Committed to ensuring optimum safety standards in all sectors, mining and industrial equipment supplier BMG encourages and assists customers in adhering to stringent safety legislation during bulk handling, ensuring that appropriate measures are taken to prevent roll-back incidents, which might cause injury to workers during conveying operations.

Local safety regulations require incline conveyor belts to use one or more devices to prevent run-back or run-on, to prevent injury by materials falling from a conveyor belt.

“Tsubaki backstop cam clutches are designed to prevent reverse rotation of drive shafts, offering a simple and cost-effective means to protect capital equipment and enhance safety,” says BMG power transmission division business unit manager Carlo Beukes.

In this regard, BMG technical experts advise on the selection of the correct cam clutch for each application and assist with proper installation methods to ensure optimum performance and improved safety standards.

“Tsubaki backstops and cam clutches, which have been developed and manufactured in Japan for high efficiency and optimum safety in high- or low-speed applications, meet the requirements of current legislation,” he explains.

Tsubaki cam clutches, available from BMG in different capacities and styles are designed to provide the best functional characteristics for three basic modes of operation – over- running, indexing and backstopping.

The outer and inner races of these cam clutches are manufactured from high quality alloy steel, with high surface hardness and core toughness, to withstand operation in arduous conditions.

These races are precision ground, providing improved concentricity and a special surface finish to obtain accurate cam rotation, while the cams are manufactured from specially selected high alloy steel, with a hardness option up to 2 500 Hv.

A key range in BMG’s portfolio of Tsubaki cam clutches, is the BS-F series, which is suitable for high-speed inclined and long overland belt conveyors, as well as bucket elevators, used in the mining and bulk handling sectors.

The high-torque, high-speed Tsubaki BS-F series, with a narrow width I-beam torque arm, is a drop-in replacement to conventional roller-ramp devices. This allows for quick and easy on-site installation and enables effortless replacement of an old backstop with the new BS-F design, without the need for modification to the existing layout.

Although this series has a narrower width than other models, the downsized unit exceeds the requirements of high-speed inclined belt conveyors, with the benefits of space-saving and reduced installation time.

Important features of this series include a non-rollover cam and roller design, which offers higher backstop torque capacities and lower running temperatures than conventional anti-rollback devices.

In addition, a flexible labyrinth seal mechanism prevents the ingress of dust and water in abrasive conditions and a double-lip oil seal and multi-temperature grease enable safe operation at a wide ambient temperature range, from -55 °C to 150 °C.

A common cause of conventional backstop failure is oil leakage. Tsubaki has eliminated this risk in the BS-F series by designing the backstop to operate with grease and a specially designed labyrinth seal. The absence of an oil level gauge creates a more reliable safety device.

For extended service life, correct lubrication methods and dust prevention care are critical. BMG recommends the use of a maintenance kit and Tsubaki-approved extreme pressure additive-free grease for easy and effective maintenance of the BS-F series.

The cam and roller cage orbit at low speed, continually conveying grease internally from the bottom to the top of the mechanism. The constant circulation of grease reduces internal friction and lowers operating temperature for dependable operation.

Maintenance intervals are between 7 500 hours and 8 000 hours and the effective service life of the units is also significantly extended compared with conventional oil-filled units.

BMG has also made a substantial investment in local Tsubaki backstops to ensure speedy delivery. This is a major advantage, as the current industry delivery timeframe is about 24 weeks.