Patent Description:
Generally, a compressor is applied to a vapor compression type refrigeration cycle (hereinafter, referred to as a "refrigeration cycle") used for a refrigerator, or an air conditioner, for example. Compressors may be classified into reciprocating compressors, rotary compressors, and scroll compressors, for example, according to a method of compressing a refrigerant.

The scroll compressor among the above-described compressors is a compressor which performs an orbiting movement by engaging an orbiting scroll with a fixed scroll fixed inside of a sealed container so that a compression chamber is formed between a fixed wrap of the fixed scroll and an orbiting wrap of the orbiting scroll. The scroll compressor is widely used for compressing a refrigerant in an air conditioner, for example, because the scroll compressor can obtain a relatively higher compression ratio than the other types of compressors and can obtain a stable torque because suction, compression, and discharge strokes of the refrigerant are smooth and continuous.

Such scroll compressors may be classified into upper compression type compressors or lower compression type compressors according to a location of a drive motor and a compression component. The compression component is located at a higher level than the drive motor in the upper compression type compressor, and the compression component is located at a lower level than the drive motor in the lower compression type compressor.

In the lower compression type scroll compressor, as there is a short distance between an oil storage chamber and the compression component, oil may be relatively uniformly supplied thereto; however, it may be structurally difficult to supply the oil thereto. More particularly, in a lower compression type scroll compressor which is driven at various speeds from low to high speed, it is important to optimize performance and secure reliability of a bearing portion according to a flow rate of oil. Accordingly, a structural improvement for supplying oil is required for portions, such as a bearing surface or compression chamber, to which it is structurally difficult to supply oil.

<CIT> discloses a scroll compressor that may prevent an oil-feeding hole from being blocked due to a high-pressure refrigerant.

<CIT> discloses a compressor including a fixed wrap, an orbiting scroll having an orbiting wrap engaged with the fixed warp to form compression chambers, the fixed wrap and the orbiting wrap may have irregular wrap curves.

The present invention is defined by claim <NUM>; the dependent claims describe embodiments of the present invention.

Hereinafter, embodiments will be described with reference to accompanying drawings. Where possible, like or similar reference numerals in the drawings have been used to indicate like or similar elements, and repetitive disclosure has been omitted.

Hereinafter, a scroll compressor according to an embodiment will be described with reference to <FIG>.

<FIG> is a cross-sectional view of a scroll compressor according to an embodiment. The scroll compressor according to an embodiment may include a casing <NUM> having an inner space, a drive motor <NUM> provided in an upper portion of the inner space, a compression part or device <NUM> disposed under the drive motor <NUM>, and a rotary shaft <NUM> configured to transmit a drive force of the drive motor <NUM> to the compression device <NUM>.

The inner space of the casing <NUM> may be divided into a first space V1, which may be provided at an upper side of the drive motor <NUM>, a second space V2 between the drive motor <NUM> and the compression device <NUM>, a third space V3 partitioned by a discharge cover <NUM>, and an oil storage chamber V4, which may be provided under the compression device <NUM>.

The casing <NUM>, for example, may have a cylindrical shape, and thus, the casing <NUM> may include a cylindrical shell <NUM>. An upper shell or cover <NUM> may be installed or provided on or at an upper portion of the cylindrical shell <NUM>, and a lower shell or cover <NUM> may be installed or provided on or at a lower portion of the cylindrical shell <NUM>. The upper and lower shells <NUM> and <NUM> may be coupled to the cylindrical shell <NUM> by welding, for example, and may form the inner space thereof.

A refrigerant discharge pipe <NUM> may be installed or provided in the upper shell <NUM>. The refrigerant discharge pipe <NUM> may form a path through which a compressed refrigerant discharged from the compression device <NUM> into the second space V2 and the first space V1 may be discharged to the outside. An oil separator (not shown) configured to separate oil mixed with the discharged refrigerant may be connected to the refrigerant discharge pipe <NUM>.

The lower shell <NUM> may form the oil storage chamber V4 capable of storing oil therein. The oil storage chamber V4 may serve as an oil chamber from which the oil may be supplied to the compression device <NUM> so that the compressor may be smoothly operated.

A refrigerant suction pipe <NUM>, which may form a path through which a refrigerant to be compressed may be introduced, may be installed or provided in or at a side surface of the cylindrical shell <NUM>. The refrigerant suction pipe <NUM> may be installed or provided to penetrate up to a compression chamber S1 along a side surface of a fixed scroll <NUM>.

The drive motor <NUM> may be installed or provided in or at an upper portion inside of the casing <NUM>. The drive motor <NUM> may include a stator <NUM> and a rotor <NUM>.

The stator <NUM>, for example, may have a cylindrical shape, and may be fixed to the casing <NUM>. A plurality of slots (not shown) may be formed in an inner circumferential surface of the stator <NUM> in a circumferential direction, and a coil 222a may be wound on the stator <NUM>. A refrigerant flow groove 212a may be cut in a D-cut shape and may be formed in an outer circumferential surface of the stator <NUM> so that a refrigerant or oil discharged from the compression device <NUM> may pass through the refrigerant flow groove 212a.

The rotor <NUM> may be coupled to an inside of the stator <NUM> and may generate rotational power. Also, the rotary shaft <NUM> may be press-fitted into a center of the rotor <NUM> so that the rotary shaft <NUM> may rotate with the rotor <NUM>. The rotational power generated by the power rotor <NUM> may be transmitted to the compression device <NUM> through the rotary shaft <NUM>.

The compression device <NUM> may include a main frame <NUM>, the fixed scroll <NUM>, an orbiting scroll <NUM>, and the discharge cover <NUM>. The compression device <NUM> may further include an Oldham's ring <NUM>. The Oldham's ring <NUM> may be installed or provided between the orbiting scroll <NUM> and the main frame <NUM>. The Oldham's ring <NUM> may prevent rotation of the orbiting scroll <NUM> and allow orbiting movement of the orbiting scroll <NUM> on the fixed scroll <NUM>.

