Abstract:
The invention relates t a Z-drive for a watercraft, said drive comprising an upper part, a lower part and a propeller. At least the propeller can be moved by means of a clutch housing, a cardan housing, and a trim cylinder. An intermediate part is arranged between the clutch housing and the Z-drive, enabling the Z-drive to be laterally pivoted in relation to the watercraft. The intermediate part enables the immersion depth of the propeller to be adjusted by pivoting the drive, and the trim standard of the Z-drive is independently adopted in a serviceable manner.

Description:
TECHNICAL FIELD  
       [0001]     The invention relates to a Z-drive for a watercraft as specified in the preamble of the first claim.  
       PRIOR ART  
       [0002]     Variation of the immersion depth of propellers, a critical component of the travel speed of a watercraft when planing, is achieved by a variety of methods.  
         [0003]     For example, in the case of surface-propeller drive units having a rigid propeller shaft, as specified in U.S. Pat. No. 4,746,314, this is achieved by the craft&#39;s speed, whereby hydroplaning of the hull changes when transitioning from displacement travel to planing travel, that is, at slow speed the propeller is thus situated in a fully submerged state, while when planing it is situated in a partially submerged state.  
         [0004]     In addition, U.S. Pat. No. 4,645,463 and U.S. Pat. No. 5,666,415 disclose surface drive units in which the immersion depth of the propeller is achieved by trimming the propeller shaft—with the disadvantage that the propeller, or hull, necessarily occupies a possibly undesirable trim angle.  
         [0005]     U.S. Pat. No. 4,371,350 similarly discloses a method whereby a flap valve on the watercraft is used to control the water flow, and thus the immersion depth of the propeller—with the disadvantage of a rigid propeller shaft.  
         [0006]     Also known, especially for outboard drive units, are means—usually offered as accessory equipment—by which the propellers operate fully submerged at low speeds, while at high travel speeds they can be manually raised to a partially submerged mode by vertically lifting the entire outboard unit by means of an electrohydraulic system.  
         [0007]     In the case of widely available Z-drives, trimming can also be used to change the height of the propeller theoretically be a few centimeters—however, at the same time the propeller trim is changed in an unfavorable manner.  
       DESCRIPTION OF THE INVENTION  
       [0008]     The goal of the invention is to avoid the disadvantages of the prior art in a Z-drive for a watercraft of the species referenced above, while presenting a method whereby in Z-drives specifically the propeller immersion depth, that is, the height adjustment of the propeller relative to the craft&#39;s hull, or the water immersion depth, can be set for different states of the craft, yet independently of the trim of the Z-drives.  
         [0009]     According to the invention, this goal is achieved by the features of the first claim.  
         [0010]     The core of the invention is an intermediate piece which provides the immersion depth of the propeller by swiveling the drive unit, while independently therefrom also reliably providing the standard trim for the Z-drive.  
         [0011]     The advantage of the invention consists in the simple implementability and simple introduction of a means of this type into the Z-drive system. The intermediate piece is located in compact form between the Z-drive bell-housing and the Z-drive itself, and contains the pivoting device for the Z-drive, the electrical or hydraulic drive unit, the associated optional angle transmitter, and the bracket of the trim cylinder(s).  
         [0012]     The intermediate piece further comprises an intermediate housing which is attached to the bell-housing, or may be implemented as an integrated component of the bell housing. The Z-drive thus dispenses with the trim cylinder; this may now be fabricated in a short-shaft or short-stroke design, whereby in order to reliably raise the Z-drive, for example, in shallow waters, this component is now pivoted away from the danger zone laterally by a pivot motor.  
         [0013]     Additional advantageous embodiments of the invention are found in the subclaims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The following discussion explains embodiments of the invention in more detail based on the drawings. Identical elements in the various figures are provided with identical reference notations.  
         [0015]      FIG. 1  is a schematic rear view of the Z-drive according to the invention, with laterally pivotable kinematics and a possible immersion depth position, indicated by the broken lines;  
         [0016]      FIG. 2  is a schematic side view of a Z-drive and possible trim position, indicated by the broken lines;  
         [0017]      FIG. 3  is a schematic cross-section in the area of the intermediate piece;  
         [0018]      FIG. 4  is a plan view of a watercraft according to the invention. 
     
    
       [0019]     Only those elements essential to the immediate understanding of the invention are shown. Not shown are, specifically, seals, drive shafts with associate bearings, oil, cooling water and exhaust gas ductings from the Z-drive to the motor.  
