Abstract:
The axial displacement of the clutch retainer  28  of the roller clutch  10  is prevented. And, part of the clutch retainer  28  is prevented from rubbing the portion which rotates together with the follower pulley  7  to suppress the heat generation during overrun. Accordingly, grease degradation is prevented and durability and reliability are improved. Bevel is formed on the inner periphery of the outer clutch-race  25  of the roller clutch  10  and on the outer periphery of rollers  26  at an axial end thereof. Accordingly, the circumferential location of the rollers  26  is properly maintained and the installation of the outer clutch-race  25  on the outer diameter side of the rollers  26  and so the assembling process thereof become easy.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to improvements to a pulley apparatus with a built-in roller clutch that is used in the drive of auxiliary machinery of an engine, for use in such as the follower pulley fixed to the end of the rotating shaft of the alternator or automobile generator, or the drive pulley fixed to the end of an automobile crankshaft, and to the assembly method thereof.  
         BACKGROUND TECHNOLOGY  
         [0002]    An alternator is used as the drive source for driving the engine of an automobile and performs the necessary power generation for the automobile. The construction of such alternator was disclosed, for example, in Japanese patent publication No. Tokukai Hei 7-139550. FIG. 1 shows the alternator  1  described in that disclosure. A pair of rolling bearings  4  supports a rotating shaft  3  inside a housing  2  such that it rotates freely. A rotor  5  and a commutator  6  are located in the middle section of this rotating shaft  3 . Also, there is a follower pulley  7  fixed to one end (right end in FIG. 1) of this rotating shaft  3  in the section that protrudes out from the housing  2 . When assembled in an engine, an endless belt runs around this follower pulley  7  such that the rotating shaft  3  can be rotated and driven freely by the crankshaft of the engine.  
           [0003]    Conventionally, a pulley that was simply fixed to the rotating shaft  3  was used as this follower pulley  7 . However, recently, various kinds of pulley apparatuses with built-in one-way clutches have been proposed, and some have been used where in cases where there is a tendency for the running speed of the endless belt to be constant or to increase, power is transmitted freely to the rotating shaft from the endless belt, and in the case where there is a tendency for the running speed of the endless belt to decrease, the follower pulley rotates freely relative to the rotating shaft. For example, pulley apparatuses with built-in one-way clutches, having the functions described above, have been disclosed in Japanese patent publications Nos. Tokukai Hei 10-213207, 10-285873, 11-22753, and 11-63026. Moreover, the use of a roller clutch as the one-way clutch has also been known, such as described in each of the aforementioned disclosures.  
           [0004]    FIGS.  2  to  6  show a previously known pulley apparatus with built-in roller clutch, such as described in these disclosures. This pulley apparatus with built-in roller clutch has a rotating member (or called a shaft member), or more specifically a sleeve  8 , that fits around the outside of the rotating shaft  3  of the alternator  1  (see FIG. 1). Also, there is a pulley member, or in other words a follower pulley  7  located around this sleeve  8 , such that it is concentric with the sleeve  8 . Moreover, there is a pair of ball bearings  9   a ,  9   b  and a roller clutch  10  located in the space between the outer peripheral surface of the sleeve  8  and the inner peripheral surface of the follower pulley  7 .  
           [0005]    The sleeve  8  is formed generally into a substantially cylindrical shape and is fixed to the end of the rotating shaft  3  of the alternator  1  such that it rotates together with the rotating shaft  3 . As shown in the example in the figure, in order to do this, a screw hole section  11  is formed around the inner peripheral surface in the middle section of the sleeve  8 , and this screw hole section  11  is screwed together with a male screw section that is formed around the outer peripheral surface on the tip end of the rotating shaft  3 . Also, a fitting hole section  12 , having a hexagonal cross section, is formed on the inner peripheral surface on the tip end (left end in FIG. 2) of the sleeve  8  such that the tip end of a tool such as a hexagonal wrench can fit into this fitting hole section  12 . Furthermore, the inner peripheral surface of the base end (right end in FIG. 2) of the sleeve  8  is a circular hole section  13  that freely fits tightly around the tip end of the rotating shaft  3  at a location closer to its middle section without lost motion. It is also possible to use other construction such as a spline joint, non-circular joint, or key joint so that the sleeve  8  does not rotate relative to the rotating shaft  3 . Also, the center section of the outer peripheral surface of the sleeve  8  is a large-diameter section  14  that has a larger diameter than other sections.  
           [0006]    On the other hand, the outer peripheral surface on the tip-end half of the follower pulley  7  is formed with a wave-shaped cross section in the width direction such that part of an endless belt, called Poly V-belt, can run around it. Also, a roller clutch  10  is located in the middle section in the axial direction of the space between the outer peripheral surface of the sleeve  8  and the inner peripheral surface of the follower pulley  7 , and ball bearings  9   a ,  9   b  are located on both ends in the axial direction of this space such that they hold the roller clutch  10  on both sides in the axial direction.  
           [0007]    The ball bearings  9   a ,  9   b  support radial loads and axial loads that are applied to the follower pulley  7  such that the follower pulley  7  can rotate freely with respect to the sleeve  8 . Each of the ball bearings  9   a ,  9   b  comprises: an outer race  16  having an outer-raceway  15  of the deep-groove type formed around its inner peripheral surface; an inner race  18  having an inner-raceway  17  of the deep-grooved type formed around its outer peripheral surface; and a plurality of balls  19  located between the outer-raceway  15  and the inner-raceway  17 , such that they can rotate freely. Also, the outer race  16  is fitted and fastened around the inner peripheral surface on both ends of the follower pulley  7 , and the inner race  18  is fitted and fastened around the outer peripheral surface on both ends of the sleeve  8 . Moreover, in this state, one surface in the axial direction of each inner race  18  comes in contact with the respective end surface (stepped surface) in the axial direction of the large-diameter section  14 . Furthermore, seal rings  20  are located between the inner peripheral surface around both ends of the outer races  16  and the outer peripheral surface around both ends of the inner races  18  to cover the openings on both ends of the space where the balls  19  are located.  
           [0008]    The roller clutch  10  transmits rotating force between the follower pulley  7  and sleeve  8  only when the follower pulley  7  tends to rotate in a specified direction with respect to the sleeve  8 . In order to construct this kind of roller clutch  10 , an inner clutch-race  21  is tightly fitted and fastened around the large-diameter section  14  of the sleeve  8 . This inner clutch-race  21  is formed into a generally circular shape by performing plastic working, such as pressing steel plate like carburized steel, and a cam surface  22  is formed around its outer peripheral surface. In other words, the cam surface  22  can be formed around the outer peripheral surface by forming a plurality of concave sections  23 , called ramp sections, around the outer peripheral surface of the inner clutch-race  21  such that they are uniformly spaced around in the circumferential direction as shown in FIGS. 3 and 5. In the example shown in the figures, a tapered concave beveled section  24  is formed around one end (left end in FIG. 2) around the inner peripheral surface of the inner clutch-race  21 , and this beveled section  24  functions as a guide surface for when pressure fitting the inner clutch-race  21  around the outer peripheral surface of the large-diameter section  14 .  
