Laundry treatment apparatus and method for assembling the same

A laundry treatment apparatus includes a cabinet, a tub, a drum, a balancer, and a coupling part. The tub defines a tub opening, and the drum includes a body rotatably disposed in the tub and defines a drum opening configured to communicate with the tub opening. The balancer includes a housing having in a ring shape and defining a circulation passage configured to circulate fluid circulate along a circumference of the housing and a housing through-hole configured to communicate with the drum and tub openings. The balancer further includes a fastening part arranged along a circumferential surface of the housing and coupled to the body. The coupling part is disposed at an upper end of the body, coupled to the fastening part along an outer circumferential surface of the fastening part, and curved or bent toward a central of the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2018-0116414, filed on Sep. 28, 2018, the disclosure of which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a laundry treatment apparatus and a method for assembling the same, and more particularly to a laundry treatment apparatus provided with a balancer and a method for assembling the laundry treatment apparatus provided with the balancer.

Discussion of the Related Art

A conventional laundry treatment apparatus includes a cabinet forming an external appearance thereof, a tub installed in the cabinet so as to store water therein, and a drum rotatably installed in the tub so as to clean laundry. However, the drum may be eccentrically rotated without implementing dynamic equilibrium or dynamic balance according to the position of laundry contained in the drum. Dynamic equilibrium or dynamic balance may refer to a specific situation in which either centrifugal force produced by rotation of a rotary body or the sum of moments produced by the centrifugal force is set to zero ‘0’ about a rotary shaft. In case of rotating a rigid body, dynamic equilibrium or dynamic balance of the rotating rigid body can be maintained in the situation in which mass distribution of the rotating rigid body is uniform about the rotary shaft. However, if the above-mentioned ideal situation is not provided and the laundry treatment apparatus in which eccentric rotation of the drum unavoidably occurs is used, vibration may unavoidably occur in the drum due to an unbalance state caused by broken dynamic equilibrium and the vibration may be transmitted to the tub or cabinet, resulting in occurrence of noise.

In order to address the above issues, although a damper and a spring can be installed outside the tub, a balancer may be arranged at any of positions, for example, an upper part, a center part, or a lower end of the drum. A circulation passage may be disposed in the balancer, and a balance part (such as a ball or liquid) capable of circulating in the circulation passage may also be disposed in the balancer, resulting in formation of the resultant balancer. In this case, a method for controlling the balance part installed in the balancer to move in a direction opposite to the direction of eccentric movement caused by movement of laundry within the drum during movement of a rotation trajectory of the drum may be used to control such unbalance. Conventionally, in order to couple such balancer to the upper end of the drum, a fastening method using screws has been used. That is, after the lower end of the balancer is inserted into the top end of the drum, the top end of the drum (i.e., the top end of the body forming a body frame of the drum) may be screw-coupled to a lower part of the balancer.

However, whereas the conventional screw-fastening method can strongly and tightly couple the balancer to the drum using several screws, such screw-coupling can be easily released due to rotation, stoppage, switching, and vibration of the drum. If screw-coupling is released, the conventional screw-fastening method may cause internal constituent elements of the laundry treatment apparatus to be damaged or broken. In addition, an assembly time for screw-fastening increases, resulting in reduction in productivity.

SUMMARY OF THE INVENTION

Accordingly, the present disclosure is directed to a laundry treatment apparatus and a method for assembling the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present disclosure is to provide a laundry treatment apparatus which does not couple a balancer to an upper end of a drum using one or more screws, includes a protrusion formed at an outer surface of the balancer, bends the upper end of the drum, and couples the bent upper end of the drum to the protrusion, resulting in formation of the laundry treatment apparatus.

Another object of the present disclosure is to provide a laundry treatment apparatus provided with a balancer formed by deformation (redesign) of the protrusion so as to prevent the protrusion of the balancer from being damaged by problems encountered when the balancer is coupled to the upper end of the drum according to the above-mentioned bending-coupling method. For example, the above problems may include slippage caused by rotation, stoppage, switching or vibration of the drum due to loose connection between the balancer and the upper end of the drum, and damage of the protrusion of the balancer due to occurrence of bending-and-coupling force.

