JP4879501B2 - High angle fixed type constant velocity universal joint - Google Patents

Description

  The present invention relates to a high angle fixed type constant velocity universal joint. Constant velocity universal joints transmit torque at a constant angular speed by connecting the rotating shaft on the drive side and the rotating shaft on the driven side in the power transmission system of automobiles and various industrial machines. The slidable type allows angular displacement and axial displacement, whereas the fixed type allows only angular displacement.

  In general, a fixed type constant velocity universal joint includes an outer joint member that is coupled to a drive-side or driven-side shaft so as to be able to transmit torque, an inner joint member that is coupled to a driven-side or drive-side shaft so as to be able to transmit torque, and an outer joint A plurality of torque transmitting elements that transmit torque by being interposed between the member and the inner joint member, and a cage that holds the plurality of torque transmitting elements in a bisector of an angle formed by the drive shaft and the driven shaft. I have.

  In recent years, the wheelbase may be lengthened from the viewpoint of expanding the riding space of automobiles, but in order to prevent the vehicle turning radius from increasing accordingly, the fixed type used as a coupling joint for automobile drive shafts, etc. There is a need to increase the steering angle of the front wheels by increasing the angle of the constant velocity universal joint.

As a fixed type constant velocity universal joint to meet the needs of high angle, it has been proposed to taper the ball groove of the outer joint member and the bottom of the ball groove of the inner joint member that constitute the track on which the torque transmitting element rolls. (For example, refer to Patent Documents 1 to 3).
JP 2001-153149 A JP 2001-304282 A JP 2001-349332 A

  In the fixed type constant velocity universal joint disclosed in Patent Documents 1 to 3, the angle of the ball is easily increased by making the ball grooves of the outer joint member and the inner joint member into a tapered shape. However, there is a problem that the load (hereinafter referred to as pocket load) received by the pocket side wall of the cage in contact with the ball increases in proportion to the taper angle (see FIG. 9).

  The main purpose of the present invention is to make the ball groove of the fixed type constant velocity universal joint tapered so that the angle can be easily increased, and the cage can withstand the pocket load that increases along with it, thereby preventing early breakage. It is.

  The present invention verifies the force (especially pocket load) generated in the constant velocity universal joint by making the ball groove into a tapered shape among the internal specifications of the high angle fixed type constant velocity universal joint. The problem is solved by optimally setting the shape of the cage in consideration of the effect on the strength of the cage.

That is, the fixed type constant velocity universal joint of the present invention includes an outer joint member in which a plurality of ball grooves extending in the axial direction to the opening end are formed at equal intervals in the circumferential direction on the inner spherical surface, and an outer spherical surface in the axial direction. A plurality of balls that transmit torque by interposing between a ball groove of an outer joint member and a ball groove of an inner joint member that form a pair, and an inner joint member in which a plurality of extended ball grooves are formed at equal intervals in the circumferential direction And a cage that is interposed between the inner spherical surface of the outer joint member and the outer spherical surface of the inner joint member, and that includes pockets for accommodating balls in the circumferential direction,
The opening end side groove bottom of the ball groove of the outer joint member has a tapered shape linearly expanding toward the opening end,
The ball groove of the inner joint member has a taper shape in which the diameter of the outer joint member's non-opening end side groove is linearly expanded toward the anti-opening end side,
The outer spherical center and inner spherical center of the cage are offset to the opposite side by an equal distance in the axial direction with respect to the joint center.
The center of curvature of the ball groove of the outer joint member matches the center of the inner spherical surface, the center of curvature of the ball groove of the inner joint member matches the center of the outer spherical surface,
The ratio Do / d of the cage outer diameter Do to the ball diameter d is 3.9 to 4.1, and the ratio t / d of the cage thickness t to the ball diameter d is 0.31 to 0.34. The ratio w / d of the cage width w to the ball diameter d is 1.8 or more and 2.0 or less.

