Patent Description:
Generally, a compressor refers to an apparatus which compresses a refrigerant. Compressors can be classified into a reciprocating type, a centrifugal type, a vane type, and a scroll type.

Among the above, a rotary compressor is a compressor using a method of compressing a refrigerant using a roller (or referred to as a "rolling piston") and a vane. In the rotary compressor, a roller eccentrically rotates in a compression space of a cylinder. Further, the vane comes into contact with an outer circumferential surface of the roller to partition the compression space of the cylinder into a suction chamber and a discharge chamber.

According to the above-described rotary compressor, since the roller revolves in the cylinder, the vane inserted into and mounted in the cylinder moves linearly. Accordingly, a compression chamber of which a volume is variable is formed in each of the suction chamber and the discharge chamber formed in the cylinder, and thus suction, compression, and discharge of the refrigerant are performed.

In the conventional rotary compressor having the above-described configuration, there is a problem in that the refrigerant leaks between the roller and the vane and thus the performance of the compressor is degraded.

Recently, in order to solve leakage between the roller and the vane, a rotary compressor having a combined vane-roller structure, which is a structure in which the vane is inserted into and combined with the roller, is introduced.

<FIG> is a longitudinal sectional view illustrating an example of a rotary compressor having the conventional combined vane-roller structure, <FIG> is a lateral sectional view illustrating a compression mechanism of the rotary compressor shown in <FIG>, and <FIG> is a schematic diagram for describing an operation of a main component of the rotary compressor shown in <FIG>.

Referring to <FIG> and <FIG>, in the conventional rotary compressor, an electric motor part and a compression mechanism driven by the electric motor part are accommodated in an airtight container <NUM>, and oil accumulates at a bottom portion of the airtight container <NUM>.

The compression mechanism includes a cylinder <NUM>, an upper bearing <NUM> and a lower bearing <NUM> fastened to both cross-sections of the cylinder <NUM> to form a cylinder chamber <NUM>, a piston <NUM> (or a roller, hereinafter, referred to as a "roller") fitted onto an eccentric portion 4A of the shaft <NUM> located between the upper bearing <NUM> and the lower bearing <NUM>, and a vane <NUM> which reciprocates in a vane groove <NUM> formed in a radial direction of the cylinder <NUM>.

Further, a front end portion 11A of the vane <NUM> is connected to a fitting portion 9A formed on a roller <NUM> to be revolvable, and accordingly, a suction chamber <NUM> and a compression chamber <NUM> divided by the vane <NUM> can be formed in the cylinder chamber <NUM>.

According to the rotary compressor having the above-described configuration, a volume of each of the suction chamber <NUM> and the compression chamber <NUM> is changed by a revolving motion of the roller <NUM> and a reciprocating motion of the vane <NUM> according to rotation of the shaft <NUM>. Due to the volume change, a refrigerant suctioned into the suction chamber <NUM> through a suction port <NUM> is compressed and thus becomes a high temperature high pressure refrigerant. Like the above, the compressed refrigerant is discharged into the airtight container <NUM> after passing through a discharge port <NUM> and a discharge silencer chamber <NUM> in the compression chamber <NUM>.

In addition, oil can be suctioned into the shaft <NUM> by an oil pump provided on the shaft <NUM>. The suctioned oil is supplied between slide surfaces in the compression mechanism, for example, the eccentric portion 4A of the shaft <NUM> and an inner circumferential surface 9B of the roller <NUM>, and an outer circumferential surface of the roller <NUM> and an inner circumferential surface of the cylinder <NUM> through the hollow provided in the shaft <NUM> to perform lubrication.

However, as shown in <FIG>, in the conventional rotary compressor, when the shaft <NUM> rotates, a rotational moment acts on the roller <NUM> due to the viscosity of the oil interposed between the eccentric portion 4A of the shaft <NUM> and the inner circumferential surface 9B of the roller <NUM>. Like the above, the rotational moment which acts on the roller <NUM> acts in a rotation direction of the shaft <NUM> with respect to the eccentric portion 4A of the shaft <NUM>.

Since the rotational moment is supported by the front end portion 11A of the vane <NUM>, a frictional resistance between the vane <NUM> and the vane groove <NUM> acts on contact points <NUM> and <NUM> of the vane <NUM> and the vane groove <NUM> as a reaction force of the support force. Like the above, due to the acting frictional resistance, a problem occurs that sliding loss, which is generated when the vane <NUM> reciprocates in the vane groove <NUM>, increases.

<CIT> (invention title: A Rotary Compressor) discloses a configuration in which a narrow portion is formed on an inner circumferential surface of a roller as a configuration for solving the problem.

<FIG> is a lateral sectional view illustrating a compression mechanism of the conventional rotary compressor, and <FIG> is a perspective view illustrating a roller shown in <FIG>.

Referring to <FIG> and <FIG>, an inner circumferential surface of the roller <NUM> provided in the conventional rotary compressor includes a broad slide portion 9C and a narrow slide portion 9D.

The broad slide portion 9C is a slide surface facing the eccentric portion 4A of the shaft <NUM> and is a slide surface having a relatively large width in a height direction of the roller <NUM>. Further, the narrow slide portion 9D is a slide surface facing the eccentric portion 4A of the shaft <NUM>, and is a slide surface having a relatively smaller width than the broad slide portion 9C in the height direction of the roller <NUM>.

A contact area between the inner circumferential surface of the roller <NUM> and the shaft <NUM> is formed to be smaller in the narrow slide portion 9D than in the broad slide portion 9C. Accordingly, in the narrow slide portion 9D, a contact area between the outer circumferential surface of the shaft <NUM> and the inner circumferential surface of the roller <NUM> decreases, and a viscous force of the oil proportional to the contact area can be decreased.

Accordingly, the rotational moment which acts in the rotational direction of the shaft <NUM> of the circumferential direction with respect to the eccentric portion 4A of the shaft <NUM> can be decreased. Accordingly, the frictional resistance between the vane <NUM> and the vane groove <NUM> generated when the vane <NUM> reciprocates in the vane groove <NUM> can be reduced, and the sliding loss generated when the vane <NUM> reciprocates in the vane groove <NUM> can be decreased.

However, according to the above-described conventional rotary compressor, the following problems occur.

First, leakage can occur in some types of rotary compressors.

In a rotary compressor of a type in which a plurality of compression mechanisms are vertically connected, a middle plate is disposed between the compression mechanism and the compression mechanism. The insides of the compression mechanisms can be divided by the middle plate.

In the above-described type rotary compressor, a refrigerant may be introduced into the insides of the compression mechanisms through the inside of the middle plate. That is, a suction port can be provided in the middle plate, and the refrigerant introduced through the suction port can be introduced into suction chambers of the compression mechanisms through an intake formed in the middle plate.

