Propeller shaft

Abstract

To provide a propeller shaft equipped with a protective boot that can select both an air vent function and a waterproof function.SOLUTION: An annular groove recessed in a radial direction is formed on an inner peripheral surface of a protective boot where a boot fastening part comes into contact with a stub shaft, and an external communication groove communicating from the annular groove to an outside of the protective boot and an internal communication groove communicating from the annular groove to an inside of the protective boot are further formed on the inner peripheral surface, and when used as the protective boot with an air vent function, the stub shaft with a flat outer peripheral surface is fitted into the boot fastening part of the protective boot so that the internal communication groove, the annular groove, and an external communication passage are connected, and when used as the protective boot with a waterproof function, the stub shaft with an annular protrusion formed on an outer peripheral surface so as to match the annular groove is fitted into the boot fastening part of the protective boot so that the annular groove closes the annular protrusion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a propeller shaft for an automobile, and more particularly to a propeller shaft provided with a protective boot at a constant velocity joint portion. [Background technology]

[0002] In a propeller shaft attached to the underside of an automobile body, the rotation of the drive source is transmitted to a stub shaft via a universal joint (hereinafter referred to as a constant velocity joint). A rubber protective boot is used on the propeller shaft to protect the internal mechanism of the constant velocity joint.

[0003] The protective boot is composed of a boot fixing portion that is fixed to the outer periphery of the constant velocity joint and a boot fastening portion that extends from the boot fixing portion toward the stub shaft and is fastened to the outer periphery of the stub shaft by a boot band. In such a protective boot, the air inside the protective boot can expand due to heat generated by the rotation of the constant velocity joint.

[0004] For this reason, a communication hole is provided in the protective boot to connect the inside with the outside (atmosphere). A propeller shaft equipped with such a protective boot with an added air vent function is described in, for example, JP 2012-241882 A (Patent Document 1).

[0005] Patent Document 1 shows a sliding type constant velocity universal joint that forms a seal portion with which a boot adapter that is externally fitted and fixed to the open end of an outer joint member tightly fits, and an air vent structure that is provided on the opening side of the seal portion and that vents air from inside the sealing device when the boot adapter is pressed in. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-241882 Summary of the Invention [Problem to be solved by the invention]

[0007] Recently, in addition to the air vent function of protective boots, there has been an increasing demand for waterproofing functions to prevent water and other substances from entering the protective boots. To achieve this, protective boots with a sealed structure that seals the inside and outside of the protective boots are required. However, in this case, it is necessary to manufacture protective boots with a new waterproofing function in addition to the protective boots with the air vent function.

[0008] This leads to problems such as high production costs and complicated parts management. Therefore, there is a demand for protective boots that can be selected to have both an air vent function and a waterproof function. In other words, there is a demand for a protective boot that can be used for both purposes.

[0009] An object of the present invention is to provide a propeller shaft equipped with a protective boot that can selectively have both an air vent function and a waterproof function. [Means for solving the problem]

