Abstract: An apparatus for use in turning steerable vehicle wheels includes a steering column having a pinion connected with a vehicle steering wheel such that rotation of the steering wheel results in rotation of the pinion. An electrically powered steering unit includes an electric motor having a first output shaft rotatable about an axis. A first planetary gear stage has a first gear reduction ratio and is driven by the first output shaft. A second planetary gear stage is driven by the first planetary gear stage and the pinion and has a second gear reduction ratio different from the first gear reduction ratio. A second output shaft is driven by the second planetary gear stage and coupled to the steerable wheels such that rotation of the second output shaft affects steering of the vehicle wheels.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a steering member connected to at least one steerable vehicle wheel. The steering member moves axially to effect turning movement of the at least one steerable vehicle wheel. The steering member has an externally threaded portion. A ball nut assembly is connected with the externally threaded portion of the steering member. The ball nut assembly is rotatable relative to the steering member to axially move the steering member. A first gear member is rotatable in response to rotation of a steering wheel. A second gear member disposed in meshing engagement with the first gear member rotates in response to rotation of the first gear member. The ball nut assembly rotates relative to the steering member in response to rotation of the second gear member.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a rotatable shaft that is rotatable relative to the vehicle to effect turning movement of the steerable vehicle wheels. A ball nut assembly is connected with an externally threaded portion of the rotatable shaft. The ball nut assembly moves axially relative to the rotatable shaft upon rotation of the rotatable shaft relative to the ball nut assembly. A steering member is connected to the ball nut assembly and at least one steerable vehicle wheel. The steering member moves with the ball nut assembly relative to the shaft. An electrical motor is connected with the rotatable shaft. The motor is operable to effect rotation of the rotatable shaft relative to the ball nut assembly to turn the steerable vehicle wheels.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a steering member connected to at least one steerable vehicle wheel. The steering member moves axially to effect turning movement of the at least one steerable vehicle wheel. The steering member has an externally threaded portion. A ball nut assembly is connected with the externally threaded portion of the steering member. The ball nut assembly is rotatable relative to the steering member to axially move the steering member. A first gear member is rotatable in response to rotation of a steering wheel. A second gear member disposed in meshing engagement with the first gear member rotates in response to rotation of the first gear member. The ball nut assembly rotates relative to the steering member in response to rotation of the second gear member.

Abstract: A steering apparatus for assisting rotation of a steering shaft in a steering system. The apparatus includes a motor having a drive shaft that rotates about a drive shaft axis and an output shaft that rotates about an output shaft axis. The output shaft axis extends parallel to the drive shaft axis. The output shaft is connected for rotation with the steering shaft. A gear train drivingly connects the motor to the output shaft. The gear train includes a worm screw and a worm wheel.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a steering column having a pinion connected with a vehicle steering wheel such that rotation of the steering wheel results in rotation of the pinion. An electrically powered steering unit includes an electric motor having a first output shaft rotatable about an axis. A first planetary gear stage has a first gear reduction ratio and is driven by the first output shaft. A second planetary gear stage is driven by the first planetary gear stage and the pinion and has a second gear reduction ratio different from the first gear reduction ratio. A second output shaft is driven by the second planetary gear stage and coupled to the steerable wheels such that rotation of the second output shaft affects steering of the vehicle wheels.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a first steering member which is linearly movable relative to the vehicle to effect turning movement of the steerable vehicle wheels. A pinion is disposed in meshing engagement with a rack portion of the first steering member. A steering column is connected with the pinion and with a vehicle steering wheel such that rotation of the steering wheel results in linear movement of the first steering member. An electrically powered steering unit is connected to a second steering member extending generally parallel to the first steering member for providing steering assist to the steerable wheels.

Abstract: A steering system for turning multiple sets of steerable wheels comprises three steering gears operatively connected to the steerable wheels. Each steering gear includes a control valve assembly and has an associated hydraulic motor. The first control valve assembly directs pressurized fluid to a first hydraulic motor and also directs pressurized fluid to a second hydraulic motor. The third control valve assembly directs pressurized fluid to a third hydraulic motor. When a torque below a predetermined value is applied to an output shaft of the second steering gear, the output shaft rotates in response to movement of the first control valve assembly, and the second control valve assembly remains in a neutral condition. When a torque above the predetermined value is applied to the output shaft of the second steering gear, the output shaft rotates to cause the second control valve assembly to assume an actuated condition to direct pressurized fluid away from the second hydraulic motor.

Abstract: A steering gear clutch includes a housing and an input shaft rotatably supported by the housing. An output shaft operatively connected with a steering gear is rotatably supported by the housing. The output shaft is rotatable relative to the input shaft. The input shaft rotates together with the output shaft relative to the housing when a torque below a predetermined value is applied to the input shaft. The input shaft rotates relative to the output shaft and the housing when a torque above the predetermined value is applied to the input shaft. The input shaft may rotate relative to a shaft portion of the output shaft and the housing through a predetermined angle. The input shaft and the shaft portion may rotate together relative to the housing when the input shaft has rotated through the predetermined angle.

