WO2007102559A1

WO2007102559A1 - Mounting structure for boot for constant velocity universal joint

Info

Publication number: WO2007102559A1
Application number: PCT/JP2007/054479
Authority: WO
Inventors: Tadashi Suzuki; Shuji Mochinaga; Yasunori Kawasaki; Masaru Murayama
Original assignee: Ntn Corporation
Priority date: 2006-03-08
Filing date: 2007-03-07
Publication date: 2007-09-13

Abstract

A mounting structure for a boot for a constant velocity universal joint, where a reduction in sealing ability of the boot is minimized even if it is used in a high-temperature environment, so that stable the sealing ability is maintained for a long period. Two circumferential ridges (23, 24) are formed on a boot mounting part (22) of a shaft (9) of the constant velocity universal joint. A groove (20) is formed between the circumferential ridges (23, 24), and a ring-shaped seal member (30) having a smaller permanent compression strain amount than the material of the boot is interposed between the groove (20) and the bore surface of a small diameter part (11) of the boot (1).

Description

Specification

Mounting structure for constant velocity universal joint boots

Technical field

[0001] The present invention relates to a shaft connected to an inner joint member of a constant velocity self-joint incorporated in, for example, a power transmission mechanism of an automobile or various industrial machines, and a constant velocity that ensures the sealing performance of the constant velocity universal joint. The present invention relates to a mounting structure with a universal joint boot.

Background art

[0002] For example, in a constant velocity universal joint incorporated in a power transmission mechanism of an automobile or various industrial machines, a bellows shape is used to prevent foreign matter such as dust from entering the joint and leakage of grease sealed in the joint. A constant velocity universal joint boot is mounted.

As shown in FIG. 6, for example, this type of boot 101 includes a large-diameter portion 110 fixed to the outer ring 104 of the constant velocity universal joint 102, and a small-diameter portion 111 fixed to a shaft 109 extending from the inner ring 106. In addition, a bellows portion 114 in which valley portions 113 and peak portions 112 are alternately formed between the large diameter portion 110 and the small diameter portion 111 is provided. The boot 101 is attached by fastening the large-diameter portion 110 and the small-diameter portion 111 to the outer ring 104 and the shaft 109 with a band 118.

[0004] On the outer peripheral surfaces of the large-diameter portion 110 and the small-diameter portion 111 of the boot 101, concave grooves 117 are provided, and a tightening band 118 is fitted in each concave groove 117. On the other hand, the groove mounting portion 122 of the shaft 109 is provided with a concave groove 120 and annular protrusions 123 and 124 on both axial sides of the concave groove 120. The boot 101 is generally formed of a resin material. Among the fixing portions (the large diameter portion 110 and the small diameter portion 111), the small diameter portion 111 particularly tightens the tightening band 118 and the annular protrusions 123 and 124 provided on the shaft 109. It is designed to ensure sealability by biting into the inner surface.

(See Figure 7).

[0005] As rubber boots, there are thermoplastic elastomer boots that exhibit superior properties such as moldability, fatigue resistance, wear resistance, and high-speed rotation (running performance during rotation) compared to rubber boots. There is a tendency to be frequently used in recent years. However, a thermoplastic elastomer boot has a large compression set compared to a rubber boot, and the repulsive force tends to decrease. Therefore, the sealing performance tends to decrease due to a change with time.

[0006] In particular, the deterioration of the sealing performance of the boot 101, in which this tendency is remarkable, is accelerated under a high temperature environment (high temperature atmosphere) on the differential gear side (inboard side). For this reason, it is difficult for a conventional seal structure to exhibit a stable sealing function for a long time, and grease leakage may occur between the boot 101 and the shaft 109 due to a decrease in sealing performance.

[0007] As a means for suppressing such deterioration in sealing performance, as shown in FIG. 7, a ring-shaped sealing member (for example, O-ring) is provided between the boot mounting portion 122 of the shaft 109 and the small diameter portion 111 of the boot 101. A configuration in which 130 is interposed is known (for example, see Patent Document 1).

