Patent Publication Number: US-2022221011-A1

Title: Clutch hub assembly with improved oil flow

Description:
BACKGROUND 
     The following description relates generally to a clutch hub, a clutch hub assembly, and an automatic transmission having a clutch hub assembly. 
     A step-ratio planetary style automatic transmission includes a plurality of multiple-disc wet-clutch packs. The wet-clutch packs can be operated to hold and release elements of a planetary gear set and mechanical clutches within the transmission to create, for example, forward reduction ratios, forward overdrive ratios, neutral and reverse reduction ratios and the like. 
     A conventional multiple-disc wet-clutch pack includes one or more internally toothed friction clutch plates and one or more externally toothed steel separator clutch discs. The friction clutch plates are typically formed as a steel core with bonded friction surfaces thereon. The separator clutch discs may be disposed between adjacent pairs of the friction clutch plates. 
     The multiple-disc wet-clutch pack has four basic functional states: (1) a fully released or “open” state in which the internally toothed friction clutch plates and the externally toothed steel separator clutch discs can move or rotate at different speeds relative to each other; (2) a fully applied or “closed” state in which the internally toothed friction clutch plates and the externally toothed steel separator clutch discs are locked together and move or rotate in unison; (3) a first transition state in which the clutch pack transitions from the released state to the applied state; and (4) a second transition state in which the clutch pack transitions from the applied state to the released state. 
     A conventional multiple-disc wet-clutch pack may fail when the friction clutch is damaged by heat. The most significant source of heat typically occurs in the first transition state when the clutch pack transitions from the released state to the applied state. Another significant source of heat can result from viscous shear in the fully released state and in the second transition state in which the clutch pack transitions from the applied state to the released state. 
     Accordingly, many automatic transmission multiple-disc wet-clutch packs are designed to direct oil to flow across the clutch plates to lubricate and cool the clutch plates. The oil may be provided from a pressurized source and is typically carried through and across clutch plate faces by centrifugal forces from rotating transmission components. 
     Such conventional automatic transmissions include the General Motors Hydra-Matic 6 Speed rear wheel drive transmission with the 6L45/6L50/6L80/6L90 designations. The General Motors Hydra-Matic 6 Speed rear wheel drive transmissions are considered Original Equipment, or “OE,” transmissions, which are installed in vehicles by the manufacturer during original manufacturing of the vehicles. The General Motors Hydra-Matic 6 Speed rear wheel drive transmissions, and original components of the transmissions, may be prefaced herein using “OE” terminology. In the OE transmissions, a 4-5-6 clutch pack may have a relatively high failure rate and may experience high incidences of heat damage. 
     The OE transmissions have six forward ratios (speeds) and one reverse ratio. The 4-5-6 clutch pack is in the fully applied state when the transmission is the 4 th , 5 th  and 6 th  gear ranges. The 4-5-6 clutch pack is in the fully released state when the transmission is in the 1 st , 2 nd  and 3 rd  gear ranges. 
       FIGS. 1 and 2  illustrate examples of an OE 4-5-6 clutch hub assembly  110  of an OE automatic transmission. Referring to  FIGS. 1 and 2 , the OE 4-5-6 clutch hub assembly  110  includes an OE clutch hub  120 , an OE hub shaft  130 , an OE clutch dampener  140 , an OE apply plate  150  and an OE retainer ring  160 . 
     The OE clutch hub  120  has an interior portion  122  ( FIG. 2 ) and a plurality of oil holes  124  extending between the interior portion  122  and a splined outer surface  126  so that oil can flow between the interior portion  122  and an exterior of the OE clutch hub  120 . The OE clutch hub  120  is connected to the OE hub shaft  130  so that the OE clutch hub  120  and the OE hub shaft  130  rotate together. 
     The OE clutch dampener  140  is formed as an annular body having a first axial face  142  and a second axial face  144 . The first axial face  142  includes a bonded friction material and has a plurality of grooves  146 . The grooves  146  are circumferentially spaced and extend in a radial direction. The grooves  146  have a depth extending in an axial direction. The grooves  146  are configured to allow radially outward oil flow. The second axial face  144  includes a bonded friction material and forms a substantially flush and/or planar contact surface (i.e., non-grooved). 
