Patent Publication Number: US-2023147394-A1

Title: Seal for taper roller bearing and taper roller bearing assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese Patent Application no. 202111318942.0, filed Nov. 9, 2021, the contents of which is fully incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention provides a seal for a taper roller bearing and a taper roller bearing assembly. 
     BACKGROUND 
     A taper roller bearing usually has an outer ring, an inner ring, rollers and a cage. Due to the structural characteristics of a taper roller bearing, there is usually an axial position difference between the shoulder with large flange of the inner ring and the shoulder of the outer ring on the same side, which makes it difficult to seal the taper roller bearing. Especially when a taper roller bearing is applied to mechanical equipment with harsh working environment such as lawn mowers, the lack of sealing will lead to leakage of lubricating oil, entry of pollutants into the bearing, reduction of bearing life and various other potential safety hazards. 
     Therefore, it is desirable to provide a sealing structure for taper roller bearing and a taper roller bearing assembly with such a sealing structure, especially for sealing taper roller bearings used in harsh working environment. 
     SUMMARY 
     In view of this, the present invention provides a seal for a taper roller bearing, the seal comprising: a frame having: an outer flange, extending radially outward, an inner flange, extending radially inward, an middle flange, located between the outer flange and the inner flange and extending in an axial direction; wherein the outer flange, the inner flange and the middle flange are integrally formed; a sealing ring, at least connects and covers the radial outer side of the outer flange of the frame, and has at least one sealing lip extending outward in the radial direction. 
     Furthermore, that invention also provide an assembly for a taper roller bear, which comprises a taper roller bearing, wherein an inn ring of that taper roller bearing comprises a shoulder with a large flange; and a seal as described above; wherein the middle flange is in interference fit with the outer circumferential surface of the shoulder, and the inner flange presses against and covers at least a part of the large flange. 
     When that seal and the taper roll bearing assembly containing the seal of the present invention are particularly suitable for mechanical equipment in harsh working environment (for example machines like lawn mowers), external pollutants can be effectively prevented from entering the bearing, the influence on the service life of the bearing can be reduced, internal oil leakage can be effectively prevented, potential safety risks can be reduced, and the maintenance frequency of the equipment can be decreased. Furthermore, the seal of the invention has a simple structure, which can ensure the improvement of precision, the reduction of resistance and heat, and at the same time, can ensure that the main shaft and the housing to which the bearing is applied remain unchanged, so that the seal of the invention can be applied without adaptive modification of other structures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       At least one of the embodiments of the present invention is accurately represented by this application&#39;s drawings which are relied on to illustrate such embodiment(s) to scale and the drawings are relied on to illustrate the relative size, proportions, and positioning of the individual components of the present invention accurately relative to each other and relative to the overall embodiment(s). Those of ordinary skill in the art will appreciate from this disclosure that the present invention is not limited to the scaled drawings and that the illustrated proportions, scale, and relative positioning can be varied without departing from the scope of the present invention as set forth in the broadest descriptions set forth in any portion of the originally filed specification and/or drawings.  FIG.  1 A  shows a bottom view of a seal according to a preferred embodiment of the present invention. 
         FIG.  1 B  shows a cross-sectional view of a seal according to a preferred embodiment of the present invention, taken along the B-B line of  FIG.  1 A . 
         FIG.  2    shows a part of a taper roller bearing assembly with a seal according to a preferred embodiment of the present invention. 
         FIG.  3    shows the installation manner of the seal and taper roller bearing assembly according to the preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Those of ordinary skill in the art will appreciate from this disclosure that when a range is provided such as (for example) an angle/distance/number/weight/volume/spacing being between one ( 1  of the appropriate unit) and ten (10 of the appropriate units) that specific support is provided by the specification to identify any number within the range as being disclosed for use with a preferred embodiment. For example, the recitation of a percentage of copper between one percent (1%) and twenty percent (20%) provides specific support for a preferred embodiment having two point three percent (2.3%) copper even if not separately listed herein and thus provides support for claiming a preferred embodiment having two point three percent (2.3%) copper. By way of an additional example, a recitation in the claims and/or in portions of an element moving along an arcuate path by at least twenty(20°) degrees, provides specific literal support for any angle greater than twenty(20°) degrees, such as twenty-three (23°) degrees, thirty(30°) degrees, thirty-three-point five(33.5°) degrees, forty-five(45°) degrees, fifty-two(52°) degrees, or the like and thus provides support for claiming a preferred embodiment with the element moving along the arcuate path thirty-three-point five(33.5°) degrees. For convenience of explanation, the rotational axis direction of a taper roller bearing is referred to as axial direction, and the direction perpendicular to the axial direction is referred to as radial direction. The term “inner/inside” refers to the direction towards the inner side of the bearing, whereas the term “outer/outside” refers to the direction towards the outer side of the bearing. 