Patent Document 1: Japanese Utility Model Publication No. 4 128536

Disclosure of the invention

Problems to be solved by the invention

[0008] The configuration of Patent Document 1 described above is, for example, by fitting and fixing the small diameter portion 111 of the boot 101 to the boot mounting portion 122 after the seal member 130 is mounted in the concave groove 120 of the shaft 109. The small-diameter portion 111 of the boot 101 needs to get over the seal member 130 when fitting externally. By the way, the sealing member 130 including the O-ring exhibits a sealing function only after giving a predetermined crushing allowance. Therefore, in terms of improving the sealing performance, it is necessary to use the sealing member 130 whose outer diameter is larger than the inner diameter of the small diameter portion 111 of the boot 101. However, in this configuration, when the boot 101 is fitted on the boot mounting portion 122, the boot 101 and the seal member 130 may interfere with each other, and the seal member 130 may be twisted or the seal member 130 may be damaged. .

[0009] If the seal member 130 is twisted or damaged, there is a possibility that a desired effect of suppressing a decrease in sealability cannot be obtained. As an example of a means for avoiding a forceful situation, it is conceivable to make the inner diameter dimension of the small diameter portion 111 of the boot 101, particularly the opening end side thereof, larger than the outer diameter dimension of the seal member 130. However, in this case, the rigidity of the resin boot 101 is set to be relatively high, so that even if the small-diameter portion 111 is tightened with the tightening band 118, the small-diameter portion 111 is opened. The mouth end side does not sufficiently adhere to the shaft 109, and it becomes difficult to ensure sealing performance.

[0010] The present invention has been made in view of the above-described problems, and the object of the present invention is to avoid a decrease in sealing performance due to twisting or damage of the seal member when the boot is mounted. It is an object of providing a mounting structure for a constant-speed boot that can secure a stable sealing performance over a long period of time.

Means for solving the problem

[0011] As a technical means for achieving the above-mentioned object, the present invention includes a shaft that extends the inner joint member force of a constant velocity universal joint, and a boot for a constant velocity universal joint that is fixed to the shaft by a fastening band. Provided with two circumferential projections on the boot mounting portion of the shaft, and between the concave groove between the circumferential projections and the shaft fixing portion of the boot, the amount of compression set is smaller than that of the boot material. A ring-shaped seal member is interposed.

[0012] In the present invention, a ring-shaped seal member is interposed between the concave groove of the boot mounting portion of the shaft and the shaft fixing portion of the boot. Even if the sealing performance of the boot decreases, the sealing member supplements the decrease in the sealing performance of the boot and suppresses the deterioration of the sealing performance.

[0013] In addition, since this seal member is made of a material having a compression set smaller than that of the boot material, the boot has a repulsive force reduced due to the compression set, and sealability cannot be obtained. Even in the state, the sealing member secures the sealing performance instead of the boot.

[0014] The seal member according to the present invention has an amount of compression set smaller than that of the boot material, and it is optimal to use an O-ring made of the material.

[0015] Two or more seal members can be disposed. If a plurality of seal members are arranged in this manner, it is further ensured that the deterioration of the sealability due to the change of the boot over time is suppressed.

[0016] Further, it is desirable that the seal member has a cross-sectional shape that matches the shaft fixing portion of the boot and the groove of the shaft. In this way, the sealing function of the sealing member can be ensured.

[0017] The seal member exhibits an elastic restoring force under the temperature of the boot mounting portion during joint operation. It is desirable that the ring-shaped sealing member has.

[0018] Under a high temperature environment when the joint is operated, due to a decrease in elastic restoring force (repulsive force) due to compression set of the boot, a predetermined sealing property cannot be obtained between the boot and the shaft. Even in the state, the sealing member secures the sealing performance instead of the boot. Since this seal member has elastic restoring force even under the temperature of the boot mounting part when the joint is operated, that is, in a high temperature environment, deterioration of the seal member due to the heat effect is surely prevented, and the deterioration of the sealing performance is more reliably achieved. Can be suppressed.

[0019] It is desirable that the sealing member be interposed in a state where the crushing rate σ is 25% ≤σ≤60%. The crushing ratio σ is the ratio of the crushing margin Δ to the initial thickness t (= A Zt).

[0020] If the crushing rate of the seal member is smaller than 25%, the seal member cannot be provided with a predetermined crushing amount as the sealing performance of the boot is lowered. As a result, the seal member is provided. However, sufficient sealability cannot be ensured. On the other hand, if the crushing rate of the sealing member is greater than 60%, the sealing performance cannot be ensured due to compression cracking of the sealing member.

