Retainer for rotating members

A retainer for coupling rotating shafts includes a body and a finger. The body may have a curved section extending in a circumferential direction about an axis and a pair of ends. The finger extends from the body and has a least a portion that extends inwardly toward the axis. The finger may be flexible and resilient and have an at rest state and a second state wherein the finger flexes outwardly away from the axis when acted upon by a sufficient force, and the finger returns toward its at rest state when the force is reduced or removed from the finger. When a second shaft is partially inserted into a first shaft, an object may engage and flex the finger until the object passes by the finger whereupon the finger may return toward the at rest state partially overlapping the object.

TECHNICAL FIELD

The present disclosure relates generally to a retainer for rotating members, such as rotating shafts in a vehicle drive unit.

BACKGROUND

A vehicle driveline transmits torque from an engine or motor to one or more wheels. Automotive drivelines sometimes include rear or front drive units, and power transfer units (PTUs, also known as power take-off units) for selectively distributing torque among shafts in the driveline. Two shafts of the PTU or other driveline device may need to be coupled together and the relative axial movement of the shafts constrained by a coupler. Packaging in automotive drivelines, as elsewhere in automobiles, often demands inflexible size constraints which can frustrate or prevent installation of the shafts and any coupler on the shafts, or require a coupler of a size and shape that may be damaged (e.g. plastically deformed or broken) during installation. Further, some connections are done blind, that is, the area of the connection between the shafts is not accessible or visible during assembly. This may be due to, for example, components that surround or enclose all or part of an area outboard of the connection between the shafts.

SUMMARY

In at least some implementations, a retainer for coupling rotating shafts includes a body and a finger. The body may have a curved section extending in a circumferential direction about an axis and a pair of ends. The finger extends from the body and has a least a portion that extends inwardly toward the axis. The finger may be flexible and resilient and have an at rest state and a second state wherein the finger flexes outwardly away from the axis when acted upon by a sufficient force, and the finger returns toward its at rest state when the force is reduced or removed from the finger.

In at least some implementations, an assembly includes a first shaft, a second shaft and a retainer. The first shaft has an axis of rotation, an outer surface defining an outer diameter, a cavity defining an inner surface that defines an inner diameter of the first shaft and a groove having at least a portion open to the cavity. The second shaft has an axis of rotation and at least a portion with an outer diameter smaller than the inner diameter so that said at least a portion can be at least partially received within the internal cavity. And the retainer may have a c-shaped body that includes a curved section received in the groove and a finger having a least a portion that extends inwardly toward the axis and projects into the cavity beyond the inner surface of the first shaft. The finger may be flexible and have an at rest state when not acted upon by a force sufficient to flex the finger and a second state wherein the finger flexes outwardly away from the axis when acted upon by a sufficient force. The finger may further be resilient so the finger returns toward its at rest state when the force is reduced or removed from the finger.

DETAILED DESCRIPTION

Referring in more detail to the drawings,FIG. 1illustrates a portion of a rear drive unit10for a vehicle driveline. The rear drive unit10includes an outer housing12that defines at least part of an interior14in which interconnected ends of a first shaft16and a second shaft18are received, and which may include a clutch including a plate pack and the like that cooperate with the shafts16,18to provide a desired coupling and rotation of the shafts. While the following description will focus on the rear drive unit shown, the various concepts, features and combinations of features may be applied to other driveline components, including but not limited to, front drive units, power transfer units and the like, and other assemblies with coupled rotating shafts.

The outer housing12may be adapted to be joined to another housing component in an assembly and thus, might not define a complete enclosure by itself. In the example shown, the housing12is generally bowl or bell shaped with a narrower first end20and a wider second end22. The first end20may include a passage24in which the first shaft16may be journalled for rotation such as by one or more bearings26received between the housing12and first shaft16. The second end22may have a mounting face28adapted to be sealed and connected to an adjacent housing. The mounting face28may circumferentially surround the interior14, and the second shaft18may protrude from the housing12so that it may be coupled to an adjacent driveline component like a spool shaft, a differential or the like. The passage24is open to the interior14and may be considered to define part of the interior of the housing12.

