Continuous velocity joint having disconnect arrangement

Abstract

To provide a continuous velocity joint assembly comprising a rotatable input part and a rotatable output part.SOLUTION: A continuous velocity mechanism that allows transfer of power between an input part and an output part while allowing angular variation is also provided. A disconnect arrangement has first and second portions which can rotate relative to one another in a disconnected state and cannot rotate relative to one another in a connected state. An electromechanical actuator causes the disconnect arrangement to shift between the disconnected state and the connected state. In the disconnect arrangement, power is transferred between the input part and the output part in the connected state and power is not transferred between the input part and the output part in the disconnected state.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] This application is based on and claims priority to U.S. Provisional Patent Application No. 63 / 540,840, entitled "Continuous Velocity Joint Having Disconnect Capability," filed September 27, 2023, and U.S. Provisional Patent Application No. 63 / 541,134, entitled "Continuous Velocity Joint Disconnect With Flanged Interface," filed September 28, 2023. Both of the above-referenced patent applications are hereby incorporated by reference in their entireties for all purposes.

[0002] The present invention relates generally to a vehicle driveline and, more particularly, to a wheel end disconnect assembly for engaging and disengaging wheels thereof. [Background technology]

[0003] Mechanisms are known for selectively engaging and disengaging drive axles with corresponding vehicle wheels. For example, the basic concept includes mechanisms in which multiple drive axles are continuously or full-time utilized in a driveline. Drivelines that allow drive axles to be engaged and disengaged as needed or desired have become increasingly popular in recent years for various reasons. For example, known mechanisms allow a user to manually engage a vehicle driveline with the wheels, which typically requires the user to exit the vehicle to achieve manual engagement. In addition, automated systems are also known, in which a vehicle control system automatically engages and disengages the driveline with the wheels in a driven state. However, such mechanisms often include numerous intricate components and can therefore be complex and costly to manufacture and even to maintain. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention recognizes and addresses the problems of prior art arrangements and methods. [Means for solving the problem]

[0005] One aspect of the invention provides a continuous velocity joint assembly with a rotatable input and a rotatable output. A continuous velocity mechanism is further provided that allows for the transmission of power between the input and the output while allowing for angular variation. A disconnection arrangement has first and second parts that are capable of rotating relative to one another in a disconnected state and that are not capable of rotating relative to one another in a connected state. An electromechanical actuator transitions the disconnection arrangement between a disconnected state and a connected state, where in the connected state power is transmitted between the input and the output and where in the disconnected state power is not transmitted between the input and the output.

[0006] According to some exemplary embodiments, the electromechanical actuator may comprise a screw type actuator, such as a leadscrew actuator having a leadscrew rotatably driven by an electric motor.

[0007] According to some example embodiments, a state maintenance mechanism may be provided that is operable to maintain the disconnected configuration in at least one of a connected state and a disconnected state when power to the actuator is lost. The state maintenance mechanism may comprise an energy storage element that is operable to move the disconnected configuration to a selected one of the connected state and the disconnected state when power to the actuator is lost. For example, the energy storage element may comprise a torsion spring (e.g., a clock spring) for rotating the lead screw via stored energy. In such embodiments, the state maintenance mechanism may be configured to provide a selectable preload to the torsion spring. In some embodiments, a detent arrangement may be provided to maintain the disconnected configuration in the other of the connected state and the disconnected state when power to the actuator is lost.

[0008] In some exemplary embodiments, the first portion of the disconnection arrangement can comprise an outer housing in which a shaft carrying a plurality of trunnions is received. The second portion of the disconnection arrangement can be axially located adjacent to the outer housing, the disconnection arrangement further comprising a clutch mechanism selectively connecting the first and second portions together in the connected state and disconnecting the first and second portions in the disconnected state. Additionally, the clutch mechanism can comprise a shiftable collar having splines defined on an inner circumference thereof, at least one of the first and second portions having splines on an outer circumference that are slidably engaged by the splines of the shiftable collar. The shiftable collar in such embodiments can define an annular groove about its outer circumference that is engaged by the fork to permit rotation of the collar relative to the fork, but translational movement of the fork causes the collar to move axially.

