DE102017202261B4 - Actuator mechanism for a transfer case - Google Patents

Abstract

A transfer case comprising: a primary output shaft (306); a secondary output shaft (308) connected to a secondary torque transmitting mechanism (351) for transmitting torque from the primary output shaft (306) to the secondary output shaft (308) with the primary output shaft (306) is selectively coupleable; andan actuator comprising: a hub member (394; 494; 594; 694; 794) comprising an annular body (394b; 494b; 594b; 694b; 794b) having a peripheral slot (394c; 494c; 594c; 694c; 794c); a bearing member (498; 598; 698; 798) coupled to the annular body (394b; 494b; 594b; 694b; 794b) and positioned in the slot (394c; 494c; 594c; 694c; 794c) wherein the bearing member (498; 598; 698; 798) includes a bearing surface extending in an axial direction with respect to the annular body (394b; 494b; 594b; 694b; 794b); and a face cam mechanism (370) which, when rotated by the hub member (394; 494; 594; 694; 794), translates to drive the secondary torque transmitting mechanism (351) in the axial direction, the face cam mechanism (370) including a plunger (374a) which is engaged by the bearing member (498; 598; 698; 798) and moves axially along the bearing surface when the face cam is rotated by the hub member (394; 494; 594; 694; 794); 794b) comprises an end wall (394d; 494d; 594d; 694d; 794d) at a circumferential end of the circumferential slot, the bearing member (498; 598; 698; 798) being made of a material that is harder as another material forming the end wall (394d; 494d; 594d; 694d; 794d), and the bearing member exerts a localized force away from the plunger (374a) over the end wall (394d; 494d; 594d; 694d; 794d) distributed; andwherein the bearing member (498; 598; 698; 798) is a bearing segment (498a; 598a; 698a; 798a) forming the bearing surface and a coupling segment (498b; 598b; 698b; 798b, 798c) connected to the annular body (498a; 394b; 494b; 594b; 694b; 794b).

Description

BACKGROUND

In the field of vehicle powertrain components, a transfer case is a device that distributes drive power to more than one driven axle of the vehicle. A typical transfer case receives drive power from the transmission of the vehicle and transmits that power to a primary output shaft, which is continuously driven during operation of the vehicle in a two-wheel drive mode, for example, and a secondary output shaft that is driven using a clutch, for example, during operation of the vehicle a four-wheel drive mode is selectively driven. In addition, two-speed transfer cases provide a speed reduction to operate in a high range, which is typically a drive ratio of 1: 1, or a low range, such as 1: 1. As a drive ratio of 2: 1, to allow. Transfer cases and corresponding actuators for such transfer case or differential gear are, for example, from DE 10 2015 222 146 A1 , of the US 2005/0202919 A1 , of the US 2006/0247082 A1 and the DE 38 15 225 C2 known.

The object is to provide an actuator for a transfer case and a corresponding transfer case with increased wear resistance to cyclic loads. The object is achieved by a transfer case according to claim 1 or an actuator according to claim 12. Further developments of the device according to claim 1 are the subject of the dependent claims.

SUMMARY

A transfer case includes a primary output shaft, a secondary output shaft and an actuator. The secondary output shaft is selectively coupleable to a secondary torque transmitting mechanism for transmitting torque from the primary output shaft to the secondary output shaft to the primary output shaft. The actuator includes a hub member, a bearing member, and a face cam mechanism. The hub member includes an annular body defining a circumferential slot. The bearing member is coupled to the annular body and positioned in the slot. A bearing member includes a bearing surface extending in an axial direction with respect to the annular body. The face cam mechanism shifts upon rotation by the hub member to operate the secondary torque transmitting mechanism in the axial direction. The face cam mechanism includes a plunger that is engaged by the bearing member and moves axially along the bearing surface when the face cam is rotated by the hub member.

The annular body includes an end wall at a circumferential end of the circumferential slot, the bearing member is formed of a material that is harder than another material forming the end wall, and the bearing member can distribute a localized force from the plunger across the end wall. The bearing member includes a bearing segment that forms the bearing surface and includes a coupling segment that is coupled to the annular body. The bearing segment may include a rear surface opposite the bearing surface, the rear surface being engaged with the end wall to distribute a force thereacross. The bearing member may have a cross-sectional profile extending in the axial direction. The bearing member may be coupled to the annular body by at least one fastener or the coupling segment received in a complementary slot of the annular body. The attachment means may be a snap member received in an annular groove in the annular body.

The hub member may be further configured to engage independently of the face cam mechanism in a first range of motion in which the bearing member does not engage the plunger and in a second range of motion in which the bearing member engages the plunger to rotate the face cam mechanism is about to turn. The secondary torque transmitting mechanism may include a disc clutch, and in the second range of motion, the front cam mechanism axially displaces to compress the disc clutch to selectively couple the primary output shaft to the secondary output shaft. The secondary torque transmitting mechanism may include a first sprocket coupled to a housing of the disc clutch to be selectively coupled to the primary output shaft, a second sprocket coupled to the secondary output shaft, and a chain including the first sprocket coupled with the second sprocket for transmitting torque therebetween.

The plunger may be a roller configured to roll along the bearing surface.

The hub member may comprise two slots, each slot defined by two end walls and one of the bearing members thereof coupled to each end wall. The face cam mechanism may include two tappets that are rollers, each tappet positioned in one of the two slots and configured to slide along the turret Bearing surface of each bearing member of the slot in which the plunger is positioned to roll. The transfer case may further include an input shaft and a speed reduction mechanism configured to selectively couple the input shaft between a first drive ratio and a second drive ratio with the primary output shaft. The actuator may be configured to operate the gear reduction mechanism in a first range of motion to selectively couple the input shaft in the first drive ratio or the second drive ratio to the primary output shaft, and the secondary torque transmitting mechanism in a second range of motion extending from the first range of motion different, operate.

The face cam mechanism may include a first cam member and a second cam member. The first cam member is axially fixed with respect to the hub, the plunger is coupled to the second cam member, and the second cam member is rotatable by the hub with respect to the first cam member for axial displacement with respect to the first cam member.

An actuator for a transfer case includes an actuator member, a face cam mechanism, and a motor. The actuator member includes a circumferential slot defined between two end walls formed by an annular body, at least one of the end walls having a bearing member coupled thereto and defining a bearing surface extending in an axial direction with respect to the annular body. The face cam mechanism includes a first cam member, a second cam member and a plunger coupled to the second cam member. The second cam member is configured to axially displace with respect to the first cam member upon rotation with respect to the first cam member, the plunger being disposed in the slot. The motor is configured to rotate the annular body in a first range of motion independent of the face cam mechanism and in a second range of motion in which the bearing member is engaged with the plunger to rotate the second cam member relative to the first cam member and in which Tappet axially along the bearing surface of the bearing member moves to rotate.

The bearing surface is formed of a material that is harder than another material that forms the end wall to which the bearing member is coupled. The bearing member may have a cross-sectional shape extending in an axial direction. The bearing member includes a bearing segment and a coupling segment, wherein the coupling segment is coupled to the annular body and the bearing segment, which forms the bearing surface and a rear surface, is engaged with the end wall. The actuator member and the second cam member may rotate about a common axis.

