Patent Description:
A scroll compressor is a compressor including a fixed scroll having a fixing wrap and an orbiting scroll having an orbiting wrap corresponding to the fixing wrap of the fixed scroll, wherein the orbiting scroll orbits the fixed scroll to form a compression chamber moving continuously between the fixing wrap and the orbiting wrap to inhale and compress a refrigerant.

The scroll compressor is excellent compared to other types of compressors in view of vibrations and noise that are generated during an operation, because inhalation, compression, and discharge are performed successively.

In general, in an orbiting scroll of a scroll compressor, an orbiting wrap is formed on one side of a disk-shaped end plate, a boss portion is formed on the other side of the end plate where no orbiting wrap is formed, and a rotation shaft for driving the orbiting scroll is coupled to the boss portion. The scroll compressor is capable of reducing the diameter of the end plate because the orbiting wrap is formed over the entire area of the end plate. However, an action point at which a repulsive force of a refrigerant is applied upon compression is spaced from an action point at which a reaction force for cancelling the repulsive force is applied, so that the behavior of the orbiting scroll may become unstable upon an operation, and accordingly, the scroll compressor may cause great vibrations or noise.

As an alternative to the scroll compressor described above, a shaft penetration scroll compressor or a semi shaft penetration scroll compressor in which an action point at which a repulsive force of a refrigerant is applied and an action point for cancelling the repulsive force is applied are at the same location has been disclosed. The shaft penetration scroll compressor or the semi shaft penetration scroll compressor prevents an orbiting scroll from being inclined with respect to a rotation shaft, because the action point of the repulsive force of the refrigerant and the action point of the reaction force are at the same location.

However, the shaft penetration scroll compressor or the semi shaft penetration scroll compressor may not form an orbiting wrap over the entire area of an end plate because the rotation shaft needs to be inserted in the center portion of the end plate. Therefore, a compression space of a compression chamber is reduced, and furthermore, a design volume ratio of the scroll compressor is reduced.

It is an aspect of the disclosure to provide a scroll compressor capable of increasing a design volume ratio by changing a shape of a wrap.

It is another aspect of the disclosure to provide a scroll compressor capable of expanding a compression space by changing a shape of a wrap.

It is another aspect of the disclosure to provide a shaft penetration scroll compressor or a semi shaft penetration scroll compressor capable of increasing a design volume ratio by including a new shape of a wrap structure.

<CIT>, <CIT> and <CIT>are relevant prior art.

In accordance with the invention , a scroll compressor is provided as defined in claim <NUM>.

An included angle α of a first line segment connecting one end of the connection portion to a center of the compressing portion and a second line segment connecting the other end of the connection portion to the center of the compressing portion may be <NUM> ° or more.

Each of the first circular arc portion and the second circular arc portion may have a constant thickness, and the thickness of the first circular arc portion may be the same as the thickness of the second circular arc portion.

The compressing portion may further include a shaft coupling portion positioned in an inside of the second circular arc portion and spaced a preset distance from the second circular arc portion, wherein the eccentric portion is coupled to the shaft coupling portion.

The shaft coupling portion may include a third circular arc portion forming an outer surface of the shaft coupling portion, wherein a curvature of the third circular arc portion is constant.

A distance between the first circular arc portion and the second circular arc portion may be equal to a distance between the second circular arc portion and the third circular arc portion.

The connection portion may include: a first connection portion connecting the first circular arc portion to the second circular arc portion, and a second connection portion connecting the second circular arc portion to the third circular arc portion, wherein a curvature of the second connection portion changes from the second circular arc portion to the third circular arc portion.

Each of the first circular arc portion and the second circular arc portion may include an outer surface and an inner surface, and the third circular arc portion may include an outer surface.

The first connection portion may include a first connection surface connecting the outer surface of the first circular arc portion to the outer surface of the second circular arc portion, and a second connection surface connecting the inner surface of the first circular arc portion to the inner surface of the second circular arc portion.

The second connection portion may include a third connection surface connecting the outer surface of the second circular arc portion to the outer surface of the third circular arc portion.

A first angle which is an included angle of a line segment connecting one end of the first connection surface to the center of the compressing portion and a line segment connecting the other end of the first connection surface to the center of the compressing portion, a second angle which is an included angle of a line segment connecting one end of the second connection surface to the center of the compressing portion and a line segment connecting the other end of the second connection surface to the center of the compressing portion, and a third angle which is an included angle of a line segment connecting one end of the third connection surface to the center of the compressing portion and a line segment connecting the other end of the third connection surface to the center of the compressing portion may be different from each other.

