KR20180107215A - Sealed two-stage compressor - Google Patents

Abstract

A bearing body 31a for supporting the rotary shaft 15 at the upper portion of the housing 11 having the oil reservoir O1 therein and a bearing casing 31b for supporting the bearing body 31a to the housing 11 And a scroll compressor (13) disposed above the upper bearing (31) and further compressing the refrigerant (R) discharged from the rotary compressor (12). The scroll casing A suction port FC provided with a suction opening FCa which is provided to suck the refrigerant R and opens downward and a suction port FCa disposed between the suction port FCa and the electric motor 14, A limiting surface 62 provided radially inward from the inner surface of the housing 11 is provided so as to restrict the flow of the refrigerant R into the suction opening FCa.

Description

Sealed two-stage compressor

The present invention relates to a hermetically sealed two-stage compressor.

The present application claims priority based on Japanese Patent Application Publication No. 2016-081000 filed on April 14, 2016, the contents of which are incorporated herein by reference.

BACKGROUND ART [0002] Conventionally, for example, a hermetically sealed two-stage compressor having a low-stage side compression section and a high-stage side compression section, which are used for regulating the freezing air and are hermetically sealed in the housing, are known. An example of such a hermetically sealed two-stage compressor is disclosed in Patent Document 1.

In the sealed two-stage compressor of Patent Document 1, a rotary compressor is disposed as the low-stage side compression section, a scroll compressor is disposed as the high-stage side compression section, the gas supplied into the housing is compressed by the rotary compressor, Compressed and discharged from the housing. In the housing, a sealed two-stage compressor is operated in a state where the low-stage side compression section and the lubricating oil of the high-stage side compression section are held.

Here, in the sealed two-stage compressor of Patent Document 1, bearing brackets are provided at the divided portions of the upper and lower split type housings to avoid the gas in the outer peripheral region inside the housing containing a lot of oil from being introduced into the scroll compressor On the other hand, the gas in the central region having a small oil content flows into the scroll compressor, thereby reducing the oil circulation amount (OC%) in the refrigeration cycle.

Patent Document 1: JP-A-2009-180107

However, when a member for reducing the oil circulation amount (OC%) in the refrigeration cycle is provided on the housing by welding as in the bearing bracket of Patent Document 1, there is a possibility that welding deformation to the housing occurs. Therefore, it is difficult to manufacture a sealed two-stage compressor with good precision, and manufacturing becomes troublesome. Further, since the bearing bracket of the sealed two-stage compressor of Patent Document 1 receives a load from the bearing case, it is necessary to increase the thickness to secure rigidity. As a result, the inner volume of the housing becomes small, which is disadvantageous when oil in the gas is separated.

Accordingly, the present invention provides an enclosed two-stage compressor capable of being easily manufactured and capable of effectively separating the oil in the gas.

A sealed two-stage compressor according to a first aspect of the present invention includes a housing having an oil reservoir therein, a rotating shaft disposed in the housing, a stator disposed radially outward in the housing for rotating the rotating shaft, A low-stage side compression section disposed on one side (first end side) in the axial direction of the rotary shaft with respect to the motor in the housing and connected to the rotary shaft to compress gas, A bearing device having a bearing body disposed on the other side (second end side) in the axial direction with respect to the motor in the housing, the bearing body supporting the rotation shaft, and a bearing casing supporting the bearing body to the housing; (2) disposed on the other side in the axial direction (second end side) with respect to the bearing device, And a high-stage side compression section for further compressing the gas. The bearing casing is provided with a suction flow path provided with a suction opening which is provided to suck gas into the high-stage side compression section and open toward one axial side (first end side) And a restriction surface provided between the suction opening and the motor and arranged radially inwardly from the inner surface of the housing so as to limit the flow of gas to the suction opening at the radially outer side.

In such a sealed two-stage compressor, the gas is compressed together with the oil in the oil storage portion in the low-stage side compression section. As a result, the gas discharged from the low-stage side compression section contains oil. A part of the gas containing oil flows out toward the motor and then flows toward the high-stage side compression section through the gap between the stator and the rotor or the through hole provided in the rotor. When the gas passes through the motor, the oil in the gas contacts the oil separation plate provided on the rotor or the rotor, thereby reducing the oil content in the gas. On the other hand, the gas that has passed between the stator and the housing flows directly toward the high-stage side compression section without contacting the rotor. As a result, the refrigerant flows toward the high-stage side compression section in a state where the oil content in the gas is large. That is, the oil level in the gas discharged from the low-stage side compression portion is small in the radial direction inside the housing and large in the radially outer side.