           [0009]    On the other hand, an outer clutch-race  25  is tightly fitted and fixed in the middle section of the inside peripheral surface of the follower pulley  7 , and at least the middle section in the axial direction of the inner peripheral surface of the outer clutch-race  25  that comes in direct contact with a roller  26  (described below) is a simple cylindrical surface. This kind of outer clutch-race  25  is also formed into a generally cylindrical shape by plastic working e.g. pressing steel plate like carburized steel plate, and inward facing flange sections  27   a ,  27   b  are formed on both ends in the axial direction of the outer clutch-race  25 . Of the two flange sections  27   a ,  27   b , the flange sections  27   a  (left section in FIG. 2) is formed in advance when making the outer clutch-race  25 , so it has the same thickness as that of the cylindrical portion of the outer clutch-race  25 . On the other hand, the flange section  27   b  (right section in FIG. 2) is formed after the roller  26  and clutch retainer  28  (described below) have been assembled on the inside in the radial direction of the outer clutch-race  25 , so it is thin in material thickness.  
           [0010]    Moreover, a clutch retainer  28  is fit around the outside of the inner clutch-race  21  such that it is impossible for it to rotate with respect to the inner clutch-race  21 . A plurality of rollers  26 , which together with the inner clutch-race  21  and the outer clutch-race  25  form the roller clutch  10 , are held by the clutch retainer  28  such that they can freely roll and also move a little in the circumferential direction. This clutch retainer  28  is made of synthetic resin or plastic (for example, a synthetic resin such as polyamide 66, polyamide 46 or polyphenylene sulfide that is mixed with about 20% glass fibers) and is formed generally into a cage-like cylindrical shape, and as partly shown in FIG. 4, this clutch retainer  28  comprises a pair of ring-shaped rim sections  29 , and a plurality of column sections  30  that connect these rim sections  29 .  
           [0011]    The sections that are surrounded on four sides by the inside surfaces of the rim sections  29  and the surfaces in the circumferential direction of the column sections  30  form pockets  31  for holding the rollers  26 , respectively, such that they can freely roll and also move a little in the circumferential direction. Also, as shown in FIG. 5, protrusions  32  are formed at a plurality of locations on the inner peripheral surface of the rim sections  29  while concave sections  23  are formed on the outer peripheral surface of the inner clutch-race  21 , and the protrusions  32  are fitted with the concave sections  23 , so that the clutch retainer  28  is attached such that it cannot rotate with respect to the inner clutch-race  21 .  
           [0012]    Moreover, a substantially cylindrical space is formed between the outer peripheral surface of the cam surface  22  and the inner peripheral surface (cylindrical surface) in the middle section of the outer clutch-race  25 . As shown in FIG. 6, springs  33  are attached to one of the sides in the circumferential direction of the column sections  30  of the clutch retainer  28 , respectively. These springs  33  that are attached to each of the column sections  30  elastically press the rollers  26 , that are held in the pockets  31 , in the same circumferential direction of the clutch retainer  28  toward the section having a narrow width in the radial direction (toward the right, or in the clockwise direction of FIG. 5), respectively. In the example shown in the figure, flat springs made of spring steel plate and bent on both ends in a substantially hook shape are used as the springs  33 , however it is also possible to use synthetic resin springs that are formed together in a single piece with the clutch retainer  28 .  
           [0013]    Also, as to the flange sections  27   a ,  27   b  of the outer clutch-race  25 , both of the ends in the axial direction of the clutch retainer  28  come very close to and face the inside surfaces of these flange sections  27   a ,  27   b , and this prevents the clutch retainer  28  from moving in the axial direction. However, instead of this construction, another construction for preventing the clutch retainer from moving in the axial direction has been known, in which a plurality of stepped sections are formed around the outer peripheral surface of a shaft member such as a sleeve to fit with parts of the clutch retainer, such as disclosed in Japanese patent publications No. Tokukai Hei 11-22753, No. Tokukai 2001-165201, etc.  
           [0014]    When using a pulley apparatus with built-in roller clutch that is constructed as described above and there is a tendency for the follower pulley  7  and sleeve  8  to relatively rotate to a specified direction, or in other words, when the follower pulley  7  tends to rotate relative to the sleeve  8  in the direction that the springs  33  push the rollers  26  (to the right or clockwise in FIG. 5), the rollers  26  bite into the sections having a narrow width in the radial direction in the substantially cylindrical space. Also, the follower pulley  7  cannot rotate relative to the sleeve  8  (this is called locked state). On the other hand, when the follower pulley  7  and sleeve  8  rotate in a direction opposite to the specified direction, or in other words, when the follower pulley  7  tends to rotate relative to the sleeve  8  in the direction (to the left or counterclockwise direction in FIG. 5) opposite the direction that the springs  33  push the rollers  26 , the rollers  26  move against the elastic force of the springs  33  toward the sections having a large width in the radial direction in the substantially cylindrical space, and the follower pulley  7  can rotate freely relative to the sleeve  8  (this is called overrun state).  
           [0015]    There are the following two reasons for using a pulley apparatus with built-in roller clutch constructed as described above in an alternator. The first reason is to increase the life of the endless belt. For example, when the drive engine is a diesel engine or direct-injection gasoline engine, there are large changes in rotation angle speed of the crankshaft when rotating at low rpm such as during idling. As a result, the running speed of the endless belt that runs around the follower pulley also changes small. On the other hand, rotation of the rotating shaft  3  of the alternator that is rotated and driven by the endless belt via the follower pulley does not change so suddenly due to the inertial mass of the rotating shaft  3  and the rotor etc. fixed to the rotating shaft  3 . Therefore, when the follower pulley is simply fixed with respect to the rotating shaft, there is a tendency for friction to occur in both directions between the endless belt and follower pulley due to changes in the rotation angle speed of the crankshaft. As a result, stress is applied repeatedly in differing directions on the endless belt that rubs against the follower pulley, which makes it easy for slipping to occur between the endless belt and the follower pulley, or becomes the cause of decreased life of the endless belt.  
           [0016]    Therefore, by using the pulley apparatus with built-in roller clutch described above as the follower pulley, when there is a tendency for the running speed of the endless belt to be fixed or to increase, the rotation force is freely transmitted from the follower pulley to the rotating shaft  3 , and conversely, when there is a tendency for the running speed of the endless belt to decrease, the follower pulley rotates freely with respect to the rotating shaft. In other words, when there is a tendency for the running speed of the endless belt to decrease, the rotation angle speed of the follower pulley becomes slower than the rotation angle speed of the rotating shaft, so as to prevent strong rubbing from occurring at the area of contact between the endless belt and the follower pulley. In this way, the direction of the stress that acts on the section of rubbing between the endless belt and the follower pulley becomes constant, and it is possible to prevent slipping between the endless belt and the follower pulley, or to prevent a decrease in the life of the endless belt.  
           [0017]    The second reason is to improve the power generating efficiency of the alternator. The drive engine of the automobile rotates and drives the rotating shaft  3 , to which the alternator rotor is fixed, by way of the endless belt and follower pulley. When using a fixed type follower pulley and the rpm of the drive engine decreases suddenly, the rpm of the rotor also decreases suddenly, as well as does the amount of power generated by the alternator. However, when using a pulley apparatus with built-in roller clutch as described above as the follower pulley of the alternator, the rpm of the rotor decreases gradually due to inertial forces and power generation continues during this time, even though the rpm of the drive engine decreases suddenly. As a result, it is possible to more efficiently use the kinetic energy of the rotating shaft and rotor and to increase the amount of power generated by the alternator more than when using a fixed-type follower pulley.  