  The value Do / d of the ratio of the cage outer diameter Do to the ball diameter d was 3.7 ≦ Do / d ≦ 3.8 in the conventional fixed type constant velocity universal joint, but in the present invention, 3.9 ≦ Do. /D≦4.1. As the operating angle increases, the amount of movement of the ball in the radial direction within the pocket increases (see FIG. 3. In FIG. 3, the symbol m indicates the outermost diameter position where the ball and cage contact, and the symbol n indicates the ball and cage. Indicates the innermost diameter position that comes into contact). Since the ball contact point must not be disengaged from the cage even at the maximum operating angle, the lower limit of the cage outer diameter is inevitably determined. On the other hand, if the cage outer diameter is excessive, the ball groove depth of the outer joint member becomes insufficient and the durability deteriorates. Therefore, the outer diameter dimension that can ensure the minimum durability is the upper limit value of the cage outer diameter.

  The value of the ratio of the cage thickness t to the ball diameter d was 0.24 ≦ t / d ≦ 0.27 in the conventional fixed type constant velocity universal joint, but in the present invention, 0.31 ≦ t / d ≦ 0.34. The cage wall thickness t can be defined by the outer diameter determined from the above Do / d and the inner diameter described later. The concept for defining the inner diameter is the same as in the case of Do / d, and the upper limit value is determined from the viewpoint of securing the contact point of the ball, and the lower limit value secures the ball groove depth of the inner joint member, that is, durability. It is determined from the viewpoint.

  The value w / d of the ratio of the cage width w to the ball diameter d is 1.7 ≦ w / d ≦ 1.9 in the conventional fixed type constant velocity universal joint, but in the present invention, 1.8 ≦ w / d. d ≦ 2.0. In order to set the stress value of the pocket side wall under the increased pocket load of the cage to be equal to or less than that of the conventional high angle fixed type constant velocity universal joint (UJ), it is necessary to secure the section modulus of the pocket side wall. Since the inner diameter is determined by the above Do / d and t / d, it is adjusted by the width dimension. At this time, by setting the lower limit value to the width dimension where the stress value is equivalent to that of the conventional fixed type constant velocity universal joint (UJ), the strength equal to or higher than that of the conventional high angle fixed type constant velocity universal joint (UJ) can be secured. become. Also, if the width dimension is set excessively, the weight and material cost increase, so the upper limit value is set to the same range as the conventional high angle fixed type constant velocity universal joint from the lower limit value (standard specified range). .

  According to a second aspect of the present invention, in the high angle fixed type constant velocity universal joint of the first aspect, the taper angle of the ball grooves of the outer joint member and the inner joint member is 12 deg or less. While ensuring strength and durability, which are the basic performances required in the past, studies were conducted using internal force analysis and finite element method (FEM) analysis, and the taper angle range was narrowed down and optimally set. And the consistency with the evaluation result and analysis result of the sample which changed the taper angle was confirmed. By forming the ball groove in a tapered shape, the outer joint member can be easily increased without increasing the outer diameter of the outer joint member. In order to avoid reducing the strength and workability of the high angle fixed constant velocity universal joint, the influence and tendency of the ball groove being tapered in the internal specifications of this high angle fixed type constant velocity joint are verified. The upper limit was defined as 12 °.

  According to a third aspect of the present invention, in the high angle fixed type constant velocity universal joint according to the first or second aspect, the outer spherical center and the inner spherical center of the cage are offset to the opposite side by an equal distance in the axial direction with respect to the joint center. (This offset is referred to as a cage offset.) The amount of the offset f is a line segment connecting the center of curvature of the ball groove of the outer joint member or the center of curvature of the ball groove of the inner joint member and the center of the ball. The ratio value f / PCR with the length PCR is in the range of 0.018 or more and 0.150 or less.

  Since the cage offset amount f is related to the thickness difference in the longitudinal section of the cage, it is desirable to set the cage offset amount f in consideration of this point. For example, by setting the cage offset amount f large, there is an advantage that the strength can be improved by increasing the thickness of the cage on the opening end side of the outer joint member as in the invention of claim 4. Further, by increasing the thickness of the cage on the opening end side of the outer joint member, the ball that is about to jump out from the opening end of the outer joint member can be restrained by the cage when the operating angle is taken.

  However, if the cage offset amount f is too large, the amount of movement of the ball in the cage pocket in the circumferential direction increases, and it is necessary to increase the circumferential dimension of the cage pocket in order to ensure proper movement of the ball. The pillar portion of the cage becomes thin, and the strength becomes a problem. Further, the thickness of the cage on the back side of the outer joint member, that is, the side opposite to the opening end is reduced, and the strength is problematic.

  Thus, it is not preferable that the cage offset amount f is excessive, and there exists an optimum range in which the significance of providing the cage offset amount f and the above-described strength can be balanced. However, since the optimum range of the cage offset amount f varies depending on the size of the joint, it needs to be determined in relation to the basic dimension representing the size of the joint. Therefore, if the value f / PCR of the ratio of the cage offset amount f to the length PCR of the line segment connecting the center of curvature of the ball groove of the outer joint member or the center of curvature of the ball groove of the inner joint member and the center of the ball is used. The cage offset amount f is desirably set so that f / PCR is in the range of 0 to 0.12.

  If f / PCR is larger than 0.12, the above-mentioned problem in strength occurs. On the contrary, if it is smaller than 0, it is not meaningful to provide the cage offset amount f. That is, cage offset is one of the objectives to prevent the ball from jumping out of the cage pocket at a high operating angle, but the objective cannot be achieved within a range smaller than zero. Therefore, from the viewpoint of securing cage strength and durability, the range in which f / PCR is 0 or more and 0.12 or less is the optimum range of the cage offset amount f.

Oite to claim 1, the consistent curvature center and the inner spherical surface center of the ball groove in the outer joint member, the center of curvature of the ball grooves of the inner joint member coincides with the center of the outer spherical surface, so-called track offset Means no . When the center of curvature of the ball groove of the outer joint member is offset with respect to the center of the inner spherical surface, and the center of curvature of the ball groove of the inner joint member is offset with respect to the center of the outer spherical surface in the opposite direction in the axial direction ( This offset is called a track offset.) Since the ball groove becomes shallower toward the back side of the outer joint member, the ball located at the innermost part of the outer joint member when the operating angle is taken is There is a risk of riding on the shoulder. By eliminating this track offset, the ball groove does not become shallow even on the back side of the outer joint member, and therefore it is possible to suppress the climbing of the ball located at the innermost part of the outer joint member even when the operating angle is taken. .

  According to the present invention, the cage can withstand the increased pocket load well and prevent early breakage, so that the ball groove of the fixed type constant velocity universal joint can be tapered to easily achieve high angle. it can.

  Embodiments of the present invention will be described below with reference to the drawings.

  The fixed type constant velocity universal joint shown in FIG. 1 includes an outer ring 10, an inner ring 20, a ball 30, and a cage 40 as main components. If the two shafts to be connected by the fixed type constant velocity universal joint are called a first rotating shaft and a second rotating shaft, the first rotating shaft is connected to the outer ring 10 and the second rotating shaft is connected to the inner ring 20. In this way, torque is transmitted at a constant speed even when both are angled. FIG. 2 shows an enlarged main part of FIG. Further, FIG. 3 shows a state where the rotation axis X of the outer ring 10 and the rotation axis Y of the inner ring 20, that is, the operating angle θ is maximum (for example, 52 ° or more), and FIG. 1 shows a state where the operating angle θ is 0 °. Is shown.

  The outer ring 10 as an outer joint member includes a mouth portion 16 and a stem portion (not shown), and is coupled to the first rotating shaft so that torque can be transmitted at the stem portion. The mouse portion 16 has a bell shape opened at one end, and a plurality of ball grooves 14 extending in the axial direction are formed at equal intervals in the circumferential direction on a concave spherical inner peripheral surface (hereinafter referred to as an inner spherical surface) 12. It is. The ball groove 14 extends to the open end 18 of the mouse portion 16.