Here, in this embodiment, the inflow of the gas from the radially outer side into the suction opening can be restricted by a simple method of providing the bearing surface with the limiting surface. As a result, it is possible to restrict the gas having a large amount of oil content in the radially outward direction from being introduced into the suction passage through the suction opening as it is. Further, the gas in the radially inside with a small oil content is introduced into the suction passage through the suction opening Lt; / RTI > As a result, it is possible to supply a gas having a low oil content to the high-stage-side compression section and to reduce the oiliness in the gas compressed and discharged by the high-stage-side compression section. Accordingly, it is possible to reduce the oil circulation amount (OC%) in the system including the sealed two-stage compressor.

Further, when the gas in the radially outward direction comes into contact with the restriction surface, the oil in the gas adheres to the restriction surface, and the gas whose oil content is reduced is guided radially inward by the restriction surface and flows into the suction passage from the suction opening. In this way, the oil level in the gas is reduced by the restriction surface and is supplied from the suction flow path to the high-stage side compression section. Therefore, the oil level in the gas compressed and discharged by the high- stage side compression section can be reduced, It is possible to reduce the amount of water.

A two-stage hermetic compressor according to a second aspect of the present invention is characterized in that it is fixed to the bearing casing of the first aspect and has a plate shape and is provided on one side (first end side) And an inflow limiting plate having an inflow limiting plate.

Since the restriction surface is provided in the bearing casing by providing the inflow limiting plate in the bearing casing in this way, compared with the case where the member corresponding to the inflow limiting plate is provided in the housing to provide the restriction surface, Can be provided in the bearing casing. In addition, a limit surface can be easily provided to an existing bearing casing.

In the sealed type two-stage compressor according to the third aspect of the present invention, the restriction surface in the first or second aspect is provided at an end in the radially outer side which is the inner surface side of the housing, And a truncated conical shape inclined toward one side (first end side) of the axial direction and centering on the axial line as it extends from the plane toward the inner side in the radial direction And may have an inclined surface.

By providing the inclined surface having the truncated cone shape as the limiting surface in this manner, it is possible to form an annular opening around the axial line extending from the suction opening to one side (first end side) in the axial direction. Since the opening extending from the suction opening can be formed in an annular shape as described above, the opening area can be secured, and the oil level of the gas flowing into the suction passage from the housing can be secured. Further, the gas having a large oil content in the radially outer region can flow to the radially inward side along the plane of the restriction surface and collide with the inclined plane, so that oil can be attached to the inclined plane. Therefore, it is possible to reduce the oil content in the gas supplied to the high-stage-side compression section by introducing the gas into the suction passage in a state in which the oil content in the gas is further reduced and to reduce the oiliness in the gas compressed and discharged by the high- Can be reduced. Therefore, it is possible to further reduce the oil circulation amount (OC%) in the system.

In the hermetically sealed two-stage compressor according to the fourth aspect of the present invention, the radially inner side inner peripheral portion of the restriction surface in the first to third aspects is a radially inner side And the restriction surface may occlude a part of the suction opening so as to secure a suction amount of gas required in the high-stage side compression section.

As described above, since the inner edge portion of the limiting surface is located radially inward of the stator, the limiting surface extends to the position of the rotor. Therefore, gas having contact with the rotor and sufficiently reduced in oiliness can be introduced into the suction passage from the suction opening. Therefore, the oil level in the gas compressed and discharged by the high-stage side compression section can be further reduced, and the oil circulation amount (OC%) in the system can be further reduced. In this case, since the suction amount of the required gas can be ensured in the high-stage side compression section, a reduction in the compression efficiency in the high-stage side compression section can be avoided.

The closed type two-stage compressor according to the fifth aspect of the present invention is characterized in that the gap between the outer rim of the radially outer side of the restriction surface and the inner surface of the housing in the first to fourth aspects And may further comprise a seal member provided thereon.