A transfer case includes a primary output shaft, a secondary output shaft, a torque transmitting mechanism and an actuator. The torque transmitting mechanism selectively couples the primary output shaft to the secondary output shaft for torque transfer therebetween. The actuator includes a face cam, an annular body, a bearing member and an electric motor. The face cam shifts axially upon rotation to operate the torque transmitting mechanism. The face cam includes a plunger extending radially outward. The annular body includes end walls that define a slot extending circumferentially therebetween. The plunger is positioned in the slot. The bearing member is coupled to one of the end walls and extends in an axial direction with respect to the annular body. The bearing member is harder than the end wall. The electric motor rotates the annular body in a first range of motion in which the face cam is stationary, and in a second range of motion in which the bearing member is engaged with the plunger to rotate the face cam and in which the plunger extends axially along the plunger Bearing member moves.

list of figures

• 1 eine Draufsichtsdarstellung, die einen Triebstrang, der ein Verteilergetriebe umfasst, zeigt;
• 2 eine Querschnittsdarstellung, die ein Verteilergetriebe mit einem herkömmlichen Betätigungssystem zeigt;
• 3 eine Querschnittsdarstellung, die ein Verteilergetriebe mit einem Betätigungssystem gemäß einer beispielhaften Ausführungsform zeigt;
• 4 eine perspektivische Ansicht des Betätigungssystems von hinten;
• 5 eine auseinandergezogene Ansicht des Betätigungssystems;
• 6 eine perspektivische Ansicht eines teilweisen Betätigungssystems für ein Verteilergetriebe gemäß einer beispielhaften Ausführungsform;
• 7 eine perspektivische Ansicht eines teilweisen Betätigungssystems für ein Verteilergetriebe gemäß einer weiteren beispielhaften Ausführungsform;
• 8A eine perspektivische Ansicht eines teilweisen Betätigungssystems für ein Verteilergetriebe gemäß einer weiteren beispielhaften Ausführungsform;
• 8B eine Endansicht eines Lagerglieds des in 8A gezeigten Betätigungssystems;
• 9 eine perspektivische Ansicht eines teilweisen Betätigungssystems für ein Verteilergetriebe gemäß einer weiteren beispielhaften Ausführungsform; und
• 10A eine perspektivische Ansicht eines teilweisen Betätigungssystems für ein Verteilergetriebe gemäß einer beispielhaften Ausführungsform; und
• 10B eine Endansicht eines Lagerglieds des in 10A gezeigten Betätigungssystems.

The description refers to the attached drawings in which like reference numbers refer to the same parts throughout the several views; show in it:

• 1 a plan view showing a drive train comprising a transfer case shows;
• 2 a cross-sectional view showing a transfer case with a conventional operating system;
• 3 FIG. 4 is a cross-sectional view showing a transfer case with an actuation system according to an exemplary embodiment; FIG.
• 4 a perspective view of the actuating system from the rear;
• 5 an exploded view of the actuation system;
• 6 a perspective view of a partial actuation system for a transfer case according to an exemplary embodiment;
• 7 a perspective view of a partial actuation system for a transfer case according to another exemplary embodiment;
• 8A a perspective view of a partial actuation system for a transfer case according to another exemplary embodiment;
• 8B an end view of a bearing member of in 8A shown actuating system;
• 9 a perspective view of a partial actuation system for a transfer case according to another exemplary embodiment; and
• 10A a perspective view of a partial actuation system for a transfer case according to an exemplary embodiment; and
• 10B an end view of a bearing member of in 10A shown actuating system.

DETAILED DESCRIPTION

1 is a plan view showing a drive train 100 for a vehicle with four-wheel drive shows. The drive train 100 includes an engine 110 that with a gear 112 is coupled. The engine 110 is the primary drive source of the powertrain 100 and may be, for example, an internal combustion engine, an electric motor / generator or a combination of the two. Other types of power sources may be considered the engine 110 for supplying drive power (eg via a rotating output shaft) to the transmission 112 be used. The gear 112 includes components that can be operated to the speed and torque of the engine 110 converted drive power, such. B. by a gear set that provides multiple gear ratios. For example, the transmission 112 a manual transmission, an automatic transmission, a semi-automatic transmission, a continuously variable transmission or a dual-clutch transmission.

The gear 112 leads a transfer case 120 Drive power too. The transfer case 120 is operable to drive power to a rear drive shaft 130 and a front drive shaft 140 to distribute. The transfer case 120 For example, in some implementations, it may include components that allow the transfer case to perform a mode change between two or more different modes. For example, the transfer case 120 Operating in a rear-drive or two-wheel drive mode, with only the rear drive shaft 130 Drive power receives and the front drive shaft 140 not, and a four-wheel drive mode in which the rear drive shaft 130 and the front drive shaft 140 receive both drive power, allow. In this example, the rear drive shaft 130 the primary drive shaft and the front drive shaft 140 is the secondary drive shaft. In other implementations, the front drive shaft 140 the primary drive shaft and the rear drive shaft 130 is the secondary drive shaft, and the transfer case 120 performs a mode change between a front-drive mode and a four-wheel drive mode. In other implementations, the transfer case includes 120 no components that allow a mode change, and the transfer case 120 leads both the rear drive shaft 130 and the front drive shaft 140 consistently drive power too.

The transfer case 120 may allow a range change, which selectively reduces the rotation output of the transfer case 120 provides. For example, the transfer case components for operation in a high range, such. B. a drive ratio of 1: 1, or a low range, such. B. a drive ratio of 2: 1, include. The change of range changes the operation of the transfer case 120 between the low range and the high range by selectively coupling and decoupling a speed reduction mechanism of the transfer case 120 ,

The operation of the transfer case 120 can by a controller, such. As an ECU, 122 are regulated, the or the components of the transfer case 120 Supplying signals for effecting the mode change and / or the area change. In other implementations, the mode change and / or the range change may be initiated mechanically, such as by changing the mode. B. by a driver-operated lever, with a component of the transfer case 120 mechanically connected.

The rear drive shaft 130 leads a rear axle 150 via a rear axle differential 152 Drive power too. The rear axle 150 may be, for example, a live axle or a pair of independent semi-axles. The rear axle 150 Performs drive power to a pair of rear wheels 154 equipped with tires. The front drive shaft 140 leads a front axle 160 via a front axle differential 162 Drive power too. The front axle 160 may also be, for example, a rigid axle or a pair of independent semi-axles. The front axle 160 leads a pair of front wheels 164 equipped with tires, drive power too.

