US20170058900A1

Movatterモバイル変換

Info

Publication number: US20170058900A1
Application number: US15/232,162
Authority: US
Inventors: In-Won PARK; Hyun-Jin Kim; Je-Hyeon Moon
Original assignee: Hyundai Mobis Co Ltd
Current assignee: Hyundai Mobis Co Ltd
Priority date: 2015-08-26
Filing date: 2016-08-09
Publication date: 2017-03-02
Also published as: DE202016004933U1; CN206054308U; KR20170024845A

Abstract

A lubrication system of an electric compressor may include a lower housing having a refrigerant inlet port formed to pierce an outer side plane thereof, a rotational shaft supported rotatably by the lower housing and a frame, a rotor for rotating the rotational shaft, an orbiting scroll disposed on a top portion of the frame to be orbited by the rotational shaft, a fixed scroll disposed on a top portion of the orbiting scroll to allow the orbiting scroll to orbit therein, and an upper housing disposed on a top portion of the fixed scroll and having a refrigerant outlet formed in an outer side plane thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of Korean Patent Application No. 10-2015-0120377, filed on Aug. 26, 2015, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUNDField

Exemplary embodiments relate to a lubrication system of an electric compressor, and more particularly, to a lubrication system of an electric compressor capable of reducing frictional loss occurring between an orbiting scroll and a fixed scroll.

Discussion of the Background

Scroll compressors are compressors for compressing a refrigerant gas by changing volume of a compression chamber defined by a pair of opposing scrolls. Scroll compressors have high efficiency, low vibration and noise levels, and can be more compact and more lightweight as compared to reciprocating compressors or rotary compressors, so that there is a trend that they are widely utilized in an air conditioning system.

Scroll compressors are broadly divided into low-pressure type scroll compressors and high-pressure type scroll compressors depending on pressure of a refrigerant filled in the internal space of their casing. The low-pressure type scroll compressor is a type where a suction pipe is in fluid contact with the internal space of a casing while a discharge pipe is in fluid contact with a discharge side of a compression unit so that a refrigerant is sucked indirectly into a compression chamber. In contrast, the high-pressure type scroll compressor is a type where a suction pipe is in fluid contact directly with a suction side of a compression unit while a discharge pipe is in fluid contact with the internal space of a casing so that a refrigerant is sucked directly into a compression chamber.

The low pressure type scroll compressor is constituted such that the internal space of the casing is divided into a suction space and a discharge space while the compression unit is arranged between the suction space and the discharge space. Further, as for types of sealing between the fixed scroll and the orbiting scroll in the low-pressure type scroll compressors, a tip seal type and a back pressure type are widely known. A tip seal type is a type where tip seals are provided on leading end faces of the wraps of each scroll, respectively, such that the tip seals cling to an opposite mirror plate portion to seal the compression chamber. A back pressure type is a type where a backside of the fixed scroll or the orbiting scroll is pressed such that the wraps and mirror plate portions of both scrolls cling to each other to seal the compression chamber.

There is a technique wherein a conventional low-pressure type scroll compressor is provided with a back pressure control mechanism for controlling the pressure in a back pressure chamber in connection with the pressure of a discharging refrigerant such that the orbiting scroll is supported by the pressure in the back pressure chamber without any internal leakage or power loss.

The back pressure control mechanism is installed in either a fixed scroll or a housing and includes a high pressure passage connecting the back pressure control mechanism to a discharge chamber, a back pressure passage connecting the back pressure control mechanism to the back pressure chamber, and a low pressure passage connecting the back pressure control mechanism to a suction chamber. Further, the high pressure passage, the back pressure passage and the low pressure passage are formed as capillary tubes such that pressure can be reduced when the refrigerant is transferred through each of the passages.

However, in the prior art as described above, there is a problem in that it is difficult to actively control the pressure in the back pressure chamber to cope with a variation of operating conditions because the pressure in the back pressure chamber is determined mainly by the shape and dimension of the flow path of the capillary tubes constituting the high pressure and back pressure passages. Furthermore, there is a problem in that oil is excessively introduced into the back pressure chamber and fluid resistance against the movement of a counterweight in the back pressure chamber is increased. Moreover, since additional components such as a back pressure control mechanism for selecting a flow path is required to be installed in the compressor, there is also a problem that the unit cost of manufacturing the compressor rose due to increase in the number of components and processing steps.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

Exemplary embodiments provide a lubrication system of an electric compressor having oil injection holes which are machined to inject oil directly into a compression chamber and a suction chamber and a back pressure hole which is machined in a mirror plate of an orbiting scroll wrap.

