JP2551269B2 - Hermetic compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed compressor in which a motor and a compression element driven by the motor are housed in a hermetic casing having an oil sump, and a suction pipe and a discharge pipe are connected to the casing. Regarding the machine.

[0002]

2. Description of the Related Art Conventionally, a hermetic type compressor is, for example, an actual flat type
As shown in FIG. 4, and as shown in FIG. 4, a motor M is installed in the upper part of a closed casing C having an oil sump A in the bottom part thereof, and a compression element CP is installed in the lower part thereof. The discharge pipe B is opened to the side, and the compressed gas compressed by the compression element CP is supplied to the motor M.
The air gap G provided between the stator ST and the rotor RT, and the core cut portion H formed on the outer wall of the stator ST are passed and guided to the upper side of the motor M, and discharged from the discharge pipe B to the outside. I am trying to let you. Further, in the rotary hermetic compressor configured as described above, since the oil sump A is provided at the bottom of the casing C, when the outside air temperature is low when the operation is stopped, the oil is accumulated in the oil sump A. A so-called refrigerant stagnation may occur in which a large amount of liquid refrigerant is dissolved in oil. Therefore, when the compressor is started while the bed is sleeping, the oil is agitated by the rotation of the rotor RT of the motor M and the crankshaft K, and the sliding of the blade in the cylinder of the compression element CP. Forming will occur. Therefore, in the compressor, the electric heater D is disposed on the outer peripheral side of the casing C, and when the operation is stopped, the heater D is energized to raise the temperature in the casing C and to make liquid in the oil in the oil reservoir A. The refrigerant is prevented from melting.

[0003]

However, since the electric heater D has to be energized while the compressor is stopped, there is a problem in that wasteful electricity must be consumed to operate the compressor. However, when the outside air temperature is very low, it is not possible to prevent the stagnation by only heating the electric heater D, and as a result, it is not possible to completely prevent the forming at the time of start-up and the oil rises. This was a cause of seizure of the bearing and other sliding parts.

The present invention has been made in view of the above problems, and an object thereof is to reliably prevent a decrease in the oil level in the casing even when forming occurs in the casing when the compressor is started. An object of the present invention is to provide a hermetic compressor that can be used.

[0005]

In order to achieve the above object, the hermetic compressor of the present invention has a motor 12 in a hermetic casing 11 having an oil sump 11a and a compression element 14 driven by the motor 12. Is a hermetic compressor in which a suction pipe 15 and a discharge pipe 16 are connected to the casing 11, and discharge refrigerant is short-circuited to the suction pipe 15 between the discharge pipe 16 and the suction pipe 15. Since the bypass passage 6 is provided, a flow path control device 7 having a forming detection means and opening the bypass passage 6 to control the flow of the discharged refrigerant into a short-circuit flow to the suction pipe 15 when forming occurs is provided. is there.

In addition, at a connection portion of the bypass passage 6 with the discharge pipe 16, an inlet passage 72a connected with the discharge pipe 16 and an outlet passage 72b communicating with the system side are provided, and between the inlet passage 72a and the outlet passage 72b. And a valve main body 72 having an intake communication passage 72c connected to the bypass passage 6
And a forming responsive valve body 7 that is movably installed inside the valve body 72 and that opens the suction communication passage 72c to the inlet passage 72a in response to a refrigerant flow during forming.
3 is preferably provided.

[0007]

