Propeller shaft and propeller shaft boot protection member

Abstract

The present invention provides a propeller shaft and a boot protection member for the propeller shaft that can prevent damage to the boot member. The propeller shaft PS according to the present invention is provided with a boot protection member 5 that is detachable from the first rotating member 1. As a result, when the angle of the constant velocity joint 3 changes significantly, the insertion portion 57 of the boot protection member 5 is interposed between the first cover portion 41 and the second cover portion 42. This prevents interference between the first cover portion 41 and the second cover portion 42, thereby preventing damage to the second cover portion 42.

Description

[Technical Field]

[0001] The present invention relates to a propeller shaft and a boot protector for the propeller shaft. [Background technology]

[0002] A conventional propeller shaft is known, for example, from Patent Document 1 below.

[0003] That is, a conventional propeller shaft has an outer ring member connected to a constant velocity joint, a stub shaft connected to an inner ring member disposed on the inner periphery of the outer ring member, and a boot member that seals the gap between the outer ring member and the stub shaft, and the boot member prevents foreign matter from entering the interior of the constant velocity joint. In this case, the boot member has a first metal cover portion connected to the outer ring member, and a second rubber cover portion that folds back from the first cover portion, extends toward the stub shaft, and connects to the stub shaft. [Prior art documents] [Patent documents]

[0004] Patent Document 1: JP 2020-139600 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional propeller shaft described above, when the propeller shaft is delivered to a customer, if the angle change of the constant velocity joint is relatively large, there is a risk that the second cover portion will interfere with the first cover portion of the boot member, resulting in damage to the second cover portion, and therefore there is still room for improvement.

[0006] Therefore, the present invention was devised in consideration of the technical problems of the conventional propeller shafts, and aims to provide a propeller shaft and a boot protection member for the propeller shaft that can suppress damage to the boot member. [Means for solving the problem]

[0007] In one aspect, the present invention is characterized in that a propeller shaft in which a first rotating member and a second rotating member are connected by a constant velocity joint and the constant velocity joint is liquid-tightly protected by a boot member is provided with a boot protection member that is detachable from the first rotating member and surrounds and protects a portion of the boot member. [Effects of the Invention]

[0008] According to the present invention, damage to the boot member can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a half cross-sectional view taken along the rotation axis direction of a propeller shaft according to the present invention. [Figure 2] 1 is an enlarged cross-sectional view of a main portion of a propeller shaft according to a first embodiment of the present invention. FIG. [Figure 3] 1 is an enlarged cross-sectional view of a main portion of a propeller shaft according to a first embodiment of the present invention, showing a state in which a boot protection member is attached. FIG. [Figure 4] 4A and 4B are diagrams showing a boot protection member according to the present invention, in which FIG. 4A is a front view and FIG. 4B is a cross-sectional view taken along line AA of FIG. 4A. [Figure 5] FIG. 2 is an enlarged cross-sectional view of a main part of a propeller shaft for explaining the effects of the first embodiment of the present invention. [Figure 6] FIG. 10 is an enlarged cross-sectional view of a main portion of a propeller shaft according to a second embodiment of the present invention, showing a state in which a boot protection member and a spacer member are attached. [Figure 7] FIG. 7 is a perspective view of the spacer member shown in FIG. 6. [Figure 8] 8A and 8B are cross-sectional views showing the process of inserting a spacer member into a boot protection member, with FIG. 8A showing the state during insertion of the spacer member and FIG. 8B showing the state after insertion of the spacer member. [Figure 9]9A is an enlarged oblique view of a main portion of a propeller shaft showing the process of attaching a boot protection member and a spacer member to the propeller shaft in a second embodiment of the present invention, in which FIG. 9A shows the process of inserting the first longitudinal end of the spacer member between the boot member and the first rotating member, FIG. 9B shows the state just before attaching the boot protection member to the propeller shaft, FIG. 9C shows the state just after attaching the boot protection member to the propeller shaft, and FIG. 9D shows the process of inserting the second longitudinal end of the spacer member into the boot protection member. [Figure 10] 10A and 10B are enlarged perspective views of a main part of a propeller shaft showing a process of removing a boot protection member from the propeller shaft in a second embodiment of the present invention, in which FIG. 10A shows the state before the boot protection member is removed, and FIG. 10B shows the state after the boot protection member has been removed. [Figure 11] 10 is a cross-sectional view showing a state in which the boot protection member holds the spacer member when the boot protection member and the spacer member are detached from the propeller shaft. FIG. [Figure 12] FIG. 10 is a radial cross-sectional view of a propeller shaft according to a modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a propeller shaft and a boot protection member for a propeller shaft according to the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the propeller shaft and the boot protection member for a propeller shaft will be described as being applied to an automobile propeller shaft, as in the prior art.

[0011] (Propeller shaft configuration) Fig. 1 shows the entire propeller shaft PS according to the present invention, and is a half cross-sectional view cut along the rotational axis direction of the propeller shaft. In the following explanation, for convenience, the left side of Fig. 1 will be referred to as the "front" and the right side as the "rear," and the direction along the rotational axis (center of rotation) Z of Fig. 1 will be referred to as the "axial direction," the direction perpendicular to the rotational axis Z as the "radial direction," and the direction around the rotational axis Z as the "circumferential direction."

[0012] 1, for example, a propeller shaft PS according to this embodiment includes a first rotating member 1 connected to a transmission (not shown) mounted on a vehicle, a second rotating member 2 connected to a differential gear (not shown) mounted on the vehicle, and a constant velocity joint 3 that links the first rotating member 1 and the second rotating member 2 so that they can move relative to each other in the axial direction and rotate together. The propeller shaft PS is suspended from the vehicle via a bracket BKT provided on the outer periphery of a center bearing CB that rotatably supports a shaft portion 10 of the first rotating member 1.

