Patent Description:
A scroll compressor is a compressor forming a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber between both scrolls while the plurality of scrolls is an engaged state. Such a scroll compressor may obtain a relatively high compression ratio and stable torque by smooth connection of suction, compression, and discharge strokes of refrigerant, as compared with other types of compressors. Therefore, the scroll compressors are widely used for compressing refrigerant in air conditioners or the like.

Scroll compressors may be classified into a top-compression type and a bottom-compression type according to a position of a compression unit relative to a motor unit. The top-compression type is a compressor in which the compression unit is disposed above the motor unit, and the bottom-compression type is a compressor in which the compression unit is disposed below the motor unit.

In the top-compression type, since the compression unit is located far from a lower space of a casing, oil stored in the lower space of the casing is difficult to be moved to the compression unit. On the other hand, in the bottom-compression type, since the compression unit is located close to the lower space of the casing, the oil stored in the lower space of the casing can be easily moved to the compression unit. An implementation according to the present disclosure will illustrate a bottom-compression type scroll compressor. Therefore, hereinafter, a scroll compressor may be defined as a bottom-compression type scroll compressor unless otherwise specified.

The scroll compressor is provided with an oil supply portion for guiding oil stored in the lower space of the casing to the compression unit. The oil supply portion may supply oil using an oil pump or using differential pressure. An oil supplying method using the differential pressure can eliminate a component such as an oil pump, thereby reducing a fabricating cost and effectively supplying oil to the compression unit.

Prior Art <NUM> (<CIT>) discloses an oil supply structure of a scroll compressor using differential pressure. The oil supply structure disclosed in Prior Art <NUM> includes oil supply holes formed through a fixed scroll to guide oil, which has been guided to an intermediate pressure chamber, to a compression chamber. The oil supply holes are formed to communicate with a first compression chamber formed between an inner surface of a fixed wrap and an outer surface of an orbiting wrap, and a second compression chamber formed between an outer surface of the fixed wrap and an inner surface of the orbiting wrap, respectively.

The oil supply hole communicating with the first compression chamber may be defined as a first oil supply hole and the oil supply hole communicating with the second compression chamber may be defined as a second oil supply hole. Prior Art <NUM> limits that the first oil supply hole and the second oil supply hole are respectively formed at positions where they are open before a suction completion time point of each compression chamber. As the oil supply holes individually communicate with the first compression chamber and the second compression chamber, smooth oil supply to both compression chambers can be expected even during a low-pressure ratio operation.

However, as in Prior Art <NUM>, if the first oil supply hole communicating with the first compression chamber and the second oil supply hole communicating with the second compression chamber are provided, a section in which the first oil supply hole and the second oil supply hole communicate with each other may be generated during an operation of the compressor. In the section where the first oil supply hole and the second oil supply hole communicate with each other, a part of refrigerant which is compressed in a compression chamber where pressure is high may flow back into a compression chamber where pressure is low due to such pressure difference between the first compression chamber and the second compression chamber. As a result, compression loss may occur due to leakage between the compression chambers. This may often occur in an operation of a low-pressure ratio which is less than <NUM>.

<CIT> discloses a scroll compressor comprising a first compression chamber oil supply hole and a second compression chamber oil supply hole formed through the orbiting end plate to communicate with the first compression chamber and the second compression chamber, respectively. To reduce a friction loss in the compression chamber oil is supplied from the back pressure chamber alternately to the outer compression chamber and the inner compression chamber. The two holes are never open to both of their respective compression chambers at the same time.

One aspect of the present disclosure is to provide a scroll compressor, capable of suppressing compression loss in a first compression chamber formed between an inner surface of a fixed wrap and an outer surface of an orbiting wrap, and a second compression chamber formed between an outer surface of the fixed wrap and an inner surface of the orbiting wrap.

Another aspect of the present disclosure is to provide a scroll compressor, capable of suppressing refrigerant compressed in a high-pressure compression chamber from flowing back toward a low-pressure compression chamber through an oil supply passage while oil supply passages individually communicate with a first compression chamber and a second compression chamber.

Still another aspect of the present disclosure is to provide a scroll compressor, capable of preventing an oil supply passage communicating with a first compression chamber and an oil supply passage communicating with a second compression chamber from being simultaneously open to the respective compression chambers based on a crank angle, or minimizing a simultaneous open time.

Still another aspect of the present disclosure is to provide a scroll compressor, capable of preventing a first compression chamber and a second compression chamber from communicating with each other through an oil supply passage while oil is smoothly supplied to the first compression chamber and the second compression chamber during a low-pressure ratio operation.

In order to achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a scroll compressor, in which a first crank angle range is out of a second crank angle range under assumption that a crank angle range in which a first compression chamber oil supply hole is opened with respect to a first compression chamber is the first crank angle range and a crank angle range in which a second compression chamber oil supply hole is opened with respect to a second compression chamber is the second crank angle range. Accordingly, the first crank angle range and the second crank angle range do not overlap each other, which may prevent the first compression chamber and the second compression chamber from communicating with each other, thereby suppressing leakage between the compression chambers.

Here, an interval between the first crank angle range and the second crank angle range may be formed to be smaller than or equal to <NUM>° based on a crank angle. This may result in minimizing a section in which oil is not supplied and thus reducing friction loss as much as possible.

In addition, in order to achieve those aspects and other advantages of the present disclosure, there is provided a scroll compressor, including a casing, a driving motor provided in an inner space of the casing, a rotating shaft driven by the driving motor, a fixed scroll disposed at one side of the driving motor and provided with a fixed end plate and a fixed wrap formed on one side surface of the fixed end plate, an orbiting scroll coupled to the rotating shaft and provided with an orbiting end plate facing the fixed end plate, and an orbiting wrap formed on one side surface of the orbiting end plate and engaged with the fixed wrap to form a first compression chamber and a second compression chamber, and first and second compression chamber oil supply holes formed through the orbiting end plate to communicate with the first compression chamber and the second compression chamber, respectively. Accordingly, oil can be supplied to the first compression chamber and the second compression chamber almost without interruption, thereby increasing reliability of the compressor.

For example, a crank angle range of the rotating shaft in which the first crank angle range and the second crank angle range do not overlap each other may be longer than a crank angle range of the rotating shaft in which the first crank angle range and the second crank angle range overlap each other. This may result in minimizing the communication between the first compression chamber and the second compression chamber through the first compression chamber oil supply hole and the second compression chamber oil supply hole.

Specifically, an outlet of the first compression chamber oil supply hole communicating with the first compression chamber and an outlet of the second compression chamber oil supply hole communicating with the second compression chamber may be arranged such that the first crank angle range and the second crank angle range do not overlap each other. This may result in suppressing leakage between the first compression chamber and the second compression chamber through the first compression chamber oil supply hole and the second compression chamber oil supply hole.

Here, the first compression chamber may be formed between an inner circumferential surface of the fixed wrap and an outer circumferential surface of the orbiting wrap, and the second compression chamber may be formed between an outer circumferential surface of the fixed wrap and an inner circumferential surface of the orbiting wrap. An outlet of the first compression chamber oil supply hole may be formed at a position spaced apart by a first interval from an outer circumferential surface of an outermost orbiting wrap, and an outlet of the second compression chamber oil supply hole may be formed at a position spaced apart by a second interval from an inner circumferential surface of the outermost orbiting wrap. With the configuration, even during an operation of a low pressure ratio of less than <NUM>, in an crank angle range for the first compression chamber and an crank angle range for the second compression chamber, a first crank angle range in which the first compression chamber oil supply hole is opened toward the first compression chamber may not overlap a second crank angle range in which the second compression chamber oil supply hole is opened toward the second compression chamber, thereby enhancing compression efficiency.

Here, the first interval may be greater than or equal to the second interval. Accordingly, the outlet of the first compression chamber oil supply hole and the outlet of the second compression chamber oil supply hole can be formed at positions where the first crank angle range and the second crank angle range do not overlap each other.

In addition, the first interval may be equal to or greater than a value obtained by subtracting an inner diameter of the outlet of the first compression chamber oil supply hole from a wrap thickness of the orbiting wrap adjacent to the outlet of the first compression chamber oil supply hole. The second interval may be formed at a position equal to or greater than a value obtained by subtracting an inner diameter of the outlet of the second compression chamber oil supply hole from a wrap thickness of the orbiting wrap adjacent to the outlet of the second compression chamber oil supply hole. This may result in optimizing positions of the first compression chamber oil supply hole and the second compression chamber oil supply hole so that the first crank angle range and the second crank angle range do not overlap each other.

Here, the outlet of the first compression chamber oil supply hole may be formed at a position spaced apart from the outer circumferential surface of the outermost orbiting wrap by an inner diameter of the outlet of the first compression chamber oil supply hole or farther, and the outlet of the second compression chamber oil supply hole may be formed at a position spaced apart from the inner circumferential surface of the outermost orbiting wrap by an inner diameter of the outlet of the second compression chamber oil supply hole or farther.

The second crank angle range may start continuously from an end of the first crank angle range, and the first crank angle range may start at a preset interval from an end of the second crank angle range.

An interval between the start of the first crank angle range and the end of the second crank angle range may be greater than <NUM>° and smaller than or equal to <NUM>° based on a crank angle of the rotating shaft. Accordingly, a non-oil supply crank angle range can be minimized even without an overlap between the first crank angle range and the second crank angle range, thereby reducing friction loss of the compressor.

The outlet of the first compression chamber oil supply hole may be formed at a position where the first compression chamber oil supply hole communicates with the first compression chamber after a time point when a suction in the first compression chamber is completed, and the outlet of the second compression chamber oil supply hole may be formed at a position where the second compression chamber oil supply hole communicates with the second compression chamber after a time point when a suction in the second compression chamber is competed. This may result in suppressing an increase in a specific volume of refrigerant sucked by pressure of oil to be supplied, thereby reducing suction loss of the compressor.

When a crank angle of the rotating shaft at which an outer circumferential surface of a suction end of the orbiting wrap is in contact with an inner circumferential surface of the fixed wrap is <NUM>°, the outlet of the first compression chamber oil supply hole may be formed to overlap with pockets forming the first compression chamber respectively at crank angles of <NUM>°, <NUM>°, and <NUM>°. The outlet of the second compression chamber oil supply hole may be formed to overlap with pockets forming the second compression chamber respectively at crank angles of <NUM>°, <NUM>°, and <NUM>°. Accordingly, the first compression chamber oil supply hole and the second compression chamber oil supply hole can communicate with the compression chambers, respectively, at arbitrary crank angles.