With such a seal member, it is possible to prevent the gas having a large oil content from passing between the housing and the stator from entering the high-stage side compression section directly between the restriction surface and the housing in the radially outer region of the housing. Therefore, the oil level in the gas compressed and discharged by the high-stage side compression section can be further reduced, and the oil circulation amount (OC%) in the system can be further reduced.

In the sealed two-stage compressor according to the sixth aspect of the present invention, in the bearing casing according to any one of the first to fifth aspects, at the position of the radially outer end, the bearing And an oil return portion that allows the oil from the high-stage side compression portion to communicate with the one side (first end side) of the axial direction of the casing may be further provided.

By providing such an oil return portion, the oil used for lubrication in the high-stage side compression portion is returned to the housing through the oil return portion. Therefore, the oil level in the gas compressed and discharged by the high-stage side compression unit can be further reduced, and the oil circulation amount (OC%) in the system can be further reduced.

Further, by providing the oil returning portion at the radially outer end of the bearing casing, the oil returning portion is provided at a position away from the suction opening which opens radially inward. Therefore, the oil returning from the oil returning portion to the housing can be prevented from being directly introduced into the suction passage from the suction opening. Therefore, the oil level in the gas compressed and discharged by the high-stage side compression unit can be further reduced, and the oil circulation amount (OC%) in the system can be further reduced.

In the sealed two-stage compressor according to the seventh aspect of the present invention, the bearing casing according to any one of the first to sixth aspects is provided with a housing portion extending in the axial direction and capable of inserting the motor wiring, And a sealing member provided in a gap between the limiting surface and the wiring of the motor.

With such a seal member, even if the housing portion in which the motor wiring is inserted is formed in the bearing casing, the gap between the restriction surface and the motor wiring can be sealed. Therefore, it is possible to suppress the supply of the gas including oil through the gap to the high-stage side compression section as it is.

According to the hermetic two-stage compressor described above, by using the method of providing the limiting surface to the bearing casing, it is possible to manufacture easily, and the oil in the gas can be effectively separated by the limited surface.

1 is a longitudinal sectional view showing a closed type two-stage compressor according to a first embodiment of the present invention.
Fig. 2 shows a sealed two-stage compressor according to the first embodiment of the present invention, and Fig. 1 is a longitudinal sectional view at another cross-sectional position in the circumferential direction.
Fig. 3 is a view showing a bearing casing and an inflow limiting plate of a closed type two-stage compressor according to a first embodiment of the present invention, and shows a cross section II of Fig.
4 is a longitudinal sectional view showing a closed type two-stage compressor according to a second embodiment of the present invention.
Fig. 5 is a sectional view taken along the line IV-IV of Fig. 4 showing the bearing casing and the inflow limiting plate of the closed type two-stage compressor according to the second embodiment of the present invention.
6 is a view showing a bearing casing and an inflow limiting plate of a closed type two-stage compressor according to a modification of the embodiment of the present invention.

[First Embodiment]

Hereinafter, a closed type two-stage compressor 1 (hereinafter referred to as a two-stage compressor 1) according to a first embodiment of the present invention will be described.

As shown in Figs. 1 and 2, the two-stage compressor 1 compresses a refrigerant R, for example, a gas such as carbon dioxide. The two-stage compressor 1 includes a housing 11, a rotary compressor (low-stage side compression section) 12 provided in the housing 11, a scroll compressor (high-stage side compression section) 13, A rotary shaft 15 and a bearing device 30 and an inflow limiting plate 61 fixed to the bearing device 30. [

The housing 11 has a cylindrical main body portion 21 and an upper lid portion 22 and a lower lid portion 23 for closing upper and lower openings of the main body portion 21. The housing (11) seals the inside space.

The rotary shaft (15) is arranged so as to extend vertically in the housing (11).

The electric motor 14 is disposed on the outer peripheral side of the rotary shaft 15 and rotates the rotary shaft 15 about the axial line X. [ That is, the electric motor 14 has a rotor 38 fixed to the outer peripheral surface of the rotary shaft 15 and a rotor 38 facing the rotor 38 in the radial direction with a clearance between the outer peripheral surface of the rotor 38, And a stator 39 fixed to the inner surface of the main body 21.

