Abstract:
An engine suitable for a motor vehicle, preferably a motorcycle, and a related transmission is provided. The transmission is provided with a hydrostatic device and a planetary transmission leading to a driven shaft. In order to optimize the engine with regard to construction and function the hydrostatic device of the transmission cooperating with the internal combustion engine is in an effective connection to the planetary transmission.

Description:
[0001]    This application claims the priority of Austrian Patent Document A 1785/2006, filed Oct. 24, 2006, the disclosure of which is expressly incorporated by reference herein. 
       BACKGROUND AND SUMMARY OF THE INVENTION 
       [0002]    The invention relates to an engine for a motor vehicle and related transmission. 
         [0003]    A motorcycle with a hydrostatic, constantly variable transmission is known from German Patent Document DE 39 04 045 C2, which comprises a swash plate hydraulic pump. The crankshaft of an internal combustion engine providing the drive for the motorcycle and the transmission are located in a common housing. The transmission has an input shaft and an output shaft arranged parallel in reference to the crankshaft. The crankshaft drives the input shaft via a primary rotation gear reduction, while the output shaft influences a rear wheel of the motorcycle with a secondary rotation gear reduction being interposed. 
         [0004]    From German Patent Document DE 101 26 105 A1 an engine for a motorcycle is disclosed, which engine being provided with a motor unit and a transmission unit. In the transmission unit an input shaft and an output shaft are supported rotationally in a frontal and/or rear area of another housing, different from the housing of the motor block, in order to form a transmission device. 
         [0005]    In German Patent Document DE 101 00 562 A1 a drive unit for a small vehicle is discussed, in which the drive unit and the transmission unit, coupled thereto in a pivotal manner, are installed. The drive unit is divided into three sections, namely a motor block, a transmission part, and a differential part. The transmission part is located in a transmission housing, in which a V-belt automatic transmission (rotation or speed regulation transmission) is arranged. 
         [0006]    The object of the invention is to provide an engine for a motor vehicle, preferably a motorcycle, which is characterized in a good function while having a simple design. 
         [0007]    The advantages primarily achieved by the invention are to be considered the excellent conditions for operating a motorcycle with said engine by the combination of the hydrostatic device and the planetary transmission connected to the internal combustion engine. Here, both the hydrostatic device and the planetary transmission represent technical systems, which can be further developed with the technical performance targeted for the intended use. This also applies to the spur gearing between the internal combustion engine and the hydrostatic device as well as the hydraulic pump and hydraulic motor components of said hydrostatic device. The exemplary function of the engine is additionally supported by the clutch and the brake and/or a suitable other fixing arrangement for the hollow wheel of the planetary transmission. Furthermore the engine is therefore well thought through, because based on the described components and/or their skilled cooperation a separate reverse gearing device can be omitted. Finally the disclosed method for operating the motorcycle sets new standards in the design of motor vehicles. 
         [0008]    Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The drawing, comprising a single FIGURE, illustrates a schematic power plant for a motorcycle, which is explained in greater detail in the following. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    An engine  1  for a motorcycle, not shown, of a one-track or multi-track and/or light or heavy type, including such embodiments which are mobile on road and off-road, comprises an internal combustion engine  2  and a transmission  3 . The transmission  3  leads to a drive shaft  4 , driven by one or more wheels of the motorcycle. The internal combustion engine  2  cooperates with a hydrostatic device  6 , with a power transmission unit embodied as a spur gearing  5  being interposed, which is in an effective connection to the planetary transmission  7  leading to the drive shaft  4 . 
         [0011]    The summarizing planetary transmission  7  is provided with a hollow wheel  8  and a sun wheel  9 . Between the hollow wheel  8  and the sun wheel  9  at least one planetary wheel  10  is effective, which is held by a planetary carrier  11  connected to the drive shaft  4 . The hydrostatic device  6  has a hydraulic pump  12  and a hydraulic motor  13 . In the hydraulic pump  12  an adjustment device  15  is integrated, provided with an adjustment ring  14  that can be deflected, by which the displacement volume of the hydraulic pump  12  can be modified. The hydraulic motor  13  is provided with a second adjustment device  16 , by which the volume of the intake of said hydraulic motor can be influenced. 
