Patent Publication Number: US-7588233-B2

Title: Winch assembly including clutch mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/866,525, filed on Nov. 20, 2006. The disclosure of the above application is incorporated herein by reference. 

   FIELD 
   The present disclosure relates to power devices, and more specifically to winch assemblies including clutch mechanisms. 
   BACKGROUND AND SUMMARY 
   The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
   Winch assemblies may include a variety of parts to provide a freespool condition for the winch including various brake assemblies and clutch mechanisms. The existing brake assemblies and clutch mechanisms may include numerous parts that add cost to the assembly and provide for a complicated assembly process. 
   Accordingly, a winch assembly may include a housing member, a drum, a drive shaft, a gear train, a coupling member, and a clutch assembly. The drum may be rotatably coupled to the housing member and the drive shaft may extend through the drum and into the housing member. A first end of the shaft may be fixed for rotation with a drive input and axially displaceable relative to the drive input. The gear train may be located within the housing member and in a driven engagement with the drive shaft. The coupling member may be axially fixed to the drive shaft. The clutch assembly may include a clutch knob rotatably coupled to the housing member for rotation in first and second rotary directions. The clutch knob may include an axially extending ramped surface that axially displaces the drive shaft in a first axial direction when the clutch knob is rotated in the first rotary direction and rotationally couples the drum to the gear train through engagement with the coupling member. The ramped surface axially displaces the drive shaft in a second axial direction generally opposite the first axial direction when the clutch knob is rotated in the second rotary direction and disengages the drum from rotational engagement with the gear train. 
   An alternate winch assembly may include a housing member, a drum, a drive shaft, a gear train, a coupling member, and a clutch assembly. The drum may be rotatably coupled to the housing member and the drive shaft may extend through the drum and into the housing member. A first end of the shaft may be fixed for rotation with a drive input and axially displaceable relative to the drive input. The gear train may be located within the housing member and in a driven engagement with the drive shaft. The coupling member may be axially movable for engaging the drum with the gear train. The clutch assembly may include a clutch knob rotatably coupled to the housing member for rotation in first and second rotary directions. The clutch knob may include an axially extending ramped surface that axially displaces the coupling member in a first axial direction when the clutch knob is rotated in the first rotary direction and rotationally couples the drum to the gear train. The ramped surface may axially displace the coupling member in a second axial direction generally opposite the first axial direction when the clutch knob is rotated in the second rotary direction and may disengage the drum from rotational engagement with the gear train. 
   Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples 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 illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
       FIG. 1  is a perspective view of a winch assembly according to the present disclosure; 
       FIG. 2  is an exploded perspective view of a gear housing assembly shown in  FIG. 1 ; 
       FIG. 3  is a sectional view of the winch assembly of  FIG. 1 ; 
       FIG. 4  is a fragmentary sectional view of the winch assembly of  FIG. 1 ; 
       FIG. 5  is a sectional view of an alternate winch assembly according to the present disclosure; 
       FIG. 6  is an additional sectional view of the winch assembly of  FIG. 5 ; 
       FIG. 7  is an exploded perspective view of a gear housing assembly shown in  FIG. 5 ; 
       FIG. 8  is a perspective view of a gear housing member of the winch assembly of  FIG. 5 ; 
       FIG. 9  is a perspective view of a thrust cap of the winch assembly of  FIG. 5 ; and 
       FIG. 10  is an end plan view of the gear assembly housing of  FIG. 5 . 
   

   DETAILED DESCRIPTION 
   The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
   As seen in  FIG. 1 , a winch  10  may include a motor assembly  12 , a drum  14 , and a gear housing assembly  16 . Drum  14  may be rotatably disposed between and driven by motor assembly  12  and gear housing assembly  16 , as discussed below. 
   With additional reference to  FIG. 3 , motor assembly  12  may be a reversible electric motor having an output shaft  18 . Gear housing assembly  16  may be longitudinally offset from motor assembly  12  and may house a gear train  20  therein. Drum  14  may be disposed between and bearingly supported at opposite ends by motor assembly  12  and gear housing assembly  16 . A drive shaft  22  may extend through drum  14  and may be coupled to output shaft  18  of motor assembly  12  at a first end. The coupling between output shaft  18  and the first end of the drive shaft  22  may include a cam mechanism  26 . A second end of drive shaft  22  may be engaged with gear train  20 , as discussed below. 
