MXPA99010199A - Serpentine drive system with improved over-running alternator decoupler - Google Patents

Abstract

Se describe un sistema@de impulsión (impulsor o de propulsión) de banda en serpentín (18) para un vehículo automotriz que comprende un montaje o conjunto de impulsión o impulsor (o de propulsión)que incluye un motor (10) de combustión interna que tiene unárbol de salida (14) con una polea impulsara (16) sobre el mismo giratoria alrededor de un eje de la polea impulsara. Una secuencia de montajes impulsados tienen cada uno una polea impulsada giratoria alrededor de un eje paralelo con el eje de la polea impulsara y una banda en serpentín (20) montada en relación cooperante con la polea impulsara (16) y con las poleas impulsadas en una secuencia que corresponde con la secuencia de los montajes impulsados cuando se relacionan con la dirección de movimiento de la banda, para provocar que las poleas impulsadas giren en respuesta a la rotación de la polea impulsada. La secuencia de montajes impulsados incluyen un montaje de alternador (26) que incluye unárbol (36) del alternador, montado para su rotación alrededor de un eje delárbol. Una estructura de cubo (52) es portada fijamente mediante elárbol (36) del alternador para su rotación con el mismo alrededor del eje delárbol. Un mecanismo de muelle y embrague unidireccional acopla la polea (26) del alternador con la estructura de cubo. El mecanismo (72) de muelle y embrague unidireccional comprende un elemento de muelle resiliente (74) formado separadamente y unido en serie con un elemento de embrague=direccional (76). El elemento de muelle resiliente (74) es construido y arreglado para transmitir los movimientos rotacionales impulsados de la polea (26) del alternador mediante la banda en serpentín (20) a la estructura de cubo (52), de tal manera que elárbol (36) del alternador es girado en la misma dirección como la polea (26) del alternador, en tanto que tiene capacidad de movimientos resilientes relativos instantáneos en direcciones opuestas con respecto a la polea del alternador durante el movimiento rotacional de la misma. El elemento de embrague unidireccional (76) es construido y, arreglado para permitir que la estructura de cubo y de aquíelárbol del alternador giren a una velocidad mayor que la velocidad rotacional de la polea del alternador, cuando la velocidad delárbol de salida del alternador es desacelerada a una extensión suficiente para establecer el momento de torsión entre la polea (26) del alternador y, la estructura de cubo (52) al nivel negativo predeterminado.

Description

BLOWER DRIVE SYSTEM WITH IMPROVED DECOUPLER OF SPIN ALTERNATOR AT GREATER SPEED Field of the Invention This invention is concerned with the driving or propulsion systems and more particularly with coil accessory drive systems for automotive vehicles.

BACKGROUND OF THE INVENTION These systems are in common use to transfer power or energy from a crankshaft of the internal combustion engine to accessory components that commonly include an alternator (generator), water pumps, oil pump (hydraulic steering), air conditioning compressor (via electromechanical clutch). These components are usually mounted in a fixed position and use an automatic band tensioner to provide a constant band tension and band gap absorption. Internal combustion engines generate rotary power in the crankshaft only when a combustion event occurs. This is in effect a pulsed system whereby the closer the spacing of the combustion events, the more uniform is the rotational consistency of the motor. For each combustion stroke, the REF: 32024 crankshaft will exhibit acceleration, then deceleration, until the next combustion stroke. In general, the slower the engine rotation and the smaller the number of cylinders (combustion events per crankshaft revolution), the greater the magnitude of the pulsating effect. The burning characteristics of the fuel also have a substantial influence for example the instant acceleration of the crankshaft in a diesel engine is much greater than a similar gasoline powered engine due to the combustion process itself. In terms of the serpentine band system, the crankshaft pulses are transferred to the band as fluctuations in speed. Thus, the motor speed fluctuations are transferred to all the components driven in the system. A fluctuation of dynamic band voltage is generated by the fluctuation of speed. Regardless of the dynamic load of the accessory components and the consequent stress effects, it is obvious that the driven inertias will generate dynamic stresses as the band continuously tries to accelerate and decelerate such components. The magnitude of force required is proportional to the inertia and the proportion driven. The function is square. Where the motor is smaller, four or five cylinders and in the lowest speed range (travel area or minimum speed) the dynamic voltage fluctuation is in the highest magnitude. The magnitude can be further increased by the technological differences that serve to decrease the inertia of rotation of the motor (double mass flywheel) or increase the instantaneous acceleration (diesel, higher compression, etc.). .The operating conditions can also have a significant effect, for example "drag" where the engine is operating at a speed lower than its minimum speed (running or minimum or inactive speed) ideal at high power levels trying increase the speed back to inactive. Under these circumstances, the dynamic load of the band can be so great that the band tensioner can not compensate for all dynamic fluctuations. The results may include band noise, band slippage and forced vibration of the band, tensioner and accessory components. Finally, durability is compromised. It is possible to solve this problem by using an insulator or torsional insulator on the crankshaft, provided that it has low rigidity. Such conventional insulators or torsional insulators have been used for many years but are bulky, expensive, heavy and exhibit limited effectiveness. This limited effectiveness is generally the result of the propulsion or drive that has to be designed to carry the full power capacity of the system, while it rarely still requires the same. Thus, the insulators or torsional insulators are normally too rigid. U.S. Patent No. 5,156,573 commonly assigned ("the? 573" patent), incorporated herein by reference, discloses a coil drive system for an automotive vehicle that provides a coil spring and unidirectional clutch mechanism between the pulley of the vehicle. Alternator and mounting cube structure. The described preferred embodiment of the mechanism takes the form of a spring in general helical of spring steel, which performs the double function of: 1) resiliently transmitting rotational movements driven from the alternator pulley to the hub, such that the shaft alternator is rotated in the same direction as the pulley insofar as it has instantaneous relative resilient rotational movement capabilities in opposite directions with respect to the pulley during the driven rotational movement of the pulley and 2) uncoupling the hub alternator pulley from such that the structure of the hub and hence the alternator shaft can rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the motor is decelerated to a sufficient extent to set the torque between the alternator pulley and the cube structure at a predetermined negative level. Each of the two functions indicated above have different design requirements to optimize the system. For example, the resilient coupling function would optimally have a higher spring ratio (a stiffer spring) than the spring rate used to carry out or perform the coupling / uncoupling function. Optimally, a higher spring ratio is desirable for transmitting rotationally driven motion of the alternator pulley to the hub structure, in order to accommodate or compensate for relatively high torsional forces, while a lower spring ratio is desirable for the function of decoupling, in such a way that less force is exerted and thus less frictional wear and heat is generated by the mechanism during uncoupling or runaway condition. Increasing the spring ratio of the mechanism to compensate for the torque transmission function would be detrimental to the coupling / uncoupling function, while decreasing the spring rate to compensate for the coupling / uncoupling function would be detrimental to the function of torsion transmission. As another example, the coupling / decoupling function ideally requires a material having a coefficient of friction greater than that required for the torsion transmission function. It is an object of the present invention to provide an improved serpentine belt drive or drive system that individually optimizes the two functions indicated above. According to this object, the present invention provides a serpentine drive or propulsion system for an automotive vehicle, comprising a drive assembly, which includes an internal combustion engine having an output shaft with a driving pulley on the same revolving around a driving pulley shaft. A sequence of driven assemblies or assemblies each has a driven pulley rotating about an axis parallel to the driving pulley shaft and a serpentine belt mounted in cooperating relationship with the driving pulley and pulleys driven in a sequence corresponding to the sequence of driven mounts when related to the direction of movement of the belt to cause the driven pulleys to rotate in response to the rotation of the driving pulley. The sequence of assembled assemblies or assemblies includes an assembly or alternator assembly that includes a shaft of the alternator mounted for rotation about a shaft of the tree. A cube or center structure is borne steadily by the alternator shaft for rotation with it around the axis of the tree. A unidirectional spring and clutch mechanism couples the alternator pulley to the hub or center structure. The unidirectional spring and clutch mechanism comprises a resilient spring element formed separately from and joined in series with a unidirectional clutch member. The resilient spring element is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the coil band to the cube structure, such that the alternator shaft is rotated in the same direction as the alternator pulley insofar as it has instantaneous relative resilient movement capability in opposite directions with respect to the alternator pulley during the driven rotational movement thereof. The unidirectional clutch element is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the engine is decelerated to a sufficient extension to establish the torque between the alternator pulley and the cube structure at a predetermined negative level. It is a further object of the invention to provide a device that addresses the issues indicated above and that can be used to transmit movement of a driven belt by an output shaft of a motor to a shaft of an auxiliary component to be driven. The device comprises a cube or center structure, a pulley element and a unidirectional spring and clutch mechanism. The cube structure is constructed and arranged to be fixedly fixed by the tree for rotation with it around an axis of the tree. The pulley element is mounted on the cube structure and constructed and arranged to engage with the band and be rotationally driven therethrough. The unidirectional spring and clutch mechanism couples the pulley element with the hub structure. The unidirectional spring and clutch mechanism comprises a resilient spring element formed separately from and joined in series with a unidirectional clutch member. The resilient spring element is constructed and arranged to transmit the driven rotational movements of the pulley element to the cube structure, such that the shaft is rotated in the same direction as the pulley, while being capable of relative resilient movements instantaneous in opposite directions with respect to the pulley during the rotational movement driven thereof. The unidirectional clutch element is constructed and arranged to allow the cube or center structure and hence the tree to rotate at a speed greater than the rotational speed of the pulley when the speed of the driven pulley is decelerated to a predetermined extent. It is a further object of the present invention to provide a serpentine belt drive or propulsion system in which the spring ratios discussed above are used. According to this object, the present invention provides a serpentine belt drive system for an automotive vehicle comprising a drive assembly that includes an internal combustion engine, having an output shaft with a rotating drive pulley thereon. about a driving pulley shaft, a sequence of driven assemblies or assemblies each having a driven pulley rotating about an axis parallel to the driving pulley shaft and a serpentine belt mounted in cooperating relationship with the driving pulley and with the driving pulley. pulleys driven in a sequence corresponding to the sequence of the mounts or sets driven when they are related to the direction of movement of the belt, to cause the driven pulleys to rotate in response to the rotation of the driving pulley. The sequence of driven assemblies includes an assembly or alternator assembly that includes an alternator shaft mounted for rotation about a shaft axis. A cube or center structure is borne steadily by the alternator shaft for rotation with it around the axis of the tree. A unidirectional spring and clutch mechanism couples the alternator pulley to the hub structure. The unidirectional spring and clutch mechanism comprises a resilient spring portion arranged in series with a unidirectional clutch portion, the resilient spring portion has a ratio of torsional spring at least ten times greater than the ratio of torsional spring of the unidirectional clutch portion. The resilient spring portion is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the serpentine belt to the hub structure, such that the alternator shaft is rotated in the same direction as the alternator pulley in that it has the capacity of instantaneous relative resilient movements in opposite directions with respect to the alternator pulley during the rotational movement driven thereof. The unidirectional clutch portion is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the engine is decelerated to a sufficient extension to establish the torque between the alternator pulley and the cube structure at a predetermined negative level. Another object of the invention is to provide a unidirectional spring and clutch mechanism having a clutch portion as a coefficient of friction greater than the spring portion. Another object of the present invention is to provide a unidirectional spring and clutch mechanism in which the clutch portion expands radially outward and is thus aided by centrifugal force when coupled with the alternator pulley to be engaged. The invention is based on the fact that the effective inertia of the alternator is by far the largest in the typical accessory drive system, but uses only a portion of the power requirement for the system. If the apparent inertia can be reduced, the dynamic voltage fluctuation can also be greatly reduced. By providing an effective decoupling function between the alternator pulse and the rotor (armature) of the alternator, the apparent inertia can be significantly reduced. It is important to note that the resilience or elasticity of the decoupler must be sufficiently soft in such a way that the amplification of the pulley speed fluctuation can not be transmitted to the rotor in the normal operating speed range of the engine where a control of the maximum dynamic tension. The present invention provides a unidirectional torque-sensitive clutch connected in series with a separate decoupling elastic or resilient member. It will be demonstrated that the unidirectional clutch provides additional value for solving other problems, while performing or carrying out its primary function of maximizing the durability of the resilient or elastic decoupler. At operating speeds greater than the minimum speed, a sudden deceleration of the belt can impose large stress reversals on the belt as it attempts to brake the rotor mass. These decelerations commonly occur in transmission gear shifts or "choke bursts" (that is, to accelerate the engine as long as the car is heated). In addition to cumulative band fatigue damage, screeching noise is often present, especially if the tensioner is forced against its fixed stop due to the reversal of tension. Due to the torque-sensitive nature of the clutch according to the present invention, as soon as the torque load is shifted to zero, the clutch will release the coupling between the pulley and the rotor. The alternator rotor will be free to decelerate independently of the belt under a torque of drag or braking applied. The band will only give a very small voltage inversion, the equivalent of the breaking torque. This feature will eliminate the sensitivity to deceleration in such systems. Other objects and advantages of the present invention will be appreciated from the following detailed description, the drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevational view of an automotive internal combustion engine having a serpentine drive system comprising the principles of the present invention bonded thereto; Figure 2 is an enlarged fragmentary sectional view taken along line 2-2 of Figure 1 and Figure 3A is a sectional view taken along line 3A-3A of Figure 2; Figure 3B is a fragmentary view enlarged partially in section showing the connection between the spring and unidirectional clutch members of the resilient decoupler of the present invention; Figure 4 is a perspective view of the unidirectional spring and clutch mechanism of the decoupling, resilient, according to the present invention; Figure 5 is a side plan view showing an alternative configuration for the unidirectional wrapped clutch spring mechanism of the present invention; . Fig. 6 is a schematic view showing the parallel damping effects that are obtained when the bushing and the unidirectional wrapped spring / clutch element / serial torsional coil spring of the present invention; Figure 7 is a cross-sectional view of an alternative embodiment of the decoupler and alternator according to the present invention; Fig. 8A is a cross-sectional view of a third embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 8B is a front plan view of the alternator decoupler shown in Figure 8A, with certain portions removed to better reveal other portions; Figure 9A is a cross-sectional view of a fourth embodiment of a runaway alternator uncoupler in accordance with the principles of the present invention; Figure 9B is a front plan view of the alternator decoupler shown in Figure 9A, with certain portions removed to better reveal others; Fig. 10A is a cross-sectional view of a fifth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 10B is a front plan view of the alternator decoupler shown in Figure 10A, with certain portions removed to better reveal others; Figure HA is a cross-sectional view of a sixth embodiment of a break-away alternator uncoupler according to the principles of the present invention; Figure 11B is a front plan view of the alternator decoupler shown in Figure HA, with certain portions removed to better reveal others; Figure 12A is a cross-sectional view of a seventh embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 12B is a front plan view of the alternator decoupler shown in Figure 12A, with certain portions removed to better reveal others; Figure 13A is a cross-sectional view of an eighth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 13B is a front plan view of the alternator decoupler shown in Figure 13A, with certain portions removed to better reveal others; Fig. 14 is a cross-sectional view of a ninth embodiment of a runaway alternator uncoupler according to the principles of the present invention; 1_ Fig. 15 is a cross-sectional view of a tenth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Fig. 16 is a cross-sectional view of an eleventh embodiment of a runaway alternator uncoupler according to the principles of the present invention; Fig. 17 is a cross-sectional view of a twelfth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Fig. 18A is a cross-sectional view of a thirteenth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 18B is an enlarged cross-sectional view. of the assembly or assembly of ball bearings and the sleeve element of the alternator decoupler shown in Figure 18A; Figure 19 is a perspective view of a clutch assembly used in accordance with the principles of the present invention; Figure 20 is a perspective view of the clutch assembly shown in Figure 19, with the clutch element in an unwound or unmounted configuration; Fig. 21 is an enlarged partial perspective view of the clutch assembly of Fig. 19, illustrating the interface portions in a disassembled condition; Fig. 22 is a cross-sectional view of a fourteenth embodiment of a runaway alternator uncoupler according to the principles of the present invention; Figure 23 is an exploded perspective view of the alternator decoupler illustrated in Figure 22 according to the fourteenth embodiment of the present invention; Figure 24 is a plan view of the trailing end of a structure connecting the carrier used in the fourteenth embodiment illustrated in Figures 22 and 23; Figure 25 is an exploded view of a fifteenth embodiment of a break-away alternator uncoupler according to the principles of the present invention; Figure 26 is a plan view of the trailing end of a carrier connection structure used in the fifteenth embodiment illustrated in Figure 25.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now more particularly to the drawings, there is shown in Figure 1 an automotive internal combustion engine, in general with the number 10, which includes a frame or frame 12 indicated schematically and an output shaft 14 . Fixed to the output shaft 14 is a drive pulley 16 which is part of a coil drive system, indicated generally with the number 18. The drive system 18 includes a worm 20. The belt 20 is of the flexible thin type, such such as a poly-V band. The band 20 is drawn around the pulley ipvpulsora 16 and a sequence of sets or assemblies of pulleys 22, 24, 26, 28 and 30, each of which is fixed to a respective shaft 32, 34, 36, 38 and 40. Except for the pulley assembly or assembly 22, which consists of a idler pulley or guide pulley (or idle pulley), the shafts are connected to operate various engine or vehicle accessories. For example, the shaft 34 drives an engine water pump, the shaft 36 an electric alternator, the shaft 38 an electromagnetic clutch of a compressor for an air conditioning system for the automobile and the shaft 40 an oil pump of the system of hydraulic steering. It will be understood that the internal combustion engine 10 can be of any known construction. According to conventional practice, the operation of the motor is in such a way as to impart vibration forces to the frame or frame 12 of the motor. All the accessories are mounted on the frame or frame 12 of the motor, in such a way that the shafts are rotated around parallel axes which are fixed with respect to the frame or frame 12 of the motor and parallel with the output shaft 14 thereof. . The band 20 is tensioned by a band tensioner, indicated, in general with the number 42 which can be of any construction. However, a preferred embodiment is the tensioner described in commonly assigned U.S. Patent No. 4,473,362, the disclosure of which is incorporated by reference in the present specification. As shown, the belt tensioner 42 includes a idler pulley or guide pulley 44 which is arranged in rolling engagement with the flat rear surface of the belt 20, the tensioner pulley is spring driven to maintain a generally constant tension in the band 20.. The present invention relates more particularly to the assembly or assembly of the pulley, indicated in general with the number 26 and which constitutes a set or assembly of the decoupler of the alternator, which is mounted on the shaft 36 of an alternator. As best shown in Figure 2, the alternator includes a box 46, within which the frame assembly, indicated generally with the number 48, is driven, such as by a ball bearing element 50. As shown, the alternator shaft 36 forms part of the armature assembly 48 and includes an end portion extending outwardly from the alternator case 46. Fixed to the end extending outwardly of the electric alternator shaft 36 is a hub or center structure, indicated generally with the number 52. As shown, the hub structure 52 includes an inner sleeve 54 that extends over the hub. end of the end portion of the shaft 36 of the electric alternator. As shown, the end of the shaft 36 is threaded as indicated at 56 and the sleeve 54 is formed with a series of internal threads 58, which are disposed in abutting relationship with the threads lying on the end of the shaft 36. The inner sleeve 54 includes an annular end surface 60 that is formed to provide a hexagonal socket 62 for the purpose of receiving a tool for securing the sleeve 54 on the shaft 36 by relative rotation between the sleeve 54 and the shaft 36. An element of thrust 63 is fitted on an annular rim and end of the hub 52 opposite the surface 60. The thrust member 63 includes an axially extending cylindrical outer sleeve portion 64 and a flange portion 66 extending radially inwardly., which extends radially inward from an axial end of the outer sleeve portion 64 closest to the alternator. As shown in Fig. 2, the flange portion 66 extending radially inward engages the inner race of the ball bearing element 50 on the shaft 36 of the electric alternator. When the inner sleeve 54 is tightened on the end of the shaft 36, the tightening action serves to firmly mount the inner race of the ball bearing 50 against a flange 70 on the shaft 36 and to securely fix the hub structure 52 thereto. , which includes the inner sleeve 54 and the outer sleeve 64. In accordance with the principles of the present invention, the alternator uncoupler or pulley assembly 20 has a pulley element 106 that engages the belt (which will be described later in greater detail) operably linked to the hub structure 52 by a resilient element and a unidirectional clutch mechanism, joined together as generally indicated by the number 72. The mechanism 72 is preferably in the form of a combination of a coil in general helical or torsion spring 74 made of spring steel and a wrapped spring clutch member 76 attached to spring 74 in a connection 78 of the extr emo, common. The helical steel coil 74 for springs includes a first plurality of volutes 80 towards one end thereof, a scroll portion 82 flat towards the opposite end thereof and a series of intermediate volutes 86 extending therebetween. The first plurality of volutes 80 are snapped to a non-slip fastening coupling with an outer surface 104 of the inner sleeve 54. An arcuate end surface of the first plurality of volutes 80 facing in one direction axial to the alternator engages an annular inner surface 87 of the flange portion 66.