[0010] The present invention relates to a propeller shaft comprising a first rotating shaft, a constant velocity joint attached to the first rotating shaft, a stub shaft attached to the constant velocity joint, a second rotating shaft attached to the stub shaft, and a protective boot attached to cover the constant velocity joint and the stub shaft from the outside, wherein the protective boot comprises a boot fixing portion attached to the outer periphery of the constant velocity joint and a boot fastening portion attached to the outer periphery of the stub shaft, and an annular groove recessed radially outward is formed on the inner circumferential surface of the boot fastening portion attached to the stub shaft, and further comprises an external communication groove communicating from the annular groove to the outside of the protective boot and an external communication groove connecting the annular groove to the protective boot. and when the protective boot is used as a protective boot with an air vent function, a stub shaft having a flat outer peripheral surface is fitted onto the inner peripheral surface of the boot fastening part so that the inner communicating groove, the annular groove, and the outer communicating groove are communicated as a conduit; and when the protective boot is used as a protective boot with a waterproof function, a stub shaft having an annular protrusion formed on its outer peripheral surface in a shape that matches the annular groove is fitted onto the inner peripheral surface of the boot fastening part so that the annular protrusion fits into the annular groove, thereby blocking the conduit consisting of the inner communicating groove, the annular groove, and the outer communicating groove. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a propeller shaft equipped with a protective boot that can select both an air vent function and a waterproof function. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external view showing the appearance of a propeller shaft to which the present invention is applied. [Figure 2] 2 is an enlarged cross-sectional view of the protective boot shown in FIG. 1. FIG. [Figure 3A] 3 is an enlarged perspective view of the protective boot shown in FIG. 2, seen from the direction A on the tip side. [Figure 3B] 3 is an enlarged perspective view of the protective boot shown in FIG. 2, seen from the direction B on the tip side. [Figure 4] 3 is a cross-sectional view of a boot-side fitting region of the protective boot of FIG. 2 cut along a plane perpendicular to the axis. [Figure 5] This is a cross-sectional view showing the constant velocity joint and stub shaft joined together and covered with a protective boot (with air vent function). [Figure 6] 6 is an enlarged view of a shaft-side fitting region of the stub shaft shown in FIG. 5. FIG. [Figure 7] 6 is an enlarged cross-sectional view showing the cross section of the fitted portion of the boot-side fitting region and the shaft-side fitting region shown in FIG. 5. FIG. [Figure 8] This is a cross-sectional view showing the constant velocity joint and stub shaft joined together and covered with a protective boot (waterproof). [Figure 9] 9 is an enlarged view of a shaft-side fitting region of the stub shaft shown in FIG. 8. FIG. [Figure 10] 9 is an enlarged cross-sectional view showing the cross section of the fitting portion of the boot-side fitting region and the shaft-side fitting region shown in FIG. 8 . FIG. [Figure 11] 9 is an enlarged cross-sectional view showing a modified example of the fitted portion of the boot-side fitting region and the shaft-side fitting region shown in FIG. 8; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications and application examples within the technical concept of the present invention are also included within its scope.

[0014] Before describing the present invention, the configuration of a propeller shaft, which is the basis of the present invention, will be described with reference to FIG.

[0015] As shown in Figure 1, the propeller shaft to which the present invention is applied is used in automobiles that use four-wheel drive or front-engine, rear-drive drive systems, and is mainly composed of a drive shaft 1 connected to a transmission coupled to a drive source such as an internal combustion engine, a driven shaft 2 connected to a differential gear, a constant velocity joint 3 connecting the drive shaft 1 and driven shaft 2, and a support device 4 provided on the driven shaft 2 and fixed to a floor member of the automobile, for example, the lower part of a cross member.

[0016] The drive shaft 1 is composed of a steel drive tube (first rotating shaft) 5, a Cardan joint 6 fixed to the front end of the drive tube 5 in the axial direction by welding, and a constant velocity joint casing 7 fixed to the rear end of the drive tube 5 in the axial direction by welding. The constant velocity joint casing 7 houses the internal mechanism that makes up the constant velocity joint.

[0017] The driven shaft 2 is mainly composed of a steel pipe driven tube (second rotating shaft) 8, a stub shaft 9 fixed axially to the front end of the driven tube 8 by welding, and a Cardan joint 10 fixed axially to the rear end of the driven tube 8 by welding.

[0018] It should be noted that the constant velocity joint 3 may be provided on the driven tube 8 and the stub shaft 9 may be provided on the driving tube 5, and the present invention is still applicable to such a configuration.

[0019] The interior of the constant velocity joint 3 is filled with lubricating oil such as grease, and a rubber protective boot 11 is attached to the front end of the constant velocity joint casing 7 to protect the internal mechanism of the constant velocity joint casing 7. As will be described below, this protective boot 11 is a multi-purpose protective boot 11 that can be configured to have both an air vent function and a waterproof function.

[0020] 2, the protective boot 11 is made of rubber and formed into a cylindrical shape with a step, and is composed of a boot fixing part 12 fitted onto the outer periphery of the tip end of the constant velocity joint casing 7, a boot intermediate part 13 formed by bending the tip end 12A of the boot fixing part 12 inward in a generally folded-back shape and extending further away from the boot fixing part 12 in the axial direction, and a boot fastening part 14 extending away from the boot intermediate part 13 in the axial direction and fitted onto the outer periphery of the shaft-side fitting region (not shown) of the stub shaft 9. In addition, a metal core 15 is embedded inside from the boot fixing part 12 to the boot intermediate part 13.

[0021] The tip end side of the shaft-side fitting region of the stub shaft 9 extends toward the constant velocity joint 3 and is connected to the inner ring of the constant velocity joint 3. This type of configuration is well known.

[0022] The boot fixing part 12 is fixedly attached to the constant velocity joint casing 7 (see FIG. 1) in a form that covers the tip side of the constant velocity joint casing 7 (see FIG. 1) in the axial direction. A fixing band attachment part 16 is formed in the boot fixing part 12, on which a fixing band (not shown) is arranged. This fixing band attachment part 16 has wall parts 16A that extend radially on both ends, and the fixing band is arranged in a recess sandwiched between the wall parts 16A, so that the boot fixing part 12 is pressed inward.

[0023] The boot intermediate part 13 has the function of connecting the boot fixing part 12 and the boot fastening part 14, and the boot fixing part 12, the boot intermediate part 13, and the boot fastening part 14 are integrally formed from a material such as rubber. The boot intermediate part 13 has an axial cross section formed in a substantially U-shape, and is shaped to be displaceable along the axial direction.

[0024] The diameter (D1) of the inner periphery of the boot fastening portion 14 of the protective boot 11 is set to be shorter than the diameter (D2) of the inner periphery of the boot middle portion 13. Therefore, the inner periphery of the boot fastening portion 14 is shaped to protrude inward from the inner periphery of the boot middle portion 13, forming a boot-side fitting region 17. Similarly, the diameter (D3) of the boot fastening portion 14 of the protective boot 11 on the boot tip portion 18 side is set to be longer than the diameter of the portion of the boot-side fitting region 17 that protrudes inward.

[0025] In this way, the area between the boot middle portion 11 and the boot tip portion 18 of the boot fastening portion 14 is defined as a boot-side fitting area 17 that protrudes inward. As will be described later, this boot-side fitting area 17 is an area into which a stub fitting area of ​​the stub shaft 9 is fitted. Here, fitting refers to a state in which the boot-side fitting area is press-fitted into the stub fitting area by a method such as press-fitting.

[0026] An annular groove 20 is formed in the circular inner peripheral surface 19 of the boot-side fitting region 17 of the protective boot 11. This annular groove 20 is a groove that recedes radially outward from the inner peripheral surface 19. Here, the annular groove 20 is formed so as to follow an imaginary plane that is perpendicular to the axis (C) of the protective boot 11, but is not limited to this and may be formed so as to obliquely intersect the axis (C).

[0027] An internal communication groove 21 connected to the annular groove 20 is formed on the inner circumferential surface 19 of the boot-side fitting region 17 of the protective boot 11. The internal communication groove 21 is a linear groove that extends in the direction along the axis (C) toward the boot intermediate portion 13 and recedes radially outward from the inner circumferential surface 19. In this embodiment, two internal communication grooves 21 are formed.

[0028] Furthermore, an external communication groove 22 connected to the annular groove 20 is formed on the inner peripheral surface 19 of the boot-side fitting region 17 of the protective boot 11. The external communication groove 22 is a linear groove that extends along the axis (C) toward the boot tip portion 18 of the boot fastening portion 14 and recedes radially outward from the inner peripheral surface 19. In this embodiment, one external communication groove 22 is formed.

