Printed Motor Works pioneered the development of the in-wheel electric motor and have delivered many samples and prototypes to a wide variety of customers in the marine, aerospace & defence, heavy industrial and commercial automotive markets.
Printed Motor Works have a wide range of hub motors available for highly specialised applications. The in-wheel XR series (XR stands for eXternal Rotor) offers a glimpse into the future of powered wheel technology. We are happy to work with customers to develop, manufacture and supply wheel motors for these specialist applications.
In-Wheel XR Series Motors
The in-wheel XR series is a permanent magnet brushless motor with an external rotor. Permanent magnet brushless motors are generally the most efficient and highest torque density motors available today. The XR series gains from two distinct additional advantages: the magnets are positioned on an externally running rotor which gives the motor the fundamental geometric advantage that torque is being delivered on the outer-most point of the motor. Finally, the torque density of the XR series is maximised by a high degree of slot fill. The high slot fill is achieved by winding each of the stator teeth individually before assembling them together into a stator.
The stator teeth of the XR series are modular and interlock in such a way that we can vary the diameter and length of the stator more or less infinitely to fit both the packaging and the power requirements of the application. The in-wheel XR series can be liquid cooled or even oil filled for subsea applications that require underwater pressure compensation.
Applications for the XR Series in-motors include substitution of large high torque hydraulic actuation systems with a compact efficient motor, industrial and marine winch systems, propulsion of bomb disposal robots and other specialised military electric vehicles and trailers, traction for commercial electric vehicles for example in mining, direct drive radar systems, direct drive railway vehicles, compact generators for auxiliary power units, and general hybridisation of vehicle propulsion systems.
Below are some examples from the XR Series in-wheel motor range:
|Performance Specifications||Water cooled||Water cooled|
|Peak Torque||T P||Nm||14||-||-||160||400||577||-|
|Rated Continuous Torque @ 50°C||T25||Nm||8||25||31||60||250||300||753|
|Rated Output Power||P||kW||0.402||1.2||1.5||4.7||3.93||5.87||47|
|Maximum Recommended Speed||Nmax||RPM||-||-||-||1040||2000||2000||-|
|Peak Output Power||P||kW||0.960||23.1||37.6||55.0|
|Nominal Operating Voltage||E||Volts||48||36||36||66||100||100||300|
|Typical Operating Voltage Range||E||Volts||12-196||24-144||24-144||66-114||50-650||50-650||50-650|
|Rated Continuous Current||I||Amps (RMS)||10.25||60||60||72||213||322||250|
|Peak Current||I P||Amps (RMS)||20||-||-||350||376||550||-|
|Line-Line Resistance||R L-L||Ohms||0.49||0.074||0.074||0.0122||0.16||0.16||-|
|Back EMF Constant||K E||V/kRPM||61||47.7||47.7||48.23||110||110||276|
|Torque Constant||K T||Nm/Amp||0.58||0.44||0.44||0.8||1.05||1.05||2.94|
|Armature Inductance (Line-Line)||L||mH||0.54||0.54||0.1424||11||11||-|
|Length (mounting face to face)||mm||49||89||89||112||130||130||-|
|Permitted Radial Load (50% safety factor)||kg||50||180||1500||1500||-|
|Permitted Axial Load (50% safety factor)||kg||45||1200||1200||-|
|Air Speed @ 150 RPM||m/s||2.75||2.75||-||2.75||2.75||-||2.75|
The following data sheets are available for the XR Series brushless DC in-wheel motors: