Mikuni Corporation

Norio Takehana

Takehiko Naiki

Hideaki Kusanagi

Noriaki Chiba

Shin Saito

Makoto Shichi

Yuichi Mikami

Atsushi Sugawara

Hideki Imamatsu

The disclosure provides a pump device capable of suppressing hydraulic amplitude and reducing noise or vibration associated with hydraulic amplitude while simplifying the structure. The pump device includes: a housing which defines a suction port, a discharge port, and an accommodation chamber; and a pump unit which is arranged in the accommodation chamber and which defines a pump chamber that expands and contracts to exert a pumping action including a suction stroke and a pressurization and discharge stroke on a fluid. The housing includes an air introduction hole that is opened to introduce air into the pump chamber at a predetermined opening timing immediately before the suction stroke is completed.

Pump device with air introduction hole that opens into pump chamber at predetermined opening time immediately before suction stroke

Provided are an impeller and a centrifugal pump that can be simplified in structure and reduced in weight and cost, and that can be integrally molded by a mold or the like. In a centrifugal pump including a housing having an inlet, an outlet and an impeller chamber, an impeller is disposed in the impeller chamber and is rotationally driven by a driving shaft. The impeller includes: a shaft part connected to the driving shaft to rotate about an axis line extending toward the inlet; blades protruding radially outward from an outer periphery of the shaft part; and an annular shroud plate continuous with the blades so as to cover a tip side area of the blades in order to be disposed adjacent to an inner wall of the housing on the inlet side.

Impeller and centrifugal pump

A check valve for opening/closing intake-side communication passages through which fuel passes, includes a pump body including a partition wall with the communication passages formed therein, a valve body supported by the partition wall, made of a flexible material, and formed into a plate shape, and a valve seat provided around opening portions of the communication passages on the partition wall and including a seat surface to abut against the valve body when the valve is closed, the seat surface including a groove having an opening-portion-side wall surface lying on an upstream side and an outer-side wall surface lying on a downstream side, the upstream and downstream sides being sides in a direction in which fluid passes between the valve body and the seat surface when the valve is opened, the outer-side wall surface having a gentler slope than a slope of the opening-portion-side wall surface.

Valve device

Provided is a hydraulic circuit for transmissions with which, while suppressing the hydraulic circuit from becoming complicated, it is possible to suppress an operational failure and a drop in the oil pressure of the hydraulic circuit, and to stabilize an oil pressure in the hydraulic circuit. The CVTincludes a part to be lubricated and a hydraulic control part for controlling transmission. The hydraulic circuit for transmissions includes a hydraulic oil pathwayfor supplying oil from the pump apparatusto the hydraulic control part, and a lubricating oil pathwayfor supplying oil containing an air bubble to the part to be lubricated. The pump apparatusincludes a multi-stage trochoid pumpand has an air bubble-containing oil discharging partfor discharging the oil containing an air bubble to the first stage trochoid pump part. The air bubble-containing oil discharging partis connected to the lubricating oil pathway. The second stage trochoid pump partincreases pressure of the oil discharged from the first stage trochoid pump part, and discharges it from the high-pressure oil discharging part. The hydraulic oil pathwayis connected to the high-pressure oil discharging part

Hydraulic circuit for transmissions

A valve apparatus is small, and regulates a fuel amount by restricting a lift amount of a valve. A columnar portion is formed on a pump body. The columnar portion is inserted into a check valve and a washer formed with a protruding portion which protrudes outward from a flange portion, and the check valve and washer are attached or fixed to the pump body by subjecting a tip end of the columnar portion to thermal caulking or the like. An outer diameter of the protruding portion is set to be relatively smaller than an outer diameter of the flange portion such that when the check valve is sandwiched between the protruding portion and pump body, the check valve contacts an outer peripheral edge of the flange portion when the check valve opens. As a result, a lift amount of the valve can be restricted, and a flow rate of fuel passing through a passage can be maintained at a constant level.

Valve apparatus

A water pump includes an engage mechanismwhich is disposed between a pump bodyand the end portion of a pump shaftopposite to the side where an impelleris attached, while engaging the pump shaft to the pump body against the urging force of the urging member which urges a mechanical seal. The engage mechanism includes an annular memberwhich is rotatably fitted to the pump shaftwhile contacting the pump body, and a cylindrical engage pinwhich pierces the pump shaftin the diameter direction while sandwiching the annular memberwith the pump body

Growing community of inventors

Iwate, Japan

Norio Takehana