Patent Description:
"Laundry treating apparatus" is a general term for a washing machine for washing laundry (an object to be washed or an object to be dried), a dryer for drying laundry, and an apparatus capable of both washing and drying laundry.

The washing machine generally includes a tub, which stores water therein, a washing drum, which is provided in the tub to store laundry therein, and a driving unit (a washing driving unit), which rotates the washing drum. The dryer generally includes a drying drum, which stores laundry therein, a driving unit (a drying driving unit), which rotates the drying drum, and a heat exchange unit, which supplies air to the drying drum to remove moisture from laundry.

The washing driving unit generally includes a stator, which is secured to the tub to form a rotating magnetic field, a rotor, which is rotated by the rotating magnetic field, and a rotation shaft, which passes through the tub to connect the washing drum to the rotor. The drying driving unit generally includes a motor, a pulley, which is secured to the rotation shaft of the motor, and a belt (a power transmission unit), which transmits the rotational motion of the pulley to the drying drum.

The washing driving unit is configured such that the rotation shaft of the motor connects the washing drum to the rotor. In order to wash or spin-dry laundry, the washing driving unit needs to increase the rate of rotation of the washing drum or to change the rotation direction of the washing drum. When the rotation shaft of the motor directly connects the washing drum to the rotor, it is possible to easily control the rate of rotation and the rotation direction of the washing drum.

Meanwhile, the conventional drying driving unit is generally structured such that a power transmission unit, such as a belt, connects the drying drum to the rotation shaft of the motor. The reason why the dryer employs a power transmission unit, such as a belt, in order to rotate the drying drum is that the rate of rotation of the drying drum does not need to be maintained particularly high and that the rotation direction of the drying drum generally does not need to be changed. However, if the dryer is designed so as to be capable of changing the rate of rotation and the rotation direction of the drying drum, movement of laundry in the drying drum may be capable of being controlled, leading to a reduction in the drying time and improvement of drying performance.

There is disclosed a conventional dryer that includes a drying driving unit connecting a rotor to a drying drum using a speed reducer (<CIT>). The drying driving unit is structured such that an input shaft, connected to the rotor, and an output shaft, connected to the drying drum, are disposed coaxially. Accordingly, it may be possible to shorten the drying time or to improve drying performance. However, heat supplied to the drying drum is transferred to the inside of the drying driving unit, which may lead to deterioration in the durability of the drying driving unit.

<CIT> relates to a drive system for a compact rotary drum type drying apparatus.

An object of the present disclosure is to provide a laundry treating apparatus, which includes a power transmission unit configured to connect an input shaft, which is connected to a rotor, and an output shaft, which is connected to a drum, to each other such that the input shaft and the output shaft are disposed coaxially.

In addition, another object of the present disclosure is to provide a laundry treating apparatus, which is capable of minimizing the transfer of external heat to the inside of the power transmission unit, thereby minimizing deterioration in the durability of the power transmission unit.

In addition, another object of the present disclosure is to provide a laundry treating apparatus, which includes a means for dissipating heat in the power transmission unit to the outside, thereby minimizing deterioration in the durability of the power transmission unit.

In addition, another object of the present disclosure is to provide a laundry treating apparatus, which is capable of minimizing deterioration in the durability of bearings supporting the input shaft and the output shaft caused by external force acting on the input shaft and the output shaft during operation of the power transmission unit.

The present invention provides a laundry treating apparatus including a drum, which includes a drum body providing a space to store laundry therein, a front cover forming the front surface of the drum body, a rear cover forming the rear surface of the drum body, and a drum introduction opening formed through the front cover to communicate with the inside of the drum body, a drying unit configured to supply heated air to the drum body, a fixing panel disposed at a position spaced apart from the rear cover, a power transmission unit, which includes a housing secured to the fixing panel, an input shaft having one end located outside the housing and an opposite end located in the housing, an output shaft having one end secured to the rear cover and an opposite end located in the housing, and a gear unit located in the housing to transmit the rotational motion of the input shaft to the output shaft, a motor, which includes a stator secured to the fixing panel or the housing to form a rotating magnetic field and a rotor configured to be rotated by the rotating magnetic field and to allow the one end of the input shaft to be secured thereto, and a heat insulation part made of a material having heat conductivity lower than the heat conductivity of the housing to reduce the amount of heat that is transferred from the outside of the housing to the inside thereof, wherein the fixing panel is located between the rear cover and the housing, and the heat insulation part is located at a position between the housing and the fixing panel.

The heat insulation part may be located on the surface of the housing that faces the fixing panel.

The housing may be secured to the fixing panel so as to be located in a space isolated from the space in which the drum is located.

The heat insulation part may be made of a material having heat conductivity lower than the heat conductivity of the fixing panel.

The housing may include a housing body, which is formed in a hollow cylindrical shape and has an opening formed in the surface thereof that faces the fixing panel, and a housing cover, which is secured to the housing body to close the opening. The heat insulation part may be provided at the housing cover.

The housing body and the housing cover may be made of a metallic material, and the heat insulation part may be made of a non-metallic material.

The housing cover may include a cover body surrounding the opening, an output shaft through-hole formed through the cover body to allow the output shaft to be inserted thereinto, and an output shaft support portion protruding from the cover body toward the fixing panel and surrounding the output shaft through-hole. The heat insulation part may include a cover insulation body secured to the cover body and a support portion insulation body surrounding the circumferential surface of the output shaft support portion.

The housing cover may further include a bent portion formed such that the region of the cover body in which the output shaft through-hole is formed protrudes toward the fixing panel.

The housing cover and the cover insulation body may be formed integrally with each other.

The cover insulation body may include a first insulation body, which is formed on the surface of the cover body that faces the fixing panel in the space provided by the cover body, and a second insulation body, which is formed on the surface of the cover body that faces the housing body in the space provided by the cover body.

The laundry treating apparatus may further include a cover through-hole formed through the cover body and a connection body inserted into the cover through-hole to connect the first insulation body to the second insulation body.

The cover insulation body may be secured to the housing cover via insert injection molding.

The laundry treating apparatus may further include an output shaft bearing, which is provided inside the output shaft support portion to rotatably secure the output shaft to the inside of the output shaft support portion, and a seal, which is secured to the output shaft support portion to prevent the introduction of external air into the output shaft bearing.

