Patent Publication Number: US-2013239746-A1

Title: Centrifugal pendulum

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application PCT/DE2011/001908 filed Oct. 28, 2011 and claims priority from German Patent Application No. 10 2010 050 715.6 filed Nov. 8, 2010, which applications are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a centrifugal pendulum, especially a centrifugal pendulum for damping torsional oscillations of a drive train, for example, a drive train of a vehicle with a combustion engine. 
     BACKGROUND OF THE INVENTION 
     DE 198 31 160 Al discloses a speed-adaptive oscillation absorber for a shaft rotating around an axis. In this case, an inertial mass of the oscillation absorb executes a purely translational motion relative to the hub part. This is achieved by a mounting that is also referred to as a parallel bifilar suspension. Since the inertial mass is additionally a rigid element, each of the points assigned to the inertial mass executes an identical motion along a motion path B running through the respective point P. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an improved centrifugal pendulum. 
     The invention is a speed-adaptive centrifugal pendulum provided for a shaft rotating around an axis, having: a pendulum flange on which at least two axially opposite absorber masses connected to each other and at a distance from each other are mounted, whereby the absorber masses and/or the pendulum flange of the centrifugal pendulum has at least one cutout, in which the spacer element and thus the absorber mass is guided, whereby the cutout is formed, starting from a neutral position, by a circle or a curve deviating from a circular segment, by an increase in the radius of the cutout in one area starting from the neutral position, whereby the neutral position is the position in which the spacer element of the absorber mass contacts the cutout with an oscillation angle of the centrifugal pendulum of 0°. 
     The centrifugal pendulum has the advantage that, because the cutout is formed by a circle and/or a curve deviating from a circular segment, a sliding of a spacer element guided in the breakout, like a pin or a roller, can be counteracted and thus, sliding friction associated with it. 
     In one embodiment of the invention, the radius of the outer contour and/or inner contour of the breakout is designed so it is enlarged in at least one section and/or reduced in at least one section, whereby the radius of the outer contour and/or the inner contour is enlarged or reduced at one or both ends of the cutout. The outer contour and the inner contour of the cutout can have the same curve and/or contour curve or a different contour curve. 
     According to another embodiment of the invention, the radius of the outer contour and/or inner contour of the cutout is designed so it is enlarged or reduced in at least one section starting from a neutral position or point. 
     In another embodiment of the invention, the cutout is designed in such a way that the absorber mass can execute a translational or rotary motion, whereby the at least one cutout especially has a non-symmetrical curve or path curve. This means that the absorber mass does not follow a symmetrical path curve, but rather a non-symmetrical path curve as is shown in the following, e.g., in  FIGS. 2 and 4 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which: 
         FIG. 1  is a schematic representation of the principle of a centrifugal pendulum of the invention; 
         FIG. 2  is a first embodiment of the centrifugal pendulum of the invention; 
         FIG. 3  is a cross section view A-A of the centrifugal pendulum as shown in  FIG. 1 ; 
         FIG. 4  is a second embodiment of a centrifugal pendulum of the invention; 
         FIG. 5  is a cross section view A-A of the centrifugal pendulum as shown in  FIG. 4 ; 
         FIG. 6  is a roller cutout of a pendulum flange of the centrifugal pendulum of the invention as shown in  FIG. 4 ; and, 
         FIG. 7  is an assigned roller cutout of an absorber mass of the centrifugal force of the invention as shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects. 
     Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and, as such, may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
     The basic principle of a centrifugal pendulum is that an absorber mass pair is linked with a pendulum flange as a pendulum. Since the absorber mass pair is located in the centrifugal field, its natural frequency increases proportionally to the rotation speed. A design of the pendulum geometry makes it possible to always keep the natural frequency of the pendulum equal to an engine speed order. The term absorber order is used for this. The absorber order is q=√L/l, wherein l is the pendulum length or the radius of curvature of the pendulum running path in the fixed-shaft coordinate system and L is the distance from the center of curvature of this running path from the axis of rotation. The absorber order is determined on the basis of the engine speed orders k, depending on the number of engine cylinders. For example, for a 4-cylinder engine, q=2. 
       FIG. 1  shows a schematic illustration of the principle of a centrifugal force  10  of the invention. 
     The invention relates to a centrifugal pendulum for damping torsional oscillations of a drive train, especially a drive train in a vehicle, e.g., a vehicle with a combustion engine. However, the invention is not restricted to this application. 
     In this case, a centrifugal pendulum  10  is provided that has an absorber order curve that can be regulated in design depending on an oscillation angle. In addition, the centrifugal pendulum  10  simultaneously has an advantageous trapezoidal arrangement, i.e., the construction space can be used optimally. 
     The centrifugal pendulum  10  has a pendulum flange  12  and several absorber masses  14  arranged in pairs. The pendulum length, the pendulum spacing and the turning angle of the absorber masses are dependent on the oscillation angle, whereby an influence of the absorber arrangement (constant or changing) is possible. A turning angle of the absorber mass  14  is also provided. 
     This is achieved in that the geometric dimensions, i.e., the distance L of the oscillation center and the oscillation length l of the absorber mass and the turning angle β of the absorber mass, are variable or constant depending on the oscillation angle φ of the pendulum. This means that at least one of the following conditions 1.)-4.) must be fulfilled:
         1.) Distance of the oscillation center L=f(φ), wherein f(φ) is a function of the pendulum oscillation angle or L=constant;   2.) Oscillation length of the absorber mass l=f(φ); or l=constant;   3.) Turning angle of the absorber mass β=f(φ); ⊕=0.       

