Patent ID: 12258966

DETAILED DESCRIPTION

Description will now be given of a concentric rotary compressor according to embodiments disclosed herein, with reference to the accompanying drawings. For reference, an oil supply hole according to embodiments may be equally applied to a concentric rotary compressor in which a vane is slidably inserted into the roller.

For example, the embodiments may be applied not only to an example in which the vane slot is inclined but also to an example in which the vane slot is formed radially. Hereinafter, an example in which a vane slot is inclined relative to a roller and an inner circumferential surface of a cylinder has an asymmetric elliptical shape will be described as a representative example.

In addition, the embodiments may be equally applied to a horizontal type in which a casing is parallel to an installation surface as well as a vertical type in which the casing is perpendicular to the installation surface as illustrated in an embodiment disclosed herein. Hereinafter, a vertical type compressor will be explained as a representative example.

FIG.1is a cross-sectional view of a concentric rotary compressor according to an embodiment.FIG.2is an exploded perspective view of a compression unit of the rotary compressor inFIG.1, andFIG.3is an assembled planar view of the compression unit inFIG.2.

Referring toFIG.1, a concentric rotary compressor according to an embodiment may include a casing110, a drive motor120, and a compression unit130. The drive motor120may be installed in an upper inner space110aof the casing110, and the compression unit130may be installed in a lower inner space110aof the casing110. The drive motor120and the compression unit130may be connected through a rotational shaft123.

The casing110defines an appearance of the compressor and may include an intermediate shell111having a cylindrical shape, a lower shell112that covers a lower end of the intermediate shell111, and an upper shell113that covers an upper end of the intermediate shell111. The drive motor120and the compression unit130may be inserted into the intermediate shell111to be fixed thereto, and a suction pipe115may penetrate through the intermediate shell111to be directly connected to the compression unit130. The lower shell112may be coupled to the lower end of the intermediate shell111in a sealing manner, and an oil storage space110bin which oil to be supplied to the compression unit130is stored may be formed below the compression unit130. The upper shell113may be coupled to the upper end of the intermediate shell111in a sealing manner, and an oil separation space110cmay be formed above the drive motor120to separate oil from refrigerant discharged from the compression unit130.

The drive motor120that constitutes a motor unit supplies power to cause the compression unit130to be driven. The drive motor120may include a stator121, a rotor122, and the rotational shaft123.

The stator121may be fixedly inserted into the casing110. The stator121may be fixed to an inner circumferential surface of the casing110in, for example, a shrink-fitting manner. For example, the stator121may be press-fitted into an inner circumferential surface of the intermediate shell111.

The rotor122may be rotatably inserted into the stator121, and the rotational shaft123may be press-fitted into a center of the rotor122. Accordingly, the rotational shaft123may rotate concentrically together with the rotor122.

An oil flow path125having a hollow hole shape may be formed in a central portion of the rotational shaft123, and oil passage holes126aand126bmay be formed through a middle portion of the oil flow path125toward an outer circumferential surface of the rotational shaft123. The oil passage holes126aand126bmay include first oil passage hole126abelonging to a range of a main bush portion1312described hereinafter and a second oil passage hole126bbelonging to a range of a second bearing portion1322. Each of the first oil passage hole126aand the second oil passage hole126bmay be provided as one or a plurality. In this embodiment, each of the first and second oil passage holes is provided as a plurality.

An oil pickup127may be installed at a middle or lower end of the oil passage125. A gear pump, a viscous pump, or a centrifugal pump may be used for the oil pickup127, for example. This embodiment illustrates a case in which the centrifugal pump is employed. Accordingly, when the rotational shaft123rotates, oil filled in the oil storage space110bis pumped by the oil pickup127and is suctioned along the oil flow path125, so as to be introduced to a sub bearing surface1322bof the sub bush portion1322through the second oil passage hole126band to a main bearing surface1312bof the main bush portion1312through the first oil passage hole126a.

The compression unit130may include a main bearing131, a sub bearing132, a cylinder133, a roller134, and a plurality of vanes1351,1352, and1353. The main bearing131and the sub bearing132may be respectively provided at upper and lower portions of the cylinder133to define a compression space V together with the cylinder133, the roller134may be rotatably installed in the compression space V, and the plurality of vanes1351,1352, and1353may be slidably inserted into the roller134to divide the compression space V into a plurality of compression chambers.

Referring toFIGS.1to3, the main bearing131may be fixedly installed in the intermediate shell111of the casing110. For example, the main bearing131may be inserted into the intermediate shell111and, for example, welded thereto.

The main bearing131may be coupled to an upper end of the cylinder133in a close contact manner. Accordingly, the main bearing131may define an upper surface of the compression space V, and support an upper surface of the roller134in an axial direction while supporting an upper-half portion of the rotational shaft123in a radial direction.

The main bearing131may include a main plate portion1311and a main bush portion1312. The main plate portion1311may cover an upper portion of the cylinder133to be coupled thereto, and the main bush portion1312may axially extend from a center of the main plate portion1311toward the drive motor120so as to support the upper portion of the rotational shaft123.

The main plate portion1311may have a disk shape, and an outer circumferential surface of the main plate portion1311may be fixed to the inner circumferential surface of the intermediate shell111in a close contact manner. One or more discharge ports1313a,1313bmay be formed in the main plate portion1311. A plurality of discharge valves1361,1362configured to open and close the respective discharge ports1313a,1313bmay be installed on an upper surface of the main plate portion1311. A discharge muffler137having a discharge space (no reference numeral) may be provided at an upper portion of the main plate portion1311to accommodate the discharge ports1313a,1313band the discharge valves1361,1362.

A first main back pressure pocket1315aand a second main back pressure pocket1315bmay be formed in a bearing surface (hereinafter, a main axial bearing surface)1311aof the main plate portion1311facing an upper surface of the roller134, of both axial side surfaces of the main plate portion1311. The first main back pressure pocket1315aand the second main back pressure pocket1315b, each having an arcuate shape, may be disposed at a predetermined interval in a circumferential direction. Each of the first main back pressure pocket1315aand the second main back pressure pocket1315bmay have an inner circumferential surface with a circular shape, but may have an outer circumferential surface with an oval or elliptical shape in consideration of vane slots described hereinafter.

The first main back pressure pocket1315aand the second main back pressure pocket1315bmay be formed within an outer diameter range of the roller134. Accordingly, the first main back pressure pocket1315aand the second main back pressure pocket1315bmay be separated from the compression space V. However, the first main back pressure pocket1315aand the second main back pressure pocket1315bmay slightly communicate with each other through a gap between a lower surface, a main axial bearing surface1311aof the main plate portion1311and the upper surface of the roller134facing each other unless a separate sealing member is provided therebetween.

The first main back pressure pocket1315aforms a pressure lower than a pressure formed in the second main back pressure pocket1315b, for example, forms an intermediate pressure between a suction pressure and a discharge pressure. Oil (refrigerant oil) may pass through a fine passage between a first main bearing protrusion1316adescribed hereinafter and the upper surface134aof the roller134so as to be introduced into the first main back pressure pocket1315a. The first main back pressure pocket1315amay be formed in the range of a compression chamber forming the intermediate pressure in the compression space V. This may allow the first main back pressure pocket1315ato maintain the intermediate pressure.

The second main back pressure pocket1315bmay form a pressure higher than that in the first main back pressure pocket1315a, for example, a discharge pressure or an intermediate pressure between a suction pressure close to the discharge pressure and the discharge pressure. Oil flowing into the main bearing hole1312aof the main bearing1312through the first oil passage hole126amay be introduced into the second main back pressure pocket1315b. The second main back pressure pocket1315bmay be formed in the range of a compression chamber forming a discharge pressure in the compression space V. This may allow the second main back pressure pocket1315bto maintain the discharge pressure. A first main bearing protrusion1316amay be formed on an inner circumferential side of the first main back pressure pocket1315ato extend from a main radial bearing surface1312bof the main bush portion1312. Accordingly, the first main back pressure pocket1315amay be sealed from outside and simultaneously the rotational shaft123may be stably supported.

An inner circumferential side of the second main back pressure pocket1315bmay be open without a separate bearing protrusion. Accordingly, the inner circumferential side of the second main back pressure pocket1315bmay be completely open toward the oil passage125, so that oil passing through the oil passage125may quickly flow into the second main back pressure pocket1315b, causing a fast increase in back pressure toward the vane1351,1352,1353.

Although not illustrated, a second main bearing protrusion1316bmay be formed on the inner circumferential side of the second main back pressure pocket1315bto extend from the main radial bearing surface1312bof the main bush portion1312. In this case, the rotational shaft123may be supported more stably by the first main bearing protrusion1316aand the second main bearing protrusion1316b.

Referring toFIGS.2and3, a vane support portion (hereinafter, main vane support protrusion)1317that supports an axial upper surface of the vane1351,1352,1353may be formed on one or a first end of the second main back pressure pocket1315b. For example, the main vane support protrusion1317may extend in a reciprocating direction of the vane1351,1352,1353from one or a first end, facing the contact point P1 in the circumferential direction, of both circumferential ends of the second main back pressure pocket1315b. Accordingly, an axial upper surface of the vane1351,1352,1353at a rear end, passing the contact point P1 and/or near the contact point P1, may be supported in the axial direction by the main vane support protrusion1317.

The main vane support protrusion1317may be formed such that an inner circumferential surface of the first side of the second main back pressure pocket1315bextends toward an inner circumferential surface of another or a second side of the second main back pressure pocket1315bfacing the first side. For example, the main vane support protrusion1317may be formed inside of the second main back pressure pocket1315band extend from the main axial bearing surface1311afacing the upper surface of the roller134. In other words, the main vane support protrusion1317may extend from the inner circumferential surface of the second main back pressure pocket1315b, to be located at a same height as the main axial bearing surface1311aof the main plate portion1311. Accordingly, a portion of the second main back pressure pocket1315bmay form the main axial bearing surface1311a, to expand a support area for an axial upper surface of the vane1351,1352,1353. With this structure, the main vane support protrusion1317may effectively suppress or prevent axial tilting of the vane1351,1352,1353that passes the contact point P1 and/or near the contact point P1. The main vane support protrusion1327will be described hereinafter together with a sub vane support protrusion1327described hereinafter.

In addition, an oil supply groove (hereinafter, referred to as main oil supply groove)1318may be formed in the main axial bearing surface1311aof the main plate portion1311, and at least a portion of the main oil supply groove1318may radially overlap the main vane support protrusion1317. For example, one or a first end of the main oil supply groove1318may communicate with the second main back pressure pocket1315b, and another or a second end of the main oil supply groove1318may extend to surround a radial outside of the second main back pressure pocket1315b. In this case, the second end of the main oil supply groove1318may extend in the circumferential direction to be closer to the contact point P1 than the second main back pressure pocket1315b. Accordingly, a portion of the main oil supply groove1318may overlap the main vane support protrusion1317in the radial direction, to provide lubrication between a bearing surface of the main vane support protrusion1317and the axial upper surface of the vane1351,1352,1353facing the bearing surface.

The main bush portion1312may be formed in a hollow bush shape, and a first oil groove1312cmay be formed in an inner circumferential surface of the main bearing hole1312athat defines an inner circumferential surface of the main bush portion1312. The first oil groove1312cmay be formed in a straight or inclined shape, for example, between upper and lower ends of the main bush portion1312to communicate with the first oil passage hole126a.

Referring toFIGS.1to3, the sub bearing132may be coupled to a lower end of the cylinder133in a close contact manner. Accordingly, the sub bearing132may define a lower surface of the compression space V, and support a lower surface of the roller134in the axial direction while supporting a lower-half portion of the rotational shaft123in the radial direction.

The sub bearing132may include a sub plate portion1321and the sub bush portion1322. The sub plate portion1321may cover a lower portion of the cylinder133to be coupled to thereto, and the sub bush portion1322may axially extend from a center of the sub plate portion1321toward the lower shell112so as to support the lower portion of the rotational shaft123. The sub plate portion1321may have a disk shape like the main plate portion1311, and an outer circumferential surface of the sub plate portion1321may be spaced apart from the inner circumferential surface of the intermediate shell111.

A first sub back pressure pocket1325aand a second sub back pressure pocket1325bmay be formed on a bearing surface (hereinafter, referred to as sub axial bearing surface)1321aof the sub plate portion1321, which faces the lower surface of the roller134, of both axial side surfaces of the sub plate portion1321. The first sub back pressure pocket1325aand the second sub back pressure pocket1325bmay be symmetrical to the first main back pressure pocket1315aand the second main back pressure pocket1315b, respectively, with respect to the roller134. For example, the first sub back pressure pocket1325aand the first main back pressure pocket1315amay be symmetrical to each other, and the second sub back pressure pocket1325band the second main back pressure pocket1315bmay be symmetrical to each other.

A first sub bearing protrusion1326amay be formed on an inner circumferential side of the first sub back pressure pocket1325a, and a second sub bearing protrusion1326bmay be formed on an inner circumferential side of the second sub back pressure pocket1325b. The first sub bearing protrusion1326aand the second sub bearing protrusion1326bmay have a same height or different heights.

For example, when the first sub bearing protrusion1326aand the second sub bearing protrusion1326bhave the same height, an oil communication groove (not illustrated) or an oil communication hole (not illustrated) may be formed on an end surface of the sub main bearing protrusion1316bsuch that inner and outer circumferential surfaces of the second sub bearing protrusion1326bmay communicate with each other. Accordingly, high-pressure oil (refrigerant oil) flowing into the sub radial bearing surface (no reference numeral) may be introduced into the second sub back pressure pocket1325bthrough the oil communication groove (not illustrated) or the oil communication hole (not illustrated).

On the other hand, when the first sub bearing protrusion1326aand the second sub bearing protrusion1326bhave different heights, the height of the second sub bearing protrusion1326bmay be lower than the height of the first sub bearing protrusion1326a. Accordingly, high-pressure oil (refrigerant oil) flowing into the sub bearing hole1322amay be introduced into the second sub back pressure pocket1325bby flowing over the second sub bearing protrusion1326b.

A description of the first sub back pressure pocket1325a, the second sub back pressure pocket1325b, and the first sub bearing protrusion1326amay be replaced with the description of the first main back pressure pocket1315b, the second main back pressure pocket1315b, and the first main bearing protrusion1316a. However, the second sub bearing protrusion1326bmay alternatively be formed stepwise on the inner circumferential side of the second sub back pressure pocket1325b. In this case, a radial support area of the rotational shaft123may be expanded to effectively suppress or prevent tilting of the rotational shaft123and simultaneously to suppress or prevent foreign substances mixed with oil from flowing through the second sub back pressure pocket1325b.

The first sub back pressure pocket1325aand the second sub back pressure pocket1325bmay be asymmetrical to the first main back pressure pocket1315aand the second main back pressure pocket1315b, respectively, with respect to the roller134. For example, the first sub back pressure pocket1325aand the second sub back pressure pocket1325bmay be formed to be deeper than the first main back pressure pocket1315aand the second main back pressure pocket1315b, respectively.

Referring toFIGS.1and3, a vane support portion (hereinafter, sub vane support protrusion)1327that supports the axial upper surface of the vane1351,1352,1353may be formed on one or a first end of the second sub back pressure pocket1325b. For example, the sub vane support protrusion1327may extend in a reciprocating direction of the vane1351,1352,1353from the first end facing the contact point P1 in the circumferential direction, of both circumferential ends of the second sub back pressure pocket1325b. Accordingly, the axial upper surface of the vane1351,1352,1353at the rear end, passing the contact point P1 and/or near the contact point P1, may be supported in the axial direction by the sub vane support protrusion1327.

The sub vane support protrusion1327may be formed such that an inner circumferential surface of one or a first side of the second sub back pressure pocket1325bextends toward an inner circumferential surface of another or a second side of the second sub back pressure pocket1325bfacing the first side. For example, the sub vane support protrusion1327may be formed inside of the second sub back pressure pocket1325band extend from the sub axial bearing surface1321afacing a lower surface of the roller134. In other words, the sub vane support protrusion1327may extend from the inner circumferential surface of the second sub back pressure pocket1325b, to be located at a same height as the sub axial bearing surface1321aof the sub plate portion1321. Accordingly, a portion of the second sub back pressure pocket1325bmay form the sub axial bearing surface1321a, to expand a support area for an axial lower surface of the vane1351,1352,1353. With this structure, the sub vane support protrusion1327may effectively suppress or prevent axial tilting of the vane1351,1352,1353that passes the contact point P1 and/or near the contact point P1. The sub vane support protrusion1327will be described hereinafter together with the main vane support protrusion1317.

In addition, an oil supply groove (hereinafter, referred to as sub oil supply groove)1328may be formed in the sub axial bearing surface1321aof the sub plate portion1321, and at least a portion of the sub oil supply groove1328may radially overlap the sub vane support protrusion1327. For example, one or a first end of the sub oil supply groove1328may communicate with the second sub back pressure pocket1325b, and another or a second end of the sub oil supply groove1328may extend to surround a radial outside of the second sub back pressure pocket1325b. In this case, the second end of the sub oil supply groove1328may extend in the circumferential direction to be closer to the contact point P1 than the second sub back pressure pocket1325b. Accordingly, a portion of the sub oil supply groove1328may overlap the sub vane support protrusion1327in the radial direction, to provide lubrication between the bearing surface of the sub vane support protrusion1327and the axial lower surface of the vane1351,1352,1353facing the bearing surface.