[0013] Note that, in this embodiment, a two-piece propeller shaft PS in which the first rotating member 1 and the second rotating member 2 are connected by one constant velocity joint 3 is exemplified, but the propeller shaft according to the present invention is not limited to the above-described two-piece propeller shaft PS configured to be divided into two. In other words, the propeller shaft according to the present invention may be configured to be divided into three or more pieces in which the first rotating member 1 connected to the not-shown transmission and the second rotating member 2 connected to the not-shown differential gear are connected via, for example, multiple constant velocity joints.

[0014] The first rotating member 1 is connected to the transmission (not shown) via a first joint (for example, a Cardan joint shown in FIG. 1) J1, while the second rotating member 2 is connected to a differential gear (not shown) via a second joint (for example, a Cardan joint shown in FIG. 1) J2.

[0015] The first joint J1 and the second joint J2 that connect the propeller shaft PS and the vehicle (the transmission and differential gear not shown) are not limited to the Cardan joints exemplified in this embodiment. In other words, the first joint J1 and the second joint J2 may be any shaft couplings that can connect the propeller shaft PS and the vehicle (the transmission and differential gear not shown), and may be arbitrarily changed depending on the specifications of the propeller shaft PS, etc. That is, in addition to universal joints such as the Cardan joints, flexible shaft couplings such as rubber couplings may also be used as the first joint J1 and the second joint J2.

[0016] (Constant velocity joint configuration) FIG. 2 is an enlarged view of a main portion of the propeller shaft PS according to the present invention, showing an enlarged view of the vicinity of the constant velocity joint 3 in the propeller shaft PS.

[0017] For example, as shown in Figure 2, the first rotating member 1 has a shaft portion 10 at its rear end that extends axially toward the second rotating member 2. A male spline portion 12 that engages with an inner ring member 31 of a constant velocity joint 3 is provided at the tip of the shaft portion 10. The male spline portion 12 is formed in a stepped shape with a reduced diameter from the general portion 11 via a step portion 13 behind the general portion 11.

[0018] The shaft portion 10 is also provided with a boot mounting portion 14, located forward of the general portion 11, for mounting and fixing a second cover portion 42 of the boot member 4, which will be described later. The boot mounting portion 14 is formed with a stepped diameter that is larger than the general portion 11, and a boot fixing recess 140, located in a middle portion of the boot mounting portion 14 and having a stepped diameter that is smaller than the general portion 11, is formed. The boot fixing recess 140 is formed in a stepped recess shape between a first expanded diameter portion 141 that expands in a stepped diameter forward of the boot fixing recess 140, and a second expanded diameter portion 142 that expands in a stepped diameter rearward of the boot fixing recess 140.

[0019] The second rotating member 2 is formed in a cylindrical shape with a cylindrical portion 20 as its main component. The cylindrical portion 20 has a generally constant inner diameter in the axial direction on the first end 21 side, and a stepped diameter on the second end 22 side relative to the first end 21. A vibration-proof member DP, such as a well-known dynamic damper, is attached to the inner periphery of the cylindrical portion 20. This suppresses noise and vibration of the propeller shaft PS due to vibration of the second rotating member 2.

[0020] The constant velocity joint 3 includes an axial inner ring member 31 connected to the first rotating member 1, a cylindrical outer ring member 32 arranged on the outer peripheral side of the inner ring member 31, and a plurality of ball members 33 as rolling elements held in a rollable state via an annular cage 34 arranged between the inner ring member 31 and the outer ring member 32. A bearing accommodating space BS formed inside the outer ring member 32 is filled with grease (not shown) that lubricates the constant velocity joint 3. For this reason, a cylindrical boot member 4 is provided between the first rotating member 1 and the outer ring member 32 so as to straddle the first rotating member 1 and the outer ring member 32. In other words, by covering the connection portion between the first rotating member 1 and the outer ring member 32 with the boot member 4, the bearing accommodating space BS is kept airtight, and good lubrication of the constant velocity joint 3 is maintained.

[0021] The inner ring member 31 has a cylindrical shape and is formed with a shaft insertion hole 311 penetrating the inner periphery thereof, into which the first rotating member 1 is inserted. The inner periphery of the shaft insertion hole 311 is formed with a female spline portion 312 into which the male spline portion 12 of the first rotating member 1 can be fitted. The outer periphery of the inner ring member 31 is formed with a plurality of inner race grooves 313 extending linearly along the axial direction and spaced equally apart in the circumferential direction. The inner race grooves 313 cooperate with outer race grooves 323, which will be described later, to restrict circumferential movement of the ball members 33 while permitting axial movement of the ball members 33.

[0022] The male spline portion 12 of the first rotating member 1 has a circlip fitting groove 15 into which a circlip SR can be fitted, at an axial position corresponding to the rear end edge (the edge on the second rotating member 2 side) of the inner ring member 31 when the inner ring member 31 is abutted against the step portion 13. That is, the inner ring member 31 is held between the step portion 13 and the circlip SR, and the rear end edge of the inner ring member 31 is locked with the circlip SR, thereby preventing the first rotating member 1 from coming off the inner ring member 31.

[0023] The outer ring member 32 has a cylindrical bearing component 321 that houses the inner ring member 31 on its inner peripheral side to form the constant velocity joint 3, and a connection base 322 that is provided at the rear end of the bearing component 321 and is connected to the second rotating member 2 (cylindrical portion 20). The bearing component 321 and the connection base 322 are integrally formed by forging an iron-based material, for example.

[0024] The bearing component 321 is formed in a cylindrical shape with generally constant inner and outer diameters, and is formed as a cylinder with an open front end and a closed rear end that is closed by a sealing plug 324. A plurality of outer race grooves 323 extending linearly along the axial direction are formed at equal intervals in the circumferential direction on the inner peripheral side of the bearing component 321. The outer race grooves 323 cooperate with the inner race grooves 313 to restrict circumferential movement of the ball members 33 while allowing axial movement of the ball members 33.

