Jahn's Speed Governor

Jahn's Speed Governor

This is an example of the centrifugal governor, for high speed engines and steam turbines, patented by Mr. W. Jahns in 1912. It is very sensitive, as the weights move horizontally, and is constructed so as to eliminate friction as far as possible. The governor is contained in an oil-tight casing fixed to the top of a vertical shaft. The weights are flat and are fitted with vertical and horizontal rollers running on planes prepared for them on the casing. The weights are pressed towards the centre by helical springs, fitting into recesses in them, and tightened up by nuts screwed on a central stud passing through a hole in the top of the shaft. The nuts fit into holes in the cylindrical portion of the casing, and the springs are adjusted by inserting washers behind them. Vertical slots, formed through the weights, engage with rollers mounted on the upright arms of two bellcrank levers pivoted on the casing; the lower arms of these levers engage with inclined slots formed on a sliding sleeve inside the casing, and this sleeve is connected with another, outside the casing, by two rods passing through holes. Arrange- ments are provided for leading oil from a central reservoir to the upper bellcrank rollers, while the weight rollers are always immersed in oil.