Patent Description:
In general, a compressor is a mechanical apparatus that receives power from a power generating apparatus such as an electric motor and a turbine and compresses air, refrigerant, or other various working gases to increase a pressure thereof. Compressors are widely used throughout household appliances such as a refrigerator, an air conditioner and a clothes dryer, or industries.

Compressors include a reciprocating compressor, a scroll compressor, and a rotary compressor. The reciprocating compressor having a compression space into and from which a working gas is introduced and discharged, between a piston and a cylinder compresses the working gas as the piston reciprocates linearly inside the cylinder. The scroll compressor having a compression space into and from which a working gas is introduced and discharged, between an orbiting scroll and a fixed scroll compresses the working gas as the orbiting scroll rotates along the fixed scroll. The rotary compressor having a compression space into and from which a working gas is introduced and discharged, between an eccentrically rotating rolling piston and a piston compresses the working gas as the rolling piston rotates eccentrically along an inner wall of the cylinder.

The scroll compressor and rotary compressor include a motor for generating a rotational motion. The motor includes a stator and a rotor rotating inside the stator. Because the stator is interference fitted into a housing of a compressor, a compressive stress occurs on the stator by the housing. The compressive stress occurring on the stator may degrade the electromagnetic properties of the stator.

<CIT>, <CIT>, <CIT> and <CIT> each disclose motors with features to reduce a pressing load on parts of a stator.

It is an aspect of the disclosure to provide a compressor capable of reducing a compressive stress occurring on a stator to prevent the efficiency of a motor from being lowered.

According to the invention, there is provided a compressor according to claim <NUM>. Preferred features are set out in the dependent claims.

As is apparent from the above, according to the disclosure, a compressive stress occurring on a stator of a motor is reduced by a housing of a compressor, so that the efficiency of the motor can be improved.

Configurations shown in the embodiments and the drawings described in the present specification are only the preferred embodiments of the present disclosure, and thus it is to be understood that various modified examples, which may replace the embodiments and the drawings described in the present specification, are possible when filing the present application.

Like reference numbers or signs in the various figures of the application represent parts or components that perform substantially the same functions. In order to clearly illustrate the disclosure, parts not related to the description are omitted from the drawings, and the size of the components may be slightly exaggerated to facilitate understanding.

The terms used in the present specification are used to describe the embodiments of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. It will be understood that when the terms "includes," "comprises," "including," and/or "comprising," when used in this specification, specify the presence of stated features, figures, steps, components, or combination thereof, but do not preclude the presence or addition of one or more other features, figures, steps, components, members, or combinations thereof.

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, and the terms are only used to distinguish one component from another. For example, without departing from the scope of the disclosure, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

In the present specification, a rotary compressor is described for convenience of description, but is not limited thereto.

<FIG> is an axial cross-sectional view of a compressor according to an embodiment of the disclosure, <FIG> is a plan view of a stator of a motor of the compressor according to an embodiment of the disclosure, <FIG> is an enlarged view of a portion of the stator in <FIG>, <FIG> is a plan view of a state in which the stator in <FIG> is coupled to a housing, and <FIG> is an enlarged view of a portion of the stator and the housing in <FIG>.

Referring to <FIG>, a compressor <NUM> includes a compression unit <NUM> for compressing a refrigerant, a motor <NUM> for driving the compression unit, and a housing <NUM> for accommodating the compression unit <NUM> and the motor <NUM>. The compressor <NUM> may be configured such that an axial direction of a rotating shaft <NUM> of the motor <NUM> becomes the gravity direction. Hereinafter, the axial direction of the rotating shaft <NUM> is referred to as an up-down direction, and the up-down direction is defined as shown in <FIG>.

The motor <NUM> may be fixed to the housing <NUM> above the compression unit <NUM>. The motor <NUM> is interference fitted into and fixed to an inner circumferential surface of the housing <NUM>. The motor <NUM> includes a stator <NUM> interference fitted into and fixed to the inner circumferential surface of the housing <NUM> and a rotor <NUM> configured to rotate inside the stator <NUM>. The rotating shaft <NUM> is fixed to the rotor <NUM> to rotate together with the rotation of the rotor <NUM>.

The compressor <NUM> may include a cylindrical housing <NUM> disposed at a central portion in the up-down direction, an upper cover <NUM> covering an upper opening of the housing <NUM>, and a lower cover <NUM> covering a lower opening of the housing <NUM>.

