WO2009035678A1

WO2009035678A1 - Transfer case employing an itm coupling at the output shaft of the transfer case

Info

Publication number: WO2009035678A1
Application number: PCT/US2008/010683
Authority: WO
Inventors: Larry A. Pritchard; Hans R. Beels Van Heemstede; Christopher J. Kowalsky
Original assignee: BorgWarner Inc
Current assignee: BorgWarner Inc
Priority date: 2007-09-12
Filing date: 2008-09-12
Publication date: 2009-03-19
Anticipated expiration: 2010-03-12

Abstract

The present invention is a transfer case having a primary output member, and a secondary output member driven for rotation by the primary output member. The transfer case of the present invention also includes an output element operable for receiving rotational force from the secondary output member through the use of a clutch assembly, and a pump for providing lubrication to the clutch assembly, the primary output member, and the secondary output member.

Description

TRANSFER CASE EMPLOYING AN ITM COUPLING AT THE OUTPUT SHAFT OF THE TRANSFER CASE

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a PCT International Application of United States

Provisional Patent Application No. 60/993,353 filed on September 12, 2007. The disclosure of the above application is incorporated herein by reference.

FIELD OF THE INVENTION The present invention relates to transfer cases, and the use of a clutch assembly mounted on a secondary output shaft, as well as a dry sump for providing lubrication to the clutch assembly as well as the sprockets and chain.

BACKGROUND OF THE INVENTION

Transfer cases for motor vehicles are generally known. Transfer cases will typically have two output shafts, one of which is a primary output shaft for continuously receiving rotational power from the transmission and delivering the rotational power to a set of primary drive wheels. The transfer case also includes a secondary output shaft, which can be selectively engaged to deliver rotational power from the transmission to a secondary set of wheels. The transfer case is typically activated to deliver power to the secondary set of wheels when certain driving conditions occur, such as vehicle dynamic events where the transfer of torque to a secondary axle would enhance vehicle stability or improve vehicle handling response. An example of this would be wheel slip when the vehicle is driving on snow and ice. Rotational power is typically transferred from the primary output shaft to the secondary output shaft through the use of a clutch assembly. The clutch assembly is often mounted inside the transfer case and circumscribes the primary output shaft. The primary output shaft also typically has a sprocket which is partially circumscribed by a chain which transfers rotational power to another sprocket which is mounted about the secondary output shaft. Upon engagement of the clutch assembly, the sprocket mounted about the primary output shaft will transfer rotational force through the chain to the secondary sprocket mounted about the secondary output shaft. The clutch assembly can be selectively engaged, depending on the desired operating conditions of the transfer case.

Transfer cases also require lubrication, both for the clutch assembly as well as the other rotating parts, such as the primary and secondary output shafts. This lubrication is commonly provided through what is known as "splash lube," where one or both of the sprockets are partially submerged in a bath of oil, whereupon rotation of one or both of the sprockets, lubrication will be splashed throughout the transfer case, providing lubrication to the clutch assembly and other rotating parts.

However, due to various packaging restraints, it is not always advantageous to have the clutch assembly mounted upon the primary output shaft. Also, it is not always advantageous to use splash lubrication to provide lubrication for the transfer case. Using splash lubrication increases the drag of the chain and sprockets, as well as reduces the overall efficiency of the transfer case, which can reduce the efficiency of the vehicle, affecting various things such as fuel economy.

Accordingly, there exists a need for an improved transfer case which has the clutch assembly mounted in a location other than around the primary output shaft, and also the need for an improved type of lubrication which can improve the efficiency of the transfer case.

SUMMARY OF THE INVENTION

The present invention is a transfer case having a primary output member and a secondary output member driven for rotation by the primary output member. The transfer case of the present invention also includes an output element operable for receiving rotational force from the secondary output member through the use of a clutch assembly, and a pump for providing lubrication to the clutch assembly, the primary output member, the secondary output member, and the output element.