As in 2 is shown includes the transfer case 200 generally one Gear reduction system or a gear reduction mechanism 210 and a secondary torque transmitting system or a secondary torque transmitting mechanism. The gear reduction system 210 is for selectively transmitting torque at different drive ratios from an input shaft 204 on a primary output shaft 206 configured and operable by a reduction actuation mechanism. The secondary torque transmitting system is for selectively transmitting torque between the primary output shaft 206 (eg, the rear output shaft) and a secondary output shaft 208 (eg, the front output shaft) and is operable by a torque transmitting actuation mechanism. In the following discussion, directional terminology (eg, front, front, rear, rear, etc.) is used, although it refers to an orientation in which the transfer case may be installed in a vehicle (eg is in the in 2 and 3 the cross-sections shown on the left side the front of the transfer case, while the right side is the rear of the transfer case), for reference only, since other attachment orientations of the transfer case are possible.

The transfer case 200 includes a housing 202 and rotating components, including an input shaft 204 , a primary output shaft 206 and a secondary output shaft 208 each from the housing 202 extend out. The input shaft 204 and the primary output shaft 206 extend along a first axis 207 , The secondary output shaft 208 extends along a second axis 209 , which in this example are parallel to the first axis 207 runs. Together form the input shaft 204 , the primary output shaft 206 and the secondary output shaft 208 a power transmission arrangement.

The input shaft 204 is at least partially hollow, and the primary output shaft 206 extends into the hollow interior of the input shaft 204 , The input shaft 204 can either be direct or via a gear reduction mechanism 210 with the primary output shaft 206 be connected. The gear reduction mechanism 210 may be a Ravigneaux planetary gear set, which is a sun gear 212 that on the input shaft 204 is formed, several planetary gears 214 and a ring gear 216 that on the case 202 is fixed. A planet carrier 218 is on the input shaft 204 arranged and can be around the input shaft 204 rotate. The planet wheels 214 are on sidewalks 220 arranged with the planet carrier 218 are connected. The planet wheels 214 comb with the sun wheel 212 and the ring gear 216 ,

A jaw clutch mechanism with a gear reduction hub 222 (eg, dog clutch, coupling, ring) is used to engage and disengage the gear reduction mechanism 210 used. In a first position of the gear reduction hub 222 becomes the gear reduction hub 222 axially forward (ie parallel to the primary output shaft 206 ) for direct engagement with the input shaft 204 and the primary output shaft 206 which produces a drive ratio of 1: 1 and does not use the speed reduction mechanism 210 , In a second position of the gear reduction hub 222 (not shown) becomes the speed reduction hub 222 from the input shaft 204 away axially displaced and instead takes the planet carrier 218 and the primary output shaft 206 engaged. Drive power is thus through the gear reduction mechanism 210 passed, with the planet carrier 218 slower than the input shaft 204 turns to a drive ratio, such. B. 2: 1, manufacture.

The reduction operation mechanism moves the speed reduction hub 222 between her first and her second position. In particular, the speed reduction hub 222 is replaced by a first shift fork 224 moves, moving axially along a switching shaft 226 moved back and forth. A first cam follower 228 is at the first shift fork 224 educated. The first cam follower 228 is in a first groove 230 arranged on an outer surface of a drum cam 232 is trained. The drum cam 232 is on a rotatable shaft 234 arranged by an electric motor 236 in response to control signals from a controller, such. B. the ECU, 122 of 1 is turned.

The secondary torque transmitting mechanism is for transmitting torque from the primary output shaft 206 on the secondary output shaft 208 configured. A first sprocket 250 (eg rotating member) is on the primary output shaft 206 arranged and with the primary output shaft 206 through a disc clutch 252 connected. The second sprocket 254 is on the secondary output shaft 208 is arranged and connected by, for example, splines (not shown) with it for common rotation. The first sprocket 250 and the second sprocket 254 are connected by a chain 256 interconnected so that the secondary output shaft 208 through the primary output shaft 206 over the first sprocket 250 , the chain 256 and the second sprocket 254 is driven when the disc clutch 252 is indented.

The disc clutch 252 generally comprises a housing 252a or a drum, several nested plates 252b , a pressure or actuator plate 252c and an actuator 258 , The casing 252a generally includes a radial base through which the primary output shaft 206 extends, and a concentric or annular flange extending axially from an outer periphery of the base to form a generally cylindrical housing in which the interleaved plates 252b are positioned extends. The base of the case 252a is with the first sprocket 250 coupled to effect rotation thereof while the actuator plate 252c with the primary output shaft 206 (eg, by a spline connection) is coupled to rotate therewith. The nested plates 252b are alternating with the primary output shaft 206 and an inner periphery of the housing 252a engaged (eg splined). The actuator 258 is configured to engage the actuator plate 252c to press the nested plates 252b between the actuator plate 252c and the base of the case 252a to compress the friction between them and torque between them with the primary output shaft 206 splined plates 252b and the splined plates with the housing 252a 252b transferred to. In this way, torque can be selected selectively from the primary output shaft 206 on the first sprocket 250 and ultimately the secondary output shaft 208 be transmitted.

3 is a cross-sectional view of the transfer case 300 shows while 4 - 5 an actuation system 361 of the transfer case 300 individually represent. The transfer case 300 generally includes a gear reduction mechanism 310 (ie with a planetary gear set) and a secondary torque transmitting mechanism 351 (ie with a first sprocket 350 , a disc clutch 352 one with a second output shaft 308 coupled second sprocket 354 and a chain 356 ), the similar components and similar functionality of the speed reduction mechanism 210 and the secondary torque transmitting mechanism previously discussed (not all components are individually marked). The transfer case 300 further comprises an actuation system or an actuation mechanism 361 acting to both the gear reduction mechanism 310 as well as the secondary torque transmitting mechanism 351 to operate. Components and arrangements of the transfer case 300 generally the same and / or a similar function as that of the transfer case 200 are common across designations with common designations and numbering plus 100 (e.g., speed reduction mechanism 210 and gear reduction mechanism 310 ).

Compared to the transfer case 200 are the orientation of the disc clutch 352 and the sprocket 350 the secondary torque transmitting mechanism 351 reversed from front to back, with the actuator plate 352c the disc clutch 352 points forward and the disc clutch 352 even in front of the sprocket 350 is arranged. The actuation system 361 is generally axially between the gear reduction mechanism 310 and the disc clutch 352 positioned. The actuation system 361 takes to operation of the gear reduction mechanism 310 the reduction hub 322 and configured to operate the secondary torque transmitting mechanism 351 the actuator plate 352c the disc clutch 352 to engage.

