Patent Publication Number: US-2015083061-A1

Title: Cam phaser with eccentric lantern gear component

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to foreign German patent application No. DE  102013015844 . 3 , filed on Sep.  24 ,  2013 , the disclosure of which is incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a cam phaser transmission device adjustable in the angle of rotation with a drive gear and an output gear, where the drive gear and the output gear are arranged coaxial relative to the axis of rotation of the transmission device, and with a transmitter element revolving eccentrically about the axis of rotation and an actuating device, where the actuating device comprises an eccentric portion acting upon the transmitter element. 
     BACKGROUND 
     Conventional planetary gear mechanisms are used in the art as single or multi-stage gears for very different applications. In this, the planetary gear mechanisms can be designed as a toothed gear mechanism or a friction gear mechanism and can, in addition to axes fixed to the frame not changing their position in the gear housing, also comprise revolving axes revolving in circular orbits in the gear mechanism. In addition to the transmission of a rotational motion, addition and distribution gears are with a planetary gear mechanism easily realized. Since planetary gear mechanisms always have at least two shafts fixed to the frame and one revolving shaft, at least one two-stage gear transmission is always given with an overall relatively high transmission ratio in contrast to simple single-stage stationary gear mechanisms. With arranging an outer ring gear and an inner sun gear in one plane, a particularly short planetary gear mechanism can be realized. 
     The possibility of a planetary gear mechanism in a three-shaft operation using two shafts for driving the gear mechanism and always using one shaft for the output enables a large range of different applications, for example, for driving hybrid vehicles. Transmission devices adjustable in the angle of rotation that are used as cam phasers for increasing performance and fuel economy in modern internal combustion engines are usually designed as single-stage or multi-stage planetary gear mechanisms. In this, a second drive shaft controls adjustment of the angle of rotation between the first drive shaft and the output shaft. 
     Cam phasers provide adjustment of valve opening times to the load behavior of the engine during operation of internal combustion engines. The adjustment of overlap times of the exhaust valves and intake valves allows not only for fuel savings as well as power and torque gains but also for reduction in emissions, which is important in view of the ever-increasing requirement to comply with emission standards. 
     In addition to planetary gear mechanisms, a whole number of different designs and concepts for transmission devices that are adjustable in the angle of rotation are used as cam phasers. Most widely spread are nowadays hydraulic cam phasers that are based on a swing motor known from hydraulic technology and equipped with several vanes to increase the transmittable torque. Hydraulic cam phasers are in the internal combustion engine driven via the engine oil circuit, which is why operation of the cam phaser depends on the pressure and the temperature of the engine oil, and therefore on the operating temperature and the rotational speed of the internal combustion engine. 
     In addition, electric cam phasers are known that operate independently of oil pressure. Due to the electric actuation of the cam phaser, they can also be adjusted in an internal combustion engine that is not operational and additional hydraulic pumps can be avoided in the engine oil circuit. DE 41 10 195 A1 describes an electric cam phaser in which an electric motor effects relative adjustment of the angle of rotation of the camshaft relative to the camshaft gear. Either a threaded portion with a spline or a planetary gear with a self-locking transmission ratio is used as an actuating mechanism. EP 573 019 B1 further describes a parallel planetary gear mechanism with internally toothed gear wheels in which several eccentric elements driven by a shaft eccentrically rotate a plurality of gear wheels with external toothing and in sections make them engage with the internal toothing of the ring gears. 
     The cam phaser or transmission devices adjustable in the angle of rotation known in prior art entail various problems depending on the design and embodiment. Whereas hydraulic swing motors are in a negative manner dependent upon the pressure and temperature of the engine oil, the respective cam phasers with electric actuation have drawbacks in terms of actuating speed, the required actuating energy, self-locking or of running smoothly, in particular, when being embodied as eccentric gear mechanisms. 
     Although the designs and concepts for cam phasing known in the art have overall proven themselves for the use in modern internal combustion engines, there are continuous efforts to realize optimized designs, especially with regard to the large quantities common in the automotive industry, and to eliminate or minimize existing problems. In view of the ongoing innovative activity to increase efficiency of internal combustion engines, there is furthermore generally the necessity to describe new solutions to replace employed designs with optimized or inexpensive concepts. 
     SUMMARY OF THE INVENTION 
     The present invention is therefore based on the object to provide a cam phaser transmission device adjustable in the angle of rotation to improve problems of transmission devices known in prior art with relative adjustment of two drive components and to enable high positioning accuracy and operational reliability at the lowest possible production effort. 