[0021] Another feature of the present invention is that the outer diameter dimension of the boundary portion that divides the recessed portion from the outer peripheral surface of the shaft is accommodated and disposed in the recessed portion, located on both sides in the axial direction of the recessed portion in the boot mounting portion of the shaft. It is set to be larger than the outer diameter of the seal member before fixing the fastening band

[0022] By adopting a powerful configuration, when the small diameter portion of the boot is externally fitted to the boot mounting portion of the shaft, the small diameter portion of the boot, in particular, the inner diameter surface on the opening end side thereof is prevented from interfering with the seal member. It is possible to prevent damage to the seal member due to interference between the two. Therefore, it is possible to reliably enjoy the effect of suppressing the deterioration of the sealing performance by providing the seal member.

[0023] In the above configuration, an annular protrusion can be provided at a boundary portion that divides the recess from the outer peripheral surface of the shaft. By providing a strong annular protrusion, when the outer periphery of the small-diameter portion of the boot is tightened with a fastening band, the annular protrusion can be caused to bite into the inner diameter surface of the small-diameter portion of the boot. Thereby, the further sealing performance improvement can be aimed at. The boundary portion may have an outer diameter that coincides with the outer peripheral surface of the shaft.

[0024] A portion of the inner diameter surface of the small diameter portion of the boot that is opposed to the concave portion of the shaft during fixing has a small diameter. It is desirable to provide a convex portion protruding toward the inner diameter side from the opening end portion of the portion. This is because a predetermined crushing allowance is given to the sealing member, and the effect of suppressing the deterioration of the sealing performance by arranging the sealing member is surely obtained.

The invention's effect

[0025] According to the present invention, the ring-shaped seal member having a smaller amount of compression set than the boot material is interposed between the groove between the circumferential protrusions of the shaft and the shaft fixing portion of the boot. Even if the sealability of the boot decreases due to changes over time due to the influence of heat, the seal member can compensate for the decrease in the sealability of the boot and suppress the decrease in the sealability.

[0026] In addition, since this seal member is made of a material having a compression set smaller than that of the boot material, the boot has a repulsive force reduced due to the compression set, and sealability cannot be obtained. Even in the state, the sealing member can secure the sealing performance instead of the boot. As a result, even when used in a high temperature environment, it is possible to suppress a decrease in sealing performance and to exhibit a stable sealing function over a long period of time.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a constant velocity universal joint 2 and a constant velocity universal joint boot 1 adopting the mounting structure of the embodiment of the present invention.

[0028] The constant velocity universal joint 2 includes an outer ring 4 as an outer joint member in which a plurality of track grooves 3 are formed in the axial direction on the inner peripheral surface, and an inner joint member in which a plurality of track grooves 5 are formed on the outer peripheral surface. A plurality of balls 7 arranged in a ball track formed by cooperation of the inner ring 6, the track groove 3 of the outer ring 4 and the track groove 5 of the inner ring 6, and a pocket 8a for accommodating the balls 7. The main part is composed of cage 8 that we have. Further, the shaft 9 is connected to the inner periphery of the inner ring 6 via a torque transmission means such as a selection or a spline.

[0029] It should be noted that the constant velocity universal joint 2 is only required to be able to mount the boot 1, so there is a fixed type constant velocity universal joint! / Is a sliding type constant velocity universal joint! / It may be a gap.

[0030] The boot 1 is formed of, for example, a thermoplastic elastomer such as ester, olefin, urethane, amide, or styrene. Thermoplastic elastomer is between resin and rubber Has the nature of Although the thermoplastic elastomer is an elastic body, it can be processed by an ordinary molding machine for thermoplastic resin.

[0031] The boot 1 is attached to a large diameter portion 10 as an outer ring fixing portion attached to an opening end portion of the outer ring 4 of the constant velocity universal joint 2, and a shaft 9 connected to the inner ring 6 of the constant velocity universal joint 2. A small-diameter portion 11 as a shaft fixing portion, and a bellows portion 14 having a ridge portion 12 and a valley portion 13 alternately arranged along the axial direction between the large-diameter portion 10 and the small-diameter portion 11 Is provided. The mountain part 12 and the valley part 13 are connected by an inclined part 15.

