Patent Description:
A compressor applied to a refrigeration cycle of a refrigerator, an air handling unit, etc. performs a function of compressing and transmitting refrigerant gas to a condenser. A rotary compressor or a scroll compressor is applied to the air handling unit. The scroll compressor is not only applied to the air handling unit, but also recently applied to a water heater that requires a higher compression ratio than the air handling unit.

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

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

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

The scroll compressor includes a fixed scroll including a fixed wrap and an orbiting wrap engaged with the fixed wrap. In the scroll compressor, the orbiting scroll performs an orbiting motion on the fixed scroll.

As the orbiting scroll perform the orbiting motion, the scroll compressor is provided with a first compression chamber between an inner surface of the fixed wrap and an outer surface of the orbiting wrap, and a second compression chamber between an outer surface of the fixed wrap and an inner surface of the orbiting wrap. In the first and second compression chambers, a volume change occurs sequentially according to the orbiting motion of the orbiting scroll to perform suction and compression of refrigerant.

Characteristics of the scroll compressor is determined by shapes of the fixed wrap and the orbiting wrap. The fixed wrap and the orbiting wrap may have any shapes, but generally have a form of an involute curve which is easily machined. Recently, a scroll compressor provided in a form in which a plurality of circular arcs having different diameters and origins are connected to each other so that wrap curves of a fixed wrap and an orbiting wrap have atypical characteristics is introduced.

Patent document <NUM> (Korean Patent Publication NO. <CIT>) discloses a scroll compressor having the atypical wrap curve described above. The scroll compressor is provided such that an eccentric portion of a rotating shaft is coupled to an orbiting scroll on a same plane as that of an orbiting wrap (in an overlapping position on the rotating shaft). This may be generally defined as a through-shaft scroll compressor.

In this through-shaft scroll compressor, a point of action at which repulsive force of refrigerant works and a point of action at which a reaction force against the repulsive force works are located at a same height such that the repulsive force and the reaction force work in opposite directions. Thus, a problem such that the orbiting scroll is inclined may be resolved.

However, with respect to the through-shaft scroll compressor described above, as a rotating shaft is inserted through the fixed scroll, a discharge port is provided in a location eccentric from the fixed scroll. Thus, since compression ratios in compression chambers at both sides become different, an increase portion is provided on the orbiting wrap and a decrease portion corresponding to the increase portion is provided on the fixed wrap. Thus, the compression ratios of the compression chambers at both sides are compensated for to be similar to each other.

However, as the decrease portion is provided near a discharge end of the fixed wrap as described above, the fixed wrap has a small wrap thickness near the discharge end under a comparatively high pressure. Thus, the fixed wrap may not stand pressure in the compression chamber and may be damaged. This may more frequently occur in a compressor that requires a higher compression ratio than that of a compressor applied to an air handling unit, e.g., a compressor for a water heater in which liquid refrigerant or oil excessively flow into a compression chamber.

<CIT> discloses a scroll compressor having an orbiting scroll, a wrap of which is gradually thinned toward its tip end. <CIT> discloses a scroll member for a scroll compressor which includes a modified portion having a base, a step, and a scallop. <CIT> discloses a scroll compressor designed to eliminate the overcompression effect of refrigerant gas at the transition from the final compression stage to the discharge stage. <CIT> discloses a scroll type compressor which is designed to prevent the walls of the scrolls from being damaged by over-compression of gas. <CIT> discloses a scroll wrap which has a stepped clearance surface at an end portion of the wrap to decrease drop of delivery pressure. <CIT> discloses a scroll type compressor, in which the compression gas in a discharge chamber is made to flow into a backside small sealed chamber through a leak passage provided before the position on the revolution angle of the revolving scroll. <CIT> discloses a scroll-type machine suited for use as a gaseous fluid compressor. The machine incorporates symmetrical scroll members of substantially one wrap that have modified inner ends to provide continued sealing to a single separation point. <CIT> discloses an orbiting scroll for a scroll compressor, in which a connection groove having a concave groove shape is provided at an inner surface of the fixed end plate to allow a refrigerant to flow through the connection groove depending on an overlapping state of the fixed wrap and the connection groove.

Therefore, the present disclosure describes a scroll compressor in which a damage to a discharge end of a fixed wrap may be suppressed.

Further, the present disclosure describes a scroll compressor in which a side surface of a fixed wrap and a side surface of an orbiting wrap are slidably in contact with each other, and a volume of a compression chamber between the fixed wrap and the orbiting wrap may be enlarged.

Still further, the present disclosure describes a scroll compressor in which a side surface of a fixed wrap and a side surface of an orbiting wrap are slidably in contact with each other, and a space into refrigerant may temporarily escape may be ensured between the fixed wrap and the orbiting wrap.

The present disclosure also describes a scroll compressor capable of quickly discharging refrigerant from a compression chamber included in a discharge area.

Further, the present disclosure provides a scroll compressor capable of quickly discharging refrigerant by enlarging a substantial discharge area while maintaining a discharge start time.

Still further, the present disclosure describes a scroll compressor capable of ensuring wrap rigidity of a fixed wrap while enlarging a substantial discharge area.

The present invention defined in the appended independent claim achieves these and other advantages identified above. In the following description, there is further provided a scroll compressor including a fixed scroll and a fixed scroll. The orbiting scroll is coupled to a rotating shaft and provided with an orbiting wrap at one side of an orbiting end plate to perform an orbiting motion. The fixed scroll is provided with a fixed wrap on one side surface of a fixed end plate, the fixed wrap being engaged with the orbiting wrap to define a compression chamber. At least one refrigerant accommodating groove recessed to a preset depth from at least one of a side surface of the fixed wrap and a side surface of the orbiting wrap constituting the compression chamber is present. Thus, a volume of the compression chamber in a discharge area is increased in correspondence with a volume of the at least one refrigerant accommodating groove, and a space into which liquid refrigerant, etc. may escape may be ensured to resolve excessive compression in the compression chamber. Then, a stress exerted on the fixed wrap may be reduced, and a damage to the fixed wrap due to pressure in the compression chamber may be suppressed.

As an example, at least one refrigerant accommodating groove may be provided such that an axial length is greater than a radial depth. Thus, a wrap thickness of the fixed wrap or the orbiting wrap may be properly maintained, and a large volume of the refrigerant accommodating groove may be ensured. Thus, a damage to the fixed wrap or the orbiting wrap due to the refrigerant accommodating groove may be suppressed.