In the implementation shown and as noted above, the rear drive unit10includes the first shaft16that is coupled to the second shaft18to transmit rotation among the shafts. The first shaft16may include a generally tubular main body30and a flange32connected to the main body30. The main body30may be hollow defining an interior surface34and an exterior surface36, and adapted for rotation about a central axis38. To facilitate and guide rotation of the first shaft16, one or more bearings26may be provided. In the example shown, a roller bearing26is provided with an outer race40engaged with the housing12, an inner race42engaged with the exterior surface36of the main body30and a plurality of roller elements43(e.g. balls) between the races. The outer race40may be trapped axially between a shoulder or stop surface44of the housing12and a first retainer clip46. Similarly, the inner race42may be received against a second retainer clip50received in a groove48. In the example shown, the bearing26is inserted into the passage24from the direction of the second end22of the housing12toward the first end20of the housing until the bearing26abuts the shoulder44which is axially opposed to the direction of insertion of the bearing. Thereafter, the first retainer clip46is installed to retain the position of the bearing26relative to the housing12.

Next, the first shaft16is installed, again in the direction from the housing second end22to the housing first end20, with a first end52of the main body30received through the inner race42. Finally, the second retainer clip50may be installed on the main body30from a direction opposite to the direction of installation of the main body30relative to the bearing26. In other words, the second retainer clip50may be inserted into the passage24through the first end20of the housing12and installed into the groove48on the first shaft16. In this way, the axial position of the bearing26and the first shaft16are maintained relative to the housing12and each other.

The main body30may be arranged to receive a drive shaft56at the first end52of the main body30. The drive shaft56may be attached in any suitable way to the first shaft16including arrangements engaging the exterior surface or interior surface or both, of the first shaft. In the implementation shown, the main body30includes internal splines58and the drive shaft56may have complementary splines60extending outwardly from an outer surface thereof to mate with the main body for co-rotation of the drive shaft56and first shaft16. The main body30may be open at both ends (i.e. the first end52and a second end62), with the drive shaft56received in and coupled to the first end52and the second shaft18coupled to the second end62. One or more projections64may be provided in the area of the second end62to receive and locate an adjacent component, as will be set forth in more detail below. As shown inFIGS. 2 and 4, in one embodiment the projection64includes one or more tabs or an annular shoulder defining an axially facing stop surface66(FIG. 4) extending inwardly from the interior surface34of the first shaft16.

The first shaft16may also include or be coupled with the flange32that extends radially outwardly from the main body30. In other words, the flange32may be formed integrally from and in the same piece of material as the main body30or the flange32may be separately formed from the main body30and later attached to the main body (e.g. by welding, fasteners or otherwise) for co-rotation with the main body about the axis38. The flange32may have an outer diameter that is greater than the diameter of the passage24. Hence, the flange32is received within the larger interior cavity14and the first shaft16is installed in the direction noted above, from the second end22toward the first end20of the housing12. The flange32may be of any desired size and shape. In the example shown, the flange32has a generally frustoconical or tapered base68coupled to the main body30and a generally flat or planar outer section70oriented in a plane that is perpendicular (or within 20 degrees of perpendicular) to the axis38.