An outlet of the second compression chamber oil supply hole may be blocked with respect to the second compression chamber in the first crank angle range, and an outlet of the first compression chamber oil supply hole may be blocked with respect to the first compression chamber in the second crank angle range. This may prevent the first compression chamber and the second compression chamber from communicating with each other through the compression chamber oil supply holes.

The outlet of the first compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° and the outlet of the second compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° in a first pressure ratio range. The outlet of the first compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° and the outlet of the second compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° in a second pressure ratio range greater than the first pressure ratio range. The outlet of the first compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° and the outlet of the second compression chamber oil supply hole may be formed in a crank angle range of <NUM>° to <NUM>° in a third pressure ratio range greater than the second pressure ratio range. Accordingly, within an arbitrary pressure ratio range, the first compression chamber oil supply hole and the second compression chamber oil supply hole can be formed at positions where the oil supply holes communicate with the compression chambers, respectively, so as to prevent leakage between the compression chambers and minimize interruption of oil supply to each compression chamber.

Here, the first compression chamber oil supply hole and the second compression chamber oil supply hole may be formed through the orbiting end plate.

In this case, the orbiting scroll may be provided with an oil accommodating portion communicating with the inner space of the casing, and the first compression chamber oil supply hole and the second compression chamber oil supply hole may communicate with the oil accommodating portion.

The orbiting scroll may be provided with a rotating shaft coupling portion formed therethrough in an axial direction such that a rotating shaft is inserted. An eccentric portion bearing may be fitted onto an inner circumferential surface of the rotating shaft coupling portion. The eccentric portion bearing may be formed to be shorter than the rotating shaft coupling portion in length, such that the oil accommodating portion can be formed in an annular shape between an end of the eccentric portion bearing and the inner circumferential surface of the rotating shaft coupling portion.

A first pressure reducing member may be provided in the first compression chamber oil supply hole, and a second pressure reducing member may be provided in the second compression chamber oil supply hole. An outer diameter of the first pressure reducing member may be smaller than an inner diameter of the first compression chamber oil supply hole, and an outer diameter of the second pressure reducing member may be smaller than an inner diameter of the second compression chamber oil supply hole.

Description will now be given in detail of a scroll compressor according to exemplary embodiments disclosed herein, with reference to the accompanying drawings. Hereinafter, a description will be given by defining an axial direction and a radial direction based on a rotating shaft. That is, for the sake of explanation, a lengthwise direction of a rotating shaft is defined as the axial direction (or gravity direction) of the compressor, and a transverse direction of the rotating shaft is defined as a radius of the compressor.

In addition, a description will be given of a high-pressure type scroll compressor, which is a vertical type scroll compressor with a motor unit and a compression unit arranged in a vertical direction and is also a bottom-compression type scroll compressor with the compression unit located below the motor unit, and in which a refrigerant suction pipe is directly connected to the compression unit and a refrigerant discharge pipe communicates with an inner space of a casing.

<FIG> is a diagram illustrating a refrigeration cycle apparatus to which a bottom-compression type scroll compressor in accordance with one implementation of the present disclosure is applied.

Referring to <FIG>, a refrigeration cycle apparatus to which the scroll compressor according to the implementation is applied may be configured such that a compressor <NUM>, a condenser <NUM>, an expansion apparatus <NUM>, and an evaporator <NUM> define a closed loop. The condenser <NUM>, the expansion apparatus <NUM>, and the evaporator <NUM> may be sequentially connected to a discharge side of the compressor <NUM> and a discharge side of the evaporator <NUM> may be connected to a suction side of the compressor <NUM>.

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

<FIG> is a longitudinal view illustrating a bottom-compression type scroll compressor in accordance with an implementation of the present disclosure, <FIG> is an enlarged longitudinal view illustrating a compression unit in in <FIG>, and <FIG> is a sectional view taken along the line "IV-IV" of <FIG>.

Referring to these drawings, the scroll compressor according to the implementation of the present disclosure is of a high-pressure type and a bottom-compression type. Hereinafter, it will be abbreviated as a scroll compressor and described.

A scroll compressor according to an implementation may include a driving motor <NUM> disposed in an upper portion of a casing <NUM>, and a main frame <NUM>, an orbiting scroll <NUM>, a fixed scroll <NUM>, and a discharge cover <NUM> sequentially disposed below the driving motor <NUM>. In general, the driving motor <NUM> may constitute a motor unit, and the main frame <NUM>, the orbiting scroll <NUM>, the fixed scroll <NUM>, and the discharge cover <NUM> may constitute a compression unit.

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

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> 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>. An oil storage space S3 may be separately defined below the lower space S1 based on the compression unit. The lower space S1 may define a discharge space, and the upper space S2 may define an oil separation space.

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 spaced apart from an inner circumferential surface of the cylindrical shell <NUM> by a preset interval, thereby defining an oil recovery passage (no reference numeral given). This will be described again later together with the oil recovery passage.

A refrigerant suction pipe <NUM> may be coupled through a side surface of the cylindrical shell <NUM>. The refrigerant suction pipe <NUM> may be coupled through the cylindrical shell <NUM> forming the casing <NUM> in a radial direction.

The refrigerant suction pipe <NUM> may be formed in an L-like shape. One end of the refrigerant suction pipe <NUM> may be coupled through the cylindrical shell <NUM> so as to communicate directly with a first suction passage <NUM> of the discharge cover <NUM> to be explained later, which defines a compression unit. In other words, the refrigerant suction pipe <NUM> may be connected to a suction passage <NUM> to be described later at a position lower than a compression chamber V in an axial direction. Accordingly, in this implementation, as the suction passage <NUM> is formed in the oil storage space S3 which is an empty space below the compression unit, a suction passage opening and closing valve <NUM> to be described later may be disposed to operate in the axial direction in a bottom-compression manner, without extending a length of the compressor.

Another end of the refrigerant suction pipe <NUM> may be connected to an accumulator <NUM> outside the cylindrical shell <NUM>. The accumulator <NUM> may be 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 may be separated in the accumulator <NUM>, and only gaseous refrigerant may be 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.

A 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>. The refrigerant discharge pipe <NUM> may correspond to a passage through which compressed refrigerant discharged from the compression unit to the inner space 110a of the casing <NUM> is externally discharged toward the condenser <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 <NUM>, or a check valve (not shown) for suppressing refrigerant discharged from the compressor <NUM> from flowing back into the compressor <NUM>.

Hereinafter, a driving motor constituting the motor unit will be described.

Referring to <FIG>, the driving motor <NUM> according to the implementation may include a stator <NUM> and a rotor <NUM>. The stator <NUM> may be fixed onto the inner circumferential surface of the cylindrical shell <NUM>, and the rotor <NUM> may be rotatably disposed in the stator <NUM>.

The stator <NUM> may include a stator core <NUM> and a stator coil <NUM>.

The stator core <NUM> may be formed in a cylindrical shape and may be shrink-fitted onto the inner circumferential surface of the cylindrical shell <NUM>. A plurality of recessed surfaces may be formed in a D-cut shape recessed into an outer circumferential surface of the stator core <NUM> along the axial direction, and disposed at preset intervals along a circumferential direction.

The recessed surfaces 1211a may be spaced apart from the inner circumferential surface of the cylindrical shell <NUM> to define a first oil recovery passage (not shown) through which oil passes. Accordingly, oil separated from refrigerant in the upper space S2 may move to the lower space S1 through the first oil recovery passage, and then return into the oil storage space S3 through a second oil recovery passage (no reference numeral given).

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

The insulator <NUM> may extend long to both sides in the axial direction to accommodate a bundle of the stator coil <NUM> in the radial direction, and a portion of the insulator <NUM> which extends downwardly may configure an oil separation portion (no reference numeral given) to prevent refrigerant discharged into the lower space S1 from being mixed with oil recovered from the upper space S2.

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

The rotor core <NUM> may be formed in a cylindrical shape, and may be rotatably inserted into the stator core <NUM> with a preset gap therebetween. The permanent magnets <NUM> may be embedded in the rotor core <NUM> at preset intervals along a circumferential direction.

In addition, 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 shaft portion <NUM> of a rotating shaft <NUM> to be described later.

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

The main frame <NUM> may be provided with a main bearing <NUM> configured as a bush bearing to support the lower end portion of the rotating shaft <NUM>. Accordingly, the rotating shaft <NUM> may transfer the rotational force of the motor unit <NUM> to the orbiting scroll <NUM> of the compression unit <NUM>. 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> may include a shaft portion <NUM>, a first bearing portion <NUM>, a second bearing portion <NUM>, and an eccentric portion <NUM>.

The shaft portion <NUM> may be a portion constituting the upper half of the rotating shaft <NUM>. The shaft portion <NUM> may be formed in a solid cylindrical shape, and the rotor <NUM> may be press-fitted into an upper portion of the shaft portion <NUM>.

The first bearing portion <NUM> may be a portion extending from a lower end of the shaft portion <NUM>. The first bearing portion <NUM> may be inserted into a main bearing hole 133a of the main frame <NUM> to be described later so as to be supported in the radial direction.

The second bearing portion <NUM> may be a portion corresponding to a lower end of the shaft portion <NUM>. The second bearing portion <NUM> may be inserted into a sub bearing hole 143a of the fixed scroll <NUM> to be described later so as to be supported in the radial direction. The second bearing portion <NUM> may be coaxially disposed with respect to the first bearing portion <NUM> so as to have the same axial center.

The eccentric portion <NUM> may be formed between a lower end of the first bearing portion <NUM> and an upper end of the second 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> or the second bearing portion <NUM> in the radial direction. Accordingly, when the rotating shaft <NUM> rotates, the orbiting scroll <NUM> may perform an orbiting motion with respect to the fixed scroll <NUM>.

Meanwhile, the rotating shaft <NUM> may include an oil supply passage <NUM> formed therein to supply oil to the first bearing portion <NUM>, the second bearing portion <NUM>, and the eccentric portion <NUM>. The oil supply passage <NUM> may include an inner oil passage <NUM> formed in the rotating shaft along the axial direction.

