JP4974970B2 - Sealed electric compressor and refrigerator-freezer - Google Patents

Description

  The present invention relates to a hermetic electric compressor used for a freezing / refrigeration apparatus and a refrigerator-freezer provided with the compressor.

  Many configurations of a lubrication system that supplies oil stored in a casing to a rotating sliding portion in a compressor using a rotating shaft have been proposed. As a recent trend, in order to meet the demand for energy saving, attempts have been made to reduce the sliding loss by setting the shaft diameter of the rotating shaft small. However, if the shaft diameter of the rotating shaft is reduced, the centrifugal force for pumping up the oil is reduced, which causes a problem that the required head of oil and the amount of oil are reduced.

  This problem becomes even more problematic from the viewpoint of heat generation of the rotating sliding portion and cooling of the oil itself when low viscosity oil is employed to obtain a low input. In order to solve this problem, Patent Document 1 discloses a hermetic compressor in which a partition piece called a divider is provided in an oil supply pump.

JP 2000-87856 A (Claim 2, FIG. 4)

In the configuration shown in Patent Document 1 as described above, for example, in order to further save energy in winter when the outside air temperature is low, when the number of rotations of the compressor is further reduced, the amount of oil supply is insufficient, and the rotation shaft There was a problem that the compression performance deteriorated due to seizing or insufficient oil film formation on the compression cylinder.
The present invention has been made to remedy such problems. Even if a low-loss, relatively small-diameter shaft and a low-viscosity oil are used for the purpose of energy saving, a more sufficient lift and oil amount can be obtained. It is an object of the present invention to provide a hermetic electric compressor having an oil supply system that can obtain the above and a refrigerator-freezer equipped with the compressor.

The hermetic electric compressor according to the present invention is rotatably supported by a block provided with a compression mechanism in an airtight container, an electric motor disposed at a lower portion of the block, and a bearing provided in the block. A rotary shaft that is driven to rotate by an electric motor and performs a compression operation of the compression mechanism, and the lower end of the rotary shaft is inclined outward so that the upper end reaches below the bearing and from below to above. And a partition portion that has a concavo-convex shape that forms a groove in a direction substantially along the inclination axis of the inclined passage and extends substantially along the inclination axis of the inclined passage. A piece is provided.
Moreover, the refrigerator-freezer in the present invention is a sealed type provided with a partition piece that has an uneven shape that forms a groove in a direction substantially along the inclination axis of the inclined passage and extends substantially along the inclination axis of the inclined passage. An electric compressor is provided.

According to the present invention, a low-loss relatively small-diameter shaft for energy saving and a low-viscosity oil can be used to constitute an oil supply system capable of obtaining a sufficient lift and an oil amount, which can be rotated at a lower speed. A hermetic electric compressor that can be operated with a number can be obtained.
Moreover, according to this invention, the refrigerator-freezer with little power consumption provided with the hermetic type electric compressor which can be drive | operated by low speed rotation speed can be obtained.

Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings.
1 is a cross-sectional view of a hermetic electric compressor according to a first embodiment of the present invention. A compressor unit 6 in which an electric motor 3 and a compression mechanism 4 are integrated in a block 5 is housed in an upper and lower sealed container 2 to constitute a hermetic electric compressor 1. A rotary shaft 7 that is rotationally driven by the electric motor 3 and performs the compression operation of the compression mechanism 4 is pivotally supported by a bearing portion 8 of the block 5, and a large end portion of a connecting rod 10 is connected to an eccentric shaft 9 at the upper end. A piston 13 that slides in the cylinder 12 by a piston pin 11 is connected to the small end. A valve plate 14 having a suction hole, a suction valve, a discharge hole, and a discharge valve (all not shown) is mounted between one end of the cylinder 12 and the cylinder head 15. The cylinder head 15 includes a suction chamber and a discharge chamber inside, and one end communicates with the suction muffler 16.

