TECHNICAL FIELD

[0001] This disclosure relates generally to clutches and in particular to clutches having multiple modes of engagement with a rotating element for selectively locking the element against rotation and allowing the element to rotate freely in one or both directions.

BACKGROUND

[0002] An automotive vehicle typically includes an internal combustion engine containing a rotary crankshaft configured to transfer motive power from the engine through a driveshaft to turn the wheels. A transmission is interposed between engine and driveshaft components to selectively control torque and speed ratios between the crankshaft and driveshaft. In a manually operated transmission, a corresponding manually operated clutch may be interposed between the engine and transmission to selectively engage and disengage the crankshaft from the driveshaft to facilitate manual shifting among available transmission gear ratios.

[0003] On the other hand, if the transmission is automatic, the transmission will normally include an internal plurality of automatically actuated clutch units adapted to dynamically shift among variously available gear ratios without requiring driver intervention. Pluralities of such clutch units, also called clutch modules, are incorporated within such transmissions to facilitate the automatic gear ratio changes.

[0004] In an automatic transmission for an automobile, anywhere from three to ten forward gear ratios may be available, not including a reverse gear. The various gears may be structurally comprised of inner gears, intermediate gears such as planet or pinion gears supported by carriers, and outer ring gears. Specific transmission clutches may be associated with specific sets of the selectable gears within the transmission to facilitate the desired ratio changes.

[0005] Because automatic transmissions include pluralities of gear sets to accommodate multiple gear ratios, the reliability of actuators used for automatically switching clutch modules between and/or among various available operating modes is a consistent design concern. It is also desirable to provide smooth transitions between the operating modes when the clutch modules engage and disengage from the gears. These considerations are also important in other operating environments where selectable clutch modules may be implemented to selectively allow and restrict the rotation of rotating components such as gears, shafts, torque converter components and the like. Therefore, much effort has been directed to finding ways to assure actuator reliability and seamless performance at competitive costs.

SUMMARY OF THE DISCLOSURE

[0006] In one aspect of the present disclosure, an actuator device for a selectable clutch module having a plurality of mode positions for controlling relative rotation between two components connected by the selectable clutch module is disclosed. The actuator device may include an actuator housing defining an interior space extending longitudinally there through, a first fluid passage intending inwardly from an exterior surface of the actuator housing and intersecting the interior space proximate a first axial end, and a second fluid passage extending inwardly from the exterior surface of the actuator housing and intersecting the interior space proximate a second axial end. The actuator device may further include a piston disposed within the interior space for longitudinal motion therein. The piston of the actuator device may further include an inner piston portion being disposed between the first fluid passage and the second fluid passage. Additionally a first outer piston portion may be positioned radially exterior to the inner piston portion and the first outer piston portion may circumferentially surround a portion of the inner piston portion. Furthermore, the piston of the actuator device may further include a second outer piston portion positioned radially exterior to the inner piston portion and axially spaced from the first outer piston portion. The second outer piston portion may circumferentially surround a portion of the inner piston portion. The actuator device may further include a first hydraulic pressure supplied to the first fluid passage to generate a first force acting on a first end of the piston and a second hydraulic pressure supplied to the second fluid passage to generate a second force acting on a second end of the piston, wherein the first force and the second force are selectively applied to move the piston to activate the desired mode of the plurality of modes of the selectable clutch module.

[0007] In another aspect of the present disclosure, a selectable clutch module is disclosed. The selectable clutch may include an outer race, an inner race rotatable relative to the outer race, a selective locking mechanism having a plurality of locking modes for controlling relative rotation between two components connected by the selectable clutch, and an actuator cam that is rotatable between a plurality of mode positions each causing the selective locking mechanism to engage one of the plurality of locking modes. The selectable clutch module may further include an actuator device operatively connected to the actuator cam to move the selective locking mechanism between the plurality of mode positions as a piston moves longitudinally within an interior space of an actuator housing. Moreover, the actuator device of the selectable clutch may further include a first fluid passage extending inwardly from an exterior surface of the actuator housing and intersecting the interior space proximate a first axial end, and a second fluid passage extending inwardly from the exterior surface of the actuator housing and intersecting the interior space proximate a second axial end. The actuator device of the selectable clutch module may further include an inner piston portion being disposed between the first fluid passage and the second fluid passage. Moreover, a first outer piston portion may be positioned radially exterior to the inner piston portion and the first outer piston portion may circumferentially surround a portion of the inner piston portion. The actuator device of the selectable clutch module may further include a second outer piston portion positioned radially exterior to the inner piston portion and axially spaced from the first outer piston portion and the second outer piston portion may circumferentially surround a portion of the inner piston portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a perspective cross-sectional view of a portion of an exemplary

embodiment of a selectable clutch module, in accordance with the present disclosure;