     The OE apply plate  150  has a toothed outer circumference  152 , a first axial face  154  facing the second axial face  144  of the clutch dampener  140  and a second axial face  156  facing away from the first axial face  154 . 
     The OE retainer ring  160  is a waved spring that contacts the axial face  156  of the OE apply plate  150  and preloads the OE apply plate  150  and the OE clutch dampener  140  into the interior portion  122  of the OE clutch hub  120 . The preload from the OE retaining ring  160  creates sealing surface between the OE apply plate  150  and the OE clutch dampener  140  at the second axial (non-grooved) face  144  of the OE clutch dampener  140  and the first axial face  154  of the OE apply plate  150 . The preload also creates a partial sealing surface between a portion of the OE clutch hub  120  and the first axial face  142  of the clutch dampener  140 , with oil flow through the grooves  146 . 
       FIG. 3  is an exploded view showing the OE 4-5-6 clutch hub assembly  110 , an OE 4-5-6 housing assembly  210  and an OE 1-2-3 clutch hub assembly  310  of the OE automatic transmission. A housing shaft thrust bearing  212  is disposed between the OE 4-5-6 clutch hub assembly  110  and the OE housing assembly  210 . A clutch hub bearing  312  is disposed between the OE 4-5-6 clutch hub assembly  110  and the OE 1-2-3 clutch hub assembly  310 . 
       FIG. 4  is an exploded view of the OE housing assembly  210  of  FIG. 3 . The OE 4-5-6 housing assembly  210  includes an OE housing body  220  and an OE housing shaft  230 . An OE clutch piston  240 , an OE clutch spring  250  and an OE clutch piston dam  260  are disposed along the OE housing shaft  230  within the OE housing body  220 . A plurality of OE friction clutch plates  270  and a plurality of OE separator clutch discs  280  are positioned in the housing body  220  as well. The OE friction clutch plates  270  and the OE separator clutch discs  280  may form an OE multiple disc wet-clutch pack. 
       FIG. 5  is a diagram illustrating an example of the OE automatic transmission  510 . The OE automatic transmission  510  includes the OE 4-5-6 clutch hub assembly  110  described above. Lubricating and cooling oil feeds in the OE automatic transmission  510  are shown as shaded and/or dotted paths. A rear oil feed  512  extends generally along a central axis and supplies oil to the OE automatic transmission  510  from a pressurized source. An OE oil feed  514  extends between the OE hub shaft  130  of the OE clutch hub assembly  110  and an OE hub shaft  330  of the OE 1-2-3 clutch hub assembly  310  ( FIG. 3 ). A first oil feed  516  receives oil from the rear oil feed  512  and extends generally between a rear portion of the OE housing shaft  230  and a front portion of the OE hub shaft  130 . The OE automatic transmission has an axially forward end indicated generally at ‘F’ and an axially rearward end indicated generally at ‘R.’ Accordingly, an axially forward direction extends generally toward the axially forward end ‘F’ and an axially rearward direction extends generally toward the axially rearward end ‘R.’ 
       FIG. 6  is a diagram illustrating an enlarged portion of the OE automatic transmission  510  of  FIG. 5 , including the portion generally shown at DETAIL A. An OE oil flow path OEP for lubricating and cooling oil for the OE 4-5-6 clutch hub assembly  110  is indicated in  FIG. 6  by arrows and dotted lines. The OE oil flow path OEP receives oil from the OE oil feed  512  between the OE hub shaft  130  of the OE 4-5-6 clutch hub assembly  110  and the OE hub shaft  330  of the OE 1-2-3 clutch hub assembly  310 . 
     The OE oil flow path OEP extends through the clutch hub thrust bearing  312  and into the interior portion  122  of the OE clutch hub  120  through a rearward facing, open side of the OE clutch hub  120 . The OE oil flow path OEP extends around a radial inner side and the first axial face  142  of the OE clutch dampener  140  to an outer radial side of the OE clutch dampener  140 . At the first axial face  142 , the OE oil flow path extends through the grooves  146  ( FIG. 1 ), between the OE clutch dampener  140  and the OE clutch hub  120 . The OE oil flow path OEP then extends radially outward through the oil holes  124  of the OE clutch hub  120 . 
