Abstract: An electric power steering apparatus includes left and right swing arm members, right and left tie rods pivotally connected at inner ends to arm portions of the swing arm members via a relay rod pivotally connected to the arm portions at both ends, a rack-and-pinion device in which one end of a rack bar is connected to the arm portion of one of the swing arm members, and a steering input transmission system that transmits a steering input to the rack-and-pinion device. An electric steering assist force applying device is connected to the arm portion of the other swing arm member, and applies a force to assist the other swing arm member to swing.

Abstract: A vehicle, vehicle frame, and steering system usable with the vehicle and vehicle frame. The steering system including a first and second knuckle mounted to a vehicle frame and configured to rotate with respect to the vehicle frame to turn the wheels, and a pitman arm link rotatable relative to the vehicle frame. The steering system further includes a first tie rod operably connected to the first knuckle to the pitman arm link bracket via a pitman arm and pitman connector, and a second tie rod connecting the second knuckle to the pitman arm link. A pitman connector is rotatably operatively connected to the pitman arm link, wherein the pitman arm thereby transfers pivoting or rotational motion applied via a steering input from the pitman arm to the pitman arm link, to respective knuckles via the first and second tie rods.

Abstract: A steering system that is telescopically extendable and retractable using a motor driving force includes a motor, a telescopic steering shaft, a tube that supports the steering shaft such that the steering shaft is rotatable and that is movable with telescopic movement of the steering shaft, and a driving force transmission device that transmits a rotational driving force of the motor to the tube. The driving force transmission device includes a driving force converter that converts the rotational driving force of the motor to a linear driving force, and a coupling member that couples the driving force converter to the tube. The coupling member is breakable by an impact force applied thereto through the steering shaft and the supporting member during a secondary collision so as to decouple the driving force converter from the tube.

Abstract: A retractable steering column assembly includes a retractable portion. Also included is an electric actuator mechanism for translating and/or tilting the retractable portion. Further included is a latch moveable between a latched condition and an unlatched condition, the unlatched condition allowing manual adjustment of the retractable portion, the latched condition preventing manual adjustment of the retractable portion.

Abstract: A front portion structure for a vehicle includes a powertrain unit and a suspension cross member. The suspension cross member includes a load receiving portion as a part of the suspension cross member in a width direction of the vehicle positioned above the other parts. The powertrain unit includes an abutting portion abutting against the suspension cross member when the powertrain unit moves backward during a front collision of the vehicle. The abutting portion is arranged on a lower side of a differential case of a differential device provided in a transaxle of the powertrain unit and at a position facing the load receiving portion of the suspension cross member.

Abstract: A vehicle includes a frame, a subframe, a powertrain, a steering gear, and a bracket. The subframe is fastened to the frame at a subframe attachment point, and the subframe is movable relative to the frame along a collision path in response to a frontal collision. The powertrain is attached to the subframe. The steering gear is coupled to the subframe and disposed in the collision path between the powertrain and the subframe attachment point. The bracket is attached to the powertrain and disposed in the collision path between the powertrain and the steering gear. The bracket is positioned to wedge the steering gear between the subframe and the frame during the frontal collision to deform the subframe at the subframe attachment point.

Abstract: A snubber for a machine includes a housing, a shaft and a pinion that is coupled to the shaft. The housing is mounted on an implement of the machine. The shaft is rotatably received within the housing and operatively coupled to a movable component of the implement. The snubber also includes a cylinder defining a cavity, a piston slidably received within the cylinder, a rack coupled to the piston, and a hydraulic device. The cylinder is at least partly disposed within the housing. The piston divides the cavity of the cylinder into a first chamber and a second chamber. The rack engages with the pinion to convert a rotation of the shaft into a linear movement of the piston. The hydraulic device is in fluid communication with the cavity and controls a flow of fluid between the first chamber and the second chamber to oppose rotation of the shaft.

Abstract: There is provided a vehicle front portion structure including (1) a suspension member having (i) a front cross member and a rear cross member, and (ii) a side rail that couples vehicle width direction outside end portions of the front cross member and the rear cross member, (2) a lower arm whose vehicle width direction outside end portion is coupled to a front wheel and whose vehicle width direction inside end portion is coupled at least to a front side coupling portion and a rear side coupling portion of the suspension member, and (3) a weak portion that is formed in the front cross member on the vehicle width direction inside of a coupling point at which the lower arm and the front side coupling portion are coupled to each other and that is to be broken by a load input from the vehicle body front side.

Abstract: Disclosed are a system and a method for compensating friction due to rack bending in a motor driven power steering system. The system for compensating friction may include a rack bending signal processor and a friction compensation controller. The rack bending signal processor may determine whether a rack bar bends when a lateral force is transmitted to the rack bar in turn of a vehicle. The friction compensation controller may calculates a friction compensation torque by adding a counter-rack bending torque according to a bending displacement of the rack bar to a basic steering torque of a motor and control a current supplied to the motor to apply the friction compensation torque if it is determined that the rack bar bends.

Abstract: The present invention relates to a compact and light weight integral hydraulic power assisted steering gear arrangement comprising housing; a cylinder in the housing having pressure chambers; an axially bored rack piston slidably carried in the cylinder; an output shaft journaled on the housing for rotating about an axis with a sector gear; a worm extending in axial alignment into the bore of rack piston; an operating steering shaft journaled for rotation on the housing; a control valve positioned in valve chamber of the housing; and one or more covers fixed on to the housing through one or more locker wires for sealing the hydraulic fluid, supporting worm and output shaft. The rack piston is two separate components. The rack with axially bored helical grooves and a series of rack teeth is supported by rack supporter assembly on one side and by the piston on the other end.

Abstract: A steering system for a vehicle adapted to travel on a track or a guideway includes a drive shaft having a rotational axis and first and second substantially semicircular gear elements provided on the drive shaft and adapted to engage first and second racks, respectively. The first and second substantially semicircular gear elements are offset along the rotational axis of the drive shaft and are located about a common end of the drive shaft. The first substantially semicircular gear element engages the first rack when the drive shaft is rotated in a first direction while the second substantially semicircular gear element engages the second rack when the drive shaft is rotated in a second direction, the second direction being opposite to the first direction. Both first and second substantially semicircular gear elements engage the first and the second rack, respectively, when the drive shaft is in a neutral position.

Abstract: A steering system includes a wheel rotatable between on-center and off-center positions, and a shaft having teeth. The shaft defines a cavity and is rotatable about an axis that is perpendicular to the teeth. The system includes a nut having cogs defining grooves therebetween, wherein each tooth is matable with a groove. The system includes a lash adjuster translatable within the cavity, and a retainer contacting the adjuster and shaft, and configured for positioning the shaft along the axis as the wheel rotates. A center one of the gear teeth meshes with one of the grooves to define a first gap having a first thickness therebetween when the wheel is in the on-center position. An outer one of the gear teeth meshes with an outer groove to define a second gap having a second thickness that is greater than the first thickness when the wheel is in the off-center position.

Abstract: A vehicle having a power supply apparatus which is configured to supply an electric power to an external apparatus outside the vehicle, includes: a detecting unit which is configured to detect a state where a cable is pinched between an opening and closing member of the vehicle and an opening edge of an opening for the opening and closing member, the cable connecting the power supply apparatus to the external apparatus and being arranged in an interior of the vehicle; and an inhibiting unit which, when the detecting unit detects that the cable is pinched between the opening and closing member and the opening edge, is configured to inhibit running of the vehicle.

Abstract: A method for securing the assistance torque (15) supplied by an electric assistance motor (8) in a motor vehicle power steering system includes the steps of: estimating the force on the steering system rack from the torque exerted by the driver on the steering wheel (2), from the assistance torque (15), and optionally from other parameters such as the speed of the electric assistance motor; comparing a target assistance torque with an authorized assistance range, defined with respect to the estimated rack force (17) at any moment, and in the event the target assistance torque is maintained above predefined limits for a predefined duration, correcting and optionally interrupting the power steering.

Abstract: Disclosed is a rack bush and a rack pinion type steering apparatus having the rack bush for a vehicle, which can smoothly support a load in an axial direction and a vertical direction of a rack bar so that it is possible to reduce abnormal abrasion of the rack bush, reduce a rattle noise caused by external force transferred through the rack bar during movement of the rack bar, and prevent damage to the rack bar and a pinion through distribution of the load due to an external impact on the shaft.

Abstract: In a center-takeoff-type steering apparatus for a vehicle, radiant heat from a heat source such as an engine is shut off reliably. The bracket is fixed to a central portion of a rack bar for unitary movement, the rack bar moving in the lateral direction in accordance with a steering operation of a steering wheel. Ball joint mechanisms are assembled to the bracket. The ball joint mechanisms rotatably support the inboard ends of the tie rods, swing tie rods in accordance with the movement of the rack bar to thereby steer the left and right front wheels. The heat insulator is integrally formed to have an upper plate portion and a lower plate portion facing each other, and fixed to the bracket so as to cover the ball joint mechanisms.