   With additional reference to  FIGS. 2 and 4 , gear housing assembly  16  may include a housing member  28  generally fixed against rotation, gear train  20 , and a clutch assembly  32 . Housing member  28  may include first and second inner surfaces  34 ,  36  having gear teeth formed thereon axially offset from one another, forming first and second fixed ring gears  38 ,  40 . A series of apertures  42 ,  44  may extend axially into housing member  28  past first fixed ring gear  38  and opening into an intermediate region between first and second fixed ring gears  38 ,  40 . 
   With particular reference to  FIGS. 3 and 4 , gear train  20  may include first, second, and third stage planetary gear drive assemblies  46 ,  48 ,  50 . First stage planetary gear drive assembly  46  may include a sun gear  52  non-rotatably fixed to drive shaft  22  and a planetary gear assembly  54  having three pinion gears  56  rotatably mounted to a carrier plate  58  and meshingly engaged with sun gear  52  and first fixed ring gear  38 . 
   Second stage planetary gear drive assembly  48  may include a sun gear  60  rotatably mounted on drive shaft  22 , which passes through sun gear  60 , a planetary gear assembly  62  having three pinion gears  64  rotatably mounted to a carrier plate  66 , and a ring gear  68 . Ring gear  68  may be located between first and second fixed ring gears  38 ,  40  and may be rotatably mounted to housing member  28 . As best shown in  FIG. 2 , ring gear  68  may include a cylindrical body having a generally smooth outer surface  70  and an inner surface  72  having gear teeth  74  extending therefrom. Ring gear  68  may also include a series of recesses  76  extending axially into an end surface  78  thereof for selective engagement with clutch assembly  32 , discussed below. Pinion gears  64  may be meshingly engaged with gear teeth  74  and meshingly engaged with sun gear  60 . Sun gear  60  may be fixed for rotation with carrier plate  58 . 
   Third stage planetary gear drive assembly  50  may include a sun gear  80  rotatably mounted on drive shaft  22 , which passes through sun gear  80 , and a planetary gear assembly  82  having three pinion gears  84  rotatably mounted to a carrier plate  86  and meshingly engaged with sun gear  80  and second fixed ring gear  40 . Sun gear  80  may be fixed for rotation with carrier plate  66  of second stage planetary gear drive assembly  48 . 
   A coupling  88  may be rotatably mounted to drive shaft  22 , which passes through coupling  88 , to carrier plate  86  of third stage planetary gear drive assembly  50  for rotation therewith. Coupling  88  may be drivingly engaged with drum  14 . More specifically, drum  14  may include an inner surface  90  having splines  92  extending therefrom and meshingly engaged with coupling  88 . 
   With reference to  FIGS. 2-4 , clutch assembly  32  may include a clutch cap  94 , a clutch dial  96 , a clutch bar  98 , and first and second clutch pins  100 ,  102 . Clutch cap  94  may be non-rotatably fixed to an end of housing member  28 . With particular reference to  FIG. 2 , clutch cap  94  may include a generally planar body  104  having a central hub portion  106  extending axially outwardly therefrom. Clutch cap body  104  may include first and second apertures  108 ,  110  and first and second ramped portions  112 ,  114 . First and second apertures  108 ,  110  may extend through a circumferential portion of clutch cap body  104  and may be aligned with apertures  42 ,  44  in housing member  28 . First and second ramped portions  112 ,  114  may be located adjacent first and second apertures  108 ,  110 , although other locations could be utilized. 
   Clutch dial  96  may be rotatably mounted to housing member  28  and may include a central aperture  116  located on central hub portion  106  of clutch cap  94  and rotatable thereabout. Clutch bar  98  may be fixed for rotation with clutch dial  96 . Clutch bar  98  may include a central body portion  118  having arms  120 ,  122  extending radially outwardly therefrom. Arms  120 ,  122  may each include radially outer arcuate portions  124 ,  126  having circumferentially extending channels  128 ,  130  generally aligned with clutch cap apertures  108 ,  110  and housing member apertures  42 ,  44 . Channels  128 ,  130  may each include a first portion  132 ,  134  having a generally circular opening and a second portion  136 ,  138  forming the remainder of the channels  128 ,  130 . Second portions  136 ,  138  may have a width that is less than the diameter of first portions  132 ,  134  for retention of clutch pins  100 ,  102  therein, as discussed below. Central body portion  118  may include a centrally disposed aperture  140  disposed around clutch cap hub portion  106  for rotation thereabout with clutch dial  96 . 
