Patent Description:
In general, a compressor refers to a device configured to compress a working fluid such as air or refrigerant by receiving power from a power generating device such as a motor or a turbine. Specifically, the compressor is widely applied to the overall industry or home appliances, in particular, a vapor compression type refrigeration cycle and the like (hereinafter referred to as a 'refrigeration cycle').

Such a compressor may be divided into a reciprocating compressor, a rotary compressor, and a scroll compressor according to a method of compressing a refrigerant.

The reciprocating compressor is a method in which a compression space is formed between a piston and a cylinder and the piston is linearly reciprocated to compress a fluid, the rotary compressor is a method of compressing a fluid by a roller eccentrically rotated inside the cylinder, and the scroll compressor is a method of compressing a fluid by rotating a pair of spiral scrolls engaged with each other.

Recently, the use of a linear compressor using a linear reciprocating motion without using a crankshaft among reciprocating compressors is gradually increasing. The linear compressor has advantages in that the efficiency of the compressor is improved because the mechanical loss involved in converting the rotational motion into the linear reciprocating motion is small, and the structure is relatively simple.

The linear compressor is configured such that a cylinder is positioned inside a casing forming a closed space to form a compression chamber, and a piston covering the compression chamber reciprocates inside the cylinder. In the linear compressor, processes in which the fluid in the closed space is sucked into the compression chamber when the piston is positioned at the bottom dead center (BDC), and the fluid in the compression chamber is compressed and discharged when the piston is positioned at the top dead center (TDC) are repeated.

A compression unit and a driving unit are installed inside the linear compressor, respectively, and through the movement generated in the driving unit, the compression unit performs a process of compressing and discharging the refrigerant while resonating by a resonance spring.

The piston of the linear compressor sucks the refrigerant into the inside of the casing through the suction pipe while reciprocating at high speed inside the cylinder by the resonance spring, and then repeatedly performs a series of processes of being discharged from the compression space by the forward movement of the piston and moving to the condenser through the discharge pipe.

On the other hand, the linear compressor may be divided into an oil lubrication type linear compressor and a gas type linear compressor according to a lubrication method.

The oil lubrication type linear compressor is configured to store a certain amount of oil inside the casing and lubricate between the cylinder and the piston using the oil.

On the other hand, the gas lubrication type linear compressor is configured to induce a portion of the refrigerant discharged from the compression space between the cylinder and the piston and lubricate between the cylinder and the piston with the gas force of the refrigerant without storing oil inside the casing.

The oil lubrication type linear compressor may suppress overheating of the cylinder and the piston by motor heat or compression heat, etc. as oil having a relatively low temperature is supplied between the cylinder and the piston. Through this, the oil lubrication type linear compressor may suppress an increase in specific volume since the refrigerant passing through the suction passage of the piston is heated while being sucked into the compression chamber of the cylinder, thereby preventing suction loss in advance.

Recently, needs for a subminiature linear compressor is increasing. To this end, the size of the linear motor (driving unit) must be reduced.

Simply, when the size of the linear motor is reduced, there is a problem in that the output of the linear motor is reduced.

In addition, there is a problem in that the distance between the plurality of stator cores or the plurality of core blocks of the outer stator is reduced, and interference with other components occurs. Prior art compressors are known from <CIT> and <CIT>.

An object to be solved by the present disclosure is to provide a driving unit capable of reducing the overall size of a linear compressor by reducing the size of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of reducing the overall height of a linear compressor by reducing the height of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of maintaining a stable output of the driving unit while reducing the height of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of reducing cost by reducing the configuration of the driving unit while maintaining a stable output of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of reducing interference between an oil feeder and a plurality of stator cores while reducing the size of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of reducing interference between a terminal portion and a plurality of stator cores while reducing the size of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of maintaining the overall balance of a linear compressor while reducing the size of the driving unit, and a linear compressor including the same.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of improving the manufacturing efficiency of the driving unit, and a linear compressor including the same since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the magnet coupling hole of the magnet frame.

In addition, an object to be solved by the present disclosure is to provide a driving unit capable of improving the manufacturing efficiency of the driving unit, and a linear compressor including the same since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the supporter coupling hole of the spring supporter.

A driving unit according to the present invention, defined by the appended claims, comprises an inner stator, a bobbin surrounding the inner stator in a circumferential direction, a coil wound on the bobbin, a plurality of stator cores surrounding the bobbin and spaced apart from each other in the circumferential direction, and a plurality of permanent magnets disposed between the inner stator and the plurality of stator cores. The stator cores surrounds the bobbin in the manner of covering at least a portion of respective front and rear surfaces of the bobbin.

A cross section of the bobbin includes a pair of straight portions facing each other and a curved portion connecting the pair of straight portions.

Through this, it is possible to reduce the overall size of the linear compressor by reducing the size of the driving unit.

In addition, the pair of straight portions may be formed in an upper region and a lower region of the bobbin. In this case, the plurality of stator cores may be disposed only on the curved portion.

Through this, it is possible to reduce the overall height of the linear compressor by reducing the height of the driving unit.

Preferably, the plurality of stator cores may be arranged to be substantially symmetric with respect to a virtual plane on which the axis of the inner stator is located.

Preferably, three or more out of the plurality of stator cores, which are disposed at one side of a virtual plane on which the axis of the inner stator is located, are arranged equally spaced apart from each other in the circumferential direction.

In addition, the plurality of stator cores may include first to sixth stator cores spaced apart from each other in the circumferential direction, an angle between a straight line passing through a center of the first stator core and a center of the inner stator and a straight line passing through a center of the second stator core and the center of the inner stator may be <NUM> degrees, an angle between the straight line passing through the center of the second stator core and the center of the inner stator and a straight line passing through a center of the third stator core and the center of the inner stator may be <NUM> degrees, an angle between the straight line passing through the center of the third stator core and the center of the inner stator and a straight line passing through a center of the fourth stator core and the center of the inner stator may be <NUM> degrees, an angle between the straight line passing through the center of the fourth stator core and the center of the inner stator and a straight line passing through a center of the fifth stator core and the center of the inner stator may be <NUM> degrees, an angle between the straight line passing through the center of the fifth stator core and the center of the inner stator and a straight line passing through a center of the sixth stator core and the center of the inner stator may be <NUM> degrees, and an angle between the straight line passing through the center of the sixth stator core and the center of the inner stator and the straight line passing through the center of the first stator core and the center of the inner stator may be <NUM> degrees.

In this case, the plurality of permanent magnets may include first to twelfth permanent magnets spaced apart from each other at the same distance in the circumferential direction, the first and seventh permanent magnets facing each other may face the straight portion, and a central region of the second to sixth permanent magnets and a central region of the eighth to twelfth permanent magnets may face the curved portion.

Through this, it is possible to maintain a stable output of the driving unit while reducing the height of the driving unit.

Preferably, the plurality of permanent magnets may be arranged equally spaced apart from each other in the circumferential direction.

