JP2006275168A - Drive shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance sealing property and durability of boots installed in a constant velocity universal joint of a drive shaft. <P>SOLUTION: This drive shaft is composed of a sliding type constant velocity universal joint J<SB>1</SB>attached with thermoplastic elastomer boots 10, a fixed type constant velocity universal joint J<SB>2</SB>attached with thermoplastic elastomer boots 10', and an intermediate shaft S for connecting both joints J<SB>1</SB>and J<SB>2</SB>. A large diameter installation part installed in an outside joint member of the boots 10 installed in the slide type constant velocity universal joint J<SB>1</SB>, is formed in a non-cylindrical shape of making a thin part and a thick part alternately appear in the circumferential direction, and has an outer peripheral surface of a cylindrical shape and an inner peripheral surface of a non-cylindrical shape along a boots installing part of the outside joint member, and the whole volume of the large diameter installation part is satisfied by a boots material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive shaft that transmits power by connecting a differential side and a wheel side of an automobile.

  A constant velocity universal joint is used for a differential shaft and a wheel side of a drive shaft of an automobile. The constant velocity universal joint has a type that can take a large operating angle of θ = 45 to 50 deg (for example, a fixed type constant velocity universal joint using a ball such as a Rzeppa type or a barfield type), and the operating angle is so much. There is a type (for example, a sliding type constant velocity universal joint such as a double offset type, a tripod type, and a cross groove type) that cannot be taken large but has a mechanism that slides in the axial direction of the outer joint member. Usually, a fixed type constant velocity universal joint is used on the wheel side, and a sliding type constant velocity universal joint is used on the differential side.

  The constant velocity universal joint is used with a boot attached for the purpose of preventing leakage of grease sealed inside and entry of foreign matter from the outside. This boot has a large-diameter mounting portion attached to a boot mounting portion provided on an outer joint member of a constant velocity universal joint, a small-diameter mounting portion attached to a boot mounting portion provided on a shaft connected to the constant velocity universal joint, And a bellows part that connects the two together. Rubbers such as chloroprene and thermoplastic elastomers are widely used for constant velocity universal joint boots. Generally, a thermoplastic elastomer boot is used on the wheel side, and a chloroprene rubber boot is used on the differential side. Alternatively, a thermoplastic elastomer boot may also be used on the differential side.

The shape of the outer joint member of the sliding type constant velocity universal joint used on the differential side may be a cylindrical shape or a non-cylindrical shape. There are many cases where it is more efficient to apply the non-cylindrical shape considering the internal structure from the viewpoint of weight reduction and workability of the constant velocity universal joint. When a cylindrical outer joint member is used, a thermoplastic elastomer boot can be applied. However, a chloroprene rubber boot is mainly used as a constant velocity universal joint boot applied to a non-cylindrical outer joint member. It has been. On the other hand, recently, it has been studied to apply a thermoplastic elastomer boot to a non-cylindrical outer joint member (see Patent Documents 1 to 5).
Japanese Patent Laid-Open No. 10-110738 Japanese Patent Laid-Open No. 10-196673 JP 2002-13546 A JP 2003-194093 A JP 2003-329057 A

  Chloroprene rubber boots have relatively good performance as constant-velocity universal joint boots, but have aspects such as fatigue resistance, wear resistance, low temperature resistance, heat aging resistance, and grease resistance (oil resistance). However, since it may not be sufficient depending on the use conditions, it tends to be replaced with a thermoplastic elastomer boot having better performance. In particular, the fixed type constant velocity universal joint used on the wheel side is rapidly replaced because most outer joint members have a cylindrical shape. However, the sliding type constant velocity universal joints used on the differential side are not often replaced because there are many outer joint members with a non-cylindrical contour considering the internal structure from the viewpoint of weight reduction and workability. Without progressing, chloroprene rubber boots continue to be used. In order to adapt to a non-cylindrical outer joint member, the large-diameter mounting portion of the boot is formed into a non-cylindrical shape in which a thick portion and a thin portion are alternately formed in the circumferential direction, and complicated including the axial direction. However, it is difficult to mold the thermoplastic elastomer boot. Alternatively, since the thermoplastic elastomer is slightly poor in elasticity and high in material hardness due to material properties, it may be difficult to attach the boot to the outer joint member or the sealing performance may be insufficient.

