WO2018111278A1

WO2018111278A1 - Starter disconnect assembly and starter system including same

Info

Publication number: WO2018111278A1
Application number: PCT/US2016/066932
Authority: WO
Inventors: Dean Jeffrey Schneider; Christopher Blair
Original assignee: Borgwarner Inc.
Priority date: 2016-12-15
Filing date: 2016-12-15
Publication date: 2018-06-21

Abstract

A starter system is used in a vehicle for starting an internal combustion engine. The starter system includes a starter motor, a flex plate or flywheel, and a starter disconnect assembly including a ring gear disposed about a longitudinal axis, a band clutch rotatably coupled to the flex plate or flywheel and selectively rotatably coupled to the ring gear and adapted to provide a band centrifugal force, and an activation assembly. The activation assembly includes an activation arm adapted to move from an arm centrifugal force acting outward from the longitudinal axis, and a biasing member adapted to provide a biasing force to bias the activation arm toward the longitudinal axis. The activation arm is adapted to move between a first arm position for rotatably coupling the band clutch to the ring gear, and a second arm position for rotatably uncoupling the band clutch from the ring gear.

Description

STARTER DISCONNECT ASSEMBLY AND STARTER SYSTEM

INCLUDING SAME

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The invention generally relates to a starter disconnect assembly for use in a starter system of a vehicle.

2. Description of the Related Art

[0001] Vehicles include an internal combustion engine and a transmission. The internal combustion engine includes an engine block and a crankshaft rotatable with respect to the engine block. When the transmission is an automatic transmission, the vehicle also includes a flex plate or flywheel rotatably coupled to the crankshaft. When the transmission is a manual transmission, the vehicle includes a flywheel rotatably coupled to the crankshaft. In some applications, the vehicle also includes a starter system for starting the internal combustion engine by turning the crankshaft.

[0002] Conventional starter systems typically include a starter motor coupled to the engine block, with the starter motor having a pinion gear rotatable with respect to the engine block. Conventional starter systems also typically include a starter disconnect assembly, with the starter disconnect assembly including a ring gear rotatably coupled to the pinion gear of the starter motor, and rotatably coupled to the flex plate or the flywheel. The starter motor rotates the ring gear through the pinion gear which, in turn, transfers rotational motion to the crankshaft to start the internal combustion engine. [0003] However, when using conventional starter systems, rotation of the crankshaft caused by the internal combustion engine while running prohibits the starter motor from remaining rotatably coupled to the ring gear. In such conventional starter systems, the starter motor rotatably uncouples from the ring gear by using linear actuation of either the pinion gear or the ring gear.

[0004] Recent developments in starter systems have allowed the pinion gear of the starter motor to remain permanently rotatably coupled with the ring gear. Such starter systems are referred to as permanently engaged starter systems (PES systems). Conventional PES systems use other mechanisms and/or additional components, such as a one-way clutch mechanism, to rotatably uncouple the starter motor from the ring gear and in turn the crankshaft. Such one-way clutch mechanisms include additional components, such as multiple sprags or rollers, which adds additional costs to conventional PES systems. Additionally, such one-way clutch mechanisms are susceptible to failure after extended use. As such, there remains a need for a starter system using fewer components than conventional PES systems. Additionally, there remains a need for a lighter starter system. Further, there remains a need for a starter system that is more robust than conventional PES systems.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0005] A starter system is used in a vehicle that includes a transmission, and an internal combustion engine including an engine block and a crankshaft rotatable with respect to the engine block. The starter system includes a starter motor, and a flex plate or a flywheel adapted to be rotatably coupled to the crankshaft for transferring rotational motion from the crankshaft to the transmission. The starter system additionally includes a starter disconnect assembly. The starter disconnect assembly includes a ring gear rotatably coupled to the starter motor. The ring gear extends along and is disposed about a longitudinal axis. The starter disconnect assembly further includes a band clutch disposed about the longitudinal axis and rotatably coupled to the flex plate or the flywheel and selectively rotatably coupled to the ring gear. The band clutch is adapted to provide a band centrifugal force outward from the longitudinal axis during rotation of the flex plate or the flywheel for biasing the band clutch to uncouple from the ring gear. The starter disconnect assembly additionally includes an activation assembly. The activation assembly includes an activation arm coupled to the flex plate or the flywheel. The activation arm is adapted to move from an arm centrifugal force acting outward from the longitudinal axis on the activation arm during rotation of the flex plate or the flywheel for biasing the activation arm outward from the longitudinal axis. The activation assembly also includes a biasing member coupled to the flex plate or the flywheel and the activation arm. The biasing member is adapted to provide a biasing force to the activation arm to bias the activation arm toward the longitudinal axis. The activation arm is adapted to move between a first arm position where the biasing member provides the biasing force to the activation arm to transfer a normal force through the activation arm to the band clutch, with the biasing force being greater than the arm centrifugal force for biasing the band clutch toward the longitudinal axis and rotatably coupling the band clutch to the ring gear, and a second arm position where the arm centrifugal force is greater than the biasing force provided by the biasing member for allowing the band centrifugal force to rotatably uncouple the band clutch from the ring gear.