         [0012]    The spur gearing  5  comprises a first toothed wheel  17  and a second toothed wheel  18 , engaging the first toothed wheel  17  and cooperating with the hydraulic pump  12  with a first connection shaft  20  embodied as a hollow shaft  19  being interposed. Furthermore, between the first toothed wheel  17  and a crankshaft  21  of the internal combustion engine  2  an oscillation damper  22  is provided. The hydraulic motor  13  drives the sun wheel  9  of the planetary transmission  7  via a second connection crankshaft  23 . Here, the second connection shaft  23  is aligned coaxially in reference to the first connection shaft  20 , and the first connection shaft  20  surrounds the second connection shaft  23  at least partially. 
         [0013]    A clutch  24  is provided between the hollow shaft  20  and the hollow wheel  8 , preferably of the type of multi-disc friction coupling  25 . The latter is embodied as a power shift gear and provided with a basket  26  carrying friction discs and a hub  27  accepting friction discs. The clutch  24  and/or multi-disc friction coupling  25  is connected, on the one hand, to a first connection shaft  20  and, on the other hand, a cooperating hollow wheel  8  of the planetary transmission  7 . More precisely, the basket  26  is structurally united with the hollow wheel  8 ; the hub  27  with the first connection shaft  20 . For the rest, the hollow wheel  8  is provided with a brake  29  at its exterior  28 , which is supported at a fixed housing  30 . Instead of the brake  29 , a form-fitting connection e.g., a link may also be used to fix the hollow wheel  8 . 
         [0014]    In an operating internal combustion engine  2  the hollow shaft  20  rotates according to the transmission ratio in the spur gearing  5 . Here, when the motorcycle is stationary, the rotation of the drive shaft  4  is zero. The clutch  24  is open and the hydraulic pump  12  is driven via the hollow shaft  20 . By deflecting the adjustment ring  14  the hydraulic pump  12  is adjusted such that the hydraulic motor  13  and the sun wheel  9  connected to the latter rotate opposite in reference to the direction of rotation of the hollow shaft  19 . Here the drive shaft  4  is idling, because the hollow wheel  8  of the planetary transmission  7  transmits no torque. 
         [0015]    By closing the clutch  24  the hollow shaft  19  is connected to the hollow wheel  8  and the transmission of force is enabled. The start of the motorcycle occurs via a slipping clutch  24 . In order to ensure a targeted, soft acceleration the internal combustion engine  2  is operated with low rotations. After the coupling process is completed a continuous adjustment of the transmission ratio is possible by changing the displacement volume of the hydraulic pump  12 . The rotation of the sun wheel  9  is here reduced from a maximum rotation in the opposite direction in reference to the hollow wheel  8  to a rotation of zero and then is once more accelerated in the same direction of rotation as the hollow wheel  8  up to maximum rotation. This way, after the coupling process, a constant acceleration of the motorcycle can be achieved up to the maximum speed by changing the rotation of the sun wheel  9 . 
         [0016]    Thanks to the adjustable hydraulic motor  13  with the variable intake volume there is the additional chance to increase the entire range of the transmission even more. In a given displacement volume of the hydraulic pump  12  the rotation of the sun wheel  9  is increased by a reduction of the intake volume and the operational rotation is further increased. 
         [0017]    In case of critical driving conditions of the motorcycle the drive train can be interrupted by opening the clutch  24 . 
         [0018]    Motorcycles with the appropriate technical embodiment can also be moved backwards. This is achieved in the present embodiment such that the hollow wheel  8  of the planetary transmission  7  is blocked in reference to the housing  30 . Here, the sun wheel  9  is connected to the hydraulic motor  13 , with the sun wheel  9  being driven by changing the displacement volume at the hydraulic pump  12  such that the motorcycle can be driven forward and backward at low speeds. 
         [0019]    The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modification of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.