Thermal Envelope of Performance (EOP)
Nanomotion Ltd.
Page 23 of 29
3
Thermal Envelope of
Performance (EOP)
3.1 Description
Motor operating temperature is a result of the balance between heat generation and
heat dissipation.
•
The heat generation depends on motor's work regime (driver command level).
•
The heat is dissipated through the following heat transfer mechanisms:
conduction, radiation and convection (the convection mechanism is negligible in
vacuum environment).
The heat dissipation mechanisms should be able to dissipate the heat generated in
order to avoid overheating. The EOP gives the user the tools to assess the
permitted operating conditions (for set ambient temperature and command, deriving
the duty cycle and maximal continuous operation that assures safe operation).
The user can either operate the motor for an extended period of time at a specific
duty cycle or alternatively, can operate the motor for a continuous time period
specified under “Maximal Continuous Operation Time” (see graph and table in
section
3.3). After the continuous operation is completed, the driver must be
disabled to cool down the motor for 400 sec in air and for 700 sec in vacuum
environment.
•
Notes:
The duty cycle is the ratio of the operation time and the total work cycle (operation time +
◘
idle time).
Upon operating a motion system in vacuum, it is expected that the Coefficient of Friction of
◘
the bearing structure will increase. This may require changing the system operation point
on the thermal EOP curves.