  An inner ring 20 as an inner joint member has a convex spherical outer peripheral surface (hereinafter referred to as an outer spherical surface) 22, and a plurality of ball grooves 24 extending in the axial direction are arranged on the outer spherical surface 22 at equal intervals in the circumferential direction. It is formed. The ball groove 24 is cut in the axial direction of the inner ring 20. The inner ring 20 has a spline (or serration) hole 26 for coupling with the second rotating shaft so as to transmit torque.

  The ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 form a pair, and one ball 30 as a torque transmitting element is incorporated in a rollable manner, one on each track constituted by the pair of ball grooves 14 and 24. It is. The ball 30 is interposed between the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 to transmit torque. Each ball 30 is accommodated in a pocket 46 disposed in the circumferential direction of the cage 40. The number of balls 30, and thus the number of ball grooves 14, 24, is arbitrary, but is 6 or 8 for example.

The cage 40 is slidably interposed between the outer ring 10 and the inner ring 20, is in contact with the inner spherical surface 12 of the outer ring 10 at the outer spherical surface 42, and is in contact with the outer spherical surface 22 of the inner ring 20 at the inner spherical surface 44. The center of curvature of the inner spherical surface 12 of the outer ring 10 and the center of curvature of the outer spherical surface 42 of the cage 40 coincide with each other, and are denoted by reference numeral O ₄ in FIG. Similarly, the center of curvature of the outer spherical surface 22 of the inner ring 20 coincides with the center of curvature of the inner spherical surface 44 of the cage 40, and is indicated by reference numeral O ₃ in FIG. In the drawing, the clearance between the inner spherical surface 12 of the outer ring 10 and the outer spherical surface 42 of the cage 40 and the clearance between the outer spherical surface 22 of the inner ring 20 and the inner spherical surface 44 of the cage 40 are exaggerated.

  The ball groove 14 of the outer ring 10 includes an arc portion 14a and a straight portion 14b. The arc portion 14a is positioned on the back side of the mouse portion 16, that is, on the side opposite to the opening end, and the linear portion 14b is positioned on the opening end 18 side. The ball groove 14 has a tapered shape with a taper angle α that linearly expands the groove bottom on the opening end 18 side toward the opening end 18.

  The ball groove 24 of the inner ring 20 includes an arc portion 24a and a straight portion 24b. The arc portion 24a is located on the opening end 18 side of the outer ring 10, and the straight portion 24b is located on the opposite opening end side. The ball groove 24 has a tapered shape with a taper angle α that linearly expands the groove bottom on the back side, that is, the opposite end face side of the outer ring 10 toward the opposite end face side.

In this embodiment, in order to obtain a structure that can have a large operating angle θ, the center of curvature O ₁ of the ball groove 14 of the outer ring 10 is set to the inner ring 20 with respect to the center O ₃ of the inner spherical surface 12 as shown in FIG. The center of curvature O ₂ of the ball groove 24 is offset from the center O ₄ of the outer spherical surface 22 in the axial direction opposite to each other by an equal distance F (track offset).

Similarly, the center of curvature O ₃ center of curvature O ₄ and the inner spherical surface 44 of the outer spherical surface 42 of the cage 40 is equal distance f with respect to the joint center O, are allowed to offset in opposite directions in the axial direction (cage offset ).

  As shown in FIG. 3, when the rotation axis X of the outer ring 10 and the rotation axis Y of the inner ring 20 take a certain operating angle θ other than 0 °, a bisector of the angle θ formed by both the rotation axes X and Y If all the balls 30 are in the vertical plane, that is, the joint center plane P, the distances from the ball center to the two rotation axes X and Y are equal to each other. Transmission takes place. The intersection of the joint center plane P and the rotation axes X and Y is referred to as a joint center O. In the fixed type constant velocity universal joint, the joint center O is fixed regardless of the operating angle θ.

  The track formed by the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 that form a pair has a wedge shape that gradually expands from the back side of the mouth portion 16 of the outer ring 10 toward the opening end 18 side. . Then, when the torque is transmitted with the joint at the operating angle θ, as shown by the white arrow in FIG. 2, a thrust for pushing the ball 30 from the narrow side to the wide side of the wedge-shaped track is applied. To do. A load that acts on the wall surface of the pocket 46 of the cage 40 from the ball 30 by this thrust is called a pocket load.