The main frame <NUM> may be provided under the drive motor <NUM> and may form an upper portion of the compression device <NUM>. The main frame <NUM> may include a frame end plate (hereinafter, a "first end plate") <NUM> having a circular shape, a frame bearing section (hereinafter, a "first bearing section") 232a, which may be provided at a center of the first end plate <NUM> and through which the rotary shaft <NUM> may pass, and a frame sidewall (hereinafter, a "first sidewall") <NUM>, which may protrude downward from an outer circumferential portion of the first end plate <NUM>. An outer circumferential portion of the first sidewall <NUM> may be in contact with an inner circumferential surface of the cylindrical shell <NUM>, and a lower end of the first sidewall <NUM> may be in contact with an upper end of a fixed scroll sidewall <NUM>.

The first sidewall <NUM> may include a frame discharge hole (hereinafter, a "first discharge hole") 231a, which may pass through an inside of the first sidewall <NUM> in an axial direction and form a refrigerant path. An inlet of the first discharge hole 231a may communicate with an outlet of a fixed scroll discharge hole 256b, which will be described hereinafter, and an outlet of the first discharge hole 231a may communicate with the second space V2.

The first bearing section 232a may protrude from an upper surface of the first end plate <NUM> toward the drive motor <NUM>. A first bearing portion may be formed at the first bearing section 232a so that a main bearing portion 226c of the rotary shaft <NUM>, which will be described hereinafter, may pass therethrough and be supported by the first bearing portion. That is, the first bearing section 232a, into which the main bearing portion 226c, which forms the first bearing portion, of the rotary shaft <NUM> is rotatably inserted and by which the main bearing portion 226c is supported by the first bearing section 232a, may be formed at a center of the main frame <NUM> in the axial direction.

An oil pocket 232b configured to collect oil discharged from between the first bearing section 232a and the rotary shaft <NUM> may be formed in an upper surface of the first end plate <NUM>. The oil pocket 232b may be formed by carving the upper surface of the first end plate <NUM> and may be formed in a circular shape along an outer circumferential surface of the first bearing section 232a. In addition, a back pressure chamber S2 may be formed in a lower surface of the main frame <NUM> to form a space with the fixed scroll <NUM> and the orbiting scroll <NUM> to support the orbiting scroll <NUM> using a pressure of the space.

The back pressure chamber S2 may include a medium pressure region, that is, a medium pressure chamber, and an oil supply path 226a provided in the rotary shaft <NUM> may include a high pressure region having a higher pressure than the back pressure chamber S2. A back pressure seal <NUM> may be provided between the main frame <NUM> and the orbiting scroll <NUM> to divide the high pressure region from the medium pressure region, and the back pressure seal <NUM> may serve as a sealing member.

In addition, the main frame <NUM> may be coupled to the fixed scroll <NUM> to form a space in which the orbiting scroll <NUM> may be rotatably installed or provided. That is, such a structure may be a structure which covers the rotary shaft <NUM> to transmit rotational power to the compression device <NUM> through the rotary shaft <NUM>.

The fixed scroll <NUM> forming a first scroll may be coupled to a lower surface of the main frame <NUM>. More specifically, the fixed scroll <NUM> may be provided below the main frame <NUM>.

The fixed scroll <NUM> may include a fixed scroll end plate (a "second end plate") <NUM> having a substantially circular shape, a fixed scroll sidewall (hereinafter, a "second sidewall") <NUM> that protrudes upward from an outer circumferential portion of the second end plate <NUM>, a fixed wrap <NUM> that protrudes from an upper surface of the second end plate <NUM> and is engaged with an orbiting wrap <NUM> of the orbiting scroll <NUM>, which will be described hereinafter, to form the compression chamber S1, and a fixed scroll bearing section (hereinafter, a "second bearing section") <NUM> formed at a center of a rear surface of the second end plate <NUM> and through which the rotary shaft <NUM> may pass.

A discharge hole <NUM> configured to guide a compressed refrigerant from the compression chamber S1 to an inner space of the discharge cover <NUM> may be formed in the second end plate <NUM>. In addition, a position of the discharge hole <NUM> may be arbitrarily determined in consideration of a required discharging pressure, for example.

As the discharge hole <NUM> is formed to face the lower shell <NUM>, the discharge cover <NUM> for accommodating a discharged refrigerant and guiding the discharged refrigerant to the fixed scroll discharge hole 256b, which will be described hereinafter, in a state in which the discharged refrigerant is not mixed with oil, may be coupled to a lower surface of the fixed scroll <NUM>. The discharge cover <NUM> may be hermetically coupled to a lower surface of the fixed scroll <NUM> to separate a discharge path of the refrigerant from the oil storage chamber V4. In addition, a through hole <NUM> may be formed in the discharge cover <NUM> so that an oil feeder <NUM> coupled to a sub-bearing portion <NUM>, which forms a second bearing portion and is submerged in the oil storage chamber V4 of the casing <NUM>, of the rotary shaft <NUM> may pass through the through hole <NUM>.

The second sidewall <NUM> may include a fixed scroll discharge hole (hereinafter, a "second discharge hole") 256b that passes through an inside of the second sidewall <NUM> in the axial direction and forms a refrigerant path with the first discharge hole 231a. The second discharge hole 256b may be formed to correspond to the first discharge hole 231a, an inlet of the second discharge hole 256b may communicate with the inner space of the discharging cover <NUM>, and an outlet of the second discharge hole 256b may communicate with the inlet of the first discharge hole 231a.

The third space V3 may communicate with the second space V2 using the second discharge hole 256b and the first discharge hole 231a to guide a refrigerant, which is discharged from the compression chamber S1 to the inner space of the discharge cover <NUM>, to the second space V2. In addition, the refrigerant suction pipe <NUM> may be installed or provided in the second sidewall <NUM> to communicate with a suction side of the compression chamber S1. The refrigerant suction pipe <NUM> may be spaced apart from the second discharge hole 256b.

