Patent Description:
A scroll compressor is configured such that an orbiting scroll and a non-orbiting scroll are engaged with each other and a pair of compression chambers is formed while the orbiting scroll performs an orbiting motion with respect to the non-orbiting scroll.

The compression chamber includes a suction pressure chamber formed at an outer side, an intermediate pressure chamber continuously formed toward a central portion from the suction pressure chamber while gradually decreasing in volume, and a discharge pressure chamber connected to the center of the intermediate pressure chamber. Typically, the suction pressure chamber is formed through a side surface of the non-orbiting scroll, the intermediate pressure chamber is sealed, and the discharge pressure chamber is formed through an end plate of the non-orbiting scroll.

Scroll compressors may be classified into a low-pressure type and a high-pressure type according to a path through which refrigerant is suctioned. The low-pressure type is configured such that a refrigerant suction pipe is connected to an inner space of a casing to guide suction refrigerant of low temperature to flow into a suction pressure chamber via the inner space of the casing. On the other hand, the high-pressure type is configured such that the refrigerant suction pipe is connected directly to the suction pressure chamber to guide refrigerant to flow directly into the suction pressure chamber without passing through the inner space of the casing.

A bottom-compression type scroll compressor is widely configured as a bottom-compression high-pressure type compressor in which a compression part including a fixed scroll and an orbiting scroll is located below a motor part that transmits power to turn the orbiting scroll, such that refrigerant gas directly supplied into the compression part is compressed and then flows to an upper space within a case.

Meanwhile, Patent Document <NUM> (<CIT>) discloses a compressor having an oil temperature adjustment function.

Patent Document <NUM> discloses a compressor that includes a casing defining an accommodating space therein to store oil, a compression part accommodated in the casing to compress refrigerant, an oil heating unit for heating the oil inside the casing, the oil heating unit provided with a high-temperature refrigerant passage having one side branched from a discharge side of the compression part and another side connected to a downstream side of a condenser via the inside of the casing so as to be in contact with the oil inside the casing,, and an oil cooling unit for cooling the oil inside the casing, the oil cooling unit provided with a low-temperature refrigerant passage having one side connected to a downstream side of an expander and another side connected to the casing from the outside of the casing so as to be in contact with the oil inside the casing.

As described above, the compressor of Patent Document <NUM> has an oil-temperature adjustment function capable of suppressing lubrication failure due to an excessive change in oil temperature.

In particular, a portion of a discharge refrigerant pipe was branched to be disposed in an oil storage space, to heat oil through a valve when necessary. Also, a portion of a suction refrigerant pipe was branched to be disposed in the oil storage space, to cool oil through a valve when necessary. In these two cases, the temperature of the oil was adjusted.

As described above, the compressor of Patent Document <NUM> discloses a method of cooling or heating oil in an oil storage space by disposing suction and discharge refrigerant pipes in the oil storage space.

However, in the compressor using the method of cooling or heating the oil in the oil storage space by arranging the suction and discharge refrigerant pipes in the oil storage space, as disclosed in Patent Document <NUM>, oil is left in low temperature or oil superheat is not secured at the beginning of operation, which causes the oil to flow in a low-viscosity state. When the oil flows in the low-viscosity state, problems such as damage on bearings inside the compressor and lowering of an oil level are caused.

Therefore, there is a need to develop a scroll compressor that is capable of adjusting temperature of oil without using a pipe.

<CIT> discloses a scroll compressor having a discharge cover attached to a lower surface of a fixed scroll. <CIT> discloses a compressor having a compression unit located below a motor unit. <CIT> discloses a scroll compressor that is capable of separating refrigerant and oil within a casing and of minimizing the driving of the oil out of the casing along with the refrigerant.

The present disclosure has been invented to solve the above problems, and one aspect of the present invention is to provide a scroll compressor capable of adjusting temperature of oil without using a pipe.

Another aspect of the present invention is to provide a scroll compressor capable of adjusting temperature of oil in an oil storage space by transferring heat through an oil feeder.

Still another aspect of the present invention is to provide a scroll compressor capable of preventing oil from being supplied in a low-viscosity state.

Still another aspect of the present invention is to provide a scroll compressor in which oil inside an oil storage space is stirred with being in direct contact with discharge refrigerant.

Still another aspect of the present invention is to provide a scroll compressor capable of operating at an oil circulation ratio (OCR) optimized for a preset operation condition.

Still another aspect of the present invention is to provide a scroll compressor having a structure for reducing scattering of oil due to injected refrigerant while adjusting temperature of oil in an oil storage space.

Still another aspect of the present invention is to provide a scroll compressor capable of improving circulation in a compressor, in particular, circulation of recovered oil in an upper side of the compressor by forming a gas drain hole for resolving differential pressure in a lower side of the compressor near an oil storage space.

In order to solve those aspects according to the invention, there is provided a scroll compressor that includes a casing having an oil storage space, a fixed scroll disposed inside the casing, an orbiting scroll disposed on one side of the fixed scroll and performing an orbiting motion relative to the fixed scroll so as to form a compression chamber, a discharge cover coupled to another side opposite to the one side of the fixed scroll and having a cover bottom portion, and an oil feeder coupled to the cover bottom portion to face a direction opposite to the fixed scroll, to communicate with the oil storage space. The cover bottom portion comprises a discharge hole formed to face and communicate with the oil storage space. The discharge hole is disposed at a portion of the cover bottom surface, which is disposed at a radially inner side of the oil feeder, to communicate with an inner space of the oil feeder.

With the configuration, the scroll compressor of the present disclosure can adjust temperature of oil in the oil storage space without using a pipe.

In addition, as the discharge hole of the discharge cover is formed through the cover bottom surface located at the inner side of the oil feeder, scattering of oil due to injected refrigerant can be reduced while adjusting temperature of oil in the oil storage space.

The discharge cover may further include a cover side portion extending from the cover bottom surface toward the fixed scroll, and a discharge space defined by the cover bottom surface, the cover side portion, and the fixed scroll.

Accordingly, refrigerant collected in the discharge space is moved to the oil storage space through the discharge hole. The oil in the storage space can thus be brought into direct contact with and stirred with a discharged refrigerant.

The cover bottom surface may be provided with a refrigerant guide member being adjacent to the discharge hole, and extending to overlap the discharge hole in a radial direction to collide with refrigerant passing through the discharge hole.

With the configuration, the refrigerant guide member extends in a predetermined direction to guide a flow of refrigerant in the predetermined direction.

The oil feeder may include an oil suction pipe coupled through the discharge cover, and a blocking member accommodating the oil suction pipe to block an introduction of foreign substances.

The scroll compressor may further comprises a pressure reducing pin disposed in a passage along which refrigerant flows from the discharge cover toward the oil storage space. Preferably, the pressure reducing pin may be arranged to prevent direct collision of high-pressure refrigerant with the blocking member.

The scroll compressor may further include a main frame fixedly disposed on an opposite side of the fixed scroll with the orbiting scroll interposed therebetween. The main frame and the fixed scroll may be provided with a gas drain hole through which gas inside the oil storage space flows out of the casing.

As such, as the gas drain hole is formed in an inner circumference of a balance weight, refrigerant of high pressure in the oil storage space can flow along the inner circumference of the balance weight with relatively low pressure so as to be discharged to outside through the refrigerant discharge pipe disposed inside the casing, thereby relieving differential pressure in a lower portion of the compressor near the oil storage space.

The gas drain hole may include an upper communication portion formed through an upper surface of the main frame, and a lower communication portion communicating with the oil storage space such that refrigerant gas in the oil storage space partially flows to the upper communication portion.

The gas drain hole may further include a middle communication portion formed in an upper portion of the main frame in a horizontal direction, i.e. in a direction crossing the upper communication portion, such that the upper communication portion and the lower communication portion communicate with each other via the middle communication portion.

The main frame may include a frame side wall extending in a cylindrical shape from an edge of a lower side surface thereof, and the fixed scroll may include a fixed side wall formed in an annular shape on a side portion thereof and coupled to the frame side wall to face the frame side wall in a vertical direction. The lower communication portion may include a first communication hole formed in the fixed side wall in the vertical direction, and a second communication hole formed in the frame side wall in the vertical direction, and having an upper portion communicating with the middle communication portion and a lower portion communicating with the first communication hole.

The scroll compressor may further include a driving motor to generate rotational force by receiving external power to pivot the orbiting scroll. A balance weight that is disposed between the driving motor and the main frame and extends by a predetermined angle in a circumferential direction may be coupled to the driving motor so as to be rotatable by rotation of the driving motor. The upper communication portion may further be disposed to communicate with a space located radially inside the balance weight.

The main frame may include a main bearing accommodating portion protruding from an upper surface thereof and having an inner circumference on which a bearing is fitted. The upper communication portion may further be disposed to communicate with a space between an inner circumferential surface of the balance weight and an outer circumferential surface of the main bearing accommodating portion.