       Means of Implementing the Invention  
       [0020]      FIG. 1  is a is a schematic rear view of the Z-drive  30  which comprises a Z transmission upper section  2 , a Z transmission lower section  3 , and a propeller  4 , and which is radially pivotably flange-mounted to an intermediate piece  1  including an integrated pivot motor  5  and a trim cylinder  6 . The possible radial pivoting of Z-drive  30  is demonstrated by the broken line; the immersion depth of the propeller in the water is represented by the waterline X.  
         [0021]      FIG. 2  is a schematic side view of Z-drive  30 , wherein intermediate piece  1  is located between the Z-drive and a bell-housing  7 . Bell-housing  7  is retained by a cardan housing.  8 , and enables bell-housing  7  and the components located behind it to rotate about the axis A perpendicular to the plane of the drawing, and simultaneously about the axis B to control Z-drive  30  so as to effect a rudder function. The rotational motion about axis A is provided by trim cylinder  6  which is supported by intermediate piece  1  and cardan housing  8 . The immersion depth of the propeller in the water is represented by the waterline X.  
         [0022]      FIG. 3  shows a schematic cross-section in the area of intermediate piece  1 . Intermediate piece  1  comprises an intermediate housing  24 , an inner pivot tube  10 , bearings  12 , tube bracket  13 , and the pivot motor  5 . In this view, only the upper transmission section  2  of Z-drive  30  is shown, which transmission section is fixedly fastened by bolts  9   a  to the rotatably mounted to the inner pivot tube  10 . Inner pivot tube  10  has at one location a shoulder  11  which is supported by axial bearing  12  against intermediate housing  24  and a tube bracket  13 , whereby tube bracket  13  additionally prevents any axial shift of inner pivot tube  10 , and thus enables the bearing clearance to be adjusted as well. Tube bracket  13  and/or intermediate housing  24  also have at least one radial bearing  14  providing low-friction pivoting for inner pivot tube  10 , or Z-drive  30 .  
         [0023]     On shoulder  11  is mounted a gear ring  15  which is able to be put into motion by a pinion  16 . Pinion  16  is driven by pivot motor  5  which may be driven either electrically or hydraulically. Appropriate gear pairs, for example, worm gears or other means may be used to implement the pivot mechanism in self-locking form. Hydraulic or electrical lines  17  are extended from intermediate piece  1  into the interior of the watercraft. As an option, an angle transmitter  18  may be installed in intermediate piece  1 , which transmitter may be connected to pinion  16 , pivot motor  5 , shoulder  11 , or other components not shown, thereby indicating the exact position of propeller  4 . A flexible cable  19  is used to route angle transmitter  18  from within intermediate piece  1  into the watercraft, thereby providing a display or a value for the algorithm used to control the propeller position or the watercraft.  
         [0024]     Intermediate housing  24  is fastend by bolts  9   b  to bell-housing  7 . Intermediate housing  24  may also be integrated into bell-housing  7 , specifically, in a single-piece design. Bell-housing  7  is connected to cardan housing  8  by being pivotably mounted at site A, which in turn is pivotably mounted at site B, for example, to a support housing not shown, or directly to the hull of the watercraft. Intermediate piece  1  is connected by intermediate housing  24  through trim cylinder  6  to cardan housing  8 , thus enabling Z-drive  30  to be raised for trimming. Most Z-drives have a trim sensor which is integrated at site A, and can thus be retained.  
         [0025]     Also shown schematically are transmission gears  20  and a shaft  21  which passes through inner pivot tube  10 , intermediate housing  24 , bell-housing  7 , and is connected to motor shaft  22 , a not-shown cardan joint being located at site A to provide the diffraction angle for the shaft—through pivot A when trimming, and through pivot B when steering.  
         [0026]     In addition, a separate line  23  is shown schematically which is intended to represent the lines for oil, cooling water, blade adjustment for an adjustable propeller, or coupling and exhaust-gas ducting.  
         [0027]     Swiss patent application no.2002 2041/02, the disclosure of which is herewith incorporated by reference, shows laterally pivotable drive units which enable, with little complexity/expense, to combine the advantages of propeller immersion depth with propeller trimming in one integrated housing.  
