Abstract:
A chain guide element having a first guide rail and a second guide rail which is spaced from the first guide rail to guide a moving chain therebetween. On each lateral side of the chain guide element connecting elements connect the two guide rails in spaced relationship to slidably receive a moving chain. First supporting elements are positioned on the laterally arranged connecting elements that connect the first and second guide rails, and second supporting elements are carried by a stationary component to cooperate with the first supporting elements so that the chain guide element is pivotable and is linearly movable relative to the second supporting elements.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is the U.S. national phase application under 35 U.S.C. §371 of International Application Serial No. PCT/DE2014/200416, having an international filing date of 21 Aug. 2014, and designating the United States, which claims priority based upon German Patent Application No. DE 10 2013 218 942.7, filed on 20 Sep. 2013, the entire contents of each of which applications are hereby incorporated by reference herein to the same extent as if fully rewritten. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a chain guide element, in particular for a CVT transmission of a motor vehicle. 
     Description of the Related Art 
     Chain guide elements are known in CVT transmissions according to the prior art to guide the chain and damp strand vibrations of the chain. 
     For example, DE100 17 005 A1 discloses a continuously adjustable, chain-driven conical-pulley transmission as a CVT transmission in which a chain guide element is made as a receiving rail. The chain guide element includes an upper and a lower rail, which are connected to each other by means of at least one lateral arm as a spacer, while the chain runs between the two rails in the longitudinal direction of the rails. 
     The chain guide element is located within the transmission between two conical disk pairs, and is situated so that it can be pivotable and linearly movable by means of a combined pivoting and translatory support, so that the chain guide is able to adapt to the particular course of the chain when the transmission ratio of the transmission is changed by changing the running radii of the chain in the conical disk pairs. At the same time, the chain guide has a receptacle that opens downward, below the lower rail, which can be placed on a guide tube or bolt that is positioned parallel to the axes of the conical disk pairs and between them. Downward in this connection means directed toward the center plane which runs through the axes of the two conical disk pairs. 
     If the chain changes from one extreme position to the other extreme position, the chain guide element describes a motion which consists of a combination of a rotational motion around the guide tube and a linear motion. This leads to disadvantages, which are also caused in particular by the fact that a guide tube crossing the construction space or a bolt is used to support the chain guide element. The use of the construction space by the receptacle located below the rails means that the construction space for the rails and the connecting element is limited, which results in these components having to be of relatively narrow design, which has a negative effect on their rigidity. This also has negative effects on the damping of strand vibrations of the first and second orders, and on the fabrication. 
     An object of the present invention is to create a chain guide element by means of which improved vibration damping of a chain strand is achievable, and which is nevertheless simply and economically constructed. 
     SUMMARY OF THE INVENTION 
     One exemplary embodiment of the invention relates to a chain guide element having a first rail and a second rail spaced from the first rail, there being in each case on both sides of the rails lateral connecting elements that connect the two rails to each other. Two supporting means are provided in order to support the rails so that they are pivotable and linearly movable. A first supporting means is positioned on the lateral connecting elements, and a second supporting means works together with the first supporting means, both of which are positioned to the side of the rails. This results in the supporting means being positioned at the level of the chain which is running between the rails of the chain guide, and the pivot point being located at the level of the chain so that the pivoting motion of the chain guide is essentially only a rotational motion. It also results in the supporting means being provided to the side of the rails, and thus to the side of the chain, so that more construction space is available for the rails and for the connecting element, and so that the rails and connecting element can be of a more solid design, which has a positive effect on the rigidity of the rails and on the ease of fabrication. 
     Accordingly, it is at the same time especially advantageous if the first and second supporting means are positioned essentially at the level of the chain in the chain guide element 
     It is also advantageous if the first supporting means in each case have a receptacle which is engaged in each case by a projection of the first supporting means, or if the first supporting means in each case have a projection which in each case engages a receptacle of the second supporting means. Secure support of the chain guide element by means of the first and second supporting means is achieved thereby. Accordingly, the chain guide element can pivot around the projection by means of the receptacle. If the receptacle is elongated, a radial equalization can also occur. 
     It is also advantageous if the projection and the receptacle are positioned essentially at the level of the chain in the chain guide element. 
     In addition, it is useful if the second supporting means are connected on an axis which is spaced from the first and second supporting means. This enables the second supporting means to be connected via the axis with a transmission housing. If the axis runs in the zone between the conical disk pairs of the chain-driven, conical-pulley transmission, then construction space can also be saved. 
     Furthermore, it is advantageous if the second supporting means protrude downward from the axis as projections, the projections being in the form of pegs extending in the axial direction. The engagement with the receptacles then takes place in the axial direction. 