     In order to achieve a centrifugal pendulum  10  that is variable or constant depending on the oscillation angle φ, these three variables, i.e., the distance of the oscillation center L, the oscillation length of the absorber mass l and the turning angle β of the absorber mass can be varied selectively using the oscillation angle of the absorber mass pair φ (center of gravity of the mass). In this way, a specific path shape  18  of the mass center of gravity of pendulum  16 , as shown in  FIG. 1 , is generated with a corresponding rotation of the absorber mass  14 . 
     By using a selective variation, any desired path shape  18  for the mass center of gravity can be achieved with a corresponding rotation of the absorber mass pair and thus, the desired absorber arrangement curve. In this case, the absorber mass  14  executes superimposed translational and rotary motions, i.e., the absorber mass  14  will move with its center of gravity along a path  18  and simultaneously turn around its own center of gravity. 
     In principle, the motions of the absorber mass  14  can be achieved by the motion paths of two points  20 ,  22  of the absorber mass  14 , the length of which (x Li , y Li , x Ri , y Ri ) is determined by the geometric variables H and B as shown in  FIG. 1 . In this case, H is the distance of the first and/or second point  20 ,  22  of the absorber mass  14  from the oscillation center  24 , in this case the axis of rotation of the pendulum disk and/or the pendulum flange  12  (center point of the disk in  FIG. 1 ). B is the distance of the two points  20 ,  22  from each other. For example, in  FIG. 1 , the points  20 ,  22  each have the same distance from the center axis  26 , which runs through the oscillation center  24  or, in other words, the two points  20 ,  22  are symmetrical to the center axis  26 . The respective motion path  28  and/or  30  of the point  20  and/or  22  is asymmetrical or does not run symmetrically. Because of this asymmetric or non-symmetrical running of the respective motion path  28  and/or  30  of the point  20  and/or  22  of the absorber mass  14 , the absorber mass  14  executes superimposed translational and rotary motions. The cutouts or roller cutouts in an absorber mass  14  and/or a pendulum flange  12  do not follow the symmetrical curve of the motion path. This also applies to the cutouts or roller cutouts shown in  FIG. 4 . 
     In this case, the coordinates X Li , Y Li , X Ri , Y Ri  of the motion paths  28 ,  30  of the two points  20 ,  22  of the absorber mass  14  in  FIG. 1  are calculated as follows, for example: 
         x   Ri =0.5 B (cos β i −1)+l, sin φ i +( H−Y   s )sin β i  
 