When the foaming refrigerant accompanied by oil flows out of the sealing casing 11 due to foaming in the sealing casing 11 at the time of start-up, the foaming refrigerant is bypassed by the flow path controller 7. Since it can flow to the passage 6 and can be short-circuited to the suction pipe 15 provided in the closed casing 11, the foamy refrigerant flowing out from the casing 11 can be immediately returned to the casing 11 without flowing to the system side. As a result, it is possible to prevent the lowering of the oil level of the oil reservoir 11a due to forming. Further, since the discharge pipe 16 is short-circuited with the suction pipe 15 via the bypass 6 during forming, not only the high pressure dome type rotary compressor but also the low pressure dome type reciprocating compressor is used. Can also be applied. Further, since the high-pressure foamy refrigerant discharged from the compressor is short-circuited to the suction pipe 16,
In the case of a rotary compressor, the high pressure of the gas discharged from the compression element 14 can be rapidly increased, so that the pressure in the casing 11 can be increased quickly, and the compression element 14
Since the back pressure of the blade installed inside can be immediately increased, the jumping of the blade at the time of start-up can be reduced, the noise due to this jumping can be reduced accordingly, and the high-temperature foam discharged from the discharge pipe 16 can be reduced. By short-circuiting the refrigerant to the suction pipe 15, even if the liquid refrigerant in which oil is melted flows into the suction pipe 15 from the evaporator on the system side, the flow rate of the liquid refrigerant can be limited, and the liquid refrigerant can be limited. Can be heated and gasified by the hot foamy refrigerant short-circuited from the discharge pipe 16 to the suction pipe 15, so that the liquid refrigerant is sucked into the compression element 14 and formed in the compression element 14. It is possible to prevent the occurrence of, and it is possible to shorten the time until forming is eliminated.

In addition, at the connecting portion of the bypass passage 6 with the discharge pipe 16, an inlet passage 72a connected to the discharge pipe 16 and an outlet passage 72b communicating with the system side and between the inlet passage 72a and the outlet passage 72b are located. And a valve main body 72 having an intake communication passage 72c connected to the bypass passage 6
And a forming responsive valve body 7 that is movably installed inside the valve body 72 and that opens the suction communication passage 72c to the inlet passage 72a in response to a refrigerant flow during forming.
By providing the flow path control valve 71 including 3 and 3, by utilizing the difference in flow resistance between the foamy refrigerant during forming and the gas refrigerant when not forming,
The flow passage control valve 71 can be operated to switch the flow passages. Therefore, it is not necessary to electrically control the flow passage control device, and the flow passage can be controlled with a simple structure.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A hermetic compressor according to the present invention will be described below with reference to the drawings. FIG. 1 shows a refrigerating apparatus including a hermetic compressor 1, to which a condenser 2, an expansion mechanism 3, an evaporator 4 and an accumulator 5 are connected by a refrigerant pipe 8 as shown in the figure. Form a refrigeration cycle.

The hermetic compressor 1 has a stator 12a and a rotor 12b above the interior of the hermetic casing 11.
A motor 12 formed of the
Compression element 14 interlockingly coupled to drive shaft 13 extending from 2b
And the drive shaft 13 associated with the drive of the motor 12.
Suction pipe 15 connected to the casing 11 by rotating
Compressing the gas refrigerant sucked into the compression element 14 from
The compressed gas refrigerant is discharged into the casing 11,
The discharged compressed gas refrigerant is allowed to flow out to the condenser 2 from a discharge pipe 16 connected to the casing 11.

Further, an oil supply passage (not shown) extending in the axial direction is formed in the drive shaft 13, and an oil sump 1 formed in the bottom portion of the closed casing 1 at the lower end opening of the oil supply passage.
1a is provided, and when the drive shaft 13 rotates, the oil pickup 17 pumps up the lubricating oil in the oil sump 11a to the sliding parts of the compression element 14 with respect to the drive shaft 13. I am trying to supply it.

In the above hermetic compressor, however, the bypass passage 6 for short-circuiting the discharge refrigerant to the suction pipe 15 is provided between the discharge pipe 16 and the suction pipe 15, and the forming detection means is provided to form the foam. At this time, the bypass passage 6 is opened to allow the flow of the discharged refrigerant to flow into the suction pipe 1.
The flow passage control device 7 for controlling the short-circuit flow to the discharge pipe 16 is provided, and the flow passage control device 7 shown in FIG. 1 has the discharge pipe 16 at the connection portion of the bypass passage 6 with the discharge pipe 16. An inlet passage 72a connected to the system and an outlet passage 72b communicating with the system side, and an intake communication passage 72 located between the inlet passage 72a and the outlet passage 72b and connected to the bypass passage 6
a valve body 72 including a valve body c, and a forming responsive valve body 73 that is movably installed in the valve body 72 and that opens the suction communication passage 72c to the inlet passage 72a in response to a refrigerant flow during forming. It is configured by connecting the flow path control valve 71 provided with and.

