DC motor with angle sensor, rotor with windings and rotary transmitter for DC motor, couch for magnetic resonance system, and method for operating a DC motor with angle sensor

A magnetic resonance (MR) system configured to generate an external magnetic field, the MR system comprising:

• a couch;
• and
• a direct current (DC) motor configured to adjust and/or displace the couch, wherein the DC motor includes:
• a rotor which is rotatable about a rotation axis and has first and second windings;
• at least four continuous rotary transmitters, wherein:
• first and second rotary transmitters of the at least four continuous rotary transmitters are associated with the first winding and are configured to supply the first winding with direct current, the first rotary transmitter forming a positive pole of the first winding and the second rotary transmitter forming a negative pole of the first winding, and
• third and fourth rotary transmitters of the at least four continuous rotary transmitters are associated with the second winding and are configured to supply the second winding with direct current, the third rotary transmitter forming a positive pole of the second winding and the fourth rotary transmitter forming a negative pole of the second winding;
• an angle sensor configured to determine an angular position of the rotor, and
• a controller configured to control the DC feed to at least one of the first and second windings based on the angular position of the rotor,
• wherein the motor is oriented relative to the external magnetic field during operation such that the rotation axis extends transversely to the external magnetic field.

A method for operating a direct current (DC) motor in an external magnetic field, comprising:

• placing the motor in an externally-generated magnetic field of a magnetic resonance scanner, such that a rotation axis of the motor extends transversely to field lines of the externally-generated magnetic field, wherein the motor includes:
• a rotor which is rotatable about the rotation axis and has first and second windings, at least four continuous rotary transmitters, wherein:
• first and second rotary transmitters of the at least four continuous rotary transmitters are associated with the first winding and are configured to supply the first winding with direct current, and an angle sensor configured to determine an angular position of the rotor, the first rotary transmitter forming a positive pole of the first winding and the second rotary transmitter forming a negative pole of the first winding, and
• third and fourth rotary transmitters of the at least four continuous rotary transmitters are associated with the second winding and are configured to supply the second winding with direct current, the third rotary transmitter forming a positive pole of the second winding and the fourth rotary transmitter forming a negative pole of the second winding;
• applying current to at least one of the first and second windings to generate a Lorentz force to cause the rotor to rotate about the rotation axis;
• determining, by the angle sensor, a current angular position of the rotor;
• adapting, by a controller of the motor, an application of current to the first and second windings, based on the determined current angular position, such that the rotor assumes a predetermined angular position.