When the clutch assembly is disengaged, the output element will not receive rotational force from the secondary output member, and when the clutch assembly is engaged, the secondary output member will transfer rotational force to the output element. As the secondary output element rotates, the pump will deliver lubrication to the clutch assembly, the primary output member, the secondary output member, and the output element.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a sectional view of a transfer case, according to the present invention;

Figure 2 is an enlarged sectional view of a portion of a transfer case, according to the present invention; and

Figure 3 is a second enlarged sectional view of a portion of a transfer case, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Referring to the Figures generally, a transfer case according to the present invention is shown generally at 10. The transfer case 10 has a housing 12, which has a first half 14 connected to a second half 16 through the use of fasteners 18, such as bolts 18 received in threaded apertures 20. The first half 14 of the housing 12 also has apertures 22 which are used for receiving fasteners (not shown) for connecting the transfer case 10 of the present invention to the transmission (not shown) of an automobile. Extending through the housing 12 of the transfer case 10 is a primary output member, which in this embodiment is a primary output shaft 24, which is suited for connection to the output shaft of the transmission. The primary output shaft 24 has a shoulder 26 for receiving the inner race 28 of a roller bearing 30. The first half 14 of the housing 12 also has a shoulder 32 for receiving the outer race 34 of the roller bearing 30. The inner race 28 of the roller bearing 30 is also adjacent to a primary sprocket 36. The primary sprocket 36 is also adjacent to the inner race 38 of a large bearing 40. The inner race 38 of the large bearing 40 is also received in a shoulder 42 of the primary output shaft 24. The large bearing 40 also has an outer race 44 which is positioned between a shoulder 46 in the second half 16 of the housing 12, and a snap ring 48 which is located in a groove 49.

The primary sprocket 36 is also connected to the primary output shaft 24 through a spline connection 50. The primary sprocket 36 also includes teeth 52 which are partially circumscribed by a chain 54. Also connected to the primary output shaft 24 is a flange 56. The flange 56 rests against the inner race 38 of the large bearing 40, and rotates with the primary output shaft 24 through a spline connection 58. The primary output shaft 24 also has threads 60 which receive a threaded nut 62. The threaded nut 62 is tightened onto the threads 60 to apply a force to a washer 64, the washer 64 then applies a force to a shoulder 66 on the flange 56, locating the flange 56 between the inner race 38 of the bearing 40, and the washer 64. The flange 56 is used for connecting the primary output shaft 24 to a drive shaft (not shown) for connecting the transfer case 10 to a primary set of wheels (not shown). The housing 12 also includes a pair of seals 68 for the prevention of fluid leakage out of the housing 12. The chain 54 also partially circumscribes and is in mesh with teeth 70 on a secondary sprocket 72. The secondary sprocket 72 also includes shoulders 74 which locate the secondary sprocket 72 between an inner race 76 of each of a pair of bearings 78. Each of the bearings 78 also include an outer race 80. One of the outer races 80 is adjacent a shoulder 82 in the first half 14 of the housing 12, and the outer race 80 of the other bearing 78 is adjacent a shoulder 84 in the second half 16 of the housing 12. The bearings 78 allow the secondary sprocket 72 to rotate relative to the housing 12. The secondary sprocket 72 rotates with, and applies rotational force to, a secondary output member, which in this embodiment is a secondary output shaft 86 through the use of a spline connection 88. The secondary output shaft 86 extends from the housing 12 into a clutch housing 90, and includes a shoulder 92 for locating the secondary sprocket 72. The clutch housing 90 is part of a clutch assembly, generally shown at

94, for selectively engaging the secondary output shaft 86 to transfer rotational force through the clutch assembly 94. While the clutch assembly 94 described below is used with the present invention, it is also within the scope of the invention that other types of clutch assemblies having different actuation may be used. For purposes of illustration but not limitation, other types of clutch assemblies which are used include a pulse-torque-modulated (PTM) clutch assembly and actuator, or a clutch actuation assembly with an electromagnetic coil having a housing with oblique surfaces, such as the clutch assembly shown in U.S. Patent No. 6,905,008, the entire specification of which is incorporated herein by reference.