When the maximum operating angle (for example, 52 ° or more) is taken, the cage offset amount f is set to be larger than that of the conventional one so that the ball 30 about to jump out of the open end 18 of the mouth portion 16 of the outer ring 10 can be restrained by the cage 40. Set larger. The radius of the center locus of the ball 30, that is, the length of the line segment connecting the center of curvature O ₁ of the ball groove 14 of the outer ring 10 or the center of curvature O ₂ of the ball groove 24 of the inner ring 20 and the center O _{5 of the} ball 30 is represented by PCR. Then, the value f / PCR of the ratio of the cage offset amount f to the PCR is set to be 0.12 or less.

  In the longitudinal section of the joint, the ball bottoms of the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 are tapered to increase the maximum operating angle, and in addition to the ball 30 in the ball groove 14 of the outer ring 10, Therefore, stable torque transmission between the outer ring 10 and the inner ring 20 is achieved. Further, since the track load and the pocket load of the phase (phase angle φ = 0 °) (see FIGS. 3 and 4) in which the ball 30 is most likely to jump out when the operating angle θ is taken, it is advantageous in a high angle region. is there. The track load means a load received by the wall surfaces of the ball grooves 14 and 24 from the ball 30 in contact.

  Since the outer spherical surface 42 of the cage 40 is contact-guided to the inner spherical surface 12 of the outer ring 10 and the inner spherical surface 44 of the cage 40 is contact-guided to the outer spherical surface 22 of the inner ring 20, the cage 40 and the outer ring 10 or A spherical force (force that pushes between the spherical surfaces) acts with the inner ring 20, but the maximum value of the spherical force is reduced, leading to suppression of heat generation inside the joint. Furthermore, since the forging die has a shape that can be easily removed, workability by cold forging is good, and the manufacturing cost can be reduced.

  By making the groove bottoms of the ball grooves 14 and 24 of the outer ring 10 and the inner ring 20 into a tapered shape, the influence on the internal force consisting of the aforementioned track load, pocket load and spherical force and its tendency are verified, and the finite element method ( FEM) was performed, and the range of the taper angle α was narrowed down and optimally set. First, the tendency as shown in Table 1 is recognized in the internal force by increasing the taper angle α. In Table 1, the phase at which the ball 30 is most likely to jump out (phase angle φ = 0 °) and the phase of the ball 30 at which the internal force reaches its maximum value (for example, the vicinity of the phase at which the ball 30 is deepest (phase angle). (φ = 180 °)). Further, the fluctuation range of the spherical force means a difference between the maximum value and the minimum value of the spherical force.

  As is apparent from Table 1, when the taper angle α is increased, the maximum value of the pocket load increases, but the meat of the outer ring 10 is near the phase where the ball 30 enters the innermost part of the outer ring 10 (phase angle φ = 180 °). Since the strength of the outer ring 10 and the cage 40 can be ensured by increasing the thickness and increasing the cage offset amount f to increase the thickness of the cage 40, there is no problem.

  Next, a finite element method (FEM) analysis was performed to determine the upper limit value of the taper angle α. When the taper angle α is increased, the internal force (track load and pocket load) is reduced at the phase (phase angle φ = 0 °) in which the ball 30 is most likely to jump out, which is advantageous in terms of strength. Since the thickness of the open end 18 is small, the stress value generated in the ball groove 14 is converted into joint strength to confirm the tendency. The result is as shown in FIG. As is apparent from the figure showing the relationship of the joint strength to the taper angle α (deg), the joint angle is less than the required strength when the taper angle α is 12.9 °. Was defined as 12 °.

  In the above-described embodiment, the case where the track offset is provided is illustrated, but the track offset may not be provided. In other words, when the track offset is provided, the arc portion 14a located on the back side of the mouse portion 16 in the ball groove 14 of the outer ring 10 becomes shallower toward the back side. There is a possibility that the ball 30 located at the innermost part of the ball 14 rides up. Therefore, by setting the track offset amount to 0, the arc portion 14a located on the back side of the mouse portion 16 in the ball groove 14 of the outer ring 10 has a uniform depth. It is possible to suppress the riding of the ball 30 located at the innermost position of the ball groove 14.

