Jtekt Corporation

Noboru Niguchi

Naotake Kanda

Masaru Horikawa

Shigeki Nagase

Yuji Kariatsumari

Takeshi Ueda

Hiroshi Sumasu

Ken Matsubara

Hirohide Inayama

Toshimasa Soku

The invention provides a motor including: a cylindrical motor case having a bottom that supports an outer circumferential surface of a stator core by an inner circumferential surface thereof; and a bracket that supports an output shaft side bearing and closes an opening of the motor case; wherein the stator core is press-fitted into the motor case from the opening such that a part of the stator core is exposed from the motor case, and a part of the stator core that is not press-fitted to the motor case forms a sliding fitting wall capable of providing a sliding fitting connection with the bracket.

Motor and electric power steering system

A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value correctorcorrects the d-axis and q-axis current target values id*, iq* by the field weakening control such that d-axis and q-axis voltages vd, vq and d-axis and q-axis currents id, iq satisfy &#x221a;(vd+vq)&#x2266;Vlim and &#x221a;(id+iq)&#x2266;Ilim respectively. The d-axis and q-axis current command values idc, iqc are obtained by this correction.

Motor controller and electronic power steering apparatus

A permanent magnet included in a rotor of a brush-less motor is a radial anisotropic magnet in which multi-poles are magnetized in the circumferential direction and is skew magnetized along the axial direction in such a manner that a surface to one end part of an upper side from a central part in the axial direction and a surface to an end part of a lower side from the central part are axially shifted by a predetermined angle in the circumferential direction from each other. In accordance with this skew-magnetization, coggings including irregularly varying components generated in the rotor owing to the three-dimensional shapes of coil ends provided at opposite ends of a toothfor fixing a winding have opposite phases to each other, so that the coggings are cancelled with each other. Accordingly, the coggings can be reduced or cancelled.

Brush-less motor and electric power steering device having brush-less motor

A brushless motor includes a stator and a rotor. The stator includes an annular stator core having teeth arranged with a spacing in a circumferential direction of the annular stator core; and coils wound around the teeth respectively. The rotor includes a rotor core and magnetic poles of segment magnets arranged annularly along a circumferential direction of the rotor core. The segment magnets are stacked at a plurality of stages in an axial direction of the rotor core. A length direction of each of the segment magnets is parallel with the axial direction of the rotor core. The following expression is satisfied:(2&#xd7;&#x3b2;/)+&#x3b8;&#x3c;(360/)

Brushless motor

A brushless motor including a rotor which has ten permanent magnets each containing rare earth neodymium and provided around a rotor yoke and an outside diameter of 45 mm to 55 mm, and a stator which has a stator core having twelve slots and an outside diameter of 75 mm to 85 mm and whose magnetomotive force at maximum current is 700 AT or more. The stator core is configured such that a teeth width b is 0.14 times or more of the outside diameter of the rotor.

Brushless motor and electric power steering system

A brushless motor includes an annular stator and a rotor which has a plurality of permanent magnets alternately arranged in circumferential direction on the rotor to form poles and which is disposed within the stator to be rotatable with respect to the stator. The stator includes a cylindrical yoke and a plurality of teeth which are same in size one another, are connected to the yoke to extend therefrom toward the rotor, and are disposed at even interval in the circumferential direction. Width of each of the teeth in the circumferential direction is set to be greater than or at a vicinity of the value which is obtained by dividing outer diameter of the rotor by the number of the teeth and multiplying the result of dividing by &#x3c0;/2.

Growing community of inventors

Kashihara, Japan

Noboru Niguchi