     Accordingly, oil migrates along the OE oil flow path OEP through the clutch hub thrust bearing  312  and is caught by the OE apply plate  150 . The oil is blocked by the second axial face  144  of the OE clutch dampener  140  and flows between OE clutch dampener  140  and the OE clutch hub  120  from an inner radial side of the OE clutch dampener  140 , around the first axial face  142  via the grooves  146  to the outer axial side of the OE clutch dampener  140 . The oil then flows through the oil holes  124  of the OE clutch hub  120  to exit the interior portion  122 . In this manner, the oil may be supplied to the OE friction clutch plates  270  and the OE separator clutch discs  280  (i.e., the clutch pack). 
     However, in the OE automatic transmission  510 , the lubricating and cooling oil may not be supplied to the OE 4-5-6 friction clutch plates  270  and the OE 4-5-6 clutch discs  280  in quantities sufficient to provide adequate cooling and lubrication, which may lead to overheating or damage. 
     Accordingly, it is desirable to provide a clutch hub assembly of an automatic transmission configured to allow for improved cooling and lubrication oil flow to clutch plates and steel separator plates. 
     SUMMARY 
     According to one embodiment, a clutch hub may include an annular channel-shaped body defining an inner portion between an outer radial wall, an inner radial wall and a forward axial wall, the annular channel-shaped body extending about a central opening. One or more first oil holes may extend through the outer radial wall, one or more second oil holes may extend through the inner radial wall, and an oil dam may extend radially inward from the inner radial wall. An oil flow path may extend from the central opening through the one or more second oil holes, the inner portion, and the one or more first oil holes. 
     The annular channel-shaped body may further include a connecting flange extending radially inward from the inner radial wall, the connecting flange positioned axially rearward from the oil dam. The outer radial wall has an outer surface, and the outer surface may include a plurality of splines. The annular channel-shaped body may have an axially rearward facing open side. Another oil flow path may extend into the inner portion through the axially rearward facing open side. 
     According to another embodiment, a clutch hub assembly may include a clutch hub defining an inner portion between an outer radial wall, an inner radial wall and a forward axial wall, the clutch hub extending about a central opening. One or more first oil holes may extend through the outer radial wall. One or more second oil holes may extend through the inner radial wall. An oil dam may extend radially inward from the inner radial wall. A connecting flange may extend radially inward from the inner radial wall and may be positioned axially rearward from the oil dam. A hub shaft may be connected to the connecting flange. A clutch dampener may be disposed in the inner portion, the clutch dampener having a first axial face having a plurality of grooves facing the forward axial wall and a second axial face facing an open side of the clutch hub. An apply plate may be positioned adjacent to the second axial face of the clutch dampener, and a retainer ring may be configured to apply a preload to the apply plate to urge the apply plate toward the second axial face of the clutch dampener and the first axial face of the clutch dampener toward the forward axial wall. An oil flow path may extend from the central opening through the one or more second oil holes into the inner portion, between the clutch dampener and the forward axial wall, and through the one or more first oil holes. 
     The outer radial wall may have an outer surface, and the outer surface including a plurality of splines. The oil flow path may extend in at least one groove of the plurality of grooves of the first axial face between the clutch dampener and the forward axial wall. The open side may face an axially rearward direction. Another oil flow path may extend into the inner portion through the axially rearward facing open side. 