The second bearing section <NUM> may protrude from a lower surface of the second end plate <NUM> toward the oil storage chamber V4. The second bearing section <NUM> may include the second bearing portion so that the sub-bearing portion <NUM> of the rotary shaft <NUM> may be inserted into and supported by the second bearing portion. A lower end of the second bearing section <NUM> may be bent toward a center of the shaft to support a lower end of the sub-bearing portion <NUM> of the rotary shaft <NUM> to form a thrust bearing surface.

The orbiting scroll <NUM> forming a second scroll may be installed or provided between the main frame <NUM> and the fixed scroll <NUM>. More specifically, the orbiting scroll <NUM> may be coupled to the rotary shaft <NUM>, to perform an orbiting movement and form two compression chambers S1, that is, a pair of compression chambers S1, between the orbiting scroll <NUM> and the fixed scroll <NUM>.

The orbiting scroll <NUM> may include an orbiting scroll end plate (hereinafter, a "third end plate") <NUM> having a substantially circular shape, the orbiting wrap <NUM> which protrudes from a lower surface of the third end plate <NUM> and is engaged with the fixed wrap <NUM>, and a rotary shaft coupler <NUM> provided at a center of the third end plate <NUM> and rotatably coupled to an eccentric portion 226f of the rotary shaft <NUM>. In the orbiting scroll <NUM>, an outer circumferential portion of the third end plate <NUM> may be located at an upper end of the second sidewall <NUM>, and a lower end of the orbiting wrap <NUM> may be pressed against an upper surface of the second end plate <NUM> so that the orbiting scroll <NUM> may be supported by the fixed scroll <NUM>.

A pocket groove <NUM> to guide oil discharged through oil holes 228a, 228b, 228d, and 228e, which will be described hereinafter, to the medium pressure chamber may be formed in an upper surface of the orbiting scroll <NUM>. More specifically, the pocket groove <NUM> may be formed by carving an upper surface of the third end plate <NUM>. That is, the pocket groove <NUM> may be formed in the upper surface of the third end plate <NUM> between the back pressure seal <NUM> and the rotary shaft <NUM>.

As illustrated in the drawing, one pocket groove <NUM> may be formed at each of both sides of the rotary shaft <NUM>; however, a plurality of pocket grooves <NUM> may also be formed at each of both sides of the rotary shaft <NUM>. When the plurality of pocket grooves <NUM> is formed, the plurality of pocket grooves may be spaced a predetermined distance from each other on the upper surface of the third end plate <NUM> between the back pressure seal <NUM> and the rotary shaft <NUM>. The pocket groove <NUM> may also be formed around the rotary shaft <NUM> in a circular shape on the upper surface of the third end plate <NUM> between the back pressure seal <NUM> and the rotary shaft <NUM>.

An outer circumferential portion of the rotary shaft coupler <NUM> may be connected to the orbiting wrap <NUM> to form the compression chamber S1 with the fixed wrap <NUM> during a compression process. The fixed wrap <NUM> and the orbiting wrap <NUM> may be formed in an involute shape, but may also be formed in any of various shapes other than the involute shape. The term "involute shape" refers to a curved line corresponding to a trajectory drawn by an end of a thread when the thread wound around a base circle having an arbitrary radius is released.

The eccentric portion 226f of the rotary shaft <NUM> may be inserted into the rotary shaft coupler <NUM>. The eccentric portion 226f inserted into the rotary shaft coupler <NUM> may overlap the orbiting wrap <NUM> or the fixed wrap <NUM> in a radial direction of the compressor.

The term "radial direction" may refer to a direction, that is, a lateral direction, perpendicular to an axial direction, that is, a vertical direction. More specifically, the radial direction may refer to a direction from an outside of the rotary shaft to an inside thereof.

As described above, when the eccentric portion 226f of the rotary shaft <NUM> passes through the third end plate <NUM> and overlaps the orbiting wrap <NUM> in the radial direction, a repulsive force and a compressive force of a refrigerant may be applied to a same plane based on the third end plate <NUM> to be partially canceled. In addition, the rotary shaft <NUM> may be coupled to the drive motor <NUM> and include the oil supply path 226a to guide the oil stored in the oil storage chamber V4 of the casing <NUM> upward. More specifically, an upper portion of the rotary shaft <NUM> may be press-fitted into and coupled to a center of the rotor <NUM>, and a lower portion of the rotary shaft <NUM> may be coupled to the compression device <NUM> and supported in the radial direction by the compression device <NUM>.

Accordingly, the rotary shaft <NUM> may transmit a rotational force of the drive motor <NUM> to the orbiting scroll <NUM> of the compression device <NUM>. In addition, the orbiting scroll <NUM> eccentrically coupled to the rotary shaft <NUM> may perform an orbiting movement with respect to the fixed scroll <NUM> using the transmitted rotational force.

A main bearing portion 226c may be formed at a lower portion of the rotary shaft <NUM> to be inserted into the first bearing section 232a of the main frame <NUM> and supported in a radial direction by the first bearing section 232a. In addition, the sub-bearing portion <NUM> may be formed under the main bearing portion 226c to be inserted into the second bearing section <NUM> of the fixed scroll <NUM> and supported in the radial direction by the second bearing section <NUM>. In addition, the eccentric portion 226f may be formed between the main bearing portion 226c and the sub-bearing portion <NUM> to be inserted into and coupled to the rotary shaft coupler <NUM> of the orbiting scroll <NUM>.

The main bearing portion 226c and the sub-bearing portion <NUM> may be coaxially formed to have a same axial center, and the eccentric portion 226f may be eccentrically formed in the radial direction with respect to the main bearing portion 226c or the sub-bearing portion <NUM>. For example, the eccentric portion 226f may have an outer diameter smaller than an outer diameter of the main bearing portion 226c and larger than an outer diameter of the sub-bearing portion <NUM>. In this case, the rotary shaft <NUM> may have an advantage in that the rotary shaft <NUM> may pass through and be coupled to the bearing sections 232a and <NUM> and the rotary shaft coupler <NUM>.