Preferably, the plurality of permanent magnets may be arranged to be substantially symmetric with respect to a virtual plane on which the axis of the inner stator is located.

Preferably, the number of the plurality of permanent magnets is <NUM>*n (n: natural number equal to or greater than <NUM>), and a <NUM>st permanent magnet and a (n+<NUM>)th permanent magnet may face each other and face the pair of straight portions.

Preferably, the number of the plurality of permanent magnets is <NUM>*n (n: natural number equal to or greater than <NUM>), and center regions of all the permanent magnets may face the curved portion.

In addition, the plurality of permanent magnets may include first to tenth permanent magnets spaced apart from each other in the circumferential direction, and a central region of the first to tenth permanent magnets facing each other may face the curved portion.

In this case, an angle between straight lines passing through a center of the first to fifth permanent magnets and a center of the inner stator may be each <NUM> degrees, an angle between a straight line passing through a center of the sixth permanent magnet and the center of the inner stator and a straight line passing through a center of the seventh permanent magnet and the center of the inner stator may be <NUM> degrees, an angle between straight lines passing through a center of the seventh to tenth permanent magnets and the center of the inner stator may be each <NUM> degrees, and an angle between a straight line passing through the center of the tenth permanent magnet and the center of the inner stator and a straight line passing through the center of the first permanent magnet and the center of the inner stator may be <NUM> degrees.

Through this, it is possible to reduce the cost by reducing the configuration of the driving unit while maintaining a stable output of the driving unit.

In addition, the plurality of permanent magnets may include first to eighth permanent magnets spaced apart from each other at the same distance in the circumferential direction, the first and fifth permanent magnets facing each other may face the straight portion, and the second to fourth permanent magnets and the sixth to eighth permanent magnets may face the curved portion.

A linear compressor according to an aspect of the present disclosure for achieving the above object may comprise a frame, a cylinder coupled to the frame, an inner stator disposed on an outer circumferential surface of the cylinder, a bobbin surrounding the inner stator in a circumferential direction, a coil wound on the bobbin, a plurality of stator cores surrounding the bobbin and spaced apart from each other in the circumferential direction, and a plurality of permanent magnets disposed between the inner stator and the plurality of stator cores.

In this case, a cross section of the bobbin may include a pair of straight portions facing each other and a curved portion connecting the pair of straight portions.

In addition, the linear compressor may comprise an oil feeder coupled to the frame, and the straight portion may overlap the oil feeder in an axial direction. In addition, a part of the oil feeder may be disposed between the plurality of stator cores.

Through this, it is possible to reduce the interference between the oil feeder and the plurality of stator cores while reducing the size of the driving unit.

In addition, the linear compressor may comprise a terminal portion coupled to the frame and electrically connected to the coil, and the straight portion may overlap the terminal portion in an axial direction. In this case, a part of the terminal portion may be disposed between the plurality of stator cores.

Through this, it is possible to reduce the interference between the terminal portion and the plurality of stator cores while reducing the size of the driving unit.

In addition, the linear compressor may comprise a stator cover supporting rear surfaces of the plurality of stator cores, a magnet frame in which the plurality of permanent magnets are disposed, a spring supporter coupled to the magnet frame, and a plurality of main front springs, a front of which is disposed on a rear surface of the stator cover and, a rear of which is disposed on the spring supporter.

In this case, the plurality of main front springs may overlap the plurality of stator cores in an axial direction.

Through this, it is possible to maintain the overall balance of the linear compressor while reducing the size of the driving unit.

In addition, the magnet frame may include a magnet seating portion on which the permanent magnet is disposed, a magnet coupling portion extending radially inward from a rear of the magnet seating portion, and a plurality of magnet coupling holes formed in the magnet coupling portion and spaced apart from each other in the circumferential direction, and an imaginary line connecting a central region of the magnet coupling portion and the magnet coupling hole may overlap the plurality of stator cores in the axial direction.

In addition, an imaginary line connecting a central region of the magnet coupling portion and the magnet coupling hole may overlap a space between the plurality of permanent magnets in the axial direction.

Through this, since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the magnet coupling hole of the magnet frame, it is possible to improve the manufacturing efficiency of the driving unit.

In addition, the spring supporter may include a supporter coupling portion disposed at a rear of the magnet frame, a plurality of supporter coupling holes formed in the supporter coupling portion and spaced apart from each other in the circumferential direction, and a plurality of supporter seating portions extending radially from the supporter coupling portion and in which the plurality of main front springs are disposed, and an imaginary line connecting a central region of the supporter coupling portion and the supporter coupling hole may overlap the plurality of stator cores in the axial direction.

In addition, an imaginary line connecting a central region of the supporter coupling portion and the supporter coupling hole may overlap a space between the plurality of permanent magnets in the axial direction.

Through this, since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the supporter coupling hole of the spring supporter, it is possible to improve the manufacturing efficiency of the driving unit.

Through the present disclosure, it is possible to provide a driving unit capable of reducing the overall size of a linear compressor by reducing the size of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of reducing the overall height of a linear compressor by reducing the height of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of maintaining a stable output of the driving unit while reducing the height of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of reducing the cost by reducing the configuration of the driving unit while maintaining a stable output of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of reducing interference between an oil feeder and a plurality of stator cores while reducing the size of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of reducing interference between a terminal portion and a plurality of stator cores while reducing the size of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of maintaining the overall balance of a linear compressor while reducing the size of the driving unit, and a linear compressor including the same.

In addition, through the present disclosure, it is possible to provide a driving unit capable of improving the manufacturing efficiency of the driving unit and a linear compressor including the same since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the magnet coupling hole of the magnet frame.

In addition, through the present disclosure, it is possible to provide a driving unit capable of improving the manufacturing efficiency of the driving unit and a linear compressor including the same since the position of the permanent magnet and the position of the plurality of stator cores can be determined according to the position of the supporter coupling hole of the spring supporter.

Hereinafter, embodiments disclosed in the present disclosure will be described in detail with reference to the accompanying drawings, however, regardless of the reference numerals, the same or similar components will be given the same reference numerals and redundant description thereof will be omitted.

In describing the embodiments disclosed in the present disclosure, when a component is referred to as being "connected" or "accessed" to other component, it may be directly connected or accessed to the other component, however, it may be understood that other components may be present in the middle.

In addition, in describing the embodiments disclosed in the present disclosure, when it is determined that the detailed description of the related known technology may obscure the subject matter of the embodiments disclosed in the present disclosure, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easily understanding the embodiments disclosed in the present disclosure, the technical spirit disclosed in the present disclosure is not limited by the accompanying drawings, and it should be understood that the accompanying drawings include all changes, equivalents, and substitutes included in the spirit and scope of the present disclosure. The directional terms "upper" and "lower" refers to corresponding directions under the scene that a driving unit of the present invention and a compressor including the driving unit is installed in a home appliance product. Further, the term "front" refers to a direction in which a piston connected to the driving unit moves for compression of a gas, and the "rear" refers to the opposite direction.

