A steering device includes: a steering mechanism including a steering shaft, and a transmitting mechanism; and a controller including a first hydraulic passage state judging section, a first electric motor control section, and a second electric motor control section; the first hydraulic passage state judging section configured to judge a state of the hydraulic fluid in a first hydraulic passage in which the hydraulic fluid discharged from the first pump flows, the first electric motor control section configured to control and drive the first electric motor based on a driving state of a vehicle, and the second electric motor control section configured to increase a rotation number of the second electric motor when the first hydraulic passage state judging section judges that a supply of the hydraulic fluid in the first hydraulic passage is deficient.

A steering device includes: a steering mechanism including a steering shaft, and a transmitting mechanism; and a controller including a first hydraulic passage state judging section, a first electric motor control section, and a second electric motor control section; the first hydraulic passage state judging section configured to judge a state of the hydraulic fluid in a first hydraulic passage in which the hydraulic fluid discharged from the first pump flows, the first electric motor control section configured to control and drive the first electric motor based on a driving state of a vehicle, and the second electric motor control section configured to increase a rotation number of the second electric motor when the first hydraulic passage state judging section judges that a supply of the hydraulic fluid in the first hydraulic passage is deficient.

Technical solutions for compensating for lash in a steering system are described. An example method includes determining a rack pressure value based on a driver torque value and a differential pressure across a rack of the steering system. The method also includes determining a compensation friction value based on a position of a handwheel of the steering system and a speed of a vehicle equipped with the steering system. The method also includes computing a pressure value based on the rack pressure value and the compensation friction value. The method also includes generating a torque command using the pressure value, the torque command being added to the driver assist torque for the steering system.

This power steering valve (1) includes a sleeve (40), a spool (60) held in such a way as to be able to rotate within the housing (40), to which an input shaft U of a steering wheel S is coupled, a gerotor (30) fixed to the sleeve (10) and configured to be driven by hydraulic fluid which flows out from the predetermined opening of the sleeve (40), and a drive shaft (80) meshing with an inner rotor (32) of the gerotor (30) and pivotally supported in a swingable manner by the sleeve (40) with use of a pin (81), wherein an overall length Ld of the drive shaft (80) is formed to have a dimension defined by (¼).Math.Ls≤Ld≤(½).Math.Ls relative to an overall length Ls of the sleeve (40), and the pin (81) is arranged at a position nearer the gerotor (30) in an axial direction than a middle position in the sleeve (40).

This power steering valve (1) includes a sleeve (40), a spool (60) held in such a way as to be able to rotate within the housing (40), to which an input shaft U of a steering wheel S is coupled, a gerotor (30) fixed to the sleeve (10) and configured to be driven by hydraulic fluid which flows out from the predetermined opening of the sleeve (40), and a drive shaft (80) meshing with an inner rotor (32) of the gerotor (30) and pivotally supported in a swingable manner by the sleeve (40) with use of a pin (81), wherein an overall length Ld of the drive shaft (80) is formed to have a dimension defined by (¼).Math.Ls≤Ld≤(½).Math.Ls relative to an overall length Ls of the sleeve (40), and the pin (81) is arranged at a position nearer the gerotor (30) in an axial direction than a middle position in the sleeve (40).

A steering gear assembly, which utilizes a manually-drive first rotatable input shaft coupled with a rotatable valve member to control flow of hydraulic fluid to different downstream passages, includes a torsion tube and a transfer shaft extending within the interior of the torsion tube, with the transfer shaft being configured to receive rotational force from a second rotatable input shaft coupled to a motor or another mechanical torque-supplying element. The torsion tube applies a rotational restoring force to the rotatable valve member. A removable end cover for a steering gear assembly housing includes a rotary seal permitting rotation of the transfer shaft and/or second rotatable input shaft, with the first and second rotatable input shafts opposing one another. A remanufacturing kit for a steering gear assembly includes a torsion tube, a transfer shaft, and an end cover as mentioned. A method for remanufacturing a steering gear assembly is further provided.

A steering gear assembly, which utilizes a manually-drive first rotatable input shaft coupled with a rotatable valve member to control flow of hydraulic fluid to different downstream passages, includes a torsion tube and a transfer shaft extending within the interior of the torsion tube, with the transfer shaft being configured to receive rotational force from a second rotatable input shaft coupled to a motor or another mechanical torque-supplying element. The torsion tube applies a rotational restoring force to the rotatable valve member. A removable end cover for a steering gear assembly housing includes a rotary seal permitting rotation of the transfer shaft and/or second rotatable input shaft, with the first and second rotatable input shafts opposing one another. A remanufacturing kit for a steering gear assembly includes a torsion tube, a transfer shaft, and an end cover as mentioned. A method for remanufacturing a steering gear assembly is further provided.

A quick response steering system with a steering device that steers a vehicle. An electro-hydraulic steering circuit couples to the steering device. The electro-hydraulic steering circuit includes a load sensing pump that pumps hydraulic fluid to a steering cylinder. The load sensing pump increases or decreases output from the load sensing pump in response to a pressure differential between a first fluid line and a second fluid line. A precharge valve diverts hydraulic fluid from the first fluid line to the second fluid line. A controller couples to the steering device and the precharge valve. The controller opens the precharge valve in response to input from the steering device to change a first pressure of the first fluid line to increase an output of the load sensing pump.

A quick response steering system with a steering device that steers a vehicle. An electro-hydraulic steering circuit couples to the steering device. The electro-hydraulic steering circuit includes a load sensing pump that pumps hydraulic fluid to a steering cylinder. The load sensing pump increases or decreases output from the load sensing pump in response to a pressure differential between a first fluid line and a second fluid line. A precharge valve diverts hydraulic fluid from the first fluid line to the second fluid line. A controller couples to the steering device and the precharge valve. The controller opens the precharge valve in response to input from the steering device to change a first pressure of the first fluid line to increase an output of the load sensing pump.

A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, left and right working ports connected to left and right working flow paths, respectively, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path. A variable diagonal orifice is connected to the main flow path and to the tank flow path. The bridge arrangement orifices being closed in neutral position and the diagonal orifice being open in neutral position.