EMRAX motor is a completely new type of pancake axial flux synchronous electric motor. It can also work as a generator with the same technical data. The drive was tested on electric glider airplane Apis EA2 and it was also laboratory tested in Siemens (May 2012) and Piktronik company. Also our customers who have bought our motors give us some results which are comparable with our tests.
We achieved our objective and built a high-powered, high torque, extremely light, direct drive, low RPM, low noise electric motor, which efficiency is up to 96%. Because of the high torque EMRAX engine can achieve high power also at relatively low rotation speeds. High torque allows the motor to drive systems directly and also improves the system efficient.
EMRAX allows a gearless drive without the usually essential step-up gear unit which causes power losses, additional weight, complexity and maintenances. The motor has much higher power-to-weight ratio compared to other brushless AC motors. Mechanical and no load electrical looses are very small, so our motor can run up to 4000 RPM. Peak rotation is 5000 RPM (tested in Siemens) - in this case the motor can achieve at least 100 kW. EMRAX can also deliver few times higher torque at higher RPM with some reduction drive.
Because of the small internal winding resistance, very low power dissipation of eddy currents in the motor and in all very good performances we are achieved in a wide range operating and at an excellent efficiency. Motor has no cogging, no vibration. High torque at low RPM can give high power without noise and with the best efficient.
EMRAX motors are suitable for electric vehicles - EV, power plants, wind and hydro power stations.
We offer different EMRAX motor types (all types are very similar to each other; they have only a few major differences):
- EMRAX Standard AC or LC
- EMRAX Low Voltage AC or LC
- EMRAX High Speed AC or LC
EMRAX new phase connectors:
Table 1: Technical data of EMRAX motors
Standard AC, air flow
speed 25 m/sec, 20°C
Standard LC, water
flow 0,2 l/sec, 20°C
|EMRAX Low Voltage AC or LC||EMRAX High Speed AC or LC|
|Motor/generator type||Brushless synchronous three phase AC motor/generator|
|Weight||11,8 kg||12 kg||12 kg||12 kg|
diameter / width
|Φ 228 / 86 mm||Φ 228 / 86 mm||Φ 228 / 86 mm||Φ 228 / 86 mm|
|Voltage range||50 - 400 Vdc||50 - 400 Vdc (*600 Vdc)||24 - 120 Vdc||50 - 300 Vdc|
|Peak motor power
(for a few seconds)
|100 kW||100 kW||100 kW||100 kW|
|Continuous motor power||30 - 50 kW - depends on the motor rotation (10-20% lower cont. power compared to LC motor)||30 - 50 kW - depends on the motor rotation||30 - 50 kW - depends on the motor rotation||30 - 50 kW - depends on the motor rotation|
|Maximal rotation speed||4000 RPM||4000 RPM (*5000 RPM)||4000 RPM||4000 RPM|
|Maximal motor current
(for 2 min if cooled as described)
|240 Arms||240 Arms||1000 Arms||320 Arms|
|Continuous motor current||120 Arms||120 Arms||450 Arms||160 Arms|
Maximal motor torque
|240 Nm||240 Nm||240 Nm||240 Nm|
|Continuous motor torque||128 Nm||128 Nm||128 Nm||128 Nm|
|Maximal temperature of the cooper
windings on the stator
|110 °C||110 °C||110 °C||110 °C|
|Nominal motor efficiency||93 - 96 % - depends on the motor rotation and torque (current)||93 - 96 % - depends on the motor rotation and torque (current)||93 - 96 % - depends on the motor rotation and torque (current)
||93 - 96 % - depends on the motor rotation and torque (current)|
|Internal phase resistant [at 25°C]||18 mΩ||18 mΩ||1,2 mΩ||7,5 mΩ|
|Input phase wire||10,2 mm2||
|| 15,2 mm2
|Induction in d/q axis||Ld= 175µH; Lq= 180µH||Ld= 175µH; Lq= 180µH|
|controller / motor signal||sine wave||sine wave||sine wave||sine wave|
|Specific idle speed
(no load rotation speed)
|10 RPM / 1 Vdc||
10 RPM / 1 Vdc
|40 RPM / 1 Vdc||13 RPM / 1 Vdc|
|Specific load rotation speed||8,5 to 10 RPM / 1 Vdc – depends on the SW settings||8,5 to 10 RPM / 1 Vdc – depends on the SW settings||34 to 40 RPM / 1 Vdc – depends on the SW settings||11 to 13 RPM / 1 Vdc – depends on the SW settings|
|Magnetic field weakening||possible up to 20% to get the same power at higher rotation||possible up to 20% to get the same power at higher rotation||possible up to 20% to get the same power at higher rotation||possible up to 20% to get the same power at higher rotation|
|Magnetic flux||Axial (0,53 Vs)||Axial (0,53 Vs)|
in the motor
|kty 81/210||kty 81/210||kty 81/210||kty 81/210|
|Number of pole pairs||10||10||10||10|
|Ingrees protection||IP21||IP21 (we can also make IP54, but peak power is the same, load time is shorter and continuous power is approximately 20 to 30% lower compared to IP21)||IP21 (we can also make IP54, but peak power is the same, load time is shorter and continuous power is approximately 20 to 30% lower compared to IP21||IP21 (we can also make IP54, but peak power is the same, load time is shorter and continuous power is approximately 20 to 30% lower compared to IP21|
Because of the difference of the magnetic field on the magnets (tolerance 1-2%) the generator voltage between two EMRAX motors can be different for 1-2% at the same rotation. This difference in voltage between the EMRAX motors also depends on the other motor materials.
