2747results about "Mechanical steering gears" patented technology

A wear compensator for use in a vehicle rack and pinion steering assembly and a method of biasing a rack against a pinion shaft gear in a rack and pinion steering assembly are disclosed. The wear compensator may include a rack follower, an adjuster plug, a wear cam and a torsion spring. The rack follower slides on the rack. The adjuster plug is retained by the steering gear housing and includes a plug cam surface. The wear cam includes a wear cam surface operatively engaging the plug cam surface, is mounted between the rack follower and the adjuster plug, and can rotate relative to the adjuster plug. The torsion spring connects between the adjuster plug and the wear cam in order to rotatably bias the wear cam relative to the adjuster plug.

The invention relates to a steering-mode adjustable electric automobile steering system and a control method. The steering-mode adjustable electric automobile steering system comprises two motors, a mechanical steering module, an electric assisting steering module and a steering-by-wire module, wherein the two motors are arranged on a steering column and a steering pinion respectively, the mechanical steering module, the electric assisting steering module and the steering-by-wire module are formed by three electromagnetic clutches and the like and are used for mechanical steering, electric assisting steering and steering-by-wire. The control method mainly includes the first step of carrying out system initialization, the second step of allowing an ECU to start the corresponding steering mode and carrying out control according to the steering mode selected by a driver, the third step of controlling the steering modes, and the fourth step of carrying out fault diagnosis and fault-tolerant control on the steering system. The steering-mode adjustable electric automobile steering system and the control method have the advantages that the same automobile has high control flexibility on the precondition of being simple in structure, and consequently switching of driving modes can be achieved; when one motor breaks down, an original steering mode can be switched to a steering column assisting type electric assisting steering mode or a pinion assisting type electric assisting steering mode or a mechanical steering mode, and consequently the operation stability, reliability and the fault-tolerance capacity of the automobile are improved.

In a broad respect, vehicles that are capable of making a low- to zero-radius turn using the independent rotation of drive wheels and by turning the non-driving steerable structure or structures (such as wheels) with a steering input device (in some embodiments, the driving wheels also may be capable of being turned). This may be accomplished using a steering system, a speed control system and an integration device (together, a control system) that are configured to work together to provide correct steering in forward and reverse, and, in some embodiments, to reduce the speed of the outboard drive wheel of the vehicle when it enters an extreme turn under constant speed input. Different systems configured for use in such vehicles are included.

A rack and pinion steering gear assembly including a housing, a rack that is translatably moveable relative to the housing along an axis and a bushing operably disposed between the rack and housing. The bushing defines a gap which extends the entire axial length of the bushing. At least one compressible member may be disposed between the bushing and the housing with the compressible member extending across the gap in the bushing and fully encircling the bushing. The bushing may also include a radial flange that acts as a travel stop. The bushing may also be formed of an acetal material wherein the flange and a tubular portion of the bushing are axially separated by an intermediate portion having a relatively thin radial thickness. Axially extending recesses may be provided to enhance the flexibility of the bushing.

The invention provides a thrust bearing for the screw of a ball-nut type steering gear. The thrust bearing comprises a screw. A thrust ball type thrust bearing is arranged on screw. The thrust ball type thrust bearing comprises a steel ball and a ring. The ring is composed of a left semi-ring and a right semi-ring. The cross section of the thrust ball type thrust bearing raceway is a four point contact type. The left semi-ring and the right semi-ring are both provided with a corresponding arc outer raceway. Two arc inner raceways are arranged on the screw. The radius of two inner raceways is the same as that of two outer raceways. The centers of four arc raceways are in a same circumference, but four arc raceways are non-concentric. The steel ball is arranged between the screw and the ring. Four contact points are formed between the steel ball and two outer raceways and two inner raceways, and thus a four point contact type thrust ball bearing is formed. In assembly, a punching-riveting anti-loosening structure is adopted between an adjusting nut and a valve body. For the bearing, a screw is used to replace a shaft washer, a holder is not needed any more, and the installation becomes convenient. The inner raceway and outer raceway are both composed of two arcs, a four point contact ball bearing is formed and is capable of bearing a large axial / radial force, the wear is reduced, and the service life is prolonged.

