阅读说明：本技术 传动轴 (Transmission shaft ) 是由 梅泽祥 于 2018-12-12 设计创作，主要内容包括：传动轴具有：外圈(10),其形成有沿轴向贯通的多个螺栓孔(13)；动力传递部件,其以自如摆动的方式被配置在外圈(10)内；轴部件(30),其前端部形成有大径部(31)且后端部与动力传递部件连接；橡胶制成的密封部件(40),其用于密封外圈(30)的前侧开口；和圆盘状的保护部件(108),其被安装在轴部件(30)的大径部(31)和后端部之间,在保护部件(108)上形成有相对于螺栓紧固工具(91)的避让部(84),避让部(84)形成为以轴心(O1)为中心的环状。(The transmission shaft has: an outer ring (10) having a plurality of bolt holes (13) formed therethrough in the axial direction; a power transmission member disposed in the outer ring (10) so as to be swingable; a shaft member (30) having a large diameter section (31) formed at the front end thereof and a rear end connected to the power transmission member; a sealing member (40) made of rubber for sealing a front-side opening of the outer ring (30); and a disk-shaped protection member (108) that is attached between the large diameter portion (31) and the rear end portion of the shaft member (30), wherein a relief portion (84) for the bolt fastening tool (91) is formed in the protection member (108), and the relief portion (84) is formed in a ring shape centered on the axial center (O1).)

1. A transmission shaft is characterized in that a shaft body is provided with a transmission shaft body,

has an outer race, a power transmission member, a shaft member, a sealing member made of rubber, and a disk-shaped protective member,

the outer ring is provided with a plurality of bolt holes which are communicated along the axial direction;

the power transmission member is disposed in the outer ring so as to be swingable;

a large diameter part is formed at the front end part of the shaft part, and the rear end part of the shaft part is connected with the power transmission part;

the sealing component is used for sealing the front opening of the outer ring;

the protection member is mounted between the large diameter portion and the rear end portion of the shaft member,

the protection member is formed with a relief portion for a bolt fastening tool,

the escape portion is formed in a ring shape with an axis as a center.

2. A transmission shaft is characterized in that a shaft body is provided with a transmission shaft body,

comprises an outer ring, a power transmission member, a shaft member, a sealing member made of rubber, and a disk-shaped protective member,

the outer ring is provided with a plurality of bolt holes which are communicated along the axial direction;

the power transmission member is disposed in the outer ring so as to be swingable;

a large diameter part is formed at the front end part of the shaft part, and the rear end part of the shaft part is connected with the power transmission part;

the sealing component is used for sealing the front opening of the outer ring;

the protection member is mounted between the large diameter portion and the rear end portion of the shaft member,

the protection member is provided with a relief portion which is arranged in phase with the bolt hole when viewed in the axial direction and faces the bolt fastening tool.

3. The propeller shaft of claim 1 or 2,

the protection member is provided with a blocking portion that extends forward from an edge portion of the escape portion and blocks a front side of the escape portion.

4. The propeller shaft of claim 1 or 2,

an edge of the escape portion of the protective member is cut off.

5. The propeller shaft of claim 1 or 2,

the protective member is fitted to the shaft member.

6. The propeller shaft of claim 1 or 2,

the protective member is inserted through the shaft member, and is prevented from coming off by a ring member attached to the shaft member.

7. The propeller shaft of claim 1 or 2,

the protective member is inserted through the shaft member and fastened by a fastening band.

8. The propeller shaft of claim 7,

the fastening tape also fastens the end of the sealing member.

9. The propeller shaft of claim 1 or 2,

has a cylindrical member having a rear end portion fixed to the outer ring and a front end portion supporting the seal member,

the bolt hole is formed in the main body portion of the outer ring,

at least a part of the escape portion is located radially inward of the outer peripheral surface of the cylindrical member.

10. The propeller shaft of claim 1 or 2,

the bolt holes are formed in the flange of the outer ring,

at least a part of the escape portion is located radially inward of an outer peripheral surface of the main body portion of the outer ring.

Technical Field

The invention relates to a transmission shaft.

Background

The propeller shaft is a power transmission shaft extending in the front-rear direction of the vehicle, and transmits power generated by the prime mover and reduced to a predetermined speed by the transmission to the final reduction gear. The propeller shaft is provided with universal joints at both ends thereof for connection to a transmission and a final reduction gear. A cross-type joint is generally used as the universal joint, but a constant velocity universal joint is sometimes used as the universal joint in order to suppress generation of vibration of the power transmission system.

A constant velocity joint having an outer race, an inner race disposed within the outer race, a power transmission member (e.g., a plurality of balls), and a shaft member; the power transmission member is interposed between the inner race and the outer race and transmits power (torque); one end of the shaft member is spline-fitted to the inner ring and the other end is joined to the pipe.

Further, the opening of the outer ring is sealed with a boot (boots) in order to prevent the grease sealed in the outer ring from flowing out and to prevent dust from entering the outer ring. The boot is generally composed of a metal boot hub (cylindrical member) fitted to the outer portion of the outer ring and a projecting tongue (seal member) made of rubber, and one end of the projecting tongue is fixed to the boot hub and the other end is fixed to the shaft member (see patent document 1).

Further, the projecting tongue portion has a recessed portion recessed in one of the front-rear directions, and when the recessed portion is directed forward, stones or snow splashed by the front wheel may enter the recessed portion, thereby causing damage to the projecting tongue portion. Therefore, patent document 2 proposes to dispose a disk-shaped protective member in front of the tab portion.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-300254

Patent document 2: japanese Utility model patent laid-open publication No. Sho 61-59923

Disclosure of Invention

[ problem to be solved by the invention ]

However, in order to connect to the input shaft of the final reduction gear, a plurality of bolt holes penetrating in the axial direction are formed in the outer ring in the circumferential direction. Therefore, if a bolt inserted through the bolt hole is fastened by a bolt fastening tool, the bolt fastening tool may interfere with the protective member.

In contrast, if the protective member is disposed away from the outer ring in order to prevent interference between the bolt tightening tool and the protective member, small stones or the like easily enter the recessed portion of the tongue projecting portion. If the size of the protective member is increased to prevent this, the layout of the vehicle is adversely affected, which is not preferable.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a propeller shaft having a protective member and capable of ensuring workability of attachment to a vehicle.

[ solution for solving problems ]

In order to solve the above-mentioned problems, a propeller shaft according to claim 1 is characterized in that: the power transmission device comprises an outer ring, a power transmission part, a shaft part, a sealing part made of rubber and a disc-shaped protection part, wherein a plurality of bolt holes penetrating along the axial direction are formed in the outer ring; the power transmission member is disposed in the outer ring so as to be swingable; a large diameter part is formed at the front end part of the shaft part, and the rear end part of the shaft part is connected with the power transmission part; the sealing component is used for sealing the front opening of the outer ring; the protection member is attached between the large diameter portion and the rear end portion of the shaft member, and the protection member is formed with a relief portion for a bolt fastening tool, the relief portion being formed in a ring shape with an axis as a center.

In order to solve the above-mentioned problems, a propeller shaft according to claim 2 is characterized in that: the power transmission device comprises an outer ring, a power transmission part, a shaft part, a sealing part made of rubber and a disc-shaped protection part, wherein a plurality of bolt holes penetrating along the axial direction are formed in the outer ring; the power transmission member is disposed in the outer ring so as to be swingable; a large diameter part is formed at the front end part of the shaft part, and the rear end part of the shaft part is connected with the power transmission part; the sealing component is used for sealing the front opening of the outer ring; the protection member is attached between the large diameter portion and the rear end portion of the shaft member, and a relief portion that is arranged in phase with the bolt hole when viewed in the axial direction and faces the bolt fastening tool is formed in the protection member.

According to the above-described means 1 and 2, when fastening a bolt, the bolt fastening tool is disposed in the escape portion of the protective member, and the tool does not interfere with the protective member. Therefore, the workability of mounting to the vehicle can be ensured.