     According to still another embodiment, an automatic transmission may include a clutch hub defining an inner portion between an outer radial wall, an inner radial wall and a forward axial wall, the clutch hub extending about a central opening. One or more first oil holes may extend through the outer radial wall, one or more second oil holes may extend through the inner radial wall, and an oil dam may extend radially inward from the inner radial wall. A connecting flange may extend radially inward from the inner radial wall, the connecting flange positioned axially rearward from the oil dam. A hub shaft may be connected to the connecting flange. A clutch dampener may be disposed in the inner portion, the clutch dampener having a first axial face having a plurality of grooves facing the forward axial wall and a second axial face facing an open side of the clutch hub. An apply plate may be positioned adjacent to the second axial face of the clutch dampener and a retainer ring may be configured to apply a preload to the apply plate to urge the apply plate toward the second axial face of the clutch dampener and the first axial face of the clutch dampener toward the forward axial wall. A housing assembly may include a housing shaft and a piston dam. The housing shaft may include one or more housing shaft oil holes and the piston dam may include one or more piston dam oil holes. An oil flow path may extend from the central opening through the one or more second oil holes into the inner portion, between the clutch dampener and the forward axial wall, and through the one or more first oil holes. 
     The oil flow path may be a first oil flow path, and the first oil flow path may further extend between the hub shaft and the shaft to the central opening. The oil flow path may be a second oil flow path, and the second oil flow path may further extend through the one or more housing shaft oil holes and the one or more piston dam oil holes to the central opening. The open side faces an axially rearward direction. Another oil flow path may extend into the inner portion through the axially rearward facing open side. 
     Other objects, features, and advantages of the disclosure will be apparent from the following description, taken in conjunction with the accompanying sheets of drawings, wherein like numerals refer to like parts, elements, components, steps, and processes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view illustrating a known OE 4-5-6 clutch hub assembly; 
         FIG. 2  is a cross-sectional view illustrating a known OE 4-5-6 clutch hub assembly; 
         FIG. 3  is an exploded view illustrating a known OE 4-5-6 clutch hub assembly, a known OE 4-5-6 housing assembly and a known OE 1-2-3 clutch hub assembly of an OE automatic transmission; 
         FIG. 4  is an exploded view illustrating a known OE 4-5-6 housing assembly; 
         FIG. 5  is a cross-sectional diagram illustrating a known OE automatic transmission; 
         FIG. 6  is a cross-sectional diagram illustrating an enlarged portion of the OE automatic transmission of  FIG. 5 , including DETAIL A; 
         FIG. 7  is a cross-sectional diagram illustrating a portion of an automatic transmission having a clutch hub assembly according to an embodiment; 
         FIGS. 8A and 8B  are plan views illustrating the first axial face and the second axial face, respectively, of the clutch dampener, according to an embodiment; 
         FIG. 9  is a cross-sectional diagram illustrating the portion of the automatic transmission of  FIG. 7  having a first oil flow path for the clutch hub assembly according to an embodiment; 
         FIG. 10  is a cross-sectional diagram illustrating the portion of the automatic transmission of  FIG. 7  having a second oil flow path for the clutch hub assembly according to an embodiment; and 
         FIG. 11  is a cross-sectional diagram illustrating the portion of the automatic transmission of  FIG. 7  having a combination of oil flow paths for the clutch hub assembly according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     While the present disclosure is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described one or more embodiments with the understanding that the present disclosure is to be considered illustrative only and is not intended to limit the disclosure to any specific embodiment described or illustrated. 
       FIG. 7  is a cross-sectional diagram illustrating a portion of an automatic transmission  700  having a clutch hub assembly  710  according to an embodiment. The clutch hub assembly  710  may include a clutch hub  712 , a hub shaft  730 , a clutch dampener  740 , an apply plate  750  and a retainer ring  760 . The clutch hub assembly  710  of present embodiments may be a 4-5-6 clutch hub assembly for use in the General Motors Hydra-Matic 6 Speed rear wheel drive transmission with the 6L45/6L50/6L80/6L90 designations. 
     In an embodiment, the clutch hub assembly  710  may be the same as the OE clutch assembly  110  with the exception of the clutch hub  712 . For example, in an embodiment, the hub shaft  730 , the clutch dampener  740 , the apply plate  750  and the retainer ring  760  may be the same or substantially the same as the OE hub shaft  130 , the OE clutch dampener  140 , the OE apply plate  150  and the OE retainer ring  160 , respectively. Thus, in an embodiment, the clutch hub assembly  710  may be a modified version of the OE clutch hub assembly  110  in which the OE clutch hub  120  is replaced with the clutch hub  712  of the present embodiments. 