  When a thermoplastic elastomer boot is applied to a non-cylindrical outer joint member, the non-cylindrical outer joint member and the large-diameter mounting portion of the cylindrical boot or a non-cylindrical shape are formed. A large-diameter mounting portion of the boot is formed into a non-cylindrical shape along the outer joint member with respect to the outer joint member, and an intermediate member (bushing) is formed between the outer surface of the large-diameter mounting portion of the boot and the band that forms the non-cylindrical shape. ) May be used. However, in this embodiment, the number of parts increases, which is not preferable in terms of management and assembly process. Furthermore, the cost increases. Or since a certain amount of thickness is required for a bushing, an outer diameter dimension becomes large. Furthermore, the sealing properties at the contact portions between the outer joint member / boot and between the boot / bushing are insufficient.

  On the other hand, it is also considered that the large-diameter mounting portion of the boot is formed into a shape along the outer joint member that forms a non-cylindrical shape with a substantially constant thickness, and the boot outer surface is tightened with a band shaped along the non-cylindrical shape. However, since the band has a complicated shape, the cost increases and the sealing performance is insufficient.

  As another means, the shape of the inner surface of the large-diameter mounting portion of the boot is a shape along the shape of the outer joint member forming a non-cylindrical shape, and the outer surface of the large-diameter mounting portion of the boot is a thick-walled portion as a cylindrical boot. A boot made of a thermoplastic elastomer having a shape provided with a hollow portion has been devised (see FIG. 2 of Patent Document 5), but this shape has a problem that the sealing performance is insufficient.

  The drive shaft of the present invention comprises a fixed type constant velocity universal joint fitted with a thermoplastic elastomer boot, a sliding type constant velocity universal joint fitted with a thermoplastic elastomer boot, and an intermediate shaft connecting the two joints. The large-diameter mounting part attached to the outer joint member of the boot attached to the sliding constant velocity universal joint is a non-cylindrical shape in which thin and thick parts appear alternately in the circumferential direction, and the cylindrical outer periphery And a non-cylindrical inner peripheral surface along the boot mounting portion of the outer joint member, and the entire volume of the large-diameter mounting portion is filled with the boot material.

  According to the present invention, the durability is improved as compared with the boot made of chloroprene rubber, and the sufficient sealing performance can be secured, so that the reliability of the boot performance is improved. Furthermore, the weight of the boot can be reduced by not using a bushing and by minimizing the number of parts and reducing the weight of the boot compared to a boot made of chloroprene rubber. The drive shaft can be further reduced in weight by being used in combination with a hollow shaft as in the second aspect of the invention. In addition, since it is superior in impact resistance compared to chloroprene rubber boots, the handleability of the drive shaft during transportation is improved.

  Hereinafter, an embodiment will be described by taking as an example a case where it is applied to a tripod type constant velocity universal joint provided with a boot made of a thermoplastic elastomer.

FIG. 1 includes a differential-type sliding constant velocity universal joint J ₁ , a wheel-side fixed constant velocity universal joint J _2, and an intermediate shaft S that connects inner joint members of the constant velocity universal joints. The drive shaft of a motor vehicle is illustrated. In the illustrated embodiment, the intermediate shaft S is made hollow to reduce the weight. The hollow shaft may be formed by joining connection elements to both ends of the pipe of the intermediate part by welding or pressure welding, but it is preferable to integrally process the intermediate part and the connection element in order to further reduce the weight. As the processing method, the end portion of the pipe formed from steel material may be processed to form a connecting element, or the whole steel raw pipe such as an electric-welded pipe or seamless pipe is processed by plastic working. You may make it.