On the other hand, terms of disclosure may be replaced with terms such as document, specification, description.

<FIG> is a cross-sectional view of a linear compressor according to a first embodiment of the present disclosure. <FIG> and <FIG> are perspective views of a configuration in which a shell of a linear compressor is removed according to a first embodiment of the present disclosure. <FIG> is an exploded perspective view of a configuration in which a shell of a linear compressor is removed according to a first embodiment of the present disclosure.

Hereinafter, a linear compressor <NUM> according to the present disclosure may be described as an example of the linear compressor <NUM> in which a piston performs an operation of sucking and compressing a fluid while linear reciprocating motion, and discharging the compressed fluid.

The linear compressor <NUM> may be a component of a refrigeration cycle, and a fluid compressed in the linear compressor <NUM> may be a refrigerant circulating in the refrigeration cycle. The refrigeration cycle may include a condenser, an expansion device and an evaporator in addition to the compressor. In addition, the linear compressor <NUM> may be used as one component of the cooling system of the refrigerator, and is not limited thereto, and may be widely used throughout the industry.

Referring to <FIG>, the linear compressor <NUM> may include a shell <NUM> and a body accommodated in the shell <NUM>. The body of the linear compressor <NUM> may include a frame <NUM>, a cylinder <NUM> fixed to the frame <NUM>, a piston <NUM> linearly reciprocating inside the cylinder <NUM>, a driving unit <NUM> fixed to the frame <NUM> and providing driving force to the piston <NUM>, and the like. Here, the cylinder <NUM> and the piston <NUM> may be referred to as compression units <NUM> and <NUM>.

The shell <NUM> may include a lower shell and an upper shell coupled to an upper portion of the lower shell. The inside of the shell <NUM> may form a closed space. Also, the upper shell and the lower shell may be integrally formed.

The shell <NUM> may be formed of a thermally conductive material. Through this, heat generated in the inner space of the shell <NUM> may be quickly radiated to the outside.

On the lower side of the shell <NUM>, legs (not shown) may be coupled. The legs may be coupled to a base of a product on which the linear compressor <NUM> is installed. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. As another example, the product may include an outdoor unit of an air conditioner, and the base may include a base of the outdoor unit.

The shell <NUM> may have a cylindrical shape, and may form an arrangement lying in a transverse direction or an arrangement lying in an axial direction. Based on <FIG>, the shell <NUM> may extend long in the transverse direction, and may have a rather low height in a radial direction. That is, since the linear compressor <NUM> may have a low height, for example, when the linear compressor <NUM> is installed in the machine room base of the refrigerator, there is an advantage that the height of the machine room can be reduced.

In the first embodiment of the present disclosure, the axial direction may be understood to mean a horizontal direction based on <FIG>, and the radial direction may be understood to mean a vertical direction based on <FIG>. In addition, in the first embodiment of the present disclosure, a front may be interpreted to mean a left direction based on <FIG>, and a rear may be interpreted to mean a right direction based on <FIG>.

In addition, the longitudinal central axis of the shell <NUM> coincides with the central axis of the linear compressor <NUM> to be described later, and the central axis of the linear compressor <NUM> coincides with the central axis of the cylinder <NUM> and the piston <NUM> of the linear compressor <NUM>.

A terminal (not shown) may be installed on the outer surface of the shell <NUM>. The terminal may transmit external power to the driving unit <NUM> of the linear compressor <NUM> through a terminal portion <NUM>. Specifically, the terminal may be connected to a lead wire of a coil wound around an outer stator <NUM>.

The linear compressor <NUM> may include a plurality of pipes <NUM> and <NUM> provided in the shell <NUM>, and capable of sucking, discharging, or injecting the refrigerant.

The plurality of pipes <NUM> and <NUM> may include a suction pipe <NUM> for allowing the refrigerant to be sucked into the linear compressor <NUM>, and a loop pipe <NUM> for allowing the compressed refrigerant to be discharged from the linear compressor <NUM>.

For example, the suction pipe <NUM> may be coupled to the rear of the shell <NUM>. The refrigerant may be sucked into the linear compressor <NUM> along the axial direction through the suction pipe <NUM>. The loop pipe <NUM> may be coupled to the front of the shell <NUM>. The refrigerant sucked through the suction pipe <NUM> may be compressed while flowing in the axial direction. And the compressed refrigerant may be discharged through the loop pipe <NUM>. The suction pipe <NUM> may be coupled to the rear of the lower shell, and the loop pipe <NUM> may be coupled to the front of the lower shell.

The linear compressor <NUM> may include a bearing means for reducing friction between the cylinder <NUM> and the piston <NUM>. The bearing means may be oil bearings or gas bearings. Alternatively, a mechanical bearing may be used as the bearing means.

The body of the linear compressor <NUM> may be elastically supported by support springs <NUM> and <NUM> installed in the lower inner side of the shell <NUM>. The support springs <NUM> and <NUM> may include a front support spring <NUM> for supporting the front of the body and a rear support spring <NUM> for supporting the rear of the body. The support springs <NUM> and <NUM> may include coil springs. The support springs <NUM> and <NUM> may absorb vibrations and shocks generated according to the reciprocating motion of the piston <NUM> while supporting the internal components of the body of the linear compressor <NUM>.

The frame <NUM> includes a body portion <NUM> supporting an outer circumferential surface of the cylinder <NUM>, and a first flange portion <NUM> connected to one side of the body portion <NUM> and supporting the driving unit <NUM>. The frame <NUM> may be elastically supported with respect to the shell <NUM> by the support springs <NUM> and <NUM> together with the driving unit <NUM> and the cylinder <NUM>.

The body portion <NUM> may surround the outer circumferential surface of the cylinder <NUM>. The body portion <NUM> may be formed in a cylindrical shape. The first flange portion <NUM> may be formed to extend radially from the front end of the body portion <NUM>.

The cylinder <NUM> may be coupled to an inner circumferential surface of the body portion <NUM>. The body portion <NUM> may be penetrated by an inner stator <NUM>. For example, the cylinder <NUM> may be fixed by press fitting on the inner circumferential surface of the body portion <NUM>, and the inner stator <NUM> may be fixed to the outer circumferential surface of the cylinder <NUM> passing through the body portion <NUM>.

The outer stator <NUM> may be coupled to the rear surface of the first flange portion <NUM>, and a discharge cover <NUM> may be coupled to the front surface of the first flange portion <NUM>. For example, the outer stator <NUM> and the discharge cover <NUM> may be fixed through a mechanical coupling means.

An oil hole forming a part of an oil bearing may be formed on an outer circumferential surface of the first flange portion <NUM>, and a first bearing communication hole penetrating from the bearing inlet groove to the inner circumferential surface of the body portion <NUM> may be formed on an outer circumferential surface of the first flange portion <NUM>. The first bearing communication hole may communicate with a second bearing communication hole of the cylinder <NUM>. The first bearing communication hole and the second bearing communication hole may be formed to be inclined toward an inner circumferential surface of the cylinder <NUM>. The second bearing communication hole of the cylinder <NUM> may communicate with an oil groove formed on the inner circumferential surface of the cylinder <NUM>. The oil groove of the cylinder <NUM> may be formed in an annular shape having a predetermined depth and an axial length on the inner circumferential surface of the cylinder <NUM>.