Conversely, the eccentric portion 226f may not be formed integrally with the rotary shaft <NUM> but may be formed using a separate bearing. In this case, even when the sub-bearing portion <NUM> is not formed to have an outer diameter which is smaller than an outer diameter of the eccentric portion 226f, the rotary shaft <NUM> may be inserted into and coupled to the bearing sections 232a and <NUM> and the rotary shaft coupler <NUM>.

The oil supply path 226a to supply the oil of the oil storage chamber V4 to circumferential surfaces of the bearing portions 226c and <NUM> and a circumferential surface of the eccentric portion 226f may be formed in the rotary shaft <NUM>. In addition, the oil holes 228a, 228b, 228d, and 228e which may pass from the oil supply path 226a to the outer circumferential surface thereof may be formed in the bearing portions and eccentric portion 226c, <NUM>, and 226f of the rotary shaft <NUM>. More specifically, the oil holes may include a first oil hole 228a, a second oil hole 228b, a third oil hole 228d, and a fourth oil hole 228e.

The first oil hole 228a may pass through an outer circumferential surface of the main bearing portion 226c. More specifically, the first oil hole 228a may pass from the oil supply path 226a to an outer circumferential surface of the main bearing portion 226c.

In addition, the first oil hole 228a may pass through, for example, an upper portion of the outer circumferential surface of the main bearing portion 226c; however, embodiments are not limited thereto. That is, the first oil hole 228a may pass through a lower portion of the outer circumferential surface of the main bearing portion 226c.

Unlike the drawing, a plurality of first oil holes 228a may be formed. In addition, when the plurality of first oil holes 228a is formed, the holes may be formed in only the upper or lower portion of the outer circumferential surface of the main bearing portion 226c or formed in both of the upper and lower portions of the outer circumferential surface of the main bearing portion 226c. However, in this embodiment, one first oil hole 228a is shown for sake of convenience of description.

A first oil groove 229a (see <FIG>), which may be obliquely or spirally formed and have a first end connected to the first oil hole 228a, may be formed in the outer circumferential surface of the main bearing portion 226c. More specifically, as the first end of the first oil groove 229a (see <FIG>) is formed to be connected to the first oil hole 228a, some oil discharged from the first oil hole 228a may be efficiently supplied to the outer circumferential surface of the main bearing portion 226c via the first oil groove 229a (see <FIG>). That is, some of the oil discharged from the first oil hole 228a may flow through the first oil groove 229a (see <FIG>) and be supplied to upper, lower, and lateral sides of the outer circumferential surface of the main bearing portion 226c. The remaining oil discharged from the first oil hole 228a may be directly supplied to the upper, lower, and lateral sides of the outer circumferential surface of the main bearing portion 226c around the first oil hole 228a. The first oil groove 229a (see <FIG>) may be obliquely formed in a direction or an opposite direction of rotation of the rotary shaft <NUM>. That is, the first oil groove 229a (see <FIG>) may obliquely extend between the axial direction and the rotational direction (or the opposite direction of rotation) of the rotary shaft <NUM>.

Unlike the drawing, a plurality of first oil grooves 229a (see <FIG>) may be formed. For example, when the plurality of first oil grooves 229a (see <FIG>) is formed, and one first oil hole 228a is formed, one end of each of the grooves may be connected to the first oil hole 228a.

In addition, when the plurality of first oil grooves 229a (see <FIG>) is formed and the plurality of first oil holes 228a is also formed, one end of each of the grooves may be connected to the holes one to one. However, in this embodiment, the first oil groove 229a (see <FIG>) including one groove is shown for the sake of convenience of description.

The second oil hole 228b may be formed between the main bearing portion 226c and the eccentric portion 226f. More specifically, the second oil hole 228b may be formed in a first small diameter portion <NUM> by which the main bearing portion 226c and the eccentric portion 226f are spaced a predetermined distance from each other. That is, the second oil hole 228b may pass from the oil supply path 226a to an outer circumferential surface of the first small diameter portion <NUM>.

The first small diameter portion <NUM> may be provided to secure processibility for forming the main bearing portion 226c and the eccentric portion 226f in a grinding process. In addition, the first small diameter portion <NUM> may also be provided to secure a damping space for continuously supplying oil guided upward through the rotary shaft <NUM>.

Unlike the drawing, a plurality of second oil holes 228b may be formed. In addition, when the plurality of second oil holes 228b is formed, the holes may be spaced a predetermined distance from each other in the first small diameter portion <NUM>. However, in this embodiment, one second oil hole 228b is shown for sake of convenience of description.

The third oil hole 228d may pass through an outer circumferential surface of the eccentric portion 226f. More specifically, the third oil hole 228d may pass from the oil supply path 226a to the outer circumferential surface of the eccentric portion 226f. In addition, the third oil hole 228d may pass through, for example, a central portion of the outer circumferential surface of the eccentric portion 226f; however, embodiments are not limited thereto. That is, the third oil hole 228d may also pass through an upper or lower portion of the outer circumferential surface of the eccentric portion 226f.

Unlike the drawing, a plurality third oil holes 228d may be formed. In addition, when the plurality of third oil holes 228d is formed, the holes may be formed only in a middle region of the outer circumferential surface of the eccentric portion 226f or formed at both of the upper and lower portions of the outer circumferential surface of the eccentric portion 226f. However, in this embodiment, one third oil hole 228d is shown for sake of convenience of description.

A second oil groove 229b (see <FIG>) may be formed in the outer circumferential surface of the eccentric portion 226f to be connected to the third oil hole 228d and perpendicularly extend therefrom. More specifically, as the third oil hole 228d is formed at a central portion of the second oil groove 229b (see <FIG>), some oil discharged from the third oil hole 228d may be efficiently supplied to the outer circumferential surface of the eccentric portion 226f via the second oil groove 229b (see <FIG>). That is, some of the oil discharged from the third oil hole 228d may flow through the second oil groove 229b (see <FIG>) and be supplied to upper, lower, and lateral sides of the outer circumferential surface of the eccentric portion 226f. The remaining oil discharged from the third oil hole 228d may be directly supplied to the upper, lower, and lateral sides of the outer circumferential surface of the eccentric portion 226d around the third oil hole 228d.

