# US 2014/0190218 A1 · Balancer and washing machine having the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190218 A1 - Document ID: US20140190218A1 - Status: Published application - Kind: A1 - Application number: 14/143,266 - Filed: 2013-12-30 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Dong Ha JUNG; Jeong Hoon Kang; Min Sung Kim; Doo Young Rou - Web page: https://patentgrep.com/patent/US20140190218A1 ## CPC - D06F 37/225: {Damping vibrations by displacing, supplying or ejecting a material, e.g. liquid, into or from counterbalancing pockets} - D06F 37/20: Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations - F16F 15/167: having an inertia member, e.g. ring - Y10T 74/2122: with fluid balancing means - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A washing machine includes a cabinet, a drum rotatably arranged within the cabinet, an annular recess provided in the drum, and a balancer to offset an unbalanced load caused within the drum during rotation of the drum. The balancer includes a balancer housing mounted to the recess and has an annular channel therein, at least one mass movably disposed in the channel, and at least one ball disposed between the balancer housing and the mass to generate rolling motion. ## Claims ### Claim 1 A washing machine comprising: a cabinet; a drum rotatably arranged within the cabinet; an annular recess provided in the drum; and a balancer to offset an unbalanced load caused within the drum during rotation of the drum, wherein the balancer comprises a balancer housing mounted to the recess and having an annular channel therein; at least one mass movably disposed in the channel; and at least one groove formed on an inner surface of the balancer housing and accommodating the mass so as to restrict the mass moving along the channel when an RPM of the drum is within a specific RPM range. ### Claim 2 (depends on 1) The washing machine according to claim 1, wherein the groove is configured of at least two grooves which are arranged to be spaced apart from each other in a circumferential direction of the balancer housing. ### Claim 3 (depends on 1) The washing machine according to claim 1, wherein the groove is elongated in a circumferential direction of the balancer housing so as to accommodate at least two masses. ### Claim 4 (depends on 1) The washing machine according to claim 1, wherein the groove is configured of at least two grooves which are symmetrically arranged on the basis of an imaginary line passing through a center of rotation of the drum. ### Claim 5 (depends on 1) The washing machine according to claim 1, wherein the balancer housing comprises: a first housing opened at one side thereof; and a second housing covering the first housing to form the annular channel, and wherein the groove is formed in the first housing. ### Claim 6 (depends on 1) The washing machine according to claim 1, wherein the balancer housing comprises: a first inner surface and a second inner surface facing each other; and a third inner surface connecting the first and second inner surfaces, and wherein the groove is formed on at least one of the first to third inner surfaces. ### Claim 7 (depends on 6) The washing machine according to claim 6, wherein: a distance between a center of the balancer housing and the second inner surface is greater than that between the center of the balancer housing and the first inner surface; and the groove is formed on the first inner surface. ### Claim 8 (depends on 1) The washing machine according to claim 1, wherein both ends of the groove are provided with support portions to prevent the mass from being decoupled from the groove when an RPM of the drum is within a specific RPM range. ### Claim 9 (depends on 1) The washing machine according to claim 1, wherein the groove comprises at least one inclined surface which is obliquely formed inward of the channel. ### Claim 10 (depends on 9) The washing machine according to claim 9, wherein the groove further comprises at least one flat surface, and the inclined surface comprises a first inclined surface and a second inclined surface connected at both ends of the flat surface. ### Claim 11 (depends on 10) The washing machine according to claim 10, wherein a first inclined angle defined by the flat surface and the first inclined surface differs from a second inclined angle defined by the flat surface and the second inclined surface. ### Claim 12 (depends on 1) The washing machine according to claim 1, wherein the mass has a spherical shape. ### Claim 13 (depends on 1) The washing machine according to claim 1, further comprising a fluid accommodated in the channel to damp movement of the mass. ### Claim 14 A washing machine comprising a cabinet, a drum rotatably arranged within the cabinet, and a balancer which is coupled to the drum and offsets an unbalanced load caused within the drum during rotation of the drum, wherein the balancer comprises a balancer housing having an annular channel therein; and at least one mass movably disposed in the channel, and wherein the channel comprises at least one cross-section increasing portion having an increased cross-sectional area such that the cross-section increasing portion restricts the mass moving along the channel when an RPM of the drum is within a specific RPM range. ### Claim 15 (depends on 14) The washing machine according to claim 14, wherein the cross-section increasing portion is configured of at least two cross-section increasing portions which are arranged to be spaced apart from each other in a circumferential direction of the balancer housing. ### Claim 16 (depends on 14) The washing machine according to claim 14, wherein the cross-section increasing portion is elongated in a circumferential direction of the balancer housing so as to accommodate at least two masses. ### Claim 17 (depends on 14) The washing machine according to claim 14, wherein the cross-section increasing portion is configured of at least two cross-section increasing portions which are symmetrically arranged on the basis of an imaginary line passing through a center of rotation of the drum. ### Claim 18 (depends on 14) The washing machine according to claim 14, wherein a cross-sectional area of both ends of the cross-section increasing portion is greater than that between both ends of the cross-section increasing portion such that at least one mass disposed at the cross-section increasing portion is decoupled from the cross-section increasing portion when an RPM of the drum departs from a specific RPM range. ### Claim 19 (depends on 14) The washing machine according to claim 14, wherein the mass has a spherical shape. ### Claim 20 (depends on 19) The washing machine according to claim 19, wherein the cross-section increasing portion has a shape corresponding to at least a portion of the mass. ### Claim 21 A balancer of a washing machine to offset an unbalanced load on a drum of the washing machine, comprising: a balancer housing which is mounted to at least one of a front surface and a rear surface of the drum and has a channel extending in a circumferential direction of the drum; a plurality of masses movably disposed along the channel; at least one groove which is formed on an inner surface of the balancer housing to seat the plural masses so as to restrict the masses moving along the channel when an RPM of the drum is lower than a specific RPM range; and a damping fluid accommodated in the channel such that the damping fluid applies resistance to the masses when force acts on the masses. ### Claim 22 (depends on 21) The balancer according to claim 21, wherein the groove is elongated in a circumferential direction of the balancer housing so as to accommodate at least two masses. ### Claim 23 (depends on 22) The balancer according to claim 22, wherein the groove comprises: first support portions provided at both ends thereof so as to support the masses in the circumferential and radial directions of the balancer housing; and a second support portion provided between the first support portions so as to support the masses in the radial direction of the balancer housing. ### Claim 24 (depends on 23) The balancer according to claim 23, wherein the second support portion protrudes inward of the channel. ### Claim 25 (depends on 24) The balancer according to claim 24, wherein the second support portion has a length between 1 mm and 3 mm which protrudes inward of the channel. ### Claim 26 A balancer to offset an unbalanced load in a rotating body, the balancer comprising: a housing having an annular channel therein, the housing being adapted to be attached to the rotating body; at least one mass movably disposed in the channel; and at least one groove formed on an inner surface of the balancer housing, the at least one groove being configured to restrict the mass moving along the channel when a rotation speed of the rotating body is within a predetermined range. ### Claim 27 (depends on 26) The balancer according to claim 26, wherein the groove comprises at least two grooves spaced apart from each other in a circumferential direction of the balancer housing. ### Claim 28 (depends on 26) The balancer according to claim 26, wherein both ends of the groove are provided with support portions to prevent the mass from being decoupled from the groove when the rotation speed of the rotating body is within the predetermined range. ### Claim 29 (depends on 26) The balancer according to claim 26, wherein the groove comprises at least one flat surface, and a first inclined surface and a second inclined surface connected at both ends of the flat surface.