That is, the flow passage control valve 71 constituting the flow passage control device 7 is connected to the discharge pipe 16 as shown in FIG. 1 and FIG. The valve main body 72 has a tubular shape extending in the longitudinal direction, the inlet passage 72a connected to the discharge pipe 16 is formed at one end in the longitudinal direction, and the other end communicates with the condenser 2. The outlet passage 72b is formed, and the inlet passage 7a is formed between the inlet passage 72a and the outlet passage 72b.
2a and the outlet passage 72b are formed with a body portion 72d having a diameter larger than each inner diameter, and the suction communication passage 72c projecting perpendicularly to the longitudinal direction is formed on the inlet passage 72a side at the longitudinal intermediate portion of the body portion 72d. To do. The forming response valve body 73 is in contact with the inner peripheral surface of the body portion 72d to close the suction communication passage 72c, and has a cylindrical suction communication passage opening / closing portion 73a, and the suction communication passage opening / closing portion 73a. An outlet passage opening / closing portion 73b is formed so as to continuously project from an end surface of the passage opening / closing portion 73a on the outlet passage 72b side. The outlet passage opening / closing portion 73b has a pin shape having an outer diameter that can be fitted into the outlet passage 72b. And a through hole 73c extending in the axial direction is formed in the center of the pin portion. Further, the suction communication passage opening / closing portion 73 is provided outside the outlet passage opening / closing portion 73b.
As shown in FIG. 3, a plurality of circulation ports 73d are formed on the end face of the outlet passage side of a.

The forming response valve body 73 is installed inside the valve body 72, and the forming response valve body 73 is biased toward the outlet passage 72b side of the forming response valve body 73 toward the inlet passage 72a side. The flow passage control valve 71 is configured by disposing a spring 74 that allows the forming response valve body 73 to move on the body portion 72d of the valve body 72.

Further, the flow passage control valve 71 described above is provided with the inlet passage 72 of the flow passage control valve 71 as shown in FIG.
a is connected to the discharge pipe 16, the outlet passage 72b is connected to the refrigerant pipe 8 communicating with the condenser 2, and the suction communication passage 72c is connected at one end to the inlet pipe 51 of the accumulator 5. The bypass path 6 is connected. The bypass passage 6 is provided with a capillary tube 61 for reducing the pressure of the refrigerant flowing out from the passage control valve 71. Further, although the bypass passage 6 is connected to the inlet pipe 51 of the accumulator 5, the bypass passage 6 may be directly connected to the suction pipe 15 in the case where the accumulator is not provided.

According to the hermetic compressor of the present invention, however, the flow resistance when the gas refrigerant flows through the through hole 73c and the flow port 73d of the flow path control valve 71 is small when no forming occurs. So, as shown in Figure 1,
The forming response valve body 73 is urged by the spring 74 to close the suction communication passage 72c. Therefore, the gas refrigerant flowing in from the inlet passage 72a is discharged from the forming response valve body. 73 through the through hole 73c and the flow port 73d, and the outlet passage 72
The refrigerant flows out from b to the refrigerant pipe 8, and the normal refrigeration cycle operation is performed.

