Air Gap - Tecnotion TM3 Series Manual

It can be cost effective to determine the required magnet track length by
means of the effective area instead of the coil unit length. This is especially
interesting when an extra magnet plate is required to attain the minimum
hub length when, according to the coil length, it falls short by approxima-
tely 25mm. This method will save the need for one magnet plate.
The effective area of a coil unit is the area where the actual windings are
situated in the coil, see picture 3.1. In this area the force is created that
propels a linear motor. The remaining space accommodates for example
the wiring, the PCB or filler material. This non effective area of the coil can
overrun the end of the magnet track without any loss of force.
A
Picture 3.1: Location of effective area
Example
Magnet length calculation with coil
unit length
Hr = Required stroke 440mm
Lc = TL6 Coil unit length 146mm
Mpl = Magnet plate length 288mm
Required number of magnet plates
=(Hr + Lc)/Mpl > two 288mm magnetplates
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C B
Magnet length calculation by means
of effective area
Hr = Required stroke 440mm
Leff = Lc – (a + b) = TL6 Coil unit effective
area 114mm
Mpl = Magnet plate length 288mm
Required number of magnet plates
=(Hr + Leff)/Mpl < two 288mm magnetplates
Table 3.2 states the location where the effective area of a coil starts and
ends.
Parameter Unit Dimension 3
Cableside mm A 19
End mm B 8
Effective area mm C 66
Parameter Unit Dimension 6 9
Cableside mm A 26 25
End mm B 6 5
Effective area mm C 114 164
TB
Parameter Unit Dimension 12 15
Cableside mm A 26 26,2
End mm B 2 6,2
Effective area mm C 216 257,6
Table 3.2: Dimensions of the effective area per motor type

3.1.2 Air gap

The air gap between the magnet plates and the coil unit can be increased
to overcome tolerance issues in clearance or deviations in parallelism or
flatness. Especially for large axis configurations this can be helpful.
Decreasing the air gap is not recommended because of the tight toleran-
ces this creates for the mechanics in the design and the increase in costs
this creates.
CH 3
TM
6 12 18
23 23 26,7
6 2 3,7
114 216 305,6
TL
12 15 18 24
26 26,2 26,7 26
2 6,2 3,7 2
216 257,6 305,6 440
TBW
30 18 30 45
26,2 34,7 39,2 39,2
6,2 3,7 11,2 11,2
529,6 305,6 529,6 801,6
12