MOTOR-OPERATED COMPRESSOR

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(a) to Korean Patent Application No. 10-2019-0046347, filed on Apr. 19, 2019, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND
1. Technical Field

The present disclosure relates to a compressor, and more particularly, to a motor-operated compressor employing a scroll compression method and driven by a motor.

2. Description of the Related Art

Compressors are classified into a mechanical type driven by an engine and a motor-operated type driven by a motor. A motor-operated compressor mainly employs a scroll compression method suitable for a high compression ratio operation among various compression methods.

In the scroll type motor-operated compressor (hereinafter, referred to as “motor-operated compressor”), a motor unit configured as a drive motor is installed in a hermetic casing, and a compression unit configured by a fixed scroll and an orbiting scroll is disposed at one side of the motor unit. The motor unit and the compression unit are connected to each other by a rotating shaft so that a rotational force of the motor unit is transferred to the compression unit. The rotational force transmitted to the compression unit allows a fluid, such a refrigerant, to be compressed.

The motor-operated compressor can be installed in an electric vehicle to create a refrigeration cycle. Electric cars have a lower power output than engine-powered vehicles, and thus, it is important to reduce weight of automotive components as possible. Accordingly, a small and lightweight motor-operated compressor is more advantageous in terms of reducing an installation space and weight reduction.

However, in the related art motor-operated compressor, as a fixed scroll and an orbiting scroll constituting a compression unit is supported by a frame, there is a limitation in reducing a size and weight of the compressor. Korean Patent Laid-Open Publication No. 10-2014-0136796 (hereinafter, “Patent Document 1”), which is hereby incorporated by reference, discloses a compressor in which a frame that supports a fixed scroll and an orbiting scroll is excluded or removed by using the fixed scroll to serve as the frame. However, the compressor disclosed in Patent Document 1 is mainly developed for an air conditioning system, and a vertical type compressor in which a motor unit and a compression unit are arranged in a vertical direction. A compressor used in vehicles is, generally, a horizontal type compressor in which a motor unit and a compression unit are arranged in a horizontal direction. Accordingly, the compressor of Patent Document 1 is not suitable for the vehicles. Thus, there is a need to develop a horizontal and frame scroll type motor-operated compressor applicable to the vehicles.

SUMMARY

An aspect of the present disclosure is to provide a horizontal type motor-operated compressor equipped with a frame scroll.

Another aspect of the present disclosure is to provide a motor-operated compressor that can smoothly supply oil to a bearing surface by simplifying an oil supply structure while increasing a space for storing oil separated from a refrigerant, even when a horizontal type and a frame scroll are employed.

Still another aspect of the present disclosure is to provide a motor-operated compressor that can simplify an oil supply structure by providing an oil supply passage at a rear housing and an orbiting scroll facing the rear housing, and facilitate manufacturing of the rear housing by simplifying an inner structure of the rear housing, even when a horizontal type and a frame scroll are employed.

Still another aspect of the present disclosure is to provide a motor-operated compressor that can reduce manufacturing costs by reducing a number of sealing members provided at the adjacent to an orbiting scroll, even when a horizontal type and a frame scroll are employed.

Embodiments disclosed herein provide a motor-operated compressor that may include a frame scroll disposed to face a drive motor, an orbiting scroll engaged with the frame scroll to form a compression space, and a housing provided at an opposite side of the frame scroll to support the orbiting scroll. The housing may be provided with a discharge space. A scroll support portion having an annular shape may be formed along a circumference of the discharge space.

Embodiments disclosed herein further provide a motor-operated compressor that may include a frame scroll, an orbiting scroll, and a rear housing sequentially with respect to a drive motor. The rear housing may include a first space communicating with a discharge port, and a second space communicating with the first space and provided with an exhaust port. The first space may communicate with a gap between the orbiting scroll and the frame scroll via an oil passage provided at the rear housing and the orbiting scroll.

In addition, in a frame scroll type motor-operated compressor, a thrust plate may be provided between an orbiting scroll and a housing that supports the orbiting scroll in a direction toward a frame scroll. A sealing member may be provided at both side surfaces of the thrust plate, respectively. A pressure reducing member may be provided at the orbiting scroll or a rotating shaft coupled to the orbiting scroll.

Embodiments disclosed herein provide a motor-operated compressor that may include a main housing, a motor unit disposed at one end of the main housing, a rotating shaft coupled to the motor unit, a fixed scroll disposed at another end of the main housing facing the motor unit, wherein the rotating shaft is rotatably coupled to the fixed scroll, an orbiting scroll coupled to the rotating shaft and configured to perform an orbiting motion with respect to the fixed scroll, wherein the orbiting scroll is configured to form a compression space together with the fixed scroll, and wherein the orbiting scroll comprises a discharge port, and a rear housing disposed to face one side surface of the orbiting scroll opposite to a side of the orbiting scroll facing the fixed scroll. The rear housing may be coupled to the main housing. The rear housing may comprise a space portion configured to communicate with the discharge port of the orbiting scroll. A scroll support portion protruding in a radial direction may be formed on an inner circumferential surface of the rear housing and may define the space portion.

Here, an oil return passage may be formed through both side surfaces of the scroll support portion in an axial direction. The orbiting scroll may comprise an oil guide passage configured to communicate with the oil return passage to guide oil introduced through the oil return passage to a bearing surface.

A thrust plate may be provided between the orbiting scroll and the rear housing. The thrust plate may be fixedly coupled between the rear housing and the fixed scroll, and the first thrust plate may include a first oil communication hole configured to provide communication between the oil return passage and the oil guide passage.

In addition, a sealing member may be provided between the rear housing and the thrust plate. The sealing member may include a second oil communication hole configured to provide communication between the first oil communication hole and the oil guide passage.

Further, the scroll support portion may include a sealing groove, the sealing member may be configured to be inserted in the sealing groove, and the oil return passage may be configured to communicate with the sealing groove.

The sealing member may be constrained in a circumferential direction with respect to the rear housing. An inner diameter of the oil guide passage may be greater than an inner diameter of the first oil communication hole.

In addition, a fixing pin may be provided between the rear housing and the sealing member.

The sealing member may be constrained in a circumferential direction with respect to the thrust plate. An inner diameter of the oil guide passage may be greater than an inner diameter of the first oil communication hole.

In addition, the scroll support portion may include a sealing groove, and a sealing member may be configured to be inserted in the sealing groove. The oil return passage may be located inward or outward than the sealing groove.

An inner diameter of the oil guide passage may be greater than an inner diameter of the oil return passage or an inner diameter of the first communication hole.

In addition, a rotating shaft coupling portion may be provided at a central portion of the orbiting scroll. An oil guide passage may be provided at the rotating shaft coupled to the rotating shaft coupling portion to communicate with the oil guide passage. The oil guide passage may include an oil supply groove formed at the rotating shaft in an axial direction and at least one oil supply hole. The at least one oil supply hole may penetrate from an inner circumferential surface of the oil supply groove to an outer circumferential surface of the rotating shaft.

The oil guide passage may be configured to communicate with the rotating shaft coupling portion.

Further, the oil guide passage may be formed through an orbiting wrap of the orbiting scroll protruding toward the fixed scroll.

The fixed scroll may include a main bearing configured to radially support one side of the rotating shaft. The rotating shaft coupling portion may include an eccentric bearing configured to radially support another side of the rotating shaft. A second gap between the rotating shaft and the eccentric bearing may be greater than a first gap between the rotating shaft and the main bearing.

An oil supply communication groove may be provided at an end of the orbiting wrap facing the fixed scroll. The oil communication groove may be configured to communicate with an inner surface of the rotating shaft coupling portion.

An outer circumferential surface of the rotating shaft corresponding to an inner circumferential surface of the eccentric bearing may include at least one oil communication groove recessed therefrom.

In addition, at least one of the oil guide passage or the oil supply passage may include a flow controller configured to control an amount of oil.

