Loss of power is a loss of money and with energy costs on the rise, the need for power transmission systems performing at optimum efficiency is more critical.
Hanson, one of the world’s leading heavy building materials companies, was faced with a problem at one of its large quarries.
{{image1-a:l-w:300}}Hanson had a cone crusher drive system, comprising twin 150kW motors, with two worn belts and pulleys, that required replacement. The machine was fitted with 8V pulleys, a non-standard line of product in Australia with cost and availability being prohibitive, ie they require custom manufacture in Australia or need to be imported from the USA.
Gates Australia recommended changing the system to the popular SPC style belts; this allowed for common off the shelf pulleys and belts to be used. SPC is a smaller cross-section than 8V but the Gates SPC Predator belt can meet and often exceed the power capacity of the 8V drive.
The higher power density of the Kevlar-corded V-belts in the SPC Predator belts provided a cost-effective solution.
The old drive was as follows:
Power = 150kW @ 990rpm x 2 motors
Driver pulley = 6/8V570
Driven pulley = 12/8V625
Original belts = 12 x 8V1600
The new drive system is as follows:
Driver pulley = 4/SPC560
Driven pulley = 8/SPC630
New belts = 8 x SPC4000P Gates Predator
After consultation with a Gates engineering expert, it was recommended to use the 8 Gates Predator SPC4000P belts accompanied with three relevant sized pulleys.
{{image3-a:l}}The new drive was less than half the price of the replacement old 8V style set-up, making the new SPC Predator drive an extremely cost-effective solution for the customer. Based on the pricing difference and increased capacity, the quarry manager very easily made the decision to install the new Predator drive.
The new SPC Predator drive has 118kW extra capacity which means shock loads and faster crushing are easily dealt with; even the tonnage throughout was increased on this particular crusher.
The new Predator drive has been running without problems since the start of 2008 with the same set of Predator belts. Jam-ups are less frequent due to the Predator belts holding tension and continuing to drive.
The solution provided the customer with a Predator drive design that is a more compact drive by 40 per cent (213mm vs 355mm), weighs less (102kg vs 206kg), puts less strain on other components, and uses fewer belts. This equates to cost savings with greater efficiency.
SAVINGS WITH COMPACT DRIVES
Predator V-belts can handle 1.4 to 2.2 times more power than the equivalent size standard V-belt. So you can design a more compact drive that weighs less, puts less strain on costlier components, and uses fewer belts, all of which saves money. The difference is outlined in Figure 1.
{{image2-a:r}}Compared with a standard V-belt drive, the more compact Predator drive provides equal or greater power capacity in nearly half the width and the weight at a third of the cost. Gates Predator belt drives have proved themselves in the toughest applications in agriculture, forestry, mining, construction and manufacturing.
The benefits of the Predator drive rubbers are outlined according to the numbers below:
1. They reduce friction and heat build-up under shock load with abrasion and puncture-resistant bareback (non-rubber) double layer fabric cover.
2. There is minimal need for retensioning due to stronger than steel Kevlar tensile cords that reduce belt stretch by 50 per cent over standard V-belts and provide extraordinary strength and durability.
3. There is a high quality chloroprene compound body specifically engineered for Predator belts, providing oil and heat resistance; rated for 82?C, it out performs other rubbers in harsh operating conditions.
4. They extend drive life with the patented curved sidewall that allows the belt to enter the pulley groove cleanly and smoothly, reducing sidewall wear on belt and pulley. The patented concave sidewalls provide a better fit in pulley for uniform loading and maximum life. They reduce friction and heat build-up under shock load with an abrasion and puncture-resistant bareback (non-rubber) double-layer fabric cover.
5. The multiple-layer tie band joins belts together into a Predator PowerBand that provides lateral rigidity for reduced vibration and belt turn-over on multi-groove pulleys.
The Strands are precision matched to maximise power absorption and belt life, especially on longer belts (PowerBand construction).
Source: Gates Australia