To provide a solenoid configured so that vibration and noise in energization can be reduced.

A solenoid 1 is configured to use magnetic action in energization of a coil 2 to drive, in an axial direction, a core 4 at least including a first magnetic resistor. The solenoid 1 includes a shaft 5 attached to the core 4, and bearings 6, 7 supporting both end portions of the core. The solenoid 1 further includes a second magnetic resistor 4b configured to generate force for moving at least the core 4 in a radial direction by the magnetic action.

Electromagnetic actuators are provided, which generate bidirectional linear force output without magnetic bias from current or permanent magnets. Systems and methods based on the electromagnetic actuators are also provided. In particular, an electromagnetic actuator having a shaft, an axial bearing, coil assembly, top and bottom stationary flux returns, and top and bottom magnetic flux sensors to measure flux crossing the respective top and bottom axial air gaps.

A bi-stable solenoid includes a housing, a wire coil, a permanent magnet, an armature, a pin, and a spring. The wire coil is arranged within the housing. The armature is slidably arranged within the housing and is moveable between a first armature position and a second armature position. The pin at least partially extends out of the housing and is slidably engaged by the armature. The spring is biased between the armature and the pin. When the pin encounters an intermediate position between a retracted position and an extended position due to the pin engaging an obstruction, the spring is configured to maintain a biasing force on the pin until the obstruction is removed.

A bi-stable solenoid includes a housing, a wire coil, a permanent magnet, an armature, a pin, and a spring. The wire coil is arranged within the housing. The armature is slidably arranged within the housing and is moveable between a first armature position and a second armature position. The pin at least partially extends out of the housing and is slidably engaged by the armature. The spring is biased between the armature and the pin. When the pin encounters an intermediate position between a retracted position and an extended position due to the pin engaging an obstruction, the spring is configured to maintain a biasing force on the pin until the obstruction is removed.

A locking unit with a hydraulically actuable piston, an electromagnet with a coil and an armature, at least one latching element, a coupling rod, and a magnetic element. The coupling rod connects the magnetic element to the armature or an armature rod which is attached thereto, and a prestressing element fixes the magnetic element in a guide tube radially. As a result, an advantageous position determination is made possible by way of sensing of a magnetic field which is generated by the magnetic element.

A central actuator for a magnet valve of a cam phaser, the central actuator including a housing that envelops the central actuator; a pole tube and a pole core that are arranged within at least one coil that generates a magnetic field; an actuation plunger that is arranged at an armature that is axially movable in a direction in an armature cavity; a closure element that closes the armature cavity, wherein the closure element includes at least one pole core insert that includes a central bore hole and a support bushing that is arranged in the central bore hole of the pole core insert, wherein the actuation plunger is supported axially movable in the support bushing, and wherein the closure element includes a closure cover and is provided as a pre-assembled module.

A central actuator for a magnet valve of a cam phaser, the central actuator including a housing that envelops the central actuator; a pole tube and a pole core that are arranged within at least one coil that generates a magnetic field; an actuation plunger that is arranged at an armature that is axially movable in a direction in an armature cavity; a closure element that closes the armature cavity, wherein the closure element includes at least one pole core insert that includes a central bore hole and a support bushing that is arranged in the central bore hole of the pole core insert, wherein the actuation plunger is supported axially movable in the support bushing, and wherein the closure element includes a closure cover and is provided as a pre-assembled module.

An electromagnetic drive device includes a through-hole, through which a rod is received, and the rod includes an outer wall surface that is slidable relative to the through-hole. A clearance, which is measured from the outer wall surface of the rod placed in a maximum projected position to an inner wall surface of the through-hole, is smaller than a clearance, which is measured from the outer wall surface of the rod placed in a maximum retracted position to the inner wall surface. Therefore, a retracting-time clearance becomes relatively large, and thereby a frictional force between the rod and a support tubular portion can be reduced. Furthermore, a projecting-time clearance becomes relatively small, and thereby the amount of swing of a distal end of the rod in a radial direction can be reduced.

An electromagnetic drive device includes a through-hole, through which a rod is received, and the rod includes an outer wall surface that is slidable relative to the through-hole. A clearance, which is measured from the outer wall surface of the rod placed in a maximum projected position to an inner wall surface of the through-hole, is smaller than a clearance, which is measured from the outer wall surface of the rod placed in a maximum retracted position to the inner wall surface. Therefore, a retracting-time clearance becomes relatively large, and thereby a frictional force between the rod and a support tubular portion can be reduced. Furthermore, a projecting-time clearance becomes relatively small, and thereby the amount of swing of a distal end of the rod in a radial direction can be reduced.

An electronic watch may include a housing, a display positioned at least partially within the housing, a transparent cover coupled to the housing and at least partially covering the display, a battery, and a coil coupled to the battery and configured to, during a battery charging operation, supply a first current to the battery and, during a haptic output operation, receive a second current from the battery to produce a haptic output. The electronic watch may further include a ferromagnetic element positioned at least partially within the housing and movable relative to the housing. The second current may cause the coil to produce a magnetic field, and the haptic output may be produced as a result of an interaction between the magnetic field and the ferromagnetic element that causes the ferromagnetic element to move relative to the housing.