Patent Description:
A compressor applied to a refrigeration cycle such as a refrigerator or an air conditioner serves to compress refrigerant gas and transmit the compressed refrigerant gas to a condenser. A rotary compressor or a scroll compressor is mainly applied to an air conditioner. Recently, the scroll compressor is applied even not only to the air conditioner but also to a compressor for hot water supply that requires a high compression ratio than the air conditioner.

The compressor may be classified into a hermetic compressor in which a driving unit (or a motor part) and a compression part are included together in a casing, and an open-type compressor in which a driving unit (or a motor part) is included outside a casing and only a compression part is included in the casing.

The compressor may be classified into a top compression type compressor and a bottom compression type compressor according to locations of a driving motor constituting a driving unit or a motor part, and a compression part. The top compression type compressor is a compressor type in which a compression part is located above a driving motor, and the bottom compression type compressor is a compressor type in which a compression part is located below a driving motor. This classification is based on an example in which a casing is installed as a vertical type or a standing type. When a casing is installed as a horizontal type, a left side may be classified as an upper side and a right side may be classified as a lower side for convenience.

The compressor may be respectively classified into a low-pressure type compressor in which an inner space of a casing including a compression part provides suction pressure and a high-pressure type compressor in which an inner space of a casing including a compression part provides discharge pressure. The top compression type compressor may be configured as a low-pressure type or a high-pressure type. However, the bottom compression type compressor is generally configured as a high-pressure type compressor in consideration of a position of a refrigerant suction pipe.

A constant amount of oil is sealed into the compressor described above, and the sealed oil is pumped through a rotating shaft during operation of the compressor to lubricate a sliding portion in a compression part and/or a sliding portion between the compression part and the rotating shaft. This oil may be mixed with refrigerant discharged from the compression part and leaked to outside of the compressor through a refrigerant discharge pipe. Then, friction loss or abrasion due to oil shortage may occur in the compressor.

Thus, in the related art, a method of providing an oil separation device separately in an inner space of a casing is disclosed. Patent document <NUM> (<CIT>) illustrates an example in which an oil separation member is installed between a driving motor and a discharge pipe, i.e., in a casing. This may reduce a cost of manufacturing a compressor including an oil separation device, compared to when a separate oil separation device is installed outside a casing.

However, when a separate oil separation device is included in a casing as disclosed in patent document <NUM>, a number of parts may increase thereby increasing a manufacture cost. In addition, efficiency of the compressor may deteriorate due to excessive increase in discharge resistance. In relation to this, instead of excluding an oil separation device from inside of a casing, a method of increasing an oil separation effect by extending a refrigerant discharge pipe toward a compression part or a driving motor is provided.

However, when a refrigerant discharge pipe extends toward a driving motor like the compressor in the related art, an oil separation effect in an oil separation space belonging to an inner space of a casing may be increased by delaying refrigerant discharge. However, since a space between a lower end of the refrigerant discharge pipe and an upper end of the driving motor is very small, backflow or overflow of sealed oil may occur, That is, when a speed of sealing oil through a refrigerant discharge pipe is higher than a moving speed of oil moving into a lower space of a casing through a driving motor, the oil sealed through the refrigerant discharge pipe may not pass through the driving motor, and may be stagnant between the driving motor and the refrigerant discharge pipe. Then, as the upper space of the stagnant oil is sealed, an oil backflow phenomenon or an oil overflow phenomenon in which the oil is pushed into the refrigerant discharge pipe may be caused. Thus, as oil sealing time is delayed, a whole time of manufacturing the compressor is increased, thereby raising a manufacture cost.

In addition, when oil is sealed using a refrigerant discharge pipe like the compressor in the related art, in consideration of the stagnant oil described above, a clearance between a casing and a driving motor and/or a clearance provided in-between of a stator coil may be enlarged to suppress oil from being stagnant. However, in this case, in correspondence with an increase in a clearance between a casing and a driving motor and/or a clearance provided in-between of a stator coil, a flux path area of a stator or a number of winding wires of the stator coil (a coil diameter) is reduced, thereby deteriorating motor efficiency.

On the other hand, <CIT> discloses, in one embodiment, a discharge pipe of a compressor, the discharge pipe having a hole on its circumferential surface; and in another embodiment, a guide member surrounding a discharge pipe. Further, <CIT> discloses a discharge pipe of a compressor having multiple small hols on its circumferential surface.

A further document is <CIT> that shows a compressor of the type claimed in the preamble of claim <NUM>. The document <CIT> discloses a heremtic compressor with a discharge tube on the upper end thereof that provides lateral openings so as to allow the compressed gas to pass whereby the oil remains on the edge of the openings.

Therefore, to obviate those problems, an aspect of the detailed description is to provide a compressor capable of, when oil is sealed into a refrigerant discharge pipe, suppressing the sealed oil from flowing back or overflowing through the refrigerant discharge pipe even when an inlet of the refrigerant discharge pipe is blocked.

Further, an aspect of the detailed description is to provide a compressor capable of, when oil is sealed, suppressing the oil from flowing back or overflowing through a refrigerant discharge pipe by inserting the refrigerant discharge pipe deep into an upper space of a casing, without having to install an oil separation device inside and/or outside the casing.

Still further, an aspect of the detailed description is to provide a compressor capable of ensuring both a flux path area of a stator and a number of winding wires of a stator coil or a coil diameter and, when oil is sealed, suppressing the oil from flowing back or overflowing through a refrigerant discharge pipe.

Another aspect of the detailed description is to provide a compressor capable of, when oil is sealed through a refrigerant discharge pipe, suppressing the oil from flowing back or overflowing through a refrigerant discharge pipe and, during operation of the compressor, suppressing excessive leak of oil through the refrigerant discharge pipe.

Further, another aspect of the detailed description is to provide a compressor such that a structure of suppressing oil leak is simplified to reduce a manufacture cost of the compressor and, when oil is sealed through a refrigerant discharge pipe, backflow or overflow of the oil through the refrigerant discharge pipe is effectively suppressed.

Still further, another aspect of the detailed description is to provide a compressor including a refrigerant discharge pipe further provided with a separate path in addition to an inlet such that the compressor may effectively suppress oil backflow or overflow which may occur during oil sealing and also suppress oil leak through the path during operation of the compressor.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a scroll compressor that includes a further including: a sealed casing, a driving motor, a compression part, a rotating shaft, and a refrigerant discharge pipe. The motor unit is disposed in an inner space of the casing. The compression part is disposed in an inner space of the casing, and compress refrigerant. The rotating shaft connects the driving motor to the compression part to transmit driving force of the driving motor to the compression part; and The refrigerant discharge pipe includes an inlet and an outlet at both ends and be coupled through the casing, the inlet communicating with the inner space of the casing to be apart from an upper end of the driving motor by a preset space, The refrigerant discharge pipe is provided with at least one communication hole between the inlet and the outlet to penetrate between an outer circumferential surface and an inner circumferential surface of the refrigerant discharge pipe. Thus, during oil sealing through the refrigerant discharge pipe, a flux path area of a driving motor is ensured, and a number of winding wires and/or a coil diameter of a stator coil is ensured. Thus, efficiency of the driving motor may be maintained and backflow or overflow of oil through the refrigerant discharge pipe may be suppressed. In addition, during operation of the compressor, oil is suppressed from being excessively leaked through the refrigerant discharge pipe without having to include a separate oil separator inside or inside the casing.