A boot mounting portion 16 that also has a circumferential notch force is provided on the outer peripheral surface on the opening side of the outer ring 4, and the large-diameter portion 10 is externally fitted to the boot mounting portion 16. The large-diameter portion 10 is fixed to the outer ring 4 by fastening the fastening band 18 in the fitting groove 17 formed on the outer peripheral surface of the large-diameter portion 10.

[0033] As shown in FIGS. 1 and 2, the shaft 9 is provided with a boot mounting portion 22 having a boot mounting concave groove 20 along the circumferential direction at a position protruding from the outer ring 4 by a predetermined amount. The part 11 is fitted on the boot mounting part 22. The small-diameter portion 11 is fixed to the shaft 9 by fastening the fastening band 18 in the fitting groove 17 formed on the outer peripheral surface of the small-diameter portion 11.

[0034] The boot mounting portion 22 is provided with a concave groove 20 on the outer diameter surface of the shaft, and two circumferential protrusions 23 and 24 are provided at the opening end (axial end) of the concave groove 20. Yes. The circumferential protrusions 23 and 24 have the same outer diameter and are set to be larger than the outer diameter of the boot mounting portion 22.

The small diameter portion 11 of the boot 1 is attached to the boot attachment portion 22 of the shaft 9 via the seal member 30. That is, a ring-shaped seal member 30 having a compression set smaller than that of the boot material between the concave groove 20 positioned between the circumferential protrusions 23 and 24 of the shaft 9 and the inner diameter surface of the small diameter portion 11 of the boot 1. Intervene.

[0036] The seal member 30 is most preferably an O-ring that has a material force with a smaller amount of compression set than the boot material. Here, the boot 1 is made of a thermoplastic elastomer that has excellent durability such as fatigue and wear resistance, heat aging resistance, oil resistance, and high-speed rotation (running performance during rotation) and exhibits stable functions. There is one. The material of the seal member 30 is CR, NBR, silicon, which has a smaller amount of compression set than the thermoplastic elastomer, which is a boot material. Of these, fluorine rubber or the like is preferable. Other boot materials may be rubber materials such as chloroprene.

[0037] As described above, the ring-shaped sealing member 30 is interposed between the concave groove 20 of the boot mounting portion 22 of the shaft 9 and the inner diameter surface of the small-diameter portion 11 of the boot 1, thereby being affected by heat and the like. Therefore, even if the sealing performance of the boot 1 is lowered due to a change with time, the sealing member 30 can supplement the sealing performance of the boot 1 and suppress the degradation of the sealing performance.

[0038] In addition, since the seal member 30 has a material force having a smaller amount of permanent compression than the thermoplastic elastomer that is the boot material, the repulsive force of the boot 1 is reduced due to the compression set and the sealing property is reduced. The seal member 30 secures the sealing performance in place of the boot 1 even in a state where it is no longer possible to obtain the seal.

[0039] The seal member 30 is a ring-shaped member such as an O-ring, and the cross-sectional shape thereof can be various, such as a circle, an ellipse, and a square as shown in FIGS. 3 (a) to 3 (c). On the other hand, the inner diameter surface of the small-diameter portion 11 of the boot 1 is also provided with a circumferential protrusion other than a flat one, and the concave groove 20 of the shaft 9 is also semicircular, triangular, There are various types such as trapezoidal shape and rectangular shape. Therefore, the cross-sectional shape of the seal member 30 may be a cross-sectional shape that matches the inner diameter surface of the small-diameter portion 11 of the boot 1 and the concave groove 20 of the shaft 9. In this way, the sealing function of the sealing member 30 can be ensured.

[0040] It is desirable that the material of the seal member 30 has an elastic restoring force even at the temperature of the boot mounting portion 22 when the joint is operated. The temperature of the boot attachment 22 during joint operation rises to about 130 ° C. As a material of the seal member 30 that can maintain elastic restoring force without causing sag even in such a high temperature environment, acrylic rubber (ACM), hydrogenated- Trinole rubber (HNBR), ethylene propylene rubber (EPDM), silicon rubber (VMQ, FVMQ, etc.), or fluoro rubber (FKM, FFKM, FEPM, etc.) are suitable. Of course, the sealing member 30 is not limited to this type of rubber material, but may be formed of other resin materials that satisfy the above conditions.

