From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Product specification and operating manual for a Gear-Tooth Burnishing Machine.
| Identifier | ExFiles\Box 155\3\ scan0005 | |
| Date | 4th October 1933 guessed | |
| SOLE SELLING AGENTS ALFRED HERBERT LTD COVENTRY. Gear-Tooth Burnishing Machine Life of Burnishing Gears Burnishing gears, when properly taken care of and applied in the correct manner, will produce from twenty to twenty-five thousand gears before it is necessary to have them reground. Of course the life of the gears is dependent upon the number of teeth in the gear being burnished, the material from which the gear is made, the pressure required to produce the necessary finish, the care with which the gears are applied to the work, and the lubricant used. Advantages of Burnishing It cannot be too strongly emphasized that burnishing in no sense can be considered a corrective operation. A gear which has been inaccurately cut cannot be made accurate by burnishing. The more accurate a gear is before it comes to the burnishing machine, the better the burnished gear will be. This is true not only as regards tooth spacing, tooth shape, etc., but also the finish on the working surfaces of the teeth. It is evident, of course, that if the surfaces on the teeth are rough it will require more pressure and a longer time to get a smooth finish, and the pressure and time combined might result in producing an undesirable tooth shape. Burnishing, however, when properly done has a beneficial effect on the gear so treated. The surfaces of the teeth are compressed, resulting in a slight surface hardening and a refinement of the grain. Another advantage of the burnished gear is that its efficiency is increased. As a finishing operation prior to hardening, it can be used to remove burrs and bruises caused by careless handling. The practice followed by one large maker of gears is to take the burnished gears direct from the burnishing machines to the heat treating furnaces on a travelling conveyor. Fig. 5. Illustrating Special Fixture and 3-inch PD Burnishing Gears, for handling Gears from ¾ to 1½-inch Pitch Diameter. Specifications for Gear-Tooth Burnishing Machine Capacity: Maximum pitch diameter . . . . . . . . . . . . . . . . . . 8 inches Maximum face width . . . . . . . . . . . . . . . . . . . 1¾ inches *Minimum pitch diameter . . . . . . . . . . . . . . . . ¾ inch Design: This machine is especially adapted to motor drive and will be so equipped unless otherwise specified. Motor generally recommended is 1 H.P., ball-bearing motor, either A.C. or D.C., as required. Speeds: Speed generally recommended is 150 R.P.M. for driving burnishing gear, requiring a main shaft drive speed of 985 R.P.M. Weights: Of machine completely equipped, motor drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1550 pounds† Manufactured by: THE FELLOWS GEAR SHAPER CO. Springfield, Vermont, U.S.A. Weights—Continued Of machine crated for domestic shipment 1700 pounds† Of machine boxed for foreign shipment . . 2040 pounds† Motor weighs, approximately . . . . . . . . . 96 pounds Dimensions: Maximum length of machine . . . . . . . . 3’ 11” Maximum height of machine . . . . . . . . 4’ 9” Maximum width of machine . . . . . . . . . 3’ 7” Dimensions of crate for domestic shipment: One crate . . . . . . . . . . . . . . . . . . . . . . . . . 4’ x 5’ x 5’ 2” high Dimensions of box for foreign shipment: One box . . . . . . . . . . . . . . . . . . . . . . . . . 4’ x 5’ x 5’ 2” high Equipment: Standard equipment includes oil pump and all connections, guards, weights, motor bracket, and necessary wrenches. * For burnishing gears from ¾ to 1½-inch pitch diameter, 3-inch burnishing gears and special adapter are used. † Weights given include one set of 5-inch burnishing gears boxed—approximate weight 120 pounds. Printed in U.S.A. THE GEAR-TOOTH BURNISHING MACHINE, see Figs. 1 and 3, is used for smoothing the working surfaces of gear teeth after finish cutting. It comprises a base and bed, the latter carrying the principal working members. Three burnisher gears, A, B, and C, respectively, are used. Gear A is power driven by motor or belt, as required, through a reversing clutch, so that the gear being burnished can be rotated in both directions. Gear B is clamped to a stud rotating on ball bearings, and Gear C is held on a stud rotating in bronze bushings in arm D.{John DeLooze - Company Secretary} The arm D, see Fig. 3, carrying this stud is fulcrumed on slide E, which can be adjusted through handle F for burnishing gears of different diameters. Pressure for burnishing is applied through the gear C, the fulcrumed arm D, and removable weights W. The amount of pressure to use is governed by the pitch, diameter, and face width of the gear being burnished. The position of the fulcrumed arm D which carries the third burnishing gear C is controlled by a three-lobe cam L, the latter being operated by lever G, see Fig. 2. Forcing this lever forward separates the third burnishing gear C from the other two gears, allowing the work to be removed; whereas pushing it backward brings the gears into contact with the work. Then by shifting the lever H, Fig. 1, towards the operator, the work is rotated in a clockwise direction. Moving it away from the operator rotates the work in a counter-clockwise direction. Fig. 1. Combined Front and End View of Gear-Tooth Burnishing Machine, showing Push-button Control. Operating Gear-Tooth Burnishing Machine This Gear-Tooth Burnishing Machine is simple and easy to operate. The setting-up operations are few in number and easily accomplished. In starting the machine for the first time, remove oil filler cap in housing at rear of machine, and pour 3½ quarts of light machine oil into the reservoir. All of the working members of the machine, with the exception of stud on which gear C is held, are lubricated from this one source. As a burnishing lubricant, mix light machine oil and kerosene in the proportion of four parts kerosene to one part machine oil, and pour one gallon of this through the strainer in oil pan at V in Fig. 3. This lubricant is pumped through pipe U which carries the flow of oil directly between gears A and B. Before starting the machine in operation, the first step is to be certain that the clutch operating lever H, see Fig. 1, is in the neutral position. The three burnishing gears A, B, and C are selected for the work and placed on their respective studs. These gears are interchangeable, all having a 1¾-inch hole, 2-inch face, 5-inch approximate pitch diameter. These gears should be cleaned carefully before assembling on the machine; and care, of course, should be taken to see that the driving gear A is held tightly on the main driving shaft by the nut. The next step is to loosen the bolts J, Fig. 3, which hold the slide E in position. The gear to be burnished is now placed between the three gears, pin K, Fig. 3, re- | ||