Abstract:
Provided is a compact generator mounting arrangement for vertical engines and outboard marine drives. The generator is mounted via brackets integrally cast with the crankcase of the engine. The brackets can be conveniently reinforced by a hollow ridge which is integrally cast with said crankcase to define an oil gallery therein. Thus, sturdy generator mounting brackets can be formed without increasing the cost and weight.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to a generator mounting arrangement for vertical engines and a generator mounting arrangement for outboard marine drives equipped with a vertical engine.  
         BACKGROUND OF THE INVENTION  
         [0002]    A large outboard marine engine is typically equipped with a generator in the form of an ACG. An ACG is typically secured to a cylinder block or crankcase via steel brackets. Japanese patent laid open (kokai) publication No. 10-175596 filed by the same applicant discloses an arrangement in which a relatively large bracket is secured to an upper end of the crankcase to thereby support an ACG. However, the bracket is subjected to the tension that acts upon the ACG drive belt, and is required to support the relatively heavy ACG as a cantilever so that the bracket tends to be large in size. Furthermore, because the bracket is attached to the crankcase having a limited mechanical strength to withstand the load, a relatively large mounting area must be secured in the crankcase and/or the crankcase is required to be reinforced.  
         BRIEF SUMMARY OF THE INVENTION  
         [0003]    In view of such problems of the prior art, a primary object of the present invention is to provide a generator mounting arrangement for vertical engines which is highly compact, and a generator mounting arrangement for an outboard marine drive equipped with such an engine.  
           [0004]    A second object of the present invention is to provide a generator mounting arrangement for vertical engines which is economical to implement, and a generator mounting arrangement for an outboard marine drive equipped with such an engine.  
           [0005]    A third object of the present invention is to provide a generator mounting arrangement for vertical engines which is light in weight, and a generator mounting arrangement for an outboard marine drive equipped with such an engine.  
           [0006]    According to the present invention, such objects can be accomplished by providing a generator mounting arrangement for vertical engines having a substantially vertically oriented crankshaft, a cylinder block having a cylinder axial line disposed substantially horizontally, a cylinder head attached to a corresponding side of the cylinder block to define a combustion chamber, a crankcase fixedly attached to another side of the cylinder block to define a crank chamber accommodating the crankshaft, a generator fixedly attached to an outer side of the crankcase and having an input shaft extending vertically upward, a driven pulley secured to the generator input shaft, a drive pulley attached to an upper end of the crankshaft, and an endless belt passed around the two pulleys, wherein: the generator is fixedly attached to the crankcase via a bracket integrally cast with the crankcase. The same arrangement may also be used for outboard marine drives.  
           [0007]    Thus, the generator mounting arrangement having an adequate mechanical strength can be ensured in a highly compact manner without increasing the cost and weight. Typically, at least two brackets are integrally cast with the crankcase, one being provided with a pivot hole for pivotally supporting the generator, the other being provided with an arcuate slot for fixedly securing the generator at a desired angular position around the pivot hole.  
           [0008]    According to a particularly preferred embodiment of the present invention, a hollow ridge is integrally cast with the crankcase to define an oil gallery therein, and connected to the bracket. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    Now the present invention is described in the following with reference to the appended drawings, in which:  
         [0010]    [0010]FIG. 1 is a side view of an outboard marine drive equipped with a V-type vertical engine embodying the present invention;  
         [0011]    [0011]FIG. 2 is a plan view showing an essential part of the V-type vertical engine shown in FIG. 1;  
         [0012]    [0012]FIG. 3 is a bottom view showing the crankcase of the V-type vertical engine shown in FIG. 1;  
         [0013]    [0013]FIG. 4 is a sectional view taken along line IV-IV of FIG. 3; and  
         [0014]    [0014]FIG. 5 is a perspective view showing the mode of hoisting the V-type vertical engine shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    [0015]FIGS. 1 and 2 show an outboard marine drive equipped with a V-type vertical engine  1  embodying the present invention. This engine  1  consists of a V-type six-cylinder engine, and comprises a V-shaped cylinder block  2  having a pair of cylinder banks, a crankcase  5 , and a pair of cylinder heads  3  and  4 . The engine  1  is covered by a cowling  16 . The lower end of the engine  1  is connected to a propulsion unit  9  including a gear housing  6 , a screw  8  and an extension case  7  accommodating a power train leading to the screw  8 .  
         [0016]    To the upper end of a crankshaft  10  is connected a camshaft drive pulley  11 , and to the upper end of a camshaft (not shown in the drawing) provided in each cylinder head is connected a camshaft driven pulley  12 ,  13 . A timing belt  14  is passed around the camshaft drive pulley  11  and camshaft driven pulleys  12  and  13 , and is guided and appropriately tensioned by three idle pulleys  15  including a tension pulley.  