     In an embodiment, the OE clutch hub assembly  110  may be modified to form the clutch hub assembly  710  by removing the OE clutch hub  120  from the OE hub shaft  130 . The clutch hub  712  may be connected to the OE hub shaft  130  (or hub shaft  730 ). 
     The clutch hub  712  may be an annular channel-shaped body having an outer radial wall  713 , an inner radial wall  714  and a forward axial wall  715  generally defining an inner portion  716  of the annular channel-shaped body. The inner portion  716  may be open in a rearward axial direction. The annular channel-shaped body may extend about a central opening  717 . 
     The outer radial wall  713  includes an inner surface facing the inner portion  716  and an outer surface facing away from the inner portion  716 . The outer surface may include a plurality of splines  718 . One or more first oil holes  719  may be formed in the outer radial wall  713 . The first oil holes  719  are configured to allow for oil to flow out of the inner portion  716  through the outer radial wall  713 . 
     The inner radial wall  714  may include one or more second oil holes  720 . The second oil holes  720  are configured to allow for oil to flow from the central opening  717  into the inner portion  716  through the inner radial wall  714 . The clutch hub  712  may also include a connecting flange  721  extending from a rear section of the inner radial wall  714 . The connecting flange  721  is configured to be connected to the hub shaft  730 . 
     The clutch hub  712  may further include an oil dam  722  projecting radially inward from the inner radial wall  714 . The oil dam  722  may stop or impede oil in the central opening  717  from flowing out of the central opening  717  and around the forward axial wall  715  of the clutch hub  712 . Accordingly, the oil dam  722  may direct the oil to flow into the second oil holes  720 . In an embodiment, the oil dam  722  is positioned axially forward of the connecting flange  721 . 
     The clutch dampener  740  may be an annular ring-shaped body. The clutch dampener  740  may be disposed substantially or entirely within the inner portion  716  of the clutch hub  712 . The clutch dampener  740  may include a first axial face  742  facing the forward axial wall  715  and a second axial face  744  facing in the rearward axial direction. The first axial face  742  and the second axial face  744  may each include a bonded friction material. 
       FIGS. 8A and 8B  are plan views illustrating the first axial face  742  and the second axial face  744 , respectively, of the clutch dampener  740 , according to an embodiment. The first axial face  742  may include a plurality radially extending, circumferentially spaced grooves  746 . The grooves  746  may be formed in the bonded friction material. The second axial face  744  may form a substantially planar or flush surface  748  (i.e., a surface without grooves). The substantially planar or flush surface  748  may be formed by the bonded friction material. 
     Referring again to  FIG. 7 , the apply plate  750  may be an annular ring-shaped body. The apply plate  750  may be positioned adjacent to the second axial face  744  of the clutch dampener  740 . The apply plate  750  may include a first axial face  752  facing the second axial face  744  of the clutch dampener  740 . The apply plate  750  also includes a second axial face  754  facing in the rearward axial direction. 
     The retainer ring  760  may be an annular wave spring. The retainer ring  760  may apply a preload to the apply plate  750  in the forward axial direction. Accordingly, the first axial face  752  of the apply plate  750  may be urged against the second axial face  744  of the clutch dampener  740 . In an embodiment, a sealing surface may be formed between the first axial face  752  of the apply plate  750  and the second axial face  744  of the clutch dampener  740  under the force of the preload. The preload may also urge the first axial face  742  of the clutch dampener  740  against the forward axial wall  715  of the clutch hub  712 . A sealing surface may be formed between the non-grooved portions of the first axial face  742  on the clutch dampener  740  and the forward axial wall  715  of the clutch hub  712 . A fluid flow path between the forward axial wall  715  and the first axial face  742  may be provided by the grooves  746  of the clutch dampener  740 . 
     The hub shaft  730  may extend in the axial direction generally rearward from the clutch hub  712 . The hub shaft  730  may include a radial shaft flange  732 , which may be connected to the connecting flange  721  of the clutch hub  712  using known, suitable fastening techniques. The hub shaft  730  may accommodate the known rear oil feed  512 . The hub shaft  730  may include a forward portion  734 , extending axially forward relative to the radial shaft flange  732 . 
     In an embodiment, the OE clutch hub assembly  110  of the OE transmission  510  may be modified by replacing the OE clutch hub  120  with the clutch hub  712  of the present embodiments. For example, the OE clutch hub  120  may be removed from the OE hub shaft  130  and the clutch hub  712  may be installed in place of the OE clutch hub  120 . In an embodiment, the clutch hub  712  may be connected to the OE hub shaft  130 . 
     The automatic transmission  700  further includes a multiple disc wet clutch pack  780  comprising a plurality of clutch plates  782  and separator clutch discs  784 . The clutch plates  782  and the separator clutch discs  784  may be alternatingly positioned with one another. The clutch plates  782  and separator clutch discs  784  may be the same as the OE friction clutch plates  270  and OE separator clutch discs  280  of the OE automatic transmission  510 . 
       FIG. 9  is a diagram illustrating the section of the automatic transmission  700  of  FIG. 7 , and further illustrating an example of a first oil flow path P 1  for the clutch hub assembly  712 , according to an embodiment. 
     The automatic transmission  700  also includes a housing assembly  910 . The housing assembly  910  may include a housing body  920 , a housing shaft  930 , a clutch piston  940 , a clutch spring  950  and a clutch piston dam  960 . 
     The housing shaft  930  extends in the axial direction forward from the hub shaft  730 . The housing shaft  930  may include a rear portion  932  which overlaps with the forward portion  734  of the hub shaft  730  in the axial direction and is spaced from the forward portion  734  in the radial direction. 
     An axial gap  934  is formed between the rear portion  932  of the housing shaft  930  and a portion of the hub shaft  730 . In addition, a radial gap  936  is formed between the rear portion  932  of the housing shaft  930  and the forward portion  734  of the hub shaft  730 . A housing shaft thrust bearing  912  may be disposed between the housing shaft  930  and the hub shaft  730 , for example, in the axial and/or radial gap  934 ,  936 . 
     The housing body  920  may extend radially from the housing shaft  930 . The clutch piston  940 , clutch spring  950  and clutch piston dam  960  may be disposed axially between the housing body  920  and the clutch hub  712 . In addition, the clutch piston  940 , the clutch spring  950  and the clutch piston dam  960  may be disposed within the housing body  920 . 
     As shown in  FIG. 5 , in the OE automatic transmission  100 , oil may be supplied through the OE rear oil feed  512  and the first oil feed  516 . However, in the OE automatic transmission  100 , oil does not flow into the interior portion  122  of the OE clutch hub from the central opening through an inner radial wall of the OE clutch hub  120 . Instead, as shown in  FIG. 6 , in the OE clutch hub assembly  110 , oil flows into the interior portion of the OE club hub  120  through the open rearward facing side of the OE clutch hub  120 . 
     According to embodiments herein, however, the clutch hub  712  is configured to receive oil from the first oil feed  516  due, at least in part, to the one or more second oil holes  720  of the inner radial wall  714  and the oil dam  722 . That is, by including the second oil holes  720  in the inner radial wall  714 , an oil flow path, i.e., the first oil flow path P 1 , may be provided through the clutch hub  712  to the clutch pack  780  from the first oil feed  516 . 
     The first oil flow path P 1  is indicated by a series of dots and arrows in  FIG. 9 . In an embodiment, oil may be provided to the clutch hub assembly  710  from a rear oil feed, such as the OE rear oil feed  512  and the first oil feed  516  ( FIG. 5 ). The first oil flow path P 1  may extend from the first oil feed  516  between the housing shaft  930  and the hub shaft  730 , and through the housing thrust bearing  912 . 
     For example, the first oil flow path P 1  may extend through the radial gap  936  between the rear portion  932  of the housing shaft  930  and the forward portion  734  of the hub shaft  730 . The first oil flow path P 1  may also extend through the axial gap  934  between the rear portion  932  of the housing shaft  930  and the radial shaft flange  732  of the hub shaft  730 . In an embodiment, the first oil flow path P 1  may extend through the housing thrust bearing  912  in the axial gap  934 . 
     The first oil flow path P 1  may further extend radially outward from the axial gap  934  into the central opening  717  of the clutch hub  712 . The first oil flow path P 1  may extend in the central opening  717  in an area generally bounded by portions of the clutch hub  712 , the hub shaft  730  and the housing assembly  910 . In an embodiment, the oil dam  722  may substantially restrict or prevent oil from flowing around the inner radial wall  714  to an area axially forward of the forward axial wall  715 . 
     The first oil flow path P 1  may further extend through the one or more second oil holes  720  in the inner radial wall  714  and into the inner portion  716  of the clutch hub  712 . In the inner portion  716 , the first oil flow path P 1  may be substantially limited or restricted at the second axial face  744  of the clutch dampener  740 , for example, by way of the sealing surface formed by planar or flush surface  748  contacting the first axial face  752  of the apply plate  750  ( FIG. 0.7 ). 
     Instead, the first oil flow path P 1  may extend around the first axial face  742  of the clutch dampener  740 . For example, the first oil flow path P 1  may extend between the first axial face  742  and the forward axial wall  715  through one or more of the grooves  746  of the bonded friction material of the first axial face  742  ( FIG. 8A ). The first oil flow path P 1  may extend between the inner surface of the outer radial wall  713  and the clutch dampener  740 , and further, through the first oil holes  719  of the outer radial wall  713 . 
     Thus, in an embodiment, cooling and lubricating oil may be provided to the clutch pack  780  via the first oil flow path P 1 . In an embodiment, the oil may be also supplied to the clutch pack  780  from the OE oil flow path OEP shown in  FIG. 6 . Thus, oil flow to the clutch pack  780  from the first oil flow path P 1  may supplement oil flow to the clutch pack  780  from the OE oil flow path OEP. 
     In an embodiment, the housing assembly  910  may be same as the OE housing assembly  210 . 
       FIG. 10  is a diagram illustrating the section of the automatic transmission  700  of  FIG. 7 , and further illustrating an example of a second oil flow path P 2  for the clutch hub assembly  712 , according to an embodiment. 
     In an embodiment, the housing shaft  930  may include one or more oil holes  938  and the piston dam  960  may also include one or more oil holes  962 . In an embodiment, the one or more oil holes  938  of the housing shaft  930  may be disposed generally at the rearward portion  932 . 
     Thus, in an embodiment, the second oil flow path P 2  may extend from the first oil feed  516  through the one or more oil holes  938  of the housing shaft  930 . The second oil feed path P 2  may extend through a space between the housing shaft  930  and the piston dam  960 . The second oil flow path P 2  may then extend through the one or more oil holes  962  of the piston dam  960  into the central opening of the clutch hub  717 . 
     The second oil flow path P 2  may be limited or restricted by the oil dam  722  of the clutch hub  712  such that oil is substantially prohibited from flowing around a front side of the forward axial wall  715  of the clutch hub  712 . The second oil flow path P 2  may further extend through the clutch hub  712  to provide oil to the clutch pack  780  in a manner similar to the first oil flow path P 1  described above. That is, the second oil flow path P 2  may extend through the one or more second oil holes  720  of the inner radial wall  714  of the clutch hub  712  into the inner portion  716 . The second oil flow path P 2  may then extend between the first axial face  742  of the clutch dampener  740 , for example, through the grooves  746  of the bonded friction material, and the forward axial wall  715 , and through the first oil holes  719  of the outer radial wall  713 . 
     Accordingly, the lubricating and cooling oil may be supplied to the clutch pack  780  the second oil flow path P 2 . Oil supplied from the second oil flow path P 2  may be the sole or primary source of oil provided to the clutch pack  780 , or may supplement oil supplied to the clutch pack  780  from the first oil flow path P 1  and/or the OE oil flow path OEP. 
     In an embodiment, the housing assembly  910  may optionally be a modified version of the OE housing assembly  210 . For example, the housing assembly  910  may be formed by modifying or replacing the OE clutch piston dam  260  with the clutch piston dam  960  of the present embodiments. 
     For example, in an embodiment, the OE housing assembly  210  may be modified by machining the OE clutch piston dam  260  to include the one or more oil holes  962 . Alternatively, the OE clutch piston dam  260  may be removed from the OE automatic transmission and replaced with the clutch piston dam  960  of the present embodiments, including the one or more oil holes  962 . 
     The housing assembly  910  may be used in the OE automatic transmission  510  in conjunction with a 4-5-6 clutch hub assembly, such as the clutch hub assembly  710  of the present embodiments. Thus, the housing assembly  910  may be a 4-5-6 housing assembly  910  in the automatic transmission  700 . 
       FIG. 11  is a diagram illustrating the section of the automatic transmission  700  of  FIG. 7 , and further illustrating examples of the first oil flow path P 1 , second oil flow path P 2 , and the OE oil flow path OEP used together for the clutch hub assembly  710 , according to an embodiment. The automatic transmission  700  may supply oil to the clutch pack  780  through any of the OE oil flow path OEP, the first oil flow path P 1 , and/or the second oil flow path P 2 , or combinations thereof. For example, oil may be supplied using the OE oil flow path and either or both of the first oil flow path P 1  and the second oil flow path P 2 . In this manner, a volume flow rate of cooling and lubricating oil supplied to the clutch pack  780  may be increased compared to the OE automatic transmission  510 . That is, oil supplied to the clutch pack  780  from the first and/or second oil flow paths P 1 , P 2  may supplement oil supplied from the OE oil flow path OEP. 
     Further, in an embodiment, additional oil may be supplied to the clutch pack  780  increasing a width and/or depth of the grooves  746  of the first axial face  742  of the clutch dampener  740  compared to the OE clutch dampener  140 . For example, the OE clutch dampener  140  of the OE clutch hub assembly  110  may be replaced with a modified clutch dampener having grooves on the first axial face which have a greater width and/or depth than the grooves of the OE clutch dampener. The modified clutch dampener may be an OE clutch dampener that has been removed and machined to increase the groove width and/or depth. Alternatively, the modified clutch dampener may be a newly manufactured component which may replace the OE clutch dampener. In an embodiment, the clutch dampener  740  may be the modified clutch dampener. 
     In the embodiments above, an OE clutch hub assembly  110  may be modified by replacing the OE clutch hub  120  with the clutch hub  712  of the present embodiments. Thus, the clutch hub assembly  710  of the present embodiments may be a modified version of the OE clutch hub assembly  110 . The clutch hub assembly  710  according to embodiments herein may provide for increased oil flow to the clutch pack  780  in the manner described above. 
     Portions of the automatic transmission  700  shown in the drawings, or which are not expressly described otherwise above may be considered to be OE components of the OE automatic transmission  510 . Further, the automatic transmission  700  of the present embodiments may be a modified version of the OE automatic transmission  510 . For example, the OE automatic transmission  510  may be modified by replacing the OE clutch hub  120  with the clutch hub  712  of the present embodiments, to replace the OE housing shaft  230  with the housing shaft  930  of the present embodiments, and to replace the OE piston dam  160  with the piston dam  760  of the present embodiments. Further still, in an embodiment, the OE clutch dampener  140  may be replaced with the clutch dampener  740  of the present embodiments, the clutch dampener  740  having modified grooves  746  configured to allow for increased radially outward flow of oil between the clutch dampener  740  and the forward axial wall  715 . 
     It is understood that the features described with respect to any of the embodiments above may be implemented, used together with, or replace features described in any of the other embodiments above. It is also understood that description of some features may be omitted in some embodiments, where similar or identical features are discussed in other embodiments. 
     All patents referred to herein, are hereby incorporated herein in their entirety, by reference, whether or not specifically indicated as such within the text of this disclosure. 
     In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. In addition, in is understood that terminology referring to directions or relative orientations, such as, but not limited to, “upper” “lower” “raised” “lowered” “top” “bottom” “above” “below” “alongside” “left” and “right” are used for purposes of example and do not limit the scope of the subject matter described herein to such orientations or relative positioning. 
     From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.