Further, when the compressor 1 is started from a stopped state, the temperature inside the compressor 1 is low, and when forming occurs due to the start, the discharge pipe 1 of the compressor 1
6, a foamy refrigerant flows out, and this foamy refrigerant flows from the inlet passage 72a of the flow passage control valve 71 into the primary side of the forming response valve body 73, and the through hole 73c and
Attempts to pass through the circulation port 73d formed at the end surface of the suction communication passage opening / closing portion 73a. However, since the foamy refrigerant due to forming contains oil, it has a large circulation resistance and is difficult to pass through. Therefore, the primary pressure of the forming response valve body 73 increases, and this pressure causes the forming response valve body 73 to move to the outlet passage 72b.
To the side, the suction communication passage 72c closed by the suction communication passage opening / closing portion 73a is opened, and the outlet passage closing portion 73b of the forming response valve body 73 closes the outlet passage 72b. . By doing so, the foamy refrigerant flowing into the flow path control valve 71 is
While the forming is continuing, it does not flow into the condenser 2 but flows out from the suction communication passage 72c into the bypass passage 6 and is decompressed by the passage of the capillary tube 61 in the bypass passage 6 to obtain the accumulator. 5 and is sucked again into the casing 11 of the compressor 1 without flowing to the system side, and the oil sump 11a
Is returned to. Therefore, even if the lubricating oil is formed, it can be immediately recovered without flowing to the system side, so that the oil level in the oil sump 11a can be reduced and it is possible to prevent the bearing and other sliding parts from seizing due to insufficient oil supply. However, it is possible to eliminate the need for using an electric heater as in the conventional example. At this time, since the through hole 73c formed in the outlet passage opening / closing portion 73b allows a small amount of the liquid to flow to the condenser 2 side, the flow passage control valve 71 is not damaged by the excessive pressure of the foamy refrigerant. .
Then, when the forming is lost and the gas refrigerant is discharged, the through hole 73c and the flow port 73d of the forming response valve body 73 in the flow path control valve 71.
Since the flow resistance when flowing through is reduced, the primary pressure of the forming response valve body 73 is reduced, and as a result, the forming response valve body 73 moves toward the inlet passage 72a side by the bias of the spring 74. The inlet passage 72c is closed and the outlet passage 72b is opened.

Further, since the foamy refrigerant is returned from the discharge pipe 16 to the accumulator 5, it is possible to limit the suction amount of the liquid refrigerant containing the oil flowing from the evaporator 4, and Since the liquid refrigerant can be heated, the liquid refrigerant can be evaporated and gasified in the accumulator 5, so that the liquid refrigerant is sucked into the compression element 14 to form in the compression element 14. Can be prevented, and the time until forming is eliminated can be shortened.

Further, since the high-pressure foamy refrigerant discharged from the casing 1 is short-circuited to the suction pipe 16,
When it is applied to the rotary compressor as described above, the high pressure of the gas discharged from the compression element 14 can be rapidly increased, so that the pressure in the casing 11 can be increased quickly, and the blade installed in the compression element 14 can be increased. Since the back pressure of the blade can be immediately increased, the jumping of the blade at the time of starting can be reduced, and the noise due to this jumping can be reduced accordingly.

Further, in the above-described embodiment, the flow passage control of the flow passage control device 7 is performed by the forming response valve body 7.
The pressure on the primary side of the forming response valve body 73 is changed by utilizing the difference in flow resistance between the foamy refrigerant and the gas refrigerant passing through the through hole 73c and the flow port 72d formed in No. This is performed by operating the forming response valve body 73 by the difference in force from the urging force of the spring 74, but it is necessary to transmit ultrasonic waves to the inside of the casing and receive its reflected wave. A detection device is provided to detect the forming by comparing the time with the time required during normal operation, and the flow to the condenser 2 and the bypass 6 at the connection portion between the discharge pipe 16 and the bypass 6. By providing a three-way solenoid valve that switches the flow,
The three-way solenoid valve may be controlled to open to the bypass path 6 side when the detection device detects forming. Further, instead of the three-way solenoid valve, two electromagnetic two-way valves are provided on the condenser 2 side of the discharge pipe 16 and the bypass passage 6 with respect to the connecting portion between the discharge pipe 16 and the bypass passage 6. It is also possible to provide and open only the electromagnetic two-way valve on the side of the bypass 6 by the detection of the forming of the detection device. Further, instead of this electromagnetic two-way valve, a flow rate control valve that changes the flow rate to the condenser 2 and the bypass path 6 may be used.

[0021]

