Challenges of thermal management
Bosch's Expertise in optimizing Thermal Management in Off-Highway Vehicles
The central task of thermal management is to control heat flows to maintain components within their optimal temperature range and ensure comfortable air conditioning for cabin occupants. The electrification of construction machinery presents designers with unique challenges.
Imagine being part of a development team tasked with designing a mini excavator. The ever-growing requirements in thermal management and the associated challenges are becoming increasingly diverse. Ensuring the performance, efficiency, and availability of the vehicle relies primarily on selecting the right components.
Increased complexity
For construction machines with a combustion engine, for example, the primary focus is on reducing fuel consumption and emissions. This necessitates effective cooling of engine components and tailored systems, such as SCR exhaust-gas treatment. After-run cooling of these components is crucial for extending service life and preventing damage to cables or plugs caused by excessive heat.
Thermal management becomes even more challenging in fully electric construction machines as heat must be transferred both during operation and during charging. Electric engines and power electronics require constant cooling, while batteries must be carefully temperature regulated depending on operating conditions. Furthermore, without waste heat from a combustion engine to warm the cabin, energy-efficient solutions like heat pumps are essential.
Break-downs and increased downtimes in electrified mini excavators have revealed weaknesses in thermal management systems during the first wave of electrification. Ensuring high availability is critical, particularly for rental services.
Cross-industry potentials
Bosch, an experienced manufacturer of pumps and valves in the automotive industry for over 30 years, has recognized these complexities in construction machinery. The high reliability and quality of Bosch components have proven themselves for decades. This can also help reduce downtime and increase the service life of vehicles in construction machinery.
For instance, coolant switching valves must be evaluated not only on flow rate and resistance but also on the sealing seat's durability over numerous switching cycles — according to the need "leakproof over service life".
For pumps, operating hours are crucial for determining the service life of the entire system. Bosch recently introduced a powerful PDE coolant pump which weighs under 700 grams and delivers an impressive 1.7 bar of pressure at 1200 liters per hour. With its robust design, the BLDC pump has a service life up to 41.000 hours, handling the increased operational demands of electric excavators during charging cycles.
In air conditioning, Bosch's new global brushless blower GBB is quieter and more durable than the previous models. Its integrated circuit board eliminates the need for an additional DC fan controller, reducing costs. Paired with the GBB, the VMC air flap actuator has repeatedly demonstrated reliability and ease of integration. Its immediate torque and precise positioning make it ideal for controlling proportional valves.
These products are just a few examples of Bosch's ongoing commitment to meeting evolving thermal management market demands. With a comprehensive product portfolio and decades of experience, Bosch remains a trusted partner for designers and manufacturers seeking innovative and dependable solutions for their construction machinery.