[0029] The internal communication groove 21 and the external communication groove 22 are connected to the side surface of the annular groove 20, and this configuration connects the internal communication groove 21, the annular groove 20, and the external communication groove 22 to form an air conduction channel through which air can flow. Note that the internal communication groove 21 and the external communication groove 22 do not have to be grooves exposed on the inner circumferential surface 19, but may also be channels formed inside the boot-side fitting region 17.

[0030] Furthermore, a boot band mounting portion 23 on which a boot band (not shown) is placed is formed on the outer periphery of the boot-side mounting region 17. This boot band mounting portion 23 has wall portions 23A extending outward in the radial direction at both ends, and the boot band is placed in a recess formed by the walls 23A, thereby pressing the boot-side mounting region 17 inward. This wall portion 23A serves to prevent the corners (edges) of the boot band from digging into the boot fastening portion 14 and being cut after the boot band is fastened.

[0031] Fig. 3A shows the shape of the external communication groove 22 as viewed from the direction of arrow A in Fig. 2, and Fig. 3B shows the shape of the internal communication groove 21 as viewed from the direction of arrow B in Fig. 2. As can be seen from Figs. 3A and 3B, the cross-sectional area Ain through which air passes of the internal communication groove 21 (in this case, for one groove) is set to a value larger than the cross-sectional area Aout through which air passes of the external communication groove 22. The reason for this is to make it easier for air inside the protective boot 11 to be discharged to the outside through the internal communication groove 21 and to prevent moisture from entering the inside from the outside through the external communication groove 22.

[0032] 4 also shows the positions where the internal communication groove 21 and the external communication groove 22 are formed. The internal communication groove 21 and the external communication groove 22 extend along the axis (C) so as to be perpendicular (vertical to the plane of the drawing) to the annular groove 20, which is formed on a virtual radial plane perpendicular to the axis (C) of the protective boot 11. The external communication groove 22 is formed on the opposite side of the position where the internal communication groove 21 is formed, in this case at a position approximately 180° apart. By arranging the communication grooves 20 and 21 in point-symmetric positions in this way, it is possible to prevent biased pressure toward the inside of the boot-side fitting region 17 due to the grooves.

[0033] By using the protective boot 11 having such a configuration, it is possible to select both the air vent function and the waterproof function.

[0034] First, when the protective boot is used as a protective boot with an air vent function, a stub shaft with a flat outer circumferential surface can be fitted into the boot fastening portion of the protective boot so that the internal communication passage, the annular groove, and the external communication passage communicate with each other, thereby enabling the protective boot to be used as a protective boot with an air vent function.

[0035] Second, when the protective boot is used as a waterproof boot, a stub shaft having an annular protrusion formed on its outer circumferential surface in a shape that matches the annular groove can be fitted into the boot fastening portion of the protective boot, and the annular groove can be blocked by the annular protrusion, allowing the boot to be used as a waterproof boot.

[0036] The specific configurations of these will be described below with reference to the drawings.

[0037] <When used as protective boots with an air vent function> FIG. 5 shows a state in which the constant velocity joint 3 and the stub shaft 9 are combined and joined together using the common protective boot 11 shown in FIG.

[0038] As shown in Figures 1 and 5, the constant velocity joint 3 is mainly composed of a constant velocity joint casing 7, which is an outer race formed in a substantially cylindrical shape and is fixed to the rear end of the drive-side tube 5 of the drive shaft 1, an inner race 24 arranged on the inner peripheral side of the constant velocity joint casing 7, a plurality of torque transmission balls 25 provided so as to be able to roll between the constant velocity joint casing 7 and the inner race 24, and a cage (not shown) that holds the torque transmission balls 25.

[0039] Furthermore, a tip end 26 of the stub shaft 9 is press-fitted and fixed inside the inner race 24. Therefore, the rotation imparted to the constant velocity joint casing 7 from the drive-side tube 5 is transmitted to the stub shaft 9 and driven-side tube 8 via the constant velocity joint casing 7, torque transmission balls 25, and inner race 24.