The laundry treating apparatus may further include a mounting portion provided at the cover body to allow the stator to be detachably secured thereto.

The heat insulation part may further include a mounting portion insulation body surrounding the mounting portion.

The stator may include a ring-shaped core, a plurality of support bars protruding radially from the outer circumferential surface of the core, a ring-shaped core insulation part surrounding the core, a plurality of support bar insulation parts provided in the core insulation part to surround respective ones of the plurality of support bars, a coil provided in each of the plurality of support bar insulation parts, and a stator bracket provided on the inner circumferential surface of the core insulation part so as to be coupled to the mounting portion.

The laundry treating apparatus may further include a bracket protrusion formed at the stator bracket and a protrusion accommodation recess formed in the cover insulation body to allow the bracket protrusion to be inserted thereinto.

The housing body may include a housing base, an input shaft through-hole formed through the housing base to allow the input shaft to be inserted thereinto, and a housing circumferential surface extending from the edge of the housing base toward the fixing panel. The accommodation space may be formed by the housing base and the housing circumferential surface.

The ring gear, the driving gear, and the driven gear may be provided so as to be prevented from escaping the space provided by the accommodation space.

The housing body may further include a cover-fixing plate provided on the housing circumferential surface to allow the housing cover to be secured thereto.

The stator may include a ring-shaped core, a plurality of support bars protruding radially from the outer circumferential surface of the core, a ring-shaped core insulation part surrounding the core, a plurality of support bar insulation parts provided in the core insulation part to surround respective ones of the plurality of support bars, a coil provided in each of the plurality of support bar insulation parts, and a stator bracket provided on the inner circumferential surface of the core insulation part so as to be coupled to a mounting portion. The housing cover may further include the mounting portion to which the stator bracket is detachably secured. The cover-fixing plate may have a fixing plate through-hole formed therein to allow the mounting portion to pass therethrough.

The laundry treating apparatus may further include an input shaft support portion extending from the housing base toward the rotor and surrounding the input shaft through-hole and an input shaft bearing provided in the input shaft support portion to rotatably secure the input shaft to the input shaft support portion.

The input shaft bearing may include a first input shaft bearing and a second input shaft bearing, which are located in the input shaft support portion.

The laundry treating apparatus may further include an output shaft through-hole formed through the housing cover to allow the output shaft to be inserted thereinto, an output shaft support portion extending from the housing cover toward the fixing panel and surrounding the output shaft through-hole, an output shaft bearing for securing the output shaft to the output shaft support portion, and a seal provided at the output shaft support portion to prevent the introduction of external air into the output shaft bearing.

The output shaft bearing may include a first output shaft bearing and a second output shaft bearing, which are located in the output shaft support portion.

The housing may be located in a space isolated from the space in which the drum is located.

The laundry treating apparatus may further include a heat insulation part, which is made of a material having heat conductivity lower than the heat conductivity of the housing cover and is secured to the housing cover.

The present invention provides a laundry treating apparatus, which includes a power transmission unit configured to connect an input shaft, which is connected to a rotor, and an output shaft, which is connected to a drum, to each other such that the input shaft and the output shaft are disposed coaxially.

In addition, the present invention provides a laundry treating apparatus, which is capable of minimizing the transfer of external heat to the inside of the power transmission unit, thereby minimizing deterioration in the durability of the power transmission unit.

In addition, the present invention provides a laundry treating apparatus, which includes a means for dissipating heat in the power transmission unit to the outside, thereby minimizing deterioration in the durability of the power transmission unit.

In addition, the present invention provides a laundry treating apparatus, which is capable of minimizing deterioration in the durability of bearings supporting the input shaft and the output shaft caused by external force acting on the input shaft and the output shaft during operation of the power transmission unit.

Hereinafter, embodiments of a laundry treating apparatus will be described in detail with reference to the accompanying drawings.

<FIG> is a view showing an example of a laundry treating apparatus <NUM>. The laundry treating apparatus <NUM> may include a cabinet <NUM> and a drum <NUM>, which is rotatably provided inside the cabinet and provides a space for storing laundry (an object to be washed or an object to be dried). As shown in <FIG>, a drying unit <NUM> may be provided inside the cabinet <NUM> in order to remove moisture from laundry by supplying high-temperature dry air (air having a temperature higher than room temperature or air having dryness higher than the dryness of indoor air) to the drum <NUM>.

As shown in <FIG>, the cabinet <NUM> may include a front panel <NUM>, which forms the front surface of the laundry treating apparatus, and a base panel <NUM>, which forms the bottom surface of the laundry treating apparatus. The front panel <NUM> has formed therein an introduction opening <NUM>, which communicates with the drum <NUM>. The introduction opening <NUM> may be closed by a door <NUM>.

A control panel <NUM> may be provided on the front panel <NUM>. The control panel <NUM> may include an input unit for receiving a control command from a user and a display for outputting information, such as control commands selectable by the user. The input unit may include a power supply request unit for requesting the supply of power to the laundry treating apparatus, a course input unit for allowing the user to select a desired course from among a plurality of courses, and an execution request unit for requesting commencement of the course selected by the user.

The drum <NUM> may be formed in a hollow cylindrical shape. <FIG> is a view illustrating the case in which the drum <NUM> includes a drum body <NUM>, which has the shape of a cylinder that has an open front surface and an open rear surface, a front cover <NUM>, which forms the front surface of the drum body <NUM>, and a rear cover <NUM>, which forms the rear surface of the drum body <NUM>. The front cover <NUM> may have formed therein a drum introduction opening <NUM>, through which the inside of the drum body <NUM> communicates with the outside, and the rear cover <NUM> may have formed therein an air inlet <NUM>, through which external air flows into the drum body <NUM>.

As shown in <FIG>, the drum body <NUM> may further include a lifter <NUM>. The lifter <NUM> may be formed such that a board, which extends from the front cover <NUM> toward the rear cover <NUM>, protrudes from the drum body <NUM> toward the rotation center of the drum <NUM> (protrudes from the circumferential surface of the drum toward the rotation center of the drum).

