Apparatus and method for rotating a shaft

Abstract

Turning gear apparatus (10) for rotating a shaft (11) comprises a rotary drive arrangement (12) and a transmission system including a pivot arm (20). The rotary drive arrangement (12) is fixed, for example to a vessel hull (14), and the pivot arm (20) is pivotable between a first, shaft-disengaged, position and a second, shaft-engaged position where the rotary drive arrangement (12) is operably coupled to the shaft (11), thereby permitting control over rotation of the shaft (11) by the rotary drive arrangement (12).

Claims

1. Turning gear apparatus for rotating a shaft, the apparatus comprising: a rotary drive arrangement adapted to be fixed to a vessel hull; a transmission system coupled to the rotary drive arrangement, the transmission system comprising a pivot arm adapted to be pivoted about a pivot axis to engage the transmission system with the shaft to permit rotation of the shaft by the rotary drive arrangement, a first driven member coupled to and adapted for rotation by the rotary drive arrangement, and a second driven member adapted to be driven by the first driven member; and an actuator for pivoting said pivot arm about said pivot axis between a first position and a second position, and vice versa, wherein said pivot arm is disposed about said pivot axis, said pivot axis being co-linear with a drive shaft axis of said rotary drive arrangement, wherein a first part of said pivot arm is disposed on one side of said drive shaft axis and a second part of said pivot arm is disposed on an opposing side of the drive shaft axis from said first part of said pivot arm, wherein said actuator is physically coupled to said first part of said pivot arm and the second driven member is disposed on said second part of said pivot arm, wherein the actuator is coupled to a lower portion of the pivot arm and configurable to pivot the pivot arm so that a driven member rotatably coupled to an upper portion of the pivot arm engages with the shaft to permit rotation or the shaft by the rotary drive arrangement.

2. The apparatus of claim 1, wherein the rotary drive arrangement is operably coupled to the transmission system via the first driven member.

3. The apparatus of claim 1, wherein the first and second driven members are engaged to facilitate alignment between the second driven member and the shaft during pivoting of the transmission system relative to the shaft.

4. The apparatus of claim 1, wherein the second driven member is adapted to orbit the first driven member on pivoting of the transmission system.

5. The apparatus of claim 1, wherein each of the first and second driven members comprises a gear.

6. The apparatus of claim 1, wherein the second driven member is adapted to engage a further driven member on the shaft.

7. The apparatus of claim 6, wherein the further driven member comprises a gear provided on the shaft, whereby rotation of the second driven member drives rotation of the shaft.

8. The apparatus of claim 1, wherein the actuator is selected from the group consisting of: a screw jack; a hydraulic ram; and a pneumatic actuator.

9. The apparatus of claim 1, wherein the actuator is fixed to a mounting bracket of the apparatus.

10. A method of rotating a shaft, the method comprising: providing a turning gear apparatus comprising: a rotary drive arrangement adapted to be fixed to a vessel hull; a transmission system coupled to the rotary drive arrangement, the transmission system comprising a pivot arm adapted to be pivoted about a pivot axis to engage the transmission system with the shaft to permit rotation of the shaft by the rotary drive arrangement, a first driven member coupled to and adapted for rotation by the rotary drive arrangement, and a second driven member adapted to be driven by the first driven member; and an actuator for pivoting said pivot arm about said pivot axis between a first, disengaged, position and a second, shaft-engaging, position, and vice versa, wherein said pivot arm is disposed about said pivot axis, said pivot axis being co-linear with a drive shaft axis of said rotary drive arrangement, wherein a first part of said pivot arm is disposed on one side of said drive shaft axis and a second part of said pivot arm is disposed on an opposing side of the drive shaft axis from said first part of said pivot arm, wherein said actuator is physically coupled to said first part of said pivot arm and the second driven member is disposed on said second part of said pivot arm, wherein the actuator is coupled to a lower portion of the pivot arm so that a driven member rotatably coupled to an upper portion of the pivot arm engages with the shaft to permit rotation of the shaft by the rotary drive arrangement; pivoting said pivot arm between said first, disengaged, position and said second, shaft engaging, position using said actuator; and operating said rotary drive arrangement to permit rotation of the shaft via the transmission system.