The flange32may be coupled to friction clutch72that couples together the first shaft16and second shaft18. In the example shown, the friction clutch72includes a multi-plate clutch pack and the flange32is coupled to an outer plate or outer disc carrier74that surrounds the friction plates. In this way, the carrier74is coaxially arranged with the first shaft16and coupled to the first shaft for rotation with the first shaft. The carrier74could be formed integrally with the flange32or it may be coupled thereto in any desired way. The outer carrier74includes inwardly extending teeth76that are adapted to engage outwardly extending teeth on the clutch plates (not shown). The friction plate may also have teeth adapted to engage outwardly extending teeth78on an inner plate or inner disc carrier80. In the example shown, the inner disc carrier80is formed as part of or otherwise coupled to the second shaft18for co-rotation with the second shaft. The inner disc carrier80may be annular and have an inner surface82opposite the teeth78and, at least in some implementations, of a diameter larger than the other diameter of the first shaft16. A support84may extend between the second shaft18and one side of the inner carrier80to couple the inner carrier to the second shaft18. The support84may include a plate, or one or more fingers of material extending between the shaft and inner carrier (i.e. it may be solid or include voids, as desired). The support84, inner carrier80and second shaft18may all be formed from the same piece of material, or they may be separately formed from two or more pieces of material that are joined together during or after their formation. The other side of the inner carrier80may be open providing a cup-shaped or concave section. In this way, at least part of the inner carrier80may axially overlap and radially surround part of the first shaft16, including the second end62of the first shaft16.

The inner carrier80may also axially overlap and radially surround part of the second shaft18, in the example shown, a first end86of the second shaft18. The first end86may be defined by or include a projection88that extends axially beyond or outwardly relative to the support84. The projection88may have an outer diameter smaller than the inner diameter of the second end62of the first shaft16, so that the projection88may be at least partially received within the second end of the first shaft. A second end90of the second shaft18may extend outwardly from the housing12to be coupled with another driveline component, such as, but not limited to, a spool shaft or a differential. The second shaft18could instead be the input shaft and thereby drive the first shaft and an output shaft coupled to the first shaft. In the example shown, the second shaft18, other than the support84and projection88, may be of generally constant diameter, and that diameter may be greater than the diameter of the projection, if desired.

The second shaft18may be journalled for rotation at its first end by a bearing92that may be received between the first shaft16and second shaft18to mutually journal the second end62of the first shaft16and the first end86of the second shaft18, and permit relative rotation between the first shaft16and second shaft18. That is, because the first shaft16is coupled to the outer carrier74and the second shaft18is coupled to the inner carrier80, the first shaft and second shaft may rotate at different speeds. Further, one shaft may be held against rotation while the other shaft rotates. Instead of the clutch72, the first and second shafts16,18may be selectively coupled together by a gear train, such as a planetary gear set arranged between them so that the shafts16,18rotate together when the gear train is actuated and relative rotation is permitted between the shafts when the gear train is not actuated.

In at least some implementations, the bearing92is received within the second end62of the first shaft16, and around the projection88or first end86of the second shaft18. The bearing92is therefore annular, and as shown inFIG. 2, includes an outer race94adjacent to the interior surface34of the first shaft16, an inner race96adjacent to the outer surface of the projection88and a plurality of balls or other intermediate elements98between the races94,96to permit relative movement of the races. In this way, the outer race94rotates with the first shaft16and the inner race96rotates with the second shaft18. To position the bearing92relative to the second shaft18, the second shaft18may include a stop surface or shoulder100, which may also be defined by a retainer such as a c-shaped clip on the shaft, that limits the extent to which the bearing92may be received on the projection88. The inner race96may be pressed onto, otherwise friction fit, adhered or welded to the second shaft18to retain the bearing on the second shaft18, or a retainer such as a c-clip may be provided on the shaft18to inhibit or prevent removal of the bearing from the projection. In this way, the bearing92may be retained on the second shaft18with little or no axial movement permitted between them.

The position of the bearing92relative to the first shaft16may be controlled by the stop surface66in the interior of the first shaft16and a retainer102that is coupled to the first shaft16. Insertion of the bearing92into the first shaft16is limited by engagement of the outer race94with the stop surface66. Movement of the bearing92in the opposite direction, which would remove the bearing92from the first shaft16, is prevented by engagement of the bearing with a portion of the retainer102. In this regard, the retainer102includes a portion that extends inwardly from a surface of the first shaft16toward the axis38of the first shaft16.