           [0018]    The explanation above is made for the case of when the pulley apparatus with built-in roller clutch was located on the side of the follower pulley, however, similar function and effects can be obtained when a pulley apparatus with built-in roller clutch, having the same construction as described above, is located on the end of crankshaft on the drive side.  
           [0019]    In the aforementioned documents that describe a prior art pulley apparatus with built-in roller clutch, including the prior art construction described above, the construction is capable of maintaining the durability and reliability of the pulley apparatus with built-in roller clutch, however there was nothing particularly mentioned about a method for more efficiently assembling this pulley apparatus with built-in roller clutch.  
           [0020]    Taking this into consideration, it is an object of this invention to provide a pulley apparatus with built-in roller clutch that is sufficiently durable and reliable, and an assembly method that makes it possible to easily assemble that pulley apparatus with built-in roller clutch.  
         DISCLOSURE OF THE INVENTION  
         [0021]    A feature of the pulley apparatus with built-in roller clutch and assembly method of this invention is that the pulley apparatus comprises a pulley member, a rotating shaft member (also called the shaft member), a roller clutch, a first ball bearing and a second ball bearing.  
           [0022]    Of these, the pulley member has a substantially cylindrical shape such that an endless belt can freely run around its outer peripheral surface.  
           [0023]    The rotating shaft member is located on the radially inner side of the pulley member such that it is concentric with the pulley member.  
           [0024]    The roller clutch is located between the inner peripheral surface in the middle in the axial direction of the pulley member and the outer peripheral surface in the middle in the axial direction of the rotating shaft member, and transmits rotating force on only one direction between the pulley and the rotating shaft, or in other words, becomes locked in one direction of rotation, and becomes unlocked in the other direction.  
           [0025]    This kind of roller clutch comprises an outer clutch-race-like section on the outer periphery, an inner clutch-race section on the inner periphery, a retainer, a plurality of rollers, a plurality of springs, a falling-prevention means, a fitting section and fitted section.  
           [0026]    Of these, the outer clutch-race-like section is located on the inner periphery in the middle section in the axial direction of the pulley member.  
           [0027]    Also, the inner clutch-race-like section is located on the outer periphery in the middle section in the axial direction of the rotating shaft member, and the outer peripheral surface of this inner clutch-race-like section is formed such that it is undulated around the circumferential direction, and this becomes a cam section or cam surface.  
           [0028]    The retainer is located between the outer peripheral surface of the inner clutch-race-like section and the inner peripheral surface of the outer clutch-race-like section, and comprises a plurality of pockets.  
           [0029]    The rollers are held in the retainer pockets such that they can roll and move freely in the circumferential direction of the retainer.  
           [0030]    The springs are located between the rollers and the retainer, in other words, they fit in the retainer and push the rollers in the same circumferential direction with respect to the retainer.  
           [0031]    The falling-prevention means is located in part of the retainer, and prevents the rollers that are held in the pockets from coming out of the pockets and dropping inside in the radial direction of the retainer.  
           [0032]    Of the fitting and fitted sections, the fitting section is located on the inner peripheral surface on the retainer, and by fitting with the fitted section located on the inner clutch-race-like section, it prevent the retainer from rotating relative to the inner clutch-race-like section.  
           [0033]    The first ball bearing is located between the inner peripheral section of one end in the axial direction of the pulley member, and the outer peripheral section of one end in the axial direction of the rotating shaft section, so as to support radial loads and axial loads that are applied between the pulley member and the rotating shaft member. The outer diameter section of the first ball bearing is located on the inner peripheral section of one end in the axial direction of the pulley member, and a first outer-raceway is formed around the inner peripheral surface of this outer diameter section. Moreover, the inner diameter section of the first ball bearing is located on the outer peripheral section of one end in the axial direction of rotating shaft member, and a first inner-raceway is formed around the outer peripheral surface of this inner diameter section. Furthermore, a plurality of first balls is located between the first inner-raceway and first outer-raceway such that they can roll freely.  
           [0034]    The second ball bearing is located between the inner peripheral surface of the other end in the axial direction of the pulley member and the outer peripheral surface of the other end in the axial direction of the rotating shaft member, so as to support radial loads and axial loads that are applied between the pulley member and rotating shaft member. This second ball bearing comprises an outer bearing race that fits around the inner peripheral surface on the other end in the axial direction of the pulley member and an inner bearing race that fits around the outer peripheral surface on the other end in the axial direction of the rotating shaft member, and a plurality of second balls, which are located between a second outer-raceway that is formed around the inner peripheral surface of the outer bearing race and a second inner-raceway that is formed around the outer peripheral surface of the inner bearing race, such that they can roll freely. Also, the shaft unit, or in other words, the rotating shaft unit comprises the rotating shaft member and the inner bearing race.  
           [0035]    Moreover, the rotating shaft unit has a plurality of stepped sections around its outer peripheral surface. By fitting two of these stepped sections with part of the retainer, displacement of the retainer in the axial direction is suppressed.  
           [0036]    The rollers of the roller clutch, and/or the roller raceway on the outer clutch-race-like section are beveled at one end thereof in the axial direction. For example, one end in the axial direction of the roller raceway on the outer clutch-race-like section is beveled. This beveled surface becomes a guide surface when bringing the rollers close to the outer clutch-race-like section in the axial direction, and then facing the rollers in the circumferential direction and moving them at the same time against the elastic force of the springs with the inner peripheral surface of the outer clutch-race-like section and the cam surface of the inner clutch-race-like section, in order to place the outer clutch-race-like section around the rollers.  
           [0037]    It is preferable that the total amount of bevel (width in the radial direction) of this beveled surface(s) be larger than the dimension needed for the rollers and outer clutch race-like section to overlap as seen from the axial direction. In other words, when the rollers and outer clutch-race-like section are seen in the axial direction in a state where the retainer and outer clutch-race-like section are arranged such that they are concentric, and where the phase in the circumferential direction is specified (state where together with bringing the part of the rolling surface of the rollers held in the retainer in contact with the inner peripheral surface of the inner clutch-race-like section, the rollers are pressed in the circumferential direction by the springs), the total amount of the bevel of the end in the axial direction of the rollers and the bevel of the end of roller raceway on the outer clutch-race-like section is greater than the dimension of overlap of the rollers and outer clutch-race-like section.  
           [0038]    Furthermore, the assembly method for assembling the pulley apparatus with built-in roller clutch according to a feature of this invention is a method for assembling the pulley apparatus with built-in roller clutch described above, and first, the rollers are placed and held in the respective pockets of the roller clutch retainer, then when these rollers are pressed to one side in the circumferential direction of the pockets by the springs, the rollers together with the retainer are placed around the radially outer side of the inner clutch-race-like section to form an assembled unit.  
           [0039]    Next, in order to assemble the outer clutch-race-like section of the roller clutch radially around the outside of the rollers and springs held by the retainer, the end of the outer clutch-race-like section is pressed radially over the outside of the rollers using the aforementioned beveled surface as a guide surface, or in other words, the outer clutch-race-like section is fitted onto or radially around the outside of the rollers held by the retainer by using the beveled surface, and the rollers are faced toward the cam surface formed around the outer peripheral surface of the inner clutch-race-like section and pressed inward in the radial direction by the inner peripheral surface of the outer clutch-race-like section. By fitting the rollers with the cam surface, the rollers are all moved at the same time in the circumferential direction against the elastic force of the springs, and the rollers are moved to a specified position in the circumferential direction between the inner peripheral surface of the outer clutch-race-like section and the outer peripheral surface of the inner clutch-race-like section, to form the aforementioned roller clutch.  
