Patent Publication Number: US-2012024656-A1

Title: Flywheel having lubrication-flow passageway

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a divisional of U.S. patent application Ser. No. 11/830,278, filed on Jul. 30, 2007. 
    
    
     TECHNICAL FIELD 
     This patent disclosure relates generally to lubrication of components used in systems for transmission of mechanical power, and more particularly to lubrication passageways formed in such components. 
     BACKGROUND 
     Systems for transmitting mechanical power that include flywheels and clutches are known. These systems typically include a driver portion that generates power, for example, an internal combustion engine or electric motor, and a driven portion, for example, a vehicle transmission or a generator. Such systems often operate under severe temperature conditions, and individual components included in these systems, such as clutches, may require lubrication that both reduces unwanted friction and provides cooling. 
     Providing lubrication for clutches has typically been accomplished by incorporating fluid conduits that receive lubricant from the driver portion and which deliver the lubricant to the clutch by extending around other intermediary components, such as flywheels. Even though such designs have proven effective in the past, incorporating fluid conduits into a transmission in this manner can be costly and complex. These fluid conduits are typically made of steel tubing that is bent into a shape that follows a usually narrow and tortuous path connecting a source of lubricant from the driver portion to the clutch. 
     BRIEF SUMMARY OF THE INVENTION 
     A flywheel for transferring a flow of lubricant includes a hub portion concentrically defined around a center of the flywheel, and a body portion having a driver-side face and a driven-side face. A plurality of passageways are defined in the body portion that extend through the flywheel and fluidly connect the driver-side face with the driven-side face. Each of the plurality of passageways is configured to receive a portion of a flow of lubricant spilling onto the driver-side of the body portion when the flywheel is rotating, and to expel the lubricant out of the driven-side face of the body portion. 
     A method of lubricating a clutch located on the driven-side of a flywheel, while the flywheel is rotating, includes the step of providing the flow of lubrication fluid that spills onto a driver-side of the flywheel. A portion of the flow of lubrication is received by at least one of the passageways extending through the flywheel, and expelled on the driven-side of the flywheel to lubricate the clutch. 
     In one embodiment, a transmission in accordance with the disclosure can include a clutch connected to a driven-system, and a flywheel connected to a driver-system. At least one collector in fluid communication with at least one passageway can be defined in the body portion. An idle gear in contact with a hub gear connected to the flywheel can be configured to receive a flow of lubrication fluid from the driver-system during operation, such that a lubrication path for a flow of lubrication fluid is defined between a rotating interface of the idle gear, the collector, the passageway, and the clutch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross-section of a transmission system having a flywheel in accordance with the disclosure. 
         FIG. 2  is an outline view of a spatial relationship between a flywheel and two idler gears in an installed condition, a cross section of which is shown in  FIG. 1 . 
         FIG. 3  is an outline view of a flywheel having lubrication flow features in accordance with the disclosure. 
         FIG. 4  is an outline view of the flywheel shown in  FIG. 3  with a ring flange installed in accordance with the disclosure. 
         FIG. 5  is a partial cut-away view of a flywheel and several of the surrounding components. 
         FIG. 6  is a cross-section view of the flywheel shown in  FIG. 5  that includes a lubrication flow passageway in accordance with the disclosure. 
         FIG. 7  is an enlarged view of the cross section of the flywheel illustrated in  FIG. 6 . 
         FIG. 8  is a partial three-quarter cross-section of an alternate embodiment for the flywheel shown in  FIG. 5 , where the cross section has been taken over a ninety degree segment about the centerline of the flywheel. 
         FIG. 9  is a partial cross-section of another alternate embodiment for the flywheel shown in  FIG. 5 . 
         FIG. 10  is a fragmentary view of a segment of an alternate embodiment of the flywheel shown in  FIG. 5 . 
         FIG. 11  is a partial cross-section of the flywheel shown in  FIG. 3 . 
         FIG. 12  is a partial cross-section of an alternate embodiment for the flywheel shown in  FIG. 3 ; in this embodiment, the flywheel includes a passageway that is capable of accelerating a flow of lubricant. 
         FIG. 13  is a partial cross-section of an additional alternate embodiment for the flywheel shown in  FIG. 3 ; in this embodiment, the flywheel includes a passageway that is capable of decelerating a flow of lubricant. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates to an apparatus and method of lubricating rotating components in a transmission system. The lubrication arrangement disclosed herein includes at least one collector formed in a rotating flywheel to collect and redirect lubricant to other components. The flow of lubricant is routed from the collector into a passageway extending through the flywheel such that a component, for example a slip-clutch, which is positioned behind the flywheel, may be lubricated. 