Abstract: A steering system for turning multiple sets of steerable wheels comprises three steering gears operatively connected to the steerable wheels. Each steering gear includes a control valve assembly and has an associated hydraulic motor. The first control valve assembly directs pressurized fluid to a first hydraulic motor and also directs pressurized fluid to a second hydraulic motor. The third control valve assembly directs pressurized fluid to a third hydraulic motor. When a torque below a predetermined value is applied to an output shaft of the second steering gear, the output shaft rotates in response to movement of the first control valve assembly, and the second control valve assembly remains in a neutral condition. When a torque above the predetermined value is applied to the output shaft of the second steering gear, the output shaft rotates to cause the second control valve assembly to assume an actuated condition to direct pressurized fluid away from the second hydraulic motor.

Abstract: A steering gear clutch includes a housing and an input shaft rotatably supported by the housing. An output shaft operatively connected with a steering gear is rotatably supported by the housing. The output shaft is rotatable relative to the input shaft. The input shaft rotates together with the output shaft relative to the housing when a torque below a predetermined value is applied to the input shaft. The input shaft rotates relative to the output shaft and the housing when a torque above the predetermined value is applied to the input shaft. The input shaft may rotate relative to a shaft portion of the output shaft and the housing through a predetermined angle. The input shaft and the shaft portion may rotate together relative to the housing when the input shaft has rotated through the predetermined angle.

Abstract: A power steering gear assembly 10 which is used to turn steerable vehicle wheels 50, 52 includes a piston 20 disposed in a motor cylinder 16. A series 44 of rack teeth are connected with the piston 20. A first tooth space 94 is formed between first and second teeth 80, 76 in the series 44 of rack teeth. The first tooth space 94 has a root portion 126 which includes first and second fillets 132, 136. The first fillet 132 has a larger radius of curvature 130 than the second fillet 136. The first and second fillets 132, 136 have centers of curvature which are both disposed between a central axis 104 of the first tooth space 94 and the second rack tooth 76. The center pinion gear tooth 190 has side surfaces 200 and 202 with intermediate portions 216 and 230 which are offset from continuously curving spatial envelopes 212 and 228 containing tip end portions 208 and 222 and root end portions 210 and 224 of the center pinion gear tooth.

Abstract: An approved apparatus (10) for turning steerable wheels (14,16) of a vehicle includes a pinion (28) which is disposed in meshing engagement with a rack portion (32) of a steering member (12). A steering column (22) is connected with a pinion (28) and with a vehicle steering wheel (20). A ball nut assembly (38) is connected with an externally threaded portion (36) of the steering member (12). A first motor (72) is connected with the steering column (22) at a location between the pinion (28) and steering wheel (20). A second motor (48) is connected with the ball nut assembly (38). A closed loop assembly (60) may be provided to control operation of the first motor (72). An open loop assembly (82) may be provided to control operation of the second motor (48).

Abstract: An approved apparatus (10) for turning steerable wheels (14,16) of a vehicle includes a pinion (28) which is disposed in meshing engagement with a rack portion (32) of a steering member (12). A steering column (22) is connected with a pinion (28) and with a vehicle steering wheel (20). A ball nut assembly (38) is connected with an externally threaded portion (36) of the steering member (12). A first motor (72) is connected with the steering column (22) at a location between the pinion (28) and steering wheel (20). A second motor (48) is connected with the ball nut assembly (38). A closed loop assembly (60) may be provided to control operation of the first motor (72). An open loop assembly (82) may be provided to control operation of the second motor (48).

Abstract: A steering system (10) for a vehicle (16) comprises a housing (20) having first and second end portions (32, 34) and an intermediate portion (50). A steering member (66) is supported for axial movement in the housing (20). A piston (100) fixed for movement with the steering member (66) has opposite end faces (104, 106). First and second springs (130, 132) engage the end faces (104, 106) of the piston (100) and bias the piston and thereby the steering member (66) in first and second axial directions toward a straight ahead position. Steering linkage (124, 126) connected with the piston member (100) transmits movement of the piston member (100) to steerable wheels (12, 14) of the vehicle.

Abstract: A steering system (10) for a vehicle (16) comprises a housing (20) having first and second end portions (32, 34) and an intermediate portion (50). A steering member (66) is supported for axial movement in the housing (20). A piston (100) fixed for movement with the steering member (66) has opposite end faces (104, 106). First and second springs (130, 132) engage the end faces (104, 106) of the piston (100) and bias the piston and thereby the steering member (66) in first and second axial directions toward a straight ahead position. Steering linkage (124, 126) connected with the piston member (100) transmits movement of the piston member (100) to steerable wheels (12, 14) of the vehicle.