The sub bush portion1322may be formed in a hollow bush shape, and an oil groove1322cmay be formed in an inner circumferential surface of the sub bearing hole1322athat defines an inner circumferential surface of the sub bush portion1322. The oil groove1322cmay be formed, for example, in a linear or inclined shape between upper and lower ends of the sub bush portion1322to communicate with the second oil passage hole126bof the rotational shaft123.

Although not illustrated in the drawings, the back pressure pocket1325a,1325bmay be disposed only in any one of the main bearing131or the sub bearing132. Even in this case, the vane support protrusion1317,1327, which will be described hereinafter, may be formed only in a bearing in which the back pressure pocket1315b,1325bis formed.

Referring toFIGS.1to3, the cylinder133according to an embodiment may be in close contact with the main axial bearing surface1311aof the main bearing131and the sub axial bearing surface1321aof the sub bearing132and coupled by, for example, bolts to the main bearing131together with the sub bearing131. Accordingly, the cylinder133may be fixedly coupled to the casing110by the main bearing131.

The cylinder133may be formed in an annular shape having a hollow space in its center to define the compression space V. The hollow space may be sealed by the main bearing131and the sub bearing132to define the compression space V, and the roller134described hereinafter may be rotatably coupled to the compression space V.

The cylinder133may be provided with a suction port1331that penetrates from an outer circumferential surface to an inner circumferential surface thereof. However, the suction port1331may alternatively be formed through the main bearing131or the sub bearing132.

The suction port1331may be formed at one or a first side of the contact point P1 described hereinafter in the circumferential direction. The discharge port1313described above may be formed through the main bearing131at another or a second side of the contact point P1 in the circumferential direction which is opposite to the suction port1331.

The inner circumferential surface of the cylinder133may be formed in an elliptical shape. The inner circumferential surface of the cylinder133according to an embodiment may be formed in an asymmetric elliptical shape in which a plurality of ellipses, for example, four ellipses having different major and minor ratios are combined to have two origins.

Referring toFIGS.1to3, the roller134may be rotatably disposed in the compression space V of the cylinder133, and the plurality of vanes1351,1352,1353described hereinafter may be inserted in the roller134at preset or predetermined gaps along the circumferential direction. Accordingly, the compression space V may be partitioned into as many compression chambers as the number of the plurality of vanes1351,1352, and1353. This embodiment illustrates an example in which the plurality of vanes1351,1352, and1353includes three vanes, and thus, the compression space V is partitioned into three compression chambers V1, V2, and V3.

The outer circumferential surface of the roller134according to this embodiment may be formed in a circular shape, and the rotational shaft123may extend as a single body from or may be post-assembled and coupled to a rotational center Or of the roller134. Accordingly, the rotational center Or of the roller134is coaxially located with an axial center (no reference numeral) of the rotational shaft123, and the roller134rotates concentrically with the rotational shaft123.

However, as described above, as an inner circumferential surface of the cylinder133is formed in an asymmetric elliptical shape biased in a specific direction, the rotational center Or of the roller134may be eccentrically disposed with respect to an outer diameter center of the cylinder133. Accordingly, one or a first side of an outer circumferential surface of the roller134may be almost brought into contact with the inner circumferential surface of the cylinder133, thereby defining the contact point P1.

In addition, the plurality of vane slots1341a,1341b, and1341cmay be formed in the outer circumferential surface of the roller134to be spaced apart from each other in the circumferential direction. The plurality of vanes1351,1352, and1353described hereinafter may be slidably inserted into the plurality of vane slots1341a,1341b, and1341c, respectively.

The plurality of vane slots1341a,1341b, and1341cmay be defined as first vane slot1341a, second vane slot1341b, and third vane slot1341calong a compression-proceeding direction (a rotational direction of the roller). The first vane slot1341a, the second vane slot1341b, and the third vane slot1341cmay be formed in the same manner at equal or unequal intervals along the circumferential direction.

For example, each of the vane slots1341a,1341b, and1341cmay be inclined by a preset or predetermined angle with respect to the radial direction, so as to secure a sufficient length of each of the vanes1351,1352, and1353. Accordingly, when the inner circumferential surface of the cylinder133is formed in the asymmetric elliptical shape, separation of the vanes1351,1352, and1353from the vane slots1341a,1341b, and1341cmay be suppressed or prevented even if a distance from the outer circumferential surface of the roller134to the inner circumferential surface of the cylinder133increases. This may result in enhancing freedom of design for the inner circumferential surface1332of the cylinder133.

A direction in which the vane slots1341a,1341b, and1341care inclined may be a reverse direction to the rotational direction of the roller134. That is, front end surfaces of the vanes1351,1352, and1353in contact with the inner circumferential surface of the cylinder133may extend in the rotational direction of the roller134. This may be advantageous in that a compression start angle may be formed ahead in the rotational direction of the roller134so that compression may start quickly.

The back pressure chambers1342a,1342b, and1342cmay be configured to communicate with inner ends of the vane slots1341a,1341b, and1341c, respectively. The back pressure chambers1342a,1342b, and1342cmay be spaces in which oil (or refrigerant) of discharge pressure or intermediate pressure is filled to flow toward rear sides of the vanes1351,1352, and1353, that is, vane rear end portions1351c,1352c, and1353c. The vanes1351,1352, and1353may be pressed toward the inner circumferential surface of the cylinder133by the pressure of the oil (or refrigerant) filled in the back pressure chambers1342a,1342b, and1342c. For convenience, hereinafter, a direction toward the cylinder133based on a movement direction of the vanes1351,1352, and1353may be defined as a front side and an opposite side as a rear side.

The back pressure chamber1342a,1342b,1342cmay be hermetically sealed by the main bearing131and the sub bearing132. The back pressure chambers1342a,1342b, and1342cmay independently communicate with each of the back pressure pockets [1315a, and1315b], [1325a, and1325b], and may also communicate with each other through the back pressure pockets [1315a, and1315b], and [1325a, and1325b]

Referring toFIGS.1to3, the plurality of vanes1351,1352, and1353according to this embodiment may be slidably inserted into the respective vane slots1341a,1341b, and1341c. Accordingly, the plurality of vanes1351,1352, and1353may have substantially a same shape as the respective vane slots1341a,1341b, and1341c.

For example, the plurality of vanes1351,1352, and1353may be defined as first vane1351, second vane1352, and third vane1353along the rotational direction of the roller134. The first vane1351may be inserted into the first vane slot1341a, the second vane1352may be inserted into the second vane slot1341b, and the third vane1353may be inserted into the third vane slot1341c, respectively.

The plurality of vanes1351,1352, and1353may have substantially a same shape. More specifically, each of the plurality of vanes1351,1352, and1353may be formed substantially in a rectangular parallelepiped shape. The front end surface1351a,1352a,1353ain contact with the inner circumferential surface of the cylinder133may be formed as a curved surface and the rear end surface1351b,1352b,1353bfacing the back pressure chamber1342a,1342b,1342cmay be formed as a linear surface.

Additionally, oil supply guide grooves1351c,1352c,1353cthat extend along a longitudinal direction may be formed in both axial side surfaces of the vane1351,1352,1353. For example, the oil supply guide grooves1351c,1352c,1353cmay extend from a rear end to a front end of the vane1351,1352,1353by a preset or predetermined length. In other words, the oil supply guide grooves1351c,1352c,1353cmay be formed so that at least portions thereof communicate with the back pressure pockets1315b,1325b, respectively, without overlapping the vane support protrusions1317,1327. Accordingly, oil in the back pressure pockets1315b,1325bmay be supplied to the axial bearing surfaces1311a,1321abetween the vane1351,1352,1353and the vane support protrusions1317,1327through the oil supply guide grooves1351c,1352c,1353c. With this structure, even if a contact area between the vane support protrusions1317and1327and the axial bearing surfaces1311aand1321afacing them increases, friction loss and wear between the vane1351,1352,1353and the axial bearing surfaces1311aand1321amay be effectively suppressed or prevented.

Hereinafter, operation of the concentric rotary compressor with the hybrid cylinder will be described.

That is, when power is applied to the drive motor120, the rotor122of the drive motor120and the rotational shaft123coupled to the rotor122rotate together, causing the roller134coupled to the rotational shaft123or integrally formed therewith to rotate together with the rotational shaft123. Then, the plurality of vanes1351,1352, and1353may be drawn out of the vane slots1341a,1341b, and1341cby centrifugal force generated by the rotation of the roller134and back pressure of the back pressure chambers1342a,1342b, and1342c, which support the rear end surfaces1351b,1353b,1353bof the vanes1351,1352, and1353, thereby being brought into contact with the inner circumferential surface of the cylinder133.

The compression space V of the cylinder133may be partitioned by the plurality of vanes1351,1352, and1353into as many compression chambers (including a suction chamber or a discharge chamber) V1, V2, and V3 as the number of the vanes1351,1352, and1353. The compression chambers V1, V2, and V3 may be changed in volume by the shape of the inner circumferential surface of the cylinder133and eccentricity of the roller134while moving in response to the rotation of the roller134. Accordingly, refrigerant suctioned into the respective compression chambers V1, V2, and V3 may be compressed while moving along the roller134and the vanes1351,1352, and1353, and discharged into the inner space of the casing110. Such series of processes are repeatedly carried out.

As described above, in the rotary compressor according to the embodiment, the main back pressure pocket1315a,1315band the sub back pressure pocket1325a,1325bmay be formed on the main bearing and sub bearing, respectively, to axially overlap each vane1351,1352,1353. This decreases the axial support area for the rear end side of the vane1351,1352,1353. As a result, axial behavior of the vane1351,1352, and1353becomes unstable and the vane tilts. This causes friction loss and wear between axial side surfaces of the vane1351,1352,1353, and the main axial bearing surface1311aand/or the sub axial bearing surface1321afacing the axial side surfaces, thereby increasing vibration noise and lowering compression efficiency. This may occur particularly at the contact point P1 and/or near the contact point P1 where the vane1351,1352,1353is subject to a high gas force, for example, between the contact point P1 and the suction port1331.

Accordingly, in this embodiment, the vane support protrusion may be formed to extend inside of the back pressure pocket to support the vane in the axial direction, to secure a wide vane support area. This may stabilize the axial behavior of the vane to suppress or prevent friction loss and/or wear between the axial side surface of the vane and the main axial bearing surface and/or the sub axial bearing surface. Hereinafter, description will be focused on an example in which the vane support protrusions are formed on the main bearing and the sub bearing, respectively. The main vane support protrusion disposed on the main bearing will be described mainly and the sub vane support protrusion disposed on the sub bearing will be briefly described with reference to the description of the main vane support protrusion.

FIG.4is a perspective view of a main bearing and a sub bearing each having a vane support protrusion according to an embodiment.FIG.5is a planar view of the main bearing inFIG.4.FIG.6is a planar view of the sub bearing inFIG.4.FIG.7is a schematic view for explaining an effect of the vane support protrusion according to an embodiment.FIG.8is a cross-sectional view, taken along the “VIII-VIII” ofFIG.7.FIG.9is a cross-sectional view of a variation for the vane support protrusion ofFIG.7.

Referring back toFIGS.1and3, the main bearing131according to this embodiment may include the main plate portion1311and the main bush portion1312as described above. The main plate portion1311may be formed in an annular disc shape, and the main bush portion1312may be formed in a cylindrical shape extending from a central area of the main plate portion1311toward the drive motor120.

The first main back pressure pocket1315aand the second main back pressure pocket1315bhaving different pressures may be formed, as described above, on one side surface of the main plate portion1311, that is, the main axial bearing surface1311afacing the roller134. In other words, the first main back pressure pocket1315aand the second main back pressure pocket1315bmay be formed in an arcuate shape with a preset or predetermined gap therebetween along the circumferential direction, but may be located on a virtual circle C connecting the respective back pressure chambers1342a,1342b,1342c. Accordingly, the first main back pressure pocket1315amay communicate with the first sub back pressure pocket1325athrough each back pressure chamber1342a,1342b,1342c, and the second main back pressure pocket1315bmay communicate with the second sub back pressure pocket1325bthrough each back pressure chamber1342a,1342b,1342c.

Referring toFIGS.4and5, at least one of the first main back pressure pockets1315aor the second main back pressure pocket1315bmay include the vane support protrusion1317that supports the vane1351,1352,1353passing through the corresponding back pressure pocket in the axial direction. In this embodiment, description will focus on an example in which the vane support protrusion1317is formed in the second main back pressure pocket1315badjacent to the contact point P1.

Referring toFIG.5, the second main back pressure pocket1315bmay be formed in an approximately arcuate shape when projected in the axial direction, and may be recessed by a preset or predetermined depth into the main axial bearing surface1311aforming one axial side surface of the main plate portion1311. In other words, the inner circumferential surface of the second main back pressure pocket1315bmay include an inner wall surface1315c, an outer wall surface1315d, and a first side wall surface1315eand a second side wall surface1315fthat connect ends of the inner wall surface1315cand the outer wall surface1315din the circumferential direction, and the inner wall surface1315cand the outer wall surface1315dmay each be formed in an arcuate shape. Accordingly, the second main back pressure packet1315bmay generally have a cross-section in an arcuate shape.

However, the inner wall surface1315cmay be open toward the outer circumferential surface of the rotational shaft123, while the outer wall surface1315dand both side wall surfaces may be closed toward the inner circumferential surface of the cylinder133. In other words, the second main back pressure pocket stores oil in a space defined by the outer wall surface1315dand both the side wall surfaces even if the inner wall surface1315cis open. Accordingly, the inner wall surface1315cof the second main back pressure pocket is open and does not actually form a wall surface, but hereinafter, an open portion radially facing the outer wall surface1315dis defined as the inner wall surface1315c.

As described above, the inner wall surface1315cof the second main back pressure pocket1315bis a surface where the second main back pressure pocket1315bis open toward the inner circumferential surface of the rotational shaft123, and thus, has a same curvature as the main radial bearing surface1312aon a same axial line as a roller center Or. Accordingly, an inlet of the second main back pressure pocket1315bmay be completely open toward the oil passage125(more specifically, the first oil passage hole) of the rotational shaft123, enabling quick and smooth flow of oil into the second main back pressure pocket1315b.

Although not illustrated, a second main bearing support protrusion (not illustrated) forming the inner wall surface1315cmay be formed to protrude in the axial direction from the inner circumferential surface of the second main back pressure pocket1315b. In this case, the second main bearing support protrusion may be formed lower than the main axial bearing surface1311ato secure an inlet area of the second main back pressure pocket1315b.

The outer wall surface1315dof the second main back pressure pocket1315bmay be formed eccentrically with respect to the center of the main radial bearing surface1312a, that is, the roller center Or. In other words, the outer wall surface1315dof the second main back pressure pocket1315bmay be formed such that its center is eccentric away from the contact point P1 with respect to a center of the inner wall surface1315c, which is concentric with the main radial bearing surface1312a. Accordingly, the outer wall surface1315dof the second main back pressure pocket1315bmay be spaced apart from the inner circumferential surface of the cylinder133approximately by the same gap, while getting closer toward the contact point P1 from the inner wall surface1315cof the second main back pressure pocket1315b.

The first side wall surface1315eof the second main back pressure pocket1315bmay be a surface defining one or a first side surface in the circumferential direction, which is far away from the contact point P1, and may be formed as a flat (linear, straight) surface extending in the radial direction. Accordingly, the first side wall surface1315eof the second main back pressure pocket1315bmay be spaced apart from the neighboring first main back pressure pocket1315aby the same gap in the radial direction and secure a volume of the second main back pressure pocket1315bas wide as possible.

The second side wall surface1315fof the second main back pressure pocket1315bmay be a surface defining another or a second side surface in the circumferential direction, which is close to the contact point P1, and may be formed as an arcuate surface with a preset or predetermined curvature or as a linear surface. This embodiment will be described focusing on an example in which the second side wall surface1315fof the second main back pressure pocket1315bis formed as an arcuate surface.

For example, the second side wall surface1315fof the second main back pressure pocket1315bmay connect an end of the inner wall surface1315cclose to the contact point P1 and an end of the outer wall surface1315dclose to the contact point P1, and the inner circumferential surface of the main vane support protrusion1317formed in an area where the outer wall surface1315dand the second side wall surface1315fof the second main back pressure pocket1315bmeet may be formed as a curved surface having a second curvature R2. In other words, the second curvature R2 formed by the inner circumferential surface of the main vane support protrusion1317may be different from a first curvature R1 formed by the outer wall surface1315dof the second main back pressure pocket1315b.

More specifically, a center of the second curvature R2 formed by the inner circumferential surface of the main vane support protrusion1317may be spaced apart from a center of the first curvature R1 formed by the outer wall surface1315dof the second main back pressure pocket1315b, and the second curvature R2 may be larger than the first curvature R1. Accordingly, the main vane support protrusion1317may extend in a direction toward a geometric center of the second main back pressure pocket1315b, for example, along the reciprocating direction of the vane1351,1352,1353, thereby increasing the main axial bearing surface1311a.

In other words, the main vane support protrusion1317may be formed as the second side wall surface1315fand the outer wall surface1315dof the second main back pressure pocket1315bextend toward the inner wall surface1315calong the reciprocating direction of the vane1351,1352,1353. The main vane support protrusion1317may protrude in the axial direction from a bottom surface of the second main back pressure pocket1315band extend at the main axial bearing surface1311a. Accordingly, a circumferential gap G1 between the first main back pressure pocket1315aand the second main back pressure pocket1315bmay be gradually decreased from the outer wall surface1315dtoward the inner wall surface1315c. In other words, a radial gap G2 between the inner wall surface1315cand the outer wall surface1315dof the first main back pressure pocket1315a(and the second main back pressure pocket1315b) may be gradually decreased toward the contact point P1. With this structure, the main vane support protrusion1317may be formed to correspond to a movement path of the vane1351,1352,1353, thereby stably supporting the rear end of the vane. In other words, an area of the main axial bearing surface1311abetween the first main back pressure pocket1315aand the second main back pressure pocket1315bformed near the contact point P1 may be increased, to thus effectively suppress or prevent axial tilting of the vane1351,1352,1353passing the contact point P1.

In this case, as illustrated inFIG.7, a shortest distance L1 from the contact point P1 to the main vane support protrusion1317may be formed to be 0.7 to 0.9 times a length L2 of the vane1351,1352,1353. This may secure a substantial axial support area for the rear end of the vane1351,1352,1353at the contact point P1 and/or in the vicinity of the contact point P1.

In addition, the main vane support protrusion1317according to this embodiment may be formed so that its arcuate length L31 is smaller than or equal to an arcuate length L4 of the outer wall surface1315dof the second main back pressure pocket1315b. This may result in securing an axial support area for the vane1351,1352,1353passing near the contact point P1 and prevent a volume of the second main back pressure pocket1315bfrom being excessively reduced.

In other words, the main vane support protrusion1317may be formed so that at least a portion thereof is located in a discharge section S1of the compression chamber. For example, as illustrated inFIG.7, the main vane support protrusion1317may be formed to overlap the discharge section of the compression chamber, but the arcuate length L31 of the main vane support protrusion1317may be shorter than a length of the discharge section S1. Accordingly, an excessive increase in the area of the axial bearing surface1311afor the vane1351,1352,1353located far from the contact point P1 may be suppressed or prevented, thereby reducing friction loss that may be unnecessarily caused.

Also, the main vane support protrusion1317according to an embodiment may be formed at a same height as the main axial bearing surface1311a. For example, as illustrated inFIG.8, the main vane support protrusion1317may be formed to be flush with the main axial bearing surface1311a. Accordingly, the axial support area for the vane1351,1352,1353passing near the contact point P1 may be expanded by the area of the main vane support protrusion1317, so that the vane1351,1352,1353passing near the contact point P1 may be supported stably.

However, in some cases, the main vane support protrusion1317according to an embodiment may be formed at a different height from the main axial bearing surface1311a. For example, as illustrated inFIG.9, the main vane support protrusion1317may be formed stepwise to be lower than the main axial bearing surface1311a. Accordingly, oil in the second main back pressure pocket1315bmay be filled between the upper surface of the main vane support protrusion1317and the lower surface of the corresponding vane1351,1352,1353facing it, to improve a lubricating effect for the vane1351,1352,1353that passes the contact point P1.

Referring toFIGS.4and6, the vane support protrusion may be formed in the same way on the sub bearing132. In other words, the vane support protrusion (hereinafter, referred to as ‘sub vane support protrusion’)1327may extend in the axial direction from a bottom surface of the second sub back pressure pocket1325b. The sub vane support protrusion1327may laterally extend from the inner circumferential surface of the second sub back pressure pocket1325d(for example, an area where the second side wall surface and the outer wall surface meet) along the reciprocating direction of the vane1351,1352,1353. In this case, the sub vane support protrusion1327may be formed symmetrically to the main vane support protrusion1317of the main bearing131described above. Accordingly, description of the sub vane support protrusion1327will be replaced by the explanation of the main vane support protrusion1317.

However, the second sub bearing protrusion1326bmay protrude from the sub bearing132by a preset or predetermined height, to be lower than the sub axial bearing surface1321a. Accordingly, as the inner wall surface (no reference numeral) of the second sub back pressure pocket1325bprotrudes by the preset height, foreign substances introduced into the second sub back pressure pocket1325bmay be prevented from escaping to the bearing surface.

Additionally, the previously described vane support protrusion may be formed only on the sub bearing132. In other words, the main vane support protrusion (not illustrated) may be excluded and only the sub vane support protrusion1327may be formed. Even in this case, the sub vane support protrusion1327may be formed to be the same as the main vane support protrusion1317described above. Accordingly, description of the sub vane support protrusion1327will also be replaced by the explanation of the main vane support protrusion1317.

In this way, in the rotary compressor according to an embodiment, the support area for the axial side surface of the vane may be increased by forming the vane support protrusion on the main bearing and/or sub bearing. Accordingly, the vane may be prevented from tilting in the axial direction during operation so as to suppress or prevent wear of the axial bearing surface of the main bearing, the axial bearing surface of the sub bearing, the inner circumferential surface of the cylinder, and/or the front end surface of the vane. This may reduce vibration noise in a specific area and also suppress or prevent leakage between compression chambers, thereby enhancing compression efficiency. In addition, tilting of the vane which may occur more severely at the beginning of operation of the compressor may be effectively suppressed or prevented, thereby preventing a defective initial startup. In addition, when it is applied to an air conditioning device, air-conditioning effects may be quickly exhibited.

In addition, in the rotary compressor according to an embodiment, the oil supply groove may be formed in the main bearing and/or the sub bearing to overlap the vane support protrusion or the oil supply guide groove may be formed in the axial side surface of the vane, thereby increasing the support area between the vane and the axial bearing surface and suppressing friction loss and/or wear between the vane and the axial bearing surface.

The effects described above may be further expected in the rotary compressor according to the embodiment when a high-pressure refrigerant, such as R32, R410a, or CO2is used.

Hereinafter, description will be given of a vane support protrusion according to another embodiment. That is, in the previous embodiment, the vane support protrusion extends from the inner circumferential surface of the back pressure pocket along the reciprocating direction of the vane, but in some cases, the vane support protrusion may be formed to protrude from the back pressure pocket in the axial direction.

FIG.10is a perspective view illustrating a main bearing and a sub-bearing each having a vane support protrusion according to another embodiment.FIG.11is a planar view illustrating the main bearing inFIG.10.FIG.12is a planar view illustrating the sub bearing inFIG.10.FIG.13is a schematic view for explaining an effect of the vane support protrusion inFIG.10, andFIG.14is a cross-sectional view, taken along line “XIV-XIV” ofFIG.13.

Referring toFIGS.10to14, as the basic configuration and operating effects of the vane rotary compressor according to this embodiment are almost the same as those of the previous embodiment, detailed description thereof will be replaced by the description of the previous embodiment. For example, at least one vane slot1341a,1341b,1341cmay be formed in the roller134eccentrically inserted into the cylinder133, and the vane1351,1352,1353may be slid into the vane slot1341a,1341b,1341c. The vane1351,1352,1353may be axially supported by the main bearing131and the sub bearing132, which are coupled to the both axial sides of the cylinder133. The back pressure pockets [1315aand1315b], [1325aand1325b] communicating with the oil passage125of the rotational shaft123may be formed in at least one of the main bearing131or the sub bearing132. The back pressure pockets [1315aand1315b], [1325aand1325b] may communicate with the back pressure chamber1342a,1342b,1342cdisposed inside of the vane slot1341a,1341b,1341c. Accordingly, high-pressure oil may be introduced into the back pressure chamber1342a,1342b,1342cthrough the oil passage125of the rotational shaft123and the back pressure pockets [1315aand1315b], [1325aand1325b] to press the vane1351,1352,1353toward the inner circumferential surface of the cylinder133, thereby suppressing or preventing the vane1351,1352,1353from wobbling (forward and backward wobble).

However, as described above, the back pressure pockets [1315aand1315b], [1325aand1325b] are recessed axially into the main axial bearing surface1311aof the main bearing131and/or the sub axial bearing surface1321aof the sub bearing132, which results in reducing the axial support area for the vane1351,1352,1353. Due to this, the axial support force for supporting the vane1351,1352,1353may be reduced, thereby causing axial tilting of the vane1351,1352,1353. Especially, the vane1351,1352,1353that passes near the contact point P1 may behave unstably due to a gas repulsive force applied from the compression chamber, which may further aggravate the axial tilting of the vane1351,1352,1353near the contact point P1.

