EP-4738670-A1 - LINEAR ACTUATOR AND HAIR CUTTING DEVICE

EP4738670A1EP 4738670 A1EP4738670 A1EP 4738670A1EP-4738670-A1

Abstract

The invention relates to the field of linear motor technologies, and specifically provides a linear actuator. The linear actuator includes: at least one electromagnet (100) arranged horizontally and magnet groups (300) disposed at two sides of the electromagnet separately. Each electromagnet includes two magnetic poles, and the two magnetic poles are arranged at two ends of the electromagnet along an axial direction thereof. Each magnet group is opposite to the magnetic poles on sides of the electromagnet correspondingly, each magnet group includes at least two magnets (320), a side of a part of the magnets facing the electromagnet is S pole, and a side of another part of the magnets facing the electromagnet is N pole. After energizing the electromagnet, the magnet groups are driven to reciprocate along a direction perpendicular to a central axis of the electromagnet through magnetic induction action between the electromagnet and the magnet groups. A volume of the linear actuator can be reduced by the above structure.

Inventors

WONG, YING MAN JOHN
Wong, Yin Wai
POLLOCK, CHARLES
POLLOCK, HELEN
Dorton, Tom

Assignees

Raymond (Panyu Nansha) Electrical Appliances Development Co., Ltd.
Technelec Ltd.

Dates

Publication Date: 20260506
Application Date: 20250310

Claims (10)

A linear actuator, comprising: at least one electromagnet arranged horizontally, wherein each electromagnet comprises two magnetic poles, and the two magnetic poles are arranged at two ends of the electromagnet along an axial direction of the electromagnet; and magnet groups disposed at two sides of the at least one electromagnet separately, wherein each magnet group is opposite to a corresponding one of the magnetic poles of the at least one electromagnet, each magnet group comprises at least two magnets, a side of a part of the at least two magnets facing the at least one electromagnet is S pole, and a side of another part of the at least two magnets facing the at least one electromagnet is N pole; after energizing the at least one electromagnet, the magnet groups are driven to reciprocate along a direction perpendicular to a central axis of the at least one electromagnet through magnetic induction action between the at least one electromagnet and the magnet groups.
The linear actuator as claimed in claim 1, wherein a number of the at least two magnets of each magnet group is one more than a number of the at least one electromagnet.
The linear actuator as claimed in any one of claims 1-2, wherein a number of the at least one electromagnet is two, the two electromagnets are juxtaposed with each other, after electrified, polarities of magnetic poles at same ends of the two electromagnets are opposite, a number of the at least two magnets is three, and polarities of the three magnets facing the two electromagnets alternate between S pole and N pole; or a number of the at least one electromagnet is two, the two electromagnets are juxtaposed with each other, after electrified, polarities of magnetic poles at same ends of the two electromagnets are same, a number of the at least two magnets is three, and polarities of the three magnets facing the two electromagnets are arranged in units of S-pole-S-pole-N-pole, N-pole-S-pole-S-pole, S-pole-N-pole-N-pole, or N-pole-N-pole-S-pole.
The linear actuator as claimed in claim 2, wherein vertical lines perpendicular to surface centers of the at least two magnets and the central axis of the at least one electromagnet are arranged in a staggered manner, and the central axis of the at least one electromagnet is located between the vertical lines perpendicular to the surface centers of adjacent two of the at least two magnets.
The linear actuator as claimed in any one of claims 1-4, wherein a magnetic pole arrangement on the side of the at least two magnets in one of the magnet groups facing the at least one electromagnet is same as a magnetic pole arrangement on the side of the at least two magnets in another one of the magnet groups facing the at least one electromagnet; or a magnetic pole arrangement on the side of the at least two magnets in one of the magnet groups facing the at least one electromagnet is opposite to a magnetic pole arrangement on the side of the at least two magnets in another one of the magnet groups facing the at least one electromagnet.
The linear actuator as claimed in claim 1, wherein the at least one electromagnet comprises a metal core and an insulator wrapped around the metal core, with a coil wound around the insulator, the metal core comprises a plurality of metal sheets, and the plurality of metal sheets are stacked to form the metal core.
The linear actuator as claimed in claim 1, further comprising: an installation frame; wherein the installation frame comprises an electromagnet installation part and magnet group installation parts disposed on two sides of the electromagnet installation part, the at least one electromagnet is horizontally disposed in the electromagnet installation part, the magnet groups are respectively disposed in the magnet group installation parts, and after the magnet groups are installed in the magnet group installation parts, each of the magnet groups is opposite to the corresponding one of the magnetic poles of the at least one electromagnet installed in the electromagnet installation part.
The linear actuator as claimed in claim 7, wherein the magnet group installation parts are elastically connected to the electromagnet installation part via elastic connection parts, and the elastic connection parts are integrally formed with the electromagnet installation part into one whole or detachably connected to the electromagnet installation part via fasteners; or the magnet group installation parts are connected to actuating arms respectively, the actuating arms are provided with output shafts, the output shafts are disposed on the installation frame, and free ends of two of the actuating arms are arranged in a staggered manner or in an opposite manner.
The linear actuator as claimed in any one of claims 7-8, wherein two sides of the electromagnet installation part are provided with connecting walls respectively, the connecting walls are respectively provided with first extension parts, two sides of each of the magnet group installation parts are provided with second extension parts respectively, one of the first extension parts and one of the second extension parts on a same side as the one of the first extension parts extend in a same direction, and the one of the first extension parts and the one of the second extension parts on the same side as the one of the first extension parts are connected via the elastic connection part; and each elastic connection part comprises two first elastic support parts and a second elastic support part, the second elastic support part is disposed between the two first elastic support parts, and a thickness of the second elastic support part is greater than a thickness of each of the two first elastic support parts at two sides of the second elastic support part.
A hair cutting device, comprising: a housing and movable blade assemblies; wherein an inside of the housing is provided with the linear actuator as claimed in any one of claims 1-9, the movable blade assemblies are connected to the magnet group installation parts, and the movable blade assemblies reciprocate with the magnet groups under power provided by the magnet groups of the linear actuator.

