Patent ID: 11949310
Assignee: MINEBEA MITSUMI IN.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 0:
1. A vibration actuator, comprising:
a movable body including a core that is bar-shaped, a coil wound around on a bobbin externally applied between a tip part and a base end part of the core, the core extending on the coil axis of the coil,
a fixed body including one or more magnets disposed away from and facing the tip part of the core; and
a shaft part rotatably supporting the movable body at a position shifted from a longitudinal center of the core to a side of the base end part of the core, the vibration actuator generating vibration by oscillation of the tip part of the core around the shaft part with respect to the one or more magnets by energizing the coil, wherein
the one or more magnets are arranged in an oscillation direction of the movable body, each of the one or more magnets including two magnetic poles magnetized in a direction facing the tip part of the core, the one or more magnets, and the core forming a magnetic spring, the magnetic spring energizes the tip part of the core to be located at a position facing a switching position of the two magnetic poles and serving as a reference position, and
the core and the one or more magnets are disposed such that the magnetic spring has a spring constant that is largest when the tip part of the core is located at the reference position with respect to the one or more magnets, and that becomes smaller as the tip part of the core becomes away from the reference position by oscillation.