Winding apparatus and a method of winding

1. A winding apparatus for applying a winding of a band of material to a limb of a transformer core, the winding apparatus comprising:

a guide member having a longitudinal axis,

a fixing element configured to fix a position of the guide member in relation to the limb of the core,

a rotary member having an axis of rotation which is essentially parallel to the longitudinal axis of the guide member, which rotary member comprising a through opening arranged to enclose a cross section of the core limb,

an attaching element configured to attach a supply of the band of material to the rotary member, and

a rotating element configured to rotate the rotary member, and a displacing member configured to displace the rotary member along the longitudinal axis of the guide member.

2. The winding apparatus according to claim 1 , wherein the attaching element is configured to attach a first supply and a second supply of the band of material to the rotary member.

3. The winding apparatus according to claim 1 , wherein the rotary member comprises an annular member comprising a first and a second section which first section is displaceable from the second section for forming a radial opening in the annular member.

4. The winding apparatus according to claim 1 , wherein the supply of the band of material comprises a roll of the band of material, and wherein the attaching member configured to attach the supply of the band of material to the rotary member comprises a pin for fixing the roll of the band of material.

5. The winding apparatus according to claim 1 , wherein the rotary member comprises a collecting element configured to collect a cover strip from the band of material.

6. The winding apparatus according to claim 1 , wherein the rotary member is supported by a carriage which is supported by the guide member and displaceable in the longitudinal direction of the guide member.

7. The winding apparatus according to claim 6 , wherein the rotation of the rotary member is controlled by a first servo motor and the longitudinal movement of the carriage is controlled by a second servo motor.

8. The winding apparatus according to claim 7 , further comprising:

a control configured to control and coordinate the first and second servomotor.

9. A method of applying a winding of a band of material to a limb of a transformer core, the method comprising:

fixing a guide element of a winding apparatus in a fixed position in relation to the core limb,

arranging a rotary member of the winding apparatus around the core limb,

attaching a first supply of the band of material to the rotary member,

fixing an end of the band of material contained in the supply to the core limb, and

rotating the rotary member around the core limb and displacing the rotary member along its axis of rotation, while keeping the core limb stationary.

10. The method according to claim 9 , further comprising:

attaching a second supply of a the band of material to the rotary member and

fixing an end of the band of material contained in the second supply to the core limb.

11. The method according to claim 9 , wherein the rotary member of the winding machine comprises at least one first section and at least one second section which first and second sections together form an annular member and wherein the step of arranging the rotary member around the core limb comprises forming a radial opening in the annular member by displacing the first section from the second section, moving the annular member radially towards the core limb such that the core limb is introduced through said opening and closing the opening by repositioning the first section at the second section such that the core is encircled by the annular member.

12. The method according to claim 9 , further comprising:

collecting a cover strip from the band of material at a collector arranged on the rotary member.

13. The method according to claim 9 , wherein the band of material comprises a non-cured epoxy material for forming an asecond on a transformer core limb.