[0006] Accordingly, the starter disconnect assembly of the starter system including the activation assembly and band clutch uses fewer components than known PES systems. Additionally, the starter disconnect assembly of the starter system is lighter than known PES systems. Furthermore, the starter disconnect assembly of the starter system is more robust than conventional PES systems.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description, when considered in connection with the accompanying drawings wherein:

[0008] FIG. 1 is a perspective view of a vehicle, with the vehicle including a transmission and an internal combustion engine both shown in phantom;

[0009] FIG. 2 is a perspective view of the internal combustion engine, with the internal combustion engine including an engine block and a crankshaft shown in phantom;

[0010] FIG. 3 is a perspective view of a starter system of the vehicle, with the starter system including a starter motor and a starter disconnect assembly, and with the vehicle including a torque converter;

[0011] FIG. 4 is a perspective view of a flex plate or a flywheel of the starter system and the starter disconnect assembly, with the starter disconnect assembly including a ring gear;

[0012] FIG. 5 is an exploded view of the flex plate or the flywheel of the starter system and the starter disconnect assembly, with the starter disconnect assembly including the ring gear, a band clutch, an outer limiter, a bushing, a bushing support, a retainer, and an activation assembly, with the activation assembly including an activation arm, a biasing member, a band pin, and a pivot pin; [0013] FIG. 6 is a cross-sectional view of the flex plate or the flywheel of the starter system and the starter disconnect assembly taken along line 6-6 of FIG. 4;

[0014] FIG. 7 is a perspective view of the starter disconnect assembly;

[0015] FIG. 8 is a is a perspective view of the flex plate or the flywheel of the starter system and the starter disconnect assembly, with the ring gear, the bushing, the bushing support, and the retainer of the starter disconnect assembly removed;

[0016] FIG. 9 is a perspective view of the starter disconnect assembly, with the bushing support removed;

[0017] FIG. 10 is a perspective view of the starter disconnect assembly, with the bushing support and the outer limiter removed;

[0018] FIG. 11 is a perspective view of the starter disconnect assembly, with the bushing support, the outer limiter, and the retainer removed;

[0019] FIG. 12 is a perspective view of the band clutch and the activation assembly of the starter disconnect assembly;

[0020] FIG. 13 is a perspective view of the ring gear, the band clutch, and the activation assembly, with the activation arm in a first arm position, and with the band clutch rotatably coupled to the ring gear;

[0021] FIG. 14 is a perspective view of the ring gear, the band clutch, and the activation assembly, with the activation arm in a second arm position, and with the band clutch rotatably uncoupled from the ring gear; and

[0022] FIG. 15 is a perspective view of the flex plate or the flywheel of the starter system and the starter disconnect assembly, with the ring gear, bushing, bushing support, and retainer removed. DETAILED DESCRIPTION OF THE INVENTION

[0023] With reference to the Figures, wherein like numerals indicate like parts throughout the several views, a vehicle 20 is generally shown in FIG. 1. The vehicle 20 includes a transmission 22 and an internal combustion engine 24. The vehicle 20 defines an engine compartment 26 and a cabin 28, with the internal combustion engine 24 disposed within the engine compartment 26. As best shown in FIG. 2, the internal combustion engine 24 has an engine block 30 and a crankshaft 32 rotatable with respect to the engine block 30. One having ordinary skill in the art will appreciate that the internal combustion engine 24 and the engine block 30 shown throughout the Figures are merely illustrative and that the internal combustion engine 24 may be any suitable internal combustion engine 24. Additionally, one having ordinary skill in the art will appreciate that the crankshaft 32 shown throughout the Figures is merely illustrative and that the crankshaft 32 may have any other suitable configuration.

[0024] As best shown in FIG. 3, the vehicle 20 may include a torque converter

34. When present, the torque converter 34 is coupled to the transmission 22 and transmits rotational motion from the crankshaft 32 of the internal combustion engine 24 to the transmission 22. One having ordinary skill in the art will appreciate that the torque converter 34 shown in FIG. 3 is merely illustrative and that the torque converter 34 may be any suitable torque converter 34.

[0025] As shown in FIG. 3, the vehicle 20 includes a starter system 36 for starting the internal combustion engine 24 by rotating the crankshaft 32. The starter system 36 includes a starter motor 38. In some embodiments, the starter motor 38 is coupled to the engine block 30. One having ordinary skill in the art will appreciate that the starter motor 38 may be coupled to the engine block 30 in any suitable location and is not limited to the location as shown throughout the Figures. One having ordinary skill in the art will appreciate that the starter motor 38 may be adapted to be coupled to any suitable component of the vehicle 20.

