Abstract: A gear system includes a planetary gear and a frame structure including connection sections for attaching the frame structure to an external mechanical structure such as a nacelle of a wind power plant. The planetary gear includes a planet carrier, a sun wheel, a gear ring, and planet wheels meshing with the sun wheel and with the gear ring. The planet carrier includes a mechanical interface structure for connecting to an external rotating element such as a wind rotor. The frame structure includes a front cover shield that is a single piece of material, attached to the gear ring, and shaped to constitute a bearing cover for covering and supporting a bearing that supports the planet carrier. Thus, there is no need for a separate bearing cover.

Abstract: A gear unit comprises shafts (101, 102) for connecting to an external mechanical system, at least one gear stage (103) between the shafts, a lubricant oil room (104) for storing lubricant oil, an oil channel (105) for transporting the lubricant oil from the lubricant oil room to the at least one gear stage, and an immersion heater (106) for heating the lubricant oil flowing in the lubricant oil room towards an inlet of the oil channel. The gear unit further comprises a mechanical flow guide (108) located in the lubricant oil room and configured to modify flow of the lubricant oil flowing towards the inlet of the oil channel so as to increase flow velocity of the lubricant oil on the surface of the immersion heater. The increased flow velocity on the surface of the immersion heater makes it possible to use higher heating power without damaging the lubricant oil.

Abstract: A gear unit comprises shafts (101, 102) for connecting to an external mechanical system, at least one gear stage (103) between the shafts, a lubricant oil room (104) for storing lubricant oil, an oil channel (105) for transporting the lubricant oil from the lubricant oil room to the at least one gear stage, and an immersion heater (106) for heating the lubricant oil flowing in the lubricant oil room towards an inlet of the oil channel. The gear unit further comprises a mechanical flow guide (108) located in the lubricant oil room and configured to modify flow of the lubricant oil flowing towards the inlet of the oil channel so as to increase flow velocity of the lubricant oil on the surface of the immersion heater. The increased flow velocity on the surface of the immersion heater makes it possible to use higher heating power without damaging the lubricant oil.

Abstract: A method for controlling lubrication of a gear unit, where the lubrication method of the gear unit is changed between circulating lubrication and splash lubrication during operation of the gear unit, wherein the temperature of the lubrication fluid is measured, and the change between circulation lubrication and splash lubrication is based on the measured temperature of the lubrication fluid. The invention also relates to such a gear unit.