Another object of the present disclosure is to provide an assembly method for bending the upper end of the drum to be suitable for the outer surface of the balancer using a roller in a manner that the bent upper end of the drum is coupled to the outer surface of the balancer, and a laundry treatment apparatus using the assembly method.

Another object of the present disclosure is to provide a laundry treatment apparatus, in a situation in which damage or malfunction of connection between the balancer and the upper end of the drum occurs so that the balancer and the upper end of the drum are not fixed, configured to be used without replacement of the balancer.

To achieve these objects and other advantages and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, a laundry treatment apparatus includes a cabinet, a tub, a drum, a balancer, and a coupling part. The cabinet includes an inlet. The tub is disposed in the cabinet to provide a space in which water is stored, and includes an tub opening formed to communicate with the inlet. The drum includes a body rotatably disposed in the tub to provide a space in which laundry is stored, an drum opening formed to communicate with the tub opening, and a body through-hole disposed to pass through the body. The balancer includes a housing formed in a ring shape, a housing through-hole formed to pass through the housing while simultaneously communicating with the tub opening and the drum opening, a circulation passage disposed in the housing, fluid provided to circulate along the circulation passage, and a fastening part arranged along a circumferential surface of the housing, and coupled to the body. The coupling part located at an upper end of the body, and configured to be bent in a radial direction of the housing along an outer circumferential surface of the fastening part such that the coupling part is coupled to the fastening part.

The fastening part may protrude from an outer circumferential surface of the housing to a circumferential direction of the housing, and may be accommodated in the upper end of the body. The coupling part may be bent in a radial direction of the housing along the outer circumferential surface of the fastening part.

The fastening part may include a first fastening part formed by a top surface of the fastening part, a second fastening part formed by a side surface of the fastening part, a third fastening part formed by a bottom surface of the fastening part, a fourth fastening part formed to extend from an inner end of the third fastening part, and a fifth fastening part formed to extend from an end of the fourth fastening part to a bottom surface of the housing. The coupling part may include a first coupling part formed to contact the first fastening part, a second coupling part formed to extend from the first coupling part, and configured to contact the second fastening part, and a third coupling part formed to extend from the second coupling part, and configured to contact the third fastening part, the fourth fastening part, and the fifth fastening part. The third coupling part may include a first curved part formed to contact the third fastening part and the fourth fastening part, a planarization part formed to extend from the first curved part so as to contact the fifth fastening part, and a second curved part formed to extend from the planarization part so as to contact the body of the drum.

The end part of the first coupling part that is bent and coupled in a radial direction of the housing along an outer circumferential surface of the fastening part may be spaced apart from an outer circumferential surface of the housing by a predetermined separation distance.

At least one of contact between the first fastening part and the first coupling part, contact between the second fastening part and the second coupling part, and contact between the fifth fastening part and the planarization part may be surface-contact.

The first curved part may be formed in a curved shape such that both ends of the first curved part contact each of the third fastening part and the fourth fastening part.

The fastening part may include at least one protrusion to prevent slippage between the fastening part and the coupling part. The fastening part may have the same shape as the first coupling part to be coupled to the fastening part.

The protrusion may include a first contact part formed to extend from the fastening part, and configured to protrude in a height direction of the housing, a second contact part formed to extend from an end part of the first contact part, and configured to protrude in a direction parallel to a circumferential direction of the housing, and a third contact part formed to extend from an end part of the second contact part, and formed to protrude in the height direction of the housing such that the third contact part is in contact with the fastening part.

The first contact part may be tilted upward in a manner that the first contact part is in contact with the second contact part.

The third contact part may be tilted downward in a manner that the second contact part is connected to the first fastening part by the third contact part.

When the coupling part is bent and coupled to the fastening part, the fastening part may be damaged by external force. The laundry treatment apparatus may further include at least one reinforcement rib formed to protrude from the third fastening part so as to prevent damage of the fastening part, configured to extend in a direction from the housing to the drum, and connected to the housing.

