Electromagnetic actuators capable of generating a symmetrical bidirectional force are disclosed. The electromagnetic actuators include a housing made of a ferromagnetic material and a shaft made of a magnetically inert material movable along an axis within the housing. In one type of actuator, captive permanent magnets are arranged on opposite interior end walls of the housing and an electromagnetic coil is mounted on a central portion of the shaft. The electromagnetic coil is capable of generating a force when energized that causes linear displacement of the shaft in either direction along its axis depending on the direction of current through the electromagnetic coil. In another type of actuator, captive electromagnetic coils are arranged on opposing inner end walls of the housing, and a permanent magnet is mounted on a central portion of the shaft. The electromagnetic coils are capable of generating a force when energized that causes linear displacement of the shaft in either direction along its axis depending on a direction of current through the electromagnetic coils.

A bi-stable solenoid device is proposed, comprising an armature, which is linearly movable between two opposite end stops and comprising a damping unit, which is in communication with the armature and which is configured to dampen and/or to prevent an impact of the armature on at least one of the end stops by a compression and/or an expansion of a gas volume.

A bi-stable solenoid device is proposed, comprising an armature, which is linearly movable between two opposite end stops and comprising a damping unit, which is in communication with the armature and which is configured to dampen and/or to prevent an impact of the armature on at least one of the end stops by a compression and/or an expansion of a gas volume.

Disclosed are a magnetic force control device for controlling a magnetic force on an interaction surface and a magnetic body holding device using the same. The magnetic force control device includes a first pole piece having a first interaction surface, a second pole piece having a second interaction surface, a stationary magnet fixed between the first pole piece and the second pole piece, a rotary magnet provided between the first pole piece and the second pole piece and configured to be rotatable to define a first arrangement state and a second arrangement state, and a coil wound around at least one of the first pole piece and the second pole piece, wherein the first arrangement state and the second arrangement state are switched by rotating the rotary magnet by controlling a current applied to the coil.

Disclosed are a magnetic force control device for controlling a magnetic force on an interaction surface and a magnetic body holding device using the same. The magnetic force control device includes a first pole piece having a first interaction surface, a second pole piece having a second interaction surface, a stationary magnet fixed between the first pole piece and the second pole piece, a rotary magnet provided between the first pole piece and the second pole piece and configured to be rotatable to define a first arrangement state and a second arrangement state, and a coil wound around at least one of the first pole piece and the second pole piece, wherein the first arrangement state and the second arrangement state are switched by rotating the rotary magnet by controlling a current applied to the coil.

A linear actuator includes a magnet housing having first and second planar sides, a front plate and a rear plate, and a base plate covering a channel defined by the magnet housing. A first plurality of magnets is secured to the first planar side and a second plurality of magnets is secured to the second planar side. A linear guide is slidably secured to an inner surface of the base plate. A piston assembly has a piston element attached to the linear guide. The piston assembly includes a shaft and a printed circuit board attached to the piston element. The printed circuit board defines a controller and a printed coil assembly. A flex cable is electrically connected to the printed circuit board. The piston assembly is disposed to move linearly during operation of the linear actuator.

A bistable relay and a bistable actuator are provided. The bistable actuator includes a magnetic latching mechanism and an electromagnet. The magnetic latching mechanism includes a rotation shaft, a pillar-shaped permanent magnet, a columnar hollow magnetic conductor and two shells, and operates between a first and second stable states. The columnar hollow magnetic conductor surrounds the pillar-shaped permanent magnet wrapping the rotation shaft, and maintains a gap with the pillar-shaped permanent magnet. The electromagnet is connected to the columnar hollow magnetic conductor for driving the pillar-shaped permanent magnet to rotate, so as to switch the magnetic latching mechanism to the stable state. During a process that the magnetic latching mechanism is switched to the stable state, the rotation shaft rotates synchronously along with the magnetic latching mechanism to drive an impact system to move relative to a contact system, so as to contact or disconnect the contact points.

A bistable relay and a bistable actuator are provided. The bistable actuator includes a magnetic latching mechanism and an electromagnet. The magnetic latching mechanism includes a rotation shaft, a pillar-shaped permanent magnet, a columnar hollow magnetic conductor and two shells, and operates between a first and second stable states. The columnar hollow magnetic conductor surrounds the pillar-shaped permanent magnet wrapping the rotation shaft, and maintains a gap with the pillar-shaped permanent magnet. The electromagnet is connected to the columnar hollow magnetic conductor for driving the pillar-shaped permanent magnet to rotate, so as to switch the magnetic latching mechanism to the stable state. During a process that the magnetic latching mechanism is switched to the stable state, the rotation shaft rotates synchronously along with the magnetic latching mechanism to drive an impact system to move relative to a contact system, so as to contact or disconnect the contact points.

The magnetic resistance of a magnetic path that passes through a coil (6) is increased by magnetically dividing a stator core into a plurality of divided cores (4, 5) in such a manner that the magnetic flux of a permanent magnet (7) flows through the magnetic path when a projection (82) of a plunger (8) magnetically connects the divided cores (4, 5), hence the magnetic resistance of the magnetic path that passes through the coil (6) rapidly changes due to a positional relationship between a gap between the divided cores (4, 5) and the plunger (8), and the magnetic flux that flows through the magnetic path rapidly changes, and moreover a large back electromotive force is produced.

The magnetic resistance of a magnetic path that passes through a coil (6) is increased by magnetically dividing a stator core into a plurality of divided cores (4, 5) in such a manner that the magnetic flux of a permanent magnet (7) flows through the magnetic path when a projection (82) of a plunger (8) magnetically connects the divided cores (4, 5), hence the magnetic resistance of the magnetic path that passes through the coil (6) rapidly changes due to a positional relationship between a gap between the divided cores (4, 5) and the plunger (8), and the magnetic flux that flows through the magnetic path rapidly changes, and moreover a large back electromotive force is produced.