Rexroth Kit Motors; Rexroth Kit Motors, Synchronous - Bosch Rexroth IndraDrive MPH-02 Functional Description

MPH-02, MPB-02, MPD-02

Rexroth Kit Motors

Rexroth Kit Motors, Synchronous

Determining the Commutation
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
Motor, Mechanical Axis System, Measuring Systems
General Information
Kit motors consist of individual components that are mounted to a moving
and as static part of the machine's mechanical system and functionally
put together to form a motor.
A kit motor consists of the following components:
• electrically active part with thermo sensor
• electrically passive part
• measuring system
• bearing
The electrical parts of the kit motor are supplied by Rexroth, the
measuring system and the bearing are provided on the machine side.
Rexroth kit motors are manufactured according to the "asynchronous
motor" or "synchronous motor" functional principles. With regard to
control the functional principles have different requirements:
• In the case of synchronous motors, the current in the windings of the
stator must have a fixed allocation to the permanent magnetic field of
the rotor so that the maximum torque or the maximum force is
generated.
• In the case of asynchronous motors there is no fixed allocation
between stator and rotor required in order to generate the maximum
torque or the maximum force.
Brief Description
The following Rexroth kit motors are manufactured according to the
"synchronous motor" functional principle:
• LSF linear motors
• MBS and MBT rotary motors
As the motor is assembled in the machine, stator, rotor and measuring
system can only be put together on site. The electric-magnetic-
mechanical allocation of the synchronous motor is therefore only to be
made on site. This is done by determining and setting the commutation
offset.
Note: The measuring system should be realized with high resolution
and as a motor encoder that can be evaluated in absolute
form (see also "Absolute Measuring Systems"). If it is
necessary to use an incremental measuring system the use of
encoders with square-wave signals should be avoided!
The commutation offset can be determined with different methods. The
Offset method is chosen in accordance with the axis geometry, the practicability
and the success of the respective method depending on the mechanical
axis system:
• measuring method for relative motor encoder and Hall sensor box
(distance measurement, currentless Å only possible with Rexroth
linear kit motors, see documentation "Hall Sensor Box SHL01.1")
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