EMRAX air cooled motors have 10-20% lower continuous power compared to EMRAX liquid cooled.
The specifications for generators are the same as for the motors. If using EMRAX as generator we recommend using liquid cooled type. For all of range the power it need controller.
Technical data of EMRAX Standard LC motor with IP21:
Other important data for EMRAX motors usage:
EMRAX motors have to be used in accordance with Manual for EMRAX Motor published in the bottom of this webpage.
The power transmission to the load is accomplished by a flange joint with an extension shaft at the rotor. The motor power transmission to the load can be made from the front site and/or back site of the motor:
- If the power transmission is from front site of the motor, than the flange joint has to be provided by the customer himself.
- If the power transmission is from back site of the motor customer needs prolonged motor shaft (Enstroj offers universal prolonged motor shaft), also in this case the 6 screws M8 must be screwed down 16 mm (maximal 16,5 mm) into the aluminum/steel flange in the front site of the motor (they carry the torque from rotor rings to the prolonged shaft).
- If the motor power transmission is from front and back motor site, than the motor needs front flange joint (provided by customer) and prolonged motor shaft (made by Enstroj).
- EMRAX TWIN version needs prolonged motor shaft with flange connection to the second motor, which is wired serial. Prolonged motor shaft with flange connection for EMRAX TWIN must be original (must be made by Enstroj). If other shaft is used to connect two motors the warranty does not apply.
The section bearings of the rotor are not qualified for forces higher than bearings FAG or SKF model 6206 or 7206 can transfer. Distance between the bearings is 47 mm:
- If the motor is used for radial load only the front bearing and the back bearing are the same type – 6206.
- If the motor is used for axial load with pull OR push mode (one direction) one 7206 and one 6206 bearing is needed – e.g. for pull application front bearing is 6206, back bearing is 7206.
- If the motor is used for axial load with pull AND push mode (two directions), than two 7206 bearings are needed (“O – bearing arrangement”). In case of doubts, the case of operation shall be discussed with the manufacturer. If the radial or axial load is higher than bearings can bear, than the system must have additional shaft with suitable stronger bearings (belt transmission, chain transmission, gear transmission, direct drive very high load propellers).
EMRAX motor ingrees protection:
EMRAX motor ingress protection is IP21 – for air and liquid cooled. We can also make liquid cooled motor with IP54, but in this case characteristics of the motor are different (peak power is the same, but load time is shorter and continuous power is approximately 20 to 30% lower - we only predict this, because EMRAX liquid cooled with IP54 has not been tested jet).
Rotation direction; motor speed and position sensors:
The drive can be driven in counterclockwise well as in clockwise rotation. The pole reversal can be achieved by a change of two of the three motor phase cables or by modifying the software settings by the manufacturer of the controller. Three phase power connectors UVW are shown below on the Picture 1 and others. U (black), V (red), W (blue). This is valid for a sensor less commutation (for boats). If the motor uses an encoder or resolver drive control application (for EV and propeller stopping) than auto tuning and presetting into the controller SW for the opposite rotation must be done. If using EMRAX TWIN application with two controllers, than tandem resolvers are needed (take a look at Picture 3 below).
