TWI846939B - Shaftless linear resonant actuator - Google Patents

Abstract

A non-axis linear resonant actuator includes a magnet element, a pair of counter weights, a pair of springs and a housing. The magnet element is sandwiched between the pair of counter weights, and the counter weight is further clamped between the pair of springs. The magnet element, the counterweight, and the pair of springs are arranged in the housing, the magnet element and the pair of counterweights are not provided with a central axis in the axial direction, but are fixed together by adhesive bonding. The non-axis linear vibration motor of the invention has simple structure, convenient assembly and low manufacturing cost.

Description

Shaftless linear vibration motor

The present invention relates to a linear vibration motor, in particular to a shaftless linear vibration motor with a simple structure and stable and reliable operation.

The linear vibration motor shown in U.S. Publication No. US20130169071A1 is widely used in cellular phones. However, its structure is complicated and the assembly is complicated.

Therefore, it is necessary to provide a shaftless linear vibration motor with a simple structure and easy assembly to overcome the above defects.

The technical problem to be solved by the present invention is to provide a shaftless linear vibration motor with a simple structure and the characteristics of stable and reliable operation.

To solve the above problems, the present invention can adopt the following technical solutions: a shaftless linear vibration motor, the linear vibration motor includes a metal shell with a containing space, a magnetic element arranged in the containing space, a pair of counterweights axially sandwiching the magnetic element, a pair of springs axially sandwiching a pair of counterweights and the magnetic element, the shell is provided with a first holding device for holding the corresponding outer ends of the springs, the counterweights are provided with a second holding device for holding the corresponding inner ends of the springs, the magnetic element and the counterweights are fixed by glue without a longitudinally extending central axis.

Furthermore, the mating surface between the counterweight block and the magnetic element is recessed to form a blind hole, and the blind hole is used to accommodate as much glue as possible.

Furthermore, the first retaining device on the metal housing includes a pair of tabs punched out from the metal housing.

Furthermore, a pair of tabs are torn inward from the end wall of the metal housing and an opening is formed at the torn portion, and the axisless linear vibration motor also includes a cover attached to the end wall to cover the opening.

Furthermore, a pair of the protrusions are spaced apart in a transverse direction perpendicular to the axis.

Furthermore, a pair of said springs have a rectangular cross-section.

Furthermore, the spring has a rectangular cross-section, and the second retaining device is a rectangular protrusion formed on the other end of the counterweight relative to the mating surface.

Furthermore, the metal shell includes an upper cover having a pair of long walls and a lower cover having a pair of end walls.

Furthermore, the axisless linear vibration motor also includes a coil element, which has a coil held in the accommodation space of the metal shell and a flexible cable extending out of the metal shell.

Furthermore, the magnetic element includes at least one pair of magnets and a yoke axially sandwiched between adjacent magnets, and the coil surrounds the magnetic element and forms a gap between the coil and the magnetic element.

Compared with the prior art, the magnet element of the axisless linear vibration motor of the present invention and a pair of counterweight blocks are fixed together by adhesive bonding without a central axis in the axial direction. The axisless linear vibration motor of the present invention has a simple structure, convenient assembly and low manufacturing cost.

200: Shaftless linear vibration motor

285:Magnetic element

240: First magnet

242: Second magnet

260: yoke

230/232: Counterweight

231/233: Blind hole

235: protrusion

225: Tabs

250/252: Spring

275: Linear components

270: Conductive coil

280: Flexible cable

210: First shell

212: Upper cover

214: Long Wall

220: Second shell

222: Lower cover

224: End wall

225: Tabs

223: Open mouth

227/228: Cover

The first figure is a three-dimensional diagram of the axisless linear vibration motor of the present invention.

The second picture is a three-dimensional picture from another angle of the first picture.

The third figure is an exploded view of the shaftless linear vibration motor in the first figure.

The fourth figure is another exploded view of the shaftless linear vibration motor in the first figure.

The fifth picture is an exploded view of the fourth picture from another angle.

The sixth figure is another exploded view of the shaftless linear vibration motor in the first figure.

The seventh picture is an exploded view of the sixth picture from another angle.

Figure 8 is a cross-sectional view of Figure 1 along line VIII-VIII.

Figure 9 is a cross-sectional view of Figure 1 along line IX-IX.

Referring to the first to ninth figures, the axisless linear vibration motor 200 of the present invention includes a metal housing with an internal accommodation space, a magnetic element 285 disposed in the accommodation space, a pair of counterweights 230, 232, a pair of springs 250, 252 and a coil assembly 275. The pair of counterweights 230, 232 sandwich the magnetic element 285 axially (i.e., longitudinally), and the pair of springs 250, 252 sandwich the pair of counterweights 230, 232 and the magnetic element 285 axially.

The metal housing comprises a first housing 210 and a second housing 220 which are fixed together to form a receiving space. The first housing 210 comprises a horizontal plate-shaped upper cover 212 and a pair of long walls 214 extending from the upper cover. The second housing 220 comprises a horizontal plate-shaped lower cover 222 and a pair of end walls 224 extending from the lower cover. Each of the end walls 224 is formed with a first retaining device extending inwardly for retaining the spring. The first retaining device is preferably a pair of tabs 225 torn from the end wall 224. The pair of tabs 225 are arranged at intervals in a transverse direction perpendicular to the axial direction. The pair of tabs 225 are used to retain the springs 250 and 252. A pair of tabs 225 form an opening 223 from the tear of the end wall 224, and a pair of thin plate-shaped covers 227 and 228 are respectively attached to the corresponding end wall 224 to cover the opening 223. It should be noted that the first retaining device can also be a convex block (not shown) protruding inward from the end wall 224 without an opening, and the convex block (not shown) is preferably rectangular.

