MXPA99011313A - Constant velocity universal joint and method for assembling the same - Google Patents

Abstract

To ease assembly of a tripod (or bipod) joint (10), having the roller (46) on mounted each spherically headed trunnion (28a,b,c) via an inner ring (42), the inner ring (42) has one or a pair of cutouts (52,52a) from one end, and the radially outer and inner surfaces (143a,143b) of the head (132) of each trunnion (128a,b,c) may be barrel-shaped.

Description

UNIVERSAL COUPLING OF CONSTANT SPEED AND METHOD TO ASSEMBLE THE SAME BACKGROUND OF THE INVENTION Field of the invention; The present invention relates to a universal constant speed coupling which is used, for example, for coupling a first transmission shaft and a second transmission shaft to a transmission force transmission section of a motor vehicle. The present invention also relates to a method for assembling this universal constant speed coupling.

Description of the Related Art: A universal constant velocity coupling has been used to date by a drive force transmission section of a motor vehicle, for coupling a first drive shaft and a second drive shaft so as to transmit the rotating force to each axis. This universal constant velocity coupling that relates to the conventional technique is shown in Figures 67 and 68 (see Japanese Patent Laid-Open Publication, Number 7- 103251). The constant speed universal coupling 1 comprises guide grooves 2a, 2b mutually P1720 / 99MX which are formed on an inner wall surface of an outer coupling 3. A spherical tripod joint 4 is arranged between the guide grooves 2a, 2b. An inner roller 5 is externally adjusted to the tripod hinge 4. An outer roller 7 is supported via a plurality of needle bearings 6 on an outer circumferential surface of the inner roller 5. In this arrangement, the surfaces 8a, 8b, 9a, 9b , which extend substantially parallel to the axis of the tripod joint 4, are formed on the circumferential surfaces of the tripod joint 4 and the outer roller 7 on both opposite sides in the rotational direction of the coupling. The surfaces 8a, 8b, 9a, 9b operate in such a way that the force which is applied to the tripod joint 4 and which is effective in the circumferential direction, is divided into two force components. Due to this arrangement, the improvement in the pressure distribution of the contact surface is achieved under the load of the torque. However, in the case of the universal constant speed coupling 1 which relates to the conventional technique described above, for example, each of the components of the force Fi, F2, which is applied to the inner roller 5 by the surface 8b formed on the circumferential surface of the tripod joint 4, it P1720 / 99MX consists of a relatively high load. Therefore, an inconvenience arises since the pressure of the contact surface (force to press the contact surface) which is exerted in the direction of the arrow between the tripod joint 4 and the inner roller 5, increases in comparison with the pressure of the contact surface on other circumferential surfaces. This results in a problem that deteriorates the durability. Additionally, the constant speed universal coupling 1 which relates to the conventional technique comprises the inner roller 5 and the outer roller 7 maintained by the guide grooves 2a, 2b via the needle bearings 6. The articulation 4 tripod is provided such that it moves in the vertical direction along the inner wall surface of the inner roller 5 maintained by the guide grooves 2a, 2b. Therefore, the constant speed universal coupling 1 which refers to the conventional technique is inconvenient since it is impossible to reduce the sliding resistance on the sliding surface of the tripod joint 4 and the inner roller 5.

SUMMARY OF THE INVENTION A general object of the present invention is to provide a universal coupling of P1720 / 99MX constant speed that makes it possible to improve the durability by decreasing the pressure of the contact surface on the contact surface between a stump and a limb annular set externally to the stump. A principal object of the present invention is to provide a universal constant velocity coupling which makes it possible to further improve the induced traction performance by reducing the slip resistance generated when a first drive shaft is tilted and a stump is displaced along a notch guide. Another object of the present invention is to provide a universal constant velocity coupling which makes it possible to further improve the strength of a core without inhibiting assembly or assembly performance when externally fitting an annular member to the core. Still another object of the present invention is to provide a method for assembling a universal constant velocity coupling., which makes it possible to conveniently assemble a stump provided with a spherical surface and an annular member formed with a depression corresponding to the spherical surface of the trunnion. The objects, features and advantages above and others of the present invention will become more apparent from the following P1720 / 99 X description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a sectional, vertical view taken along a direction substantially perpendicular to a longitudinal direction of a universal constant speed coupling according to a first embodiment of the present invention; Figure 2 shows a sectional view, vertical, enlarged, with partial omission, illustrating the universal coupling of constant speed shown in Figure 1; Figure 3 shows a perspective view, partially cut away, illustrating an insulated inner member in an outer cup; Figure 4 shows a perspective view illustrating an inner roller for building the inner member; Figure 5 is a plan view illustrating the inner roller shown in Figure 4; Figure 6 shows a sectional, vertical view taken along a line VI-VI shown in Figure 5; Figure 7 shows a sectional view, P1720 / 99MX vertical taken along a line VII-VII shown in Figure 5; Figure 8 shows a perspective view illustrating a modified embodiment of the inner roller shown in Figure 4; Figure 9 shows a plan view illustrating the inner roller shown in Figure 8; Figure 10 shows a sectional, vertical view taken along a line X-X shown in Figure 9; Figure 11 shows a sectional, vertical view taken along a line XI-XI shown in Figure 9; Fig. 12 illustrates an adjustment condition for installing the inner roller to a stump; Figure 13 illustrates the adjustment condition for installing the inner roller to the stump; Fig. 14 shows a sectional view, vertical, with partial omission, illustrating a modified form of the stump; Figure 15 shows a sectional view, vertical, enlarged with partial omission, illustrating a universal constant speed coupling according to a second embodiment of the present invention; Figure 16 shows a sectional view, vertical, enlarged with partial omission, illustrating a universal coupling of constant speed of P1720 / 99MX according to a third embodiment of the present invention; Figure 17 shows a sectional view, vertical, enlarged with partial omission, illustrating a universal constant speed coupling according to a fourth embodiment of the present invention; Figure 18 shows a sectional view, - vertical taken along a direction substantially perpendicular to a longitudinal direction of a universal constant velocity coupling according to a fifth embodiment of the present invention; Figure 19 shows a sectional view, vertical, enlarged, with partial omission, illustrating the universal coupling of constant speed shown in Figure 18; Figure 20 shows a perspective view, partially cut away, illustrating an inner member shown in Figure 18; Figure 21 shows a sectional view, vertical, enlarged, with partial omission, illustrating a universal coupling of constant speed according to a sixth embodiment of the present invention; Figure 22 shows a sectional view, vertical, enlarged, with partial omission, illustrating a universal coupling of constant speed of P1720 / 99MX according to a seventh embodiment of the present invention; Figure 23 shows a sectional view, vertical, enlarged, with partial omission, illustrating a universal coupling of constant velocity according to an eighth embodiment of the present invention; Figure 24 shows a sectional view, vertical, enlarged, with partial omission, illustrating a universal coupling of constant speed according to a ninth embodiment of the present invention; Figure 25 shows a sectional, vertical view, taken along a substantially perpendicular line, to a longitudinal direction of a universal constant speed coupling according to a tenth embodiment of the present invention; Figure 26 shows a sectional view, vertical, enlarged, with partial omission, illustrating a universal coupling of constant velocity shown in Figure 25; Figure 27 shows a sectional, vertical view, taken along a line XXVII-XXVII, shown in Figure 26; Figure 28 shows an exploded perspective view illustrating an interior member shown in Figure 25 P1720 / 99 X Figure 29 shows an enlarged, partially omitted, sectional vertical view illustrating a modified embodiment of a trunnion to construct the universal constant velocity coupling shown in Figure 25; Figure 30 shows a sectional view, vertical, with partial omission, illustrating a modified embodiment of a first curved surface formed in a head section of the trunnion shown in Figure 27; Figure 31 shows an enlarged perspective view illustrating an inner roller for building an inner member shown in Figure 28; Figure 32 shows a plan view illustrating the inner roller shown in Figure 31; Figure 33 shows a vertical sectional view, taken along a line XXXIII-XXXIII shown in Figure 32; Figure 34 shows a sectional, vertical view, taken along a line XXXIV-XXXIV shown in Figure 32; Figure 35 illustrates an adjustment condition for installing the inner roller to the journal of the constant velocity universal coupling shown in Figure 25; Figure 36 illustrates the adjustment condition for installing the inner roller to the journal P1720 / 99MX universal constant speed coupling shown in Figure 25; Figure 37 shows the perspective view illustrating the modified embodiment of the inner roller shown in Figure 31; Figure 38 shows a plan view illustrating the inner roller shown in Figure 37; Figure 39 shows a sectional, vertical view, taken along a line XXXIX-XXXIX shown in Figure 38; Figure 40 shows a sectional, vertical view, taken along an XL-XL line shown in Figure 38; Figure 41 shows a sectional view, vertical, enlarged, with partial omission, illustrating another modified embodiment of the trunnion to construct the universal constant velocity coupling shown in Figure 25; Figure 42 shows, with partial omission, an enlarged vertical sectional view taken along a direction substantially perpendicular to a longitudinal direction of a universal constant velocity coupling according to an eleventh embodiment of the present invention; Figure 43 shows a sectional, vertical view, taken along a line XLIII-XLIII shown in Figure 42; Figure 44 shows a view in P1720 / 99MX perspective, exploded, illustrating an outer cup to construct the universal constant velocity coupling shown in Figure 43; Figure 45 shows a sectional, vertical view taken along a direction substantially perpendicular to a longitudinal direction to a universal constant speed coupling according to a twelfth embodiment of the present invention; Figure 46 shows a sectional view, vertical, enlarged, with partial omission, illustrating the universal coupling of constant speed shown in Figure 45; Figure 47 shows a sectional, vertical view, taken along a line XLVII-XLVII, shown in Figure 46; Figure 48 shows an exploded perspective view illustrating an inner member for building the universal constant speed coupling shown in Figure 45; Figure 49 shows a perspective view illustrating the trunnions including a spiral shoulder to construct the universal constant speed coupling shown in Figure 45; Figure 50 shows a front view illustrating the stumps shown in Figure 49; Figure 51 shows a sectional view, P1720 / 99MX vertical, taken along a LI-LI line shown in Figure 50; Figure 52 shows a sectional, side view, taken along a line LII-LII shown in Figure 50; Figure 53 shows a plan view illustrating the stumps shown in Figure 49; Figure 54 shows a sectional, vertical view, taken along a line LIV-LIV shown in figure 53; Figure 55 shows a perspective view illustrating the trunnions according to a modified embodiment; Figure 56 shows a front view illustrating the stumps shown in Figure 55; Figure 57 shows a sectional, vertical view taken along a line LVII-LVII shown in Figure 56; Figure 58 shows a sectional, side view taken along a line LVIII-LVIII shown in Figure 56; Figure 59 shows a plan view illustrating the stumps shown in Figure 55; Figure 60 shows a sectional, vertical view taken along a line LX-LX shown in Figure 59; Figure 61 shows a perspective view illustrating comparative stumps P1720 / 99MX built for comparison purposes; Figure 62 shows a front view illustrating the stumps shown in Figure 61; Figure 63 shows a sectional, vertical view taken along a line LXIII-LXIII shown in Figure 62; Figure 64 shows a sectional, side view taken along a line LXIV-LXIV shown in Figure 62; Figure 65 shows a plan view illustrating the stumps shown in Figure 61; Figure 66 shows a sectional, vertical view taken along a line LXVI-LXVI shown in Figure 62; Figure 67 shows a sectional, vertical view with partial omission, illustrating a universal coupling of constant speed that relates to the conventional technique; and Figure 68 shows a sectional, side view, with partial omission, illustrating the universal constant speed coupling that relates to the conventional technique.

DESCRIPTION OF THE PREFERRED MODALITIES With reference to figures 1 and 2, the reference number 10 indicates a universal constant speed coupling according to a first embodiment of the present invention.

P1720 / 99MX The universal constant speed coupling 10 basically comprises a cylindrical outer cup (outer member) 12 having an opening and which is integrally connected to one end of a first shaft not shown, and an inner member 16 which is secured to a end of a second shaft 13 and accommodating in a hole 14 of the outer cup 12. As shown in Figure 1, three guide grooves 18, extending in the axial direction and separating from each other by approximately 120 degrees around the central axis, they are formed on the inner wall surface of the outer cup 12. As shown in Figure 2, the guide groove 18 includes a boundary section 20 that is formed to have a planar configuration, and the sections 22a, 22b of lateral surface which are formed substantially perpendicular on both sides of the boundary section 20 and which are opposite each other. Each of the side surface sections 22a, 22b is formed to have a planar configuration that extends along the axial direction of the outer cup 12. A pair of stepped sections 24a, 24b that continue to the lower ends of the ends. side surface sections 22a, 22b, and which are opposite each other, are formed on the inner wall surface of the outer cup 12.

P1720 / 99MX A ring-shaped spiral flange 26 is externally fitted to the second shaft 13. Three trunnions 28a to 28c, which extend towards the guide grooves 18 respectively and which are separated from each other by approximately 120 degrees around the central axis, are they form integrally on the outer circumferential surface of the spiral flange 26. As shown in Figure 3, each of the trunnions 28a, (28b, 28c) integrally comprises a neck section 30 extending radially outwardly. from the spiral rim 26 in the form of a ring, and a flat disk section 34 having a flat, upper surface 32. A circumferential, outer surface of the trunnion 28a, (28b, 28c), which is substantially perpendicular to the upper surface 32, is formed to be a spherical surface 36. A chamfering section 38 having a curved cross section is provided at a limit between the upper surface 32 and the spherical surface 36 and at a boundary between the lower surface and the spherical surface 36 of each of the trunnions 28a, (28b, 28c). As shown in Figure 3, those placed between the trunnion 28a (28b, 28c) and the side surface sections are a side roll (first annular member) 42 which is composed of a ring member and which is formed with a depression 40 that has a spherical surface on P1720 / 99MX the interior, complete circumferential surface corresponding to the spherical surface 36 of the journal 28a, (28b, 28c), and an outer roller (second annular member) 46 which is externally adjusted to the inner roller 42 by a plurality of needle bearings (bearing members) 44. The plurality of needle bearings 44 is installed from shape rotatable in annular depressions 48 which are formed in the inner circumferential surface of the outer roller 46, and are incorporated so that they do not disengage from the depressions 48 due to the effect of voussoir. The cuts 52 are formed in the inner roller 42 in order to easily assemble the stump 28a (28b, 28c) in a hole 50 of the inner roller 42. As shown in Figure 4, the cuts 52 are formed to have a pair of configurations in. circular arc shape, mutually opposite, placed in the boundary portions between an upper surface 54 and an inner wall surface of the circular hole 50. Alternatively, as shown in Figure 8 instead of the inner roller 42, it is also preferable using an inner roller 42a including substantially elliptical cuts 52a formed in the boundary portions between the inner surface 54 and the inner wall surface. The spherical surface 36 of the trunnion 28a (28b, 28c) and the depression 40 of the inner roller 42 P1720 / 99MX are provided to make surface to surface contact with each other. Therefore, the trunnion 28a (28b, 28c) is provided in a rotatable manner in the direction of the arrow A about a center of a point 0 (see Figure 2) with respect to the inner roller 42, which is provided in a rotatable manner. in the circumferential direction (direction of the arrow B) along the spherical surface 36 about a center of rotation of the trunnion 28a (28b, 28c). Additionally, the journal 28a (28b, 28c) and the inner roller 42 are provided in a displaceable manner in the vertical direction (direction of the arrow C) in an integrated manner with respect to the needle bearings 44 maintained by the outer roller 46. The universal coupling 10 of constant speed according to the first embodiment of the present invention is basically constructed as described above. Then, its operation, function, and effect will be explained. When the first shaft not illustrated is rotated, its rotational force is transmitted via the outer cup 12 to the inner member 16. Accordingly, the second shaft 13 is rotated in the predetermined direction by the aid of the stump 28a (28b, 28c) . That is, the rotational force of the outer cup 12 is transmitted to the inner roller 42 via the needle bearings 44 and the outer roller 46.

P1720 / 99 X which makes contact with the guide grooves 18. The rotational force is further transmitted to the trunnions 28a (28b, 28c) via the spherical surfaces 36 which make surface-to-surface contact with the depressions 40 of the inner rollers 42. this way, the second shaft 13 is rotated, which engages with the trunnions 28a (28b, 28c). In this arrangement, when the second tree 13 is inclined at a predetermined angle with respect to the outer cup 12 provided with the first shaft, then the stump 28a (28b, 28c) makes sliding movement in the direction of the arrow A around the center of rotation of the point 0, or the trunnion 28a (28b, 28c) makes sliding movement in the circumferential direction (direction of the arrow B) along the depression 40 having the spherical surface around the center of rotation of the axis of the stump 28a (28b, 28c), while maintaining the state in which the stump surface 28a (28b, 28c) makes surface-to-surface contact with the depression 40 having the spherical surface formed on the inner roller 42. The journal 28a ( 28b, 28c) is also displaced along the axial direction (arrow direction C) of the trunnion 28a (28b, 28c) integrally with the inner roller 42 which makes the sliding movement with respect to the bearings of needles 44 retained by the outer roller 46.

P1720 / 99MX Additionally, the journal 28a (28b, 28c) is moved in the direction substantially perpendicular to the axle of the journal 28a (28b, 28c), ie, in the longitudinal direction of the guide groove 18, by the aid of the external roller 46 which makes the sliding movement along the guide groove 18. In this way, the rotational movement of the first shaft is smoothly transmitted to the second shaft 13 without being affected by the angle of inclination of the second shaft 13 with respect to the outer cup 12. In the first embodiment, the spherical surface 36 is provided on the lateral surface of the trunnion 28a (28b, 28c) to make the sliding movement with respect to the inner roller 42 formed with the depression 40 corresponding to the spherical surface 36. Additionally. , the trunnion 28a (28b, 28c) and the inner roller 42 are provided in a displaceable manner along the axial direction of the trunnion 28a (28b, 28c). In this way, it is possible to decrease the slip resistance and reduce the induced pulling force. Additionally, the journal 28a (28b, 28c) and the depression 40 of the inner roller 42 make surface to surface contact with each other to reduce the contact surface pressure. In this way, it is possible to improve the durability of the universal coupling 10 of constant speed.

P1720 / 99MX In other words, in the case of the conventional technique as shown in Figure 67, the displacement of the tripod joint 4 in the axial direction is effected based "on the sliding movement between the inner roller 5 and the joint. tripod 4. On the contrary, in the case of the embodiment of the present invention, the displacement is effected based on the sliding movement between the needle bearings 44 and inner roller 42 to be moved integrally with the trunnion 28a ( 28b, 28c) As a result, in the embodiment of the present invention, the friction during displacement can be decreased, and the slip resistance can be decreased, compared to the conventional technique. refers to the load resulting from the frictional resistance generated by the displacement of the trunnion 28a (28b, 28c) along the guide groove 18. Lueg or, a method for assembling the universal constant speed coupling according to the first embodiment of the present invention will be explained later, as exemplified by the cases in which the journal 28a (28b, 28c) is installed in the hole 50 of the inner roller 42 or the inner roller 42a, respectively.

P1720 / 99MX The inner roller 42 (see Figure 4), which is provided with the pair of mutually opposite cuts 52, is used as follows. That is, the spherical surface of the journal 28a '(28b, 28c) is inserted into the depression 40 of the inner roller 42 along the pair of cuts 52 in a state in which the upper surface 54 of the inner roller 42 is allowed to is substantially perpendicular to the flat upper surface 32 of the stump 28a (28b, 28c). The trunnion 28a (28b, 28c) is tilted so that the trunnion shaft 28a (28b, 28c) is substantially perpendicular to the upper surface 32 of the inner roller 42. In this way, the inner roller 42 is mounted to the trunnion 28a ( 28b, 28c). The inner roller 42a (see Figure 8), which is provided with the substantially elliptical cut 52a, is used as follows. That is, as shown in Figure 12, the trunnion 28a (28b, 28c) is inserted along the substantially elliptical cut 52a, while the trunnion 28a (28b, 28c) is inclined at an angle? with respect to the inner roller 42a. In this way, the inner roller 42a is installed on the journal 28a (28b, 28c). The symbols in figures 12 and 13 are as follows. That is, the assembly angle is represented by?. The radius of the spherical surface 36 of the trunnion 28a (28b, 28c) is represented by R. The width of the spherical surface of the trunnion 28a (28b, 28c) is P1720 / 99MX represents H. The short cutting radius 52a of the inner roller 42a is represented by r. The width of the inner roller 42a is represented by h. The radius of the stump 28a (28b, 28c) is represented by d. The projected long width of the spherical surface 36 of the journal 28a (28b, 28c), which is obtained when the assembly angle is inclined by? it is represented by X. The projected short width of the spherical surface 36 of the trunnion 28a (28b, 28c) which is obtained when the angle of assembly is inclined by 0 is represented by Y. The spacing between the cut 52a of the inner roller 42a and the neck section 30 of the stump 28a (28b, 28c) is represented by •. In this embodiment, the condition, under which the projected short width Y of the spherical surface 36 of the stump 28a (28b, 28c) is smaller than 2R (diameter of the spherical surface) (the spherical surface 36 is secured within the width h of the inner roller 42a), is represented by the following expression (1).

R - Hsen0 - / R2 -R2 • eos? > 0 (1) The condition under which Y < X is satisfied, it is represented by the following expression (2).