As shown, the arcuate end surface of the first plurality of volutes 80 includes a flat surface portion 91 cut into the first volute to provide a greater surface engagement area between the first volute and the surface 87 of the flange portion 66. The intermediate volutes 86 are larger in diameter than the first plurality of volutes 80 and are preferably free from coupling with another structure to provide a resilient decoupling function as will be described hereinafter in greater detail. The wrapped clutch spring member 76 preferably comprises a spring steel strip 88 spirally formed with a rubber friction improving material 90, preferably a rubber or rubber-based material T-701 manufactured by Thermoset Inc., adhesively bonded to the radially outer surface thereof. As can be appreciated more fully from Figures 3A, 3B and 4, in general between the connection 78 between the wrapped clutch spring member 76 and the torsional coil spring member 74, the steel strip 88 extends beyond the material 90. of friction and has a portion 96 of expanded width which is crimped in surrounding relation, of fixed shape with respect to the end of the spring 74 as shown. The crimped portion 96 preferably has a diameter that tapers or becomes smaller as it approaches the friction material 90, such as the end portion received from the spring 74 to form a tapered fastener. As can also be seen from figure 4, in the connection 78 between the clutch element 76 and the spring 74, the direction of the clutch coils reverses the direction of the spring coils in such a way that the clutch and the spring are generally superimposed axially with respect to the axis of the shaft 36. As can also be seen from FIGS. 3A and 3B, a plastic spacer segment 100 is joined by snap fitting the radially outer surface of the expanded width portion 96 of the web. 88 of steel under a pair of projections 101 that form an interference fit in respective holes in the expanded width portion 96. The plastic spacer segment 100 has a portion 102 of expanded thickness extending in superposed relation with the enlarged and crimped width portion 96 of the steel strip 88 toward the end portion of the connection 78, where the band 88 terminates. of steel and the coil spring 74. The expanded thickness portion 102 is sandwiched in surface contact with the outer surface of the expanded width portion 96 and a cylindrical inner surface 110 of the pulley element 106 of the alternator or pulley assembly coupling 26 The plastic separator 100 also has a portion 103 of reduced graduated thickness, formed integrally with the portion 102 of expanded thickness and extending to the adjacent end of the friction material 90. The portion 103 of reduced thickness leaves a space G between its radially outer surface and the inner cylindrical surface 110 of the pulley element 106. The space G extends circumferentially between the end of the friction material 90 and the expanded thickness portion 102 of the spacer 100. The spring 74 and the clutch 76 are preferably steel elements for high voltage spring and the connection 78 between the two It is particularly advantageous in performance since it allows the transmission of the required loads in both directions. An intermediate connecting element between the spring 74 and the clutch 76 is also contemplated by the present invention to obtain additional decoupling attributes, although this adds cost and weight. Although welding is possible with extensive treatment, it is not economically practical and thus is not preferred. The crimped portion 96 is ^ forcefully adjusted under pressure by a similar relative rotation in principle to a fixation taper. The strength of the connection 78 is further improved by an improved crimping in the portion 89 behind the flat portion 82 of the spring 74 (see Figure 4). The flat portion 82 of the spring 74 is flat on opposite sides of the spring and provides that portion of the spring with a reduced diameter in the radial direction and an enlarged diameter in the axial direction (relative to the shaft axis). The enlarged diameter cross section in portion 82 improves the strength of the tapered connection to result in a connection that is strong and robust and resistant to friction corrosion failure. The connection 78 provides a simple and inexpensive method for joining the two elements (spring and clutch). Due to the resilient element, for example the coil spring 74 is formed separately from and attached to the unidirectional clutch * 76 by means of a connection designed and effective in cost, flexibly in the choice of structure and materials for the resilient element and clutch can be obtained (for example materials dissimilar can be used for the unidirectional clutch and the resilient element). With reference to Figure 5, it can be appreciated that the clutch coil diameters can be varied slightly compared to the clutch coil configuration shown in the embodiment of Figure 2 to provide a step effect by which the distance Angular coupling can be varied from almost zero to say 45 °. This feature proves very useful to prevent undesirable uncoupling at low torque loads. Referring again to Figure 2, it can be seen that an annular nylon thrust washer 98 is disposed between an annular edge of the outer thrust sleeve 64 and the edge surface 93 of a free end 92 of the spring element 76 - Clutch wrapped. It should be noted that the free end 92 of the clutch 76 has a radius slightly larger than the other clutch coils to be slightly loaded to a surface engagement with the inner surface 110 of the pulley element 106. As shown in Figure 2, the annular pulley element 106 of the pulley assembly or pulley assembly 26 has an outer poly-V surface 108 for rollingly engaging the operative poly-V side of the serpentine web 20. The inner annular surface 110 is arranged in engagement with an annular sleeve bushes 112, the interior of which is coupled with an outer surface 114 of the outer sleeve 64. More specifically, the bushing 112 is press fit at a fixed ratio to the surface interior 110 of the pulley element 106, while the inner annular surface of the bushings 112 is disposed in sliding friction relation with the outer annular surface of the overlying sleeve 64.

* The outer track of a ball bearing assembly or assembly 118 is press fit to the inner annular surface 110 of the pulley element 106, although other retaining means such as insert rings and detents can be used to hold together the assembly . The ball bearing 118 is also snapped into its inner race on the hub 52. This adjustment arrangement retains the assembly in axial alignment. In general, the inner annular surface 110 of the pulley element 106 will be of a single diameter as illustrated. However, it may be necessary to scale the diameters to accommodate particular design requirements. The inner annular surface 110 of the pulley member 110 also serves as the coupling surface for the unidirectional clutch system, see FIG. 3A and 3B, specifically coupled by brake material 90 (friction) attached to the band of helical steel 88.