The secondary output shaft 86 is selectively engagable with an output element 96 through the use of a clutch pack, generally shown at 98. The clutch pack 98 includes a first series of clutch plates 100 which are interleaved with a second series of clutch plates 102. The first series of clutch plates 100 rotate with the output element 96 through the use of a spline connection 104. The second series of clutch plates 102 rotate with the secondary output shaft 86 through the use of a spline connection 106. The clutch pack 98 is positioned between an apply plate 108 which rotates with the secondary output shaft 86 through the use of a spline connection 110, and a collar 112, which rotates with the output element 96, and is held in place with a washer 114 and a snap ring 116 located in a groove 118. The collar 112 is allowed to rotate relative to the primary output shaft 86 because of a bearing 120. There is another bearing 122 which allows relative rotation between the output element 96 and the secondary output shaft 86. The apply plate 108 has a series of recesses 124 which receive a portion of a series of corresponding load transferring members, which in this embodiment are a series of load transferring balls 126. Another portion of the load transferring balls 126 are received in corresponding recesses 128 in a cam plate 130. Both sets of recesses 124,128 have a deeper portion which transitions to a shallower portion. The cam plate 130 rotates with a third series of clutch plates 132 because of a spline connection 134. The third series of clutch plates 132 are part of a secondary clutch pack, generally shown at 136. The secondary clutch pack 136 also includes a fourth series of clutch plates 138 which are interleaved with the third series of clutch plates 132. The fourth series of clutch plates 138 rotate with the output element 96 because of a spline connection 140.

Extending through the secondary clutch pack 136 are a plurality of extensions 142 which are connected to a second apply plate 144. The extensions 142 are able to slide through a corresponding plurality of apertures 146 in the output element 96. The extensions 142 are able to slide through the apertures 146 because of an electromagnetic assembly, generally shown at 148. The electromagnetic assembly 148 has a housing 150 which surrounds an electromagnetic coil 152. The housing 150 is connected to a support member 154 and the clutch housing 90 through the use of a fastener 156, such as a nut and bolt. The electromagnetic coil 152 can receive a current through a coil wire 158, the function of which will be described later.

The output element 96 is able to rotate relative to the clutch housing 90 through the use of a bearing 160. The bearing 160 has an inner race 162 which rests between a shoulder 164 on the output element 96, and a flange 166. The bearing 160 also has an outer race 168 which rests against a shoulder 170 of the clutch housing 90. The flange 166 rotates with the output element 96 because of a spline connection 172. The output element 96 also includes a series of threads 174 which receive a threaded nut 176. The threaded nut 176 is tightened onto the threads 174 to apply a force to a washer 178; the washer 178 then applies a force to a shoulder 180 on the flange 166, locating the flange 166 between the inner race 162 of the bearing 160, and the washer 178. The flange 166 is used for connecting the output element 96 to a drive shaft (not shown) for connecting the transfer case 10 to a secondary set of wheels (not shown). A seal 182 is located between the flange 166 and the clutch housing 90 to prevent fluid leakage and dust from entering the clutch housing 90. The transfer case 10 also has a lubrication system. The lubrication system of the present invention is a dry sump lubrication system. There is a dry sump 184 which is located in the second half 16 of the housing 12. The dry sump 184 ensures that the chain 54 to does not contact the fluid in the dry sump 184. There is a first fluid passage 186 which places the dry sump 184 in fluid communication with a pump 188, which in this embodiment is a gerotor pump. The gerotor pump 188 is driven by the secondary output shaft 86. During assembly, the gerotor pump 188 is placed onto the secondary output shaft 86, and is held in place by a pump cover 190 which is connected to the housing through a set of screws 192.

The gerotor pump 188 is capable of delivering fluid through a bore 194 in the secondary output shaft 86. The bore 194 is in fluid communication with a series of oil feed holes 196, which facilitate the delivery of fluid to the clutch pack 98. The gerotor pump 188 also delivers fluid to a second fluid passage 198, the second fluid passage is in fluid communication with a third fluid passage 200. There is a drain passage 202 formed in the first half 14 of the housing 12, which receives fluid that drains from the clutch pack 98 into the clutch housing 90.

In operation, the primary output shaft 24 receives rotational power from the transmission, thereby causing the primary sprocket 36 and the flange 56 to rotate as well. The flange 56 will transfer power to a driveshaft, which is then used to rotate a set of wheels. Additionally, the teeth 52 on the primary sprocket 36 will cause the chain 54 to transfer the rotational power to the secondary sprocket 72. Therefore, the primary output shaft 24, primary sprocket 36, secondary sprocket 72, and secondary output shaft 86 will always rotate at substantially the same speed.

