Gear unit and a method for controlling a lubrication pump of a gear unit

A gear unit comprising:

• a first shaft and a second shaft for connecting to an external mechanical system,
• at least one gear stage between the first and second shafts,
• a lubrication pump for circulating lubricating oil through the at least one gear stage and bearings of the gear unit,
• a temperature sensor for measuring temperature of the lubricating oil and supplying a temperature signal representative thereof,
• an electrical motor for driving the lubrication pump, and
• an electrical device for energizing and controlling the electrical motor, the electrical device limiting torque directed to the lubrication pump is below a torque limit,
• wherein the electrical device:
• limits rotational speed of the lubrication pump to be below a speed limit simultaneously with limiting the torque directed to the lubrication pump to be below the torque limit, and
• increases the speed limit and decreases the torque limit at a rate where an upper limit of a mechanical power directed to the lubrication pump is kept substantially constant in response to an increase of the temperature signal indicative on an increase of the temperature of the lubricating oil.