The first angle may be <NUM> °, the second angle may be <NUM> °, and the third angle may be <NUM> °.

A center of the shaft coupling portion may be out of a center of the compressing portion.

The curved portion may be in a shape of an involute curve having a center which is off set from a center of the fixed scroll or the orbiting scroll.

According to a concept of the disclosure, a scroll compressor capable of increasing a design volume ratio by changing a shape of a wrap may be provided.

According to a concept of the disclosure, a scroll compressor capable of expanding a compression space by changing a shape of a wrap may be provided.

According to a concept of the disclosure, a shaft penetration scroll compressor or a semi shaft penetration scroll compressor capable of increasing a design volume ratio by including a new shape of a wrap structure may be provided.

Configurations illustrated in the embodiments and the drawings described in the present specification are only the preferred embodiments of the invention , and thus it is to be understood that various modified examples may replace the embodiments and the drawings described in the present specification.

Also, the terms used in the present specification are merely used to describe embodiments, and are not intended to limit and/or restrict the disclosure. In the present specification, it is to be understood that the terms such as "including" or "having," etc., are intended to indicate the existence of the features, numbers, operations, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, operations, components, parts, or combinations thereof may exist or may be added.

Also, it will be understood that, although the terms "first", "second", etc., may be used herein to describe various components, these components should not be limited by these terms. The above terms are used only to distinguish one component from another. For example, a first component discussed below could be termed a second component, and similarly, a second component may be termed a first component without departing from the scope of right of the disclosure.

In the following description, the terms "front end", "rear end", "upper portion", "lower portion", "upper end", and "lower end" are defined based on the drawings, and the shapes and positions of the corresponding components are not limited by the terms.

<FIG> is a longitudinal sectional view of a scroll compressor according to an embodiment of the invention.

A scroll compressor <NUM> includes a main body <NUM>, a fixed scroll <NUM> fixed inside the main body <NUM>, an orbiting scroll <NUM> orbiting the fixed scroll <NUM>, compressing portions <NUM> and <NUM> respectively provided in the fixed scroll <NUM> and the orbiting scroll <NUM>, and a driving motor <NUM> for driving the orbiting scroll <NUM>.

The main body <NUM> includes an upper cap <NUM> and a lower cap <NUM> respectively mounted on a top end and a lower end of the main body <NUM> to seal an inside of the main body <NUM>, a suction pipe <NUM> which a refrigerant enters, and a discharge pipe <NUM> for discharging the refrigerant entered the suction pipe <NUM> to an outside of the main body <NUM> after the refrigerant is compressed.

The fixed scroll <NUM> includes a first end plate <NUM> being in a shape of a disk, and a fixing wrap <NUM> extending downward from the first end plate <NUM> and forming a compression chamber together with an orbiting wrap <NUM> which will be described later.

The orbiting scroll <NUM> includes a second end plate <NUM> being opposite to the first end plate <NUM> and being in a shape of a disk, and the orbiting wrap <NUM> extending upward from the second end plate <NUM> and forming the compression chamber together with the fixing wrap <NUM>. Also, the orbiting scroll <NUM> includes a shaft coupling portion <NUM> in which an eccentric portion <NUM> of a rotation shaft <NUM> which will be described later is inserted.

Hereinafter, the compressing portions <NUM> and <NUM> includes the orbiting wrap <NUM> of the orbiting scroll <NUM> and the fixing wrap <NUM> of the fixed scroll <NUM>. That is, the compressing portions <NUM> and <NUM> may indicate all of the orbiting wrap <NUM> and the fixing wrap <NUM>.

The fixing wrap <NUM> of the fixed scroll <NUM> are engaged with the orbiting wrap <NUM> of the orbiting scroll <NUM> to form a compression chamber <NUM>. The compression chamber <NUM> is formed by the fixed scroll <NUM> and the orbiting scroll <NUM>, and a volume of the compression chamber <NUM> is reduced by an orbiting motion of the orbiting scroll <NUM>. Therefore, a refrigerant entered the compression chamber <NUM> is compressed.

A refrigerant entered the compression chamber <NUM> and compressed is discharged as a high-pressure refrigerant, and a refrigerant existing inside the compression chamber <NUM> presses the orbiting scroll <NUM> in a direction in which the orbiting scroll <NUM> is away from the fixed scroll <NUM>.

Because inside pressure of the compression chamber <NUM> is applied in a direction in which the orbiting scroll <NUM> is away from the fixed scroll <NUM>, a back pressure chamber <NUM> for transferring pressure in a direction in which the orbiting scroll <NUM> faces the fixed scroll <NUM> may be provided below the orbiting scroll <NUM>.

