JPH08159032A - Electric compressor - Google Patents

Abstract

PURPOSE: To improve the lubricity of oil to each bearing sliding part under the flooded start operating condition and to improve the reliability in the use of a compressor. CONSTITUTION: An electric compressor is so constructed that a compressing mechanism part 7, a motor 4 for driving the compressing mechanism part 7, a main shaft 23 and a crankshaft 22 for transmitting the turning force of the motor 4 to the compressing mechanism part 7, and an oil pump 24 for supplying lubricating oil to the sliding part of the compressing mechanism part 7 are installed in a closed container 1 having an oil sump at the base thereof, and a mixing rod 30 driven by the rotation of the main shaft 23 is provided extending from the oil pump 24 along the center line of the main shaft in the discharge direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor used for cooling and heating, or a cooling device such as a refrigerator.

[0002]

2. Description of the Related Art Conventionally, electric compressors such as rotary compressors and scroll compressors have been used as cooling devices for cooling and heating, or refrigerators.

Next, a scroll compressor as a conventional representative example will be described with reference to FIG. 6 (JP-A-2-27186). In the figure, the shell 51 is configured by a tubular body having a central axis line extending in the horizontal direction. The shell 51 is provided at its bottom with an oil sump 52 for storing oil for lubricating each bearing sliding portion, and inside thereof is provided with a compression mechanism assembly 53 for compressing a working fluid. The compression mechanism assembly 53 is composed of a fixed scroll 54 and an orbiting scroll 55 which are eccentrically combined with each other, and an assembly having a motor stator 56 and a motor rotor 57 which drive the orbiting scroll 55 of these scrolls. ing. The fixed scroll 54 is
Discharge port 54a, gas suction port 54b and swirl wrap 5
4c and is fixed to the bearing support 58. Reference numeral 59 is a main shaft that connects the orbiting scroll 55, is supported by the bearing support 58, is provided in the shell 51, and is configured to rotate by a motor A including the motor stator 56 and a motor rotor 57. There is. The main shaft 59 has an oil supply passage 59 which opens in the bearing sliding portion 34 and the lower end portion and extends in the axial direction.
An oil hole 59b communicating with a and opening in the radial direction is provided. Reference numeral 60 denotes a housing having a tubular body 61 facing the oil sump 27, which is provided in the axial direction of the orbiting scroll 55, and the motor stator 56 of the motor A is fixed by bolts or the like. The tubular body of the housing 60 communicates with a suction space of a pump, which will be described later, through the first oil hole 60a. Reference numeral 62 denotes a positive displacement pump driven by rotation of the main shaft 59, which is a trochoid pump having a pump stator 62a and a pump motor 62b, and is housed inside the housing 60. 66
Is a suction pipe for sucking the working fluid into the shell, which is located in the vicinity of the coil end of the motor stator 56 and is mounted on the motor side end plate of the shell 51 by, for example, brazing.

In the scroll compressor thus constructed, when the motor A is driven, the working fluid gas is drawn from the suction pipe 66 into the suction space above the coil end of the motor stator 56 as shown by the solid arrow in FIG. After being sucked into 29, it passes through the gap between the outer peripheral surface of the motor stator 56 and the inner peripheral surface of the shell 51 to cool the motor, and then passes through the notch 58c above the bearing support 58 and passes through the gas suction port 54.
It is taken into the compression chamber 13 from b. On the other hand, the oil flows as shown by the wavy arrow in FIG. That is, when the pump rotor 62b is rotated by the rotation of the main shaft 59, the pump 62 is driven by the driven of the pump stator 62a, so that the oil flows from the pipe body 61 into the suction space of the pump 62 through the first oil hole. From the discharge chamber of the pump 62 to the frame 6
4 is oil-fed to the oil supply passage 59a through the oil hole 59c, and the recess 58b of the bearing support 58 and the oil hole 59b of the main shaft 59.
Is supplied to the bearing sliding portions 18, 34, 37, 38 via. Then, the oil flows out from the bearing sliding portion 18, flows into the oil discharge chamber 58a, and returns to the oil sump 52 from the opening of the oil discharge chamber 58a. As a result, when the lubricating oil is compatible with the refrigerant, the lubricating oil is well dissolved in the refrigerant during steady operation, and the oil is pumped up by the pump, so that it is possible to sufficiently supply each bearing sliding portion.

[0005]

However, when the ambient temperature of the compressor is extremely low and the compressor is not operated for a long period of time, the lubricating oil and the refrigerant in the compressor are close to the separated state and the oil is not restarted. Since the specific gravity of the oil is lighter than that of the refrigerant, the oil pump does not suck much oil, resulting in poor lubricity for the sliding parts, resulting in burnout and a decrease in reliability in use of the compressor. there were.

The present invention has been made in view of such circumstances, and it is possible to prevent the occurrence of burnout at the sliding portions of the bearings, and thus to reliably improve the reliability in use of the compressor. A compressor is provided.

