Mazda Motor Corporation

Yukio Misaki

Akihiro Noda

Hirotaka Tamari

Shigeru Wada

Koji Kumagai

Tatsunori Sasaki

Shigeki Komatsu

Takahiro Onda

A crankshaft bearing structure is provided, in which a crankshaft includes a first crank journal and a second crank journal, and a crank pin disposed therebetween. First upper-and-lower journal bearings and second upper-and-lower journal bearings are attached to the respective crank journals, and each upper bearing includes an oil hole connected to an oil passage to supply oil to between the crank journal and the journal bearings. An in-shaft oil passage is formed in the crankshaft to draw oil from an outer circumferential surface of the second crank journal to an outer circumferential surface of the crank pin. The second upper journal bearing has, on an inner circumferential surface thereof, a circumferential groove connected to the oil hole. The oil is supplied to between the first upper-and-lower journal bearings and the first crank journal, only through a passage passing through the oil hole of the first upper journal bearing.

Crankshaft bearing structure

A valve system includes: a cam shaft including a shaft section and a plurality of cam element sections; and a plurality of operation members that moves the cam element sections in an axial direction. The plurality of operation members include a common operation member that is provided in common between end face cams opposed to each other of the cam element sections of two cylinders disposed adjacent to each other and continuous in ignition order and that engages with the respective end face cams when both the cam element sections are close to each other, and individual operation members that are individually provided for end face cams opposed to each other of the cam element sections of two cylinders disposed adjacent to each other and discontinuous in ignition order and end face cams located at opposite ends of a cylinder row and that engage with the respective end face cams.

Valve system for a multi-cylinder engine

Growing community of inventors

Hiroshima, Japan

Yukio Misaki