11. The method of claim 10, comprising moving the transmission system between the first, disengaged, position and the second, engaged, position in a single stage.

12. The method of claim 10, comprising moving the transmission system between the first, disengaged, position and the second, engaged, position in a plurality of stages.

13. The method of claim 10, comprising synchronising at least one of: rotation of the drive arrangement, rotation of the first driven member, rotation of the second driven member, pivoting of the transmission system and rotation of the shaft.

14. The method of claim 10, wherein the actuator is selected from the group consisting of: a screw jack; a hydraulic ram; and a pneumatic actuator.

15. The method of claim 10, wherein the actuator is fixed to a mounting bracket of the apparatus.

16. The method of claim 10, comprising pivoting said pivot arm between said second position and said first position using said actuator, wherein the actuator is configured, via said physical coupling between said actuator and said pivot arm, to transmit a moment force which pivots said pivot arm in a second rotational direction about said pivot axis in order to disengage said transmission system from said shaft.

17. Turning gear apparatus for rotating a shaft, the apparatus comprising: a rotary drive arrangement adapted to be fixed to a vessel hull; a transmission system coupled to the rotary drive arrangement, the transmission system comprising a pivot arm adapted to be pivoted about a pivot axis to engage the transmission system with the shaft to permit rotation of the shaft by the rotary drive arrangement, a first driven member coupled to and adapted for rotation by the rotary drive arrangement, and a second driven member adapted to be driven by the first driven member; an actuator for pivoting said pivot arm about said pivot axis between a first position and a second position, and vice versa; and a control system for controlling engagement between engagement between the apparatus and the shaft to be rotated, the control system comprising speed sensors adapted to facilitate synchronisation of the apparatus and the shaft, wherein said pivot arm is disposed about said pivot axis, said pivot axis being co-linear with a drive shaft axis of said rotary drive arrangement, wherein a first part of said pivot arm is disposed on one side or said drive shaft axis and a second part of said pivot arm is disposed on an opposing side of the drive shaft axis from said first part of said pivot arm, and wherein said actuator is physically coupled to said first part of said pivot arm and the second driven member is disposed on said second part of said pivot arm a control system for controlling engagement between the apparatus and the shaft to be rotated, the control system comprising speed sensors adapted to facilitate synchronization of the apparatus and the shaft.

18. A method of rotating a shaft, the method comprising: providing a turning gear apparatus comprising: a rotary drive arrangement adapted to be fixed to a vessel hull; a transmission system coupled to the rotary drive arrangement, the transmission system comprising a pivot arm adapted to be pivoted about a pivot axis to engage the transmission system with the shaft to permit rotation of the shaft by the rotary drive arrangement, a first driven member coupled to and adapted for rotation by the rotary drive arrangement, and a second driven member adapted to be driven by the first driven member; and an actuator for pivoting said pivot arm about said pivot axis between a first, disengaged, position and a second, shaft-engaging, position, and vice versa, wherein said pivot arm is disposed about said pivot axis, said pivot axis being co-linear with a drive shaft axis of said rotary drive arrangement, wherein a first part of said pivot arm is disposed on one side of said drive shaft axis and a second part of said pivot arm is disposed on an opposing side of the drive shaft axis from said first part of said pivot arm, and wherein said actuator is physically coupled to said first part of said pivot arm and the second driven member is disposed on said second part of said pivot arm; and a control system for controlling engagement between the apparatus and the shaft to be rotated, the control system comprising speed sensors adapted to facilitate synchronisation of the apparatus and the shaft; pivoting said pivot arm between said first, disengaged, position and said second, shaft engaging, position using said actuator; and operating said rotary drive arrangement to permit rotation of the shaft via the transmission system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the present invention will now be described with reference to the accompanying drawings, in which:

(2) FIG. 1 is a diagrammatic longitudinal cross-sectional view of an apparatus for rotating a shaft according to an embodiment of the present invention;

(3) FIG. 2 is a perspective view of the apparatus of FIG. 1;

(4) FIG. 3 is an alternative perspective view of the apparatus of FIGS. 1 and 2;

(5) FIG. 4 is a cross-sectional view of a portion of the apparatus of FIGS. 1 to 3, the apparatus shown in a first, disengaged, position relative to a shaft;

(6) FIG. 5 is a cross-sectional view of the portion of the apparatus of FIG. 4, the apparatus shown in a second, engaged, position relative to the shaft;

(7) FIG. 6 is a perspective view of an apparatus for rotating a shaft according to an alternative embodiment of the present invention; and

(8) FIG. 7 is a perspective view of an apparatus for rotating a shaft according to a further alternative embodiment of the present invention;

DETAILED DESCRIPTION OF THE DRAWINGS

(9) FIGS. 1 to 5 show turning gear apparatus 10 in accordance with an embodiment of the present invention. The apparatus 10 is adapted to engage and rotate a shaft, such as a propeller shaft 11 (FIGS. 4 and 5) of a sea-going vessel.

(10) With reference to FIGS. 1 to 3, the apparatus 10 comprises a rotary drive arrangement in the form of a hydraulic motor 12 which is fixed to a vessel hull 14 via a base bracket 16. The bracket 16 is secured to the hull 14 by a bolted connection 18, though any suitable arrangement for securing the bracket 16 may be used.

(11) The apparatus 10 further comprises a transmission system which includes a pivot arm 20 coupled to the bracket 16 by a bearing 22. The bearing 22 comprises a radial bearing, though any suitable bearing member may be employed and the pivot arm 20 is thus adapted for rotational movement about a pivot axis 24.

(12) The apparatus 10 further comprises a first driven member in form of a pinion gear 26 mounted on a drive shaft 28 of the motor 12. The motor drive shaft 28 extends towards the pivot arm 20 and defines a drive shaft rotational axis 30. In the embodiment shown in the drawings, the pivot axis 24 and drive shaft axis 30 are co-linear and the first pinion gear 26 is adapted for rotation about the pivot arm axis 24/drive shaft axis 30.

(13) The transmission system also includes a driven member in the form of a second pinion gear 32. The second pinion gear 32 is rotatably mounted on the pivot arm 20 by a radial bearing 34 and is arranged so that the second driven member 32 meshes with the first pinion gear 26.

(14) As shown in FIGS. 2 and 3, the pivot arm 20 forms an enclosure or hood over the first and second pinion gears 26, 32 which assists in protecting the gears 26, 32.

(15) The apparatus 10 further comprises an actuator in the form of a screw jack 36a fixed to the bracket 16. The screw jack 36a comprises a threaded portion or screw 38 which is adapted to engage a corresponding threaded portion 40 on the pivot arm 20.

(16) The apparatus 10 further comprises a control system 42 (shown schematically in FIG. 3) for controlling movement and synchronisation of the motor 12, pivot arm 20, pinion gears 26, 32 and screw jack 36a with the shaft to be rotated.

(17) The control system 42 comprises sensors 44 for monitoring the speed of rotation of the components of the apparatus 10 to facilitate engagement between the apparatus 10 and the shaft. Communication signals between the control system 42, sensors 44 and apparatus 10 may be of any suitable form including for example, electrical signals, optical signals, wireless signals, radio frequency signals or the like.

(18) Referring now in particular to FIGS. 4 and 5 of the drawings, the apparatus 10 initially defines a first, disengaged, position relative to the shaft 11, the first position shown in FIG. 4. In operation, the motor 12 drives rotation of the first pinion gear 26 about the axis 30 (FIG. 1). The first pinion gear 26 is in mesh with the second pinion gear 32 such that rotation of the first pinion gear 26 in turn rotates the second pinion gear 32.