Through an oil feeder <NUM>, the oil (O) stored on the bottom surface of the shell <NUM> may sequentially pass through the oil hole, the first bearing communication hole, the second bearing communication hole, and the oil groove, and may be supplied between the inner circumferential surface of the cylinder <NUM> and the outer circumferential surface of the piston <NUM>.

Meanwhile, the frame <NUM> and the cylinder <NUM> may be formed of aluminum or an aluminum alloy material.

The cylinder <NUM> may be formed in a cylindrical shape in which both ends are open. The piston <NUM> may be inserted through the rear end of the cylinder <NUM>. The front end of the cylinder <NUM> may be closed through the discharge cover <NUM>.

A discharge valve <NUM> may be disposed between the front end of the piston <NUM> and the discharge cover <NUM> and the cylinder <NUM>. A compression space P may be formed between the front end of the piston <NUM>, the discharge valve <NUM>, and the cylinder <NUM>. Here, the front end of the piston <NUM> may be referred to as a head portion. The compression space P may increase in volume when the piston <NUM> moves backward, and may decrease in volume as the piston <NUM> moves forward. That is, the refrigerant introduced into the compression space P may be compressed while the piston <NUM> moves forward and discharged through the discharge valve <NUM>.

The cylinder <NUM> may include a second flange portion disposed at the front end. The second flange portion may be bent outwardly of the cylinder <NUM>. The second flange portion may extend in an outer circumferential direction of the cylinder <NUM>. The second flange portion of the cylinder <NUM> may be coupled to the frame <NUM>.

On the other hand, an oil bearing means capable of lubricating oil between the cylinder <NUM> and the piston <NUM> by supplying oil to an interval between the outer circumferential surface of the piston <NUM> and the inner circumferential surface of the cylinder <NUM> may be provided. The oil between the cylinder <NUM> and the piston <NUM> may reduce friction generated between the piston <NUM> and the cylinder <NUM>.

The piston <NUM> is inserted into the open end of the rear of the cylinder <NUM>, and is provided to seal the rear of the compression space (P).

The piston <NUM> may include a head portion and a guide portion. The head portion may be formed in a disk shape. The head portion may be partially open. The head portion may partition the compression space (P). The guide portion may extend rearward from the outer circumferential surface of the head portion. The guide portion may be formed in a rough cylindrical shape. The guide portion may be hollow inside, and the front of which may be partially closed by the head portion. The rear of the guide portion may be opened and connected to a muffler unit <NUM>. The head portion may be provided as a separate member coupled to the guide portion. Alternatively, the head portion and the guide portion may be integrally formed.

The piston <NUM> may include a suction port. The suction port may pass through the head portion. The suction port may extend in an axial direction of the piston <NUM>. The suction port may communicate with a suction space inside the piston <NUM> and the compression space (P). For example, the refrigerant flowing into the suction space inside the piston <NUM> may pass through the suction port and may be sucked into the compression space P between the piston <NUM> and the cylinder <NUM>.

A plurality of suction ports may be formed in any one or more directions of a radial direction and a circumferential direction of the head portion.

A suction valve <NUM> for selectively opening and closing the suction port may be mounted on the head of the piston <NUM> adjacent to the compression space P. The suction valve <NUM> may open or close the suction port by operating by elastic deformation. That is, the suction valve <NUM> may be elastically deformed to open the suction port by the pressure of the refrigerant flowing into the compression space P through the suction port.

The piston <NUM> may be connected to a permanent magnet <NUM>. The piston <NUM> may reciprocate in the front-rear direction according to the movement of the permanent magnet <NUM>. The inner stator <NUM> and the cylinder <NUM> may be disposed between the permanent magnet <NUM> and the piston <NUM>. The permanent magnet <NUM> and the piston <NUM> may be connected to each other by a magnet frame <NUM> formed by bypassing the cylinder <NUM> and the inner stator <NUM> to the rear.

The muffler unit <NUM> may be coupled to the rear of the piston <NUM> to reduce noise generated while the refrigerant is sucked into the piston <NUM>. The refrigerant sucked through the suction pipe <NUM> may flow into the suction space <NUM> inside the piston <NUM> through the muffler unit <NUM>.

A discharge valve spring <NUM> may be provided on the front side of the discharge valve <NUM> to elastically support the discharge valve <NUM>. The discharge valve <NUM> may selectively discharge the refrigerant compressed in the compression space P. Here, the compression space P means a space formed between the suction valve <NUM> and the discharge valve <NUM>.

The discharge valve <NUM> may be disposed to be supported by the cylinder <NUM>. The discharge valve <NUM> may selectively open and close the front opening of the cylinder <NUM>. The discharge valve <NUM> may open or close the compression space P by operating by elastic deformation. The discharge valve <NUM> may be elastically deformed to open the compression space P by the pressure of the refrigerant flowing into the discharge space through the compression space P.

The discharge valve spring <NUM> may be provided between the discharge valve <NUM> and the discharge cover <NUM> to provide an elastic force in the axial direction. The discharge valve spring <NUM> may be provided as a compression coil spring, or may be provided as a leaf spring in consideration of occupied space or reliability.

When the pressure in the compression space P is equal to or greater than the discharge pressure, the discharge valve spring <NUM> may be deformed forward to open the discharge valve <NUM>, and the refrigerant may be discharged from the compression space P and discharged to the discharge space inside the discharge cover <NUM>. When the discharge of the refrigerant is completed, the discharge valve spring <NUM> may provide a restoring force to the discharge valve <NUM> to close the discharge valve <NUM>.

A process in which the refrigerant flows into the compression space P through the suction valve <NUM> and the refrigerant in the compression space P is discharged to the discharge space through the discharge valve <NUM> will be described as follows.

In the process of the piston <NUM> reciprocating and linear motion inside the cylinder <NUM>, when the pressure of the compression space P becomes less than a predetermined suction pressure, the suction valve <NUM> is opened and the refrigerant is sucked into the compression space P. On the other hand, when the pressure in the compression space P exceeds the predetermined suction pressure, the refrigerant in the compression space P is compressed in a state in which the suction valve <NUM> is closed.

On the other hand, when the pressure in the compression space (P) is greater than or equal to a predetermined discharge pressure, the discharge valve spring <NUM> is deformed forward and opens the discharge valve <NUM> connected thereto, and the refrigerant is discharged from the compression space P to the discharge space inside the discharge cover <NUM>. When the discharge of the refrigerant is completed, the discharge valve spring <NUM> provides a restoring force to the discharge valve <NUM>, and the discharge valve <NUM> is closed to seal the front of the compression space P.

