GB508872A - Improvements relating to interpoles for commutator dynamo electric machines - Google Patents

Abstract

508,872. Dynamo-electric machines. TUSTIN, A., and METROPOLITAN - VICKERS ELECTRICAL CO., Ltd. Jan. 21, 1938, No. 2121. [Class 35] In a commutator dynamo-electric machine having interpoles, a coil is provided at the side of an interpole linking the leakage flux from the interpole to the adjacent parts of the machine and connected in a closed series circuit with a second coil surrounding the interpole and linking with the working flux from the interpole to the armature, the coils being proportioned and arranged so that the current set up in the first coil due to a change in leakage flux consequent upon a change in the excitation of the interpole will be greater than the current set up in the second coil by the change in the working flux of the interpole whereby the current from the first coil will circulate through the second coil in a direction to assist the change in the working flux. In machines intended to rotate in both directions, coils 4, 6, Fig. 3, on opposite sides of an interpole are connected in closed series circuit with a coil 5 surrounding the interpole. The coils may be formed from a single strip or they may be in two pieces joined together as shown in Fig. 5. The sides 9, 10 may be offset as shown with respect to the ends so that they can be applied close to the interpole faces and insulated or taped in position with the exciting winding which is located on the outside.