The electric motor 14 is connected to a power source (not shown) by a wiring 14a, and rotates the rotary shaft 15 by electric power from the power source. The stator 39 is fixed to the inner surface of the housing 11 in a part of the circumferential direction and the inner surface of the housing 11 and the stator 39 are fixed to the inner surface of the housing 11 in the radial direction With a gap S therebetween.

The rotary compressor 12 is disposed in the housing 11 at a position adjacent to the lower lid portion 23 at one side in the direction of the axis X of the electric motor 14 and below. The rotary compressor 12 includes an eccentric shaft portion 41 provided on the rotary shaft 15 and a piston rotor fixed to the eccentric shaft portion 41 and rotating eccentrically with respect to the axial line X in accordance with the rotation of the rotary shaft 15 And a cylinder 44 in which a compression chamber C1 accommodating the piston rotor 42 is formed.

The cylinder 44 is provided with a suction hole 44a for allowing the refrigerant R to flow therein. A suction pipe 33 provided through the main body 21 of the housing 11 is connected to the suction hole 44a and the refrigerant R is supplied from the outside of the housing 11 through the suction pipe 33. [ A discharge port (not shown) is formed in the cylinder 44 so that the refrigerant R compressed by the rotary compressor 12 is discharged from the discharge hole to the area where the electric motor 14 in the housing 11 is provided .

Oil (A) is stored in the bottom portion of the housing (11), and an oil storage portion (O1) is provided. The liquid level of the oil storage portion O1 at the time of initial sealing of the oil A is located above the rotary compressor 12. [ As a result, the rotary compressor (12) is driven in the oil reservoir (O1).

The scroll compressor (13) is disposed above the electric motor (14) inside the housing (11). The scroll compressor 13 includes a fixed scroll 51 fixed to the upper bearing 31 and a orbiting scroll 57 arranged to face the fixed scroll 51 below the fixed scroll 51.

The fixed scroll (51) has an end plate (52) fixed to the upper surface of the upper bearing (31) and a fixed lap (53) protruding downward from the end plate (52). A discharge hole 52a extending vertically is formed in a central portion (in the vicinity of the axis X) of the end plate 52.

The orbiting scroll 57 is disposed between the bearing device 30 (the upper bearing 31 described later) and the end plate 52 of the fixed scroll 51 so as to be fitted in the direction of the axis X, A fixed end plate 58 and a orbiting wrap 59 protruding upward from the end plate 58. [

The single plate 58 is fixed to the eccentric shaft portion 56 provided at the upper end of the rotary shaft 15 and eccentrically rotates with respect to the axial line X as the rotary shaft 15 rotates.

The orbiting wrap 59 forms a compression chamber C2 for compressing the refrigerant R between the fixed lap 53 and the fixed lap 53 by engaging with the fixed lap 53. [

The fixed scroll 51 is provided with a fixed scroll 51 that is capable of sucking the refrigerant R compressed by the rotary compressor 12 and discharged into the housing 11 into the compression chamber C2 through the bearing device 30 And a suction hole is formed. The refrigerant R compressed in the compression chamber C2 is fixed to the upper portion of the fixed scroll 51 in the housing 11 through the discharge hole 52a of the fixed scroll 51, Is discharged to the outside of the housing (11) from a discharge tube (34) extending outwardly through the housing (11) while being opened in a space surrounded by the discharge cover (50).

The bearing device 30 is provided with an upper bearing 31 provided in the upper portion of the housing 11 and lower bearings 32A and 32B provided in the lower portion of the housing 11.

The lower bearings 32A and 32B rotatably support the rotary shaft 15 at the lower portion of the housing 11 with respect to the housing 11. [ Concretely, the lower bearings 32A and 32B are arranged so as to sandwich the rotary compressor 12 from above and below in the direction of the axis X, and are fixed to the cylinder 44 with bolts 48. [

The upper bearing 31 includes a bearing body 31a for rotatably supporting the rotary shaft 15 about the axis X of the rotary shaft 15 with respect to the housing 11 and a bearing body 31a integrally formed with the bearing body 31a And a bearing casing 31b for supporting the bearing body 31a to the housing 11. [

As shown in Figs. 1 to 3, the bearing casing 31b is provided with a plurality of inhalations (not shown) extending in parallel to the axis X across the entire axial direction X of the bearing casing 31b, (FC) are provided. In the present embodiment, the suction passage FC is a concave groove having a rectangular shape in cross section and recessed inwardly in the radial direction from the outer peripheral surface of the bearing casing 31b.