As in 4 - 5 is shown comprises the actuation system 361 generally an actuator base 362 , a motor 364 with reduction gears 366 , a secondary Drehmomentübertragungsaktuatormechanismus 370 (eg, disk clutch actuator, first actuator mechanism), a speed reduction actuator mechanism 380 (eg jaw clutch actuator, second actuator mechanism) and a drive gear assembly 390 (eg, drive assembly). Generally the engine turns 364 via the reduction gears 366, the drive gear assembly 390 in turn, sequential (ie, serial, step) operation of the speed reduction actuator mechanism 380 and the torque transmission actuator mechanism 370 each stage of rotation generally being one of the actuator mechanisms 370 . 380 assigned. For example, a first stage is the speed reduction actuator mechanism 380 assigned. In the first stage (eg, first or initial movement or rotation range, first positive stage and first negative stage), the drive gear assembly becomes 390 through the engine 364 over the reduction gears 366 rotated (eg, +/- 30-50 degrees from the midpoint, such as 35 degrees) to the gear reduction actuator mechanism 380 to operate the gear reduction hub or coupling 322 moved to the first position (eg, high range at +35 degrees) or the second position (eg, low range at -35 degrees). In a second stage (eg, second, continuing, or subsequent movement or rotation range of first stage ends, second positive stage, and second negative stage), the drive gear assembly becomes 390 through the engine 364 further rotated (eg, +/- an additional 10-30 degrees, such as 25 degrees, ie +35 degrees to +60 degrees and -35 degrees to -60 degrees), the second torque-transmitting actuator mechanism 370 to operate, the pressure on the clutch actuation plate 352c for squeezing the interleaved plates 352b by doing clutch housing 352a exercises. As will be discussed in more detail below, the torque-transmitting actuator mechanism includes 370 and the speed reduction actuator mechanism 380 each cam mechanisms, the feed and / or retraction movement areas and / or bump areas, which in conjunction with the drive gear assembly 390 intended for the stepped operation.

According to further exemplary embodiments, the various stages of operation of the actuator system 361 be configured differently, for example, with other ranges of motion in the first and / or second stages (ie, greater or lesser), other bidirectional ranges for each direction of movement within a given stage (eg, +35 degrees in the first positive stage and -25) Degrees in the first negative stage), overlapping ranges of motion between stages (eg +/- 35 degrees in the first stage and +30 to +60 and -30 to -60 in the second positive and second negative stages), with Gaps between ranges of motion (eg, +/- 30 degrees in the first stage and +35 to +60 and -35 to -60 in the second positive and second negative stages), with additional stages (eg, for Operating other actuator mechanisms) and / or with unidirectional stages associated with one or more of the actuator mechanisms (eg, rotation in only one direction causes operation of the actuator mechanism).

The actuator base 362 is a generally rigid stationary member, which is the actuation system or actuator 361 firmly with the housing 302 of the transfer case 300 coupled. The actuator base 362 generally comprises a base section 362a (eg, a front or radially outer portion) adjacent the gear reduction mechanism 310, for example, with a thrust washer, a press fit, and / or other attachment means to the housing 302 of the transfer case 300 is coupled. The actuator base 362 further comprises a generally cylindrical body or body portion 362b (eg, a radially inner or annular portion or stem) extending from the base portion 362a off to the disc clutch 352 extends axially to the rear. The actuator base 362 includes a central bore (not marked) through which the primary output shaft 306 extends. Other components of the actuation system 361 are fixed or movable with the body section 362b coupled, as will be discussed below.

The motor 364 is configured through the reduction gears 366 the drive gear assembly 390 around the actuator base 362 which in turn causes the secondary torque-transmitting actuator mechanism 370 the disc clutch 352 actuates and causes the speed reduction actuator mechanism 380 the gear reduction hub 322 emotional. The motor 364 is with the case 302 firmly coupled, and the reduction gears 366 are with the case 302 at positions radially outside the primary output shaft 306 rotatably coupled.

The gear reduction actuator mechanism 380 Acts as a cylindrical or drum cam mechanism that holds the gear reduction hub 322 during the first stage (eg, initial rotation of the drive gear assembly 390 from a midpoint) between the first and second positions. The gear reduction actuator mechanism 380 includes a shift fork 382 and a drum 384 (eg switching cam). The drum 384 is configured to rotate the shift fork 382 in the transfer case 300 to move axially forward and backward to the gear reduction hub 322 between the first or forward position (ie, the gear reduction hub 322 the input shaft 304 directly with the primary output shaft 306 coupled; whereby the high range is established) and the second or reverse position (ie the gear reduction hub 322 the input shaft 304 and the primary output shaft 306 through the gear reduction mechanism 310 coupled; whereby the low range is produced) to move.

The shift fork 382 is a generally arcuate member substantially in the central bore of the body portion 362b the actuator base 362 and radially outside the primary output shaft 306 is positioned. The shift fork 382 is generally semicircular and includes an inner flange 382a extending from an inner peripheral surface of the shift fork 382 extends radially inward. The inner flange 382a is between radially outwardly extending peripheral flanges of the speed reduction hub 322 positioned and engaged with these, so that an axial movement of the shift fork 382 the gear reduction hub 322 moved axially between the first and second positions.

The shift fork 382 further comprises two rams configured as rollers 382b , each for engagement by the drum 384 (discussed below) from the outer peripheral surface of the shift fork 382 by an axially extending slot (not shown) in the body portion 362b the actuator base 362 extend radially outward. The axially extending slot of the body portion 362b the base holds the shift fork 382 in a constant rotational position with respect to the actuator base 362 while an axial translational movement of the shift fork 382 is allowed. The two pestles 382b are essentially one another opposite (ie offset approximately 180 degrees) or near ends of the shift fork 382 positioned. Every pestle 382b is with an axle extending from the ends of the shift fork 382 extends substantially radially outward (eg, perpendicular to the outer peripheral surface), and rotates about it. The shift fork 382 In addition, an approach or advantage for each pestle 382b which extends radially outward from the outer peripheral surface to which the axle is coupled.

The drum 384 is a generally cylindrical member that defines the body portion 362b of the actuator base 362 surrounds and is configured to revolve around thereby the shift fork 382 to move axially. The drum 384 includes an inner peripheral surface, which on an outer peripheral surface of the body portion 362b the actuator base 362 is applied. One or more pressure discs 367 and / or snap holder 368 are with the outer periphery of the body section 362b at an axial intermediate positioning thereof and adjacent to the base portion 362a coupled. While the drum 384 around the body section 362b The base rotates can edges of the drum 384 against the pressure discs 367 slip and abut against an axial force to move the gear reduction hub 322 with respect to the actuator base 362 to move forward and backward.

The drum 384 includes an inner cam slot 384a which is configured to the shift fork 382 engage and move axially and thus the speed reduction hub 322 to move between the first in the second position. Each cam slot 384a extends radially outward from the inner peripheral surface, with one of the plungers 382b the shift fork 382 in every slot 384a is positioned. Each cam slot 384a includes a range of motion with opposing ramped surfaces that define the plunger 382b during the first stage of movement (ie initial rotation of the drum 384 and the drive gear assembly 390 from the midpoint) to move the shift fork 382 axially forward and backward engage. The range of motion is through raised or flat areas in which the slot 384a the pestle 382b in the second stage of motion (eg, continued positive and negative rotation of respective ends of the first positive stage and the first negative stage) and in any subsequent movement in a generally fixed axial position.

