Abstract: A method for controlling a steering apparatus (10) of a vehicle includes providing a steering signal (154) indicative of a steering maneuver to be performed. A desired parameter of the steering apparatus is calculated during the steering maneuver when no external force is applied to a hand wheel (14) of the vehicle. The parameter is measured during the steering maneuver. A mode signal (182) is produced by comprising the desired parameter to the parameter. The vehicle is placed in one of an autonomous driving mode and a manual driving mode based on the mode signal (182).

Abstract: An apparatus includes a hydraulic power steering motor. A continuously variable transmission has an input shaft rotatable under the influence of force transmitted from the engine and an output shaft operable to drive a pump. The continuously variable transmission is operable to drive the pump at a first speed when one of the input and output shafts of the continuously variable transmission rotates at a first speed. The continuously variable transmission is operable to drive the pump at a second speed when the one of the input and output shafts rotates at a second speed. A centrifugal sensor is connected with the one of the input and output shafts. The centrifugal sensor transfers rotational movement of the one of the input and output shafts to a linearly displaceable input member of the continuously variable transmission to change the speed at which the pump is driven.

Abstract: An apparatus includes a hydraulic power steering motor. A continuously variable transmission has an input shaft rotatable under the influence of force transmitted from the engine and an output shaft operable to drive a pump. The continuously variable transmission is operable to drive the pump at a first speed when one of the input and output shafts of the continuously variable transmission rotates at a first speed. The continuously variable transmission is operable to drive the pump at a second speed when the one of the input and output shafts rotates at a second speed. A centrifugal sensor is connected with the one of the input and output shafts. The centrifugal sensor transfers rotational movement of the one of the input and output shafts to a linearly displaceable input member of the continuously variable transmission to change the speed at which the pump is driven.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (14, 16) includes a hydraulic power steering motor (12). A pump (26) having an outlet port (28) is connected in fluid communication with the power steering motor (12) and operable to supply hydraulic fluid to the power steering motor (12). A continuously variable transmission (50) is connected with the engine of the vehicle and the pump (26). The continuously variable transmission (50) is operable to drive the pump (26) at a first speed when the pressure at the outlet port (28) is at a first pressure. The continuously variable transmission (50) is operable to drive the pump (26) at a second speed when the pressure at the outlet port (28) is at a second pressure different than the first pressure. The first speed at which the pump (26) is driven is greater than the second speed.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (14, 16) includes a hydraulic power steering motor (12). A pump (26) having an outlet port (28) is connected in fluid communication with the power steering motor (12) and operable to supply hydraulic fluid to the power steering motor (12). A continuously variable transmission (50) is connected with the engine of the vehicle and the pump (26). The continuously variable transmission (50) is operable to drive the pump (26) at a first speed when the pressure at the outlet port (28) is at a first pressure. The continuously variable transmission (50) is operable to drive the pump (26) at a second speed when the pressure at the outlet port (28) is at a second pressure different than the first pressure. The first speed at which the pump (26) is driven is greater than the second speed.

Abstract: A method for controlling a steering apparatus (10) of a vehicle produces an error signal (128) by subtracting a hand wheel torque (118) and a column torque (126) from a desired operator torque (112) to be applied to a hand wheel (14) of the vehicle. A controller (102) receives at least one vehicle condition signal (106, 108, 110) and determines the desired operator torque (112). The desired operator torque (112) is filtered into a low frequency torque component (112a) and a high frequency torque component (112b). The steering apparatus (10) is controlled based on the low frequency torque component (112a) and the high frequency torque component (112b).

Abstract: A steering apparatus (10) responsive to rotation of a handwheel (40) for turning steerable wheels (14, 16) includes a first steering gear (22) actuatable to affect turning of a first set (14) of steerable wheels (14a, 14b) and a second steering gear (24) actuatable to affect turning of a second set (16) of steerable wheels (16a, 16b). A torque transmission device (70) includes an input member (72) connected to the handwheel (40). A first output member (82) is mechanically coupled to the input member (72) and connected to the first steering gear (22) for actuating the first steering gear (22). A second output member (92) is mechanically coupled to the input member (72) and connected to the second steering gear (24) for actuating the second steering gear (24).

