JP4024521B2 - Scroll compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scroll compressor used in a refrigeration apparatus or an air conditioner, and more particularly to lubrication of a bearing thereof.
[0002]
[Prior art]
FIG. 5 is a cross-sectional view showing a configuration of a conventional scroll compressor described in, for example, Japanese Patent No. 289439. In this figure, reference numeral 1 denotes an airtight container that constitutes a casing of the scroll compressor, and an oil sump 2 for lubrication is formed at the bottom.
3 is a frame fixed to the sealed container 1 at the upper part of the sealed container, 4 is a fixed scroll fixed to the frame, 5 is arranged to face the fixed scroll 4 and constitutes a scroll type fluid compression mechanism together with the fixed scroll 4 An orbiting scroll 6 is integrally formed with the frame 3 and is a thrust bearing for axially supporting the orbiting scroll 5 from below, and 7 is formed at the center of the frame 3 to support a motor spindle which will be described later. A main bearing 8 is a motor for driving the fluid compression mechanism, and includes a cylindrical stator 9 fixed to the hermetic container 1, a rotor 10 disposed in the stator 9, and a central portion of the rotor 10. The upper end of the main shaft 11 is supported by the main bearing 7 and is coupled to the orbiting scroll 5.
[0003]
Further, a through hole 12 for supplying lubricating oil is provided in the central portion of the main shaft 11.
Reference numeral 13 denotes a sub-frame fixed to the sealed container 1 above the oil sump 2 at the lower part of the sealed container 1, and a detailed configuration of this part is shown in FIG. That is, 13a is a projecting portion formed so as to surround the main shaft 11 at the center of the subframe, 13b is a through portion formed in the projecting portion 13a, and the lower end of the main shaft 11 enters the inside thereof. Yes. 14 is a ball bearing that is mounted on the through-hole 13b and rotatably supports the lower end of the main shaft 11, and 15 is an oil pump that is mounted on the through-hole 13b at the lower part of the ball bearing and is provided at the lower end of the main shaft 11. A pump casing 16 through which the pump shaft 11a passes, a positive displacement pump 17 that is rotationally driven by the pump shaft 11a, a pump port 18, and a pump cover 19 that fixes the pump casing 16 and the pump port 18 are configured.
[0004]
The pump port 18 is provided with a suction port 18a and a discharge port 18b communicating with the through hole 12 of the main shaft 11, and the pump cover 19 is provided with an oil drain passage 19a. 20 is an oil pipe that communicates the oil reservoir 2 with the suction port 18a of the pump port 18, and 21 is an oil supply hole that is provided above the ball bearing 14 so as to open from the through hole 12 of the main shaft 11 in the radial direction of the main shaft 11. It is.
[0005]
Next, the operation will be described. When power is supplied to the stator 9 of the motor 8, the rotor 10 of the motor 8 generates torque and rotates with the main shaft 11 to revolve the orbiting scroll 5, and the fixed scroll 4 and the orbiting scroll 5 are combined. As is well known, the volume of the compression chamber (not shown) formed is sequentially reduced, and the low-temperature and low-pressure suction refrigerant gas is discharged as a high-temperature and high-pressure gas. The pump shaft 11 a is also rotated by the rotation of the main shaft 11 to drive the positive displacement pump 17, so that the lubricating oil in the oil sump 2 is guided from the suction port 18 a of the pump port 18 to the positive displacement pump 17 through the oil pipe 20. After being discharged to the discharge port 18b once, it is pumped up to the through hole 12. A part of the pumped-up lubricating oil is supplied to the ball bearing 14 through the oil supply hole 21 at the upper part of the ball bearing 14 and lubricated, and then discharged from the oil discharge passage 19a to the oil sump 2. Further, another part of the lubricating oil pumped up to the through hole 12 is pumped up to the upper end of the main shaft 11, lubricates the thrust bearing 6 and the like, passes through the oil return passage 22 provided in the frame 3, and holds the oil sump 2. Returned to.
[0006]
[Problems to be solved by the invention]
Since the conventional scroll compressor is configured as described above, there is a problem in that the ball bearing is damaged when a failure in oil supply to the ball bearing due to gas biting of the pump occurs. In addition, during operation, the temperature difference between the ball and raceway of the ball bearing and the high temperature of the lubricating oil lower the oil viscosity, causing abnormal wear on the ball and raceway.
[0007]
The present invention has been made to solve the above-described problems, and solves the shortage of oil supply to the ball bearing and deteriorates the lubricity due to a decrease in the oil viscosity due to an increase in the lubricating oil temperature. An object of the present invention is to obtain a highly reliable scroll compressor that can prevent the above.
