PROPELLER DRIVE ARRANGEMENT

Abstract

A propeller drive arrangement includes a propeller shaft, a planetary gear comprising a first planetary gear member, a second planetary gear member and a third planetary gear member which are drivingly connected, and an outer shaft arranged coaxially with and radially outside of the propeller shaft. The outer shaft is drivingly connected to one or more propeller blades for varying the pitch angle, and the propeller shaft is drivingly fixed to one of the planetary gear members and another one of the planetary gear members is arranged to drive the outer shaft by a driving torque exerted on the propeller shaft. The propeller drive arrangement has a pitch controlling member for varying the pitch angle of the one or more propeller blades, in a first state, to rotationally fix the third planetary gear member to the second planetary gear member so that the propeller shaft and the outer shaft are arranged to rotate with the same rotational speed, and, in a second state, to engage the third planetary gear member to a housing so that the third planetary gear member is rotationally fixed with respect to the housing.

Claims

1. A propeller drive arrangement, comprising: a propeller shaft, a propeller hub comprising one or more propeller blades, wherein a pitch angle of the one or more propeller blades is variable, a planetary gear comprising a first planetary gear member, a second planetary gear member and a third planetary gear member which are drivingly connected, and an outer shaft arranged coaxially with and radially outside of the propeller shaft, wherein the outer shaft is drivingly connected to the one or more propeller blades for varying the pitch angle, wherein the propeller shaft, in one end thereof, is configured to be drivingly connected to a propulsion unit and, in a second end thereof, is drivingly fixed to the propeller hub, and wherein the propeller shaft is drivingly fixed to one of the planetary gear members and wherein another one of the planetary gear members is arranged to drive the outer shaft by a driving torque exerted on the propeller shaft, and the propeller drive arrangement further comprising a pitch controlling member for varying the pitch angle of the one or more propeller blades, wherein the pitch controlling member is arranged to, in a first state, rotationally fix the third planetary gear member to the second planetary gear member so that the propeller shaft and the outer shaft are arranged to rotate with the same rotational speed, and, in a second state, engage the third planetary gear member to a housing so that the third planetary gear member is rotationally fixed with respect to the housing.

2. The propeller drive arrangement according to claim 1, wherein the first planetary gear member is a sun gear of the planetary gear.

3. The propeller drive arrangement according to claim 1, wherein the second planetary gear member is a planet gear carrier of the planetary gear carrying a plurality of planetary gear wheels.

4. The propeller drive arrangement according to claim 1, wherein the third planetary gear member is a ring gear of the planetary gear.

5. The propeller drive arrangement according to claim 1, wherein the third planetary gear member is a planet carrier of the planetary gear carrying a plurality of planetary gear wheels.

6. The propeller drive arrangement according to claim 5, wherein the second planetary gear member is a sun gear of the planetary gear.

7. The propeller drive arrangement according to claim 6, wherein the first planetary gear member is a ring gear of the planetary gear.

8. The propeller drive arrangement according to claim 1, wherein the pitch controlling member is a clutch member.

9. The propeller drive arrangement according to claim 8, wherein the clutch member is movable between the first state and the second state in any direction corresponding to a direction of a rotational axis of the propeller shaft.

10. The propeller drive arrangement according to claim 1, wherein the outer shaft is arranged to rotate one full revolution or more than one full revolution with respect to the propeller shaft.

11. The propeller drive arrangement according to claim 1, further comprising a first sensor for measuring rotational speed of the outer shaft and/or a second sensor for measuring rotational speed of the propeller shaft.

12. The propeller drive arrangement according to claim 11, further comprising a control unit arranged to receive signals from the first and second sensors which are indicative of rotational speeds of the propeller shaft and the outer shaft, wherein the control unit is configured to output a signal, based on the received signals from the sensors, which is indicative of a current pitch angle.

13. The propeller drive arrangement according to claim 1, further comprising a bevel gear arrangement drivingly connecting the outer shaft with the one or more propeller blades.

14. The propeller drive arrangement according to claim 1, wherein the propeller drive arrangement comprises only one planetary gear.

15. A vessel comprising a propeller drive arrangement according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

[0037] In the drawings:

[0038] FIG. 1 is a sectional view of a propeller drive arrangement according to an example embodiment of the present invention,

[0039] FIGS. 2a-b are enlarged sectional views of the propeller drive arrangement as shown in FIG. 1,

[0040] FIG. 3 is a sectional view of a propeller drive arrangement according to another example embodiment of the present invention,

[0041] FIGS. 4a-b are enlarged sectional views of the propeller drive arrangement as shown in FIG. 3,

[0042] FIG. 5 is a side view of a vessel according to an example embodiment of the present invention, and

[0043] FIG. 6 shows a table with different connection possibilities of a propeller drive arrangement according to the present invention.

[0044] The drawings are schematic and not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the disclosure is not limited to these embodiments. It shall also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the disclosure. Like reference characters throughout the drawings refer to the same, or similar, type of element unless expressed otherwise.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0045] FIG. 1 depicts a sectional view of a propeller drive arrangement 1 according to an example embodiment of the present invention. The propeller drive arrangement 1 comprises a propeller shaft 10. The sectional view is a plane including a rotational axis A of the propeller shaft 10.