Fixed type constant velocity universal joint J ₂ of the wheel-side here is Yes and exemplified Tsueppa type, are provided with a boot 10 '. The fixed type constant velocity universal joint is mounted with a thermoplastic elastomer boot having a large-diameter mounting portion having a cylindrical shape on the inner peripheral surface and the outer peripheral surface. Thereby, the reliability of boot performance improves compared with the boot made from the chloroprene rubber conventionally used.

As shown in FIGS. 2 and 3, the differential sliding constant velocity universal joint J ₁ includes an outer joint member 2, a tripod member 4 as an inner joint member, and a roller 6 as a torque transmission element. It is a constituent element and further includes a boot 10.

  In the illustrated embodiment, the outer joint member 2 includes a mouth portion 22 and a stem portion 26 that are integrally formed. The stem portion 26 is coupled to a first rotating shaft (not shown) by a spline or serration shaft 28 formed at an end portion so as to transmit torque. The mouse portion 22 has a cup shape opened at one end, and a track groove 24 extending in the axial direction is formed at a position of the inner circumference in three equal parts. The outer peripheral surface of the mouse part 22 has a non-cylindrical shape in which the large diameter part 22a and the small diameter part 22b appear alternately when viewed in cross section (FIG. 3). In this embodiment, the large-diameter portion 22 a is a convex arc-shaped portion corresponding to the track groove 24, and the small-diameter portion is a concave arc-shaped portion corresponding to a portion between the adjacent track grooves 24.

  The tripod member 4 includes a boss 42 and a leg shaft 46. The boss 42 is formed with a spline or serration hole 44 that is coupled to the intermediate shaft S, which is the second rotating shaft, so as to be able to transmit torque. The leg shaft 46 projects in the radial direction from the circumferentially divided position of the boss 42. Each leg shaft 46 of the tripod member 4 carries a roller 6. A plurality of needle rollers 8 are interposed between the leg shaft 46 and the roller 6, and the roller 6 is rotatable about the axis of the leg shaft 46. In FIG. 1 and FIG. 2, a retaining ring and a washer for preventing the roller 6 from falling off are omitted. Here, a single roller type in which one roller 6 is supported on one leg shaft 46 is illustrated, but a double roller type including inner and outer rollers that are relatively rotatable is also possible.

  FIG. 4 shows a longitudinal section of the large diameter portion 22 a of the mouse portion 22. As shown in the drawing, a boot groove 30 extending in the circumferential direction is formed in the vicinity of the end portion. The vicinity of the boot groove 30 is referred to as a boot mounting portion of the outer joint member. The bottom surface of the boot groove 30 has a partial cylindrical shape, and is a straight line parallel to the axis in the longitudinal section. A protruding portion 32 is formed over part or all of the circumferential direction of the large diameter portion 22a. The protrusion 32 is preferably located near the end surface 38 of the outer joint member 2.

  In the case of the illustrated embodiment, both sides of the protrusion 32 in the axial direction are inclined surfaces 34 and 36. The inclination angles of the inclined surfaces 34 and 36 with respect to the axis are 25 ° or more and 60 ° or less, preferably 25 ° or more and 45 ° or less. Thereby, the turning efficiency of the outer joint member 2 is improved, and at the same time, the mounting property when the large-diameter mounting portion 12 of the boot 10 is fitted to the outer joint member 2 is improved, and the outer joint member 2 after the boot is mounted. It is also possible to improve the action of preventing the boot 10 from coming off and the position stability.

  If the angle of the first inclined surface, that is, the inclined surface 34 opposite to the end surface 38 of the outer joint member 2 is larger than 60 °, the workability of the boot mounting portion of the outer joint member 2 is deteriorated. On the other hand, when the angle is less than 25 °, the action of preventing the boot 10 from coming off in the axial direction after being fitted to the outer joint member 2 and the position stability are lowered. Moreover, since it becomes a protrusion long in an axial direction, the full width of the boot attachment part of the outer joint member 2 will become large, and it is unpreferable on space efficiency or intensity | strength. When the angle of the second inclined surface, that is, the inclined surface 36 on the end surface 38 side of the outer joint member 2 is larger than 60 °, the boot mounting property is hindered. On the other hand, when the angle is less than 25 °, the protrusion 32 is elongated in the axial direction, so that the entire width of the boot mounting portion is increased, which is not preferable in terms of space efficiency and strength.