[0026] With reference to FIGS. 4-6, the starter system 36 also includes an intermediate rotational component 40 adapted to be rotatably coupled to the crankshaft 32 for transferring rotational motion from the crankshaft 32 to the transmission 22. The intermediate rotational component 40 may be a flex plate 40 or a flywheel 40 adapted to be rotatably coupled to the crankshaft 32 for transferring rotational motion from the crankshaft 32 to the transmission 22. Specifically, when the transmission 22 in the vehicle 20 is an automatic transmission, the torque converter 34 includes the flex plate 40 as the intermediate rotational component 40 rotatably coupled to the crankshaft 32 for transferring rotational motion to the transmission 22. On the other hand, when the transmission 22 in the vehicle 20 is a manual transmission, the vehicle 20 includes the flywheel 40 as the intermediate rotational component rotatably coupled to the crankshaft 32. Additionally, when the transmission 22 in the vehicle is a dual clutch transmission, the vehicle 20 includes the flywheel 40 as the intermediate rotational component. It is to be appreciated that the intermediate rotational component 40 shown throughout the Figures is merely illustrational and represents both a flex plate and a flywheel. It is also to be appreciated that the flex plate 40 referred to throughout the written description may also refer to the flywheel 40.

[0027] With reference to FIGS. 5-7, the starter system 36 also includes a starter disconnect assembly 42. The starter disconnect assembly 42 includes a ring gear 44 adapted to be rotatably coupled to the starter motor 38. The ring gear 44 extends along and is disposed about a longitudinal axis A. The ring gear 44 may define a plurality of ring teeth 46 about the longitudinal axis A. Typically, when the ring gear 44 defines the plurality of ring teeth 46, the starter motor 38 may have a pinion gear (not shown) coupled to the ring teeth 46 for rotating the ring gear 44. One having ordinary skill in the art will appreciate that the ring gear 44 may be rotatable and driven by the starter motor 38 in any suitable manner, such as belt driven, chain driven, and rubber wheel driven. Typically, the ring gear 44 is disposed between the internal combustion engine 24 and the torque converter 34 when the transmission 22 is an automatic transmission, and the ring gear 44 is disposed between the internal combustion engine 24 and the flywheel 40 when the transmission 22 is a manual transmission.

[0028] The starter disconnect assembly 42 further includes a band clutch 48 disposed about the longitudinal axis A. The band clutch 48 is adapted to be rotatably coupled to the flex plate 40 and selectively rotatably coupled to the ring gear 44. For example, when the internal combustion engine 24 is turned off and needs to be turned on, the starter motor 38 rotates the ring gear 44 and the band clutch 48, which then rotates the flex plate 40 and the crankshaft 32 to turn on the internal combustion engine 24. Once certain conditions are met, such as a predetermined angular velocity of the flex plate 40 and crankshaft 32, the band clutch 48 rotatably uncouples from the ring gear 44, as described in further detail below. The band clutch 48 is adapted to provide a band centrifugal force BCF outward from the longitudinal axis A during rotation of the flex plate 40 for biasing the band clutch 48 to uncouple from the ring gear 44.

[0029] The starter disconnect assembly 42 additionally includes an activation assembly 50, as best shown in FIGS. 5 and 12-14. The activation assembly 50 includes an activation arm 52 adapted to be coupled to the flex plate 40. The activation arm 52 is adapted to move from an arm centrifugal force AF acting outward from the longitudinal axis A on the activation arm 52 during rotation of the flex plate 40 for biasing the activation arm 52 outward from the longitudinal axis A. The activation assembly 50 also includes a biasing member 54 coupled to the activation arm 52 and adapted to be coupled to the flex plate 40. The biasing member 54 is adapted to provide a biasing force BF to the activation arm 52 to bias the activation arm 52 toward the longitudinal axis A. It is to be appreciated that the biasing member 54 may be any suitable biasing member for providing the biasing force BF to the activation arm 52. As non limiting examples, the biasing member 54 may be an actuator, a magnetic biasing member, a rubber bumper, or a spring.

[0030] The activation arm 52 is adapted to move between a first arm position, as shown in FIG. 13, and a second arm position, as shown in FIG. 14. Typically, the activation arm 52 is in the first arm position during an engine starting event, which occurs when the internal combustion engine 24 is turned off and needs to be turned on, and is in the second arm position when the internal combustion engine 24 is running. When the activation arm 52 is in the first arm position, the biasing member 54 provides the biasing force BF to the activation arm 52 to transfer a normal force F through the activation 52 arm to the band clutch 48, with the biasing force BF being greater than the arm centrifugal force AF. Having the biasing force BF greater than the arm centrifugal force AF biases the band clutch 48 toward the longitudinal axis A and rotatably couples the band clutch 48 to the ring gear 44. The normal force NF biases the band clutch 48 toward the longitudinal axis A. When the activation arm 52 is in the second arm position, the arm centrifugal force AF is greater than the biasing force BF provided by the biasing member 54 for allowing the band centrifugal force BCF to rotatably uncouple the band clutch 48 from the ring gear 44. [0031] The starter disconnect assembly 42 of the starter system 36 including the activation assembly 50 and the band clutch 48 allows the starter disconnect assembly 42 to use fewer components than known PES systems. The starter disconnect assembly 42 uses the centrifugal force provided by the rotation of the flex plate 40 to selectively rotatably couple the ring gear 44 to the flex plate 40 and thus the crankshaft 32, as described above and as further described below. Using the centrifugal force generated by components, specifically the activation arm 52 and the band clutch 48, and the biasing force BF provided by the biasing member 54 allows the starter disconnect assembly 42 to operate without the need for additional activation components, such as piston a one-way clutch mechanism, which are typically used in conventional starter systems. Such one-way clutch mechanisms typically include multiple sprags or rollers. Having multiple sprags and rollers not only increases the number of components, but it also decreases the cycle life of conventional starter systems. Further, when higher torque is applied in conventional starter systems, the sprags, rollers, and races of the one-way clutch are susceptible to breaking. The starter disconnect assembly 42 of the starter system 36 is more robust than conventional starter systems because the starter disconnect assembly 42 and, specifically, the band clutch 48, is able to handle higher torque without breaking. Additionally, as the band clutch 48 begins to wear after numerous cycles, the starter disconnect assembly 42 will continue to work, whereas conventional starter systems begin to break due to components, such as multiple sprags, rollers, and races, breaking. Furthermore, conventional starter systems often have problems with contamination within the starter disconnect assembly as a result of components, such as multiple sprags, rollers, and races, wearing down, which can cause the oneway clutch mechanism to slip. The starter disconnect assembly 42 has fewer components, and due to the band clutch 48, will continue to work after numerous cycles. Additionally, the starter disconnect assembly 42 of the starter system 36 including the activation assembly 50 and the band clutch 48 allows the starter motor 38 to remain continuously rotatably coupled with the ring gear 44 under all operating conditions. Additionally, the starter disconnect assembly 42 is lighter than known PES systems due, in part, to requiring fewer components for operation.

