Eaton X20 IPPC for Fan Drive Solution

iHydrostatics previous post N4:S45 EPC and Its Fan Drive (History information can be reached by replying N4 in Wechat iHydrostatics) illustrated Danfoss S45 pump EPC (Electric Proportional Control) control and how it works in hydraulic fan drive system. Hope it helped you to understand this kind of technical solution which will be the trend in the coming years. Feel free to leave your comments in iHydrostatics QQ Group: 426372753.

Not only Danfoss S45 EPC, Eaton has also launched the hydraulic fan drive solution with X20 IPPC (Inverse Proportional Pressure Control) control type not long ago.In this post, some detailed information will be investigated for this kind of new design and difference comparison with S45 EPC will also be covered as well.

1 What Is IPPC

Overview

Eaton EH IPPC (Inverse Proportional Pressure Control) allows for stepless variation of the max pump output pressure, as per the current signal provided to the control valve solenoid. The integrated pump control makes use of an external current signal to vary the pump output pressure. This control has an inverse proportional characteristic i.e. with increasing current signal; the max output pressure is proportionately reduced.

Structure ViewX20 EH IPPC Control Outline

EH IPPC Characteristics

EH IPPC control consists of an electric proportional valve and a variable PC setting valve as shown in the hydraulic schematic below. When no current is input, the max limited outlet pressure is the original PC setting; while once current is applied to the proportional valve, an additional pressure will be acted on the PC spool, then the max limited outlet pressure will be decreased accordingly.

Based on the design principle, IPPC control has a negative relationship between input signal and max limited outlet pressure. The pump outlet pressure decreases proportional to an increase in input current. The EH IPPC covers pressure range of the ADU pumps. The max pressure can be set from 140 bar (2050 psi) to 280 bar (4060psi). The relationship between current and pump pressure is unique for each individual PC setting. The relationship between different PC settings vs. Current Characteristic curve is shown below.

2 How IPPC in Fan Drive

Eaton IPPC solution has the same purpose as Danfoss S45 EPC solution, check N4 post for detailed description. Eaton fan drive system solution consists of X20 IPPC pump, Gear Motor, Cyclone tank and HFX12m controller as shown in the following picture.

The inverse proportional pressure control (IPPC) allows fan speed to be controlled independent of engine speed and load. When coupled with an X20 product, the IPPC enables accurate and efficient control of fan power, providing vehicle design engineers and system integrators another way to direct engine power. By directing power to where it is needed most during a vehicle’s operating cycle, the system saves fuel and boosts productivity. Inputs from individual temperature sensors or the vehicle’s CAN bus are used to manage total vehicle cooling and enable engine after-treatment requirements to be well-matched.

The following video may help you understand Eaton fan drive solution more vivdly, but iHydrostatics strongly recommends you to watch this under WiFi condition.

3 IPPC vs. EPC

If you missed Danfoss S45 EPC, reply N4 in Wechat iHydrostatics to get detailed introductive information. By comparing X20 IPPC and S45 EPC, we can come to the following summary.
Based on the hydraulic schematics, Eaton IPPC adopts a proportional valve and a PC valve design, while S45 EPC takes the design of remote pressure valve together with proportional pressure valve and a PC valve.

Because of different design principles, controlled outlet pressure of S45 EPC is not only limited by PC valve setting, but also related to RP setting which can be concluded by the characteristic curve shared in N4 post.