BALL RAMP DRIVE LINE CLUTCH ACTUATOR WITH UNIDIRECTIONAL APPLICATION
Background of the Invention 1. Field of the Invention The present invention relates to a drive line clutch of a vehicle and, more particularly, to a drive line clutch where a friction disk is attached to a motor flywheel using a ball ramp actuator. where planetary gear sets that have one-way clutches in the planetary gears provide the clutch lock of the line under driving and inertial running conditions. 2. Description of the Prior Art The master drive clutches normally use a plurality of springs to hold a friction disk to a motor flywheel. The springs are disposed within a pressure plate assembly that is screwed to the flywheel. A mechanical linkage that controls the spring mechanism of the pressure plate is moved by the operator to control the lock and release of the line clutch. Efforts are currently being made to automate the operation of the drive line clutch using electronic devices. It is known to use an electromechanical or hydraulic actuator connected to the mechanical linkage to, essentially, replace the operator to obtain a more precise operation of the clutch during the transmission changes. Using this actuator, the mechanical linkage moves in response to an electrical control signal generated by a central microprocessor used to process a variety of vehicle sensor inputs based on operating conditions to determine when and in what manner the line clutch The drive must be activated or deactivated. The use of a ball-ramp actuator for loading a clutch pack into a drive line differential of a vehicle is known. U.S. Patents 4,805,486 and 5,092,825, which are incorporated herein by reference, disclose limited slip differentials where a clutch pack is loaded in response to the activation of a ball-ramp actuator initiated by the rotation of a servo motor or a brake shoe driven by solenoid on an activation ring. The advantage of the ball-ramp mechanism in comparison with other actuators is that it converts the rotary movement into axial movement with a very high force amplification, often of 100: 1 or greater. A ball-ramp driver has also been used in a vehicle transmission to link and disengage the gear sets by loading a shift clutch package in response to a signal as described in U.S. Patent 5,078,249, which is incorporated here as a reference In these two vehicle applications, one side of the ball-ramp actuator, commonly called the control ring, reacts against the ground of the box through the force induced by an electromagnetic field generated by a coil or is rotated by an electric motor. in relation to cash land. To generate greater clamping forces, the electric current supplied to the coil or motor is increased, increasing accordingly the reaction of the control ring to the ground of the box that rotates to the control ring in relation to an actuation ring thus making the Rolling elements pass through the ramps in the control and actuation ring which increases the axial movement and clamping force on the clutch pack. It is also known to use a ball-ramp actuator for loading a drive line clutch of a vehicle as described in U.S. Patents 1,974,390; 2,861,225; 3,000,479; 5,441,137; 5,469,948; 5,485,904 and 5,505,285, which are incorporated herein by reference. A problem with the use of a ball-ramp actuator for supplying the clamping force of the drive line clutch is that the mechanics of the unidirectional ball-ramp mechanisms of the prior art result in a loss of clamping force when the vehicle is running by inertia. Once the motor power is reduced and that the drive line is really making the motor run freely (inertial gear mode), the ball ramp actuator of the prior art with single-ramp unidirectional drive will disengage the clutch thereby eliminating braking of the vehicle engine. A ball-operated clutch using a unidirectional ball ramp having only a single ramp angle will cause the clutch to disengage when the engine is not supplying rotary power in the transmission such as when the vehicle is inertial gear. When inertial, the flywheel is no longer supplying rotary power to the transmission or the ball-ramp actuator. In this circumstance, the relative rotation of the drive ring and the control ring has been reversed so that the axial displacement of the ball ramp is broken thus allowing the pressure plate to exit the clutch disk. The result is that the engine is unlinked from the transmission and any braking effect of the engine is eliminated. A bi-directional ball-operated clutch is described in U.S. Patent Nos. 2,937,729 and 5,505,285. Using this more expensive and complicated technology, the ball ramp actuator incorporates