         x   Ri =0.5 B (1−cos β i )+l i sin φ i +( H−Y   s )sin β i  
 
         y   Ri =0.5 B  sin β i −L i −l i  cos φ i −( H−Y   s )cos β i   +H  
 
         y   Ri =0.5 B  sin β i +L i +l i  cos φ i +( H−Y   s )cos β i   −H  
 
     wherein
         φ i =Oscillation angle of the pendulum   β 1 =Turning angle of the mass and/or absorber mass (mass element)   Y s =Distance of mass center of gravity (mass element)   L 1 =Distance of the oscillation center   l 1 =Oscillation length of the mass and/or absorber mass (mass element)   H=Distance of the first or second point of the absorber mass from the oscillation center   B=Distance of the first and second point from each other       

     A constant absorber order q=constant of the centrifugal pendulum  10  is then present if the path  18  of the mass center of gravity of an absorber mass pair is a circular segment, i.e., if L=constant and l=constant. The mass turning β depends on the oscillation angle φ: 
     
       
         
           
             β 
             = 
             
               arcsin 
               [ 
               
                 
                   
                     l 
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   ϕ 
                 
                 
                   
                     
                       l 
                       2 
                     
                     + 
                     
                       L 
                       2 
                     
                     + 
                     
                       
                         2 
                         · 
                         l 
                         · 
                         L 
                         · 
                         cos 
                       
                        
                       
                           
                       
                        
                       ϕ 
                     
                   
                 
               
               ] 
             
           
         
       
     
