The Mine Health and Safety Act (MHSA) states that the installation of incline conveyor belts must include the fitting and use of one or more devices to prevent run-back or run-on, preventing injury by materials or minerals falling from a conveyor belt, says engineering components supplier Bearing Man Group (BMG) power transmission product manager Carlo Beukes.

“Japan-based roller chain manufacturer Tsubakimoto Chain Company’s (Tsubaki’s) back stop cam clutches designed for safety in high- or low-speed applications meet the requirements of this legislation,” he adds.

BMG is encouraging and assisting the mining sector to adhere to the MHSA. The company’s technical team advises mining companies on the correct cam clutch for each application and the appropriate installation and use for optimum performance and improved safety standards.

For extended service life, correct lubrication methods and dust prevention care are also critical.

Tsubaki cam clutches are available from BMG in different capacities and styles designed to provide the best functional characteristics for three basic modes of operation, namely overrunning, indexing and back stopping.

“The outer and inner races of these cam clutches are manufactured from high-quality alloy steel, with high surface hardness and core toughness, to be able to withstand oper-ation in arduous conditions,” says Beukes.

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

The new BS-HS back stop cam clutch series has many critical features not found in conventional models. 
This range has an upgraded cam cage and bearing-supported design, which provides higher torque/speed capacity than other cam clutches.

Other advantages include the use of a smaller clutch, which provides cost savings, and high-quality clutch component parts made from heat-treated alloy steel that provides wear resistance and extended life performance, he says.

These back stop cam clutches also have an anti-roll-over cam design that ensures durability against heavy shock load in back stopping. The dust proof construction of this series, with the combination of a double lip oil seal and dust protective plate, keeps grease in and dust out.

Another important feature of the BS-HS series is reduced maintenance. It is standard practice to pack heat-resistant grease into the unit with only minimal maintenance required for the lubricant. This makes maintenance easier and significantly reduces operational costs, he adds.

Tsubaki back stop cam clutches are designedfor use in diverse applications, including contamination-free processes, high-temperature environments and wet, corrosive and dusty condition applications.

Apart from the mining sector, these cam clutches are used for belt conveyors for handling metals, timber and pulp and wood chips, as well as for bucket elevators for cement and grain. These units are also installed to enhance performance of large drift conveyors and screw pumps.