An actuator for controlling the movement of an element between two stable positions with pulsed electrical control without a change in polarity comprises: a ferromagnetic mobile mass, at least one electrically controlled wire coil that is fixed with respect to the mobile mass, at least two ferromagnetic poles that are fixed with respect to the mobile mass and on either side of the mobile mass. The actuator comprises at least one permanent magnet that attracts the mobile mass in order to achieve the two stable positions. The mobile mass defines, with the ferromagnetic poles, at least two variable air gaps during the movement of the mobile apparatus. The magnetic flux of the permanent magnet opposes the magnetic flux generated by the at least one coil regardless of the position of the mobile mass.

A mover is attracted and is moved in an axial direction with a predetermined stroke by a magnetic force generated between a stator and the mover when a coil is energized. The stator includes: a first stator positioned at a side where a stroke start position of the mover is located, and a second stator positioned at another side where a stroke end position of the mover is located. The mover includes a tapered portion which has a diameter progressively reduced toward the second stator, and a small-diameter cylindrical portion which is shaped in a straight form and has a constant outer diameter along an entire axial extent of the small-diameter cylindrical portion. An outer wall of the small diameter cylindrical portion has the outer diameter that is equal to an outer diameter of a smallest-diameter part of the tapered portion.

The present invention provides a permanent magnet-electromagnet synergistic coupling-based high-speed solenoid valve with a high dynamic response and a low rebound, including a shell and an iron core. The iron core is installed in the shell, an axial center through hole is formed in a middle of the iron core, a spring limiting sleeve is installed in the axial center through hole, an armature and a reset spring cavity are sequentially formed below the iron core, an upper portion of a valve rod is located in the spring limiting sleeve, an upper disc permanent magnet, a lower disc permanent magnet and a spring washer are arranged in the spring limiting sleeve, and a giant magnetostrictor is installed between the upper disc permanent magnet and the lower disc permanent magnet. By means of the present invention, electromagnetic force generated during pickup of the armature can be effectively improved.

A drive unit for a gate valve controls a flow rate of fluid passing through an opening in a valve seat by forward and backward moving a valve plate against the opening in the valve seat. This drive unit includes a shaft connected to the valve plate, a linear motor for driving the shaft and drive control means to control the drive of the linear motor. The linear motor has a plurality of coils for generating a magnetic field by electric current and a permanent magnet assembly to react to the magnetic field generated by the plurality of coils. The plurality of coils forms a stator while the permanent magnet assembly is connected to the shaft and displaced together with the shaft to form a mover to forward and backward move the valve plate. Each of the plurality of coils is connected to its own control circuit and the drive control means individually controls the current flowing through each of the plurality of coils via the control circuit. The drive control means may be provided with a linear encoder to detect the current position of the permanent magnet assembly.

An actuator for controlling the movement of an element between two stable positions with pulsed electrical control without a change in polarity comprises: a ferromagnetic mobile mass, at least one electrically controlled wire coil that is fixed with respect to the mobile mass, at least two ferromagnetic poles that are fixed with respect to the mobile mass and on either side of the mobile mass. The actuator comprises at least one permanent magnet that attracts the mobile mass in order to achieve the two stable positions. The mobile mass defines, with the ferromagnetic poles, at least two variable air gaps during the movement of the mobile apparatus. The magnetic flux of the permanent magnet opposes the magnetic flux generated by the at least one coil regardless of the position of the mobile mass.

An automatic leveling device of a 3D printer, and a 3D printer is provided. The automatic leveling device includes a photoelectric switch, an electromagnetic assembly and a probe assembly. The photoelectric switch is arranged in a housing and defines a photosensitive groove. The electromagnetic assembly is arranged in the housing and defines a sliding hole. The probe assembly is slidably engaged in the sliding hole, and an end of the probe assembly is engaged in the photosensitive groove. The electromagnetic assembly is capable of driving the probe assembly to make the end of the probe assembly move out of the photosensitive groove. The automatic leveling device has the advantages of simple structure, low manufacturing difficulty, low production cost, simple and stable leveling mode, high detection repetition accuracy and no complex circuit and software cooperation.

Presented are a single coil apparatus and a method of forming. An exemplary apparatus includes solenoid assembly. The solenoid assembly includes a core tube extending along a longitudinal axis. The solenoid assembly further includes a first magnet and a second magnet located outside the core tube, the first magnet spaced along the longitudinal axis from the second magnet, and an excitation coil disposed radially outward of the first magnet and the second magnet.

The present invention provides a magnetic movement path control device including: a magnetic force moving unit including a permanent magnet generating a permanent magnetic force, a first pole piece attached to a first surface of the permanent magnet, and a second pole piece attached to a second surface of the permanent magnet; a first outer pole piece in contact with the magnetic force moving unit to form a magnetic path; a second outer pole piece in contact with the magnetic force moving unit to form a magnetic path different from the magnetic path formed by the first outer pole piece; and a magnetic path control member releasing or generating the magnetic path by allowing the magnetic force moving unit to come into contact with the first outer pole piece and be spaced apart from or come in contact with the second outer pole piece, wherein the magnetic force moving unit moves between a first position where at least one of the first pole piece and the second pole piece is in contact with the first outer pole piece and the second pole piece is spaced apart from the second outer pole piece to drop a target object and a second position where at least one of the first pole piece and the second pole piece is in contact with the first outer pole piece and the second pole piece is in contact with the second outer pole piece to lift the target object.

Disclosed are a solenoid actuator and a multi-stage solenoid actuator for transmitting a constant force. The solenoid actuator includes a tubular solenoid, a power unit capable of applying current to the solenoid, and a magnetic pair member having two magnetic members providing magnetic fields formed such that respective first poles thereof face each other and respective second poles thereof different from the first poles are located at both distal ends, and extending through the tub of the solenoid. The multi-stage solenoid actuator includes a solenoid assembly where at least two tubular solenoids are regularly aligned such that inner spaces of the tubes of the solenoids are arranged in series, a power unit capable of individually applying current to each solenoid of the solenoid assembly, at least one magnetic pair moveable unit having two magnetic members providing magnetic fields formed such that respective first poles thereof face each other and respective second poles thereof different from the first poles are located at both distal ends, and extending through the tub of the solenoid assembly, and a controller for determining and controlling a solenoid to receive the current from the power unit depending on a position of the magnetic pair moveable unit.

A system may include an armature configured to move between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The system may also include a coil configured receive a current, such that the current conducting in the coil is configured to magnetize a core. The magnetized core may cause the armature to move from the first position to the second position. The system may also include a control system configured to detect a position of the armature based on an inductance of the coil.