     It is also advantageous if the second supporting means protrude downward from the axis as projections, the projections being in the form of pan-like plates extending in the radial direction. As a result, engagement with the receptacles can take place essentially from the radial direction. 
     It is especially advantageous if the second supporting means are designed as pockets which are open in the axial direction, and the first supporting means are designed as projections which engage the pockets in the axial direction. 
     It is also especially advantageous if the radial dimension of the receptacle is greater than the radial dimension of the projection engaging the receptacle. 
     Furthermore, it is useful if a projection has an encircling, ring-shaped bulge, while a receptacle has a ring-shaped groove to receive the ring-shaped-bulge. 
     The present invention will be explained in greater detail below on the basis of preferred exemplary embodiments, in combination with the corresponding figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawing figures show the following: 
         FIG. 1  is a schematic side view of a chain-driven converter having a chain guide element, 
         FIG. 2  is a schematic perspective view of a chain-driven converter having a chain guide element, 
         FIG. 3  is a side view of a chain guide element, 
         FIG. 4  is a perspective view in a cutaway of a chain guide element, 
         FIG. 5  is a supporting element, 
         FIG. 6  is a schematic perspective view of a chain-driven converter having a chain guide element, 
         FIG. 7  is a supporting element, and 
         FIG. 8  is a perspective view of a cutaway chain guide element. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a chain-driven converter  1 , in particular of a continuously variable transmission or CVT transmission, having a first conical disk pair  2  and a second conical disk pair  3 . Positioned between the two conical disk pairs  2 , 3 , as an endless torque-transmitting means, is a chain  4  encircling the two conical disk pairs  2 , 3 . To guide the chain  4  between the two conical disk pairs  2 , 3 , a first chain guide element  5  and a second chain guide element  6  are provided, which guide the chain in passing from the first conical disk pair  2  to the second conical disk pair  3  and vice versa. The chain guide elements  5 , 6  are supported by supporting means  7 , 8  so that they are pivotable and linearly movable, so that the arrangement of the respective chain guide elements  5 , 6  is able to adapt to the course of the chain  4 . 
     The chain guide elements  5 , 6  include a first rail  9  and a second rail  10 , which are spaced from each other to form an intermediate space in which the chain  4  runs within the chain guide elements  5 , 6 . The two rails  9 , 10 , the first rail  9  and the second rail  10 , are connected with each other laterally by means of connecting elements  11  in order to fix the rails  9 , 10  relative to each other. 
     The supporting means  7 , 8  include first supporting means  7 , which are positioned to the side on the respective connecting element  11 , and second supporting means  8 , which work together with the first supporting means to support the chain guide element. The second supporting means  8  are positioned here so that they engage the first supporting means  7 , or the first supporting means  7  engage the second supporting means  8 . 
       FIG. 2  shows the exemplary embodiment of  FIG. 1  in a perspective. The chain-driven converter  1  has a first conical disk pair  2  and a second conical disk pair  3 , there being a chain  4  encircling the conical disk pairs  2 , 3  as an endless torque-transmitting means. Between the conical disk pairs  2 ,  3  chain guide elements  5 ,  6  are provided, which are positioned in respective opposing spaces, for example triangular, between the conical disk pairs  2 , 3 , and protrude part way into the gap between the conical disk pairs  2 ,  3 . 
     The first supporting means  7  are in the form of cutouts, which are formed in the lateral connecting elements  11  in order to receive a projection which forms the second supporting means  8 , and which is oriented in the axial direction of the conical disks. The dimension of the cutout  7  is oval and elongated, so that the second supporting means  8  also has room for radial displacement relative to the axial direction of the conical disks. 
     The second supporting means  8  is formed by a projection or peg protruding in the axial direction, which is connected to an axis  12  by means of a connecting element  13 . The chain guide elements  6 , 7  can pivot or move linearly relative to the second supporting means  8 , in order to follow the position of the chain in encircling the conical disk pairs  2 ,  3 . 
       FIGS. 3,4  show the chain guide elements  5  and  6  in a side view and a perspective partial view, respectively. The chain guide element  5  has a first rail  9  and a second rail  10 , which are spaced apart from each other. The rails extend in the lateral direction. Positioned to the side of the rails  9 , 10  in each case are connecting elements  11 , which connect the first rail  9  to the second rail  10  laterally. In the central region  15 , the rails  9 , 10  form an essentially rectangular channel  16  with the respective lateral connecting elements  11 , and through which the chain runs. 