  As shown in FIG. 5, the overall appearance of the boot 10 has a truncated cone shape, and includes a large-diameter attachment portion 12, a small-diameter attachment portion 14, and a bent portion 16 therebetween. The large-diameter mounting portion 12 is fitted to the outer joint member 2 and the small-diameter mounting portion 14 is fitted to the intermediate shaft S, and is fastened and fixed by boot bands 13 and 15, respectively (FIG. 1). . For this reason, the band groove | channel 18 for receiving the boot bands 13 and 15 is formed in the outer periphery of each attaching part. The bottom surface of the band groove 18 has a cylindrical surface shape, and the longitudinal section is parallel to the axis.

  The boot 10 is made of a thermoplastic elastomer, and every part is filled with the thermoplastic elastomer, and there are no voids. In particular, if there is a gap in the attachment portion, the tightening force of the band 13 (see FIG. 2) is not sufficiently transmitted to the boot attachment portion of the outer joint member 2, and the sealing performance is impaired. Examples of materials that can be employed include thermoplastic polyester elastomers having a type D durometer hardness of 35 to 50 in accordance with JIS K 6253. A rubber material having a type A durometer hardness of 50 or more and 70 or less according to JIS K 6253, such as chloroprene, is effective, but a type D durometer hardness according to JIS K 6253 is indicated by 35 or more and 50 or less. In the case of a material having a high material hardness such as a thermoplastic polyester elastomer, the effect can be exhibited more.

  Boots made of thermoplastic polyester elastomer have better fatigue resistance, wear resistance, low temperature resistance, heat aging resistance, grease resistance (oil resistance), etc. than boots made of chloroprene rubber. . For example, after the drive shaft with boots attached to a constant velocity universal joint is left to stand for a long time in an atmosphere of 100 ° C. and subjected to heat aging, the operation of the sliding type constant velocity universal joint in an atmosphere of 25 ° C. As a result of continuous operation at a rotation speed of 600 rpm while sliding while changing the angle between a low angle and a high angle, the boot made of thermoplastic polyester elastomer exhibits excellent durability.

  Further, under the same conditions, as shown in FIG. 2 of Patent Document 5, when a boot made of a thermoplastic polyester elastomer having a gap portion in the thick portion 12b of the large-diameter mounting portion 12 is tested, the tightening force of the band 13 However, it cannot be sufficiently transmitted to the boot mounting portion of the outer joint member 2 and grease leakage occurs.

  On the other hand, boots made of thermoplastic polyester elastomer have better impact resistance than chloroprene rubber boots, so they are resistant to damage during handling of drive shafts and stepping stones after mounting in automobiles. Also excellent.

  In addition to the mountability of the boot 10 to the outer joint member 2, the mountability of the bands 13, 15 to the boot 10 is an important factor to be considered in assembling the constant velocity universal joint. For example, both side walls of the band groove 18 may be continuously provided on the entire circumference, but in that case, the band mounting property may be lowered. Therefore, among the side walls of the band groove 18, in particular, the protrusion 19 that forms the side wall on the end face side that appears on the right side in FIG. 5 has no problem in the mountability of the band 13 and the position of the band 13 is stable. As the setting to be performed, the following configuration is preferable. That is, as can be seen from FIG. 6, the protrusions 19 are intermittently arranged in the circumferential direction, for example, at three equal positions, and the height of each protrusion 19 is 0.6 mm or more and 1.2 mm or less, and the axial dimension. Is 0.6 mm to 2.0 mm and the circumferential dimension is in the range of 10 ° to 25 ° from the boot axis.

  As shown in FIG. 6, the inner peripheral surface of the large-diameter mounting portion of the boot 10 has a shape along the outer peripheral surface shape of the mouth portion 22 of the outer joint member 2. That is, the thin part 12a corresponding to the large diameter part 22a of the mouse part 22 and the thick part 12b corresponding to the small diameter part 22b appear alternately.