           [0040]    After this roller clutch has been assembled between the inner peripheral surface in the middle section in the axial direction of the pulley member and the outer peripheral surface in the middle section in the axial direction of the rotating shaft member, the second ball bearing is assembled between the inner peripheral surface of the other end in the axial direction of the pulley member and the outer peripheral surface of the other end in the axial direction of the rotating shaft member.  
           [0041]    Before assembling the second ball bearing, the first ball bearing is assembled between the inner peripheral section of one end in the axial direction of the pulley member and the outer peripheral section of one end in the axial direction of the rotating shaft member. The first ball bearing may be assembled before or after assembling the roller clutch.  
           [0042]    The work of securing the second ball bearing that is assembled in the section between the inner peripheral surface of the other end in the axial direction of the pulley member and the outer peripheral surface of the other end in the axial direction of the rotating shaft member is performed by a method such as pressure fitting, crimping, welding or using adhesive.  
           [0043]    In the case of the assembly method for assembling the pulley apparatus with built-in roller clutch according to another feature of this invention, after the aforementioned unit has been assembled, a jig is temporarily installed around the assembly to press the plurality of rollers of the assembly in the radially inward direction. Then, with the rollers pressed with this jig in the radial direction of the assembled unit and the springs simultaneously compressed by this jig, the outer diameter section of the roller clutch is assembled around this assembly, after which the second ball bearing is installed.  
           [0044]    With the pulley apparatus with built-in roller clutch and assembly method of this invention, it is possible to maintain sufficient durability and reliability of the pulley apparatus, as well as make it possible to perform assembly more easily.  
           [0045]    First, the function and effect that makes it possible to maintain sufficient durability and reliability is obtained by suppressing displacement of the retainer in the axial direction by fitting part of the retainer with a plurality of stepped sections formed around on the outer peripheral surface of the rotating shaft unit. In other words, since displacement of the retainer in the axial direction is suppressed by engagement between part of the retainer and the aforementioned stepped sections, the end surface in the axial direction of this retainer never comes in contact with any part of the outer clutch race and other parts that rotate together with the pulley member.  
           [0046]    The retainer is assembled such that it is prevented from rotating relative to the inner clutch-race-like section that is fastened around the outer peripheral surface of the rotating shaft member. Therefore, the pulley member and the retainer rotate relative to each other when the roller clutch is in the overrun state (when the connection is broken). As a results, if the end surface in the axial direction of the retainer comes in contact with any part of the outer clutch race or the parts that rotate together with the pulley member, the temperature of the roller clutch rises due to friction heat caused by rubbing of the contact area during overrun. Also, when this temperature rise becomes severe, the grease inside the roller clutch will degrade and cause the roller clutch to lose any protection against seizure, and thus it becomes difficult to obtain sufficient durability.  
           [0047]    On the other hand, in the case of the pulley apparatus with built-in roller clutch of this invention, there is no relative rotation of the retainer with respect to the rotating shaft unit during overrun while the retainer is prevented from displacement in the axial direction as mentioned above, so that strong rubbing between the surface of the retainer and the surface of the mating surface such as part of the outer clutch-race-like section is prevented during overrun, and thus it is possible to maintain durability by suppressing the occurrence of friction heat during overrun and preventing degradation of the grease. Moreover, since the retainer and inner clutch-race-like section are effectively prevented from moving in the axial direction, it is possible to prevent the rolling surface of the rollers held in the retainer from coming out in the axial direction from the cam surface formed around the outer peripheral surface of the inner clutch-race-like section. Therefore, it is possible to securely prevent edge loading from being applied to the rolling surfaces of the rollers as part of the rolling surfaces comes in contact with the edge of the end in the axial direction of the cam surface, and thus it is possible to prevent a decrease in the rolling contact fatigue life of these rolling surfaces and it is possible to improve the durability of these surfaces.  
           [0048]    Simplification of assembly is made possible by using the falling-prevention means, and by forming the beveled surface.  
           [0049]    First, the falling-prevention means prevents the rollers held in the pockets of the retainer from falling inside in the radial direction of retainer, so it is possible to more easily perform the work of inserting the inner clutch-race-like section radially on the inside of the rollers held in the pockets of the retainer beforehand. In other words, when there is no falling-prevention means, all or some of the rollers held in the pockets will greatly protrude or fall radially inside the retainer, making it difficult to insert the inner clutch-race-like section radially on the inside of the retainer. However, in the case of this invention, it is possible with the falling-prevention means to prevent the rollers from greatly protruding or falling radially inside the retainer when inserting the inner clutch race-like section, and thus it is possible to more easily perform the installation work. In other words, the retainer for the roller clutch of this invention is a single retainer that performs two positioning functions, or in other words, it prevents the rollers from greatly protruding or falling radially inside the retainer during assembly, and prevents the retainer itself from moving in the axial direction during operation, so that it is capable of simplifying the assembly work and maintaining the durability and reliability of the pulley apparatus.  
           [0050]    Second, the work of fitting the outer clutch-race-like section around the outside of the rollers that are arranged around the inner clutch-race-like section can be performed even more easily by a beveled surface that is formed on at least one of the end section in the axial direction of the rollers, and the end section of the roller raceway on the outer clutch-race-like section. In other words, this beveled surface acts as a guide surface when bringing the outer clutch-race-like section close to the rollers in the axial direction in order to place the outer clutch-race-like section around the rollers, and it makes it easier to perform the work of fitting the end of this outer clutch-race-like section radially around the outside of the rollers. That is, after assembling the retainer, rollers and springs around the inner clutch-race-like section to form an assembled unit, when fitting the outer clutch-race-like section radially around the outside of the rollers, the beveled surface allows for the outer clutch-race-like section to be fitted radially around the outside of the rollers.  
           [0051]    Moreover, when fitting the outer clutch-race-like section radially around the outside of the rollers in this way, the inner peripheral surface of this outer clutch-race-like section presses the rollers inward in the radial direction of the inner clutch-race-like section toward the cam surface formed around the outer peripheral surface of the inner clutch-race-like section. As a result, the cam surface moves the rollers at the same time in the circumferential direction against the elastic force of the springs. Furthermore, the rollers are moved to a specified position in the circumferential direction between the inner peripheral surface of the outer clutch-race-like section and the outer peripheral surface of the inner clutch-race-like section (for example, to the part of the concave section of the cam surface where the rollers come in contact with the inner peripheral surface of the outer clutch-race-like section and the outer peripheral surface of the inner clutch-race-like section at the same time), to form the roller clutch. Moving the rollers against the elastic force of the springs to a specified position in this way is performed for all of the rollers at the same time by the work of fitting the outer clutch-race-like section, so the work of assembling the roller clutch can be performed easily. Moving the rollers simultaneously by the cam surface in the circumferential direction against the elastic force of the springs in this way means that the rollers are moved to a specified position in the circumferential direction between the inner peripheral surface of the outer clutch-race-like section and the outer peripheral surface of the inner clutch-race-like section as described above. It is possible by moving the rollers to a specified position between both of the aforementioned peripheral surfaces in this way that rotating force is freely transmitted between the outer clutch-race-like section and inner clutch-race-like section.  