Abstract: A method is provided for recognizing the fatigue of a driver of a vehicle. In the method a torque variable representing the torque applied to the steering wheel by the driver is detected, and the presence of fatigue of the driver is detected on the basis of the torque variable.

Abstract: A device for controlling torsional stiffness of a power steering system, may include a variable torsion bar, an input shaft that is connected with a steering wheel, a pinion shaft equipped with a pinion gear engaged with a rack bar of a steering gear box, wherein the input shaft and the pinion shaft are combined each other to form a guide hole and slidably receive the variable torsion bar therein, and an actuating apparatus that moves the variable torsion bar toward the input shaft or the pinion shaft along a longitudinal axis of the input shaft and the pinion shaft according to a hydraulic pressure so as to change a size of a cross-section of the device.

Abstract: A hydraulic power steering system for a vehicle, e.g., an electrohydraulic power steering system for a motor vehicle, includes a servo valve, the relative movement of whose control parts actuates a piston rod of a servo cylinder and changes at least one steering angle of a wheel which is operatively connected to the piston rod, and additionally has an electric servo motor which drives a rack with the servo cylinder for adjusting the steering angle of the wheel in the same direction. In order to provide an electrohydraulic power steering system which is as compactly arranged as possible in the region of its actuator and may be used flexibly for different classes of vehicle, the action of the rack and the piston rod of the servo cylinder is combined, in a parallel arrangement with one another, on an addition member for jointly adjusting the steering angle of the wheel.

Abstract: A motor vehicle wherein the steering includes: a steering bar including a rack steering component and a steered component fitted in a sliding manner; a rack housing passed through by the steering component and including a plate displaying a correction sliding rail receiving a roller; two correction arms; assembly elements of the rack housing suitable for allowing pivoting of the rack housing in a steering plane, around an attachment axis obliged to move in a direction contained in the steering plane and in a longitudinal plane of the chassis; a telescopic steering column; two steering gears connecting the steering component and the steered component to the stub pivot arms of the front guiding wheels. The correction slide rail follows a suitable curve such that the vehicle wheel stubs extend along directions that intersect, at each time, at the same point.

Abstract: A steering gear for a rack and pinion steering system, including a housing in which a steering rack is guided for displacement along its axis, has an auxiliary support which is located at an axial end of the housing, the auxiliary support limiting a bending of the steering rack.

Abstract: A method of determining steering rack rattle propensity of a rack and pinion steering assembly may comprise: simultaneously recording audio, and measuring acceleration of a rack, and right and left side tie-rod end loads; identifying rack rattle events from the audio recording; determining common characteristics of the measured rack acceleration and tie-rod end loads during the identified rack rattle events; creating a rack rattle index level; applying a predetermined force profile to a test rack and pinion steering assembly; measuring a test acceleration on the test rack and pinion steering assembly; calculating a test RMS level in a test frequency range using a test time constant; determining a rack rattle index value from the calculated test RMS level; and comparing the rack rattle index value to the rack rattle index level.

Abstract: A rotary slide valve, in particular for speed-dependent power steering systems in motor vehicles, has a torsion bar, a rotary slide, and a control bushing. The control bushing is pressed onto a pinion and the torsion bar is inserted into a torsion bar bore of the pinion. The control bushing is connected rotation-fast to the pinion by shaping. The torsion bar has teeth that are pressed into the torsion bar bore of the pinion and that connect the torsion bar to the pinion rotation-fast.

Abstract: In a motor-driven steering wheel position adjustment apparatus, a nut 17 being a driven member is mounted such that it can be detached from an inner column of a steering column, based on a shock load applied at the time of a secondary collision, and therefore a threaded rod of a feed screw mechanism does not have resistance with respect to displacement of the inner column in the forward direction at that time. Improvement in the protection of a driver at the time of a collision can thus be achieved, and, since an integrated member can be used for the threaded rod, silence during the position adjustment of a steering wheel by the feed screw mechanism can be ensured.