The bearing casing 31b is extended inwardly in the radial direction from the lower end of the suction passage FC continuously to the lower side which is one side (first end side) of the axial line X. When the bearing casing 31b is viewed, Is provided with a suction opening FCa which opens in a linear shape toward the suction opening FCa.

The bearing casing 31b is provided with a concave portion (accommodating portion) 31c recessed in the entire axial direction X from the outer peripheral surface toward the radially inward side at a position not interfering with the intake opening FCa. A wiring 14a of the electric motor 14 is disposed inside the recess. A seal member 65 is provided in the gap between the concave portion 31c and the wiring 14a and the inner surface of the housing 11. [ The sealing member 65 may be made of a sealing material such as resin.

The bearing casing 31b is provided with a bearing flow passage 31d that opens in the interior of the housing 11 at a position in the axial direction X where the orbiting scroll 57 passes through in the radial direction and is fixed to the eccentric shaft portion 56, (See Fig. 2).

The bearing casing 31b communicates with the bearing flow path 31d at a position where the intake opening FCa and the concave portion 31c do not interfere with each other and at an end portion in the radially outward direction, An oil return pipe (oil return portion) 72 extending through the bearing casing 31b toward the bearing casing 31b and extending along the inner surface of the housing 11 and projecting downward from the bearing casing 31b.

As shown in Fig. 3, the inflow limiting plate 61 is fixed to the bearing casing 31b by bolts 60 from below. The inflow limiting plate 61 has an annular shape with the axis X as the center. The inflow limiting plate 61 has a plurality of notches 63 that are cut out from the radially inward end toward the radially inward side at positions corresponding to the intake openings FCa. The bottom surface of the inflow limiting plate 61 is a limiting surface 62 and the bottom of the cutout portion 63 forms an inner edge portion 62a of the limiting surface 62. [ The inner edge portion 62a has a curved shape formed along the circumferential direction. The inner edge portion 62a is located at the intermediate position in the radial direction of the suction opening FCa so that only the radially inward position of the suction opening FCa is blocked by the inflow limiting plate 61, As shown in Fig. Thereby, the flow of the refrigerant R to the suction opening FCa from the outside in the radial direction by the restriction surface 62 is restricted.

The inflow limiting plate 61 is provided with a cutout 61a recessed radially inwardly from the outer edge portion 62b at a position corresponding to the position of the wiring 14a so as not to interfere with the wiring 14a .

The limiting surface 62 is provided so as to project radially inward from the inner surface of the housing 11 as viewed from the end surface including the axis X as shown in Fig.

The seal member 66 is provided in the gap between the inner surface of the housing 11 and the outer edge portion 62b of the limiting surface 62 (the end edge on the outer side in the radial direction along the inner surface of the housing 11) Respectively. As the seal member 66, a seal member such as a resin or an O-ring can be used.

In the two-stage compressor (1) of the present embodiment described above, the refrigerant (R) is compressed together with the oil (A) in the oil reservoir (O1) in the rotary compressor (12). Therefore, the refrigerant R discharged from the rotary compressor 12 contains the oil A. A part of the refrigerant R containing the oil A flows out toward the electric motor 14 and then flows through the gap between the stator 39 and the rotor 38 or the through hole 37 provided in the rotor 38 To the scroll compressor (13). When the refrigerant R passes through the electric motor 14, the oil A in the refrigerant R flows through the rotor 38 and the oil separation plate 38a provided in the upper portion of the rotor 38 and extending in the radial direction, The content of the oil (A) in the refrigerant (R) is reduced.

On the other hand, the refrigerant R that has passed through the gap S between the stator 39 and the housing 11 flows toward the scroll compressor 13 without contacting the rotor 38. This causes the refrigerant R to flow toward the scroll compressor 13 in a state where the content of the oil A in the refrigerant R is large. That is, the amount of the oil A in the refrigerant R discharged from the rotary compressor 12 is small in the radial direction inside the housing 11 and large in the radially outer side.

