Off-road vehicles: the main faults in these assets

Off-road vehicles are assets used in various industrial sectors to ensure mobility and transport capacity in difficult terrain. These pieces of equipment are designed to transport heavy materials, excavate or move soil.

They can also be used for drilling tunnels, pits or foundations. The operation of these machines takes place in environments that are difficult to access or in very rugged and isolated areas, usually far from the urban road network. These assets, unlike normal vehicles, have a robust structure, providing durability, short work cycles and mechanical availability.

Here are some of the segments in which off-road vehicles are widely used.

Off-road vehicles in the mining industry

In the mining sector, one of the main aspects of cargo transportation is density. Because of this, the trucks and other off-road vehicles used in this segment need to be prepared to operate on uneven and steep terrain, carrying very heavy loads, without this affecting their integrity or the safety of the drivers. Mining roads have the right characteristics for off-road trucks to operate efficiently and safely. As these are trucks with a capacity of up to 186 tons, the roads must have more open curves.

Off-road vehicles in the timber industry

Just as in mining, the off-road vehicles used in the timber industry also transport heavy loads in rough environments. It is not uncommon for trucks in this segment to be operated on poorly compacted soils.

Off-road vehicles in the construction sector

Sometimes work takes place outside urban areas, or even in places where there is dust, rough topography or roads in critical condition. As a result, the engine of an off-road vehicle needs to be robust enough to operate and meet the demands of the high torque required in these circumstances.

Characteristics of off-road vehicles

Off-road vehicles generally have four-wheel or track drive to ensure stability and maneuverability in adverse terrain. Another important point when talking about off-road vehicles is energy efficiency. This is because these vehicles use around 50% of their energy to carry their own weight. As a result, the cost of operating this equipment is high, as it requires a large amount of energy to operate.

Off-highway vehicles are distinguished from road trucks by their specific structure in the buckets, boxes, tires and axles, allowing them to carry loads of between 25 and 400 tons, depending on the model. These vehicles stand out for their load capacity and engineering adapted to withstand heavy weights, with components designed to operate under these conditions, including more resistant cast parts, which make the structure more robust and require less frequent replacement.

Off-road trucks can have rigid or articulated chassis. Those with rigid chassis usually have rear-wheel drive and are ideal for moving on well-maintained roads. Trucks with articulated chassis, on the other hand, have all-wheel drive and are able to move in different weather conditions, on roads with poor access and up to 35° slope.

These vehicles also have a centralized lubrication system, so that all points receive the correct dosage without the need for professional intervention. Tire calibration is also fundamental to the operation, as an empty tire can raise the working temperature, leading to carcass separation.

Challenges in maintaining off-road vehicles

As with any industrial asset, the key to ensuring that equipment is always working properly is the continuous monitoring of health indicators. However, in the case of off-road vehicles, this proves to be a very difficult task. But why?

Difficulty of access: The structure of an off-highway vehicle, be it a truck, excavator, drill or other type, is generally quite closed and protected, ensuring the robustness of the equipment. Other points are at height. All of this makes the manual data collection process difficult and often leaves points inaccessible for data reading. In this case, Dynamox’s remote sensing solution offers security, as the professional does not need to be close to the asset to take the readings. Dynamox vibration and temperature sensors continuously monitor the health indices of these assets without the need for a professional nearby. In addition, the devices are IP66 / IP68 / IP69 / EX certified, further contributing to the safety of operations.

Exposure to risk: Due to the size, load and constant transit of these vehicles, as well as other factors, the inspection activity can expose inspectors to risk. In addition, in order to collect some information, such as vibration data, the vehicle must be in operation.

Standardizing collection: Another challenge in monitoring off-road vehicles is to standardize collection, so that the data is valid for comparison and follow-up.

Failure modes in off-road vehicle components

Combustion engine failures

This component is responsible for transforming thermal energy into mechanical energy, providing the driving force needed for the asset to function. The failure modes observed are:

• Oil filter: A clogged or broken oil filter can also be one of the causes of combustion engine failure, as its function is to prevent impurities from damaging the engine.

• Fuel filter: Leaks or blockages in the fuel filter can cause problems with the engine, greatly increasing the vehicle’s fuel consumption.

• Air filter: Problems with this element, such as blocked or poorly attached hoses, can be one of the causes of engine failure. This filter is essential for the health of the engine and, when not operating correctly, can cause it to lose its efficiency.

Battery failures

This component is responsible for generating power for the vehicle’s other electronic components. The most common failure mode linked to this component is discharging, preventing it from starting.

Cooling failures

As the component responsible for regulating and controlling the engine’s temperature, it can fail when the coolant is low, or when there is damage to the hoses, whether due to clogging, wear or poor fastening, or when there is damage to the water pump.

Service and rear brake failures

It is a fundamental component whose function is to reduce the speed of the vehicle or keep it stationary, carrying out this process safely by properly distributing the braking force between the wheels. It can fail due to misalignment or misadjustment of the pin, poor fixing or poor contact of the brake chamber or damage to the safety valve.

Success story: implementing continuous remote monitoring in off-road vehicles

Dynamox and Vale developed a project to monitor faults in off-road vehicles at the Carajás Mine, located in the state of Pará. Before the solution was implemented, in order to inspect the motorized wheels, the vehicle had to be kept stationary so that it could enter the basement and remove the wheel pinion. After removing the pinion, it was necessary to dismantle the casing of the motorized wheels, and only then was it possible to attach the accelerometer and start collecting data.

As well as being unsafe, the process of collecting data from the drive wheels meant that the vehicle had to be stopped for around two hours, reducing productivity. Vale’s maintenance team therefore identified opportunities for improvement and sought to enhance this collection process. In partnership with Dynamox, the solution found was to use wireless vibration and temperature sensors, making it possible to collect data remotely.

When it comes to the motorized wheel, the device is fixed inside the wheel and stores the vibration and temperature data in its internal memory. In addition, with a periodicity defined for each truck, the inspector collects the data that is saved in the device’s internal memory, as well as obtaining a vibration spectrum in a stable and known condition.

This known condition occurs when the truck is driven at a continuous speed for a short distance. At this point, using a tablet, the inspector connects to the sensors installed in the wheels, at a safe distance.

Trigger: device developed by Dynamox to optimize data collection

In the project between Vale and Dynamox mentioned above, Trigger was developed, a Gateway feature that enables operation-based monitoring. The function of this solution was to meet a particular need of the project: to collect data at specific times, being able to interpret various signals and trigger spectral collection actions from the associated sensors.

To identify events, the Trigger has digital, analogue and CAN inputs, allowing the definition of various single or combined logic rules so that the gateway understands the best time for data collection and triggers the command to take spectra from the sensors when it recognizes this moment.

Trigger operation is based on triggering actions under predetermined and configurable conditions, by means of signals received at one of the available interfaces. These signals can be: tilting action, equipment activation, rotation or a set of two or more signals.

The use of the Trigger device is indicated in any application that does not have a constant operating regime, such as off-road vehicles, allowing correlatable and comparable data to be obtained for the identification of faults and behaviors.

In this way, the Dynamox solution helps maintenance teams overcome the challenges of monitoring off-road vehicles. The wireless sensors provide reliable vibration and temperature data collection, and the Gateway allows this information to be collected without exposing professionals to the risks of working near these assets. Finally, the Trigger, initially developed for Vale, but already widely used for operation-based monitoring, guarantees the standardization of collections according to need.

Do you want to increase the reliability and availability of off-road vehicles? Discover the Dynamox solution! Contact us to find out more.