A rack shaft support device includes: a rack shaft support member that is accommodated inside a retention hole formed in a housing so as to slide in an axial direction of the retention hole, and slidably supports a rack shaft; a sealing member fixed to an inlet port of the retention hole; an intermediate member that is interposed between the rack shaft support member and the sealing member; a torsion spring that couples the sealing member and the intermediate member; a cam mechanism that converts a rotational force of the intermediate member induced by untwisting of the torsion spring to a force by which the intermediate member pushes the rack shaft support member; an opposing portion that opposes a rear surface of the rack shaft support member; and an annular elastic member that is interposed between the rear surface of the rack shaft support member and the opposing portion.

An electrically powered steering apparatus in which at least one torque selected from a steering torque and a motor torque is transmitted from a torque transmission shaft to a rack-and-pinion mechanism to steer steered wheels. The torque transmission shaft has a torque-side shaft provided with a magnetostrictive film of a magnetostrictive sensor for sensing torque; and a pinion shaft provided with a pinion of the rack-and-pinion mechanism. The torque-side shaft and the pinion shaft are separate components which are linked together.

Disclosed is a rack-assist type electric power steering apparatus, in which when a ball nut slides a rack bar while rotating, a vibration and a noise in the axis direction and the radial direction, generated from the rack bar and a rack housing, are absorbed. This facilitates the operation of the ball nut and the rack bar, and reduces the vibration and the noise, thereby resulting in an effect for providing a comfortable steering feeling to a driver.

The circular ball type electric booster steering device has, except screw, nut, gear sector, steel ball and other mechanical parts, torque sensor, boosting motor, decelerating mechanism, electronic controller unit, etc. The electronic controller unit determines the target current of the motor based on the steering disc torque and the vehicle speed to complete the feedback tracking control of the motor current. The decelerating mechanism has input connected to the motor and output connected to the screw or gear sector shaft in the circular ball steering unit. The present invention has saving in energy, provides proper power force fitting different running conditions, and has less parts, light weight, compact structure and high automation.

A ball joint (10) includes a socket (40) with a housing (42) and a stem portion (44). The housing (42) defines a chamber (60). A ball stud (80) has a ball portion (82) in the chamber (60) and a stud portion (84) extending from the ball portion. The ball portion (82) has a center (90) and the stud portion (84) has an axis (86) intersecting the center. The ball portion (82) has an equator (92) extending perpendicular to the axis (86) and dividing the ball portion into first and second hemispheres (94, 96). First and second bearings (110, 120) are located in the chamber (60) and engage the first and second hemispheres (94, 96), respectively, of the ball portion (82). First and second dampers (130, 132) act between the socket (40) and the respective first and second bearings (110, 120) and bias the first and second bearings toward the equator (92) and provide first and second clearances (131, 133), respectively, between the socket (40) and the first and second bearings.

A control system with slow-in-turn capabilities for use with a self-propelled, steerable vehicle, such as a lawn mower, is disclosed. In one embodiment, the system slows the vehicle speed when turns are made beyond a predetermined range and the speed is at or above a predetermined level, as determined by a speed control device operatively connected to the speed control structure of a motive device by a speed control linkage. This slowing results in increased traction for achieving tighter turns and also improves dynamic stability. Two different types of rack-and-pinion steering systems capable of being used with the control system are also disclosed.

Disclosed is a worm wheel of a reducer of an electric power steering apparatus which is manufactured by integrally injection-molding a hub, a boss, and a gear forming part, thereby making it possible to increase a forming performance of the worm wheel and reduce an amount of material, and increasing a mechanical durability and frictional characteristics of the worm wheel to allow the reducer to be stably used for a long time, and a method for manufacturing the same.