When it is desired to transfer rotational power from the secondary output shaft 86 to the output element 96, a current is sent through the coil wire 158 to the electromagnetic coil 152. An electromagnetic field is generated, which draws the second apply plate 144, along with the extensions 142, toward the electromagnetic coil 152, applying pressure and compressing the secondary clutch pack 136. Compressing the secondary clutch pack 136 will cause relative rotation between the cam plate 130 and the apply plate 108. This relative rotation will cause the load transferring balls 126 to roll in the recesses 124 of the apply plate 108, and the recesses 128 of the cam plate 130. The load transferring balls 126 will roll from the deeper portion to the shallower portion. This will cause the apply plate 108 to translate along the secondary output shaft 86, compressing the clutch pack 98. Rotational force will then be transferred from the secondary output shaft 86, through the spline connection 106 to the second series of clutch plates 102, to the first series of clutch plates 100, through the spline connection 104, and to the output element 96. The amount of rotational force transferred is variable, and is dependent upon the amount of current applied to the electromagnetic coil 152. If enough current is applied to the electromagnetic coil 152 to compress the secondary clutch pack 136, and generate enough relative rotation between the cam plate 120 and the apply plate 108 such that the load transferring balls 126 will roll in the recesses 124 of the apply plate 108 and the recesses 128 of the cam plate 130 to cause the apply plate 108 to translate along the secondary output shaft 86 enough to fully compress the clutch pack 98, all of the rotational power in the secondary output shaft 86 is transferred to the output element 96, and the secondary output shaft 86 and the output element 96 will rotate at the same speed. When current is applied to the electromagnetic coil 152 such that the clutch pack 98 is not fully compressed, the clutch assembly 94 acts as a slipping clutch.

As the secondary output shaft 86 rotates, the gerotor pump 188 draws fluid from the dry sump 194 through the first fluid passage 186. The fluid is then delivered through either the bore 194 in the secondary output shaft 86, or the second fluid passage 198. The fluid which flows through the bore 194 flows through the oil feed holes 196 and through the clutch pack 98, providing lubrication for the clutch pack 98. After the fluid flows through the clutch pack 98, the fluid will then flow toward the bottom of the clutch housing 90, and then through drain passage 202, where the fluid will return to the dry sump 194.

Fluid that flows through the second fluid passage 198 then flows through the third fluid passage 200. The fluid that flows through the third fluid passage 200 will drip onto the chain 54, and provide lubrication for the chain 54, the primary sprocket 36, and the secondary sprocket 72. Any fluid which drips off of the chain 54, primary sprocket 36, or secondary sprocket 72 will return to the dry sump 194, where the fluid will the be re-circulated by the gerotor pump 188. Lubricating the chain 54 through the use of the third fluid passage 200 improves the efficiency of the transfer case 10, and eliminates drag which would occur if the chain 54 were lubricated by feeding the chain 54 through a bath of fluid to provide splash lubrication.

In an alternate embodiment, oil feed holes 196 are formed in the secondary output shaft 86 in proximity to the secondary sprocket 72, and are also formed in the secondary sprocket 72, allowing the gerotor pump 188 to provide lubrication to the secondary sprocket 72 and chain 54 through the secondary output shaft 86, and the secondary sprocket 72.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

CLAIMSWhat is claimed is:

1. A transfer case, comprising: a primary output member; a secondary output member, driven for rotation by said primary output member; an output element operable for selectively receiving rotational force from said secondary output member; a clutch assembly for selectively transferring rotational force from said secondary output member to said output element; and a pump for providing lubrication to said clutch assembly, said primary output member, and said secondary output member, and as said secondary output member rotates, said pump will deliver lubrication to said primary output member, said secondary output member, and said clutch assembly.

2. The transfer case of claim 1 , further comprising: a primary sprocket circumscribing and fixed for rotation with said primary output member; a secondary sprocket circumscribing and fixed for rotation with said secondary output member; and a chain disposed about a portion of said primary sprocket and a portion of said secondary sprocket for transferring rotational force from said primary sprocket to said secondary sprocket.

