor, 5, 6... Suction pipe, 9, 1
0...Discharge pipe, 14...Evaporator, 118,218
... Oil piping, 118a, 218a ... Hydraulic pressure regulating valve cylinder, 119, 219 ... Opening/closing valve, 12
0,220...Valve body, 121,221...Piston, 122,222...Spring, 125,225
... Valve body.

Claims (1)

[Scope of Claim for Utility Model Registration] The crankcase is divided into a motor chamber and a compression element chamber by a partition wall, and oil during the refrigeration cycle is stored in the motor room side, and a non-return check for oil equalization is installed in the partition wall. Suction piping for a plurality of compressors configured to recover the oil to the compression element chamber side via a valve;
In addition to connecting discharge pipes in parallel, the compressor is provided with an oil equalizing/pressure equalizing pipe that communicates the compression element chambers with each other, and an oil pump for lubricating the sliding parts of the compressor, and stopping the compressor at a predetermined time. In a parallel compression device that controls capacity by causing the oil and pressure equalization pipe to open into the compression element chamber, the oil and pressure equalization pipe is inserted into the opening and closed by a spring force, and the oil and pressure equalization pipe is A parallel compression device characterized by comprising a valve body that is opened by introducing hydraulic pressure from an oil pump.