The stator <NUM> includes a core <NUM> and a coil <NUM> wound on the core <NUM>. The core <NUM> may be formed by stacking a plurality of electrical steel sheets. The electric steel sheet is substantially annular, and the core <NUM> is substantially cylindrical. An outer diameter A (see <FIG>) of the core <NUM> is larger than an inner diameter B (see <FIG>) of the housing <NUM>, and the core <NUM> is interference fitted into and coupled to the housing <NUM>. Methods of fitting the core <NUM> into the housing <NUM> include shrinkage fit and press fitting. In general, the press fitting is a method of heating the housing <NUM> to a certain temperature or more and pushing the core <NUM> inside the housing <NUM>.

The rotor <NUM> may be formed by stacking a plurality of electrical steel sheets. The electric steel sheet is substantially annular, and the rotor <NUM> is substantially cylindrical. An inner diameter of the rotor <NUM> is smaller than an outer diameter of the rotating shaft <NUM>, and the rotating shaft <NUM> may be interference fitted into and coupled to the rotor <NUM>. An outer diameter of the rotor <NUM> is smaller than an inner diameter of the core <NUM> of the stator <NUM>, and there is a gap between the rotor <NUM> and the stator <NUM>. A compression unit side balancer <NUM> may be disposed on a bottom surface of the rotor <NUM>.

The rotating shaft <NUM> includes a shaft body <NUM> to which the rotor <NUM> is fitted, and a first eccentric shaft <NUM> and a second eccentric shaft <NUM> installed at a lower portion of the shaft body <NUM> and having axial centers eccentric from an axial center of the shaft body <NUM>. The first eccentric shaft <NUM> and the second eccentric shaft <NUM> may be arranged to have a phase difference of <NUM> degrees in a circumferential direction of the rotating shaft <NUM>. A portion of the shaft body <NUM> below the rotor <NUM> is rotatably supported by a main bearing <NUM>, and a lower end of the shaft body <NUM> is rotatably supported by a sub bearing <NUM>.

The compressor <NUM> may include a discharge part <NUM> for discharging a high-pressure refrigerant gas compressed in the compression unit <NUM> to the outside of the compressor <NUM>, a first suction pipe <NUM> and a second suction pipe <NUM> for sucking a refrigerant gas from the outside of the compressor <NUM>.

The stator <NUM> of the motor <NUM> and the main bearing <NUM> may be fixed to the housing <NUM>. The compressor <NUM> may include a first suction pipe <NUM> and a second suction pipe <NUM> inserted into through holes formed on the housing <NUM> to suck a refrigerant gas from the outside of the compressor <NUM>. The upper cover <NUM> may be formed in an upside-down bowl shape. The compressor <NUM> may include a discharge part <NUM> inserted into a through hole formed at the top of the upper cover <NUM> to discharge the high-pressure refrigerant gas compressed in the compression unit <NUM> to the outside of the compressor <NUM>. The lower cover <NUM> may be formed in a bowl shape. The upper cover <NUM> and the lower cover <NUM> may be fixed to the housing <NUM>.

The compression unit <NUM> may include a first cylinder <NUM>, a second cylinder <NUM>, and a disk-shaped partition <NUM> partitioning the first cylinder <NUM> and the second cylinder <NUM>. The compression unit <NUM> is disposed above the second cylinder <NUM> to cover the second cylinder <NUM> and may include the main bearing <NUM> rotatably supporting the rotating shaft <NUM>. The compression unit <NUM> is disposed below the first cylinder <NUM> to cover the first cylinder <NUM> and may include the sub bearing <NUM> rotatably supporting the rotating shaft <NUM>. The main bearing <NUM> may be fixed to the housing <NUM> by welding or the like. The sub bearing <NUM> may be fixed to the main bearing <NUM> by fastening members such as bolts.

The compression unit <NUM> may include a first cover <NUM> forming a first discharge chamber 161a together with the sub bearing <NUM>, and a second cover <NUM> forming a second discharge chamber 162a together with the main bearing <NUM>. The compression unit <NUM> may include a first operation chamber <NUM> formed by the first cylinder <NUM>, the partition <NUM>, and the sub bearing <NUM>, and a second operation chamber <NUM> formed by the second cylinder <NUM>, the partition <NUM>, and the main bearing <NUM>.

