WO2005111295A1

WO2005111295A1 - Drum for washing machine

Info

Publication number: WO2005111295A1
Application number: PCT/KR2005/001282
Authority: WO
Inventors: Deug Hee Lee; Seung Bong Choi; Young Soo Kim
Original assignee: Lg Electronics Inc.
Priority date: 2004-05-15
Filing date: 2005-05-03
Publication date: 2005-11-24
Also published as: CN100529237C; EP1747314B1; CN1898431A; US20050252252A1; EP1747314A1

Abstract

Disclosed is (30) a drum for a washing machine having improved strength. The drum (30) for a washing machine includes a center comprising a cylindrical body(30), a back(46) coupled to a back portion of the center(30), a front(44) coupled to a front portion of the center(30) and having an opening (44), a recess formed at the back (46) and configured to accommodate a spider(32) connected to a driving shaft (33), and at least one bent portion(52,53,54) formed at the back(46) and projecting backwardly.

Description

Description DRUM FOR WASHING MACHINE Technical Field

[1] The present invention relates to a washing machine, and more particularly to a drum installed in the washing machine. Background Art

[2] Generally, a washing machine is an apparatus for washing a laundry and includes a drum rotatably provided within a housing and a driving device for rotating the drum. The washing machine is classified into a top loading type and a front loading type according to a posture of the drum. The front loading type washing machine includes a drum that is laid down, whereas the top loading type washing machine has an upright drum. Hence, the laundry is inputted to the front loading type washing machine via a front side thereof. Compared to the top loading type washing machine, the front loading type washing machine has a smaller volume and a bigger washing capacity. Further, the front loading type washing machine has high washing performance without an entanglement of the laundry, and thus is popular in use.

[3] In such front lading type washing machine, the drum could comprise a single injection-molded structure. However, in view of vibration and collision against a tub during a rotation, it is has been common that the drum is comprised of a plurality of members having appropriate strength, specifically a center unit and front and back units coupled to front and rear portions of the center unit respectively.

[4] However, as the back unit usually comprises a simple disk member, it has low strength and a small friction surface against the laundry in the drum. For the same reason, the front unit has a low strength as well. Accordingly, the conventional drum does not have sufficient strength. Disclosure of Invention Technical Problem

[5] Accordingly, the present invention is contemplated to substantially obviate one or more problems due to limitations and disadvantages of the related art.

[6] An object of the present invention is to provide a drum for a washing machine having increased strength.

[7] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. Technical Solution

[8] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the present invention provides a drum for a washing machine comprising a center comprising a cylindrical body; a back coupled to a back portion of the center; a front coupled to a front portion of the center and having an opening; a recess formed at the back and configured to accommodate a spider connected to a driving shaft; and at least one bent portion formed at the back and projecting backwardly.

[9] The recess projects forwardly from the back, and thus is formed by pressing the back.

[10] The bent portion is formed within the recess, and is formed by pressing the back. The bent portion comprises inclined portions which are inclined opposite to each other and disposed continuously in a radial direction of the back, and substantially has a triangular section.

[11] Preferably, a diameter of the opening is 0.65-0.75 times of a diameter of the front.

[12] In addition, a bent portion is formed in a circumferential direction between the opening and an edge of the front, and a distance between the bent portion and the opening is shorter than a distance between the bent portion and an edge of the front.

[13] More specifically, the front comprises a first extension formed at an edge of the front, a second extension extending from the first extension toward a center of the front and bent forwardly to be inclined, and a third extension extending from the second extension toward the center of the front. Preferably, the third extension is smaller than the first extension. A distance from an outer circumference of the first extension to an outer circumference of the third extension is 2/3 of a distance from the outer circumference of the first extension to an inner circumference of the third extension. Additionally, a distance from an outer circumference of the first extension to an outer circumference of the third extension is 1/2 of a distance from the outer circumference of the first extension to an inner circumference of the third extension. Further, preferably, the second extension has a predetermined curvature.