Abstract: A rack and pinion steering apparatus (10) comprises a housing (12). Helical teeth (60) of a pinion gear (54) meshingly engage teeth of a rack bar (42) and, during rotation of the pinion gear (54), result in an axial force. A shaft (86) connects with the pinion gear (54). Rotation of the shaft (86) effects rotation of the pinion gear (54). An assembly is interposed between the shaft (86) and the housing (12). The assembly comprises a first snap ring (142) that is attached to the shaft (86) and a second snap ring (144) that is attached to the housing (12). Interposed between the first and second snap rings (142 and 144) are only a fluid tight seal (146) for blocking fluid leakage from the housing (12) and a bushing (108) for enabling rotation of the shaft (86) relative to the housing (12) and for engaging the first snap ring (142) to block axial displacement of the pinion gear (54) due to the axial force acting on the pinion gear (54).

Abstract: This invention refers to an improved rack-and-pinion type steering apparatus for automotive vehicles comprising a cylindrical housing attached to a body structure of the vehicle, and a steering rack shaft mounted within the housing for sliding movement therethrough. Opposite ends of the steering rack shaft are coupled to left and right tie rods through ball joint assemblies to steer a set of road wheels in accordance with lateral displacement of the rack shaft. The rack-and-pinion type steering apparatus further includes a pair of protective boots of elastomeric material, each defining left and right ball joint chambers for sealing a steering gear and components of the ball joint assemblies against debris and foreign fluids. Furthermore, the steering apparatus of the present invention includes a pressure equalization system for equalizing pressure in the left and right ball joint chambers.

Abstract: An end cap arranged to slidably support a rack, is inserted into an end of a housing in which the rack is inserted. A cir-clip is interposed between the housing and the end cap to prevent the end cap from being moved axially of the rack. The cir-clip is provided at one end thereof with (i) an inwardly bent curved portion and (ii) a linear portion linearly extending inwardly from the tip of the curved portion and having a tip which always comes in contact with the bottom of an annular groove of the end cap.

Abstract: A damper for a vehicle rack and pinion-type power steering system reduces or eliminates high frequency and low amplitude vibrations commonly associated with high-speed steering wheel shake. The damper includes a hydraulically actuated clutch that is energized by a spring in the damper. The damper locks or inhibits rotation of a steering shaft coupled to the rack and pinion assembly while the vehicle is traveling straight down the road to absorb the input energy and cancel any vibration from the wheels, suspension or road. The clutch is released when there is any steering wheel input from the operator. Increased pressure from the power steering pump as a result of steering wheel input increases the pressure in the damper to compress a spring and release the multi-disk clutch. This allows the steering system to behave in an acceptable manner by not adding any friction or extra force requirements to the driver and providing acceptable feel and return to center characteristics for the steering system.

Abstract: A damper for a vehicle rack and pinion-type power steering system reduces or eliminates high frequency and low amplitude vibrations commonly associated with high-speed steering wheel shake. The damper includes a hydraulically actuated clutch that is energized by a spring in the damper. The damper locks or inhibits rotation of a steering shaft coupled to the rack and pinion assembly while the vehicle is traveling straight down the road to absorb the input energy and cancel any vibration from the wheels, suspension or road. The clutch is released when there is any steering wheel input from the operator. Increased pressure from the power steering pump as a result of steering wheel input increases the pressure in the damper to compress a spring and release the multi-disk clutch. This allows the steering system to behave in an acceptable manner by not adding any friction or extra force requirements to the driver and providing acceptable feel and return to center characteristics for the steering system.

Abstract: To provide the electric motor assist type power steering apparatus, which can prevent the aggravation of the feeling of the steering, and which can transmit the assist steering force brought by the electric motor to the steering shaft completely, by preventing the flexure of the worm shaft of the electric motor assist type power steering apparatus, preferably the pinion assist type electric power steering apparatus.

Abstract: A pinion adjustable assembly for steering mechanisms for automotive vehicles, a pinion-rack set incorporated in a pinion housing and a tubular cylindrical bushing with free angular displacement that is positioned inside the housing and is coupled to an angular positioning nut. The said bushing has an eccentric inner wall with regard to outer wall surface surrounding a pinion housing. Angular displacement of said bushing by angular movement changes its eccentricity to allow the pinion to move relative to the rack bar for overcoming wearing out effect on teeth.

Abstract: A rack and pinion steering gear (10). The rack and pinion steering gear (10) comprises a housing (12) having a chamber (18). A portion of the chamber (18) is a relief pocket (22). A pinion gear (26) is rotatably mounted in the chamber (18) of the housing (12). A rack bar (38) is movable relative to the pinion gear (26). The rack bar (38) is at least partially disposed in the chamber (18) of the housing (12) and has teeth (44) in meshing engagement with the pinion gear (26). A spring (60) is disposed in the chamber (18) of the housing (12) for supporting and guiding movement of the rack bar (38) relative to the pinion gear (26). The spring (60) extends across an opening to the relief pocket (22). The spring (60) extends into the relief pocket (22) as a load applied to the spring (60) from the rack bar (38) increases.

