Patent Publication Number: US-11649888-B2

Title: Isolating decoupler

Description:
FIELD OF THE INVENTION 
     The invention relates to an isolating decoupler, and more particularly, to an isolating decoupler having a shaft comprising an inner race of at least one bearing, and a torsion spring having an end welded to a one-way clutch and having another end welded to a pulley. 
     BACKGROUND OF THE INVENTION 
     Diesel engine use for passenger car applications is increasing due to the benefit of better fuel economy. Further, gasoline engines are increasing compression ratios to improve the fuel efficiency. As a result, diesel and gasoline engine accessory drive systems have to overcome the vibrations of greater magnitude from crankshafts due to above mentioned changes in engines. 
     Due to increased crankshaft vibration plus high acceleration/deceleration rates and high alternator inertia the engine accessory drive system is often experiencing belt chirp noise due to belt slip. This will also reduce the belt operating life. 
     Crankshaft isolators/decouplers and alternator decouplers/isolators have been widely used for engines with high angular vibration to filter out vibration in engine operation speed range and to also control belt chirp. 
     Isolator decouplers are typically assembled with interference or press fits between components. In other cases mechanical connections are used, such as a tang engaged with a receiving groove. In still other cases some use of welding is known combined with use of discrete components. Components include bearings, pulleys and shafts. 
     Representative of the art is U.S. Pat. No. 9,759,266 which discloses an isolating decoupler comprising a shaft, a pulley journalled to the shaft, a torsion spring, the torsion spring comprising a flat surface planar in a plane normal to the rotation axis A-A on each end of the torsion spring, a one-way clutch engaged between the torsion spring and the shaft, a weld bead joining a torsion spring end to the one-way clutch, and a weld bead joining the other torsion spring end to the pulley. 
     What is needed is an isolating decoupler having a shaft comprising an inner race of at least one bearing, and a torsion spring having an end welded to a one-way clutch and having another end welded to a pulley. The present invention meets this need. 
     SUMMARY OF THE INVENTION 
     The primary aspect of the invention is an isolating decoupler having a shaft comprising an inner race of at least one bearing, and a torsion spring having an end welded to a one-way clutch and having another end welded to a pulley. 
     Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings. 
     The invention comprises an isolating decoupler comprising a shaft, a pulley journalled to the shaft on at least one bearing, a one-way clutch engaged with the shaft, a torsion spring engaged between the one-way clutch and the pulley, the shaft comprises an inner race of the at least one bearing, and the torsion spring having an end welded to the one-way clutch and having another end welded to the pulley. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention. 
         FIG.  1    is a cross section of a first embodiment. 
         FIG.  2    is an exploded view of  FIG.  1   . 
         FIG.  3   a    is a perspective view of a weld detail. 
         FIG.  3   b    is a front view of a weld detail. 
         FIG.  4   a    is a perspective view of a weld detail. 
         FIG.  4   b    is a front view of a weld detail. 
         FIG.  5    is a perspective view of a weld detail. 
         FIG.  6    is a cross-section view of a second embodiment. 
         FIG.  7    is an exploded view of  FIG.  6   . 
         FIG.  8   a    is a perspective view of a weld detail. 
         FIG.  8   b    is a front view of a weld detail. 
         FIG.  9   a    is a perspective view of a weld detail. 
         FIG.  9   b    is a front view of a weld detail. 
         FIG.  10    is a perspective of a weld detail. 
         FIG.  11    is a cross-section view of a third embodiment. 
         FIG.  12    is a perspective view of a weld detail. 
         FIG.  13    is a perspective view of a weld detail. 
         FIG.  14    is a perspective view of a weld detail. 
         FIG.  15    is a cross-section view of the third embodiment. 
         FIG.  16 A  is an exploded view of  FIG.  15   . 
         FIG.  16 B  is a detail of  FIG.  16 A . 
         FIG.  17    is a detail of  FIG.  16 A . 
         FIG.  18    is a cross-section view of a fourth embodiment. 
         FIG.  19    is a cross-section view of the embodiment in  FIG.  18   . 
         FIG.  20    is a detail of  FIG.  18   . 
         FIG.  21    is a perspective view. 
         FIG.  22    is a perspective view of a weld detail. 
         FIG.  23    is a perspective view of a weld detail. 
         FIG.  24    is a perspective view of a weld detail. 
         FIG.  25 A  is an exploded view of  FIG.  18   . 
         FIG.  25 B  is a detail of  FIG.  25 A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG.  1    is a cross section of a first embodiment. Isolating decoupler  1000  comprises shaft  10 , pulley  20 , ball bearing  30 , torsion spring  40 , one-way clutch  50  and bearing  60 . Ball bearing  30  may also comprise a needle bearing. 
     Pulley  20  is journalled to shaft  10  through bearing  30  and bearing  60 . Torsion spring  40  is engaged between pulley  20  and one-way clutch carrier  51 . Dust cover  80  prevents debris from entering the device. 
     An outer race  62  of bearing  60  comprises a radially extending flange  61 . Flange  61  is welded to bearing race  62  and is also welded to pulley  20 . 