The compression unit <NUM> may include a first piston <NUM> into which the first eccentric shaft <NUM> of the rotating shaft <NUM> is inserted and rotating with the rotating shaft <NUM> in the first operation chamber <NUM>, and a second piston <NUM> into which the second eccentric shaft <NUM> of the rotating shaft <NUM> is inserted and rotating with the rotating shaft <NUM> in the second operation chamber <NUM>.

The first cylinder <NUM> is provided with a first suction passage <NUM> penetrating in a direction (radial direction) orthogonal to the axial direction of the rotating shaft <NUM> to communicate the first operation chamber <NUM> with the outside of the first cylinder <NUM>. The first cylinder <NUM> is also provided with a first discharge gas passage <NUM> penetrating in the axial direction of the rotating shaft <NUM> from the outside of the first operation chamber <NUM>.

The second cylinder <NUM> is provided with a second suction passage <NUM> penetrating in a direction (radial direction) orthogonal to the axial direction of the rotating shaft <NUM> to communicate the second operation chamber <NUM> with the outside of the second cylinder <NUM>. The second cylinder <NUM> is also provided with a second discharge gas passage <NUM> penetrating in the axial direction of the rotating shaft <NUM> from the outside of the second operation chamber <NUM>.

The compression unit <NUM> includes the first suction pipe <NUM> having one end inserted into the first suction passage <NUM> and the other end connected to an accumulator, and the second suction pipe <NUM> having one end inserted into the second suction passage <NUM> and the other end connected to the accumulator. The compression unit <NUM> includes a communication passage <NUM> communicating the first suction passage <NUM> and the second suction passage <NUM>. The communication passage <NUM> includes a partition through hole <NUM> formed in the axial direction on the partition <NUM>, a first through hole <NUM> formed on the first cylinder <NUM> to communicate the partition through hole <NUM> with the first suction passage <NUM>, and a second through hole <NUM> formed on the second cylinder <NUM> to communicate the partition through hole <NUM> with the second suction passage <NUM>.

Referring to <FIG>, the core <NUM> of the stator <NUM> includes an annular back yoke <NUM> in contact with the housing <NUM>, and a tooth <NUM> extending inward from the back yoke <NUM>. The core <NUM> includes a plurality of the teeth <NUM> formed in a circumferential direction on an inner portion thereof facing an outer circumferential surface of the rotor <NUM>. The coil <NUM> is wound on the teeth <NUM> of the core <NUM>.

The motor <NUM> includes a stress absorber <NUM> provided on the back yoke <NUM> of the core <NUM> of the stator <NUM>. The stress absorber <NUM> is provided on the side opposite to one side of the back yoke <NUM> from which the tooth <NUM> extends. The motor <NUM> may include a plurality of the stress absorbers <NUM> corresponding to the plurality of teeth <NUM>.

The stress absorber <NUM> is configured to absorb a compressive stress transmitted from the housing <NUM> to the stator <NUM> by coupling with the housing <NUM>. The stress absorber <NUM> includes at least one deformation portion <NUM>, at least one contact portion <NUM>, and at least one cavity <NUM>. The deformation portion <NUM> is configured to be compressed and deformed by the housing <NUM> when the stator <NUM> is interference fitted into and coupled to the housing <NUM>. The cavity <NUM> is formed in a radial inside of the deformation portion <NUM> to provide a space in which the deformation portion <NUM> may be deformed.

The contact portion <NUM> protrudes radially outward from the deformation portion <NUM>. The contact portion <NUM> is configured to come into contact with an inner surface of the housing <NUM> when the stator <NUM> is coupled to the housing <NUM>. The housing <NUM> presses the contact portion <NUM> of the stator <NUM> when the motor <NUM> is interference fitted into and coupled to the housing <NUM>. When the housing <NUM> presses the contact portion <NUM>, the deformation portion <NUM> is deformed to the cavity <NUM> side together with the contact portion <NUM>. On the deformation portion <NUM> where deformation occurs, stress occurs and a restoring force to return to the original state is generated. Therefore, the stator <NUM> is coupled and fixed to the housing <NUM>. Further, because all coupling forces are applied to the deformable portion <NUM>, little stress occurs on the back yoke <NUM> that is not in contact with the housing <NUM>. Therefore, the electromagnetic characteristics of the motor <NUM> are not lowered.

The contact portion <NUM> protrudes radially outward compared to the portion of the back yoke <NUM> where the stress absorber <NUM> is not formed, and a width C in which the contact portion <NUM> protrudes radially outward from the deformation portion <NUM> is larger than a difference between an outer radius A of the stator <NUM> and an inner radius B of the housing <NUM>. Therefore, when the stator <NUM> is coupled to the housing <NUM>, the housing <NUM> does not press other portion of the core <NUM> except for the stress absorber <NUM> of the stator <NUM>.