     The invention provides a seal, which is especially suitable for the taper roller bearing to seal on the side of the flange thereof. The invention also provides a taper roller bearing assembly comprising the seal. 
     Specifically, referring to  FIGS.  1 A- 3   , a seal  1  according to an embodiment of the present invention includes a frame  10  and a sealing ring  11 . Specifically, the frame  10  and the sealing ring  11  are formed in a ring shape to adapt to the shape of the taper roller bearing  2 . Furthermore, as shown in  FIG.  2   , the inner ring  21  of the taper roller bearing  2  (hereinafter simply referred to as the bearing  2 ) includes a shoulder  211  with a large flange  212 , and there is an axial position difference between the shoulder  211  and the shoulder  221  of the outer ring  22  on the same side. The shoulder  211  also has an outer circumferential surface  213 . 
     In the seal  1  of this embodiment, the frame  10  has an outer flange  101 , an inner flange  102  and a middle flange  103 . Specifically, the outer flange  101  extends radially outward. The inner flange  102  extends radially inward. The middle flange  103  is located between the outer flange  101  and the inner flange  102  and extends generally in the axial direction. That is, the middle flange  103  extends in the axial direction with respect to the outer flange  101  and the inner flange  102 . Therefore, in the cross section of the sealing ring, the three flanges form, for example, a substantially T-shaped structure, especially as shown in  FIG.  2   . When the seal  1  is installed on the bearing  2 , the middle flange  103  extends toward the taper roller bearing  2 . 
     Further, the outer flange  101 , the inner flange  102  and the middle flange  103  of the frame  10  are integrally formed. And further preferably, the thickness of the middle flange  103  may be greater than thickness of the outer flange  101  and the inner flange  102 , for example. The middle flange  103  with a greater thickness can provide more strength, so that after the seal  1  is assembled to the bearing  2  through interference fit with the shoulder  211 , it can be ensured that the seal  1  will not easily fall off during the running of the bearing  2 . 
     According to some preferred embodiments, for example, the outer flange  101 , the inner flange  102 , and the middle flange  103  of the frame  10  can be integrally formed by stamping a steel or any other suitable material. In the frame  10  formed by sheet stamping process, the middle flange  103  is formed to have a sheet folded portion in the axial direction, as shown by the oval portion in  FIG.  1 B , so that the thickness of the middle flange  10  is greater than thickness of the outer flange  101  and/or the inner flange  102 . For example, according to a preferred embodiment, the thickness of the middle flange  103  of such folded structure can be twice the thickness of the outer flange  101  or the inner flange  102  of the frame  10 , respectively. 
     Of course, it should be understood that the frame can also be formed by any other suitable materials and working processes, for example, it can be formed by injection molding of materials such as resin, etc., depending on the bearings, seals, structures and occasions to which they are to be applied. Meanwhile, similar to the middle flange  104  of the folded configuration as described above, the thickness of the middle flange formed by the injection molding process is set to be greater than that of the outer flange and/or the inner flange, for example, the thickness of the middle flange may be 1.5-3 times of the thickness of the outer flange and/or the inner flange. 
     Further, when the seal  1  is installed on the bearing  2 , the middle flange  103  of the frame  10  can engage with the outer circumferential surface  213  of the shoulder  211  of the bearing inner ring  21  by interference fit, and the inner flange  102  can press against and cover at least a part of the large flange  212  of the shoulder  211 . For example, the inner flange  102  can press against and cover more than half of the large flange  21  of the shoulder  211 . Therefore, the middle flange  103  and the inner flange  102  are preferably formed to have certain rigidity and appropriate dimensions, so that the sealing ring  1  can be firmly interference-fitted with the shoulder  211  of the bearing inner ring  21  and cover the appropriate part of the large flange  21  without affecting the running of the bearing. 
     Furthermore, the sealing ring  11  of the seal  1  is connected to and covers at least the radial outer side  1011  of the outer flange  101  of the frame  10 . In the embodiment shown in  FIG.  3   , the sealing ring  11  may only be connected to and cover the radially outer side of the outer flange  101 . In the preferred embodiment shown in  FIGS.  1 A- 3   , for example, the sealing ring  11  can further connect and cover the transition from the middle flange  103  to the outer flange  101  and the inner flange  102 . Therefore, for example, in the case of forming a frame by stamping a sheet, the sealing ring  11  can cover the gap at the above-mentioned transition of the middle flange  103  to prevent the gap from being polluted or the like. Further, preferably, the sealing ring  11  can be connected to and cover a part of the inner flange  102 , for example, as shown in  FIGS.  1 A- 2   . 
     For example, the connection of the seal  1  can be achieved by bonding with suitable adhesive or by any other suitable means. Furthermore, the sealing ring  11  can be made of suitable materials, such as nitrile rubber, hydrogenated nitrile rubber, fluororubber (more preferably), polyurethane, etc., and can also be made of polymer elastomer or even polytetrafluoroethylene polymer material. 