[0009] Fig. 2 is an enlarged side view of a portion of the selectable clutch module of Fig. 1, the selectable clutch module is actuated according to one operational mode, in accordance with the present disclosure;

[0010] Fig. 3 is an enlarged side view of a portion of the selectable clutch module of Fig. 1, the selectable clutch module is actuated according to another operational mode, in accordance with the present disclosure;

[0011] Fig. 4 an enlarged side view of a portion of the selectable clutch module of Fig. 1, the selectable clutch module is actuated according to yet another operational mode, in accordance with the present disclosure;

[0012] Fig. 5 is a cross-sectional view taken through line 5— 5 of Fig. 2 of an embodiment of an actuator device in accordance with the present disclosure in position to place the actuator cam in the a mode of operation, in accordance with the present disclosure; [0013] Fig. 6 is a cross-sectional view taken through line 6— 6 of Fig. 3 of the embodiment of the actuator device in position to place the actuator cam in another mode of operation, in accordance with the present disclosure;

[0014] Fig. 7 is a cross-sectional view taken through line 6-6 of Fig. 3 of another embodiment of the actuator device in position to place the actuator cam in another mode of operation, in accordance with the present disclosure;

[0015] Fig. 8 is a cross-sectional view taken through line 7— 7 of Fig. 4 of the embodiment of the actuator device in position to place the actuator cam in yet another mode of operation, in accordance with the present disclosure;

[0016] Fig. 9 is a cross-sectional view of the selectable clutch module illustrating an exemplary positioning of the actuator device, in accordance with the present disclosure; and

[0017] Fig. 10 is a top view of the selectable clutch module illustrating another exemplary positioning of the actuator device, in accordance with the present disclosure.

DETAILED DESCRIPTION

[0018] In accordance with the present disclosure, a selectable clutch, such as a multimode clutch module, may be implemented at various locations of a vehicle (not shown) to provide multiple modes for connecting and disconnecting rotatable components to prevent or allow, respectively, relative rotation between two components. Referring to Fig. 1, a selectable clutch module 20 of a vehicle may be of the type illustrated and described in Intl. Publ. No. WO 2014/120595 Al, published on August 7, 2014, by Papania, entitled "Multi-Mode Clutch Module," which is expressly incorporated by reference herein. While the selectable clutch module 20 is illustrated and described herein, those skilled in art will understand that actuator devices in accordance with the present disclosure may be implemented with other types of selectable clutches providing multiple modes for connecting and disconnecting rotatable components to prevent or allow, respectively, relative rotation between two components, and the use of the actuator device with such selectable clutches is contemplated by the inventors.

[0019] In the illustrated embodiment, the selectable clutch module 20 may incorporate an interior driven hub 22 and an outer housing 24 that may be locked for rotation together in some modes of the selectable clutch module 20 and may be unlocked for independent rotation with respect to each other in other modes of the selectable clutch module 20 as will be described more fully below. The driven hub 22 may contain an array of circumferentially spaced cogs 26 adapted to secure an inner race 28 to the driven hub 22 for rotation therewith. As disclosed, the inner race 28 is comprised of first and second spaced plates 28A and 28B. An outer race 30 sandwiched between the pair of inner race plates 28A, 28B, is situated so as to allow for relative rotation between inner race 28 and the outer race 30, and with the outer race 30 being operatively coupled to the outer housing 24 for rotation therewith.

In the present design of the selectable clutch module 20, an actuator cam 32 is interposed between one of the race plates 28 A, 28B and the outer race 30 for rotation over a

predetermined angle about a common axis of the driven hub 22 and the outer housing 24 to control movements of pairs of opposed pawls 34, 36 as will be described further hereinafter. The sets of pawls 34, 36 are trapped, and hence retained, between the inner race plates 28A, 28B to allow limited angular movements of the pawls 34, 36 held within bowtie shaped apertures 38, 40, respectively, subject to the control of the actuator cam 32. In each set, the combined pawl 34 and corresponding aperture 38 is similar to but oppositely oriented to the combined pawl 36 and corresponding aperture 40. The elements of the selectable clutch module 20 are contained within the outer housing 24. A plurality of spaced apertures 42 are adapted to accommodate rivets (not shown) for providing fixed and rigid securement of each of the two inner race plates 28A and 28B relative to the other.