Embodiments disclosed herein may further provide a motor-operated compressor that may include a drive motor, a frame scroll disposed to face the drive motor, an orbiting scroll coupled to the frame scroll, the orbiting scroll being configured to form a compression space, and a housing disposed at an opposite side of the frame scroll, the housing being configured to support the orbiting scroll. The housing may comprise a discharge space, and the discharge space may comprise an opened side facing the orbiting scroll. The opened side of the discharge space may comprise a scroll support portion extending in an annular shape. The scroll support portion may include a first passage penetrating in an axial direction. The orbiting scroll may include a second passage communicating with the first passage. The second passage may be configured to communicate with the compression space.

Here, the scroll support portion may include a sealing groove, and the sealing member may be configured to be inserted into a surface of the scroll support facing the orbiting scroll. The first passage may be configured to communicate with the sealing groove, and a communication hole may be provided at the sealing member when the sealing member is inserted into the sealing groove to communicate the first passage and the second passage with each other.

The orbiting scroll may include a rotating shaft coupling portion, and the rotating shaft may be coupled to the rotating shaft coupling portion. The second passage may be configured to communicate with the rotating shaft coupling portion. The rotating shaft may comprise a third communication passage configured to provide communication between the second passage and the compression space.

Embodiments disclosed herein may further provide a motor-operated compressor that may comprise a first housing having a hollow cylindrical shape extending in a horizontal direction, a drive motor disposed at one end of the first housing, a rotating shaft coupled to the drive motor, a compression unit comprising a fixed scroll and an orbiting scroll, and a second housing coupled to a rear end of the first housing. The first housing may surround the drive motor. The fixed scroll may be disposed to face the drive motor, and the orbiting scroll may be coupled to the fixed scroll and configured to form a compression space. The orbiting scroll may include a discharge port. The second housing may comprise a space portion configured to communicate with the discharge portion of the orbiting scroll.

The motor-operated compressor may further include a scroll support portion protruding in a radial direction formed on an inner circumferential surface of the second housing. An oil return passage may be formed through both side surfaces of the scroll support portion in an axial direction. The orbiting scroll may include an oil guide passage configured to communicate with the oil return passage to guide oil introduced through the oil return passage to a bearing surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an outer appearance of a motor-operated compressor according to an embodiment of the present disclosure;

FIG. 2 is an exploded perspective view of the motor-operated compressor of FIG. 1 according to an embodiment of the present disclosure;

FIG. 3 is an assembled cross-sectional view of an inside of the motor-operated compressor of FIG. 1 according to an embodiment of the present disclosure;

FIG. 4 is a cross-sectional view illustrating a coupled state of a fixed scroll and an orbiting scroll in a compression unit according to an embodiment of the present disclosure;

FIG. 5 is a perspective view of the orbiting scroll, viewed from the rear, according to an embodiment of the present disclosure;

FIG. 6 is a perspective view of a rear housing, viewed from the front, according to an embodiment of the present disclosure;

FIG. 7 is a cross-sectional view of a portion of the motor-operated compressor for explaining one embodiment of an oil supply structure according to an embodiment of the present disclosure;

FIG. 8 is an enlarged cross-sectional view illustrating a portion “A” of FIG. 7 according to an embodiment of the present disclosure;

FIG. 9 is a planar view illustrating one embodiment of a fixing structure in which a second sealing member is fixed to the rear housing according to an embodiment of the present disclosure;

FIG. 10 is a cross-sectional view taken along line “VI-VI” of FIG. 9 according to an embodiment of the present disclosure;

FIG. 11 is a front view illustrating another embodiment of the fixing structure of the second sealing member in FIG. 7 according to an embodiment of the present disclosure.

FIG. 12 is a cross-sectional view taken along line “VII-VII” of FIG. 11 according to an embodiment of the present disclosure.

FIG. 13 is another cross-sectional view taken along line “VII-VII” of FIG. 11 according to an embodiment of the present disclosure.

FIG. 14 is a cross-sectional view illustrating another embodiment of the oil supply structure according to an embodiment of the present disclosure;

FIG. 15 is a cross-sectional view taken along line “VIII-VIII” of FIG. 14, illustrating an enlarged cross-section of a rotating shaft coupling portion, according to an embodiment of the present disclosure;

FIG. 16 is a cross-sectional view comparing a gap of a main bearing and a gap of an eccentric bearing in FIG. 14 according to an embodiment of the present disclosure; and

FIG. 17 is a cross-sectional view taken along line ““IX-IX” of FIG. 14, illustrating an oil passage provided on an outer circumferential surface of an eccentric portion according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Description will now be given in detail of a motor-operated compressor according to exemplary embodiments disclosed herein, with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating an outer appearance of a motor-operated compressor according to an embodiment of the present disclosure.

Referring to FIG. 1, a motor-operated compressor 100 according to this embodiment may include a compression module 101 and an inverter module 102. The compression module 101 may refer to a set of parts (or components) for compressing a fluid such as a refrigerant, and the inverter module 102 may refer to a set of parts for controlling driving of the compression module 101. The inverter module 102 may be coupled to a front side of the compression module 101. Hereinafter, a side where the inverter module 102 is installed may be referred to as a “front side”, and a side where the compression module 101 is installed may be referred to as a “rear side”, respectively. As a fluid (hereinafter, “refrigerant”) to be compressed or pressurized is introduced into an inlet port 111 and is then discharged to an exhaust port 126, the inverter module 102 disposed close to the inlet port 111 may be coupled to the front side of the compression module 101, which may be more suitable for cooling the inverter module 101.

The outer appearance of the compression module 101 may be defined by a main housing 110, which may be a first housing, and a rear housing 120, which may be a second housing. For example, the main housing 110 may have a closed front end and an opened rear end, and the rear housing 120 may have an opened front end and a closed rear end. Accordingly, the rear end of the main housing 110 and the front end of the rear housing 120 may communicate with each other to form a sealed casing for the compression module 101.

FIG. 2 is an exploded perspective view of the motor-operated compressor of FIG. 1, and FIG. 3 is an assembled cross-sectional view of an inside of the motor-operated compressor of FIG. 1.

Referring to these drawings, the main housing 110 may have a hollow cylindrical shape, the main housing 110 may have a hollow cylindrical shape, a hollow polygonal cylinder shape, or the like. The main housing 110 may be disposed to extend toward a horizontal direction. The main housing 110 may surround or cover a motor unit 130 to be described hereinafter. One axial end of the main housing 110 may be closed, and another axial end of the main housing 110 may be opened.

The inlet port 111 may be provided at an outer circumferential surface of the main housing 110. The inlet port 111 may provide a flow path that supplies a refrigerant (e.g., R134a, R32, CO2, etc.) to an inner space of the compression module 101.

A first scroll support portion 112 that axially supports a support protrusion 143 of a fixed scroll 140 to be described hereinafter may be provided on an inner circumferential surface of the rear end of the main housing 110. The first scroll support portion 112 may be formed in a stepped manner to have an arc shape, or may be formed in a stepped manner to have an annular shape.

The rear housing 120 may be coupled to the rear end of the main housing 110. The rear housing 120 may cover the rear end of the main housing 110. The exhaust port 126 may be provided at the rear housing 120, and an oil separator 123a may be installed at the exhaust port 126.

In addition, the rear housing 120 may be disposed to face a rear surface of an orbiting scroll 150 to be described hereinafter, so as to form a scroll accommodating portion 121, a discharged oil storage space 122, and an oil separation space 123.

Referring back to FIGS. 2 and 3, as for the compression module 101, the motor unit 130 (drive unit or drive motor) and a compression unit 105 may be axially disposed in an inner space of the main housing 110 defining a portion or part of the casing, and the motor unit 130 and the compression unit 105 may be connected by a rotating shaft 160. The motor unit 130 may be located at a front side of the main housing 110, and the compression unit 105 may be located at a rear side of the main housing 110.