However, the third oil hole 228d may also be formed in an upper or lower portion of the second oil groove 229b (see <FIG>). In addition, the second oil groove 229b (see <FIG>) may extend straight in a vertical or longitudinal direction, as illustrated in the drawing, but may also be obliquely or spirally formed in the longitudinal direction in some cases.

Unlike the drawing, a plurality of second oil grooves 229b (see <FIG>) may be formed. For example, when the plurality of second oil grooves 229b (see <FIG>) is formed, the plurality of third oil holes 228d may also be formed, and a hole may also be formed in a central portion of each of the grooves. However, in this embodiment, one second oil groove 229b (see <FIG>) is shown for sake of convenience of description.

Lastly, the fourth oil hole 228e may be formed between the eccentric portion 226f and the sub-bearing portion <NUM>. More specifically, the fourth oil hole 228e may be formed in a second small diameter portion <NUM> by which the eccentric portion 226f and the sub-bearing portion <NUM> are spaced a predetermined distance from each other. That is, the fourth oil hole 228e may pass from the oil supply path 226a to an outer circumferential surface of the second small diameter portion <NUM>.

The second small diameter portion <NUM> may be provided to secure processibility for forming the eccentric portion 226f and the sub-bearing portion <NUM> in a grinding process. In addition, the second small diameter portion <NUM> may also secure a damping space for continuously supplying oil guided upward through the rotary shaft <NUM>.

Unlike the drawing, a plurality of fourth oil holes 226e may be formed. In addition, when the plurality of fourth oil holes 226e is formed, the holes may be spaced a predetermined distance from each other in the second small diameter portion <NUM>. However, in this embodiment, one fourth oil hole 226e is shown for sake of convenience of description.

Thus, oil guided upward through the oil supply path 226a may be discharged through the first oil hole 228a and supplied to the entire outer circumferential surface of the main bearing portion 226c. In addition, the oil guided upward through the oil supply path 226a may be discharged through the second oil hole 228b to be supplied to the upper surface of the orbiting scroll <NUM>, and discharged through the third oil hole 228d to be supplied to the entire outer circumferential surface of the eccentric portion 226f. The oil guided upward through the oil supply path 226a may be discharged through the fourth oil hole 228e and supplied to the outer circumferential surface of the sub-bearing portion <NUM> or supplied between the orbiting scroll <NUM> and the fixed scroll <NUM>.

Additional oil holes (not shown) may pass from the oil supply path 226a to the outer circumferential surface of the sub-bearing portion <NUM>. In addition, oil discharged through the additional oil holes may also be supplied to the entire outer circumferential surface of the sub-bearing portion <NUM>.

The oil feeder <NUM> that pumps oil from the oil storage chamber V4 may be coupled to a lower end of the rotary shaft <NUM>, that is, a lower end of the sub-bearing portion <NUM>. The oil feeder <NUM> may be formed with an oil supply pipe <NUM> inserted into and coupled to the oil supply path 226a of the rotary shaft <NUM>, and an oil suction pump <NUM> inserted into the oil supply pipe <NUM> and configured to suction oil. The oil supply pipe <NUM> may be installed or provided to pass through the through hole <NUM> of the discharge cover <NUM> and be submerged in the oil storage chamber V4, and the oil suction pump <NUM> may function like a propeller.

Although not illustrated in the drawing, a trochoid pump (not shown) may be coupled to the sub-bearing portion <NUM> instead of the oil feeder <NUM> to forcibly pump the oil contained in the oil storage chamber V4. Further, although not illustrated in the drawing, the scroll compressor according to an embodiment may further include a first sealing member or seal (not shown) that seals a gap between an upper end of the main bearing portion 226c and an upper end of the main frame <NUM>, and a second sealing member or seal (not shown) that seals a gap between a lower end of the sub-bearing portion <NUM> and a lower end of the fixed scroll <NUM>. Leakage of oil to an outside of the compression device <NUM> along a bearing surface, that is, an outer circumferential surface of a bearing portion, may be prevented by the first and second sealing members or seals to realize a differential pressure structure for supplying oil and prevent backflow of a refrigerant.

A balance weight <NUM> that suppresses noise and vibration may be coupled to the rotor <NUM> or the rotary shaft <NUM>. The balance weight <NUM> may be provided between the drive motor <NUM> and the compression device <NUM>, that is, in the second space V2.

Am operation process of the scroll compressor according to an embodiment will be described hereinafter.

When power is applied to the drive motor <NUM> and a rotational force is generated, the rotary shaft <NUM> coupled to the rotor <NUM> of the drive motor <NUM> is rotated. Accordingly, the orbiting scroll <NUM> eccentrically coupled to the rotary shaft <NUM> may perform an orbiting movement with respect to the fixed scroll <NUM> and form the compression chamber S1 between the orbiting wrap <NUM> and the fixed wrap <NUM>. The compression chamber S1 may be continuously formed in several steps such that a volume thereof gradually decreases toward a center thereof.

Then, a refrigerant supplied from outside of the casing <NUM> through the refrigerant suction pipe <NUM> may directly flow into the compression chamber S1. The refrigerant may be compressed while being moved toward a discharge chamber of the compression chamber S1 by the orbiting movement of the orbiting scroll <NUM> to be discharged from the discharge chamber to the third space V3 through the discharge hole <NUM> of the fixed scroll <NUM>. Next, a series of processes in which the compressed refrigerant discharged to the third space V3 is discharged to the inner space of the casing <NUM> through the second discharge hole 256b and the first discharge hole 231a, and is discharged to the outside of the casing <NUM> through the refrigerant discharge pipe <NUM> may be repeated.

Hereinafter, a structure for supplying oil of the scroll compressor of <FIG> according to an embodiment will be described with reference to <FIG> and <FIG>.