Here, in the present embodiment, the inflow limiting plate 61 having the limiting surface 62 is provided in the bearing casing 31b to limit the flow of the refrigerant R from the radially outer side to the suction opening FCa . This makes it possible to restrict the refrigerant R having a large amount of the oil A in the radially outward direction from being introduced directly into the suction passage FC through the suction opening FCa. In addition, it becomes possible to introduce the refrigerant R in the radially inward side, which contains a small amount of the oil A, into the suction passage FC through the suction opening FCa.

As a result, the refrigerant R having a small amount of the oil A can be supplied to the scroll compressor 13, and the amount of the oil A in the refrigerant R compressed and discharged by the scroll compressor 13 can be reduced . It is possible to reduce the oil circulation amount (OC%) in the system including the two-stage compressor (1).

When the refrigerant R in the radially outward side comes into contact with the limiting surface 62, the oil A in the refrigerant R adheres to the limiting surface 62 and the refrigerant R in which the content of the oil A is reduced R is guided radially inward by the limiting surface 62 and flows into the suction passage FC from the suction opening FCa. The amount of the oil A in the refrigerant R is reduced by the limiting surface 62 and supplied to the scroll compressor 13 from the suction flow path FC. The amount of oil A in the refrigerant R compressed by the scroll compressor 13 and discharged from the discharge pipe 34 to the outside of the housing 11 can be reduced and the oil circulation amount OC% Can be reduced.

Further, by providing the inflow limiting plate 61 on the bearing casing 31b, the limiting surface 62 can be provided on the bearing casing 31b. This makes it unnecessary to weld the housing 11 to the housing 11 so that the limiting surface 62 can be easily mounted on the bearing 11, It can be provided in the casing 31b. Therefore, the oil (A) in the refrigerant (R) can be effectively separated from the refrigerant (R) while easily manufacturing the two-stage compressor (1) having the limiting surface (62).

Also, by providing the oil return pipe (72), the oil used for lubrication in the high-stage side compression section is returned into the housing (11) through the oil return pipe (72). Therefore, the amount of the oil A in the refrigerant R compressed and discharged by the scroll compressor 13 can be further reduced. In addition, by providing the oil return pipe 72 at the radially outer end of the bearing casing 31b, the oil return pipe FCa is provided at a position away from the radially inward opening portion of the radially inner suction opening FCa 72 are provided. It is possible to avoid the oil A returning from the oil return pipe 72 to the housing 11 from flowing into the suction passage FC as it is from the suction opening FCa. Therefore, the amount of oil (A) in the refrigerant (R) compressed and discharged by the scroll compressor (13) can be further reduced.

The amount of the oil A that has passed through the gap S between the housing 11 and the stator 39 in the radially outward region of the housing 11 is increased by the seal member 66, It is possible to avoid that the refrigerant gas R flows directly into the scroll compressor 13 from between the limiting surface 62 and the inner surface of the housing 11. [ Therefore, the amount of the oil A in the refrigerant R compressed and discharged by the scroll compressor 13 can be further reduced.

Even if the concave portion 31c through which the wiring 14a of the electric motor 14 is inserted is formed in the bearing casing 31b, the concave portion 31c, the wiring 14a, The gap between the inner surfaces of the housing 11 can be sealed. Therefore, the refrigerant R containing the oil A can be prevented from being directly supplied to the scroll compressor 13 through the gap.

[Second embodiment]

Next, a two-stage compressor 80 according to a second embodiment of the present invention will be described with reference to Figs. 4 and 5. Fig. In Fig. 4, the wiring 14a of the electric motor 14 and the oil return pipe 72 are not shown for convenience of explanation.

The same components as those in the second embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

The two-stage compressor 80 of the present embodiment differs from the inflow limiting plate 61 of the first embodiment in that the inflow limiting plate 81 having the limiting surface 82 is different from the inflow limiting plate 61 of the first embodiment.

The inflow limiting plate 81 includes an annular portion 83 disposed on the outer side in the radial direction along the inner surface of the housing 11 and having a toric shape around the axis X, And a conical portion 84 provided integrally with the annular portion 83 in the radially inward direction.