[0009] In certain example embodiments, the first portion of the disconnect assembly can include an annular member mounted to a rotatable housing in which a shaft carrying a plurality of trunnions is received. The annular member can have a plurality of radial projections spaced about an outer periphery thereof, each of the radial projections defining an axial throughbore in which an elongated fastener is received.

[0010] According to another aspect, the present invention provides a disconnection arrangement for use with a continuous velocity joint. The arrangement comprises first and second parts capable of relative rotation with respect to one another in a disconnected state and not capable of relative rotation with respect to one another in a connected state. The first part is configured to be fixed to an outer housing of the continuous velocity joint. The second part is configured to be connected to a source of rotational power. An actuator is further provided for transitioning the disconnection assembly between the disconnected state and the connected state. As a result, power is transferred between the second part and the first part in the connected state and power is not transferred between the second part and the first part in the disconnected state.

[0011] In some example embodiments, the first portion is configured to be secured to a flange of an outer housing of a continuous velocity joint. The first portion can define a plurality of angularly spaced protrusions that define respective axial through holes, for example, to assist in securing the first portion to the flange of the continuous velocity joint.

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present disclosure and, together with the description, serve to explain the principles of the invention.

[0013] A full and enabling disclosure of this invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in this specification, which refers to the accompanying drawings. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a half shaft assembly according to the prior art. [Diagram 2] FIG. 2 is an enlarged view of one of the continuous velocity joints (CVJs) of the half shaft assembly of FIG. [Diagram 3] FIG. 2 is a schematic diagram illustrating a CVJ with disconnection capability according to an embodiment of the present invention. [Figure 4] FIG. 4 illustrates the embodiment of FIG. 3, further showing an actuator for axially moving the CVJ between a connected and disconnected state. [Diagram 5] FIG. 4 shows the embodiment of FIG. 3 in a disconnected state. [Figure 6] FIG. 4 shows the embodiment of FIG. 3 in a connected state. [Figure 7] FIG. 2 is an isometric view of a CVJ with disconnect capability according to an embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view of the CVJ of FIG. 7, showing certain internal components. [Figure 9] FIG. 8 is an enlarged, partially exploded view showing a portion of the actuator housing of the CVJ of FIG. [Figure 10A] FIG. 1 illustrates actuator components used to achieve a monostable or bistable system. [Figure 10B] FIG. 1 illustrates actuator components used to achieve a monostable or bistable system. [Figure 10C] FIG. 1 illustrates actuator components used to achieve a monostable or bistable system. [Figure 11A] 8 is a disconnect function map illustrating aspects of operation of the CVJ of FIG. 7; [Figure 11B] 8 is a disconnect function map illustrating aspects of operation of the CVJ of FIG. 7; [Figure 12A] 8 is a connectivity map illustrating the manner in which the CVJ of FIG. 7 operates; [Figure 12B]8 is a connectivity map illustrating the manner in which the CVJ of FIG. 7 operates; [Figure 13] 1A-1C are cross-sectional views illustrating embodiments of actuators used to achieve a bistable system. [Figure 13A] FIG. 14 illustrates components of the actuator of FIG. 13. [Figure 13B] FIG. 14 illustrates components of the actuator of FIG. 13. [Figure 14] FIG. 1 is an isometric view of a disconnect assembly for a CVJ having a flanged interface. [Figure 15] FIG. 15 is an exploded view of the disconnect assembly of FIG. 14 showing its various components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the present disclosure.

[0016] Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided as an explanation of the invention, and not as a limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit of the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to yield still further embodiments. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.

