Nippondenso Co., Ltd.

Naohiro Naganuma

Mikiji Ito

Shojiro Nagano

Motohisa Miura

A diaphragm pump including an eccentric circular cam or crank shaft, a connecting rod rotatably connected at one end to the eccentric circular cam or crank shaft, a pair of diaphragms each having one surface serving as pressure receiving surface, center disks mounting the central portions of the pair of diaphragms on the opposite sides thereof, a first housing cooperating with one of the diaphragms and the center disks to define a first discharge chamber, a second housing cooperating with the other of the diaphragms and the center disks to define a second discharge chamber, a third housing cooperating with the pair of diaphragms and the center disks to define a suction chamber, a connecting member connecting the other end of the connecting rod to the center disks in the radial center and in the middle of the thickness thereof in order to minimize any swinging movement of the center disks which would otherwise be caused by reciprocatory swinging movement of the connecting rod, and guide means for guiding the center disks for preventing any swinging movement thereof.

Diaphragm pump

An engine exhaust gas purification system includes an EGR line for the recirculation of exhaust gases from an engine exhaust system back into an intake system thereof. An EGR valve is provided in the EGR line to control the rate of EGR. The EGR valve is actuated by an actuator which is operated by pressurized air supplied by a diaphragm pump driven by the engine in proportion to the engine speed. The pressure of the pressurized air is substantially proportional to the engine speed, whereby the EGR rate is controlled so as to be substantially proportional to the engine speed.

Exhaust gas purification system for an internal combustion engine

A diaphragm is interposed between first and second housings to form first and second diaphragm chambers at both sides thereof for pumping out air in accordance with expansion and contraction of the chambers. A shaft for reciprocally moving the diaphragm is connected thereto at one end and extends through a hole formed in a bushing which is fixed to the second housing. A lever is pivotally secured to the housing to perform a pivotal movement and operatively connected at its inner end to the other end of the shaft in a lever compartment of the housing and at its outer end to an eccentric cam formed on an engine crankshaft, so that the motion of the cam is transmitted to the shaft as the reciprocal movement through the pivotal movement of the lever. A bellows is disposed in the second diaphragm chamber surrounding a portion of the shaft, wherein the upper and lower ends are respectively and air-tightly connected to the diaphragm and the bushing to form a bellows chamber. An axially extending groove is formed on either the inner surface of the hole or the outer surface of the shaft, so that the bellows chamber is communicated with the lever compartment by the groove. The compartment is communicated with an engine crankcase and thereby filled with a large amount of engine oil mist. The bellows chamber is also subjected to expansion and contraction in accordance with the reciprocal movement of the shaft to alternately draw into and force out air in the compartment, so that a portion of the mist is forcibly introduced into the groove to lubricate the shaft and the bushing.

Growing community of inventors

Kariya, Japan

Naohiro Naganuma