The lower surface of the annular portion 83 is a flat surface 86 having a toric shape with the axis X as the center. The outer surface of the conical portion 84 is an inclined surface 87 having a truncated cone shape with the axis X as the center. The inclined surface 87 is inclined downward as it extends radially inwardly from the plane 86. As shown in Fig.

As described above, the limiting surface 82 of the present embodiment has the plane 86 and the inclined plane 87. Inner edge portion 87a which is an end edge in the radially inner side of the inclined surface 87 is located radially inward of the stator 39 and radially outward of the bearing casing 31b and the rotary shaft 15.

In the present embodiment, the inner edge portion 87a of the inflow limiting plate 81 is formed so as to secure the suction amount of the refrigerant R required in the scroll compressor 13, that is, to secure the opening area of the suction opening FCa And is disposed at a possible position.

In the two-stage compressor 80 of the present embodiment described above, the limiting surface 82 has the inclined surface 87 so that the axis X extends in the direction of the axis X from the suction opening FCa It is possible to form an opening OP having an annular shape as a center. Therefore, the opening area of the suction opening FCa toward the electric motor 14 can be made larger than that of the first embodiment. The flow rate of the refrigerant R flowing into the suction passage FC from the inside of the housing 11 can be secured.

The refrigerant R having a large content of the oil A in the radially outward region in the housing 11 collides against the inclined surface 87 after flowing radially inward along the plane 86, 87 can also be attached to the oil (A). Therefore, the refrigerant R can be supplied to the scroll compressor 13 while the content of the oil A in the refrigerant R is reduced, and the refrigerant R is introduced into the suction passage FC. As a result, the amount of oil A in the refrigerant R compressed by the scroll compressor 13 and discharged to the outside of the housing 11 can be further reduced, and the amount of oil A in the system including the two- It is possible to further reduce the oil circulation amount (OC%).

In the present embodiment, since the inner edge portion 87a on the inner side in the radial direction of the inclined surface 87 is located radially inward of the stator 39, the limiting surface 82 extends to the position of the rotor 38 do. Therefore, the refrigerant R flowing in the radially inward direction in the housing 11 and the oil A in the refrigerant R are brought into contact with the rotor 38 so that the amount of the oil A in the rotor 38 The refrigerant R sufficiently reduced can be introduced into the suction passage FC from the suction opening FCa.

The inner edge portion 87a of the inflow limiting plate 81 is disposed at a position where the suction amount of the refrigerant R necessary for the scroll compressor 13 can be secured so that the compression efficiency in the scroll compressor 13 is avoided can do.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the respective constitutions and combinations thereof in the embodiments are merely examples, and additions and omissions of constituent elements within the scope of the present invention are omitted. , Substitutions, and other modifications are possible. The present invention is not limited to the embodiments, but is limited only by the claims.

For example, the bearing casing 31b and the inflow limiting plates 61 and 81 may be integrally formed. That is, the limiting surfaces 62 and 82 may be provided directly on the bearing casing 31b.

Also in the first embodiment, the inner edge portion 62a of the limiting surface 62 may be disposed radially inward of the stator 39, as in the second embodiment. In this case, the position of the inner edge portion 62a may be determined so as to secure the suction amount of the refrigerant R required in the scroll compressor 13. [

Instead of the concave portion 31c, a through hole may be formed in the bearing casing 31b so as to extend in the direction of the axis X, and the wiring 14a may be inserted into the through hole.

6, the restriction surface 62A may be provided with an annular recess 90 which is recessed upward and which is annular with the axis X as the center. By this annular concave portion, the refrigerant R on the radially outer side comes into contact with the limiting surface 62A, so that the oil A adhered to the limiting surface 62A flows inward in the radial direction, and the suction opening FCa As shown in Fig. Such an annular recess 90 can be provided in any of the limiting surface 62 of the first embodiment and the limiting surface 82 of the second embodiment.

In the housing 11, the rotary compressor 12 is provided as the compressor at the lower end, and the scroll compressor 13 is provided as the compressor at the higher end. However, the present invention is not limited to this. For example, the scroll compressor 13 may be provided as the compressor on the lower stage side, and the rotary compressor 12 may be used as the compressor on the higher stage side. In addition, the scroll compressor 13 may be provided on both the low-stage side and the high-stage side, or the rotary compressor 12 may be provided on both the low-stage side and the high-stage side. In addition, a compressor other than the scroll compressor 13 and the rotary compressor 12 may be provided.