According to another example, the main frame may include a frame end plate defining an upper surface, and a main bearing accommodating portion protruding from the frame end plate and having an inner circumference on which a bearing is fitted. The upper communication portion may include a main communication hole formed in the frame end plate in the vertical direction. The main bearing accommodating portion may communicate with the space disposed between the inner circumferential surface of the balance weight and the outer circumferential surface of the main bearing accommodating portion.

In order to solve those aspects according to another implementation, there is provided a scroll compressor that may include a casing having an oil storage space, a fixed scroll disposed inside the casing, an orbiting scroll disposed on one side of the fixed scroll and performing an orbiting motion relative to the fixed scroll so as to form a compression chamber, and a main frame fixedly disposed on an opposite side of the fixed scroll with the orbiting scroll interposed therebetween. The main frame and the fixed scroll may be provided with a gas drain hole through which gas inside the oil storage space flows out of the casing.

As such, as the gas drain hole is formed in an inner circumference of a balance weight, refrigerant of high pressure in the oil storage space can flow along the inner circumference of the balance weight with relatively low pressure so as to be discharged to outside through the refrigerant discharge pipe inside the casing, thereby relieving differential pressure in a lower portion of the compressor near the oil storage space.

According one example disclosed herein, the gas drain hole may include an upper communication portion formed through an upper surface of the main frame, and a lower communication portion communicating with the oil storage space such that refrigerant gas in the oil storage space partially flows to the upper communication portion.

The gas drain hole may further include a middle communication portion formed in an upper surface of the main frame in a direction crossing the upper communication portion such that the upper communication portion and the lower communication portion communicate with each other.

According another example disclosed herein, the main frame may include a frame side wall extending in a cylindrical shape from an edge of a lower side surface thereof, and the fixed scroll may include a fixed side wall formed in an annular shape on a side portion thereof and coupled to the frame side wall to face the frame side wall in a vertical direction. The lower communication portion may include a first communication hole formed in the fixed side wall in the vertical direction, and a second communication hole formed in the frame side wall in the vertical direction, and having an upper portion communicating with the middle communication portion and a lower portion communicating with the first communication hole.

The scroll compressor further includes a driving motor to generate rotational force by receiving external power to pivot the orbiting scroll. A balance weight that is disposed between the driving motor and the main frame and extends by a predetermined angle in a circumferential direction may be coupled to the driving motor so as to be rotatable by rotation of the driving motor. The upper communication portion may further be disposed in an inner circumferential space of the balance weight.

The main frame may include a frame end plate defining an upper surface, and a main bearing accommodating portion protruding from the frame end plate and having an inner circumference on which a bearing is fitted, and the upper communication portion may include a main communication hole formed in the frame end plate in the vertical direction, and an upper discharge space communicating with the main communication hole and disposed between an inner circumference of the balance weight and the main bearing accommodating portion.

The scroll compressor further includes a discharge cover coupled to another side opposite to the one side of the fixed scroll and having a cover bottom portion, and the cover bottom portion includes a discharge hole communicating with the discharge space and the oil storage space.

The scroll compressor further includes an oil feeder coupled to the cover bottom surface to face a direction opposite to the fixed scroll, to communicate with the oil storage space, and the discharge hole is formed in the cover bottom surface disposed at an inner side of an inner circumference of the oil feeder so as to communicate with the inner side of the oil feeder.

In an example which does not fall within the scope of the claims, the scroll compressor may further include an oil feeder coupled to the cover bottom surface to face a direction opposite to the fixed scroll, to communicate with the oil storage space, and the discharge hole may be formed in the cover bottom surface disposed at an outer side of an outer circumference of the oil feeder so as to communicate with the oil storage space.

Hereinafter, a scroll compressor <NUM> according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, a description of some components may be omitted to clarify features of the present invention.

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 <NUM> according to an implementation of the present disclosure, that is, a direction toward a motor part when viewed based on the motor part 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 motor part and the compression part.

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

In addition, a description will be given of a bottom-compression type scroll compressor <NUM> in which a motor part and a compression part are arranged vertically in an axial direction and the compression part is located below the motor part.

In addition, a description will be given of a bottom-compression high-pressure type scroll compressor in which a refrigerant suction pipe defining a suction passage is directly connected to a compression part and a refrigerant discharge pipe <NUM> communicates with an inner space of a casing <NUM>.

<FIG> is a schematic diagram illustrating a refrigeration cycle device including a scroll compressor <NUM> in accordance with an implementation of the present disclosure.

Referring to <FIG>, a refrigeration cycle device including the scroll compressor <NUM> according to the present disclosure is configured such that the scroll compressor <NUM>, a condenser <NUM>, an expansion apparatus (or expander) <NUM>, and an evaporator <NUM> form a closed loop.

The condenser <NUM>, the expansion apparatus <NUM>, and the evaporator <NUM> is sequentially connected to a refrigerant discharge pipe <NUM> of the scroll compressor <NUM>. Also, a discharge side of the evaporator <NUM> is connected to a suction side of the scroll compressor <NUM>.

One side of a refrigerant suction pipe <NUM> is connected to an accumulator <NUM>. In addition, the accumulator <NUM> is connected to an outlet side of the evaporator <NUM> through a refrigerant pipe.

Accordingly, while refrigerant flows from the evaporator <NUM> to the accumulator <NUM>, liquid refrigerant is separated in the accumulator <NUM>, and only gaseous refrigerant is directly introduced into a compression chamber through the refrigerant suction pipe <NUM>.

Accordingly, the refrigerant compressed in the scroll compressor <NUM> is discharged toward the condenser <NUM>, and then sucked back into the scroll compressor <NUM> sequentially through the expansion apparatus <NUM> and the evaporator <NUM>. The series of processes is repeatedly carried out.

<FIG> is a sectional view illustrating a scroll compressor according to the present disclosure.

Hereinafter, the structure of the scroll compressor <NUM> will be described with reference to <FIG>.

The scroll compressor <NUM> may be an inverter type scroll compressor. The scroll compressor <NUM> can operate in the range from a low speed to a high speed. The scroll compressor <NUM> may also be a high-pressure type and a bottom-compression type.

According to an example, the scroll compressor <NUM> includes a casing <NUM>, a fixed scroll <NUM>, an orbiting scroll <NUM>, a discharge cover <NUM>, and an oil feeder <NUM>.

The casing <NUM> has an oil storage space S11. As an example, a driving motor <NUM> may be disposed in an upper portion of the casing <NUM>, and a main frame <NUM>, the orbiting scroll <NUM>, the fixed scroll <NUM>, and the discharge cover <NUM> may be sequentially disposed below the driving motor <NUM>.

The driving motor <NUM> may configure the motor part that converts external electrical energy into mechanical energy.

In addition, the main frame <NUM>, the orbiting scroll <NUM>, the fixed scroll <NUM>, and the discharge cover <NUM> may configure a compression part that compresses refrigerant by receiving the mechanical energy generated in the driving motor <NUM>.

Referring to <FIG>, an example in which the motor part is coupled to an upper end of a rotating shaft <NUM> to be explained later, and the compression part is coupled to a lower end of the rotating shaft <NUM> is illustrated. That is, the scroll compressor <NUM> may have a lower compression type structure.

In summary, the scroll compressor <NUM> includes the motor part and the compression part, and the motor part and the compression part are accommodated in an inner space 110a of the casing <NUM>.

The casing <NUM> 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 both ends open.

The upper shell <NUM> may be coupled to an upper end portion of the cylindrical shell <NUM>, and the lower shell <NUM> may be coupled to a lower end portion of the cylindrical shell <NUM>.

That is, both the upper and lower end portions of the cylindrical shell <NUM> are coupled to the upper shell <NUM> and the lower shell <NUM>, respectively, in a covering manner. The cylindrical shell <NUM>, the upper shell <NUM> and the lower shell <NUM> that are coupled together define the inner space 110a of the casing <NUM>. At this time, the inner space 110a is sealed.

The sealed inner space 110a of the casing <NUM> is divided into a lower space S1, an upper space S2, an oil storage space S11, and a discharge space S3.

The lower space S1 and the upper space S2 are defined in an upper side of the main frame <NUM> and the oil storage space S11 and the discharge space S3 are defined in a lower side of the main frame <NUM>.

The lower space S1 indicates a space defined between the driving motor <NUM> and the main frame <NUM>, and the upper space S2 indicates a space above the driving motor <NUM>. In addition, the oil storage space S11 indicates a space below the discharge cover <NUM>, and the discharge space S3 indicates a space defined between the discharge cover <NUM> and the fixed scroll <NUM>.

One end of the refrigerant suction pipe <NUM> is coupled through a side surface of the cylindrical shell <NUM>. Specifically, the one end of the refrigerant suction pipe <NUM> is coupled through the cylindrical shell <NUM> in a radial direction of the cylindrical shell <NUM>.

The refrigerant suction pipe <NUM> penetrates through the cylindrical shell <NUM> to be directly coupled to a suction through hole <NUM> (<FIG>) of the fixed scroll <NUM>. Accordingly, refrigerant can be introduced into a compression chamber V through the refrigerant suction pipe <NUM>.