     This object is solved in that the transmitter element is formed as a lantern element, where the lantern element comprises a transmitter disk being disposed eccentric to the axis of rotation and having a plurality of pins that protrude concentric to the transmitter disk on a first face side of the transmitter disk, where the lantern element partly engages with the drive gear and partly engages with the output gear, and where the lantern element is by the eccentric portion movable via the transmitter disk eccentrically about the axis of rotation in order to move the drive gear and the output gear relative to each other. With the use of lantern elements that on the side of the drive and output gears engage with suitable positive-fit elements, for example, lantern gears, gear wheels or corrugated bands, the use of precision-ground or braced gears can in transmission devices or gear mechanisms adjustable in the angle of rotation be dispensed with, whereby a major cost factor in the manufacture of power-split gear mechanisms can be saved. In this, suitable lantern elements are generally composed of at least one disk on which a plurality of pins are provided with regular spacing concentric to the center of the disk and are welded or riveted into associated bores on the disk or otherwise attached and protrude perpendicular relative to the respective face side, i.e. in an axially parallel manner to the disk axis. In the redirection of forces of the lantern element onto the drive gear and the output gear, the pins are essentially subjected to shear stress, so that the wear of the toothing of gear components otherwise occurring can be reduced. 
     In conventional use, lantern elements are used for slow drive elements in high-contamination environments, such as in mining, where high contamination must not lead to malfunction of a drive. In addition to the limitation to relatively only low drive speeds, lantern elements can there also transmit only relatively small forces, as the associated lantern gears are in conventional applications strongly rounded at the base circle and the base of the tooth is thereby weakened. In contrast to the conventional application of lantern elements, the transmission device according to the invention uses lantern elements for both high speeds as well as for relatively high forces. 
     While transmission devices adjustable in the angle of rotation common today are in the range of high transmission ratios, in particular as cam phasers in internal combustion engines, primarily implemented by using multi-stage planetary gears of which the power take-off is provided with a corresponding high-revving motor, the solution according to the invention enables a single or multiple stage transmission device which due to the integrative co-action of three rotating components and an actuating device enables a direct very high reduction ratio despite requiring a small installation space. This design according to the invention is not a mere compilation of partially optimized components, but rather an integral, customized, complex design of an intelligent system for power transmission. 
     The key element of this transmission device adjustable in the angle of rotation according to the invention is there the transmitter element formed as a lantern element which in sections engages with the drive gear and in sections with the output gear and is positioned eccentric relative to the axis of rotation. The lantern element, due to its special design as an embedded rigid non-elastic wobble body, there enables a power increase when engaged with the drive gear and the output gear in a kind of wedge effect. Due to the eccentric arrangement of the circular transmitter disk, a flat cylindrical disk with a concentric recess, the radius of which is by a multiple larger than its thickness and the main axis of which is offset in an axially parallel manner relative to the axis of rotation of the transmission device, a wobbling motion of the transmitter disk occurs during actuation of the transmitter element by the eccentric portion of the actuating device together with a change in the axis position of the disk which rotates with the eccentricity c about the axis of rotation. 
     While the wobbling transmitter disk and the pins protruding relative to a first face side perform a radial motion relative to the axis of rotation, a tangentially acting force results at the drive gear and the output gear leading to a relative motion. The design of the drive gear, the output gear and the transmitter element is there coordinated such that the circular transmitter disk performs an off-center wobbling circular motion with the eccentricity ε relative to the axis of rotation. With the design according to the invention on the basis of an eccentrically rotating, wobbling lantern element, large reduction ratios can be achieved depending on the design and arrangement of the elements. In the main use case of application of transmission devices adjustable in the angle of rotation, the use as a cam phaser, a respective high reduction enables the use of small-sized actuators and low backlash to the actuator by the self-locking of the high transmission ratio. 
