JPH0336738Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in an elastic joint that flexibly connects a driving shaft and a driven shaft to smoothly transmit rotational force.

(Prior Art) FIGS. 1 and 2 show a conventional elastic joint 1,
A plurality of cylindrical bushes 3 with flanges on both ends are planted symmetrically with respect to the center of a rubber disk 2 with a hollowed out center, and fiber cords of rayon, polyester, etc. are bundled into a square cross-sectional shape and made into a loop shape. The formed restraining member 4 is placed at an intermediate position between the flange portions 3a of the cylindrical bushing 3 at an upper and lower position so that their side surfaces touch each other so as to restrain a pair of adjacent two members of the cylindrical bushing 3, respectively. They are buried in alternating layers.

Therefore, when connecting a driving shaft and a driven shaft using such an elastic joint 1, hook-shaped arms are protruded from every other cylindrical bush 3 of the rubber substantially disc 2 at corresponding positions. Attach a flange to each shaft, alternately arrange the arms on the driving shaft side and the driven shaft side with respect to every other cylindrical bushing 3, insert bolts into the flange arms and the cylindrical bushing 3, and insert the bolts into the cylindrical bushing 3. A nut is tightened at the flange portion 3a of the bush 3 to connect the drive shaft and the driven shaft.

In an elastic joint with such a structure, the restraining member bears most of the rotational torque, and therefore, the restraining member has a high tensile strength and has sufficient durability against repeated expansion and contraction. It must be something that you have.

(Problems to be Solved by the Invention) However, such conventional elastic joints have the following drawbacks.

That is, in the conventional elastic joint, there is nothing in the middle of the cylindrical bushing to prevent the axial movement of the upper restraining member and the lower restraining member.
During manufacturing, when rubber is injected or compressed and pressure vulcanized, the binding members bundled into rectangular cross-sections become disordered, and the bundles unravel, causing the fiber cords near the sides of the upper and lower binding members to become embedded in each other. It often happens that the bundles are buried in such a way that the bundles are disorganized and the binding members that are tied over the bundles are buried with uneven density. As a result, when an elastic joint manufactured under such conditions is actually used, the spring constant decreases early, and when repeated rotational torque is applied, the displacement gradually increases and the tension applied to the restraining member increases. Therefore, if there is a sparse density in the restraining member as described above, breakage of the fiber cords will occur, especially in the sparse portions, and eventually the entire restraining member will break, and it may not have sufficient durability. There isn't.

In addition, the above explanation has addressed problems caused by manufacturing, but even if the restraining member is buried without being disturbed during manufacturing, creep will occur in the fiber cord when this elastic joint is used in a high temperature atmosphere. For example, when used as an elastic joint for an automobile's propeller shaft, the elastic joint is bent against the drive shaft and used, so the restraint member rotates between the cylindrical bushings. Therefore, if the restraint member is loosened as described above, the restraint member strung above and below between the cylindrical bushes will bend in the axial direction Since they shift and become wedged into each other, as described above, the spring constant decreases prematurely, leading to a decrease in durability.

The present invention was devised in view of the above circumstances, and provides an elastic joint that flexibly connects a driving shaft and a driven shaft, transmits rotational force smoothly, and has excellent durability. The purpose is to

(Means for solving the problem) The present invention is based on a roughly rubber disk with a hollowed out center.
There are a plurality of cylindrical bushes with flanges on both ends symmetrically with respect to the center, and a restraining member, which is a bundle of fiber cords formed in a loop shape and having a rectangular cross section, is attached to two adjacent cylindrical bushes of the pair of cylindrical bushes. In an elastic joint that is alternately strung up and down so as to restrain the members, the cylindrical bushing is further provided with an intermediate flange at an intermediate position in the axial direction, and the fiber cord constituting the restraining member is impregnated with rubber glue. The restraining member is vertically separated and arranged between both end flanges and an intermediate flange provided on the cylindrical bushing, and further,
On the side where the pieces are not hung by the restraint member, a deep recess is formed along the restraint member from the inner and outer peripheral surfaces of the rubber approximately disk and the tips of the pair of two adjacent cylindrical bushes. The gist is an elastic joint in which the rubber is coated and the thickness of the coated rubber in the axial center direction of the cylindrical bushing from the bottom of the recess to the restraint member is approximately equal.