P1720 / 99MX The condition, under which the stump 28a (28b, 28c) does not interfere with the inner roll 42a, is represented by the following expression (3). + r * serü 90 ° - é - cos -i - d > 0 (3) The trunnion configurations 28a (28b, 28c) and the cut 52a of the roller 42a are designed so that the expressions (1) to (3) are satisfied. It is assumed that the angle of assembly? it is adjusted to be greater than the operating angle of the universal speed-constant coupling 10. Alternatively, as shown in the Figure 14, the trunnion 28a (28b, 28c), which is formed to extend from the spiral flange 26, could be constructed so that the neck section 30 is provided in a deviated position with respect to the axial direction of the central portion of the ring-shaped spiral flange 26. Then, the universal couplings of constant speed according to other embodiments are shown in figures 15 to 17. The same constituent components as those of the universal coupling 10 of constant speed shown in Figure 1 are they designate by the same P1720 / 99MX reference numbers, the detailed explanation of which will be omitted. As shown in Figure 15, a universal speed coupling 10a constant according to the second embodiment is constructed as follows. That is, a ring member 58, having a spherical surface 36 formed on its outer circumferential surface, is forcedly inserted into a columnar stump 56a (56b, 56c). This arrangement is advantageous since the stump 56a, (56b, 56c) is easily manufactured. As shown in Figure 16, a universal coupling 10b of constant velocity according to the third embodiment is constructed as follows. That is, a boundary section 20a of a guide groove 18 of an outer cup 12 is formed to have a curved configuration. A fixed member 60 is provided in the boundary section 20a. This arrangement is advantageous since the universal coupling 10b of constant speed is allowed to have a light weight, and it is possible to avoid the increase in the amount of lubricating oil to be loaded in the outer cup 12. As shown in Figure 17, a universal coupling 10c of constant velocity according to the fourth embodiment is constructed as follows. That is, a limit section 20b of a guide groove 18 of an outer cup 12 is formed to P1720 / 99MX have a curved configuration in wave form so that the universal coupling 10c of constant speed has a light weight. Then, a universal constant velocity coupling 70 according to the fifth embodiment of the present invention is shown in Figures 18 to 20. The same constituent components as those of the universal constant velocity coupling 10 according to the first embodiment are designated by the same reference numbers, the detailed explanation of which will be omitted. The universal coupling 70 of constant velocity according to the fifth embodiment comprises cylindrical inner rollers (first annular members) 72 each of which has a depression 40 having a spherical surface formed on the inner wall surface to make surface-to-surface contact with a spherical surface 36 of a journal 28a (28b, 28c), and outer rollers (second annular members) 74 each of which is arranged on the outer circumferential surface of the inner roller 72 via the needle bearings 44. The bearing The needle 44 is held on the outer circumferential surface of the inner roller 72 by the aid of a washer 76 and a circular spring 78. In the fifth embodiment, as shown in FIG.

P1720 / 99MX Figure 19, the sliding surface is provided between the outer roller 74 and the needle bearings 44. The journal 28a (28b, 28c), the inner roller 72 and the needle bearings 44 are provided integrally movable to along the axial direction (arrow direction C) of the trunnion 28a (28b, 28c) with respect to the outer roller 74. In this way, it is possible to decrease the sliding resistance and reduce the induced tractive force. Additionally, the 28th stump (28b, 28c) and the depression 40 of the inner roller 72 make surface to surface contact with each other so that the contact surface pressure is reduced. In this way, it is possible to improve the durability of the universal constant speed coupling. Then, the universal couplings of constant velocity according to other embodiments are shown in Figures 21 to 24. The same constituent components as those of the universal coupling 70 of constant velocity shown in Figure 19 are denoted by the same reference numbers, the detailed explanation of which will be omitted. As shown in Figure 21, a coupling. universal 70a constant speed according to the sixth embodiment is constructed as follows. That is, a ring member 58, who has P172Q / 99MX a spherical surface 36 formed on its outer spherical surface, is forcedly inserted into a columnar stump 56a (56b, 56c). This arrangement is advantageous since the stump 56a "(56b, 56c) is easily manufactured.As shown in Figure 22, a universal coupling 70b of constant velocity according to the seventh embodiment is constructed as follows. limit 20a of a guide groove 18 and an outer cup 12 is formed to have a curved conjugation A fixed member 60 is provided in the boundary section 20a This arrangement is advantageous since the universal constant speed coupling is allowed to have a weight light, and it is possible to avoid the increase in the amount of lubricating oil to be loaded in the outer cup 12. As shown in Figure 23, a universal coupling 70c constant speed according to the eighth embodiment is constructed as follows That is, a boundary section 20b of a guide groove 18 of an outer cup 12 is formed to have a curved shape in a waveform so that the universal speed coupling 70c. Ad constant have a light weight. As shown in Figure 24, a universal constant velocity coupling 70d according to the ninth embodiment is constructed as P1720 / 99MX follows. That is, a flat outer roller 80 having an i-elliptical cross-sectional configuration is provided. Guide grooves 82a, 82b, each of which has a semi-elliptical configuration corresponding to the outer roller cross-sectional configuration 80 are formed in the sections of the lateral surface 22a, 22b of the guide groove 18. In this arrangement , the outer roller 80 is restricted by the guide grooves 82a, 82b for displacement in the axial direction (direction of arrow C) of trunnion 28a (28b, 28c).