     A preferred embodiment provides that the transmitter disk also comprises a plurality of pins on the second face side which are arranged concentric and protrude relative to the second face side. In contrast to a one-sided engagement of the drive or output gear on the inner and outer side of the ring of pins, the ring-shaped arrangement of pins on both face sides of the transmitter disk enables independent engagement of the drive and the output gear with freely selectable transmission ratios. It is there advantageous if the pins protruding concentrically relative to the first face side and the pins protruding concentrically relative to the second face side of the transmitter disk are arranged on different radii of the transmitter disk. The different radii of the concentrically disposed rings of pins, i.e. the different distance between the center of the transmitter disk and the circular line of the pins disposed in a ring-shaped manner increases the freedom of design for drive and output gears being in engagement with this lantern element. For different transmission ratios, the number of pins protruding concentrically relative to the first face side and the number of pins protruding concentrically relative to the second face side can there differ. The different number of pins equally spaced at the circumference on a circular line enables different transmission ratios irrespective of the design of the drive gear and the output gear. The pins protruding concentrically relative to the first and respectively second face side of the transmitter disk wobble together with the transmitter disk relative to the axis of rotation of the transmission device, so that they engage only in sections with the drive gear and the output gear. 
     An advantageous embodiment provides that the number of pins protruding concentrically relative to the first face side and/or the number of pins protruding concentrically relative to the second face side is as large as possible, for example, is greater than 50. With a large number of pins protruding relative to a planar side, high transmission ratios can be achieved already with a single-stage transmission device, i.e. a high reduction of the power take-off via the actuating device. The number of positive-fit elements on the drive gear and on the output gear preferably differs by 2, in particular by 1, from the number of protruding pins, i.e. is only slightly greater than or less than the number of pins. 
     The drive gear and the output gear can advantageously comprise lantern gears that engage in sections with the lantern element. Unlike milled or ground gears that require high-precision manufacturing in particular for planetary gear mechanisms, lantern gears can be produced by simple punching. To realize the thinnest possible transmission device, the drive gear and the output gear can there externally toothed lantern gears that use the inner ring space of the one ring of pins protruding from at least one face side of the transmitter disk, where the drive gear and the output gear each engage in sections on one face side with the protruding pins. Alternatively, the drive gear and the output gear can be configured as ring gears and with an internal toothing engaging from the outside with the lantern element. The teeth of the lantern gear can in an advantageous modification be designed as being flat in order to avoid weakening the base of the tooth. Such flat teeth, receiving only about half or slightly more than half of the pins, allow high speeds during engagement of the lantern elements with the lantern gears. 
     A special design of the transmission device adjustable in the angle of rotation provides that the transmission device is designed as a two-stage gear, the two-stage gear comprises a first and a second lantern element disposed eccentric relative to the axis of rotation and a transition element which in sections engages with the first lantern element and in sections with the second lantern element, where the drive gear in sections engages with the first lantern element and the output gear in sections engages with the second lantern element. The configuration of the transmission device as a two-stage gear allows a very high reduction ratio and very good self-locking. Depending on the manner in which the drive gear and the output gear engage with the first and the second lantern element, the configuration as a two-stage gear allows for a change of the sign of the transmission, so that there can be a subtraction of transmission rations slightly differing from each other, whereby extremely large transmission rations can be realized. 
     In an inverted configuration of the invention, the drive gear and the output gear are formed as lantern elements having a plurality of pins arranged concentric relative to the axis of rotation, and the transmitter element is formed as a lantern gear, where the lantern gear comprises a transmitter disk disposed eccentric relative to the axis of rotation with a first and a second lantern toothing which are arranged concentric to the transmitter disk, where the lantern elements of the drive gear and the output gear each in sections engage with the first and the second lantern toothing of the transmitter disk and where the transmitter disk is eccentrically movable about the axis of rotation by the eccentric portion in order to move the drive gear and the output gear relative to each other The transmitter element can there comprises two lantern gears of different circumference connected to each other in a rotationally-fixed manner eccentric to the axis of rotation which by the eccentric portion of the actuating device engage with the pins, being arranged concentric relative to the axis of rotation, of the lantern elements of the drive gear and the output gear. The basic mode of operation of this inverted configuration of a transmission device adjustable in the angle of rotation does not differ from the embodiment described above having an eccentrically revolving lantern element, for which reason reference is respectively presently made to the advantages of the invention already described above. 
     A main embodiment provides that the actuating device comprises a power take-off shaft on which auxiliary shaft the eccentric portion is arranged and which is coupled to an actuating drive, preferably to an electric motor. Such a power take-off shaft not only enables simple coupling of an actuator and thereby a simple drive but also simple formation of the circular eccentric portion. For an advantageous configuration, bearing seats can be provided on the power take-off shaft on which the drive gear and the output gear are mounted. This eliminates the need for any further mounting of the transmission device and a counter bearing by the output shaft associated with the output gear, for the cam phaser, the associated camshaft. 