     An outline view of one example of a transmission system  100  according to the disclosure is shown in  FIG. 1 . The transmission system  100  connects a driver system  102  to a driven system  104  such that mechanical power can be transmitted from the driver system  102 , through the transmission system  100 , to the driven system  104 . In the example shown, the driver system is an internal combustion engine (not shown) having a crankshaft  106  connected to a hub gear  108  of the transmission system  100 . The hub gear  108  may be connected to a flywheel  110  which can operably cause a clutch  112  to rotate. The clutch  112 , in this example, is connected to an armature assembly  114  of a generator  116 . The transmission system  100  is capable of driving other components in addition to the driven system  104  by use of idler gears  118  that are meshed with a hub gear portion  120  of the hub gear  108 . The flywheel  110  is advantageously symmetrical about a centerline  122  and has a ring-flange  124  connected concentrically on the flywheel  110 . The ring-flange  124  is connected on a driver-side  126  of the flywheel  110  that is on an opposite side from the driven side  128  of the flywheel  110 . The driven side  128  of the flywheel  110 , as shown, is the side facing the clutch  112 . 
     An outline view of the flywheel  110  and the idler gears  118  as installed in the transmission  100  relative to each other, but with other surrounding components removed for clarity, is shown in  FIG. 2 . The ring-flange  124  is connected to a body portion  202  of the flywheel  110 . A series of collector openings  204  are defined between the ring-flange  124  and the body portion  202 . Each opening  204  is an arcuately extending area between two adjacent collector posts  206 . In general, the space between the body portion  202 , the ring-flange  124 , and two adjacent collector posts  206 , defines each collector opening  204 . 
     An outline view of the flywheel  110  with the ring-flange  124  removed is shown in  FIG. 3 , and an outline view of the flywheel  110  with the ring-flange  124  installed is shown in  FIG. 4 . The hub gear  108  has been removed from both illustrations for clarity. The flywheel  110  includes a plurality of passageway openings  302  defined in the body portion  202 . Each of the passageway openings  302  is in fluid communication with a respective one of a plurality of collectors  304 . Each collector  304  is open to a respective collector opening  204 , as described, and extends in a generally tangential direction with respect to the flywheel  110 . Each collector  304  fluidly connects each collector&#39;s respective collector opening  204  with a respective passageway opening  302 . 
     A series of curved projections  306  are formed on the body portion  202 . The projections  306  extend from a peripherally extending flange  308  along the driver-side  126 . The peripherally extending flange  308  is located on the body portion  202  and surrounds the hub portion  310  of the flywheel  110 . Each projection  306  extends in an outward direction with respect to the center  312  of the flywheel  110 , and curves to follow a tangential path that generally forms one side of a respective collector  304 . A distal end of each of the projections  306  forms the respective collector post  206 . In the exemplary embodiment shown, the ring flange  124  may advantageously be press-fit onto the flywheel  110  over the peripherally extending flange  308  and at least a portion of each of the projections  306  to both enclose and at least partially define each of the collectors  304 . 
     An outline view of the flywheel  110  and a number of surrounding components is shown in  FIG. 5 . One of the idler gears  118  and the ring flange  124  are partially cut away for illustration. During operation, the flywheel  110  rotates in a direction “R” denoted by the curved arrows. The hub gear  108  connected to the flywheel  110  rotates with the flywheel  110  causing each of the two idler hears  118  to rotate. Each of the idler gears  118  rotates about a respective hub  502  that passes through the center of each gear  118 . 
     A flow of lubrication fluid may be provided to each hub  502  during operation. The flow of lubrication fluid may pass through and lubricate a rotational interface  504  between each idler gear  118  and its respective hub  502 , and spill out of each interface  504  through one or more openings  505 . The flow of lubrication fluid spilling out of each interface  505  may advantageously be a jet stream of lubricant that wets at least a portion of the flywheel  110 . The flow of lubrication fluid may at least partially fall into one or more of the collector openings  204  as the flywheel  110  rotates. The portion of the lubrication flow entering each opening  204  may advantageously be “scooped-up” by each projection  306 , enter the respective collector  304 , and be routed to the respective passageway opening  302 . The flow of lubricant passing through the interface  504  may be continuous or intermittent during operation. 