Accordingly, in this embodiment, the vane support protrusion extends from the main axial bearing surface1311aand/or the sub axial bearing surface1321anear the contact point P1, as in the previous embodiment. According to this embodiment, the vane support protrusion may be formed outside of the back pressure pockets [1315aand1315b], [1325aand1325b], so as to increase the axial support area for axially supporting the vane1351,1352,1353, and simultaneously suppress reduction of the volume of the back pressure pockets [1315aand1315b], [1325aand1325b]. The vane support protrusion may be formed on at least one of the main bearing131or the sub bearing132, but in this embodiment, an example in which the vane support protrusion is formed adjacent to the second main back pressure pocket1315bof the main bearing131, as in the previous embodiment, will be described.

Referring toFIGS.10and11, the main plate portion1311of the main bearing131according to this embodiment may include, as described above, the first main back pressure pocket1315aand the second main back pressure pocket1315bformed along the circumferential direction to be spaced apart from each other by a preset or predetermined gap. A first main bearing protrusion1316amay be formed on the inner circumferential side of the first main back pressure pocket1315a, and the main vane support protrusion1317which defines the second main bearing protrusion (no reference numeral) formed as a partial partition wall may be formed on the inner circumferential side of the second main back pressure pocket1315b. Accordingly, oil of low intermediate pressure may be filled inside of the first main back pressure pocket1315awhile oil of high intermediate pressure (or discharge pressure) may be filled inside of the second main back pressure pocket1315b.

The main vane support protrusion1317, as well as the first main bearing protrusion1316a, may protrude in the axial direction from the main axial bearing surface1311abetween the first main back pressure pocket1315aand the second main back pressure pocket1315band extend in the circumferential direction. Accordingly, the main vane support protrusion1317may not only support the vane1351,1352,1353in the axial direction, but also support the rotational shaft123in the radial direction together with the first main bearing protrusion1316a.

The main vane support protrusion1317may be formed to be flush with the main axial bearing surface1311a. However, in some cases, the main vane support protrusion1317may be formed to be lower than the main axial bearing surface1311a. This embodiment illustrates an example in which the main vane support protrusion1317is formed at a same height as the main axial bearing surface1311a, that is, the first main bearing protrusion1316a.

Referring toFIG.11, the main vane support protrusion1317according to this embodiment may extend from the main axial bearing surface1311ain an opposite direction to the first main bearing protrusion1316abetween the first main back pressure pocket1315aand the second main back pressure pocket1315b. Accordingly, the main vane support protrusion1317defines the second main bearing protrusion (no reference numeral) and also defines a portion of the main axial bearing surface1311a. With this structure, the main vane support protrusion1317may be located far away in the reciprocating direction of the vane1351,1352,1353, to thus maintain the volume of the main back pressure pocket1315bwhile securing a substantial axial support area for the rear end of the vane1351,1352,1353at the contact point P1 and/or near the contact point P1.

More specifically, the main vane support protrusion1317may be formed at an end portion close to the contact point P1, of both circumferential ends of the second main back pressure pocket1315b. For example, the main vane support protrusion1317may protrude in the axial direction from the inner circumferential surface of the second main back pressure pocket1315b, as in the previous embodiment. Accordingly, the main vane support protrusion1317defines a partial partition wall of the second main back pressure pocket1315b, that is, the inner wall surface1315c, and also defines the second main bearing protrusion (no reference numeral).

However, as illustrated inFIG.13, the main vane support protrusion1317according to this embodiment may extend from an end portion near the contact point P1 toward an opposite end portion in the circumferential direction, and an arcuate length (or central angle) L32 of the main vane support protrusion1317may be formed to be approximately half or less than an arcuate length (or central angle) L5 of the inner circumferential surface of the second main back pressure pocket1315b. In other words, a main oil passage groove1319, in which the inner circumferential side of the second main back pressure pocket1315bis open toward the rotational shaft123, may be formed in one side of the main vane support protrusion1317in the circumferential direction. Accordingly, the main oil passage groove1319may form the inlet of the second main back pressure pocket1315b, and the second main back pressure pocket1315bmay directly communicate with the oil passage (more specifically, a first oil passage hole)123through the main oil passage groove1319.

The main oil passage groove1319may be formed such that its arcuate length (or central angle) L6 is greater than or equal to an arcuate length (or central angle) L32 of the main vane support protrusion1317. Accordingly, the rear end of the vane1351,1352,1353passing near the contact point P1 may be supported in the axial direction, and simultaneously, oil suctioned through the oil passage125may be smoothly introduced into the second main back pressure pocket1315b.

In addition, the main oil passage groove1319may be formed so that its depth D1 is smaller than or equal to a depth D2 of the second main back pressure pocket1315b. For example, the main oil passage groove1319may be formed so that its depth D1 is equal to the depth D2 of the second main back pressure pocket1315b. Accordingly, a cross-sectional area of the main oil passage groove1319forming the inlet of the second main back pressure pocket1315bmay be secured as wide as possible while the main vane support protrusion1317may protrude axially toward the roller134at the inner circumferential side of the second main back pressure pocket1315b. Therefore, the rear end of the vane1351,1352,1353passing near the contact point P1 may be supported in the axial direction, and simultaneously oil suctioned through the oil passage125may be smoothly introduced into the second main back pressure pocket1315b.

Referring toFIGS.13and14, when the main vane support protrusion1317is formed on the inner circumferential surface of the second main back pressure pocket1315bas in this embodiment, the inner circumferential side of the second main back pressure pocket1315bmay be partially sealed, and accordingly, an oil storage capacity in the second main back pressure pocket1315bmay be improved. Accordingly, a pressure of oil supplied to the rear end surface of the vane1351,1352,1353may be made uniform, thereby suppressing or preventing pressure pulsation at the rear end surface of the vane1351,1352,1353. With this structure, a back pressure formed on the rear end surface of the vane1351,1352,1353may be constant, making it possible to suppress wobbling of the vane1351,1352,1353more effectively.

Referring toFIGS.10and12, the vane support protrusion may also be formed in the same way on the sub bearing132, as in the previous embodiment. In other words, the vane support protrusion (hereinafter, referred to as the sub vane support protrusion)1327may protrude axially from the inner circumferential surface of the second sub back pressure pocket1325band extend along the circumferential direction, and a sub oil passage groove1329may be formed at one side of the sub vane support protrusion1327. In this case as well, the sub vane support protrusion1327and the sub oil passage groove1329may be formed symmetrically to the main vane support protrusion1317and the main oil passage groove1329, respectively. Therefore, the sub vane support protrusion1327and the sub oil passage groove1329will be understood by the description of the main vane support protrusion1317and the main oil passage groove1329.

Additionally, the previously described vane support protrusion may be formed only on the sub bearing132, as in the previous embodiment. In other words, the main vane support protrusion (not illustrated) described above may be excluded and only the sub vane support protrusion1327may be formed. In this case as well, the sub vane support protrusion1327and the sub oil passage groove1329may be formed symmetrically to the main vane support protrusion1317and the main oil passage groove1329, respectively. Therefore, the sub vane support protrusion1327and the sub oil passage groove1329will be understood by the description of the main vane support protrusion1317and the main oil passage groove1329.

Hereinafter, description will be given of a vane support protrusion according to still another embodiment. That is, in the previous embodiments, the vane support protrusion extends from the inner circumferential surface of the back pressure pocket along the reciprocating direction of the vane or protrudes in the axial direction from the back pressure pocket. However, in some cases, the vane support protrusion may be formed to protrude axially from the back pressure pocket while extending from the inner circumferential surface of the back pressure pocket along the reciprocating direction of the vane.

FIG.15is a perspective view illustrating a main bearing and a sub bearing each having a vane support protrusion according to still another embodiment.FIG.16is a planar view illustrating the main bearing inFIG.15.FIG.17is a planar view illustrating the sub bearing inFIG.15.FIG.18is a schematic view for explaining an effect of the vane support protrusion inFIG.15, andFIG.19is a cross-sectional view, taken along line “XIX-XIX” ofFIG.18.