[0040] The outer periphery of the tip end side of the constant velocity joint casing 7 is covered with the boot fixing portion 12 of the protective boot 11, and by tightening the fixing band 27 from the outer periphery side of this, it can be firmly fixed.

[0041] Additionally, the boot fastening portion 14 of the protective boot 11 is fitted onto the stub shaft 9 at a position midway along the stub shaft 9. In other words, the boot-side fitting region 17 formed on the boot fastening portion 14 is assembled into the shaft-side fitting region 28 of the stub shaft 9 by being pressed into place using a method such as press fitting.

[0042] Furthermore, a boot band 29 is fastened and fixed to the boot band mounting portion 23 (see Figure 2) formed on the outer periphery of the boot fastening portion 14 in the area where the boot side mounting area 17 is present, thereby pressing the boot side mounting area 17 toward the shaft side mounting area 28.

[0043] Next, the shape of the shaft-side fitting region 28 into which the boot-side fitting region 17 is press-fitted will be described below.

[0044] 6, the shaft-side fitting region 28, into which the boot-side fitting region 17 of the protective boot 11 is press-fitted, has an outer peripheral surface formed in a circular, flat shape. The diameter (D1-1) of this shaft-side fitting region 28 is formed slightly larger than the diameter (D1) of the inner peripheral surface of the boot-side fitting region 17 of the boot fastening part 14, thereby providing a so-called press-fitting allowance. Therefore, when the boot-side fitting region 17 is press-fitted into the shaft-side fitting region 28, an annular conduit is formed between the outer peripheral surface of the shaft-side fitting region 28 and the annular groove 20. This conduit serves as an air passage.

[0045] 7 is an enlarged view showing the shaft-side fitting region 28 of the stub shaft 9 press-fitted into the boot-side fitting region 17 of the protective boot 11. As can be seen from FIG. 7, the shaft-side fitting region 28 is formed over an area that includes the boot-side fitting region 17 when viewed in the axial (C) direction.

[0046] Therefore, the exposed side (inside) of the annular groove 20 is closed by the outer peripheral surface of the flat shaft-side fitting region 28. Therefore, the annular groove 20 acts as a conduit formed on the inner peripheral surface 19 of the boot-side fitting region 17.

[0047] Similarly, the internal communication groove 21 and the external communication groove 22 are also closed by the outer peripheral surface of the flat shaft-side fitting region 28. Therefore, the internal communication groove 21 and the external communication groove 22 also function as conduits formed on the inner peripheral surface 19 of the boot-side fitting region 17. The internal communication groove 21 is connected to the internal space of the boot middle part 13. The external communication groove 21 is also connected to the internal space of the boot tip part 18 of the boot fastening part 14. The internal space of the boot tip part 18 is connected to the outside.

[0048] Furthermore, since the internal communication groove 21 and the external communication groove 22 are connected to the annular groove 20, when the protective boot 1 is combined with the stub shaft 9, the internal communication groove 21, the annular groove 20, and the external communication groove 22 form a conduit for air conduction connecting the inside and outside of the protective boot 11.

[0049] Here, the axial width of the boot band 29 is set to a length that includes the annular groove 20. Therefore, the boot-side fitting area 17, where the annular groove 20 is formed, is pressed with a strong force against the shaft-side fitting area 28, preventing the boot fastening portion 14 of the protective boot 11 from moving.

[0050] That is, when the boot band 29 is fastened, a compressive force (Fr) is applied to the boot-side mounting area 17 by the boot band 29. This causes the boot-side mounting area 17 to adhere closely to the shaft-side mounting area 28, preventing the boot fastening portion 14 of the protective boot 11 from moving.

[0051] By adopting such a combination of protective boot 11 and stub shaft 9, the inside and outside of protective boot 11 can be fluidly connected, so that even if the air inside protective boot 11 expands due to heat generated by the rotation of the constant velocity joint, the expanded air can be easily discharged.

