The two bearing types in the New Generation pump have been chosen on the basis of load carrying capacity in relation to the loads to be carried and the requirements regarding life and reliability.
A precision double row angular contact bearing is used for the top bearing. The 32 degree contact angle gives the bearing a high load carrying capacity and makes it suitable for heavy radial and axial loads in both directions.
A modern “State of the Art” cylindrical roller bearing has been chosen as the lower bearing. The contact geometry between the roller and the raceway and the optimised surface finish have considerably increased the performance of these bearings in comparison to conventional bearings. The modern design of these bearings offers much greater load carrying characteristics than traditional design. The inner bearing ring can be withdrawn from the outer ring which facilitates the mounting and dismounting of the shaft assembly into the bearing housing.
The high tensile 50mm diameter CNC machined shaft is incredibly strong and has been machined to a very high dimensional and form accuracy. Very low vibration levels and low operating temperatures are attained with this “heavy duty” shaft. Precision machining enables extremely accurate interference fits of both bearings onto the shaft. No individual bearing adjustment, shimming, measuring or adjustment procedures are required for assembly.
Choosing the right bearing grease for a certain application is critical to bearing performance. The use of an SKF LGHP 2 grease ensures smooth trouble free operation and maximum reliability even under the most extreme conditions. It helps prevent contamination from penetrating the bearing, cushions any shock loads and protects against corrosion.
LGHP 2 grease operates over a wide temperature range, has low noise characteristics and very good mechanical stability. Replenishment of grease should be by means of a hand held grease gun.
Two heavy duty resilient rubber gaskets are fitted to the pump and act like a shock absorber by allowing the casing to deflect with respect to the impeller. This allows stones and other solids to pass through the pump and reduces shock loading to the bearings.
IMPELLER & CASING
Both the impeller and casing are manufactured from heavy duty SG iron. The unique design of the impeller ensures that there is no need for any seals or bearings to be submerged in the liquid. Heavy duty vanes allow the pumping of solids and provide outstanding resistance to wear. Vanes on the top side of the impeller prevent material accumulating and the pump binding up or blocking. Simple external casing adjustment allows for easy casing adjustment to restore original pump performance without having to dismantle the pump.
Motors that are MEPS (Minimum Energy Performance Standards) approved are used on all NUMEDIC Effluent Pumps. All MEPS motors are highly efficient and have passed the AS/NZS Standards level 1359.5. All motors use quality deep groove ball bearings and are pre-packed with grease.
Motor covers are supplied with all NUMEDIC New Generation pumps to ensure a reliable and long motor life.
NUMEDIC chopper blades have been designed to help chop up “stringy” difficult to pump materials. They are very effective and do not require any extra power to run.