Apparatus for subsoil constructions provided with a pressurized gerabox and method of regulating pressure inside said gearbox

摘要

The gear unit has an active setting device (20) controlled by a control device and changing pressure inside a gear housing (16). The device has a pump and/or a compensating tank which are connected to inside of the gear housing through a fluid line (24) to supply and/or discharge a fluid. A pressure sensor measures a pressure inside and/or outside the gear housing, and is in signaling contact with the control device. Independent claims are also included for the following: (A) a trench cutter comprising a gear unit (B) a method for controlling an internal pressure in a gear unit.