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 improved apparatus (30) for steering rear wheels (16, 18) of a vehicle (10) includes hydraulic motor (34) having chambers (56, 58) which hold hydraulic fluid. An increase in fluid pressure in one of the chambers turns the steerable rear wheels of the vehicle in a first direction. An increase in fluid pressure in another one of the chambers turns the steerable rear wheels in a second direction. A control valve (36) is connected in fluid communication with the chambers (56, 58) of the hydraulic motor. The control valve (36) is free of a return flow of hydraulic fluid from the motor (34). A return conduit (134) is connected with the chambers (56, 58) and conducts a flow of hydraulic fluid to a reservoir (116) along a path which is spaced from the control valve (36). The motor (34) may include springs (70, 72) which are disposed in the chambers (56, 58) of the motor. Biasing sleeves (76, 78) are effective to transmit force from the springs to a piston (62).

Abstract: An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. An engine driven pump connected with the power steering motor assembly is driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly. A controller increases engine speed when the vehicle is motionless and a steering wheel is rotated. A method for controlling the speed of an engine to provide a predetermined steering assist to a steering apparatus includes determining if the vehicle is motionless and determining if the steering wheel is being rotated. The speed of the engine is increased if the vehicle is motionless and the steering wheel is being rotated to provide the predetermined steering assist to the steering apparatus.

Abstract: An improved apparatus (30) for steering rear wheels (16, 18) of a vehicle (10) includes hydraulic motor (34) having chambers (56, 58) which hold hydraulic fluid. An increase in fluid pressure in one of the chambers turns the steerable rear wheels of the vehicle in a first direction. An increase in fluid pressure in another one of the chambers turns the steerable rear wheels in a second direction. A control valve (36) is connected in fluid communication with the chambers (56, 58) of the hydraulic motor. The control valve (36) is free of a return flow of hydraulic fluid from the motor (34). A return conduit (134) is connected with the chambers (56, 58) and conducts a flow of hydraulic fluid to a reservoir (116) along a path which is spaced from the control valve (36). The motor (34) may include springs (70, 72) which are disposed in the chambers (56, 58) of the motor. Biasing sleeves (76, 78) are effective to transmit force from the springs to a piston (62).

Abstract: A steering apparatus (10) for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel (12) comprises a first assembly (16), a second assembly (26), and a mechanism (108). The first assembly is operatively coupled to the steering wheel and includes components (18, 22) for monitoring applied torque and angular rotation of the steering wheel. The second assembly includes a steering gear (34) and components (28, 30) for actuating the steering gear in response to the monitored rotation. The mechanism, when in a first mode of operation provides a mechanical connection between the steering wheel and the steering gear. The mechanism when in the second mode of operation, providing a mechanical connection between the steering wheel and the steering gear sufficient to enable manual actuation of the steering gear and permit actuation of the steering gear in response to the monitored steering wheel rotation.

Abstract: A method for controlling a steering apparatus (10) of a vehicle includes providing a steering signal (154) indicative of a steering maneuver to be performed. A desired parameter of the steering apparatus is calculated during the steering maneuver when no external force is applied to a hand wheel (14) of the vehicle. The parameter is measured during the steering maneuver. A mode signal (182) is produced by comprising the desired parameter to the parameter. The vehicle is placed in one of an autonomous driving mode and a manual driving mode based on the mode signal (182).

Abstract: The present invention relates to an apparatus (10) for helping to turn steerable wheels (15) of a vehicle. The apparatus includes a hydraulic power-assisted steering gear (130), a fluid source (20) for supplying the steering gear (130) with hydraulic fluid, and a controller (52) for controlling the fluid source. The steering gear (130) includes a closed center valve (150) operatively connected with a vehicle steering wheel (12) and in fluid communication with the fluid source. The controller (52) is responsive to the pressure of the hydraulic fluid for controlling the fluid source (20) to supply the steering gear (130) with hydraulic fluid at a first predetermined pressure when the vehicle is in a first condition. The controller (52) is responsive to the pressure of the hydraulic fluid for controlling the fluid source (20) to supply the steering gear (130) with hydraulic fluid at a second predetermined pressure when the vehicle is in a second condition.

Abstract: An apparatus for use in turning steerable vehicle wheels upon manual rotation of a hand wheel includes a torque sensor connected with the hand wheel. A controller is connected with the torque sensor and a rear steering gear. The controller is operable to effect operation of the rear steering gear in response to an output from the torque sensor upon manual application of at least a predetermined torque to the hand wheel. The torque sensor has an output which corresponds to a torque which is less than the predetermined torque throughout turning of the front wheels through a first range of turning movement. The torque sensor has an output which corresponds to a torque which is at least as great as the predetermined torque which occurs when turning of the front wheels during a second range of turning movement of the front wheels.

Abstract: An apparatus (10) for turning steerable wheels (12, 14) of a vehicle in response to turning of a steering wheel (18) of the vehicle. The apparatus includes a hydraulic power steering gear, which does not include a rotary valve responsive to a steering input generated by turning of a steering wheel (18). The hydraulic steering gear includes a first chamber (96) for holding hydraulic fluid and a second chamber (98) for holding hydraulic fluid. An increase in fluid pressure in one chamber acts to turn the steerable wheels (12, 14) of the vehicle in one direction and an increase in fluid pressure in the other chamber acts to turn the steerable wheels (12, 14) in a direction opposite the one direction. The apparatus (10) includes a variable flow mechanism (50) for supplying a flow of hydraulic fluid to the first and second chambers (96, 98), which flow varies in dependence upon at least one sensed vehicle condition.

Abstract: A steering apparatus (10) for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel (12) comprises a first assembly (16), a second assembly (26), and a mechanism (108). The first assembly is operatively coupled to the steering wheel and includes components (18, 22) for monitoring applied torque and angular rotation of the steering wheel. The second assembly includes a steering gear (34) and components (28, 30) for actuating the steering gear in response to the monitored rotation. The mechanism, when in a first mode of operation provides a mechanical connection between the steering wheel and the steering gear. The mechanism when in the second mode of operation, providing a mechanical connection between the steering wheel and the steering gear sufficient to enable manual actuation of the steering gear and permit actuation of the steering gear in response to the monitored steering wheel rotation.

Abstract: A power steering apparatus (10) includes a first pump (24) which is continuously driven to supply fluid under pressure to a power steering motor assembly (18). A second pump (32) is driven by the engine (30) of the vehicle when a predetermined vehicle operating condition occurs. The predetermined vehicle operating condition may, if desired, be operation of the engine (30) of a vehicle at a speed which is less than a predetermined speed. A flow control valve (40) directs fluid flow from the first and second pumps to the power steering motor assembly (18) during operation of both pumps. A diverter valve (62) directs fluid from the first pump (24) along a fluid flow path which is spaced from the flow control valve (40) during operation of only the first pump. The first pump (24) may, if desired, be smaller than the second pump (32).

Abstract: An apparatus (10) for turning steerable wheels (28, 124) of a vehicle (12) in response to input to a driver control interface (14) includes a sensor (18) for monitoring steering input to the driver control interface (14) and for providing a steering input signal indicative of the monitored steering input. Front and rear steering systems (24, 110 and 120, 126) are actuatable for turning front and rear sets of steerable wheels (28, 124), respectively. A controller (22), upon a malfunction of the front steering-system (24, 110), actuates only the rear steering system (120, 126) in response to the steering input signal.

Abstract: An engine driven pump 24 is connected with a power steering motor assembly 18. An electric motor 36 drives a pump 34 connected with the power steering motor assembly 18. A controller 38 effects operation of the electric motor 36 to drive the pump 34 to supply fluid to the power steering motor assembly 18 at a flow rate based on the speed of the engine 28.