bidirectional ramps that provide activation when there is relative rotation between the control ring and the drive ring in any direction. However, the ball ramp must make a transition through the non-activated state which will result in undesirable temporary slippage of the clutch and, in addition, the components are more expensive to manufacture than a unidirectional unit. Also, a bidirectional ball ramp will have a reduced rotational travel between the control ring and the drive ring in a given pack size compared to a unidirectional ball ramp mechanism. Thus, a unidirectional ball-ramp mechanism is preferred if it can be made to activate in both operating, driving and inertial running modes of the vehicle. The ball-ramp actuator comprises a plurality of rolling elements, a control ring and an opposing driving ring wherein the driving ring and the control ring define at least three opposite single ramp surfaces formed as semicircular circumferential grooves, containing each pair of opposite slots a rolling element. A thrust bearing is interposed between the control ring and a housing element, which rotates with and is connected to the input element, such as a steering wheel. An electromagnetic coil is disposed adjacent to an element of a control clutch so as to induce a magnetic field to load the control clutch which in turn applies a force to the control ring of the ball-ramp actuator. The control clutch can be similar to those commonly used for vehicle air conditioner compressors, or a cone type clutch to increase the transmitted drive force. SUMMARY OF THE INVENTION The present invention is characterized by a flywheel (input element) driven by a power generator and a transmission input shaft (output element) coupled through a ball-operated clutch. The ball ramp mechanism has a plurality of unidirectional variable depth slots (ramps) and a drive ring having variable depth grooves in a single direction at least partially opposite and of geometry substantially similar to those of the control ring. Examples of clutch systems with ball-ramp actuator are illustrated in U.S. Patents 1,974,390; 2,861,225; 2,937,729; 3,000,479; 5,485,904 and 5,505,285. The drive ring can not turn against when the clutch is locked in the inertial gear mode of the vehicle due to the use of one-way clutches. Two sets of planetary gears (one of which is a partial planetary and functions as a one-way large-diameter clutch) are used to allow the ball-ramp actuator to increase the clamping force on the friction disk of the clutch, both in driving mode and inertia, without reduction in clamping force when going from one mode to the other. Accordingly, using the present invention, the ball-ramp mechanism of the present invention does not pass through a non-activated state when the vehicle goes from driving to inertial mode, as with the prior art devices, and is reduced clutch slip Once the electromagnetic coil is energized, the ball-ramp mechanism can only increase the clamping force independently of the operating condition of the vehicle. The electromagnetic coil is used to activate a control clutch that frictionally couples the control ring through one of the planetary gear sets to the input shaft of the transmission. When energized by the coil, the ball-ramp mechanism provides a clamping force on the friction disk of the clutch, where the amplitude of the clamping force increases immediately whenever there is a rotational speed differential between the flywheel and the shaft. input of the transmission. According to the present invention, the amplitude of the clamping force is maintained at a given level or is increased as the coil is energized by the action of the one-way clutches acting on the individual planet gears in the sets of planetary gears, so that when the vehicle enters an inertial gear mode (where the engine is braking as opposed to driving the vehicle) the ball-ramp actuator remains fully activated. The sliding of the clutch in the driving mode will cause the ball-ramp mechanism to increase the clamping force on the clutch disc. Also, in the inertial gear mode, if for some reason there is slippage of the clutch, the planetary gear sets provide additional relative rotation between the control ring and the drive ring in the proper direction to increase the clamping force on the discs of clutch friction. A provision of the present invention is to prevent a ball-operated clutch from disengaging when the input torque is reversed. Another provision of the present invention is to prevent a ball-actuated clutch having unidirectional ramps from disengaging when the drive line torque is in inertial gear mode by locking the