[14] Alternatively, according to another aspect of the invention, a drum for a washing machine comprises a center comprising a cylindrical body, a back coupled to a back portion of the center, a front coupled to a front portion of the center and having an opening, a bent portion formed in a circumferential direction between the opening and an edge of the front, wherein a distance between the bent portion and the opening is shorter than a distance between the bent portion and an edge of the front. Advantageous Effects [15] By the present invention mentioned above, strength of the drum is substantially increased. Brief Description of the Drawings

[16] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

[17] FIG. 1 is a side sectional view showing a washing machine according to the present invention;

[18] FIG. 2 is a exploded perspective view showing a drum and a spider of FIG. 1;

[19] FIG. 3 is a front view showing a back of a drum according to the present invention;

[20] FIG. 4 is a partial sectional view taken along a line I-I of FIG. 3;

[21] FIG. 5 is a front view showing a front of a drum according to the present invention;

[22] FIGS. 6 and 7 are a front view and a sectional view each showing a front of a drum according to the present invention;

[23] FIGS. 8 and 9 are a front view and a sectional view each showing a modification of a front in a drum according to the present invention; and

[24] FIG. 10 is a sectional view showing another modification of a front in a drum according to the present invention. Best Mode for Carrying Out the Invention

[25] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In describing the embodiments of the present invention, same parts will be given the same names and reference numerals, and iterative description of which will be omitted.

[26] FIG. 1 is a side sectional view showing a washing machine according to the present invention, and FIG. 2 is an exploded perspective view showing a drum and a spider of FIG. 1.

[27] In the washing machine of the present invention, a cabinet 4 is disposed on a base 2, a top cover 6 is disposed on the cabinet 4, and a front cover 8 is disposed in front of the cabinet 4. An entrance 9 is formed at the front cover 8, and a door 10 is rotatably installed at the front cover 8 to close or open the entrance 9. A laundry m is put into or taken out of the washing machine through the entrance 9. A control panel 12 for allowing a user to operate the washing machine is installed to the top cover 6.

[28] A tub 14 is installed in the cabinet 4 in order to store washing water. The tub 14 is connected to a damper 3 installed on the base 2 and is hung on springs 5 installed at both sides of the cabinet 4. An opening 16 is formed at the tub 14 to be positioned in the rear of the entrance 9. An inlet 18 is formed at an upper portion of the tub 14 to supply the washing water w to the tub 14, and an outlet 20 is formed at a lower portion of the tub 14 to discharge the washing water w out of the tub 14. In addition, a gasket 22 is mounted between the tub 14 and cabinet 4 to be closely attached to the door 10 and thus prevents a leakage of the washing water w.

[29] A motor 24 is mounted to a back portion of the tub 14 to rotate a drum 30. The motor 24 is comprised of a stator 26 fixed to a bask surface of the tub 14 and a rotor 28 surrounding the stator 26.

[30] The drum 30 is rotatably installed in the tub 14 and is connected to the motor 24 by a spider 32. As shown in FIG. 2, the spider 32 is fixed to a back portion of the drum 30 and is coupled to a shaft 33 connected to the motor 24. The spider 32 includes a hub 34 coupled to the shaft 33 and a plurality of arms 35, 36, and 37 extending in a radial direction from the hub 34. The arms 35, 36, and 37 are fastened to the back portion of the drum 30 using a fastening member such as a bolt. Further, the drum 30 has lifters 40 mounted on an inner circumferential surface and a plurality of holes 41 and 45, which are formed at circumferential portion and the back portion of the drum and allow the water and the air to flow in or out of the drum.

[31] A reference numeral 60 designates a supplying valve connected to an outer hose 58 and controlling the water supplied by the outer hose 58, and a reference numeral 62 designates a supplying hose guiding the water from the supplying valve 60 to the tub 14. A reference numeral 64 designates a detergent box mixing a detergent and the water supplied by the supplying hose 62, and a reference numeral 66 designates a bellows pipe guiding the water from the detergent box 64 to the inlet 18 of the tub 14.

[32] A reference numeral 70 designates a bellows pipe connected to the outlet 20 of the tub 14 for discharging the washing water w in the tub 14, a reference numeral 72 designates a pump pumping the water in the bellows pipe 70, and a reference numeral 74 designates a discharge hose connected to the pump 72 and discharging the pumped water out of the washing machine.

[33] In the washing machine of the present invention, the drum 30 is configured to have sufficient strength in order to endure vibration and impact given thereto, and will be explained in detail as follows.

[34] As shown in FIG. 2, the drum 30 comprises a center 42 of a cylindrical body, a front 44 coupled to a front portion of the center 42, and a back 46 coupled to a back portion of the center 42. The plurality of holes 41 and 45 are formed at the center 42 and the back 46 respectively. Further, an opening 43 is formed at the front 44, and the laundry is put into the drum 30 through the opening 43.

[35] A recess 50 is formed at the back 46 to accommodate the spider 32, as shown in FIGS. 2 and 3. The recess 50 has the same shape as the spider 32, such that the spider 32 is tightly coupled to the back 46. Specifically, the recess 50 is formed to ac- commodate the arms 35, 36, and 37 of the spider 32. In addition, the recess 50 is formed at the back 46 comprised of a disk member by a press working, and thus projects forwardly from the back 46 as shown in FIG. 2. Therefore, a friction surface of the back 46 against the laundry is increased by the projecting recess 50, and a washing efficiency of the drum 30 is improved. Further, a deformation inherently given by a formation of the recess substantially increases strength and stiffness of the back 46 in both of circumferential and radial directions thereof.

[36] Additionally, bent portions 52, 53, and 54 are formed projecting backwardly at the back 46. If the bent portions 52, 53, and 54 are formed outside the recess 50, this causes the portion at which the holes 45 are formed to be reduced. Accordingly, the bent portions 52, 53, and 54 are disposed within the recess 50, and preferably are distributed respectively in portions of the recess 50 accommodating the arms 35, 36, and 37. Similar to the recess 50, the bent portions 52, 53, and 54 are formed by pressing the back 46. More specifically, as shown in FIG. 4, the bent portions 52, 53, and 54 includes inclined portions 53a and 53b which are disposed continuously in a radial direction of the back 46 and are inclined opposite to each other. These bent portions 52, 53, and 54 generally each have a triangular cross section and thus each include a peak 53c. If each of the bent portions 52, 53, and 54 has a rectangular cross section, the laundry could be stuck into such bent portions 52, 53, and 54. However, as the laundry slips on the inclined portions 53a and 53b, the laundry would not be stuck i n the bent portions 52, 53, and 54 as shown. In addition, due to the bent portions 52, 53, and 54, the friction surface to the laundry is increased and the strength and the stiffness are increased as well. Furthermore, as indicated as "A" in FIG. 1, the bent portions 52, 53, and 54 serve to expand an inner space of the drum 30. Accordingly, more laundry m could be entered into the drum 30.

[37] An edge 56 of the back 46 is, as shown in FIG. 1 bent forwardly and then bent backwardly so as to be coupled to the center 42. That is, the edge 56 is curled. Such a curled edge 56 makes a coupling with the center 42 strong and increases the strength of the back 46.

[38] Meanwhile, in the front 44, as the opening 43 becomes larger, the laundry could be easily put into or taken out of such drum 30, but the strength of the drum 30, especially of the front 44 is lowered. Therefore, a size of the opening 43 should be set to allow the laundry to be easily put into or taken out of the drum 30, and simultaneously to let the drum 30 to have proper strength. In view of such condition, as shown in FIG. 5, it is preferable that a diameter d of the opening 43 is set to be 0.65-0.75 times of a diameter D of the front 44. The opening 43 set as such gives the drum 30 the proper strength, and permits big laundry such as a blanket to be introduced into or taken out of the drum 30. Accordingly, the user can use the washing machine conveniently, and the damage and the deformation of the drum 30 are prevented.

