Aisin Seiki Kabushiki Kaisha

Toshiro Kawakami

Masami Ishii

Noriyoshi Shibata

Makoto Okabayashi

Toru Tamura

Toshikuni Kusano

Jun Kawaguchi

A turbocharger incorporating a shaft, a turbine rotor connected to one end of the shaft and a compressor rotor connected to the other end of the shaft is disclosed. A turbine housing in which the turbine rotor rotated by exhaust gas is disposed, is provided with an involute inside wall that forms a scrolling portion for exhaust gas. A compressor housing in which the compressor rotor is disposed is also provided. A division wall divides the scrolling portion into an inside scrolling portion and an outside scrolling portion. A turbocharger has a change means for changing the flow direction of exhaust gas between an inside scrolling portion and an outside scrolling portion.

Turbocharger

A turbocharged engine includes intake passage and an exhaust passage connected with the engine, a compressor rotor of a turbocharger inserted in the intake passage, a turbine rotor of the turbocharger inserted in the exhaust passage and connected with the compressor rotor, a bypass passage connecting an upstream side of the turbine rotor and a downstream side thereof in parallel with the exhaust passage, an opening formed between the exhaust passage and the bypass passage, a first port formed at a downstream side of the compressor rotor in the intake passage and supplying a first signal pressure, a second port formed at a scroll portion of the turbocharger in the compressor rotor side and supplying a second signal pressure, a waste gate valve opening or closing the opening according to the first or second signal pressure, and a 3-way valve connecting the signal pressure chamber to the first port or second port selectively. When a revolution number of the engine is low, the 3-way valve connects the signal pressure chamber the second port and when a revolution number of the engine is high, the 3-way valve connects the signal pressure chamber to the first port.

Turbocharged engine

A centrifugal supercharger is provided with a supporting system for supporting a shaft. The supporting system includes at least one outer bearing and at least one inner bearing. The outer bearing is fitted in the housing so as to form a small clearance between its outer circumferential surface and the housing. The inner bearing is fitted in the outer bearing so as to form a small clearance between its outer circumferential surface and the inner circumferential surface of the outer bearing. In the inner bearing, the shaft is inserted so as to form a small clearance between its outer circumferential surface and the inner circumferential surface of the inner bearing. At least one outer oil supply hole and at least one inner oil supply hole are formed in the outer and inner bearings, respectively and oil is supplied from the oil supply passage to each small clearance through the oil supply holes. Thereby, an oil film is formed in each small clearance, respectively and therefore a triple oil film is formed between the shaft and the housing. Accordingly, the radial vibration of the shaft are sufficiently damped by a squeeze film effect of the triple oil film and the amount of the radial vibration which is transmitted to the housing is decreased. Thereby, the noise of the centrifugal supercharger is decreased.

Centrifugal supercharger having support bearing assembly with outer

Welding between a rotor and shaft is accomplished by first placing the shaft within a movable holder of a pressure device. The rotor is then placed in the lower or stationary holder of the pressure device. Each holder is an electrode that can electrify the shaft and rotor. The stationary holder is a cup or container which has inside the cup, a low melting point alloy which conducts electricity from the lower electrode to the rotor to prevent concentration of electricity. Welding is finished by lowering the shaft onto the rotor which is in the cup which is heated to liquefy the low melting point alloy. As the shaft and rotor are pressed together, current is passed through each by the electrodes. The junction of the shaft and rotor are melted and thus joined. After cooling, any of the low melting point metal which remains on the rotor is removed by inserting the rotor in boiling water.

Method of welding between a rotor and a shaft and a device for the method

In a Roots blower having a casing, two rotors rotatably housed within the casing, and at least two grease-enclosing bearing units to rotatably support the rotors, characterized in that a bypass groove is formed for each of the bearing unit so as to communicate between a first chamber defined by the casing and the rotors on the side of one axial end of the bearing unit and a second chamber formed by the casing and the bearing unit on the other axial side of the bearing unit, and in that a pair of pressure loaded seal rings (or lip seals) is disposed on axially opposite sides of the bearing unit in such a way that one periphery of each seat ring is secured to a stationary portion of the bearing unit and the other periphery thereof is free to move selectively into or out of contact with a movable portion of the bearing unit according to the presence or absence of a pressure difference produced by a delay in a pressure-balancing action of the bypass groove between the two chambers so that the seal ring prevents bearing grease from leaking. The seal ring is of a U- or L-shape.

Roots blower

A thrust bearing for an automobile turbocharger and which sustains a thrust load of the rotor shaft of the turbocharger. The thrust bearing has a first groove for holding lubricating oil supplied to the bearing. A first oil passage extends from the groove toward the axis of the rotor shaft. A second oil passage communicates with the first passage and has oil holes formed therein that extend to tapering lands formed on surfaces on which the rotor shaft bears. The second passage is so disposed that oil is spouted on both sides of the bearing. The lower end portion of the bearing is cut out portion to facilitate removal of oil. The cut out portion constitutes a planar portion of a closed loop on a surface of the bearing. A second groove is formed in the thrust bearing to hold oil discharged from the oil holes to some extent.

Thrust bearing for turbocharger

The invention relates to a foil bearing for high speed rotation such as a turbocharger, a high speed centrifugal separator or the like. The foil bearing according to the present invention can form at least three wedge-shaped spaces between the rotary shaft and the top foil along the direction of rotation of the rotary shaft. The rotary shaft can be supported by at least three portions of air sucked in the wedge-shaped spaces so that when the rotary shaft is rotated at a high speed, the axial center thereof is kept more adjacent to that of the top foil at all times based on the wedge effect by the air.

Growing community of inventors

Obu, Japan

Toshiro Kawakami