[0032] As described above, when the activation arm 52 is in the first arm position, the band clutch 48 is rotatably coupled to the ring gear 44, which rotatably couples the ring gear 44 to the flex plate 40 and thus to the crankshaft 32 for starting the internal combustion engine 24. When the internal combustion engine 24 is turned off and the crankshaft 32 is not rotating, the biasing force BF provided by the biasing member 54 to the activation arm 52 to transfer the normal force NF through the activation arm 52 to the band clutch 48 keeps the band clutch 48 rotatably coupled to the ring gear 44. During an engine starting event, the starter motor 38 rotates the ring gear 44. The band clutch 48 may self-couple to the ring gear 44 when the ring gear 44 attempts to rotate faster than the crankshaft 32. In other words, the band clutch 48 is arranged such that when the starter motor 38 is forcibly rotating the crankshaft 32, a friction force between the band clutch 48 and the ring gear 44 is in a first direction that tends to wind the band clutch 48 around the ring gear 44, thus further engaging the band clutch 48 to the ring gear 44. As the ring gear 44 rotates and while the band clutch 48 is still rotatably coupled to the ring gear 44, the flex plate 40 rotates the crankshaft 32. When the crankshaft 32 begins to rotate faster than the ring gear 44, the friction force between the band clutch 48 and the ring gear 44 is in a second direction opposite the first direction that tends to unwind the band clutch 48 from the ring gear 44.

[0033] As the internal combustion engine 24 transitions from a starting event to reach idle speed, the arm centrifugal force AF begins to increase to overcome the biasing force BF provided by the biasing member 54, which begins to rotatably uncouple the band clutch 48 from the ring gear 44, and, in turn, the crankshaft 32 from the ring gear 44. The movement of the activation arm 52 from the first arm position to the second arm position reduces the normal force NF provided by the activation arm 52 on the band clutch 48. It is to be appreciated that the arm centrifugal force AF may overcome the biasing force BF provided by the biasing member 54 at any predetermined rotational speed from the ring gear 44 and is not limited to the arm centrifugal force AF overcoming the biasing force BF at the idle speed of the internal combustion engine 24. As the crankshaft 32 continues to rotate at the predetermined rotational speed, for example the idle speed, or greater, the arm centrifugal force AF remains greater than the biasing force BF provided by the biasing member 54 and continues to rotatably uncouple the band clutch 48 from the ring gear 44. This allows the band clutch 48 to rotate with the flex plate 40, and allows the ring gear 44 to rotate slower than the flex plate 40 or stop rotating entirely. The rotatably uncoupling of the band clutch 48, and, in turn, the flex plate 40 and crankshaft 32, from the ring gear 44 allows the starter motor 38 to remain rotatably coupled to the ring gear 44 under all operating conditions. It is to be appreciated that the activation arm 52 may move from the first arm position toward to second arm position once the crankshaft 32 of the internal combustion engine 24 has reached any suitable predetermined angular velocity. It is to be appreciated that the activation arm 52 may be adapted to move by the arm centrifugal force AF being greater than the biasing force BF provided by the biasing member 54 at any suitable predetermined angular velocity of the flex plate 40 and crankshaft 32. Allowing the band clutch 48 to rotatably uncouple from the ring gear 44 allows the starter motor 38 to remain rotatably coupled to the ring gear 44 under all operating conditions without burning out the starter motor 38 from the ring gear 44 rotating too fast. [0034] When the internal combustion engine 24 turns off, the band clutch 48 rotatably couples to the ring gear 44, as best shown in FIG. 14. Specifically, when the internal combustion engine 24 approaches shut off such that the angular velocity of the crankshaft 32 and the flex plate 40 approaches zero, the band clutch 48 rotatably couples to the ring gear 44. The band clutch 48 rotatably couples to the ring gear 44 whenever the band centrifugal force BCF is insufficient to rotatably uncouple the band clutch 48 from the ring gear 44. Additionally, when the biasing force BF provided by the biasing member 54 is greater than the arm centrifugal force AF acting on the activation arm 52, the activation arm 52 may further bias the band clutch 48 to rotatably couple to the ring gear 44. At this point, the internal combustion engine 24 is turned off and another starting event can occur. It is to be appreciated that the biasing force BF may be normal with respect to the activation arm 52, may be normal with respect to longitudinal axis A, or may be at any suitable angle with respect to the activation arm 52.