In the laundry treating apparatus <NUM>, the drum <NUM> may have a drum through-hole, which is formed through the drum body <NUM> so that the inside of the drum communicates with the outside of the drum. However, when the laundry treating apparatus <NUM> is configured as a laundry drying apparatus, the drum <NUM> may not have a drum through-hole therein.

The drum <NUM> may be rotatably secured to at least one of a first body support part <NUM> or a second body support part <NUM>. The drawings illustrate the case in which the rear cover <NUM> is rotatably secured to the second body support part <NUM> via a motor <NUM> (a driving unit) and in which the front cover <NUM> is rotatably connected to the first body support part <NUM>.

The first body support part <NUM> may be formed as a support panel <NUM>, which is secured to the cabinet <NUM> and is located between the front panel <NUM> and the front cover <NUM>. The support panel <NUM> may be secured to the base panel <NUM>, and may be located between the front panel <NUM> and the front cover <NUM>. In this case, the rear surface of the front panel <NUM> (the surface facing the support panel) may be secured to the support panel <NUM>, and the lower end thereof may be secured to the base panel <NUM>.

The support panel <NUM> may include a support panel through-hole <NUM>, a drum connection body <NUM> (refer to <FIG>) connecting the support panel through-hole <NUM> to the drum introduction opening <NUM>, and a panel connection body <NUM> connecting the support panel through-hole <NUM> to the introduction opening <NUM>. The support panel through-hole <NUM> may be formed through the support panel <NUM> so that the introduction opening <NUM> communicates with the drum introduction opening <NUM>.

As shown in <FIG>, the drum connection body <NUM> may be formed as a pipe that is secured to the rear surface of the support panel <NUM> (the surface facing the drum introduction opening in the space provided by the support panel). One end of the drum connection body <NUM> may be formed so as to surround the support panel through-hole <NUM>, and the free end of the drum connection body <NUM> may be formed so as to support the front cover <NUM>. That is, the free end of the drum connection body <NUM> may be inserted into the drum introduction opening <NUM>, or may be in contact with the free end of the front cover <NUM>, which forms the drum introduction opening <NUM>.

<FIG> illustrates the case in which the free end of the drum connection body <NUM> is in contact with the free end of the front cover <NUM>. In this case, the drum connection body <NUM> may be provided with a ring-shaped connection damper <NUM>. The connection damper <NUM> serves to minimize the risk of separation of the drum introduction opening <NUM> from the drum connection body <NUM> (the risk of leakage of air in the drum to the cabinet) when the drum <NUM> rotates or vibrates.

The panel connection body <NUM> may be formed as a pipe that is secured to the front surface of the support panel <NUM> (the surface facing the front panel in the space provided by the support panel). One end of the panel connection body <NUM> may be formed so as to surround the support panel through-hole <NUM>, and the other end of the panel connection body <NUM> may be formed so as to be connected to the introduction opening <NUM>. Therefore, the laundry supplied to the introduction opening <NUM> may move to the drum body <NUM> through the panel connection body <NUM>, the support panel through-hole <NUM>, the drum connection body <NUM>, and the drum introduction opening <NUM>.

The support panel <NUM> may have an exhaust port <NUM>, which is formed through the panel connection body <NUM>, and a filter <NUM> may be detachably secured to the exhaust port <NUM>. The filter <NUM> may be formed in any of various structures, so long as the same is capable of removing foreign substances from the air moving from the drum <NUM> to the exhaust port <NUM>.

The support panel <NUM> may be further provided with drum support parts <NUM> and <NUM> for preventing the drum <NUM> from sagging. The drum support parts may include a first roller <NUM> and a second roller <NUM>, which are secured to the support panel <NUM> and rotatably support the drum <NUM>. Although it is illustrated in <FIG> that the first roller <NUM> and the second roller <NUM> support the drum body <NUM>, the rollers <NUM> and <NUM> may support the front cover <NUM>.

The second body support part <NUM> may be formed as a fixing panel <NUM>, which is secured to the cabinet <NUM> so as to be located at a point spaced apart from the rear cover <NUM>. <FIG> illustrates the case in which the fixing panel <NUM> is secured to the base panel <NUM> to form the rear surface of the laundry treating apparatus <NUM> (the rear surface of the cabinet).

The fixing panel <NUM> may have formed therein a driving-unit-mounting recess <NUM>, which provides a space in which the motor <NUM> is mounted. The driving-unit-mounting recess <NUM> may be formed such that a portion of the fixing panel <NUM> is concavely depressed toward the rear cover <NUM> of the drum. The fixing panel <NUM> may have a fixing panel through-hole <NUM> formed therein to allow a shaft (an output shaft) for rotating the drum <NUM> to pass therethrough. The fixing panel through-hole <NUM> may be located within the driving-unit-mounting recess <NUM>.

As described above, when the drum <NUM> includes the drum body <NUM>, the front cover <NUM> secured to the drum body, and the rear cover <NUM> secured to the drum body, the rigidity of the drum is higher than that of a structure in which the open front surface and the open rear surface of the drum body <NUM> are rotatably connected to the support panel <NUM> and the fixing panel <NUM>, respectively. The increase in the rigidity of the drum may minimize deformation of the drum body <NUM> during rotation of the drum, thus minimizing a problem in which laundry catches in the space between the drum body and the support panel or in the space between the drum body and the fixing panel due to deformation of the drum body <NUM> (thereby minimizing the load on the motor).

As shown in <FIG>, the drying unit <NUM> may include an exhaust passage <NUM>, which is connected to the exhaust port <NUM>, a supply passage <NUM>, which guides the air in the exhaust passage <NUM> to the drum body <NUM>, and a heat exchange unit <NUM>, which is provided inside the exhaust passage <NUM> to sequentially dehumidify and heat air.

The exhaust passage <NUM> may include a first duct <NUM>, which is connected to the exhaust port <NUM>, a second duct <NUM>, which is connected to the supply passage <NUM>, and a third duct <NUM>, which connects the first duct <NUM> to the second duct <NUM>. The third duct <NUM> may be secured to the base panel <NUM>.