In this case, the intake formed in the middle plate can be disposed at a position vertically overlapping the roller <NUM>. For example, when the roller <NUM> which revolves in the cylinder <NUM> is disposed at a position most adjacent to the intake, at least a portion of the roller <NUM> and the intake can be located at a vertically overlapping position.

In this time, a position of the narrow slide portion 9D of the roller <NUM> can vertically overlap the position of the intake, and in this case, a situation that the refrigerant introduced into the suction chamber through the intake leaks to the outside of the suction chamber through a space formed in the narrow slide portion 9D can occur.

According to the conventional rotary compressor, the narrow slide portion 9D is formed in a region biased to a slide surface of the suction chamber <NUM> on the roller <NUM>, more specifically, in a range of <NUM> to <NUM>° in the rotation direction of the shaft <NUM>.

Accordingly, a possibility that the narrow slide portion 9D and the intake vertically overlap increases, and thus, a possibility of leakage of the refrigerant through the narrow slide portion 9D increases.

Secondarily, a portion in the inner circumferential surface of the roller <NUM> which does not come into contact with the eccentric portion 4A of the shaft <NUM> is generated, and accordingly, a surface pressure per unit area received by the roller <NUM> increases.

In the narrow slide portion 9D, contact between the inner circumferential surface of the roller <NUM> and the shaft <NUM> does not occur. Accordingly, an area of the inner circumferential surface of the roller <NUM> which comes into contact with the eccentric portion 4A of the shaft <NUM> decreases, and thus, the surface pressure per unit area received by the roller <NUM> increases.

Thirdly, a problem occurs that lubrication between the shaft <NUM> and the roller <NUM> at the compression chamber <NUM>, which receives the most load from the eccentric portion 4A of the shaft <NUM>, becomes weak.

According to the conventional rotary compressor, the narrow slide portion 9D is formed in a region biased to a slide surface of the suction chamber <NUM> on the roller <NUM> (in a range of <NUM> to <NUM>° in the rotation direction of the shaft <NUM>).

Like the above, in a region where the narrow slide portion 9D is formed on the roller <NUM>, since a space necessary for securing oil can be sufficiently provided, the lubrication between the shaft <NUM> and the roller <NUM> can be smoothly performed.

However, in a region where the narrow slide portion 9D is not formed on the roller <NUM>, that is, a region biased to a slide surface of the compression chamber <NUM> on the roller <NUM>, since it is difficult to sufficiently provide the space necessary for securing oil, the lubrication between the shaft <NUM> and the roller <NUM> becomes relatively weak.

Fourthly, a problem occurs that difficulty of assembling the roller <NUM> increases and possibility of an assembly error increases.

According to the conventional rotary compressor, the narrow slide portion 9D is formed in a shape in which an upper portion of the inner circumferential surface of the roller <NUM> is partially recessed. That is, in the roller <NUM>, an upper shape and a lower shape are formed in different shapes.

Accordingly, since an assembly work of the roller <NUM> should be performed while distinguishing upper and lower portions of the roller <NUM>, difficulty of the assembly work of the roller <NUM> is increased, and accordingly, possibility of the assembly error is increased.

(Patent Document <NUM>) <CIT>)
<CIT> relates to a rotary compressor allowing to make an eccentric part shaft diameter small without thinning shaft diameters of a main shaft part and an auxiliary shaft part by enlarging eccentricity of the eccentric part of a rotary shaft.

<CIT> relates to a rotary compressor that is incorporated into a refrigerator, an air conditioner or the like.

The present invention is directed to providing a rotary compressor capable of improving the lubrication performance between a shaft and a roller in addition to restraining leakage of a refrigerant through the roller.

Further, the present invention is directed to providing a rotary compressor of which a structure is improved so that the lubrication performance between a shaft and a roller is improved and an increase of a surface pressure per unit area received by the roller is prevented.

In addition, the present invention is directed to providing a rotary compressor of which a structure is improved so that lubrication at a portion which receives a great deal of load from an eccentric portion of a shaft may also be effectively performed.

In addition, the present invention is directed to providing a rotary compressor of which a structure is improved so that assembly of the roller is easy and possibility of an occurrence of an assembly error of the roller decreases.

In a rotary compressor which is one embodiment of the present invention, a roller is provided with oil grooves concavely formed in a centrifugal direction from an inner circumferential surface of the roller facing an eccentric portion, and the oil grooves are disposed at positions not overlapping an intake and a discharge port in an axial direction.

According to this configuration, oil supply between a shaft and the roller may be smoothly performed and an occurrence of leakage of a refrigerant through the oil grooves may be effectively restrained.

Further, in another embodiment of the present invention, oil grooves are concavely formed in an inner circumferential surface of a roller facing an eccentric portion, and the oil grooves are formed in a shape located in a region biased to a slide surface of a compression chamber in addition to a region biased to a slide surface of a suction chamber.

According to this configuration, the lubrication performance of inner components of a compression part may be further improved, and friction loss in the compression part may be further effectively decreased.

Further, in still another embodiment of the present invention, oil grooves are concavely formed in an inner circumferential surface of a roller facing an eccentric portion, and the oil grooves are formed in a region not connected to an intake.

In addition, in yet another embodiment of the present invention, oil grooves are concavely formed in an inner circumferential surface of a roller facing an eccentric portion, and the oil grooves are formed over the entire region in a circumferential direction of the roller except for a region which may be connected to an intake.

In addition, in yet another embodiment of the present invention, oil grooves are concavely formed in an inner circumferential surface of a roller facing an eccentric portion, and the oil grooves are disposed at one side and the other side of the roller in an axial direction.

According to this configuration, the oil grooves may be provided in the roller as long as possible and as many as possible, and thus, a weight of the roller may be reduced.

Further, in yet another embodiment of the present invention, a shape of one side of a roller in an axial direction and a shape of the other side of the roller in the axial direction are the same.

According to this configuration, the roller does not require direction classification according to a vertical direction, and thus the roller may be more easily assembled.

According to an aspect of the present invention, there is provided a rotary compressor including: cylinders each including a compression space; a ring-shaped roller configured to compress a refrigerant in the compression space; a vane connected to the roller and at least partially inserted into a vane slot formed in the cylinders to be linearly movable to divide the compression space into a suction chamber and a compression chamber; an eccentric portion which is rotatably coupled to an inner side in a radial direction of the roller and eccentrically rotates so that the roller revolves; a shaft coupled to an inner side in a radial direction of the eccentric portion to eccentrically rotate the eccentric portion; a first member disposed at one side in an axial direction of each of the cylinders and provided with an intake connected to the suction chamber; and a second member disposed at the other side in the axial direction of each of the cylinders and provided with a discharge port connected to the compression chamber, wherein the roller is provided with oil grooves concavely formed in a centrifugal direction from an inner circumferential surface of the roller facing the eccentric portion, and the oil grooves are disposed at positions not overlapping the intake and the discharge port in an axial direction.