OPERATION Referring to Figure 2, the clutch 76 is manufactured with the first free coil 92 having a formed end which essentially serves as a brake shoe. In the "drive or drive" direction the first coil 92 or shoe serves to engage with the pulley surface 110 by friction to thereby sequentially energize all remaining clutch coils. In the direction of "runaway" when the rotational speed of the clutch (which is attached to the frame 48) is greater than the speed of the pulley (the torque is zero to negative) the braking effect is no longer functional and the clutch is released. The remaining forces are the sum of the drag torques for the clutch 76, the pulley element 106, the bearing 118 and the bushing 112. It will be understood that as long as there is a positive torque acting on the element 106 of the pulley by means of the movement of the band 20, the resilient element and the unidirectional clutch mechanism 72 will serve to transmit the movement imparted to the pulley element 106 by the band 20 to the hub structure 52. During this driving movement (cf. arrows of the driving direction in Figure 3B), the free preloaded end 92 of the clutch 76 will frictionally virtually immediately engage and hold the inner annular surface 110 of the pulley member 106. Thus, the initial clamping action is caused in part due to the fact that at least the free end 92 of the clutch 76 has a natural external diameter (relaxed condition) which is somewhat larger than the internal diameter of the cylindrical surface 110. Thus, the first free coil 92 is driven in engagement with the surface 110, with a clamping or gripping action provided by the initial portion of the friction material 90. The gripping or gripping action is further improved by the gradually increasing portions of the clutch 76 which are moved radially outward in engagement with the surface 110 during the initial stages of propulsion or drive movement. Because the clamping force is a function of the number of turns of the coil multiplied by the coefficient of friction, the clamping force of the clutch increases as more of the coils are engaged with the surface 110. Thus it can be seen that -the clutch 66 is "self-energized". It should also be appreciated that the increased centrifugal force applied to the clutch 76 causes the radial expansion of the clutch 76 to an improved clamping coupling with the surface 100. It should also be appreciated that the coefficient of friction between the friction material 90 and the surface 100 of steel is preferably 0.25 or greater. Further, it is preferred that the clutch 76 and the friction material 90 are therefore provided with between 2-3 coil turns and more preferably 2-1 / 2 turns as shown in Figure 4. During this driving movement or propulsion, the plurality of intermediate volutes 86 that are spaced between the internal 54 and external 64 sleeves of the cube structure 52 allow the cube structure 52 and hence the shaft 36 of the alternator fixed thereto to have resilient rotational movement capability instantaneous relative in opposite directions with respect to the pulley 26 of the alternator during the rotational movement driven thereof. Further, when the rotational speed of the output shaft 14 of the motor is decelerated to a sufficient extent to establish a torque between the pulley element 106 and the hub structure 52 at a predetermined negative level, such as for example 0.576 m- Kg (50 inches-pounds) or less, the clutch coils 76 will be separated from the surface 110 and the friction material of the first coil 92 will engage the outer peripheral surface 104 of the inner sleeve with a sliding action that allows the cube structure 52 and hence the shaft 36 or frame assembly 48 fixed thereto rotate at a speed greater than the rotational speed of the pulley element 106. More particularly, as the torsional moment acting by means of the helical torsion spring 74 drops to zero, the forces acting on the unidirectional clutch are similarly relaxed. In the immediate vicinity of the zero torsion moment, the conditions that originally engaged the clutch (bolt shoe 92) become unfavorable to energize the clutch assembly to result in a slip between the clutch 76 and the pulley surface 110. In this condition, the speed of the armature or rotor 48 of the alternator will be greater than the speed of the pulley element 106. The rotation of the clutch 76 and the pulley 106 will be synchronized with the rotor 48. The residual torque is the maximum torque-torque or negative torque that the pulley 106 will experience and thus impart to the 20-band. drag torque is the sum of the coefficient of friction between the clutch friction material 90 with the pulley surface 110, the drag of the ball bearing 118 and the drag between the ferrules 112 and the outer sleeve 64. All these factors are controllable by design to several extensions. In particular, these residual torques can be used to limit excessive runaway speed differentials between the pulley element 106 and the armature 48 that can create excessive noise and heat. In addition, the residual torsional moment provides damping that modifies the control performance of the vibration, that is, modifies the forces in resonance, etc. Figure 6 is a schematic representation of how damping D works in parallel with the entire clutch assembly / assembly 72 / resilient element.

The damping D, indicated above, results mainly from the sliding frictional drag between the inner surface of the bushes 112 and the outer surface of the sleeve portion 64, however, it should be appreciated that an alternative configuration contemplates that the bushing 112 can be adjusted to pressure fixedly to the handle portion 64 and that the cylindrical outer surface of the sleeve 112 may be in sliding friction engagement with the inner surface of the pulley 106 to provide cushioning. It should also be noted that while the ball bearing assembly or assembly 118 also provides some degree of cushioning, it only provides a small fraction of the cushioning provided by the bushing 112. It is important to note that, in terms of function and durability, The clutch and friction drag factors should be varied in such a way that the runaway occurs only under two conditions with a normally operating loaded coil band system. First, when the engine is turned on and the system is in resonance, the clutch allows a runaway to protect the spring 70 from excessive inverse stresses. Secondly, the clutch also allows the runaway when the engine is decelerated forcefully by a gear change or strong deceleration that creates a negative torque between the rotor and the pulley. * It is also important to note that the stepped design of clutch 76 illustrated in Figure 5 can be used to prevent runaway in the operation of the engine in steady state (idle or idle) where crankshaft 14 has a high rotational speed, for example in a robust diesel engine and when the load of the torque of the alternator is very low. Under this condition, the torsion spring 74 can be almost completely relaxed. Then the clutch 76 is used as a transitional spring of low proportion that prevents the runaway or allows the torque to fully reach zero. This design aspect significantly improves the durability under such conditions. Thus the clutch can be configured in such a way as to be "torque moment detector" for both directions in a given range. The clutch holding force 76 and also its relaxation force is effected by the centrifugal force. In other words, because the friction material 90 is forced radially outwardly into engagement with the surface 110 as a result of the centrifugal force during the torque moment driving condition when the pulley 106 is used to transmit the moment of load torsion of the band of the band 20 to the hub structure 52, which improves the clutch holding action 76. An advantage of the design is that by the arrangement of the coupling surface, the centrifugal force improves the power capacity on acceleration and high speed and provides # braking power increased in the runaway of high speeds. It will be understood that the torque moment level of 0.576 m-Kg (50 inch-pounds) discussed above is exemplary only and that the level of negative torque at which the slippage of the clutch is present is best chosen to conform to the characteristics of a particular system. The system will vary depending on the characteristics of: (1) the engine; that is, if it is a "sporty" engine or a more conservative engine that is controlled by a computer and (2) the tension of the band maintained by the belt tensioner 42 of the system. An exemplary belt tension for the 106.60 cm (2 1/2 inch) alternator pulley 106 of 0.576 m-Kg (50 inch-pounds) external diameter with a 180 ° bend is 32 kg (70 pounds). It should be noted that the configuration of the present invention provides a favorable drag / propulsion ratio. The other words, the drag (which is the amount of frictional torque moment resistance during the runaway) is relatively low such that the amount of wear is reduced. On the other hand, virtually no slippage in the drive direction occurs for virtually any size of torque to be driven. Preferably, for two or more turns of the clutch spool 74, a drive / drive or propulsion ratio greater than 8: 1 is provided. More preferably, with a coefficient of friction of 0.3 or greater between the friction material 90 and the surface 110 and at least two coil turns for the clutch 74, the drive / drive ratio is greater than 40: 1. As shown in Figure 1, it is desirable that the belt tensioner 42 operate on the belt 20 in the belt run leading to the alternator uncoupler or pulley assembly or assembly 26. This allows the ability of the tensioner guide pulley 44 to move as the belt run is stressed, due to a change from torque to negative in the drive pulley 16 to compensate at some extent for the moment change. of twist between the band 20 and the pulley assembly 26 or high initial alternator uncoupler. In addition, the resilience of the intermediate volutes 86 of the spring 74 provides additional compensation. It will be understood that the resilient characteristics of the resilient element and unidirectional clutch mechanism 72 are adjusted to the particular drive system and more particularly to the particular characteristics of the drive system motor. The strength or strength of the spring 74 is determined by the diameter dimension of the steel wire used to form the coil. An appropriate adjustment is determined by the proportion of the spring that is a function of the extension of the intermediate volutes 86 or the number of turns or volutes included therein. Desirably, the predetermined negative torque moment level at which the clutch slippage occurs is a final backup compensation for the torque to negative torque variation that will prevent slippage of the belt with respect to the alternator or assembly decoupler 26 of pulley with an undesirable concurrent noise. It should be understood that the predetermined torque level at which the slippage of the clutch occurs is chosen by selecting the difference between the relaxed outer diameter of the first plurality of clutch coils (starting at the free end 92) and the inner diameter of the cylindrical peripheral surfaces 110. The ratio is such that the diameter of the surface 110 is smaller than the outer diameter of the end clutch coil such that the end clutch coils (particularly the portion 92). at the end) are subjected to stress during assembly. As the difference in diameter is increased, the predetermined negative torque level is increased in a negative direction. Preferably, the predetermined negative level is chosen in such a way that the slippage of the clutch is minimized insofar as it is secured against slippage of the belt-pulley. Referring now to Figure 7, a pulley assembly or assembly 226 is shown according to a second embodiment of the present invention. The alternator decoupler or pulley assembly 226 works in conjunction with the motor 10 and drive system 18 of FIG. 1 and simply replaces the pulley assembly 26 of that figure. The embodiment shown in Figure 7 works substantially in the same manner as the previous embodiment and has similar parts. For example, the pulley assembly 226 includes a pulley member 206, hub 252, thrust element 263 having a sleeve portion 264, ball bearing assembly 218, resilient element in the form of a coil spring 274, spring wrapped unidirectional clutch 276 having coils 288 of steel and friction material 290. The clutch 276 is attached to the spring 274 in a crimped connection 278. An annular thrust washer 291 is also included which serves to support the free end 292 of the clutch and to keep the free end of the clutch in place against the force of axial side loads that tend to force the end 292 axially outward. The main difference between the embodiment shown in figure 2 and the embodiment of figure 7 is the location of the ball bearing assembly of the decoupler (reference number 118 in figure 2 and reference number 218 of figure 7) and elements of bushing / sleeve (112, 64 in Figure 2 and 212, 264 in Figure 7). In particular, in the embodiment of Figure 2, the ball bearing assembly 118 is positioned towards the front end of the alternator pulley 26, spaced apart from the alternator frame 48, while the bushing 112 and the 64 are positioned towards the rear end of the pulley 26, closer to the alternator frame 48. In this embodiment of Figure 2, the bushing 112 and bushing 64 receive most of the bending moment or curvature applied by the band 20 to the shaft 36 of the alternator. In this configuration, more of the band load is carried by the bushing 112 and bushing 64 as compared to the amount of load carried by the bushing 118. This configuration is better suited for higher damping requirements. In the embodiment of Figure 7, the ball bearing assembly 218 is positioned towards the rear end of the alternator pulley assembly 226, closer to the alternator frame 48 than the bushing 221 and the sleeve 462, which are disposed in the front end of the pulley.

In this arrangement, the ball bearing assembly 218 leads to the majority of the bending or bending moment of the alternator shaft 36 and is particularly beneficial for torsionally stronger applications and where less damping is required. According to the invention, the configuration of the generally helical coil of the spring steel 74 or 274 and the wrapped clutch spring member 76 or 276 collectively results in a unidirectional coil spring / clutch which provides manual protection for the coil spring (74, 274) also as the wrapped clutch spring element (76, 276). In particular, because the wrapped clutch spring element (76, 276) has improved clamping action compared to previous designs, the wrapped clutch spring efficiently and immediately holds the inner sleeve during the driving or propulsion condition when the mechanism coil spring and unidirectional clutch serves to transmit movement imparted to the pulley element 106, 206 by the band 20 to the hub structure 52, 252. The improved clamping action of the clutch member 76, 276 provides virtually no slippage in the driving condition or propulsion and relieves the wear that would occur in an arrangement in which the spring steel is used for the clutch, such as in the US patent No. 5,156,573. In addition, the configuration of the torsion spring 74, 274 and the wrapped clutch spring element 76, 276 also results in the wrapped clutch spring member 72, 276 providing protection for the elastic spring member 74, 274 during the condition of Runaway when protecting the spring 74, 274 of the reverse voltages. On the other hand, the coil spring 74, 274 protects the wrapped clutch spring member 76, 276 from undergoing self-oscillations during the driving or reversing condition to relieve the stress on the wrapped clutch spring. • Preferably, the elastic spring element 74, 274 is a relatively "soft" spring that can be used because the clutch mechanism 76, 276 will be released to protect the spring during the interruption or shutdown of the system. Because a softer spring is used, the drive or propulsion frequency can preferably be reduced to less than 75% of the minimum speed frequency. For example, where the minimum or idle speed frequency is triggered at 30 Hz, the drive or propulsion frequency can be triggered at as little as 15 Hz, which is 50% of the drive frequency. The drive frequency is preferably between 50% -75% of the inactive frequency. In this arrangement, the resonance of the spring is at lower speeds and only to be present during shutdown and / or starting. The clutch works to protect the spring during resonance. There are four main operations associated with the resilient element and the unidirectional clutch mechanism 72, 272 which includes operation while at rest, operation during acceleration, operation at constant speed and operation during deceleration. This will be described by reference to the first embodiment as shown in Figure 5. However, it should be appreciated that other principles of operation apply equally to other modalities, such as the embodiment of Figure 7.