A refrigerant may be filled in an inside of the back pressure chamber <NUM>. The back pressure chamber <NUM> may be formed by a main frame <NUM>, the rotation shaft <NUM>, and the orbiting scroll <NUM>.

An Oldham's ring <NUM> for orbiting the orbiting scroll <NUM> without revolving the orbiting scroll <NUM> may be provided between the orbiting scroll <NUM> and the main frame <NUM>.

The main frame <NUM> and a sub frame <NUM> may be respectively fixed on upper and lower portions of an inner surface of the main body <NUM>, and the driving motor <NUM> may be positioned between the main frame <NUM> and the sub frame <NUM>.

The driving motor <NUM> may include a stator <NUM> and a rotor <NUM>.

The stator <NUM> may include a stator body <NUM>, and a coil <NUM> wound around the stator body <NUM>.

The stator body <NUM> may be a laminate formed by stacking a plurality of electrical steel sheets, and may be substantially in a shape of a cylinder, wherein a diameter of an outer circumference surface of the stator body <NUM> may be larger than a diameter of an inner circumference surface of the main body <NUM>, and therefore, the stator body <NUM> may be fitted in the main body <NUM> by interference fit.

The stator body <NUM> may include a plurality of teeth (not shown) arranged in a circumference direction on the inner portion that is opposite to an outer circumference of the rotor <NUM>. The coil <NUM> may be positioned at a slot (not shown) existing between neighboring teeth.

The rotor <NUM> may be a laminate formed by stacking a plurality of electrical steel sheets each being in a shape of a ring. A diameter of an inner circumference surface of the rotor <NUM> may be smaller than a diameter of an outer circumference surface of the rotation shaft <NUM>. The rotation shaft <NUM> may be fitted in the rotor <NUM> by interference fit. A method of fitting the rotation shaft <NUM> in the rotor <NUM> may be press-fit. Therefore, the rotation shaft <NUM> may rotate together with the rotor <NUM>.

The rotation shaft <NUM> includes a main shaft <NUM> inserted in the rotor <NUM>, and an eccentric portion <NUM> positioned at an upper portion of the main shaft <NUM> and having a shaft center being eccentric from a shaft center of the main shaft <NUM>.

The rotation shaft <NUM> may be installed between the main frame <NUM> and the sub frame <NUM> to transfer a rotation force generated by the driving motor <NUM> to the orbiting scroll <NUM>.

An upper portion of the rotation shaft <NUM> may be supported by the main frame <NUM> in such a way to be rotatable with respect to the main frame <NUM>. The main frame <NUM> may include a main bearing 15a for supporting rotations of the rotation shaft <NUM>.

A lower portion of the rotation shaft <NUM> may be supported by the sub frame <NUM> in such a way to be rotatable with respect to the sub frame <NUM>. The sub frame <NUM> may include a sub bearing 16a for supporting rotations of the rotation shaft <NUM>.

The orbiting scroll <NUM> may include the shaft coupling portion <NUM> in which the eccentric portion <NUM> is inserted. According to an embodiment of the disclosure, the shaft coupling portion <NUM> may protrude upward from the second end plate <NUM> of the orbiting scroll <NUM>. By the structure, the eccentric portion <NUM> may protrude upward from the second end plate <NUM>, and the eccentric portion <NUM> may be positioned alongside the orbiting wrap <NUM> and the fixing wrap <NUM>.

The orbiting scroll <NUM> may include an orbiting bearing 42a positioned on an inner surface of the shaft coupling portion <NUM>. The orbiting bearing 42a may support rotations of the eccentric portion <NUM>.

The above-described structure of the orbiting scroll <NUM> is referred to as a semi shaft penetration structure, and hereinafter, a semi shaft penetration scroll compressor will be described as an example. However, the disclosure is not limited to the semi shaft penetration scroll compressor, and may be applied to a shaft penetration scroll compressor.

In the case of the semi shaft penetration scroll compressor or the shaft penetration scroll compressor, because an action point at which a repulsive force of a refrigerant is applied upon compression and an action point at which a reaction force for cancelling the repulsive force is applied are at the same location, vibrations or noise that may be caused by an inclination of an orbiting scroll may be prevented. However, in the case of the semi shaft penetration scroll compressor or the shaft penetration scroll compressor, a rotation shaft needs to be inserted in a center of an end plate of an orbiting scroll. Therefore, it is difficult to form an orbiting wrap over the entire area of the end plate, and accordingly, a compression space and a design volume ratio may be reduced. According to a concept of the disclosure, a scroll compressor capable of expanding a compression space and increasing a design volume ratio by improving a wrap shape while having a semi shaft penetration structure or a shaft penetration structure is disclosed.