     This special case supplies a constant absorber order. 
       FIG. 2  shows a cutout of a centrifugal pendulum  10  of a first embodiment of the invention. As explained in  FIG. 2 , a pendulum flange  12  is shown, on which at least one, or several, pairs of absorber masses  14  are arranged. 
     In this cutout in  FIG. 2 , an absorber mass  14  is mounted on the pendulum flange  12 . As already described with reference to  FIG. 1 , in principle, the motions of the absorber mass  14  is achieved by the motion paths  28 ,  30  of two points  20 ,  22  of the absorber mass  14 , the position of which is determined by the geometric variables H and B. As shown in  FIG. 2 , cutouts or roller cutouts  32  corresponding to the motion paths  28 ,  30  are now formed in the pendulum flange  12 . 
     In a first embodiment, one absorber mass  14  is arranged on an opposite side of the pendulum flange  12 . The two absorber masses  14  are suspended by means of two pins  34  and bearings  36  mounted on them in roller cutouts of the pendulum flange. Here, one pin  34  and its bearing  36  form a spacer element for suspension and guiding of the absorber mass  14  in the respective cutout  32 . The bearings  36  are advantageous because they cause rolling friction instead of sliding friction. Provision of the bearings  36  is optional. The pins  34  connect the two absorber masses to form an absorber mass pair. As previously described, the cutouts  32  or recesses on the pendulum flange  12  have the design or shape of the motion paths  28 ,  30  for two points  20 ,  22  of the absorber mass  14 , as previously described in  FIG. 1 . The curve of the motion path  18  of the absorber mass  14  center of gravity is also shown in  FIG. 1 , as well as the center axis  26  through which the oscillation center  24  runs. The spacer element and/or, in this case, a combination of pin and bearing, preferably, has a diameter that is smaller than the width of the respective cutout  32  in which it is held since otherwise this could lead to undesirable friction. 
       FIG. 3  shows a cross section A-A through the centrifugal pendulum  10  shown in  FIG. 2 . A respective absorber mass  14  is provided on both sides of the pendulum flange  12  or the pendulum disk. As previously shown in  FIG. 2 , the pendulum flange  12  has two cutouts  32  that have the design of the motion paths  28 ,  30  for two points  20 ,  22  of the absorber mass  14  and/or follow their curve. A pin  34  is held in the respective cutout  32  and has a bearing  36 . For example, the bearing  36  can be a roller bearing, thrust bearing or friction bearing, to name three examples. In addition, the pins  34  in the example shown in  FIG. 3  are each connected on both sides with an absorber mass  14 . 
       FIG. 4  shows a cutout of a centrifugal pendulum  10  wherein a pendulum flange  12  is shown on which at least one or more pairs of absorber masses  14  are mounted. The absorber masses  14  are suspended in cutouts  32  or recesses on the respective absorber mass  14  and the pendulum flange  12  by means of rollers  38  as spacer elements. The spacer elements and/or roller  38  preferably have a smaller diameter than the width of the respective cutout  32  in which they are held. 
     A cutout  32  of the pendulum flange  12  is assigned to a cutout  32  of the absorber mass  14 , whereby the two cutouts  32  are arranged over each other. As shown in  FIG. 4 , the respective cutout  32  on the pendulum flange  12  and the assigned cutout  32  on the absorber mass  14  are arranged with respect to each other in such a way that the respective roller  38 , which is guided in the two cutouts  32  contacts the respective cutout  32  of the pendulum flange  12  and/or the absorber mass  14  in a neutral position and/or location  33 , i.e., with an oscillation angle φ=0° (see also the following  FIGS. 6 and 7 ). In this case, the respective cutout  32  on the pendulum flange  12  and the assigned cutout  32  on the absorber mass  14  are arranged with respect to each other as is explained in more detail in the following with the use of  FIGS. 6 and 7 , that respective areas  39  of the cutouts  32  of the pendulum flange  12  and the absorber mass  14 , the radius R s  and/or R m  of which is enlarged in this area starting from the neutral position or location  33  are opposite each other. Correspondingly, areas  40  of the cutouts  32  of the pendulum flange  12  and of the absorber mass  14 , the radius R s  and/or R m  of which is reduced in this area starting from the neutral position and/or location  33  lie opposite each other. 
     In  FIG. 4 , as an example, an absorber mass  14  is located on both sides of the pendulum flange  12 , whereby in  FIG. 4  the absorber mass  14  is shown on the front side of the pendulum flange  12 . The absorber mass with its two cutouts on the reverse side of the pendulum flange  12  is arranged corresponding to the absorber mass  12  and its cutouts on the front side. 
     The centrifugal pendulum and/or the oscillation absorber arrangement  10  with regular absorber mounting curve can be produced with simple rollers, as well as, e.g., stepped rollers. 
