Description of low-speed eccentric gear boxes type EC BOX
One-stage eccentric gear box with cylindrical output shaft
The eccentric gear boxes of type EC BOX are of the compact type reducers being distinguished by high gear ratio, small dimensions and of scarceness parts and small volume of lubricating filling. . A thing is the matter of special type of differential epicyclic gear having relative movement of the satellite gear on the eccentric output shaft.
The mentioned series of gear boxes are fitted with one satellite gear in the one speed gear which is in gear with a fixed crown bear. Number of crown gear teeth is against the satellite higher about small difference (1 – 3) teeth.
Rolling distance of this gearing is constructed of an input shaft eccentricity which is aligned by the cross coupling (Oldham) on the output side.
The gear boxes it is possible to use either separately or with a flanged electric motor and into an equipment they are can fixed either with their c.g. position and case body bolts or with a flanged extension or also as suspended for their output shaft which is equipped with threaded hole. Then it is possible to use reaction brackets or draw rods which catch torque reactions up to case body during operation.
Beside one-stage workmanship it is possible to order also two-stage workmanship in standard combinations mentioned in the dimension sketch. It is possible to use also the footing connection, the footing extension it is possible to fix on the case body. Also it is possible to use them also in controlled drives. Also the application of two-stage combinations of eccentric reducers is very effective.
The gear boxes are distinguished by silent smooth working, small gearing clearances, low inertial masses and very small lubricating oil filling. They have multilateral use not only in industrial drives of assorted applications but also in the traction drives, where they are self-assertive by their variability, small building dimensions and good efficiency and energy economy.
Construction workmanship
Partial section of the one-stage gear box
The functional parts and the gear box case are made from carbon or alloy steels, the hardened parts are case-hardened or nitrided, the castings are made from nodular cast iron.
The shafts are mounted in double-row ball oblique bearings and in the standard workmanship the input hollow shaft corresponds the shaft of appropriate electric motor, the output shaft is a cylindrical type having a key (ČSN 014990)m or has a involute splining according to ČSN 014952 say either on the pin or hub.
The involute grooves are centralized by their sides and are made in the tolerance 8f for splined shafts and 9 for splined hubs.
The bearings and gear box functional parts are designed for operation time of 10 000 operation hours at operation coefficient 1.
From now on for the eccentric reducers on their input it is permitted to use standard operation revolutions up to 1500 RPM. Providing that the input power will not be increased, it is permitted – with reference to frequency controlled drives – to increase input revolutions till about 20% that is to the value 1 750 RPM. However basically in the future for these reducers it takes account of the using of 4 pole and multipole electric motors in the range of sizes 56 – 132. The standard ratio values in one stage are 13, 17, 21, 25, 32, 41, 53, 67, 83 and 97 and for special demand it is possible, after technical discussion, to deliver also the gear box having the other gearing in the range 10 – 110 in one stage at intervals supplied outputs, in case of need also with special workmanship out of these values towards.
According to their dimensions, the gear boxes of mentioned series are divided into nine classes marked by numbers 0 – VIII in agreement with corresponding electric motor sizes. The two-stages combinations are possible for series VIII, where the first stage is composed from the gear box of lower size about three series. The standard gear box combinations are mentioned in further description, for the special workmanship it is possible to reach the gear ratio up to 1200. The two-stage combinations are determined especially for kinematic gearings, controllers and servo-drive of positioning etc. They acquit well also in overhead transport and in slow traction drives.
From the year 1999 the eccentric reducers are newly launched for higher outputs of series VIII. These reducers have the same dimensions as the series VII, but have other kinematic scheme and are distinguished by essentially higher power intensity and high accuracy (non-linearity is above 5 angular minutes). The standard gearings are slightly different from the series 0 – VII, the application of the reducers of series VIII is the analogical as for the series VII, sure for higher load and output. The two-stage combination is possible also with the reducer of series IV. (EC VIII./IV.).
Working positions and lubricating
The basic working position of gear boxes is horizontal, to this the filling and drain plugs and the control bolt on case gear box cover correspond. The gear box inclined position in 45º of sway from the horizontal position is admitted without any modification form the current workmanship, say for the position with the output upwards and input down. Other working positions (higher slope, vertical gear box position) it is necessary to specify
in an order and discuss with the producer owing to necessity of modifications as far as the filling, lubricating and deaeration of the reducer. In case of using of two or more stages, every stage has proper lubricating oil filling and proper deaeration. The reducers filled by plastic lubricant (size I. and II.) it is admitted arbitrary working position. These reducers are totally sealed. (without deaeration).
Recommended lubricants
Mineral oils
GYROL PP80, PP90, PP90H or their equivalents. The gear boxes are delivered with the oil filling only as option, the current delivery is without this filling.