As another example, the axial length of the refrigerant accommodating groove may be provided to be equal to or less than a wrap height of the fixed wrap or the orbiting wrap. Thus, deterioration of rigidity of the fixed wrap or the orbiting wrap due to the refrigerant accommodating groove may be suppressed, and thus, a wrap damage due to the refrigerant accommodating groove may be prevented in advance.

In detail, the axial length of the refrigerant accommodating groove may be provided to be greater than half of the wrap height of the fixed wrap or the orbiting wrap and less than the wrap height. Thus, a wrap thickness of the fixed wrap or the orbiting wrap may be properly maintained, and a large volume of the refrigerant accommodating groove may be ensured.

As another example, the refrigerant accommodating groove may be spaced apart from the fixed end plate or the orbiting end plate by a preset height. Thus, rigidity of a wrap root of the fixed wrap or the orbiting wrap may be ensured. Accordingly, the refrigerant accommodating groove may be provided, and meanwhile a wrap damage in the fixed wrap or the orbiting wrap may be suppressed.

As another example, the fixed wrap may include a decrease portion in which a wrap thickness of the fixed wrap decreases, and a projecting portion extending from the decrease portion to constitute an end of the fixed wrap and having an increased wrap thickness compared to the decrease portion. The refrigerant accommodating groove may be provided in an inner surface of the protruding portion. By doing so, the refrigerant accommodating groove is provided in a discharge area and a volume of the compression chamber corresponding to a discharge area may be increased, and a space into which liquid refrigerant, etc. may escape may be ensured to resolve excessive compression in the compression chamber.

In detail, a radial depth of the refrigerant accommodating groove may be provided to be less than half of the wrap thickness in the projecting portion. Thus, a volume of the compression chamber in the discharge area may be enlarged, a space into which liquid refrigerant, etc. may escape may be ensured, and a wrap thickness of the fixed wrap may be ensured due to the refrigerant accommodating groove to suppress a damage to the fixed wrap.

In addition, a minimum distance from an inner surface of the refrigerant accommodating groove to an outer surface of the projecting portion may be equal to or greater than the wrap thickness in the decrease portion Thus, the refrigerant accommodating groove may be provided and rigidity of the fixed wrap may be properly maintained to suppress a damage.

As another example, with respect to the refrigerant accommodating groove, a plurality of refrigerant accommodating grooves may be provided to have a preset space therebetween along a providing direction of the fixed wrap or the orbiting wrap. Thus, a volume of the refrigerant accommodating groove may be ensured at maximum, and a wrap thickness of the fixed wrap or the orbiting wrap may be properly maintained to suppress deterioration of a wrap strength of the refrigerant accommodating grooves.

According to the invention, the fixed end plate is provided with a first and a second discharge port. The refrigerant accommodating groove may be spaced apart from the discharge ports. Thus, the refrigerant accommodating groove is provided, and meanwhile deterioration of a wrap strength of the fixed wrap may be suppressed by maintaining a proper distance between the refrigerant accommodating groove and the discharge port. The refrigerant accommodating groove may be located at a side behind the first port along a compression progressing direction in the compression chamber. Thus, the refrigerant accommodating groove is provided in the compression chamber constituting a substantial discharge area to reduce a shearing stress exerted on the fixed wrap due to a high pressure in the compression chamber. The fixed end plate is provided with a first discharge port configured to discharge refrigerant in the first compression chamber and a second discharge port configured to discharge refrigerant of the second compression chamber. The refrigerant accommodating groove may be provided between the first discharge port and the second discharge port along a providing direction of the fixed wrap. Thus, a volume of the compression chamber corresponding to a substantial discharge area may be increased and an excessive pressure increase in the compression chamber due to uncompressed liquid refrigerant may be effectively resolved. Accordingly, a damage to the fixed wrap may be suppressed.

According to the invention, the compression chamber includes a first compression chamber provided in an inner surface of the fixed wrap and a second provided in an outer surface of the fixed wrap. The fixed end plate is provided with a first discharge port configured to discharge refrigerant in the first compression chamber and a second discharge port configured to discharge refrigerant of the second compression chamber. An auxiliary discharge port is provided between the first discharge port and the second discharge port to be inserted through the fixed end plate. Thus, a discharge area of the compression chamber corresponding to a discharge area may be enlarged to reduce a discharge resistance of compressed liquid. Accordingly, excessive compression may be resolved. Simultaneously, the refrigerant accommodated in the refrigerant accommodating groove may be quickly discharged through the auxiliary discharge port to effectively resolve excessive compression.

The auxiliary discharge port is spaced apart from an inlet of the first discharge port and an inlet of the second discharge port. An outlet of the auxiliary discharge port communicates with an outlet of the first discharge port, or (an outlet of) the second discharge port. Thus, the refrigerant compressed in the compression chamber may be quickly discharged, and the refrigerant accommodated in the refrigerant accommodating groove may quickly flow out.

In addition, with respect to the auxiliary discharge port, a plurality of auxiliary discharge ports may be provided to have a preset space with each other between the first discharge port and the second discharge port along a providing direction of the fixed wrap. Thus, a discharge area of the compression chamber may be ensured and rigidity of a root portion of the fixed wrap may be ensured to provide the auxiliary discharge ports and suppress a damage to the fixed wrap.

Inlets of the plurality of auxiliary discharge ports are spaced apart from the first discharge port and the second discharge port, and outlets of the plurality of auxiliary discharge ports communicate with the first discharge port and/or the second discharge port, and the outlets of the plurality of auxiliary discharge ports may communicate with the first discharge port and the second discharge port in equal numbers, respectively. Thus, discharge areas of compression chambers at both sides may be evenly enlarged, and refrigerant compressed in the compression chambers at both sides may be evenly distributed in the auxiliary discharge ports, and thus, discharged quickly.

In addition, the refrigerant accommodating groove may be spaced apart from the auxiliary discharge port. By doing so, as the refrigerant accommodating groove and the auxiliary discharge ports are separated from each other, the refrigerant accommodating groove and the auxiliary discharge ports are provided together and a wrap strength of the fixed wrap may be ensured.

As still another example, the orbiting wrap may be provided with a discharge guide groove connecting an outer surface constituting the compression chamber to an end surface of the orbiting wrap, the end surface facing the fixed end plate. The refrigerant accommodating groove may communicate with at least a part of the refrigerant accommodating groove in a discharge section of the compression chamber. Accordingly, a substantial discharge area in the compression chamber may be enlarged due to the refrigerant accommodating groove, and the refrigerant accommodated in the refrigerant accommodating groove may quickly flow out.