[39] In addition, in order to increase the strength of the front 44, a bent portion is formed between an edge and the opening 43 of the front 44 as shown in FIG. 6-10. The front 44 comprises a first extension 61 formed at the edge of the front 44, a second extension 62 extending from the first extension 61 toward a center of the front 44, and a third extension 63 extending from the second extension 62 toward the center of the front 44. The second extension 62 is bent forwardly and is inclined by a predetermined angle, while the first and third extensions 61 and 63 are formed flat. Substantially, the second extension 62 serves as the bent portion for enhancing the strength of the front 44 as mentioned above. Accordingly, even if the impact and the vibration are given to the drum 30, the deformation and the breakage are minimized due to the second extension 62.

[40] Further, the front 44 has a fourth extension 64 extending forwardly from the third extension 63. This fourth extension 64 has a cylindrical shape and comprises an entrance for the opening 43. An edge 65 of the fourth extension 64 is curled outwardly. Therefore, the edge 65 reinforces the strength of the drum 30, and does not damage the laundry while the laundry is put into or taken out of the drum 30. An edge 66 of the front 44 is bent forwardly and then bent backwardly so as to be coupled with center 42. That is, the edge 66 is curled to enclose a front portion of the center 42. This curled edge 66 makes a coupling with the center 42 and increases the strength of the front 44.

[41] More specifically, as shown in FIGS. 6 and 7, a distance 1 from an outer circumference of the first extension 61 to an outer circumference of the third extension 63 is set to be 2/3 of a distance L from the outer circumference of the first extension 61 to an inner circumference of the third extension 63. That is, a distance from an edge of the front 44 to the bent portion 62 is substantially set to be 2/3 of a distance from the edge of the front 44 to the opening 43. Due to a setting of the distance as such, the third extension 63 becomes smaller than the first extension 61, and in other words, a distance between the bent portion 62 and the opening 43 becomes shorter than a distance between the bent portion 62 and the edge of the front 44. If a force is given to a portion around the opening 43, the deformation could be occurred by a moment at the second extension 62, i.e. the bent portion. In this case, such moment is defined as a multiplication of a distance from the opening 44 to the second extension 62 and the force given to the opening 44 (actually, the fourth extension 64 or the portion around the opening 43). Accordingly, since a decrease of the third extension 63 causes a decrease of the length required for the moment and a decrease of the moment thereby, strength of the second extension 62 is relatively increased and a deformation of the second extension 62 is minimized. Meanwhile, a size of the third extension 63 needs to be slightly increased in order to uniformly improve an entire strength of the front 44. Therefore, as shown in FIGS. 8 and 9, the distance 1 from the outer circumference of the first extension 61 to the outer circumference of the third extension 63 is set to be 1/2 of the distance L from the outer circumference of the first extension 61 to an inner circumference of the third extension 63. That is, the distance from the edge of the front 44 to the bent portion, i.e. the second extension 62 is substantially set to be 1/3 of the distance from the edge to the opening 43. Due to a setting of the distance as such, the third extension 63 becomes slightly larger, and thus the strength of the front 44 is made to be entirely uniform.

[42] Additionally, as shown in FIG. 10, the second extension 62 preferably has a predetermined curvature. That is, the second extension 62 roundly extends forwardly. When the laundry m adjacent to the front 44 is taken out of the drum 30, this second extension 62 allows the laundry m to slide thereon. Accordingly, the laundry m is easily taken out of the drum 30 by the second extension 62.

[43] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

[I] A drum for a washing machine comprising: a center comprising a cylindrical body; a back coupled to a back portion of the center; a front coupled to a front portion of the center and having an opening; a recess formed at the back and configured to accommodate a spider connected to a driving shaft; and at least one bent portion formed at the back and projecting backwardly. [2] The drum according claim 1, wherein the recess is configured to increase a friction surface against a laundry in the drum. [3] The drum according claim 1, wherein the recess projects forwardly from the back. [4] The drum according claim 1, wherein the recess is formed by pressing the back.