<FIG> and <FIG> are schematic views of a structure for supplying oil of the scroll compressor of <FIG> according to an embodiment. An oil flow according to a centrifugation structure for supplying oil is illustrated in <FIG>, and an oil flow according to a differential pressure structure for supplying oil is illustrated in <FIG>. More specifically, oil stored in the oil storage chamber V4 (see <FIG>) may be guided, that is, moved or supplied, upward through the oil supply path 226a (see <FIG>) of the rotary shaft <NUM>.

As illustrated in <FIG>, the oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through the first oil hole 228a and supplied to the entire outer circumferential surface of the main bearing portion 226c. The oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through the second oil hole 228b and supplied to the upper surface of the orbiting scroll <NUM>, that is, the upper surface of the third end plate <NUM> (see <FIG>). The oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through the third oil hole 228d and supplied to the entire outer circumferential surface of the eccentric portion 226f. The oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through the fourth oil hole 228e and supplied to the outer circumferential surface of the sub-bearing portion <NUM> or supplied between the orbiting scroll <NUM> and the fixed scroll <NUM>.

As described above, the oil stored in the oil storage chamber V4 may be guided upward through the rotary shaft <NUM> and easily supplied to the bearing portion, that is, the bearing surface, through the plurality of oil holes 228a, 228b, 228d, and 228e so that wear of the bearing portion may be prevented. The oil discharged through the plurality of oil holes 228a, 228b, 228d, and 228e may form an oil film between the fixed scroll <NUM> and the orbiting scroll <NUM> to maintain a hermetic state therebetween. The oil discharged through the plurality of oil holes 228a, 228b, 228d, and 228e may also absorb frictional heat generated by friction to dissipate heat from the high temperature compression device <NUM>.

The oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through an oil hole, for example, the second oil hole 228b, and supplied to the upper surface of the orbiting scroll <NUM>. In addition, the oil supplied to the upper surface of the orbiting scroll <NUM> may be guided to the medium pressure chamber S2 through the pocket groove <NUM>.

That is, as illustrated in <FIG>, the oil guided upward through the oil supply path 226a (see <FIG>) may be discharged through an oil hole, for example, the second oil hole 228b, and guided to the pocket groove <NUM>. The oil guided to the pocket groove <NUM> may be supplied to the medium pressure chamber S2 by the orbiting movement of the orbiting scroll <NUM>. Oil discharged through the second oil hole 228b and the first oil hole 228a or the third oil hole 228d may also be supplied to the pocket groove <NUM>.

The oil guided to the medium pressure chamber S2 may be supplied to a thrust surface of the fixed scroll <NUM> and the Oldham's ring <NUM> installed between the orbiting scroll <NUM> and the main frame <NUM>. That is, the oil that flows into the medium pressure chamber S2 may be sufficiently supplied to the thrust surface of the fixed scroll <NUM> and the Oldham's ring <NUM>. Accordingly, wear of the thrust surface of the fixed scroll <NUM> and the Oldham's ring <NUM> may be reduced.

The oil guided to the medium pressure chamber S2 may be guided to a differential pressure path <NUM> that supplies oil included in the fixed scroll <NUM>. More specifically, the fixed scroll <NUM> of the scroll compressor of <FIG> may further include the differential pressure path <NUM> which guides the oil guided to the medium pressure chamber S2 to the compression chamber S1.

The differential pressure path <NUM> may pass through the second sidewall <NUM> and the second end plate <NUM>; however, embodiments are not limited thereto. That is, the differential pressure path <NUM> may pass through only the second sidewall <NUM>. In this case, the differential pressure path <NUM> may have a shorter length than the differential pressure path <NUM> which passes through both the second sidewall <NUM> and the second end plate <NUM>.

One or a first end of the differential pressure path <NUM> may communicate with the medium pressure chamber S2, and the other or a second end of the differential pressure path <NUM> may communicate with the compression chamber S1. Accordingly, oil guided to the differential pressure path <NUM> may be supplied to the compression chamber S1.

As described above, the oil stored in the oil storage chamber V4 may be easily supplied to the compression chamber S1 through the pocket groove <NUM> and the differential pressure path <NUM>. As oil is easily supplied to the compression chamber S1, wear due to friction between the orbiting scroll <NUM> and the fixed scroll <NUM> may be reduced so that compression efficiency may be improved.

The oil supplied to the compression chamber S1 may form an oil film between the fixed scroll <NUM> and the orbiting scroll <NUM> to maintain a hermetic state therebetween. Further, the oil supplied to the compression chamber S1 may also absorb frictional heat generated by friction between the fixed scroll <NUM> and the orbiting scroll <NUM> to dissipate the heat.

Hereinafter, structure for supplying oil of the scroll compressor of <FIG> according to another embodiment will be described with reference to <FIG> and <FIG>.

<FIG> and <FIG> are schematic views of a structure for supplying oil of the scroll compressor of <FIG> according to another embodiment. An oil flow according to a centrifugation structure for supplying oil is illustrated in <FIG>, and an oil flow according to a differential pressure structure for supplying oil is illustrated in <FIG>. However, as the oil flow according to the centrifugation structure for supplying oil and the pocket groove <NUM> illustrated in <FIG> may be the same as that of the previous embodiment illustrated in <FIG>, repetitive description thereof has been omitted.

The main frame <NUM> of the scroll compressor of <FIG> may further include a first differential pressure path <NUM> configured to receive oil discharged through an oil hole, for example, the second oil hole 228b. Oil discharged through the second oil hole 228b and the first oil hole 228a or third oil hole 228d may also be supplied to the first differential pressure path <NUM>.

The first differential pressure path <NUM> may bypass the medium pressure chamber S2, that is, pass through the first end plate <NUM> and the first sidewall <NUM>. That is, one or a first end of the first differential pressure path <NUM> may be connected to a high-pressure region to receive oil and the other or a second end of the first differential pressure path <NUM> may be connected to one or a first end of a second differential pressure path <NUM>. The high-pressure region may refer to a region between the first small diameter portion <NUM> and the first end of the first differential pressure path <NUM>.

