A gearbox assembly for power take off from an electric motor of an electric power assisted steering apparatus comprising a gearbox housing which houses a worm shaft and a gear wheel, is disclosed. The worm shaft incorporates one or more external helical worm teeth. A main bearing assembly supports the worm shaft at an end closest to the motor. A tail bearing assembly supports the worm shaft at an end furthest from the motor, in which at least the tail bearing assembly is free to move relative to the housing through a limited range of motion that enables the worm shaft to move radially away from the axis of the wheel gear. The gearbox assembly further comprises a flexible coupler which connects the worm shaft at the main bearing end to a power take off from the motor so as to transfer torque from the motor to the worm shaft. The flexible coupler comprises a first hub part providing a connection to the worm shaft, a second hub part providing a connection to the power take off from the motor, and a flexible membrane that connects the first hub part to the second hub part. The flexible membrane provides a primary path for the transfer of torque from the first hub part to the second hub part.

A steering column assembly for a vehicle, comprises: an elongate steering column mounted for rotation about its longitudinal axis and configured for attachment to a steering wheel at one end; a first gear connected to the steering column at a location spaced from the one end to which the steering wheel is attached and configured to rotate with the steering column; first and second motors, each having an output shaft; first and second worm screws directly connected to and rotatable with the output shaft of the first and second motors respectively and engaged with the first gear; a control arrangement configured to operate the first and second motors; and a motor position sensor arrangement for sensing the rotational position of the motor output shafts, each sensor arrangement comprising a target member fixedly mounted to a respective motor output shaft on the opposite side of the worm screw from the motor and a sensor for detecting the target member.

An electric power steering device including a first bolt boss of a second housing provided on a first housing side relative to a worm-wheel accommodating portion of the second housing, and has a first female thread portion open on the first housing side and located within a plane area defined by connecting a second pinion shaft, a first bracket hole, and a second bracket hole; and a first bolt boss of the first housing provided to the first housing to be opposed to the first bolt boss of the second housing, and has a first bolt hole located within the plane area defined by connecting the second pinion shaft, the first bracket hole, and the second bracket hole and being formed through the first housing to be continuous with the first female thread portion of the first bolt boss of the second housing.

Disclosed herein are a sensor mounting structure of an electric power steering apparatus and an electric power steering apparatus having the same. The sensor mounting structure of an electric power steering apparatus includes a housing having a first accommodation part of which one side surface is open to accommodate a worm wheel and a second accommodation part which communicates with the first accommodation part and accommodates a worm shaft, a sensing unit disposed such that the sensing unit is spaced a predetermined distance from and faces the worm wheel, and a fastening means which fixes the sensing unit to the housing.

A three ball pin-type coupling, having a first connector and a second connector which are non-rotatably connected. The first connector includes a three shaft pin assembly, raceway assemblies and a cage assembly. The three shaft pin assembly includes a shaft and three ball rings which surround the shaft and are arranged at intervals in the circumferential direction of the shaft. There are three raceway assemblies. Each ball ring is connected to a raceway assembly. The cage assembly defines the position of the raceway assemblies in the circumferential direction. The raceway assemblies can provide elastic force between the ball ring and the cage assembly. When the ball ring displaces relative to the cage assembly in the circumferential direction, the two sides of the raceway assemblies in the circumferential direction remain abutted against the cage assembly. A steering mechanism is also provided.

A vehicle steering device includes a first setting portion 41 that sets a target assist torque in accordance with a steering torque, a second setting portion 42 that sets an angle controlling target torque for bringing an angular deviation between a target steering angle and an actual steering angle close to zero, an estimator that estimates a compensation object 43 load with respect to the angle controlling target torque, a first calculating portion 44 that calculates a target automatic steering torque based on the angle controlling target torque set by the second setting portion and the compensation object load estimated by the estimator, and a second calculating portion 44 that performs weighted addition of the target automatic steering torque and the target assist torque in accordance with a value that changes in accordance with a driver input to calculate a target motor torque that is a target value of a motor torque of the electric motor.

An assist mechanism includes: an electric motor; a shaft-shaped member in which a worm engaged with a worm wheel is formed; and a coupling that couples an output shaft of the electric motor and the shaft-shaped member to each other. The smallest rotation order among rotation orders of the electric motor and a rotation order of the worm are prime to each other. The smallest rotation order among the rotation orders of the electric motor and a rotation order of the coupling are prime to each other. The rotation order of the worm and the rotation order of the coupling are prime to each other. The rotation order of the worm is 3. The rotation order of the coupling is 5 or 7.

An assembly of a gear and rotating shaft, comprising: a gear having teeth on an outer peripheral surface thereof, and a center hole penetrating in an axial direction through a center portion thereof; and a rotating shaft including a serrated shaft portion having a male serration portion on an outer peripheral surface thereof and press-fitted into the center hole, and a guide shaft portion provided adjacent to one side in the axial direction of the serrated shaft portion and having an outer diameter capable of being internally fitted in the center hole with a clearance fit.

An electromechanical steering system may include a reduction gearbox where a worm gear is mounted in first and second bearings rotatably about a longitudinal axis. Rolling elements are disposed between inner and outer rings of the bearings. The inner rings are rotationally fixed on a shaft driven by the worm gear. A spring element is disposed between the inner ring of the second bearing and the worm gear. The spring element has an at least partially annular main body that when installed extends coaxially with the longitudinal axis. Spring arms in a circumferential direction are spaced apart from the longitudinal axis emanating from an external circumferential side of the main body. A first spring arm has a first leg that points away from the longitudinal axis and a second leg on which a free end is disposed, with the second leg running at least partially parallel to the longitudinal axis.

A gearbox assembly for power take off from an electric motor of an electric power assisted steering apparatus comprises a gearbox housing which houses a worm shaft and a gear wheel. The worm shaft incorporates one or more external helical worm teeth. A main bearing assembly supports the worm shaft at an end closest to the motor. A tail bearing assembly supports the worm shaft at an end furthest from the motor. At least the tail bearing assembly is free to move relative to the housing through a limited range of motion that enables the worm shaft to move radially away from an axis of the wheel gear. A piston is slidingly received within a bore in an end of the wormshaft and has a has a head at an end facing the motor which connects with an output shaft of the motor. An interface between the recess of the piston and the protrusion of motor shaft defines a pivot axis of the worm shaft. A spring located within the bore in the end of the worm shaft and is compressed between the worm shaft. The piston has a tapered shoulder located within the bore that increases in diameter from an end furthest from the motor towards an end nearest the motor. The gearbox assembly further includes an annular o-ring that sits on the tapered shoulder, the spring acting on the piston through the o-ring whereby movement of the wormshaft towards the motor shaft compresses the spring which in turn drives the o-ring along the tapered shoulder until the o-ring becomes wedged between the piston and the inner wall of the bore of the wormshaft.