Patent Publication Number: US-2013239710-A1

Title: Fixed Joint Boot Test Fixture Assembly

Description:
TECHNICAL FIELD 
     The disclosure relates to improvements to test fixturing components used in testing sealing boots and clamping designs. 
     BACKGROUND 
     Components for a driveline of a vehicle undergo numerous tests to evaluate the designs. Such testing necessarily involves the fabrication of test fixtures to replicate the operation conditions of the vehicle onto which the components will be mounted. An example of one such component that undergoes routine testing is a boot for driveline assemblies. 
     However, after testing, it has been found that current boot test fixtures are often unusable after removal of the boot from the test fixture because the test fixture design does not facilitate easy separation or disassembly of the boot from the fixed joint components. As such, the fixture components become damaged. Moreover, for components that have painted surfaces, the painted surfaces are often damaged during boot removal. As it is sometimes necessary to clean the fixed joint components of a test fixture or add new grease for the components to complete testing, the inability to easily dissemble the boot from the test fixture without causing damage is problematic. Indeed, currently, when disassembly of a boot from the test fixture causes damage to the fixture, a new test fixture must be fabricated to continue with boot tests. However, each test fixtures takes two-three hours to rebuild and requires additional raw material for the components to be manufacture, thereby increasing testing costs. Further delays in completing testing are experienced to allow for re-fabrication of test components. 
     What is needed is a testing fixture design that permits disassembly of the boot from the test fixture components, without causing damage to those components. A test fixture design that improves the ease of disassembly is also desirable, so as to improve timing of testing. 
     SUMMARY 
     A fixed joint test fixture is disclosed that may be selectively assembled and disassembled. The fixed joint test fixture includes a fixed joint sub-assembly, a shaft member, and a selectively actuatable engagement member. The fixed joint sub-assembly includes an inner bore and a stem member with a channel extending therethrough. The shaft member has an engagement channel formed in an end surface of an engagement end thereof. The engagement member is configured to be received within the engagement channel. The engagement end of the shaft is configured to be received within the inner bore, with the engagement member partially seated within the engagement channel thereof. The engagement member is configured to be advanced from the partially seated position within the engagement channel, thereby causing the shaft member to selectively and frictionally engage with the fixed joint sub-assembly. 
     In one exemplary configuration, the engagement member is a tapered plug that may be advanced in a tapered channel. Relief grooves extend radially outward from the tapered channel. The relief channels expand as the tapered plug is advanced within the tapered channel, thereby causing the shaft to frictionally engage the inner bore of the fixed joint sub-assembly. 
     In another exemplary configuration, the engagement member is a fastener assembly that includes a bolt and a washer. The fastener assembly cooperates with a compressible member to assist in frictionally engaging the shaft within the bore of the fixed joint sub-assembly. As the bolt is advanced into the engagement channel, the washer compressible compressible member such that material is compressed around an end surface of the shaft and within the bore, thereby frictionally retaining the shaft within the bore. 
     In one exemplary arrangement, the channel of the stem member is configured to receive a tool that may be utilized to selectively advance the engagement member within the engagement channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings, illustrative embodiments are shown in detail. Although the drawings represent some embodiments, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present invention. Further, the embodiments set forth herein are exemplary and are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description. 
         FIG. 1  is an exploded elevational view of a test fixture design. 
         FIG. 2  is an elevational view of the test fixture design of  FIG. 1 , being assembled. 
         FIG. 3  is a partially exploded elevational view of the test fixture design of  FIG. 1 , illustrating sealing of the test fixture after assembly. 
         FIG. 4  is an exploded elevational view of an alternative test fixture design. 
         FIG. 5  is a partially exploded elevational view of the test fixture design of  FIG. 4 , partially assembled. 
         FIG. 6  is an elevational view of the test fixture design of  FIG. 4 , being assembled. 
         FIG. 7  is a partially exploded elevational view of the test fixture design of  FIG. 4 , illustrating sealing of the test fixture after assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings,  FIGS. 1-3  illustrate a first exemplary arrangement of a fixed joint boot fixture assembly  10  that is used to test sealing systems, such as boots and clamps (not shown), used with a fixed joint. Fixture assembly  10  includes a fixed joint assembly  12  and a shaft  14 . A plug member  16  is used to operatively connect fixed joint assembly  12  to shaft  14 , as will be explained in further detail below. 