<FIG> is a top view of the orbiting scroll <NUM> in the scroll compressor <NUM> according to an embodiment of the disclosure.

Hereinafter, an orbiting wrap shape of the orbiting scroll <NUM> will be described as an example. Due to characteristics of the scroll compressor <NUM>, because a fixing wrap shape of the fixed scroll <NUM> corresponds to the orbiting wrap shape, the following descriptions may also be applicable to the fixing wrap <NUM> of the fixed scroll <NUM>.

Referring to <FIG>, the orbiting scroll <NUM> according to an embodiment of the disclosure may include the second end plate <NUM>, and an orbiting wrap protruding upward from the second end plate <NUM>.

The orbiting wrap may include a first circular arc portion <NUM> having a constant curvature, a second circular arc portion <NUM> positioned in an inside of the first circular arc portion <NUM> and having a constant curvature, and a connection portion <NUM> connecting the first circular arc portion <NUM> to the second circular arc portion <NUM>.

The first circular arc portion <NUM> may be in a shape of an arc having a preset radius. The second circular arc portion <NUM> may also be in a shape of a arc, like the first circular arc portion <NUM>, wherein a center of the second circular arc portion <NUM> may be at the same location as that of the first circular arc portion <NUM> and the radius of the second circular arc portion <NUM> may be smaller than that of the first circular arc portion <NUM>.

In an inside of the second circular arc portion <NUM>, the shaft coupling portion <NUM> may be positioned. An outer surface of the shaft coupling portion <NUM> may form a third circular arc portion <NUM>. A center of the third circular arc portion <NUM> may be at the same location as those of the first circular arc portion <NUM> and the second circular arc portion <NUM>, and the third circular arc portion <NUM> may be in a shape of anarc of which a radius is smaller than that of the second circular arc portion <NUM>.

The first circular arc portion <NUM> may have a thickness t1, and the second circular arc portion <NUM> may have a thickness t2.

According to an embodiment of the disclosure, the thickness t1 of the first circular arc portion <NUM> may be the same as the thickness t2 of the second circular arc portion <NUM>. Accordingly, t1 = t2.

Also, a distance d1 between the first circular arc portion <NUM> and the second circular arc portion <NUM> may be equal to a distance d2 between the second circular arc portion <NUM> and the third circular arc portion <NUM>. Accordingly, d1 = d2.

Because each of the first circular arc portion <NUM> and the second circular arc portion <NUM> is formed in a shape of an arc which is a part of a circle having a constant radius, each of the first circular arc portion <NUM> and the second circular arc portion <NUM> may have a constant curvature.

According to a concept of the disclosure, the connection portion <NUM> connecting the first circular arc portion <NUM> to the second circular arc portion <NUM> may have a curvature changing from the first circular portion <NUM> to the second circular portion <NUM>. The curvature of the connection portion <NUM> may change successively from the first circular arc portion <NUM> to the second circular arc portion <NUM>. The connection portion <NUM> may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve. A detailed shape of the connection portion <NUM> will be described later.

According to an embodiment of the disclosure, an included angle α of a line segment connecting one end of the connection portion <NUM> to a center of the orbiting scroll <NUM> and a line segment connecting the other end of the connection portion <NUM> to the center of the orbiting scroll <NUM> may be <NUM> °. The one end of the connection portion <NUM> may be a location at which the first circular arc portion <NUM> is connected to the connection portion <NUM>, and the other end of the connection portion <NUM> may be a location at which the second circular arc portion <NUM> is connected to the connection portion <NUM>.

<FIG> schematically shows the orbiting scroll <NUM> shown in <FIG>. <FIG> is a graph showing a distance from the center of the orbiting scroll <NUM> to the orbiting wrap <NUM> in the scroll compressor <NUM> according to an embodiment of the disclosure. <FIG> is a graph obtained by enlarging a portion of the graph shown in <FIG>.

<FIG> shows an outer surface of the first circular arc portion <NUM>, an outer surface of the second circular arc portion <NUM>, and outer surfaces of the third circular arc portion <NUM> and the connection portion <NUM>, in the orbiting scroll <NUM> shown in <FIG>.

