A hydraulic breakthrough for tracked carriers

Hytec South Africa and Bosch Rexroth Germany joined forces to develop a hydraulic solution for Bell Equipment, which was designed to minimise ground compaction for the original equipment manufacturer’s tracked carrier range. This was combined with local and international field tests to deliver an optimal result.

Bell Equipment needed to ensure that its new TC 7 and TC 11 tracked carriers could perform optimally in soft underfoot conditions without negatively impacting the ground. The machines also had to be able to operate in environmentally sensitive areas where ground compaction is unacceptable.

Bosch Rexroth Germany assisted with the required system calculations and made useful recommendations regarding component selections of the hydrostatic drive system, including the prototype tandem drive pumps, motors and planetary reduction drives. In turn, Hytec ensured that the hydraulic drive component installation by Bell Equipment engineers was in accordance with Rexroth specifications.

Prior to prototype completion, extensive durability and performance tests (simulating normal operating procedures) were conducted at Bell Equipment’s Richards Bay factory. As the request for this specified equipment originated in the USA, extensive testing was also carried out on customer sites on American soil.

Bosch Rexroth products and components used in the TC range include: tandem closedloop pumps for oil flow and drive pressure; variable displacement piston motors to drive the tracks; and planetary reduction drives. These drives, when placed between the piston motor and track, multiply the delivered torque.

“Fine-tuning and optimisation were done by Bell Equipment engineers, in collaboration with Bosch Rexroth Germany’s engineers,” explains Berndt Wichmann, regional technical manager: KwaZulu-Natal, Hytec South Africa. “This teamwork helped to achieve optimal vehicle control and performance.

“Feedback from the intensive US test programme was encouraging,” adds Ryan Lombard, product designer for Bell Equipment. “It surpassed our expectations, with all features designed into the machine having proved themselves in the various applications.”

Hytec South Africa and Bosch Rexroth Germany developed a hydraulic solution for Bell Equipment that minimises ground compaction on their tracked carriers

Niche demand

Demand for this type of vehicle in the construction and mining industries stems from Bell Equipment’s American customers requiring a niche solution for soft underfoot conditions. This initiated extensive market research and, after a stringent design process, the development of the TC7 and TC 11 series. Each unit meets the needs for short-haul tasks in mining, construction, oil and gas, and the pipe-laying industries for work in soft underfoot conditions.

Hytec and Bosch Rexroth have previous experience with Bell Equipment in supplying componentry and helping develop hydraulic systems for a range of machinery used in mining, construction, agriculture and allied industries.

“We are now an official production partner to the Bell TC range, offering continuous support to machine production and the aftermarket, as well as technical and future product development support,” says Wichmann.