     In order to minimize or prevent sliding on the roller pairs  38 , the cutouts or roller cutouts  32  on the respective absorber mass  14  and the pendulum flange  12  are formed by a circular segment or curves deviating from a circular shape. The roller cutouts  32  on the mass  14  and the pendulum flange  12  are formed, for example, starting from the neutral location or starting from the neutral position  33 , by increases in radius and reductions in radius R mΔ  and/or R sΔ  of a circle or curves deviating from a circular segment, as is also shown in  FIGS. 6 and 7 . In  FIG. 4 , roller pairs  38  are each located in the neutral position  33  in which the oscillation angle is φ=0°. In this case, one area  40  or one side of the cutout  32  of the pendulum flange  12  and/or of the absorber mass  14  is formed starting from the neutral position  33 , by a circle or curve deviating from a circular segment using a reduction in radius and in the other area  39  or on the other side of the cutout  32  of the pendulum flange  12  and/or the absorber mass  14  is formed starting from the neutral position  33  by a circle or a curve deviating from a circular segment using a radius enlargement. 
     The outer contour  35  of the absorber mass  14  is formed, for example, by the circular segment with the center in the flange center and with the radius r o =R max −c1, whereby, e.g., c1 ≧0. The inner contour  37  is formed, for example, by the circular segment with the radius r u =R min +c2, whereby, e.g., c2≧0. The lateral contour is e.g., a straight line section that is parallel to the dividing axis γ and at a distance c from it, as shown in  FIG. 4 , whereby, e.g., c≧0. 
     In  FIG. 4 , the following apply: 
     R max =maximum radius of an available construction space; 
     R min =minimum radius of an available construction space; 
     γ=dividing axis with dividing angle γ=360°/2n; and, 
     N=division n&gt;0. 
       FIGS. 6 and 7  show an exemplary embodiment for a cutout  32  or roller cutout  32  for an absorber mass  14  and a pendulum flange  12 . More specifically,  FIG. 6  shows the respective cutout  32  of the pendulum flange of the centrifugal pendulum in  FIG. 4  and  FIG. 7  shows the respectively assigned cutout  32  of the absorber mass of the centrifugal pendulum in  FIG. 4 . As was already described, roller sections  32  are designed by a curve deviating from a circle to minimize or prevent sliding on the roller pairs  38 . The roller cutouts  32  on an absorber mass  14  and a pendulum flange  12  can be formed by a curve deviating from a circle or circular segments as shown in  FIGS. 6 and 7 , by radius increases and radius reductions R mΔ  and/or R sΔ  starting from a neutral location or position  33  at which the oscillation angle φ=0°. A radius reduction or radius increase, is understood to mean, for example, a linear increase or decrease of the radius at a distance from the neutral location. Instead of a linear increase or decrease, a different behavior can also be selected with which the radius becomes larger or smaller with the distance from the neutral position. As shown in  FIG. 4 , the cutouts  32  of the pendulum flange  12  are arranged mirror inverted with respect to each other. In more precise terms, the two cutouts  32  of the pendulum flange can be arranged mirror inverted with respect to the center axis  26  through the oscillation center  24 . Correspondingly, the two cutouts  32  of the respective absorber mass  14  can also be arranged mirror inverted with respect to each other, i.e., mirror inverted to the center axis  26  through the oscillation center  24 . 
     The following apply in  FIGS. 6 and 7 : 
     R s =Radius of the cutout or the recess on the flange; and, 
     R m =Radius of the cutout or the recess on the mass and/or mass element. 
     In the roller cutout  32  shown in  FIG. 6  of the pendulum flange of the centrifugal pendulum, as shown in  FIG. 4 , on both sides and/or in the right and left area of the neutral position  33 , in which the oscillation angle φ=0° and one radius R si  and one radius R s  of the roller cutout  32  is enlarged and one is reduced. More specifically, on one side and/or in one area  39  starting from the neutral position  33 , the radius and/or in this case the outer radius R s  of the roller section  32  is enlarged, in this case by an amount R s←2 , so that R s +R sΔ2  is true. On the other side and/or in the other area  40 , starting from the neutral position  33  of the radius and/or, in this case the outer radius R s  of the roller cutout  32  is reduced, in this case by an amount R sΔ1 , so that R s −R sΔ1  is true. The analogous is also true for inner radius R si  of the roller cutout  32 . The inner radius R si  of the roller cutout  32 , like the outer radius R s  is enlarged from the same amount starting from a neutral position  33  and in an area  39  and in the other area  40  starting from the neutral position  33 , is reduced like outer radius R s  by the same amount (in  FIG. 6  R si −R siΔ1 ). 