rotary orientation between a control ring and a drive ring using one-way clutches acting on the planet gears of a planetary gear set and a one-way primary clutch between the carrier ring and the flywheel. Another provision of the present invention is to allow a ball-operated drive line clutch that links an input element to an output element having unidirectional ramps to increase its level of linkage when the torque of the drive line is in an inertial gear mode using a planetary gear set and a one-way clutch acting between a carrier ring and the input element. Another provision of the present invention is to allow a drive line clutch driven by a ball-ramp actuator having unidirectional ramps to increase its driving force when the transferred drive line torque reverses the direction using a planetary gear set. wherein each planetary gear is supported on a clutch of a way mounted not rotatably on a support pin attached to a carrier ring. Yet another provision of the present invention is to allow a drive line clutch driven by a ball-ramp actuator having unidirectional ramps to increase its driving force when the transferred drive line torque reverses the direction using a planetary gear set. and a one-way primary clutch where a plurality of one-way clutches prevent reverse rotation of the planet gears relative to the transmission input shaft. Brief Description of the Drawings Figure 1 is a partial section of the drive line clutch assembly of the present invention; Figure 2 is a partial section of the planetary gear set of the present invention taken along the line II-II of Figure 1 with the driving line of the vehicle in driving mode; Figure 3 is a partial section of the planetary gear set of the present invention taken along the line II-II of Figure 1 with the drive line of the vehicle in inertial gear mode; Figure 4 is an axial section of the ball ramp mechanism of the present invention taken along line IV-IV of Figure 1; and Figure 5 is a section of the ball-ramp mechanism of the present invention taken along line V-V of Figure 4 with the ball-ramp mechanism in a non-energized state; and Figure 6 is a section of the ball-ramp mechanism of the present invention taken along the line VV of Figure 4 with the ball-ramp mechanism in energized state. Detailed Description of the Preferred Embodiment Form For the purpose of To promote the understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and a specific language will be used to describe them. However, it should be understood that there is no intent to limit the scope of the invention, contemplating such alterations and subsequent modifications in the illustrated device, and such additional applications of the principles of the invention illustrated herein that would normally occur to one skilled in the art. to which the invention belongs. Some terminology will be used in the following description for convenience and not by way of limitation. For example, the terms "forward" and "backward" will refer to the forward and backward directions of the clutch assembly as it is normally mounted in a vehicle. The terms "rightward" (to the right) and "left ard" (to the left) will refer to addresses in the drawings in connection with which the terminology is used. The terms "inwardly" (inwardly) and "outwardly" (outward) will refer to directions towards and away from, respectively, the geometric center of the apparatus. The terms "upward" and "downward" will refer to the directions in the drawings in connection with which the terminology is used. All the terms mentioned include the derivatives and normal equivalents thereof. With reference to the drawings, which do not limit the present invention, FIG. 1 is an axial section of a master drive line clutch assembly 2 of the type in which the present invention can be used. The clutch assembly 2 includes a flywheel 4 also called an input element having a friction surface 4A rotatably driven by a power generator (not shown) such as an internal combustion engine by its output crankshaft (not shown) which is coupled to a transmission (not shown) by a drive line clutch assembly 2 driven by a ball-ramp mechanism 5. A clutch bell housing 6 surrounds the clutch assembly 2 and supports the transmission including the input shaft 8 of the transmission also called an output member that extends to engage non-rotatably with a first clutch disk 10 having a friction disk 10A and a friction disk 10B through slots 10C at the left end of the input shaft 8 of the transmission from where the input shaft 8 of the transmission is then extended to the right to drive the gears of the transmission. Also, a second clutch disk 11 having a friction disk HA and a friction disk 11B is linked to the input shaft 8 of transmission through slots 11C. The first clutch disc
