ELECTRIC POWER STEERING DEVICE AND VEHICLE PROVIDED WITH THE SAME

• Main Author: MAEDA ATSUSHI
• Format: Patent
• Language: English; Japanese
• Published: 21.12.2015
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; LIGHTING; MECHANICAL ENGINEERING; MOTOR VEHICLES; PERFORMING OPERATIONS; THERMAL INSULATION IN GENERAL; TRAILERS; TRANSPORTING; WEAPONS

PROBLEM TO BE SOLVED: To suppress a rattle noise caused by a gap inside a shaft bearing of a worm gear mechanical unit and backlashes while transmitting torque in a non-contact manner.SOLUTION: In an electric power steering device 9, an output shaft 13a is arranged eccentrically toward a worm wheel 22 side with respect to a worm shaft 21, and a magnetic reduction gear 30 having a pair of disks 31, 32 is provided at a joint part of the output shaft 13a and the worm shaft 21. The magnetic reduction gear 30 is provided with a permanent magnet pair 50 including a first annular magnet row 51 arranged on one disk face and a second annular magnet row 52 arranged on the other disk face. The first annular magnet row 51 and the second annular magnet row 52 are arranged such that different poles are disposed to oppose to each other in the axial direction, when respective plural permanent magnets are at positions where torque is transmitted between mutual disk faces in a non-contact manner, and the numbers of respective plural permanent magnets are set according to a gear reduction ratio. 【課題】トルクを非接触で伝達するとともに、ウォームギヤ機構部の軸受内部隙間およびバックラッシに起因するラトル音を防止または抑制する。【解決手段】電動パワーステアリング装置９は、出力軸１３ａがウォーム軸２１に対してウォームホイール２２側に偏心して配置され、出力軸１３ａとウォーム軸２１との継手部に一対のディスク３１，３２を有する磁気減速機３０を備え、磁気減速機３０は、一方のディスク面に配置された第一環状磁石列５１と、他方のディスク面に配置された第二環状磁石列５２とを有する永久磁石組５０を備え、第一環状磁石列５１と第二環状磁石列５２とは、互いの複数の永久磁石が、ディスク面相互間で非接触でトルク伝達する位置のときに異なる極が軸方向に対向するように配置されるとともに、互いの複数の永久磁石の数が減速比に応じて設定されている。【選択図】図２