As an example, the communication hole is provided in a position apart from the inlet of the refrigerant discharge pipe by a preset space. Accordingly, even when the inlet of the refrigerant discharge pipe is blocked by oil stagnant in the upper space of the casing, the upper space of the casing communicates with the refrigerant discharge pipe through a communication hole to block sealing of the upper space. Accordingly, backflow or overflow of oil that may be caused by the sealing of the upper space may be suppressed.

In detail, the communication hole may be provided in a circular shape. Thus, the communication hole may be easily formed, thereby reducing a manufacture cost.

In detail, the communication hole may be provided to have a non-circular shape elongating in a longitudinal direction. By doing so, an opening area of an upper portion of the communication hole may be relatively reduced, and thus, oil that has not been separated from refrigerant during normal operation of the compressor may be suppressed from being leaked through the communication hole.

As another example, the communication hole extends from the inlet of the refrigerant discharge pipe to a preset height. Thus, on condition that a total opening area of the communication hole is same, when an opening area of an upper portion of the communication hole is reduced, oil leak through the communication hole is suppressed during normal operation of the compressor.

In detail, the communication hole may have a portion, a horizontal width of which decreases along a direction from the inlet of refrigerant discharge pipe toward the outlet of the refrigerant discharge pipe. By doing so, an opening area in an upper portion of the communication hole may be reduced, and oil leak through the communication hole may be effectively suppressed during normal operation of the compressor.

As another example, with respect to the at least one communication hole, a plurality of communication holes may be disposed along a circumferential direction of the refrigerant discharge pipe. The plurality of communication holes may have a same area and/or a same distance therebetween along a circumferential direction. Accordingly, the communication hole may be easily formed, and when the inlet of the communication hole is blocked by oil, the pressure (air) in the upper space may evenly and quickly flow out to effectively suppress backflow or overflow of the sealed oil.

As another example, an entire opening area of the at least one communication hole may be larger than or same as an area of the inlet of the refrigerant discharge pipe. Thus, when the inlet of the communication hole may be blocked by oil during oil sealing, the pressure (air) in the upper space may evenly and quickly flow out to effectively suppress backflow or overflow of the sealed oil.

As another example, an entire area of the communication hole may be less than an inlet area of the refrigerant discharge pipe. By doing so, the oil may be suppressed from not being separated from refrigerant during normal operation of the compressor and leaked to outside the compressor through the communication hole.

As another example, a distance from the inlet of the refrigerant discharge pipe to an upper end of the communication hole may be less than half of a length of the refrigerant discharge pipe accommodated in the inner space of the casing. By doing so, during oil sealing, backflow or overflow of the sealed oil through the refrigerant discharge pipe may be suppressed, and during normal operation, excessive leak of oil that has not been separated from refrigerant through the refrigerant discharge pipe may be suppressed.

As another example, a distance from the inlet of the refrigerant discharge pipe to an upper end of the communication hole may be greater than or equal to <NUM> or <NUM> times of a value obtained by dividing a total amount (ℓ) of oil sealed into the inner space of the casing by a horizontal cross-sectional area of the casing. Thus, leak of oil with refrigerant may be suppressed and, during oil sealing, backflow or overflow of the sealed oil through the communication hole may be effectively suppressed by properly limiting an insertion depth of the refrigerant discharge pipe without having to include a separate oil separator.

As another example, an oil blocking portion surrounding the refrigerant discharge pipe to be apart from the refrigerant discharge pipe by a preset distance is provided in an outer circumferential portion of the refrigerant discharge pipe. Thus, during oil sealing, backflow or overflow of the sealed oil through the communication hole is effectively suppressed. In addition, as an oil separator having a simple structure is provided in the casing, oil may be smoothly sealed through the refrigerant discharge pipe during oil sealing, and effectively suppressed from being leaked through the communication hole during normal operation.

In detail, the oil blocking portion at least partially overlaps the communication hole of the refrigerant discharge pipe in an axial direction of the rotating shaft. By doing so, oil that has not been separated from refrigerant during normal operation due to blocking of the communication hole by the oil blocking portion is suppressed from being leaked through the communication hole.

In detail, a distance between a lower end of the oil blocking portion and an upper end of the driving motor facing the lower end of the oil blocking portion in an axial direction of the rotating shaft may be longer than or equal to a distance from the inlet of the refrigerant discharge pipe and an upper end of the driving motor facing the inlet of the refrigerant discharge pipe in an axial direction of the rotating shaft. Thus, when the inlet of the refrigerant discharge pipe is blocked, blocking of the communication hole by the oil blocking portion may be prevented. Then, the oil blocking portion may be provided on an outer circumference of the refrigerant discharge pipe, and pressure in the upper space may smoothly flow out through a space between the oil blocking portion and the refrigerant discharge pipe and through the communication hole.

As another example, the compression part includes: an orbiting scroll coupled to the rotating shaft and configured to perform an orbiting motion, and a non-orbiting scroll engaged with the orbiting scroll to define a compression chamber. An insertion depth of the refrigerant discharge pipe, which is an axial length of the refrigerant discharge pipe accommodated in the casing, may be provided to be greater than the half of a distance between the upper end of the rotating shaft and an inner circumferential surface of the casing facing the upper end of the rotating shaft. Thus, in a bottom-compression type scroll compressor in which a compression part is located below a driving motor, leak of oil that has not been separated from refrigerant in an inner space of a casing to outside of the casing may be effectively suppressed without having to include a complicated oil separator inside or inside the casing.

Specifically, the refrigerant discharge pipe may be provided to have an inlet area equal to an outlet area. By doing so, a structure of the refrigerant discharge pipe may be simplified in the bottom-compression type scroll compressor to thereby reduce a manufacture cost. In addition, the oil may be smoothly sealed during oil sealing and leak of oil with refrigerant may be suppressed during normal operation of the bottom-compression type scroll compressor.

As another example, the compression part may include a cylinder, a roller inserted into the cylinder and included in the rotating shaft to rotate, and a vane slidably inserted into one of the cylinder and the roller. An insertion depth of the refrigerant discharge pipe may be provided to be greater than the half of a distance between the upper end of the rotating shaft and an inner circumferential surface of the casing facing the upper end of the rotating shaft. Thus, in a bottom-compression type rotary compressor in which a compression part is located below a driving motor, leak of oil that has not been separated from refrigerant in an inner space of a casing to outside of the casing may be effectively suppressed without having to include a complicated oil separator inside or inside the casing.

Specifically, the inlet and the outlet of the refrigerant discharge pipe may have the same horizontal sectional area. By doing so, a structure of the refrigerant discharge pipe may be simplified in the bottom-compression type rotary compressor to thereby reduce a manufacture cost. In addition, the oil may be smoothly sealed during oil sealing and leak of oil with refrigerant may be suppressed during normal operation of the bottom-compression type rotary compressor.

Description will now be given in detail of a compressor disclosed herein, with reference to the accompanying drawings. In the following description, a description of some components may be omitted to clarify features of the present disclosure.

In addition, the term "upper side" used in the following description refers to a direction away from a support surface for supporting a scroll compressor according to an implementation of the present disclosure, that is, a direction toward a driving unit (motor part or driving motor) when viewed based on the driving unit (motor part or driving motor) and a compression part. The term "lower side" refers to a direction toward the support surface, that is, a direction toward the compression part when viewed based on the driving unit (motor part or driving motor) and the compression part.

The term "axial direction" used in the following description refers to a lengthwise (longitudinal) direction of a rotating shaft. The "axial direction" may be understood as an up and down (or vertical) direction. The term "radial direction" and "horizontal direction" refer to a direction that orthogonally intersects the rotating shaft.