Additional aspects will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concept.

According to exemplary embodiments, a lubrication system of an electric compressor includes a lower housing having a refrigerant inlet port formed to pierce an outer side plane thereof, a rotational shaft supported by the lower housing and a frame, a rotor for rotating the rotational shaft, an orbiting scroll disposed on a top portion of the frame to be orbited by the rotational shaft, a fixed scroll disposed on a top portion of the orbiting scroll so as to allow the orbiting scroll to orbit therein, and an upper housing disposed on a top portion of the fixed scroll and having a refrigerant outlet formed in an outer side plane thereof.

The fixed scroll may include a fixed scroll mirror plate in a disc shape disposed horizontally, a discharge port piercing a center of the fixed scroll mirror plate in a vertical direction, an outer side plane formed to protrude downward along an outer peripheral surface of the fixed scroll mirror plate, a plurality of suction ports piercing the outer side plane in a horizontal direction, a fixed scroll wrap in a spiral shape protruding vertically from a bottom plane of the fixed scroll mirror plate, and a suction chamber that is a space formed between the fixed scroll wrap and the outer side plane.

The upper housing may include a discharge chamber connected with the discharge port, an oil separation chamber connected with the discharge chamber and provided with an oil separation tube for separating refrigerant and oil which are pressurized in the compression chamber, and an oil chamber connected with the oil separation chamber and storing oil separated from the oil separation tube.

The lubrication system of an electric compressor may include an oil groove formed on a top plane of the fixed scroll mirror plate to bypass a bottom plane of the discharge chamber and having one end connected with a bottom plane of the oil chamber and where the other end reaches a top portion of an outer side end of the fixed scroll wrap.

The orbiting scroll may include an orbiting scroll mirror plate in a disc shape disposed horizontally, an orbiting scroll wrap formed in a spiral shape and protruding in a vertical direction from the top plane of the orbiting scroll mirror plate so as to be disposed crisscross at an angle of about 180 degrees with respect to the fixed scroll wrap, and a back pressure hole piercing the orbiting scroll mirror plate in a vertical direction.

The lubrication system of an electric compressor may include a compression chamber for compressing the refrigerant and the oil flowing therein through the suction port, wherein the compression chamber is defined by being surrounded by the fixed scroll mirror plate, the fixed scroll wrap, the orbiting scroll mirror plate, and the orbiting scroll wrap.

The lubrication system of an electric compressor may include a back pressure chamber connected with the compression chamber via the back pressure hole, wherein back pressure chamber is defined by being surrounded by the bottom plane of the orbiting scroll mirror plate and the frame.

The lubrication system of an electric compressor may include a first oil injection hole formed to pierce the top plane of the fixed scroll mirror plate in a vertical direction to communicate fluidly with the oil groove and thus the compression chamber.

The lubrication system of an electric compressor may include a second oil injection hole formed to pierce the fixed scroll wrap in a vertical direction at the other end of the oil groove.

The lubrication system of an electric compressor may include an eccentric counterweight fastened to an upper end of the rotational shaft and disposed in the back pressure chamber.

The lubrication system of an electric compressor may include a thrust plate disposed between the frame and the orbiting scroll.

The lubrication system of an electric compressor may include an Oldham pin for fastening the frame and the thrust plate.

The lubrication system of an electric compressor may include a lip seal for sealing a space between the frame and the rotational shaft.

According to exemplary embodiments, it is possible to reduce frictional losses occurring between the orbiting scroll and the fixed scroll, enhance formation of a fluid film on the fixed scroll wrap, and reduce leakage of compressed refrigerant, thereby increasing efficiency of the compressor.

Further, it is possible to form an optimum back pressure by introducing oil and refrigerant in an intermediate pressure in the compression chamber into the back pressure chamber and thereby actively controlling back pressure depending on operating conditions.

The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the inventive concept, and, together with the description, serve to explain principles of the inventive concept.

FIG. 1 is an exploded perspective view of a lubrication system of an electric compressor according to an exemplary embodiment.