As the compression unit is located below the motor unit <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>. Of course, according to circumstances, the inner oil passage <NUM> may also be formed through the rotating shaft <NUM> in the axial direction.

In addition, an oil feeder <NUM> for pumping up oil filled in the oil storage space S3 may be coupled to the lower end of the rotating shaft <NUM>, namely, a lower end of the second bearing portion <NUM>. The oil feeder <NUM> may include an oil suction pipe <NUM> inserted into the inner oil passage <NUM> of the rotating shaft <NUM>, and a blocking member <NUM> accommodating the oil supply pipe <NUM> to block an introduction of foreign materials. The oil suction pipe <NUM> may extend downward through the discharge cover <NUM> to be immersed in the oil filled in the oil storage space S3.

The rotating shaft <NUM> may be provided with a plurality of oil holes communicating with the inner oil passage <NUM> to guide oil moving upward along the inner oil passage <NUM> toward the first and second bearing portions <NUM> and <NUM> and the eccentric portion <NUM>.

The plurality of oil holes may penetrate from an inner circumferential surface of the inner oil passage <NUM> to outer circumferential surfaces of the bearing portions <NUM> and <NUM> and the eccentric portion <NUM>. The plurality of oil holes may constitute the oil supply passage <NUM> together with the inner oil passage <NUM>, and include a first oil hole 1262a, a second oil hole 1262b, and a third oil hole 1262c.

The first oil hole 1262a may be formed from the inner circumferential surface of the inner oil passage <NUM> to the outer circumferential surface of the first bearing portion <NUM> in a penetrating manner, and the second oil hole 1262b may be formed from the inner circumferential surface of the inner oil passage <NUM> to the outer circumferential surface of the second bearing portion <NUM> in a penetrating manner, and the third oil hole 1262c may be formed from the inner circumferential surface of the inner oil passage <NUM> to the outer circumferential surface of the eccentric portion <NUM> in a penetrating manner. In other words, the second oil hole 1262b, the third oil hole 1262c, and the first oil hole 1262a may be sequentially formed from the lower end to the upper end of the rotating shaft <NUM>.

In addition, a first oil groove 1263a may be formed on the outer circumferential surface of the first bearing portion <NUM>. The first oil groove 1263a may communicate with the inner oil passage <NUM> through the first oil hole 1262a. A second oil groove 1263b may be formed on the second bearing portion <NUM> of the rotating shaft <NUM>. The second oil groove 1263b may communicate with the inner oil passage <NUM> through the second oil hole 1262b.

In addition, a third oil groove 1263c may be formed on the outer circumferential surface of the eccentric portion <NUM>. The third oil groove 1263c may communicate with the inner oil passage <NUM> through the third oil hole 1262c. Accordingly, oil which moves from the inner oil passage <NUM> to each of the oil grooves 1263a, 1263b, and 1263c through each of the oil holes 1262a, 1262b, and 1262c may be evenly spread on the outer circumferential surface of each of the bearing portions <NUM> and <NUM> and the outer circumferential surface of the eccentric portion <NUM>, thereby lubricating each bearing surface.

Here, the oil moving to the first oil groove 1263a of the first bearing portion <NUM> or the oil moving to the third oil groove 1263c of the eccentric portion <NUM> may flow to an oil accommodating portion <NUM> to be described later. And, this oil may be supplied to the compression chamber through a compression chamber oil supply hole <NUM> provided in the orbiting scroll <NUM> to be described later. The compression chamber oil supply hole will be described again later together with the orbiting scroll.

Hereinafter, the compression unit will be described. <FIG> is a perspective view of a compression unit in an assembled state in accordance with an implementation, <FIG> is an exploded perspective view of the compression unit according to <FIG>, viewed from the top, and <FIG> is an exploded perspective view of the compression unit according to <FIG>, viewed from the bottom.

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

The frame end plate <NUM> may be formed in an annular shape and installed below the driving motor <NUM>. Accordingly, the lower space S1 of the casing <NUM> may be separated from the oil storage space S3 by the frame end plate <NUM>.

The frame side wall portion <NUM> may extend in a cylindrical shape from an edge of a lower surface of the frame end plate <NUM>, and an outer circumferential surface of the frame side wall portion <NUM> may be fixed to the inner circumferential surface of the cylindrical shell <NUM> in a shrink-fitting or welding manner.

A scroll accommodating portion <NUM> to be explained later may formed inside the frame side wall portion <NUM>. The orbiting scroll <NUM> to be described later may be accommodated in the scroll accommodating portion <NUM> so as to perform an orbiting motion. To this end, an inner diameter of the frame side wall portion <NUM> may be greater than an outer diameter of an orbiting end plate <NUM> to be described later.

A plurality of frame discharge holes 132a may be formed at the frame side wall portion <NUM>. The plurality of frame discharge holes 132a may be formed through the frame side wall portion <NUM> in the axial direction and disposed at preset intervals along a circumferential direction.

The frame discharge holes (hereinafter, referred to as second discharge holes) 132a may be formed to correspond to scroll discharge holes 142a of the fixed scroll <NUM> to be described later, and define a first refrigerant discharge passage (no reference numeral given) together with the scroll discharge holes 142a.

Also, a plurality of frame oil recovery grooves (hereinafter, referred to as first oil recovery grooves) 132b may be formed on an outer circumferential surface of the frame side wall portion <NUM> with the second discharge holes 132a interposed therebetween. The plurality of first oil recovery grooves 132b may be formed in the axial direction at preset intervals along the circumferential direction.

The first oil recovery grooves 132b may be formed to correspond to scroll oil recovery groove 142b of the fixed scroll <NUM>, which will be described later, and define a second oil recovery passage together with the scroll oil recovery grooves 142b of the fixed scroll <NUM>.

The main bearing portion <NUM> may protrude upward from an upper surface of a central portion of the frame end plate <NUM> toward the driving motor <NUM>. The main bearing portion <NUM> may be provided with a main bearing hole 133a formed therethrough in a cylindrical shape along the axial direction. A main bearing <NUM> configured as a bush bearing may be firmly fitted onto an inner circumferential surface of the main bearing hole 133a. The main bearing portion <NUM> of the rotating shaft <NUM> may be fitted onto the main bearing <NUM> to be supported in the radial direction.

The scroll accommodating portion <NUM> may be a space defined by a lower surface of the frame end plate <NUM> and the inner circumferential surface of the frame side wall portion <NUM>. An orbiting end plate <NUM> of the orbiting scroll <NUM> to be described later may be supported in the axial direction by the lower surface of the frame end plate <NUM>, and accommodated in the frame side wall portion <NUM> in a manner that its outer circumferential surface is spaced apart from the inner circumferential surface of the frame side wall portion <NUM> by a preset interval (for example, an orbiting radius). Accordingly, the inner diameter of the frame side wall portion <NUM> constituting the scroll accommodating portion <NUM> may be greater than the outer diameter of the orbiting end plate <NUM> by the orbiting radius or more.

In addition, the frame side wall portion <NUM> defining the scroll accommodating portion <NUM> may have a height (depth) that is greater than or equal to a thickness of the orbiting end plate <NUM>. Accordingly, while the frame side wall portion <NUM> is supported on the upper surface of the fixed scroll <NUM>, the orbiting scroll <NUM> may perform an orbiting motion in the scroll accommodating portion <NUM>.

The scroll support portion <NUM> may be formed in an annular shape on the lower surface of the frame end plate <NUM> that faces the orbiting end plate <NUM> of the orbiting scroll <NUM> to be described later. Accordingly, an Oldham ring <NUM> may be pivotably inserted between an outer circumferential surface of the scroll support portion <NUM> and the inner circumferential surface of the frame side wall portion <NUM>.

In addition, the scroll support portion <NUM> may have a lower surface formed flat, so that a back pressure sealing member <NUM> provided on the orbiting end plate <NUM> of the orbiting scroll <NUM> to be described later is in contact with the lower surface in a sliding manner.

The back pressure sealing member <NUM> may be formed in an annular shape, thereby defining an oil accommodating portion <NUM> between the scroll support portion <NUM> and the orbiting end plate <NUM>. Accordingly, oil flowing into the oil accommodating portion <NUM> through the third oil hole 1262c of the rotating shaft <NUM> may be introduced into the compression chamber V through a compression chamber oil supply hole <NUM> of the orbiting scroll <NUM> to be described later.

Hereinafter, the fixed scroll will be described.

Referring to <FIG> again, the fixed scroll <NUM> according to the implementation may include a fixed end plate <NUM>, a fixed side wall portion <NUM>, a sub bearing portion <NUM>, and a fixed wrap <NUM>.

The fixed end plate <NUM> may be formed approximately in a disk shape, and a sub bearing hole 143a forming the sub bearing portion <NUM> to be described later may be formed through a center of the fixed end plate <NUM> in the axial direction. Discharge ports 141a and 141b may be formed around the sub bearing hole 143a. The discharge ports 141a and 141b may communicate with a discharge chamber Vd so that compressed refrigerant is moved into a discharge space S4 of the discharge cover <NUM> to be explained later.

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 illustrated implementation, however, the first discharge port 141a may communicate with the first compression chamber V1 and the second discharge port 141b may communicate with the second compression chamber V2. Accordingly, refrigerant compressed in the first compression chamber V1 and refrigerant compressed in the second compression chamber V2 may be independently discharged through the different discharge ports.

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

A plurality of scroll discharge holes (hereinafter, referred to as first discharge holes) 142a may be formed through the fixed side wall portion <NUM> in the axial direction and communicate with the frame discharge holes 132a to define the first refrigerant discharge passage together with the frame discharge holes 132a.

Scroll oil recovery grooves (hereinafter, referred to as second oil recovery grooves) 142b may be formed on the outer circumferential surface of the fixed side wall portion <NUM>. The second oil recovery grooves 142b may communicate with the first oil recovery grooves 132b provided at the main frame <NUM> to guide oil recovered along the first oil recovery grooves 132b to the oil storage space S3. Accordingly, the first oil recovery grooves 132b and the second oil recovery grooves 142b may define the second oil recovery passage together with oil recovery grooves 1612b and 162b of a flange portion <NUM> to be described later.