The reinforcement rib may be formed in a tapered shape. The tapered shape may be configured in a manner that, as the reinforcement rib moves closer from an outer circumferential surface of the drum to an inner circumferential surface of the tub, a height of the reinforcement rib starting from a contact surface where the reinforcement rib contacts the third fastening part is gradually reduced.

Specifically, in the region in which the protrusion is contained, it is impossible for the reinforcement rib to have the same size as the reinforcement rib of the third fastening part in which the protrusion is not contained. The protrusion may include at least one protrusion reinforcement rib formed to protrude by contacting the second contact part and the housing by a predetermined length that is equal to or shorter than a length of the second contact part in a radial direction so as to prevent damage of the protrusion.

In the same manner as in the reinforcement rib, as the distance from the circumferential surface of the drum to an external part of the drum gradually increases, a height of the protrusion reinforcement rib is gradually reduced.

In addition, when the balancer is not fixed due to damage of the fastening part or the coupling part, the laundry treatment apparatus is unable to normally operate. In this case, the balancer or the drum can be replaced. The fifth fastening part may include at least one screw-fastening part such that the coupling part is screw-coupled to the fastening part.

The coupling part may include at least one screw-hole that passes through the planarization part and communicates with the screw-fastening part such that the coupling part is screw-coupled to the fastening part.

In accordance with another aspect of the present disclosure, a method for assembling a laundry treatment apparatus which includes a cabinet provided with an inlet, a tub disposed in the cabinet to provide a space in which water is stored, and provided with an tub opening formed to communicate with the inlet, a drum including a body rotatably disposed in the tub to provide a space in which laundry is stored, an drum opening formed to communicate with the tub opening, and a body through-hole disposed to pass through the body, a balancer including a housing formed in a ring shape, a housing through-hole formed to pass through the housing while simultaneously communicating with the tub opening and the drum opening, a circulation passage disposed in the housing, fluid provided to circulate along the circulation passage, and a fastening part arranged along a circumferential surface of the housing, and coupled to the body, and a coupling part located at an upper end of the body, and configured to be bent in a radial direction of the housing along an outer circumferential surface of the fastening part such that the coupling part is coupled to the fastening part, the method includes a first step in which the balancer is inserted through the drum opening, and a second step in which the coupling part is bent in a radial direction along the fastening part of the balancer so that the coupling part is coupled to the fastening part.

The second step may include bending the coupling part so that the bent coupling part is coupled to the fastening part using at least one of a roller rotating in the same direction as a rotary shaft of the drum and another roller rotating in another direction different from that of the rotary shaft of the drum.

The fastening part may include a first fastening part formed by a top surface of the fastening part and a second fastening part formed by a side surface of the fastening part. The coupling part may include a first coupling part contacting the first fastening part and a second coupling part extending from the first coupling part so as to contact the second fastening part. The second step may include performing, when the coupling part is bent and coupled to the fastening part, surface-contact between the first fastening part and the first coupling part and surface-contact between the second fastening part and the second coupling part.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The following device and assembly method may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present disclosure.

Referring toFIG. 1, the laundry treatment apparatus100according to the present disclosure may include a cabinet1, a tub2, a drum4, a balancer6, a fastening part63, and a coupling part415. The cabinet1may include an inlet11. The tub2may be disposed in the cabinet, and may include a tub opening21(or a tub inlet) forming a water storage space. The drum4may include a body41rotatably installed in the tub2so as to store the laundry, and a body through-hole413formed to pass through the body41. The balancer6formed in a ring shape may reduce noise and vibration by reducing unbalance of the drum4. The fastening part63may be provided in the balancer6. The coupling part415formed at the upper end of the body41may be bent in a radial direction of the balancer6along an outer circumferential surface of the fastening part, so that the coupling part415can be coupled to the fastening part63. The coupling part415may have a curled or curved shape.

The cabinet1may include an inlet11through which laundry can be supplied to the drum4and the laundry can be taken out of the drum4. The inlet11may include a door13rotatably installed in the cabinet1.

