High-Efficiency Pump for Battery-Powered Agricultural Machines

The electrification of mobile machinery opens up completely new possibilities that – because of their operating principle – today's hydraulic systems simply cannot offer. Overall, electrification offers a mix of different hydraulic drive concepts that can be applied in a flexible combination to meet the requirements of the application and the project budget. For example, the most powerful actuators can be equipped with the new AX pump technology from Bucher Hydraulics while, for drives with lower outputs and shorter 'On' times, conventional load-sensing valve technology may be more economical. But even with these drives, there is plenty of potential for efficiency improvements.

Systematic reduction of losses to a minimum! 

Conventional hydraulic pumps have a high power loss and a correspondingly low efficiency. This is where Bucher Hydraulics came in with the development of a new type of pump that consistently reduces losses to a minimum. It is available with displacements from 18 to 76 cm³/rev, and units with up to 122 cm³/rev will be available in future. The pump is suitable for continuous pressures up to 450 bar, the usual maximum pressure for mobile machinery.

Featuring high efficiencies over a wide operating range and a huge reduction in pressure pulsations, it is the ideal partner for efficient electric drives. Looking at some numbers: While a conventional pump may exhibit a power loss of 5.2 kW, it is only 1.6 kW with the new Bucher Hydraulics AX pump. This saves a lot of kilowatt hours, a fact that is particularly noticeable with battery operation. The battery can either be made smaller and cheaper, or its running time can be extended, as modeling calculations (and initial experience) have shown. The extremely low friction not only reduces the power loss, it also decreases wear to almost zero. This makes it possible to achieve a long and reliable service life.

Low-noise drives

The new AX pump also solves the previously mentioned problem of many electrification projects: the high noise level of the hydraulic components. End users expect electrical machines to have a low noise level that today's axial piston pumps cannot match. Gear pumps are quieter, but they are not designed for the pressure range required for construction machines. Additional sound insulation is difficult to implement due to the cramped conditions, and costly. The AX pump eliminates the causes of noise emission. Even at high power levels, it operates at a comfortable noise level that is comparable with that of electrical machines.

Energy-efficient and 100% recyclable

A typical lifting/lowering function for loaders gives a good illustration of the energy-savings potential of the AX when compared with a valve-controlled system and with an electrohydraulic linear drive using a conventional pump. The power loss from the high-efficiency AX pump can be as much as 50% less. The new operating principle also removes the minimum speed limit that would otherwise have to be observed. This makes it possible to achieve precise cylinder movements without any additional measures. This considerably simplifies and extends the application scope for variable-speed pumps. The AX pump from Bucher Hydraulics therefore meets all the requirements for battery-electric drives for mobile machines.

Hydraulic systems in comparison

The AX pump reduces the system power loss by about half when compared with a conventional pump and comparable performance data.

More information about AX pumps and motors

Product information:
Axial Piston Pumps AX

Blog post:
Sustainable AX Pumps and Motors