Here, as the inlet port 111 is provided at the main housing 110, the inner space of the main housing 110 may form a suction space S1, and thus, the motor unit 130 and the compression unit 105 may be located at the suction space S1 forming a suction pressure. Therefore, the suction space S1 may also be referred to as a motor chamber.

The motor unit 130 may be configured to generate a driving force required for the orbiting scroll 150 of the compression unit 105 to perform an orbiting motion. The motor unit 130 may also be referred to as a drive motor, and configured as an electric motor.

The motor unit 130, or the drive motor may include a stator 131 and a rotor 132.

The stator 131 may be fixedly inserted into an inner circumferential surface of the main housing 110 in a shrink-fitting manner (or hot press fitting). Alternatively, the stator 131 may be fixed by welding after insertion or may be fixed by using another fixing member.

The rotor 132 may be disposed inside the stator 131 in a rotatable manner. When electric power is applied to the stator 131, the rotor 132 may be rotated by electromagnetic interaction with the stator 131.

The rotating shaft 160 may be coupled to a center of the rotor 132. An eccentric portion 164 may be provided at the rotating shaft 160 to be eccentrically coupled to the orbiting scroll 150. This may allow a rotational force of the drive motor to be transferred to the orbiting scroll 150 by the rotating shaft 60.

FIG. 4 is cross-sectional view illustrating a coupled state of a fixed scroll and an orbiting scroll in a compression unit according to an embodiment of the present disclosure.

Referring to FIG. 4, the compression unit 105 may be configured to compress a refrigerant. The compression unit 105 may include the fixed scroll (a frame scroll and the fixed scroll may be the same member, so hereinafter the frame scroll and the fixed scroll may be interchangeably used) 140 defining the frame scroll and the orbiting scroll 150. The compression unit 105 may be defined by the fixed scroll 140 and the orbiting scroll 150. The fixed scroll 140 and the orbiting scroll 150 may also be referred to as a first scroll and a second scroll, respectively.

The fixed scroll 140 and the orbiting scroll 150 may be coupled to each other to form a pair of compression chambers. As the orbiting scroll 150 performs an orbiting motion, a volume of the compression chambers may be repeatedly changed, and a refrigerant may be compressed in the compression chambers, accordingly.

Referring back to FIG. 3, the fixed scroll 140 may be located relatively close to the motor unit 130, and the orbiting scroll 150 may be located relatively far from the motor unit 130. The fixed scroll 140 may be disposed between the orbiting scroll 150 and the main housing 110 in an axial direction. The orbiting scroll 150 may be disposed between the fixed scroll 140 and the rear housing 120 in the axial direction.

The fixed scroll 140 may include a fixed end plate 141 and a fixed wrap 142.

The fixed end plate 141 may have a substantially disk shape. A plurality of support protrusions 143 having an annular shape may be provided at an outer circumferential surface of the fixed end plate 141 along a circumferential direction. A bolt passing groove 143c through which a coupling bolt (not shown) passes may be provided on an outer circumferential surface of the support protrusions 143, respectively, to be spaced apart by predetermined intervals along the circumferential direction.

A first side surface 143a of the support protrusion 143 facing the drive motor may be supported in a forward axial direction by the first scroll support portion 112 provided on the inner circumferential surface of the main housing 110, and a second side surface 143b at an opposite side of the first side surface 143a may be supported in a rearward axial direction by a second scroll support portion 125 of the rear housing 120 described hereinafter. Accordingly, the fixed scroll 140 may be radially supported by the rear housing 120 and axially supported by the main housing 110 and the rear housing 120.

Here, a thrust plate 180 may be inserted between the second side surface 143b of the support protrusion 143 and the second scroll support portion 125 of the rear housing 120 so as to be fixed together with the fixed scroll 140.

In addition, a suction port 145 may be formed through the support protrusion 143 so that the suction space S1 and a suction chamber V1 communicate with each other. Accordingly, a radial height of the first scroll support surface 112 may be formed to an extent that does not cover the suction port 145.

Meanwhile, a scroll bearing portion 146 axially extending toward the drive motor may be provided at a central portion of the fixed end plate 141, and a rotating shaft accommodating portion 147 may be axially formed through the scroll bearing portion 146.

A main bearing 171 may be fixedly inserted into an inner circumferential surface of the rotating shaft bearing portion 147, so that a main bearing portion 162 of the rotating shaft 160 can be inserted and radially supported. The main bearing 171 may be configured as a ball bearing. In this embodiment, however, a bush bearing may be employed to reduce manufacturing costs.

A sealing member (not shown) may be provided at a front end of the rotating shaft accommodating portion 147, so as to seal between the rotating shaft 160 and the fixed scroll 140. Accordingly, as for the rotating shaft 160, the main bearing portion 162 provided at a rear side with respect to the rotor 132 of the drive motor (motor unit 130) may be radially supported by the fixed scroll 140.

A sub bearing portion 163 formed at a front side of the rotating shaft 160 may be supported by a sub bearing 172 provided at a front side surface of the main housing 110. The sub bearing 172, configured as a ball bearing, may be insertedly coupled to a shaft support portion 113 provided at a front inner surface of the main housing 110. As the sub bearing 172 is implemented as the ball bearing, the rotating shaft 160 may be radially and axially supported by the sub bearing 172.

Referring to FIG. 4, the fixed wrap 142 may protrude toward the orbiting scroll 150 from a second side surface 141b of the fixed end plate 141 facing the orbiting scroll 150. The fixed wrap 142 may have an involute shape. In this embodiment, however, the fixed wrap 142 may have a non-volute shape as the rotating shaft 160 penetrates through the fixed scroll 140 to be insertedly coupled to the orbiting scroll 150.

Referring back to FIG. 3, the orbiting scroll 150 may be disposed to face the fixed scroll 140. The orbiting scroll 150 may be coupled to the eccentric portion 164 provided at a rear end of the rotating shaft 160. Accordingly, the orbiting scroll 150 may be eccentrically coupled to the rotating shaft 160. The orbiting scroll 150 that receives a rotational force from the eccentric portion 164 may perform an orbiting motion by an anti-rotation mechanism 190.

The orbiting scroll 150 may include an orbiting end plate 151, an orbiting wrap 152, and a rotating shaft coupling portion 153.

The orbiting end plate 151 may have a disk shape corresponding to the fixed end plate 141. If the fixed end plate 141 has a cross section that corresponds to a disk (disc), then the orbiting end plate 151 may have a disk-shaped cross section.

Of both axial side surfaces of the orbiting end plate 151, when a surface facing the fixed scroll 140 is a first side surface 151a and a surface facing the rear housing 120 is a second side surface 151b, the orbiting wrap 152 may be provided at the first side surface 151a, and an anti-rotation groove 154 may be formed on the second side surface 151b. The anti-rotation groove 154 may be provided in plurality along the circumferential direction as shown in FIG. 2.

The orbiting wrap 152 may protrude from the first side surface 151a of the orbiting end plate 151 toward the fixed scroll 140 into an involute curve shape, an Archimedean spiral shape or a logarithmic spiral shape.

However, in this embodiment, the orbiting wrap 152 together with the fixed wrap 142 may be formed in a non-involute shape. This may be to reduce a pressure difference between compression pockets disposed outward with respect to the fixed wrap 142 and disposed inward with respect to the fixed wrap 142, as the rotating shaft 160 penetrates through the fixed scroll 140 to be coupled to the orbiting wrap 152 of the orbiting scroll 150 in a radially overlapping manner. For example, as illustrated in FIG. 4, the orbiting wrap 152 according to this embodiment may be provided with a protruding portion 153a formed at an end portion of a discharge side defining the rotating shaft coupling portion 153, so as to extend a crank angle (compression angle) of the inner side compression pocket. This may allow a compression period (or cycle) to be extended. Further, the pressure difference between the two compression pockets may be minimized by increasing a compression ratio of the inwardly disposed compression pocket.

