The Baldor•Dodge Vertical Gearmotor (VGM) offers an alternative to common vertical pump drive technologies, which utilize large, high-pole-count vertical motors or a combination of a horizontal motor with a right-angle gear reducer. Built on a standard low-pole-count motor platform utilizing proven gear technology from the Baldor•Dodge portfolio, the VGM can have significant benefits when compared to these other pump drive systems.
Using a standard low-pole-count motor platform results in a solution that has a smaller footprint and is lighter than traditional pump drive systems. Weight differential depends on the application but is typically 10 to 30 percent less, which reduces support structure and facility costs. The ability to use a lower-pole-count motor also offers a significant cost savings opportunity over high-pole-count motors. Utilizing the reducer to accommodate thrust loading is more cost-effective than designing this functionality into the motor. The use of standard 4-6 pole motors also increases availability.
Lower-pole-count induction motors offer higher efficiency ratings and power factors than high-pole-count induction motors. A higher power factor equates to more efficient use of electrical power and less reactive power drawn by the system. By using the specific gear reduction ratio required for a given application, VGMs provide the exact output speed needed. Setting the proper output speed means a more efficient design with higher reliability and maximum pump performance. Lower vibration levels, decreased radial and axial loads, optimal discharge pressure, reduced maintenance, and improved reliability are all advantages of setting the proper pump speed.
The startup and shutdown sequence of a pump system is often the most demanding condition in the operation of the pump. The resulting hydraulic transient waves create stresses much greater than those experienced by a pump during normal operation. These unstable conditions caused by uncontrolled starts can reduce the pump life by 50 percent. Historically, the only methods used to reduce hydraulic instability during startup have been utilization of control valves to slowly prime the system or the use of variable frequency drives.
Proven Baldor•Dodge technology now offers a better way. Using an optional, hydroviscous clutch, the motor is brought to full speed unloaded, then the pump is slowly engaged using a simple, mechanical, Controlled-Start Transmission (CST) system.
The Baldor•Dodge Vertical Gearmotor product line is available in six sizes for vertical pump speeds from approximately 100 to 500 RPM. The VGM has torque ratings from 550,000 to 7,000,000 in-lbs. and approximate power ratings of 750 to over 25,000 HP, depending on output RPM.
Baldor Electric Company is an exhibitor at WEFTEC.15 and can be found at Booth 2025. For more information, visit www.baldor.com
