ZF Automotive UK Limited

A motor includes a stator and a rotor. The stator carries a plurality of phase windings and the rotor carries a plurality of magnet poles and is connected to a shaft. The stator has a ferromagnetic material defining a yoke and a plurality of teeth and further includes at least one band of electrically conductive material that encompasses at least a portion of one of the teeth or encompasses at least a portion of the yoke in a region between adjacent teeth and is in direct contact with the tooth. The band provides an electrical path between the band and the portion of the tooth or yoke. The band wraps around upper and lower end regions of the portion of the tooth or yoke and extends axially down the opposing side faces of the tooth or yoke. The band is isolated from any external source of motor drive current.

A steering column assembly for a vehicle includes an elongate steering shaft mounted for rotation about its longitudinal axis and configured for attachment of a steering member at one end. The steering shaft is rotatable in both directions from a position corresponding to a straight ahead position. A cam member has a cam surface. The cam member is constrained to rotate with the steering shaft. A cam follower is in contact with the cam surface. A lever is connected to a lever pivot and arranged to support the cam follower. A spring means is connected to the lever and biases the cam follower into contact with the cam surface via the lever. The spring means urges the cam follower to displace the cam member in a direction which returns the elongate steering shaft towards the straight ahead position.

A steering column assembly for a vehicle includes an elongate steering column mounted for rotation about its longitudinal axis and configured for attachment of a steering wheel at one end. A gear is connected to the steering column at a location spaced from the steering wheel attachment location and configured to rotate with the steering column. A motor has a rotatable output shaft. A first worm screw is directly connected to and rotatable with the output shaft of the motor and engaged with the gear. A damper includes a rotatable shaft. A second worm screw is directly connected to and rotatable with the shaft of the damper and engaged with the gear. A control means is configured to operate the motor.

A mechanical assembly is disclosed. The assembly comprises: a housing, a shaft rotatably mounted with respect to the housing, one or more motors each having a stator and a rotor, the stator carrying a plurality of phase windings and the rotor carrying a plurality of magnet poles and being connected to the shaft, a control circuit adapted to control the current flowing into or out of the or each motor to cause a net torque to be applied to the shaft during normal operation, and in which the stator of at least one of the motors comprises a stack of laminations which each comprise a steel plate and an electrically conductive coating at least on the faces of the steel plate that contact adjacent laminations.

A steering control system for a vehicle comprising a steering input member controlled by a driver of the vehicle comprises a steering sensor for generating an electrical signal as a function of the position of the input member. The steering control system further comprises a steering actuator which operates on the steered wheels of the vehicle as a function of the electrical signal generated by the steering sensor. A steering controller receives the electrical signal generated by the steering sensor and provides a current to the steering actuator in order to operate on the steered wheels. An accumulation counter is operatively connected with the steering controller and is configured to calculate and record the accumulated workload of the steering controller by accumulating instantaneous workloads throughout operation thereof.

A surface mounted permanent magnet motor includes a stator having poles and windings. A rotor includes magnets fixed to an outer surface of a support assembly. The stator poles face the outer surface of the rotor. The support assembly has magnetically conductive magnet carriers spaced from each other and supporting two magnets of opposing polarity. The magnet carriers have a central region of low permeability that blocks q-axis flux flowing from the stator radially towards the rotor axis surrounded by regions of high permeability. A first high permeability region defines a continuous flux path on the side of the barrier region closest to the rotor axis and links central regions of the two magnets carried by the magnet carriers. A second high permeability region is located on the side of the barrier nearest the stator that defines a flux path linking the end regions of the magnets.

A drive system comprises at least two electric motor subassemblies, each comprising a rotor and a stator. The rotors are connected to a mechanical load to fix a position between the two rotors. The system further comprises: first and second position sensing assemblies that provide first and second rotor position signals of first and second motor subassemblies, respectively. Each position signal is indicative of the position of the associated rotor relative to its associated stator including a periodic pattern of errors in the indicated position of the rotor. A motor controller controls the currents applied to each motor subassembly as a function of the position signal. The current causes each rotor to apply a force to the mechanical load which includes a force ripple due to periodic errors in position signals, in which: the orientation of the first and second rotor position sensing assemblies relative to the first and second motor subassemblies are fixed such that the periodic ripple in the forces applied by the two motors are seen by the mechanical load at least partially cancel out.

A method of controlling an electric power assisted steering (EPS) system includes the steps: During a first mode of operation of the EPS system driving a motor using two inverter bridges simultaneously, the nominal current that is applied to the motor at any time by each bridge being limited to a first value, and during a fault mode of operation driving the motor using only one of the two inverter bridges. The nominal current that is applied to the motor at any time in the fault mode is limited to a second value. The method varying the second value as a function of one or more operating parameters of the EPS system. The second value is set higher than the first value when it is deemed safe to do so.

A microprocessor system for a vehicle steer-by-wire steering apparatus, comprising: a hand wheel actuator controller, comprising first and second microprocessors, and arranged to provide control signals for a hand wheel actuator of the steering apparatus; a front axle actuator controller, comprising first and second microprocessors, and arranged to provide control signals for a front axle actuator of the steering apparatus; first and second private buses connecting the first microprocessor of the hand wheel actuator controller to the first microprocessor of the front axle actuator controller. The first private bus has a physical layer over which data can be transmitted with a first data link format and a second data link format different to the first data link layer format. The second private bus connects the second microprocessor of the hand wheel actuator controller to the second microprocessor of the front axle actuator controller. The second private bus comprises a physical layer over which data can be transmitted with either the first or second data link format. The microprocessor system is arranged to switch from the first state to the second state upon one of the first or second microprocessors of the hand wheel actuator controller or the front axle actuator controller determining that there is a fault on the first or second private bus.

A steering assembly for a steer-by-wire vehicle comprises a rotatably mounted steering column configured for attachment of a steering member at one end, the steering column being rotatable about its longitudinal axis. The steering assembly further comprises a damper having a housing defining a volume for receipt of damping fluid; a rotor within the housing, the rotor being coupled with the steering column and rotatable therewith; a stator mounted within the housing, the stator being moveable within the housing within a defined range of movement; and a biasing arrangement acting on the stator. Each of the stator and rotor comprises a shear surface, the shear surfaces of the stator and the rotor being positioned adjacent one another to generate a resistance to rotation of the rotor when the housing contains damping fluid. Furthermore, the total surface area of the shear surfaces of the stator and the rotor positioned adjacent one another which generates the resistance to rotation of the rotor varies as the steering column is rotated from the straight ahead position by virtue of displacement of the stator relative to the rotor.