     End  42  of torsion spring  40  is welded to flange  61 . The other end  41  of torsion spring  40  is welded to clutch carrier  51 . Clutch carrier  51  is press fit on one-way clutch  50 . One-way clutch  50  is an anti-rotation feature that prevents rotation of the pulley in a predetermined direction while allowing rotation of the pulley in the opposite direction. 
     Receiving portion  11  is used to hold shaft  10  in a fixed position during assembly. 
     All embodiments have at least one of the bearings positioned inside the axial extent of the torsion spring envelope, for example, bearing  60  in this embodiment. This reduces the overall axial length of the device thereby facilitating use of the device in increasingly smaller engine compartments. 
       FIG.  2    is an exploded view of  FIG.  1   . End  41  of torsion spring  40  is welded to carrier  51 . Inner race  31  of bearing  30  further comprises hub  70 . Dust cover  80  covers an end of the device. 
     Hub  70  comprises both the inner race of bearing  30  as well as an extension of shaft  10 . Hub  70  is press fit on one end  12  of shaft  10 . 
       FIG.  3   a    is a perspective view of a weld detail. Weld bead  142  attaches end  41  to carrier  51 . The weld may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Bead  142  extends through angle α of approximately 70 degrees in circumference, however, the length of the weld bead may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  3   b    is a front view of a weld detail. 
       FIG.  4   a    is a perspective view of a weld detail. Weld bead  44  attaches end  43  of torsion spring  40  to outer race  62 . The weld may be accomplished using methods known in the welding arts such as MIG, SMAW, TIG and laser welding. Bead  44  extends through an angle α of approximately 70 degrees in circumference. However, the length of weld bead  44  may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  4   b    is a front view of a weld detail. 
       FIG.  5    is a perspective view of a weld detail. Flange  61  is welded to pulley  20  and to bearing  60 . Weld bead  63  welds flange  61  to pulley  20 . Weld bead  64  welds flange  61  to outer race  62 . Weld  63  and weld  64  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Weld bead  63  and weld bead  64  each extend around the full circumference of flange  61 . 
       FIG.  6    is a cross-section view of a second embodiment. In this embodiment the inner race of ball bearing  65  is an integral part of shaft  10 . 
     “L” shaped flange  66  is press fit onto the outer race of bearing  65 . 
       FIG.  7    is an exploded view of  FIG.  6   . 
       FIG.  8   a    is a perspective view of a weld detail. Weld bead  142  attaches end  41  to carrier  51 . Weld  142  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Bead  142  extends through an angle α of approximately 70 degrees in circumference, however, the length of the weld bead may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  8   b    is a front view of a weld detail. 
       FIG.  9   a    is a perspective view of a weld detail. Weld bead  45  attaches end  43  to outer flange  66 . The weld may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Weld  45  extends through approximately 70 degrees in circumference. However, the length of the weld bead may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  9   b    is a front view of a weld detail. 
       FIG.  10    is a perspective of a weld detail. Flange  66  is welded to pulley  20 . Weld bead  165  welds flange  66  to pulley  20 . Weld  165  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Weld  165  extends around the full circumference of flange  66 . 
       FIG.  11    is a cross-section view of a third embodiment. In this embodiment bearing assembly  600  is threadably engaged with shaft  100 . Torsion spring  400  is engaged between flange  68  and carrier  51 . Pulley  21  is journalled to shaft  100  through bearing  30 . 
     Bearing assembly  600  is threaded into shaft  100 . Bearing assembly  600  comprises a bearing  601 , carrier  602  and dust cover  603 . Bearing  601  is press fit onto carrier  602 . One end of carrier  602  comprises threaded projection  604 . Threaded projection  604  engages threaded receiver  101  of shaft  100 . A tool such as a ratchet (not shown) can engage portion  605  to screw bearing assembly  600  into shaft  100 . Pulley  21  is journalled to shaft  100  on bearing  601 . 
       FIG.  12    is a perspective of a weld detail. Weld bead  420  attaches end  410  to carrier  51 . Weld  420  may be accomplished using methods known in the welding arts such as MIG, SMAW, TIG and laser welding. Weld  420  extends through approximately 70 degrees in circumference. However, the length of the weld bead may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  13    is a perspective of a weld detail. Weld bead  440  attaches end  430  to pulley  21 . Weld  440  may be accomplished using methods known in the welding arts such as MIG, SMAW, TIG and laser welding. Weld  440  extends through approximately 70 degrees in circumference, however, the length of the weld bead may vary between approximately 45 degrees and approximately 90 degrees depending on operational requirements. 
       FIG.  14    is a perspective of a weld detail. Flange  68  is welded to pulley  21 . Weld bead  69  welds flange  68  to pulley  21 . Weld  69  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Weld  69  extends around the full circumference of flange  68 . 
       FIG.  15    is a cross-section view of the third embodiment. There is a clearance fit between bearing  601  and flange  68  which allows bearing  601  to slide into flange  68  during assembly. 
     Welded assembly of the components torsion spring  400 , carrier  51 , flange  68  and pulley  21  are as described elsewhere in this specification for the other embodiments. 