[0017] FIG. 1 illustrates, by way of background, a prior art vehicle half shaft assembly 10 that may be modified in accordance with the principles of the present invention. The half shaft 10 includes a first continuous velocity joint (CVJ) 12 and a second continuous velocity joint 14 near each end of the half shaft 10. As is well known, the CVJ 12 (also referred to as a "constant velocity joint") functions to transfer rotation from an input shaft to an output shaft when the angle between the shafts varies within a certain range. In this case, the CVJ 12 is considered an "on-vehicle" CVJ because it is directly connected to a differential, such as via a stub shaft 16. The CVJ 12 transmits torque to an intermediate axle shaft 18, which serves as an input for the CVJ 14. The CVJ 14 is considered an "off-vehicle CVJ" because it is connected, such as via an output stub shaft 20, to the wheels to be driven. CVJs 12 and 14 have respective boots 22 and 24 that extend between their outer housings (or simply "outers") and shaft 18 to allow angular motion while containing lubricant to protect the interior of the CVJ from environmental contaminants.

[0018] 2, the on-vehicle CVJ 12 is typically considered a "plunging CVJ," meaning that it accepts some degree of axial movement relative to the axle shaft 18. A plunging CVJ has a "tripod" 26 having three radially extending trunnions (such as the trunnion shown at 28) spaced at 120° apart that are splined to the axle shaft 18. Each of the trunnions carries a respective barrel-shaped roller bearing that interacts with a CVJ outer 32. The shaft 16 extends from the outer 32 as shown. Thus, rotation of the shaft 16 rotates the outer 32, which in turn rotates the tripod 26 and thus the axle shaft 18. An off-vehicle CVJ can be a tripod CVJ or any other suitable type, but is typically not plunging.

[0019] Embodiments of the present invention provide for the selective interruption of power flowing through a CVJ, which can be either a plunging CVJ or a non-plunging CVJ. This joint can be a stand-alone CVJ or a CVJ integrated into a half shaft (one example of an application of a stand-alone CVJ would be a prop shaft). Some embodiments of the present invention achieve the selective disconnection of power through a CVJ utilizing a two-piece outer, where either piece can rotate independently about the same axis when disconnected, or rotate together when connected.

[0020] The separation point between the two pieces of the CVJ outer can be in a number of different locations, some examples of which are shown in the drawing figures discussed below. A clutch mechanism is provided to selectively transfer power between the two pieces. For example, the two pieces can be selectively coupled utilizing: A transfer ring which is radially splined on one side and selectively axially splined on the other side; A transfer ring which is radially splined on one side and selectively radially splined on the other side; A radially movable flipper which always contacts one side and selectively contacts the other side; Any other suitable clutch mechanisms as necessary or desired.

[0021] Suitable actuators are used to move the transmission components or the radially movable components, such as: Motors, racks and pinions, and forks Motors, leadscrews, and forks Motors, half screws, and forks Plunger type solenoids and forks - Annular solenoid and annular armature. In the case of a solenoid, a bistable solenoid may preferably be used. The solenoid may be made bistable, for example, using a permanent magnet latch system with a spring or a retractable pen type mechanism. These bistable options have the benefit of "failing to state" if power to the actuator is lost. The retractable pen mechanism may also work with a motor-based actuator.

[0022] Lead screw actuator mechanisms traditionally produce assemblies that are naturally stable or naturally unstable with respect to the nut's maintained position when no power is applied to the motor. In this regard, if the screw is designed to be driven backwards, it will not necessarily hold the nut's position in a given state (e.g., engaged, disengaged, or in between). If the screw is not designed to be driven backwards, friction in the lead screw allows the nut to hold its position in any state (e.g., engaged, disengaged, or in between).

[0023] In the case of a disconnection assembly for a drive system, a monostable or bistable system is generally preferred for a system that is always stable. For a monostable system, it may be desirable to have a system that initializes to return to a known state if control or power is lost to the actuator motor. This type of system uses continuous power to hold the actuator in one of two desired states. No power is required to hold the actuator in the other state. For a bistable system, it may be desirable to have a system that will hold either a connected or disconnected state if power is lost to the actuator motor, but will transition to a known state if control or power is lost to the actuator when placing the actuator halfway between connected and disconnected. The benefit of this type of system is that no power is required to hold the actuator in either of these desired states. Certain embodiments of the present invention allow functionality to ensure that the system always "rests" in the connected state if power is removed from the actuator motor.