[0025] Thus, in the bearing component 321, the ball members 33 roll in the axial direction along the race grooves formed between the inner race groove 313 and the outer race groove 323, thereby allowing relative movement in the axial direction between the inner ring member 31 and the outer ring member 32. Meanwhile, in the bearing component 321, the ball members 33 engage in the race grooves formed between the inner race groove 313 and the outer race groove 323 in the circumferential direction, thereby restricting relative movement, i.e., relative rotation, between the inner ring member 31 and the outer ring member 32 in the circumferential direction, and the inner ring member 31 and the outer ring member 32 rotate together based on the driving torque input from the inner ring member 31 side.

[0026] The connection base 322 is provided at the rear end of the bearing component 321 so as to protrude axially rearward beyond the sealing plug 324, and is formed in a cylindrical shape that is open at the rear end. Specifically, the connection base 322 is formed in a stepped shape with respect to the bearing component 321, and has an outer diameter equivalent to that of the second rotating member 2. The connection base 322 is connected to the second rotating member 2 by so-called friction welding. Note that, due to this friction welding, a curled portion 322a that bulges inward and outward in the radial direction is formed in an annular shape along the circumferential direction at the connection portion of the connection base 322 to the second rotating member 2 by the friction welding.

[0027] The boot member 4 has a cylindrical shape with a folded-back axial middle portion, and includes a metallic first cover portion 41 fixed to the outer peripheral side of the outer ring member 32, and a second cover portion 42 formed of a flexible elastic material such as rubber, and fixed to a boot fixing recess 140 of the first rotating member 1 via a boot band 43. The boot member 4 is mounted so as to straddle between the first rotating member 1 and the outer ring member 32, and is configured to be expandable and contractible in the axial direction due to the folded-back second cover portion 42 located at the axial middle portion.

[0028] One axial end of the first cover portion 41 extends in a direction (forward) approaching the first rotating member 1, and the other axial end is fixed by crimping to the outer periphery of the outer ring member 32. Specifically, a first end 411 of the first cover portion 41 is formed by folding back in a generally hook shape and is fixed by crimping to one end of the second cover portion 42 so as to sandwich one end of the second cover portion 42. On the other hand, a second end 412 of the first cover portion 41 is crushed radially inward into a concave shape and is fixed by crimping to the outer periphery of the outer ring member 32 so as to be in pressure contact with an annular recess 325 formed as a recess along the circumferential direction on the outer periphery of the outer ring member 32.

[0029] One axial end of the second cover part 42 is folded back in a U-shape from the first end 411 of the first cover part 41 and accommodated on the inner circumferential side of the outer ring member 32, and the other end is fixed to the boot fastening recess 140 of the first rotating member 1. Specifically, the first end 421 of the second cover part 42 is connected to the first end 411 of the first cover part 41, and the second end 422 extends forward along the shaft part 10 of the first rotating member 1 so as to make a U-turn from the first end 421 via a bent part 423, and is tightly fixed to the boot fastening recess 140 by the boot band 43.

[0030] The second end 422, which is tightly bound by the boot band 43, is formed relatively thick, and an air vent groove 424 is formed on the inner circumferential side that is in close contact with the boot fastening recess 140. The air vent groove 424 connects the inside and outside of the boot member 4, which is sealed by the boot member 4, thereby reducing the pressure inside the bearing accommodation space BS. The air vent groove 424 includes a pair of axial grooves 424a, 424b and a circumferential groove 424c that connects the pair of axial grooves 424a, 424b. The pair of axial grooves 424a, 424b are formed at different circumferential positions and each extends linearly along the axial direction. The circumferential groove 424c is provided between the pair of axial grooves 424a, 424b so as to extend circumferentially and connect the pair of axial grooves 424a, 424b.

[0031] Additionally, the second end 422 of the boot member 4 is provided with an extension 425 that extends forward and comes into contact with the shaft portion 10 of the first rotating member 1 adjacent to the boot fixing recess 140. The extension 425 is formed in a generally cylindrical shape that continues in the circumferential direction so as to surround the shaft portion 10 of the first rotating member 1, and by coming into contact with the shaft portion 10 of the first rotating member 1, foreign matter such as moisture and dust is prevented from directly entering the ventilation groove 424. At this time, no preload is applied to the extension 425 to press the extension 425 against the shaft portion 10 of the first rotating member 1, and the internal pressure of the bearing accommodating space BS is ensured to be discharged through the ventilation groove 424.

[0032] [First embodiment] (Configuration of boot protection member) Fig. 3 shows a first embodiment of a boot protection member 5 for a propeller shaft according to the present invention, and is an enlarged cross-sectional view of a main portion of the propeller shaft PS in which the boot protection member 5 according to this embodiment is attached to the propeller shaft PS shown in Fig. 2. Fig. 4 shows the boot protection member 5 alone, with Fig. 4A being a front view and Fig. 4B being a cross-sectional view taken along line AA in Fig. 4A.

[0033] For example, as shown in Figures 3 and 4, the boot protection member 5 is integrally formed from, for example, a resin material or a rubber material, and includes a tubular portion 51 that surrounds the outer periphery of the first rotating member 1 and a plurality of (two in this embodiment) protruding portions 52 that protrude radially toward the outer periphery of the tubular portion 51.

[0034] The tubular portion 51 has a generally cylindrical shape and is detachably attached to the shaft portion 10 of the first rotating member 1. The tubular portion 51 is attached so as to straddle the first rotating member 1 and the boot member 4. Specifically, the tubular portion 51 has a notch 53 formed along the radial direction on the opposite side of the pair of protrusions 52 across the rotation axis Z, and is configured so that the notch 53 on the opposite side opens when the pair of protrusions 52 are pinched. Furthermore, in an axial region near the rear end of the tubular portion 51, a recess 58 is formed along the circumferential direction on the inner peripheral side of the tubular portion 51 to avoid the boot band 43. The recess 58 has a rectangular groove shape recessed in a stepped shape in an axial cross section, and has an inner diameter set to be slightly larger than the outer diameter of the boot band 43 wound around the boot member 4.