       FIG.  16 A  is an exploded view of  FIG.  15   .  FIG.  16 B  is a detail of  FIG.  16 A . Bearing assembly  600  comprises bearing  601 , dust cover  603  and threaded projection  604 . Threaded projection  604  threads into shaft  100 , see  FIG.  16   . 
       FIG.  17    is a detail of  FIG.  16 A . Shaft  100  comprises a threaded inner surface  102 . When connected to an installation tool, receiving portion  103  temporarily holds shaft  100  as shaft  100  is screwed onto an alternator shaft (not shown) via threaded portion  102 . 
       FIG.  18    is a cross-section view of a fourth embodiment. This embodiment comprises shaft  110 , pulley  22 , ball bearing  30 , torsion spring  500 , one-way clutch wrap spring  550  and bearing assembly  700 . Ball bearing  30  may also comprise a needle bearing. 
     Pulley  22  is journalled to shaft  110  through bearing  30  and bearing  701 . Torsion spring  500  is engaged between shaft  110  and one-way clutch wrap spring  550 . 
     Torsion spring  500  is welded to a shoulder  112  on shaft  110 . The other end of torsion spring  500  is welded to wrap spring  550 . 
     In operation torsion spring  500  is loaded in the winding direction. This causes spring  500  to radially contract under load. Wrap spring  550  radially expands under load, thereby pressing into inner surface  23 . 
     An end  501  of torsion spring  500  is welded to an end of wrap spring  550 . The weld may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. 
       FIG.  19    is a cross-section view of the embodiment in  FIG.  18   . Bearing assembly  700  comprises a bearing  701  and carrier  702 . Portion  703  comprises a dust cover. Bearing  701  is press fit onto carrier  702 . One end of carrier  702  comprises threaded projection  704 . Threaded projection  704  engages threaded receiver  111  of shaft  110 . A tool such as a ratchet (not shown) can engage portion  705  to screw bearing assembly  700  into shaft  110 . 
       FIG.  20    is a detail of  FIG.  18   . Shaft  110  comprises a shoulder  112 . Shoulder  112  projects radially from shaft  110 . An end of torsion spring  500  is welded to shoulder  112 . The weld may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. Inner surface  111  is threaded to receive threaded projection  704 . 
       FIG.  21    is a perspective view. End  552  of wrap spring  550  engages an end  501  of spring  500 . In an overtorque condition end  502  presses against end  551  thereby causing wrap spring to wind up. As wrap spring winds it contracts inward in the radial direction. This causes wrap spring  550  to progressively loose frictional engagement with surface  23 , thereby releasing shaft  110  to rotate with respect to pulley  22 . This relieves the overtorque condition thereby preventing damage to the device. 
       FIG.  22    is a perspective view of a weld detail. End  501  of spring  500  is welded to end  552  of wrap spring  550  with a weld bead  504 . Weld  504  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. 
       FIG.  23    is a perspective view of a weld detail. End  502  of spring  500  is welded to shoulder  112  with a weld bead  503 . Weld  503  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. 
       FIG.  24    is a perspective view of a weld detail. 
     Flange  680  is welded to pulley  22  with a weld bead  681 . Weld  681  may be accomplished using methods known in the welding arts such as MIG, SMAW, GMAW, TIG and laser welding. 
       FIG.  25    is an exploded view of  FIG.  18   . Outer surface  1552  frictionally engages surface  23 . This prevents rotation of pulley  22  with respect to shaft  110 . 
     In each of the foregoing embodiments, one or more of the described welds can be replaced by a suitable adhesive system. For example, structural adhesive pastes and epoxies, all for metal to metal bonding can be used. Each of these categories is known in the aircraft and aerospace industries, for example, such products are available from 3M®, Permabond and Masterbond and others. Friction welding is also available for use on the welded connections between the shaft and torsion spring. 
     An isolating decoupler comprising a shaft having a threaded inner surface, a pulley journalled to the shaft on a bearing assembly, the bearing assembly comprising a bearing carrier and a bearing, the bearing carrier threadably engaged with the threaded inner surface, the bearing carrier having a receiving portion for engaging a tool, a one-way clutch engaged with the shaft, a torsion spring engaged between the one-way clutch and the pulley, and the torsion spring having an end welded to the one-way clutch and having another end welded to the pulley. 
     An isolating decoupler comprising a shaft, a pulley journalled to the shaft on at least one bearing, a one-way clutch engaged with the shaft, a torsion spring engaged between the one-way clutch and the pulley, the shaft configured as an inner race of the at least one bearing, and at least one end of the torsion spring is connected by welding to either the one-way clutch or the pulley. 
     Although forms of the invention have been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein. U less otherwise specifically noted, components depicted in the drawings are not drawn to scale. Further, it is not intended that any of the appended claims or claim elements invoke 35 U.S.C. § 112(f) unless the words “means for” or ‘step for’ are explicitly used in the particular claim. The present disclosure should in no way be limited to the exemplary embodiments or numerical dimensions illustrated in the drawings and described herein.