The heat exchange unit <NUM> may be implemented as any of various devices, so long as the same is capable of sequentially dehumidifying and heating the air introduced into the exhaust passage <NUM>. <FIG> illustrates the case in which the heat exchange unit <NUM> is implemented as a heat pump. That is, the heat exchange unit <NUM> includes a first heat exchanger <NUM> (a heat-absorbing part), which removes moisture from the air introduced into the exhaust passage <NUM>, a second heat exchanger <NUM> (a heat-generating part), which is provided inside the exhaust passage <NUM> to heat the air that has passed through the heat-absorbing part <NUM>, and a fan <NUM>, which causes the air discharged from the drum <NUM> to sequentially pass through the heat-absorbing part and the heat-generating part and then to move to the supply duct <NUM>.

The heat-absorbing part <NUM> and the heat-generating part <NUM> are sequentially disposed in the direction in which air flows, and are connected to each other via a refrigerant pipe <NUM>, which forms a circulation path of the refrigerant. The refrigerant is moved along the refrigerant pipe <NUM> by a compressor <NUM>, which is located outside the exhaust passage <NUM>, and the refrigerant pipe <NUM> is provided with a pressure regulator <NUM> for controlling the pressure of the refrigerant.

As shown in <FIG>, the air inlet <NUM>, which is provided in the rear cover <NUM> of the drum, may be composed of a plurality of holes, which are disposed around the center of the rear cover <NUM> (the rotation center of the drum). In this case, the supply passage <NUM> may include a supply duct <NUM>, which is provided in the fixing panel <NUM> to form a passage along which the air discharged from the second duct <NUM> moves, and a first passage-forming part <NUM> and a second passage-forming part <NUM>, which guide the air in the supply duct <NUM> to the air inlet <NUM>.

The supply duct <NUM> may be formed such that a portion of the fixing panel <NUM> is bent in a direction away from the rear cover <NUM> to form a passage (an air movement passage). In addition, the supply duct <NUM> may be formed in the shape of a ring that surrounds the driving-unit-mounting recess <NUM>, and the second duct <NUM> may be formed so as to be connected to the circumferential surface of the supply duct <NUM>.

The first passage-forming part <NUM> may be provided so as to surround the outer circumferential surface of the ring formed by the holes of the air inlet <NUM>, and the second passage-forming part <NUM> may be provided so as to surround the inner circumferential surface of the ring formed by the holes of the air inlet <NUM>.

The first passage-forming part <NUM> and the second passage-forming part <NUM> may be secured to the rear cover <NUM>, or may be secured to the supply duct <NUM>. <FIG> illustrates the case in which the passage-forming parts <NUM> and <NUM> are secured to the rear cover <NUM>. In the case illustrated in <FIG>, the free end of the first passage-forming part <NUM> surrounds the outer circumferential surface of the passage (the ring-shaped passage) formed by the supply duct <NUM>, and the free end of the second passage-forming part <NUM> surrounds the inner circumferential surface of the passage formed by the supply duct <NUM>. The first passage-forming part <NUM> and the second passage-forming part <NUM> may be made of rubber, felt, or the like.

The motor <NUM> for rotating the drum <NUM> includes a stator <NUM>, which is located in the driving-unit-mounting recess <NUM> to form a rotating magnetic field, and a rotor <NUM>, which is rotated by the rotating magnetic field. The rotational motion of the rotor <NUM> is transmitted to the drum <NUM> via a power transmission unit <NUM>, which is secured to the fixing panel <NUM>, and the stator <NUM> is secured to at least one of the fixing panel <NUM> or the power transmission unit <NUM>. The structure in which the stator <NUM> is secured to the power transmission unit <NUM> is advantageous from the aspect of maintenance of coaxiality between an input shaft <NUM> and an output shaft <NUM>, which are included in the power transmission unit <NUM> (consequently minimizing vibration of the laundry treating apparatus during rotation of the drum and minimizing deterioration in the durability of the power transmission unit).

In order to prevent the motor <NUM>, which is provided in the driving-unit-mounting recess <NUM>, from being exposed to the outside (in order to improve the durability of the motor and to prevent accidents by preventing the motor from being exposed to the external environment), the fixing panel <NUM> may be further provided with a cover panel <NUM> for preventing the motor <NUM> from being exposed to the outside. Further, the cover panel <NUM> may be formed in a shape that is also capable of preventing the supply duct <NUM> from being exposed to the outside (a shape surrounding the supply duct). The reason for this is not only to minimize radiation of heat to the outside of the supply duct <NUM>, but also to prevent an accident, which may be caused by contact of the user's body with the supply duct <NUM>.

As shown in <FIG>, the stator <NUM> may include a core <NUM> (a ring-shaped core), which has a through-hole 511b (a core through-hole) formed in the center thereof, a plurality of support bars 511a, which protrude radially from the outer circumferential surface of the core <NUM>, a core insulation part <NUM>, which insulates the core and has a ring shape, a plurality of support bar insulation parts <NUM>, which are provided in the core insulation part <NUM> to surround the support bars, and coils (not shown), which are provided in the support bar insulation parts <NUM>.

The core insulation part <NUM> is formed in the shape of a ring that has an insulation part through-hole <NUM> formed in the center thereof to form a space in which the core <NUM> is accommodated. For ease of assembly, the core insulation part <NUM> may include a first insulation body 512a and a second insulation body 512b. In this case, the support bar insulation parts <NUM> may include first support bar insulation parts, which are provided in the first insulation body 512a, and second support bar insulation parts, which are provided in the second insulation body 512b.

The core insulation part <NUM> may be provided with a stator bracket <NUM>. The stator bracket <NUM> may include a plurality of brackets, which protrude from the inner circumferential surface of the core insulation part <NUM> toward the center of the insulation part through-hole <NUM>. When the core insulation part <NUM> includes the first insulation body 512a and the second insulation body 512b, the stator bracket <NUM> may include first brackets 515a, which are provided in the first insulation body, and second brackets 515b, which are provided in the second insulation body and are coupled to the first brackets 515a.

The stator bracket <NUM> may be secured to the power transmission unit <NUM> using a stator coupling part such as a bolt. To this end, the stator bracket <NUM> may have a coupling part through-hole <NUM> formed therein.