Referring toFIGS.15to19, as the basic configuration and operating effects of the rotary compressor according to this embodiment are almost the same as those of the previous embodiments, detailed description thereof will be replaced by the description of the previous embodiments. For example, at least one vane slot1341a,1341b,1341cmay be formed in the roller134eccentrically inserted into the cylinder133, and the vane1351,1352,1353may be slid into the vane slot1341a,1341b,1341c. The vane1351,1352,1353may be axially supported by the main bearing131and the sub bearing132, which are coupled to the both axial sides of the cylinder133. The back pressure pockets [1315aand1315b], [1325aand1325b] communicating with the oil passage125of the rotational shaft123may be formed in at least one of the main bearing131or the sub bearing132. The back pressure pockets [1315aand1315b], [1325aand1325b] may communicate with the back pressure chamber1342a,1342b,1342cdisposed inside the vane slot1341a,1341b,1341c. Accordingly, high-pressure oil may be introduced into the back pressure chamber1342a,1342b,1342cthrough the oil passage125of the rotational shaft123and the back pressure pockets [1315aand1315b], [1325aand1325b] to press the vane1351,1352,1353toward the cylinder133, thereby suppressing or preventing wobbling of the vane1351,1352,1353.

However, in this case, as described above, the back pressure pockets [1315aand1315b] and [1325aand1325b] are formed to be recessed by preset or predetermined depths into the main axial bearing surface1311aof the main bearing131and/or the sub axial bearing surface1321aof the sub bearing132that support the vane1351,1352,1353in the axial direction. This reduces the axial support area for the vane1351,1352,1353. As a result, a support force for the rear end of the vane1351,1352,1353may decrease and axial tilting may occur. In particular, in the case of the vane1351,1352,1353passing near the contact point P1, the vane1351,1352,1353may be subject to a strong gas repulsive force applied from the compression chamber to thereby be moved backward and/or more tilted in the axial direction.

Accordingly, in this embodiment, the vane support protrusion1317,1327extending from the main axial bearing surface1311aand/or the sub axial bearing surface1321amay be formed, as in the previous embodiments. However, in the embodiment, the vane support protrusions1317,1327may respectively be formed inside and outside of the back pressure pocket [1315a,1315b], [1325a,1325b], to secure a much wider axial support area for the vane1351,1352,1353without excessively reducing the volume of the back pressure pocket [1315a,1315b], [1325a,1325b]. The vane support protrusions1317,1327may be formed on at least one of the main bearing131or the sub bearing132, but in this embodiment, an example in which the vane support protrusions are formed on the main bearing131will be mainly described.

Referring toFIGS.15and16, the main plate portion1311of the main bearing131according to this embodiment may include, as described above, the first main back pressure pocket1315aand the second main back pressure pocket1315bformed along the circumferential direction to be spaced apart from each other by a preset or predetermined gap. The first main bearing protrusion1316amay be formed on the inner circumferential side of the first main back pressure pocket1315a, and the second main vane support protrusion1317described hereinafter, which defines the second main bearing protrusion (no reference numeral) formed as a partial partition wall, may be formed on the inner circumferential side of the second main back pressure pocket1315b. Accordingly, oil of a low intermediate pressure may be filled inside of the first main back pressure pocket1315awhile oil of a high intermediate pressure (or a discharge pressure) may be filled inside of the second main back pressure pocket1315b.

More specifically, a first main bearing protrusion1317amay be formed inside of the second main back pressure pocket1315b, and a second sub bearing protrusion1317bmay be formed outside of the second main back pressure pocket1315b. For example, the first main vane support protrusion1317amay extend in the circumferential direction (lateral direction) from the second main back pressure pocket1315bto be flush with the main axial bearing surface1311a, and the second main vane support protrusion1317bmay protrude in the axial direction from a partial section of the inner circumferential surface of the second main back pressure pocket1315bto be flush with the main axial bearing surface1311a. Accordingly, as illustrated inFIGS.18and19, the rear axial side surface of the vane1351,1352,1353may be supported in the axial direction by the first main vane support protrusion1317aand the second main vane support protrusion1317b, thereby greatly increasing the axial support area for the vane1351,1352,1353. This may effectively suppress or prevent axial tilting of the vane1351,1352,1353that passes near the contact point P1.

For example, the first main vane support protrusion1317amay be formed in an area, close to the contact point P1, in which the outer wall surface1315dand the second side wall surface1315fmeet, on the inner circumferential surface of the second main back pressure pocket1315b. The first main vane support protrusion1317amay protrude in the axial direction from the bottom surface of the second main back pressure pocket1315band simultaneously extend in the reciprocating direction of the vane1351,1352,1353from the main axial bearing surface1311atoward the inner wall surface1315cof the second main back pressure pocket1315b, namely, the second main vane support protrusion1317b. As the first vane support protrusion1317ais the same as the main vane support protrusion1317illustrated in the embodiment ofFIG.4, it may be understood from the description of the embodiment ofFIG.4.

The second main vane support protrusion1317bmay protrude in the axial direction from the main axial bearing surface1311aat one or a first end, close to the contact point P1, of circumferential ends at the inner circumferential side of the second main back pressure pocket1315band extend toward another or a second end of the opposite side in the circumferential direction, and the main oil passage groove1319may be formed in one side of the second main vane support protrusion1317bin the circumferential direction. As the second main vane support protrusion1317band the main oil passage groove1319are the same as the main vane support protrusion1317and the main oil passage groove1319illustrated in the embodiment ofFIG.10, they may be understood from the description of the embodiment ofFIG.10.

Referring toFIGS.15and17, the vane support protrusion may be formed in the same way on the sub bearing132. In other words, the first vane support protrusion (hereinafter, referred to as a first sub vane support protrusion)1327amay extend from the inner circumferential surface of the second sub back pressure pocket1325bin the reciprocating direction of the vane1351,1352,1353, and the second vane support protrusion (hereinafter, referred to as a second sub vane support protrusion)1327bmay protrude in the axial direction from the inner circumferential side of the second sub back pressure pocket1325band extend along the circumferential direction. In this case as well, a sub oil passage groove1329may be formed by being open in one side of the second sub vane support protrusion1327bin the circumferential direction. The first sub vane support protrusion1327amay be formed symmetrically to the first main vane support protrusion1317a, and the second sub vane support protrusion1327bmay be formed symmetrically to the second main vane support protrusions1317b. Accordingly, the first sub vane support protrusion1327aand the second sub vane support protrusion1327bmay be understood from the descriptions of the first main vane support protrusion1317aand the second main vane support protrusion1317b. This also applies to the main oil passage groove1319and the sub oil passage groove1329.

Additionally, the first and second vane support protrusions1327aand1327bdescribed above may be formed only on the sub bearing132. In this case as well, the first sub vane support protrusion1327aand the second sub vane support protrusion1327bmay be formed the same as the first main vane support protrusion1317aand the second main vane support protrusion1317b. Accordingly, the first sub vane support protrusion1327aand the second sub vane support protrusion1327bmay be understood from the descriptions of the first main vane support protrusion1317aand the second main vane support protrusion1317b. This also applies to the main oil passage groove1319and the sub oil passage groove1329.

Embodiments disclosed herein provide a rotary compressor capable of reducing friction loss, wear, and vibration noise due to axial tilting of a vane during an operation of the compressor.

Embodiments disclosed herein also provide a rotary compressor capable of increasing a support area for an axial side surface of a vane, which passes near a contact point during an operation of the compressor.

Further, embodiments disclosed herein provide a rotary compressor capable of suppressing or preventing friction loss or wear and vibration noise between an axial side surface of a vane, which passes near a contact point during an operation of the compressor, and an axial bearing surface facing the same while increasing a support area for the axial side surface of the vane.

Furthermore, embodiments disclosed herein provide a rotary compressor capable of quickly securing back pressure while enhancing axial support force applied to a vane, which passes near a contact point during an operation of the compressor.

Additionally, embodiments disclosed herein provide a rotary compressor capable of securing radial support force for a rotational shaft while quickly increasing back pressure for a vane during an operation of the compressor.

Embodiments disclosed herein provide a rotary compressor capable of suppressing a vane from tilting in an axial direction even when a high-pressure refrigerant such as R32, R410a, or CO2is used.

To achieve those aspects and other advantages of the subject matter disclosed herein, a rotary compressor is provided that may include a casing, a cylinder, a main bearing, a sub bearing, a rotational shaft, a roller, and at least one vane. The casing may define an oil storage space therein, the cylinder may be fixed inside of the casing to form a compression space, the main bearing and sub bearing may be disposed on both sides of the cylinder in an axial direction, the rotational shaft may be supported on the main bearing and the sub bearing and define an oil passage therein, the roller may be disposed on the rotational shaft and form at least one contact point where an outer circumferential surface thereof is in contact with an inner circumferential surface of the cylinder, and the at least one vane may be slidably inserted into the roller to divide the compression space into a plurality of compression chambers. A back pressure pocket having a preset or predetermined depth may be formed in a bearing surface, facing the roller, of at least one of the main bearing or the sub bearing. A vane support portion may be formed on the bearing surface to support the vane in the axial direction. The vane support portion may include a vane support protrusion that extends along a reciprocating direction of the vane from an inner circumferential surface of the back pressure pocket at an end, adjacent to the contact point, of both ends of the back pressure pocket in a circumferential direction or extend along the inner circumferential surface of the back pressure pocket in the circumferential direction. With this structure, a wide axial support area for a rear end of the vane passing the contact point and/or near the contact point may be secured to suppress or prevent axial tilting of the vane, thereby reducing friction loss or wear and vibration noise due to the axial tilting of the vane during operation of the compressor.