[0008]
[Means for Solving the Problems]
The scroll compressor according to the present invention includes a sealed container having an oil sump formed at the bottom, a scroll-type fluid compression mechanism disposed at an upper portion of the sealed container, and the fluid compression mechanism disposed in the sealed container. A motor having a main shaft for driving the mechanism and having a through hole for supplying lubricating oil in the main shaft, a bearing provided in the vicinity of the oil sump for rotatably supporting the main shaft, and driven by the main shaft And an oil pump for supplying the lubricating oil in the oil reservoir to the fluid compression mechanism and the bearing through the through hole, and the lubricating oil supplied to the bearing is circulated from below to above the bearing. In addition, a bearing cover is provided above the bearing .
[0012]
In the scroll compressor according to the present invention, an oil supply hole that opens from the through hole of the main shaft in the radial direction of the main shaft is provided below the bearing.
[0014]
In the scroll compressor according to the present invention, the bearing cover is fixed to a protruding portion formed at the center portion of the subframe so that a minute gap is formed between the bearing cover and the main shaft.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a main part showing the configuration of the scroll compressor according to the first embodiment, and shows a peripheral part of a subframe in the lower half of the scroll compressor. In addition, since the upper half part of a scroll compressor is the same structure as FIG. 5, illustration and description are abbreviate | omitted.
In this figure, reference numeral 1 denotes an airtight container that constitutes a casing of the scroll compressor, and an oil sump 2 for lubrication is formed at the bottom. Reference numeral 11 denotes a main shaft of the motor 8 described with reference to FIG. 5, and a through hole 12 for supplying lubricating oil is provided at the center thereof. 13 is a subframe fixed to the sealed container 1 at the bottom of the sealed container 1, 13a is a projecting portion formed so as to surround the main shaft 11 at the center of the subframe, and 13b is a penetration formed in the projecting portion 13a. In this section, the lower end of the main shaft 11 enters the inside thereof.
14 is a ball bearing that is mounted on the through-hole 13b and rotatably supports the lower end of the main shaft 11, and 15 is an oil pump that is mounted on the through-hole 13b at the lower part of the ball bearing and is provided at the lower end of the main shaft 11. A pump casing 16 through which the pump shaft 11a passes, a positive displacement pump 17 that is rotationally driven by the pump shaft 11a, a pump port 18, and a pump cover 19 that fixes the pump casing 16 and the pump port 18 are configured.
[0016]
The pump port 18 is provided with a suction port 18 a and a discharge port 18 b communicating with the through hole 12 of the main shaft 11. 20 is an oil pipe that communicates the oil reservoir 2 with the suction port 18a of the pump port 18, and 21 is an oil supply hole that is provided above the ball bearing 14 so as to open from the through hole 12 of the main shaft 11 in the radial direction of the main shaft 11. 25 is an oil supply pipe fixed to the airtight container 1 so as to penetrate the airtight container 1, 26 is a valve provided at the outer end of the oil supply pipe 25, and 27 is connected to the oil supply pipe 25 via the valve 26. An oil container 28 is an oil level sensor provided in the sealed container 1 at a position above the ball bearing 14, and when the oil level 2a of the oil sump 2 falls below the position of the oil level sensor, a signal is generated to open the valve 26, When the oil level 2a rises from the position of the oil level sensor, another signal is generated to close the valve 26.
[0017]
Since the scroll compressor according to the first embodiment is configured as described above, when the lubricating oil level 2a in the hermetic container 1 falls below the position of the oil level sensor 28, the valve 26 is controlled by a signal from the oil level sensor 28. The lubricating oil is opened and supplied from the oil container 27 storing the lubricating oil to the sealed container 1 through the oil supply pipe 25. When the lubricating oil level 2 a rises from the position of the oil level sensor 28, the valve 26 is closed by another signal from the oil level sensor 28, and the supply of lubricating oil from the oil container 27 is stopped.
Thus, by disposing the oil level sensor 28 above the ball bearing 14, regardless of the presence or absence of the oil supply hole 21 provided in the main shaft 11 for supplying oil to the ball bearing 14, the displacement pump 17 Even when the oil supply capacity is lowered, the ball bearing 14 is always located in the lubricating oil, so that the lubricity of the ball bearing 14 is improved.
[0018]
Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional view of a main part showing the configuration of the second embodiment. In this figure, the same or corresponding parts as in FIG. The difference from FIG. 1 is that the oil container 27 provided outside the sealed container is replaced with an oil separator. That is, in FIG. 2, 29 is an oil separator that is provided on the high-pressure side of a known unit pipe and separates the refrigerant and the lubricating oil, and is communicated with the valve 26.
