Bosch DOK-MOTOR-MCL Series, Project Planning Manual

Page: 151 / 196

Final velocity = 0
If the regeneration energy that is determined according to Fig.
11-27 is negative, energy is not fed back. This means that energy
must be supplied to the motor during the deceleration process.
11.6 Efficiency
The efficiency of electrical machines is the ration between the motor output
and the power fed to the motor. With linear motors, it is determined by the
application-related traverse rates and forces, and the corresponding motor
losses.
fig. 11-28 "Determining the efficiency of linear motors" on page 149 can be
used for determining and/or estimating the motor efficiency.
η Efficiency
P
mech
Mechanical output in W
P
V
Power loss in W
F Feed force in N
v Velocity in m/s
Fig. 11-28: Determining the efficiency of linear motors
11.7 Thermal connection of MCL motors on the machine.
An effective power loss dissipation is precondition to reach the specified mo‐
tor data. The height of the power loss in the motor is significantely defined by
the utilization capacity of the motor. The motor performance depends from as
good as or as fast as the power loss can be dissipated.
If the existing power loss of the motor cannot be sufficiently dissipated via the
natural convection, the heat introduction via the screw on surfaces into the
machine construction increases. A very good heat dissipation is reached, if
the screw on surfaces of the primary part and the screw on surfaces of the
secondary part are both connected with a heat-dissipating machine construc‐
tion.
Please observe that an increased heat introduction into the machine con‐
struction reduced the reachable accuracy. The operating temperature of the
motor winding has a vital importance when dimensioning the system with
highest exactness.
With increasing winding temperature, the dissipated heat amount increases
on the machine, too. If the temperature niveau of the machin must be con‐
stantly kept, the motor should be a little overdimensioned or a cooling pre‐
pared on the machine side.
DOK-MOTOR*-MCL********-PR05-EN-P Bosch Rexroth AG 149/193
Rexroth IndraDyn L Ironless Linear Motors MCL
Motor dimensioning