Operation at rest At rest, the spring element 74 is at a torque and moment of zero. There is no rotational movement imparted by means of the pulley 26 which is also at rest when the engine is at rest. The wrapped clutch spring element 78 remains slightly preloaded radially outward in engagement with the surface 110 due to the combination of material characteristics and construction, but there is no moving frictional surface at this time.

Operation During Acceleration When the pulley 26 is rotated by the application of a driving belt force, the wrapped clutch spring member 76 engages immediately at the free end 92 by means of the friction created through the surface contacts of the material 90. in the first coil 92 of the clutch. The geometry of the spiral multiplies the holding force that facilitates the transparency of the torque to the elastic or resilient element, preferably in the form of the spring element 74. As the applied load increases, the elastic spring element 74 will flex by a corresponding amount until equilibrium is reached. The centrifugal forces improve the holding capacity of the clutch 76 since the holding capacity is a function of the number of turns of the clutch that makes contact with the driving surface 110 and the coefficient of friction between the friction material 90 and the surface 110. Expansion of the spring 74 into the hub 52 creates forces that reinforce the clamping action as the acceleration continues to take place. If the driving pulley 26 continues to accelerate, the torque load increases substantially as long as the torsional fluctuation is minimal. The clutch 76 will transmit the load to the spring 74 causing the spring 74 to flex further in one direction while working to maintain dynamic balance. The incorporation of the plastic separator element 100 controls the alignment of the spring 74 and limits the final amount of deflection possible. More importantly, the spacer element 100 axially balances the spring 74 by opposing the tilting force applied by the spring which is effected by the tangential force applied by the friction material 90 in the driving or propulsion condition. Because there is no relative movement between the plastic separator 100 and the pulley element 106 in the driving condition, there is relatively little wear on the surfaces compared to the alternative arrangements, for example where the plastic parts are positioned on the inside of the pier. By providing the space or spacing G (as shown in FIG. 3) between the coarse position 102 of the spacer element 100 and the friction material 90, the spacer member 100 allows the end portion 117 of the friction material 90 (opposite the free end 92) is urged radially outward in frictional engagement with the surface 110 of the pulley element 106 in the driving direction. Otherwise, without the formation of the space G, the spacer 100 can cause a substantial portion of the last clutch spool 117 to remain out of engagement with the surface 110 when urging the spring 74 and subjecting this portion 117 of the clutch to a flex and significant weakening.

Constant speed operation Under a steady state rated speed with fluctuations due to torsional vibrations, the spring 74 flexes as the torque fluctuates. This always occurs in the positive stress region of the spring's operating range. The net effect is to isolate the majority of the torque transfer between the input and output elements of the device, the energy absorbed is dissipated as heat. While operating at constant speed, the clutch 76 remains stationary with respect to the pulley element 106. During this mode, the clutch 76 rotates at the same speed as the pulley element 106 of the driven alternator shaft.

Operation during deceleration 'When the deceleration of the driving belt 20 occurs, such as deceleration or stopping of the engine, the inertia of the alternator will resist the change in speed. The mass of the alternator armature resists the change in speed and puts great stresses on the band system. As the rotational speed of the pulley 26 decreases to a level lower than that of the mass of the driven rotor or armature (relative negative torque), the spring 74 will return to a no-load condition will continue to be driven in the negative direction. At this point the conditions for the operation of the clutch become unfavorable and the transfer capacity of the torque is minimal. The armature is now free to rip off with a slight frictional drag on the free end 92 of the clutch coil until the relative speeds between the input and output shafts become positive. Since the clutch 76 is not capable of transmitting torque, the spring 74 remains substantially free of stress. Because the present invention temporarily eliminates the inertia of the system under conditions of deceleration of the driving belt, the durability of the system is improved and a small improvement in overall fuel efficiency can be obtained. By controlling excessive torsional vibration and by allowing inertial runaway during changes in engine speed and shutdown, the resilient element and unidirectional clutch mechanism comprised in the present material provide improved system durability and fuel economy.