   Clutch pins  100 ,  102  may be generally similar to one another, therefore only clutch pin  100  will be described in detail with the understanding that the description applies equally to clutch pin  102 . Clutch pin  100  includes an elongate body portion  142 , a neck  144 , and a head  146 . Neck  144  may have a diameter that is less than a diameter of both body portion  142  and head  146 . Body portion  142  and head  146  may have diameters that are less than the diameter of first portion  132  of clutch bar channel  128  but greater than the width of second portion  136  of clutch bar channel  128 . The relationship between the diameters of clutch pin  100  and clutch bar channel  128  may allow clutch bar  98  to be installed after clutch pin  100  is already assembled in clutch cap  94  and housing member  28 . More specifically, clutch bar channel first portion  132  may be placed over head  146  to neck  144  and rotated such that clutch pin  100  is axially engaged with clutch bar channel second portion  136  through the relationship between the diameters thereof. 
   Clutch pins  100 ,  102  may be displaced between an engaged position with ring gear  68  (seen in  FIG. 3 ) and a disengaged position (seen in  FIG. 4 ). Clutch pins  100 ,  102  may be normally biased into the engaged position by clutch bar  98 . Clutch bar  98  may act as a leaf spring, urging clutch pins  100 ,  102  into recesses  76  of ring gear  68 , rotationally fixing ring gear  68  relative to housing member  28 . Since housing member  28  is rotationally fixed, ring gear  68  is therefore also rotationally fixed when clutch pins  100 ,  102  are in the engaged position. 
   Rotation of clutch dial  96  may move clutch pins  100 ,  102  into the disengaged position shown in  FIG. 4 . More specifically, rotation of clutch dial  96  causes rotation of clutch bar  98  therewith. As clutch bar  98  is rotated, arcuate portions  124 ,  126  travel along ramped portions  112 ,  114  of clutch cap  94 . As clutch bar arcuate portions  124 ,  126  travel along ramped portions  112 ,  114 , they are translated axially outwardly relative to housing member  28 . As clutch bar arcuate portions  124 ,  126  are axially translated, clutch pins  100 ,  102  may be axially translated as well due to the engagement between clutch pins  100 ,  102  and clutch bar channels  128 ,  130  discussed above. When axially translated, clutch pins  100 ,  102  are removed from recesses  76  in ring gear  68 , allowing ring gear to rotate freely relative to housing member  28 . 
   Operation of winch  10  will now generally be discussed. Operation will be discussed without reference to a rotational direction with the understanding that motor assembly  12  may rotate drive shaft  22  in first and second directions. The description of the operation of winch  10  is merely intended to illustrate the function of clutch assembly  32 . 
   As drive shaft  22  is rotated by motor assembly  12 , sun gear  52  is caused to rotate therewith. Rotation of sun gear  52  may be translated to pinion gears  56  of first stage planetary gear drive assembly  46 . Rotation of pinion gears  56  may cause rotation of carrier plate  58  relative to housing member  28  due to the meshed engagement between pinion gears  56  and first fixed ring gear  38 . Rotation of carrier plate  58  may cause rotation of sun gear  60  of second stage planetary gear drive assembly  48 . 
   Rotation of sun gear  60  may cause a corresponding rotation of pinion gears  64 . Rotation of pinion gears  64  may or may not cause rotation of carrier plate  66 , depending on whether clutch pins  100 ,  102  are in an engaged or a disengaged position. If clutch pins  100 ,  102  are in a disengaged position, seen in  FIG. 4 , ring gear  68  may rotate relative to housing member  28 , causing a freespool condition where second stage planetary gear drive assembly  48  is disengaged. More specifically, pinion gears  64  may engage gear teeth  74  of ring gear  68 , causing ring gear  68  to rotate relative to housing member  28 . As a result, when in this disengaged position, drive torque is not transmitted to third stage planetary gear drive assembly  50 , and therefore drum  14  is not driven. 
   If clutch pins  100 ,  102  are in an engaged position, seen in  FIG. 3 , ring gear  68  may be rotationally fixed relative to housing member  28 . When ring gear  68  is rotationally fixed relative to housing member  28 , rotation of pinion gears  64  by sun gear  60  may cause pinion gears  64  to travel along inner surface  72  of ring gear  68 , resulting in carrier plate  66  rotating relative to housing member  28 . Rotation of carrier plate  66  may cause rotation of sun gear  80  of third stage planetary gear drive assembly  50 . 