As shown in <FIG>, the rotor <NUM> may include a rotor body <NUM>, a rotor circumferential surface <NUM>, which extends from the edge of the rotor body <NUM> toward the fixing panel <NUM> to form a space in which the stator <NUM> is accommodated, and a plurality of permanent magnets <NUM>, which are secured to the rotor circumferential surface <NUM> such that N-poles and S-poles thereof are alternately exposed.

The motor <NUM> may further include a motor heat dissipation part <NUM>, which dissipates the heat generated from the stator <NUM> to the outside of the rotor <NUM>. The motor heat dissipation part <NUM> may include a plurality of rotor through-holes <NUM>, which are formed through the rotor body <NUM>, and a plurality of rotor blades <NUM>, which are provided at the rotor body <NUM> to form airflow for inducing the air in the rotor to move to the rotor through-holes <NUM>.

Each rotor through-hole <NUM> may be formed as a slit that extends from the center of the rotor body <NUM> toward the rotor circumferential surface <NUM>, and each rotor blade <NUM> may be formed as a plate that protrudes from the rotor body <NUM> toward the fixing panel <NUM>. In this case, it is desirable for each rotor blade <NUM> to extend from the center of the rotor body <NUM> toward the rotor circumferential surface <NUM>. The rotor through-holes <NUM>, each of which is formed as a slit, may be radially disposed about the center of the rotor body <NUM> (the input shaft), and each of the rotor blades <NUM> may be fixed to the edge of a respective one of the rotor through-holes <NUM>.

<FIG> is a view showing an example of the power transmission unit <NUM>. The power transmission unit <NUM> includes a housing H, which is secured to the fixing panel <NUM>, an input shaft <NUM>, which is rotatably secured to the bottom surface of the housing H (the surface oriented in a direction toward the rotor), an output shaft <NUM>, which is rotatably secured to the upper surface of the housing H (the surface oriented in a direction toward the fixing panel), and a gear unit, which is provided inside the housing to transmit the rotational motion of the input shaft <NUM> to the output shaft <NUM>. The input shaft <NUM> may be formed as a shaft that has one end secured to the rotor <NUM> and an opposite end located inside the housing H, and the output shaft <NUM> may be formed as a shaft that has one end secured to the rear cover <NUM> and an opposite end located inside the housing H.

It is desirable for the housing H to be secured to the fixing panel <NUM> and to be disposed in the space (the external space of the cabinet) isolated from the space in which the drum <NUM> is located (the internal space in the cabinet). The reason for this is to minimize the transfer of heat in the cabinet (heat radiated from the drum or the drying unit) to the inside of the housing H to thus improve the durability of the power transmission unit <NUM>.

The input shaft <NUM> may be coupled to the rotor body <NUM> using the shaft coupling part <NUM> shown in <FIG>. The shaft coupling part <NUM> may include a disc-shaped coupling body <NUM> and a shaft coupling hole <NUM>, which is formed through the coupling body to allow one end of the input shaft <NUM> to be coupled thereto.

In order to facilitate assembly of the coupling body <NUM> and the rotor body <NUM>, the coupling body <NUM> may be provided with a body protrusion <NUM>, and the rotor body <NUM> may have a body protrusion through-hole <NUM> formed therein to allow the body protrusion <NUM> to be inserted thereinto.

Furthermore, in order to increase the strength of the coupling body <NUM>, the coupling body <NUM> may be further provided with a coupling body bent portion <NUM>. The coupling body bent portion <NUM> may be formed such that the surface of the coupling body <NUM> that faces the housing H is concavely bent toward the rotor body <NUM>. In this case, the rotor body <NUM> may have a bent portion through-hole <NUM> formed therein to allow the coupling body bent portion <NUM> to pass therethrough.

The output shaft <NUM> may be inserted into the fixing panel through-hole <NUM> to be connected to the drum <NUM>, and the rear cover <NUM> may be provided with a shaft bracket <NUM> (refer to <FIG>), to which the output shaft <NUM> is secured. The reason for this is to disperse the stress applied to the center of the rear cover <NUM> during rotation of the output shaft <NUM>.

In order to prevent sagging of the housing H and to minimize deformation of the driving-unit-mounting recess <NUM>, the housing H may be secured to the fixing panel <NUM> using a transmission unit bracket <NUM> and a housing coupling part <NUM>.

As shown in <FIG>, the transmission unit bracket <NUM> may have a bracket through-hole <NUM> to allow the output shaft <NUM> to pass therethrough, and the housing coupling part <NUM> may be formed as a bolt that connects the housing H to the transmission unit bracket <NUM>. The transmission unit bracket <NUM> may be made of the same material as the fixing panel <NUM>, or may be made of a material having strength higher than the strength of the fixing panel <NUM>.

<FIG> illustrates the case in which the transmission unit bracket <NUM> is secured to the surface of the fixing panel <NUM> that faces the rear cover <NUM>. However, the transmission unit bracket <NUM> may be secured to the surface facing the cover panel <NUM> in the space provided by the fixing panel <NUM>.

As shown in <FIG>, the housing H may include a housing body <NUM>, which is formed in a hollow cylindrical shape and has an opening formed in the surface thereof that faces the fixing panel <NUM>, and a housing cover <NUM>, which is secured to the housing body <NUM> to close the opening.

The housing body <NUM> may include an accommodation space <NUM> in which the gear unit G is mounted. The accommodation space <NUM> may communicate with the outside through the opening. The accommodation space <NUM> may be defined by a housing base 621a, to which the input shaft <NUM> is secured, and a housing circumferential surface 621b, which extends from the edge of the housing base 621a toward the housing cover <NUM>.

As shown in <FIG>, the housing body <NUM> may be provided with an input shaft support portion <NUM>, which extends from the housing base 621a toward the rotor <NUM>. The input shaft support portion <NUM> may be formed as a pipe that surrounds an input shaft through-hole <NUM> formed through the housing body <NUM>. That is, the input shaft through-hole <NUM> may be formed through the input shaft support portion <NUM> so as to communicate with the accommodation space <NUM>.

The input shaft <NUM> inserted into the input shaft through-hole <NUM> is rotatably secured to the input shaft support portion <NUM> using input shaft bearings <NUM> and <NUM>. The input shaft bearings may include a first input shaft bearing <NUM> and a second input shaft bearing <NUM>, which is fixed in the input shaft through-hole <NUM> so as to be located between the first input shaft bearing <NUM> and the rotor <NUM>.