In addition, hereinafter, a bottom compression type and high pressure type compressor in which a refrigerant suction pipe constituting a suction passage is directly connected to a compression part and a refrigerant discharge pipe communicates with an inner space of a casing so that the inner space of the casing provides discharge pressure is described as an example.

In addition, hereinafter, a scroll compressor is described as an example. However, the description herein may also apply to a case when a refrigerant discharge pipe is connected to an upper end of a casing, like a rotary compressor.

<FIG> is a perspective view illustrating an inner structure of a scroll compressor including a temperature detection unit in accordance with this implementation. <FIG> is a longitudinal sectional view of a bottom-compression type scroll compressor in accordance with this implementation.

Referring to <FIG> and <FIG>, a high-pressure and bottom-compression type scroll compressor (hereinafter, referred to as a scroll compressor) according to this implementation includes a driving motor <NUM> constituting a motor part disposed in an upper portion of a casing <NUM>, and a main frame <NUM>, a fixed scroll <NUM>, an orbiting scroll <NUM>, and a discharge cover <NUM> each disposed below the driving motor <NUM>. In general, the driving motor <NUM> may constitute the motor part as described above, and the main frame <NUM>, the fixed scroll <NUM>, the orbiting scroll <NUM>, and the discharge cover <NUM> may constitute a compression part C.

The driving motor <NUM> constituting the motor part is coupled to an upper end of a rotating shaft <NUM> to be described later, and the compression part C is coupled to a lower end of the rotating shaft <NUM>. Accordingly, a compressor <NUM> constitutes the bottom-compression type structure described above, and the compression part C is connected to the driving motor <NUM> by the rotating shaft <NUM> to operate according to rotational force of the driving motor <NUM>. Thus, the driving motor <NUM> may be understood as a driving unit configured to drive the compression part C. Hereinafter, a driving motor may be also referred as a motor part or a driving unit.

Referring to <FIG> and <FIG>, the casing <NUM> according to the implementation may include a cylindrical shell <NUM>, an upper shell <NUM>, and a lower shell <NUM>. The cylindrical shell <NUM> may be formed in a cylindrical shape with upper and lower ends open. The upper shell <NUM> may be coupled to cover the open upper end of the cylindrical shell <NUM>. The lower shell <NUM> may be coupled to cover the open lower end of the cylindrical shell <NUM>. Accordingly, the inner space 110a of the casing <NUM> may be sealed. The sealed inner space 110a of the casing <NUM> may be divided into a lower space S1 and an upper space S2 based on the driving motor <NUM>.

The lower space S1 may be a space defined below the driving motor <NUM>. The lower space S1 may be further divided into an oil storage space S11 and an outflow passage S12 with the compression part C therebetween.

The upper space S2 may be a space defined above the driving motor <NUM> to form an oil separating space in which oil is separated from refrigerant discharged from the compression part C. The upper space S2 communicates with a refrigerant discharge pipe <NUM> which will be described later.

The driving motor <NUM> and the main frame <NUM> may be fixedly inserted into the cylindrical shell <NUM>. An outer circumferential surface of the driving motor <NUM> and an outer circumferential surface of the main frame <NUM> may be respectively provided with an oil return passage (no reference numeral) spaced apart from an inner circumferential surface of the cylindrical shell <NUM> by a predetermined distance.

A refrigerant suction pipe <NUM> is coupled through a side surface of the cylindrical shell <NUM>. Accordingly, the refrigerant suction pipe <NUM> is coupled through the cylindrical shell <NUM> forming the casing <NUM> in a radial direction.

An inner end of the refrigerant discharge pipe <NUM> may be coupled through an upper portion of the upper shell <NUM> to communicate with the inner space 110a of the casing <NUM>, specifically, the upper space S2 defined above the driving motor <NUM>. Accordingly, the inner end of the refrigerant discharge pipe <NUM> constitutes an inlet 116a, and an outer end of the refrigerant discharge pipe <NUM> constitutes an outlet 116b.

Referring to <FIG> and <FIG>, the refrigerant discharge pipe <NUM> according to this implementation may be coupled through a center of the upper shell <NUM> in an axial direction of the rotating shaft <NUM> (hereinafter referred to as an axial direction) to be located on a same axial line as that of a center of the upper shell <NUM>, i.e., an axial center O of the rotating shaft <NUM> which will be described later. Accordingly, the inlet 116a of the refrigerant discharge pipe <NUM> may be spaced apart from an upper end of the rotating shaft <NUM> by a preset distance. This will be described later again together with a communication hole <NUM>.

One end portion of an oil circulation pipe (not illustrated) may be coupled through a lower half portion of the lower shell <NUM>. Both ends of the oil circulation pipe may be open, and another end of the oil circulation pipe may be coupled through the refrigerant suction pipe <NUM>. An oil circulation valve (not illustrated) may be installed in a middle portion of the oil circulation pipe.

Referring to <FIG> and <FIG>, the driving motor <NUM> according to this implementation may include a stator <NUM> and a rotor <NUM>. The stator <NUM> is fixedly inserted into the inner circumferential surface of the cylindrical shell <NUM>, and the rotor <NUM> is rotatably disposed in the stator <NUM>.

The stator <NUM> includes a stator core <NUM> and a stator coil <NUM>.

The stator core <NUM> is formed in an annular shape or a hollow cylindrical shape and is shrink-fitted onto the inner circumferential surface of the cylindrical shell <NUM>. A first oil return passage Po1 is arranged on an outer circumferential surface of the stator core <NUM> to be spaced apart from an inner circumferential surface of the cylindrical shell <NUM>. The first oil return passage Po1 communicates with a second oil return passage Po2 of a compression part C which is to be described later. Accordingly, oil sealed into the upper space S2 or oil separated from refrigerant in the upper space S2 is returned to the oil storage space S11 of the casing <NUM> through the first oil return passage Po1 and the second oil return passage Po2.

The stator coil <NUM> is provided to have a preset wire diameter, and wound around the stator core <NUM> in correspondence with a preset number of winding wires. A coil clearance 1212a is provided in-between of the stator coil <NUM>, i.e., in a bundle of the stator coil <NUM>, The coil clearance 1212a provides an inner passage together with a gap between the stator <NUM> and the rotor <NUM>. The inner passage may constitute an oil return passage or a refrigerant discharge passage. Particularly, when a compressor is assembled, i.e., when oil is sealed, the inner passage functions as a part of the first oil return passage Po1. Accordingly, hereinafter, it may be understood that the oil return passage Po1 includes an internal passage including a clearance provided in-between of the stator coil <NUM> and a clearance between the stator <NUM> and the rotor <NUM>, in addition to the passage between the casing <NUM> and the stator <NUM> described above.

An insulator <NUM> is an insulating member, and inserted between the stator core <NUM> and the stator coil <NUM>. The insulator <NUM> extends from both upper and lower ends of the stator core <NUM> in an axial direction. For example, the insulator <NUM> may extend to a position higher than that of the inlet 116a of the refrigerant discharge pipe <NUM>, i.e., closer to an inner circumferential surface of the upper shell <NUM>. Thus, as refrigerant in the upper space S2 avoids the insulator <NUM> and is guided toward the inlet 116a of the refrigerant discharge pipe <NUM>, a discharge distance of the refrigerant may be further extended to enhance an oil separation effect.

The rotor <NUM> may include a rotor core <NUM> and permanent magnets <NUM>.