     In addition, the sealing ring  11  also has at least one sealing lip  112  extending outward in the radial direction, which can be in interference fit with the wall W of the housing used to accommodate the taper roller bearing. In the preferred embodiment shown in  FIGS.  1 A- 3   , the sealing ring  11  may include three sealing lips  112 . 
     According to a further preferred embodiment, the frame  10  may further include a supporting flange  104 . The supporting flange  104  is integrally formed with the outer flange  101  and extends from the outer edge  1011  of the outer flange  101  in the axial direction. In other words, by using the axial position difference between the flanges of the outer ring and the inner ring of the bearing  2  as described above, the supporting flange  104  can extend from the outer edge  1011  toward the outer ring  22  of the bearing  2  to form a groove  105  between the supporting flange  104  and the middle flange  103 . 
     This supporting flange  104  extending along the axial direction can form a structure capable of withstanding the pressure from the radial direction, and at the same time, it also provides flexibility for the frame  10  and the whole seal  1 , thus strengthening the structure of the seal  1 . In addition, the groove  105  can also form a space for avoiding the edge of the cage in the bearing  2 , so as to prevent the seal  1  from affecting the running of the bearing  2 . 
     Further, preferably, the supporting flange  104  extends parallel to the axial direction from the outer edge  1011  of the outer flange  101 . Alternatively, the supporting flange  104  extends inclinedly outward relative to the axial direction from the outer edge  1011  of the outer flange  101 . 
     In the preferred embodiment shown in  FIGS.  1 A- 3   , the supporting flange  104  extends inclinedly outward relative to the axial direction (“extends upward” in the orientation shown in  FIG.  2   ), and its inclination angle is, for example, 5-15°. Three sealing lips  112  extend from the part of the sealing ring  11  that completely covers the supporting flange  104 . When the seal with such a configuration is assembled on the bearing  2  and then installed on the structure to which the bearing  2  is applied (such as a lawn mower, etc.), the interference fit between the bearing housing W and the sealing lip  112  will press the sealing lip  112 , thus forming a seal. At the same time, due to the inclined configuration of the supporting flange  104 , it can well withstand the pressure in the radial direction and support the sealing lip  112  there above. In addition, as mentioned above, all the structures of the frame  10  can be integrally formed through the stamping process, including the outer flange  101 , the inner flange  102 , the middle flange  103  and the supporting flange  104  can be integrally formed. 
     The sealing ring  11  also preferably includes a part that completely covers the supporting flange  104  and is connected with the supporting flange  104  by bonding agent. This bonding method is the same as that for the sealing ring  11  and the outer flange  101  mentioned above. Furthermore, for example, at least one sealing lip  112  may extend from the part of the sealing ring  11  that completely covers the supporting flange  104 . 
     According to a further preferred embodiment, at least a part of the inner flange  102  can be sandwiched between the large flange  212  and the fixation structure for the taper roller bearing. As shown in  FIG.  2   , when the bearing  2  is assembled to the shaft, the inner flange  102  is sandwiched between the shoulder S of the shaft and the large flange  212  of the shoulder  211  of the bearing  2 , thereby further strengthening the fixing and positioning of the seal  1 . It should be understood that besides the shoulder S, the fixation structure can be any other fixation structure related to the installation of bearings, shafts and seals. 
     Referring to  FIG.  3   , the preferred installation method for installing the seal according to the present invention will be described as follows: the bearing  2  is fixed on a workbench (not shown but below the bearing  2 ), and the seal  1  is placed on the bearing  2 , so that the related assembly structures of the two are roughly aligned; then, by using a hydraulic press, the seal  1  is pressed down onto the bearing  2  (as shown by the arrow in  FIG.  3   ), so that the middle flange  103  of the seal  1  is in interference fit with the shoulder  211  with the large flange of the inner ring of the bearing  2 . The taper roller bearing equipped with the seal of the present invention can then be applied to related shaft structures. 
     The invention provides a seal especially suitable for taper roller bearings and a taper roller bearing with the seal. The seal can be manufactured in a simple manner and can be installed to the bearing in a simple installation manner. 
     Therefore, when it is applied to mechanical equipment in harsh working environment (such as lawn mowers), it can effectively prevent external pollutants from entering the bearing and reduce the influence on the bearing life. Moreover, through the interference fit between the middle flange and the shoulder and placing the inner flange between the bearing shoulder and the fixation structure, the internal oil leakage can be effectively prevented, the potential safety hazards can be reduced, and the maintenance frequency of the equipment can be decreased. Furthermore, the seal of the invention has a simple structure, which can ensure the improvement of precision, the reduction of resistance and heat, and at the same time, can ensure that the main shaft and the housing to which the bearing is applied remain unchanged, so that the seal of the invention can be applied without adaptive modification of other structures.