The fixed scroll <NUM> may further include the second differential pressure path <NUM> to guide oil received from the first differential pressure path <NUM> to the compression chamber S1. The second differential pressure path <NUM> may pass through the second sidewall <NUM> and the second end plate <NUM>. That is, the first end of the second differential pressure path <NUM> may be connected to the second end of the first differential pressure path <NUM> and the other or a second end of the second differential pressure path <NUM> may be connected to the compression chamber S1.

The main frame <NUM> may further include a first opening <NUM>, which opens a portion of the first differential pressure path <NUM> at a side surface of the first end plate <NUM>, and a first coupling member <NUM>, which seals the first opening <NUM>. The fixed scroll <NUM> may further include a second opening <NUM>, which opens a portion of the second differential pressure path <NUM> at a lower surface of the second end plate <NUM>, and a second coupling member <NUM>, which seals the second opening <NUM>.

Each of the first coupling member <NUM> and the second coupling member <NUM> may be one of, for example, a bolt (when a fastening method is applied), a rod (when a press-fitting method is applied), and a ball (when a press-fitting method is applied); however, embodiments are not limited thereto.

In addition, the first opening <NUM> may be used to insert a first decompression pin <NUM> into the first differential pressure path <NUM>, and the second opening <NUM> may be used to insert a second decompression pin <NUM> into the second differential pressure path <NUM>. When the first and second decompression pins <NUM> and <NUM> are respectively inserted into the first and second differential pressure paths <NUM> and <NUM>, the first and second coupling members <NUM> and <NUM> may be respectively coupled to the first and second openings <NUM> and <NUM>. That is, as the first coupling member <NUM> and the second coupling member <NUM> are respectively coupled to the first opening <NUM> and the second opening <NUM>, pressures in the first differential pressure path <NUM> and the second differential pressure path <NUM> may be maintained.

In addition, the first decompression pin <NUM> may be provided in the first differential pressure path <NUM>, and the second decompression pin <NUM> may be provided in the second differential pressure path <NUM>. A diameter of the first decompression pin <NUM> may be smaller than a diameter of the first differential pressure path <NUM>, and a diameter of the second decompression pin <NUM> may be smaller than a diameter of the second differential pressure path <NUM>. In this way, the first decompression pin <NUM> may form a narrow path in the first differential pressure path <NUM> through which oil may flow so that a pressure and a flow rate of oil in the first differential pressure path <NUM> may be adjusted. In addition, the second decompression pin <NUM> may form a narrow path in the second differential pressure path <NUM> through which oil may flow so that a pressure and a flow rate of oil in the second differential pressure path <NUM> may be adjusted.

A decompression pin may also be provided in only one of the first differential pressure path <NUM> or the second differential pressure path <NUM>. However, in this embodiment, a decompression pin is shown as being provided in each of the first differential pressure path <NUM> and the second differential pressure path <NUM> for the sake of convenience of description.

As described above, the oil stored in the oil storage chamber V4 may be easily supplied to the compression chamber S1 through the first differential pressure path <NUM> and the second differential pressure path <NUM>. In addition, as oil is easily supplied to the compression chamber S1, the same effects as that of the previously described embodiment, that is, reduction of wear, maintenance of the hermetic state, and dissipation of heat, for example, may be obtained using this embodiment.

Hereinafter, a structure for supplying oil of the scroll compressor of <FIG> according to still another embodiment will be described with reference to <FIG> and <FIG>.

<FIG> and <FIG> are schematic views of a structure for supplying oil of the scroll compressor of <FIG>. An oil flow according to a centrifugation structure for supplying oil is illustrated in <FIG>, and an oil flow according to a differential pressure structure for supplying oil is illustrated in <FIG>. However, as the oil flow according to the centrifugation structure for supplying oil and the pocket groove <NUM> illustrated in <FIG> may be the same as that of the embodiment illustrated in <FIG>, repetitive description thereof has been omitted.

The orbiting scroll <NUM> of the scroll compressor of <FIG> may further include a first differential pressure path <NUM> configured to receive oil discharged through an oil hole, for example, the second oil hole 228b. Oil discharged through the second oil hole 228b and the first oil hole 228a or the third oil hole 228d may also be supplied to the first differential pressure path <NUM>.

The first differential pressure path <NUM> may pass through the third end plate <NUM>. In this way, one or a first end of the first differential pressure path <NUM> may be connected to a high pressure region to receive oil and the other or a second end of the first differential pressure path <NUM> may be connected to one or a first end of a second differential pressure path <NUM>. The high pressure region may refer to a region between the first small diameter portion <NUM> and the first end of the first differential pressure path <NUM>.

The fixed scroll <NUM> may further include the second differential pressure path <NUM> to guide oil provided from the first differential pressure path <NUM> to the compression chamber S1. The second differential pressure path <NUM> may pass through the second sidewall <NUM> and the second end plate <NUM>.

In this way, the first end of the second differential pressure path <NUM> may be connected to the second end of the first differential pressure path <NUM> and the other or a second end of the second differential pressure path <NUM> may be connected to the compression chamber S1. However, some oil discharged through the second end of the first differential pressure path <NUM> may be supplied to the second differential pressure path <NUM> by the orbiting movement of the orbiting scroll <NUM>, and some of the remaining oil may be supplied to the thrust surface of the fixed scroll <NUM>.

The orbiting scroll <NUM> may further include a first opening <NUM>, which opens a portion of the first differential pressure path <NUM> at a side surface of the third end plate <NUM>, and a first coupling member <NUM>, which seals the first opening <NUM>. The fixed scroll <NUM> may further include a second opening <NUM>, which opens a portion of the second differential pressure path <NUM> at a lower surface of the second end plate <NUM>, and a second coupling member <NUM>, which seals the second opening <NUM>. Each of the first coupling member <NUM> and the second coupling member <NUM> may be one of, for example, a bolt (when a fastening method is applied), a rod (when a press-fitting method is applied), and a ball (when a press-fitting method is applied); however, embodiments are not limited thereto.