  As shown in FIG. 7, the inner peripheral surface of the thin portion 12a of the large-diameter mounting portion 12 has a chamfered portion A from the end surface side, a straight portion B parallel to the axis, a recess C, and a shoulder pad D as shown in FIG. It is formed continuously.

  The chamfered portion A is provided at least 1 mm from the end surface at an angle of 20 ° to 60 ° with respect to the axis. By providing such a chamfered portion A, the above-described boot mounting property can be further improved. The end surface side diameter of the chamfered portion A is set larger than the minimum diameter of the end surface side inclined surface 36 of the protruding portion 32 of the outer joint member 2. The meeting part of the end surface side slope 36 and the end surface 38 of the protrusion 32 of the outer joint member 2 is rounded and smoothly connected. Thus, when the boot 10 is mounted, the chamfered portion A of the boot 10 is guided by the rounded portion, so that the boot 10 can be mounted more smoothly.

The recess C has slopes C ₁ and C ₂ that contact the slopes 34 and 36 of the protrusion 32 in order to receive the protrusion 32 of the outer joint member 2. Assuming that these are the third slope C ₁ and the fourth slope C ₂ , the third slope C ₁ corresponds to the first slope 34 of the protrusion 32, and the fourth slope C 2 is the second slope of the protrusion 32. Corresponds to the slope 36. Since it is such a structure, the hollow C fits with the protrusion part 32 of the outer joint member 2, and generates the removal | prevention action to an axial direction.

  The large-diameter attachment portion 12 of the boot 10 is required to be easily attached to the boot attachment portion of the outer joint member 2 and exhibit a sufficient sealing property when tightened with the band 13. Therefore, the recess C provided on the inner surface of the large-diameter mounting portion 12 of the boot 10 has a shape along the protruding portion 32 of the outer joint member 2.

  The contour of the portion of the boot 10 from the recess C to the shoulder pad D substantially matches the contour of the portion of the outer joint member 2 from the protruding portion 32 to the end surface 38. The shoulder rest D abuts against the end face 38 of the outer joint member 2 and serves to stabilize the axial position of the boot 10.

  A shoulder 17 that connects the large-diameter mounting portion 12 and the bent portion 16 is formed thicker than the thickness of the bent portion 16 or the large-diameter mounting portion 12. Here, the shoulder portion 17 refers to a portion from the end surface 18 a on the bent portion 16 side of the band groove 18 provided in the large-diameter mounting portion 12 of the boot 10 to the inclined surface 17 a connected to the final valley 16 a of the bent portion 16. It is preferable that the thinnest wall thickness of the shoulder portion 17 is not less than twice the wall thickness of the hollow C portion which is the thinnest wall portion in the large-diameter mounting portion 12. Such a configuration is more effective in a boot having a thin boot thickness, specifically, a bellows thickness of about 0.5 mm to 2.0 mm.

  The inclined surface 17a may be an inclined surface that decreases in diameter toward the final valley 16a as illustrated in FIG. 7, and may have a cylindrical shape as illustrated in FIG. Alternatively, as shown in FIG. 10, it may be a shape that once expands in the outer diameter direction and then decreases in diameter. Further, as illustrated in FIG. 7, the shoulder portion 17 may be designed to come into contact with the protruding portion 32 or the end surface 38 in the boot mounting portion of the outer joint member 2 or may be designed to provide a space.

  As shown in FIG. 8, the inner peripheral surface of the thick portion 12 b of the large-diameter mounting portion 12 of the boot 10 is continuously formed with a chamfered portion A and a linear portion F parallel to the axis from the end surface side. . The chamfered portion A is the same as that of the thin portion already described. As is clear from a comparison between FIG. 7 and FIG. 8, the thick portion 12 b is inevitably thick even in the shoulder portion 17.