The rotating shaft coupling portion 153 may be provided at a central portion of the orbiting end plate 151. The rotating shaft coupling portion 153 may protrude toward the fixed scroll 140 from the first side surface 151a of the orbiting end plate 151. The rotating shaft coupling portion 153 may be provided at a position corresponding to an involute base circle defining the orbiting wrap 152. Accordingly, the rotating shaft coupling portion 153 may form the innermost part or portion of the orbiting wrap 152.

The rotating shaft coupling portion 153 may have a hollow cylindrical shape so as to accommodate the eccentric portion 164 of the rotating shaft 160 therein. The rotating shaft coupling portion 153 may be formed to cover or surround the eccentric portion 164 of the rotating shaft 160.

The rotating shaft coupling portion 153 of the orbiting scroll 150 may have one opened side. For example, the rotating shaft coupling portion 153 of the orbiting scroll 150 may be opened toward the fixed scroll 140, but a rear surface thereof at an opposite side of the opened side may be blocked by the orbiting end plate 151. Accordingly, the eccentric portion 164 of the rotating shaft 160 may be inserted into the rotating shaft coupling portion 153 of the orbiting scroll 150, but may not penetrate through the orbiting end plate 151.

FIG. 5 is a perspective view of the orbiting scroll, viewed from the rear, according to an embodiment of the present disclosure.

Referring to FIG. 5, a plurality of anti-rotation grooves 154, a scroll-side sealing groove 155a, and a discharge guide groove 156 may be provided on the second side surface 151b of the orbiting end plate 151, respectively.

The plurality of anti-rotation grooves (precisely, anti-rotation rings) 154 and an anti-rotation pin 192 to be described hereinafter defining the anti-rotation mechanism 190 may be provided to suppress a rotary motion of the orbiting scroll 150. The plurality of anti-rotation grooves 154 may be disposed to be spaced apart by predetermined intervals along the circumferential direction. The plurality of anti-rotation grooves 154 may be formed to correspond to a plurality of anti-rotation pins 192, one by one. An anti-rotation ring 191 may be insertedly coupled to the plurality of anti-rotation grooves 154, respectively. Accordingly, the anti-rotation pin 192 may be rotatably inserted into the anti-rotation ring 191.

The scroll-side sealing groove 155a having an annular shape may be located at an outer side (edge portion) than the anti-rotation groove 154. More precisely, the scroll-side sealing groove 155a may be located outward than an oil guide passage 159 to be described hereinafter.

A front side sealing member (hereinafter referred to as “first sealing member”) 181 that seals between the orbiting scroll 150 and the thrust plate 180 to be described hereinafter may be inserted into the scroll-side sealing groove 155a. The first sealing member 181 may be provided between the second side surface 151b of the orbiting end plate 151 to seal between the discharged oil storage space 122 and the oil guide passage 159.

The discharge guide groove 156 may be engraved or depressed from the second side surface 151b of the orbiting end plate 151 by a predetermined depth, which is formed at a central portion of the second side surface 151b of the orbiting plate 151. As a discharge port 157 is eccentrically disposed from an axial center, the discharge guide groove 156 may also be eccentrically disposed from the axial center. The scroll-side sealing groove 155a may be provided on an inner circumferential surface of the discharge guide groove 156 in a stepped manner.

In addition, the discharge port 157 may be provided in the discharge guide groove 156. The discharge port 157 may penetrate between the first side surface 151a and the second side surface 151b of the orbiting end plate 151. An end portion of the discharge port 157 may be provided with a check valve 158 to open and close the discharge port 157, which acts as a kind of a discharge valve.

The orbiting end plate 151 may be provided with the oil guide passage 159 that guides oil introduced into the discharged oil storage space 122 of the rear housing 120 to an oil supply passage 165 of the rotating shaft 160, which will be described hereinafter.

Referring back to FIGS. 2 and 3, the rotating shaft 160 may be connected to the motor unit 130 and the orbiting scroll 150, respectively, so that a driving force generated in the motor unit 130 may be transferred to the orbiting scroll 150. To this end, the rotating shaft 160 may extend from the front to the rear of the motor-operated compressor 100. A direction to which the rotating shaft 160 extends may be an axial direction of the rotating shaft 160. The rotating shaft 160 may be insertedly fixed to the rotor 132 in a shrink-fitting manner (or hot press fitting).

The rotating shaft 160 may include a motor coupling portion 161, the main bearing portion 162, the sub bearing portion 163, and the eccentric portion 164.

The motor coupling portion 161 may be coupled through a center of the rotor 132.

The main bearing portion 162 may correspond to a rear side of the motor coupling portion 161, and the sub bearing portion 163 may correspond to a front side of the motor coupling portion 161. Accordingly, the main bearing portion 162 and the sub bearing portion 163 may axially extend from the motor coupling portion 161 to directions opposite from each other. Each of the main bearing portion 162 and the sub bearing portion 163 may have an outer diameter different from a diameter of the motor coupling portion 161. A center of the main bearing portion 162 and a center of the sub bearing portion 163 may coincide with a center of the motor coupling portion 161, respectively.

The main bearing portion 162 may be inserted to axially penetrate through the rotating shaft accommodating portion 147 of the fixed scroll 140 to be described hereinafter. The main bearing 171 implemented as a bush bearing may be coupled to the rotating shaft accommodating portion 147. Accordingly, the main bearing portion 162 may be radially supported by the main bearing 171 in a rotatable manner.

The sub bearing portion 163 may be coupled to the shaft support portion 113 provided at a front surface of the main housing 110. The sub-bearing 172 implemented as a ball bearing may be coupled to the shaft support portion 113. Accordingly, the sub bearing portion 163 may be radially and axially supported by the sub bearing 172 in a rotatable manner.

The eccentric portion 164 may be a portion that corresponds to a rear side of the main bearing portion 162. The eccentric portion 164 may axially extend from the main bearing portion 162. The eccentric portion 164 may have an outer diameter smaller than the outer diameter of the main bearing portion 162.

A center of the eccentric portion 164 may be eccentrically disposed with respect to the center of the main bearing portion 162. Referring to FIG. 4, a center Oe of the eccentric portion 164 may be eccentrically disposed from the center of the motor coupling portion 161 in the axial direction of the rotating shaft 160 or from an axial center Oc of the rotating shaft 160 which may be coaxial with the center of the motor coupling portion 161. The eccentric portion 164 may be formed at the rear end of the rotating shaft 160 to be inserted into the rotating shaft coupling portion 153 of the orbiting scroll 150.

The oil supply passage 165 may be provided in the rotating shaft 160 so as to guide oil introduced into the rotating shaft coupling portion 154 of the orbiting scroll 150 to the main bearing portion 162 and the eccentric portion 164. The oil supply passage 165 may include an oil supply groove 165a and a plurality of oil supply holes 165b and 165c.

Meanwhile, as described above, the casing according to this embodiment may be configured as the main housing 110 and the rear housing 120. The fixed scroll 140 provided between the main housing 110 and the rear housing 120 may be axially supported to be fixed.

FIG. 6 is a perspective view of a rear housing, viewed from the front, according to an embodiment of the present disclosure.

Referring to FIG. 6, the rear housing 120 may be coupled to the rear end of the main housing 110 while axially supporting the fixed scroll 140.

An inner space of the rear housing 120 may sequentially include the scroll accommodating portion 121, the discharged oil storage space 122, and the oil separation space 123 starting from the compression chamber V in a refrigerant flowing direction.

The scroll accommodating portion 121 and the discharged oil storage space 122 may be separated by the second scroll support portion 125 radially protruding from the inner circumferential surface of the rear housing 120. The second scroll support portion 125 may have an annular shape so that a front surface thereof forms the scroll accommodating portion 121 and the rear surface thereof forms the discharged oil storage space 122.