[0035] The band clutch 48 may be referred to as being in a first clutch position when the band clutch 48 is rotatably coupled to the ring gear 44, as shown in FIG. 13, and may be referred to as being in a second clutch position when the band clutch 48 is rotatably uncoupled from the ring gear 44, as shown in FIG. 14. Specifically, when the band clutch 48 is rotatably uncoupled from the ring gear 44, the band clutch 48 and the ring gear 44 define a clearance C therebetween, as shown in FIG. 13.

[0036] In one embodiment, the ring gear 44 has a hub 56 extending along the longitudinal axis A, with the band clutch 48 engageable with the hub 56 to selectively rotatably couple the band clutch 48 to the ring gear 44, as described above and as shown in FIGS. 6 and 13-14. It is to be appreciated that the hub 56 may be integral with the ring gear 44 or may be a separate component without departing from the nature of the present invention. When present, the hub 56 is permanently coupled to the ring gear 44 such that the hub 56 rotates with the ring gear 44.

[0037] As best shown in FIGS. 10-14, the band clutch 48 may have an outer band

58 defining a band channel 60, and an inner band 62 slidably disposed within the band channel 60. When the band clutch 48 has the outer band 58 and the inner band 62, the band clutch 48 may be referred to as a double wrap band. When present, the inner band 62 is moveable between a first band position for rotatably coupling the band clutch 48 to the ring gear 44 when the activation arm 52 is in the first arm position, as shown in FIG. 13, and a second band position for rotatably uncoupling the band clutch 48 from the ring gear 44 when the activation arm 52 is in the second arm position, as shown in FIG. 14. It is to be appreciated that the band clutch 48 may have any other suitable configuration. For example, the band clutch 48 may be a helical band clutch or a coil band clutch.

[0038] In one embodiment, the activation assembly 50 may include a band pin 64 adapted to be coupled to the flex plate 40. In this embodiment, the band clutch 48 has a fixed end 66 that is adapted to be fixed to the flex plate 40 by the band pin 64, and a free end 67 moveable with respect to the longitudinal axis A by the activation arm 52 as the activation arm 52 moves between the first and second arm positions for selectively rotatably coupling the band clutch 48 to the ring gear 44. The band pin 64 may be fixed to the flex plate 40 such that the band pin 64 rotates with the flex plate 40. In this embodiment, the biasing member 54 provides the biasing force BF to the activation arm 52 to transfer the normal force F through the activation arm 52 to the free end 67 of the band clutch 48.

[0039] With reference to FIGS. 10-14, the activation assembly 50 may include a pivot pin 68 adapted to be coupled to the flex plate 40, with the activation arm 52 pivotably coupled to the pivot pin 68 for moving between the first and second arm positions for selectively rotatably coupling the band clutch 48 to the ring gear 44. The band clutch 48 may have a pair of engagement tabs 65 for coupling the band clutch 48 to the band pin 64. In one embodiment, as described above, the biasing member 54 is a spring. In this embodiment, the biasing member 54 is nested around the pivot pin 68 and coupled to the flex plate 40. The biasing member 54 biases the activation arm 52 toward the longitudinal axis A.

[0040] The activation arm 52 may have a cam portion 70 adjacent the pivot pin

68. In such embodiments, the cam portion 70 may be pivotable about the pivot pin 68 as the activation arm 52 moves between the first arm position for moving the band clutch 48 toward the longitudinal axis A and rotatably coupling the band clutch 48 to the ring gear 44, and the second arm position for allowing the band centrifugal force BCF to rotatably uncouple the band clutch 48 from the ring gear 44. The cam portion 70 is typically engageable with the band clutch 48 when the activation arm 52 is in the first and second arm positions. Specifically, the cam portion 70 is typically engageable with the inner band 62 of the band clutch 48. In this embodiment, as best illustrated in FIGS. 13 and 14, the cam portion 70 slides the inner band 62 in the band channel 60 for rotatably coupling the band clutch 48 to the ring gear 44 and for rotatably uncoupling the band clutch 48 from the ring gear 44.

[0041] In one embodiment, the activation arm 52 has a projection 72 extending away from the pivot pin 68. The projection 72 may be adapted to move from the arm centrifugal force AF acting outward from the longitudinal axis A on the activation arm 52 during rotation of the flex plate 40 for biasing the activation arm 52 outward from the longitudinal axis A to rotatably uncouple the band clutch 48 from the ring gear 44 when the arm centrifugal force AF is greater than the biasing force BF provided by the biasing member 54. Specifically, in this embodiment and as shown in FIGS. 13 and 14, the projection 72 of the activation arm 52 induces a first torque Tl during rotation of the flex plate 40 for pivoting the projection 72 about the pivot pin 68, which moves the activation arm 52 from the first arm position to the second arm position. In this embodiment, the biasing member 54 provides the biasing force BF to the projection 72 of the activation arm 52 to induce a second torque T2 on the projection. When the second torque T2 overcomes the first torque Tl, the activation arm 52 moves to the first arm position. When the first torque Tl overcomes the second torque T2, the activation arm 52 moves from the first arm position to the second arm position. When the activation arm 52 is in the second arm position, the first torque Tl is no longer sufficient to keep the activation arm 52 in the first arm position, which allows the band clutch 48 to centrifugally expand to rotatably uncouple from the ring gear 44.