     The rails  9 , 10  extend in the longitudinal direction of the chain. As can be seen in  FIG. 4 , the chain guide elements  5 , 6  are designed in two parts, with two shells  17 , 18  forming the chain guide elements  5 , 6 , with the upper rail  9  and the lower rail  10  being divided in half in the longitudinal direction, and together with a connecting element  11  forming a shell  17  and  18  respectively. To join the two shells  17 , 18 , connecting means  14 , such as for example screws or clips etc., are provided, which are passed through flanges  19  which extend upwardly from the rails  9 , 10 . 
     It can be seen in  FIGS. 3 and 4  that the first supporting means  7  and the lateral connecting elements  11  are integrated, while the second supporting means  8  work together with the first supporting means  7  to support the chain guide elements  5 , 6 . The first supporting means  7  are designed here as cutouts, which are open in the axial direction, relative to the conical disk pair axes, and are engaged by the second supporting means  8  designed as projections. 
     In this connection, it is evident in  FIG. 4  that the second supporting means  8 , designed as projections, have encircling, ring-shaped annular bulges  20 , which correspond to ring-shaped, encircling annular grooves  21  of the first supporting means  7 , in order to achieve securement when annular ridges  20  engage the annular grooves  21 . 
       FIG. 5  shows a second supporting means  8  having an axle  12 , the supporting means  8  being connected to the axle  12  by means of connecting elements  13 . The two second supporting means  8  extend from the connecting elements  13  in the axial direction, relative to the conical disk pair axes and face toward each other. The connecting elements  13  connect the two supporting means  8  to the axle  12 , which is oriented in the axial direction, and the connecting elements  13  extending from the axle  12  in the radial direction. The axle  12  extends outwardly in the axial direction relative to the connecting elements  13 , in order to be situated and supported, for example in receptacles found in a transmission housing. 
       FIG. 6  shows a chain-driven converter  30  which has a first conical disk pair  31  and a second conical disk pair  32 , while a chain  33  encircles the two conical disk pairs  31 , 32 . In addition, chain guide elements  34 , 35  are provided. Only chain guide element  34  is shown, while chain guide  35  has not been shown for better visibility. Alternatively, only one chain guide element can be provided with a chain-driven converter. 
     The chain guide elements  34 , 35  in turn have rails  36 ,  37 , which are designed to be set apart from each other, and which are connected with each other by means of lateral connecting elements  38 . First supporting means  39  are formed on the lateral connecting elements  38  as receptacles, which are engaged by second supporting means  40 . As shown in  FIG. 7 , the second supporting means  40  are formed as pan-like, circular plates, which are connected to an axle  42  by means of a link  41 . For stability, the second supporting means  40  formed as a pan-like plate is connected to the axle  42  by means of a bracing element or gusset  43 , which is connected both to the axle  42  and to the pan-like, circular plate  40  and has a triangular form. The receptacle that receives second supporting means  40 , in this case, is approximately circular. 
       FIG. 8  shows another alternative configuration of a chain guide element  50 , having a first rail  51  and a second rail  52  which are connected with each other by means of lateral connecting elements  53 . The first supporting means  54  are connected to the lateral connecting elements  53  or are formed in a single piece with them, the first supporting means being formed as pegs or projections extending in the axial direction, relative to the conical disk pair axes. The second supporting means  55  are formed as receptacles, which are open in the axial direction to receive the first supporting means  54 , which are formed as projections extending axially from lateral connecting elements  53 . 
     The projections of the first supporting means  54  include ring-shaped, annular bulges  56 , which correspond to ring-shaped, annular grooves  57  in the second supporting means  55  in order to ensure reliable guidance of the projections in the receptacles. 
     In accordance with the invention, it is advantageous to integrate the support of the chain guide element into a housing of the transmission. In so doing, the second supporting means is preferably integrated into the housing of the transmission. Thus, the second supporting means can be received, for example, into a receptacle in the transmission housing. 
     The receptacle, as the first or second supporting means, can be designed as a largely closed end receptacle, which is open in the lateral direction to be able to receive the respective other supporting means. Alternatively, the inner circumference of the receptacle opening can be formed so that it is open on one end or on two ends, so that the other supporting means can be inserted laterally into the receptacle.  FIGS. 2, 3, and 6  show receptacles which are open on one end, and which are formed so that they are open radially on the inside of lateral connecting element  11 . Thus, the alternative configurations can be formed such that the receptacles can be completely closed on their circumference, or, alternatively, are open on one or both ends. 
     In the case of the open receptacles, securing elements  58  (see  FIGS. 2 and 3 ) can be provided, for example as flexible projections or catch tabs, which serve to protect against loss and are intended to prevent a supporting means from slipping out of the receptacle. To that end, in  FIGS. 2 and 3  securing elements  58  in the form of projections are provided, which limit the opening width of the receptacle and are elastically deformable, in order to allow a supporting means to be inserted into and retained within the receptacle.