The rotor core <NUM> is formed in a cylindrical shape to be accommodated in a rotor accommodating portion 1211a defined in the central portion of the stator core <NUM>.

Specifically, the rotor core <NUM> may be rotatably inserted into the rotor accommodating portion 1211a of the stator core <NUM> with a predetermined gap (no reference numeral) therebetween. The permanent magnets <NUM> may be embedded in the rotor core <NUM> at preset intervals along the circumferential direction.

A balance weight <NUM> may be coupled to a lower end of the rotor core <NUM>. Alternatively, the balance weight <NUM> may be coupled to the rotating shaft. This implementation will be described based on an example in which the balance weight <NUM> is coupled to the rotating shaft <NUM>. The balance weight <NUM> may be disposed on each of a lower end side and an upper end side of the rotor, and the two balance weights <NUM> may be installed symmetrically to each other.

The rotating shaft <NUM> is coupled to the center of the rotor core <NUM>. An upper end portion of the rotating shaft <NUM> is press-fitted to the rotor <NUM>, and a lower end portion of the rotating shaft <NUM> is rotatably inserted into the main frame <NUM> to be supported in the radial direction.

The main frame <NUM> is provided with a main bearing <NUM> configured as a bush bearing to support the lower end portion of the rotating shaft <NUM>. Accordingly, a portion, which is inserted into the main frame <NUM>, of the lower end portion of the rotating shaft <NUM> may smoothly rotate inside the main frame <NUM>.

The rotating shaft <NUM> may transfer a rotational force of the driving motor <NUM> to an orbiting scroll <NUM> constituting the compression part C. Accordingly, the orbiting scroll <NUM> eccentrically coupled to the rotating shaft <NUM> may perform an orbiting motion with respect to the fixed scroll <NUM>.

An oil supply passage <NUM> is provided to have a hollow shape in the rotating shaft <NUM>. The oil supply passage <NUM> extends from a lower end to a middle height of the rotating shaft <NUM>, e.g., to a main bearing portion <NUM> that is to be described later. Accordingly, the oil supply passage <NUM> may have a shape closed from a middle portion to an upper portion of the rotating shaft <NUM> to enable to supply oil to a sliding unit using differential pressure.

An oil pickup <NUM> configured to pump oil filled in the oil storage space S11 may be coupled to a lower end of the rotating shaft <NUM>. Accordingly, during rotation of the rotating shaft <NUM>, the oil filled in the oil storage space S11 is sucked into an upper end of the rotating shaft <NUM> through the oil pickup <NUM> and the oil supply passage <NUM> to lubricate a sliding unit.

Referring to <FIG> and <FIG>, the compression part C according to this implementation includes the main frame <NUM>, the fixed scroll <NUM>, and the orbiting scroll <NUM>. The second oil return passage Po2 communicating with the first oil return passage Po1 described above is provided in an outer circumferential surface of the compression part C to be spaced apart from an inner circumferential surface of the casing <NUM>. Accordingly, oil sealed into the upper space S2 or oil separated from refrigerant in the upper space S2 is returned to the oil storage space S11 of the casing <NUM> through the first oil return passage Po1 and the second oil return passage Po2.

The main frame <NUM> may include a frame end plate <NUM>, a frame side wall <NUM>, and a main bearing portion <NUM>. The frame end plate <NUM> is installed below the driving motor <NUM>. A main bearing hole <NUM> constituting the main bearing portion <NUM> to be described later may be formed through a center portion of the frame end plate <NUM> in an axial direction. The frame side wall <NUM> may extend in a cylindrical shape from an edge of a lower side surface of the frame end plate <NUM>, and be fixed to the inner circumferential surface of the cylindrical shell <NUM> by performing shrink-fitting or welding. The main bearing portion <NUM> includes a main bearing hole <NUM> through which the rotating shaft <NUM> is rotatably inserted to support the rotating shaft <NUM> in the radial direction.

The fixed scroll <NUM> includes a fixed end plate <NUM>, a fixed side wall <NUM>, a sub bearing portion <NUM>, and a fixed wrap <NUM>.

The fixed end plate <NUM> is provided in a disk shape and arranged below the frame end plate <NUM> with a preset space therebetween. A main bearing hole <NUM> constituting the sub bearing unit <NUM> is formed through a center portion of the frame end plate <NUM> in a longitudinal direction. A first discharge port <NUM> and a second discharge port <NUM> are provided around the sub bearing hole <NUM>. The first and second discharge ports <NUM> and <NUM> communicate with a first compression chamber V1 and a second compression chamber V2, respectively, such that compressed refrigerant is discharged into a muffler space 160a of the discharge cover <NUM>.

The first discharge port <NUM> and the second discharge port <NUM> are provided in a position eccentric from a center of the fixed end plate <NUM>. In other words, as the sub bearing hole <NUM> is provided through the center of the fixed end plate <NUM>, the first discharge hole <NUM> and the second discharge hole <NUM> are arranged in positions eccentric from the sub bearing hole <NUM>. The first discharge hole <NUM> and the second discharge hole <NUM> will be described later, together with a refrigerant accommodating groove <NUM>.

The fixed side wall <NUM> extends from an edge of an upper surface of the fixed end plate <NUM> in a longitudinal direction to be coupled to the frame side wall <NUM> of the main frame <NUM>. The fixed side wall <NUM> is provided with a suction port <NUM> formed through the fixed side wall <NUM> in the radial direction. As aforementioned, an end portion of the refrigerant suction pipe <NUM> inserted through the cylindrical shell <NUM> may be inserted into the suction port <NUM>.

The sub bearing hole <NUM> having a cylindrical shape may be formed through a center of the sub bearing portion <NUM> in the axial direction to radially support a lower end of the rotating shaft <NUM>.

A fixed wrap <NUM> may extend from the upper surface of the fixed end plate <NUM> toward the orbiting scroll <NUM> in the axial direction. The fixed wrap <NUM> is engaged with an orbiting wrap <NUM> which is to be described later, to define the compression chamber V. The compression chamber V includes the first compression chamber V1 defined between an inner surface of the fixed wrap <NUM> and an outer surface of the orbiting wrap <NUM>, and the second compression chamber V2 defined between an outer surface of the fixed wrap <NUM> and an inner surface of the orbiting wrap <NUM>.

The fixing wrap <NUM> may be formed in an involute shape. However, the fixed wrap <NUM> and the orbiting wrap <NUM> may be formed in various shapes other than the involute shape. For example, the fixed wrap <NUM> may be formed in an approximately elliptical shape in which a plurality of arcs having different diameters and origins are connected and an outermost curve has a major axis and a minor axis. The orbiting wrap <NUM> may also be formed in a similar manner.

The orbiting scroll <NUM> includes an orbiting end plate <NUM>, the orbiting wrap <NUM>, and a rotating shaft coupling portion <NUM>.

The orbiting end plate <NUM> is provided in a disk shape and accommodated between the frame end plate <NUM> and the fixed end plate <NUM>. An upper surface of the orbiting end plate <NUM> may be supported in the axial direction by the main frame <NUM> with interposing a back pressure sealing member (no reference numeral given) therebetween.

The orbiting wrap <NUM> extends from a lower surface of the orbiting end plate <NUM> toward the fixed end plate <NUM>, and is engaged with the fixed wrap <NUM> to define the first pressure chamber V1 and the second pressure chamber V2, both described above.