For turning the drum 384 includes the drum 384 an outer radial flange or an outer radial member 384b that is radially outside of an outer circumferential surface of the drum 384 is positioned and away from a front end of the drum 384 extends axially to the rear. The outer radial member 384b is from a torsion spring 386 engaged, the torque from the drive gear assembly 390 for rotating the drum 384 transmits. In particular, the torsion spring 386 between the outer peripheral surface of the drum 384 and the outer radial member 384b positioned and around the outer peripheral surface of the drum 384 convoluted and is due to this. The torsion spring 386 includes two ends 386a for engaging axially extending edges of the outer radial member 384b and for engaging the drive gear assembly 390 extend radially outward for transmitting torque therebetween. In the case of a locked shift event (ie, when the splines of the reduction hub 322 Ends of splines of the input shaft 304 or planet carrier (not shown, see gear reduction mechanism 210 above) of the speed reduction mechanism 310 engage) allows the torsion spring 386 a relative rotational movement between the drum 384 and the drive gear assembly 390 and simultaneously stores energy that causes axial movement of the reduction hub 322 As soon as it properly engages the input shaft or gear reduction mechanism 310 is aligned.

The secondary torque-transmitting actuator mechanism 370 acts as a face cam mechanism (eg, a face cam mechanism, such as a ball ramp mechanism) for converting continuous rotation of the drive gear assembly 390 in an axial movement to operate the disc clutch 352 in the second stage of rotational movement (eg, continuous rotation of approximate ends of the first stage). The secondary torque-transmitting actuator mechanism 370 includes a front member 372 (eg, a first plate, a first ring, or a first cam member) and a rear member 374 (eg, a second plate, a second ring, or a second cam member) for relative rotation and resultant relative axial displacement to engage the disc clutch 352 are configured. Both the front limb 372 as well as the back limb 374 include middle openings or holes through which the primary output shaft 306 extends. The front limb 372 is with a rear end of the body section 362b the actuator base 362 coupled while the rear member 374 configured to both rotate and axially with respect to the front member 372 to move and thus the actuator base 362 to move. For example, the front member 372 as shown, in the middle hole extending through the body section 362b the actuator base 362 extends, positioned and can with this by a press fit, transition fit or Be coupled spline connection. The front limb 372 is positioned against a bearing member which is connected to the output shaft 306 coupled to prevent axial forward movement thereof. The back limb 374 is configured by the drive gear assembly 390 with respect to the front member 372 to be rotated, as will be discussed in more detail below, and is positioned to apply pressure to the actuator plate via an intermediate bearing 352c exercise. The intermediate bearing allows the actuator plate 352c independent of the posterior member 374 that moves back and forth within a limited range of motion of the second stage with the output shaft 306 rotates.

The front limb 372 and / or the rear member 374 include an inner surface (ie, facing the other plate, not shown) that includes two motion advancement regions that ramp up in opposite directions. Each or each of several plungers or rollers (eg balls) lies on the inner surfaces of both members 372 . 374 on, allowing a rotation of the rear member 374 from a center point, an axial backward movement of the rear member 374 for engaging the actuator plate 352c the disc clutch and thereby to the operation of the secondary torque transmitting mechanism 351 causes. As will be discussed below, the drive gear assembly is 390 configured to the plunger 374a during the first stage of movement (eg, initial rotation of the drive gear assembly 390 from the mid-point) to the secondary torque-transmitting actuator mechanism 370 not to operate. The front and the rear limbs 372 . 374 However, instead of or in addition to this, bump areas may be used for the first movement stage, in which rotation does not involve any axial movement of the rear member 374 causes, and / or any subsequent movement stage include.

For rotation of the rear member 374 with respect to the front member 372 is the back limb 374 configured to apply one or more tangential forces thereon to the drive gear assembly 390 (discussed in more detail below). The back limb 374 includes one or more rams configured as rollers 374a extending from a periphery of the posterior member 374 extend axially outwards. For example, the rear member 374 two pestles 374a which are substantially positioned opposite each other (ie, at a distance of approximately 180 degrees). Every pestle 374a is with an axis extending from the periphery of the posterior member 374 extends radially (eg, perpendicular to an outer surface thereof) and rotates about it. The back limb 374 In addition, an approach or projection for each plunger 374a which extends from the periphery of the rear member 374, with the axis and the plunger 374a are coupled, extends radially outward.

As mentioned previously, the drive gear assembly is 390 configured by the engine 364 over the reduction gears 366 for operating the secondary torque-transmitting actuator mechanism 370 and the speed reduction actuator mechanism 380 to be turned. The drive gear assembly 390 generally includes a detection plate 392 (eg a first plate), a hub 394 (eg, an actuator) and a gear plate 396 (eg, a second plate) for common rotation by the motor 364 are firmly coupled together. If the engine 364 the gear plate 396 over the reduction gears 366 drives, takes the hub 394 the plungers 374a for operating the secondary torque-transmitting actuator mechanism 370 engaged and the detection plate 392 takes the torsion spring 386 for operating the speed reduction actuator mechanism 380 engaged. The drive gear assembly 390 is about the actuator base 362 positioned around, wherein an inner circumferential surface of the hub 394 on the outer peripheral surface of the body portion 362b the actuator base 362 is applied. The drive gear assembly 390 is between one of the pressure discs 367 and one with the body portion 362b the actuator base 362 coupled end plate held axially on the actuator base 362. Although the drive gear arrangement 390 Alternatively, it may be provided as a single component or two primary components, an arrangement of the detection plate 392 , the hub 394 and the gear plate 396 provide a less complicated manufacturing while allowing for individual configuration of each component (eg, to optimize the material type according to strength, weight and cost considerations).

The gear plate 396 is to receive an input torque from the motor 364 via the reduction gears 366 configured by a first movement stage, a second movement stage, and any subsequent movement stages of the drive gear assembly 390. The gear plate 396 is a one-piece, generally planar member having a central bore or opening through an inner periphery 396a and an outer periphery 396b is defined. The primary output shaft 306 extends along with other components of the actuator 361 through the middle opening. The outer periphery 396b includes a plurality of teeth that mate with mating teeth of the reduction gears 366 for rotation by the engine 364 comb. Because the actuator 361 in the first and second stages of movement in a limited range of rotational movement (eg +/- 60 degrees) as described above for the operation of both the secondary Drehmomentübertragungsaktuatormechanismus 370 as well as the gear reduction actuator mechanism 380 is operated, only a portion of the outer periphery 396b (eg, 180 degrees) teeth. The gear plate 396 For example, it may be made of powder metallurgical steel and, as will be discussed in more detail below, may have various features to enable coupling with the sensing plate 392 and / or the hub 394 include.

