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to individual component buying includes:
technically advanced design
no unpleasant surprises or assembly problems
all components are assembled and checked prior to despatch
single source rather than multiple suppliers
less paperwork saving time and money
guaranteed system quality
reduced lead time
The sea of gold – propeller finishing. Destroyer escort
propellers manufactured from nickel aluminium bronze
The end result is spectacular!
Fremantle Port Authority Safety Vessel fitted with VEEM
propulsion
Controllable pitch propeller
MATERIALS
Propellers are offered with a variety of material specifications,
including aluminium, manganese bronzes, nickel aluminium bronzes
(NiBrAl) and stainless steel.
While aluminium and manganese bronzes offer less expensive
options for general use, nickel aluminium bronze offers increased
strength and reduced drag due to thinner blades. Nickel aluminium
bronze provides excellent resistance to corrosion, errosion and
fatigue, while being easily repairable. Our Foundry Division is able
to alloy all of its own metals using our NATA (National Association of
Testing Authorities) certified laboratory to provide chemical analysis
to assist in meeting any material specification required.
DYNAMIC BALANCING FACILITIES
Dynamic balancing is integral to VEEM’s propeller manufacturing.
Propellers are balanced to a very high standard using either ISO
1940/1 G2.5 or G6.3, and all propellers that leave VEEM have a balance
certificate on record. Dynamic balancing is particularly important
for high speed vessels to ensure that our high performance designs
are accompanied by excellent smoothness.
PROPELLER REPAIR SERVICES
In addition to its manufacturing capabilities, VEEM offers repair
and refurbishment services for fixed pitch and controllable pitch
propellers. During periodic servicing, propellers are sent to VEEM for
de-fouling, cleaning and inspection and the propeller is returned
to an as new condition. Depending on client requirements, the
propeller may be completely checked for profile and dynamically
balanced prior to being fitted to the ship.
PROPELLER BALANCING NOTES
Caution must be taken when balancing marine propellers due to the
critical nature of blade cross sections, and the effect that this has on
thrust (dynamic load) during operation. When balancing propellers,
the allowable residual unbalance as defined by ISO 1940/1 should
be calculated by taking into account shaft bearing spacings and
propeller added mass (due to entrained fluid).
As propellers are generally balanced between machine pedestals,
but operate as an overhung rotor, the allowable unbalance is
commonly miscalculated.
Of major concern is that by far exceeding the required balance
standard, vibration can be introduced due to the effect of dynamic
forces generated by distorted blade profiles. This introduced
vibration greatly exceeds any benefit gained by reducing the
unbalance in air. This provides a sound reason as to why balance
standards for marine propellers should not be exceeded.
6
VEEM has NATA certification for dynamic balancing up to 28 tonne – refurbished GE
gas turbine rotor
A VEEMStar ® propeller being balanced in one of
VEEM’s 7 balancing machines
DYNAMIC BALANCING CAPABILITIES
The capabilities of the balancing division which is equipped with 4
Schenck and 3 CEMB balancing machines includes:
Dynamic Balancing - 100grams to 28,000 kg. 3.5 metres in diameter
and 12 metres long.
Static balancing - 100grams to 28,000 kg. 7 metres in diameter and
12 metres long.
General Balancing of - Propellers, fan and pump impellers,
centrifuges, turbines, wheel hubs, machine spindles, brake drums,
electric armatures and rotors, gyroscopes, rollers, beaters etc.
Engine Balancing - dynamic balancing of all engine components
for all currently available engines from single cylinders to V16 Alco
diesels.
Driveshaft Balancing - of all marine, industrial, automotive,
agricultural, transport and earthmoving power takeoff shafts.
ISO 1940/1 DYNAMIC BALANCE QUALITY GRADES
G16 Drive shafts, engine components, engine
crankshafts
G6.3 Marine main turbine gears, pump impellers,
electric armatures
G2.5 Gas and steam turbines, turbo compressors,
computer memory drums
G1 Grinding machine drives, small electric armatures,
phonograph drives
G0.4 Gyroscopes, Spindles, precision grinders
NATA CERTIFICATION
VEEM is certified for dynamic and static balancing by the National
Association of Testing Authorities and is controlled under an ISO
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