In addition, in claim 2, it is preferable that: the protection member is provided with a blocking portion that extends forward from an edge portion of the escape portion and blocks a front side of the escape portion. According to the above configuration, small stones or the like flying from the front toward the escape portion come into contact with the blocking portion and do not enter the concave portion of the sealing member.

In the above-described claim 2, an edge portion of the escape portion in the protective member may be cut off. According to the structure, the shape of the protection member becomes simple to reduce the manufacturing cost.

In the above-described aspects 1 and 2, the protective member may be fitted to the shaft member. Alternatively, the following may be used: the protective member is inserted through the shaft member, and is prevented from coming off by a ring member attached to the shaft member. Alternatively, the following may be used: the protective member is inserted through the shaft member and fastened by a fastening band.

In addition, it is preferable that: the fastening tape also fastens the end of the sealing member. According to the above configuration, the number of parts of the fastening tape for fastening the sealing member can be reduced.

In addition, in the above-described claim 1 and claim 2, the following may be adopted: the transmission shaft has a cylindrical member having a rear end portion fixed to the outer ring and a front end portion supporting the seal member, the bolt hole is formed in a main body portion of the outer ring, and at least a part of the escape portion is located radially inward of an outer peripheral surface of the cylindrical member. Alternatively, the following may be used: the bolt hole is formed in a flange (flange) of the outer ring, and at least a part of the escape portion is located radially inward of an outer peripheral surface of the main body portion of the outer ring.

[ Effect of the invention ]

According to the propeller shaft of the present invention, it is possible to secure the workability of mounting to a vehicle while having a protective member.

Drawings

Fig. 1 is a plan view of a propeller shaft according to a first embodiment as viewed from above.

Fig. 2 is an enlarged view of the rear universal joint of the first embodiment.

Fig. 3 is a sectional view taken along line III-III of fig. 2.

Fig. 4 is an enlarged view of the rear universal joint of the second embodiment.

Fig. 5 is a sectional view taken along line V-V of fig. 4.

Fig. 6 is a perspective view of a protective member of the third embodiment.

Fig. 7 is an enlarged view of the rear universal joint of the fourth embodiment.

Fig. 8 is an enlarged view of the rear universal joint of the fifth embodiment.

Detailed Description

Next, the propeller shafts 1, 101, 201, 301, and 401 according to the embodiments will be described with reference to the drawings. The same technical elements in the respective embodiments are denoted by the same reference numerals, and descriptions thereof are omitted.

(first embodiment)

The propeller shaft 1 is mounted on a four-wheel drive vehicle of an FF (front-engine front-drive) drive system, for example. The propeller shaft 1 is disposed below a floor panel (not shown), extends in the front-rear direction of the vehicle, and transmits power from a transmission (not shown) at the front of the vehicle body to a final reduction gear (not shown) at the rear of the vehicle body.

As shown in fig. 1, the propeller shaft 1 has: a first pipe 2 and a second pipe 3 which are cylindrical steel pipes and are divided in the front-rear direction; a middle universal joint 4 connecting the first pipe 2 and the second pipe 3; a front universal joint 6 disposed on the front side of the first pipe 2; a rear universal joint 7 disposed on the rear side of the second pipe 3; and a protective member 8 disposed behind the second pipe 3.

In the propeller shaft 1, a stub shaft (stub shaft)4c of the intermediate universal joint 4, which will be described later, is rotatably supported by a bearing structure 5 attached to a base plate (not shown).

As the intermediate universal joint 4, a tripod (tripod) type constant velocity universal joint is used. The tripod constant velocity joint has a cylindrical outer race 4a, a power transmission member 4b, and a stub shaft 4c as a solid shaft member, wherein the outer race 4a is engaged with a front end of the second tube 3; the power transmission member 4b swings inside the outer race 4 a; the stub shaft 4c is connected to the power transmission member 4 b.

The intermediate universal joint 4 of the present invention is not limited to a constant velocity universal joint, and a cross-type joint may be used. In the case of using a constant velocity joint in the present invention, the constant velocity joint is not limited to a tripod type constant velocity joint, and may be a constant velocity joint of a ball cage (birfield) type or a double offset (double offset) type, without being particularly limited.