(Example) The present invention will be described in detail below based on the drawings.

FIGS. 3 to 4 show an embodiment of the elastic joint 10 of the present invention, in which a roughly circular disk 2 made of rubber is hollowed out in the center.
A cylindrical bushing 30 having a plurality of both ends and intermediate flanges 30a is implanted symmetrically with respect to the center of the cylindrical bushing 30, and the space between the cylindrical bushings 30, 30 is made of rayon or polyester impregnated with unvulcanized rubber glue. , a restraining member 40 formed into a loop by bundling fiber cords such as aromatic polyamide into a rectangular cross-sectional shape.
However, each flange 3 is arranged so as to restrain a pair of adjacent cylindrical bushes 30, 30, respectively.
It is vulcanized and buried in the rubber substantially disk 20, extending alternately upward and downward between 0a and 30a. That is, the restraint member 40 is attached to the intermediate flange 3 of the cylindrical bush 30.
The upper and lower sides are separated and spanned by 0a, and are housed and buried between the respective flanges 30a, 30a.

In addition, the side of the cylindrical bush 30 that is not spanned by a pair of adjacent restraint members 40 is a substantially rubber disk 2.
Rubber is coated so as to form a deep recess 50 along the restraining member 40 from the inner and outer peripheral surfaces and the tips of a pair of two adjacent cylindrical bushes 30, and from the bottom of the recess to the restraining member 40. The coating rubber thickness t in the axial center direction of the cylindrical bushing 30 is approximately equal.

Furthermore, as shown in FIG.
0 has an arcuate shape along the restraining member 40 of the cylindrical bush 30 and moving away from the restraining member 40 up to the inner and outer peripheral surfaces of the rubber substantially disk 20.

Here, θ is two adjacent cylindrical bushes 30
and a deep recess 50 formed along the restraining member 40.
The angle between the opposing sides of the tangential line connecting the center of the rubber disk 20, l is the angle between the opposing sides of the deep recess 50 formed along the two adjacent cylindrical bushes 30 and the restraining member 40. The shortest distance, t, is the coating rubber thickness in the axial center direction of the cylindrical bushing 30 from the bottom of the recess to the restraint member 40.

With the elastic joint of the present invention configured as described above, it is possible not only to bury the restraining members sparsely and densely during manufacturing, or to embed the upper and lower restraining members into each other, but also to prevent the problem during use. Even if creep occurs in the fiber cord and the restraint member becomes somewhat loose, the intermediate flange can restrain the movement of the restraint member in the axial direction.
No disturbance of the restraining member occurs. Therefore, it is possible to prevent the spring constant from decreasing not only initially but also over a long period of time.
Even when repeated rotational constant torque is applied, almost constant displacement can be maintained, so excessive tension is not applied to the restraint member, fatigue of the restraint member is reduced, and there is no possibility of breakage, resulting in increased durability as an elastic joint. is significantly improved.

The restraining member is formed by bundling fiber cords impregnated and coated with unvulcanized rubber glue into a loop shape with a rectangular cross section and vulcanized and buried, so there is no wear and tear due to contact between the cords.

On the other hand, according to the elastic joint of the present invention, even if the same material (rubber) is used, the torsional spring constant, prying moment, and axial spring constant are smaller than those of the conventional joint, and a large torsional torque can be applied. Even if the cylindrical bushes 30 are moved closer together, there are deep recesses between every other cylindrical bushings 30 and alternately on the driving and driven parts, so even if the cylindrical bushings 30 approach, the rubber will not fill up. Instead, θ and l become smaller, and eventually the opposing sides of the deep recess 50 come into contact, and the rubber members exert a stopper effect, resulting in greater nonlinear characteristics than before.
There is no damage to the rubber, the load on the restraint member 40 is reduced, and durability is improved.