As described above, in the hermetic compressor of the present invention, the bypass passage 6 for short-circuiting the discharge refrigerant to the suction pipe 15 is provided between the discharge pipe 16 and the suction pipe 15, and the forming process is performed. Since there is provided a flow path control device 7 having a detecting means and opening the bypass path 6 when forming occurs and controlling the flow of the discharge refrigerant into a short-circuit flow to the suction pipe 15, at the time of start-up, the inside of the closed casing 11 is provided. Even if the foaming refrigerant accompanied by oil flows out of the closed casing 11 due to the forming, the foaming refrigerant is caused to flow into the bypass passage 6 by the flow path control device 7, and the closed casing of the compressor. Since it can be short-circuited to the suction pipe 15 provided in 11, the foamy refrigerant flowing out of the compressor can be immediately returned to the casing 11 without flowing to the system side. As a result, it is possible to prevent the oil surface of the oil sump 11a from being lowered due to forming, and to prevent seizure of the bearing and other sliding parts due to insufficient oil supply. The need to use it can be eliminated. Further, during forming, the discharge pipe 16 is connected to the suction pipe 15 by the bypass passage 6.
Since it has a structure of short-circuiting via the, it can be applied not only to the high pressure dome type rotary compressor but also to the low pressure dome type reciprocating compressor. Further, since the high-pressure foamy refrigerant discharged from the compressor is short-circuited to the suction pipe 16, particularly in the case of the rotary compressor, the high pressure of the gas discharged from the compression element 14 can be rapidly increased. As a result, the pressure in the casing 11 can be increased quickly, and the back pressure of the blade installed in the compression element 14 can be immediately increased, so that the jumping of the blade at the time of start-up can be reduced and the noise due to this jumping can be reduced. Further, by short-circuiting the high-temperature foamy refrigerant discharged from the discharge pipe 16 to the suction pipe 15, even if the liquid refrigerant mixed with oil is sucked from the evaporator on the system side, this liquid refrigerant Can be heated and gasified, for example in an accumulator,
It is possible to prevent the liquid refrigerant from being sucked into the compression element 14 to cause the forming in the compression element 14, and to shorten the time until the forming disappears.

In addition, at the connecting portion of the bypass passage 6 with the discharge pipe 16, an inlet passage 72a connected with the discharge pipe 16 and an outlet passage 72b communicating with the system side, and between the inlet passage 72a and the outlet passage 72b are located. And a valve main body 72 having an intake communication passage 72c connected to the bypass passage 6
And a forming responsive valve body 7 that is movably installed inside the valve body 72 and that opens the suction communication passage 72c to the inlet passage 72a in response to a refrigerant flow during forming.
By providing the flow path control valve 71 including 3 and 3, by utilizing the difference in flow resistance between the foamy refrigerant during forming and the gas refrigerant when not forming,
The flow passage control valve 71 can be operated to switch the flow passages. Therefore, it is not necessary to electrically control the flow passage control device, and the flow passage can be controlled with a simple structure.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a refrigerating cycle of a refrigerating apparatus using a hermetic compressor of the present invention.

FIG. 2 is a cross-sectional view showing the operation of the hermetic compressor of the present invention during the forming of the flow path control valve.

3 is a cross-sectional view taken along line XX of the flow path control valve of FIG.

FIG. 4 is an explanatory view showing a conventional example.

[Explanation of symbols]

 11 Airtight casing 11a Oil sump 12 Motor 14 Compression element 15 Suction pipe 16 Discharge pipe 6 Bypass passage 7 Flow passage control device 71 Flow passage control valve 72 Valve body 72a Inlet passage 72b Outlet passage 72c Intake communication passage 73 Forming response valve

Claims (2)

(57) [Claims] 1. A motor 12 and a compression element 14 driven by the motor 12 are housed in a closed casing 11 having an oil sump 11a, and a suction pipe 15 is provided in the casing 11.
And a discharge pipe 16 are connected, and a bypass passage 6 for short-circuiting a discharge refrigerant to the suction pipe 15 is provided between the discharge pipe 16 and the suction pipe 15, and a forming detection means is provided. When the foaming occurs, the bypass passage 6 is opened to allow the flow of the discharged refrigerant to flow into the suction pipe 1.
A hermetic compressor characterized in that a flow path control device (7) for controlling a short circuit flow to (5) is provided. 2. The connecting portion of the bypass passage 6 with the discharge pipe 16,
An inlet passage 72a connected to the discharge pipe 16, an outlet passage 72b communicating with the system side, and these inlet passages 72a,
A valve main body 72 having an intake communication passage 72c connected to the bypass passage 6 and located between the outlet passages 72b, and movably installed inside the valve main body 72, in response to a refrigerant flow during forming, The hermetic compressor according to claim 1, further comprising a flow passage control valve 71 having a forming response valve body 73 that opens the suction communication passage 72c with respect to the inlet passage 72a.