           [0052]    In short, in the case of this invention, the falling-prevention means prevents the rollers from greatly protruding or falling radially inside the retainer, and thus makes it easier to perform the work of inserting the inner clutch-race-like section radially on the inside of the rollers. Together with this, by forming a beveled surface, the inclined surfaces of the plurality of concave sections of the cam surface move the rollers in the circumferential direction of the inner clutch-race-like section as the end of the roller raceway of the outer clutch-race-like section is pressed over the outer diameter section of the rollers, so as to move the rollers to a specified position. Therefore, there is no need for troublesome work when assembling the rollers and springs, such as compressing each of the springs individually, and thus it is possible to assemble the pulley apparatus with built-in roller clutch simply and efficiently.  
           [0053]    To say again, in the case of this invention, through the function of the falling-prevention means that is formed on the retainer of the roller clutch, the rollers are kept from moving radially inside the retainer, and thus it becomes easier to insert the inner clutch-race-like section into the radially inner section of the retainer. Also, by using the beveled surface to fit the outer clutch-race-like section radially around the outside of the rollers, the springs are all compressed at the same time, and the rollers are all moved to their specified position at the same time. Therefore, the work of moving the rollers against the elastic force of the springs to a specified position, which up until now was very troublesome work to perform because of the plurality of rollers and springs, can be performed easily. In other words, in regards to the assembly of the rollers, springs and outer clutch-race-like section, the work of bringing the outer clutch-race-like section into contact with the rollers is also easy to perform, as well as is the work of simultaneously compressing the springs and moving the rollers to their specified position after they have been brought into contact.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0054]    [0054]FIG. 1 is a cross sectional view to show an example of the conventional alternator.  
         [0055]    [0055]FIG. 2 is a cross sectional view of a half of an example of the conventional structure of the pulley apparatus with built-in roller clutch.  
         [0056]    [0056]FIG. 3 is a perspective view of part of the inner clutch race.  
         [0057]    [0057]FIG. 4 is a perspective view of part of the clutch retainer.  
         [0058]    [0058]FIG. 5 is a side elevational view of part of the inner clutch race and the clutch retainer.  
         [0059]    [0059]FIG. 6 is a perspective view of an example of the spring mounted to a clutch retainer.  
         [0060]    [0060]FIG. 7 is a cross sectional view of a half of an example of the embodiment of the pulley apparatus with built-in roller clutch of the present invention.  
         [0061]    [0061]FIG. 8 is a cross sectional view of an example of the falling-prevention means to prevent the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0062]    [0062]FIG. 9 is a view to show a bevel formed on the inner periphery of the end of the outer clutch race wherein (A) is an enlarged perspective view of a portion and (B) is a cross sectional view taken along the line IX-IX in (A).  
         [0063]    [0063]FIG. 10 is a cross sectional view to show engagement between the outer clutch race and the bevel formed on the outer periphery at the and of the rollers.  
         [0064]    [0064]FIG. 11 is a view to show a state before pushing the inner clutch race on the radially inner side of the rollers, wherein the position relation between the inner clutch-race and the rollers is seen from the side of FIG. 7.  
         [0065]    [0065]FIG. 12 is a cross sectional brief view to show an example of the assembling process of the pulley apparatus with built-in roller clutch according to a first example of the embodiment of the present invention.  
         [0066]    [0066]FIG. 13 is a cross sectional view of a half of a second example of the embodiment of the pulley apparatus with built-in roller clutch according to the present invention.  
         [0067]    [0067]FIG. 14 is a cross sectional brief view of an example of the assembling process of the pulley apparatus with built-in roller clutch of a second example of the embodiment of the present invention.  
         [0068]    [0068]FIG. 15 is a cross sectional view of a half of a third example of the embodiment of the pulley apparatus with built-in roller clutch according to the present invention.  
         [0069]    [0069]FIG. 16 is a cross sectional view of a half of a fourth example of the embodiment of the pulley apparatus with built-in roller clutch according to the present invention.  
         [0070]    [0070]FIG. 17 is a cross sectional view of a half of a fifth example of the embodiment of the pulley apparatus with built-in roller clutch according to the present invention.  
         [0071]    [0071]FIG. 18 is a cross sectional view of a half of a sixth example of the embodiment of the pulley apparatus with built-in roller clutch according to the present invention.  
         [0072]    [0072]FIG. 19 is a cross sectional brief view of another twelve examples of the structure to prevent displacement in the axial direction of the clutch retainer.  
         [0073]    [0073]FIG. 20 is a cross sectional brief view of another thirteen examples of the structure to prevent displacement in the axial direction of the clutch retainer.  
         [0074]    [0074]FIG. 21 is a cross sectional brief view of another six examples of the structure to prevent displacement in the axial direction of the clutch retainer.  
         [0075]    [0075]FIG. 22 is a cross sectional brief view of another two examples of the structure to prevent displacement in the axial direction of the clutch retainer.  
         [0076]    [0076]FIG. 23 is a cross sectional brief view to show a second example of the falling-prevention means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0077]    [0077]FIG. 24 is a cross sectional brief view to show a third example of the falling-prevention means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0078]    [0078]FIG. 25 is a cross sectional view to show a fourth example of the means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer, where (A) is a cross sectional brief view, and (B) is a view taken from the lower side of (A) with the rollers removed.  
         [0079]    [0079]FIG. 26 is a cross sectional view to show a fifth example of the means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer, where (A) is a cross sectional brief view, and (B) is a cross sectional view taken along the line XXVI-XXVI in (A).  
         [0080]    [0080]FIG. 27 is a cross sectional view to show a sixth example of the falling-prevention means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0081]    [0081]FIG. 28 is a cross sectional brief view to show a seventh example of the falling-prevsntion means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0082]    [0082]FIG. 29 is a cross sectional brief view to show an eighth example of the falling-prevention means for preventing the rollers from falling off radially inward from the pockets of the clutch retainer.  
         [0083]    [0083]FIG. 30 is a side elevational brief view of a first example of the jig for use in working an embodiment of the present invention.  
         [0084]    [0084]FIG. 31 is a side elevational brief view of a second example of the jig for use in working an embodiment of the present invention to show both of operating and non-operating conditions.  
         [0085]    [0085]FIG. 32 is a side elevational brief view of a third example of the jig for use in working an embodiment of the present invention to show both of operating and non-operating conditions. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0086]    FIGS.  7  to  11  show a first example of the embodiment of the invention. A feature of this invention is that it prevents rubbing between the clutch retainer  28  and the sections that rotate together with the follower pulley  7  during the overrun state to suppress any temperature rise due to friction heat, and thus improves durability, and it simplifies the work of assembling the roller clutch  10  radially on the inside of the follower pulley  7 . The other construction and functions are substantially the same as those of the prior construction shown in FIGS.  2  to  6 , so the same reference numbers will be given to identical parts and any redundant explanation of will be omitted. This explanation will center mainly on the features of this invention and those parts that differ from the prior art construction.  