Description

TECHNICAL FIELD The invention relates to the field of linear motor technologies, and more particularly to a linear actuator and a hair cutting device equipped with the linear actuator. BACKGROUND A linear actuator is a device used to control linear displacement or force. The linear actuator generates a magnetic field through the principle of electromagnetic induction and uses the magnetic field to apply force or motion to a load, thereby achieving linear control of the load. The linear actuator in the related art includes a stator assembly and a mover assembly. The mover assembly drives the load to perform linear reciprocating motion through the magnetic induction action between the stator assembly and the mover assembly. Specifically, in the stator assembly, a core of an electromagnet usually adopts an E-shaped core with coils set on a middle arm of the E-shaped core. By energizing the linear actuator, the E-shaped core becomes electrified and magnetized. The magnetized E-shaped core has magnetism and can produce repulsive or attractive forces with the magnet in the mover assembly, causing the load connected to the mover assembly to perform linear reciprocating motion. To ensure that the load moves smoothly in the linear reciprocating motion, it is necessary to ensure that the core in the stator assembly and the magnet in the mover assembly continuously alternate between attraction and repulsion. When it is necessary to drive two loads in opposite directions at the same time, two magnets are required to be independently set, and the electromagnet drives both the two magnets to move linearly, with the motion directions of the two magnets being opposite. However, it is not suitable to use two electromagnets to independently drive the magnets, due to a large size of the E-shaped core itself. If only one E-shaped core is used to make the electromagnet, it must be considered whether the magnetic flux generated by the electromagnet can pass through the two magnets at the same time to ensure that the two magnets continue to move in a linear reciprocating motion. Therefore, in the industry, under the premise of avoiding the use of two E-shaped cores, the size of the E-shaped core relative to the magnet is appropriately increased to ensure that the two magnets can be driven smoothly in reciprocating motion while appropriately reducing the volume. However, for this field, this still cannot effectively reduce the volume of the linear actuator, causing the equipment or device using the linear actuator to need to provide a larger installation space, which in turn increases the volume and size of the equipment or device using the linear actuator. SUMMARY The invention aims at solving technical problems in the related art and provides a linear actuator and a hair cutting device provided with the linear actuator. In order to solve above problems, the invention provides the following technical solutions. The linear actuator includes at least one electromagnet arranged horizontally, each electromagnet includes two magnetic poles, and the two magnetic poles are arranged at two ends of the electromagnet along an axial direction of the electromagnet. Magnet groups are disposed at two sides of the at least one electromagnet separately. Each magnet group is opposite to a corresponding magnetic pole of the at least one electromagnet, each magnet group includes at least two magnets, a side of a part of the at least two magnets facing the at least one electromagnet is S pole, and a side of another part of the at least two magnets facing the at least one electromagnet is N pole. After energizing the at least one electromagnet, the magnet groups are driven to reciprocate along a direction perpendicular to a central axis of the at least one electromagnet through magnetic induction action between the at least one electromagnet and the magnet groups. In the linear actuator of the invention, the at least one electromagnet is arranged horizontally, with the two magnetic poles of the electromagnet along the axial direction of the electromagnet at the two ends of the electromagnet, and each magnetic pole of the at least one electromagnet is provided with a corresponding magnet group. When the at least one electromagnet is powered by alternating current, the magnetic induction action between the at least one electromagnet and the magnet groups can be utilized to cause the magnet groups to reciprocate along a direction perpendicular to the axis of the electromagnet. By arranging the at least one electromagnet horizontally and arranging the magnet groups at the sides of the at least one electromagnet opposite to the magnetic poles of the at least one electromagnet, making the at least one electromagnet disposed between two sets of the magnet groups, the magnetic fields generated at the two ends of the at least one electromagnet can respectively drive the magnet groups. This arrangement fully utilizes the magnetic poles of the at least one elec