In at least some implementations, the retainer102includes a body104and a finger106. The body104may have a curved section108extending in a circumferential direction about an axis110and a pair of ends112,114. To facilitate installation of the retainer102onto the first shaft16, the ends112,114may be spaced apart or separate so that the body104is generally C-shaped. To facilitate retention of the retainer102on the first shaft16, the body104may extend circumferentially between the ends112,114more than 180 degrees. The body104has an inner surface116facing toward the axis110and having a width in the axial direction, and an outer surface118facing away from the axis110also having a width in the axial direction. The body104may have a forward facing surface120and an opposite, rearward facing surface122that extend between the inner surface116and outer surface118and define a radial thickness of the body. The forward and rearward facing surfaces120,122may be oriented parallel to a plane124that is perpendicular or nearly perpendicular (i.e. within 10 degrees) to the axis110. The forward facing surface120may be oriented closer to and facing the second end62of the first shaft16in assembly.

The finger106may be carried by and cantilevered from the body104. In this way, the finger106may have a base126coupled to the body104and the finger extends from the body to a distal or free end128spaced from the body. At least a portion of the finger106extends inwardly toward the axis110, and may extend inwardly so that it is closer to the axis110than the inner surface116of the body104. The finger106may be flexible and have an at rest state and a second state wherein the finger is flexed or bent outwardly away from the axis110when acted upon by a sufficient force during assembly. The finger106may also be resilient (and not significantly plastically or permanently deformed during assembly of the second shaft) so that the finger returns automatically to or at least partially toward its at rest state when the force is reduced or removed from the finger. The finger106and body104may be formed from the same piece of material or the finger may be formed separately from the body and coupled thereto, such as by a fastener, bonding, adhering or welding. In at least some examples, the retainer102is formed from a stamped metal or a molded plastic or composite material.

Like the body104, the finger106may have a forward facing surface130and an opposite, rearward facing surface132that extend between an inner surface134and outer surface136and define a radial thickness of the finger. The forward facing surface130may be oriented closer to and facing the second end62of the first shaft16in assembly. As shown inFIGS. 2 and 6, the forward facing surface130may include at least a portion138that is inclined relative to the axis110. The inclined portion138may be oriented at an angle α to the forward facing surface130(e.g. at an angle to a plane that is perpendicular to the axis110) of between 15 and 75 degrees, as shown between a line137extending from the face of the inclined portion138and a line139extending from the forward facing surface130of the finger. In this example, the forward facing surface130is parallel to (and axially offset from) the forward facing surface120of the body, but it need not be. The inclined portion138may extend from a) the base126, or b) a location between the base126and the free end128to the free end128of the finger106and may extend from the forward facing surface130toward the rearward facing surface132so that the axial dimension of the finger106decreases toward the free end128or tip of the finger106. In at least some implementations, at least part of the finger106is arranged at an included angle β of between zero and 60 degrees relative to a line140tangent to the base126of the finger106. In the example shown, the angle is drawn between the line140and a line142extending from the forward facing surface of the finger. Also in at least some implementations, a portion of the finger106may be at least 3 mm closer to the axis110than the inner surface116of the curved section108of the body104.

Further, in at least some implementations, the inclined portion138could be beveled or tapered in a radial direction. In such an arrangement, the radial dimension of the finger106increases from the forward facing surface130to the rearward facing surface132and an object that engages the finger106at or near the forward facing surface and is moved toward the rearward facing surface of the finger106tends to radially outwardly displace the finger106to facilitate axial movement of the object past the finger.

In at least some implementations, the body104may include an extension144that extends axially from the curved section108and interconnects the finger106and the curved section108. The extension144may extend axially away from the rearward facing surface122of the curved section108(i.e. in the direction that the forward facing surface faces). This positions at least part of the finger106axially forward of at least part of the curved section108of the body104. Doing so may facilitate retention of the curved section108in the groove54of the first shaft16that is spaced axially from the second end62of the first shaft16, while permitting the finger106to be closer to, even with or forward of the second end62.