The deformation portion <NUM> is deformed to the cavity <NUM> side by the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. The cavity <NUM> has a width D larger than the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. Therefore, even when the deformation portion <NUM> is deformed to the cavity <NUM> side, the deformation portion <NUM> does not press a portion of the back yoke <NUM> on a radial inner side of the cavity <NUM>.

The contact portion <NUM> may protrude to have the width C sufficiently larger than the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. Therefore, even when a tolerance of the inner radius B of the housing <NUM> or a tolerance of the outer radius A of the stator <NUM> occurs, the housing <NUM> does not press other portion of the core <NUM> except for the stress absorber <NUM> of the stator <NUM>.

The cavity <NUM> may have a sufficiently large radial width D compared to the protruding width C of the contact portion <NUM>. Therefore, even when a tolerance of the protruding width C of the contact portion <NUM>, a tolerance of the inner radius B of the housing <NUM>, or a tolerance of the outer radius A of the stator <NUM> occurs, the deformation portion <NUM> does not press the portion of the back yoke <NUM> on the radial inner side of the cavity <NUM>.

The deformation portion <NUM> is formed in a cantilever shape. The cavity <NUM> is provided such that a central portion of the deformation portion <NUM> is disposed at a central portion of the cavity <NUM>. The contact portion <NUM> is provided to protrude radially outward from a cantilever end of the deformation portion <NUM>. The core <NUM> of the stator <NUM> may include a plurality of the stress absorbers <NUM> corresponding to the plurality of teeth <NUM>. Each of the stress absorbers <NUM> is disposed on a radial outer side of each of the teeth <NUM>.

Each of the stress absorbers <NUM> includes the at least one deformation portion <NUM>, the at least one contact portion <NUM>, and the at least one cavity <NUM>. The back yoke <NUM> includes two of the deformation portions <NUM>, two of the contact portions <NUM>, and two of the cavities <NUM>, which are symmetrically disposed with respect to the center of each of the teeth <NUM> for each of the teeth <NUM>. The deformation portions <NUM> are formed in a cantilever shape extending outwardly from the center of the teeth <NUM>.

The contact portion <NUM> is formed to come into surface contact with the inner surface of the housing <NUM> when the deformation portion <NUM> is deformed. When the deformation portion <NUM> is formed in a cantilever shape, the contact portion <NUM> is formed to protrude higher toward the cantilever end.

A circumferential width of a contact surface in which the at least one contact portion <NUM> included in one of the stress absorber <NUM> is in contact with the housing <NUM> may be larger than a radial thickness F of the housing <NUM>. When the circumferential width of the contact surface is large, the stator <NUM> may be more stably fixed to the inner surface of the housing <NUM>.

When one of the stress absorber <NUM> includes two of the contact portions <NUM>, the sum of the circumferential widths E of the contact portions <NUM> and the contact surface of the housing <NUM> may be larger than the radial thickness F of the housing <NUM>. That is, when two of the contact portions <NUM> are disposed with respect to the center of each of the teeth <NUM>, each of the contact portions <NUM> may have a contact surface of the circumferential width E exceeding half of the radial thickness F of the housing <NUM>.

<FIG> is a plan view of a stator of a motor of a compressor according to an example of the disclosure not covered by the present invention, <FIG> is an enlarged view of a portion of the stator in <FIG>, <FIG> is a plan view of a state in which the stator in <FIG> is coupled to a housing, and <FIG> is an enlarged view of a portion of the stator and the housing in <FIG>.

Referring to <FIG>, the core <NUM> of the stator <NUM> may include the annular back yoke <NUM> in contact with the housing <NUM>, and the teeth <NUM> extending inward from the back yoke <NUM>. The core <NUM> may include a plurality of the teeth <NUM> in the circumferential direction on the inner portion thereof facing the outer circumferential surface of the rotor <NUM>. The coil <NUM> may be wound on the teeth <NUM> of the core <NUM>.

The motor <NUM> may include a stress absorber <NUM> provided on the back yoke <NUM> of the core <NUM> of the stator <NUM>. The stress absorber <NUM> may be provided on the side opposite to one side of the back yoke <NUM> from which the tooth <NUM> extends. The motor <NUM> may include a plurality of the stress absorbers <NUM> corresponding to the plurality of teeth <NUM>.