Abstract: An electric power steering apparatus having a rack and pinion movement converting mechanism for converting rotation movement of a steering wheel into linear movement by engagement between a pinion shaft and a rack shaft. A motor for assisting a driver's steering force asserted on the steering wheel is provided along with the rack and pinion movement converting mechanism and, an elastic body is inserted in a mechanism passage from the pinion shaft to an output shaft of the motor to produce system with low load exerted on the steering mechanism and with reduced rattle and reduced influence from frictional force of a power assisting motor.

Abstract: A vehicle steering system includes a rack and pinion mechanism having a pinion functionally coupled to a steering wheel and a rack meshing with the pinion and functionally coupled to steerable wheels and a mechanism for displacing the rack in the axial direction thereof to steer the steerable wheels independently of steering operation initiated by the steering wheel. The rack and pinion mechanism comprises a variable gear ratio rack and pinion mechanism having a variable gear ratio, which is the lowest when the steering wheel is in a neutral position and becomes higher as the steering angle of the steering wheel becomes large.

Abstract: In an electric power steering device, the rotation of an electric actuator for generating auxiliary steering power is transmitted to a vehicle wheel by way of a worm and a worm wheel. The worm wheel is molded from a synthetic resin material. The relative viscosity (VR) of the molded worm wheel is made greater than or equal to 100 and less than or equal to 300.

Abstract: The rack-and-pinion steering gear, in particular for controlling motor vehicles, in order to compensate for the deviations in planarity between the thrust piece and the set screw, has a compensating disk acted upon by a spring on one side; the top side of the compensating disk is embodied spherically and engages the inside of a recess, adapted to it, of the thrust piece, and its underside is partly curved, so that the requisite variation in spacing between the thrust piece and the set screw that is required to compensate for toothing deviations is constantly spanned while maintaining a contact.

Abstract: An electromechanical steering actuator for a steer-by-wire application in motor vehicles. An electronic closed-loop/open-loop control system generates steering signals for a pair of electric servomotors, which act via a gear unit on a steering control element of a rack-and-pinion steering system. The closed-loop/open-loop control system includes a pair of process computers which deliver corrective signals to the servomotors via drive units. The steering actuator is divided into two diversely redundant systems including two redundant process computers, each of which delivers corrective signals via two redundant drive units to two servomotors which act on a common steering shaft.

Abstract: An apparatus (10) includes a hydraulic fluid power cylinder (116) and a steering rack (118). The rack (118) is fixed to a piston (160) in the power cylinder (116), and extends outward through an open end (172) of the power cylinder (116). An annular hydraulic fluid seal (164) is received over the rack (118) in dynamic sealing contact with the rack (118). The seal (164) defines a fixed end of a variable volume hydraulic fluid chamber (173) extending from the piston (160) to the seal (164). The apparatus (10) further includes a housing part (114) which is mounted on the power cylinder (116). The housing part (114) supports the seal (164) at a location spaced outward from the open end (172) of the power cylinder (116). In this arrangement, the housing part (114) defines an end section (191) of the fluid chamber (173) extending outward from the open end (172) of the power cylinder (116) to the seal (164).

Abstract: In a wire-type steering device in which a steering wheel and a gear box are connected to each other by wires, one end of each inner cable of two Bowden wires are wound around a driving pulley which is mounted on a rotary shaft of a steering wheel. The inner cables are inserted through the inside of outer tubes fixed at their corresponding ends to a driving pulley housing. The direction of drawing of the Bowden wires from the driving pulley housing is offset at an angle .alpha. in a forward direction of a vehicle body relative to a plane perpendicular to the rotary shaft 12, thereby preventing the Bowden wires from being exposed inside of a vehicle compartment, and/or from interfering with an instrument panel and the like.

Abstract: A rack guide (30) in a rack and pinion steering gear housing (12) comprises a cylindrical structure having a peripheral wall (42), an end wall (52), and an inner wall (71). The peripheral wall (42) has an outer surface (40) with a contour complementary to an inner surface (44) of the housing (12). The end wall (52) has a rack guide surface (54) configured to engage the rack (14) in line contact along a first straight line (57) parallel to the longitudinal axis (17) of the rack (14). The inner wall (71) has a linear configuration adjoining the end wall (52) along a second straight line (101) parallel to the first straight line (57).