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

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

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

Hereinafter, a hermetic scroll compressor in which a driving unit (or a motor part or a driving motor) and a compression unit are included in a casing is described as an example of the scroll compressor. However, an open-type compressor in which a driving unit (a motor part or a driving motor) is included outside the casing and connected to a compression unit in the casing may be also adopted as the scroll compressor.

In addition, hereinafter, a compressor which is a vertical-type scroll compressor, in which a motor part and a compression unit are arranged in a longitudinal axial direction, and also a bottom compression type scroll compressor, in which a compression unit is located below a driving unit (or a motor part or a driving motor), is described as an example. However, the description may be also applied to not only a horizontal type scroll compressor in which a driving unit (a motor part or a driving motor) and a compression unit are arranged in a left-right direction, but also a top compression type scroll compressor in which a compression unit is arranged above a driving unit (a motor part or a driving motor) are arranged.

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

<FIG> is a longitudinal sectional view illustrating an inner structure of a scroll compressor in accordance with this implementation.

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

The driving motor <NUM> constituting the motor part is coupled to an upper end of a rotating shaft <NUM> to be described later, and the compression part C is coupled to a lower end of the rotating shaft <NUM>. Accordingly, the compressor <NUM> constitutes the bottom-compression type structure described above, and the compression part C is connected to the driving motor <NUM> by the rotating shaft <NUM> to operate according to rotational force of the driving motor <NUM>. Thus, the driving motor <NUM> may be understood as a driving unit configured to drive the compression unit C. Hereinafter, in the description, a driving motor may be also referred as a motor part or a driving 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 open upper end of the cylindrical shell <NUM>. The lower shell <NUM> may be coupled to cover the open lower end of the cylindrical shell <NUM>. Accordingly, the inner space 110a of the casing <NUM> may be sealed. The sealed inner space 110a of the casing <NUM> may be divided into a lower space S1 and an upper space S2 based on the driving motor <NUM>.

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

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

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

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

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

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 a condenser <NUM>, or a check valve (not shown) for suppressing refrigerant discharged from the compressor <NUM> from flowing back into the compressor <NUM>.

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

Referring to <FIG>, the driving motor <NUM> according to the implementation may include a stator <NUM> and a rotor <NUM>. The stator <NUM> may be fixed into 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 an annular shape or a hollow cylindrical shape and may be shrink-fitted onto the inner circumferential surface of the cylindrical shell <NUM>.

The stator coil <NUM> may be wound around the stator core <NUM> and may be electrically connected to an external power source through a power cable <NUM> that is coupled through the casing <NUM>. An insulator (no reference numeral), which is an insulating member, may be inserted between the stator core <NUM> and the stator coil <NUM>.

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

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

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

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

The rotating shaft <NUM> may be coupled to the center of the stator core <NUM>. An upper end portion of the rotating shaft <NUM> may be press-fitted to the rotor <NUM>, and a lower end portion of the rotating shaft <NUM> 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, a portion, which is inserted into the main frame <NUM>, of the lower end portion of the rotating shaft <NUM> may smoothly rotate inside the main frame <NUM>.

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

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

Referring to <FIG>, the compression unit C according to this implementation includes the main frame <NUM>, the fixed scroll <NUM>, and the orbiting scroll <NUM>.

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

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

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

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

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

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

The fixed wrap <NUM> is provided to 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 a compression chamber V. The compression chamber V includes the first compression chamber V1 defined between an inner surface of the fixed wrap <NUM> and an outer surface of the orbiting wrap <NUM>, and the second compression chamber V2 defined between an outer surface of the fixed wrap <NUM> and an inner surface of the orbiting wrap <NUM>.

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

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

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

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

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

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

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

However, since the outer surface of the rotating shaft coupling portion <NUM> and the inner surface of the fixed wrap <NUM> define the first pressure chamber V1 as described above, it may be understood that the rotating shaft coupling portion <NUM> constitutes a part of the orbiting wrap <NUM>. Thus, the rotating shaft coupling portion <NUM> may be referred to as the orbiting wrap <NUM> as needed. For example, a discharge guide groove <NUM>, a second refrigerant accommodating groove <NUM>, etc. to be described later are substantially provided in an end surface of the rotating shaft coupling portion <NUM>. However, hereinafter, the discharge guide groove <NUM> and the second refrigerant accommodating groove <NUM> are described as being provided in an end surface of the orbiting wrap <NUM> at an innermost side.

In the drawing, unexplained reference numerals, i.e., <NUM> denotes a bypass hole, and <NUM> denotes an Oldham ring.

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

That is, when power is applied to the motor part <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 relative to the fixed scroll <NUM> by the Oldham ring <NUM>.

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

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

The refrigerant flows out into the outflow passage S12 between the main frame <NUM> and the driving motor <NUM> through outflow holes (no reference numeral) in the fixed scroll <NUM> and the main frame <NUM>. Then, the refrigerant passes through the driving motor <NUM> to move to the upper space S2 of the casing <NUM> defined above the driving motor <NUM>. The refrigerant is separated into refrigerant and oil in the upper space S2. The refrigerant, i.e., a result of the separation flows out of the casing <NUM> through the refrigerant discharge pipe <NUM>, whereas the oil obtained by being separated from the refrigerant is returned to the oil storage space S11 of the casing <NUM> through the oil return passage (no reference numeral) described above. The oil is supplied to a bearing surface (no reference numeral) and the compression chamber V through the oil supply passage <NUM>, and then returned. This series of processes may be repeatedly performed.

In a through-shaft scroll compressor as described above, as the rotating shaft <NUM> is inserted through the center of the fixed scroll <NUM>, the first and second discharge holes <NUM> and <NUM> are arranged in a position eccentric from the center of the fixed scroll <NUM>. Thus, as a compression cycle of the first pressure chamber V1 in an inner portion of the fixed wrap <NUM> is shorter than that of the second compression chamber V2 on an outer portion of the fixed wrap <NUM>, a compression ratio in the first pressure chamber V1 may be reduced.

Thus, an increase portion <NUM> in which a wrap curve is expanded may be provided on an outer circumferential surface of the orbiting wrap <NUM> at an innermost portion, i.e., an outer circumferential surface of the rotating shaft coupling portion <NUM> to extend a compression cycle of the first compression chamber V1. However, since a decrease portion <NUM> is provided near a discharge end of the fixed wrap <NUM> corresponding to the increase portion <NUM> of the orbiting <NUM> to correspond to the increase portion <NUM>, a wrap thickness of the fixed wrap <NUM> is small near the discharge end under a comparatively high pressure. Thus, the fixed wrap <NUM> may not stand pressure in the compression chamber V and may be damaged. This may frequently occur particularly when liquid refrigerant or oil excessively flows into the compression chamber V.

In consideration of this, areas of the first and second discharge ports <NUM> and <NUM> may be enlarged. However, when the areas of the first and second discharge ports <NUM> and <NUM> are enlarged, a discharge start time of each of the first and second compression chambers V1 and V2 is advanced, thereby deteriorating a compression ratio. Accordingly, there is a limitation in ensuring a proper compression ratio by enlarging sizes of the first and second compression chambers V1 and V2.

In relation to this, in this implementation, excessive compression may be suppressed by expanding a volume of a compression chamber constituting discharge pressure. By doing so, compression efficiency may be increased, and even when refrigerant that was not compressed together with liquid refrigerant is introduced, a damage to the fixed wrap <NUM> may be suppressed, and thus, reliability may be increased.

<FIG> is a detached perspective view of the fixed scroll and the orbiting scroll both shown in <FIG>. <FIG> is an enlarged perspective view of a main portion of the fixed scroll of <FIG>. <FIG> is a cross-sectional view illustrating a state in which the fixed scroll is coupled to the orbiting scroll, both shown in <FIG>. <FIG> is a cross-sectional view taken along line "IX-IX" of <FIG>.

Referring to <FIG>, the fixed scroll <NUM> and the orbiting scroll <NUM> according to this implementation are engaged with each other to define the first and second compression chambers V1 and V2. Areas of the first and second compression chambers V1 and V2 gradually decrease in a direction from an edge constituting a suction portion toward a center portion constituting a discharge portion. Accordingly, the first and second compression chambers V1 and V2 are provided such that pressure in a central portion is higher than that in an edge portion.

However, as the rotating shaft <NUM> is inserted and coupled through a central portion of the fixed scroll <NUM> and the orbiting scroll <NUM>, the first discharge port <NUM> and the second discharge port <NUM> are arranged in positions eccentric from the center of the fixed scroll <NUM> as described above. Accordingly, as described above, a compression cycle of the first compression chamber V1 may be extended by providing the increase portion <NUM> on an outer circumferential surface of the orbiting wrap <NUM> at an innermost portion (hereinafter referred to as an orbiting wrap). By doing so, a compression ratio of the first compression chamber V1 may be corrected to be similar to that of the second compression chamber V2.

In detail, referring to <FIG>, the orbiting scroll <NUM> includes the orbiting wrap <NUM> provided on one side surface of the orbiting end plate <NUM> and the rotating shaft coupling portion <NUM> inserted through a center of the orbiting scroll <NUM>. Like the fixed wrap <NUM>, the orbiting wrap <NUM> may be provided such that a plurality of circular arcs having different diameters and origins are connected to each other so that wrap curves have atypical characteristics. Accordingly, the orbiting wrap <NUM> may be provided to have different wrap thicknesses according to a wrap progressing direction.

For example, the orbiting wrap <NUM> includes the increase portion <NUM> having a gradually increasing wrap thickness, at an end of a discharge portion (accurately, an outer circumferential surface of the rotating shaft coupling portion <NUM>), and a concave portion <NUM> having a decreasing wrap thickness to extend from the increase portion <NUM> toward the discharge portion and connect to a circular arc portion <NUM>. The increase portion <NUM> corresponds to the decrease portion <NUM> of the fixed wrap <NUM> to be described later, and the concave portion <NUM> corresponds to a projecting portion <NUM> of the fixed wrap <NUM> to be described later.

Referring to <FIG>, the fixed scroll <NUM> according to this implementation includes the fixed side wall <NUM> at an edge of the fixed end plate <NUM>, the sub bearing unit <NUM> in a center portion of the fixed end plate <NUM>, and the first discharge port <NUM> and the second discharge port <NUM> near the sub bearing unit <NUM> to have a preset space with each other. The first discharge port <NUM> communicates with the first compression chamber V1, and the second discharge port <NUM> communicates with the second compression chamber V2. Accordingly, refrigerant compressed while moving along the first compression chamber V1 is discharged into the muffler space 160a of the discharge cover <NUM> through the first discharge port <NUM>, and refrigerant compressed while moving along the second compression chamber V2 is discharged into the muffler space 160a of the discharge cover <NUM> through the second discharge port <NUM>.

The fixed wrap <NUM> constituting the first and second compression chamber V1 and V2 described above are provided in the fixed side wall <NUM>. The fixed wrap <NUM> may be provided such that a plurality of circular arcs having different diameters and origins are connected to each other so that wrap curves have atypical characteristics. Accordingly, the fixed wrap <NUM> may be provided to have different wrap thicknesses according to a wrap progressing direction.

For example, the fixed wrap <NUM> includes the decrease portion <NUM> at an end of a discharge portion to correspond to the increase portion <NUM> of the orbiting <NUM> as described above, and the projecting portion <NUM> protruding from the decrease portion <NUM> to correspond to the concave portion <NUM> of the orbiting wrap <NUM> described above.

In other words, the fixed wrap <NUM> includes the decrease portion <NUM> having a wrap thickness gradually decreasing toward a discharge end to correspond to the increase portion <NUM> of the orbiting wrap <NUM>, and the projecting portion <NUM> extending toward a discharge portion of the decrease portion <NUM> and having an increasing wrap thickness to correspond to the concave portion <NUM> of the orbiting wrap <NUM>. The projecting portion <NUM> provides the discharge end of the fixed wrap <NUM>. Thus, a discharge chamber, i.e., a final compression chamber is provided in a periphery of the decrease portion <NUM> including the projecting portion <NUM> and a periphery of the increase portion <NUM> including the concave portion <NUM> of the orbiting wrap <NUM> facing the periphery of the decrease portion <NUM>.

Referring to <FIG>, the refrigerant accommodating groove <NUM> is provided in a side surface of the fixed wrap <NUM> according to this implementation. The refrigerant accommodating groove <NUM> is provided in an inner surface 144a of the fixed wrap <NUM> to be radially recessed to a preset depth. By doing so, as a volume of the first compression chamber V1, more accurately, a volume of the first compression chamber V1 in a discharge portion increases, excessive compression may be resolved. In other words, as refrigerant compressed in the first compression chamber V1 (e.g., liquid refrigerant) temporarily escapes into the refrigerant accommodating groove <NUM>, an excessive pressure increases in the first compression chamber V1 may be avoided, and thus, a damage to a discharge end portion of the fixed wrap <NUM> may be suppressed.