     Fixed joint assembly  12  includes an outer joint part  18  and an inner joint part  20  secured therein in a conventional manner. Outer joint part  18  includes a bore or cavity into which inner joint part  20  is received. A stem  22  is attached to outer joint part  18 . A channel  24  is formed through stem  22  and is configured to open into the bore of outer joint part  18 . As may be seen, channel  24  includes an opening  26  that is formed through an end of stem  22 , to be discussed in further detail below. Access to the bore of outer joint part  18  is advantageous to permit access thereto without requiring complete disassembly of fixed joint  12 , such as, for example, adding lubricant. 
     Inner joint part  20  is arranged within the bore of outer joint part  18 . Inner joint part  20  includes an inner joint bore  28  that includes a plurality of splines  30  to facilitate engagement with shaft  14 . A ball cage (not shown) is also arranged within the bore of outer joint part  18  in a convention manner, with inner joint part  20  being positioned within the cage. 
     Shaft  14  is configured with an engagement end  32 . Engagement end  32  is configured with a splined outer surface  34  that is configured to be received within inner joint bore  28  and engage with splines  30 . Engagement end  32  includes a tapered channel  36  configured to received plug member  16 . As seen in the end view A of shaft  14 , engagement end  32  further includes relief grooves  38 . Relief grooves  38  extend radially outward from tapered channel  36  so as to intersect the splined outer surface  34  of engagement end  32 . While the embodiment depicted in  FIG. 1  (inset A) illustrates two relief grooves  38 , it is understood that additional relief grooves may be provided, including, but not limited to four, or six relief grooves. Relief grooves  38  may be arranged equi-distant from one another. Relief grooves  38  are configured to selectively expand from a relaxed configuration whereby relief grooves  38  have a first defined width to an expanded configuration whereby relief grooves  38  have a second defined width that is greater than the first defined width. An outer diameter of engagement end  32  is configured to expand when relief grooves are in the expanded configuration, as will be explained in further detail below. 
     Referring to  FIGS. 2-3 , assembly of fixture assembly  10  will now be described. Plug member  16 , which is sized to be slightly larger than tapered channel  36 , is partially inserted into tapered channel  36  of shaft  14 . In this configuration, relief grooves  38  are in the relaxed configuration. With plug member  16  partially seated within tapered channel  36 , engagement end  32  of shaft  14  is inserted into a pre-assembled fixed joint assembly  12 . More specifically, engagement end  32  is inserted into the bore of inner joint part  20 , which is preassembled within outer joint part  18 . 
     Next, a tool  40  is inserted through opening  26  of stem  22  and extended through channel  24 . Tool  40  is configured to operatively engage with plug member  16 . In one exemplary arrangement, tool  40  is a hex key. Tool  40  is utilized to seat plug member  16  within tapered channel  36 . As hex key is operated, because plug member  16  is larger than tapered channel  36 , as plug member  16  is seated within tapered channel  36 , relief grooves  38  are expanded into the expanded configuration. The expanded configuration of relief grooves  38  operate to expand engagement end  32  of shaft  14 , thereby creating a frictional engagement between splined outer surface  34  of shaft  14  and splines  30  of the bore of inner joint part  20 . Once plug member  16  is fully seated and shaft  14  is frictionally engaged with fixed joint assembly  12 , tool  40  is removed from stem  22  and a sealing plug  42  may be positioned in opening  26  to seal fixed joint assembly  12 . In one exemplary configuration, both sealing plug  42  and opening  26  are threaded such that plug  42  may be engaged with opening  26  in a threaded engagement. 
     Fixture assembly  10  may also be easily disassembled by reversing the above described steps. More specifically, to disassemble fixture assembly  10 , sealing plug  42  is removed from opening  26 , thereby opening channel  24 . Tool  40  is reinserted into channel  24  and operatively engages with plug member  16 . Tool  40  is then operated to at least partially release plug member  16  from tapered portion  36 . When sufficiently released such that the relief grooves  36  are returned to the relaxed configuration, shaft  14  is disengaged with fixed joint assembly  12 . 
     An alternative embodiment of a fixture assembly  100  is shown in  FIGS. 4-7 . Fixture assembly  100  includes a fixed joint assembly  112  and a shaft  114 . A compressible member  116  that cooperates with a fastening assembly  117  is used to operatively connect fixed joint assembly  112  to shaft  114 , as will be explained in further detail below. 
     Fixed joint assembly  112  includes an outer joint part  118  and an inner joint part  120  secured therein in a conventional manner. Outer joint part  118  includes a bore or cavity into which inner joint part  120  is received. A stem  122  is attached to outer joint part  118 . A channel  124  is formed through stem  122  and is configured to open into the bore of outer joint part  118 . As may be seen, channel  124  includes an opening  126  that is formed through an end of stem  122 , to be discussed in further detail below. Access to the bore of outer joint part  118  is advantageous to permit access thereto without requiring complete disassembly of fixed joint  112 , such as, for example, adding lubricant. 