The detection plate 392 is configured to from the gear plate 396 for operating the speed reduction actuator mechanism 380 to be driven. The detection plate 392 can also use a position sensor 369 for monitoring the rotational position of the actuator 361 be configured. The detection plate 392 is a one-piece link, generally a planar section 392a with one through an inner periphery 392b defined central bore or opening and further comprises a first and a second annular flange 392c . 392d includes, extending from an outer periphery of the planar section 392a extend axially forward. In the drive gear assembly 390 is the planar section 392a in front of and beside a front surface of the gear plate 396 positioned. The first flange 392c extends substantially circumferentially (eg, about 270 degrees) and the outer periphery of the planar portion 392a , The second flange 392d is with respect to the outer radial member 384b the drum 384 configured via the torsion spring 386 To transmit torque in between. In particular, the second flange 392d is between the circumferential ends of the first flange 392c positioned and has a width that corresponds to the width of the outer radial member 384b the drum 384 is complementary, so that both the outer radial member 384b the drum 384 as well as the second flange 392d the detection plate 392 between the ends 386a the torsion spring 386 are positioned and engaged with these. The second flange 392d is also radially between the winding of the torsion spring 386 and the outer radial member 384b the drum 384 positioned. The detection plate 392 For example, it may be made from stamped steel and, as discussed in greater detail below, may have various features to facilitate coupling to the hub 394 and / or the gear plate 396 include.

The hub 394 is configured through the gear plate 396 for operating the secondary torque-transmitting actuator mechanism 370 for example, in limited ranges of movement of the drive gear arrangement 390 to be driven. During the first stage of movement (eg, initial rotation from the midpoint, with the secondary torque-transmitting actuator mechanism 370 the gear reduction hub 322 moved, as previously discussed), the hub rotates 394 free from the secondary torque-transmitting actuator mechanism 370 to the disc clutch 352 not indulge. During further rotation in the second stage of motion (eg, continued positive and negative rotation of respective first stage ends), the hub decreases 394 the secondary Drehmomentübertragungsaktuatormechanismus 370 engaged. The hub 394 turns, for example, one with the rear member 374 common axis (eg the axis of the primary output shaft 306 ).

The hub 394 is an integral member, generally a base portion 394a (eg, a radial flange) having a central opening and an annular body 394b which extends from an inner periphery of the base section 394a extends axially and around the body portion 362b the actuator base 362 turns and rests against it. As a part of the drive gear assembly 390 The annular body 394b extends through the central openings of the detection plate 392 and the gear plate 396 to the rear, with the detection plate 392 between the base section 394a the hub 394 and the gear plate 396 is held. The hub 394 For example, it may be made of powder metallurgical steel and, as will be discussed in more detail below, may have various features to enable coupling with the sensing plate 392 and / or the gear plate 396 include.

The detection plate 392 , the hub 394 and the gear plate 396 are rigidly coupled to each other, the drive gear assembly 390 to form and to turn together as a single entity. According to the in 3 - 5 the embodiment shown are the detection plate 392 , the hub 394 and the gear plate 396 coupled together by a press-fitted, splined arrangement. In particular, the annular body 394b (eg, the inner peripheral flange) of the hub 394 for insertion into the central hole of the detection plate 392 and the middle hole of the gear plate 396 configured. The diameter of the outer surface of the annular body 394b the hub 394 nominally has an outer diameter slightly smaller than the inner diameter of the inner peripheries 392b and 396a the detection plate 392 or the gear plate 396 is. The annular body 394b includes multiple coupling splines 394j extending axially and projecting radially outwardly from the outer surface in one or more regions about the inner peripheries 392b and 396a the detection plate 392 and the gear plate 396 firmly engage and couple. For example, the coupling splines 394j may be configured to the inner peripheries 392b and 396a shaping material to deform or cut while the detection plate 392 and the gear plate 396 successively on the annular body 394b the hub 394 be pressed. The annular body 394b may also have one or more alignment splines 394K which extend axially and project radially outward from the outer surface at one or more locations to engage in the alignment slots 392 f and 396c the detection plate 392 or the gear plate 396 to be included. During operation, the engine decreases 364 over the reduction gears 366 the gear plate 396 engages and rotates, thereby providing torque to the hub via the spline connection 394 is transmitted, which in turn via the spline connection torque on the detection plate 392 is transmitted.

The hub 394 also defines slots 394c or cut-outs (eg, two slots) in the annular body 394b in which the pestles 374a the secondary Drehmomentübertragungsaktuatormechanismus 370 are positioned (see eg 6 ). Every slot 394c is between two end walls 394d or webs (eg, circumferentially opposed end walls) of the annular body 394b defined, which extend axially to the rear. The slots 394c are uniformly dimensioned and are according to a spacing of the plunger 374a circumferentially spaced to allow simultaneous engagement of the plungers 374a during a rotation of the drive gear assembly 390 provide. During the first stage of movement remain the ram 374a each in a central region of the slot 394c between the opposite end walls 394d , With further rotation in the second movement stage takes each of the two end walls 394d , one from each slot 394c , at the same time one of the plungers 374a engages and applies a tangential force thereto, around the rear member 374 the secondary Drehmomentübertragungsaktuatormechanismus 370 to turn. This rotation shifts the rear member 374 axially from the front member 372 to the rear (ie to the disc clutch 352 squeeze) while the pestles 374a along the opposite end walls 394d roll backwards. The end walls 394d have an axial length that allows the plungers 374a through the entire axial displacement area of the secondary torque-transmitting actuator mechanism 370 move on.

A force is applied to the end walls 394d through the pestles 374a A localized contact pressure (eg Hertzian pressure) is created on a flat surface of the end wall 394d at the interface with the curved surface of the plunger 374a , Depending on the peak output of the actuator 361 (eg by the reduction gears 366 and the gear plate 396 through the engine 364 applied torque) and the material properties of the hub 394 This localized tip contact pressure can cause plastic deformation or fatigue of the hub 394 in the area of the end walls 394d for example, during conditions causing blocked circuitry. According to an exemplary embodiment, the entire hub is 394 made of a single material (eg, powder metallurgical steel) having sufficient strength to prevent plastic deformation by expected localized peak contact pressure of the end walls 394d and to prevent fatigue by repeated loading of the end walls 394d provides. For example, the yield strength can be greater than about 1.5-2.0 times the expected peak contact pressure.

According to another exemplary embodiment, the hub 394 treated (eg by anodizing, case hardening, etc.) to the material of the hub 394 including the end walls 394d , to provide sufficient strength to prevent plastic deformation by expected localized tip contact pressure of the end walls 394d and to prevent fatigue by repeated loading of the end walls 394d provide. For example, the yield strength after treatment or cure may be greater than about 1.5-2.0 times the expected peak contact pressure.

In accordance with further exemplary embodiments, which will be discussed in more detail below, the hub includes 394 a bearing member ( 498 . 598 etc.) coupled to one or more of the end walls (eg, 494d, 594d, etc.). Each bearing member ( 498 . 598 etc.) has greater resistance to deformation, generally in correlation with hardness and tensile strength, to prevent deformation by the expected tip contact pressure generated by the plunger 374a it is sufficient. The bearing member acts to force the localized contact pressure through the plunger 374a substantially over the end wall 394d to distribute away. The bearing member can thereby a localized shape change of the end wall 394d the hub 394 prevent deformation caused by fatigue caused by cyclic loading. Advantageously, the use of a bearing member allows the remainder of the hub (eg, 498, 598, etc.) to be made from lesser amounts of material or less solid materials (eg, having a lower hardness), thereby over the hub 394 Weight and cost advantages can be provided. For example, the bearing member may be made of a stamped steel or powder metallurgical steel, which may be treated or untreated, while the hub is made of another Material with a lower resistance to deformation and / or a lower density (eg powdered light metal, such as aluminum, magnesium and alloys thereof, composite or polymer) is made. Each bearing member may also have a larger surface area than the end wall 394d with which it is coupled, provide (eg, be wider), and act to provide localized contact pressure by the plunger 374a largely over the end wall 394d to distribute away.