FIGS. 2 and 3 are cross-sectional views of a lubrication system of an electric compressor according to an exemplary embodiment.

FIG. 4 is a view illustrating a coupling relationship between an upper housing and a fixed scroll in a lubrication system of an electric compressor according to an exemplary embodiment.

FIG. 5 is a perspective view of an assembly of an upper housing and a fixed scroll in a lubrication system of an electric compressor according to an exemplary embodiment.

FIG. 6 is a view illustrating arrangement of an oil chamber, an oil groove and oil injection holes in a lubrication system of an electric compressor according to an exemplary embodiment.

FIGS. 7 and 8 are a view illustrating arrangement of oil injection holes in a lubrication system of an electric compressor according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments. It is apparent, however, that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring various exemplary embodiments.

In the accompanying figures, the size and relative sizes of films, panels, regions, etc., may be exaggerated for clarity and descriptive purposes. Also, like reference numerals denote like elements.

When an element is referred to as being “on,” “connected to,” or “coupled to” another element it may be directly on, connected to, or coupled to the other element or intervening elements may be present. When, however, an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element there are no intervening elements present. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, etc. may be used herein to describe various elements, components, regions, and/or sections, these elements, components, regions, and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, and/or section from another element, component, region, and/or section. Thus, a first element, component, region, and/or section discussed below could be termed a second element, component, region, and/or section without departing from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for descriptive purposes, and, thereby, to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of an apparatus in use, operation, and/or manufacture in addition to the orientation depicted in the drawings. For example, if the apparatus in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. Furthermore, the apparatus may be otherwise oriented (e.g., rotated90 degrees or at other orientations), and, as such, the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Various exemplary embodiments are described herein with reference to sectional illustrations that are schematic illustrations of idealized exemplary embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments disclosed herein should not be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. As such, the regions illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein.

Exemplary embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a lubrication system of an electric compressor according to an exemplary embodiment.FIGS. 2 and 3 are cross-sectional views of a lubrication system of an electric compressor according to an exemplary embodiment.

Referring toFIGS. 1, 2, and 3, the lubrication system of an electric compressor according to the present disclosure may include alower housing100 having arefrigerant inlet port110 formed to pierce an outer side plane thereof, arotational shaft300 supported by thelower housing100 and aframe200, arotor400 for rotating therotational shaft300, anorbiting scroll500 disposed on a top portion of theframe200 to be orbited by therotational shaft300, afixed scroll600 disposed on a top portion of theorbiting scroll500 so as to allow theorbiting scroll500 to orbit therein; and anupper housing700 disposed on a top portion of the fixedscroll600 and having arefrigerant outlet710 formed in an outer side thereof. The lubrication system of an electric compressor may include athrust plate1400 disposed between theframe200 and theorbiting scroll500, anOldham pin1500 for fastening theframe200 and thethrust plate1400, and alip seal1600 for sealing a space between theframe200 and therotational shaft300.

The fixedscroll600 may include a fixedscroll mirror plate610 in a disc shape disposed horizontally, adischarge port620 piercing a center of the fixedscroll mirror plate610 in a vertical direction; anouter side plane630 formed to protrude downward along an outer peripheral surface of the fixedscroll mirror plate610, a plurality ofsuction ports640 piercing theouter side plane630 in a horizontal direction, afixed scroll wrap650 in a spiral shape protruding vertically from a bottom plane of the fixedscroll mirror plate610, and asuction chamber660 that is a space formed between thefixed scroll wrap650 and theouter side plane630.

Theupper housing700 may include adischarge chamber720 connected with thedischarge port620, anoil separation chamber740 connected with thedischarge chamber720 and provided with anoil separation tube730 for separating refrigerant and oil which are pressurized in thecompression chamber800, and anoil chamber750 connected with theoil separation chamber740 and storing oil separated from theoil separation tube730.

The lubrication system of an electric compressor may include anoil groove1000 formed on a top plane of the fixedscroll mirror plate610 to bypass a bottom plane of thedischarge chamber720 and having one end connected with a bottom plane of theoil chamber750 and where the other end reaches a top portion of an outer side end of the fixedscroll wrap650.

Theorbiting scroll500 may include an orbitingscroll mirror plate510 formed in a disc shape and disposed horizontally, anorbiting scroll wrap520 formed in a spiral shape and protruding in a vertical direction from the top plane of the orbitingscroll mirror plate510 so as to be disposed crisscross at an angle of about180 degrees with respect to the fixedscroll wrap650, and aback pressure hole530 piercing the orbitingscroll mirror plate510 in a vertical direction.