[0042] The projection 72 may have a finger portion 74 extending from the pivot pin 68, with the finger portion 74 having a finger thickness FT, as shown in FIG. 10. The finger portion 74 may have a projection distal end 76 having a mass portion 78 spaced from the pivot pin 68. When present, the mass portion 78 typically has a greater thickness than the finger portion 74 to increase the arm centrifugal force AF acting outward from the longitudinal axis A on the activation arm 52 during rotation of the flex plate 40 for biasing the activation arm 52 outward from the longitudinal axis A to rotatably uncouple the band clutch 48 from the ring gear 44 when the arm centrifugal force AF is greater than the biasing force BF. It is to be appreciated that the projection 72 of the activation arm 52 may have any suitable configuration for providing a suitable arm centrifugal force AF. It is also to be appreciated that the mass portion 78 may be adjusted to increase the arm centrifugal force AF acting on the activation arm 52, as shown in FIGS. 8 and 10. [0043] The activation assembly 50 may include an outer limiter 80 adapted to be coupled to the flex plate 40. When present, the outer limiter 80 is adapted to limit movement of the band clutch 48 away from the longitudinal axis A after the band clutch 48 is rotatably uncoupled from the ring gear 44. Limiting movement of the band clutch 48 away from the longitudinal axis A after the band clutch 48 is rotatably uncoupled from the ring gear 44 prevents the band clutch 48 from contacting other components of the starter disconnect assembly 42 during rotation of the flex plate 40.

[0044] The outer limiter 80 may define an outer cavity 82, with the band pin 64 extending through the outer cavity 82 for coupling the band clutch 48 to the flex plate 40. The outer limiter 80 may define an outer channel 84, with the activation arm 52 moveable within the outer channel 84. Specifically, as the activation arm 52 moves between the first and second arm positions, the activation arm 52 moves within the outer channel 84. The outer channel 84 allows the outer limiter 80 to limit movement of the band clutch 48 away from the longitudinal axis A after the band clutch is rotatably uncoupled from the ring gear 44 and allows the activation arm 52 to move within the outer channel 84. When present, the cam portion 70 of the activation arm 52 may be moveable within the outer channel 84 for providing the normal force F to the band clutch 48 as a result of the biasing force BF provided by the biasing member 54 to the activation arm 52. Typically, the outer limiter 80 is concentrically disposed about the band clutch 48. The outer limiter 80 may define an outer hole 86, with the pivot pin 68 disposed through the outer hole 86 and coupled to the flex plate 40.

[0045] The ring gear 44 may present an inner bushing surface 88 disposed about the longitudinal axis A. When present, the hub 56 of the ring gear 44 may present the inner bushing surface 88. The starter disconnect assembly 42 may further include a bushing 90 for rotatably supporting the ring gear 44. The bushing 90 may be coupled to the inner bushing surface 88 of the ring gear 44. In some embodiments, the starter disconnect assembly 42 further includes a bushing support 92 disposed about the longitudinal axis A, with the bushing 90 disposed between the bushing support 92 and the inner bushing surface 88. The starter disconnect assembly 42 may further include a retainer 94 disposed about the longitudinal axis. The retainer 94 is adapted to be coupled to the engine block 30. When present, the retainer 94 is typically coupled to the bushing support 92 for coupling the starter disconnect assembly 42 to the engine block 30. The retainer 94 may provide a radial pilot and axial face to retain the starter disconnect assembly 42 to the engine block 30. The bushing 90 bears on the bushing support 92 and the retainer 94 such that the bushing support 92 and the retainer 94 rotatably supporting the ring gear 44.

[0046] In one embodiment, as shown in FIG. 12, a connection assembly 96 for use in the starter disconnect assembly 42 of the starter system 36 of the vehicle 20 includes the band clutch 48, the activation arm 52, and the biasing member 54. In this embodiment, the band clutch 48 is adapted to be rotatably coupled to the flex plate 40 and selectively rotatably uncoupled from the ring gear 44, with the band clutch 48 extending along and disposed about the longitudinal axis A. Further, the band clutch 48 is adapted to provide the band centrifugal force BCF outward from the longitudinal axis A during rotation of the flex plate 40 for biasing the band clutch 48 to uncouple from the ring gear 44. Additionally, in this embodiment, the activation arm 52 is adapted to be coupled to the flex plate 40 and is adapted to move from the arm centrifugal force AF acting outward from the longitudinal axis A on the activation arm 52 during rotation of the flex plate 40 for biasing the activation arm 52 outward from the longitudinal axis A. Further, in this embodiment, the biasing member 54 is coupled to the activation arm 52 and is adapted to be coupled to the flex plate 40. The biasing member 54 is adapted to provide the biasing force BF to the activation arm 52 to bias the activation arm 52 toward the longitudinal axis A. The activation arm 52 is adapted to move between a first arm position and a second arm position. When the activation arm 52 is in the first arm position, the biasing member 54 provides the biasing force BF to the activation arm 52 to transfer the normal force F through the activation arm 52 to the band clutch 48, with the biasing force BF being greater than the arm centrifugal force AF. Having the biasing force BF greater than the arm centrifugal force AF biases the band clutch 48 toward the longitudinal axis A and rotatably couples the band clutch 48 to the ring gear 44. When the activation arm 52 is in the second arm position, the arm centrifugal force AF is greater than the biasing force BF provided by the biasing member 54 for allowing the band centrifugal force BCF to rotatably uncouple the band clutch 48 from the ring gear 44.