In either embodiment, the bearing member is cooperatively configured with the end wall (eg, 494d) to provide a lift area that is parallel to the axis of the primary output shaft 306 is substantially parallel (ie, axial direction) and sufficient circumferential stroke in the slot (eg, 494c) for proper operation of the secondary torque-transmitting actuator mechanism 370 provide. For each following embodiment, reference numbers will be referenced to portions of the hub 394 or other primary components of the actuation system 361 (eg the gear plate 396 and the limb 374 the actuating mechanism 370 ), while the discussion and figures for readability may only refer to a subset of such numerals. It should also be noted that the bearing member (eg, 498) may vary depending on the configuration of the secondary torque-transmitting actuator mechanism 370 , the secondary torque transmitting mechanism 351 and the actuator 361 494d) of each slot (eg, 494c), for example, if in the second range of motion of the gear plate assembly (eg, 490), either no positive or negative rotation, the secondary torque transmitting mechanism 351 operates (eg at a feed of the second link 374 for compressing the disc clutch 352 in only one direction, either positive or negative).

According to a first embodiment of the bearing member 498 that the 7 is shown, the bearing member 498 a general L-shaped cross-section with a bearing segment 498a or bearing portion extending radially outward to a coupling segment or coupling portion 400 8b extends, which extends in a circumferential direction. The storage segment 498a forms a bearing surface, which is one end of the slot 494C for contact with the plunger 374a and a back surface facing the end wall 494d the hub 494 is positioned, the local contact force of the plunger 374a of the posterior member 374 along the end wall 494d to distribute forms. The coupling segment 498b forms a flange which is on a radially outer surface 494e of the annular body 494b the hub 494 is positioned and configured to the bearing member 498 over conventional fasteners 498c , such as B. threaded fasteners, rivets and / or adhesive to couple with it. The coupling segment 498b may be at least partially in an outer groove of the hub 494 near the end wall 494d (as shown), completely in an outer groove of the hub 494 (eg, making it with the radially outer surface 494e of the annular body 494b the hub 494 flush or recessed with respect to it) may be positioned or may be completely off the radially outer surface 494e protrude.

According to a second embodiment of the bearing member 598 , in the 8th is shown, has a bearing member 598 a generally T-shaped cross-section with a bearing segment 598a having a bearing surface which is one end of the slot 494C defined for contact with the plunger 374a and a rear surface facing the end wall 594d the hub 594 is positioned, the local contact force of the plunger 374a along the end wall 594d to distribute forms. The bearing member 598 further comprises a central position of the rear surface of the bearing segment 598a , circumferentially (ie with respect to the slot 594c outward) extending coupling segment 598b , the barb 598c may include, extending from or near one end thereof in an inwardly extending and an outwardly extending radial direction. The coupling segment 598b is in an axially extending slot 594p (eg, complementary slot) (ie, the outlines of the coupling segment 598b and the barb 598c having; in 8A shown in phantom) in the end wall 594d the hub 594 between the radially outer surface 594e and a radially inner surface 594g of the annular body 594b added. The axially extending slot in the end wall 594d has one to that of the coupling segment 598b the bearing member 598 complementary cross-sectional profile (ie for receiving the coupling segment 598b and his barbs 598c ), which is both a circumferential and a radial movement of the bearing member 598 concerning the hub 594 prevented. An axial movement of the bearing member 598 concerning the hub 394 can by a press fit therebetween (ie, the coupling segment 598b is in the slot 594p received) and / or a holding member 598d or a retaining flange that is on an axially facing surface 594f the 594b flange of the hub 394 positioned and secured thereto (eg, with conventional fasteners and / or adhesives). The holding member 598d can be part of the bearing element 598 be or be positioned on an axially facing surface thereof.

According to another exemplary embodiment, which is described in 9 is shown is a bearing member 698 essentially similar to the bearing member 598 configured and includes a generally T-shaped cross-section with a bearing segment 698a and a coupling segment 698b (shown in FIG 9 shown in phantom) for inclusion in a complementary axially extending slot 694p in the annular body 694b the hub 694 , To prevent axial movement of the bearing member 698 concerning the hub 694 is a snap 698e (made, for example, of a missing metal, such as steel) in a circumferential groove formed in the radially outer surface 694e (ie the snap member 698e in the presentation and gives) of the annular body 694b the hub 694 machined or otherwise formed, taken or snapped into it. The snap member 698e extends radially inwardly beyond the end wall 694D and, for example, may have a spring-loaded end (not shown) that bears against the radially inner surface 694g of the annular body 694b the hub 694 suppressed. The snap link 698e is to prevent axial movement of the bearing member 698 with an axially facing surface or an axially facing end of the bearing member 698 engaged. The snap link 698e may further circumferentially to the second slot 694c the hub 694 extend to equally a bearing member on the end wall 694D to keep it from. The axial length of the annular body 600 4b may require an expansion in comparison to other bodies to provide sufficient space for the annular groove for receiving the snap member 698e while providing sufficient stroke for the rollers 374a along the storage segment 698a of the bearing member 698 provide.

According to yet another exemplary embodiment, which is disclosed in U.S. Pat 10A and 10B is shown, has a bearing member 798 a generally U-shaped configuration and is over the end wall 794b the hub 794 added. The bearing member 798 includes a bearing segment 798a and coupling segments 798B . 798c that form legs that extend circumferentially from the base section 798a extend away and the end wall 794b the hub 794 surround. The storage segment 798a includes a bearing surface, which is one end of the slot 794c for contact with the plunger 374a and a rear surface of the bearing segment 798a that to the end wall 794d the hub is positioned, the local contact force of the plunger 374a along the end wall 794d to distribute, defined. The coupling segments 798B . 798c can the annular body 794b next to the end wall 794d the hub 794 squeeze in between. The bearing member 798 may instead or in addition include tabs or prongs 798d that engage the outer and inner radial surfaces 794e , 794d of the annular body 794b the hub 794 to a movement of the bearing member 798 with respect to the annular body 300 4b prevent from the coupling segments 798B , 798c. The bearing member 798 may further include one or more tabs or prongs 798e that engage the end wall 794b the hub 794 to a movement of the bearing member 798 with respect to the annular body 794b prevent from the bearing segment 798a extend. For example, the noses 798d . 798e in the end wall 794b of the hub 794 forming material are pressed to the bearing member 798 To keep it (ie to prevent turning back).

Although the disclosure has been made in conjunction with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the disclosure is intended to cover various modifications and equivalent arrangements.

