A retention mechanism includes a fixed part including a magnet, and a movable part opposed to the fixed part. A plurality of rolling elements are provided between the fixed part and the movable part, and the movable part is movable in a plane direction. A magnetic material which forms, in combination with the magnet, a magnetic spring is provided on the movable part. The magnetic spring generates a magnetic attraction force which attracts the movable part to the fixed part. The magnetic material is extended along a direction in which magnetic poles of the magnet are arrayed.

A retention mechanism includes a fixed part including a magnet, and a movable part opposed to the fixed part. A plurality of rolling elements are provided between the fixed part and the movable part, and the movable part is movable in a plane direction. A magnetic material which forms, in combination with the magnet, a magnetic spring is provided on the movable part. The magnetic spring generates a magnetic attraction force which attracts the movable part to the fixed part. The magnetic material is extended along a direction in which magnetic poles of the magnet are arrayed.

A magnetic shock absorber having a first body slidably coupled to a second body via a first bearing arranged to move in sliding engagement with a first counter-face portion. A first array of magnets associated with the first body is arranged to magnetically interact with a second array of magnets associated with the second body to absorb compression or extension loads applied to the shock absorber. The first bearing and the first counter-face portion each have a non-circular cross section profile to inhibit axial relative rotation between the bodies.

Various examples of a variable stiffness magnetic spring with a linear stroke length are provided. The stiffness of the magnetic springs is varied through rotation of one or more magnets, and both positive and negative spring constants are achievable. In one example, a variable stiffness magnetic spring includes a first magnetic component and a second magnetic component, wherein the first magnetic component is coaxial with the second magnetic component, the first magnetic component is rotatable about an axis and relative to the second magnetic component to adjust a stiffness of the variable stiffness magnetic spring, and the second magnetic component is translatable along the axis and relative to the first magnetic component. While such variable stiffness magnetic springs exhibit highly linear stroke lengths, such variable stiffness magnetic springs can be positioned in series to achieve an even longer linear stroke length.

A system and method with a torque response linearly proportional to angular displacement between inner and outer rotors having magnets, forming magnetic poles, to provide a linear magnetic torsional spring with a wide operating region. Multiple rotor sections of magnetic poles in at least one of the inner and outer rotors are provided wherein at least one rotor section of magnets is circumferentially offset by an offset angle from at least one other rotor section of magnets. The magnetic torsional spring can produce linear torque T, where T=+/k , k is the angular spring constant, and is the angular displacement. The torque responses from each rotor section can cause a combined torque response to function as the linear magnetic torsional spring. The extended linear portion can provide a useful radial angle of rotation for a linear torque to counteract a spring force applied to the rotor.

According to the present invention there is provided an active vibration control system comprising: an electromagnetic actuator and a control element, the electromagnetic actuator being operable to apply a force on a base structure to which the active vibration control system is attachable such that vibrations of the base structure are actively controllable by the application of said force, wherein the electromagnetic actuator and control element are relatively moveable such that the active vibration control system has at least two modes of vibration, and wherein movement of the electromagnetic actuator causes movement of at least a part of the control element.

According to the present invention there is provided an active vibration control system comprising: an electromagnetic actuator and a control element, the electromagnetic actuator being operable to apply a force on a base structure to which the active vibration control system is attachable such that vibrations of the base structure are actively controllable by the application of said force, wherein the electromagnetic actuator and control element are relatively moveable such that the active vibration control system has at least two modes of vibration, and wherein movement of the electromagnetic actuator causes movement of at least a part of the control element.

A shock absorber includes a cylinder including a shock-absorbing surface configured to relieve an impact of an object, a piston rod including a first end receiving the object and, in response to the impact of the object, movably inserted into an inner space of the cylinder in an axial direction of the cylinder, a magnet installed at a second end of the piston rod opposite to the first end of the piston rod to be moved together with the piston rod, an electromagnet coil configured to generate a repulsive force against the magnet, and a sensor configured to detect the magnet and cause the electromagnet coil to receive a current from a power source.

A shock absorber includes a cylinder including a shock-absorbing surface configured to relieve an impact of an object, a piston rod including a first end receiving the object and, in response to the impact of the object, movably inserted into an inner space of the cylinder in an axial direction of the cylinder, a magnet installed at a second end of the piston rod opposite to the first end of the piston rod to be moved together with the piston rod, an electromagnet coil configured to generate a repulsive force against the magnet, and a sensor configured to detect the magnet and cause the electromagnet coil to receive a current from a power source.

A dynamically tuned vibration absorber includes a magnetic dynamic mass, a repulsive magnetic system, and an attractive magnetic system. The repulsive magnetic system includes one or more repulsive magnets positioned to resist translation of the dynamic mass away from an equilibrium position by magnetic repulsion. The attractive magnetic system includes one or more attractive magnets positioned to aid the translation of the dynamic mass away from the equilibrium position by magnetic attraction. The magnetic repulsion and the magnetic attraction collectively exert a net repulsive force on the dynamic mass that resists the translation of the dynamic mass away from the equilibrium position. One of the repulsive and attractive magnetic systems is a dynamically variable. The dynamically variable system includes at least one field manipulation actuator configured to move the one or more magnets of the dynamically variable system to adjust the net repulsive force exerted on the dynamic mass.