   Rotation of sun gear  80  may cause a corresponding rotation of pinion gears  84 . Rotation of pinion gears  84  may cause rotation of carrier plate  86  relative to housing member  28  due to the meshed engagement between pinion gears  84  and second fixed ring gear  40 . Rotation of carrier plate  86  may cause rotation of coupling  88  due to a fixed connection therebetween. Rotation of coupling  88  may be translated to drum  14  due to the meshed engagement between drum spline teeth  92  and coupling  88 . When in the freespool condition discussed above, drum  14  may rotate freely in a direction opposite the direction of rotation when engaged with coupling  88 . 
   As seen in  FIGS. 5-10 , an alternate winch  210  may include a motor assembly  212 , a drum  214 , and a gear housing assembly  216 . Drum  214  may be rotatably disposed between and driven by motor assembly  212  and gear housing assembly  216 , as discussed below. 
   With reference to  FIGS. 5 and 6 , motor assembly  212  may be a reversible electric motor having an output shaft  218 . Gear housing assembly  216  may be longitudinally offset from motor assembly  212  and may house a gear train  220  therein. Drum  214  may be disposed between and bearingly supported at opposite ends by motor assembly  212  and gear housing  216 . A drive shaft  222  may extend through drum  214  and may be coupled to output shaft  218  of motor assembly  212  at a first end. A drive input member  223  can be attached to output shaft  218  and can allow axial movement of shaft  222  while maintaining a driving connection therewith. A second end of drive shaft  222  may be engaged with gear train  220 , as discussed below. 
   Gear housing assembly  216  may include a housing member  228 , generally fixed against rotation, gear train  220 , and a clutch assembly  232 . Housing member  228  may include first and second inner surfaces  234 ,  236  having gear teeth formed thereon axially offset from one another, forming first and second ring gears  238 ,  240 . 
   With particular reference to  FIGS. 5 and 6 , gear train  220  may include first, second, and third stage planetary gear drive assemblies  246 ,  248 ,  250 . First planetary gear drive assembly  246  may include a sun gear  252  non-rotatably fixed to drive shaft  222  and slidable thereon and a planetary gear assembly  254  having three pinion gears  256  rotatably mounted to a carrier plate  258  and meshingly engaged with sun gear  252  and first ring gear  238 . 
   Second stage planetary gear drive assembly  248  may include a sun gear  260  rotatably mounted on drive shaft  222 , a planetary gear assembly  262  having three pinion gears  264  rotatably mounted to a carrier plate  266  and meshingly engaged with sun gear  260  and first ring gear  238 . Sun gear  260  may be fixed for rotation with carrier plate  258 . 
   Third stage planetary gear drive assembly  250  may include a sun gear  280  rotatably mounted on drive shaft  222  and a planetary gear assembly  282  having three pinion gears  284  rotatably mounted to a carrier plate  286  and meshingly engaged with sun gear  280  and second fixed ring gear  240 . Sun gear  280  may be fixed for rotation with carrier plate  266 . Carrier plate  286  may have a coupling member  287  fixed thereto having radially inwardly extending splines  289 . 
   A clutch coupler  288  may be rotatably mounted to drive shaft  222 . Clutch coupler  288  may abut an axially fixed stop member  291  on shaft  222 . Clutch coupler  288  may be drivingly engaged with drum  214 . More specifically, drum  214  may include an inner surface  290  having spline teeth  292  extending therefrom and meshingly engaged with clutch coupler  288 . Clutch coupler  288  may provide selective engagement between drum  214  and gear train  220 , as discussed below. 
   With additional reference to  FIG. 7 , clutch assembly  232  may include a clutch knob  294 , a cam follower  296 , a disengagement spring  298 , a thrust cap  300 , and an engagement spring  302 . Clutch knob  294 , cam follower  296 , disengagement spring  298 , and thrust cap  300  may be contained within housing member  228  without the use of fasteners, as will be described herein. With particular reference to  FIGS. 8 and 10 , housing member  228  may include an opening  304  at an end  306  thereof. End  306  may include a lip  308  extending radially inwardly around a circumference of opening  304 . Lip  308  may include a series of recesses  310  therein. End  306  may further include a series of protrusions  312  extending radially inwardly from opening  304  and beyond lip  308 . Protrusions  312  may be located adjacent recesses  310 . 
   Clutch knob  294  may include a series of axially inwardly extending protrusions  314  and a series of cam features  316  disposed about an inner circumference thereof. Protrusions  314  may include first and second portions  318 ,  320 . First portion  318  may be located axially inward of second portion  320  and may have a lesser radial extent than second portion  320 . Cam features  316  may include a series of ramped surfaces  322 . 
