Abstract: Apparatuses are disclosed for providing directional control of bore drilling equipment. In an embodiment, the apparatus includes a hydraulic pump having an input shaft for receiving an input torque from a drill pipe and being connected in use to a drilling head. In addition, the apparatus includes control arrangement for varying the rate of fluid flow through the pump. The control arrangement includes a closed loop oil-filled system including the hydraulic pump and a main valve. Oil from the pump is routed through the main valve before returning to a pump input. In addition, the control arrangement includes an orifice control system which is operable to control the position of the main valve in response to an input signal from a control processor.

Abstract: Apparatuses are disclosed for providing directional control of bore drilling equipment. In an embodiment, the apparatus includes a hydraulic pump having an input shaft for receiving an input torque from a drill pipe and being connected in use to a drilling head. In addition, the apparatus includes control arrangement for varying the rate of fluid flow through the pump. The control arrangement includes a closed loop oil-filled system including the hydraulic pump and a main valve. Oil from the pump is routed through the main valve before returning to a pump input. In addition, the control arrangement includes an orifice control system which is operable to control the position of the main valve in response to an input signal from a control processor.