Linear motor
AssigneeFanuc Corporation
InventorsTomonaga Yamamoto, Takuya Maeda
Life of this patent
Estimating the term…
Abstract
In a linear motor, magnetic poles on a stator (or moving element) and teeth on a moving element (or stator) face one another to form a gap. The gap-side surface of each of the magnetic poles or teeth has an external shape represented by a hyperbolic function or a reciprocal function of cosine. Thus, the cogging torque can be made lower than that of a conventional linear motor of which the magnetic poles (permanent magnets) or teeth have an external shape represented by a straight line, circular arc, parabola, or hyperbola.
Claims12
A linear motor characterized in that the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion consists mainly of a shape represented by a hyperbolic function.
A linear motor characterized in that the whole or a part of the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion is a shape represented by a hyperbolic function.
A linear motor characterized in that at least the central portion of the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion has a shape represented by a hyperbolic function.
A linear motor characterized in that the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion consists mainly of a shape represented by a reciprocal function of cosine in trigonometric function.
A linear motor characterized in that the whole or a part of the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion is a shape represented by a reciprocal function of cosine in trigonometric function.
A linear motor characterized in that at least the central portion of the external shape of the gap-side surface of each magnetic pole and/or tooth forming a gap portion is a shape represented by a reciprocal function of cosine in trigonometric function.
A linear motor of which the magnetic poles are formed by bonding cores to the top of permanent magnets or covering permanent magnets with cores, each said core being formed by laminating a plurality of steel sheets to one another, the cross section of the core having an external shape represented by a hyperbolic function or a reciprocal function of cosine in trigonometric function.
Dependencies are inferred from the claim text.