     In the roller cutout  32  shown in  FIG. 7  of the absorber mass of the centrifugal pendulum, as shown in  FIG. 4 , on both sides and/or in the right and left area of the neutral position  33 , in which the oscillation angle φ=0° and one radius R mi  and one radius R m  of the roller cutout  32  is enlarged and one is reduced. That is, in one area  39  starting from the neutral position  33 , the radius and/or in this case the outer radius R m  of the roller section  32  is enlarged, in this case by an amount R mΔ2 , so that R m +R mΔ2  is true. In the other area  40 , starting from the neutral position  33  of the radius and/or, in this case the outer radius R m  of the roller cutout  32  is reduced, in this case by an amount R mΔ1 , so that R m −R mΔ1  is true. The analogous is also true for inner radius R mi  of the roller cutout  32 . The inner radius R mi  of the roller cutout  32 , like the outer radius R m  is enlarged from the same amount starting from a neutral position  33  and in an area  39  and in the other area  40  starting from the neutral position  33 , is reduced like outer radius R m  by the same amount (in  FIG. 7  R mi −R miΔ1 ). 
     The amount R m,sΔ1 , by which the radius R m  and/or R s  of the roller cutout  32  of the absorber mass and/or of the pendulum flange is reduced can be equal to or unequal to the amount R m,sΔ2 , by which the radius R m  and/or R s  of the roller cutout  32  of the absorber mass and/or of the pendulum flange is enlarged, i.e., R m,SΔ1 =R m,SΔ2  or R m,sΔ1 ≠R m,SΔ2  or R mi,SiΔ1 =R mi,Si{2  or R mi,SiΔ1 R mi,SiΔ2 . 
     As previously shown in  FIG. 4 , now the respective roller cutout  32  on the pendulum flange  12  and the assigned roller section  32  on the absorber mass  14  are assigned to each other in such a way that the roller  38 , which is guided in the two roller cutouts  32  contacts the respective roller cutout of the pendulum flange and/or the absorber mass in neutral position  33  at an oscillation angle φ=0° (see also  FIGS. 6 and 7 ). In this case, the respective roller cutout  32  on the pendulum flange  12  and the assigned roller cutout  32  on the absorber mass  14  are assigned to each other in such a way, as has especially been shown previously in  FIG. 4 , so that the areas  39  of the roller cutouts  32  of the pendulum flange  12  and of the absorber mass  14 , the radius R s  and R m , respectively are enlarged in these areas  39 , starting from the neutral position and/or location  33 , lie opposite each other. Analogously, the areas  40  of the roller cutouts  32  of the pendulum flange  12  and of the absorber mass  14  with radii R s  and R m , respectively, which are reduced in this area  40  starting from the neutral position and/or location  33 , are opposite each other. Also, like the cutouts  32  of the pendulum flange and of the absorber mass in  FIGS. 4 to 7 , a respective cutout  32 , e.g., of the pendulum flange in  FIG. 2 , is formed of a circle or curve deviating from a circular segment using radius increases and radius reductions R mΔ  and/or R sΔ  from a neutral position (oscillation angle φ=0°). 
     The design of an oscillation absorber arrangement and/or of a centrifugal pendulum includes, e.g., at least one of the following points:
         the oscillation length is variable or constant, depending on the oscillation angle;   the distance of the oscillation center is variable or constant depending on oscillation angle;   the turning angle of the absorber mass is variable or constant depending on oscillation angle;   a specific path shape of the mass center of gravity with a specific turning curve of the absorber mass corresponds to the desired absorber order curve;   the path shape and the turning of the mass center of gravity is achieved by paths of, e.g., two points of the absorber mass;   the absorber masses are suspended, e.g., by means of two pins and bearings mounted on them in the roller cutouts, e.g., of the pendulum disk and/or the pendulum flange, whereby the cutouts in the pendulum disk and/or in the pendulum flange have the design or the curve of the path shapes of two points of the absorber mass;   the absorber masses are, e.g., suspended by means of rollers in the roller cutouts of the pendulum disk and/or the pendulum flange, for example, by means of two rollers;   the cutouts or roller cutouts are formed, e.g., by curves each deviating from a circle or a circular segment; and,   the respective cutout or roller cutout is non-symmetrical and/or it runs along a path and/or motion path that is not symmetrical.       

     As previously described, a centrifugal pendulum or an oscillation absorber device or arrangement is suggested, in which the desired absorber order curve achieved by a specific path shape and a turning curve of the mass center of gravity and in turn by variation of geometry variables over the oscillation angle. The present embodiments, as previously described using  FIGS. 1 to 7 , can be combined with each other, and especially individual characteristics thereof 
     Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention. 
     LIST OF REFERENCE NUMERALS 
     
         
           10  Oscillation absorber device 
           12  Pendulum flange 
           14  Absorber mass 
           16  Pendulum 
           18  Path 
           20  Point 
           22  Point 
           24  Oscillation center 
           26  Center axis 
           28  Motion path (point  20 ) 
           30  Motion path (point  22 ) 
           32  Cutout 
           33  Neutral location or position 
           34  Pin 
           35  Outer contour 
           36  Bearing 
           37  Inner contour 
           38  Roller 
           39  Area of the cutout with enlarged radius 
           40  Area of the cutout with reduced radius