[0020] The operational components of the selectable clutch module 20 in Figs. 2-4illustrate the various operational modes of the selectable clutch module 20 for controlling the relative rotation between the components attached to the driven hub 22 and the outer housing 24. Referring first to Fig. 2, the outer race 30 is configured to accommodate interactions with the pawls 34, 36 by providing the inner circumference of the outer race 30 with circumferentially spaced notches 44, each defined by and positioned between pairs of radially inwardly projecting cogs 46. The notches 44 and cogs 46 are configured so that, in the absence of the actuator cam 32, a toe end 48 of each pawl 34 enters one of the notches 44 and is engaged by the corresponding cog 46 when the driven hub 22 and the inner race 28 rotate in a clockwise direction as viewed in Fig. 2 relative to the outer housing 24 and the outer race 30 to cause the connected components to rotate together. Similarly, a toe end 50 of each pawl 36 enters one of the notches 44 and is engaged by the corresponding cog 46 when the driven hub 22 and the inner race 28 rotate in a counterclockwise direction relative to the outer housing 24 and the outer race 30 to cause the connected components to rotate together.

[0021] Within its interior periphery, the actuator cam 32 incorporates a strategically situated array of circumferentially spaced recesses, herein called slots 52, defined by and situated between projections, herein called cam teeth 54. The slots 52 and cam teeth 54 are adapted to interact with the pawls 34, 36 to control their movement within the apertures 38, 40, respectively, and disposition within the notches 44 and engagement by the cogs 46 as will be described. The actuator cam 32 may further include an actuator tab 56 or other

appropriate member or surface that may be engaged by an actuator device 58 that is capable of causing the actuator cam 32 to move through its rotational range to the positions shown in Figs. 2-4. The actuator device 58 may be any appropriate actuation mechanism capable of moving the actuator cam 32, such as a hydraulic actuator as illustrated and described below. The actuator device 58 may be operatively coupled to the actuator cam 32 and capable of rotating the actuator cam 32 to multiple positions. The actuator tab 56 may include a radially extending slot 60 that receives a cam actuator bar 62 extending from a longitudinally extending slot 64 of the actuator device 58. The cam actuator bar 62 may transmit forces from the actuator device 58 to rotate the actuator cam 32 in the clockwise and

counterclockwise directions. The interconnection between the actuator cam 32 and the actuator device 58 is illustrative, and alternative arrangements and linkages facilitating conversion of translational motion of the actuator device 58 into rotational motion of the actuator cam 32 to shift between a plurality of available clutch modes are contemplated and will be apparent to those skilled in the art. In the illustrated embodiment, the actuator tab 56 may be disposed within a slot 66 through the outer race and the rotation of the actuator cam 32 may be limited by a first limit surface 68 engaging the actuator tab 56 at the position shown in Fig. 2 and a second limit surface 70 engaging the actuator tab 56 at the position shown in Fig. 4.

[0022] The pawls 34, 36 are asymmetrically shaped, and reversely identical. Each of the opposed pawls 34, 36 is movably retained within its own bowtie-shaped pawl aperture 38, 40, respectively, of the inner race plates 28A and 28B. The toe end 48, 50 of each individual pawl 34, 36, respectively, is urged radially outwardly via a pawl spring 72. Each pawl spring 72 has a base 74, and a pair of spring arms 76 and 78. The spring arms 76 bear against the bottoms of the pawls 34, while the spring arms 78 bear against the bottoms of the pawls 36, each to urge respective toe ends 48, 50 into engagement with the cogs 46 of the outer race 30 when not obstructed by the cam teeth 54 of the actuator cam 32. It will be appreciated from Fig. 2 that axially extending rivets 80 are used to secure the inner race plates 28A, 28B together. The rivets 80 extend through the apertures 42 in each of the plates 28A, 28B to hold the two plates 28A, 28B rigidly together, and to thus assure against any relative rotation with respect to the plates 28 A, 28B. In lieu of the rivets 80, other structural fasteners may be employed within the scope of this disclosure to secure the inner race plates 28A, 28B.

It will be appreciated that the actuator device 58 ultimately controls the actuator tab 56 which, in turn, moves the actuator cam 32 between multiple distinct angular positions. Thus, the positioning of the pawls 34, 36 as axially retained between the riveted inner race plates 28A, 28B is directly controlled by the actuator cam 32 against forces exerted on the pawls 34, 36 by the springs 72. In Fig. 2, the actuator tab 56 is shown positioned by the actuator device 58 in a first, angularly rightward selectable position, representative of a first, one-way locked, one-way unlocked or open mode. In this position, the slots 52 and cam teeth 54 of the actuator cam 32 are positioned so that the toe ends 48 of the pawls 34 are blocked by cam teeth 54 from engagement with notches 44, and hence with the cogs 46 on the interior of the outer race 30. As such, the inner race 28 is enabled to freewheel relative to the outer race 30, and to thus provide for an overrunning condition when the inner race 28 and the driven hub 22 are rotating clockwise relative to the outer race 30 and the outer housing 24. Conversely, however, the position of the actuator cam 32 allows of the toe ends 50 of the pawls 36 to enter the slots 52 of the actuator cam 32 due to the biasing force of the spring arms 78, and to thereby directly engage the cogs 46 of the outer race 30 to lock the inner race 28 and the outer race 30 together whenever the inner race 28 and the driven hub 22 undergo a driving, or counterclockwise rotational movement, thereby causing the driven hub 22 and the outer housing 24 to rotate together.