The stress absorber <NUM> is configured to absorb a compressive stress transmitted from the housing <NUM> to the stator <NUM> by coupling with the housing <NUM>. The stress absorber <NUM> may include at least one deformation portion <NUM>, at least one contact portion <NUM>, and at least one cavity <NUM>. The deformation portion <NUM> is configured to be compressed and deformed by the housing <NUM> when the stator <NUM> is interference fitted into and coupled to the housing <NUM>. The cavity <NUM> is formed in a radial inside of the deformation portion <NUM> to provide a space in which the deformation portion <NUM> may be deformed.

The contact portion <NUM> protrudes radially outward from the deformation portion <NUM>. The contact portion <NUM> is configured to come into contact with the inner surface of the housing <NUM> when the stator <NUM> is coupled to the housing <NUM>. The housing <NUM> presses the contact portion <NUM> of the stator <NUM> when the motor <NUM> is interference fitted into and coupled to the housing <NUM>. When the housing <NUM> presses the contact portion <NUM>, the deformation portion <NUM> is deformed to the cavity <NUM> side together with the contact portion <NUM>.

The contact portion <NUM> protrudes radially outward compared to the portion of the back yoke <NUM> where the stress absorber <NUM> is not formed, and the width C in which the contact portion <NUM> protrudes radially outward from the deformation portion <NUM> is larger than the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. Therefore, when the stator <NUM> is coupled to the housing <NUM>, the housing <NUM> does not press other portion of the core <NUM> except for the stress absorber <NUM> of the stator <NUM>.

The deformation portion <NUM> is deformed to the cavity <NUM> side by the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. The cavity <NUM> has the width D larger than the difference between the outer radius A of the stator <NUM> and the inner radius B of the housing <NUM>. Therefore, even when the deformation portion <NUM> is deformed to the cavity <NUM> side, the deformation portion <NUM> does not press a portion of the back yoke <NUM> on a radial inner side of the cavity <NUM>.

The cavity <NUM> may have the sufficiently large radial width D compared to the protruding width C of the contact portion <NUM>. Therefore, even when a tolerance of the protruding width C of the contact portion <NUM>, a tolerance of the inner radius B of the housing <NUM>, or a tolerance of the outer radius A of the stator <NUM> occurs, the deformation portion <NUM> does not press the portion of the back yoke <NUM> on the radial inner side of the cavity <NUM>.

The deformation portion <NUM> may be formed in a cantilever shape. The cavity <NUM> may be provided such that a central portion of the deformation portion <NUM> is disposed at a central portion of the cavity <NUM>. The contact portion <NUM> may be provided to protrude radially outward from a cantilever end of the deformation portion <NUM>. The core <NUM> of the stator <NUM> may include a plurality of the stress absorbers <NUM> corresponding to the plurality of teeth <NUM>. Each of the stress absorbers <NUM> may be disposed on a radial outer side of each of the teeth <NUM>.

The contact portion <NUM> may be formed to come into surface contact with the inner surface of the housing <NUM> when the deformation portion <NUM> is deformed. When the deformation portion <NUM> is formed in a cantilever shape, the contact portion <NUM> may be formed to protrude higher toward the cantilever end.

Each of the stress absorbers <NUM> may include the at least one deformation portion <NUM>, the at least one contact portion <NUM>, and the at least one cavity <NUM>. The back yoke <NUM> may include one of the deformation portion <NUM>, one of the contact portion <NUM>, and one of the cavity <NUM> for each of the teeth <NUM>.

A circumferential width E' of a contact surface in which the contact portion <NUM> included in the stress absorber <NUM> is in contact with the housing <NUM> may be larger than the radial thickness F of the housing <NUM>. When the circumferential width of the contact surface is large, the stator <NUM> may be more stably fixed to the inner surface of the housing <NUM>.

<FIG> is an enlarged plan view of a portion of a stator of a motor of a compressor according to another example of the disclosure not covered by the present invention, and <FIG> is an enlarged plan view of a portion of a state in which the stator in <FIG> is coupled to a housing.

Referring to <FIG> and <FIG>, the core <NUM> of the stator <NUM> may include the annular back yoke <NUM> in contact with the housing <NUM>, and the tooth <NUM> extending inward from the back yoke <NUM>. The core <NUM> may include a plurality of the teeth <NUM> formed in the circumferential direction on the inner portion thereof facing the outer circumferential surface of the rotor <NUM>. The coil <NUM> may be wound on the teeth <NUM> of the core <NUM>.

