Moving Magnet Actuator MI FFA series

Transcription

1 Moving Magnet Actuator MI FFA series The moving magnet MI-FFA series actuators are a line of actuators designed to be a true alternative for pneumatic cylinders. The actuators incorporate an ISO 6432 interface identical to their pneumatic counterparts. With this interface customers can choose from a variety of widely available mechanic adaptors such as mounting brackets, rod eyes, clevis brackets etc. The working principle of the moving magnet actuator is that the moving part contains a magnet. The coils are attached to the static part of the actuator which enables a good heat conduction to the environment. A good thermal path is beneficial for high force densities. The absence of moving wires leads to a very high reliability and lifetime and does not limit the achievable accelerations and speeds. Through a pair of integrated slide bearings the mover is guided inside the stator. The MI-FFA series actuators are single phase actuators which means that there is no need for complex current commutation. This makes the actuators suitable to be operated in open loop mode. The required peripheral control electronics are therefore kept to a minimum. Simply attach a power supply to both actuator terminals and it will move, reverse the polarity and it will move in the opposite direction. For more controllability or accuracy these actuators can also be used in a position control loop using a feedback sensor. Application areas: Production automation Packaging equipment Test stands Pick and place applications Key features: Fast actuating direct drive Single phase moving magnet Simple control Robust and reliable Model options: Heat sinks (extension -HS) Temperature sensor (extension TS) Position switches (extension PS, default 2 switches will be supplied)

2 Technical Data Model stroke [mm] Peak [N] Continuous [N] Constant [N/A] moving mass [kg] Resistance [Ohm] Steepness [N²/W] Inductance [mh] Thermal resistance [ C/W] Thermal Time constant [min] Peak [V] Peak [A] [1][2] [2] Notes: [General] The maximum allowed operating voltage is 48VDC. All specifications are ±10%. [1] Applicable at a force duty cycle of 10%. With lower duty cycles higher forces are possible. [2] Defined at Tambient=40 C, Tcoil=120 C and in the center position [3] Where applicable defined at 20 C and in the center position [3] [3] FFA FFA FFA FFA FFA FFA FFA HS FFA HS FFA HS FFA HS FFA HS FFA HS [3] [2] [2]

3 Dimensions Model A [mm] B [mm] Stroke [mm] Remarks FFA FFA FFA FFA FFA FFA

4 constant variation over stroke Note: All single phase actuators (including moving coil actuators and solenoids) have a force constant that varies over their stroke. As can be seen from the graphs above the MI-FFA series actuators have a very flat force constant over the largest part of the stroke

5 Model Fpeak [N] moving mass [kg] Average speed over stroke [m/s] load [kg] FFA FFA FFA FFA FFA FFA FFA HS FFA HS FFA HS FFA HS FFA HS FFA HS Speed comparison MI-FFA series versus pneumatic cylinder Note: 1) What applies for pneumatic cylinders also applies here. The speed is largely dependent on the load. Part of this load is friction. For calculation a friction of 1 N is assumed. For heavier loads on the bearings of the actuator a larger friction is to be expected. 2) Calculations are performed for the peak forces which are applicable at a force duty cycle of 10%. For lower duty cycles higher forces and faster movements are possible

6 Control Examples This is the easiest and most cost efficient way to control the FFA actuator, using only 2 relays and a power supply. For tighter control of the actuating force you can use inexpensive power electronics and a PWM control signal. Note that also control of the simplest form (depicted above) can be realized with this hardware setup. For state-of-the-art controllability of the FFA actuator it can be incorporated in a closed loop servo system as described here