     For operating the adjustment of the angle of rotation as smooth as possible via the actuating device, a bearing seat can be provided on the eccentric portion on which the eccentrically revolving transmitter disk is mounted. In addition to simple ball bearings, roller bearings or sliding bearings can also be provided between the transmitter disk wobbling about the axis of rotation and the circular eccentric portion disposed eccentric relative to the axis of rotation. 
     The present invention also relates to a cam phaser for an internal combustion engine with a transmission device adjustable in the angle of rotation, where the drive gear is by a timing assembly (timing chain) coupled at a fixed angle of rotation to the crankshaft and the output gear to a camshaft. Such a cam phaser, despite the use of simple components, enables reliable adjustment of the angle of rotation of the camshaft relative to the camshaft gear of an internal combustion engine with a large reduction ratio and good self-locking. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the transmission device adjustable in the angle of rotation shall below be explained with reference to drawings. In the drawings: 
         FIG. 1  shows a cross-sectional view of a transmission device adjustable in the angle of rotation according to the invention, in particular for a cam phaser of an internal combustion engine; 
         FIG. 2  shows a side view of the transmission device of  FIG. 1  from the direction of the power take-off shaft; 
         FIG. 3  shows perspective side view of the transmission device of  FIG. 1 ; 
         FIG. 4  shows a partially cut-away perspective side view of the transmission device of  FIG. 3 ; and 
         FIG. 5  shows a schematic view of a cam phaser according to the invention with the transmission device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The sectional view in  FIG. 1  shows an embodiment of a transmission device  1  adjustable in the angle of rotation according to the invention with an axis of rotation D that can be used as a cam phaser  24  in an internal combustion engine. The transmission device  1  shown in this sectional view comprises a power take-off shaft  2  of a actuating device  6  positioned along the axis of rotation D, and a drive gear  3  and a output gear  4  which are rotatably mounted on the power take-off shaft  2 , as well as a transmitter element  5  enabling engagement in sections with the drive gear  3  and the output gear  4 . The power take-off shaft  2  comprises a drive bearing seat  7  and an output bearing seat  8  which are each provided with a double ball bearing  9  on which in turn the drive gear  3  and the output gear  4  are positioned coaxial to the axis of rotation D and mounted rotatably relative to the power take-off shaft  2 . An eccentric portion  10  is provided on the power take-off shaft  2  between the drive bearing seat  7  and the output bearing seat  8 . The eccentric portion  10  having a circular configuration comprises an eccentric axis E which is concentric relative to the eccentric portion  10 , but at the same time is arranged offset from the axis of rotation D of the power take-off shaft  2  by the eccentricity e. With each rotational motion of the power take-off shaft  2 , the position of the axis E relative to the axis of rotation D therefore changes, so that the eccentric axis E of the circular eccentric portion  10  wobbles with every rotational motion of the power take-off shaft  2  with the eccentricity £ about the axis of rotation D. Provided on the circumference of the circular eccentric portion  10  is an eccentric bearing seat  11  on which a ball bearing  12  is arranged, on which the transmitter disk  13  of the transmitter element  5  is rotatably supported relative to the eccentric portion  10 . Also the circular bending-resistant transmitter disk  13  therefore wobbles together with the eccentric portion  10  with the eccentricity £ about the axis of rotation D. 
     A plurality of pins is provided respectively on the first face side  14  and the second face side  15  of the transmitter disk  13  and arranged concentric to the eccentric axis E with equal spacing on a circular path. The pins  16  extend through respective bores  17  on the transmitter disk  13  in which the pins are fixedly anchored using known joining methods of chain technology, for example rivets. The fixed joining of the pins  16  in the bores  17  of the transmitter disk  13  enables the production of a stable and highly accurate lantern element  20 , i.e. the revolving transmitter element can in the transmission device  1  according to the invention adjustable in the angle of rotation also be used during higher speeds and higher transmission of forces. Alternatively, the pins  16  can also be disposed in the circumferential surface of the transmitter disk  13  and protrude relative to a face side  14 ,  15 . 
     The drive gear  3  is on the side facing the transmitter disk  13  provided with a lantern gear  18  which is arranged in the inner space formed by the pins  16  protruding form the first face side  14  of the transmitter disk  13  and in sections engages with the pins  16  protruding at the first face side  14 . Also on the side of the output gear  4  facing the transmitter disk  13 , a lantern gear  19  is provided which is arranged in the inner space formed by the pins  16  protruding on the second face side  15  of the transmitter disk  13  and in sections engages with the pins  16  protruding on the second face side  15 . 
