Correct machine operation, together with regular maintenance, significantly reduces undercarriage wear, improves operating efficiency and reduces running costs of tracked excavators, says Hyundai earthmoving equipment supplier HPE Africa.
“Because excavators have a strong solid steel construction, maintenance of the undercarriage is often neglected and this is an expensive mistake. Research shows that repair costs for the undercarriage of a tracked excavator account for as much as half of all repair costs over the life of the machine,” says HPE Africa MD Alex Ackron.
He explains that a worn undercarriage increases vibration levels of the excavator, which reduces the service life of components, like pumps, motors, electronics and the engine.
The HPE Africa technical team, after an investigation, has compiled a practical guide, where a few operational tips and a simple maintenance programme, can significantly extend the life of undercarriage components and reduce operating costs of excavators.
“What’s critical, is that the operator of a tracked excavator needs to apply different skills from operating a wheeled excavator, which is why operator training is so important,” Ackron highlights.
HPE Africa has seven operating tips to decrease undercarriage wear. The first is not to travel long distances in reverse, excavators are designed to travel with the idler at the front of the machine and the sprocket at the rear; travelling in reverse causes pin, bushing and sprocket wear.
Secondly, the company discourages travelling long distances in high-speed mode, as the faster the travel speed, the greater the relative load between components, which increases wear. Over long distances, friction causes heat build- up within the rollers, idlers and drives, which can damage internal seals.
Thirdly, travelling in high-speed mode on rough or hard terrain or inclines increases the impact with the ground. “An excavator does not have an independent suspension, which means that both tracks are stressed by an uneven surface. High impact causes damage to track shoes and increases wear on moving components.”
The fourth tip is to not dig or excavate with the boom over the sprocket. The overhead dig and dump cycle causes stress and wear at the point of the sprocket or bushing contact over the sprocket, these forces should be over the idler, where minimal chain rail wear occurs.
Fifthly, working up and down a slope is better than along a gradient or slope. Working along a gradient tilts the machine to one side, which increases the load/stress on the lower track and this accelerates overall wear on this track.
The sixth tip involves the balance slew direction under load. Because the dig-slew-dump cycle puts pivot stress on the undercarriage on the dump side of the machine, the operator should balance the slew direction by turning the excavator around in the middle of the shift.
Lastly, HPE Africa recommends trying to reduce pivot or counter rotation turns on hard ground. Excavators are useful on restricted work areas because they are able to make pivot turns, but the operator should try to make wider turns to prevent grouser corner wear.
In conjunction with the correct operation of the excavator, it is important to introduce a planned maintenance programme. HPE Africa recommends four maintenance steps be taken to reduce undercarriage wear.
The step involves removing packed debris and dry material from the undercarriage daily, checking track tension daily, inspecting the undercarriage weekly and having an undercarriage specialist check the undercarriage after every 1 000 hours.
“It’s also important to look at parameters of the excavator, like total hours of travelling compared with digging and total hours travelled in high-speed mode instead of low-speed mode,” says HPE Africa. Torque settings on all the bolts on the undercarriage should also be checked, including roller and top idler brackets, track shoes, sprockets and final drives.
HPE Africa offers a critical support service for Hyundai earthmoving equipment which encompasses an original-equipment manufacturer parts, repair and maintenance facility. Maintenance programmes are carried out in line with planned downtime schedules and operator familiarisation courses ensure the best performance and extend the life of every machine.