Furthermore, compared to conventional structures, the prying moment is smaller at a certain prying angle, reducing the burden on the rubber and restraint members and improving durability. Furthermore, it is highly flexible because a large prying angle can be achieved with a constant prying moment.

Next, in order to specifically demonstrate the effects of the elastic joint of the present invention, the results of a bench durability test will be described.

The test piece was one in which the cylindrical bush implanted in the elastic joint had an intermediate flange (see Figures 3 and 4).
A high-temperature torsional durability test was conducted under the following conditions using the example of the present invention shown in the figure and the comparative example shown in Figs. 1 and 2 that did not have an intermediate flange.

<Test conditions> Ambient temperature: 100℃ Torsion torque: ±62Kg・m Cycle: 3Hz Mounting angle*: 2 degrees *Angle between the drive shaft and driven shaft in the vertical plane in the drive shaft axial direction The results of the bench durability test are as follows: In the comparative example, the restraint member was broken near the outer circumferential surface of the cylindrical bushings and the rubber disk was damaged after 50,000 cycles, whereas in the present invention, it was not until 280,000 cycles that the restraint member broke near the outer circumferential surface of the cylindrical bushings. A part of the restraint member at the center location was broken, and a crack appeared in the rubber disc near it.

After the test was completed, the test piece was cut and the internal state of the rubber disk was observed. In the comparative example, the restraining member stretched above and below the adjacent cylindrical bushes was
It was found that the cylindrical bushing was disturbed near the outer circumferential surface and buried in the upper and lower parts of each other. On the other hand, in the example of the present invention, there was no disturbance in the restraining member, and the flange at both ends of the cylindrical bushing and the middle The flanges were buried neatly accommodated between each.

In addition, in the present invention, adhesive can be applied not only to the outer circumferential surface of the cylindrical bushing but also to each flange, thereby bonding the outer circumferential surface of the restraining member made of a fiber cord impregnated with unvulcanized rubber glue. The joint surface with the cylindrical bushing is firmly bonded, and the overall shape of the restraint member can be maintained between each flange, so the restraint member is not disturbed and the effects of the present invention can be exhibited more easily. Become.

(Effects of the invention) As detailed above, the invention provides an elastic joint that flexibly connects the drive shaft and the driven shaft, transmits rotational force smoothly, and has excellent durability. can do.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a conventional example, with a half cross section, FIG. 2 is a sectional view taken along the line X-X in FIG. 1, and FIG. FIG. 4 is a cross-sectional view in which the Y-Y section of FIG. 3 is arranged in a straight line. 10...Elastic joint, 20...Rubber disc, 3
0...Cylindrical bushing, 30a...Flange, 40
...Restraint member, 50...Recessed portion.

Claims (1)

[Claim for Utility Model Registration] A roughly rubber disk with a hollowed out center has a plurality of cylindrical bushes with flanges on both ends symmetrically with respect to the center, and a fiber cord formed in a loop shape has a rectangular cross section. In an elastic joint in which a bundled restraining member is alternately strung up and down so as to restrain two adjacent members of the pair of cylindrical bushes, the cylindrical bush further includes an intermediate flange at an intermediate position in the axial direction. The fiber cords constituting the restraining member are impregnated with rubber glue, and the restraining member is arranged vertically separately between both end flanges and an intermediate flange provided on the cylindrical bushing. furthermore, a pair of adjacent 2 of the cylindrical bushes;
On the side where the pieces are not hung by the restraint member, a deep recess is formed along the restraint member from the inner and outer peripheral surfaces of the rubber approximately disk and the tips of the pair of two adjacent cylindrical bushes. An elastic joint characterized in that the rubber is coated and the thickness of the coated rubber in the axial center direction of the cylindrical bushing from the bottom of the recess to the restraint member is approximately uniform.