The same constant velocity joints are used as the front side universal joint 6 and the rear side universal joint 7. Therefore, the rear universal joint 7 will be described as a representative example, and the description of the front universal joint 6 will be omitted.

As shown in fig. 2, a birfield constant velocity joint is used as the rear universal joint 7. The birfield constant velocity joint includes an outer race 10, an inner race 20, a plurality of balls (balls) (not shown), a stub shaft 30 as a shaft member, a tongue portion 40, and a boot bush 50.

The outer ring 10 is a forged component having a cylindrical body 11 opened in the front and rear and an annular flange 12, and the flange 12 extends radially outward from an outer peripheral surface 11a of the body 11.

The inner peripheral surface of the body 11 is formed in a spherical shape. A plurality of outer grooves (not shown) extending in the front-rear direction and having an arc shape in cross-section are formed in the circumferential direction on the inner circumferential surface of the body 11.

The flange 12 is a portion for connecting to a counterpart flange (counterpart flange)60 (see the broken line in fig. 2), the counterpart flange 60 being connected to an input shaft of a final reduction gear (not shown), and is located at a rear end of the outer peripheral surface 11a of the main body 11. The flange 12 is formed with 6 bolt holes 13 (only 1 is shown in fig. 2) that penetrate in the direction of the rotation axis O1 at equal intervals in the circumferential direction.

The inner ring 20 is cylindrical, and a hole spline 21 is formed on the inner peripheral surface of the inner ring 20. The outer peripheral surface of the inner ring 20 is formed in a spherical shape. A plurality of inner grooves (not shown) extending in the front-rear direction and having an arc shape in cross-section are formed in the circumferential direction on the outer circumferential surface of the inner ring 20. A cage (cage)23 is fitted into the outer peripheral surface of the inner ring 20. A window (not shown) is formed as an opening in the holder 23.

The balls are spheres made of metal. The balls are accommodated in the inner groove of the inner ring 20 and partially exposed from the window portion of the cage 23. Further, the portion of the balls exposed to the outside from the window portion enters the outer groove of the outer ring 10.

The cage 23 functions as follows: the balls 30 rolling between the inner grooves 22 of the inner ring 20 and the outer grooves 11b of the outer ring 10 are arranged on a bisector of an angle formed by the outer ring 10 serving as an input shaft and the inner ring 20 serving as an output shaft. By this action, the input shaft and the output shaft transmit power without generating rotational fluctuation.

The stub shaft 30 is a shaft member extending in the direction of the rotation axis O1, and the stub shaft 30 includes: a large diameter portion 31 disposed at the front; a small diameter portion 32 disposed at the rear; and an intermediate portion 33 interposed between the large diameter portion 31 and the small diameter portion 32.

The large diameter portion 31 is formed to have a circular outer shape and the same diameter as the second tube 3, and is formed to have a larger diameter than the small diameter portion 32 and the intermediate portion 33. Further, the tip of the large diameter portion 31 is joined to the second pipe 3 by welding.

A shaft spline 32a is formed on the outer peripheral surface of the small diameter portion 32, and the shaft spline 32a is spline-fitted to the hole spline 21 of the inner race 20.

At the rear of the intermediate portion 33 is mounted a front end 41 of a tab portion 40 secured by a strap 43.

A fitted portion 34 to which a later-described mounting portion 81 of the protective member 8 is fitted is formed in a front portion of the intermediate portion 33. Further, a stepped surface 35 extending radially outward is formed on the intermediate portion 33 on the front side of the fitted portion, so that the protective member 8 is regulated so as not to move forward.

The tongue portion 40 is a rubber-made component for closing the front-side opening of the outer ring 10, and has a substantially J-shape in cross-sectional view, and a recessed portion 44 that opens at the front.

The boot bush 50 is a metal component having a cylindrical shape, and the rear end 51 thereof is fitted into and pressed against the outer peripheral surface 11a of the outer ring 10. The front end 52 of the boot bush 50 is folded back inward to sandwich the rear end 42 of the tongue 40.

The protective member 8 is formed by processing a metal plate, and is a thin plate-like component.