is clamped between the flywheel 4 and an intermediate pressure plate 13 while the second clutch disk 11 is clamped between the intermediate pressure plate 13A and a primary pressure plate 13B. A drive ring 12 acts on the Bellville washer 18 to apply an axial force on the primary pressure plate 13B against the second clutch disk
11 and the intermediate pressure plate 13A against the first clutch disk 10 against the flywheel 4 on the friction surface of the flywheel 4 A thereby transferring the rotational power from the power generator to the transmission through the input shaft 8 of transmission and eventually to the rest of the vehicle's drive line. In the prior art systems, the clutch pressure plate is forced towards the flywheel using a plurality of loading springs. When the driver wishes to disengage the clutch disc, a mechanical release mechanism is activated by the driver's foot and leg to counteract the force of the springs thus allowing the clutch disc to slide relative to the steering wheel. However, it should be understood that neither the activation springs nor the mechanical release mechanism are characteristics of the present invention. In accordance with the present invention, a ball-ramp mechanism 5 is used to force the drive ring 12 towards the flywheel 4 which is controlled by the clutch control unit 15 electronically taking the place of an operator during the sequences of transmission changes. The bell housing 6 of the clutch partially encloses the drive line clutch assembly 2 including the ball-ramp mechanism 5 of the present invention. The ball-ramp actuators that react the control ring 14 to ground are well known in the art and have been used to load transmission shift clutches as described in U.S. Patent 5,078,249, and differential clutch packs as it is described in United States Patent 5,092,825 where a ball-ramp control ring is reacted against box earth by a coil or motor with gears. Essentially, the relative rotational movement between the control ring 14 and the driving ring 12 causes one or more rolling elements 20A, 20B and 20C (see Fig. 6), which may be spherical elements or cylindrical rollers, to move along a similar number of opposite ramps 22A, 22B and 22C formed in the control ring 14 and ramps 23A, 23B and 23C formed in the driving ring 12, respectively. The ramps 22A, 22B, 22C, 23A, 23B and 23C have a variable axial depth that is unidirectional. Figures 4-6 illustrate this geometry in more detail and precision, to which reference will be made below. The control ring 14 contains the ramps 22A, 22B and 23C and is rotatably connected by friction to the clutch ring 35 when the coil 30 is energized. The control clutch plate 19 is brought to the pole of the coil 32 when the coil 30 is energized by the clutch control unit 15 through electrical connectors 17. The annular electrical coil 30 encircles the transmission input shaft 8 and is supported by the coil support 31 connected to the clutch bell housing 6 through a support extension 7. The electrical coil 30 is located in the vicinity of the coil pole 32 separated by an air spacing where the coil pole 32 is non-rotatably supported on the transmission input shaft 8 on the splined sleeve 33. The splined sleeve 33 and the coil pole 32 and the sun gear 54 all rotate with the transmission input shaft 8. The electric coil 30 is located to be partially enclosed by the coil pole 32 and separated therefrom by a small air spacing. The coil 30 is mounted to the bell housing of the clutch 6 and therefore remains stationary while the coil pole 32 rotates in accordance with the rotation of the input shaft 8. The coil 30 generates an electromagnetic flow illustrated by the arrows 36 in Figure 1 passing through the pole of coil 32 inside the control clutch plate 19 and again through the coil pole 32 towards the coil 30. This electromagnetic flow creates a force tending to bring the clutch element 19 inside the coil pole 32 thus creating a frictional force through contact of the clutch extension element 29 on the clutch ring 35 creating a resultant torque on the control ring 14 (assuming a rotational speed differential between the flywheel 4 and the transmission input shaft 8) which activates the ball-ramp mechanism 5 through the planetary gear set 21 and a one-way primary clutch 60 which rotates the control ring 14 to a locking direction when the vehicle ass is inertial or driving mode. In other words, when the vehicle is being driven, the planetary gear set 21 is work by the locking action of the secondary