[0035] The pair of protrusions 52 protrude radially from both sides of the cylindrical portion 51 and are provided so as to be generally symmetrical with respect to a center line Q that passes through the rotation axis Z and overlaps with line AA in Fig. 4A. Note that it is sufficient for the pair of protrusions 52 to be provided in a partial axial region of the cylindrical portion 51, as shown in Fig. 4B, and they do not need to be provided over the entire axial region of the cylindrical portion 51. Furthermore, the pair of protrusions 52 are formed so that each circumferential width dimension Wp gradually increases toward the base side, and the distance Dp between the protrusions 52 gradually decreases toward the base side, forming a so-called tapered shape.

[0036] Furthermore, a slit portion 54 is formed between the base portions of the pair of protrusions 52, penetrating the pair of protrusions 52 in the axial direction so as to straddle the pair of protrusions 52. The slit portion 54 has a rectangular shape that is generally symmetrical with respect to the center line Q, and communicates with the outside through an opening OP formed between the pair of protrusions 52. The circumferential width W of the slit portion 54 is set larger than the circumferential width D of the opening OP, and this dimensional relationship and the tapered shape of both protrusions 52 form a pair of protrusions 55 that protrude inward so as to face each other at the base portions of the pair of protrusions 52 that form the opening OP.

[0037] Furthermore, arc-shaped recessed notches 56 are formed on the outer sides of the bases of the pair of protrusions 52. That is, the notches 56 reduce the rigidity of the bases of the pair of protrusions 52, and the pair of protrusions 52 are configured to tilt inward easily when pinched from the outside. In other words, because the pair of protrusions 52 are configured to be able to tilt inward relatively easily, the notches 53 formed on the opposite sides of the pair of protrusions 52 across the rotation axis Z are configured to open wider.

[0038] Furthermore, an insertion portion 57 is provided at the rear end of the tubular portion 51, which is inserted between the first cover portion 41 and the second cover portion 42. The insertion portion 57 is formed in a tapered shape that tapers off toward the tip end so that the outer periphery does not have a sharp shape. This prevents the boot member 4 from being damaged due to interference between the insertion portion 57 and the boot member 4. Here, the tapered shape provided on the insertion portion 57 does not need to be formed over the entire axial region of the insertion portion 57, and may be formed in only a portion of the axial region of the insertion portion 57, such as only the tip end of the insertion portion 57 that may interfere with the boot member 4.

[0039] The notch 53 has a contact portion 531 that is provided radially inward and contacts the boot protection member 5 in a free state, and a separation portion 532 that is provided radially outward of the contact portion 531 and is spaced apart and non-contacting in the free state of the boot protection member 5. The separation portion 532 has a V-shaped opening that opens radially outward and has a tapered shape in which the opening width increases radially outward. Note that, as shown in FIG. 4B , it is sufficient for the separation portion 532 to be provided in a partial axial region of the tubular portion 51 on the opposite side of the pair of protrusions 52 with respect to the rotation axis Z, and it is not necessary for the separation portion 532 to be provided over the entire axial region of the tubular portion 51.

[0040] (Effects of this embodiment) In the conventional propeller shaft described above, when the propeller shaft is delivered to a customer, if the angle change of the constant velocity joint 3 is relatively large, the rubber second cover portion 42 of the boot member 4 may interfere with the metal first cover portion 41, which may result in damage to the second cover portion 42, and therefore there is room for improvement.

[0041] In contrast, the propeller shaft PS and the propeller shaft boot protection member 5 according to this embodiment provide the following advantageous effects, thereby solving the problems of the conventional propeller shafts.

[0042] The propeller shaft PS according to this embodiment is a propeller shaft used in an automobile, and includes: a first rotating member 1; a second rotating member 2 to which rotation of the first rotating member 1 is transmitted; a constant velocity joint 3 provided between the first rotating member 1 and the second rotating member 2 in an axial direction along the rotation axis Z of the first rotating member 1, the constant velocity joint 3 having an inner ring member 31 connected to the first rotating member 1 and an outer ring member 32 connected to the second rotating member 2 and to which rotation is transmitted via a ball member 33 arranged on the outer peripheral side of the inner ring member 31; a boot member provided between the first rotating member 1 and the outer ring member 32, the first end 411 extending in a direction approaching the first rotating member 1 in the axial direction and the second end 412 fixed to the outer peripheral side of the outer ring member 32; and a boot protection member 5 that protects the boot member 4 and is detachable from the first rotating member 1, the boot protection member 5 having a tubular portion 51 that surrounds the outer periphery of the first rotating member 1, an insertion portion 57 that is inserted between the first cover portion 41 and the second cover portion 42 of the tubular portion 51, a plurality of protrusions 52 that protrude toward the outer periphery of the tubular portion 51 in a radial direction perpendicular to the rotation axis Z, a cutout portion 53 that is provided in the tubular portion 51 on the opposite side of the plurality of protrusions 52 across the rotation axis Z from the plurality of protrusions 52, and a slit portion 54 that is provided between the plurality of protrusions 52 in the circumferential direction of the rotation axis Z and that penetrates in the axial direction.

[0043] As described above, according to this embodiment, the boot protection member 5 is provided detachably to the first rotating member 1. Therefore, as shown in FIG. 5, for example, when the angle change of the constant velocity joint 3 becomes large, the insertion portion 57 of the boot protection member 5 is interposed between the first cover portion 41 and the second cover portion 42. This prevents interference between the first cover portion 41 and the second cover portion 42, and prevents damage to the second cover portion 42.

[0044] In this embodiment, the notches 53 are formed in a tapered shape such that the width dimension in the circumferential direction increases toward the outside in the radial direction.

[0045] In this manner, in this embodiment, the notch 53 is formed in a tapered shape that widens radially outward, which makes it easy to prepare a mold for molding the boot protection member 5 and also improves the mold releasability of the boot protection member 5 during molding.