The free end of the input shaft support portion <NUM> may be inserted into the coupling body bent portion <NUM>, which is provided at the shaft coupling part <NUM>. The length of the input shaft support portion <NUM> may need to be increased in order to fix the two input shaft bearings <NUM> and <NUM>. However, since the free end of the input shaft support portion <NUM> is inserted into the coupling body bent portion <NUM>, it is possible to minimize the amount of space that is required for installation of the motor <NUM> and the power transmission unit <NUM> (thereby minimizing the volume of the laundry treating apparatus).

The housing cover <NUM> may be formed in any of various shapes, so long as the same is capable of opening or closing the opening formed in the housing body <NUM>. <FIG> illustrates the case in which the housing cover <NUM> is implemented as a disc-shaped cover body <NUM>. The housing cover <NUM> may be secured to the housing body <NUM> using a cover-fixing plate <NUM>, which is provided on the housing circumferential surface 621b.

The housing cover <NUM> may include an output shaft support portion <NUM>, which extends from the cover body <NUM> toward the fixing panel <NUM>, an output shaft through-hole <NUM>, which is formed through the output shaft support portion <NUM> to allow the output shaft <NUM> to be inserted thereinto, and output shaft bearings <NUM> and <NUM>, which are provided in the output shaft support portion <NUM> to rotatably secure the output shaft <NUM> to the output shaft through-hole <NUM>.

The housing cover <NUM> includes a mounting portion <NUM>, which is provided at the cover body <NUM> and to which the stator <NUM> is secured. The mounting portion <NUM> may be formed in any of various shapes that allow the stator coupling part (the bolt or the like) to be coupled thereto. The drawings illustrate the case in which the mounting portion <NUM> is formed in a hollow cylindrical shape.

The mounting portion <NUM> may be provided in a plural number, and the plurality of mounting portions <NUM> may be disposed on the circumferential surface of the cover body <NUM>. It is desirable for the stator bracket <NUM> to be provided in the same number as the number of mounting portions <NUM>.

When the mounting portions <NUM> are formed in the shape of a cylinder that protrudes from the cover body <NUM> toward the rotor <NUM>, it is desirable for the cover-fixing plate <NUM> to have fixing plate through-holes <NUM> formed therein to allow the mounting portions <NUM> to be inserted thereinto. The reason for this is to minimize the outer diameter of the cover-fixing plate <NUM> (thereby minimizing the amount of space that is required for installation of the housing).

In order to increase the strength of the housing cover <NUM>, the cover body <NUM> may be provided with a bent portion <NUM>, which is formed such that a region including the output shaft through-hole <NUM> protrudes toward the fixing panel <NUM>.

The output shaft bearings may include a first output shaft bearing <NUM> and a second output shaft bearing <NUM>, which are secured to the output shaft support portion <NUM> and are located in the output shaft through-hole <NUM>. In addition, in order to prevent external air from being supplied to the output shaft bearings <NUM> and <NUM>, the housing cover <NUM> may further include a seal <NUM>, which is secured to the output shaft support portion <NUM> to close the output shaft through-hole <NUM>.

The housing H is secured to the fixing panel <NUM> via the housing coupling part <NUM>. The stator <NUM> is secured to the housing H by securing the stator coupling part, which is inserted into the coupling part through-hole <NUM>, to the mounting portion <NUM>. The rotor <NUM> is secured to the housing H using the input shaft <NUM>. That is, since the stator <NUM> and the rotor <NUM> are secured to the housing H (since the stator and the rotor vibrate together with the housing), it is possible to minimize deterioration in coaxiality between the input shaft <NUM> and the output shaft <NUM>.

The gear unit G may include a ring gear <NUM>, which is secured to the housing circumferential surface 621b and is located in the accommodation space <NUM>, a driving gear <NUM>, which is secured to the input shaft <NUM> and is located in the accommodation space <NUM>, a cage <NUM>, which is located in the accommodation space <NUM> and to which the opposite end of the output shaft <NUM> is secured, and a driven gear <NUM>, which is rotatably secured to the case <NUM> to connect the driving gear <NUM> to the ring gear <NUM>.

As shown in <FIG>, the ring gear <NUM> may include a gear body <NUM>, which is secured to the housing circumferential surface 621b, and gear teeth <NUM>, which are formed on the inner circumferential surface of the gear body.

The cage <NUM> may include a first base <NUM>, which is located in a gear body through-hole <NUM> (a through-hole defined by the gear teeth) formed through the gear body and to which one end of the output shaft <NUM> is secured, a second base <NUM>, which is located in the gear body through-hole <NUM> and has a base through-hole <NUM> formed in the center thereof, and a connection shaft <NUM>, which connects the first base to the second base and serves as a rotation shaft of the driven gear <NUM>. Since the output shaft <NUM> is secured to the first base <NUM>, whether the output shaft <NUM> rotates is determined depending on whether the cage <NUM> rotates.

The driven gear <NUM> may be composed of a plurality of gears. The drawings illustrate the case in which the driven gear is composed of a first driven gear <NUM>, a second driven gear <NUM>, and a third driven gear <NUM>. The input shaft <NUM> is inserted into the base through-hole <NUM>, and is disposed coaxially with the output shaft <NUM>. The gear teeth of the driving gear <NUM> are located in the space formed between the driven gears <NUM>, <NUM>, and <NUM> so as to be engaged with the gear teeth of the driven gears <NUM>, <NUM>, and <NUM>.

As shown in <FIG>, in order to facilitate coupling or assembly of the ring gear <NUM> and the housing body <NUM>, the gear body <NUM> may have a coupling protrusion accommodation recess <NUM> formed therein, and the housing base 621a may be provided with a ring gear coupling protrusion 621c, which is inserted into the coupling protrusion accommodation recess <NUM>.

In order to increase the durability of the gear unit G, the housing H may further include a heat insulation part <NUM>. The heat insulation part <NUM> serves to minimize the transfer of external heat to the accommodation space <NUM> in the housing, and is preferably made of a material having heat conductivity lower than the heat conductivity of the housing H. That is, when the housing body <NUM> and the housing cover <NUM> are made of a metallic material, it is desirable for the heat insulation part <NUM> to be made of a non-metallic material such as plastic.