[5] The drum according claim 1, wherein the recess has the same shaped as the spider. [6] The drum according claim 1, wherein the recess accommodates arms of the spider. [7] The drum according claim 1, wherein the bent portion is configured to a friction surface against a laundry in the drum. [8] The drum according claim 1, wherein the bent portion is formed within the recess. [9] The drum according claim 1, wherein the bent portion is formed by pressing the back. [10] The drum according claim 1, wherein the bent portion comprises inclined portions which are inclined opposite to each other and disposed continuously in a radial direction of the back.

[I I] The drum according claim 1, wherein the bent portion has a triangular section. [12] The drum according claim 1, wherein the bent portion has a peak.

[13] The drum according claim 1, wherein an edge of the back is curled to be coupled with the center.

[14] The drum according claim 1, wherein a diameter of the opening is 0.65-0.75 times of a diameter of the front.

[15] The drum according claim 1, wherein a bent portion is formed in a circumferential direction between the opening and an edge of the front

[16] The drum according claim 15, wherein a distance between the bent portion and the opening is shorter than a distance between the bent portion and an edge of the front. [17] The drum according to claim 15, wherein a distance from the edge of the front to the bent portion is 2/3 of a distance from the edge of the front to the opening.

[18] The drum according to claim 15, wherein a distance from the edge of the front to the bent portion is 1/2 of a distance from the edge of the front to the opening.

[19] The drum according to claim 1, the front comprises: a first extension formed at an edge of the front; a second extension extending from the first extension toward a center of the front and bent forwardly to be inclined; and a third extension extending from the second extension toward the center of the front.

[20] The drum according to claim 19, wherein the third extension is smaller than the first extension.

[21] The drum according to claim 19, wherein a distance from an outer circumference of the first extension to an outer circumference of the third extension is 2/3 of a distance from the outer circumference of the first extension to an inner circumference of the third extension.

[22] The drum according to claim 19, wherein a distance from an outer circumference of the first extension to an outer circumference of the third extension is 1/2 of a distance from the outer circumference of the first extension to an inner circumference of the third extension.

[23] The drum according to claim 19, wherein the front further comprises a fourth extension extending forwardly from the third extension and defining an entrance for the opening.

[24] The drum according to claim 23, wherein an edge of the fourth extension is curled.

[25] The drum according to claim 1, wherein an edge of the front is curled to be coupled with the center.

[26] The drum according to claim 19, wherein the second extension has a predetermined curvature.

[27] A drum for a washing machine comprising: a center comprising a cylindrical body; a back coupled to a back portion of the center; a front coupled to a front portion of the center and having an opening; a bent portion formed in a circumferential direction between the opening and an edge of the front, wherein a distance between the bent portion and the opening is shorter than a distance between the bent portion and an edge of the front.

[28] The drum according to claim 27, wherein a distance from the edge of the front to the bent portion is 2/3 of a distance from the edge of the front to the opening. [29] The drum according to claim 27, wherein a distance from the edge of the front to the bent portion is 1/2 of a distance from the edge of the front to the opening.

[30] The drum according to claim 27, the front comprises: a first extension formed at an edge of the front; a second extension extending from the first extension toward a center of the front and bent forwardly to be inclined; and a third extension extending from the second extension toward the center of the front.

[31] The drum according to claim 30, wherein the third extension is smaller that the first extension.

[32] The drum according to claim 30, wherein a distance from an outer circumference of the first extension to an outer circumference of the third extension is 2/3 of a distance from the outer circumference of the first extension to an inner circumference of the third extension.

[33] The drum according to claim 30, wherein a distance from an outer circumference of the first extension to an outer circumference of the third extension is 1/2 of a distance from the outer circumference of the first extension to an inner circumference of the third extension.

[34] The drum according to claim 30, wherein the front further comprises a fourth extension extending forwardly from the third extension and defining an entrance for the opening.

[35] The drum according to claim 34, wherein an edge of the fourth extension is curled.

[36] The drum according to claim 27, wherein an edge of the front is curled to be coupled with the center.

[37] The drum according to claim 30, wherein the second extension has a predetermined curvature.

[38] The drum according to claim 27, wherein a diameter of the opening is 0.65-0.75 times of a diameter of the front.