[0046] Furthermore, because the cutout portion 53 is formed in a tapered shape, when the boot protection member 5 is attached to the first rotating member 1, the tapered cutout portion 53 can easily open along the outer surface of the first rotating member 1. This makes it even easier to attach the boot protection member 5 to the first rotating member 1 through the cutout portion 53.

[0047] Second Embodiment 6 to 11 show a second embodiment of a propeller shaft PS and a boot protection member 5 for the propeller shaft according to the present invention, which is mainly obtained by adding a spacer member 6 to the boot protection member 5 according to the first embodiment. Note that the basic configuration other than the above changes is the same as that of the first embodiment, and therefore the same components as those of the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0048] (Configuration of spacer member) Fig. 6 shows a second embodiment of a propeller shaft PS and a boot protection member 5 for the propeller shaft PS according to the present invention, and is an enlarged cross-sectional view of a main portion of the propeller shaft PS in which a spacer member 6 is attached to the propeller shaft PS shown in Fig. 3 via the boot protection member 5. Fig. 7 shows a perspective view of the spacer member 6 shown in Fig. 6.

[0049] 6, the propeller shaft PS according to this embodiment is provided with a spacer member 6 that can ensure the release of internal pressure in the boot member 4 through the ventilation grooves 424 and the extensions 425 of the boot member 4. The spacer member 6 is an extremely thin, flat, strip-shaped string member (for example, a well-known PP band) made of a relatively hard resin material, such as a plastic material. The spacer member 6 has a constant width in the longitudinal direction, with the maximum dimension Wx of its circumferential width W being larger than the circumferential width D of the opening OP of the boot protection member 5, and its middle portion is bent at a substantially right angle (L-shaped) in a free state.

[0050] Here, the spacer member 6 may be made of, for example, a metal material (such as aluminum or stainless steel) in addition to the above-mentioned relatively hard resin material. In other words, it is sufficient for the spacer member 6 to be able to be pushed into the extension portion 425 of the boot member 4 from the axial direction against the extension portion 425, that is, to have relatively higher rigidity than the extension portion 425, and is not limited to the materials exemplified above.

[0051] Specifically, the first longitudinal end 61 of the spacer member 6 is inserted axially between the first enlarged diameter portion 141 of the first rotating member 1 and the extended portion 425 of the boot member 4. As a result, the first longitudinal end 61 of the spacer member 6 acts to lift a circumferential portion of the extended portion 425, forming a gap S between the first enlarged diameter portion 141 of the first rotating member 1 and the extended portion 425 of the boot member 4. When the axial length of the propeller shaft PS is temporarily shortened via the constant velocity joint 3 during installation of the propeller shaft PS on a vehicle, this gap S cooperates with the ventilation groove 424 to effectively discharge the internal pressure that increases in the boot member 4 as the axial length of the propeller shaft PS is shortened.

[0052] On the other hand, the second longitudinal end 62 of the spacer member 6 passes through the inside of the tubular portion 51 of the boot protection member 5 and faces outward from the front end side, and is then bent so as to fold back toward the opposite axial direction (rear side) and inserted into the slit portion 54 of the boot protection member 5. The spacer member 6 inserted into the slit portion 54 abuts against the upper surface of the slit portion 54 (the lower ends of the pair of protrusions 55) due to the elastic force caused by the bending, and is held in place by the frictional force generated between the slit portion 54 and the spacer member 6 within the slit portion 54.

[0053] (Configuration of boot protection member) 8A and 8B are cross-sectional views showing the process of inserting the spacer member 6 into the boot protection member 5, with Fig. 8A showing the state during insertion of the spacer member 6 and Fig. 8B showing the state after insertion of the spacer member 6. In addition, in describing the details of the configuration of the boot protection member 5, Fig. 4 will be referred to as appropriate in addition to Fig. 8.

[0054] As shown in FIG. 4A, the slit portion 54 has a rectangular shape extending in the circumferential direction, with a circumferential width W, which is the width in the short side direction, set larger than a radial width H. The slit portion 54 also has a circumferential width W set larger than a circumferential width D of the opening OP, and is formed to have a stepped width wider than the opening OP. Here, the slit portion 54 is formed such that, as viewed in the axial direction (see FIG. 4A), a maximum distance Dx between a first circumferential end OP1 of the opening OP and a first circumferential end 541, which is the end of the slit portion 54 farther from the first circumferential end OP1 of the opening OP, is larger than a maximum dimension Wx of the circumferential width W of the spacer member 6. As a result, the spacer member 6 can be inserted into the slit portion 54 in the axial direction, or, as shown in FIG. 8, for example, can be inserted into the slit portion 54 in the radial direction via the opening OP.

[0055] 8A, the second longitudinal end 62 of the spacer member 6 is inserted obliquely into the opening OP from the first circumferential end 621 side until the first circumferential end 621 abuts against the first circumferential end 541 of the slit portion 54. Thereafter, while maintaining the abutting state of the first circumferential end 621, the second circumferential end 622 of the spacer member 6 is rotated downward with the abutment point of the first circumferential end 621 as a fulcrum, and as a result, the second circumferential end 622 is also accommodated in the slit portion 54, as shown in FIG. 8B. As a result, the entire second longitudinal end 62 of the spacer member 6 is accommodated in the slit portion 54.

[0056] (Installation procedure for spacer and boot protection parts) Figure 9 is an enlarged oblique view of a key portion of the propeller shaft PS showing the process of attaching a boot protection member 5 and a spacer member 6 to the propeller shaft PS in this embodiment, where Figure 9A shows the process of inserting the first longitudinal end 61 of the spacer member 6 between the extension portion 425 of the boot member 4 and the shaft portion 10 (first enlarged diameter portion 141) of the first rotating member 1, Figure 9B shows the process of attaching the boot protection member 5 to the propeller shaft PS, showing the state just before the boot protection member 5 is attached, Figure 9C shows the process of attaching the boot protection member 5 to the propeller shaft PS, showing the state just after the boot protection member 5 is attached, and Figure 9D shows the process of inserting the second longitudinal end 62 of the spacer member 6 into the slit portion 54 of the boot protection member 5.

