For Germany - based construction firm Kafril Group, durable components and reliable suppliers are crucial to maintaining its modified Hitachi ZX 870 - 3 XXL, a high - boom excavator equipped with a 50 - meter telescopic arm. This excavator is unofficially named "Beast of the East" due to its location near Leipzig, Germany, and its role in heavy - duty industrial demolition. Markus Kubaile, the technical manager of Kafril, turned to the Expander pin system to upgrade the pivot pins of one of the country's largest construction excavators.
" It is vital that our machines can be effectively maintained even in the event of major failures. This includes having reliable spare parts suppliers and our on - site service team being able to carry out repairs on site," Markus stated.
The "Beast of the East" is deployed on projects across Germany and sometimes even further afield. As a result, it can be challenging to find local service providers capable of working on such a specialized machine. However, uptime is a matter of maintaining competitiveness for the group, which is particularly important in unpredictable market conditions. Kafril not only needs to meet customer expectations for safety and reliability in some of the most demanding demolition work, but also has to operate within increasingly tight deadlines and ensure projects proceed on schedule. Therefore, achieving good results depends on minimizing failures as much as possible.
With a major workshop overhaul recently planned, Markus said Kafril has conducted a thorough renovation of the Hitachi excavator to enable continuous operation in the coming years without the need for major overhauls. " We are taking planned downtime now so that the machine can work for longer periods away from the workshop, and we are striving to minimize future wear and tear," he explained. The renovation work involved replacing the existing pivot pins with the Expander pin system.
The performance of pivot pins directly affects the machine's ability to complete tasks safely and efficiently. However, traditional pivot pins wear over time due to the gap between the hole and the conventional straight pin. For the "Beast of the East", the extreme height and weight of the equipment exacerbate the wear caused by the swing and movement of the telescopic arm, resulting in much higher stress than that on small - sized excavators.
By design, the Expander pin system eliminates the small tolerances required to install conventional straight pins into slightly larger diameter drilled holes. As a modular system consisting of a tapered shaft, expansion sleeve and various fastening components, the Expander locks from both sides when tightened, improving the stability of moving mechanical parts and extending the intervals between wear and maintenance.
Markus previously used the Expander pin system when repairing large Volvo machines. " At that time, I didn't know where this solution came from, but it was obvious that the wear degree of this component was much lower than that of standard pins," he said.
Three Expander pin systems have been designed for Kafril's machine, with the largest one having a diameter of 120mm and a length of 885mm. Michael Held, a sales engineer at Nord - Lock Group, explained, " The design of the largest Expander pin system is extraordinary. When the excavator switches between two special devices, the pivot pin must also serve as a ' hook extension ' to facilitate better storage and transportation of the boom."
Regular hook - shaped nuts require a tightening torque of 600 Nm, so a compact Superbolt multi - jackbolt tensioner has been added. Mathias Olofsson, product manager of the Expander pin system, said this tensioner " fits perfectly with the design". With the Superbolt, each small screw only needs a torque of 30 Nm to be tightened. " Therefore, we can complete the installation and disassembly of the entire pivot pin connection in a limited space without special tools," Markus noted.
Since the Expander pin system can also cope with existing wear in the pivot pin connection to a certain extent, Kafril can directly install the new pivot pins without the need for line boring and welding to restore the machine to its original tolerances. " If we had to restore the pivot pin connection first, we would need to arrange workshop time, transport the machine and completely disassemble the boom. We need to avoid these huge additional workloads," Markus said.
Instead, the Expander pin system can be installed directly on site, and Kafril's Hitachi ZX 870 - 3 XXL was quickly put back into operation. Before the team left for the demolition of a 45 - meter - long silo in Thuringia, Germany, Markus concluded, " If you want to keep the wear of the ear plates as low as possible, I suggest replacing the straight pins with the Expander pin system - preferably as original components installed by the manufacturer at the factory."
Your message must be between 20-3,000 characters!