3. The transfer case of claim 1 , said clutch assembly further comprising: a first series of clutch plates rotatable with said output element; a second series of clutch plates rotatable with said secondary output member, said second series of clutch plates interleaved with said first series of clutch plates; an apply plate for selectively applying a force to said first series of clutch plates and said second series of clutch plates, said apply plate having at least one recess for at least partially receiving at least one load transferring member; a cam plate having at least one corresponding recess for at least partially receiving said at least one load transferring member; and an electromagnetic assembly for initiating relative rotation between said cam plate and said apply plate such that when said electromagnetic assembly is actuated, said cam plate will rotate relative to said apply plate, causing said at least one load transferring member to move in said at least one recess of said apply plate and said at least one recess of said cam plate, thereby causing said apply plate to apply force to said first series of clutch plates and said second series of clutch plates, causing said second series of clutch plates and said secondary output member to transfer rotational force to said first series of clutch plates and said output element.

4. The transfer case of claim 3, said clutch assembly further comprising: said electromagnetic assembly including a housing surrounding an electromagnetic coil, and at least one extension extending through said output element and connected to a secondary apply plate; and a secondary clutch pack having a third series of clutch plates rotatable with said cam plate, and a fourth series of clutch plates rotatable with said output element, said at least one extension extending through said clutch pack such that when a current is applied to said electromagnetic coil, said at least one extension and said secondary apply plate will compress said secondary clutch pack, causing said cam plate to rotate relative to said apply plate.

5. The transfer case of claim 1 , further comprising a dry sump in fluid communication with said pump and said clutch assembly, and said pump is operable with said secondary output member such that as said secondary output member rotates, said pump will transfer fluid from said dry sump to said clutch assembly, said primary output member, and said secondary output member.

6. The transfer case of claim 5, further comprising: a clutch housing surrounding said clutch assembly; a bore disposed within said secondary output shaft; at least one oil feed hole for placing said clutch assembly in fluid communication with said bore; a first fluid passage connected to said dry sump and said pump; and a second fluid passage connected to both of said pump and a third fluid passage, and as said secondary output member rotates, said pump will draw fluid from said dry sump through said first fluid passage, said pump will deliver fluid to said bore where fluid will then flow through said at least one oil feed hole to said clutch assembly, and then through said clutch housing, to said drain passage, and to said dry sump, said pump will also deliver fluid to said second fluid passage, where fluid will then flow through said third fluid passage and onto said primary output member and said secondary output member.

7. The transfer case of claim 1 , said pump further comprising a gerotor pump.

8. The transfer case of claim 1 , wherein said clutch assembly is electromagnetically actuated, hydraulically actuated, or electrically actuated.

9. A transfer case having dry sump lubrication, comprising: a primary output member disposed within, and extending through a housing; a secondary output member rotatable with said primary output member; an output element selectively engageable with said secondary output member; a clutch assembly which selectively engages said output element with said secondary output member such that when said clutch assembly is not actuated, said secondary output member will not transfer rotational force to said output element, when said clutch assembly is actuated, said secondary output member will transfer rotational force to said output element; and a pump mounted on said secondary output member, operably associated with a dry sump, and as said secondary output member rotates, said pump will transfer fluid from said dry sump to said clutch assembly, said primary output member, and said secondary output member.

10. The transfer case having dry sump lubrication of claim 9, said clutch assembly further comprising: a clutch pack having a first series of clutch plates rotatable with said output element through a spline connection, and a second series of clutch plates interleaved with said first series of clutch plates, said second series of clutch plates rotatable with said secondary output member through a spline connection; an apply plate having a series of recesses for receiving a series of load transferring balls; a cam plate having a series of recesses for receiving said series of load transferring balls; and an electromagnetic assembly having a housing surrounding an electromagnetic coil, and a series of extensions extending through a secondary clutch pack and said output element, said series of extensions connected to a secondary apply plate, and said secondary clutch pack operably associated with said cam plate such that when a current is applied to said electromagnetic coil, said series of extensions and said secondary apply plate will compress said secondary clutch pack, causing said cam plate to rotate relative to said apply plate and said series of load transferring balls to rotate in said series of recesses in said cam plate and said series of recesses in said apply plate, causing said apply plate to compress said clutch pack, and said secondary output member to transfer rotational force to said output element.

11. The transfer case having dry sump lubrication of claim 10, said secondary clutch pack further comprising: a third series of clutch plates rotatable with said cam plate through a spline connection; and a fourth series of clutch plates rotatable with said output element through a spline connection, said fourth series of clutch plates interleaved with said third series of clutch plates, wherein a current is applied to said electromagnetic coil to cause said secondary apply plate to compress said third series of clutch plates and said fourth series of clutch plates.