one-way clutches 44A, 44B, 44C, 44D and the one-way primary clutch 60 releases the wheels. In the inertial mode, the primary one-way clutch 60 is locked, and the secondary one-way clutches allow the planet gears 42A, 42B, 42C, 42D to rotate. In both driving and inertial modes, the relative rotation in any direction of the flywheel 4 and the transmission input shaft 8 causes the ball-ramp mechanism 5 to activate. The one-way primary clutch 60 operates between the support block 49 and a carrier ring 39. Carrier bolts 48A, 48B, 48C and 48D (see Figure 2) are connected to the carrier ring 39 and support the planet gears 42A, 42B, 42C and 42D through secondary clutches of a via respective 44A, 44B, 44C and 44D. When the clutch discs 10 and 11 are disengaged or begin to slip due to the excessive torque supplied by the power generator (motor) through the flywheel 4, there is a relative rotation between the control ring 14 and the drive ring 12 separating more, in this way, the rings 12 and 14 axially (as described in more detail below) thus increasing the clamping force of the driving ring 12 on the clutch discs 10 and 11 in the friction pads 10A, 10B, HA and 11B between the main pressure plate 13A and the intermediate pressure plate 13A and the flywheel 4. This occurs through a small range of rotary movement of the control ring 14 relative to the drive ring 12 and provides a force adjustment of automatic clamping, virtually instantaneous, should any relative rotation occur between the flywheel 4 and the input shaft of transmission 8. The thrust bearing 56, which can be any type of appropriate bearing, r it acts against the second support block 49B which is connected to the first support block 49A and is used to contain the axial forces generated by the rolling elements of the ball ramp 20A, 20B and 20C as they are connected to the ramps 22A, 22B, 22C, 23A, 23B and 23C in the control ring 14 and the drive ring 12, respectively (see figure 4). The ring gear 40 rotates relative to the support block 49 which is connected to the flywheel 4 through the housing 6. The rotation of the control ring 14 relative to the drive ring 12 causes the drive ring 12 to move axially towards the Steering wheel 4 thereby holding the first and second clutch discs 10 and 11 between the drive ring 12 and the flywheel 4. The drive ring 12 is non-rotatably connected to the housing 6 but can be moved axially relative thereto. The control coupling 24 consists of a conical clutch 28, one side of which is the clutch ring 35 which is connected to rotate with the ring gear 40 of the planetary gear set 21 and the second side is the clutch extension 29. Channels 37 are extended from the clutch extension element 29 which is connected to the control clutch plate 19 which forms the clutch coupling 24. In this manner, the conical clutch 28 couples the control ring 14 to the clutch ring 35. , and consequently to the ring gear 40. It is desirable to adhere friction material to the extension element of the control clutch 29 and / or to the clutch ring 35 in the conical clutch 28 to provide the desired torque transfer between these elements. when the coil 30 is energized. The clutch extension element 29 utilizes the drive flanges 38 extending therefrom to rotationally drive one side of the conical clutch 28 without problems of radial and axial alignment due to the manner in which the drive flanges 38 are linked to the drive channels 37. Without this type of clutch coupling 24, the tapered clutch 28 will tend to adhere due to the production and wear tolerances of the components forming the clutch coupling 24. In accordance with the present invention, once the clutch assembly 2 is locked, the coil pole 32 rotates at the same speed of the flywheel 4 and a minimum parasitic electrical energy is required towards the coil 30 to maintain the clutch assembly lock 2. Using the technique previous, the control ring 14 can be reacted against a ground surface, such as the clutch bell housing 6, although continuous sliding could occur between the control ring 14 resulting in high parasitic energy losses and there will be no automatic activation of the control mechanism. 