Actuating device for the rotation of a turbine shaft train

1. An actuating device for rotating a turbine shaft train, comprising:

an electrically operated principal turning gear,

a hydraulically operated auxiliary turning gear adapted to be controlled by a rod of a double-acting hydraulic cylinder;

wherein the auxiliary turning gear includes,

a wheel that is integral with the shaft train, and an actuator connected to the rod of the cylinder, wherein the actuator is configured to engage drive members arranged on a periphery of the wheel and configured to be displaced between a retracted position disengaged from the wheel and a position of engagement with one of the drive members, in which an extension movement of the rod of the cylinder controls the rotation of the wheel,

the actuator being connected to the rod of the cylinder by an articulation supported by a slide that is integral with the rod of the cylinder in such a way as to be pivotable between the retracted position and the engagement position, wherein the slide has a U-shaped form including a bottom part fixed to the rod of the cylinder, and uprights that support a pivot shaft for the articulation; and

a plurality of guiding plates supported by a plate that is integral with the cylinder, the plurality of guiding plates configured for guiding the slide in translational movement at a time of displacement of the rod of the cylinder, the plate including two columns,

wherein the plurality of guiding plates are supported by the columns, such that each column has two guiding plates of the plurality of guiding plates, the two guiding plates connected to respective perpendicular faces of each column and the uprights of the slide have complementary guiding surfaces for complementing the plurality of guiding plates supported by the plate such that the slide is guided by the columns and the plurality of guiding plates on all sides parallel to a direction of the translational movement.

2. The actuating device as claimed in claim 1 , wherein the actuator comprises:

a surface which bears against a first fixed stop that is integral with the plate during a retraction movement of the rod of the cylinder in such a way as to displace the actuator towards said retracted position disengaged from the wheel.

3. The actuating device as claimed in claim 1 , comprising:

a spring configured to cause the actuator to tilt towards said position of engagement with one of the drive members of the wheel during a retraction movement of the rod of the cylinder.

4. The actuating device as claimed in claim 1 , comprising:

a finger mounted movably in relation to the actuator, a movement of the finger permitting one part of the finger to engage in a cavity in the slide in such a way as to immobilize the actuator in an ejection position away from the wheel.

5. The actuating device as claimed in claim 1 , comprising:

an oil circuit under high pressure, which supplies bearings of the shaft train, wherein the hydraulic cylinder of the auxiliary turning gear is supplied with oil under high pressure by said circuit for supplying oil to the bearings.

6. Turbine-generator set for the generation of electricity comprising,

an actuating device for rotating a turbine shaft train, the actuating device including,

an electrically operated principal turning gear, and

a hydraulically operated auxiliary turning gear adapted to be controlled by a rod of a double-acting hydraulic cylinder;

wherein the auxiliary turning gear includes,

a wheel that is integral with the shaft train, and an actuator connected to the rod of the cylinder, wherein the actuator is configured to engage drive members arranged on a periphery of the wheel and configured to be displaced between a retracted position disengaged from the wheel and a position of engagement with one of the drive members, in which an extension movement of the rod of the cylinder controls the rotation of the wheel,

the actuator being connected to the rod of the cylinder by an articulation supported by a slide that is integral with the rod of the cylinder in such a way as to be pivotable between the retracted position and the engagement position, wherein the slide has a U-shaped form including a bottom part fixed to the rod of the cylinder, and uprights that support a pivot shaft for the articulation; and

a plurality of guiding plates supported by a plate that is integral with the cylinder, the plurality of guiding plates configured for guiding the slide in translational movement at a time of displacement of the rod of the cylinder, the plate including two columns,

wherein the plurality of guiding plates are supported by the columns, such that each column has two guiding plates of the plurality of guiding plates, the two guiding plates connected to respective perpendicular faces of each column and the uprights of the slide have complementary guiding surfaces for complementing the plurality of guiding plates supported by the plate such that the slide is guided by the columns and the plurality of guiding plates on all sides parallel to a direction of the translational movement.