Patent application number | Description | Published |
20090255752 | BALL SCREW MECHANISM AND ELECTRIC POWER STEERING DEVICE USING THE SAME - In a ball screw mechanism, a retainer is provided between an outer circumference of a ball screw shaft and an inner circumference of a ball nut and has a plurality of retainer grooves arranged in the circumferential direction for retaining a plurality of rolling balls. Each retainer groove of the retainer takes a form that allows the rolling balls therein to move radially outward but restrains the rolling balls therein from moving radially inward. Therefore, in the ball screw mechanism and an electric power steering device incorporating the same, the movement of the retainer in radial directions can be restricted by the plurality of rolling balls which are rolled along ball rolling grooves spirally formed respectively on the outer circumference of the ball screw shaft and the inner circumference of the ball nut. | 10-15-2009 |
20100200326 | ELECTRIC POWER STEERING APPARATUS - A flange member | 08-12-2010 |
20100206656 | BALL SCREW UNIT AND ELECTRIC POWER STEERING APPARATUS - A fitting recess portion that connects fitting holes to each other is formed in a peripheral face of a ball screw nut. A circulation member includes a pair of fitted portions that are fitted in the fitting holes, and a connecting portion that provides communication between the fitted portions. A communication groove that has an opening on the fitted end side of the connecting portion and that extends in the axial direction is formed in the connecting portion. When the connecting portion is fitted in the fitting recess portion and the opening of the communication groove formed in the connecting portion is blocked by a bottom portion of the fitting recess portion, a second path that forms a return path together with first paths formed in the fitted portions is formed. | 08-19-2010 |
20110048838 | ELECTRIC POWER STEERING SYSTEM - In an electric power steering system, multiple cutouts ( | 03-03-2011 |
20110048839 | ELECTRIC POWER STEERING SYSTEM - In an electric power steering system, a ball screw nut ( | 03-03-2011 |
20130081899 | ELECTRIC POWER STEERING SYSTEM - Assist force that assists an operation of a steering system of a vehicle is applied to a rack shaft by transmitting driving force of a motor to the rack shaft via a motor shaft and a ball screw nut. A step is formed on the outer periphery of the ball screw nut. An end portion of a third housing is arranged to face a bearing such that the distance that the ball screw nut is able to move relative to the motor shaft in axial direction and the relative movable length is longer than a predetermined length. | 04-04-2013 |
20130233103 | ELECTRIC POWER STEERING SYSTEM - A return passage that connects two points of a rolling passage to allow each ball that rolls in the rolling passage to endlessly circulate is formed in a ball screw nut by attaching a circulation member to fitting holes. A protrusion is formed on an outer surface of the circulation member at a position offset from a raceway of the balls that circulate in the return passage. The circulation member is fixed to the ball screw nut when the protrusion contacts an inner periphery of an inner ring of a second bearing. | 09-12-2013 |
20130324345 | TORQUE LIMITER, VARIABLE TRANSMISSION RATIO DEVICE, AND TOLERANCE RING - This torque limiter is configured from a ring body and a spring-form part provided in the ring body. The ring body comprises a band-form metal plate and is bent approximately into a C-shape along the circumferential direction of a motor shaft and a lock holder. The spring-form part is formed so as to be capable of radial elastic deformation. The spring-form part is configured from main protrusions arranged in a compressed state between the motor shaft and the lock holder, and from sub-protrusions arranged in a non-compressed state. Further, grease is stored in a part or all of the concavities formed by the main protrusions and the sub-protrusions. | 12-05-2013 |
20140027196 | ELECTRIC POWER STEERING APPARATUS - An electric power steering apparatus transmits rotational force of a motor to a rack shaft via a driver pulley, a belt, a driven pulley, and a ball nut. A ball bearing and the driven pulley are fitted to the outer circumferential surface of the ball nut. Also, the ball nut is rotationally supported to the inner circumferential surface of a housing via the ball bearing. A female thread portion is formed on the inner circumferential surface of the driven pulley. The ball nut has a male thread portion formed in a first end and a flange formed in a second end. By fastening the male thread portion and the female thread portion to each other, the ball bearing is clamped between the flange and the driven pulley, while the ball nut and the driven pulley are fastened to each other. | 01-30-2014 |
20140290410 | BALL SCREW DEFLECTOR - In an electric power steering system, there is provided a ball screw deflector configured to make it possible to easily measure the whole length of each of deflector pieces. A mating face of each of the deflector pieces and end faces of the deflector pieces are parallel to each other, and have an angle corresponding to a lead angle of a ball screw portion. Thus, it is possible to reduce the amount of material required to form each of the deflector piece pieces. In addition, it is possible to easily measure the overall length of each of the deflector pieces with the use of measuring equipment such as a vernier caliper. | 10-02-2014 |
20140345966 | ELECTRIC POWER STEERING SYSTEM - An electric power steering system includes: a steered shaft, a housing containing the steered shaft therein in a movable manner; a ball screw nut engaged threadedly to the steered shaft via a plurality of balls and configured to move the steered shaft in an axial direction; a double row angular contact ball bearing configured to retain the ball screw nut and to support the retained ball screw nut rotatably relative to the housing; a wall portion placed at either side of the double row angular contact ball bearing in the axial direction of the steered shaft, the wall portion being formed integrally with the housing; and an elastic member provided between the wall portion and the outer ring portion and configured to retain the double row angular contact ball bearing to be elastically displaceable in the axial direction. | 11-27-2014 |