The lubrication system of an electric compressor may include acompression chamber800 for compressing the refrigerant and the oil flowing therein through thesuction port640, wherein the compression chamber is defined by being surrounded by the fixedscroll mirror plate610, the fixedscroll wrap650, the orbitingscroll mirror plate510, and theorbiting scroll wrap520.

The lubrication system of an electric compressor may include aback pressure chamber900 connected with thecompression chamber800 via theback pressure hole530, wherein theback pressure chamber900 is defined by being surrounded by the bottom plane of the orbitingscroll mirror plate510 and theframe200. Theback pressure hole530 may be machined at a position where pressure in theback pressure chamber900 can be controlled actively. Accordingly, it is possible to maintain an optimal back pressure for every operating condition so that performance of the compressor can be optimized.

Further, the lubrication system of an electric compressor may include a firstoil injection hole1100 formed to pierce the top plane of the fixedscroll mirror plate610 in a vertical direction to communicate fluidly with theoil groove1000 and thecompression chamber800, a secondoil injection hole1200 formed to pierce the fixedscroll wrap650 in a vertical direction at the other end of theoil groove1000, and aneccentric counterweight1300 fastened to an upper end of therotational shaft300 and disposed in theback pressure chamber900.

FIG. 4 is a view illustrating a coupling relationship between an upper housing and a fixed scroll in a lubrication system of an electric compressor according to an exemplary embodiment andFIG. 5 is a perspective view of an assembly of an upper housing and a fixed scroll in a lubrication system of an electric compressor according to an exemplary embodiment.FIG. 6 is a view illustrating arrangement of an oil chamber, an oil groove and oil injection holes in a lubrication system of an electric compressor according to an exemplary embodiment andFIGS. 7 and 8 are a view illustrating arrangement of oil injection holes in a lubrication system of an electric compressor according to an exemplary embodiment. Hereinafter, operation of the present disclosure will be described with reference toFIGS. 4, 5, 6, 7, and 8.

Refrigerant in a relatively low pressure state introduced into therefrigerant inlet port110 of thelower housing100 flows into thesuction chamber660 through thesuction ports640. At this time, the refrigerant flows into the suction chamber along with oil in the compressor. Furthermore, at the same time, the oil flows into thesuction chamber660 through thesuction ports640 submerged in the oil (seeFIGS. 2 and 5).

The refrigerant and oil introduced into thesuction chamber660 are compressed as theorbiting scroll500 rotates, and the compressed refrigerant and oil, which are in a relatively high pressure state, flow into thedischarge chamber720 through the discharge port620 (see solid line inFIG. 4).

The refrigerant and oil introduced into thedischarge chamber720 flows into theoil separation chamber740 and then collides against the outer wall of theoil separation tube730. After the collision, the lighter weight gas may be discharged to the outside of the compressor through arefrigerant outlet pipe710, whereas the heavier weight oil may drop to the bottom portion of theoil separation chamber740 due to gravity and then collected within the oil chamber750 (see dashed lines inFIGS. 2 and 4).

The oil collected within theoil chamber750 moves upward along theoil groove1000 and pressure of the oil is depressurized due to friction and the like while moving upward (seeFIG. 4). This is intended to prevent efficiency of the compressor from being deteriorated due to injection of the oil at a high pressure when the oil is injected into thecompression chamber800, or thesuction chamber660, etc. after the oil is collected.

The oil rising along theoil groove1000 is injected first from the firstoil injection hole1100 directly into thecompression chamber800. Accordingly, it is possible to reduce frictional losses occurring at the tip of theorbiting scroll wrap520 or the fixedscroll wrap650. Further, there is an effect of sealing theorbiting scroll wrap520 or the fixedscroll wrap650 and hence it is possible to reduce leakage of the compressed refrigerant, so that efficiency of the compressor is improved. Moreover, since the oil discharged into thecompression chamber800 is supplied to theback pressure chamber900 through theback pressure hole530, frictional losses occurring at the inside of theback pressure chamber900 is also reduced.