         [0028]      FIG. 4  illustrates a watercraft  31 , having a hull  32 , drive unit  30 , and associated propeller  4 . The motor located in the stem of watercraft  31  is not shown. The motor is connected by a shaft, also not shown, to drive unit  30  which is located at stern side  35  of hull  32 , and which may have, for example, multiple shafts and bevel gear pairs. An example of an operating position for propeller  4  is shown on the right-hand side of  FIG. 4 . On the left-hand side, the propeller is shown pivoted laterally upward such that the propeller comes to rest at least partially in the area of a water intake  36  located on or in hull  32 , and having a water intake opening  37  and water outlet opening  38 .  
         [0029]     The pivoting of propeller  34  may be triggered either manually or automatically by a specific event. The pilot may, for example, set various pivot positions as desired by a switch on the controls, or pivoting can be implemented by electronic controls which respond to different parameters, for example, the water depth, speed of the motor, etc.  
         [0030]     The water intake  36  to provide the appropriate flow to the propeller may be located on the lateral side of the boat in the form of closed channel in the hull, as illustrated on the right-hand side of  FIG. 4 , or as a cut-out section, as shown on the left-hand side of  FIG. 4 , which is located in the hull of the watercraft in order to provide the appropriate flow to the propeller. Water intake  36 , or water intake opening  38 , may be either open of closed, that is, appropriate flap valves cover the water inlet opening when not in use, or such flap valves are not present at all, as is the case for the cut-out section in the hull of the watercraft, shown on the left in  FIG. 4 .  
         [0031]     Use of the radially pivotable drive unit  30 , and thus propeller  4 , provides for a space-saving underwater drive unit having an unchanged thrust direction for the propeller in any pivot position. Thus, in the case of shallow water, drive unit  30  may be pivoted laterally until it reaches the level of water intake  36 . The water required for propeller thrust is thus no longer taken in below the hull of the watercraft, but instead essentially behind and protected by stem side  35  of watercraft  31 , such that travel may be continued at locations which would otherwise be impassable for watercraft with a Z-drive due to the shallow water.  
         [0032]     The water intake thus has advantages and power output analogous to that of a jet drive system. An additional advantage is the fact that the propeller is protected from striking the bottom, while also allowing eelgrass to be easily removed from the open propeller region—for example, by laterally moving the drive unit further upward until drive unit  30  and propeller  4  actually emerge above the surface of the water.  
         [0033]     Drive unit  30  together with the propeller may additionally be designed to pivot longitudinally, that is, in the longitudinally/in the direction of the watercraft&#39;s axis. This longitudinal pivoting by a few degrees of angle, also known as trimming, helps keep the bow of the watercraft steady in rough water, or to make it faster.  
         [0034]     The invention solves the problem of a large space requirement at the stern of the watercraft. While Z-drives do not have the space problem in the cockpit, the thrust angle change, as well as the additional space requirement at the stern when the drive unit is swung upward, remain.  
         [0035]     The function whereby the underwater drive unit can be pivoted through a large angular zone without loss of power permits the propeller also to be operated as a surface-propeller drive unit, that is, when underway the propeller is only partially submerged when used, and may be employed in high-speed watercraft.  
         [0036]     For this purpose, a modified section is employed which is located above the waterline during planing, and to the end of which is attached the pivoting component for the underwater drive unit.  
         [0037]     In the pivoted-up position, the water intake or opening to the propeller may be either open or closed, that is, appropriate flaps valves cover the water inlet when not in use; or such flaps are not even present, but instead a cutout is located in the hull of the watercraft providing a suitable means of flow to the propeller. The water intake opening may be located on the lateral side or within the bottom region of the watercraft, as governed by the power input of the drive unit.  
         [0038]     It is understood that the invention is not limited to the embodiment shown and described here.  
       List of Reference Notations  
       [0000]    
       
           1  intermediate housing 1      1  Translator&#39;s note: reference number also applied to “intermediate piece.”   
           2  upper transmission section  
           3  lower transmission section  
           4  propeller  
           5  pivot motor  
           6  trim cylinder  
           7  bell-housing  
           8  cardan housing  
           9   a  bolts from 2 to 10  
           9   b  bolts from 1 to 27  
           10  inner pivot tube  
           11  shoulder  
           12  axial bearing  
           13  tube bracket  
           14  radial bearing  
           15  gear ring  
           16  pinion  
           17  lines  
           18  angle transmitter  
           19  cable  
           20  transmission gears  
           21  shaft  
           22  motor shaft  
           23  separate line  
           20  intermediate housing  
           30  Z-drive  
           31  watercraft  
           32  hull  
           35  stem side  
           36  water intake  
           37  water intake opening  
           38  water outlet opening  
          A trim axis  
          B steering axis  
          X waterline