The accumulator <NUM> is coupled to another end, different from the one end, of the refrigerant suction pipe <NUM>.

The accumulator <NUM> is connected to an outlet side of the evaporator <NUM> through a refrigerant pipe. Accordingly, while refrigerant flows from the evaporator <NUM> to the accumulator <NUM>, liquid refrigerant is separated in the accumulator <NUM>, and only gaseous refrigerant is directly introduced into a compression chamber through the refrigerant suction pipe <NUM>.

A refrigerant discharge pipe <NUM> is coupled through an upper portion of the upper shell <NUM> to communicate with the inner space 110a of the casing <NUM>. Accordingly, refrigerant discharged from the compression part into the inner space 110a of the casing <NUM> flows to the condenser <NUM> through the refrigerant discharge pipe <NUM>.

The configuration of the fixed scroll <NUM>, the orbiting scroll <NUM>, the discharge cover <NUM>, and the oil feeder <NUM> will be described later.

<FIG> is a conceptual diagram illustrating a flow of lubricating oil in the rotating shaft and the compression part in the scroll compressor according to the present disclosure, <FIG> is a sectional view illustrating one example of a flow of refrigerant in the scroll compressor according to the present disclosure, <FIG> is a conceptual diagram illustrating oil and refrigerant before turning on a related art scroll compressor, and <FIG> is a conceptual diagram illustrating oil and refrigerant right after turning on the related art scroll compressor. Also, <FIG> is a conceptual diagram illustrating a state just before securing oil superheat in the related art scroll compressor.

Hereinafter, a description will be given of a flow of oil and refrigerant in the scroll compressor <NUM> and states before and immediately after turning on the related art scroll compressor, and a state immediately before securing oil superheat of the related art scroll compressor, with reference to <FIG>.

<FIG> illustrates an example of the scroll compressor <NUM> of the present disclosure, in which oil for lubricating a sliding part between the rotating shaft <NUM> and the compression part is used, and the lubricating oil is suctioned from the oil storage space S11 to be supplied to bearings <NUM>, <NUM>, <NUM> disposed between each of the orbiting scroll <NUM>, the fixed scroll <NUM>, and the main frame <NUM> and the rotating shaft <NUM>, and the compression part.

In particular, in the example of <FIG>, oil supplied through an internal oil passage <NUM> of the rotating shaft <NUM> is supplied to the compression part through a first main oil feeding passage 1326a and a second main oil feeding passage 1326b provided in the main frame <NUM>, and a first fixed oil feeding passage 1426a, a second main oil feeding passage 1426b, and a third main oil feeding passage 1426c provided in the fixed scroll <NUM>.

The scroll compressor <NUM> of the present disclosure has a differential pressure oil feeding structure for feeding oil of high pressure through the rotating shaft <NUM>.

In addition, <FIG> illustrates a flow of refrigerant discharged from the compression part. Refrigerant discharged from a compression chamber toward the discharge cover <NUM> is moved to an upper side of the casing <NUM> to flow out of the casing <NUM> through the refrigerant discharge pipe <NUM>. The refrigerant also contains some oil supplied to the compression unit in <FIG>. Oil separated in the inner space provided at an upper side within the casing <NUM> flows into the oil storage space S11 through an oil return groove 1211b and is accommodated therein.

In addition, as will be described later, a discharge hole <NUM> is formed in a cover bottom surface <NUM> of the discharge cover <NUM>, and some of the refrigerant discharged from the compression chamber are supplied into the oil storage space S11 through the discharge hole <NUM>. This can result in adjusting temperature of oil.

On the other hand, <FIG> illustrates an example in which oil and refrigerant exist in the oil storage space S11 before starting the operation of the compressor. Some of the refrigerant in the oil storage space S11 are mixed with stacked oil and the other refrigerant is on the top of the oil.

Also, immediately after starting the operation of the compressor, liquid refrigerant in a low-viscosity state without securing discharge superheat is accumulated in the compression part of the compressor. This example is illustrated in <FIG>. Immediately after the compressor is turned on, liquid refrigerant is mixed in a saturated low-viscosity state with oil of low temperature. This oil may cause damages on bearings between each of the orbiting scroll, the fixed scroll, and the main frame and the rotating shaft, and lowering of an oil level.

In addition, <FIG> illustrates a state that oil is heated in response to the turn-on of the compressor but oil superheat has not been secured yet. In this state, an amount of oil is reduced due to evaporation of oil droplets and thereby an oil level is lowered.

The fixed scroll <NUM> is disposed inside the casing <NUM>. The orbiting scroll <NUM> is disposed on one side of the fixed scroll <NUM> to be pivotable, and the fixed scroll <NUM> forms a compression chamber together with the orbiting scroll <NUM>.

In addition, the discharge cover <NUM> is disposed on another side of the fixed scroll <NUM>, opposite to the one side.

The fixed scroll <NUM> includes a fixed wrap <NUM>. The fixed scroll <NUM> may further include a sub bearing hole <NUM>.

The fixed scroll <NUM> may include a fixed end plate <NUM>, a fixed side wall <NUM>, a sub bearing portion <NUM>, and a fixed wrap <NUM>. A detailed structure of the fixed scroll <NUM> will be described later.

The orbiting scroll <NUM> performs an orbiting motion relative to the fixed scroll <NUM>, and is engaged with the fixed wrap <NUM> to form the compression chamber.

For example, the orbiting scroll <NUM> may include an orbiting wrap <NUM> engaged with the fixed wrap <NUM> of the fixed scroll <NUM> to form a compression chamber, and an orbiting end plate <NUM> connected at one end of the orbiting wrap <NUM> and having a predetermined width. A detailed description of the orbiting scroll <NUM> will be described later.

The rotating shaft <NUM> may be disposed inside the casing <NUM> in one direction and disposed on inner circumferences of the fixed scroll <NUM> and the orbiting scroll <NUM> to transfer rotational force to enable the orbiting scroll <NUM> to perform the orbiting motion.

The discharge cover <NUM> is coupled to the another side of the fixed scroll <NUM>, which is opposite to the one side thereof forming the compression chamber. The discharge cover <NUM> also has a cover bottom surface <NUM> defining a lower portion of the discharge cover <NUM>.

A discharge hole <NUM> is formed through the cover bottom surface <NUM>.

The oil feeder <NUM> is coupled to the cover bottom surface <NUM> to face an opposite direction to the fixed scroll <NUM>, so as to communicate with the oil storage space S11.

The discharge hole <NUM> is formed through a portion of the cover bottom surface <NUM>. The portion is located at an inner side of an inner circumference of the oil feeder <NUM>. As the discharge hole <NUM> is formed through the portion of the cover bottom surface <NUM> located at the inner side of the inner circumference of the oil feeder <NUM>, it can communicate with an inside of the oil feeder <NUM>.

In the related art compressor in which suction and discharge refrigerant pipes are disposed in the oil storage space S11 to cool or heat oil, the oil is left in low temperature or oil superheat is not secured at the beginning of operation, which causes the oil to flow in a low-viscosity state. In particular, when the oil flows in the low-viscosity state, bearings in the compressor may be damaged and an oil level may be lowered.

The scroll compressor <NUM> of the present disclosure can adjust temperature of oil without using a pipe, and refrigerant collected in the discharge space S3 is moved to the oil storage space S11 through the discharge hole <NUM>. Accordingly, oil in the oil storage space S11 can be directly in contact with discharge refrigerant and stirred, and the temperature of the oil in the oil storage space S11 can be increased more rapidly at the beginning of the operation of the scroll compressor <NUM>.

In addition, as the discharge hole <NUM> of the discharge cover <NUM> is formed through the cover bottom surface <NUM> located at the inner side of the oil feeder <NUM>, scattering of oil due to injected refrigerant can be reduced while adjusting the temperature of the oil in the oil storage space S11.

A more detailed structure in which the discharge hole <NUM> is formed through the lower surface of the cover <NUM> to communicate with the inner side of the oil feeder <NUM>, so as to obtain the aforementioned effects will be described later.

Referring to <FIG>, a high-pressure and bottom-compression type scroll compressor <NUM> (hereinafter, referred to as a scroll compressor <NUM>) according to an implementation includes a driving motor <NUM> constituting a motor unit 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> sequentially disposed below the driving motor <NUM>. In general, the driving motor <NUM> constitutes a motor part, and the main frame <NUM>, the fixed scroll <NUM>, the orbiting scroll <NUM>, and the discharge cover <NUM> constitutes a compression part.

The motor part is coupled to an upper end of a rotating shaft <NUM> to be explained later, and the compression part is coupled to a lower end of the rotating shaft <NUM>. Accordingly, the compressor has the bottom-compression type structure described above, and the compression part is connected to the motor part by the rotating shaft <NUM> to be operated by a rotational force of the motor part.

Referring to <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 opened upper end of the cylindrical shell <NUM>. The lower shell <NUM> may be coupled to cover the opened lower end of the cylindrical shell <NUM>.