[0024] 3 and 4 show a CVJ 512 that may utilize an embodiment of the present invention. The CVJ 512, in this case, is assembled into a half shaft assembly having a stub shaft 516 for connection to a source of motive power (e.g., a differential or e-drive unit). The CVJ 512 has a housing ("outer") having a first portion 532a within which the tripod is located and a second portion 532b to which the stub shaft 516 is secured. Those skilled in the art will recognize that a boot extends between the first portion 532a and the axle shaft extending from the tripod. As shown, a collar 550 having axial splines on its inner diameter is located on the outer diameter of the second portion 532b having complementary splines.

[0025] A ball bearing 534 is located on the extension 542 of the second portion 532b. Additionally, a thrust bearing 536 may be located between the axially opposed faces of portions 532a and 532b. The wave spring 552 eliminates any clearance in the assembly that may cause noise from the thrust or ball bearings in the disconnected state.

[0026] 4, the collar 550 is transitioned between the disconnected and connected positions (FIGS. 5 and 6, respectively) using a fork 554 that, in this embodiment, is moved axially by a suitable linear actuator 556, such as a threaded actuator (e.g., a lead screw actuator). As can be seen, the fork is received in an annular groove extending around the circumference of the collar 550, such that the collar 550 can rotate relative to the fork, but the fork can move the collar axially. The collar 550 can include, for example, axial dogs or the like for mating with suitable openings on a flange 558 of the first portion 532a.

[0027] 7 and 8 show a CVJ 612 that is similar to CVJ 512 in many respects. As shown, the CVJ housing ("outer") has a first portion 632a in which the tripod is received. The second portion 632b is configured to rotate with or independently of the portion 632a depending on whether the CVJ 612 is in a connected or disconnected state. In this case, the second portion 632b is configured as a hub for receiving a stub shaft of, for example, a differential or e-drive unit. As shown, the portion 632a has an annular extension portion 660 that is coaxial with the extension portion 642 of the second portion 632b. A pair of ball bearings 634a and 634b are located in the radial space between the extension portions 642 and 660. An additional ball bearing 634c can be located between the inner extension portion of the second portion 632b and a surrounding housing 662 of the CVJ 612. The first portion 632a carries a drum-like wall 664 to separate the area where the tripods are located from the second portion 632b.

[0028] The second portion 632b further has a radial flange 670 having a series of axial splines on its outer periphery. The disconnect collar 650 has splines on its inner periphery that engage with the external splines of the flange 670. An actuator 656, here in the form of a lead screw actuator, moves the fork 672 axially. The fork 672 engages an annular slot in the collar 650, thereby transitioning the collar 650 between the connected and disconnected positions. In the connected position, the collar 650 engages both the first portion 632a and the portion 632b, thereby causing the first portion 632a and the portion 632b to rotate together (i.e., there is no relative rotation). In the disconnected position, the collar 650 is retracted from the second portion 632b. Thus, the first portion 632a can rotate at wheel speed independent of the rotation of the second portion 632b.

[0029] The actuator 656 includes a motor 674 that rotates a lead screw 676. A disconnect fork 672 includes an integral nut portion 678 that moves axially when the lead screw 676 is rotated. The direction of rotation determines whether the nut portion 678 (and the disconnect fork 672 of which the nut portion 678 is a part) moves in a forward or reverse direction. The lead screw 676 is supported for rotation by ball bearings 680a-b, as shown.

[0030] 9 and 10, an embodiment of the present invention provides functionality to ensure that the system always "rests" in the connected (and / or disconnected) state when power is removed from the actuator motor 674. In this regard, a mechanism 682 is provided to bias the system to the connected (and / or disconnected) state when motor power is lost. The mechanism 682 includes a suitable spring that is preferably preloaded to a selected torque required to hold the mechanism in the biased (e.g., connected) state. In this embodiment, the spring includes a suitable torsion spring 684. As shown, a "clock spring" may be utilized for this purpose, as such a spring provides the desired functionality with minimal axial length. In the actuated (disconnected) state, the spring 684 winds from the rotation of the lead screw 676 during actuation, thereby increasing the torque feedback to the system. The actuator motor 674 must maintain power to resist the potential energy stored in the spring 684 in order to return the system to the connected state. (Although the description herein describes a default setting to a connected state, one skilled in the art will recognize that the clock spring may alternatively be reversed to maintain the system in a disconnected state in the event of a power failure.)