12. The transfer case having dry sump lubrication of claim 9, further comprising: a first fluid passage for placing said dry sump in fluid communication with said pump; a bore formed in said secondary output member, said bore in fluid communication with a series of oil feed holes, said series of oil feed holes operable for delivering fluid to said clutch assembly; a second fluid passage for receiving fluid from said pump; and a third fluid passage operably connected to said second fluid passage, and as said secondary output member rotates, said pump will draw fluid from said dry sump through said first fluid passage, and deliver fluid through said bore and said second fluid passage, where fluid delivered through said bore will flow through said series of oil feed holes to said clutch assembly and fluid delivered through said second passage will flow into said third passage to said primary output member and said secondary output member.

13. The transfer case having dry sump lubrication of claim 12, further comprising a drain passage, and fluid flows through said drain passage to said dry sump after fluid has lubricated said clutch assembly.

14. The transfer case having dry sump lubrication of claim 9, said pump further comprising a gerotor pump.

15. The transfer case having dry sump lubrication of claim 9, wherein said clutch assembly is electromagnetically actuated, hydraulically actuated, or electrically actuated.

16. A transfer case having dry sump lubrication, comprising: a primary output shaft extending through, and rotatable within, a housing; a secondary output shaft, rotatable within and extending through said housing for receiving rotational force from said primary output shaft; a clutch assembly having a clutch pack, an apply plate operably associated with said clutch pack, a cam plate operably associated with said apply plate, and a series of load transferring balls disposed within a series of recesses on said cam plate, and a series of recesses on said apply plate; a primary sprocket rotatable with said primary output shaft; a secondary sprocket rotatable with said secondary output shaft; a chain partially circumscribing said primary sprocket and said secondary sprocket, said chain for transferring rotational force from said primary sprocket to said secondary sprocket, and as said primary output shaft rotates, said primary sprocket will transfer rotational force to said secondary sprocket through said chain, causing said secondary output shaft to rotate; and a dry sump operably associated with a gerotor pump, said gerotor pump mounted about said secondary output shaft, and as said secondary output shaft rotates, said gerotor pump will transfer fluid from said dry sump and deliver fluid to said chain, said primary sprocket, and said secondary sprocket.

17. The transfer case having dry sump lubrication of claim 16, further comprising: an output element operably associated with said clutch pack; said clutch pack having a first series of clutch plates rotatable with said output element, a second series of clutch plates rotatable with said secondary output shaft, said second series of clutch plates interleaved with said first series of clutch plates; an electromagnetic assembly including a housing surrounding an electromagnetic coil, and at least one extension extending through said output element and connected to a secondary apply plate; and a secondary clutch pack having a third series of clutch plates rotatable with said cam plate, and a fourth series of clutch plates rotatable with said output element, said at least one extension extending through said secondary clutch pack such that when said electromagnetic assembly is actuated, a current will be applied to said electromagnetic coil, attracting said a least one extension toward said electromagnetic coil and causing said secondary apply plate to compress said secondary clutch pack, thereby causing said cam plate to rotate relative to said apply plate, said series of load transferring balls to roll in said series of recesses of said apply plate and said series of recesses in said cam plate, thereby causing said apply plate to transfer along said secondary output shaft and compress said clutch pack.

18. The transfer case having dry sump lubrication of claim 16, further comprising: a first fluid passage for placing said gerotor pump in fluid communication with said dry sump; a second fluid passage in fluid communication with said gerotor pump and in fluid communication with a third fluid passage such that said gerotor pump will deliver fluid through said second fluid passage and said third fluid passage where fluid will be delivered from said third fluid passage onto said chain, and as said chain rotates about said primary sprocket and said secondary sprocket, fluid will be delivered to said primary sprocket and said secondary sprocket; and a bore disposed within said secondary output shaft, said bore in fluid communication with a series of oil feed holes, said series of oil feed holes in fluid communication with said clutch pack, and as said secondary output shaft rotates, said gerotor pump will draw fluid from said dry sump through said first fluid passage, and deliver fluid to said bore where fluid will then flow through said series of oil feed holes to said clutch pack.

19. The transfer case having dry sump lubrication of claim 16, wherein said clutch assembly is electromagnetically actuated, hydraulically actuated, or electrically actuated.