Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Toyota Jidosha Kabushiki Kaisha

Susumu Honaga

Yoshiharu Inaguma

Mikio Suzuki

Osamu Watanabe

Motoyasu Yamamori

Keiichi Nakamura

Hidetoshi Fujiwara

Minoru Kawabata

Kazuhiro Watanabe

Hiroshi Kawakami

Hiroki Sato

Yoshiyuki Takeuchi

Hideya Kato

Yoshinori Suzuki

Tsune Kobayashi

Kenichi Kikuchi

Kenji Takahashi

Ryutaro Abe

Masato Tanabe

Takashi Imanishi

Yuji Yoshizawa

Nobuyuki Kawabata

Isao Hasegawa

Akihiko Sato

Tadataka Narumi

Yoshiyuki Toyama

Fumio Ukai

Hirotaka Shibata

Masanari Torii

Satoshi Sutoh

Toshihiro Gotou

A transmission ratio variable mechanism in prior art provided on a steering column needs a spiral cable and hence, not only needs an extra space but is also accompanied by a risk of having a drawback such as the breakage of the cable or the like. A steering wheel shaftand an output shaftare supported in a housingattached to a steering column, to be rotatable on the same axis; first and second sun gearsdifferent slightly in the number of gear teeth are formed on facing end portions of the steering wheel shaft and the output shaft; first and second planetary gearsmeshing with the first and second sun gears are supported on a carrier; and a worm shaftmeshing with a worm wheelconnected rotationally to the carrier is constructed to be rotatable by a motorwhich is provided on the housing in a direction perpendicular to the rotational axis of the steering wheel shaft and the output shaft. Thus, it can be realized to eliminate any spiral cable and to obtain a transmission ratio variable steering devicewhich is space-saving.

Transmission ratio variable steering device

A compact and highly reliable motor vehicle steering device that does not require a spiral flat cable. The motor vehicle steering device includes variable gear ratio system that modifies the transmission ratio of the rotary motions between first steering shaft and second steering shaft. Variable gear ratio system comprises Strain Wave Gearing Speed Reducer that modifies the transmission ratio between first steering shaft and second steering shaft in response to the rotating speed of motor shaft. Motor shaft and second steering shaft forms a substantially concentric dual structure, drive motor is affixed, and output shaft is connected to motor shaft.

Motor vehicle steering device

An electric power steering apparatus () includes a reduction mechanism (G) for transmitting the rotation of a rotating shaft () of a motor () to a ball screw nut () while reducing the speed of the rotation. The reduction mechanism includes a drive gear (), which is coaxially connected to the rotating shaft of the motor, and a driven gear (), which is arranged on the outer surface of the ball screw nut. Due to the reduction mechanism, the motor may be inclined relative to a rack shaft ().

Electronic control power steering device

The invention provides a compact and highly reliable motor vehicle steering device that does not require a spiral flat cable. The motor vehicle steering device includes variable gear ratio system that modifies the transmission ratio of the rotary motions between first steering shaft and second steering shaft. Variable gear ratio system comprises Strain Wave Gearing Speed Reducer that modifies the transmission ratio between first steering shaft and second steering shaft in response to the rotating speed of motor shaft. Motor shaft and second steering shaft forms a substantially concentric dual structure, drive motor is affixed, and output shaft is connected to motor shaft.

An electric power steering device in which a motor shaft and a rack bar form a diagonal intersection. The power transmission includes: a drive gear rotating in tandem with the motor shaft and forming a bevel gear with linearly extending teeth; a ball screw mechanism disposed co-axial with the rack bar and converting a rotational motion to a linear motion; and a driven gear rotating in tandem with a nut of the ball screw mechanism, meshing with and moving in tandem with the drive gear, and forming a bevel gear with linearly extending teeth. The drive gear and/or the driven gear can be adjusted so that backlash between the two elements can be adjusted in a continuous, non-stepped manner.

Electric power steering device

In a pump housing of a pump apparatus, a pump shaft is rotatably supported by two bearings and is connected to a pump unit. A rotary drive member is fixed to one end of the pump shaft projecting from the tip end portion of the housing. The rotary drive member includes a boss portion fixed to the one end of the pump shaft projecting from the housing, and a rim portion integral with the boss portion. The rim portion is offset from the boss portion to cover at least a portion of the tip end portion of the housing. A groove portion for receiving a drive belt is formed on the outer circumference of the rim portion. The widthwise center plane of the groove portion is located between the respective centers of the two bearings. In place of the groove portion, a tooth portion engageable with a drive gear may be formed on the outer circumference of the rim portion. Preferably, the pump unit is of a balanced vane type.

Pump apparatus having drive force input portion aligned with pump shaft bearing member

An electric power steering apparatus is composed of a wheel gear connected with a steering wheel, a worm shaft tooth-engaged with the wheel gear, and an electric motor rotatably driving the worm shaft in which a worm tooth portion of the worm shaft is formed with a compound lead. Further, the worm shaft is fixed in an axial direction by at least one locknut provided at a portion of a separate side of the electric motor. Further, one end of the worm shaft is rotatably supported through a ball bearing and is fixed by the locknut in the axial direction of the worm shaft, and the other end thereof is rotatably supported through another ball bearing or is fixed by a circlip through a disc-shaped spring in the axial direction. Furthermore, only respective outer rings of the ball bearings are further secured to a housing in which the worm shaft and the wheel gear are disposed.

Electric power steering apparatus

An oil pump apparatus, including a pump mechanism portion for discharging operating fluid, a valve-receiving bore formed in a housing, a flow control valve arranged in the valve-receiving bore connected to a bypass hole, and a bypass passage. The bypass passage is connected to the bypass hole, having a space radially extending from an edge of the bypass hole in a fluid stream direction of the excess operating fluid spouting from an opening area of the bypass hole. When fluid stream of the excess operating fluid reaches the inner surface of the bypass passage, the pressure of the excess operating fluid has been weaken sufficiently because fluid stream of the excess operating fluid is diffused by the long span of the bypass passage extended from the edged of the bypass hole. Therefore, the inner surface of the bypass passage is protected from cavitation damages and erosion.

Oil pump apparatus

A flow control device, responsive to the rotational speed of a pump and to load pressure, has a simple structure. And a housing of the flow control device for saving energy can make use of a general pump housing not for saving energy as a common housing. The flow control device of a power steering apparatus, arranged in a housing of a pump, includes a flow control valve and a load pressure responsive valve. The flow control valve includes a bypass spool with a control rod penetrating a metering orifice. The load pressure responsive valve is incorporated in a union for response to the load pressure. The control rod is located on the bypass spool for response to the rotational speed of the pump.

Flow control device of power steering apparatus

A hydraulic power steering apparatus includes a pump for discharging pressurized operation fluid, a power cylinder for generating assisting force, a control valve connected to the pump via a fluid path for receiving the operation fluid from the pump and adapted to supply the operation fluid to the power cylinder in accordance with operation of a steering wheel, a rubber hose disposed in the fluid path. A check valve is disposed between the rubber hose and the control valve. Since reverse flow of the operation fluid due to input of kick-back force is prevented, tires to be steered are prevented from undesirably steered against the driver's intention. Further, a pressure relieving mechanism is provided to relieve part of the operation fluid when the check valve operates. Therefore, the oil pressure within the power cylinder and the control valve is prevented from increasing excessively, so that the oil pressure within the pump does not reach a preset relief pressure.

Hydraulic power steering apparatus

There is disclosed a flow control apparatus for a power steering device in which an operating fluid discharged from a pump is delivered to a power steering device through a restricted passage, and the fluid flow is adjusted by a spool valve movable in response to the pressure difference across the restricted passage. The spool valve contains a first relief valve operating at a first setting pressure in response to the fluid pressure transmitted from a passage located at the downstream side of the restricted passage through a connecting passage. The spool valve also contains a second relief valve operating at a second setting pressure higher than the first setting pressure, but lower than a allowable maximum load pressure, in response to the fluid pressure directly transmitted from a chamber located at the upstream side of the restricted passage. During operations under normal temperature conditions, the first relief valve operates when the load pressure reaches the first setting pressure. Under low temperature conditions, the second relief valve first operates at the second setting pressure, and then the first relief valve operates in order to reduce the fluid pressure to the first setting pressure. With this operation, the fluid pressure delivered to the power steering device is maintained not to exceed the maximum load pressure even under low temperature condition.

Flow control apparatus for a power steering device

A power steering system which includes a fluid source that supplies pressure fluid of a constant flow rate, a fluid motor for supplementing manual steering torque, a servo-valve for distributing fluid to the fluid motor, and a reaction device for applying hydraulic reaction or feeling to a steering wheel. A magnetic control valve is connected to the reaction device to control fluid pressure applied thereto in accordance with a vehicle operating condition, such a vehicle speed. A flow dividing valve serves to divide the pressure fluid of a constant flow rate in a predetermined ratio into first and second flows which are respectively directed to the servo-valve and reaction device. A bypass conduit provided with a bypass orifice is connected between the fluid source and the servo-valve in parallel relation with the flow dividing valve.

Power steering system with hydraulic reaction

There is disclosed a hydraulic reaction mechanism which is easy to manufacture and for use with an automotive power steering system. The mechanism has an input shaft and an output shaft which are rotatable relative to each other and mounted in a housing. A servovalve is mounted between the shafts and actuated in response to the relative movement between the shafts. Radially protruding portions are formed at the end of the input shaft that is on the side of the output shaft. The output shaft has an enlarged portion provided with cylinder holes in which reaction pistons are received. The pistons hydraulically push both sides of the radially protruding portions. The pistons have grooves in which retaining plates for restricting rearward movement of the pistons are engaged.

Hydraulic reaction mechanism for power steering system

A power steering system which includes a fluid source that supplies pressure fluid of a constant flow rate, a fluid motor for supplementing manual steering torque, a servo-valve for distributing fluid to the fluid motor, and a reaction device for applying hydraulic reaction or feeling to a steering wheel. A magnetic pressure control valve is connected to the reaction device to control fluid pressure applied thereto in accordance with a vehicle operating condition, such a vehicle speed. A flow dividing valve serves to divide the pressure fluid of a constant flow rate in a predetermined ratio into first and second flows which are respectively directed to the servo-valve and reaction device. The predetermined ratio is varied such that the flow rate of the fluid supplied to the reaction device increases as the pressure of the fluid supplied to the fluid motor increases.

A power assisted steering system of the type which includes a hydraulic reaction mechanism for controlling the hydraulic power assist in accordance with an increase or decrease of the vehicle speed. The system includes primary and secondary hydraulic pumps, the primary pump having the function of applying hydraulic pressure to the power cylinder and the secondary pump having the function of applying hydraulic pressure to the reaction mechanism in proportion to the vehicle speed. The secondary pump is unitedly assembled with the primary pump to be driven by the prime mover, and comprises a first control valve for controlling the quantity of fluid applied to the reaction mechanism for the secondary pump in a constant amount, and a second control valve for controlling the pressure of fluid controlled by the first control valve in accordance with the vehicle speed.

Growing community of inventors

Hoi-gun, Japan

Susumu Honaga