An adjustment part15may be installed at the bottom surface of the cabinet1. The adjustment part15may adjust the height or a horizontal plane of the cabinet1with respect to the ground (G) corresponding to the bottom surface of the space in which the laundry treatment apparatus will be installed.

The tub2may be provided in any of shapes in which water can be stored. The tub2may receive water through water-supply parts17and19, and may discharge water to the outside of the cabinet1through drain parts16and18. Preferably, the tub2may be formed in a cylindrical shape. The water-supply part may include a water-supply pipe connected to a water-supply source, and a valve19for opening or closing the water-supply pipe. The drain part may include a pump18for discharging water stored in the tub2to the outside of the tub2, and a drain pipe16for guiding water pressurized by the pump to the outside of the cabinet1.

The tub2may include a tub opening21formed to communicate with the inlet11, and may be fixed into the cabinet1through a tub support part3. Preferably, the tub support part3may be formed to absorb vibration generated in the tub2.

In other words, the tub support part3may include a first support part31provided in the cabinet1, a second support part33provided in the tub2, and a bar through which the first support part31is connected to the second support part33, such that vibrations applied to the tub2can be offset against each other by a compression spring. The tub support part3may further include a damper and the like to effectively reduce (or attenuate) noise.

The drum4may be implemented as the body41that is installed in the tub2and stores laundry. The body41may rotate in the tub2by a driver5, such that it is preferable that the body41be formed in a cylindrical shape.

The body41may include a drum opening411that is located in the same direction as the tub opening21of the tub2. A circumferential surface of the body41may be provided with at least one through-hole413through which water supplied to the tub2can flow into the body41.

The balancer6may include a ring-shaped housing64, a housing through-hole65, a circulation passage61, fluid, and a fastening part63. The ring-shaped housing62may be fixed to an upper end of the body41. The housing through-hole65may be formed to pass through the housing64, and may communicate with the drum opening411and the tub opening21. The circulation passage61may be provided in the housing64. The fluid may circulate along the circulation passage. The fastening part63may be provided along the circumferential surface of the housing64, and may be coupled to the body41.

The upper end of the body41may be bent in a radial direction of the housing64according to the outer circumferential surface of the fastening part63, resulting in formation of the coupling part415.

The housing64may be formed in a ring shape by assembling an upper housing to a lower housing. In addition, according to the method for assembling the balancer6, various pieces may be combined in a manner that the housing64can be formed in the ring shape. The housing64may include a balance part (such as a solid or liquid) movable within the circulation passage61. When a solid movable in the circulation passage61is used as the balance part, the housing64may be formed in a ball shape. When liquid movable in the circulation passage61is used as the balance part, water, high-density aqueous solution (salt water, etc.) or high-viscosity viscous fluid, etc. may be used as the liquid.

In addition, in order to calibrate the noise reduction and vibration attenuation function of the balancer6according to types of laundry, the balance part for use in the housing64can be replaced or supplemented. To this end, the housing64may include a means for replacing or supplementing the balance part. The circulation passage61of the balancer6may be formed in various shapes, and may be implemented as a plurality of circulation passages as needed.

The laundry treatment apparatus100according to the present disclosure may be implemented as any of a top loading laundry treatment apparatus in which the inlet11is located at a top surface of the cabinet1and a front loading laundry treatment apparatus in which the inlet11is located at a front side of the cabinet1.FIG. 1is a view illustrating the laundry treatment apparatus100implemented as the top loading laundry treatment apparatus. In this case, the inlet11may be located at the top surface of the cabinet1, the tub opening21may be located at the top surface of the tub2, and the drum opening411of the drum body41may be located at the top surface of the body41. The balancer6should be provided at the upper end of the body41.

The driver5provided in the top loading laundry treatment apparatus100may include a stator53, a rotor55, a rotary shaft51, and a shaft support part57. The stator53may be fixed to an outer bottom surface of the tub2, and may form a rotational magnetic field. The rotor55may rotate by the rotational magnetic field. The rotary shaft51may be provided to pass through the bottom surface of the tub2, and may couple the rotor55to the body41. The shaft support part57may be provided in the tub2so that the rotary shaft51can be rotatably supported.

