Patent Publication Number: US-2023137020-A1

Title: Seal cartridge with electrically conductive non-woven grounding

Description:
FIELD 
     The present disclosure relates to a seal cartridge with an electrically conductive non-woven element. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Conventional cassette seals are designed to allow high contamination exclusion by multiple exclusion features. 
     Current electrically conducting seal arrangements, such as disclosed in U.S. Pat. No. 10,190,690, make a low impedance connection (grounding) between the shaft and housing in order to eliminate electrical interference. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     A cassette seal arrangement for sealing between a shaft and a housing includes a sleeve configured to be mounted to the shaft and including a cylindrical portion and a radially extending portion extending radially outward from the cylindrical portion. A retainer cartridge includes a main retainer configured to be mounted to the housing and supporting a seal member that includes a main seal lip and an exclusionary retainer connected to the main retainer and supporting an exclusionary seal configured to engage the shaft. An electrically conductive non-woven element is disposed longitudinally between the seal member and the exclusionary seal and engages the retainer cartridge and is configured to engage the shaft. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG.  1    is a cross-sectional view of an exemplary cassette seal arrangement according to a first embodiment; 
         FIG.  2    is a cross-sectional view of an exemplary cassette seal arrangement according to an alternative second embodiment; and 
         FIG.  3    is a plan view of an exemplary electrically conductive non-woven element. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With reference to  FIG.  1   , an exemplary cassette seal arrangement  10  according to the principles of the present disclosure will now be described. The cassette seal arrangement  10  is configured to be mounted between a housing  12  and a shaft  14  for sealing a gap therebetween. 
     The cassette seal arrangement  10  includes a sleeve  16  configured to be mounted to the shaft  14  and including a first cylindrical portion  16   a  that receives the shaft  14  therein and a first radially extending portion  16   b  extending radially outward from the cylindrical portion  16   a . A second cylindrical portion  16   c  extends axially from an outer end of the radially extending portion  16   b  and a second radially extending portion  16   d  extending from an end of the second cylindrical portion  16   c . The sleeve  16  can further include an elastomeric layer  18  on an inner surface of the cylindrical portion  16   a  and on an outboard side of the first radially extending portion  16   b  and the second cylindrical portion  16   c  of the sleeve  16 . 
     A retainer cartridge  20  is configured to be mounted to the housing  12  and includes a main retainer  22  and an exclusionary retainer  24  connected to one another. The main retainer  22  supports a seal member  26  that includes a main seal lip  28  and a pair of dust lips  30   a ,  30   b . The main retainer  22  includes a cylindrical outer portion  22   a  that engages the housing  12  and a radially outwardly bent region  22   b  that extends from a first end of the cylindrical outer portion  22   a  and that defines a shoulder that abuts against the housing. The radially outwardly bent region  22   b  terminates in a U-shaped bend  22   c  that captures an outer end  24   a  of the exclusionary retainer  24 . The main retainer  22  includes a first radially inwardly extending portion  22   d  extending inwardly from a second end of the cylindrical outer portion  22   a . An inner cylindrical portion  22   e  extends axially from a radial inner end of the first radially inwardly extending portion  22   d . A second radially inwardly extending portion  22   f  extends radially inward from a second end of the inner cylindrical portion  22   e . The seal member  26  is molded on an inner end of the second radially inwardly extending portion  22   f . The main seal lip  28  and a first of the pair of dust lips  30   a  engage the cylindrical portion  16   a  of the sleeve  16  while a second dust lip  30   b  of the pair of dust lips engage the first radially extending portion  16   b  of the sleeve  16 . The main seal lip  28  can include a garter spring  32 . The elastomer molded on the second radially inwardly extending portion  22   f  further includes a bumper region opposing the second radially extending portion  16   d  of the sleeve  16 . 
     The outer end  24   a  of the exclusionary retainer  24  is connected to the U-shaped bend  22   c  of the main retainer  22 . The exclusionary retainer  24  further includes a cylindrical portion  24   b  extending axially from the outer end  24   a  in a direction opposite to the main retainer  22 . A radially inwardly extending portion  24   c  extending radially inwardly from the cylindrical portion  24   b  and supporting an exclusionary seal  36 . The exclusionary seal  36  is configured to engage the shaft and can include a pair of dust lips  36   a ,  36   b.    
     An electrically conductive non-woven element  40  is disposed longitudinally between the seal member  26  and the exclusionary seal  36 . The electrically conductive non-woven element  40  has an outer perimeter  40   a  that engages the retainer cartridge  24  and an inner perimeter  40   b  configured to engage the shaft  14 . The electrically conductive non-woven element  40  can be adhered to an outboard face of the first radially extending portion  16   b  of the sleeve  16 . As shown in  FIG.  3   , the electrically conductive non-woven element  40  can further include keyhole slots  42  extending radially inward from the outer perimeter  40   a . The keyholes  42  reduce the radial load of the nonwoven element  40  and reduce the torque required to rotate the shaft  14  and sleeve  16  when in contact with the exclusion/retainer seal. 
     With reference to  FIG.  2    wherein like reference numerals are used to indicate the same or similar elements, an alternative cassette seal arrangement  110  is shown including a modified exclusionary retainer  124  for supporting the exclusionary seal  136  in engagement with an auxiliary sleeve  114  disposed on the shaft  14 . The modified exclusionary retainer  124  has a shorter radially inwardly extending portion  124   c  than the exclusionary retainer  24 . 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.