As shown inFIGS. 1-4 and 7, the first shaft16may include a retention feature formed in or defining part of the exterior surface36and adapted to maintain the retainer102in a desired position on the first shaft. In at least some implementations, the retention feature includes the groove54that extends radially inwardly from the exterior surface36of the first shaft16to a depth sufficient to receive and retain the body104of the retainer102between opposed axially facing shoulders146. The groove54may extend along all or part of the circumference of the first shaft16and may be generally complementary to the shape of the retainer102. In other words, the groove54may have an axial width slightly larger than the axial dimension of the curved section108to axially locate the retainer102on the first shaft16. The inner diameter or dimension of the retainer102may be close to the outer diameter of the base of the groove so that the retainer, in at least some implementations, is firmly received within the groove, is not loosely received in the groove54and does not have radial play that may interfere with the location or function of the finger as set forth herein. In at least some implementations, the retainer102may be sized so that it resiliently flexes when installed in the groove54, and the distance between the ends increases slightly in the installed state compared to the at rest state.

Further, to accommodate the extension144, an axially extending slot150(FIGS. 3, 4 and 7) may be formed in the first shaft16that connects with the groove54. In the example shown, the slot150extends to the second end62of the first shaft16while the groove54is axially spaced from the second end62. Further, at least a portion of the slot150is formed or defines an opening extending axially through the first shaft16and is open to the interior of the first shaft16. In assembly, the curved section108of the retainer102is received within the groove54, the retainer extension144is received axially in the slot150and the finger106may be received in or adjacent to the slot150and extends inwardly toward the axis38of the first shaft. So arranged, the free end128of the finger106is closer to the axis38than is the interior surface34of the first shaft16at the second end62of the first shaft. Thus, the finger106partially blocks part of the open area of the second end62of the first shaft16, and in that way, defines a minimum radial dimension for an object to be inserted in to the first shaft. In other words, an object having an outer diameter closely matched the inner diameter of the second end62will engage the finger106upon insertion into the first shaft16.

In the example shown, the outer race94of the bearing92on the second shaft18engages the finger106and flexes the finger (generally radially outwardly) to permit the bearing92to pass the finger106. In more detail, the bearing92may engage the inclined portion138of the finger106to facilitate flexing of the finger out of the way of the bearing92as the bearing is axially inserted into the first shaft16. When the bearing92has been moved axially past the finger106, the finger may return to or toward its at rest or unflexed state whereupon a portion of the finger radially overlaps part of the bearing92. The unflexing or return movement of the finger106may occur automatically due to the resilient properties of the material of the finger/retainer. In this way, the rearward facing surface132of the finger106confronts the bearing92and inhibits or prevents removal of the bearing from the first shaft16. The rearward facing surface132may define a retaining surface and be generally radially oriented (i.e. not inclined) and is thereby perpendicular or nearly so to axial movement of the bearing92so that engagement of the bearing with the finger106in the removal direction does not tend to radially outwardly flex the finger. The bearing92may be further axially retained and located by engagement with the projection(s)64on the interior surface34of the first shaft16. Hence the bearing92may be definitively located between the finger106and projection(s)64, and firmly retained within the first shaft16.

Further, the flexing and unflexing of the finger106may occur automatically as the second shaft18is inserted into the first shaft16. This facilitates accurately coupling of the shafts16,18even when access to the mating ends62,86of the shafts is obscured or covered. In the example shown, the area around the second end62of the first shaft16is covered or enclosed by one or more other structures. In assembly, the inner carrier80, support84, second shaft18and flange32prevent access to the second end62of the first shaft16so that a retainer (e.g. a clip) to couple together the first and second shafts16,18cannot be installed after the second shaft18is inserted into the first shaft16. Of course, the retainer102as described herein could also be used in implementations wherein access to the second end62of the first shaft16is not prevented, to facilitate assembly or for other reasons.

