Thk Co., Ltd.

Junichiro Iwaki

Takashi Ogata

Toji Nakazawa

Provided is a linear actuator wherein a moving element can be moved in a direction normal to the direction of arrangement of coils. The moving elementhas first to third magnets-arranged in the X-direction. Each of the first to third magnets-has N poles and S poles arranged in the &#x3b8;-direction. The N poles and S poles of the second magnetare shifted in the &#x3b8;-direction relative to the N poles and S poles of the first magnet. The N poles and S poles of the third magnetare shifted in the &#x3b8;-direction relative to the N poles and S poles of the second magnet. A statorhas at least two salient polesarranged in the &#x3b8;-direction, and at least two coilswound around the salient poles

Linear actuator

Provided is a linear actuator whose entire length can be shortened while thrust thereof can be made large. The linear actuator of the present invention is provided with the following: a hollow drive magnet (); a coil () disposed at either the outside or the inside of the drive magnet (); and a return magnet () that is disposed at the other of the outside or the inside of the drive magnet (), is connected to the coil (), and returns the drive magnet () to the starting point. By conducting electricity to the coil (), the drive magnet () or the coil () and the return magnet () move in the axial direction of the drive magnet

Provided is a sound reduction or vibration damping apparatus that has a new sound control principle where the sound control principle is totally different from a known passive or active sound control apparatus. A sound reduction or vibration damping apparatusincludes a mass portion, spring portionsandplaced between the mass portionand a structural member, and a control unitfor causing the spring constants of the spring portionsandto continue changing. The sound reduction or vibration damping apparatusis mounted on the structural memberto reduce sound passing through the structural memberor sound generated from the structural member, or damp the vibration of the structural member

Sound reduction or vibration damping apparatus and structural member

Provided is a linear motor actuator capable of oscillating a mover without using mechanical resilience of an elastic body. A first permanent magnetand a second permanent magnetmagnetized in an axis direction are disposed in a moverin the direction of the axis. A first coiland a second coilare disposed in a statorso as to surround the first permanent magnetand the second permanent magnet, respectively. Alternating currents having the same phase are applied to the first coiland the second coilsuch that the phase of thrust generated in the first coiland that of thrust generated in the second coilare shifted from each other. At this moment, a center-to-center pitch LCbetween the center of the first coiland that of the second coilin the axis direction differs from a pole-to-pole pitch LMof the mover.

Linear motor actuator

Power assist control capable of responding to feeling and sensibility when a man applies force to an object is performed. The power assist control outputs an assist force F or a speed F on the basis of an assist target force X detected by a force sensorfor detecting force applied to the object. The relationship between the assist target force X and the assist force F or the speed F to be outputted is F&#x221d;f(X) on the basis of a function f(X) having the assist target force X as a variable. The function f(X) is assumed to be a non-linear function which is an increasing function and whose derivative f'(X) is a decreasing function. The function f(X) is a (1/n)-th order function or a logarithmic function. Moreover, a function fup(X) when the assist target force X is increased is different from a function fdown(X) when the assist target force X is decreased.

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Tokyo, Japan

Junichiro Iwaki