[0023] Fig. 3 illustrates the actuator tab 56 placed by the actuator device 58 in a second, intermediate selectable position, representative of a two-way unlocked or open mode of the selectable clutch module 20. In this position, the slots 52 and the cam teeth 54 of the actuator cam 32 are positioned to prevent the toe ends 48, 50 of both pawls 34, 36 from entering the slots 52 of the actuator cam 32, and to maintain disengagement from the cogs 46 of the outer race 30. With the pawls 34, 36 blocked from engagement with the cogs 46, the inner race 28 and the driven hub 22 are enabled to freewheel relative to the outer race 30 and the outer housing 24 during relative rotation in either the clockwise or the counterclockwise direction. In Fig. 4, the actuator tab 56 is shown in a third, angularly leftward selectable position, representative of a two-way locked mode of the selectable clutch module 20. In this configuration, the actuator cam 32 is positioned so that the toe ends 48, 50 of both pawls 34, 36enter the slots 52 of the actuator cam 32 under the biasing forces of the spring arms 76, 78, respectively, and are engaged by the cogs 46 of the outer race 30 as described above to lock the inner race 28 and the driven hub 22 to the outer race 30 and the outer housing 24 for rotation therewith, irrespective of the rotational direction of the inner race 28 and the driven hub 22.

[0024] Even though one specific embodiment of the selectable clutch module 20 is illustrated and described herein, those skilled in the art will understand that alternative configurations of multimode clutches and other selectable clutches are possible that provide operational modes or positions as alternatives or in addition to two-way unlocked and two- way locked modes (Figs. 3 and 4), and the one-way locked, one-way unlocked mode (Fig. 2). For example, an additional one-way locked, one-way unlocked mode that may provide for an overrunning condition when the inner race 28 and the driven hub 22 are rotating counter clockwise relative to the outer race 30 and the outer housing 24, and to lock the inner race 28 and the outer race 30 together whenever the inner race 28 and the driven hub 22 undergo a clockwise rotational movement so the driven hub 22 and the outer housing 24 rotate together.

[0025] Figs. 5 -8 illustrate an exemplary embodiment of the actuator device 58 in a cross- sectional view. The actuator device 58 may include an actuator housing 82 having an interior space 84 extending inwardly into the actuator housing 82, the interior space 84 configured to longitudinally extend between a housing first axial end 86 and a housing second axial end 88 positioned opposite the housing first axial end 86. Furthermore, the interior space 84 may include several transitions of an inner diameter as the interior space 84 longitudinally extends between the housing first axial end 86 and the housing second axial end 88. One non- limiting benefit of configuring the interior space 84 of the actuator housing 82 with several inner diameters is to accommodate various internal components of the actuator device 58; however additional benefits are possible. As such, the interior space 84 may include a first chamber 90 having a first inner diameter 92 of the actuator housing 82, a second chamber 94 having a second inner diameter 96 of the actuator housing 82, and a center portion 98 having a third inner diameter 100 of the actuator housing 82. In the illustrated embodiment, the center portion 98 is disposed between the first chamber 90 and the second chamber 94 and positioned approximately in the center of the interior space 84. Moreover, the first and second inner diameters 92, 96 of the respective first and second chambers 90, 94 may be substantially the same size as one another. The third inner diameter 100 may be smaller than each of the first inner diameter 92 and the second inner diameter 96; however alternative configurations of the interior space 84 are possible. [0026] In some embodiments, the center portion 98 is formed from a first housing shoulder 102 extending inwardly into the interior space 84 from a first lateral side 104 and a second housing shoulder 106 extending inwardly into the interior space 84 from a second lateral side 108 opposite of the first lateral side 104. Moreover, the third inner diameter 100 may be measured between an interior surface of the first housing shoulder 102 and the second housing shoulder 106. The actuator device 58 may further include one or more fluid passages extending the actuator housing 82 into the interior space 84. In one non-limiting example, a first fluid passage 110 may extend through at least one of the first and second lateral sides 104, 108 of the actuator housing 82 such that the exterior of the actuator housing 82 is fluidly coupled with the first chamber 90 of the interior space 84. A second fluid passage 112 may extend through at least one of the first and second lateral sides 104, 108 of the actuator housing 82 such that the exterior of the actuator housing 82 is fluidly coupled with the second chamber 94 of the interior space 84. The first fluid passage 110 and the second fluid passage 112 may be configured for connection to conduits (not shown) from fluid sources (not shown) of the vehicle for providing hydraulic fluid to the first chamber 90 and the second chamber 94, respectively. As discussed further below, one or both of the first and second fluid passages 110, 112 may be coupled or otherwise connected to pressurized fluid sources providing hydraulic fluid with varying pressures to control the operation of the actuator device 58 and, correspondingly, the selectable clutch module 20.