The protective member 8 has a cylindrical mounting portion 81, a body portion 82, and a blocking portion 83, wherein the mounting portion 81 is fitted to the outside of the fitted portion 34; the main body 82 extends radially outward from the front end of the mounting portion 81; the stopper portion 83 is formed on the outer peripheral side of the body portion 82.

As shown in fig. 3, the body portion 82 has a circular plate shape centered on the rotation axis O1. The main body 82 has an outer diameter r1 and is formed smaller than the outer diameter r2 of the outer ring 10.

Therefore, the outer peripheral edge 82a of the main body 82 is positioned radially inward of the outer peripheral surface 11a of the outer ring 10, and an annular relief portion (space) 84 is formed on the outer peripheral side of the outer peripheral edge 82a of the main body 82.

The blocking portion 83 is a portion for blocking the front of the escape portion 84.

The blocking portion 83 has front and rear tubes 83a and a disk portion 83b, wherein the front and rear tubes 83a extend forward from the outer end of the body portion 82; the disk portion 83b extends radially outward from the front end of the front and rear tubes 83 a.

The front and rear cylinders 83a are formed to have a length in the front-rear direction to such an extent that the disk portion 83b does not interfere with a bolt tightening tool 91 described later.

Next, the operation of attaching the transmission shaft 1 will be described.

The flange 12 of the outer ring 10 and the flange 61 of the mating flange 60 are butted against each other, and bolts, not shown, are inserted from the front of the bolt holes 13 and screwed to nuts, not shown. In addition, the bolts are rotated to fasten the flange 12 and the flange 61 together.

After the bolts are inserted into the bolt holes 13 and fastened, the fastening torque of the bolts and nuts is set to a predetermined value.

Here, if the bolt fastening tool 91 is directly engaged with the head of the bolt, the engagement portion 92 of the bolt fastening tool 91 interferes with the outer peripheral surface 11a of the outer ring 10 and cannot be engaged therewith. Therefore, the rear end of the extension portion (extension)90 is fitted into the head of the bolt, and the bolt fastening tool 91 is engaged with the front end of the extension portion 90. Accordingly, a part of the engaging portion 92 of the bolt fastening tool 91 is disposed in the escape portion 84 of the protective member 8 (see fig. 2 and 3).

Next, a tool, not shown, is locked to the nut and held so as not to rotate, and the bolt tightening tool 91 is rotated around the center O2 of the bolt hole 13, and the tightening torque is set to a predetermined value. After the tightening torque of each bolt is set to a predetermined value, the mounting work is finished.

According to the first embodiment described above, the bolt fastening tool 91 does not interfere with the protective member 8 when fastening a bolt, and therefore the bolt fastening work can be easily performed. Further, since the protective member 8 includes the body 82 and the blocking portion 83, small stones or the like are less likely to enter the concave portion 44 of the tongue portion 40.

(second embodiment)

Next, the propeller shaft 101 of the second embodiment will be described.

As shown in fig. 4 and 5, the protective member 108 of the transmission shaft 101 has a cylindrical mounting portion 181, a body portion 182, and six projecting pieces 183, wherein the mounting portion 181 is fitted to the outside of the fitted portion 34; the main body 182 extends radially outward from the front end of the mounting portion 181; the projecting piece 183 projects further radially outward from the body portion 182.

As shown in fig. 5, the body portion 182 extends toward the outer peripheral side of the intermediate portion 33 of the stub shaft 30 and is positioned radially inward of the outer peripheral surface 11a of the body portion 11 of the outer ring 10 (see an auxiliary line L in fig. 5).

On the other hand, the projecting piece 183 projects radially outward beyond the outer peripheral surface 11a of the outer ring 10. The protruding pieces 183 are arranged apart from each other on the outer peripheral side of the body portion 182, and relief portions (spaces) 184 are formed between the protruding pieces 183.

The protruding piece 183 is arranged so as not to overlap the bolt hole 13 of the outer ring 10 when viewed from the axial direction, and the relief portion 184 overlaps the bolt hole 13 of the outer ring 10.