[0019]
Since the scroll compressor according to the second embodiment is configured as described above, when the lubricating oil level 2a in the hermetic container 1 falls below the position of the oil level sensor 28, the valve 26 is controlled by a signal from the oil level sensor 28. The lubricating oil is opened and supplied to the sealed container 1 through the oil supply pipe 25 from an oil separator 29 provided on the high pressure side of a unit pipe (not shown). When the lubricating oil level 2a rises from the position of the oil level sensor 28, the valve 26 is closed by another signal from the oil level sensor 28, and the supply of the lubricating oil from the oil separator 29 is stopped. Thus, by disposing the oil level sensor 28 above the ball bearing 14, regardless of the presence or absence of the oil supply hole 21 provided in the main shaft 11 for supplying oil to the ball bearing 14, the displacement pump 17 Even when the oil supply capacity is lowered, the ball bearing 14 is always located in the lubricating oil, so that the lubricity of the ball bearing 14 is improved.
[0020]
Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a cross-sectional view of a main part showing the configuration of the third embodiment. In this figure, the same or corresponding parts as in FIG. A difference from FIG. 6 is that a radial oil supply hole 21 provided in the main shaft is provided below the ball bearing 14. That is, in FIG. 3, 21 is an oil supply hole provided below the ball bearing 14 so as to open from the through hole 12 of the main shaft 11 in the radial direction of the main shaft.
[0021]
Since the scroll compressor according to the third embodiment is configured as described above, the lubricating oil pumped up by the positive displacement pump 17 through the oil pipe 20 is sucked into the suction port 18a, the discharge port 18b, and the through hole 12 of the main shaft 11. Then, the oil is discharged out of the main shaft 11 from the oil supply hole 21 of the main shaft. However, since the oil supply hole 21 is located below the ball bearing 14, the discharged lubricating oil is held in the space formed by the protruding portion 13 a of the subframe 13, the pump casing 16, and the ball bearing 14. It circulates from below the ball bearing 14 through the gap between the balls and above the ball bearing 14 as indicated by an arrow. As a result, the circumference of the ball of the ball bearing 14 that is easily worn can be always filled with the lubricating oil, and the lubricity of the ball bearing 14 is improved.
[0022]
Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view of a main part showing the configuration of the fourth embodiment. In this figure, the same or corresponding parts as in FIG. The difference from FIG. 3 is that a bearing cover is provided above the ball bearing. That is, in FIG. 4, reference numeral 30 denotes a bearing cover provided on the upper surface of the projecting portion 13 a formed at the center of the sub-frame 13. The bearing cover 30 is provided so as to cover from the upper side of the ball bearing 14. There are minute gaps between them so that the lubricating oil can flow out above the bearing cover.
[0023]
Since the scroll compressor of the fourth embodiment is configured as described above, the lubricating oil pumped up by the positive displacement pump 17 through the oil pipe 20 is sucked into the suction port 18a, the discharge port 18b, and the through hole 12 of the main shaft 11. After being discharged from the oil supply hole 21 of the main shaft to the outside of the main shaft 11 and held in the space formed by the protruding portion 13a of the subframe 13, the pump casing 16 and the ball bearing 14, from below the ball bearing 14 It flows out of the ball bearing 14 through the gap between the balls as indicated by an arrow, and further flows out and circulates above the bearing cover 30 through a minute gap between the main shaft 11 and the bearing cover 30. By providing the bearing cover 30, the lubricating oil circulated to the ball bearing 14 is not blown off by the refrigerant gas in the hermetic container 1, and the circumference of the ball of the ball bearing that is easily worn is always filled with the lubricating oil. Therefore, lubricity is improved without being affected by the refrigerant gas, and a highly reliable scroll compressor can be obtained.
[0024]
【The invention's effect】
A scroll compressor according to the present invention includes a sealed container having an oil sump formed at the bottom, a scroll-type fluid compression mechanism disposed at the top of the sealed container, and a fluid compression mechanism disposed in the sealed container. A motor having a main shaft to be driven and having a through-hole for supplying lubricating oil in the main shaft, a bearing provided in the vicinity of an oil sump, and rotatably supporting the main shaft, and driven by the main shaft, Since the oil level of the oil sump is positioned above the bearing, the ball bearing is always kept in the oil. As a result, damage to the ball bearing and abnormal wear due to depletion of the lubricating oil can be prevented, and there is no temperature difference between the ball bearing and the raceway, resulting in a decrease in the viscosity of the oil. Therefore, it is possible to obtain a highly reliable scroll compressor.