[0007]

In order to solve the above problems, the present invention provides, as a first means, a compression mechanism portion and a driving mechanism for the compression mechanism portion in a closed container having an oil sump at the bottom. An electric motor, a main shaft and a crank shaft for transmitting the rotational force of the electric motor to the compression mechanism section, and an oil pump for supplying lubricating oil to the sliding section of the compression mechanism section, and the oil pump is installed on the center line of the main axis. A stirring rod is provided along which is driven by the rotation of the main shaft in the discharge direction.

Further, as a second means, a stirring rod is provided in the suction pipe of the oil pump which faces the oil sump.

Further, as a third means, a heating device is provided in the oil sump portion of the space where the discharge pipe is present.

[0010]

The operation of the above means is as described below.

According to the above-mentioned first means, when the oil and the refrigerant are accumulated up to the spindle height level, even when the oil forms a phase above the refrigerant, the two phases of the compressor are separated. With the rotation of the main shaft due to startup, the stirring rod connected also rotates,
The phases can be agitated to create a mixture of oil and refrigerant. As a result, oil having a relatively high viscosity is sucked into the oil pump, and the lubricity of the sliding portion can be improved.

According to the second means, even if the level at which the oil and the refrigerant are accumulated is below the main shaft height, the stirring pipe is provided in the suction pipe body of the oil pump, so that the compression at the time of start-up or operation is performed. The vibration of the machine body is transmitted to the stirring rod to promote the stirring of the oil and the refrigerant, so that the oil having a relatively high viscosity can be sucked.

According to the third means, the oil and the refrigerant accumulated in the vicinity of the oil pump are heated to evaporate the refrigerant, so that the oil pump can suck the oil having a relatively high viscosity. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In the figure, 1 is a closed container, 2 is a suction pipe, and 3 is a discharge pipe. Reference numeral 4 is an electric motor, 5 is a stator of the electric motor, 6 is a rotor of the electric motor, and 7 is a compression mechanism portion. Reference numeral 23 is a main shaft, and 22 is a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism section 7. Since this embodiment is a scroll compressor, the compression mechanism section 7 is composed of an orbiting scroll 13, a fixed scroll 8, an orbiting bearing 18, a bearing component 19, and the like. The bearing component 19 supports the large shaft portion of the crankshaft 22. A partition member 12 is fixed to the closed container 1, and the closed container 1 and the discharge pipe 3 are provided in the space where the compression mechanism portion 7 exists.
The space is divided into two.

At the center of the partition member 12, a main shaft 23
A second bearing 29 is mounted to support one end of the. Further, the partition member 12 has a gas ejection hole 31 through which the refrigerant gas passes.
Is provided. A gas collision plate 32 is provided at a position facing the gas ejection hole 31. Reference numeral 24 denotes an oil pump that supplies lubricating oil to the sliding portion of the compression mechanism unit 7. The stirring rod 3 is driven by rotation of the main shaft in the discharge direction from the oil pump 24 along the center line of the main shaft 23.
0 is provided. Further, the suction pipe 24 of the oil pump 24
The gas impingement plate 32 is constructed by extending the suction plate provided with a. Reference numeral 28 denotes a box body that surrounds the circumference of the discharge pipe 3, and the discharge pipe 3 is formed by bending upward inside the box body 28.

Next, the operation of the scroll compressor having such a configuration will be described. The flow of the refrigerant gas is indicated by a thick arrow.

As the electric motor rotor 6 rotates, the crankshaft 22 and the orbiting bearing 18 rotate. As a result, the orbiting scroll 13 orbits around the fixed scroll 8, and the orbiting scroll blade 15 and the fixed scroll blade 9 rotate. A compression effect occurs in the enclosed space. Then, the low-pressure refrigerant gas is sucked from the suction pipe 2, compressed in the space between the orbiting scroll blade 15 and the fixed scroll blade 9, and discharged into the discharge hole 10.
Is discharged into the closed container 1. After that, the high-pressure refrigerant gas passes through the gas passage 26 provided in the compression mechanism portion 7 and the gas passage 27 of the electric motor stator 5, and then passes around the oil pump 24 and around the box body 28. ,
Finally, it goes out of the closed container 1 through the discharge pipe 3.

On the other hand, the flow of oil is indicated by a thin arrow. During normal operation, the oil 25 accumulated in the lower part of the closed container 1 is sucked by the oil pump 24 and, after being pressurized, passes through the oil passage 33 of the crankshaft 22 and first between the orbiting scroll shaft 17 and the orbiting bearing 18. Lubricate the sliding surface. After this,
The oil reaches the back surface of the end plate 14, but since the annular seal member 21 is arranged on the back surface of the end plate 14, the oil is dammed up by the seal member 21. The oil on the back surface of the end plate 14 then flows while lubricating the sliding portion between the large shaft portion of the crankshaft 22 and the bearing component 7, is discharged into the bearing cover 27, and then returns to the inside of the closed container 1.