The second scroll support portion 125 may be integrally formed at the rear housing 120, and in some cases, it may be post-assembled. FIG. 3 is a view illustrating an example in which the second scroll support portion 125 integrally extends from the rear housing 120.

For example, when the second scroll support portion 125 is integrally formed with the rear housing 120, an inner diameter of the second scroll support portion 125 may be equal to an inner diameter of the discharged oil storage space 122. This may allow the second scroll support portion 125 located at the opened side of the rear housing 120 to be easily formed.

In this case, however, as a second sealing member 182 to be described hereinafter is installed at the second scroll support portion 125, the inner diameter of the second scroll support portion 125 may be smaller than an outer diameter of the orbiting end plate 151. As the inner diameter of the second scroll support portion 125 is decreased, the inner diameter of the discharged oil storage space 122 may be reduced accordingly. Then, a substantial volume of the discharged oil storage space 122 may be reduced. As a result, a noise reduction effect for a refrigerant discharged may be decreased, and an amount of discharged oil may be increased due to the reduced oil storage space.

Accordingly, as illustrated in FIG. 3, the second scroll support portion 125 may have the smaller inner diameter than the discharged oil storage space 122 even when the second scroll support portion 125 is integrally formed at the rear housing 120. Thus, the second scroll support portion 125 may be formed in a stepped manner from the discharged oil storage space 122 in a radial direction.

In addition, even when the second scroll support portion 125 is assembled to the rear housing 120, the inner diameter of the discharged oil storage space 122 may be smaller than an inner diameter of the scroll accommodating portion 121.

Further, when the second scroll support portion 125 is assembled to the rear housing 120, a rear surface of the second scroll support portion 125 may be axially supported by the rear housing 120, and thus the inner diameter of the discharged oil storage space 122 may be smaller than the inner diameter of the scroll accommodating portion 121.

When the second scroll support portion 125 is assembled to the rear housing 120, as described above, a support surface (not shown) of the rear housing 120 that supports the second scroll support portion 125 may be formed as small as possible to secure the inner diameter of the discharged oil storage space 122 as wide as possible.

The discharged oil storage space 122 may have a closed rear surface formed in a cylindrical shape. The oil separation space 123 may be provided at the rear surface of the discharged oil storage space 122. Accordingly, the rear surface of the discharged oil storage space 122 may slightly protrude forwardly to secure the oil separation space 123. A plurality of oil separation communication holes 122a and 122b may be provided on both upper and lower sides of the rear surface of the discharged oil storage space 122, so as to communicate with the oil separation space 123.

The oil separation communication hole formed at the upper side (hereinafter, “first oil separation communication hole”) 122a may be a hole that guides a refrigerant in the discharged oil storage space 122 to the oil separation space 123, and the oil separation communication hole formed at the lower side (hereinafter, “second oil separation communication hole”) 122b may be a hole that guides oil separated in the oil separation space 123 to the discharged oil storage space 122. Accordingly, the first oil separation communication hole 122a may communicate with a side surface of the oil separation space 123, and the second oil separation communication hole 122b may communicate with a bottom surface of the oil separation space 123.

The oil separation space 123 may be formed in a vertical direction or in a direction slightly inclined with respect to the vertical direction. The oil separator 123a may be installed at the oil separation space 123 so as to separate oil from a refrigerant introduced into the oil separation space 123. After separation, the refrigerant may flow into a refrigeration cycle via the exhaust port 126 formed through an upper end of the oil separation space 123, whereas the oil in a mist state may flow into the discharged oil storage space 124 through the second oil separation communication hole 122b formed though a lower end of the oil separation space 123.

The second scroll support portion 125 defining a front surface of the discharged oil storage space 122 may be provided with at least one oil return (or recovery) passage 127 that may guide oil in the discharged oil storage space 122 to the compression unit 105.

Meanwhile, a housing-side sealing groove 125a may be provided at the second scroll support portion 125, and a housing-side sealing member (hereinafter, “second sealing member”) 182 may be inserted into the housing-side sealing groove 125a. The second sealing member 182 together with the first sealing member 181 may seal between the discharged oil storage space 122 and the suction space (or compression chamber) S1. The second sealing member 182 may be provided with a second oil communication hole 182a communicating with the oil return passage 127 and a first oil communication hole 180b of the thrust plate 180, respectively, which will be described hereinafter.

The thrust plate 180 may be installed between the orbiting scroll 150 and the rear housing 120. The thrust plate 180 may be made of a material having higher wear resistance than the orbiting scroll 150 or the rear housing 120, since the thrust plate 180 may be installed to reduce friction loss and abrasion against the rear housing 120 while the orbiting scroll 150 is performing an orbiting motion.

In addition, the thrust plate 180 may have an annular shape. An outer circumferential portion of the thrust plate 180, which may be an edge (or circumference) of the thrust plate 180, may be fixedly coupled between the rear housing 120 and the fixed scroll 140, and an inner circumferential portion thereof, which may be a central portion of the thrust plate 180, may be disposed between the rear housing 120 and the orbiting scroll 150 in a free state. Accordingly, an outer diameter of the thrust plate 180 may be substantially equal to the inner diameter of the scroll accommodating portion 121 of the rear housing 120, and the inner diameter of the thrust plate 180 may be substantially equal to the inner diameter of the second scroll support portion 125 of the rear housing 120.

The thrust plate 180 may be provided with a plurality of pin holes 180a through which the thrust plate 180 can be coupled. The plurality of pin holes 180a may be formed along the circumferential direction with a predetermined distance therebetween. The pinhole 180a may be approximately equal to or slightly larger than the anti-rotation pin 192.

In addition, the first oil communication hole 180b may be provided in the thrust plate 180. The first oil communication hole 180b may be located between the second oil communication hole 182a of the second sealing member 182 and the oil guide passage 159 of the orbiting scroll 150. Accordingly, the second oil communication hole 182a and the oil guide passage 159 may communicate with each other via the oil communication hole 180b.

The motor-operated compressor according to this embodiment may operate as follows.

When power is applied to the drive motor 130, the rotating shaft 160 may transfer a rotational force to the orbiting scroll 150 while rotating together with the rotor 132. This may allow the orbiting scroll 150 to perform an orbiting motion with respect to the fixed scroll 140 by the anti-rotation ring 191 and the anti-rotation pin 192. Accordingly, the compression chamber V may be reduced in volume while continuously moving toward a central part.

Then, a refrigerant may flow into the motor chamber, which may be the suction space S1, through the inlet port 111, and may pass through a flow path provided between an outer circumferential surface of the stator 131 and the inner circumferential surface of the main housing 110, or an air gap between the stator 131 and the rotor 132, so as to be introduced into the compression chamber V.

Then, the refrigerant may be pressurized or compressed by the fixed scroll 140 and the orbiting scroll 150, and may then be discharged into the discharged oil storage space 122 through the discharge port 157. This refrigerant may flow from the discharged oil storage space 122 to the oil separation space 123 through the oil separation communication hole 122a, so that oil may be separated from the refrigerant. The refrigerant separated from the oil may be discharged into a refrigeration cycle through the exhaust port 126, whereas the oil in a mist state may flow into the discharged oil storage space 122 through the second oil separation communication hole 122b. This oil may then be introduced into each of bearing surfaces and the compression chambers through the oil return passage 127, the oil guide passage 159, and the oil supply passage 165. Such series of processes may be repeated.

Meanwhile, in the motor-operated compressor according to the present disclosure, an oil supply structure for guiding oil in the discharged oil storage space 122 to the compression unit 105 may be provided. The oil supply structure may include the oil return passage 127 of the rear housing 120, the second oil communication hole 182a of the second sealing member 182, the first oil communication hole 180b of the thrust plate 180, the oil guide passage 159 of the orbiting scroll 150, and the oil supply passage 165 of the rotating shaft 160. Hereinafter, this oil supply structure will be described according to flowing sequence of oil.