[0052] <When used as waterproof protective boots> FIG. 8 shows a state in which the constant velocity joint 3 and the stub shaft 9 are combined and joined together using the common protective boot 11 shown in FIG.

[0053] As shown in Figures 1 and 8, the constant velocity joint 3 is mainly composed of a constant velocity joint casing 7, which is an outer race formed in a substantially cylindrical shape and fixed to the rear end of the drive-side tube 5 of the drive shaft 1, an inner race 24 arranged on the inner peripheral side of the constant velocity joint casing 7, a plurality of torque transmission balls 25 provided so as to be able to roll between the constant velocity joint casing 7 and the inner race 24, and a cage (not shown) that holds the torque transmission balls 25.

[0054] Furthermore, a tip end 26 of the stub shaft 9 is press-fitted and fixed inside the inner race 24. Therefore, the rotation imparted to the constant velocity joint casing 7 from the drive-side tube 5 is transmitted to the stub shaft 9 and driven-side tube 8 via the constant velocity joint casing 7, torque transmission balls 25, and inner race 24.

[0055] The boot fixing portion 12 of the protective boot 11 is placed over the outer periphery of the tip end of the constant velocity joint casing 7, and is fixed with great force by tightening a fixing band 27 around this outer periphery. The boot fastening portion 14 of the protective boot 11 is fitted onto the stub shaft 9 midway along the stub shaft 9. In other words, the boot-side fitting region 17 formed on the boot fastening portion 14 is assembled into the fitting region 28 of the stub shaft 9 by a method such as press fitting so as to be in intimate contact with it.

[0056] Furthermore, a boot band 29 is fastened and fixed to the boot band mounting portion 23 (see Figure 2) formed on the outer periphery of the area where the boot side mounting area 17 is located, thereby pressing the boot side mounting area 17 toward the shaft side mounting area 28.

[0057] Next, the shape of the shaft-side fitting region 28 into which the boot-side fitting region 17 is press-fitted will be described below.

[0058] 9, the shaft-side fitting region 28, into which the boot-side fitting region 17 of the protective boot 11 is press-fitted, has an annular protrusion 30 formed therein that protrudes radially outward from the outer circumferential surface. Therefore, when the boot-side fitting region 17 is press-fitted into the shaft-side fitting region 28, the annular protrusion 30 of the shaft-side fitting region 28 fits into the groove portion of the annular groove 20, filling the annular groove 20. As a result, no air-conducting conduit is formed, and the connection between the interior communication groove 21 and the exterior communication groove 22 is cut off.

[0059] 10 is an enlarged view showing the stub shaft 9 press-fitted into the boot-side fitting region 17 of the protective boot 11. As can be seen from the figure, the shaft-side fitting region 28 is formed over an area that includes the boot-side fitting region 17 when viewed in the axial direction. Therefore, the exposed side of the annular groove 20 is filled with an annular protrusion 30 formed in the shaft-side fitting region 28.

[0060] Furthermore, even if the internal communication groove 21 and the external communication groove 22 are connected to the annular groove 20, when the protective boot 1 is combined with the stub shaft 9, the annular groove 20 disappears due to the annular protrusion 30, and therefore, no air conduction conduit is formed connecting the inside and outside of the protective boot 11.

[0061] Here, the axial width of the boot band 29 is set to a length that includes the annular groove 20. Therefore, the boot-side fitting area 17, where the annular groove 20 is formed, is pressed with a strong force against the shaft-side fitting area 28, so that the annular groove 20 and the annular protrusion 30 are tightly attached to each other, improving the waterproof function.

[0062] By adopting such a combination of protective boot 11 and stub shaft 9, the fluid connection between the inside and outside of the protective boot 11 can be blocked, thereby reducing the risk of moisture or the like penetrating into the inside of the protective boot 11.