The stress absorber <NUM> is configured to absorb a compressive stress transmitted from the housing <NUM> to the stator <NUM> by coupling with the housing <NUM>. The stress absorber <NUM> may include a deformation portion <NUM>, a contact portion <NUM>, and a cavity <NUM>. The deformation portion <NUM> is configured to be compressed and deformed by the housing <NUM> when the stator <NUM> is interference fitted into and coupled to the housing <NUM>. The cavity <NUM> is formed in a radial inner side of the deformation portion <NUM> to provide a space in which the deformation portion <NUM> may be deformed.

The contact portion <NUM> protrudes radially outward compared to the portion of the back yoke <NUM> where the stress absorber <NUM> is not formed, and the width C in which the contact portion <NUM> protrudes radially outward from the deformation portion <NUM> is larger than the difference between the outer radius A (see <FIG>) of the stator <NUM> and the inner radius B (see <FIG>) of the housing <NUM>. Therefore, when the stator <NUM> is coupled to the housing <NUM>, the housing <NUM> does not press other portion of the core <NUM> except for the stress absorber <NUM> of the stator <NUM>.

The deformation portion <NUM> may be formed in a cross beam shape. The cavity <NUM> may be provided such that a central portion of the deformation portion <NUM> is disposed at a central portion of the cavity <NUM>. The deformation portion <NUM> may be disposed such that the center of the deformation portion <NUM> coincides with the center of the cavity <NUM>. The contact portion <NUM> may be provided to protrude radially outward from the central portion of the deformation portion <NUM>. The core <NUM> of the stator <NUM> may include a plurality of the stress absorbers <NUM> corresponding to the plurality of teeth <NUM>. Each of the stress absorbers <NUM> may be disposed on a radial outer side of each of the teeth <NUM>.

Each of the stress absorbers <NUM> may include the at least one deformation portion <NUM>, the at least one contact portion <NUM>, and the at least one cavity <NUM>. The back yoke <NUM> may include one of the deformation portion <NUM>, one of the contact portion <NUM>, and one of the cavity <NUM>, which are arranged such that centers thereof coincide with the center of each of the teeth <NUM> for each of the teeth <NUM>.

The contact portion <NUM> may be formed to come into surface contact with the inner surface of the housing <NUM> when the deformation portion <NUM> is deformed. When the deformation portion <NUM> is formed in a fixed end support beam shape, the contact portion <NUM> may be formed to protrude higher toward a central portion.

A circumferential width of a contact surface in which the at least one contact portion <NUM> included in one of the stress absorber <NUM> is in contact with the housing <NUM> may be larger than the radial thickness F of the housing <NUM>. When the circumferential width of the contact surface is large, the stator <NUM> may be more stably fixed to the inner surface of the housing <NUM>. When one of the stress absorber <NUM> includes one of the contact portion <NUM>, a circumferential width E" of the contact portion <NUM> and the contact surface of the housing <NUM> may be larger than the radial thickness F of the housing <NUM>.

A deformation portion <NUM> may be formed in a cross beam shape. A cavity <NUM> may be provided such that a central portion of a deformation portion <NUM> is disposed at a central portion of the cavity <NUM>. The deformation portion <NUM> may be disposed such that the center of the deformation portion <NUM> coincides with the center of the cavity <NUM>. The contact portion <NUM> may be provided to protrude radially outward from the central portion of the deformation portion <NUM>. The core <NUM> of the stator <NUM> may include a plurality of stress absorbers <NUM> corresponding to the plurality of teeth <NUM>. Each of the stress absorbers <NUM> may be disposed on a radial outer side of each of the teeth <NUM>.

Each of the stress absorbers <NUM> may include the at least one deformation portion <NUM>, the at least one contact portion <NUM>, and the at least one cavity <NUM>. The back yoke <NUM> may include one of the deformation portion <NUM> and one of the cavity <NUM>, which are arranged such that centers thereof coincide with the center of each of the teeth <NUM> for each of the teeth <NUM>. The back yoke <NUM> may include a plurality of the contact portions <NUM> disposed symmetrically with respect to the center of the deformation portion <NUM>.

The contact portion <NUM> may be formed to come into surface contact with the inner surface of the housing <NUM> when the deformation portion <NUM> is deformed. When the deformation portion <NUM> is formed in a fixed end support beam shape and the plurality of contact portions <NUM> is provided, the plurality of contact portions <NUM> may be formed to protrude higher toward a central portion of the deformation portion <NUM>.