[0047] The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described.

Claims

CLAIMS What is claimed is:

1. A starter system for use in a vehicle including a transmission, and an internal combustion engine including an engine block and a crankshaft rotatable with respect to the engine block, said starter system comprising:

(A) a starter motor;

(B) a flex plate or a flywheel adapted to be rotatably coupled to the crankshaft for transferring rotational motion from the crankshaft to the transmission; and

(C) a starter disconnect assembly comprising,

(i) a ring gear rotatably coupled to said starter motor, with said ring gear extending along and disposed about a longitudinal axis,

(ii) a band clutch disposed about said longitudinal axis and rotatably coupled to said flex plate or said flywheel and selectively rotatably coupled to said ring gear, with said band clutch adapted to provide a band centrifugal force outward from said longitudinal axis during rotation of said flex plate or said flywheel for biasing said band clutch to uncouple from said ring gear, and

(iii) an activation assembly comprising,

(a) an activation arm coupled to said flex plate or said flywheel, with said activation arm adapted to move from an arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of said flex plate or said flywheel for biasing said activation arm outward from said longitudinal axis, and (b) a biasing member coupled to said flex plate or said flywheel and said activation arm, with said biasing member adapted to provide a biasing force to said activation arm to bias said activation arm toward said longitudinal axis, and with said activation arm adapted to move between,

a first arm position where said biasing member provides said biasing force to said activation arm to transfer a normal force through said activation arm to said band clutch, with said biasing force being greater than said arm centrifugal force for biasing said band clutch toward said longitudinal axis and rotatably coupling said band clutch to said ring gear, and

a second arm position where said arm centrifugal force is greater than said biasing force provided by said biasing member for allowing said band centrifugal force to rotatably uncouple said band clutch from said ring gear.

2. The starter system as set forth in claim 1, wherein said band clutch has an outer band defining a band channel, and an inner band slidably disposed within said band channel, with said inner band moveable between a first band position for rotatably coupling said band clutch to said ring gear when said activation arm is in said first arm position, and a second band position for rotatably uncoupling said band clutch from said ring gear when said activation arm is in said second arm position.

3. The starter system as set forth in any preceding claim, wherein said activation assembly further comprises a band pin coupled said flex plate or said flywheel, and wherein said band clutch has a fixed end that is fixed to said flex plate or said flywheel by said band pin, and a free end moveable with respect to said longitudinal axis by said activation arm as said activation arm moves between said first and second arm positions for selectively rotatably coupling said band clutch to said ring gear.

4. The starter system as set forth in any preceding claim, wherein said activation assembly further comprises a pivot pin coupled to said flex plate or said flywheel, with said activation arm pivotably coupled to said pivot pin for moving between said first and second arm positions for selectively rotatably coupling said band clutch to said ring gear.

5. The starter system as set forth in claim 4, wherein said activation arm has a cam portion adjacent said pivot pin, with said cam portion pivotable about said pivot pin as said activation arm moves between said first arm position for moving said band clutch toward said longitudinal axis and rotatably coupling said band clutch to said ring gear, and said second arm position for allowing said band centrifugal force to rotatably uncouple said band clutch from said ring gear.

6. The starter system as set forth in any of claims 4 and 5, wherein said activation arm has a projection extending away from said pivot pin, with said projection adapted to move from said arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of said flex plate or said flywheel for biasing said activation arm outward from said longitudinal axis to rotatably uncouple said band clutch from said ring gear when said arm centrifugal force is greater than said biasing force provided by said biasing member.

7. The starter system as set forth in claim 6, wherein said projection has a finger portion extending from said pivot pin and having a finger thickness, and a projection distal end having a mass portion spaced from said pivot pin, with said mass portion having a greater thickness than said finger portion to increase said arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of said flex plate or said flywheel for biasing said activation arm outward from said longitudinal axis to rotatably uncouple said band clutch from said ring gear when said arm centrifugal force is greater than said biasing force.

8. The starter system as set forth in any preceding claim, wherein said starter disconnect assembly further comprises an outer limiter coupled to said flex plate or said flywheel, with said outer limiter adapted to limit movement of said band clutch away from said longitudinal axis after said band clutch is rotatably uncoupled from said ring gear.