         [0017]    To the upper end of the crankshaft  10  is fixedly attached an ACG drive pulley  17 , and an ACG drive endless belt  20  is passed around the ACG drive pulley  17  and an ACG driven pulley  19  attached to an input shaft of an ACG  18  fixedly attached to the crankcase  5 .  
         [0018]    The inner sides of the cylinder heads  3  and  4  opposing each other support a common intake device  22  via an intake manifold  21  attached to each cylinder head  3 ,  4 . The outer sides of the cylinder heads  3  and  4  are provided with exhaust manifolds  23 , respectively. On one side of the cylinder block  2  is mounted a starter motor  24 .  
         [0019]    As best shown in FIG. 5, brackets  30 ,  31  and  32  are integrally cast on the outer surface of the crankcase  5  to attach the ACG  18 , and project laterally outward. In this embodiment, these brackets  30 ,  31  and  32  project outwardly without any overhang so that the mold elements may be removed laterally without any problem when casting the crankcase  5 . The first and second brackets  30  and  31  are formed with mounting holes  33  and  34  which align vertically to each other so that the ACG  18  may be pivotally supported around a vertical axial line by passing a threaded bolt  36  through these holes  33  and  34  and a corresponding mounting hole of the ACG  18 . The third bracket  32  laterally opposes the other brackets  30  and  31 , and is provided with an arcuate slot  35  corresponding to the rotational trajectory of the ACG  18 . A threaded bolt  37  is passed through a mounting hole of the ACG  18  and slot  35 , and after turning the ACG  18  around the threaded bolt  36  so as to apply a desired tension to the ACG drive endless belt  29 , the threaded bolt  37  is fastened to fixedly secure the ACG  18  at this position.  
         [0020]    In this embodiment, the three hanger brackets  37 ,  38  and  39  are attached to the outer sides of the cylinder heads  3  and  5  and an upper central part of the outer surface of the crankcase  5  by using threaded bolts. Therefore, these threaded bolts can be fastened from sideways, and this reduces the possibility of interferences from other component parts. The cylinder heads  3  and  4  have a large wall thickness, and have an adequate mechanical strength to hoist the engine. As for the crankcase  5 , the hanger bracket  39  is secured to a base of the first ACG mounting bracket  30  which may be given with a desired wall thickness. In particular, by using three points for hoisting the engine as shown in FIG. 5, the hanger brackets can be secured to the parts of the engine which are relatively peripheral to the engine and relatively free from the interferences from other components, and the engine may be hoisted in a stable manner.  
         [0021]    As shown in FIGS. 3 and 4, in such a vertical engine, an oil gallery is provided in the crankcase  5  to feed the engine oil drawn by an oil pump  45  from an oil sump  46  provided in a lower part of the engine to the crankshaft and camshaft via a passage provided in the upper end of the cylinder block  2 . In this embodiment, on the outer surface of the crankcase  5  extend a first ridge  40  between the first and second brackets  30  and  31 , and a second ridge  42  between the second bracket  31  and gear housing  6  via an annular boss  41  for mounting an oil filter  44 , both in the vertical direction. As best shown in FIG. 4, these ridges  40  and  42  internally define a passage  43  serving as an oil gallery.  
         [0022]    Such a relatively large outboard marine engine equipped with a starter motor is required to have an ACG having a corresponding large output capacity, and needs a structure having a mechanical strength that is required for mounting a relatively large and heavy ACG. Therefore, conventionally, relatively large steel brackets were mounted on the upper surface of the crankcase to support a relatively large and heavy ACG. However, it was sometimes difficult to secure a necessary mounting surface, and the number of components and the amount of the assembly work were unacceptably great. The present invention eliminates such a problem by using ACG mount brackets integrally cast with the crankcase. To ensure a sufficient mechanical strength even when the crankcase has a relatively thin wall, ridges  40  and  42  extend substantially over the entire length of the crankcase and connect the first and second brackets  30  and  31  to each other. Furthermore, these ridges also contribute to a compact design of the engine as they are used for defining a passage  43  serving as an oil gallery.  
         [0023]    Thus, the present invention provides a generator mounting structure having an adequate mechanical strength which is both compact and light in weight at low cost. In particular, if a hollow ridge is integrally cast with the crankcase to define an oil gallery therein, and connected to the bracket, an even more compact and light-weight design becomes possible.  
         [0024]    Although the present invention has been described in terms of a preferred embodiment thereof, it is obvious to a person skilled in the art that various alterations and modifications are possible without departing from the scope of the present invention which is set forth in the appended claims.