     Due to the eccentricity e of the transmitter disk  13  relative to the axis of rotation D, the pins  16  protruding on the first face side  14  and the second face side  15  each only in sections completely engage with the lantern gears  18  and  19 , respectively, of the drive gear  3  and the output gear  4 , which can be seen in  FIG. 1  in the lower part of the image. On the opposite side on which the eccentric axis E is offset by the eccentricity e relative to the axis of rotation D, a gap S exists between the pins  16  of the lantern element  20  and the lantern gears  18 ,  19  of the drive gear  3  and the output gear  4 . The spacing there between the pins  16  and the lantern gears  18 ,  19  is in the gap S approximately twice as large as the eccentricity e. 
     The double ball bearing  9  positioned on the drive bearing seat  7  is in the side view of the transmission device  1  in  FIG. 2  visible in addition to the power take-off shaft  2  protruding relative to the drive  3  as well as the shaft stub  21  of the power take-off shaft  2  for attaching an actuator, e.g. an electric motor  28 , for driving the actuating device  6 . The drive gear  3  on the outer side facing away from the lantern gear  18  further comprises a circumferential annular groove  22 ,  26  which enables secure attachment of a camshaft gear wheel  26  on the drive gear  3 . A circumferential annular groove  23  is similarly provided on the outer side of the output gear  4  facilitating the attachment on a camshaft  25 . 
       FIGS. 3  shows a perspective side view of the transmission device  1  according to the invention from the side of the output gear  4  in which the circumferential groove  23  for connecting the camshaft  25  is easily recognizable. The power take-off shaft  2  mounted in the output gear  4  by the double ball bearing  8  is further visible in the center of the output gear  4 . The transmitter disk  13  revolving in a wobbling manner relative to the axis of rotation D is arranged between the output gear  4  and the drive gear  3  arranged on the side facing away. On the side of the transmitter disk  13  facing the drive gear  3 , a plurality of equidistant bores  17  arranged concentric relative to the eccentric axis E are visible in which the pins  16  protruding on the first face side  14  are attached. The pins protruding on the second face side  15  of the transmitter disk  13  are in the perspective view of  FIG. 3  hidden behind the output gear  4 . The pins  16  protruding on the first face side of the transmitter disk  13  in sections engage with the lantern gear  18  of the output gear  3  which is disposed within the circle of pins on the first face side  14 . 
     The perspective side view in  FIG. 4 , like  FIG. 3 , shows the transmission device  1  according to the invention from the side of the output gear  4 , the drive gear  3  and output gear  4 , however, are omitted in this view so that essentially only the transmitter element  5  with the actuating device  6  is shown. This representation very nicely shows the arrangement of the pins  16  on the second face side  15  of the transmitter disk  13  which protrude the same distance on a concentric circle relative to the axis E of the second face side  15 . The pins  16  also on the first face side  14  of the transmitter disk  13  protrude perpendicular to the transmitter disk  13  and axially parallel to the axis of rotation D on the first face side  14 . Accordingly, this lantern element  20  of a transmission device  1  according to the invention on the first and the second face sides  14 ,  15  comprises the pins  16  for engagement with the associated lantern gears  18 ,  19 . 
       FIG. 5  shows a partially cut-away schematic side view of a cam phaser  24  according to the invention for an internal combustion engine based on a transmission device  1  adjustable in the angle of rotation. The transmission device  1  is with the ring flange formed by the double ball bearing  9  seated in a hollow cylindrical end of a camshaft  25  of the internal combustion engine, where the hollow cylindrical seat of the camshaft  25  protrudes up into the groove  23  of the output gear  4 . The camshaft  25  therefore revolves together with the output gear  4  about the axis of rotation D. On the outer circumference of the drive gear  3 , a camshaft gear  26  is arranged seated on the ring flange the drive gear  3  around the double ball bearing  9  and protrudes into the groove  22  at the outer side of the drive gear  3 . The camshaft gear wheel  26  connected via a timing chain  27  is in rotational angle-fixed manner to the crankshaft (not shown) of the internal combustion engine, i.e. coupled in a crankshaft-fixed manner. An electric motor  28  is provided on the power take-off shaft  2  of the actuating device  6  for adjusting the rotational angle position between the drive gear  3  and the output gear  4  of the transmission device  1 , respectively between the crankshaft-fixed camshaft gear wheel  26  and the camshaft  25  of the internal combustion engine. This electric motor  28  can there co-rotate with the rotational motion of the main drive via the camshaft gear wheel  26 , so that the relative rotational motion of the main drive is merely accelerated or decelerated by the electric motor  28  to achieve a desired adjustment of the angle of rotation. 