[0031] As can be most easily explained with reference to FIG. 9, the mechanism 682 can be configured to allow a user to select a preload. In this embodiment, the mechanism 682 includes a cover 686 configured to engage the spring 684 to preload the spring 684 when the cover 686 is rotated. (Thus, the cover functions as a "crank" or "dial" for the preload.) Once the desired preload torque is achieved, a bolt 688 is threaded into a corresponding hole in the actuator cover 690, thereby setting the spring to this preloaded state. It will be seen that the cover 690 defines a boss 692 within which the spring 684 (or, more precisely, an adapter, which in this embodiment is an extension of the lead screw) is received for engagement with the lead screw 676. The cover 686 closes the open end of the boss 692. As shown, the cover 686 includes a series of angularly spaced recesses 694 that define preload increments. The bolts 688 are each located adjacent a selected one of a pair of diametrically opposed recesses 694 .

[0032] 10A-C, an angular hard stop may be integrated into the mechanism 682 to prevent any instance where the system accidentally locks in a connected state where the lead screw 676 cannot be driven to disconnect. In this case, an adapter 696 including a stop formation 698 is placed at the end of the lead screw 676 to be an integral extension of the lead screw 676. The nut portion 678 itself includes a stop formation 700 that is engaged by the stop formation 698 when the nut portion 678 reaches a desired limit of its outward axial movement. Preferably, the stop formations 698 and 700 will be angularly engaged before the main body of the nut portion 678 axially contacts the adapter 696. A suitable spring arrangement such as a stack of Belleville springs 702 compresses as the nut portion moves axially outward, thereby allowing the nut to move axially without intending to engage the collar if the delta rpm exceeds the requirements of the application.

[0033] According to a preferred embodiment, mechanism 682 may be assembled as follows: (1) lead screw 676 is rotated counterclockwise either manually or by actuator motor 674 until the system is fully actuated and engaged and nut portion 678 is stopped by lead screw stop structure 698; (2) spring 684 and cover 686 are pre-assembled using dowel pin 704 (FIG. 9) to fix the rotation of the outer coil of spring 684 relative to cover 686; (3) the cover / spring subassembly is then inserted into boss 692 and rotated counterclockwise while monitoring the torque to drive the rotation until the desired preload in the spring is achieved; (4) after the desired preload torque is reached, the rotation is held by recess 694 in cover 686 which aligns with the bolt hole in boss 692 and cover 686 is secured in this angular position by bolt 688.

[0034] 11A-B illustrate the functionality of the system from a connected state to a disconnected state according to a preferred embodiment.

[0035] 12A-B illustrate the functionality of the system from a disconnected state to a connected state according to a preferred embodiment.

[0036] The mechanism 682 can provide bi-stable functionality. Referring now to FIG. 13, the nut portion 678' includes an axially extending detent finger 720 that engages a detent defined in a detent ring 722 at the end of the lead thread 676' opposite the adapter 696, thereby integrally forming a detent arrangement 724. In this embodiment, the spring 684 holds the actuator in the connected state. The detent arrangement 724 holds the actuator in the disconnected state after the actuator fully pulls the nut portion 678' back against the torque of the spring 684 toward the actuator motor. The retention strength of the detent mechanism 724 should preferably be sufficient to prevent the spring 684 from disengaging in the presence of shock loads and vibrations (e.g., vehicle vibration). However, the retention strength should not be so strong that it would be impossible for the actuator motor to overcome the locking device to disengage when the system is commanded to move to the connected state. A spring 684 drives the actuator from the intermediate state to the connected state.