In this way, the displacement can easily be effected in the axial direction of the stump 28a (28b, 28c) by using the sliding surface of the inner circumferential surface of the outer roller 80 and the needle bearings 44. From the first to the ninth embodiments in the present invention have been explained by using the universal constant speed couplings, tripod type 10, 10a to 10c, 70, 70a to 70d, each of which is provided with three trunnions 28a to 28c, 56a to 56c. However, there is no limit to this. It is evident that the present invention is also applicable to bipod-type constant speed universal couplings, not illustrated. Then, a universal coupling of constant velocity according to the tenth embodiment of the present invention is shown in P1720 / 99MX Figures 25 and 26. The universal constant speed coupling 110 basically comprises an outer, cylindrical cup (outer member) 112"having an opening and which is integrally connected to one end of a first shaft not illustrated, and a member interior 116 which is secured to one end of a second shaft 113 and which fits into a hole 114 of the outer cup 112. The outer cup 112 is formed in an integrated manner as shown in Figure 25, three guide grooves 118, extending in the axial direction and separating from each other by approximately 120 degrees around the central axis, are formed on the inner wall surface of the outer cup 112. As shown in Figure 26, the guide groove 118 includes a boundary section 120 which is formed to have a circular arc-shaped cross section about the center of the axis of the outer cup 112, the side surface sections 122a, 122b each of which is formed to have a planar configuration that extends along the axial direction of the outer cup 112 and that are opposite each other on both sides of the boundary section 120, and the notches 124a, 124b that form mutually opposite at both ends of the section 120 limit and that extend along the axial direction. Each of the notches 124a, 124b P1720 / 99MX is formed with a planar shoulder 125 that is substantially perpendicular to the side surface section 122a, 122b. A spiral rim 126 in the form of a ring is externally adjusted to the second shaft 113. Three trunnions 128a to 128c, which extend towards the guide grooves 118 respectively and which are separated from each other by approximately 120 degrees around the central axis, are formed in a manner integral on the circumferential, outer surface of the spiral flange 126. As shown in Figure 28, each of the trunnions 128a (128b, 128c) has a neck section 130 that expands radially outwardly from the spiral flange 126 of ring, of a head section 132 which is integrally constructed with the neck section 130 and which is formed to have a thin wall planar configuration. Alternatively, as shown in Figure 29, each of the sections can be formed by forcefully inserting a ring member 135 into the outer circumferential surface of a columnar stump 133a (133b, 133c). A first curved surface 134a, which is formed to have a circular arc-shaped configuration having a predetermined curvature as seen in the axial direction of the outer cup 112 (see Figure 26) and which is formed to have a linear configuration as it looks in one direction P1720 / 99MX perpendicular to the axis of the outer cup 112, is provided on the upper surface of the head section 132 (see Figure 27). In this embodiment, as shown in Figure 27, "the shape of the first curved surface 134a is not limited to the linear configuration as seen in the direction perpendicular to the axis of the outer cup 112. Alternatively, as shown in Figure 30, the shape of the first curved surface 134a can be formed to have a circular arc-shaped configuration having a predetermined curvature A second curved surface 134b, which is similar to the first curved surface 134a, is formed to Continue towards the neck section 130 on the lower surface of the head section 132. The head section 132 further comprises a spherical surface 136 which is formed on the outer circumferential surface between the first curved surface 134a and the second curved surface 134b. A chamfering section, not shown, having a curved cross section may be provided at a boundary between the first curved surface 134a and the spherical surface 136 and at a boundary between second curved surface 134b and spherical surface 136 of each of trunnions 128a, (128b, 128c). As shown in Figure 28, those placed between the stump 128a (128b, 128c) and the P1720 / 99MX side surface sections 122a, 122b are an inner roller (first annular member) 142 which is composed of a ring member and which is formed with a depression 140 having a spherical surface corresponding to the spherical surface 136 of the stump 128a (128b, 128c), and an outer roller (second annular member) 146 which is composed of a ring member having a larger diameter than that of the inner roller 142 and which is externally adjusted to the inner roller 142 via a plurality of needle bearings (co-member members) 144. The a plurality of needle bearings 144 is rotatably mounted in annular depressions 148 which are formed in the inner circumferential surface of the outer roller 146, and are incorporated so that they do not disengage from the depressions 148 due to the voussoir effect. For example, a non-illustrated retaining fitting can be provided and used so that the plurality of needle bearings 144 is installed along the circumferential surface of the exterior of the inner roller 142. As shown in Figure 31, a cut 152 substantially elliptical is formed in a boundary between the upper surface 154 and the inner wall surface of the inner roller 142 in order to easily assemble the stump 128a (128b, 128c) in a P1720 / 99MX hole 150 of the inner roller 142. When the ring member 135 is forcedly inserted into the outer circumferential surface of the columnar stump 133a (133b, 133c), as shown in Figure 37, instead of the inner roller 142 , it is preferred to use an inner roller 142a which includes a pair of circular, mutually opposite circular arc-shaped cuts 152a, 152b formed in border portions between the upper surface 154 and the inner wall surface of the circular hole 150. An annular projection 156 , having a cross-sectional configuration corresponding to the notch 124a, 124b and projecting radially outwardly, is formed in an upper portion of the outer circumferential surface of the outer roller 146. The annular projection 156 has a first engaging surface 158 having a circular arc-shaped cross section for contacting the boundary section 120, and a second coupling section 160 formed to have a planar configuration for contacting the shoulder 125. An outer circumferential surface 162 for making surface-to-surface contact with the side surface section 122a, 122b is formed in a lower portion of the annular projection 156. In this arrangement, the annular projection 156 P1720 / 99MX works as follows. That is, when the outer roller 146 rotates about the axial direction of the outer cup 112, then the first coupling surface 158 engages the boundary section 120, and the second coupling surface 160 engages the shoulder 125. Accordingly, the attitude of the outer roller 146 is maintained so that the outer roller 146 is substantially parallel to the axial direction. The spherical surface 136 of the stump 128a (128b, 128c) and the depression 140 of the inner roller 142 are provided to make surface to surface contact with each other. Therefore, the stump 128a (128b, 128c) is provided in a rotatable manner in the direction of the arrow A about a center of a point O (see Figure 26) with respect to the roll 142, and is provided in a rotatable manner in the circumferential direction (direction of the arrow B) along the spherical surface 136 about an axis of rotation of the trunnion axis 128a (128b, 128c). Additionally, the journal 128a (128b, 128c) and the inner roller 142 are provided in a displaceable manner in the vertical direction (arrow direction C) in an integrated manner with respect to the needle bearings 144 held by the outer roller 146. Additionally, the stump 128a (128b, 128c) is provided in a sliding manner in the direction P1720 / 99MX axial (arrow direction D) of the outer cup along the guide groove 118 by the aid of the outer roller 146 provided with the annular projection 156 to engage the notch 124a, 124b. The universal coupling 110 of constant speed according to the tenth embodiment of the present invention is basically constructed as described above. Then, its operation, function, and effects will be explained. The rotational force of the outer cup 112 is transmitted to the inner roller 142 via the needle bearings 144 and the outer roller 146 which makes contact with the guide groove 118. The rotational force is transmitted to the journals 128a (128b, 128c) via the spherical surfaces 136 that make surface-to-surface contact with the depressions 140 of the inner rollers 142. In this manner, the second shaft 113 is rotated, which engages the journals 128a (128b, 128c). In this arrangement, when the second shaft 113 is inclined at a predetermined angle with respect to the outer cup 112 provided with the first shaft, then the stump 128a, (128b, 128c) makes sliding movement in the direction of the arrow A around the center of rotation of point 0, or stump 128a (128b, 128c) makes sliding movement in the circumferential direction (direction of arrow B) P1720 / 99MX along the depression 140 having the spherical surface about the center of rotation of the axle of the trunnion 128a (128b, 128c), while maintaining the state in which the spherical surface 136 of the trunnion 128a (128b, 128c) ) makes contact surface to surface with the depression 140 having the spherical surface formed in the inner roller 142. The stump 128a (128b, 128c) also travels along the axial direction (arrow direction C) of the stump 128a (128b, 128c) integrally with the inner roller 142 which makes sliding movement with respect to the needle bearings 144 maintained by the outer roller 146. Additionally, the stump 128a (128b, 128c) is moved in the direction substantially perpendicular to the trunnion shaft 128a (128b, 128c), i.e., in the longitudinal direction of the guide groove 118 by the aid of the outer roller 146 which makes sliding movement along the guide groove 118. In this In this case, the first coupling surface 158 engages with the boundary section 120, and the second coupling surface 160 engages the shoulder 125. Accordingly, the attitude of the outer roller 146 is maintained so that the outer roller 146 is substantially parallel to the axial direction of the outer cup 112. Therefore, it is possible to decrease the P1720 / 99MX external roller sliding friction 146, and it is possible to suppress the occurrence of the friction resulting from sliding friction, by maintaining the height of the outer roller 146 so that the outer roller 146 is substantially parallel to the axial direction of the outer cup 112. The outer roller 146 is provided in such a way that it slides along the guide groove 118 by the aid of the annular projection 156 and the outer circumferential surface 162, and rotates in the guide groove 118 by the aid of the needle bearings 144 intervening between the outer roller 146 and the inner roller 142. Therefore, it is possible to decrease the coefficient of friction. Additionally, the outer roller 146 makes surface to surface contact with the guide groove 118 via the annular projection 156 and the circumferential, outer surface 162. Therefore, the contact area is increased, and it is possible to reduce the pressure of the contact surface. In this way, the rotational movement of the first shaft is smoothly transmitted to the second shaft 113 without being affected by the angle of inclination of the second shaft 113 with respect to the outer cup 112. In the tenth embodiment, the spherical surface 136 is provided in the lateral surface of the stump 128a (128b, 128c) to make the movement P1720 / 99MX sliding relative to the inner roller 142 formed with the depression 140 corresponding to the spherical surface 136. Additionally, the stump 128a (128b, 128c) and the inner roller 142 are provided in a displaceable manner along the direction of the stump 128a (128b, 128c). In this way, it is possible to decrease the slip resistance and reduce the induced pulling force. Additionally, the die 128a (128b, 128c) and the depression 140 of the inner roller 142 make surface to surface contact with each other to reduce the contact surface pressure. In this way, it is possible to improve the durability than the universal coupling 110 of constant speed. Next, a method for assembling the universal constant speed coupling according to the tenth embodiment of the present invention will be explained later, as identified by a case in which the stump 128a (128b, 128c) is installed in the hole 150 of the inner roller 142. Inner roller 142 (see Figure 31), which is provided with substantially elliptical cut 152, is used as follows. That is, as shown in Figure 36, the stump 128a (128b, 128c) is inserted along the substantially elliptical cut 152, while the stump 128a (128b, 128c) is inclined at an angle? with respect to the roller Inner P1720 / 99MX 142. In this way, the inner roller 142 is installed to the stump 128a (128b, 128c). In this arrangement, the second shaft 113 extends in a direction substantially perpendicular to the plane of the paper of Figure 36. The symbols in Figures 35 and 36 are as follows. That is, the assembly angle is represented by?. The radius of the spherical surface 136 of the trunnion 128a (128b, 128c) is represented by R. The width of the spherical surface of the trunnion 128a (128b, 128c) is represented by H. The short radius of the cut 152 of the inner roller 142 is represents with r. The width of the inner roller 142 is represented by h. The radius of the stump 128a (128b, 128c) is represented by d. The width of the projected length of the spherical surface 136 of the stump 128a (128b, 128c), which is obtained when the assembly angle is inclined by?, Is represented by X, the projected short width of the spherical surface 136 of the stump 128a ( 128b, 128c), which is obtained when the mounting assembly angle is inclined by?, Is represented by Y. The spacing between the cut 152 of the inner roller 142 and the neck section 130 of the stump 128a (128b, 128c) is shown by d. In this embodiment, the condition, under which the projected short width Y of the spherical surface 136 of the stump 128a (128b, 128c) is smaller than 2R (diameter of the spherical surface) P1720 / 99MX (the spherical surface 136 is secured within the width h of the inner roller 142), is represented by the following expression (1).

R - Hsen? -? / R2 -R2 • eos? > 0 (1) The condition, under which Y < X is satisfied, it is represented by the following expression (2).

The condition, under which the stump 128a (128b, 128c) does not interfere with the inner roller 142, it is represented by the following expression (3).

The trunnion configurations 128a (128b, 128c) and the cut 152 of the inner roller 142 are designated so that the above expressions (1) to (3) are satisfied. It is assumed that the angle of assembly? is adjusted to be greater than the angle formed by the trunnion shaft 128a (128b, 128c) and the inner roller shaft 142 determined based on the operating angle of the universal constant speed coupling 110 (angle formed by the first P172Q / 99MX tree and second tree 113) in the paper plane of Figure 36 (plane including the center axes of the three trunnions 128a to 128c). On the other hand, the columnar stump 133a (133b, 133c) (see Figure 29) provided with the ring member 135 inserted in a forced manner is installed as follows the inner roller 142a (see Figure 37) which is provided with the pair of cuts mutually opposite 152a, 152b. In this case, the spherical surface 136 of the journal 133a (133b, 133c) is inserted into the depression 140 of the inner roller 142 along the pair of cuts 152a, 152b in a state in which the upper surface 154 of the inner roller 142 it is allowed to be substantially perpendicular to the upper surface of the stump 133a, (133b, 133c). The stump 133a (133b, 133c) is tilted so that the trunnion axis 133a (133b, 133c) is substantially perpendicular to the upper surface of the inner roller 142. In this manner, the inner roller 142 is installed to the trunnion 133a (133b) , 133c). Alternatively, as shown in Figure 41, the stump 128a (128b, 128), which is formed to extend from the spiral flange 126, may be constructed so that the neck section 130 is provided in a deviated position with with respect to the axial direction of the central portion of the ring-shaped spiral flange 126.

P1720 / 99MX Next, a universal coupling 170 of constant velocity according to an eleventh embodiment of the present invention is shown in Figures 42 to 44. The same constituent components as those of the universal coupling 110 of constant speed according to the tenth embodiment they are designated by the same reference numbers, the detailed description of which will be omitted. The universal coupling 110 of constant speed according to the tenth embodiment is different from the universal coupling 170 of constant speed according to the eleventh embodiment since the former comprises the outer cup 112 which is formed in an integrated manner, while the latter comprises an outer cup 172 that is composed of two members. That is, as shown in Figure 44, the outer cup 172 of the universal speed-controlled coupling 170 according to the eleventh embodiment has three extended sections 174a through 174c extending in the axial direction and forming and separating between yes by 120 degrees respectively around the central axis. The outer cup 172 comprises a main body 176 for forming the guide grooves 118 between the adjacent extended sections 174a to 174c, and a cylindrical member 178 to be externally adjusted to the P1720 / 99MX extended sections 174a to 174c, a ring at 0 180 to prevent any leakage of the lubricating oil loaded inside, is installed in a connecting section between the main body 176 and the cylindrical member 178. An annular groove 182 for clamping a cover (not shown) by the aid of a non-illustrated band is formed at one end of the outer circumferential surface of the cylindrical member 178. In this embodiment, the cylindrical member 178 is formed by the pressing operation of an iron plate. not illustrated. The annular groove 182 is formed simultaneously by means of press work as well. Therefore, the universal coupling 170 of constant velocity according to the eleventh embodiment is advantageous as follows. That is, the formation of the annular groove 182, which has been made by machining in the conventional technique, can be performed substantially simultaneously by means of the press work of the cylindrical member 178. Therefore, it is possible to eliminate the step required for machining and improve production efficiency. The other construction, function and effect are the same as those of the universal coupling 110 of constant speed according to the tenth modality, the detailed explanation of the P1720 / 99MX same. The tenth and eleventh embodiments have been explained by using the tripod-type constant speed universal couplings 110, 170, each of which is provided with the three trunnions 128a through 128c, 133a through 133c. However, there is no limitation to this. It is a matter of the present invention also being applicable to universal couplings of constant speed, bipod type not illustrated. Next, a universal coupling 210 of constant velocity according to the twelfth embodiment of the present invention is shown in FIGS. 45 to 54. The same constituent components as those of the universal coupling 110 of constant speed according to the tenth embodiment are designated by the same reference numerals, the detailed explanation of which will be omitted. As shown in Figure 45, each of the trunnions 228a (228b, 228c) comprises a neck section 230 extending radially outwardly from a ring-shaped spiral flange 126, and a head section 232 which is constructed integrally with the neck section 230 and which is formed to have a thin wall planar configuration. As shown in Figures 49 to 54, as P1720 / 99MX a nape section 233, which extends slightly towards the adjacent trunnion 228b (228c, 228a), is formed integrally on one side along the circumferential direction of the spiral shoulder 126, of the neck section 230 of each of the stumps 228a (228b, 228c). As shown in Figure 52, the neck section 233 has its cross-sectional configuration tapering gradually towards the adjacent trunnion 228b as seen from the side of the head section 232. As shown in Figure 54, the nape section 233 has its cross-sectional configuration that is formed to have a substantially linear shape, substantially along the vertical direction and substantially continuously to a slightly narrow portion 235 of the head section 232 as seen in FIG. axial direction of the second shaft 113. Now a comparison and investigation will be made for the shape of a comparative stump 270a (270b, 270c) (see Figures 61 to 66) and for the stump shape 228a (228b, 228c) according to the twelfth modality. In the case of the comparative stump 270a (270b, 270c), the cross-sectional configuration of the neck section 274 of the trunnion 270a (270b, 270c) is formed to be a perfect circle of agreement as seen from the side of the section 272. For the P1720 / 99 X, in the case of the stump 228a (228b, 228c) to construct the universal coupling 210 of constant speed according to the twelfth embodiment, the section of ñuca 233 is formed, which extends only slightly to one side of the adjacent stump 228b (228c, 228a). The cross-sectional configuration thereof is formed to have the curved configuration that is used gradually as seen from the side of the head section 232. In the case of the comparative stump 270a (270b, 270c), the narrow part 276 (see Figure 66) of the head section 272 is large, and is formed in linear symmetry in which the axis of the head section 272 is the axis of symmetry, as seen in the direction axial of the second shaft 113. By contrast, in the case of the twelfth embodiment, the diameter of the neck section 230 is larger compared to the comparative stump 270a (270b, 270c), and the 228a stump (228b, 228c ) is formed asymmetrically. Therefore, in the twelfth embodiment, the cross-sectional area of the trunnion support 228a to 228c can be increased, and it is possible to further improve the strength of the trunnion 228a to 228c. Additionally, in the twelfth embodiment, the neck section 233 is formed on only one side along the circumferential direction of the spiral flange 226. Therefore, the performance of P1720 / 99MX assembled from the die 228a to 228c is not inhibited with respect to the inner roller 142. In this way, it is possible to smoothly assemble the die 228a to 228c to the inner roller 142. Additionally, the shape of the cross section of the neck section 233, which is formed to have the curved configuration, makes it possible to simplify the structure of an unillustrated die to be used to integrally form the stubs 228a to 228c including the spiral flange 126. Then, the stubs 280a to 280c of according to a modified embodiment are shown in Figures 55 to 60. The stump 280a to 280c according to this modified embodiment differs in that the cross-sectional configuration of a nape section 232 is angular as seen from the side of the section of head 232 (see Figure 58). The cross-sectional configuration, which is formed to be angular, is advantageous since the cross-sectional area of the trunnion support 280a to 280c can be made larger. The other function and effect are the same as those of the previous modality, whose detailed explanation is omitted.

P1720 / 99MX

Claims (32)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; A universal constant velocity coupling having a cylindrical outer member which is connected to a first drive shaft and which is provided, on its inner wall surface, with a plurality of guide grooves spaced apart from each other by predetermined spacing distances and which extend along an axial direction, and an inner member which is connected to a second transmission shaft and which is inserted in an open interior space of the outer member, the universal constant speed coupling comprises: trunnions, each of which extends into the guide groove and each of which is provided with a spherical surface along a circumferential direction; first annular members, each of which is externally adjusted to the trunnion and each of which has a depression having a spherical surface formed on an inner circumferential surface to make surface-to-surface contact corresponding to the spherical surface; and second ring members, each of the P1720 / 99MX which externally adjusts to the first annular member via a bearing member and each of which is provided in a relatively displaceable manner with respect to the first annular member along an axial direction of the trunnion.
2. 2. The universal constant velocity coupling according to claim 1, wherein the stump is formed integrally with a neck section expanding from a ring-shaped spiral flange, a disk section having a flat upper surface, the The stump has a spherical surface formed on an outer circumferential surface that is substantially perpendicular to the upper surface.
3. 3. The universal constant velocity coupling according to claim 1 which is provided integrally with columnar journals and ring members, each of which is inserted into the die in a forced manner and each of which has a spherical surface formed in a circumferential surface, exterior. The universal constant velocity coupling according to claim 1, wherein a pair of mutually opposed cuts, each of which has a circular arc-shaped configuration and each of which continues towards the depression having a spherical surface , are formed on the inner circumferential surface of the first P1720 / 99MX ring member. The universal constant velocity coupling according to claim 1, wherein a non-circular cut, which continues towards the depression having the spherical surface and including a substantially elliptical configuration, is provided on the inner circumferential surface of the first annular member. The universal constant speed coupling according to claim 5, wherein the non-circular cut and the stump that fits into a hole of the first annular member via the cut are designed to satisfy the following expressions (1) to (3): R - Hsen? -? / R2 -R2 • eos? > 0 (1) wherein an angle of assembly is represented by?, a radius of the spherical surface of the trunnion is represented by R, a width of the spherical surface of the trunnion is represented by H, a short radius of cut of the first annular member is represented by r , a width of the first ring member is represented by P1720 / 99MX h, a radius of the trunnion is represented by d, a long width projected from the spherical surface of the trunnion, which is obtained when the angle of assembly is inclined by,, is represented by X and a short projected width of the surface spherical of the stump, which is obtained when the assembled angle is inclined by?, is represented by Y. 7. The universal constant velocity coupling according to claim 2, wherein the neck section is provided in a position deviated from a center of the spiral flange. The universal constant speed coupling according to claim 1, wherein the bearing member comprises a plurality of needle bearings that are supported on an inner circumferential surface of the second annular member, and the first annular member and the second annular member they are provided in a relatively displaceable manner along the axial direction of the trunnion according to a sliding action in the needle bearings. The universal constant velocity coupling according to claim 1, wherein the bearing member comprises a plurality of needle bearings that are supported on an outer, circumferential surface of the first annular member, and the first annular member and the second annular member are provided in a way P1720 / 99MX relatively displaceable along the axial direction of the trunnion according to a sliding action in the needle bearings. The universal constant velocity coupling according to claim 8, wherein the plurality of needle bearings are maintained on the inner circumferential surface of the second annular member due to a voussoir effect. 11. A universal constant velocity coupling having a cylindrical outer member which is connected to a first transmission shaft and which is provided, on its inner wall surface, with a plurality of guide grooves spaced apart by predetermined spacing distances and which extends along an axial direction, and an inner member which is connected to a second transmission shaft and which is inserted into an open interior space of the outer member, the universal constant speed coupling comprises: trunnions, each of which extends towards the guide groove and each of which includes a first curved surface and a second curved surface which are opposite each other, as well as a spherical surface surrounding the first curved surface and the second curved surface; first annular members, each of which adjusts externally to the stump and each of which has a depression that has a P1720 / 99MX spherical surface formed on an inner circumferential surface to make surface-to-surface contact corresponding to the spherical surface; second annular members, each of which externally adjusts to the first annular member via a bearing member and each of which is provided in a relatively displaceable manner with respect to the first annular member along an axial direction of the trunnion; and an attitude retention mechanism for maintaining an attitude of the second annular member so that the second annular member is substantially parallel to an axial direction of the outer member. The universal constant velocity coupling according to claim 11, wherein the trunnion is integrally formed with a neck section extending from a spiral ring-shaped rim, and a head section continuing to the neck section, a first curved surface, which is cut to have a circular arc-shaped cross section, is formed on an upper surface of the head section along the circumferential direction of the outer member, and a spherical surface is formed on a surface circumferential exterior that is continuous to the upper surface. P1720 / 99MX 13. The universal constant velocity coupling according to claim 11, wherein the attitude retention mechanism includes a pair of notches that mutually form opposite at both ends of a boundary section of the guide groove and extending along the axial direction of the outer member, and an annular projection that is formed along an outer circumferential surface of the second annular member, to engage with the notches. The universal constant velocity coupling according to claim 13, wherein the annular protrusion has a first coupling surface for coupling with the roof section having a circular arc-shaped cross-section to construct the guide groove and an annular surface. coupling to engage a substantially flat shoulder formed in the notch. The universal constant velocity coupling according to claim 11, wherein a non-circular cut continuing to the depression having the spherical surface and including a substantially elliptical configuration is provided on the inner circumferential surface of the first annular member. 16. The universal constant speed coupling according to claim 11, wherein a pair of mutually opposed cuts each having P1720 / 99MX a configuration in the form of a circular arc that continues towards the depression having the spherical surface, are formed on the inner circumferential surface of the first annular member. The universal constant velocity coupling according to claim 15, wherein the non-circular cut and the stump, which fits into a hole of the first annular member and the cut, are designed to satisfy the following expressions (1) to (3) ): - Hsen? -? / R2 -R2 • cos? > 0 (1) wherein an angle of assembly is represented by?, a radius of the spherical surface of the trunnion is represented by R, a width of the spherical surface of the trunnion is represented by H, a short radius of cut of the first annular member is represented by r , a width of the first annular member is represented by h, a radius of the trunnion is represented by d, a long width projected from the spherical surface of the trunnion, which is obtained when the assembly angle is inclined by,, is represented by X, and a short width P1720 / 99MX projected from the spherical surface of the core, which is obtained when the assembled angle is inclined by?, Is represented by Y. The universal constant velocity coupling according to claim 12, wherein the neck section is provided in a position deviated from a center of the spiral flange. The universal constant velocity coupling according to claim 11, wherein the outer member has a plurality of extended sections extending in the axial direction and forming and separating from each other at predetermined angles respectively around a central axis, and the outer member comprises a main body for forming the guide grooves between the adjacent expanded sections, and a cylindrical member for being externally adjusted to the expanded sections. The universal constant velocity coupling according to claim 11, wherein the bearing member comprises a plurality of needle bearings that are supported on an outer circumferential surface of the first annular member or on an inner circumferential surface of the second annular member, first annular member and second annular member are provided in a relatively displaceable manner along the axial direction of the trunnion according to P1720 / 99MX with a sliding action on the needle bearings. 21. The universal constant velocity coupling according to claim 11, wherein the plurality of needle bearings are maintained on the inner circumferential surface of the second annular member due to a voussoir effect. 22. The universal constant velocity coupling according to claim 1, wherein the trunnion has a neck section projecting radially outwardly from a ring-shaped spiral ridge and a head section continuing to the neck section, and in One side of the neck section forms a nape section, which extends towards the adjacent stump. 23. The universal constant velocity coupling according to claim 22, wherein the neck section is formed to have a curved transverse section tapering gradually towards the adjacent trunnion, as viewed from a side in the head section. 24. The universal constant velocity coupling according to claim 22, wherein the nape section is formed to have a rectangular cross-section as seen from one side of the head section. 25. The universal constant velocity coupling according to claim 11, wherein the trunnion has a neck section and protrudes P1720 / 99MX radially outwardly from a ring-shaped spiral flange, and on one side of the neck section a head section is formed which continues to the neck section and a nape section extending towards the adjacent stump. 26. The universal constant velocity coupling according to claim 25, wherein the nape section is formed to have a curved transverse section tapering toward the adjacent stump as seen from one side of the head section. 27. The universal constant speed coupling according to claim 25, wherein the neck section is formed to have a rectangular cross-section as seen from one side of the head section. 28. A method for assembling a universal constant speed coupling having a cylindrical outer member which is connected to a first transmission shaft and which is provided, on its inner wall surface, with a plurality of guide grooves spaced apart by distance of predetermined spacing and extending along an axial direction, and an inner member which is connected to a second drive shaft and which is inserted into an open interior space of the outer member, wherein on an inner circumferential surface of a first ring member P1720 / 99MX a pair of mutually opposite cuts are formed, each of which has a circular arc-shaped configuration, the method comprising the steps of: inserting a spherical surface of a stump into a depression having a spherical surface of the first annular member along the pair of cuts so that the stump is installed in a hole of the first annular member. The method for assembling the universal constant velocity coupling according to claim 28, wherein the stump is inserted into the depression having the spherical surface of the first annular member along a non-circular cut including a substantially elliptical shape formed on the inner circumferential surface of the first annular member. 30. A method for assembling the universal constant velocity coupling having a cylindrical outer member which is connected to a first transmission shaft and which is provided, on its inner wall surface, with a plurality of guide tracks spaced apart by distances of predetermined spa and extending along an axial direction, and an inner member which is connected to a second transmission shaft and which is inserted into an open interior space of the outer member, wherein a first curved surface, a second curved surface and a spherical surface that P1720 / 99MX encircles the first curved surface and the second curved surface are formed in a stump, while in an inner circumferential surface of the annular member a non-circular cut is formed which includes a substantially elliptical cutting configuration, the method comprising the step: tilting the stump at a predetermined angle with respect to the annular member to insert the spherical surface of the trunnion into a depression having a spherical surface of the annular member along a non-circular cut, so that the trunnion is installed in a hole in the annular member. The method for assembling the universal constant speed coupling according to claim 30, wherein the non-circular cut and the stump to be adjusted in the annular member hole by cutting are designed to satisfy the following expressions (1) a (3): R Hsen? -? / 2 -R2 • eos? > 0 (1) + r * sin) 90 ° - é cos s d > 0 (3) + h2 where an assembly angle is represented P1720 / 99MX by?, A radius of the spherical surface of the stump is represented by R, a width of the spherical surface of the stump is represented by H, a short radius of the cut of the first annular member is represented by r, a width of the first annular member is represented by h, a radius of the stump is represented by d, a long width projected from the spherical surface of the stump, which is obtained when the assembly angle is inclined by?, is represented by X, and a projected short width of the spherical surface of the stump, which is obtained when the assembled angle is inclined by?, is represented by Y. 32. The method for assembling the universal constant velocity coupling according to claim 30, wherein a pair of mutually a configuration in the form of a circular arc are formed in the inner circumferential surface of the annular member, and the spherical surface of the trunnion is inserted in the depression having the spherical surface. of the annular member along the pair of cuts so that the stump is installed in the annular member hole. P1720 / 99MX