[0046] The propeller drive arrangement 1 comprises: [0047] the propeller shaft 10, and [0048] a propeller hub 20 comprising one or more propeller blades 22, 24, wherein a pitch angle of the one or more propeller blades 22, 24 is variable.

[0049] The propeller drive arrangement 1 further comprises a planetary gear 30. The planetary gear 30 comprises a first planetary gear member 32, a second planetary gear member 34 and a third planetary gear member 36 which are drivingly connected. The planetary gear is coaxially arranged on the propeller shaft 10.

[0050] In the shown embodiment, the first planetary gear member 32 is a sun gear 32, the second planetary gear member 34 is a planet carrier 34 carrying a plurality of planetary gear wheels 342, and the third planetary gear member 36 is ring gear 36. The planetary gear wheels 342 are rotationally arranged on the planet carrier 34 and drivingly connect the sun gear 32 and the ring gear 36.

[0051] The propeller drive arrangement 1 further comprises an outer shaft 40 arranged coaxially with and radially outside of the propeller shaft 10. The outer shaft 40 is drivingly connected to the one or more propeller blades 22, 24 for varying the pitch angle.

[0052] The propeller shaft 10, in one end 12 thereof, is configured to be drivingly connected to a propulsion unit (not shown) and, in a second end 14 thereof, is drivingly fixed to the propeller hub 20.

[0053] The propeller shaft 10 is drivingly fixed to one of the planetary gear members, in this embodiment to the sun gear 32. Another one of the planetary gear members, in this embodiment the planet carrier 34, is arranged to drive the outer shaft 40 by a driving torque exerted on the propeller shaft 10. As shown in FIG. 1 the planet carrier 34 may be integrated with the outer shaft 40.

[0054] The propeller drive arrangement 1 further comprises a pitch controlling member 52 for varying the pitch angle of the one or more propeller blades 22, 24.

[0055] The pitch controlling member 52 is arranged to, in a first state, rotationally fix the third planetary gear member 36 to the second planetary gear member 34 so that the propeller shaft 10 and the outer shaft 40 are arranged to rotate with the same rotational speed, and, in a second state, engage the third planetary gear member 36 to a housing 60 so that the third planetary gear member 36 is rotationally fixed with respect to the housing 60.

[0056] When the propeller shaft 10 and the outer shaft 40 rotate with the same rotational speed, the pitch angle of the one or more propeller blades 22, 24 is fixed. In addition, when the third planetary gear member 36 is rotationally fixed with respect to the housing 60, the pitch angle of the one or more propeller blades 22, 24 is adjusted when also the propeller shaft 10 is rotating. Accordingly, the pitch angle is adjusted when the propeller shaft 10 and the outer shaft 40 rotate relative each other.

[0057] The pitch angle of each propeller blade 22, 24 is adjusted with respect to a respective pitch angle rotational axis A2, A3 of the respective propeller blade 22, 24. The pitch angle rotational axis A2, A3 of each propeller blade 22, 24 extends along a radial direction of the propeller shaft 10.

[0058] The pitch controlling member 52 may as shown in FIG. 1 be a clutch member, such as a friction clutch member or a dog clutch member.

[0059] FIGS. 2a-2b show enlarged views of the planetary gear 30 and the clutch member 52. FIG. 2a represents the second state and FIG. 2b represents the first state. The clutch member 52 is movable between the first state and the second state in any direction along the rotational axis A of the propeller shaft 10. The clutch member 52 may be moved by use of an actuator (not shown), such as by an electromechanical, pneumatic or hydraulic actuator.

[0060] Furthermore, in the shown embodiment, the outer shaft 40 is arranged to rotate one full revolution or more than one full revolution with respect to the propeller shaft 10. In other words, in the shown embodiment, the outer shaft 40 is freely rotatable with respect to the propeller shaft 10. The outer shaft 40 may be supported by bearings (not shown) provided in-between the propeller shaft 10 and the outer shaft 40. The bearings may be ball bearings or roller bearings.

[0061] As further shown in FIG. 1, the propeller drive arrangement 1 may further comprise a first sensor 72 for measuring rotational speed of the outer shaft 40 and/or a second sensor 74 for measuring rotational speed of the propeller shaft 10. The propeller drive arrangement 1 may further comprise a control unit 76 arranged to receive signals from the first and second sensors 72, 74 which are indicative of rotational speeds of the outer shaft 40 and the propeller shaft 10. The control unit 76 is configured to output a signal, based on the received signals from the sensors 72, 74, which is indicative of a current pitch angle.

[0062] The control unit 76 is an electronic control unit and may comprise hardware and/or software. The control unit 76 may be configured to update a value indicative of the current pitch angle every time a relative rotational speed of the outer shaft 40 and the propeller shaft 10 is registered. The updated value may be stored in a memory (not shown) associated with the control unit 76. As such, the current pitch angle is always known for a user. The control unit 76 may receive signals from the sensors 72, 74 via a wireless connection and/or a wired connection. The control unit 76 may also be configured to issue control signals to the above-mentioned actuator for controlling the clutch member 52.