[0027] The actuator device 58 may further include a piston 114 disposed within the interior space 84 and the piston 114 is configured to slide back and forth in the longitudinal direction within the interior space 84. Additionally, the piston 114 may be further configured to include a first outer piston portion 116, a second outer piston portion 118 and an inner piston portion 120. The first outer piston portion 116 may be radially exterior to the inner piston portion 120 and the first outer piston portion 116 may circumferentially surround at least a portion of the inner piston portion 120. Similarly, the second outer piston portion 118 may be radially exterior to the inner piston portion 120, and the second outer piston portion 118 may circumferentially surround at least a portion of the inner piston portion 120. Furthermore, each of the outer piston portions 116, 118 may have an outer piston outer diameter 122 that is only slightly less than the first inner diameter 92 of the first chamber 90 and the second inner diameter of the second chamber 94 such that the first and second outer piston portions 116, 118 are adjacently positioned to the inner surface of the first and second lateral sides 104, 108. As a result, the first and second outer piston portions 116, 118 may slide within the first and second chambers 90, 94, respectively, without leakage of hydraulic fluid there between. If necessary, appropriate seals (not shown) may be provided at the interface between the first and second outer piston portions 116, 118 and the inner surface of the first and second lateral sides 104, 108 to further prevent leakage of hydraulic fluid.

[0028] The inner piston portion 120 may be configured with several transitions of an outer diameter. For example, the inner piston portion may have an inner piston first diameter 124, an inner piston second diameter 126, and an inner piston third diameter 128; however other diameter transitions are possible. The inner piston first diameter 124 may be slightly smaller than an outer piston inner diameter 130 of the first and second outer piston portions 116, 118 such that the each axial end of the inner piston portion 120 is adjacently positioned to the inner surface of the respective first and second outer piston portion 116, 118. As a result, the inner piston portion 120 may slide longitudinally relative to the first and second outer piston portion 116, 118 without leakage of hydraulic fluid there between. If necessary, appropriate seals (not shown) may be provided at the interface between the inner piston portion 120 and the first and second outer piston portion 116, 118 to further prevent leakage of hydraulic fluid. Additionally, the inner piston portion 120 may include a cam bar slot 132 configured to couple or otherwise mate with the cam actuator bar 62 (Figs. 2-4).

[0029] Moreover, the inner piston second diameter 126 may be larger than the inner piston first diameter 124 and the inner piston second diameter 126 is configured to define a piston shoulder 134 that extends radially outward from the surface of the inner piston portion 120. Furthermore, the piston shoulder 134 circumferentially surrounds a portion of the inner piston portion 120. In one non-limiting example, the piston shoulder 134 defines an annular structure that corresponds with the center portion 98 of the actuator housing 82. As such, the inner piston second diameter 126 may be slightly smaller than third inner diameter 100 of the actuator housing 82 such that the surface of the piston shoulder 134 is adjacently positioned to the inner surface of the center portion 98 of the actuator housing 82. Furthermore, actuator housing 82 and the inner piston portion 120 may be configured such that a small leak is formed between the inner piston second diameter 126 and the third inner diameter 100 of the actuator housing 82. In some embodiments, the small leak between the inner piston second diameter 126 and the third inner diameter 100 of the actuator housing 82 provides a leakage pathway to prevent hydraulic locking of the actuator device 58.

[0030] The inner piston third diameter 128 may be smaller than both of the inner piston first and second diameters 124, 126. In one non-limiting example, the inner piston third diameter 128 defines an inner piston stop 136 at each axial end of the inner piston portion 120. In one non-limiting example, the inner piston stop 136 engages or otherwise interacts with the housing first and second axial ends 86, 88 as the piston 114 longitudinally slides within the interior space of the actuator housing 82.

