Patent Publication Number: US-2022235819-A1

Title: Elastic bearing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German Patent Application No. DE 10 2021 101 999.0, filed Jan. 28, 2021, the contents of which are hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The invention relates to an elastic bearing. 
     BACKGROUND 
     Elastic bearings are known from practice and can comprise a mass, such as an absorber mass, and a mounting sleeve inserted in a mounting hole of the mass. The sleeve can be used to connect a vibrating device (absorber function) and/or a device against which vibrations are to be isolated (decoupling function). An elastomer layer is arranged between the mass and the mounting sleeve. In automotive engineering, for example, it is common to realize an undercut between the mass and the mounting sleeve by means of a radial collar section of the sleeve which has a larger diameter than the fastening bore. A common mounting sleeve comprises a cylindrical section capable of supporting the cylindrical elastomer body, in which a radial overlap between the elastomer layer and the fastening bore provides a cylindrical interference fit with sufficient frictional force. 
     Due to the high number of operating vibration cycles and individual large-amplitude vibration events with corresponding relative movement between the mass and the mounting sleeve in combination with possibly increased temperature, the frictional connection on the elastomer layer may not prevent axial migration of the mass. The pretensioning of the elastomer layer can also cause axial migration of the mass in the long term. After permanent axial displacement of the mass relative to the mounting sleeve, metallic contact with the device can occur or the mass can become completely blocked, with the result that the absorber effect or decoupling effect is no longer present. In addition, axial slippage cannot be excluded or reliably prevented by cardanic levering. 
     It is therefore the task of the invention to create a resilient bearing that enables a more durable and process-reliable fixation of the mounting sleeves over the entire service life. 
     Features and embodiments of the invention are disclosed herein. 
     SUMMARY 
     According to the invention, an elastic bearing is proposed comprising a mass which has at least one mounting hole for a mounting sleeve, the mounting hole being penetrated by a central longitudinal axis, at least one mounting sleeve having a collar section extending in the radial direction and a shaft section extending in the longitudinal direction, the mounting sleeve being fixed in the mounting hole, and an elastomer body which is arranged on the outer circumferential side of the mounting sleeve, the elastomer body having in the region of the shaft section a diameter-widening contour whose diameter increases with increasing longitudinal distance from the mounting sleeve, which is arranged on the outer circumferential side of the mounting sleeve, the elastomer body having, in the region of the shaft portion, a diameter-widening contour whose diameter increases with increasing longitudinal distance from the collar portion, and the mounting hole having a diameter-widening contour which widens to the same extent as the diameter-widening contour of the elastomer body, the elastomer body being prestressed by the mass and the mounting sleeve at least in the radial direction. 
     Due to the diameter-widening contour of the elastomer body, axial expansion of the mounting sleeve in both axial directions can now be reliably prevented. The elastomer body, which can be frustoconical at least in the area of the shaft section, has a radial overlap with the inner contour of the mounting hole. When an axial force is applied, a “normal force” is generated in the friction surface to the elastomer body and/or to the mass, depending on the arrangement of the elastomer body, which prevents unintentional migration out. In addition, the diameter-widening contour of the elastomer body means that the mounting sleeve can return to its original position even after large-amplitude vibration events, since the normal component due to the inclined position of the diameter expansion is higher than with a purely cylindrical interference fit. In addition to the higher normal component, a classic form fit may also be present at the larger diameter of the diameter extension. It is conceivable that the larger diameter of the contour is located on a screw-on side, i.e. on the side into which a fastener or screw can be screwed in order to be screwed to a device there. The device to be insulated from can be, for example, a car body. The elastic bearing can be, for example, a vibration damper, a rubber bearing or a bearing bush. The mass can be, for example, an absorber mass or an auxiliary/secondary unit or a fastening component. 
     The largest outer diameter of the diameter-widening contour of the elastomer body is larger than the smallest inner diameter of the mounting hole (which may also be referred to as a fastening bore or mounting bore) through which the mounting sleeve is to be inserted. As a result, the elastomer body has a radial overlap with the inner contour of the mass. It is therefore advantageous that the elastomer body can be pushed away during assembly when the mounting sleeve is inserted into the fastening bore. After assembly, the elastomer body is supported by the high rigidity of the mass and/or the mounting sleeve. 