[0063] Next, a modification of the embodiment shown in Fig. 10 will be described with reference to Fig. 11. This modification aims to further improve waterproofing.

[0064] 11, the end face of the boot-side mounting area 17 on the boot tip end 18 side is in contact with an abutment wall 31 formed adjacent to the shaft-side mounting area 28. In other words, a circular abutment wall 31 having an outer diameter larger than the outer diameter of the shaft-side mounting area 28 is formed adjacent to the end of the shaft-side mounting area 28 on the opposite side from the constant velocity joint 3, facing the side end face of the boot-side mounting area 17 on the boot tip end 18 side.

[0065] When the boot band 29 is tightened, a compressive force (Fr) is applied to the boot-side mounting area 17 by the boot band 29. This compressive force (Fr) causes the right end (boot tip 18 side) of the boot-side mounting area 17 to deform along the axial direction, so that the side end face of the boot-side mounting area 17 on the boot tip 18 side comes into contact with abutment wall 31 formed adjacent to the shaft-side mounting area 28 with great force, as indicated by the arrow (Prs). Therefore, this portion provides a new waterproof function.

[0066] Here, the diameter of the abutment wall portion 31 is set to a length that exceeds the bottom surface (outer diameter side of the groove) of the external communication groove 22. This allows the abutment wall portion 31 to reliably block communication with the external communication groove 22. The abutment wall portion 31 also has an enlarged diameter portion 32 that extends in the axial direction away from the constant velocity joint 3, and is positioned so that the tip end 18 of the boot fastening portion 14 comes into contact with this enlarged diameter portion 32.

[0067] As described above, the present invention provides a propeller shaft comprising a first rotating shaft, a constant velocity joint attached to the first rotating shaft, a stub shaft attached to the constant velocity joint, a second rotating shaft attached to the stub shaft, and a protective boot attached to cover the constant velocity joint and the stub shaft from the outside, wherein the protective boot comprises a boot fixing portion attached to the outer periphery of the constant velocity joint and a boot fastening portion attached to the outer periphery of the stub shaft, and the inner circumferential surface of the boot fastening portion attached to the stub shaft is formed with an annular groove that recedes radially outward, and further formed with an external communicating groove that communicates from the annular groove to the outside of the protective boot, and an internal communicating groove that communicates from the annular groove to the inside of the protective boot.

[0068] When the protective boot is used as a protective boot with an air vent function, a stub shaft having a flat outer surface is fitted onto the inner surface of the boot fastening portion, so that the internal communicating groove, the annular groove, and the external communicating passage are connected as a conduit.

[0069] Furthermore, when the protective boot is used as a waterproof protective boot, a stub shaft having an annular protrusion formed on its outer surface that matches the shape of the annular groove is fitted onto the inner surface of the boot fastening part, and the annular protrusion fits into the annular groove, thereby blocking the pipeline consisting of the internal communication groove, the annular groove, and the external communication passage.

[0070] This makes it possible to provide a propeller shaft equipped with a protective boot that can select between an air vent function and a waterproof function.

[0071] The present invention is not limited to the above-described embodiments, but includes various modifications. The above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment. [Explanation of symbols]

[0072] 1...drive shaft, 2...driven shaft, 3...constant velocity joint, 4...support device, 5...drive side tube, 6...cardan joint, 7...stub shaft, 8...driven side tube, 9...constant velocity joint casing, 10...cardan joint, 11...protective boot, 12...boot fixing portion, 13...boot middle portion, 14...boot fastening portion, 17...boot side fitting area portion, 18...boot tip portion, 19...inner circumferential surface, 20...annular groove, 21...internal communicating groove, 22...external communicating groove, 28...shaft side fitting area portion, 30...annular protrusion

