There is provided electromagnetic actuator. The electromagnetic actuator comprises a mover, a tubular coil and a tubular coil holder. The mover has a magnet. The tubular coil holder holds the tubular coil. The tubular coil holder has a cylindrical inner space for receiving the mover. The tubular coil and the magnet are configured to cooperate with each other to generate a force to move the mover relative to the coil holder along an axial axis. The mover comprises a ferromagnetic element arranged to change an inductance of the tubular coil in dependency on a position of the mover relative to the tubular coil holder. Further, there is provided a valve for opening and closing a conduit. The valve comprises the electromagnetic actuator.
There is provided electromagnetic actuator. The electromagnetic actuator comprises a mover, a tubular coil and a tubular coil holder. The mover has a magnet. The tubular coil holder holds the tubular coil. The tubular coil holder has a cylindrical inner space for receiving the mover. The tubular coil and the magnet are configured to cooperate with each other to generate a force to move the mover relative to the coil holder along an axial axis. The mover comprises a ferromagnetic element arranged to change an inductance of the tubular coil in dependency on a position of the mover relative to the tubular coil holder. Further, there is provided a valve for opening and closing a conduit. The valve comprises the electromagnetic actuator.
A coil assembly for a magnetic actuator is described, the coil assembly comprising: —a tubular coil holder (100) comprising a first (110) and second open distal end (120); —the first open distal end comprising an outer circular rim (112) and an inner circular rim (114) separated by a circular groove (116); —the second open distal end comprising an outer circular rim (122); the tubular coil holder further comprising a central circular rim (130) arranged substantially halfway between the inner circular rim of the first open distal end and the outer circular rim of the second open distal end; —a coil (140) formed of a single wire (150) the coil comprising a first coil section (142) arranged in a first winding area (144) between the inner circular rim of the first open distal end and the central circular rim, and a second coil section (146) in a second winding area (148) between the central circular rim and the outer circular rim of the second distal end; the first coil section and the second coil section being wound about the tubular coil holder in opposite directions; whereby a first end (152) and a second end (154) of the single wire are arranged in the circular groove, the inner circular rim comprising a longitudinal groove (114.1) to extend the first aid and the second end of the single wire from the circular groove to the first winding area; the central circular rim composing a longindinal groove (130.1) to extend the single wire form the first winding area to the second winding area and vice versa; —an external connection (160) comprising a first conductor (162) and a second conductor (164); whereby an end of the first conductor is electrically connected to the first end of the single wire so as to form a first electrical connection (166) arranged in the circular groove and an end of the second conductor is electrically connected to the second end of the single wire so as to form a second electrical connection (168) in the circular groove and wherein the first and second conductor extend through the outer circular rim via a longitudinal groove (112.1) of the outer circular rim.
A coil assembly for a magnetic actuator is described, the coil assembly comprising: - a tubular coil holder (100) comprising a first (110) and second open distal end (120); - the first open distal end comprising an outer circular rim (112) and an inner circular rim (114) separated by a circular groove (116); - the second open distal end comprising an outer circular rim (122); the tubular coil holder further comprising a central circular rim (130) arranged substantially halfway between the inner circular rim of the first open distal end and the outer circular rim of the second open distal end; - a coil (140) formed of a single wire (150), the coil comprising a first coil section (142) arranged in a first winding area (144) between the inner circular rim of the first open distal end and the central circular rim, and a second coil section (146) in a second winding area (148) between the central circular rim and the outer circular rim of the second distal end; the first coil section and the second coil section being wound about the tubular coil holder in opposite directions; whereby a first end (152) and a second end (154) of the single wire are arranged in the circular groove; the inner circular rim comprising a longitudinal groove (114.1) to extend the first end and the second end of the single wire from the circular groove to the first winding area; the central circular rim comprising a longitudinal groove (130.1) to extend the single wire form the first winding area to the second winding area and vice versa; - an external connection (160) comprising a first conductor (162) and a second conductor (164); whereby an end of the first conductor is electrically connected to the first end of the single wire so as to form a first electrical connection (166) arranged in the circular groove and an end of the second conductor is electrically connected to the second end of the single wire so as to form a second electrical connection (168) in the circular groove and wherein the first and second conductor extend through the outer circular rim via a longitudinal groove (112.1) of the outer circular rim.