Meanwhile, a second suction passage <NUM> may be formed in the fixed side wall portion <NUM> to communicate with a first suction passage <NUM> formed in the discharge cover <NUM> to be described later. The second suction passage <NUM> may define a suction port.

The second suction passage <NUM> may be formed within a range of a suction chamber Vs of the compression unit to communicate with the suction chamber Vs. A suction passage opening and closing valve <NUM> may be installed in the second suction passage <NUM> to selectively open or close a suction passage <NUM> which includes the second suction passage <NUM> and the first suction passage <NUM>. The suction passage opening and closing valve <NUM> may also be referred to as a non-return valve, a suction valve, or a check valve.

The suction passage opening and closing valve <NUM> may be provided at a boundary surface between the first suction passage <NUM> and the second suction passage <NUM> to allow a fluid movement from the first suction passage <NUM> to the second suction passage <NUM> while blocking a reverse fluid movement from the second suction passage <NUM> to the first suction passage <NUM>.

Accordingly, during the operation of the compressor, refrigerant sucked through the refrigerant suction pipe <NUM> may be introduced into the suction chamber Vs through the suction passage <NUM> including the first suction passage <NUM> and the second suction passage <NUM>. On the other hand, when the compressor is stopped, the suction passage opening and closing valve <NUM> may close the suction passage <NUM> so that high-temperature oil contained in the oil storage space of the casing can be prevented from flowing back into the refrigerant suction pipe <NUM> together with high-temperature refrigerant compressed in the compression chamber. The suction passage including the second suction passage will be described later.

The sub bearing portion <NUM> may extend in the axial direction from a central portion of the fixed end plate <NUM> toward the discharge cover <NUM>. The sub bearing portion <NUM> may be provided with a sub bearing hole 143a formed in a cylindrical shape through a center thereof along the axial direction. A sub bearing <NUM> configured as a bush bearing may be fitted onto an inner circumferential surface of the sub bearing hole 143a.

Therefore, the lower end of the rotating shaft <NUM> may be inserted into the sub bearing portion <NUM> of the fixed scroll <NUM> to be supported in the radial direction, and the eccentric portion <NUM> of the rotating shaft <NUM> may be supported by the upper surface of the fixed end plate <NUM> defining the surrounding of the sub bearing portion <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> may be 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 will be described.

Referring to <FIG>, the orbiting scroll <NUM> according to the implementation may include an orbiting end plate <NUM>, an orbiting wrap <NUM>, and a rotating shaft coupling portion <NUM>.

The orbiting end plate <NUM> may be formed approximately in a disk shape. A back pressure sealing groove 151a into which the back pressure sealing member <NUM> is inserted may be formed in an upper surface of the orbiting end plate <NUM>. The back pressure sealing groove 151a may be formed at a position facing the scroll support portion <NUM> of the main frame <NUM>.

The back pressure sealing groove 151a may be formed in an annular shape to surround a rotating shaft coupling portion <NUM> to be described later, and may be eccentric with respect to an axial center of the rotating shaft coupling portion <NUM>. Accordingly, even if the orbiting scroll <NUM> performs an orbiting motion, a back pressure chamber (no reference numeral given) having a constant range may be defined between the orbiting scroll <NUM> and the scroll support portion <NUM> of the main frame <NUM>.

The orbiting end plate <NUM> may be further provided with a compression chamber oil supply hole <NUM>. One end of the compression chamber oil supply hole <NUM> may communicate with the oil accommodating portion <NUM>, and another end may communicate with an intermediate pressure chamber of the compression chamber. Accordingly, oil stored in the oil accommodating portion <NUM> may be supplied to the compression chamber V through the compression chamber oil supply hole <NUM> to lubricate the compression chamber.

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> may be 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, as illustrated in <FIG>, 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> may be rotatably inserted into the rotating shaft coupling portion <NUM>. An outer circumferential part of the rotating shaft coupling portion <NUM> may be connected to the orbiting wrap <NUM> to form 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 may 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 may be suppressed.

In addition, the rotating shaft coupling portion <NUM> may be provided with a concave portion 153a that is formed on an outer circumferential surface thereof, namely, an outer circumferential surface facing an inner end portion of the fixed wrap <NUM>, to be engaged with a protruding portion 144a of the fixed wrap <NUM> to be described later. A convex portion 153b may be formed at one side of the concave portion 153a. The convex portion 153b may be formed at an upstream side along a direction in which the compression chamber V is formed, and have a thickness increasing from an inner circumferential surface to an outer circumferential surface of the rotating shaft coupling portion <NUM>.

This may extend a compression path of the first compression chamber V1 immediately before discharge, and consequently the compression ratio of the first compression chamber V1 can be increased close to a pressure ratio of the second compression chamber V2. The first compression chamber V1 is a compression chamber formed between an inner surface of the fixed wrap <NUM> and an outer surface of the orbiting wrap <NUM>, and will be described later separately from the second compression chamber V2.

An arcuate compression surface 153c having an arcuate shape may be provided at another side of the concave portion 153a. The diameter of the arcuate compression surface 153c may be determined by a thickness of the inner end portion of the fixed wrap <NUM> (i.e., a thickness of a discharge end) and an orbiting radius of the orbiting wrap <NUM>.

For example, when the thickness of the inner end portion of the fixed wrap <NUM> increases, the diameter of the arcuate compression surface 153c may increase. As a result, a wrap thickness of the orbiting wrap around the arcuate compression surface 153c may increase to ensure durability and thus the compression path may extend to increase the compression ratio of the second compression chamber V2 to that extent.

The protruding portion 144a protruding toward the outer circumferential surface of the rotating shaft coupling portion <NUM> may be formed near the inner end portion (suction end or start end) of the fixed wrap <NUM> corresponding to the rotating shaft coupling portion <NUM>. Accordingly, a contact portion 144b may protrude from the protruding portion 144a to be engaged with the concave portion 153a.

In other words, the inner end portion of the fixed wrap <NUM> may be formed to have a larger thickness than other portions. As a result, wrap strength at the inner end portion of the fixed wrap <NUM>, which is subjected to the strongest compressive force on the fixed wrap <NUM>, may increase so as to enhance durability.

On the other hand, referring to <FIG>, the compression chamber V may be 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 formed between an inner surface of the fixed wrap <NUM> and an outer surface of the orbiting wrap <NUM>, and a second compression chamber V2 formed between an outer surface of the fixed wrap <NUM> and an inner surface of the orbiting wrap <NUM>.

In each of the first compression chamber V1 and the second compression chamber V2, a suction chamber Vs, an intermediate pressure chamber Vm, and a discharge chamber Vd may be continuously formed from outside to inside along an advancing direction of the wraps.

Here, the intermediate pressure chamber Vm and the discharge chamber Vd may be independently formed for each of the first compression chamber V1 and the second compression chamber V2. Accordingly, the first discharge port 141a may communicate with a discharge chamber Vd1 of the first compression chamber V1 and the second discharge port 141b may communicate with a discharge chamber Vd2 of the second compression chamber V2.

On the other hand, the suction chamber Vs may be formed to be shared by the first compression chamber V1 and the second compression chamber V2. That is, the suction chamber Vs may be formed at an outer side than the orbiting wrap <NUM> based on the advancing direction of the wrap. Specifically, the suction chamber Vs may be defined as a space formed in an area that the end of the orbiting wrap <NUM> does not reach, namely, outside an orbiting range of the orbiting wrap <NUM>, in a space formed between the inner circumferential surface of the fixed side wall portion <NUM> and an outer surface of the outermost fixed wrap <NUM> extending from the fixed side wall portion <NUM>.

Accordingly, the second suction passage <NUM> may be formed through the fixed end plate <NUM> in the axial direction to communicate with the suction chamber Vs, and the suction passage opening and closing valve <NUM> may not interfere with the orbiting wrap <NUM> even though it passes through the suction chamber Vs while moving in the second suction passage <NUM> in the axial direction along the fixed side wall portion <NUM>. This will be described later again together with the suction passage and the suction passage opening and closing valve.

On the other hand, an eccentric portion bearing <NUM> configured as a bush bearing may be fitted onto the inner circumferential surface of the rotating shaft coupling portion <NUM>. The eccentric portion <NUM> of the rotating shaft <NUM> may be rotatably inserted into the eccentric portion bearing <NUM>. Accordingly, the eccentric portion <NUM> of the rotating shaft <NUM> may be supported by the eccentric portion bearing <NUM> in the radial direction so as to perform a smooth orbiting motion with respect to the orbiting scroll <NUM>.

Here, the oil accommodating portion <NUM> may be formed inside the rotating shaft coupling portion <NUM>. The oil accommodating portion <NUM> may communicate with the compression chamber oil supply hole <NUM> that is formed through the orbiting end plate <NUM> in the radial direction.

The oil accommodating portion <NUM> may formed on the upper side of the eccentric portion bearing <NUM>. For example, an axial length of the eccentric portion bearing <NUM> may be shorter than an axial length (height) of the rotating shaft coupling portion <NUM>. Accordingly, a space corresponding to a difference in length between the eccentric portion bearing <NUM> and the rotating shaft coupling portion <NUM> and the thickness of the eccentric portion bearing <NUM> may be formed in an upper end of the eccentric portion bearing <NUM>. This space may communicate with the third oil hole 1262c or the first oil hole 1262a of the rotating shaft <NUM> to define the aforementioned oil accommodating portion <NUM>.

Alternatively, only one compression chamber oil supply hole <NUM> may be provided to communicate with any one of the first compression chamber V1 and the second compression chamber V2. However, in the illustrated implementation, the compression chamber oil supply hole <NUM> may include a first compression chamber oil supply hole <NUM> communicating with the first compression chamber V1, and a second compression chamber oil supply hole <NUM> communicating with the second compression chamber V2.

For example, one end, namely, an inlet of the first compression chamber oil supply hole <NUM> and one end, namely, an inlet of the second compression chamber oil supply hole <NUM> may communicate with the oil accommodating portion <NUM>, respectively, and another end, namely, an outlet of the first compression chamber oil supply hole <NUM> and another end, namely, an outlet of the second compression chamber oil supply hole <NUM> may communicate with the first compression chamber V1 and the second compression chamber V2, respectively.

Specifically, the outlets of the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may penetrate through the lower surface of the orbiting end plate <NUM> at a time point when suction in each compression chamber V1 and V2 is completed, namely, at a rotating angle of the orbiting wrap <NUM> greater than a rotating angle of the orbiting wrap <NUM>, at which the suction in each compression chamber V1 and V2 is completed.

Accordingly, the outlets of the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may be located at a downstream side more than the suction passage opening and closing valve <NUM> based on a direction that the refrigerant is sucked. Accordingly, when the compressor is stopped, oil which is intended to flow back toward the refrigerant suction pipe <NUM> through the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may be blocked by the suction passage opening and closing valve <NUM>, thereby preventing oil leakage from the compression chambers V1 and V2 toward the refrigerant suction pipe <NUM>.

Hereinafter, the discharge cover will be described.

Referring back to <FIG>, the discharge cover <NUM> may include a cover housing portion <NUM> and a cover flange portion <NUM>. The cover housing portion <NUM> may have a cover space 161a therein defining the discharge space S4 together with the fixed scroll <NUM>.

The cover housing portion <NUM> may include a housing bottom surface <NUM> and a housing side wall surface <NUM> extending in the axial direction from the housing bottom surface <NUM> to have a substantially annular shape.

Accordingly, the housing bottom surface <NUM> and the housing side wall surface <NUM> may define the cover space 161a for accommodating the outlets of the discharge ports 141a and 141b provided in the fixed scroll <NUM> and the inlet of the first discharge hole 142a, and the cover space 161a may define the discharge space S4 together with a surface of the fixed scroll <NUM> inserted into the cover space 161a.

A cover bearing protrusion <NUM> may protrude from a central portion of the housing bottom surface <NUM> toward the fixed scroll <NUM> in the axial direction, and a through hole 1613a may be formed through the inside of the cover bearing protrusion <NUM> in the axial direction.

The sub bearing portion <NUM> that protrudes from the rear surface of the fixed scroll <NUM>, namely, the fixed end plate <NUM> in a downward direction (axial direction) may be inserted into the through hole 1613a. A cover sealing member <NUM> for sealing a gap between an inner circumferential surface of the through hole 1613a and an outer circumferential surface of the sub bearing portion <NUM> may be inserted into the gap.

The housing side wall surface <NUM> may extend outward from an outer circumferential surface of the cover housing portion <NUM> so as to be coupled in close contact with the lower surface of the fixed scroll <NUM>. In addition, at least one discharge guide groove 1612a may be formed on an inner circumferential surface of the housing side wall surface <NUM> along the circumferential direction.

The discharge guide groove 1612a may be recessed outward in the radial direction, and the first discharge hole 142a of the fixed scroll <NUM> defining a first refrigerant discharge passage may be formed to be positioned inside the discharge guide groove 1612a. Accordingly, an inner surface of the housing side wall surface <NUM> excluding the discharge guide groove 1612a may be 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 configure a type of sealing part.

Here, an entire circumferential angle of the discharge guide groove 1612a 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 S4 except for the discharge guide groove 1612a. In this manner, the inner circumferential surface of the discharge space S4 except for the discharge guide groove 1612a can secure not only a sufficient sealing area but also a circumferential length for forming the cover flange portion <NUM> to be described later.

The housing side wall surface <NUM> may be provided with oil recovery grooves 1612b formed on an outer circumferential surface thereof with a preset interval along the circumferential direction so as to define a third oil recovery groove. For example, the oil recovery groove 1612b may be formed on the outer circumferential surface of the housing side wall surface <NUM>. The oil recovery groove 1612b may define the third oil recovery groove together with oil recovery grooves 162b of the cover flange portion <NUM> to be described later. The third oil recovery groove of the discharge cover <NUM> may define the second oil recovery passage together with the first oil recovery groove of the main frame <NUM> and the second oil recovery groove of the fixed scroll <NUM>.

The cover flange portion <NUM> may extend radially from a portion defining the sealing part, namely, from an outer circumferential surface of a portion, excluding the discharge guide groove 1612a, of the housing side wall surface <NUM> of the cover housing 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 recovery grooves 162b formed between the neighboring coupling holes 162a at preset intervals in the circumferential direction.

The oil recovery grooves 162b formed on the cover flange portion <NUM> may define the third oil recovery groove together with the oil recovery groove 1612b formed on the housing side wall surface <NUM>. The oil recovery grooves 162b formed on the cover flange portion <NUM> may be recessed inward (toward a center) in the radial direction from an outer circumferential surface of the cover flange portion <NUM>.

Meanwhile, the first suction passage <NUM> may be formed in the discharge cover <NUM>, and the refrigerant suction pipe <NUM> may communicate with the second suction passage <NUM> of the fixed scroll <NUM> through the first suction passage <NUM>. The refrigerant suction pipe <NUM> inserted through the cylindrical shell <NUM> may be inserted into an inlet of the first suction passage <NUM> so as to communicate directly with the first suction passage <NUM>. An outlet of the first suction passage <NUM> may communicate with the second suction passage <NUM> of the fixed scroll <NUM>. In addition, the outlet of the first suction passage <NUM> may be selectively opened and closed by the suction passage opening and closing valve <NUM> inserted into the second suction passage <NUM>.

Accordingly, refrigerant circulating in the refrigeration cycle during the operation of the compressor may flow into the first suction passage <NUM> of the discharge cover <NUM> through the refrigerant suction pipe <NUM>. The refrigerant may open the suction passage opening and closing valve <NUM> so as to be introduced into the suction chamber Vs through the second suction passage <NUM>.

In the drawings, unexplained reference numeral <NUM> denotes a condenser fan, <NUM> denotes an evaporator fan, and <NUM> denotes a suction guide protrusion.

Hereinafter, an operation of the high-pressure and bottom-compression type scroll compressor according to the implementation will be described.

That is, when power is applied to the motor unit <NUM>, rotational force may be generated and the rotor <NUM> and the rotating shaft <NUM> may rotate accordingly. As the rotating shaft <NUM> rotates, the orbiting scroll <NUM> eccentrically coupled to the rotating shaft <NUM> may perform an orbiting motion by the Oldham ring <NUM>.

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

Then, refrigerant may move to the accumulator <NUM> sequentially via the condenser <NUM>, the expansion apparatus <NUM>, and the evaporator <NUM> of the refrigeration cycle. The refrigerant may flow toward the suction chamber Vs forming the compression chamber V through the refrigerant suction pipe <NUM>.

The refrigerant sucked into the suction chamber Vs may be compressed while moving to the discharge chamber Vd via the intermediate pressure chamber Vm along a movement trajectory of the compression chamber V. The compressed refrigerant may be discharged from the discharge chamber Vd to the discharge space S4 of the discharge cover <NUM> through the discharge ports 141a and 141b.

The refrigerant discharged into the discharge space S4 of the discharge cover <NUM> may then flow into the inner space 110a of the casing <NUM> through the discharge guide groove 1612a of the discharge cover <NUM> and the first discharge holes 142a of the fixed scroll <NUM>. The refrigerant may flow to the lower space S1 between the main frame <NUM> and the driving motor <NUM> and then move toward the upper space S2 of the casing <NUM>, which is defined above the driving motor <NUM>, through a gap between the stator <NUM> and the rotor <NUM>.

However, oil may be separated from the refrigerant in the upper space S2 of the casing <NUM>, and the oil-separated refrigerant may be discharged to the outside of the casing <NUM> through the refrigerant discharge pipe <NUM> so as to flow to the condenser <NUM> of the refrigeration cycle.

On the other hand, the oil separated from the refrigerant in the inner space 110a of the casing <NUM> may be recovered into the oil storage space S3 defined in the lower portion of the compression unit through the first oil recovery passage between the inner circumferential surface of the casing <NUM> and the stator <NUM> and the second oil recovery passage between the inner circumferential surface of the casing <NUM> and the outer circumferential surface of the compression unit. This oil may thusly be supplied to each bearing surface (not shown) through the oil supply passage <NUM>, and partially supplied into the compression chamber V. The oil supplied to the bearing surface and the compression chamber V may be discharged to the discharge cover <NUM> together with the refrigerant and recovered. This series of processes may be repeatedly performed.

On the other hand, when the compressor <NUM> is stopped, the refrigeration cycle including the compressor <NUM> may perform an operation to enter a so-called pressure equilibrium state. At this time, the oil or refrigerant filled in the inner space 110a of the casing <NUM> may flow back toward the refrigerant suction pipe <NUM>. Due to the back flow of the oil or refrigerant, a specific volume of suction refrigerant may be increased and suction loss may be increased thereby. Also, upon restart of a refrigeration cycle, an oil shortage may be caused, thereby lowering reliability and performance of the compressor.

However, the back flow of the oil or refrigerant may be suppressed by a suction passage opening and closing valve <NUM> that is installed in the middle of the suction passage <NUM>, for example, in the middle between the first suction passage <NUM> and the second suction passage <NUM> so as to configure a kind of check valve. The suction passage opening and closing valve <NUM> may block the suction passage <NUM> when the compressor is stopped, thereby preventing the oil or refrigerant in the casing <NUM> from flowing back toward the suction passage <NUM> through the compression unit.

In this way, in the scroll compressor of the high-pressure type and the bottom-compression type, as the suction passage opening and closing valve is installed between an outlet of the refrigerant suction pipe and an inlet of the compression unit, the oil or refrigerant in the casing can be quickly prevented from flowing back to the refrigerant suction pipe through the compression unit when the compressor is stopped. Accordingly, upon the restart of the compressor, an increase in a specific volume of the refrigerant can be suppressed and friction loss due to a shortage of oil can be reduced, thereby improving compression efficiency.

As the suction passage opening and closing valve is operated in the axial direction, the structure of the suction passage opening and closing valve can be simplified, which may result in reducing a fabricating cost and simultaneously improving responsiveness of the valve, thereby enhancing the compression efficiency.

In addition, as the suction passage is formed in the discharge cover or the fixed scroll, the suction passage may be formed in an oil storage space located below the compression unit, so that the compressor can be reduced in size while maintaining its axial length.

On the other hand, as described above, when different oil supply paths (for example, a first oil supply hole and a second oil supply hole) are formed to communicate individually with the first and second compression chambers, at least one of the different oil supply paths may be opened toward the corresponding compression chamber.

In particular, crank angle ranges (e.g., a first crank angle range in which the first oil supply hole is open and a second crank angle range in which the second oil supply hole is open) in which the different oil supply paths are open to the corresponding compression chambers may be formed to overlap each other within a preset crank angle range.

In other words, crank angle ranges (e.g., first and second crank angle ranges) in which the respective oil supply paths are open may have an overlap range. Then, even if the orbiting scroll performs the orbiting motion during the operation of the compressor, at least one oil supply path may be open, such that oil can be fed to the compression unit without interruption, thereby suppressing friction loss.

However, if the first crank angle range and the second crank angle range overlap each other within a preset crank angle range, it may be advantageous in terms of oil supply, but may be disadvantageous in terms of compression efficiency. For example, when a pressure difference between the first compression chamber and the second compression chamber occurs, a phenomenon in which refrigerant compressed in a high-pressure side partially flows back to a low pressure-side may occur in the section where the first crank angle range and the second crank angle range overlap each other. As a result, compression loss may be increased and compression efficiency may be decreased.

Therefore, in the implementation of the present disclosure, a first compression chamber oil supply hole communicating with a first compression chamber and a second compression chamber oil supply hole communicating with the second compression chamber may be individually provided, so as to prevent both the compression chambers from communicating with each other through the first compression chamber oil supply hole and the second compression chamber oil supply hole.

<FIG> is a perspective view of an orbiting scroll in accordance with an implementation of the present disclosure, <FIG> is a planar view of the orbiting scroll according to <FIG>, viewed from the top, <FIG> is a sectional view taken along the line "V-V" in <FIG>, which illustrates a first compression chamber oil supply hole of the orbiting scroll, and <FIG> is a sectional view taken along the line "VI-VI" in <FIG>, which illustrates a second compression chamber oil supply hole of the orbiting scroll.

Referring to <FIG>, a first compression chamber oil supply hole <NUM> and a second compression chamber oil supply hole <NUM> according to an implementation may be formed in the orbiting end plate <NUM>.

For example, the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may penetrate through the inside of the orbiting end plate <NUM> in the radial direction from an inner circumferential surface of the rotating shaft coupling portion <NUM>, and then penetrate through a side surface of the orbiting end plate <NUM> facing the fixed end plate <NUM>. Accordingly, the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may allow the oil accommodating portion <NUM>, which is provided in the rotating shaft coupling portion <NUM>, more precisely, the upper end of the eccentric portion bearing <NUM>, to communicate with the first compression chamber V1 and the second compression chamber V2, respectively.

The first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may have the same basic configuration, except for positions where outlets of those oil supply holes communicate with the first compression chamber V1 and the second compression chamber V2, respectively. Hereinafter, the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> will be described sequentially.

Referring to <FIG> and <FIG>, the first compression chamber oil supply hole <NUM> may include a first oil supply inlet portion 1561a, a first oil supply connection portion 1561b, a first oil supply penetration portion 1561c, and a first oil supply outlet portion 1561d. Accordingly, oil inside the oil accommodating portion <NUM> may be supplied to the first compression chamber V1 sequentially via the first oil supply inlet portion 1561a, the first oil supply connection portion 1561b, the first oil supply penetration portion 1561c, and the first oil supply outlet portion 1561d.

The first oil supply inlet portion 1561a may have an inlet end communicating with an inner circumferential surface of the oil accommodating portion <NUM> to define an inlet of the first compression chamber oil supply hole <NUM>. For example, the first oil supply inlet portion 1561a may be recessed into the upper surface of the orbiting end plate <NUM> by a preset depth and extend in the radial direction. Accordingly, oil contained in the oil accommodating portion <NUM> may move to the first oil supply inlet portion 1561a and spread to the upper surface of the orbiting scroll <NUM> at an inner space (e.g., back pressure chamber) of the back pressure sealing member <NUM>, thereby smoothly lubricating a gap between the main frame <NUM> and the orbiting scroll <NUM>.

The first oil supply inlet portion 1561a may extend in a direction in which the back pressure sealing groove 151a is eccentric from the rotating shaft coupling portion <NUM> at an inner side than the back pressure sealing grove 151a. However, considering the fact that a first pressure reducing member 1565a is installed inside the first oil supply penetration portion 1561c, a length of the first oil supply inlet portion 1561a may preferably be as short as possible.

The first oil supply connection portion 1561b may extend in the axial direction from an end of the first oil supply inlet portion 1561a and be recessed by an intermediate depth of the orbiting end plate <NUM>. Accordingly, oil flowing into the first oil supply inlet portion 1561a may move toward the first oil supply penetration portion 1561c through the first oil supply connection portion 1561b.

The first oil supply penetration portion 1561c may be formed through the inside of the orbiting end plate <NUM> in the radial direction. Since the first oil supply penetration portion 1561c may be made in a direction from an outer circumferential surface to an inner circumferential surface of the orbiting end plate <NUM>, a blocking bolt (not shown) may be coupled to an outer end of the first oil supply penetration portion 1561c, so as to seal the outer end of the first oil supply penetration portion 1561c.

The first pressure reducing member 1565a may be inserted into the oil supply penetration portion 1561c. The first pressure reducing member 1565a may be configured as a pressure reducing pin having an outer diameter smaller than an inner diameter of the first oil supply penetration portion 1561c. Accordingly, oil in the oil accommodating portion <NUM> may be decompressed while passing through the first pressure reducing member 1565a inside the oil supply penetration portion 1561c and then supplied to the first compression chamber V1.

The first oil supply outlet portion 1561d may penetrate through the lower surface of the orbiting end plate <NUM> at an end portion of the first oil supply penetration portion 1561c in the radial direction. Accordingly, the first compression chamber oil supply hole <NUM> may allow the communication between the oil accommodating portion <NUM> and the first compression chamber V1.

The first oil supply outlet portion 1561d may be formed at a position spaced apart from an outer circumferential surface of the outermost orbiting wrap <NUM> by a preset interval. As described above, the first oil supply outlet portion 1561d may penetrate through a surface facing the fixed end plate <NUM>, namely, the lower surface of the orbiting end plate <NUM>, at the outer end portion of the first oil supply penetration portion 1561c. The first oil supply outlet portion 1561d may have an inner diameter which is smaller than or equal to an inner diameter of the first oil supply penetration portion 1561c, for example, smaller than a wrap thickness of the fixed wrap <NUM>. The outermost orbiting wrap is an outer portion of the orbiting wrap <NUM>, which is not surrounded radially by other portions of the orbiting wrap <NUM>. In other words, from a view of a radial cross-section of the orbiting wrap <NUM>, as shown in <FIG>, the outermost orbiting wrap is a portion of the orbiting wrap <NUM>, which is located most radially outside.

On the other hand, the second compression chamber oil supply hole <NUM> may be formed almost similar to the first compression chamber oil supply hole <NUM>.

Referring to <FIG> and <FIG>, the second compression chamber oil supply hole <NUM> may include a second oil supply inlet portion 1562a, a second oil supply connection portion 1562b, a second oil supply penetration portion 1562c, and a second oil supply outlet portion 1562d. Accordingly, oil inside the oil accommodating portion <NUM> may be supplied to the second compression chamber V2 sequentially via the second oil supply inlet portion 1562a, the second oil supply connection portion 1562b, the second oil supply penetration portion 1562c, and the second oil supply outlet portion 1562d.

The second oil supply inlet portion 1562a may have an inlet end communicating with an inner circumferential surface of the oil accommodating portion <NUM> to define an inlet of the second compression chamber oil supply hole <NUM>. For example, the second oil supply inlet portion 1562a may be recessed into the upper surface of the orbiting end plate <NUM> by a preset depth and extend in the radial direction. Accordingly, oil contained in the oil accommodating portion <NUM> may move to the second oil supply inlet portion 1562a and spread to the upper surface of the orbiting scroll <NUM> at an inner space (e.g., back pressure chamber) of the back pressure sealing member <NUM>, thereby smoothly lubricating a gap between the main frame <NUM> and the orbiting scroll <NUM>.

The second oil supply inlet portion 1562a may extend in a direction in which the back pressure sealing groove 151a is eccentric from the rotating shaft coupling portion <NUM> at an inner side than the back pressure sealing grove 151a. However, considering the fact that a second pressure reducing member 1565a is installed inside the second oil supply penetration portion 1562c, a length of the second oil supply inlet portion 1562a may preferably be as short as possible.

The second oil supply connection portion 1562b may extend in the axial direction from an end of the second oil supply inlet portion 1562a and be recessed by an intermediate depth of the orbiting end plate <NUM>. Accordingly, oil flowing into the second oil supply inlet portion 1562a may move toward the first oil supply penetration portion 1562c through the second oil supply connection portion 1561b.

The second oil supply penetration portion 1562c may be formed through the inside of the orbiting end plate <NUM> in the radial direction. Since the second oil supply penetration portion 1562c may be made in a direction from an outer circumferential surface to an inner circumferential surface of the orbiting end plate <NUM>, a blocking bolt (not shown) may be coupled to an outer end of the second oil supply penetration portion 1562c, so as to seal the outer end of the second oil supply penetration portion 1562c.

The second pressure reducing member 1565a may be inserted into the second oil supply penetration portion 1562c. The second pressure reducing member 1565a may be configured as a pressure reducing pin having an outer diameter smaller than an inner diameter of the second oil supply penetration portion 1562c. Accordingly, oil in the oil accommodating portion <NUM> may be decompressed while passing through the second pressure reducing member 1565a inside the second oil supply penetration portion 1562c and then supplied to the second compression chamber V2.

The second oil supply outlet portion 1562d may penetrate through the lower surface of the orbiting end plate <NUM> at an end portion of the second oil supply penetration portion 1562c in the radial direction. Accordingly, the second compression chamber oil supply hole <NUM> may allow the communication between the oil accommodating portion <NUM> and the second compression chamber V2.

The second oil supply outlet portion 1562d may be formed at a position spaced apart from an inner circumferential surface of the outermost orbiting wrap <NUM> by a preset interval. As described above, the second oil supply outlet portion 1562d may penetrate through a surface facing the fixed end plate <NUM>, namely, the lower surface of the orbiting end plate <NUM>, near the outer end of the first oil supply penetration portion 1562c. The second oil supply outlet portion 1562d may have an inner diameter which is smaller than or equal to an inner diameter of the second oil supply penetration portion 1562c, for example, smaller than a wrap thickness of the fixed wrap <NUM>.

On the other hand, the first oil supply outlet portion 1561d forming the outlet of the first compression chamber oil supply hole <NUM> may be formed at a position where it communicates with the first compression chamber V1, regardless of an orbiting position (crank angle) of the orbiting scroll <NUM>, and the second oil supply outlet portion 1562d forming the outlet of the second compression chamber oil supply hole <NUM> may be formed at a position where it communicates with the second compression chamber V2, regardless of the orbiting position (crank angle) of the orbiting scroll <NUM>.

<FIG> is a planar view illustrating an appropriate position of an outlet of the first compression chamber oil supply hole in <FIG>. (a) of <FIG> illustrates the position of the first compression chamber (pocket A) when the crank angle is <NUM>°, and (b) of <FIG> illustrates the position of the first compression chamber (pocket A) when the crank angle is <NUM>°. Also, (c) of <FIG> illustrates the position of the first compression chamber (pocket A) when the crank angle is <NUM>°. In addition, (a+b+c) of <FIG> illustrates a portion where the positions of the first compression chamber (pocket A) in (a), (b), and (c) of <FIG> overlap. Hereinafter, an angle is a crank angle unless otherwise specified.

Referring to (a) of <FIG>, the first compression chamber (pocket A) V1 may be shown at a time point when a compression stroke starts just after completion of a suction stroke. In this case, the first compression chamber (pocket A) V1 may be formed in a crank angle range of approximately <NUM>° to <NUM>°. Therefore, considering only (a) of <FIG>, it may be appropriate that the outlet (first oil supply outlet portion) 1561d of the first compression chamber oil supply hole <NUM> is located within the crank angle range V11 of approximately <NUM>° to <NUM>°.

Referring to (b) of <FIG>, the first compression chamber (pocket A) V1 may be shown at a time point when the compression stroke is in progress after moving along an orbiting trajectory of the orbiting scroll <NUM>. In this case, the first compression chamber (pocket A) V1 may be formed in a crank angle range of approximately <NUM>° to <NUM>°. Therefore, considering only (b) of <FIG>, it may be appropriate that the outlet (first oil supply outlet portion) 1561d of the first compression chamber oil supply hole <NUM> is located within the crank angle range V12 of approximately <NUM>° to <NUM>°.

Referring to (c) of <FIG>, the first compression chamber (pocket A) V1 may be shown at a time point when the compression stroke is further in progress after moving along the orbiting trajectory of the orbiting scroll <NUM>. In this case, the first compression chamber (pocket A) V1 may be formed in a crank angle range of approximately <NUM>° to <NUM>°. Therefore, considering only (c) of <FIG>, it may be appropriate that the outlet (first oil supply outlet portion) 1561d of the first compression chamber oil supply hole <NUM> is located within the crank angle range V13 of approximately <NUM>° to <NUM>°.

However, when only one first compression chamber oil supply hole <NUM> is formed in the first compression chamber V1, the first compression chamber oil supply hole <NUM> may preferably be formed to be included in the range of the first compression chamber V1 at each crank angle exemplarily illustrated above. Accordingly, when viewing (a+b+c) of <FIG>, the first oil supply outlet portion 1561d as the outlet of the first compression chamber oil supply hole <NUM> may be formed in a section included in all cases where the crank angle is <NUM>°, <NUM>°, and <NUM>°, that is, in a crank angle range V11+V12+V13 in which regions of the first compression chamber at the respective crank angles overlap together.

Accordingly, the first oil supply outlet portion 1561d according to the implementation may be formed within a crank angle range of approximately <NUM>° to <NUM>°. However, considering the inner diameter of the first oil supply outlet portion 1561d, the first oil supply outlet portion 1561d may preferably be formed within a crank angle range of approximately <NUM>° to <NUM>°.

On the other hand, <FIG> is a planar view illustrating an appropriate position of an outlet of the second compression chamber oil supply hole in <FIG>. (a) of <FIG> illustrates the position of the second compression chamber (pocket B) when the crank angle is <NUM>°, and (b) of <FIG> illustrates the position of the second compression chamber (pocket B) when the crank angle is <NUM>°. Also, (c) of <FIG> illustrates the position of the second compression chamber (pocket B) when the crank angle is <NUM>°. In addition, (a+b+c) of <FIG> illustrates a portion where the positions of the second compression chamber (pocket B) in (a), (b), and (c) of <FIG> overlap. Hereinafter, an angle is also the crank angle unless otherwise specified.

Referring to (a) of <FIG>, the second compression chamber (pocket B) V2 may be shown at a time point when a compression stroke starts just after completion of a suction stroke. In this case, the second compression chamber (pocket B) V2 may be formed in a crank angle range V21 of approximately -<NUM>° to <NUM>°. Therefore, considering only (a) of <FIG>, it may be appropriate that the outlet (second oil supply outlet portion) 1562d of the second compression chamber oil supply hole <NUM> is located within the crank angle range of approximately -<NUM>° to <NUM>°.

Referring to (b) of <FIG>, the second compression chamber (pocket B) V2 may be shown at a time point when the compression stroke is in progress after moving along an orbiting trajectory of the orbiting scroll <NUM>. In this case, the second compression chamber (pocket B) V2 may be formed in a crank angle range of approximately <NUM>° to <NUM>°. Therefore, considering only (b) of <FIG>, it may be appropriate that the outlet (second oil supply outlet portion) 1562d of the second compression chamber oil supply hole <NUM> is located within the crank angle range of approximately <NUM>° to <NUM>°.

Referring to (c) of <FIG>, the second compression chamber (pocket B) V2 may be shown at a time point when the compression stroke is further in progress after moving along the orbiting trajectory of the orbiting scroll <NUM>. In this case, the second compression chamber (pocket B) V2 may be formed in a crank angle range V23 of approximately <NUM>° to <NUM>°. Therefore, considering only (c) of <FIG>, it may be appropriate that the outlet (second oil supply outlet portion) 1562d of the second compression chamber oil supply hole <NUM> is located within the crank angle range of approximately <NUM>° to <NUM>°.

However, when only one second compression chamber oil supply hole <NUM> is formed in the second compression chamber V2, the second compression chamber oil supply hole <NUM> may preferably be formed to be included in the range of the compression chamber at each crank angle exemplarily illustrated above. Accordingly, when viewing (a+b+c) of <FIG>, the second oil supply outlet portion 1562d as the outlet of the second compression chamber oil supply hole <NUM> may be formed in a section included in all cases where the crank angle is <NUM>°, <NUM>°, and <NUM>°, that is, in a crank angle range V21+V22+V23 in which regions of the second compression chamber at the respective crank angles overlap together.

Accordingly, the second oil supply outlet portion 1562d according to the implementation may be formed within a crank angle range of approximately <NUM>° to <NUM>°. However, considering the inner diameter of the second oil supply outlet portion 1562d, the second oil supply outlet portion 1562d may preferably be formed within a crank angle range of approximately <NUM>° to <NUM>°.

On the other hand, the position of the first oil supply outlet portion 1561d and the position of the second oil supply outlet portion 1562d may be linked to a design pressure ratio, respectively.

That is, when the design pressure ratio is <NUM> to <NUM> (first pressure ratio range), the first oil supply outlet portion 1561d may be formed in the range of <NUM>° to <NUM>°, and the second oil supply outlet portion 1562d may be formed in the range of <NUM>° to <NUM>°.

In addition, when the design pressure ratio is <NUM> to <NUM> (second pressure ratio range), the first oil supply outlet portion 1561d may be formed in the range of <NUM>° to <NUM>°, and the second oil supply outlet portion 1562d may be formed in the range of <NUM>° to <NUM>°.

In addition, when the design pressure ratio is <NUM> to <NUM> (third pressure ratio range), the first oil supply outlet portion 1561d may be formed in the range of <NUM>° to <NUM>° and the second oil supply outlet portion 1562d may be formed in the range of <NUM>° to <NUM>°.

On the other hand, the first oil supply outlet portion 1561d may be formed at a position where the first compression chamber oil supply hole <NUM> communicates with the first compression chamber V1 and the second compression chamber oil supply hole <NUM> communicates with the second compression chamber V2, independently, regardless of the orbiting position (crank angle) of the orbiting scroll <NUM>.

<FIG> is a planar view, when viewing the orbiting scroll from the bottom, for explaining appropriate spaced distances of the first compression chamber oil supply hole and the second compression chamber oil supply hole in <FIG> from the orbiting wrap.

Referring to <FIG>, the first oil supply outlet portion 1561d forming the outlet of the first compression chamber oil supply hole <NUM> may be formed at a position spaced apart from the outer circumferential surface of the outermost orbiting wrap <NUM> by a preset interval, and the second oil supply outlet portion 1562d forming the outlet of the second compression chamber oil supply hole <NUM> may be formed at a position spaced apart from the inner circumferential surface of the outermost orbiting wrap <NUM> by a preset interval.

For example, when the position of the first oil supply outlet portion 1561d is defined as a first oil supply position P1, the position of the second oil supply outlet portion 1562d is defined as a second oil supply position P2, a radial distance from the outer circumferential surface of the outermost orbiting wrap <NUM> to the first oil supply position P1 is defined as a first outlet distance L1, and a radial distance from the inner circumferential surface of the outermost orbiting wrap <NUM> to the second oil supply position P2 is defined as a second outlet distance L2, the positions of the first oil supply outlet portion 1561d and the second oil supply outlet portion 1562d may be calculated (determined or set), respectively.

That is, the position of the first oil supply outlet portion 1561d and the position of the second oil supply outlet portion 1562d according to the implementation may be determined such that the first outlet distance L1 is greater than or equal to a value obtained by subtracting the inner diameter d1 of the first oil supply outlet portion 1561d from the wrap thickness t of the orbiting wrap <NUM> and the second outlet distance L2 is greater than or equal to a value obtained by subtracting the inner diameter d2 of the second oil supply outlet portion 1562d from the wrap thickness t of the orbiting wrap <NUM>. This may be expressed by the following relation.

In other words, the first oil supply outlet portion 1561d according to the implementation may be formed at a position spaced apart from the outer circumferential surface of the outermost orbiting wrap <NUM> by the inner diameter d1 of the first oil supply outlet portion 1561d or farther, and the second oil supply outlet portion 1562d according to the implementation may be formed at a position spaced apart from the inner circumferential surface of the outermost orbiting wrap <NUM> by the inner diameter d2 of the second oil supply outlet portion 1562d or farther.