A control device for an electric power steering apparatus, which controls a motor based upon a steering assist instruction value calculated in a steering assist instruction calculating section based upon a steering torque generated in a steering shaft and a current control value calculated from a current value of the motor for applying a steering assist force to a steering mechanism, and has a gain curve of characteristics of the entire control system having the steering assist instruction value as its input, which at least partially possesses a gradient exceeding a predetermined value, and in this arrangement, the steering assist instruction value calculating unit is composed of an approximation functional expression in which at least one-step derived functions are continuous, and the steering assist instruction value is found through calculations based upon the approximation functional expression. It is possible to provide a control device which can achieve a continuous, pleasant sense of steering by providing the steering assist instruction value as a continuous function.

Disclosed is a reducer of an electric power steering apparatus, which can prevent the steering feeling of a driver, and the performance from being reduced by minimizing an increase in the torque, caused by moisture absorption of a worm wheel, and a size change due to the moisture absorption, and also can eliminate the playing caused by wearing of a worm and the worm wheel, and inhibit the occurring of a rattle noise caused by a backlash and a reversely input load.

A vehicle comprises a vehicle frame, a prime mover mounted on the vehicle frame, a laterally turnable wheel disposed at one side of the vehicle frame, a pair of drive wheels disposed at the other side of the vehicle frame, a steering operation device, a traveling operation device for setting the traveling speed and direction of the vehicle, and a pair of transmissions for controlling the rotary speed and direction of the respective drive wheels. The transmissions are operationally connected with the steering operation device so as to create a difference of rotary speed between the drive wheels according to operation of the steering operation device. The transmissions are operationally connected with the traveling operation device so as to drive the drive wheels in a common rotary direction from their stationary state according to operation of the traveling operation device. A clutch is interposed between the transmissions so as to connect the drive wheels with each other when the steering operation device is set in a straight traveling position. Based on setting of a switching device for switching the traveling direction of the vehicle between forward and rearward, a reverser decides the rotational direction of the drive wheels.

A motor operated power steering device which transmits rotational force from a steering assistance motor to a steering shaft by way of a gear fitted around the outer circumference of the steering shaft. A torque limiter fitted in between the steering shaft and the gear comprises a torque setting member, which is subject to diametric deformation as a result of being fitted in between the outer circumference of the steering shaft and the inner circumference of the gear. Diametric force is applied to the steering shaft and the gear in accordance with the diametric deformation of the torque setting member. The limit torque value of the torque limiter corresponds to the diametric deformation of the torque setting member.

A rack shaft is supported at three positions including a gear housing receiving an engagement portion between a rack gear and a pinion near one end in an axial direction with respect to a rack housing corresponding to a support body thereof, a housing near the other end, and a hollow tube housing in an approximately center portion of the rack shaft. A bush made of a resin and constituted by a cylinder body is used for supporting the rack shaft by the hollow tube housing in the approximately center portion of the rack shaft. The bush is provided with a plurality of cut grooves extending in an axial direction thereof, and is provided with a curve forming portion substantially supporting the rack shaft and extending toward an inner side in a center portion in the axial direction thereof.

A method for producing a rack bar for a steering mechanism in an automobile. A blank pipe is held in a die, which has, at its inner surface, linear tooted portions. Mandrels are inserted repeatedly to the blank pipe while the direction of the insertion is alternately changed, while the insertion of the mandrel on one side of the blank pipe and the withdrawal of the mandrel on the other side are overlapped. Furthermore, lubrication is controlled so that an increased temperature of the work around 200° C. as generated under the plastic deformation of the metal is kept. An increased efficiency as well as reduced cost are obtained.

An off-road vehicle has a frame with a floorboard extending laterally over a middle region of the frame. The floorboard has a upward projection that defines a tunnel. At least a portion of an air intake system of an engine of the vehicle is positioned within the tunnel. A foot pedal is disposed in front of a seat such that a driver of the vehicle can operate the pedal by foot. The tunnel has a surface that is laterally adjacent the foot pedal such that the foot of a driver can simultaneously contact the surface and the foot pedal.

An electric power steering apparatus (10) includes a steering wheel (21), a steering shaft (22), a rack-and-pinion mechanism (25), and a rack shaft (26) connected to the steering wheel through the steering shaft and the rack-and-pinion mechanism. The rack shaft is connected to vehicle wheels (29, 29). The electric power steering apparatus further includes a first electric motor (41) for producing a motive power to be applied to the steering shaft, and a second electric motor (51) for producing a motive power to be applied to the rack shaft.