It is important to care for a sufficient cooling of the motor at any time. A high load of the motor while insufficient cooling is only approvable for a short time of usage. In every case, the electronic measuring provided by the manufacturer, should be used to protect the motor from overload.
EMRAX motors have to be used under this standard conditions (using EMRAX at non standard conditions causes a forfeit of warranty claims):
- EMRAX air cooled (IP21): Fresh air has to be served to the drive symmetrically and sufficiently (air speed must be 25 m/s at maximal 20°C air temperature and at maximal 200 kPa pressure). This has to be ensured by intake ports or other air conduction measures.
- EMRAX liquid cooled with IP21: Liquid cooling flow must be at least 0,2 l/s at 20°C inlet water/glycol temperature and ambient air temperature has to be 20 °C.
- EMRAX liquid cooled with IP54: Liquid cooling flow must be 0,2 l/s at 20°C inlet water/glycol temperature, but characteristic of this type of motor are not the same as the characteristics for IP21 motor type (peak power is the same, but load time is shorter and continuous power is approximately 20 to 30% lower).
Cooling flow must be filtered cross the filter which holes diameter or diagonal must not exceed 2 mm.
The EMRAX motor must not exceed the temperature below -20°C and above 110°C on cooper windings; this values are also valid for the bearings. If the temperature on the cooper windings exceeds these values, it causes a forfeit of warranty claims. Indicator for exceeded temperatures is placed in the motor. In case of disconnection of the temperature sensor, which has to be on the cooper windings, the controller has to stop the motor.
The motor temperature sensor detector in the controller must be always enabled, during the motor operation.
Controllers for EMRAX motor:
Every EMRAX is tested at standard parameters (take a look at Table 1: Technical data of EMRAX motors) in our company operating as a generator and as a motor with Unitek BAMOCAR D3 (IP65) or BAMO D3 modified by Enstroj (IP21). There are no or no qualified experiences of other frequency converters (Sevcon, RMS, Semikron, Elmo and others).
- We recommend using controllers BAMO D3 modified by Enstroj or BAMOCAR D3 controller and that the parameters are set at Enstroj company. BAMO D3 modified by Enstroj and BAMOCAR D3 can be ordered directly from Enstroj.
- There are no or no qualified experiences of other frequency converters (Sevcon, RMS, Semikron, Elmo and others).
- Low voltage controller for EMRAX Low Voltage motor must have high output current (1000 A peak / 400 A continuous) to achieve the same power as EMRAX standard with Unitek BAMO D3 controller modified by Enstroj. Suitable low voltage controller for EMRAX low voltage is Sevcon Gen4Size6, but it has only 650 A peak current and 260 A continuous current, so according to this the motor peak and continuous power will be lower (each for approximately 25%).
- We recommend that each EMRAX motor is driven with one controller, even EMRAX TWIN (tandem resolvers have to be mounted as shown on the Picture 3 below). Anyway two motors can be driven by one controller - in this case the mechanical angular degree must be to totally configured in the right position and also both motors must operate under the same temperature conditions (cooling!).
For more about controller for EMRAX motors click here.
Enstroj company does not take any responsibility for difficulties, which are the result of inappropriate configuration, electric system structure and settings which are not in accordance with the latest version of Manual for EMRAX motors. Every motor is tested before shipping at standard conditions (described in the Manual for EMRAX motor). If EMRAX motors are not used in accordance with Manual for EMRAX motor it causes a forfeit of warranty claims. Components of company Enstroj have been developed for usage on electric airplanes, cars, boats, power plants. Company Enstroj assumes no liability in case when a customer uses components for the purposes for which they have not been developed or tested, and especially not for the purpose of presenting a direct threat to human life or health.
EMRAX air cooled (IP21) and EMRAX liquid cooled with IP54
EMRAX with pulley and additional bearing
EMRAX TWIN carrier options
How to order?
Now we are selling the EMRAX motors as prototype motors. For the price list please ask us by email:
The price depends on the type and the amount of ordered motors.
The motors (air and liquid cooled) are patented.
Patent number is: P-201000114
The motors (air and liquid cooled) are patented.
Patent number is: P-201200215
We give 1 year warranty if our motor is used in accordance with Manual for EMRAX motor.
|User Manual for EMRAX motor - April 2013
file type: PDF, file size: 1,77 MB
|User Manual for EMRAX motor - October 2012
file type: PDF, file size: 952 KB
|User Manual for EMRAX motor - July 2011
file type: PDF, file size: 952 KB