In <FIG>, R<NUM> indicates a distance from the center of the orbiting scroll <NUM> to the first circular arc portion <NUM>, R<NUM> indicates a distance from the center of the orbiting scroll <NUM> to the second circular arc portion <NUM>, and R indicates a distance from the center of the orbiting scroll <NUM> to the connection portion <NUM>.

Also, θ<NUM> indicates an angle of the one end of the connection portion <NUM> with respect to a preset reference line, θ<NUM> indicates an angle of the other end of the connection portion <NUM> with respect to the preset reference line, and θ indicates an angle of a point of the connection portion <NUM> with respect to the preset reference line. The one end of the connection portion <NUM> may be a location at which the first circular arc portion <NUM> is connected to the connection portion <NUM>, and the other end of the connection portion <NUM> may be a location at which the second circular arc portion <NUM> is connected to the connection portion <NUM>.

Referring to <FIG>, the distance R<NUM> from the center of the orbiting scroll <NUM> to the first circular arc portion <NUM> may be constant, and the distance R<NUM> from the center of the orbiting scroll <NUM> to the second circular arc portion <NUM> may also be constant. The connection portion <NUM> may connect the first circular arc portion <NUM> to the second circular arc portion <NUM> with a variable curvature, and a distance between the connection portion <NUM> and the center of the orbiting scroll <NUM> may change successively.

<FIG> is a graph showing a distance from the center of the orbiting scroll <NUM> to the connection portion <NUM> according to a change of an angle.

In <FIG>, ε indicates a distance by which the shaft center of the eccentric portion <NUM> is eccentric from the shaft center of the main shaft <NUM>, and t indicates the thickness of the first circular arc portion <NUM> and the second circular arc portion <NUM>.

As shown in <FIG>, the distance R from the center of the orbiting scroll <NUM> to the connection portion <NUM> may satisfy the following equation.

When the connection portion <NUM> connecting the first circular arc portion <NUM> to the second circular arc portion <NUM> is referred to as a first connection portion and a connection portion connecting the second circular arc portion <NUM> to the third circular arc portion <NUM> is referred to as a second connection portion, a distance R between the second connection portion and the center of the orbiting scroll <NUM> may satisfy the following equation.

More specifically, referring to <FIG>, the distance R between the connection portion and the center of the orbiting scroll <NUM> from one end of the connection portion <NUM> to the other end of the connection portion <NUM> may satisfy the following equation.

It is seen from the above equation that the connection portion is in a shape of a cosine curve. Also, it is seen that the connection portion is in a shape of a cosine curve ranging from <NUM> ° to <NUM> °, regardless of α.

Although not shown in the drawings, according to another embodiment of the disclosure, the connection portion <NUM> may be in any one shape of a Bezier curve, a Hermite curve, or a B-spline curve. The above-mentioned curves may ensure curvature continuity, and have a high shape degree of freedom due to smooth changes of curvatures.

Hereinafter, various embodiments of the disclosure will be described. In the following embodiments, descriptions about the same components as those described above in the above-described embodiments will be omitted.

<FIG> is a top view of an orbiting scroll in a scroll compressor according to another embodiment of the disclosure. As described above, an orbiting wrap shape of an orbiting scroll will be described as an example, however, the orbiting wrap shape of the orbiting scroll is also applicable to a fixing wrap of a fixed scroll.

Referring to <FIG>, an orbiting scroll <NUM> may include an end plate <NUM>, and an orbiting wrap protruding above the end plate <NUM>. The orbiting wrap may include a first circular arc portion <NUM> having a constant curvature, a second circular arc portion <NUM> positioned in an inside of the first circular arc portion <NUM> and having a constant curvature, and a connection portion <NUM> connecting the first circular arc portion <NUM> to the second circular arc portion <NUM>. In an inside of the second circular arc portion <NUM>, a shaft coupling portion <NUM> may be positioned, and an outer surface of the shaft coupling portion <NUM> may form a third circular arc portion <NUM>. The third circular arc portion <NUM> may be in a shape of a small arc of which a center is at the same location as those of the first circular arc portion <NUM> and the second circular arc portion <NUM> and which has a smaller radius than the second circular arc portion <NUM>.

A thickness of the first circular arc portion <NUM> may be t1. A thickness of the second circular arc portion <NUM> may be t2. The thickness t1 of the first circular arc portion <NUM> may be equal to the thickness t2 of the second circular arc portion <NUM>. Accordingly, t1=t2 may be satisfied. Also, a distance d1 between the first circular arc portion <NUM> and the second circular arc portion <NUM> may be equal to a distance d2 between the second circular arc portion <NUM> and the third circular arc portion <NUM>. Accordingly, d1=d2 may be satisfied.

According to another embodiment of the disclosure, an included angle α of a line segment connecting one end of the connection portion <NUM> to a center of an orbiting scroll <NUM> and a line segment connecting the other end of the connection portion <NUM> to the center of the orbiting scroll <NUM> may be <NUM> ° In <FIG>, the included angle α is shown to be <NUM> °, however, the included angle α of <NUM> ° is an example. According to an embodiment of the disclosure, the included angle α may be <NUM> ° or more.

The connection portion <NUM> may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve. <FIG> is a top view of an orbiting scroll in a scroll compressor according to another embodiment of the disclosure.

Referring to <FIG>, each of a first circular arc portion <NUM> and a second circular arc portion <NUM> may include an outer surface and an inner surface. More specifically, the first circular arc portion <NUM> may include an outer surface <NUM> and an inner surface <NUM>. The second circular arc portion <NUM> may include an outer surface <NUM> and an inner surface <NUM>.

Also, a connection portion may include a first connection portion <NUM> connecting the first circular arc portion <NUM> to the second circular arc portion <NUM>, and a second connection portion <NUM> connecting the second circular arc portion <NUM> to a shaft coupling portion <NUM>.

The first connection portion <NUM> may include an outer surface <NUM> and an inner surface <NUM>, and the second connection portion <NUM> may include an outer surface <NUM> and an inner surface <NUM>. Hereinafter, the outer surface <NUM> and the inner surface <NUM> of the first connection portion <NUM> may indicate a first connection surface and a second connection surface, respectively. The outer surface <NUM> of the second connection portion <NUM> may indicate a third connection surface.

According to another embodiment of the disclosure, the connection portion may include the first connection surface <NUM> connecting the outer surface <NUM> of the first circular arc portion <NUM> to the outer surface <NUM> of the second circular arc portion <NUM>, the second connection surface <NUM> connecting the inner surface <NUM> of the first circular arc portion <NUM> to the inner surface <NUM> of the second circular arc portion <NUM>, and the third connection surface <NUM> connecting the outer surface <NUM> of the second circular arc portion <NUM> to a third circular arc portion <NUM>.

The connection portion may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve.

Referring to <FIG>, an included angle of a line segment connecting one end of the first connection surface <NUM> to a center of an orbiting scroll <NUM> and a line segment connecting the other end of the first connection surface <NUM> to the center of the orbiting scroll <NUM> may be α<NUM>. Also, an included angle of a line segment connecting one end of the second connection surface <NUM> to the center of the orbiting scroll <NUM> and a line segment connecting the other end of the second connection surface <NUM> to the center of the orbiting scroll <NUM> may be α<NUM>. Also, an included angle of a line segment connecting one end of the third connection surface <NUM> to the center of the orbiting scroll <NUM> and a line segment connecting the other end of the third connection surface <NUM> to the center of the orbiting scroll <NUM> may be α<NUM>.

According to another embodiment of the disclosure, the included angle α<NUM>, the included angle α<NUM>, and the included angle α<NUM> may be different from each other. More specifically, the included angle α<NUM> may be greater than the included angle α<NUM>, and the included angle α<NUM> may be greater than the included angle α<NUM>. For example, as shown in <FIG>, the included angle α<NUM> may be <NUM> °, the included angle α<NUM> may be <NUM> °, and the included angle α<NUM> may be <NUM> °.

<FIG> is a top view of an orbiting scroll in a scroll compressor according to another embodiment of the disclosure.

The connection portion may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve. Referring to <FIG>, in the scroll compressor according to another embodiment of the disclosure, the shaft center of the eccentric portion <NUM> may be eccentric by a preset distance from a center of the orbiting scroll <NUM>. For example, the shaft center of the eccentric portion <NUM> may be eccentric by a distance e in an up direction from the center of the orbiting scroll <NUM>, as shown in <FIG>. Through the structure, the scroll compressor according to another embodiment of the disclosure may reduce a size of a shaft coupling portion <NUM>. Accordingly, a compression space of the scroll compressor may be expanded, and furthermore, a design volume ratio may increase.

Referring to <FIG>, according to another embodiment of the disclosure, the scroll compressor may be a general scroll compressor, neither a semi shaft penetration scroll compressor nor a shaft penetration scroll compressor. The general scroll compressor may have a structure in which an eccentric portion of a rotation shaft is inserted in a boss portion protruding below an end plate <NUM> of an orbiting scroll <NUM>, wherein an orbiting wrap may be formed over the entire upper area of the end plate <NUM> of the orbiting scroll <NUM>. The general scroll compressor is advantageous in view of a compression space and a design volume ratio.

According to another embodiment of the disclosure, the scroll compressor may have a general scroll compressor structure in which an orbiting wrap includes a plurality of circular arc portions <NUM>, <NUM>, and <NUM> having a constant curvature and connection portions <NUM>, <NUM>, and <NUM> connecting the circular arc portions <NUM>, <NUM>, and <NUM> to each other. The circular arc portions <NUM>, <NUM>, and <NUM> may include a first circular arc portion <NUM>, a second circular arc portion <NUM> positioned in an inside of the first circular arc portion <NUM> and spaced from the first circular arc portion <NUM>, and a third circular arc portion <NUM> positioned in an inside of the second circular arc portion <NUM> and spaced from the second circular arc portion <NUM>. The connection portions <NUM>, <NUM>, and <NUM> may include a first connection portion <NUM> connecting one end of the first circular arc portion <NUM> to one end of the second circular arc portion <NUM>, a second connection portion <NUM> connecting the other end of the second circular arc portion <NUM> to one end of the third circular arc portion <NUM>, and a third connection portion <NUM> extending from the other end of the third circular arc portion <NUM>. Each of the connection portions <NUM>, <NUM>, and <NUM> may be in a shape of a part of a cosine curve, and have a curvature changing successively between the circular arc portions <NUM>, <NUM>, and <NUM>. In contrast, the connection portions <NUM>, <NUM>, and <NUM> may be in any one shape of a Bezier curve, a Hermite curve, or a B-spline curve. Through the structure, a compression space may be expanded compared to a wrap of an involute structure, and a design volume ratio may increase.

Referring to <FIG>, an orbiting scroll <NUM> may have a structure of a semi shaft penetration scroll compressor or a shaft penetration scroll compressor. The orbiting scroll <NUM> may include an end plate <NUM>, and an orbiting wrap protruding above the end plate <NUM>. The orbiting wrap may include a circular arc portion <NUM> having a constant curvature, a shaft coupling portion <NUM> which is positioned in an inside of the circular arc portion <NUM> and in which the eccentric portion <NUM> (see <FIG>) is inserted, and a connection portion <NUM> connecting the circular arc portion <NUM> to the shaft coupling portion <NUM>.

The circular arc portion <NUM> may be in a shape of an arc having a preset radius. The shaft coupling portion <NUM> may be in a shape of an involute curve of which a center is off set. In other words, the shaft coupling portion <NUM> may be in a shape of an involute curve having a center c2 which is off set from a center c1 of the end plate <NUM> having a circular shape. The eccentric portion <NUM> may be inserted in a center portion of the shaft coupling portion <NUM>.

The connection portion <NUM> may connect one end of the circular arc portion <NUM> to one end of the shaft coupling portion <NUM>. The connection portion <NUM> may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve. The above-mentioned curves may ensure curvature continuity, and have a high shape degree of freedom due to smooth changes of curvatures.

Also, as described above, the connection portion <NUM> may be in any one shape of a Bezier curve, a Hermite curve, or a B-spline curve. Hereinafter, the Bezier curve, the Hermite curve, or the B-spline curve is also referred to as a connection curve.

According to another embodiment of the disclosure, because the connection portion <NUM> is in a shape of a connection curve, the thickness t of the orbiting wrap may be optimized by adjusting a weight of the connection curve. In other words, by adjusting a weight of the connection curve in a process of optimizing the thickness of the orbiting wrap, the thickness t of the orbiting wrap may be finely adjusted. As described above, the connection curve may ensure curvature continuity, and have a high shape degree of freedom due to smooth changes of curvatures. By adjusting the weight using the characteristic of the connection curve, the wrap thickness t may be easily optimized.

Referring to <FIG>, an orbiting scroll <NUM> may have a general scroll compressor structure. The orbiting scroll <NUM> may include an end plate <NUM>, and an orbiting wrap protruding above the end plate <NUM>. The orbiting wrap may include a circular arc portion <NUM> having a constant curvature, a curved portion <NUM> positioned in an inside of the circular arc portion <NUM>, and a connection portion <NUM> connecting the circular arc portion <NUM> to the curved portion <NUM>.

The circular arc portion <NUM> may be in a shape of an arc having a preset radius. The curved portion <NUM> may be in a shape of an involute curve of which a center is off set. In other words, the curved portion <NUM> may be in a shape of an involute curve having a center c2 which is off set from a center c1 of the end plate <NUM> having a circular shape.

