HOUSING
Rigid, robust, torsion
resistant housing in high quality close grained Grey Cast Iron
generously proportioned to ensure proper radiation of any heat
generated when Units are operated at their maximum capacity Suitable
ribs are placed underneath the bearing seats for strength and the
walls are of sufficient thickness to withstand the most severe
stresses encountered during operation. On request the housing is
manufactured of fabricated construction. Housing in cast steel or
fabricated steel can be supplied if required.HELICAL GEARS &
PINION SHAFTS
i. FOR CASE HARDENED
& GROUND GEARBOX
Helical gears, Pinion Shafts have involute profile teeth and are
manufactured from high alloy case hardening steel. After case
hardening, the gear teeth are profile ground to provide a highly
efficient and quiet running drive. All gear teeth are with involute
profile duly corrected as per the most modern methods which increase
dedendum bearing capacity and reduce noise level.
SHAFTS
The low speed shafts are made from medium carbon steel duly heat
treated and are finished to high precision tolerance by grinding. The
low and high speed shaft extensions are fitted with oil seals to
prevent leakage of oil and entry of dust.
BEARINGS
Antifriction bearings of ample size are used to ensure long service
life. The use of antifriction bearings ensures high efficiency,
correct centre distance and proper shaft alignment. In case of extra
overhung load due to pulley, pinion etc. on shafts, reinforced extra
heavy bearing is used.
DIRECTION OF
ROTATION
Even though the gearboxes are suitable for rotation in either
direction, the running in and the functional test run is done in the
direction of rotation specified. If the gearbox is required to be used
in either direction, the same should be specified in the order.
LUBRICATION
For normal speeds, splash lubrication is provided by the gears
dipping in oil. Oil reservoir is of ample size to ensure cool
operation. The oil level indicator located in the housing is to ensure
a proper amount of lubricant in all housing. Wherever splash
lubrication is not effective to carry oil to gears and bearings,
either due to low input speed or high peripheral speed a built-in or
separately mounted lubrication oil pump is used for forced-feed
lubrication.
COOLING
In most cases depending on the power to be transmitted and the ambient
temperature, the heat generated in the gear units is dissipated
through a sufficiently large surface area of the housing. Additional
cooling by use of fans, cooling coils inside the lower part of the
housing or a separate oil cooler is provided where simple radiant heat
dissipation is not adequate. Flow indicator, Pressure gauge are
installed for checking oil circulation with provision to connect to
audio-visual alarms.
OVERHUNG LOADS
The bearings can withstand overhung loads arising due to mounting
of flat and V-belt pulleys, gear wheels and chain sprockets of
appropriate dimensions on the input and output shafts. In order to
check bearing life or for recommendations of reinforcement of
bearings, shaft, the type of component its’ diameter and distance
between the centre of the component and the shaft collar is requested.
Painting : Casting surfaces are painted with linear
epoxy primer both internally and externally. External cast faces are
finally finished with PU blue Coatings, which is resistant to dilute
acids and alkalis, oils and solvents, sea water and temperatures upto
140oC.
EFFICIENCY
The efficiency of the gearbox is primarily a function of reduction
stages and type of gearing and is broadly as under when loaded to
rated capacity.
|
Type and reduction Ratio |
Effeciency |
Center distance |
Reduction Ratio |
|
Horizontally signal stage |
98% |
100-400 mm |
1.83:1 to 8:1 |
|
Horizontally double stage |
96% |
250-1000 mm |
8.23:1 to 48.57:1 |
|
Horizontally triple stage |
94 % |
400-1250 mm |
31.5:1 to 160:1 |
|
Vertically triple stage |
93% |
250-600 mm |
14.85:1 to 33.4:1 |
Optional Features: - Non standard ratio
Housing in cast steel or fabricated steel
Reinforced bearings for external loads,
Shaft extension input/output
Fan cooling or cooling coil
Integrals tooth male clutch with output shaft
|