[0057] 9A, the first longitudinal end 61 of the spacer member 6 bent into an L shape is inserted axially along the shaft portion 10 between the first enlarged diameter portion 141 of the first rotating member 1 and the extension portion 425 of the boot member 4. As a result, a gap S (see FIG. 6) is formed between the first enlarged diameter portion 141 of the first rotating member 1 and the extension portion 425 of the boot member 4 by the inserted first longitudinal end 61 of the spacer member 6.

[0058] 9B, the pair of protrusions 52 of the boot protection member 5 are pinched in a predetermined axial region spanning the first longitudinal end portion 61 of the spacer member 6 and the second cover portion 42 of the boot member 4, thereby opening the cutout portion 53 vertically downward. Here, the predetermined axial region is the axial position where the recess 58 of the boot protection member 5 overlaps with the boot band 43 (see FIG. 6).

[0059] 9C , the tubular portion 51 is fitted into an axial region spanning the first longitudinal end portion 61 of the spacer member 6 and the second cover portion 42 of the boot member 4 through the open cutout portion 53. Specifically, the tubular portion 51 is pressed into the axial region with the cutout portion 53 pressed against the outer circumferential surface of the axial region of the propeller shaft PS. That is, by being pressed from above, the tubular portion 51 is fitted into the axial region by expanding the cutout portion 53 along the tapered shape of the cutout portion 53.

[0060] After the boot protection member 5 is attached to the propeller shaft PS, as shown in Fig. 9D, the second longitudinal end 62 of the spacer member 6 is inserted into the slit portion 54 through the opening OP. Specifically, as described above with reference to Fig. 8, the first circumferential end 621 of the second longitudinal end 62 of the spacer member 6 is inserted obliquely from above the opening OP (see Fig. 8A), and with the first circumferential end 621 abutting against the first circumferential end 541 of the slit portion 54, the second circumferential end 622 of the spacer member 6 is rotated downward with the abutment point as a fulcrum (see Fig. 8B), whereby the entire second longitudinal end 62 of the spacer member 6 is accommodated in the slit portion 54. In this way, the propeller shaft PS is packaged in the state in which it is shipped.

[0061] (Procedure for removing the spacer and boot protection parts) Fig. 10 is an enlarged perspective view of a main portion of the propeller shaft PS showing the process of removing the boot protection member 5 from the propeller shaft PS according to this embodiment, Fig. 10A shows the state before the boot protection member is removed, and Fig. 10B shows the state after the boot protection member has been removed. Also, Fig. 11 is a cross-sectional view showing the state in which the boot protection member 5 holds the spacer member 6 when the boot protection member 5 and the spacer member 6 are detached from the propeller shaft PS.

[0062] First, as shown in Fig. 10A, the pair of protrusions 52 of the boot protection member 5 are pinched to open the cutouts 53 vertically downward. Next, the pair of protrusions 52 are pinched and pulled up vertically upward, thereby pushing and spreading the cutouts 53 along the outer surface of the shaft portion 10, and the boot protection member 5 is detached from the propeller shaft PS, as shown in Fig. 10B.

[0063] Here, when the boot protection member 5 is detached, the pair of protrusions 52 are pinched, and as shown in Fig. 11, the pair of protrusions 55 rotate downward and move closer to each other until they abut against each other, thereby closing the opening OP. Furthermore, as the pair of protrusions 55 move closer to each other, both circumferential ends 541, 542 of the slit portion 54 move closer to each other, and both circumferential ends 621, 622 of the spacer member 6 are sandwiched between both circumferential ends 541, 542 of the slit portion 54. Furthermore, as the pair of protrusions 55 rotate downward, the spacer member 6 is pressed against the bottom side of the slit portion 54 by both protrusions 55.

[0064] In this way, due to the organic relationship between multiple actions, the second longitudinal end 62 side of the spacer member 6 is gripped by the boot protection member 5, and the second longitudinal end 62 of the spacer member 6 is prevented from falling off from the slit portion 54. As a result, the spacer member 6 becomes one with the boot protection member 5 and separates from the propeller shaft PS following the boot protection member 5 (see FIG. 10B).

[0065] (Effects of this embodiment) The propeller shaft PS of this embodiment is provided with a spacer member 6 inserted between the first rotating member 1 (first enlarged diameter portion 141) and the boot member 4 (extension portion 425), and the first longitudinal end 61 of the spacer member 6 is inserted between the first rotating member 1 (first enlarged diameter portion 141) and the boot member 4 (extension portion 425) through the inside of the tubular portion 51, and the second longitudinal end 62 of the spacer member 6 is folded back from the end of the tubular portion 51 opposite the second rotating member 2 and inserted into the slit portion 54.

[0066] As described above, in this embodiment, the first longitudinal end 61 of the spacer member 6 is inserted between the first expanded diameter portion 141 of the first rotating member 1 and the extension 425 of the boot member 4. That is, by inserting the spacer member 6 and lifting the extension 425 of the boot member 4, a gap S is formed between the first expanded diameter portion 141 of the first rotating member 1 and the extension 425 of the boot member 4. This gap S improves the breathability of the boot member 4 and enables the internal pressure of the boot member 4 that has been released through the ventilation groove 424 to be efficiently discharged. This facilitates relative movement between the first rotating member 1 and the second rotating member 2, making it possible to easily contract the propeller shaft PS in the axial direction when installing the propeller shaft PS to a vehicle, thereby improving the ease of installation of the propeller shaft PS to a vehicle.

[0067] On the other hand, the second longitudinal end 62 side of the spacer member 6 is folded back and inserted into the slit portion 54. As a result, the second longitudinal end 62 side of the spacer member 6 is held in the slit portion 54, and unintentional detachment of the spacer member 6 can be prevented.

[0068] In this embodiment, the spacer member 6 is a belt-like string member.

