A steering assembly for steering a vehicle in response to a steering input, the steering assembly includes an axle extending between a pair of wheels, a plurality of linkages, a primary electric drive source, and a secondary electric drive source. The plurality of linkages includes a pair of knuckles operatively coupled to the wheels, a tie rod extending between and coupled to the pair of knuckles, and a drag link attached to one of the knuckles. The primary electric drive source is operatively attached to the drag link, and moves the drag link in response to the steering input to transfer movement through the plurality of linkages to turn the wheels. The secondary electric drive source is operatively attached to one of the plurality of linkages to move the one of the plurality of linkages in response to the steering input and independently from the primary electric drive source.

A turning device includes a turning shaft having a first ball screw groove as one of a left screw and a right screw and a second ball screw groove as the other of the left screw and the right screw and turning wheels to be turned by moving in an axial direction, a first electric motor generating a first driving force, a second electric motor operating independently of the first electric motor and generating a second driving force, a first ball screw nut transmitting the first driving force generated by the first electric motor to the first ball screw groove, a second ball screw nut transmitting the second driving force generated by the second electric motor to the second ball screw groove, and a rotation regulating part regulating relative rotation of the turning shaft around an axis with respect to a housing.

A gear unit for a motor vehicle including a rotatable worm gear shaft rotating about a rotation axis and cooperating with a worm gear wheel in an engagement region spaced from the rotation axis. A pivotable rotary bearing mounts the worm gear shaft on a housing on one side of the engagement region and a loose rotary bearing, pretensioned in the direction of the spacing axis, mounts the other side in the housing. A support device supports the pivotable rotary bearing on the housing in the direction of the rotation axis. To optimize engagement between a worm gear shaft and a worm gear wheel, the pivotable rotary bearing pivots relative to the housing about a pivot axis perpendicular to the rotation axis and to the spacing axis. A support point of the support device is offset relative to the rotation axis along the spacing axis towards the engagement region.

According to the present embodiments, it is possible to mitigating noise by preventing degradation of lubrication performance due to mixture of greases with different properties in a gear housing.

A worm drive for a power steering system of a motor vehicle is disclosed. The worm drive includes a worm gear, a worm which meshes with the worm gear, and an electric motor which drives the worm. One side of the worm is connected by a coupling to the electric motor and the other side of the worm is mounted in a floating bearing. The coupling consists of a hub and an elastic spring bush. The floating bearing is oval-shaped in order to allow vertical movements of the worm, and the worm is spring-loaded on the worm gear by the coupling.

A torque transmission joint includes a first elastic body having a plurality of first elastic pieces pinched in a circumferential direction between respective first convex portions and a coupling, and a second elastic body having a plurality of second elastic pieces pinched in the circumferential direction between respective second convex portions and the coupling.

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.

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.

An assist mechanism includes: an electric motor in which a rotor has a magnet and a stator has a winding; 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.

A motor driven power steering device including a motor and a speed reducer configured to decelerate a rotation speed of the motor, wherein the speed reducer includes a worm gear coupled to a drive shaft of the motor and rotatably installed to a speed reducer housing through a bearing, a worm wheel gear-coupled with the worm gear, and a rotation member mounted between the worm gear and the bearing and configured to circulate a lubrication agent applied between the worm gear and the worm wheel.