[0041] As described above, the ring-shaped seal member 30 is interposed between the groove 20 of the boot mounting portion 22 of the shaft 9 and the inner diameter surface of the small diameter portion 11 of the boot 1, thereby allowing the time-dependent effect due to the influence of heat or the like. Strange Even if the sealing performance of the boot 1 is reduced due to the seal, the sealing member 30 can compensate for the sealing performance of the boot 1 and suppress the deterioration of the sealing performance.

[0042] Further, the seal member 30 has a material force having a smaller amount of permanent deformation than the thermoplastic elastomer that is a boot material. Therefore, when the seal member 30 is exposed to a particularly high temperature environment, Even when the elastic restoring force (repulsive force) due to the compression set is reduced and the predetermined sealability between the boot 1 and the shaft 9 cannot be obtained, the seal member 30 has the predetermined sealability instead of the boot 1. Secure. Further, since the seal member 30 has the inertia restoring force even under the temperature of the boot mounting portion 22 when the joint is operated, that is, the high temperature environment of about 130 ° C. described above, the seal member 30 due to the heat effect is provided. The deterioration of the sealing property can be reliably prevented, and the deterioration of the sealing performance can be more reliably suppressed.

[0043] The seal member (O-ring) 30 can ensure sealing performance only when it is used in a state where it is crushed by a predetermined amount. Although it depends on the material and size, it is generally recommended that the seal member be used in a crushing ratio of 10 to 25% from the viewpoint of securing sealability and preventing compression cracking. However, as described above, since the repulsive force of the boot 1 serving as the tightening portion of the seal member 30 decreases due to the compression set in a high temperature environment, the seal member 30 is crushed in the above range. It has been found by the present inventors that even when used, it may be difficult to ensure sufficient crushing allowance, that is, sealability.

[0044] Therefore, as a result of intensive studies, the inventors of the present application have found that the sealability can be reliably ensured if the seal member 30 is used in a state where the crushing rate σ is 25% ≤ σ ≤ 60%. . The reason is based on the confirmation test results shown below. Two types of confirmation tests were conducted. In the first test, the small-diameter portion 11 of the boot 1 was fixed to the boot mounting portion 22 (concave groove 20) of the shaft 9 with the seal member 30 disposed at an arbitrary crushing ratio, and the constant velocity universal joint 2 Rotate the to raise the temperature of the boot mounting part 22 to 130 ° C, then cool it down to room temperature, and check the amount of reduction in the crushing rate σ of the seal member 30 in that state, and whether there is any grease leakage It is. On the other hand, in the second test, when the sealing member 30 is kept at a predetermined crushing rate σ and placed in a high-temperature bath at 130 ° C. and held for 72 hours, the crushing rate σ at which compression cracking occurs in the sealing member 30 is as follows. The upper limit value is confirmed.

[0045] First, in the first test, the crushing rate σ of the seal member 30 is set to two types of 40% and 60%. The above items were confirmed. The crushing rate σ of the sealing member 30 after cooling decreased by about 14 to 21% regardless of the crushing rate σ. This is because the boot 1 is deteriorated by being exposed to a high temperature of 130 ° C., the contact portion of the boot 1 with the seal member 30 is deformed, and the seal member 30 is deformed along this (crushing). This is probably due to a decrease in bills. As a result, it was confirmed that when the seal member 30 having a crushing rate σ = 20% was used, the crushing rate σ 0% of the seal member 30 after cooling was reached, and grease leakage may occur. It was.

[0046] Next, in the second test, the crushing rate σ of the seal member 30 was increased stepwise, and compression cracks occurred when using the seal member 30 with the crushing rate σ = 65%. It was confirmed that the upper limit of the crush rate σ of 30 must be 60% or less.

[0047] From the above test results, it can be confirmed that the crushing ratio σ of the seal member 30 is preferably set to 25% ≤ σ ≤ 60%.

[0048] As shown in FIG. 4 (a), the sealing member 30 has an outer diameter dimension Φ repulsive force before tightening of the tightening band 18 smaller than an outer diameter dimension φ A of the annular projections 23 and 24. Things can be used. In other words, the outer diameter dimension φA of the annular protrusions 23 and 24 can be set larger than the outer diameter dimension φB of the seal member 30 before the fastening band 18 is fastened.