For example, the refrigerant accommodating groove <NUM> may be provided in an inner surface of the fixed wrap <NUM> constituting a compression chamber (a discharge chamber) provided at a time when the first and second discharge ports <NUM> and <NUM> start discharging. In other words, the refrigerant accommodating groove <NUM> may be provided in the inner surface of the fixed wrap <NUM> facing the first discharge port <NUM> and the second discharge port <NUM> to, when being axially projected, be located between the first discharge port <NUM> and the second discharge port <NUM>. Accordingly, the refrigerant accommodating groove <NUM> is located at a side behind the first discharge port <NUM> and/or the second discharge port <NUM> with reference to a compression path of the refrigerant. Then, the refrigerant compressed in the compression chamber V may be prevented from remaining in the compression chamber V after passing through the first discharge port <NUM> and/or the second discharge port <NUM>.

In addition, as the refrigerant accommodating groove <NUM>, when being axially projected, is located between the first and second discharge ports <NUM> and <NUM>, i.e., in the compression chamber V corresponding to a discharge portion, a volume of the compression chamber V constituting the discharge portion (e.g., the first compression chamber V1) increases in correspondence with a volume of the refrigerant accommodating groove <NUM>. Thus, excessive compression may be resolved. In addition, as a free space into which liquid refrigerant may escape is provided in the compression chamber V constituting the discharge portion in correspondence with the volume of the refrigerant accommodating groove <NUM> (e.g., the first compression chamber V1), stress on the fixed wrap <NUM> may be resolved.

In detail, the refrigerant accommodating groove <NUM> may be provided in an inner surface 1442a of the projecting portion <NUM>. In other words, the refrigerant accommodating groove <NUM> may be provided in the inner surface 1442a of the projecting portion <NUM> located between the first discharge port <NUM> and the second discharge port <NUM>. By doing so, a volume of a compression chamber (a discharge chamber) in a section in which a compression load on the fixed wrap <NUM> is greatest may increase. Thus, as described above, excessive compression may be resolved, and simultaneously, a damage to the fixed wrap <NUM> due to the excessive compression may be suppressed.

Referring to <FIG>, the refrigerant accommodating groove <NUM> is recessed from the inner surface 1442a to an outer surface 1442b of the projecting portion <NUM>. A recessed depth D1 of the refrigerant accommodating groove <NUM> may be provided to be less than half of a wrap thickness T (an average wrap thickness) of the projecting portion <NUM>. For example, the recessed depth D1 of the refrigerant accommodating groove <NUM> may be provided such that a minimum wrap thickness T1' of the projecting portion <NUM> is equal to or greater than a wrap thickness T2 of the decrease portion <NUM>, the minimum wrap thickness T1' of the projecting portion <NUM> being defined as a minimum distance from the inner surface 1444a of the refrigerant accommodating groove <NUM> to the outer surface 1442b of the projecting portion <NUM>. By doing so, an excessive decrease in the minimum wrap thickness T1' of the projecting portion <NUM> of the refrigerant accommodating groove <NUM> may be suppressed. Thus, the projecting portion <NUM> may be prevented from being damaged due to the refrigerant accommodating groove <NUM>.

The refrigerant accommodating groove <NUM> is provided to have a shape of a semicircular cross-section when being axially projected, but is not limited thereto. In other words, the refrigerant accommodating groove <NUM> may be provided to have a shape of an angular cross-section.

The refrigerant accommodating groove <NUM> is provided to have a same cross-sectional area in an axial direction, but is not limited thereto. In other words, the refrigerant accommodating groove <NUM> may be provided to have different cross-sectional areas along an axial direction. For example, the refrigerant accommodating groove <NUM> may be provided to have a large cross-sectional area when being adjacent to the first discharge port <NUM>. Accordingly, refrigerant accommodated in the refrigerant accommodating groove <NUM> may be guided to the first and second discharge ports <NUM> and <NUM>.

The refrigerant accommodating groove <NUM> is provided to have an axial length H2 greater than a radial depth. For example, the refrigerant accommodating groove <NUM> is provided in an axial direction, and the axial length H2 of the refrigerant accommodating groove <NUM> may be greater than the radial depth (accurately, a transverse depth) thereof. Accordingly, a volume of the refrigerant accommodating groove <NUM> compared to the radial depth thereof may be ensured at maximum.

Although not illustrated in the drawing, the refrigerant accommodating groove <NUM> may be provided to be inclined or curved. Accordingly, when the refrigerant accommodating groove <NUM> has a constant radial depth, a large volume may be ensured. This may be more effective when one refrigerant accommodating groove <NUM> is provided.

Referring to <FIG>, the axial length H2 of the refrigerant accommodating groove <NUM> may be provided to be equal to or less than an axial height H1 of the fixed wrap <NUM>. For example, the axial length H2 of the refrigerant accommodating groove <NUM> may be provided to be less than the axial height H1 of the fixed wrap <NUM>. In detail, the refrigerant accommodating groove <NUM> may be provided from an end surface of the fixed wrap <NUM> toward the fixed end plate <NUM> along an axial direction, and an end of the refrigerant accommodating groove <NUM> toward the fixed end plate <NUM>, i.e., a second end may be provided not to overlap a built-up surface <NUM> connected between the fixed wrap <NUM> and the fixed end plate <NUM> by a curve surface (or an inclined surface). In other words, the end toward the fixed end plate <NUM>, i.e., a lower end of the refrigerant accommodating groove <NUM> may be provided at a height same as or greater than that of the built-up surface <NUM>. Accordingly, a large volume of the refrigerant accommodating groove <NUM> may be ensured, and rigidity of a lower end (a root portion) of the fixed wrap <NUM> may be ensured.

By doing so, occurrence of a compression loss may be suppressed by suppressing excessive compression in a discharge pressure section constituting a high-pressure region during operation of a compressor. In addition, a damage to the fixed wrap <NUM> due to the excessive compression in the discharge pressure section may be suppressed.

In addition, the refrigerant accommodating groove <NUM> may be provided in the inner surface of the fixed wrap <NUM>, and the refrigerant accommodating groove <NUM> is provided such that an end of a root portion of the fixed wrap <NUM> is provided slightly apart from the fixed end plate <NUM>. Thus, deterioration of rigidity of the fixed wrap <NUM> due to the refrigerant accommodating groove <NUM> may be suppressed.

