Abstract: A method and an arrangement in power transmission of a forest machine (1), the forest machine including a primary power source (5) for generating power required for moving and controlling the forest machine and/or actuators (6, 7) therein. In the present method and arrangement, at least part of the power generated by the primary power source (5) is converted into electric energy by a generator arrangement (8). This electric energy can be stored at least partly in an electricity storage unit (9), from which part thereof can be used, when required, for generating pressure medium-transmitted power for implementing a pressure medium-transmitted function of the forest machine (1) or at least one actuator (6, 7) therein.

Abstract: A method for controlling a power source (1, 10) of a forestry machine, wherein the power source utilizes directly or indirectly one or more work devices and/or handling devices (3, 4, 7, 8) positioned in the forestry machine and is controlled by a control unit (2). When the control unit in the forestry machine gives one or more work or handling devices a control command starting a change operation, it is transmitted substantially simultaneously to the power source. When arriving at the power source, one or more control commands requiring a power change of the power source affect control parameters of the power source, predicting the future load of the power source.

Abstract: A method and an arrangement in power transmission of a forest machine (1), the forest machine including a primary power source (5) for generating power required for moving and controlling the forest machine and/or actuators (6, 7) therein. In the present method and arrangement, at least part of the power generated by the primary power source (5) is converted into electric energy by a generator arrangement (8). This electric energy can be stored at least partly in an electricity storage unit (9), from which part thereof can be used, when required, for generating pressure medium-transmitted power for implementing a pressure medium-transmitted function of the forest machine (1) or at least one actuator (6, 7) therein.

Abstract: A method for controlling a power source (1, 10) of a forestry machine, wherein the power source utilizes directly or indirectly one or more work devices and/or handling devices (3, 4, 7, 8) positioned in the forestry machine and is controlled by a control unit (2). When the control unit in the forestry machine gives one or more work or handling devices a control command starting a change operation, it is transmitted substantially simultaneously to the power source. When arriving at the power source, one or more control commands requiring a power change of the power source affect control parameters of the power source, predicting the future load of the power source.