[0025]
The scroll compressor according to the present invention is also provided in the hermetic container, and is provided in the hermetic container above and below the bearing, and an oil supply pipe that communicates with the outside oil container via the valve. When the oil level in the oil sump is detected and the oil level falls below a predetermined level, an oil level sensor is provided that opens the valve and supplies oil from the oil container into the sealed container. Even if it falls below the ball bearing, this is detected by the oil level sensor, and the oil level rises by opening the valve, so the ball bearing is always kept in the oil, and the ball bearing is damaged or abnormal due to depletion of lubricating oil Wear can be prevented, and a highly reliable scroll compressor can be obtained.
[0026]
Since the scroll compressor according to the present invention uses an external oil container as an oil separator, when the lubricating oil level falls below the oil level sensor, the valve is opened by a signal from the oil level sensor, and the unit piping When the lubricating oil is supplied to the sealed container from the oil separator provided on the high pressure side and the lubricating oil level rises above the oil level sensor, the valve is closed by another signal from the oil level sensor, and the oil from the oil separator Since the supply of lubricating oil is stopped, the ball bearing is always kept in the oil. As a result, damage to the ball bearing and abnormal wear due to depletion of the lubricating oil can be prevented, and an oil container for storing the oil, etc. Without using the oil separator, it is possible to supply oil using a differential pressure by using an oil separator that is present in a normal unit, and a highly reliable scroll compressor can be obtained.
[0027]
The scroll compressor according to the present invention is also provided with a sealed container having an oil sump formed at the bottom, a scroll-type fluid compression mechanism disposed at the top of the sealed container, and a fluid compression mechanism disposed in the sealed container. A motor having a main shaft for driving the mechanism and having a through-hole for supplying lubricating oil in the main shaft, a bearing provided in the vicinity of the oil sump and rotatably supporting the main shaft, and driven by the main shaft, The lubricating oil is supplied to the fluid compression mechanism and the bearing through the through hole, and the lubricating oil supplied to the bearing is circulated from the bottom to the top of the bearing. In addition, the bearing housing portion can be used as an oil sump, and oil is supplied from above the ball bearing in order to supply oil into the sealed space formed by the projecting portion, the pump casing, and the ball bearing. Compared to the above, the rotation of the ball bearing prevents the lubricant from splashing outside the ball bearing and reduces the amount of oil supplied to the ball bearing, and does not cause damage or abnormal wear of the ball bearing. High scroll compressor can be obtained.
[0028]
In the scroll compressor according to the present invention, since the bearing cover is provided above the bearing, the lubricating oil above the ball bearing is scattered outside the ball bearing due to the flow of the refrigerant gas and the rotation of the ball bearing. This prevents the amount of oil supplied to the ball bearing from decreasing, and the ball bearing is always kept in the oil, preventing damage to the ball bearing and abnormal wear due to depletion of lubricating oil. A highly reliable scroll compressor can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing a configuration of a scroll compressor according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view of a main part showing a configuration of a scroll compressor according to Embodiment 2 of the present invention.
FIG. 3 is a cross-sectional view of a main part showing a configuration of a scroll compressor according to Embodiment 3 of the present invention.
FIG. 4 is a cross-sectional view of a main part showing a configuration of a scroll compressor according to Embodiment 4 of the present invention.
FIG. 5 is a cross-sectional view showing a configuration of a conventional scroll compressor.
FIG. 6 is a cross-sectional view showing a detailed configuration of a subframe portion of a conventional scroll compressor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Airtight container, 2 Oil sump, 11 Main shaft, 12 Through-hole, 13 Sub frame, 14 Ball bearing, 15 Oil pump, 16 Pump casing, 17 Positive displacement pump, 18 Pump port, 18a Suction port, 18b Discharge port, 19 Pump Cover, 20 oil pipe, 21 oil supply hole, 25 oil supply pipe, 26 valve, 27 oil container, 28 oil level sensor, 29 oil separator, 30 bearing cover.

Claims (3)

A closed container in which an oil sump is formed at the bottom; a scroll-type fluid compression mechanism disposed at the top of the closed container; a main shaft that is disposed in the sealed container and drives the fluid compression mechanism; A motor provided with a through hole for supplying lubricating oil in the main shaft, a bearing provided in the vicinity of the oil sump for rotatably supporting the main shaft, and driven by the main shaft, the lubricating oil in the oil sump An oil pump for supplying the fluid compression mechanism and the bearing through a through-hole, and lubricating oil supplied to the bearing is circulated upward from below the bearing and above the bearing. A scroll compressor characterized by comprising a bearing cover . 2. The scroll compressor according to claim 1 , wherein the bearing cover is fixed to a projecting portion formed at a center portion of the subframe, and a minute gap is formed between the bearing cover and the main shaft . 3. The scroll compressor according to claim 1, wherein an oil supply hole that opens from a through hole of the main shaft in a radial direction of the main shaft is provided below the bearing.

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