Further, with respect to a first virtual line which connects a rotation center of the shaft and the vane, when an angle between the first virtual line and a second virtual line, which connects the rotation center of the shaft and a point of the intake which is farthest away from the first virtual line is a first angle and an angle between the first virtual line and a third virtual line, which connects the rotation center of the shaft and a point of the discharge port which is farthest away from the first virtual line is a second angle, each of an angle between a fourth virtual line, which connects the rotation center of the shaft and one end in a circumferential direction of the oil groove and the first virtual line and an angle between a fifth virtual line, which connects the rotation center of the shaft and the other end in the circumferential direction of the oil groove and the first virtual line, may be set as a range between the first angle and the second angle.

In addition, the first angle may be <NUM> to <NUM>°, the second angle may be <NUM> to <NUM>°, and each of the angle between the fourth virtual line and the first virtual line and the angle between the fifth virtual line and the first virtual line may be set as a range between <NUM> to <NUM>°.

In addition, in the case in which the first angle is α° and the second angle is β°, when α is greater than or equal to <NUM>°-β°, the angle between the first virtual line and the fourth virtual line may be set as an angle greater than or equal to α° and smaller than <NUM>°- α°, and the angle between the first virtual line and the fifth virtual line may be set as an angle greater than the angle between the first virtual line and the fourth virtual line and smaller than or equal to <NUM>°- α°.

In addition, the oil grooves may be formed to be continuously connected along the circumferential direction in a range of α° to <NUM>°- α°.

In addition, the oil grooves may be symmetrically formed with respect to the first virtual line.

In addition, the oil grooves may be concavely formed toward a center in an axial direction of the roller from an end portion of the roller in the axial direction.

In addition, the oil grooves may be formed to be recessed from the end portion of the roller in the axial direction by a predetermined depth and formed to a depth in which the eccentric portion does not protrude to an outer side in an axial direction of the oil groove.

In addition, the oil grooves may be formed in one side end portion of the roller in the axial direction and the other side end portion of the roller in the axial direction.

In addition, a pair of oil grooves may be symmetrically formed with respect to the center in the axial direction of the roller.

In addition, an oil accommodation space surrounded by the first member and the oil groove or the second member and the oil groove may be formed in each of the oil grooves, and the oil accommodation space may be connected to a gap between the inner circumferential surface of the roller and an outer circumferential surface of the eccentric portion.

In addition, each of the oil grooves may be formed in a C shape of which both end portions in a circumferential direction are disposed to be spaced apart from each other.

In addition, the first member may be a middle plate configured to cover one side of the cylinder in an axial direction, and the second member may be a bearing configured to cover the other side of the cylinder in the axial direction.

Hereinafter, embodiments of a rotary compressor according to the present invention will be described with reference to the accompanying drawings. Thicknesses of lines, sizes of components, or the like shown in the drawings may be shown to be exaggerated for clarity and convenience of the description. Further, terms which will be described later are terms defined in consideration of functions in the present disclosure and may be various according to purposes or conventions of an operator or a user. Accordingly, the terms should be defined on the basis of the content throughout the specification.

<FIG> is a longitudinal sectional view schematically illustrating a structure of the rotary compressor according to one embodiment of the present invention, <FIG> is a cross-sectional view illustrating a compression part of the rotary compressor shown in <FIG> in a separated state, and <FIG> is a perspective view illustrating some components of the compression part shown in <FIG> in a separated state.

Referring to <FIG> and <FIG>, a rotary compressor <NUM> according to a first embodiment of the present invention may include a case <NUM>, a driving part <NUM>, and a compression part <NUM>.

The case <NUM> forms an exterior of the rotary compressor <NUM>. In the case <NUM>, an inner space which accommodates the driving part <NUM> and the compression part <NUM> may be formed. As an example, the case <NUM> may be formed in a cylindrical shape having a length extending along an axial direction.

The case <NUM> may include an upper shell <NUM>, a middle shell <NUM>, and a lower shell <NUM>. The driving part <NUM> and the compression part <NUM> may be fixed to the inside of the middle shell <NUM>. Further, the upper shell <NUM> and the lower shell <NUM> may be respectively disposed on and under the middle shell <NUM>. The upper shell <NUM> and the lower shell <NUM> restrict exposure of components disposed in the case <NUM>.

The driving part <NUM> may be accommodated in the inner space of the case <NUM> and disposed on the compression part <NUM>. The driving part <NUM> serves to provide power for compressing a refrigerant and may include a motor <NUM> and a shaft <NUM>.

The motor <NUM> may include a stator <NUM> and a rotor <NUM>. The stator <NUM> may be fixed to the inside of the case <NUM> and, more specifically, to the inside of the middle shell <NUM>. The rotor <NUM> may be disposed to be spaced apart from the stator <NUM>, and may be disposed at an inner side of a radial direction of the stator <NUM>.

When power is applied to the stator <NUM>, the rotor <NUM> rotates due to a force generated by a magnetic field formed between the stator <NUM> and the rotor <NUM>. As described above, the rotating rotor <NUM> transfers a rotational force to the shaft <NUM> passing through a center of the rotor <NUM>.

The shaft <NUM> is rotated by the rotor <NUM> and may be connected to a roller <NUM> of the compression part <NUM> which will be described later. The shaft <NUM> may provide power for compressing the refrigerant by providing power to the roller <NUM> for revolution the roller <NUM>.

Further, a suction port <NUM> may be provided at one side of the middle shell <NUM>, and a discharge pipe <NUM> may be connected to one side of the upper shell <NUM>. The suction port <NUM> may be connected to a suction pipe <NUM> connected to an evaporator, and the discharge pipe <NUM> may be connected to a condenser.

Referring to <FIG>, the compression part <NUM> may include cylinders <NUM> and <NUM>, a first bearing <NUM>, a second bearing <NUM>, a roller <NUM>, and a vane <NUM>.

Each of the cylinders <NUM> and <NUM> are formed in a ring shape. In each of the cylinders <NUM> and <NUM>, a compression space in which the refrigerant is compressed may be formed. The inside of each of the cylinders <NUM> and <NUM> may be formed so that passing therethrough in an axial direction is possible.

In the embodiment, an example in which the compression part <NUM> includes two cylinders <NUM> and <NUM> is described. Accordingly, the compression part <NUM> may include a first cylinder <NUM> and a second cylinder <NUM>. The first cylinder <NUM> and the second cylinder <NUM> may be arranged in the axial direction. That is, the first cylinder <NUM> is disposed at one side in the axial direction of the second cylinder <NUM> (hereinafter, referred to as "an upper side"), and the second cylinder <NUM> is disposed at the other side in the axial direction of the first cylinder <NUM> (hereinafter, referred to as "a lower side").