The discharge cover <NUM> may be installed in front of the compression space P to form a discharge space for accommodating the refrigerant discharged from the compression space P, and coupled to the front of the cylinder <NUM> and / or the frame <NUM> to reduce noise generated while the refrigerant is discharged from the compressed space P. The discharge cover <NUM> may be coupled to the front end of the cylinder <NUM> while accommodating the discharge valve <NUM>.

In addition, a gasket for insulation and an O-ring for suppressing leakage of the refrigerant in the discharge space may be provided between the discharge cover <NUM> and the front end of the cylinder <NUM>.

The discharge cover <NUM> may be formed of a thermally conductive material. Accordingly, when a high-temperature refrigerant flows into the discharge cover <NUM>, the heat of the refrigerant is transferred to the shell <NUM> through the discharge cover <NUM> to be radiated to the outside of the compressor.

The discharge cover <NUM> may be formed of a single discharge cover, or a plurality of discharge covers may be arranged to communicate sequentially. When the discharge cover <NUM> is provided with the plurality of discharge covers, the discharge space may include a plurality of space portions partitioned by each discharge cover. The plurality of space portions may be disposed in the front-rear direction and may communicate with each other. Accordingly, while the refrigerant discharged from the compression space P passes through the plurality of discharge spaces in turn, the discharge noise may be attenuated, and may be discharged to the outside of the shell <NUM> through the loop pipe <NUM>.

The driving unit <NUM> may include the outer stator <NUM> disposed to surround the body portion <NUM> of the frame <NUM> between the shell <NUM> and the frame <NUM>, the inner stator <NUM> disposed to surround the cylinder <NUM> between the outer stator <NUM> and the cylinder <NUM>, and the permanent magnet <NUM> disposed between the outer stator <NUM> and the inner stator <NUM>. The driving unit <NUM> may be referred to as a 'linear motor'.

The outer stator <NUM> may be coupled to the rear of the first flange portion <NUM> of the frame <NUM>, and the inner stator <NUM> may be coupled to the outer circumferential surface of the cylinder <NUM>. In addition, the inner stator <NUM> may be disposed to be spaced apart from the inside of the outer stator <NUM>, and the permanent magnet <NUM> may be disposed in a space between the outer stator <NUM> and the inner stator <NUM>.

A winding coil <NUM> may be mounted on the outer stator <NUM>, and the permanent magnet <NUM> may be configured as a single magnet having one pole, or may be configured by combining a plurality of magnets having three poles.

The outer stator <NUM> may include a coil winding body <NUM> surrounding the axial direction in the circumferential direction and a stator core <NUM> stacked while surrounding the coil winding body <NUM>. The coil winding body <NUM> may include a bobbin <NUM> having a hollow cylindrical shape and a coil <NUM> wound in a circumferential direction of the bobbin <NUM>. Alternatively, the coil winding body <NUM> may include a bobbin extending inside the stator core <NUM> and a coil wound around the bobbin. The cross-section of the coil <NUM> may be formed in a circular or polygonal shape, for example, may have a hexagonal shape. In the stator core <NUM>, a plurality of lamination sheets may be radially stacked, and a plurality of lamination blocks may be stacked along a circumferential direction.

The front side of the outer stator <NUM> may be supported by the first flange portion <NUM> of the frame <NUM>, and the rear side may be supported by a stator cover <NUM>. For example, the outer stator <NUM> may be supported on the front surface of the stator cover <NUM>, and a back cover <NUM> may be coupled to the rear surface of the stator cover <NUM>.

The inner stator <NUM> may be configured by stacking a plurality of laminations on the outer circumferential surface of the cylinder <NUM> in a radial direction.

The permanent magnet <NUM> may be supported by coupling one side of the permanent magnet to the magnet frame <NUM>. The magnet frame <NUM> has a rough cylindrical shape and may be disposed to be inserted into a space between the outer stator <NUM> and the inner stator <NUM>. In addition, the magnet frame <NUM> may be coupled to the rear side of the piston <NUM> to be provided to move together with the piston <NUM>.

For example, the rear end of the magnet frame <NUM> may be bent and extended inward in the radial direction to be coupled to the rear of the piston <NUM>.

When a current is applied to the driving unit <NUM>, a magnetic flux may be formed in the winding coil, and electromagnetic force is generated by the interaction between the magnetic flux formed in the winding coil of the outer stator <NUM> and the magnetic flux formed by the permanent magnet <NUM>, so that the permanent magnet <NUM> may move. Also, the piston <NUM> connected to the magnet frame <NUM> may reciprocate in the axial direction integrally with the permanent magnet <NUM> at the same time as the reciprocating movement of the permanent magnet <NUM> in the axial direction.

Meanwhile, the driving unit <NUM> and the compression units <NUM> and <NUM> may be supported in the axial direction by a main rear spring <NUM>. The main rear spring <NUM> may be a coil spring extending in the axial direction or the horizontal direction. The front end of the main rear spring <NUM> may support the muffler unit <NUM> seated on the step portion of the piston <NUM>, and the rear end of the main rear spring <NUM> may be supported by a back cover <NUM> coupled to the rear surface of the stator cover <NUM>. The main rear spring <NUM> may surround the outer diameter of the muffler unit <NUM>.

The rear surface of the stator cover <NUM> may be axially supported by a main front spring <NUM> mounted on a spring supporter <NUM> coupled to the muffler unit <NUM>. The main front spring <NUM> may be a coil spring extending in the axial direction or the horizontal direction. The front end of the main front spring <NUM> may be seated on the rear surface of the stator cover <NUM>, and the rear end of the main front spring <NUM> may be supported by the spring supporter <NUM>. The central region of the main front spring <NUM> may be located axially forward than the central region of the main rear spring <NUM>. The main front spring <NUM> may include a plurality of main front springs <NUM> that are spaced apart in the circumferential direction. In the embodiment of the present disclosure, the main front spring <NUM> is described as an example consisting of four coil springs spaced at equal intervals in the circumferential direction, but the number of the plurality of main front springs <NUM> may be variously changed.

The operation of the linear compressor <NUM> described above is as follows.

First, when a current is applied to the driving unit <NUM>, a magnetic flux may be formed in the outer stator <NUM> by the current flowing in the coil. The magnetic flux formed in the outer stator <NUM> may generate an electromagnetic force, and the permanent magnet <NUM> may reciprocate linearly by the generated electromagnetic force. This electromagnetic force may be generated in a direction (forward direction) in which the piston <NUM> is directed toward the top dead center (TDC) during the compression stroke, and may be generated alternately in the direction (rear direction) in which the piston <NUM> is directed toward the bottom dead center (BDC) during the suction stroke. That is, the driving unit <NUM> may generate thrust, which is a force that pushes the permanent magnet <NUM> and the piston <NUM> in a moving direction.

The piston <NUM> reciprocating linearly within the cylinder <NUM> may repeatedly increase or decrease the volume of the compression space P.