[0031] The actuator device 58 may further include a first actuator spring 138 and a second actuator spring 140. The first actuator spring 138 may be positioned within the first chamber 90 and compressed or otherwise disposed between the first axial end 86 of the actuator housing 82 and the first outer piston portion 116. The second actuator spring 140 may be positioned within the second chamber 94 and compressed or otherwise disposed between the second axial end 88 of the actuator housing 82 and the second outer piston portion 118. As a result, the first and second actuator springs 138, 140 may each provide a spring force FS that biases the piston 114, including the first outer portion 116, the second outer portion 118, and the inner piston portion 120, within the actuator housing 82. The first actuator spring 138 may exert the spring force FS to bias the first outer piston portion 116 and the inner piston portion 120 towards the right and the second actuator spring 140 may exerts the spring force FS to bias the second outer piston portion 118 and the inner piston portion 120 towards the left. The magnitude of the spring force FS of the first and second actuator spring 138, 140 is equal to kX, where k is the spring constant for the first and second actuator spring 138, 140 and X is the amount of compression of the first and second actuator spring 138, 140.

[0032] As shown in Fig. 5, the actuator device 58 is illustrated in cross-sectional view taken through line 5-5 of Fig. 2, and the actuator device 58 is actuated consistent with an operational first mode of the selectable clutch module 20. The position of the piston 114, and more specifically, the positions of the first outer piston position 116, the second outer piston portion 118, and the inner piston portion 120 will be dictated by a first pressure PI at the first fluid passage 110, a second pressure P2 at the second fluid passage 112, and the amount of compression of the first and second actuator springs 138, 140. In the illustrated embodiment, the position of the second outer piston portion 118, the inner piston portion 120, the cam actuator bar 62 and, correspondingly the actuator cam 32 (Fig 2) will be dictated by the first pressure PI at the first fluid passage 110, the second pressure P2 at the second fluid passage 112, and the amount of compression of the second actuator spring 140.

[0033] In the present example, the first pressure PI and the second pressure P2 are control pressures that may be varied by controlling an output pressure of a pressurized hydraulic fluid source (not shown) in fluid communication with the first and second fluid passage 110, 112. The first pressure PI is controlled to supply a greater pressure than the second pressure P2 such that pressurized hydraulic fluid is supplied to the first chamber 90 to move the piston 114 and the cam actuator bar 62 consistent with the operational first mode of the selectable clutch module 20. The pressurized hydraulic fluid in the first chamber 90 interacts with the first outer portion 116 and the inner piston portion 120 to exert a first pressure force Fl on the piston. Furthermore, the pressurized hydraulic fluid in the second chamber 94 interacts with the second outer portion 118 and the inner piston portion 120 to exert a second pressure force F2. The force Fl acts on a surface area Al of the first outer piston portion 116 and a surface area A2 of the inner piston portion 120 causing the piston to longitudinally slide to the right. Movement of the piston by force Fl causes the first outer piston portion 116 to engage with a first outer piston stop surface 142 of the first and second housing shoulder 102, 106. Such engagement may restrict further movement of the first outer piston portion 116 to the right. Additionally, force Fl causes the second outer piston portion 118 and the inner piston portion 120 to move away from a second outer piston stop surface 144 of the first and second housing shoulder 102, 106. In some embodiments, the second outer piston portion 118 and the inner piston portion 120 will continue to move to the right until the inner piston stop 136 engages the second axial end 88 of the actuator housing 82. Alternatively, the second outer piston portion 118 and the inner piston portion 120 will continue to move to the right until the second pressure P2 and spring force FS of the second actuator spring become equal or greater than force F 1.

[0034] As illustrated in Fig. 5, the piston 114 and cam actuator bar 62 are moved to the right with the first outer piston portion 116 engaged by the first outer piston stop surface 142 of the first and second housing shoulder 102, 106 and the inner piston stop 136 engaged by the second axial end 88 of the actuator housing 82. In this position, the cam actuator bar 62 has moved the actuator cam 32 to the operational first mode position shown in Fig. 2. The force equation for this position may be expressed as Fl > F2 + FS. Holding the first pressure PI constant, or increasing the first pressure PI, will maintain the piston 114 at the right limit position and keep the selectable clutch module 20 in the first mode.

[0035] When a controller (not shown) of the vehicle detects that the selectable clutch module 20 should move to a second mode such as that shown in Fig. 3, the controller may cause the pressurized hydraulic fluid source to reduce the first pressure PI or increase the second pressure P2 such that the first pressure PI and the second pressure P2 are equal. As a result, the force Fl acts on a surface area Al of the first outer piston portion 116 and a surface area A2 of the inner piston portion 120 and the force F2 acts on a surface area A2 of the second outer piston portion 118 and a surface area A4 of the inner piston portion 120. When the force equation changes to Fl + FS = F2 + FS, the force Fl and F2 may cancel each other out causing the piston 114 and the cam actuator bar 62 to longitudinally slide towards the middle of the actuator housing 82 consistent with the operational second mode of the selectable clutch module 20.

