US 12,149,888 B2
Balanced armature receiver and yoke therefor
Richard Scheleski, Naperville, IL (US); and Yahui Zhang, Schaumburg, IL (US)
Assigned to Knowles Electronics, LLC, Itasca, IL (US)
Filed by Knowles Electronics, LLC, Itasca, IL (US)
Filed on Sep. 2, 2022, as Appl. No. 17/902,791.
Prior Publication US 2024/0080627 A1, Mar. 7, 2024
Int. Cl. H04R 11/02 (2006.01); H04R 1/02 (2006.01); H04R 7/12 (2006.01)
CPC H04R 11/02 (2013.01) [H04R 1/025 (2013.01); H04R 7/12 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A balanced armature receiver yoke comprising:
a close-ended wall structure defining an armature passage through which a free-end portion of an armature is movably located between magnets retained in spaced apart relation within the passage when another portion of the armature is fastened to the close-ended wall structure, the close-ended wall structure comprising:
a plurality of wall portions;
a plurality of folded corner portions, a corresponding one of the plurality wall portions extending between and interconnecting neighboring folded corner portions;
a thickness of a radial dimension of the plurality of folded corner portions not less than a thickness of the plurality of wall portions,
wherein the close-ended wall structure is a magnetic-flux-carrying material,
wherein each of the plurality of wall portions are coined wall portions.
 
9. A balanced armature receiver motor comprising:
a magnetic-flux-carrying yoke comprising a plurality of folded corner portions interconnected by a plurality of wall portions defining a close-ended structure having an armature passage,
a thickness along a radial dimension of the plurality of folded corner portions not less than a thickness of the plurality of wall portions;
a first magnet located in the armature passage and fastened to a first wall portion of the plurality of wall portions, and a second magnet located in the armature passage and fastened to a second wall portion of the plurality of wall portions opposite the first wall portion of the plurality of wall portions;
an armature having a first portion fastened to the yoke, the armature having a second portion movably located in the armature passage between the first and second magnets; and
an electrical coil assembly electromagnetically coupled to the armature,
wherein each of the plurality of wall portions are coined wall portions.
 
14. A balanced armature receiver comprising:
a housing having a sound port;
a diaphragm disposed in the housing and separating the housing into a back volume and a front volume acoustically coupled to the sound port;
a motor disposed in the housing and comprising:
a magnetic-flux-carrying yoke comprising a plurality of folded corner portions interconnected by a plurality of wall portions defining a close-ended structure having an armature passage, a thickness of the plurality of wall portions less than a thickness of the plurality of folded corner portions;
a first magnet located in the armature passage and fastened to a first wall portion of the close-ended structure, and a second magnet located in the armature passage and fastened to a second wall portion, opposite the first wall portion, of the close-ended structure;
an armature having a first portion fastened to the yoke, the armature having a second portion movably located in the armature passage between the first and second magnets;
an electrical coil assembly electromagnetically coupled to the armature; and
a link connecting the armature to the diaphragm
the close-ended structure comprising a folded stamped-strip having end portions mated at a joint, and
wherein each of the plurality of wall portions are coined wall portions.