Each of the following embodiments illustrates other alternator uncouplers that provide separate spring elements and clutches that are joined in series to transmit rotation between the alternator pulley element and the mounting hub. In each example, these alternator decouplers or pulley assemblies can be placed on the shaft 36 of the alternator of Figure 1 instead of the pulley assembly 26 illustrated in that figure. Figure 8A is a cross-sectional view of a third embodiment of a decoupler and alternator pulley assembly in accordance with the principles of the present invention. In Figure 8A, the alternator decoupler assembly is generally indicated with the number 300. The decoupler assembly 300 has a sleeve member 302 having internal threads 304 which allows the sleeve 302 and the entire decoupler assembly 300 to be clamped on the end of an alternator drive shaft. The sleeve element 302 is fixed for rotation with the alternator shaft. A poly-V band pulley element 306 is mounted on the sleeve 302. The pulley member 306 has a plurality of alternating ribs and grooves 308 constructed and arranged to engage the slits and ribs of a poly-V band. In a preferred embodiment, six slits are provided for coupling with six ribs of a band. For a band having six ribs and grooves, the preferred bandwidth is about 25 mm. The alternative preferred arrangements, the band has 5, 7 and 8 ribs and from here, the pulley 306 would have a corresponding number of slits. The ribs and slots 308 are provided in a relatively narrow diameter portion 310 of the pulley member 306. The distal end or forward end of the pulley member 306 (i.e., the end of the pulley member that is furthest from the alternator or block of the motor) has a 312-diameter enlarged portion that. It forms a cylindrical wall. A wall portion 314 extending radially outwardly joins the enlarged diameter portion 312 with the narrow diameter portion 310. A bearing member 310 is disposed between a cylindrical outer surface 318 of the sleeve member, 302 and the cylindrical inner surface 320 of the narrow-bore portion 310 of the pulley member 306. During the proper coiling condition, the bearing element 316 it allows a relative rotation between the pulley 306 and the sleeve element 302. The bearing 316 may simply be a bushing, similar to bushing 318 shown in the first embodiment. It is contemplated that where the bearing element 316 is in the form of a bushing, a lubricated metal or polymeric substance can be used with the polymeric substance which is preferred for most applications. In applications where a higher degree or frequency of runaway is anticipated, powdered metal may be preferred because it exhibits better qualities and characteristics of high speed spinning of the pulley and at the same time exhibits appropriate capabilities for small oscillations of the pulley. The powder exhibits superior qualities for high speed spin, as it contains oils or lubricant components in its composition to provide a naturally lubricated bearing element. Polymer bushes are usually preferred, since they are more resistant to wear by long oscillation periods. Alternatively, it is contemplated that the bearing element 310 may be in the form of a needle bearing. A conventional needle bearing that has an internal and external track can be used. Alternatively, the sleeve 302 may have an inner race machined or otherwise formed on the outer surface 318 thereof, such that the needle bearing element may simply comprise a needle element and an outer race snapped on the sleeve 302. In the embodiment shown in figure 8A, the enlarged diameter portion 312 is closed at the front end thereof by an annular disc element 321, which is fixed at its outer periphery to the edge of the enlarged diameter portion 312 and fixed at its inner edge to the outer edge. outer surface 381 of the sleeve element 302. The disc element 321 cooperates with the enlarged diameter portion 312 to define a housing or housing for a resilient element and interconnected unidirectional clutch mechanism generally indicated with the number 322. In this embodiment, the resilient element and the clutch mechanism 322 The unidirectional joint comprises a resilient element in the form of a spring structure 324 of rubber or compression-type rubber. As can be seen from Figure 8B, the structure 324 of the rubber or rubber spring comprises a plurality of radially extending radiation-like elements 326. The elements of the spring 326 are fixedly mounted on a cube structure, indicated generally with the number 328. The cube or center structure 328 which is made of a metal material, such as steel and has an inner surface thereof fixed rigidly to the outside of the metal sleeve 302. The cube structure 328 may be attached to the sleeve member 302 in any conventional manner, such as when being snapped or welded thereto. The cube structure 328 has a portion 330 of generally cylindrical cross section and a plurality of in turn fits the sleeve 302 and axis of the moving alternator. The radially outer or peripheral surface of the spring elements 326 are vulcanized or otherwise fixed to an annular carrier plate 334 made of a metallic material such as steel or aluminum. Mounted between the carrier plate 334 and the cylindrical inner surface of the enlarged diameter portion 312 is a clutch assembly 336. Preferably, the clutch assembly 336 is of the type described in U.S. Patent Application No. 08 / 817,799, hereby incorporated by reference. Further, preferably the carrier plate 334 according to the present invention comprises an annular band which is similar to the band comprising the circumferential surface of the carrier plate described in the aforementioned application No. 08 / 817,999. With reference to Figures 19, 20 and 21 the clutch assembly 336 comprises a portion 342 of a single band joined to two parallel bands 344 and 346. The bands 344 and 346 are joined together by a bridge 348 to stabilize the bands 344 and 346. The webs 344 and 346 also have tabs 350 for centering the web on the outer circumferential surface of the carrier plate 334. As can be seen from the aforementioned application No. 08 / 817,799, the outer circumferential surface of the plate carrier 334 has a circumferential groove for receiving a tongue 352 from the end disposed at the end of the single band portion 342 and the band 342 extending radially inward is passed over the bridge 348 as can be seen from the figures. In the present invention, it is preferable that the clutch assembly 336 be fabricated from spring steel and having an outer surface 357 made of a friction material, such as the first two embodiments. In this manner, a free end 360 of the individual band portion 342 is preloaded in a radially outwardly-driven direction for frictional engagement with the cylindrical inner surface of the enlarged diameter portion 312. When the pulley element 306 is rotated by the belt, the pulley 306 is rotated in the driving direction as indicated by the arrow in FIG. 19. The rotation of the pulley element 306 in this direction causes the inner cylindrical surface of the pulley 306 to rotate. the enlarged diameter portion 312 immediately engages frictionally with the free end 360 of the clutch assembly 336. Then the clutch assembly 336 is "self-energizing" as increased portions thereof clutch frictionally with the cylindrical interior surface of the enlarged portion 312., until the entire surface 357 of the outer friction material, in which the parallel band regions 334, 346 are included, is in frictional engagement. The bands 344 and 346 are attached to the outer circumferential surfaces of the carrier plate 334 when using rivets 355. Other suitable fasteners such as nuts and bolts may also be used. In an alternative embodiment and as described in application No. 08 / 817,799, the clutch assembly 336 need not comprise a spring material urged radially outward so that the free end 360 is preloaded in frictional engagement. Rather, a spring (such as a coil spring) can be attached to the free end 360 (for example between the free end of the carrier plate) to drive the free end to a preloaded condition against the inner surface of the portion 312 of expanded diameter. By driving the clutch assembly with a preloaded spring, as with the previous embodiments, the bands 342, 344 and 346 will slide when they move relative to the inner surface of the portion 312 in one direction and will engage frictionally with this surface when slide in the opposite direction. In this way, the unidirectional clutch will transmit the torque of the pulley member 306 to the alternator during the driving condition of the belt, which will slide relative to the pulley during the driving direction. In Figure 9A a fourth embodiment of an alternator decoupler according to the present invention is shown. The identical parts are indicated with the same reference numbers as shown in Figures 8A and 8B. The main difference between the arrangement shown in Figure 9A as compared to that in Figure 8A is the use of a rubber spring element or rubber-like type 370 instead of the spring structure 324 of rubber or compression-type rubber. The cut-type rubber spring 370 has its annular radially internal surface 334 vulcanized or otherwise fixed to the outer periphery of an annular sleeve element 372, which in turn is fixed to the cylindrical outer surface of the sleeve 302. A peripheral surface 376 of the cutting spring 370 is vulcanized or otherwise fixed to the carrier plate 334 which is identical to the carrier plate discussed in the embodiment with respect to Figures 8A and 8B. In the idle condition, the rubber cutting spring 370 is compressed between the inner sleeve member 372 and the external carrier plate 334. A spring clutch assembly 336 as discussed previously is fixed to the carrier plate 334 and is constructed and arranged to establish a frictional engagement with the internal cylindrical surface of the enlarged diameter portion 312. The driven rotation of the pulley 306 is transmitted by means of the clutch assembly 336 and the cutting spring 370 to the alternator shaft via the sleeve element 302. In figures 10A and 10B a fifth embodiment according to the principles of the present invention. In Figures 10A and 10B, a plurality of compressor block rubber springs 386, 388 are used as the resilient member that connects the unidirectional clutch 336 to the inner sleeve 302 and hence the shaft of the alternator. In this embodiment, a carrier plate 378 is modified in comparison with the carrier plate embodiment shown in FIGS. 8A, 8B, 9A and 9B. In particular, the carrier plate 378 is added or incorporated or a plurality of projections 380 extending radially inward from circumferential positions equally spaced from the radially inner surface of the path of the carrier plate. The carrier plate 378 and the projections 380 thereof are preferably made of steel as an integral structure. Mounted fixedly on the sleeve 302 is an element 282 of hub or annular center. A plurality of projections 384 extending radially outward extend from circumferential positions equally spaced on the outer surface of the hub member 382. Preferably, the projections 384 are made of steel and formed integrally with the cube element 382 although they can be provided separately and fixed to the cube element 382. The projections 380 extending from the carrier plate 378 and the projections 384 extending from the Cube element 382 are alternately arranged in a circumferential direction. A plurality of compression block-type coupling springs 386 are provided between the projections 380 and the projections 384, when seen in Figure 10B which move from the projections 380 to the projections 384 in the clockwise direction. In Figure 10B the pulley element 306 and hence the portion 312 of enlarged diameter thereof is driven by the band in the clockwise direction. The clutch assembly 336 transmits the rotation of the enlarged diameter portion 312 to the carrier plate and hence to the projections 380 thereof. The rotational movement in the clockwise direction is imparted by means of the thrust springs 386 to the projections 384 extending from the hub element 382. Thus, it can be seen that the clockwise rotation of the Pulley element 306 is imparted to sleeve 302 and to the alternator shaft fixed thereto. In the condition shown, the thrust springs 386 are in a compressed condition between the projections 380 and 384. As they extend from the projections 384 to the projections 380 in the clockwise direction, a plurality of elements 388 of the runaway compression spring. These spring elements 388 are shown in a relaxed condition in Figure 10B but will be compressed in the circumferential direction during the runaway condition when the alternator shaft rotates faster than the pulley member 306 and the clutch slides relative to the 312 portion of enlarged diameter. The spring elements 386 and 388 need not be fixed to the projections 380 and 384 on opposite sides thereof, but it is preferred to have the rubber springs fixed to the projections. In FIGS. HA and 11B a sixth embodiment according to the principles of the present invention is shown. The embodiment shown in FIGS. HA and 11B differs from the embodiments shown in FIGS. 8A, 8B, 9A and 9B mainly in that a spring 390 of flat torsion wire is used in place of the rubber springs. The spring 390 is wound spirally around hub or annular center 392. A radially internal end 394 of the spring 394 is fixed in any conventional manner to the hub or hub 392. The hub 392 has a radially internal cylindrical surface thereof fixed to the sleeve 302. The portion 396 of the radially outer end of the spring 390 is fixed to the carrier plate 334 discussed above with respect to Figures 8A-9B. The end portion 396 can be fixed to the carrier plate 334 by rivets, welding, etc. Carrier plate 334 and clutch assembly 336 operate as previously indicated. In Figures 12A and 12B a seventh embodiment according to the principles of the present invention is shown. This embodiment is substantially similar to that shown in Figures HA and 11B, except for the use of a double twist flat wire spring assembly 400 which is replaced by the single flat wire spring 390. The central hub 402 is fixed around the sleeve 302 as indicated above with respect to Figures HA and 11B. However, in this embodiment, the spring assembly 400 comprises a first coil winding spirally wound wire spring element 404 and a second spiral wire coil spring element 406. The first spring member 404 has a radially internal end 408 thereof fixed to the hub member 402, while the second spring member 406 has a radially internal end 410 thereof fixed to the hub member 402. The fixed ends 408 and 410 are joined at circumferentially spaced locations at approximately 180 ° to each other as shown. A radially outer end 412 of the first spring 404 is fixed (for example by rivets) to the radially inner surface of the carrier plate 334. Similarly,, the radially external end 414 of the second spring element 406 is fixed to the radially internal surface of the carrier plate 304 in any conventional manner. The attached ends 412 and 414 of the respective spring elements 404 and 406 are joined to the radially inner surface of the carrier plate 334 at circumferentially spaced locations, about 180 ° to each other. An advantage with respect to the embodiment of Figures 12A and 12B is that the two opposed springs 404, 406 provide a self-balancing effect which tends to eliminate the impending imbalance of all individual metal spring designs. In Figures 13A and 13B a thirteenth embodiment according to the principles of the present invention is shown. This embodiment is substantially similar with the embodiment shown in Figures HA and 11B except that a torsion wire spring having a circular cross section configuration is used in place of the flat spring 390. The wire spring, generally indicated with the No. 418, has its radially internal end 420 fixed to a central hub 422. In turn, central hub 422 is fixed around the central sleeve 302. The embodiment shown in Figures 13A and 13B also differs in that the end portion 423 The radially external spring of the resilient spring 418 is fixed to the carrier plate 334 by a crimped connection 424 similar to the connection 78 discussed with respect to the first embodiment described. While welding of this outer end 423 to the carrier plate 334 is possible, it is preferred to use the crimped connection 424 to receive benefits similar to those received with the connection 78. It is also preferable that the portion 423 of the outer end be provided with the flat portion 82 and that the carrier plate has improved crimped portions 89 as can be seen from Figure 4. The embodiments shown in Figures 8-13 are advantageous because the use of the enlarged diameter portion 312 allows a larger radius for the clutch assembly 336 in relation to the diameter of the portion engaging with the narrow diameter band or portion 310 of the pulley member 306. Because the clutch assembly 336 is provided with a larger radius, it is required fewer coils or clutch wraps for frictionally engaging and holding the inner surface of portion 312 to drive the same amount of torque from l Alternator shaft compared to the number of coils or turns required for a smaller radius clutch. Where fewer coils or clutch turns are required, making the assembly becomes simpler. In figure 14 a ninth embodiment according to the principles of the present invention is shown. In Figure 14, the alternator decoupler, generally indicated with the numeral 430, includes a pulley member 432 having a plurality of slits 434 for receiving the ribs of a poly-V band. The decoupler 430 further includes a pusher element 436 and a mounting sleeve member 438 for mounting the decoupler on the end of an alternator shaft. The push member 436 has a cylindrical sleeve portion 440 that is concentrically disposed about the mounting sleeve 438. The sleeve portion 440 has a cylindrical interior surface 442 and the mounting sleeve 438 has a cylindrical outer surface 444. A mounting 446 needle roller bearing is disposed between the inner surface 442 of the push member 436 and the outer surface 444 of the mounting sleeve 438. The needle bearing assembly 446 mounts the push member 436 for rotation relative to the sleeve 438 of mounting. The push member 436 also includes a wall portion 448 that extends radially outward from the front end (away from the engine block and alternator) of the 440 portion. of sleeve. The push member 436 further includes a cylindrical flange portion 450 extending from the wall portion 448 in an axial direction toward the engine block from which the alternator shaft extends. The flange 450 is generally arranged concentrically with respect to the cylindrical sleeve portion 440. The pulley element 432 has a flange portion 452 at the front end thereof as shown. An outer cylindrical surface of the flange portion 452 frictionally engages the inner cylindrical surfaces of the rim 450 of the push member to form a rigid connection therebetween. As an alternative to a simple frictional connection or press fit, the flange 452 of the pulley element 452 can be fixed in another way, such as when being welded, to the shoulder 450 of the push element 436. An appropriate seal element 454, such as a nylon ring seal is provided between the sleeve portion 440 of the push member 436 and the outer surface 444 of the mounting sleeve 438 in a slightly spaced position from the needle bearing 446 to the front end of the decoupler 430. The seal 454 provides a low friction seal between the surfaces 442 and 444 and prevents foreign matter from infecting needle bearing 446. A similar seal 456 is disposed between a wall 458 projecting radially inward from the pulley member 452 and a wall 450 projecting radially outwardly from the mounting sleeve 438. A unidirectional resilient element and clutch assembly is generally indicated with the number 462. The assembly 462 includes a resilient element in the form of a torsion wire spring 464, the volutes of which have a circular cross-sectional configuration. Assembly or assembly 462 further includes a unidirectional clutch mechanism 466 of construction of material similar to clutch member 76 of the first embodiment. In particular, it is preferred that the unidirectional clutch mechanism 466 includes a steel strip made of spring material and a friction material adhered to the radially outer surface thereof. The friction material of the unidirectional clutch 466 is constructed and arranged to frictionally engage the cylindrical interior surface 468 of the pulley member 432. The spring member 464 is attached to the member. 466 unidirectional clutch in an annular connection 470 between them. In particular, the unidirectional clutch 466 has a volute 472 in width enlarged in the axially most forward portion of clutch 466. The forwardmost scroll 474 of the spring 464 has an enlarged diameter as compared to the other volutes of the spring and is constructed and arranged from such that the radially outermost peripheral surface thereof is arranged in annular frictional engagement with the inner surface of the expanded width scroll 472 of the unidirectional clutch. The volute 474 of the spring is driven in a manner that expands radially outwardly for engagement with the volute 472 of the clutch. Preferably, the enlarged width scroll of the unidirectional clutch 464 has a channel 476 formed therein to receive the peripheral surface of the spring volute 474 to establish the frictional coupling mentioned above, which coupling establishes a fixed, non-slidable connection, between the spring 464 and the unidirectional clutch 466. This connection can be improved by a welding or other configuration of mechanical fixation or crimping. However, due to the frictional engagement between the volute 474 and the channel 476 it extends substantially along the entire volute 474 and because the volute 474 has an expanded diameter, the frictional connection between the spring and the clutch is sufficient to maintain a rigid connection. The opposite end of the spring 464 terminates in a further rear annular volute 478 that establishes a fixed connection between the spring 464 and the mounting sleeve 438. More specifically, the sleeve 438 has an annular channel 480 formed on the outer surface thereof. The channel 480 is constructed and arranged to engage frictionally with the inner annular surface of the volute 478. The volute 478 is urged radially inwardly to rigidly engage the channel 480 and create a frictional and clamping condition between the sleeve 438 and the spring 464. It can be seen from figure 14 that the mounting sleeve 438 shown is a two-part construction, which includes a further axially forward portion 439 having internal threads for receiving the end of the alternator shaft and a further rear portion axially 441 to engage with the annular flange of the shaft. Tightening the decoupler 430 of the alternator at the end of the shaft causes the sleeve portion 439 to apply an axial force on the sleeve portion 441, to sandwich the sleeve portion 441 between the flange of the shaft and the adjacent annular end surface of the sleeve. portion 439. It can be appreciated that in an alternate construction, it is contemplated that the mounting sleeve 438 may comprise a unitary element formed integrally in place of the two-part construction shown. Because a needle bearing 446 is used in the construction shown in Figure 15, additional axial spacing is available for the spring 464 compared to the embodiments shown in Figures 2 and 7. More specifically, because it can be to make the needle bearing 446 have a smaller cross-sectional configuration and a smaller external diameter, the spring 464 may be disposed in surrounding relationship with respect to the bearing 446 without greatly increasing the overall diameter of the decoupler. Because the needle bearing does not interfere with the axially extending volutes of helical spring 446, the spring may be provided with more volutes within the same axially dimensioned decoupler as compared to those shown in FIGS. 2 and 7. Because more volutes can be provided, the entire volute 474 of the front end can be dedicated to making the connection with the unidirectional clutch member, to provide a stronger clutch or spring joint. further, because the spring can be made larger (more coils) the spring itself is stronger. Figure 15 shows a tenth embodiment of an alternator decoupler according to the principles of the present invention. The embodiment shown in Figure 15 is identical to that shown in Figure 2, with the exception of the use of a wire spring element 490 having volutes of rectangular cross section instead of the coil spring element 74 having section volutes. circular cross Similarly, Figure 16 is identical in structure with the decoupler assembly shown in Figure 7, with the exception of a rectangular wire spring 492 replaced by the spring assembly 274. Figure 17 shows a twelfth embodiment of the decoupler according to the principles of the present invention. In this embodiment, a pair of needle bearings 494 and 496 are used between the outer surface of a mounting sleeve 498 and an inner surface 500 of the pulley member 502. The needle bearing 494 is located at the axially front end of the assembly of decoupler and the needle bearing 496 is disposed at the axially rearward end of the bearing assembly. Turning now to FIGS. 18A and 18B, a thirteenth embodiment of an alternator decoupler according to the principles of the present invention is shown. The configuration shown in Figure 18A is substantially identical to that shown in Figure 9A. Figure 18A differs essentially from Figure 9A in that the ball bearing assembly 494 is used in place of the bearing element 316. The ball bearing assembly is generally centered below the narrow diameter portion 310 of the pulley member. 306, such that the band engaging the narrow diameter portion 310 is axially balanced on the ball bearing assembly 494.