Claims

1. A propeller shaft comprising: a first rotating shaft; a constant velocity joint attached to the first rotating shaft; a stub shaft attached to the constant velocity joint; a second rotating shaft attached to the stub shaft; and a protective boot attached to cover the constant velocity joint and the stub shaft from outside, the protective boot includes a boot fixing portion attached to an outer periphery of the constant velocity joint and a boot fastening portion attached to an outer periphery of the stub shaft, An annular groove recessed radially outward is formed on the inner peripheral surface of the boot fastening portion attached to the stub shaft, and an external communication groove communicating from the annular groove to the outside of the protective boot and an internal communication groove communicating from the annular groove to the inside of the protective boot are further formed, When the protective boot is used as a protective boot with an air vent function, a stub shaft having a flat outer peripheral surface is fitted onto the inner peripheral surface of the boot fastening part, so that the internal communication groove, the annular groove, and the external communication groove communicate with each other as a conduit, When the protective boot is used as a protective boot with a waterproof function, the stub shaft, on the outer circumferential surface of which is formed an annular protrusion having a shape matching with the annular groove, is fitted onto the inner circumferential surface of the boot fastening part, and the annular protrusion fits into the annular groove, thereby blocking the conduit consisting of the internal communication groove, the annular groove, and the external communication groove. A propeller shaft characterized by:

2. The propeller shaft according to claim 1, a boot-side fitting area is formed on the inner peripheral surface of the boot fastening portion, and a shaft-side fitting area is formed on the outer peripheral surface of the stub shaft, The boot-side fitting region is formed with the internal communication groove, the annular groove, and the external communication groove. the shaft-side fitting region is formed in a circular flat shape that closes exposed sides of the interior communication groove, the annular groove, and the exterior communication groove, The boot-side fitting region and the shaft-side fitting region are press-fitted to each other. A propeller shaft characterized by:

3. 3. The propeller shaft according to claim 2, A boot band attachment portion to which a boot band is attached is formed on the outer periphery of the boot fastening portion where the boot side fitting region is present, and when the boot band attachment portion is fastened by the boot band, the boot side fitting region is pressed against the shaft side fitting region and comes into close contact. A propeller shaft characterized by:

4. A propeller shaft according to claim 3, The boot band mounting portion has wall portions formed at both ends extending radially outward, and the boot band mounting portion formed by being sandwiched between the wall portions is fastened by the boot band, thereby pressing the boot side mounting area portion 17 inward. A propeller shaft characterized by:

5. 3. The propeller shaft according to claim 2, the external communication groove is formed in a direction away from the constant velocity joint along the axial direction of the stub shaft, The internal communication groove is formed in a direction approaching the constant velocity joint along the axial direction of the stub shaft. A propeller shaft characterized by:

6. 6. A propeller shaft according to claim 5, The cross-sectional area of ​​the external communication groove is smaller than the cross-sectional area of ​​the internal communication groove. A propeller shaft characterized by:

7. 6. A propeller shaft according to claim 5, The number of the external communication groove is one, and the number of the internal communication grooves is two or more. A propeller shaft characterized by:

8. 6. A propeller shaft according to claim 5, The number of the external communication groove is one, and the number of the internal communication grooves is two or more. A propeller shaft characterized by:

9. 3. The propeller shaft according to claim 2, The annular groove is circular, and the internal communication groove and the external communication groove are formed at positions opposite to each other. A propeller shaft characterized by:

10. A propeller shaft according to claim 3, an abutment wall portion extending radially outward is formed on an outer periphery of the stub shaft on a side of the shaft-side fitting region opposite to the side of the constant velocity joint, When the boot band mounting portion is fastened by the boot band, the side surface of the boot-side fitting region is pressed against the front abutment wall portion and tightly adheres to the front abutment wall portion. A propeller shaft characterized by:

11. A propeller shaft according to claim 10, The outer diameter of the shaft-side fitting region is shorter than the outer diameter of the abutting wall portion. A propeller shaft characterized by:

12. A propeller shaft according to claim 11, The abutment wall portion has a flat surface portion extending in a direction away from the constant velocity joint along the axial direction of the stub shaft. A propeller shaft characterized by:

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