[0037] 14 and 15, it is further desirable to provide a disconnect assembly configured to interface with flanged CVJ connections. Such a disconnect assembly may be utilized where it is not feasible to incorporate a disconnect capability into the half shaft assembly at the time of manufacture, or in certain other CVJ applications (e.g., retrofit). The disconnect assembly may be monostable or bistable as described above, may be continuously stable, or may even be inherently unstable depending on the exigencies of the application.

[0038] To this end, Figures 14 and 15 show a disconnect assembly 812 constructed in accordance with an embodiment of the present invention. In this case, the disconnect assembly provides monostable or bistable functionality similar to the above-described CVJ 612. Components of assembly 812 that are similar to components of CVJ 612 will be designated by reference numerals increased by 200.

[0039] The assembly 812 has a first portion 832a configured to be coupled to the "outer" of the CVJ, with which the first portion 832a will be used (and thus its functionality is part of the CVJ outer). In this instance, the first portion 832a includes a series of angularly spaced radial protrusions 950 that define respective through holes 952 that are parallel to the axis of rotation. The protrusions 950 together form a flange interface that will be juxtaposed to a flange of the CVJ. In this regard, the first portion 832a may be secured to the CVJ flange via elongated fasteners (e.g., bolts) that extend through the through holes 952.

[0040] The remaining components may be the same or similar to those described above in connection with FIGS. 7 and 8. In this regard, the second portion 832b is configured to rotate with or independently of the first portion 832a depending on whether the assembly 812 is in a connected or disconnected state. In this case, the second portion 832b is configured as a hub for receiving a stub shaft of, for example, a differential or an e-drive unit. As shown, the portion 832a has an annular extension portion 860 located coaxially with the extension portion 842 of the second portion 832b. A pair of ball bearings, such as bearing 834a, are located in the radial space between the extension portions 842 and 860. An additional ball bearing 834c may be located between the inner extension portion of the second portion 832b and a surrounding housing 862 of the disconnect device 812. The first portion 832a carries a drum-like wall 864 for surrounding the second portion 832b.

[0041] The second portion 832b has a radial flange 870 with a series of axial splines on its outer periphery. A disconnect collar 850 has splines on its inner periphery that engage with the outer splines of the flange 870. An actuator 856, here in the form of a lead screw actuator, moves a fork 872 axially. The fork 872 engages an annular slot in the collar 850, thereby transitioning the collar 850 between a connected position and a disconnected position. In the connected position, the collar 850 engages both the first portion 832a and the portion 832b, thereby causing the first portion 832a and the portion 832b to rotate together (i.e., there is no relative rotation). In the disconnected position, the collar 850 is retracted from the second portion 832b. Thus, the first portion 832a can rotate at wheel speed independent of the rotation of the second portion 832b.

[0042] An actuator 856 includes a motor that rotates the lead screw. A disconnect fork 872 includes an integral nut portion that moves axially when the lead screw is rotated. The direction of rotation determines whether the nut portion (and the disconnect fork 872 of which it is a part) moves in a forward or reverse direction. Annular members 954 and 956 are secured to the first and second portions 832a and 832b, respectively. Members 954 and 956 are intermeshed to provide a convoluted path between the interior of the housing 862 and an area outside the housing 862.

[0043] Although one or more preferred embodiments of the present invention have been described above, those skilled in the art will recognize that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention.

Claims

1. 1. A continuous velocity joint assembly comprising: a rotatable input section and a rotatable output section; a continuous speed mechanism that allows for the transmission of power between the input and output while allowing for angular variation; a disconnection arrangement having first and second parts that are rotatable relative to one another in a disconnected state and that are not rotatable relative to one another in a connected state; an electromechanical actuator for transitioning the disconnected configuration between the disconnected state and the connected state, wherein in the connected state, power is transferred between the input portion and the output portion, and in the disconnected state, power is not transferred between the input portion and the output portion.

2. The continuous velocity joint assembly of claim 1 , wherein the electromechanical actuator comprises a screw type actuator.

3. 3. The continuous velocity joint assembly of claim 2, wherein the screw type actuator comprises a lead screw actuator having a lead screw rotatably driven by an electric motor.

