Mazda Motor Corporation

Ichiro Hirose

Osamu Kameda

Junichi Okita

Hitoshi Akutagawa

Sakumi Hasetoh

Yoshimichi Tanaka

Masahiro Choshi

Noriyuki Iwata

Kouichi Hatamura

Satoshi Imamura

Akihiro Noda

Masaaki Sato

Sakumi Haseto

Kazuo Isayama

Tomohisa Handa

Nobuhiko Tanaka

Katsuya Miyoshi

Akie Kondo

A first balancer shaft includes a shaft extension portion extending forward, to which a driven sprocket is attached. A case member includes a first bearing portion supporting the balancer shaft near its weight portions and rotational gear and a second bearing portion supporting the same near its driven sprocket. The case member includes an upper case coupled to a cylinder block and a lower case facing to the upper case, and there is provided a case extension portion extending forward at the upper case. The first bearing portion is configured of a hole formed by half-split portions of the both cases and the second bearing portion is configured of a hole formed integrally at the case extension portion.

Balancer device of engine

An oil ring set has an expander between upper and bottom side rails for a piston of a reciprocal internal combustion engine. The oil ring set has dimensions determined so as to have a thickness satisfying a first relationship between a radial thickness and tension determined from a coefficient for an oil film thickness and a standard parameter representative of a predetermined thickness, a second relationship between a radial thickness and tension determined from a coefficient for an oil ring propensity to follow deformation and its pattern of the cylinder wall and a standard parameter representative of a predetermined amount of oil consumption, and a third relationship between a radial thickness and tension determined based on a coefficient representative of permanence of oil ring springiness against swelling and a standard parameter of the coefficient of springiness permanence.

Method for designing an oil ring

An automobile powertrain has at least an engine placed in an engine room and oriented so that its crankshaft is directed transversely, and a transmission placed in the engine room behind the engine. The transmission has input and output shafts arranged coaxially with each other and directed parallel to the crankshaft of the engine. An engine clutch is directly connected to the crankshaft, and a power transfer arrangement is disposed oppositely to the engine with respect to the engine clutch and operationally couples the engine clutch to the input shaft so as to transmit engine output to the transmission. The transmission, engine clutch and power transfer arrangement are independently accommodated in separate chambers of a single unit powertrain case. The transmission chamber and the power transfer chamber are connected to each other by an oil passage through which the input shaft extends from the transmission to the power transfer.

Powertrain for an automotive vehicle

In a construction of a vehicle power train in which a crankshaft of an engine and a shaft of a transmission are arranged in a car-width direction and a differential is disposed near the transmission, a power transmission element composing a part of a power transmission passage from the engine to a drive wheel is reinforced. An extension part extending to the cylinder block side of the engine is provided with respect to a bearing part of a back idle gear of the transmission provided at a cylinder block upper of the engine, and an extreme end of the extension part is connected to a rear side part of the cylinder block upper. The bearing part of a front-wheel differential is arranged so as to contact to a side of the bearing part of the back idle gear. Accordingly, rigidity of the power train is enhanced and an open/close mode movement caused between the engine and the transmission is prevented.

Construction of vehicle power train

A powertrain includes an engine and a transmission and has a center inertial axis extending in a transverse direction of the vehicle body. The powertrain is mounted on the vehicle body for inertial movement about the center inertial axis by a pair of elastic mountings, disposed on opposite sides of the powertrain and not below the inertial axis. Another elastic mounting is disposed behind the powertrain. An exhaust pipe assembly, extending rearwardly and down behind the powertrain from the engine, is flexibly supported by a retainer connected, either directly or through the other elastic mounting, to the powertrain.

Structure for mounting powertrain of vehicle

An engine unit includes an engine and a power train having a transmission and the engine unit is mounted sideways on a vehicle body with the power train positioned rearward of the engine. The engine and the power train are housed in a single engine housing and an oil pan common to the engine and the power train is mounted on the lower side of the engine housing below the engine and the power train. The length of the oil pan in the transverse direction of the vehicle body is smaller than the engine housing and auxiliary mechanisms are disposed in the space on one side of the oil pan and below the engine housing.

Structure of engine unit for vehicle

A power train includes a transmission having transmission shafts, with axes of rotation parallel to a crankshaft of an engine. The transmission shafts extend in a transverse direction of a vehicle. A drive axle is connected to drive wheels of the vehicle , and a drive axle differential differentially drives the drive wheels through the drive axle. A center differential is provided to differentially drive the front and rear drive wheels. The drive axle has an axis of rotation placed below and parallel to the axis of rotation of the transmission shafts. The drive axle differential and center differential are disposed side by side in the transverse direction of the vehicle body on, and in alignment with, the axis of rotation of the drive axle. The drive axle differential is located closely adjacent to the transmission in the transverse direction.

Power train for automotive vehicle

An engine unit includes an engine and a power train which are disposed in parallel to each other. The power train includes a transmission and a differential. The engine and the power train are housed in one engine housing formed of upper and lower parts which are mated with each other along respective mated surfaces. Upper halves of bearings for the crankshaft and upper halves of bearings for a rotational shaft of the power train are formed in the mating surface of the upper part of the engine housing and lower halves of bearings for the crankshaft and lower halves of bearings for said rotational shaft of the power train are formed in the mating surface of the lower part of the engine housing. The upper part of the engine housing is formed integrally with the cylinder block of the engine.

Engine unit

A method of assembling a valve driving mechanism, having a variable valve timing unit incorporated in a cylindrical mounting base, to a dual overhead camshaft engine. The engine has camshafts which are rotatably connected by camshaft gears. The method includes the initial step of mounting one camshaft gear, maintained at a predetermined angular position relative to the other camshaft gear attached to the other camshaft, and a lock nut on the one camshaft. Subsequent steps include first adjusting the angular position of the mounting base relative to the one camshaft gear and then the angular position of the variable valve timing unit relative to the one camshaft, and fastening the one camshaft gear to the mounting base by the lock nut and, simultaneously, the variable valve timing unit to the one camshaft.

Method of assembling valve drive mechanism to engine

A valve driving mechanism for a double overhead camshaft engine includes a camshaft drive mechanism, including a camshaft sprocket for transmitting engine output from a crankshaft of the engine to one of intake and exhaust camshafts. A valve timing varying mechanism is driven so as to vary a valve timing of, for example, a set of intake valves relative to a valve timing of a set of exhaust valves. The valve timing varying mechanism includes a first helical gear, mounted on the exhaust camshaft for rotation, a second helical gear, in mesh with the first helical gear, which is rigidly secured to the intake camshaft, and a cylindrical sliding element, mounted on the exhaust camshaft for axial displacement. The cylindrical sliding element operationally couples the exhaust camshaft to the camshaft drive mechanism so as to cause a relative rotational displacement therebetween when the cylindrical sliding element undergoes axial displacement with respect to the exhaust camshaft.

Valve driving mechanism for double overhead camshaft engine

A lubrication system for a double overhead camshaft engine has a lubrication oil passage for applying regulated pressurized oil to each of intake and exhaust overhead camshafts for lubrication; oil passages branching off from the lubrication oil passage for applying pressurized oil to hydraulic valve lash adjusters and a variable valve timing mechanism, respectively, for hydraulic operation. The oil passage for the variable valve timing mechanism is formed in one of the intake and exhaust overhead camshafts to which the variable valve timing mechanism is installed and is provided with a control valve for opening the oil passage so as to actuate the hydraulic variable valve timing mechanism with pressurized oil when the engine operates at lower engine speeds.

Growing community of inventors

Hiroshima, Japan

Ichiro Hirose