As shown, the mounting sleeve 496 for mounting the decoupler on an alternator shaft is preferably a two-part construction including a front sleeve member 498 and a rear sleeve element 500, with the ball bearing assembly arranged between them. The ball bearing assembly 494 has an inner track 502 thereof constructed and arranged to be snapped into a rigid, non-slip coupling on the alternator shaft, which is received by the mounting sleeve 406. The mounting sleeve 496 is provided with a beveled portion 504 adjacent to the ball bearing assembly 494, as can be seen from Figure 18B. The beveled portion has a first surface portion 506 that is disposed substantially perpendicular to the axis of rotation of the shaft. In addition, the beveled portion 504 includes an angular surface 508 that is angled with respect to the surface 506. The angle between the surfaces 506 and 508 is preferably between about 145 ° and 155 °. The surfaces 506 and 508 serve to mount the sleeve. 496 exactly on an associated alternator shaft. In particular, when the mounting sleeve 498 is tightened on the alternator shaft, the angular surface 508 centers the sleeve 498 with respect to the shaft axis. Prolonged tightening of the sleeve 498 on the shaft causes the surface 506 to be leveled against the lateral surface of the inner track 502. Figure 22 is a cross-sectional view and Figure 23 is an exploded view of a fourteenth embodiment of the invention. a runaway alternator decoupler according to the principles of the present invention. The alternator decoupler, indicated generally with the number 600, includes a generally cylindrical steel pulley element 606 having slots 607 of poly-V. The pulley member 606 is constructed and arranged to engage with the poly-V band 20 of the coil drive system 18 illustrated in Figure 1 to receive a drive or drive force thereof and to operate as part of the decoupler 600 that transmits such force to the alternator shaft 36 on which the alternator decoupler 600 is mounted. The decoupler 600 of the alternator is mounted on the end of the alternator shaft 36 via the cube structure 608. The cube structure is provided as a portion of the generally cylindrical wall 609, the inner surface of which is provided with threads 610 for allowing the cube structure 608 to be threaded to cooperating threads on the end portion of the alternator shaft 36. Towards the front end of the cube structure 608, the inner surface is provided with multiple flat parts extending around the circumference, to form a tool receiving receptacle 612, which provides a receptacle in which a tool can be used to rotate the hub structure 608 about the axis rotationally and thereby threadedly secure the cube structure 608 on the end of the alternator shaft 36. The generally cylindrical wall portion 609 of the cube structure 608 has an annular flange portion 612 integrally formed, which extends radially outwardly. The flange portion 612 has an annular forward facing surface 614, with a slit 616 formed therein. Slit 616 is arcuate in cross section and extends only partially around the circumferential extension of annular surface 614. Slit 616 abruptly ends at a perpendicular end wall seal, as best shown in Figure 23. Slit 616 it deepens as it extends towards the end retainer 618, where it ends abruptly in the perpendicular wall 618. The end retainer wall 618 serves as a retaining surface or support for an end 620 of a coil spring 622 made of steel for springs. The spiral spring volutes 622 are arranged in spaced relation surrounding the outer surface of the cylindrical portion 609 of the cube structure 608. An opposite end 624 of the coil spring 622 engages a perpendicular wall or end catch 628 formed in a carrier connection structure 630 of plastic (preferably based on nylon). More particularly, the carrier connection structure 630 comprises a main body portion 632 of a generally cylindrical configuration and an annular ring structure 634 formed at the forward end of the cylindrical body portion 632. Preferably, the connecting structure 630 is formed integrally by injection molded plastic in a one-piece structure including the main body portion 632 and the ring portion 634. Figure 24 is a plan view of the near end of the carrier connection structure 630 (that is, as it would face the engine block). An annular surface 636 of the ring structure 634 is facing in an axial direction towards the engine block. A radially inner portion of the surface 636, within the circumference defined by the main cylindrical body portion 632 is provided with an arched groove 638 of similar configuration as the previously described groove 616. The aforementioned end retainer or perpendicular wall 628 forms the end of the slit 638 in the deepest portion of the slit 638. The end detents or walls 628 and 618 provide a sufficient surface area for the proper coupling so that the opposite ends 620 and 624 of the spring allow the connecting carrier 630 rotationally urges the end 624 of the spring 622 about the axis of rotation of the decoupler 600 and that the end 620 of the spring 622 rotationally urges the hub 608 about the axis of rotation. The ring structure 634 has a groove 640 extending through the thickness of the ring structure 634 in the axial direction. The slot 640 has a generally spiral portion 642 extending from the outer circumference of the ring structure 634 in a circumferential direction and extending radially inwardly. The slot 640 further includes a radially extending portion 644, which extends radially from the radially innermost portion of the spiral portion 642 radially outward and has a length of about one third of the radial extent of the ring structure 634 In general, the intersection of the slit portions 644 and 642 forms a right angle. It can be seen from the figures that the direction of the indentation 640, taken as it extends from the outer periphery of the ring structure 634 in a circumferential direction and radially inward, extends in a circumferential direction opposite to the direction in which the slit 638 becomes deeper as it approaches the retaining wall 628 of the end. When the decoupler 600 is at rest, the spring 622 is arranged in spaced relationship between a cylindrical interior surface 633 of the cylindrical portion. 632 of the carrier 630 and a cylindrical outer surface 611 of the wall portion 609. The slot 640 in the ring structure 634 is constructed and arranged to form a connection with one end of a wrapped clutch spring structure 652 and in particular one end folded or tongue 650 of the structure 652 of wrapped clutch spring. The end 650 of the wrapped clutch spring is bent to a right angle configuration, such that the angled or tongue portion 654 can be received in the radially extending portion 644 of the slit 640. The immediately adjacent portions 656 of the clutch 652 then extend through the spiral portions 642 of the slit 640. As long as the connecting end 650 of the wrapped clutch spring 652 is disposed radially inward relative to the main body portion 632 of the connection carrier 630, after the wrapped clutch spring 652 leaves the slit 640, it is disposed in a generally surrounding relationship with the main body portion 632.

The pulley element 606 has a cylindrical inner surface 660, the forwardly disposed portions of which are in surface engagement with a cylindrical surface 662 facing radially rearward of the ring structure 634. As shown in the cross-sectional view of Figure 22, most of the wrapped clutch spring assembly 652 is disposed within a space 666 between the inner cylindrical surface of the pulley member 606 and the outer surface of the cylindrical portion 632 of the carrier connecting structure 630. wrapped clutch spring 652 comprises a material 668 of resilient spring steel in a radially inner portion thereof and a friction material 670 glued to the radially outer surface of the steel spring 668 as described in detail for the first and second embodiments of the Figures 2 - 7. Also as with the first two modes, clutch 652 has a diameter in s u free state (for example as shown in the exploded view of figure 23) having a diameter greater than the diameter defined by the inner surface 660 of the pulley element 606. Thus, when the decoupler 600 is assembled, the material 670 of the clutch coils 652 are in continuous driven engagement with the inner surface 660 of the pulley member 606.

A ball bearing assembly 672 assembles the pulley element for rotation with respect to the hub structure. In particular, the ball bearing assembly 672 has an outer track 674 that snaps under the inner surface 660 of the pulley member 606 and its inner track 676 press fit to an outer surface portion 678 of the hub structure 608, in a position of the cylindrical wall portion 609 closest to the motor or alternator on which this decoupler 600 is mounted. An annular bushing 680 is disposed in surrounding relationship with a portion of the pulley element 606 that is disposed forwardly of the slots 607 of poly-V. The portion 682 has a substantially smooth cylindrical outer surface. The radially inwardly facing surface of the bushing 680 is arranged in surface engagement with the smooth cylindrical outer surface of the portion 682. The radially outwardly facing surface of the bushing 680 is arranged in surface engagement with an inner cylindrical surface of a wall 689. cylindrical radially outward from an extreme annular cap 690. The end cap 690 forms an annular channel 692 facing axially rearward, of a generally U-shaped cross-sectional configuration. The channel 692 of the end cap 690 receives the distal end portion 682 of the sheave member 606, the portion of ring 634 of the carrier connection structure 630, the connection end portion 650 of the wrapped clutch spring 652, the end 624 of the coil spring 622, also as the bushing 680. A wall portion 696 disposed radially inwardly of the bushing 680 has a generally cylindrical configuration having a radially inward facing surface that engages the surface outer cylindrical of the distal end of the cylindrical wall portion 609. In particular, the cylindrical wall portion 609 has a stepped or radially reduced outer diameter portion 698 that is constructed and arranged to accept the thickness of the radially cylindrical wall portion 696 internal, of the end cap 690, in interference fit ratio. The end portion 682 of the pulley member 606 is further provided with a groove 697 for O-ring, which is constructed and arranged to receive an O-ring 699 of rubber (or rubber) at a position between the bushing (680) and the grooves 607 of poly-V. In operation, the rotational movement of the pulley member 606 in the direction of arrow A in Figure 23 will cause a free end 657 of the clutch to be engaged and driven. As in the first embodiment, increased portions of the clutch 625 function to transmit rotational force of the continuous input of the pulley member 606. The driving movement of the pulley member 606 in the rotational direction indicated by the arrow A causes the clutch 652 to be rotated. in a similar direction as indicated by arrow B. Because end 650 of clutch assembly 652 is fixed to connection carrier 630 in slot 640, the carrier is driven in the same direction as indicated by arrow B As a result, the end wall of the groove 628 provided in the ring structure 634 engages the end 624 of the coil spring 622 and urges the spring also in the direction of the arrow B. The opposite end 620 of the spring 622 engages in turn with the end wall or retaining surface 618 formed at the end of the slit 616 in the flange 612 of the cube structure 608. This in turn drives the shaft 36 of the alternator in the direction of the arrow C. During this driving operation, the spring 622 expands under the load to provide elasticity for the insulation between the pulley 606 and the shaft 610 of the alternator. In addition, the spring 622 provides frequency reduction. The expansion of the spring 622 is limited by the cylindrical inner surface 633 of the cylindrical portion 632 of the connecting carrier structure 630, to prevent undesirable over-expansion of the spring 622.

As with each of the embodiments described herein, the resilient spring element 622 transmits the rotational movements driven from the alternator pulley 606 by the serpentine belt to the hub structure 608, such that the alternator shaft 610 it is rotated in the same direction as the alternator pulley 606, in that it has the capacity of instantaneous relative resilient movements in opposite directions with respect to the alternator pulley 606 during the rotational movement driven thereof. The unidirectional clutch member 652 is constructed and arranged to allow the hub structure 608 and hence the shaft 610 of the alternator to rotate at a speed greater than the rotational speed of the alternator pulley 606 when the output shaft speed 14 of the The motor is decelerated to a sufficient extent to establish the torque between the alternator pulley 606 and the cube structure 608 at a predetermined negative level. Fig. 25 is an exploded view of a fifteenth embodiment of a runaway alternator uncoupler, generally indicated with the number 700, in accordance with the principles of the present invention. This embodiment is substantially similar to the fourteenth modality illustrated in Figure 23 with the following exceptions. Similar parts have been indicated with similar reference numbers. The main difference in the embodiment shown in FIG. 25 and the previous embodiment resides in the direction in which the coil spring, indicated generally with the number 722, is wound in comparison with the coil spring of the previous embodiment. The spring 722 is wound in an opposite direction as compared to the spring of the previous mode, in such a way that the spring 722 will contract when the shaft 36 of the alternator is driven by the pulley element 606. The coil spring 722 has an end 724 thereof comprising a bent projection extending in the axial direction away from the engine block. The spring 722 further has a projection 726 of the opposite end extending from the coils in a direction opposite that of the first end 724, in a direction toward the engine block. The decoupler 700 of the alternator has a cube structure 708 that is substantially the same as the cube structure of the previous embodiment, except that it has a flange portion 712 that is provided with an axially extending hole 718, which it is used to replace the slit and end wall or retainer at the end of the previous mode. The hole 718 is constructed and arranged to receive the end 726 of the coil spring 722. The decoupler 700 of the alternator has a carrier connection structure 730 that is substantially identical to the carrier structure previously described, with the exception that a hole 728 that is axially extending is provided in the ring structure 734 in place of the slit and end wall or end retainer provided in the ring structure 634 of the previous embodiment. The hole 728 in the ring structure 734 is constructed and arranged to receive the projection 724 from the end of the coil spring 722. Figure 26 is a rear plan view of the carrier connection structure 730. As shown, the carrier 730 has the identical clutch receiving slot 640 described with respect to the previous embodiment. This embodiment also includes a clutch member 652, pulley element 606, portion 680 and identical end cap 690. According to the modality shown in the figures and 26, it should also be noted that the driven rotational movement of the pulley member 606 in the direction indicated by the arrow A effects the driven movement of the clutch 652 in the direction of the arrow B, as in the previous embodiment. The driven movement of the clutch 652 causes the driven movement of the carrier connection element 730 also in the rotational direction of the arrow B. This rotational movement of the carrier connection element 730 is transmitted to the end 724 of the coil spring 722 and causes the coil spring 722 to contract from such so that the shrinkage of the coils will be limited by an outer cylindrical surface 709 of the cube structure 708. The opposite end of the spring 722 then drives the cube structure 708, which in turn drives the alternator shaft 36. Because the outer cylindrical surface 709 limits the amount of contraction of the coil spring 722, the spring 722 is prevented from overcoiling. In each of the described embodiments, the clutch and spring elements of the alternator uncoupler are two separate elements connected in series with each other between the pulley element and the hub or assembly center. As a result, the spring tension or elastic tension provided in the clutch and separate spring can be controlled independently. Thus, the flexibility of the spring steel can be increased (for example by making the steel in the clutch thinner or by changing the narrowness of the coils) to have a much smaller spring ratio compared to that for the spring, such that the clutch material engages with the friction-bearing surface of the pulley element with less force in the runaway condition as compared to an arrangement where the clutch's flexibility is determined by what is required by the element of the clutch. dock. As a result, the clutch will have a relatively long life. Other advantages can also be appreciated from the description. Preferably, the resilient spring element has a torsional spring ratio of more than ten times the ratio of torsional spring of the clutch member. Optimally, for each embodiment described herein, the resilient spring element that transmits torsional rotation has a spring ratio of approximately 0.2 m-Kg to 0.029 m-Kg (2.0 to 2.5 inch-pounds) per degree of torsional deflection, in so much that the spring ratio of the spring steel used for the clutch has a spring ratio of approximately 0.0002 to 0.0003 m-Kg (0.02 to 0.03 inch-pounds) per degree of torsional deflection. Thus, the resilient spring element can have a ratio of torsional spring greater than one hundred times the ratio of torsional spring of the clutch element. Preferably, the resilient spring element has a spring ratio greater than about 0.011 m-Kg (1.0 inch-pounds) per degree of torsional deflection, while the clutch member has a spring ratio of less than 0.0011 m- Kg (0.1 inch-pounds) per degree of torsional deflection.