Hereinafter, a description will be given of another implementation of a refrigerant accommodating groove.

That is, in the implementations described above, one refrigerant accommodating groove is provided. However, in some cases, a plurality of refrigerant accommodating grooves may be provided.

<FIG> is an enlarged perspective view of another implementation of the fixed scroll <NUM> of <FIG>.

Referring to <FIG>, the fixed scroll <NUM> according to this implementation includes the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM>. A basic configuration and an effect of the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM> are almost identical to those in the implementation described above. Thus, a description thereof will not be provided here.

In other words, in this implementation, an inner surface of the fixed wrap <NUM>, i.e., the inner surface 1442a of the projecting portion <NUM> is provided with the refrigerant accommodating groove <NUM> like the implementation described above. In this case, a position, a shape, and an axial length of the refrigerant accommodating groove <NUM> may be provided to be almost identical to those in the implementation described above.

However, in this implementation, a plurality of refrigerant accommodating grooves <NUM> may be provided to have a preset space therebetween along a wrap providing direction of the fixed wrap <NUM>. For example, the plurality of refrigerant accommodating grooves <NUM> may be provided between the first discharge port <NUM> and the second discharge port <NUM> like the implementation described above, and provided to have a preset space therebetween along a wrap providing direction of the fixed wrap <NUM>.

In detail, a radial depth (or a recessed depth) D1 of each of the refrigerant accommodating grooves <NUM> may be provided to have a same or smaller size compared to that of the refrigerant accommodating groove <NUM> in the implementation described above.

For example, when the radial depth D1 (or the recessed depth) of each of the refrigerant accommodating grooves <NUM> is provided to be identical to that of the refrigerant accommodating groove <NUM> in the implementation described above, a whole volume of the refrigerant accommodating grooves <NUM> may increase correspondingly. Thus, excessive pressure in a high-pressure area constituting a discharge chamber section may be effectively resolved.

In addition, when the radial depth D1 (or the recessed depth) of each of the refrigerant accommodating groove <NUM> is provided to be smaller than that of refrigerant accommodating groove <NUM> in the implementation described above, a large cross-sectional area of the fixed wrap <NUM> (a projecting portion) other than the refrigerant accommodating grooves <NUM> is ensured. Accordingly, the plurality of refrigerant accommodating grooves <NUM> may be provided in the fixed wrap <NUM>, and meanwhile, wrap rigidity in the high-pressure area constituting the discharge chamber section may be ensured.

Although not illustrated in the drawing, when the plurality of refrigerant accommodating grooves <NUM> are provided, specifications of the respective refrigerant accommodating grooves <NUM>, e.g., radial depths or axial lengths thereof may be provided variously. For example, the refrigerant accommodating grooves <NUM> may have a radial depth or axial length gradually decreasing toward a discharge end. Accordingly, the plurality of refrigerant accommodating grooves <NUM> may be provided in the fixed wrap <NUM>, and meanwhile, rigidity of the fixed wrap <NUM> may be also ensured.

Hereinafter, a description will be given of still another implementation of a refrigerant accommodating groove.

That is, in the implementations described above, a refrigerant accommodating groove is provided only in a fixed wrap. However, in some cases, a refrigerant accommodating groove may be also provided in an orbiting wrap.

<FIG> is an enlarged perspective view of another implementation of a fixed scroll and an orbiting scroll. <FIG> is a cross-sectional view illustrating a state in which the fixed scroll is coupled to the orbiting scroll, both shown in <FIG>.

Referring to <FIG> and <FIG>, the fixed scroll <NUM> according to this implementation includes the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM>. A basic configuration and an effect of the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM> are almost identical to those in the implementation described above. Thus, a description thereof will not be provided here again.

In other words, in this implementation, an inner surface of the fixed wrap <NUM>, i.e., the inner surface 1442a of the projecting portion <NUM> is provided with the refrigerant accommodating groove <NUM> (hereinafter a first refrigerant accommodating groove) like the implementation described above. In this case, a position, a shape, and an axial length and an effect of the refrigerant accommodating groove <NUM> are same as those of the refrigerant accommodating groove <NUM> in the implementation described above. Thus, a description thereof will not be provided here again.

In addition, the orbiting scroll <NUM> includes the orbiting end plate <NUM>, the orbiting wrap <NUM>, and the rotating shaft coupling portion <NUM>. A basic configuration and an effect of the orbiting end plate <NUM>, the orbiting wrap <NUM>, and the rotating shaft coupling portion <NUM> are almost identical to those in the implementation described above. Thus, a description thereof will not be provided here again.

In other words, in this implementation, as the rotating shaft coupling portion <NUM> is inserted through a center of the orbiting end plate <NUM>, the increase portion <NUM> and the concave portion <NUM> are sequentially provided on an outer circumferential surface of the rotating shaft coupling portion <NUM> constituting a part of the orbiting wrap <NUM>, the increase portion <NUM> corresponding to the decrease portion <NUM> of the fixed wrap <NUM> and the concave portion <NUM> corresponding to the projecting portion <NUM> of the fixed wrap <NUM>. An effect obtained therefrom is identical to that in the implementations described above. Thus, a description thereof will not be provided here.

However, in this implementation, the second refrigerant accommodating groove <NUM> is provided on an outer circumferential surface of the rotating shaft coupling portion <NUM>, i.e., an outer surface of the orbiting wrap <NUM> facing an inner surface of the fixed wrap <NUM>. For example, the second refrigerant accommodating groove <NUM> may be included in a compression chamber including the first refrigerant accommodating groove <NUM>, in a section in which the compression chamber including the first refrigerant accommodating groove <NUM> performs discharge strokes. In other words, in the same compression chamber, the first refrigerant accommodating groove <NUM> may be provided in the fixed wrap <NUM>, and the second refrigerant accommodating groove <NUM> may be provided in the orbiting wrap <NUM>. Accordingly, a compression chamber volume in a discharge chamber section corresponding to a high-pressure area may increase compared to the implementations described above. Thus, excessive compression in a compression chamber included in a discharge area may be suppressed to prevent a damage to the fixed wrap <NUM>.