[0036] Alternatively, when the controller (not shown) of the vehicle detects that the selectable clutch module 20 should move to the second mode, as shown in Fig. 3, the controller may cut off or otherwise stop the flow of pressurized hydraulic fluid to the first and second fluid flow passage 110, 112. As illustrated in Fig. 7, the first pressure PI and second pressure P2 may be low enough such that hydraulic fluid flows out of the first and second chamber 90, 94. As a result, the force Fl may equal the spring force FS of the first actuator spring 138 and the force F2 may equal the spring force FS of the second actuator spring 140. In one non-limiting example, the first and second actuator spring 138, 140 have the same spring constant kX. As a result, the piston 114 and cam actuator bar 62 longitudinally slide towards the middle of the actuator housing consistent with the operational second mode of the selectable clutch module 20.

[0037] As illustrated by the position of the actuator device58 of Figs. 6 and 7, the first outer piston portion 116 has moved into engagement with the first outer piston stop surface 142 of the first and second housing shoulder 102, 106 and the second outer piston portion 118 has moved into engagement with the second outer piston stop surface 144 of the first and second housing shoulder 102, 106. Additionally, the inner piston portion 120 is moved into a centered position within the actuator housing 82 such that the piston shoulder 134 is aligned with the first and second housing shoulder 102, 106. In this position, the cam actuator bar 62 has moved the actuator cam 32 to the operational second mode position shown in Fig. 3. The force equation for this position may be expressed as Fl +FS = F2 + FS. Generally, the actuator device 58 is configured such that the first and second actuator spring 138, 140 produce an equal amount of spring force FS on the piston 114. As a result, maintaining the first pressure PI and the second pressure P2 at an equal and constant pressure will maintain the piston 114 at the centered position within the actuator housing 82 and keep the selectable clutch module 20 in the second mode.

[0038] When a controller (not shown) of the vehicle detects that the selectable clutch module 20 should move to a third mode such as that shown in Fig. 4. As such, the first pressure PI and the second pressure P2 are control pressures that may be varied by controlling the output pressure of the pressurized hydraulic fluid source (not shown) in fluid communication with the first and second fluid passage 110, 112. The second pressure P2 is controlled to supply a greater pressure than the first pressure PI such that pressurized hydraulic fluid is supplied to the second chamber 94 to move the piston 114 and the cam actuator bar 62 consistent with the operational third mode of the selectable clutch module 20. The pressurized hydraulic fluid in the second chamber 94 interacts with the second outer portion 118 and the inner piston portion 120 to exert a second pressure force F2 on the piston 114. Furthermore, the pressurized hydraulic fluid in the first chamber 90 interacts with the first outer piston portion 116 and the inner piston portion 120 to exert a first pressure force Fl . The force F2 acts on a surface area A3 of the second outer piston portion 118 and a surface area A4 of the inner piston portion 120 causing the piston 114 to longitudinally slide to the left. Movement of the piston by force F2 causes the second outer piston portion 118 to engage with the second outer piston stop surface 144 of the first and second housing shoulder 102, 106. Such engagement may restrict further movement of the second outer piston portion 118 to the left. Additionally, force F2 causes the first outer piston portion 116 and the inner piston portion 120 to move away from the first outer piston stop surface 142 of the first and second housing shoulder 102, 106. In some embodiments, the first outer piston portion 116 and the inner piston portion 120 will continue to move to the left until the inner piston stop 136 engages the first axial end 86 of the actuator housing 82. Alternatively, the first outer piston portion 116 and the inner piston portion 120 will continue to move to the left until the first pressure PI and spring force FS of the first actuator spring 138 become equal or greater than force F2.

[0039] As illustrated in Fig. 8, the piston 114 and cam actuator bar 62 are moved to the left with the second outer piston portion 118 engaged by the second outer piston stop surface 144 of the first and second housing shoulder 102, 106 and the inner piston stop 136 engaged by the first axial end 86 of the actuator housing 82. In this position, the cam actuator bar 62 has moved the actuator cam 32 to the operational third mode position shown in Fig. 4. The force equation for this position may be expressed as F2 > Fl + FS. Holding the second pressure P2 constant, or increasing the second pressure P2, will maintain the piston 114 at the left limit position and keep the selectable clutch module 20 in the third mode.

[0040] Referring now to Figs. 9 and 10, two exemplary embodiments of the selectable clutch module 20 including the actuator device 58 are illustrated. In the embodiment of Fig. 9, the actuator device 58 is positioned in a radially exterior position to the selectable clutch module 20. In one embodiment, the actuator device 58 may be placed in a radially outward position with respect to the outer race 30 and outer housing 24 (Fig. 1). Moreover, a first end of the cam actuator bar 62 may be fixedly attached to the piston 114 of the actuator device 58. In one non-limiting example, the first end of the cam actuator bar 62 is inserted into the cam bar slot 132 and fixedly attached to the inner piston portion 120 with an attachment device 146 such as but not limited to a screw, bolt, pin, or other such device. A second end of the cam actuator bar 62 is fixedly attached to the actuator cam 32 of the selectable clutch module 20. As a result, actuating the piston 114 of the actuator device 58 may be selectably controlled to actuate the actuator cam 32 into a plurality of positions consistent with the desired operational mode of the selectable clutch module 20.