A circumferential width of a contact surface in which the at least one contact portion <NUM> included in one of the stress absorber <NUM> is in contact with the housing <NUM> may be larger than the radial thickness F of the housing <NUM>. When the circumferential width of the contact surface is large, the stator <NUM> may be more stably fixed to the inner surface of the housing <NUM>.

When one of the stress absorber <NUM> includes the plurality of contact portions <NUM>, the sum of circumferential widths E‴ of the contact portions <NUM> and the contact surface of the housing <NUM> may be larger than the radial thickness F of the housing <NUM>. That is, when two of the contact portions <NUM> are disposed with respect to the center of each of the teeth <NUM>, each of the contact portions <NUM> may have a contact surface of the circumferential width E‴ exceeding half of the radial thickness F of the housing <NUM>.

<FIG> is a plan view of a stator of a motor of a compressor according to another embodiment of the disclosure.

Referring to <FIG>, the core <NUM> of the stator <NUM> includes the annular back yoke <NUM> in contact with the housing <NUM>, and the tooth <NUM> extending inward from the back yoke <NUM>. The core <NUM> includes a plurality of the teeth <NUM> formed in the circumferential direction on the inner portion thereof facing the outer circumferential surface of the rotor <NUM>. The coil <NUM> is wound on the teeth <NUM> of the core <NUM>.

The function and structure of the stress absorber <NUM> have already been described, so a redundant description is omitted.

According to another embodiment of the disclosure, the number of the stress absorbers <NUM> may not correspond to the number of the teeth <NUM> of the back yoke <NUM>. Specifically, the number of the stress absorbers <NUM> may be less than the number of the teeth <NUM> of the back yoke <NUM>.

Referring to <FIG>, the stator <NUM> may include a groove <NUM>. The groove <NUM> may be formed on the tooth <NUM> on which the stress absorber <NUM> is not formed. According to another embodiment of the disclosure, the stator <NUM> may include three of the grooves <NUM>. Two of the stress absorbers <NUM> may be provided between the respective grooves <NUM>. Unlike illustrated in the drawing, the groove <NUM> may not be provided on the tooth <NUM> on which the stress absorber <NUM> is not provided. In this case, the back yoke <NUM> may be formed in an annular shape with no recessed portion on a radial inner side thereof.

The coupling force between the housing <NUM> and the stator <NUM> may relatively decrease due to the reduced number of the stress absorbers <NUM>, but even if the stress absorber <NUM> is not provided on all the teeth <NUM>, a sufficient coupling force for fixing the stator <NUM> may be provided on an inner side of the housing <NUM>.

The drawing illustrates the stress absorber shown in <FIG>, but is not limited thereto. It is also applicable to the stator including the stress absorbers shown in <FIG>.

Referring to <FIG>, the stator <NUM> may include a groove <NUM>. The groove <NUM> may be formed on the tooth <NUM> on which the stress absorber <NUM> is not formed. According to another embodiment of the disclosure, the stator <NUM> may include four of the grooves <NUM>. The stress absorber <NUM> and the groove <NUM> may be arranged alternately along the circumferential direction of the back yoke <NUM>. <FIG> illustrates that among a total of the nine teeth, the stress absorber is formed on the five teeth and the groove is formed on the four teeth, but is not limited thereto. The number of grooves may be more than the number of stress absorbers, and the groove may not be formed on the tooth on which the stress absorber is not formed.

The coupling force between the housing <NUM> and the stator <NUM> may relatively decrease due to the reduced number of the stress absorbers <NUM>, but even if the stress absorber <NUM> is not provided on all the teeth <NUM>, a sufficient coupling force for fixing the stator <NUM> may be provided on the inner side of the housing <NUM>.

Referring to <FIG>, a stator of a motor of a compressor according to another embodiment of the disclosure may include twelve of the teeth <NUM>. Each of the twelve teeth <NUM> may include a stress absorber <NUM>.

The drawing illustrates the stator including twelve teeth, but is not limited thereto. The number of teeth may be varied according to a design specification. In addition, the drawing illustrates the stress absorber shown in <FIG>, but is not limited thereto. The number of teeth may also be varied for the stators including the stress absorbers shown in <FIG>.

Referring to <FIG>, a stator of a motor of a compressor according to another embodiment of the disclosure may include twelve of the teeth <NUM>. Some of the twelve the teeth <NUM> may include a stress absorber <NUM>, and the other may include the groove <NUM>.