FIG. 7 is a cross-sectional view illustrating a portion of the motor-operated compressor for explaining one embodiment of an oil supply structure, and FIG. 8 is an enlarged cross-sectional view illustrating a portion “A” of FIG. 7.

Referring to FIGS. 7 and 8, as described above, the oil return passage 127 may be provided at the second scroll support portion 125 of the rear housing 120. The oil return passage 127 may be formed through the second scroll support portion 125 by penetrating from the rear surface to the front surface thereof. Accordingly, an inlet of the oil return passage 127 may be provided at the rear surface of the second scroll support portion 125, and an outlet of the oil return passage 127 may be provided at the front surface of the second scroll support portion 125.

It may be advantageous that the inlet of the oil return passage 127 is formed to be the lowest point or near the lowest point of the discharged oil storage space 122 as possible.

The outlet of the oil return passage 127 may communicate with an inside of the housing-side sealing groove 125a by axially penetrating a rear surface of the housing-side sealing groove 125a. Accordingly, an inner diameter of the oil return passage 127 may be lower than or equal to a height of the rear surface of the housing-side sealing groove 125a.

Here, the housing-side sealing groove 125a may have an annular shape formed at an edge of the front surface of the second scroll support portion 125. For example, the housing-side sealing groove 125a may be located radially outward than the scroll-side sealing groove 155a. The housing-side sealing groove 125a may be disposed outer than the oil guide passage 159 of the orbiting scroll 150, or may be formed at a position overlapping with the oil guide passage 159. In this embodiment, description will be focused on an example in which the housing-side sealing groove 125a is formed at the position overlapping with the oil guide passage 159.

It may also be advantageous that the outlet of the oil return passage 127 is formed through the lowest point or near the lowest point of the housing-side sealing groove 125a.

Meanwhile, the housing-side sealing member (second sealing member) 182 may be inserted into the housing-side sealing groove 125a. Accordingly, the second sealing member 182 may be lifted toward the front by pressure of oil introduced into the housing-side sealing groove 125a via the oil return passage 127 or by pressure of a refrigerant (or oil) introduced into the housing-side sealing grove 125a from the discharged oil storage space 122 through a gap between the rear housing 120 and the thrust plate 180, allowing the front surface of the second sealing member 182 to come into close contact with an edge of the rear surface of the thrust plate 180, thereby sealing between the rear housing 120 and the thrust plate 180. Then, as described above, the second sealing member 182 together with the first sealing member 181 may seal between the discharged oil storage space 122 and the suction space (or compression chamber) S1.

The second sealing member 182 may be provided with at least one second oil communication hole 182a that provides communication between the oil return passage 127 and the oil guide passage 159. Accordingly, oil introduced into the housing-side sealing groove 125a via the oil return passage 127 may flow into the oil guide passage 159 through the second oil communication hole 182a of the second sealing member 182.

As the orbiting scroll 150 may be a member that performs an orbiting motion, it may not be suitable to fix the second sealing member 182 and the thrust plate 180 to the orbiting scroll 150. Accordingly, the second sealing member 182 and the thrust plate 180 may be fixed to the rear housing 120, and the second oil communication hole 182a of the second sealing member 182 and the first oil communication hole 180b of the thrust plate 180 may be in communication with the oil guide passage 159 of the orbiting scroll 150 at all times.

For example, as shown in FIG. 8, an inner diameter D1 of the first guide passage 159a that defines the inlet of the oil guide passage 159 provided at the orbiting scroll 150 may be wider (or greater) than an inner diameter D2 of the first oil communication hole 180b provided at the thrust plate 180. For instance, the inner diameter D1 of the first guide passage 159a may be wider than the inner diameter D2 of the first oil communication hole 180b by about a turning radius (or turning circle). Accordingly, at least a portion or part of the inlet of the oil guide passage 159 and the first oil communication hole 180b may radially overlap with each other at all times. Further, the inner diameter D2 of the first oil communication hole 180b of the thrust plate 180 may be substantially equal to or slightly larger (or greater) than an inner diameter D3 of the second oil communication hole 182a of the second sealing member 182. The inner diameter D3 of the second oil communication hole 182a of the second sealing member 182 may be approximately equal to or slightly larger than an inner diameter D4 of the oil return passage 127. Accordingly, the inner diameter D2 of the first oil communication hole 180b may be substantially equal to or slightly larger than the inner diameter D4 of the oil return hole 127 as well as the inner diameter D3 of the second oil communication hole 182a.

Alternatively, the first oil communication hole 180b of the thrust plate 180 may be larger than the second oil communication hole 182a of the second sealing member 182, and be equal to the first guide passage 159a of the oil guide passage 159. However, in this case, the inner diameter D2 of the first oil communication hole 180b may be greater than a width D5 of the second sealing member 182. Then, the second sealing member 182 may not properly seal the discharged oil storage space 122, which may require another sealing member to be separately provided at an outside of the second sealing member 182. Therefore, the inner diameter D2 of the first oil communication hole 180b may be substantially equal to the inner diameter D3 of the second oil communication hole 182a.

Meanwhile, in order for the second oil communication hole 182a of the second sealing member 182 to be located between the oil return passage 127 and the oil guide passage 159, the second sealing member 182 may be fixed to the rear housing 120 with respect to the circumferential direction from the housing-side sealing groove 125a.

FIG. 9 is a planar view illustrating one embodiment of a fixing structure in which a second sealing member is fixed to the rear housing, and FIG. 10 is a cross-sectional view taken along line “VI-VI” of FIG. 9.

Referring to FIGS. 9 and 10, at least one pin hole 182b may be formed through the second sealing member 182 in the axial direction. At least one pin groove 182c may be provided at one side of the pin hole 182b in the radial direction. The pin groove 182c may be recessed from a surface that faces the housing-side sealing groove 125a of the rear housing 120 in the axial direction by a predetermined depth. Accordingly, the second sealing member 182 may be constrained to the rear housing 120 by using a fixing pin 195 fixed to the housing-side sealing groove 125a to be inserted into the pin groove 182c. Here, a fixing pin portion (not shown) may be integrally extended to the rear housing 120 to be coupled to the pin groove 182c of the second sealing member 182.

Even when the second sealing member 182 is coupled to the rear housing 120 to prevent rotation, as described above, the second sealing member 182 may be slidably coupled to the fixing pin 195 or the fixing pin portion, so as to be movably coupled to the rear housing 120 and the thrust plate 180 in the axial direction.

Meanwhile, when the second sealing member 182 inserted into the housing-side sealing groove 125a is pushed toward the thrust plate 180, a kind of oil passage having an annular shape may be formed between the second sealing member 182 and the housing-side sealing groove 125a. Then, the second oil communication hole 182a of the second sealing member 182 may communicate with the oil passage provided between the second sealing member 182 and the housing-side sealing groove 125a at all times. Accordingly, the second sealing member 182 may not necessarily be fixed to the housing-side sealing groove 125a in the circumferential direction.

However, when the second sealing member 182 rotates with respect to the rear housing 120, the second oil communication hole 182a may be axially misaligned with respect to the first oil communication hole 180b of the thrust plate 180, causing the oil passage to be blocked. Accordingly, the second sealing member 182 and the thrust plate 180 may be constrained with each other in the circumferential direction. As the thrust plate 180 is constrained between the rear housing 120 and the main housing 110, as described above, all of the rear housing 120, the second sealing member 182, and the thrust plate 180 may be constrained. Then, as described above, the oil return passage 127, the second oil communication hole 182a, and the first oil communication hole 180b may be kept aligned to communicate with each other at all times. Furthermore, the inlet of the oil guide hole 159 provided at the orbiting scroll 150 may be larger than an inner diameter of the first oil communication hole 180b so as to communicate with the oil guide hole 159, which allows the oil passage to be in an opened state at all times even if the orbiting scroll 150 performs an orbiting motion.

