Traveling system for engineering machine

A traveling system for an engineering machine comprising:

• an engine, a travel device driven by the engine, a multi-speed motive power transmission provided on the travel device, and gear selection means for selecting a gear of the motive power transmission, the motive power transmission being an HST including, in addition to a hydraulic pump driven by the engine, at least one hydraulic motor of a variable-displacement type connected in a closed circuit to the hydraulic pump,
• the traveling system further comprising:
• vehicle speed detection means;
• motor control means for controlling the capacity of the hydraulic motor according to an actual vehicle speed detected by the vehicle speed detection means, and limiting a minimum capacity of the hydraulic motor to a preset capacity limit (q2cmin) during selection of either the highest gear or the next highest gear as a required gear by the gear selection means when the actual vehicle speed reaches a preset vehicle speed limit (Scmax);
• and
• engine control means for limiting a maximum engine speed to a preset first engine speed limit (Ncmax1) lower than a maximum rated engine speed, during the selection of either the highest gear or the next highest gear as the required gear by the gear selection means, when an actual vehicle speed detected by the vehicle speed detection means approaches a preset vehicle speed limit (Scmax).