   Cam follower  296  may be disposed within clutch knob  294  and may include a main body portion  324  and a series of arms  326  extending radially outwardly therefrom. Main body portion  324  may be located radially within cam features  316  and arms  326  may extend radially outwardly relative to cam features  316 . Arms  326  may include a recess  328  housing protrusions  312  therein, slidably coupling cam follower  296  to housing  228 . An axially outer end  330  of arm  326  may abut ramped surface  322 , as discussed below. Main body portion  324  may include an aperture  332  therethrough. A series of guide members  334  may extend radially inwardly relative aperture  332 . 
   During assembly, protrusions  314  may be inserted into recesses  310  in housing  228 . More specifically, second portions  320  of protrusions  314  may be inserted axially beyond lip  308 . Clutch knob  294  may then be rotated relative to housing  228 , axially retaining and rotatably coupling clutch knob  294  relative to housing  228 . Clutch knob  294  may be locked into engagement with housing  228  by cam follower  296 . More specifically, once arms  326  are engaged with protrusions  312 , recesses  310  may be obstructed such that clutch knob  294  may not be removed from housing  228 . 
   With particular reference to  FIG. 9 , thrust cap  300  may include first and second portions  336 ,  338 . First portion  336  may be disc-shaped having second portion  338  extending therefrom. Disengagement spring  298  may be disposed between cam follower  296  and first portion  336  of thrust cap  300  (seen in  FIGS. 5 and 6 ). Cam follower  296  may include recesses  297  for engagement with snap features  301  of thrust cap  300 . Engagement between snap features  301  and recesses  297  couples thrust cap  300  to cam follower  296 , allowing a range of axial displacement therebetween and capturing disengagement spring  298  therebetween. More specifically, spring  298  may be placed over second portion  338  before coupling thrust cap  300  to cam follower  296 . Second portion  338  may have an outer diameter less than an outer diameter first portion  336  and may form a seat for disengagement spring  298 . An aperture  340  may extend through first portion  336  and partially into second portion  338 . As seen in  FIGS. 5 and 6 , shaft  222  may extend into aperture  340 . An outer surface of second portion  338  may include axially extending recesses  342  therein. Recesses  342  may receive guide member  334  therein. 
   Operation of winch  210  will now generally be discussed. Operation will be discussed without reference to a rotational direction with the understanding that motor assembly  212  may rotate drive shaft  222  in first and second directions. The description of the operation of winch  210  is merely intended to illustrate the function of clutch assembly  232 . 
   As drive shaft  222  is rotated by motor assembly  212 , sun gear  252  is caused to rotate therewith. Rotation of sun gear  252  may drive rotation of planetary gear assembly  254 . Planetary gear assembly  254  may drive rotation of second planetary gear drive assembly  248  which may drive rotation of third planetary gear drive assembly  250 . Rotation of third planetary gear drive assembly  250  may include rotation of carrier plate  286  and therefore coupling member  287 . Drum  214  may be selectively driven by rotation of coupling member  287  when engaged with clutch coupler  288 , as discussed below. 
   More specifically, clutch coupler  288  may provide selective engagement with coupling member splines  289  when in an engaged position. As seen in  FIG. 5 , engagement spring  302  abuts drum  214  and provides an axial force against clutch coupler  288 , biasing clutch coupler  288 , and therefore drive shaft  222 , axially outwardly from drum  214  and into engagement with coupling member  287 . When in the engaged position, clutch coupler  288  is engaged with both drum  214  and coupling member  287 , resulting in rotation of carrier plate  286  being translated to drum  214 . 
   Engagement spring  302  may have a biasing force significantly greater than the force applied by disengagement spring  298 , resulting in an engagement of drum  214  during normal operation. When disengagement of drum  214  is desired, clutch knob  294  may be rotated. Rotation of clutch knob  294  may cause arms  326  of cam follower  296  to ride along ramped surface  322 , resulting in axial displacement of cam follower  296  (seen in  FIG. 6 ) and compression of disengagement spring  298 . 
   Compression of disengagement spring  298  may result in an increased spring force applied against thrust cap  300  and therefore shaft  222 . More specifically, the increased spring force of disengagement spring  298  may be greater than the spring force applied by engagement spring  302 , resulting in axial displacement of shaft  222  relative to drive input member  223 . Clutch coupler  288  may therefore be displaced axially as well, due to the engagement between clutch coupler  288  and stop member  291 , resulting in the disengagement of clutch coupler  288  from coupling member  287 . As such, drum  214  may be disengaged from gear train  220 .