BMG encourages and assists customers to adhere to stringent safety legislation during bulk handling. “Tsubaki back-stops 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,” explains Carlo Beukes, Business Unit Manager, BMG’s Power Transmission division.
“Local safety regulations require 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, to prevent injury by materials falling from a conveyor belt.
Reverse rotation
“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. Apart from the mining sector, cam clutches are used for belt conveyors for materials handling, metals, timber, pulp and wood chip, 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,” adds Carlo.
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: overrunning, indexing and backstopping.
Races
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 excellent concentricity and a special surface finish to obtain accurate cam rotation. Cams are manufactured from special selected high alloy steel, with a hardness option up to 2 500Hv.
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 and bucket elevators used in the mining and bulk handling sectors.
Narrower width
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.
Higher backstop torque
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.
Added to this, 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.
Oil leakage
A common cause of conventional backstop failure is oil leakage. Tsubaki has eliminated this risk in the BSF 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 EP-free grease for easy and effective maintenance of the BSF series. The BS-Grease is available from any BMG branch.
Extended service life
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 minimises internal friction and reduces 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.
For extended service life, correct lubrication methods and dust prevention care are critical. BMG recommends the use of a maintenance kit and Tsubaki-approved EP-free grease for easy and effective maintenance of the BSF series.
Speedy delivery
BMG has made a substantial investment in local Tsubaki backstops to ensure speedy delivery. This is a major advantage, as the current industry norm is up to 24 weeks delivery.
The complete range of Tsubaki power transmission components is available from BMG’s national branch network, which offers a technical advisory and 24-hour back-up service.