     In an alternative inverted embodiment, the drive gear  3  and the output gear  4  are configured as lantern elements  20  comprising a plurality of pins  16  arranged concentric relative to the axis of rotation D, where the transmitter disk  13  arranged eccentric relative to the axis of rotation D comprises a first and a second lantern toothing being arranged concentric to the transmitter disk  13 . The lantern elements  20  of the drive gear  3  and the output gear  4  each in sections engage with the first and the second lantern toothing of the transmitter disk  13  in order to move the drive gear  3  and the output gear  4  relative to each other. The transmitter element  5  can there comprise two lantern gears of different circumference connected to each other in a rotationally-fixed manner eccentric to the axis of rotation D which by the eccentric portion  10  of the actuating device  6  engage with the pins  16 , being arranged concentric to the axis of rotation D, of the lantern elements  20  of the drive gear  3  and the output gear  4 . The basic mode of operation of this inverted configuration of a transmission device adjustable in the angle of rotation does not differ from the transmission device  1  illustrated in  FIGS. 1 through 5  with an eccentrically revolving lantern element  20 . 
     The function and the mode of operation of a transmission device  1  adjustable in the angle of rotation, or respectively a cam phaser  24 , are illustrated in detail below. 
     For transmission of a rotational motion of a main drive, for example the motion of a crankshaft (not shown) of an internal combustion engine, the camshaft gear wheel  26  and the drive gear  3  fixedly connected thereto is during operation by use of the transmission device  1  via the lantern element  20  in sections being in engagement with the drive gear  3  and the output gear  4  coupled to the output gear  4  and from there connected to the camshaft  25 . 
     As clearly visible in  FIG. 1 , simultaneous engagement in sections of the pins  16  protruding at the first and the second face sides  14 ,  15  of the transmitter disk  13  with the lantern gear  18  of the drive gear  3  and the lantern gear  19  of the output gear  4  enables direct transmission of the rotary motion of the main drive of the drive gear  3  to the output gear  4 . 
     For adjustment of the angle of rotation between the drive gear  3  and the output gear  4 , when used as a cam phaser  24 , respectively the adjustment of the angle of rotation between the camshaft gear wheel  26  attached between the drive gear  3  and the camshaft  25  arranged on the output gear  4 , an additional rotational motion is via the power take-off shaft  2  forced upon the lantern element  20  by the eccentric portion  10 . For this purpose, a suitable drive is attached to the power take-off shaft  2 , commonly a traveling electric motor  28 . 
     The transmitter disk  13  of the lantern element  20  mounted eccentric relative to the gear axis D on a ball bearing  12  is via the rotational motion of the circular eccentric portion  10  being eccentric relative to the axis of rotation D of the power take-off shaft  2  also activated to perform a wobbling motion about the gear axis of rotation D. 
     The ball bearing  12  positioned between the eccentric portion  10  and the transmitter disk  13  on the eccentric bearing seat  11  there allows a low-friction relative motion between the lantern element  20  and the eccentric portion  10 . The eccentrically arranged region of the circular eccentric portion  10  via the ball bearing  12  presses the transmitter disk  13  or the pins  16  protruding at the first and the second face side  14 ,  15 , respectively, into the toothing of the lantern gears  18 ,  19  of the drive gear  3  and the output gear  4 , so that, with a revolution of the eccentric portion  10 , the lantern element  20  rolls over the entire circumference on the lantern gears  18  and  19 . In this, the drive gear  3  and the output gear  4  move relative to the lantern element  20  each offset by the difference between the number of pins  16  on the first and the second face side  14 ,  15  of the transmitter disk  13  and the number of the tooth gaps of the associated lantern gears  18 ,  19 . While on the one side, see Fig. below  1 , the pins  16  protruding from the first and the second face side  14 ,  15  are in engagement with the associated lantern gears  18 ,  19  of the drive gear  3  or the output gear  4 , respectively, a gap S amounting to approximately twice the eccentricity e arises between the pin  16  and the Lantern gears  18 ,  19  on the opposite side of the transmitter disk  13  being spaced by the eccentricity e from the axis of rotation D. Gap S prevents overlap of the pins  16  with the protruding teeth of the lantern gears  18 ,  19 , thereby allowing eccentric revolution of the lantern element  20  between the drive gear  3  and the output gear  4 . 
     When adjusting the angle of rotation between the drive gear  3  and the output gear  4  of the transmission device  1 , respectively adjustment of the angle of rotation between the camshaft gear wheel  26  and the camshaft  25  of the cam phaser  24 , the co-rotating rotor of the electric motor  28 , in the event of use of a co-rotating electric motor  28 , arranged on the power take-off shaft  2  is accelerated or decelerated so that the position of the eccentric portion  10  and thereby of the transmitter disk  13  changes relative to the drive gear  3  and the output gear  4 . During mere transmission of the main drive to the drive gear  3 , i.e. during mere transmission of the rotational motion of the crankshaft-fixed camshaft gear wheel  26  to the camshaft  25  on the other hand, the relative position of the drive gear  3  and the output gear  4  relative to each other does not change. 
     When adjusting the angle between of rotation between the drive gear  3  and the output gear  4  of the transmission device  1 , respectively adjustment of the angle of rotation between the camshaft gear wheel  26  and the camshaft  25  of the cam phaser  24 , the co-rotating rotor of the electric motor  28 , in the event of use of a co-rotating electric motor  28 , arranged on the power take-off shaft  2  is accelerated or decelerated so that the position of the eccentric portion  10  and thereby of the transmitter disk  13  changes relative to the drive gear  3  and the output gear  4 . During mere transmission of the main drive to the drive gear  3 , i.e. during the mere transmission of the rotational motion of the crankshaft-fixed camshaft gear wheel  26  to the camshaft  25  on the other hand, the relative position of the drive gear  3  and the output gear  4  relative to each other does not change. During a motion of the transmitter disk  13 , the pins  16  of the lantern element  20  roll around the lantern gears  18 ,  19 , whereby the drive gear  3  and the output gear  4  move relative to each other. The reduction ratio of the lantern element  20  from the lantern gear  18  of the drive gear  3  to the lantern gear  19  of the output gear  4  results from the different rolling distance of the lantern element  20  on the lantern gear  18  as compared to the lantern gear  19 . 
     The transmission device  1  according to the invention shown in the embodiments in  FIGS. 1 through 5  comprises, for example,  60  pins  16  on the eccentrically revolving lantern element  20  on the first face side  14 , and slightly less on the second face side  15 , namely 56 pins  16 . The lantern gears  18 ,  19  associated with these rows of pins  16  and disposed in the inner spaces formed by the pins arranged in a circular manner concentric relative to the eccentric axis E comprise a number of teeth which is each smaller by 1. For the partial transmission ratio between the drive gear  3  and the lantern element  20  as well as between the output gear  4  and the lantern element  20 , transmission ratios therefore arise of about 1:60 and 1:56, so that an overall transmission ratio of about 1:820 results. Compared to this subtractive interconnection of these two partial transmission ratios, an overall transmission ratio of approximately 1;30 would be obtained with only one ring of pins on the front side during engagement of one of the lantern gears  18  or  19  as a ring gear from the outside and one from the inside with the lantern element  20 . Accordingly, gear mechanisms with very high reduction ratios can be realized with the transmission device  1  according to the invention. 
     LIST OF REFERENCE NUMERALS 
     
         
           1 : transmission device 
           2 : power take-off shaft 
           3 : drive shaft 
           4 : output shaft 
           5 : transmitter element 
           6 : actuating device 
           7 : drive bearing seat 
           8 : output bearing seat 
           9 : double ball bearing 
           10 : eccentric portion 
           11 : eccentric bearing seat 
           12 : ball bearing 
           13 : transmitter disk 
           14 : first face side 
           15 : second face side 
           16 : pins 
           17 : bores 
           18 : lantern gear 
           19 : lantern gear 
           20 : lantern element 
           21 : shaft stub 
           22 : groove 
           23 : groove 
           24 : cam phaser 
           25 : camshaft 
           26 : camshaft gear wheel 
           27 : timing chain 
           28 : electric motor 
       
    
     D: axis of rotation
     E: eccentric axis   S: gape   ε: eccentricity