     The diameter-widening contours of the fastening bore and the mounting sleeve can run parallel to each other in longitudinal section. 
     According to a possible further development of the bearing according to the invention, the elastomer layer can be supported by the mass or by the mounting sleeve or vulcanized there. The latter embodiment improves a manufacturing process in that the entire mass does not have to be inserted into the mold for vulcanization, which saves a great deal of space in the mold and energy that would otherwise be required to heat the mass. Alternatively, the elastomer layer can be a separate component, which is only in force-fit and/or form-fit contact with the compound and the sleeve. 
     According to a further development of the bearing according to the invention, the mounting sleeve can have a diameter-widening contour in the region of the shaft section, which expands to the same extent as the diameter-widening contour of the elastomer body. Pressing away of the elastomer body after assembly is prevented even more reliably by this rear structure, since the mounting sleeve cannot be compressed and offers the elastomer body no space to escape. 
     According to a further development of the bearing according to embodiments of the invention, the elastomer body can have a collar portion (which may also be referred to as a collar region) which is supported by the collar section and bears against a step in the fastening bore. The elastomer body thus has at least two sections, namely a clamping region in the region of the shaft section of the mounting sleeve, which has the diameter-widening contour, and the axially acting collar region. The collar region can be over-pressed and briefly compressed during assembly, but the force region pulls the mounting sleeve into the assembly position after the pressure is released. To increase the axial or cardanic resistance (with regard to axial/wobble frequency), an elastomer layer can also be arranged in an annular gap between the collar section of the mounting sleeve and a surface of the mass opposite in the radial direction, preferably in one piece with the elastomer body. 
     In accordance with a further development of the bearing, the diameter-widening contour of the elastomer body and the collar region can be designed to preload the elastomer body in the axial direction. For example, by a suitable selection of the geometry and/or arrangement of the diameter-widening contour of the elastomer body and the collar region, both are arranged in an equilibrium position under preload. This results in opposing forces acting on the mounting sleeve. 
     In accordance with a further development of the bearing according to the invention, the elastomer body can have a cavity region which is supported by the shaft section and forms a cavity with the fastening bore. The hollow space region may be arranged in the axial direction between the collar region and the clamping region, preferably directly at least with respect to the clamping region. The outer diameter of the cavity area of the elastomer body can be smaller than the inner diameter of the radially opposite inner surface of the fastening bore. The cavity region serves to facilitate assembly, since the elastomer pushed away by the overlap can press into the cavity region and thus escape. The cavity region can comprise an annular groove which is recessed in the radial direction relative to the diameter-widening contour of the elastomer body or at least relative to an adjacent section. 
     Pursuant to a further development of the bearing according to the invention, the mounting sleeve can have a support section extending in the radial direction, which can be arranged adjacent to the largest diameter of the diameter-expanding contour of the elastomer body. An axial gap between the support section and the largest diameter of the diameter-expanding contour of the elastomer body is also conceivable. In order to increase the clamping effect, the mounting sleeve can have the additional support section, which need not have any bond to or contact with the elastomer body. However, if there is an axial gap, a bond or no bond between the elastomer and the inner sleeve, the elastomer body can deform more easily relative to the support section, thus facilitating insertion into the fastening bore. In the event of disassembly, on the other hand, the elastomer body may be massively supported by the support section. The support section can have an outer diameter that is smaller than the smallest inner diameter of the fastening bore, so that the sleeve can be mounted easily. 
     According to a further development of the bearing according to the invention, the diameter-widening contour of the elastomer body can be designed as a truncated cone contour or as a partial ovoid contour. In this way, the support behavior can be influenced. 
     According to a further development of the bearing according to the invention, the mounting sleeve can have a central passage through which a fastening element, in particular a screw, can pass in the direction of the screw-on side. Preferably, the central passage is designed without an internal thread. 