Another implementation of a driveline component with a retainer160is shown inFIGS. 8-13. Although other driveline components can be used as noted above, this implementation shows a similar rear drive unit10as inFIGS. 1-7. Accordingly, only the differences between the implementations will be described with regard to the arrangement shownFIGS. 8-13. To further simplify the further discussion, the same reference numbers will be used to denote the same or similar components.

As shown inFIGS. 8 and 9, the bearing92is retained on the second shaft18by a clip162instead of or in addition to an interference fit. Next, instead of being received in a groove54in the outer surface36of the first shaft16, the retainer160is received at least partially within a groove164(FIGS. 10 and 12) formed in the interior surface34of the first shaft16. The groove164may include annular or partially circumferential shoulders165defined by a depth of the groove and extending to a base167located radially outwardly from the interior surface34of the second end62of the first shaft16. The groove164may have a constant axial width, and/or constant radial depth, or other shape, as desired to receive and hold the retainer160.

In at least some implementations, the retainer160, as best shown inFIG. 11, includes a body166and a finger168. The body166may have a curved section170extending in a circumferential direction about an axis172and a pair of ends174,176. To facilitate installation of the retainer160into the groove164in the first shaft16, the ends174,176may be spaced apart or separate so that the body is generally C-shaped and may be compressed to reduce its outer diameter for insertion into the second end62of the first shaft16. To facilitate retention of the retainer160in the groove164, the body166may extend circumferentially between the ends174,176more than 180 degrees (end176may be defined at or by a base of the finger as set forth below). The body166has an inner surface178facing toward the axis172and having a width in the axial direction, and an outer surface180facing away from the axis172also having a width in the axial direction. The body166may have a forward facing surface182and an opposite, rearward facing surface184that extend between the inner surface178and outer surface180and define an axial thickness of the body which may, in at least some implementations, be closely matched to the axial dimension of the groove164to limit axial movement of the retainer160relative to the first shaft16. The forward and rearward facing surfaces182,184may be oriented in a plane that is perpendicular or nearly perpendicular (i.e. within 10 degrees) to the axis172. The forward facing surface182may be oriented closer to and facing the second end62of the first shaft16.

The finger168may be carried by and cantilevered from the body166. In the implementations shown inFIGS. 8-13, the finger168is an extension of the body166and is circumferentially aligned with the body. That is, there is no axially extending extension to axially offset the finger from the body, although there could be if desired. In this way, the finger168may have a base186coupled to the body166and the finger extends from the body to a distal or free end187(the end of the finger could also, in at least some implementations, be considered to be the end of the body166). At least a portion of the finger168extends inwardly toward the axis172, and may extend inwardly so that it is closer to the axis than the inner surface178of the body166. The finger168may be flexible and have an at rest state and a second state wherein the finger is flexed or bent outwardly away from the axis172when acted upon by a sufficient force. The finger168may also be resilient so that the finger returns automatically toward its at rest state when the force is reduced or removed from the finger. The finger168and body166may be formed from the same piece of material or the finger may be formed separately from the body and coupled thereto, such as by a fastener, bonding, adhering or welding. In at least some examples, the retainer160is formed from a stamped metal or a molded plastic or composite material.

Like the body166, the finger168may have a forward facing surface190and an opposite, rearward facing surface192that extend between the inner surface178and outer surface180and define a radial thickness of the finger168. The forward facing surface190may be oriented closer to and facing the second end62of the first shaft16in assembly. As shown inFIGS. 9 and 11-13, the forward facing surface190may include at least a portion194that is inclined relative to the axis172. The inclined portion194may be oriented at an angle γ away from the forward facing surface190(e.g. at an angle to a plane that is perpendicular to the axis172), which in at least some implementations may be between 15 and 75 degrees. In the example shown, the angle γ is shown between a line173extending from the forward facing surface182of the body and a line175extending from the inclined portion194. The inclined portion194may extend from a) the base186, or b) a location between the base and the free end188, to the free end188of the finger168and may extend from the forward facing surface190toward the rearward facing surface192so that the axial dimension of the finger decreases toward the free end or tip of the finger. In at least some implementations, at least part of the finger106is radially inclined or bent at an included angle δ (FIGS. 11 and 13) of between zero and 60 degrees relative to a line196tangent to the base186of the finger168and the line173. Also in at least some implementations, a portion of the finger168may be at least 2 mm closer to the axis172than the inner surface178of the curved section170of the body166.