The first bearing <NUM> may be disposed on the first cylinder <NUM>, and the second cylinder <NUM> may be disposed under the first cylinder <NUM>. In this case, a middle plate <NUM> may be disposed between the first cylinder <NUM> and the second cylinder <NUM>.

Further, the middle plate <NUM> may be disposed on the second cylinder <NUM>, and the second bearing <NUM> may be disposed under the second cylinder <NUM>.

The first bearing <NUM> and the second bearing <NUM> are respectively disposed on the first cylinder <NUM> and under the second cylinder <NUM>, and the shaft <NUM> which passes through the first cylinder <NUM> and the second cylinder <NUM> may be rotatably supported. Further, the middle plate <NUM> is disposed between the first cylinder <NUM> and the second cylinder <NUM> to partition a space in the first cylinder <NUM> and a space in the second cylinder <NUM>.

An upper portion of the space formed in the first cylinder <NUM> may be sealed by the first bearing <NUM>. Further, a lower portion of the space formed in the first cylinder <NUM> may be sealed by the middle plate <NUM>. As described above, the compression space may be formed in the first cylinder <NUM> sealed by the first bearing <NUM> and the middle plate <NUM>.

Further, an upper portion of the space formed in the second cylinder <NUM> may be sealed by the middle plate <NUM>. In addition, a lower portion of the space formed in the second cylinder <NUM> may be sealed by the second bearing <NUM>. As described above, the compression space may be formed in the second cylinder <NUM> sealed by the middle plate <NUM> and the second bearing <NUM>.

The roller <NUM> and the vane <NUM> may be respectively disposed in the compression spaces of the cylinders <NUM> and <NUM>.

The roller <NUM> may be coupled to the shaft <NUM> and rotatably coupled to the eccentric portion <NUM> eccentrically protruding from the shaft <NUM>. The roller <NUM> may be formed in a ring shape, and the eccentric portion <NUM> may be rotatably coupled to an inner circumferential surface of the roller <NUM>. The roller <NUM> may revolve due to the eccentric portion <NUM> when the shaft <NUM> rotates. In this case, the roller <NUM> may revolve in the cylinders <NUM> and <NUM> while coming into contact with inner circumferential surfaces of the cylinders <NUM> and <NUM>.

The eccentric portion <NUM> is coupled to the shaft <NUM> and is coupled to an outer side in a radial direction of the shaft <NUM>. The eccentric portion <NUM> is eccentrically coupled to the shaft <NUM> and may be rotatably coupled to an inner side in a radial direction of the roller <NUM>, that is, the inner circumferential surface of the roller <NUM>. Like the above, the eccentric portion <NUM> coupled to the inner circumferential surface of the roller <NUM> may be eccentrically rotated by the shaft <NUM> so that the roller <NUM> may revolve.

The vane <NUM> has one side coupled to the roller <NUM> and divides the compression space into a suction chamber and a compression chamber. The vane <NUM> may be inserted into a vane slot <NUM> provided in each of the cylinders <NUM> and <NUM>.

According to the embodiment, the vane slot <NUM> is formed to pass through each of the cylinders <NUM> and <NUM> in a radial direction and forms a straight path in each of the cylinders <NUM> and <NUM>. The vane <NUM> is provided to be capable of reciprocating in a linear direction in the vane slots <NUM> formed as described above.

Further, a hinge head <NUM> may be provided at one side of the vane <NUM>, and the hinge head <NUM> may be coupled to a roller groove <NUM> provided in an outer circumferential surface of the roller <NUM>.

The hinge head <NUM> is formed to protrude toward one side in the radial direction from the vane <NUM> and may be formed in a round shape. Further, the roller groove <NUM> may be formed in a round groove shape corresponding to a shape of the hinge head <NUM>. Since the hinge head <NUM> is fit-coupled to the roller groove <NUM>, coupling of the roller <NUM> and the vane <NUM> may be maintained even during a revolving process of the roller <NUM>.

In the embodiment, the vane <NUM> is illustrated as being formed of an SUJ2 steel material. SUJ2 steel is steel widely used as bearing steel and is a material which is easy to process and shape and has high impact resistance and high wear resistance. The SUJ2 steel is suitable as a material for manufacturing the vane <NUM> which should be repeatedly moved under a high pressure in the compression space.

In the compression part <NUM>, with respect to the vane <NUM>, the suction chamber is located at a left portion of the vane <NUM>, and the compression chamber is located at a right portion of the vane <NUM>. That is, the vane <NUM> may be coupled to the roller <NUM> to divide the compression space in each of the cylinders <NUM> and <NUM> into the suction chamber and the compression chamber.

An intake <NUM> and a discharge port <NUM> may be respectively connected to the suction chamber and the compression chamber which are divided. The refrigerant supplied through the suction port <NUM> may be introduced into the suction chamber through the intake <NUM>. Further, the refrigerant compressed in the compression chamber may be discharged to the outside of the compression part <NUM> through the discharge port <NUM> and then discharged to the outside of the rotary compressor <NUM> through the discharge pipe <NUM>.

According to the embodiment, a lower region of the case <NUM> may be filled with oil. The oil may move in an upward direction through a hollow <NUM> in the shaft <NUM> and may be transferred to the compression part <NUM>.

The shaft <NUM> may be provided with an oil discharge hole <NUM>. The oil discharge hole <NUM> may be formed to pass through the shaft <NUM> in the radial direction. The oil discharge hole <NUM> may be disposed in the compression part <NUM>, more specifically, in the compression space of each of the cylinders <NUM> and <NUM>.

The oil discharged through the oil discharge hole <NUM> may be supplied between the outer circumferential surface of the eccentric portion <NUM> and the inner circumferential surface of the roller <NUM>, and between an outer circumferential surface of the roller <NUM> and an inner circumferential surface of each of the cylinders <NUM> and <NUM>. Like the above, the oil supplied through the oil discharge hole <NUM> may perform lubrication between the outer circumferential surface of the eccentric portion <NUM> and the inner circumferential surface of the roller <NUM> and perform lubrication between the outer circumferential surface of the roller <NUM> and the inner circumferential surface of each of the cylinders <NUM> and <NUM>.

As an example, the shaft <NUM> is provided with an oil pump, and the oil which fills the lower region of the case <NUM> may be suctioned into the hollow <NUM> in the shaft <NUM> through the oil pump.

As another example, the oil which fills the lower region of the case <NUM> may be suctioned into the hollow <NUM> in the shaft <NUM> by a pressure difference. Since a pressure of the inside of the compression part <NUM> is relatively lower than a pressure of the outside of the compression part <NUM>, oil at the outside of the compression part <NUM> may be suctioned into the hollow <NUM> in the shaft <NUM> and transferred to the inside of the compression part <NUM> through the oil discharge hole <NUM>.