     According to a further development of the bearing according to the invention, the elastomer body and/or the mounting bore can have an inlet chamfer for the respective other element. The at least one inlet slope is tilted with respect to a cross-sectional plane. This considerably simplifies assembly, since a deformation direction can be specified for the elastomer body and at the same time centering of the elastomer body or mounting sleeve and mounting bore can be performed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, details and advantages of the invention are apparent from the wording of the claims and from the following description of embodiments based on the drawings. Showing: 
         FIG. 1 a    generally illustrates a pre-assembly position of a fastening sleeve according to the invention first version in longitudinal section; 
         FIG. 1 b    generally illustrates an assembly position of the mounting sleeve according to  FIG. 1 a   ; and 
         FIG. 2  generally illustrates a mounting sleeve of the second embodiment according to the invention in longitudinal section. 
     
    
    
     DETAILED DESCRIPTION 
     In the figures, identical or corresponding elements are each designated with the same reference signs and are therefore not described again unless appropriate. Features already described are not described again to avoid repetition and are applicable to all elements with the same or corresponding reference signs, unless explicitly excluded. The disclosures contained in the entire description are applicable mutatis mutandis to identical parts with identical reference signs or identical component designations. Also, the positional indications selected in the description, such as top, bottom, side, etc., are related to the directly described as well as depicted figure and are to be transferred mutatis mutandis to the new position in the event of a change of position. Furthermore, individual features or combinations of features from the different embodiment examples shown and described can also represent independent, inventive solutions or solutions according to the invention. 
       FIGS. 1 a  and 1 b    show half-sided views of identical elastic bearings  2  shown as vibration dampers  3 .  FIG. 1 a    shows a pre-assembly position in which a mounting sleeve  8  (which may also be referred to as a fastening sleeve) has not yet been placed in a mounting hole  6 , and  FIG. 1 b    shows an assembly position in which this placement in a screw-in direction E has already been carried out. Therefore, reference signs can be transferred to the respective other figure. 
     The bearing  2  comprises a mass  4 , which is shown as an absorber mass  5 . The mass  4  comprises at least one mounting hole  6 , which is designed to be continuous. A central longitudinal axis Z passes through the mounting hole  6  in the axial direction A and longitudinal direction L respectively. The mounting hole  6  has a contour  18  on the inner circumference. The bearing  2  also comprises at least the one mounting sleeve  8 , which comprises a base body  9  with a collar section  10  extending in radial direction R and a shaft section  12  extending in longitudinal direction L. The mounting hole  6  and/or the mounting sleeve  8  may or may not be rotationally symmetrical with respect to the central longitudinal axis Z. The mounting sleeve  8  has a central through-hole  22  extending along the central longitudinal axis Z, through which a fastening element, in particular a screw, can engage in the direction of screw-in E towards a screw-on side  42  through the central through-hole  22  and be screwed there to a device. An elastomer body  14  is arranged on the outer circumference of the mounting sleeve  8 , which can also be vulcanized onto the mounting sleeve  8 . The elastomer body  14  has a contour  16  on the outer circumferential side. The elastomer body  14  can be rotationally symmetrical with respect to the central longitudinal axis Z. 
     The longitudinal sectional courses of the contour  18  of the mounting hole  6  and of the contour  16  of the mounting sleeve  8  are matched to one another in such a way that in the assembly position they reliably prevent axial movement of the mounting sleeve  8  in at least the axial direction A. For this purpose, the contour  16  of the elastomer body  14  is designed to widen in diameter at least in the region of the shaft section  12 , its diameter increasing with increasing longitudinal distance from the collar section  10 . In addition, the mounting sleeve  8  has a diameter-widening contour  20  in the region of the shaft section  12 , which expands to the same extent as the diameter-widening contour  16  of the elastomer body  14  in order to build behind the latter. In longitudinal section, the contours  16  and  20  run parallel. 
