Manufacturing: Dynamic Balancing
Dynamic Balance 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 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.
Dynamic Balancing Capabilities
The capabilities of the balancing division which is equipped with 4 Schenck and 2 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 shaft.
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 9001:2000 quality system.
Balancing Experience
Since its inception in 1968, the division has been a leader in the field of dynamic balancing and is equipped with modern, accurate equipment to meet the demands of its wide variety of clients. We are proficient in balancing to ISO 1940/1 and AS 3709 standards down to a quality grade of G1, where required.