Hereinafter, the structure of the compression part will be described in detail with reference to <FIG>. For convenience of the description, here, a surrounding structure of the first cylinder will be representatively described.

However, it is noted that the structure exemplified in the embodiment may be applied to not only the first cylinder but also the second cylinder.

As described above, the compression space may be formed in the first cylinder <NUM>. In the compression space, the roller <NUM> may be disposed. The eccentric portion <NUM> may be fit-coupled to the inner circumferential surface of the roller <NUM>. The eccentric portion <NUM> may be provided in a shape protruding in a centrifugal direction from the shaft <NUM> which passes through an inner side in the radial direction of the roller <NUM>.

When the shaft <NUM> rotates, the eccentric portion <NUM> is rotated due to rotation of the shaft <NUM>, and the eccentric portion <NUM> is eccentrically rotated in the roller <NUM> so that the roller <NUM> revolves.

Further, a first member may be disposed at one side in the axial direction of the first cylinder <NUM>, that is, an upper side, and a second member may be disposed at the other side in the axial direction of the cylinder <NUM>, that is, a lower side. The first member may cover an upper portion of the first cylinder <NUM>, and the second member may cover a lower portion of the second cylinder <NUM>.

Accordingly, a space of which an upper portion is blocked by the first member and a lower portion is blocked by the second member, that is, the compression space, may be formed in the first cylinder <NUM>.

According to the embodiment, the first member disposed at the one side in the axial direction of the first cylinder <NUM> may be the first bearing <NUM> which covers the upper portion of the first cylinder <NUM>. Further, the second member disposed at the other side in the axial direction of the first cylinder <NUM> may be the middle plate <NUM> which covers the lower portion of the first cylinder <NUM>.

As another example, with respect to the second cylinder <NUM> disposed under the first cylinder <NUM>, the first member disposed at one side in the axial direction of the second cylinder <NUM> may be the middle plate <NUM> which covers the upper portion of the second cylinder <NUM>. Further, the second member disposed at the other side in the axial direction of the second cylinder <NUM> may be the second bearing <NUM> which covers the lower portion of the second cylinder <NUM>.

As still another example, when the compression part <NUM> is formed as one cylinder, the first member may be the first bearing <NUM> which covers the upper portion of the first cylinder <NUM> or second cylinder <NUM>, and the second member may be the second bearing <NUM> which covers the lower portion of the first cylinder <NUM> or second cylinder <NUM>.

Hereinafter, an example in which the first bearing <NUM> is disposed on the first cylinder <NUM> and the middle plate <NUM> is disposed under the first cylinder <NUM> is described.

In the embodiment, an example in which the middle plate <NUM> is connected to the suction port <NUM> is described. In the middle plate <NUM>, a refrigerant flow path <NUM> connected to the suction port <NUM> may be formed.

The refrigerant flow path <NUM> may be opened to the outside of the middle plate <NUM> through an outer circumferential surface of the middle plate <NUM>. The refrigerant flow path <NUM> may be connected to the suction port <NUM> through an inlet side of the refrigerant flow path <NUM> which is thus opened.

The refrigerant flow path <NUM> may extend in a centripetal direction from the outer circumferential surface of the middle plate <NUM>. An outlet side of the refrigerant flow path <NUM> may be bifurcated. One of the bifurcated outlets may be connected to the compression space in the first cylinder <NUM> through an upper surface of the middle plate <NUM>. Further, the other one of the bifurcated outlets may be connected to the compression space in the first cylinder <NUM> through a lower surface of the middle plate <NUM>.

Among the above, the outlet side of the refrigerant flow path <NUM> connected to the compression space in the first cylinder <NUM> through the upper surface of the middle plate <NUM> may be defined as the intake <NUM> disposed in the compression space in the first cylinder <NUM>.

According to the embodiment, the middle plate <NUM> may be disposed under the compression space formed in the first cylinder <NUM>. Further, the intake <NUM> formed on the middle plate <NUM> may also be disposed under the compression space.

At least a portion of the intake <NUM> may overlap a moving path of the roller <NUM> which revolves in the compression space. That is, the roller <NUM> which compresses the refrigerant by revolving in the compression space may pass through a position overlapping the intake <NUM> in the axial direction while moving.

Further, the first bearing <NUM> may be disposed on the compression space formed in the first cylinder <NUM>. In addition, the first bearing <NUM> may be provided with the discharge port <NUM>. The discharge port <NUM> may be formed to pass through the first bearing <NUM> in the axial direction, and the discharge port <NUM> may be disposed above the compression space.

At least a portion of the discharge port <NUM> may overlap the moving path of the roller <NUM> which revolves in the compression space. That is, the roller <NUM> which compresses the refrigerant by revolving in the compression space may pass through a position overlapping the discharge port <NUM> in the axial direction while moving.

With respect to the vane <NUM>, the intake <NUM> may be disposed at the left portion of the vane <NUM>, that is, the suction chamber, and the discharge port <NUM> may be disposed at the right portion of the vane <NUM>, that is, the compression chamber. In this case, the intake <NUM> and the discharge port <NUM> may be disposed adjacent to the vane <NUM>.

In the embodiment, with respect to a rotation center of the shaft <NUM>, an example in which the intake <NUM> and the vane <NUM> are disposed to form an angle within <NUM>° and the vane <NUM> and the discharge port <NUM> are disposed to form an angle within <NUM>° is described.

<FIG> is an enlarged view illustrating portion IX in <FIG>, <FIG> is a cross-sectional view taken along line X-X in <FIG>, and <FIG> is a lateral sectional view illustrating some components of the compression part shown in <FIG>.

Hereinafter, the structure of the roller will be described in detail with reference to <FIG>. For convenience of the description, here, the structure of the roller installed in the first cylinder will be representatively described.

Referring to <FIG>, the roller <NUM> may be provided with oil grooves <NUM>. The oil grooves <NUM> may be formed in the inner circumferential surface of the roller <NUM> facing the eccentric portion <NUM>. The oil grooves <NUM> may be concavely formed in a centrifugal direction from the inner circumferential surface of the roller <NUM>.

Further, the oil grooves <NUM> may be formed to be recessed from the end portion of the roller <NUM> in the axial direction by a predetermined depth. That is, the oil grooves <NUM> may be formed in an edge of the inner circumferential surface of the roller <NUM>, concavely formed in the centrifugal direction from the inner circumferential surface of the roller <NUM>, and concavely formed toward a center of the roller <NUM> in the axial direction from the end portion of the roller <NUM> in the axial direction.