In each of the described embodiments, the coefficient of friction for the friction improving surface provided by the friction material has a coefficient of friction greater than that for steel. It is also preferable that the friction material for the clutch has a coefficient of friction greater than 0.25 and more preferably between 0.3-0.4 against the steel surface of the pulley. A further advantage is that by providing separate clutch and spring elements connected in series, they can be provided in at least partially axially superposed relation to each other, to carry out their functions in a relatively small axial spatial. In addition, because more axial space is provided for each of the clutch and spring, each can perform its respective functions more effectively. For example, because more clutch coils can be accommodated, less friction wear of the clutch occurs and grip or grip function is improved. Although not preferred due to the appreciable increase in manufacturing cost, instead of providing a unidirectional spring and clutch mechanism as separately formed but joined structures, it is possible to use a single integrally formed element that serves as the unidirectional spring and clutch when adapting particularly a single coiled or coiled metal structure, such that it has a substantial portion thereof that acts as the spring mechanism and another substantial portion thereof acting as the clutch mechanism. The clutch portion of the single coil can be modified to have a ratio of torsional spring at least ten times smaller than the ratio of torsion spring of the spring mechanism. This can be carried out for example by modifying the clutch portion by machining a portion of the coiled or wound metal material, such that it has a radial thickness smaller than the spring portion. As another aspect of the invention, the coefficients of friction of different portions of a single element can be altered by adhering a friction material to a portion of the wound or coiled metal material. It will thus be seen that the objects of this invention have been obtained fully and effectively. However, it will be noted that the above preferred embodiment of the present invention has been shown and described for purposes of illustrating the structural and functional principles of the invention and is susceptible to change without departing from such principles. Accordingly, this invention includes all modifications encompassed in the spirit and scope of the following claims and equivalents thereof.

It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Claims (57)