[0049] The boot 1, the seal member 30, and the shaft 9 having the above-described configuration are assembled in the following procedure. First, the seal member 30 is externally fitted into the recess 20 provided in the boot attachment portion 22 of the shaft 9, and then the small-diameter portion 11 of the boot 1 is externally fitted to the boot attachment portion 22 as shown in FIG. To do. At this time, the small-diameter portion 11 of the boot 1, more precisely the opening end portion of the small-diameter portion 11, will overcome the seal member 30 in consideration of securing the sealing performance by the seal member 30. Diameter dimension φ B force If the outer diameter dimension of the annular projections 23, 24 is set larger than φ A (Φ Β> φ Α), the small diameter part 11 of the boot 1 and the seal member 30 interfere with each other, and the seal member 30 May be twisted or damaged. In the case where force is applied, there is a possibility that the effect of suppressing deterioration in sealing performance due to the provision of the seal member 30 cannot be obtained.

[0050] As an example of means for avoiding interference between the small-diameter portion 11 of the boot 1 and the seal member 30, the inner diameter dimension of the small-diameter portion 11 of the boot 1, particularly the opening end side thereof, is determined from the outer diameter dimension of the seal member 30. However, the rigidity of the greaves boot 1 is set to be relatively high. Therefore, even if it is tightened with the tightening band 18, the opening end side of the small diameter portion 11 does not sufficiently adhere to the shaft 9, and it is difficult to ensure a sealing property.

Therefore, in the present invention, as described above, the outer diameter dimension φ A of the annular projections 23 and 24 that define the recess 20 serving as the accommodating portion of the seal member 30 is set to the outer diameter of the seal member 30 before the fastening band 18 is fixed. The diameter was set larger than Φ （(φ Α> φ Β). As a result, the small-diameter portion 11 of the boot 1 that does not cause twisting or damage of the seal member 30 as described above can be externally fitted to the boot mounting portion 22 of the shaft 9, and the sealing performance by providing the seal member 30 It is possible to reliably enjoy the effect of suppressing the decline.

Then, as shown in FIG. 2, the small-diameter portion 11 of the boot 1 is fixed to the shaft 9 by tightening the tightening band 18 in the fitting groove 17 provided on the outer peripheral surface of the small-diameter portion of the boot 1. Is done. At this time, in the present embodiment, the annular protrusions 23 and 24 are provided in the partitioning portion that divides the recess 20 from the outer peripheral surface of the shaft 9, so that when the fastening band 18 is fastened, the small-diameter portion 11 of the boot 1 is attached. Since the annular protrusions 23 and 24 bite in, the sealing performance of the boot 1 is enhanced.

[0053] It should be noted that the crushing margin to be imparted to the seal member 30 is the shaft of the inner diameter surface of the small diameter portion of the boot 1 in order to reliably obtain the effect of suppressing the deterioration of the sealing performance due to the arrangement of the seal member 30. It can be applied by a convex portion 19 provided at a portion facing the concave portion 20 of the nine. The convex portion 19 is formed with a smooth curved surface that does not need to get over the seal member 30! /. Therefore, there is no possibility of the seal member 30 being twisted or damaged during insertion.

FIG. 5 is an enlarged view of a main part of another embodiment of the constant velocity universal joint 2 and the constant velocity universal joint boot 1 adopting an attachment structure that is effective in the present invention. In this embodiment, as shown in FIG. 5 (a), the boundary portion provided at both axial ends of the recess 20 and defining the recess 20 from the outer peripheral surface of the shaft 9 coincides with the outer peripheral surface of the shaft 9. . In this case, the outer diameter dimension φ A ′ of the boundary portion that divides the recess 20 from the outer peripheral surface of the shaft 9 is set larger than the outer diameter dimension φ 寸法 ′ of the seal member 30 before the fastening band 18 is fixed. Therefore, as shown in Fig. 5 (b), interference between the two small-diameter portions 11 of the boot 1 and the boot fixing portion 22 of the shaft 9 is avoided as in the case of Fig. 4 (b). It becomes possible.

In the above embodiment, the case where one seal member 30 is interposed has been described. However, the present invention is not limited to this, and two or more seal members 30 are provided. The number may be arbitrary. If a plurality of seal members 30 are arranged in this manner, it is even more reliable to suppress a decrease in sealability due to the aging of the boot 1.

