RXC Series variants, Ring-cone product family
The NIDEC-SHIMPO Ring-cone has a strong advantage over the common electronic variable speed drives in certain performance aspects. The Ring-cone is a mechanical adjustable speed drive utilizing a ring and cone friction power train – hence the name. The internal drive assembly consists of an input disc, a set of planetary cones, a control ring, the cam disc and a pressure control cam. The Ring-cone has different sizes to handle motor power ranging between 1/4HP – 20HP, and nominal output torque ratings spanning 15 – 130,000 in-lbs. This unique drive provides a speed range of 0 – 800 RPM, and a cam mechanism that adjusts to the environment downstream and can withstand a certain amount of shock load.
With a variable frequency drive, the output torque remains constant from base speed down to the lower limit, whatever it may be for the application. However, with the Ring-cone mechanical variable speed drive the output torque increases as the speed drops. At the low speed range, the output torque approaches 500% of the motor rating providing large breakaway torque values. The mechanical drive is also capable of handling a 200% overload capacity throughout the entire speed range. This performance advantage allows the user to set a low speed that can help the drive package push through difficult areas.
Ring-cone Torque Curve
Although VFDs have become the default solution for industry and rightfully so, the mechanical variable speed drives has its niche in specific applications – such as extreme pumping, mixing, recycling, etc. – where its mechanical advantage and low maintenance requirements are an excellent fit. It is ideally suited for rugged, trouble free service in the worst environments including explosion proof, chemical processing, and washdown applications.