Since the orbiting wrap <NUM> has a shape corresponding to the shape of the fixed wrap <NUM> described above, a description of the orbiting wrap <NUM> will be replaced with the description of the fixed wrap <NUM>. However, an inner end portion of the orbiting wrap <NUM> is provided in a central portion of the orbiting end plate <NUM>, and the rotating shaft coupling portion <NUM> may be inserted through the central portion of the orbiting end plate <NUM> in the axial direction. Accordingly, as described above, the first discharge port <NUM> and the second discharge port <NUM> are provided in a position eccentric from a center of the orbiting scroll <NUM>, i.e., the rotating shaft coupling portion <NUM>.

The rotating shaft <NUM> may be rotatably coupled into the rotating shaft coupling portion <NUM>. An outer circumferential part of the rotating shaft coupling portion <NUM> is connected to the orbiting wrap <NUM> to define the first compression chamber V1 together with the fixed wrap <NUM> during a compression process.

The rotating shaft coupling portion <NUM> may be formed at a height at which it overlaps the orbiting wrap <NUM> on the same plane. That is, the rotating shaft coupling portion <NUM> is disposed at a height at which an eccentric portion <NUM> of the rotating shaft <NUM> overlaps the orbiting wrap <NUM> on the same plane. Accordingly, repulsive force and compressive force of refrigerant can cancel each other while being applied to the same plane based on the orbiting end plate <NUM>, and thus inclination of the orbiting scroll <NUM> due to interaction between the compressive force and the repulsive force can be suppressed.

In the drawings, an unexplained reference numeral <NUM> denotes an Oldham ring.

The scroll compressor according to the implementation of the present disclosure may operate as follows.

That is, when power is applied to the driving motor <NUM>, rotational force is generated and the rotor <NUM> and the rotating shaft <NUM> rotates accordingly. As the rotating shaft <NUM> rotates, the orbiting scroll <NUM> eccentrically coupled to the rotating shaft <NUM> performs an orbiting motion relative to the fixed scroll <NUM> by the Oldham ring <NUM>.

Then, volumes of the first pressure chamber V1 and the second pressure chamber V2 gradually decrease in a direction from an outer portion toward a central portion of each of the first and second pressure chambers V1 and V2. Then, refrigerant is sucked into the first and second pressure chambers V1 and V2 through the refrigerant suction pipe <NUM>.

Then, the refrigerant is compressed while moving along a movement trajectory of each of the first and second compression chambers V1 and V2. The compressed refrigerant is discharged into the muffler space 160a of the discharge cover <NUM> through the first and second discharge ports <NUM> and <NUM> communicating with the first and second compression chambers V1 and V2, respectively.

Then, this refrigerant flows out into an outflow passage S12 between the main frame <NUM> and the driving motor <NUM> through outflow holes (no reference numeral) in the fixed scroll <NUM> and the main frame <NUM>. The refrigerant passes through the driving motor <NUM> to move to the upper space S2 of the casing <NUM> defined above the driving motor <NUM>. Then, the refrigerant flows out of the compressor through the refrigerant discharge pipe <NUM>, and then, is sucked into the compressor through the refrigerant suction pipe <NUM> via a condenser, an expander, and an evaporator. This series of circulating process may be repeatedly performed.

In this case, a certain amount of oil is mixed in refrigerant discharged from the compression chamber V. This oil moves to the upper space S2 together with the refrigerant and is separated from the refrigerant in the upper space S2, and then, returned to the lower space S1 of the casing <NUM>, i.e., the oil storage space S11.

During assembly of the compressor, the oil described above is sealed into an inner space 110a (accurately, an upper space) of the casing <NUM> through the refrigerant discharge pipe <NUM>. However, when the refrigerant discharge pipe <NUM> is inserted deep into the upper space S2 of the casing <NUM>, compared to a speed of sealing oil through the refrigerant discharge pipe <NUM>, a moving speed of the sealed oil passing through the driving motor <NUM> may be lower. Then, a part of the sealed oil may be stagnant in the upper space S2, and thus, an inlet of the refrigerant discharge pipe <NUM> may be soaked into the sealed oil. Then, as the upper space S2 is sealed, oil stagnant in the upper space S2 may flow back or overflow through the refrigerant discharge pipe <NUM> due to pressure of the upper space S2. Thus, as oil sealing time is delayed, a manufacture process of the compressor may be delayed, and thus a manufacture cost of the compressor may be increased.

Accordingly, in this implementation, the communication hole <NUM> may be added to the inlet 116a of the refrigerant discharge pipe <NUM>. Thus, even when some oil is stagnant in the upper space S2, the oil may be suppressed from flowing back or overflow through the refrigerant discharge pipe <NUM> by leaking pressure (air) of the upper space S2.

<FIG> is a sectional view illustrating a periphery of the refrigerant discharge pipe of <FIG>. <FIG> is a cross-sectional view taken along line "IX-IX" of <FIG>. <FIG> is a longitudinal sectional view illustrating another implementation of a communication hole of <FIG>. <FIG> is a longitudinal sectional view for explaining an oil sealing process of a scroll compressor to which the refrigerant discharge pipe is applied in accordance with this implementation.

Referring to <FIG> and <FIG>, the refrigerant discharge pipe <NUM> according to this implementation is inserted through the upper shell <NUM> constituting an upper surface of the casing <NUM> to communicate with the upper space S2. In other words, the inlet 116a of the refrigerant discharge pipe <NUM> communicates with the upper space S2 to be apart from an upper end of the driving motor <NUM> by a preset space. Accordingly, refrigerant moving to the upper space S2 flows into the inlet 116a of the refrigerant discharge pipe <NUM> through the space.

In detail, as described above, the refrigerant discharge pipe <NUM> is coupled through the upper shell <NUM>, and an insertion depth H1 of the refrigerant discharge pipe <NUM> may be provided to be longer than half of a height H2 of the upper space S2. By doing so, a structure of the refrigerant discharge pipe <NUM> may be simplified and a refrigerant flow distance in the upper space S2 may be ensured to thereby minimize oil discharge.

Here, the insertion depth H1 of the refrigerant discharge pipe <NUM> may be defined as a length from an inner circumferential surface of the upper shell <NUM> to the inlet 116a of the refrigerant discharge pipe <NUM>. The height H2 of the upper space S2 may be defined as an axial distance from an upper end of the rotor <NUM> or an upper end of the rotating shaft <NUM> to an inner circumferential surface of the upper shell <NUM> axially facing the upper end of the rotor <NUM> or the rotating shaft <NUM>.

An inner diameter of the refrigerant discharge pipe <NUM> is provided to be same along a longitudinal direction of the refrigerant discharge pipe <NUM>. In other words, the inlet 116a of the refrigerant discharge pipe <NUM> may be provided to have a same inner diameter as that of the outlet 116b. Accordingly, a structure of the pipe refrigerant discharge pipe <NUM> may be simplified, and oil may be suppressed from flowing back or overflowing through the communication hole <NUM> that is to be described later.

However, the inlet 116a of the refrigerant discharge pipe <NUM> may be provided to be different from the outlet 116b of the refrigerant discharge pipe <NUM>. For example, an expanded tube portion (not shown) may be provided in the inlet 116a of the refrigerant discharge pipe <NUM>. Thus, when the refrigerant discharge pipe <NUM> extends to be adjacent to the driving motor <NUM>, a delay in refrigerant discharge in the compressor due to an excessive increase in discharge resistance may be resolved. However, in this case, the communication hole <NUM> may be provided in the expanded tube portion (not shown) and/or the refrigerant discharge pipe <NUM>. Hereinafter, an example in which the expanded tube portion is not present, i.e., the inner diameter of the inlet <NUM> is identical to that of the outlet 116b is described.