  The results of the internal force analysis performed by varying each factor of the track offset amount F, the cage offset amount f, and the taper angle α will be described below. Here, with respect to the track offset, the track offset amount F = 0, that is, “no track offset” is set in consideration of the characteristics of the ultra-high angle fixed type constant velocity universal joint in which the allowable load torque does not drop even when entering the high angle region. The cage offset should be as small as possible from the viewpoint of internal force. However, to ensure the function of the joint, a certain amount of cage offset must be provided, so that 0 ≦ f / PCR ≦ 0.150 is varied. It was. The taper angle α was varied in the range from 0 deg to 12 deg.

  If f = 0 (f / PCR = 0), the track load and the pocket load in the 0 deg phase become zero when the taper angle α is 1.1 deg or more.

  On the other hand, when the taper angle α = 12 deg, the track load and the pocket load in the 0 deg phase become zero when f = 3.94 (f / PCR = 0.114) or less.

  That is, if the relationship between the cage offset amount f and the taper angle α is set within the hatched region in FIG. 6, the track load and the pocket load in the 0 deg phase become zero. Here, FIG. 6 is plotted based on data calculated by internal force analysis, and the horizontal axis represents the taper angle α (deg) and the vertical axis represents f / PCR.

As a result, the internal specifications that are advantageous in a higher angle operating range by reducing the load applied to the 0 deg phase as much as possible are as follows.
Track offset: None Cage offset amount f: f / PCR ≦ 0.12
Taper angle α: 1deg ≦ α ≦ 12deg

  In this embodiment, while the load at the 0 deg phase is reduced, the peak load is larger than that of the conventional constant velocity universal joint. Therefore, in order to ensure strength, the thick portion of the cage 40 is used as the outer ring. 10 is preferably arranged toward the opening end 18 side.

  For the fixed type constant velocity universal joint according to the present invention (example) and the conventional UJ type high angle fixed type constant velocity universal joint (comparative example) with dimensions set according to the above internal specifications, the maximum pocket load at 0 deg phase is loaded. When the stress value of the side wall 48 of the cage 40 was analyzed, the result was as shown in FIG. The working angle is set higher in the example (56 °) than in the comparative example (50 °). The percentage display is based on the stress value of the comparative example being 100. As described above, since the example has a lower stress than the comparative example, it can be determined that the cage having the dimensional specifications exhibits a cage strength equal to or higher than that of the comparative example at a larger operating angle.

  Next, for the comparative example and the example, the effect and tendency of internal force (especially pocket load) due to the taper of the ball groove was verified and compared. As a result, the phase at which the ball protrudes most at the maximum operating angle (phase) The pocket load at the angle of 0 deg) could be greatly reduced, but when pocket loads of all other phases were confirmed, the pocket load (maximum value) of the comparative example was 4671 N, whereas the pocket load of the example was The (maximum value) was 5939N. Thus, the maximum value of the pocket load is increased by about 30% in the example compared to the comparative example (see FIG. 8). The load torque at this time is the same, but the maximum operating angle is different, and the example (56 °) is set at a higher angle than the comparative example (50 °). Table 2 shows the specifications in the comparative examples and examples.

  The increase in the maximum pocket load is due to the taper of the ball groove and the increase in the maximum operating angle. The following settings are adopted as a cage specification that can withstand this increased pocket load and prevent premature breakage. The values in parentheses are values in the conventional fixed type constant velocity universal joint (BJ) and high angle fixed type constant velocity universal joint (UJ). The outer diameter Do, the inner diameter Di, and the width w of the cage are as shown in FIG. 2, but the thickness t of the cage is the thickness at the center in the axial direction.