When the piston <NUM> moves in a direction (rear direction) to increase the volume of the compression space P, the pressure of the compression space P may decrease. Accordingly, the suction valve <NUM> mounted in front of the piston <NUM> may be opened, and the refrigerant staying in the suction space <NUM> may be sucked into the compression space P along the suction port <NUM>. This suction stroke may proceed until the piston <NUM> is positioned at the bottom dead center by maximally increasing the volume of the compression space P.

The piston <NUM> that has reached the bottom dead center may perform the compression stroke while moving in a direction (forward direction) in which the movement direction is changed to decrease the volume of the compression space P. During the compression stroke, the suctioned refrigerant may be compressed while the pressure of the compression space P is increased. When the pressure of the compression space P reaches a set pressure, the discharge valve <NUM> may be pushed by the pressure of the compression space P and the refrigerant may be discharged into the discharge space. This compression stroke may be continued while the piston <NUM> moves to top dead center at which the volume of the compression space P is minimized.

As the suction stroke and the compression stroke of the piston <NUM> are repeated, the refrigerant introduced into the linear compressor <NUM> through the suction pipe <NUM> may be introduced into the piston <NUM> via the muffler unit <NUM>, and the refrigerant inside the piston <NUM> may be introduced into the compression space P inside the cylinder <NUM> during the suction stroke of the piston <NUM>. After the refrigerant in the compression space P is compressed during the compression stroke of the piston <NUM> and discharged to the discharge space, a flow discharged to the outside of the linear compressor <NUM> through the loop pipe <NUM> may be formed.

<FIG> is a perspective view of a driving unit of a linear compressor according to a first embodiment of the present disclosure. <FIG> is a front view of a driving unit of a linear compressor according to a first embodiment of the present disclosure. <FIG> are perspective views of a configuration in which a shell of a linear compressor is removed according to a first embodiment of the present disclosure. <FIG> is an exploded perspective view of a driving unit, a magnet frame, and a spring supporter of a linear compressor according to a first embodiment of the present disclosure. <FIG> is a rear view of a driving unit of a linear compressor and a main front spring according to a first embodiment of the present disclosure.

Referring to <FIG>, the driving unit <NUM> according to a first embodiment of the present disclosure may include the inner stator <NUM>, the bobbin <NUM>, the coil <NUM>, the stator core <NUM>, and the permanent magnet <NUM>, but may be implemented except for some of these configurations, and does not exclude additional configurations.

The inner stator <NUM> may be formed in a cylindrical shape. In the inner stator <NUM>, a plurality of lamination sheets may be stacked in the radial direction. The inner stator <NUM> may be disposed radially inside the permanent magnet <NUM>.

The bobbin <NUM> may surround the inner stator <NUM> in a circumferential direction. The bobbin <NUM> may be formed in a cylindrical shape with an opening formed therein as a whole. The coil <NUM> may be wound in a groove formed on the outer circumferential surface of the bobbin <NUM>.

A cross section of the bobbin <NUM> may include a pair of straight portions 444a and 444c facing each other and curved portions 444b and 444d connecting the pair of straight portions 444a and 444c. Through this, it is possible to reduce the overall size of the linear compressor by reducing the size of the driving unit <NUM>.

The straight portions 444a and 444c may be formed in an upper region and a lower region of the bobbin <NUM>. For example, the bobbin <NUM> may include a first straight portion 444a positioned on the upper portion, a first curved portion 444b connected to the right side of the first straight portion 444a and having a first radius of curvature, a second straight portion 444c connected to the first curved portion 444b and positioned below the bobbin <NUM>, and a second curved portion 444d connected to the left side of the second straight portion 444c and having the first radius of curvature. Alternatively, the first curved portion 444b and the second curved portion 444d may not have a constant radius of curvature. Through this, it is possible to reduce the overall height of the linear compressor by reducing the height of the driving unit <NUM>.

The widths of the straight portions 444a and 444c and the widths of the curved portions 444b and 444d may be the same as each other. The stator core <NUM> may not be disposed on the straight portions 444a and 444c. The stator core <NUM> may be disposed on the curved portions 444b and 444d.

The stator core <NUM> may surround the bobbin <NUM>. The stator core <NUM> may not be disposed on the straight portions 444a and 444c, but may be disposed only on the curved portions 444b and 444d. Through this, it is possible to reduce the overall height of the linear compressor by reducing the height of the driving unit <NUM>.

The stator core <NUM> may include a plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f. The plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f may be spaced apart from each other in the circumferential direction. In this case, the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f may not be disposed on the straight portions 444a and 444c, but may be disposed only on the curved portions 444b and 444d. The plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f may be formed to have the same shape as each other. Through this, it is possible to reduce the overall height of the linear compressor by reducing the height of the driving unit <NUM>.

The plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f may include a first stator core 448a, a second stator core 448b, a third stator core 448c, a fourth stator core 448d, a fifth stator core 448e, and a sixth stator core 448f. In the first embodiment of the present disclosure, the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f are described as an example of six, but the number of the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f may be variously changed according to the size of the linear compressor <NUM>.

An angle between a straight line passing through the center of the first stator core 448a and the center of the inner stator <NUM> and a straight line passing through the center of the second stator core 448b and the center of the inner stator <NUM> may be <NUM> degrees. An angle between the straight line passing through the center of the second stator core 448b and the center of the inner stator <NUM> and a straight line passing through the center of the third stator core 448c and the center of the inner stator <NUM> may be <NUM> degrees. An angle between the straight line passing through the center of the third stator core 448c and the center of the inner stator <NUM> and a straight line passing through the center of the fourth stator core 448d and the center of the inner stator <NUM> may be <NUM> degrees. An angle between the straight line passing through the center of the fourth stator core 448d and the center of the inner stator <NUM> and a straight line passing through the center of the fifth stator core 448e and the center of the inner stator <NUM> may be <NUM> degrees. An angle between the straight line passing through the center of the fifth stator core 448e and the center of the inner stator <NUM> and a straight line passing through the center of the sixth stator core 448f and the center of the inner stator <NUM> may be <NUM> degrees. An angle between the straight line passing through the center of the sixth stator core 448f and the center of the inner stator <NUM> and the straight line passing through the center of the first stator core 448a and the center of the inner stator <NUM> may be <NUM> degrees. Through this, it is possible to maintain a stable output of the driving unit <NUM> while reducing the height of the driving unit <NUM>.

The permanent magnet <NUM> may be disposed between the inner stator <NUM> and the plurality of stator cores <NUM>. The permanent magnet <NUM> may be disposed between the inner stator <NUM> and the bobbin <NUM>.

The permanent magnet <NUM> may include a plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM>. The plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> may be spaced apart from each other in the circumferential direction. The plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> may have the same circumferential distance and angle as each other. The plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> may be formed to have the same shape as each other.

The plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> may include a first permanent magnet 460a, a second permanent magnet 460b, a third permanent magnet 460c, a fourth permanent magnet 460d, a fifth permanent magnet 460e, a sixth permanent magnet 460f, a seventh permanent magnet <NUM>, and an eighth permanent magnet <NUM>, a ninth permanent magnet 460i, a tenth permanent magnet 460j, an eleventh permanent magnet <NUM>, and a twelfth permanent magnet <NUM>. In the first embodiment of the present disclosure, the number of the plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> will be described as an example of <NUM>.

The first permanent magnet 460a and the seventh permanent magnet <NUM> may face each other. The first permanent magnet 460a and the seventh permanent magnet <NUM> may face only the straight portions 444a and 444c. The first permanent magnet 460a and the seventh permanent magnet <NUM> may not face the stator core <NUM>.

A central region of the second permanent magnet 460b, the third permanent magnet 460c, the fourth permanent magnet 460d, the fifth permanent magnet 460e, the sixth permanent magnet 460f, the eighth permanent magnet <NUM>, the ninth permanent magnet 460i, the tenth permanent magnet 460j, the eleventh permanent magnet <NUM>, and the twelfth permanent magnet <NUM> may face the curved portions 444b and 444d. The second permanent magnet 460b, the third permanent magnet 460c, the fourth permanent magnet 460d, the fifth permanent magnet 460e, the sixth permanent magnet 460f, the eighth permanent magnet <NUM>, the ninth permanent magnet 460i, the tenth permanent magnet 460j, the eleventh permanent magnet <NUM>, and the twelfth permanent magnet <NUM> may face the stator core <NUM>.

Through this, it is possible to maintain a stable output of the driving unit <NUM> while reducing the height of the driving unit <NUM>.

Referring to <FIG>, the terminal portion <NUM> may be coupled to the frame <NUM> and electrically connected to the coil <NUM>. At least a portion of the terminal portion <NUM> may overlap the first straight portion 444a in the axial direction. At least a portion of the terminal portion <NUM> may be disposed between the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f. The terminal portion <NUM> may not overlap the stator core <NUM> in the axial direction.

Through this, it is possible to reduce the interference between the terminal portion <NUM> and the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f while reducing the size of the driving unit <NUM>.

Referring to <FIG>, an oil feeder <NUM> may be coupled to the frame <NUM>. At least a portion of the oil feeder <NUM> may overlap the second straight portion 444c in the axial direction. At least the portion of the oil feeder <NUM> may be disposed between the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f. The oil feeder <NUM> may not overlap the stator core <NUM> in the axial direction.

Through this, it is possible to reduce the interference between the oil feeder <NUM> and the plurality of stator cores 448a, 448b, 448c, 448d, 448e, and 448f while reducing the size of the driving unit <NUM>.

Referring to <FIG>, the magnet frame <NUM> may include a magnet seating portion <NUM> on which the permanent magnet is disposed, a magnet coupling portion <NUM> extending radially inward from a rear of the magnet seating portion <NUM>, and a plurality of magnet coupling holes <NUM> formed in the magnet coupling portion <NUM> and spaced apart from each other in the circumferential direction.

An imaginary line L2 connecting a central region of the magnet coupling portion <NUM> and the magnet coupling hole <NUM> may overlap the stator core <NUM> in the axial direction C. An imaginary line L2 connecting the central region of the magnet coupling portion <NUM> and the magnet coupling hole <NUM> may overlap a space between the plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> in the axial direction C.

Through this, since the position of the permanent magnet <NUM> and the position of the stator core <NUM> can be determined according to the position of the magnet coupling hole <NUM> of the magnet frame <NUM>, it is possible to improve the manufacturing efficiency of the driving unit <NUM>.

In addition, the spring supporter <NUM> may include a supporter coupling portion <NUM> disposed at a rear of the magnet frame <NUM>, a plurality of supporter coupling holes <NUM> formed in the supporter coupling portion <NUM> and spaced apart from each other in the circumferential direction, a plurality of supporter seating portions <NUM> extending radially from the supporter coupling portion <NUM> and in which the plurality of main front springs <NUM> are disposed, and a protrusion <NUM> protruding forward from the plurality of supporter seating portions <NUM> and disposed inside the main front spring <NUM>.

An imaginary line L1 connecting a central region of the supporter coupling portion <NUM> and the supporter coupling hole <NUM> may overlap the stator cores <NUM> in the axial direction C. An imaginary line L2 connecting a central region of the supporter coupling portion <NUM> and the supporter coupling hole <NUM> may overlap a space between the plurality of permanent magnets 460a, 460b, 460c, 460d, 460e, 460f, <NUM>, <NUM>, 460i, 460j, <NUM>, and <NUM> in the axial direction C.

Through this, since the position of the permanent magnet <NUM> and the position of the stator core <NUM> can be determined according to the position of the supporter coupling hole <NUM> of the spring supporter <NUM>, it is possible to improve the manufacturing efficiency of the driving unit <NUM>.

Referring to <FIG>, the plurality of main front springs <NUM> may overlap the stator core <NUM> in the axial direction. For example, the plurality of main front springs <NUM> may include the first stator core 448a, the third stator core 448c, the fourth stator core 448d, and the sixth stator core 448f in the axial direction. The plurality of main front springs <NUM> may overlap the curved portions 444b and 444d in the axial direction.

Through this, it is possible to maintain the overall balance of the linear compressor <NUM> while reducing the size of the driving unit <NUM>.

<FIG> is a front view of a driving unit of a linear compressor according to a second embodiment of the present disclosure.

The detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the second embodiment of the present disclosure, which is not described below, may be understood to be the same as the detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the first embodiment of the present disclosure.

Referring to <FIG>, the bobbin <NUM> of the driving unit <NUM> of the linear compressor <NUM> according to the second embodiment of the present disclosure may be formed in a cylindrical shape. That is, it may be understood that the straight portions 444a and 444c of the bobbin <NUM> according to the first embodiment are replaced with curved portions.

<FIG> is a front view of a driving unit of a linear compressor according to a third embodiment of the present disclosure.

The detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the third embodiment of the present disclosure, which is not described below, may be understood to be the same as the detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the first embodiment of the present disclosure.

Referring to <FIG>, the bobbin <NUM> of the driving unit <NUM> of the linear compressor <NUM> according to the third embodiment of the present disclosure may be formed in a cylindrical shape. That is, it may be understood that the straight portions 444a and 444c of the bobbin <NUM> according to the first embodiment are replaced with curved portions.

The permanent magnet <NUM> may include first to tenth permanent magnets spaced apart from each other in the circumferential direction. It may be understood that the first permanent magnet is disposed on the upper right side of <FIG>, and the second to tenth permanent magnets are sequentially disposed in a clockwise direction with respect to the first permanent magnet.

