The basic requirements for pump drives include maintenance-free and reliable operation, smooth and quiet running and optimum noise characteristics so as not to disturb people in the vicinity. Depending on the pump type and task, there are even more requirements. For example, if the primary aim is to ensure a smooth flow of the medium, such as when supplying cooling and process water or cleaning solutions, the drive speed must be absolutely stable. Pumps for filling liquids also require maximum positioning accuracy. As pump drives are often operated around the clock, energy-efficient solutions are required almost in every case.
The motors must therefore offer a high degree of efficiency over a wide speed and torque range. Some pump types, such as peristaltic pumps, also require high torques when starting up, especially when the tubing is cold. Safety extra-low voltage is also often an issue because compact dimensions reduce the space available for insulated sections. Many applications also have EMC requirements

In mobile pump applications, the motor must also be suitable for battery operation, meaning it must be energy-efficient, lightweight and take up little installation space. If the environment is hot, the drives must also be able to withstand high temperatures. This is often the case when coolant is pumped, for example in quick- charge stations or for server cooling.
The right drive from the modular system
Such a wide range of requirements doesn’t make drive selection easy. To help pump manufacturers quickly find what they are looking for, ebm-papst’s modular drive system includes BLDC internal rotor motors with different outputs and sizes, which can be combined with various gearbox designs – including for particularly quiet operation – with many reduction stages and brakes (Fig. 1). There are suitable encoders with high resolution for demanding positioning tasks as well as industry-standard connection technology with plugs or pre-assembled cables.
The modular system for drives with a diameter of 42 mm (ECI-42) or 63 mm (ECI-63) allows users to customize the right solution by combining different modules (Fig. 2). A great deal of application expertise is involved in the development of compact, electronically commutated, brushless internal rotor motors. This makes them perfect for use as pump drives, and their users benefit from complete drive solutions from a single source.

Due to their high power density, the drives are very compact, which is beneficial to the device design and often enables more compact dimensions. If required, individual adaptations over and above the standard design can also be made, for instance with regard to mechanical interfaces such as spindles and gearwheels.
Different power classes for a wide range of applications
The ECI-42 brushless, electronically commutated internal rotor motors are available with stator lengths of 20 or 40 mm. They achieve outputs from 45 to 92 watts at 110 or 220 mNm nominal torque and 4,000 rpm nominal speed.

With stator lengths of 20, 40 or 60 mm, the larger ECI-63 motors cover the power range from 150 to 370 W at up to 880 mNm nominal torque and 4,000 rpm nominal speed. Their efficiency is over 90%. Both motor series have already proven their efficiency in many different pump types, in gear and rotary vane pumps as well as piston, screw spindle and peristaltic pumps (Fig. 3). Even electromobility wouldn’t be possible today without powerful pumps.
Quick-charge stations, their power electronics, charging cables and any existing buffer storage need cooling concepts that can be easily integrated and work reliably over a long period of time, even under sometimes very harsh environmental conditions (Fig. 4).
Cooling circuit application
With charging capacities of up to several hundred kilowatts, the cables are liquid-cooled, with pumps and drives for the pumps an indispensable part of the process. The internal rotor motors from the modular drive system have proven themselves as the driving force in these applications over many years. One example of this is the ECI-63 internal rotor motor, which, thanks to its high power density, is typically used as an efficient pump drive for cooling charging cables in the level 3 range with charging currents of up to 500 A (Figs. 5 and 6).

With variants in the 150 to 370 W power range, the compact drive covers a wide range of applications. Thanks to high-quality components, even ambient temperatures of up to 80 °C are no problem for the integrated electronics. This is why the temperature-resistant and reliable ECI-63 drives, like the smaller ECI-42 variants, are also used as pump drives in the cooling circuits of modern high-performance servers. However, speed/torque controlled external rotor motors from the VDC series are also ideally suited to cooling solutions, and additionally enable users to make inferences about pressure and coolant flow, for example, due to their torque management.
This means additional sensors are not required in the application, which has a positive effect on the system control of the charging station. The electronically commutated VDC drives likewise operate at high levels of efficiency and meet strict EMC regulations. The modular drive system also offers the right accessories for these motors, from the gearbox to the connection technology, so that the right drive can be found for almost any pump to meet the specific requirements profile of the task in question. In addition, ebm-papst also offers solutions for customer-specific requirements.
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