Abstract: To adjust the maximum torque required to actuate a hydraulic steering mechanism, the steering mechanism is first adjusted to provide a relatively high preload on gear teeth in the steering mechanism. The steering mechanism is then operated through a predetermined number of break-in cycles. After oil has been purged from the steering mechanism the steering mechanism is operated through one complete operating cycle and the location where the maximum torque is required to effect operation of the steering mechanism is noted. Preload between the gear teeth is then reduced and the steering mechanism is operated to the position where it was previously noted that maximum torque was required to actuate the steering mechanism. The steering mechanism is there dithered to either side of the location where the maximum torque was required. As this is done, the steering mechanism is adjusted to obtain the desired maximum operating torque for the steering mechanism.

Abstract: A power steering gear for a motor vehicle including a pinion head and a spool shaft rotatable relative to each other, a torsion bar between the spool shaft and the pinion head, a valve spool formed integrally on the spool shaft, a valve body closely received on the spool shaft around the valve spool and rotatable relative to the spool shaft, and a tripod joint coupling the valve body to the pinion head for unitary rotation and consisting of three equally angularly spaced slots in an end of the valve body and three equally angularly spaced radial pins on the pinion head each having a spherical lobe closely received in a corresponding one of the slots in the valve body. An inboard end of the spool shaft adjacent the pinion head is unsupported laterally on the pinion head except through the valve body and the tripod joint and, consequently, floats with the valve body in the event of lateral runout between the pinion head and the spool shaft to minimize valve hysteresis attributable to such lateral runout.

Abstract: A rack and pinion are housed in a gear box, a valve sleeve that is joined to the pinion being housed in a valve housing such that the sleeve is free to rotate. A mechanism is provided that joins the gear box and valve housing in any desired relative rotation position. As the gear box and valve housing are formed independently, they may be formed by different manufacturing methods, and replacement of either of them is also easy. Further, an oil pressure port provided at a fixed position in the valve housing may be disposed at any desired rotation angle by selecting the relative rotation position of the gear box and valve housing.

Abstract: The invention relates to a servo-assisted rack-and-pinion steering system having a helical-toothed rack and an axially movable pinion which interacts therewith and the axial movement of which controls the servomotor. The pinion is mounted on an input shaft in such a manner as to be incapable of rotation with respect to the shaft but axially movable thereon, in order to suppress the transmission of axial forces between the input shaft and the pinion.

Abstract: A bifurcated rack bearing assembly for a steering system includes a bearing member having a pair of bearing surfaces and which is pivotable within a base. The bearing member has a pair of curved riding surfaces which slide on a curved saddle surface of the base to permit the bearing surfaces to pivot into alignment coaxial with an axis of translation of the rack. The bifurcated rack bearing assembly can be substituted for the rack bearings of conventional steering systems.

Abstract: A servo-assisted rack-and-pinion steering system includes a rack which cooperates with a pinion which is capable of limited movement transversely or, in particular, parallel to the longitudinal axis of the rack. The movements actuate the servomotor or its control elements.

Abstract: The hydraulic power steering system comprises a rotary valve unit actuated according to a twisting angle provided in a torsion bar connected between an input shaft and a pinion, and a conversion mechanism which can change the condition of the rotary valve unit for a given twisting angle of the torsion bar. A variable ratio lever mechanism may be used for this purpose. Thus, a torsion bar having a suitable rigidity can be used without causing any insufficiency in the assisting torque because the responsiveness of the steering system can be freely varied by changing the setting of the conversion mechanism. For instance, it is possible to provide a sufficient assist torque at low speed and a controlled responsiveness at high speed.

Abstract: An electrically assisted power steering system for a motor vehicle includes a housing, a shaft slidably supported in the housing, a ball-and-nut mechanism operatively mounted on the shaft, and an electric motor mounted in the housing for transmitting rotary force from the electric motor through the ball-and-nut mechanism to the shaft. The ball-and-nut mechanism including a nut assembly disposed around the shaft and having one end rockably and rotatably supported in the housing by a four-point contact bearing or an automatic aligning bearing, and a plurality of balls movably held between an opposite end of the nut assembly and a screw groove defined in the shaft.

Abstract: A servo-assisted rack-and-pinion steering system has a helical-toothed rack and a helical-toothed pinion cooperating therewith. On the transmission of forces between the pinion and the rack, a torque relative to the longitudinal axis of the rack acts on the rack. The resulting rotation of the rack is utilized to control the servomotor via a lever arrangement.