When the housing H is secured to the fixing panel <NUM> and is located in the external space of the cabinet, it is desirable for the heat insulation part <NUM> to be made of a material having heat conductivity lower than the heat conductivity of the fixing panel <NUM>.

The heat insulation part <NUM> may be provided so as to surround the entire area of the housing H, or may be provided only in the region of the housing H that faces the fixing panel <NUM>. <FIG> illustrates the case in which the heat insulation part <NUM> is provided only on the housing cover <NUM> (the region facing the fixing panel).

As shown in <FIG>, the heat insulation part <NUM> may be formed integrally with the housing cover <NUM>. In one example, the heat insulation part <NUM> and the housing cover <NUM> may be formed through insert injection molding in which a melted material (plastic or the like) is injected into a mold in which the housing cover <NUM> is accommodated.

The heat insulation part <NUM> may include a cover insulation body <NUM>, which is secured to the cover body <NUM>, and a support portion insulation body <NUM>, which surrounds the circumferential surface of the output shaft support portion <NUM>. As shown in <FIG>, the cover insulation body <NUM> may include at least one of a first insulation body <NUM>, which is formed on the surface of the cover body <NUM> that faces the fixing panel <NUM> in the space provided by the cover body <NUM>, or a second insulation body <NUM>, which is formed on the surface of the cover body <NUM> that faces the housing body <NUM> in the space provided by the cover body <NUM>.

When the cover insulation body <NUM> includes both the first insulation body <NUM> and the second insulation body <NUM>, it is desirable for the cover insulation body <NUM> to further include a connection body <NUM>, which passes through the cover body <NUM> to connect the first insulation body <NUM> to the second insulation body <NUM>. In this case, the cover body <NUM> needs to have a cover through-hole <NUM> (refer to <FIG>) formed therein to allow the connection body <NUM> to be located therein.

As shown in <FIG>, the heat insulation part <NUM> may further include a mounting portion insulation body <NUM>, which surrounds the mounting portion <NUM>. The reason for this is to minimize the transfer of heat from the motor <NUM> to the cover body <NUM> through the mounting portion <NUM>. It is desirable for the mounting portion insulation body <NUM> to surround the entire area of the circumferential surface of the mounting portion <NUM>.

In order to facilitate coupling of the stator <NUM> and the mounting portion <NUM>, the laundry treating apparatus may further include a stator position setting unit <NUM>. The stator position setting unit <NUM> may include a bracket protrusion <NUM> (refer to <FIG>), which is formed at the stator bracket <NUM>, and a protrusion accommodation recess <NUM> (refer to <FIG>), which is formed in the second insulation body <NUM> to allow the bracket protrusion <NUM> to be inserted thereinto.

Unlike the above description, the heat insulation part may be secured to the fixing panel <NUM> so as to be located between the housing cover <NUM> and the fixing panel <NUM>, or may be secured to the fixing panel <NUM> so as to be located between the fixing panel <NUM> and the rear cover <NUM>. In this case, the heat insulation part may surround the fixing panel through-hole <NUM>, and may be formed as a plate having a diameter larger than the diameter of the cover body.

In the power transmission unit <NUM> having the above-described structure, the gear unit G is located in the accommodation space <NUM> formed by the housing body <NUM>. That is, the ring gear <NUM>, the driving gear <NUM>, and the driven gear <NUM> are provided so as to be prevented from escaping the accommodation space <NUM>. The reason why the accommodation space <NUM> is formed only in the housing body <NUM> is to install the gear unit G as far as possible from the fixing panel <NUM> (the heat transmission medium radiating the heat in the cabinet to the outside of the cabinet). Accordingly, the laundry treating apparatus <NUM> is capable of minimizing deterioration in the durability of the gear unit G.

Meanwhile, in the power transmission unit <NUM> having the above-described structure, when the driving gear <NUM> and the driven gear <NUM> rotate, repulsive force acting between the gears is transmitted to the input shaft <NUM> and the output shaft <NUM>. That is, when the driving gear and the driven gear rotate, external force acting in a direction away from the housing H or in a direction toward the inside of the housing H is input to the input shaft <NUM> and the output shaft <NUM>. The above-described operation is more effectively realized when the driving gear, the driven gear, and the ring gear are implemented as helical gears.

As shown in <FIG>, the laundry treating apparatus <NUM> may include a damper <NUM> in order to minimize the risk of separation of the input shaft <NUM> from the input shaft bearings <NUM> and <NUM> or the input shaft support portion <NUM> due to external force acting on the input shaft <NUM>.

The damper <NUM> is provided in the input shaft through-hole <NUM> so as to be located between the first input shaft bearing <NUM> and the second input shaft bearing <NUM>, and serves to reduce the transmission of vibration of the first input shaft bearing <NUM> to the second input shaft bearing <NUM>.

The damper <NUM> may be implemented as an elastic body (rubber or the like) that is secured to the circumferential surface of the input shaft <NUM> and is located between the first input shaft bearing <NUM> and the second input shaft bearing <NUM>. As shown in <FIG>, the damper <NUM> may include a damping body <NUM>, which has a diameter larger than the diameter of the input shaft <NUM> and smaller than the diameter of the input shaft through-hole <NUM> (a damping body, which has a diameter smaller than the outer diameter of the input shaft bearing), and a damping body through-hole <NUM>, which is formed through the damping body <NUM> and into which the input shaft <NUM> is inserted.

As shown in <FIG>, in order to minimize vibration of the housing H, it is desirable that one surface of the damping body <NUM> be in contact with the first input shaft bearing <NUM> and that the other surface of the damping body <NUM> be in contact with the second input shaft bearing <NUM>.

Furthermore, the input shaft support portion <NUM> may be further provided with a stopper <NUM> (a first stopper), which protrudes toward the center of the input shaft through-hole <NUM> and is located between the first input shaft bearing <NUM> and the second input shaft bearing <NUM>. The first stopper <NUM> serves to restrict the range within which the first input shaft bearing <NUM> moves toward the second input shaft bearing <NUM>, or serves to restrict the range within which the second input shaft bearing <NUM> moves toward the first input shaft bearing <NUM>.