5 ball ramp when sliding the clutch. As illustrated in the present application, connecting the control ring 14 to the transmission input shaft 8 through the control clutch coupling 24 and the planetary gear set 21 controlled by the action of the secondary clutches of a via 44A, 44B, 44C and 44D acting in conjunction with the one-way primary clutch 60, any relative rotation between the flywheel 4 and the transmission input shaft 8 due to slippage of the clutch will further energize the ball-ramp mechanism ^^ 5 thus minimizing clutch slip Also, the reaction time to uniform the minimum slip of the clutch discs 10 and 11 when the vehicle is in running or inertial gear mode using the present invention, is virtually instantaneous since the sliding of the discs of clutch 10 and 11 results in the relative movement between the drive ring 12, the control ring 14 through the friction-locked clutch coupling 24 and the planetary gear set 21 on the side of the control ring 14 and through the pressure plate housing 16 to drive ring 12. Drive ring 12 is rotatably coupled to the housing of clutch pressure plate 16 which in turn is connected to flywheel 4, all rotating in unison. ^ The push spring 26 operating between the flange 26A
P and housing 26B pre-load the armature to minimize the effect of air spacing when the coil is first
de-energized and functions to eliminate unpredictable engagement of the control coupling 24. If the control coupling 24 is not pre-charged, the coil 30 could require a higher current level to pull the control clutch plate 19 inward resulting in a greater force in the conical clutch 28 than desired after the control clutch plate 19 passes through the air spacing. Any type of device can be applied to apply a preload force on the control clutch plate 19 or the clutch extension 29 which has the effect of preloading the clutch coupling 24 towards the activation state. A plurality of pressure plate springs 50 act to urge the ball ramp mechanism 5 including the drive ring 12 outwardly from the clutch friction discs 10 and 11 and the flywheel 4 acting as spring elements between the housing pressure plate 16 and drive ring 12 accordingly pushing the drive ring 12 out of the flywheel 4. The pressure plate housing 16 is connected to the flywheel 4 so that the driving ring 12 rotates with the flywheel 4 but it can move axially relative to the flywheel 4 as controlled by the action of the ball-ramp mechanism 5 which acts to compress the
• pressure plate springs 50. Reference will now be made to figures 1, 2 and 3 where figures 2 and 3 are seen in partial section of the set of 20 planetary gears 21 of the present invention taken along line II -II of Figure 1 with the vehicle in driving mode and inertial mode, respectively. Figure 2 illustrates the direction of rotation of sun gear 54 for purposes of this illustration, as in the clockwise direction with arrow A and circular crown 40 as clockwise by arrow B and secondary clutches of a via 44A 44B, 44C and 44D with the arrows marked C and the direction of the carrier ring 29 with arrow D representing the rotation when the drive line is in driving mode. The carrier ring 39 with the carrier bolts 48A, 48B, 48C and 48D can not rotate counter-clockwise relative to the flywheel 4 by the action of the one-way primary clutch 60. Figure 3 illustrates the direction of rotation of the sun gear 54 and the circular crown 40 and the reverse rotation direction of the carrier ring 39 relative to the flywheel 4 where the sliding of the line clutch causes the ball-ramp mechanism 5 to be activated identical to the activation in the driving mode. The planetary gear set 21 is arranged to rotate the control ring 14 in one direction to further activate the ball ramp mechanism 5 regardless of whether the vehicle is operating in conduction or inertial mode. The planetary gear set 21 is constituted by a plurality of planet gears 42A, 42B, 42C and 42D supported on respective secondary clutches of a way 44A, 44B, 44C and 44D, each of which are not rotatably supported on respective carrier bolts. 48A, 48B, 48C and 48D. Note that with the planetary gear set 21 any number of planet gears and associated support bolts can be used. The planet gears 42A, 42B, 42C and 42D then mesh with the ring gear 40 which is rotatably supported by the support block 49 rotating with the flywheel 4. The ring gear 40 is connected to the clutch ring 35 and rotates with the same. The planet gears 42A, 42B, 42C and 42D are held in axial position by the carrier ring 39 which is connected to the one-way primary clutch 60 all rotating around the rotation axis 47. The one-way primary clutch 60 prevents the carrier ring 39 of the planetary gear set 21 rotates in a direction that, when operating together with the secondary clutches of a track 44A, 44B, 44C and 44D, result in a deactivation of the ball-ramp mechanism. When the coil 30 is energized, the planetary gear set 21 operating in conjunction with the primary one-way clutch 60 provides relative rotation of the control ring 14 and the drive ring 12 only in one direction resulting in additional activation of the mechanism. of ball ramp 5 and increases the