Method and device for testing the tightness of an electric machine stator core

1. Method for testing the tightness of an electric machine stator core, wherein the electric machine comprises a stator core formed of iron sheets and a rotor defining an air gap therebetween, the method comprising:

introducing a test instrument connected to a support into the air gap, the test instrument including a plate, the support including a guide circumferentially connected to an outer face of the rotor core of the electric machine, and fixed in a longitudinal axial direction of the rotor core, and a cart being movable along the guide to reach circumferential positions of the stator core, the cart including a longitudinally extendable arm projecting along the longitudinal axis of the rotor core perpendicular to the guide, the test instrument being arranged on a terminal end of the arm distal to the cart;

locally placing the test instrument in a zone of the stator core; and

locally testing defined zones of the stator core by rotating the plate arranged on the arm about an axis defined within the plate between an insertion position and a testing position, from which the plate is introduced between the stator core iron sheets.

2. The method as claimed in claim 1 , wherein tests are repeated a number of times at different axial and/or angular positions.

3. The method as claimed in claim 1 , wherein the plate is elliptical.

4. Device, for testing the tightness of a stator core, formed of iron sheets, of an electric machine, comprising:

a support, insertable in an air gap between an electric generator stator core and a rotor, the support including a guide circumferentially connected to an outer face of the rotor core of the electric machine, and fixed in a longitudinal axial direction of the rotor core and a cart movable along the guide to reach circumferential positions of the stator core;

a test instrument carried by the cart, the test instrument being locally positionable to locally test defined zones of the generator stator core wherein the cart is connected to a longitudinally extendable arm that carries the test instrument, the arm projecting along the longitudinal axis of the rotor core perpendicular to the guide and the test instrument being arranged on a terminal end of the arm distal to the cart; and

a plate arranged on the arm and configured to be rotatable about an axis defined within the plate, between an insertion position and a testing position, the plate configured to be introduced between the stator core iron sheets.

5. The device as claimed in claim 4 , wherein said support is arranged to place the test instrument over at least half of an axial length of the gap.

6. The device as claimed in claim 4 , wherein the plate is elliptical.

7. Method for testing the tightness of an electric machine stator core, wherein the electric machine comprises a stator core formed of iron sheets and a rotor defining an air gap therebetween, the method comprising:

introducing a test instrument connected to a support into the air gap, the test instrument including a plate, the support including a guide circumferentially connected to an outer face of the rotor core of the electric machine, and fixed in a longitudinal axial direction of the rotor core, and a cart being movable along the guide, the cart including an arm projecting along the longitudinal axis of the rotor core perpendicular to the frame, the test instrument being arranged on a terminal end of the arm distal to the cart;

locally placing the test instrument in a zone of the stator core; and

locally testing defined zones of the stator core by rotating the plate arranged on the arm about an axis defined within the plate between an insertion position and a testing position, from which the plate is introduced between the stator core iron sheets.

8. The method as claimed in claim 7 , wherein the plate is elliptical.