The magnetic element 285 includes at least one pair of magnets and a yoke axially clamped between the pair of magnets. In the present invention, the magnet assembly 285 includes a first magnet 240, a second magnet 242 and a yoke 260 axially clamped between the first magnet 240 and the second magnet 242. The yoke 260 is a soft magnetic material with high magnetic permeability and low toughness compared with the first magnet 240 and the second magnet 242. The counterweight block 230 is recessed on the mating surface with the magnetic element 285 to form a blind hole 231, and at least two blind holes 231 are provided. The counterweight block 232 is recessed on the mating surface with the magnetic element 285 to form a blind hole 233, and at least two blind holes 233 are also provided. The blind hole on each counterweight block is a rectangular hole, a circular hole, or a combination of a rectangular hole and a circular hole.

The counterweight blocks 230, 232 are provided with a second retaining device for retaining the springs 250, 252 respectively. The second retaining device is a protrusion 235 extending axially from the other end of the counterweight blocks 230, 232 relative to the matching surface. The protrusion 235 is roughly rectangular in structure. The springs 250, 252 have a rectangular cross-section. In this way, the rectangular springs 250, 252 can be reliably limited by the rectangular protrusions 235 of the counterweight blocks 230, 232. In general, one end of the spring 250 is limited by the protrusion 235 of the counterweight 230, and the other end of the spring 250 is limited by a pair of tabs 225 of the end wall 224. One end of the spring 252 is limited by the protrusion 235 of the counterweight 232, and the other end of the spring 252 is limited by a pair of tabs 225 of the other end wall 224. The coil element 275 includes a conductive coil 270 retained in the accommodating space of the metal shell and a flexible cable 280 extending out of the metal shell, and the flexible cable 280 is a flexible printed circuit. The conductive coil 270 surrounds the magnetic element 285 and there is a gap between the conductive coil 270 and the magnetic element 285, and the flexible cable 280 extends out of the metal shell for power supply.

The counterweight block 230 and the first magnet 240 are fixed by glue, and the counterweight block 232 and the second magnet 242 are fixed by glue. The blind holes 233 of the counterweight block 230 and the counterweight block 232 can accommodate as much of the glue as possible, so that the counterweight blocks 230, 232 and the first and second magnets 240, 242 are reliably adhered. In addition, the blind hole can also be provided between the interface between the first and second magnets 240, 242 of the magnetic element 285 and the yoke 260 as needed, so as to accommodate more glue to keep them reliably fixed to each other.

Compared with the prior art, since there is no central axis (not shown) extending through the corresponding magnet element 285 and the counterweight block 230, 232, the manufacturing of the magnet element 285 and the counterweight block 230, 232 is simplified without considering the precise size of the hole therein. In the present invention, the magnet element is not provided with a hole, and although the counterweight block is provided with a blind hole, it is not necessary to ensure the high accuracy of the hole.

It is understandable that when the coil element 275 is operated, the magnetic element 285 together with a pair of counterweights 230, 232 will vibrate axially between the pair of springs 250, 252, thereby generating tactile vibration. It is worth noting that because the present invention does not have a central axis (not shown), the combination of the magnetic element 285 and a pair of counterweights 230, 232 further generates tactile vibration in the vertical direction.

It should be pointed out that the above is only the best implementation method of the present invention, not all implementation methods. Any equivalent changes made to the technical solution of the present invention by ordinary technicians in this field after reading the specification of the present invention are covered by the claims of the present invention.

200: Shaftless linear vibration motor

225: Tabs

230/232: Counterweight

231/233: Blind hole

235: protrusion

240: First magnet

242: Second magnet

250/252: Spring

260: yoke

270: Conductive coil

280: Flexible cable

Claims (8)

A shaftless linear vibration motor, characterized in that: the linear vibration motor comprises a metal housing with a containing space, a magnetic element arranged in the containing space, a pair of counterweight blocks sandwiching the magnetic element in the axial direction, a pair of springs sandwiching the pair of counterweight blocks and the magnetic element in the axial direction, the metal housing is provided with a first holding device for holding the corresponding outer ends of the springs, the counterweight blocks are provided with a first holding device for holding the corresponding outer ends of the springs, The magnet element and the counterweight block are fixed by adhesive bonding without a longitudinally extending central axis. The first retaining device on the metal shell includes a pair of tabs torn from the metal shell, and the pair of tabs are torn inward from the end wall of the metal shell and form an opening at the tearing position. The axisless linear vibration motor also includes a cover attached to the end wall to cover the opening. As described in claim 1, the axisless linear vibration motor, wherein the mating surface of the counterweight block and the magnetic element is recessed to form a blind hole, and the blind hole is used to accommodate as much of the glue as possible. The axisless linear vibration motor as described in claim 1, wherein a pair of the protrusions are spaced apart in a transverse direction perpendicular to the axis. The axisless linear vibration motor as described in claim 1, wherein one pair of the springs has a rectangular cross-section. The axisless linear vibration motor as described in claim 2, wherein the spring has a rectangular cross-section, and the second retaining device is a rectangular protrusion formed on the other end of the counterweight relative to the mating surface. The axisless linear vibration motor as described in claim 1, wherein the metal housing includes an upper cover having a pair of long walls and a lower cover having a pair of end walls. The axisless linear vibration motor as described in claim 1, wherein the axisless linear vibration motor further includes a coil element, the coil element having a coil held in the receiving space of the metal shell and a flexible cable extending out of the metal shell. The axisless linear vibration motor as described in claim 7, wherein the magnetic element includes at least one pair of magnets and a yoke axially sandwiched between adjacent magnets, and the coil surrounds the magnetic element and forms a gap between the magnetic element.

Images