Meanwhile, when the laundry treatment apparatus is implemented as the front loading laundry treatment apparatus, the inlet11, the tub opening21, and the drum opening411may be located at the front side of the cabinet1, the front side of the tub2, and the front side of the body41, respectively. There is a need for the balancer6to be provided at the front side of the body41. In this case, the body41of the drum should be arranged in a manner that the rotary shaft is arranged parallel to the ground G. There is a need for the driver5of the laundry treatment apparatus100to be composed of the stator, the rotary shaft, and the shaft support part. The stator may be fixed to a rear outer surface of the tub. The rotary shaft may connect the body to the rotor by passing through the rear side of the tub. The shaft support part may be provided in the tub and may rotatably support the rotary shaft.

The laundry treatment apparatus may perform a washing process and a dehydration process. In the washing process, after water is supplied to the laundry treatment apparatus through the water-supply parts17and19, the drum4may rotate through the driver5so that laundry contained in the drum4can be washed and rinsed using a vortex flow of water. In the dehydration process, water may be drained outside the tub2through the drain parts16and18, and the drum4may rotate through the driver4, such that laundry can be dehydrated. The laundry treatment apparatus may further include a controller for the washing process and the dehydration process.

The enlarged cross-sectional view ofFIG. 1illustrates an example of a connection between the fastening part63of the balancer6and the coupling part415of the body41. In the enlarged cross-sectional view, the circulation passage61may be implemented as two circulation passages (i.e., a first circulation passage611and a second circulation passage612) such that the first and second circulation passages611and612can more effectively regulate an unbalance state than the other case in which only one circulation passage is used.

The conventional screw-fastening method for coupling the balancer6to the body41using screws has disadvantages in that such screw-coupling is released due to high-speed rotation of the drum4, such that other constituent elements other than the balancer6and the body41may be broken or damaged and a long assembly time may be taken to interconnect the balancer6and the body41. In order to address the above-mentioned issues, the fastening part63where the balancer6meets and connects to the body41may protrude outward from the outer circumference of the housing64, and may be accommodated in the upper end of the body41. The coupling part415located at the upper part of the body41may be bent toward a central direction of the housing64along the outer circumferential surface of the fastening part63, so that the bent coupling part415can be connected to the fastening part63. The enlarged cross-sectional view ofFIG. 1is an example of such connection.

The above-mentioned embodiment will hereinafter be described with reference to the attached drawings. The above-mentioned connection may include a first fastening part631formed by a top surface created by protrusion of the fastening part63, a second fastening part632formed by a side surface of the fastening part63, a third fastening part633formed by a bottom surface of the fastening part63, a fourth fastening part634extending from an inner end of the third fastening part633, and a fifth fastening part635extending from the end of the fourth fastening part634to the bottom surface of the housing64. The coupling part415may include a first coupling part4151, a second coupling part4152, and a third coupling part4153. The first coupling part4151may contact the first fastening part631. The second coupling part4152may extend from the first coupling part4151, and may thus contact the second fastening part632. The third coupling part4153may extend from the second coupling part4152, and may thus contact the third fastening part633, the fourth fastening part634, and the fifth fastening part635. The third coupling part4153may include a first curved part4153a, a planarization part4153b, and a second curved part4153c. The first curved part4153amay be in contact with the third fastening part633and the fourth fastening part634. The planarization part4153bmay extend from the first curved part4153a, and may thus contact the fifth fastening part635. The second curved part4153cmay extend from the planarization part4153b, and may thus contact the body41.

In this case, the coupling part415may be bent toward the central direction of the housing64along the outer circumferential surface of the fastening part63, such that the bent coupling part415can be coupled to the fastening part63. Such coupling may be classified into simple connection and tight connection according to bending force levels. Specifically, at least one of contact between the first fastening part631and the first coupling part4151, contact between the second fastening part632and the second coupling part4152, and contact between the fifth fastening part635and the planarization part4153bmay be surface-contact. The first curved part4153amay contact the third fastening part633and the fourth fastening part634. In this case, only both ends of the first curved part4153amay contact the fourth fastening part634, and the remaining parts of the first curved part4153amay be smoothly curved. In order to prevent damage of a connection between the fastening part63and the coupling part415in consideration of the reinforcement rib6331to be described later, when the balancer6is accommodated in the upper end of the body41, the above-mentioned coupling structure may serve as a guide.

In addition, the end of the first coupling part4151and the outer circumference of the housing64may be spaced apart from each other by a predetermined distance. Here, the first coupling part4151may be bent toward a central direction of the housing64along the outer circumferential surface of the fastening part63. As a result, when the fastening part63is coupled to the coupling part415, occurrence of the housing64damaged by the end of the first coupling part4151can be prevented.

When the coupling part415is bent toward a central direction of the housing64along the outer circumferential surface of the fastening part63and is then connected to the fastening part415, such connection between the coupling part415and the fastening part415is incompletely achieved, such that slippage between the fastening part63and the coupling part415may occur. It is impossible for the balancer6to normally operate due to slippage between the balancer6and the body41. In severe cases, the balancer6or the body41may be broken or damaged.

In order to prevent the slippage problem, the fastening part631may include at least one protrusion5311, and the first coupling part4151to be coupled to the fastening part63may have a shape corresponding to the fastening part63. That is, unevenness may be formed to prevent such slippage. Although the first coupling part4151can be pre-molded to have a shape corresponding to the protrusion6311of the first fastening part, the first coupling part4151may be formed to have a shape corresponding to the protrusion6311in the above process of bending and coupling the first fastening part631. As a result, in the assembly process (rolling-based fabrication) for allowing the first coupling part4151to be in closer contact with the first fastening part631, the above-mentioned shape of the first coupling part4151can be naturally formed in a pressed manner.

FIG. 2illustrates the appearance in which at least one protrusion6311is arranged along the outer side surface of the housing64of the balancer6, and the enlarged view of the protrusion6311. As described above, the protrusion of the fastening part63may include a first contact part6311a, a second contact part6311b, and a third contact part6311c. In more detail, the protrusion of the fastening part63may extend along the outer side surface of the housing64so that the first contact part6311amay protrude upward from the housing64. The second contact part6311bmay extend from the end of the first contact part6311a, and may protrude in a direction parallel to the circumferential surface of the housing64. The third contact part6311cmay extend from the end of the second contact part6311b, may protrude in the height direction of the housing64, and may thus contact the fastening part63. In this case, during rotation, stoppage, and switching of the drum4, the protrusion6311may protrude from the fastening part63, so that slippage between the balancer6and the body41can be prevented.

FIGS. 3 and 4are enlarged views illustrating examples of the protrusion formed at a side surface of the balancer6according to the present disclosure. The first coupling part4151may be pre-molded to have a shape corresponding to the protrusion6311, such that the first coupling part4151can be coupled in the corresponding shape. However, when the first coupling part4151is bent and coupled to the first fastening part631without pre-molding of the first coupling part4151, the protrusion6311of the fastening part63is formed, resulting in formation of the shape corresponding to the protrusion shape of the first coupling part4151. In this case, the fastening part63and the coupling part4151can be tightly connected to each other, the assembly process (fabrication based on roller rotation) capable of successively performing the above operations to reduce the assembly time may be applied to the first contact part and the third contact part, so that the first contact part and the third contact part can be deformed. Roller-based process will be described with reference toFIGS. 8 and 9. The first contact part6311acorresponding to a portion in which the roller is inserted may be tilted upward so as to facilitate movement of the roller. In addition, the third contact part6311cmay also be tilted downward in consideration of movement of the roller moving in another direction opposite to the movement direction of the roller as needed.

If the coupling part415is bent toward a central direction of the housing64along the outer circumferential surface of the fastening part63and is coupled to the coupling part415, force capable of bending the coupling part415is needed, such that the protruded fastening part63may be broken or damaged. In order to prevent such damage of the fastening part63and to increase rigidity of the fastening part63, the bottom surface of the fastening part63(i.e., the third fastening part633) may further include the reinforcement rib6331. In more detail, the fastening part63may further include at least one reinforcement rib6331that contacts the third fastening part633and the housing64and protrudes from the housing64to the drum4.FIG. 5is an enlarged view illustrating an example of the reinforcement rib6331that is provided at a back surface of the balancer6and a side surface of the balancer6. The reinforcement rib6331ofFIG. 5may be formed in a tapered shape. That is, as the distance from the reinforcement rib6331to the outside of a radial direction of the third fastening part633increases, the height of the reinforcement rib6331starting from the contact surface where the reinforcement rib6331contacts the third fastening part is gradually reduced, resulting in formation of a tapered shape.

FIG. 6is an enlarged view illustrating the protrusion6311provided at a side surface of the balancer6and an example of the protrusion reinforcement rib6311dwhen viewed in a contact surface between the protrusion6311and the housing64. In a specific region in which the protrusion6311is contained, it is impossible for the housing64to have the same size as the reinforcement rib of the third fastening part633in which the protrusion6311is not contained. In order to prevent damage of the protrusion6311, it is possible to use at least one reinforcement rib6311dwhich contacts the second contact part6311band the housing64in a radial diameter direction by a predetermined length identical to or shorter than a length of the second contact part6311bin a radial direction.

In addition, the protrusion reinforcement rib6311dmay include at least one protrusion reinforcement rib6311din which a maximum height from the surface contacting the second contact part6311bto the lower end of the protrusion reinforcement rib6311dis equal to or shorter than the height from the surface contacting the second contact part6311bto the third fastening part633in which the protrusion6311is not contained. In this case, the height from the surface contacting the second contact part6311bto the third fastening part633may refer to the distance from the surface contacting the second contact part6311bto a virtual extension line of the third fastening part633of the region (having no protrusion) linearly extending downward from the protrusion reinforcement rib6311d.

In addition, the protrusion reinforcement rib6311dmay include at least one protrusion reinforcement rib6311din the same manner as in the reinforcement rib6331. In this case, the at least one protrusion reinforcement rib6311dmay be formed in a tapered shape. That is, as the distance from the protrusion reinforcement rib6311dto the outside of a radial direction of the second contact part6311bincreases, the height of the protrusion reinforcement rib6331dstarting from the surface contacting the second contact part6311bis gradually reduced, resulting in formation of the tapered shape.

In order to prevent slippage, only the first fastening part631may be formed to protrude toward the inlet11to result in formation of uneven parts, instead of using the entire fastening part bent to result in such uneven parts. The third fastening part unrelated to the protruded uneven parts of the first fastening part631may be arranged in a manner that all surfaces of the third fastening part are located at the same plane without change, so that the protrusion reinforcement rib6311dmay have the same shape as the reinforcement rib6331.

FIG. 7is a cross-sectional view illustrating an example of a connection between the fastening part63and the coupling part415. The coupling part415may be bent in a radial direction of the housing64along the outer circumferential surface of the fastening part63so that the coupling part of the coupling part415is broken or damaged. As a result, it may be necessary for the balancer6or the body41to be replaced with another. In this case, a screw-fastening part636may be provided to the fifth fastening part635so as to easily fix the balancer6to the body41without using such replacement. The planarization part4153bof the third coupling part4153coupled to the fifth fastening part635may further include a screw hole4153dformed to communicate with the screw-fastening part636.

In still another embodiment, although not shown in the drawings, in order to fix the fastening part63and the coupling part415to each other, screws or rivets may be used to interconnect the first coupling part4151and the fastening part63. Besides, other coupling methods for fixing the fastening part63to the coupling part415can also be applied as needed.