Meanwhile, as the thrust plate 180 is fixed between the rear housing 120 and the fixed scroll 140, the second sealing member 182 may be fixed to the thrust plate 180 instead of the rear housing 120.

FIG. 11 is a front view illustrating another embodiment of the fixing structure of the second sealing member in FIG. 7, and FIGS. 12 and 13 are cross-sectional views taken along line “VII-VII” of FIG. 11.

For example, as shown in FIGS. 11 and 12, the thrust plate 180 and the second sealing member 182 may be constrained to each other by the fixing pin 195 penetrating through the thrust plate 180 and the second sealing member 182. To this end, pin grooves 180c and 182c may be provided at the thrust plate 180 and the second sealing member 182, respectively, so that both ends of the fixing pin 195 may be coupled. Here, the thrust plate 180 may have a predetermined thickness so as to fix the second sealing member 182.

Alternatively, as shown in FIG. 13, a fixing pin portion 180d like a burr may be provided at the thrust plate 180. A front surface of the second sealing member 182 facing the thrust plate 180 may be provided with the pin groove 182c in which the fixing pin portion 180d is inserted.

However, the second sealing member 182 may be slidably coupled to the fixing pin 195 or the fixing pin portion 180d, so that the second sealing member 182 can be coupled to be axially movable with respect to the rear housing 120 and the thrust plate 180.

As such, the oil return passage 127 and the oil guide passage 159 may always be in an overlapped state by coupling the second sealing member 182 to the thrust plate 180 so as to prevent rotation.

Although not illustrated in the drawings, the oil return passage 127 and the oil guide passage 159 may communicate with each other at an inner side or outer side with respect to the second sealing member 182. Here, the second sealing member 182 may be coupled to an inside of the housing-side sealing groove 125a to move freely in the circumferential direction. In addition, a separate (or additional) sealing member other than the second sealing member 182 may be further provided between the rear housing 120 and the thrust plate 180, so as to seal inward (or inner side) and outward (or outer side), respectively, with respect to a passage that provides communication between the oil return passage 127 and the oil guide passage 159.

Meanwhile, the orbiting scroll 150 may be provided with the oil guide passage 159. The oil guide passage 159 may communicate with the oil return passage 127 of the rear housing 120 through the first oil communication hole 180b and the second oil communication hole 182a of the second sealing member 182.

Referring back to FIG. 7, the first guide passage 159a may be provided at an edge portion of the orbiting end plate 151, which may be recessed by a predetermined depth from the second-side surface 151b in the axial direction to define an inlet end of the oil guide passage 159. The orbiting end plate 151 may be provided therein with a second guide passage 159b that communicates with the first guide passage 159a and may be recessed by a predetermined depth in the radial direction. A third guide passage 159c penetrating from the second guide passage 159b to the first side surface 151a of the orbiting end plate 151 may be provided at the central portion of the orbiting end plate 151.

As described above, the first guide passage 159a may be wider than the first oil communication hole 180b. By doing so, the orbiting scroll 150 may perform an orbiting motion. Further, the first guide passage 159a and the first oil communication hole 180b may always radially overlap with each other while the thrust plate 180 is fixed.

The second guide passage 159b may be smaller than the first guide passage 159a. However, processing (or fabrication) may be difficult as the second guide passage 159b is longer than the first guide passage 159a. In order to solve this, a flow (or flow rate) controller 159d may be installed in the second guide passage 159b, when the second guide passage 159b is formed to have an inner diameter similar to an inner diameter of the first guide passage 159a. Then, high pressure oil in the discharged oil storage space 122 may be depressurized through the flow controller 159d to be introduced into the compression unit 105. The flow controller 159d may also be installed at the oil supply passage 165 of the rotating shaft 160 described hereinafter.

The flow controller 159d may control a flow rate of oil passing through the oil return passage 159, so that oil can be reduced to an intermediate pressure when the oil in the discharged oil storage space 122 is introduced into the compression unit 105. Accordingly, the flow controller 159d may be made of a pressure reducing member, such as a pressure reducing pin and a pressure reducing rod, having an outer diameter smaller than the inner diameter of the oil return passage 159.

The third guide passage 159c may penetrate through a rear wall surface of the rotating shaft coupling portion 153 to communicate with the rotating shaft coupling portion 153. However, the third guide passage 159c may not necessarily penetrate through the rear wall surface of the rotating shaft coupling portion 153. The third guide passage 159c may be formed through a front-end surface of the orbiting wrap 152, as necessary.

Meanwhile, the oil supply passage 165 may be provided at the rotating shaft 160. The oil supply passage 165 may include one oil supply groove 165a formed in the axial direction and the plurality of oil supply holes 165b and 165c formed in the radial direction.

The oil supply groove 165a may be configured as a groove recessed from the rear end of the rotating shaft 160 to a predetermined depth. The oil supply holes 165b and 165c may be implemented as a hole, each penetrating from the oil supply groove 165a to an outer circumferential surface of the rotating shaft 160, namely, to an outer circumferential surface of the main bearing portion 162 and an outer circumferential surface of the eccentric portion 164, respectively. The oil supply hole formed through the main bearing portion 162 may be referred to as ‘first oil supply hole’ 165b, and the oil supply hole formed through the eccentric portion 164 may be referred to as ‘second oil supply hole’ 165c.

The first oil supply hole 165b and the second oil supply hole 165c may have the same inner diameter and may penetrate in the same direction. In some cases, however, an inner diameter of the second oil supply hole 165c may be larger than an inner diameter of the first oil supply hole 165b. This may allow more oil to be supplied to the eccentric portion 164 than the main bearing portion 162. Thus, oil may be supplied to the compression chambers more quickly.

In the oil supply structure according to this embodiment, a process of oil flowing from the discharged oil storage space to the compression unit is as follows.

That is, as the discharged oil storage space 122 forms a discharge pressure, oil in the discharged oil storage space 122 may flow toward the compression unit 105 having a relatively low pressure. Accordingly, the oil in the discharged oil storage space 122 may flow into the housing-side sealing groove 125a through the oil return passage 127.

This oil may be introduced into the oil guide passage 159 of the orbiting scroll 150 via the first oil communication hole 180b of the thrust plate 180, and the second oil communication hole 182a of the second sealing member 182 that communicates with the housing-side sealing groove 125a.

As the second sealing member 182 is coupled to the thrust plate 180 or the rear housing 120 by the fixing pin 195, the second oil communication hole 182a of the second sealing member 182 may communicate with the first oil communication hole 180b of the thrust plate 180 at all times. Accordingly, oil in the oil return passage 127 may smoothly flow between the thrust plate 180 and the orbiting scroll 150 through the second oil communication hole 182a and the first oil communication hole 180b.

The first oil communication hole 180b of the thrust plate 180 may be misaligned with the oil guide passage 159 of the orbiting scroll 150 as the thrust plate 180 is fixed, whereas the orbiting scroll 150 performs an orbiting motion. However, as the inner diameter D1 of the first guide passage 159a defining the inlet of the oil guide passage 159 is wider (or greater) than the inner diameter D2 of the first oil communication hole 180b, the first oil communication hole 180b and the first guide passage 159a may always be overlapped with each other so as to communicate with each other. Accordingly, oil flowing between the thrust plate 180 and the orbiting scroll 150 may be smoothly introduced into the oil guide passage 159. As the oil return passage 127 is provided with the flow controller 159d made of a pressure reducing member, oil at high pressure may be reduced to an intermediate pressure.

Then, the oil may be introduced into the rotating shaft coupling portion 153 facing the rear end of the rotating shaft 160 through the oil guide passage 159, and may then be supplied to a bearing surface between the main bearing portion 162 of the rotating shaft 165 and the main bearing 171, and a bearing surface between the eccentric portion 164 of the rotating shaft 164 and an eccentric bearing 173 via the oil supply groove 165a provided at the rear end of the rotating shaft 165 and the respective oil supply holes 165b and 165c, thereby lubricating the respective bearing surfaces.