The vane support protrusion may be formed such that at least a portion thereof is located in a discharge section of the compression chamber. This may secure a wide axial support area for a rear end of the vane that passes the contact point and/or near the contact point.

A circumferential length of the vane support protrusion may be shorter than a length of the discharge section. This may suppress or prevent an unnecessary expansion of an axial support area for the rear end of the vane, which is located far away from the contact point and/or a portion near the contact point, thereby reducing friction loss and wear.

The vane support protrusion may extend from the bearing surface adjacent to the contact point. A height of the vane support protrusion may be lower than or equal to a height of the bearing surface. This may expand a substantial axial support area for the rear end of the vane and smoothly lubricate between the rear end of the vane and an axial bearing surface facing the rear end.

The vane support protrusion may be formed to be flush with the bearing surface. This may expand a substantial axial support area for the rear end of the vane.

An oil supply groove that communicates with the back pressure pocket and extending toward a radial outside of the back pressure pocket may be formed in at least one of the main bearing or the sub bearing. The oil supply groove may at least partially overlap the vane support protrusion in a radial direction. This may expand a substantial axial support area for the rear end of the vane and simultaneously smoothly lubricate between the rear end of the vane and the bearing surface facing the rear end.

An oil supply guide groove may extend along a longitudinal direction of the vane from an axial side surface of the vane in contact with the bearing surface. The oil supply guide groove may communicate with the back pressure pocket without at least partially overlapping the vane support protrusion. This may expand a substantial axial support area for the rear end of the vane and simultaneously smoothly provide lubrication between the rear end of the vane and the bearing surface facing the rear end.

The back pressure pocket may include an inner wall surface, an outer wall surface, and a first side wall surface and a second side wall surface that connect both ends of the inner wall surface and the outer wall surface. The vane support protrusion may be formed as the second side wall surface and the outer wall surface adjacent to the contact point extend toward the inner wall surface. With this structure, the vane support protrusion may be formed continuously from the bearing surface, which may not only stabilize the behavior of the vane, but also secure a wide inlet area of the back pressure pocket, thereby quickly increasing back pressure on the vane and maintaining it stably.

An inner circumferential surface of the vane support protrusion may be formed in an area where the second side wall surface and the outer wall surface meet. A gap between the inner circumferential surface of the vane support protrusion and the inner wall surface may be gradually decreased in a direction toward the contact point. With this structure, the vane support protrusion may be formed to correspond to a movement path of the vane and stably support the rear end of the vane.

More specifically, the outer wall surface may be formed in an arcuate shape with a first curvature, and the inner circumferential surface of the vane support protrusion may be formed in an arcuate shape with a second curvature. The second curvature may be greater than the first curvature. With this structure, the vane support protrusion may be formed to correspond to the movement path of the vane and stably support the rear end of the vane.

The outer wall surface may be formed in an arcuate shape with a first curvature, and the second side wall surface defining the inner circumferential surface of the vane support protrusion may be formed in an arcuate shape with a second curvature. An arcuate length of the vane support protrusion may be smaller than or equal to an arcuate length of the outer wall surface. This may suppress or prevent an unnecessary contact between the vane and the axial bearing surface in an area far from the contact point, thereby reducing friction loss and wear.

A shortest distance from the contact point to the vane support protrusion may be 0.7 to 0.9 times a length of the vane. This may secure a substantial axial support area for the rear end of the vane at the contact point and/or near the contact point.

The back pressure pocket may include an inner wall surface, an outer wall surface, and a first side wall surface and a second side wall surface connecting both ends of the inner wall surface and the outer wall surface. The vane support protrusion may protrude in the axial direction and extend along the inner circumferential surface of the back pressure pocket. With this structure, the vane support protrusion may be located far away in the reciprocating direction of the vane, thereby maintaining a volume of the back pressure pocket while securing a substantial axial support area for the rear end of the vane at the contact point and/or near the contact point.

For example, an oil passage groove that is open toward the outer circumferential surface of the rotational shaft in the back pressure pocket may be formed at one side of the vane support protrusion in the circumferential direction. An arcuate length of the vane support protrusion may be shorter than or equal to an arcuate length of the oil passage groove. With this structure, the vane support protrusion may be formed continuously from the axial bearing surface, which may not only stabilize the behavior of the vane, but also secure a wide inlet area of the back pressure pocket, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

More specifically, a depth of the oil passage groove may be formed to be equal to a depth of the back pressure pocket with the oil passage groove. This may secure the inlet area of the back pressure pocket as wide as possible, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

Additionally, the vane support protrusion may be formed to support an end, adjacent to the rotational shaft, of both ends of the vane in the reciprocating direction. This may secure a substantial axial support area for the rear end of the vane at the contact point and/or near the contact point and also maintain the volume of the back pressure pocket.

The back pressure pocket may include an inner wall surface, an outer wall surface, and a first side wall surface and a second side wall surface that connect both ends of the inner wall surface and the outer wall surface. The vane support protrusion may include a first vane support protrusion that extends along a reciprocating direction of the vane from one end of the back pressure pocket adjacent to the contact point, and a second vane support protrusion protruding in the axial direction from an inner circumferential surface of the back pressure pocket. With this structure, a cross-sectional area of the vane support protrusion may be formed as wide as possible while minimizing a reduction in volume of the back pressure pocket, so as to stably support the rear end of the vane in the axial direction, thereby reducing friction loss or wear and vibration noise due to axial tilting of the vane during operation of the compressor.

The first vane support protrusion may be formed as the second side wall surface and the outer wall surface adjacent to the contact point extend toward the inner wall surface. With this structure, the vane support protrusion may be formed continuously from the bearing surface, which may not only stabilize the behavior of the vane, but also secure the wide inlet area of the back pressure pocket, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

More specifically, an inner circumferential surface of the first vane support protrusion may be formed in an area where the second side wall surface and the outer wall surface meet. A gap between an inner circumferential surface of the first vane support protrusion and the inner wall surface may be gradually decreased in a direction toward the contact point. With this structure, the vane support protrusion may be formed to correspond to a movement path of the vane and stably support the rear end of the vane.

More specifically, the outer wall surface may be formed in an arcuate shape with a first curvature, and the inner circumferential surface of the first vane support protrusion may be formed in an arcuate shape with a second curvature. The second curvature may be greater than the first curvature. With this structure, the vane support protrusion may be formed to correspond to the movement path of the vane and stably support the rear end of the vane.

Additionally, the outer wall surface may be formed in an arcuate shape with a first curvature, and the inner circumferential surface of the first vane support protrusion may be formed in an arcuate shape with a second curvature. An arcuate length of the first vane support protrusion may be smaller than or equal to an arcuate length of the outer wall surface. With this structure, the vane support protrusion may be formed continuously from the axial bearing surface, which may not only stabilize the behavior of the vane, but also secure the wide inlet area of the back pressure pocket, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

A shortest distance from the contact point to the first vane support protrusion may be 0.7 to 0.9 times a length of the vane. This may secure a substantial axial support area for the rear end of the vane at the contact point and/or near the contact point.

An oil passage groove that is open toward the outer circumferential surface of the rotational shaft in the back pressure pocket may be formed at one side of the second vane support protrusion in the circumferential direction. An arcuate length of the second vane support protrusion may be shorter than or equal to an arcuate length of the oil passage groove. With this structure, the vane support protrusion may be formed continuously from the axial bearing surface, which may not only stabilize the behavior of the vane, but also secure the wide inlet area of the back pressure pocket, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

For example, a depth of the oil passage groove may be formed to be equal to a depth of the back pressure pocket. This may secure the inlet area of the back pressure pocket as wide as possible, thereby quickly increasing back pressure on the vane and simultaneously maintaining the back pressure stably.

The back pressure pocket may be provided as a plurality having different pressure and disposed to be spaced apart from each other in the circumferential direction with the bearing surface interposed therebetween. The vane support portion may be formed at a back pressure pocket having relatively high pressure among the plurality of back pressure pockets. With this structure, a wide axial support area for the rear end of the vane passing the contact point and/or near the contact point may be secured to suppress axial tilting of the vane, thereby reducing friction loss or wear and vibration noise due to axial tilting of the vane during operation of the compressor.

It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Embodiments are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and 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, embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

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 invention belongs. It will be further understood that 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.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.