Ratio value of cage outer diameter Do to ball diameter d Do / d:
3.9 ≦ Do / d ≦ 4.1 (3.7 ≦ Do / d ≦ 3.8)
Ratio value of cage thickness t to ball diameter d t / d:
0.31 ≦ t / d ≦ 0.34 (0.24 ≦ t / d ≦ 0.27)
Ratio w / d of cage width w to ball diameter d:
1.8 ≦ w / d ≦ 2.0 (1.8 ≦ w / d ≦ 1.9)

The value Di / d of the ratio of the cage inner diameter Di to the ball diameter d is determined by the cage outer diameter and the wall thickness, but for reference, it is as follows:
3.25 ≦ Di / d ≦ 3.45 (3.10 ≦ Di / d ≦ 3.25)

  At this time, since the direction in which the pocket load acts is the direction from the inner part of the outer ring toward the opening end, the thick side of the cage is disposed on the opening end side. Note that the back side of the mouse part of the cage is thin. This is because it is necessary to provide an inlay diameter for incorporating the inner ring. Since the pocket load in the direction from the opening end side of the outer ring to the back side of the mouse portion is relatively small, no particular problem occurs.

It is a longitudinal cross-sectional view of the fixed type constant velocity universal joint which shows embodiment of this invention. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows the state which the joint of FIG. 1 took the maximum operating angle. It is a cross-sectional view of a cage containing a ball. It is a diagram which shows the taper angle of a ball groove, and the relationship between joint strength. It is a diagram which shows the relationship between a taper angle and f / PCR. It is a graph which shows the stress value of the pocket side wall when a maximum pocket load is applied in comparison with a comparative example and an Example. It is a graph which compares and shows a pocket load (maximum value) with a comparative example and an Example. It is a diagram which shows the relationship between a taper angle and a pocket load.

Explanation of symbols

10 outer ring 12 inner spherical surface 14 ball groove 16 mouse part 18 open end 20 inner ring 22 outer spherical surface 24 ball groove 26 spline (or serration) hole 30 ball 40 cage 42 outer spherical surface 44 inner spherical surface 46 pocket α taper angle

Claims (4)

An outer joint member in which a plurality of ball grooves extending in the axial direction to the opening end are formed on the inner spherical surface at equal intervals in the circumferential direction, and a plurality of ball grooves extending in the axial direction on the outer spherical surface at equal intervals in the circumferential direction. The formed inner joint member, a plurality of balls that are interposed between the ball groove of the outer joint member and the ball groove of the inner joint member that form a pair, the inner spherical surface of the outer joint member, and the inner joint member A cage interposed between the outer spherical surface and a pocket for accommodating the ball in the circumferential direction;
The opening end side groove bottom of the ball groove of the outer joint member has a tapered shape linearly expanding toward the opening end,
The ball groove of the inner joint member has a taper shape in which the diameter of the outer joint member's non-opening end side groove is linearly expanded toward the anti-opening end side,
The outer spherical center and inner spherical center of the cage are offset to the opposite side by an equal distance in the axial direction with respect to the joint center.
The center of curvature of the ball groove of the outer joint member matches the center of the inner spherical surface, the center of curvature of the ball groove of the inner joint member matches the center of the outer spherical surface,
The ratio Do / d of the cage outer diameter Do to the ball diameter d is 3.9 to 4.1, and the ratio t / d of the cage thickness t to the ball diameter d is 0.31 to 0.34. A high-angle fixed type constant velocity universal joint characterized in that the value w / d of the ratio of the cage width w to the ball diameter d is 1.8 or more and 2.0 or less. 2. The high angle fixed type constant velocity universal joint according to claim 1, wherein the taper angle of the ball grooves of the outer joint member and the inner joint member is 12 deg or less. The center of the outer spherical surface and the center of the inner spherical surface of the cage are offset to the opposite side by an equal distance in the axial direction with respect to the joint center, and the amount of the offset f is the center of curvature of the ball groove of the outer joint member or the inner joint member. The ratio value f / PCR of the length PCR of the line segment connecting the center of curvature of the ball groove and the center of the ball is in the range of 0.018 or more and 0.150 or less. High angle fixed type constant velocity universal joint. 4. A high angle fixed type constant velocity universal joint according to claim 3, wherein the thick side of the cage is positioned on the opening end side of the outer joint member.

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