[0056] A comparative test was conducted to demonstrate the usefulness of the present invention. The test member (shaft 9) is prepared with and without the seal member 30 disposed in the recessed groove 20, and in the latter case, made of nitrile rubber (NBR), fluoro rubber (FKM) Two types of seal members 30 made by the manufacturer were used. In the test, the small diameter part 11 of the boot 1 is fixed to the boot attaching part 22 of each shaft 9 and the constant velocity universal joint 2 is rotated at an angle so that the temperature of the boot attaching part 22 is 120 ° C. After raising the temperature to 130 ° C, it is cooled to room temperature, and in that state, it is checked whether there is any grease leakage.

[0057] (1) When the temperature of the boot mounting part 22 is raised to 120 ° C

In all cases where the seal member 30 was provided, grease leakage did not occur, whereas in the case where the seal member 30 was not applied, grease leakage occurred.

[0058] (2) When the temperature of the boot attachment 22 is raised to 130 ° C

When the seal member 30 made of nitrile rubber (NBR) was used, grease leakage occurred, whereas when the seal member 30 made of fluoro rubber (FKM) was used, grease leakage did not occur and the force was generated.

[0059] The usefulness of the present invention can be confirmed from the above test results.

[0060] The power described in the embodiment of the present invention has been described above. The present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the gist of the present invention. Of course, it can be done. The scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings recited in the claims and all modifications within the scope.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a state in which a boot is mounted on a constant velocity universal joint in an embodiment of the present invention.

2 is an enlarged cross-sectional view of the main part of FIG.

FIG. 3 is a sectional view of a sealing member, where (a) is a circle, (b) is an ellipse, and (c) is a sectional view showing a rectangle. FIG. 4 (a) is an enlarged cross-sectional view of the main part of the shaft before attaching the boot, and FIG. 4 (b) is an enlarged cross-sectional view of the main part showing a state where the boot is attached to the shaft.

[FIG. 5] (a) is an enlarged cross-sectional view of the main part of the shaft before attaching the boot according to another embodiment, and (b) is a state in which the boot is attached to the shaft in the configuration shown in (a). It is a principal part expanded sectional view shown.

6] A sectional view showing a state in which the boot is mounted on the constant velocity universal joint in a conventional example of the structure for mounting the boot for the constant velocity universal joint.

7] FIG. 7 is an enlarged cross-sectional view of the main part of FIG.

Claims

The scope of the claims

[1] An inner joint member force of the constant velocity universal joint includes an extending shaft, and a constant velocity universal joint boot fixed to the shaft by a tightening band. Two boots in the circumferential direction are provided on the boot mounting portion of the shaft. It is provided with a ring-shaped seal member with a smaller compression set than the boot material between the groove between the circumferential projections and the shaft fixing part of the boot. Mounting structure for joint boots.

[2] The boot structure for a constant velocity universal joint according to claim 1, wherein the seal member is an O-ring.

[3] The boot mounting structure for a constant velocity universal joint according to claim 1, wherein two or more seal members are provided!

4. The mounting structure for a constant velocity universal joint boot according to claim 1, wherein the seal member has a cross-sectional shape adapted to a shaft fixing portion of the boot and a groove in the shaft.

[5] The mounting of the boot for a constant velocity universal joint according to claim 1, wherein the sealing member is a ring-shaped sealing member having an elastic restoring force under the temperature of the boot mounting portion during joint operation. Construction.

6. The mounting structure for a constant velocity universal joint boot according to claim 1, wherein the seal member is interposed in a state where a crush rate σ is 25% ≤σ≤60%.

[7] An inner joint member force of the constant velocity universal joint includes a shaft extending, and a constant velocity universal joint boot fixed to the shaft by a fastening band, and an annular recess is provided in the boot mounting portion of the shaft. With the mounting structure of the constant velocity universal joint boot in which the seal member is interposed between the concave portion and the shaft fixing portion of the boot,

The seal member before fixing the fastening band, which is located on both axial sides of the recess in the boot mounting portion and accommodates and arranges the outer diameter dimension of the boundary portion that divides the recess from the outer peripheral surface of the shaft. Mounting structure of boule for constant velocity universal joint, characterized in that it is set larger than the outer diameter of

8. The mounting structure for a constant velocity universal joint boot according to claim 7, wherein an annular protrusion is provided at the boundary portion.

[9] The constant velocity universal joint according to claim 7, wherein the boundary portion coincides with an outer peripheral surface of the shaft. Mounting structure for hand boots.