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316 THE MARINE REVIEW FIG. 2 decreased, and a decrease in the rev- olutions of the turbine necessitate an increase in the diameter of the pinion, since the torque transmitted for a given horsepower is inversely propor- tional to the revolutions per minute. By the use of the floating frame, the size of the pinion required for any given horsepower is not limited by the diameter of the pinion, torsional deflection or strength of the teeth, but by the size of the bearings. Since it is not desirable to make the journals much larger than the outside diameter of the pinion, and only certain maxi- mum bearing pressures and _ surface speeds are permissible, the limit of capacity of the pinion is reached when the bearings are loaded to the maxi- mum safe limit. In general, however, it is not necessary nor desirable to undercut the pinion teeth below the journals, and the pinion diameter is made just large enough so that the cutters clear the journals: Thus it is seen that the capacity of Westing- house pinions of any given size is much greater than in any other sys- tema Of cearing, and the size -and weight of the gear are far less for a given ratio of reduction, or for any given limit of diameter of the large gear wheel, a large ratio of reduction may be used. It will be readily understood from the preceding that particularly in ma- rine installation where weight and space, as well as economy, are the most important factors, it is imper- ative to have some means of permit- ting the pinion to assume its natural position in order that a considerable torsional deflection is allowable, and consequently a small pinion diameter for any given power transmitted. In many marine installations of re- duction gears without means for per- mitting the pinion to assume _ its natural axis, the result of the neces- sity for an increase in pinion diameter and the consequent limited ratio of reduction, is evident, as with two ex- August, 1914 ceptions, in all the geared installa- tions with solid pinion bearings, high speed propellers running as fast or faster in some instances than would have been considered necessary in a direct connected turbine installation, have been employed, and in each in- stance the revolutions of the turbines were considerably lower than desira- ble for the power developed. Thus, though gears were added, no advan- tage could be taken of the increase of the efficiency of the propellers which would result from a lower pro- peller speed, and only part of the gain in economy was realized by increasing the revolutions of the turbines, though some saving in weight was obtained. In the Westinghouse gear, the use of a pinion of minimum diameter and a high speed turbine, has the very marked advantage of permitting the use of very small turbines for the power developed, making all the parts small and easily handled in addition to the saving in weight and increased economy of the turbine, and decrease of power required due to the use of slow speed propellers of high effi- PIG. 3