  Protrusions E that are continuous over the entire circumference are formed on the inner circumferential surface of the large-diameter mounting portion 12 of the boot 10. This protrusion E is located in the said linear part B and F in a thin part and a thick part. The cross-sectional shape of the protrusion E may be a semicircle or a semi-ellipse, but a triangle is more preferable. In the illustrated embodiment, the protrusion E has a triangular cross section, and the apex is directed radially inward of the boot, that is, toward the axial center. The protrusion E contacts the boot groove 30 of the outer joint member 2 and exhibits a sealing function. Two or more protrusions E may be provided. Alternatively, a discontinuous protrusion different from the protrusion E may be provided. By tightening with the band 13, the protrusion E uniformly adheres to the boot groove 30 of the non-cylindrical boot mounting portion of the outer joint member 2 on the circumference and exhibits a sufficient sealing property. The bottom surface of the boot groove 30 of the outer joint member 2 with which the protrusion E is in close contact is smooth. The bottom surface of the boot groove 30 may have various shapes such as providing a protrusion, but is preferably smooth from the viewpoint of the processing man-hour of the outer joint member 2.

  The protrusion E in the large-diameter mounting portion 12 of the boot 10 is smoothly connected by rounding in a concave arc shape at the boundary between the thin portion 12a and the thick portion 12b. As a result, as shown in FIG. 11, the boot is connected to the outer joint member more than other portions of the normal tightening margin at the joint portion of the two different curved surfaces at the circumferential end portion of the boot groove 30 of the outer joint member 2. It becomes possible to bite in and the sealing performance is improved. However, if the radius of curvature is too large, the central portion is “bearing” and a gap is generated, resulting in a decrease in sealing performance. Therefore, the radius of curvature of the roundness is preferably 0.5 mm or more and 5 mm or less.

  The area of the recess C and the protrusion E and the tightening margin of the outer joint member 2 with respect to the boot mounting portion is such that the protrusion E part overcomes the protrusion 32 of the outer joint member 2 due to elastic deformation, and the protrusion E and the outer joint member 2 The setting which can maintain sufficient sealing performance between the boot grooves 30 is required.

  This boot setting is important when the material of the boot is high, such as when the material is high, such as when the material of the boot is a thermoplastic elastomer, especially a thermoplastic polyester elastomer with a type D durometer hardness of 35 to 50 in accordance with JIS K 6253. is there. The step between the boot groove 30 and the protrusion 32 of the outer joint member 2 is 0.8 mm or more and 1.5 mm or less, and the margin for the protrusion 32 of the recess C of the large-diameter mounting portion 12 of the boot 10 attached thereto is secured. It is preferable that the radius is 0.1 mm or more and 1.0 mm or less, and the interference with the boot groove 30 at the tip of the protrusion E is 0.1 mm or more and 1.5 mm or less. Furthermore, the height of the protrusion E is preferably 0.3 mm or greater and 1.0 mm or less.

  With the tightening setting as described above, the large-diameter mounting portion 12 of the boot 10 can be attached to the protrusion E beyond the protruding portion 32 of the outer joint member 2, and then tightened with the band 13, The large-diameter attachment portion 12 of the boot 10 can be attached in close contact with the boot attachment portion of the outer joint member 2. If it is set to be smaller than the above-mentioned tightening margin, there is a possibility that a gap is locally generated by the deformation of the boot 10 when the band 13 is tightened. On the other hand, if the setting is larger than the above-described tightening margin, it is difficult to attach the boot. Moreover, when the height of the protrusion E is less than 0.3 mm, the adhesion of the outer joint member 2 to the groove 30 is lowered, and sufficient sealing performance cannot be obtained. When the height of the protrusion E exceeds 1.0 mm, the volume of the protrusion becomes too large, which is not efficient in terms of design and sealing properties.

  The recess C and the protrusion E of the boot 10 are preferably positioned within the range of the width of the band groove 18. With such a configuration, the band tightening force is transmitted to the protrusion E in the vertical direction, and the restraint in the axial direction of the recess C fitted to the protrusion 32 is strengthened. Sex is obtained.

  The intermediate shaft that transmits power by connecting the fixed constant velocity universal joint and the sliding constant velocity universal joint of the drive shaft that satisfies the above requirements may have a hollow portion in the shaft center. By applying this hollow shaft, the drive shaft can be reduced in weight and the resonance point can be adjusted. Further, the hollow shaft may have a connecting element integrally formed at the end of a pipe formed of steel, or may be formed by plastic working from a steel tube and integrally include a connecting element at the end. There may be.