Claims (12)

A transfer case comprising: a primary output shaft (306); a secondary output shaft (308) selectively connectable to a secondary torque transmitting mechanism (351) for transmitting torque from the primary output shaft (306) to the secondary output shaft (308) with the primary output shaft (306); and an actuator comprising: a hub member (394; 494; 594; 694; 794) comprising an annular body (394b; 494b; 594b; 694b; 794b) having a circumferential slot (394c; 494c; 594c; 694c 794c); a bearing member (498; 598; 698; 798) coupled to said annular body (394b; 494b; 594b; 694b; 794b) and positioned in said slot (394c; 494c; 594c; 694c; 794c), wherein the bearing member (498; 598; 698; 798) includes a bearing surface extending in an axial direction with respect to the annular body (394b; 494b; 594b; 694b; 794b); and an end cam mechanism (370) which, when rotated by the hub member (394; 494; 594; 694; 794), translates to drive the secondary torque transmitting mechanism (351) in the axial direction, the end cam mechanism (370) displacing a plunger (374a). which is engaged by the bearing member (498; 598; 698; 798) and moves axially along the bearing surface when the face cam is rotated by the hub member (394; 494; 594; 694; 794); wherein the annular body (394b; 494b; 594b; 694b; 794b) comprises an end wall (394d; 494d; 594d; 694d; 794d) at a circumferential end of the circumferential slot, the bearing member (498; 598; 698; 798) is formed of a material 794d), and the bearing member receives a localized force from the plunger 374a over the end wall 394d, 494d, 594d, 694d ; 794d) distributed; and wherein the bearing member (498; 598; 698; 798) comprises a bearing segment (498a; 598a; 698a; 798a) forming the bearing surface and a coupling segment (498b; 598b; 698b; 798b, 798c) connected to the annular body (394b; 494b; 594b; 694b; 794b). Transfer case to Claim 1 wherein the bearing segment (498a; 598a; 698a; 798a) includes a rear surface opposite the bearing surface, the rear surface being engaged with the end wall (394d; 494d; 594d; 694d; 794d) for distributing a force thereacross. Transfer case according to one of Claims 1 - 2 wherein the bearing member (498; 598; 698; 798) has a cross-sectional profile extending in the axial direction. Transfer case according to one of Claims 1 - 3 wherein the bearing member (498; 598; 698; 798) is received by at least one attachment means (498c; 798d) or the coupling segment (598b; 698b) received in a complementary slot (594p; 694p) of the annular body (594b; 694b) is coupled to the annular body (594b; 694b). A transfer case according to any one of the preceding claims, wherein the hub member (394; 494; 594; 694; 794) is configured to move independently of the face cam mechanism (370) in a first range of travel in which the bearing member (498; 598; 698; 798 ) is not engaged with the plunger (374a), and in a second range of motion in which the bearing member (498; 598; 698; 798) is engaged with the plunger (374a) to rotate the face cam mechanism (370) , Transfer case to Claim 5 wherein the secondary torque transmitting mechanism (351) comprises a disc clutch (352) wherein the face cam mechanism (370) axially translates to the second range of motion; the disc clutch (352) selectively couples the primary output shaft (306) to the secondary output shaft (308 ) to compress. Transfer case to Claim 6 wherein the secondary torque transmitting mechanism (351) includes a first sprocket (350) coupled to a housing (352a) of the disc clutch (352) to be selectively coupled to the primary output shaft (306), a second sprocket (354), which is coupled to the secondary output shaft (308), and a chain (356) coupling the first sprocket to the second sprocket for transmitting torque therebetween. Transfer case according to one of Claims 5 - 7 further comprising an input shaft (304) and a speed reduction mechanism (310) configured to selectively couple the input shaft (304) between a first drive ratio and a second drive ratio to the primary output shaft (306), the actuator thereto is configured to operate the speed reduction mechanism (310) in the first range of motion to selectively couple the input shaft (304) in the first drive ratio or the second drive ratio to the primary output shaft (306) and the secondary torque transmitting mechanism (351) in the second Operate range of motion. A transfer case according to any one of the preceding claims, wherein the plunger (374a) is a roller configured to roll along the bearing surface. A transfer case according to any one of the preceding claims, wherein the hub member (394; 494; 594; 694; 794) comprises two slots (394c; 494c; 594c; 694c; 794c), each slot (394c; 494c; 594c; 694c; 794c) is defined by two end walls and one of the bearing members (498; 598; 698; 798) thereof is coupled to each end wall (394d; 494d; 594d; 694d; 794d); and wherein the face cam mechanism (370) comprises two plungers (374a) which are rollers, each plunger (374a) being positioned in one of the two slots (394c; 494c; 594c; 694c; 794c) and configured to along the bearing surface each bearing member (498; 598; 698; 798) of the slot (394c; 494c; 594c; 694c; 794c) in which the plunger (374a) is positioned to roll. A transfer case according to any one of the preceding claims, wherein the face cam mechanism (370) comprises a first cam member (372) and a second cam member (374), the first cam member (372) being axially fixed with respect to the hub, the follower (374a) with the second Cam member (374) is coupled and the second cam member (374) through the hub with respect to the first cam member (372) for axial displacement with respect to the first cam member (372) is rotatable. An actuator for a transfer case, comprising: an actuator member (394; 494; 594; 694; 794) comprising a peripheral slot (394c; 494c; 594c; 694c; 794c) disposed between two end walls (394d; 494d; 594d; 694d; 794d) formed by an annular body (394b; 494b; 594b; 694b; 794b), at least one of the end walls (394d; 494d; 594d; 694d; 794d) having a bearing member (498; 598 ; 698; 798) and forms a bearing surface extending in an axial Direction with respect to the annular body (394b; 494b; 594b; 694b; 794b); an end cam mechanism (370) comprising a first cam member (372), a second cam member (374) and a plunger (374a) coupled to the second cam member (374), the second cam member (374) configured thereto to axially displace relative to the first cam member (372) upon rotation with respect to the first cam member (372), the plunger (374a) being disposed in the slot (394c; 494c; 594c; 694c; 794c); and a motor (364) configured to maintain the annular body (394b; 494b; 594b; 694b; 794b) in a first range of motion independently of the face cam mechanism (370) and in a second range of motion in which the bearing member (498; 598; 698; 798) is in engagement with the plunger (374a) to rotate the second cam member (374) relative to the first cam member (372) and in which the plunger (374a) extends axially along the bearing surface of the bearing member (498) ; 598; 698; 798) moves to rotate; wherein the bearing surface is formed of a material which is harder than another material forming the end wall (394d; 494d; 594d; 694d; 794d) to which the bearing member (498; 598; 698; 798) is coupled ; and wherein the bearing member (498; 598; 698; 798) comprises a bearing segment (498a; 598a; 698a; 798a) and a coupling segment (498b; 598b; 698b; 798b, 798c), the coupling segment (498b; 598b; 698b; 798b, 798c) is coupled to the annular body (394b; 494b; 594b; 694b; 794b) and the bearing segment (498a; 598a; 698a; 798a) forming the bearing surface and a rear surface is connected to the end wall (394d; 494d; 594d; 694d; 794d).

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