In addition, the second refrigerant accommodating groove <NUM> may be provided to be identical to the first refrigerant accommodating groove <NUM> in the implementations described above. For example, the second refrigerant accommodating groove <NUM> may be provided to have a long groove shape such that an axial length (no reference numeral) is greater than a radial depth (no reference numeral), and greater than half of an axial length of the orbiting wrap <NUM> and less than the axial length of the orbiting wrap <NUM>. In other words, the second refrigerant accommodating groove <NUM> may be provided such that an end toward the orbiting end plate is located at a height equal to or less than that of the built-up surface <NUM> connecting between the orbiting wrap <NUM> and the orbiting end plate <NUM> using a curved surface. Accordingly, the second refrigerant accommodating groove <NUM> may be provided in the orbiting wrap <NUM>, and rigidity of the orbiting wrap <NUM> may be ensured.

In addition, like <FIG> and <FIG>, the discharge guide groove <NUM> may be further provided in an end surface of the rotating shaft coupling portion <NUM>. In other words, an inlet 1524a of the discharge guide groove <NUM> may be recessively provided at an outer edge of the orbiting wrap <NUM> at an innermost side constituting an outer edge of the rotating shaft coupling portion <NUM>. In addition, an outlet 1524b of the discharge guide groove <NUM> may be recessively provided in an end surface of the orbiting wrap <NUM> at an innermost side (the rotating shaft coupling portion) to extend from the outer edge of the orbiting wrap <NUM> at the innermost side along a circumferential direction.

In this case, the second refrigerant accommodating groove <NUM> is provided to communicate with the discharge guide groove <NUM>. In other words, an end of the second refrigerant accommodating groove <NUM> orienting toward the end surface of the second refrigerant accommodating groove <NUM> at the innermost side may be provided to communicate with the inlet 1524a of the discharge guide groove <NUM>. Accordingly, after refrigerant accommodated in the second refrigerant accommodating groove <NUM> is quickly guided to the discharge guide groove <NUM>, the refrigerant flows out into the first discharge port <NUM> and/or the second discharge port <NUM>. Thus, as refrigerant (liquid refrigerant) in a compression chamber quickly flows out, remaining of the refrigerant in the compression chamber may be minimized to suppress excessive compression.

Although not illustrated in the drawing, the second refrigerant accommodating groove <NUM> is provided only in the orbiting wrap <NUM>, and the first refrigerant accommodating groove <NUM> (or the refrigerant accommodating groove) described above may not be provided in the fixed wrap <NUM>. In this case, a configuration and an effect of the second refrigerant accommodating groove <NUM> provided in the orbiting wrap <NUM> are identical to those of the second refrigerant accommodating groove <NUM> described above. Thus, a description thereof will not be provided here.

Hereinafter, a description will be given of a fixed scroll according to the claimed invention.

That is, in the implementation described above, a refrigerant accommodating groove is provided in an inner surface of a fixed wrap. However, according to the invention, an auxiliary discharge port is further provided in a fixed end plate.

<FIG> is an enlarged perspective view of the fixed scroll of <FIG> according to the claimed invention. <FIG> is a cross-sectional view taken along line "X-X" of <FIG>. <FIG> is an enlarged perspective view of still another implementation of the fixed scroll of <FIG>, not falling in the scope of independent claim <NUM>.

Referring to <FIG> and <FIG>, the fixed scroll <NUM> includes the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM>. A basic configuration and an effect of the fixed end plate <NUM>, the fixed side wall <NUM>, the sub bearing portion <NUM>, and the fixed wrap <NUM> are almost identical to those in the implementation described above. Thus, a description thereof will not be provided here.

In other words, an inner surface of the fixed wrap <NUM> i.e., the inner surface 1442a of the projecting portion <NUM> is provided with the refrigerant accommodating groove <NUM> like the implementation described above. In this case, a position, a shape, and an axial length of the refrigerant accommodating groove <NUM> may be provided to be almost identical to those in the implementation described above.

However, the fixed end plate <NUM> according to the claimed invention is provided with the first discharge port <NUM> communicating with the first compression chamber V1 and the second discharge port <NUM> communicating with the second compression chamber V2. The auxiliary discharge port <NUM> may be arranged between the first discharge port <NUM> and the second discharge port <NUM>. Accordingly, the auxiliary discharge port <NUM> is located adjacent to the refrigerant accommodating groove <NUM> compared to the first discharge port <NUM> and/or the second discharge port <NUM>. Thus, refrigerant (liquid refrigerant) that escaped into the refrigerant accommodating groove <NUM> during discharge strokes may quickly flow out through the auxiliary discharge port <NUM> adjacent thereto. Also, as a discharge area (accurately, a discharge port inlet area) in a discharge pressure section constituting a high-pressure area is enlarged, excessive compression due to discharge resistance may be resolved.

In addition, as illustrated in <FIG>, the auxiliary discharge port <NUM> communicates with the first discharge port <NUM> and/or the second discharge port <NUM>. For example, the first discharge port <NUM> and/or the second discharge port <NUM> are provided to have a multi-stage shape in which outlets 1411b and 1412b are wider than inlets 1411b and 1412b. Thus, the inlet 1414a of the auxiliary discharge port <NUM> is spaced apart from the inlets 1411a and/or 1412a of the first discharge port <NUM> and/or the second discharge port <NUM>, but the outlet 1414b of the auxiliary discharge port <NUM> communicates with each of the outlets 1411b and/or 1412b of the first discharge port <NUM> and/or the second discharge port <NUM>. Accordingly, refrigerant discharged through the auxiliary discharge port <NUM> may quickly flow out into the muffler space 160a of the discharge cover <NUM> through the first discharge port <NUM> and/or the second discharge port <NUM>.

In addition, at least one auxiliary discharge port <NUM> may be provided between the first discharge port <NUM> and the second discharge port <NUM>, and a plurality of auxiliary discharge ports <NUM> may be provided as possible. Accordingly, a discharge area of a compression chamber may be enlarged.

In addition, the at least one auxiliary discharge port <NUM> may be provided to have a smaller cross-sectional area than that of the first discharge port <NUM> and/or the second discharge port <NUM>, and the plurality of auxiliary discharge ports <NUM> may be provided to have a preset space therebetween. In other words, one auxiliary discharge port <NUM> may be provided to be elongated. However, as illustrated in <FIG>, the auxiliary discharge port <NUM> may be divided into a plurality of auxiliary discharge ports to have a preset space therebetween. Like this implementation, when the plurality of auxiliary discharge ports <NUM> are provided, rigidity of the fixed wrap <NUM> may be ensured compared to when one auxiliary discharge port <NUM> is provided to be elongated.