9. The starter system as set forth in any preceding claim, wherein said ring gear has a hub extending along said longitudinal axis, with said band clutch engageable with said hub to selectively rotatably couple said band clutch to said ring gear.

10. A vehicle comprising the starter system of claim 1 in combination with a transmission, wherein said transmission is an automatic transmission, and wherein an intermediate rotational component is said flex plate.

11. A starter disconnect assembly for use in a starter system of a vehicle, with the vehicle including a transmission, and an internal combustion engine including an engine block and a crankshaft rotatable with respect to the engine block, and with the starter system including a starter motor, and a flex plate or a flywheel rotatably coupled to the crankshaft, said starter disconnect assembly comprising:

a ring gear adapted to be rotatably coupled to the starter motor, with said ring gear extending along and disposed about a longitudinal axis;

a band clutch disposed about said longitudinal axis and adapted to be rotatably coupled to the flex plate or the flywheel and selectively rotatably coupled to said ring gear, with said band clutch adapted to provide a band centrifugal force outward from said longitudinal axis during rotation of the flex plate or the flywheel for biasing said band clutch to uncouple from said ring gear, and

an activation assembly comprising,

an activation arm adapted to be coupled to the flex plate or the flywheel, with said activation arm adapted to move from an arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of the flex plate or the flywheel for biasing said activation arm outward from said longitudinal axis, and

a biasing member coupled to said activation arm and adapted to be coupled to the flex plate or the flywheel, with said biasing member adapted to provide a biasing force to said activation arm to bias said activation arm toward said longitudinal axis, and with said activation arm adapted to move between,

12. The starter disconnect assembly as set forth in claim 11, wherein said band clutch has an outer band defining a band channel, and an inner band slidably disposed within said band channel, with said inner band moveable between a first band position for rotatably coupling said band clutch to said ring gear when said activation arm is in said first arm position, and a second band position for rotatably uncoupling said band clutch from said ring gear when said activation arm is in said second arm position.

13. The starter disconnect assembly as set forth in any one of claims 11 and 12, wherein said activation assembly further comprises a band pin adapted to be coupled to the flex plate or the flywheel, and wherein said band clutch has a fixed end that is adapted to be fixed to the flex plate or the flywheel by said band pin, and a free end moveable with respect to said longitudinal axis by said activation arm as said activation arm moves between said first and second arm positions for selectively rotatably coupling said band clutch to said ring gear.

14. The starter disconnect assembly as set forth in any one of claims 11 through 13, wherein said activation assembly further comprises a pivot pin adapted to be coupled to the flex plate or the flywheel, with said activation arm pivotably coupled to said pivot pin for moving between said first and second arm positions for selectively rotatably coupling said band clutch to said ring gear.

15. The starter disconnect assembly as set forth in claim 14, wherein said activation arm has a cam portion adjacent said pivot pin, with said cam portion pivotable about said pivot pin as said activation arm moves between said first arm position for moving said band clutch toward said longitudinal axis and rotatably coupling said band clutch to said ring gear, and said second arm position for allowing said band centrifugal force to rotatably uncouple said band clutch from said ring gear.

16. The starter disconnect assembly as set forth in any one of claims 14 and 15, wherein said activation arm has a projection extending away from said pivot pin, with said projection adapted to move from said arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of the flex plate or the flywheel for biasing said activation arm outward from said longitudinal axis to rotatably uncouple said band clutch from said ring gear when said arm centrifugal force is greater than said biasing force provided by said biasing member.

17. The starter disconnect assembly as set forth in claim 16, wherein said projection has a finger portion extending from said pivot pin and having a finger thickness, and projection distal end having a mass portion spaced from said pivot pin, with said mass portion having a greater thickness than said finger portion to increase said arm centrifugal force acting outward from said longitudinal axis on said activation arm during rotation of the flex plate or the flywheel for biasing said activation arm outward from said longitudinal axis to rotatably uncouple said band clutch from said ring gear when said arm centrifugal force is greater than said biasing force.

18. The starter disconnect assembly as set forth in any one of claims 11 through 17, further comprising an outer limiter adapted to be coupled to the flex plate or the flywheel, with said outer limiter adapted to limit movement of said band clutch away from said longitudinal axis after said band clutch is rotatably uncoupled from said ring gear.

19. The starter disconnect assembly as set forth in any one of claims 11 through 18, wherein said ring gear has a hub extending along said longitudinal axis, with said band clutch engageable with said hub to selectively rotatably couple said band clutch to said ring gear.

20. A connection assembly for use in a starter disconnect assembly of a starter system of a vehicle, with the vehicle including a transmission, and an internal combustion engine including an engine block and a crankshaft rotatable with respect to the engine block, with the starter system including a starter motor, and a flex plate or a flywheel rotatably coupled to the crankshaft, and with the starter disconnect assembly including a ring gear rotatably coupled to the starter motor, said connection assembly comprising: a band clutch adapted to be rotatably coupled to the flex plate or the flywheel and selectively rotatably coupled to the ring gear, with the band clutch extending along and disposed about a longitudinal axis, and with said band clutch adapted to provide a band centrifugal force outward from said longitudinal axis during rotation of the flex plate or the flywheel for biasing said band clutch to uncouple from the ring gear;