[0041] Alternatively, in the embodiment of Fig. 10, the actuator device 58 is positioned axially along the axis A-A of the selectable clutch module 20. In one embodiment, a first end of the cam actuator bar 62 may be fixedly attached to the piston 114 of the actuator device 58. Furthermore, the first end of the cam actuator bar 62 may be inserted into the cam bar slot 132 formed in the inner piston portion 120. The cam actuator bar 62 may be fixedly attached to the inner piston portion 120 using the attachment device 146 (i.e., screw, bolt, or pin). The cam actuator bar 62 may extend axially along axis A-A such that the second end of the cam actuator bar 62 is fixedly attached to the actuator cam 32 of the selectable clutch module 20. As a result, actuating the piston 114 of the actuation device 58 may be selectably controlled to actuate the actuator cam 32 into a plurality of positions consistent with the desired operational mode of the selectable clutch module 20. In the embodiment shown, the actuator device 58 is positioned axially exterior or interior to the selectable clutch module 20 and the actuator device 58 is orientated such that the longitudinal axis of the actuator device 58 is perpendicular to the axis A-A of the selectable clutch module 20.

[0042] Alternatively, in an embodiment, the actuator device 58 is positioned axially exterior or interior to the selectable clutch module 20 and the actuator device 58 may be orientated such that the longitudinal axis of the actuator device 58 is parallel to the axis A-A of the selectable clutch module 20. As such, the cam actuator bar 62 and other such components of the actuator device 58 and selectable clutch module 20 may be modified, as needed, to translate the linear motion of the piston 114 to the rotational motion of the actuator cam 32. INDUSTRIAL APPLICABILITY

[0043] In general, the selectable clutch module of the present disclosure may be applied in a variety of industrial applications, including but not limited to, automobiles, trucks, vans, off-road vehicles, agriculture equipment, construction equipment and the like. More specifically, the selectable clutch module may be incorporated with combustion engines, transmissions, and drivelines of such equipment.

[0044] The actuator device 58 in accordance with the present disclosure may eliminate the need for a position sensor to provide feedback to the selectable clutch module control strategy configured to monitor the position of the actuator cam 32, the cam actuator bar 62, and the piston 114, while still allowing for precise control of the actuator device. The actuator device 58 includes a piston 114 disposed within the interior space 84 of the actuator housing 82. Moreover, pressurized hydraulic fluid is delivered to one, both, or neither side of the piston 114 in order to move the piston within the interior space 84 of the actuator housing 82.

[0045] In the first actuation mode illustrated in Fig. 5, the pressurized hydraulic fluid is delivered to the first fluid passage 110. The hydraulic fluid acts on the surface area of the first outer piston portion 116 and first axial end of the inner piston portion 120 to cause the piston 114 to move towards the right. In the second actuation mode illustrated in Fig. 6, the pressurized hydraulic fluid is delivered to both the first fluid passage 110 and the second fluid passage 112. As a result, the hydraulic fluid acts on the surface area of the first outer piston portion 116 and first axial end of the inner piston portion 120 and the surface area of the second outer piston portion 118 and second axial end of the inner piston portion 120.

Applying the pressurized hydraulic fluid to each side of the piston 114 will move the piston to the center of the interior space 84 of the actuator housing. Alternatively, the second actuation mode may be achieved by removing the pressurized hydraulic fluid from each of the first fluid passage 110 and the second fluid passage 112, as shown in Fig. 7. The actuator device 84 includes first and second actuator springs 138, 140 that are positioned between the first and second axial ends of the piston 114 and first and second axial ends of the actuator housing 82. As such, once the pressurized hydraulic fluid is removed from each fluid passage, the springs will move the piston towards the center of the actuator housing 82. In some embodiments, the use of pressurized hydraulic fluid at the first and second fluid passage 110, 112 will provide a quicker response time in moving the piston to the center position. Additionally, in the third actuation mode illustrated in Fig. 8, the pressurized hydraulic fluid is delivered to the second fluid passage 112. The hydraulic fluid acts on the surface area of the second outer piston portion 118 and second axial end of the inner piston portion 120 to cause the piston 114 to move towards the left.

[0046] While the preceding text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of protection is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the scope of protection.

[0047] It should also be understood that, unless a term was expressly defined herein, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to herein in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning.