JP4863816B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to a swing type hermetic compressor.

Conventionally, in a swing-type hermetic compressor as described in Patent Document 1, a swing piston is housed in a cylinder, and a blade of the swing piston is supported by a bush so as to be swingable. In such a hermetic compressor, the bush generates chattering in the radial direction due to the pressure in the cylinder and the back pressure of the bush, and the inner surface of the bush hole of the cylinder may be worn. Therefore, in this hermetic compressor, a groove is formed in the bush, and oil stored in the casing is guided in the groove using the differential pressure between the high pressure in the casing and the pressure in the bush hole to prevent chattering. ing.
JP 2003-172279 A

  However, in the hermetic compressor described in Patent Document 1, oil is likely to rise from the compressor to the system and stored in the casing under conditions where the pressure change and the rotation speed change are severe, such as when starting up the product or during defrost operation. If the oil level of the oil is lower than the height of the communication hole for bush supply in the cylinder, there is a problem that the bush may not be supplied with oil. Further, in a system with a long refrigerant pipe or a system with a large difference in height of the refrigerant pipe, the oil that has risen from the compressor to the system is difficult to return, so there is a problem that the oil level may be lowered and the bushing may not be refueled. Therefore, the height of the oil surface is adjusted to be higher than the height of the communication hole by adjusting the rotation speed of the compressor and the opening of the expansion valve or increasing the amount of oil filling. However, this causes problems such as the rise characteristics of the product being impaired and the size of the compressor being increased.

  An object of the present invention is to provide a hermetic compressor capable of stably supplying oil to a bush.

The hermetic compressor of the first invention includes a plurality of oscillating pistons, bushes, a plurality of cylinders, a middle plate, a casing, and an oil pickup unit. The plurality of oscillating pistons have a blade. The bush supports the blade in a swingable manner. The plurality of cylinders have a cylinder chamber that houses the swing piston, and a bush hole into which the bush is rotatably inserted. The middle plate is disposed between two adjacent cylinders, and has an oil supply communication hole that branches into and communicates with the respective bush holes of the two adjacent cylinders. The casing houses the cylinder and the middle plate , and has an oil storage space (18) for storing oil in the lower part of the cylinder. The oil pickup section has a flow path that directly communicates from the oil storage space to an oil supply communication hole formed in the middle plate . The oil pickup section has a flow path extending into the oil storage space (18).

Here, having a flow passage communicating with the sheet Aburaren hole, since the flow path is provided with an oil pickup portion extending into the interior of the oil storage space, it is possible to stably lubrication Bush. Further, here, even a hermetic compressor including a plurality of cylinders can stably supply oil to each bush.

  The hermetic compressor of the second invention is the hermetic compressor of the first invention, and the inlet of the flow path of the oil pickup section is disposed below the oil level of the oil stored in the oil storage space.

  Here, since the inlet of the flow path of the oil pickup section is disposed below the oil level of the oil stored in the oil storage space, the oil inside the oil storage space is stably and reliably supplied to the bush through the oil pickup section. Is possible.

The hermetic compressor of the third invention is the hermetic compressor of the first invention or the second invention, and uses the differential pressure between the internal pressure of the casing and the internal pressure of the bush hole to pass through the flow path and the oil supply communication hole. Add oil to the bush hole.

Here, a system is adopted in which oil is supplied to the bush hole using a differential pressure between the internal pressure of the casing and the internal pressure of the bush hole .

  A hermetic compressor according to a fourth aspect of the present invention is the hermetic compressor according to any of the first to third aspects of the present invention, and is used for compressing a CO2 refrigerant.

  Here, since the hermetic compressor compresses the CO 2 refrigerant, it is safer than other refrigerants. Further, the compressor can be miniaturized.

According to the 1st or 3rd invention, even if an oil level falls, it can supply to a bush stably, and can utilize a compressor filling oil amount effectively .

  According to the 2nd invention, oil can be stably and reliably supplied to a bush.

  According to the fourth invention, the CO2 refrigerant has a small global warming potential and can realize an environmentally friendly product. In addition, the CO2 refrigerant has a high refrigeration capacity per unit volume, and the cylinder for obtaining the same capacity as other refrigerants can be downsized, and the compressor can be downsized.

[First Embodiment]
<Overall configuration of hermetic compressor 1>
A hermetic compressor 1 using a CO 2 refrigerant shown in FIG. 1 includes a casing 2, a motor 3, a compression mechanism 4, an accumulator 5, a shaft 6, and an oil pickup unit 19. The motor 3, the compression mechanism 4 and the shaft 6 are accommodated in the casing 2. The compression mechanism 4 is a single-cylinder swing compressor, and includes a swinging piston 11, a bush 13, and a cylinder 17 which will be described later.

  The casing 2 has a cylindrical portion 2a and a pair of end plates 2b and 2c that close upper and lower opening ends of the cylindrical portion 2a. The cylindrical portion 2 a of the casing 2 houses the motor stator 8 and the motor rotor 9 of the motor 3. Further, the casing 2 has an oil storage space 18 in which oil A is stored in the lower part of the cylinder 17. Oil A is used for lubrication of the compression mechanism 4 (particularly lubrication of the bush 13) and is filled in the casing 2 together with the CO2 refrigerant. The internal pressure of the casing 2 filled with the CO2 refrigerant is high (about 14 MPa).

  The motor 3 includes an annular motor stator 8 and a motor rotor 9 that is rotatably disposed in an internal space 8 a of the motor stator 8. The motor rotor 9 is connected to the shaft 6 and can rotate with the shaft 6.

  The motor stator 8 is fixed to the cylindrical portion 2a by a plurality of point joints 7. Specifically, the point joining portion 7 is formed by forming a through hole 10a in the cylindrical portion 2a and spot welding the motor stator 8 through the through hole 10a.

<Configuration of compression mechanism 4>
As shown in FIGS. 1 and 2, the compression mechanism 4 includes a swing piston 11 having a blade 12, a bush 13 that supports the blade 12 so as to be swingable, and a cylinder 17. The cylinder 17 has a cylinder chamber 14 that houses the swing piston 11, a bush hole 15 into which the bush 13 is rotatably inserted, and an oil supply communication hole 16 that communicates with the bush hole 15. The oil A is supplied from below the bush 13 inside the bush hole 15 through the oil supply communication hole 16.

  The oscillating piston 11 receives the rotational driving force of the motor 3, and the eccentric portion 6 a of the shaft 6 rotates eccentrically, thereby oscillating inside the cylinder chamber 14, and thereby the CO 2 sucked from the suction pipe 28. The refrigerant is compressed inside the cylinder chamber 14. The compressed CO 2 refrigerant rises through the inside of the casing 2 and is discharged from the discharge pipe 29.

  The cylinder 17 has a lower block 17a and an upper block 17b. The cylinder 17 is screwed to the mounting plate 30. The mounting plate 30 is fixed to the cylindrical portion 2 a of the casing 2 by a mounting plate joint portion 31. The mounting plate joint 31 is formed by spot welding.

<Configuration of oil pickup unit 19>
The oil pickup unit 19 is a communication pipe having a flow path 19a through which oil A flows. The oil pickup unit 19 is fixed to the lower surface of the lower block 17 a of the cylinder 17. The flow path 19 a communicates with the inlet 16 a of the oil supply communication hole 16 of the lower block 17 a of the cylinder 17. Therefore, the flow path 19 a communicates with the oil supply communication hole 16 and further communicates with the bush hole 15 through the oil supply communication hole 16.

  The flow path 19a extends into the oil storage space 18 in which the oil A is stored. Thereby, the oil A inside the oil storage space 18 can be stably supplied to the bush 13 through the flow path 19a of the oil pickup unit 19. The oil A can flow from the oil storage space 18 to the bush hole 15 through the flow path 19 a and the oil supply communication hole 16 by utilizing the differential pressure between the internal pressure of the high-pressure casing 2 and the internal pressure of the bush hole 15.

  Since the inlet 19b of the flow path 19a of the oil pickup unit 19 is disposed below the oil level S of the oil A stored in the oil storage space 18, the height of the lower block 17a of the cylinder 17 is higher than the oil level S. Even at a considerably high position, the oil A inside the oil storage space 18 can be stably and reliably supplied to the bush 13 through the oil pickup portion 19.

<Features of First Embodiment>
(1)
Since the hermetic compressor 1 of the first embodiment has a flow path 19a that communicates with the oil supply communication hole 16 of the cylinder 17, and the flow path 19a includes an oil pickup portion 19 that extends into the oil storage space 18. It is possible to supply oil to the bush 13 stably.

  Therefore, the oil A in the oil storage space 18 can be effectively used for lubricating the bush 13. Therefore, it is possible to realize highly reliable bush lubrication without increasing the size of the compressor and without impairing the rising characteristics of the compressor.

(2)
In the hermetic compressor 1 of the first embodiment, the inlet 19b of the flow path 19a of the oil pickup unit 19 is disposed below the oil level S of the oil A stored in the oil storage space 18, and therefore the oil level S There is no possibility that the inlet 19b of the flow path 19a is above the oil level S even if the height of the oil fluctuates greatly. Accordingly, the oil A inside the oil storage space 18 can be stably and reliably supplied to the bush 13 through the oil pickup portion 19.

(3)
In the hermetic compressor 1 according to the first embodiment, the CO2 refrigerant has a small global warming potential and can realize an environmentally friendly product. In addition, the CO2 refrigerant has a high refrigeration capacity per unit volume, and the cylinder for obtaining the same capacity as other refrigerants can be downsized, and the compressor can be downsized.

<Modification of First Embodiment>
(A)
In the first embodiment, the oil pickup unit 19 is separate from the lower block 17a of the cylinder 17 and is fixed to the lower surface of the lower block 17a. However, the present invention is not limited to this. As a modification of the first embodiment, as shown in FIG. 3, the oil pickup portion 21 may be integrally formed with the cylinder 17.

  The flow path 21 a of the oil pickup unit 21 shown in FIG. 3 communicates with the inlet 16 a of the oil supply communication hole 16 of the lower block 17 a of the cylinder 17. The flow path 21a extends into the oil storage space 18 in which the oil A is stored.

  In this modification, the oil pickup portion 21 is integrally formed with the lower block 17a of the cylinder 17 by a molding method such as casting or injection molding, so that the number of parts can be reduced. Further, since there is no seam between the cylinder 17 and the oil pickup part 21, oil leakage from the seam is also eliminated.

[Second Embodiment]
In the first embodiment, the single-cylinder swing compressor has been described as an example of the compression mechanism 4. However, the present invention is not limited to this, and a hermetic compressor including a plurality of cylinders. The oil pickup part of the present invention can be provided.

  That is, the hermetic compressor according to the second embodiment includes two cylinders 35 and 36 inside the casing 2 as shown in FIGS. 4 to 6, and a middle plate 40 between the two cylinders 35 and 36. It has. The middle plate 40 is formed with an oil supply communication hole 40a that communicates with the bush holes 15 of the two adjacent cylinders 35 and 36 via the branch holes 40b. The oil supply communication hole 40 a of the middle plate 40 communicates with the flow path 41 a of the oil pickup unit 41. The flow path 41a extends into the oil storage space 18 in which the oil A is stored.

  As shown in FIG. 6, the upper end portion 41 b of the oil pickup portion 41 is partially bent and connected to the oil supply communication hole 40 a from the side surface of the middle plate 40.

  Other configurations are the same as the configuration of the hermetic compressor 1 of the first embodiment, and in FIG. 4, components having the same reference numerals as those shown in FIG. Identical to the component.

<Features of Second Embodiment>
In the second embodiment, the hermetic compressor further includes a middle plate 40 between two adjacent cylinders 35 and 36, and the middle plate 40 has respective bush holes 15 of the two adjacent cylinders. An oil supply communication hole 40 a that communicates with each other via the branch hole 40 b is formed, and the oil supply communication hole 40 a of the middle plate 40 communicates with the flow path 41 a of the oil pickup portion 41. Therefore, even in a hermetic compressor including a plurality of cylinders, it is possible to stably supply oil to each bush 13 as in the first embodiment. Therefore, the oil A in the oil storage space 18 can be effectively used for lubrication of the respective bushes 13. Therefore, it is possible to achieve highly reliable bushing without increasing the size of the compressor and without impairing the startup characteristics of the compressor.

<Modification of Second Embodiment>
(A)
In the second embodiment shown in FIGS. 4 to 6, the upper end portion 41 b of the oil pickup portion 41 is partially bent and connected to the oil supply communication hole 40 a from the side surface of the middle plate 40. It is not limited to this.

  As a modification of the second embodiment, as shown in FIGS. 7 to 9, the oil pickup portion 41 may be inserted in the axial direction from the lower surface of the middle plate 40. In this case, a straight pipe can be used as the oil pickup unit 41, and the oil pickup unit 41 can be easily processed. Here, as shown in FIG. 9, the open end of the oil supply communication hole 40 a on the side surface of the middle plate 40 is closed by a stopper 42.

  Also in this modified example, as shown in FIGS. 7 to 9, the middle plate 40 is formed with an oil supply communication hole 40a that communicates with the bush holes 15 of the two adjacent cylinders via the branch holes 40b. The oil supply communication hole 40a of the middle plate 40 communicates with the flow path 41a of the straight tubular oil pickup section 41. Therefore, even in a hermetic compressor including a plurality of cylinders, it is possible to stably supply oil to each bush 13 as in the first embodiment.

(B)
As another modification of the second embodiment, as shown in FIGS. 10 to 12, the oil pickup portion 41 may be inserted in the axial direction from the lower surface of the lower cylinder 35. In this case, a straight pipe can be used as the oil pickup unit 41, and the oil pickup unit 41 can be easily processed.

  In the case of this modification, as shown in FIGS. 10 to 12, the middle plate 40 is formed with an oil supply communication hole 40 c that communicates with the bush holes 15 of two adjacent cylinders. The oil supply communication hole 40c of the middle plate 40 communicates with the flow path 41a of the straight tubular oil pickup section 41 through the bush hole 15 of the lower cylinder 35. Thus, the oil A supplied through the flow path 41a can flow in the order of the bush hole 15 of the lower cylinder 35, the oil supply communication hole 40c, and the bush hole 15 of the upper cylinder 36. Therefore, even in a hermetic compressor including a plurality of cylinders, it is possible to stably supply oil to each bush 13 as in the first embodiment.

  The present invention can be widely applied to a hermetic compressor that requires oil supply to a bush that supports a swingable piston blade in a swingable manner.

1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. The horizontal sectional view of the compression mechanism of FIG. The longitudinal cross-sectional view of the hermetic compressor concerning the modification of 1st Embodiment of this invention. The longitudinal cross-sectional view of the oil pick-up part vicinity of the hermetic compressor concerning 2nd Embodiment of this invention. The figure which looked at the lower side rocking piston of Drawing 4, and its peripheral part from the bottom. Sectional drawing of the oil supply communication hole vicinity of the middle plate of FIG. The longitudinal cross-sectional view of the oil pick-up part vicinity of the hermetic compressor concerning the modification of 2nd Embodiment of this invention. The figure which looked at the rocking | piston piston of the lower side of FIG. 7, and its peripheral part from the bottom. Sectional drawing of the oil supply communication hole vicinity of the middle plate of FIG. The longitudinal cross-sectional view of the oil pick-up part vicinity of the hermetic type compressor concerning the other modification of 2nd Embodiment of this invention. The figure which looked at the lower side rocking piston of Drawing 10, and its peripheral part from the bottom. FIG. 11 is a cross-sectional view of the vicinity of an oil supply communication hole of the middle plate of FIG. 10.

DESCRIPTION OF SYMBOLS 1 Sealing type compressor 2 Casing 3 Motor 4 Compression mechanism 11 Swing piston 12 Blade 13 Bush 15 Cylinder hole 17, 35, 36 Cylinder 18 Oil storage space 19, 21, 41 Oil pick-up part

Claims (4)

A plurality of oscillating pistons (11) having blades (12);
A bush (13) for swingably supporting the blade (12);
A plurality of cylinders ( 35, 36 ) having a cylinder chamber (14) that houses the swing piston (11), and a bush hole (15) into which the bush (13) is rotatably inserted;
An oil supply communication hole that is disposed between two adjacent cylinders (35, 36) and branches into and communicates with each of the bush holes (15) of the two adjacent cylinders (35, 36). A middle plate (40) having (40a, 40b);
A casing (2) that houses the cylinder ( 35, 36 ) and the middle plate (40) and has an oil storage space (18) for storing oil in a lower portion of the cylinder ( 35, 36 );
The oil supply communication hole (40a) formed in the middle plate (40) has flow paths ( 41a, 41b ) communicating directly from the oil storage space (18 ), and the flow path ( 41a ) is the oil storage space ( 18) an oil pickup portion ( 41 ) extending inside ,
A hermetic compressor (1) comprising: The inlets of the flow paths ( 41a, 41b ) of the oil pickup section ( 41 ) are disposed below the oil level of the oil stored in the oil storage space (18).
The hermetic compressor (1) according to claim 1. Using the pressure difference between the internal pressure of the casing (2) and the internal pressure of the bush hole (15), the bush hole (15) is passed through the flow path (41a, 41b) and the oil supply communication hole (40a, 40b). )
The hermetic compressor (1) according to claim 1 or 2. Used to compress CO ₂ refrigerant,
The hermetic compressor (1) according to any one of claims 1 to 3.

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