clamping force on the clutch discs 10 and 11 regardless of the operating mode of the vehicle and the flow of torque through the drive line. The axial forces generated by the ball-ramp mechanism 5 are transmitted by the thrust bearing 56 within the second block 49B which is connected to the flywheel 4 through the pressure plate housing 16. In the opposite direction, the force generated by the ball-ramp mechanism 5 is transmitted to the clutch discs 10 and 11 and to the flywheel 4. It should be noted that any number of clutch discs can be used including only one clutch disc without the intermediate pressure plate 13A. In Figure 2, the arrow S indicates the relative rotation direction of the sun gear 54, the arrow A indicates the relative rotation direction of the ring gear 40, the arrow P indicates the relative direction rotation of the planet gears 42A, 42B , 42C, 42D, the arrow C indicates the relative direction of rotation of the carrier ring 30. The annulus 40 is non-rotatably connected to the support block 49. The friction surface of the conical clutch 28 frictionally engages the clutch ring 35 with the control ring 14 through the clutch extension element 29 when the coil 30 is energized. The planet gears 42A, 42B, 42C and 42D are rotatably supported by respective support bolts 48A, 48B, 48C and 48D that are connected to the carrier ring 39. The planetary gear set 21 has a sun gear 54 illustrated by rotating counterclockwise driven by the motor and as the planet gears 42A, 42B, 42C and 42D are locked, the ring gear 40 rotates with the sun gear 54. Thus, any sliding of the friction discs 10A, 10B results in a further activation of the gear mechanism. ball ramp 11 so as to increase the clamping load on the friction discs 10A and 10B. Figure 3 is a partial sectional view of the clutch assembly 2 of Figure 1 taken along the line II-II illustrating the relative rotation of the planetary gear set 21 when the vehicle is in the inertial mode. The carrier ring 39 and the carrier bolts 48A, 48B, 48C and 48D are rotating with the flywheel of the motor 4 since the secondary clutches of a track 44A, 44B, 44C and 44D are locked and prevent the planet gears 42A, 42B, 42C and 42D turn counterclockwise. The ball-ramp mechanism 11 is thus further energized when sliding occurs between the flywheel 4 and the friction disk 10A and 10B identical to that produced as the result illustrated in Figure 2. Referring now to Figures 4, 5 and 6 to describe the operation of the ball-ramp mechanism 5, a cut-away view of the ball-ramp mechanism 5 and views taken along line IV-IV of the drive ring 12 and the rim control 14 separated by a spherical element 20A are illustrated in figures 5 and 6. Three spherical rolling elements 20A, 20B and 20C are spaced approximately 120E by rolling on three ramps 22A, 22B and 22C having a variable axial depth, respectively, as customized that the control ring 14 rotates relative to the drive ring 12. Any number of spherical rolling elements 20A, 20B and 20C and respective ramps 22A, 22B, 22C, 23A, 23B and 23C can be used, depending on the desired rotation and axial movement of the ball ramp mechanism 5. It is mandatory to use at least three spherical rolling elements 20A, 20B and 20C passing over a similar number of identical opposite ramps equally spaced 22A, 22B, 22C, 23A, 23B and 23C formed respectively on the control ring 14 and the drive ring 12 to provide axial and radial stability to the ring of control 14 and drive ring 12. As mentioned previously, any type of rolling elements such as a ball or a cylindrical roller can be used. The drive ring 12 is illustrated, which rotates with the flywheel 4, the pressure plate housing 16 and the first and second blocks 49A, 49B by rotating about the rotation axis 47 which coincides with the axis of rotation of the shaft Transmission input 8. Three semicircular, circumferential ramps 23A, 23B and 23C formed on the face of the drive ring 12 are illustrated with corresponding identical opposing ramps 22A, 22B and 22C formed on the face of the control ring 14. The ring of control 14 and drive ring 12 are made of high strength steel and unidirectional tapered ramps 22A, 22B, 22C, 23A, 23B and 23C are carbureted and hardened to Rc 55-60. The ramps 22A, 22B, 22C, 23A, 23B and 23C are tapered in depth as illustrated more clearly in Figure 4 at about 120E (actually less than 120E to allow a separation section between the ramps). The separation 66 between the control ring 14 and the driving ring 12 is determined by the rotational orientation between the two corresponding opposite ramps such as 22A and 23A, where the spherical rolling member 20A rolls on both