In this case, an angle between a straight lines passing through the center of the first to fifth permanent magnets and the center of the inner stator <NUM> may be <NUM> degrees, respectively. An angle between a straight line passing through the center of the sixth permanent magnet and the center of the inner stator <NUM> and a straight line passing through the center of the seventh permanent magnet and the center of the inner stator <NUM> may be <NUM> degrees. An angle between a straight lines passing through the center of the seventh to tenth permanent magnets and the center of the inner stator <NUM> may be <NUM> degrees, respectively. An angle between a straight line passing through the center of the tenth permanent magnet and the center of the inner stator <NUM> and a straight line passing through the center of the first permanent magnet and the center of the inner stator <NUM> may be <NUM> degrees.

Through this, it is possible to reduce the cost by reducing the configuration of the driving unit <NUM> while maintaining a stable output of the driving unit <NUM>.

The number and arrangement of the plurality of permanent magnets <NUM> according to the third embodiment of the present disclosure may be applied to the number and arrangement of the plurality of permanent magnets <NUM> according to the first embodiment of the present disclosure. In this case, the central regions of the first to tenth permanent magnets facing each other may face only the curved portions 444b and 444d and may not face the straight portions 444a and 444c.

<FIG> is a front view of a driving unit of a linear compressor according to a fourth embodiment of the present disclosure.

A detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the fourth embodiment of the present disclosure, which is not described below, may be understood to be the same as a detailed configuration of the driving unit <NUM> of the linear compressor <NUM> according to the first embodiment of the present disclosure.

Referring to <FIG>, the bobbin <NUM> of the driving unit <NUM> of the linear compressor <NUM> according to the fourth embodiment of the present disclosure may be formed in a cylindrical shape. That is, it may be understood that the straight portions 444a and 444c of the bobbin <NUM> according to the first embodiment are replaced with curved portions.

The permanent magnet <NUM> may include first to eighth permanent magnets spaced apart from each other at the same distance in the circumferential direction. It may be understood that the first permanent magnet is disposed in the upper portion of <FIG>, and the second to tenth permanent magnets are sequentially disposed in a clockwise direction with respect to the first permanent magnet. The second to fourth permanent magnets and the sixth to eighth permanent magnets may face the stator core <NUM>, respectively. The first permanent magnet and the fifth permanent magnet may not face the stator core <NUM>.

The number and arrangement of the plurality of permanent magnets <NUM> according to the fourth embodiment of the present disclosure may be applied to the number and arrangement of the plurality of permanent magnets <NUM> according to the first embodiment of the present disclosure. In this case, the first and fifth permanent magnets facing each other may face the straight portions 444a and 444c, and the second to fourth permanent magnets and the sixth to eighth permanent magnets may face the curved portions 444b and 444d.

<FIG> is a front view of a driving unit of a linear compressor according to Comparative Example <NUM>.

Referring to <FIG>, the permanent magnet <NUM> of the driving unit according to Comparative Example <NUM> may consist of <NUM> pieces. It may be understood that the upper right permanent magnet is referred to as a first permanent magnet, and the second to twelfth permanent magnets are sequentially arranged in a clockwise direction with respect to the first permanent magnet. In this case, a vertical line passing through the center of the inner stator <NUM> may pass through the space between the first permanent magnet and the twelfth permanent magnet and pass through the space between the sixth permanent magnet and the seventh permanent magnet.

Referring to <FIG>, the stator cores <NUM> of the driving unit according to Comparative Example <NUM> may be formed in eight pieces. It may be understood that two stator cores are added to the driving unit <NUM> according to the second embodiment of the present disclosure, and the plurality of stator cores are spaced apart from each other at equal intervals in the circumferential direction.

Referring to <FIG>, the stator cores <NUM> of the driving unit according to Comparative Example <NUM> may be formed in seven pieces. It may be understood that the stator core disposed on the upper portion is deleted in the driving unit according to Comparative Example <NUM>,.

<FIG> is a graph of torque according to a rotational position of a driving unit of second and third embodiments and Comparative Example <NUM> of the present disclosure.

Referring to <FIG>, when the permanent magnet <NUM> rotates counterclockwise, it represents the rotational torque generated in the permanent magnet <NUM>. A positive rotational torque means that a rotational torque that rotates the permanent magnet <NUM> in a counterclockwise direction is generated, and a negative rotational torque means that a rotational torque that rotates the permanent magnet <NUM> in a clockwise direction is generated.

That is, a vertical line passing through the center of the inner stator <NUM> passes through a space between the first permanent magnet and the twelfth permanent magnet, and in the case of Comparative Example <NUM> passing through the space between the sixth permanent magnet and the seventh permanent magnet, when the permanent magnet <NUM>, which is a mover, rotates, the permanent magnet <NUM> does not return to its original position, which may cause a problem.

In contrast, in the case of the driving unit <NUM> according to the second and third embodiments of the present disclosure, when the permanent magnet <NUM>, which is a mover, rotates, a force to restore the permanent magnet <NUM> to its original position is generated to enable stable operation of the linear compressor <NUM>. This also applies to the case of the driving unit <NUM> according to the first and fourth embodiments of the present disclosure.

<FIG> is a table of a lateral force according to an eccentric position of second and third Examples and Comparative Examples <NUM> and <NUM> of the present disclosure.

Referring to <FIG>, when only one stator core is removed as in Comparative Example <NUM>, it can be seen that a side force is greatly generated even when the eccentricity is <NUM>. That is, in the case of Comparative Example <NUM>, a problem may occur during operation of the linear compressor <NUM>.

In addition, when a pair of stator cores <NUM> are removed as in the driving unit <NUM> according to the second and third embodiments of the present disclosure, it can be seen that there is no significant difference in the side force due to eccentricity from Comparative Example <NUM> having eight stator cores <NUM>. That is, it can be seen that stable operation of the linear compressor <NUM> is possible even when the pair of stator cores <NUM> disposed at the upper and lower portions are removed. This also applies to the case of the driving unit <NUM> according to the first and fourth embodiments of the present disclosure. Through this, in the case of the driving unit <NUM> according to the first to fourth embodiments of the present disclosure, the manufacturing cost may be reduced by partially removing the configuration.

Claim 1:
A compressor driver comprising:
an inner stator (<NUM>);
a bobbin (<NUM>) surrounding the inner stator (<NUM>) in a circumferential direction;
a coil (<NUM>) wound around the bobbin (<NUM>);
a plurality of stator cores (448a, 448b, 448c, 448d, 448e, 448f) surrounding the bobbin (<NUM>) in the manner of covering at least a portion of respective front and rear surfaces of the bobbin (<NUM>), and spaced apart from each other in the circumferential direction; and
a plurality of permanent magnets (<NUM>) disposed between the inner stator (<NUM>) and the plurality of stator cores (448a, 448b, 448c, 448d, 448e, 448f), at least one curved portion (444b,444d) partially surrounding the inner stator (<NUM>);
characterized in that the bobbin (<NUM>) includes:
a pair of straight portions (444a, 444c) positioned opposite to each other with respect to the inner stator (<NUM>), and
in that the at least one curved portion (444b, 444d) partially surrounding the inner stator (<NUM>) is connecting the pair of straight portions (444a, 444c) to each other.