The connection portion <NUM> may connect one end of the circular arc portion <NUM> to one end of the curved portion <NUM>. The connection portion <NUM> may be in any one shape of a cosine curve, a Bezier curve, a Hermite curve, or a B-spline curve. The above-mentioned curves may ensure curvature continuity, and have a high shape degree of freedom due to smooth changes of curvatures.

According to another embodiment of the disclosure, because the connection portion <NUM> is in a shape of a connection curve, the thickness t of the orbiting wrap may be optimized by adjusting a weight of the connection curve. In other words, by adjusting a weight of the connection curve in a process of optimizing the thickness of the orbiting wrap, the wrap thickness t may be finely adjusted. As described above, the connection curve may ensure curvature continuity and have a high shape degree of freedom due to smooth changes of curvatures. By adjusting the weight using the characteristic of the connection curve, the wrap thickness t may be easily optimized.

<FIG> is a top view of a fixed scroll corresponding to an orbiting scroll shown in <FIG>.

Referring to <FIG>, a fixed scroll 20a may include an end plate 21a being in a shape of a disk, and a fixing wrap 22a extending downward from the end plate 21a and forming a compression chamber <NUM> (see <FIG>) together with an orbiting wrap. <FIG> is a top view showing the fixed wrap 20a of the fixed scroll 20a after being arranged to face upward.

According to another embodiment of the disclosure, the thickness t of the fixed wrap 22a of the fixed scroll 20a may satisfy the following equation.

Herein, e represents an eccentric distance, and the eccentric distance is a distance between a center of the rotation shaft <NUM> and a center of the eccentric portion <NUM> as shown in <FIG>. Also, Tmin represents a minimum thickness of the fixed wrap 22a, and Tmax represents a maximum thickness of the fixed wrap 22a. According to another embodiment of the disclosure, when the thickness t of the fixed wrap 22a satisfies the above equation, a technical effect of reductions of a trust area and trust loss through optimization of the fixed wrap thickness may be achieved.

Although not shown in the drawing, a thickness of a fixed wrap of a fixed scroll corresponding to the orbiting scroll shown in <FIG> may satisfy the following equation.

Herein, e represents an eccentric distance, and the eccentric distance is a distance between a center of the rotation shaft <NUM> and a center of the eccentric portion <NUM> as shown in <FIG>. Also, Tmin represents a minimum thickness of the fixed wrap, and Tmax represents a maximum thickness of the fixed wrap. According to another embodiment of the disclosure, when the thickness t of the fixed wrap satisfies the above equation, a technical effect of reductions of a trust area and trust loss through optimization of the fixed wrap thickness may be achieved.

Claim 1:
A scroll compressor comprising:
a main body (<NUM>);
a fixed scroll (<NUM>) fixed inside the main body;
an orbiting scroll (<NUM>) orbiting the fixed scroll;
a plurality of compressing portions (<NUM>, <NUM>) respectively provided in the fixed scroll and the orbiting scroll, and
a rotation shaft (<NUM>) rotating with respect to a rotation axis and including an eccentric portion (<NUM>) being eccentric from the rotation axis, wherein the eccentric portion is positioned alongside the compressing portion in a direction crossing the rotation axis, and
wherein each compressing portion comprises
a circular arc portion (<NUM>) of which a curvature is constant,
a curved portion (<NUM>) positioned in an inside of the circular arc portion and spaced a preset distance from the circular arc portion, and
a connection portion (<NUM>) connecting the circular arc portion to the curved portion, wherein a curvature of the connection portion changes from the circular arc portion to the curved portion,
characterized in that
the connection portion is in a shape of one of a cosine curve, a Bezier curve, a Hermite curve, and a B-spline curve, and
when the curved portion is in a shape of an arc of which a curvature is constant, the circular arc portion is referred to as a first circular arc portion, and the curved portion is referred to as a second circular arc portion,
wherein,
when a distance from a center of the compressing portion to the connection portion is R,
a distance from the center of the compressing portion to the first circular arc portion is R<NUM>,
a distance from the center of the compressing portion to the second circular arc portion is R<NUM>, a thickness of the first circular arc portion is t,
a distance by which a center of the eccentric portion is eccentric from a center of the rotation shaft is ε,
an angle of one end of the first circular arc portion with respect to a preset reference line is θ<NUM>,
an angle of one end of the second circular arc portion with respect to the preset reference line is θ<NUM>, and
an angle of a point of the connection portion with respect to the preset reference line is θ, <MAT> is satisfied.