As illustrated in <FIG>, the stator <NUM> may include four of the grooves <NUM>. The grooves <NUM> may be provided at the up, down, left, and right sides of the stator <NUM> in the drawing, respectively. That is, the grooves <NUM> may be arranged every <NUM> degrees along the circumferential direction of the back yoke <NUM>. Two of the stress absorbers <NUM> may be disposed between the groove <NUM> and the groove <NUM>. The groove <NUM> and the groove <NUM> may be arranged to face each other based on the center of the back yoke <NUM>. The stress absorber <NUM> and the stress absorber <NUM> may be arranged to face each other based on the center of the back yoke <NUM>. In other words, the groove <NUM> and the stress absorber <NUM> may be arranged symmetrically.

Referring to <FIG>, a stator of a motor of a compressor according to another embodiment of the disclosure may include twelve of the teeth <NUM>. Some of the twelve teeth <NUM> may include a stress absorber <NUM>, and the other may include the groove <NUM>.

As illustrated in <FIG>, the stator <NUM> may include six of the grooves <NUM>. The groove <NUM> and the stress absorber <NUM> may be arranged alternately along the circumferential direction of the back yoke <NUM>. The stress absorber <NUM> may be disposed between the groove <NUM> and the groove <NUM>. The groove <NUM> may be disposed between the stress absorber <NUM> and the stress absorber <NUM>. Also, the groove <NUM> and the groove <NUM> may be arranged to face each other based on the center of the back yoke <NUM>. Likewise, the stress absorber <NUM> and the stress absorber <NUM> may be arranged to face each other based on the center of the back yoke <NUM>. In other words, the groove <NUM> and the stress absorber <NUM> may be arranged symmetrically.

The stator may include various forms of stress absorbers and grooves not shown in the drawings. In a case where the stress absorber is not formed on all of the teeth of the stator, the groove may be provided in various positions and numbers. As described above, the groove may not be provided on the tooth on which the stress absorber is not formed.

In the above, the motor <NUM> in which the rotor <NUM> is disposed at the inner side of the stator <NUM> has been described, but the embodiments of the disclosure may also be applied to an external rotor motor in which a rotor is disposed at an outer side of a stator.

The stator of the motor includes an annular back yoke and a plurality of teeth extending from the back yoke. The motor may include a plurality of stress absorbers capable of absorbing an external force for fixing the stator. The stress absorber is provided on the side opposite to one side of the back yoke from which the tooth extends.

The stress absorber includes a deformation portion, a cavity, and a contact portion. The deformation portion is configured to be compressed and deformed by an external force. The cavity is configured to provide a space in which the deformation portion may be deformed. The contact portion protrudes from the side opposite to the one side on which the cavity is disposed and may be configured to press the deformation portion by an external force. The contact portion may be disposed at a central portion of the cavity.

The motor may include the plurality of stress absorbers having a number corresponding to a plurality of teeth, and each of the plurality of stress absorbers includes the at least one deformation portion, the at least one contact portion, and the at least one cavity. The deformation portion is formed in the form of a cantilever shape or a fixed end support beam shape.

Claim 1:
A compressor (<NUM>) comprising:
a housing (<NUM>); and
a motor (<NUM>) including:
a stator (<NUM>) configured to be interference fitted into and fixed to an inner circumferential surface of the housing (<NUM>), the stator including an annular back yoke (<NUM>), a plurality of teeth (<NUM>) extending radially inward from the annular back yoke, and a coil (<NUM>) wound on the plurality of teeth, and
a rotor (<NUM>) configured to be rotatable inside the stator (<NUM>),
wherein the annular back yoke (<NUM>) comprises:
first and second deformation portions (<NUM>), each comprising a cantilever extending circumferentially outwards from a centre of at least some of the plurality of teeth, each of the deformation portions (<NUM>) compressed and deformed by the housing (<NUM>) while the stator is interference fitted into the inner circumferential surface of the housing;
wherein each of the first and second deformation portions comprise:
a contact portion (<NUM>) formed at the end of the cantilever which protrudes radially outward from the deformation portion and is in contact with the housing; and
a cavity (<NUM>) formed on a radial inner side of the deformation portion into which the deformation portion is deformed,
wherein the first and second deformation portions and their respective contact portions and cavities are symmetrically arranged with respect to a centre of each of the plurality of teeth to which they are provided.