For example, the auxiliary discharge ports <NUM> may be provided to have a same space with each other between the first discharge port <NUM> and the second discharge port <NUM>, and the auxiliary discharge ports <NUM> may be provided to communicate with the first discharge port <NUM> and the second discharge port <NUM> in equal numbers or with a same cross-sectional area, respectively. In other words, among the auxiliary discharge ports <NUM>, an auxiliary discharge port A adjacent to the first discharge port <NUM> may communicate with the first discharge port <NUM>, and an auxiliary discharge port B adjacent to the second discharge port <NUM> may communicate with the second discharge port <NUM>. By doing so, discharge resistance in the first discharge port <NUM> and the second discharge port <NUM> may not be eccentrically but evenly distributed. Thus, the auxiliary discharge ports <NUM> may be provided between the first discharge port <NUM> and the second discharge port <NUM>, and a delay in refrigerant discharge may be minimized.

In addition, the plurality of auxiliary discharge ports <NUM> may be provided to be spaced apart from the refrigerant accommodating groove <NUM>. In other words, as an end (a second end) of the refrigerant accommodating groove <NUM> toward a wrap root thereof is provided at a height same as or greater than that of an end of a wrap portion of the built-up surface <NUM>, the auxiliary discharge ports <NUM> may be spaced apart from the second end of the refrigerant accommodating groove <NUM>. Accordingly, the auxiliary discharge ports <NUM> may be inserted through the fixed end plate <NUM>, and meanwhile, rigidity of a root end of the fixed wrap <NUM> may be ensured.

As described above, since the auxiliary discharge ports <NUM> are provided in the fixed end plate <NUM>, refrigerant (liquid refrigerant) that escaped into the refrigerant accommodating groove <NUM> in an inner surface of the fixed wrap <NUM> may quickly flow out through the auxiliary discharge ports <NUM> located nearer than the first discharge port <NUM> and/or the second discharge port <NUM>. By doing so, accumulation of non-discharged refrigerant in a discharge chamber section, i.e., a high-pressure area may be reduced to effectively resolve excessive compression. Particularly, when liquid refrigerant is accommodated in the refrigerant accommodating groove <NUM>, as the liquid refrigerant quickly flows out through the auxiliary discharge ports <NUM>. the excessive compression described above may be more effectively resolved.

In addition, as the fixed end plate <NUM> is further provided with the auxiliary discharge ports <NUM> in addition to the first discharge port <NUM> and the second discharge port <NUM>, an inlet area for discharge may be enlarged. Thus, as refrigerant in the discharge section. i.e., a high-pressure area is smoothly discharged, excessive pressure due to discharge resistance may be effectively resolved.

One auxiliary discharge port <NUM> may be provided to a long groove shape.

In addition, as illustrated in <FIG>, not falling within the scope of independent claim <NUM>, the auxiliary discharge port <NUM> may be provided to communicate between the first discharge port <NUM> and the second discharge port <NUM>. This case may be similar to a case when the inlet 1411a of the first discharge port <NUM> and the inlet 1412a of the second discharge port <NUM> may be connected to each other to substantially provide one discharge port. Accordingly, as discharge start times in the first and second compression chambers V1 and V2 match with each other, excessive compression due to a discharge delay may be resolved.

As described above, even when one auxiliary discharge port <NUM> is provided to have a long groove shape, the refrigerant accommodating groove <NUM> may be, when being radially projected, provided in a position radially overlapping the auxiliary discharge port <NUM>. Accordingly, refrigerant accommodated in the refrigerant accommodating groove <NUM> may quickly move to the auxiliary discharge port <NUM> and be discharged through the first discharge port <NUM> and/or the second discharge port <NUM>.

Although not illustrated in the drawing, the fixed end plate <NUM> is provided with the auxiliary discharge port <NUM> according to the implementations of <FIG> and <FIG> described above, the fixed wrap <NUM> may be provided with the first refrigerant accommodating groove <NUM> described above, and the orbiting wrap <NUM> may be provided with the second refrigerant accommodating groove <NUM>. In this case, the auxiliary discharge port <NUM> and the first refrigerant accommodating groove <NUM> may be provided to be identical to those in the implementations of <FIG> and <FIG> described above, and the second refrigerant accommodating groove <NUM> may be provided to be identical to that in the implementation of <FIG>. An effect to be obtained therefrom may be similar to that in the implementation described above. However, in this implementation, as the second refrigerant accommodating groove <NUM> is provided in the orbiting wrap <NUM>, a discharge area of a compression chamber is enlarged like the implementation of <FIG>. Thus, an area into which refrigerant (liquid refrigerant) may escape from the compression chamber may be enlarged, and excessive compression in the compression chamber may be effectively suppressed.

Claim 1:
A scroll compressor comprising:
a casing (<NUM>);
a driving motor (<NUM>) comprising a stator (<NUM>) fixed to an inner surface of the casing (<NUM>), and a rotor (<NUM>) rotatably disposed in the stator (<NUM>);
a rotating shaft (<NUM>) coupled to and being rotatable with the rotor (<NUM>);
an orbiting scroll (<NUM>) coupled to the rotating shaft (<NUM>) and provided with an orbiting wrap (<NUM>) at one side of an orbiting end plate (<NUM>) to perform an orbiting motion;
a fixed scroll (<NUM>) provided with a fixed wrap (<NUM>) on one side surface of a fixed end plate (<NUM>), the fixed wrap (<NUM>) being engaged with the orbiting wrap (<NUM>) to define a compression chamber, and
at least one refrigerant accommodating groove (<NUM>, <NUM>) recessed to a preset depth from at least one of a side surface of the fixed wrap (<NUM>) and a side surface of the orbiting wrap (<NUM>) constituting the compression chamber,
wherein the compression chamber comprises a first compression chamber (V1) provided in an inner surface of the fixed wrap (<NUM>) and a second compression chamber (V2) provided in an outer surface of the fixed wrap (<NUM>),
characterized in that the fixed end plate (<NUM>) is provided with a first discharge port (<NUM>) configured to discharge refrigerant in the first compression chamber (V1) and a second discharge port (<NUM>) configured to discharge refrigerant of the second compression chamber (V2),
an auxiliary discharge port (<NUM>) is provided between the first discharge port (<NUM>) and the second discharge port (<NUM>),
an inlet of the auxiliary discharge port (<NUM>) is spaced apart from an inlet of the first discharge port (<NUM>) and an inlet of the second discharge port (<NUM>), and
an outlet of the auxiliary discharge port (<NUM>) communicates with an outlet of the first discharge port (<NUM>) and/or an outlet of the second discharge port (<NUM>).