An electromagnetic brake system is described, the system comprising: an AC generator having an AC output terminal, the AC generator being configured to be engaged with a mechanical driving unit and configured to generate an output voltage at the AC output terminal in response to a rotation of the mechanical driving unit; an external power resistor assembly having an input terminal and an output terminal, the input terminal of the external power resistor assembly being connected to the AC output terminal; a power electronics circuit that is configured to control a current supplied by the AC generator to the external power resistor assembly, the power electronics circuit having an input terminal connected to the output terminal of the external power resistor assembly, the power electronics circuit comprising a plurality of controllable electronic switches; a control unit having an input terminal configured to receive a load signal, the control unit further being configured to: ■ determine, based on the load signal, a required amplitude and phase angle of the current supplied by the AC generator, and ■ generate a control signal for controlling the plurality of controllable electronic switches of the electronic circuit, based on the required amplitude and phase angle, and provide the control signal to the plurality of electronic switches, so as to obtain the current having the required amplitude and phase angle.
H02P 3/22 - Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter for stopping or slowing an AC motor by short-circuit or resistive braking
H02P 6/16 - Circuit arrangements for detecting position
H02P 21/06 - Rotor flux based control involving the use of rotor position or rotor speed sensors
A63B 21/005 - Exercising apparatus for developing or strengthening the muscles or joints of the body by working against a counterforce, with or without measuring devices using electromagnetic or electric force-resisters
A speed sensor has a static part and a dynamic part arranged concentrically inside the static part. The static part has two permanent magnets and the dynamic part has two further permanent magnets. The magnet is oriented reversely to the further magnets. The magnets are tuned to each other so that gravity on the dynamic part is counteracted by the magnetic force on the dynamic part. As a result, the weight of the dynamic part need not be carried by springs and the dynamic part can move freely so that the full stroke can be used for measuring accelerations and the natural frequency is low. The static part further includes a measuring coil for measuring the displacement of the dynamic part and for the radial positioning of the dynamic part this part is connected to the static part by means of leaf springs.
G01P 3/48 - Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
A speed sensor 21 comprises a static part 3 and a dynamic part 5 arranged concentrically inside it. The static part 3 has two permanent magnets 7A and 7B and the dynamic part 5 has two iurther permanent magnets 9 and 11. The magnet 9 is oriented reversely to the iurther magnets 7A, 7B and 11. The magnets are tuned to each other so that gravity on the dynamic part is counteracted by the magnetic force on the dynamic part. As a result, the weight of the dynamic part need not be carried by springs and the dynamic part can move freely so that the full stroke can be used for measuring accelerations and the natural frequency is low. The static part 3 further includes a measuring coil 15 for measuring the displacement of the dynamic part and for the radial positioning of the dynamic part this part is connected to the static part 3 by means of leaf springs 17.
G01V 1/18 - Receiving elements, e.g. seismometer, geophone
G01P 15/11 - Measuring accelerationMeasuring decelerationMeasuring shock, i.e. sudden change of acceleration by making use of inertia forces with conversion into electric or magnetic values by magnetically sensitive devices by inductive pick-up
An actuator (1) has an annular magnet (3) displaceable in axial direction, with attached thereto on either one of the two sides annular, displaceable flux conductors (5). The actuator (1) further has two annular coils (7) surrounding the magnet at a distance with a gap (9) therebetween, and an annular, static flux conductor (11) surrounding the coils, which is in contact with the outside of the coils. The gap (9) accommodates an additional annular, static, ferritic flux conductor (13) whose outside surface is attached to the inside surface of the static flux conductor (11). The static flux conductor (11) is laminated with the layers resting on each other in radial direction.
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