Below the rotary shaft 7, an oil supply inclined passage 19 is formed so that the upper end reaches the lower side of the bearing 8 and is inclined outward from the lower side to the upper side. A partition piece made up of a plate-like divider 26b having a concavo-convex shape that forms a groove in a direction substantially along the tilt axis is inserted and locked, and a lower region (broken-line frame surrounding region) of the rotating shaft 7 is an oil pump. It functions as the unit 17. As shown in the perspective view of FIG. 2, in the divider 26b, the groove 261 has a triangular cross section. Further, the upper end of the inclined passage 19 is disposed so as to reach below the bearing 8 and to approach the outer peripheral surface of the rotary shaft 7. A spiral groove 20 is formed on the outer peripheral surface of the rotary shaft 7, and the lower end of the spiral groove 20 communicates with the inclined passage 19 through the lower lateral hole 21. The upper end of the spiral groove 20 communicates with the eccentric passage 23 in the eccentric shaft 9 through the upper horizontal hole 24. As shown in detail in the cross-sectional view of the main part of FIG. 3, the gas vent passage 25 is formed to open on the outer peripheral surface in the direction opposite to the inclination of the inclined passage 19. A perforated plate 29 having a hole 291 in the center is provided at the bottom of the rotating shaft 7, and the rotating shaft bottom is immersed in oil 30 stored in the bottom of the sealed container 2.
In the above configuration, the upper end of the spiral groove 20 communicates with the eccentric passage 23 via the upper horizontal hole 24. However, depending on the configuration, the spiral groove 20 may communicate directly with the eccentric passage 23 without passing through the upper lateral hole 24. Is possible.

Next, the movement of oil will be described with reference to FIG. FIG. 4 (a) shows the oil movement when the flat plate divider 26a disclosed in the prior art is used, and FIG. 4 (b) shows the case where the divider 26b according to Embodiment 1 of the present invention is used. Shows the movement of oil.
Due to the rotation of the rotary shaft 7, the oil 30 rises in the oil supply pump portion 17 over the entire inner peripheral wall of the inclined passage 19. At this time, when the divider 26a disclosed in the prior art is used, the surface that imparts centrifugal force to the oil is only the inner surface of the inclined passage 19, but the divider 26b according to Embodiment 1 of the present invention is used. Since the wall surface which gives centrifugal force to oil increases substantially by the groove | channel 261 formed in the divider 26b, the pressure which pushes up oil increases compared with the conventional structure, and the amount of oil supply increases.

4 (a) and 4 (b), the upward arrow schematically represents the magnitude of the push-up pressure. When the divider 26b according to Embodiment 1 of the present invention is used, the upward arrow is formed on the divider 26b. Since the centrifugal force is applied to each groove, the pressure that finally pushes up the oil generated on the inner surface of the inclined passage 19 is the sum of the pressures generated in each groove. Therefore, the divider 26a disclosed in the prior art is used. It will be bigger than if it were.
FIG. 5 is a result of an experiment conducted by the present inventors. In the case of using a plate-shaped divider having a conventional structure disclosed in the prior art using a rotating shaft having the same diameter, and according to the present invention. It is the data obtained by carrying out comparative measurement of the amount of oil supply of a rotating shaft at the time of using a divider. As can be seen from FIG. 5, the amount using the divider of the present invention is larger.

  According to the first embodiment, a block 5 having a compression mechanism 4, an electric motor 3 disposed at the lower part of the block 5, and a bearing 8 provided in the block 5 are rotatable in the sealed container 2. A rotating shaft 7 supported on the rotating shaft 7 is provided. Above the bearing 8 of the rotating shaft 7, an eccentric shaft 9 for engaging a connecting rod 10 for operating a piston 13 in a cylinder 12 is provided. In the lower part, an oil supply inclined passage 19 is formed so that the upper end reaches the lower part of the bearing 8 and is inclined outward from the lower part to the upper part. A partition piece made up of a plate-shaped divider 26b having a concavo-convex shape forming a groove in a generally extending direction is inserted and locked, and a spiral groove 20 is formed on the outer peripheral surface of the rotating shaft 7 located on the inner surface of the bearing 8. Formed, The lower end of the spiral groove 20 communicates with a lower horizontal hole passage 21 intersecting the inclined passage 19, and the upper end of the spiral groove 20 is directly connected to an eccentric passage 23 provided on the eccentric shaft 9 or via an upper horizontal hole passage 24. Because it is connected, an oil supply system that can obtain a sufficient lift and oil quantity even with a low-viscosity shaft with low loss for energy saving can be configured, and it can rotate at a lower speed. A hermetic electric compressor that can be operated with a number can be obtained.

Embodiment 2. FIG.
In the description of the first embodiment, the groove cross-sectional shape of the divider 26b is triangular. However, the shape is not limited to the triangular shape, and the groove cross-sectional shape of the divider 26c is rectangular as shown in FIG. The same effect can be obtained.