The oil groove <NUM> may be formed in each of one side end portion of the roller <NUM> in the axial direction (hereinafter, referred to as an "upper end portion of the roller") and the other side end portion of the roller <NUM> in the axial direction (hereinafter, referred to as a "lower end portion of the roller"). That is, the roller <NUM> may be provided with a pair of oil grooves <NUM>.

Referring to <FIG>, the pair of oil grooves <NUM> may be symmetrically formed with respect to the center of the roller <NUM> in the axial direction. According to the roller <NUM> having the pair of oil grooves <NUM>, a shape of one side surface of the roller <NUM> in the axial direction and a shape of the other side surface of the roller <NUM> in the axial direction may be symmetrically formed with respect to the center of the roller <NUM> in the axial direction. That is, the shape of the one side surface of the roller <NUM> in the axial direction and the shape of the other side surface of the roller <NUM> in the axial direction are the same.

The roller <NUM> does not require direction classification according to a vertical direction. Accordingly, when the roller <NUM> is installed between the eccentric portion <NUM> and the first cylinder <NUM>, an installing direction of the roller <NUM> does not have to be considered. Accordingly, even when the roller <NUM> is provided with the oil grooves <NUM>, the roller <NUM> may be easily assembled, and an occurrence of an assembly error through a process of assembling the roller <NUM> may significantly decrease.

Further, the oil groove <NUM> may be formed to a depth in which the eccentric portion <NUM> does not protrude to an outer side of an axial direction of the oil groove <NUM>. Accordingly, the oil groove <NUM> disposed at an upper portion may be formed so that an upper end portion of the eccentric portion <NUM> coupled to the roller <NUM> may be formed not to protrude to an upper portion of the oil groove <NUM>, and the oil groove <NUM> disposed at a lower portion may be formed so that a lower end portion of the eccentric portion <NUM> coupled to the roller <NUM> may be formed not to protrude to a lower portion of the oil groove <NUM>.

That is, no portion of the outer circumferential surface of the eccentric portion <NUM> protrudes to an outer side of the inner circumferential surface of the roller <NUM>. Accordingly, between the eccentric portion <NUM> and the roller <NUM>, a state in which the outer circumferential surface of the eccentric portion <NUM> is entirely engaged with the inner circumferential surface of the roller <NUM> may be maintained.

Accordingly, a force applied to the outer circumferential surface of the eccentric portion <NUM> during a revolving process of the roller <NUM> may act not on a portion of the outer circumferential surface of the eccentric portion <NUM> but on the entire outer circumferential surface of the eccentric portion <NUM>. Accordingly, since an area of the outer circumferential surface of the eccentric portion <NUM> which receives the force applied to the eccentric portion <NUM> may increase, a surface pressure per unit area received by the eccentric portion <NUM> may effectively decrease.

Referring to <FIG> and <FIG>, an oil accommodation space <NUM> may be formed in each of the oil grooves <NUM> formed like the above. The oil accommodation space <NUM> is a space surrounded by the first member and the oil groove <NUM> or a space surrounded by the second member and the oil groove <NUM>.

For example, the oil accommodation space <NUM> surrounded by the first bearing <NUM> and the oil groove <NUM> may be formed in one side of the roller <NUM> facing the first member. Further, the oil accommodation space <NUM> surrounded by the middle plate <NUM> and the oil groove <NUM> may be formed in the other side of the roller <NUM> facing the second member.

Each of the oil accommodation spaces <NUM> formed in this way may be connected to a gap between the inner circumferential surface of the roller <NUM> and the outer circumferential surface of the eccentric portion <NUM>. In the oil accommodation space <NUM>, oil which moves through the hollow <NUM> in the shaft <NUM> may be filled.

As an example, the oil which moves through the hollow <NUM> in the shaft <NUM> may be discharged to the outside of the shaft <NUM> through the oil discharge hole <NUM>. As described above, the oil discharged to the outside of the shaft <NUM> may be supplied to the oil accommodation space <NUM>.

The oil supplied to the oil accommodation space <NUM> may be supplied to a gap connected to the oil accommodation space <NUM>, that is, the gap between the inner circumferential surface of the roller <NUM> and the outer circumferential surface of the eccentric portion <NUM>.

The oil which is supplied like the above may perform the lubrication between the outer circumferential surface of the eccentric portion <NUM> and the inner circumferential surface of the roller <NUM> and perform the lubrication between the outer circumferential surface of the roller <NUM> and the inner circumferential surface of each of the cylinders <NUM> and <NUM>.

The oil accommodation space <NUM> may provide not only a path necessary to supply the oil discharged through the oil discharge hole <NUM> to the gap between the inner circumferential surface of the roller <NUM> and the outer circumferential surface of the eccentric portion <NUM> (hereinafter, referred to as "a sliding portion"), but also a storage space necessary to fill the roller <NUM> with a predetermined amount of oil.

That is, some of the oil introduced into the oil accommodation space <NUM> may be supplied to the sliding portion, and the remaining oil may fill the oil accommodation space <NUM>. Further, the oil which fills the oil accommodation space <NUM> like the above may be supplied continuously little by little to the sliding portion.

When a state in which the oil receiving space <NUM> is filled with oil of a predetermined amount or more is maintained, the oil may be supplied from an entire region surrounded by the oil accommodation space <NUM> as well as a partial region of the outer circumferential surface of the eccentric portion <NUM> to the sliding portion.

Further, when the state in which the oil receiving space <NUM> is filled with oil of the predetermined amount or more is maintained, a self-weight of the oil filled in the oil accommodation space <NUM> may act as a force which introduces the oil into the sliding portion.

Accordingly, the oil may be stably supplied to the sliding portion, and oil supply to the sliding portion may be more smoothly performed from a relatively broader region. Accordingly, since a lubrication performance to components in the compression part <NUM> may be improved, and friction loss in the compression part <NUM> may decrease, operation reliability and operation efficiency of the rotary compressor may be further improved.

<FIG> is a view for describing a shape of the oil groove shown in <FIG>.

Hereinafter, a specific shape of the oil groove will be described in detail with reference to <FIG>.

Terms will be defined. A first virtual line L1 is a virtual line which connects a rotation center O of the shaft <NUM> and the vane <NUM> in a radial direction. A second virtual line L2 is a virtual line which connects the rotation center O of the shaft <NUM> and the intake <NUM> and connects a point of the intake <NUM> which is farthest away from the first virtual line L1 and the rotation center O of the shaft <NUM>. A third virtual line L3 is a virtual line which connects the rotation center O of the shaft <NUM> and the discharge port <NUM> in a radial direction and connects a point of the discharge port <NUM> which is farthest away from the first virtual line L1 and the rotation center O of the shaft <NUM>.

Further, a first angle (α) is an angle between the first virtual line L1 and the second virtual line L2 with respect to the first virtual line L1, and a second angle (β) is an angle between the first virtual line L1 and the third virtual line L3 with respect to the first virtual line L1. In this case, the angle is measured in a counterclockwise direction.