(19) Due to the inter-engaging threads of the screw 38 and threaded portion 40 of the pivot arm 20, rotation of the screw 38 causes the threaded portion 40 to walk along the screw 38, thereby producing a moment on the pivot arm 20. Accordingly, the pivot arm is rotated about axis 24 (FIG. 1) from the first disengaged position shown in FIG. 4 to a second, engaged, position as shown in FIG. 5.

(20) As the motor 12 is fixed to the vessel hull 14, reaction loads from any shock loads in the arm are low, reduced or substantially eliminated. Any overturning moment on the pivot arm 20 and pivot arm bearing 22 is also low, reduced or eliminated. Furthermore, any overturning load transmitted through the bracket 16 to the bolted connection 18 is low, reduced or eliminated.

(21) As the pivot arm 20 pivots, the second pinion gear 32 moves around or orbits the first pinion gear 26 and moves from the first, disengaged position to engage with and mesh with a ring gear 13 on the shaft 11. As an example, where the pitch circle diameter (PCD) of the pinion gears 26, 32 is about 288 mm and the pinion gear disengagement travel is about 70 mm, the pivot arm 20 will rotate about 14 degrees and the screw jack 36a will have a stroke of about 105 mm.

(22) On engaging the ring gear 13, the shaft 11 is rotated by the motor 12 via the first and second pinion gears 26, 32 and the shaft ring gear 13.

(23) During engagement and disengagement of the apparatus 10 with the shaft ring gear 13, the motor 12 is operated in a low pressure looped mode to assist in avoiding binding of the gear teeth.

(24) The control system 42 matches the rotational speed of the second driven member 32 to the shaft/shaft ring gear 13 to facilitate engagement between the apparatus 10 and the shaft 11. In one embodiment, the control system 42 is adapted to facilitate engagement between the apparatus 10 and the shaft 11 in a single stage. Alternatively, the control system 42 may be adapted to facilitate engagement between the apparatus 10 and the shaft 11 in a plurality of stages. Each stage may involve processing feedback information from speed sensors located on the apparatus 10 and the shaft 11.

(25) Those of skill in the art will recognise that the illustrated apparatus is merely exemplary of the present invention and that the same objectives may be achieved by using a variety of different configurations.

(26) For example, while the present invention is described for use in respect of the shaft of a sea-going vessel, the invention can be used to rotate any shaft.

(27) As shown in the Figures, a single turning gear apparatus may be used to engage and rotate the shaft. Alternatively, a plurality of turning gear apparatus may be used to rotate the shaft. For example, two turning gear apparatus may be positioned on either side of an end of the shaft. Alternatively, or in addition, turning gear apparatus may be positioned at spaced locations along the length of the shaft or at respective ends of the shaft, where appropriate.

(28) The apparatus may be adapted to engage the shaft to permit control over rotation of the shaft. For example, the transmission system may be adapted to engage the shaft to permit the shaft to be rotated from rest, thereby reducing the start-up torque required to initially rotate the shaft prior to engagement of a turbine or other drive. Alternatively, or in addition, the transmission system may be adapted to engage the shaft to permit the shaft to be decelerated and/or held stationary for example to facilitate repair or maintenance of the shaft as required.

(29) FIG. 6 shows an apparatus 10b according to an alternative embodiment of the present invention. The apparatus 10b is identical to the apparatus 10 shown in FIGS. 1 to 5 with the exception that the actuator comprises a hydraulic ram 36b.

(30) FIG. 7 is a perspective view of an apparatus 10c according to a further alternative embodiment of the present invention. The apparatus 10c is identical to the apparatus 10 shown in FIGS. 1 to 5 with the exception that the actuator comprises a pneumatic actuator 36c.