The application discloses a rack end protection method of an electric power steering system. When a rack of a steering gear moves towards the end of the rack and enters a rack end protection area, an ECU (electronic control unit) of the electric power steering system takes a rotating angle of a steering wheel, the speed of the rotating angle and rotating torque as input to calculate a rack end protection gain value which serves as a multiplier during assisting torque calculation. The rack end protection gain value is the product of a basic gain coefficient, a rotating speed gain coefficient and a rotating torque gain coefficient. The basic gain coefficient decreases progressively as the absolute value of the rotating angle of the steering wheel increases. The rotating speed gain coefficient decreases progressively as the absolute value of the rotating angle of the steering wheel increases. The rotating torque gain coefficient increases progressively as the absolute value of the rotating angle of the steering wheel increases. According to the rack end protection method of the electric power steering system, during working conditions of rack ends, current output can be limited, temperature rise can be reduced and mechanical impact of the rack ends can be avoided.

A control system with slow-in-turn capabilities for use with a self-propelled, steerable vehicle, such as a lawn mower, is disclosed. In one embodiment, the system slows the vehicle speed when turns are made beyond a predetermined range and the speed is at or above a predetermined level, as determined by a speed control device operatively connected to the speed control structure of a motive device by a speed control linkage. This slowing results in increased traction for achieving tighter turns and also improves dynamic stability. Two different types of rack-and-pinion steering systems capable of being used with the control system are also disclosed.

A rack and pinion steering gear assembly including a housing, a rack that is translatably moveable relative to the housing along an axis and a bushing operably disposed between the rack and housing. The bushing defines a gap which extends the entire axial length of the bushing. At least one compressible member may be disposed between the bushing and the housing with the compressible member extending across the gap in the bushing and fully encircling the bushing. The bushing may also include a radial flange that acts as a travel stop. The bushing may also be formed of an acetal material wherein the flange and a tubular portion of the bushing are axially separated by an intermediate portion having a relatively thin radial thickness. Axially extending recesses may be provided to enhance the flexibility of the bushing.

A control device which: controls a motor based upon a steering assist instruction value calculated in a steering assist command operating section based upon a steering torque generated in a steering shaft and a current control value calculated from a current value of the motor for applying a steering assist force to a steering mechanism; and at least partially possesses a gradient when a gain curve of characteristics of an entire control system having the steering assist command value as its input exceeds a predetermined value. The steering assist command value operating section is composed of an approximation functional expression in which a one-step derived function is continuous, and the steering assist command value is obtained by calculations based upon the approximation functional expression.

A gear for vehicle steering systems, in which, by pivoting a shaft of a pinion in the radial direction by means of a spring element, play-free transmission of the rotary motion from the shaft to a power takeoff shaft is assured.

The invention relates to a steering system and an independent suspension wheel type overload vehicle. The steering system comprises a steering mechanism and a steering hydraulic power assisted system, wherein the steering mechanism is used for providing steering force for wheels; the steering hydraulic power assisted system is used for providing the wheels with steering assisted power for overcoming the steering resisting moment from the ground. As the steering mechanism is used for providing the steering force for the wheels and the steering hydraulic power assisted system is used for providing the wheels with the steering assisted power for overcoming the steering resisting moment from the ground, compared with a steering system only depending on torque output by a steering gear or only depending on torque output by the steering gear and a steering power assisted follower, the steering system can effectively overcome the steering resisting moment from the ground, and the vehicle can have the steering capacity at various sites.

A rack (1) and pinion (4) steering gear for a vehicle in which the steering angle ratio varies as a function of at least both the steering wheel angle input by the driver and vehicle speed. The steering gear comprising a rack (1) laterally displacable with respect to a steering gear housing and a pinion (4) laterally movable within the housing substantially in a direction of travel of the rack (1) whilst engaged with the rack (1). The steering angle ratio is increased in a central region of travel of the rack (1) when compared to regions either side thereof, and steering angle ratio is further increased in the central region as vehicle speed increases.