Cycloidal Propeller Having Blades Which May Be Set Into a Sailing Position

1. Field of the Invention.

The invention relates a cycloidal propeller.

2. Description of the Related Art.

Cycloidal propellers serve mostly as marine major drives, but may be used also as an auxiliary drive, namely whenever especially high maneuverability is required. A cycloidal propeller is described in Voith reprint 9.94 2000. The wing mechanism serves to move the wings on the wing circle of the rotor in the necessary positions to both generate propulsion, and generate control forces. Feathering is effected by way of a central joystick, which is actuated by two servomotors arranged at right angles to one another. The rotor is generally powered via a gear drive comprising a bevel ring gear and a bevel pinion, frequently by a diesel engine.

DE-B 19 41 652 describes a cycloidal propeller serving only as marine auxiliary drive and which at cruising travel of the ship is operated exclusively as a rudder. Feathering of the individual wings is effected by suitable accessory apparatuses to a degree such that in the so-called nonbuoyant, i.e., nonpropelling sailing position, they are parallel to one another and can in this position be adjusted to the necessary angular position by rotation of the rotor element according to the required rotor position.

DE 36 06 549 concerns a variant of a cycloidal propeller, which features a multiple-part wing. Safe and reliable actuation of the individual wing parts requires special measures, to which end a gear drive is provided, since the pivoting direction of the wing parts is easy to bring about with a number of gear wheels.

DE 196 02 043 C1 is an older, unpublished document.

But the design of the cycloidal propeller, notably concerning the configuration of the propeller mechanism and attachment to the wing shaft, results in relatively short feathering paths of the wings. Therefore, it is not possible to bring the rounded head end of the wings in a forward direction of travel. Therefore, wing profiles are used that deviate from the usual shape and have an essentially oval shape. At certain states of travel this is unfavorable, however, for example when the ship travels within narrow channels, for example in harbors or in the skerries. In such states of travel, it is advantageous to drive the ship using the cycloidal propeller, and not the main drive, which is configured for a considerably higher speed. The high maneuverability of the cycloidal propeller is utilized here.

The invention includes a cycloidal propeller comprising a stator and a rotor mounted rotatably to the stator. The rotor having an axis of rotation and a plurality of wings having shafts pivotally mounted to the rotor with a swivel axis. The rotor axis of rotation and the swivel axes of the wings are substantially parallel to each other. A propeller mechanism is included for actuation of the wings using a joystick connected to the wings by a linkage.

An accessory apparatus is connected to the wings, causing actuation of the wings to a sailing position where the wings are parallel to each other. The accessory apparatus is also able to actuate the wings from a sailing position to a rudder position. A gear drive is also provided for engaging the accessory apparatus to the wings.

The objective of the invention is to create a cycloidal propeller with which large pivoting angles are possible so as to achieve sailing position, thus allowing the use of a normal wing profile that has a thicker, rounded head part and a more slender tail end.

Due to the inventional measure, relatively small actuating movements of the hydraulic cylinder enable large pivoting angles of the wings in conjunction with the gear ratio of the gear drive.

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a basic plan view of the rotor of the cycloidal propeller with the propeller mechanism in normal position, i.e., for cruising operation;

FIG. 2 is a corresponding view with the wings in sailing position;

FIG. 3 is the controller in rudder operation (propeller with servo drive mechanism; and

FIG. 4 is an elevetional view of a prior art cycloidal propeller with a stator 200.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

Moving in cruising operation, i.e., propulsion of the ship, on wing circle a, wings are referenced 1 in FIG. 1. The propeller mechanism is referenced 2, the joystick being in the zero position, in which the profile chords extend generally tangentially to the wing circle a. Installed in the mechanism is a hydraulic cylinder 5 each, which here practically replaces most of coupling rod 19. The ram of the hydraulic cylinder is hinged to gear segment 4, which with its teeth meshes with the gear 3 mounted on the wing shaft.

Allowing appropriately large selection, the gear ratio of the gear drive produces a large pivoting angle of the wings.

To switch from cruising operation to rudder operation of the cycloidal propeller, the latter is shut off and locked at a specific spot, preferably with one of the wings, as shown here, on the rotor diameter that extends perpendicularly to the longitudinal axis of the ship. This provides a suitable basis for activating the individual wings accordingly with the hydraulic cylinder.

FIG. 3 shows schematically a cycloidal propeller and the diagram of its controller. Major components are:

The connections of the controller diagram are illustrated a single wing, but they are identical for all five wings.

In normal propeller operation, hydraulic cylinders 5 are locked in the zero position and thus transmit the motions generated by the mechanism to the wings. An oil supply intergrated in the rotor compensates for leakage losses of the hydraulic cylinders, ensuring that their zero position is maintained always. Energy is supplied either via an accumulator, which is charged always at rotor standstill, or via an oil pump inshalled in the rotor and driven mechanically.

In the rudder operation, the rotor is at standstill. The quick-action couplings are now closed, establishing a connection of the hydraulic cylinders 5 to their respective oil supplies. In the simplest case, the quick-action couplings are closed manually. But the procedure can be automated easily (for example, by way of a hydraulically or pneumatically actuated apparatus. The same is true for the electrical connection to the displacement transducers contained in the hydraulic cylinder. Here, too the electrical connection is required not until the rotor is at standstill.

Stopping and blocking the rotor may be envisaged as follows:

The rotor features a cam for activation of a limit switch on the stator. As the propeller is shut down, the rotor stops at any point, but continues to be rotated then until the cam actuates the limit switch. Next, the propeller is locked against further rotation on the propeller input shaft, for example, by means of a disk brake or a plain mechanical lockout. The joystick is kept at a zero position by an electrically powered oil pump.

The propeller is, in normal operation, controlled via a known standard controller.

In the rudder operation, with the rotor at standstill, control is effected with the aid of a handwheel, which by means of a rotary potentiometer feeds control pulses to a stored program controller. The output signals control solenoid valves, which, in turn, effect the control of the hydraulic cylinders, and thus the required wing actuation. The control procedure can also be automated, using a signal from the ship's compass.

Accomplished with the proposed invention is a genuine sailing position, and additional rudder angles can be adjusted. That is, the propeller is thus a genuine substitute for an additional rudder, since all of the wings are rotated by a common angle, thus generating a thrust in a desired direction.

The overall system may be designed such that maximum wing deflections are given with the hydraulic cylinder rams in their limit positions.

While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.