Here, the first outlet distance L1 may be greater than or equal to the second outlet distance L2. This will be described in detail later with reference to <FIG>.

Accordingly, when the orbiting scroll <NUM> performs the orbiting motion relative to the fixed scroll <NUM>, the first compression chamber oil supply hole <NUM> (precisely, the first oil supply outlet portion) may almost communicate only with the first compression chamber V1 and the second compression chamber oil supply hole <NUM> (precisely, the second oil supply outlet portion) may almost communicate only with the second compression chamber V2.

<FIG> is a schematic view illustrating open sections of the respective compression chamber oil supply holes according to positions of the first compression chamber oil supply hole and the second compression chamber oil supply hole in accordance with an implementation of the present disclosure. (a) of <FIG> illustrates implementations in which the position of the first oil supply outlet portion is divided into three stages and the position of the second oil supply outlet portion is divided into two stages. (b) of <FIG> shows graphs that analyze an crank angle range of each compression chamber based on a crank angle in the case of the division shown in (a) of <FIG>.

As illustrated in (a) and (b) of <FIG>, when the first oil supply outlet portion 1561d is formed at a position ① adjacent to an outer circumferential surface 152a of the orbiting wrap <NUM> and the second oil supply outlet portion 1562d is formed at a position ①' adjacent to an inner circumferential surface 152b of the orbiting wrap <NUM>, a first crank angle range in which the first oil supply outlet portion 1561d communicates with the first compression chamber V1 corresponds to a crank angle range of approximately -<NUM>° to <NUM>° and a second crank angle range in which the second oil supply outlet portion 1562d communicates with the second compression chamber V2 corresponds to a crank angle range of approximately <NUM>° to <NUM>°. [See a top graph in (b) of <FIG>].

Accordingly, a section in which the first crank angle range As1 and the second crank angle range As2 overlap each other, that is, a section in which the first compression chamber V1 and the second compression chamber V2 communicate with each other corresponds to approximately <NUM>° to <NUM>° (first overlap range) Ao1 and to approximately <NUM>° to <NUM>° (second overlap range) Ao2. These first overlap range Ao1 and second overlap range Ao2 are slashed in (b) of <FIG>.

In these overlap ranges Ao1 and Ao2, the first compression chamber V1 and the second compression chamber V2 may communicate with each other through the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM>. Then, a back flow of refrigerant from the first compression chamber V1 to the second compression chamber V2 may occur in the first overlap range Ao1 and a back flow of refrigerant from the second compression chamber V2 to the first compression chamber V1 may occur in the second overlap range Ao2, due to a pressure difference between the first and second compression chambers V1 and V2.

Referring back to (a) and (b) of <FIG>, when the first oil supply outlet portion 1561d is formed at a position ② farther spaced apart from the outer circumferential surface 152a of the orbiting wrap <NUM> and the second oil supply outlet portion 1562d is formed at a position ②'farther spaced apart from the inner circumferential surface 152b of the orbiting wrap <NUM>, the first crank angle range As1 in which the first oil supply outlet portion 1561d communicates with the first compression chamber V1 corresponds to a crank angle range of approximately - <NUM>° to <NUM>° and the second crank angle range As2 in which the second oil supply outlet portion 1562d communicates with the second compression chamber V2 corresponds to a crank angle range of <NUM>° to <NUM>°. [See a middle graph of (b) of <FIG>].

Accordingly, a section in which the first crank angle range As1 of the first compression chamber V1 and the second crank angle range V2 of the second compression chamber V2 overlap each other, that is, a section in which the first compression chamber V1 and the second compression chamber V2 communicate with each other corresponds to approximately <NUM>° to <NUM>° (overlap range) Ao1 and to approximately <NUM>° to <NUM>° (overlap range) Ao1. These overlap ranges Ao1 and Ao2 are slashed in (b) of <FIG>.

In these overlap ranges Ao1 and Ao2, as aforementioned, the first compression chamber V1 and the second compression chamber V2 may communicate with each other through the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM>. Then, a back flow of refrigerant from the first compression chamber V1 to the second compression chamber V2 may occur in the overlap ranges Ao1 and Ao2 due to a pressure difference between the first and second compression chambers V1 and V2.

However, in this case, as described above, the overlap ranges Ao1 and Ao2 may be shortened, compared to those formed when the first oil supply outlet portion 1561d and the second oil supply outlet portion 1562d are disposed adjacent to the side surface of the orbiting wrap <NUM>, thereby reducing leakage between the compression chambers by that much.

Referring back to (a) and (b) of <FIG>, when the first oil supply outlet portion 1561d is formed at a position ③ farthest spaced apart from the outer circumferential surface 152a of the orbiting wrap <NUM> and the second oil supply outlet portion 1562d is formed at a position ③'farther spaced apart from the inner circumferential surface 152b of the orbiting wrap <NUM>, the first crank angle range As1 in which the first oil supply outlet portion 1561d communicates with the first compression chamber V1 corresponds to a section in a crank angle range of approximately <NUM>° to <NUM>° and the second crank angle range As2 in which the second oil supply outlet portion 1562d communicates with the second compression chamber V2 corresponds to a section in a crank angle range of <NUM>° to <NUM>°.

Here, the position of ③' is the same as that the position ②'. Therefore, the distance (the first outlet distance L1) from the outer circumferential surface of the orbiting wrap <NUM> to the first oil supply outlet portion <NUM> may be longer than the distance (the second outlet distance L2) from the inner circumferential surface of the orbiting wrap <NUM> to the second oil supply outlet portion <NUM>. [See a bottom graph of (b) of <FIG>].

Accordingly, a section in which the first crank angle range As1 of the first compression chamber V1 and the second crank angle range As2 of the second compression chamber V2 overlap each other, that is, an overlap range in which the first compression chamber V1 and the second compression chamber V2 communicate with each other may hardly occur.

This may allow oil to be smoothly supplied to the first compression chamber V1 and the second compression chamber V2, so as to reduce friction loss in the compression unit and prevent leakage between the compression chambers through the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM>. This may result in enhancing compression efficiency.

In addition, a non-oil supply crank angle range As3 may be formed between the start of the first crank angle range As1 and the end of the second crank angle range As2 based on the crank angle. That is, as illustrated in (b) of <FIG>, the non-oil supply crank angle range As3, in which oil is not supplied because the first oil supply outlet portion 1561d and the second oil supply outlet portion 1562d are blocked, may be formed between the start of the first crank angle range As1 and the end of the second crank angle range As2. This non-oil supply crank angle range As3 may be formed to be greater than <NUM>° and smaller than or equal to <NUM>°. In this way, the non-oil supply crank angle range in which oil is not supplied to the compression chambers V1 and V2 can be minimized so as to reduce friction loss as much as possible.

On the other hand, the foregoing implementation illustrates the oil supply structure in the scroll compressor having the suction passage opening and closing valve disposed in the suction passage. However, in some cases, the oil supply structure may also be equally applied to a scroll compressor in which the suction passage opening and closing valve is not disposed in the suction passage.

<FIG> is a longitudinal sectional view illustrating another implementation of a scroll compressor, to which the compression chamber oil supply holes according to the present disclosure are applied.

Referring to <FIG>, a basic structure of a scroll compressor according to this implementation is the same as that of the foregoing implementation illustrated in <FIG>, and thus a description thereof will be replaced with the description of the foregoing implementation.

For example, in the scroll compressor according to this implementation, the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may be provided to communicate with the first compression chamber V1 and the second compression chamber V2, respectively.

The first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM> may be formed in the same manner as in the foregoing implementation. Specifically, the crank angle range of the first oil supply outlet portion 1561d forming the outlet of the first compression chamber oil supply hole <NUM> and the second oil supply outlet portion 1562d forming the outlet of the second compression chamber oil supply hole <NUM> may not overlap each other. The positions of the first oil supply outlet portion 1561d and the second oil supply outlet portion 1562d are the same as those of the foregoing implementation.

Accordingly, the first compression chamber V1 and the second compression chamber V2 can be prevented from communicating with each other through the first compression chamber oil supply hole <NUM> and the second compression chamber oil supply hole <NUM>, thereby suppressing refrigerant from leaking between the compression chambers in advance.

However, in this implementation, the refrigerant suction pipe <NUM> may be inserted through the casing <NUM> and communicate with the suction chamber Vs through the fixed scroll <NUM> in the radial direction. In this case, a separate suction passage opening and closing valve may not be installed between the refrigerant suction pipe and the suction chamber, and in some cases, may alternatively be installed.

Claim 1:
A scroll compressor, comprising:
a casing (<NUM>);
a driving motor (<NUM>) provided in the inner space of the casing (<NUM>);
a rotating shaft (<NUM>) driven by the driving motor (<NUM>);
a fixed scroll (<NUM>) disposed on one side of the driving motor (<NUM>), and provided with a fixed end plate (<NUM>), and a fixed wrap (<NUM>) formed on one side surface of the fixed end plate (<NUM>);
an orbiting scroll (<NUM>) coupled to the rotating shaft (<NUM>) and provided with an orbiting end plate (<NUM>) facing the fixed end plate (<NUM>), and an orbiting wrap (<NUM>) provided on one side surface of the orbiting end plate (<NUM>) and engaged with the fixed wrap (<NUM>) so as to form a first compression chamber (V1) and a second compression chamber (V2); and
a first compression chamber oil supply hole (<NUM>) and a second compression chamber oil supply hole (<NUM>) formed through the orbiting end plate (<NUM>) to communicate with the first compression chamber (V1) and the second compression chamber (V2), respectively,
characterised in that when a crank angle range of the rotating shaft (<NUM>) in which the first compression chamber oil supply hole (<NUM>) is opened toward the first compression chamber (V1) is referred to as a first crank angle range, and another crank angle range of the rotating shaft (<NUM>) in which the second compression chamber oil supply hole (<NUM>) is opened toward the second compression chamber (V2) is referred to as a second crank angle range,
a crank angle range in which the first crank angle range and the second crank angle range does not overlap each other is longer than a crank angle range in which the first crank angle range and the second crank angle range overlap each other.