1. Claims Having described the invention as above, the content of the following claims is claimed as property: 1. A drive system (impeller or propulsion) of serpentine band for an automotive vehicle, characterized in that it comprises: a drive assembly or drive assembly including an internal combustion engine having an output shaft with a driving pulley thereon pivoted about an axis of the driving pulley, a sequence of driven assemblies each having a pulley driven rotating about a parallel shaft with the axis of the driving pulley and a serpentine belt mounted in cooperative relation with the driving pulley and with the driven pulleys, in a sequence corresponding to the sequence of driven assemblies when they are related to the direction of movement of the belt, for cause the driven pulleys to rotate in response to the rotation of the driving pulley, the secuence The assembly of driven assemblies includes an alternator assembly that includes an alternator shaft mounted for rotation about a shaft axis, a hub structure steadily carried by the alternator shaft for rotation therewith around the shaft axis and a unidirectional spring and clutch mechanism that couples the alternator pulley to the hub structure, the unidirectional spring and clutch mechanism comprises a resilient spring element formed separately from and joined in series with a unidirectional clutch element, the resilient spring element It is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the serpentine belt to the hub structure, in such a way that the alternator shaft is rotated in the same direction as the alternator pulley, while having capacity of relative instantaneous resilient movements in opposite directions with respect to the alternator pulley during the rotational movement driven thereof, the unidirectional clutch element is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a higher speed than the rotational speed of the alternator pulley when the output shaft of the motor is decelerated to a sufficient extent to establish the torque between the alternator pulley and the hub structure at a predetermined negative level. A serpentine band system according to claim 1, characterized in that the resilient spring element has a ratio of torsional spring greater than a ratio of torsional spring of the unidirectional clutch member. 3. A serpentine band system according to claim 2, characterized in that the ratio of the torsional spring of the resilient spring element is more than ten times greater than the ratio of the torsional spring of the clutch element. A coil strip system according to claim 1, characterized in that the unidirectional clutch member comprises a material having a coefficient of friction greater than a material of the resilient spring element. 5. A serpentine band system according to claim 4, characterized in that the material of the clutch element has a coefficient of friction greater than 0.25 against a steel material of the alternator pulley. 6. A serpentine band system according to claim 5, characterized in that the material of the clutch element has a coefficient of friction of between 0.30 and 0.40 against the steel material of the alternator pulley. A coil strip system according to claim 1, characterized in that the resilient spring element and the unidirectional clutch member each comprise a rolled or coiled steel material and wherein the coils of the unidirectional clutch member have a radial thickness that is less than a radial thickness of the coils of the resilient spring element. 8. A serpentine band system according to claim 1, characterized in that the unidirectional clutch element comprises a coiled or coiled steel structure and a friction material carried by the rolled steel structure, the friction material having a coefficient of friction greater than that of the rolled steel structure. 9. A serpentine band system according to claim 8, characterized in that the friction material comprises a rubber-based material (or rubber). A serpentine band system according to claim 8, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and is joined at an opposite end thereof to the unidirectional clutch member, The friction material of the unidirectional clutch element is constructed and arranged to engage frictionally with the alternator pulley, to allow the resilient spring element to transmit the rotational movements driven from the alternator pulley to the bucket structure, the friction material is constructed and arranged to be in sliding relationship with the alternator pulley, to allow the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the engine is decelerated to a sufficient extent to set the torque between the alternator pulley and the structure of the bo to the default negative level. 11. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a rubber (or rubber) material. 12. A coil strip system according to claim 1, characterized in that the resilient spring element and the unidirectional clutch element are arranged in an axially superposed relation to each other. A coil strip system according to claim 12, characterized in that the resilient spring element and the unidirectional clutch element are connected in series with each other by an intermediate element generally tubular extending in axially overlapping relation with respect to to the resilient spring element and the unidirectional clutch element. A coil strip system according to claim 13, characterized in that the resilient spring element is generally disposed radially inwardly of the tubular element and wherein the unidirectional clutch member is generally disposed radially outwardly of the tubular element. , the resilient spring element is attached at one end thereof to the hub or center structure and at an opposite end thereof to the tubular element, the unidirectional clutch element is attached at one end thereof to the tubular element and has a portion thereof. from the opposite end thereof constructed and arranged to be in a friction clamping coupling with the alternator pulley, to allow the resilient spring element to resiliently engage the hub structure with the alternator pulley, the unidirectional clutch element is located in sliding surface relationship with the alternator pulley, to allow the structure The alternator shaft rotates at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the motor is decelerated to a sufficient length to set the torque between the alternator pulley and the cube structure at the predetermined negative level. A coil strip system according to claim 1, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and is attached at an opposite end thereof to the unidirectional clutch member, Unidirectional clutch element is spring driven radially outward to have a portion thereof arranged in frictional engagement with the alternator pulley, when the alternator pulley is in a static condition, the unidirectional clutch member has increased portions thereof moved radially outward in frictional attachment engagement with the alternator pulley when the alternator pulley is rotationally driven by the belt for drive the alternator shaft. 16. A coil strip system according to claim 15, characterized in that the resilient spring element and the unidirectional clutch member each comprise a rolled or coiled steel material, wherein the coils of the resilient spring element and the coils of the unidirectional clutch element are wound in the same direction with each other and wherein the resilient spring element contracts radially when it is resiliently coupled with the hub structure for rotation driven by the alternator pulley. 17. A coil strip system according to claim 15, characterized in that the resilient spring element and the unidirectional clutch member each comprise a rolled or coiled steel material and wherein the coils of the resilient spring element and the coils of the unidirectional clutch element are wound in an opposite direction to each other and wherein the resilient spring element expands radially when it is resiliently engaged with the hub structure for rotation driven by the alternator pulley. 18. A serpentine band system according to claim 1, characterized in that the alternator pulley is mounted for relative rotation with respect to the cube structure by means of a set or assembly of ball bearings and a bushing, the assembly of The ball bearing and the bushing are spaced axially along the axis of the shaft with each other. 19. A serpentine band system according to claim 18, characterized in that the ball bearing assembly is closer to the alternator assembly than the bushing. 20. A serpentine band system according to claim 18, characterized in that the bushing is closer to the alternator assembly than the ball bearing assembly. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a helical steel spring, wherein the unidirectional clutch element comprises a coiled or coiled steel structure and a friction material carried by the rolled steel structure, the friction material has a coefficient of friction greater than the coefficient of friction of the rolled steel structure and greater than the coefficient of friction of the steel coil spring. 22. A coil strip system according to claim 1, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and attached at an opposite end thereof to the unidirectional clutch member, the element Unidirectional clutch is built and arranged to frictionally mate with the alternator pulley, to allow the resilient spring element to transmit the rotational movements driven from the alternator pulley to the bucket structure, the friction material is constructed and arranged to be in sliding relation with the alternator pulley to allow the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley, when the speed of the output shaft of the engine is decelerated to a sufficient extent to establish the moment of Torque between the alternator pulley and the cube structure at a predetermined negative level finished. 23. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a round wire spring and wherein the unidirectional clutch element comprises a coiled or coiled steel structure and a friction material carried by the rolled steel structure, the friction material has a coefficient of friction greater than that for the rolled steel structure and wherein the connection between the resilient spring element and the unidirectional clutch element comprises a crimped portion of the steel structure wound in attachment coupling with a portion of the round wire spring. 24. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a fixed helical spring at one end thereof to the hub structure and attached at an opposite end thereof to the unidirectional clutch element. , the unidirectional clutch element comprises a rolled steel structure and a friction material carried by the rolled steel structure, the friction material has a coefficient of friction greater than that for the rolled steel structure, the unidirectional clutch element has a free end portion thereof driven to a coupling with an inner surface of the alternator pulley, the friction material in the free end portion of the unidirectional clutch member is constructed and arranged to engage frictionally with the alternator pulley when the The alternator pulley is initially driven by the belt and wherein enlarged portions of the unidirectional clutch member extending away from the free end are engaged with the alternator pulley as the alternator pulley continues to be driven, until substantially all of the unidirectional clutch member is engaged with the pulley and the rotation of the alternator pulley is imparted by means of the connection to the resilient spring element, such that the resilient spring element resiliently couples the alternator pulley to the hub structure. 25. A coil strip system according to claim 3, characterized in that the spring ratio of the resilient spring element is greater than 0.011 m-Kg (1.0 inch-pounds) per degree of torsional deflection and wherein the ratio of Clutch element spring is less than 0.0011 m-Kg (0.1 inch-pounds) per degree of torsional deflection. 26. A serpentine band system according to claim 25, characterized in that the spring ratio of the resilient spring element is greater than one hundred times the spring ratio of the unidirectional clutch member. 27. A coil strip system according to claim 1, characterized in that the resilient element comprises a rubber spring that is compressed in so far as it couples the alternator pulley with the hub structure. 28. A coil strip system according to claim 1, characterized in that the resilient element comprises a rubber (or rubber) spring that is subjected to shear stress while resiliently coupling the alternator pulley with the bucket structure. . 29. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a pair of flat wire torsion springs arranged in parallel to each other, the flat wire torsion springs resiliently engage the pulley of the wire. alternator with the cube structure in a torsionally balanced manner. 30. A coil strip system according to claim 1, characterized in that the resilient spring element comprises a spring selected from a group comprising a coiled, helical, twisted wire torsion spring, an overlapping coiled torsion spring. axially, of round wire, a coiled, helical, twisted wire torsion spring or an axially superimposed spiral torsion spring of flat wire. 31. A serpentine band system according to claim 1, characterized in that the alternator pulley is mounted on the hub structure by a needle bearing. 32. A serpentine band system according to claim 1, characterized in that the unidirectional clutch mechanism comprises a fork-shaped band having a central band portion wrapped in a circumferentially superposed relationship with two axially spaced fork portions. 33. A device for transmitting movement of a belt driven by an output shaft of a motor to a shaft of an auxiliary component to be driven, characterized in that it comprises: a cube structure constructed and arranged to be fixedly carried by the auxiliary shaft for its rotation with it around a tree axis; a pulley element mounted on the bucket structure and constructed and arranged to engage the belt and to be rotatably driven therewith and a unidirectional spring and clutch mechanism that couples the pulley element to the bucket structure, the mechanism of The unidirectional spring and clutch comprises a resilient spring element formed separately from and joined in series with a unidirectional clutch member, the resilient spring element is constructed and arranged to transmit the rotationally driven movements of the pulley element to the hub structure, such that the shaft is rotated in the same direction as the pulley, insofar as it has instantaneous relative resilient movement capacity in opposite directions with respect to the pulley during the driven rotational movement thereof, the unidirectional clutch element is constructed and arranged to allow the cube structure and from here the tree to turn at speeds greater than the rotational speed of the pulley when the speed of the driven pulley is decelerated to a predetermined extent. 34. A device according to claim 33, characterized in that the resilient spring element has a ratio of torsional spring greater than a ratio of torsional spring of the unidirectional clutch member. 35. A device according to claim 34, characterized in that the ratio of the torsion spring of the resilient spring element is more than ten times greater than the ratio of the torsion spring of the clutch element. 36. A device according to claim 33, characterized in that the unidirectional clutch member comprises a material having a coefficient of friction greater than a material of the resilient spring element. 37. A device according to claim 36, characterized in that the material of the clutch element has a coefficient of friction greater than 0.25 against a steel material of the pulley element. 38. A device according to claim 37, characterized in that the material of the unidirectional clutch element has a coefficient of friction of between 0.30 and 0.40 against the steel material of the pulley element. 39. A device according to claim 33, characterized in that the resilient spring element and the unidirectional clutch member each comprise a coiled or wound steel material and wherein the coils of the unidirectional clutch member have a radial thickness which is less than a radial thickness of the coils of the resilient spring element. 40. A device according to claim 33, characterized in that the unidirectional clutch element comprises a coiled or coiled steel structure and a friction material carried by the rolled steel structure, the friction material has a coefficient of friction greater than that for the rolled steel structure. 41. A device according to claim 40, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and attached at an opposite end thereof to the unidirectional clutch member, the element friction material. Unidirectional clutch is constructed and arranged to frictionally engage with the pulley, to allow the resilient spring element to transmit the rotational movements propelled from the pulley to the bucket structure, the friction material is constructed and arranged to be in sliding relation with the pulley to allow the pulley structure and hence the shaft to rotate at the greater speed of the rotational speed of the pulley when the speed of the pulley driven is decelerated to the predetermined extent. 42. A device according to claim 33, characterized in that the resilient spring element and the clutch element are arranged in axially superposed relation to each other. 43. A device according to claim 42, characterized in that the resilient spring element and the unidirectional clutch element are connected in series with each other by means of a generally tubular intermediate element extending in axially superposed relation to the spring element. resilient and the unidirectional clutch member, the resilient spring element is generally disposed radially inwardly of the tubular member, the unidirectional clutch member is generally disposed radially outwardly of the tubular element, the resilient spring element is attached at one end from it to the cube structure and at an opposite end thereof to the tubular element, the unidirectional clutch member is attached at one end thereof to the tubular element and has an end portion thereof constructed and arranged to be in clamping engagement by friction with the pulley, to allow the mueling element The resilient resiliently coupling the cube structure with the pulley, the unidirectional clutch element is in surface sliding relationship with the pulley, to allow the cube structure and hence the shaft to rotate at speed greater than the rotational speed of the pulley when the speed of the pulley is decelerated to the predetermined extent. 44. A device according to claim 33, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and attached at an opposite end thereof to the unidirectional clutch member, the unidirectional clutch element is driven by spring radially outward to have a portion thereof disposed in frictional engagement with the pulley when the pulley is in a static condition, the unidirectional clutch has increased portions thereof moved radially outwardly in frictionally engaging engagement with the pulley when the auxiliary shaft is rotationally rotated, thereby rotationally coupling the pulley to the resilient spring element and allowing the resilient spring element Resiliently transmit the rotational movements driven from the pulley to the cube structure. 45. A device according to claim 33, characterized in that the resilient spring element comprises a steel helical spring, wherein the unidirectional clutch element comprises a coiled or coiled steel structure and a friction material carried by the structure of Rolled or coiled steel, the friction material has a coefficient of friction greater than the coefficient of friction of the coiled or coiled steel structure and greater than the coefficient of friction for the steel coil spring. 46. A device according to claim 33, characterized in that the resilient spring element is fixed at one end thereof to the hub structure and attached at an opposite end thereof to the unidirectional clutch member, the unidirectional clutch element is constructed and arranged to engage frictionally with the pulley, to allow the resilient spring element to transmit the rotational movements driven from the pulley to the hub structure, the friction material is constructed and arranged to be in sliding relation with the pulley to allow that the hub rotates at a speed greater than the rotational speed of the pulley when the speed of the pulley is decelerated to the predetermined extent. 47. A device according to claim 33, characterized in that the resilient spring element comprises a helical spring fixed at one end thereof to the hub structure and connected at an opposite end thereof to the unidirectional clutch member, the Unidirectional clutch comprises a coiled or coiled steel structure and a friction material carried by the coiled or coiled steel structure, the friction material has a coefficient of friction greater than that for the coiled steel structure, the unidirectional clutch element has a free end portion thereof driven to a coupling with an inner surface of the pulley, the friction material at the free end portion of the unidirectional clutch member is constructed and arranged to engage frictionally with the pulley, when the pulley is driven initially by the band and where increased portions of the element of unidirectional clutch extending far from the free end are coupled with the pulley, as the pulley continues to be driven, until substantially all of the unidirectional clutch element is engaged with the pulley and the rotation of the pulley is imparted by the pulley. means of the connection to the resilient spring element, in such a way that the resilient spring element resiliently couples the pulley to the hub structure. 48. A device according to claim 33, characterized in that the resilient spring element comprises a spring selected from the group comprising a twisted coil spring coil spring, an axially superimposed spiral torsion spring of round wire, flat wire helical coil spring, a coil twisted spring that is axially superimposed on flat wire or a spring made of a rubber material. 49. A serpentine belt drive system for an automotive vehicle, characterized in that it comprises: an impeller assembly including an internal combustion engine having an output shaft with a drive pulley thereon, rotatable about an axis of the drive pulley, a sequence of driven assemblies each having a driven pulley rotatable about an axis parallel to the axis of the driving pulley and a serpentine belt mounted in cooperating relationship with the driving pulley and with the pulleys driven in a sequence corresponding to the sequence of driven mounts when related to the direction of movement of the belt, to cause the driven pulleys to rotate in response to the rotation of the driving pulley, the sequence of driven mounts includes an alternator assembly that includes an alternator shaft mounted for rotation about a shaft of the shaft, a cube structure fixedly borne by the alternator shaft for rotation therewith around the shaft axis and a unidirectional spring and clutch mechanism that couples the alternator pulley with the structure of cube, the unidirectional spring and clutch mechanism comprises a portion of resilient spring dis put in series with a unidirectional clutch portion, the resilient spring portion has a torsional spring proportion at least ten times greater than a torsional spring ratio of the unidirectional clutch portion, the resilient spring portion is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the serpentine belt to the cube structure, in such a way that the alternator shaft is rotated in the same direction as the alternator pulley, while it has the capacity of resilient movements relative instantaneous in opposite directions with respect to the alternator pulley during the rotational movement thereof, the unidirectional clutch portion is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the speed rotation of the alternator pulley when the output speed d the engine is decelerated to a sufficient extent to establish the torque between the alternator pulley and the hub structure at a predetermined negative level. 50. A serpentine band system according to claim 49, characterized in that the resilient spring portion and the unidirectional clutch portion are formed separately and joined together. 51. A coil strip system according to claim 49, characterized in that the resilient spring element and the unidirectional clutch member each comprise coiled steel and wherein the unidirectional clutch portion comprises a friction improving surface disposed on the same. 52. A serpentine band system according to claim 51, characterized in that the friction improving surface comprises a rubber (or rubber) based material. 53. A coil strip system according to claim 52, characterized in that the rubber-based material of the friction-improving surface is constructed and arranged to frictionally mate with the alternator pulley, to allow the spring portion Resilient is resiliently coupled between the alternator pulley and the bucket structure, the rubber-based material of the friction improving surface is constructed and arranged to be in sliding relation with the alternator pulley, to allow the bucket structure and hence the alternator shaft rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the motor is decelerated to sufficient extent to establish the torque between the alternator pulley and the structure from cube to the default negative level. 54. A drive system (impeller or propulsion) of coil band for an automotive vehicle, characterized in that it comprises: an impeller (or drive) assembly that includes an internal combustion engine having an output shaft with a drive pulley about it, rotatable about an axis of the driving pulley, a sequence of driven assemblies each having a driven pulley rotating about an axis parallel to the axis of the driving pulley and a serpentine belt mounted in cooperating relationship with the driving pulley and with the pulleys driven in a sequence corresponding to the sequence of driven mounts when related to the direction of movement of the belt, to cause the driven pulleys to rotate in response to the rotation of the driving pulley, the sequence of driven mounts includes an alternator assembly including an alternator shaft mounted for rotation about a shaft axis, a hub structure steadily borne by the alternator shaft for rotation therewith around the shaft axis and a spring and clutch mechanism Unidirectional coupling alternator pulley with cube structure, spring and clutch unidirection mechanism Onal comprises a resilient spring portion arranged in series with a unidirectional clutch portion, the unidirectional clutch portion comprising a material having a coefficient of friction greater than the coefficient of friction of a material of the spring portion, the spring portion resilient is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the serpentine belt to the cube structure, in such a way that the alternator shaft is rotated in the same direction as the alternator pulley, while has the ability to instantaneous relative resilient movements in opposite directions with respect to the alternator pulley during the rotational movement driven thereof, the unidirectional clutch portion is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley when the output shaft speed of the motor is decelerated to a sufficient extent to set the torque between the alternator pulley and the hub structure at a predetermined negative level. 55. A serpentine band system according to claim 54, characterized in that the resilient spring portion and the unidirectional clutch portion are formed separately and joined together. 56. A serpentine belt drive system for an automotive vehicle, characterized in that it comprises: an impeller assembly that includes an internal combustion engine having an output shaft with a drive pulley thereon, rotatable about an axis of the drive pulley, a sequence of driven mounts each having a pulley driven rotating about an axis parallel to the axis of the driving pulley and a serpentine belt mounted in cooperating relationship with the driving pulley and with the pulleys driven in a sequence that corresponds to the sequence of driven assemblies, when related to the direction of movement of the belt, to cause the driven pulleys to rotate in response to the rotation of the driving pulley, the sequence of driven assemblies includes an alternator assembly that includes a alternator shaft mounted for rotation about a shaft of the shaft, a cube structure fixedly front by the alternator shaft for rotation therewith around the shaft axis and a unidirectional spring and clutch mechanism that couples the alternator pulley to the hub structure, the unidirectional spring and clutch mechanism comprises a resilient spring portion disposed In series with a unidirectional clutch portion, the unidirectional clutch member is spring driven radially outward to have a portion thereof disposed in frictional engagement with the alternator pulley when the alternator pulley is in a static condition, the unidirectional clutch has increased portions thereof moved radially outward in frictionally fastening engagement with the alternator pulley, when the alternator pulley is rotated by the belt to drive the alternator shaft, the resilient spring portion is constructed and arranged to transmit the rotational movements driven from the alternator pulley by the serpentine belt to the hub structure, such that the alternator shaft is rotated in the same direction as the alternator pulley, while having the capacity of instantaneous relative resilient movements in opposite directions with respect to the alternator pulley during the rotational movement driven thereof, the unidirectional clutch portion is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the rotational speed of the po read from the alternator when the engine output shaft speed is decelerated to a sufficient extent to set the torque between the alternator pulley and the hub structure at a predetermined negative level. 57. A serpentine band system according to claim 49, characterized in that the resilient spring portion and the unidirectional clutch portion are formed separately and joined together. SUMMARY OF THE INVENTION A coil strip drive (impeller or propulsion) system (18) is described for an automotive vehicle comprising a drive or impeller (or drive) assembly or assembly that includes a motor (10) of internal combustion having an output shaft (14) with a driving pulley (16) thereon rotatable about an axis of the driving pulley. A sequence of driven assemblies each have a driven pulley rotating about an axis parallel to the axis of the driving pulley and a serpentine belt (20) mounted in cooperating relationship with the driving pulley (16) and with the pulleys driven in a sequence that corresponds to the sequence of the driven mounts when they are related to the direction of movement of the belt, to cause the driven pulleys to rotate in response to the rotation of the driven pulley. The sequence of driven assemblies includes an alternator assembly (26) that includes a shaft (36) of the alternator, mounted for rotation about a shaft axis. A cube structure (52) is steadily carried by the shaft (36) of the alternator for rotation therewith around the axis of the shaft. A unidirectional spring and clutch mechanism engages the pulley (26) of the alternator with the cube structure. The mechanism (72) of unidirectional spring and clutch comprises a resilient spring element (74) formed separately and joined in series with a unidirectional clutch element (76). The resilient spring element (74) is constructed and arranged to transmit the rotational movements driven from the pulley (26) of the alternator by the serpentine strip (20) to the cube structure (52), such that the shaft ( 36) of the alternator is rotated in the same direction as the pulley (26) of the alternator, as long as it has instantaneous relative resilient movement capacity in opposite directions with respect to the alternator pulley during the rotational movement thereof. The unidirectional clutch element (76) is constructed and arranged to allow the cube structure and hence the alternator shaft to rotate at a speed greater than the rotational speed of the alternator pulley, when the alternator output shaft speed is decelerated to a sufficient extent to establish the torque between the pulley (26) of the alternator and the cube structure (52) at the predetermined negative level.