As shown in fig. 4, a bent portion 185 bent backward is formed at an outer circumferential end of the protruding piece 183, thereby improving the strength of the protruding piece 183.

According to the second embodiment described above, when fastening the bolt B using the extension portion 90, a part of the engagement portion 92 of the bolt fastening tool 91 is disposed in the escape portion 184 so as not to interfere with the protective member 108.

(third embodiment)

Next, a propeller shaft 201 according to a third embodiment will be described.

As shown in fig. 6, the protective member 208 of the transmission shaft 201 has a cylindrical mounting portion 181, a body portion 182, six projecting pieces 183, and a blocking portion 285, wherein the mounting portion 181 is fitted to the outside of the fitted portion 34; the main body 182 extends radially outward from the front end of the mounting portion 181; the projecting piece 183 projects further radially outward from the body portion 182; the blocking portion 285 blocks the front of the escape portion 184. Therefore, the protective member 208 is different from the protective member 108 of the second embodiment in that it has the blocking portion 285.

The blocking portion 285 has an extended portion 285a and a plate portion 285b, each of which is substantially U-shaped, and the extended portion 285a extends forward from the edge 184a of the escape portion 184; the plate portion 285b is continuous with the front end of the escape portion 284 and extends in the vertical direction and the horizontal direction.

As in the first and second embodiments, according to the third embodiment described above, the effect of facilitating the bolt fastening work can be obtained. Further, since the front of the escape portion 184 is closed by the closing portion 285, small stones or the like are less likely to enter the concave portion 44 of the tongue protruding portion 40 than the protective member 108 of the second embodiment.

(fourth embodiment)

Next, the propeller shaft 301 according to the fourth embodiment will be described.

As shown in fig. 7, the protective member 308 of the propeller shaft 301 has a mounting portion 81, a main body portion 82, a blocking portion 83, and an extending portion 385, wherein the mounting portion 81 is fitted to the outside of the fitted portion 34; the main body 82 extends radially outward from the front end of the mounting portion 81; the blocking portion 83 is formed on the outer peripheral side of the main body portion 82 and in front of the blocking escape portion 384; the extension 385 extends rearward from the rear end of the mounting portion 81. Therefore, the protective member 308 is different from the protective member 108 of the second embodiment in that it has an extension 385.

The extension 385 extends along the stub shaft 30 and is cylindrical. The rear end 385a of the extension 385 covers the outer peripheral side of the front end 41 of the tab portion 40, and is fastened together with the front end 41 of the tab portion 40 by the belt 43.

As in the above-described embodiments, according to the fourth embodiment, the bolt fastening operation can be facilitated. In addition, the fixing strength of the protective member 308 is improved. Further, as compared with the case where the belt 43 for fastening the protective member 308 and the tab portion 40 is separately prepared, the number of parts can be reduced, and the cost can be reduced.

(fifth embodiment)

Next, a propeller shaft 401 according to a fifth embodiment will be described.

As shown in fig. 8, the propeller shaft 401 includes a first pipe 2 and a second pipe 3, an intermediate universal joint 4, a front universal joint 6, a rear universal joint 407, and a protective member 408.

The rear universal joint 407 is a cross-groove type constant velocity universal joint, and includes an outer race 410, an inner race 420, a plurality of balls (not shown), a stub shaft 430, a tongue portion 440, and a boot bush 450. Note that the short shaft 430 and the tab portion 440 are the same in structure as the short shaft 30 and the tab portion 40 described in the first embodiment, and therefore description thereof is omitted.

The outer race 410 is formed of a cylindrical body 411 that opens in the front and rear directions. A plurality of bolt holes 413 penetrating the front end surface and the rear end surface are formed in the main body 411 in the circumferential direction.

A hole spline 421 is formed on the inner peripheral surface of the inner ring 420 and spline-fitted to the small diameter portion 432 of the stub shaft 430. A cage 423 is fitted into an outer peripheral surface of the inner ring 420.

The balls are accommodated in an inner groove (not shown) of the inner ring 420 and partially exposed from a window portion (not shown) of the cage 423. Further, the portions of the balls exposed to the outside from the windows enter outer grooves (not shown) of the outer race 410.

