| Show MOTOR FOR STAMP MILL DRIVE WRITTEN FOR THE MINING REVIEW the illustration shows a special application 0 athe westinghouse standard motor for stamp mill drive in connection with the mining industry it has been the practice in the past to belt a large motor to long line shaft and from th this s line shaft belt to each battery of stamps usually ten stamps per battery this method results in a very great amount of loss in transmission of power by reason of the fact that the continual jar of the stamps in the foundations throws the line shaft bearings out of alignment and involves considerable loss in the belt friction when different groups of stamps are out of service this motor designed to belt directly to a battery of ten stamps is of 25 horse power service with line shaft drive the bell and cam shaft of the battery continues to run when the battery is idle the motor gear and pinion car can be replaced or taken away for repairs without disturbing the lineup line up of the pulleys and the handling of the extremely tre niely heavy belt an especially long sliding base Is furnished to take up the stretch of belts the cradle to which the motor is belted is securely held to the sliding base by means of four machine bolts which can be loosened when it is necessary to change the tension on the belt one special point of this drive is the split bearings with back gear shaft making it possible to readily inspect or change these bearings after slacking off the belt 4 71 A 1 Z capacity at r p in and is placed in a special back gear cradle which carries a countershaft on which is mounted a gear and pulley for especially slow belt speed the gear ratio is 27 to 99 giving a countershaft speed of approximately feet per minute the gear case is oil proof the cradle and gear ease case are standard but a smaller motor can be used where the drops are fewer per minute or the stamps lighter the stamp mill requires especially heavy slow speed belt usually 7 ply canvas this combination of motor drive for each battery of stamps has the advantage of dispensing with the long za line of and its consequent losses and permits shutting down the complete battery when out of this motor cabbe can be supplied with auto starter having both no voltage and overload release through a type H breaker making it possible to cut both the auto starter and motor out of circuit in case of necessity for making repairs this equipment is particularly recommended for stamp mill drive as against the older methods and more particularly in preference to the long line shaft drive with a single motor belted to the line shaft the outfit as a whole is designed for the extremely heavy service encountered in stamp mill work and should serve to popularize the use of electric motors in stamp mills |