Accordingly, the inner space 110a of the casing <NUM> is sealed. The sealed inner space 110a of the casing <NUM> is divided into a lower space S1 and an upper space S2 based on the driving motor <NUM>.

The lower space S1 m is 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 space S12 with the compression unit therebetween.

The oil storage space S11 may be a space defined below the compression part to store oil or mixed oil in which liquid refrigerant is contained. The outflow space S12 is a space defined between an upper surface of the compression part and a lower surface of the driving motor <NUM>. Refrigerant compressed in the compression part or mixed refrigerant in which oil is contained is discharged into the outflow space S12.

The upper space S2 is 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. A refrigerant discharge pipe <NUM> communicates with the upper space S2.

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 passages Po1 and Po2 each spaced apart from an inner circumferential surface of the cylindrical shell <NUM> by a predetermined distance. This will be described again later together with an oil return passage.

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.

The refrigerant suction pipe <NUM> is formed in an L-like shape. One end of the refrigerant suction pipe <NUM> is inserted through the cylindrical shell <NUM> to directly communicate with a suction port <NUM> of the fixed scroll <NUM>, which configures the compression part. Accordingly, refrigerant can be introduced into a compression chamber V through the refrigerant suction pipe <NUM>.

Another end of the refrigerant suction pipe <NUM> is connected to an accumulator (not illustrated) which defines a suction passage outside the cylindrical shell <NUM>. The accumulator (not illustrated) is connected to an outlet side of the evaporator (not illustrated) through a refrigerant pipe. Accordingly, while refrigerant flows from the evaporator to the accumulator, liquid refrigerant is separated in the accumulator, and only gaseous refrigerant is directly introduced into the compression chamber V through the refrigerant suction pipe <NUM>.

A terminal bracket (not shown) may be coupled to an upper portion of the cylindrical shell <NUM> or the upper shell <NUM>, and a terminal (not shown) for transmitting external power to the driving motor <NUM> may be coupled through the terminal bracket.

An inner end 116a of the refrigerant discharge pipe <NUM> is 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>.

The refrigerant discharge pipe <NUM> corresponds to a passage through which compressed refrigerant discharged from the compression part to the inner space 110a of the casing <NUM> is exhausted toward a condenser (not illustrated). The refrigerant discharge pipe <NUM> may be disposed coaxially with the rotating shaft <NUM> to be described later. Accordingly, a venturi tube <NUM> disposed in parallel with the refrigerant discharge pipe <NUM> may be eccentrically disposed with respect to an axial center of the rotating shaft <NUM>.

The refrigerant discharge pipe <NUM> may be provided therein with an oil separator (not shown) for separating oil from refrigerant discharged from the compressor <NUM> to the condenser, or a check valve (not shown) for suppressing refrigerant discharged from the compressor <NUM> from flowing back into the compressor <NUM>.

One end portion of an oil circulation tube (not illustrated) may be coupled through a lower end portion of the lower shell <NUM>. Both ends of the oil circulation tube may be open, and another end portion of the oil circulation tube 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 tube.

The oil circulation valve may be open or closed according to an amount of oil stored in the oil storage space S11 or according to a set condition. For example, the oil circulation valve may be open to circulate oil stored in the oil storage space S11 to the compression part through the refrigerant suction pipe <NUM> at the beginning of the operation of the compressor, while being closed to prevent an excessive outflow of oil within the compressor during a normal operation.

Hereinafter, the driving motor <NUM> constituting the motor part will be described with reference to <FIG>. The driving motor <NUM> according to this implementation includes a stator <NUM> and a rotor <NUM>. The stator <NUM> is fixedly fitted onto 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 rotor accommodating portion 1211a is formed in a circular shape through a central portion of the stator core <NUM> such that the rotor <NUM> can be rotatably inserted therein. A plurality of stator-side return grooves 1211b may be recessed or cut out in a D-cut shape at an outer circumferential surface of the stator core <NUM> along the axial direction and disposed at preset distances along a circumferential direction.

A plurality of teeth (not illustrated) and slots (not illustrated) are alternately formed on an inner circumferential surface of the rotor accommodating portion 1211a in the circumferential direction, and the stator coil <NUM> is wound on each tooth by passing through the slots at both sides of the tooth.

More precisely, the slots may be spaces between neighboring stator coils in the circumferential direction. In addition, the slot defines an inner passage 120a, an air gap passage is defined between the inner circumferential surface of the stator core <NUM> and an outer circumferential surface of a rotor core <NUM> to be described later, and an oil return groove 1211b defines an external passage. The inner passages 120a and the air gap passage define a passage through which refrigerant discharged from the compression part moves to the upper space S2, and the external passage defines a first oil return passage Po1 through which oil separated in the upper space S2 is returned to the oil storage space S11.

The stator coil <NUM> is wound around the stator core <NUM> and electrically connected to an external power source through a terminal (not illustrated) that is coupled through the casing <NUM>. An insulator <NUM>, which is an insulating member, is inserted between the stator core <NUM> and the stator coil <NUM>.

The insulator <NUM> may be provided at an outer circumferential side and an inner circumferential side of the stator coil <NUM> to accommodate a bundle of the stator coil <NUM> in the radial direction, and may extend to both sides in the axial direction of the stator core <NUM>.

The rotor <NUM> includes 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> is rotatably inserted into the rotor accommodating portion 1211a of the stator core <NUM> with a predetermined gap 120a therebetween. The permanent magnets <NUM> are embedded in the rotor core <NUM> at preset distances 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 a main shaft portion <NUM> of the rotating shaft <NUM> to be described later. This implementation will be described based on an example in which the balance weight <NUM> is coupled to a lower end of the rotor core <NUM>.

In addition, the balance weight <NUM> is coupled to the lower end of the rotor core <NUM> and rotates in response to rotation of the rotor <NUM>.

A gas drain hole <NUM> for resolving differential pressure in a lower portion due to the discharge hole <NUM> may be formed in an inner circumference of the balance weight <NUM>, and a detailed structure thereof will be described later.

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.

An air gap or a winding gap through which discharge refrigerant can flow may be defined in the rotor <NUM>.

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> can smoothly rotate inside the main frame <NUM>.

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

Referring to <FIG>, the rotating shaft <NUM> according to the implementation includes a main shaft portion <NUM>, a first bearing portion <NUM>, a fixed bearing portion <NUM>, and an eccentric portion <NUM>.

The main shaft portion <NUM> is an upper portion of the rotating shaft <NUM> and formed in a cylindrical shape. The main shaft portion <NUM> may be partially press-fitted to the stator core <NUM>.

The first bearing portion <NUM> is a portion extending from a lower end of the main shaft portion <NUM>. The first bearing portion <NUM> may be inserted into a main bearing hole <NUM> of the main frame <NUM> so as to be supported in the radial direction.

The fixed bearing portion <NUM> indicates a lower portion of the rotating shaft <NUM>. The fixed bearing portion <NUM> may be inserted into a sub bearing hole 143a of a fixed scroll <NUM> so as to be supported in the radial direction. A central axis of the fixed bearing portion <NUM> and a central axis of the first bearing portion <NUM> may be aligned on the same line. That is, the first bearing portion <NUM> and the fixed bearing portion <NUM> may have the same central axis.

Meanwhile, a fixed bearing <NUM> coupled to the inner circumference of the fixed scroll <NUM> is press-fitted to an outer circumference of the fixed bearing portion <NUM>.

An eccentric portion <NUM> is formed between a lower end of the first bearing portion <NUM> and an upper end of the fixed bearing portion <NUM>. The eccentric portion <NUM> may be inserted into a rotating shaft coupling portion <NUM> of the orbiting scroll <NUM> to be described later.

The eccentric portion <NUM> may be eccentric with respect to the first bearing portion <NUM> and the fixed bearing portion <NUM> in the radial direction. That is, a central axis of the eccentric portion <NUM> may be eccentric with respect to the central axis of the first bearing portion <NUM> and the central axis of the fixed bearing portion <NUM>. Accordingly, when the rotating shaft <NUM> rotates, the orbiting scroll <NUM> can perform an orbiting motion with respect to the fixed scroll <NUM>.

On the other hand, an oil feeding passage <NUM> for feeding oil to the first bearing portion <NUM>, the fixed bearing portion <NUM>, and the eccentric portion <NUM> may be formed in a hollow shape inside the rotating shaft <NUM>. The oil feeding passage <NUM> may include an inner oil passage <NUM> defined in the rotating shaft <NUM> along the axial direction.

As the compression part is located below the motor part <NUM>, the inner oil passage <NUM> may be formed in a grooving manner from the lower end of the rotating shaft <NUM> approximately to a lower end or a middle height of the stator <NUM> or up to a position higher than an upper end of the first bearing portion <NUM>. Although not illustrated, the inner oil passage <NUM> may alternatively be formed through the rotating shaft <NUM> in the axial direction.

An oil pickup <NUM> for pumping up oil filled in the oil storage space S11 may be coupled to the lower end of the rotating shaft <NUM>, namely, a lower end of the fixing bearing portion <NUM>. The oil pickup <NUM> may include an oil feeding pipe <NUM> inserted into the inner oil passage <NUM> of the rotating shaft <NUM>, and a blocking member <NUM> accommodating the oil feeding pipe <NUM> to block an introduction of foreign materials. The oil feeding pipe <NUM> may extend downward through the discharge cover <NUM> to be immersed in the oil filled in the oil storage space S11.

The rotating shaft <NUM> may be provided with a plurality of oil feeding holes that communicate with the inner oil passage <NUM> to guide oil moving upward along the inner oil passage <NUM> to flow toward the first bearing portion <NUM>, the fixed bearing portion <NUM>, and the eccentric portion <NUM>.

Referring to <FIG>, an example in which the compression part according to the implementation includes the main frame <NUM>, the fixed scroll <NUM>, the orbiting scroll <NUM>, the discharge cover <NUM>, and the oil feeder <NUM> is illustrated.

The main frame <NUM> is fixedly disposed on an opposite side of the fixed scroll <NUM> with the orbiting scroll <NUM> interposed therebetween. In addition, the main frame <NUM> may accommodate the orbiting scroll <NUM> to perform an orbiting motion.

Referring to <FIG> and <FIG>, the main frame <NUM> may include a frame end plate <NUM>, a frame side wall <NUM>, and a main bearing accommodating portion <NUM>.

The frame end plate <NUM> is formed in an annular shape and disposed below the driving motor <NUM>. The frame side wall <NUM> may extend in a cylindrical shape from a rim of a lower surface of the main frame <NUM>. For example, the frame side wall <NUM> extends in a cylindrical shape from a rim of a lower surface of the frame end plate <NUM>. An outer circumferential surface of the frame side wall <NUM> is fixed to an inner circumferential surface of the cylindrical shell <NUM> in a shrink-fitting manner or welding manner. Accordingly, the oil storage space S11 and the outflow space S12 constituting the lower space S1 of the casing <NUM> can be separated from each other by the frame end plate <NUM> and the frame side wall <NUM>.

A second outflow hole <NUM> defining a part of an outflow passage may be formed through the frame side wall <NUM> in the axial direction. The second outflow hole <NUM> is formed to correspond to a first outflow hole <NUM> of the fixed scroll <NUM> to be described later, to define a refrigerant outflow passage (no reference numeral given) together with the first outflow hole <NUM>.

As illustrated in <FIG> and <FIG>, the second outflow hole <NUM> may be elongated in the circumferential direction, or may be provided in plurality disposed at preset distances along the circumferential direction. Accordingly, the second outflow hole <NUM> can secure a volume of a compression chamber relative to the same diameter of the main frame <NUM> by maintaining a minimum radial width with securing a discharge area. This may equally be applied to the first outflow hole <NUM> that is formed in the fixed scroll <NUM> to define a part of the outflow passage.

An outflow guide groove <NUM> to accommodate the plurality of second outflow holes 132a may be formed in an upper end of the second outflow hole <NUM>, namely, an upper surface of the frame end plate <NUM>. At least one outflow guide groove <NUM> may be formed according to positions of the second outflow holes <NUM>. For example, when the second outflow holes <NUM> form three groups, the number of outflow guide grooves <NUM> may be three to accommodate the three groups of second outflow holes <NUM>, respectively. The three outflow guide grooves <NUM> may be located on the same line in the circumferential direction.

The outflow guide groove <NUM> may be formed wider than the second outflow hole <NUM>. For example, the second outflow hole <NUM> may be formed on the same line in the circumferential direction together with a first oil return groove <NUM> to be described later. Therefore, when a flow path guide <NUM> to be described later is provided, the second outflow hole <NUM> having a small cross-sectional area may be difficult to be located at an inner side of the flow path guide <NUM>. With this reason, the outflow guide groove <NUM> may be formed at an end portion of the second outflow hole <NUM> while an inner circumferential side of the outflow guide groove <NUM> extends radially up to the inner side of the flow path guide <NUM>.

Accordingly, the second outflow hole <NUM> can be located adjacent to the outer circumferential surface of the main frame <NUM> by reducing an inner diameter of the second outflow hole <NUM>, and simultaneously can be prevented from being located at an outer side of the flow path guide <NUM>, namely, adjacent to the outer circumferential surface of the stator <NUM>.

A frame oil return groove (hereinafter, first oil return groove 1211b) <NUM> that defines a part of a second oil return passage Po2 may be formed axially through an outer circumferential surface of the frame end plate <NUM> and an outer circumferential surface of the frame side wall <NUM> that define the outer circumferential surface of the main frame <NUM>. The first oil return groove <NUM> may be provided by only one or may be provided in plurality disposed in the outer circumferential surface of the main frame <NUM> at preset distances in the circumferential direction. Accordingly, the outflow space S12 of the casing <NUM> can communicate with the oil storage space S11 of the casing <NUM> through the first oil return groove <NUM>.

The first oil return groove <NUM> is formed to correspond to a scroll oil return groove (hereinafter, second oil return groove 1211b) <NUM> of the fixed scroll <NUM>, which will be described later, and defines a second oil return passage together with the second oil return groove <NUM> of the fixed scroll <NUM>.

The main bearing accommodating portion <NUM> protrudes upward from an upper surface of a central portion of the frame end plate <NUM> toward the driving motor <NUM>. The main bearing accommodating portion <NUM> is provided with a main bearing hole <NUM> formed therethrough in a cylindrical shape along the axial direction. The first bearing portion <NUM> of the rotating shaft <NUM> is inserted into the main bearing hole <NUM> to be supported in the radial direction.

Hereinafter, the fixed scroll <NUM> will be described with reference to <FIG> and <FIG>. The fixed scroll <NUM> according to the implementation may include 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> may be formed in a disk shape having a plurality of concave portions on an outer circumferential surface thereof, and a sub bearing hole <NUM> defining the sub bearing portion <NUM> to be described later may be formed through a center of the fixed end plate <NUM> in the vertical direction. Discharge ports <NUM> and <NUM> may be formed around the sub bearing hole <NUM>. The discharge ports <NUM> and <NUM> may communicate with a discharge pressure chamber Vd so that compressed refrigerant is moved into the outflow space S12 of the discharge cover <NUM> to be explained later.

Although not illustrated, only one discharge port may be provided to communicate with both of a first compression chamber V1 and a second compression chamber V2 to be described later. In the implementation, however, a first discharge port (no reference numeral given) may communicate with the first compression chamber V1 and a second discharge port (no reference numeral given) may communicate with the second compression chamber V2. Accordingly, refrigerants compressed in the first compression chamber V1 and refrigerant compressed in the second compression chamber V2 can be independently discharged through the different discharge ports.

The fixed side wall <NUM> may extend in an annular shape from an edge of an upper surface of the fixed end plate <NUM> in the vertical direction. The fixed side wall <NUM> may be coupled to face the frame side wall <NUM> of the main frame <NUM> in the vertical direction.

A first outflow hole <NUM> may be formed through the fixed side wall <NUM> in the axial direction. The first outflow hole <NUM> may be elongated in the circumferential direction or may be provided in plurality disposed at preset distances along the circumferential direction. Accordingly, the first outflow hole <NUM> can secure a volume of a compression chamber relative to the same diameter of the fixed scroll <NUM> by maintaining a minimum radial width with securing a discharge area.

The first outflow hole <NUM> communicates with the second outflow hole <NUM> in a state in which the fixed scroll <NUM> is coupled to the cylindrical shell <NUM>. Accordingly, the first outflow hole <NUM> can define a refrigerant outflow passage together with the second outflow hole <NUM>.

A second oil return groove <NUM> may be formed in an outer circumferential surface of the fixed side wall <NUM>. The second oil return groove <NUM> communicates with the first oil return groove <NUM> provided at the main frame <NUM> to guide oil returned along the first oil return groove <NUM> to the oil storage space S11. Accordingly, the first oil return groove <NUM> and the second oil return groove <NUM> define the second oil return passage Po2 together with an oil return groove 1612b of the discharge cover <NUM> to be described later.

The fixed side wall <NUM> is provided with a suction port <NUM> formed through the fixed side wall <NUM> in the radial direction. An end portion of the refrigerant suction pipe <NUM> inserted through the cylindrical shell <NUM> is inserted into the suction port <NUM>. Accordingly, refrigerant can be introduced into a compression chamber V through the refrigerant suction pipe <NUM>.

The sub bearing portion <NUM> extends in the axial direction from a central portion of the fixed end plate <NUM> toward the discharge cover <NUM>. A sub bearing hole <NUM> having a cylindrical shape may be formed through a center of the sub bearing portion <NUM> in the axial direction, and the fixing bearing portion <NUM> of the rotating shaft <NUM> may be inserted into the sub bearing hole <NUM> to be supported in the radial direction. Therefore, the lower end (or the fixed bearing portion) of the rotating shaft <NUM> can be radially supported by being inserted into the sub bearing portion <NUM> of the fixed scroll <NUM>, and the eccentric portion <NUM> of the rotating shaft <NUM> can be supported in the axial direction by an upper surface of the fixed end plate <NUM> defining a periphery of the sub bearing portion <NUM>.

The 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> to be described later to define the compression chamber V. The fixed wrap <NUM> will be described later together with the orbiting wrap <NUM>.

Hereinafter, the orbiting scroll <NUM> will be described with reference to <FIG> and <FIG>. Specifically, the orbiting scroll <NUM> according to this implementation may include an orbiting end plate <NUM>, an orbiting wrap <NUM>, and a rotating shaft coupling portion <NUM>.

The orbiting end plate <NUM> is formed in a disk shape and accommodated in the main frame <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> may extend from a lower surface of the orbiting end plate <NUM> toward the fixed scroll <NUM>. The orbiting wrap <NUM> is engaged with the fixed wrap <NUM> to define the compression chamber V.

The orbiting wrap <NUM> may be formed in an involute shape together with the fixed wrap <NUM>. However, the orbiting wrap <NUM> and the fixed wrap <NUM> may be formed in various shapes other than the involute shape.

For example, the orbiting wrap <NUM> may be formed in a substantially elliptical shape in which a plurality of arcs having different diameters and origins are connected and the outermost curve may have a major axis and a minor axis. The fixed wrap <NUM> may also be formed in a similar manner.

An inner end portion of the orbiting wrap <NUM> may be formed at a central portion of the orbiting end plate <NUM>, and the rotating shaft coupling portion <NUM> may be formed through the central portion of the orbiting end plate <NUM> in the axial direction.

The eccentric portion <NUM> of the rotating shaft <NUM> is rotatably inserted 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 compression chamber V 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> may be disposed at a height at which the 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.

The rotating shaft coupling portion <NUM> may include a coupling side portion (not illustrated) that is in contact with an outer circumference of an orbiting bearing <NUM> to support the orbiting bearing <NUM>.

In addition, the rotating shaft coupling portion <NUM> may further include a coupling end portion (not illustrated) that is in contact with one end of the orbiting bearing <NUM> to support the orbiting bearing <NUM>.

Referring to <FIG> and <FIG>, the coupling side portion is formed on an inner circumference of the rotating shaft coupling portion <NUM> to come in contact with an outer circumference of the orbiting bearing <NUM>, and the coupling end portion is in contact with the upper end of the orbiting bearing <NUM> to support the orbiting bearing <NUM>.

On the other hand, the compression chamber V is formed in a space defined by the fixed end plate <NUM>, the fixed wrap <NUM>, the orbiting end plate <NUM>, and the orbiting wrap <NUM>. The compression chamber V may include a first compression chamber V1 defined between an inner surface of the fixed wrap <NUM> and an outer surface of the orbiting wrap <NUM>, and a second compression chamber V2 defined between an outer surface of the fixed wrap <NUM> and an inner surface of the orbiting wrap <NUM>.

Hereinafter, the discharge cover <NUM> will be described with reference to <FIG> and <FIG>.

As described above, the discharge cover <NUM> has the cover bottom surface <NUM>. Referring to <FIG>, etc., the example in which the cover bottom surface <NUM> is disposed to be spaced apart from a bottom surface of the fixed scroll <NUM> is illustrated.

In addition, the discharge cover <NUM> may further include a cover side portion <NUM> and a discharge space S3.

The cover side portion <NUM> may extend from the cover bottom surface <NUM> toward the fixed scroll <NUM>.

The discharge space S3 is formed together with the lower surface of the fixed scroll <NUM> inside the discharge cover <NUM> defined by the cover bottom surface <NUM> and the cover side portion <NUM>.

In this case, it may be understood that the cover bottom surface <NUM> and the cover side portion <NUM> connected thereto configures a cover housing portion <NUM> having the discharge space S3.

A through hole 1611a may be formed through a central portion of the cover bottom surface <NUM> in the axial direction, and the sub bearing portion <NUM> that protrudes downward from the fixed end plate <NUM> is inserted into the through hole 1611a.

The cover bottom surface <NUM> is spaced apart from the inner circumferential surface of the casing <NUM>. Specifically, the cover bottom surface <NUM> is spaced apart from the lower shell <NUM>. At this time, the oil storage space S11 is defined between the cover bottom surface <NUM> and the inner circumferential surface of the casing <NUM>.

The cover side portion <NUM> is formed in an annular shape by extending from the cover bottom surface <NUM> toward the fixed scroll <NUM> in the axial direction.

The cover side portion <NUM> extends outward from the outer circumferential surface of the cover housing portion <NUM> so as to be coupled to the lower surface of the fixed scroll <NUM> in a close contact manner.

In addition, at least one outflow hole accommodating groove <NUM> may be formed in an inner circumferential surface of the cover side portion <NUM> along the circumferential direction.

The outflow hole accommodating groove <NUM> indicates a portion of the cover side portion <NUM> that is recessed radially outward.

A space that is recessed radially outward due to the formation of the outflow hole accommodating groove <NUM> may overlap a scroll discharge hole 142a of the fixed scroll <NUM> in the vertical direction.

An inner surface of the cover side portion <NUM> excluding the outflow hole accommodating groove <NUM> is brought into close contact with the outer circumferential surface of the fixed scroll <NUM>, namely, the outer circumferential surface of the fixed end plate <NUM> so as to define a type of sealing part.

Side oil return grooves 1612b may be formed in an outer circumferential surface of the cover side portion <NUM> at a preset distance in the circumferential direction.

A cover flange portion <NUM> may extend in a radial direction from an outer circumferential surface of a portion of the cover side portion <NUM> excluding the portion having the outflow hole accommodating groove <NUM>. Specifically, the cover flange portion <NUM> extends from an outer circumferential surface of an upper side of the cover side portion <NUM>.

Coupling holes 162a for coupling the discharge cover <NUM> to the fixed scroll <NUM> with bolts may be formed through the cover flange portion <NUM>.

A plurality of flange oil return grooves 162b may be formed between the coupling holes 162a at preset distances along the circumferential direction.

The flange oil return grooves 162b may be recessed radially inward (toward a center) from an outer circumferential surface of the cover flange portion <NUM>.

Meanwhile, a discharge hole <NUM> and a refrigerant guide member <NUM> may be provided on a lower side of the discharge cover <NUM>, and a detailed description thereof will be described later.

The cover side portion <NUM> may be in close contact with the inner circumferential surface of the casing <NUM>, and may include an oil return groove 1612b formed in an outer circumference in a manner that partial portions are spaced apart from each other in the circumferential direction.

As described above, the cover bottom surface <NUM> includes the discharge hole <NUM> disposed inward by a predetermined distance from the center of the cover bottom surface <NUM> so as to communicate with the inner side of the oil feeder <NUM>.

The discharge hole <NUM> may have a diameter of <NUM> to <NUM>.

In addition, at least one discharge hole <NUM> may be provided.

The oil feeder <NUM> may include an oil suction pipe <NUM> and a blocking member <NUM>.

The oil suction pipe <NUM> may be coupled through the discharge cover <NUM>. For example, the oil suction pipe <NUM> may be coupled through the through hole 1611a of the discharge cover <NUM>.

<FIG> illustrates an example in which the oil suction pipe <NUM> is formed downward through the discharge cover <NUM>. Oil of high pressure inside the oil storage space S11 is suctioned through the oil suction pipe <NUM> to be supplied to each bearing <NUM>, <NUM>, and <NUM> and a compression chamber through the rotating shaft <NUM>. The example in which the oil suctioned upward inside the rotating shaft <NUM> is supplied to each of the bearings <NUM>, <NUM>, and <NUM> and the compression chamber V has been given in the description of <FIG>.

A lower portion of the oil suction pipe <NUM> may be immersed in the oil of the oil storage space S11.

The blocking member <NUM> accommodates the oil suction pipe <NUM> to block an introduction of foreign substances.

A side portion of the blocking member <NUM> may be formed in a mesh structure, for example, to filter out foreign substances.

In addition, the blocking member <NUM> may be provided with a pressure reducing pin <NUM>. The pressure reducing pin <NUM> reduces pressure of refrigerant that flows out through the discharge hole <NUM> of the discharge cover <NUM>, to minimize damage to the blocking member <NUM>.

As illustrated in <FIG> and <FIG>, the pressure reducing pin <NUM> may be disposed in a passage through which discharge refrigerant flows in the blocking member <NUM>. The pressure reducing pin <NUM> may have a diameter of <NUM> to <NUM>, for example.

Meanwhile, as described above, the diameter of the discharge hole <NUM> may be <NUM> to <NUM>. When the pressure reducing pin <NUM> is disposed, the diameter of the discharge hole <NUM> may be <NUM> or more.

On the other hand, as described above, the discharge cover <NUM> may further includes a cover flange portion <NUM> that extends radially from an upper end to an outer circumference of the cover side portion <NUM> to come into contact with the lower surface of the fixed scroll <NUM>.

At least one outflow hole accommodating groove <NUM> may be formed in an inner circumferential surface of the cover housing portion <NUM> in the circumferential direction.

The outflow hole accommodating groove <NUM> may be recessed outward in the radial direction, and the first outflow hole <NUM> of the fixed scroll <NUM> defining the outflow passage may be located inside the outflow hole accommodating groove <NUM>. Accordingly, an inner surface of the cover housing portion <NUM> excluding the outflow hole accommodating groove <NUM> may be brought into close contact with an outer circumferential surface of the fixed scroll <NUM>, namely, an outer circumferential surface of the fixed end plate <NUM> so as to configure a type of sealing part.

An entire circumferential angle of the outflow hole accommodating groove <NUM> may be formed to be smaller than or equal to an entire circumferential angle with respect to an inner circumferential surface of the discharge space S3 except for the outflow hole accommodating groove <NUM>. In this manner, the inner circumferential surface of the discharge space S3 except for the outflow hole accommodating groove <NUM> can secure not only a sufficient sealing area but also a circumferential length for forming the cover flange portion <NUM>.

The cover flange portion <NUM> may extend radially from a portion defining the sealing part, namely, an outer circumferential surface of a portion, excluding the outflow hole accommodating groove <NUM>, of an upper surface of the cover side portion <NUM>.

The cover flange portion <NUM> may be provided with coupling holes 162a for coupling the discharge cover <NUM> to the fixed scroll <NUM> with bolts, and a plurality of oil return grooves <NUM> radially recessed between adjacent coupling holes 162a at preset distances in the circumferential direction.

<FIG> is a sectional view illustrating a position at which the discharge hole <NUM> is formed in the discharge cover <NUM>.

In <FIG>, an example is shown in which the discharge hole <NUM> communicating with the inner side of the oil feeder <NUM> is formed in the cover bottom surface <NUM> disposed at the inner side of the inner circumference of the oil feeder <NUM>.

<FIG> illustrates an example in which a refrigerant guide member is further provided on the discharge cover <NUM> in the vicinity of the discharge hole <NUM>. The refrigerant guide member is provided in the discharge cover <NUM> to be spaced apart from the discharge hole <NUM>, to guide a flow of refrigerant discharged through the discharge hole <NUM>.

In one implementation, the refrigerant guide member <NUM> may be disposed on one side of the cover bottom surface <NUM> opposite to the fixed scroll <NUM>. In another implementation, the refrigerant guide member <NUM> may be disposed on an outer circumferential surface of the cover side portion <NUM>.

Further, the refrigerant guide member <NUM> may extend in a predetermined direction to guide the flow of the refrigerant in the predetermined direction.

<FIG> is a sectional view illustrating an example which does not fall within the scope of the claims, in which the discharge hole <NUM> is formed at another position in the discharge cover <NUM>. As illustrated in <FIG>, the discharge hole <NUM> may be provided in the discharge cover <NUM> at an outer side of an outer circumference of the oil feeder <NUM>.

Hereinafter, a flow path guide will be described.

Referring to <FIG>, a flow path guide <NUM> according to this implementation is installed between the motor part and the compression part, for example, in the outflow space S12. Specifically, the flow path guide <NUM> may be disposed at the upper end of the main frame <NUM> that faces the lower end of the driving motor <NUM>.

The flow path guide <NUM> divides the outflow space S12 into a refrigerant discharge flow path and an oil return flow path. Accordingly, refrigerant that has flowed out from the compression part to the outflow space S12 may move to the upper space S2 through the inner passages 120a and the air gap passage. Oil separated from the refrigerant in the upper space S2 may be returned to the oil storage space S11.

The flow path guide <NUM> may be formed in a single annular shape or may be formed in a shape defined by a plurality of arcuate parts. Hereinafter, an example in which the flow path guide <NUM> is formed in a single annular shape will be mainly described, but even when it is formed in a shape defined by a plurality of arcuate parts, the basic configuration for separating refrigerant and oil and operating effects thereof may be similar.

For example, the flow path guide <NUM> may include a bottom portion, an outer wall portion, and an inner wall portion.

The bottom portion is formed in an annular shape and fixed to the upper surface of the main frame <NUM>. An outflow passage cover portion may extend radially on an outer circumferential surface of the bottom portion, and may be provided with an outflow through hole that overlaps the outflow guide groove <NUM> of the main frame <NUM>.

The outer wall portion extends toward an insulator from a substantially outer circumferential surface of the bottom portion. The outer wall portion may be fitted to an inner side or outer side of the insulator <NUM> to overlap the insulator <NUM>. The outer wall portion may be formed in an annular shape extending in the circumferential direction or may be formed in an arcuate shape.

When the outer wall portion is formed in an annular shape, a diameter of the outer wall portion may be smaller or larger than a diameter of the insulator <NUM> or an upper end of the outer wall portion may be spaced apart from a lower end of the insulator <NUM>. Accordingly, a gap can be generated between the outer wall portion and the insulator <NUM>, and refrigerant (liquid refrigerant) flowing to the inside of the outer wall portion can move to an outer space S12b. This can allow the liquid refrigerant to quickly flow out of the compressor through a liquid refrigerant discharge unit.

Although not illustrated, when a communication path such as the gap is not formed between the annular outer wall portion and the insulator <NUM>, a communication groove (not illustrated) through which an inner space S12a and the outer space S12b communicate with each other may be formed through the bottom portion or the upper surface of the main frame <NUM> facing the bottom portion.

The inner wall portion extends toward the insulator <NUM> from a substantially inner circumferential surface of the bottom portion. The inner wall portion may extend in the axial direction or may extend by being bent to cover the balance weight <NUM>.

As described above, since discharge refrigerant is supplied to the oil storage space S11 through the discharge hole <NUM> formed through the cover bottom surface <NUM>, differential pressure may be generated in the lower portion of the oil storage space S11. In order to resolve this, a gas drain hole <NUM> may be formed in a side portion and an upper portion of the compression part.

The gas drain hole <NUM> is provided in the compression part to relieve an increase in pressure in the oil storage space S11 due to refrigerant moving to the oil storage space S11 through the discharge hole <NUM>. Accordingly, refrigerant can be discharged into the inner space of the casing <NUM> through the rotor core <NUM> so as to flow out of the compressor through the refrigerant discharge pipe <NUM>, thereby reducing pressure due to the refrigerant in the oil storage space S11.

For example, the gas drain hole <NUM> may include an upper communication portion <NUM> formed in the upper portion of the compression part, a lower communication portion <NUM> formed downward in a side portion of the compression part, and a middle communication portion <NUM> formed between the upper communication portion <NUM> and the lower communication portion <NUM> to communicate with each other.

The upper communication portion <NUM> may be formed in an inner circumference of the balance weight <NUM> such that refrigerant can flow to the upper portion of the compressor, and may be disposed between the inner circumference of the balance weight <NUM> and the main bearing accommodating portion <NUM> of the main frame <NUM> in a vertical direction.

The balance weight <NUM> is configured to rotate together with the rotor of the driving motor. As the balance weight <NUM> rotates, relatively low pressure is formed at the inner circumference of the balance weight <NUM>, compared to the oil storage space S11. Accordingly, refrigerant of high pressure within the oil storage space S11 can flow along the inner circumference of the balance weight with relatively low pressure through the gas drain hole <NUM>, so as to move out of the compressor through the refrigerant discharge pipe <NUM> inside the casing <NUM>.

In addition, the balance weight <NUM> extends in the circumferential direction by a predetermined angle. The balance weight <NUM> may have an approximately semicircular structure extending by <NUM> degrees to <NUM> degrees, and form a structure that is approximately half empty in the circumferential direction. With the structure of the balance weight <NUM>, refrigerant can flow upward through an empty space in which the balance weight <NUM> does not extend.

For example, the upper communication portion <NUM> may include a main communication hole 191a and an upper discharge space 191b.

The main communication hole 191a may be formed in the vertical direction in the frame end plate <NUM> disposed on the upper side of the main frame <NUM>.

The upper discharge space 191b is a space defined between the inner circumference of the balance weight <NUM> and the main bearing accommodating portion <NUM> of the main frame <NUM>.

Referring to <FIG>, <FIG>, and <FIG>, an example in which the upper communication portion <NUM> is formed at the inner circumference of the balance weight <NUM>, and refrigerant flows upward through the space where the balance weight <NUM> does not extend is illustrated.

The lower communication portion <NUM> may be formed in the vertical direction at an outer side of the compression part, more specifically, at an outer side of the fixed side wall of the fixed scroll <NUM> and the frame side wall of the main frame <NUM>.

The lower communication portion <NUM> communicates with the discharge space S3, which is a space defined in the discharge cover <NUM>, such that some of refrigerant gas in the discharge space S3 can flow to the upper communication portion <NUM> through the middle communication portion <NUM>.

For example, the lower communication portion <NUM> may include a first communication hole 193a and a second communication hole 193b.

The first communication hole 193a may communicate in the vertical direction in the fixed side wall <NUM> of the fixed scroll <NUM>, and in <FIG>, an upper portion of the first communication hole 193a may communicate with the second communication hole 193b and a lower portion thereof may communicate with the oil storage space S11.