Further, a fourth virtual line L4 is a virtual line which connects the rotation center O of the shaft <NUM> and one end of a circumferential direction of the oil grooves <NUM>. A fifth virtual line L5 is a virtual line which connects the rotation center O of the shaft <NUM> and the other end of the circumferential direction of the oil grooves <NUM>.

Further, a third angle (γ) is an angle between the first virtual line L1 and the fourth virtual line L4 with respect to the first virtual line L1, and a fourth angle (δ) is an angle between the first virtual line L1 and the fifth virtual line L5 with respect to the first virtual line L1.

According to the embodiment, each of the third angle (γ) and the fourth angle (δ) may be set as a range between the first angle (α) and the second angle (β). That is, a forming range of the oil groove <NUM> according to the circumferential direction may be set as the range between the first angle (α) and the second angle (β).

In the embodiment, an example in which the first angle is (α) is <NUM> to <NUM>°, and the second angle (β) is <NUM> to <NUM>° is described. That is, in the embodiment, an example in which the intake <NUM> is disposed in a region forming an angle in a range of <NUM> to <NUM>° with the vane <NUM>, and the discharge port <NUM> is disposed in a region forming an angle in a range of <NUM> to <NUM>° with the vane <NUM> is described.

In consideration of arrangement positions of the intake <NUM> and the discharge port <NUM>, the third angle (γ) may be set as a range between the first angle (α) and the second angle (β), and the fourth angle (δ) may also be set as a range between the first angle (α) and the second angle (β).

For example, when the first angle (α) is <NUM>° and the second angle (β) is <NUM>°, each of the third angle (γ) and the fourth angle (δ) may be determined as being in a range between <NUM>° to <NUM>°.

In this case, the fourth angle (δ) is determined as an angle greater than the third angle (γ). A difference between the third angle (γ) and the fourth angle (δ) may indicate a length of the circumferential direction of the oil groove <NUM>, and accordingly, it may be understood that the length of the circumferential direction of the oil groove <NUM> increases when the difference between the third angle (γ) and the fourth angle (δ) is large.

In summary, the oil groove <NUM> is formed in the inner circumferential surface of the roller <NUM> in the circumferential direction and is formed in a shape which may not overlap the intake <NUM> and the discharge port <NUM> in the axial direction. For example, the oil groove <NUM> may be formed in a C shape of which both end portions in the circumferential direction are disposed to be spaced apart from each other.

According to the embodiment, the roller <NUM> which compresses the refrigerant by revolving in the compression space may pass through the position overlapping the intake <NUM> in the axial direction and the position overlapping the discharge port <NUM> in the axial direction while moving.

The oil grooves <NUM> exemplified in the embodiment may be formed not to overlap the intake <NUM> and the discharge port <NUM> in the axial direction despite the movement of the above-described roller <NUM>.

To this end, the inside of the compression space is divided in the circumferential direction and may be divided into an arrangement region of the intake <NUM> and the discharge port <NUM> and an arrangement region of the oil grooves <NUM>. Accordingly, a region between the second virtual line L2 and the third virtual line L3 (an inner angle region) may be divided as the arrangement region of the intake <NUM> and the discharge port <NUM>, and a region between the fourth virtual line L4 and the fifth virtual line L5 (an outer angle region) may be divided as the arrangement region of the oil grooves <NUM>.

Accordingly, the shape and length of the oil groove <NUM> may be set so that any portion of the oil groove <NUM> is not located at the arrangement region of the intake <NUM> and the discharge port <NUM>. Accordingly, the oil groove <NUM> may be formed not to overlap the intake <NUM> and discharge port <NUM> in the axial direction.

Further, the oil grooves <NUM> may be symmetrically formed with respect to the first virtual line L1. Generally, considering that the intake <NUM> is formed to be greater than the discharge port <NUM>, the shape and length of the oil groove <NUM> may be mainly influenced by the size of the intake <NUM>.

When the above is expressed as a formula, in the case in which α is greater than or equal to <NUM>-β, it is expressed that γ is greater than or equal to α and is smaller than <NUM>-α, and δ is greater than α and is smaller than or equal to <NUM>-α.

In this case, the oil grooves <NUM> may be formed to be continuously connected along the circumferential direction in a range of α° to <NUM>°- α°.

When the discharge port <NUM> is formed to be greater than the intake <NUM>, that is, when α is smaller than or equal to <NUM>-β, it may be expressed that γ is greater than or equal to β and is smaller than <NUM>- β, and δ is greater than β and is smaller than or equal to <NUM>- β.

Like the above, when the oil grooves <NUM> are formed in a laterally symmetrical shape, the roller <NUM> may also be formed in a laterally symmetrical shape. The roller <NUM> does not require direction classification according to the lateral direction and the vertical direction. Accordingly, when the roller <NUM> is installed between the eccentric portion <NUM> and the first cylinder <NUM>, an installing direction of the roller <NUM> does not have to be considered.

Accordingly, not only an effect that the roller <NUM> may be easily assembled, and the assembly error in the process of assembling the roller <NUM> may significantly decrease, but also an effect that the roller <NUM> is compatible with various types of rotary compressors having different positions, sizes, and shapes of the intake <NUM> and the discharge port <NUM> may be provided.

Referring to <FIG> and <FIG>, the roller <NUM> is provided with the oil grooves <NUM>, and the oil groove <NUM> is formed in a shape not overlapping the intake <NUM> and the discharge port <NUM> in the axial direction.

According to the embodiment, the intake <NUM> is disposed in a region corresponding to the first angle (α) in the compression space (hereinafter, referred to as "an arrangement region of the intake"), and the discharge port <NUM> is disposed in a region corresponding to the second angle (β) in the compression space (hereinafter, referred to as "an arrangement region of the discharge port"). That is, the intake <NUM> is disposed in a range corresponding to <NUM> to <NUM>° in the compression space, and the discharge port <NUM> is disposed in a range corresponding to <NUM> to <NUM>° in the compression space.

Further, the oil grooves <NUM> are formed to be located in a region in the compression space other than the regions corresponding to the first angle (α) and the second angle (β), that is, the arrangement regions of the intake and the discharge port. That is, the oil grooves <NUM> may be formed in the compression space to be located in in a range corresponding to <NUM> to <NUM>°.

According to the embodiment, the roller <NUM> which compresses the refrigerant by revolving in the compression space may pass through the position overlapping the intake <NUM> in the axial direction while moving. However, even when the roller <NUM> and the intake <NUM> are located at the position overlapping each other in the axial direction or the roller <NUM> and the discharge port <NUM> are located at the position overlapping each other in the axial direction, the oil grooves <NUM> do not overlap the intake <NUM> or the discharge port <NUM> in the axial direction.