The cage 423 functions as follows: the balls rolling between the inner grooves of the inner race 420 and the outer grooves (not shown) of the outer race 410 are disposed on a bisector of an angle formed by the outer race 410 serving as an input shaft and the inner race 420 serving as an output shaft. By this action, the input shaft and the output shaft transmit power without generating rotational fluctuation.

The boot bush 450 has an outer fitting portion 451, a folded portion 452, a cylindrical portion 453, and a clamping portion 454, wherein the outer fitting portion 451 is fitted to the outside of the outer peripheral surface of the main body portion 411 of the outer race 410; the folded-back portion 452 is folded back radially inward from the front end of the external fitting portion 451; the cylindrical portion 453 extends forward from the inner end of the folded portion 452; the clamping portion 454 folds the front end of the cylindrical portion 453 radially inward to clamp the rear end 442 of the tab portion 440.

The protective member 408 has a cylindrical mounting portion 481, a main body portion 482, and a stopper portion 483, wherein the mounting portion 481 is fitted to the outside of the stub shaft 430; the main body portion 482 extends radially outward from the front end of the mounting portion 481; the blocking portion 483 is formed on the outer circumferential side of the body portion 484, and an annular escape portion (space) 484 is formed on the outer circumferential side of the outer circumferential edge 482a of the body portion 482.

The body portion 482 has a circular outer shape centered on the rotation axis O1, and the outer diameter of the body portion 482 is set smaller than the outer diameter of the cylindrical portion 453 on the boot bush 450 (see the auxiliary line M in fig. 8). Therefore, the body portion 482 is positioned radially inward of the outer peripheral surface 453a of the cylindrical portion 453 when viewed from the rotation axis O1 direction.

Since the clearance between the outer peripheral surface of the head and the cylindrical portion 453 is small, a bolt B inserted into the bolt hole 413 and fastening the body portion 411 is a bolt having a hexagonal hole B1 formed in the head. A washer (washer) W is interposed between the body 411 and the head of the bolt B.

According to the fifth embodiment described above, when the hexagonal shaft 90a formed at the distal end portion of the extension portion 90 is inserted into the hexagonal hole B1 of the bolt B and the engagement portion 92 of the bolt fastening tool 91 is engaged with the distal end of the extension portion 90, a part of the engagement portion 92 is disposed in the escape portion 484 and does not interfere with the protective member 408. Therefore, the fastening work of the bolt B becomes easy.

The embodiments have been described above, but the present invention is not limited to the examples described in the embodiments. For example, the protective member 8 is not limited to a steel plate material, and may be molded from hard rubber or the like.

Further, a ring abutting against the rear end face of the main body of the protective member may be fitted to the outside of the intermediate portion of the stub shaft 30. This restricts the rearward movement of the protective member, thereby improving the fixing strength of the protective member.

Further, as the front side universal joint and the rear side universal joint, a birfield type constant velocity universal joint and a cross-groove type constant velocity universal joint are exemplified, but a tripod type or a double offset type constant velocity universal joint may be used. In addition, when the tripod type or double offset type constant velocity universal joint is used, as described in the first embodiment, at least a part of the escape portion needs to be formed so as to be positioned radially inward of the outer peripheral surface of the main body portion of the outer ring.

[ description of reference numerals ]

1. 101, 201, 301, 401, a transmission shaft; 7. 407: a rear-side universal joint; 8. 108, 208, 308, 408: a protective member; 10. 410: an outer ring; 11. 411: a main body portion; 12: a flange; 13. 413: bolt holes; 30. 430: a short shaft (shaft member); 40. 440, a step of: a tongue projecting portion; 44: a concave portion; 50. 450: a protective cover bushing; 60: a mating flange; 81. 181, 481: an installation part; 82. 182, 482: a main body portion; 83. 285, 483: a blocking portion; 84. 184, 284, 384, 484: an avoidance part; 90: an extension; 91: a bolt fastening tool; 92: a fastening part; 183: a projecting piece; 385: an extension portion; 453: a cylindrical portion.