In cast iron up to and including size 280 speed reducers, except the series C4, K1 and K4; from size 320 in welded steel (Fe 430 B).
Upon request, the casings may be made of welded steel or ductile cast iron also for the sizes smaller than 320.
The reducers casings are provided with vent and oil filling plug, oil level sight glass and inspection hatch, as well as stiffening ribs and hoisting holes or hooks.
Pinions and gears
In alloy steel (18NiCrMo5 and 16CrNi4), with case-hardening (carburizing) and tempering heat treatment on the teeth.
After the heat treatment, the helical gears and pinions are ground on their involute profile, while the bevel pairs, with Gleason type teeth, are lapped, each gear coupled with its pinion.
Low speed shafts
In through hardened steel (36CrNiMo4, formerly 39NiCrMo3), with key and threaded end holes, dimensions according to the table:
The hollow low speed shafts are made of steel (Fe510). The connection to the driven shaft is usually made by means of a key.
Upon request, it is possible to perform this connection by means of shrink discs (see figure B).
Of the rollers type, from primary manufacturers, designed to allow for a long operating life and calculated according to ISO Standard.
Direction of rotation
Normally, rotation in both directions is allowed, except when a cooling fan is provided. In this case, the direction of rotation shall be stated when ordering the reducer.
Upon request, it is possible to provide a mechanism preventing rotation in the direction opposite to that of normal operation (back-stop device).
The power tables list the nominal ratios, while the actual ratios of every reducer can be found in separate tables.
Upon request, it is possible to supply reducers with special ratios, different from the ones listed on the catalog, modifying one or more gear pairs; in this case, it is necessary to contact our technical-sales department for the required checks of power and functionality.
Depending upon the operating conditions, i.e. the gears and pinions peripheral speed, oil splash type or forced feed lubrication may be adopted (see symbol "•" in the power tables).
In this latter case, the lubrication system may be equipped with an oil pump mechanically driven by one of the reducer shafts, or by one or more oil pumps driven by electric motors, and may be completed with all the necessary accessories and instrumentation (filters, flow indicator, pressure switch, pressure indicator, temperature indicator, oil-water or oil-air heat exchanger).
An assembly drawing of a typical forced feed lubrication system installed on a reducer is shown on figure C..
In any case, the lubrication system details must be discussed when ordering a reducer. The recommended lubricant types are listed on table 7.
Depending upon the operating conditions (absorbed power), the natural cooling may be sufficient (i.e. the capability of dissipating the generated heat directly from the outer surface of the casing towards the surrounding environment) or it might be necessary to remove the generated heat by means of one of the following devices: a cooling fan, a cooling coil submerged into the oil bath and fed with cold water, or an external oil circuit with cooling by means of a heat exchanger.
For the different types of reducers, the mechanical efficiencies are listed in the following table:
C1 = 0.99 K1 = 0.985
C2 = 0.98 K2 = 0.975
C3 = 0.97 K3 = 0.965
C4 = 0.96 K4 = 0.955
All the reducers are painted internally and externally with an epoxy primer, which guarantees an excellent anti-oxidation and anti-oil protection.
The outer finishing is performed with one layer of epoxy paint.
The standard final colour is green RAL 6011. Upon request it is possible to paint with any other final colour.
It is also possible to perform a standard painting cycle which is suitable to particularly aggressive environment (standard epoxy primer inside, grade Sa2.5 sand blasting outside, followed by one layer of inorganic zinc primer, one intermediate layer of epoxy-vinyl paint and one final layer of epoxy paint).
Furthermore, it is also possible to carry out special painting cycles, according to the customer's specifications.