However, such an operation is established during the steady operation, and for example, the ambient temperature of the compressor is very low, and the operation is stopped, and the oil and the refrigerant are laid in the compressor. In some cases, even if the lubricating oil is compatible with the refrigerant, depending on such conditions,
Oil separates from the refrigerant and may form a phase above the refrigerant due to its low specific gravity. As a result, at the time of start-up, the vicinity of the suction pipe 24a of the oil pump 24 sucks a refrigerant having a small oil phase and a low viscosity, which also causes a decrease in the lubricity of the sliding portion. Therefore, in the first embodiment, the oil pump 24 is provided with the stirring rod 30 so as to be interlocked with the rotation of the main shaft 23 at the time of start-up, and the rotation of the stirring rod 30 causes the oil reservoir 2 to rotate.
The refrigerant and oil of No. 5 are mixed with each other, and the oil having a lighter specific gravity at the upper portion also moves to the lower portion, is sucked into the oil pump, and the lubricity to each sliding portion can be improved.

Further, as a second embodiment shown in FIG.
Since the storage level 25 of oil and refrigerant may change depending on the operating conditions of the compressor, for example, when the storage level 25 is below the height level of the main shaft 23 and is relatively small, in the first embodiment, Since the stirring rod 30 is above the accumulation level 25, the lubrication effect is reduced. Therefore, by attaching the stirring rod 30a to the suction pipe 24a of the oil pump 24, even when the accumulation amount of oil and refrigerant is small, the compressor is started or The vibration during operation can vibrate the stirring rod 30a to mix the oil above the refrigerant into the vicinity of the lower part of the pump suction pipe 24a to lubricate the oil.

In the third embodiment, when the lubricating oil used is incompatible with the refrigerant, phase separation occurs regardless of operating conditions. By stirring the incompatible oil that is formed, it is passed to the bottom of the compressor, and good lubrication can be performed through the oil pump.

In the fourth embodiment, as shown in FIG. 3, when the refrigerant and the oil are mixed or separated in the oil sump 25 portion of the space where the discharge pipe exists, a heater or the like is provided in the vicinity thereof. By providing and heating the heating device 34, only the refrigerant in the vicinity of the oil pump 24 evaporates, and as a result, lubricating oil remains, and oil of relatively high viscosity is sucked into the oil pump, and the lubricity of each sliding portion is increased. Can be improved.

4 and 5 show a typical shape of the stirring rod in this embodiment, the present invention is not limited to this, and other shapes may be used. You can freely change the type of rod.

[0025]

As described above, according to the present invention,
In a closed container having an oil sump at the bottom, a compression mechanism section, an electric motor for driving the compression mechanism section, a main shaft and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism section,
An oil pump that supplies lubricating oil is attached to the sliding portion of the compression mechanism, and a stirring rod that is driven by the rotation of the spindle in the discharge direction along the spindle centerline from the oil pump is provided to perform various operations. When the oil and refrigerant are in a reservoir state that meets the conditions, the oil is mixed with the refrigerant by stirring, and oil that always maintains a certain viscosity is collected in the vicinity of the oil pump suction pipe. Good lubrication of moving parts can be achieved.

Further, by providing a stirring rod on the suction pipe of the oil pump facing the oil sump, even if the level of oil and refrigerant accumulated at the bottom of the compressor is small, the stirring on the lower side of the oil pump is performed. And the lubricity can be improved.

Further, when the refrigerant to be used is an HFC type (hydrofluorocarbon) and the lubricating oil is an incompatible oil to the refrigerant, the above-mentioned effects are further enhanced, and the sliding parts of the oil are It is possible to improve the lubricity of.

Further, by providing the heating device in the oil sump portion of the space where the discharge pipe is present, the refrigerant remaining in the oil sump is heated and evaporated, and the relatively viscous oil having good lubrication is slid to the sliding portion. Can be supplied.

[Brief description of drawings]

FIG. 1 is a sectional view of a scroll compressor showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of essential parts near an oil pump of a scroll compressor showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of an essential part near an oil pump of a scroll compressor showing a fourth embodiment of the present invention.

FIG. 4 is a schematic diagram of a stirring rod according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a stirring rod according to an embodiment of the present invention.

FIG. 6A is a cross-sectional view of a conventional scroll compressor and FIG. 6B is an oil pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airtight container 2 Suction pipe 3 Discharge pipe 4 Electric motor 7 Compression mechanism part 22 Crankshaft 23 Main shaft 24 Oil pump 25 Oil sump part 30 Stirring bar 34 Heating device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Nigami 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A compression mechanism section, an electric motor for driving the compression mechanism section, a main shaft and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism section, in a closed container having an oil sump at the bottom. An oil pump for supplying lubricating oil to the sliding portion of the compression mechanism, and a stirring rod driven by rotation of the spindle in the discharge direction along the spindle centerline from the oil pump. Electric compressor to do. 2. An electric compressor characterized in that a stirring rod is provided on a suction pipe of an oil pump which faces an oil sump. 3. The electric compressor according to claim 1, wherein the refrigerant used is an HFC system (hydrofluorocarbon), and the lubricating oil is an incompatible oil with the refrigerant. 4. The electric compressor according to claim 1, 2 or 3, wherein a heating device is provided in an oil sump portion of the space where the discharge pipe is present.