The inner diameter of the inlet 116a of the refrigerant discharge pipe <NUM> is provided to be smaller than an inner diameter of a refrigerant path (no reference numeral) of the driving motor <NUM>, i.e., a gap between the stator <NUM> and the rotor <NUM>. Thus, refrigerant moving to the upper space S2 through the refrigerant path of the driving motor <NUM> may not flow directly into the refrigerant discharge pipe <NUM> but circulate the upper space S2. Accordingly, an oil separation effect in which oil is separated from the refrigerant may be enhanced.

Referring to <FIG> and <FIG>, the communication hole <NUM> is radially inserted through a middle portion of the refrigerant discharge pipe <NUM> according to this implementation, i.e., a circumferential surface of the refrigerant discharge pipe <NUM> included in the upper space S2. One communication hole <NUM> may be provided. However, a plurality of communication holes <NUM> may be provided with a preset space therebetween in a circumferential direction. Accordingly, during sealing of oil, even when the inlet 116a of the refrigerant discharge pipe <NUM> is blocked by oil stagnant in the upper space S2, pressure of the upper space S2 quickly flows out to suppress sealing of the upper space S2.

The plurality of communication <NUM> may be provided and have a same diameter and/or a same sectional area. Thus, the communication hole <NUM> may be easily machined. However, the plurality of communication holes <NUM> may be provided to have different diameters and/or different sectional areas. An implementation in which the plurality of communication holes <NUM> have different diameters and/or sectional areas will be described later.

The communication hole <NUM> is provided to have an area larger than or same as an inlet area of the refrigerant discharge pipe <NUM>. In other words, a whole opening area of the communication hole <NUM> is provided to be larger than or same as an inlet area of the refrigerant discharge pipe <NUM>. Accordingly, even when a part of the communication hole <NUM> as well as the inlet 116a of the refrigerant discharge pipe <NUM> is blocked by being immersed in oil, pressure (air) of the upper space S2 may quickly flow out through the communication hole <NUM> by ensuring an area of the communication hole <NUM>. Further, when a large opening area of the communication hole <NUM> is provided, design freedom for a proper location of the communication hole <NUM> may be enhanced to be generally applied to various conditions.

However, a whole opening area of the communication hole <NUM> may be provided to be smaller than an inlet area of the refrigerant discharge pipe <NUM>. In this case, backflow or overflow of oil may be effectively blocked during sealing of the oil, and simultaneously, leak of the oil through the communication hole <NUM> during operation may be suppressed.

The communication hole <NUM> is provided in a position spaced apart from the inlet 116a of the refrigerant discharge pipe <NUM> by a proper distance. In other words, the communication hole <NUM> may be provided in a position such that the communication hole <NUM> is not immersed in oil that may be stagnant in the upper space S2 during oil sealing and leak of oil that has not been separated from refrigerant in the upper space S2 through the communication hole <NUM> may be minimized.

For example, referring to <FIG>, a hole height H3 of the communication hole <NUM> may be provided to be smaller than or same as half of the insertion height H1 of the refrigerant discharge pipe <NUM>. In other words, the hole height H3 defined as a distance between the inlet 116a of the refrigerant discharge pipe <NUM> to an upper end of the communication hole <NUM> may be provided to be smaller than or same as half of the insertion depth H1 defined as a length from an inner circumferential surface of the upper shell <NUM> to the inlet 116a of the refrigerant discharge pipe <NUM>. By doing so, the communication hole <NUM> may be ensured to have the hole height H3 from the driving motor <NUM> not to be immersed in oil that may be stagnant in the upper space S2 during oil sealing, and also have the insertion height H1 from the upper shell <NUM> such that leak of oil that has not been separated from refrigerant in the upper space S2 through the communication hole <NUM> may be minimized.

A position of the communication hole <NUM> may be determined in proportion to a value obtained by dividing an amount of sealed oil by a cross-sectional area of the casing <NUM>. Generally, experimental results show that an amount (f) of oil stagnant in the upper space S2 is about <NUM>% to <NUM>% of a total amount (f) of sealed oil (or an amount of rectified and sealed oil). Accordingly, the hole height H3 defined as a distance from the inlet 116a of the refrigerant discharge pipe <NUM> to an upper end of the communication hole <NUM> may be provided to be equal to or greater than <NUM> or <NUM> times a value obtained by dividing a total amount t of oil sealed into the inner space 110a of the casing <NUM> by a cross-sectional area of the casing <NUM>.

In this case, it may be desirable to provide a distance from the inlet 116a of the refrigerant discharge pipe <NUM> to the upper end of the communication hole <NUM>, i.e., the hole height H3 to be same as or smaller than <NUM> times a value obtained by dividing a total amount (f) of oil sealed into the inner space 110a of the casing <NUM> by a cross-sectional area of the casing <NUM> to suppress the oil discharge described above.

The communication hole may be provided in a circular sectional shape like <FIG>. Thus, the communication hole <NUM> may be easily formed. However, the communication hole <NUM> may be provided in a non-circular sectional shape. For example, the communication hole <NUM> may be provided to have an elliptical section or a long hole (slit) section extending to elongate in an axial direction of the rotating shaft <NUM> or in a longitudinal direction of the refrigerant discharge pipe <NUM> like <FIG>. Accordingly, the communication hole <NUM> may have an axial length greater than a circumferential length. In this case, a sectional area of the communication hole <NUM> may not be excessively enlarged, and backflow or overflow of oil may be also effectively suppressed.

In other words, when the communication hole <NUM> extends to elongate in the axial direction of the rotating shaft <NUM> or in the longitudinal direction of the refrigerant discharge pipe <NUM>, even when the sectional area of the communication hole <NUM> is same or small, a longitudinal range of the communication hole <NUM> may increase. Accordingly, during oil sealing, even when the inlet 116a of the refrigerant discharge pipe <NUM> is blocked, a section in which the refrigerant discharge pipe <NUM> may communicate with the upper space S2 is increased, backflow or overflow of oil may be suppressed. Meanwhile, a sectional area (an opening area) of the communication hole <NUM> may be maintained or reduced, and thus, discharge of oil mixed in the refrigerant during operation of the compressor may be effectively suppressed.

Referring to <FIG>, when oil is sealed through the refrigerant discharge pipe <NUM>, the oil sealed into the upper space S2 of the casing <NUM> may be stagnant in an upper surface of a driving motor, i.e., the upper space S2 to block the inlet <NUM> of the refrigerant discharge pipe <NUM>. Then, as described above, in the upper space S2, a space provided in an upper surface of oil stagnant is sealed. Thus, due to pressure (air) in the space (a remaining upper space), oil may flow back or overflow through a refrigerant discharge pipe.

However, like this implementation, as the communication hole <NUM> is provided in a middle portion of the refrigerant discharge pipe <NUM>, i.e., in a position higher than that of the stagnant oil, even when the inlet 116a of the refrigerant discharge pipe <NUM> is blocked, the upper space S2 (a remaining upper space) of the casing <NUM> may communicate with the refrigerant discharge pipe <NUM> through the communication hole <NUM>. Then, pressure (air) in the upper space S2 (the remaining upper space) quickly flows out through the communication hole <NUM> and the refrigerant discharge pipe <NUM> to relieve pressure in the upper space S2 (the remaining upper space). Accordingly, even when the inlet 116a of the refrigerant discharge pipe <NUM> is blocked, oil may be suppressed from flowing back or overflowing into the refrigerant discharge pipe <NUM>.