[0063] As shown in FIG. 1, the propeller drive arrangement 1 may further comprise a bevel gear arrangement 44 drivingly connecting the outer shaft 40 with the one or more propeller blades 22, 24. Accordingly, a rotational motion about the axis A of the outer shaft 40 relative to the propeller shaft 10 can be translated to rotational motions of the propeller blades 22, 24 with respect to the pitch angle rotational axes A2, A3.

[0064] As further depicted in FIG. 1, the propeller drive arrangement 1 preferably comprises only one planetary gear 30, thereby enabling a compact, low-weight and cost-effective configuration.

[0065] FIGS. 3 and 4a-b show an alternative embodiment of a propeller drive arrangement 1 according to the invention.

[0066] The propeller drive arrangement 1 comprises: [0067] the propeller shaft 10, and [0068] a propeller hub 20 comprising one or more propeller blades 22, 24, wherein a pitch angle of the one or more propeller blades 22, 24 is variable.

[0069] The propeller drive arrangement 1 further comprises a planetary gear 30. The planetary gear 30 comprises a first planetary gear member 36, a second planetary gear member 32 and a third planetary gear member 34 which are drivingly connected. The planetary gear is coaxially arranged on the propeller shaft 10.

[0070] Accordingly, in this embodiment, the third planetary gear member is a planet carrier 34 of the planetary gear 30 carrying a plurality of planetary gear wheels 342. The second planetary gear member is a sun gear 32 of the planetary gear 30, and the first planetary gear member is a ring gear 36 of the planetary gear 30. The planetary gear wheels 342 are rotationally arranged on the planet carrier 34 and drivingly connect the sun gear 32 and the ring gear 36

[0071] The propeller drive arrangement 1 further comprises an outer shaft 40 arranged coaxially with and radially outside of the propeller shaft 10. The outer shaft 40 is drivingly connected to the one or more propeller blades 22, 24 for varying the pitch angle.

[0072] The propeller shaft 10, in one end 12 thereof, is configured to be drivingly connected to a propulsion unit (not shown) and, in a second end 14 thereof, is drivingly fixed to the propeller hub 20.

[0073] The propeller shaft 10 is drivingly fixed to one of the planetary gear members, in this embodiment to the sun gear 32. Another one of the planetary gear members, in this embodiment the ring gear 36, is arranged to drive the outer shaft 40 by a driving torque exerted on the propeller shaft 10. As shown in FIG. 3, the ring gear 36 may be integrated with the outer shaft 40.

[0074] The propeller drive arrangement 1 further comprises a pitch controlling member 52 for varying the pitch angle of the one or more propeller blades 22, 24.

[0075] The pitch controlling member 52 is arranged to, in a first state, rotationally fix the third planetary gear member 34 to the second planetary gear member 32 so that the propeller shaft 10 and the outer shaft 40 are arranged to rotate with the same rotational speed, and, in a second state, engage the third planetary gear member 34 to a housing 60 so that the third planetary gear member 34 is rotationally fixed with respect to the housing 60. Accordingly, in the first state, the third planetary gear member, i.e. the planet carrier 34, is rotationally fixed to the propeller shaft 10.

[0076] FIGS. 4a-4b show enlarged views of the planetary gear 30 and the clutch member 52 as shown in FIG. 3. FIG. 4a represents the second state and FIG. 4b represents the first state. The clutch member 52 is movable between the first state and the second state in any direction along the rotational axis A of the propeller shaft 10. The clutch member 52 may be moved by use of an actuator (not shown), such as an electromechanical, pneumatic or hydraulic actuator.

[0077] In similar with the above embodiment shown in FIG. 1, the propeller drive arrangement 1 may also as shown in FIG. 3 comprise a bevel gear arrangement 44, sensors 72, 74 and a control unit 76.

[0078] FIG. 5 depicts a side view of a vessel 100 according to an example embodiment of the invention. The vessel 100 is a marine vessel, and more particularly a sailing vessel comprising at least one sailing rig 110. The vessel 100 further comprises a propeller drive arrangement 1 according to an embodiment of the invention, such as the propeller drive arrangement 1 shown in FIG. 1 or FIG. 3. The propeller drive arrangement 1 may be used for generating a propulsion force by a propulsion unit 120, such as an electric motor. The propeller drive arrangement 1 may also be used for regenerating power to an electric energy storage system (not shown), e.g. a battery, when the vessel 100 is using the sailing rig 110 for generating the propulsion force. By varying the pitch angle during use of the vessel 100, the regenerative power generation and/or the propulsion force can for example be optimized for improved energy efficiency.

[0079] FIG. 6 depicts a table with different connection possibilities of a propeller drive arrangement according to the invention. Input in the left column represents which member of the planetary gear that is drivingly fixed to the propeller shaft. Output in the left column represents which other member of the planetary gear that is arranged to drive the outer shaft. Connection in the left column represents which two members of the planetary gear that should be rotationally fixed to each other in the first state. As depicted from the table, a total of eighteen combinations are possible to achieve.

[0080] It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.