[0069] As described above, in this embodiment, the spacer member 6 is configured of a belt-like string member. This allows the spacer member 6 to be formed with a thin wall. This makes it possible to prevent excessive deformation of the extension portion 425 of the boot member 4 into which the spacer member 6 is inserted.

[0070] In this embodiment, the spacer member 6 is made of a plastic material or a metal material.

[0071] In this way, in this embodiment, the spacer member 6 is formed from a plastic material or a metal material, which makes it possible to ensure a certain level of rigidity for the spacer member 6, and makes it easy to insert the spacer member 6 into the extension portion 425 of the boot member 4.

[0072] Furthermore, because the spacer member 6 is formed from a relatively hard material such as a plastic material or a metal material, the second longitudinal end 62 elastically abuts against the upper surface of the slit portion 54 due to the reaction force caused by the bending. As a result, the second longitudinal end 62 of the spacer member 6 is held in the slit portion 54 by the frictional force generated between the spacer member 6 and the slit portion 54. As a result, the holding ability of the spacer member 6 in the slit portion 54 is improved, and the problem of the second longitudinal end 62 of the spacer member 6 falling off from the slit portion 54 can be more effectively prevented.

[0073] In this embodiment, the slit portion 54 has a rectangular shape in which the length in the circumferential direction is relatively longer than the length in the radial direction when viewed from the axial direction.

[0074] As described above, in this embodiment, the circumferential width W of the slit portion 54 is set to be relatively large with respect to the radial width H. This makes it possible to suppress movement of the spacer member 6 within the slit portion 54. This makes it possible to suppress the problem of the spacer member 6 suddenly falling off.

[0075] In this embodiment, the slit portion 54 has an opening OP that opens in the radial direction.

[0076] As described above, in this embodiment, an opening OP that opens in the radial direction is provided in the slit portion 54. Therefore, the second longitudinal end portion 62 side of the spacer member 6 can be folded back relatively largely, and the spacer member 6 can be inserted into the slit portion 54 through the opening OP. This makes it easy to insert the spacer member 6 into the slit portion 54.

[0077] In particular, in this embodiment, the slit portion 54 is set to the minimum size necessary to limit the degree of freedom of the spacer member 6, while the spacer member 6 is formed relatively hard to ensure a certain level of rigidity. Therefore, the workability of inserting the spacer member 6 can be greatly improved compared to when the second longitudinal end portion 62 side of the spacer member 6 is folded back relatively slightly and inserted into the slit portion 54 from the axial direction.

[0078] In addition, in this embodiment, in a cross section viewed from the axial direction, the maximum width dimension (maximum dimension Wx of the circumferential width W) of the spacer member 6 is set to be larger than the width dimension (circumferential width D) of the opening OP.

[0079] As described above, in this embodiment, the maximum dimension Wx of the circumferential width W of the spacer member 6 is set to be larger than the circumferential width D of the opening OP. Therefore, after the spacer member 6 is inserted into the slit portion 54, it is possible to prevent the spacer member 6 from falling out of the slit portion 54 through the opening OP. This improves the retention of the spacer member 6 within the slit portion 54, and allows the spacer member 6 to be stably housed and retained in the boot protection member 5.

[0080] In addition, in this embodiment, the slit portion 54 is stepped in width relative to the opening OP, and in a cross section viewed from the axial direction, the maximum distance Dx between one circumferential end portion (circumferential first end portion OP1) of the opening OP and the circumferential end portion (circumferential first end portion 541) of the slit portion 54 that is farther from the one circumferential end portion (circumferential first end portion OP1) of the opening OP is greater than the maximum circumferential dimension Wx of the spacer member 6.

[0081] As described above, in the present embodiment, the maximum dimension Wx of the circumferential width W of the spacer member 6 is set to be larger than the circumferential width D of the opening OP, and the maximum distance Dx between the first circumferential end OP1 of the opening OP and the first circumferential end 541, which is the end of the slit portion 54 farther from the first circumferential end OP1 of the opening OP, is formed to be larger than the maximum dimension Wx of the circumferential width W of the spacer member 6. Therefore, it is possible to effectively prevent the spacer member 6 from falling off through the opening OP, and also to easily insert the spacer member 6 into the slit portion 54 through the opening OP without bending it in the circumferential direction (width direction). Specifically, due to the above-mentioned dimensional relationship, by abutting the first circumferential end 621 of the spacer member 6 against the first circumferential end 541 of the slit portion 54 that is far from the first circumferential end OP1 of the opening OP, and then rotating the second circumferential end 622 of the spacer member 6 downward, the spacer member 6 can be easily inserted into the slit portion 54 through the opening OP without the second circumferential end 622 of the spacer member 6 interfering with the first circumferential end OP1 of the opening OP.

[0082] (Variation) 12 shows a modified example of the second embodiment of the propeller shaft PS and the propeller shaft boot protection member 5 according to the present invention, in which the cross-sectional shape of the spacer member 6 according to the second embodiment is mainly changed. Note that the basic configuration other than this change is the same as that of the second embodiment, and therefore the same components as those of the second embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0083] That is, in the propeller shaft PS according to this modified example, as shown in FIG. 12, the first longitudinal end 61 side of the spacer member 6 inserted inside the extension portion 425 of the boot member 4 is curved circumferentially along the outer peripheral surface of the shaft portion 10 so that the cross section perpendicular to the longitudinal direction is roughly arc-shaped.

[0084] As described above, in this modified example, the spacer member 6 is formed to have an arc-shaped cross section.

[0085] With this configuration, the first longitudinal end 61 of the spacer member 6 can be easily inserted between the first enlarged diameter portion 141 of the first rotating member 1 and the extension portion 425 of the boot member 4 along the outer peripheral surface of the first rotating member 1, which has an approximately circular cross section.

[0086] Furthermore, by forming the spacer member 6 in an arc shape that follows the shaft portion 10 of the cylindrical first rotating member 1, damage to the extension portion 425 of the boot member 4 that occurs when the spacer member 6 is inserted can be reduced compared to when the spacer member 6 is formed in a flat plate shape as in the second embodiment.

[0087] The present invention is not limited to the configurations and aspects exemplified in the above-described embodiments, etc., and can be freely modified depending on the specifications, cost, etc. of the propeller shaft to which it is applied, as long as the configuration can achieve the above-described effects of the present invention.

[0088] In addition, while the above-described embodiment and the like have exemplified a configuration in which the inner ring member 31 is disposed on the front end side, i.e., the driving side, and the outer ring member 32 is disposed on the rear end side, i.e., the driven side, the reverse configuration may also be used. In other words, the present invention is also applicable to a configuration in which the outer ring member 32 is disposed on the front end side, i.e., the driving side, and the inner ring member 31 is disposed on the rear end side, i.e., the driven side. In addition, the rolling elements of the constant velocity joint 3 are not limited to ball members. [Explanation of symbols]

[0089] 1...first rotating member, 10...shaft portion, 2...second rotating member, 3...constant velocity joint, 31...inner ring member, 32...outer ring member, 33...ball, 4...boot member, 41...first cover portion, 42...second cover portion, 5...boot protection member, 51...tubular portion, 52...projection portion, 53...notch portion, 54...slit portion, 6...spacer member, OP...opening, PS...propeller shaft, Z...rotation axis

Claims

1. A propeller shaft for use in an automobile, a first rotating member; a second rotating member to which rotation of the first rotating member is transmitted; a constant velocity joint provided between the first rotating member and the second rotating member in an axial direction along a rotation axis of the first rotating member, an inner ring member connected to the first rotary member; an outer ring member connected to the second rotating member and to which rotation is transmitted via rolling elements arranged on the outer peripheral side of the inner ring member; the constant velocity joint having a boot member provided between the first rotating member and the outer ring member, a first cover portion having a first end portion extending in the axial direction toward the first rotating member and a second end portion fixed to an outer circumferential side of the outer ring member; a second cover portion having a first end portion folded back from the first cover portion in the axial direction and disposed on an inner peripheral side of the outer ring member, and a second end portion fixed to the first rotating member; the boot member having a boot protection member that protects the boot member and is detachable from the first rotating member, the boot protection member having a tubular portion surrounding the outer periphery of the first rotating member, an insertion portion inserted into the tubular portion between the first cover portion and the second cover portion, a plurality of protruding portions protruding toward the outer periphery of the tubular portion in a radial direction perpendicular to the rotation axis, a notch portion provided on the tubular portion on the opposite side of the rotation axis from the plurality of protruding portions, and a slit portion provided between the plurality of protruding portions in the circumferential direction of the rotation axis and penetrating in the axial direction; A propeller shaft comprising:

2. 2. The propeller shaft according to claim 1, a spacer member inserted between the first rotary member and the boot member; a first end portion of the spacer member in the longitudinal direction is inserted between the first rotary member and the boot member through the inside of the cylindrical portion; a second longitudinal end portion of the spacer member is folded back from an end portion of the cylindrical portion opposite to the second rotary member and inserted into the slit portion; A propeller shaft characterized by:

3. 3. The propeller shaft according to claim 2, The spacer member is a belt-shaped string member. A propeller shaft characterized by:

4. 3. The propeller shaft according to claim 2, The spacer member is made of a plastic material or a metal material. A propeller shaft characterized by:

5. 3. The propeller shaft according to claim 2, The spacer member has an arc-shaped cross section. A propeller shaft characterized by:

6. 3. The propeller shaft according to claim 2, When viewed from the axial direction, the slit portion has a rectangular shape in which the length in the circumferential direction is relatively longer than the length in the radial direction. A propeller shaft characterized by:

7. 3. The propeller shaft according to claim 2, The slit portion has an opening portion that opens in the radial direction. A propeller shaft characterized by:

8. A propeller shaft according to claim 7, In a cross section viewed from the axial direction, the maximum width dimension of the spacer member is set to be larger than the width dimension of the opening. A propeller shaft characterized by:

9. A propeller shaft according to claim 7, The slit portion is widened in a stepped manner relative to the opening portion, In a cross section viewed from the axial direction, a maximum distance between one circumferential end of the opening and one circumferential end of the slit portion farther from the one circumferential end of the opening is greater than a dimension of the spacer member in the circumferential direction. A propeller shaft characterized by:

10. A propeller shaft according to claim 7, A notch is provided at each of the base portions of the plurality of protrusions. A propeller shaft characterized by:

11. 3. The propeller shaft according to claim 2, The notch portion is formed in a tapered shape such that the width dimension in the circumferential direction increases toward the outside in the radial direction. A propeller shaft characterized by:

12. A boot protection member for a propeller shaft, which protects a boot member used in a propeller shaft in which a first rotating member and a second rotating member are connected via a constant velocity joint, and is detachable from the first rotating member, The constant velocity joint is an inner ring member connected to the first rotary member; an outer ring member connected to the second rotating member and to which rotation of the inner ring member is transmitted via rolling elements arranged on the outer peripheral side of the inner ring member, The boot member is a first cover portion having a first end portion extending in a direction approaching the first rotating member in an axial direction along the rotation axis of the first rotating member and a second end portion fixed to an outer circumferential side of the outer ring member; a second cover portion having a first end folded back from the first cover portion and disposed on the inner peripheral side of the outer ring member, and a second end fixed to the first rotating member; and The boot protection member includes: a cylindrical portion surrounding an outer periphery of the first rotary member; an insertion portion provided in the cylindrical portion between the first cover portion and the second cover portion; a plurality of protrusions provided so as to protrude toward an outer circumferential side of the cylindrical portion in a radial direction perpendicular to the rotation axis; a notch provided on the cylindrical portion on a side opposite to the plurality of protrusions across the rotation axis; a slit portion provided between the plurality of protruding portions in the circumferential direction of the rotation axis and penetrating in the axial direction, A boot protection member for a propeller shaft.

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