The Motorized Pulley was first produced in 1953 specifically for use on conveyors belt applications. A motorized pulley is a compact, hermetically sealed, highly efficient conveyor drive unit that would be unaffected by dust, water, oil, grease or other harmful substances. A Motorized Pulley that would be quick and simple to install and require virtually no maintenance.
These aims were achieved and today the motorized conveyor pulley is considered to be one of the most reliable, effective and safe conveyor drive systems available throughout the world. The Motorized Pulley is a highly efficient geared motor drive, which is hermetically sealed in a steel cylindrical shell. The shell, which is normally crowned to ensure belt tracking, is fitted with bearing housings incorporating precision bearings, double lipped oils seals and rotates on a pair of shafts.
The motor stator is fixed to the shafts and the motor winding cables passes through one of the shafts, eliminating the need for slip rings and brushes. The squirrel cage induction motor, manufactured in steel laminate, is machined concentric to high tolerances and designed to give a strong starting torque for 3 phase versions. The rotor pinion is coupled directly to the gearbox. The gearbox transmits torque to the shell through a geared rim and provides a highly efficient motor, with very little frictional losses. The Motorized Pulley is oil filled, which acts as a lubricant and coolant. Heat is dissipated through the shell and conveyor belt. All components are manufactured using the latest technology.
Motorized pulleys are widely used in industries of mining, port, metallurgy, aggregate, sand, cement, grain, power, food, sugar, etc.
Belt Conveyor Motorized Pulley
The Motorized Pulley has been specifically designed for belt conveyors. Totally enclosed The motor, gearbox and bearings are totally enclosed and sealed inside a steel shell; therefore they are unlikely to fail due to harmful environmental conditions such as water, dust, grit chemicals, grease, oil,etc.
Because the drive unit and the bearings are mounted inside the Motorized Pulley shell, it takes up much less room than a conventional drive. No need for costly extras like chains, v-belts, couplings, bearings, support structure and special guarding.
The Motorized Pulley is probably one of the safest drives available because the motor is completely enclosed and the external shafts are always stationary. The only moving external parts are the Motorized Pulley shell and bearing housings. Low purchasing and installation cost The Motorized Pulley is quite often less expensive than exposed drives because it has fewer parts. Therefore less conveyor design and parts purchasing costs. It is also much quicker and easier to install - certainly less than a quarter of the time taken to fi t an exposed system.
The end user also benefits from the Motorized Pulley, because it requires no maintenance other than the recommended oil change every 20,000 hours. In other words almost 10 years between oil changes based on an 8-hour/day working week. Synthetic oil can be specified to extend the service range up to 50,000 hours.
The Motorized Pulley usually has a much higher efficiency from electrical motor to shell (Pulley face) than conventional drives, because it has fewer frictional losses, and therefore mechanical efficiencies of up to 97% can be achieved.
Because the Motorized Pulley is hermetically sealed it cannot contaminate any conveying materials such as food, electrical components, plastics and other materials that must be kept perfectly clean during handling.
If installed correctly the Motorized Pulley always looks good. Due to its compact size and smooth lines, quite often the Motorized Pulley is out of sight, because it is hidden within the conveyor frame.
All three phase Motorized Pulleys are protected by our thermal protection switch. This heat sensitive switch is built into the motor windings to protect the motor from overheating. The thermal protector must be connected to a normally closed circuit.
Often the Motorized Pulley is lighter than conventional drives and often it is possible to reduce the cost of the conveyor structure, because the weight is evenly distributed within the conveyor frame.
All Motorized Pulleys with 3 phase motors can be easily controlled by variable frequency converters. For further details we refer to the technical descriptions at the end of the catalog.
A Motorized Pulley consists of the Motorized Pulley and two fixing brackets! Exposed drives can require up to eight or more separate components, most of which have to be purchased from different suppliers or custom manufactured.
Thanks to the totally sealed enclosure and high quality gears the Motorized Pulley runs almost at a whisper – a very important fact in today’s modern factory environments. However, for some special application, a lower noise level could be required.
The Motorized Pulley – the ideal drive unit for conveyors “Fit it and forget it”.
Lagged Motorized Pulley for Belt Conveyor
For low temperatures below –25°C please consult SKE. Special oil, special seals, and possible anti-condensation heater may be required. Re-greasable seals to avoid drying out the labyrinth seals.
For high ambient temperatures above +40°C please consult SKE.
IP6X re-greasable seals, special fi nish, e.g. stainless steel – AISI 303/4 or even AISI 316, semi-rust-free, special coating, rubber lagging.
Re-greasable seals; Stainless steel versions for high pressure and chemical wash down; food grade oil and grease; Food quality rubber lagging being oil, fat & grease resistant. FDA, USDA, FSIA & FESD recognized materials.
Electromagnetic brake. Special shafts prepared to fi t an external brake - 500H-1000HD.
Suffi cient time delay between forward and reverse. The Motorized Pulley must come to a complete stop before reversing.
AC frequency converter.
Use drives only from a special range of Motorized Pulleys developed for this purpose. Do not use standard Motorized Pulleys unless accepted by SKE. Insulation class H, extra oil. Connect thermal protector.
Special execution! Please consult SKE. Extra oil, grease packed top bearing.
• To be re-positioned to the opposite end
• To be positioned at the top when installed.
Over-sized Motorized Pulley.
To reduce the starting current it is possible to use starting devices such as star/delta starter, electronic soft starter etc. Please be aware that, when connecting a star/delta switch, the power of the motor will drastically be reduced and could cause overheating of the motor. If full torque is required during start a soft starter with torque boost should be used. SKE Motorized Pulleys can be used in many dust-prone areas. For your specific application, please contact SKE technical office for approval of suitability.