• Premium Transmission Limited

Overhung Loads Single Reduction Units

Premium speed reducers are fitted with taper roller bearings of generous proportions, which in addition to accommodating normal loads imposed by the worm gears, have an ample margin for taking overhung loads. In cases where external loads are applied in excess of this margin, wider taper roller bearings and wheel shafts of high tensile material can be fitted without any alteration to standard units. Whenever a sprocket, gear, sheave or pulley is mounted on the output shaft, a calculation should be made to determine the overhung load in Newtons on the shaft, using the specified formula. The calculated equivalent overhung load should be compared with the permissible values given in the table. These tabulated values are based on an input speed of 1500 RPM, with the unit transmitting full rated power and the direction of overhung load in the most unfavourable direction. Hence they can sometimes be increased for lesser input speed, or if the power transmitted is less than the rated capacity of the gear unit, or if the load is applied nearer to the gear unit case, or if the direction of load is more favourable. In any event the sprocket, gear, etc., should be positioned as close as possible to the gear unit case in order to reduce bearing loads and shaft stresses and to prolong life.