Toyoda Koki Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Ryutaro Abe

Yoshiyuki Takeuchi

Mikio Suzuki

Kyosuke Haga

Akio Numazawa

Yoshiharu Inaguma

Susumu Honaga

Minoru Kawabata

Tadataka Narumi

Yoshiyuki Toyama

Tomomi Nakayama

Michihiro Kitamura

Kouichi Shibata

Shookichi Shiozawa

A vane pump includes a pump housing formed with a cylindrical inner space, intake ports and exhaust ports, a rotating shaft rotatably supported by the pump housing, a rotor received in the cylindrical inner space to be rotated by the rotating shaft, a cam ring disposed in the cylindrical inner space, a plurality of vanes held by the rotor to define plural pump chambers between the rotor and cam ring. Fluid sucked from the intake ports is pressurized and discharged to the exhaust ports. The vane pump is further provided with first and second pressure chambers and a throttle passage connecting the first and second pressure chambers. Pressurized fluid discharged from one of the exhaust ports is led to one of the two pressure chambers and pressurized fluid discharged form the other of the exhaust ports is led to the other of the pressure chambers while pressurized fluid is taken out from the second pressure chamber to be supplied to a fluid device.

Vane pump with pressure chambers at the outlet to reduce noise

A reservoir used in an automotive power steering system is provided with a first filter disposed within a reservoir body at a location between an inlet and an outlet thereof. The reservoir is further provided with a first guide member for forcing the oil flowed into through the inlet to flow toward the first filter by changing the flow direction of the oil and a second guide member for forcing the oil passed through the first filter to flow toward the outlet by changing the flow direction of the oil. The first guide member is provided with an opening, and a second filter whose mesh is finer than that of the first filter is attached to the opening so as to allow the oil to flow from the inlet to the inside space above the first filter through the second filter. On the other hand, the second guide member is formed with a second opening for allowing the oil passed through the first filter to flow toward the outlet through the second opening.

Reservoir

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 vane type hydraulic pump for use in a power steering apparatus comprising a pump housing receiving therein a non-rotatable cam ring and first and second non-rotatable but axially slidable side plates. A pump rotor rotatable integrally with a drive shaft is received in an internal cam bore of the cam ring and, when rotated, delivers pressurized fluid to a discharge port connected to the power steering apparatus. The first and second side plates define at a contact portion therebetween a radial low pressure cavity, which is fluidically communicated with an axial low pressure hole receiving working fluid from a pump reservoir and bypassed fluid from a flow volume control valve. A branch member is provided on one of the side plates to smoothly branch the fluid flow flowing in the low pressure hole in the axial direction into the flow flowing along the low pressure cavity in the radial direction.

Hydraulic pump for power steering

A power steering apparatus comprises a main valve member rotating in response to the action of a fluid pressure motor supplementing manual steering torque and a flap valve member rotating in response to the manual steering torque and mounted within the main valve member. The main valve member and the flap valve member are operable to control flow of fluid under pressure supplied into and discharged from the fluid pressure motor. A plunger member is slidably received in the flap valve member and is provided with an anti-vibration member. A passage communicating with a fluid supply port is provided for applying fluid under pressure to the plunger member to urge the anti-vibration member against the main valve member.

Power steering apparatus

Growing community of inventors

Toyokawa, Japan

Ryutaro Abe