The second communication hole 193b may communicate in the vertical direction in the frame side wall <NUM> of the main frame <NUM>, and in <FIG>, an upper portion of the second communication hole 193b may communicate with the middle communication portion <NUM> and a lower portion thereof may communicate with the first communication hole 193a.

In addition, the middle communication portion <NUM> may be formed laterally in the frame end plate <NUM> of the main frame <NUM> to communicate between the upper communication portion <NUM> and the lower communication portion <NUM>.

Referring to <FIG>, the lower communication portion <NUM> is formed in the vertical direction in the fixed side wall <NUM> of the fixed scroll <NUM> and the frame end plate <NUM> of the main frame <NUM> so as to communicate with the discharge space S3 in the discharge cover <NUM>, the middle communication portion <NUM> is formed in the frame end plate <NUM> of the main frame <NUM> such that the upper communication portion <NUM> and the lower communication portion <NUM> communicate with each other, and the upper communication portion <NUM> is formed in the vertical direction between the inner circumference of the balance weight <NUM> and the main bearing accommodating portion <NUM> of the main frame <NUM>.

With the structure of the gas drain hole <NUM>, differential pressure due to discharge refrigerant flowing into the storage space S11 can be eliminated, thereby improving circulation of the compressor, in particular, circulation of returned oil in the upper portion of the compressor.

The scroll compressor <NUM> according to the implementation 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> rotate 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>.

Accordingly, a volume of a compression chamber V decreases gradually along a suction pressure chamber Vs defined at an outer side of the compression chamber V, an intermediate pressure chamber Vm continuously formed toward a center, and a discharge pressure chamber Vd defined in a central portion.

Then, refrigerant moves to the accumulator (not illustrated) sequentially via a condenser (not illustrated), an expander (not illustrated), and an evaporator (not illustrated) of a refrigeration cycle. The refrigerant then flows toward the suction pressure chamber Vs forming the compression chamber V through the refrigerant suction pipe <NUM>.

The refrigerant suctioned into the suction pressure chamber Vs is compressed while moving to the discharge pressure chamber Vd via the intermediate pressure chamber Vm along a movement trajectory of the compression chamber V. The compressed refrigerant is discharged from the discharge pressure chamber Vd to the outflow space S12 of the discharge cover <NUM> through the discharge port <NUM>, <NUM>.

Then, the refrigerant (refrigerant is oil-mixed refrigerant but in description, mixed refrigerant or refrigerant will all be used) that has been discharged to the outflow space S12 of the discharge cover <NUM> moves to the outflow space S12 defined between the main frame <NUM> and the driving motor <NUM> through the outflow hole accommodating groove <NUM> of the discharge cover <NUM> and the first outflow hole <NUM> of the fixed scroll <NUM>. The mixed refrigerant passes through the driving motor <NUM> to move to the upper space S2 of the casing <NUM> defined above the driving motor <NUM>.

The mixed refrigerant moved to the upper space S2 is separated into refrigerant and oil in the upper space S2. The refrigerant (or some mixed refrigerant from which oil is not separated) flows out of the casing <NUM> through the refrigerant discharge pipe <NUM> so as to move to the condenser of the refrigeration cycle.

On the other hand, the oil separated from the refrigerant in the upper space S2 (or mixed oil with liquid refrigerant) moves to the lower space S1 along the first oil return passage Po1 between the inner circumferential surface of the casing <NUM> and the stator <NUM>. The oil moved to the lower space S1 is returned to the oil storage space S11 defined in the lower portion of the compression part along the second oil return passage Po2 between the inner circumferential surface of the casing <NUM> and the outer circumferential surface of the compression part.

This oil is thusly supplied to each bearing surface (not illustrated) through the oil feeding passage <NUM>, and partially supplied into the compression chamber V. The oil supplied to the bearing surfaces and the compression chamber V is discharged to the discharge cover <NUM> together with refrigerant and then returned. This series of processes is repeatedly performed.

At this time, as the flow path guide <NUM> by which the refrigerant outflow passage and the oil return passage are separated is disposed in a space, namely, the outflow space S12 defined between the lower end of the driving motor <NUM> and the upper end of the main frame <NUM>, the refrigerant that is discharged from the compression part and moves toward the upper space S2 can be suppressed from being mixed with the oil moving from the upper space S2 to the lower space S1.

In addition, the discharge hole <NUM> is formed through the cover bottom surface <NUM> of the discharge cover <NUM> at the inner side of the inner circumference of the oil feeder <NUM>. Accordingly, discharge refrigerant passed through the discharge hole <NUM> is spread at the inner side of the oil feeder <NUM>. This can allow adjustment of temperature of oil in the oil storage space S11 and reduce scattering of oil due to injected refrigerant.

In addition, as the discharge refrigerant flows into the oil storage space S11 through the discharge hole <NUM>, the pressure rises in the oil storage space S11 to generate differential pressure. The refrigerant in the storage space S11 in which pressure has risen passes through the lower communication portion <NUM>, the middle communication portion <NUM>, and the upper communication portion <NUM> of the gas drain hole <NUM>, flows upward through the air gap or winding gap formed in the rotor, and moves out of the compressor through the refrigerant discharge pipe <NUM>.

<FIG> is a graph showing experimental results in which temperature is increased by discharge refrigerant passing through the discharge hole <NUM>.

Referring to <FIG>, when oil is left in low temperature / the compressor is turned on, the oil (with low viscosity) in the low-temperature state can increase in temperature within a short time by using discharge refrigerant that passes through the discharge hole <NUM> without using a heat or a branch pipe. In particular, an example in which oil temperature has increased by <NUM> to <NUM> degrees compared to the related art is shown in <FIG>.

The scroll compressor of the present disclosure can adjust temperature of oil in the oil storage space without using a pipe.

First, a discharge hole that communicates with a discharge space and an oil storage space is formed through a discharge cover.

Accordingly, refrigerant collected in the discharge space is moved to the oil storage space through the discharge hole. The oil in the storage space can thus be brought into direct contact with and stirred with discharge refrigerant.

This may result in rapidly increasing temperature of the oil in the oil storage space at the beginning of an operation of the scroll compressor.

In addition, by virtue of the rapid increase in the temperature of the oil in the oil storage space, such oil can be prevented from being supplied in a low viscosity state.

This may result in preventing damage on bearings and lowering of an oil level due to oil with low viscosity.

In addition, as the oil inside the oil storage space is in direct contact with and stirred with the discharge refrigerant, a separate pipe branched from a refrigerant pipe may not be used and simultaneously the temperature of the oil in the oil storage space can be adjusted.

Accordingly, the scroll compressor can have a more simplified structure, and its manufacturing process can be further reduced.

In addition, production and maintenance costs of the scroll compressor can be reduced.

The number and size of discharge holes provided in the discharge cover can be adjusted according to a preset operation condition.

Accordingly, the scroll compressor can be operated at a discharge oil circulation ratio optimized for a preset operation condition.

The gas drain hole for resolving differential pressure in the lower portion of the compressor near the oil storage space can be formed, thereby improving circulation in the compressor, in particular, circulation of returned oil in the upper side of the compressor.

In particular, in the present disclosure, as the gas drain hole is formed in the inner circumference of the balance weight, refrigerant of high pressure in the oil storage space can flow along the inner circumference of the balance weight with relatively low pressure so as to be discharged to outside through the refrigerant discharge pipe disposed inside the casing, thereby relieving differential pressure in the lower portion of the compressor near the oil storage space.

The aforementioned scroll compressor <NUM> is not limited to the configuration and the method of the implementations described above, but the implementations may be configured such that all or some of the implementations are selectively combined so that various modifications can be made.

Claim 1:
A scroll compressor comprising:
a casing (<NUM>) having an oil storage space (S11);
a fixed scroll (<NUM>) disposed inside the casing (<NUM>);
an orbiting scroll (<NUM>) disposed on one side of the fixed scroll (<NUM>) and performing an orbiting motion relative to the fixed scroll (<NUM>) so as to form a compression chamber (V) together with the fixed scroll (<NUM>);
a main frame (<NUM>) fixedly connected to the one side of the fixed scroll (<NUM>) so that the orbiting scroll (<NUM>) is interposed between the main frame (<NUM>) and the fixed scroll (<NUM>);
a driving motor (<NUM>) configured to generate rotational force by receiving external power to move the orbiting scroll (<NUM>);
a discharge cover (<NUM>) coupled to another side of the fixed scroll (<NUM>) opposite to the one side of the fixed scroll (<NUM>) and having a cover bottom portion (<NUM>); and
an oil feeder (<NUM>) coupled to the cover bottom portion (<NUM>) and configured to communicate with the oil storage space (S11),
wherein the cover bottom portion (<NUM>) comprises a discharge hole (<NUM>) formed to face and communicate with the oil storage space (S11)
characterized in that the discharge hole (<NUM>) is disposed at a portion of the cover bottom portion (<NUM>), which is disposed at a radially inner side of the oil feeder (<NUM>), to communicate with an inner space of the oil feeder (<NUM>).