The above is a result of a geometric design of the oil groove <NUM> intended to prevent the oil grooves <NUM> from overlapping the intake <NUM> and the discharge port <NUM> in the axial direction regardless of the position of the roller <NUM>.

Accordingly, since connection between the oil groove <NUM> and the intake <NUM>, and connection between the oil groove <NUM> and the discharge port <NUM> become difficult, leakage of a refrigerant through the oil grooves <NUM> may be effectively restrained
Further, the above-described oil grooves <NUM> are not formed in only a region biased to a slide surface of the suction chamber or only a region biased to a slide surface of the compression chamber on the roller <NUM>. In the embodiment, the oil grooves <NUM> may be formed on the roller <NUM> to be located in most of the remaining region other than the arrangement region of the intake and the arrangement region of the discharge port.

That is, the oil grooves <NUM> may be formed in a region including both the region biased to the slide surface of the suction chamber and the region biased to the slide surface of the compression chamber. Accordingly, the oil may be sufficiently supplied not to a partial region of the sliding portion but to most of the region of the sliding portion.

In the conventional rotary compressor, the narrow slide portion 9D is formed in only a region biased to the slide surface of the suction chamber, and accordingly, there was a problem in that lubrication between the shaft <NUM> and the roller <NUM> in the compression chamber <NUM> which receives the most load from the eccentric portion 4A of the shaft <NUM> becomes weak (see <FIG>).

On the other hand, in the rotary compressor of the embodiment, the oil grooves <NUM> are formed over most areas other than some areas corresponding to the arrangement regions of the intake and the discharge port. Accordingly, a space required to secure oil can be sufficiently provided over most areas of the roller <NUM>.

Accordingly, the oil may be stably supplied to the sliding portion, and the oil supply to the sliding portion may be more smoothly performed from the relatively broader region. Accordingly, since the lubrication performance to the components in the compression part <NUM> may be improved and the friction loss in the compression part <NUM> may decrease, the operation reliability and the operation efficiency of the rotary compressor may be further improved.

Meanwhile, the oil groove <NUM> may be formed to the depth in which the eccentric portion <NUM> does not protrude to the outer side of the axial direction of the oil groove <NUM>. That is, no portion of the outer circumferential surface of the eccentric portion <NUM> protrudes to the outer side of the inner circumferential surface of the roller <NUM>. Accordingly, the state in which the outer circumferential surface of the eccentric portion <NUM> is entirely engaged with the inner circumferential surface of the roller <NUM> may be maintained.

Accordingly, since the surface pressure per unit area received by the eccentric portion <NUM> may effectively decrease, structural stability of the rotary compressor may be further improved.

Further, the pair of oil grooves <NUM> may be symmetrically formed in the roller <NUM> with respect to the center of the axial direction of the roller <NUM>. The roller <NUM> does not require the direction classification according to the vertical direction.

Accordingly, even when the roller <NUM> is provided with the oil grooves <NUM>, an effect may be provided that the roller <NUM> may be easily assembled, and an assembly error in the process of assembling the roller <NUM> is significantly decreased.

Further, the oil groove <NUM> is formed to a maximum length in the roller <NUM> within a range which allows leakage occurrence of the refrigerant to be minimized. In addition, the oil groove <NUM> is formed in not only the one side but also the other side in the axial direction of the roller <NUM>. That is, the oil grooves <NUM> may be provided in the roller <NUM> as long as possible and as many as possible.

Accordingly, a weight of the roller <NUM> may be reduced by a volume occupied by the oil grooves <NUM>. Like the above, since the weight of the roller <NUM> is reduced, a load necessary for revolution of the roller <NUM> may be reduced, and accordingly, an effect that efficiency of the rotary compressor is improved may be provided.

According to a rotary compressor of the present invention, since oil supply between a shaft and a roller is smoothly performed through oil grooves formed in the roller and the oil grooves are not connected to an intake and a discharge port, an effect is provided that a lubrication performance between the shaft and the roller can be improved and leakage of a refrigerant through the oil grooves can be effectively restrained.

Further, in the present invention, the oil grooves are formed in the roller so that any portion of an outer circumferential surface of an eccentric portion does not protrude to an outer side of an inner circumferential surface of the roller, and accordingly, a state in which the outer circumferential surface of the eccentric portion is entirely engaged with the inner circumferential surface of the roller can be maintained.

Accordingly, in the present invention, since a surface pressure per unit area received by the eccentric portion effectively decreases, structural stability of the rotary compressor can be further improved.

Further, according to the present invention, the oil grooves are formed over most areas other than some areas corresponding to arrangement regions of the intake and the discharge port, and accordingly, a space required to secure oil can be sufficiently provided over most areas of the roller.

Accordingly, in the present invention, since a lubrication performance of inner components of a compression part can be improved and friction loss in the compression part can decrease, a rotary compressor with improved operation reliability and operation efficiency can be provided.

Further, according to the present invention, a pair of oil grooves are symmetrically formed in the roller with respect to the center in an axial direction of the roller, and the roller does not requires direction classification according to a vertical direction.

Accordingly, in the present invention, even when the oil grooves are provided in the roller, an effect that the roller can be easily assembled, and an assembly error in a process of assembling the roller significantly decreases can be provided.

Further, in the present invention, the oil grooves can be provided in the roller as long as possible and as many as possible, and accordingly, a weight of the roller can be reduced, and thus a rotary compressor of which efficiency is further improved can be provided.

Claim 1:
A rotary compressor (<NUM>) comprising:
a cylinder (<NUM>) including a compression space;
a ring-shaped roller (<NUM>) configured to compress a refrigerant in the compression space;
a vane (<NUM>) connected to the roller (<NUM>) and at least partially inserted into a vane slot (<NUM>) formed in the cylinder (<NUM>) to be linearly movable to divide the compression space into a suction chamber and a compression chamber;
an eccentric portion (<NUM>) which is rotatably coupled to an inner side in a radial direction of the roller (<NUM>) and eccentrically rotates so that the roller (<NUM>) revolves;
a shaft (<NUM>) coupled to an inner side in a radial direction of the eccentric portion (<NUM>) to eccentrically rotate the eccentric portion (<NUM>);
a first member disposed at one side in an axial direction of the cylinder (<NUM>) and provided with an intake (<NUM>) connected to the suction chamber; and
a second member disposed at the other side in the axial direction of the cylinder (<NUM>) and provided with a discharge port (<NUM>) connected to the compression chamber,
wherein the roller (<NUM>) is provided with oil grooves (<NUM>) concavely formed in a centrifugal direction from an inner circumferential surface of the roller (<NUM>) facing the eccentric portion (<NUM>), and
the oil grooves (<NUM>) are disposed at positions not overlapping the intake (<NUM>) and the discharge port (<NUM>) in an axial direction.