Embodiment 3 FIG.
FIG. 7 shows another embodiment in which the groove 26d of the divider 26d is bent into a sine wave shape.
Thus, even if the groove cross-sectional shape of the divider 26d is configured in a sine wave shape, the same effect as in the first embodiment can be obtained.
As described above, if the divider forms a groove shape along the direction of the inclined axis of the inclined passage 19, centrifugal force is applied to each groove formed in the divider. The pressure that pushes up the oil generated in the cylinder is larger than that in the case of using the flat plate-like divider 26a, and there is an effect that the amount of oil supply is increased.

Embodiment 4 FIG.
FIG. 8 shows an example in which notch portions 262 are provided at the upper and lower ends of the divider having a triangular groove cross-sectional shape. With such a configuration, even when the lower end portion of the divider is slightly deviated from the center of the perforated plate 29, it is possible to reduce the bias of the oil rise through the notch portion 262 of the divider 26e.
In the embodiment shown in FIG. 8, the notch portions 262 are provided at the upper and lower ends of the divider 26e.

  As described above, in Embodiments 1 to 4 according to the present invention, even if a low-loss oil having a relatively small diameter and a low loss is used for energy saving, a further sufficient lift and oil amount can be obtained. The closed type electric compressor that can be operated at a lower rotational speed has been described, but by using a refrigerator-freezer equipped with such an enclosed electric compressor, it can be operated at a lower rotational speed. It is possible to obtain a refrigerator-freezer with a low power consumption provided with a hermetic electric compressor.

It is sectional drawing which shows the hermetic type electric compressor of Embodiment 1 of this invention. It is a perspective view which shows the shape of the divider used for the airtight electric compressor of Embodiment 1 of this invention. It is an expanded sectional view which shows the principal part of the hermetic type electric compressor of Embodiment 1 of this invention. It is explanatory drawing which represented the magnitude | size of the pushing-up pressure of oil typically, Fig.4 (a) is explanatory drawing at the time of using the divider shown to a prior art (patent document 1), FIG.4 (b) is this invention. It is explanatory drawing at the time of using the divider which concerns on. It is a figure explaining the difference in the amount of oil supply at the time of using the divider shown to a prior art (patent documents 1), and the divider concerning the present invention. It is a perspective view which shows the shape of the divider used for the hermetic electric compressor of Embodiment 2 of this invention. It is a perspective view which shows the shape of the divider used for the hermetic electric compressor of Embodiment 3 of this invention. It is a front view which shows the shape of the divider used for the hermetic electric compressor of Embodiment 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Sealing type electric compressor, 2 Upper and lower sealed containers, 3 Electric motor, 4 Compression mechanism, 5 Block, 6 Compressor unit, 7 Rotating shaft, 8 Bearing part, 9 Eccentric shaft, 10 Connecting rod, 11 Piston pin, 12 Cylinder , 13 Piston, 14 Valve plate, 15 Cylinder head, 16 Suction muffler, 17 Oil supply pump part, 19 Inclined passage, 20 Spiral groove, 21 Lower lateral hole, 23 Eccentric passage, 24 Upper lateral hole, 25 Degassing passage, 26a Conventional 26b, 26c, 26d, 26e Divider according to the present invention, 261 groove, 29 perforated plate provided at the bottom of the rotating shaft, 30 oil.

Claims (6)

  A block provided with a compression mechanism in an airtight container, an electric motor disposed at the lower part of the block, and a bearing provided in the block are rotatably supported by the electric motor and driven by the electric motor. A rotary shaft that performs a compression operation, and a lower portion of the rotary shaft is formed with an oil supply inclined passage that is inclined outwardly from the lower side to the upper side so that an upper end reaches the lower side of the bearing, and A sealed type characterized in that the lower part of the inclined passage is provided with a partitioning piece having a concave and convex shape forming a groove in a direction substantially along the inclination axis of the inclined passage and extending substantially along the inclination axis of the inclined passage. Electric compressor.   The hermetic electric compressor according to claim 1, wherein the partition piece has a triangular cross-sectional shape.   The hermetic electric compressor according to claim 1, wherein the partition piece has a rectangular cross-sectional shape.   The hermetic electric compressor according to claim 1, wherein a groove cross-sectional shape of the partition piece is a sine wave shape.   The hermetic electric compressor according to claim 1, wherein a notch is formed at a lower end of the partition piece.   A refrigerator-freezer comprising the hermetic electric compressor according to claim 1.

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