Page 168 - Mechatronics with Experiments

154 MECHATRONICS
OAL
LTB G

OD HD

BSE
(a)

C F+2
N

A D1 D2 B

C
F+2 L
I (DIN 912)
(b)

(c)
FIGURE 3.12: Flexible couplings used between connecting shafts in motion transmission
mechanisms to compensate for the shaft misalignments and to protect bearings.

5. input and output shaft diameters,
6. input/output shaft connection method (set screw, clamped with keyway),
7. design type (bellow or helical coupling).

3.6 ACTUATOR SIZING

Every motion axis is powered by an actuator. The actuator may be electric, hydraulic or
pneumatic power based. The size of the actuator refers to its power capacity and must be
large enough to be able to move the axis under the given inertial and load force/torque
conditions. If the actuator is undersized, the axis will not be able to deliver the desired
motion, that is cannot deliver desired acceleration or speed levels. If the actuator is oversized,
it will cost more and the motion axis will have slower bandwidth since, as the actuator size
gets larger (larger power levels), the bandwidth gets slower as a general rule. Therefore, it