Komatsu Corporation

Kaoru Hasegawa

Kenjiro Shimada

Shinichi Naito

Osamu Kodama

Toshiyuki Hirashita

Tsutomu Komatsu

Yuuichi Fukata

Hitoshi Miyamoto

Nobuaki Kawasaki

Hiroaki Kitamoto

In order to decrease the number of handling components of a parking brake unit without increasing a length of a wheel base, there is provided a forklift including a main input shaft which is rotationally driven by a hydraulic motor, a differential input shaft which rotates by the rotation of the main input shaft, and a differential mechanism which is provided between the differential input shaft and a front axle, the forklift being configured to run by transmitting power of the hydraulic motor to the front axle through the main input shaft, the differential input shaft, and the differential mechanism, wherein an idle shaft is disposed so as to be parallel to the differential input shaft, a power transmission mechanism obtained by meshing gears and is interposed between the differential input shaft and the idle shaft, and then a parking brake unit is provided in the idle shaft.

Forklift

A cylindrical roller bearing or needle roller bearing for use with a rolling raceway surface is subjected to a carbonitriding treatment to produce a layer containing 30 to 80% retained austenite in the vicinity of its surface that contacts a carburized layer of a rolling raceway surface of a roller bearing. The amount of retained austenite of the surface layer of the roller bearing is increased by about 30%. The surface layer is then heat treated to apply a residual compression stress. The surface then receives surface finishing to produce micro concavo-convex portions in a random direction.

Method for forming a bearing race for a cylindrical bearing

Hydraulic pressure is controlled, which has such advantages that a generation of peak pressure (shoot pressure) can be lowered, mis-operation due to biting of particles can be reduced, or the cost thereof can be reduced. First, a large amount inflow command current is supplied to a proportional solenoid from a time point t to a time point t . Consequentially, pilot pressure rises in a pilot pressure receiving chamber, so that a pressure control valve allows a large amount of hydraulic fluid to flow in a clutch or brake cylinder. At this time, potential detected by a pressure switch becomes zero level. Next, at the time point t , a filling command small current is supplied to the proportional solenoid, thereby decreasing the amount of hydraulic fluid, which flows from an input port to an output port. This state is maintained from the time point t to a time point t . At the termination of filling, peak pressure will not be generated, and a speed-changing shock in a clutch will not be generated, so that smooth switching can be accomplished.

Valve apparatus for controlling hydraulic pressure for a clutch or a brake and method for controlling hydraulic pressure

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Yuuki, Japan

Kaoru Hasegawa