     Inner joint part  120  is arranged within the bore of outer joint part  118 . Inner joint part  120  includes an inner joint bore  128  that includes a plurality of splines  130  to facilitate engagement with shaft  114 . A ball cage (not shown) is also arranged within the bore of outer joint part  118  in a convention manner, with inner joint part  120  being positioned within the cage. 
     Shaft  114  is configured with an engagement end  132 . Engagement end  132  is configured with a splined outer surface  134  that is configured to be received within inner joint bore  128  and engage with splines  130 . Engagement end  132  includes an engagement channel  136  configured to receive a portion of fastening assembly  117 . More specifically, in one exemplary arrangement, fastening assembly  117  comprises a shoulder bolt  119  and a washer  121 . An engagement end of shoulder bolt  119  is configured to be received within engagement channel  136 . In one exemplary arrangement, engagement channel  136  is configured with threads that operatively engage with threads on shoulder bolt  119 . 
     Compressible member  116  is constructed of any suitable compressible material. A mounting channel  138  is formed through compressible member  116 . Mounting channel  138  has a diameter that is sized to receive shoulder bolt  119  such that shoulder bolt  119  extends through compressible member  116 . However, the diameter of mounting channel  138  is sized to be smaller than an outer diameter of washer  121  such that washer  121  engages a top surface  141  of compressible member  116 , as will be explained in further detail below. Compressible member  116  is further sized to have an outer diameter that corresponds to the inner diameter of inner joint bore  128 . 
     Referring to  FIGS. 5-6 , assembly of fixture assembly  100  will now be described. Compressible member  116  is positioned against an end surface  143  of engagement end  132 , with mounting channel  138  aligned with engagement channel  132 . With washer  121  assembled to shoulder bolt  119 , shoulder bolt is inserted through mounting channel  138  and partially inserted into engagement channel  132  such that fastening assembly  117  and compressible member  116  are loosely assembled to shaft  114 , as shown in  FIG. 5 . 
     Next, turning to  FIG. 6 , engagement end  132  of shaft  114  is inserted into a pre-assembled fixed joint assembly  112 . More specifically, engagement end  132  is inserted into the bore of inner joint part  120 , which is preassembled within outer joint part  118 . Because compressible member  116  is sized to have an outer diameter that generally corresponds with the diameter of inner joint bore  128 , a portion of compressible member  116  extends through inner joint bore  128 . 
     Once shaft  114  is seated within inner joint bore  128 , a tool  140  is inserted through opening  126  of stem  122  and extended through channel  124 . Tool  140  is configured to operatively engage with shoulder bolt  119 . In one exemplary arrangement, tool  140  is a hex key, though it is appreciated that other suitable tools may be utilized. Tool  140  is actuated to seat shoulder bolt  119  within engagement channel  132 . As tool  140  is operated, because compressible member  116  is positioned between end surface  143  of engagement end  132  of shaft  114  and washer  121 , as shoulder bolt  119  advances into engagement channel  136 , compressible member  116  becomes compressed partially within inner joint bore  128  and around engagement end  132 , thereby selectively and frictionally engaging shaft  114  to fixed joint assembly  112 , as best seen in  FIG. 7 . 
     Once shoulder bolt  119  is seated within engagement channel  132  and shaft  114  is frictionally engaged with fixed joint assembly  112 , tool  140  is removed from stem  122  and a sealing plug  142  may be positioned in opening  126  to seal fixed joint assembly  112 . In one exemplary configuration, both sealing plug  142  and opening  126  are threaded such that plug  142  may be engaged with opening  126  in a threaded engagement. 
     Fixture assembly  100  may also be easily disassembled by reversing the above described steps. More specifically, to disassemble fixture assembly  100 , sealing plug  142  is removed from opening  126 , thereby opening channel  124 . Tool  140  is reinserted into channel  124  and operatively engages with shoulder bolt  119 . Tool  140  is then operated to at least partially release shoulder bolt  119  from engagement channel  132 , thereby releasing compressible member  116  from it compressed state. When sufficiently released, compressible member  116  returns to its original diameter that corresponds to the inner diameter of inner joint bore  128  such that shaft  114  may be easily disengaged from fixed joint assembly  112 . 
     The preceding description has been presented only to illustrate and describe exemplary embodiments of the methods and systems of the present invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. The invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. The scope of the invention is limited solely by the following claims.