Further, in at least some implementations, the inclined portion194could be beveled or tapered in a radial direction. In such an arrangement, the radial dimension of the finger168increases from the forward facing surface190to the rearward facing surface192and an object that engages the finger at or near the forward facing surface and is moved toward the rearward facing surface of the finger tends to radially outwardly displace the finger to facilitate axial movement of the object past the finger. In the implementations shown, the object is a bearing92coupled to or otherwise carried by the second shaft18and used to journal for rotation the second end62of the first shaft16and the first end86of the second shaft18.

In the example shown, the outer race94of the bearing92on the second shaft18engages the finger168and flexes the finger (generally radially outwardly into the groove) to permit the bearing to pass the finger. In more detail, the bearing92may initially engage the inclined portion194of the finger168to facilitate flexing of the finger out of the way of the bearing as the bearing is axially inserted into the first shaft16. When the bearing92has been moved axially past the finger168, the finger may return to or toward its at rest or unflexed state whereupon a portion of the finger radially overlaps part of the bearing. The unflexing or return movement of the finger168may occur automatically due to the resilient properties of the material of the finger/retainer. In this way, the rearward facing surface192of the finger168confronts the bearing92and inhibits or prevents removal of the bearing from the first shaft16. The rearward facing surface192may define a retaining surface and be generally radially oriented (i.e. not inclined) and is thereby perpendicular or nearly so to axial movement of the bearing so that engagement of the bearing with the finger does not tend to radially outwardly flex the finger. The bearing92may be further axially retained and located by engagement with the projection(s)64on the inner surface34of the first shaft16. Hence the bearing may be definitively located between the finger and projection(s), and firmly retained within the first shaft.

Further, the flexing and unflexing of the finger may occur automatically as the second shaft is inserted into the first shaft. This facilitates accurately coupling of the shafts even when access to the mating ends of the shafts is obscured. In the example shown, the area around the second end of the first shaft is covered or enclosed by one or more other structures as set forth above with respect to the retainer102. Of course, the retainer160as described herein could also be used in implementations wherein access to the second end of the first shaft is not prevented, to facilitate assembly or for other reasons.

As shown inFIGS. 14 and 15, a retainer200may include more than one inwardly extending finger, with two fingers202shown on the illustrated retainer200. Each finger202may be defined at an end of the C-shaped retainer200and the fingers202may be mirror images of each other. The retainer200may be constructed similarly to the retainer102with the fingers202including the same features and functions of the finger106. Thus, the fingers may each include an inclined portion204engaged by the component being inserted into the first shaft16and an opposite retaining surface206that overlies the component after insertion. Likewise, the first shaft may be constructed to accommodate both fingers202.

Similarly,FIGS. 16 and 17illustrate a retainer220having two fingers222. Each finger222may be defined at an end of the C-shaped retainer220and the fingers222may be mirror images of each other. The retainer220may be constructed similarly to the retainer160with the fingers222including the same features and functions of the finger168. Thus, the fingers222may each include an inclined portion224engaged by the component being inserted into the first shaft16and an opposite retaining surface226that overlies the component after insertion.

While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. For example, the retainer may have more than one finger, such as a finger adjacent to each end of the retainer. Each finger may extend inwardly and may function in the manner described with regard to the fingers noted herein. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive, rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention.