Linear vibration motor

Patent metadata

Field	Value
Publication number	US-10819202-B2
Application number	US-201916445432-A
Country	US
Kind code	B2
Filing date	Jun 19, 2019
Priority date	Jul 11, 2018
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A linear vibration motor includes: a casing having an upper casing whose bottom is open and a lower casing coupled to the upper casing to form an internal space therein; a stator disposed on top of the lower casing in the internal space formed by the casing; an elastic member disposed around the stator in the internal space formed by the casing in such a manner as to allow one surface thereof to be coupled to the lower casing; an oscillator mounted on the other surface of the elastic member and having a ring-shaped magnet disposed around the stator; and a magnetic fluid applied to top of the ring-shaped magnet, wherein the upper casing includes a ring-shaped protrusion formed on the inner surface facing the lower casing, and an inner diameter of the ring-shaped protrusion is greater than an outer diameter of the ring-shaped magnet.

First claim

What is claimed is:

1. A linear vibration motor comprising:
a casing ( 20 ) having an upper casing ( 20 a ) whose bottom is open and a lower casing ( 20 b ) coupled to the upper casing ( 20 a ) to form an internal space therein;
a stator ( 30 ) disposed on top of the lower casing ( 20 b ) in the internal space formed by the casing ( 20 );
an elastic member ( 40 ) disposed around the stator ( 30 ) in the internal space formed by the casing ( 20 ) in such a manner as to allow one surface thereof to be coupled to the lower casing ( 20 b );
an oscillator ( 50 ) mounted on the other surface of the elastic member ( 40 ) and having a ring-shaped magnet ( 52 ) disposed around the stator ( 30 ); and
a magnetic fluid (F) applied to top of the ring-shaped magnet ( 52 ),
wherein the upper casing ( 20 a ) comprises a ring-shaped protrusion ( 25 ) formed on the inner surface facing the lower casing ( 20 b ), and an inner diameter of the ring-shaped protrusion ( 25 ) is greater than an outer diameter of the ring-shaped magnet ( 52 ).

2. The linear vibration motor according to claim 1 , wherein the ring-shaped protrusion ( 25 ) has the same shape as the ring-shaped magnet ( 52 ).

3. The linear vibration motor according to claim 1 , wherein the oscillator ( 50 ) comprises:
a ring-shaped weight ( 54 ) disposed around the ring-shaped magnet ( 52 ); and
a ring-shaped yoke ( 56 ) disposed between the ring-shaped magnet ( 52 ) and the ring-shaped weight ( 54 ), and
the inner diameter of the ring-shaped protrusion ( 25 ) is greater than an outer diameter of the ring-shaped yoke ( 56 ).

4. The linear vibration motor according to claim 1 , wherein the ring-shaped protrusion ( 25 ) is a ring-shaped protruding member (R) attached to the inner surface of the upper casing ( 20 a ) facing the lower casing ( 20 b ).

5. The linear vibration motor according to claim 4 , wherein the ring-shaped protruding member (R) is made of a softer or harder material than the upper casing ( 20 a ).

6. The linear vibration motor according to claim 1 , wherein the ring-shaped protrusion ( 25 ) is a ring-shaped groove (H) concave downward from the outer surface of the upper casing ( 20 a ).

7. The linear vibration motor according to claim 1 , wherein the upper casing ( 20 a ) further comprises a buffer ( 60 ) disposed on the inner surface facing the lower casing ( 20 b ), and a diameter of the buffer ( 60 ) is greater than or equal to an inner diameter of the ring-shaped magnet ( 52 ) and less than or equal to the inner diameter of the ring-shaped protrusions ( 25 ).

8. The linear vibration motor according to claim 7 , wherein the buffer ( 60 ) is a flat plate buffering member (P) attached to the inner surface of the upper casing ( 20 a ) facing the lower casing ( 20 b ).

9. The linear vibration motor according to claim 8 , wherein the flat plate buffering member (P) is made of a softer or harder material than the upper casing ( 20 a ).

10. The linear vibration motor according to claim 7 , wherein the buffer ( 60 ) is a flat plate groove (H′) concave downward from the outer surface of the upper casing ( 20 a ).

Assignees

• Mplus Co Ltd

Inventors

• Chung Seuk Hwan

Classifications

• H04R9/06

  Loudspeakers · CPC title

• H02K33/04 Primary

  wherein the frequency of operation is determined by the frequency of uninterrupted AC energisation · CPC title

• H02K33/18 Primary

  with coil systems moving upon intermittent or reversed energisation thereof by interaction with a fixed field system, e.g. permanent magnets · CPC title

• H02K5/24

  specially adapted for suppression or reduction of noise or vibrations · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title