Contact unit and contact system for an on-load tap changer and on-load tap changer

1. Contact unit for an on-load tap changer, comprising:

a connector body and a first contact holder coupled to each other, wherein the connector body is configured to be connected to a rotatable contact ring and to connect the first contact holder to a contact of the on-load tap changer,

a first contact element coupled to the first contact holder and configured to make electrical contact to a second contact element of a first contact device for the on-load tap changer, and

first drive and guiding means coupled to the first contact holder such that the first contact element is movable driven and linearly guided in a first direction away from the connector body that is oblique to a radial direction of the contact ring, the first drive and guiding means comprising at least one linear ball bearing and an axis arranged inside the bearing configured to provide linearly guided movement of the first contact element of the contact unit;

a second contact holder coupled to the connector body,

a third contact element coupled to the second contact holder and configured to make electrical contact to a fourth contact element of a second contact device for the on-load tap changer, and

second drive and guiding means coupled to the second contact holder such that the third contact element is movable driven and linearly guided in a second direction away from the connector body that is oblique to the radial direction of the contact ring and that is oblique to the first direction, and

the first and second contact holders, the first and third contact elements and the corresponding first and second drive and guiding means being coupled to the connector body such that the first and second directions the corresponding first and third contact elements are movable along enclose a predetermined angle.

2. Contact unit according to claim 1 , wherein the first contact element of the contact unit comprises a rotatable roller to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

3. Contact unit according to claim 1 , wherein the first contact element of the contact unit comprises a slider to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

4. Contact unit according to claim 1 , wherein the first drive and guiding means comprise a spring configured to act a spring force driving the first contact element of the contact unit away from the connector body.

5. Contact unit according to claim 1 , wherein the first drive and guiding means comprise a second linear bearing and a second axis arranged inside the second bearing and wherein the first contact element of the contact unit is arranged between the first and second bearings.

6. Contact system for an on-load tap changer, comprising:

a contact unit according to claim 1 , and

a contact device with a contact terminal and a fifth contact element configured to provide power supply due to interaction of the first and third contact elements of the first and second contact units and second and fourth contact elements of the first and second contact devices.

7. Contact system according to claim 6 , wherein the second contact element of the first contact device comprises a curved shape and extends along a ring section.

8. Contact system according to claim 6 , wherein the first contact element of the first contact unit and the second contact element of the first contact device each comprise a respective contact surface configured to face each other along the direction the first contact element of the first contact unit is movable.

9. The contact system according to claim 6 , wherein the first contact element of the contact unit comprises a rotatable roller to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

10. The contact system according to claim 6 , wherein the first contact element of the contact unit comprises a slider to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

11. The contact system according to claim 6 , wherein the first drive and guiding means comprise a spring configured to act a spring force driving the first contact element of the contact unit away from the connector body.

12. The contact system according to claim 6 , wherein the first drive and guiding means comprise a second linear bearing and a second axis arranged inside the second bearing and wherein the first contact element of the contact unit is arranged between the bearings.

13. On-load tap changer for setting a gear ratio, comprising:

a rotatable contact ring, and

a contact system comprising:

a contact unit comprising:

a connector body and a first contact holder coupled to each other, wherein the connector body is configured to connect the first contact holder to a contact of the on-load tap changer,

a first contact element coupled to the first contact holder and configured to make electrical contact to a second contact element of a first contact device for the on-load tap changer, and

first drive and guiding means coupled to the first contact holder such that the first contact element is movable driven and linearly guided in a first direction away from the connector body that is oblique to a radial direction of the contact ring, the first drive and guiding means comprising at least one linear ball bearing and an axis arranged inside the bearing configured to provide linearly guided movement of the first contact element of the contact unit;

a second contact holder coupled to the connector body,

a third contact element coupled to the second contact holder and configured to make electrical contact to a fourth contact element of a second contact device for the on-load tap changer, and

second drive and guiding means coupled to the second contact holder such that the third contact element is movable driven and linearly guided in a second direction away from the connector body that is oblique to the radial direction of the contact ring and that is oblique to the first direction, and

the first and second contact holders, the first and third contact elements and the corresponding first and second drive and guiding means being coupled to the connector body such that the first and second directions the corresponding first and third contact elements are movable along enclose a predetermined angle;

a contact device with a contact terminal and a fifth contact element configured to provide power supply due to interaction of the first and third contact elements of the first and second contact units and second and fourth contact elements of the first and second contact devices,

wherein the first contact device and the second contact device are configured stationary, and the contact unit is connected to the rotatable contact ring such that each of the first and third contact elements is driven and linearly guided in the direction away from the connector body and towards the respective contact element of the contact device.

14. The on-load tap changer according to claim 13 , wherein the second contact element of the first contact device comprises a curved shape and extends along a ring section.

15. The on-load tap changer according to claim 13 , wherein the first and third contact elements of the contact unit and the second and fourth contact elements of the first and second contact devices comprise respective contact surfaces configured to face each other along the direction the respective contact element of the contact unit is movable.

16. The on-load tap changer according to claim 13 , wherein the first contact element of the contact unit comprises a rotatable roller to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

17. The on-load tap changer according to claim 13 , wherein the first contact element of the contact unit comprises a slider to make electrical contact to the second contact element of the first contact device for the on-load tap changer.

18. The on-load tap changer according to claim 13 , wherein the first drive and guiding means comprise a spring configured to act a spring force driving the first contact element of the contact unit away from the connector body.

19. The on-load tap changer according to claim 13 , wherein the first drive and guiding means comprise a second linear bearing and a second axis arranged inside the second bearing and wherein the first contact element of the contact unit is arranged between the bearings.