A device in a hydraulic rock drilling machine (1) has a distribution valve (7, 7, 7) for controlling hydraulic flow to different parts of the rock drilling machine. The distribution valve has a valve body (8, 8, 8) which moves to and from in an axial direction inside a valve chamber (33). The valve chamber is limited in axial direction by two valve end walls (10, 11; 10, 11; 10, 11). One of the valve end walls is movable in an axial direction against an abutment (12, 12) to define an end position for the valve body, and a pressing device (13, 13, 13) is provided for pressing at least one of the valve end walls against the abutment. A rock drilling machine includes the device.

A slide valve for a hydraulic percussion device. The slide valve includes a transition surface that is arranged to alternately be subjected to a working pressure and a tank pressure to carry out a reciprocating movement when the percussion device is in use. The slide valve includes at least one channel that is open at one end of the slide valve, and at least one displaceable pin that is arranged inside the at least one channel.

A slide valve for a hydraulic percussion device. The slide valve includes a transition surface that is arranged to alternately be subjected to a working pressure and a tank pressure to carry out a reciprocating movement when the percussion device is in use. The slide valve includes at least one channel that is open at one end of the slide valve, and at least one displaceable pin that is arranged inside the at least one channel.

A device includes an actuation system with a dose chamber including an inlet for high pressure fluid. A working chamber extends away from the dose chamber. An annular wall separates a portion of the working chamber from the dose chamber such that the dose chamber encompasses the portion of the working chamber. In use an item to be driven along the working chamber is at least partially within the surrounded portion of the working chamber with the item at one end of its travel in the working chamber. A valve mechanism selectively allows high pressure fluid from the dose chamber to flow into the piston chamber.

A device includes an actuation system with a dose chamber including an inlet for high pressure fluid. A working chamber extends away from the dose chamber. An annular wall separates a portion of the working chamber from the dose chamber such that the dose chamber encompasses the portion of the working chamber. In use an item to be driven along the working chamber is at least partially within the surrounded portion of the working chamber with the item at one end of its travel in the working chamber. A valve mechanism selectively allows high pressure fluid from the dose chamber to flow into the piston chamber.

A valve of a hydraulically striking device having a housing, the housing having a moving member being seated inside the housing to move in a reciprocating manner by means of a hydraulic fluid. The moving member has an inner space, the housing has at least a first abutment surface abutting the moving member, the first abutment surface of the housing has a first surface located in a radial inner portion of the first abutment surface, wherein the first surface is arranged in fluid communication with the inner space, and a second surface located in a radial outer portion of the first abutment surface, wherein the second surface is arranged to form a sealing surface.

A valve of a hydraulically striking device having a housing, the housing having a moving member being seated inside the housing to move in a reciprocating manner by means of a hydraulic fluid. The moving member has an inner space, the housing has at least a first abutment surface abutting the moving member, the first abutment surface of the housing has a first surface located in a radial inner portion of the first abutment surface, wherein the first surface is arranged in fluid communication with the inner space, and a second surface located in a radial outer portion of the first abutment surface, wherein the second surface is arranged to form a sealing surface.

A hydraulic system, rock drilling rig, and method for limiting output performance of a hydraulic drilling actuator temporarily under execution of a safety function feature of a hydraulic system is provided. The output performance is limited by limiting produced hydraulic fluid flow in a hydraulic circuit of the hydraulic drilling actuator, whereby a restricted magnitude of the fluid flow is produced at a hydraulic pump. This way a restricted operation mode is enabled and is controlled by a control unit.

A hydraulic system, rock drilling rig, and method for limiting output performance of a hydraulic drilling actuator temporarily under execution of a safety function feature of a hydraulic system is provided. The output performance is limited by limiting produced hydraulic fluid flow in a hydraulic circuit of the hydraulic drilling actuator, whereby a restricted magnitude of the fluid flow is produced at a hydraulic pump. This way a restricted operation mode is enabled and is controlled by a control unit.

Lubrication system includes a drive fluid valve member and a detune valve member. The drive fluid valve member is movable from a first to a second position in response to drive fluid pressure to reduce the volume of a variable volume lubricant charge chamber. The detune valve member is movable from a first to a second position in response to lubricant pressure within the lubricant charge chamber, and is adapted to permit fluid communication between inlet and bypass fluid passages in its the first position and to disengage the fluid connection in its second position.