     The elastomer body  14  thus has, at least in sections, a truncated cone contour, the larger diameter of the contour  16  being located on the screw-on side  42 . The diameter-widening contour  16  of the elastomer body  14  is supported by a clamping area  28  in the region of the shaft section  12  of the mounting sleeve  8 . The elastomeric body  14  also has two further portions, namely a collar portion  24  which is carried by the collar section  10  and in the assembled position abuts a step  30  in the mounting hole  6 , and a cavity area  26  which is carried by the shaft section  12  and forms a cavity  32  with the mounting hole  6 . To form the cavity area  26 , the elastomer body  14  has an annular groove  48  which recedes inwardly in the radial direction R with respect to the diameter-widening contour  16 . An elastomer layer can also be arranged in an annular gap  44  between the collar section  10  of the mounting sleeve  8  and the opposite surface of the mas-se  4  in radial direction R. 
     The contour  18  of the mounting hole  6  is designed to widen in diameter, at least in sections. The contour  18  expands to the same extent as the diameter-widening contour  16  of the elastomer body  14 . The diameter-widening contour  16  of the elastomer body  14  and its collar region  24  are dimensioned in relation to the mounting hole  6  in such a way that the elastomer body  14  is preloaded in the axial direction A and radial direction R. In the assembly position, the diameter-widening contour  16  and the collar region  24  are arranged in an equilibrium position under pretension. 
     Fig. la shows that the elastomer body  14  has a radial overlap  46  with the contour  18  of the mounting hole  6 , at least at its point with the largest diameter. Thus, when the mounting sleeve  8  is mounted in the mounting hole  6 , the elastomer body  14  can be pressed away from its unloaded state, preferably at least partially into the cavity  32  or the annular groove  48  formed there. Once the mounting sleeve  8  is completely inserted into the mounting hole  6 , it can be pressed over in the screw-in direction E at the end of the assembly. This compresses the collar portion  24  and the clamping area  28  snaps forward or in the direction of the screw-on side  42 . The collar portion  24  then pulls the mounting sleeve  8  a little way into the mounting hole  6  against its compression, counter to the screw-in direction E. The mounting sleeve  8  is then completely inserted into the mounting hole  6 . After this, both the collar portion  24  and the mounting area  28  are mounted in an equilibrium position under pretension. In the opposite direction to the screwing-in direction E, no return travel or axial migration is possible due to the overlap  46 , this effect being reinforced by the rear structure by means of contour  20 . 
     For easier assembly, lead-in chamfers  38 ,  40  can be provided, whereby the lead-in chamfer  38  is arranged on the front side of the elastomer body  14  and the inlet chamfer  40  in the mounting hole  6  is only indicated in Fig. la. The inlet chamfers  38 ,  40  are tilted relative to a cross-sectional plane and taper in the direction of the screw-on side  42 . The inlet chamfers  38 ,  40  can be designed parallel to one another in longitudinal section, but it is also conceivable with an advantage that the inlet chamfer  40  of the mounting hole  6  has a larger taper or encloses a larger angle with the cross-sectional plane. 
       FIG. 2  also shows a mounting sleeve  8  according to the invention, but now in a stand-alone position. To avoid repetition, only the differences from the mounting sleeve  8  of  FIGS. 1 a  and 1 b    will be described below. 
     The mounting sleeve  8  has a support section  34  extending in the radial direction R, which is formed on the side opposite the collar section  10 . The support section  34  is arranged adjacent to the largest diameter of the diameter-widening contour  16  of the elastomer body  14 , but this need not necessarily be so. Between the supporting section  34  and the elastomer body  14 , an axial intermediate space  36  is formed which is wedge-shaped in longitudinal section. However, such an axial intermediate space  36  need not be present. The elastomer body  14  can also be supported by the support section  34  or vulcanized thereon. The support section  34  has an outer diameter which is smaller than the smallest inner diameter of the mounting sleeve  8 . 
     The invention is not limited to one of the above-described embodiments, but can be varied in many ways. All features and advantages resulting from the claims, the description and the drawing, including constructional details, spatial arrangements and process steps, can be essential to the invention both individually and in the most varied combinations. 
     Within the scope of the invention are all combinations of at least two of the features disclosed in the description, claims and/or figures. 
     To avoid repetition, features disclosed according to the invention should also be considered as disclosed according to the process and be claimable. Likewise, features disclosed according to the method should be considered as disclosed according to the invention and be claimable.