The first opening <NUM> may be used to insert a first decompression pin <NUM> into the first differential pressure path <NUM>, and the second opening <NUM> may be used to insert a second decompression pin <NUM> into the second differential pressure path <NUM>. When the first and second decompression pins <NUM> and <NUM> are respectively inserted into the first and second differential pressure paths <NUM> and <NUM>, the first and second coupling members <NUM> and <NUM> may be respectively coupled to the first and second openings <NUM> and <NUM>. That is, as the first coupling member <NUM> and the second coupling member <NUM> are respectively coupled to the first opening <NUM> and the second opening <NUM>, pressures in the first differential pressure path <NUM> and the second differential pressure path <NUM> may be maintained.

In addition, the first decompression pin <NUM> may be provided in the first differential pressure path <NUM>, and the second decompression pin <NUM> may be provided in the second differential pressure path <NUM>. A diameter of the first decompression pin <NUM> may be smaller than a diameter of the first differential pressure path <NUM>, and a diameter of the second decompression pin <NUM> may be smaller than a diameter of the second differential pressure path <NUM>.

In this way, the first decompression pin <NUM> may form a narrow path in the first differential pressure path <NUM> through which oil may flow such that a pressure and a flow rate of oil in the first differential pressure path <NUM> may be adjusted. In addition, the second decompression pin <NUM> may form a narrow path in the second differential pressure path <NUM> through which oil may flow such that a pressure and a flow rate of oil in the second differential pressure path <NUM> may be adjusted.

A decompression pin may also be provided in only one of the first differential pressure path <NUM> or the second differential pressure path <NUM>. However, in this embodiment, a decompression pin is shown as being provided in each of the first differential pressure path <NUM> and the second differential pressure path <NUM> for sake of convenience of description.

As described above, the oil stored in the oil storage chamber V4 may be easily supplied to the compression chamber S1 through the first differential pressure path <NUM> and the second differential pressure path <NUM>. In addition, as oil is easily supplied to the compression chamber S1, the same effect as that of the previously described embodiment, that is, reduction of wear, maintenance of the hermetic state, and dissipation of heat, for example, may be obtained using this embodiment.

As described above, in the scroll compressor according to embodiments, as the oil stored in the oil storage chamber V4 may be easily supplied to the bearing portion, particularly, the bearing surface, through the centrifugation structure based on the rotary shaft <NUM>, wear of the bearing portion may be prevented. In addition, as the wear of the bearing portion is prevented, reliability of the bearing portion may be secured.

In addition, in the scroll compressor according embodiments, as the oil stored in the oil storage chamber V4 may be easily supplied to the compression chamber S1 through various differential pressure structures, wear due to friction between the orbiting scroll <NUM> and the fixed scroll <NUM> may be reduced such that compression efficiency may be improved.

In addition, in the scroll compressor according to embodiments, an oil film may be formed between the fixed scroll <NUM> and the orbiting scroll <NUM> using the centrifugation structure and the differential pressure structure, the hermetic state may be maintained, and a frictional heat generated by a friction portion may also be absorbed to dissipate heat from the high temperature compression device <NUM>.

As described above, in a scroll compressor according to embodiments, as oil stored in an oil storage chamber may be easily supplied to a bearing portion using a centrifugation structure using a rotary shaft, wear of the bearing portion may be prevented. In addition, as the wear of the bearing portion is prevented, reliability of the bearing portion may be secured.

Further, in a scroll compressor according to embodiments, oil stored in a storage chamber may be easily supplied to a compression chamber through various differential pressure structures, wear due to friction between an orbiting scroll and a fixed scroll may be reduced, and compression efficiency improved.

Embodiments disclosed herein are directed to a scroll compressor capable of smoothly supplying oil stored in an oil storage chamber to a bearing portion through a centrifugation structure using a rotary shaft. Embodiments disclosed herein are also directed to a scroll compressor capable of smoothly supplying oil stored in an oil storage chamber to a compression room through one of various differential pressure structures.

While embodiments have been described for those skilled in the art, it should be understood that the embodiments may be replaced, modified, and changed without departing from the scope of the appended claims, and thus, embodiments are not limited to the described embodiments and the accompanying drawings.

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

Claim 1:
A scroll compressor, comprising:
an oil storage chamber (V4), disposed at a lower portion of the scroll compressor, for storing oil;
a drive motor (<NUM>) for driving a compression device (<NUM>),
the compression device (<NUM>), disposed above the oil storage chamber (V4) and below the drive motor (<NUM>),
wherein the compression device (<NUM>) includes:
a rotary shaft (<NUM>) coupled to the drive motor (<NUM>), including therein: an oil supply path (226a) extending upright for flowing the oil stored in the oil storage chamber (V4) upward; and at least one oil hole (228a, 228b, 228d, 228e) for passing oil from the oil supply path (226a) to an outer circumferential surface of the rotary shaft (<NUM>);
a main frame (<NUM>);
a fixed scroll (<NUM>) provided under the main frame (<NUM>); and
an orbiting scroll (<NUM>), arranged between the main frame (<NUM>) and the fixed scroll (<NUM>), for performing an orbiting movement, being engaged with the fixed scroll (<NUM>), to thereby form a compression chamber (S1) together with the fixed scroll (<NUM>),
wherein the main frame (<NUM>), the fixed scroll (<NUM>), and the orbiting scroll (<NUM>) are configured to form therebetween a medium pressure chamber which has lower pressure compared to the oil supply path (226a), and
wherein the scroll compressor further comprises a differential pressure path for guiding the oil discharged from the at least one oil hole (228a, 228b, 228d, 228e) to the compression chamber (S1), the differential pressure path including a fixed scroll differential pressure path (<NUM>, <NUM>, <NUM>) formed through the fixed scroll (<NUM>),
characterized in that the scroll compressor further comprises a second decompression pin (<NUM>, <NUM>) provided in the fixed scroll differential pressure path (<NUM>, <NUM>, <NUM>), and
the differential pressure path further includes a main frame differential pressure path (<NUM>) formed through the main frame (<NUM>) or an orbiting scroll differential pressure path (<NUM>) formed through the orbiting scroll (<NUM>).