Further, as the refrigerant discharge pipe <NUM> is inserted deep into the upper space S2 of the casing <NUM>, a moving distance of the refrigerant in the upper space S2 may increase during operation of the compressor. Accordingly, a structure of suppressing oil leak may be simplified, and as an oil separation effect in the upper space S2 is enhanced, excessive leak of oil through the refrigerant discharge pipe <NUM> may be suppressed.

Although not illustrated in the drawing, the communication hole <NUM> may be provided in multiple layers along a longitudinal direction. In this case, the multiple layers of the communication hole <NUM> may have different sectional areas. For example, the communication hole <NUM> may have a sectional area (an opening area) gradually decreasing in a direction from the inlet 116a to the outlet 116b. Accordingly, as described above, backflow or overflow of oil that may occur during oil sealing may be suppressed, and oil leak that may occur during operation of the compressor may be relatively reduced.

By doing so, a flux path area of the driving motor may be ensured, and a number of winding wires of a stator coil and/or a coil diameter may be ensured. Thus, efficiency of the driving motor may be maintained. Accordingly, when oil is sealed through a refrigerant discharge pipe, even when an inlet of the refrigerant discharge pipe is blocked by stagnant oil, the oil may be suppressed from flowing back or overflowing through the refrigerant discharge pipe.

In addition, as the refrigerant suction pipe is inserted to be adjacent to an upper end of the driving motor as possible, the oil moving to an upper space together with refrigerant may circulate in the upper space for a long distance, and thus, be separated from the refrigerant. Accordingly, during operation of the compressor, the oil may be suppressed from being excessively leaked through the refrigerant discharge pipe without having to include a separate oil separator inside or inside the casing.

Hereinafter, a description will be given of another implementation of a communication hole.

That is, in the implementations described above, a communication hole is provided in a middle portion of a refrigerant discharge pipe. However, in some cases, a communication hole may extend longitudinally from an inlet of the refrigerant discharge pipe.

<FIG> is a longitudinal sectional view illustrating another implementation of a refrigerant discharge pipe. <FIG> is a longitudinal sectional view illustrating another implementation of a communication hole of <FIG>.

Referring to <FIG>, the refrigerant discharge tube <NUM> according to this implementation may be inserted through a center of the upper shell <NUM> to communicate with the upper space S2. The refrigerant discharge tube <NUM> is provided such that the inlet 116a has a same inner diameter as that of the inlet 116b. This is identical to the above-described implementation. Thus, with respect to a description thereof, the description about the above-described implementation may be referred to.

In addition, the refrigerant discharge tube <NUM> is spaced apart from an upper end of the driving motor <NUM> by a preset distance. This is identical to the above-described implementation. Thus, with respect to a description thereof, the description about the above-described implementation may be referred to.

In addition, the communication hole <NUM> is provided to penetrate through a circumferential surface of the refrigerant discharge pipe <NUM>, and the hole height H3 and/or a sectional area (an opening area) of the communication hole <NUM> are identical to those in the above-described implementation. Thus, with respect to a description thereof, the description about the above-described implementation may be referred to.

However, in this implementation, the communication hole <NUM> is provided in a slit shape. For example, like <FIG>, the communication hole <NUM> may extend from the inlet 116a of the refrigerant discharge pipe <NUM> along a longitudinal direction in correspondence with a preset length. In other words, the communication hole <NUM> may have a structure such that a lower end is cut at an end of the refrigerant discharge pipe <NUM> and an upper end is connected to a middle portion of the refrigerant discharge pipe <NUM> in a circumferential direction to thereby limit a slit length. Accordingly, the communication hole <NUM> may have an axial length greater than a circumferential length.

One communication hole <NUM> may be provided, or a plurality of communication holes <NUM> may be circumferentially provided to have a present space therebetween. When a plurality of communication holes <NUM> are provided, the plurality of communication holes <NUM> may be provided to have a same shape and/or a same sectional area. Accordingly, the communication hole <NUM> may be easily formed, and backflow or overflow of oil may be also effectively suppressed.

The communication hole <NUM> may be provided to have a same sectional area along a longitudinal direction (an axial direction of a rotating shaft). Thus, the communication hole <NUM> may be easily machined.

As described above, when the communication hole <NUM> has a slit shape, the communication hole <NUM> has a smaller circumferential width compared to when the communication hole <NUM> in a circular shape has a same sectional area (an opening area). Then, backflow or overflow of oil that may occur during oil sealing may be suppressed, and as an upper area of the communication hole <NUM> having a slit shape is smaller than that of the communication hole <NUM> having a circular shape, oil leak that may occur during operation of the compressor may be relatively reduced.

The communication hole <NUM> may have different sectional areas along a longitudinal direction. For example, as illustrated in <FIG>, the communication hole <NUM> may have a sectional area (an opening area) gradually decreasing in a direction from the inlet 116a to the outlet 116b. Accordingly, as described above, backflow or overflow of oil that may occur during oil sealing may be suppressed, and oil leak that may occur during operation of the compressor may be relatively reduced.

Hereinafter, a description will be given of another implementation of a structure of prevention oil leak.

That is, in the above-described implementation, a height of a communication hole is optimized to suppress oil leak through the communication hole. However, in some cases, an oil blocking portion may be provided near a communication hole to suppress oil leak.

<FIG> is a longitudinal sectional view illustrating an implementation in which an oil blocking portion is included near the refrigerant discharge pipe.

Referring to <FIG>, the refrigerant discharge tube <NUM> according to this implementation may be inserted through a center of the upper shell <NUM> to communicate with the upper space S2. The refrigerant discharge tube <NUM> is provided such that the inlet 116a has a same inner diameter as that of the inlet 116b. This is identical to the above-described implementations of <FIG>, <FIG>, <FIG>, and <FIG>. Thus, with respect to a description thereof, the description about the above-described implementations may be referred to.

In addition, the refrigerant discharge tube <NUM> is spaced apart from an upper end of the driving motor <NUM> by a preset distance. This is identical to the above-described implementations of <FIG>, <FIG>, <FIG>, and <FIG>. Thus, with respect to a description thereof, the description about the above-described implementations may be referred to.

In addition, the communication hole <NUM> is provided to penetrate through a circumferential surface of the refrigerant discharge pipe <NUM>, and the hole height H3 and/or a sectional area (an opening area) of the communication hole <NUM> are identical to those in the above-described implementations of <FIG>, <FIG>, <FIG>, and <FIG>. Thus, with respect to a description thereof, the description about the above-described implementations may be referred to.

However, in this implementation, an oil blocking portion <NUM> surrounding the refrigerant discharge pipe <NUM> may be further included. For example, the oil blocking portion <NUM> may be provided to have a cylindrical shape to surround the refrigerant discharge pipe <NUM> from an outer circumference of refrigerant discharge pipe <NUM> to be apart with a preset space therebetween. In other words, a space through refrigerant may move may be ensured between an inner circumferential surface of the oil blocking portion <NUM> and an outer circumferential surface of the refrigerant discharge pipe <NUM>.

An end of the oil blocking portion <NUM> may be post-coupled to or extend integrally with an inner circumferential surface of the upper shell <NUM>. When the oil blocking portion <NUM> is post-coupled to the upper shell <NUM>, a degree of freedom with respect to a material or thickness of the oil blocking portion <NUM> may be increased. In other words, when the oil blocking portion <NUM> is post-coupled, the oil blocking portion <NUM> may include a light material such as plastic other than metal as needed. On the other hand, when the oil blocking portion <NUM> is provided integrally with the upper shell <NUM>, the oil blocking portion <NUM> may be easily provided, and thus, an increase in a manufacture cost may be suppressed.