Oil replacement is recommended after running-up (200 – 300 operation hours) and then after 2500 – 5000 operation hours or after two years, in case of need according to operation conditions (temperature, load, dustiness) and the recommendation of producer.
Synthetic oils
is possible to use for the power severe applications usually at the using oils having the viscosity ISO VG 63-150 DIN 51519.
For reducers EC BOX of series I. and II. the permanent filling of plastic lubricant MOGUL L 1 EP is used during production, as option it is possible to use the mineral oil GYROL ( in case of need the other type). For the reducers of series III. and IV. the mineral oils (GYROL) are used during production, for series V, VI, VII and VIII the synthetic oils (TORAL CARTER EP/HT 150).
Note: Mixing of synthetic and mineral oils is not permitted. More detailed recommendation is in the Service instructions which is delivered with every reducer.
Mounting of reducers
The one-stage gear box is fixed by their threaded holes having the c.g. position on the forehead of case body, the multistage combinations are fixed also by means same holes and c.g. position but on the ending stage. The catalogue flanged extension can be also as a optional delivery part.
The output shaft is equipped with sufficiently sized thread, so that it is possible to use the gear box as a suspended one. The torque reactions to case body must be catched by reactive rods or brackets in the range of moments and forces mentioned in the dimensional sketch. In case of using of splined output ends of reducers it is necessary to provide the building installation in order these ends transfer only rotary moment and not to be stressed by radial forces.
Working environment
The gear boxes are determined for normal working environment at ambient temperatures - 5º C up to + 40ºC, they can work in the environment according to ČSN 330300 stated by a producer of used electric motor. Dissimilar employment is possible after discussion with the producer.
Conservation
The gear boxes are delivered without surface treatment. According to wish of a customer there is a possibility of surface treatment in accordance with an agreement The conservation durability during stocking in dry and clean environment without sudden temperature changes ensures a prevention for the time al least 6 months.
Choice of gear box
Output moments T2 (mentioned as parameters of size series) are considered for smooth impactless running at ambient temperature 20º C with sufficient air flow over gear box surface and with ten starts in an hour at increased moment during the starting on the double value T2 during the time of two seconds. For operational application it is choosed a gear box with higher value of nominal moment T2 depending on operation conditions which are usually stated by operational coefficient KA according to the formula
Tp - equivalent rotary moment for the choice of gear box
Ts - recommended effective driving moment of an equipment, whereas it is necessary to keep
The directive value of operational coefficient KA is stated from the table according to the formula
Coefficient of driving machine f1
For the drive of an electric motor f1 = 1,0 . The other drive it is necessary to discuss with the producer.
Coefficient for the operation f2
Loading way Operation time in a day
till 3 hours
continuous
slight beats
strong beats
Running coefficient f3
Number of starts Coefficient value f2
in an hour
till 10
over 100
Time coefficient f4
Percentage of activity under load from operational time
Time coefficient f5
Ambient temperature º C
Types, sizes and workmanship of gear boxes
Gear box size stage
Strana 14
Marking Corresponding motor size Output for 4 poles
The motors are supposed in the flanged design B5 IM 3081, 4 poles, assembly of mutltipole motors is possible.
Gear box workmanship
EC without electric motor
ECP without electric motor with flanged extension ECM with electric motor
ECMP with electric motor and with flanged extension on the end stage
Type marking of a standard gear box (examples)
EC II /21
one-stage gear box of size II, gearing 21 in the basic workmanship, cylindrical output shaft
ECM I / 83, 4AP 63 – 4
one-stage electric gear box of size I, gearing 83, with flanged electric motor of given type, cylindrical output shaft
ECMP IV / 67, splined hub
one-stage electric gear box of size IV, gearing 67, with catalogue workmanship of splined hub on the output side and with the flanged extension
ECM IV/I-861, 4APB63-4
two-stage electric gear box of size IV, on the end stage, total gearing 861, with mounted brake electric motor of given type and cylindrical output shaft of end stage
Two-stage gear box with electric motor
ECP IV / I – 861, input pin, splined output shaft
Two-stage gear box of size IV on the end stage, total gearing 861, on the input side the cylindrical pin and on the output the splined shaft of catalogue workmanship. Flanged extension.
The other workmanship (for example a special output end workmanship, other than standard position of reducer, special demands for gearing combination in single stages or demand for electric motor of certain mark etc.) it is necessary to specify verbally or in case of need by reference to negotiated documentation.
Standard versions of gearing
One-stage gear boxes of series 0 – VII (series V – VII has tapered range of gearings)
One-stage gear boxes of series VIII
Two-stage gear boxes (combination of reducers up to series VII)
