Combination Drives
A Combination Drive is known for complete reliability and for such
operations that require complete reliability Combination Drives are the
number one choice.
Combination gear drives give the users the leverage of operating pumping
system with two alternate power sources. In case of a power failure or for
example say a motor failure, the drive can be converted simply for an engine
or turbine operation. Though the combination drives can come in with solid
or hollow shafts, normally a hollow shaft (vertical) electric motor is
mounted on top of combination gear drives. Between an electric motor and
gear drive, a coupling is positioned on the pump head shaft. The function of
the coupling is for disconnecting the gear drive from the system in case of
electric motor operating the pump. It is on the design of the coupling that
the change over system from electric to engine power is automatic or manual.
Advantages of Combination Drives
- Flexibility of Operation : In combination drives, as the
engine is activated to power the pump, the coupling rotates the electric
motor and pump treating it as one. The electric motor carries the thrust
of the pump, as the pump adjusting nut is placed at the top of electric
motor. This gives the Combination gear drives the flexibility to
function with or even without thrust from the pump.
- Special Design : In combination gear drives the automatic or
manual couplings have an unique design. This design allows maintaining
the pump head shaft alignment centered under all types of operating
conditions. Thus there is elimination of the problems of pump head shaft
whip and vibration.
Installing of Combination drives
- The gear drive is to be placed on the pump discharge head. It is then
to be aligned with engine. It is vital to secure it properly with bolts
of correct size.
- The motor stand guard is to be removed from the motor stand (please
refer image).
- Screws holding the drive sleeve cover is to be removed to drive
sleeve (please refer image).
- The drive sleeve cover is to be lifted with sliding clutch, bearing
bushing and also steady bearing, off the gear drive. If it is equipped
with non-reverse pins, it will remain in the drive sleeve. However the
non-reverse pins are to be removed from the drive sleeve if there is no
need for non-reverse feature in the gear drive.
- The drive sleeve cover needs to be fitted carefully with the bearing
bushing, steady bearing and also the sliding clutch found on the
headshaft. The sliding clutch as well as the bearing bushing should be
made to slide freely on the headshaft.
- Then the gib keys are to be fitted properly in the bearing bushing
and the sliding clutch.
- With the installation of the combination clutch components the head
shaft should be slided through the gear drive. Attention is to be given
so that the oil tube is not hit, that is placed on the bottom of the
gear drive, at the end of shaft.
- The top shaft and the pump shaft is to be coupled. While installing
the electric motor, the motor manufacturer's instructions needs to be
followed.
- At this juncture two things are to be given attention(a) the
combination clutch components should remain to slide freely on the
headshaft (b)There should be plenty of keyway length in the headshaft
for providing a full depth keyway under both the gib keys.
- The drive sleeve cover is then to be aligned on the drive sleeve
(please refer image) and the cap screws to be tightened alternately.
This is done to make sure the drive sleeve cover is pulled in the
downward direction squarely.
- Then the sliding clutch is to be slided into a position as
illustrated with the safety pins installed. Next the set screws is to be
tightened over the safety pin as well as the gib key located in the
sliding clutch.
- Finally the guard in the motor stand needs to be installed.
