Mechanical Technology July 2016

⎪ Power transmission, bearings, bushes and seals ⎪

hydraulic torque tools.

balance rotors to a high accuracy improves vibration levels, thereby increasing reliabil- ity while reducing customer maintenance costs. Marthinusen Coutts, a division of Actom, operates the third largest high- speed dynamic balancing machine in sub-Saharan Africa. Mike Chamberlain, marketing executive at Marthinusen & Coutts, says the advanced machine is in constant use with local OEMs benefitting tremendously by having access to an in- dependent balancing service of this quality and capacity. The 32 t Schenck HM7 U/S balanc- ing machine is located at Marthinusen & Coutts’ 9 500 m² high tech workshop in Cleveland, near Johannesburg. The HM7 U/S balancing machine is 9 000 mm long and has a measuring range between 100 and 5 000 rpm. It has a journal size of 400 mm and a swing of 2 400 mm. It is fitted with a CAB 920 H measur- ing instrument with a vector display. Its state-of-the-art technology makes changeovers to new rotor types quick and straightforward. “The machine facilitates the balancing of all larger high speed rotors dynamically at full operating speed and sometimes, depending on the design of the rotor and customer requirements, at 10% over- makes the bolt self-locking. Advantages of this re-usable system include maximum safety when locking fasteners, easy assembly and disassem- bly, positive locking at low or high preload levels and minimum surface marring or scratching. This system, which has the same temperature characteristics as a standard bolt or nut, resists loosening caused by vibration and dynamic loads and the locking effect is not affected by lubrication. For a permanent, guaranteed clamp application, BMG recommends Huck structural rivets and lock bolt solutions and for extreme temperatures and chal- lenging environments, the Thome and Schwind range of specialised fasteners is recommended. For high strength challenges, the Nord-Lock Superbolt multi-jackbolt tensioner system, with advanced bolt- ing technology, only requires simple mechanical torque tools for installation, eliminating the need for high strength

To achieve the optimum clamp, BMG offers Gedore mechanical torque hand tools, as well as Atlas Copco and Ingersoll Rand pneumatic and electronic assembly tools, which use clutch and trans- ducer technology to measure and control tightening torque. It is also possible to record all joint tightening procedures performed to ensure optimum clamp in safety and quality critical applications.

Above: Thome and Schwind high quality fasteners range from standard types to stainless steel and special nickel alloy materials for use in extreme conditions. Right: Huck Bobtail lockbolts offer up to 10 times the fatigue strength of conventional nuts and bolts and are suitable for heavy duty applications where ultimate vibra- tion resistance is critical.

Other products include hand and power tools, tool kits, personal protective equipment, locks and lockouts, lifting equipment and environmental products. The range also encompasses measuring and testing equipment, welding consum- ables and abrasives, as well as cutting and workshop equipment. BMG’s network of over 120 branches offers a technical advisory and support

service to ensure the correct product is selected for each specific applica-

tion. The company’s advanced fastening solutions and instal-

lation tools are designed to meet the requirements of quality and safety critical installations, also ensuring the best total cost of ownership. q

OEMS rely on rotor balancing capacity L eading local repairer of rotating electri- cal equipment, Marthinusen & Coutts says its in-house ability to precision

28 MW compressor motor required by a leading local steel producer. Marthinusen & Coutts provides this crucial service to the power generation industry, balancing both high pressure and low-pressure turbines. The division has also partially (low speed) balanced generator rotors up to 60 MW where the rotors are subsequently trim-balanced at full speed on site, once the rotor has been installed. “It goes without saying that the service has obvious time and expense advantages for those making use of it,” Chamberlain concludes. q

speed,” Chamberlain says. All rotors are balanced in-house which speeds up the process and reduces costs with the service being available to external customers on a first come, first served ba- sis. The machine is operated by one of the country’s top balancing machine experts in line with international best practice with industry standard balancing certificates be- ing issued for each completed rotor. The largest rotor balanced at full speed to date was a 15-ton 4-pole rotor for a

The 32 ton Schenck HM7 U/S balancing machine is located at Marthinusen & Coutts’ 9 500 m² high-tech workshop in Cleveland, near Johannesburg.

Mechanical Technology — July 2016

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