FIG. 8is a schematic view illustrating a method for assembling the fastening part63to the coupling part415according to the present disclosure. The coupling process in which the upper end of the body41is bent and coupled to the balancer6may include a first process and a second process. In the first process, the balancer6may be inserted into the upper end of the body. In the second process, the coupling part415may be bent toward a central direction of the housing64along the outer circumferential surface of the fastening part63. Specifically, for continuous and stronger connection in the second process, the rolling process based on rotation of the first roller81may be used. In other words, the above-mentioned process may refer to a process in which the first coupling part4151, the second coupling part41521or the third coupling part4153is bent and pressed during rolling of the first roller81. By the above-mentioned process, the first coupling part4151may be molded with the shape of the protrusion6311formed in o the fastening part63, such that the resultant first coupling part4151may be in closer contact with the fastening part63. To this end, at least one roller may enter the same direction as the rotary shaft of the drum4in a manner that the coupling part415is bent to contact the third fastening part633and the second fastening part632. The bent coupling part415may be bent again, so that the re-bent coupling part415may contact the first fastening part631in a manner that the first coupling part415is coupled to the fastening part63. The above-mentioned processes may be sequentially or simultaneously performed by the rolling parts8141and8142of the head814of the first roller81. When the above-mentioned processes are sequentially performed, the coupling part415may be bent using the first rolling part8141, so that the end of the third fastening part633can be coupled to the second fastening part632. Thereafter, when the first roller81moves toward the balancer6, the coupling part415is coupled to the first fastening part631using the first rolling part8141, and is re-coupled to the second fastening part632using the second rolling part8142. In addition, the above-mentioned second step may be repeatedly performed using the first roller81.

In addition, in order to evenly distribute the bending-coupling force of the first coupling part4151by the first roller81, a roller support812may be provided to the rotary shaft811of the first roller81, and the roller support812is coupled to the top surface of the roller head814through one or more springs, such that necessary force can be constantly transferred.

In addition, as described above, the length (d3) of the first coupling part4151is shorter than the length (d1+d3) of the first fastening part631, such that damage of the housing64can be prevented in the second process due to the predetermined separation distance (d3), resulting in formation of the resultant coupling part4151.

FIG. 9is a schematic view illustrating a method for assembling the fastening part63to the coupling part415according to the present disclosure. When performing the second process using only one first roller81, the fastening part63may not be easily coupled to the coupling part415, so that the rolling process should be repeatedly performed, resulting in consumption of a long assembly time taken to perform such assembly process. As a result, the second processes should be simultaneously performed using several rollers.FIG. 9illustrates an embodiment implemented using two rollers from among various assembly methods. Although two rollers are used in the embodiment ofFIG. 9, the scope or spirit of the present disclosure is not limited thereto, and many more rollers can also be applied to the present disclosure as needed. The first roller81may enter the same direction as the rotary shaft of the drum4in a manner that the coupling part415is bent to contact the third fastening part633and the second fastening part632. The resultant coupling part415may be re-bent to contact the first fastening part631, such that the coupling part415can be coupled to the fastening part63. In addition, the second roller82may enter in the direction diagonal to the rotary shaft of the drum4, the first coupling part4151may be bent and coupled to the first fastening part631such that the first coupling part4151can more closely contact the first fastening part631.

As is apparent from the above description, the laundry treatment apparatus according to the embodiments of the present disclosure may not couple the balancer to the upper end of the drum using one or more screws, may include a protrusion formed at an outer surface of the balancer, may bend the upper end of the drum, and may couple the bent upper end of the drum to the protrusion, resulting in formation of the laundry treatment apparatus.

The laundry treatment apparatus according to the embodiments of the present disclosure may include a balancer formed by deformation (redesigning) of the protrusion so as to prevent the protrusion of the balancer from being damaged by problems encountered when the balancer is coupled to the upper end of the drum according to the above-mentioned bending-coupling method. For example, the above problems may include slippage caused by rotation, stoppage, switching or vibration of the drum due to loose connection between the balancer and the upper end of the drum, and damage of the protrusion of the balancer due to occurrence of bending-and-coupling force.

The embodiments of the present disclosure may provide an assembly method for bending the upper end of the drum to be suitable for the outer surface of the balancer using a roller in a manner that the bent upper end of the drum is coupled to the outer surface of the balancer, and may also provide a laundry treatment apparatus using the assembly method.

In a situation in which damage or malfunction of connection between the balancer and the upper end of the drum occurs so that the balancer and the upper end of the drum are not fixed, the laundry treatment apparatus according to the embodiments of the present disclosure can be used without replacement of the balancer or the drum.