The restriction surfaces 62 and 82 may also be provided in the two-stage compressor used in the horizontal arrangement so that the axis of the rotary shaft extends in the horizontal direction.

Industrial availability

According to the sealed two-stage compressor, the oil in the gas can be effectively separated while being easily manufactured.

1, 80 sealed two-stage compressor
11 Housing
12 rotary compressor (low-stage compression unit)
13 scroll compressor (high-stage side compression section)
14 Electric motor
14a wiring
15 rotary shaft
21 body portion
22 upper cover portion
23 Lower cover part
30 Bearing device
31 Upper bearing
31a Bearing body
31b Bearing casing
31c concave portion (receiving portion)
31d Bearing Euro
32A, 32B Lower bearing
33 suction pipe
34 Discharge tube
37 through hole
38 rotor
38a oil separation plate
39 stator
41 Eccentric shaft
42 Piston rotor
44 cylinders
44a suction hole
48 volts
50 Discharge cover
51 Fixed scroll
52 veneer
52a discharge hole
53 Fixed Wraps
56 Eccentric shaft
57 Turning scroll
58 veneer
59 Orbit Wrap
60 volts
61 inflow limiting plate
61a
62, 62A limiting surface
62a inner edge
62b,
Section 63
65 seal member
66 seal member
72 Oil return pipe (oil return part)
81 Inflow limiting plate
82 Limited Face
83 annular portion
84 cone section
86 plane
87 slope
87a inner edge
90 ring shaped recess
C1 compression chamber
C2 compression chamber
O1 oil reservoir
R refrigerant
X axis
A oil
S clearance
FC inhalation flow
FCa suction opening
OP opening

Claims (6)

A housing having an oil reservoir therein,
A rotating shaft disposed in the housing,
A motor disposed in the housing and having a stator provided on an outer side in the radial direction for rotating the rotary shaft and a rotor provided on an inner side in the radial direction,
A low-stage side compression section disposed on one side in the axial direction of the rotary shaft with respect to the motor in the housing and connected to the rotary shaft to compress gas,
A bearing device disposed on the other side in the axial direction with respect to the motor in the housing, the bearing device having a bearing body for supporting the rotary shaft, and a bearing casing for supporting the bearing body to the housing;
And a high-stage side compression section that is disposed on the other side in the axial direction with respect to the bearing device and further compresses the gas discharged from the low-stage side compression section,
In the bearing casing,
A suction passage provided with a suction opening which is provided to suck gas into the high-stage side compression section and open toward one side in the axial direction,
A restriction surface provided between said suction opening and said motor and radially inward from said inner surface of said housing so as to limit the flow of gas from said suction opening to said radially outer side,
Wherein the restriction surface has a plurality of notches cut out from a radially inward end to a radially inward position at a position corresponding to the suction opening so that only a radially inward position of the suction opening opens toward the motor A sealed two-stage compressor. The method according to claim 1,
Further comprising an inflow limiting plate having a plate-like shape fixed to the bearing casing and having the limiting surface on one side of the axial line. The method according to claim 1 or 2,
Preferably,
A plane which is provided at an end portion of the outer side in the radial direction which is to be the inner surface side of the housing and which has an annular shape orthogonal to the axial line,
And an inclined surface which is inclined toward one side in the axial direction and has a truncated cone shape centering on the axial line from the plane toward the radially inward side. The method according to any one of claims 1 to 3,
The inner edge portion in the radially inner side of the limiting surface is disposed at a position radially inward of the stator,
The sealed two-stage compressor according to claim 1, wherein the restriction surface closes a part of the suction opening so as to secure a suction amount of gas required in the high-stage side compression section. The method according to any one of claims 1 to 4,
Further comprising a sealing member provided in a gap between an outer edge of the limiting surface in the radially outer side and an inner surface of the housing. The method according to any one of claims 1 to 5,
Wherein the bearing casing is provided with an oil return portion communicating with the high-stage side compression portion and one side in the axial direction of the bearing casing in the housing at a radially outer end position, Additional sealed two-stage compressor.

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