ramps 22A and 23A as the The control ring 14 rotates relative to the drive ring 12 on the same axis of rotation. In substantially identical manner, the rolling element 20B rotates on both ramps 22B and 23B and the rolling element 20C rolls on both ramps 22C and 23C. Relative rotational forces separate the two rings 14, 12 axially or allow them to approach as determined by the position of the rolling elements 20A, 20B and 20C or their respective ramp pairs 22A, 23A and 22B, 23B and 22C, 23C thus providing an axial movement for holding and releasing the clutch disc 10 between the drive ring 12 and the flywheel 4. Figure 5 illustrates the rotational orientation of the control ring 14 and the drive ring 12 when the carrier ring 48 is in a minimum when the ramps 22A and 23A are at one end in alignment and the spherical element 20A is in the deepest section of the ramps 22A and 23A. Assuming that there is a rotational speed difference between the flywheel 4 and the transmission input shaft 8, when the coil 30 is energized, the control ring 14 is rotated relative to the drive ring 12 by means of the application of a rotary torque input. through the clutch coupling 24 and the ramps 22A and 23A move relative to one another causing the spherical member 20A to roll over each of the ramp surfaces 22A and 23A moving to a different position on both ramps 22A and 23A separating so to the control ring 14 and the drive ring 12 at a wider spacing 66 as illustrated in FIG. 5. A similar separation force is generated by the rolling element 20B which rolls on the ramp surfaces 22B and 23B and by the rolling element 20C rolling on ramp surfaces 22C and 23C. The rotation of the control ring 14 is clearly illustrated with reference to Figures 4 and 5 by the relative position shift of the reference points 62 and 64 from directly opposite in Figure 4 to a deviated position in Figure 5 caused by the rotation of the control ring 14 in the direction of the arrow 70. This increase in axial displacement can be used for a variety of applications, and especially drive line clutches, since the level of force relative to the torque applied to the ring of control 14 is rather high, typically a ratio of 100: 1. This can be used as illustrated in this application to load a drive spring 12 against the clutch discs 10 and 11 and the flywheel 4 in a drive line of a vehicle. Additional operation details illustrative of the operation of a ball-ramp actuator can be found in the United States patent 4, 805.486. If the flywheel 4 is rotating at the same speed as the transmission input shaft 8, even if the coil 30 is energized, the control ring 14 rotates at the same speed as the driving ring 12 and no additional axial force is generated by part of the ball-ramp mechanism 5 since there is no relative rotation between the control ring 14 and the drive ring 12. Assuming that the coil 30 remains energized thereby electromagnetically linking the control ring 14 to the transmission input shaft 8 through the clutch coupling 24, the coil pole 32 and the first and second planetary gear sets 21A and 21B, according to the present invention, any relative rotation between the flywheel 4 and the transmission input shaft 8, results in a relative rotation between the ring of
^^ control 14 and the drive ring 12 in a direction which causes the spherical elements 20A, 20B and 20C to further increase the spacing 66 between the control ring 14 and the drive ring 12, thereby generating outside clamping by part of the drive ring 12 so as to use the power of the flywheel to increase the locking force on the clutch disk 10. In accordance with the present invention, the vehicle drive line clutch actuator can be used for coupling a rotary input shaft to an output shaft where the
The input shaft would be analogous to the flywheel 4 and the output shaft would be analogous to the transmission input shaft 8, as illustrated in FIG. 1. The present invention will prevent the ball-ramp mechanism 5 from retracting and disengaging the discs. of clutch 10 and 11 as the coil 30 is energized 25 thereby providing a frictional engagement between the input shaft (flywheel) and the output shaft (transmission input shaft) regardless of the direction of torque transfer . The invention has been described in greater detail, sufficient to allow one skilled in the art to manufacture and use it. Various alterations and modifications of the invention will occur to those skilled in the art based on reading and understanding the foregoing memory, and it is intended to include all alterations and modifications as part of the invention, insofar as they are within of the scope of the appended claims.