Komatsu Corporation

Takahiro Miyata

Hiroshi Endo

Sadao Nunotani

Kazuhiro Maruta

Toshiyuki Akasaka

Yoshiyuki Unno

Akinori Nagasugi

A method of suppressing a pulsation of axial type hydraulic pump/motor includes performing a pressure accumulation operation in which each of ports of each of two pressure accumulation oil passages exclusively communicates with a corresponding one of communication holes and pressure inside one of the cylinder bores is accumulated in a corresponding one of the pressure accumulation oil passages through the communication hole in two levels, the communication holes being provided for each of the cylinder bores to communicate with inside of each of the cylinder bores and having opening portions sliding on the respective ports with rotation of the cylinder block to communicate with the respective ports; and performing an accumulated pressure collection operation in which the pressure accumulated in the pressure accumulation oil passage is collected in one of the cylinder bores in two levels.

Hydraulic pump/motor and method of suppressing pulsation of hydraulic pump/motor

A radial type piston motor with a speed reducer capable of housing the speed reducer and the motor within width of a track shoe. For this purpose, in the radial type piston motor with a speed reducer: the speed reducer includes planetary gear trains of a plurality of stages; a hollow final shaft is integrally constructed in a motor case of the motor; at least a planetary gear train of one stage of the aforesaid planetary gear trains is placed in a hollow of the final shaft; and at least a final stage planetary gear train of the plurality of planetary gear trains is placed outside the final shaft.

Radial type piston motor with speed reducer

First and second pistons are provided in a body, the first piston is restricted by the body and the second piston, and the second piston is restricted by the body and a second piston restricting part. Thus, the first piston can be stopped at three positions, and the respective stop positions can be adjusted. Therefore, when rotation speeds of left and right rotating bodies are switched among three levels by a hydraulic motor, a difference of the number of rotations between the left and right rotating bodies can be eliminated, and a vehicle can be suppressed from deviating from a course while it is going straight. Further, a mounting area of the hydraulic pump can be decreased and a structure can be made simple. The rotation speed of the hydraulic motor is changed among the three levels by a simple structure and simple control without using a complex structure such as a servo valve and complex control. Further, the rotation speeds of the rotating bodies are switched among three or more levels by discontinuously positioning the piston not only at three positions but also three or more positions. Furthermore, the mounting area of the hydraulic pump is made small.

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Oyama, Japan

Takahiro Miyata