Reaction Wheel Type RW- 01

VECTRONIC Aerospace has developed the RW-01 reaction wheel series especially for small satellite applications. Reaction wheels are actuators used to influence the rotational motion of a spacecraft. According to the principle of angular momentum conservation, a torque is exerted onto the spacecraft if the wheel speed is changed. The ratio between acceleration of the wheel and the spacecraft is equal to the ratio of their moments of inertia.

The reaction wheel RW1 comprises the following components:

  • brushless DC Motor,
  • rotor,
  • wheel drive electronics,
  • housing.

 

The wheel speed is controlled with a model supported PI-loop running inside the 32 Bit micro processor which is using a low noise high efficiency four quadrant PWM method in the power stage. The wheel drive electronic includes thermal and over voltage protection circuits. The signal interface is a standard asynchronous SCI on RS422/RS485 level. It can be used in a single full-duplex configuration as well as in a half-duplex bus architecture. The baud rate is adjustable up to 1Mbaud.

The reaction wheel design is kept modular. By changing the rotor geometry, input voltage range or communication protocol, the RW1 characteristics are easy to adapt to customer needs.

The expected In-Orbit lifetime for this type of reaction wheels is more than 40.000 hours.

 

Mechanical

Dimensions

115 mm x 115 mm x 86 mm

Mass

1.8 kg

Moment of Inertia (rotor)

2.12 *10-3 kgm2

Mounting pattern

4x M5  105mm x 105mm

 

 

 

 

Environmental

Operating temp. range

-20°C to +70°C

Storage temp. range

-40°C to +80°C

Vibration

15g rms random 3 axis

Radiation tolerance

>20 krad

Electrical

Power consumption:

 

steady state at nom. speed

< 4.0 W

max. torque at nom. speed

< 25 W

Signal Interface

RS422 / RS485

Signal characteristics

Serial asynchr.

Connector Type

SUB D9 male

Performance

Nominal speed

5000 rpm

Angular mom. at nom. speed

1 Nms

Available torque at nom. speed

20 mNm

Speed ctrl. loop accuracy (2sig)

0.25 rpm

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