     A cross-section of the flywheel  110  and surrounding components is shown in  FIG. 6 , and a detail view of a region around one of the idler gears  118  is shown in  FIG. 7 . In the exemplary views shown, a portion of one of the collectors  304  is sectioned through a portion that intersects the respective passageway opening  302 . A passageway  602  defined in the body portion  202  of the flywheel  110  extends through the body portion  202  and fluidly connects the collector  304  with an outlet opening  604 . While the flywheel  110  is rotating, the portion of the flow of lubricant spilling out of the interface  504  of each of the idler gears  118  enters into or is scooped up by the collector  304 . While in the collector  304 , the portion of the flow of lubricant is channeled into the passageway  602  through the passageway opening  302 . The portion of the flow of lubricant travels through the flywheel  110  along the passageway  602 , and exits the flywheel  110  on the driven side  128  through the outlet opening  604 . The portion of the flow of lubricant exiting on the driven side  128  can advantageously be used to lubricate other components, such as the clutch  112 , without additional lubrication conduits provided external to the flywheel  110 . 
     A cross-section view of an alternate embodiment for a flywheel  800  having a lubrication flow passageway  802  extending through the flywheel  800  is shown in  FIG. 8 . The flywheel  800  has a driver-side  804  connected to, for example, a rotating crankshaft (not shown), and a driven side  806  that operatively drives a clutch, shown generally at  808 . A hub gear  810  is connected to the flywheel  800  along a hub portion  812  of the flywheel  800  that surrounds a centerline A-A of the flywheel  800 . A body portion  814  of the flywheel  800  may be defined as the portion of the flywheel that surrounds the hub portion  812 . The flow passageway  802  can be one of a plurality of flow passageways  802  that are formed in the body portion  814  of the flywheel  800 . Each of the plurality of flow passageways  802  may extend entirely through the body portion  814  of the flywheel  800 . 
     Each of the one or more passageways  802  can advantageously provide an intermittent “line of sight” to the clutch  808  while the flywheel  800  rotates during operation, the line of sight originating from a spray-source of lubricant  816  that can be located off the driver-side  804  of the flywheel  800 . As it can be appreciated, an intermittent spray of lubricant following a line-of-sight path  818  that passes through the flywheel  800  may be applied to the clutch  808  directly from the spray-source  816 . The spray-source  816  may operate to continuously spray lubricant, or may alternatively be arranged to intermittently spray lubricant at times when the line-of-sight path  818  is open to the clutch  808  as the flywheel  800  rotates. 
     A cross-sectional view of an additional alternate embodiment for a flywheel  900  having a lubrication flow passageway  902  extending through the flywheel  900  is shown in  FIG. 9 . The passageway  902  may be defined in a body portion  904  of the flywheel  900  and extend through the entire flywheel  900 . A hub gear  906  may be concentrically connected to the flywheel  900 . A circumferential channel  908  can be defined along a peripheral surface  910  surrounding an interface  912  between the flywheel  900  and the hub gear  906 . The circumferential channel  908  can contain a circumferential flow-deflector  914 . The circumferential flow-deflector  914  may have a “J” shaped cross section, and may act as a reservoir for lubrication fluid. Additionally, the flow-deflector  914  may deflect a flow of lubricant that enters the channel  908  such that a portion of the flow of lubricant enters the one or more passageways  902 . 
     The flow of lubricant can advantageously pass into the channel  908 , be flung-off the deflector  914  while the deflector  914  rotates with the flywheel  900 , enter the one or more passageways  902 , and be sprayed onto a clutch  918  that may be positioned behind the flywheel  900 . In this fashion, the clutch  918  can be lubricated during operation without the addition of specially positioned lubrication passageways that may be routed around the flywheel  900 . 
     A cross-section of an alternate embodiment for a flywheel  1000  is shown in  FIG. 10 . The flywheel  1000  has a body portion  1001  that defines a plurality of passageway openings  1002 . Each of the passageway openings  1002  is in fluid communication with a respective one of a plurality of collectors  1004 . Each collector  1004  extends along a path  1005  that has a radial portion  1006  and a tangential portion  1008  with respect to the flywheel  1000 . 
     In this embodiment, a series of curved projections  1010  are formed in the body portion  1001  and extend in an outward direction, generally following the shape of each collector  1004  along the path  1005 . As it can be appreciated, the segment of each collector  1004  disposed around the radial portion  1006  of the path  1005  may collect lubricant during operation of the flywheel  1000  such that there are no interruptions in the supply of lubricant exiting each passageway opening  1002 . 
     A cross-section of a segment of a flywheel  1100  is shown in  FIG. 11 . Consistent with the description thus far, the flywheel  1100  forms a passageway  1102  that extends through a body portion  1104  of the flywheel  1100 . A centerline  1106  of the passageway  1102  forms a right angle with respect to a driven-side face  1108  of the flywheel  1100 . Stated differently, the centerline  1106  of the passageway  1102  is generally parallel to an axis of rotation of the flywheel  1100  during operation. In this configuration, centripetal forces acting upon lubricant found in the passageway  1102  do not accelerate or decelerate the lubricant to an appreciable extent. Lubricant entering a respective collector  1110  displaces lubricant already in the collector  1108 , and acts to push lubricant through the passageway  1102 . 
     A cross-section of a segment of an alternate embodiment for a flywheel  1200  is shown in  FIG. 12 . In this embodiment, the flywheel  1200  forms a passageway  1202  that extends through a body portion  1204  of the flywheel  1200 . A centerline  1206  of the passageway  1202  forms an angle, α, with respect to a driven-side face  1208  of the flywheel  1200 . If the centerline  1206  were considered to conscribe a theoretical conic surface during rotation of the flywheel  1200 , then the conic surface would have its apex lying on an axis of rotation of the flywheel  1200 , the apex located on a driver-side  1210  of the flywheel  1200 . Stated differently, the angle α in this embodiment acts to slant the passageway  1202  away from a direction of rotation of the flywheel  1200  such that centripetal forces acting upon lubricant found in the passageway  1202  act to accelerate the flow of lubricant through the passageway  1202  and cast lubricant out of the passageway  1202 . 
     A cross-section of a segment of an alternate embodiment for a flywheel  1300  is shown in  FIG. 13 . In this embodiment, the flywheel  1300  forms a passageway  1302  that extends through a body portion  1304  of the flywheel  1300 . A centerline  1306  of the passageway  1302  forms an angle, β, with respect to a driven-side face  1308  of the flywheel  1300 . If the centerline  1306  were considered to conscribe a theoretical conic surface during rotation of the flywheel  1300 , then the conscribed conic surface would have its apex lying on an axis of rotation of the flywheel  1300 , the apex located on the driven-side  1308  of the flywheel  1300 . Stated differently, the angle β in this embodiment acts to slant the passageway  1302  toward a direction of rotation of the flywheel  1300  such that centripetal forces acting upon lubricant found in the passageway  1302  act to decelerate the flow of lubricant in the passageway  1302 . 
     INDUSTRIAL APPLICABILITY 
     The industrial applicability of the flywheel having at least one lubrication-flow passageway described herein will be readily appreciated from the foregoing discussion. Integration of one or more passageways for permitting a flow of lubricant through the flywheel simplifies existing lubrication arrangements. The embodiments described herein reduce or eliminate the need to provide separate cooling passageways that are routed around the flywheel. A transmission system that includes the flywheel can effectively and efficiently be adequately lubricated during operation by providing a lubrication passageway through the flywheel, and by providing features that induce the flow of lubricant through the lubrication passageway. 
     In general, a method of lubricating a clutch that is positioned on a driven-side of a rotating includes the step of providing a flow of lubrication fluid spilling onto a driver-side face of the flywheel. At least a portion of the flow of lubrication fluid can be received into a passageway through at least one collector or directly into a passageway that extends through the flywheel. The flow may be induced to move through the passageway, for example by use of a deflector, a spray-source, or a tangentially extending collector that uses centripetal forces to push the lubricant into the passageway. The flow from the passageway can be expelled from a driven-side of the flywheel to lubricate a clutch that may be positioned on the driven-side of the flywheel. 
     The present disclosure is applicable to any transmission systems utilizing at least one rotating flywheel that operatively causes rotation of a clutch. The embodiments described herein relate generally to a transmission system for transferring power from a driver system, for example an internal combustion engine, to a driven system, for instance a generator. The apparatus and methods described herein for lubricating a clutch can be used in many other different types of applications involving the transfer of power between a driver and a driven system. 
     It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the invention or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the invention more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the invention entirely unless otherwise indicated. 
     Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 
     Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.