The remainder of the oil rising along theoil groove1000 is discharged from the secondoil injection hole1200 to the other end of the fixedscroll wrap650. Accordingly, since the oil is injected directly to a frictional area between thefixed scroll wrap650 and the orbitingscroll mirror plate510, frictional loss is reduced and the oil having a relatively high pressure is depressurized to a lower pressure. Further, the oil can be discharged from the secondoil injection hole1200, which serves to supply oil to the suction chamber.

Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concept is not limited to such embodiments, but rather to the broader scope of the presented claims and various obvious modifications and equivalent arrangements.

Claims

What is claimed is:

1. A lubrication system of an electric compressor comprising:

a lower housing comprising a refrigerant inlet port disposed to pierce an outer side plane thereof;

a rotational shaft supported by the lower housing and a frame;

a rotor for rotating the rotational shaft;

an orbiting scroll disposed on a top portion of the frame to be orbited by the rotational shaft;

a fixed scroll disposed on a top portion of the orbiting scroll to allow the orbiting scroll to orbit therein; and

an upper housing disposed on a top portion of the fixed scroll and comprising a refrigerant outlet disposed in an outer side plane thereof.

2. The lubrication system according toclaim 1, wherein the fixed scroll comprises:

a fixed scroll mirror plate in a disc shape disposed horizontally;

a discharge port piercing a center of the fixed scroll mirror plate in a vertical direction;

an outer side plane disposed to protrude downward along an outer peripheral surface of the fixed scroll mirror plate;

a plurality of suction ports piercing the outer side plane in a horizontal direction;

a fixed scroll wrap in a spiral shape protruding vertically from a bottom plane of the fixed scroll mirror plate; and

a suction chamber that is a space formed between the fixed scroll wrap and the outer side plane.

3. The lubrication system according toclaim 2, wherein the upper housing comprises:

a discharge chamber connected with the discharge port;

an oil separation chamber connected with the discharge chamber and provided with an oil separation tube for separating refrigerant and oil pressurized; and

an oil chamber connected with the oil separation chamber and storing oil separated from the oil separation tube.

4. The lubrication system according toclaim 3, wherein the lubrication system comprises an oil groove formed on a top plane of the fixed scroll mirror plate to bypass a bottom plane of the discharge chamber and comprising one end of the oil groove connected with a bottom plane of the oil chamber and where an other end of the oil groove reaches an upper s portion of an outer side end of the fixed scroll wrap.

5. The lubrication system according toclaim 4, wherein the orbiting scroll comprises:

an orbiting scroll mirror plate formed in a disc shape and disposed horizontally;

an orbiting scroll wrap formed in a spiral shape and protruding in a vertical direction from the top plane of the orbiting scroll mirror plate so as to be disposed crisscross at an angle of 180 degrees with respect to the fixed scroll wrap; and

a back pressure hole formed through the orbiting scroll mirror plate in a vertical direction.

6. The lubrication system according toclaim 5, wherein the lubrication system comprises a compression chamber for compressing the refrigerant and the oil flowing therein through the suction port, the compression chamber being defined by being surrounded by the fixed scroll mirror plate, the fixed scroll wrap, the orbiting scroll mirror plate and the orbiting scroll wrap.

7. The lubrication system according toclaim 6, wherein the lubrication system comprises a back pressure chamber connected with the compression chamber via the back pressure hole, the back pressure chamber being defined by being surrounded by a bottom plane of the orbiting scroll mirror plate and the frame.

8. The lubrication system according toclaim 7, wherein the lubrication system comprises a first oil injection hole formed to pierce the top plane of the fixed scroll mirror plate in a vertical direction to communicate fluidly with the oil groove and the compression chamber.

9. The lubrication system according toclaim 4, wherein the lubrication system comprises a second oil injection hole formed to pierce the fixed scroll wrap in a vertical direction at the other end of the oil groove.

10. The lubrication system according toclaim 7, wherein the lubrication system comprises an eccentric counterweight fastened to an upper end of the rotational shaft and disposed in the back pressure chamber.

11. The lubrication system according toclaim 1, wherein the lubrication system comprises a thrust plate disposed between the frame and the orbiting scroll.

12. The lubrication system according toclaim 11, wherein the lubrication system comprises an Oldham pin for fastening the frame and the thrust plate.

13. The lubrication system according toclaim 1, wherein the lubrication system comprises a lip seal for sealing a space between the frame and the rotational shaft.