4. 4. The continuous velocity joint assembly of claim 3, further comprising a state maintenance mechanism operable to maintain the disconnected configuration in at least one of the connected state and the disconnected state upon loss of power to the actuator.

5. 5. The continuous velocity joint assembly of claim 4, wherein the state maintenance mechanism comprises a torsion spring operable to rotate the lead screw via energy stored in the torsion spring to move the disconnected configuration to a selected one of the connected state and the disconnected state in the event of a loss of power to the actuator.

6. The continuous velocity joint assembly of claim 5 , wherein said torsion spring comprises a clock spring.

7. The continuous velocity joint assembly of claim 5 , wherein the state maintenance mechanism is configured to provide a selectable preload to the torsion spring.

8. 6. The continuous velocity joint assembly of claim 5, further comprising a detent arrangement for maintaining said disconnected configuration in the other of said connected and disconnected states in the event of a loss of power to said actuator.

9. The continuous velocity joint assembly of claim 1 , wherein the first portion of the disconnect arrangement can comprise an outer housing within which a shaft carrying a plurality of trunnions is received.

10. 10. The continuous velocity joint assembly of claim 9, further comprising a clutch mechanism, the second portion of the disconnecting arrangement being axially adjacent to the outer housing, the disconnecting arrangement selectively connecting the first and second portions together in the connected state and disconnecting the first and second portions in the disconnected state.

11. 11. The continuous velocity joint assembly of claim 10, wherein the clutch mechanism comprises a transitional collar having a spring defined on an inner periphery thereof, and at least one of the first portion and the second portion having splines on an outer periphery thereof that are slidably engaged by splines on the transitional collar.

12. 12. The continuous velocity joint assembly of claim 11, wherein the transitional collar defines an annular groove about its outer periphery that is engaged by the forks such that translational movement of the forks permits rotation of the collar relative to the forks but causes axial movement of the collar.

13. 2. The continuous velocity joint assembly of claim 1, wherein the first portion of the disconnect assembly comprises an annular member mounted in a rotatable housing within which a shaft carrying a plurality of trunnions is received.

14. 14. The continuous velocity joint assembly of claim 13, wherein the annular member has a plurality of radial projections spaced about an outer periphery thereof, each of the radial projections defining an axial throughbore within which an elongated fastener is received.

15. 2. The continuous velocity joint assembly of claim 1, further comprising a state maintenance mechanism operable to maintain the disconnected configuration in at least one of the connected state and the disconnected state upon loss of power to the actuator.

16. 1. A disconnect arrangement for use with a continuous velocity joint, the disconnect arrangement comprising: a first part and a second part that are rotatable relative to one another in a disconnected state and that are not rotatable relative to one another in a connected state; the first portion is configured to be secured to an outer housing of the continuous velocity joint; a first portion and a second portion, the second portion configured to be connected to a source of rotational power; a disconnection configuration comprising: an actuator for transitioning the disconnection assembly between the disconnected state and the connected state, wherein in the connected state power is transmitted between the second part and the first part and in the disconnected state power is not transmitted between the second part and the first part.

17. The disconnect arrangement of claim 16 , wherein the first portion is configured to be secured to a flange of the outer housing of the continuous velocity joint.

18. 20. The disconnect arrangement of claim 17, wherein a first portion defines a plurality of angularly spaced protrusions defining respective axial through holes to assist in securing the first portion to the flange of the continuous velocity joint.

19. The disconnection arrangement of claim 16 , further comprising a state maintenance mechanism operable to maintain the disconnection arrangement in at least one of the connected state and the disconnected state upon loss of power to the actuator.

20. 20. The disconnect arrangement of claim 19, wherein the state maintenance mechanism comprises a torsion spring operable to rotate the lead screw via energy stored within the torsion spring to move the disconnect arrangement to a selected one of the connected state and the disconnected state in the event of a loss of power to the actuator.

21. The disconnect arrangement of claim 20 , wherein the torsion spring comprises a clock spring.

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