  In the above description, the tripod type constant velocity universal joint is taken as an example of the sliding type constant velocity universal joint. However, the present invention applies to all the sliding type constant velocity universal joints in which the boot mounting portion of the outer joint member has a non-cylindrical shape. Can be applied to. For example, as shown in FIGS. 12 to 14, the present invention can be applied to a tripod type in which the boot attachment portion of the outer joint member is not cylindrical. Further, the present invention can also be applied to a constant velocity universal joint using a ball as a torque transmitting element other than the tripod type, such as a double offset type (see FIGS. 15 to 17).

It is a longitudinal cross-sectional view of a drive shaft. It is a longitudinal cross-sectional view of a sliding type constant velocity universal joint. It is a cross-sectional view of the sliding type constant velocity universal joint of FIG. It is a principal part enlarged view of the outer joint member in FIG. It is a longitudinal cross-sectional view of boots. FIG. 6 is a right side view of the boot of FIG. 5. It is an enlarged view of the thin part of the boot of FIG. It is an enlarged view of the thick part of the boot of FIG. It is principal part sectional drawing of the boot which shows a modification, Comprising: (A) respond | corresponds to FIG. 7, (B) respond | corresponds to FIG. It is principal part sectional drawing of the boot which shows another modification, Comprising: (A) respond | corresponds to FIG. 7, (B) respond | corresponds to FIG. It is detail drawing of the contact part of an outer joint member and a boot, Comprising: (A) shows both separately and (B) shows the state which fitted the boot to the outer joint member. It is a perspective view of the outer joint member which shows another embodiment. It is a cross-sectional view of the outer joint member of FIG. FIG. 14 is an X-O-Y cross-sectional view of the outer joint member of FIG. 13. It is a perspective view of the outer joint member which shows another embodiment. It is a cross-sectional view of the outer joint member of FIG. It is a longitudinal cross-sectional view of the outer joint member of FIG.

Explanation of symbols

J ₁ sliding type (tripod type) constant velocity universal joint 2 outer joint member 22 mouse part 22a large diameter part 22b small diameter part 24 track groove 30 boot groove 32 projecting part 38 end face 26 stem part 28 spline or serration shaft 4 tripod member 42 Boss 44 Spline or serration hole 46 Leg shaft 6 Roller 8 Needle roller 10 Boot 12 Large diameter mounting portion 12a Thin wall portion 12b Thick wall portion 14 Small diameter mounting portion 16 Bellows portion (bending portion)
J ₂ fixed type (Rzeppa type) constant velocity universal joint 10 'boot S intermediate shaft

Claims (6)

  It consists of a fixed constant velocity universal joint fitted with a thermoplastic elastomer boot, a sliding constant velocity universal joint fitted with a thermoplastic elastomer boot, and an intermediate shaft connecting the two joints. The large-diameter attachment part attached to the outer joint member of the boot attached to the universal joint is a non-cylindrical shape in which a thin part and a thick part appear alternately in the circumferential direction, a cylindrical outer peripheral surface, and an outer joint member A drive shaft having a non-cylindrical inner peripheral surface along a boot mounting portion, wherein the entire volume of the large-diameter mounting portion is filled with a boot material.   The drive shaft according to claim 1, wherein the intermediate shaft has a hollow portion in an axial center.   3. The drive shaft according to claim 2, wherein the intermediate shaft is integrally provided with a connecting element at an end portion of a pipe formed of a steel material.   3. The drive shaft according to claim 2, wherein the intermediate shaft is integrally provided with a connecting element at an end portion of a pipe formed by plastic working from a steel base tube. 5. The drive shaft according to claim 1, wherein the sliding type constant velocity universal joint is a tripod type. The drive shaft according to any one of claims 1 to 5, wherein the boot is made of a thermoplastic polyester elastomer having a type D durometer hardness of 35 to 50 according to JIS K 6253.

Images