         [0087]    First, the construction of the part that suppresses displacement of the clutch retainer  28  in the axial direction in order to suppress a rise in temperature will be explained. This clutch retainer  28  is formed by injection molding of a synthetic resin having sufficient elasticity, and has a fitting brim section  34  in an inward facing flange shape that is formed all the way around or intermittently around the circumferential direction on one end in the axial direction (right end in FIG. 7). On the other hand, one or a plurality of fitting protrusions  35  that protrude inward in the radial direction are formed intermittently around in the circumferential direction of the other end in the axial direction of the clutch retainer  28 . The inner peripheral surface of the fitting protrusions  35  is inclined outward in the radial direction toward the axial tip end and act as inclined guide surfaces  36 . Also, stepped sections are formed on both ends in the axial direction of the inner clutch-race  21  of the roller clutch  10 . Displacement in the axial direction of the clutch retainer  28  is suppressed by fitting both end surfaces in the axial direction of the inner clutch-race  21  with the fitting brim section  34  and the fitting protrusions  35  at their mating surfaces.  
         [0088]    Next, FIG. 8 will be used to explain the falling-prevention means for preventing the rollers  26  from falling out of the pockets  31  of the clutch retainer  28  inward in the radial direction of the clutch retainer  28 . As shown in FIG. 8, the rollers  26  are held in the pockets  31  formed in the clutch retainer  28  such that they can roll freely and move freely in the circumferential direction of the clutch retainer  28 . Of the openings of the pockets  31 , the width W 31  in the circumferential direction of the opening on the inner diameter side of the clutch retainer  28  is smaller than the diameter D 26  of the rollers (W 31 &lt;D 26 ). Therefore, the rollers  26  cannot pass through the openings on the inner-diameter side, and thus the rollers  26  do not fall inward in the radial direction of the clutch retainer  28 .  
         [0089]    Next, FIGS.  9  to  11  will be used to explain the beveled surfaces that are formed on the radially inner edge section of one end in the axial direction of the outer clutch-race  25  and on the ends in the axial direction of the rollers  26  and that are used for installing the outer clutch-race  25  radially the outside of the rollers  26  that are held around the inner clutch-race  21  by the clutch retainer  28 . First, as shown in FIGS.  9 (A) and  9 (B), a beveled surface  38  is formed all the way around circumference of the radially inner edge section of one end in the axial direction of the outer clutch-race  25  so as to connect the inner peripheral surface of the outer clutch-race  25  with the end surface  37  in the axial direction of this outer clutch-race  25 . This beveled surface  38  forms bowl-shaped concave surface that is inclined outward in the radial direction from the inner peripheral surface of the outer clutch-race  25  toward the end surface  37 .  
         [0090]    Correspondingly, as shown in FIG. 10, beveled surfaces  39 , which are convex surfaces having a quarter arc shaped or partially cone shaped cross section, are formed on the ends in the axial direction of the rollers  26 .  
         [0091]    These beveled surfaces  38 ,  39  act as guide surfaces for placing the outer clutch-race  25  around the rollers  26 , or in other words, they act as guide surfaces for putting the rollers  26  radially on the inside of the outer clutch-race  25 , specifically when bringing the outer clutch-race  25  close to the rollers  26  in the axial direction and using the cam surface  22  to move the rollers  26  in the circumferential direction against the elastic force of the springs  33 . That is, when pressing the outer clutch-race  25  over the radially outer side of the rollers  26  in order to place the outer clutch-race  25  radially around the outside of the rollers  26 , it is possible because of these beveled surfaces  38 ,  39  to fit the outer clutch-race  25  radially around the outside of the rollers  26  without any interference between the outer peripheral edges in the axial direction of the rollers  26  and the inner peripheral edge of the end in the axial direction of the outer clutch-race  25 .  
         [0092]    Therefore, the amount of bevel of these beveled surfaces  38 ,  39 , or in other words, the total of the widths W 38 , W 39  in the radial direction of these beveled surfaces  38 ,  39 , is controlled by the relationship between the rollers  26  and the outer clutch-race  25 . That is, in the first step of the work of fitting the outer clutch-race  25 , the beveled end in the axial direction of the outer clutch-race  25  is placed around the mating ends of the rollers  26  that are held by the clutch retainer  28  around the outside of the inner clutch-race  21 . In this first step, the rollers  26  and inner clutch-race  21  are still offset in the axial direction. Also, these rollers  26  are pressed by the springs  33 , so that the phase in the circumferential direction is moved to the sections where the depths of the concave sections  23  of the cam surface  22  on the outer peripheral surface of the inner clutch-race  21  is shallow (sections where the space between the outer peripheral surface of the inner clutch-race  21  and inner peripheral surface of the outer clutch-race  25  is narrow).  
         [0093]    In this state, as shown in FIG. 11, part of each roller  26  is located further outward in the radial direction than the inner peripheral surface of the outer clutch-race  25 . Or in other words, part of the outer clutch-race  25  and part of each roller  26  overlap with each other in the radial direction, in other words when viewed in the axial direction. When the amount that these members  25 ,  26  overlap in this state is taken to be ‘δ’, then the total of the widths W 38 , W 39  in the radial direction of the beveled surfaces  38 ,  39  is greater than the amount of overlap ‘δ’ (W 38 +W 39 &gt;δ). When this relationship (W 38 +W 39 &gt;δ) is achieved, either one of the widths W 38 , W 39  can be zero ‘0’. By regulating the size of these beveled surfaces  38 ,  39  in this way, the outer clutch-race  25  can be freely radially fitted around the outside of the clutch retainer  28  and rollers  26  that were beforehand installed around the outer peripheral surface of the inner clutch-race  21 .  
         [0094]    The work of assembling the components of the pulley apparatus with built-in roller clutch of this example of the invention is performed, for example, as shown in FIGS.  12 (A) to  12 (F). First, as shown in FIG. 12(A), the springs  33  (see FIGS. 6 and 11) are mounted in the clutch retainer  28 , and the rollers  26  are held in the pockets  31  that are formed in the clutch retainer  28 . In this state, the springs  33  press the rollers  26  against one end in the circumferential direction of the pockets  31 . Also, in this state, the rollers  26  are prevented from falling into the inner-diameter side of the clutch retainer  28  by the falling-prevention means as shown in FIG. 8. The rollers  26 , springs  33  and clutch retainer  28  are installed radially around the outside of the inner clutch-race  21  as shown in FIG. 12(B). When doing this, the fitting protrusions  32  that are formed on the side of the clutch retainer  28  fits with the concave sections  23  formed on the inner clutch-race  21  to prevent relative rotation between the inner clutch-race  21  and clutch retainer  28  (see FIG. 11). Inserting the inner clutch-race  21  radially on the inner side of the clutch retainer  28  is performed from the side of the fitting protrusions  35  that are formed on the other end in the axial direction of the clutch retainer  28  (see FIG. 7). When performing the insertion, the fitting protrusions  35  are elastically deformed outward in the radial direction.  
         [0095]    After that, as shown in FIG. 12(C), the outer clutch-race  25  is installed radially around the outside of the rollers  26 . When installing the outer clutch-race  25 , first, one end in the axial direction of the outer clutch-race  25  is pressed over (fitted onto) the outer diameter side of the rollers  26 . When pressing the outer clutch-race  25  over the rollers  26 , the beveled surfaces  38 ,  39  that are formed on the end in the axial direction of the outer clutch-race  25  and on the corresponding end of the rollers  26  (see FIGS. 9 and 10) act as guide surfaces. Therefore, pressing the outer clutch-race  25  radially over the outside of the rollers  26  can be performed smoothly with no trouble.  
         [0096]    When starting the work of pressing (fitting) the outer clutch-race  25  in this way, the phase in the circumferential direction of the rollers  26  with respect to the inner clutch-race  21  is in the state as shown by the solid line in FIG. 11. In other words, the rollers  26  are located in the relatively shallow sections of the concave sections  23  of the cam surface  22  on the outer peripheral surface of the inner clutch-race  21 , and the rollers  26  are located relatively outward in the radial direction of the inner clutch-race  21  by that amount. As can be clearly seen from FIG. 11, which shows this state, when the phase in the circumferential direction of the rollers  26  with respect to the inner clutch-race  21  is in that state, it is not possible to perform the work of fitting the outer clutch-race  25 . The reason for that is, that in the section where the rollers  26  are located, the distance L between the inner peripheral surface of the outer clutch-race  25  and the cam surface  22  that is formed on the outer peripheral surface of the inner clutch-race  21  is less than the diameter D 26  of the rollers  26  (L&lt;D 26 ).  
         [0097]    However, as the outer clutch-race  25  is fitted radially around the outer diameter side of the rollers  26 , the rollers  26  are moved in the circumferential direction against the elastic force of the springs  33  due to the cam surface  22  that is formed around the outer peripheral surface of the inner clutch-race  21 . In other words, due to the interaction between the beveled surfaces  38 ,  39 , as the end section in the axial direction of the outer clutch-race  25  moves over radially the outside of the rollers  26 , the inner peripheral surface of the outer clutch-race  25  presses the rollers  26  against the outer peripheral surface of the inner clutch-race  21 . Therefore, the rollers  26  receive a counter action from the outer peripheral surface of the inner clutch-race  21 . Also, the rollers  26  are pressed in the orthogonal direction against the inclined surfaces of the concave sections  23  of the cam surface  22  formed around the outer peripheral surface of the inner clutch-race  21 . Of the orthogonal force, the partial force in the circumferential direction of the inner clutch-race  21  moves the rollers  26  against the elastic force of the springs  33 , as shown by the dashed line in FIG. 11, into a specified position in the circumferential direction between the inner peripheral surface of the outer clutch-race  25  and outer peripheral surface of the inner clutch-race  21 , or in other words, into the section where the space between both of these peripheral surfaces is equal to the diameter D 26  of the rollers  26 . In this state, the roller clutch  10  is completely assembled.  
         [0098]    As shown in FIG. 12(D), the roller clutch  10  that is assembled in this way is installed around the inner peripheral surface in the middle section in the axial direction of the follower pulley  7  by interference-fitting the outer clutch-race  25  on the inside of the follower pulley  7 . Then, as shown in FIG. 12(E), the inner clutch race  21  is interference-fitted around the outside of the sleeve  8  to install the inner clutch race  21  around the outer peripheral surface of the middle section in the axial direction of the sleeve  8 . In this state, the roller clutch  10  is assembled between the inner peripheral surface in the middle section of the follower pulley  7  and the outer peripheral surface in the middle section of the sleeve  8 .  
         [0099]    Finally, as shown in FIG. 12(F), the first and second ball bearings  9   a ,  9   b  are installed in the section between the inner peripheral surface of both end sections in the axial direction of the follower pulley  7  and the outer peripheral surface of both end sections of the sleeve  8  and located on both sides in the axial direction of roller clutch  10 . In this state, the pulley apparatus with built-in roller clutch as shown in FIG. 7 is completely assembled.  
         [0100]    The feature of the assembly method of this invention is in the process of assembling the outer clutch-race  25  around the outer diameter side of the clutch retainer  28 , rollers  26  and springs  33  that were assembled beforehand radially around the outside of the inner clutch-race  21  in order to assemble the roller clutch  10 . The other processes are not limited to the order shown in FIG. 12 and can be changed as appropriate. For example, it is possible to assemble clutch retainer  28 , rollers  26 , springs  33  and outer clutch-race  25  radially around the outside of the inner clutch-race  21  that has already been securely fitted and fastened beforehand radially around the outer peripheral surface of the middle section in the axial direction of the sleeve  8 . Furthermore, one of the pair of ball bearings  9   a ,  9   b  may be installed between the inner peripheral surface of the follower pulley  7  and the outer peripheral surface of the sleeve  8  before assembling the roller clutch  10 .  
         [0101]    Next, FIG. 13 shows a second example of the embodiment of the invention. In this example, there are an outer clutch race-like section  40  of the roller clutch  10  integrated into a single member with the follower pulley  7 , and an inner clutch-race-like section  41  integrated into a single member with the sleeve  8 .  
         [0102]    As shown in FIG. 14(A), in the case of assembling the construction of this exmple, after the rollers  26  and springs have been assembled in the clutch retainer  28 , these members are assembled radially around the outside of the inner clutch-race-like section  41  as shown in FIG. 14(B). Then, as shown in FIG. 14(C), the outer clutch-race-like section  40  is installed radially around the outside of the rollers  26  to form the roller clutch  10 , and then the pair of ball bearings  9   a ,  9   b  are installed on both sides of the roller clutch  10  as shown in FIG. 14(D).  
         [0103]    The construction and functions of the other parts are substantially the same as those in the first example described above, so any redundant drawings and explanations will are omitted.  
         [0104]    Next, FIGS.  15  to  18  show a third thru sixth example of the embodiment of the invention.  
         [0105]    First, in the case of the third example shown in FIG. 15, the outer clutch-race  25  is fitted and fastened to the inner peripheral surface in the middle section in the axial direction of the follower pulley  7 , and the inner clutch-race-like section  41  is integrally formed around the outer peripheral surface in the middle section in the axial direction of the sleeve  8 .  
         [0106]    Next, in the case of the fourth example shown in FIG. 16, the inner clutch race  21  is fitted and fastened onto the outer peripheral surface in the middle section in the axial direction of the sleeve  8 , and the outer clutch-race-like section  40  is integrally formed around the inner peripheral surface in the middle section in the axial direction of the follower pulley  7 .  
         [0107]    Next, in the case of the fifth example shown in FIG. 17, the sleeve  8  integrally has a member corresponding to the inner race of the first ball bearing  9   a , and the follower pulley  7  integrally has a member corresponding to the outer race.  
         [0108]    Furthermore, in the case of the sixth example shown in FIG. 18, the outer clutch-race-like section  40  of the roller clutch  10  is integrated with the follower pulley  7  while the inner clutch-race-like section  41  is integrated with the sleeve  8 , and further the sleeve  8  has integrally a member corresponding to the inner race of the first ball bearing  9   a  while the follower pulley  7  has integrally a member corresponding to the outer race.  
         [0109]    The construction and functions of the other parts of the third to sixth embodiments are substantially the same as those of the first and second embodiment described above and any redundant drawings or explanations are omitted.  
         [0110]    Next, FIGS.  19  to  21  are used to explain other examples of the construction of the part that suppresses displacement in the axial direction of the clutch retainer  28  by fitting with part of the clutch retainer  28  a plurality of stepped sections  53   a ,  53   b , which are formed around the outer peripheral surface of the rotating shaft unit  52  that is made by fastening or integrating the inner race  18  of at least one of the ball bearings  9   a ,  9   b  around the outside of the rotating shaft member  8 . The stepped sections that are formed around the outer peripheral surface of the rotating shaft unit  52  include, of course the protruding stepped sections that are formed directly on the outer peripheral surface of the rotating shaft unit  52  {for example, the stepped section  53   b  as shown in FIG. 19(A)}, as well as the side surfaces of the concave groove  55  that is formed around the outer peripheral surface of the rotating shaft member  8  {for example, surfaces  53   a ,  53   b  shown in FIG. 19(C)}, and the end surfaces in the axial direction of the inner clutch-race  21  (inner clutch-race-like section  41 ), which is fitted and fastened around the outside of the rotating shaft member  8 , and of the inner bearing races  18  of the ball bearings  9   a ,  9   b  {for example, surface  53   b  shown in FIG. 19(B)}.  
         [0111]    Of the construction that uses these stepped sections  53   a ,  53   b  for suppressing displacement in the axial direction of the clutch retainer  28 , FIGS.  19 (A) to  19 (L) show construction where a fitting section  54  that is bent inward in the radial direction from one end in the axial direction of the clutch retainer  28  is placed between a pair of stepped sections  53   a ,  53   b , FIGS.  20 (A) to  20 (M) show construction where both ends in the axial direction of the clutch retainer  28  (including a fitting section  54  that is bent inward in the radial direction from the ends) are placed between a pair of stepped sections  53   a ,  53   b , FIGS.  21 (A) to  21 (F) show construction where a pair of stepped sections  53   a ,  53   b  are located between a pair of fitting sections  54   a ,  54   b  that bend inward in the radial direction from both ends in the axial direction of the clutch retainer  28 , and FIGS.  22 (A) and  22 (B) show construction where stepped sections  53   a ,  53   b  are located between a pair of fitting sections  54   a ,  54   b  that are formed on one end in the axial direction of the clutch retainer  28  to protrude inward in the radial direction.  
         [0112]    Next, FIGS.  23  to  29  will be used to explain other examples of the construction of the falling-prevention means for preventing the rollers  26  that are held in the pockets  31  of the clutch retainer  28  from falling from the pockets  31  into the inner diameter side of the clutch retainer  28 .  
         [0113]    First, FIG. 23 shows construction where a spring  33  applies an elastic force on the roller  26  in the radial direction of the clutch retainer  28  and presses the roller  26  against the inclined surface  42  of the inner surface of the pocket  31 .  
         [0114]    [0114]FIG. 24 shows construction where protruding tabs  43   a ,  43   b  are formed on the opening section of the inner diameter side of the pocket  31  such that the distance between the tips of both of these tabs  43   a ,  43   b  is less than the diameter of the roller  26 .  
         [0115]    [0115]FIG. 25 shows construction where a filament-shaped wire  44  is located in the pocket  31  on the inner diameter side of the clutch retainer  28  such that it runs across in the axial direction of the pocket  31 , such that the distance between this wire  44  and the opposing surface of the pocket  31  is less than the diameter of the roller  26 .  
         [0116]    [0116]FIG. 26 shows construction where wire rings  45  are mounted to the inner peripheral surface on both ends of the clutch retainer  28  and protrusions  46  are formed on both ends of the roller  26  such that the interaction between the wire rings  45  and the protrusions  46  prevents the roller  26  from moving inward in the radial direction of the clutch retainer  28 .  
         [0117]    [0117]FIG. 27 shows construction where protrusions  46  are formed on the ends in the radial direction of the roller  26 , and the filament-shaped wires  47  are engaged with the protrusions  46  and embedded into the ends in the axial direction of the clutch retainer  28 .  
         [0118]    [0118]FIG. 28 shows construction where springs  48  are located between the wire rings  45  and protrusions  46  in the example shown in FIG. 26 such that they apply an elastic force on the roller  26  outward in the radial direction of the clutch retainer  28 .  
         [0119]    [0119]FIG. 29 shows construction where concave sections  49   a ,  49   b  are formed on the inner surface on both sides in the axial direction of the pockets  31  formed in the clutch retainer  28  such that both of the pointed ends in the axial direction of the roller  26  fit inside these concave sections  49   a ,  49   b.    
         [0120]    When performing the assembly method for the pulley apparatus with built-in roller clutch of this invention, before pressing the outer clutch-race-like section radially over the outside of the rollers, a jig  50 , such as shown in FIGS.  30  to  32 , is used to move the rollers, at the same time while pressing the springs, to a specified position in the circumferential direction of the retainer where the diameter of the circumscribed circle of the rollers is less than the inner diameter of the outer clutch-race-like section, such that the outer clutch-race-like section can be installed radially around the outside of the rollers.  
         [0121]    Of the jigs  50  that are used in this case, the jig  50  shown in FIG. 30 moves a plurality (three in the figure) of circular-arc shaped pressure pieces  51  in the radial direction by rods  56 . When fitting the outer clutch-race-like section over the rollers, the pressure pieces  51  press the rollers on their one half in the axial direction inward in the radial direction toward the inner clutch-race-like section, while at the same time the outer clutch-race-like section is fitted radially around the outside of the rollers from the other half in the axial direction. In this state, with the outer clutch-race-like section fitted over the rollers on the other half in the axial direction, the jig  50  is retracted (removed) and then the outer clutch-race-like section is fitted over the one half in the axial direction of the rollers.  
         [0122]    The jig  50  shown in FIGS.  31 (A) and  31 (B) has a circular-shaped holder  57  that supports the same number of pressure rods  58  as the rollers such that they can move freely in the radial direction. When fitting the outer clutch-race-like section over the rollers, the holder  57  is placed over one half in the axial direction of the rollers, and then by moving the pressure rods  58  inward in the radial direction from the state shown in FIG. 31(A) to the state shown in FIG. 31(B), it presses the one half in the axial direction of the rollers inward in the radial direction of the inner clutch-race-like section, while at the same time the outer clutch-race-like section is fitted radially around the outside of the rollers from the other half in the axial direction of the rollers. In this state, with the outer clutch-race-like section fitted over the rollers on the other half in the axial direction, the jig  50  is retracted (removed) and then the outer clutch-race-like section is fitted over the one half in the axial direction of the rollers.  
         [0123]    Furthermore, the jig  50  shown in FIGS.  32 (A) and  32 (B) is a flexible cord-shaped jig, and when fitting the outer clutch-race-like section over the rollers, the jig  50  is placed over one half in the axial direction of the rollers and transformed from the state shown in FIG. 32(A) to the state shown in FIG. 32(B), so that the one half in the axial direction of the rollers is pressed inward in the radial direction of the inner clutch-race-like section, while at the same time the outer clutch-race-like section is fitted radially over the rollers from the other half in the axial direction of the rollers. In this state, with the outer clutch-race-like section fitted over the rollers on the other half in the axial direction of them, the jig  50  is removed and then the outer clutch-race-like section is fitted over the one half in the axial direction of the rollers.  
         [0124]    When performing the assembly work using a jig  50  as described above, there is no need to form beveled surfaces on the ends in the axial direction of the rollers arid around the radially inner edge of one end surface in the axial direction of the outer clutch-race-like section. (The beveled surfaces are not necessary but there is no problem if they are formed.)  
         [0125]    Industrial Applicability  
         [0126]    This invention is constructed and functions as described above, and provides a pulley apparatus with built-in roller clutch and assembly method thereof, that makes it possible to maintain durability and reliability of the pulley apparatus, as well as makes it possible to perform the assembly process more easily.