A lower end 117a of the oil blocking portion <NUM> may be provided to elongate toward an upper end of the driving motor <NUM> as possible. In other words, a length H4 of the oil blocking portion <NUM> may be provided such that at least of the oil blocking portion <NUM> radially overlaps the communication hole <NUM>, the length H4 being defined as a length from an inner circumferential surface to an axial lower end of the upper shell <NUM>. Thus, during oil sealing, oil sealing is not delayed due to the oil blocking portion <NUM>, and the oil blocking portion <NUM> blocks oil at a circumferential portion of the communication hole <NUM>. Accordingly, oil in the upper space S2 may be suppressed from being leaked together with refrigerant through the communication hole <NUM>.

In addition, the lower end 117a of the oil blocking portion <NUM> may be provided at a height less than or same as that of the inlet 116a of the refrigerant discharge pipe <NUM> with reference to an inner circumferential surface of the upper shell <NUM>. In other words, the lower end 117a of the oil blocking portion <NUM> may have a length not to overlap the inlet 116a of the refrigerant discharge pipe <NUM>. Accordingly, during operation of the compressor, discharge resistance with respect to refrigerant moving toward the refrigerant discharge pipe <NUM> is reduced. Thus, deterioration of efficiency of the compressor that may be caused by the oil blocking portion <NUM> may be suppressed.

The oil blocking portion <NUM> may be provided in a plate or mesh shape. When the oil blocking portion is provided to have a plate shape, the oil blocking portion <NUM> may have a closed plate shape or a plate shape including fine through-holes like a mesh. Accordingly, the refrigerant and oil in the upper space S2 may avoid the oil blocking portion <NUM> and move toward the refrigerant discharge pipe <NUM> or may pass through the fine through-holes in the oil blocking portion <NUM> and move toward the refrigerant discharge pipe <NUM>, to thereby facilitate oil separation. In this implementation, an example in which the oil blocking portion <NUM> is provided to have a closed plate shape.

As described above, when the oil blocking portion <NUM> is provided to surround the refrigerant discharge pipe <NUM> at an outer circumference of the refrigerant discharge pipe <NUM>, refrigerant that moved to the upper space S2 during operation of the compressor may not move directly to the refrigerant discharge pipe <NUM>, but bypass the oil blocking portion <NUM> and move to the refrigerant discharge pipe <NUM>. Accordingly, as a moving distance of refrigerant mixed with oil is increased, an oil separation effect of separating the oil from the refrigerant may be enhanced.

In addition, in this case, since the communication hole <NUM> in the refrigerant discharge pipe <NUM> opens regardless of the oil blocking portion <NUM>, even when the inlet 116a of the refrigerant discharge pipe <NUM> is immersed in and blocked by oil stagnant in the upper space S2 during oil sealing, pressure (air) in the upper space S2 may move to the refrigerant discharge pipe <NUM> through a portion between the refrigerant discharge pipe <NUM> and the oil blocking portion <NUM>, and through the communication hole <NUM>. Accordingly, excessive increase of the pressure in the upper space S2 is suppressed, and thus, sealed oil may be suppressed from flowing back or overflowing through the refrigerant discharge pipe <NUM>.

Hereinafter, a description will be given of another implementation of a compressor to which a communication hole is applied in a refrigerant discharge pipe.

That is, in the above-described implementation, a communication hole is applied to a refrigerant discharge pipe of a scroll compressor. However, in some cases, a communication hole may be applied to a refrigerant discharge pipe of a rotary compressor.

<FIG> is a longitudinal sectional view illustrating a rotary compressor to which a refrigerant discharge pipe is adopted in accordance with this implementation.

Referring to <FIG>, the rotary compressor according to this implementation may include a casing <NUM>, a driving motor <NUM>, the compression part C, a refrigerant suction pipe <NUM>, and a refrigerant discharge pipe <NUM>. The casing <NUM> and the driving motor <NUM> are almost identical to the casing <NUM> and the driving motor <NUM> in the scroll compressor described above. Thus, a description thereof is not provided here.

The compression part C may include a main bearing <NUM>, a sub bearing <NUM>, a cylinder <NUM>, a roller <NUM>, and a vane <NUM>. The vane <NUM> may be slidably inserted into the cylinder <NUM> or the roller <NUM> according to a type of a compressor. In this implementation, an example in which the vane <NUM> is inserted into the roller <NUM> is illustrated. This implementation discloses a concentric rotary compressor. Thus, a detailed description thereof will not be provided here.

The refrigerant suction pipe <NUM> is inserted through the cylinder <NUM> to communicate with the compression chamber V. This is similar to the refrigerant suction pipe <NUM> in the scroll compressor described above, as well as in a general rotary compressor. Therefore, a detailed description thereof will not be provided here.

The refrigerant discharge pipe <NUM> is inserted through an upper end of the casing <NUM>, i.e., a center of the upper shell <NUM> to extend toward an upper surface of the driving motor <NUM>. A communication hole <NUM> communicating with the upper space S2 of the casing <NUM> is provided in a middle portion of the refrigerant discharge pipe <NUM>. A basic configuration such as an insertion depth and an inner diameter of the refrigerant discharge pipe <NUM> and an effect thereof are identical to those in the about the above-described implementation. Thus, with respect to a description thereof, the description about the above-described implementation may be referred to.

Even when an inlet of the refrigerant discharge pipe <NUM> is blocked during oil sealing, the communication hole <NUM> suppresses sealing of the upper space S2 to suppress backflow or overflow of oil. A shape, a height, a sectional area, etc. of the communication hole <NUM> according to this implementation are identical to those in the scroll compressor in the above-described implementations. Thus, with respect to a description thereof, the description about the above-described implementations may be referred to.

Claim 1:
A compressor comprising:
a casing (<NUM>);
a driving motor (<NUM>) provided in an inner space of the casing (<NUM>);
a compression part (C) disposed in the inner space of the casing (<NUM>) to compress refrigerant;
a rotating shaft (<NUM>) connecting the driving motor (<NUM>) to the compression part (C) to transmit driving force of the driving motor (<NUM>) to the compression part (C);
a refrigerant discharge pipe (<NUM>) comprising an inlet and an outlet at both ends and coupled through a center of the upper shell (<NUM>) of the casing (<NUM>) in an axial direction of the rotating shaft (<NUM>),
the inlet (116a) communicating with the inner space of the casing (<NUM>) to be apart from an upper end of the driving motor (<NUM>) by a preset space,
wherein the refrigerant discharge pipe (<NUM>) is provided with at least one communication hole (<NUM>) between the inlet (116a) and the outlet (116b), the at least one communication hole (<NUM>) penetrating between an outer circumferential surface and an inner circumferential surface of the refrigerant discharge pipe (<NUM>); and
an oil blocking portion (<NUM>) which surrounds the refrigerant discharge pipe (<NUM>) and is apart from the refrigerant discharge pipe (<NUM>) by a preset distance,
characterized in that the oil blocking portion (<NUM>) is provided such that at least a portion of the oil blocking portion (<NUM>) radially overlaps the communication hole (<NUM>), and a lower end of the oil blocking portion (<NUM>) has a height less than or same as that of the inlet (116a) of the refrigerant discharge pipe (<NUM>) with reference to an inner surface of an upper shell (<NUM>) of the casing (<NUM>).