Since the damping body <NUM> is coupled to the circumferential surface of the input shaft <NUM> (since the damping body is provided so as to rotate together with the input shaft), it is desirable to set the radius of the damping body <NUM> (the outer radius of the damper) to be shorter than the distance from the center of the input shaft through-hole <NUM> to the first stopper <NUM>.

In order to minimize the problem of separation of the output shaft bearings <NUM> and <NUM> from the housing H due to external force acting on the output shaft <NUM>, the output shaft support portion <NUM> may be provided with a stopper 635c (a second stopper), which restricts the movement range of the first output shaft bearing <NUM> and the movement range of the second output shaft bearing <NUM>. As shown in <FIG>, the output shaft support portion <NUM> may include a first mounting portion 635a, in which the first output shaft bearing <NUM> is located, and a second mounting portion 635b, in which the second output shaft bearing <NUM> is located. The second stopper 635c may be formed as a protrusion that is located between the first mounting portion 635a and the second mounting portion 635b.

In order to minimize the transfer of heat to the inside of the housing H and to dissipate heat from the housing H to the outside, the laundry treating apparatus may further include a heat dissipation part <NUM>. As shown in <FIG>, the heat dissipation part <NUM> may include at least one of a first heat dissipation part <NUM>, which is provided at the coupling body <NUM> to discharge air present between the housing body <NUM> and the rotor <NUM> to the outside of the rotor <NUM>, or a second heat dissipation part <NUM>, which is provided on the circumferential surface 621b of the housing body to dissipate the heat in the accommodation space <NUM> to the outside of the accommodation space <NUM>.

The first heat dissipation part <NUM> may be formed as a blade that protrudes from the coupling body <NUM> toward the housing base 621a. When the rotor <NUM> rotates, the coupling body <NUM> and the first heat dissipation part <NUM> rotate, so air present between the rotor <NUM> and the housing body <NUM> is discharged to the outside of the rotor <NUM> through the rotor through-hole <NUM>, with the result that the temperature of the housing H drops.

<FIG> illustrates the case in which the first heat dissipation part <NUM> is formed as a plurality of blades and the blades are radially disposed about the shaft coupling hole <NUM>. However, only a single blade may be provided at the coupling body <NUM>.

Meanwhile, when the coupling body <NUM> is provided with the coupling body bent portion <NUM>, it is desirable for the first heat dissipation part <NUM> to be formed as a blade extending from the coupling body bent portion <NUM> to the edge of the coupling body <NUM>. This enables the height of the blade (the length of the blade in a direction from the coupling body toward the housing body) to be increased, thereby achieving an effect of increasing the amount of air that is discharged.

The second heat dissipation part <NUM> may be formed as at least one of a housing protruding portion (a cooling fin or the like) that protrudes from the housing circumferential surface 621b or a housing bent portion (a bent recess or the like) that is bent from the housing circumferential surface 621b toward the accommodation space <NUM>. The second heat dissipation part <NUM> serves to increase the surface area of the housing circumferential surface 621b, thereby facilitating heat exchange between the housing body <NUM> and external air.

Hereinafter, the operation process of the above-described power transmission unit <NUM> will be described with reference to <FIG>.

<FIG> shows the inside of the housing body <NUM>. When the rotor <NUM> rotates, the input shaft <NUM> rotates. When the driving gear <NUM> is rotated by the input shaft <NUM>, the driven gears <NUM>, <NUM>, and <NUM>, which are engaged with the driving gear <NUM>, are also rotated. Since the driven gears <NUM>, <NUM>, and <NUM> are engaged with the ring gear <NUM>, which is secured to the housing body <NUM>, when the driven gears <NUM> rotate, the cage <NUM> and the output shaft <NUM> rotate, and the drum <NUM>, which is secured to the output shaft <NUM>, also rotates.

A portion of the heat supplied to the drum <NUM> by the drying unit <NUM> may be radiated to the outside of the drum <NUM> (the inside of the cabinet), and the heat in the cabinet may be radiated to the outside of the cabinet. If the heat radiated from the cabinet <NUM> is transferred to the inside of the housing H of the power transmission unit <NUM>, the durability of the gear unit G may be deteriorated. However, in the laundry treating apparatus <NUM>, the heat insulation part <NUM> is capable of minimizing the transfer of heat to the inside of the housing H, thus reducing the risk of deterioration in the durability of the gear unit G.

Claim 1:
A laundry treating apparatus comprising:
a drum (<NUM>) comprising a drum body (<NUM>) providing a space to store laundry therein, a front cover (<NUM>) forming a front surface of the drum body (<NUM>), a rear cover (<NUM>) forming a rear surface of the drum body (<NUM>), and a drum introduction opening (<NUM>) formed through the front cover (<NUM>) to communicate with an inside of the drum body (<NUM>);
a drying unit (<NUM>) configured to supply heated air to the drum body (<NUM>);
a fixing panel (<NUM>) disposed at a position spaced apart from the rear cover (<NUM>);
a power transmission unit (<NUM>) comprising a housing (H) secured to the fixing panel (<NUM>), an input shaft (<NUM>) having one end located outside the housing (H) and an opposite end located in the housing (H), an output shaft (<NUM>) having one end secured to the rear cover (<NUM>) and an opposite end located in the housing (H), and a gear unit (G) located in the housing (H) to transmit rotational motion of the input shaft (<NUM>) to the output shaft (<NUM>);
a motor (<NUM>) comprising a stator (<NUM>) secured to the fixing panel (<NUM>) or the housing (H) to form a rotating magnetic field and a rotor (<NUM>) configured to be rotated by the rotating magnetic field and to allow the one end of the input shaft (<NUM>) to be secured thereto; and
a heat insulation part (<NUM>) made of a material having heat conductivity lower than heat conductivity of the housing (H) to reduce an amount of heat that is transferred from an outside of the housing (H) to an inside of the housing (H),
wherein the fixing panel (<NUM>) is located between the rear cover (<NUM>) and the housing (H), and the heat insulation part (<NUM>) is located at a position between the housing (H) and the fixing panel (<NUM>).