Then, the oil lubricating each of the bearing surfaces may be introduced into the compression chamber V while lubricating a lubricated surface between the fixed scroll 140 and the orbiting scroll 150 through a gap of the bearing surfaces. Such series of processes may be repeated.

Meanwhile, in the previous embodiment, the discharged oil storage space may include a discharge space and an oil storage space integrated into one. In some cases, however, the discharge space and the oil storage space may be provided, respectively. That is, the rear housing may include a scroll accommodating space, a discharge space, an oil separation space, and an oil storage space according to flowing sequence of a refrigerant.

Even in this case, a refrigerant and oil may flow in the same manner as in the case of the discharged oil storage space. However, providing the discharge space and the oil storage space separately may be more advantageous than integrating the discharge space and the oil storage space into one, in terms of an oil separation effect.

Hereinafter, description will be given of another embodiment of the motor-operated compressor according to the present disclosure.

That is, in the previous embodiment, the oil guide passage may be directly connected to the oil supply passage through the rotating shaft coupling portion. In this embodiment, however, the oil guide passage may be connected to the oil supply passage through the bearing surface.

FIG. 14 is a cross-sectional view illustrating another embodiment of the oil supply structure, and FIG. 15 is a cross-sectional view taken along line “VIII-VIII” of FIG. 14, illustrating an enlarged cross-section of a rotating shaft coupling portion.

Referring to FIG. 14, the oil return passage 127 may penetrate to the front surface of the second scroll support portion 125 from a position located more inwardly (central portion) than the housing-side sealing grove 125a. Accordingly, the first oil communication hole 180b may be provided at the thrust plate 180 so as to correspond to the oil return passage 127, and the oil guide passage 159 may be provided at the orbiting scroll 150 so as to correspond to the first oil communication hole 180b. As the orbiting scroll 150 performs an orbiting motion with respect to the thrust plate 180, the oil guide passage 159 may be larger than the inner diameter of the first oil communication hole 180b as in the previous embodiment.

An outlet end of the oil guide passage 159 may be formed through a cross section of the orbiting wrap 152 of the orbiting scroll 150. More precisely, referring to FIGS. 14 and 15, the outlet end of the oil guide passage 159 may be formed through the innermost side of the orbiting wrap 152, namely, the cross section of the orbiting wrap 152 defining the rotating shaft coupling portion 153.

In addition, the oil guide passage 159 may be provided with the flow controller 159d as in the previous embodiment. The flow rate controller may be installed at the oil supply passage of the rotating shaft.

When the oil guide passage 159 is formed through the cross section of the orbiting wrap 152, oil flowing from the discharged oil storage space 122 to the compression unit 105 through the oil return passage 127 and the first oil communication hole 180b may be introduced between the orbiting wrap 152 and the corresponding fixed end plate 141 of the fixed scroll 140. Then, this oil may flow toward a central portion together with a refrigerant to be compressed.

Thereafter, the oil may be introduced between the inner circumferential surface of the eccentric bearing 173 and the outer circumferential surface of the eccentric portion 164 to flow into a space between the rear end of the rotating shaft 160 and the rear surface of the rotating shaft coupling portion 153, and may then be introduced into the oil supply groove 165a provided at the rear end of the rotating shaft 160. This oil may lubricate each of the bearing surfaces through the respective oil supply holes 165b and 165c, and may then be reintroduced into the compression chamber V to be discharged through the discharge port 157 together with a refrigerant. Such series of processes may be repeated.

Here, a passage may be provided between the fixed scroll and the orbiting scroll, so that oil may smoothly flow toward the oil supply passage of the rotating shaft.

Referring to FIG. 15, an oil supply communication groove 153b may be provided at an end portion of the orbiting wrap 152 facing the fixed end plate 141, more precisely, at a front-end surface of the rotating shaft coupling portion 153 defining the orbiting wrap 152. The oil supply communication groove 153a may be recessed from the front-end surface of the rotating shaft coupling portion 153 by a predetermined depth, so as to communicate with an inner surface of the rotating shaft coupling portion 153. This may allow oil introduced via the oil guide passage 159 to smoothly flow into the rotating shaft coupling portion 153.

In addition, oil introduced between the end surface of the rotating shaft coupling portion and the fixed end plate via the oil guide passage may flow not only to the bearing surface between the eccentric bearing and the eccentric portion, but also to the bearing surface between the main bearing and the main bearing portion.

If more oil flows to the main bearing than the eccentric bearing due to a pressure difference, an amount of oil introduced into the oil supply passage may be reduced. FIG. 16 is a cross-sectional view comparing a gap of a main bearing with a gap of an eccentric bearing of FIG. 14.

Referring to FIG. 16, a second gap t2 between the inner circumferential surface of the eccentric bearing 173 and the outer circumferential surface of the eccentric portion 164 may be larger than a first gap t1 between the inner circumferential surface of the main bearing 171 and the outer circumferential surface of the main bearing portion 162, so that oil mainly flows to the eccentric bearing 173, namely, the rotating shaft coupling portion 153. This may allow the oil to smoothly flow into the oil supply passage 165.

In addition, an oil passage may be further provided at the eccentric portion 164 to allow oil to flow more smoothly toward the eccentric bearing 173. FIG. 17 is a cross-sectional view taken along line ““IX-IX” of FIG. 14, illustrating an oil passage provided on an outer circumferential surface of an eccentric portion.

Referring to FIG. 17, an oil communication groove 164a may be provided at the outer circumferential surface of the eccentric portion 164. The oil communication groove 164a may be formed by cutting the outer circumferential surface of the eccentric portion 164 into a D shape, so as to widen the gap between the inner circumferential surface of the eccentric bearing 173 and the outer circumferential surface of the eccentric portion 164, allowing an oil passage to be ensured.

As a result, the gap between the inner circumferential surface of the eccentric bearing 173 and the outer circumferential surface of the eccentric portion 164 may be further widened, so that oil may be more smoothly introduced into an inner space of the rotating shaft coupling portion 153.

A basic structure according to this embodiment may be similar to the previous embodiment, so a description thereof will be replaced with the description of the previous embodiment.

In a motor-operated compressor according to embodiments, a horizontal type motor-operated compressor that employs a frame scroll in which a frame and a fixed scroll are integrated can be provided.

In addition, in the motor-operated compressor according to embodiments, as a discharged oil storage space of a rear housing communicates with a compression unit having a relatively low pressure than the discharged oil storage space, oil accumulated in the discharged oil storage space can be quickly supplied to the compression unit due to a pressure difference. In addition, as a discharge space and an oil storage space are integrally formed at the rear housing, a volume of the oil storage space can be increased. Accordingly, oil moved to the compression unit can quickly flow to a bearing surface, thereby lubricating the bearing surface smoothly. Thus, friction loss or abrasion due to an insufficient amount of oil on the bearing surface can be reduced.

Further, in the motor-operated compressor according to embodiments, as an oil return passage and an oil guide passage are provided at the rear housing and an orbiting scroll, respectively, a simpler oil supply structure can be achieved, thereby reducing manufacturing costs for components including the rear housing. In addition, as the discharge space and the oil storage space are integrally formed at the rear housing, a manufacturing process of the rear housing can be further simplified.

Furthermore, in the motor-operated compressor according to embodiments, a flow controller is installed at the oil guide passage of the orbiting scroll or an oil supply passage of a rotating shaft, so that oil of a discharge pressure in the discharged oil storage space passes between the rear housing and the rotating scroll, allowing it to maintain at the discharge pressure. Accordingly, a number of sealing members provided between the rear housing and the orbiting scroll can be reduced, thereby lowering manufacturing costs. In addition, when an oil passage is formed through a sealing member, the number of sealing members can be further decreased, thereby reducing the manufacturing costs even further.

MOTOR-OPERATED COMPRESSOR

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CPC

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Priority Claims (1)